JPH08159198A - Air spring with inclined end ring - Google Patents

Abstract

PURPOSE: To freely set the suitable restoring force also when the heavy weight is supported by an air spring having the small size by providing an upward extending and inclined inner surface on an end ring for positioning and fixing the end of a flexible diaphragm to which internal pressure is applied, and supporting the diaphragm outer surface by the end ring. CONSTITUTION: When an inner cylinder 2 is deviated rightwards in the horizontal direction, the inner cylinder 2 presses a diaphragm 1 in the right direction so as to decrease the clearance between the contact part of the diaphragm 1 and the right end surface of the diaphragm, and the diaphragm right side surface is slightly deviated to the right so as to increase the contact area on the right side end ring contact part of the diaphragm. Since the diaphragm 1 is moved along the inclined inner surface 7 of an end ring 6, the increase of the height of the diaphragm can be restrained for the degree of the positional deviation of the inner cylinder 2 in comparison with the outer cylinder restricting-type air spring. As a result, even if the inner cylinder 2 is horizontally deviated by the same distance, the restoring force is also decreased since the difference between the pressurizing areas on the right and the left to the inner cylinder 2 is small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air spring incorporated in a railroad vehicle, a large automobile, an ultra-precision machine tool, and other vibration isolation devices.

[0002]

2. Description of the Related Art As is well known, there are two types of air springs, one consisting of a piston and a cylinder made of metal and the other using a rubber film reinforced with fibers. In addition, in the type using a rubber film, a non-inverted type (bellows type) in which the rubber film only expands and contracts in a bellows shape during the stroke and does not invert, and a rubber film that inverts during the stroke There is a type (diaphragm type), and a type (combined type) in which an inverted type and a non-inverted type are combined has also been developed.

The air spring has the advantages that the natural frequency can be kept substantially constant irrespective of changes in the load, the insulation of high frequency vibration is good, noise can be prevented, and greasing for the spring is unnecessary. However, since the air spring itself has no rigidity except in the vertical direction, a position restraint member is required.

For example, in the diaphragm type air spring shown in FIG. 1, a fiber-reinforced rubber diaphragm 1 is used.
However, while being fixed in position by the end ring 5 to the base surface 4, the inner cylinder 2 which is pneumatically applied to the inside and attached to the carriage or the like is supported in the vertical direction. The outer cylinder 3 is arranged so as to contact the diaphragm 1, and when the inner cylinder 2 moves in the horizontal direction, the outer cylinder 3 acts to restore the original position.

An illustration of this will be as follows. That is, as shown in FIG. 2, when the inner cylinder 2 is displaced from the right side, the membrane length from the end ring 5 to the attachment position 8 on the bottom of the inner cylinder 2 of the right side portion 1 ′ of the diaphragm is the reinforcing fiber. Does not change due to the presence of the outer cylinder 3 and the diaphragm is restricted in displacement by the outer cylinder 3, so that the contact area with the inner cylinder 2 increases corresponding to the reduction in the distance between the inner cylinder 2 and the outer cylinder 3. higher becomes as (L _2), whereas the left portion of the diaphragm 1 '' is lower so as to reduce the contact area of the inner cylinder 2 on the contrary (L _1). As a result, a height difference (ΔL ₁ ) is created on the left and right sides of the diaphragm across the inner cylinder 2,
Since the pressure receiving area of the inner cylinder 2 from the diaphragm 1 is different between the right side surface and the left side surface, the restoring force F in the left direction acts on the inner cylinder 2.

[0006]

This restoring force F is determined by the air pressure applied to the diaphragm 1 and the dimensions and positional relationship (w ₁ , w ₂ ) of the inner cylinder 2 and the outer cylinder 3, In a conventional railway vehicle that supports several tons of weight with 4 to 6 air springs with a diameter of 1 m, a relatively large dimensional difference between the outer cylinder and the inner cylinder restores the passenger car to an appropriate degree. Adjusted to gain power.

However, when trying to support a considerable weight after reducing the size of the air spring, it is difficult to increase the dimensional difference between the outer cylinder and the inner cylinder. There is a problem that the variation of the area becomes large and therefore the restoring force becomes too large.

As shown in FIG. 3, with the outer cylinder temporarily removed, the diaphragm 1 is attached to the base surface 4 by the end ring 5
If the inner cylinder 2 is fixed in position and the inner cylinder 2 is supported in the vertical direction, the diaphragm alone does not generate a restoring force in the horizontal direction. As described above, the right side portion 1 ′ of the diaphragm bends so as to get over the end ring 5 that is a fixed portion, and the height becomes low, so that the pressing area (ΔL ₂ ) occurs, and contrary to the case of the normal outer cylinder restraint type air spring, the inner cylinder 2 acts to shift further to the right, so to speak, a negative restoring force (-
F ') occurs.

