KR910000777B1 - Shock absorber - Google Patents

Abstract

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Description

Shock Absorber

1 is a cross-sectional view of a conical bellows buffer of the present invention.

2 is a cross-sectional view of another embodiment of a bellows buffer.

3 is an internal sectional view of the bellows casing.

4 is a cross-sectional view of another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

2,3: end plate 4: casing

6: hole 7: side with large diameter

8: side with small diameter 9: circumferential edge

11: Lip 12: End wall

15 ring 16 compression spring

17,18: inner and outer crest part 23,24: sleeve

25: axial groove 26: projection

FIELD OF THE INVENTION The present invention relates to shock absorbers, and more particularly to shock absorbers used to dampen the compressive forces present between moving mechanical elements.

For example, such a shock absorber is in the form of a shock absorber made of an elastic material. Such shock absorbers are installed at predetermined positions between the moving mechanical elements to cushion each other's movement. As the elements move toward each other, they impact the shock absorber and the impact energy is absorbed by the elastic deformation.

While such a buffer is very simple in structure, on the other hand, the buffer capacity of the device has the drawback that it becomes constant depending on the choice of buffer material. In addition, after several cycles of deformation, the shock absorber will exhibit less fatigue. Also known are friction type shock absorbers consisting of two lever arms pivoted together. Since the shock is absorbed by friction, each lever arm is installed so that the shock is damped by one of the two relatively moving mechanical elements. Thus, these lever arms are relatively pivoted within the pivot shaft connection such that the kinetic energy of the mechanical element is attenuated by friction in the pivot shaft connection and converted back into heat.

With this type of friction type shock absorber, depending on the operability of the pivotal shaft connection, a considerable buffering effect can be obtained even if there is a degree of difference. This buffering action can be changed in each case by providing an appropriate fixing plate on the pivot shaft connecting portion. However, a drawback of such a friction buffer is that the structure is relatively complicated, which leads to a high manufacturing cost and a large overall size.

In addition, hydraulic shock absorbers are known in the field of vehicle construction. In this case, the vibration of the spring generated when driving the uneven road surface is changed into thermal energy by the friction of the liquid. The fluid oil is thereby forced by the piston through the valve system under spring force. Such shock absorbers initially had a shock-absorbing effect that could be altered in structure, to some extent by adjustment of the valve spring, and / or by adjustment of the cross section of the passage through the piston, but such hydraulic shock absorbers are also quite complex in structure. In order to ensure that the piston and the cylinder constituting the hydraulic system are in tight sealing contact with each other, a very precise manufacturing tolerance is required, thereby increasing the manufacturing cost of the natural shock absorber. In addition, due to the exchange of fluid between the cylinder of the hydraulic shock absorber and the fluid reservoir during operation, the size of the shock absorber could not be reduced and the height could not be reduced. Even at a very small size, the manufacturing cost was not reasonable in terms of usefulness.

It is an object of the present invention to provide a shock absorber having a structure that can compensate for the shortcomings of the existing shock absorber and can control the buffering performance in a simple manner.

Another object of the present invention is to provide a buffer having a structure that can be manufactured in a variety of different shapes and sizes at low cost.

In order to achieve this object, the shock absorber of the present invention is a shock absorber comprising a bellows-type casing and a housing having rigid both end plates provided on both sides of the casing, wherein the bellows-type casing is conical and both end plates are bellows. It is movable closer to and away from each other in the axial direction of the mold casing, and a hole for communicating with the casing is provided in one end plate, and the pleats of the bellows-type casing are from the one with the large diameter to the one with the small diameter. With the size or wavelength gradually decreasing gradually, the radius of curvature of the crease decreases at a small rate on the side with the large diameter of the casing, and the stress of the crease is

(Where M is the bending moment, W is the resistance moment), and has an inner and outer crest portion of elliptic curvature, the major axis of the ellipse is the same length, and the length of the minor axis is a small diameter. It is getting smaller and smaller toward having, characterized in that the outer ring of the bellows-type casing is provided with a spring-loaded ring between the corrugated portion. According to such a shock absorber of the present invention, a hole passing through the inside of the casing is formed in one end plate, and an adjustable choke valve can be attached to this hole.

