JP2008189223A - Steering device shaft and manufacturing method thereof - Google Patents

Abstract

A shaft for a steering device is provided that can increase buckling strength and vibration rigidity on the side where a steering wheel is fixed, and can be manufactured at low cost without requiring thickness control.
A solid core material 37 made of a metal material is embedded in a hollow portion 30a1 on one end side 30a of a steering device shaft 30. The core member 37 has a large outer diameter in the cavity portion 30a1 where the bearing holding surface 34 on the one end side 30a is formed, and is gradually reduced in diameter to the cavity portion 30a1 where the male spline 33 is formed. The cavity 30a1 at the position where the male screw 32 is formed is embedded with the smallest outer diameter. One end side 30a of the shaft for the steering device has a solid structure.
[Selection] Figure 3

Description

  The present invention relates to a steering device shaft for fixing a steering wheel to a rear end, which is a component of an automobile steering device, and a method for manufacturing the same.

  A steering shaft of an automobile steering device is disposed inside a steering column supported by a vehicle body side member and is rotatably supported. A steering wheel is fixed to the rear end of the steering shaft, and the steering shaft is rotated by steering the steering wheel. This rotational force is transmitted to the steering gear via the universal joint and the transmission shaft, and the steering gear rotates. By converting the motion into a linear motion in the vehicle width direction, the steered wheels are steered through tie rods.

  Here, recent steering shafts employ a collapsible structure that reduces the overall length when an impact force acts in order to protect the driver during a secondary vehicle collision. In other words, the steering shaft has a hollow first shaft with a steering wheel fixed to the rear end of the vehicle, and a torque that allows the first shaft to move relative to the vehicle front side in the axial direction and restricts movement in the rotational direction. When the impact force is applied to the steering wheel, the torque transmission portions of the first shaft and the second shaft move relative to each other in the axial direction to shorten the overall length.

As a structure of the hollow first shaft described above, for example, a hollow steering shaft described in Patent Document 1 is known. This steering shaft is made of a hollow tube having a circular cross section, and the diameter of one end side of this material is reduced. On the one end side of the reduced diameter, a tapered portion, a spline portion, a male screw portion, etc. A wheel mounting portion is formed. Further, either one of the inner and outer peripheral surfaces on the other end side of the material is subjected to serration processing that engages the second shaft slidably in the axial direction.
Japanese Patent Laid-Open No. 11-247835

  By the way, since the one end side which fixes the steering wheel of the steering shaft of patent document 1 is a hollow shape, if thickness control is not performed when performing diameter reduction processing on one end side, a tapered portion is formed on one end side which has become a thin shape. When a wheel mounting portion such as a spline portion or a male screw portion is formed, the fixing portion may buckle and deform when the steering wheel is fixed, and the steering shaft may sink.

Further, since the one end side of the hollow shape of the steering shaft has low rigidity against vibration, secondary processing for increasing vibration rigidity is required.
Therefore, the present invention has been made paying attention to the above-mentioned unsolved problems of the conventional example, and increases the buckling strength and vibration rigidity on the side where the steering wheel is fixed, and does not require wall thickness management and is manufactured at low cost. An object of the present invention is to provide a steering device shaft and a method of manufacturing the same.

  In order to achieve the above-mentioned object, the invention according to claim 1 is the wheel mounting for fixing the steering wheel to the one end side of the hollow tube-shaped one end side in the longitudinal direction and reducing the diameter. Forming a section, enabling relative movement in the axial direction with respect to other members fitted on either one of the inner and outer peripheral surfaces on the other end side in the longitudinal direction, and restricting movement in the rotational direction In the steering device shaft provided with the torque transmitting portion, the one end side has a solid structure by embedding a core material in the hollow portion on the one end side that has been reduced in diameter.

