An electric tailgate strut for a vehicle

Abstract

The present invention discloses an electric tailgate strut for an automobile, which includes an outer tube, an inner tube and a bushing. A first ball head assembly is provided at the first end of the outer tube. A driving device is arranged in the inner cavity of the first end of the outer tube. The circuit components of the driving device extend out of the exterior through the first ball head assembly. The power output end of the driving device is connected to the first end of a lead screw. The first end of the lead screw is also connected to a rotating component. The bushing is arranged on the inner wall of the outer tube, and the first end and the second end of the bushing respectively correspond to the rotating component and the second end of the outer tube. A lead screw nut is spirally sleeved on the lead screw. The second end of the lead screw nut is connected to a second ball head assembly. The inner tube is slidably arranged on the inner wall of the bushing, and the second end of the inner tube is connected to the second ball head assembly. An elastic component is arranged between the inner tube and the lead screw nut.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive tailgate struts, and particularly to an electric tailgate strut for automobiles. Background Art

[0002] Traditionally, the opening of an automotive tailgate is manually opened by the driver or passenger after unlocking, which is achieved by a pneumatic strut or a four-link hinge or a gooseneck tube hinge in cooperation with a torsion bar spring. In existing domestic automobiles, generally a pneumatic strut or a four-link hinge or a gooseneck tube hinge in cooperation with a torsion bar spring is used, and only higher-specification vehicles use an electric tailgate, which is achieved by an electric strut.

[0003] Most electric struts include an outer tube and an inner tube that slides in cooperation with the outer tube. A transmission mechanism for driving the inner tube to slide axially along it is provided inside the outer tube, and a motor for driving the transmission mechanism is provided at the bottom of the outer tube. In order to reduce the noise generated during the telescopic process of the inner tube, a bushing is provided between the inner tube and the outer tube.

[0004] The current electric struts have the following problems:

[0005] 1. The structure is unreasonable, which is not conducive to assembly and use, and reduces the assembly efficiency.

[0006] 2. There are two types of bushings between the inner tube and the outer tube: one is a split type, which is composed of two semi-tubular parts. The bushing composed of two tubular parts is fixedly installed on the inner wall of the outer tube through a fixing member. The advantage of adopting this structure is that the dimensional accuracy requirements for single parts are not high. After being assembled into the assembly, the product function will not be reduced or invalidated due to changes in ambient temperature. However, there are the following deficiencies: 1). There are many types of parts, many molds are required, and they need to be produced separately, resulting in high costs and low efficiency. 2). The assembly of the bushing during the assembly process of the electric strut is relatively troublesome, resulting in low work efficiency. The other is a full-circumference integral type. This structure overcomes the deficiencies of the above split type structure, but has high requirements for the machining accuracy of parts. If there is a slight deviation in the product, it is easy to cause a reduction or invalidation of the product function.

[0007] 3. There are ball seats at both ends of the electric strut for fixing to the automotive tailgate and the vehicle body. One end where the internal motor of the electric strut needs to lead out a wire harness to connect to the vehicle body is the wire harness ball seat. In order to prevent the motor from getting water, a sealing structure needs to be designed between the wire harness ball seat and the wire harness rubber sleeve that wraps the wire. The existing sealing structures are all that the wire harness rubber sleeve simply wraps the wire outlet pipe of the ball seat, and the sealing grade is relatively low, which cannot meet the test requirements of being immersed in water for 1 meter for 1 hour, and the reliability is relatively low.

[0008] 4. Most electric struts include an outer tube and an inner tube that slides in cooperation with the outer tube. A transmission mechanism for driving the inner tube to slide axially along it is provided inside the outer tube, and a motor for driving the transmission mechanism is provided at the bottom of the outer tube. To prevent the motor from getting water in and ensure the reliability and durability of the product, a sealing structure is usually configured for the lead screw and the bearing. In the prior art, the lead screw and the bearing are simply wrapped and sealed by an umbrella-shaped sealing ring. There are a lead screw retaining ring and a ball bearing on the lead screw and the bearing, and the sealing reliability is slightly poor. Summary of the Invention

[0009] The purpose of the present invention is to provide an electric strut for a vehicle tailgate to solve the above problems in view of the above-mentioned deficiencies and defects of the prior art.

