Sleeve for vehicular air spring and vehicular air spring including the same

Abstract

To provide a sleeve for a vehicle air spring which achieves improvement of durability and manufacturing efficiency of the sleeve, and to provide a vehicle air spring including the same.SOLUTION: A sleeve for a vehicle air spring according to one embodiment of the invention includes at least an upper sleeve and a lower sleeve. An upper end circumferential portion of the upper sleeve is coupled to a top mount part, a lower end circumferential portion of the upper sleeve is adhered to an upper end circumferential portion of the lower sleeve. A lower end circumferential portion of the lower sleeve is coupled to a piston portion, and one of the upper sleeve and the lower sleeve may be formed so as to include an area which forms a lobe.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sleeve for an air spring for a vehicle and an air spring for a vehicle including the same, and more particularly to a sleeve for an air spring for a vehicle, in which the durability of the sleeve for the air spring for a vehicle is improved and manufacturing efficiency of the sleeve is improved, and an air spring for a vehicle including the same. [Background technology]

[0002] An automobile suspension is a device that exists between the body and the wheels, and connects these two rigid bodies using one or more links. It is supported in the vertical direction by springs and shock absorbers, and in other directions, it performs the function of mechanically harmonizing the relative movement between the body and the wheels by appropriately balancing high rigidity and flexibility.

[0003] Such a suspension must satisfy the following basic requirements: it must effectively block out irregular road inputs that occur while the vehicle is running, providing passengers with a comfortable ride; it must provide driving convenience by appropriately controlling the shaking of the vehicle body caused by the driver's driving actions and curvature of the road; and it must maintain an appropriate level of vertical load on the tire's contact surface when running on irregular road surfaces, ensuring maneuverability and stability of the vehicle when cornering, braking, and driving.

[0004] In order to satisfy these conditions, various types of suspensions have been developed and applied to vehicles. Recently, air suspensions that improve ride comfort by changing the volume of the sleeve that forms the air spring to change the air spring constant and automatically maintain the vehicle height by changing the amount of air are widely used in luxury passenger cars.

[0005] Since such sleeves are repeatedly deformed, they need to have excellent durability, but conventional sleeves have had difficulty in satisfying this requirement. For example, to improve durability, conventional rubber sleeves have had to undergo a complicated fiber-reinforced process to reinforce their rigidity, but this has led to a problem of a significant drop in the efficiency of sleeve manufacturing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent No. 2,090,801 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a sleeve for a vehicle air spring, which has improved durability and improved manufacturing efficiency of the sleeve, and an air spring for a vehicle including the same.

[0008] Another object of the present invention is to provide a sleeve for an air spring for a vehicle, and an air spring for a vehicle including the same, which can improve product performance by improving design freedom.

[0009] Also, the present invention provides a sleeve for a vehicle air spring, which allows easy stress management of the material through management of the expansion rate of the sleeve, and an air spring for a vehicle including the same.

[0010] In addition, the present invention provides a sleeve for an air spring for a vehicle, in which the sleeve is divided into a plurality of pieces and each piece is manufactured by injection molding, thereby improving the flowability of the injection molding during injection molding of each sleeve and improving the quality of the sleeve, and an air spring for a vehicle including the same. [Means for solving the problem]

[0011] A sleeve 500 for a vehicle air spring according to one embodiment of the present invention includes at least an upper sleeve 520 and a lower sleeve 540, an upper circumferential portion 522 of the upper sleeve 520 is connected to a top mount portion, a lower circumferential portion 524 of the upper sleeve 520 is connected to an upper circumferential portion 542 of the lower sleeve 540, and a lower circumferential portion 544 of the lower sleeve 540 is connected to a piston portion, and one of the upper sleeve 520 and the lower sleeve 540 may be configured to include a region forming a lobe.

[0012] The upper sleeve 520 and the lower sleeve 540 may be made of a thermoplastic material by injection molding.

[0013] For example, the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 may be attached to the upper circumferential portion 542 of the lower sleeve 540 by welding the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 .

