JP2016075342A - Long structure member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long structure member capable of adding a damping structure with a sufficient space, in a case where a long structure member such as an axle shaft is constituted as a torsional damper.SOLUTION: A long structure member includes: a hollow outer shaft 3; a torsion bar 5 that is arranged at a shaft core part of the outer shaft 3, and of which one end part 7 is connected to one end part 9 of the outer shaft 3 in an integrally rotatable manner, and the other end part 11 can be rotated relatively to the other end part 13 of the outer shaft 3; and a damping connection part 15 that connects between the other end parts 13, 11 of the outer shaft 3 and torsion bar 5, and damps torsional operation of the torsion bar 5 to the outer shaft 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a long structural member used for an axle shaft or the like of an automobile.

In general, in shaft-like long structural members such as axle shafts described in Patent Documents 1 and 2, a torsional damper can be configured by forming it thin while maintaining a diameter that enables torque transmission, It is possible to greatly reduce the shock load due to a sudden start or a sudden shift of the transmission.

  However, since a structure that dampens the continuation of shaking back after shock absorption is required, it is impossible in terms of space.

JP 2014-125041 A JP 2014-163493 A

  The problem to be solved is that, when a long structural member such as an axle shaft is configured as a torsional damper, it is difficult to add a damping structure.

  The present invention is a shaft-like long structural member in order to allow a damping structure to be added without difficulty in space when a long structural member such as an axle shaft is configured as a torsional damper. A hollow outer shaft that transmits a damping torque, and an end portion of the outer shaft that is disposed at an axial center of the outer shaft so as to be integrally rotatable with one end portion of the outer shaft, and the other end portion of the outer shaft. A torsion bar that transmits a drive torque that can rotate relative to the end portion, and a damping coupling portion that is provided between the outer shaft and the torsion bar and that damps the twisting operation of the torsion bar with respect to the outer shaft. Features.

  Since the present invention is configured as described above, the amount of shock energy absorbed can be increased by the torsion bar. Due to the double structure of the outer shaft and the torsion bar, the damping coupling portion can be provided without difficulty in space, the torsional vibration of the torsion bar can be damped, and the untwisted torsional vibration can be converged early.

It is sectional drawing of an axle shaft. (Example) It is sectional drawing of an outer shaft. (Example) It is a side view of an outer shaft. (Example) It is sectional drawing of a torsion bar. (Example) (A) is a front view of an outer plate, (B) is a front view of an inner plate, and (C) is a front view of a stopper plate. (Example)

  When a long structural member such as an axle shaft is configured as a torsional damper, a hollow outer shaft that transmits a damping torque and the outer A torsion bar disposed at an axial center portion of the shaft for transmitting a main driving torque, and a damping coupling portion provided between the outer shaft and the torsion bar for damping a torsional operation of the torsion bar with respect to the outer shaft; It was realized.

  The damping coupling part may be a mechanism for damping by frictional force between multiple plates.

  The torsion bar is disposed so as to be axially movable relative to the outer shaft, an elastic body that generates an urging force in the axial direction is interposed between the outer shaft and the torsion bar, and the damping coupling portion is You may provide the outer plate and inner plate which are alternately arrange | positioned by engaging with the other end part of the said outer shaft and the other end part of the said torsion bar, and are fastened by the urging | biasing force of the said elastic body.

  FIG. 1 is a cross-sectional view of an axle shaft.

  In FIG. 1, an axle shaft 1 is applied as an example of a shaft-like long structural member. As the shaft-like long structural member, a propeller shaft, an extension shaft having a front engine rear drive structure, and the like can also be applied.

  The axle shaft 1 includes a hollow outer shaft 3 constituting the structure and a torsion bar 5 as an elastic portion. The outer shaft 3 transmits damping torque, and the torsion bar 5 transmits main driving torque as a driving member.

  The torsion bar 5 is disposed at the axial center portion of the outer shaft 3, and one end portion 7 is coupled to the one end portion 9 of the outer shaft 3 so as to be integrally rotatable. The other end 11 of the torsion bar 5 is configured to be rotatable relative to the other end 13 of the outer shaft 3.

