JP2000320350A - Airflow control system of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an airflow control system of internal combustion engines that can reduce in the number of part items assembly man-hours and manufactur ing cost. SOLUTION: This airflow control system of internal combustion engines comprises an intake pipe 1 of synthetic resin, a throttle valve stem 3 rotatably supported via a bearing part 2 orthogonally to the axis of the intake pipe 1, a throttle valve element 4 fixed to the throttle valve stem 3, so as to regulate the air weight flow through the intake pipe 1 according to the rotation of the throttle valve stem 3, a retainer part 11 seated in a circumferential groove 3a cut in the end of the throttle valve stem 3 so as to check the axial movement of the throttle valve stem 3, and a potentiometer 12 for detecting the ratio of opening of the throttle valve element 4. A casing 14 of the potentiometer 12 and the retainer part 11 are made up of an integral casing body 10 of resin, which is fixed to the intake pipe 1 via a weld part 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow control device for an internal combustion engine having a throttle valve for adjusting an air flow rate flowing through an intake pipe by rotating a throttle valve shaft rotatably supported by the intake pipe. is there.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view of a conventional air flow control device for an internal combustion engine. This air flow control device for an internal combustion engine is an intake pipe 1 in which a polyamide resin contains glass fiber.
And a throttle valve shaft 3 orthogonal to the axial direction of the intake pipe 1 and rotatably supported via a bearing 2.
A throttle valve 4 fixed to the throttle valve shaft 3 and adjusting the flow rate of air flowing through the intake pipe 1 by rotation of the throttle valve shaft 3;
A retainer 5 fitted in a concave portion 1a of the intake pipe 1 while being locked by a groove 3a formed along the circumferential direction at the end of the intake pipe 1 to prevent the throttle valve shaft 3 from moving in the direction of arrow A; A potentiometer 6 serving as a sensor for pressing the retainer 5 and detecting the opening of the throttle valve 4, a screw (not shown) for fixing the potentiometer 6 to the intake pipe 1, and the throttle valve shaft 3 in the direction of arrow A The torsion spring 7 is urged in the direction in which the throttle valve 4 is closed.

[0003] The retainer 5 is made of a polyamide resin containing glass fiber. This retainer 5 is shown in FIG.
As shown in the figure, the large diameter portion 5a larger than the outer diameter of the throttle valve shaft 3 and the small diameter portion 5b smaller than the outer diameter of the throttle valve shaft 3 and larger than the bottom outer diameter of the groove 3a are provided.

In this retainer 5, first, the throttle valve shaft 3 is inserted into the large diameter portion 5a of the retainer 5, and then the retainer 5 is moved in the radial direction on the groove 3a to lock the small diameter portion 5b into the groove 3a. Then, the retainer 5 is inserted into the recess 1a by the potentiometer 6
, And finally the potentiometer 6 is turned on.
Is fixed to the intake pipe 1 by using screws.

In this air flow control device for an internal combustion engine, the rotation of a throttle valve shaft 3 rotatably supported by an intake pipe 1 causes
The opening degree of the throttle valve 4 in the intake pipe 1 is changed to adjust the amount of air flowing through the intake pipe 1. The degree of opening of the throttle valve 4 is detected by a potentiometer 6. That is, although not shown, the brush fixed to the end of the throttle valve shaft 3 and pressing the resistor of the potentiometer 12 slides and moves on the resistor with the rotation of the throttle valve shaft 3, and the position of the brush moves. It is output as a voltage signal, and the opening degree of the throttle valve 4 is detected. The axial movement of the throttle valve shaft 3 changes the pressing force of the brush against the resistor,
When the pressing load is small, the voltage signal is not accurately detected. On the other hand, when the pressing load is too large, wear of the resistor and the brush occurs, resulting in a problem of durability. To prevent these problems, the retainer 5 prevents the throttle valve shaft 3 from moving in the axial direction.

[0006]

In the conventional air flow control device for an internal combustion engine, the retainer 5 and the potentiometer 6 are formed as separate members, and the number of parts is large.
There are problems that the number of assembling steps is large and the manufacturing cost is increased.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and an internal combustion engine capable of reducing the number of parts and the number of assembling steps and reducing the manufacturing cost. An object is to obtain an air flow control device.

[0008]

According to a first aspect of the present invention, there is provided an air flow control device for an internal combustion engine, comprising: an intake pipe made of a synthetic resin; A throttle valve shaft rotatably supported via a throttle valve, a throttle valve fixed to the throttle valve shaft to adjust the amount of air flowing through the intake pipe by rotation of the throttle valve shaft, and a circumferential direction at an end of the throttle valve shaft. A retainer that is locked in a groove formed along the axis and prevents the throttle valve shaft from moving in the axial direction, and a sensor that detects the degree of opening of the throttle valve, and the case of the sensor and the retainer It is composed of a case body integrated with resin,
The case body is fixed to the intake pipe by fixing means.

In the air flow control device for an internal combustion engine according to a second aspect of the present invention, the fixing means is a screw.

In the air flow control device for an internal combustion engine according to claim 3 of the present invention, the fixing means is resin welding.

