JP3146041B2 - Power steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power steering device for a vehicle, and more particularly to an improved potentiometer for detecting an initial rotation operation.

[0002]

2. Description of the Related Art The structure of a conventional power steering device will be described with reference to FIGS. First, there is a housing 1, which is composed of a case 3 and a case 5 attached to the case 3.
Above Haujinku 1, the stub shaft 7 have been inserted, this stub shaft 7, via a torsion bar 9, the pinion shaft 11 is connected. A steering handle 13 is connected to the stub shaft 7, as shown in FIG.

[0003] A cap 15 is mounted between the stub shaft 7 and the case 5.
A seal 17 and a bearing 19 are mounted between the stub shaft 7 and 5. Also, the pinion shaft 1
Bearings 21 and 23 are also mounted between 1 and case 3. A cap 2 is provided on the left end of the case 3 in FIG.
5 are attached.

The pinion shaft 11 has a pinion gear 2
The rack gear 31 formed on the rack shaft 29 meshes with the pinion gear 27. As shown in FIG. 7, wheels 35, 3 are connected to both ends of the rack shaft 29 via links 33, 33 '.
5 'are connected. The rack shaft 29 is urged toward the pinion shaft 11 by an adjustment cap 37, a pressure spring 39, and a pressure pad 41, as shown in FIG.
The backlash between the rack gear 31 and the pinion gear 27 is eliminated.

As shown in FIG. 9, three pins 43 are protruded from the outer periphery of the stub shaft 7.
A planet gear 45 is rotatably attached to the pin 43. These three planet gears 45 mesh with a sun gear 47 rotatably arranged on the inner peripheral side thereof. The three planet gears 45 also mesh with a ring gear 49 disposed on the outer peripheral side. Also, three pins 51 are provided on the pinion shaft 11 side.
And a planet gear 53 is rotatably attached to the three pins 51. The three planet gears 53 mesh with the sun gear 47 described above, and also mesh with a ring gear 55 fixed to the case 5 on the outer peripheral side. These gears constitute a gear group.

[0006] Stub shaft 7 and pinion shaft 11
Are connected in a relationship as shown in FIG. First,
The flange portion 57 of the stub shaft 7 has a pair of cutout portions 59, 59 'formed at 180 ° positions. on the other hand,
The flange portion 61 of the pinion shaft 11 has a 180 °
Is provided with a pair of projections 63, 63 '.
The stub shaft 7 and the pinion shaft 11 are connected by engaging the pair of protrusions 63 and 63 ′ with the pair of notches 59 and 59 ′. or,
In the above connection state, the projections 63, 63 'and the notches 59, 5
A gap is formed in the circumferential direction between the gap 9 ′. Within this gap, the stub shaft 7 and the pinion shaft 1
1 relative rotation is allowed.

A direct acting potentiometer 65 is provided on the outer peripheral side of the ring gear 49. That is, as shown in FIG.
, The plunger 69 is connected. The plunger 69 is arranged to slide inside the valve case 71 in the left-right direction in the figure. A potentiometer 73 is provided in the valve case 71, and the potentiometer 73 controls the rotation amount of the ring gear 49 and thus the relative rotation amount of the stub shaft 7 and the pinion shaft 11 through sliding of the plunger 69. To detect.

As shown in FIG. 7, an assist pinion 75 is engaged with the rack gear 31 of the rack shaft 29. This assist pinion 75 is
9 via a speed reducer 77. The drive motor 79 is controlled by the controller 81. The controller 81 is provided with the direct acting potentiometer 65.
From the vehicle and the signal from the vehicle speed sensor 83,
This is for controlling the drive motor 79.

