JPH08218903A - Intake air quantity control device for internal combustion engine - Google Patents

Abstract

PURPOSE: To improve the angle accuracy of a throttle valve without changing angle accuracy of a motor by forming a radius, which connects abutment points of abutment members and a shaft center point of an output shaft of a motor, smaller than the radius, which connects the abutment points of the abutment members and a shaft center point of a throttle valve shaft. CONSTITUTION: A motor lever 9 and a throttle valve lever 5 are made to directly abut on each other with abutment members T1, T2, and a line E1-E2 passes the center of an intake air passage 2 and connects the shaft center point A of the longitudinal core of a throttle valve shaft 3 crossing an intake air passage 2 and the abutment points of the abutment members T1, T2, and a line F1-F2 passes the shaft center point A and crosses the line E1-E2, and a shaft center point C is eccentrically arranged between the line E1-A-F1 formed in the open operation side G of a throttle valve 4, and the longitudinal core of the throttle valve shaft 3 and the longitudinal core of the output shaft 8A of the motor are eccentrically arranged in parallel with each other. Angle accuracy of the throttle valve can be thereby changed without changing angle accuracy of the motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air amount control device for controlling an intake air amount supplied to a combustion chamber of an internal combustion engine by means of a throttle valve arranged in an intake passage of a throttle body. In particular, the present invention relates to a throttle valve that controls the intake air amount operated by an electrically driven motor.

[0002]

2. Description of the Related Art A conventional intake air amount control system for an internal combustion engine will be described with reference to FIGS. FIG. 9 is a longitudinal sectional view of a main part of a conventional intake air amount control apparatus for an internal combustion engine, FIG.
Reference numeral 0 is a system diagram showing a state in which the intake air amount control device shown in FIG. 9 is assembled to an internal combustion engine. Reference numeral 20 denotes a throttle body having an intake passage 21 penetrating therethrough,
A throttle valve shaft 22 is disposed across the center of the intake passage 21, and both ends of the throttle valve shaft 22 are rotatably supported by the throttle body 20. A throttle valve 23 opens and closes the intake passage 21 and is attached to the throttle valve shaft 22. That is, when the throttle valve shaft 22 rotates, the intake passage 21
Is controlled by the throttle valve 23. Reference numeral 24 denotes a motor arranged on the right end 20A of the throttle body 20. The rotation of the motor 24 depends on the output shaft 2 of the motor 24.
4A, from the motor lever 24B attached to the output shaft 24A, is given to the throttle valve lever 23A arranged at the right end of the throttle valve shaft 22 via the transmission means 25. And throttle valve shaft 2
2 longitudinal axis XX and the output shaft 24A of the motor 24
Are arranged concentrically with the longitudinal axis Y-Y. On the other hand, on the left end 20B of the throttle body 20, a monitoring throttle valve opening sensor 25 is arranged.
The rotation of the throttle valve shaft 22 is applied to the monitoring throttle valve opening sensor 25 via the second throttle valve lever 23B and the transmission means 26. The monitoring throttle valve opening sensor 25 detects the opening position state and acceleration / deceleration state of the throttle valve 23 driven by the motor 24, and outputs an electric signal to an electronic control unit described later. Valve 2
3 confirms whether or not the motor 24 operates normally.

Then, an electric signal is input to the motor 24 as follows, and the motor 24 is rotationally driven. Reference numeral 27 denotes an accelerator pedal (or an accelerator grip) which is operated by the driver's will. The operation amount of the accelerator pedal 27 is an accelerator pedal sensor 29 (this is an angle sensor, A stroke sensor or the like) is mechanically input, the operation amount is converted into an electric signal by an accelerator pedal sensor 29, and the electric signal is output to an electronic control unit 30 (hereinafter referred to as ECU). When an electric signal from the accelerator pedal sensor 29 is input to the ECU 30, the digital signal directly passes through the input circuit and the analog signal is digitally converted by the A / D converter and then input to the microcomputer. It
Then, the microcomputer arithmetically processes the input signal and outputs an electric signal corresponding to the operation of the accelerator pedal 27 to the motor 24 through the output circuit.

