Description

OIL PRESSURE CIRCUIT SYSTEM TO DRIVE ROCK DRILLING DEVICE IN EXCAVATOR

Technical Field

[1] The present invention relates to an oil pressure circuit system for driving a rock drilling device in an excavator. When a rock drilling device is mounted and used on an excavator, a rock drilling operation can be smoothly performed by the oil pressure circuit system, even though the excavator has a relatively small size in comparison with a hydraulic flow rate according to the specification capacity of the rock drilling device. Background Art

[2] As is generally known, when breaking a rock bed, a rock drilling device is used to drill a predetermined size of hole in the rock bed, and a breaker is then put into the hole to break the rock bed. Among rock drilling devices to be used in such a case, there is provided a rock drilling device which can be connected to an excavator so as to be used. Such a rock drilling device can be implemented in various manners. Recently, a rock drilling device becomes mainstream, which drills a hole in a rock bed while ascending and descending a drilling section. The drilling section is composed of a drilling bit and a core tube, the drilling bit being rotated by a hydraulic pump. The present applicant has already disclosed various rock drilling devices in which torque caused by rotating an ascending/descending motor driven by oil pressure is transmitted to a chain such that a core tube can be ascended and descended in accordance with the rotation of the chain, through Korea Utility Model Registration No. 361015, Korea Utility Model Registration No. 384177, Korea Patent Application No. 2005-107055, Korea Patent No. 555043, Korea Patent Application No. 2006-8655, Korea Patent Application No. 2006-15007 and the like.

[3] Meanwhile, as shown in Fig. 1, a rock drilling device 21 is mounted on an arm of a general excavator 10 and is driven by oil supplied from the excavator 10. In addition to the rock drilling device 21, various kinds of attachments 20 such as a breaker, a crusher, a gram, a cutter, a grapple, a compactor and the like are selectively mounted on the excavator 10 and are driven by oil supplied from the excavator 10.

[4] Therefore, an oil circuit system of the excavator 10 is constructed to move the excavator 10 and to operate all sections of the excavator 10. Further, the oil circuit system of the excavator 10 is constructed to drive the attachment 20 mounted on the excavator 10. As shown in Figs. 2 to 4, the oil circuit system of the excavator 10 includes an oil tank 31; two hydraulic pumps 33 and 34 for pumping oil within the oil

tank 31; an oil pressure control valve block box 40, 40', or 40' provided with an attachment control valve 41, a swing motor control valve 42, a bucket cylinder control valve 43 or 43', an arm cylinder control valve 44 or 44', two driving motor control valves 45 and 45', and a boom cylinder control valve 46; and an automatically- temperature-adjusting oil cooler 35 which automatically adjusts the temperature of oil discharged after circulating through the respective operating sections; and an oil return line filter 36 for filtering foreign matters included in oil.

[5] As shown in Fig. 2, in the excavator 10, tube laying of the oil pressure control valve block box 40 for supplying oil to the respective operating sections from the respective hydraulic pumps 33 and 34 is performed in such a manner that one hydraulic pump 33 supplies oil to the attachment 20 through the attachment control valve 41, supplies oil to the bucket cylinder 12 through the bucket cylinder control valve 43, or supplies oil to one driving motor (not shown) through one driving motor control valve 45, and the other hydraulic pump 34 supplies oil to a swing motor (not shown) through the swing motor control valve 42, supplies oil to an arm cylinder 13 through the arm cylinder control valve 44, or supplies oil to the other driving motor (not shown) through the other driving motor control valve 45'. Further, the tube laying is performed in such a manner that oil pumped by both of the hydraulic pumps 33 and 34 is supplied through the boom cylinder control valve 46 to a boom cylinder 14 to which the largest load is applied among the operating sections of the excavator 10. In order to rapidly and smoothly perform the operation of the arm, tube laying of the oil pressure control valve block box 40' may be performed in such a manner that oil pumped by both of the hydraulic pumps 33 and 34 through the arm cylinder control valve 44' of the oil pressure control valve block box 40' is supplied to the arm cylinder 13, as shown in Fig. 3. In addition, in order to rapidly and smoothly perform the operation of a bucket in a large-sized excavator, tube laying of the oil pressure control valve block box 40" may be performed in such a manner that oil pumped by both of the hydraulic pumps 33 and 34 through the bucket cylinder control valve 43' of the oil pressure control valve block box 40" is supplied to a bucket cylinder 12, as shown in Fig. 4.

[6] That is, in the excavator 10, the oil pumped by both of the hydraulic pumps 33 and

34 is supplied to the boom cylinder 14, the boom cylinder 14 and the arm cylinder 13, or the boom cylinder 14, the arm cylinder 13, and the bucket cylinder 12. Further, oil pumped by any one of the two hydraulic pumps 33 and 34 is supplied to all the other sections including the attachment 20.

