Spring unit for use in an adjusting device

Abstract

The invention relates to a spring unit for use in an adjusting device for a vehicle flap or vehicle door, comprising a spring element (2) in the form of a helical spring having at least one first spring winding (4). The object of the invention is to provide a spring unit which can be used flexibly in different adjusting devices, in particular spring struts or linear drives for vehicle flaps and vehicle doors, and has low noise generation during operation, which is achieved in that at least one first guide element (8) is arranged on the first spring winding (4) of the spring element (2) for guiding the first spring winding (4) relative to a housing (3) or a spring guide of the adjusting device (20).

Description

[0001] Spring unit for use in an adjustment device

[0002] The invention relates to a spring unit for use in an adjustment device for a vehicle flap or vehicle door, comprising a spring element designed as a coil spring with at least one first spring coil.

[0003] In practice, adjustment devices for vehicle hatches are known that, under normal operating conditions, allow the hatch to be opened and closed between a closed and an open position for vehicle maintenance or for loading and unloading luggage. Besides motor-driven components, such as a motor-driven spindle drive, these drive devices often include at least one mechanical spring unit. This spring unit assists the drive movement and compensates for the hatch's own weight, thus relieving the load on the drive unit's motor. The adjustment device can also be designed as a spring strut, which assists or drives the manual adjustment of the hatch.The spring element used in such spring units is generally designed as a helical compression spring, which is arranged between two telescopically displaceable housing parts. This provides a force between the housing parts and pre-tensions them into the extended position. The diameter of the helical spring increases when compressed, particularly when loaded, and decreases when extended, particularly when unloaded. During compression, the helical spring generally tends to buckle radially. This results in considerable noise due to the spring striking the support elements radially as it buckles. To prevent this, the circumference of the helical spring must be adapted to the existing guide elements within the strut housing.

[0004] DE 10 2005 007 741 A1 discloses an adjusting device designed as a strut, in which a spring element designed as a helical compression spring is used. The helical compression spring has an elastic outer layer, at least on its surface facing radially towards a cylinder wall of the strut. The coating in the form of the elastic outer layer is arranged over the entire surface of the helical compression spring. The elastic outer layer has a flocking, the starting material of which is short-cut fibers, in particular textile or plastic fibers. When applying the flocking, the helical compression spring is first provided with a layer of adhesive.

[0005] The fibers are then injected perpendicularly into the still-uncured adhesive layer using an electrostatic field, following the field lines of the electrostatic field. A disadvantage is the complex coating process required, and the resulting helical compression spring is only designed for a specific installation space and cannot be used flexibly in other adjustment devices with different housing radii.

[0006] FR 2 656 052 A1 shows a spring unit comprising a spring element designed as a helical spring with at least one first coil, wherein an open torus-shaped sleeve is clamped around the coil for noise suppression. The torus-shaped sleeve has a recess in which the first coil is positively engaged.

[0007] DE 10 2018 123 186 A1 shows a spring unit for an adjusting device designed as a spring support, comprising a spring element designed as a coil spring with a first spring coil, wherein a coating is provided on a guide tube to reduce noise generation.

[0008] DE 10 2014 105 624 A1 discloses a spring unit for a spring drive, wherein the spring unit comprises a spring element designed as a helical spring with a first spring coil. The spring element is screwed to coupling elements that are telescopically movable relative to each other via mating screw threads arranged on the coupling elements.

[0009] JP 2002 - 331 837 A shows a spring unit for use in an adjusting device for a vehicle flap or vehicle door, comprising a coil spring, wherein one end of the coil spring is received by a retaining element.

[0010] DE 10 209 838 A1 discloses a torsional vibration damper, in particular for motor vehicles, comprising a helical compression spring with a first spring coil, wherein an arc-shaped sliding shoe is attached to the first spring coil for guidance against a wall.

[0011] The object of the invention is to create a spring unit which can be used flexibly in various adjustment devices, in particular spring struts or linear drives for vehicle flaps and vehicle doors, and which has a low noise level during operation.

