JP7115009B2 - intermediate shaft - Google Patents

Description

The present invention relates to an intermediate shaft.

Generally, in an automobile, a steering shaft connected to a steering wheel and, for example, a pinion shaft as a steering gear shaft are connected via an intermediate shaft. The sleeve and shaft of the intermediate shaft are made telescopic by employing, for example, a telescopic shaft provided with ball grooves and balls (see, for example, Patent Document 1).

Also, the other end of the sleeve is directly joined to a yoke forming part of a universal joint connected to the pinion shaft, or directly joined to a tube interposed between the yoke and the yoke.

JP 2010-53943 A

In the intermediate shaft, there is a risk that the joint between the connecting member such as the yoke or tube and the sleeve will deteriorate. Deterioration of the joint contributes to positional displacement between the connecting member and the sleeve.

SUMMARY OF THE INVENTION An object of the present invention is to provide an intermediate shaft that can stably maintain the joint between a sleeve and a connecting member for a long period of time.

In order to solve the above-described problems, an intermediate shaft according to one aspect of the present invention provides a sleeve having a ball groove along the axial direction on its inner peripheral surface; a connecting member joined to one end of the sleeve; A crimped portion formed by crimping at least one of the one end portion of the sleeve and the connecting member is provided, and the crimped portion is arranged at different positions in the circumferential direction with respect to the ball groove.

According to the intermediate shaft of the present invention, the joint between the sleeve and the connecting member can be stably maintained for a long period of time.

FIG. 4 is a schematic diagram showing an example of a usage pattern of the intermediate shaft according to the embodiment; 1 is a perspective view showing a schematic configuration of an intermediate shaft according to an embodiment; FIG. FIG. 4 is an exploded perspective view showing an outer shaft and a tube provided in the intermediate shaft according to the embodiment; FIG. 4 is a plan view showing the shape of the other end of the tube according to the embodiment; 4 is a cross-sectional view of one end of the outer shaft according to the embodiment; FIG. 4 is a plan view showing the shape of one end of the outer shaft according to the embodiment; FIG. FIG. 4 is a cross-sectional view showing a state immediately after assembly of the other end portion of the tube and the one end portion of the outer shaft according to the embodiment; FIG. 8 is a cross-sectional view of a cut plane including the VIII-VIII cut line in FIG. 7; FIG. 8 is a cross-sectional view of a cut plane including the IX-IX cutting line in FIG. 7; FIG. 10 is a cross-sectional view showing a state after caulking of the other end of the tube and the one end of the outer shaft according to the embodiment.

Hereinafter, embodiments will be specifically described with reference to the drawings. It should be noted that the embodiments described below are all comprehensive or specific examples. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept will be described as arbitrary constituent elements.

In addition, the drawings are schematic diagrams in which emphasis, omissions, and ratios are appropriately adjusted in order to illustrate the present invention, and may differ from actual shapes, positional relationships, and ratios.

FIG. 1 is a schematic diagram showing an example of how an intermediate shaft 100 according to the embodiment is used. As shown in FIG. 1, an intermediate shaft 100 is provided in a steering device 10 of an automobile. Specifically, the steering device 10 includes a steering shaft 12 having one end connected to a steering wheel 11, and a steering mechanism 16 for steering steerable wheels 15. The steering mechanism 16 includes a rack and pinion mechanism including a pinion shaft 13 and a rack shaft 14. and an intermediate shaft 100 interposed between the steering shaft 12 and the pinion shaft 13 to transmit steering torque.

One end of intermediate shaft 100 is connected to steering shaft 12 via first universal joint 17 . The other end of intermediate shaft 100 is connected to pinion shaft 13 via second universal joint 18 .

When the steering wheel 11 is operated to rotate the steering shaft 12 , the rotation is transmitted to the pinion shaft 13 and the rack shaft 14 via the intermediate shaft 100 . Thereby, the steering mechanism 16 steers the steered wheels 15 .

