Rigidity-variable steering rod structure of steering gear

Abstract

The invention relates to the field of automobile steering rods, in particular to a variable-rigidity steering rod structure of a steering gear, which comprises a hollow outer shaft rod, an inner shaft rod and a moving device, a plurality of strip-shaped through holes are formed in the side wall of the upper half part of the hollow outer shaft rod, and a plurality of strip-shaped caulking grooves are formed in the inner wall of the hollow outer shaft rod; a plurality of filling strips in one-to-one correspondence with the strip-shaped caulking grooves are formed on the outer wall of the inner shaft rod, the filling strips are arranged in the corresponding strip-shaped caulking grooves in a sliding mode respectively, the upper end of the hollow outer shaft rod is connected with a steering wheel, and the lower end of the hollow outer shaft rod is connected with an input shaft of a steering gear box. The through hole is formed in a traditional integrated steering rod to reduce the torsional rigidity of the steering shaft, so that the softer steering hand feeling is achieved, a structure capable of adjusting the effective stroke of the through hole is additionally arranged on the basis of hole opening to achieve soft and hard flexible adjustment of the steering hand feeling, internal installation and external installation are provided for different vehicle types, and the steering effect is improved. Therefore, refitting requirements of more vehicle types can be met, and the adaptability is wide.

Description

Technical Field

[0001] The invention relates to the field of automobile steering rods, in particular to a variable stiffness steering rod structure of a steering gear. Background Art

[0002] The steering wheel and the steering rod are mechanically connected. The central axis of the steering wheel is usually fixed to the upper end of the steering rod through a spline or other reliable connection method. When the driver turns the steering wheel, the rotation of the steering wheel is directly transmitted to the steering rod, and the steering rod then transmits the rotation to the steering gear located on the front axle of the chassis. The steering gear (steering gear) is a key component of the steering system. When the steering rod transmits the torque to the steering gear, the steering gear amplifies the torque and changes the direction of movement through the internal gear mechanism or screw-nut mechanism, etc., and the steering process of the car is complete.

[0003] At present, the change in steering feel of a vehicle when driving at low and high speeds is mainly achieved by changing the size of the electronic steering assist through the on-board computer. That is, the steering feel of most vehicles only has two conditions: heavy at high speed and light at low speed. For users who want diversified steering feel, the experience is poor. Summary of the invention

[0004] Based on this, it is necessary to provide a variable stiffness steering rod structure of a steering gear in view of the existing technical problems.

[0005] In order to solve the problems of the prior art, the technical solution adopted by the present invention is:

[0006] A variable stiffness steering rod structure of a steering gear comprises a hollow outer shaft, an inner shaft movably arranged on the inner side of the hollow outer shaft, and a moving device for controlling the axial movement of the inner shaft in the hollow outer shaft, a plurality of strip-shaped through holes evenly distributed along the circumferential direction for reducing the stiffness of the hollow outer shaft are opened on the side wall of the upper half of the hollow outer shaft, a plurality of strip-shaped embedded grooves evenly distributed along the circumferential direction are formed on the inner wall of the hollow outer shaft, a plurality of filling strips corresponding to the strip-shaped embedded grooves are formed on the outer wall of the inner shaft, and the filling strips are respectively slidably arranged in the corresponding strip-shaped embedded grooves, the upper end of the hollow outer shaft is connected to the steering wheel, and the lower end is connected to the input shaft of the steering gear.

[0007] Furthermore, the length of the inner shaft is not less than the length of the strip-shaped through hole, the number of the strip-shaped embedding grooves is the same as the number of the strip-shaped through holes, and each of the strip-shaped embedding grooves is located between two adjacent strip-shaped through holes.

[0008] Furthermore, the moving device includes a driving motor, a screw rod and an inner shaft lifting mechanism cooperating with the screw rod, the screw rod is threadedly connected to the inner shaft lifting mechanism, the driving motor is fixedly arranged and its output shaft is fixedly connected to one end of the screw rod, and the inner shaft lifting mechanism is connected to the inner shaft rod to drive it to move synchronously.

