JPH0731121Y2 - Rudder angle sensor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a steering angle sensor for detecting a rotation angle of a steering wheel in an automobile or the like.

2. Description of the Related Art In a four-wheel steering vehicle or the like in which a steered angle of rear wheels is controlled according to a steered angle of front wheels, a disc having a plurality of slits as a steered angle detecting means of a front wheel and fixed to a steering shaft; It consists of a combination of a light emitting element and a light receiving element mounted on a fixed side member such as a steering column so as to face each other across a disc, and the rotation angle of the steering shaft is detected by the number of pulses of the light receiving element received through the slit. So-called optical incremental rotary encoders have been used in the past (for example, the actual development 59
-136375 gazette).

Similarly, it comprises a small gear serration-coupled to the steering shaft as a turning angle detecting means for the front wheels, and a potentiometer whose output voltage is changed by rotation of a large gear meshing with the small gear. The steering shaft is controlled by the output voltage of the potentiometer. A so-called absolute type steering angle sensor for detecting the rotation angle of the has been conventionally used (for example, see Japanese Utility Model Laid-Open No. 62-14308).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the so-called incremental steering angle sensor disclosed as the first prior art in the above, a reference position (for example, the neutral position of the steering shaft) has to be detected, and a predetermined vehicle speed is used for detecting the reference position. When the above-described method of determining that the vehicle is traveling straight ahead when it has continued for a predetermined time or more is used, the steering angle is not detected until the determination is made.

The so-called absolute type steering angle sensor disclosed as the second prior art can detect the steering angle at any time, but the neutral position of the steering shaft (that is, the steering wheel angle of 0 °) and the output voltage of the potentiometer are supplied to the potentiometer. It is necessary to preliminarily match the point at which the voltage becomes 1/2 (that is, the central point of the steering angle sensor). In this case, there is a limit to the number of serration teeth even if trying to match them by selecting the engagement of serration teeth, so match only with the pitch per tooth (for example, if the number of teeth is 36, 360 ° / 36 = 10 °). It has a problem that it cannot do it.

The present invention provides a rudder angle sensor that can accurately match the steering wheel angle 0 ° point and the central point of the rudder angle sensor with one touch when an absolute type rudder angle sensor is used to detect the turning angle at any time. The purpose is to do.

Means for Solving the Problems The present invention is to mount a rudder angle sensor main body incorporating an absolute type rotation angle detector on a steering column, and the drive shaft of the rotation angle detector is rotated with the rotation of the steering shaft to rotate the rudder angle sensor. In the rudder angle sensor adapted to detect, the gear shaft of the driven gear that meshes with the drive gear fixed to the steering shaft is rotatably supported by the rudder angle sensor body, and the drive shaft and the gear shaft are It is characterized in that they are connected via a clutch mechanism.

Action The present invention adopts the above-mentioned configuration, so that the electrical midpoint of the absolute type rotation angle detector, that is, the output voltage of the rotation angle detector is 1/2 of the power supply voltage supplied to the rotation angle detector. Can be easily and accurately matched with the point where the steering wheel angle becomes zero.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 to 4, 1 is a steering shaft, 2 and 4 are disk casings, 3 is a disk assembled to the steering shaft 1 while being fitted and sandwiched between the disk casings 2 and 4, Three
A plurality of slits 3a are provided at equal intervals over the entire circumference in the portion near the outer circumference.

Reference numeral 5 denotes a steering column that rotatably supports the steering shaft 1. The steering column 5 includes a light emitting element 6a and a light receiving element 6b which are made of synthetic resin and which face each other across the slit portion of the disk 3. The rotary encoder type turning speed sensor main body 6 having the above is fixed by using tapping screws 7, 7.

The disk 3 and the disk casings 2 and 4 rotate integrally with the steering shaft 1, and the light beam emitted by the light emitting element 6a accompanying the rotation of the disk 3 passes through the light emitting element 6a portion every time the slit 3a passes through the slit. Through the light receiving element
The light is received at 6b, converted into electric pulses, and the rotational angular velocity of the steering shaft 1 is detected from the number of electric pulses per unit time.