[0014] According to one embodiment of the present invention, the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 are arranged to overlap each other, and one of the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 may have a step portion 546 formed along the circumferential direction for positioning the remaining sleeve.

[0015] As another embodiment, the lower circumferential portion 524 of the upper sleeve 520 may include a first flange extending outward, and the upper circumferential portion 542 of the lower sleeve 540 may include a second flange extending outward, and the lower circumferential portion 524 of the upper sleeve 520 may be attached to the upper circumferential portion 542 of the lower sleeve 540 by welding the first flange and the second flange.

[0016] In addition, the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 are arranged to overlap each other, the sleeve arranged on the inside in the overlapping area includes a laser energy absorbing material and the sleeve arranged on the outside includes a laser energy transparent material, and the welding can be laser welding.

[0017] According to one embodiment of the present invention, the sleeve for the vehicle air spring further includes an intermediate sleeve 660 interposed between the upper sleeve 620 and the lower sleeve 640, and a lower circumferential portion 624 of the upper sleeve 620 may be connected to an upper circumferential portion 662 of the intermediate sleeve 660, and a lower circumferential portion 664 of the intermediate sleeve 660 may be connected to an upper circumferential portion 642 of the lower sleeve 640.

[0018] As an example, the lower circumferential portion 624 of the upper sleeve 620 and the upper circumferential portion 662 of the intermediate sleeve 660 may be welded together, thereby attaching the lower circumferential portion 624 of the upper sleeve 620 to the upper circumferential portion 662 of the intermediate sleeve 660, and the lower circumferential portion 664 of the intermediate sleeve 660 may be welded together to the upper circumferential portion 642 of the lower sleeve 640, thereby attaching the lower circumferential portion 664 of the intermediate sleeve 660 to the upper circumferential portion 642 of the lower sleeve 640.

[0019] In addition, the lower circumferential portion 624 of the upper sleeve 620 and the upper circumferential portion 662 of the intermediate sleeve 660 are arranged to overlap each other, one of the upper circumferential portion 662 of the intermediate sleeve 660 and the lower circumferential portion 624 of the upper sleeve 620 may have a step portion 666 for positioning formed along the circumferential direction, and the lower circumferential portion 664 of the intermediate sleeve 660 and the upper circumferential portion 642 of the lower sleeve 640 are arranged to overlap each other, and one of the lower circumferential portion 664 of the intermediate sleeve 660 and the upper circumferential portion 642 of the lower sleeve 640 may have a step portion 668 for positioning formed along the circumferential direction.

[0020] In addition, the lower circumferential portion 624 of the upper sleeve 620 and the upper circumferential portion 662 of the intermediate sleeve 660 are arranged to overlap each other, the lower circumferential portion 664 of the intermediate sleeve 660 and the upper circumferential portion 642 of the lower sleeve 640 are arranged to overlap each other, the sleeve arranged on the inside in the overlapping area includes a laser energy absorbing material and the sleeve arranged on the outside includes a laser energy transparent material, and the welding can be laser welding.

[0021] As another example, the lower circumferential portion 624 of the upper sleeve 620 may include a third flange extending outward, and the upper circumferential portion 662 of the intermediate sleeve 660 may include a fourth flange extending outward, and the lower circumferential portion 624 of the upper sleeve 620 may be attached to the upper circumferential portion 662 of the intermediate sleeve 660 by welding the third flange and the fourth flange together, the lower circumferential portion 664 of the intermediate sleeve 660 may include a fifth flange extending outward, and the upper circumferential portion 642 of the lower sleeve 640 may include a sixth flange extending outward, and the lower circumferential portion 664 of the intermediate sleeve 660 may be attached to the upper circumferential portion 642 of the lower sleeve 640 by welding the fifth flange and the sixth flange together. Effect of the Invention

[0022] According to an embodiment of the present invention, the sleeve is divided into a plurality of pieces and each piece is injection molded independently, which improves durability and improves manufacturing efficiency of the sleeve. In addition, the performance of the product is improved by improving design freedom, and the stress of the material can be easily controlled by controlling the expansion rate of the sleeve.

