JP2003307419A - Rudder angle detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rudder angle detector capable of detecting rotation angle of a shaft rotating a plurality of times around a shaft according to the operation of a steering means in whole rotatable range with a simple constitution without requiring a complex operational processing and detecting an absolute rudder angle accurately. <P>SOLUTION: Rotation of a column shaft S inside a housing H is decelerated with a small gear 16 and a large gear 15 to transmit to a rotation shaft 12 and a rotating disk 13 fitted with the rotation shaft 12 is rotated within one turn. On the rotation circumference of the rotating disk 13, a plurality of targets 17, 17... forming a slit hole are lined. With an optical sensor 14 provided with a luminous part 14a and a reception part 14b facing on the two sides of the forming range of the targets 17, 17..., the displacements of the targets 17, 17... are detected. By using the detection results, the rotation angle of the column shaft S is obtained and the absolute rudder angle is operated. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering angle detecting device for detecting a rotation angle of a shaft that rotates in response to an operation of steering means such as a steering wheel.

[0002]

2. Description of the Related Art An electric power steering apparatus for driving a steering assisting motor in response to an operation of a steering means (steering wheel or the like) for steering and transmitting the rotational force of the motor to a steering mechanism to assist steering. Has an advantage over the hydraulic power steering device that uses a hydraulic actuator as a source of the steering assist force that the assist force characteristics such as vehicle speed and steering frequency can be easily controlled according to the traveling state. Therefore, in recent years, its application range tends to expand.

In such an electric power steering apparatus, it is necessary to detect the steering torque applied to the steering wheel in order to use it for driving control of a motor for steering assistance, and also to use it for driving control of the motor. It is necessary to detect the steering angle (steering angle) performed according to the operation of the steering wheel. The rudder angle detector that detects the rudder angle uses a rotation angle detector such as a potentiometer or rotary encoder to rotate the column shaft that connects the steering wheel to the steering mechanism and the shaft such as the pinion shaft in the steering mechanism. It has been put to practical use by a configuration that detects an angle.

[0004]

However, while most of the rotation angle detectors are configured to detect the rotation angle within one rotation, the rotation operation of the steering wheel is performed during straight running. Generally, the rotation is performed in a range of 2 to 3 rotations on each of the left and right sides around the neutral position. In order to obtain the absolute steering angle from the neutral position, the detection values of the rotation angle detector are sequentially integrated. There is a need.

Further, since the steering wheel operation during traveling is performed randomly in both left and right directions, it is necessary to determine the change of the operation direction in order to obtain the absolute steering angle. In order to eliminate the accumulation of errors and obtain a highly accurate steering angle detection value, it is necessary to perform 0-point correction during straight running in the neutral state, including the above-described integration, determination, and correction processes. There is a problem in that the calculation processing becomes complicated and the product cost increases.

The detection of the steering angle as described above may be necessary not only in the electric power steering device but also in a vehicle equipped with a hydraulic power steering device, and a steering device having no steering assist means may be used. Even the equipped vehicle may be required to be used for other control of each part of the vehicle such as traction control, ABS control, suspension control, and the like.

The present invention has been made in view of the above circumstances, and detects the absolute steering angle as the rotation angle of a column shaft, a pinion shaft, or the like that rotates a plurality of times to the left or right in response to the operation of the steering means. It is an object of the present invention to provide a rudder angle detecting device capable of detecting with high accuracy with a simple configuration without requiring complicated calculation processing.

[0008]

A rudder angle detecting device according to a first aspect of the present invention is arranged in the middle of a shaft which rotates a plurality of times around an axis in response to an operation of the steering means, and the rotation of the shaft. In a rudder angle detecting device for detecting an angle, a rotating body that rotates within one rotation by transmission from the shaft and a rotating body of the rotating body are arranged side by side, and a position in the circumferential direction according to the rotation. It is characterized by comprising a plurality of changing targets and a detection means for detecting the displacement of the target at a predetermined position on the rotation circumference.

In the present invention, the rotation of the shaft (column shaft, pinion shaft, etc.) that rotates left and right a plurality of times in response to the operation of the steering means is transmitted to the rotating body by deceleration, and the rotating body rotates within one rotation. Then, the displacement of the plurality of targets in the circumferential direction, which occurs on an appropriate rotation circumference at this time, is detected by the detection means, and the rotation angle of the shaft is obtained based on the detection result. The target and the detection means are, for example, a combination of a plurality of slits provided in the rotating body and an optical sensor including a light emitting unit and a light receiving unit that are arranged to face each other across the formation region of these slits, or the rotating body. It can be configured by a combination of a plurality of magnetic protrusions provided and an MR (magnetoresistive effect) sensor facing the arrangement region of these magnetic protrusions.