[0009] Furthermore, the drive motor and the screw rod are both located on the outside of the hollow outer shaft rod, the drive motor is fixedly arranged on the outer wall of the hollow outer shaft rod by a bracket, the output shaft of the drive motor is arranged upward and connected to the lower end of the screw rod, the upper and lower ends of the screw rod are connected to the outer wall of the hollow outer shaft rod by a bearing seat, the inner shaft lifting mechanism includes an outer ring, an inner ring and a magnetic synchronization mechanism, the outer ring is movably sleeved on the outside of the hollow outer shaft rod, the inner ring is fixedly sleeved on the lower end of the inner shaft rod, the magnetic synchronization mechanism is arranged between the outer ring and the inner ring, and the screw rod is threadedly connected to the outer ring.

[0010] Furthermore, the magnetic attraction synchronization mechanism includes several groups of pole pieces, each group of pole pieces is composed of a first permanent magnet piece and a second permanent magnet piece, all the first permanent magnet pieces are evenly distributed along the circumferential direction and embedded on the inner wall of the outer ring, all the second permanent magnet pieces are evenly distributed along the circumferential direction and embedded on the outer wall of the inner ring, all the first permanent magnet pieces and all the second permanent magnet pieces are arranged in a one-to-one correspondence, and each of the first permanent magnet pieces and the corresponding second permanent magnet piece have opposite magnetic properties on the opposite side, and the outer wall of the hollow outer shaft rod is formed with several first limit strips evenly distributed along the circumferential direction, and the first limit strips are slidably engaged with the inner wall of the outer ring, and the lower end of the inner shaft rod is formed with a step groove for fixing and clamping the inner ring, and the groove wall of the step groove is formed with several second limit strips evenly distributed along the circumferential direction, and the second limit strips are slidably engaged with the inner wall of the inner ring.

[0011] Furthermore, the number of the screw rods is three, and the three screw rods are evenly distributed in the circumferential direction on the outside of the hollow outer shaft rod. The upper and lower ends of the outer sleeve are formed with annular plate support parts extending outward, and the annular plate support part is provided with three threaded sleeves evenly distributed along its circumference, and both ends of each threaded sleeve are respectively rotatably connected to the upper and lower annular plate support parts, and a synchronous wheel is fixedly sleeved on the outside of each threaded sleeve, and the synchronous wheel is located between the two annular plate support parts, and each threaded sleeve is threadedly connected to the corresponding screw rod, one of the synchronous wheels is a double-groove pulley, and two synchronous belts are sleeved on the double-groove pulley, and the other ends of the two synchronous belts are respectively connected to the other two synchronous wheels, and the driving shaft of the driving motor is connected to the screw rod passing through the double-groove pulley through a coupling, and a group of rollers for preventing the synchronous belt from contacting the outer sleeve are provided between every two adjacent synchronous wheels.

[0012] Furthermore, the wire braces are composed of a braces body and a retaining ring, the lower edge of the braces body is formed with an annular limit plate extending outward, the outer wall of the braces body is formed with a rib key strip for interference connection with the inner wall of the synchronous wheel, the retaining ring is interference-fitted on the upper end of the braces body, and the two annular plate support parts are located between the retaining ring and the annular limit plate.

[0013] Furthermore, the drive motor is coaxially fixed on the inner side of the hollow outer shaft through a star-shaped bracket, the outer side of the star-shaped bracket is fixedly connected to the inner wall of the hollow outer shaft, the drive motor is vertically fixed at the center of the star-shaped bracket, the screw rod is located above the drive motor, the lower end of the screw rod is connected to the output shaft of the drive motor, the inner shaft is located above the star-shaped bracket, and a herringbone bearing frame for connecting the upper end of the screw rod is fixedly provided on the inner side of the upper end of the hollow outer shaft, and the herringbone bearing frame is higher than the upper end of the strip-shaped through hole.

