JPH053786Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of a shock absorber used in special vehicles such as tanks.

(Prior Art) Some shock absorbers used in special vehicles such as tanks are equipped with a locking mechanism to prevent the vehicle body from shaking due to the firing of the mounted gun, as shown in Figure 3. Utility Model No. 55-9921).

This is a piston 3 in which a piston rod 20 is connected to a seat pipe 2 erected inside a cylinder 1.
An oil reservoir chamber 5 is formed in the annular gap between the seat pipe 2 and the cylinder 1. It is defined into a chamber A and an oil chamber B on the opposite side. The piston 3 has a check valve 6 that allows hydraulic oil to flow from the oil chamber B to the oil chamber A.
However, check valves 7 are provided at the bottoms of the seat pipes 2 to allow the hydraulic oil in the oil sump chamber 5 to flow into the oil sump chamber B, and the hydraulic oil in the oil chamber A flows into the oil sump chamber 5 under a predetermined resistance. A damping valve 9 that allows oil to flow out is interposed in an oil passage 8 that communicates the oil chamber A and the oil reservoir chamber 5.

A cutoff valve 21 is interposed in the oil passage 8 on the upstream side of the damping valve 9 and opens and closes in response to pilot pressure introduced from the outside. A pilot passage 22 for guiding this pilot pressure is led from a pilot pressure supply device provided on the vehicle to a joint portion 23 provided on the outside of the bottom of the cylinder 1 through an external pipe (not shown), and further connected to an oil reservoir chamber 5 in the cylinder 1 via a pipe. A passage 24 runs through it and opens behind the isolation valve 21 .

In this shock absorber, the oil passage 8 is the only path for hydraulic oil to flow from the inside of the seat pipe 2 to the oil reservoir chamber 5, and the amount of hydraulic oil is the same whether the piston 3 slides toward the compression side or the expansion side. Hydraulic oil flows into the oil reservoir chamber 5 from the oil chamber A through the oil passage 8, and generates a damping force equal to expansion pressure at the damping valve 9 in the middle.

Furthermore, if pilot pressure is supplied from the outside via the pilot passage 22 to the shutoff valve 21 installed in the oil passage 8 to shut off the oil passage 8, the hydraulic oil in the seat pipe 2 will have no place to escape, so the piston 3 The sliding movement is locked in that position. When firing the mounted gun, this locks the expansion and contraction of the shock absorber, prevents the vehicle body from shaking due to recoil, and prepares for the next aim.

(Problems with the design) By the way, in this shock absorber, the pipe line 24 of the pilot passage 22 that supplies pilot pressure to the shutoff valve 21 is arranged inside the oil reservoir chamber 5, so the structure of the cylinder 1 becomes complicated. There was a problem. In addition, the external piping connected to the joint part 23 must be arranged so as not to interfere with the suspension spring disposed around the cylinder 1, and furthermore, it must be protected from damage because it is exposed to the outside. Consideration was necessary.

The present invention was made to solve these problems, and an object of the present invention is to provide a shock absorber with a lock in which a pilot passage is more rationally arranged.

(Means for Achieving the Object) The present invention divides the inside of a seat pipe erected inside a cylinder into an oil chamber A on the piston rod side and an oil chamber B on the opposite side by a freely sliding piston connected to a piston rod. An annular gap between the sheet pipe and the cylinder constitutes an oil reservoir chamber filled with gas.
The piston is provided with a check valve that allows hydraulic oil to flow from oil chamber B into oil chamber A, and a damping valve that allows hydraulic oil to flow out from oil chamber A to the oil reservoir chamber while generating a damping force, and from the oil chamber to the oil chamber. In a shock absorber equipped with a check valve that allows hydraulic oil to flow into B, a shutoff valve that opens and closes in accordance with pilot pressure is provided in series with the check valve provided on the piston, and pilot pressure is guided from the outside to this shutoff valve. A pilot passage is formed vertically through the piston rod.

(Function) The shutoff valve arranged in series with the check valve provided on the piston shuts off the oil flow from oil chamber B to oil chamber A according to the pilot pressure in the pilot passage, and locks the pressure side operation of the piston. .

In addition, the pilot passage that guides the pilot pressure from the outside to the shutoff valve is formed vertically through the piston rod, so it does not affect the structure of the cylinder. It does not interfere with the suspension springs etc. around the cylinder.

(Embodiment) FIGS. 1 and 2 show an embodiment in which the present invention is applied to a shock absorber for a tank. In addition, the first
The figure shows the shock absorber at maximum pressure.

1 is a cylinder, 2 is a seat pipe that stands coaxially inside the cylinder 1, 3 is a piston that is slidably inserted into the seat pipe, and 4 is a piston rod that is connected to the piston 3 and projects from the cylinder 1.

The inside of the seat pipe 2 is defined by the piston 3 into an oil chamber A on the piston rod 4 side and an oil chamber B on the opposite side, and these oil chambers A and B are filled with hydraulic oil. Further, an oil reservoir chamber 5 filled with gas is formed in an annular gap between the cylinder 1 and the seat pipe 2.

The piston 3 is provided with a check valve 6 that allows only the flow of hydraulic oil from the oil chamber B to the oil chamber A, and the bottom of the seat pipe 2 is provided with a check valve 6 that allows the hydraulic oil from the oil reservoir chamber 5 to flow into the oil chamber B. A check valve 7 is provided.
Further, an oil passage 8 is formed in the upper part of the cylinder 1 to communicate the oil chamber A and the oil reservoir chamber 5, and a damping valve 9 is interposed in the middle of this oil passage 8. The damping valve 9 is formed into a conical shape, and is seated on a valve seat 11 provided in the oil passage 8 by being biased by a spring 10 from the oil reservoir chamber 5 side.
This damping valve 9 opens in response to the rise in pressure in the oil chamber A.
Resistance is provided based on the spring load of the spring 10 against the flow of hydraulic oil from the oil chamber A to the oil reservoir chamber 5.