[0010] The technical problems solved by the present invention can be realized by adopting the following technical solutions:

[0011] An electric strut for a vehicle tailgate, characterized in that it includes an outer tube, an inner tube and a bushing. A first ball head assembly is provided at the first end of the outer tube. A driving device is provided in the inner cavity at the first end of the outer tube. The circuit components of the driving device extend out of the external through the first ball head assembly. The power output end of the driving device is connected to the first end of a lead screw. The first end of the lead screw is also connected to a rotating member. The bushing is arranged on the inner wall of the outer tube, and the first end and the second end of the bushing respectively correspond to the rotating member and the second end of the outer tube. A lead screw nut is spirally sleeved on the lead screw. The second end of the lead screw nut is connected to a second ball head assembly. The inner tube is slidably arranged on the inner wall of the bushing, and the second end of the inner tube is connected to the second ball head assembly. An elastic member is arranged between the inner tube and the lead screw nut.

[0012] In a preferred embodiment of the present invention, the driving device includes a reduction motor, and the rotating member includes a bearing cooperating with the lead screw, a shaft sleeve and a bearing seat cooperating with the bearing.

[0013] In a preferred embodiment of the present invention, a sealing member is arranged between the bearing and the inner convex ring of the bearing seat. The outer peripheral surface of the sealing member is an annular groove and the annular groove cooperates with the inner convex ring of the bearing seat. The inner peripheral surface of the sealing member is a V-shaped groove and the V-shaped groove is in contact and cooperation with the shaft sleeve.

[0014] In a preferred embodiment of the present invention, a plurality of strip-shaped grooves parallel to the axis direction of the bushing are circumferentially and spacedly arranged on the outer peripheral surface of the bushing. The second end of the bushing is an open end, and the strip-shaped grooves are closed at the end positions of the second end to form a second elastic structure. A positioning ring is arranged on the inner peripheral surface of the first end of the bushing body, and the strip-shaped grooves are through groove structures at the end positions of the first end. The positioning ring includes a plurality of arc segments, and adjacent arc segments are connected by a first elastic structure. The plurality of arc segments are fixedly connected to the inner peripheral surface of the first end of the bushing body.

[0015] In a preferred embodiment of the present invention, a bayonet structure for cooperating with the bearing seat of the electric strut is arranged on each arc segment.

[0016] In a preferred embodiment of the present invention, a positioning portion extending towards the middle of the bushing for radially limiting the elastic member is further arranged at the inner end of each arc segment.

[0017] In a preferred embodiment of the present invention, each first elastic structure corresponds to each through groove structure.

[0018] In a preferred embodiment of the present invention, the outer end surface height of the positioning ring is lower than the height of the first end of the bushing, so that a limiting step structure is formed between the outer end surface of the positioning ring and the inner end surface of the first end of the bushing for limiting the sealing member to prevent the radial displacement of the sealing member.

[0019] In a preferred embodiment of the present invention, the first elastic structure is a first arc-shaped connecting edge integrally formed with the bushing body, and the second elastic structure is a second arc-shaped connecting edge integrally formed with the arc segment.

[0020] In a preferred embodiment of the present invention, the first ball head assembly includes a wire harness ball seat. A passage hole for facilitating the penetration of the seal is arranged on the wire harness ball seat. One end of the seal cooperates with the passage hole, and the end of the seal is a flanging portion. The flanging portion fits with the first step on the wire harness ball seat. A fixing plate for fixing the seal is further arranged on the wire harness ball seat. The fixing plate fits on the first step and the second step, and the fixing plate is connected to the wire harness ball seat through a connecting member.

[0021] Due to the adoption of the above technical solutions, the present invention has the following advantages:

[0022] 1. The structure is reasonable and convenient for assembly.

[0023] 2. Strip-shaped grooves are provided on the bushing, which is divided into two parts or more parts. The first and second elastic structures are used to connect each part into a whole. Therefore, the bushing still remains as a whole, and at the same time, it has a certain amount of deformation adjustment. The requirement for the dimensional accuracy of the parts is greatly reduced, and the manufacturability of the parts is improved.

[0024] 3. The first ball head component has a high sealing level, can meet the test requirements of being immersed in water at a depth of 1 meter for 1 hour, and has high reliability.

[0025] 4. Through the special structure of the sealing component, the sealing of the bearing is achieved. The V-shaped groove of the sealing component tightly wraps the shaft sleeve, achieving a reliable double-sealing structure effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is an exploded view of the structure of an embodiment of the present invention.

[0028] Figure 2 It is Figure 1 A schematic diagram of the assembled structure.

