JP2007192026A - Intake control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the drivability and operability of an internal combustion engine by automatically closing a main throttle valve to an opening degree equal to or smaller than a first idle opening degree when an energization failure occurs in an electric motor for electrically driving a sub-throttle shaft. <P>SOLUTION: The main throttle valve 4 and the sub-throttle valve 9 are connected in an interlocking manner by a sub-main interlocking mechanism R, and in a sub-throttle opening sensor S fitted and connected to the sub-throttle shaft 10, a coil spring 17 exerts a spring force toward a rotor 14 in the opening direction of the sub-throttle valve 9. The sub-main interlocking mechanism R opens the main throttle valve 4 to a first idle opening degree B° in the middle opening range G of the sub-throttle valve 9 from a certain middle opening degree D° to a certain large opening degree E°, and closes the main throttle valve 4 from the first idle opening degree B° to an idle opening degree A° in the fully-opened large opening range H of the sub-throttle valve 9 from the certain large opening degree E° to a full opening degree F°. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intake air control device that controls the amount of air directed to an internal combustion engine, and in particular, an intake air intake system that is linked to an accelerator grip that is operated by a driver in an intake passage that penetrates the inside of a throttle body. The present invention relates to an intake air control apparatus for an internal combustion engine comprising: a main throttle valve that opens and closes a passage; and a sub-throttle valve that is operated by an electric motor that is driven according to the operating state of the engine and opens and closes an intake passage upstream of the main throttle valve. .

A main throttle valve operated by a driver and a sub throttle valve operated by an electric motor are arranged in an intake passage formed in the throttle body, and the electric motor is driven when the main throttle valve is fully closed. The conventional intake control device for an internal combustion engine that opens the sub-throttle valve and forcibly opens the main throttle valve toward the first idling opening degree regardless of the operation of the accelerator grip by opening the sub-throttle valve. It is disclosed in literature 1).
According to Patent Document 1, a main throttle valve that is operated by a driver to open and close the intake passage, and an intake passage upstream of the main throttle valve are disposed in an intake passage formed in the throttle body. A sub-throttle valve that is operated by an electric motor to open and close the intake passage, a cam lever having a cam surface is attached to one end of a sub-throttle shaft to which the sub-throttle valve is attached, and a main throttle valve is attached A driven lever that faces the cam surface of the cam lever is attached to one end of the main throttle shaft. When the sub throttle valve rotates in the fully open direction, the main throttle valve is mechanically moved via the driven lever according to the rotation of the cam lever. A sub-main interlocking mechanism that opens toward the first idle opening, Sub throttle shaft and the other end to be fitted in a sub-throttle opening sensor for detecting the rotation angle of the sub throttle shaft comprising the sub-throttle valve, are disclosed. (For example, a sensor shown in Patent Document 2 is used as such a sub-throttle opening sensor)
According to such an intake control device for an internal combustion engine, when the engine is cold-started, the sub-throttle valve including the sub-throttle shaft is greatly rotated in the opening direction by the electric motor toward the intermediate opening or fully opened. According to this, the main throttle valve is mechanically opened to the first idle opening by the sub-main interlocking mechanism including the cam lever and the driven lever. That is, when the sub-throttle valve is opened to the intermediate opening or fully opened, the main throttle valve is automatically opened to the first idle opening.
According to the above, an increased amount of start air suitable for cold start of the internal combustion engine can be supplied to the internal combustion engine, so that a good cold start of the internal combustion engine can be performed.
JP-A-2005-90471 JP 2001-173482 A

