JP3530055B2 - motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor used in an electric power steering apparatus for assisting an operating force of a steering wheel of a vehicle, for example.

[0002]

2. Description of the Related Art FIG. 8 is a perspective view showing a state in which a motor 1 for a conventional electric power steering apparatus is used. The motor 1 is connected to a gear box 3 attached to the end of the column 2.

FIG. 9 is a side sectional view of the motor 1. The motor 1 has a cylindrical yoke 4, a four-pole field permanent magnet 5 fixed in the yoke 4 so as to face each other, and a yoke 4. The output shaft 8 whose one end is rotatably supported by the first bearing 7 housed in the bearing housing part 6, the armature 9 fixed to this output shaft 8, and the one end fixed to the output shaft 8. A commutator 10, a brush 12 that abuts on the surface of the commutator 10 by the elastic force of a spring 11, a brush holder 13 that holds the brush 12, a housing 15 that is integrated with the yoke 4 by a screw 14, The second fixed to the center of the housing 15 and rotatably supporting the other end of the output shaft 8.
Bearing 16 and a support 17 press-fitted and fixed to the end of the output shaft 8 and a boss 18 press-fitted into the support 17.
And a grommet 20 through which the lead wire 19 penetrates. The armature 9 includes a core 21 having a plurality of slots extending in the axial direction, and a winding wire 22 configured by winding a conductor wire in the slots in a heavy winding method.

FIG. 10 shows the support 17 and the boss 18 shown in FIG.
It is a cross-sectional view of the boss 18 is pressed into the support 17,
Further, since the steering side input shaft 23 is spline-coupled to the boss 18, the support 17 is, for example, an HRB 80.
The hardness of the boss 18 is higher than that of the boss 18, for example, HRC30.

In the motor 1 having the above structure, the armature 9 is rotated together with the output shaft 8 by electromagnetic action by supplying a current to the winding wire 22 from the lead wire 19 through the brush 12 which contacts the commutator 10. The rotational force of the output shaft 8 is transmitted to the input shaft 23 that is splined to the boss 18, and is used to assist the operating force of the handle 24.

[0006]

In the motor 1 having the above structure, the output shaft 8 is press-fitted into the support 17 and the input shaft 2 is also inserted.
Since the 3 and the boss 18 are spline-bonded, it is necessary to change the hardness of the support 17 and the boss 18, and the boss 18 has a higher hardness than the support 17 and is hardened. As described above, since the support 17 and the boss 18 have different hardnesses, it is necessary to prepare two parts having different hardnesses, which causes a problem that the number of parts increases. Further, in order to smoothly press-fit and support the support 17 and the boss 18, a higher processing accuracy is required. In addition, support 17 and boss 18
There is also a problem in that a work process of press-fitting and fitting the and is necessary.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and a connecting member for connecting an output shaft and an input shaft can be integrated to reduce the number of parts and working steps. Another object of the present invention is to obtain a motor having a connecting member that does not require high component accuracy.

[0008]

A motor according to claim 1 of the present invention includes a cylindrical yoke, an output shaft rotatably provided on a central axis line in the yoke, and fixed to the output shaft. An armature, and a connecting member for transmitting the rotational torque of the output shaft to the input shaft, the connecting member having a press-fitting portion in which the output shaft is press-fit with an interference fit, and a hardness engaged with the input shaft. After quenching , the engaging part that is higher than the press-fitting part
The hardness of the sintered metal material is high and the hardness after quenching is not so
It is formed integrally with a sintered metal material that does not rise .

According to a second aspect of the present invention, there is provided a cylindrical yoke, an output shaft rotatably provided on a central axis of the yoke, an armature fixed to the output shaft, and a rotation of the output shaft. A connecting member that transmits torque to the input shaft, wherein the connecting member has a press-fitting portion into which the input shaft is press-fitted with an interference fit, and an engaging portion that is engaged with the output shaft and has a hardness higher than that of the press-fitting portion. However, a sintered metal material with high hardness after quenching
And a sintered metal material whose hardness does not increase so much after quenching
Are integrally molded by the following.

In the motor according to the third aspect, the press-fitting portion has a hole.

In the motor according to claim 4, the engaging portion has a spline portion.

In the motor according to claim 5, the engaging portion has a spline hole.

In the motor according to the sixth aspect, the engaging portion has a convex portion that engages with the groove portion formed at the end portion of the input shaft.

In the motor according to the seventh aspect, the engaging portion has a groove portion that engages with the convex portion formed at the end portion of the input shaft.

