JP2014051182A - Steering device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for reducing cost while securing rigidity of a steering column.SOLUTION: Stopper parts 24a, 24a are formed by forming cuts in a circumferential direction at a plurality of circumferential portions of a rear end part of a steering column 6b, and bending axially adjacent parts to the cuts. At the same time, fitting parts 25a, 25a are formed by pressing a plurality of circumferential portions of an outer circumferential surface of the steering column 6b inward in a radial direction. Placement of these respective fitting parts 25a, 25a are biased vertically in attached states. An outer ring 20 of a ball bearing 19 is internally fitted and fixed to inner circumference surfaces of the respective fitting parts 25a, and at the same time, a caulking part 26 is formed by plastically deforming a rear end edge of the steering column 6b inward in the radial direction.

Description

  The present invention relates to an improvement in a steering device and a manufacturing method thereof for imparting a snake angle to a steering wheel of an automobile.

  The automobile steering apparatus is configured as shown in FIG. 10, and transmits the rotation of the steering wheel 1 to the input shaft 3 of the steering gear unit 2, and a pair of left and right tie rods 4 in accordance with the rotation of the input shaft 3. 4 is pushed and pulled to give a steering angle to the front wheels. The steering wheel 1 is supported and fixed at the rear end portion of the steering shaft 5, and the steering shaft 5 is rotatably supported by the steering column 6 with the cylindrical steering column 6 inserted in the axial direction. Has been. Further, the front end portion of the steering shaft 5 is connected to the rear end portion of the intermediate shaft 8 via a universal joint 7, and the front end portion of the intermediate shaft 8 is connected to the input shaft 3 via another universal joint 9. Connected to.

  With such a steering device, a tilt mechanism for adjusting the vertical position of the steering wheel 1 and a telescopic mechanism for adjusting the front-rear position according to the physique and driving posture of the driver have been widely known. ing. In order to constitute the tilt mechanism, the steering column 6 is supported with respect to the vehicle body 10 so as to be capable of swinging around the pivot 11 installed in the width direction. Further, a displacement bracket fixed to a portion near the rear end of the steering column 6 is supported so as to be able to be displaced in the vertical direction and the front-rear direction with respect to the support bracket 12 supported on the vehicle body 10. Among these, in order to constitute a telescopic mechanism that enables displacement in the front-rear direction, the steering column 6 has a structure in which an outer column 13 and an inner column 14 are telescopically combined to expand and contract, and the steering shaft 5 The outer tube 15 and the inner shaft 16 are combined with each other so as to be able to transmit torque and expand and contract by spline engagement or the like. The illustrated example also incorporates an electric power steering device that reduces the force required to operate the steering wheel 1 using the electric motor 17 as an auxiliary power source.

  The steering column 6 (outer column 13) is often made of an electric sewing tube (original tube) made of an iron-based alloy or the like in order to reduce manufacturing costs. As shown in FIG. 11, such a cylindrical outer column 13 forms a stepped portion 18 by cutting the inner peripheral surface of the rear end portion. Then, a front end surface of an outer ring 20 constituting a bearing capable of supporting a radial load and a thrust load, such as a single row deep groove type ball bearing 19, is abutted against the stepped portion 18, and the ball bearing 19 against the outer column 13. The outer ring 20 is internally fitted and fixed to the rear end portion of the outer column 13 with an interference fit in a state where the axial positioning is achieved. Further, the inner ring 21 constituting the ball bearing 19 is externally fitted and fixed to the intermediate portion in the axial direction of the outer tube 15 constituting the steering shaft 5. With such a structure, the steering shaft 5 is rotatably supported on the steering column 6 via the ball bearings 19.

  12 to 13 illustrate a steering column 6a described in Patent Document 1 and constituting a steering device. This steering column 6a is provided with a plurality of tongue pieces 22 by punching a plurality of circumferential locations in the axial intermediate portion into a U-shape at equal intervals and bending the punched inner portion radially inward. . In addition, among the peripheral portions of the punched opening 23, the center portion of the front end edge and the left and right side edges of the opening 23 is plastically deformed radially inward to be fitted to the stopper portion 24. The portions 25 and 25 are formed. Then, the front end surface of the outer ring 20 of the ball bearing 19 is abutted against the rear end surface of each of the stopper portions 24 to achieve axial positioning, and the outer peripheral surface of the outer ring 20 is connected to the fitting portions 25, 25. It is fitted and fixed to the inner peripheral surface. Further, the front end face (front end face) of each tongue piece 22 is engaged with the rear end face of the outer ring 20, and the outer ring 20 is sandwiched between the tongue pieces 22 and the stopper portions 24 from both sides in the axial direction. This prevents the ball bearing 19 from being displaced in the axial direction.

