JPH0716797Y2 - Strike auxiliary device for hydraulic drifter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a striking assist device for a hydraulic drifter.

(Prior Art) Conventionally, for example, in order to make a hole for inserting dynamite in rock, a device has been put into practical use in which a hydraulic drifter is advanced by a feed cylinder while striking a shank rod having a bit with a piston. There is.

(Problems to be solved by the invention) By the way, when a hydraulic drifter is retracted by a feed cylinder after making a hole in a rock, a bit or the like catches on the hole wall and the shank rod cannot be pulled out from the hole. There is.

Therefore, in the reverse impact device for rod withdrawal of impact tool in JP-A-61-240496, the accumulator is pressurized by switching the switching valve and the hydraulic drifter is advanced, and then the shank rod is struck by the main piston to drive the auxiliary rod. The piston is moved forward together with the piston, and then the auxiliary piston is moved backward by the pressure oil of the accumulator to strike the shank rod in the reverse direction.

However, a striking operation such as switching operation of the switching valve or forward operation of the hydraulic drifter is necessary.

The present invention has been made to solve the above problems, and an object thereof is to automatically strike the shank rod when the shank rod is difficult to pull out, thereby eliminating the need for a striking operation. .

(Means for Solving the Problem) Therefore, according to the present invention, a hydraulic cylinder including a shank rod, a piston that strikes the shank rod, and a slide stopper that stops the front slide of the shank rod is moved forward by a feed cylinder. In the device for retracting the slide stopper, an auxiliary hydraulic passage for supplying hydraulic pressure for moving the slide stopper backward is provided, and when the feed cylinder retracts, the hydraulic pressure in the main hydraulic passage for retracting the feed cylinder has a predetermined value. It is characterized in that a valve that opens when the above is reached is provided.

(Operation) Move the hydraulic drifter backward by the feed cylinder,
When pulling the shank rod out of the hole, if the bit catches on the wall of the hole, etc., the load increases the hydraulic pressure in the main hydraulic passage beyond a specified value to open the valve, and the hydraulic pressure to move the slide stopper backward is supplied from the auxiliary hydraulic passage. It

As a result, the shank rod is retracted from the foremost moving position, and the shank rod can be hit by the piston.

(Effect of the Invention) According to the present invention, when the shank rod is difficult to pull out from the hole, the shank rod is automatically hit, so that hitting operation unlike the conventional case is unnecessary, and the shank rod is pulled out. Can be done easily and quickly.

Further, basically, since the auxiliary hydraulic passage having the valve is simply connected to the main hydraulic passage, the structure is simple and the operation can be surely performed.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in the figure, the hydraulic drifter 10 is connected to the feed cylinder 11, and when the main switching valve 12 is switched to the first valve 12a, hydraulic pressure is supplied from the forward hydraulic passage 13a to the rear chamber 11a of the feed cylinder 11. Then, the hydraulic drifter 10 is moved forward, and conversely, when the main switching valve 12 is switched to the second valve 12b, the front chamber 1 of the feed cylinder 11 is moved from the backward hydraulic passage 13b.
The hydraulic pressure is supplied to 1b, and the hydraulic drifter 10 is retracted.

In addition, 14 is a hydraulic pump, 15 is a return tank, and 16 is a relief valve.

The hydraulic drifter 10 includes a horizontally long tubular body 20,
A front head 21 is fixed to the front part.

The flange portions 24a, 24b of the gear 24 are rotatably supported by the bearing sleeves 22, 23 in the body 20.
Is meshed with a gear 27 of a shaft 26 that is rotatably supported by a bearing sleeve 25 in the body 20.
Is rotated by a motor (not shown), and the gear 27 rotates the gear 24
Is designed to be rotated.

Center holes 24c, 24d, 2 are formed in the gear 24 and the flange portions 24a, 24b.
4e is open. A chuck jaw 29 is non-rotatably fitted in the center hole 24c on the flange 24a side, and the center hole on the gear 24 side is
A bushing 30 is fitted to 24d.

A spline 29a is formed on the inner peripheral surface of the chuck jaw 29.

On the other hand, in the shank rod 31, the rear portion 31a has the bushing 3
The front part 31b is supported by the center hole 21a of the front head 21.
Supported by.

The shank rod 31 is formed with a spline 31c that meshes with the spline 29a of the chuck jaw 29.

A slide stopper 32, through which the shank rod 31 penetrates, is fitted in the front head 21 so as to be slidable forward and backward, and is biased by a coil spring 33 that is compressed between the shank rod 31 and the flange portion 24a of the gear 24 to move to the forward movement position. Have been hit by.

A gap t is formed between the slide stopper 32 and the chuck jaw 29 so that the slide stopper 32 can move backward.