A rudder angle detecting device according to a second aspect of the present invention is arranged in the middle of a shaft that rotates a plurality of times around the shaft in response to the operation of the steering means, and the rudder angle detecting device detects the rotation angle of the shaft. In the angle detection device, a rotating body that rotates within one rotation by transmission from the shaft, a displacement portion that is provided in a part of the rotating body, and that changes in position in the radial direction according to the rotation, and the displacement. And a detection unit that detects displacement of the section.

In the present invention, the rotation of the shaft (column shaft, pinion shaft, etc.) that rotates left and right a plurality of times in response to the operation of the steering means is transmitted to the rotating body by deceleration, and the rotating body rotates within one rotation. Then, the radial displacement generated in the displacement portion provided in a part of the rotating body at this time is detected by the detecting means, and the rotation angle of the shaft is obtained based on the detection result. The displacement portion can be configured, for example, as a cam surface that continuously expands the outer peripheral portion of the rotating body in the circumferential direction, and the detection means displaces the detection rod whose tip is brought into contact with the cam surface. Can be configured as a means for detecting.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. FIG. 1 is a side sectional view showing a first embodiment of a rudder angle detecting device according to the present invention. The rudder angle detecting device 1 shown in this drawing is of a column shaft S supported inside a housing H. It is configured as follows to detect the rotation angle.

The column shaft S has a pair of bearings B ₁ and B arranged inside the housing H and separated from each other in the axial direction.
_A steering wheel (not shown) as a steering means is fitted and fixed to one end of a column shaft S which is rotatably supported around the shaft via a shaft ₂ and protrudes to one side of the housing H. The other end of the column shaft S protruding to the other side of H is connected to a steering mechanism (not shown).

With the above construction, the column shaft S rotates around its axis in response to the rotating operation of the steering wheel for steering at one end, and this rotation is connected to the other end. The steering is performed by a known operation of the steering mechanism according to the rotation transmission. At this time, the steering wheel is operated to rotate in the range of 2 to 3 rotations on the left and right sides centering on the neutral position during straight traveling, so that the steering angle detection device 1
Has a configuration capable of detecting the rotation angle of the column shaft S occurring in the range of 4 to 6 rotations.

The rudder angle detecting device 1 shown in FIG.
A rotary shaft 12 rotatably supported inside the housing H so as to be parallel to one side thereof, and a rotary disk (rotary body) 13 coaxially fitted and fixed to a middle portion of the rotary shaft 12. The rotating disk
An optical sensor 14 fixed to the housing H is provided so that 13 is to be detected.

The rotary shaft 12 has a large gear 15 coaxially fitted to one side of the rotary disc 13. This gear
Reference numeral 15 is meshed with a small gear 16 provided at a corresponding position of the column shaft S, and the rotation of the column shaft S is transmitted to the rotating disk 13 by deceleration transmission from the small gear 16 to the large gear 15, The rotating disk 13 is adapted to rotate within one rotation.

FIG. 2 is a perspective view of a rotary disk 13 as a rotary body. The rotary disk 13 has a plurality of targets 17, 17 ... In the form of slit holes penetrating the rotary disk 13 on the front and back sides.
They are arranged side by side at regular intervals on an appropriate circumference of rotation. As shown in FIG. 1, the optical sensor 14 includes a light emitting portion 14a and a light receiving portion which are arranged to face each other so as to sandwich the rotating disc 13 from both sides in the thickness direction on the rotating circumference of the targets 17, 17 ... The target 17 is provided with 14b, and the light emitted from the light emitting section 14a is displaced in the circumferential direction by the rotation of the rotating disk 13.
Each time 17 ... Passes, it reaches the light receiving portion 14b, and the light receiving portion 14b emits a light receiving output.

The output of the optical sensor 14 associated with the reception of light by the light receiving section 14b is given to the steering angle calculation section A. In the steering angle calculation unit A, the output of the optical sensor 14 is counted, the rotation angle of the rotating disk 13 is obtained based on the integrated result of the count values, and the rotation angle of the column shaft S is calculated using this rotation angle. That is, the steering angle is calculated. Here, since the rotation of the rotating disk 13 is limited to one rotation or less in the entire rotation range of the column shaft S by the reduction transmission between the small gear 16 and the large gear 15, the steering angle calculation is performed. In the section A, the absolute rotation angle of the rotating disk 13 can be obtained, and the rotation angle of the column shaft S calculated using this result becomes the absolute angle in the rotatable range of the column shaft S, and The absolute steering angle can be detected over the entire operating range of the wheel.

