JPS5818195B2 - hydraulic breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement in a hydraulically operated hydraulic breaker for concrete and rock crushing.

This applicant has already provided Japanese Patent Application No. 51-017670 as a new structure and configuration of a hydraulic breaker.

・In order to facilitate the explanation of this invention, the above-mentioned patent application 1972-
The gist of 017670 will be briefly illustrated in FIG. 1 and the following description.

FIG. 1 is a cross-sectional view showing the gist of Japanese Patent Application No. 51-017670, in which the hydraulic circuit is indicated with JISBO 125 hydraulic and pneumatic symbols.

1 is a striking piston, and the upper and lower parts are central pistons 2 (
The upper piston 3 has a small diameter (D2) and the lower piston 4 has a medium diameter (D3).

- The main body 5 is provided with a cylinder chamber 6 in which the striking piston 1 can be stored, and the striking piston 1 is installed so that it can be stored vertically.

As shown in the figure, a fluid source 9 branches off from a fluid source 9 and hydraulic pressure is directly introduced into a lower chamber 7 formed between a cylinder chamber 6 of the main body 5 and the striking piston 1.
It is designed to prevent leakage between the piston and the piston and to provide an upward thrust to the striking piston 1.

A fluid source 9 is connected to an upper chamber 8 formed in the upper part of the cylinder chamber 6 by the impact piston 1 via a control valve 10 as shown.

The function of the control valve 10 is a 3-port switching valve, and when the impact piston 1 descends to the lower end, the fluid in the upper chamber 8 led through the guide hole 11 switches the control valve 10 and moves the control valve 10 to the discharge position 12. The switch is switched, and the fluid in the upper chamber 8 is discharged.

In this state, the striking piston 1 rises due to the fluid pressure acting on the lower chamber 7, and when it reaches the upper end, the guide hole 13
The control valve 10 is switched to the supply position 14 by the hydraulic pressure guided to the control valve 10, fluid is supplied to the upper chamber 8, a downward thrust is generated in the striking piston 1 due to the relationship D3>D2, and the striking piston 1 is descend.

In this way, in the structure and configuration shown in FIG. 1, the striking piston 1 vibrates up and down due to the hydraulic pressure.

The chisel 15 is struck, and the chisel 15 crushes concrete and rocks.

This kind of hydraulic breaker (mainly uses hydraulic pressure discharged by a hydraulic pump, so it is called a hydraulic breaker).

), the inertia energy of the vertical movement of the striking piston 1 is effectively used, the pulsation of the hydraulic pressure is minimized, the accumulators 16 and 17 provided in the circuit are made small, and the hydraulic energy is used effectively. Therefore, a gas chamber 18 is provided in the upper part of the main body 5, and as the upper piston 3 rises, the sealed gas in the gas chamber 18 is compressed, and when the striking piston 1 descends, the compressed pressure of the filled gas is also added to the downward thrust. The above-mentioned patent application No. 51-017 made it look like a vine.
It is 670.

In addition, as shown in FIG. 2 (longitudinal cross-sectional view), the structure and configuration shown in FIG. A method of vibrating the striking piston 21 by supplying and discharging hydraulic pressure is also used.

In FIG. 2, 23 is the upper piston, 25 is the main body, and 28
The upper chamber 38 is a gas chamber, and 29 is a hydraulic pressure source.

However, for such a gas chamber 18 or 38, there is an optimum volume and an optimum pressure corresponding to the volume, and the volume includes friction loss (loss due to fluid flow).

) is ignored, the compression energy L in the gas chamber 18°38 and the fluid pressure are determined as the point where the energy E consumed in the upward stroke of the striking pistons 1, 21 becomes equal, so PV-PV L-□ ・・・・・・・・・・・・・・・・(A)■-γ Pl ・・・・・・Pressure in the gas chamber at the lower end of the striking piston (filling pressure) vl ・・・・・・At the lower end of the striking piston Volume of the gas chamber P2...Pressure inside the gas chamber at the upper end of the striking piston■2...Volume γ inside the gas chamber at the upper end of the striking piston...Polytropic index or E=P-8・-(Dl"-D,')-W-S...
......(B)P...Liquid pressure S...Stroke of striking piston W...
・It is the weight of the striking piston, and according to the gas law, P1v1γ−P2v2γ・・・・・・・・・・・・・・・
(Since ■, L=E and find ■1, P2V2
-P1V1=-(D,"-D,')P-8-...-
...(D)P' yr (P2 (Hiro)-P, )v1=7(D1'-p,')
P-3-w・5-4(D1′-D,7)-p-s-w-
s■=□・・・・・・・・・(E) I L P γ P2 (piece) − Pl.

The optimum volume is obtained by setting Pl to atmospheric pressure in equation (E).

(The reason will be explained later) When this optimum volume is actually calculated, the volume becomes close to the piston displacement amount of the upper piston 3 or 23 at the preferred hydraulic pressure and the size of the striking pistons 1, 21.

In other words, the size is extremely close to the minimum size of the temple provided in the main body 5.

