JP7119580B2 - Shaft connection structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a shaft connection structure that connects a first rotating shaft member and a second rotating shaft member by a universal joint using a positioning member that defines relative positions of the two rotating shaft members in the rotational direction.

Conventionally, for example, a rack-and-pinion type steering device includes a steering gear having a rack shaft extending in the vehicle width direction and a pinion shaft meshing with the rack shaft, a steering shaft coupled to the steering wheel, and a torque of the steering shaft. The pinion shaft and the intermediate shaft are connected by a universal joint such as a cross joint. The pinion shaft and the intermediate shaft are positioned so that the relative position (relative angular position) in the direction of rotation of the front wheels, which are the steered wheels, is zero when the steering wheel is in the neutral position. stipulated by The applicant of the present application has proposed a coupling device for such a steering device as disclosed in Patent Document 1.

The positioning member described in Patent Document 1 is made of resin and includes a first cylindrical portion fitted onto the pinion shaft and a second cylindrical portion fitted to a boss portion projecting from the shaft end surface of the pinion shaft. and a flat plate-like plate portion provided between the first cylindrical portion and the second cylindrical portion. On the other hand, the universal joint includes a first yoke as a first joint member fitted with serrations on the pinion shaft to restrict relative rotation with the pinion shaft, and a first yoke fitted with serrations on the intermediate shaft so as to rotate relative to the intermediate shaft. It has a fixed yoke as a second joint member whose rotation is restricted, and a cross shaft that oscillatably connects the first yoke and the fixed yoke. The plate portion of the positioning member engages with a serration groove formed on the outer peripheral surface of the pinion shaft at its pinion shaft side end portion.

The first yoke is formed with an axial slit at one location in the circumferential direction, and the first yoke is serrated-fitted to the pinion shaft so that the plate portion of the positioning member is accommodated in this slit. defines the relative position in the rotational direction between the pinion shaft and the intermediate shaft. The first yoke is formed with a bolt hole that intersects with the slit, and the first yoke is fastened to the pinion shaft by a bolt that is inserted through the bolt hole.

The plate portion of the positioning member is formed with a notch through which the bolt can pass, and when the first yoke is in a half-fitted state (incompletely fitted state) with respect to the pinion shaft, When the bolt is inserted into the bolt hole, the bolt interferes with the plate portion. As a result, the worker performing the assembly work can recognize that the first yoke is in the half-fitted state, and the fitting work of fitting the first yoke to the pinion shaft is redone to insert the bolt through the bolt hole. It is possible to reliably perform the fastening work of fastening the yoke 1 with a bolt.

JP 2014-141992 A

In the device disclosed in Patent Document 1, when a bolt is inserted into a bolt hole in a half-fitted state and the bolt interferes with a plate portion, the plate portion is pressed against the bolt along the plate thickness direction, and a cut in the plate portion occurs. A portion closer to the tip (second cylinder portion side) than the notch may be displaced in the circumferential direction of the pinion shaft. In this case, the serration groove engages with the portion of the plate portion on the distal end side of the cutout, and the serration groove engages with the portion of the plate portion on the base end side (first cylindrical portion side) of the cutout. In contrast, the plate portion is curved in the plate thickness direction (the circumferential direction of the pinion shaft). If the fitting operation is to be redone in this state, the curved portion of the plate portion interferes with the first yoke, making it impossible to perform the fitting operation. For this reason, the worker has to return the plate portion from the curved state to the original flat state and then perform the fitting work again, which is a heavy work load.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to facilitate re-fitting work when a bolt interferes with a plate portion of a positioning member when a joint member of a universal joint that connects rotary shaft members is in a half-fitted state. It is an object of the present invention to provide a shaft connection structure capable of shortening the assembly time and thus reducing the manufacturing cost.