According to a second aspect of the present invention, in the steering device shaft according to the first aspect, the core material is a synthetic resin member.
According to a third aspect of the present invention, in the steering device shaft according to the first or second aspect, a movement restricting portion for restricting the axial movement of the core member is provided on the inner peripheral surface on the one end side.
On the other hand, the invention of claim 4 performs a diameter reducing process on one end side of the shaft material having a hollow tube shape, and forms a wheel mounting portion for fixing the steering wheel on the one end side reduced in diameter. A torque transmitting portion that enables relative movement in the axial direction with respect to other members fitted to either one of the inner and outer peripheral surfaces on the other end side of the shaft material and restricts movement in the rotational direction. In the method of manufacturing a shaft for a steering device by providing a core material, a core material is inserted into the hollow portion on the one end side before reducing the diameter on the one end side, and simultaneously with the diameter reduction processing on the one end side, A method of manufacturing a shaft for a steering device, wherein the material is plastically deformed so that the one end side has a solid structure.

According to a fifth aspect of the present invention, in the method of manufacturing a shaft for a steering device according to the fourth aspect, a protrusion projecting in a radial direction is formed on an inner peripheral surface on one end side of the shaft material, and the one end Simultaneously with the diameter reduction processing on the side, the protrusion was engaged with the core member, and the protrusion was used as a movement restricting portion for restricting the axial movement of the core member.
Furthermore, the invention described in claim 6 is to reduce the diameter of one end of the shaft material having a hollow tube shape, and to form a wheel mounting portion for fixing the steering wheel to the one end of the reduced diameter. Torque transmission that enables relative movement in the axial direction with respect to other members fitted on one of the inner and outer peripheral surfaces on the other end side of the shaft material and restricts movement in the rotational direction In the method for manufacturing the shaft for a steering device by providing a portion, after reducing the diameter of the one end side, the hollow portion of the portion where the buckling load on the one end side is increased from the opening on the other end side is arranged in the axial direction. A method of manufacturing a shaft for a steering device, wherein a core material is embedded while restraining movement.

  According to the shaft for a steering device and the manufacturing method thereof according to the present invention, since the one end side has a solid structure by embedding a core material in the hollow portion on one end side for fixing the steering wheel, the buckling strength on one end side, The shaft for a steering device can be manufactured at low cost by increasing the vibration rigidity and eliminating the need for wall thickness management.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
FIG. 1 is an overall configuration diagram showing a vehicle assembled with a steering device according to the present invention, and FIG. 2 is a side view of the steering device.
In FIG. 1, a steering device 10 is disposed to be inclined at a predetermined angle so as to rise rearward of the vehicle with respect to the horizontal direction of the vehicle, and includes a steering column 12 that rotatably supports a steering shaft 11. A steering wheel 13 is mounted at the rear end of the steering shaft 11, and an intermediate shaft 15 is connected to the front end of the steering shaft 11 via a universal joint 14. A steering gear 17 composed of a rack and pinion mechanism or the like is connected to the intermediate shaft 15 through a universal joint 16 at the front end thereof. The output shaft of the steering gear 17 is connected to the steered wheel 19 through a tie rod 18.

When the driver steers the steering wheel 13, the rotational force is transmitted to the steering gear 17 via the steering shaft 11, the universal joint 14, the intermediate shaft 15, and the universal joint 16, and the rack and pinion mechanism rotates the vehicle. The steered wheel 19 is steered through the tie rod 18 after being converted into a linear motion in the width direction.
2, the steering shaft 11 is engaged with an outer shaft 30 to which a steering wheel 13 (not shown in FIG. 2) is fixed, and is splined to the outer shaft 30 so as to be slidable in the column axis P1 direction. It is comprised with the inner shaft 31 made.

  The steering column 12 includes an outer column 12a and an inner column 12b that is slidably held in the direction of the column axis P1 by the outer column 12a. The steering column 12 is disposed on the inner peripheral surface of the vehicle front side end portion of the inner column 12b. The steering shaft 11 is rotatably supported by the rolling bearing 12c and the rolling bearing 12d disposed on the inner peripheral surface of the vehicle front side end portion of the outer column 12a.

  A U-shaped column side bracket 20 is fixed to the vehicle front side (universal joint 14 side) of the inner column 12 b, and an insertion hole 21 is formed in the column side bracket 20. Also, an insertion hole (not shown) is formed in the vehicle body bracket 23 on the vehicle front side fixed to the vehicle body side member 22, and the axis of the insertion hole and the insertion hole 21 of the column side bracket 20 are aligned to form a tilt pivot. By inserting the shaft 24, the vehicle front side of the inner column 12b is pivotally supported by the vehicle body side member 22 so as to be tiltable.

