SE528895C2 - Damper with sealing function is for vehicle and has fastening device permitting connection to reciprocally moving parts on vehicle - Google Patents

Abstract

The damper can be fastened to reciprocally moving parts on a vehicle and is provided with an enclosing piston and connecting rod arrangement together with a pressure guaranteeing component which ensures maintenance of pressure in the arrangement when a pressure-affecting parameter occurs which strives after another pressure. The piston connecting rod and its components are sealed in two gables or in a gable and a wall in the arrangement by only two seals and sealing components to achieve optimally low friction.

Description

10 20 20 25 30 528 895 cylinder travel can be reduced. The volume of the attenuator medium or attenuators must be kept within certain intervals to ensure the function of the attenuator. There is also a desire for the seal / seals / bushing / bushings to be placed as close to the main piston as possible in order to minimize the length of the piston rod arrangement and thereby minimize the total length of the damper without costly processing costs. In the event that a top loop is used, it must be easy to mount it at any angle to the damper body without the reading of the top loop interfering with the length of the damper. The purpose of the invention is also to solve all or parts of the specified additional problems.

What can mainly be considered as characteristic of a damper according to the invention appears from the characterizing part of the appended claim 1.

In a dry-release form, the pressure-guaranteeing means preferably comprises a gas separating piston. The piston rod or piston rod elements are arranged continuously and sealed by means of two seals / sealing elements in two ends or in an end and a wall.

The gas separating piston is located outside the path of movement of the current piston rod or current piston rod elements and is internally sealed with a seal against the top loop.

Because the gas separating piston is part of a connecting path for media communication between the upper and lower sides of the main piston, no or no extra channels need be arranged for the establishment of the media transport. This in turn entails opportunities to be able to reduce the volume of the damper as such and / or enable a reduced manufacturing cost in the damper.

The invention is advantageously used in dampers with assembled components such as cylinder, piston and piston rod arrangement, portion with accumulator and fastening means in a common unit, in which the invention can take hold of the complete sealing function between moving parts. 10 15 20 25 30 528 893 Further developments of the idea of recovery are set out in the following subclaims. Where, for example, the piston rod arrangement is described to run inside a recess sealed against the damper head in the cylindrical part of the top loop so that the arrangement can work with an optimally small fi-iction.

Due to the construction and mounting of the top loop, it can be rotated around its longitudinal axis and locked in any direction of rotation along the longitudinal axis. The angle of rotation can be adjusted without the risk of leakage from the damper. At the same time, the top loop can be assigned angular positions where it is optimized for connection in the current moving part in or on the vehicle.

Through this angle of rotation adjustment, it is possible to adjust in which direction the adjusting means point. This is to facilitate the setting of the vehicle.

A presently proposed embodiment of a damper having the characteristics characteristic of the invention will be described in the following with simultaneous reference to the accompanying drawings, in which fi Figure 1 shows in principle a damper and components connected thereto or included, Figure 2 in longitudinal section shows parts of a constructive embodiment of the damper, ñgur 3 in cross section and enlarged in relation to figuren 2 shows the damper according to figuren 2, figures 4-6 in longitudinal section and enlarged shows the components of the damper at the damper head, and figur 7 in end view shows the damper's detailed Construction.