In order to achieve the above objects, the present invention provides a shaft connection structure including a universal joint that connects a first rotary shaft member and a second rotary shaft member, and a positioning member , wherein the universal joint is , a first joint member fixed to the first rotating shaft member, a second joint member fixed to the second rotating shaft member, the first joint member and the second joint member and a linking member rockably linking the first rotating shaft member with a plurality of serration grooves formed on the outer peripheral surface of the end portion of the first rotating shaft member, and the first joint member comprising: It has a support portion that supports the connecting member, and a tubular portion into which the end portion of the first rotating shaft member is fitted, and the tubular portion has a plurality of serration teeth that engage with the plurality of serration grooves. A slit is formed in the inner peripheral surface in parallel with the axial direction , and a bolt hole that intersects the slit is formed. An annular ring portion having a plurality of serration teeth that engage with the plurality of serration grooves of the first rotating shaft member; The plate portion is formed so as to interfere with the bolt when the bolt is inserted into the bolt hole in a half-fitted state in which the fitting with the shaft member is insufficient . The end on the side close to the rotating shaft member is a thick portion formed thicker than the other end, and the thick portion is engaged with at least one of the plurality of serration grooves. The slit is formed so as to extend from the end face of the positioning member on the ring portion side of the cylinder portion toward the support portion side, and the bolt is inserted through the plate portion. A bolt insertion hole is formed through the plate thickness direction for
An interference portion of the plate portion that interferes with the bolt on the support portion side of the bolt insertion hole in the half-fitted state is formed to be thicker than a portion excluding the interference portion and the thick portion. , to provide a shaft coupling structure.

According to the shaft connection structure of the present invention, when the joint member of the universal joint that connects the rotary shaft members is in a half-fitted state, the bolt interferes with the plate portion of the positioning member. It becomes possible to easily carry out the assembly, and it is possible to shorten the assembly time and reduce the manufacturing cost.

1 is a schematic configuration diagram showing a steering device using a shaft connection structure according to a first embodiment of the present invention; FIG. It is an enlarged view showing a part of steering device. A first yoke and a positioning member are shown, (a) is a perspective view, (b) is a front view, (c) is a side view, and (d) is a rear view. (a) is a perspective view showing the positioning member 7 attached to the end of the pinion shaft, and (b) is a perspective view showing the positioning member alone. (a) is a cross-sectional view taken along the line AA of FIG. 3(b), and (b) is a cross-sectional view taken along the line BB of FIG. 3(b). It is an enlarged view which abbreviate|omits illustration of hatching and shows a part of Fig.5 (a). (a) is a cross-sectional view showing a state in which the cylindrical portion of the first yoke is completely fitted to the end portion of the pinion shaft and fixed with a bolt. (b) is a cross-sectional view showing a half-fitted state in which the cylindrical portion of the first yoke is not completely fitted to the end portion of the pinion shaft; (a) is a perspective view showing a positioning member according to a second embodiment, and (b) is a sectional view taken along line CC of (a).

[First embodiment]
An embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG. It should be noted that the embodiment described below is shown as a preferred specific example for carrying out the present invention, and there are portions that specifically illustrate various technically preferable technical matters. , the technical scope of the present invention is not limited to this specific embodiment.

FIG. 1 is a schematic configuration diagram showing a steering device using a shaft coupling structure according to a first embodiment of the invention. FIG. 2 is an enlarged view showing part of the steering device.

(Overall configuration of steering device)
The steering device 1 includes a steering gear 2 having a rack shaft 21 extending in the vehicle width direction and a pinion shaft 22 meshing with the rack shaft 21, a steering shaft 31 coupled to a steering wheel 30, and torque of the steering shaft 31. to the steering gear 2 , and a cylindrical steering column 33 supporting the steering shaft 31 . Rack shaft 21 is provided with rack teeth 211 arranged in parallel along its axial direction, and pinion teeth 221 that mesh with rack teeth 211 are provided on the outer peripheral surface of the lower end of pinion shaft 22 .

The rack shaft 21 is housed in a housing 23 fixed to the vehicle body except for both ends. Left and right tie rods 25 are connected to both ends of the rack shaft 21 protruding from the housing 23 via ball joints (not shown) disposed inside bellows 24 having a bellows structure. By moving in the vehicle width direction, the rack shaft 21 steers the left and right front wheels 11 , 11 as steerable wheels via the left and right tie rods 25 .

