JP2537370B2 - Hydraulic impact tool - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an impact tool for a rock drilling machine that drills a hole to be drilled in a rock or the like horizontally and vertically.

[Conventional technology]

Conventionally, in the above rock drilling machine, when the drilling rod of the rock drilling machine is jammed due to sand clogging or the like during drilling work, it becomes extremely difficult to pull out this drill rod from the drilling hole. To solve this problem, for example, a hydraulic control circuit for a rock drill disclosed in Japanese Patent Laid-Open No. 58-58390 is known.

That is, in the hydraulic control circuit of the impact tool that transmits impact force / rotational force / feed force to the drill rod by each hydraulic actuator, the forward feed of the rod feed hydraulic actuator is detected by detecting an increase in the rotational torque of the rod rotation hydraulic actuator. In order to weaken the force or to switch the forward feed of the feed hydraulic actuator to stop feed or reverse feed to pull out the rod when the amount of increase in the rotation torque increases above a predetermined value, depending on the oil pressure in the forward rotation side oil passage. A relief valve for relieving the oil pressure in the forward oil passage and a control valve for supplying the oil pressure in the forward oil passage to the backward oil passage in accordance with the oil pressure in the forward oil passage are provided.

[Problems to be solved by the invention]

According to the hydraulic control circuit of the rock drill, the jamming phenomenon can be prevented to some extent by setting the set pressure for relief from the relief valve and the set pressure for switching the control valve.

However, once the jamming phenomenon occurs, it is impossible to pull out the drill rod unless a large vibration or a shocking pulling force is applied to the drill rod. In the conventional device, the drill rod is pulled out by the vibration when the attack piston moves in and out of the damper chamber by reciprocally moving the attack piston while driving the drill rod backward through the drill body and the drifter. In some cases, sufficient vibration cannot be obtained by the above vibration alone, and it may be difficult to pull out the drill rod.

[Means for solving problems]

A hydraulic attack tool according to the present invention includes a cylinder formed in a striking tool body, a striking piston axially slidably mounted in the cylinder and having a piston-shaped large diameter portion, and a striking piston of the cylinder. A damper chamber that is formed in front of the piston-shaped large-diameter portion to store hydraulic oil, and into which the piston-shaped large-diameter portion of the striking piston can enter during idle driving, and a rear part of the cylinder in front of the striking piston front end A shank rod that is inserted and mounted slidably in the direction, and that has a locking step portion that is located in the cylinder,
A contact member axially slidably mounted in the cylinder in front of the locking step portion of the shank rod and capable of contacting with the locking step portion of the shank rod, and in the cylinder in front of the contact member. A working chamber formed in the working chamber, a piston member slidably mounted in the working chamber in the axial direction and capable of contacting the abutting member, which is integral with or separate from the abutting member, the working chamber and the damper chamber. And an oil passage for causing the hydraulic pressure of the hydraulic oil in the damper chamber to act on the piston member during idle driving to move the contact member in the backward direction of the shank rod.

[Operation] In the hydraulic attack tool according to the present invention, when the drill rod is jammed due to sand clogging or the like in the hole to be drilled during drilling work, a reciprocating motion is repeated in the axial direction in the cylinder. The piston-shaped large-diameter portion of the piston repeatedly projects into the damper chamber, and the hydraulic oil in the damper chamber is pressurized by the piston-shaped large-diameter portion. Since the working oil in the damper chamber is communicated with the working chamber via the oil passage, the above-mentioned impact hydraulic pressure acts on the working chamber to cause the piston member to expel a large hydraulic pressure in the retracting direction of the shank rod. It At this time, since the attack tool main body is driven to the retreating side and the locking step portion and the contact member are in contact with each other, the shocking pressing force of the piston member is applied to the shank rod via the contact member. As a result, the shank rod is repeatedly subjected to a shocking pulling force.

〔The invention's effect〕

According to the hydraulic attack tool of the present invention, as described above, when the drill rod is in a jamming state where it cannot be pulled out due to sand clogging or the like in the hole to be covered, the impact piston repeatedly reciprocates. With shock, the shocking hydraulic pressure propagating from the damper chamber to the working chamber repeatedly strikes the shank rod backwards via the piston member and abutting member, so that the drill rod is more efficient and reliable than the sand-filled cover hole. Can be pulled out.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the whole rock drilling machine according to the present embodiment, in which a traveling carriage 2 is mounted on traveling wheels 1 as a traveling device, and a traveling member 2 is mounted in front of and below a traveling member 2 through a supporting member 3. A boom 4 that can swing in the left-right direction is attached.

The boom 4 is movable by a boom lift cylinder 5 and a zoom swing cylinder (not shown), and a guide cell 7 is connected to a free end of the boom 4 via a rotary pivot shaft 6.

