JPS6118638B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a hydraulic rock drill that strikes a rock drilling rod by vibrating the striking piston through interaction between the spool of the pilot valve and the striking piston.

The present applicant has long discovered that a spool that receives constant pressure and alternating pressure from both sides in a pilot valve interacts with a striking piston that receives constant pressure and alternating pressure from both sides in a cylinder. We have been researching a hydraulic rock drill that vibrates the striking piston to strike the rock drilling rod, and have already filed a patent application for some of the results.
54-9465 (Japanese Utility Model Publication No. 55-110592)), (Japanese Utility Model Application No. 54-78623 (Japanese Utility Model Application No. 178088)) However, this hydraulic rock drill has a spool operating oil passage that communicates the constant pressure side of the percussion piston with the alternating pressure side of the pilot valve, and a piston operating oil passage that communicates the pilot valve with the alternating pressure side of the percussion piston. Since the positions of the oil supply port and the communication port of the oil passage, which open to the cylinder, do not move, the amplitude of the striking piston remains unchanged. Therefore, if the ground is relatively soft, jamming of the rod can be prevented. It has been found that if an attempt is made to reduce the impact force in order to prevent this, the only option is to reduce the supplied oil pressure and oil amount, which causes a problem in that a decrease in downward movement is unavoidable.

The present invention was made mainly to solve the above-mentioned problems that exist in the hydraulic rock drill of the earlier application. A sliding liner is provided, and a fuel supply port is opened near the opening end of the large diameter portion of the sliding liner, and a brake chamber is formed in the step between the small diameter portion and the large diameter portion, and the small diameter of the sliding liner is A high pressure chamber and a low pressure chamber are provided between the sliding liner and the cylinder near the opening end of the section, and when the striking piston overruns during striking, pressure oil is supplied to the high pressure chamber through the communication chamber of the striking piston. The amplitude of the striking piston can be automatically adjusted by sliding the sliding liner, and the rotating shaft of the gear motor is made hollow, and a rock drilling rod is inserted into the hollow part, thereby reducing the size of the hydraulic motor part. This is what I did.

The present invention will be explained according to embodiments shown in the drawings.
1 is a hydraulic rock drill according to the present invention, and includes a pilot valve 2, a cylinder 3, a striking piston 4, a gear motor 5, a thrust receiver 6, a water supply swivel 7, and a shank rod 8. 9 is a spool slidably built into the pilot valve 2, and 10 is a supply/discharge chamber consisting of an annular groove formed in the middle of the spool 9. 11 and 12 are a small-diameter operating rod and a large-diameter operating rod that press both ends of the spool 9, respectively. 13 and 14 are constant pressure chambers and alternating pressure chambers that introduce pressure oil into the end faces of the small-diameter operating rod 11 and the large-diameter operating rod 12, respectively.
An oil supply hole 15, a communication hole 16, and an oil drain hole 17 are provided in the mounting wall of the pilot valve 2 to the cylinder 3, and when the spool 9 moves downward, the oil supply and discharge chamber 1
The communication hole 16 and the oil drain hole 17 communicate with each other through the oil supply and discharge chamber 10, and when the spool 9 moves upward, the oil supply hole 15 and the communication hole 16 communicate with each other through the supply and discharge chamber 10. The cylinder 3 and the striking piston 4 are located on the lower constant pressure side and the upper alternating pressure side of the spool 3.
A fixed liner 18 and a sliding liner 19 each having a small diameter portion and a large diameter portion are provided between the two.
That is, above the striking piston 4 is the sliding liner 1.
The central spool part 20 of the striking piston 4 is connected to the small diameter part 22 of the striking piston 4 in the large diameter part of the fixed liner 18 and the sliding liner 19, and the fixed liner 18 is below the striking piston 4.
are slidably fitted into the small diameter portions 21 of the two. A constant pressure chamber 23 with a small pressure receiving area and an alternating pressure chamber 24 with a large pressure receiving area are formed between the spool portion 20 of the striking piston 4 and the fixed liner 18 and the sliding liner 19. 25 and 2
Reference numeral 6 denotes a communication chamber consisting of an annular groove formed in the spool portion 20 and the lower large diameter portion 21 of the striking piston 4. Brake chambers 27 are located at the stepped portions of the large and small diameter portions of the liners 18 and 19, that is, at the lower end of the constant pressure chamber 23 and at the upper end of the alternating pressure chamber 24.
and 28 are formed. Near the upper opening end of the sliding liner 19, the sliding liner 19 and the cylinder 3 form a high pressure chamber 29 and a low pressure chamber 30, and both chambers 29 and 30 are communicated with each other through a pore 31. A communication port 32 that opens in the middle is provided in the small diameter portion of the fixed liner 18;
A refueling port 33 that opens at the top is provided, and when the striking piston 4 overruns downward, the communication port 32 and the refueling port 33 are connected to each other via the communication chamber 26.
are set up to communicate with each other.