According to the above, the motor 24 imparts the rotation corresponding to the operation of the accelerator pedal 29 to the throttle valve lever 23A via the output shaft 24A, the motor lever 24B and the transmission means 25. It is possible to obtain the throttle valve opening degree according to the operation of the accelerator pedal 29, and the air controlled by the throttle valve 23 is supplied into the combustion chamber of the internal combustion engine via the intake pipe described later. The above-described monitoring throttle valve opening sensor 25 monitors that the motor 24 is normally driven to rotate by an electric signal output from the ECU 30, and the throttle valve shaft 22 and the throttle valve 23 are normally operated (rotated). Play a role.

The throttle body 20 including these motors 24 is incorporated in the internal combustion engine as follows. FIG.
Describing with 0, 31 is an internal combustion engine, and the cylinder head 3 connected to the upper surface of the cylinder block 32.
3, an intake port 35 communicating with the combustion chamber 34 and an exhaust port 36 are bored, and an intake pipe 35 having a fuel injection valve 37 is connected to the intake port 35 opening to the side surface of the cylinder head 33. . A throttle body 20 equipped with a motor 24 is connected upstream of the intake pipe 38, and an air cleaner 39 is further provided upstream of the throttle body 20.
Is connected. Therefore, the amount of the air flowing in from the air cleaner 39 is controlled by the throttle valve 23, and the intake pipe 38,
It is supplied into the combustion chamber 34 through the intake port 35. On the other hand, the fuel in the fuel tank 40 is pressurized by the fuel pump 41 and supplied to the fuel injection valve 37 through the fuel distribution pipe 42. The fuel injection valve 37 is injected by the valve opening signal from the ECU 30. By opening the holes, the desired fuel under pressure is injected and supplied into the combustion chamber 34 through the intake pipe 38 and the intake port 35.

[0006]

The conventional intake air amount control system for an internal combustion engine has the following problems.
The throttle valve 23 and the motor 24 synchronously rotate via the transmission means 25 to perform a one-to-one angle control, and the angular accuracy of the throttle valve 23 depends on the angular accuracy of the motor 24. . That is, the angular accuracy of the motor 24 and the throttle valve 2
The angle accuracy of 3 is equal. Here, when the angular accuracy required for the throttle valve 23 becomes severe, it is necessary to improve the angular accuracy of the motor 23, which makes it difficult to manufacture the motor and significantly increases the manufacturing cost. Is not preferable. In addition, the rotation of the motor 24
Although it is considered to reduce the rate of change of the throttle valve operating angle by transmitting the change to the throttle valve 23 by using a linkage, such a structure complicates the manufacturing cost and further causes backlash due to backlash. It is not preferable because it may occur, abnormal noise may be generated at the meshing portion, or wear may occur during long-term use.

The present invention has been made in view of the above problems, and its main object is to improve the angular accuracy of the throttle valve without changing the angular accuracy of the motor.

[0008]

[Means for Solving the Problems] In order to achieve the above object,
According to the present invention, an intake passage passing through the throttle body is controlled to be opened and closed by a throttle valve attached to a throttle valve shaft rotatably supported by the throttle body, and an electronic control unit outputs the throttle valve shaft to the throttle valve shaft. A motor that applies a rotational force to the throttle valve shaft in accordance with an electric signal is arranged,
In an internal combustion engine in which the rotation of a motor lever attached to an output shaft of a motor is transmitted to a throttle valve lever arranged at an end portion of the throttle valve shaft via a transmission means to impart rotation of the motor to the throttle valve shaft. In the intake air amount control device, the motor lever and the throttle valve lever are directly brought into contact with each other by an abutment member, and the axial center of the longitudinal axis of the throttle valve shaft passing through the center of the intake passage and traversing the intake passage. The output shaft of the motor between the line connecting the point and the contact point of the contact member and the line passing through the axial center point and orthogonal to the line and formed on the opening operation side of the throttle valve. The eccentricity of the axial center point of the longitudinal axis of the motor is arranged, and the longitudinal axis of the throttle valve shaft and the longitudinal axis of the motor output shaft are eccentrically arranged in parallel. Is the first feature.

In addition to the first aspect of the present invention, as the abutting member, a pin is projected from the motor lever and is abutted against an abutting lever portion formed by bending the pin to the throttle valve lever. The second characteristic is that the contact lever portion is always elastically biased by a spring.

