Double-end spline self-centering torsion bar for automobile steering system

Abstract

The invention relates to the related technical field of automobile parts, and discloses a double-end spline self-centering torsion bar for an automobile steering system, which comprises a bar body, spline parts arranged at two ends of the bar body, variable-diameter spline parts arranged at the outer ends of the spline parts, and guide cylinders arranged at the outer ends of the variable-diameter spline parts, the diameter of the guide cylinder is smaller than that of the spline part. The variable-diameter spline part is connected with the spline part and the guide cylinder. The guide cylinders are additionally arranged in front of the splines at the two ends of the double-end spline torsion bar, when an input shaft or an output shaft and a gear are pressed, automatic centering can be achieved through the guide cylinders, the problem that in the prior art, centering is difficult is solved, the variable-diameter spline part is arranged, the double-end spline self-centering torsion bar can be more smoothly inserted, and the service life of the double-end spline self-centering torsion bar is prolonged. Friction and collision in the inserting process are reduced, press-in force is more stable, the situation that the torsion bar is bent or broken to be scrapped is effectively avoided, the rejection rate is reduced, and production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field related to automobile parts, in particular to a double-headed spline self-centering torsion bar used in an automobile steering system. Background Art

[0002] Torsion bars are commonly used in automotive steering systems to transfer steering wheel torque to the steering gear. A common torsion bar connection method is a double-ended spline structure, where both ends of the torsion bar are splined to form an interference fit with the input and output shafts. This double-ended splined torsion bar presents problems with centering difficulties and unstable press-fitting force during press-fitting. Because the force-bearing position of the torsion bar is far from the spline press-fitting position, the torsion bar is more likely to bend or break during press-fitting, resulting in a high scrap rate and increased production costs. This application addresses the above-mentioned issues. Summary of the Invention

[0003] The purpose of the present invention is to provide a double-ended spline self-centering torsion bar for automobile steering systems, which solves the problem of centering difficulty during press-fitting of existing double-ended spline torsion bars and the resulting unstable pressing force, reduces the scrap rate and improves production efficiency.

[0004] The present invention is achieved through the following technical solutions.

[0005] The present invention provides a double-ended spline self-centering torsion bar for an automobile steering system, comprising a rod body, a spline portion arranged at both ends of the rod body, a reducing spline portion arranged at the outer end of the spline portion, and a guide cylinder arranged at the outer end of the reducing spline portion, wherein the diameter of the guide cylinder is smaller than the diameter of the spline portion, the reducing spline portion connects the spline portion and the guide cylinder, the diameter of the end of the reducing spline portion connected to the spline portion is the same as the diameter of the spline portion, the diameter of the end of the reducing spline portion connected to the guide cylinder is the same as the diameter of the guide cylinder, and the diameter of the reducing spline portion changes uniformly.

[0006] The arrangement of the guide cylinder and the reducing spline portion can make the double-ended spline self-centering torsion bar smoother during insertion and reduce friction and collision during the insertion process.

[0007] Furthermore, the reducing spline portion and the guide cylinder are integrally arranged to form a guide assembly, and the guide assembly and the spline portion are detachably connected.

[0008] Since the setting of the reducing spline part and the guide cylinder will increase the length of the torsion bar, if the spline matching position of the gear or input / output shaft is short after installation, the guide cylinder will protrude, which may easily interfere with other components, increase the amount of torsion bar material, and increase the cost. Therefore, a detachable guide assembly is used. After the torsion bar is connected to its transmission part, the guide assembly is disassembled, and the effect of reducing costs and avoiding interference is achieved by reusing the guide assembly.

[0009] Further, a special-shaped jack is provided at the end face of the spline portion, and a plug rod is provided on the guiding assembly. The outer contour of the plug rod is matched with the special-shaped jack, so as to realize the positioning and installation of the guiding assembly.

[0010] Further, the plug rod is a cylinder, a flat portion is provided on the outer contour of the cylinder, and the front end of the cylinder is a wedge-shaped structure. The flat portion plays a positioning role, and the wedge-shaped structure plays an effect of facilitating insertion.