The steering device 1 also has a steering assist device 4 that assists the steering operation of the steering wheel 30 by the driver. In this embodiment, the steering assist device 4 is configured to reduce the torque of the electric motor 41 and apply it to the steering shaft 31 as a steering assist force. However, the steering assist device 4 is not limited to the electric type, and various configurations such as a hydraulic type can be used.

The intermediate shaft 32 transmits torque input from the steering shaft 31 to the pinion shaft 22 . The intermediate shaft 32 and the steering shaft 31 are connected by the universal joint 5 on the input side. The intermediate shaft 32 and the pinion shaft 22 are connected by the universal joint 6 on the output side. In this embodiment, the universal joints 5 and 6 on the input side and the output side are universal joints (also called cross joints). A ball-type constant velocity joint in which a plurality of balls are rotatably arranged may be used.

As shown in FIG. 2, the input-side universal joint 5 includes a first yoke 51 fixed to the steering shaft 31, a second yoke 52 fixed to the upper end of the intermediate shaft 32, the first yoke 51 and the second yoke 52 fixed to the upper end of the intermediate shaft 32. It has a cross-shaped spider 53 that oscillatably connects the two yokes 52 . The first yoke 51 is fastened and fixed to the steering shaft 31 by bolts 54 . Similarly, the output-side universal joint 6 includes a first yoke 61 fixed to the pinion shaft 22, a second yoke 62 fixed to the lower end of the intermediate shaft 32, and the first yoke 61 and the second yoke 62. and a cross-shaped spider 63 that is oscillatably linked. The first yoke 61 is fastened and fixed to the pinion shaft 22 with bolts 64 .

The connection between the intermediate shaft 32 and the pinion shaft 22 by the universal joint 6 on the output side is achieved by fixing the housing 23 of the steering gear 2 to the vehicle body and by connecting the steering shaft 31 to the intermediate shaft 32 by the universal joint 5 on the input side. This is done manually by an operator while being supported by the vehicle body via the steering column 33 . The intermediate shaft 32 and the pinion shaft 22 are positioned so that the steering angle of the front wheels 11, 11 is zero (straight ahead) when the steering wheel 30 is in the neutral position. angular position) is defined by the positioning member 7 .

Hereinafter, a shaft connection structure between the intermediate shaft 32 and the pinion shaft 22 using the positioning member 7 and the output side universal joint 6 will be described in detail. The first yoke 61, the second yoke 62, and the spider 63 of the output-side universal joint 6 correspond to the first joint member, the second joint member, and the linking member of the present invention, respectively. Further, the pinion shaft 22 corresponds to the first rotating shaft member of the present invention, and the intermediate shaft 32 corresponds to the second rotating shaft member of the present invention.

(Shaft connection structure)
3 shows the first yoke 61 and the positioning member 7, where (a) is a perspective view, (b) is a front view, (c) is a side view, and (d) is a rear view. In FIG. 3(c), the bolt holes 614 through which the bolts 64 are inserted are indicated by dashed lines. 4(a) is a perspective view showing the positioning member 7 attached to the end of the pinion shaft 22, and FIG. 4(b) is a perspective view showing the positioning member 7 alone. 5(a) is a cross-sectional view along line AA of FIG. 3(b), and FIG. 5(b) is a cross-sectional view along line BB of FIG. 3(b). FIG. 6 is an enlarged view showing part of FIG. 5(a) with hatching omitted.

As shown in FIG. 4A, a plurality of serration grooves 220 extending in the axial direction are formed on the outer peripheral surface of the end portion of the pinion shaft 22 to which the first yoke 61 is attached. In addition, an annular groove 222 having an arcuate cross-section is formed in the outer periphery of the pinion shaft 22 so that a portion of the bolt 64 in the circumferential direction passes therethrough. The annular groove 222 is formed along the entire circumference of the portion where the serration groove 220 is formed, and the serration groove 220 is axially divided by the annular groove 222 .

As shown in FIGS. 3A to 3D, the first yoke 61 includes a tubular portion 611 fitted and fixed to the end of the pinion shaft 22, and a support portion 612 that supports the spider 63. have as one. The support portion 612 is composed of a first arm 612a and a second arm 612b that are opposed to each other in a bifurcated manner, and a support hole that rotatably supports the shaft portion of the spider 63 is formed at each tip of the first arm 612a and the second arm 612b. 612c and 612d are formed.

