GB2039259A

GB2039259A - Resilient strut arrangement for wheel suspensions in motor vehicles

Info

Publication number: GB2039259A
Application number: GB7943631A
Authority: GB
Original assignee: Adam Opel GmbH
Current assignee: Adam Opel GmbH
Priority date: 1978-12-21
Filing date: 1979-12-19
Publication date: 1980-08-06
Also published as: DE2855269B2; FR2444578B1; FR2444578A1; DE2855269C3; DE2855269A1; GB2039259B

Abstract

A suspension strut arrangement for a motor vehicle wheel suspension includes a telescopic damper (16) having a tubular housing (25) with a projecting piston rod (26). The damper housing is normally retained within a tubular carrier (20), but for dismounting purposes can be pivoted laterally through a lateral opening (44) in the carrier, and thereupon withdrawn from the carrier. An associated helical suspension spring (24) extends between an upper spring support plate (33) mounted on the piston rod, and a lower spring support plate (23) secured to the tubular carrier. <IMAGE>

Description

SPECIFICATION Resilient strut arrangement for wheel suspensions in motor vehicles The invention relates to a resilient strut arrange ment for wheel suspensions of motor vehicles consisting of an hydraulic telescopic shock absorber whose housing is fixed in a tubular carrying element extending over the entire length of the housing, and of a helical spring which encloses the piston rod and a part of the carrying element and supports itself on the one hand against a spring plate assigned to the bearerforthe piston rod, and on the other hand against a spring plate secured to the carrying element.

The use of a carrying element for securing the shock absorber housing is one of the most important prerequisites for ensuring that the shock absorber can be dismounted as a closed unit, without relieving the particular wheel of load or, in the event of a defect, can be exchanged for a new shock absorber.

With the shock absorber dismounted the wheel load is transmitted from the carrying element into the vehicle body via the wheel spring.

For the purpose of dismounting the shock absorber from the carrying element, it is known constructthis element as a unilaterally closed tube into which the shock absorber housing is inserted and is firmly clamped by a ring nut at the open end, in the region of the piston rod bearing (see German patent specification 24 35 723).

Also known are constructions in which the carrying element is drawn in near the piston rod bearing, whilst forming a fixed stop, whilst at the other end the carrying element is closed by a screwed plug. In this case, after releasing the screwed plug and freeing the piston rod from its supporting bearing, the shock absorber can be withdrawn at its housing side, from the carrying element (see U.S. patent specification 3 346 272).

The known resilient strut arrangements using a tubular carrying element all have the defect that the shock absorber can only be dismounted in axial direction i.e. in alignment with the resilient strut, whether in one direction or the other.

The removal of the shock absorber at the side of the piston rod support bearing, also presupposes that the support bearing is dismantled, or at least that such a large opening is exposed that a tool for loosening the ring nut holding the shock absorber in the carrying element, can be passed through it, and that the shock absorber can also be withdrawn through it after releasing the nut.

The dismounting of the shock absorber at the side remote from the piston rod is made impossible by the fact that the attachment or connecting parts are provided directly in the axial prolongation of the resilient strut so that access to the carrying element at this side is denied.

If such resilient strut arrangements are used as rectilinear guides for independently suspended, steered wheels of motor vehicles in which the shock absorber is fitted with an upwardly directed piston rod and the carrying element is fixedly connected with the steering knuckle or the wheel carrier, then a downwardly dismounting facility of the shock absorber in the same manner is impossible. This is because other components such as transverse guide arms and even the wheel find themselves in direct prolongation i.e. in the dismounting direction of the resilient strut.

The invention aims at improving after-sales servicing relations by facilitating assembly and dismounting operations with telescopic shock absorbers in resilient strut arrangements having a carrying element of the above-described kind.

According to the invention this problem is solved by arranging that the tubular carrying element is provided with a lateral opening. Besides the facilitated assembly attained, the advantage of this construction is that the shock absorber no longer has to be dismounted solely in the exact axial direction of the resilient leg, but, by suitably proportioning and shaping the lateral opening, the possibility of dismounting over a large sector is offered.

Conversely, the designer is afforded a considerable widening of the shaping possibilities for the resilient strut and the adjacent component parts, if he wishes to realise dismounting facilities without having to relieve the wheel from load.

In an advantageous embodiment of the invention the lateral opening extends over the entire length of the tubular carrying element between an upper and lower clamping point of the shock absorber. Appropriately, the lateral opening is provided at the side of the carrying element remote from the vehicle wheel.

As a rule this is necessary because, for well known reasons the resilient leg has to be arranged as close as possible to the wheel.

