Air spring with transverse and vertical stiffness ratio larger than 1

Abstract

The invention discloses an air spring with the transverse and vertical rigidity ratio larger than 1, which comprises a bag skin, an upper cover and a piston which form a closed cavity, the closed cavity is filled with gas with set pressure so as to enable the bag skin to expand, the periphery of the upper cover is connected with an outer sleeve part, and the outer sleeve part extends vertically and wraps the outer side wall part of the bag skin. The air spring is provided with the outer sleeve part, the air spring generates transverse rigidity through interaction force between the outer sleeve part and the expansion bag skin, the transverse rigidity of the air spring can be adjusted by adjusting the vertical height of the outer sleeve part, and then the transverse and vertical rigidity ratio of the air spring is larger than 1; the transverse stroke and the vertical stroke of the air spring are both large, rigidity sudden change does not exist in the operation process, and the overall stability is good. The air spring is simple in overall structure and low in production cost, the fatigue life of the bag skin of the air spring can be prolonged by optimizing the shape of the outer sleeve piece, and the reliability is improved.

Description

Technical Field

[0001] The present invention relates to the field of air springs, and particularly to an air spring with a transverse-to-vertical stiffness ratio greater than 1. Background Art

[0002] An air spring assembly generally consists of components such as a bladder, an upper cover, and a lower cover (piston). Among them, the air spring bladder is sealed with the upper cover and the lower cover through interference fit or by crimping, etc., to form an air spring assembly with a sealed chamber. When compressed gas, which can be air or nitrogen, etc., is filled into the sealed chamber under a constrained state, the air spring assembly has an elastic function under the action of internal pressure. It has a vertical stiffness in the vertical direction, and the vertical stiffness generally has non-linear characteristics. The air spring assembly also has a lateral stiffness under the action of internal pressure, but the lateral stiffness value is generally small. Especially for a diaphragm air spring, the lateral stiffness value is even negative, which will affect the application range of the air spring.

[0003] After retrieval, for the invention patent with the patent number "201910769283.9" and the name "Nonlinear air spring", this patent includes an upper support, an airbag, an auxiliary spring and a bottom plate, which can achieve the nonlinear characteristics of the horizontal stiffness and ensure the lateral stability and comfort of the vehicle. However, there is a stiffness mutation during the operation of this air spring, and the running smoothness is poor. Another example is the invention patent with the patent number "201911095409.5" and the name "A nonlinear air spring and its lateral stiffness design method", which realizes the three-stage lateral nonlinear stiffness and can better adapt to various line conditions to ensure the safety requirements of the vehicle. However, this air spring also has problems such as lateral stiffness mutation and unstable operation, and the lateral stiffness is not adjustable. Another example is the invention patent with the patent number "201810761812.6" and the name "An air spring providing lateral stiffness", which can provide the lateral stiffness of the air spring by setting a steel belt in the airbag of the air spring; a wear plate is added to the stop seat, and the wear plate can support the vehicle body and reduce the wear caused by the lateral position of the air spring, improving the service durability of the air spring. However, in this solution, the method of realizing the lateral stiffness is to add a wire ring inside the airbag, and the increased lateral stiffness is very limited. Another example is the invention patent with the patent number "202011153571.0" and the name "A method for improving the lateral stability of an air spring and an air spring", which increases the lateral force between the upper support and the base by setting a friction component between the upper support and the base of the air spring, so as to reduce the lateral load of the air spring, avoid or reduce the mutation of the lateral stiffness and the lateral impact phenomenon, improve the lateral stability of the air spring, and at the same time can also realize the adjustable lateral force of the air spring to meet the objective requirements of the lateral stability of the vehicle vibration isolation system and ensure the running smoothness and passenger comfort of the vehicle under various complex working conditions. Although this solution can achieve the lateral stability of the air spring through the friction pair structure, it has high requirements for the friction pair material and poor durability. Another example is the invention patent with the patent number "202111247605.7" and the name "A method for improving the lateral stability of an air spring", which increases the lateral reaction force of the air spring through a positioning bushing, thereby increasing the lateral vertical stiffness ratio of the air spring and improving the lateral stability of the air spring. However, in the working state with a large lateral offset, material deformation will form a pile-up, the lateral stiffness will increase sharply, and the lateral fatigue life of the elastomer is limited. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides an air spring with a lateral vertical stiffness ratio greater than 1, which improves the lateral stiffness of the air spring while maintaining the fatigue life of the air spring envelope to meet the requirements, and improves the stability and reliability of the product.