Reference numeral 8 denotes the mounting bolts 9 and 9 so as to occupy a position across the steering column 5 on the side opposite to the steering speed sensor body 6 and in the axial direction of the steering column 5 offset from the steering speed sensor body 6. The steering angle sensor main body is screwed and fixed to the steering speed sensor main body 6, and the steering column 5 is axially crushed and deformed at the time of a frontal collision of the vehicle by making the mounting structure of the steering angle sensor main body 8 as described above. When the fixing portion formed by the tapping screws 7 and 7 breaks, not only the turning speed sensor main body 6 but also the steering angle sensor main body 8 fall off, so that the collision energy can be sufficiently absorbed by the crushing deformation.

Reference numeral 10 denotes a rotation angle detector attached to the rudder angle sensor main body 8, 11 denotes a shaft of the rotation angle detector 10, which is rotatably fitted to the end of the rotation angle detector 10 and has a divergent conical surface portion 11a. A tubular member to which a worm wheel 12 meshing with a worm gear 14 is attached and fixed, and 13 has a square hole fitted into a prismatic detent portion 10a provided in the rotation angle detector 10 and has an outer circumference of the above-mentioned cylinder. A wedge member 13a, which is formed in a shape that abuts the diverging conical surface portion 11a of the member 11 and transmits a rotational force, and which is provided with a groove into which a forked portion 15a, 15a of a positioning jig 15, which will be described later, fits is provided over the entire circumference, The wedge member 13a is screwed into a screw member provided on the tip of the shaft of the rotation angle detector 10, and a spring member 13b that abuts the conical surface portion 11a of the tubular member 11 to urge it in the direction of transmitting the rotational force. Above spring member
A clutch mechanism consisting of an adjusting nut 13c for adjusting the urging force of 13b, and 14 is a worm gear fixedly attached to the steering shaft 1 and meshing with the worm wheel 12.

As shown in FIG. 5, reference numeral 15 designates a flat plate-shaped sheet metal member, and is provided with forked portions 15a, 15a fitted in the groove portion of the wedge member 13a at one end and a notch portion 15b serving as a finger hook portion at the other end. With the positioning jig 15, as shown in FIG.
When a and 15a are engaged with the groove provided on the outer periphery of the wedge member 13a, the wedge member 13a moves rightward in FIG. 3 against the biasing force of the spring member 13b, and as a result, the tubular member 11 As shown in FIG. 3 and FIG. 4 which is a sectional view taken along line CC of FIG. 3, the conical surface portion 11a and the wedge member 13a, which widen toward the end, form a predetermined gap.
13a square hole and rotation angle detector 10 prismatic detent 10a
The transmission of the rotational force between the rotation angle detector 10 and the tubular member 11 which rotate integrally with the wedge member 13a is blocked by the engagement with the above, and the shaft of the rotation angle detector 10 rotates freely. Become mobile. In the above, as shown in FIGS. 6 and 7, the output voltage V _s of the rotation angle detector 10 is set to 1/2 of the power supply voltage V _c supplied to the rotation angle detector 10, and the steering wheel operation is performed. When the steering wheel 1 has a steering wheel angle of 0, that is, in a neutral position where the vehicle can travel straight, the positioning jig 15 can be moved upward by hooking the notch 15b of the positioning jig 15 with a finger.
Since the engagement between the bifurcated portions 15a, 15a and the groove portion of the wedge member 13a is released, between the rotation angle detector 10 and the tubular member 11 which rotate integrally with the wedge member 13a. Since the rotational force is transmitted, the steering shaft 1 is connected to the tubular member 11 by the meshing of the worm gear 14 and the worm wheel 12.
The absolute steering angle can be detected by the rotation angle detector 10 of FIG.

According to the present invention, by adopting the above-mentioned configuration, the electrical midpoint of the absolute type rotation angle detector, that is, the output voltage V _s of the rotation angle detector is 1 V of the power supply voltage V _c supplied to the rotation angle detector. Since the point at / 2 and the point at which the steering wheel angle is zero can be easily and accurately matched, the workability is extremely good even during vehicle maintenance, inspection and repair work during vehicle production. Further, since the rudder angle sensor main body including the mechanism for interrupting the rotational force transmission, that is, the neutral position adjusting portion between the steering shaft and the rotational angle detector can be made extremely compact, it is advantageous in terms of space and increases in cost. Can be kept small.

As an absolute type rotation angle detector, it is possible to use an absolute type rotary encoder that attaches a code to the rotating disk and reads the code of the disk when the rotation axis stops to detect the rotation angle. Needless to say, an example in which a combination of a worm gear and a worm wheel is used as a combination of a driving gear and a driven gear has been shown, but it goes without saying that a combination of spur gears having different numbers of gear teeth may be used.

