Main shaft type driving device

Abstract

The invention relates to a spindle drive (10) for motor-driven opening and closing of vehicle flaps or the like, comprising a spindle housing (12) in which a motor transmission unit (18) and a spindle unit (20) are arranged, the spindle unit (20) having a stationary spindle drive and a spindle drive which is axially movable relative thereto, the invention relates to a spindle drive for a motor vehicle, comprising a stationary spindle drive having a spindle (26) which can be driven in rotation by a motor transmission unit (18), and an axially movable spindle drive having a spindle nut (32) which is arranged in a helical engagement on the spindle, the movable spindle drive can be moved axially between a retracted state and a removed state by means of a spindle nut (32) movably arranged on the spindle (26), and wherein a first helical compression spring (44) is provided, which preloads the stationary spindle drive and the movable spindle drive against each other, and a second helical compression spring (44) is provided, which preloads the stationary spindle drive and the movable spindle drive against each other. A second helical compression spring (48) is arranged between the movable spindle drive and the fixed spindle drive in order to support the movable spindle drive when moved from the retracted state into the removed state, and a second helical compression spring (48) is arranged between the movable spindle drive and the fixed spindle drive, the first support part supports the first spiral compression spring (44) in an opening process starting from a retracted state of the movable main shaft type driving part.

Description

Technical Field

[0001] The invention relates to a spindle drive according to the preamble of claim 1 . Background Art

[0002] In order to be able to automatically open and close doors, flaps or hoods of motor vehicles in a controlled manner, preferably a combination of electric drives with passive components, such as gas pressure springs, is used.

[0003] The electric drive usually comprises a spindle drive which usually has an electric spindle drive which acts on the vehicle flap to be moved in order to open and / or close it.

[0004] In order to enable the length of the spindle drive to be changed, the spindle driven by the motor transmission unit is rotated and engaged in the spindle nut. Here, the spindle nut itself is fixed in translation and rotation by the movable spindle drive. The movable spindle drive is guided in the fixed spindle drive so that it can move linearly. The spindle nut is screwed to the spindle, and when the spindle rotates, the spindle nut moves axially between a retracted state and an extended state relative to the fixed spindle drive together with the movable spindle drive connected to the spindle nut.

[0005] The spindle drive is connected with a fixed end to the vehicle and with a movable end to the vehicle flap to be moved, so that the linear movement of the spindle drive is converted into an opening and closing movement of the relevant vehicle flap or vehicle door.

[0006] A spindle drive of the type mentioned at the outset is disclosed in document DE 10 2017 128 391 A1.

[0007] A problem with the known spindle drives is that, for assembly reasons, only a small angle and therefore only a small lever arm is obtained between the vehicle flap and the spindle drive in the closed state of the vehicle flap. This means that at the initial small opening angle of the vehicle flap, a high motor power is required to start the opening movement. During the opening process, the opening angle and therefore the lever arm increase, and only a small part of the initial motor power is required for the further opening process. Therefore, a drive motor of corresponding power is required, which requires more space and leads to higher costs. Summary of the invention

[0008] The object of the invention is to improve the functionality of a spindle drive, in particular at small opening angles of the flap to be driven.

[0009] According to the invention, this object is achieved by a spindle drive having the features of patent claim 1 .

[0010] Preferred embodiments and further advantageous features of the invention are the subject matter of the dependent claims.

[0011] The spindle drive device for motor-driven opening and closing of vehicle hatches, etc. includes a spindle housing, in which a motor transmission unit and a spindle unit are arranged, wherein the spindle unit has a fixed spindle drive part and an axially movable spindle drive part, the fixed spindle drive part has a spindle that can be driven to rotate by the motor transmission unit, and the movable spindle drive part has a spindle nut arranged on the spindle in a spirally engaged manner, wherein the movable spindle drive part can be moved axially between a retracted state and an extended state by a movable spindle nut arranged on the spindle, and wherein a first pressure spring is provided, which preloads the fixed spindle drive part and the movable spindle drive part against each other to support the movable spindle drive part when moving from the retracted state to the extended state.

[0012] According to the invention, a second compression spring is arranged between the movable spindle drive and the fixed spindle drive, which second compression spring supports the first compression spring during an opening process starting from the retracted state of the movable spindle drive.

[0013] The first and second compression springs are both loaded in the fully retracted state of the movable spindle drive. During the opening process of the movable spindle drive, the opening movement is supported by the spring forces of the two compression springs. While the first compression spring supports the entire opening movement, the second compression spring preferably acts only at the beginning of the opening movement within a certain path interval.

[0014] When the vehicle flap is closed and the spindle drive is in the retracted state, the angle between the spindle drive and the flap and thus the lever arm is relatively small, so that the spindle drive can only transmit a small force to the flap. In this state, the spring force of the first spring is supported by the second spring and makes it easier to open the vehicle flap.

