JPH0240158Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic strut, and more particularly to a hydraulic strut that can prevent internal oil from leaking to the outside when the hydraulic strut is tilted.

Hydraulic supports installed inside tunnels and mines during tunnel excavation and coal mining use hydraulic pressure from oil etc. to expand. The required amount of oil, etc. must be available. For hydraulic struts that store this desired amount of oil within the strut, it must be possible to prevent the internal oil from leaking to the outside, not only when the strut is in use, but also when it is not in use. Must be.

By the way, when the hydraulic strut is not in use, it is generally tilted and placed horizontally, and at that time oil leaks from the inside. Therefore, it is possible to equip the hydraulic support with an appropriate oil leakage prevention device, and to prevent oil leakage by manually operating the device when not in use. If you sometimes forget to operate the system, there is a risk that you will not be able to prevent oil leaks.

Therefore, the present invention has developed a new hydraulic column that can be activated without manual operation to prevent oil leakage when the hydraulic column is tilted to be placed horizontally when not in use. The purpose is to provide.

In order to achieve this objective, the configuration of the present invention includes a cylinder body having a core equipped with a hydraulic pump and a release valve in the intermediate body, and a cylinder body that is slidably inserted into the cylinder body from the lower end of the cylinder body. and a rod body having a piston at its upper end that slides into contact with the internal circumferential surface of the cylinder, and supplies pressurized oil into the lower oil chamber formed between the lower end surface of the core and the upper end surface of the piston by the operation of the hydraulic pump. In the hydraulic strut, the cylinder is formed so that the pressure oil in the lower oil chamber is discharged to the oil reservoir chamber above the core and contracted by the operation of a release valve. A shutoff valve is installed at the upper end of the body to prevent oil in the oil reservoir inside the cylinder from leaking to the outside when the hydraulic column is tilted.
The shutoff valve is characterized by having a valve body, a spring that biases the valve body in a closing direction, and a section body that is swingably suspended from the valve body and pulls the spring in a contraction direction. It is.

Hereinafter, the present invention will be explained based on the illustrated embodiments.

As shown in FIG. 1, the hydraulic strut according to the present invention consists of a cylinder body 1 and a rod body 2. The cylinder body 1 has a core 3 in its intermediate body and a shutoff valve 4 in its upper end. are doing. The rod body 2 is slidably inserted into the cylinder body 1 from the lower end thereof.

A bearing member 1b having a seal 1a therein is screwed onto the lower end of the cylinder body 1 to ensure sliding of the rod body 2 with respect to the cylinder body 1. Further, the upper end of the cylinder body 1 is provided with a cylinder body 1.
A head member 1c is fixed so as to seal the inside, and allows the upper end of the cylinder body 1 to come into contact with the ceiling of the tunnel. The cylinder body 1 has an oil reservoir chamber A defined inside thereof by the upper end head member 1c and the intermediate body core 3.

The rod body 2 has a piston 2a at its upper end, and the piston 2a has a piston ring 2b around its upper end. The lower end of the piston 2a is connected to the rod body 2 by a pin 2c passing through the lower end. Further, the outer periphery of the upper end of the piston 2a is formed with a notch, so that an annular oil chamber B is formed between the piston 2a and the inner peripheral surface of the cylinder body 1. The piston 2a has its upper end surface adjacent to the lower end surface of the core 3 when the hydraulic strut is in its most contracted state, but as the hydraulic strut expands, the piston 2a It separates from the end face and forms a lower oil chamber between the lower end face of the core 3 and its upper end face. In addition, at the lower end of the rod body 2,
A bottom member 2d is fixed, allowing the lower end of the hydraulic column to come into contact with the bottom surface of the tunnel.

The core 3 includes a hydraulic pump 10 therein, and a relief valve 20 communicating with the hydraulic pump 10.
and a release valve 30. Then, by the operation of the hydraulic pump 10, the cylinder body 1
The piston 2a is forcibly lowered by supplying oil from the oil sump chamber A inside the annular oil chamber B into the annular oil chamber B, thereby supplying a desired amount of oil into the lower oil chamber formed inside the rod body 2. This is intended to extend the hydraulic strut. Furthermore, the oil in the lower oil chamber in the rod body 2 is returned to the oil reservoir chamber A in the cylinder body 1 by the operation of the release valve 30, thereby attempting to contract the hydraulic strut. In addition, relief valve 2
0 is configured to operate when the lower oil chamber formed in the rod body 2 reaches a predetermined oil pressure or higher when the hydraulic pump 10 is operated. The high-pressure oil is returned to the oil reservoir chamber A inside the cylinder body 1.

