JPH09209792A - Rotary throttle position sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the early-stage rotary position through the energizing force of a coil spring by utilizing such a construction as the rotation regulation portion of a rotor and the first and the second protrusions of a cover touch with each other so as to conduct the rotation regulation of the rotor, and storing the energizing force in the coil spring. SOLUTION: A support arm 24, to which a brush 25 is fitted, is provided on a rotor 23 which rotates as sliding on the bottom face of a cylinder case 11 having a slit with bottom and has the brush 25 sliding on a resistor 21 provided on the inner wall. A rotation regulation portion 26 which engages with a coil spring 34 and simultaneously regulates rotation is provided on the support arm 24. One pair of protrusions abutting the rotation regulation portion 26 are provide on a cover. Utilizing the protrusions of the cover, energizing force energizing the rotor in a returning direction is granted to the coil spring 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary throttle position sensor used for detecting the position of a rotary throttle shaft of an internal combustion engine.

[0002]

2. Description of the Related Art An internal combustion engine such as a vehicle uses a throttle valve to control the amount of air flowing into the engine. When the throttle valve is opened, a large amount of air is sucked in, and when the throttle valve is closed, a small amount of air is sucked in. The speed of the engine is controlled. This throttle valve is connected to an accelerator petal, and is opened / closed by depressing the accelerator petal.

As a conventional rotary throttle position sensor, the one disclosed in JP-A-7-151508 is known.

A conventional rotary throttle position sensor will be described below with reference to the drawings.

FIG. 7 is a top view in which a cover is removed so that internal components of a conventional rotary throttle position sensor can be seen, and FIG. 8 is a sectional view of the same. In the figure,
Reference numeral 1 is a case having a bottomed groove and a pair of arms 2 provided from the inner wall surface toward the central portion. 3
Is a film resistor having a resistance pattern (not shown) provided along the inner wall surface of the case 1. An external terminal 4 is electrically connected to the film resistor 3 and is connected to the outside of the case 1. Reference numeral 5 denotes a convex rotor provided so as to come into contact with a pair of arms 2 inside the case 1, and a brush 6 which is in sliding contact with the resistance pattern of the film resistor 3 at the convex tip of the rotor 5. have. Here, a small protrusion is provided on the outer periphery of the rotor 5, and the initial rotation position of the rotor 5 is defined by engaging the small protrusion with the recess at the tip of the pair of arms 2 of the case 1. The open end of the case 1 is covered with a metal cover 7
The rotary throttle position sensor was configured by sealing with.

[0006]

SUMMARY OF THE INVENTION In the above conventional configuration,
Since a pair of arms 2 is provided inside the case 1 and the initial rotational position of the rotor 5 is defined by the pair of arms 2, the outer circumference of the rotor 5 is attached to the pair of arms 2 of the case 1 in actual use. There was a problem that contact powder was generated due to the sliding contact, and this contact powder was scattered on the film resistor 3 and an accurate signal could not be obtained.

The present invention solves the above-mentioned conventional problems, and an object thereof is to provide a highly reliable rotary throttle position sensor.

[0008]