In the above embodiment, the gear shaft of the driven gear is composed of the tubular member rotatably fitted to the drive shaft of the rotation angle detector. However, as shown in FIG. A gear shaft 16 having a conical surface part 16a and having a worm wheel 12 mounted and fixed on the outer periphery thereof is rotatably supported by the steering angle sensor main body 8 and is fitted on the drive shaft 10a so as to be slidable only in the axial direction. The conical surface portion 16a of the above-mentioned gear shaft 16 which spreads toward the end
A rotation angle detector 10 mounted with a wedge member 13a that abuts against and transmits a rotational force and a spring member 13b that biases the wedge member 13a,
Even if the wedge member 13a is attached to the steering angle sensor main body 8 so as to be opposed to the conical surface portion 16a of the gear shaft 16 which spreads toward the end, the same effect as in the above embodiment can be obtained.

Further, in each of the above-described embodiments, an example in which a diverging conical surface portion is provided on the gear shaft side of the driven gear and a wedge member is provided on the drive shaft side of the rotation angle detector is shown, but the configuration may be reversed. Of course, instead of the combination of the diverging conical surface portion and the wedge member, both may be flat.

As described above, according to the present invention, the rudder angle sensor body having the absolute type rotation angle detector is mounted on the steering column, and the drive shaft of the rotation angle detector rotates as the steering shaft rotates. In a rudder angle sensor configured to detect a rudder angle, a gear shaft of a driven gear that meshes with a drive gear fixed to a steering shaft is rotatably supported by the rudder angle sensor body, and the drive shaft and the gear shaft are By connecting and via the clutch mechanism, the electrical middle point of the absolute type rotation angle detector, that is, the output voltage of the rotation angle detector becomes half the power supply voltage supplied to the rotation angle detector. Since it is possible to easily and accurately match the point at which the steering wheel angle is zero when the vehicle goes straight on, make sure to perform maintenance and repair work on the vehicle during production. However, the workability was extremely good, and the steering angle sensor main body including the rotational force cutoff mechanism between the steering shaft and the absolute type rotation angle detector, that is, the neutral position adjusting part, could be made extremely compact. Not only is it advantageous in terms of space, but it is also possible to bring about great practical effects, such as a small increase in cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a sectional view taken along the line B in FIG. FIG. 4 is a sectional view taken along line CC of FIG. 3, FIG. 5 is a front view of the positioning jig, and FIG. 6 is an explanatory view showing a circuit in the rotation angle detector. FIG. 8 is a characteristic diagram of the output voltage of the rotation angle detector with respect to the steering wheel angle, and FIG. 8 is a cross-sectional view of essential parts showing another embodiment relating to the connection between the gear shaft of the driven gear and the drive shaft of the rotation angle detector. 1 ... Steering shaft, 2, 4 ... Disk casing, 3 ... Disk, 5 ... Steering column, 6 ... Steering speed sensor body, 8 ... Steering angle sensor body, 10 ... Rotation angle detector, 11 ... Cylindrical member, 11a ... Conical surface part, 12 ... Worm wheel, 13 ... Clutch mechanism, 13a ... Wedge member, 13b ... Spring member, 13c ... Adjustment nut, 14 ... Worm gear, 15 ... Positioning jig, 16 ... Gear shaft.

Claims (3)

[Scope of utility model registration request] 1. A steering angle sensor main body having an absolute type rotation angle detector mounted therein is mounted on a steering column, and a drive shaft of the rotation angle detector is rotated with rotation of a steering shaft to detect a steering angle. In the steering angle sensor, a gear shaft of a driven gear that meshes with a driving gear fixed to a steering shaft is rotatably supported by the steering angle sensor main body, and the drive shaft and the gear shaft are connected via a clutch mechanism. A rudder angle sensor characterized in that 2. A clutch mechanism according to claim 1, wherein the conical surface portion of the drive shaft or the gear shaft is a divergent conical surface portion provided at the tip end portion, and the other is axially constrained in the rotational direction. A wedge member that is fitted so as to be slidable only on the end of the cone and abuts against the diverging conical surface portion to transmit the rotational force; and a spring member that urges the wedge member in the direction of pressing the diverging conical surface portion. The rudder angle sensor is characterized by being. 3. The gear shaft of the driven gear according to claim 1 or 2, comprising a tubular member rotatably fitted to the drive shaft of the rotation angle detector. A characteristic rudder angle sensor.