  A damping coupling portion 15 is provided between the other end portions 13 and 11 of the outer shaft 3 and the torsion bar 5. In the present embodiment, the damping coupling portion 15 constitutes a coupling portion that couples the outer shaft 3 and the other end portions 13 and 11 of the torsion bar 5 so as to be relatively rotatable, and performs the twisting operation of the torsion bar 5 with respect to the outer shaft 3. Damping. However, the damping coupling portion 15 may be configured as a simple coupling portion and may have only a function of coupling the outer shaft 3 and the other end portions 13 and 11 of the torsion bar 5 so as to be relatively rotatable. The coupling portion may be configured so that the other end portion 11 of the outer shaft 3 is rotatably supported by the other end portion 11 of the torsion bar 5.

  A torsion bar 5 is disposed so as to be axially movable relative to the outer shaft 3, and a plurality of disc springs 17 are interposed between the outer shaft 3 and the torsion bar 5 as an elastic body that generates an urging force in the axial direction. ing.

  FIG. 2 is a cross-sectional view of the outer shaft, and FIG. 3 is a side view of the outer shaft.

  The outer shaft 3 of FIG. 2 is formed hollow by carbon steel for machine structure or the like, and a hexagonal fitting hole portion 18 is formed on the inner periphery of the one end portion 9 with respect to the intermediate portion 8 having a uniform diameter. The hexagonal fitting hole 18 is formed by a hole having a hexagonal cross section. The hexagonal fitting hole 18 is fitted into a hexagonal fitting shaft portion 29 described later, and transmits the rotation from the outer shaft 3 to the torsion bar 5 at one end portion 9. Other structures such as these can be employed as appropriate.

  An inlay portion 19 is formed on the inner periphery of the open end of the one end portion 9. A spline 21 is formed on the outer periphery of the one end portion 9. The spline 21 at the one end portion 9 is spline-fitted to an inner spline of a side gear of a differential device (not shown) so that torque can be transmitted from the differential device.

  As shown in FIGS. 2 and 3, the other end portion 13 of the outer shaft 3 is formed with an enlarged diameter portion 23 having an enlarged diameter. On the inner circumference of the enlarged diameter portion 23, a rotational engagement concave strip 23a is formed along the axial direction, and is equally disposed at six locations in the circumferential direction. On the inner peripheral back side of the enlarged diameter portion 23, two stopper locking projections 23b are provided in a 180 ° arrangement. Between the inner periphery of the enlarged diameter portion 23 and the intermediate portion 8 of the outer shaft 3, a shaft support portion 27 having a diameter larger than the inner diameter of the intermediate portion 8 and smaller than the inner diameter of the enlarged diameter portion 23 is formed.

  FIG. 4 is a cross-sectional view of the torsion bar.

  The torsion bar 5 of FIG. 4 is formed of, for example, spring steel, and a hexagonal fitting shaft portion 29 and a male screw portion 31 are sequentially formed at one end portion 7 with respect to the intermediate portion 25 having a uniform diameter. The hexagonal fitting shaft portion 29 has a hexagonal cross section. A square shaft portion 33 and a wheel coupling portion 35 are sequentially formed on the other end portion 11 of the torsion bar 5. The corner outer peripheral portion 33a of the square engagement shaft portion 33 has a curvature constituting a part of a circle so that the shaft support portion 27 is axially supported so as to be relatively rotatable.

  The square engaging shaft portion 33 has a quadrangular cross section. This square engagement shaft portion 33 is configured to fit an inner plate 45 (to be described later) so that the inner plate 45 rotates together with the torsion bar 5, and has other structures such as a spline, a key, and other polygon shafts. Can be adopted as appropriate.

  The wheel coupling portion 35 is formed with a flange portion 35a and a spline 35b.

  The torsion bar 5 is inserted into the outer shaft 3, and the hexagonal fitting shaft part 29 is fitted into the hexagonal fitting hole part 18 so that the integral rotation is possible. A corner outer peripheral portion 33 a of the square engagement shaft portion 33 is axially supported by the shaft support portion 27 so as to be relatively rotatable. In this state, the torsion bar 5 is configured to be movable relative to the outer shaft 3 in the axial direction.

  The male thread portion 31 protrudes outside the outer shaft 3. A spring seat 37 is fitted into the inlay portion 19 of the outer shaft 3, and the disc spring 17 is fastened to the spring seat 37 by a nut 41. By this fastening connection, the torsion bar 5 receives an urging force from the other end 13 side of the outer shaft 3 toward the one end 9 side.