[0010]

According to the first aspect of the invention, the radius connecting the contact point of the contact member and the shaft center point of the output shaft of the motor is connected to the contact point of the contact member and the shaft center point of the throttle valve shaft. Since the radius is smaller than the radius, the operating angle of the throttle valve shaft can be reduced with respect to the operating angle of the motor. Thus, the angular accuracy of the throttle valve can be improved without changing the angular accuracy of the motor as compared with the conventional one.

Further, according to the second aspect of the present invention, since the contact member serving as the transmitting means is formed by the pin attached to the motor lever and the contact lever portion formed by bending the throttle valve lever, the contact member is extremely formed. It can be easily formed, and furthermore, since the pin and the abutment lever portion are always elastically held in the abutting state by the spring, wear at these abutting portions is suppressed, and the motor throttle valve is prevented. When operating in the closing direction, the throttle valve can be operated in the closing direction without delaying the operation of the motor.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an intake air amount control device for an internal combustion engine according to the present invention will be described below with reference to FIGS. FIG.
2 is a vertical cross-sectional view of the relevant part, and FIG. 2 is a right side view of FIG.
The same reference numerals are used for those having the same structure as in FIG. In addition, the upper and lower sides and right and left sides in the description refer to the drawings, and are not limited to these. Reference numeral 1 is a throttle body, through which an intake passage 2 is bored. Reference numeral 3 denotes a throttle valve shaft which crosses the center of the intake passage 2 and whose both ends are rotatably supported by the throttle body 1. The throttle valve shaft 3 has a throttle valve 4 for opening and closing the intake passage 2.
Is attached. A throttle valve lever 5 is integrally attached to the right end of the throttle valve shaft 3 in FIG. On the other hand, the throttle valve shaft 3
The second throttle valve lever 6 is integrally attached to the left end of the
The rotation of the second throttle valve lever 6 is performed by the throttle body 1
It is transmitted to the throttle valve opening sensor 7 arranged on the left side end 1B of the vehicle through transmission means such as a lever bending portion. That is,
The throttle valve opening sensor 7 detects an opening position state and an acceleration / deceleration state of the throttle valve shaft 3 (in other words, the throttle valve 4) to detect an EC.
An electric signal is output to U30.

Reference numeral 8 is a motor such as a step motor or a DC motor arranged on the right end 1A of the throttle body 1. The rotation of the motor 8 is applied from the output shaft 8A of the motor to the motor lever 9 and as a transmission means. It is transmitted to the throttle valve lever 5 via the contact member T. Incidentally, N is a throttle valve return spring that applies a rotational force in the closing direction of the throttle valve 4 to the throttle valve shaft 3. In the present embodiment, one end of the throttle valve return spring is locked to the throttle body 1 and the other end is Second throttle valve lever 6
Locked in. The shape or arrangement of the throttle valve return spring N is not limited to this embodiment.

The present invention has the following features. This will be described with reference to FIGS. 1, 2 and 3. FIG. 3 is a diagram showing an arrangement state, and is shown in a simplified manner for ease of explanation. As described above, the throttle valve shaft 3 is arranged so as to cross the center of the intake passage 2, and the longitudinal axis XX of the throttle valve shaft 3 crosses the center of the intake passage 2 and the longitudinal axis. Core line X-
The axial center point A of X is located at the center of the intake passage 2. And
The throttle valve lever 5 attached to the right end of the throttle valve shaft 3 has a contact lever portion 5A formed by bending rightward in FIG.
Is formed. The contact lever portion 5A serves as one contact member T1 forming the contact member T. Incidentally, 5B is a first spring locking portion provided on the opposite side of the contact lever portion T1. Therefore, the throttle valve lever 5 is connected to the throttle valve shaft 3
Of FIG. 3, the opening actuation side G of the throttle valve 4 is counterclockwise in FIG.

Next, on the motor lever 9 arranged at the left end of the output shaft 8A of the motor 8, a pin 9A is arranged so as to project to the left in FIG. 1, and this pin 9A has a contact member T. It becomes the other contact member T2 which constitutes. Incidentally, 9B is a second spring locking portion provided on the opposite side of the pin 9A. The throttle valve lever 5 and the motor lever 9 include a contact lever portion 5A as one contact member T1 and
The rotation of the motor lever 9 is transmitted to the throttle valve lever 5 by contacting with the pin 9A as the other contact member T2 at the contact point B.

