JP6390904B2 - Steering device - Google Patents

Description

  The present invention relates to a steering device.

  Patent Document 1 proposes a steering device in which a sensor housing is integrally formed by expanding the axial lower portion of a column tube by plastic deformation. The column housing and the reduction gear housing are connected to each other by press-fitting and engaging the cylindrical upper housing of the reduction gear housing with the sensor housing of the column tube.

JP 2010-247790 A

As the column tube, a material excellent in malleability and ductility that can form a sensor housing by expanding the tube is used. However, such materials generally have low hardness and deformation strength. Therefore, the connection strength of the sensor housing (column housing) with respect to the upper housing (reduction gear housing) tends to be low.
An object of the present invention is to provide a steering device that can secure the connection strength of the column tube to the reduction gear housing even when a column tube capable of forming a sensor housing by pipe expansion is used.

  The invention of claim 1 has an axial direction (X) in the steering device (1) for transmitting the rotation of the assist motor (6) to the steering shaft (3) by reducing the rotation of the assist motor (6). A column tube (13) which includes a sensor housing (15; 15P) expanded by plastic deformation at the lower portion, accommodates a torque sensor (8) in the sensor housing, and rotatably supports the steering shaft through the axial direction. ) And a cylindrical portion (36) directly or indirectly press-fitted into the inner periphery (RRb) of the connection region (RR; RRP) provided in a predetermined range from the lower end (15L) in the axial direction of the sensor housing. And a reduction gear housing (14) for housing the reduction gear, and an outer periphery (RRa) of the connection region of the column tube, Reinforcing cylinder win; and (41 41P), to provide a steering apparatus (1) comprising a.

The reinforcing outer cylinder (41) as the reinforcing cylinder, the reinforcing inner cylinder (42) press-fitted and engaged with the inner periphery of the connection region, the reinforcing outer cylinder, and the reinforcing inner cylinder, as in claim 2. A double cylinder (40) including an annular wall (43) connecting the two may be provided.
According to a third aspect of the present invention, the connection region of the sensor housing may be lightly press-fitted between an inner periphery (41b) of the reinforcing outer cylinder and an outer periphery (42a) of the reinforcing inner cylinder.

According to a fourth aspect of the present invention, the annular wall of the double cylinder contacts the lower end in the axial direction of the sensor housing, and the reinforcing inner cylinder extends from the upper end in the axial direction (42U) and the upper end in the axial direction. And a positioning convex edge (44) for positioning the torque sensor in the axial direction.
According to a fifth aspect of the present invention, an elastic body (45) interposed between the positioning convex edge and the torque sensor may be provided.

  As in claim 6, a wiring (16) extending from the torque sensor extends outside the sensor housing through an opening (17) provided in the sensor housing, the opening being an axis of the sensor housing. You may open | release to the direction lower end.

  According to the first aspect of the present invention, the cylinder portion of the reduction gear housing is press-fitted into the inner periphery of the connection region of the sensor housing of the column tube directly or indirectly. On the other hand, the expansion of the connecting region is suppressed by the reinforcing cylinder fitted to the outer periphery of the connecting region. Therefore, even when a material having a malleability suitable for pipe expansion by plastic deformation is used as the material of the column tube, since the diameter of the connection area is suppressed by the reinforcing cylinder, the connection area to the cylinder portion of the reduction gear housing is reduced. Connection strength is secured.

According to the invention of claim 2, since the double cylinder including the reinforcing outer cylinder as the reinforcing cylinder and the reinforcing inner cylinder press-fitted and engaged with the connection area is configured, the diameter expansion of the connection area is suppressed. The effect can be increased.
According to the invention of claim 3, the sensor housing and the double cylinder can be handled as a subassembly, and the assemblability is good.

According to the invention of claim 4, the torque sensor is pivoted by the positioning convex edge extending from the reinforcing inner cylinder of the double cylinder in a state where the lower end of the sensor housing of the annular wall of the double cylinder is in contact. Can be positioned in the direction.
According to the invention of claim 5, the dimensional error of each component can be absorbed by the elastic body interposed between the positioning convex edge and the torque sensor.

