EP1591207A1 - Spring tensioner for tensioning a helical compression spring - Google Patents

Abstract

A replacement helical spring (2) forms part of an automotive shock absorber assembly and is presented for re-assembly in a non-tensioned condition. The spring is placed under tension for re-assembly by a compression tool (3) with an integral threaded spindle (4) with two end plates (7, 8) whose position relative to each other is varied by rotation. The plates further incorporated peripheral detents (30, 54) on their inner faces (24, 49) that engage with the spring tips.

Description

The invention relates to an inner tensioner for tensioning a helical compression spring according to the features in the preamble of claim 1.

From the prior art are especially for the automotive sector Internal tensioners for helical compression springs known with which these helical compression springs dismantled from appropriate shots of the chassis and can also be used again.

DE 37 20 018 discloses a generic inner clamp for Helical compression springs, which from a centric within a too exciting helical compression spring positionable and by means of a Clamping drive in its effective length changeable clamping element as well of two axially supported against the clamping element clamping plates to rest on each one spring coil of the helical compression spring. Both clamping plates have a central bore, wherein the drive-side 1. clamping plate in the mounted state with a recess on the Outside supported on a shoulder of the clamping element. The tensioning element includes a threaded spindle in a threaded tube, wherein at a first end the clamping element a drive and at the opposite 2nd end radially outwardly projecting fingers are provided. The on the clamping element on the 2. Radial fingers occupied 2nd clamping plate points of the central bore outgoing, radially outwardly facing recesses on, with the central bore a common, approximately star-shaped Forming opening, so that occupied with radial fingers 2nd end of the clamping element can be passed through the opening formed thereby. Angled offset to the outwardly projecting recesses of the 2. Clamping plates are inserted into the outside of the second clamping plate depressions, in which the radial fingers in the assembled state of the inner tensioner are held positively.

In practical use shows that the assembly of this internal tensioner consuming and in particular the threading of the radial fingers provided 2. End of the clamping element with respect to a series assembly hard to act.

Although the radial fingers and the depressions allow a certain Relativverschwenkung the threaded tube to the 2nd clamping plate. By the in the Principle three-point support of the radial fingers in the wells of the 2nd Spanntellers can however come to a standstill when panning. As a result, a safe tightening a helical compression spring is not fundamental guaranteed.

The spring coils of the helical compression spring are against a radial Slipping from the insides of the clamping plate by on the outer circumference of the Spanner provided ring-shaped collar secured.

This design leads to problems with disassembly for some landing gear and reassembly of a helical compression spring because of the necessary space not available.

The invention is - starting from the prior art - the task underlying, an inner tensioner for tensioning a helical compression spring create a perfect disassembly even with tight mounting spaces and mounting a helical compression spring and Relatiwerschwenkungen between the tensioning drive and by the helical compression spring loaded clamping plates a perfect tensioning of a helical compression spring guaranteed.

This object is achieved with the in the characterizing part of claim 1 solved features.

To problems with tensioning a helical compression spring in the area of To be able to effectively counteract the clamping plate, the invention now provides that both clamping plates on the inner sides facing each other with contact surfaces are provided for spring coils, their slopes in the circumferential direction the clamping plate of the slope of the helical compression spring are aligned. Furthermore, it is important in this context that the footprints to the center axes of the clamping plate through in spring coils are limiting annular beads are limited. This means that the spring coils are not embraced on the outer circumference of the clamping plate provided there collar but only on the inner circumference through the in the spring coils positively engaging annular beads are properly centered. hereby is both the dismantling and assembly even in confined spaces a landing gear. Slippage of the helical compression spring of the Spanntellern is safely prevented.

The invention is both noticeable in an internal tensioner noticeable, in which the tensioning drive from a central threaded spindle, a along the threaded spindle displaceable threaded sleeve and a one Length of the threaded spindle and the threaded sleeve cross Protective sleeve is made, with the protective sleeve with the 1st clamping plate and the free end of the threaded sleeve can be coupled to the 2nd clamping plate, as well in an internal tensioner with a threaded spindle, a pressure piece and a Clamping nut, with a 2nd end of the threaded spindle with the 2nd clamping plate and the pressure piece can be coupled with a 1st clamping plate.