The guide cell 7 is configured to be movable up and down and left and right by a cell lift cylinder 9 stretched between a back surface of the guide cell 7 and a bracket 8 formed integrally with the boom 4 and a cell swing cylinder (not shown). Has been done.

A drifter (hydraulic attack tool) 10 is mounted on the guide cell 7 so as to move forward and backward, and the drifter 10 is driven forward and backward along the guide cell 7 by a feed cylinder 15 provided on the lower surface side of the guide cell 7 at a high speed. At the same time, it is driven back and forth along the guide cell 7 during drilling through a hydraulic motor and a chain mechanism provided inside the guide cell 7,
A drill rod 13 is attached to 10 via a shank rod 11 and a connecting member 12, a bit 14 is attached to the tip of the drill rod 13, and an attacking force / rotational force is applied to the bit 14 by the above-mentioned drifter 10. It is configured so that a hole to be covered can be formed.

The tip portion of the drill rod 13 is supported by a centralizer 16, while a hood pad 17 is arranged at the tip portion of the guide cell 7, and the hood pad 17 has a hood 18 for collecting dust.
Is installed.

The hood 18 has a structure in which the drill rod 13 is inserted in the center thereof, and the hood 18 is provided with a suction duct 19 communicating with a dust collector (not shown).

Next, the structure of the drifter 10 will be described with reference to FIGS.

In the above-mentioned drifter 10, the first, second, third, and fourth cylinder housings 28a, 28b, 28c, and 28d, which form a cylinder 28 formed horizontally in the length direction, are integrally fixed through bolts and nuts. Is formed.

In the first cylinder housing 28a, a striking piston 30 which can be hydraulically driven forward and backward through the oil chambers 21 and 22 by switching the valve mechanism 20 is provided so as to slide in the cylinder 28. Here, the drive mechanism of the valve mechanism 20 and the piston 30 is the same as that of an ordinary rock drill, and thus the description thereof is omitted.

Further, a cylindrical shaft-shaped rotation chuck 38 is disposed inside the second cylinder housing 28b and the third cylinder housing 28c, and a driven gear 39 is integrally formed on the rotation chuck 38. This driven gear 39
It is meshed with a driving gear 25 driven via a drive shaft 24 of a hydraulic motor 23 provided at the rear end of the first cylinder housing 28a. A chuck jaw 41 having a spline hole 40 or a spiral spline on its inner surface is connected to the tip of the rotation chuck 38.

Further, the rotation chuck 38, the chuck jaws 41, and the fourth cylinder housing 28d arranged in the second cylinder housing 28b and the third cylinder housing 28c.
The rear part of the shank rod 11 is axially slidably and movably disposed inside the spline, and a spline integrally formed on the outer peripheral surface of the locking stepped part 42 of which the shank rod 11 has a partially enlarged diameter. The teeth 43 are the spline holes 40 of the chuck jaws 41.
Is engaged.

Further, inside the front portion of the rotation chuck 38, the shank rod 11 is retracted when the shank rod 11 retreats.
A cylindrical shaft-shaped chuck bushing 44 is mounted that abuts on the rear end portion 42a of the locking step portion 42 of 11 and regulates the retreat limit position.

A housing portion 45a having a diameter larger than that of the locking step portion 42 is formed at the front end portion of the third cylinder housing 28c, and the locking step of the shank rod 11 when the shank rod 11 is advanced into the housing portion 45a. A ring-shaped contact member 45 that contacts the front end portion 42b of the portion 42 and regulates the advance limit position is slidably mounted in the shank rod advancing / retracting direction, and the contact member 45 is the accommodation portion 45a.
It is formed shorter than the axial direction.

Fourth cylinder housing 28d on the front side of the contact member 45
Has four cylinder holes 46a axially formed at four circumferential positions, and a piston 47 is axially slidably mounted in each cylinder hole 46a.
A hydraulic cylinder 46 is formed by the piston 47 and each piston 47, and each piston 47 can contact the front end surface of the contact member 45. A portion of the cylinder hole 46a in front of the piston 47 is a pressurizing working chamber 48. An annular communication passage 48a for communicating the four pressurizing chambers 48 is formed in the fourth cylinder housing 28d at a position corresponding to the outer peripheral portion of the front end of the pressurizing chamber 48.

Further, the striking piston 30 has a piston-shaped large-diameter portion 30a.
Is formed in the first cylinder housing 28a, and in the axial direction of the piston 30 at a position where the piston 30 can enter when the piston 30 advances in front of the piston-shaped large-diameter portion 30a.
Are formed. The damper chamber 50 communicates with the oil passage 51.
It communicates with the pressurizing working chambers 48 of the four cylinders 46 via 48a, and working oil is stored in these chambers.

