Method for connecting a separating plate of a vibration damper to a cylinder, vibration damper and motor vehicle

Abstract

Method for connecting a separating plate (3) of a vibration damper (1) to a cylinder (2) of the vibration damper (1) with the steps: - Providing the cylinder (2), - providing the separating plate (3), wherein a groove (7) is provided on the outer surface of the separating plate (3) into which a sealing element (8) is inserted, the outer diameter of which is smaller than the outer diameter of the separating plate (3), - Inserting the separating plate (3) into the cylinder (2) and positioning it at a predetermined height, and - Deformation of the cylinder (2) radially inwards such that a part of the cylinder (2) engages in the groove (7) of the separating plate (3).

Description

[0001] The invention relates to a method for connecting a separating plate of a vibration damper to a cylinder of the vibration damper.

[0002] In conventional twin-tube vibration dampers, a piston rod guide is located at one end and a bottom valve attached to a separator plate at the other end. Separator plates are typically sealed from the cylinder, i.e., provided with a seal. The corresponding sealing element is inserted into a groove, like a piston, and protrudes beyond it. The separator plate is then attached to the cylinder.

[0003] The piston rod guide itself can also be regarded as a separating plate.

[0004] It may happen that after connecting the separating plate and the cylinder, the tightness of the connection is not sufficient.

[0005] US Pat. No. 4,110,888 A describes a vibration damper with a compensation chamber extending between a separating plate and the base of a cylinder. A separating piston is guided axially within the compensation chamber, with the cylinder forming a sliding track with its inner wall. The space between the separating plate and the separating piston is filled with oil, while a gas cushion is located between the separating piston and the base of the cylinder.

[0006] The separator plate has a circumferential annular groove for accommodating a ring seal. The cylinder engages in the annular groove by means of a radial rolling action, thus securing the separator plate within the cylinder. An opening is provided within the cylinder that connects a working chamber remote from the piston rod with the oil-filled section of the compensation chamber. During assembly, the gas filling of the compensation chamber is provided via the open-ended cylinder.

[0007] DE 976 161 B discloses a telescopic shock absorber whose piston rod guide is fixed in a damper tube by means of a rolling mechanism. No further information on the geometric dimensioning of the sealing ring or on the filling of the telescopic shock absorber is disclosed.

[0008] In this context, DE 37 00 934 A1 and DE 31 28 723 A1 should also be mentioned, which also disclose a rolling of a cylinder for fixing a piston rod guide.

[0009] Based on this, it is the object of the present application to provide a method for connecting a separating plate and a cylinder in which the tightness of the connected parts is improved.

[0010] To solve this problem, the procedure mentioned above is provided with the following steps: - Providing the cylinder, - Providing the separating plate, wherein a groove is provided on the outer surface of the separating plate into which a sealing element is inserted, the outer diameter of which is smaller than the outer diameter of the separating plate, - Inserting the separator plate into the cylinder and positioning it at a specified height, and - Deformation of the cylinder such that part of the cylinder engages in the groove of the separating plate.

[0011] The core of the invention is considered to be that the outer diameter of the sealing element is smaller than the outer diameter of the separating plate. Accordingly, the sealing element is completely concealed in the groove and therefore does not touch the inner wall of the cylinder when the separating plate is inserted into the cylinder. It has been found that sealing problems can arise because the sealing element moves along the inner wall of the cylinder and can be damaged in the process. The steps described prevent damage to the sealing element, thereby improving the tightness between the separating plate and the cylinder.

[0012] A separator plate is any circular disk-shaped or ring-shaped element that has a groove on its annular outer surface, which in this case is a circumferential surface, for accommodating a sealing element. The separator plate can either separate two spaces within the cylinder, but it can also be provided at the end of a cylinder, where it separates the cylinder interior and exterior. For this purpose, the separator plate is not closed; rather, it usually has at least one opening for accommodating, for example, a valve or a piston rod guide.

[0013] Preferably, the separating plate is arranged at a distance from the ends of the cylinder, or the separating plate is arranged at a distance from the ends of the cylinder. Accordingly, it is arranged in the central region of the cylinder, which encompasses everything except the end regions. Here, the use of a separating plate with a sealing element that is completely concealed in a groove is particularly advantageous, since inserting the separating plate only into the end region hardly causes problems due to the sealing element being destroyed.

[0014] Advantageously, the working cylinder of the vibration damper can be used as the cylinder. As described, the separator plate does not need to be circular; a ring-shaped design is sufficient. Accordingly, the separator plate can, at least in principle, also enclose other cylinders. However, the separator plate is preferably attached to the innermost cylinder, especially in the working cylinder.

[0015] An elastomer is preferably used as the sealing element. Elastomers are flexible and elastic and can therefore be easily deformed.

[0016] A particularly advantageous option is to roll the cylinder for forming. This is a cost-effective and stable method of forming that can also be carried out with the required tolerance.

[0017] Preferably, the separating plate can have at least one opening that is connected to a valve. This means that the valve occupies the opening of the separating plate, and accordingly, a fluid intended to pass through the separating plate must flow through the valve.

