JPH08145617A - Throttle valve opening sensor - Google Patents

Abstract

PURPOSE: To provide a throttle valve opening sensor which can be operated well for a long term by preventing intrusion of moisture or foreign matter into the housing. CONSTITUTION: The throttle valve opening sensor comprises a housing 1 in which a rotor 5, rotatable in response to the opening/closing of a throttle valve 24, is disposed and a board 2 having a resistor pattern 3 is secured. A slider 7 fixed to the rotor 5 slides on the resistor pattern 3 for detecting the opening of the throttle valve. The housing 1 is molded from a synthetic resin integrally with the throttle body 20 and the resistor pattern 3 on the substrate 2 is disposed oppositely to the opposite side of the throttle valve.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, a throttle valve opening sensor, which detects the opening of a throttle valve of an internal combustion engine and outputs a detection signal corresponding to the opening, generally has a shaft portion rotatable in the center of a housing. While supporting the shaft and fixing the rotor with the slider to the inner tip of the shaft, fix the substrate on which the resistor pattern is formed in the housing, and bring the rotor slider into contact with the resistor pattern. Composed.

In such a throttle valve opening sensor, as shown in FIG. 4, the housing 30 is fitted to a mounting portion formed on a side portion of the throttle body 35, and the end portion of the shaft portion 31 is formed. On throttle shaft 3
The front end of 6 was engaged and connected, and it was attached to a fixed position of the throttle valve device by a plurality of attachment screws.

[0004]

However, the housing 30 of the throttle valve opening sensor and the mounting portion of the throttle body 35 are assembled so as to be hermetically sealed with a sealing member made of an annular rubber therebetween. When the sealing material deteriorates due to vibration or heat of the internal combustion engine, the sealing property of the joint deteriorates and a gap is created, from which water enters the sensor and adversely affects the sliding contact of the sensor. There was a problem.

The substrate 32 mounted in the housing 30 may be arranged with its resistor pattern facing the throttle valve. However, in an internal combustion engine provided with a blow-by gas reducing device, the substrate 32 is disposed around the shaft. The blow-by gas penetrates into the housing through a slight gap, soot and the like are likely to adhere to the surface of the resistor pattern, and the soot and the like cause an error in the sensor output.

The present invention has been made in view of the above points, and provides a throttle valve opening sensor capable of preventing moisture and foreign matter from entering the housing and operating the sensor satisfactorily for a long period of time. The purpose is to

[0007]

In order to achieve the above object, a throttle valve opening sensor according to the present invention is provided with a rotor that rotates in response to opening and closing of a throttle valve in the housing, and a rotor in the housing. In the throttle valve opening sensor that detects the opening of the throttle valve by contacting the slider attached to the rotor with the resistor pattern, the substrate with the resistor pattern is fixed to It is characterized in that it is integrally formed and the resistor pattern of the substrate is arranged toward the side opposite to the throttle valve.

[0008]

In the throttle valve opening sensor having such a structure, the rotor is rotated by the rotation of the throttle valve and the throttle shaft, and the resistor pattern on the substrate of the slider attached to the rotor is formed. By changing the contact position and changing the resistance value between them, a detection signal indicating the opening of the throttle valve is output, but since the housing of the sensor is molded integrally with the throttle body, as in the conventional case, As compared with the case where the separately molded housing is fixed to the side portion of the throttle body with the mounting screw, the joint portion between the housing and the throttle body can be eliminated.

For this reason, the sealing material conventionally inserted in the joint between the housing of the sensor and the throttle body is no longer required, and the generation of gaps due to the deterioration of the sealing material due to vibration and heat of the internal combustion engine is eliminated, resulting in long-term In addition, it is possible to prevent moisture and dust from entering the sensor and operate the sensor satisfactorily.

Further, since the resistor pattern of the substrate is arranged toward the anti-throttle valve side, even if the blow-by gas intrudes into the housing in an internal combustion engine provided with a blow-by gas reducing device, the resistor is Soot and the like are less likely to adhere to the surface of the pattern, and malfunction of the sensor due to the adhesion of soot and the like can be prevented.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of the throttle valve opening sensor with a cover 8 removed, and FIG. 2 is an enlarged sectional view taken along line II-II. Reference numeral 1 is a housing of the sensor, and the housing 1 is, as shown in the overall sectional view of FIG.
It is molded of synthetic resin integrally with the throttle body 20.
As the synthetic resin, for example, PPS resin (polyphenylene sulfite) having good heat resistance and insulating properties is used. That is, the throttle body 20 is integrally formed with the throttle body 20 such that the housing 1 of the sensor is provided on the outside of the bearing portion that supports one side of the throttle shaft 21 of the throttle body 20.

The housing 1 is formed in a substantially circular shape when viewed from the front, and a connector receiving portion 1a to which a connector (not shown) is connected is integrally formed on the upper portion thereof. A substrate 2 is fixed in the housing 1. The substrate 2 is formed of a ceramic plate or the like, and the resistor pattern 3 is printed on its front surface in a substantially arc shape.

The resistor pattern 3 is formed by, for example, printing a resistance ink in which carbon and resin are mixed on a substrate and firing the ink, and has a predetermined electric resistance per unit area.
The connection terminal wire 4 is connected to each end of the resistor pattern 3 through the through hole, and the other end of the connection terminal wire 4 is led out into the connector receiving portion 1a. The substrate 2 is arranged with the resistor pattern 3 facing outward, that is, toward the side opposite to the throttle valve.