In the above intake control device for an internal combustion engine, as described above, an opening sensor disclosed in Japanese Patent Application Laid-Open No. 2001-173482 is employed as a sub-throttle opening sensor for detecting the rotation angle of the sub-throttle valve. The opening sensor will be described with reference to FIG. (Note that the names and symbols used in this publication are used.)
In the sensor case 7 formed by the housing 5 and the cover member 6, the rotor 8 is rotatably arranged, and the two brushes 14 a and 14 b fixedly arranged on the large-diameter portion 13 of the rotor 8 are large. It arrange | positions in sliding contact with the two resistors provided in the lower surface of the board | substrate 15 arrange | positioned facing a diameter part.
A coil spring 26 is interposed between the lower surface of the large diameter portion 13 and the bottom surface of the housing 5, and the rotor 8 is pressed toward the cover member 6 by the elastic force of the coil spring 26 in the length direction. Further, a rotational force is applied to the rotor 8 by the elastic force of the coil spring 26 in the winding direction.
In other words, when the rotor 8 rotates, a force in the rotational direction is applied to the coil spring 26 to generate a torsional force, so that the coil spring 26 returns to the original position with respect to the rotor 8. The reverse rotational force is energized.
For example, when the rotor 8 rotates clockwise, the coil spring 26 applies a counterclockwise return rotational force to the rotor 8.
The end portion of the sub-throttle shaft is fitted and disposed in the fitting hole formed in the rotor 8 of the opening sensor, and the sub-throttle shaft and the rotor 8 to which the sub-throttle valve is attached thereby. And can be rotated synchronously.
Thus, when the sub-throttle valve is opened and the sub-throttle shaft rotates, the rotor 8 rotates following this, and as a result, the brushes 14a and 14b slide on the surfaces of the two resistors. The resistance value changes according to the amount of rotation of the rotor 8, and a signal corresponding to the rotation angle of the sub-throttle shaft can be output to the external ECU.

Here, in an intake control device for an internal combustion engine including a main throttle valve and a sub-throttle valve, the sub-throttle opening sensor using the opening sensor fitted and arranged at the end of the sub-throttle shaft is It needs to be formed as follows.
That is, the spring force of the coil spring disposed in the opening sensor is urged toward the rotor 8 in the opening direction of the sub-throttle valve (in other words, the sub-throttle shaft).
This is because when an electric current failure occurs in the electric motor due to the electrical connection between the coupler of the electric motor that drives the sub-throttle shaft and the connector connected to the external power source, or corrosion of the electrical connection, etc., the coil spring This is because the sub-throttle shaft is rotationally displaced in the opening direction by the spring force to keep the sub-throttle valve open, and mechanical air control by the main throttle valve is not hindered.
Conversely, when the spring force in the closing direction is urged to the sub-throttle shaft by the coil spring, the sub-throttle valve disposed in the intake passage upstream of the main throttle valve when the electric motor is poorly energized The intake passage is inadvertently blocked by the spring force of the coil spring, and mechanical air control by the main throttle valve cannot be performed.

As described above, the opening degree sensor (the opening degree sensor in which the spring force in the opening direction of the sub-throttle valve is urged by the coil spring to the rotor 8) is used as the sub-throttle opening degree sensor of the intake control device disclosed in Patent Document 1. Used.
That is, a sub-throttle opening sensor whose spring force is urged by the coil spring in the opening direction of the sub-throttle valve is fitted and disposed at the end of the sub-throttle shaft.
According to the above, in such an intake control device, when an electric current failure occurs in the electric motor for the same reason as described above, a force in the opening direction is applied to the sub-throttle valve by the coil spring disposed in the sub-throttle opening sensor. As a result, the sub-throttle valve is shifted to the fully open state as described above under the influence of vibrations of the internal combustion engine and the vehicle.
On the other hand, the sub throttle valve and the main throttle valve are mechanically linked by a sub-main linkage mechanism formed by a cam lever attached to the sub throttle shaft and a driven lever attached to the main throttle shaft. However, as described above, when the sub-throttle valve is shifted to the fully open state, the main throttle valve is automatically held open at the first idle opening by the sub-main interlocking mechanism.
According to the above, it is difficult to lower the engine speed to be equal to or lower than the first idle speed according to the driver's intention, and the driver virtue is hindered, and improvement in operability cannot be expected.

  The intake control device for an internal combustion engine according to the present invention is made in view of the above-mentioned problems. In particular, the main throttle valve and the sub-throttle valve are interlocked by the sub-main interlocking mechanism, and the sub-throttle valve is fully opened. During rotation, the main throttle valve is mechanically held at the first idle opening by the sub-main interlocking mechanism, and the coil spring in the sub throttle opening sensor applies a spring force toward the rotor in the opening direction of the sub throttle valve. In the above-described device, when a failure in energization occurs in the electric motor that electrically drives the sub-throttle shaft, the main throttle valve can be lowered to an opening equal to or less than the first idle opening, An object of the present invention is to provide an intake control device with excellent operability.