FIG. 3 shows a second embodiment of the rudder angle detecting device according to the present invention.
FIG. 2 is a side sectional view showing the embodiment of the present invention, in which the steering angle detection device 2 shown in the drawing has a rotating body that rotates within one rotation due to transmission from the column shaft S, and a sensor that detects this rotating body. Except for this, the configuration is similar to that of the first embodiment shown in FIG. 1, and the corresponding parts are designated by the same reference numerals and the description thereof is omitted.

In this rudder angle detecting device 2, the rotating body is a rotating shaft supported in parallel to one side of the column shaft S.
The detection gear 20 is made of a magnetic material and is coaxially fitted in the middle of 12 and has a large number of teeth (magnetic protrusions) on the outer peripheral surface. The detection gear 20 is provided between the small gear 16 and the large gear 15. The deceleration transmission of 1 causes rotation within one rotation in the entire rotation range of the column shaft S.

The sensor whose detection target is the detection gear 20 is composed of an MR sensor 21 fixed to the housing H so as to face the outer peripheral surface (tooth surface) thereof. The MR
The sensor 21 incorporates a pair of magnetoresistive effect elements having a characteristic that electric resistance is changed by the action of a peripheral magnetic field, and a bias magnet which gives an even magnetic field to these elements, and the magnetoresistive effect element and two fixed elements are provided. An output voltage of a bridge circuit formed by connecting a resistor and a resistor in parallel is given to the steering angle calculation unit A.

The output of the MR sensor 21 as described above is periodically changed each time the teeth arranged in parallel on the outer circumference are displaced in the circumferential direction by the rotation of the detection gear 20 and pass through the facing position of the MR sensor 21. Output. In the steering angle calculation unit A, the rotation angle of the detection gear 20 is obtained based on the output of the MR sensor 21 as described above, and the rotation angle of the column shaft S, that is, the steering angle is calculated using this rotation angle. Be seen. Where the detection gear
Since the rotation of 20 is limited to one rotation or less in the entire rotation range of the column shaft S by the reduction transmission between the small gear 16 and the large gear 15, in the steering angle calculation unit A, the detection gear is The absolute rotation angle of 20 can be obtained, and the rotation angle of the column axis S calculated using this result is
The absolute steering angle can be detected over the entire operating range of the steering wheel.

In this embodiment, the detection gear 20 to be detected is provided independently, but the deceleration large gear 15 can also be used as the detection gear.
Further, in this embodiment, the detection gear 20 made of a magnetic material is used as the rotating body, and the MR sensor 21 including the bias magnet is provided to detect the detection gear 20. A disk formed by arranging the above magnets in parallel may be used as a rotating body, and the displacement of the magnet due to the rotation of the rotating body may be detected by an MR sensor that does not include a bias magnet.

FIG. 4 shows a third steering angle detecting device according to the present invention.
FIG. 3 is a side sectional view showing an embodiment of the present invention, in which the steering angle detection device 3 shown includes a rotating body that rotates within one rotation due to transmission from the column shaft S, and a sensor that detects this rotating body. Except for this, the configuration is similar to that of the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 2, and corresponding parts are designated by the same reference numerals and description thereof is omitted. .

In the rudder angle detecting device 3, the rotating body is a rotating shaft supported in parallel with one side of the column shaft S.
The cam plate 30 is fitted in the middle of 12. FIG. 5 is a perspective view of the cam plate 30 as a rotating body.
A cam surface 31 that continuously increases in diameter toward one side in the circumferential direction is provided on the outer circumference of the, and a displacement portion that changes its position in the radial direction according to the rotation of the cam plate 30 is configured.

The displacement sensor 32 shown in the figure, which detects the cam plate 30, is a dial gauge capable of electrical output, and is fixed to the housing H so as to be aligned with the mounting position of the cam plate 30. A detection rod 33 protruding inside H and having its tip abutted against the cam surface 31 is provided, and the displacement of the detection rod 33 in the axial direction is detected by the detection means inside the displacement sensor 32 and corresponds to the displacement amount. The steering angle calculation unit A is provided with this output.

The contact position of the detection rod 33 with the cam surface 31 is set at the midpoint between the maximum diameter portion and the minimum diameter portion of the cam surface 31 at the midpoint of the steering angle, as indicated by point X in FIG. The displacement sensor 32 is adapted to generate an output that continuously increases or decreases while the cam plate 30 makes a half rotation in both directions. The displacement sensor 32 is not limited to the configuration shown in the figure, and may be a sensor that detects the radial displacement of the cam surface 31 in a non-contact manner using light, ultrasonic waves, or the like.