  In the case of the steering column 6a described in Patent Document 1 as described above, a structure for internally fitting and fixing the ball bearing 19 to the inner peripheral surface of the steering column 6a in a state where the ball bearing 19 is positioned in the axial direction, This can be realized without cutting as in the first example of the conventional structure described above, and an increase in the manufacturing cost of the steering column 6a can be suppressed. However, in the case of the second example of the conventional structure described in Patent Document 1, there is room for improvement from the viewpoint of further reducing the manufacturing cost. That is, in the case of the second example of the conventional structure, first, the tongue portions 22 and the openings 23 are provided by punching the intermediate portion in the axial direction of the steering column 6a. The stopper portions 24 and the fitting portions 25 and 25 are provided by pressing the front edge and the center of the left and right edges toward the inside in the radial direction. Next, the ball bearing 19 is fitted into the inner peripheral surfaces of the fitting portions 25 and 25 while the ball bearing 19 is positioned in the axial direction by the stopper portions 24. Thereafter, each of the tongue pieces 22 is bent radially inward to prevent the ball bearing 19 from being displaced in the axial direction. For this reason, there is a possibility that the manufacturing cost increases due to an increase in the number of processes or the need for a complicated mold. Further, since a relatively large opening 23 is provided at a plurality of locations in the circumferential direction of the steering column 6a so as to penetrate in the radial direction, the rigidity of the steering column 6a is reduced at the portion where the ball bearing 19 is installed. there's a possibility that.

JP-A-11-342853

  In view of the circumstances as described above, the present invention improves the productivity of a steering device that rotatably supports a steering shaft inside a steering column via a bearing while ensuring the rigidity of the steering column. Invented to realize a structure that can be manufactured at low cost and a method for manufacturing the structure.

Among the steering apparatus and the manufacturing method thereof according to the present invention, the steering apparatus according to claim 1 includes a steering column and a steering shaft.
Among these, the steering column has a hollow circular tube shape and is supported by the vehicle body.
The steering shaft has a steering wheel fixed to a rear end portion thereof, and is rotatably supported in the steering column via a bearing.
In particular, in the steering device of the present invention, the center side of the steering column (opening for press-fitting the bearing) with respect to circumferential notches provided at a plurality (at least two or more) in the circumferential direction of the steering column. A plurality of stopper portions are provided by bending a portion adjacent to each of the cuts in the axial direction inwardly in the radial direction. Then, the outer end surface of the outer ring of the bearing is abutted against each of the stopper portions to achieve axial positioning. Further, a plurality of circumferential positions (at least three positions) on the opening side of the steering column with respect to the respective incisions in the axial direction on the outer peripheral surface of the steering column are plastically deformed radially inward, thereby causing a plurality of The fitting part is provided. And the outer ring | wheel of the said bearing is internally fitted and fixed to these each fitting part. Furthermore, these fitting parts are arranged unevenly in the circumferential direction.

When the steering device of the present invention as described above is implemented, preferably, as in the invention described in claim 2, the arrangement of the respective fitting portions is in an attached state (a state in which the steering device is attached to the vehicle body). Bias up and down at
Preferably, as in the invention described in claim 3, the bearing is fitted and fixed to the end of the steering column, and the end of the steering column is plastically deformed radially inward. Thus, the bearing is prevented from coming off.

  Further, in the manufacturing method of the steering device according to claim 4, while making circumferential incisions at a plurality of circumferential positions on the outer peripheral surface of the steering column, with respect to each of these incisions, on the center side of the steering column, The respective stopper portions are provided by bending a portion adjacent to the axial direction inward in the radial direction (performing cutting and bending). At the same time, on the opening side of the steering column with respect to each notch in the axial direction on the outer peripheral surface of the steering column, a plurality of non-uniform portions in the circumferential direction are pressed radially inward to cause plastic deformation. By doing so, a fitting portion in which the inner diameter of the inner peripheral surface is smaller than the inner diameter of the portion adjacent in the circumferential direction is provided.