[0011] Further, a magnet structure is provided on the guiding assembly, and the connection between the guiding assembly and the torsion bar is realized through magnetic attraction.

[0012] Further, due to the cooperation of the plug rod and the special-shaped jack in a plugging manner, there will be a certain gap at the plugging portion, and during long-term use, the gap will also be caused due to the wear of the plug rod, resulting in possible relative shaking between the guiding assembly and the spline portion during the pressing process, which is not conducive to the stability of centering and guiding. And even if there is no shaking, the guiding assembly and the spline portion may be separated during the pressing process or the transfer process. Therefore, the guiding assembly further includes a fastening assembly. The fastening assembly includes a transmission assembly and a fastening body. The transmission assembly is connected to the fastening body. The fastening body is arranged on the plug rod. The transmission assembly drives the fastening body to extend radially and abuts against the inner wall of the special-shaped jack to achieve the fastening effect.

[0013] The transmission assembly can optionally adopt any telescopic module, such as an electric cylinder, a motor and a crank structure, a cam structure, etc., for driving the fastening body.

[0014] According to an embodiment of the invention, the fastening assembly further includes a pressing slider. The pressing slider is installed on the guiding cylinder. The height of the pressing slider plus the diameter of the guiding cylinder ≤ the diameter of the spline portion. When the guiding cylinder is pressed, after the pressing slider is extruded, the transmission assembly drives the fastening body to extend radially, so as to realize automatic fastening during the pressing process, and the fastening effect is automatically released after the pressing is completed, improving the production efficiency. And after the pressing is completed, if the pressing is not in place, the pressing slider is still extruded, and it is difficult to disassemble the guiding assembly, and the operator can easily judge that the torsion bar is not pressed in place.

[0015] Further, a groove body is provided in the special-shaped jack. The fastening body can be inserted into the groove body. The end portion of the fastening body is a conical structure. Through the force between the conical structure and the inner wall of the groove body, the fastening and positioning of the guiding assembly are realized, and the accuracy of the relative position between the variable-diameter spline portion and the spline portion is ensured.

[0016] Optionally, the transmission assembly includes a first hydraulic rod and a second hydraulic rod. The first hydraulic rod and the second hydraulic rod are connected through an oil pipe. The first hydraulic rod is connected to the pressing slider. The second hydraulic rod is connected to the fastening body.

[0017] Furthermore, the outer end face of the pressing slider is an inclined plane.

[0018] Furthermore, a plurality of groups of fastening components are provided.

[0019] Advantages of the present invention: By adding guiding cylinders in front of the splines at both ends of the double-headed spline torsion bar, when press-fitting the input shaft, output shaft or gear, the guiding cylinders can be used for automatic centering, avoiding the centering difficulty problem existing in the prior art. And a stepped spline portion is provided, which can make the double-headed spline self-centering torsion bar smoother during insertion, reduce frictional collisions during the insertion process, make the press-in force more stable, effectively avoid the situation of the torsion bar being bent or broken and scrapped, reduce the scrap rate, and improve the production efficiency. Also, by setting the stepped spline portion and the guiding cylinder in a detachable manner, different production requirements can be met. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] The present invention will be further described below with reference to the drawings and embodiments.

[0022] Figure 1 is a schematic diagram of the overall structure of a double-headed spline self-centering torsion bar for an automotive steering system;

[0023] Figure 2 is a schematic diagram of the structure when the guiding component is separated from the spline in Embodiment 2;

[0024] Figure 3 is a schematic diagram of the guiding component in Embodiment 4;

[0025] Figure 4 is a sectional schematic diagram of the guiding component in Embodiment 4;

[0026] Figure 5 is Figure 4 an enlarged schematic diagram of the structure at A in

[0027] Figure 6 is a schematic diagram of the guiding component and the torsion bar after being fixedly installed in Embodiment 4;

[0028] Figure 7 is a schematic diagram of the cooperation between the torsion bar and the input shaft. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be described in detail below with reference to the accompanying drawings of the specification.