The large diameter portion of the fixed liner 18 is provided with an oil supply port 34 that opens at the bottom of the constant pressure chamber 23, an oil drain port 35 that opens in the middle, and a communication port 36 that opens at the top end. An alternating pressure chamber 24 in the large diameter part
A communication port 37 that opens at the top of the large diameter portion and a refueling port 38 that opens near the lower opening end of the large diameter portion are provided. When the striking piston 4 moves upward, the communication port 36 and the oil filler port 38, and when the striking piston 4 moves downward, the communication chamber 2
5, the communication port 36 and the oil drain port 35 are set to communicate with each other. An oil supply pipe connection port 39 and an oil drain pipe connection port 40 are provided on the upper end surface of the cylinder 3.

Reference numeral 41 denotes a supply oil passage, which includes a hole 13' that communicates the oil supply pipe connection port 39 with the constant pressure chamber 13 of the pilot valve 2;
Oil supply hole 15, oil supply ports 33, 3 of fixed liner 18
4. Connect to the oil supply port 38 of the sliding liner 19.
Reference numeral 42 denotes a drain oil passage, which communicates the drain oil pipe connection port 40 with the drain hole 17 of the pilot valve 2 and the drain port 35 of the fixed liner 18. 43 is a piston operating oil passage, which communicates the communication hole 16 of the pilot valve 2 with the communication port 37 of the sliding liner 19. Reference numeral 44 denotes a spool operating oil passage, which communicates a hole 14' communicating with the alternating pressure chamber 14 of the pilot valve 2 with the communication port 36 of the fixed liner 18. Reference numeral 45 denotes a high pressure path for operating the sliding liner, which is a hole 2 that connects the communication port 32 of the fixed liner 18 to the high pressure chamber 29 at the end of the small diameter portion of the sliding liner 19.
9'.

Numeral 46 is a low pressure passage for operating the sliding liner, and the hole 30' communicating with the low pressure chamber 30 is communicated via a throttle valve 47 with the drain oil pipe connection port 40 or directly with a tank or the like (not shown). 49 is a pair of gears of the gear motor 5 connected to the lower end of the cylinder 3, which rotationally drives a spline-coupled slidable rotary shaft 50 and a spline-coupled slidable shank rod 8. is set to. 51 is a convex portion of the thrust receiver 6, which extends from the collar 52 of the shank rod 8 to the rotating shaft 50.
Thrust is transmitted to the base (not shown) via the flange 53 to prevent thrust from being applied to the gear motor 5 and cylinder 3. 5
Reference numeral 4 denotes a water supply channel provided in the sink rod 8, and is configured to supply water for sliding out from a water supply pipe connection port 55 of the water supply swivel 7 to a bit (not shown) via a water supply channel 54. Note that S is a spring, and 56 is a locking nut for a stopper of the sliding liner 19.

