Constant clearance mechanism for rack-and-pinion steering gear

Abstract

The utility model relates to a constant clearance mechanism for a rack-and-pinion steering gear. The constant clearance mechanism is structurally characterized in that a clearance reserving sub-assembly and a clearance keeping sub-assembly which are independent are sequentially arranged in an inner cavity of a threaded blanking cap from inside to outside; wherein the gap reserving sub-assembly is provided with a limiting piece, a sliding piece, a belleville spring and a positioning seat along the axis, and the sliding piece can axially slide back and forth in a reserved gap between the limiting piece and the positioning seat under the action of external thrust and the elastic force of the belleville spring; the gap keeping sub-assembly consists of a heightening sheet A, a torsional spring and a heightening sheet B; the front end of the threaded blanking cap is in positioning connection with the wave spring, the right end face of the threaded blanking cap is provided with an outer hexagonal boss, and the outer circumference of the threaded blanking cap is provided with external threads connected with the outside. The constant gap mechanism is composed of the gap reserving sub-assembly and the gap maintaining sub-assembly, so that the assembling efficiency of the whole mechanism is high, the problem that the steering gear generates abnormal noise can be effectively avoided, and the steering gear has excellent performance and consistency.

Description

TECHNICAL FIELD

[0001] The utility model relates to a constant gap mechanism for gear and rack type steering gear, is used for gear and rack type steering gear gear and rack meshing profile suitable side gap reservation and keep the constant of maximum side gap, belongs to a kind of automobile parts. BACKGROUND

[0002] Gear and rack type steering gear is widely used on automobile, with the increasing popularity of EPS electric steering gear, steering gear gear pair meshing abnormal noise problem is more prominent, which forms contrast with the development trend of driving comfort improvement, abnormal noise problem becomes the technical bottleneck of domestic steering gear, has not been well solved.

[0003] Due to the precision deterioration of parts, steering gear gear pair needs to reserve certain meshing gap, and the meshing gap is too small, the performance of steering gear is reduced, and the meshing gap is too large, the steering gear produces impact abnormal noise.

[0004] The suitable meshing gap of traditional steering gear gear pair needs to be adjusted according to the actual detection value of the gap and the performance test result of the steering gear, and needs to be adjusted repeatedly to achieve, and there are problems of unstable meshing gap detection, low precision, long adjustment period and the like.

[0005] Due to the working wear of parts, the problem of increasing meshing gap of gear pair in traditional steering gear is inevitable, and the initial meshing gap of steering gear is as small as possible by improving the machining precision of parts when leaving factory, so as to delay the early abnormal noise of steering gear, which is the common way in China, and the precision of parts is improved, so that the manufacturing cost of parts is greatly increased, and the abnormal noise problem of steering gear cannot be fundamentally solved.

[0006] Traditional steering gear does not have a control mechanism for increasing meshing gap, and the abnormal noise of steering gear caused by the too large meshing gap is inevitable, so that the actual working mileage of steering gear is reduced, and the design service life of steering gear is seriously deviated. SUMMARY

[0007] The utility model solves the technical problem to provide a constant gap mechanism for gear and rack type steering gear, the constant gap mechanism is composed of gap reservation subassembly and gap keeping subassembly;The gap reservation subassembly directly controls the maximum meshing gap of steering gear gear pair, is directly installed, and does not need to adjust the meshing gap again;The gap keeping subassembly can compensate the increased meshing gap due to the wear of parts, and continuously keep the stability of the maximum meshing gap of steering gear gear pair unchanged.

[0008] The utility model discloses a constant gap mechanism for gear and rack type steering gear, which comprises a threaded plug, an independent gap reserving subassembly and a gap maintaining subassembly arranged in the inner cavity of the threaded plug from inside to outside, wherein the gap reserving subassembly is provided with a limiting sheet, a sliding sheet, a disc spring and a positioning seat along an axis, and the sliding sheet can axially reciprocate within the reserved space of the limiting sheet and the positioning seat under the action of an external thrust and the elastic force of the disc spring; the gap maintaining subassembly is composed of a raised sheet A, a torsion spring and a raised sheet B, three annular inclined surfaces connected in a head-tail manner along a circumferential helix are arranged on the opposite surfaces of the raised sheet A and the raised sheet B, the torsion spring is located in the central groove of the raised sheet A and the raised sheet B, and the flat parts of the two ends of the torsion spring are clamped with the raised sheet A and the raised sheet B; the right end surface of the threaded plug is provided with an external hexagonal boss, and the outer periphery of the threaded plug is provided with an external thread connected with the outside.

