JPH04210137A - Pneumatic spring - Google Patents

Abstract

PURPOSE:To provide a pneumatic spring with large strokes in elongation and contraction without designing it with a large size by putting two sleeve structures in mutual communication, and giving one sleeve structure a greater effective dia. than the other sleeve structure. CONSTITUTION:Two sleeve structures 1, 2 are coupled with each other up and down and put in mutual communication, and the effective dia. D0 of one sleeve structure 1 is made greater than that D1 of the other sleeve structure 2. This permits the resultant pneumatic spring to exert excellent flexibility for displacement in any direction vertical and horizontal and provides the pneumatic spring with large strokes in elongation and contraction without designing it with a large size. Further, the decrease in the effective dia. is suppressed in favorable manner, and the requisite pressure for elongation can be made small sufficiently.

Description

[Detailed description of the invention]

[00011

[Industrial Application Field] This invention can be applied to railway vehicles and other vehicles that require height adjustment, and can be applied to railway vehicles and other vehicles that require height adjustment.
This invention relates to an upper and lower two-stage air spring that can provide a large amount of lift. [0002] [0002] In recent years, due to mutual boarding of cars of different railway companies, etc., it has often become necessary to adjust the height of the car in order to match the height of the car with the height of the platform. In response to such demands, it has been proposed to expand and contract an existing air spring used as a vehicle suspension device or as a part thereof by controlling the pressure supplied thereto. [0003]

[Problems to be Solved by the Invention] By the way, in the case where the air spring that is expanded and deformed as required is of a bellows type as shown in FIG.
Therefore, in order to ensure a large expansion and contraction stroke, it is necessary to increase the radius of curvature r of the peak of the sleeve S, and by extension, the outer diameter of the peak, which makes it possible to avoid increasing the size of the air spring. Moreover, the effective diameter Oo Oo of the sleeve S when it is extended as shown by the imaginary line in the figure is
Since the effective diameter O-O is significantly reduced compared to the effective diameter O-O before expansion, there is a problem that the pressure required for expansion of the air spring becomes high. If it is a bellows type, the effective diameter will be greatly reduced by the extension stroke, so the pressure required for extension will be high, and in addition, the radius of curvature R of the sleeve S will be Because of the increase in size, there was a problem in that it was necessary to increase the pressure resistance compared to one with a smaller radius of curvature for the same internal pressure. Furthermore, in the case of a diaphragm type air spring as shown in Fig. 6, although it has the advantage of a small reduction in effective diameter during elongation deformation, the spring characteristics during normal use are particularly poor in the horizontal direction. There was an inconvenience that the material was considerably hard against displacement. This invention advantageously solves the problems of the prior art, and not only can exhibit excellent flexibility against displacement in both the vertical and horizontal directions, but also overcomes the need for larger air springs. It is possible to ensure a large extension and retraction stroke without any problems, and the amount of reduction in the effective diameter can be advantageously reduced so that the required pressure for its extension is sufficiently small, thus reducing the compressive strength of the sleeve. The present invention provides an air spring that hardly requires an increase in . [0004]

[Means for Solving the Problems] The present invention is an air spring formed by vertically interconnecting two sleeve structures, in which the effective diameter of one sleeve structure is is larger than that of the other sleeve structure. [0005]