In order to achieve the above object, an intake air control apparatus for an internal combustion engine according to the present invention has an intake passage penetrating through a throttle body and an accelerator grip operated by a driver in the intake passage. A main throttle valve that opens and closes the intake passage and an intake passage upstream of the main throttle valve and is operated by an electric motor that is driven according to the operating state of the engine to open and close the intake passage. A sub-throttle valve,
A sub-main interlocking mechanism that mechanically opens the main throttle valve toward the first idle opening when the sub-throttle valve rotates in the opening direction;
Inside, provided with a rotor, a contact, a resistor, etc., the rotor is biased in the opening direction of the sub-throttle valve by a coil spring, and a sub-throttle opening sensor fitted and connected to the sub-throttle shaft,
By the sub-main interlocking mechanism, the main throttle valve is opened to the first idle opening in the intermediate opening range from the constant intermediate opening to the constant high opening of the sub throttle valve, while the constant high opening of the sub throttle valve The first feature is that the main throttle valve is closed from the first idle opening to the idle opening in the fully opened high opening range from E to fully open.

  In addition to the first feature described above, the present invention provides a cam lever that is attached to the end of the sub-throttle shaft, and is attached to the main throttle shaft. A second feature is that it is formed by a driven lever that is attached and rotates synchronously with the main throttle shaft, and a roller that is rotatably supported by the driven lever and that faces the cam surface of the cam lever. .

According to the first feature of the present invention, when a failure in energization occurs in the electric motor, the sub-throttle shaft receives a bias force in the opening direction of the sub-throttle valve by a coil spring disposed in the sub-throttle opening sensor. As a result, the sub-throttle shaft rotates in the opening direction to hold the sub-throttle valve fully open.
When the sub-throttle valve is fully opened beyond a certain high opening, the main throttle valve is lowered toward the opening below the first idle opening by the sub-main interlocking mechanism, and the minimum rotation Can be reduced to less than the first idle rotation, which can greatly improve the driving ability and operability of the vehicle.

According to the second feature of the present invention, the sub-main interlocking mechanism that mechanically opens the main throttle valve toward the first idle opening degree when the sub-throttle valve rotates in the opening direction is provided at the end of the sub-throttle shaft. The opening of the main throttle valve with respect to the sub-throttle valve is formed by a cam lever attached to the end, a driven lever attached to the end of the main throttle shaft, and a roller rotatably disposed on the driven lever. The properties can be controlled very easily.
Further, by changing the cam surface of the cam lever, it is possible to meet the opening characteristic of the main throttle valve with respect to the sub-throttle valve required by various types of engines.

Hereinafter, an embodiment of an intake control device for an internal combustion engine according to the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of an essential part including a longitudinal axis of a sub-throttle shaft.
FIG. 2 is a right side view of FIG. 3 is a left side view of FIG. It is.
For ease of explanation, the configuration of the fuel injection valve and the like is omitted in the above figure.
Reference numeral 1 denotes a throttle body which is formed by penetrating an intake passage 2 laterally, and the intake passage 2 is a main throttle valve attached to a main throttle shaft 3 rotatably supported by the throttle body 1. 4 is controlled to open and close.
The left end of the main throttle shaft 3 protrudes to the left from the throttle body 1, and a throttle drum 5 is screwed and fixed to the end of the main throttle shaft 3 with a nut 6. The throttle drum 5 is attached to an accelerator grip (not shown). The ends of the valve closing wire Wa and the valve opening wire Wb to be connected are engaged with each other. Therefore, the throttle drum 5 is rotated counterclockwise by pulling with the valve opening wire Wb, thereby opening the main throttle valve 4. Further, by pulling the valve closing wire Wa, the throttle drum 5 is rotated in the clockwise direction, and the main throttle valve 4 is closed. A throttle return spring (not shown) is engaged with the throttle drum 5, and the throttle drum 5 is biased with a rotational force in the closing direction of the main throttle valve 5.
A main throttle valve opening sensor 7 for detecting the opening of the main throttle valve is fitted and connected to the right end of the main throttle shaft 3.
Further, 5a is an idle arm formed to extend from a part of the throttle drum 5 to the side. The lower end surface of the idle arm 5a facing the closing direction is screwed to the protruding portion of the throttle body 1. The tip of the idle adjustment screw 8 is placed in contact with it.
The idle adjusting screw 8 adjusts and controls the idle opening that is the minimum opening of the main throttle valve 4. The idle adjusting screw 8 projects the tip upward by screwing the idle adjusting screw 8, and the idle arm 5 a and the throttle drum 5. 3 is rotated counterclockwise in FIG. 3 to adjust the main throttle valve 4 in the opening direction. On the other hand, the main throttle shaft 3 including the idle arm 5a and the throttle drum 5 is rotated in the clockwise direction in FIG. Thus, the desired idle opening of the main throttle valve 4 is adjusted and controlled.