Due to such a configuration, a shock absorber having a configuration capable of fully utilizing components developed in the technical field of aerodynamics can be provided. Bellows in various shapes and sizes are available commercially. In addition, adjustable choke valves are well known in the art so that no detailed explanation is required.

Therefore, the shock absorber of the present invention can be produced very simply by using an improved component whose function is demonstrated. Therefore, this shock absorber has low manufacturing cost and high reliability. As a medium for shock shock, the sealed air in a casing is used. Since the air in the casing is forced through the choke valve, the mechanical element to be cushioned causes compression of the bellows-type casing part on the end plate. Therefore, the effect of absorbing the shock of the shock absorber according to the present invention depends on the flow resistance imparted to the air by the choke valve. Since this flow resistance can be adjusted widely by a simple form, according to this invention, the buffer which has a variable buffer characteristic is provided.

Such a shock absorber, on the other hand, is made of an elastic inner material and can be manufactured as a compact device which does not occupy space as a substitute for a conventional shock absorber. Useful examples of such shock absorbers include those used in small manual operated devices such as office machines. In this case, by using a shock absorber having an adjustable shock absorbing characteristic, it is possible to perform shock shock in response to the weight of the office machinery and vibration generated. As a result, the machine is handled more importantly than before, and at the same time, its operability is more comfortable. It can also be used in applications where the amount of energy to be absorbed is not very large.

In addition, since the bellows-type casing is hollow conical, an excellent cushioning effect can be obtained even if the height of the shock absorber is low. That is, due to the fact that the degree of compression of the bellows depends on the geometrically folded shape. If the bellows has a cylindrical shape, the amount of compression is relatively limited because the folded portions are in close contact with each other while the bellows is cylindrical, but in the case of a conical shape, the folded state partially overlaps up and down, that is, the folded state is folded inwardly. Because of the condition, the amount of air displacement for a given bellows height is much larger than for a pure cylinder. This is particularly good in that it is a configuration that does not take up space.

Since the contour shape of such a shock absorber is the same as that of a conventional rubber shock absorber, it can be substituted without requiring any modification in many fields. In the shock absorber according to the present invention, a restoring force is required to restore the casing compressed after the impact to the initial state after the pressure acting on the end plate is controlled.

According to one basic technical idea of the present invention, such restoring force is generated by the internal elasticity of the bellows-type material. This requires that the bellows-type casing be constructed of high quality material with spring elasticity.

In addition, the present invention is particularly advantageous in terms of production cost. That is, since it is not only able to save material but also to apply plastics, the spring characteristic of a bellows casing is made by the spring member mounted in this casing, or the compression spring arrange | positioned between end plates. , Complementary or counterparted. By using such a compression spring, the compression spring can be installed inside the shock absorber casing in a configuration that does not take up space in particular. Moreover, the guide apparatus for the cover plate which moves relatively in a shock absorber is provided.

This guide device prevents the relative rotational movement of the cover plate and at the same time surrounds the bellows casing of the shock absorber as a protective sleeve. According to such a configuration, the sleeve acts as a protective plate, which makes the shock absorber strong, but requires more space.

In the shock absorber according to the present invention, in particular, in addition to the choke valve, the check valve may be provided in a hole through which the casing passes. Since the check valve can quickly vent the casing of the shock absorber to be expanded again after the impact, the shock absorber is in a state in which the next operation is performed very quickly. On the other hand, when the casing of the shock absorber is compressed by an external force, this check valve is closed, so that air entering the casing is discharged only through this check valve.

Therefore, the flow resistance of the air which flows out from this shock absorber is remarkably larger than the flow resistance of the incoming air. Therefore, the above-described configuration is advantageous and ultimately inevitable when a series of shocks that are continuous at a rapid cycle are to be supplemented and absorbed by the shock absorber of the present invention. In this case, the structure of the shock absorber is not complicated. This is because this check valve can be combined with a known choke valve having a check function.