[0018] The cylinder can preferably be deformed in such a way that the cylinder and the sealing element touch. This means that part of the deformed section and the sealing element come into contact. During rolling, the cylinder is rolled so deeply that the sealing element, which is hidden within the groove, and the cylinder have a contact surface. Particularly preferably, deformation of the cylinder takes place in such a way that part of the cylinder engages in the groove of the separating plate and preloads the sealing element. The sealing element is elastically deformed in the process. The cylinder is therefore preferably deformed in such a way that the cylinder presses the sealing element into the groove. This gives the cylinder a dual function. On the one hand, it holds the separating plate, and on the other hand, together with the sealing element, it also seals the connection point. The contact surface between the cylinder and the sealing element is an annular surface.The deformation of the cylinder is therefore uniform in the circumferential direction.

[0019] Particularly advantageously, a cylinder chamber comprising a compensation chamber and a separating piston can be attached to one side of the separating plate before inserting the separating plate. The oil-filled part of the cylinder chamber is connected to the cylinder's working chamber via the separating plate, while a gas is stored on the side of the separating piston facing away from the separating plate. In this way, the compensation chamber can be inserted into the cylinder of the vibration damper as a separate element.

[0020] The application also relates to a vibration damper for a motor vehicle with at least one cylinder and a separating plate for dividing the cylinder. The vibration damper is characterized in that the separating plate has a circumferential groove in which a sealing element is arranged. The outer diameter of the sealing element is smaller than the outer diameter of the separating plate, and the cylinder is deformed so that the sealing element and cylinder are in contact. Advantageous further developments of the vibration damper correspond to corresponding features of the method, to which reference is made in this regard.

[0021] The vibration damper can advantageously be a monotube damper. In addition to conventional monotube dampers with a single tube, any other damper that operates according to this principle is considered a monotube damper. This means that a gas volume enclosed in a cylindrical space serves as a compensation volume, preferably at one end of the vibration damper. In the case of recuperative vibration dampers, for example, several tubes can be provided, with the other tubes simply conducting the hydraulic medium to a pump or similar device. In terms of its operating principle, the damper functions as a monotube damper.

[0022] The invention also relates to a motor vehicle with a chassis that includes at least one vibration damper. The motor vehicle is characterized in that the vibration damper is designed as described.

[0023] Further advantages, features, and details are evident from the exemplary embodiments and figures described below. They show: Fig. 1 a vibration damper in partial view, Fig. 2 a section of the vibration damper according to Fig. 1 in detail, and Fig. 3 a flow diagram for attaching a separating plate to a vibration damper.

[0024] Fig. 1 shows a vibration damper 1 with a cylinder 2, a separating plate 3, a piston rod guide 4, a piston 5 and a piston rod 6. Although the vibration damper 1 has more tubes, its operating principle is like that of a single-tube damper.

[0025] The separating plate 3 has a groove 7 in which a sealing element 8 is located. In the area of ​​the groove 7, the cylinder 2 has a deformation point 9 that engages in the groove 7. At this point, the cylinder 2 is rolled, whereby the cylinder 2 is deformed such that the sealing element 8 and the cylinder 2 touch each other.

[0026] A cylinder chamber 10 is arranged below the separating plate 3. The cylinder chamber 10 has a compensation chamber 12 and a separating piston 14. The separating piston 14 also has a sealing element 16, which is annular and arranged in a groove. In contrast to the sealing element 8, the sealing element 16 protrudes beyond the outer side of the separating piston 14 when not installed, whereas in the installed state the sealing element 16 and the separating piston 14 or the outer side of the separating piston 14 have the same outer diameter. However, there is usually a slight play between the separating piston 14 and the inner wall of the cylinder chamber 10, so that the sealing element 16 always has a larger outer diameter than the separating piston 14. The sealing element 16 therefore seals by being clamped between the groove and the inner wall of the cylinder chamber 10.

[0027] On the side of the cylinder chamber 10 facing the valve 18, the cylinder chamber has at least one opening to hydraulically connect the space area 20 with the working chamber 22 of the cylinder.

[0028] Fig. 2 shows the area around the valve 18 in detail. The cylinder 2, in this case also called the container tube, is rolled up at the deformation point 9 in such a way that it touches the sealing element 8 and presses this against the inner wall of the groove 7. The groove 7 is introduced into the outer surface of the separating plate 3 and extends in the circumferential direction. This means that the groove 7 is an annular groove. Because the cylinder 2 is deformed in such a way that the cylinder 2 and the sealing element 8 touch, the cylinder 2, on the one hand, supports the separating plate 3 in a form-fitting manner, and on the other hand, the cylinder 2 itself also seals in interaction with the sealing element 8, which would not be possible without deformation of the cylinder 2 due to the design of the sealing element 8.