In the case of carrying out the invention described in claim 4 as described above, preferably, as in the invention described in claim 5, recesses are provided in a plurality of portions that are uneven in the circumferential direction of the outer peripheral surface in the steering column. Insert the core so that the axial position of the front end surface of the core matches the axial position where the end surface of the outer ring of the bearing is located when the bearing is assembled in the steering column. Is regulated and inserted. Further, a pressing punch is disposed at a portion radially outward of the steering column and a phase in the circumferential direction coincides with the concave portion of the core, and blade portions of the shearing tool are disposed at a plurality of circumferential positions. These pressing punches and shearing tools are driven by engaging a driven side inclined surface provided on each outer peripheral surface with a driving side inclined surface of a slide block supported by the pressing plate and displaced together with the pressing plate. As the plate is displaced in the vertical direction, it is displaced in the radial direction. Then, as the pressing plate is displaced downward, the pressing punch and the shearing tool are displaced radially inward, and the outer periphery of the steering column is formed by a convex portion provided on the inner peripheral surface of the pressing punch. Each said fitting part is formed by pressing a surface. At the same time, a notch is formed in the outer peripheral surface of the steering column by the blade portion of the shearing tool, and the blade portion is displaced radially inward along the tip surface of the core, and is adjacent to the notch. Each of the stoppers is formed by bending the portion radially inward.

Preferably, as in the invention described in claim 6, each stopper portion and each fitting portion are formed at an end portion of the steering column, and the bearing is attached to the end portion of the steering column. When pressing and pressing in the axial direction, a concave curved surface or tapered surface with a partially arcuate cross section is provided at the tip of the press-fitting jig and is inclined in the direction of the radial outward as it goes to the tip. The edge of the steering column is plastically deformed inward in the radial direction by an inclined surface portion such as, and a caulking portion is formed. The number of the caulking portions and the phase related to the circumferential direction are not particularly limited. That is, the caulking portion can be provided over the entire circumference of the end portion of the steering column, or can be provided intermittently at a plurality of locations in the circumferential direction of the end portion.
In this case, preferably, as in the invention described in claim 7, the amount of pressing of the outer peripheral surface of the steering column by the convex portion of each pressing punch is gradually reduced toward the edge of the steering column. To do. And the taper-shaped guide part which inclined in the direction which goes to radial direction outward is provided in the part near the edge of each said fitting part toward the opening edge.

According to the present invention configured as described above, the steering device that rotatably supports the steering shaft on the inside of the steering column via the bearing can improve the productivity while ensuring the rigidity of the steering column. Can be obtained at low cost.
That is, in the case of the present invention, the stopper portion for positioning the bearing in the axial direction is provided with a plurality of circumferential incisions in the circumferential direction of the outer peripheral surface of the steering column. It is provided by bending the axially adjacent portion radially inward on the center side of the steering column. Therefore, as in the second example of the conventional structure shown in FIGS. 12 to 13 described above, it is not necessary to provide a relatively large opening 23 in a state where the outer peripheral surface of the steering column 6a penetrates in the radial direction. Reduces the rigidity of the steering column.

Further, since the outer ring of the bearing is intermittently provided in the circumferential direction, and the inner diameter of the inner circumferential surface thereof is internally fitted and fixed to a fitting portion smaller than the inner diameter of the portion adjacent in the circumferential direction, The outer ring can be fitted into the steering column easily and without rattling.
Furthermore, in the case of this invention, each said fitting part is arrange | positioned unevenly regarding the circumferential direction. For this reason, when these fitting parts are formed by plastic working with relatively large manufacturing errors (size variations), the allowance between the fitting parts and the outer ring of the bearing becomes excessively large. It can be suppressed. As a result, while suppressing an increase in the rotational resistance of the bearing, it is possible to prevent rattling in the required direction and increase the rigidity in the same direction.

For example, according to the invention described in claim 2, since the arrangement of the fitting portions is biased in the vertical direction in the attached state, the vertical direction of the bearing relative to the steering column supported by the vehicle body is related. The support rigidity can be increased, and as a result, the support rigidity in the same direction of the steering shaft with respect to the vehicle body can be increased. As a result, the vibration of the steering wheel can be suppressed regardless of the vertical impact applied during traveling or the like.
In addition, according to the invention described in claim 4, since each stopper portion and each fitting portion can be formed simultaneously (in one step), the number of steps can be reduced, productivity can be improved, and manufacturing can be performed. Cost can be reduced.