In such a configuration, the hydraulic rock drill 1 is mounted on a leader etc., and the oil supply pipe connection port 39 of the cylinder 3 is
and drain oil pipe connection port 40 are respectively connected to a hydraulic power source, a tank, etc. (not shown). When pressure oil is supplied from the hydraulic source to the supply oil passage 41 through the oil supply pipe connection port 39, the pressure oil passes through the hole 13' and the oil supply port 34.
They are introduced into the constant pressure chamber 13 of the pilot valve 2 and the constant pressure chamber 23 of the cylinder 3, respectively, and in the pilot valve 2, the spool 9 is introduced through the small diameter operating rod 11.
moves downward, and the striking piston 4 in the cylinder 3 starts moving upward. At this time, the alternating pressure chamber 24 in the cylinder 3
communicates with a tank (not shown) through a communication port 37, a piston operating oil passage 43, a communication hole 16, a supply/discharge chamber 10, an oil drain hole 17, an oil discharge passage 42, and an oil drain connection port 40. Next, in the process of upward movement of the striking piston 4, the communication port 36 is opened through the communication chamber 25 formed in the spool portion 20 of the striking piston 4.
When the oil supply port 38 communicates with the oil supply port 38, the pressure oil supplied to the oil supply port 38 is introduced into the alternating pressure chamber 14 of the pilot valve 2 through the communication chamber 25, the communication hole 36, the spool operating oil passage 44, and the hole 14'. Ru. Since the pressure receiving area of the large diameter operating rod 12 is set larger than the pressure receiving area of the small diameter operating rod 11, the large diameter operating rod 11
The spool 9 is moved upward by overcoming the pressing force. When the spool 9 moves upward, the oil supply hole 15 and the communication hole 16 communicate with each other through the supply and discharge chamber 10, and the pressure oil is supplied to the oil supply hole 15, the supply and discharge chamber 10, the communication hole 16, the piston operating oil passage 43, and the communication hole. 37 and is introduced into the alternating pressure chamber 24 of the cylinder 3. Since the pressure receiving area of the striking piston 4 in the alternating pressure chamber 24 is set larger than the pressure receiving area of the striking piston 4 in the constant pressure chamber 23, the striking piston 4 starts moving downward. Next, in the process of downward movement of the striking piston 4, the communication port 36 and the oil drain port 35 communicate with each other via the communication chamber 25, and the pressure oil in the alternating pressure chamber 14 of the pilot valve 2 flows through the hole 14' and the spool operation. Oil passage 44, communication port 36, communication chamber 2
5. The oil is led out to a tank (not shown) through the oil drain port 35, the oil drain path 42, and the oil drain pipe connection port 40, and the pressure in the alternating pressure chamber 14 decreases, so the spool 9 is pressed against the small diameter operating rod 11. Move downward. At this time, the striking piston 4 moves further downward and strikes the upper end surface of the shunt rod 8. Thereafter, by the downward movement of the spool 9, the alternating pressure chamber 24 of the cylinder 3 is communicated with the tank (not shown) as described above, and the pressure inside the alternating pressure chamber 24 decreases, so that the striking piston 4 is moved into the constant pressure chamber. It is pushed by the pressure oil in 23 and moves upward. As the impact piston 4 moves upward and the communication port 36 communicates with the oil supply port 38 via the communication chamber 25 formed in the spool 20 of the impact piston 4 as described above, the spool 9 of the pilot valve 2 is opened. Invert. At this time, when the striking piston 4 moves further upward and the communication port 37 is closed by the spool portion 20, oil is sealed in the brake chamber 28, and the braking action is exerted against the upward movement of the striking piston 4. work. Similarly, the striking piston 4 moves downward and the spool 2
When the oil supply port 34 is closed by the oil supply port 34, oil is sealed in the brake chamber 27, and a braking force is applied to the downward movement of the striking piston 4. Thereafter, the above operation is repeated.

As described above, the spool 9 in the pilot valve 2
The impact piston vibrates due to the interaction between the impact piston 4 in the cylinder 3 and the impact piston 4 in the cylinder 3.
to hit. Shun rod 8 with striking piston 4
When the reaction force applied to the shank rod 8 when striking is small, the shank rod 8 slides downward, and at the same time, the striking piston 4 also slides downward.
When the communication port 32 and the oil supply port 33 communicate with each other via the communication chamber 26 formed in the lower large diameter portion 21 of the striking piston 4, pressurized oil is supplied to the oil supply port 33, the communication chamber 26, the communication port 32, and for operating the sliding liner. It is introduced into the high pressure chamber 29 near the small diameter portion of the sliding liner 19 through the high pressure passage 45 and the hole 29', and the sliding liner 19 is pushed downward by the pressure oil in the high pressure chamber 29. At this time, the oil in the low pressure chamber 30 corresponding to the high pressure chamber 29 flows through the hole 30' and the throttle valve 47.
is discharged from a low pressure passage 46 for operating the sliding liner.

When the sliding liner 19 is slid downward in this way, the positions of the oil filler port 38 and the brake chamber 28 relative to the cylinder 3 change, thereby causing the communication port 36 of the fixed liner 18 and the sliding liner 19 to change. The distance from the oil supply port 38 is shortened, and the pressure oil supplied to the oil supply port 38 is transferred to the communication chamber 25 of the striking piston 4, the communication port 36, the spool operating oil passage 44, and the hole 1.
4' to the alternating pressure chamber 14 of the pilot valve 2 is advanced, and the relative position between the brake chamber 28 and the oil filler port 38 remains unchanged, so that the striking piston is heated with a constant phase difference that is not related to the amplitude. As a result, the timing at which the striking piston 4 starts to move downward is advanced, and as a result, the sliding distance of the striking piston 4 becomes smaller in accordance with the adjusted position of the oil filler port 38, and the amplitude becomes smaller. When the vibrating liner 19 abuts the stationary liner 18, the amplitude is at a minimum.