According to a further feature of the invention, for the purpose of securing the shock absorber, a fixed stop is provided at the piston-rod-side extremity of the carrying element, and an adjustable stop is provided at the housing-side extremity of the carrying element, whilst the fixed stop is formed preferably by flanging-over or by welding-in a steel ring. In order to attain an axial clamping force of the shock absorber which will remain as constant as possible, according to a further feature of the invention, theadjustable stop is provided with a resilient element.

For dismounting the shock absorber, after releasing the piston rod in its supporting bearing and releasing the adjustable stop in its carrying element, it is only necessary to swing the shock absorber out towards the side at this end, whereupon it can be pulled out from the carrying element.

In order to permit or facilitate the lateral outswinging of the shock absorber from the carrying element or to attain a greater pivoting angle, it is further proposed to provide the piston-rod-side end portion of the tubular carrying element with a bulge at the side of the lateral opening.

In a further configuration of the supporting member according to the invention, this member consists of two parts which are connected together by welding. Here one component piece comprises a half-shell shaped tubular portion extending over its entire length and having a base member at its front end, whilst the other component piece arranged at the piston-rod-side extremity, has an approximately cylindrical dome-shaped portion which is produced in one piece with its appertinent spring plate.

The application of the above-described resilient strut arrangement is particularly of advantage in connection with the rectilinear guiding of independently suspended, steered wheels in which the shock absorber housing - or the tubular carrying element supporting it - is rigidly connected to the steering knockle orto the wheel carrier, and the piston rod of the shock absorber is hingedly supported in a bearer on the vehicle body.

According to a further feature of the invention, for such a rectilinear guide, it is proposed that the adjustable stop at the bottom and of the carrying element should consist of a pressure member, adjustable by means of an axially arranged screw and having a cup-shaped bearing surface upon which the appropriately shaped base part of the shock absorber is seated.

A further advantageous possibility for the releasable attachment of the shock absorber is the formation of the cup-shaped bearing surface by the base piece of the carrying element and by a complementary pressure member which is insertable from the side and is secured to the carrying element by means of two screws.

Further features of the invention will be apparent from the description of several embodiments by way of example, and from the claims.

The embodiments of the invention are illustrated in the drawings and are described below.

In the drawings: Fig. 1 shows a simplified presentation of an independently suspended vehicle wheel using a resilient strut as a rectilinear guiding element, Fig. 2 a section along line ll-ll in Fig. 1, Fig. 3 another embodiment for securing the shock absorber in the base part of the carrying element, Fig. 4 a section along line IV-IV in Fig. 3, Fig. 5 is another embodiment of the formation of the carrying element and its connection with the steering knuckle, and Fig. 6 a section along line VI-VI in Fig. 5.

In Fig. 1, the wheel arch forming a part of a vehicle body 10, is designated by 11. A road wheel 12 is rotatably mounted by means of a hub (not shown) in a bearing boss 13 which in turn forms a part of steering knuckle 14. The steering knuckle 14, and therefore the road wheel 12, are suspended at the vehicle body 10 means of a lower transverse guide arm 15 and a rectilinear guide in the form of a resilient strut 16. In the region of the resilient strut 16, the steering knuckle continues in the form of a tubular component 17 which has a base piece 18 at its lower end, and is completed at its upper end to a tubular carrying element 20 through a sheet-metal pressing 19 connected to it by welding.The sheet-metal part 19 consists of an upper bonnet-shaped end piece 21 with a central aperture 22 and a lower annular flange which serves as a spring plate 23 for the wheel spring 24 in the form of a helical spring. The tubular carrying element 20, formed by the parts 17,18, 19 retains the housing 25 of a hydraulic telescopic shock absorber 27 fitted with an upwardly pointing piston rod 26. The retention is brought about by arranging that the shock absorber housing 25 is firmly clamped axially between the drawn-in edge 28 of the bonnet-shaped part 21 serving as a stop, and the pressure member 30 adjustable by a screw 29 arranged in the base piece 18.

The telescopic shock absorber 27 is supported by its piston rod 26 in a resilient bearing 31 on the vehicle body 10. Between the resilient bearing 31 and piston rod 26 a ball bearing 32 is fitted in order to reduce friction during steering movements. The inner race of this bearing 32 and the upper spring plate 33 of wheel spring 24 are arranged on the reduced-diameter end portion 34 of piston rod 26 and are firmly clamped by a nut against the collar 35.