  According to the sixth aspect of the present invention, when the torque sensor is attached to the sensor housing during assembly, the wiring extending from the torque sensor can be attached to the opening of the sensor housing. Thereby, assemblability improves.

It is a schematic sectional drawing of the principal part of the steering apparatus of one Embodiment of this invention. (A) is an exploded sectional view of the principal part of a steering device, (b) is a schematic side view of a sensor housing. It is an expanded sectional view of the important section of a steering device. (A), (b) is sectional drawing of a column tube and a torque sensor, and has shown sequentially the operation | movement which incorporates a torque sensor in a column tube. It is a schematic sectional drawing of the subassembly with which the torque sensor and the double cylinder were assembled | attached to the column tube. (A) is sectional drawing of the reinforcement cylinder and elastic body of another embodiment of this invention, (b) is an end view of the said reinforcement cylinder, (c) is a sensor housing press-fitted in the said reinforcement cylinder. It is the schematic seen from the axial direction lower end side.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view of a main part of a steering apparatus according to an embodiment of the present invention. Referring to FIG. 1, a steering device 1 includes a steering shaft 3 having a steering member 2 such as a steering wheel connected to one end, and a rack and pinion mechanism connected to the steering shaft 3 via an intermediate shaft 4. The steering mechanism 5 is provided.

The steering device 1 is configured as an electric power steering device. That is, the steering device 1 includes an assist motor 6 that generates an assist force, and a speed reducer 7 that decelerates and transmits the output rotation of the assist motor 6 to the steering shaft 3.
The steering device 1 also includes a torque sensor 8 that detects steering torque, and an ECU (Electronic Control) that controls driving of the assist motor 6 (assist control) based on a torque detection result by the torque sensor 8 and a vehicle speed detection result by the vehicle speed sensor 9. Unit) 10.

Further, the steering device 1 includes a steering column 12 that is rotatably supported by inserting the steering shaft 3 in the axial direction X and is fixed to the vehicle body 11. The steering column 12 includes a column tube 13 and a speed reducer housing 14 that is connected to the lower portion in the axial direction of the column tube 13 and accommodates the speed reducer 7.
The column tube 13 includes a sensor housing 15 that is expanded by plastic deformation and accommodates the torque sensor 8 at a lower portion in the axial direction. The torque sensor 8 has an annular shape surrounding the steering shaft 3 and is fitted and held on the inner periphery 15 b of the sensor housing 15.

A wiring 16 extending outward in the radial direction of the torque sensor 8 is connected to the torque sensor 8. The wiring 16 extends outside the sensor housing 15 through the opening 17 of the sensor housing 15 and is connected to the ECU 10. The output signal of the torque sensor 8 is input to the ECU 10 via the wiring 16.
As shown in FIG. 2A, which is an exploded sectional view, and FIG. 2B, which is a schematic side view of the sensor housing 15, the opening 17 of the sensor housing 15 extends from the opening 17 in the axial direction of the sensor housing 15. The lower end 15L is open to the lower end 15L in the axial direction of the sensor housing 15 via a communication groove 151 extending in the axial direction X.

When the torque sensor 8 is assembled in the sensor housing 15 of the column tube 13, as shown in FIGS. 4 (a) and 4 (b) sequentially, the torque sensor 8 is moved in the axial direction X and simultaneously the wiring 16 Is inserted into the opening 17 through the communication groove 151. Therefore, workability is good.
On the other hand, if the opening is not opened at the lower end in the axial direction of the sensor housing, first, the wiring is inserted into the opening with the torque sensor tilted, and then the torque sensor is turned on. The work to insert through the sensor housing while gradually raising from the tilted state is necessary, and the workability is poor.

  Referring again to FIG. 1, the steering shaft 3 includes an input shaft 18 connected to the steering member 2, an output shaft 19 connected to the intermediate shaft 4, and a torsion bar that connects the input shaft 18 and the output shaft 19 on the same axis. 20. When steering torque is input to the input shaft 18, the torsion bar 20 is elastically twisted and deformed, whereby the input shaft 18 and the output shaft 19 rotate relative to each other. The torque sensor 8 detects a steering torque based on the relative rotation between the input shaft 18 and the output shaft 19.