Reference numeral 9 denotes a sub-throttle valve which is disposed in the intake passage 2a upstream of the main throttle valve 4 and opens and closes the intake passage 2a. The sub-throttle valve 9 is rotatably supported by the throttle body 1 10 will be attached.
An electric motor M for electrically rotating the sub-throttle shaft 10 and a sub-throttle opening sensor S are disposed on the right side wall 1a shown in FIG.
Describing in more detail with reference to FIG. 1, the sub-throttle opening sensor S is configured as follows.
A sensor case 13 is formed by a housing 11 having a bottomed cup shape and a cover member 12 that closes the opening of the housing 11. In the sensor case 13, a large-diameter flange 14 a that faces the cover member 12, and the housing 11 A rotor 14 including a fitting hole 14b having a circular cross section that opens toward the bottom side and having a circular cross section is rotatably disposed.
Reference numeral 15 denotes a substrate that faces the large-diameter flange portion 14a of the rotor 14 with a gap and is fixedly disposed on the sensor case 13. Two resistors are provided on the side surface of the substrate 15 on the large-diameter flange portion 14a side. Two brushes 16a and 16b fixedly arranged on the large-diameter flange portion 14a of the rotor 14 are slidably arranged on the resistor.
Further, 17 is a coil spring disposed in the sensor case 13, and one end of the coil spring 17 is locked to the rotor 14 and the other end is locked to the housing 11. A spring force is applied to the rotor 14 in the opening direction of the sub-throttle valve 9 (counterclockwise in FIG. 3).
Reference numeral 18 denotes a motor storage case that surrounds the right end of the sub-throttle shaft 10, closes the gear storage recess 1 b that opens in the right side wall 1 a of the throttle body 1, and stores the electric motor M therein. 1 has a motor housing recess 18a that opens to the left in FIG. 1 and a flange 18c in which an opening 18b is formed.
The electric motor M is inserted and disposed in the motor housing recess 18a of the motor housing case 18, and the sub-throttle opening sensor S is fixedly disposed on the flange portion 18c with screws.
According to the above, the output shaft Ma of the electric motor M is disposed to protrude leftward from the left end 18b of the motor storage case 18, and the fitting hole 14b of the rotor 14 of the sub-throttle opening sensor S is formed in the motor storage case. An opening is arranged to face the opening 18b of the 18 flange portion 18c.

On the other hand, a driven gear 19 made of a large-diameter spur gear is attached to the right end of the sub-throttle shaft 10 in FIG. 1. Specifically, the sub-throttle shaft 10 has a locking step 10 a facing the right side of the sub-throttle shaft 10. The driven gear 19 is screwed and fixed by the nut 20. The driven gear 19 is disposed in the gear housing recess 1 b of the throttle body 1.
The right end of the sub-throttle shaft 10 is formed so as to pass through the nut 20 and protrude further to the right than the right side wall 1a of the throttle body 1, and the fitting hole 14b of the rotor 14 is formed in this protruding portion. A fitting projection 10b having a circular cross section with a circular cross section is formed.