According to the features of claim 2, a 1st clamping plate is circumferentially a central opening for the tensioning drive on the Annular collar facing away from the outside with a spherical segmental dome for engaging a pressure surface adapted thereto on a pressure piece of the Provided clamping drive. In this way, relative pivotal movements between the loaded by the helical compression spring 1st clamping plate and the pressure piece are taken into account.

The displacement of the central axis of the annular bead on the 1st clamping plate to the common central axis of the 1st clamping plate and the central opening in the edge-side recess facing away from the direction (claim 3) has the advantage that in certain installation situations of a helical compression spring the inner tensioner can be considered cheaper.

Due to the adaptation of the footprints on the clamping plates to the Slope of the helical compression spring it is sufficient according to the features of Claim 4, when the marginal segment-like recesses of Spans only extend over an angle of about 90 °. Of the Spring wire of a helical compression spring can thereby easily from the be transferred to the other side of the clamping plate. The the recesses circumferentially bounding surfaces extend in radial planes, at the 1st Spannteller by the central axis of the annular bead and at the 2nd clamping plate run through the center axis.

In development of the invention according to claim 5, the pressure piece by a Clamping nut displaceable on a threaded spindle of the clamping drive.

Between the pressure piece and the clamping nut a thrust bearing is provided, especially in the clamping nut, so no significant Frictional forces between the clamping nut and the pressure piece occur.

After the features of claim 6, a second clamping plate with a Transverse slot provided whose inner end is designed circular segment-shaped, wherein on the side facing away from the annular bead provided a cap is that of ball-shaped inner surfaces of different Size composed of their configuration s.Kugelabschnittsförmige Surfaces are aligned at a 2nd end of the tensioning drive. In this way, a nearly full-surface investment of the 2nd end of the Achieved in the dome calipers in all pivoting positions of the Clamping drive relative to the 2nd clamping plate. The second end forms something like that a pendulum head of the tensioning drive.

A particularly advantageous development of the basic idea according to the invention consists according to the features of claim 7 is that the second end of the tensioning drive spherical and its flat end face on the circumference of straight edges and circular section-shaped Transition edge is limited. From the straight edges on the one hand and the on the other hand, circular-segment-shaped transition edges extend spherical segment-shaped surfaces in the direction of the longitudinal axis of the Tensioning drive. These surfaces are inventively designed so that the Radius of the surfaces between the straight edges and the longitudinal axis greater than the radius of the surfaces between the transition edges and the Longitudinal axis is dimensioned. By contrast, the radius corresponds to all internal surfaces the dome the radius of the surfaces between the straight edges and the longitudinal axis.

It is also advantageous according to claim 8, that in the circumferential direction of the 2. End of the clamping drive measured length of the surfaces with the greater radius about six times the length of the surfaces with the smaller radius corresponds.

A twist-proof embedding of the second end of the tensioning drive in the calotte of the second clamping plate is characterized according to the features of claim 9 scored that the inner surfaces of the dome with straight edges and circular section Transition edges in the dome adjacent to the outside of the second clamping plate open.

According to the features of claim 10 are on a shaft-like Length section of the tensioning drive adjacent the second end two by a Peripheral bead provided separate constrictions. Of the Diameter of these constrictions is smaller than the width of the transverse slot in the 2nd clamping plate. The diameter of the circumferential bead is larger measured as the width of the transverse slot, but smaller than the diameter the circular portion-shaped inner end of the transverse slot. In this way the 2nd clamping plate can easily between two spring coils of Helical compression spring are introduced transversely. Then then the Spannantrieb be displaced in the longitudinal direction of the helical compression spring until that the second end engages in the calotte of the second clamping plate. After that can with Help the tension drive the helical compression spring between the 1st and the 2nd Clamping plate to be clamped.

To allow a fitter, at both ends of the tension drive To be able to apply tools for twisting or countering, see the features of claim 11, that at the 1st end and / or the 2nd end the clamping drive projections are provided with key surfaces.