FIG. 2 is a partial sectional view (A) showing a first example of an embodiment of the present invention in a state in which a steering column and a bearing are taken out, and a sectional view taken along the line aa in FIG. Similarly, the steering column is shown in a state before assembling the bearing, and is a cross-sectional view (A) from the same direction as FIG. 1, a bb cross-sectional view (B) in FIG. (C) An orthographic projection view (D) showing the shape of the fitting portion in a state where the steering column is viewed from the outside in the radial direction, and an orthographic projection view (E) showing the shape of the stopper portion. The figure (A) similar to (B) of FIG. 2 which shows another example of the shape of a stopper part, and the figure (B) similar to (E). The principal part sectional view showing the state where the stopper part is formed in the end of the steering column. The principal part sectional drawing which similarly shows the state which forms a fitting part. Dd sectional drawing of FIG. Sectional drawing which shows the procedure which press-fits the said bearing in the edge part of a steering column in order of a process. The figure similar to (B) of Drawing 1 showing the 2nd example of an embodiment of the invention. The figure similar to (C) of Drawing 2 showing the 2nd example of an embodiment of the invention. The schematic side view which shows the 1st example of the steering apparatus conventionally known in the state which cut | disconnected a part. Sectional drawing of the rear-end part of a steering column similarly. The perspective view which takes out a steering column and shows the 2nd example of conventional structure. The principal part expanded sectional view similarly shown in the state which fitted the bearing inside the steering column.

[First example of embodiment]
1 to 7 show a first example of an embodiment of the present invention. The feature of the steering device and the manufacturing method thereof according to the present invention including this example is that a ball bearing 19 for rotatably supporting the steering shaft 5 (see FIGS. 10 to 11) is provided inside the steering column 6b. A structure in which such a bearing such as a rolling bearing is fitted and fixed in an axially positioned state is realized at a low cost while ensuring the rigidity of the steering column 6b. Since the structure and operation of the other parts are the same as those of the steering apparatus conventionally known including the first example of the conventional structure shown in FIGS. 10 to 11 described above, illustration and description of equivalent parts are omitted. Or, for simplicity, the following description will focus on the features of this example. The bearing incorporated in the steering device of the present embodiment is not limited to the single row deep groove type ball bearing 19, and various types of bearings can be used as long as they can support a radial load and a thrust load.

  In the case of this example, stoppers are provided at equal intervals (two locations on the opposite side in the radial direction) at a plurality of circumferential positions on the rear end portion of the steering column 6b {right end portion in FIGS. 1 and 2A}. Portions 24a and 24a are provided. Further, a plurality of circumferential locations (three locations in the example shown in the figure) at the opening edge side of both the stopper portions 24a and 24a with respect to the axial direction and the phase with respect to the circumferential direction deviate from both the stopper portions 24a and 24a. ) Are provided with fitting portions 25a and 25a having a smaller inner diameter (diameter of the inscribed circle) than a portion adjacent in the circumferential direction. However, any one of the fitting portions 25a and 25a may have the same phase in the circumferential direction as any one of the stopper portions 24a of the stopper portions 24a and 24a. . In any case, the cross-sectional shape of each of the fitting portions 25a, 25a is a partial arc shape concentric with the main body portion of the steering column 6b.

In the case of this example, the fitting portions 25a and 25a are unevenly arranged in the circumferential direction. Specifically, the arrangement of the fitting portions 25a and 25a in the circumferential direction is set to a position deviated in the vertical direction with the steering column 6b attached to the vehicle body 10 (see FIG. 10). That is, the circumferential spacing of each of the fitting portions 25a, 25a is such that the angle formed by the upper fitting portion 25a and the center of the lower fitting portion 25a, 25a is θ ₁ , fitting portion 25a, the angle between the centers of 25a when the theta _2, the upper fitting portion 25a, the angle theta ₁ relates 25a, the lower side of the fitting portion 25a, than the angle theta ₂ relates 25a together Is also made large (θ ₁ > θ ₂ ), so that they are unevenly arranged in the circumferential direction. That is, the upper fitting portion 25a is present in the vertical direction of the virtual line on M, the lower fitting portion 25a, 25a is slightly from the imaginary line M (θ _2/2 by, for example, 20 It exists at a position inclined in the circumferential direction (about 40 degrees). In other words, two of the three fitting portions 25a, 25a are provided on the lower side of FIG. 2C with the virtual line M in between, and the other one is ( It is provided on the imaginary line M above C). And the space | interval regarding the circumferential direction of the said lower two fitting parts 25a and 25a is each circumferential direction of these lower two fitting parts 25a and 25a and the said upper one fitting part 25a. Is less than the interval.