[0012] This problem is solved according to the invention by a spring unit having the features of claim 1.

[0013] According to one aspect of the invention, a spring unit, particularly for use in an adjustment device for a vehicle flap or vehicle door, is provided, comprising a spring element designed as a helical spring with at least one first coil. The spring unit according to the invention is characterized in that at least one first guide element is arranged on the first coil of the spring element to guide the first coil relative to a housing or spring guide of the adjustment device. Advantageously, the same spring element can be used in different installation spaces, and the geometry of the guide element arranged on the first coil can be adapted to ensure quiet guidance of the spring element in the housing. The first guide element fills the gap between the coils of the spring element and the housing or spring guide.The spring guide of the adjusting device is designed in such a way as to prevent the spring element from buckling.

[0014] Preferably, the first guide element is positively attached to the first spring coil, in particular by clamping. Advantageously, the first guide element can be easily connected to and detached from the first spring coil. Furthermore, the position of the first guide element can be easily adjusted to the geometric conditions specified by the adjusting device. In addition, the first guide element can be reused at any time.

[0015] In a practical embodiment, the first guide element is designed as a clamping spring. Advantageously, no further fastening means are necessary to connect the first guide element to the first spring coil. It is expedient to simply clamp the first guide element to the first spring coil, whereby the force-fit connection is maintained independently by the first guide element.

[0016] In a preferred embodiment, the first guide element has a receptacle in which the first spring coil is positively engaged. Particularly preferably, the first guide element is designed as a hollow cylinder extending longitudinally along a longitudinal axis with a hollow cylinder wall, wherein the hollow cylinder wall defines the receptacle in which the first spring coil is at least partially engaged.

[0017] In a preferred embodiment, the hollow cylinder wall has a slot extending parallel to the longitudinal axis, the slot being bounded by a first edge extending along the longitudinal axis and a second edge of the hollow cylinder wall opposite the first edge, also extending along the longitudinal axis. The slot forms an opening to the receptacle through which the first spring coil is guided when the first guide element is attached to the first spring coil.

[0018] Advantageously, the first edge of the hollow cylinder wall has a first recess, so that the circumference of the hollow cylinder wall is reduced in the region of the first recess. Advantageously, the second edge of the hollow cylinder wall has a second recess, so that the circumference of the hollow cylinder wall is reduced in the region of the second recess. Particularly preferably, the first and second recesses are arranged opposite each other.

[0019] Preferably, the first recess is essentially U-shaped. Advantageously, the first and second recesses are arranged in a central section of the hollow cylinder wall. The first guide element is advantageously elastic in this central section due to the first and second recesses, allowing it to better follow the curved path of the first spring coil.

[0020] Further advantages, properties, features and further developments of the claimed invention will become apparent from the following description of a preferred embodiment and from the dependent claims.

[0021] The invention is explained in more detail below with reference to the accompanying drawings.

[0022] Fig. 1 shows a preferred embodiment of a spring unit 1 in a cross-sectional view.

[0023] Fig. 2 shows the first guide element 8 in a perspective view.

[0024] Fig. 3 shows the first guide element 8 in a side view.

[0025] Fig. 4 shows the first guide element 8 in a frontal view. Fig. 1 shows a preferred embodiment of a spring unit 1 in a cross-sectional view. The spring unit 1 comprises a spring element 2 designed as a helical compression spring, which is used for preloading within an adjusting device 20 designed as a strut. The spring element 2 is advantageously arranged in a hollow cylindrical housing 3 of the adjusting device 20.

[0026] The spring element 2 has several spring coils 4, 5, 6, 7 which run helically around a central axis M of the spring element 2. A first guide element 8 is clamped to the first spring coil 3. The first guide element 8 essentially serves to provide radial support for the first spring coil 4 during compression of the spring element 2, thus advantageously preventing buckling of the spring element 2.