A fitting hole 610 that accommodates the end of the pinion shaft 22 is formed in the tubular portion 611 . A plurality of serration teeth 610a are formed on the inner surface of the fitting hole 610 in parallel with the axial direction. The first yoke 61 is restricted from rotating relative to the pinion shaft 22 by engaging the serration teeth 610 a with the serration grooves 220 formed on the pinion shaft 22 .

The first yoke 61 has an end surface 611a (a surface facing a ring portion 71 of the positioning member 7 described later) on the side opposite to the support portion 612 in the axial direction of the cylindrical portion 611 so as to extend axially toward the support portion 612 side. A slit 613 is formed in the . The slit 613 is formed over the entire axial direction of the tubular portion 611 and a part of the first arm 612a on the tubular portion 611 side. The slit 613 is formed at one location in the circumferential direction of the tubular portion 611 by cutting, for example, and extends from the inner surface of the fitting hole 610 to the outer surface of the tubular portion 611 .

A bolt hole 614 that crosses the slit 613 is formed in the tubular portion 611 . The bolt hole 614 extends in a direction perpendicular to the slit 613 and penetrates the tubular portion 611 . The bolt hole 614 consists of a round hole 614 a on one side of the slit 613 and a screw hole 614 b on the other side of the slit 613 . The bolt 64 passes through the round hole 614a and the slit 613 and is screwed into the screw hole 614b. The first yoke 61 tightens the end of the pinion shaft 22 fitted in the fitting hole 610 by the axial force of the bolt 64 . The first yoke 61 is deformed by the axial force of the bolt 64 so that the width of the slit 613 is narrowed. 3(c) and 6, the central axis C1 of the bolt hole 614 is indicated by _a dashed line. 5A and 5B, the shape of the cylindrical portion 611 deformed by the axial force of the bolt 64 is indicated by a two-dot chain line, and the shape before deformation is indicated by a solid line.

The positioning member 7 includes an annular ring portion 71 arranged on the outer periphery of the pinion shaft 22 on the inner side (the inner side when viewed from the tip of the pinion shaft 22) relative to the first yoke 61, and an annular ring portion 71 provided on the tip surface of the pinion shaft 22. a retaining ring portion 72 fitted to the boss portion 223, a plate portion 73 accommodated in the slit 613 of the first yoke 61, and a reinforcing portion 74 provided between the ring portion 71 and the plate portion 73; integrally has The ring portion 71 and the retaining ring portion 72 are arranged in parallel in the axial direction of the pinion shaft 22 and bridged by the plate portion 73 .

The ring portion 71 is fitted onto the end of the pinion shaft 22 and has a plurality of serration teeth 71 a that engage with the serration grooves 220 of the pinion shaft 22 on its inner peripheral surface. The plurality of serration teeth 71 a of the ring portion 71 are engaged with the plurality of serration grooves 220 of the pinion shaft 22 below the cylindrical portion 611 of the first yoke 61 .

A portion of the plate portion 73 protrudes upward (toward the first arm 612a) beyond the retaining ring portion 72 . The length of the plate portion 73 in the direction along the axial direction of the intermediate shaft 32 is such that the entire length of the plate portion 73 is accommodated in the slit 613 of the first yoke 61. It has a length that cannot be accommodated in a slit 511 (indicated by a dashed line in FIG. 2) formed in 51 . As a result, in the event that an operator mistakenly positions the intermediate shaft 32 upside down and connects the intermediate shaft 32 to the steering shaft 31 via the universal joint 6 on the output side, the intermediate shaft 32 and the pinion shaft 22 are placed on the input side. Since the universal joint 5 cannot be used for connection, such erroneous assembly can be prevented.

The plate portion 73 is formed to have a plate thickness thicker at the end portion on the side closer to the pinion shaft 22 than at the other end portion. In the present embodiment, a thick portion 732 is provided at the end on the inner diameter side in the radial direction of the pinion shaft 22 , and the thickness of the thick portion 732 is greater than the diameter of the pinion shaft 22 . It is formed to be thicker than the main body portion 731 on the direction outer side. In the present embodiment, the thickness of the thick portion 732 is formed so as to gradually increase toward the pinion shaft 22 side. The inclination angle θ of the end face 732b of the thick portion 732 with respect to the radial direction of the pinion shaft 22 is, for example, 15°. Note that the thickness of the body portion 731 is uniform over its entirety.