The torque sensor 8 detects the steering torque based on the magnetic flux generated in the magnetic circuit forming mechanism 21 provided in association with the input shaft 18 and the output shaft 19.
As shown in FIG. 3, which is an enlarged cross-sectional view, the magnetic circuit forming mechanism 21 includes a multipolar magnet 22 connected to one of the input shaft 18 and the output shaft 19 so as to be integrally rotatable, and a magnetic field of the multipolar magnet 22. And a pair of magnetic yokes 23 that are rotatably connected to the other of the input shaft 18 and the output shaft 19 to form a magnetic circuit.

  The torque sensor 8 includes a magnetic flux collecting ring 24 as a pair of magnetic flux collecting elements magnetically coupled to the pair of magnetic yokes 23 and a magnetic flux between magnetic flux collecting portions (not shown) of the pair of magnetic flux collecting rings 24. A magnetic flux detection element (not shown) such as a Hall IC to be detected and a resin-made annular main body 26 for holding them are provided. The wiring 16 extends radially outward from the main body 26 of the torque sensor 8.

As shown in FIG. 1, the speed reducer 7 meshes with a drive gear 27 such as a worm shaft that is rotationally driven by the assist motor 6 and the drive gear 27, and is connected to the outer periphery of the output shaft 19 of the steering shaft 3 so as to be integrally rotatable. And a driven gear 28 such as a worm wheel.
The reduction gear housing 14 is formed by integrally forming a cylindrical drive gear housing portion 29 for housing and holding the drive gear 27 and a driven gear housing portion 30 for housing and holding the driven gear 28 in a cross shape with a single material. ing.

The driven gear housing 30 rotatably supports the output shaft 19 of the steering shaft 3 via an upper bearing 31 and a lower bearing 32 disposed above and below the driven gear 28 in the axial direction X.
The driven gear accommodating portion 30 includes an upper housing 33 and a lower housing 34 that are connected to each other. The upper housing 33 rotatably supports the output shaft 19 via the upper bearing 31. The lower housing 34 rotatably supports the output shaft 19 via the lower bearing 32.

As shown in FIG. 3, the inner rings 31 b and 32 b of the upper bearing 31 and the lower bearing 32 are fitted to the output shaft 19 so as to be integrally rotatable.
The upper housing 33 includes an outer cylinder 35 that is press-fitted into the upper inner periphery of the lower housing 34, an inner cylinder 36 that holds the outer ring 31a of the upper bearing 31 on the inner periphery 36b, and shafts of the outer cylinder 35 and the inner cylinder 36. And an annular wall 37 for connecting the lower ends in the direction. The outer cylinder 35 of the upper housing 33 is press-fitted into the inner periphery of the upper part of the lower housing 34, so that the inner cylinder 36 of the upper housing 33 is reduced in diameter.

The inner cylinder 36 (corresponding to the cylinder portion) of the upper housing 33 of the speed reducer housing 14 is indirectly press-fitted to a connection region RR provided in a predetermined range from the axial lower end 15L of the sensor housing 15 of the column tube 13. Are combined.
Specifically, the steering device 1 includes a double cylinder 40 for reinforcing the connection region RR of the column tube 13. The double cylinder 40 is fitted to the outer periphery RRa of the connection region RR, and includes a reinforcement outer cylinder 41 as a reinforcement cylinder that suppresses the diameter expansion of the connection region RR, a reinforcement inner cylinder 42, a reinforcement outer cylinder 41, and a reinforcement inner cylinder. And an annular wall 43 that connects between the lower ends in the axial direction with 42. The reinforcing inner cylinder 42 is press-fitted into the inner periphery RRb of the connection region RR.

As shown in FIGS. 2A and 3, the connection region RR of the sensor housing 15 is lightly press-fitted between the inner circumference 41 b of the reinforcing outer cylinder 41 and the outer circumference 42 a of the reinforcing inner cylinder 42. The annular wall 43 of the double cylinder 40 is in contact with the lower end 15 </ b> L in the axial direction of the sensor housing 15.
The reinforcing inner cylinder 42 includes an axial upper end 42U and a positioning convex edge 44 that extends from the axial upper end 42U and positions the torque sensor 8 in the axial direction X. The positioning convex edge 44 is, for example, an annular flange that extends radially inward from the axial upper end 42U of the reinforcing inner cylinder 42.