[0029] Figure 3 It is Figure 2 A cross-sectional view of

[0030] Figure 4 It is Figure 3 An enlarged view of part I of

[0031] Figure 5 It is Figure 3 An enlarged view of part II of

[0032] Figure 6 It is a schematic diagram of the structure of a bushing of an embodiment of the present invention.

[0033] Figure 7 It is Figure 6 An enlarged view of a part of

[0034] Figure 8 It is a schematic diagram of the structure of a bushing of an embodiment of the present invention.

[0035] Figure 9 It is Figure 8 An enlarged view of a part of

[0036] Figure 10 A schematic diagram of the structure of a sealing component of an embodiment of the present invention.

[0037] Figure 11 It is Figure 10 A schematic diagram of the usage state of

[0038] Figure 12 It is an exploded view of the structure of the first ball head assembly of an embodiment of the present invention.

[0039] Figure 13 It is Figure 12 an assembly drawing.

[0040] Figure 14 It is Figure 13 a schematic sectional view of the assembly.

[0041] Figure 15 It is Figure 13 the front view.

[0042] Figure 16 It is Figure 15 the A-A sectional view.

[0043] Figure 17 It is Figure 15 the B-B sectional view.

[0044] Figure 18 It is a three-dimensional view of the first ball head assembly of an embodiment of the present invention.

[0045] Figure 19 It is another three-dimensional view of the first ball head assembly of an embodiment of the present invention. Specific embodiments

[0046] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below.

[0047] Refer to Figures 1 to 5 a kind of electric strut for automobile tailgate shown in the figure, which includes an outer tube 100, an inner tube 200 and a bushing 300. A first ball head assembly 400 is provided at the first end of the outer tube 100. Combining Figures 12 to 19 shown in the figure, the first ball head assembly 400 in this embodiment includes a wire harness ball seat 410 and a first ball head 470. The wire harness ball seat 410 is connected to the outer tube 100 by riveting, and then a wire end sleeve 420 is sleeved. A passage hole 430 is provided on the wire harness ball seat 410, and the passage hole 430 facilitates the penetration of the seal 440, so that the wire 1 and the seal 440 can be stuffed into the wire harness ball seat 410 and smoothed out.

[0048] One end of the seal 440 is matched with the passage hole 430, and the end of the seal 440 is a flanging part 441. The flanging part 441 fits with the first step 411 on the wire harness ball seat 410. The seal 440 is preferably a wire harness rubber sleeve.

[0049] A fixing plate 450 is further provided on the wire harness ball seat 410. The fixing plate 450 is used to fix the seal 440, and the fixing plate 450 can make the seal 440 fit with the wire harness ball seat 410. The fixing plate 440 fits on the first step 411 and the second step 412, and the fixing plate 440 is connected to the wire harness ball seat 410 through a connecting member 451. The connecting member 451 is preferably a self-tapping screw, and under the action of the self-tapping screw, the fixing plate 450 can be fastened to the wire harness ball seat 410. One end of the wire harness ball seat 410 is provided with a damping gasket 460 for the motor to be sleeved in.

[0050] During assembly, the wire 1 and the seal 440 are inserted into the aisle hole 430 of the wire harness ball seat 410 and smoothed out, so that the flanging part 441 at the end of the seal 440 fits with the first step 411 of the wire harness ball seat 410. Then, the fixing plate 450 is sleeved on the seal 440 so that the fixing plate 450 fits with the flanging part 441 of the seal 440. Finally, the fixing plate 450 and the wire harness ball seat 410 are fastened together by the connecting member 451, so that the flanging part 441 of the seal 440 and the first step 411 and the second step 412 of the wire harness ball seat 410 are pressed by the fixing plate 450, realizing reliable sealing of the motor wire harness.

[0051] The second end of the outer tube 100 is provided with an intermediate sleeve 19 to prevent external dust or debris from entering the bushing 300. The inner cavity of the first end of the outer tube 100 is provided with a driving device 900. The circuit components of the driving device 900 extend out through the first ball head assembly 400. The power output end of the driving device 900 is connected to the first end 610 of the lead screw 600, and the first end of the lead screw 610 is also connected to a rotating member. The bushing 300 is arranged on the inner wall of the outer tube 100, and the first end and the second end of the bushing 300 correspond to the rotating member and the second end of the outer tube 100 respectively. A lead screw nut 700 is spirally sleeved on the lead screw 600. A lead screw ring 17 and an O-ring 18 are arranged at the end of the lead screw 600. The second end of the lead screw nut 700 is connected to the second ball head assembly 500. The inner tube 200 is slidably arranged on the inner wall of the bushing 300, and the second end of the inner tube 200 is connected to the second ball head assembly 500 by riveting, and then a universal sleeve 21 is sleeved. An elastic member 800 is arranged between the inner tube 200 and the lead screw nut 700. The elastic member 800 is a spring. One end of the spring is connected to the flat washer 20 on the inner wall of the first end of the bushing 300, and the other end is connected to the second ball head assembly 500.