The resilient bearing 31 in the form of a rubber/metal component, is arranged in an opening 36 provided in the wheel arch 11 and is secured by its outer sheetmetal casing 38, shaped to an annular flange 37, to the vehicle body 10.

Arranged at the underside of the upper spring plate 33 there is a cup-shaped, sheet-metal pressing 39 with an axially corrugated casing. A rubber buffer 41 with an annular bead 42 is snapped into the uppermost of the channels 40 resulting from this profiling.

The upper spring plate 33 is arranged concentrically, but the lower spring plate 23 firmly connected to the carrying element 20, is arranged displaced towards the wheel side in a manner known per se.

A ball joint 43 is provided for the connection of the transverse guide arm 15 to the steering knuckle 14 so that the necessary mobility is ensured between the two parts during in-springing and out-springing of the wheel, as well as for steering-lock turns.

According to the invention, the tubular carrying element 20 is provided with a lateral opening 44 which extends over the entire length of the middle tubular component 17. The result is that, after release of the piston rod 26 from the resilient supporting bearing 31 and after freeing the pressure piece 30, it becomes possible to swing the shock absorber 27 laterally out of the carrying element 20 and withdraw it downwards for the purpose of dismantling (in Fig. 1, see position 59 of shock absorber 27 shown in dotted lines). The prerequisite condition is of course that the shock absorber housing 25 is also fitted in the sheet-metal pressing 19 with so much lateral clearance that it can be tilted with sufficient inclination. The bonnet-shaped part 21 is there.

fore provided with a suitably shaped bulge 45 at the side where the opening 44 is present.

As will be seen from Fig. 2, the edges formed by the opening 44 are each provided with a flange (46a, 46b, respectively directed substantially radially, in order to increase the rigidity of the carrying element 20.

By employing the described arrangement, the dismounting or the exchanging of a telescopic shock absorber 27 in such wheel suspensions is made much more simple and easy. Moreover there is the further advantage that by appropriate arrangement of the side opening, the dismounting plane of shock absorber 27 can readily be so chosen that for example, notwithstanding awkward space conditions, the dismounting may take place in the desired manner for the first time ever, and at least is made considerably easier.

A further possibility of securing the shock absorber housing 25 in the base piece 18' of the carrying element 20' is iliustrated in Fig. 3. Here the base piece 18' is provided with a recess 47 which is open towards the side of the lateral aperture 44 of the carrying element 20', and in which a wedge member 48 with an upright attachment flange 49 is arranged. The attachment is effected by means of two screws 50a, 50b, which are arranged at both sides of the shock absorber housing 25 and are screwed into the elevated cheeks 51 a, 51 b, of the base piece 18'.

Figs. 5 and 6 indicate a possibility whereby the tubular component 17 of the carrier element 20, which in the arrangement according to Fig. 1 is in one piece with the steering knuckle 14, may be in the form of a separate component 17" and be connected to the steering knuckle 13". With this object, two attachment flanges 52 are provided at the bottom end of the separate component 17". In this example, the component 17" having a lateral opening 33", is shaped in cross-section as a half-shell which, for reasons of strength, is formed from two sheet-metal parts 53 and 54 which are arranged spaced from each other and are welded together at their edges and in the middle.In order to connect the carrying element 20" to the steering knuckle 14", the upper end of this latter is constructed as a shoe-shaped arm 55 with which the attachment flanges 52 of the carrying element 20" are firmly joined by means of screws or rivets 56. For the axial fixing of the shock absorber housing 25 and the attainment of the most constant axial clamping force possible, under working load, a dish-shaped spring element 57 is provided above the base part 18" and is displaceably borne by a screw 58.

In the same manner as originally described in connection with the embodiment according to Fig. 1, following the release of the piston rod 26, the shock absorber can be freed from the support bearing 31 after first removing the wedge member 48 (Fig. 3) or releasing the pressure piece 57 (fig. 5). Thus, even with the embodiment according to Figs. 3 and 4 or 5 and 6, the shock absorber can be dismounted in simple manner by swinging its lower end out of the carrying element 20120'/20" and then withdrawing downwards in axial direction. Of course, when installing the shock absorber, one proceeds in the reverse sequence of working steps.

In order to ensure with certainty that lurching of the resilient strut when the shock absorber is dismounted, can be prevented, the upper spring plate 33 is held in position concentric with the support bearing, appropriately by means of a mandrel (not shown).

