JPS59222702A - Rotary-angle detecting device - Google Patents

Abstract

PURPOSE:To improve detecting accuracy, by providing a sliding contact between a disk shaped rotor, which is rotated together with rotated angle detecting body as a unitary body, and a bearing member, which supports the rotor so that the rotor is freely rotated, by a conical surface, and elastically energizing the rotor to the conical surface. CONSTITUTION:A bearing 26 is provided between a rotor 23 and a rotary shaft 22. The bearing 26 has a conical tapered part 27, which is coupled with the upper end part, and a flange part 28, which is protruded from the lower end part in a flange shape. The cross section of the tapered part 27 is coupled with the upper end part of the main body of the bearing 26, which is formed in a tapered shape. The outer surface of the tapered part 27 is contacted with the conical inner wall, which is formed at the upper end side of the axial hole of the rotor 23. Thus the sliding-contact engaging surface of the rtor 23 and the bearing 26 is constituted.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a rotation angle detection device for detecting the rotation angle of an object to be detected such as a throttle valve opening of an internal combustion engine, and particularly to an improvement of a bearing portion of a rotor thereof.

(Prior art) As a conventional rotation angle detection device, for example,
The one described in Japanese Patent No. 6961 is known. This device is a throttle sensor that detects the opening of the throttle valve.
To explain based on FIG. 1.2, 1 is a throttle valve shaft integrated with the throttle valve, and 2 is a rotating shaft that fits into the throttle valve shaft 1 and rotates integrally with the throttle valve shaft 1. The rotating shaft 2 has an arm 3 extending in the radial direction, and this arm 3 engages with a pair of engagement pieces 5 provided on a disk-shaped rotor 4. The rotor 4 is the rotating shaft 2
through the arm 3, and rotates in conjunction with the rotating shaft 2, that is, the throttle valve shaft 1. A cylindrical bearing 6 that rotatably supports the rotor 4 has a shaft hole through which the throttle shaft 1 freely passes, and is fixed to a base plate 7 by its lower end flange. Further, a predetermined gap is provided between the outer peripheral surface of the cylindrical portion of the bearing 6 and the inner peripheral surface of the shaft hole of the rotor 4. Between the lower end surface of the rotor 4 and the lower end of the bearing 6 formed in the shape of a flange, there is an annular wave shape having two wave peaks.
This wave washer 8 urges the rotor 4 in the axial direction (upward in FIG. 2) and presses it against the ring plate 9 fixed to the upper end of the bearing 6, applying a predetermined braking torque to the rotor 4. There is. Further, a guide groove 0 extending in the circumferential direction is formed on the upper surface of the rotor 4, and a portion 10a of the J guide groove 10 is curved outward in the radial direction.

The base end of the bottle 11 inserted into the guide groove 10 is connected to the connector 1.
It is fixed to the tip of the movable contact member 13 supported by i, and on both sides (in the horizontal plane) of the movable contact member 13 of i,
Fixed contact member 14.1 also fixed to connector 12
5 are arranged.

Therefore, when the rotor 4 rotates in accordance with the opening degree of the throttle valve 1, the bottle 11 is guided in the guide i@10 and is displaced in the radial direction of the rotor 4, and the movable contact member 13 and the fixed contact member 14, 15 The opening degree of the throttle valve is detected by opening and closing (approaching and separating) the valve. At this time, an appropriate braking torque is applied to the rotor 4 by the wave washer 8, thereby preventing a decrease in the detection accuracy of the throttle valve opening and deterioration of the rotational response of the rotor 4 (hunting, overshoot, etc.).

However, in such a conventional throttle sensor (rotation angle detection device), the bearing 6 is cylindrical, and a predetermined gap is provided between the bearing 6 and the rotor 4 (the bearing 6 and the rotor 4 are However, since the wave washer 8 has two wave crests in the circumferential direction, the pressing force varies in strength, so the pin 11 may ride on a part 10a of the guide groove 10 (ride on the protrusion) and perform the switching action. If this is done, a radial force acts on the rotor 4, causing the rotor 4 to deviate in the radial direction or become inclined without being able to maintain its horizontal state. As a result, the radial stroke of the pin 11 and the rotation angle of the rotor 4 do not correspond, resulting in a problem that the detection accuracy of the throttle valve opening is reduced.

(Objective of the Invention) Therefore, the present invention provides a rotor that is rotatably supported by a bearing having a conical sliding surface, thereby preventing the deflection barb of the rotor from collapsing and detecting the rotation angle of a rotated angle detection object. The purpose is to improve displacement detection accuracy.

(Structure of the Invention) A rotation angle detection device according to the present invention includes a disc-shaped rotor that rotates integrally with a rotated angle detection object, a bearing member that rotatably supports the rotor, and a rotor that rotates in accordance with the rotation of the rotor. and a detection means for detecting rotational angle displacement of the rotated angle detecting body by displacing in the radial direction of the rotor. It has a structure in which the surface is elastically biased.

