JP2000130063A - Jamming prevention device for drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve responsiveness against jamming, eliminate abrupt pressure fluctuation of hydraulic equipment, reduce shocks and vibration, increase durability, simplify circuits, and reduce cost. SOLUTION: In a drilling machine in which a normal rotation pipe line 15 and a reverse rotation pipe line 16 are connected to a drill rotation motor 13 of a rotary mechanism from a rotation control valve 14, and an advancing pipe line 18 and a retreating pipe line 19 are connected to a feed motor 7 of a feeding mechanism from a feeding control valve 17, a main relief valve 21 with a vent is provided in the advancing pipe line 18 of the feed motor 7, and a pilot operation switching valve 41 usually opened is provided in a vent pipe line 23. A pilot pipe line 43 is connected to a pilot port of the pilot operation switching valve 41 through a sequence valve 42 from the normal rotation pipe line 15 of the drill rotation motor 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling machine such as a crawler drill or a down-the-hole drill, which prevents jamming by reducing the thrust of a feed mechanism when rotational resistance increases during drilling. A jamming prevention device.

[0002]

2. Description of the Related Art Drilling machines, such as crawler drills and down-the-hole drills, used for drilling in rock at quarries and mines, include a hitting mechanism and a rotating mechanism on a guide shell supported by a boom. , A feed mechanism.

For example, in a crawler drill, as shown in FIG. 3, a drifter 4 having a striking mechanism 2 and a rotating mechanism 3 is mounted on a guide shell 1 by a carriage 5 so as to be movable back and forth. And a feed chain 6 connected to the carriage 5.
A feed mechanism 8 comprising a feed motor 7 for driving the guide shell 1 is provided on the guide shell 1.

A rod 9 is inserted into the drifter 4, and a bit 10 is attached to the tip of the rod 9. The tip of the rod 9 is supported by a centralizer 11 provided at the tip of the guide shell 1. ing.

During 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 the impact and the rotation from the impact mechanism 2 and the rotation mechanism 3 to the bit 10 via the rod 9 to bore the rock.

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 in which the hitting mechanism 2, the rotating mechanism 3, and the feed mechanism 8 are provided on the guide shell 1.

When drilling a rock with such a drilling machine, where the rock is stable, the rotational resistance of the rod 9 and the bit 10 is small and the torque is stable, so that there is no hindrance to the drilling operation. .

[0008] However, for example, when drilling an unstable rock having a crush zone, a soft stratum, a crack or a cavity,
Bending of the hole or difficulty in discharging the dust increases the rotational resistance, so that the torque becomes unstable, and the rod 9 and the bit 10 cannot be collected by the rocks.
So-called jamming often occurs.

Therefore, the drilling machine is provided with a jamming prevention device as shown in FIGS. 5 and 6 in order to reduce the thrust of the feed mechanism 8 when the rotational resistance increases during drilling and to avoid jamming. Have been.

In the drilling machine, a rotation control valve 14 connects a forward rotation line 15 and a reverse rotation line 16 to a drill rotation motor 13 of a rotation mechanism 3. A forward control line 18 and a backward control line 19 are connected from the feed control valve 17. Further, the forward pipeline 18 and the tank 2
A relief line 22 having a vented main relief valve 21 is provided between the main relief valve 21 and a pilot relief valve 24 in a vent line 23 of the main relief valve 21. The main relief valve 21 adjusts the thrust of the feed mechanism 8 so that the forward conduit 18 of the feed motor 7
The operating pressure is remotely controlled by operating the handle 25 of the pilot relief valve 24.

The anti-jamming device shown in FIG. 5 uses the forward line 18 and the backward line 1 of the feed motor 7 in the above circuit.
A pilot operation switching valve 26 which is normally open is provided in the middle of 9,
A pilot port of the pilot operation switching valve 26 is connected to the sequence valve 2 from the forward rotation line 15 of the drill rotation motor 13.
7, the pilot line 28 is connected, and the rotational torque of the drill rotary motor 13 increases due to an increase in rotational resistance, and the pressure in the forward rotation line 15 increases to reach the pressure set in the sequence valve 27 in advance. Then, the pilot operation switching valve 26 is switched to the closed side, and the supply of the pressure oil to the feed motor 7 is stopped.

It should be noted that from the pilot line 28, a throttle 29
Is connected to the tank 20, and when the pressure in the forward rotation pipe 15 decreases, the pilot operation switching valve 26 is returned to the open side to supply the pressure oil to the feed motor 7. Let it resume.