[0014] Furthermore, the inner shaft lifting mechanism is a herringbone bracket, which is coaxially fixed at the center of the lower end of the inner shaft rod, and a threaded hole cooperating with the screw rod is provided at the center of the herringbone bracket.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Firstly, the present invention reduces the torsional rigidity of the steering shaft by opening a through hole in the traditional integrated steering rod, thereby achieving a softer steering feel;

[0017] Secondly, the present invention adds a structure with adjustable effective stroke of the through hole on the basis of the opening to realize flexible adjustment of the softness and hardness of the steering feel;

[0018] Thirdly, the present invention provides two modes of interior and exterior installation for different vehicle models to match the modification requirements of more vehicle models and has wide adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the positional relationship and connection between the steering rod structure and the steering system of the present invention;

[0020] Figure 2 is a schematic diagram of the three-dimensional structure of the steering rod structure of the first embodiment of the present invention;

[0021] Figure 3 is a front view of the first embodiment of the present invention;

[0022] Figure 4 yes Figure 3 Schematic diagram of plane section along line AA;

[0023] Figure 5Schematic diagram of the magnetic attraction cooperation principle between the inner sleeve ring and the outer sleeve ring in the first embodiment of the present invention;

[0024] Figure 6 is a three-dimensional cross-sectional view of the first embodiment of the present invention;

[0025] Figure 7 yes Figure 6 A schematic diagram of the structure at B in FIG.

[0026] Figure 8 yes Figure 6 Schematic diagram of the local structure at the C viewing angle along the middle edge;

[0027] Fig. 9 is a schematic plan cross-sectional view of a second embodiment of the present invention;

[0028] The numbers in the figure are: 1-steering wheel; 2-universal joint; 3-steering machine; 4-hollow outer shaft; 5-inner shaft; 6-strip through hole; 7-strip embedded groove; 8-filling strip; 9-driving motor; 10-screw; 11-bearing seat; 12-outer ring; 13-inner ring; 14-first permanent magnet; 15-second permanent magnet; 16-first limit strip; 17-second limit strip; 18-annular plate support; 19-thread sleeve; 20-synchronous wheel; 21-double-groove pulley; 22-synchronous belt; 23-coupling; 24-roller; 25-sleeve body; 26-circlip; 27-rib key strip; 28-star bracket; 29-herringbone bearing frame; 30-herringbone bracket. DETAILED DESCRIPTION

[0029] In order to further understand the features, technical means, specific objectives and functions of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0030] Reference Figure 1 As shown, the variable stiffness steering rod structure of the present invention is located in the steering gear 3 assembly, specifically located below the steering wheel 1 and above the steering gear 3. The variable stiffness steering rod of the present invention is used to connect the steering wheel 1 and the input shaft of the steering gear 3, and is used to transmit the rotation amount of the steering wheel 1 to the steering gear 3 to drive the front wheel steering. Compared with the traditional steering rod structure, the traditional steering rod is a whole solid shaft or a hollow shaft, and its torsional stiffness cannot be changed and adjusted. The present invention redesigns the middle position of the traditional steering rod (the upper end of the steering rod is connected to the steering wheel 1, and the lower end is connected to the steering gear 3 through the universal joint 2) to make it have the characteristic of adjustable torsional stiffness. The specific implementation method is as follows: Specific embodiment one:

[0032] Reference Figures 2 to 8A variable stiffness steering rod structure of a steering gear is shown, comprising a hollow outer shaft rod 4, an inner shaft rod 5 movably arranged on the inner side of the hollow outer shaft rod 4, and a moving device for controlling the axial movement of the inner shaft rod 5 in the hollow outer shaft rod 4. A plurality of strip-shaped through holes 6 uniformly distributed along the circumferential direction for reducing the stiffness of the hollow outer shaft are opened on the side wall of the upper half of the hollow outer shaft rod 4. A plurality of strip-shaped embedded grooves 7 uniformly distributed along the circumferential direction are formed on the inner wall of the hollow outer shaft rod 4. A plurality of filling strips 8 corresponding to the strip-shaped embedded grooves 7 are formed on the outer wall of the inner shaft rod 5. The filling strips 8 are respectively slidably arranged in the corresponding strip-shaped embedded grooves 7. The upper end of the hollow outer shaft rod 4 is connected to the steering wheel 1, and the lower end is connected to the input shaft of the steering gear 3.