On the other hand, if the volume inside the gas chamber 18 or 38 is small, some gas leakage will occur due to the vertical vibration of the striking piston 1 or 21, but due to this influence, the gas pressure sealed in the gas chamber 18 or 38 will gradually decrease. It goes down.

□If the gas chambers 18 and 38 are large, even if there is some gas leakage, the gas pressure will not be affected greatly, but if the gas chambers 18 and 38 are small, even a slight leakage will have a large effect on the gas pressure. The operating period after filling with gas is short, and gas filling must be performed again.

In this invention, the volume of the gas chambers 18, 38 may be extremely small for efficient operation, but the gas chambers 18, 38 may be made large for long gas filling gaps and convenient use. Overcome the correlation of wanting to.

The reason why the maximum efficiency is achieved when the gas chamber 18.38 becomes close to the minimum volume, that is, the displacement amount (piston diameter x stroke) of the upper pistons 3 and 23, is as follows.
be easily understood.

That is, if the gas chambers 18, 38 are of infinite size, the pressure in the gas chambers 18, 38 is equal to the striking piston 1, 38.
There is no change even with the vertical movement of 21.

Therefore, the effect of the presence of the gas chamber 18.38 is simply to increase the downward thrust, i.e. in the example of FIG.
Either the diameter D3 of the striking piston 1 is made large enough to correspond to the downward thrust, or the weight of the striking piston 1 is simply increased by an amount corresponding to the downward thrust.

Also, in FIG. 2, the weight of the striking piston 21 is increased or a part of the hydraulic pressure is used as a downward thrust as shown by the chain line 40 in FIG.
the percussion piston 1 in reversal from the upward direction to the downward direction at the upper end of the stroke of the percussion piston 1 or 21;
The inertia of 21 means that the hydraulic pressure is reversed when the control valve 10 or 30 is reversed.
It is absorbed by the hydraulic pressure acting on the upper chamber 8.

However, as an extreme example, if the gas chamber 18.38 is made to have a volume corresponding to the displacement of the pistons, the striking pistons 1 and 2
1 is at the lower end, the gas chamber 1838 is assumed to be at atmospheric pressure.[As the volume of the gas chamber 1838 increases, the sealing pressure increases, and it is preferable to decrease the pressure, which is optimal for the size of the gas chamber. Pressure is hydraulic pressure, central piston 2
, converges to a constant value determined by the upper piston 3 and the lower piston 4.

] With such a configuration, when the striking piston 1.21 starts from the lower end, there is no downward thrust due to gas pressure, so it easily accelerates and rises rapidly.

Gas pressure increases as it rises, and at top dead center gas chamber 1
Since the volume of 8.38 becomes zero, the gas pressure becomes infinite, and the rising energy of the striking pistons 1 and 21 is completely converted into gas pressure, which is used as the initial downward thrust when the piston 1.21 descends. .

Of course, in reality, it is not possible to make the volume of the gas chambers 18, 38 equal to the amount of piston displacement and raise the gas pressure to infinity, but it is possible to increase the volume of the gas chambers 18, 38 from infinity to the amount of piston displacement. If we consider the period up to the equivalent displacement, if it is infinite, the repulsive force of the gas cannot be used, and a downward thrust is always generated, whereas the gas chamber 18
When the volume of .degree. 38 becomes smaller, the gas pressure increases as the stroke of the striking piston 1 increases, and the upward inertial force of the striking piston 1 is converted into gas pressure, which can be used downward.

In other words, it can be understood that the repulsion based on gas compression becomes effective.

To give an actual example, D,=16.5crrLD2=15,
5CrrLD3=15,0crILP=1'40K
yf/era S=10cra W=100
In Kyf, the optimal volume V, = 1935cni.

At this time, the piston displacement amount is 1887 cTA, and the volume of the gas chamber at the top dead center of the striking piston is 48 cI + ¥
becomes.

In this invention, as shown in FIG. 3 (cross-sectional view of main parts), a second gas chamber 60 is provided in addition to the small-capacity waste chamber 48 in the main body 45, and the gas chamber 48 and the second gas chamber 60 are arranged as appropriate. If you contact us with a valve, please contact us.

As mentioned above, the optimal volume of the gas chamber is the addition of a very small volume to the piston displacement, but the value that regulates the right is that when the striking piston 43 is at the lower end, the piston Let's say that it is within twice the amount of displacement.

The valve connecting the gas chamber 48 and the second gas chamber 60 is preferably one that opens when the striking piston 41 reaches the lower end and is closed at other positions; for example, in the example shown in FIG. 41 descends and reaches the lower end, the tip of the upper screw I/N 43 of the striking piston 41 opens the guide hole 61, and when the upper piston 43 rises, the guide hole 61 opens.
is closed, and only the gas in the gas chamber 48 reaches the upper piston 4.
3, and the gas in the second gas chamber 60 is not compressed.

The volume of the gas chamber 48 is reduced to the optimum volume, and the second
If the volume of the gas chamber 60 is made sufficiently large compared to the rate of consumption due to gas leakage, etc., the gas in the gas chamber 48 will be compressed, and even if the gas is exhausted, when the upper piston 43 reaches the lower end, the gas inside the gas chamber 60 will be compressed. of gas is automatically supplemented, and in response to gas consumption, the size of the gas chamber 48 becomes equivalent to the volume of the gas chamber 48 and the second gas chamber 60,
It is also possible to compress an optimal volume of gas with the upper piston 43 so that the sealing pressure does not decrease over a long period of time and the repulsion due to gas compression can be effectively utilized.