An expedient design of the clamping drive is ultimately characterized according to claim 12 , that the thickened second end, the constrictions and the peripheral bead are provided directly on the threaded spindle of the clamping drive. The threaded portion of the threaded spindle is provided with a longitudinal groove for receiving a sliding spring as part of the longitudinally displaceable with a clamping nut pressure piece of the clamping drive.

Figur 1

die Einzelteile eines Innenspanners zum Spannen einer Schraubendruckfeder, teilweise in schematischer Perspektive, teilweise in schematischer Ansicht;

Figur 2

eine Frontalansicht auf die Innenseite eines 1. Spanntellers des Innenspanners der Figur 1;

Figur 3

eine Seitenansicht auf den 1. Spannteller der Figur 2 in Richtung des Pfeils III gesehen;

Figur 4

einen vertikalen Querschnitt durch die Darstellung der Figur 2 entlang der Linie IV - IV in Richtung der Pfeile IVa gesehen;

Figur 5

in der Seitenansicht einen Längenabschnitt des Innenspanners der Figur 1 vor der Kopplung mit einem 2. Spannteller;

Figur 6

eine Draufsicht auf die Darstellung der Figur 5 in Richtung des Pfeils VI gesehen, teilweise im Schnitt;

Figur 7

eine Frontalansicht auf die Innenseite des 2. Spanntellers zur Kopplung mit dem Längenabschnitt des Innenspanners der Figuren 5 und 6;

Figur 8

in der Perspektive eine Ansicht auf die Außenseite des 2. Spanntellers und

Figur 9

eine Seitenansicht des 2. Spanntellers in Richtung des Pfeils IX der Figur 7 gesehen.

The invention is explained in more detail with reference to an embodiment shown in the drawings. Show it:

FIG. 1

the items of an internal tensioner for tensioning a helical compression spring, partially in schematic perspective, partially in schematic view;

FIG. 2

a frontal view of the inside of a first clamping plate of the inner tensioner of Figure 1;

FIG. 3

a side view seen on the 1st Spandeller of Figure 2 in the direction of arrow III;

FIG. 4

a vertical cross section through the representation of Figure 2 along the line IV - IV seen in the direction of arrows IVa;

FIG. 5

in the side view of a longitudinal section of the inner tensioner of Figure 1 prior to coupling with a second clamping plate;

FIG. 6

a plan view of the representation of Figure 5 seen in the direction of arrow VI, partly in section;

FIG. 7

a frontal view of the inside of the second clamping plate for coupling with the longitudinal section of the inner clamp of Figures 5 and 6;

FIG. 8

in perspective, a view on the outside of the 2nd clamping plate and

FIG. 9

a side view of the second clamping plate seen in the direction of arrow IX of Figure 7.

With 1 in Figure 1 is generally an internal tensioner for tensioning a helical compression spring 2, for example, for disassembly and assembly a helical compression spring 2 is used, which is part of a Suspension of a motor vehicle forms.

The inner tensioner 1 is composed of a tensioning drive 3 with threaded spindle 4, pressure piece 5 and clamping nut 6, as well as two with the clamping drive. 3 coupled clamping plates 7, 8 together.

The recognizable from Figures 1, 5 and 6 threaded spindle 4 has over the most of their length a threaded portion 9 with a rectangular thread 10 (Figure 6). At a first end 11 of the threaded spindle 4 is a Projection 12 with key surfaces 13 for applying a tool (FIG 1).

The threaded portion 9 is parallel to the longitudinal axis 14 of the Threaded spindle 4 of a longitudinal groove 15 passes through (Figures 1 and 5). The Longitudinal groove 15 is used to engage a sliding spring 16, located in the pressure piece 5 is located (Figure 1). The pressure piece 5 can via the threaded portion. 9 slide. It lies with a ring gear 17 on a thrust bearing, in a sleeve-like length portion 18 of the clamping nut 6 is inserted. The Thrust bearing is not shown in detail. The clamping nut 6 can via key surfaces 19 with the aid of a suitable tool along the threaded portion 9 are relocated.