  The damping coupling portion 15 is a mechanism that performs the damping by a frictional force between multiple plates. The damping coupling portion 15 is only required to be able to dampen the torsional operation of the torsion bar 5 with respect to the outer shaft 3, and is not limited to the frictional force between the multiple plates, but may be a cone clutch, a clutch using viscous fluid or magnetic fluid, and the like. A configuration may also be adopted in which a rubber for damping is fixed between the outer shaft 3 and the torsion bar 5. Further, the entire gap between the outer shaft 3 and the torsion bar 5 can be filled with a viscous fluid.

  The damping coupling portion 15 includes an outer plate 43 and an inner plate 45. The outer plate 43 and the inner plate 45 are alternately arranged to engage with the other end portion 13 of the outer shaft 3 and the other end portion 11 of the torsion bar 5, and are fastened by the biasing force of the disc spring 17. .

  5A is a front view of the outer plate, FIG. 5B is a front view of the inner plate, and FIG. 5C is a front view of the stopper plate.

  As shown in FIG. 5A, the outer plate 43 has six protrusions 43a on the outer periphery, and the inner periphery is a circular hole 43b. The hole 43 b has a diameter that is loosely fitted to the corner outer peripheral portion 33 a of the square shaft portion 33 of the torsion bar 5.

  As shown in FIG. 5B, the outer periphery of the inner plate 45 is formed in a circular shape and has an outer diameter that is loosely fitted to the inner periphery of the enlarged diameter portion 23. The inner periphery of the inner plate 45 is a square hole 45 a that fits into the square shaft portion 33. An oil hole 45 b is formed in the inner plate 45.

  As shown in FIG. 5 (C), the stopper plate 47 is provided with engaging projections 47a for stoppers at 180 ° positions at two locations on the outer periphery. The inner periphery of the stopper plate 47 is a square hole 47 b that fits into the square shaft portion 33.

  Then, the stopper plate 47 is fitted in the square shaft portion 33 through the square hole 47 b and is arranged on the back side in the enlarged diameter portion 23. With this arrangement, the engaging protrusion 47a corresponds to the position of the engaging protrusion 23b. The inner plate 45 and the outer plate 43 are alternately arranged in this order from the stopper plate 47 side. The inner plate 45 is fitted to the square shaft portion 33 by the square hole 45a, and the protrusion 43a of the outer plate 43 is the enlarged diameter portion 23. Engage with the recess 23a. The outer plate 43 at the outer end abuts on the flange portion 35a and receives the biasing force of the disc spring 17 through the flange portion 35a.

  Accordingly, the spline 21 at the one end portion 9 of the outer shaft 3 is spline-fitted to the inner spline of the side gear of the differential device (not shown), and the vehicle is mounted in the vehicle with the wheel (not shown) coupled to the wheel coupling portion 35. When a shock load is generated between the gear and the wheel, the other end portion 11 side of the torsion bar 5 is twisted with respect to the one end portion 7 side, and the shock load is absorbed by the torsional elastic force.

  At this time, torsional vibration with respect to the outer shaft 3 is generated in the torsion bar 5 by swinging back. In the damping coupling portion 15, the inner plate 45 rotates relative to the outer plate 43 and frictionally slides, and the outer shaft 3 transmits a damping torque to attenuate (dump) the torsional vibration of the torsion bar 5.

  When the torsion bar 5 is largely twisted, the engaging protrusion 47a of the stopper plate 47 is locked to the locking protrusion 23b of the outer shaft 3, and twisting beyond the setting is prevented.

  That is, the torsion bar 5 has a thin outer shape, reduces torsional rigidity, and the outer shaft 3 is disposed outside the torsion bar 5, and a damping coupling portion 15 is provided between the torsion bar 5 and the outer shaft 3 in the radial direction. Is.

  Further, by tightening the nut 41, the outer plate 43 and the inner plate 45 of the damping coupling portion 15 can increase the friction torque.

  The torsion bar 5 is twisted when shock torque is generated, accumulates shock energy, and transmits it to the wheel as a flat torque. At this time, the outer plate 43 and the inner plate 45 of the damping coupling portion 15 slide to absorb the swing back energy.

  Since the torsional rigidity of the axle shaft 1, that is, the spring constant does not change with the transmission torque and is constant, no shock is generated even with a large torque.