  The front end surface of the outer ring 20 constituting the ball bearing 19 is abutted against the stopper portions 24a and 24a to position the ball bearing 19 in the axial direction with respect to the steering column 6b. It fits in each fitting part 25a, 25a by interference fitting. Further, in the steering column 6b, a portion of the rear end edge protruding rearward from the rear end face of the outer ring 20 is aligned radially inward with the fitting portions 25a and 25a in the circumferential direction. The caulking portions 26, 26 are formed by plastic deformation. The outer ring 20 is sandwiched between the stopper portions 24a, 24a and the caulking portions 26, 26, thereby preventing the ball bearing 19 from being displaced in the axial direction.

  The steering column 6b constituting the steering device of the present example simultaneously forms the stopper portions 24a and 24a and the fitting portions 25a and 25a by pressing a pipe material such as an electric sewing tube or a drawing tube. To do. Further, the ball bearing 19 is press-fitted into the rear end portion, and at the same time, the rear end edge portion of the steering column 6b is plastically deformed to form the caulking portions 26, 26. Hereinafter, a procedure for manufacturing the steering column 6b and holding and fixing the ball bearing 19 on the rear end portion of the steering column 6b will be described.

  The steering column 6b is first set on a press device 27 as shown in FIGS. 4 to 6, and the stoppers 24a and 24a and the fitting portions 25a and 25a are provided at the rear end of the steering column 6b. Form. The tip of the steering column 6b (upper end in FIGS. 4 to 5) supported by the pressing device 27 in a state where displacement in each direction (axial direction, radial direction and circumferential direction) is prevented is uneven in the circumferential direction. The tip end portion (the lower end portion in FIGS. 4 to 5) of the core 29, which is provided with recesses 28 and 28 that are long in the axial direction, is inserted into a plurality of locations (three locations in the illustrated example). The insertion amount of the core 29 is such that the axial position of the tip surface (the lower end surface in FIGS. 4 to 5) of the core 29 is such that the ball bearing 19 is assembled to the steering column 6b. The outer ring 20 is regulated so as to coincide with the axial position where the front end face of the outer ring 20 is located. In this state, the core 29 is prevented from being displaced by the restraining jig 30 in the radial direction, the circumferential direction, and the axial direction (at least the direction in which the insertion amount of the core 29 increases with respect to the tip of the steering column 6b). .

  Further, a pressing punch 31 is provided at a portion that is radially outward of the steering column 6 b and whose phase in the circumferential direction coincides with the recesses 28, 28 of the core 29. A shearing tool 44 is disposed on each of the two. These pressing punches 31 and both shearing tools 44 are supported so as to be capable of displacement in the radial direction with respect to the pressing device 27. That is, the pressing punches 31 and the shearing tools 44 hold the respective front end surfaces (lower end surfaces in FIG. 5) against the block 32, thereby preventing axial displacement and moving closer to the lower ends of the respective outer peripheral surfaces. The driven side inclined surface 33 provided in the portion is engaged with the driving side inclined surface 35 provided on the inner peripheral surface of the slide blocks 34, 34, respectively. Each of these slide blocks 34, 34 constitutes a press working die set, and is displaced in the vertical direction together with the push plate 36 in accordance with the vertical displacement of the push plate 36 pressed by the ram of the press device. Displacement in the radial direction is prevented by a holding cylinder 37 supported and fixed to the push plate 36. That is, when each slide block 34 is displaced downward in accordance with the downward displacement of the push plate 36, the respective press punches are based on the engagement between the driven side and drive side inclined surfaces 33, 35. 31 and both the shear tools 44 are displaced radially inward. The inner peripheral surface of each pressing punch 31 has a shape that matches the outer peripheral surface of the steering column 6b, and is long in the axial direction at a portion that aligns with the recesses 28, 28 of the core 29. A convex portion 38 having a trapezoidal shape when viewed is provided. On the other hand, the inner peripheral surfaces of the two shearing tools 44 are aligned with the outer peripheral surface of the steering column 6b, and a blade portion 39 is provided at the tip (the lower end in FIG. 4). The pressing punches 31 and the shearing tools 44, each having the shape as described above, are displaced inward in the radial direction as the pressing plate 36 is displaced downward. Then, along with the displacement of each of the pressing punches 31 and the two shearing tools 44 in the radially inward direction, the blade portions 39 of the two shearing tools 44 form notches on the outer peripheral surface of the steering column 6b, A portion adjacent in the axial direction on the center side (lower side in FIG. 4) of the steering column 6b with respect to both incisions is bent and formed (cut and bent) inward in the radial direction. Then, the stopper portions 24 a and 24 a are formed in the portion pressed by the both blade portions 39. At the same time, the convex portion 38 of each pressing punch 31 presses the outer peripheral surface of the steering column 6b to form the fitting portions 25a and 25a. In the case of this example, as shown in FIGS. 1 and 2, the stopper portions 24a and 24a have a quarter-spherical shape. However, these stopper portions 24a and 24a are formed by changing the shape of the both blade portions 39 to increase the circumferential cut length, for example, as shown in FIG. It can also be. In the case of this example, when the fitting portions 25a and 25a are formed, the pressing amount by the pressing punches 31 is gradually decreased toward the rear end edge of the steering column 6b. A tapered guide portion 40 is provided at the rear end portion of each of the fitting portions 25a and 25a so as to be inclined in the radially outward direction toward the rear end edge. For this purpose, the outer peripheral surface of the core 29 and the inner peripheral surface of each pressing punch 31 are formed in a shape that matches the shape of the guide portion 40. Specifically, the height of the portion of the convex portion 38 of each pressing punch 31 that is aligned with each guide portion 40 is gradually lowered as it goes upward in FIG. In FIG. 5, such a shape is omitted.