[0033] The rotation torque of the steering wheel 1 is transmitted to the input shaft of the steering gear 3 below through the hollow outer shaft 4. Due to the presence of several strip-shaped through holes 6 on the hollow outer shaft 4, these strip-shaped through holes 6 reduce the amount of material of the shaft wall, so that the hollow outer shaft 4 can produce more parts that can be deformed when subjected to external forces. For example, under the action of torsional force, the hollow outer shaft 4 without the strip-shaped through holes 6 mainly resists the torque through the shear deformation of the shaft wall material, while with the strip-shaped through holes 6, the material around the strip-shaped through holes 6 is more likely to produce local deformation under the action of torque. For the hollow outer shaft 4, when there are strip-shaped through holes 6, the cross-sectional inertia moment of the shaft is reduced, thereby making the steering feel softer and more comfortable than the traditional steering rod. The hollow outer shaft 4 of the present invention is made of a material with a certain toughness. If cost is not considered, it is best to use memory metal.

[0034] When the steering feel needs to be changed, the moving device is used to drive the inner shaft rod 5 to move axially in the hollow outer shaft rod 4, and the strip 8-shaped through hole 6 is filled from the inside through the movement of the inner shaft rod 5, thereby reducing the effective length of the strip through hole 6, and the filling strip 8 on the outer wall of the inner shaft rod 5 is embedded in the strip groove 7 on the inner wall of the hollow outer shaft rod 4 to slide. When the filling strip 8 enters the strip groove 7 within the length range of the strip through hole 6, due to the extremely large rigidity of the inner shaft rod 5, under the circumferential limiting action of the filling strip 8, the hollow outer shaft rod 4 within the range of the strip through hole 6 covered by the inner shaft rod 5 is difficult to torsionally deform, thereby increasing the torsional rigidity of the hollow outer shaft rod 4, and then making the steering feel turn to a tough and follow-up style. When the inner shaft rod 5 completely covers and blocks the strip through hole 6, the hollow outer shaft rod 4 will be difficult to torsionally deform. At this time, the rigidity of the hollow outer shaft rod 4 reaches its maximum value, and the steering feel at this time is an extremely sporty driving style.

[0035] The steering rod structure of the present invention drives the inner shaft rod 5 to adjust the effective action length of the strip-shaped through hole 6 through the action of the moving device, thereby achieving the purpose of adjusting the steering feel of the steering wheel 1.

[0036] In order to achieve the maximum rigidity of the hollow outer shaft rod 4 which is completely non-twistable, the following features are specifically provided:

[0037] The length of the inner shaft 5 is not less than the length of the strip-shaped through hole 6 , the number of the strip-shaped embedding grooves 7 is the same as the number of the strip-shaped through holes 6 , and each of the strip-shaped embedding grooves 7 is located between two adjacent strip-shaped through holes 6 .

[0038] By setting the length of the inner shaft rod 5 to be greater than the length of the strip through hole 6, it is ensured that the inner shaft rod 5 can completely cover the effective range of the strip through hole 6. When the inner shaft rod 5 completely covers the strip through hole 6, when all filling strips 8 perform circumferential anti-twist on the strip embedded groove 7, it can effectively prevent the hollow outer shaft rod 4 from twisting, thereby ensuring the tough effect of the transformation feel at this time.

[0039] When there is no intersection between the inner shaft rod 5 and the strip-shaped through hole 6, the hollow outer shaft rod 4 has the minimum torsional rigidity, and the steering feel achieves the best soft and comfortable effect.

[0040] In order to achieve the purpose of flexible and rapid adjustment of the displacement of the inner shaft rod 5, the following features are specifically set:

[0041] The moving device includes a driving motor 9, a screw rod 10 and an inner shaft lifting mechanism matched with the screw rod 10, the screw rod 10 is threadedly connected to the inner shaft lifting mechanism, the driving motor 9 is fixedly arranged and its output shaft is fixedly connected to one end of the screw rod 10, and the inner shaft lifting mechanism is connected to the inner shaft rod 5 to drive it to move synchronously.

[0042] The screw rod 10 is rotated by the driving motor 9, and the screw rod 10 cooperates with the inner shaft lifting mechanism. The rotation of the screw rod 10 drives the inner shaft lifting mechanism to perform axial displacement, thereby driving the inner shaft rod 5 to be displaced through the inner shaft lifting mechanism. When adjusting, it is only necessary to control the operation of the driving motor 9 through the operating buttons in the cab, so as to realize the flexible adjustment of the steering rod stiffness. At the same time, the driving computer can also automatically adjust according to the vehicle speed.