[0005] The present invention realizes the above object through the following technical solutions:

[0006] An air spring with a transverse-vertical stiffness ratio greater than 1, comprising a bladder, an upper cover and a piston that form a sealed chamber. The sealed chamber is filled with gas at a set pressure to expand the bladder. An outer sleeve is connected to the outer periphery of the upper cover. The outer sleeve extends vertically and wraps part of the outer sidewall of the bladder, so that the interaction force between the outer sleeve and the expanded bladder generates a transverse stiffness for the air spring.

[0007] A further improvement lies in that a limiting ring is provided on the bottom surface of the upper cover. The top end of the bladder tightly adheres to the bottom surface of the upper cover horizontally and retracts inward until it abuts against the outer wall of the limiting ring.

[0008] A further improvement lies in that a buffer block is provided at the center position of the bottom surface of the upper cover.

[0009] A further improvement lies in that the set pressure is 0.5 - 0.7 MPa.

[0010] A further improvement lies in that the outer sleeve is integrally cylindrical, and the top of the outer sleeve is welded to the outer periphery of the upper cover as a whole. The bottom end of the outer sleeve forms a smooth arc-shaped warp.

[0011] A further improvement lies in that the vertical height of the outer sleeve is 60 - 150 mm.

[0012] A further improvement lies in that the vertical height of the outer sleeve is adjustable, and: when the vertical height of the outer sleeve increases, the transverse stiffness of the air spring increases, and the transverse-vertical stiffness ratio increases; when the vertical height of the outer sleeve decreases, the transverse stiffness of the air spring decreases, and the transverse-vertical stiffness ratio decreases.

[0013] A further improvement lies in that the outer sleeve is composed of a first cylinder and a second cylinder. The first cylinder is connected to the outer periphery of the upper cover, and the second cylinder is coaxially and movably sleeved on the first cylinder. The vertical height of the outer sleeve is adjusted by changing the overlapping degree of the second cylinder and the first cylinder.

[0014] A further improvement lies in that an adjusting member is provided on the outer peripheral wall of the first cylinder for changing the overlapping degree of the second cylinder and the first cylinder.

[0015] The beneficial effects of the present invention are as follows:

[0016] (1) The air spring of the present invention is provided with an outer sleeve, and the interaction force between it and the expanded bladder generates a transverse stiffness for the air spring. By adjusting the vertical height of the outer sleeve, the transverse stiffness of the air spring can be adjusted, so that the transverse-vertical stiffness ratio of the air spring is greater than 1;

[0017] (2) The transverse stroke and the vertical stroke of the air spring of the present invention are both large, and there is no sudden change in stiffness during operation, and the overall stability is good.

[0018] (3) The overall structure of the air spring of the present invention is simple, the production cost is low, and through the shape optimization of the outer sleeve, the fatigue life of the air spring envelope can be improved and the reliability can be increased. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the external structure of Embodiment 1 of the present invention;

[0020] Figure 2 It is a sectional view of Embodiment 1 of the present invention;

[0021] Figure 3 It is a sectional view of Embodiment 2 of the present invention;

[0022] In the figure: 1, envelope; 2, upper cover; 21, limit ring; 22, buffer block; 3, piston; 4, outer sleeve; 41, arc warp; 42, first cylinder; 43, second cylinder; 44, adjusting part. Detailed Embodiments

[0023] The following further describes the present application in detail with reference to the drawings. It is necessary to point out here that the following specific embodiments are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above application content.