In order to achieve the above object, a rotary throttle position sensor of the present invention comprises a cylindrical case having a bottom and a resistor having a resistance pattern provided on the side surface of the inner wall of the case. , A connector terminal for external connection electrically connected to the resistor and a support arm for supporting the brush that is in sliding contact with the resistance pattern of the resistor are provided in a protruding manner, and rotate in sliding contact with the bottom surface of the inner wall of the case. A possible rotor, and a coil spring disposed on the outer circumference of the rotor, one end of which is locked to the case and the other end of which is locked to the support arm of the rotor, and which always applies a biasing force to the rotor in the returning direction. 1 has a concave portion that engages with a hook provided at the opening end of the case, and abuts against a rotation restricting portion provided on the support arm of the rotor to limit the rotational movement range of the rotor.
It is provided with a cover having a pair of protrusions.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is
A cylindrical case having a bottom, a resistor having a resistance pattern provided on a side surface of an inner wall of the case, a connector terminal for external connection electrically connected to the resistor, and a resistance pattern of the resistor. A supporting arm for supporting a brush that is in sliding contact with the rotor is provided so as to be rotatable in sliding contact with the bottom surface of the inner wall of the case, and the rotor is arranged on the outer circumference of the rotor and one end of which is locked to the case and the other. A support spring for the rotor, which has a coil spring whose end is locked to the support arm of the rotor and which constantly applies a biasing force to the rotor in the returning direction, and a recess which is engaged with a hook provided at the open end of the case. A cover having a pair of projections that abut on a rotation restricting portion provided on the upper end of the cover to limit the rotational movement range of the rotor, one end of the coil spring being locked to the support arm, and Pair of The cover is pivoted from a first position where the concave portion of the cover is not engaged with the hook to a second position where the concave portion of the cover is engaged with the hook, the first position facing the rotation restricting portion on one side. By attaching the cover to the case, a biasing force is applied to the coil spring.

[0010] The invention described in claim 2 is the same as the claim 1.
In the invention described above, the cover is provided with a hole indicating a position where one end of the coil spring is locked to the support arm when the cover is in the first position.

The invention described in claim 3 is the same as the claim 2
In the invention described in (1) above, a pair of holes are provided at positions symmetrical about the rotor.

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

FIG. 1 is an exploded perspective view of a rotary throttle position sensor according to an embodiment of the present invention, FIG. 2 is a top view with the cover, which is the main part, removed, FIG. 3 is the same sectional view, and FIG. FIG. 5 is a rear view of the cover, which is the main part, and FIG. 5 is a developed view of the resistor, which is the main part.

In the figure, reference numeral 11 denotes a bottomed cylindrical case molded from a synthetic resin having excellent heat resistance and mechanical strength, such as polybutylene terephthalate mixed with glass fiber. Is provided with a guide portion 11a composed of a cylindrical protrusion. Further, several connector terminals 12 for external connection are incorporated in the case 11 by insert molding. One end of the connector terminal 12 is exposed inside the case 11, and the other end is the outer peripheral surface of the case 11. It projects into a part of the connector portion 13 provided so as to project outward. Further, a ring-shaped flange 14 is formed on the outer peripheral surface of the case 11, and mounting portions 16 having mounting holes 15 are provided at positions facing each other on a part of the flange 14. Further, a step portion 17 is provided in the middle portion of the inner peripheral wall of the case 11.

In such a case, several resistance patterns 19 are provided on one surface of a resin film 18 such as a polyimide film, and the connector terminal 1 is provided on the other end of the resistance patterns 19.
A resistor 21 in which a connecting portion 20 for contacting the second member 2 and being electrically connected is formed by printing or the like is incorporated. That is, the resistor 21 is installed along the inner peripheral wall of the case 11 so that the vertical position of the resistor 21 is regulated by the step 17 so that the resistance pattern 19 is inside. One end of the resistor 21 is inside the case 11 of the connector terminal 12. It is installed so as to be located in the part exposed to.

The connecting portion 20 of the resistor 21 is connected to the connector terminal 12 by a U-shaped bent metal plate having elasticity such as stainless steel. One side is a flat plate and the other side is a pressing spring. By incorporating 22 into the connector terminal 20, the connection portion 20 is pressed against the exposed portion of the connector terminal 12.

A cylindrical rotor 23 made of synthetic resin such as polybutylene terephthalate mixed with glass fibers is incorporated in the case 11. The rotor 23 is provided with a support arm 24 projecting outward at an intermediate portion of an outer peripheral surface, and a tip of the support arm 24 is brought into contact with the resistance pattern 19 of the resistor 21 and slid by the rotation of the rotor 23. 25
Is installed. The support arm 24 of the rotor 23 is formed with a rotation restricting portion 26 that restricts the rotation range of the rotor itself. The rotor 23 has a thick inner wall on the side facing the portion where the support arm 24 is provided. In other words, the fitting hole 27 that is formed by cutting a part of a circle is formed in the center of the rotor 23, and the wall thickness is formed from the upper end to the lower part of the intermediate portion, and the portion below that is the case 1
A center hole 28 of a perfect circle that is fitted into and supported by the first guide portion 11a is formed.