  In addition, a pair of clamp portions (only one clamp portion 25a is shown in FIG. 2) are formed integrally on the vehicle front side of the outer column 12a and are spaced apart in the vehicle width direction to hold the outer periphery of the inner column 12b. The vehicle rear side body bracket 26 fixed to the vehicle body side member 22 sandwiches the pair of clamp portions 25a from the vehicle width direction, and the pair of clamp portions 25a are adjacent to the vehicle rear side body bracket 26. A clamp device 27 is provided that clamps the inner column 12b so that the inner column 12b cannot be relatively moved in the direction of the column axis P1.

The vehicle rear side body bracket 26 includes a flange 26a and a pair of side plates (not shown) extending in the vertical direction from the flange 26a and spaced apart in the vehicle width direction. A detachment capsule 29 is fitted to the flange 26a at the end on the vehicle rear side, and the detachment capsule 29 is fixed to the vehicle body side member 22 via a fixing bolt.
The clamp device 27 includes a side plate (not shown) that is spaced apart in the vehicle width direction of the vehicle body bracket 26 on the vehicle rear side, and a tightening rod 27a that is inserted into the telescopic elongated hole 25a2 of the pair of clamp portions 25a. A fixed cam (not shown), a movable cam (not shown), an adjustment nut (not shown), and an operation lever 27e fixed to the movable cam are provided on the screw side of the tightening rod 27a.

(First embodiment: structure of outer shaft)
3 to 5 show the structure of the outer shaft 30 of the first embodiment constituting the steering shaft 11. 3 is a cross section along the axial direction of the outer shaft 30 of the first embodiment, FIG. 4 is a transverse cross section showing the structure of the other end side of the outer shaft 30, and FIG. 5 is different from FIG. 3 is a transverse cross section showing a structure on the other end side of the outer shaft 30.

The outer shaft 30 of the present embodiment is a metal hollow tube-shaped member made of iron, aluminum alloy, or the like, and the one end side 30a has a shape that is gradually reduced in diameter toward the end, The other end 30b is formed with the same outer diameter.
One end side 30a of the outer shaft 30 is formed with a male screw 32 on the outer periphery on the end portion side with the most reduced diameter, and a male spline on the outer periphery at a position where the diameter of the male screw 32 is increased adjacent to the other end side 30b. 33 is formed, and a bearing holding surface 34 on which the inner ring of the rolling bearing 12d described above is fitted is formed on the outer periphery of the male spline 33 at a position close to the other end 30b.

Although not shown, a female spline formed in the shaft hole of the steering wheel 13 is engaged with the male spline 33 on the one end side 30a of the outer shaft 30, and a nut is attached to the male screw 32 protruding from the shaft hole of the steering wheel 13. By tightening, the steering wheel 13 is fixed to the end of the one end side 30a.
On the other hand, as shown in FIGS. 3 and 4, spline groove portions 35 a to 35 d extending in the axial direction are formed on the inner peripheral surface of the other end side 30 b of the outer shaft 30 at predetermined intervals in the circumferential direction. Yes. These spline groove portions 35 a to 35 d engage with spline shaft portions 36 a to 36 e formed on the outer periphery of the inner shaft 31. Here, the spline groove portion 35c of the outer shaft 30 is set to have a groove width with which the two spline shaft portions 36c and 36d of the inner shaft 31 are engaged, whereby the spline groove portion 35c and the spline shaft portions 36c and 36d An air vent space S communicating with the outside air is defined between them. As shown in FIG. 5, the groove bottoms of the spline groove portions 35 a to 35 e of the outer shaft 30 and the shaft top portions of the spline shaft portions 36 a to 36 e of the inner shaft 31 are separated from each other. An air vent space S communicating with the outside air may be defined therebetween.

