JPH0427663A - Reduction gear for electric power steering - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electric power steering device that uses an electric motor to directly assist the driver in steering power, and is particularly suitable for electric power steering when it is necessary to increase the torque of the electric motor. This invention relates to a reduction gear for use.

[Conventional technology]

Conventional reduction gears for electric power steering are disclosed in Japanese Patent Application Laid-open No. 1-
As described in No. 115771, the gear was fixed to the rotating body and had a structure that it could not be moved.

[Problem to be solved by the invention] In the conventional electric power steering reduction gear device described above,
No consideration has been given to reducing the bank crush of the reducer, which consists of a hypoid gear and a hypoid pinion, and when the steering wheel is turned left or right, there is a problem in that tooth contact and rattling noises due to the bank crush of the gears occur.

An object of the present invention is to solve the above-mentioned problems by providing a spring that pushes up the hypoid gear between the hypoid gear and the lower rotating body to which the hypoid gear is attached. An object of the present invention is to provide a reduction gear for electric power steering that reduces rattling noise caused by gear tooth contact.

[Means to solve the problem]

The above purpose is to provide an upper rotating body that rotates in response to rotation of a steering wheel, a lower rotating body that is connected to the upper rotating body via a torsion bar, and that rotates while generating a torsion angle according to lateral torque, and a lower rotating body that rotates while generating a torsion angle according to lateral torque. An angle signal and torque signal generator attached to each of the body and the lower rotating body to detect the rotation angle and torque, and an outer box for detecting the rotation angle and torque in combination with the angle signal and torque signal generator. A speed reduction device for electric power steering comprising an angle signal and torque signal detecting body fixed to the body and a speed reducer for transmitting driving force attached to the lower rotary body,
This is achieved by inserting a spring into the outer periphery of the screw that attaches the hypoid gear of the reducer to the lower rotating body.

[Effect]

An electric power steering system uses a torque signal detector to detect the torsional torque generated on the steering wheel when the driver applies steering force, and applies a predetermined assist force to the electric motor, clutch, and reduction gear according to the detected value. This is a device that assists the driver's steering force by controlling the control device so that it occurs through the steering force.

Here, a spring is inserted into the outer part under the neck of the screw that attaches the hypoid gear to the lower rotating body. Since the hypoid gear is pushed up by this spring force and meshes with the hypoid pinion, backlash between the hypoid gear and the hypoid pinion can always be eliminated.

Methods for eliminating backlash in the reducer include not only the method of pushing up the hypoid gear as described above, but also a method of moving the hypoid pinion. This is possible by providing a spring that presses the outer ring of the bearing supporting the hypoid pinion via a bow-shaped member.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. An involute spline 2 is cut at the tip of the pinion shaft 1a of the hypoid pinion 1, and meshes with an involute spline 4 of the clutch 3. or,
An angular bearing 5 is press-fitted into the rear end shaft 1b of the hypoid pinion 1, and is tightened with a nut 7 through a washer 6.

Here, the hypoid pinion 1 has a leading end supported by a bearing 9 press-fitted into an outer case 8, and a rear end supported by the angular bearing 5. The axial position of the hypoid pinion 1 is adjusted by a washer 10 inserted into the end of the angular bearing 5, and fixed by tightening a threaded pinion cover 11.

The hypoid pinion 1 meshes with a hypoid gear 12, and constitutes a reduction gear 12a. The torque of the electric motor 13 is reduced by this reduction gear 12a, and the torque is increased.

The hypoid gear 12 is inserted into the screw hole IS of the lower rotating body 14.
After inserting the spring 17 into the counterbore hole 16 of the section, it is inserted into the lower rotating body 14 and tightened to the lower rotating body 14 with a screw 18.

FIG. 2 is a partially enlarged view showing details of the screw 18 portion. As shown in FIG. 2, the hypoid gear 12 is capable of moving in the axial direction of the rotating body 14 by the total amount of gaps 1 and 2, and is pushed upward by a spring 17, so that it is free from backlash. It meshes with the hypoid pinion 1. In addition to a coil spring, a wave washer, a bending washer, etc. can be used as the spring 17.

In FIG. 1, the lower rotating body 14 is connected to a torsion bar 19 and a pin 20. As shown in FIG.

Further, the torsion bar 19 is connected to an upper rotating body 22 by a pin 21 at the upper part.

Here, an angle signal and torque signal generator 23 and a bearing 24 are press-fitted into the lower rotating body 14.

Meanwhile, a torque signal generator 25, a bearing 26, and a bearing 27 are press-fitted into the upper rotating body 22.

As described above, via the torsion bar 19, the bottle 20. The upper rotating body 22 and the lower rotating body 14, which are connected by a pin 21, are supported by the outer case 8 through a bearing 26 at the upper side, and supported by a bearing 29 press-fitted into the outer case 28 at the lower side.

