JPS5923953B2 - Hydraulic rock drill dry-driving prevention mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanism for preventing dry-driving of a rock-drilling rock, and more particularly to a mechanism for preventing dry-driving of a rock-drilling rock suitable for use in a rock-drilling using hydraulic pressure.

In general, pneumatic and hydraulic rock drills are used for the purpose of directly crushing rocks, and hydraulic rock drills in particular do not require a compressor and do not produce exhaust noise, making them effective as a countermeasure against noise pollution. Therefore, it has become widely used in recent years.

Generally speaking, these crushers apply blows to the material to be crushed several to several times per second, but operational errors and
Due to the cracking of the material to be crushed, the tip of the chisel repeats the striking action even after separating from the material to be crushed, causing a self-destructive action called dry striking in which the winding machine itself is struck with a strong striking force.

If this dry firing occurs frequently, the life of the rock drill will be significantly shortened, and unpleasant vibrations will be transmitted to the operator, reducing work efficiency.

The present invention aims to improve the above-mentioned drawbacks and provide a hydraulic rock drill equipped with a dry striking prevention mechanism that automatically stops striking when the tip of the chisel separates from the object to be crushed due to an operational error or the like. That is.

Hereinafter, the present invention will be explained in detail by way of an example.

1 and 2 show one embodiment of the present invention.
The figure shows a state in which a strike has been completed during normal operation, and FIG. 2 shows a state in which the hammer is pushed up by pressure oil and the energy for striking is stored to the maximum.

1 and 2, a hammer 32 that slides up and down inside the main body case 31 is connected to a compression elastic body 54 (a fixed spring such as a coil spring, etc.) inserted between the main body case 31 and The lower end of the chisel 33 is normally pressed against the upper end of the chisel 33 by an elastic body such as a liquid spring such as a hydraulic spring or a gas spring using nitrogen gas or the like.

A hydraulic chamber 35 formed by a hammer 32 and the main body case 31 is provided in the middle part of the main body case 31.
By injecting pressure oil from 6, the compressive force of the compressible elastic body 54 can be overcome and the hammer 32 can be raised.

A valve case 37 is fixed to the outside of the main body case 31, and inside the valve case 37, the pressure oil injected from the oil filler port 38 is sent to the valve spool portion 48 by sliding up and down.
and a valve 4 which can introduce pressure oil into the hydraulic chamber 35 through the cuff 36 or discharge the pressure oil from the hydraulic chamber 35 to the outside through a valve cone portion 49 from the drain oil 39.
0 is smoothed together.

A piston 41 is provided at the top of the valve 40, and a compression spring 55 such as a coil spring or a gas spring is provided between the top of the piston 41 and the valve case 37. 49 to valve seat 5
1, the press-down oil drain port 39 is closed, the valve spool portion 48 is opened, and the oil supply port 38 and the cuff 36 are communicated with each other.

The hammer 32 is provided with a hammer spool portion 56, which guides the pressure oil from the valve oil supply port 30 to the valve oil pressure chamber 59 or drains the pressure oil from the valve oil pressure chamber 59 according to the vertical movement of the hammer 32. It has a function of discharging the oil to the outside from the oil port 34.

Next, the operation of the hydraulic type Sabi Iwatsuki constructed as described above will be explained.

First, in FIG. 1, when pressurized oil is supplied to the oil filler port 38 and the valve oil filler port 30 by an appropriate hydraulic source (not shown), the pressure oil from the oil filler port 38 passes through the valve spool portion 48 of the valve 40 and is then hydraulically It flows into the chamber 35, overcomes the spring force of the compression elastic body 54, the frictional force between the hammer 32 and the main body case 31, etc., and begins to push the hammer 32 upward.

At this time, since the valve oil supply port 30 is closed by the hammer 32, pressure oil does not flow into the valve hydraulic chamber 59 and the valve 40 does not rise.

Next, as shown in FIG.
When the hammer 32 is raised sufficiently until the oil is accumulated at 4, the upper end of the nozzle spool 56 opens into the valve oil supply port 30, and the pressure oil passes through the hammer spool 56 and the valve cuff 60 and suddenly increases the valve oil pressure. It flows into the chamber 59, overcomes the spring force of the compression spring 55, and rapidly pushes the valve 40 upward.