[0015] Starting from the retracted state, the second compression spring supports the opening movement of the movable spindle drive at least along an initial section.

[0016] According to a preferred design of the present invention, the second pressure spring is axially arranged between the spindle nut and the spindle support fixed at the fixed spindle drive structure part. The fixed spindle drive part includes a conduit in which the push tube is supported axially. The push tube and the spindle nut fixed at the push tube are part of the movable spindle drive part. The spindle engages in the spindle nut and extends into the interior of the push tube. During the opening movement, the second pressure spring relaxes and releases its stop at the spindle nut in the relaxed state, so that only the force of the first pressure spring still acts on the movable spindle drive part.

[0017] According to a preferred embodiment of the present invention, the second compression spring is arranged in a closed, dust-proof and waterproof cavity. The cavity is bounded by a guide tube, a spindle nut guided in the guide tube, and a seal at the spindle-side end of the guide tube.

[0018] In order to individually adjust the preload force during the initial opening process, the second compression spring can have a different spring constant than the first compression spring.

[0019] In particular, the second compression spring can have a higher spring constant than the first compression spring, so that a greater preload force is present in the retracted state of the spindle drive. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The preferred embodiments of the present invention are described in more detail below with reference to the accompanying drawings, from which further features and advantages of the present invention are derived.

[0021] Figure 1 A section through the spindle drive is shown in the retracted state.

[0022] Figure 2 The section through the spindle drive is shown in the extended state.

[0023] Figure 3 An exploded view of a spindle drive is shown.

[0024] Figure 4 An exploded view of the components of the catheter and push tube is shown. DETAILED DESCRIPTION

[0025] Figure 1 A spindle drive 10 is shown, which is preferably used for motor-driven opening and closing of a vehicle flap (not shown) or the like.

[0026] The spindle drive 10 comprises a spindle housing 12 which extends along a spindle axis 14 and has a first end part 16a which is fastened, for example, to a vehicle body and a second end part 16b which is connected to a vehicle flap to be actuated.

[0027] A motor transmission unit 18 and a spindle unit 20 are arranged in the spindle housing 12 .

[0028] In the embodiment shown, the motor transmission unit 18 is supported in the spindle housing 12 in a rotationally fixed manner via two bearing elements 22 a , 22 b .

[0029] The spindle unit 20 comprises a guide tube 24 in which a spindle 26 is rotatably mounted. The spindle 26 is preferably mounted at its end facing the motor transmission unit 18 by means of a rolling bearing 28 .

[0030] In the embodiment shown, the guide tube 24 is fixed to the spindle housing 12 by means of a holder 46 , for example, is adhesively bonded or welded to the spindle housing.

[0031] A push tube 30 is arranged between the guide tube 24 and the spindle 26, which is coupled to the spindle 26 by means of a spindle nut 32 arranged axially fixedly and non-rotatably at the end of the push tube 30. The spindle nut 32 can preferably be made of plastic, while the push tube 30 is preferably made of metal.

[0032] The spindle 26 is rotatably supported at its free end in the push tube 30 by means of a bearing assembly 34 and is guided axially in the push tube 30. The bearing assembly 34 also serves as an end stop for the spindle nut 32, by which the axial movement of the spindle nut 32 on the spindle 26 is limited, so that the spindle nut 32 cannot move beyond the free end of the spindle 26.

[0033] The motor transmission unit 18 comprises a drive motor 36 having a motor shaft 38 which is rotationally coupled to the spindle 26 via a gear mechanism 40 (not shown in any more detail) and drives the spindle in rotation.

[0034] The other end of the push tube 30 is connected to a housing tube 42 via an end piece 16 b , and the housing tube is guided in the spindle housing 12 .

[0035] If the spindle 26 is rotated by the motor transmission unit 18, the spindle nut 32 and the push tube 30 connected thereto perform a translational movement along the spindle 26 due to the screwed engagement of the spindle nut 32. As a result, the push tube 30 and the housing tube 42 connected thereto are telescopically moved relative to the spindle housing 12 from a retracted state to an extended state. Accordingly, the vehicle flap to be driven is moved, for example, from a closed state to an open state.

[0036] A first helical compression spring 44 is arranged in the intermediate space between the housing tube 42 and the guide tube 24 in order to forcefully support the spindle drive 20 during the extension movement of the push tube 30 and the housing tube 42 .

[0037] The helical compression spring 44 surrounds the guide tube 24 and is supported at one end on a holder 46 for the guide tube 24 and at the other end on the connection between the housing tube 42 and the push tube 30. The length of the first helical compression spring 44 is preferably dimensioned such that it has a force-supporting effect during the entire extension movement of the spindle drive.

