JPH0325076A - Steering angel detecting sensor for steering shaft - Google Patents

Abstract

PURPOSE:To detect a steering shaft to be outside the neutral position by providing a photoelectric transducer for detecting the steering angle of a first disc by a light emitting component and a light receiving component positioned between the first disc and a second disc. CONSTITUTION:When a steering shaft 20 is steered either to the right or to the left by the specified angle, a first disc 21 is rotated together with the steering shaft 20, but the seconds of arc of a second disc 23 is differentiated from the steering angle of the first disc 21 by a torque transmitting mechanism 30 interposed between the first and second discs 21, 23. A steering angle neutral position detecting slit 22 formed at the first disc 21 is not therefore conformed to a steering angle neutral position determining slit 24 formed at the second disc 23, and a photoelectric transducer detects that the steering shaft 20 is not in the neutral position.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sensor for detecting the turning angle of a steering shaft of an automobile.

BACKGROUND OF THE INVENTION With regard to the above, for example, Japanese Patent Application Laid-Open No. 13983/1983 discloses a structure shown in FIGS. 7 and 8. In addition, when this 1 is 1, it is an example of FM design as a sensor that detects the rotation ffI of the crank/yaft, and the rotation IPI
A sun gear 2 with the number of teeth N1 fixed to the ψ+h end of IIl and a disk 3 with internal teeth of tooth number N arranged in the radial direction of the sun gear 2 are connected to the idler planet 119.
4 + . . . , a reduction mechanism of N, /N2 is constructed between the rotary shaft 1 and the disk 3. In other words, the disk 3 is set to rotate half a rotation while the rotating shaft 1 rotates once. this disc 3
The slit 5 for the 720° signal, the slit 1 and 6 for the 180' signal, and the many slits 7 and 7 for the I0 signal.
... are provided in three stages from the inside to the outside in the radial direction, and the light emitting elements 10a, fob, 10c are arranged in the detection section 9 located at positions sandwiching the disk 3.
and light receiving element 11. a,llb. The positions of the respective slots 5, 6, and 7 are detected by a photoelectric transducer consisting of a
The pulse signal is extracted for each pulse signal.

Problems to be Solved by the Invention However, when such a conventional sensor for detecting the rotation of a crankshaft is applied as it is to a sensor for detecting the turning angle of a steering shaft, the turning angle of the steering shaft or the sun gear 2 and the planets are Since the signal is transmitted to the disk 3 via the gear 4, there is a problem in that the accuracy of the 1° signal decreases due to the pack run between the gears. If the gear 2 is provided with a 1° signal slit 5 to improve accuracy, the size of the sun gear 2 must be expanded to at least the size of the disk 3, which would increase the size of the entire device. There is the issue of inviting people.

Furthermore, in the above example, each thrift 5 is placed on ■ disks 3.
, 6.7 are formed, so if this disc 3 is used as a steering angle sensor for a steering shaft as described above, when the steering shaft is turned from the neutral position to either the left or right direction by 3600 degrees, Since the same signal as when the steering shaft 20 is at the neutral position is detected, there is a problem that the neutral position of the steering angle is incorrectly determined.

Therefore, the present invention improves such a conventional rotation angle detection sensor for a rotating shaft to improve detection accuracy without increasing the size of the entire device. It is an object of the present invention to provide a steering angle detection sensor that does not cause erroneous determination of the neutral position of the steering shaft even when applied to the steering angle detection sensor.

Means for Solving the Problems In order to achieve the above object, the present invention is fixed to a steering shaft and rotates integrally with the steering shaft, and has a slit for detecting a rotation angle and a slit for detecting a steering angle neutral position at a predetermined position. A shaped first disk is arranged in parallel at a portion facing the first disk, and rotational force is transmitted from the first disk via a torque transmission mechanism having a specific gear ratio. , a slit for determining the neutral position of the steering angle is formed at a position corresponding to the slit for detecting the neutral position of the steering angle.
and a rechargeable transducer that detects the turning angle of the first disk using a light emitting element and a light receiving element arranged at positions sandwiching the first disk and the second disk. It is structured as a steering angle detection sensor.

According to this configuration, when the steering shaft is set to the neutral position, the slit for detecting the neutral steering angle position formed in the first disk and the slit for determining the neutral steering angle position formed in the second disk are activated. Since these are relatively coincident with each other, it is detected that the steering shaft is in the neutral position by a photoelectric transducer placed between the first disk and the second disk.

Next, when the steering shaft is turned to the left or right by a predetermined angle, the first disc rotates together with the steering shaft, but the torque transmission interposed between the first disc and the second disc causes the first disc to rotate together with the steering shaft. 2nd by mechanism
The displacement angle of the second disc can be made different from the steering angle of the first disc. Therefore, even when the first disk is turned 3600 degrees to the left or right, the second disk will not be in the same rotational state, and therefore, the steering angle neutral position detection slot formed on the first disk , the steering angle neutral position determining slit formed in the second disk does not match, and the photoelectric transducer detects that the steering shaft is not at the neutral position.

