JPH0115580Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a shock absorbing support device for various devices that buffers and supports an idler, etc. that supports the crawler of a tracked vehicle.

(Prior Art) To explain conventional examples of tracked vehicles, they are run and used in various environments such as dirt, rock, ice, asphalt roads, etc., or a combination of these. Due to the harsh working environment, the external force acting on the crawler or idler changes significantly, and in some cases, the crawler may come off the rails or be damaged, so the idler is provided with a shock absorbing support device.

As shown in FIG. 2, a conventional example of the buffer support device includes an outer cylinder 2 with an injection valve 2a attached to a track frame 1 of a tracked vehicle, and an outer cylinder 2 fitted in the outer cylinder 2 and injected from the injection valve 2a. an inner cylinder 3 that is slid by an incompressible fluid (e.g., grease) a; A piston 4 disposed in the inner cylinder 3, supported by the elastic body b, and elastically supporting a support body 5 of an idler 6 via a piston rod 4a, a lid portion 3a of the outer cylinder 2 and the inner cylinder 3. The inner cylinder 3 includes an elastic body b having fluidity from the injection valve 3b.
The incompressible fluid a is injected into the outer cylinder 2 from the injection valve 2a to push out the inner cylinder 3 in the longitudinal direction, and the piston 4 passes through the piston rod 4a to the support of the idler 6. 5, and the piston 4 is supported and buffered by the internal pressure of a fluid elastic body b sealed in the inner cylinder 3.

In addition, the elastic body b (for example, silicone rubber) that has fluidity and is sealed in the inner cylinder 3 is generally used under a certain initial volume as shown in FIG. + (initial force) and (K
is an elastic constant), in other words, (internal pressure of the inner cylinder 3) = K x (displacement) + (initial internal pressure), and the internal pressure of the inner cylinder 3 is proportional to the amount of displacement of the piston 4. There is.

(Problems with the prior art) Generally, the fluid elastic body b has a high bulk elasticity coefficient of 20,000 (Kg), for example, silicone rubber.
f/cm ² ), the ratio of the pressure change to the volume change of the elastic body is extremely large, making it difficult to obtain the appropriate cushioning performance required by the cushioned support, that is, the mother machine (tracked vehicle). In addition, if the displacement of the piston becomes abnormally large, the internal pressure of the inner cylinder may exceed the descending stress of the cylinder, and the shock absorbing support device itself or the shock absorbing support body may be damaged. To counter this, it is necessary to increase the wall thickness of the cylinder or to perform special heat treatment, which increases costs. Furthermore, the elastic body b generally has a large thermal expansion, which causes the internal pressure of the inner cylinder to change as the environmental temperature changes, resulting in a disadvantage that the shock-absorbing performance is significantly reduced depending on the environment in which it is used.

(Purpose of the invention, means for solving problems) This invention is an invention to deal with the above-mentioned problems in the conventional shock absorbing support device. an inner cylinder that is slid by a fluid; a piston of the inner cylinder that is disposed in the inner cylinder and supported by an elastic body of a fluid enclosed in the inner cylinder and elastically supports a support body to be cushioned; The piston is characterized by a structure including a sub-piston fitted on the elastic body side of the piston so as to be retractable and protruded by an adjustment spring, and the sub-piston is fitted on the elastic body side of the piston of the inner cylinder so as to be reciprocatable. Moreover, due to the structure in which the sub-piston is made to protrude by an adjustment spring,
By replacing the adjustment spring, the internal pressure of the elastic body can be adjusted, and the expansion and contraction of the elastic body, that is, the increase and decrease of the internal pressure, caused by changes in the temperature of the environment can be adjusted by automatically moving the sub piston back and forth. To provide a shock absorbing support device which eliminates the above-mentioned problems of the conventional technology by making it possible to absorb and adjust the shock absorbing and adjusting properties of the device, thereby preventing damage to the device and significantly improving durability, reliability, and shock absorbing support performance. It is in.

(Embodiment of the invention) Fig. 1 shows an embodiment of the invention, in which a support body 5 of an idler 6 supporting a crawler 7 in a tracked vehicle is cushioned and supported. As an example of a shock absorbing support device, reference numeral 1 in the figure is a track frame of a tracked vehicle, and an outer cylinder 2 with an injection valve 2a is fitted to the end of the track frame 1. An inner cylinder 3 that is slid with an incompressible fluid a such as grease is fitted inside the inner cylinder 3, and an injection valve 3b is attached to the lid 3a of the inner cylinder 3. An elastic body b having fluidity as shown in FIG. It's structured well. moreover,
A sub-piston 10 is fitted on the elastic body a side of the piston 4 so as to be movable forward and backward, and is projected toward the elastic body b side by a coil spring, that is, an adjustment spring 11. In addition, in the figure, 4b is a sliding hole for the sub-piston 10 provided in the inner cylinder 4, and 4c is a sliding hole for the sub-piston 10.
Reference numeral 8 indicates an air intake/exhaust hole of the sliding hole 4b, and 8 indicates a seal provided on the lid portion 3a of the outer cylinder 2 and the inner cylinder 3.