[0023] In addition, according to one embodiment of the present invention, the sleeve is divided into a plurality of pieces, and each piece is manufactured by injection molding, so that the flowability of the injection molding during the injection molding of each sleeve can be improved, thereby improving the quality of the sleeve. [Brief description of the drawings]

[0024] [Figure 1]FIG. 2 is a perspective view of a sleeve according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the sleeve shown in FIG. [Diagram 3] FIG. 2 is a cross-sectional view of the sleeve shown in FIG. [Figure 4] FIG. 13 is a perspective view of a sleeve according to yet another embodiment of the present invention. [Diagram 5] FIG. 5 is an exploded perspective view of the sleeve shown in FIG. 4. [Figure 6] 5 is a cross-sectional view of the sleeve shown in FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present invention can be modified in various ways and can have various embodiments, and a specific embodiment will be described in detail with reference to the drawings. However, this is not intended to limit the present invention to a specific embodiment, and it should be understood that the present invention includes all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention. In describing each drawing, similar reference numerals are used for similar components. Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another component. For example, a first component may be named a second component, and similarly, the second component may be named a first component, without departing from the scope of the present invention. The term "and / or" includes a combination of multiple associated items or any item of multiple associated items. When a component is referred to as being "connected" or "connected" to another component, it should be understood that the other components may be directly connected or connected to the other components, but there may be other components in between. On the other hand, when a component is described as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between. The terms used in this application are merely used to describe a particular embodiment and are not intended to limit the present invention. The singular term includes the plural term unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. In addition, the terms "first" and "second" are used in this specification for the purpose of distinction only and should not be understood to indicate or predict any order or priority in any manner.Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention belongs. Terms as defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an ideal or overly formal sense unless expressly defined in this application. In addition, the term "about" should be understood in this specification to include the range of manufacturing tolerances in the art to which this invention belongs.

[0026] In the specification and claims, when a part includes a certain element, this does not mean excluding other elements, but may further include other elements, unless otherwise specified. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0027] The air spring may be disposed between the top mount portion and the piston portion and may be embodied to act as a spring. For example, the air spring may include a housing and a sleeve.

[0028] According to one embodiment of the present invention, the sleeve may be hermetically fixed to the top mount portion at one end and to the piston portion at the other end. The sleeve may be surrounded by a housing.

[0029] For example, the sleeve is an air bag whose volume can change with the up and down movement of the piston. That is, the sleeve, which has a certain pressure inside, changes its volume with the up and down movement, and the internal pressure changes accordingly, acting as a spring.

[0030] According to one embodiment of the present invention, the sleeve may be hermetically fixed to the top mount at one end and to the inner surface of the piston at the other end. The sleeve may be surrounded by a housing. When the piston moves axially upward relative to the piston, the bent portion of the sleeve, i.e., the portion where the rolling lobe is formed, may be rolled up together with the piston to form a circle. As a result, the air in the sleeve is compressed, and the air spring operates as a spring.

[0031] Fig. 1 is a perspective view of a sleeve according to an embodiment of the present invention. The sleeve shown in Fig. 1 is a sleeve before it is attached to a top mount portion and a piston portion and a lobe is formed. Fig. 2 is an exploded perspective view of the sleeve shown in Fig. 1. Fig. 3 is a cross-sectional view of the sleeve shown in Fig. 1.

[0032] 1 to 3, a sleeve 500 for an air spring for a vehicle according to an embodiment of the present invention may be generally cylindrical, for example, and may include at least an upper sleeve 520 and a lower sleeve 540. An upper circumferential portion 522 of the upper sleeve 520 may be coupled to a top mount portion, and a lower circumferential portion 524 of the upper sleeve 520 may be coupled to an upper circumferential portion 542 of the lower sleeve 540. A lower circumferential portion 544 of the lower sleeve 540 is coupled to a piston portion.