(Example) Embodiments of the present invention will be described below based on the drawings.

3 to 6 show an embodiment of the present invention. In this embodiment, the rotation angle detection device is applied to a throttle sensor that detects the opening degree of a throttle valve of an internal combustion engine.

First, to explain the configuration, in Fig. 3.4, 21 is a throttle valve shaft connected to a throttle valve (not shown), and 22 is a notch in the upper end of the throttle valve shaft 21 that fits into the throttle valve shaft 21. It fits into this. ) It is a rotating shaft made of resin that is integrated with the throttle valve shaft 21, that is, rotates integrally with the throttle valve. Rotating shaft 22
The rotor 23 (together with the throttle valve shaft 21) is inserted through the center (shaft hole) of a disk-shaped rotor 23 made of resin, and has an arm U extending in the radial direction at its upper end.

A pair of engaging pieces 5 that engage with the arms 24 are protruded from the upper surface of the peripheral edge of the cubic rotor blade, and the rotor blade is attached to the rotating shaft 2.
The rotational force of 2 is applied via the arm 24, and the receiver rotates in conjunction with the rotating shaft 22. A bearing (bearing member) 26 is interposed between the rotor blade and the rotating shaft 22 (throttle valve shaft 21). The throttle valve shaft 21 is loosely inserted into the bearing 26.) The bearing 26 has a conical tapered part 2 fitted to its upper end.
7, and a flange portion 28 projecting like a flange from the lower end.
It has . The tapered portion 27 has a tapered cross section such that the diameter increases upward in FIG. 4 along the axial direction, and is fitted into the upper end of the main body of the bearing 26. The outer circumferential surface (conical surface) of the tapered portion 27 comes into contact with a conical inner wall surface formed at the upper end side of the shaft hole of the rotor 23, thereby forming a sliding engagement surface between the rotor 23 and the bearing 26. ing. Further, the tapered portion 27 is positioned by a collar-shaped ring plate 29 fixed to the bearing 26 body, and this ring plate 29 prevents the tapered portion 27 and the rotor 23 from coming off upward. The tapered portion 27 is manufactured by machining soft iron, and its surface (conical surface) is galvanized. On the other hand, the portion between the flange portions of the bearing 26 is fixed to the sprate 3o. The rotating shaft 22 is prevented from being removed by flanges and claws that are engaged with both upper and lower ends of the bearing 26 body. Therefore, the bearing 26 allows the rotating shaft 22 to be inserted into the shaft hole and rotatably supports the rotor 23. As shown in detail in FIG. 5.6, between the lower end surface of the rotor arm and the flange portion 28, there is an annular wave washer (elastic body) having four wave crests equally spaced in the circumferential direction. 3I is interposed, and this wave washer 31 is connected to the rotor 23.
The rotor 2 is urged in the axial direction (especially upward in FIG. 4).
A predetermined braking torque is applied to 3. Therefore, the wave washer 31 and the ring plate 29 function as a stopper that restricts the displacement of the rotor blade in the axial direction. In Fig. 5.6, A indicates a convex portion (corresponding to a wave crest) of the wave washer 31, and B indicates a concave portion, and the wave washer 31 is made of spring steel and has an inner diameter of 14 mm and an outer diameter of 14 mm. is approximately 18 mm.

Referring again to FIG. 3.4, a guide groove 32 is formed in the upper end surface of the rotor 23 and extends a predetermined length along the circumferential direction of the rotor 23. A pin 33 is inserted perpendicularly thereto. Further, a part of the guide groove 32 is curved, and a part 32a of the guide groove 32 is curved.
has a larger radius than other parts. Pin 33 is connector 3
4, and both sides of this movable contact member 35 (both sides in a substantially horizontal plane)
Fixed contact members 36 and 37 whose rear ends are fixed to the connector 34 are arranged at a predetermined distance apart from each other. This corresponds to (is the same as) the displacement of the rotation angle of the rotor arm until it runs over the part 32a of the rotor 32.

Therefore, when the rotor 23 rotates, the pin 33 is guided in the guide groove 32 and is displaced in the radial direction of the rotor 23 and rides on a portion 32a), opening and closing the movable contact member 35 and the fixed contact members 36 and 37. The rotation angle of the rotor,
In other words, the opening degree of the throttle valve is detected. Note that the connector 34 is fixed to the head plate 30, and each contact member 35.
36. The opening degree of the throttle valve detected by opening and closing of 37 is sent as an electric signal to the outside (for example, to a control unit).
Output. In this embodiment, the throttle valve is the rotated angle detector,
Guide groove 32, pin 33, each contact member 35, 36, 37
, and the connector 34 respectively correspond to the detection means.

Next, the effect will be explained.