Next, intermediate shaft 100 according to the present embodiment will be described in detail. FIG. 2 is a perspective view showing a schematic configuration of intermediate shaft 100 according to the embodiment. FIG. 3 is an exploded perspective view showing outer shaft 140 and tube 160 provided in intermediate shaft 100 according to the embodiment. 2 and subsequent drawings, an orthogonal coordinate system is used in which the X-axis direction is the axial direction of the intermediate shaft 100. As shown in FIG. That is, the Y-axis direction and the Z-axis direction, which are orthogonal to each other, are also orthogonal to the X-axis direction. In the following description, the end on the negative side in the X-axis direction is called one end, and the end on the positive side in the X-axis direction is called the other end.

As shown in FIG. 2, the intermediate shaft 100 includes an extendable intermediate shaft 110, a first universal joint 17 provided at the other end of the intermediate shaft 110, and a second universal joint 17 provided at one end of the intermediate shaft 110. A universal joint 18 is provided. The intermediate shaft 110 has an outer shaft 140 , an inner shaft 150 and a tube 160 .

As shown in FIGS. 2 and 3 , the outer shaft 140 is an example of a sleeve that is arranged between the inner shaft 150 and the tube 160 and connects the inner shaft 150 and the tube 160 .

The outer shaft 140 is a cylindrical shaft and has a through hole 141 . The inner shaft 150 is inserted into the other end of the outer shaft 140 from the positive side in the X-axis direction. A pair of ball grooves 142 extending in the X-axis direction are formed on the inner peripheral surface of the outer shaft 140 (see FIG. 6). The inner peripheral surface of the ball groove 142 is a concave curved surface when viewed in the X-axis direction. The pair of ball grooves 142 face each other in the Z-axis direction.

The inner shaft 150 is a shaft body, and the first universal joint 17 is provided at the other end. The first universal joint 17 includes a first yoke 171 connected to the inner shaft 150, a second yoke 172 connected to the steering shaft 12, and a cross shaft 173 connecting the first yoke 171 and the second yoke 172. including. Each shaft portion of the cross shaft 173 is rotatably supported by each arm of the first yoke 171 and the second yoke 172 via bearings (not shown).

A pair of ball grooves 151 extending in the X-axis direction are formed on the outer peripheral surface of the inner shaft 150 (see FIG. 6). The inner peripheral surface of the ball groove 151 is a concave curved surface when viewed in the X-axis direction. A pair of ball grooves 151 face each other in the Z-axis direction. That is, when the inner shaft 150 is inserted into the outer shaft 140 and assembled, the ball grooves 142 and 151 face each other in the Z-axis direction. A space formed by the ball grooves 142 and 151 has a substantially circular shape when viewed in the X-axis direction. A plurality of balls B arranged in the X-axis direction are arranged in this space. Since the plurality of balls B slide in the ball grooves 142 and 151, the inner shaft 150 and the outer shaft 140 can smoothly expand and contract in the X-axis direction. The outer shaft 140 and the inner shaft 150 are provided with a structure that restricts the ball B from coming off. Specifically, a lid 147 is attached to the other end of the outer shaft 140 . The cover 147 is formed with a through hole 148 for allowing the inner shaft 150 to slide, and a wall portion 149 for restricting the ball B from coming off. A stopper member (not shown) is provided at one end of the inner shaft 150 to prevent the ball B from coming off.

Tube 160 is an example of a connecting member joined to one end of outer shaft 140 . The tube 160 is a cylindrical shaft and has a through hole 162 . A second universal joint 18 is provided at one end of the tube 160 . The second universal joint 18 includes a first yoke 181 connected to the tube 160, a second yoke 182 connected to the pinion shaft 13, and a cross shaft 183 connecting the first yoke 181 and the second yoke 182. include. Each shaft portion of the cross shaft 183 is rotatably supported by each arm of the first yoke 181 and the second yoke 182 via bearings (not shown).

The other end of tube 160 is joined to one end of outer shaft 140 . A joint structure between the tube 160 and the outer shaft 140 will be described below. Specifically, the convex portion 161 provided at the other end portion of the tube 160 and the fitting portion 144 provided at one end portion of the outer shaft 140 are fitted and welded together to form the tube 160 and the outer shaft. 140 are joined.