A coil spring 34 is provided on the outer circumference of the rotor 23. The coil spring 34
Has one end 34a hooked on a hook 35 provided on the bottom surface of the inner wall of the case 11, and the other end 34b is engaged with a recessed groove 36 provided on the support arm 24 of the rotor 23. It gives power.

Further, a cover 29 made of the same material as the case 11 is attached to the opening of the case 11 in which the resistor 21, the pressing spring 22, the rotor 23 and the coil spring 34 are incorporated. This cover 2
An opening 31 through which the rotary throttle shaft 30 is inserted is provided in the central portion of the rotor 9, and it contacts the rotation restricting portion 26 of the rotor 23 to limit the left and right rotational movements of the rotor. Pair of protrusions 32, 33
have. Further, the cover 29 has recesses 39, 40 which engage with hooks 37, 38 provided in the opening of the case 11 at line symmetrical positions about the rotor and differ from these recesses 39, 40 by 90 degrees. , And have holes 41 and 42 at line-symmetrical positions around the rotor.

Next, the rotary throttle position sensor having the above structure will be described according to the assembling procedure. FIG. 6 is an assembly diagram of the rotary throttle position sensor according to the present embodiment. As shown in FIG. 6A, the coil spring 34 is inserted through the opening of the case 11 in which the resistor 21 and the presser spring 22 are incorporated. , One end 34a thereof is hooked on the hook 35 provided on the case 11. Next, as shown in FIG. 6B, the rotor 23 is inserted into the inner peripheral position of the coil spring 34, and the center hole 28 of the rotor 23 is fitted into the guide portion 11 a provided on the bottom surface of the case 11 to remove the rotor 23. Support arm 2
The other end 34 of the coil spring 34 in the groove 36 provided in
hook b. At this time, the coil spring 34 has not yet accumulated the urging force. Next, as shown in FIG. 6C, the cover 29 is attached so as to close the opening of the case 11, but the hook 37 provided on the case 11 is located on the line segment connecting the holes 41 and 42 provided in the cover 29. , 38 are positioned so that the support arm 24 of the rotor 23 is located inside the pair of protrusions 32, 33 provided on the cover 29.
The rotation regulating portion 26 provided in the
Reference numerals 1 and 42 function as alignment marks when the cover 29 is assembled into the case 11. Next, in the state of FIG. 6C, the holes 41 and 42 of the cover 29 are chucked and the cover 29 is rotated leftward so that the recesses 39 and 40 of the cover 29 are moved to the case 11 as shown in FIG. 6D. Hook 37,3
8 and then the outer periphery of the cover 29 is heat-welded and attached to the case 11. In this state, coil spring 3
Since 4 is pulled leftward while being hooked on the support arm 24 of the rotor 23, an urging force that constantly urges the rotor 23 in the returning direction is accumulated, and the initial rotation position of the rotor 23 is determined.

The rotary throttle position sensor thus constructed is preassembled, and is press-fitted while being aligned with the rotary throttle shaft 30 near the internal combustion engine, and the rotor 23 is attached to the rotary throttle shaft 30.
Mounting portion 16 of the case 11 in a state in which the
The case 11 is fixed to the throttle body (not shown) by using to complete the assembling.

That is, by pushing the casing 11 together with the flat portion of the rotary throttle shaft 30 and the thick portion of the rotor 23 toward the rotary throttle shaft 30 side, the rotor 23 is attached to the tip of the rotary throttle shaft 30. Will be fitted and joined in the rotational direction, and in that state, using a screw or the like, the mounting portion 16 of the case 11
The case 11 is fixed to the throttle body by using the mounting hole 15 of.