A pilot valve 12 is provided in series with the piston 3 as a shutoff valve on the oil chamber B side of the check valve 6. This pilot valve 12 is slidably fitted into an opening of a hollow piston rod 4, and is seated on a valve seat 14 formed in the piston 3 by being biased by a spring 13 from the oil chamber B side.

On the other hand, the pilot pressure that keeps the pilot valve 12 open against the spring 13 is guided through a pilot passage 15 formed through the hollow portion of the piston rod 4. The pilot passage 15 is pipe-connected to a pilot pressure supply source on the vehicle through the inside of a pin (not shown) that locks the eye bracket 16 at the proximal end of the piston rod 4 to the vehicle body. Note that this pilot pressure is transmitted by hydraulic oil in a system different from the hydraulic oil in the cylinder 1, and the supply and release of the pilot pressure is arbitrarily controlled from onboard the vehicle using a solenoid valve or the like. In addition, in order to prevent the hydraulic oil in the oil chamber B from mixing with the hydraulic oil in the pilot passage 15, the pilot valve 12 and the piston rod 4 are
A seal 17 is provided between the opening.

Next, the action will be explained.

Under normal conditions, pilot pressure is supplied to the pilot passage 15, and the pilot valve 12 is open against the force of the spring 13.

In this state, when the piston 3 moves to the pressure side,
The hydraulic oil in the contracting oil chamber B flows into the expanding oil chamber A through the check valve 6, and from the oil chamber A, the hydraulic oil corresponding to the intrusion volume of the piston rod 4 passes through the oil passage 8 and enters the oil sump chamber 5. It flows out and generates a compression damping force at the damping valve 9 in the middle.

When the piston 3 switches to expansion side operation, the check valve 6
is closed, the check valve 7 is opened, and the hydraulic oil in the oil sump chamber 5 flows into the expanding oil chamber B, and the hydraulic oil in the contracting oil chamber A flows out into the oil sump chamber 5 through the oil passage 8, and on the way The damping valve generates a rebound damping force. The outflow volume is equal to the volume of the piston rod 4 exiting the seat pipe 2. Therefore, the damping valve 9 equally resists the operation of the piston 3 on either the compression side or the expansion side, and changes the generated damping force depending on the operation speed.

On the other hand, when the mounted gun is used, the pilot pressure in the pilot passage 15 is released by an operation on the vehicle. This changes the pressure balance applied to the pilot valve 12, and the pilot valve 12 is urged by the spring 13 and seats on the valve seat 14. As a result, the hydraulic oil in the oil chamber B is prevented from flowing into the oil chamber A through the check valve 6, and the operation of the piston 3 on the pressure side is locked. Therefore, even if the recoil of the shot exerts a compressive force on the piston 3 via the piston rod 4, the shock absorber does not contract.
You can aim the next shot without shaking the vehicle. In this case, the extension side operation of the piston 3 is not regulated, but since the recoil of the shot acts as a compression side load on the shock absorber, prevention of vehicle body sway due to shooting can be sufficiently achieved only by locking the compression side operation. .

In this shock absorber, the pilot valve 12 is attached to the piston 3, and the pilot passage 15 is constructed inside the piston rod 4, so the cylinder 1 may have exactly the same structure as a shock absorber without a locking mechanism. In addition, the pilot passage 15 is connected via an eye bracket 16 and a pin to a pilot pressure supply source on the vehicle, and is not exposed around the cylinder 1.
There is no risk of interference with the suspension spring, and there is little risk of damage from collisions with foreign objects.

(Effects of the invention) As described above, the present invention provides a shutoff valve on the piston that opens and closes depending on the pilot pressure, and forms a pilot passage that passes through the piston rod vertically to guide this pilot pressure. This simplifies the configuration of the cylinder.

Furthermore, by guiding the pilot passage from the outside to the inside through the base end of the piston rod, interference between the pilot passage outside the shock absorber and members such as suspension springs around the cylinder can be avoided, and the arrangement of the pilot passage itself can be avoided. becomes easier.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a shock absorber showing an embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view showing the structure of the eye bracket at the proximal end of the piston rod, and Fig. 3 is a shock absorber showing a conventional example. FIG. 1...Cylinder, 2...Seat pipe, 3...
Piston, 4... Piston rod, 5... Oil reservoir chamber, 6, 7... Check valve, 8... Oil passage, 9...
...damping valve, 12...pilot valve, 15...
Pilot passage, A, B...oil room.

Claims (1)

[Scope of utility model registration request] A freely sliding piston connects a piston rod to the inside of a seat pipe installed upright inside the cylinder, creating an oil chamber A on the piston rod side and an oil chamber B on the opposite side.
An annular gap between the seat pipe and the cylinder constitutes an oil reservoir chamber filled with gas, and a check valve is provided on the piston to allow hydraulic oil to flow from oil chamber B to oil chamber A. In the shock absorber, the shock absorber is equipped with a damping valve that causes hydraulic oil to flow out from the oil reservoir chamber while generating a damping force, and a check valve that causes hydraulic oil to flow from the oil reservoir chamber into the oil chamber B, the check valve provided on the piston. A shock absorber with a lock, characterized in that a shutoff valve is provided in series with the piston rod to open and close according to pilot pressure, and a pilot passage for guiding pilot pressure from the outside to the shutoff valve is formed vertically through the piston rod.