In Figure 1, parts of a damper are in principle indicated by 1. In the exemplary embodiment, the damper consists of a pair of double-pipe mandrels, the outer pipes of which are indicated by 2 and the inner pipes by 3. The pipes are arranged with intermediate gap 4 and have passages 5 at the first end of the damper. 6 went to a media arranged in the damper. The damper may be of the type comprising a main piston 7 and a piston rod 8 extending through the main piston 7, wherein the piston rod dividers at one side of the piston are indicated by Sa and the piston rod portion at the other side of the piston is indicated by Sb . The compression space or compression cycle of the damper is indicated by 9 and the expansion circumference or expansion side by 10. The piston and the piston rod are slidably arranged in the cylinder bore 9, 10 in the directions of the arrows 11. The piston 7 operates in a medium 13 which preferably consists of hydraulic oil which may comprise associated additives in a manner known per se. Alternatively, glycol and / or water can be used as a liquid. The piston rod 8a and 8b can extend from the upper and lower sides 7a and 7b of the piston, respectively. The piston rod may in principle comprise piston rod element parts which may be more than one in number. Thus, the piston rod part 8a and / or 8b may consist of more than one piston rod part or piston rod element. So e.g. For example, the piston rod part 8a may be a piston rod part, while the piston rod part 8b may be replaced by two or two piston rod elements. The end parts of the damper are indicated by 12 and 12 ”. The piston rod end 8c of the piston rod part 8a has mounting means 15 (eg end loop) for a part of a vehicle in question, which part can be constituted by a wheel suspension part (hub, spindle, etc.) 14. At the damper end 8d the damper has a mounting means 15 '(eg top loop) which can be attached to a chassis part 16 of a vehicle in question.

The damper is arranged with a valve arrangement which is in principle indicated by 17.

The valve arrangement is referred to in the present application as a working body. Said means comprise a first damping force generating valve or compression damping valve 18 and a first non-return valve 19. In addition, a second damping force generating valve or return damping valve 20 and a second non-return valve 21 are included. These damping force generating valves may themselves be one or two parallel valves. and / or series-connected valves. In accordance with Figure 1, an accumulator or gas container 22 is also included which comprises a separating piston 23. The gas container encloses in a first space 22a medium 13, e.g. said hydraulic oil with any additives or other liquid (see above). The gas container also has a second space 22b which comprises a second medium 24 which is more compressible than the medium 13. The medium 24 may be gas, e.g. air, nitrogen or other gas with additives. Said working means 17 also comprises connections which connect said valves 18, 19, 20 and 21 and the space 22a in the container 22 as well as the gap 4 and the spaces 9 and 10 in the damper. In this drying example, the gap 4 and the space 10 can be considered as a common space.

Said valves 18 and 19 are thus included in a first loop comprising the space 9, the connection 27 ", the space 22a, and the connection 27, and where the gap 4, the passage (s) 5 and 6 are connected as well as the space 10. A second loop is constituted by valves 20 and 10 15 20 25 30 528 895 21 with otherwise the same connections. The flow direction in connection with compression of the shock absorber, often referred to as the compression phase, is indicated by the arrows 26, while the flow direction in connection with the separation of the shock absorber, often referred to as the return phase, is indicated by the arrows 26 ”. In the main piston 7, valves that are used in combination with other valves are fully possible in one embodiment. The first damping generating valve 18 is connected at one end to the space 9 in the damper, while the first non-return valve 19 is connected to the gap 4. The second damping generating valve 20 is connected to the gap 4, while the second non-return valve is connected to the space 9 Said first valves 18 and 19 are also connected via the connections 27 ', 22a and 27 to the second valves 20 and 21. During compression movement in the damper, i.e. when the piston 7 moves to the left in the 1 clock 1, the medium 13 is pushed via the valve 18 and the intermediate connection and the non-return valve 19 into the gap 4. The gap 4 thus leads the medium derived from the space 9 to the space 10. Depending on the design of the valve 20 or smaller medium is also led from the space 9, via the valve 18, the connection 27 ', the space 22a, the connection 27 and the rear path through the valve 20 (ie towards the specified arrow direction 26') and the gap 4 to the space 10, cf. bleed function.