  As described above, when the stopper portions 24a and 24a and the fitting portions 25a and 25a are formed at the rear end portion of the steering column 6b, the steering column 6b is removed from the press device 27. Remove and move on to the next bearing assembly process. In this bearing assembly step, the ball bearing 19 is assembled to the rear end portion of the steering column 6b by a press-fitting jig 41 as shown in FIG. That is, the annular protrusion 42 provided on the end surface of the press-fitting jig 41 presses the rear end surface of the outer ring 20 of the ball bearing 19 toward the steering column 6b, and the ball bearing 19 is attached to the steering column 6b. Push into the rear end (press-fit). Then, the front end surface of the outer ring 20 is abutted against the stopper portions 24a and 24a to position the ball bearing 19 in the axial direction, and the outer peripheral surface of the outer ring 20 is fixed to the fitting portions 25a and 25a. Fits inside with an interference fit. At the same time, each of the fitting portions 25a in the circumferential direction is provided at the back end portion of the cylindrical surface portion 45 provided on the end surface of the press-fitting jig 41 and having a shape that matches the outer shape of the end portion of the steering column 6b. The outer ring of the steering column 6b is provided by a concave curved surface portion 43 having a partially arcuate cross section, which is an inclined surface portion that is provided in a portion aligned with 25a and is inclined in a radially outward direction toward the tip. The rear edge portion protruding from the rear end surface 20 of the 20 has a portion (guide portion 40 of each of the fitting portions 25a, 25a) aligned with the fitting portions 25a, 25a in the circumferential direction directed radially inward. The caulking portions 26 are formed by plastic deformation. The fitting portions 25a and 25a for holding the outer ring 20 in an interference fit are intermittently provided with respect to the circumferential direction. Therefore, even if the tightening margin is not strictly managed (dimensional accuracy) The outer ring 20 can be easily fitted into the rear end portion of the steering column 6b easily and without rattling. Further, by adjusting the circumferential length of the notches formed on the outer peripheral surface of the steering column 6b, the width in the circumferential direction of the fitting portions 25a, 25a is adjusted, and the steering column of the ball bearing 19 is adjusted. The holding force with respect to 6b can be made into a suitable magnitude | size.

  According to the steering device and the manufacturing method thereof of the present invention configured as described above, a structure in which the steering shaft 5 is rotatably supported inside the steering column 6b via the ball bearings 19 is provided. This can be realized at a low cost while ensuring the rigidity of 6b. That is, in the case of this example, the stopper portions 24a, 24a for axial positioning of the ball bearing 19 and the fitting portions 25a, 25a for fitting the ball bearing 19 are 1 Form in the process. Further, the ball bearing 19 is press-fitted into the rear end portion of the steering column 6b, and at the same time, the caulking portions 26 and 26 for preventing the ball bearing 19 from coming off are formed at the rear end portion of the steering column 6b. For this reason, the number of steps can be reduced compared to the second example of the conventional structure shown in FIGS. 12 to 13 described above, the productivity can be improved, and the manufacturing cost can be suppressed.