According to the main technical idea of the present invention, the size and wavelength of the pleated portion of the bellows-type casing are continuously reduced from the side having the large diameter to the side having the small diameter. In addition, the curvature of the wrinkles and the radius of bending are gradually smaller from the one with the larger diameter to the one with the smaller diameter. This gradual change in the shape of the pleats is such that the stress of the pleats (formally, bending moment / resistance moment) is kept constant. The inner and outer crests of the corrugation are curved in an oval shape, and the major axes of the ellipses are all the same length, but the length of the minor axis becomes smaller and smaller toward the smaller diameter.

Such an invention relating to the geometric shape of such corrugations represents a preferred form of the invention using a casing or housing such as a conical bellows. On the other hand, according to such a structure, a bellows-type casing can be compressed more effectively, a larger buffer stroke can be made to a given bellows at the same height, and about the same stress generate | occur | produces in each wrinkle part. Therefore, problems due to premature fatigue and breakage are not caused to the bellows, thereby extending the life of the bellows.

The invention is described in detail below in conjunction with the embodiments shown in the accompanying drawings.

In the drawings, like numerals denote like parts, and as shown in FIG. 1, the shock absorber 1 is connected by a bellows-shaped casing 4 as a main part, and the rigid end plates 2 facing each other are shown. ), (3). The end plates 2, 3 together with the casing 4 form a housing, which is compressed by pushing the corrugations 5 in the axial direction, and in this operation the end plates 2, ( 3) are moved closer to each other. This compression of the housing is caused by the impact acting mainly axially on the end plates 2, 3. The generated impact energy is changed to the work required to exhaust the air inside the casing through the choke valve. The choke valve is located in a hole 6 provided in one of the end plates 2, 3 to communicate the inside of the casing with the external atmosphere.

These choke valves, not shown in the figure, are adjustable to suitably change the flow of air from the bellows, whereby the choke valves are adapted to match the shock absorber's cushioning characteristics to the required operating conditions. You can. In particular, the choke valve is screwed into the hole 6 having a female thread.

In accordance with the impact effect acting on both end plates 2 and 3, the housing of the shock absorber 1 is moved to a partially compressed position, through which the choke valve screwed into the hole 6 from the housing. Discharge it. When the force acting on the end plates 2, 3 is reduced, the housing elastically returns to its initial position, which is caused by the internal elastic force of the bellows casing 4.

2 shows a casing 4 in the form of a conical bellows in more detail. According to this shape, the casing 4 is given high radial rigidity and an effective axial guiding effect. More specifically, when the casing 4 is compressed, the corrugations 5 are located concentrically inward to allow a relatively large compression movement so that the end plates 2, 3 are moved significantly toward each other. According to this configuration, it is possible to increase the volume of air discharged from the casing while lowering the overall height of the shock absorber 1. That is, such a shock absorber 1 enables a high level of energy absorption while enabling a wide range of motion.

When the bellows-shaped casing 4 is conical in accordance with the present invention, the diameter of the end plate 3 located on the side 7 having a large diameter is protruded in the radial direction from the casing 4. It is suitable to be as large as possible, in which case the circumferential edge 9 of the end plate 3 projecting out of the casing 4 can be used to install a fixing element (not shown), whereby (1) may be fixed to the part where the device such as office equipment needs to be buffered.

At the same time, the end plate 3 has the function of a mounting plate, and generally has a hole 6 in which a choke valve is installed. On the other hand, the end plate 2 opposed thereto does not have any hole as a buffer plate for absorbing movement from the base of the device toward the moving part.