  The positioning convex edge 44 has a facing surface 44 a that faces one end surface 8 a of the torque sensor 8 (corresponding to the end surface of the main body 26). An elastic body 45 made of rubber or resin is interposed between the facing surface 44 a of the positioning convex edge 44 and the one end surface 8 a of the torque sensor 8. The elastic body 45 may be bonded to the facing surface 44 a of the positioning convex edge 44. The adhesion may be vulcanization adhesion when the elastic body 45 is rubber. The elastic body 45 may be bonded to one end surface 8 a of the torque sensor 8.

As shown in FIG. 4B, a positioning protrusion 152 is formed on the inner periphery 15 b of the sensor housing 15 to contact the other end surface 8 b of the torque sensor 8 and position the torque sensor 8 in the axial direction X. .
According to the present embodiment, the cylinder portion of the reduction gear housing 14 (the inner cylinder 36 of the upper housing 33) with respect to the inner periphery RRb of the connection region RR of the sensor housing 15 formed by expanding the tube tube 13 by plastic deformation. Are indirectly press-fitted.

  On the other hand, the reinforcement cylinder (reinforcement outer cylinder 41) fitted to the outer periphery RRa of the connection region RR suppresses the diameter expansion of the connection region RR. Accordingly, even when a material having a malleability suitable for pipe expansion by plastic deformation is used as the material of the column tube 13, the diameter of the connection region RR is suppressed by the reinforcing cylinder (reinforcing outer cylinder 41). The connection strength of the connection region RR with respect to the cylinder portion (inner cylinder 36) of the machine housing 14 is ensured.

Further, since the double cylinder 40 is configured including the reinforcing outer cylinder 41 as a reinforcing cylinder and the reinforcing inner cylinder 42 press-fitted and engaged with the inner periphery RRb of the connecting region RR, the diameter of the connecting region RR is increased. The effect which suppresses can be made high.
Further, the connection region RR of the sensor housing 15 is lightly press-fitted between the inner periphery 41 b of the reinforcing outer cylinder 41 and the outer periphery 42 a of the reinforcing inner cylinder 42. Therefore, at the time of assembly, the sensor housing 15 and the double cylinder 40 can be handled as the subassembly SA (see FIG. 5), and the assemblability is good.

Further, as shown in FIG. 3, the annular wall 43 of the double cylinder 40 is a positioning protrusion that extends from the reinforcing inner cylinder 42 of the double cylinder 40 in a state where the annular wall 43 is in contact with the axial lower end 15 </ b> L of the sensor housing 15. The torque sensor 8 can be positioned in the axial direction X by the edge 44.
Further, the dimensional error of each component can be absorbed by the elastic body 45 interposed between the positioning convex edge 44 and the torque sensor 8.

  Further, the opening 17 of the sensor housing 15 is opened to the lower end 15 </ b> L in the axial direction of the sensor housing 15 through the communication groove 151. Therefore, as shown in FIGS. 4A and 4B, when the torque sensor 8 is mounted on the sensor housing 15 in the axial direction X during assembly, the wiring 16 extending from the torque sensor 8 is simultaneously connected to the sensor housing 15. It can be attached to the opening 17. Thereby, assemblability improves.

Even if the communication groove 151 is formed at the lower end 15L in the axial direction of the sensor housing 15, since it is reinforced by the reinforcing cylinder (reinforcing outer cylinder 41), it is possible to suppress a decrease in connection strength. In particular, since the double tube 40 that fits inside and outside the connection region RR of the sensor housing 15 is used, high connection strength can be ensured.
The present invention is not limited to the above-described embodiment. For example, the reinforcing inner cylinder is eliminated, and the cylinder portion of the reduction gear housing (the inner cylinder of the upper housing) is directly press-fitted to the inner periphery of the connection region of the sensor housing. May be combined.