[0024] Embodiment 1

[0025] Combined with Figure 1 and Figure 2 As shown, an air spring with a transverse vertical stiffness ratio greater than 1 includes an envelope 1, an upper cover 2 and a piston 3 that form a sealed chamber. The sealed chamber is filled with gas at a set pressure to expand the envelope 1. An outer sleeve 4 is connected to the outer periphery of the upper cover 2. The outer sleeve 4 extends vertically and wraps part of the outer side wall of the envelope 1. The reaction force of the outer sleeve 4 that laterally squeezes and expands the envelope 1 generates a lateral thrust on the upper cover 2 of the air spring. In this way, the interaction between the outer sleeve 4 and the expanded envelope 1 generates a lateral stiffness of the air spring.

[0026] Preferably, in this embodiment, a limit ring 21 is provided on the bottom surface of the upper cover 2. The limit ring 21 has a certain height and is coaxially arranged with the upper cover 2. The top end of the envelope 1 tightly adheres to the bottom surface of the upper cover 2 horizontally and converges inward until it abuts against the outer wall of the limit ring 21. After the envelope 1 expands, the matching structure between the envelope 1 and the upper cover 2 can be stable and the airtightness is good.

[0027] Preferably, in this embodiment, a buffer block 22 is provided at the center position of the bottom surface of the upper cover 2. The buffer block 22 is fixed on the upper cover 2 and can support and carry the weight in the case of lack of air in the air spring, protecting the envelope 1 of the air spring from damage.

[0028] Preferably, in this embodiment, the set pressure is 0.5 - 0.7 MPa, such as 0.5 MPa, 0.6 MPa, 0.7 MPa, etc. Its magnitude will affect the magnitude of the lateral thrust.

[0029] Preferably, in this embodiment, the outer sleeve 4 is integrally cylindrical, and the top of the outer sleeve 4 is welded to the outer periphery of the upper cover 2 as a whole. An arc-shaped warp 41 with a smooth surface is formed at the bottom end of the outer sleeve 4. The function of the arc-shaped warp 41 is that it is not easily damaged when the bladder 1 flexes. In this way, while achieving the purpose of improving the lateral stiffness of the air spring body, the fatigue life of the air spring bladder 1 can be ensured to meet the requirements.

[0030] Preferably, in this embodiment, the vertical height of the outer sleeve 4 is 60 - 150 mm, which can be configured according to the specific vehicle driving requirements.

[0031] Next, adjust the total height and the pressure in the sealed chamber of the air spring in Embodiment 1, and conduct corresponding vertical stiffness and lateral stiffness tests. The test results are shown in Tables 1 and 2 below:

[0032] Table 1: Data Table of Vertical Dynamic Characteristics

[0033]

[0034] Table 2: Data Table of Lateral Dynamic Characteristics

[0035] Height (mm) Air pressure (bar) Stroke (mm) Lateral stiffness (N / mm) 240 0.65 ±25 155 270 0.65 ±25 140 300 0.65 ±25 139

[0036] As can be seen from Tables 1 and 2, the ratio of the lateral and vertical stiffnesses of the air spring produced by the present invention is greater than 1. The adjustment of the lateral stiffness can be achieved by changing the total height: when the vertical height of the outer sleeve 4 is fixed within a reasonable range, such as 90 mm used in the test, as the total height gradually increases from 240 mm, 270 mm to 300 mm, the greater the height of the outer sleeve 4 that is not wrapped, the greater the negative lateral stiffness, and the smaller the total lateral stiffness; when the total height is fixed, such as 270 mm used in the test, with the increase of the air pressure, the vertical stiffness will gradually increase. In addition, the lateral stroke of the air spring assembly is large, the stiffness change is gentle, and it can provide a more comfortable support performance.

[0037] Embodiment 2

[0038] Based on Embodiment 1, the structure of the outer sleeve 4 in this embodiment is optimized. Specifically, an outer sleeve 4 with an adjustable vertical height is adopted, and: when the vertical height of the outer sleeve 4 increases, the lateral stiffness of the air spring increases, and the lateral-to-vertical stiffness ratio increases; when the vertical height of the outer sleeve 4 decreases, the lateral stiffness of the air spring decreases, and the lateral-to-vertical stiffness ratio decreases. In this way, after the air spring product is installed on the vehicle, its lateral stiffness can be adjusted according to the owner's needs and preferences without replacing the product.