At the other end, the pressure piece 5 has a spherical segment-shaped Pressure surface 20 for engagement in a correspondingly configured dome 21st on the circumferential side of a central opening 22 in the 1st clamping plate 7 (Figures 1 to 4). The dome 21 opens into the outside 23 of the 1st clamping plate 7. On the inner side 24 facing away from the cap 21 has the 1st Clamping plate 7 an annular bead 25 for engagement in a spring winding 26. Der Annular bead 25 goes over a curved concave throat 27 in a footprint 28 on, the vorsprungslos in the outer periphery 29 of the 1st clamping plate 7 passes. The slope of the footprint 28 is the slope of Adjusted helical compression spring 2.

The edge-side recess 30 on the 1st clamping plate 7 serves for the transfer the spring wire of the helical compression spring 2 from the inside 24 to Outside 23. The common center axis of the 1st clamping plate 7 and the central aperture 22 is denoted by 57. As the figures 2 and 4 Moreover, let the center axis 58 of the annular bead 25 is around the amount x to the common center axis 57 of the 1st clamping plate 7 and the central opening 22 in the edge-side recess 30th offset direction away.

The recess 30 circumferentially bounding surfaces 59th extend in radial planes which the central axis 58 of the annular bead 25th to cut. In the circumferential direction, the recess 30 extends between the Areas 59 over an angle α of 90 °.

The threaded portion 9 of the threaded spindle 4 is according to the particular Figures 1, 5 and 6 in a shaft-like longitudinal section 31 via. This one points a constriction 32, which is followed by a circumferential bead 33. Between the peripheral bead 33 and a thickened second end 34 of the Threaded spindle 4 is another constriction 35. The diameter D of the constrictions 32, 35 is sized equal.

The second end 34 is hemispherical. Its flat end face 36 is bounded on the circumference by straight edges 37 and circular-segment-shaped transition edges 38. From the straight edges 37, spherical segment-shaped surfaces 39 extend in the direction of the longitudinal axis 14 of the threaded spindle 4. Narrow spherical segment-shaped surfaces 40 extend from the circular section-shaped transition edges 38 in the direction of the longitudinal axis 14. The radius R of the surfaces 39 between the straight edges 37 and Longitudinal axis 14 is greater than the radius R _{1 of} the surfaces 40 between the transition edges 38 and the longitudinal axis 14 dimensioned. The length of the surfaces 39 with the larger radius R measured in the circumferential direction of the second end 34 corresponds approximately to six times the length of the surfaces 40 with the smaller radius R ₁ .

Front side of the second end 34 is a projection 41 with key surfaces 42 for Placing a tool provided.

With the thickened second end 34 of the threaded spindle 4 is the second clamping plate. 8 coupled, which is more apparent from Figures 1 and 7 to 9. The second. Clamping plate 8 has a transverse slot 43, the inner end 44 of a circular section is trained. Circumference of the inner end 44 is adjacent the outer side 45 a dome 46 is formed, which is connected to the Configuration of the surfaces 39, 40 of the 2nd end 34 aligned spherical segment-shaped wider inner surfaces 47 and the other hand narrower inner surfaces 48 is equipped. The radius of all inner surfaces 47, 48 of the cap 46 corresponds to the radius R of the surfaces 39 between the straight edges 37 and the longitudinal axis 14 at the second end 34th

Furthermore, Figures 1, 7 and 9 show that the second clamping plate 8 the inner surface 49 facing away from the cap 46 with a footprint 50 for a spring coil 26 of the helical compression spring 2 is provided, the slope in the circumferential direction of the second clamping plate 8 of the pitch of the helical compression spring 2 is aligned. The footprint 50 is to the central axis 51 of the 2nd Clamping plate 8 out through an engaging in a spring coil 26 annular bead 52 limited. The footprint 50 goes without projections in the outer periphery 53 of the second clamping plate 8 over.

The recess 54 in the outer periphery 53 of the second clamping plate 8 serves the Transition of the spring wire of the helical compression spring 2 from the inside 49 the outside 45. It extends over an angle ß of 90 °. The the Recess 54 circumferentially bounding surfaces 60 extend in Radial planes which intersect the central axis 51 of the second clamping plate 8.