Claims

1. Resilient strut arrangement for wheel suspensions of motor vehicles consisting of an hydraulic telescopic shock absorber whose housing is fixed in a tubular carrying element extending over the entire length of the housing, and of a helical spring which encloses the piston rod and a part of the carrying element and supports itself on the one hand against a spring plate assigned to the bearer for the piston rod, and on the other hand against a spring plate secured to the carrying element, characterised in that the tubular carrying element (20) is provided with a lateral opening (44) for the purpose of dismantling the shock absorber (27).

2. Resilient strut arrangement in accordance with claim 1, characterised in that the lateral opening (44) is provided between an upper and a lower clamping point of the shock absorber (27).

3. Resilient strut arrangement in accordance with claim 1 and 2, characterised in that the lateral opening (44) is provided at the side of the carrying element (20) remote from the vehicle wheel (12).

4. Resilient strut arrangement in accordance with claim 1 and 2, characterised in that, for retaining the shock absorber (27), a fixed stop is provided at the piston-rod-side extremity of the carrying element (20), and an adjustable stop (30, 48, 57) is provided at the housing-side extremity of the carrying element (20).

5. Resilient strut arrangement in accordance with claim 4, characterised in that the fixed stop is formed by flanging-over the tubular carrying element (20).

6. Resilient strut arrangement with claim 4, characterised in that the fixed stop is formed by welding a steel ring into the upper end of the tubular carrying element (20).

7. Resilient strut arrangement in accordance with claim 4, characterised in that the adjustable stop (30, 48, 57) is provided with a resilient element (57).

8. Resilient strut arrangement in accordance with claim 1 and 2, characterised in that at the piston-rod side, the tubular carrying element (20) is formed by a bonnet-shaped end piece (21), and that towards the side of the lateral opening (44), a carrying element (20) is provided with a bulge (45).

9. Resilient strut arrangement in accordance with claim 1 and 2, characterised in that the carrying element (20) provided with a lateral opening (44), consists of a tubular part (17) frontally closed at the end remote from the piston rod (26) but laterally open and of half-shell shape over the entire length, and of a substantially cylindrical sheet-metal part (19) produced in one piece with the appertinent spring plate (23), and that both parts are connected together by welding.

10. Resilient strut arrangement in accordance with one or more of the foregoing claims, particularly for the alignment of independently suspended, steered wheels of motor vehicles, wherein the tubular element carrying the shock absorber is firmly connected to the steering knuckle or to the wheel carrier, and the piston rod of the shock absorber is hingedly supported at the vehicle superstructure or the like, characterised in that the adjustable stop at the bottom end of the carrying element (20) consists of a pressure member, (30) adjustable by means of an axially arranged screw (29) and having a cup shaped bearing surface upon which the appropri ately shaped base part of the shock absorber (27) is seated (Fig. 1).

11. Resilient strut arrangement particularly in accordance with claim 2 and 10, characterised in that a cup-shaped bearing surface for the appropriately shaped base part of the shock absorber housing (25), is partially formed by the base piece (18') of the carrying element (20) and partially by a complementary wedge piece (48) secured to the side (Figs. 3 and 4).

12. Resilient strut arrangement in accordance with claim 1 and 10, characterised in that with the object of stiffening, the edges (46a, 46b) of the lateral opening (44) of the carrying element (20) are bent over outwards (Fig. 2).

13. Resilient strut arrangement in accordance with claim 10, characterised in that the tubular carrying element (20) is made in one piece with the steering knuckle (14) or with the wheel carrier (13).

14. Resilient strut arrangement in accordance with claim 13, characterisedin that the component consisting of the steering knuckle or the wheel carrier (13), is made of cast aluminium.

15. Resilient strut arrangement in accordance with claim 13 characterised in that the component consisting of the steering knuckle (14) or the wheel carrier (13) is made of spheroidal graphite cast iron.

16. Resilient strut arrangement in accordance with claim 10, characterised in that the tubular carrying element (20) provided with a lateral opening (44), takes the form of a U-shaped profile produced from two channel-shaped sheet-metal pressings, whilst these sheet-metal pressings are welded together at their edges and in the middle, and the carrying element (20) is provided at its lower end with a shoe (55) by which it is secured to the steering knuckle (14) or the wheel carrier (Figs. and 6).

17. Resilient strut arrangement for wheel suspensions of motor vehicles, substantially as hereinbefore particularly described and as shown in Figures 1 and 2 of the accompanying drawings.

18. Resilient strut arrangement for wheel suspensions of motor vehicles, substantially as hereinbefore particularly described and as shown in Figures 3 and 4 of the accompanying drawings.

19. Resilient strut arrangement for wheel suspensions of motor vehicles, substantially as hereinbefore particularly described and as shown in Figures 5 and 6 of the accompanying drawings.