Sleeve for vehicle air springs

Abstract

To provide a sleeve for a vehicle air spring that has improved durability and reduces manufacturing cost by simplifying components.SOLUTION: A sleeve for a vehicle air spring includes at least a first sleeve (520) and a second sleeve (540). The first sleeve (520) is open at both ends and includes a first circumferential portion (522) and a second circumferential portion (524). The second sleeve (540) is open at one end and includes a third circumferential portion (542). The third circumferential portion (542) of the second sleeve (540) is coupled to the second circumferential portion (524) of the first sleeve (520), and an end on an opposite side of the one end of the second sleeve (540) is formed in a closed structure (544).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a sleeve for a vehicle air spring, and more specifically, to a sleeve for a vehicle air spring that can improve the durability of the sleeve of the vehicle air spring and reduce the manufacturing cost by simplifying the parts.

Background Art

[0002] The suspension of an automobile exists between the vehicle body and the wheel, and is a device that connects the vehicle body and the wheel, these two rigid bodies, using one or a number of links, and is supported in the vertical direction by a spring, a shock absorber, etc., and in other directions, by appropriately harmonizing high rigidity and flexibility, it performs the function of mechanically and appropriately harmonizing the relative movement between the vehicle body and the wheel.

[0003] Such a suspension must effectively block irregular inputs from the road surface generated during the running of the vehicle and provide a comfortable riding feeling for the passengers, and must appropriately control the sway of the vehicle body generated by the driving behavior of the driver and the bending of the road surface to provide driving convenience, and must satisfy the basic condition of maintaining the vertical load at the ground contact surface of the tire at an appropriate level when running on an irregular road surface to ensure the maneuverability and stability of the vehicle during turning and braking and driving.

[0004] In order to satisfy such conditions, various types of suspensions have been developed and applied to vehicles. Recently, in high-class passenger cars, an air suspension that improves the riding feeling by changing the volume of the sleeve forming the air spring to change the air spring constant and automatically maintains the vehicle height by changing the amount of air is widely applied.

[0005] However, while these sleeves attach to surrounding components, there is a risk of air leakage at the attachment point, causing the air spring to malfunction and reducing its durability. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] European Patent No. 2,090,801 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The present invention aims to solve the aforementioned problems and provide a sleeve for a vehicle air spring that improves durability and reduces manufacturing costs through simplified parts.

[0008] Furthermore, the present invention aims to provide a sleeve for vehicle air springs that can improve product performance by improving the degree of design freedom.

[0009] Furthermore, the present invention aims to provide a sleeve for a vehicle air spring in which the flowability of the injection molding process is improved during the injection molding of each sleeve, thereby improving the quality of the sleeve, by dividing the sleeve into multiple parts and manufacturing each part by injection molding. [Means for solving the problem]

[0010] A sleeve 500 for a vehicle air spring according to one embodiment of the present invention comprises at least a first sleeve 520 and a second sleeve 540, wherein the first sleeve 520 is open at both ends and comprises a first circumferential portion 522 and a second circumferential portion 524, the second sleeve 540 is open at one end and comprises a third circumferential portion 542, the third circumferential portion 542 of the second sleeve 540 is coupled to the second circumferential portion 524 of the first sleeve 520, and the end of the second sleeve 540 opposite to the one end may be formed by a closing structure 544.

[0011] According to one embodiment of the present invention, the first sleeve 520 is an upper sleeve, the second sleeve 540 is a lower sleeve, the first circumferential portion 522 of the first sleeve 520 is attached to the top mount portion, and the outer surface of the closing structure 544 at the opposite end of the second sleeve 540 can be fixed to an end cap.

[0012] As an example, the closing structure 544 may include a disc 546 that closes the end of the second sleeve 540 opposite to the one end.

[0013] As an example, the closing structure 544 may further include a reinforcing portion 548 that protrudes from the disc 546. The reinforcing portion 548 is a bar, and each of its ends may be connected to the inner surface of the second sleeve 540.

[0014] The reinforcing portion 548 consists of a plurality of bars, each of which passes through the center of the disc, and the points where the plurality of bars connect to the inner surface of the second sleeve 540 can be arranged at equal intervals along the perimeter of the inner surface.