Further, while forming circumferential incisions on the outer peripheral surface of the steering column 6b, the both stoppers are formed by bending the axially adjacent portions on the center side of the steering column 6b with respect to both incisions. Portions 24a and 24a are formed. That is, unlike the second example of the conventional structure shown in FIGS. 12 to 13 described above, it is not necessary to provide the opening 23 penetrating in the radial direction on the outer peripheral surface of the steering column 6a. For this reason, a decrease in the rigidity of the steering column 6b can be minimized.
Furthermore, since the fitting portions 25a and 25a are unevenly arranged in the circumferential direction, the rigidity in the required direction can be increased. In particular, in the case of this example, the arrangement of the fitting portions 25a and 25a is biased in the vertical direction in the attached state. For this reason, the support rigidity in the vertical direction of the ball bearing 19 with respect to the steering column 6b supported by the vehicle body 10 can be increased, and consequently, the steering shaft 5 (see FIGS. 10 to 11) with respect to the vehicle body 10 has the same direction. Support rigidity can be increased. As a result, the vibration of the steering wheel 1 (see FIG. 10) can be suppressed regardless of the vertical impact applied during traveling or the like.
Further, when the fitting portions 25a and 25a are provided, the guide portions 40 are provided by reducing the pressing amount of the rear end edges of the fitting portions 25a and 25a. For this reason, when the ball bearing 19 is press-fitted into the rear end portion of the steering column 6b, the fitting portions 25a and 25a are not subject to cutting with high machining accuracy, and there is a manufacturing error (dimensional variation). In the case of the structure of this example formed by relatively large plastic working, this press-fitting operation can be easily performed.

[Second Example of Embodiment]
8 to 9 show a second example of the embodiment of the present invention. In the case of this example, the fitting portions 25b and 25b provided at four locations in the circumferential direction of the rear end portion of the steering column 6c are arranged in the vertical direction with the steering column 6c attached to the vehicle body 10 (see FIG. 10). The arrangement is biased. That is, when it is assumed that the rear end portion of the steering column 6c is divided into two by a virtual line N in the horizontal direction (left-right direction in FIG. 9), as shown in FIG. An angle θ ₃ (for example, 50 to 70 degrees) formed by each of the centers of the portions 25a and 25a is an angle θ ₄ (for example, formed by each of the virtual line M in the vertical direction and the centers of the respective fitting portions 25a and 25a. 40 to 20 degrees) (θ ₃ > θ ₄ ). Thereby, these fitting parts 25a and 25a are provided in the state biased to the position close | similar to the virtual line M of the said up-down direction.

Further, in the case of this example, the caulking portions 26a and 26a for preventing the ball bearing 19 assembled to the rear end portion of the steering column 6c from being connected to the circumferential direction in the rear end edge portion of the steering column 6c. The phase is provided at a portion where both the stopper portions 24a and 24a coincide. Both the caulking portions 26a and 26a are formed at the same time when the ball bearing 19 is press-fitted into the rear end portion of the steering column 6c, similarly to the caulking portion 26 (see FIG. 1) of the first example of the embodiment described above. To do. The caulking portion for preventing the ball bearing 19 from coming off is provided on the entire periphery of the rear end edge portion of the steering column 6c (regardless of the presence of the guide portion provided at the rear end portion of the fitting portion). Or it can also be provided in a part of the circumferential direction.
Since the configuration and operation of the other parts are the same as in the first example of the embodiment described above, overlapping illustrations and descriptions are omitted.

The structure and the manufacturing method shown as each example of the embodiment of the present invention described above can be applied not only to the rear end portion of the steering column but also to the front end portion or the intermediate portion. In this case, for example, the bearing can be a radial needle bearing. In addition, when applied to the intermediate portion, it is impossible to prevent the bearing from coming off by caulking the outer peripheral edge of the end portion of the steering column. In this case, for example, after the bearing is fitted and fixed to the inner peripheral surface of the fitting portion, a part of the steering column is pressed inward in the radial direction to be plastically deformed, and a convex portion is formed on the inner peripheral surface of the steering column. To prevent it from coming off.
The present invention is not limited to a steering column (outer column or inner column) provided with a telescopic mechanism as in the first example of the conventional structure shown in FIG. 10, but is applied to a steering column having no telescopic mechanism. You can also do things.