[0009] The end surface of the positioning seat is provided with a small cylinder and an inclined surface cavity, the small cylinder is provided with a limiting table, the disc spring is located in the inclined surface cavity of the positioning seat, the limiting sheet is matched with the small cylinder, the left end of the small cylinder is provided with a riveting boss generated by a riveting process, the riveting boss limits the right end surface of the limiting sheet on the limiting table, and the right end surface of the limiting sheet is pressed on the left end surface of the sliding sheet.

[0010] The central parts of the raised sheet A and the raised sheet B are respectively provided with coaxial one-groove slots; during the assembly and debugging of the mechanism, a positioning rod is jointly inserted into the one-groove slots; the front half part of the positioning rod is provided with a flat square, and the flat square is inserted into all the one-groove slots; a left disc ring and a right disc ring are sequentially arranged in the middle part of the positioning rod, and the left disc ring passes through the external hexagonal boss and abuts against the right side of the raised sheet B, and the right disc ring is in contact with the counterbore groove of the inner hole of the external hexagonal boss.

[0011] During the actual work of the mechanism, the positioning rod is removed, and a plug is sealingly inserted into the inner hole of the external hexagonal boss.

[0012] The front end of the threaded plug is connected with a wave spring, and the front end surface of the sliding sheet is in contact with the bracket through the wave spring.

[0013] The right end surface of the positioning seat is provided with a circular table, the left end surface of the raised sheet A is provided with a positioning groove, and the circular table is seated in the positioning groove.

[0014] The constant gap mechanism for gear and rack type steering gear has the following advantages:

[0015] 1. The independent gap reserving subassembly and the gap maintaining subassembly can be preassembled, the height of the limiting table of the positioning seat is designed to ensure the reserved space of the sliding sheet, and the overall gap is constant, so that the gear and rack type steering gear can completely solve the problem of abnormal noise of gear pair engagement.

[0016] 2, the positioning seat small cylinder adopts riveting method, the reserved gap is ensured by the machining precision of parts, and there is no need to adjust again; the reserved gap of the gap reserving subassembly is convenient and fast to detect;

[0017] 3, the positioning rod adopts flat square, and the center of the gap maintaining subassembly adopts a slot, so that the relative position relationship of the gap maintaining subassembly is not changed during assembly; at the same time, the positioning rod adopts double-layer disc-shaped ring belt, which can play the role of axial positioning, so as to ensure the assembly precision;

[0018] 4, when the pre-assembly is completed, the positioning rod is pulled out, the through hole at the right end of the threaded plug is plugged and sealed, and the sealing performance of the internal environment is ensured;

[0019] 5, the waveform spring is arranged at the front end of the mechanism, when the whole mechanism runs, the wave crest of the waveform spring is higher than the front end surface of the sliding piece, so that the waveform spring is first contacted and pressed to deform before the front end surface of the sliding piece contacts the support seat. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the explosion view of the present application.

[0021] Figure 2 is the diagram of the positioning seat without riveting.

[0022] Figure 3 is the structure diagram of the gap reserving subassembly.

[0023] Figure 4 is the perspective view of the height increasing piece A or the height increasing piece B.

[0024] Figure 5 is the perspective view of the positioning rod.

[0025] Figure 6 is the perspective view of the threaded plug.

[0026] Figure 7 is the assembly view of the present application in the working state.

[0027] Figure 8 is the assembly schematic view of the present application in the working state. DETAILED DESCRIPTION

[0028] As Figures 1 to 3As shown, a constant gap mechanism for rack and pinion steering gear, independent gap reserving subassembly 10 and gap maintaining subassembly 20 are arranged in the inner cavity of threaded plug 9 from inside to outside; wherein gap reserving subassembly 10 is provided with limiting sheet 2, sliding sheet 3, disc spring 4 and positioning seat 5 along the axis, and sliding sheet 3 can axially reciprocate within the spacing 26 reserved by limiting sheet 2 and positioning seat 5 under the action of outer thrust and elastic force of disc spring 4; gap maintaining subassembly 20 is composed of raised sheet A 6, torsion spring 7 and raised sheet B 8, three circular inclined surfaces connected head to tail along the circumferential helix are arranged on the opposite surfaces of raised sheet A 6 and raised sheet B 8, and the corresponding parallel inclined surfaces of raised sheet A 6 and raised sheet B 8 are in contact; torsion spring 7 is located in the central groove of raised sheet A 6 and raised sheet B 8, and the flat parts of the two ends of torsion spring 7 are respectively clamped with raised sheet A 6 and raised sheet B 8, when the steering gear, rack and support have wear, the torsional force of torsion spring 7 will make raised sheet A 6 and raised sheet B 8 rotate relatively, and compensate the wear amount.