This operation closes the valve spool part 48 of the valve 40 and opens the conical part 49 (When the conical part 49 opens, the pressure oil in the hydraulic chamber 35 is rapidly discharged from the oil drain port 39, and the hammer 32 is released very quickly. The energy accumulated in the compressed elastic body 54 descends at a high speed and applies a powerful impact force to the chisel 33, thereby crushing the rock 53 and the like to which the chisel 33 is applied.

During the downward stroke of the hammer 32, the hammer spool portion 5
Since the oil in the valve hydraulic chamber 59 is not discharged until the lower end of the valve 6 reaches the valve oil drain port 34, the valve 40 is held in an upwardly pushed state, and therefore the valve cone portion 49 remains open. The oil is continuously drained from the hydraulic chamber 35, and there is little resistance to the lowering of the hammer 32.

However, when the lower end of the hammer spool portion 56 reaches the valve oil drain port 34 and the pulp cuff 60 and the valve oil drain port 34 are brought into communication via the hammer spool portion 56,
The pressure oil in the valve hydraulic chamber 59 is rapidly pushed out by the compression spring 55, so the valve 40 is lowered, the valve cone portion 49 is closed, and then the valve spool portion 48 is opened and the valve 40 is seated on the valve seat 51, as shown in FIG. Return to initial state.

Since pressure oil is constantly supplied from the oil supply port 38 and the valve oil supply port 30, the hammer 32 and the valve 40 repeatedly perform the above operations, and the hammer 32 is connected to the chisel 33.
The rock 5 at the tip of the chisel 33
3rd grade can be crushed.

What has been described above is the operation when the main body case 31 is pressed by external force so that the tip of the chisel 33 is always in contact with the object to be crushed, such as the rock 53. When the tip of the chisel 33 separates from the rock 53 due to such reasons, the state generally appears as shown in FIG. 3.

That is, the tip of the hammer 32 does not reach the rear end of the chisel 33, and the shoulder 61 of the hammer 32 touches the shoulder 62 of the main case 31.
will be hit.

However, in the present invention, as shown in FIG. 3, the valve cuff 60 connected to the valve hydraulic chamber 59 is closed by the )-arm 32, so that the pressure oil in the valve hydraulic chamber 59 has no outlet. The valve remains confined within the hydraulic chamber 59.

Therefore, the valve 40 cannot be lowered, and the communication between the fuel filler port 38 and the cuff 36 is cut off.
Pressure oil cannot flow into the hydraulic chamber 35.
...The hammer 32 cannot rise, and the continuous hitting operation stops, thereby reliably preventing dry hitting.

As described above, in order to prevent dry firing, in the normal stopped state shown in FIG. It is necessary that the distance to the shoulder 62 is greater than that of the shoulder 62.

According to the present invention, by simply continuing the supply of pressure oil to the valve hydraulic chamber with the pump itself, without any special additional equipment, it is possible to easily provide a dry firing prevention function. It has the effect of significantly extending the lifespan, and also has the effect of increasing work efficiency without causing discomfort to the operator due to dry firing.

Furthermore, since the dry firing prevention mechanism does not include any fragile elements such as springs or poppet valves, it has the advantage of being extremely easy to maintain.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views showing a hydraulic rock drill according to an embodiment of the present invention. Figure 1 shows the state where the impact has been completed in a normal state, and Figure 2 shows the energy storage. Indicates the condition. FIG. 3 shows a state in which the dry striking prevention mechanism is activated and the striking is stopped. Explanation of symbols, 30... Valve oil filler port, 31...
・・・Body case, 32・・・・・・・・・Mer, 3
3... Chisel, 34... Valve oil drain port, 35... Hydraulic chamber, 37... Valve case, 38... Fuel filler port. , 39... Oil drain port, 40... Valve, 53... Rock,
56・・・・・・・Nmarspool Club, 61・・・・・
...Shoulder of the hammer, 62...Shoulder of the main case.

Claims (1)

[Claims] 1 A hammer that slides up and down is installed inside the main body case, and the hammer is moved upward by pressure oil, and moved downward by a compression elastic body that is compressed as the hammer moves upward. In a hydraulic rock drill that is configured to strike a chisel, the movement of the valve that controls the supply and discharge of the pressure oil is controlled by the pressure oil supplied and discharged by the vertical movement of the hammer, and the hammer does not strike normally. 1. A hydraulic rock-pounding tool, characterized in that when the hammer descends beyond a certain position, draining of oil from the valve is stopped, thereby preventing the hammer from hitting the rock-pounding body in a dry manner.