Embodiment Hereinafter, one embodiment of the steering angle detection sensor according to the present invention will be described in detail based on the drawings.

In the structure shown in FIGS. 1 and 2, 20 is a steering shaft, and a first disk 21 is integrally fixed to this steering shaft 20. The peripheral edge of this first disk 21 has l0 similar to the conventional example.
The signal slits 7, 7... are formed densely,
Further, only one substantially arcuate steering angle neutral position detection slit 22 is formed inside the 10 signal slits 7, 7, . . . .

On the other hand, 23 is a second disk arranged in parallel at a portion facing the first disk 21, and this second disk has a donut shape with a missing center portion, and
The second disk 23 has an outer diameter slightly smaller than the first disk 21 and is connected to the first disk 2l via a torque transmission mechanism 30 having a specific gear ratio, which will be described later. Only one slit 24 for determining the neutral steering angle position is formed at one end of the peripheral edge of the steering wheel. In the illustrated example, the slit 24 has a shape obtained by cutting out one end of the second disk 23, but it may be an arc-shaped slit similar to the slit 22.

This slit 24 for determining the neutral steering angle position is located at a portion corresponding to the slit 22 for detecting the neutral steering angle position formed on the first disk 21 side, and the size of the slit 24 is larger than that of the slit 22. It is set to be wider in the circumferential direction.

The structure of the torque transmission mechanism 30 described above will be explained below. That is, 3l is a large diameter gear, and this gear 31 is connected to the first gear.
A threaded portion 21a is formed in advance on one side of the disk 21.
are screwed together. On the other hand, 32 is a small diameter gear, and this gear 32 is screwed into a threaded portion 23a formed in advance on one side of the second disk 23. The large-diameter gear 31 and the small-diameter gear 32 are integrally connected at their center portions by a connecting shaft 33. 35 is the connecting shaft 3
3 is a fixed body that is rotatably inserted therethrough and has a stepped portion 35a that supports the inner peripheral portion of the second disk 23. Further, supports 36 and 36 for supporting the rotation of the second disk 23 are disposed at a plurality of locations on the outer peripheral side of the second disk 23. Therefore the second disk 2
3 is rotatably supported around the steering shaft 20 by supports 36 and 36 located on the outer circumferential side and a stepped portion 35a of the fixed body 35 located on the inner circumferential side.

The operation of the present invention according to such a configuration will be explained below.

Figure 3 (Δ) (B) shows the first disc 21 and second disc 2 when the steering shaft 20 is in the neutral position.
As shown in the figure, the steering angle neutral position detection groove 2 formed on the first disk 2l is shown in FIG.
2 and a steering angle neutral position determination slit 24 formed in the second disk 23 are relatively aligned. Therefore, as shown in FIG. 2B, the steering shaft 2 is detected to be in the neutral position, and furthermore, by the light emitting element 40b and the light receiving element 4lb,
A pulse signal for every 1° of the steering shaft 20 can be extracted.

Next, assume that the steering shaft 20 is steered to either the left or right by a predetermined angle θ1.

At this time, the number of teeth of the large diameter gear 31 shown in FIG.
l+ The number of teeth of the small diameter gear 32 is K, and the distance between the large diameter gear 3l and the center axis O of the steering shafts 1 and 20 is Q I+ The distance between the small diameter gear 32 and the center axis O of the steering shaft 20 Let the distance be Q. Therefore, the gear ratio between gear 31 and gear 32 is K, /K.

As mentioned above, the steering shaft 20 is rotated at an angle θ1
When the steering wheel is turned, the first disc 2 is turned in response to this turning.
1 rotates by an angle θI. If the amount of movement of the gear 31 on the radius a1 at this time is Q,/, then f2. '1(,・θ1 Similarly, if the amount of movement of the gear 32 at the radius e is Q,', then the displacement angle θ, of the second disk 23 is K, ≧
When Kt, L< Qt, θ, <θ1, and as shown in FIG. 1, the displacement angle θ of the second disk 23 can be made smaller than the turning angle θ1 of the first disk 2l. . Therefore, as shown in FIG. 4(A), when the first disc 21 fixed to the steering shaft 20 is steered 360° in either the left or right direction, the second disc 23 rotates at the same speed. Therefore, the steering angle neutral position detection slit 22 formed on the first disk 21 and the steering angle neutral position determination slit 24 formed on the second disk 23 do not match. As shown in Figure (B), the light emitted from the light emitting element 40a provided in the detection unit 9 placed on both sides of the disks 21 and 23 is blocked by the second disk 23, and transmitted to the light receiving element 41a. Not done. As a result, it is detected that the steering/yaft 20 is not in the neutral position. Note that the pulse signal of the steering shaft 20 for every 1 degree can be continuously extracted by the light emitting element 40b and the light receiving element 4lb.