[0033] In FIG. 1, the lower sleeve 540 of the upper sleeve 520 and the lower sleeve 540 is configured to include a region that forms a rolling lobe, but the upper sleeve 520 may be configured to include a region that forms a rolling lobe.

[0034] In the present invention, the sleeve 500 can be manufactured separately into a sleeve including a region forming a rolling lobe and a sleeve not including such a region. Accordingly, while satisfying the high rigidity required for the sleeve 500, the design freedom of the sleeve 500 is improved and the manufacturing efficiency of the sleeve can be improved.

[0035] For example, the upper sleeve 520 and the lower sleeve 540 may be made of the same material, but the sleeve that does not include the area that forms the rolling lobe may be made of a material that is stiffer than the rest of the sleeve, because a stiffer material may not be suitable for forming a rolling lobe.

[0036] Additionally, the upper sleeve 520 and the lower sleeve 540 may be manufactured by injection molding using a thermoplastic elastomer (TPE) material.

[0037] Thermoplastic elastomer materials can be molded by injection or extrusion blow molding like ordinary plastic materials, and can be reused, but they also have the properties of an elastomer.

[0038] According to one embodiment of the present invention, the upper sleeve 520 and the lower sleeve 540 are independently manufactured by injection molding using a thermoplastic elastomer material, which improves the design freedom of the upper sleeve 520 and the lower sleeve 540. For example, the sleeve including the region where the rolling lobe is formed can be designed to have excellent stiffness and spring characteristics by having a thickness variation in the longitudinal direction.

[0039] In addition, the flowability of the sleeve 500 during injection molding can be improved. The sleeve 500 according to an embodiment of the present invention can be designed to have different inner diameters in the longitudinal direction, but this can cause poor flowability during injection molding when a single sleeve is injection molded, which can make quality control of the sleeve difficult. In the present invention, the sleeve 500 is manufactured separately into the upper sleeve 520 and the lower sleeve 540, and the flowability during injection molding can be improved.

[0040] According to one embodiment of the present invention, the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 may be attached to the upper circumferential portion 542 of the lower sleeve 540 by welding the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540.

[0041] For example, the lower circumferential portion 524 of the upper sleeve 520 can be attached to the upper circumferential portion 542 of the lower sleeve 540 by positioning the upper sleeve 520 and the lower sleeve 540 so that the ends of the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 face each other (butt joint) and welding the facing portions.

[0042] More preferably, according to one embodiment of the present invention, the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 may be disposed to overlap each other, as shown in Fig. 3. The overlapping area may be welded to attach the lower circumferential portion 524 of the upper sleeve 520 to the upper circumferential portion 542 of the lower sleeve 540.

[0043] In addition, for such welding, one of the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 may have a step portion formed in the circumferential direction for positioning the remaining sleeve. As an example, FIG. 3 shows a step portion 546 formed in the lower circumferential portion 524 of the upper sleeve 520 in the circumferential direction.

[0044] According to an embodiment of the present invention, the upper sleeve 520 and the lower sleeve 540 may be joined by laser welding in the overlapping region. That is, the lower end circumferential portion 524 of the upper sleeve 520 and the upper end circumferential portion 542 of the lower sleeve 540 may be joined by laser welding along the circumferential direction. To this end, as an example, the inner sleeve may include a laser energy absorbing material, and the outer sleeve may include a laser transmissible material. As an example of a laser energy absorbing material, the inner sleeve may include carbon black.

[0045] Additionally, according to one embodiment of the present invention, each of the lower circumferential portion 524 of the upper sleeve 520 and the upper circumferential portion 542 of the lower sleeve 540 may be configured to include an outwardly extending flange.

[0046] The flanges may be placed in opposing contact with one another and the flanges may be welded to attach the lower circumferential portion 524 of the upper sleeve 520 to the upper circumferential portion 542 of the lower sleeve 540 .

[0047] Fig. 4 is a perspective view of a sleeve according to yet another embodiment of the present invention, Fig. 5 is an exploded perspective view of the sleeve shown in Fig. 4, Fig. 6 is a cross-sectional view of the sleeve shown in Fig. 4.