In this case, as shown in FIGS. 6A and 6B, a plurality of connecting portions 46 for connecting the axial character upper ends 41PU of the single reinforcing cylinder 41P corresponding to the reinforcing outer cylinder and the positioning convex edge 44 are provided. A plurality of arcuate insertion holes 47 arranged in the circumferential direction and arranged in the circumferential direction may be formed between adjacent connecting portions 46.
6C, the connection region RRP of the sensor housing 15P is divided into a plurality of arc-shaped portions 153 that are press-fitted into the reinforcing cylinder 41P through the corresponding insertion holes 47. A slit 154 extending in the axial direction from the lower end in the axial direction of the sensor housing 15P is formed between the adjacent arc-shaped portions 153.

When the reinforcing inner cylinder is abolished, the annular wall may be abolished as shown in FIGS. 6A and 6B. However, the annular wall is provided as in FIG. An axial positioning function with respect to the sensor housing may be performed.
In the torque sensor 8, a magnetoresistive element may be used instead of the Hall IC. In addition, the present invention can be variously modified within the scope of the matters described in the claims.

  DESCRIPTION OF SYMBOLS 1 ... Steering device, 2 ... Steering member, 3 ... Steering shaft, 4 ... Intermediate shaft, 5 ... Steering mechanism, 6 ... Assist motor, 7 ... Reduction gear, 8 ... Torque sensor, 8a ... One end surface, 10 ... ECU , 12 ... Steering column, 13 ... Column tube, 14 ... Reducer housing, 15; 15P ... Sensor housing, 15b ... Inner circumference, 15L ... Lower end in the axial direction, 151 ... Communication groove, 16 ... Wiring, 17 ... Opening, 18 DESCRIPTION OF SYMBOLS ... Input shaft, 19 ... Output shaft, 20 ... Torsion bar, 21 ... Magnetic circuit formation mechanism, 30 ... Driven gear accommodating part, 31 ... Upper bearing, 32 ... Lower bearing, 33 ... Upper housing, 34 ... Lower housing, 35 ... Outer cylinder 36 ... Inner cylinder (cylinder part) 36b ... Inner circumference 40 ... Double cylinder 41 ... Reinforcement outer cylinder 41P ... Reinforcement cylinder 41b ... Inner circumference 42 ... Reinforcement inner cylinder 42a ... Outer circumference 42U ... upper axial end, 43 ... annular wall, 44 ... positioning convex edge, 45 ... elastic body, RR; RRP ... connecting region, RRa ... outer periphery, RRb ... inner circumferential, SA ... sub-assembly, X ... axial direction

Claims (6)

In the steering device that decelerates the rotation of the assist motor by a reduction gear and transmits it to the steering shaft.
A column tube having an axial direction and including a sensor housing expanded by plastic deformation at a lower portion in the axial direction, accommodating a torque sensor in the sensor housing, and rotatably supporting the steering shaft through the axial direction;
A speed reducer housing containing the speed reducer, including a cylindrical portion that is directly or indirectly press-fitted into an inner periphery of a connection region provided in a predetermined range from the lower end in the axial direction of the sensor housing;
A steering apparatus comprising: a reinforcing cylinder that is fitted to an outer periphery of the connection region of the column tube and suppresses a diameter expansion of the connection region.   The reinforcing outer cylinder as the reinforcing cylinder according to claim 1, a reinforcing inner cylinder press-fitted into an inner periphery of the connection region, and an annular wall connecting the reinforcing outer cylinder and the reinforcing inner cylinder. A steering device having a double cylinder.   The steering device according to claim 2, wherein the connection region of the sensor housing is lightly press-fitted between an inner periphery of the reinforcing outer cylinder and an outer periphery of the reinforcing inner cylinder. In Claim 2 or 3, the annular wall of the double cylinder abuts on the lower end in the axial direction of the sensor housing,
The reinforcing inner cylinder is a steering device including an axial upper end and a positioning convex edge that extends from the axial upper end and positions the torque sensor in the axial direction.   The steering apparatus according to claim 4, further comprising an elastic body interposed between the positioning convex edge and the torque sensor. The wiring extending from the torque sensor according to any one of claims 1 to 5 extends outside the sensor housing through an opening provided in the sensor housing.
The opening is a steering device that is open to an axial lower end of the sensor housing.

Images