According to another aspect of the motor of the present invention, the input shaft is a shaft for a steering device that transmits a rotational force to the steering wheel.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Hereinafter, a motor for an electric power steering apparatus according to the present invention will be described, and the same or corresponding members as those in the related art will be denoted by the same reference numerals. 1 is a side sectional view of a motor according to a first embodiment of the present invention. The motor 30 includes a cylindrical yoke 4 and
A four-pole field permanent magnet 5 fixed to face the inside of the yoke 4, and an output shaft 8 whose one end is rotatably supported by a first bearing 7 housed in a bearing housing 6 of the yoke 4. An armature 9 fixed to the output shaft 8, a commutator 10 fixed to one end of the output shaft 8, and a brush 12 abutting on the surface of the commutator 10 by an elastic force of a spring 11.
And a brush holder 13 holding the brush 12, and a housing 15 integrated with the yoke 4 by screws 14.
A second bearing 16 fixed to the center of the housing 15 and rotatably supporting the other end of the output shaft 8, a connecting member 31 press-fitted and fixed to the end of the output shaft 8, and a lead wire 19.
And a grommet 20 penetrating therethrough. The armature 9 includes a core 2 having a plurality of slots extending in the axial direction.
1 and a winding wire 22 configured by winding a conductor wire in a slot in a double winding method.

FIG. 2 is a sectional view of the connecting member 31 shown in FIG. 1. The connecting member 31 has a press-fitting portion 32 having a hole 39 press-fitted into the output shaft 8 by a tight fit, and the hole 3 of the press-fitting portion 32.
9, the input shaft 23 has a spline hole 33 into which the input shaft 23 is spline-engaged, and an engaging portion 34 having a hardness higher than that of the press-fitting portion 32 is provided.

This connecting member 31 is shown in FIGS.
It is manufactured according to the procedure of (c). First, the first mold 4
0, the second mold 41 and the core rod 42 are filled with a sintered metal material containing iron-based metal as a main component containing molybdenum and nickel and having high hardness after quenching. Next, the first die 40 and the core rod 42 are raised, and the newly formed space between the first die 40 and the core rod 42 is filled with an iron-based sintered metal material whose hardness after quenching does not increase so much. Is filled. After that, pressurize and sinter under high temperature,
The connecting member 31 including the press-fitting portion 32 and the engaging portion 34 is formed.

In the motor 30 having the above structure, the lead wire 19
By supplying an electric current to the winding wire 22 through the brush 12 that abuts on the commutator 10, the armature 9 rotates together with the output shaft 8 by an electromagnetic action. The press-fitting portion 32 of the connecting member 31 is press-fitted into the output shaft 8 and the engaging portion 34
Since the input shaft 23 is splined to the spline hole 33, the rotational torque of the output shaft 8 is transmitted to the input shaft 23 and assists the operating force of the handle 24.

In this embodiment, the connecting member 31 is integrally formed by sintering, and the number of parts is reduced from one member of the conventional support 17 and the boss 18 to one member.
Further, it is not necessary to press-fit the support 17 and the boss 18 smoothly and by tight fitting, and the work steps can be reduced, and the connecting member 31 does not require high processing accuracy.

Embodiment 2. 4 is a sectional view of a connecting member 51 according to Embodiment 2 of the present invention.
Has a press-fitting portion 52 having a hole 59 press-fitted into the output shaft 8 by a tight fit, and a spline portion 53 which is spline-engaged with the input shaft, and has an hardness higher than that of the press-fitting portion 52. And a section 54. The connecting member 51 is integrally formed of a sintered metal material by the same procedure as in the first embodiment.

Embodiment 3. FIG. 5A is a cross-sectional view of a connecting member 61 according to the third embodiment of the present invention. This connecting member 61 has a press-fitting portion 62 having a hole 69 press-fitted into the output shaft 8 by a tight fit and a hardness of 62. An engaging portion 64 higher than the press-fitting portion 62 is provided. The engaging portion 64 formed at the end of the connecting member 61 is the groove portion 6 of the input shaft 63 shown in FIG.
5 is engaged. The connecting member 61 is integrally formed of a sintered metal material by the same procedure as in the first embodiment.

Fourth Embodiment FIG. 6A is a sectional view of a connecting member 71 according to the fourth embodiment of the present invention. The connecting member 71 has a press-fitting portion 72 having a hole 79 into which the output shaft 8 is press-fitted with an interference fit, and FIG. Input shaft 73 as shown in b)
And a mating portion 74 having a hardness higher than that of the press-fitting portion 72. The connecting member 71 is integrally formed of a sintered metal material by the same procedure as in the first embodiment.

Embodiment 5. 7 is a sectional view of a connecting member 81 according to a fifth embodiment of the present invention.
Is an engaging portion 84 having a spline hole 85 splined to a spline portion 89 of the output shaft 88, and an input shaft 83.
It has a hole 90 to be press-fitted by a tight fit and a press-fitting portion 82 having a hardness lower than that of the engaging portion 84. The connecting member 81 is integrally formed of a sintered metal material by the same procedure as in the first embodiment.

[0025]

As described above, according to the motor of the first aspect of the present invention, the cylindrical yoke, the output shaft rotatably provided on the central axis of the yoke, and the output thereof. An armature fixed to the shaft, and a connecting member for transmitting the rotational torque of the output shaft to the input shaft, the connecting member, the output shaft is press-fitted by interference fit,
The engagement part that is engaged with the input shaft and has a hardness higher than that of the press-fitting part is made of a sintered metal material having a high hardness after quenching and a hardened metal material after quenching.
Since it is integrally molded with a sintered metal material whose degree of increase does not increase so much , the number of parts and working steps are reduced, and the connecting member does not require high part accuracy.