As shown in FIG. 2, the hydraulic pump 10 has a plunger 11 slidably disposed within an oil chamber 3a formed within the core 3.
The plunger 11 has an oil passage 13 that allows communication between the pump chamber 12 at the tip of the oil chamber 3a, which is the high pressure side, and the oil reservoir chamber A, which is the back pressure side. has a suction valve 14.

The plunger 11 moves forward and backward within the oil chamber 3a by raising and lowering a handle H connected to the rear end protruding outside the core 3, and is moved back and forth within the oil chamber 3a through a through hole drilled in the core 3. The oil in the oil reservoir chamber A flows into the oil chamber 3a through the hole 3b, and the oil flowing into the oil chamber 3a during the forward movement is transferred to the core through the pump chamber 12 and the port 3c formed in the core 3. 3. The oil is discharged into the annular oil chamber B below.

Note that the hydraulic pump 10 has a check valve mechanism 1.
5, when the plunger 11 moves backward, the communication between the pump chamber 12 and the port 3c is cut off, but when the plunger 11 moves forward, the pump chamber 12 and the port 3c are communicated with each other. Furthermore, the pump chamber 12 is formed to have a predetermined volume by a cap 16 screwed onto the core 3, and by screwing the cap 16, The internal volume of the pump chamber 12 can be made variable.

As shown in FIG. 2, the relief valve 20 includes a valve body 21 adjacent to an outlet of an oil passage 3d bored in the core 3 so as to communicate with a port 3c communicating with the hydraulic pump 10, body 21 to oil passage 3c
It comprises a spring 22 biased toward the outlet and a cap 23 screwed onto the core 3 and capable of changing the repulsive force of the spring 22 by external operation. Then, a hydraulic pressure is applied to the oil passage 3 that overcomes the spring 22 whose repulsive force is adjusted by an external operation and causes the valve body 21 to retreat.
d, high pressure oil from the hydraulic pump 10 bleeds off toward the oil sump chamber A.

As shown in FIG. 3, the release valve 30 includes a valve body 31 adjacent to an opening of an oil passage 3e formed in the core 3 and communicating with the oil reservoir chamber A;
1 toward the opening of the oil passage 3e, and a cap 33 that is screwed onto the core 3 and whose repulsive force can be changed by external operation. is needle-shaped operating rod 3
1a are arranged in series, and their tips protrude outside the core 3. In addition, the valve body 31 and the spring 32 are arranged in an oil chamber 3f bored in the core 3, and the oil chamber 3f communicates with the oil passage 3e and is bored in the core 3. It also communicates with a lower oil chamber formed below the core 3 via the oil passage 3g.

A rotating portion 34 of an operating lever L, which is energized by an appropriate means outside the core 3, is adjacent to a protruding portion of the needle-shaped operating rod 31a connected to the valve body 31 to the outside of the core 3. There is. The rotating portion 34 is eccentrically mounted, and its rotation pushes the needle-shaped operating rod 31a into the core 3. That is, the valve body 3
1 from the opening of the oil passage 3e.
This is to move the inside of f backward.

Therefore, when there is oil in the lower oil chamber formed below the core 3, when the lever L is operated, the lower oil chamber is filled with oil passages 3g, 3f, and 3e.
The oil in the lower oil chamber is discharged into the oil reservoir A, and the hydraulic strut contracts.

The shutoff valve 4 includes a sleeve 41 fixed to the upper end side wall of the cylinder body 1, and a sleeve 41 fixed to the upper end side wall of the cylinder body 1.
a nut 43 that fixes the rear end of the housing 42 in the sleeve 41; A valve body 44 is disposed in the atmospheric passage 42a and is capable of cutting off communication between the inside of the oil reservoir chamber A and the outside via the atmospheric passage 42a, and a repulsion force is provided to support the valve body 44 and to support the valve body 44. The passage 4 is opened by the valve body 44.
a spring 45 formed to block communication between the inside of the oil reservoir chamber A and the outside via the valve body A; and a spring 45 that is swingably suspended from the valve body 44.
It consists of a split barrel 46 that pulls the cylinder in the direction of contraction. Note that an air filter 47 is disposed between the rear end of the housing 42 and the nut 43 adjacent thereto.