[0015] According to one embodiment of the present invention, one of the first sleeve 520 and the second sleeve 540 may be configured to include a region that forms a lobe.

[0016] The first sleeve 520 and the second sleeve 540 can be manufactured from thermoplastic material by injection molding.

[0017] According to one embodiment of the present invention, the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 are welded together, thereby allowing the second circumferential portion 524 to be attached to the third circumferential portion 542.

[0018] As an example, the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 are arranged to overlap each other, and one of the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 may have a step portion 549 formed along the circumferential direction for positioning the remaining sleeve.

[0019] As an example, the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 each include an outwardly extending flange, and the second circumferential portion 524 of the first sleeve 520 can be attached to the third circumferential portion 542 of the second sleeve 540 by welding the flange.

[0020] As an example, the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 are arranged to overlap each other, the inner sleeve in the overlapping region contains a laser energy absorbing material, the outer sleeve contains a laser energy permeable material, and the welding may be laser welding.

[0021] A sleeve for a vehicle air spring according to one embodiment of the present invention further includes an intermediate sleeve 660 interposed between the first sleeve 620 and the second sleeve 640, the intermediate sleeve 660 having a fourth circumferential portion 662 and a fifth circumferential portion 664 at both ends, the second circumferential portion 624 of the first sleeve 620 may be coupled to the fourth circumferential portion 662 of the intermediate sleeve 660, and the fifth circumferential portion 664 of the intermediate sleeve 660 may be coupled to the third circumferential portion 642 of the second sleeve 640.

[0022] The inner sleeve may contain carbon black. The intermediate sleeve may also contain carbon black. [Effects of the Invention]

[0023] According to an embodiment of the present invention, since the sleeve has a closed structure and its outer surface is coupled to the end cap, the risk of compressed air leakage inside the sleeve is reduced, which not only improves the durability of the sleeve but also reduces the number of components, facilitating assembly and reducing manufacturing costs.

[0024] In addition, when the sleeve is divided into a plurality of parts and each is injection-molded independently, the durability can be improved and the manufacturing efficiency of the sleeve can be enhanced. Also, the performance of the product can be improved by enhancing the design freedom.

[0025] Moreover, according to an embodiment of the present invention, when the sleeve is divided into a plurality of parts and each is manufactured by injection molding, the fluidity of the injection molding can be improved during the injection molding of each sleeve, and the quality of the sleeve can be enhanced.

Brief Description of the Drawings

[0026] [Figure 1] It is a perspective view of a sleeve according to an embodiment of the present invention. [Figure 2] It is an exploded perspective view of the sleeve illustrated in FIG. 1. [Figure 3] It is a cross-sectional view of the sleeve illustrated in FIG. 1. [Figure 4] It is a perspective view of the second sleeve as seen so that the upper surface of the closed structure is shown. [Figure 5] It is a perspective view of the second sleeve as seen so that the lower surface of the closed structure is shown. [Figure 6] It is a cross-sectional view of a sleeve according to still another embodiment of the present invention.

Modes for Carrying Out the Invention

[0027] The present invention can be modified in various ways and has many embodiments; however, specific embodiments will be described in detail with reference to the drawings. However, this is not intended to limit the present invention to specific embodiments, but should be understood to include all modifications, equivalents, or substitutes that fall within the spirit and technical scope of the present invention. In describing each drawing, similar reference numerals have been used for similar components. Terms such as 1st, 2nd, A, B, etc., may be used to describe various components, but such components should not be limited by such terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the 1st component may be named the 2nd component, and similarly, the 2nd component may be named the 1st component. The term "and / or" includes a combination of multiple related descriptions or any of multiple related descriptions. When a component is referred to as being "linked" or "connected" to another component, it should be understood that it may be directly linked or connected to the other component, but other components may be present in between. Conversely, when a component is described as being "directly connected" or "directly linked" to another component, it should be understood that there are no other components in between. The terminology used in this application is used solely to describe specific embodiments and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "includes" or "has" are intended to specify the existence of features, figures, stages, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preemptively exclude the possibility of the existence or addition of one or more other features, figures, stages, operations, components, parts, or combinations thereof. Furthermore, the terms "first" and "second" are used herein solely for distinguishing purposes and should be understood not to imply any order or priority or expectation in any way.Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as ideal or overly formal unless expressly defined herein. Furthermore, the term “about” should be understood herein to include the range of manufacturing tolerances in the art to which this invention pertains.