Correspondingly, in the case of expansion operations, ie. the movement of the piston to the right in the uren guren 1, the medium from the space 10 to the space 9 via intermediate connections, the gap 4, the valve 20, the space 22a and the valve 21. Here too it applies that more or less medium can be led e.g. via the connections 27, 27 'and the rear wave through the valve 18 (against the indicated arrow direction 26) to the space 9, compare bleed function. This transfer function between spaces 9 and 10 is referred to in the present application as a positive pressure build-up, which is characterized in that the medium located on the side facing away from the direction of movement of the piston is prevented from substantially falling below a media pressure existing before the piston in motion. As the piston moves to the left in the 1 clock 1, the medium in the space 10 will thus maintain its significant pressure value despite the movement. Correspondingly, the media in the space 9 retains its pressure value when the piston moves to the right thanks to the said media transfer. If e.g. the piston moves in the direction of the arrow, the increase in pressure at the side 7a facing the piston in the direction will be raised by the valve function 18 at the same time as cavitation effects are avoided at the side 7b facing from the direction of movement 11a. The same thus applies to movements in the direction of the arrow llb. The direction of movement of the medium at the gap 4 and the passages 5 and 6 in the damper have been indicated by 28. In the fi clock 1 a low pressure zone 29 is also shown for the circled or enclosed medium, which can be e.g. of hydraulic oil, nitrogen gas, etc. 10 15 20 25 30 528 895 Approached gas containers with the gas separating piston 23 guarantee that mandatory pressurization, ie. suitable media pressure, is present in the damper 1 in case of volume changes. Thus, appropriate pressure levels are ensured during the changes of sealed volume due to e.g. temperature changes in the media volume, changes in piston rod displacement, etc.

The pressurization means that the absolute pressure level is maintained at a sufficient level, e.g. at a level of about 2 bar or higher, to minimize the risk of cavitation due to the present throttles in current channels. The essential maintenance of the gas pressure on the media volume facing from the direction of movement is to some extent determined by the pressure drop caused by the valves and the pipes or ducts. However, the media pressure on the side facing from the direction of movement must be maintained to a significant degree in line with the value present at a stationary piston. In Figure 1, forces transmitted to the piston rod by F1 and F2 are shown. Regarding the valves 18 and 20, these have been shown only symbolically. In addition to the valve furilction itself, there are also surrounding arrangements in a manner known per se, e.g. arrangements including springs, cones, fixed struts, shims, etc., of iron or steel below. Regarding the inner tube in the pair of double tube mandrels, this is shorter than the outer tube and comprises one or more open passages present between the gap 4 and the space 10. The reference numeral 25 is intended to symbolize the connecting system or said working means in its entirety.

Figure 2 shows a constructive embodiment of the damper 1 which has a shape which is here referred to as a double-tube door post. The door pair includes a damper head 30 (hereinafter referred to as the portion).

At one side of the damper head, the inner and outer pipes forming the double pipe damper are arranged. The gas pressure vessel 22 specified above is applied to or in the damper head, at its other side. The container 22 has the shape of an annular component which is sealed against the fastening means 15 'by means of seals 32 and 32 "saint against the damper head by means of seals 32" and 32 "'. In addition, a seal 31 is included which prevents leakage of damper medium to the interior of the fastening member. Said fastening means have a fastening part 15a and a cylindrical part 15b, on the outside of which said seals 31, 32 and 32 "are arranged. Said piston rod part 8b is arranged to be able to run inside the recess 15c of the cylindrical part during the movements of the piston. Pressure indicating means are shown with 33 and 33 ”. By means of these indicating means the position of the fl-surface piston 23 (see figure 1) can be indicated. In the present case, the piston is mounted on a common piston rod Sa, 8b which in itself may comprise assemblable parts. The piston rod arrangement is mounted with first and second bushings 35 and 36, the first bushing being arranged in connection with the damper head 30 and the second bushing 36 being arranged at the end 37. The adjusting means for adjusting the damper pair the attenuation character of the attenuator is indicated by 38 and 38a (see Figure 3). The various components of the dampers are otherwise sealed with sealing means in a manner known per se.