  Here, a solid core member 37 made of a metal material such as iron or an aluminum alloy is embedded in the hollow portion 30a1 on the one end side 30a. The core member 37 has a large outer diameter in the cavity portion 30a1 where the bearing holding surface 34 on the one end side 30a is formed, and is gradually reduced in diameter to the cavity portion 30a1 where the male spline 33 is formed. The cavity 30a1 at the position where the male screw 32 is formed is embedded with the smallest outer diameter. Thereby, the one end side 30a of the outer shaft 30 has a solid structure.

And, on one end surface located on the other end side 30b of the core member 37, an annular retaining portion 38 formed to protrude radially inward from the inner peripheral surface of the one end side 30a abuts, The core member 37 in which the retaining portion 38 is in contact with one end face is prevented from coming out to the other end side 30b (left side in FIG. 3).
Next, operations and effects of the steering device 10 using the outer shaft 30 of the present embodiment will be described.

  In order to perform telescopic adjustment of the steering device 10, as shown in FIG. 2, the operation lever 27e of the clamp device 27 is rotated in a direction in which the pair of clamp portions 25a are separated from each other. Thereby, the tightening of the pair of side plates of the vehicle rear side body bracket 26 is released, and the clamp of the inner column 12b by the pair of clamp portions 25a is released, so that the tightening rod 27a is moved in the long axis direction of the telescopic long hole 25a2. While sliding, the outer column 12a is moved in the direction of the column axis P1, and the steering wheel 13 is moved to a predetermined position in the vehicle longitudinal direction.

  Then, the operation lever 27e of the clamp device 27 is rotated in a direction in which the pair of clamp portions 25a are close to each other. As a result, the pair of side plates of the vehicle rear side body bracket 26 are tightened in the direction of approaching each other, the circle defined by the inner peripheral surfaces of the pair of clamp portions 25a is reduced in diameter, and the outer peripheral surface of the inner column 12b is substantially reduced. Since they are in contact with the entire region, the pair of clamp portions 25a are clamped on the inner column 12b while being unable to move in the direction of the column axis P1, and the telescopic adjustment is completed.

On the other hand, when an impact load (reference numeral F in FIG. 2) is applied from the driver to the steering wheel 13 at the time of the secondary collision of the vehicle, the impact load is applied from the steering wheel 13 to the steering column 12 via the steering shaft 11. Join.
At this time, in the steering shaft 11 to which the impact load F is input from the steering wheel 13, the outer shaft 30 moves to the front side of the vehicle while the spline groove portions 35a to 35d slide on the spline shaft portions 36a to 36e of the inner shaft 31. The driver is protected by reducing the overall length. When the entire length of the steering shaft 11 is reduced, the air vent space S (see FIG. 4) defined between the spline groove portion 35c of the outer shaft 30 and the spline shaft portions 36c and 36d of the inner shaft 31, or the outer shaft 30 From the air vent space S (see FIG. 5) defined between the groove bottoms of the spline groove portions 35 a to 35 e and the shaft top portions of the spline shaft portions 36 a to 36 e of the inner shaft 31, the air is accumulated between the outer shaft 30 and the inner shaft 31. Since the air being discharged is immediately discharged to the outside air, the shrinking operation of the steering shaft 11 is performed smoothly.

When an impact load is applied to the steering column 12, an impact force toward the vehicle front side is input to the vehicle rear side vehicle body bracket 26 that supports the outer column 12 a on the vehicle body side member 22.
At this time, the vehicle rear side of the flange 26a of the vehicle rear side body bracket 26 is fixed to the vehicle body side member 22 via the detachment capsule 29, and when the impact force to the vehicle front side is input to the flange 26a, the detachment occurs. The impact force is absorbed while the flange 26a comes out of the capsule 29.

  And even if the outer shaft 30 one end side 30a of this embodiment becomes thin and thick when the diameter is reduced in stages, the core material 37 made of a metal material is embedded in the cavity 30a1 and buckled. Since it has a solid structure with high strength, the male spline 33 and the male screw 32 do not buckle when the steering wheel 13 is fixed to the end of the one end side 30a, and the outer shaft 30 is not likely to sink.

