JP4017054B2 - Jam prevention device for drilling machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a jamming prevention device for a drilling machine that prevents jamming by reducing a thrust of a feed mechanism when a rotational resistance increases in the drilling machine in a drilling machine such as a crawler drill or a down-the-hole drill.
[0002]
[Prior art]
Drilling machines such as crawler drills and down-the-hole drills used to drill rocks in quarries and mines have a striking mechanism, a rotating mechanism, and a feeding mechanism on a guide shell supported by a boom. I have.
[0003]
For example, in a crawler drill, as shown in FIG. 3, a drifter 4 having a striking mechanism 2 and a rotation mechanism 3 is mounted on a guide shell 1 so as to be movable back and forth by a carriage 5. The guide shell 1 is provided with a feed mechanism 8 including a feed chain 6 connected to the feed chain 6 and a feed motor 7 for driving the feed chain 6.
[0004]
A rod 9 is inserted into the drifter 4, and a bit 10 is attached to the tip of the rod 9, and the tip of the rod 9 is supported by a centralizer 11 provided at the tip of the guide shell 1.
[0005]
At the time of drilling, the feed motor 7 is rotated, and the carriage 5 is moved on the guide shell 1 via the feed chain 6 to feed the drifter 4. The drifter 4 transmits a hit and rotation from the hitting mechanism 2 and the rotating mechanism 3 to the bit 10 through the rod 9 and drills in the rock.
[0006]
In the down-the-hole drill, as shown in FIG. 4, there is a difference that the rotating mechanism 3 is mounted on the carriage 5 and the striking mechanism 2 is provided at the tip of the rod 9. There is no change in the basic configuration including the rotation mechanism 3 and the feed mechanism 8.
[0007]
When drilling into the rock mass with such a drilling machine, where the rock mass is stable, the rotational resistance of the rod 9 and the bit 10 is small and the torque is stable, so there is no problem in the drilling operation.
[0008]
However, for example, when drilling unstable rocks with fractured zones, soft formations, cracks, cavities, etc., hole bending occurs, or it becomes difficult to discharge dust and the rotational resistance increases. The so-called jamming often occurs when the torque becomes unstable and the rod 9 and the bit 10 are taken by rocks and cannot be recovered.
[0009]
Therefore, the punching machine is provided with a jamming prevention device as shown in FIGS. 5 and 6 in order to reduce jamming by reducing the thrust of the feed mechanism 8 when the rotational resistance increases in the drilling hole. .
[0010]
In the drilling machine, a forward rotation line 15 and a reverse rotation line 16 are connected from a rotation control valve 14 to a drill rotation motor 13 of the rotation mechanism 3, and a feed control valve is connected to a feed motor 7 of the feed mechanism 8. From 17, a forward pipeline 18 and a backward pipeline 19 are connected. Further, a relief pipe line 22 having a vented main relief valve 21 is provided between the forward pipe line 18 and the tank 20, and a pilot relief valve 24 is provided in the vent pipe line 23 of the main relief valve 21. Is provided. The main relief valve 21 controls the pressure of the forward passage 18 of the feed motor 7 in order to adjust the thrust of the feed mechanism 8, and the operating pressure is remotely controlled by operating the handle 25 of the pilot relief valve 24. It is like that.
[0011]
The jamming prevention device of FIG. 5 is provided with a normally open pilot operation switching valve 26 in the middle of the forward pipeline 18 and the backward pipeline 19 of the feed motor 7 in the above circuit. The pilot line 28 is connected from the forward rotation line 15 of the drill rotation motor 13 via the sequence valve 27, and the rotational torque of the drill rotation motor 13 increases as the rotational resistance increases, and the pressure of the normal rotation line 15 increases. When the pressure set in advance in the sequence valve 27 is reached, the pilot operation switching valve 26 is switched to the closed side, and the supply of pressure oil to the feed motor 7 is stopped.
[0012]
From the pilot line 28, a return line 30 provided with a throttle 29 is connected to the tank 20, and when the pressure in the normal rotation line 15 decreases, the pilot operation switching valve 26 is returned to the open side, Supply of pressure oil to the feed motor 7 is resumed.
[0013]
The jamming prevention device of FIG. 6 is provided with a normally-open communication switching valve 32 by connecting a communication line 31 between the reverse line 19 of the feed motor 7 and the forward rotation line 15 of the drill rotation motor 13. A normally closed shut-off switching valve 33 is provided on the feed control valve 17 side of the retreat line 19, and the operating pressure on the forward rotation side of the drill rotation motor 13 is applied to the back pressure of the feed motor 7 at the time of forward movement. The thrust of the feed mechanism 8 is lowered by lowering the feed pressure of the feed motor 7 by increasing the pressure of the passage 15.