[0038] According to the invention, a second helical compression spring 48 is provided, which is arranged in the intermediate space between the spindle 26 and the guide tube 24. In the retracted state of the spindle drive, the rear end of the second helical compression spring 48 is supported on the end side of a holder 50, which in turn bears against the spindle bearing 28, while the front end of the second helical compression spring 48 is supported on the end side of the spindle nut 32. The second helical compression spring 48 is located in a gas-tight sealing area of ​​the spindle drive, into which water or dirt cannot penetrate, so that the corrosion protection of the second spring 48 can be eliminated.

[0039] The second compression spring 48 serves to increase the spring force acting on the movable spindle drive during the opening process. This reduces the current consumption and noise generation of the motor drive unit 18. The length of the second helical compression spring 48 is preferably significantly smaller than the length of the first helical compression spring 44, so that the supporting force effect during the opening process only exists during a limited initial path interval.

[0040] Figure 2 The spindle drive 10 is shown in the extended state. It can be seen that the push tube 30 and the housing tube 42 are in their extended state to the left relative to the fixed guide tube 24 and the spindle housing 12. The first helical compression spring 44 is also in the extended state.

[0041] The second, shorter helical compression spring 48 is in the fully extended, relaxed state and no longer bears against the spindle nut 32 , which has already approached the free end of the spindle 26 and its end stop.

[0042] Figure 3 An exploded view of the basic components of the above-mentioned spindle unfolding device 10 is shown, in particular, the spindle housing 12 and the end parts 16a, 16b, the drive motor 36 and the transmission mechanism 40 arranged in the spindle housing 12, the guide tube 24 and the retainer 46 and the push tube 30 movably supported in the guide tube, the first helical compression spring 44 and the housing tube 42 surrounding the helical compression spring 44.

[0043] Figure 4An exploded view of the basic moving components is shown, in particular, the guide tube 24 and the retainer 46 for fixing it to the inner circumference of the spindle housing 12, the push tube 30 arranged in the guide tube 24 and the integrated spindle nut 32, the second helical pressure spring 48 abutting against the spindle nut 32 at the end side, the retainer 50 for the second helical pressure spring 48, and the spindle 26 engaged in the spindle nut, which extends into the interior of the push tube 30 and is rotatably supported in the spindle housing 12 by means of a rolling bearing 28.

[0044] Reference numerals list

[0045] 10 Spindle drive

[0046] 12 Spindle housing

[0047] 14 Spindle axis

[0048] 16a End piece

[0049] 16b End piece

[0050] 18 Motor drive unit

[0051] 20 Spindle unit

[0052] 22a Support element

[0053] 22b Support element

[0054] 24 Catheter

[0055] 26 Spindle

[0056] 28 Rolling bearing

[0057] 30 Push pipe

[0058] 32 Spindle nut

[0059] 34 Support assembly

[0060] 36 Drive motor

[0061] 38 Motor shaft

[0062] 40 Transmission mechanism

[0063] 42 Shell tube

[0064] 44 First helical compression spring

[0065] 46 Retainer

[0066] 48 Second helical compression spring

[0067] 50 Retainer

Claims

1. A spindle drive device (10) for motor-driven opening and closing of a vehicle hatch or the like, comprising a spindle housing (12) in which a motor transmission unit (18) and a spindle unit (20) are arranged, wherein: The spindle unit (20) comprises a fixed spindle drive and a spindle drive which is axially movable relative to the fixed spindle drive, the fixed spindle drive having a spindle (26) which can be driven to rotate by the motor transmission unit (18), the axially movable spindle drive having a spindle nut (32) which is arranged on the spindle in a spiral connection, wherein the movable spindle drive can be moved axially between a retracted state and an extended state by means of the spindle nut (32) which is movably arranged on the spindle (26), and wherein a first helical pressure spring (44) is provided which preloads the fixed spindle drive and the movable spindle drive relative to each other so as to support the movable spindle drive when moving from the retracted state to the extended state, The invention is characterized in that a second helical compression spring (48) is arranged between the movable spindle drive and the fixed spindle drive, which second helical compression spring supports the first helical compression spring (44) during an opening process starting from the retracted state of the movable spindle drive.

2. The spindle drive device according to claim 1, characterized in that: The second helical compression spring (48) supports the movable spindle drive at least along an initial section starting from the retracted state.

3. The spindle drive device according to claim 1 or 2, characterized in that: The second helical compression spring (48) is arranged axially between the spindle nut (32) and a spindle support (28) fixed to a fixed spindle structure part and is arranged in a push tube (30).

4. The spindle drive device according to any one of claims 1 to 3, characterized in that: The second helical compression spring (48) is arranged in a closed, dust-proof and waterproof cavity.

5. The spindle drive device according to any one of claims 1 to 4, characterized in that: The second helical compression spring (48) has a spring constant that is different from that of the first helical compression spring (44).

6. The spindle drive device according to any one of claims 1 to 5, characterized in that: The second helical compression spring (48) has a greater spring constant than the first helical compression spring (44).

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