Further, the piston 30 and the shank rod 11 have axial ends that penetrate through them in the longitudinal direction, and further communicate with the air passages inside the connecting member 12 and the drill rod 13 to the tip of the bit 14. Air passage for ejecting compressed air
An air passage 31 and an air passage 33 are provided respectively and are connected to each other via a connecting pipe 32. The air passage 31 is connected to an air supply device (not shown) through a port 34 provided in the first cylinder housing 28a on the rear end side of the piston 30 and an air supply port 36 provided outside the housing via an air passage 35. ing.

Next, the operation of the rock drill constructed as above will be described.

When the guide cell 7 and the drill rod 13 are oriented vertically as shown in FIG. 1 and the hole 15 is vertically drilled with the bit 14, or the guide cell 7 and the drill rod 13 are shown in FIG. When the driving gear 25 is rotated by the hydraulic motor 23 when drilling sideways as shown by the phantom line, this rotational force is transmitted to the shank rod 11 through the rotation chuck 38 and the spline hole 40 of the chuck jaw 41. Is
The shank rod 11 is rotationally driven.

Further, the reciprocating motion of the piston 30 is transmitted to the shank rod 11 by the reciprocating motion of the piston 30 by switching the valve mechanism 20. Therefore, the shank rod 11 receives a reciprocating striking force in addition to the rotational driving force,
Attack force and rotation force are added to the bit 14 to punch the covered hole.

By the way, when the shank rod 11 is jammed due to sand clogging or the like in the hole to be covered, the drifter 10 is driven backward, and the piston-shaped large-diameter portion 30a of the piston 30 advances and retracts into the damper chamber 50 of the cylinder 28. The vibration generated by repeating the above action acts on the shank rod 11, and at the same time, every time the piston-shaped large-diameter portion 30a rushes into the damper chamber 50, the hydraulic oil in the damper chamber 50 is shocked and pressurized, Through the oil passage 51 and the communication passage 48a to the pressurizing working chamber 4 of the cylinder 46.
The piston 47 of the cylinder 46 is shock-pushed to the retracting side of the shank rod 11, that is, the pulling-out side, by propagating to the hydraulic fluid 8 of FIG. As a result, the piston 47 impacts the abutting member 45, and the abutting member 45 repeatedly strikes the front end portion 42b of the locking step portion 42 of the shank rod 11.

As a result of the above, sand or the like that has been jammed in the drill hole can be reliably removed, and the drill rod 13 that cannot be pulled out from the drilled hole portion in the jamming state can be efficiently and reliably pulled out.

It should be noted that four or more hydraulic cylinders 46 may be provided in the above embodiment, or these hydraulic cylinders 46 may be integrated to form a hydraulic cylinder composed of an annular cylinder hole and an annular piston. The hole and the accommodating portion 45a may be configured to communicate with each other so that the contact member 45 receives pressure, that is, the contact member 45 also serves as an annular piston.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a rock drilling machine, FIG. 2 is a partially cutaway vertical side view of a drifter (hydraulic attack tool) of the rock drilling machine, and FIG. It is a principal part expanded sectional view of FIG. 10 …… Drifter (hydraulic attack tool), 11 …… Shank rod, 28 …… Cylinder, 30 …… Piston, 30a …… Piston-shaped large-diameter part, 42… Locking step part, 45 …… Contact member, 47 ……
Piston, 48 ... Pressure working chamber, 50 ... Damper chamber, 51 ...
… Oil passage.

Claims (1)

(57) [Claims] 1. A cylinder formed in a striking tool body, a striking piston axially slidably mounted in the cylinder and having a piston-shaped large diameter portion, and a piston-shaped large striking piston of the cylinders. A damper chamber is formed in front of the diameter part where hydraulic oil is stored, and the piston-shaped large-diameter part of the striking piston can enter at the time of idle driving, and the rear part axially slides forward from the tip of the striking piston in the cylinder. A shank rod movably inserted into the cylinder and provided with a locking step located in the cylinder; and a shank rod axially slidably mounted in the cylinder in front of the locking step of the shank rod. An abutting member capable of abutting against the locking step portion, an operating chamber formed in the cylinder in front of the abutting member, and an abutting member slidably mounted in the operating chamber in the axial direction. A piston member which can be contacted and is integral with or separate from the contact member, and the working chamber and the damper chamber are communicated with each other, and the hydraulic pressure of the working oil in the damper chamber acts on the piston member at the time of idle driving to shank the contact member. A hydraulic impact tool comprising: an oil passage for moving the rod in the backward direction.