[0014]
When ancillary work other than drilling is performed, for example, when the carriage 5 is retracted, the communication switching valve 32 and the shut-off switching valve 33 are switched to shut off the communication pipe 31 and send the reverse pipe 19. The control valve 17 is communicated.
[0015]
[Problems to be solved by the invention]
However, in the jamming prevention device of FIG. 5, when the pressure in the forward rotation line 15 of the drill rotation motor 13 increases due to an increase in rotational resistance, the pilot operation switching valve 26 is switched to forcibly supply the pressure oil to the feed motor 7. In order to stop the supply, residual pressure remains in the piping hose, the timing when the thrust drops is actually slightly delayed, the sensitivity to jamming is slightly dull, and shock and noise due to sudden pressure fluctuations are applied to the hydraulic equipment. It is easy to generate and there is a risk of shortening the life of the hydraulic equipment. Moreover, since it is necessary to provide the pilot operation switching valve 26 directly in the forward pipeline 18 and the backward pipeline 19 of the feed motor 7, the apparatus tends to be large.
[0016]
On the other hand, in the jamming prevention device of FIG. 6, a communication switching valve 32, a shut-off switching valve 33, and a circuit for switching control thereof (electrical or electrical) are provided so as to perform ancillary operations other than drilling, for example, the carriage 5 is retracted. Cost), which increases the cost. Further, since the return of the feed motor 7 flows into the drill rotation motor 13 during drilling, the rotation of the drill rotation motor 13 may fluctuate and the drilling operation may become unstable. In addition, since it is necessary to provide the switching valve 32 for communication and the switching valve 33 for shutoff in the backward pipeline 19 of the feed motor 7, the apparatus tends to be large.
[0017]
The present invention solves the above-mentioned problem in the jamming prevention device of a drilling machine, and there is no residual pressure in the piping hose by forcibly stopping the supply of pressure oil to the feed motor, and the response to jamming. In addition, it is difficult to cause sudden pressure fluctuations in hydraulic equipment, and it is possible to suppress impacts and vibrations and improve durability. In addition, the number of parts is simple, the circuit is simple, trouble is reduced, and costs can be reduced. An object of the present invention is to provide an anti-jamming device for a punching machine.
[0018]
[Means for Solving the Problems]
The punching jam prevention device of the present invention comprises a rotation mechanism and a feed mechanism, and a normal rotation line and a reverse line are connected from a rotation control valve to a drill rotation motor of the rotation mechanism. In a drilling machine in which the advance line and the reverse line are connected from the feed control valve, a pressure control valve with a vent is provided in the advance line of the feed motor, and the pilot operation is normally closed in the vent line of the pressure control valve A switching valve is provided, and the pilot pipe line is connected to the pilot port of the pilot operation switching valve from the normal rotation pipe line of the drill rotation motor via the sequence valve.
[0019]
When performing the drilling operation, the operator operates the rotation control valve and the feed control valve to supply pressure oil to the drill rotation motor of the rotation mechanism and the feed motor of the feed mechanism, and starts drilling. When the rotational resistance of the drill rotation motor increases due to the increase in rotational resistance and the pressure in the forward rotation line rises and reaches the pressure set in the sequence valve in advance, the pilot operation switching valve is switched to the open side, and the forward line As the pressure drops, the thrust drops and jamming is avoided.
[0020]
When the rotational resistance decreases and the pressure in the normal rotation line 15 decreases, the pilot operation switching valve returns to the closed side and increases the pressure in the forward line.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a hydraulic circuit diagram of a jamming prevention device for a drilling machine showing an embodiment of the present invention.
[0022]
The punching machine is the same as the conventional one shown in FIG. 3, and includes a striking mechanism 2, a rotating mechanism 3, and a feeding mechanism 8 on the guide shell 1. In this drilling machine, a forward rotation line 15 and a reverse rotation line 16 are connected from a rotation control valve 14 to a drill rotation motor 13 of the rotation mechanism 3, and feed control is performed to the feed motor 7 of the feed mechanism 8. A forward line 18 and a backward line 19 are connected from the valve 17. Further, a relief pipe line 22 having a vented main relief valve 21 is provided between the forward pipe line 18 and the tank 20, and a pilot relief valve 24 is provided in the vent pipe line 23 of the main relief valve 21. Is provided. The main relief valve 21 controls the pressure of the forward passage 18 of the feed motor 7 in order to adjust the thrust of the feed mechanism 8, and the operating pressure is remotely controlled by operating the handle 25 of the pilot relief valve 24. It is like that.
[0023]
The bypass line 40 is branched from the vent line 23 of the main relief valve 21 and connected to the tank 20, and a normally closed pilot operation switching valve 41 is provided in the bypass line 40. A pilot line 43 is connected to the pilot port of the pilot operation switching valve 41 from the normal rotation line 15 of the drill rotation motor 13 via the sequence valve 42. From this pilot line 43, a return line 45 provided with a throttle 44 is connected to the tank 20.