Further, when the outer cylinder is constructed lower than that shown in FIG. 1 with respect to the inner cylinder, when the inner cylinder is displaced in the horizontal direction, a phenomenon occurs in which the diaphragm bends so as to ride over the outer cylinder. As with the non-outer cylinder restraint type, the required restoring force does not occur.

That is, in the structure of the conventional diaphragm type air spring, if an object of a relatively small size is to support a large weight, a considerably strong restoring force is accompanied with respect to a horizontal movement, If the restoring force is too large, the non-outer cylinder restraint type air spring, which has no restoring force and acts only in the vertical direction, has to be used only under a sufficient condition, and the practicality is greatly limited.

Therefore, in view of the problems of the diaphragm type air spring having the conventional structure as described above, the present invention can freely set an appropriate restoring force even when a large weight is supported by the air spring having a relatively small size. It is an object to provide a diaphragm type air spring that can be used.

[0012]

In order to solve the problem, in the air spring according to the present invention, the end ring for fixing the position of the end of the flexible diaphragm under internal pressure is
It has an inclined inner surface that extends upward and supports the outer surface of the diaphragm.

It is preferable that the inclined inner surface is formed in a size that covers the horizontal displacement range of the inner cylinder attached to the upper surface of the diaphragm.

Further, it is more convenient if the outer cylinder having a height at least corresponding to the height of the diaphragm is arranged on the outer peripheral side of the end ring having the inclined inner surface so as not to come into contact with the diaphragm.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on the embodiments shown in the drawings.

FIG. 5 shows an embodiment of the present invention. The substantially cylindrical rubber diaphragm 1 is reinforced by braiding fibers in an oblique direction. As a result of the fiber reinforcement, the diaphragm 1 is restricted in stretchability, while maintaining flexibility to the extent that reversal is not impaired. The diaphragm itself having such a configuration is already known. This diaphragm 1
The end portion of is fixed to the base surface 4 by an end ring 6, and has a predetermined air pressure (for example, 5 kgf / cm ² ) inside.
Is being applied. The diaphragm 1 has an upper flat portion on which an inner cylinder 2 is attached and supported.

The end ring 6 has an inner surface 7 inclined with respect to the base surface 4 at an inclination angle β. The inclination angle β is determined so that the restoring force that is affected by the diaphragm size and the load weight is moderate. When selecting a weaker restoring force, decrease the inclination angle β and increase the restoring force. The tilt angle β is increased for the force. The inclined inner surface 7 is the inner cylinder 2
Has a length such that the diaphragm 1 does not bend over the end ring 6 even when it is displaced to the maximum in the horizontal direction.

In the air spring having such a structure, for example, when the inner cylinder 2 is displaced to the right in the horizontal direction in the drawing, the inner cylinder 2 is provided between the contact portion with the diaphragm 1 and the right end surface of the diaphragm. The diaphragm 1 is pushed to the right to narrow it, with the right side of the diaphragm being slightly offset to the right to increase the contact area of the right end ring contact portion of the diaphragm. Since the diaphragm 1 moves along the inclined inner surface 7 of the end ring 6, the increase in the diaphragm height is suppressed for the degree of positional displacement of the inner cylinder 2 compared to the case of the outer cylinder constrained air spring, and the same. For that reason, the reduction in height of the left diaphragm portion is also reduced. As a result, compared to the case of the outer cylinder restraint type air spring, even if the inner cylinder 2 is horizontally displaced by the same distance, the left-right difference in the pressing area of the diaphragm 1 to the inner cylinder 2 is small. The generated restoring force is also small.

FIG. 6 shows another embodiment. Basically, a fiber-reinforced substantially cylindrical rubber diaphragm 1 having a lot of common configurations to the embodiment shown in FIG. 5 is fixed in position by an end ring 6 having an inner surface inclined to a base surface 4. In addition, a predetermined air pressure is applied inside. An inner cylinder 2 is attached to the upper flat portion of the diaphragm and is supported by the diaphragm 1. In this embodiment, an outer cylinder 3 is further arranged on the outer circumference of the diaphragm 1. Unlike the case of the conventional outer cylinder restraint type air spring, the outer cylinder 3 is positioned so as not to come into contact with the diaphragm 1 in a state where the inner cylinder 2 is in the initial position in which the inner cylinder 2 is not displaced in the horizontal direction. As a result, when the inner cylinder 2 is slightly displaced, a weak restoring force of the inclined end ring 6 acts on the inner cylinder 2, and the displacement is increased so that the diaphragm 1 comes into contact with the outer cylinder 3. Similar to the outer cylinder constrained type, the strong restoring force of the outer cylinder 3 acts on the inner cylinder 2.