When the opening degree of the throttle valve changes depending on the operating state of the engine, the throttle valve shaft 21 and the rotating shaft 22 rotate together by a predetermined angle in response to the opening degree of the throttle valve. The rotational force of the rotating shaft 22 is transmitted to the retaining piece 4 via the arm 24, causing the rotor 23 to rotate in conjunction with the rotating shaft 22. When the rotor 23 rotates, the guide groove 32 uses its portion 32a to displace the pin 33 in the radial direction of the rotor blade, thereby opening and closing the movable contact member 35 and the fixed contact members 36, 37. Thereby, the opening degree of the throttle valve is detected and output from the connector 34 as an electrical signal to the outside. At this time, the rotor 23 is receiving a radial force from the pin 33 due to the displacement of the pin 33 (that is, the rotor 23 is receiving a radial force from the pin 33 as a reaction force when the pin 33 is displaced).
), ``This force is applied when the pin 33 is displaced in the radial direction, and due to the displacement of the pin 33, the movable contact member 3
It acts when 5 opens or closes with any of the fixed contact members 36, 37.

In this case, since the rotor 23 is in sliding contact with the conical surface of the tapered portion 27 of the bearing 26 and is restricted by the wave washer 31, which is a stopper, the rotor 23 is held approximately horizontally and does not tilt. , and rotates on the same plane perpendicular to the axial direction without being displaced in the radial direction. Therefore, the position of the guide groove 32 formed in the rotor 23 does not change in the radial direction and accurately corresponds to the opening degree of the throttle valve. As a result, the detection accuracy of the throttle valve opening degree can be improved. Further, the tapered portion 27 is a soft iron layer, and can be manufactured extremely inexpensively and easily. Furthermore, in the above case, the wave crests of the wave washer 31 are formed at four locations, and the spring force of the wave washer 31 is generated uniformly at four locations in the circumferential direction due to these wave crests, so regardless of the rotational position of the rotor n. The same damping force 1-/'L) is then applied to the rotor shaft.

Incidentally, in the past, since wave crests were formed only at two locations, there were two locations each where the spring force was strong and two locations where the spring force was weak in the circumferential direction of the rotor 23, and the braking torque was not completely uniform. Therefore, depending on the rotational position of the rotor blade, the lower end of the pin 33 comes into contact with the bottom surface of the guide groove 32, causing the rotor 23 to tilt, causing variations in the detection accuracy of the throttle valve opening. However, in this embodiment, the wave crest of the wave washer 31 is set to 4 as described above.
By forming the damper at this location, it is possible to make the braking torque uniform, prevent the rotor from tilting, and reduce variations in the detection accuracy of the throttle valve opening in the rotor's rotational position.

In addition, if the number of wave crests of the wave washer 31 is increased, it is possible to reduce non-uniformity of the spring force in the circumferential direction of the rotor blade and provide stable braking torque to the rotor blade, but on the other hand, if the number of wave crests is too large, This results in a decrease in detection accuracy. In other words, if the number of wave crests is increased within the range in which the same braking torque is obtained, the height of the wave crest (indicated by H in Fig. 6) becomes smaller. If the number of wave crests is increased while keeping the same height, problems such as excessive braking torque and torque will occur. Therefore, the appropriate number of wave crests in the wave wansha 31 is in the range of 3 to 5.
In this embodiment, this number is set to four to reduce variations in detection accuracy.

(Effects) According to the present invention, as a result of being able to prevent the rotor from falling (tilting) at t and 1C, it is possible to improve the detection accuracy of the rotational angle displacement of the rotation angle detection object.

In addition, in the above embodiment, by forming wave crests at four locations on the wave washer that applies braking torque to the rotor, uniform braking torque can always be applied regardless of the rotational position of the rotor, and the throttle valve opening can be adjusted. Variations in detection accuracy can be reduced.

[Brief explanation of drawings]

Figure 1.2 is a diagram showing a conventional throttle valve opening detection device.
FIG. 1 is a perspective view thereof, FIG. 2 is a cross-sectional view thereof, FIGS. 3 to 6 are views showing an embodiment of the rotation angle detection device according to the present invention, and FIG. 4 is a sectional view thereof, FIG. 5 is a plan view of the wave washer, and FIG. 6 is a sectional view taken along the line v-v in FIG. 5. 23-----Rotor, 26-----Bearing, 27--Tapered part (conical surface), 32-37--Detecting means, 31--Elasticity body. Patent Applicant Nissan Motor Co., Ltd. Representative Patent Attorney Ugagun Part Figure 2 Figure 3 U Figure 4

Claims (1)

[Claims] A disk-shaped rotor that rotates together with the rotated angle detection object;
A rotation angle detection device comprising a bearing member that rotatably supports a rotor, and a detection means that is displaced in the radial direction of the rotor in accordance with rotation of the rotor to detect rotation angle displacement of a rotation angle detection object, A rotation angle detection device characterized in that a rotor and a bearing member are brought into sliding contact by a conical surface, and the rotor is urged in the direction of the conical surface by an elastic body.