Drive device for moving a closure element of a motor vehicle

Abstract

Provided is a drive device for the movement of a closure element of a motor vehicle relative to a body of the motor vehicle including an outer tube with a longitudinal axis for coupling to the body, an inner element arranged in the outer tube for coupling to the closure element, a helical compression spring arranged between the inner element and the outer tube, and an internal guide element arranged between the inner element and the helical compression spring and axially fixed to the inner element for the internal guidance of an internal guide end section of the helical compression spring. The inner element is extendable along the longitudinal axis from the outer tube. The helical compression spring is compressed against a spring tension of the helical compression spring when the inner element is pulled out of the outer tube.

Claims

1. A drive device for the movement of a closure element, of a motor vehicle relative to a body of the motor vehicle, comprising: a. an outer tube with a longitudinal axis for coupling to the body or to the closure element; b. an inner element arranged at least partially in the outer tube for coupling to the other element of body and closure element; c. a helical compression spring arranged radially to the longitudinal axis between the inner element and the outer tube; and d. an internal guide element arranged radially to the longitudinal axis between the inner element and the helical compression spring and axially fixed to the inner element for internal guidance along the longitudinal axis of an internal guide end section of the helical compression spring; e. wherein the inner element is telescopically extendable from the outer tube along the longitudinal axis; and wherein the helical compression spring is clamped between the inner element and the outer tube in such a way that the helical compression spring is compressed against a spring tension of the helical compression spring during an extension movement of the inner element from the outer tube, wherein f. an external guide element arranged radially to the longitudinal axis between the outer tube and the helical compression spring and axially fixed to the outer tube for external guidance along the longitudinal axis of an external guide end section of the helical compression spring opposite the internal guide end section along the longitudinal axis; g. wherein the external guide end section of the helical compression spring is guided only by the external guide element in at least one state of motion of the inner element relative to the outer tube; and h. wherein the internal guide end section of the helical compression spring is guided only by the internal guide element in said at least one state of motion.

2. The drive device according to claim 1, wherein a. the external guide end section of the helical compression spring is guided only by the external guide element in any state of motion of the inner element relative to the outer tube; and/or b. the internal guide end section of the helical compression spring is guided only by the internal guide element in any state of motion of the inner element relative to the outer tube.

3. The drive device according to claim 1, wherein a guide element length of the external guide element and/or the internal guide element along the longitudinal axis each amount to from 40% to 80%, from 50% to 70%, or from 50% or 60%, of a spring length of the helical compression spring along the longitudinal axis in a state of the inner element retracted maximally in the outer tube along the longitudinal axis.

4. The drive device according to claim 1, wherein in a state of the inner element retracted maximally in the outer tube along the longitudinal axis, a section length of the external guide end section and/or the internal guide end section of the helical compression spring along the longitudinal axis each amounts to from 30% to 70%, from 40% to 60%, or 50%, of a spring length of the helical compression spring along the longitudinal axis.

5. The drive device according to claim 1, wherein a. the inner element is distanced from the external guide end section of the helical compression spring radially to the longitudinal axis with an internal distance in said at least one state of motion, of the inner element relative to the outer tube; and/or b. the outer tube is distanced from the internal guide end section of the helical compression spring radially to the longitudinal axis with an external distance in said at least one state of motion, of the inner element relative to the outer tube.

6. The drive device according to claim 1, wherein a. the external guide end section of the helical compression spring has an external guide clearance to the external guide element radial to the longitudinal axis in said at least one state of motion, of the inner element relative to the outer tube; and/or b. the internal guide end section of the helical compression spring has an internal guide clearance to the internal guide element radial to the longitudinal axis in said at least one state of motion, of the inner element relative to the outer tube.

7. The drive device according to claim 1, wherein a. the external guide element comprises a number of elastic compensating elements, on a side facing the outer tube for biasing against the outer tube and/or for tolerance compensation to the outer tube; and/or b. the internal guide element comprises a number of elastic compensating elements, on a side facing the inner element for biasing against the inner element and/or for tolerance compensation to the inner element.

8. The drive device according to claim 1, wherein a. the internal guide element is substantially cylindrically shaped and/or coaxially arranged to the longitudinal axis; and b. wherein the internal guide element comprises a support element, to support the internal guide end section of the helical compression spring along the longitudinal axis.