Further, the angle signal and torque signal detector 30 installed parallel to the angle signal and torque signal generator 23 and the torque signal generator 25 is adhesively fixed to the slider 32a via an alumina substrate 31, Further, the slider 32a, together with the sliders 32b and 32c, is screwed to a holder 33, and the holder 33 is fastened to the outer box 8 with screws 34, and is protected from the outside by a sensor cover 35. There is. Further, the angle signal and torque signal generator 23, the torque signal generator 25. A control device 37 that controls the electric motor 13 according to output signals of a torque sensor 36 consisting of an angle signal and a torque signal detector 30 is attached to the outer box 8 .

FIG. 3 is a partial sectional view of FIG. 1 taken along the axial center of the Hybonion and viewed from above. As shown in FIG. 3, the hypoid gear 12 is fastened to the lower rotating body 14 with six screws 18.

FIG. 4 is a partial vertical cross-sectional view of a portion of a hypoid binion showing an alternative plan for eliminating the eight-stroke of the speed reducer. By pressing the outer ring of the angular bearing 5 supporting the hypoid pinion 1 with a coned disc spring 39 via a bow-shaped member 38, the hypoid gear 1 is
Can be combined with 2.

FIG. 5 is an overall configuration diagram of the electric power steering. Steering wheel 4 connected to upper rotating body 22
When the driver operates 0, the 1-1 rotation bar is twisted, and the angle signal and torque signal detector 30 of the torque sensor 36 outputs an angle signal and torque signal generator 23 from the rotation angle difference between the upper rotating body 22 and the lower rotating body 14. ．． Torque signal generator 25
The torsional torque is detected and transmitted to the control device 37 via.

As a result, the control device 37 applies a predetermined assist force to the electric motor according to the value detected by the torque sensor 36.
3, the electric motor 13 is supplied with electric power from the battery 41, and the torque generated by the electric motor 13 is generated by the clutch 3.
Hypoid binion via 1. The drive pinion 4 is increased by a reducer 12a consisting of a hypoid gear 12, and is connected to the drive pinion 4 from the lower rotating body 14 via a universal joint 42.
3, the rack 44 is moved with the help of the operating force of the steering wheel 40, and the direction of the tires 45 is changed.

According to this embodiment, the spring 17 causes the hypoid gear 1 to
Since the pinion 2 can be pushed up and meshed with the hypoid pinion 1 without bumping, there is an effect that tooth contact noise and rattling noise due to bumping can be prevented when the steering wheel 40 is turned left and right.

〔Effect of the invention〕

According to the present invention, the hypoid gear is pushed up by the spring force of the spring provided between the hypoid gear and the lower rotary body, and can be brought into a state where there is no collision with the hypoid pinion, as described below. You can get a great effect.

When the driver turns the steering wheel left or right, there is no bank crash of the reducer, so the noise of gear teeth hitting can be reduced, making it possible to reduce the noise of the reducer.

Furthermore, according to the backlash prevention method of the present invention, since only the hypoid gear is moved, the angle signal and torque signal generator press-fitted into the lower rotating body, the torque signal generating body press-fitted into the upper rotating body, and the outer box It is possible to reduce positional deviation between the sensor and the angle signal and 1-lux signal detector fixed via a holder, slider, etc., thereby reducing torque detection errors caused by positional deviation and improving the accuracy of the torque sensor. effective.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, including an electric motor, a clutch,
A vertical cross-sectional view of the reducer and torque sensor. Figure 2 is a partially enlarged vertical cross-sectional view of the hypoid gear shown in Figure 1 screwed to the lower rotating body via a spring. Figure 3 is a cross-sectional view taken along I-I in Figure 1. 4 is a partial vertical sectional view of the hypoid pinion portion showing an alternative of the present invention to eliminate backlash of the reducer; FIG. 5 is a line sectional view;
The figure is an overall configuration diagram showing the entire configuration of electric power steering. 8...Outer box, 12a...Reducer, 14...Lower rotating body, 17...Spring, 19...Torsion bar 2
2... Upper rotating body, 23... Angle signal and torque signal generator, 25... Torque signal generator, 30... Angle signal and torque signal detector, 40... Steering wheel. Rod concave potato beef Sendai

Claims (1)

[Claims] 1. An upper rotating body that rotates in response to the rotation of the steering wheel; a lower rotating body that is connected to the upper rotating body via a torsion bar and rotates while producing a torsion angle according to the steering torque; and the upper rotating body. An angle signal and torque signal generator attached to each of the lower rotating bodies to detect the rotation angle and torque, and fixed to the outer box in combination with the angle signal and torque signal generator to detect the rotation angle and torque. In the electric power steering reduction device, the reduction gear includes a reduced angle signal and torque signal detector, and a reducer attached to the lower rotary body for transmitting driving force, wherein a gear is provided between the gear of the reducer and the lower rotary body. A reduction gear for electric power steering characterized by being equipped with a push-up spring.