The output shaft 8A of the motor 8 is arranged as follows. First, the longitudinal axis Y of the output shaft 8A
-Y is arranged parallel to the longitudinal axis XX of the throttle valve shaft 3. (However, they are not arranged concentrically) Then, the axial center point C of the longitudinal axis Y-Y of the output shaft 8A of the motor 8 is
A line E1-E2 connecting the axial center point A of the longitudinal axis line XX of the throttle valve shaft 3 and the contact point B of the contact members T1 and T2.
And a line F passing through the axial center point A and orthogonal to the line E1-E2
1-F2 and between the lines E1-A-F1 formed on the opening operation side G of the throttle valve 4. These arrangements are particularly well shown in FIG.

Reference numeral 10 denotes a spring, one end of which is locked to the first spring locking portion 5B of the throttle valve lever 5 and the other end of which is locked to the second spring locking portion 9B of the motor lever 9, The lever portion 5A and the pin 9A are always brought into contact with each other by the elastic force of the spring 10. The spring 10 is not shown in FIG.

Next, the operation will be described. When the driver depresses and operates the accelerator pedal 27 according to his / her will, this operation amount is mechanically input to the accelerator pedal sensor 29 through the transmission means 28, and this operation amount is converted into an electric signal by the accelerator pedal sensor 29. The electric signal is converted and output to the ECU 30. And E
The CU 30 outputs an electric signal corresponding to the operation of the accelerator pedal 27 to the motor 8 through the output circuit. According to the above, the motor 8 rotates the output shaft 8A, the motor lever 9, and the contact member T according to the operation of the accelerator pedal 29.
It is applied to the throttle valve lever 5 and the throttle valve shaft 3 via the throttle valve 4. By this, the throttle valve 4 can obtain the throttle valve opening degree according to the operation of the accelerator pedal 29 and is controlled by the throttle valve 4. Air is supplied into the combustion chamber 34 via the intake pipe 38 and the intake port 35.

In the above intake air amount control operation, the intake air amount control device of the present invention has the following characteristic operation. A more specific example will be described with reference to FIG. 4. The axial center point A of the longitudinal axis XX of the throttle valve shaft 3 is at the center of the intake passage 2 and the longitudinal axis of the intake passage 2. It is located on the core line ZZ. On the other hand, the longitudinal axis Y of the output shaft 8A of the motor 8
The axial center point C of -Y is eccentric to the right by 2 mm from the axial center point A along the longitudinal axis Z-Z of the intake passage 2, and the intake passage 2
Is located eccentrically 2 mm above the axial center point A along a line WW orthogonal to the longitudinal axis Z-Z. That is,
The axial center point C of the longitudinal axis line Y-Y of the output shaft 8A is a line E1-E2 connecting the axial center point A of the throttle valve shaft 3 and the contact point B between the pin 9A and the contact lever 5A. , Passing through the axial center point A,
The line F1-F2 is orthogonal to the line E1-E2 and is located between the lines E1-A-F1 formed on the opening operation side G of the throttle valve 4. The radius R1 between the axial center point A of the throttle valve shaft 3 and the contact point B is set to 18 mm, and the radius R2 between the axial center point C of the output shaft 8A and the contact point B is 15.68.
set to mm. The throttle valve 4 has a fully closed angle set to 5 degrees, which allows the throttle valve 4 to rotate 85 degrees from fully closed to fully open. According to the above, in the original position of the motor 8, the throttle valve 4 is held in the fully closed state, and a simplified diagram showing this state is shown in FIG. When an electric signal from the ECU 30 is input to the motor 8 from the above state, the output shaft 8A of the motor 8 rotates 40 degrees counterclockwise in the figure from the original position, and the rotation of the output shaft 8A is caused by the motor lever. 9, the pin 9A is transmitted to the contact lever portion 5A, the throttle valve lever 5, and the throttle valve shaft 3 via the contact point B. According to this, the throttle valve 4 is 3
It is opened 4.2 times. This state is shown in FIG. Further, when an electric signal from the ECU 30 is input to the motor 8 from the above state, the output shaft 8A of the motor 8 rotates 85 degrees counterclockwise in the figure from the original position, and the rotation of the output shaft 8A is the same as above. Is transmitted to the throttle valve lever 5 via the motor lever 9, whereby the throttle valve 4 is opened 72.9 degrees from the fully closed state. This state is shown in FIG. Then, when an electric signal from the ECU 30 is further input to the motor 8, the output shaft 8A of the motor 8 moves from the original position to 9
The throttle valve 4 is rotated counterclockwise by 9 degrees, whereby the throttle valve 4 is opened 85 degrees from the fully closed state, and thus the intake passage 2 is held in the fully opened state.