[0052] In this embodiment, the driving device 900 includes a reduction motor. The rotating components include a bearing 10 and a bushing 16 that cooperate with the lead screw 600, and a bearing housing 11 that cooperates with the bearing 10. Specifically, the output end of the reduction motor is connected to one end of the lead screw 600 through a spline. The bearing 16 is assembled on the bearing housing 11. A sealing ring 14 is provided between the bearing housing 11 and the outer tube 100. A special retaining ring 12 and a baffle 13 are also provided between the bearing 10 and the reduction motor, and the lead screw 600 passes through them. The bearing housing 11 and the outer tube 100 are connected by press riveting.

[0053] A sealing component 15 is provided between the bearing 10 and the inner convex ring 11a of the bearing housing 11. Combining Figure 10 and 11 as shown, the outer peripheral surface of the sealing component 15 is an annular groove 15a and the annular groove 15a cooperates with the inner convex ring 11a of the bearing housing 11. The inner peripheral surface of the sealing component 15 is a V-shaped groove 15b and the V-shaped groove 15b is in contact and cooperation with the bushing 16. The sealing component 15 is made of rubber material. The bushing 16 and the lead screw 600 are in interference fit, equivalent to an integral structure, so that there is no problem with the sealing effect between the bushing 16 and the lead screw 600. A certain amount of lubricant can also be coated or stored in the V-shaped groove 15b, which not only ensures the sealing effect with the bushing 16, but also makes the rotational movement of the lead screw 600 smooth, improving the durable working performance of the product.

[0054] Combining Figure 6 and Figure 7 as shown, a bushing 300 is provided between the outer tube 100 and the inner tube 200. A plurality of strip-shaped grooves 310 parallel to the axis direction of the bushing are circumferentially spaced on the outer peripheral surface of the bushing 300. In this embodiment, there are two strip-shaped grooves, symmetrically arranged on the outer peripheral surface of the bushing 300.

[0055] The second end of the bushing 300 is an open end 302, and the strip-shaped grooves 310 are closed at the end of the second end to form a second elastic structure 320. A positioning ring 330 is provided on the inner peripheral surface of the first end of the bushing 300, and the strip-shaped grooves 310 are through groove structures 311 at the end of the first end. Since one end of the strip-shaped groove 310 is a closed structure and the other end is a through groove structure, the whole bushing has a certain amount of deformation adjustment for expansion or contraction in diameter, greatly reducing the requirement for the dimensional accuracy of the parts and improving the manufacturability of the parts. The positioning ring 330 includes a plurality of arc segments 331, and adjacent arc segments 331 are connected by a first elastic structure 332. The plurality of arc segments 331 are fixedly connected to the inner peripheral surface of the first end of the bushing. In this embodiment, the second elastic structure 320 is a second arc-shaped connecting edge integrally formed with the bushing, and the first elastic structure 332 is a first arc-shaped connecting edge integrally formed with the arc segment 331.

[0056] In each arc segment 331 of this embodiment, a bayonet structure 331a that mates with the bearing housing 11 is provided, and the limiting portion of the bearing housing 11 of the bearing assembly can be snap-fitted with the bayonet structure 331a.

[0057] At the inner end of each arc segment 331 in this embodiment, a positioning portion 331c extending towards the middle of the bushing is further provided for radially limiting the elastic member 800.

[0058] In this embodiment, each first elastic structure 332 corresponds to each through slot structure 311. The through slot structure 311 provides a space for the first elastic structure 332, so that the first elastic structure 332 does not protrude from the outer surface of the bushing in the radial direction of the bushing, and does not increase the outer diameter size of the entire bushing.

[0059] The height of the outer end face 331b of the positioning ring 330 is lower than the height of the first end of the bushing, so that a limiting step structure is formed between the outer end face 331b of the positioning ring 330 and the inner end face 301 of the first end of the bushing for limiting the sealing member 15 to prevent the sealing member 15 from radially shifting.