The rotary throttle shaft 30 is now
The accelerator 23 rotates by stepping on or off the accelerator, the rotor 23 rotates in synchronization with the rotation, and the brush 25 attached to the rotor 23 causes the resistance pattern 1 of the resistor 21.
The contact position with 9 is changed, and the connector terminal 12
The voltage corresponding to the contact position is obtained, and the amount of fuel injected into the engine can be controlled by using the fluctuation of the voltage as a signal.

When assembled as described above, the rotor 23 is the case 1
1, the center hole 28 of a perfect circle is fitted into the guide portion 11a for positioning, and the rotor 23 itself can be press-fitted to the rotary throttle shaft 30 with its center axis aligned.
Assembling can be performed correctly, and it is possible to prevent the rotor 23 from being damaged when assembled, and the rotor 23 from being tilted with respect to the case 11 and being excessively pressed against the resistor 21 of the case 11 to be deformed. Become. In addition, even if the rotor 23 rotates when the rotary throttle position sensor is actually used, the pair of protrusions 3 provided on the cover 29 is provided.
The rotors 2 and 33 limit the rotor 23, and the excessive rotation of the rotor 23 can be prevented.

The resin film 18 is used as the resistor 21.
Although the resistance pattern 19 is formed on the inner surface of the case 11, the same effect can be obtained by directly forming the resistance pattern 19 on the inner wall surface of the case 11.

[0026]

As described above, the present invention utilizes the structure in which the rotation restricting portion of the rotor and the first and second protrusions of the cover come into contact with each other to restrict the rotation of the rotor. By accumulating the charge, the initial rotation position of the rotor can be secured by the biasing force of the coil spring. As a result, it is possible to suppress the generation of the contact powder to a small extent because the configuration of determining the initial position of the rotor by the pair of arms is uncertain, so that the contact powder scattered on the resistor is small and an accurate signal can be obtained. It is possible to realize a highly reliable rotary throttle position sensor.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a rotary throttle position sensor according to an embodiment of the present invention.

FIG. 2 is a top view of the main part with a cover removed.

FIG. 3 is a sectional view of the same.

FIG. 4 is a rear view of the cover, which is the main part of the same.

FIG. 5 is a development view of a resistor, which is a main part of the same.

FIG. 6 is a top view for explaining an assembly procedure of the rotary throttle position sensor.

FIG. 7 is a top view with the cover removed to reveal the internal components of a conventional rotary throttle position sensor.

FIG. 8 is a sectional view of the same.

[Explanation of symbols]

 11 Case 12 Connector Terminal 19 Resistance Pattern 21 Resistor 23 Rotor 24 Support Arm 25 Brush 26 Rotation Restriction Part 29 Cover 32, 33 Projection 34 Coil Spring 37, 38 Hook 39, 40 Recess 41, 42 Hole

Claims (3)

[Claims] 1. A bottomed cylindrical case, a resistor having a resistance pattern provided on a side surface of an inner wall of the case, a connector terminal for external connection electrically connected to the resistor, and A support arm that supports a brush that is in sliding contact with the resistance pattern of the resistor is provided in a protruding manner. The rotor is slidably in contact with the bottom surface of the inner wall of the case and is rotatable. And has a coil spring whose other end is locked to the support arm of the rotor and which always applies a biasing force to the rotor in the return direction, and a recess engaged with a hook provided at the opening end of the case. A cover having a pair of protrusions that abut against a rotation restricting portion provided on the support arm of the rotor to limit the rotational movement range of the rotor, and one end of the coil spring is locked to the support arm. And the above The cover is moved from a first position where the concave portion of the cover is not engaged with the hook to the second position where the concave portion of the cover is opposed to the rotation restricting portion to one of the pair of protrusions of the bar. A rotary throttle position sensor, which is configured to rotate and attach the cover to the case so as to apply an urging force to the coil spring. 2. The rotary throttle position sensor according to claim 1, wherein the cover is provided with a hole indicating a position where one end of the coil spring is locked to the support arm when the cover is in the first position. 3. The rotary throttle position sensor according to claim 2, wherein a pair of holes are provided at positions symmetrical with respect to the rotor.