[0028] Where the specification and claims as a whole state that a part includes any component, this means that, unless otherwise stated, it does not exclude other components but may further include other components. Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] The air spring can be embodied by being positioned between the top mount and the end cap and acting as a spring. For example, the air spring may include a housing and a sleeve.

[0030] According to one embodiment of the present invention, one end of the sleeve may be hermetically fixed to a top mount and the other end to an end cap. The sleeve may be enclosed by a housing.

[0031] As an example, the sleeve is an air bladder whose volume can change due to the vertical movement of the top mount or end cap. In other words, the sleeve, which has a constant internal pressure, will change its volume due to the aforementioned vertical movement, and will act as a spring as the internal pressure changes accordingly.

[0032] Figure 1 is a perspective view of a sleeve according to one embodiment of the present invention. The sleeve shown in Figure 1 is the sleeve before it is mounted on the top mount portion and end cap and lobes are formed. Figure 2 is an exploded perspective view of the sleeve shown in Figure 1. Figure 3 is a cross-sectional view of the sleeve shown in Figure 1.

[0033] As illustrated in Figures 1 to 3, a sleeve 500 for a vehicle air spring according to one embodiment of the present invention may include at least a first sleeve 520 and a second sleeve 540. For example, the first sleeve 520 may be an upper sleeve and the second sleeve 540 may be a lower sleeve.

[0034] The first sleeve 520 may have both ends open and include a first circumferential portion 522 and a second circumferential portion 524. The first circumferential portion 522 of the first sleeve 520 may be coupled to the top mount portion.

[0035] The second sleeve 540 may have one end open and include a third circumferential portion 542. The second circumferential portion 524 of the first sleeve 500 may be coupled to the third circumferential portion 542 of the second sleeve 540. The end of the second sleeve 540 opposite to one end may be formed by a closing structure 544. The outer surface of the closing structure 544 at the opposite end of the second sleeve 540 may be fixed to an end cap (not shown) (which may be a wheel-side member).

[0036] Accordingly, in this invention, the opposite end of the second sleeve 540 is not connected to the end cap in an open structure, but rather its outer surface is connected to the end cap in a closed structure 544.

[0037] If the second sleeve 540 is to be joined in a way that leaves its end open, then a separate component for such a join must be additionally assembled to the end cap. For example, if the second sleeve 540 is to be hermetically welded to the end cap in a way that leaves its end open, the end cap itself is not designed to withstand such welding, so a separate component on which the open end of the second sleeve 540 can be welded must be hermetically assembled to the end cap.

[0038] In this invention, the opposite end of the second sleeve 540 is connected to an end cap by a closure structure 544, which reduces the risk of compressed air leaking from the sleeve 500. This not only improves the durability of the sleeve 500 but also reduces the number of parts, making assembly easier and potentially lowering manufacturing costs.

[0039] In Figure 2, the first sleeve 520 is configured to include a region that forms the rolling robe, but the second sleeve 540 may also be configured to include a region that forms the rolling robe.

[0040] In this invention, the sleeve 500 can be manufactured by dividing it into a sleeve that includes a region that forms a rolling loop and a sleeve that does not include such a region. Accordingly, while satisfying the high rigidity required for the sleeve 500, the design freedom of the sleeve 500 can be improved and the manufacturing efficiency of the sleeve can be improved at the same time.

[0041] For example, the first sleeve 520 and the second sleeve 540 may be made from the same material, but the sleeve that does not include the area for forming the rolling roof may be made from a material with higher rigidity than the remaining sleeves. This is because a material with higher rigidity may not be suitable for forming the rolling roof.

[0042] The first sleeve 520 and the second sleeve 540 can be manufactured from thermoplastic elastomer (TPE) material by injection molding.

[0043] Thermoplastic elastomer materials can be molded by injection molding, extrusion, blow molding, etc., like general plastic materials, and are reusable, while still possessing the properties of elastomers.