[0029] As shown in Figure 6 The right end surface of threaded plug 9 is provided with hexagonal boss 64, and the outer circumference of threaded plug 9 is provided with external thread connected with external parts. By rotating hexagonal boss 64 with wrench, threaded plug 9 is connected with external parts in thread.

[0030] As shown in Figure 2 and Figure 3 The end surface of positioning seat 5 has small cylinder 23 and inclined surface cavity 21, limiting table 22 is arranged on small cylinder 23, disc spring 4 is located in inclined surface cavity 21 of positioning seat 5, limiting sheet 2 is in clearance fit with small cylinder 23, the left end of small cylinder 23 is extended to form riveting boss 25 by riveting process, riveting boss 25 limits the right end surface of limiting sheet 2 on limiting table 22, and the right end surface of limiting sheet 2 is pressed on the left end surface of sliding sheet 3. The lower end surface of limiting sheet 2 contacts with the stepped shoulder of positioning seat 5 to stop moving, at this time, disc spring 4 stores elastic deformation energy due to compression deformation, and the upward elastic force of disc spring 4 makes sliding sheet 3 and limiting sheet 2 in contact, and the reserved spacing 26 is formed between the end surfaces of sliding sheet 3 and positioning seat 5, the size of reserved spacing 26 is determined by design size, and this spacing is the reserved gap of constant gap mechanism.

[0031] As shown in Figure 4 and Figure 5As shown, the center of the riser A6 and the riser B8 is provided with a coaxial slot 36; in the assembly and debugging process of the mechanism, the positioning rod 11 is inserted into the slot 36; the front half of the positioning rod 11 has a flat square 53, which is inserted into all the slots 36; the left disc ring belt 55 and the right disc ring belt 57 are sequentially arranged in the middle of the positioning rod 11, wherein the left disc ring belt 55 passes through the outer hexagonal boss 64 and abuts against the right side of the riser B8, and the right disc ring belt 57 is in contact with the counterbore groove in the inner hole of the outer hexagonal boss 64. In the assembly and debugging process of the mechanism, the positioning rod 11 is inserted into the slot 36, and the positioning rod 11 passes through the outer hexagonal boss 64, as shown in Figure 7 As shown in Figure 5 As shown, the flat square 53 of the positioning rod 11 is consistent with the shape of the inner hole of the slot 36, the flat square 53 is inserted into all the slots 36, and the flat square 53 of the positioning rod 11 restricts the relative rotation of the riser A6 and the riser B8; the left disc ring belt 55 and the right disc ring belt 57 are sequentially arranged in the middle of the positioning rod 11, wherein the left disc ring belt 55 passes through the outer hexagonal boss 64 and abuts against the right side of the riser B8, and the right disc ring belt 57 is in contact with the counterbore groove in the inner hole of the outer hexagonal boss 64. The positioning rod 11 is used to ensure that the relative position of the riser A6 and the riser B8 does not change during the assembly process. As shown in Figure 8 In actual work of the mechanism, the positioning rod 11 is removed, and the plug 12 is inserted into the inner hole of the outer hexagonal boss 64, so as to ensure the sealed operation of the mechanism.

[0032] The front end of the threaded plug 9 is connected with the wave spring 1, and the front end surface of the sliding piece 3 is in contact with the bracket through the wave spring 1. The wave spring 1 is first deformed, and a movement trend of the bracket away from the sliding piece 3 is generated, which is beneficial to the relative rotation of the riser A6 and the riser B8, and at the same time, a buffering effect is achieved, so as to reduce the rigid impact of the sliding piece.

[0033] As shown in Figure 1 And Figure 2 As shown, the right end surface of the positioning seat 5 is provided with a circular table 24, the left end surface of the riser A6 is provided with a positioning groove, and the circular table 24 is seated in the positioning groove. Thus, the concentricity of the gap reserving subassembly 10 and the gap maintaining subassembly 20 is ensured, and the matching precision is improved.

[0034] The working state of the rack and pinion steering gear of the present application is as follows: when the rack and pinion steering gear gear drives the rack to move linearly, due to the manufacturing precision deviation of the gear pair tooth part and the effect of the external force borne by the rack, the rack moves radially while moving linearly, pushing the holder to move axially outward along the horizontal hole of the shell, at the same time, pushing the sliding sheet 3 to slide in the direction of reducing the reserved gap in the gap reserving subassembly 10; when the rack stops moving, under the combined action of the elastic force of the wave spring 1 and the disc spring 4, the sliding sheet 3 slides in the direction of restoring the initial reserved gap, pushing the holder to move, promoting the gear and the rack gear pair tooth profile to fit;

[0035] When the radial movement distance of the rack is less than the reserved gap 26 in the gap reserving subassembly 10, the rack moves radially within the control range of the reserved gap 26; when the radial movement distance of the rack has a trend of being greater than the reserved gap 26 in the gap reserving subassembly 10, the sliding sheet 3 and the positioning seat 5 end face fit, the reserved gap is zero, rigidly limiting the rack from continuing to move radially, so that the maximum radial movement distance of the rack cannot exceed the reserved gap 26; the gap reserving subassembly 10 ensures that the maximum meshing side clearance of the gear pair of the rack and pinion steering gear is always working within the range controlled by the reserved gap 26, and the size of the reserved gap 26 is determined by product design and cannot produce abnormal noise of the steering gear gear pair meshing.