According to the clock 3, the damper may comprise two adjusting means, which are generally designated 38 and 38a. The adjusting means can be constructed in an identical manner and have the same working method. Respective adjusting means comprise a bleed valve 39, a cone valve 58, a shim valve 40 and a non-return valve 41 with wave washer 59 which creates a tensioning lug (which is preferably close to zero). The compression bleed valve is arranged parallel to the compression cone valve and the expansion bleed valve is arranged parallel to the expansion cone valve. The positions of the bleed valves can be changed from the outside with the help of tools, e.g. screwdriver, via co-operating means, such as can be constituted by chisel grooves 60. The cone valves are actuated against their respective seats 42 by means of prestressed springs 43. The prestressing of the springs is adjustable from the outside v by means of adjusting screw 44, which can be actuated with suitable tools, e.g. socket or block wrench. The size of the preload affects the opening pressure and thus the pressure differential across the main piston. The shim valves 40 are arranged at the front of the cone valves. The shape of the cone and the shim package or shim stack affect the damping characteristics.

The shim configuration can be varied. The structure of the damper with the placement of valves, non-return valves, gas containers, ducts, etc. enables the compression and expansion valves to work independently of each other. In one embodiment, a rigid shim stack can be used in combination with a small bias on the cone valve. The oil or liquid that is passed through the bleed valves and the shim stack can be very limited before the cone valve opens. The opening pressure of the cone valve depends on the designs of the cone valve and the valve seat and the bias of fi edema. By changing i.a. these parameters, the character of the attenuation curve can be changed or selected. The reference numeral 62 shows a channel leading to the column 4, while the reference numeral 63 shows a channel leading to the space 9. The channels to the space 22a start from the spaces 64, 64 °, which, however, is not shown in figure 2. Said inner tube can arranged to ensure maximum rigidity in the damper design. The damper uses bushings that are statically arranged so that a long minimum distance between the bushings (in this case design constant), compared to the case where the bushing is placed on the piston, to minimize the friction and achieve maximum rigidity in the damper when inserting 30 bending torques and side loads. In a preferred embodiment, the piston is arranged without bushing. As an alternative in such a case, a piston seal that meets non-concentricity can be used. Two identical seals of e.g. The x-ring type can be used, one of which is used for the externally outwardly extending piston rod part and the other for the displacement piston rod. Thanks to the low gas pressure, the friction from the seals can be kept at a low level. The gas container can be arranged with the same diameter as the valves, whereby the oil volume 22a between the gas separating piston and the cylinder head can be used to transport oil between the two valves.

The damper is arranged with said pressure indicators 33, 33 'in accordance with Figures 4, 5 and 6. The indicators operate with a number of functions. Bl.a. indicates the indicators whether the pair is pressurized or not. In a damper of this kind there is no force from the internal pressurization of the piston rod which leads out of the damper body. Therefore, it is difficult to determine whether the damper is pressurized or not. By influencing one or both of the pressure indicators, answers to any pressure setting can easily be obtained. When each indicator is pressed, the respective indicator will be pushed back outwards ï »by any pressure located inside. If no pressure is present, the indicator or indicators will assume their depressed positions. Figure 4 shows the pressure indicators in sub-. show pressed modes. The lugs or recesses where the pressure indicators can be viewed were used to tighten or loosen the top loop. The indicators can also be used to position the movable piston when the damper is filled or possibly emptied with oil.

The instrument in question was used on the top loop to position the piston in question.

In Figure 4, the push-in and release strokes are indicated by F3, F4, F5 and F6.

The separating piston is in this case shown with 45 and the gas volume of the gas container is shown with 22b '. The liquid volume in the container is indicated by 22a ”. Respective indicators 33, 33 "have the shape of a pin, the inner end 33a of which can be actuated by the pressure in the space 22b".

The lug 33b on the pressure indicator bottoms against the lug 62 in the container end in the event of internal overpressure and the absence of applied external force by means of tools (see, for example, fi clock 5) or equivalent. The pressure indicator pin can also be pressed in for abutment against the piston 45, whereby in a simple manner information is obtained about the position of the separating piston, e.g. setting mode. Regardless of the setting of the adjusting means 38 and 38a, the pressure in the space 22a ”can be maintained substantially constant. Reference numeral 46 denotes a channel suitable for filling oil sealed with a screw 47 in combination with an O-ring 61.