The diameter D of the constrictions 32, 35 on the shaft-like longitudinal portion 31 of the threaded spindle 4 is smaller than the width B of the transverse slot 43 in the second clamping plate 8 dimensioned. The diameter D _{1 of} the circumferential bead 33 is greater than the width B of the transverse slot 43, but smaller than the diameter D _{2 of} the circular section-shaped inner end 44 of the transverse slot 43 (Figure 7).

The surfaces 47 of the cap 46 open with straight edges 55 and the Surfaces 48 with circular-section transitional edges 56 in the Outside 45 of the second clamping plate 8 (Figure 8).

For tensioning the helical compression spring 2, first the first clamping plate 7 inserted transversely between two spring coils 26. Subsequently, the Threaded spindle 4 in the longitudinal direction of the helical compression spring 2 through the pushed through the central opening 22 of the 1st clamping plate 7 and then with the Pressure piece 5 and the clamping nut 6 is provided. Then the 2. Clamping plate 8 also between two spring coils 26 of the helical compression spring 2 transversely threaded, wherein the constriction 32 in the transverse slot 43rd summarizes. Thereafter, the threaded spindle 4 can be rotated in the longitudinal direction, wherein the peripheral bead 33 through the inner end 44 of the transverse slot 43rd slides until the 2nd end 43 in the cap 46 of the second clamping plate 8 summarizes. Now, by turning the clamping nut 6, the helical compression spring. 2 between the first clamping plate 7 and the second clamping plate 8 axially tensioned, i. be shortened. By the annular beads 25 and 52 is the helical compression spring 2 securely fixed in position.

REFERENCE NUMBERS

1 -

interior tensioner

2 -

Helical compression spring

3 -

tensioning drive

4 -

screw

5 -

Pressure piece

6 -

locknut

7 -

1st clamping plate

8th -

2. Spannteller

9 -

Thread section v. 4

10 -

square thread

11 -

1st end of v. 4

12 -

Lead at 11

13 -

Wrench flats at 12

14 -

Longitudinal axis v. 4

15 -

Longitudinal groove in 4

16 -

Sliding spring in 5

17 -

Ring wreath at 5

18 -

Length section v. 6

19 -

Wrench flats to 6

20 -

Printing area at 5

21 -

Dome in 7

22 -

Breakthrough in 7

23 -

Outside v. 7

24 -

Inside v. 7

25 -

Ring bulge at 24

26 -

spring coil

27 -

Throat at 7

28 -

Contact patch at 7

29 -

Outer circumference v. 7

30 -

Recess at 7

31 -

Length section v. 4

32 -

Constriction at 31

33 -

Bulge at 31

34 -

2nd end of v. 4

35 -

Constriction at 31

36 -

Front side v. 34

37 -

straight edges

38 -

Transition edges

39 -

Surfaces on 34

40 -

Surfaces on 34

41 -

Lead on 34

42 -

Key surfaces on 41

43 -

Transverse slot in 8

44 -

inner end v. 43

45 -

Outside v. 8th

46 -

Dome in 45

47 -

Inner surfaces v. 46

48 -

Inner surfaces v. 46

49 -

Inside v. 8th

50 -

Contact area at 49

51 -

Central axis v. 8th

52 -

Ring bead on 49

53 -

Outer circumference v. 8th

54 -

Recess at 8

55 -

straight edges v. 47

56 -

Transitional edges v. 48

57 -

Central axis v. 7

58 -

Central axis v. 25

59 -

Areas v. 30

60 -

Areas v. 54

B -

Width v. 43

D -

Diameter v. 32, 35

D1 -

Diameter v. 33

D2 -

Diameter v. 44

R -

Radius v. 39

R1 -

Radius v. 40

α -

Angle between 59

β -

Angle between 60

Claims (12)