A motor storage case 18 including the sub-throttle opening sensor S and the electric motor M is disposed on the right side wall 1 a of the throttle body 1, and the motor storage case 18 is attached to the right side wall 1 a of the throttle body 1 by screws 21. It is screwed and fixed toward. According to the above, the gear housing recess 1b of the throttle body 1 is closed by the motor housing case 18, and the fitting protrusion 10b at the right end of the sub throttle shaft 10 is connected to the sub throttle opening sensor S via the opening 18b of the flange 18c. The sub-throttle shaft 10 and the rotor 14 are rotatably connected in synchronization with each other. The output shaft Ma of the electric motor M is disposed so as to protrude into the gear housing recess 1b, and the drive gear 22 made of a small-diameter spur gear attached to the output shaft Ma is disposed in the gear housing recess 1b. The driven gear 19 is meshed and connected. According to the above, when the electric motor M is rotated by a drive signal from the ECU (not shown), the rotation of the electric motor M is decelerated and transmitted to the sub-throttle shaft 10 via the output shaft Ma and the driven gear 19, and the sub-throttle. The shaft 10 rotates forward and backward according to the rotation of the electric motor M, and the intake passage 2 is controlled to open and close by the sub-throttle valve 9.
On the other hand, the rotation of the sub-throttle shaft 10 is transmitted to the rotor 14 of the sub-throttle opening sensor S through the fitting protrusion 9b, and the sub-throttle shaft 10 and the rotor 14 can be rotated synchronously. Thus, the rotation angle of the sub-throttle shaft 10 is detected by the sub-throttle opening sensor S and is output as an opening signal of the sub-throttle shaft 10 (in other words, the sub-throttle valve 9) to an external ECU (not shown). The

Next, the sub-main interlocking mechanism R that opens the main throttle valve 4 toward the first idle opening when the sub throttle valve 9 rotates in the opening direction will be described with reference to FIG.
Reference numeral 23 denotes a driven lever that rotates in synchronism with the main throttle shaft 3, and a cylindrical roller 24 is rotatably supported at the tip of the driven lever.
A cam lever 25 is screwed and fixed by a nut 26 at the left end of the sub-throttle shaft 9 in FIG. 1, and a cam surface 25 a facing the roller 24 attached to the driven lever 23 is formed on the cam lever 25. Is done.

An example of the relationship between the opening of the sub throttle valve 9 and the opening of the main throttle valve 4 by the sub-main interlocking mechanism R in the present invention is shown in the diagram of FIG. The main throttle valve 4 is held at the idle opening A ° at a low opening (° C.) including the fully closed sub-throttle valve 9. The main throttle valve 4 is opened to the first idle opening B ° at a constant intermediate opening D ° of the sub-throttle valve 9.
The main throttle valve 4 is maintained at the first idle opening B ° in the intermediate opening range G from the constant intermediate opening D ° of the sub-throttle valve 9 to the constant high opening E °.
In the fully open high opening range H from the constant high opening E ° to the fully open F ° of the sub throttle valve 9, the main throttle valve 4 is off-idle opening from the first idle opening B ° to the idle opening A °. Blocked at J °.
As specific angles of the main throttle valve 4 and the sub throttle valve 9 described above, the idle opening A ° of the main throttle valve 4 is 1.2 degrees, and the first idle opening B ° is 3.5 degrees. Yes, the off-idle opening J ° is 2 degrees. Further, the low opening degree C ° of the sub-throttle valve 9 is 5 degrees, the constant intermediate opening degree is 45 degrees, the constant high opening degree E ° is 70 degrees, and the full opening F ° is 80 degrees.
However, the specific angle is only an example so far and is not limited to the numerical value.

The opening degree control of the main throttle valve 4 with respect to the rotation of the sub throttle valve 9 is achieved by the cam surface 25a of the cam lever 25 constituting the sub-main communication mechanism R shown in FIG.
In this example, the sub-throttle valve 9 rotates within a range of 80 degrees from fully closed to fully open.
The cam surface 25a is formed in the full rotation range F ° of the sub-throttle valve 9 from the cam base point “a” when the sub-throttle valve 9 is fully closed to the cam end point “e” when the sub-throttle valve 9 is fully opened. Is done.
A first cam surface 25a1 that does not contact the roller 24 is formed from the cam base point a toward C °, that is, the first point b rotated by 5 degrees. Further, from the first point b to (D ° -C °), that is, toward the second point c rotated by 40 °, the roller 24 comes into contact with the main throttle valve 4 from the idle angle A ° to the first idle angle B °, That is, the second cam surface 25a2 that opens 3.5 degrees is formed. (In other words, the second point c corresponds to a certain intermediate opening D ° position rotated 45 degrees from the cam base point a.)
Further, from the second point c to the third point d rotated by (E ° −D °), that is, 25 degrees, the roller 24 comes into contact with the main throttle valve 4 so that the first idle opening B °, that is, 3.5 degrees. A third cam surface 25a3 that maintains the open state is formed. (In other words, the third point d corresponds to a constant high opening degree E ° position rotated 70 degrees from the cam base point a.) A constant intermediate opening degree D ° of the second point c to a constant third point d. The range of the high opening E ° is referred to as an intermediate opening range G, and the main throttle valve 4 is maintained open at the first idle opening B °, that is, 3.5 degrees within this intermediate opening range G. .
Further, from the third point d to (F ° -E °), that is, toward the cam end point e rotated by 10 degrees, the roller 24 comes into contact with the main throttle valve 4 from the first idle opening B ° to the idle opening A °. A fourth cam surface 25a4 is formed which is closed toward the opening and closed at an off idle opening J °, that is, twice. (In other words, the fourth point e is the fully opened position of the sub-throttle valve 9 rotated 80 degrees from the cam base point a.)
The range from the constant high opening E ° of the third point d to the fully open F ° of the cam end point e is called a fully open high opening range H. In this fully open high opening range H, the main throttle valve 4 has a fast idle opening B. It is closed to the idling opening degree side from ° to the off idle opening degree J °.