[7] As for the hydraulic pumps applied to an excavator, variable-displacement-type plunger pumps are generally used. In addition, other pumps such as fixed-displacement-type plunger pumps, gear-type pumps and the like may be used depending on a maker or the purpose of use. As for automatically-temperature-adjusting oil

coolers, various oil coolers may be adopted depending on a maker.

[8] However, when a rock drilling operation is performed in a narrow place or under a building with a ceiling, the rock drilling device cannot be mounted and used on a large- sized excavator, because a space required for the entrance of the excavator is narrow. Instead, the rock drilling device cannot but be mounted and used on a middle- or small- sized excavator. In this case, since there is a limit in flow rate of oil which can be supplied from the middle- or small-sized excavator, the rock drilling operation cannot be smoothly performed in a narrow place or under a building with a ceiling.

[9] For example, a 0.8m -capacity middle-sized excavator can drive a rock drilling device having only one drilling section, but cannot drive a rock drilling device having more than two drilling sections because of a limitation of flow rate, as in Korea Utility Model Registration No. 384177 filed by the present applicant. Further, a 1.0m - capacity large-sized excavator can drive a rock drilling device having two drilling sections, but cannot drive a rock drilling device having more than three drilling sections because of a limitation of flow rate. Therefore, an available rock drilling device is limited depending on the size of an excavator, that is, a flow rate of oil which can be supplied to the rock drilling device from the excavator. Disclosure of Invention Technical Problem

[10] An advantage of the invention is that it provides an oil pressure circuit system for driving a rock drilling device in an excavator, which is designed to supply oil to the rock drilling device from two hydraulic pumps provided in the excavator. Through the oil pressure circuit system, the rock drilling device can be smoothly driven, even though an excavator having a relatively small size in comparison with the rock drilling device is used.

[11] Another advantage of the invention is that it provides an oil pressure circuit system in which a rock drilling device control valve is designed to be installed in an oil pressure control valve block box in case where an excavator is newly manufactured by each maker. Technical Solution

[12] According to an aspect of the invention, an oil pressure circuit system for driving a rock drilling device in an excavator comprises an oil tank for storing oil; two hydraulic pumps for pumping oil within the oil tank; a rock drilling device connected to the respective hydraulic pumps so as to be mounted on an arm of the excavator; and an oil pressure control valve block box designed to supply oil to a bucket cylinder, an arm cylinder, and a boom cylinder, which operate the arm, from the hydraulic pumps. The oil pressure control valve block box includes a rock drilling device control valve

connected to the two hydraulic pumps, and an oil supply tube is connected between the rock drilling device control valve and the rock drilling device.

Advantageous Effects

[13] According to the invention, when a rock drilling device is mounted on an excavator to perform a rock drilling operation, oil is supplied to the rock drilling device from two hydraulic pumps provided in the excavator. Even though the excavator has a relatively small size in comparison with a hydraulic flow rate according to the specification capacity of the rock drilling device, the rock drilling operation can be smoothly performed. Although the same rock drilling operation is performed, an amount of fuel consumed by the excavator can be reduced to a half such that a profit is created as much. Further, depreciation caused by the abrasion and decrepitude of the excavator and loan (lease) can be saved so that a profit is also created. Accordingly, it is possible to reduce a construction cost and to maximize the efficiency of an excavator. Brief Description of the Drawings

[14] Fig. 1 is a diagram showing a state where a rock drilling operation is performed by a general excavator.

[15] Fig. 2 is a diagram showing the construction of a conventional oil pressure circuit system in an excavator, which is constructed in such a manner that oil is supplied to a boom cylinder from two hydraulic pumps.

[16] Fig. 3 is a diagram showing the construction of a conventional oil pressure circuit system in an excavator, which is constructed in such a manner that oil is supplied to a boom cylinder and an arm cylinder from two hydraulic pumps.

[17] Fig. 4 is a diagram showing the construction of a conventional oil pressure circuit system in an excavator, which is constructed in such a manner that oil is supplied to a boom cylinder, an arm cylinder, and a bucket cylinder from two hydraulic pumps.

[18] Fig. 5 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a first embodiment of the invention.

[19] Fig. 6 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a second embodiment of the invention.

[20] Fig. 7 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a third embodiment of the invention.

[21] Fig. 8 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a fourth embodiment of the invention.

[22] Fig. 9 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a fifth embodiment of the invention.

[23] Fig. 10 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a sixth embodiment of the invention.