In the above construction, when the direction in time to the rolling operation to be a steering wheel 13 to steer the vehicle, the stub shaft 7 to the rotation of the same amount. At that time, the pinion shaft 1
On one side, its rotation is limited by wheels 35 , 35 '
I have. Therefore, the torsion bar 9 is twisted by a predetermined amount
In the state, the pinion shaft 11 rotates the stub shaft 7
You will follow the roll . The rotation of the stub shaft 7 rotates the ring gear 49, whereby the direct acting potentiometer 65 detects the relative rotation amount between the stub shaft 7 and the pinion shaft 11 via the pin 43.

A signal from the direct acting potentiometer 65 is input to a controller 81. Controller 81
Is based on the signal and the signal from the vehicle speed sensor 83,
A control signal is output to the drive motor 79. Thereby,
The drive motor 79 rotates to rotate the assist pinion 75 via the speed reducer 77. Thereby, the power assisting force is applied to the rack shaft 11 via the rack gear 31. Accordingly, the rack shaft 11 moves by a predetermined amount in an appropriate direction, and steers the wheels 35 and 35 '. The movement is fed back to the steering wheel 13 via the rack gear 31, the pinion gear 27, the pinion shaft 11, and the stub shaft 7.

[0011]

According to the above-mentioned conventional configuration, there are the following problems. First, while the ring gear 49 for transmitting the rotational operation of the stub shaft 7 makes a rotational movement, the direct acting potentiometer 65 for detecting this rotational movement.
Is a linear motion, so that the controller 8
1, a conversion circuit for converting a signal indicating the linear motion of the linear motion potentiometer 65 into a rotation angle is required, and the configuration of the controller 81 is complicated.

Further, there is a problem that the sliding resistance between the plunger 69 and the valve case 71 in the direct acting potentiometer 65 appears as hysteresis, and the control accuracy is reduced due to the hysteresis. Further, since the direct-acting potentiometer 65 is disposed so as to protrude on the outer peripheral side of the ring gear 49, interference with other devices becomes a problem, and the degree of freedom of layout of other devices is reduced. There was a problem that it would.

The present invention has been made on the basis of the above points, and it is an object of the present invention to provide a power steering apparatus capable of simplifying the configuration, improving control accuracy, and reducing the size of the apparatus. It is in.

[0014]

In order to achieve the above object, a power steering apparatus according to the present invention rotates a steering handle to rotate a stub shaft connected to the steering handle by an arbitrary amount in an arbitrary direction. Connected to the stub shaft and torsion bar
The combined relative rotation amount with respect to the pinion shaft is detected by a potentiometer via a gear group arranged on the outer peripheral side of the stub shaft and the pinion shaft , and a predetermined power assist force is exerted based on a detection signal of the potentiometer. It is assumed that the power steering device configured as described above is used. Assuming the above equipment,
The gear group is the stub shaft and pinion shaft
A planet that is rotatably mounted on a shaft fixed to the outer periphery
Gear and the inner circumference of this planet gear
Arrange the sun that meshes with each of the planet gears
Gear and planet gear on the stub shaft side
Fit and rotate around the outer circumference of the planet gear
Place the ring gear and the pinion shaft side
Mesh with the net gear and outside the planet gear
The ring gear is fixed to the peripheral case.
Rotary potentiometer on the ring gear on the shaft side
Of the stub shaft and the pinion shaft by the rotary potentiometer via the gear group.
The amount of relative rotation with respect to the angle is detected .

[0015]

The initial rotation of the stub shaft by the steering wheel is detected by a rotary potentiometer via a group of gears. In the rotary potentiometer, the rotating portion rotates in synchronization with the rotation of the gear group, and the detection signal indicates the amount of rotation. Therefore, it is particularly complicated to calculate the rotation angle of the stub shaft. There is no need for a simple conversion circuit. Further, since there is no sliding portion that generates a large sliding resistance unlike a direct acting potentiometer, there is no occurrence of hysteresis caused by the sliding resistance. Further, since the potesinometer of the present invention is coaxially arranged on the outer peripheral side of the stub shaft, it does not greatly protrude to the outer peripheral side of the gear group unlike the related art.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will now be described with reference to FIGS.
An embodiment will be described. The same parts as those in the related art are denoted by the same reference numerals and description thereof is omitted. First,
On the outer peripheral side of the case 15, a rotary potentiometer 10
1 is installed. This rotary potentiometer 10
1 has a configuration as shown in FIG. First, there is a cylindrical shaft 103, and an outer case 105 and an inner case 107 are arranged on the outer and inner circumferential sides of the cylindrical shaft 103, respectively.