[Function] According to this air splash, for example, during normal running of the vehicle, the sleeve structure with a large effective diameter provides the required spring characteristics and damping characteristics for displacement in the vertical and horizontal directions, and at this time, The other sleeve structure, which has a smaller effective diameter, exhibits little or no spring function. Here, when increasing the height of the vehicle, pressurized air is supplied into the air spring. When pressurized air is supplied, initially only the sleeve structure with a large effective diameter undergoes elongation deformation as its effective diameter gradually decreases, and its effective diameter becomes equal to that of the sleeve structure with a small effective diameter. After that, only the sleeve structure on the small diameter side, where the effective diameter hardly decreases, undergoes large elongation and deformation, so that the vehicle rises to the required height. On the other hand, if the height of the vehicle is to be returned to its original height, air is evacuated from the air spring, resulting in a deformation in the opposite order to that described above. [0006] Thus, in this air spring, under the action of the sleeve structure having a large effective diameter, it is possible to exhibit the desired soft spring characteristics against displacement in the vertical direction and the horizontal direction. By appropriately selecting the effective diameters of both sleeve structures and the difference between the effective diameters, the air spring can be expanded and deformed without increasing the size of the air spring and without significantly increasing the internal pressure of the air spring. Due to the fact that the amount can be made sufficiently large and the pressure required for elongation is small, an increase in the compressive strength of the sleeve, in particular of a sleeve structure with a large effective diameter, can be made almost unnecessary. [0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, in which 1 indicates a lower sleeve structure with a large effective diameter, in this example, and 2 indicates an upper sleeve structure with a small effective diameter. These sleeve structures 1 and 2 are shown respectively.
They are firmly interconnected via the spacer 3 and communicated with each other via the communication passage. Here, the lower sleeve structure 1 is formed by airtightly connecting the upper and lower end portions of the sleeve 4, which is mainly made of rubber or other elastic material, to the upper surface plate 5 and the lower surface plate 6, respectively. It has substantially the same shape and structure as the special diaphragm air spring shown in FIG. 5, and has a required effective diameter Do larger than the upper sleeve structure 2. [0008] The upper sleeve structure 2 also includes a sleeve 7 mainly made of rubber or other elastic material.
are also airtightly connected to each of the upper plate 8 and the lower plate 9, and the sleeve structure 2 is here integrally formed with the lower plate 9,
By sandwiching the sleeve 7 between the inner cylinder 10 fixed to the lower sleeve structure 1 and the outer cylinder 11 integrally formed with the upper surface plate 8, it is almost the same as the diaphragm type air splash shown in FIG. and has a required effective diameter D1 smaller than the effective diameter Do of the lower sleeve structure 1.
has. Note that, when the air spring is in its normal position as shown in the figure, this upper sleeve structure 2 is attached to the upper and lower face plates 8.
, 9 are brought into contact with each other in the vertical direction to restrain their vertical spring action, and at the same time, by bringing the contact portions of the upper and lower face plates 7.8 into contact with each other,
Its horizontal splash action is also restrained. Here, the inner and outer portions 12a in the radial direction of the air chamber 12 defined by the sleeve 7 and the upper and lower face plates 8 and 9
, 12b is provided at the mutual contact portion of the face plates 8 and 9,
Of course, they are communicated with each other by a communication passage (not shown), and the air chamber 12 communicates with an air chamber 13 similarly divided therein in the lower sleeve structure 1. [o o 09] In the air spring configured as described above, the lower sleeve structure 1 is connected to the hollow laminated elastic body 14.
It is used by connecting it to an auxiliary tank (not shown) via the lower sleeve structure 1, and its displacement in the vertical and horizontal directions is handled by the lower sleeve structure 1, as described above.
only act to provide the required spring and damping characteristics. Incidentally, the vehicle body (not shown) is supported on the top plate 8 by a predetermined appropriate method, and it goes without saying that a truck (not shown) is also connected to the lower side of the laminated elastic body 14. In order to raise the vehicle height of a vehicle to which this air spring is applied, for example, by supplying pressurized air from the auxiliary tank side into the air spring, as mentioned above, first, the lower By elongating and deforming only the sleeve structure 1, the effective diameter Do of the sleeve structure 1 becomes larger than that of the upper sleeve structure 2.
After the effective diameter DI becomes equal to the effective diameter DI, only the upper sleeve structure 2 is expanded and deformed until the vehicle height reaches a predetermined height. Incidentally, the mounting of the sleeve 7 thereon is based on the structure of the upper sleeve structure 2, and the effective diameter hardly changes even if it is expanded and deformed. The same applies if it is omitted. [00101 Here, when the air spring is extended and deformed, first the lower sleeve structure 1 having a larger effective diameter is
The reason why only the lower sleeve structure 1 expands is that while the internal pressures of both sleeve structures 1 and 2 are the same, their effective diameter is smaller than that of the lower sleeve structure 1.