[24] Fig. 11 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a seventh embodiment of the invention. [25] Fig. 12 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to an eighth embodiment of the invention. [26] Fig. 13 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a ninth embodiment of the invention. [27] Fig. 14 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a tenth embodiment of the invention. [28] Fig. 15 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to an eleventh embodiment of the invention. [29] Fig. 16 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a twelfth embodiment of the invention. [30] Fig. 17 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a thirteenth embodiment of the invention. [31] Fig. 18 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a fourteenth embodiment of the invention. [32] Fig. 19 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a fifteenth embodiment of the invention. [33] Fig. 20 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a sixteenth embodiment of the invention. [34] Fig. 21 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a seventeenth embodiment of the invention. [35] Fig. 22 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to an eighteenth embodiment of the invention. [36] Fig. 23 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a nineteenth embodiment of the invention. [37] Fig. 24 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 20th embodiment of the invention. [38] Fig. 25 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 21st embodiment of the invention. [39] Fig. 26 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 22nd embodiment of the invention. [40] Fig. 27 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 23rd embodiment of the invention. [41] Fig. 28 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 24th embodiment of the invention. [42] Fig. 29 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 25th embodiment of the invention.

[43] Fig. 30 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 26th embodiment of the invention.

[44] Fig. 31 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 27th embodiment of the invention.

[45] Fig. 32 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 28th embodiment of the invention.

[46]

[47] *Fig. 33 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 29th embodiment of the invention.

[48] Fig. 34 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 30th embodiment of the invention.

[49] Fig. 35 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 31st embodiment of the invention.

[50] Fig. 36 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 32nd embodiment of the invention.

[51] Fig. 37 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a 33rd embodiment of the invention. Best Mode for Carrying Out the Invention

[52] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[53] When work is performed using an excavator having an attachment mounted thereon, the attachment and the excavator should be operated at the same time. On the contrary, when a rock drilling device is used, an excavator should be fixed to a position in which a hole is to be drilled, and on a drilling operation, only the rock drilling device should be operated in a state where operating portions of the excavator are not moved. Therefore, a predetermined amount of oil for driving the operating portions of the excavator can be supplied to the rock drilling device.

[54] The present invention is derived from such a point. Further, excavators to be applied to the invention are not limited to excavators which will be described below. In the drawings, a caterpillar excavator is exemplified. In addition to such a caterpillar excavator, however, a tire excavator can be exemplified. Such a tire excavator has the same oil pressure circuit system as the caterpillar excavator, except for only a driving device, a steering device, an outrigger cylinder, and a dozer cylinder (system). Therefore, the following descriptions should be judged without any discrimination between the caterpillar excavator and the tire excavator.

[55] Further, like reference numerals will be attached to the same components as those of the conventional oil pressure circuit system, and the detailed descriptions may be

omitted.

[56] Fig. 5 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a first embodiment of the invention, Fig. 6 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a second embodiment of the invention, Fig. 7 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a third embodiment of the invention, Fig. 8 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a fourth embodiment of the invention, Fig. 9 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a fifth embodiment of the invention, and Fig. 10 is a diagram showing the construction of an oil pressure circuit system for driving a rock drilling device according to a sixth embodiment of the invention.

[57] The oil pressure circuit system to be applied to the invention basically has almost the same construction as that of a general excavator. However, the oil pressure circuit system according to the invention further includes a rock drilling device control valve

47 connected to two hydraulic pumps 33 and 34 and a oil supply tube 55 connected between the rock drilling device control valve 47 and a rock drilling device 21. In an excavator which is newly manufactured by each maker, such a rock drilling device control valve 47 is constructed together in an oil pressure control valve block box 40, 40', or 40". In other words, the oil pressure control valve block box 40, 40', or 40" and the rock drilling device control valve 47 are designed together so as to be installed in one block.

[58] That is, in the first to third embodiments of the invention, the rock drilling device control valve 47 is constructed integrally with the oil pressure control valve block box 40, 40', or 40". In such a construction, when the rock drilling device 21 is driven, oil is not supplied to all operating sections of the excavator, but can be supplied to only the rock drilling device 21. In the fourth to sixth embodiments, the rock drilling device control valve 47 is added to an excavator 10 which has been already manufactured and used. In this case, the rock drilling device control valve 47 can be constructed separately from the oil control vale block box 40, 40' or 40".

[59] When the oil pressure control valve block box 40, 40', or 40" and the rock drilling device control valve 47 are constructed separately from each other, a rock drilling device control valve block box 48 should be constructed separately from the oil pressure control valve block box 40, 40', or 40" such that the rock drilling device control valve 47 is installed in the rock drilling device control valve block box 48. Although not shown in the drawings, the rock drilling device control valve block box

48 is provided with a safety valve or a relief valve such that oil supplied to the oil

drilling device 21 is set at proper oil pressure, thereby securing stability.

[60] In the drawings, reference numeral 53 represents a stop valve installed in the inflow side of the oil supply tube 55, and reference numeral 54 represents a stop valve installed in an oil return line tube 22 of the rock drilling device 21.

[61] The oil pressure circuit system for driving a rock drilling device, constructed in such a manner, operates as follows.

[62] First, in a state where the rock drilling device 21 is mounted on an arm 11 of the excavator 10, the excavator 10 is moved to a desired position by manipulating the respective hydraulic pumps 33 and 34 and the oil pressure control valve block box 40, 40', or 40", and the rock drilling device 21 is fixed to a place where drilling needs to be performed. Then, a rock drilling operation is started.