A rotor 109 is provided between the outer case 105 and the cylindrical shaft 103, and a brush 111 is attached to the rotor 109.
A resistor 113 is disposed on the right side of the brush 111 in the drawing, and the resistor 113 is held by a cover 115. The cover 115 and the outer case 10
5 and the inner case 107, a sealant 11
7 are filled. O-rings 119 and 121 are provided between the outer case 105 and the cylindrical shaft 103 and between the inner case 107 and the cylindrical shaft 103.
Is installed. The structure between the outer case 105 and the inner case 107 is shown in an exploded perspective view of FIG. Incidentally, reference numerals 141 and 143 in FIG. 2 denote bearings.

On the left side of the cylindrical shaft 103 in the figure,
The lever 123 is fixed by caulking, and a pin 125 is fixed to the lever 123 on the side opposite to the cylindrical shaft 103 by spot welding. The above pin 125
Are connected to a ring gear 49. FIG. 3 shows the connection structure. First, an annular groove 127 is formed in the pin 125. The pin 125 is fixed to the ring gear 49 via the adjuster 129.

The adjuster 129 is formed by making a plate into a ring shape, and has a projection 131 projecting from the outer periphery thereof and another projection 133 projecting from the inner periphery thereof. The adjuster 129 is connected to the pin 12
5 is fitted to the outer peripheral side of the
5 is engaged with the annular groove 127. Thereby, the play between the adjuster 129 and the pin 125 is eliminated. The adjuster 129 is fitted into the fitting recess 135 of the ring gear 49 in a state where the adjuster 129 is fitted on the outer peripheral side of the pin 125. A groove 137 is formed in the fitting recess 135, and the projection 131 of the adjuster 129 is engaged with the groove 137. Thereby, the play between the adjuster 129 and the ring gear 49 is eliminated. In the rotary potentiometer 101 according to the present embodiment, the rotating portion includes a pin 125, a lever 123, a cylindrical shaft 103,
This is a portion composed of the rotor 109 and the brush 111.

The operation will be described based on the above configuration.
The basic operation of the power steering device is the same as that of the conventional power steering device, and will not be described. By the initial rotation operation of the steering wheel 13 (shown in FIG. 7), the ring gear 49 rotates through the stub shaft 7 in an arbitrary direction by an arbitrary amount. The rotation of the ring gear 49 causes the rotor 10 to move through the pin 125, the lever 123, and the cylindrical shaft 103.
9 rotates. The rotation of the rotor 109 causes the brush 111 to rotate.
Also rotates, whereby the resistance value of the resistor 113 changes. Then, a signal indicating a change in the resistance value is output to the controller 81 (shown in FIG. 7). Controller 81
Controls the drive motor 79 (shown in FIG. 7) based on the signal and the signal from the vehicle speed sensor 83 (shown in FIG. 7) to exert a predetermined power assisting force.

According to this embodiment, the following effects can be obtained. First, the configuration of the controller 81 was simplified and the control accuracy was improved. This is because the rotary potentiometer 101 was used in place of the conventional linear potentiometer. That is, the use of the rotary potentiometer 101 eliminates the need for a conversion circuit for calculating a rotation angle from a signal indicating a linear motion, which has been conventionally required. Further, since there is no sliding portion between the ring gear 49 and the rotary potentiometer 101 as in the related art, there is no hysteresis due to sliding resistance, thereby improving control accuracy.