[0030] Example 1:

[0031] A double - headed spline self - centering torsion bar for an automotive steering system according to the present invention, as shown in Figure 1 , includes a rod body 1, spline portions 2 provided at both ends of the rod body 1, a stepped - diameter spline portion 3 provided at the outer ends of the spline portions 2, and a guide cylinder 4 provided at the outer ends of the stepped - diameter spline portion 3. The rod body 1, the spline portions 2, the stepped - diameter spline portion 3, and the guide cylinder 4 are coaxially arranged.

[0032] The diameter of the guide cylinder 4 is smaller than that of the spline portion 2. The stepped - diameter spline portion 3 connects the spline portion 2 and the guide cylinder 4. The diameter of the end of the stepped - diameter spline portion 3 connected to the spline portion 2 is the same as that of the spline portion 2, and the diameter of the end of the stepped - diameter spline portion 3 connected to the guide cylinder 4 is the same as that of the guide cylinder 4. The diameter of the stepped - diameter spline portion 3 changes uniformly.

[0033] By adding a guide cylinder before the splines at both ends of the double - headed spline torsion bar, when press - fitting the input shaft 7 or the output shaft and the gear, the guide cylinder 4 can be used for automatic centering, avoiding the centering difficulty problem existing in the prior art. And with the stepped - diameter spline portion 3 provided, the double - headed spline self - centering torsion bar can be inserted more smoothly, reducing the frictional collision during the insertion process, making the press - in force more stable, effectively avoiding the situation of the torsion bar being bent or broken and scrapped, reducing the scrap rate, and improving the production efficiency.

[0034] As shown in Figure 7 , after the torsion bar is installed, the spline portion 2 and the spline of the output shaft or the gear are generally in interference fit.

[0035] In this embodiment, the stepped - diameter spline portion 3 and the guide cylinder 4 are integrally formed on the torsion bar. The setting of the guide cylinder enhances the strength and stiffness of the torsion bar, enabling it to cope with larger torques and assembly forces, and meeting the requirements of the automotive steering system for the performance of the torsion bar.

[0036] Example 2:

[0037] Based on Example 1, in this embodiment, as shown in Figure 2 , the stepped - diameter spline portion 3 and the guide cylinder 4 are integrally arranged to form a guide assembly, and the guide assembly is detachably connected to the spline portion 2.

[0038] Since the setting of the stepped - diameter spline portion 3 and the guide cylinder 4 will increase the length of the torsion bar, when the spline mating position of components such as gears or the input / output shaft 7 is short after installation, the guide cylinder 4 will protrude, as shown in Figure 7 , which is likely to cause interference to other components and increase the material consumption of the torsion bar, raising the cost. Therefore, a detachable guide assembly is adopted. After the torsion bar is connected to its transmission parts, the guide assembly is disassembled, achieving the effects of cost reduction and interference avoidance through the reuse of the guide assembly.

[0039] An irregular socket 21 is provided at the end face of the spline portion 2, and a plug rod 5 is provided on the guiding assembly. The outer contour of the plug rod 5 is matched with the irregular socket 21, so as to realize the positioning and installation of the guiding assembly.

[0040] The irregular socket 21 can adopt a triangular or square hole. In this embodiment, the plug rod 5 is a cylinder, and a flat portion 51 is provided on the outer contour of the cylinder. The front end of the cylinder is a wedge-shaped structure. The flat portion 51 plays a positioning role, and the wedge-shaped structure plays an effect of facilitating insertion.

[0041] Optionally, a magnet structure is provided on the guiding assembly, and the connection between the guiding assembly and the torsion rod is realized by magnetic attraction. The magnet structure can be provided at the contact position between the guiding assembly and the end face of the spline portion 2.