Next, the operation of the intake control device described above will be described.
When the internal combustion engine is stopped, the throttle drum 5 is not subjected to any operating force by the driver. Therefore, the throttle drum 5 receives a spring force counterclockwise in FIG. The lower end surface of 5a is maintained in contact with the tip of the idle adjusting screw, whereby the minimum opening of the main throttle valve 4, that is, the idle opening A ° is determined.
On the other hand, in the sub-throttle valve 9, since the electric motor M is in a non-energized state, the sub-throttle valve 9 is maintained in a fully closed state, for example.
The positions of the throttle lever 5, the idle arm 5a, the follower lever 23 including the roller 24, and the cam lever 25 are indicated by solid lines in FIG. 3, and the positions of the main throttle valve 4 and the sub throttle valve 9 are indicated by dotted lines.
In this state, the cam surface 25 a of the cam lever 25, that is, the first cam surface 25 a 1 is arranged away from the roller 24, so that the main throttle valve 4 is positioned at the idle opening A ° by the idle adjustment screw 8.
It should be noted that there is no problem regardless of the position of the sub throttle valve 9 when the engine is stopped.

Next, a description will be given of a cold start at a low ambient temperature of the internal combustion engine.
When the main switch is turned on when starting the internal combustion engine, an ECU (not shown) inputs a drive signal to the electric motor M based on information such as intake air temperature, cooling water temperature, oil temperature and the like inputted thereto. The motor M is driven according to the signal, rotates the sub-throttle shaft 10 through the drive gear 22 and the driven gear 19, and opens the sub-throttle valve 9 toward the intermediate opening range G. That is, the sub-throttle valve 9 is opened from the low opening degree C ° to the range of the constant intermediate opening degree D ° to the constant high opening degree E °.
According to the above, the cam lever 25 is also opened in the range of the intermediate opening range G in synchronization with the sub-throttle shaft 10, and when the cam lever 25 rotates, the second cam surface 25 a 2 of the cam lever 25 is moved to the roller 24. Then, the driven lever 23 is rotated counterclockwise in FIG. 3 while pressing the roller 24 upward.
According to the above, the main throttle valve 4 which has been held at the idle opening A ° by the idle adjustment screw 8 passes the intake passage 2 through the first idle opening B ° in synchronization with the rotation of the driven lever 23 in the counterclockwise direction. Hold open toward.
Thus, when the internal combustion engine is started by operating the cell motor, an increased amount of start air suitable for the cold start can be supplied to the internal combustion engine by the first idle opening B °, and thus a good cold Start can be performed.
When the internal combustion engine is cold-started, the sub-throttle shaft 10 including the sub-throttle valve 9 is not opened from the fully open high opening range H, that is, from the constant high opening E ° to the fully open F °. Therefore, the fourth cam surface 25a4 of the cam lever 25 does not contact the roller 24.