As shown in FIG. 1, the shock absorber 1 has a bellows-shaped body without end plates 2, 3, which is open at one end and closed at the other end. To distinguish this, the ends of the bellows casing 4 on the side 8 having a small diameter are shaped in the form of flat end walls 10. The end plate 2 is generally the same size as the end wall 10 and is strongly joined to the end wall by welding or adhesive. On the other hand, on the side 7 having a large diameter, the casing 4 is open toward the end plate 3. The casing 3 forms the lip 11 outwardly in contact with the end plate 3 and is hermetically joined to the end plate 3.

Such joining may be performed by bonding or welding as in the above, but it is not necessary. That is, as shown in FIG. 2, the side wall of the bellows structure can be sealed with the end wall 12 of the end plate 3.

The end wall 12 has a hole 13 connecting between the choke valve (not shown) and the space 14 inside the shock absorber.

As can be seen in FIG. 2, the hole is a means of supplementing the elastic force of the bellows casing 4 so that the recovery force does not depend only on the elastic force when the bellows is compressed.

For this purpose the casing has a ring 15 springing between the corrugations, which ring is made of steel. The casing 4 itself is made of a soft material having a high elasticity such as rubber or synthetic resin. The spring has the effect of hardening the material and enhancing the elastic resilience. The compression springs 16 support both end plates between the end plates 2, 3, and these compression springs 16 are combined with the ring spring 15, which does not use such a ring. Edo also gives greater casing resilience.

In a preferred aspect of the present invention, the compression spring 16 is located in the space 14 in the shock absorber 1. The shape of the shock absorber 1 of the present invention is shown in FIG. 2, in which case the size of each corrugation portion 5 of the bellows-shaped casing 4 is the side 7 having the large diameter of the casing 4. ) Is continuously reduced to the side 8 having a small diameter. Thus, reducing the size of the pole is achieved by reducing the radius of the pleats 5.

According to such a structure, since the crimp part 5 which receives compression is piled up by the compression of the shock absorber 1, the thickness of a casing material may be piled up and the grade which can take concentric positions of the inner surface mutually may be sufficient. In this case, the following is preferable. The grade of the crease size is the stress δ at the crease, that is, the ratio of the bending moment M of the crease material to the resistance moment W is δ = M / W = constant, Keep it constant over time. In this way, the load acting on the shock absorber 1 is evenly distributed throughout the pleats 5 of the casing 4, thereby completely eliminating fatigue of materials and extending the life of the shock absorber 1 of the present invention. .

The pleats 5 according to the embodiment of the invention shown in FIG. 2 are somewhat curved in a circular shape. However, the same stress pattern as that of this embodiment is achieved by taking the following measures even in the embodiment shown in FIG. That is, if the inner and outer crest portions 17 and 18 of the conical casing 4 are each curved in an elliptical shape, all of the elliptical main shafts 19 have the same length, while the length of the minor shaft 20 is The pleats of the casing 4 become smaller and smaller toward the side 8 having the smaller diameter. This elliptical shape in the wrinkle part 5 is shown in FIG. 3 using the broken line 21. As shown in FIG. In addition, in the first shock absorber 1 of the present invention having the shape as shown in FIG. 3, both end plates 2, 3 extend to the outer end portion extending beyond the bellows-shaped end in the radial direction. Protruding. The compression springs 16 between the circumferential edges 22, 9 of the end plates 2, 3 compress the plates spaced apart from each other as a recovery spring for the shock absorber 1. It is located outside the casing 4.

In another embodiment of the invention shown in FIG. 4, the end plates 2, 3 are guided to move the bellows-shaped casing 4 axially without being moved to the inclined position. . Particularly preferred such a guide system is when the shock absorber 1 is operated in an uncontrollable impact in all directions, in which case the guides of the end plates 2, 3 are guided to the respective end plates 2, It is possible to carry out via the sleeves 23 and 24 attached to (3) and superimposed coaxially with each other. The sleeves 23 and 24 are telescoped, i.e., in and out, in a direction close to or away from each other when the axial movement of the end plates 2, 3 occurs. By performing such telesk type guidance, it is avoided that the bellows-type casing 4 causes uncontrollable deformation when a pressure shock is applied to the shock absorber 1 in the substantially axial direction or in the non-axial direction. Moreover, in order to prevent the relative rotational movement of both end plates 2 and 3, the groove 25 of the axial direction is provided in one sleeve 24, and the other sleeve 23 suitably. The protrusion 26 formed integrally is guided in this groove 25.

