JP2015137737A - intermediate shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate shaft capable of smoothly shrinking a middle shaft by increasing an extension amount of the middle shaft and reducing play in a rotation direction to improve a steering feeling.SOLUTION: An intermediate shaft 10 comprises a middle shaft 11, a first universal joint 70 provided at one end of the intermediate shaft 11, and a second universal joint 50 provided at the other end of the intermediate shaft 11. The middle shaft 11 comprises an inner cylindrical pipe member 30 coupled with the first universal joint 70, and a cylindrical outer pipe member 20 rotatably and shrinkably fitted with an outer periphery of the inner pipe member 30, and coupled with the second universal joint 50. One end of the coupling member 40 is rotatably and shrinkably fitted with an inner periphery of the inner pipe member 30, and the other end of the coupling member 40 is rotatably and shrinkably fitted with the inner periphery of the outer pipe member 20.

Description

  The present invention relates to an intermediate shaft that is telescopic and capable of transmitting rotation.

  An example of such an intermediate shaft is shown in Patent Document 1, for example.

  This consists of an intermediate shaft, a lower universal joint provided at one end of the intermediate shaft, and an upper universal joint provided at the other end of the intermediate shaft. The intermediate shaft is connected to the lower universal joint. A shaft member, an intermediate pipe member that is spline-fitted to the outer periphery of the shaft member, and an outer pipe member that is spline-fitted to the outer periphery of the intermediate pipe member and connected to the upper side universal joint. In this way, the spline fitting has a double structure, thereby increasing the amount of contraction of the intermediate shaft when the vehicle collides.

  The intermediate shaft of the intermediate shaft used in the power steering unit of the truck is a shaft member connected to the lower side universal joint, and an outer pipe member that is spline-fitted to the outer periphery of the shaft member and connected to the upper side universal joint It is made up of. When the cabin is tilted with respect to the chassis frame for vehicle maintenance, the outer pipe member on the cabin side extends relative to the shaft member on the chassis frame side.

  In order to improve vehicle maintainability, there is a demand to increase the tilt angle of the cabin, and it is conceivable to adopt a spline-fitting double structure as shown in Patent Document 1.

JP 2001-41255 A

  When the handle is operated, the play in the rotational direction exists between the outer pipe member and the intermediate pipe member, and exists between the intermediate pipe member and the shaft member, and the play increases as a whole, so that the steering feeling is not good. In addition, the intermediate pipe is inclined with respect to the shaft member, the outer pipe member is inclined with respect to the intermediate pipe, and the inclination of the outer pipe member on the shaft member is increased, so that the intermediate shaft is smoothly contracted in the event of a vehicle collision. There was a problem that it was difficult and caused great damage to the driver. If the play of the spline fitting portion is reduced, the play in the rotation direction and the inclination are reduced, but it is necessary to reduce the processing error of the spline fitting portion, which makes processing difficult. The present invention has been made in order to solve the above-described problems. The object of the present invention is to increase the extension amount of the intermediate shaft and reduce the backlash in the rotational direction to improve the steering feeling. It is to provide an intermediate shaft that can be smoothly contracted.

  The intermediate shaft according to claim 1 includes an intermediate shaft, a first universal joint provided at one end of the intermediate shaft, and a second universal joint provided at the other end of the intermediate shaft. A cylindrical inner pipe member connected to the first universal joint, and a cylindrical outer pipe member fitted to the outer periphery of the inner pipe member so as to be able to transmit and rotate and to be connected to the second universal joint. In the intermediate shaft consisting of: one end of the connecting member is fitted to the inner circumference of the inner pipe member so as to be able to rotate and extend, and the other end of the connecting member is sent to the inner circumference of the outer pipe member. It is characterized by being fitted so as to be extendable and extendable.

  According to the said structure, the expansion | extension amount of an intermediate shaft can be increased compared with the single structure of spline fitting. Compared to the spline-fitted double structure, the outer pipe member is directly fitted to the inner pipe member, which reduces the backlash in the rotational direction, improves the steering feeling, and allows the intermediate shaft to contract smoothly. it can.