[63] In this case, while the rock drilling operation is performed, all the operating sections of the excavator 10 should be stopped. Otherwise, if the excavator 10 moves, the rock drilling operation cannot only performed, but also the rock drilling device 21 can be broken down or damaged.

[64] Therefore, when the rock drilling operation is performed, all the other operating sections of the excavator 10 cannot but be fixed, and a flow rate of oil for driving the excavator 10 remains. The oil can be supplied to the oil driving device 21.

[65] In the present invention, when an excavator is newly manufactured, the rock drilling device control valve 47 dedicated to the rock drilling device is integrally designed and installed in the oil pressure control valve block box 40, 40', or 40" such that the rock drilling device control valve 47 is included in one block. When an existing manufactured excavator is used, the rock drilling device control valve block box 48 is manufactured separately from the oil pressure control valve block box 40, 40', or 40" such that the rock drilling device control valve 47 is included in the rock drilling device control valve block box 48. Further, the oil supply tube 55 is connected between the rock drilling device control valve 47 and the rock drilling device. When the excavator 10 is driven, the stop valve 53 of the oil supply tube 55 and the stop valve 54 of the oil return line tube 22 are all closed so that oil is not supplied to the oil driving device 21. When the rock drilling operation is performed, the stop valve 53 installed in the inflow side of the oil supply tube 55 and the stop valve 54 of the oil return line tube 22 are all opened. In this state, the rock drilling device control valve 47 is manipulated so as to supply oil to the rock drilling device 21 through the two hydraulic pumps 33 and 34 via the rock drilling device control valve 47. Therefore, oil can be supplied at a flow rate two times higher than when oil is supplied from one hydraulic pump 33 or 34, which means that the rock drilling operation of the rock drilling device 21 can be smoothly performed even though the rock drilling device 21 is mounted and used on an excavator 10 having a relatively small size in comparison

with a hydraulic flow rate according to the specification capacity of the rock drilling device 21.

[66] That is, a flow rate of oil, which is supplied to an attachment 20 from a 0.6m - capacity small-sized excavator 10, is lower than that required for driving the rock drilling device 21. Conventionally, the rock drilling device 21 could not be mounted and used on such a small-size excavator 10. In the present invention, however, since oil can be supplied to the rock drilling device 21 from the two hydraulic pumps 33 and 34, the rock drilling device 21 can be smoothly driven by the small-sized excavator 10. Therefore, the rock drilling operation can be smoothly performed even in a narrow place or under a building with a ceiling.

[67] Further, a 0.8m -capacity middle-sized excavator 10 can drive a rock drilling device

21 having only one drilling section, as disclosed in Korea Utility Model Registration No. 384177. However, a supply flow rate thereof is not sufficient enough to drive a rock drilling device 21 having more than two drilling sections. According to the invention, although the rock drilling device 21 having two drilling sections is mounted and used on the middle-sized excavator 10, a sufficient flow rate of oil for driving the rock drilling device 21 can be maintained so that excellent operational efficiency is achieved.

[68] In addition, a 1.0m -capacity large-sized excavator 10 can drive a rock drilling device 21 having two drilling sections, but a supply flow rate thereof is not sufficient enough to drive a rock drilling device 21 having three drilling sections. According to the invention, although the rock drilling device 21 having three drilling sections is mounted and used on the middle-sized excavator 10, a sufficient flow rate of oil for driving the rock drilling device 21 can be maintained so that excellent operational efficiency is achieved.

[69] In this case, when the rock drilling device control valve 47 is integrally installed in the oil pressure control valve block box 40, 40', or 40" as in the first to third embodiments, and when the rock drilling device control valve block box 48 is manufactured separately from the oil pressure control valve block box 40, 40', or 40" such that the rock drilling device control valve 47 is included in the rock drilling device control valve block box 48 as in the fourth to sixth embodiments, the rock drilling device control valve 47 has the same function for both cases. However, when the rock drilling device control valve 47 is separated from the oil pressure control valve block box 40, 40', or 40", the rock drilling device control valve 47 is inconvenient to install and occupies a large space. Therefore, when an excavator is newly manufactured, the rock drilling device control valve 47 is preferably integrated into the oil pressure control valve block box 40, 40', or 40". When an existing manufactured excavator is used, the rock drilling device control valve 47 is preferably added thereto.

[70] The oil supplied to the rock drilling device 21 drives the rock drilling device 21 and is then discharged through the oil return line tube 22. The discharged oil is collected into an oil tank 31 through an automatically-temperature-adjusting oil cooler 35 and an oil return line filter 36. After the rock drilling operation is completed, the respective stop valves 53 and 54 of the oil supply tube 55 and the oil return line tube 22 are closed.