In the anti-jamming device shown in FIG. 6, a communication line 31 is connected between the retreat line 19 of the feed motor 7 and the normal rotation line 15 of the drill rotation motor 13 to open a normally-open communication switching valve 32. A normally closed shut-off switching valve 33 is provided on the feed control valve 17 side of the retreat line 19 to apply the operating pressure on the forward rotation side of the drill rotation motor 13 to the back pressure of the feed motor 7 during forward movement, The thrust of the feed mechanism 8 is reduced by reducing the feed pressure of the feed motor 7 by increasing the pressure of the forward rotation pipe 15.

When an additional operation other than drilling is performed, for example, when the carriage 5 is retracted, the communication switching valve 32 and the shutoff switching valve 33 are switched to cut off the communication pipe 31 and to set the retreat pipe. 19 is communicated with the feed control valve 17.

[0015]

However, in the anti-jamming device shown in FIG. 5, when the pressure in the forward rotation line 15 of the drill rotary motor 13 increases due to an increase in rotational resistance, the pilot operation switching valve 26 is switched to forcibly. Since the supply of pressurized oil to the feed motor 7 is stopped, residual pressure remains in the pipe hose, and the timing at which the thrust decreases is actually slightly delayed, so that the sensitivity to jamming becomes slightly dull. It is easy to generate shock and noise due to sudden pressure fluctuation,
The service life of the hydraulic equipment may be shortened. In addition, since the pilot operation switching valve 26 must be provided directly in the forward pipe 18 and the backward pipe 19 of the feed motor 7, the apparatus tends to be large-scale.

On the other hand, in the anti-jamming device shown in FIG. 6, the communication switching valve 32, the shut-off switching valve 33, and the circuit for controlling the switching are performed so that ancillary work other than drilling, for example, retreat of the carriage 5, can be performed. (Electric or hydraulic) is required, which increases the cost. Further, at the time of drilling, the return of the feed motor 7 flows into the drill rotation motor 13 so that the rotation of the drill rotation motor 13 fluctuates and the drilling operation may become unstable. In addition, since it is necessary to provide the communication switching valve 32 and the shut-off switching valve 33 in the retreat line 19 of the feed motor 7, the device tends to be large-scale.

The present invention solves the above-mentioned problem in the anti-jamming device of a drilling machine, and there is no residual pressure in a piping hose due to forcibly stopping supply of pressurized oil to a feed motor. Response, and it is hard to cause rapid pressure fluctuation of hydraulic equipment, suppresses shocks and vibrations, and improves durability.Moreover, the number of parts is small, the circuit is simple, troubles are reduced and costs are reduced. An object of the present invention is to provide a jamming prevention device for a drilling machine that can be reduced.

[0018]

The anti-jamming device for a drilling machine according to the present invention is provided with a rotating mechanism and a feed mechanism, and a forward rotation pipe and a reverse rotation pipe are provided from a rotation control valve to a drill rotation motor of the rotation mechanism. In a drilling machine in which a feed control valve is connected to a feed motor of a feed mechanism and a forward control line and a reverse control line are connected from a feed control valve, a vented pressure control valve is provided in a forward control line of the feed motor, and A normally closed pilot operation switching valve is provided in the vent line, and a pilot line is connected to a pilot port of the pilot operation switching valve from a forward rotation line of the drill rotation motor via a sequence valve.

When performing a drilling operation, an operator operates a rotation control valve and a feed control valve to supply pressure oil to a drill rotation motor of a rotation mechanism and a feed motor of a feed mechanism, thereby forming a drill. Start. When the rotational torque of the drill rotary motor increases due to the increase in rotational resistance and the pressure in the forward rotation pipeline rises to reach the pressure set in the sequence valve in advance, the pilot operation switching valve is switched to the open side, and the forward pipeline is switched. The pressure is reduced, the thrust is reduced, and jamming is avoided.

When the rotational resistance decreases and the pressure in the forward rotation pipeline 15 decreases, the pilot operation switching valve returns to the closed side, and increases the pressure in the forward pipeline.

[0021]

FIG. 1 is a hydraulic circuit diagram of an anti-jamming device for a drilling machine according to an embodiment of the present invention.

The drilling machine is the same as the conventional one shown in FIG. 3, and includes a hitting mechanism 2, a rotating mechanism 3, and a feeding mechanism 8 on a guide shell 1. In this drilling machine, a rotation control valve 14 is provided to a drill rotation motor 13 of the rotation mechanism 3.
The forward rotation line 15 and the reverse rotation line 16 are connected to each other. The feed motor 7 of the feed mechanism 8 is connected to the forward line 18 and the backward line 19 from the feed control valve 17. Also,
A relief pipe line 22 is provided between the forward pipe 18 and the tank 20 with a vented main relief valve 21 interposed therebetween, and a pilot relief valve 24 is provided in a vent pipe 23 of the main relief valve 21. ing. The main relief valve 21 controls the pressure of the forward conduit 18 of the feed motor 7 in order to adjust the thrust of the feed mechanism 8.
The operating pressure is the handle 2 of the pilot relief valve 24.
5 is remotely controlled.