[0044] According to one embodiment of the present invention, the first sleeve 520 and the second sleeve 540 are manufactured independently by injection molding of a thermoplastic elastomer material, thereby improving the design freedom of the first sleeve 520 and the second sleeve 540. For example, the sleeve including the region in which the rolling loop is formed can be designed to have excellent rigidity and spring properties by having a change in thickness in the longitudinal direction (as described later).

[0045] Furthermore, the flowability of the sleeve 500 during injection molding can also be improved. In one embodiment of the present invention, the sleeve 500 may be designed so that its inner diameter differs in the longitudinal direction. However, if injection molding is performed on a single sleeve, this can cause poor flowability during injection molding, making quality control of the sleeve difficult. In the present invention, the sleeve 500 is manufactured in two parts: a first sleeve 520 and a second sleeve 540. This improves the flowability of the injection molding during injection molding.

[0046] According to one embodiment of the present invention, the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 can be attached to the third circumferential portion 542 of the second sleeve 540 by welding them together.

[0047] For example, the upper sleeve 520 and the lower sleeve 540 can be attached to the third circumferential portion 542 of the second sleeve 540 by arranging them (butt joint) so that the end of the second circumferential portion 524 of the first sleeve 520 and the end of the third circumferential portion 542 of the second sleeve 540 face each other, and then welding the opposing portions.

[0048] More preferably, according to one embodiment of the present invention, as shown in Figure 3, the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 may be arranged to overlap each other. The overlapping areas can be welded so that the second circumferential portion 524 of the first sleeve 520 can be attached to the third circumferential portion 542 of the second sleeve 540.

[0049] Furthermore, for such welding, a step portion for positioning the remaining sleeve may be formed along the circumferential direction on either the second circumferential portion 524 of the first sleeve 520 or the third circumferential portion 542 of the second sleeve 540. As an example, Figure 3 shows a case in which a step portion 549 is formed along the circumferential direction on the third circumferential portion 542 of the second sleeve 540.

[0050] Furthermore, according to one embodiment of the present invention, the first sleeve 520 and the second sleeve 540 can be joined by laser welding in the overlapping region. That is, the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 can be joined by laser welding along the circumferential direction. For this purpose, as an example, the inner sleeve may include a laser energy absorbing material, and the outer sleeve may include a laser-transmitting material. As an example of a laser energy absorbing material, the inner sleeve may include carbon black.

[0051] Furthermore, according to one embodiment of the present invention, the second circumferential portion 524 of the first sleeve 520 and the third circumferential portion 542 of the second sleeve 540 may each be configured to include an outwardly extending flange.

[0052] The flanges are positioned facing each other and in contact, and by welding the flanges together, the second circumferential portion 524 of the first sleeve 520 can be attached to the third circumferential portion 542 of the second sleeve 540.

[0053] Figure 4 is a perspective view of the second sleeve, showing the top surface of the closed structure. Figure 5 is a perspective view of the second sleeve, showing the bottom surface of the closed structure.

[0054] Referring to Figures 4 and 5, according to one embodiment of the present invention, the closing structure 544 may include a disc 546 that closes the opposite end of one end of the second sleeve 540.

[0055] As an example, the closing structure 544 may further include a reinforcing portion 548 that protrudes from the disc 546. The reinforcing portion 548 may be in the form of a bar, and each of its ends may be connected to the inner surface of the second sleeve 540. Multiple such bars may be provided, each passing through the center of the disc, and the points where the multiple bars connect to the inner surface of the second sleeve 540 may be arranged at equal intervals along the inner surface.

[0056] Figure 6 is a cross-sectional view of a sleeve according to yet another embodiment of the present invention.

[0057] Referring to Figure 6, the sleeve 600 according to one embodiment of the present invention may further include an intermediate sleeve 660 interposed between the first sleeve 620 and the second sleeve 640. For example, the second circumferential portion 624 of the first sleeve 620 may be coupled to the fourth circumferential portion 662 of the intermediate sleeve 660, and the fifth circumferential portion 664 of the intermediate sleeve 660 may be coupled to the third circumferential portion 642 of the second sleeve 640. The first circumferential portion 622 of the first sleeve 620 may be coupled to the top mount portion.