[71] Typically, the largest load is applied to a boom cylinder 14 among the operating sections of the excavator 10, and oil pumped from both of the hydraulic pumps 33 and 34 is supplied to the boom cylinder 14 through a boom cylinder control valve 46. Therefore, when an existing manufactured excavator is used, oil can be supplied to the rock drilling device 21 by utilizing the boom cylinder control valve 46 without the rock drilling device control valve 47 which is constructed in the first to sixth embodiments.

[72] Figs. 11 to 19 are diagrams showing the constructions of oil pressure circuit systems for driving a rock drilling device according to seventh to fifteenth embodiments of the invention, in which oil can be supplied to the rock drilling device 21 by utilizing the boom cylinder control valve 46 of the coil pressure control valve block box 40, 40', or 40", as described above. The seventh, tenth, and thirteenth embodiments are applied to an excavator 10 which is constructed to supply oil to only the boom cylinder 14 from the two hydraulic pumps 33 and 34, the eighth, eleventh, and fourteenth embodiments are applied to an excavator 10 which is constructed to supply oil to the boom cylinder 14 and an arm cylinder 13 from the two hydraulic pumps 33 and 34, and the ninth, twelfth, and fifteenth embodiments are applied to an excavator 10 which is constructed to supply oil to the boom cylinder 14, the arm cylinder 13, and a bucket cylinder 12 from the two hydraulic pumps 33 and 34.

[73] As shown in the drawings, the oil pressure circuit systems according to the seventh to fifteenth embodiments of the invention also have almost the same construction as that of a general excavator. In the oil pressure circuit systems according to the seventh to fifteenth embodiments, however, an oil supply direction switching valve 60 is installed on an oil supply tube 50 drawn from the boom cylinder control valve 46 of the oil pressure control valve block box 40, 40', or 40". Further, an oil supply tube 51 at the boom cylinder and an oil supply tube 52 at the rock drilling device respectively diverge from the oil supply direction switching valve 60 such that the oil supply tube

51 at the boom cylinder is connected to the boom cylinder 14 and the oil supply tube

52 at the rock drilling device is connected to the rock drilling device 21. In such a structure, oil is selectively supplied to the boom cylinder 14 and the rock drilling device 21 in accordance with the switching of the oil supply direction switching valve 60.

[74] In this case, the oil supply direction switching valve 60 can be implemented in

various manners. In the seventh to ninth embodiments, a three-port solenoid direction switching valve may be applied as the oil supply direction switching valve 60. In the tenth to twelfth embodiments, a three-port lever direction switching valve 62 can be applied as the oil supply direction switching valve 60. In the thirteenth to fifteenth embodiments, a three-port stop direction switching valve 63 can be applied as the oil supply direction switching valve 60.

[75] Further, in the seventh to fifteenth embodiments, a pilot-operated check valve 64 is additionally installed between the boom cylinder and the oil supply direction switching valve of the oil supply tube 51 at the boom cylinder such that sealing is perfectly performed. In such a structure, locking is reliably achieved with respect to a large load, and oil supplied toward the boom cylinder 14 can be prevented from flowing backward.

[76] In the drawings, reference numeral 53 represents a stop valve installed in the inflow side of the oil supply tube 52, and reference numeral 54 represents a stop valve installed in the oil return line tube 22 of the rock drilling device 21.

[77] In such a construction, when the excavator 10 is driven, the stop valve 43 in the inflow side of the oil supply tube 52 at the rock drilling device and the stop valve 54 of the oil return line tube 22 are all closed, and the oil supply direction switching valve 60 is manipulated so as to communicate with the oil supply tube 51 at the boom cylinder. Then, all the operating sections of the excavator 10 can be smoothly operated. When a rock drilling operation is performed, the oil supply direction switching valve 60 is manipulated so as to communicate with the oil supply tube 52 at the rock drilling device in a state where the stop valve 53 in the inflow side of the oil supply tube 52 at the rock drilling device and the stop valve 54 of the oil return line 22 are all opened. Then, oil can be supplied to the rocking drilling device 21 from the two hydraulic pumps 33 and 34, which means that oil can be supplied at a flow rate two times higher than when oil is supplied from one hydraulic pump 33 or 34.

[78] Therefore, the rock drilling operation of the rock drilling device 21 can be smoothly performed even though the rock drilling device 21 is mounted on an excavator 10 having a relatively small size in comparison with a hydraulic flow rate according to the specification capacity of the rock drilling device 21.