[0042] Embodiment 3:

[0043] On the basis of Embodiment 2, as Figure 5 , since the plug rod 5 and the irregular socket 21 are inserted and matched, there will be a certain gap at the insertion part, and during long-term use, the gap will also be caused due to the wear of the plug rod 5, resulting in possible relative shaking between the guiding assembly and the spline portion 2 during the press-fitting process, which is not conducive to the stability of centering and guiding. And even if there is no shaking, the guiding assembly and the spline portion 2 may be separated during the press-fitting process or the transfer process. Therefore, the guiding assembly further includes a fastening assembly. The fastening assembly includes a transmission assembly and a fastener 52. The transmission assembly is connected to the fastener 52. The fastener 52 is arranged on the plug rod 5. The transmission assembly drives the fastener 52 to extend radially outwards and abuts against the inner wall of the irregular socket 21 to achieve the fastening effect.

[0044] The transmission assembly can optionally adopt any telescopic module, such as an electric cylinder, a motor and a crank structure, a cam structure, etc., for driving the fastener 52.

[0045] Embodiment 4:

[0046] On the basis of Embodiment 3, in this embodiment, as Figure 3 , Figure 4 , Figure 5 , the fastening assembly further includes a pressing slider 41. The outer end face of the pressing slider 41 is an inclined plane. The pressing slider 41 is installed on the guiding cylinder 4. An installation hole for the pressing slider 41 to slide is provided in the guiding cylinder 4. A spring 61 connected to the pressing slider 41 is provided in the installation hole, which is used to play a role in resetting the pressing slider 41.

[0047] The height of the pressing slider 41 plus the diameter of the guiding cylinder 4 ≤ the diameter of the spline portion 2. When the guiding cylinder 4 is press-fitted, after the pressing slider 41 is extruded by the inner wall of the gear or the input shaft, the transmission assembly drives the fastening member 52 to extend radially, so as to achieve automatic fastening during the press-fitting process, and the fastening effect is automatically released after the press-fitting is completed, improving production efficiency; and after the press-fitting is completed, if the press-fitting is not in place, the pressing slider 41 is still extruded, and it is difficult to disassemble the guiding assembly, and the operator can easily judge that the torsion bar is not press-fitted in place.

[0048] Preferably, an annular groove 22 is machined in the special-shaped jack 21, and the fastening member 52 can be inserted into the groove 22. The end of the fastening member 52 is a conical structure. Through the force between the conical structure and the inner wall of the groove 22, the fastening and positioning of the guiding assembly are realized, ensuring the accuracy of the relative position between the variable-diameter spline portion 3 and the spline portion 2.

[0049] In this embodiment, the transmission assembly includes a first hydraulic rod 62 and a second hydraulic rod 64. The first hydraulic rod 62 and the second hydraulic rod 64 are connected by an oil pipe 63. The first hydraulic rod 62 is connected to the pressing slider 41, and the second hydraulic rod 64 is connected to the fastening member 52. An installation groove for accommodating the fastening member 52 is provided in the inserting rod 5, and the fastening member 52 can slide in the installation groove. A spring 64 connected to the fastening member 52 is provided in the installation groove to play a role in resetting the fastening member 52. When the pressing slider 41 is pressed, the piston rod of the first hydraulic rod 62 is pressed, so that the oil fluid on the lower side of the piston valve enters the second hydraulic rod 64 through the oil pipe 63, and the piston rod of the second hydraulic rod 64 drives the fastening member 52 to extend. When the pressing slider 41 is no longer pressed, it is reset under the action of the spring.

[0050] Such as Figure 4 , the guiding cylinder 4 and the inserting rod 5 can be integrally designed and are assembled by two left and right half structures and fixed by screws. The oil circuit and the hydraulic cylinder therein can be machined by grooving in the structure, and the two half-assembled structures are convenient for the installation of the piston, the pressing slider 41 and the fastening member 52. The variable-diameter spline portion 3 is connected to the integral structure by welding or screws.