(Function) The embodiment of the present invention has the above-mentioned configuration, and the required amount of the elastic body b having fluidity is injected and sealed into the inner cylinder 3 from the injection valve 3b,
When an incompressible fluid a (for example, grease) is injected into the outer cylinder 2 from the injection valve 2a, the inner cylinder 3 is pushed out in the longitudinal direction and its piston 4
is resiliently supported by the support body 5 of the idler 6 via the piston rod 4a, and can be cushioned and supported, and the inner cylinder 3 is supported by the incompressible fluid a.
The installation length can be freely changed by extruding.

When an external force acts on the piston 4 from the buffered support (support 5), the elastic body b is compressed depending on the magnitude of the force, and the piston 4 is compressed within the internal cylinder 3 according to the bulk modulus of the elastic body. The reciprocating movement absorbs and buffers the energy of the external force.

The internal pressure of the elastic body b sealed in the inner cylinder 3 is proportional to the amount of displacement of the piston 4 as described above,
In the device shown in Figure), the bulk modulus is K, and the initial internal pressure is
Assuming P ₁ , P ₁ = ΔV _p /VK Here, ΔV _p : Initial compression amount of the elastic body V: Volume of the inner cylinder Also, the amount of volume change due to the displacement of the piston 4 ΔV
is, ΔV=1/4πd ² .X Here, π: Pi d: Diameter of piston 4 X: Amount of change in piston 4 The internal pressure P ₂ of the inner cylinder 3 when the volume change amount ΔV occurs is: P ₂ = ΔV + ΔV _p /VK In the conventional device, the change in internal pressure depends only on the bulk modulus of elasticity. For example, if you want to change the performance, you can change the elastic body itself to one with different physical properties, Although it is necessary to change the capacity of the cylinder, the present invention is characterized in that the internal pressure of the inner cylinder 3 can be freely changed and adjusted in response to the displacement of the piston 4.

In the present invention, the amount by which the piston 4 compresses the elastic body b is ΔV=A _n・X _n −A _s・X _s , where ΔV: Amount of compression _{A n :} Pressure-receiving area of the piston 4 Displacement A _s : Pressure receiving area of the sub piston 10 X _s : Displacement of the sub piston 10, and the displacement X _s of the sub piston 10 is
1, X _s = (P _s・A _s −F _p )/k where, P _s : Internal pressure of the inner cylinder 3 F _p : Initial load of the adjustment spring 11 k : Spring constant of the adjustment spring 11 It can be expressed by the formula.

In other words, the internal pressure of the inner cylinder 3 is the piston 4
The amount of compression is proportional to the amount of compression of the adjustment spring 11.
Due to this performance, the secondary piston 10 can be freely adjusted by being inserted into the piston 4. That is,
The internal pressure of the inner cylinder 3 can be adjusted by changing the performance of the adjustment spring 11 (see Fig. 3), and by incorporating adjustment springs 11 with different performances, various required specifications of the support to be buffered, that is, the mother machine can be adjusted. It can be made into a buffer support function suitable for

In addition, expansion of the elastic body b due to environmental temperature changes,
Shrinkage can be absorbed automatically. That is, when the elastic body b expands or contracts and the internal pressure of the inner cylinder 3 changes, the adjustment spring 11 contracts accordingly and the sub-piston 10 is automatically inserted into the piston 4 to absorb the amount of expansion or contraction. ,to correct.

Inner cylinder 3 caused by environmental temperature changes
The change in the internal pressure is as shown in FIG. 4, and the effect of automatic adjustment of the internal pressure in the present invention is remarkable compared to the conventional example.

(Effect of the invention) As mentioned above, in the present invention, a sub-piston is provided that is movably fitted on the elastic body side of the piston of the inner cylinder and protruded by an adjustment spring. By changing the amount of protrusion of the piston, the internal pressure of the elastic body can be adjusted by changing it, and the expansion and contraction of the elastic body that occurs with environmental temperature changes, i.e., increases and decreases in the internal pressure, are automatically controlled by the movement of the secondary piston. Therefore, it is absorbed and adjusted, damage to the device is prevented, and durability, reliability, and shock absorbing performance are significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a shock absorbing support device showing an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view showing a conventional example, and Fig. 3 is a diagram of adjusting the internal pressure of the inner cylinder by the adjustment spring in the present invention. , FIG. 4 is a comparison diagram of the internal pressure of the inner cylinder between the conventional example and the present invention. 1...Frame (truck frame), 2...Outer cylinder, 3...Inner cylinder, 4...Piston, 1
0... Subpiston, 11... Adjustment spring, a... Incompressible fluid, b... Elastic body.

Claims (1)

[Scope of utility model registration request] An inner cylinder is fitted into an outer cylinder on the frame side and is slid by an incompressible fluid, and the inner cylinder is supported and covered by a fluid elastic body disposed in the inner cylinder and sealed in the inner cylinder. A shock absorbing support device comprising: a piston of the inner cylinder that resiliently supports a shock absorbing support; and a sub-piston that is movably fitted on the elastic body side of the piston and projected by an adjustment spring.