In the steering angle calculation unit A, the rotation angle of the cam plate 30 is obtained based on the output of the displacement sensor 32 as described above, and this rotation angle is used to determine the rotation angle of the column shaft S, that is, the steering angle. Calculation is performed. Here, the rotation of the cam plate 30 is
Due to the deceleration transmission between the small gear 16 and the large gear 15, the rotation angle of the cam plate 30 in the steering angle calculation unit A is limited to one rotation or less in the entire rotation range of the column shaft S. The rotation angle of the column shaft S that can be obtained and calculated using this result is the absolute angle in the rotatable range of the column shaft S, and the absolute steering angle is detected over the entire operating range of the steering wheel. be able to.

FIG. 6 shows a fourth steering angle detecting device according to the present invention.
FIG. 4 is a side sectional view showing the embodiment of the present invention, in which the illustrated steering angle detecting device 4 is supported on both sides by bearings B ₁ and B ₂ inside the housing H as in the first to third embodiments. In order to detect the rotation angle of the column shaft S, it is constructed as follows.

As described above, the column shaft S rotates about its axis a plurality of times in response to the rotating operation of the steering wheel (not shown) attached to one end portion, and this rotation is applied to the steering wheel connected to the other end portion. It has the effect of transmitting it to the steering mechanism and causing it to perform steering. The rudder angle detecting device 4 for detecting the rotation of the column shaft S has a thread groove 40 having a semicircular cross section formed on the outer periphery of the middle portion of the column shaft S, and a large number of balls 41, 41
A ball nut (displacement body) 42 screwed through 41 ..., And a displacement sensor 43 fixed to the housing H so that the ball nut 42 can be detected.

The ball nut 42 engages a guide pin 44 projecting at one place on the outer peripheral surface with a guide groove 45 extending in the axial direction of the column shaft S on the inner surface of the housing H, and The rotation around is restricted. This allows the ball nut
When the column shaft S rotates, 42 is screwed along with the rolling of the balls 41, 41 ... Within the thread groove 40, and the guide groove 45 engaged with the guide pin 44 guides the guide groove 45. Of the column shaft S, that is, in the axial direction of the column shaft S. Since the direction of this displacement corresponds to the direction of rotation of the column shaft S, and the amount of displacement corresponds to the rotation angle of the column shaft S, the axial displacement of the ball nut 42 as a displacement body is detected. Thus, the rotation angle of the column shaft S can be obtained.

The displacement sensor 43 is a ball nut as described above.
It is attached to the housing H so as to face the outer surface of 42. As the displacement sensor 43, for example, as in the second embodiment shown in FIG. 3, an MR sensor having a built-in magnetoresistive effect element can be used, and the outer surface of the ball nut 42 facing the inner side of the MR sensor is described above. The magnetic target 46 is formed by providing a plurality of magnetized portions arranged at regular intervals within the stroke of axial displacement generated as described above. The magnetic target 46 may be formed by directly magnetizing the outer surface of the ball nut 42, or may be formed by attaching a tape containing magnetic powder to the outer surface of the ball nut 42.

With the above construction, when the column shaft S rotates, the ball nut 42 as a displacement body is displaced in the axial direction, and the displacement sensor 43 moves the magnetic target 46 in accordance with the displacement of the ball nut 42. In response, the magnetic target 46 emits an output that periodically changes each time the magnetized portion of the magnetic target 46 passes. This output is given to the steering angle calculation unit A,
In the rudder angle calculation unit A, the displacement amount (including the direction) of the ball nut 42 is obtained based on the output of the displacement sensor 43 as described above, and the displacement angle is used to determine the rotation angle of the column shaft S, that is, The steering angle is calculated.

Here, the axial displacement of the ball nut 42 in the axial direction occurs within the area where the thread groove 40 formed on the outer periphery of the column shaft S is formed. By corresponding to the entire rotation range in both directions, the steering angle calculation unit A can determine the absolute rotation angle of the column shaft S in the rotatable range, and use this result to determine the entire steering wheel operation range. The absolute steering angle can be detected over the entire range.

The displacement sensor 43 is a ball nut.
The MR sensor provided on the outer surface of 42 is sensitive to the magnetic target 46. However, the MR sensor is not limited to this configuration and may be an optical sensor sensitive to the slit on the outer surface of the ball nut 42, as in the first embodiment. Similar to the third embodiment, a displacement sensor that contacts the outer surface of the ball nut 42 and detects the displacement of the detection rod according to the displacement of the ball nut 42 may be used.