[0043] In order to ensure that the effect of the variable stiffness steering rod can be smoothly experienced when the inner diameter of the steering rod of the target vehicle model is small and it is difficult to install the drive motor 9, the following features are specifically set:

[0044] The drive motor 9 and the screw rod 10 are both located on the outside of the hollow outer shaft 4. The drive motor 9 is fixedly arranged on the outer wall of the hollow outer shaft 4 through a bracket. The output shaft of the drive motor 9 is arranged upward and connected to the lower end of the screw rod 10. The upper and lower ends of the screw rod 10 are connected to the outer wall of the hollow outer shaft 4 through a bearing seat 11. The inner shaft lifting mechanism includes an outer sleeve 12, an inner sleeve 13 and a magnetic synchronization mechanism. The outer sleeve 12 is movably sleeved on the outside of the hollow outer shaft 4, and the inner sleeve 13 is fixedly sleeved on the lower end of the inner shaft 5. The magnetic synchronization mechanism is arranged between the outer sleeve 12 and the inner sleeve 13, and the screw rod 10 is threadedly connected to the outer sleeve 12.

[0045] The drive motor 9 in this embodiment is external, that is, the drive motor 9 is installed outside the shaft. The drive motor 9 drives the screw 10 to rotate when it works. The rotation of the screw 10 drives the outer ring 12 that is threadedly matched with it to perform axial displacement along the hollow outer shaft 4. During this process, the outer ring 12 drives the inner ring 13 on the inside to displace together with the inner shaft 5 through the magnetic synchronization mechanism, thereby realizing the flexible movement of the inner shaft 5, and then achieving the purpose of adjusting the torsional stiffness of the hollow outer shaft 4. Grease is applied between the outer wall of the inner shaft 5 and the inner wall of the hollow outer shaft 4 to reduce sliding resistance.

[0046] In order to achieve a contactless synchronous displacement effect between the outer ring 12 and the inner ring 13, the following features are specifically set:

[0047] The magnetic attraction synchronization mechanism includes several groups of pole pieces, each group of pole pieces is composed of a first permanent magnet piece 14 and a second permanent magnet piece 15, all first permanent magnet pieces 14 are evenly distributed along the circumferential direction and embedded on the inner wall of the outer ring 12, all second permanent magnet pieces 15 are evenly distributed along the circumferential direction and embedded on the outer wall of the inner ring 13, all first permanent magnet pieces 14 and all second permanent magnet pieces 15 are arranged in a one-to-one correspondence, and each first permanent magnet piece 14 and the corresponding second permanent magnet piece 15 have opposite magnetic properties on the opposite side, and the outer wall of the hollow outer shaft rod 4 is formed with a plurality of first limit strips 16 evenly distributed along the circumferential direction, and the first limit strips 16 are slidably engaged with the inner wall of the outer ring 12, and the lower end of the inner shaft rod 5 is formed with a step groove for fixing and clamping the inner ring 13, and the groove wall of the step groove is formed with a plurality of second limit strips 17 evenly distributed along the circumferential direction, and the second limit strips 17 are slidably engaged with the inner wall of the inner ring 13.

[0048] Reference Figure 5As shown, a plurality of groups of magnetic pole pieces are arranged between the outer ring 12 and the inner ring 13. Each group of magnetic pole pieces ensures the synchronous movement of the outer ring 12 and the inner ring 13 by the cooperation of the first permanent magnet piece 14 and the second permanent magnet piece 15 which are attracted by each other magnetically. During this process, the inner ring 13 will not rotate under the effect of the second limit bar 17, and the outer ring 12 will not rotate under the effect of the first limit bar 16. In this way, it is ensured that each pair of the first permanent magnet piece 14 and the second permanent magnet piece 15 is always in a one-to-one corresponding state, and the magnetic attraction cooperation between the outer ring 12 and the inner ring 13 is stable and reliable.