[0029] The sealing element 8 is designed as an elastomer. An opening is provided in the center of the separating plate 3, which connects the working chamber 22 and the space region 20 of the cylinder chamber 10 via the valve 18. In addition to the compensation chamber 12, the annular chamber 24 can also be used as a compensation chamber by openly connecting the compensation chamber 12 and the annular chamber 24. This has the further advantage that a gas filling device 26 can be provided in the region of the annular chamber 24, with which the compensation chamber 12 and the annular chamber 24 can be filled with gas. For connecting the compensation chamber 12 and the annular chamber 24, a channel 28, for example, is provided, which is also annular.

[0030] Fig.3 shows a flow diagram of a method for connecting a separating plate of a vibration damper to a cylinder of the vibration damper. In step S1, a cylinder is provided, and in step S2, a separating plate 3. On the outer surface of the separating plate, there is a groove 7 into which a sealing element 8 is inserted. The outer diameter of the sealing element 8 is smaller than the outer diameter of the separating plate 3. This already applies in the non-installed state. In an optional step S3, a cylinder chamber 10 is arranged on one side of the separating plate 3. This can be connected to the separating plate 3 in a form-fitting or friction-fitting manner. The fastening must be such that the separating plate 3 and the cylinder chamber 10 can be inserted together into the cylinder 2, which takes place in step S4.

[0031] In step S5, the assembly consisting of the separating plate 3 and the cylinder chamber 10 is axially positioned and deformed in the cylinder 2. Due to the recessed position of the sealing element 8, it cannot be damaged during insertion into the cylinder 2.

[0032] For deformation, the cylinder is deformed, in particular rolled, radially inwardly in the area of ​​the groove 7 of the separating plate 3. This holds the separating plate in a form-fitting manner in the axial direction and simultaneously preloads the sealing element 8 in the groove 7 of the separating plate 3, thereby reliably separating the gas chamber from the oil chamber.

[0033] The following step S6 may include further assembly steps, such as filling with gas or oil. Step S6 includes all subsequent work steps for assembling vibration damper 1. Reference symbol 1 vibration damper 2 cylinders 3 dividing plate 4 Piston rod guide 5 pistons 6 piston rod 7 grooves 8 Sealing element (separating plate) 9 Forming point 10 Cylinder chamber 12 Compensation space 14 separating pistons 16 Sealing element (separating piston) 18 Valve 20 room area 22 work space 24 annular space 26 Gas filling device 28 channel S1 step S2 step S3 step S4 Step S5 Step S6 Step

Claims

[1] Method for connecting a separating plate (3) of a vibration damper (1) to a cylinder (2) of the vibration damper (1) comprising the steps: - Providing the cylinder (2), - providing the separating plate (3), wherein a groove (7) is provided on the outer surface of the separating plate (3) into which a sealing element (8) is inserted, the outer diameter of which is smaller than the outer diameter of the separating plate (3), - Inserting the separating plate (3) into the cylinder (2) and positioning it at a predetermined height, and - Deformation of the cylinder (2) radially inwards such that a part of the cylinder (2) engages in the groove (7) of the separating plate (3). [2] Method according to claim 1, characterized by that the working cylinder of the vibration damper (1) is used as cylinder (2). [3] Method according to claim 1 or 2, characterized by that an elastomer is used as the sealing element (8). [4] Method according to one of the preceding claims, characterized by that the cylinder (2) is rolled for deformation. [5] Method according to one of the preceding claims, characterized by that the separating plate (3) has at least one opening which is connected to a valve (18). [6] Method according to one of the preceding claims, characterized by that the cylinder (2) is deformed so that the cylinder (2) and the sealing element (8) touch each other. [7] Method according to one of the preceding claims, characterized by that before the separating plate (3) is inserted, a cylinder chamber (10) is attached to one side of the separating plate (3), which cylinder chamber comprises a separating piston (14). [8] Vibration damper (1) for a motor vehicle with at least one cylinder (2) and a separating plate (3) for dividing the cylinder (2), characterized byin that a cylinder chamber (10) is fastened below the separating plate (3), in which cylinder chamber a separating piston (14) is arranged, wherein a working chamber (22) within the cylinder (2) is hydraulically connected to a space region (20) within the cylinder chamber (10) via a central opening within the separating plate (3), and the separating piston (14) separates the space region (20) from a gas-filled compensation chamber (12) within the cylinder chamber (10), and the compensation chamber (12) is connected via a channel (28) to an annular chamber (24) which is delimited by the cylinder chamber (10) and the cylinder (2), wherein a gas filling device (26) is arranged in the region of the annular chamber (24). [9] Vibration damper according to claim 8, characterized by that the cylinder (2) is rolled in the area of ​​the separating plate (3) [10] Vibration damper according to one of claims 8 or 9, characterized by that a sealing element (8) is designed as an elastomer [11] Vibration damper according to one of claims 8 to 10, characterized by that a valve (18) is arranged on the separating plate (3). [12] Vibration damper according to one of claims 8 to 11, characterized by that the vibration damper (1) is a single-tube damper. [13] Motor vehicle with a chassis comprising at least one vibration damper, characterized by that the vibration damper (1) is designed according to one of claims 8 to 12.

Images