[0051] In other embodiments, the transmission assembly can also adopt a connecting rod structure to realize the transmission of force, or can also adopt a distance or pressure sensor to detect the position of the pressing slider 41. When the pressing slider 41 is pressed to a set position, the sensor sends an instruction to the motor, and the fastening member 52 is driven to extend through a linear driving structure such as a cam and a crank.

[0052] Optionally, 1 to 3 groups of fastening assemblies are provided.

[0053] The above embodiments are only used to illustrate the technical concept and features of the present invention. The purpose is to enable those skilled in the art to understand the content of the present invention and implement it, and it cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A double-headed spline self-centering torsion bar for an automotive steering system, characterized in that: It includes a rod body (1), spline parts (2) arranged at both ends of the rod body (1), a stepped spline part (3) arranged at the outer end of the spline part (2), and a guiding cylinder (4) arranged at the outer end of the stepped spline part (3). The diameter of the guiding cylinder (4) is smaller than that of the spline part (2). The stepped spline part (3) connects the spline part (2) and the guiding cylinder (4). The diameter of the end of the stepped spline part (3) connected to the spline part (2) is the same as that of the spline part (2), and the diameter of the end of the stepped spline part (3) connected to the guiding cylinder (4) is the same as that of the guiding cylinder (4). The diameter of the stepped spline part (3) changes uniformly.

2. The double-headed spline self-centering torsion bar for an automotive steering system according to claim 1, wherein: The stepped spline part (3) and the guiding cylinder (4) are integrally arranged to form a guiding assembly, and the guiding assembly is detachably connected to the spline part (2).

3. The double-headed spline self-centering torsion bar for an automotive steering system according to claim 2, characterized in that: A special-shaped jack (21) is arranged at the end face of the spline part (2), and a plug rod (5) is arranged on the guiding assembly. The outer contour of the plug rod (5) is matched with the special-shaped jack (21).

4. The double-headed spline self-centering torsion bar for an automotive steering system according to claim 3, characterized in that: The plug rod (5) is a cylinder, and a flat part (51) is arranged on the outer contour of the cylinder. The front end of the cylinder is a wedge-shaped structure.

5. The double-headed spline self-centering torsion bar for an automotive steering system according to any one of claims 2-4, characterized in that: A magnet structure is arranged on the guiding assembly.

6. The double-headed spline self-centering torsion bar for an automotive steering system according to any one of claims 2-4, characterized in that: The guiding assembly further includes a fastening assembly. The fastening assembly includes a transmission assembly and a fastener (52). The transmission assembly is connected to the fastener (52). The fastener (52) is arranged on the plug rod (5). The transmission assembly drives the fastener (52) to extend radially and abuts against the inner wall of the special-shaped jack (21) to achieve a fastening effect.

7. The double-headed spline self-centering torsion bar for an automotive steering system according to claim 6, characterized in that: The fastening assembly further includes a pressing slider (41). The pressing slider (41) is installed on the guiding cylinder (4). The height of the pressing slider (41) plus the diameter of the guiding cylinder (4) ≤ the diameter of the spline part (2). When the guiding cylinder (4) is press-fitted, after the pressing slider (41) is squeezed, the transmission assembly drives the fastener (52) to extend radially.

8. The double-headed spline self-centering torsion bar for an automotive steering system according to claim 7, characterized in that: A groove body (22) is arranged in the special-shaped jack (21). The fastener (52) can be inserted into the groove body (22), and the end of the fastener (52) is a conical structure.

9. The double-headed spline self-centering torsion bar for an automotive steering system according to claim 7 or 8, characterized in that: The transmission assembly includes a first hydraulic rod (62) and a second hydraulic rod (64). The first hydraulic rod (62) is connected to the second hydraulic rod (64) through an oil pipe (63). The first hydraulic rod (62) is connected to the pressing slider (41), and the second hydraulic rod (64) is connected to the fastener (52).

10. The double-headed spline self-centering torsion bar for an automotive steering system according to claim 7 or 8, characterized in that: Several groups of the fastening assemblies are arranged.

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