[79] As for the oil supply direction switching valve 60, any valve can be applied, which can perform switching such that oil can be selectively supplied to the oil supply tube 51 at the boom cylinder or to the oil supply tube 52 at the rock drilling device in accordance with the driving of the boom cylinder 14 of the excavator 10 or the driving of the rock drilling device 21. For example, when the oil supply direction switching valve 60 is composed of a three-port solenoid direction switching valve 61 as in the seventh to ninth embodiments of the invention, the direction of the three-port solenoid

direction switching valve 61 is automatically switched by an electrical signal such that a supply direction of oil can be selected. When the oil supply direction switching valve 60 is composed of a three-port lever direction switching valve 62 as in the tenth to twelfth embodiments, the direction of the three-port lever direction switching valve 62 is switched in accordance with the direction of a lever manipulated by a user such that a supply direction of oil can be selected. When the oil supply direction switching valve 60 is composed of a three-port stop direction switching valve 63 as in the thirteenth to fifteenth embodiments, the three-port stop direction switching valve 63 is manually manipulated to select a supply direction of oil, similar to the tenth to twelfth embodiments.

[80] The oil supplied to the rock drilling device 21 drives the rock drilling device 21 and is then discharged through the oil return line tube 22. The discharged oil is collected into the oil tank 31 through the automatic temperature-adjusted oil cooler 35 and the oil return line filter 36. After the rock drilling operation is completed, the respective stop valves 53 and 54 of the oil supply tube 55 at the rock drilling device and the oil return line tube 22 are closed, and the direction of the oil supply direction switching valve 60 is switched toward the boom cylinder 14. Then, the excavator 10 can be operated or moved.

[81] Meanwhile, a certain excavator 10 is designed in such a manner that oil pumped from both of the hydraulic pumps 33 and 34 is supplied to the arm cylinder 13 through the arm cylinder control valve 44'. Then, an arm of the excavator 10 can be rapidly and smoothly operated. Therefore, when an existing manufactured excavator is used, oil can be supplied toward the oil drilling device 21 by utilizing the arm cylinder control valve 44' of the oil pressure control valve block box 40' or 40", different from the first to fifteenth embodiments.

[82] Figs. 20 to 31 are diagrams showing the constructions of oil pressure circuit systems for driving a rock drilling device according to sixteenth to 27th embodiments of the invention, which are designed in such a manner that oil can be supplied to the rock drilling device 21 by utilizing the arm cylinder control valve 44' of the oil pressure control valve block box 40' or 40", as described above. As shown in the drawings, the oil pressure circuit systems according to the sixteenth to 27th embodiments of the invention also have the same construction as that of a general excavator. In the oil pressure circuit systems according to the sixteenth to 27th embodiments, however, an oil supply direction switching valve 70 is installed in any one of first and second oil supply tubes 56 and 57 which supplies oil to the arm cylinder 13 from the arm cylinder control valve 44' of the oil pressure control valve block box 40 or 40" or discharges oil for extension and contraction of the arm cylinder 13. Further, an oil supply tube 58 at the rock drilling device and an oil supply tube 59 at the arm

cylinder respectively diverge from the oil supply direction switching valve 70 such that the oil supply tube 58 at the rock drilling device is connected to the rock drilling device 21 and the oil supply tube 59 at the arm cylinder is connected to the front or rear side of the arm cylinder 13. Simultaneously, the other oil supply tube 56 or 57 where the oil supply direction switching valve 70 is not installed is directly connected to the opposite side to the connection portion of the arm cylinder with the oil supply tube at the arm cylinder. In such a structure, oil is selectively supplied to the arm cylinder 13 and the rock drilling device 21 in accordance with the switching of the oil supply direction switching valve 70.

[83] In the sixteenth, eighteenth, 20th, 22nd, 24th, and 26th embodiments of the invention, the oil supply direction switching valve 70 is installed in the first oil supply tube 56 which operates to extend the arm cylinder 13. In the seventeenth, nineteenth, 21st, 23rd, 25th, and 27th embodiments, the oil supply direction switching valve 70 is installed in the second oil supply tube 57 which operates to contract the arm cylinder 13.

[84] In this case, the oil supply direction switching valve 70 can be implemented in various manners. In the sixteenth to nineteenth embodiments, a three-port solenoid direction switching valve 71 can be applied as the oil supply direction switching valve 70. In the 20th to 23rd embodiments, a three-port lever direction switching valve 72 can be applied as the oil supply direction switching valve 70. In the 24th to 27th embodiments, a three-port stop direction switching valve 73 can be applied as the oil supply direction switching valve 70.

[85] Further, in the sixteenth to 27th embodiments, stop valves 74 and 75 are respectively installed in the middle portion of one oil supply tube 56 or 57, where the oil supply direction switching valve 70 is not installed, and between the arm cylinder and the oil supply direction switching valve of the oil supply tube 59 at the arm cylinder. When the rock drilling device 21 is operated, the stop valves 74 and 75 are all closed to prevent oil from flowing into and leaking from the arm cylinder 13. Then, oil is secondarily blocked after the oil supply direction switching valve 70, so that sealing is perfectly performed. Therefore, locking is reliably achieved, and the rock drilling operation can be safely performed.

[86] In the drawings, reference numeral 53 represents a stop valve installed in the inflow side of the oil supply tube 58 at the rock drilling device, and reference numeral 54 represents a stop valve installed in the oil return line tube 22 of the rock drilling device 21.