When the motor 8 is rotated clockwise, the contact lever portion 5A of the throttle valve lever 5 is rotated clockwise by the spring 10 so as to follow the pin 9A of the motor lever 9. 4 can block the intake passage 2 in accordance with the clockwise rotation of the motor 8. The throttle valve return spring N also functions as the spring 10.

The relationship between the operating angle of the motor 8 and the opening degree of the throttle valve 4 in the present invention described above is shown by the solid line in FIG. 8, and as shown in FIG. Compared with the throttle valve opening characteristic, the change rate of the operating angle of the throttle valve 4 can be greatly reduced.

According to the above, for example, when an operating angle of the motor 8 is 60 degrees, if an angle error of ± 5 degrees occurs (though such a large error does not actually occur), the diaphragm according to the present invention. The error range of the valve opening degree is P, and the error range of the conventional throttle valve opening degree is S. Here, as compared with the conventional throttle valve opening characteristic of the present invention as compared with the conventional throttle valve opening characteristic, the rate of change of the operating angle thereof can be greatly reduced, so that the error range becomes P <S, The error range can be greatly reduced. Therefore, it is possible to improve the angular accuracy of the throttle valve 4 by using the conventional motor 8. It should be noted that the rate of change of the throttle valve opening with respect to the operating angle of the motor is properly determined by appropriately selecting the eccentric position of the motor shaft center point, the position of each shaft center point and the contact point of the contact member, etc. Can be obtained.

Further, the operating angle of the motor 8 can be increased as compared with the conventional one (when the throttle valve has a full closing angle of 5 degrees, the operating angle of the motor can be increased from 85 degrees to 99 degrees. According to the above, the uneven wear of the bearing that supports the output shaft 8A of the motor 8 is eliminated, and the durability and reliability can be improved.

Further, the contact member T is used as a transmission member for transmitting the rotation of the motor lever 9 to the throttle valve lever 5, and as the contact member T, the pin 9A and the contact lever portion 5A are brought into contact with each other. Thus, there is no rattling or abnormal noise due to backlash, and durability and reliability can be improved. Furthermore, since the rotation of the motor 8 is transmitted to the throttle valve 4 by using the contact member T, the number of parts can be reduced and the assembling can be facilitated, and the manufacturing cost can be reduced. In this embodiment, the contact member T
Although the contact point B of is made to be a line contact, it may be made to be a surface contact, and the pin is attached to the throttle valve lever 5 side.
The contact lever portion may be formed on the motor lever 9 side.
In addition, the spring always keeps the pin 9A and the contact lever 5
According to the fact that A and B are elastically pressed and urged, the motor 8
The rotation of the throttle valve (particularly when the throttle valve 4 is rotating in the closing direction) can be satisfactorily performed without a time delay, and the contact point B is always kept in a contact state, so that the tare phenomenon occurs. Therefore, the wear of the contact point B is suppressed.

[0025]