[0039] Specifically, as shown in Fig. 3, the outer sleeve 4 is composed of a first cylinder 42 and a second cylinder 43. The first cylinder 42 is welded to the outer periphery of the upper cover 2, and the second cylinder 43 is coaxially and movably sleeved with the first cylinder 42, and the two can slide relative to each other. In this way, by changing the overlapping degree of the second cylinder 43 and the first cylinder 42, the vertical height of the outer sleeve 4 can be adjusted, and thus the lateral stiffness of the air spring can be adjusted.

[0040] In addition, an adjusting member 44 is provided on the outer peripheral wall of the first cylinder 42 for changing the overlapping degree of the second cylinder 43 and the first cylinder 42. The adjusting member 44 can be in any form. For example Figure 3 the bolt adjustment adopted in [reference], in which lugs are provided on the outer walls of both the first cylinder 42 and the second cylinder 43. The bottom end of the bolt is rotatably connected to the lug of the second cylinder 43, and the upper part of the bolt is threadedly engaged with the lug of the first cylinder 42. In this way, by rotating the bolt, the second cylinder 43 can be adjusted up and down. After the adjustment is completed, it can be locked by two nuts to prevent loosening.

[0041] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. An air spring with a transverse to vertical stiffness ratio greater than 1, comprising a bladder skin (1) forming a closed chamber, an upper cover (2) and a piston (3), characterized in that: The sealed chamber is filled with gas of a set pressure to expand the bladder skin (1). The outer periphery of the upper cover (2) is connected to an outer sleeve (4). The outer sleeve (4) extends vertically and wraps around the outer wall portion of the bladder skin (1) so that the air spring generates lateral stiffness through the interaction force between the outer sleeve (4) and the expanded bladder skin (1).

2. An air spring with a lateral to vertical stiffness ratio greater than 1 according to claim 1, characterized in that: The bottom surface of the upper cover (2) is provided with a limiting ring (21), and the top end of the bag skin (1) is laterally close to the bottom surface of the upper cover (2) and closes inward until it abuts against the outer wall of the limiting ring (21).

3. The air spring with a lateral to vertical stiffness ratio greater than 1 according to claim 1, characterized in that: A buffer block (22) is provided at the center of the bottom surface of the upper cover (2).

4. The air spring with a lateral to vertical stiffness ratio greater than 1 according to claim 1, characterized in that: The set pressure is 0.5-0.7 MPa.

5. The air spring with a lateral to vertical stiffness ratio greater than 1 according to claim 1, characterized in that: The outer sleeve (4) is cylindrical in shape as a whole, and the top of the outer sleeve (4) is welded to the outer periphery of the upper cover (2) as a whole, and the bottom end of the outer sleeve (4) is formed with an arc-shaped curvature (41) with a smooth surface.

6. The air spring with a lateral to vertical stiffness ratio greater than 1 according to claim 1, characterized in that: The vertical height of the outer set (4) is 60-150 mm.

7. The air spring with a lateral to vertical stiffness ratio greater than 1 according to claim 1, characterized in that: The vertical height of the outer set (4) is adjustable, and: when the vertical height of the outer set (4) increases, the lateral stiffness of the air spring increases, and the lateral to vertical stiffness ratio increases; when the vertical height of the outer set (4) decreases, the lateral stiffness of the air spring decreases, and the lateral to vertical stiffness ratio decreases.

8. An air spring with a lateral to vertical stiffness ratio greater than 1 according to claim 7, characterized in that: The outer sleeve (4) is composed of a first cylinder (42) and a second cylinder (43), wherein the first cylinder (42) is connected to the outer periphery of the upper cover (2), and the second cylinder (43) is coaxially movably sleeved with the first cylinder (42), and the vertical height of the outer sleeve (4) is adjusted by changing the sleeve overlap between the second cylinder (43) and the first cylinder (42).

9. An air spring with a lateral to vertical stiffness ratio greater than 1 according to claim 8, characterized in that: An adjusting member (44) is provided on the outer peripheral wall of the first cylinder (42) for changing the overlapping degree of the sleeve connection between the second cylinder (43) and the first cylinder (42).

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