When the striking piston 4 strikes the shank rod 8, if the reaction force applied to the shank rod 8 is large, it hardly slides downward, and the flange 52 of the shank rod 8, the flange 53 of the rotating shaft 50, and the thrust receiver 6 are When in contact, a communication chamber 26 formed in the lower large diameter portion 21 of the striking piston 4
does not slide to a position where the communication port 32 and the oil supply port 33 are communicated with each other, and therefore no pressure is supplied to the high pressure chamber 29. On the other hand, the reaction force of the pressing force against the striking piston 4 that is generated when pressure oil is supplied to the alternating pressure chamber 24 acts on the sliding liner 19.
An upward pressing force is generated at 9. Since the high pressure chamber 29 and the low pressure chamber 30 are communicated with each other through the pore 31, the oil in the high pressure chamber 29 flows through the pore 31, the low pressure chamber 30, and the hole 3.
0', the sliding liner is discharged through a low pressure passage 46 for operating the sliding liner having a throttle valve 47, and the sliding liner 19 slides upward to connect the communication port 36 of the fixed liner 18 and the oil supply port 38 of the sliding liner 19. The distance increases and the amplitude increases. When the sliding liner 19 abuts the locking nut 56, the amplitude is at its maximum. Also, lock nut 5
By adjusting the position of 6, the maximum amplitude can be adjusted. The sliding speed of the sliding liner 19 can be set as desired by adjusting the diameter of the pore 31 and the throttle of the throttle valve 47 to a predetermined value. For example, when the throttle valve 47 is narrowed down relative to the diameter of the pore 31, less oil is discharged, the sliding speed becomes slower, and the sensitivity of the amplitude adjustment of the striking piston 4 in response to the reaction force of the shank rod 8 becomes more pure.

According to the present invention, by detecting the position of the striking piston using the communication chamber 26 provided in the striking piston and supplying or not supplying pressure oil, oil is applied upwardly or downwardly to the sliding liner 19. Since the structure is such that pressure is applied and the amplitude of the striking piston 4 is automatically changed according to the state of the sink rod 8 when the striking piston strikes, rock drilling work in soft ground is extremely easy. In addition, the rotating shaft 50 of the gear motor 5 is hollow, and the shank rod 8 is rotatably and slidably connected to the hollow part so that the gear motor 5 is directly connected and driven. It can be stored small.

[Brief explanation of the drawing]

The figure is a longitudinal section showing an embodiment of the present invention. 2...Pilot valve, 3...Cylinder, 4...
Impact piston, 9... Spool, 19... Sliding liner, 20... Spool portion, 21... Large diameter portion, 2
5, 26... Communication chamber, 27, 28... Brake chamber, 29... High pressure chamber, 30... Low pressure chamber, 31...
Pore, 33, 34, 38... Oil supply chamber, 44... Spool operating oil path, 47... Throttle valve.

Claims (1)

[Claims] 1 The striking piston is vibrated by the interaction between the spool which receives constant pressure and alternating pressure from both sides in the pilot valve, and the striking piston which receives constant pressure and alternating pressure from both sides in the cylinder. , for striking rock drilling rods, a sliding liner consisting of a small diameter part and a large diameter part is slidably provided between the cylinder on the alternating pressure side and the striking piston, and the size of the sliding liner is A fuel supply port is opened near the open end of the diameter portion, and a brake chamber is formed in the step between the small diameter portion and the large diameter portion, and the sliding liner and the cylinder are connected near the open end of the small diameter portion of the sliding liner. A high pressure chamber and a low pressure chamber are provided between the two, the high pressure chamber and the low pressure chamber are communicated with each other through a small hole, a throttle valve is provided between the low pressure chamber and the tank circuit, and a communication chamber 2 is provided in the spool portion of the striking piston.
6 and a communication chamber formed in the spool portion of the striking piston and the oil supply port provided in the spool hydraulic oil passage near the opening end of the large diameter portion of the sliding liner and communicating with the alternating pressure side of the pilot valve. When the percussion piston overruns, pressure oil is introduced into the high pressure chamber via the communication chamber 26 of the percussion piston to cause the sliding liner to slide, thereby causing the percussion piston to overrun. A hydraulic rock drill which is configured to be able to adjust the amplitude, has a hollow rotary shaft of a gear motor, and has a rock drilling rod rotatably and slidably connected to the hollow part so as to be directly connected and driven by the gear motor.