Further, if the core member 37 is embedded in the hollow portion 30a1 on the one end side 30a, the vibration rigidity becomes high, so that the vibration of the engine or the like is hardly transmitted to the steering wheel 13.
Further, the retaining member 38 protruding radially inward from the inner peripheral surface of the one end side 30a comes into contact with one end surface located on the other end side 30b of the core member 37, and the core member 37 comes out of the cavity portion 30a1. Therefore, the buckling strength and vibration rigidity of the one end side 30a of the outer shaft 30 are maintained for a long period of time.

  Therefore, the outer shaft 30 of the present embodiment can increase the buckling strength of the one end side 30a to securely fix the steering wheel 13, and can also increase the vibration rigidity of the one end side 30a to generate vibration transmitted to the steering wheel 13. This can suppress the driver's uncomfortable feeling caused by the vibration of the steering wheel 13.

(Second Embodiment: Structure of Outer Shaft)
Next, FIG. 6 shows the structure of the outer shaft 30 of the second embodiment. In addition, the same code | symbol is attached | subjected to the same component as the structure shown in FIG. 3, and the description is abbreviate | omitted.
In the outer shaft 30 of the present embodiment, a solid core 39 made of synthetic resin is embedded in a cavity 30a1 on one end side 30a. The core 39 has a large outer diameter in the cavity 30a1 at the position where the bearing holding surface 34 on the one end side 30a is formed, and is gradually reduced in diameter to the cavity 30a1 at the position where the male spline 33 is formed. The cavity 30a1 at the position where the male screw 32 is formed is embedded with the smallest outer diameter. Thereby, the one end side 30a of the outer shaft 30 has a solid structure.

An annular retaining portion 38 abuts on one end face located on the other end side 30b of the core member 37, and the core member 39 is prevented from coming off to the other end side 30b (left side in FIG. 6).
According to the present embodiment, as in the first embodiment, the buckling strength of the one end side 30a can be increased to securely fix the steering wheel 13, and the vibration rigidity of the one end side 30a can be increased to be transmitted to the steering wheel 13. The vibration can be suppressed, the driver's uncomfortable feeling can be reduced, and the use of the synthetic resin core material 39 can reduce the weight of the outer shaft 30.

(Structure of the outer shaft of the third embodiment)
Next, FIG.7 and FIG.8 is a figure which shows the one end side 30a of the outer shaft 30 of 3rd Embodiment.
A solid core material 37 made of a metal material such as iron or aluminum alloy is embedded in one end side 30a of the outer shaft 30 shown in FIG.
An annular retaining portion 40 protruding radially inward is formed on the inner peripheral surface of the position where the bearing holding surface 34 on the one end side 30a is formed, and is in close contact with the annular retaining portion 40. In this state, an annular recess 37 a is formed in a part of the large outer diameter portion of the core member 37.

  As described above, a concave portion 37a is formed in a part of the large outer diameter portion of the core member 37, and the retaining portion 40 protruding radially inward from the inner peripheral surface of the one end side 30a is in close contact with the concave portion 37a. Therefore, the core member 37 can be reliably prevented from coming out of the hollow portion 30a1, and the buckling strength and vibration rigidity of the one end side 30a of the outer shaft 30 can be maintained over a long period of time.

A solid core member 37 made of a metal material such as iron or aluminum alloy is also embedded in one end side 30a of the outer shaft 30 shown in FIG.
An annular retaining portion 41 that is recessed radially outward is formed on the inner peripheral surface of the position where the male screw 32 on the one end side 30a is formed, and the core material is in close contact with the retaining portion 41. An annular convex portion 37 b is formed on a part of the smallest outer diameter portion 37.

  Thus, the convex part 37b is formed in a part of small outer diameter part of the core material 37, and this convex part 37b was dented in the radial direction outward to the inner peripheral surface with the smallest inner diameter of the one end side 30a. Since the retaining portion 41 is in close contact, the core member 37 can be reliably prevented from coming out of the hollow portion 30a1, and the buckling strength and vibration rigidity of the one end side 30a of the outer shaft 30 can be maintained over a long period of time. can do.