9. The drive device according to claim 1, wherein a. the external guide element is essentially hollow cylindrical shaped and/or coaxially arranged to the longitudinal axis; and b. wherein the external guide element comprises a centering element, for centering of the inner element in the external guide element.

10. The drive device according to claim 1, wherein a. the external guide element and/or the internal guide element comprises or consists of a low-friction and/or self-lubricating plastic, a polyoxymethylene, a polycarbonate, or a polytetrafluoroethylene.

11. The drive device according to claim 1, wherein the outer tube and/or the inner element comprises or consists of a metal.

12. The drive device according to claim 1, wherein a. the helical compression spring comprises or consists of a metal; b. wherein the helical compression spring has a plastic flocking; and c. wherein the plastic flocking is impregnated.

13. The drive device according to claim 1, wherein the external guide element and/or the internal guide element has a number of recesses, radial to the longitudinal axis.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows a schematic longitudinal section along the longitudinal axis of a drive device from the conventional art; and

(3) FIG. 2 shows a schematic longitudinal section along the longitudinal axis of a drive device according to embodiments of the invention.

DETAILED DESCRIPTION

(4) FIG. 1 shows a schematic longitudinal section along the longitudinal axis L of a drive device 100 from the conventional art.

(5) The drive device 100 is designed to move a closure element of a motor vehicle relative to a body of the motor vehicle. The drive device 100 comprises an outer tube 110 with a longitudinal axis L for coupling to the body and an inner element 120 partially arranged in the outer tube 110 for coupling to the closure element, for example via an inner connection element 128, in particular a ball socket, attached to one end of the inner element 120.

(6) The outer tube 110 and the inner element 120, for example, are each essentially hollow cylindrical shaped. The outer tube 110 and the inner element 120, for example, are arranged coaxially to the longitudinal axis L.

(7) The drive device 100 comprises a helical compression spring 130 arranged radially to the longitudinal axis L between the inner element 120 and the outer tube 110, and an internal guide element 122 arranged radially to the longitudinal axis L between the inner element 120 and the helical compression spring 130 and axially fixed to the inner element 120 for internal guidance of the helical compression spring 130 along the longitudinal axis L.

(8) The inner element 120 is telescopically extendable along the longitudinal axis L from the outer tube 110, so that the closure element coupled to the inner element 120 is movable relative to the body coupled to the outer tube 110.

(9) The helical compression spring 130 is clamped between the internal guide element 122 and the outertube 120 in such a way that the helical compression spring 130 is compressed against a spring tension of the helical compression spring 130 when the inner element 120 is pulled out of the outer tube 110.

(10) The internal guide element 122 comprises a support element 126, for example a protrusion radially away from the longitudinal axis L, to support the helical compression spring 130 along the longitudinal axis L.

(11) The drive device 100 comprises, for example, an electromechanical drive unit 140 for displacement of the inner element 120 relative to the outer tube 110 along the longitudinal axis. The drive unit 140 may include, in particular, an electric motor and a threaded spindle driven thereby, so that the drive device 100 is a spindle drive according to the paradoxical design.

(12) The drive unit 140 may, for example, be attached to the outer tube 110 opposite the inner coupling element 128 to the outer tube 110 and coupled to the body via an external coupling element 118, for example via another ball socket.

(13) The graph above the drive device 100 shows a schematic course of a speed v of the helical compression spring 130 relative to the internal guide element 122 as a function of a distance x along the longitudinal axis L from the end of the helical compression spring 130 facing the inner coupling element 128, when the inner element 120 is pulled out of the outer tube with a pull-out speed v.sub.1.

(14) At the end of the helical compression spring 130 facing the coupling element 128 (at x=0), the speed v of the helical compression spring 130 corresponds to the pull-out speed v.sub.1. With increasing distance x, the speed v decreases linearly to 0 at the other end of the helical compression spring 130, where the helical compression spring 130 is supported on the support element 126 of the internal guide element 122.

(15) FIG. 2 shows a schematic longitudinal section along the longitudinal axis L of a drive device 100 according to embodiments of the invention.

(16) In contrast to the state of the art shown in FIG. 1, the internal guide element 122 is designed only for the internal guidance of an internal guide end section 132 of the helical compression spring 130.