[0058] For example, by welding the second circumferential portion 624 of the first sleeve 620 to the fourth circumferential portion 662 of the intermediate sleeve 660, the second circumferential portion 624 of the first sleeve 620 can be attached to the fourth circumferential portion 662 of the intermediate sleeve 660, and by welding the fifth circumferential portion 664 of the intermediate sleeve 660 to the third circumferential portion 642 of the second sleeve 640, the fifth circumferential portion 664 of the intermediate sleeve 660 can be attached to the third circumferential portion 642 of the second sleeve 640.

[0059] For example, the second circumferential portion 624 of the first sleeve 620 can be attached to the fourth circumferential portion 662 of the intermediate sleeve 660 by arranging the first sleeve 620 and the intermediate sleeve 660 such that the end of the second circumferential portion 624 of the first sleeve 620 and the end of the fourth circumferential portion 662 of the intermediate sleeve 660 face each other, and then welding the opposing portions.

[0060] Through this, the design freedom of the sleeve 600 of the present invention can be further improved. For example, the first sleeve 620 and the second sleeve 640 can be independently manufactured from different materials, but in a structure that joins the first sleeve 620 and the second sleeve 640 to each other, the freedom of material selection for joining may be reduced. On the other hand, if an intermediate sleeve 660 is interposed between the first sleeve 620 and the second sleeve 640, even if materials that are not easy to join are selected for the first sleeve 620 and the second sleeve 640, the difficulty of joining can be solved through the intermediate sleeve 660.

[0061] More preferably, according to one embodiment of the present invention, as shown in Figure 6, the second circumferential portion 624 of the first sleeve 620 and the fourth circumferential portion 662 of the intermediate sleeve 660 may be arranged to overlap each other, and the fifth circumferential portion 664 of the intermediate sleeve 660 and the third circumferential portion 642 of the second sleeve 640 may be arranged to overlap each other. In such a case, additionally, a step portion 666 for positioning may be formed along the circumferential direction on either the fourth circumferential portion 662 of the intermediate sleeve 660 or the second circumferential portion 624 of the first sleeve 620, and a step portion 668 for positioning may be formed along the circumferential direction on either the fifth circumferential portion 664 of the intermediate sleeve 660 or the third circumferential portion 642 of the second sleeve 640. In Figure 6, as an example, a case in which step portions 666 and 668 are formed on the fourth circumferential portion 662 and the fifth circumferential portion 664 of the intermediate sleeve 660.

[0062] The second circumferential portion 624 of the first sleeve 620 and the fourth circumferential portion 662 of the intermediate sleeve 660 are arranged to overlap each other, and the overlapping region can be welded so that the second circumferential portion 624 of the first sleeve 620 can be attached to the fourth circumferential portion 662 of the intermediate sleeve 660. Similarly, the fifth circumferential portion 664 of the intermediate sleeve 660 and the third circumferential portion 642 of the second sleeve 640 are arranged to overlap each other, and the overlapping region can be welded so that the fifth circumferential portion 664 of the intermediate sleeve 660 can be attached to the third circumferential portion 642 of the second sleeve 640. In Figure 6, as an example, the intermediate sleeve 660 is positioned on the inside in the overlapping region, and the first sleeve 620 to the second sleeve 640 are positioned on the outside. In such cases, when the intermediate sleeve 660 and the first sleeve 620 or second sleeve 640 are laser-welded, the intermediate sleeve 660 may be made of a laser energy absorbing material (e.g., carbon black), and the first sleeve 620 and second sleeve 640 may be made of a laser-transmitting material.

[0063] Furthermore, according to one embodiment of the present invention, the second circumferential portion 624 of the first sleeve 620 and the fourth circumferential portion 662 of the intermediate sleeve 660 may each be configured to include an outwardly extending flange. The flanges are arranged to face each other and in contact, and the flanges can be welded to attach the second circumferential portion 624 of the first sleeve 620 to the fourth circumferential portion 662 of the intermediate sleeve 660.