is larger than that of the upper sleeve structure 2, so that the sleeve 4 of the lower sleeve structure 1 has the upper surface plate 5 and the spacer 3 that connect this sleeve 4 and the sleeve 7 of the upper sleeve structure 2. and the upward force exerted on the lower surface plate 9 is superior to the downward force exerted on these members by the sleeve 7 of the upper sleeve structure 2, and therefore, the state of contact between the upper surface plate 8 and the lower surface plate 9 is maintained. It is from. This-
On the other hand, the reason why only the upper sleeve structure 2 expands after the effective diameter Do of the sleeve structure 1 becomes equal to the effective diameter Dl of the upper sleeve structure 2 is because the contact state between the upper surface plate 8 and the lower surface plate 9 is When the upper sleeve structure 2 is released and can function as a spring, both sleeve structures 1 and 2 have no choice but to expand while maintaining the same effective diameter due to force balance. This is because no elongation of the lower sleeve structure 2 that would result in a change is possible. Thus, according to this air spring, the lower sleeve structure 1
Under the action of the air spring, it is possible to provide the spring characteristics as required, and it is possible to elongate and deform the air spring over a sufficient length based on the supply of pressurized air at a relatively low pressure without increasing the size of the air spring. Therefore, it becomes almost unnecessary to increase the pressure resistance of the sleeve 4 of the lower sleeve structure 1 having a large effective diameter. [00111By the way, in the illustrated device, if we assume that the effective diameter Do of the lower sleeve structure 1 is 450 mm and the effective diameter D+ of the upper sleeve structure 2 is 400 mm, and that an 8t vehicle is lifted by 300nu, the lower sleeve structure When the sleeve structure 1 is extended by 80 mm, its effective diameter Do becomes 400 mm, and after that, the effective diameter DI of the upper sleeve structure 2 hardly changes.22
0mm, and as a result, the amount of extension of the entire air spring is
The required lifting amount is 300 mm, and the air spring internal pressure at this time is such that the effective diameters of both sleeve structures 1 and 2 are both 40 mm.
0mm, and their effective pressure receiving area is 1256cm
Since it is 2, 8000/1256=6. 37 (kg/cm2), whereas the structure similar to that of the lower sleeve structure 1,
To stack independent air springs in two tiers to provide a lift of 300mm, each air spring must be stacked 150mm.
At this time, the effective pressure-receiving area of the air spring is 800C12, so the air spring internal pressure is 8000/1256=10 (kg/cm2),
The internal pressure is much higher than the required internal pressure of the air spring according to the present invention. By the way, in any of these cases, in the standard state, the charge of 8t is supported by the sleeve structure 1 or the air spring, which has an effective diameter of 450M, or in other words, an effective pressure receiving area of 1590cm2, so the air at that time The internal pressure of the spring is 8000/1256=5.03 (kg/cm2). [0012] FIG. 2 is a longitudinal cross-sectional view showing another embodiment of the present invention, in which an air spring is constituted by two sleeves 21, and the effective diameter D of the lower sleeve structure 22 is
2 is made smaller than the effective diameter D3 of the sleeve structure 23 on the L side. Here, each end portion of the sleeve 21 is connected to upper and lower face plates 2 disposed at a required interval.
4.25, respectively, and the bottom plate 25
A sleeve portion is provided between an inner cylinder 26 that is formed integrally with the inner cylinder 26 and extends downward, and an outer cylinder 27 that is formed separately from the inner cylinder 26 and can come into contact with and separate from it, and that extends upward. By sandwiching the lower sleeve structure 22 with a small effective diameter D2, the outer cylinder 27 of the lower sleeve structure 22 is constructed.
A tapered portion 28 whose diameter gradually becomes smaller toward the top forms a constricted portion in the sleeve 21, and a portion above the constricted portion forms an upper sleeve structure 23 having a larger effective diameter D3. In the air spring of this example as well, the original function of the air spring is provided by the upper sleeve structure 23 having a large effective diameter, as in the above-mentioned air spring, and when the air spring is elongated, the upper sleeve structure 23 Until the effective diameter D3 of the sleeve structure 23 becomes equal to that of the lower sleeve structure 22 having a smaller effective diameter, only the upper sleeve structure 23 is expanded, and after that, only the lower sleeve structure 22 is expanded. Therefore, this air spring can also provide the same effect as shown in FIG. 1. [0013] FIG. 3 is a longitudinal sectional view showing still another embodiment of the present invention, which approximately corresponds to an inverted air spring shown in FIG.
and is substantially similar to that shown in FIG. [0014]

[Effects of the Invention] Thus, according to the present invention, not only can the desired spring characteristics be obtained, but also the air spring can be used at low supply pressures without increasing the size of the air spring or increasing the pressure resistance of the sleeve. Therefore, a sufficiently large amount of elongation can be secured.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing still another embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a route showing a conventional example.

FIG. 5 is a longitudinal cross-sectional view of a route showing another conventional example.

FIG. 6 is a longitudinal sectional view of a route showing still another conventional example.

[Explanation of symbols]

1.22 Lower sleeve structure 2.23 Upper sleeve structure 3 Spacer 4, 7.21 Sleeve 5.8.24 Top plate 6.9.25 Bottom plate 10, 26 Inner cylinder 11.27 Outer cylinder 12.13 Air chamber

Claims (1)

[Claims] [Claim 1] An air spring formed by vertically interconnecting two sleeve structures, wherein both sleeve structures communicate with each other, and the effective diameter of one sleeve structure is set to that of the other sleeve structure. Air spring made larger.