As shown in _FIG . ₆ , when the thickness of the body portion 731 is T1 and the maximum thickness of the thick portion 732 is T2, T2 is preferably 1.3 to _{2.0 times} T1. . _In this embodiment, T2 is about _1.5 times T1. _When T2 is _{less than} 1.3 _times T1, the effect of increasing the rigidity of the thick portion 732 is not necessarily sufficient. This is because the rigidity of the body portion 731 is lowered. Also, the width W of the slit 613 in the natural state of the first yoke 61 is wider than T ₂ , and the first yoke 61 can be attached to the end of the pinion shaft 22 without interfering with the plate portion 73 . Due to the axial force of the bolt 64, the width W of the slit 613 is narrowed particularly at the end on the outer diameter side of the cylindrical portion 611, and the width W of the slit 613 does not change greatly at the end on the inner diameter side near the pinion shaft 22. . Therefore, even if the thick portion 732 is formed at the inner diameter side end portion of the plate portion 73 , the thick portion 732 is not sandwiched between the inner surfaces 613 a of the slit 613 . This configuration is designed so that the axial force of the bolt 64 acts as a tightening force that tightens the pinion shaft 22 by the cylindrical portion 611 of the first yoke 61 . The minimum width W ₀ (see FIG. 5A) of the slit 613 deformed by the axial force of the bolt 64 is larger than the thickness T ₁ of the body portion 731 and smaller than the maximum thickness T ₂ of the thick portion 732 .

Two serration teeth 732 a are continuously formed on the thick portion 732 of the plate portion 73 , and these two serration teeth 732 a are engaged with the serration grooves 220 of the pinion shaft 22 respectively. Two serration teeth 732 a are formed at both ends of the thick portion 732 in the thickness direction of the plate portion 73 . The configuration in which the plate portion 73 has two serration teeth 732 a is a configuration made possible by providing the plate portion 73 with the thick portion 732 .

Alternatively, only one serration tooth 732 a may be formed on the thick portion 732 and the serration tooth 732 a may be engaged with the serration groove 220 . Even in this case, since the rigidity of the plate portion 73 is increased by the thick portion 732, the effect of preventing the positional deviation of the plate portion 73, which will be described later, can be obtained. That is, at least one serration tooth 732 a that engages with at least one serration groove 220 among the plurality of serration grooves 220 should be formed in the thick portion 732 . However, if the thick portion 732 is formed with a plurality of serration teeth 732a, the effect of preventing the positional deviation of the plate portion 73 is further enhanced.

A bolt insertion hole 730 through which the bolt 64 is inserted is formed in the positioning member 7 so as to pass through the plate portion 73 in the plate thickness direction. The bolt insertion hole 730 is formed at a portion of the pinion shaft 22 corresponding to the annular groove 222 and opens toward the pinion shaft 22 .

Further, the positioning member 7 is arranged so that the plate portion 73 is positioned relative to the housing 23 in a state in which the axial position of the rack shaft 21 within the housing 23 is adjusted so that the steering angle of the front wheels 11, 11 is zero. is attached to the pinion shaft 22 so as to be at an angular position of . On the other hand, the first yoke 61 is attached to the intermediate shaft 32 so that the angular position of the slit 613 and the angular position of the steering wheel 30 satisfy a predetermined relationship. By fitting the cylindrical portion 611 of the first yoke 61 to the pinion shaft 22 so that the plate portion 73 is accommodated in the slit 613 and fixing it with the bolt 64, when the steering wheel 30 is in the neutral position, the front wheel can be moved. The steering device 1 is assembled so that the turning angles of the steering wheels 11, 11 are zero.

7A is a cross-sectional view showing a state in which the cylindrical portion 611 of the first yoke 61 is completely fitted to the end portion of the pinion shaft 22 and fixed by the bolt 64. FIG. In this completely fitted state, the bolt hole 614 of the first yoke 61 communicates with the bolt insertion hole 730 of the positioning member 7 and the annular groove 222 of the pinion shaft 22, and the bolt 64 is inserted through the round hole 614a of the bolt hole 614. can be screwed into the screw hole 614b.