(Fourth embodiment: structure of outer shaft)
Next, FIG. 9 shows the structure of the outer shaft 30 of the fourth embodiment.
In this embodiment, a female screw 42 is formed on the inner peripheral surface between the position where the male spline 33 on the one end side 30a is formed and the position where the bearing holding surface 34 is formed.
Further, a screw core member 43 having a male screw formed on the outer periphery made of a metal material such as iron or aluminum alloy is inserted into the hollow portion 30a1 on the one end side 30a from the opening on the other end side 30b and screwed into the female screw 42. It is.

Thereby, the site | part between the position which forms the male spline 33 of the one end side 30a of the outer shaft 30 and the position which forms the bearing holding surface 34 is made into the solid structure.
According to this embodiment, when the steering wheel 13 is fixed to the end portion of the one end side 30a of the outer shaft 30, the position close to the other end side 30b side with respect to the position where the male spline 33 on the one end side 30a is formed. However, since the screw core member 43 is screwed into the position where the large buckling load is applied to form a solid structure with high buckling strength, the buckling strength of the one end side 30a of the outer shaft 30 is weak. The site can be raised locally.

Further, the outer shaft 30 can be reduced in weight as compared with a structure in which a core material made of a metal material such as iron or aluminum alloy is embedded in the entire cavity 30a1 on the one end side 30a.
Further, since the screw core material 43 is screwed into the female screw 32 formed on the inner peripheral surface of the one end side 30a, the screw core material 43 can be reliably prevented from coming off.
In addition, although not shown in figure, it is based on the diameter of the site | part of the internal peripheral surface in the site | part of the internal peripheral surface between the position which forms the male spline 33 of the one end side 30a, and the position which forms the bearing holding surface 34. When a large-diameter cylindrical member is pressed and embedded, a portion where the buckling strength of the one end side 30a of the outer shaft 30 is weak can be locally increased, as in the fourth embodiment described above. The outer shaft 30 can be reduced in weight.

  In the present embodiment, the screw core material 43 made of a metal material such as iron or aluminum alloy is used. However, if the screw core material made of a rigid resin material is used, the outer shaft 30 can be further reduced in weight. .

(Fifth Embodiment: Outer Shaft Manufacturing Method)
Next, FIG. 10 is a diagram showing a method for manufacturing the outer shaft 30 of the first embodiment shown in FIG. In addition, the same code | symbol is attached | subjected to the same component as the structure shown in FIG. 3, and description is abbreviate | omitted.
This embodiment uses a metal shaft material 45 made of hollow cylindrical tube-shaped iron or aluminum alloy having the same outer diameter in the longitudinal direction. In addition, let one side of the longitudinal direction of this shaft raw material 45 be the one end side 30a, and let it be the other end side 30b of a longitudinal direction.
First, as shown in FIG. 10 (a), the first process is a spline extending in the axial direction on the inner peripheral surface after round drawing of the inner diameter and outer diameter of the other end side 30b of the shaft material 45 is performed. The groove part 35a is formed. Further, an annular protrusion 38a for forming the retaining portion 38 is formed on the inner peripheral surface at a position close to the center in the longitudinal direction of the one end side 30a.

Next, as shown in FIG. 10B, a metal core 37 made of iron or aluminum alloy is inserted into the cavity 30a1 through the opening on one end side 30a, and the end abuts against the protrusion 38a. Let
In the next step, as shown in FIG. 10 (c), by pressing the outer periphery of the one end side 30a or performing a rotary swaging process, stepwise toward the end of the one end side 30a. A reduced diameter outer periphery is formed. At this time, the protrusion 38a formed on the inner periphery of the one end side 30a bulges inward in the radial direction, and the core member 37 inserted into the cavity 30a1 is gradually stepped toward the end of the one end side 30a. It plastically deforms along the shape of the reduced inner peripheral surface. The protrusion 38a bulging inward in the radial direction serves as a retaining portion 38 that prevents the core member 37 from slipping out to the other end side 30b.

In the next step, cutting is performed so that the longitudinal dimension of the shaft material 45 becomes a prescribed dimension, and chamfering of the end portion is performed.
In the next step, as shown in FIG. 10 (d), the male screw 32 and the male spline 33 are formed on the outer periphery which is gradually reduced in diameter toward the end of the one end side 30a. And the outer shaft 30 is manufactured by performing the washing | cleaning operation | work of the shaft raw material 45 whole.