  Further, the axle shaft 1 is downstream of the final drive. Therefore, a small twist angle is equivalent to a large twist angle multiplied by the reduction ratio upstream of the final drive. In addition, the axle shaft 1 is long and has a large twist angle and has an internal / external double structure. As a result, the absorbable energy is much larger than when it is installed at other locations. Also, the damper can be easily provided without changing other components.

[Effect of Example]
An axle shaft 1 which is a torsional damper according to an embodiment of the present invention includes a hollow outer shaft 3 for transmitting damping torque, and an end portion 7 disposed at an axial center portion of the outer shaft 3 at one end portion 9 of the outer shaft 3. The torsion bar 5 that is coupled so as to be integrally rotatable and the other end 11 transmits a main drive torque that can rotate relative to the other end 13 of the outer shaft 3, and the other ends of the outer shaft 3 and the torsion bar 5 And a damping coupling portion 15 that couples the portions 13 and 11 so as to be relatively rotatable.

  For this reason, the absorption amount of shock energy can be increased by making the torsion bar 5 thinner by the structure of the outer shaft 3 and the torsion bar 5.

  The damping coupling portion 15 dampens the twisting operation of the torsion bar 5 with respect to the outer shaft 3.

  For this reason, the torsional vibration of the torsion bar 5 can be damped by the damping coupling portion 15 and the return energy can be converged at an early stage.

  The torsion bar 5 is disposed so as to be axially movable relative to the outer shaft 3, and a disc spring 17 that generates an urging force in the axial direction is interposed between the outer shaft 3 and the torsion bar 5, The damping coupling portion 15 is engaged with the other end portion 13 of the outer shaft 3 and the other end portion 11 of the torsion bar 5 and is alternately arranged and fastened by the urging force of the disc spring 17. 43 and an inner plate 45.

  Therefore, the torsion bar 5 is twisted with respect to the outer shaft 3 so that the outer plate 43 and the inner plate 45 are relatively rotated and frictionally slid to attenuate the return energy.

  In addition, the outer plate 43 and the inner plate 45 are disposed at the other end portion 11 on the opposite side to the one end portion 7 serving as the torsion base end of the torsion bar 5, so that they slide frictionally at a portion where the twisting operation is large. Therefore, a large damping effect can be obtained by the small damping coupling portion 15.

  For this reason, it is possible to greatly reduce the shock load due to sudden start of the drive member or sudden transmission shift, and a smaller gear or a thin shaft can be used.

  Therefore, it is possible to improve athletic performance and fuel consumption and reduce costs by reducing the vehicle weight.

  By using a multi-plate structure for the damping coupling part 15, the damping effect can be greatly changed.

  In limit running such as competition, a sudden torque change between the road surface and the tire may result in loss of grip and spin. Even in this case, since the shock torque disappears due to the damping effect, there is an effect that the limit speed is improved.

1 Axle shaft (long structure member)
DESCRIPTION OF SYMBOLS 3 Outer shaft 5 Torsion bar 7 One end part of torsion bar 9 One end part of outer shaft 11 Other end part of torsion bar 13 Other end part of outer shaft 15 Damping coupling part 17 Disc spring (elastic body)
43 Outer plate 45 Inner plate

Claims (3)

A shaft-like long structural member,
A hollow outer shaft that transmits damping torque;
One end of the outer shaft disposed at the axial center of the outer shaft is coupled to one end of the outer shaft so as to be integrally rotatable, and the other end has a driving torque that allows relative rotation with respect to the other end of the outer shaft. A torsion bar that communicates,
A damping coupling provided between the outer shaft and the torsion bar for damping the torsional motion of the torsion bar;
A long structural member characterized by comprising: The long structural member according to claim 1,
The damping coupling part is a mechanism for damping by frictional force between multiple plates.
A long structural member characterized by that. The long structural member according to claim 2,
The torsion bar is disposed so as to be axially movable relative to the outer shaft;
An elastic body that generates an urging force in the axial direction is interposed between the outer shaft and the torsion bar,
The damping coupling portion is engaged with the other end portion of the outer shaft and the other end portion of the torsion bar, respectively, and is alternately arranged and fastened by the urging force of the elastic body, and an inner plate,
A long structural member characterized by comprising:

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