The number of teeth of the gear K. , K. and steering shaft 2
Distance from 0 to each gear &. , R, can appropriately determine the magnitude of the displacement angle θ.

As an example of implementing the present invention, as shown in FIG. When the frontage angle of the steering angle neutral position determining groove 24 formed in the steering angle neutral position determination groove 23 is set to 30 degrees, the slit 22 rotates once as the first disk 21 rotates from the illustrated state and aligns with the slit 24 again. The angle is 360°-20' = 340'. At this time, the second disk 23 is the same as the first disk 2.
It is necessary that the rotation is at least 30' or more in the opposite direction to l. Therefore, the number of gears K, , K. and distance m 1
2. By setting Qt, when the steering shaft 20 is turned 360° in either the left or right direction, the detection unit 9 is prevented from erroneously determining that the steering shaft 20 is in the neutral position. .

FIG. 6 shows a modification of the present embodiment, and the basic configuration is the same as that of FIG. 2, and the same reference numerals are used to indicate the same. That is, in the main rule, the gear ratio K t/K is changed by changing the south number of the gears 31 and 32 from the layout and other aspects.
The case where + is set to 1 or more is shown, and in such a case, the diameter length of the gear 32 must be set larger than the diameter length of the gear 3l.

Therefore, in such a case, an embossed portion 21G may be formed in the middle of the first disk 21, and the second disk 23 may be accommodated within the embossed portion 21C.

In this example, the displacement angle of the second disk is set to be larger than the steering angle of the first disk when the steering shaft is turned by a predetermined angle to either the left or right.

Effects of the Invention As explained in detail above, according to the steering/yaft turning angle detection sensor according to the present invention, the steering 7
A first disc that is fixed to the shaft and rotates integrally therewith, and has a slot for detecting a rotation angle and a slot for detecting a neutral position of steering angle formed at predetermined positions, and faces the first disc. The rotational force is transmitted from the first disk through a torque transmission mechanism having a specific gear ratio, and the steering angle neutral position is set at a position corresponding to the steering angle neutral position detection slit. A rechargeable device that detects the turning angle of the first disk using a second disk in which a determining slit is formed, and a light emitting element and a light receiving element that are placed between the first disk and the second disk. Since the structure is equipped with a transducer, the following effects are brought about. That is, when the steering shaft is placed in the neutral position, the slit for detecting the neutral steering angle position formed in the first disk and the slit for determining the neutral steering angle position formed in the second disk are relatively Since they match, the Koji transducer detects that the steering shaft is in the neutral position, but when the steering shaft is turned to the left or right by a predetermined angle, the first disc and the first disc match. The displacement angle of the second disk can be made different from the steering angle of the first disk by the torque transmission mechanism interposed between the second disk and the first disk. Even when the steering is turned, the second disc is not in the same rotational state, so a slit for detecting the neutral steering angle position formed in the first disc and a neutral position of the steering angle formed in the second disc are used. The determining slits do not match, and the photoelectric transducer can detect that the steering shaft is not in the neutral position.

Furthermore, in the present invention, since the turning angle of the steering wheel/yaft is directly transmitted to the first disk, backrun that occurs when using gears or the like is avoided. This has the advantage that the deterioration in detection accuracy caused by the problem No. 4 is eliminated, and an increase in the size of the device itself is prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the basic configuration of the present invention, FIG. 2 is a sectional view of main parts showing a specific example of the structure, FIGS. 3 and 4 are schematic diagrams showing the operation of the present invention, FIG. 5 is a partially enlarged view of FIG. 1, FIG. 6 is a sectional view of a main part showing a modification of the present invention, and FIG.
The figure is a schematic diagram showing an example of a conventional rotation angle detection sensor.
The figure is a view taken in the direction of the ■ arrow in FIG. DESCRIPTION OF SYMBOLS 20... Steering shaft, 21... First disk, 22... Rudder angle neutral position detection slot, 23
...Second disk, 24...Slit for determining the steering angle neutral position, 30...Torque transmission mechanism, 31.32...Gear, 33...Connection shaft, 35...Fixed body, 40a, 40b... Light emitting element, 4 18.4 lb... Light receiving element, Fig. 1 Fig. 3 (A) (B) Fig. 2 36 Fig. 4 9 Fig. 5 Fig. 6 Fig. 7 Fig. 6 Figure 8

Claims (1)

[Claims] (1) A first disk that is fixed to the steering shaft and rotates together with the steering shaft, and has a rotation angle detection slit and a steering angle neutral position detection slit formed at predetermined positions, and is opposed to the first disk. The rotational force is transmitted from the first disk through a torque transmission mechanism having a specific gear ratio, and the steering angle neutral position is set in a position corresponding to the steering angle neutral position detection slit. a second disk in which a position fixing slit is formed;
and a photoelectric transducer that detects the steering angle of the first disk by means of a light emitting element and a light receiving element arranged at positions sandwiching the first disk and the second disk. Rudder angle detection sensor.