With this configuration, a weak restoring force due to the inclined end ring acts on the lateral deviation in the normal range, and a strong restoring force acts as an emergency when an abnormally large lateral deviation occurs. Can be used properly. For example, if the air spring of the present embodiment is used for a railroad vehicle, a good riding comfort due to a weak lateral guidance force is obtained in a normal driving state with a small lateral displacement, and a safety due to a strong lateral guiding force is obtained in an abnormal driving state with a large lateral displacement. Can be secured.

The inner cylinder 2 having a diameter of 140 mm is supported by the diaphragm 1 to which an inner pressure of 5 kgf / cm ² is applied, the inclination angle of the inclined end ring 6 is 30 °, and the distance between the outer cylinder 2 and the diaphragm 1 is 5 mm. Regarding the relationship between the displacement and the restoring force load when the tube diameter is 210 mm and the outer tube length is 70 mm, the same size is used for the restoring force only by the inclined end ring without the outer tube and the inner tube has the initial position. FIG. 7 shows a comparison with a conventional outer cylinder constrained type in which the diaphragm is in contact with the outer cylinder from the time when the above is present. In the configuration with only the inclined end ring, the restoring force is gently generated in the entire range of the displacement, whereas in the combination type configuration, the restoring force rapidly increases when the displacement exceeds 5 mm where the diaphragm contacts the outer cylinder. . It will be understood that in the conventional type, the restoring force rapidly increases from the stage of slight displacement.

[0022]

According to the first aspect of the present invention, the end ring for fixing the position of the end of the flexible diaphragm under internal pressure has the inclined inner surface expanding upward and supports the outer surface of the diaphragm. Since it is configured, it is possible to freely set an appropriate restoring force even when supporting a large weight with an air spring having a relatively small size.

According to the second aspect of the present invention, since the inclined inner surface is formed to have a size that covers the horizontal displacement range of the inner cylinder attached to the upper surface of the diaphragm, the inner cylinder is horizontally moved. Even in the case of maximum displacement, the effect according to claim 1 is ensured.

According to the invention described in claim 3, the outer cylinder having a height at least corresponding to the height of the diaphragm is
Since it is located on the outer peripheral side of the end ring with an inclined inner surface so as not to contact the diaphragm, a weak restoring force can be obtained in the range where the lateral displacement of the inner cylinder is small when supporting a large weight with a relatively small size air spring. It is possible to generate a strong restoring force in a large range in which the lateral displacement exceeds a predetermined range.By adjusting the inclination of the inner surface of the end ring and the distance between the outer cylinder and the diaphragm, the restoring force can be changed appropriately. It becomes possible to have.

[Brief description of drawings]

FIG. 1 is a schematic view showing a conventionally known outer cylinder restraint type diaphragm air spring.

FIG. 2 is a schematic diagram illustrating generation of a restoring force when the inner cylinder is displaced in the air spring of FIG.

FIG. 3 is a schematic diagram showing a diaphragm air spring in the absence of an outer cylinder.

FIG. 4 is a schematic diagram showing horizontal movement when the inner cylinder is displaced in the air spring of FIG.

FIG. 5 is a schematic view showing an embodiment of the present invention.

FIG. 6 is a schematic view showing another embodiment of the present invention.

FIG. 7 is a graph showing the relationship between inner cylinder displacement and restoring force for various diaphragms.

[Explanation of symbols]

 1 Diaphragm 2 Inner cylinder 4 Base surface 6 End ring 7 Inclined inner surface

Claims (3)

[Claims] 1. An air spring comprising an internal pressure-applied flexible diaphragm, an inner cylinder attached to the upper surface of the diaphragm, and an end ring for fixing the end portion of the diaphragm, wherein the end ring expands upward. An air spring having an inclined inner surface and supporting an outer surface of the diaphragm. 2. The air spring according to claim 1, wherein the inclined inner surface has a size that covers a horizontal displacement range of the inner cylinder. 3. The outer cylinder having a height at least corresponding to the height of the diaphragm is arranged at a position on the outer peripheral side of the end ring having an inclined inner surface so as not to contact the diaphragm. 1. The air spring according to 1.