[87] In such a construction, when an excavator 10 is driven, the stop valve 53 in the inflow side of the oil supply tube 58 at the rock drilling device and the stop valve 54 of the oil return line tube 22 are all closed, and the oil supply direction switching valve 70

is manipulated so as to communicate with the oil supply tube 59 at the arm cylinder. Then, all the operating sections of the excavator 10 can be smoothly operated. When a rock drilling operation is performed, the oil supply direction switching valve 70 is manipulated so as to communicate with the oil supply tube 58 at the rock drilling device in a state where the stop valve 53 in the inflow side of the oil supply tube 58 at the rock drilling device and the stop valve 54 of the oil return line tube 22 are all opened. Then, oil can be supplied to the rock drilling device 21 from both of the hydraulic pumps 33 and 34, which means that oil can be supplied at a flow rate two times higher than when oil is supplied from one hydraulic pump 33 or 34.

[88] Therefore, the rock drilling operation of the rock drilling device 21 can be smoothly performed, even though the rock drilling device 21 is mounted and used on an excavator 10 having a relatively small size in comparison with a hydraulic flow rate according to the specification capacity of the rock drilling device 21.

[89] In this case, as for the oil supply direction switching valve 70, any valve can be applied, which can perform switching such that oil is selectively supplied to the oil supply tube 59 at arm cylinder or the oil supply tube 58 at the rock drilling device in accordance with the driving of the arm cylinder 13 of the excavator 10 or the driving of the rock drilling device 21. For example, in the sixteenth to nineteenth embodiments of the invention, when the oil supply direction switching valve 70 is composed of a three- port solenoid direction switching valve 71, the direction of the three-port solenoid direction switching valve 71 is automatically switched by an electrical signal such that a supply direction of oil can be selected. In the 20th to 23rd embodiments, when the oil supply direction switching valve 70 is composed of a three-port lever direction switching valve 72, the direction of the three-port lever direction switching valve 72 is switched in accordance with the direction of a lever manipulated by a user such that a supply direction of oil can be selected. In the 24th to 27th embodiments, when the oil supply direction switching valve 70 is composed of a three-port stop direction switching valve 73, the three-port stop direction switching valve 73 is manually manipulated so that a supply direction of oil can be selected, similar to the 20th to 23rd embodiments.

[90] The oil supplied to the rock drilling device 21 drives the rock drilling device 21 and is then discharged through the oil return line tube 22. The discharged oil is collected into the oil tank 31 through the automatically-temperature-adjusting oil cooler 35 and the oil return line filter 36. After the rock drilling operation is completed, the respective stop valves 53 and 54 of the oil supply tube 58 at the rock drilling device and the oil return line tube 22 are closed, and the direction of the oil supply direction switching valve 70 is switched toward the arm cylinder 13. Then, the excavator 10 can be operated or moved.

[91] Meanwhile, a certain excavator 10 having a large size is designed in such a manner that oil pumped from both of the hydraulic pumps 33 and 34 is supplied to the bucket cylinder 12 through a bucket cylinder control valve 43'. Then, a bucket thereof can be operated rapidly and smoothly. Therefore, when an existing manufactured excavator is used, oil can be supplied toward the rock drilling device 21 by utilizing the bucket cylinder control valve 43' of the oil pressure control valve block box 40", different from the first to 27th embodiments.

[92] Figs. 32 to 37 are diagrams showing the constructions of oil pressure circuit systems for driving a rock drilling device according to 28th to 33rd embodiments of the invention, which are designed in such a manner that oil can be supplied to the rock drilling device 21 by utilizing the bucket cylinder control valve 43' of the oil pressure control valve block box 40", as described above. As shown in the drawings, the oil pressure circuit systems according to the 28th to 33rd embodiments of the invention basically have the same construction as that of a general excavator. In the oil pressure circuit systems according to the 28th to 33rd embodiments, however, an oil supply direction switching valve 80 is installed in any one of first and second oil supply tubes 56' and 57' for supplying oil to the bucket cylinder 12 from the bucket cylinder control valve 43' of the oil pressure control valve block box 40" or discharging oil for extension and contraction of the bucket cylinder 12. Further, an oil supply tube 58' at the rock drilling device and an oil supply tube 59' at the bucket cylinder respectively diverge from the oil supply direction switching valve 80 such that the oil supply tube 58' at the rock drilling device is connected to the rock drilling device 21 and the oil supply tube 59' at the bucket cylinder are connected to the front or rear side of the bucket cylinder 12. Simultaneously, the other oil supply tube 56' or 57', where the oil supply direction switching valve 80 is not installed, is directly to the opposite side to the connection portion of the bucket cylinder with the oil supply tube at the bucket cylinder such that oil is selectively supplied to the bucket cylinder 12 and the rock drilling device 21 in accordance with the switching of the oil supply direction switching valve 80.