Further, in the above-mentioned first to fourth embodiments, the configuration for detecting the rotation angle of the column shaft S has been described. However, in the present invention, the operation such as the pinion shaft in the rack and pinion type steering mechanism is operated. The present invention can be applied to all purposes for detecting the rotation angle of a shaft that rotates a plurality of times around the shaft according to the operation of the means.

Furthermore, the configuration of the fourth embodiment of the steering angle detecting device shown in FIG. 6 is arranged in the steering mechanism such as the rack shaft in the rack and pinion type steering mechanism, and the axial length for steering is set. It can be used for detecting the movement of the steering shaft that moves in the direction. FIG. 7 is a cross-sectional view of a main part showing an embodiment for detecting the movement of the steering shaft.

Reference numeral 6 in the drawing denotes a rack shaft as a steering shaft, which is supported inside a rack housing 60 having a cylindrical shape so as to be movable in the axial direction. The rudder angle detecting device 5 for detecting the movement of the rack shaft 6 as described above includes a displacement sensor (MR sensor) 50 attached to the rack housing 60 so as to face the outer surface of the rack shaft 6, and an inside of the displacement sensor 50. And a magnetic target 51 provided over the entire length of the moving stroke on the outer surface of the rack shaft 5 facing the above. The magnetic target 51 is the magnetic target shown in FIG.
Similar to 46, it has a plurality of magnetized portions arranged at regular intervals in the axial direction.

With the above structure, when the rack shaft 6 moves in the axial direction in the rack housing 60 as shown by the white arrow in the figure, the displacement sensor 50 causes the magnetic target 51 to be magnetized. It produces an output that changes periodically with each passage of a section. This output is given to the steering angle calculation unit A. In the steering angle calculation unit A, the movement amount of the rack shaft 6 is obtained based on the output of the displacement sensor 50 as described above.
The steering angle is calculated using this movement amount.

[0040]

As described in detail above, in the steering angle detecting device according to the present invention, the rotation angle of the shaft that rotates a plurality of times according to the operation of the steering means can be detected over the entire rotatable range. It is possible to detect the absolute steering angle, which is used not only for controlling the power steering device but also for various controls such as traction control, ABS control, suspension control, etc., with a simple configuration and with high accuracy, without requiring complicated calculation processing. The present invention has excellent effects such as the above.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of a steering angle detection device according to the present invention.

FIG. 2 is a perspective view of a rotating disk used as a rotating body in the steering angle detecting device shown in FIG.

FIG. 3 is a side sectional view showing a second embodiment of a steering angle detecting device according to the present invention.

FIG. 4 is a side sectional view showing a third embodiment of a steering angle detecting device according to the present invention.

5 is a perspective view of a cam plate used as a rotating body in the steering angle detecting device shown in FIG.

FIG. 6 is a side sectional view showing a fourth embodiment of a steering angle detecting device according to the present invention.

FIG. 7 is a cross-sectional view of essential parts showing an embodiment for detecting movement of a steering shaft.

[Explanation of symbols]

1-5 rudder angle detector 13 Rotating disk (rotating body) 14 Optical sensor (detection means) 17 target 20 Detection gear (rotating body) 21 MR sensor 30 Cam plate (rotating body) 31 Cam surface (displacement part) 32 Displacement sensor (detection means) 42 Ball nut (displacement body) 43 Displacement sensor (detection means) 50 Displacement sensor (detection means) A rudder angle calculation unit H housing S column shaft

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takeo Iino             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. (72) Inventor Tomoho Kada             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. (72) Inventor Shuji Kimura             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. F term (reference) 2F069 AA06 AA83 AA86 BB21 DD20                       GG01 GG04 GG06 GG07 GG09                       GG27 HH09 HH11                 3D030 DB04 DB19                 3D033 CA04 CA18 CA22 CA29

Claims (2)

[Claims] 1. A steering angle detection device, which is arranged in the middle of a shaft that rotates a plurality of times around an axis in response to an operation of a steering means, and detects a rotation angle of the shaft, wherein one rotation is made by transmission from the shaft. A rotating body that rotates within, a plurality of targets that are arranged in parallel on the rotating circumference of the rotating body and that change in position in the circumferential direction according to the rotation, and a target of the target at a predetermined position on the rotating circumference. A rudder angle detecting device comprising: a detecting unit that detects a displacement. 2. A rudder angle detecting device, which is arranged in the middle of a shaft that rotates a plurality of times around an axis in response to an operation of a steering means, and detects a rotation angle of the shaft, wherein one rotation is made by transmission from the shaft. A rotating body which rotates within the rotating body; a displacement portion which is provided in a part of the rotating body and which changes its position in the radial direction in response to the rotation; and a detection means which detects displacement of the displacement portion. A characteristic rudder angle detector.