First, the other end of tube 160 will be described in detail. FIG. 4 is a plan view showing the shape of the other end of tube 160 according to the embodiment. As shown in FIGS. 3 and 4, the other end of the tube 160 is provided with a pedestal 163 and a projection 161 .

The pedestal portion 163 is an annular portion having an outer diameter smaller than that of the outer peripheral surface of the tube 160, and supports the convex portion 161 on its tip end surface. When viewed in the X-axis direction, the circle formed by the outer peripheral surface of the tube 160 and the circular shape formed by the outer peripheral surface of the pedestal portion 163 are concentric. Therefore, the outer peripheral surface of the tube 160 and the outer peripheral surface of the pedestal portion 163 are formed with a uniform stepped portion 164 over the entire circumference.

The convex portion 161 is elongated in the Y-axis direction when viewed in the X-axis direction. Specifically, the convex portion 161 is formed in an oblong annular shape elongated in the Y-axis direction. A pair of long side portions 161a of the convex portion 161 are arranged in the Z-axis direction with the through hole 162 interposed therebetween. A pair of short side portions 161b of the convex portion 161 are arranged in the Y-axis direction with the through hole 162 interposed therebetween. A pair of short side portions 161 b of the convex portion 161 are each formed with a concave portion 165 on the outer peripheral surface thereof. The pair of recesses 165 are arranged in the X-axis direction with the through hole 162 interposed therebetween. That is, the pair of recesses 165 are arranged evenly in the circumferential direction. Further, the convex portion 161 is housed within the pedestal portion 163 when viewed in the X-axis direction.

Next, one end of the outer shaft 140 will be described in detail. FIG. 5 is a cross-sectional view of one end of the outer shaft 140 according to the embodiment. FIG. 6 is a plan view showing the shape of one end of the outer shaft 140 according to the embodiment. 5 is a cross-sectional view of a cross section including the VV cutting line in FIG. 6. As shown in FIG. 6, the outer shape of the inner shaft 150 is indicated by broken lines, and the outer shape of the ball B is indicated by two-dot chain lines.

As shown in FIGS. 5 and 6, one end of the outer shaft 140 is provided with a guide portion 143 and a fitting portion 144 . The guide portion 143 is a portion that guides the pedestal portion 163 of the tube 160 to a predetermined position during assembly. Specifically, the guide portion 143 is formed in an annular shape, and slides and guides the pedestal portion 163 on its inner peripheral surface. Since the stepped portion 164 of the tube 160 abuts against the distal end surface of the guide portion 143 , further entry of the convex portion 161 is restricted.

The fitting portion 144 is a portion into which the convex portion 161 of the tube 160 is fitted. The fitting portion 144 is a portion arranged on the positive side in the X-axis direction with respect to the guide portion 143 . The fitting portion 144 is provided continuously to the other end of the tube 160, but the portion where the convex portion 161 is fitted is only a portion on the tip side.

The fitting portion 144 is formed in an annular shape, and its inner peripheral surface is formed in a substantially oval shape elongated in the Y-axis direction. A pair of long side portions 144a of the fitting portion 144 are arranged in the Z-axis direction with the through hole 141 interposed therebetween. A pair of short side portions 144b of the fitting portion 144 are arranged in the Y-axis direction with the through hole 141 interposed therebetween. The short side portion 144 b has the same thickness as the guide portion 143 . On the other hand, the long side portion 144 a is formed thicker than the guide portion 143 . A ball groove 142 is formed for each of the pair of long side portions 144a. A pair of flat portions 146 are formed on each of the pair of long side portions 144 a so as to sandwich the ball groove 142 in the circumferential direction and contact the convex portion 161 .

Next, a method for assembling the tube 160 and the outer shaft 140 will be described. Here, the case where an operator assembles the tube 160 and the outer shaft 140 is exemplified, but the tube 160 and the outer shaft 140 may be automatically assembled by an assembling device. Even in that case, the tube 160 and the outer shaft 140 are assembled in the same procedure.