  An intermediate shaft according to a second aspect of the present invention is the intermediate shaft according to the first aspect, wherein the inner pipe member has an extension resistance when extending one end of the connecting member on the inner periphery, and the outer pipe member is extended on the outer periphery of the inner pipe member. It is characterized by being larger than the elongation resistance at the time.

  According to the above configuration, the extension amount of the intermediate shaft can be increased. Since the outer pipe member is directly fitted to the inner pipe member, the play in the rotational direction can be reduced to improve the steering feeling, and the intermediate shaft can be contracted smoothly. Further, the outer pipe member can be extended to the outer periphery of the inner pipe member first, rather than extending one end of the connecting member to the inner periphery of the inner pipe member.

  An intermediate shaft according to a third aspect is the intermediate shaft according to the first or second aspect, wherein when the connecting member is extended with respect to the outer pipe member, a locking device that stops further extension is provided for the outer pipe member and the connecting member. It is characterized by being provided in between.

  According to the above configuration, the extension amount of the intermediate shaft can be increased. Since the outer pipe member is directly fitted to the inner pipe member, the play in the rotational direction can be reduced to improve the steering feeling, and the intermediate shaft can be contracted smoothly. Further, when the connecting member is extended with respect to the outer pipe member, the connecting member can be prevented from coming off from the outer pipe member.

  According to the configuration described above, the extension amount of the intermediate shaft can be increased. Since the outer pipe member is directly fitted to the inner pipe member, it is possible to provide an intermediate shaft capable of reducing the backlash in the rotational direction to improve the steering feeling and smoothly contracting the intermediate shaft.

It is a whole block diagram of the intermediate shaft concerning one Embodiment of this invention, and is also an expansion | extension state figure. FIG. 2 is a contraction state diagram of FIG. 1 according to an embodiment of the present invention. It is the expansion | extension state figure of FIG. 1 concerning one Embodiment of this invention.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  As shown in FIG. 1, the intermediate shaft 10 is rotationally connected to a power steering unit (not shown) at one end and is rotationally connected to a transfer gear device (not shown) at the other end. The power steering unit is fixed to the truck chassis frame side, and the transfer gear device is fixed to the truck cabin side. The cabin can be tilted with respect to the chassis frame during vehicle maintenance.

  The intermediate shaft 10 rotates in such a manner that the second universal joint 50 on the transfer gear device side, the first universal joint 70 on the power steering unit side, the second universal joint 50 and the first universal joint 70 can extend and contract in the axial direction. It has the intermediate shaft 11 connected so that transmission is possible. The intermediate shaft 10 has a function of transmitting the rotation of the transfer gear device to the power steering unit, and also has a function of absorbing an impact when the intermediate shaft 11 contracts when the vehicle (truck) collides.

  The second universal joint 50 includes a first yoke 55 that is rotationally coupled to the transfer gear device, a second yoke 52, and a cross shaft that pivotally couples the first yoke 55 and the second yoke 52 about two orthogonal axes. 51.

  The first yoke 55 is composed of a bifurcated portion and a shaft-shaped portion. A locking hole 53 is formed through the bifurcated portion in a radial direction. The cup 54 of the cross shaft 51 is fitted. On the inner periphery of the shaft-shaped portion, a female serration 56 is formed in the axial direction from the other end. The shaft-like portion is formed with a slit 57 penetrating in a radial direction from the outer periphery to the female serration 56 at one place on the circumference. The slit 57 is formed in the axial direction from the other end of the shaft-shaped portion. In the shaft-shaped portion, an insertion hole 59 is formed on one side with the slit 57 interposed therebetween, and a screw hole 58 is formed on the other side. A tightening bolt is inserted into the insertion hole 59, and the tightening bolt is screwed into the screw hole 58. When a part of the shaft-shaped part is tightened in the direction in which the width of the slit 57 is narrowed by the tightening bolt, the inner diameter of the female serration 56 is reduced, and the output shaft (not shown) of the transfer gear device is fastened and fixed to the shaft-shaped part. It has become so.