[0064] Similarly, the fifth circumferential portion 664 of the intermediate sleeve 660 and the third circumferential portion 642 of the second sleeve 640 may each be configured to include an outwardly extending flange. The flanges are positioned to face and contact each other, and the fifth circumferential portion 664 of the intermediate sleeve 660 may be attached to the third circumferential portion 642 of the second sleeve 640 by welding the flanges. [Explanation of Symbols]

[0065] 500, 600: Sleeves 520: First Sleeve 540: Second sleeve 660: Intermediate sleeve

Claims

1. A sleeve (500) for a vehicle air spring, The sleeve (500) includes at least a first sleeve (520) and a second sleeve (540), The first sleeve (520) has both ends open and includes a first circumferential portion (522) and a second circumferential portion (524). The second sleeve (540) has one end open and includes a third circumferential portion (542), the third circumferential portion (542) of the second sleeve (540) is connected to the second circumferential portion (524) of the first sleeve (520), The end of the second sleeve (540) opposite to the one end is formed by a closed structure (544), The closing structure (544) includes a disc (546) configured to close the end of the second sleeve (540) opposite to the one end, and a reinforcing portion (548) formed protruding from the inner surface of the disc (546). The reinforcing portion (548) is a bar, each of which is connected to the inner surface of the second sleeve (540), forming a sleeve for a vehicle air spring.

2. The first sleeve (520) is an upper sleeve, and the second sleeve (540) is a lower sleeve. The first circumferential portion (522) of the first sleeve (520) is connected to the top mount portion. The sleeve for a vehicle air spring according to claim 1, wherein the outer surface of the closing structure (544) at the opposite end of the second sleeve (540) is coupled to an end cap.

3. The sleeve for a vehicle air spring according to claim 1, wherein the reinforcing portion (548) is a plurality of bars, each of the plurality of bars passing through the center of the disc, and the points where the plurality of bars connect to the inner surface of the second sleeve (540) are arranged at equal intervals along the perimeter of the inner surface.

4. A sleeve for a vehicle air spring according to claim 1, wherein one of the first sleeve (520) and the second sleeve (540) is configured to include a region that forms a lobe.

5. The sleeve for a vehicle air spring according to claim 1, wherein the first sleeve (520) and the second sleeve (540) are manufactured from a thermoplastic material by injection molding.

6. A sleeve for a vehicle air spring according to claim 1, wherein the second circumferential portion (524) of the first sleeve (520) and the third circumferential portion (542) of the second sleeve (540) are welded together so that the second circumferential portion (524) is attached to the third circumferential portion (542).

7. The second circumferential portion (524) of the first sleeve (520) and the third circumferential portion (542) of the second sleeve (540) are arranged to overlap each other. A sleeve for a vehicle air spring according to claim 6, wherein one of the second circumferential portion (524) of the first sleeve (520) and the third circumferential portion (542) of the second sleeve (540) has a step portion (549) formed along the circumferential direction for positioning the remaining sleeve.

8. Each of the second circumferential portion (524) of the first sleeve (520) and the third circumferential portion (542) of the second sleeve (540) includes a flange extending outward. The sleeve for a vehicle air spring according to claim 6, wherein the flange is welded so that the second circumferential portion (524) of the first sleeve (520) is attached to the third circumferential portion (542) of the second sleeve (540).

9. The second circumferential portion (524) of the first sleeve (520) and the third circumferential portion (542) of the second sleeve (540) are arranged to overlap each other. The sleeve positioned on the inside in the aforementioned overlapping region contains a laser energy absorbing material. The outer sleeve contains a material that allows laser energy to pass through. The sleeve for a vehicle air spring according to claim 6, wherein the welding is laser welding.

10. The present invention further includes an intermediate sleeve (660) interposed between the first sleeve (620) and the second sleeve (640), The intermediate sleeve (660) includes a fourth circumferential portion (662) and a fifth circumferential portion (664) at both ends, A sleeve for a vehicle air spring according to claim 1, wherein the second circumferential portion (624) of the first sleeve (620) is coupled to the fourth circumferential portion (662) of the intermediate sleeve (660), and the fifth circumferential portion (664) of the intermediate sleeve (660) is coupled to the third circumferential portion (642) of the second sleeve (640).

11. The sleeve for a vehicle air spring according to claim 9, wherein the sleeve positioned on the inside comprises carbon black.

12. The intermediate sleeve comprises carbon black, a sleeve for a vehicle air spring according to claim 10.

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