Here, according to the intake air control device of the present invention, when the electric motor M is poorly energized during the operation of the engine, the opening of the main throttle valve 4 is directed from the first idle opening B ° to the idle opening A °. Thus, the off-idle opening degree J ° can be closed.
That is, when a failure in energization occurs in the electric motor M, the rotational force by the electric motor M disappears. According to this, the sub-throttle valve is caused by the spring force of the coil spring 17 housed in the sub-throttle opening sensor S. Since the sub-throttle shaft 10 including 9 receives the spring force in the opening direction, the sub-throttle valve 9 is opened to the fully open state particularly when vibrations of the internal combustion engine and the vehicle are applied.
According to the above, the cam lever 25 attached to the sub-throttle shaft 10 also rotates in the fully open high opening range H, that is, in the range of the constant high opening E ° to the fully open F °, and the fourth cam surface 25a4 of the cam lever 25 is obtained. Comes into contact with the roller 24. According to the above, the roller 24 is moved downward by the fourth cam surface 25a4 to rotate the driven lever 23 in the clockwise direction, whereby the main throttle valve 4 is moved from the first idle opening B ° to the idle opening A. The off-idle opening J ° on the ° side can be closed.
According to the above, when the energization failure of the electric motor M occurs, the rotational speed of the internal combustion engine is changed from the first idle rotation by the first idle opening B ° to the off idle opening J on the idle rotation side by the idle opening A °. Since the number of rotations can be reduced toward the off-idle rotation due to °, the vehicle driveability and operability can be greatly improved.
If the fourth cam surface 25a4 in the fully open high opening range H of the cam lever 25 has a cam shape that does not come into contact with the roller 24, the main throttle valve 4 is set in the fully open high opening range H of the sub throttle valve 9. It can be closed to an idle opening A °.

According to the present invention, the sub-main interlocking mechanism R for interlockingly connecting the sub-throttle valve 9 and the main throttle valve 4 is provided with the cam lever 25 screwed to the end of the sub-throttle shaft 10 by the nut 26, Since it is formed by the driven lever 23 having the roller 24 that faces the cam lever 25 and is attached to the throttle shaft 3, the cam lever 25 can be easily replaced, and the mechanism can be easily and inexpensively provided. it can.
According to the above, a single throttle body can be used for a plurality of engines by preparing the cam lever 25 formed with the cam surface 25a having an optimum shape for an internal combustion engine, and the versatility of the throttle body can be increased. It was a great improvement.
Further, the throttle body of the present invention can be employed in a multiple throttle body having a plurality of intake passages in which a single throttle body is employed.

1 is a longitudinal sectional view showing an embodiment of an intake control device for an internal combustion engine according to the present invention. The right view of FIG. The left view of FIG. The diagram which shows the relationship between a sub throttle valve opening and a main throttle valve opening. The enlarged view which shows the cam surface of the cam lever shown by FIG.

Explanation of symbols

3 main throttle shaft 4 main throttle valve 9 sub throttle valve 10 sub throttle shaft 23 driven lever 24 roller 25 cam lever 25a cam surface M electric motor S sub throttle opening sensor R sub-main interlocking mechanism

Claims (2)

A main throttle valve that opens and closes the intake passage in conjunction with an accelerator grip operated by a driver, and has an intake passage penetrating through the inside of the throttle body, and the main throttle valve A sub-throttle valve disposed in the upstream intake passage and operated by an electric motor driven according to the operating state of the engine to open and close the intake passage;
A sub-main interlocking mechanism that mechanically opens the main throttle valve toward the first idle opening when the sub-throttle valve rotates in the opening direction;
Inside, provided with a rotor, a contact, a resistor, etc., the rotor is biased in the opening direction of the sub-throttle valve by a coil spring, and a sub-throttle opening sensor fitted and connected to the sub-throttle shaft,
The sub-main interlocking mechanism opens the main throttle valve 4 to the first idle opening B ° in the intermediate opening range G from the constant intermediate opening D ° of the sub-throttle valve 9 to the constant high opening E °. The main throttle valve 4 is closed from the first idle opening B ° to the idle opening A ° in the full opening high opening range H from the constant high opening E to the full opening F of the sub-throttle valve 9. An intake control device for an internal combustion engine. The sub-main interlocking mechanism is attached to the end portion of the sub-throttle shaft 10 and is attached to the main throttle shaft 3 and the cam lever 23 that rotates synchronously with the sub-throttle shaft 10. 2. An internal combustion engine according to claim 1, wherein the internal combustion engine is formed by: a driven lever 23 that rotates in a rotating manner; and a roller 24 that is rotatably supported by the driven lever 23 and that faces the cam surface 25a of the cam lever 25. Intake control device.

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