[0049] In order to ensure uniform force during the axial movement of the outer ring 12, the following features are specifically set:

[0050] The number of the screw rods 10 is three, and the three screw rods 10 are evenly distributed along the circumferential direction and arranged on the outside of the hollow outer shaft rod 4. The upper and lower ends of the outer sleeve 12 are formed with an annular plate support portion 18 extending outward, and the annular plate support portion 18 is provided with three threaded sleeves 19 evenly distributed along its circumference. Both ends of each threaded sleeve 19 are rotatably connected to the upper and lower annular plate support portions 18, respectively. A synchronous wheel 20 is fixedly sleeved on the outside of each threaded sleeve 19, and the synchronous wheel 20 is located between the two Between the annular plate support parts 18, each threaded sleeve 19 is threadedly connected to the corresponding screw rod 10, one of the synchronous wheels 20 is a double-groove pulley 21, and two synchronous belts 22 are sleeved on the double-groove pulley 21. The other ends of the two synchronous belts 22 are respectively connected to the other two synchronous wheels 20, and the driving shaft of the drive motor 9 is connected to the screw rod 10 passing through the double-groove pulley 21 through a coupling 23. A group of rollers 24 are arranged between every two adjacent synchronous wheels 20 to prevent the synchronous belt 22 from contacting the outer ring 12.

[0051] By increasing the number of lead screws to three and evenly distributing them on the outer ring 12, the three lead screws 10 rotate simultaneously to achieve three-point synchronous propulsion of the outer ring 12 in the circumferential direction, thereby ensuring that the outer ring 12 will not get stuck with the outer wall of the hollow outer shaft 4 due to uneven force during movement.

[0052] More specifically, the driving motor 9 drives the double-groove pulley 21 connected thereto to rotate, and the double-groove pulley 21 in turn drives the two synchronous wheels 20 connected thereto to rotate, and in the transmission connection mode again, the double-groove pulley 21 has the same rotation direction as the two synchronous wheels 20, so that the three screw rods 10 are driven to rotate synchronously through the three synchronous wheels 20 with the same rotation direction, and then the outer ring 12 is synchronously driven to perform axial displacement along the hollow outer shaft rod 4 through the three threaded sleeves 19 respectively matched with the corresponding screw rods 10.

[0053] In order to facilitate the assembly between the thread sleeve 19, the outer sleeve 12 and the synchronous wheel 20, the following features are specifically set:

[0054] The wire braces 19 is composed of a braces body 25 and a retaining ring 26. The lower edge of the braces body 25 is formed with an annular limit plate extending outward, and the outer wall of the braces body 25 is formed with a rib key strip 27 for interference connection with the inner wall of the synchronous wheel 20. The retaining ring 26 is interference-fitted on the upper end of the braces body 25, and the two annular plate support parts 18 are both located between the retaining ring 26 and the annular limit plate.

[0055] When installing the synchronous wheel 20 and the synchronous belt 22, firstly, the three synchronous wheels 20 and the two synchronous belts 22 are socketed with each other, and then the whole is placed between the two annular plate support parts 18, and then the brace body 25 is installed one by one. In this process, the rib key strip 27 on the outer wall of the brace body 25 is interference fit into the inner hole of the synchronous wheel 20 by crimping. At this time, a section of the brace body 25 extends upward from the annular plate support part 18, and finally, the retaining ring 26 is crimped one by one to the protruding section of the brace body 25 to complete the installation, and finally, the rollers 24 are inserted one by one to limit the synchronous belt 22. Specific embodiment 2:

[0057] When the space inside the steering rod shaft of the target vehicle model is sufficient to accommodate the drive motor 9, the built-in installation method can be adopted, and the following features are specifically set:

[0058] Reference Fig. 9 As shown, the drive motor 9 is coaxially fixed on the inner side of the hollow outer shaft 4 through a star-shaped bracket 28, the outer side of the star-shaped bracket 28 is fixedly connected to the inner wall of the hollow outer shaft 4, the drive motor 9 is vertically fixed at the center of the star-shaped bracket 28, the screw rod 10 is located above the drive motor 9, the lower end of the screw rod 10 is connected to the output shaft of the drive motor 9, the inner shaft 5 is located above the star-shaped bracket 28, and a herringbone bearing frame 29 for connecting the upper end of the screw rod 10 is fixedly provided on the inner side of the upper end of the hollow outer shaft 4, and the herringbone bearing frame 29 is higher than the upper end of the strip through hole 6.