A hole is formed in the center of the substrate 2, the tip of the throttle shaft 21 is rotatably inserted in the hole, and the rotor 5 is fixed to the tip by a mounting screw 6. The rotor 5 is molded of synthetic resin into a predetermined shape,
The slider 7 is attached to the tip thereof. The tip of the throttle shaft 21 is cut into, for example, a D shape, and the rotor 5 having a hole corresponding to the shape is fixed to the shaft 21 at a constant angle.

The slider 7 is formed by bending a metal plate having spring elasticity, and is attached to two tips of the metal plate, for example, Ag-P.
The sliding ends 7a and 7b made of d alloy are formed by welding. The sliding ends 7a and 7b of the slider 7 are arranged so as to be in contact with the resistor pattern 3 on the substrate. Therefore, the rotor 5 and the slider 7 rotate together with the throttle shaft 21, and the sliding ends 7a and 7b of the slider 7 slide on the resistor pattern 3 on the substrate.

Further, a circular cover 8 is fitted into the circular opening on the front side of the housing 1 with an annular sealing material (rubber packing) 9 fitted inside, and the inside of the housing 1 is hermetically sealed. To be done.

On the other hand, a metal bearing 22 is fitted inside the sensor side of the throttle body 20, and a ball bearing 23 is fitted inside the opposite side of the throttle body 20.
1 is rotatably supported by a metal bearing 22 and a ball bearing 23.

Further, a throttle valve 24 is attached to the central portion of the throttle shaft 21 in the throttle body 20 so that the passage can be opened and closed, and an accelerator wire is fixed to the tip portion of the throttle shaft 21 protruding from the side opposite to the sensor. An accelerator lever 25 for mounting is attached.

The accelerator lever 25 is insert-molded with a synthetic resin using a metal stopper 25a bent in a substantially L shape as an insert, and a spring receiving portion 25b for receiving the throttle return coil springs 26 and 27 is formed inside. It A spring receiving portion 28 is fixed to the end of the throttle body 20 facing the spring receiving portion 25b, and throttle return coil springs 26 and 27 are provided.
It is held between 5a. The accelerator lever 25 is fixed to the tip of the throttle shaft 21 by a nut 29.

In the thus constructed throttle valve device, when the accelerator lever 25 receives a rotational force by an accelerator wire (not shown), the throttle shaft 21 is rotated against the urging force of the coil springs 26 and 27, and the throttle valve is rotated. The valve 24 is opened.

At this time, the rotation of the throttle shaft 21 causes the rotor 5 fixed to the tip on the sensor side to rotate,
Sliding end 7 at the tip of the slider 7 attached to the rotor 5
a and 7b slide on the resistor pattern 3 on the substrate 2.

A current is supplied to the resistor pattern 3 through the connection terminal wire 4 to form a kind of potentiometer circuit, and the contact position of the sliding ends 7a and 7b of the slider 7 is the rotation angle of the throttle shaft 21, That is, the detection signal indicating the opening degree of the throttle valve is obtained from the connection terminal portion 4 of the sensor by changing according to the opening degree of the throttle valve 24.

As described above, since the housing 1 of this throttle valve opening sensor is molded integrally with the throttle body 20, a separately molded housing is attached to the side of the throttle body as in the conventional case. It is possible to eliminate the joint portion between the housing and the throttle body, as compared with the case where they are fixed by.

For this reason, the sealing material conventionally inserted in the joint between the housing of the sensor and the throttle body is no longer required, and the generation of gaps due to the deterioration of the sealing material due to vibration and heat of the internal combustion engine is eliminated, resulting in long-term In addition, it is possible to prevent moisture and dust from entering the sensor and operate the sensor satisfactorily. Further, it is possible to simplify the work process when assembling the sensor and reduce the number of parts.

Further, since the resistor pattern 3 of the substrate 2 is arranged toward the anti-throttle valve side, even if blow-by gas enters the housing 1 in an internal combustion engine provided with a blow-by gas reducing device. Soot and the like are less likely to adhere to the surface of the resistor pattern 3, and malfunction of the sensor due to the adhesion of soot and the like can be prevented.

[Brief description of drawings]

FIG. 1 is a front view of a throttle valve opening sensor according to an embodiment of the present invention with a cover removed.

FIG. 2 is an enlarged sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view of the entire throttle valve device provided with a sensor.

FIG. 4 is a sectional view of a conventional throttle valve opening sensor.

[Explanation of symbols]

 1-housing, 2-substrate, 3-resistor pattern, 5-rotor, 7-slider, 20-throttle body.

Claims (1)

[Claims] 1. A rotor that rotates in response to opening and closing of a throttle valve is provided in a housing, a substrate having a resistor pattern is fixed in the housing, and a slider attached to the rotor is provided. In a throttle valve opening sensor for detecting the opening of the throttle valve by contacting it on a resistor pattern, the housing is integrally molded with a throttle body by a synthetic resin, and the resistor pattern of the substrate is on the side opposite to the throttle valve. A throttle valve opening sensor characterized in that it is arranged toward.