  The second yoke 52 includes a bifurcated portion and a shaft-shaped portion. A locking hole is formed through the bifurcated portion in the radial direction, and a cross is formed in the locking hole of the bifurcated portion. A cup 54 of the shaft 51 is fitted. An outer pipe member 20 of the intermediate shaft 11 is integrally formed at one end of the shaft-shaped portion.

  The cross shaft 51 includes a cross-shaped cross body, cylindrical rollers, and a cup 54. The cross body has four shaft portions arranged at equal intervals every 90 degrees, and the cup 54 has a cylindrical cup shape. The cup 54 is fitted in the locking hole 53 and is prevented from rotating. A plurality of cylindrical rollers are disposed between the cup 54 and the shaft portion, and the cross body is rotatably supported by the cup 54.

  The first universal joint 70 includes a third yoke 72, a fourth yoke 75 that is rotationally connected to the power steering unit, and a cross shaft that rotatably connects the third yoke 72 and the fourth yoke 75 about two orthogonal axes. 71.

  The fourth yoke 75 is composed of a bifurcated portion and a shaft-shaped portion. The bifurcated portion is formed with a locking hole 73 penetrating in the radial direction. The cup 74 of the cross shaft 71 is fitted. A female serration 76 is formed in the axial direction from one end on the inner periphery of the shaft-shaped portion. A slit 77 that penetrates from the outer periphery to the female serration 76 is formed at one place on the circumference of the shaft. The slit 77 is formed in the axial direction from the other end of the axial portion. An insertion hole 79 is formed on one side of the shaft-like portion with a slit 77 in between, and a screw hole is formed on the other side. A tightening bolt is inserted into the insertion hole 79, and the tightening bolt is screwed into the screw hole. When a part of the shaft-shaped part is tightened in the direction in which the width of the slit 77 is narrowed by the tightening bolt, the inner diameter of the female serration 76 is reduced, and the unillustrated input shaft of the power steering unit is fastened and fixed to the shaft-shaped part. It has become so.

  The third yoke 72 includes a bifurcated portion and a shaft-shaped portion. A locking hole is formed through the bifurcated portion in the radial direction, and a cross is formed in the locking hole of the bifurcated portion. A cup 54 of the shaft 51 is fitted. An inner pipe member 30 of the intermediate shaft 11 is integrally formed at the other end of the shaft-shaped portion.

  The intermediate shaft 11 is fitted into the cylindrical inner pipe member 30 integrally formed with the third yoke 72 and the outer periphery of the inner pipe member 30 so as to be able to transmit and rotate, and is integrally formed with the second yoke 52. One end of the cylindrical outer pipe member 20 and the inner pipe member 30 are fitted to the inner circumference of the inner pipe member 30 so as to be capable of rotational transmission and extendable, and the other end of the outer pipe member 20 is capable of rotational transmission and expansion and contraction. And a connecting member 40 fitted into the. The intermediate shaft 11 has a function of transmitting the rotation of the transfer gear device to the power steering unit, and also has a function of contracting at the time of a vehicle collision and absorbing an impact at the time of the collision.

  A first female serration 21 is formed on the inner periphery of the outer pipe member 20, a first male serration 31 is formed on the outer periphery of the inner pipe member 30, and the first male serration 31 is serrated on the first female serration 21. It is mated. The first female serration 21 and the first male serration 31 transmit the rotation of the outer pipe member 20 to the inner pipe member 30, and the first rotary expansion / contraction mechanism that fits the outer pipe member 20 to the inner pipe member 30 in an extendable manner. Is configured. A resin material is used on the surfaces of the first female serration 21 and the first male serration 31 that come into contact with each other to reduce sliding resistance.