[0059] In this way, the drive motor 9 and the screw rod 10 are both installed inside, and the overall effect is more beautiful and simple. A herringbone bearing frame 29 is added to the upper free end of the screw rod 10 to limit the rotation of the upper end of the screw rod 10, further ensuring the stable rotation of the screw rod 10, preventing the screw rod 10 from shaking during the rapid rotation process, and ensuring the uniformity and consistency of the friction between the outer wall of the inner ring 13 and the inner wall of the hollow outer shaft rod 4. The inner shaft lifting mechanism is a herringbone bracket 30, which is fixedly arranged at the lower end center of the inner shaft rod 5 in a coaxial state, and a threaded hole matching with the screw rod 10 is provided at the center of the herringbone bracket 30. The drive motor 9 drives the screw rod 10 to rotate, and the inner shaft rod 5 is more stably threaded with the screw rod 10 through the herringbone bracket 30 embedded in the inner side of its bottom, which greatly ensures the sensitivity and reliability of the inner shaft rod 5 in responding to the axial position.

[0060] The above embodiments only express one or several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A variable stiffness steering rod structure of a steering gear, characterized in that: The invention comprises a hollow outer shaft (4), an inner shaft (5) movably arranged inside the hollow outer shaft (4), and a moving device for controlling the axial movement of the inner shaft (5) inside the hollow outer shaft (4); a plurality of strip-shaped through holes (6) evenly distributed along the circumferential direction for reducing the rigidity of the hollow outer shaft are opened on the side wall of the upper half of the hollow outer shaft (4); a plurality of strip-shaped embedded grooves (7) evenly distributed along the circumferential direction are formed on the inner wall of the hollow outer shaft (4); a plurality of filling strips (8) corresponding to the strip-shaped embedded grooves (7) are formed on the outer wall of the inner shaft (5); the filling strips (8) are respectively slidably arranged in the corresponding strip-shaped embedded grooves (7); the upper end of the hollow outer shaft (4) is connected to the steering wheel (1), and the lower end is connected to the input shaft of the steering gear (3).

2. The variable stiffness steering rod structure of a steering gear according to claim 1, characterized in that: The length of the inner shaft (5) is not less than the length of the strip-shaped through hole (6), the number of the strip-shaped embedded grooves (7) is the same as the number of the strip-shaped through holes (6), and each of the strip-shaped embedded grooves (7) is located between two adjacent strip-shaped through holes (6).

3. The variable stiffness steering rod structure of a steering gear according to claim 1, characterized in that: The moving device comprises a driving motor (9), a screw rod (10) and an inner shaft lifting mechanism matched with the screw rod (10); the screw rod (10) is threadedly connected to the inner shaft lifting mechanism; the driving motor (9) is fixedly arranged and its output shaft is fixedly connected to one end of the screw rod (10); the inner shaft lifting mechanism is connected to the inner shaft rod (5) to drive the inner shaft rod (5) to move synchronously.

4. The variable stiffness steering rod structure of a steering gear according to claim 3, characterized in that: The drive motor (9) and the screw rod (10) are both located on the outside of the hollow outer shaft (4); the drive motor (9) is fixedly arranged on the outer wall of the hollow outer shaft (4) by a bracket; the output shaft of the drive motor (9) is arranged upward and connected to the lower end of the screw rod (10); the upper and lower ends of the screw rod (10) are connected to the outer wall of the hollow outer shaft (4) by a bearing seat (11); the inner shaft lifting mechanism comprises an outer sleeve (12), an inner sleeve (13) and a magnetic synchronous mechanism; the outer sleeve (12) is movably sleeved on the outside of the hollow outer shaft (4); the inner sleeve (13) is fixedly sleeved on the lower end of the inner shaft (5); the magnetic synchronous mechanism is arranged between the outer sleeve (12) and the inner sleeve (13); the screw rod (10) is threadedly connected to the outer sleeve (12).