  According to the manufacturing method of the outer shaft 30 of the present embodiment, the core material 37 is plasticized by inserting the core material 37 into the hollow portion 30a1 of the one end side 30a of the shaft material 45 and reducing the diameter of the one end side 30a. The one end side 30a of the solid structure is formed only by deforming, and the outer shaft 30 having a stable quality in which the buckling strength of the one end side 30a is increased without performing thickness control can be manufactured. Can be manufactured at low cost.

Further, by forming the protrusion 38a for the retaining portion 38 on the inner peripheral surface of the shaft material 45, the retaining portion 38 for the core material 37 can be easily formed simultaneously with the diameter reduction processing of the one end side 30a. be able to.
In the present embodiment, the metal core material 37 made of iron, aluminum alloy or the like is used. However, as shown in FIG. When 30 is manufactured, it is possible to manufacture the outer shaft 30 that is reduced in weight.

  In the present embodiment, the retaining portion 38 is in contact with the end surface of the core member 37. However, in order to form the retaining portions 40 and 41 at the positions shown in FIGS. Protrusions for retaining portions 40 and 41 may be formed on the inner peripheral surface.

(Sixth embodiment: outer shaft manufacturing method)
Next, FIG. 11 is a figure which shows the manufacturing method of the outer shaft 30 of 4th Embodiment shown in FIG.
In the first step of this embodiment, as shown in FIG. 11A, the inner diameter and the outer diameter of the other end side 30b of the shaft material 45 are round drawn and then axially extended on the inner peripheral surface. The spline groove portion 35a to be formed is formed.
In the next step, as shown in FIG. 11 (b), by pressing the outer periphery of the one end side 30a or performing a rotary swaging process, stepwise toward the end of the one end side 30a. A reduced diameter outer periphery is formed.

In the next step, as shown in FIG. 11 (c), a female thread 42 is formed at the central portion in the length direction of the inner peripheral surface of the one end side 30a, and the screw core material 43 inserted from the opening of the other end side 30b. Is screwed into the female screw 42.
In the next step, cutting is performed so that the longitudinal dimension of the shaft material 45 becomes a prescribed dimension, and chamfering of the end portion is performed.

In the next step, as shown in FIG. 11 (d), the male screw 32 and the male spline 33 are formed on the outer periphery which is gradually reduced in diameter toward the end of the one end side 30a. And the outer shaft 30 is manufactured by performing the washing | cleaning operation | work of the shaft raw material 45 whole.
According to the manufacturing method of the outer shaft 30 of the present embodiment, after the diameter reduction processing of the one end side 30a is performed, the female screw 42 is formed in the portion where the buckling strength is increased, and the screw core member 43 is screwed into the female screw 42. Since the portion requiring the buckling strength of the one end side 30a can be made into a solid structure without performing wall thickness management, the outer shaft 30 with stable quality can be manufactured while achieving weight reduction.

  In this embodiment, the screw core material 43 made of a metal material such as iron or aluminum alloy is used. However, a screw core material made of a rigid resin material may be used.