FIG. 7(b) is a cross-sectional view showing a half-fitted state in which the cylindrical portion 611 of the first yoke 61 is not completely fitted to the end of the pinion shaft 22. As shown in FIG. In this half-fitted state, the bolt hole 614 of the first yoke 61 does not communicate with the bolt insertion hole 730 of the positioning member 7 and the annular groove 222 of the pinion shaft 22, and the bolt inserted into the round hole 614a of the bolt hole 614 does not communicate. 64 interferes with the plate portion 73 of the positioning member 7 . As a result, the operator who performs the assembly operation recognizes that the first yoke 61 is in the half-fitted state, and inserts the bolt 64 through the bolt hole 614 after performing the fitting operation again.

When the bolt 64 interferes with the plate portion 73 of the positioning member 7 in the half-fitted state, the plate portion 73 is pressed in its thickness direction. If the plate portion 73 at the portion closer to the retaining ring portion 72 than the bolt insertion hole 730 is displaced in the circumferential direction of the pinion shaft 22 by this pressing force, the plate portion 73 is bent, and the fitting operation must be redone. It may not be possible. Here, the displacement in the circumferential direction means that the inner diameter side end of the plate portion 73 (two serration teeth 732 a in this embodiment) is positioned between the retaining ring portion 72 side and the ring portion 71 side of the bolt insertion hole 730 . , are engaged with different serration grooves 220 respectively.

However, in the present embodiment, the end portion of the plate portion 73 on the pinion shaft 22 side is formed as the thick portion 732 and the rigidity is enhanced, so that the positional displacement described above is less likely to occur. Furthermore, in the present embodiment, a plurality of serration teeth 732a are formed on the thick portion 732, and each serration tooth 732a engages with a plurality of serration grooves 220 adjacent to each other in the circumferential direction of the pinion shaft 22. The positional deviation prevention effect of the portion 73 is further enhanced.

(Action and effect of the first embodiment)
According to the first embodiment of the present invention described above, the effect of improving the rigidity of the plate portion 73 by providing the thick portion 732 at the end portion on the inner diameter side of the plate portion 73, and the effect of improving the rigidity of the plate portion 73 and the thickness of the plurality of serration teeth 732a. Due to the effect of increasing the engaging portion with the pinion shaft 22 by being formed in the meat portion 732 , even if the plate portion 73 is pushed by the bolt 64 in the half-fitted state of the first yoke 61 , the bolt in the plate portion 73 is A portion closer to the retaining ring portion 72 than the insertion hole 730 is prevented from being displaced in the circumferential direction of the pinion shaft 22 . As a result, it is possible to easily re-do the fitting work, shorten the assembly time, and reduce the manufacturing cost.

[Second embodiment]
Next, a positioning member 7A according to a second embodiment of the invention will be described with reference to FIG. FIG. 8(a) is a perspective view showing a positioning member 7A according to the second embodiment, and FIG. 8(b) is a sectional view taken along line CC of FIG. 8(a). In FIG. 8(a), the same reference numerals as in FIG. 4(a) are assigned to the same components as those described for the positioning member 7 according to the first embodiment, and the description is duplicated. omitted. In addition, in the following description, the names and reference numerals of the parts such as the first yoke 61 described in the first embodiment are used.

In the positioning member 7A, the interfering portion of the plate portion 73 that interferes with the bolt 64 on the support portion 612 side of the bolt insertion hole 730 in the half-fitted state of the first yoke 61 is larger than the portion on the ring portion 71 side in the axial direction. is also thickly formed. In the present embodiment, a distal end portion 731a, which is an interference portion of the body portion 731 of the plate portion 73 projecting from the retaining ring portion 72 toward the first arm 612a, is formed thicker than the portion on the ring portion 71 side. ing. That is, the interference portion is formed thicker than the portion other than the interference portion and the thick portion 732 . In FIG. 8B, a portion of the plate portion 73 including the tip portion 731a is shown in cross section along the axial direction. _The thickness T3 of the tip portion 731a is the same as the maximum thickness T2 of the thick portion 732 _, for example.