First, the operator assembles the other end of tube 160 to one end of outer shaft 140 . Specifically, the operator inserts the convex portion 161 and the base portion 163 of the tube 160 into the through hole 141 from the one end side of the outer shaft 140 . As a result, the pedestal portion 163 slides on the inner peripheral surface of the guide portion 143 until the distal end surface of the guide portion 143 comes into contact with the stepped portion 164 of the tube 160, and the convex portion 161 is fitted into the fitting portion 144. do.

FIG. 7 is a cross-sectional view showing a state immediately after the other end of tube 160 and one end of outer shaft 140 are assembled together according to the embodiment. FIG. 8 is a cross-sectional view of a cut plane including the VIII-VIII cut line in FIG. FIG. 9 is a cross-sectional view of a cut plane including the IX-IX cut line in FIG. FIG. 7 is a cross-sectional view taken along the line VII-VII in FIGS. 8 and 9, showing a fitting state between the convex portion 161 of the tube 160 and the fitting portion 144 of the outer shaft 140. FIG. ing.

As shown in FIGS. 7 to 9, the pair of long side portions 161a of the convex portion 161 are in contact with the pair of long side portions 144a of the fitting portion 144, respectively, and the pair of short side portions of the convex portion 161 are in contact with each other. 161b are in contact with the pair of short side portions 144b of the fitting portion 144, respectively. Specifically, the pair of long side portions 144 a of the convex portion 161 are in surface contact with the planar portion 146 of the fitting portion 144 . Therefore, even if the tube 160 rotates, the outer shaft 140 also rotates without idling.

In addition, since the short side portion 161b of the convex portion 161 has the concave portion 165 immediately after the fitting, a gap is formed between the short side portion 161b of the convex portion 161 and the short side portion 144b of the fitting portion 144. It is The pair of recesses 165 are arranged at different positions in the circumferential direction with respect to the pair of ball grooves 142 of the outer shaft 140 . Specifically, the direction in which the pair of protrusions 161 are aligned (the Y-axis direction in this embodiment) is perpendicular to the direction in which the pair of ball grooves 142 are aligned (the Z-axis direction in this embodiment). It's becoming

Next, the worker joins the outer shaft 140 to the tube 160 by crimping one end of the outer shaft 140 . FIG. 10 is a cross-sectional view showing a state after caulking of the other end of tube 160 and one end of outer shaft 140 according to the embodiment. FIG. 10 is a diagram corresponding to FIG.

Specifically, the operator forms the crimped portion 200 by crimping the portion of the outer shaft 140 facing the recess 165 . In the present embodiment, since the crimped portion 200 is provided for each of the pair of recesses 165, the number of crimped portions 200 is two. Therefore, the two crimped portions 200 are arranged in the Y-axis direction. That is, the two crimped portions 200 are evenly arranged in the circumferential direction. Further, the crimped portion 200 is plastically deformed by crimping and fitted into the concave portion 165, and becomes recessed from other portions after crimping. Since the crimped portion 200 is fitted into the concave portion 165 in this manner, the outer shaft 140 and the tube 160 can be firmly joined.

In the crimping process, a plurality of crimped portions 200 may be formed simultaneously using a jig or the like, or the crimped portions 200 may be formed one by one while rotating the outer shaft 140 and the tube 160 .

Next, the operator welds one end of outer shaft 140 and the other end of tube 160 to complete assembly of tube 160 and outer shaft 140 .

As described above, the intermediate shaft 100 according to the present embodiment includes the outer shaft 140 (sleeve) having the ball groove 142 along the X-axis direction (axial direction) on the inner peripheral surface, and one end portion of the outer shaft 140. and a crimped portion 200 formed by crimping at least one of one end of the outer shaft 140 and the tube 160, and the crimped portion 200 is formed by the ball groove 142 are arranged at different positions in the circumferential direction.