[0027] The first guide element 8 has a sliding surface 8a facing the housing 3, which is designed such that it generates only low friction upon contact with the housing 3, allowing the first guide element 8 to slide smoothly on the housing 3. In particular, stick-slip effects, i.e., jerky sliding on the housing 3, are effectively prevented, so that the spring element 2 is compressed particularly evenly without buckling.

[0028] A second guide element 9 is clamped to a second spring coil 5, which is adjacent to the first spring coil 4. Advantageously, the second guide element 9 is arranged approximately in the middle of the second spring coil 5, whereas the first guide element 8 is arranged approximately at the beginning of the first spring coil 4. Accordingly, the first guide element 8 and the second guide element 9 are arranged at different angles relative to the central axis M on the spring element 2. This advantageously results in a more regular support of the spring element 2 against the housing 3, thus more effectively preventing buckling of the spring element 2.

[0029] A third guide element 10 is clamped to a third spring coil 6 adjacent to the second spring coil 5, whereby here too the angular position relative to the central axis M differs from that of the first guide element 8 and the second guide element.

[0030] 9. Finally, a fourth guide element 11 is clamped to a fourth spring coil 7 adjacent to the third spring coil 6, whereby here again the angular position relative to the central axis M differs from that of the first guide element 8, the second guide element 9 and the third guide element 10.

[0031] The guide elements 8, 9, 10, 11 can be flexibly arranged at various points on the spring element 2, and their thickness can also be variably adapted to the geometric conditions of the housing 3. For example, it is advantageous to arrange the same spring element 2 in a different housing with a larger inner diameter, whereby the resulting larger radial distance between the spring coils 4, 5, 6, 7 and the housing can be easily compensated for by adjusting the thickness of the guide elements 8, 9, 10, 11. Furthermore, the guide elements 8, 9,

[0032] 10, 11 are also rotated around the spring coils 4, 5, 6, 7 such that these provide radial support against an inner spring guide that runs radially around the spring coils 4, 5, 6, 7. Such an inner spring guide can, for example, be an inner tube that at least partially penetrates the spring element 2. Accordingly, the spring element 2 is internally supported against buckling.

[0033] The guide elements 8, 9, 10, 11 are preferably made of plastic, so that they can be manufactured in large quantities, with good precision, and cost-effectively. Furthermore, the guide elements 8, 9, 10, 11 are advantageously designed to be sufficiently flexible so that they can yield slightly upon contact with the inside of the housing 3, while simultaneously possessing sufficient rigidity to prevent the spring element 2 from buckling.

[0034] In the embodiment shown here, the guide elements 8, 9, 10, 11 are designed as spring clamps, which can be easily clamped onto the spring coils 4, 5, 6, 7 of the spring element 2 and can also be easily released, since there is a force-fit connection between the guide elements 8, 9, 10, 11 and the spring coils 4, 5, 6, 7.

[0035] Fig. 2 shows the first guide element 8 in a perspective view. The first guide element 8 is designed as a spring clamp and has a receptacle 8b into which the first spring coil 4 (see Fig. 1) can be at least partially received. The first guide element 8 is designed as a hollow cylinder, the wall 8c of which has a slot 8d through which the first spring coil 4 can be inserted into the receptacle 8b. The slot 8d extends along a longitudinal axis L of the first guide element 8.

[0036] The hollow cylinder wall 8c has, due to the slot 8d, a first edge 8e extending longitudinally along the longitudinal axis L and a second edge 8f opposite the first edge 8e, also extending longitudinally along the longitudinal axis L. A U-shaped first recess 8g is provided in a central section of the first edge 8e, and a U-shaped second recess 8h is provided in a central section of the second edge 8f. The first recess 8g is arranged opposite the second recess 8h, so that the circumference of the hollow cylinder wall 8c is reduced in the area of ​​the first recess 8g and the second recess 8h. Advantageously, the first guide element 8 is elastically designed in the area of ​​the central section due to the first recess 8g and the second recess 8h, and can thus follow the curved path of the first spring coil 4. Fig. 3 shows the first guide element 8 in a side view.This view shows that the hollow cylinder wall 8c has a reduced outer circumference in the central section 8i due to the first recess 8g and the second recess 8h. It is also particularly evident that the first recess 8g and the second recess 8h are U-shaped and positioned opposite each other. Furthermore, it can be seen that the first recess 8g and the second recess 8h are so deep that they extend beyond the longitudinal axis L of the guide element 8.