As described above, according to the intake air amount control apparatus for the internal combustion engine of the present invention, the motor lever and the throttle valve lever are directly brought into contact with each other by the contact member, and the intake air is passed through the center of the intake passage. A line connecting the axial center point of the longitudinal axis of the throttle valve shaft traversing the path and the contact point of the contact member,
The axial center point of the longitudinal axis of the output shaft of the motor is eccentrically arranged between the lines that pass through the axial center point and are orthogonal to the line and are formed on the opening operation side of the throttle valve. In addition, since the longitudinal axis of the throttle valve shaft and the longitudinal axis of the output shaft of the motor are eccentrically arranged in parallel, the angular accuracy of the throttle valve can be improved without changing the angular accuracy of the motor. It was something that could be improved. Further, since the operating angle of the motor can be increased, the durability and reliability of the bearing that supports the output shaft of the motor can be improved. Further, as a contact member, the pin protrudes from the motor lever and contacts the contact lever portion that can be bent and formed on the throttle valve lever, and the pin and the contact lever portion are always elastically pressed by a spring. By urging the contact member, it is possible to improve the durability and reliability of the contact portion of the contact member, suppress an increase in the manufacturing cost of the contact member, and further, to suppress the rotation of the motor. Can be satisfactorily followed.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of an intake air amount control device for an internal combustion engine according to the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a schematic diagram showing a relationship between an output shaft including a motor lever and a throttle valve lever including a throttle valve shaft in FIG.

FIG. 4 is a schematic diagram showing an example of specific design dimensions of a throttle valve lever including an output shaft including a motor lever and a throttle valve shaft in FIG.

FIG. 5 is a schematic diagram showing a relationship between a motor lever and a throttle valve lever in a throttle valve fully closed state of an intake air amount control device for an internal combustion engine according to the present invention.

FIG. 6 is a schematic diagram showing the relationship between the motor lever and the throttle valve lever in the throttle valve intermediate opening state of the intake air amount control device for the internal combustion engine according to the present invention.

FIG. 7 is a schematic diagram showing the relationship between the motor lever and the throttle valve lever in the throttle valve high opening state of the intake air amount control device for the internal combustion engine according to the present invention.

FIG. 8 is a diagram showing a relationship between an opening of a throttle valve and an operating angle of a motor.

FIG. 9 is a longitudinal cross-sectional view of a main part of a conventional intake air amount control device for an internal combustion engine.

10 is a system diagram showing a state in which the intake air amount control device shown in FIG. 9 is assembled to an internal combustion engine.

[Explanation of symbols]

3 Throttle valve shaft 5 Throttle valve lever 5A Abutment lever portion 8 Motor 8A Motor output shaft 9 Motor lever 9A Pins T1, T2 Abutment member XX Longitudinal axis of throttle valve shaft Y-Y Motor output shaft Longitudinal axis A of longitudinal axis X-X axial center point B of abutting members T1 and T2 C longitudinal axis Y-Y axial center point E1-E2 axial center point A Line connecting the contact points F1-F2 Line passing through the axial center point A and orthogonal to the line E1-E2

Claims (2)

[Claims] 1. An intake passage passing through a throttle body is
Opening and closing is controlled by a throttle valve attached to a throttle valve shaft that is rotatably supported by the throttle body, and the throttle valve shaft is given a rotational force according to an electric signal output from an electronic control unit. The rotation of the motor lever is attached to the output shaft of the motor by transmitting the rotation of the motor lever attached to the output shaft of the motor to the throttle valve lever arranged at the end of the throttle valve shaft via the transmission means. In the intake air amount control device for an internal combustion engine,
The motor lever 9 and the throttle valve lever 5 contact the contact member T1.
And the contact point T1, and the contact point T1 with the axial center point A of the longitudinal axis XX of the throttle valve shaft 3 that passes through the center of the intake passage 2 and crosses the intake passage 2 directly. A line E1-E2 connecting the contact point B of T2 and the line E1-E2 passing through the axial center point A
A line F1-F2 orthogonal to 1-E2 and the throttle valve 4
Axis E of the output shaft 8A of the motor 8 between the lines E1-A-F1 formed on the opening operation side G of the axis C of the longitudinal axis Y-Y.
Is eccentrically arranged, and the longitudinal axis X of the throttle valve shaft 3 is
-X and the longitudinal axis Y-Y of the output shaft 8A of the motor 8 are eccentrically arranged in parallel with each other, and the intake air amount control device for an internal combustion engine is provided. 2. A motor lever 9 serving as the contact member.
The pin 9A is further protruded, and the pin 9A is brought into contact with an abutment lever portion 5A formed by bending the throttle valve lever 5, and the pin 9A and the abutment lever portion 5A are connected to the spring 10
2. The intake air amount control device for an internal combustion engine according to claim 1, wherein the device is always elastically biased by.