The opening of the housing 42 in the cylinder body 1 opens toward the lower oil level a, that is, downward, and the spring 45 is disposed within the downward opening. and,
The valve body 44 is formed to have a top-like shape as a whole, and its shaft portion 44a is disposed within the downward opening and is connected to the spring 45. Then, the flange-like portion 44 of the valve body 44
A sealing member 44b' such as a rubber plate is provided on the upper surface of the oil reservoir chamber A to block communication between the inside of the oil reservoir chamber A and the outside when it is adjacent to the downward opening. In addition, in this embodiment, the housing 42
A plate 42b is attached to the edge of the downward opening, and the sealing member 44 is attached to the plate 42b.
By crimping b', care is taken to ensure that the container is sealed.

The split barrel 46 is swingably suspended from the lower end of the shaft portion 44a of the valve body 44 via a chain or the like, and at least when its entire weight acts on the valve body 44, the above-mentioned spring The valve body 44 is pulled down by overcoming the repulsive force of the valve body 45. That is, the brim portion 44b of the valve body 44 is connected to the plate 42.
b, and the inside of the oil sump chamber A and the outside are brought into communication via the atmospheric passage 42a.

On the other hand, when the hydraulic strut is tilted, the split barrel 46 will be suspended in the perpendicular direction regardless of the tilted state of the cylinder body 1.
If it is tilted at a certain angle or more, it will be adjacent to the inner circumferential surface of the cylinder body 1. As a result, as shown in FIG. 4, component forces W _V and W _H are generated with respect to the gravity W of the split barrel 46. If the tilt angle of the cylinder body 1 increases, the horizontal component force W _H increases and the vertical component force W _V decreases, and the repulsive force F of the spring 45 exceeds this vertical component force W _V. In this case, the valve body 44 closes the downward opening of the atmospheric passage 42a.

Note that the nut 43 has a through hole 4 in its center.
3a is formed to communicate the atmosphere between the oil reservoir chamber A in the cylinder body 1 and the outside.

As configured as described above, the hydraulic column according to the present invention can prevent internal oil from leaking to the outside even if the column is tilted when not in use. In addition, the shutoff valve that prevents oil from leaking to the outside does not require manual operation, and is automatically activated when the hydraulic support column is tilted at a certain angle or more. There is no possibility of inconveniences such as oil leakage caused by forgetting to operate the hydraulic column and placing it horizontally. Furthermore, since the shutoff valve of the present invention does not use expensive electronic parts and has a simple structure, there is no drawback that the installation of the hydraulic valve would make the hydraulic strut extremely expensive.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a hydraulic strut according to an embodiment of the present invention, FIG. 2 is a plan cross-sectional view of the hydraulic pump and relief valve indicated by the line - in FIG.
The figure is a longitudinal sectional view of the release valve indicated by the line - in FIG. 2, and FIG. 4 is an explanatory diagram schematically showing the operating state of the cutoff valve. 1... Cylinder body, 2... Rod body, 2a...
Piston, 3...Core, 4...Shutoff valve, 10
... Hydraulic pump, 20 ... Relief valve, 30
...Release valve, 42 ...Housing, 42
a... Atmospheric passage, 44... Valve body, 45... Spring, 46... Branch barrel, A... Oil reservoir chamber, B... Annular oil chamber.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A cylinder body having a core equipped with a hydraulic pump and a release valve in the intermediate body, and a cylinder body that is slidably inserted into the cylinder body from the lower end thereof, and the upper end thereof. It consists of a rod body with a piston that slides on the inner peripheral surface of the cylinder, and when the hydraulic pump is operated, pressure oil is supplied into the lower oil chamber formed between the lower end surface of the core and the upper end surface of the piston. In a hydraulic strut that is formed to extend and to contract by discharging the pressure oil in the lower oil chamber to the oil reservoir chamber above the core by operating a release valve, the upper end of the cylinder body A shutoff valve is installed in the section to prevent the oil in the oil reservoir inside the cylinder from leaking to the outside when the hydraulic support column is tilted, and the shutoff valve includes a valve body and a spring that biases the valve body in the closing direction. 1. A hydraulic strut characterized by having a half body which is swingably suspended from the body and which pulls the spring in the contraction direction. (2) The hydraulic strut according to claim 1, wherein the shutoff valve is formed so as to shut off communication between the atmosphere inside the oil reservoir and the outside atmosphere when the shutoff valve is activated. (3) The shutoff valve has an atmospheric passage that allows communication between the oil reservoir chamber and the outside, and has a valve body in the atmospheric passage that is energized by a spring and can shut off the atmospheric passage. The hydraulic strut according to claim 1, wherein the valve body is formed to block the atmospheric passage when the hydraulic strut is tilted.