The guide system shown in FIG. 4 can be considered also in the case of the conical casing 4 as in the case of the bellows-shaped casing 4 formed in a cylindrical shape.

Furthermore, each element showing different embodiments of the shock absorber 1 according to the present invention described by the drawings can be replaced with each other. That is, of course, even if each of these elements combines in the form different from what is shown, of course it falls within the scope of the present invention.

The shock valve according to the present invention is of the type generally used for the choke valve inserted into the hole 6. That is, this choke valve is an adjustable valve which can change the flow resistance of the air which is compressed from the shock absorber 1 or flows into it. Therefore, it is possible to adjust desired buffer characteristics in the shock absorber or to make the buffer characteristics suit the situation. Even when the shock to be absorbed at an extremely low frequency must be taken into consideration, the shock absorber according to the present invention does not require another valve device, and is simply possible with such a choke valve, and the air is provided through this choke valve. It flows into or out of the casing of (1).

What is required as the operating condition in the shock absorber 1 is that the time required for the shock absorber 1 to inhale air after returning the load and return to the initial position is less than the time between the continuous shock and the next shock. It is much shorter.

If these working conditions are not satisfied, in another embodiment according to the present invention, it is necessary to provide the shock absorber 1 with a check valve fixed to the hole 6 communicating with the space 14 of the casing.

In this case, in order to use the choke valve which has a check function, the hole 6 which can attach the choke valve should just be formed. In addition, it is also possible to provide a separate hole (not shown) for the check valve in one of the end plates 2, 3. The check valve must be installed in the shock absorber 1 so that the casing becomes a closed position when the casing is pressurized by an external impact and is switched to the open position when the load of the shock absorber 1 is reduced.

In this way, the air put into the space 14 of the shock absorber 1 is injected through only the choke valve at the time of the load pressure, and conversely, during the load reduction, the air is sucked in via the check valve. It becomes possible.

In addition, the check valve in this case must be designed to give inflow air with a significantly lower flow resistance than the choke valve. In this way, since the recovery time of the shock absorber 1 by this invention can be shortened, this shock absorber 1 can also absorb the shock which generate | occur | produces continuously at high frequency.

Claims (5)

In a shock absorber comprising a bellows-type casing and a housing having rigid end plates provided on both sides of the casing, the bellows-type casing is conical, and the end plates are moved closer to each other in the axial direction of the bellows-type casing. And a hole leading to the casing is provided in one end plate, and the bellows-shaped casing has a size or wavelength that gradually decreases from the side having the large diameter to the side having the small diameter. The radius of curvature of the crease is reduced at a small rate on the side with the larger diameter of the casing, and the stress of the crease is

(Where M is the bending moment, M is the resistance moment), and has an inner and outer crest portion of elliptic curvature, the major axis of the ellipse is the same length, and the length of the minor axis is a small diameter. A shock absorber, characterized in that it becomes smaller and smaller toward having, and a springing ring is provided between the corrugations outside the corrugations of the bellows-type casing. The shock absorber according to claim 1, wherein guide plates for guiding prevention of twisting are provided on end plates which are movable closer to each other in an axial direction of the bellows-type casing. The said guide means is provided so that the 1st sleeve formed in the one end plate and the 2nd sleeve formed in the other end plate are mutually adjacent to each other, and can be stretched in the axial direction, The said 1st sleeve And a groove is machined in the axial direction, and the second sleeve has a protrusion provided in the axial groove so as to be reciprocated. The shock absorber according to claim 1, wherein at least one compression spring means is provided between the both end plates to apply a spring force to the both end plates. 5. The shock absorber according to claim 4, wherein the spring means is a single compression spring located in the housing.

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