As shown in FIG. 4 (longitudinal sectional view of the main part), a check valve 62 is used as a valve that communicates the gas chamber 48 and the second gas chamber 60 to close the flow from the gas chamber 48 to the second gas chamber 60. The gas chamber 48 may be provided so as to be able to flow from the second gas chamber 60.

In this way, when the upper piston 43 reaches the lower end, if the gas in the gas chamber 48 has been exhausted and the pressure has decreased below the pressure in the second gas chamber 60, the gas will pass through the reverse valve 62. When the gas chamber 48 is refilled and the upper piston 43 rises to compress the gas in the gas chamber 48, the check valve 62 is closed and only the gas in the gas chamber 48 is compressed, so the gas chamber 48 reaches its optimum volume. If so, the compressibility of the gas can be effectively utilized, and the period during which gas needs to be replenished due to gas consumption can be extended.

FIG. 5 (longitudinal cross-sectional view of the main part) shows that instead of providing a second gas chamber 60 inside the main body 45 as shown in FIG. This shows an example in which the gas cylinders are connected and used as a second gas chamber, and the same effect as explained in FIG. 3 above can be obtained.

Further, FIG. 6 (a vertical sectional view of the main part) shows the second gas chamber 60 [provided in the main body 45] described in FIG.

] was connected from the gas chamber 48 to the cylinder 68 through piping 65, 66, and a check valve 67 was provided in the middle of the piping 65, 66.

It is easy to understand that the same effect as shown in FIG. 4 can be obtained even in this manner.

In the example shown in FIG. 6, conventional practice has been to introduce the pressure reduced from a cylinder through a pressure reducing valve to the gas chamber through piping.

(Refer to Japanese Patent Publication No. 49-29801.) In this case, as shown in this invention, the gas chamber was not so small that there was no big difference in displacement from the piston, but the gas chamber was considerably large compared to the displacement of the piston. However, there has never been an example in which the gas chamber is small and the cylinder and the gas chamber are connected only by a check valve, and a pressure reducing valve is not provided in between.

As described above, according to the present invention, it is possible to effectively utilize the repulsion due to gas compression, and furthermore, it is possible to extend the refilling period due to gas consumption.

[Brief explanation of drawings]

1 and 2 are longitudinal cross-sectional views of a conventional embodiment, FIG. 3 is a longitudinal cross-sectional view of main parts of an embodiment of the present invention, and FIGS. 4 and 5.
FIG. 6 is a longitudinal cross-sectional view of a main part of another embodiment of the present invention. Next, 1 is a striking piston, 2 is a central piston, 3 is an upper piston, 4 is a lower piston, 5 is a main body, 6 is a cylinder chamber, 7 is a lower chamber, 8 is an upper chamber, 9 is a fluid source, 10 is Control valve, 11 is a guide hole, 12 is a discharge position, 13 is a guide hole, 14
is the supply position, 15 is the chisel, 16 is the accumulator, 1
7 is an accumulator, 18 is a gas chamber, 21 is a striking piston, 23 is an upper piston, 25 is a main body, 27 is a lower chamber, 28 is an upper chamber, 29 is a hydraulic pressure source, 30 is a control 38 is a gas chamber, 40 is a chain line, 41 is a striking piston, 43 is an upper piston, 45 is a main body, 48 is a gas chamber, 60 is a second gas chamber, 61 62 is a guide hole, 62 is a check valve, 63 is a pipe, 64 is a cylinder, 65 is a pipe, 66 is a pipe, 67 is a check valve, and 68 is a cylinder.

Claims (1)

[Scope of Claims] 1. In a hydraulic breaker that compresses and expands gas in a gas chamber provided at the upper part of the striking piston by a striking piston vibrated by hydraulic pressure, and utilizes the compressive repulsion of the gas, the displacement of the piston is determined. A hydraulic breaker, characterized in that a second gas chamber is provided in addition to the gas chamber having a volume within twice that of the first gas chamber, and the gas chamber and the second gas chamber are connected through a valve. 2. The hydraulic breaker according to claim 1, wherein the gas chamber provided in the main body and the second gas chamber are connected by a valve that opens only when the striking piston reaches the lower end. 3. The hydraulic breaker according to claim 1, wherein the gas chamber provided in the main body and the second gas chamber are connected by a guide hole that opens only when the striking piston reaches the lower end. 4. The hydraulic breaker according to claim 1, wherein the gas chamber provided in the main body and the second gas chamber are connected through a check valve. 5. The hydraulic breaker according to claim 1, wherein a cylinder is used as the second gas chamber, and the second gas chamber is connected to a guide hole that opens only when the striking piston reaches the lower end. 6. The hydraulic breaker according to claim 1, wherein a cylinder is used as the second gas chamber, the second gas chamber is connected to the gas chamber through piping, and a check valve is provided in the middle of the piping.