[0048] 4 to 6, the sleeve 600 according to an embodiment of the present invention may further include a middle sleeve 660 interposed between the upper sleeve 620 and the lower sleeve 640. A lower circumferential portion 624 of the upper sleeve 620 may be coupled to an upper circumferential portion 662 of the middle sleeve 660, and a lower circumferential portion 664 of the middle sleeve 660 may be coupled to an upper circumferential portion 642 of the lower sleeve 640. A lower circumferential portion 644 of the lower sleeve 640 may be coupled to the piston portion. An upper circumferential portion 622 of the upper sleeve 620 may be coupled to the top mount portion.

[0049] As an example, the lower end circumferential portion 624 of the upper sleeve 620 and the upper end circumferential portion 662 of the intermediate sleeve 660 may be welded together to attach the lower end circumferential portion 624 of the upper sleeve 620 to the upper end circumferential portion 662 of the intermediate sleeve 660, and the lower end circumferential portion 664 of the intermediate sleeve 660 may be welded together to attach the lower end circumferential portion 664 of the intermediate sleeve 660 to the upper end circumferential portion 642 of the lower sleeve 640.

[0050] For example, the lower circumferential portion 624 of the upper sleeve 620 can be attached to the upper circumferential portion 662 of the intermediate sleeve 660 by positioning the upper sleeve 620 and the intermediate sleeve 660 so that the ends of the lower circumferential portion 624 of the upper sleeve 620 and the upper circumferential portion 662 of the intermediate sleeve 660 face each other and welding the opposing portions.

[0051] Through this, the sleeve 600 of the present invention can have a further improved degree of freedom in design. For example, the upper sleeve 620 and the lower sleeve 640 can be made of different materials independently, but in a structure in which the upper sleeve 620 and the lower sleeve 640 are joined together, the degree of freedom in selecting materials may be reduced due to the joining. On the other hand, when the intermediate sleeve 660 is interposed between the upper sleeve 620 and the lower sleeve 640, even if materials that are difficult to join are selected for the upper sleeve 620 and the lower sleeve 640, the difficulty in joining can be resolved through the intermediate sleeve 660.

[0052] More preferably, according to an embodiment of the present invention, as shown in Fig. 6, the lower circumferential portion 624 of the upper sleeve 620 and the upper circumferential portion 662 of the middle sleeve 660 may be arranged to overlap each other, and the lower circumferential portion 664 of the middle sleeve 660 and the upper circumferential portion 642 of the lower sleeve 640 may be arranged to overlap each other. In this case, additionally, one of the upper circumferential portion 662 of the middle sleeve 660 and the lower circumferential portion 624 of the upper sleeve 620 may have a step portion 666 for positioning formed along the circumferential direction, and one of the lower circumferential portion 664 of the middle sleeve 660 and the upper circumferential portion 642 of the lower sleeve 640 may have a step portion 668 for positioning formed along the circumferential direction. Fig. 6 shows, as an example, the step portions 666, 668 formed on the upper circumferential portion 662 of the middle sleeve 660 and the lower circumferential portion 664 of the middle sleeve 660.

[0053] The lower end circumferential portion 624 of the upper sleeve 620 and the upper end circumferential portion 662 of the intermediate sleeve 660 are arranged to overlap each other, and the overlapping region is welded, so that the lower end circumferential portion 624 of the upper sleeve 620 can be attached to the upper end circumferential portion 662 of the intermediate sleeve 660. Similarly, the lower end circumferential portion 664 of the intermediate sleeve 660 and the upper end circumferential portion 642 of the lower sleeve 640 are arranged to overlap each other, and the overlapping region is welded, so that the lower end circumferential portion 664 of the intermediate sleeve 660 can be attached to the upper end circumferential portion 642 of the lower sleeve 640. In FIG. 6, as an example, the intermediate sleeve 660 is arranged on the inside in the overlapping region, and the upper sleeve 620 to the lower sleeve 640 are arranged on the outside. In such an arrangement, where the middle sleeve 660 and the upper sleeve 620 or the lower sleeve 640 are laser welded together, the middle sleeve 660 may be made of a laser energy absorbing material (e.g., carbon black) and the upper sleeve 620 and the lower sleeve 640 may be made of a laser transmissive material.