DESCRIPTION OF SYMBOLS 1 Steering wheel 2 Steering gear unit 3 Input shaft 4 Tie rod 5 Steering shaft 6, 6a-6c Steering column 7 Universal joint 8 Intermediate shaft 9 Universal joint 10 Car body 11 Axis 12 Support bracket 13 Outer column 14 Inner column 15 Outer tube 16 Inner shaft DESCRIPTION OF SYMBOLS 17 Electric motor 18 Step part 19 Ball bearing 20 Outer ring 21 Inner ring 22 Tongue piece 23 Opening part 24, 24a Stopper part 25, 25a, 25b Fitting part 26, 26a Caulking part 27 Press device 28 Recess 29 Core 30 Holding jig 31 Punch 32 Holding block 33 Driven side inclined surface 34 Slide block 35 Driving side inclined surface 36 Push plate 37 Holding cylinder 38 Convex part 39 Blade part 40 Guide part 41 Press-fitting device 42 Projection line 43 Concave surface part 44 Shearing tool 45 Cylindrical surface

Claims (7)

In a steering apparatus comprising a hollow cylindrical steering column supported by a vehicle body, a steering wheel fixed to a rear end portion, and a steering shaft rotatably supported via a bearing in the steering column.
The bearing has an end surface of the outer ring constituting the bearing at a center side of the steering column with respect to the circumferential notches provided at a plurality of circumferential positions of the steering column, and in the axial direction of the respective notches. Axial positioning is achieved by abutting against a plurality of stopper portions provided by bending the adjacent portions radially inward, and the outer ring of the bearing is connected to the outer peripheral surface of the steering column. A plurality of circumferential positions on the opening side of the steering column with respect to the incisions in the axial direction are internally fitted and fixed to a plurality of fitting portions provided by plastically deforming radially inwardly. A steering device characterized in that the fitting portions are arranged unevenly in the circumferential direction.   The steering device according to claim 1, wherein the arrangement of the fitting portions is biased in the vertical direction in the attached state.   The bearing is fitted and fixed to an end portion of the steering column, and a retaining portion formed by plastically deforming an end edge of the steering column radially inward is used to prevent the bearing from coming off. Item 3. The steering device according to any one of Items 1-2.   It is a manufacturing method of the steering device given in any 1 paragraph of Claims 1-3, Comprising: With respect to each of these incisions, making incisions of the peripheral direction in a plurality of places in the peripheral direction of the outer peripheral surface of said steering column. In addition, a stopper portion is provided by bending a portion adjacent in the axial direction on the center side of the steering column inward in the radial direction, and at the same time, each of the notches in the axial direction on the outer peripheral surface of the steering column. On the other hand, on the opening side of the steering column, by pressing a plurality of portions that are not uniform in the circumferential direction toward the inside in the radial direction and plastically deforming, the inner diameter of the inner circumferential surface of the portion adjacent to the circumferential direction is reduced. A method for manufacturing a steering device, wherein a fitting portion smaller than an inner diameter is provided.   In the steering column, a core provided with recesses at a plurality of positions that are uneven in the circumferential direction of the outer peripheral surface is positioned in a state where the axial position of the tip surface of the core is assembled in the steering column. The insertion amount is restricted so that the end face of the outer ring of the bearing coincides with the axial position, and the steering column is radially outward and the phase in the circumferential direction coincides with the recess of the core. Press punches are placed on the parts to be operated, and blades of the shearing tool are arranged at a plurality of locations in the circumferential direction. These pressing punches and shearing tools are supported by the push plates on the driven side inclined surfaces provided on the respective outer peripheral surfaces. By engaging with the drive-side inclined surface of the slide block that is displaced together with the push plate, the push plate is displaced in the radial direction as the push plate is displaced in the vertical direction, and the push plate is displaced downward. The pressing punch and the shearing tool are displaced inward in the radial direction by pressing the outer peripheral surface of the steering column by a convex portion provided on the inner peripheral surface of the pressing punch, and the fitting portions are And forming a notch in the outer peripheral surface of the steering column by the blade portion of the shearing tool, and displacing the blade portion radially inward along the tip surface of the core, and a portion adjacent to the notch The method for manufacturing a steering device according to claim 4, wherein each of the stopper portions is formed by bending the lens inward in the radial direction.   The stoppers and the fitting parts are formed at the end of the steering column, and when the bearing is pressed into the end of the steering column in the axial direction by a press-fitting jig, the press-fitting treatment is performed. A crimped portion is formed by plastically deforming an end edge of the steering column radially inward by an inclined surface portion that is provided at a tip portion of the tool and is inclined in a radially outward direction toward the tip. Item 6. The method for manufacturing a steering device according to any one of Items 4 to 5.   By gradually reducing the amount of pressing that presses the outer peripheral surface of the steering column by the convex portion of each pressing punch toward the edge of the steering column, The method for manufacturing a steering device according to claim 6, further comprising a tapered guide portion that is inclined in a direction toward the radially outward direction toward the opening edge.

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