(17) The drive device 100 shown in FIG. 2 comprises an external guide element 111 arranged radially to the longitudinal axis L between the outer tube 110 and the helical compression spring 130 and axially fixed to the outer tube 110 for external guidance along the longitudinal axis L of an external guide end section 131 of the compression spring 130 opposite the internal guide end section 132 along the longitudinal axis L.

(18) The helical compression spring 130 is clamped between the internal guide element 122 and the external guide element 111 in such a way that the helical compression spring 130 is compressed against a spring tension of the helical compression spring 130 when the inner element 120 is pulled out of the outer tube 110.

(19) The external guide end section 131 of the helical compression spring 130 is supported along the longitudinal axis L on the external guide element 111, in particular on a centering element 117 of the external guide element 111.

(20) The internal guide end section 132 of the helical compression spring 130 is supported along the longitudinal axis L on the internal guide element 122, in particular on a support element 126 of the internal guide element 122.

(21) The external guide end section 131 of the helical compression spring 130 is guided only by the external guide element 111 in at least one state of motion of the inner element 120 relative to the outer tube 110, and the internal guide end section 132 of the helical compression spring 130 is guided only by the internal guide element 122 in said at least one state of motion.

(22) A guide element length of the external guide element 111 and the internal guide element 122 along the longitudinal axis L is, for example, each 50% to 60% of a spring length of the helical compression spring 130 along the longitudinal axis L in a state maximally retracted in the outer tube 110 along the longitudinal axis L as shown in FIG. 2.

(23) As a result, the external guide end section 131, and the internal guide end section 132 of the helical compression spring 130 are each guided only on one side (either inside or outside). A middle section 133 of the helical compression spring 130 between the two end sections 131, 132 may be guided on both sides (outside and inside).

(24) The graph above the drive device 100 shows a schematic course of a speed v of the helical compression spring 130 relative to the internal guide element 122 and external guide element 111 as a function of a distance x along the longitudinal axis L from the end of the helical compression spring 130 facing the inner coupling element 128, when the inner element 120 is pulled out of the outer tube 120 at a pull-out speed v.sub.1.

(25) The speed v is shown as a solid line in sections of the distance x in which the respective guide element 111, 122 guides the helical compression spring 130 and as a dashed line in areas where the respective guide element 111, 122 does not guide the helical compression spring 130.

(26) Only the external guide element 111 guides the external guide end section 131 of the helical compression spring 130 facing the coupling element 128. The speed v is 0 at end of the helical compression spring 130 facing the coupling element 128 (at x=0), where the helical compression spring 130 is supported on the centering element 117 of the internal guide element 122, and increases linearly with increasing distance x to the middle section 133.

(27) The internal guide end section 132 of the helical compression spring 130, which follows on the middle section 133 with increasing distance x, is not guided by the external guide element 111, but by the internal guide element 122. A further increase in the speed v (dashed line) relative to the external guide element 111 with further increasing distance x is therefore irrelevant for the function of the drive device 100.

(28) The relevant speed v (solid line) of the internal guide end section 132 of the helical compression spring 130 relative to the internal guide element 122 decreases linearly as in FIG. 1 with increasing distance x to 0 at the end of the helical compression spring 130, where the helical compression spring 130 is supported on the support element 126 of the internal guide element 122.

(29) The speed v (solid lines) of the helical compression spring 130 relative to the respective guiding guide element 111, 122 relevant for the function of the drive device 100 is thus much lower than the pull-out speed v.sub.1 along the entire helical compression spring 130.

(30) The lower speed v compared to the state of the art leads to reduced wear and noise.

(31) Although the invention has been illustrated and described in greater detail with reference to the preferred exemplary embodiments, the invention is not limited to the examples disclosed, and further variations can be inferred by a person skilled in the art, without departing from the scope of protection of the invention.

(32) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.

(33) TABLE-US-00001 List of reference signs 100 Drive device 110 Outer tube 111 External guide element 117 Centering element 118 External connection element 120 Inner element 122 Internal guide element 126 Support element 128 Inner connection element 130 Helical compression spring 131 External guide end section 132 Internal guide end section 133 Middle section 140 Drive unit L Longitudinal axis v Speed v.sub.1 Pull-out speed x Distance