The screw bottoms against a seat 48. Figure 15 is intended to show the case at the abutment of the pin 33a against the upper surface 45a of the piston 45.

By depressing the respective pressure indicator 33, 33 'by means of tools 55, one can easily determine the indentation lengths L1 and L2 for the pressure indicator parts 33a and a gap L3 for the position of the piston 45 in relation to an inner surface 48 of the piston 45 opposite the bottom head 45. Thereby one can check that the position of the isolating piston 45 and thereby the damper medium level is within a predetermined approved working area.

By using two pressure indicators, it is understood that the influence of the piston by means of the pressure indicators can take place without a significant oblique load on the piston. The top loop can be locked in any direction of rotation along the longitudinal axis 53 by screwing the container end 63 via the thread 64 outwards towards the reading 65 and fixing the top loop in the desired rotational position. The tool 55 or equivalent can be used in this fastening operation. At said angular position of rotation, the top loop is rotated about said longitudinal axis. The angle of rotation can be adjusted without the risk of leakage from the damper. At the same time, the .top loop can be assigned angular positions where it is optimized for connection in the current moving part in. or on the vehicle. Through this angle of rotation adjustment, it is possible to adjust in which direction the adjusting means point. This is to facilitate the setting of the vehicle. When the top loop ~ has been set the angle of rotation, it is locked to the frame of the damper head with screw joints 64. The said geometric stop constitutes a locking ring 65 and a locking lug 66. Approximate pressure indicators can also be provided to check whether the damper and gas media are located within predetermined pressure ranges.

The piston rod and the piston rod elements, respectively, are arranged continuously and sealed in two ends or in one end and one wall. The piston rod or piston rod elements are provided with substantially equal cross-sectional areas on both sides of the main piston.

Figure 6 shows the application of a tool 50 which is cooperable with the tool 55 and lugs 51 on the top loop 52. By arranging these tools installed, the separating piston 45 is prevented from shifting to the left in Figure 6 when the oil or the like is filled in the damper under pressure. The oil filling can take place via a channel 46, cf. figure 4.

Figure 4 thus shows how force is applied to push the pressure indicators against lrra fi from internal overpressure of or in the gas container. This thus gives an indication of whether the damper is pressurized and the possibility of estimating the internal overpressure. Figure 5 shows how the oil level 10 15 20 25 30 528 895 10 in the damper can be controlled with a tool. If you want to check the distance L3, this can be done by measuring the distance L2 or in the case shown even more preferably the distance L1. In the latter case, in an exemplary embodiment, the distance L1 must be within the range 1 + 0.5 / -1. This means that the distance becomes easy to control and determine. If the measuring tool is in contact with the container end, oil should be added. Figure 6 shows how positioning of the separating piston can take place, e.g. when filling the damper under pressure under oil.

The cylindrical part of the top loop 15 "extends mainly in a recess arranged in the damping head. In this embodiment, the cylindrical part has a length which is substantially half the length of the total length of the top loop. The recess 15c extends along the essential parts of the cylindrical part which at the top portion projecting outside the damper head has a portion enlarged in the plane which carries said stop surfaces for applicable tool 50. The stop surfaces 51 extend radially outside the cylindrical portion. . The cylindrical portion is resilient at its central parts the space 22.

Said seals for the cylindrical portion arranged on either side of the space 22. Said stop surfaces 51 (figure 6) supporting portion 15a are substantially disc-shaped and have in the direction perpendicular to the plane in e.g. fi guren 6 a thickness which is substantially of the same size as the outer diameter of the tubular part. The rotationally shaped part is symmetrically arranged around the center axis. The part or portion 52 is provided with a recess 52c perpendicular to the plane of the plane, in which a spherically shaped unit 52a and a member 52c formed with a cylindrical outside and spherical inside are arranged. A loading means not shown, e.g. a fastening screw, may extend through a recess in said unit 52a and be fixed in the current movable part on either side of the portion 52. The latter portion is in the plane substantially semicircular.