Note that when the first yoke 61 is tightened to the pinion shaft 22 by the axial force of the bolt 64, the width of the slit 613 changes greatly near the end face 611a of the cylindrical portion 611, but near the end on the first arm 612a side. , the width reduction of the slit 613 is limited. Therefore, the tip portion 731 a is not caught between the inner surfaces 613 a of the slit 613 .

According to the present embodiment, the rigidity of the plate portion 73 is increased at the tip portion 731a, so that it is possible to more reliably prevent the bolt 64 from being inserted through the bolt hole 614 in the half-fitted state. Further, when the bolt 64 comes into contact with the tip portion 731 a in the half-fitted state, the deformation of the plate portion 73 inside the slit 613 is restricted by the contact of the tip portion 731 a with the inner surface 613 a of the slit 613 . As a result, the effect of preventing the positional deviation of the plate portion 73 can be further enhanced.

(Appendix)
Although the present invention has been described above based on the embodiments, these embodiments do not limit the invention according to the scope of claims. Also, it should be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

Moreover, the present invention can be modified appropriately without departing from the gist thereof. For example, in the above-described embodiment, the thickness of the plate portion 73 gradually increases toward the pinion shaft 22 side of the thick portion 732 . can be That is, the plate portion 73 may be formed so that the end portion on the side close to the pinion shaft 22 is thicker than the end portion on the other side.

Further, in the above-described embodiment, a case where the shaft connection structure of the present invention is applied to the steering device 1 of a vehicle has been described, but the present invention is not limited to this, and a pair of rotating shaft members define their relative positions in the rotating direction. It is possible to apply the present invention to various devices that are connected by a universal joint using a positioning member that

22... Pinion shaft (first rotary shaft member) 220... Serration groove 32... Intermediate shaft (second rotary shaft member) 6... Output side universal joint (universal joint)
61... First yoke (first joint member) 611... Cylindrical portion 611a... End face 612... Support portion 613... Slit 614... Bolt hole 62... Second yoke (second joint member) 63... Spider (connecting member)
7, 7A... Positioning member 71... Ring part 71a... Serration tooth 73... Plate part 730... Bolt insertion hole 731a... Tip part (interference part)
732... Thick portion (inner diameter side end) 732a... Serration tooth

Claims (2)

A shaft connection structure including a universal joint that connects a first rotation shaft member and a second rotation shaft member, and a positioning member ,
The universal joint includes a first joint member fixed to the first rotating shaft member, a second joint member fixed to the second rotating shaft member, the first joint member and the second joint member. and a linking member that rockably links the two joint members,
The first rotating shaft member has a plurality of serration grooves formed on the outer peripheral surface of the end thereof,
The first joint member has a support portion that supports the connecting member, and a tubular portion into which the end portion of the first rotating shaft member is fitted,
The cylindrical portion has a plurality of serration teeth on its inner peripheral surface that engage with the plurality of serration grooves, slits extending parallel to the axial direction , and bolt holes that intersect the slits. cage,
The positioning member includes an annular ring portion having a plurality of serration teeth that engage with the plurality of serration grooves of the first rotating shaft member on the back side of the first joint member, and is accommodated in the slit. When a bolt is inserted into the bolt hole in a half-fitted state in which the tubular portion and the first rotating shaft member are not sufficiently fitted, the plate portion is attached to the bolt. formed to interfere,
The plate portion has a thick portion formed such that an end portion on a side close to the first rotating shaft member is thicker than an end portion on the other side, and the thick portion has the plurality of serration grooves. has at least one serrated tooth that engages at least one of
The slit is formed so as to extend from an end face of the positioning member on the ring portion side of the cylinder portion toward the support portion side,
A bolt insertion hole for inserting the bolt is formed through the plate portion in a plate thickness direction,
An interference portion of the plate portion that interferes with the bolt on the support portion side of the bolt insertion hole in the half-fitted state is formed to be thicker than a portion excluding the interference portion and the thick portion. ,
Axial connection structure. The plate portion has a plurality of serration teeth in the thick portion,
The shaft connection structure according to claim 1.

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