Inner tensioner for tensioning a helical compression spring (2), which in particular forms part of a running gear of a motor vehicle, which has a tensioning drive (3) with integrated threaded spindle (4) and two clamping plates (7, 8) which can be displaced relative to one another and which have recesses (30, 54) are provided, characterized in that the clamping plates (7,8) on the mutually facing inner sides (24,49) with the slope of the helical compression spring (2) adapted contact surfaces (28,50) are provided, the vorsprungslos in the outer periphery (29,53) pass over the clamping plate (7,8), however, to the central axes (57,51) of the clamping plate (7,8) are limited by spring coils (26) positively engaging annular beads (25,52). Inner tensioner according to claim 1, characterized in that a 1.Spannteller (7) circumferentially a central opening (22) for the tensioning drive (3) on the annular bead (25) facing away from the outside (23) with a spherical segmental dome (21) for engagement a pressure surface (20) adapted thereto is provided on a pressure piece (5) of the tensioning drive (3). Inner tensioner according to claim 2, characterized in that the central axis (58) of the annular bead (25) on the 1.Spannteller (7) to the common center axis (57) of the 1.Spanntellers (7) and the central opening (22) in the edge-side recess (30) facing away from the direction. Inner tensioner according to one of claims 1 to 3, characterized in that the segment-like recesses (30,54) extend over an angle (α, β) of about 90 °. Inner clamp according to one of claims 2 to 4, characterized in that the pressure piece (5) by a clamping nut (6) on a threaded spindle (4) of the clamping drive (3) is displaceable. Inner tensioner according to one of claims 1 to 5, characterized in that a 2.Spannteller (8) is provided with a transverse slot (43) whose inner end (44) is designed circular section, wherein on the bead (52) facing away from the outside ( 45), a dome (46) is provided which is composed of spherical segment-shaped inner surfaces (47, 48) of different sizes which, in their configuration, are provided on spherical segment-shaped surfaces (39, 40) at a second end (34) of the tensioning drive (3). are aligned. Inner tensioner according to claim 6, characterized in that the second end (34) of the tensioning drive (3) is hemispherical and its flat end face (36) on the periphery of straight edges (37) and circular section-shaped transition edges (38) is limited, from which the spherical segment-shaped surfaces (39, 40) extend in the direction of the longitudinal axis (14) of the tensioning drive (3), the radius (R) of the surfaces (39) between the straight edges (37) and the longitudinal axis (14) being greater than Radius (R1) of the surfaces (40) between the transition edges (38) and the longitudinal axis (14) is dimensioned, and that the radius of the inner surfaces (47,48) of the dome (46) to the radius (R) of the surfaces (39) between the straight edges (37) and the longitudinal axis (14). Inner tensioner according to claim 6 or 7, characterized in that in the circumferential direction of the 2nd end (34) of the tensioning drive (3) measured length of the surfaces (39) with the larger radius (R) about six times the length of the surfaces (40) corresponding to the smaller radius (R1). Inner tensioner according to one of claims 6 to 8, characterized in that the inner surfaces (47,48) of the dome (46) in the 2nd Spannteller (8) with straight edges (55) and circular section-shaped transition edges (56) in the dome (46 ) adjacent outer side (45) of the 2.Spanntellers (8) open. Inner tensioner according to one of claims 6 to 9, characterized in that on a shaft-like longitudinal portion (31) of the tensioning drive (3) adjacent to the second end (34) two by a peripheral bead (33) separated from each other constrictions (32,35) are provided whose diameter (D) is smaller than the width (B) of the transverse slot (43) in the second spider (8), the diameter (D1) of the peripheral bead (33) being greater than the width (B) of the transverse slot (43 ), but smaller than the diameter (D2) of the circular portion-shaped inner end (44) of the transverse slot (43). Inner tensioner according to one of claims 1 to 10, characterized in that on the first end (11) and / or on the second end (34) of the tensioning drive (3) projections (12,41) are provided with key surfaces (13,42) , Inner tensioner according to claim 10 or 11, characterized in that the thickened second end (34), the constrictions (32,35) and the peripheral bead (33) directly to the threaded spindle (4) of the clamping drive (3) are provided and the threaded portion (9) of the threaded spindle (4) with a longitudinal groove (15) for receiving a sliding spring (16) as part of a with a clamping nut (6) along the threaded portion (9) displaceable pressure piece (5) is provided.

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