[0054] Additionally, according to one embodiment of the present invention, the lower circumferential portion 624 of the upper sleeve 620 and the upper circumferential portion 662 of the middle sleeve 660 may each be configured to include an outwardly extending flange. The flanges may be disposed in opposing contact with one another, and the lower circumferential portion 624 of the upper sleeve 620 may be attached to the upper circumferential portion 662 of the middle sleeve 660 by welding the flanges.

[0055] Similarly, the lower circumferential portion 664 of the middle sleeve 660 and the upper circumferential portion 642 of the lower sleeve 640 may each be configured to include an outwardly extending flange. The flanges may be disposed in opposing contact with one another, and the lower circumferential portion 664 of the middle sleeve 660 may be attached to the upper circumferential portion 642 of the lower sleeve 640 by welding the flanges. [Explanation of symbols]

[0056] 500, 600: Sleeve 520: Upper sleeve 540: Lower sleeve 660: Intermediate sleeve

Claims

1. A sleeve (500) for a vehicle air spring, The sleeve includes at least an upper sleeve (520) and a lower sleeve (540); an upper circumferential portion (522) of the upper sleeve (520) is connected to a top mount portion, and a lower circumferential portion (524) of the upper sleeve (520) is connected to an upper circumferential portion (542) of the lower sleeve (540); A lower end circumferential portion (544) of the lower sleeve (540) is connected to the piston portion, A sleeve for an air spring for a vehicle, wherein one of the upper sleeve (520) and the lower sleeve (540) is configured to include a region that defines a lobe.

2. 2. The sleeve for a vehicle air spring according to claim 1, wherein said upper sleeve (520) and said lower sleeve (540) are made by injection molding from a thermoplastic material.

3. 2. The sleeve for a vehicle air spring of claim 1, wherein the lower end circumferential portion (524) of the upper sleeve (520) and the upper end circumferential portion (542) of the lower sleeve (540) are attached to the upper end circumferential portion (542) of the lower sleeve (540) by welding the lower end circumferential portion (524) of the upper sleeve (520) and the upper end circumferential portion (542) of the lower sleeve (540).

4. the lower end circumferential portion (524) of the upper sleeve (520) and the upper end circumferential portion (542) of the lower sleeve (540) are arranged to overlap each other; 4. A sleeve for a vehicle air spring as described in claim 3, wherein one of the lower end circumferential portion (524) of the upper sleeve (520) and the upper end circumferential portion (542) of the lower sleeve (540) has a step portion (546) formed along the circumferential direction for positioning the remaining sleeve.

5. each of the lower end circumferential portion (524) of the upper sleeve (520) and the upper end circumferential portion (542) of the lower sleeve (540) includes an outwardly extending flange; 4. The sleeve for a vehicle air spring of claim 3, wherein the flanges are welded to attach the lower circumferential portion (524) of the upper sleeve (520) to the upper circumferential portion (542) of the lower sleeve (540).

6. the lower end circumferential portion (524) of the upper sleeve (520) and the upper end circumferential portion (542) of the lower sleeve (540) are arranged to overlap each other; a sleeve disposed inwardly in the overlap region comprising a laser energy absorbing material; the outer sleeve includes a laser energy transparent material; 4. The sleeve for a vehicle air spring as claimed in claim 3, wherein said weld is a laser weld.

7. The method further includes the steps of: providing a middle sleeve (660) interposed between the upper sleeve (620) and the lower sleeve (640); 2. The sleeve for a vehicle air spring of claim 1, wherein a lower end circumferential portion (624) of the upper sleeve (620) is connected to an upper end circumferential portion (662) of the intermediate sleeve (660) and a lower end circumferential portion (664) of the intermediate sleeve (660) is connected to an upper end circumferential portion (642) of the lower sleeve (640).