The directions of rotation of the top loop with respect to the longitudinal axis are shown by arrows 57. The end loop 15 has a corresponding construction with cylindrical part 15d and flat part 15e. The piston rod 8a projects a recess 15f, at which a locking nut 151 is arranged. A recess l5h, sphere l5i and associated outer ring 15k extending perpendicular to the urgur plane in the 2gure plane are arranged to receive an elongate fastening member (not shown) which extends substantially perpendicularly to the urgur plane. The end loop can also assume different rotational positions around the longitudinal axis of the pair of ends and the dimensions and design of the end gloss can be chosen in the same way as the top loop. Through the proposed position, the position of the gas separating piston can be positioned in a simple manner with one or two pressure indicators of the pressure indicators mentioned in the above-mentioned 208 528 895 ll. Because a medium allocated space 22a in the gas separating piston accumulator or container is included in a connecting path for media drying between the piston, i.e. the main piston 7, upper and lower sides 7a, 7b, compare above, no or no extra channels need be provided for establishing the media transport. This in turn entails opportunities to be able to reduce the volume of the damper as such and / or enable a reduced manufacturing cost in the damper. Because the piston rod arrangement is sealed in the damper arrangement by means of only two seals / sealing elements 36a and 37a, the arrangement can operate with an optimally small friction. To date, the use of at least three seals has been required.

In the 7 clock 7 the pair of mandrels 1 is shown in end view from the top loop side, two turning angle positions being indicated by solid and dashed lines 15 'and 1S'. The top loop has in this case been turned an angle oz which is about 40 ”. Furthermore, the positions of the pressure indicators 33, 33 'in relation to the top loop and the adjusting means 38, 38a have been indicated in the clock. In other respects, reference is made to the fi gures described above.

The invention is not limited to the embodiment shown in the above as an example, but may be subjected to modifications within the scope of the appended claims and the idea of invention.

Claims (5)

10 15 20 25 30 528 895 12 PATENT REQUIREMENTS 1. 1. Vehicle shock absorber (shock absorber 1) with optional 61161 OIIISTäÜÜ fl In the case of impact force character which is substantially independent of other internal or external functional factor in the damper and including one with fastening means (15, 15 "), which enables connecting parts to mutually movable parts the vehicle, provided with enclosing, piston and piston rod arrangements (2, 3, 7, 8) which comprise a working member (17), consisting of valves and connections, which in the event of damping force on the piston of the arrangement in its respective direction of movement causes a pressure increase at the piston the side facing the direction of movement while the pressure retainer is present at the side facing the piston fi at the direction of movement, a pressure guaranteeing means (22) at the same time substantially maintains the pressure in the arrangement in the event of pressure-acting parameters striving to change the pressure and the piston rod 8 (piston rod 8). arranged continuously and sealed in two ends (12 "12") or in a gable (37) and a wall in the arrangement by means of two seals / sealing elements (35a, 36a) than indicated by the fact that a gas separating piston (23, 45) included in the pressure-guaranteed member (22) is placed outside the path of movement of the current piston rod or piston rod elements (8, 8b) and is internally sealed with a seal (32) against one of the fastening means (15), which is constituted by a top loop (l5 ”). 2. A damper according to claim 1, characterized in that the top loop (15 ') is separate from the piston rod arrangement (8, 8b). A damper according to claim 2, characterized in that the top loop (15 ') has a sealing part (1a) and a cylindrical part (15b), against the outside of which said seals (3 1, 32 and 32 ") act. Damper according to claim 3, characterized in that a part of the piston rod (8) or the piston rod element (8b) is arranged to be able to run inside a recess (15c) sealed against the damper head (30) in the cylindrical part (15b) in the top loop. (15 ') at the movements of the piston (7). 528 8953 13 Damper according to one of the preceding claims, characterized in that the top loop (15 ') can be rotated about its longitudinal axis (53) and locked in any direction of rotation along the longitudinal axis (53) by means of a container end (63) arranged in connection with the damper head. (30), screwed outwards against a lock (65).