[0037] Fig. 4 shows the first guide element 8 in a frontal view. This view shows that the hollow cylinder wall 8c has a uniform wall thickness and is interrupted only by the slot 8d. It can also be seen that the hollow cylinder wall 8c projects beyond the horizontal plane H running through the longitudinal axis L and is also mirror-symmetrical to the vertical plane V running through the longitudinal axis L. Furthermore, it can be seen that the receptacle 8b has essentially an open circular contour. This is because the first spring coil 4 has an essentially circular cross-section.

[0038] The invention has been explained above using an exemplary embodiment in which each spring coil was assigned a guide element. It is understood that two or more guide elements can also be assigned to a single spring coil. This depends essentially on how closely the spring element must be guided in the adjusting device to prevent buckling. Furthermore, it is also possible for individual spring coils to have no guide element, for example, if these spring coils are already sufficiently supported by guide elements present in the adjusting device.

Claims

PATENT CLAIMS 1. Spring unit (1), in particular for use in an adjustment device (20) for a vehicle flap or vehicle door, comprising a spring element (2) designed as a coil spring with at least one first spring coil (4), characterized in that at least one first guide element (8) is arranged on the first spring coil (4) of the spring element (2) for guiding the first spring coil (4) relative to a housing (3) or a spring guide of the adjustment device (20).

2. Spring unit (1 ) according to claim 1 , characterized in that the first guide element (8) is attached to the first spring coil (4) by frictional locking, in particular by clamping.

3. Spring unit (1 ) according to claim 1 or 2, characterized in that the first guide element (8) is designed as a clamping spring.

4. Spring unit (1 ) according to one of the preceding claims, characterized in that the first guide element (8) has a receptacle (8b) in which the first spring coil (4) is received in a force-fit manner.

5. Spring unit (1 ) according to claim 4, characterized in that the first guide element (4) is designed as a hollow cylinder extending longitudinally along a longitudinal axis (L) with a hollow cylinder wall (8c), wherein the hollow cylinder wall (8c) limits the receptacle (8b).

6. Spring unit according to claim 5, characterized in that the hollow cylinder wall (8c) has a slot (8d) extending parallel to the longitudinal axis (L), wherein the slot (8d) is bounded by a first edge (8e) extending along the longitudinal axis (L) and a second edge (8f) of the hollow cylinder wall (8c) extending along the longitudinal axis (L) opposite the first edge (8e).

7. Spring unit according to claim 6, characterized in that the slot (8d) forms an opening to the receptacle (8b) through which the first spring coil (4) is passed when the first guide element (8) is attached to the first spring coil (4).

8. Spring unit according to claim 6 or 7, characterized in that the first edge (8e) of the hollow cylinder wall (8c) has a first recess (8g) such that the circumference of the hollow cylinder wall (8c) is reduced in the area of ​​the first recess (8g).

9. Spring unit according to claim 8, characterized in that the second edge (8f) of the hollow cylinder wall (8c) has a second recess (8h) so that the circumference of the hollow cylinder wall (8c) is reduced in the area of ​​the second recess (8h).

10. Spring unit according to claim 9, characterized in that the first recess (8g) and the second recess (8h) are arranged opposite each other.

11. Spring unit according to one of claims 9 or 10, characterized in that the first recess (8g) is essentially U-shaped.

12. Spring unit according to one of claims 9 to 11, characterized in that the first recess (8g) and the second recess (8h) are located in a central partial section of the hollow cylinder wall (8c) are arranged.

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