5. The variable stiffness steering rod structure of a steering gear according to claim 4, characterized in that: The magnetic attraction synchronization mechanism comprises a plurality of groups of magnetic pole pieces, each group of magnetic pole pieces comprises a first permanent magnet piece (14) and a second permanent magnet piece (15), all the first permanent magnet pieces (14) are evenly distributed along the circumferential direction and embedded on the inner wall of the outer sleeve (12), and all the second permanent magnet pieces (15) are evenly distributed along the circumferential direction and embedded on the outer wall of the inner sleeve (13), all the first permanent magnet pieces (14) and all the second permanent magnet pieces (15) are arranged in a one-to-one correspondence, and each of the first permanent magnet pieces (14) and the corresponding second permanent magnet piece (15) ) have opposite magnetic properties on the opposite side, the outer wall of the hollow outer shaft rod (4) is formed with a plurality of first limit strips (16) evenly distributed along the circumferential direction, the first limit strips (16) are slidably engaged with the inner wall of the outer sleeve ring (12), the lower end of the inner shaft rod (5) is formed with a step groove for fixing and clamping the inner sleeve ring (13), the groove wall of the step groove is formed with a plurality of second limit strips (17) evenly distributed along the circumferential direction, the second limit strips (17) are slidably engaged with the inner wall of the inner sleeve ring (13).

6. The variable stiffness steering rod structure of a steering gear according to claim 4, characterized in that: The number of the screw rods (10) is three, and the three screw rods (10) are evenly distributed along the circumferential direction and arranged on the outer side of the hollow outer shaft (4). The upper and lower ends of the outer sleeve (12) are formed with an annular plate support portion (18) extending outward, and the annular plate support portion (18) is provided with three threaded sleeves (19) evenly distributed along its circumference. The two ends of each threaded sleeve (19) are respectively rotatably connected to the upper and lower annular plate support portions (18), and the outer side of each threaded sleeve (19) is fixedly sleeved with a synchronous wheel (20), and the synchronous wheel (20) is located between the two annular plate support portions. The invention relates to a method for manufacturing a synchronous wheel (20) comprising: a first synchronous wheel (20) and a second synchronous wheel (21). The first synchronous wheel (20) is a synchronous wheel (21) having two synchronous belts (22) mounted thereon. The second synchronous belts (22) are connected to the second synchronous wheel (20) at the ends of the two synchronous belts. The second synchronous belts (22) are connected to the second synchronous wheel (20) at the ends of the two synchronous belts. The second synchronous wheel (20) is connected to the second synchronous wheel (10) passing through the second synchronous wheel (21) via a coupling (23). A group of rollers (24) are provided between each two adjacent synchronous wheels (20) to prevent the synchronous belts (22) from contacting the outer sleeve (12).

7. The variable stiffness steering rod structure of a steering gear according to claim 6, characterized in that: The wire brace (19) is composed of a brace body (25) and a retaining ring (26); the lower edge of the brace body (25) is formed with an annular limiting plate extending outward; the outer wall of the brace body (25) is formed with a rib key strip (27) for interference connection with the inner wall of the synchronous wheel (20); the retaining ring (26) is interference-fitted on the upper end of the brace body (25); and the two annular plate supporting parts (18) are both located between the retaining ring (26) and the annular limiting plate.

8. The variable stiffness steering rod structure of a steering gear according to claim 3, characterized in that: The drive motor (9) is coaxially fixedly arranged on the inner side of the hollow outer shaft (4) through a star-shaped bracket (28); the outer side of the star-shaped bracket (28) is fixedly connected to the inner wall of the hollow outer shaft (4); the drive motor (9) is fixedly arranged in a vertical state at the center of the star-shaped bracket (28); the screw rod (10) is located above the drive motor (9); the lower end of the screw rod (10) is connected to the output shaft of the drive motor (9); the inner shaft (5) is located above the star-shaped bracket (28); a herringbone bearing frame (29) for connecting the upper end of the screw rod (10) is fixedly arranged on the inner side of the upper end of the hollow outer shaft (4); the herringbone bearing frame (29) is higher than the upper end of the strip-shaped through hole (6).

9. The variable stiffness steering rod structure of a steering gear according to claim 8, characterized in that: The inner shaft lifting mechanism is a herringbone bracket (30), which is coaxially fixed at the center of the lower end of the inner shaft rod (5), and a threaded hole matching the screw rod (10) is provided at the center of the herringbone bracket (30).

Images