In the shank rod 31, the rear end portion 31d of the spline 31c is stopped by the bushing 30 to restrict the rearward moving position, and the front end portion 31e of the spline 31c is stopped by the slide stopper 32 to restrict the forward moving position. The stroke S can be moved back and forth.

A piston 35 that strikes the shank rod 31 is fitted to the rear portion of the body 20.

The piston 35 strikes the shank rod 31 with a stroke S.

In other words, when the shank rod 31 is at the foremost moving position, even if the piston 35 is hit, the shank rod 31 is not hit because it does not contact the rear end surface of the shank rod 31.

A hydraulic chamber 36 is formed between the slide stopper 32 and the front head 21, and the front chamber 21 has a hydraulic chamber 36.
The hydraulic port 21b leading to is opened.

The hydraulic port 21b is connected to the hydraulic pump 14 by an auxiliary hydraulic passage 37, and a switching valve 38 is provided in the auxiliary hydraulic passage 37.

The switching valve 38 is switching-controlled by a pilot valve 39 that opens when the hydraulic pressure in the reverse hydraulic passage 13b reaches or exceeds a predetermined value, and when the pilot valve 39 opens, the hydraulic pressure of the hydraulic pump 14 is changed to the hydraulic chamber 36. Is switched to supply.

With the above-mentioned configuration, the main switching valve 12 is replaced by the first valve 12
Switch to a and feed cylinder from forward hydraulic passage 13a.
Hydraulic pressure is supplied to the rear chamber 11a of the chamber 11 to move the hydraulic drifter 10 forward.

In the hydraulic drifter 10, the motor rotates the gear 27 together with the shaft 26, and the shank rod 31 is rotated via the gear 24 and the chuck jaw 29. At the same time, the piston 35 strikes the shank rod 31 to move back and forth with a stroke S.

As a result, the bit of the shank rod 31 makes a hole in the rock.

After finishing the drilling work, set the main switching valve 12 to the second valve 12b.
When switched to, hydraulic pressure is supplied from the reverse hydraulic passage 13b to the front chamber 11b of the feed cylinder 11, and the hydraulic drifter 10 is retracted. As a result, the shank rod 31 is pulled out from the rock hole.

At this time, if the bit or the like is caught in the hole wall and it becomes difficult to pull out the shank rod 31 from the hole, when the shank rod 31 is hit by the piston 35, the catch becomes dislodged and pulled out easily.

However, since the shank rod 31 is pulled to the foremost moving position, the shank rod 31 is not hit even if the piston 35 is hit.

Therefore, when it becomes difficult to pull out the shank rod 31, the backward movement of the feed cylinder 11 due to the load thereof
Since the hydraulic pressure of the pilot valve rises above the specified value, the pilot valve 39
Is opened, the switching valve 38 is switched, and the hydraulic pressure of the hydraulic pump 36 is transferred from the auxiliary hydraulic passage 37 to the hydraulic port 21 of the front head 21.
It is supplied to the hydraulic chamber 36 through b.

As a result, the slide stopper 32 is moved backward by the clearance t, the shank rod 31 is moved backward accordingly, and the rear end surface of the shank rod 31 approaches the piston 35 by the distance S '.

Therefore, the striking operation of the piston 35 causes the shank rod 31
Will be hit and the catch will come off, making it easier to pull out the shank rod 31 from the hole in the rock.

As described above, according to the present embodiment, when the shank rod 31 is difficult to pull out from the hole, the pilot valve 39 is opened by detecting the increase in the hydraulic pressure in the reverse hydraulic passage 13b, the switching valve 38 is switched, and the auxiliary valve is switched. Hydraulic pressure is supplied from the hydraulic passage 37 to the hydraulic chamber 36, and the shank rod 31 is moved backward together with the slide stopper 32, so that the piston 35 is automatically hit.

Therefore, the hitting operation as in the prior art is unnecessary.

[Brief description of drawings]

FIG. 1 is a sectional view and a circuit configuration diagram of a hydraulic drifter according to the present invention. 10 ... Hydraulic drifter, 11 ... Feed cylinder, 13b ... Reverse hydraulic passage, 20 ... Body, 21 ... Front head, 31 ...
Shank rod, 32 ... slide stopper, 35 ... piston, 37 ... auxiliary hydraulic passage, 38 ... switching valve, 39 ... pilot valve.

Claims (1)

[Scope of utility model registration request] 1. A device for advancing and retracting a hydraulic drifter comprising a shank rod, a piston for striking the shank rod, and a slide stopper for stopping the front slide of the shank rod by a feed cylinder. An auxiliary hydraulic passage for supplying a hydraulic pressure to be moved backward is provided, and a valve that opens when the feed cylinder retracts and the hydraulic pressure in the main hydraulic passage for retracting the feed cylinder reaches or exceeds a predetermined value is provided in the auxiliary hydraulic passage. A striking assist device for a hydraulic drifter.