According to this, since the crimped portion 200 is formed by crimping at least one of the one end portion of the outer shaft 140 and the tube 160, for example, even if the weld is broken and the joint by welding is released, Also, the connection by the crimped portion 200 can be maintained. That is, since the double joint structure is adopted, the joint between the outer shaft 140 and the tube 160 can be stably maintained for a long period of time.

Moreover, since the crimped portion 200 is arranged at a different position in the circumferential direction with respect to the ball groove 142, deformation of the ball groove 142 of the outer shaft 140 due to crimping can be suppressed. Therefore, the expansion and contraction of the inner shaft 150 and the outer shaft 140 can be stabilized.

Further, since the tube 160 is provided between the first yoke 181 and the outer shaft 140, the intermediate shaft 110 can be made longer. By selecting and using tubes 160 of different lengths, it is also possible to make the intermediate shaft 110 any length.

One end of the outer shaft 140 is provided with a convex portion 161 projecting in the X-axis direction, and the tube 160 is provided with a fitting portion 144 into which the convex portion 161 is fitted. The fitting portion 144 is non-circular when viewed in the X-axis direction.

According to this, since the convex portion 161 and the fitting portion 144 are non-circular when viewed in the X-axis direction, even if the joint by welding and the joint by the caulking portion 200 are both canceled, the convex portion 161 and the fitting portion 144 are not circular. One of the joints 144 does not idle with respect to the other. As a result, the outer shaft 140 and the tube 160 can be rotated at the same time even in the worst case.

The fitting portion 144 is provided at one end of the outer shaft 140, the projection 161 is provided on the tube 160, and the projection 161 and the fitting portion 144 are elongated when viewed in the X-axis direction. The ball grooves 142 are provided on each of the pair of long side portions 144a of the fitting portion 144, and the crimped portions 200 are provided on each of the pair of short side portions 144b of the fitting portion 144. there is

According to this, since the crimped portion 200 is provided on each of the pair of short side portions 144b of the fitting portion 144, the two crimped portions 200 can be arranged to face each other. Therefore, since two crimped portions 200 can be formed by compressing the outer shaft 140 so as to sandwich it, it is possible to increase the fastening force.

The long side portions 144a of the fitting portion 144 are thicker than the short side portions 144b. Since the ball grooves 142 are provided on the long side portions 144a, the ball grooves 142 can be easily formed. Moreover, deformation of the ball groove 142 due to caulking can be further suppressed.

A pair of flat portions 146 are formed on the long side portion 144 a of the fitting portion 144 so as to sandwich the ball groove 142 and contact the convex portion 161 .

According to this, since the pair of flat portions 146 of the fitting portion 144 are in contact with the convex portion 161 and are in surface contact, the rotation of one of the outer shaft 140 and the tube 160 is smoothly transmitted to the other. can do.

One end of outer shaft 140 and tube 160 are welded together.

According to this, since the one end of the outer shaft 140 and the tube 160 are welded, the outer shaft 140 and the tube 160 can be firmly joined.

A plurality of crimped portions 200 are provided and arranged evenly in the circumferential direction.

According to this, since the plurality of crimped portions 200 are evenly arranged in the circumferential direction, it is possible to suppress displacement of the axial centers of the outer shaft 140 and the tube 160 due to crimping.

Although the intermediate shaft according to the present invention has been described above based on the above embodiment, the present invention is not limited to the above embodiment.

For example, in the embodiment described above, the tube 160 was exemplified as an example of the connecting member joined to one end of the outer shaft 140 . However, the connecting member is not limited to the tube 160 as long as it is a member joined to one end of the outer shaft 140 . Another example of the connecting member is a yoke that constitutes a universal joint.

In the above embodiment, the steering shaft 12 is connected to the first universal joint 17 on the other end side of the intermediate shaft 100, and the pinion shaft 13 is connected to the second universal joint 18 on the one end side. exemplified. However, the pinion shaft 13 may be connected to the first universal joint 17 of the intermediate shaft 100 and the steering shaft 12 may be connected to the second universal joint 18 .