  A second female serration 32 is formed on the inner periphery of the inner pipe member 30, and a second male serration 42 is formed on the outer periphery of the connecting member 40 from one end to the vicinity of the other end. A male serration 42 is serrated. The second female serration 32 and the second male serration 42 cause the connecting member 40 and the inner pipe member 30 to engage in the rotational direction, and the second rotating expansion / contraction mechanism that fits the connecting member 40 to the inner pipe member 30 in an extendable manner. Is configured. A resin material is used on the surfaces of the second female serration 32 and the second male serration 42 in contact with each other to reduce sliding resistance. The sliding resistance at the time of extension of the second rotation extension / contraction mechanism is set to be larger than the sliding resistance at the time of extension of the first rotation extension / contraction mechanism. Specifically, the second male serration 42 is press-fitted into the second female serration 32, and the first male serration 31 is fitted into the first female serration 21 with a gap.

  The other end of the connecting member 40 is expanded in the outer diameter direction. A third male serration 41 is formed on the outer periphery of the connecting member 40, and the third male serration 41 is serrated and fitted to the first female serration 21. The first female serration 21 and the third male serration 41 engage the outer pipe member 20 and the connecting member 40 in the rotational direction, and a third rotational extension / contraction mechanism that fits the outer pipe member 20 to the connecting member 40 so as to be extendable / contractable. Is configured.

  A storage hole 45 is formed in a radial direction at a portion of the other end of the connecting member 40 that is expanded in the outer diameter direction, and a compression spring 46 and a ball 47 are stored in the storage hole 45. A conical engagement hole 22 with which the ball 47 engages is formed on the inner periphery of one end of the outer pipe member 20. The storage hole 45, the compression spring 46, the ball 47, and the engagement hole 22 constitute a lock device that stops further extension when the connecting member 40 is extended with respect to the outer pipe member 20. . This locking device was provided in the radial direction between the outer pipe member 20 and the connecting member 40.

  Subsequently, the operation of the intermediate shaft 10 will be described based on the above-described configuration.

  When the vehicle is traveling, the ball 47 is located closer to the transfer gear device than in FIG. 1 and is not engaged with the engagement hole 22. The rotation of the handle (not shown) is transmitted to the first yoke 55 of the intermediate shaft 10 via the output shaft of the transfer gear device (not shown). Further, it is transmitted to the input shaft of the power steering unit (not shown) via the cross shaft 51, the second yoke 52, the outer pipe member 20, the inner pipe member 30, the third yoke 72, the cross shaft 51, and the fourth yoke 75. The rotation of the input shaft is power-assisted by the power steering unit and can change the direction of the steered wheels. Since the outer pipe member 20 is directly fitted to the inner pipe member 30, there is little play in the rotational direction as a whole, and a good steering feeling can be obtained.

  When the vehicle collides during traveling, the inner pipe member 30 and the connecting member 40 move to the transfer gear device side with respect to the outer pipe member 20, and are in the state shown in FIG. Thus, the impact at the time of collision can be absorbed. Since the outer pipe member 20 is directly fitted to the inner pipe member 30, the inner pipe member 30 is less inclined with respect to the outer pipe member 20 as a whole, and the inner pipe member 30 is smoothly contracted with respect to the outer pipe member 20. And it does not cause great damage to the driver.

  During vehicle maintenance, the unillustrated cabin is tilted with respect to the unillustrated chassis frame in the direction to open the unillustrated engine room. Since the power steering unit is fixed to the chassis frame side of the truck and the transfer gear device is fixed to the cabin side of the truck, the inner pipe member 30 and the connecting member 40 extend with respect to the outer pipe member 20, The ball 47 is engaged with the engagement hole 22 as shown in FIG. 1, and the inner pipe member 30 is further extended with respect to the connecting member 40 to the state shown in FIG. 3. Thus, the extension amount of the intermediate shaft 11 can be increased, the cabin tilt amount is increased, and the vehicle maintainability is improved. Since the inner pipe member 30 extends relative to the outer pipe member 20 before the inner pipe member 30 extends relative to the connecting member 40, the inner pipe member 30 comes out of both the outer pipe member 20 and the connecting member 40. There is no worry.