[0024]
When performing the drilling operation, the operator operates the rotation control valve 14 and the feed control valve 17 to supply pressure oil to the drill rotation motor 13 of the rotation mechanism 3 and the feed motor 7 of the feed mechanism 8, Start drilling. When the rotational resistance increases, the rotational torque of the drill rotation motor 13 increases and the pressure in the normal rotation line 15 increases to reach the pressure set in the sequence valve 42 in advance, so that the sequence valve 42 opens and the pilot operation switching valve. 41 is switched to the open side, the pressure in the forward pipeline 18 decreases, the thrust decreases, and jamming is avoided.
[0025]
When the rotation resistance decreases and the pressure in the normal rotation line 15 decreases, the sequence valve 42 is closed, and the oil in the pilot line 43 flows out from the return line 45 to the tank 20, so the pilot operation switching valve 41 is closed. Returning to the side, the pressure in the forward line 18 is increased. Therefore, the pressure in the forward line 18 is again remotely controlled by operating the handle 25 of the pilot relief valve 24.
[0026]
FIG. 2 is a hydraulic circuit diagram of a jamming prevention device for a drilling machine showing another embodiment of the present invention.
[0027]
This jamming prevention device is provided with a pressure reducing valve 46 in the middle of the forward pipeline 18 in place of the main relief valve 21 of the jamming prevention device of FIG. Others are the same as those in FIG. 1, a pilot relief valve 24 is provided in the vent line 23 of the pressure reducing valve 46, and a bypass line 40 is branched from the vent line 23 to the tank 20. Connected and a normally closed pilot operation switching valve 41 is provided in the bypass line 40. A pilot line 43 is connected to the pilot port of the pilot operation switching valve 41 from the normal rotation line 15 of the drill rotation motor 13 via the sequence valve 42.
[0028]
When the rotational resistance increases, the rotational torque of the drill rotation motor 13 increases and the pressure in the normal rotation line 15 increases to reach the pressure set in the sequence valve 42 in advance, so that the sequence valve 42 opens and the pilot operation switching valve. 41 is switched to the open side, the pressure in the forward pipeline 18 decreases, the thrust decreases, and jamming is avoided.
[0029]
1 and 2 does not forcibly stop the supply of pressure oil to the feed motor 7, so there is no residual pressure in the piping hose and good response to jamming. In addition, it is difficult for hydraulic equipment to undergo rapid pressure fluctuations, and impact and vibration can be suppressed and durability can be improved. In addition, since the number of parts is small and the circuit is simple, troubles can be reduced and costs can be reduced.
[0030]
【The invention's effect】
As described above, the punching machine jamming prevention device of the present invention can improve responsiveness to jamming without residual pressure in the piping hose by forcibly stopping the supply of pressure oil to the feed motor, In addition, sudden pressure fluctuations in hydraulic equipment are unlikely to occur, impact and vibration can be suppressed and durability can be improved. In addition, the number of parts is small, the circuit is simple, trouble is reduced, and costs can be reduced.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of an anti-jamming device for a punching machine according to an embodiment of the present invention.
FIG. 2 is a hydraulic circuit diagram of a jamming prevention device for a punching machine according to another embodiment of the present invention.
FIG. 3 is a side view of a guide shell of a crawler drill.
FIG. 4 is a side view of a guide shell of a down-the-hole drill.
FIG. 5 is a hydraulic circuit diagram of a jamming prevention device for a conventional drilling machine.
FIG. 6 is a hydraulic circuit diagram of a conventional jamming prevention device for a punching machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Guide shell 3 Rotation mechanism 7 Feed motor 8 Feed mechanism 13 Drill rotation motor 14 Rotation control valve 15 Forward rotation line 16 Reverse rotation line 17 Feed control valve 18 Advance line 19 Retreat line 20 Tank 21 Main relief valve 22 Relief pipe Line 23 Vent line 24 Pilot relief valve 40 Bypass line 41 Pilot operation switching valve 42 Sequence valve 43 Pilot line 44 Restriction 45 Return line 46 Pressure reducing valve

Claims (1)

A rotation mechanism and a feed mechanism are provided, a forward rotation line and a reverse rotation line are connected from the rotation control valve to the drill rotation motor of the rotation mechanism, and a forward line and a backward line are connected to the feed motor of the feed mechanism from the feed control valve. In connected drilling machines,
A pressure control valve with a vent is provided in the forward line of the feed motor, a normally closed pilot operation switching valve is provided in the vent line of the pressure control valve, and a normal rotation line of the drill rotation motor is provided in the pilot port of the pilot operation switching valve. A jamming prevention device for a drilling machine, characterized in that a pilot pipe line is connected through a sequence valve.

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