Further, by employing the rotary potentiometer 101, there is no longer a protruding portion on the outer peripheral side of the ring gear 49 as in the prior art. Has been greatly expanded.

Next, a second embodiment of the present invention will be described with reference to FIG. In the case of this embodiment, the pin 125, the lever 123, and the cylindrical shaft 103 of the first embodiment are used.
Is formed by integral molding with resin, and the shaft member 2 is formed.
01. In this case, the same effects as those of the first embodiment can be obtained, and in addition, there is an advantage that manufacturing and assembling become easy because the number of parts is reduced.

The present invention is not limited to the above embodiments. For example, the rotary potentiometer is not limited to a contact-type potentiometer as shown in each of the above embodiments, but may be a non-contact-type using an MR element or the like.

[0025]

As described above in detail, according to the power steering apparatus of the present invention, since the rotation of the stub shaft by the steering wheel is detected by the rotary potentiometer via the gear group, the rotation angle of the stub shaft is determined. Since a particularly complicated conversion circuit is not required for the calculation, the configuration can be simplified. or,
Since there is no sliding portion that generates a large sliding resistance unlike a direct acting potentiometer, there is no occurrence of hysteresis due to the sliding resistance, and control accuracy can be improved. The rotary potometer is arranged coaxially on the outer circumference of the stub shaft, so that it does not protrude greatly to the outer circumference of the gear group unlike conventional products, and there is little interference with other equipment. Therefore, the degree of freedom in layout of other devices is expanded.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention, and is a cross-sectional view showing a partial configuration of a power steering device.

FIG. 2 is a view showing the first embodiment of the present invention, and is a cross-sectional view showing the configuration of the rotary potentiometer.

FIG. 3 is a view showing the first embodiment of the present invention, and is an exploded perspective view showing a configuration of mounting a rotary potentiometer.

FIG. 4 is a diagram showing the first embodiment of the present invention, and is an exploded perspective view showing a partial configuration of the rotary potentiometer.

FIG. 5 is a view showing a second embodiment of the present invention, and is a cross-sectional view showing a configuration of a rotary potentiometer.

FIG. 6 is a diagram showing a conventional example, and is a cross-sectional view showing a partial configuration of a power steering device.

FIG. 7 is a diagram illustrating a conventional example, and is a diagram illustrating an entire configuration of a power steering device.

FIG. 8 is a view showing a conventional example, and is a view showing a configuration of a direct acting potentiometer.

FIG. 9 is an exploded perspective view showing a configuration of a part of a power steering device in a diagram showing a conventional example.

[Explanation of symbols]

 7 stub shaft 13 steering handle 49 ring gear (part of gear group) 101 rotary potentiometer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62D 5/04-5/06

Claims (1)

(57) [Claims] 1. A stub shaft connected to a steering wheel is rotated by an arbitrary amount in an arbitrary direction by rotating the steering wheel to rotate the stub shaft and the stub shaft.
Phase with the pinion shaft connected via the option bar
Set the amount of rotation against the stub shaft and pinion shaft
In a power steering device configured to detect with a potentiometer via a gear group arranged on the outer peripheral side of the motor and exert a predetermined power assist force based on a detection signal of the potentiometer, the gear group includes
On the outer circumference of the tab shaft and pinion shaft respectively
A planet gear rotatably mounted on a fixed shaft,
If it is arranged rotatably on the inner peripheral side of this planet gear,
The sun gear that meshes with each of the planet gears
Engage with planet gears on the stub shaft side
A ring rotatably arranged on the outer peripheral side of the planet gear
Gear and the planet gear on the pinion shaft side
Meshes with the outer case of the planet gear.
It consists of a fixed ring gear and the stub shaft side
To the rotating part of the rotary potentiometer
Combined, the relative times of the stub shaft and the pinion shaft via the gear train by the rotary potentiometer
A power steering device characterized by detecting a shift amount .