According to the motor of the second aspect, a cylindrical yoke, an output shaft rotatably provided on the central axis of the yoke, an armature fixed to the output shaft, and A coupling member that transmits the rotational torque of the output shaft to the input shaft is provided, and the coupling member has a press-fitting portion into which the input shaft is press-fitted with an interference fit and a hardness that is engaged with the output shaft and has a hardness higher than that of the press-fitting portion. The engaging part has a high hardness after quenching.
Sintered metal material and its hardness does not increase so much after hardening
Since it is integrally molded with the metal material ,
The number of parts and the work process are reduced, and the connecting member does not require high part accuracy.

Further, according to the motor of the third aspect, since the press-fitting portion has the hole, the press-fitting portion of the connecting member is firmly coupled to the input shaft or the output shaft with a simple structure.

Further, according to the motor of the fourth aspect, since the engaging portion has the spline portion, the engaging portion of the connecting member is securely coupled to the input shaft or the output shaft with a simple structure. .

Further, according to the motor of the fifth aspect, since the engaging portion has the spline hole, the engaging portion of the connecting member is securely coupled to the input shaft or the output shaft with a simple structure. .

Further, according to the motor of the sixth aspect, since the engaging portion has the convex portion which engages with the groove portion formed at the end portion of the input shaft, the engaging portion of the connecting member is simple. With a simple structure, it is securely connected to the input shaft or output shaft.

Further, according to the motor of the seventh aspect, since the engaging portion has the groove portion which engages with the convex portion formed at the end portion of the input shaft, the engaging portion of the connecting member is simple. With a simple structure, it is securely connected to the input shaft or output shaft.

Further, according to the motor of the eighth aspect, since the input shaft is the shaft for the steering device for transmitting the rotational force to the steering wheel, the number of parts and working steps are reduced, and high part precision is not required. A motor for an electric power steering device having a connecting member can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a motor for an electric power steering device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

3 (a), (b) and (c) are explanatory views of a manufacturing procedure of the connecting member of FIG.

FIG. 4 is an enlarged cross-sectional view of a main part of a motor for an electric power steering device according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of essential parts of a motor for an electric power steering device according to a third embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view of essential parts of a motor for an electric power steering device according to a fourth embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view of essential parts of a motor for an electric power steering device according to a fifth embodiment of the present invention.

FIG. 8 is a perspective view showing a state in which a motor for a conventional electric power steering device is used.

9 is a cross-sectional view of the motor for the electric power steering device of FIG.

FIG. 10 is an enlarged view of a main part of FIG.

[Explanation of symbols]

4 yoke, 8 amateur, 23,83 input shaft, 2
4 handles, 30 motors, 31, 51, 61, 71,
81 connecting member, 32, 52, 62, 82 press-fitting portion, 3
3,85 Spline hole, 34, 54, 64, 74, 8
4 engaging parts, 39, 59, 69, 79, 90 holes, 5
3,89 Spline part, 65,79 groove part, 75 convex part.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Unexamined Patent Publication No. 10-86831 (JP, A) Japanese Unexamined Patent Publication No. 53-8456 (JP, A) Actual exploitation No. 56-15467 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) H02K 7/00 B62D 5/04 F16D 1/06

Claims (8)

(57) [Claims] 1. A cylindrical yoke, an output shaft rotatably provided on a central axis of the yoke, an armature fixed to the output shaft, and a rotational torque of the output shaft to an input shaft. A coupling member, in which the output shaft is press-fitted by press-fitting with an interference fit, and an engagement part that is engaged with the input shaft and has a hardness higher than that of the press-fitting part has a hardness after quenching. Sintered metal material with high firing
With a sintered metal material, the hardness of which does not increase so much after insertion
Motor configured are integrally molded Ri. 2. A cylindrical yoke, an output shaft rotatably provided on the central axis of the yoke, an armature fixed to the output shaft, and a rotational torque of the output shaft to an input shaft. And a coupling member, in which the input shaft is press-fitted by press-fitting the input shaft with an interference fit, and an engaging portion that is engaged with the output shaft and has a hardness higher than that of the press-fitting part, the hardness after quenching. Sintered metal material with high firing
With a sintered metal material, the hardness of which does not increase so much after insertion
Motor configured are integrally molded Ri. 3. The motor according to claim 1, wherein the press-fitting portion has a hole. 4. The motor according to claim 1, wherein the engaging portion has a spline portion. 5. The motor according to claim 1, wherein the engaging portion has a spline hole. 6. The motor according to claim 1, wherein the engaging portion has a convex portion that engages with a groove portion formed at an end portion of the input shaft. 7. The motor according to claim 1, wherein the engaging portion has a groove portion that engages with a convex portion formed at an end portion of the input shaft. 8. The motor according to claim 1, wherein the input shaft is a shaft for a steering device that transmits a rotational force to a steering wheel.