[0060] On the outer peripheral surface of the second end of the bushing 300, a plurality of guiding inclined surfaces 340 and concave portions 341 are provided. The guiding inclined surfaces 340 facilitate the bushing to slide into the inner wall of the outer tube, and the concave portions 341 facilitate the inner wall limiting of the end of the bushing.

[0061] At the second end of the bushing 300, a plurality of notch structures 350 that cooperate with the outer tube cap feet of the electric strut are circumferentially spaced, facilitating alignment.

[0062] Of course, the bushing can also be other similar structures. For example, as shown in Figure 8 and Figure 9 The strip-shaped grooves of the bushing are three 310’, circumferentially spaced on the outer peripheral surface of the bushing. The included angle between two adjacent strip-shaped grooves and the axis of the bushing is 330°. The second elastic structure 320’ is the first trapezoidal connecting edge integrally formed with the bushing, and the first elastic structure is the first arc-shaped connecting edge integrally formed with the arc segment. Other structures of this bushing are the same as those of the above embodiment.

[0063] The foregoing shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An electric strut for a vehicle tailgate, characterized in that, It includes an outer tube, an inner tube and a bushing. A first ball head assembly is provided at the first end of the outer tube. A driving device is provided in the inner cavity of the first end of the outer tube. The circuit components of the driving device extend out of the exterior through the first ball head assembly. The power output end of the driving device is connected to the first end of a lead screw. The first end of the lead screw is also connected to a rotating component. The bushing is arranged on the inner wall of the outer tube, and the first end and the second end of the bushing respectively correspond to the rotating component and the second end of the outer tube. A lead screw nut is spirally sleeved on the lead screw. The second end of the lead screw nut is connected to a second ball head assembly. The inner tube is slidably arranged on the inner wall of the bushing, and the second end of the inner tube is connected to the second ball head assembly. An elastic component is arranged between the inner tube and the lead screw nut; A plurality of strip-shaped grooves parallel to the axis direction of the bushing are circumferentially and spacedly arranged on the outer peripheral surface of the bushing. The second end of the bushing is an open end, and the strip-shaped grooves are closed at the end positions of the second end to form a second elastic structure. The bushing has a bushing body. A positioning ring is arranged on the inner peripheral surface of the first end of the bushing body, and the strip-shaped grooves are through groove structures at the end positions of the first end. The positioning ring includes a plurality of arc segments. The adjacent arc segments are connected by a first elastic structure. The plurality of arc segments are fixedly connected to the inner peripheral surface of the first end of the bushing body; The driving device includes a reduction motor. The rotating component includes a bearing, a bushing sleeve cooperating with the lead screw and a bearing seat cooperating with the bearing; A bayonet structure cooperating with the bearing seat of the electric strut is arranged on each arc segment.

2. The electric strut for a vehicle tailgate according to claim 1, wherein A sealing component is arranged between the bearing and the inner convex ring of the bearing seat. The outer peripheral surface of the sealing component is an annular groove and the annular groove cooperates with the inner convex ring of the bearing seat. The inner peripheral surface of the sealing component is a V-shaped groove and the V-shaped groove is in contact and cooperation with the bushing sleeve.

3. The electric strut for a vehicle tailgate according to claim 1, wherein, A positioning portion extending towards the middle of the bushing is further arranged at the inner end of each arc segment for radially limiting the elastic component.

4. The electric strut for a vehicle tailgate according to claim 1, wherein Each first elastic structure corresponds to each through groove structure.

5. The electric strut for a vehicle tailgate according to claim 1, wherein The outer end surface height of the positioning ring is lower than the height of the first end of the bushing, so that a limiting step structure is formed between the outer end surface of the positioning ring and the inner end surface of the first end of the bushing for limiting the sealing component to prevent the radial displacement of the sealing component.

6. The electric strut for a vehicle tailgate according to claim 1, wherein, The first elastic structure is a first arc-shaped connecting edge integrally formed with the bushing body, and the second elastic structure is a second arc-shaped connecting edge integrally formed with the arc segment.

7. The electric tailgate strut according to claim 1, characterized in that, The first ball head assembly includes a wire harness ball seat. A passage hole facilitating the penetration of the seal is arranged on the wire harness ball seat. One end of the seal cooperates with the passage hole and the end of the seal is a flanging portion. The flanging portion fits with the first step on the wire harness ball seat. A fixing plate for fixing the seal is further arranged on the wire harness ball seat. The fixing plate fits on the first step and the second step and the fixing plate is connected to the wire harness ball seat through a connecting member.

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