[93] In the 28th, 30th, and 32nd embodiments, the oil supply direction switching valve

80 is installed in the first oil supply tube 56' which operates to extend the bucket cylinder 12. In the 29th, 31st, and 33rd embodiments, the oil supply direction switching valve 80 is installed in the second oil supply tube 57' which operates to contract the bucket cylinder 12.

[94] In this case, the oil supply direction switching valve 80 can be implemented in various manners. In the 28th and 29th embodiments, a three-port solenoid direction switching valve 81 can be applied as the oil supply direction switching valve 80. In the 30th and 31st embodiments, a three-port lever direction switching valve 82 can be

applied as the oil supply direction switching valve 80. In the 32nd and 33rd embodiments, a three-port stop direction switching valve 83 can be applied as the oil supply direction switching valve 80.

[95] In the 28th to 33rd embodiments, stop valves 74' and 75' are respectively installed in the middle portion of one oil supply tube 56' or 57', where the oil supply direction switching valve 80 is not installed, and between the bucket cylinder and the oil supply direction switching valve of the oil supply tube 59' at the bucket cylinder. When the rock drilling device 21 is operated, the stop valves 74' and 75' are all closed to prevent oil from flowing into or leaking from the bucket cylinder 12. Then, oil is secondarily blocked after the oil supply direction switching valve 70, so that sealing is perfectly performed. Therefore, locking is reliably achieved, and the rock drilling operation can be safely performed.

[96] In the drawings, reference numeral 53 represents a stop valve installed in the inflow side of the oil supply tube 58' at the rock drilling device, and reference numeral 54 represents a stop valve installed in the oil return line tube 22 of the rock drilling device 21.

[97] In such a construction, when the excavator 10 is driven, the stop valve 53 in the inflow side of the oil supply tube 58' at the rock drilling device and the stop valve 54 of the oil return line tube 22 are all closed, and the oil supply direction switching valve 80 is manipulated so as to communicate with the oil supply tube 59' at the bucket cylinder. Then, all the operating sections of the excavator 10 can be smoothly operated. When the rock drilling operation is performed, the oil supply direction switching valve 80 is manipulated so as to communicate with the oil supply tube 58' at the rock drilling device in a state where the stop valve 53 in the inflow side of the oil supply tube 58' at the rock drilling device and the stop valve 54 of the oil return line tube 22 are all opened. Then, oil can be supplied to the rock drilling device 21 from both of the hydraulic pumps 33 and 34, which means that oil can be supplied at a flow rate two times higher than when oil is supplied from one hydraulic pump 33 or 34.

[98] Therefore, the rock drilling operation of the rock drilling device 21 can be smoothly performed even though the rock drilling device 21 is mounted on an excavator 10 having a relatively small size in comparison with a hydraulic flow rate according to the specification capacity of the rock drilling device 21.

[99] In this case, as for the oil supply direction switching valve 80, any valve can be applied, which can perform switching such that oil is selectively supplied to the oil supply tube 59' at the bucket cylinder or the oil supply tube 58' at the rock drilling device in accordance with the driving of the bucket cylinder 13 of the excavator 10 or the driving of the rock drilling device 21. For example, in the 28th and 29th embodiments of the invention, when the oil supply direction switching valve 80 is

composed of a three-port solenoid direction switching valve 81, the direction of the three-port solenoid direction switching valve 81 is automatically switched by an electrical signal such that a supply direction of oil can be selected. In the 30th to 31st embodiments, when the oil supply direction switching valve 80 is composed of a three- port lever direction switching valve 82, the direction of the three -port lever direction switching valve 82 is switched in accordance with the direction of a lever manipulated by a user such that a supply direction of oil can be selected. In the 32nd and 33rd embodiments, when the oil supply direction switching valve 80 is composed of a three- port stop direction switching valve 83, the three -port stop direction switching valve 83 is manually manipulated so that a supply direction of oil can be selected, similar to the 30th to 31st embodiments.

[100] The oil supplied to the rock drilling device 21 drives the rock drilling device 21 and is then discharged through the oil return line tube 22. The discharged oil is collected into the oil tank 31 through the automatically temperature-adjusting oil cooler 35 and the oil return line filter 36. After the rock drilling operation is completed, the respective stop valves 53 and 54 of the oil supply tube 58' at the rock drilling device and the oil return line tube 22 are closed, and the direction of the oil supply direction switching valve 80 is switched toward the bucket cylinder 12. Then, the excavator 10 can be operated or moved.

[101] In the present invention, the caterpillar excavator has been exemplified. However, a tire excavator has the same oil pressure circuit system as the caterpillar excavator, except for only a driving device, a steering device, an outrigger cylinder, and a dozer cylinder (system). Therefore, the oil pressure circuit systems described in the invention can be all applied to the caterpillar excavator and the tire excavator.

[102]