[0036] The working wear of the steering gear parts, the elastic force of the wave spring 1 pushes the steering gear holder to compress the steering gear rack, a gap is generated between the end face of the sliding sheet 3 and the steering gear holder, the height of the heightening sheet A6 and the heightening sheet B8 increases under the elastic torque of the torsion spring 7, the sliding sheet 3 and the end face of the steering gear holder re-fit to eliminate the gap; the gap maintaining subassembly 20 ensures that the new gap generated by the wear of the steering gear parts is automatically and timely eliminated.

Claims

1. A constant-velocity mechanism for rack-and-pinion steering gear, characterized by: The inner cavity of the threaded plug (9) is sequentially provided with an independent gap reserving subassembly (10) and a gap maintaining subassembly (20) from inside to outside; wherein the gap reserving subassembly (10) is respectively provided with a limiting sheet (2), a sliding sheet (3), a disc spring (4) and a positioning seat (5) along the axis, and the sliding sheet (3) can axially reciprocate within the spacing (26) reserved by the limiting sheet (2) and the positioning seat (5) under the action of the outer thrust and the elastic force of the disc spring (4); the gap maintaining subassembly (20) is composed of a raised sheet A (6), a torsion spring (7) and a raised sheet B (8), the opposite surfaces of the raised sheet A (6) and the raised sheet B (8) are respectively provided with three annular inclined surfaces connected in head-to-tail manner along the circumferential spiral, the torsion spring (7) is located in the central recess of the raised sheet A (6) and the raised sheet B (8), and the flat parts of the two ends of the torsion spring (7) are respectively connected with the raised sheet A (6) and the raised sheet B (8); the right end surface of the threaded plug (9) is provided with an outer hexagonal boss (64), and the outer circumference of the threaded plug (9) is provided with an outer thread connected with the outside.

2. A constant-gear mechanism for a rack and pinion steering gear according to claim 1, characterized in that: The end surface of the positioning seat (5) is provided with a small cylinder (23) and an inclined surface recess (21), the small cylinder (23) is provided with a limiting platform (22), the disc spring (4) is located in the inclined surface recess (21) of the positioning seat (5), the limiting sheet (2) is matched with the small cylinder (23), the left end of the small cylinder (23) is formed into a riveting boss (25) by using the riveting process, the riveting boss (25) limits the right end surface of the limiting sheet (2) on the limiting platform (22), and the right end surface of the limiting sheet (2) is pressed on the left end surface of the sliding sheet (3).

3. The constant-gear-gap mechanism for rack-and-pinion steering gear according to claim 1, characterized in that: The center of the raised sheet A (6) and the raised sheet B (8) is respectively provided with a coaxial slot (36); during the assembly and debugging of the mechanism, the positioning rod (11) is jointly inserted into the slot (36); the front half of the positioning rod (11) is provided with a flat square (53), the flat square (53) is inserted into all the slots (36); the left disc ring belt (55) and the right disc ring belt (57) are sequentially arranged in the middle part of the positioning rod (11), wherein the left disc ring belt (55) passes through the outer hexagonal boss (64) and abuts against the right side of the raised sheet B (8), and the right disc ring belt (57) is in contact with the counterbore groove of the inner hole of the outer hexagonal boss (64).

4. A constant-gear mechanism for a rack and pinion steering gear according to claim 3, characterized in that: During the actual work of the mechanism, the positioning rod (11) is removed, and the plug (12) is sealingly inserted into the inner hole of the outer hexagonal boss (64).

5. The constant-gear-gap mechanism for rack-and-pinion steering gear according to claim 1, characterized in that: The threaded plug (9) is positioned and connected with the wave spring (1) at the front end, and the front end surface of the sliding sheet (3) is in contact with the support through the wave spring (1).

6. The constant-gear-gap mechanism for rack-and-pinion steering gear according to claim 1, characterized in that: The right end surface of the positioning seat (5) is provided with a circular table (24), and the left end surface of the raised sheet A (6) is provided with a positioning recess, and the circular table (24) is seated in the positioning recess.

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