In the air flow control device for an internal combustion engine according to a fourth aspect of the present invention, the sensor is a potentiometer.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a sectional view of an air flow control device for an internal combustion engine according to Embodiment 1 of the present invention. The air flow control device for an internal combustion engine includes an intake pipe 1 in which a polyamide resin contains glass fiber, and a bearing section 2 which is orthogonal to an axial direction of the intake pipe 1 and has a bearing portion 2.
A throttle valve shaft 3 rotatably supported via a throttle valve, a throttle valve 4 fixed to the throttle valve shaft 3, and adjusting the amount of air flowing through the intake pipe 1 by rotation of the throttle valve shaft 3. Case body 10 fixed at welding portion 13 by resin welding as fixing means
Urges the throttle valve shaft 3 in the direction of arrow B and
And a torsion spring 7 biased in the closing direction. The case body 10 includes a retainer portion 11 which is locked in a groove 3a formed in the end of the throttle valve shaft 3 along the circumferential direction and prevents the throttle valve shaft 3 from moving in the direction of arrow B; Case 1 of Potentiometer 12 as Sensor for Detecting Opening
4 are integrally formed with a polyamide resin.

As shown in FIG. 3, the retainer portion 11 has a large diameter portion larger than the outer diameter of the throttle valve shaft 3 and a small diameter portion smaller than the outer diameter of the throttle valve shaft 3 and larger than the bottom outer diameter of the groove portion. have. The case main body 10 inserts the throttle valve shaft 3 into the large-diameter portion of the retainer portion 11, then moves the retainer portion 11 in the radial direction on the groove portion 3a to lock the small-diameter portion in the groove portion 3a,
Next, the retainer 11 is pressed against the concave portion 1 a of the intake pipe 1, and finally, the case body 10 is fixed to the intake pipe 1 by a welding portion 13 by resin welding, whereby the case body 10 is attached to the intake pipe 1. The fixing of the case body 10 means that the potentiometer 12 is fixed to the intake pipe 1 as it is.

In this air flow control device for an internal combustion engine, the rotation of the throttle valve shaft 3 rotatably supported by the intake pipe 1 causes
The opening degree of the throttle valve 4 in the intake pipe 1 is changed to adjust the amount of air flowing through the intake pipe 1.

Embodiment 2 In the first embodiment, the case main body 10 is fixed to the intake pipe 1 by resin welding, specifically, by heating or ultrasonic treatment. However, the case main body 10 may be fixed to the intake pipe using screws as fixing means. Good.

[0016]

As described above, according to the air flow control device for an internal combustion engine according to the first aspect of the present invention, the intake pipe made of synthetic resin is perpendicular to the axial direction of the intake pipe. A throttle valve shaft rotatably supported via a bearing portion, a throttle valve fixed to the throttle valve shaft, and adjusting a flow rate of air flowing through the intake pipe by rotation of the throttle valve shaft; and an end of the throttle valve shaft. A retainer portion locked in a groove formed in the portion along the circumferential direction to prevent the throttle valve shaft from moving in the axial direction; and a sensor for detecting the degree of opening of the throttle valve. And the retainer part are constituted by a case body integrated with resin, and the case body is fixed to the intake pipe by fixing means, so that the number of parts and the number of assembly steps can be reduced, and Cost can be reduced.

According to the air flow control device for an internal combustion engine according to the second aspect, since the fixing means is a screw, the case body can be fixed to the intake pipe with a low cost and a simple configuration.

Further, according to the air flow control device for an internal combustion engine according to the third aspect, since the fixing means is resin welding, the case main body can be easily and firmly fixed to the intake pipe, and Airtightness between the main body and the intake pipe is ensured, and there is no need to provide an O-ring for airtightness.

Further, according to the air flow control device for an internal combustion engine according to claim 4, the sensor is a potentiometer,
The opening degree of the throttle valve can be easily and accurately detected.

[Brief description of the drawings]

FIG. 1 is a sectional view of an air flow control device for an internal combustion engine according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view of a conventional air flow control device for an internal combustion engine.

FIG. 3 is a front view of the retainer of FIG. 2;

[Explanation of symbols]

1 intake pipe, 2 bearing, 3 throttle valve shaft, 3a groove,
4 Throttle valve, 10 case body, 11 retainer, 1
2. Potentiometer. 13 welds, 14 cases.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takeshi Sugiyama 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) in Mitsubishi Electric Corporation 3G065 CA00 CA23 HA21 HA22

Claims (4)

[Claims] An intake pipe made of a synthetic resin, a throttle valve axis orthogonal to the axial direction of the intake pipe and rotatably supported via a bearing, and fixed to the throttle valve axis. A throttle valve that adjusts the flow rate of air flowing through the intake pipe by rotation of the throttle valve shaft; and a throttle valve that is locked in a groove formed along the circumferential direction at an end of the throttle valve shaft and moves in the axial direction. And a sensor for detecting the degree of opening of the throttle valve. The case of the sensor and the retainer are formed of a case body integrated with a resin, and the case body is provided with the intake air. An air flow control device for an internal combustion engine fixed to a pipe by a fixing means. 2. The air flow control device for an internal combustion engine according to claim 1, wherein the fixing means is a screw. 3. The air flow control device for an internal combustion engine according to claim 1, wherein the fixing means is resin welding. 4. The air flow control device for an internal combustion engine according to claim 1, wherein the sensor is a potentiometer.