  When the vehicle maintenance is completed, the cabin (not shown) is tilted with respect to the chassis frame (not shown) in a direction to close the engine room (not shown). The inner pipe member 30 contracts with respect to the connecting member 40, the inner pipe member 30 engages with the connecting member 40 in the rotational direction, and the connecting member 40 engages with the outer pipe member 20 in the rotational direction. Therefore, the inner pipe member 30 is smoothly fitted to the outer pipe member 20 to be in the state shown in FIG. 1, the inner pipe member 30 and the connecting member 40 are contracted with respect to the outer pipe member 20, and the balls 47 are It is located at a position shifted to the transfer gear device side as compared with FIG. 1 and is not engaged with the engagement hole 22.

  For convenience of drawing, the first yoke 55, the outer pipe member 20, the inner pipe member 30, and the fourth yoke 75 are arranged coaxially with each other, but have a predetermined angle between the first yoke 55 and the outer pipe member 20. There is a predetermined angle between the inner pipe member 30 and the fourth yoke 75. As a result, since the fourth yoke 75 rotates at the same speed with respect to the first yoke 55, the second universal joint 50 and the first universal joint 70 have a predetermined phase difference in the rotation direction.

  The present invention is not limited to these embodiments, and can of course be implemented in various modes without departing from the gist of the present invention.

In the embodiment described above, the second universal joint 50 is rotationally connected to the transfer gear device, and the first universal joint 70 is rotationally connected to the power steering unit. As another embodiment, the second universal joint 50 may be rotationally connected to the power steering unit, and the first universal joint 70 may be rotationally connected to the transfer gear device.

  In the embodiment described above, the first female serration 21 is formed on the inner periphery of the outer pipe member 20, the first male serration 31 is formed on the outer periphery of the inner pipe member 30, and the second female serration is formed on the inner periphery of the inner pipe member 30. A serration 32 was formed, a second male serration 42 was formed on the outer periphery of one end of the connecting member 40, and a third male serration 41 was formed on the outer periphery of the portion of the other end of the connecting member 40 that was expanded in the outer diameter direction. As another embodiment, the selection is replaced with a spline, a first female spline is formed on the inner periphery of the outer pipe member 20, a first male spline is formed on the outer periphery of the inner pipe member 30, and A second female spline is formed on the inner periphery, a second male spline is formed on the outer periphery of one end of the connecting member 40, and a third male spline is formed on the outer periphery of the portion of the other end of the connecting member 40 that is expanded in the outer diameter direction. May be.

  In the embodiment described above, sliding resistance is generated between the outer pipe member 20 and the inner pipe member 30 by the first female serration 21 and the first male serration 31. As another embodiment, if a linear rolling bearing is used instead of the first female serration 21 and the first male serration 31, a rolling resistance is generated between the outer pipe member 20 and the inner pipe member 30. The general term for sliding resistance and rolling resistance was called extension resistance.

10: intermediate shaft, 11: intermediate shaft, 20: outer pipe member, 21: first female serration, 22: engagement hole (locking device), 30: inner pipe member, 31: first male serration, 32: first 2 female serrations, 40: connecting member, 41 third male serration, 42: second male serration, 45: storage hole (lock device), 46: compression spring (lock device), 47: ball (lock device), 50: Second universal joint, 70: first universal joint

Claims (3)

An intermediate shaft, a first universal joint provided at one end of the intermediate shaft, and a second universal joint provided at the other end of the intermediate shaft, the intermediate shaft being connected to the first universal joint In an intermediate shaft composed of an inner pipe member having a shape and a cylindrical outer pipe member connected to the second universal joint so as to be able to rotate and expand and contract on the outer periphery of the inner pipe member.
One end of a connecting member is fitted to the inner circumference of the inner pipe member so as to be able to rotate and extend, and the other end of the connecting member is fitted to the inner circumference of the outer pipe member so as to be able to send a rotation and extend and retract. The intermediate shaft is characterized by that. The extension resistance when extending one end of the connecting member to the inner periphery of the inner pipe member is larger than the extension resistance when extending the outer pipe member to the outer periphery of the inner pipe member. Item 8. The intermediate shaft according to Item 1. The locking device for stopping further extension when the connecting member is extended with respect to the outer pipe member is provided between the outer pipe member and the connecting member. Intermediate shaft.

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