1 is an overall configuration diagram showing a vehicle assembled with a steering device according to the present invention. It is a figure which shows the side view of a steering device. It is a cross section along the axial direction of the shaft for steering devices of a 1st embodiment concerning the present invention. It is a cross section which shows the structure of the other end side of the shaft for steering devices which concerns on this invention. FIG. 5 is a transverse cross section showing a structure on the other end side of the steering device shaft having a structure different from that in FIG. 4. It is a cross section along the axial direction of the shaft for steering devices of a 2nd embodiment concerning the present invention. It is a principal part cross section along the axial direction of the shaft for steering devices of 3rd Embodiment which concerns on this invention. FIG. 8 is a cross-sectional view of an essential part along the axial direction of a steering device shaft having a structure different from that of FIG. 7. It is a cross section along the axial direction of the shaft for steering devices of a 4th embodiment concerning the present invention. It is a figure which shows the manufacturing method of the shaft for steering devices of 5th Embodiment which concerns on this invention. It is a figure which shows the manufacturing method of the shaft for steering devices of 6th Embodiment which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Steering device, 11 ... Steering shaft, 12 ... Steering column, 12a ... Outer column, 12b ... Inner column, 12c ... Rolling bearing, 12d ... Rolling bearing, 13 ... Steering wheel, 14 ... Universal joint, 15 ... Intermediate shaft, DESCRIPTION OF SYMBOLS 16 ... Universal joint, 17 ... Steering gear, 18 ... Tie rod, 19 ... Steering wheel, 20 ... Column side bracket, 21 ... Insertion hole, 22 ... Vehicle body side member, 23 ... Vehicle front side vehicle body bracket, 24 ... Tilt pivot shaft, 25a ... Clamping part, 25a2 ... Telescopic slot, 26 ... Vehicle rear side body bracket, 26a ... Flange, 27 ... Clamping device, 27a ... Rod, 27e ... Operation lever, 29 ... Release capsule, 30 ... Outer shaft (steering) Device shaft), 0a ... one end side of the outer shaft, 30a1 ... hollow portion, 30b ... other end side of the outer shaft, 31 ... inner shaft (other member to be fitted), 33 ... male spline, 34 ... bearing holding surface, 35a to 35d ... Spline groove part (torque transmission part), 36a to 36d ... spline shaft part, 37 ... core material, 37a ... concave part, 37b ... convex part, 38 ... retaining part (movement restraining part), 38a ... projection, 39 ... core material, 40, 41 ... retaining portion (movement restraining portion), 43 ... screw core material (core material), 45 ... shaft material, F ... impact load, P1 ... column shaft, S ... air venting space

Claims (6)

The hollow tube-shaped one end side in the longitudinal direction is subjected to diameter reduction processing, and a wheel mounting portion for fixing the steering wheel is formed on the one end side reduced in diameter, both inner and outer peripheral surfaces on the other end side in the longitudinal direction In any one of the peripheral surfaces of the steering device shaft provided with a torque transmission portion that allows relative movement in the axial direction with respect to the other member to be fitted and restricts movement in the rotational direction.
A shaft for a steering device, characterized in that a core material is embedded in the hollow portion of the one end side that has been reduced in diameter so that the one end side has a solid structure.   The shaft for a steering apparatus according to claim 1, wherein the core material is a synthetic resin member.   The steering device shaft according to claim 1, wherein a movement restraining portion for restraining the axial movement of the core member is provided on the inner peripheral surface on the one end side. One end side of the shaft material having a hollow tube shape is subjected to diameter reduction processing, and a wheel mounting portion for fixing the steering wheel is formed on one end side of the diameter reduction, and the inner and outer sides of the other end side of the shaft material are formed. A shaft for a steering device is manufactured by providing a torque transmitting portion that allows relative movement in the axial direction with respect to other members to be fitted and restricts movement in the rotational direction on one of the peripheral surfaces. In the way to
Before reducing the diameter of the one end side, a core material is inserted into the cavity on the one end side, and simultaneously with the diameter reducing process on the one end side, the core material is plastically deformed so that the one end side has a solid structure. A method for producing a shaft for a steering device.   A protrusion projecting in the radial direction is formed on the inner peripheral surface on one end side of the shaft material, and simultaneously with the diameter reduction processing on the one end side, the protrusion is engaged with the core member, and the protrusion is connected to the core. 5. The method for manufacturing a shaft for a steering apparatus according to claim 4, wherein the movement restricting portion restricts the movement of the material in the axial direction. One end side of the shaft material having a hollow tube shape is subjected to diameter reduction processing, and a wheel mounting portion for fixing the steering wheel is formed on one end side of the diameter reduction, and the inner and outer sides of the other end side of the shaft material are formed. A shaft for a steering device is manufactured by providing a torque transmitting portion that allows relative movement in the axial direction with respect to other members to be fitted and restricts movement in the rotational direction on one of the peripheral surfaces. In the way to
After reducing the diameter of the one end side, a core material is embedded by constraining the movement in the axial direction from the opening on the other end side to the hollow portion of the portion that increases the buckling load on the one end side. A method of manufacturing a shaft for a steering device.

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