8. the lower end circumferential portion (624) of the upper sleeve (620) and the upper end circumferential portion (662) of the intermediate sleeve (660) are welded together, thereby attaching the lower end circumferential portion (624) of the upper sleeve (620) to the upper end circumferential portion (662) of the intermediate sleeve (660); 8. The sleeve for a vehicle air spring of claim 7, wherein the lower end circumferential portion (664) of the intermediate sleeve (660) and the upper end circumferential portion (642) of the lower sleeve (640) are attached to the upper end circumferential portion (642) of the lower sleeve (640) by welding the lower end circumferential portion (664) of the intermediate sleeve (660) and the upper end circumferential portion (642) of the lower sleeve (640).

9. The lower end circumferential portion (624) of the upper sleeve (620) and the upper end circumferential portion (662) of the intermediate sleeve (660) are arranged to overlap each other, and one of the upper end circumferential portion (662) of the intermediate sleeve (660) and the lower end circumferential portion (624) of the upper sleeve (620) has a step portion (666) formed along the circumferential direction for positioning, 9. A sleeve for a vehicle air spring as described in claim 8, wherein the lower end circumferential portion (664) of the intermediate sleeve (660) and the upper end circumferential portion (642) of the lower sleeve (640) are arranged to overlap each other, and one of the lower end circumferential portion (664) of the intermediate sleeve (660) and the upper end circumferential portion (642) of the lower sleeve (640) has a step portion (668) for positioning formed along the circumferential direction.

10. The lower end circumferential portion (624) of the upper sleeve (620) and the upper end circumferential portion (662) of the intermediate sleeve (660) are arranged to overlap each other, The lower end circumferential portion (664) of the intermediate sleeve (660) and the upper end circumferential portion (642) of the lower sleeve (640) are arranged to overlap each other, a sleeve disposed inwardly in the overlap region comprising a laser energy absorbing material; the outer sleeve includes a laser energy transparent material; 9. The sleeve for a vehicle air spring as claimed in claim 8, wherein said weld is a laser weld.

11. the lower end circumferential portion (624) of the upper sleeve (620) and the upper end circumferential portion (662) of the intermediate sleeve (660) each include an outwardly extending flange; the lower end circumferential portion (624) of the upper sleeve (620) and the upper end circumferential portion (662) of the intermediate sleeve (660) are attached to the upper end circumferential portion (662) of the intermediate sleeve (660) by welding flanges of the lower end circumferential portion (624) of the upper sleeve (620) and the upper end circumferential portion (662) of the intermediate sleeve (660); the lower end circumferential portion (664) of the intermediate sleeve (660) and the upper end circumferential portion (642) of the lower sleeve (640) each include an outwardly extending flange; 9. The sleeve for a vehicle air spring of claim 8, wherein the lower end circumferential portion (664) of the intermediate sleeve (660) and the upper end circumferential portion (642) of the lower sleeve (640) are attached to the upper end circumferential portion (642) of the lower sleeve (640) by welding flanges of the lower end circumferential portion (664) of the intermediate sleeve (660) and the upper end circumferential portion (642) of the lower sleeve (640).

12. 2. A sleeve for a vehicle air spring as claimed in claim 1, wherein the sleeve not including the areas forming the lobes is made of a stronger material than the remainder of the sleeve.

13. 2. The sleeve for a vehicle air spring as claimed in claim 1, wherein the sleeve including the regions defining the lobes includes sections of varying thickness along the length of the sleeve.

14. 11. The sleeve for a vehicle air spring according to claim 6 or claim 10, wherein the inner sleeve contains carbon black.

15. A sleeve (500, 600) for a vehicle air spring according to any one of claims 1 to 13, a top mount portion to which the upper end circumferential portion (522, 622) of the upper sleeve (520, 620) is attached; An air spring for a vehicle, comprising a piston portion to which the lower end circumferential portion (544, 644) of the lower sleeve (540, 640) is attached.

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