In the above-described embodiment, the convex portion 161 and the fitting portion 144 are elongated. However, the convex portion 161 and the fitting portion 144 may be non-circular. Since the convex portion 161 and the fitting portion 144 are non-circular, it is possible to prevent one of the convex portion 161 and the fitting portion 144 from spinning with respect to the other. Other shapes of the convex portion 161 and the fitting portion 144 include, for example, a polygonal shape, a substantially circular shape with a part cut out, and the like. Also, the protrusion 161 and the fitting portion 144 may have different shapes as long as the idling can be regulated.

Further, in the above-described embodiment, the intermediate shaft 100 that employs joining by welding and joining by the crimped portion 200 has been exemplified. However, it is also possible to adopt joining methods other than welding. Joining methods other than welding include press fitting and adhesion.

In the above-described embodiment, the case where two crimped portions 200 are provided is exemplified. However, it suffices that the number of crimped portions is one or more. Further, when a plurality of crimped portions 200 are provided, it is desirable that they are arranged evenly in the circumferential direction, but they may be arranged unevenly in the circumferential direction. In this case, if the resultant force of the fastening force applied to each of the crimped portions 200 is aligned with the axial center of the outer shaft 140 when forming the plurality of crimped portions 200, the outer shaft 140 and the tube 160 can be separated from each other. It is possible to suppress displacement of the axis due to caulking.

Further, in the above-described embodiment, the case where the projecting portion 161 is provided at one end portion of the tube 160 and the fitting portion 144 is provided at the outer shaft 140 is exemplified. However, one end of the outer shaft may be provided with a convex portion and the tube may be provided with a fitting portion. In this case, since the tube is arranged outside the outer shaft, a crimped portion is formed on the tube.

In addition, forms obtained by applying various modifications to the embodiments that a person skilled in the art can think of, or realized by arbitrarily combining the constituent elements and functions of the embodiments and modifications without departing from the scope of the present invention. Also included in the present invention.

The present invention is applicable to intermediate shafts having ball grooves.

10 Steering Device 11 Steering Wheel 12 Steering Shaft 13 Pinion Shaft 14 Rack Shaft 15 Steering Wheel 16 Steering Mechanism 17 First Universal Joint 18 Second Universal Joint 100 Intermediate Shaft 110 Intermediate Shaft 140 Outer shaft (sleeve) 141, 148, 162 Through hole 142, 151 Ball groove 143 Guide part 144 Fitting part 144a, 161a Long side part 144b, 161b Short side part 146 Flat part 147 Lid Body 149 Wall Part 150 Inner Shaft 160 Tube (Connecting Member) 161 Protruding Part 163 Pedestal Part 164 Stepped Part 165 Recessed Part 171, 181 First Yoke 172, 182 Second Yoke 173, 183 Cross Axle, 200 caulking part, B ball

Claims (6)

a sleeve having ball grooves along the axial direction on its inner peripheral surface;
a connecting member joined to one end of the sleeve;
a crimped portion formed by crimping at least one of one end of the sleeve and the connecting member;
The crimped portion is arranged at different positions in the circumferential direction with respect to the ball groove. One of the one end of the sleeve and the connecting member is provided with a convex portion protruding in the axial direction, and the other of the one end of the sleeve and the connecting member is fitted with the convex portion. A fitting part is provided,
The intermediate shaft according to claim 1, wherein the convex portion and the fitting portion are non-circular when viewed in the axial direction. The fitting portion is provided at one end of the sleeve,
The convex portion is provided on the connecting member,
The convex portion and the fitting portion are formed to be long when viewed in the axial direction,
The ball groove is provided on each of a pair of long side portions of the fitting portion,
3. The intermediate shaft according to claim 2, wherein the crimped portion is provided on each of the pair of short side portions of the fitting portion. 4. The intermediate shaft according to claim 3, wherein a pair of plane portions are formed on the long side portions of the fitting portion so as to sandwich the ball groove and abut on the convex portion. The intermediate shaft according to any one of claims 1 to 4, wherein one end of the sleeve and the connecting member are welded together. The intermediate shaft according to any one of claims 1 to 5, wherein a plurality of said crimped portions are provided and arranged evenly in said circumferential direction.

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