The vent line 2 of the main relief valve 21
3, a bypass pipe 40 is connected to the tank 20, and a normally operated pilot operation switching valve 41 is provided in the bypass pipe 40. Pilot operation switching valve 41
The pilot port of the drill rotation motor 13 is connected to the pilot port 4 through the sequence valve 42 via the sequence valve 42.
3 are connected. A return pipe 45 provided with a throttle 44 is connected to the tank 20 from the pilot pipe 43.

When drilling, 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. Feed and start drilling. The rotation torque of the drill rotation motor 13 increases due to the increase in the rotation resistance, and the pressure in the forward rotation pipeline 15 increases.
, The sequence valve 42 is opened, 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.

When the rotational resistance decreases and the pressure in the forward rotation line 15 decreases, the sequence valve 42 closes, and the oil in the pilot line 43 flows out of the return line 45 into the tank 20. 41 returns to the closing side to increase the pressure of the forward pipeline 18. Then, again, the pressure of the forward line 18 is changed to the handle 25 of the pilot relief valve 24.
Remote control by the operation of.

FIG. 2 is a hydraulic circuit diagram of an anti-jamming device for a drilling machine according to another embodiment of the present invention.

In this anti-jamming device, a pressure reducing valve 46 is provided in the middle of the forward pipe 18 in place of the main relief valve 21 of the anti-jamming device in FIG. Others are the same as those in FIG.
3, a pilot relief valve 24 is provided.
In addition, a bypass pipe 40 is connected to the tank 20 branching from the vent pipe 23, and a normally closed pilot operation switching valve 41 is provided in the bypass pipe 40. A pilot line 43 is connected to the pilot port of the pilot operation switching valve 41 from the forward rotation line 15 of the drill rotation motor 13 via a sequence valve 42.

When the rotation torque of the drill rotation motor 13 increases due to the increase in the rotation resistance and the pressure in the forward rotation pipe 15 increases to reach the pressure set in the sequence valve 42 in advance, the sequence valve 42 is opened and the pilot valve is opened. The 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.

The anti-jamming device of the drilling machine shown in FIGS. 1 and 2 does not forcibly stop the supply of pressurized oil to the feed motor 7, so that there is no residual pressure in the piping hose and the responsiveness to jamming is reduced. good. In addition, rapid pressure fluctuation of the hydraulic equipment is unlikely to occur, and impact and vibration can be suppressed to improve durability. In addition, since the number of parts is small and the circuit is simple, trouble occurrence can be reduced and cost can be reduced.

[0030]

As described above, the anti-jamming device of the drilling machine according to the present invention has no residual pressure in the pipe hose by forcibly stopping the supply of pressurized oil to the feed motor, and has no response to jamming. Characteristics, and it is hard to cause rapid pressure fluctuation of hydraulic equipment, suppresses shocks and vibrations, improves durability, and has fewer parts, simpler circuit, less trouble, and lower cost. .

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of an anti-jamming device for a drilling machine according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram of an anti-jamming device for a drilling machine according to another embodiment of the present invention.

FIG. 3 is a side view of a guide shell of the crawler drill.

FIG. 4 is a side view of a guide shell of the down-the-hole drill.

FIG. 5 is a hydraulic circuit diagram of a conventional anti-jamming device for a drilling machine.

FIG. 6 is a hydraulic circuit diagram of a conventional anti-jamming device for a drilling machine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 guide shell 3 rotation mechanism 7 feed motor 8 feed mechanism 13 drill rotation motor 14 rotation control valve 15 forward rotation path 16 reverse rotation path 17 feed control valve 18 forward path 19 retreat path 20 tank 21 main relief valve 22 relief pipe Road 23 Vent line 24 Pilot relief valve 40 Bypass line 41 Pilot operation switching valve 42 Sequence valve 43 Pilot line 44 Restrictor 45 Return line 46 Pressure reducing valve

Claims (1)

[Claims] 1. A rotary mechanism and a feed mechanism, wherein a forward rotation pipe and a reverse rotation pipe are connected from a rotation control valve to a drill rotation motor of the rotation mechanism, and a feed control valve is connected to a feed motor of the feed mechanism from a forward pipe. In the drilling machine connected with the retraction line, a pressure control valve with a vent is provided in the forward line of the feed motor, and a normally closed pilot operation switching valve is provided in the vent line of the pressure control valve. A jam prevention device for a drilling machine, wherein a pilot line is connected to a pilot port of a switching valve from a forward rotation line of a drill rotation motor via a sequence valve.