JP2002349396A - Bypass intake air amount control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact device for controlling a bypass intake air amount in which the adhesion of carbon or the like to a flow rate control part can be reduced to a large extent and a prescribed flow accuracy can always be maintained. SOLUTION: A bypass valve V is composed of a valve body 11 having a valve guide hole 19 and a valve piston 25 fitted into the hole 19. The valve body 11 is provided with a valve inlet hole 23 which is opened onto the valve guide hole 19 and continues into the upstream side of a bypass passage 15, and a valve outlet hole 24 which is opened onto the inner peripheral face of the guide hole 19 adjacently to the inlet hole 23 and continues into the downstream side of the bypass passage 15. Further, in the other end of the valve piston 25, there are provided a hollow part 25a, a communication opening 26 which passes through one side wall of the hollow part 25a to always communicate with the inlet hole 23, and a flow control opening 29 which cooperates with the outlet hole 24 to control a bypass intake air amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bypass intake air amount control device used for controlling the idling speed of an engine and the like, and more particularly, to a bypass passage for opening and closing the intake passage of a throttle body. The present invention relates to an improvement in which a bypass path is connected, a bypass valve for opening and closing the bypass path is provided in the bypass path, and an actuator for operating the bypass valve is connected to the bypass valve.

[0002]

2. Description of the Related Art Such a bypass intake air amount control apparatus is disclosed, for example, in Japanese Patent Laid-Open Publication No. Sho 59-34444,
It is already known as disclosed in Japanese Patent Application Publication No.

[0003]

In the conventional bypass intake air amount control device, the entire flow control portion of the bypass valve is always exposed to the downstream side of the bypass passage. Is determined by the cross-sectional area on the downstream side of the bypass. In such a device, when the engine is back-fired, the entire flow control unit is exposed to the gas, so that a foreign substance such as carbon adheres to the entire flow control unit over a long period of time, and the accuracy of the flow control decreases. In particular, the flow rate when the bypass valve is fully opened is greatly reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and can greatly reduce the adhesion of carbon or the like to a flow control unit, can always maintain a predetermined flow accuracy, and can achieve compactness. It is an object of the present invention to provide a simple bypass intake air amount control device.

[0005]

In order to achieve the above object, according to the present invention, an intake passage of a throttle body is connected to a bypass which bypasses a throttle valve which opens and closes the intake passage. A bypass valve for opening and closing the valve, and an actuator for operating the valve is connected to the bypass valve. In a bypass intake air amount control device, the bypass valve slides in a valve body having a valve guide hole and a valve guide hole. A valve piston fitted to the valve body and having an end connected to the actuator; a valve body having a valve inlet hole opening to the valve guide hole and connected to the upstream side of the bypass passage; And a valve outlet hole that opens to the inner peripheral surface of the valve guide hole and is connected to the downstream side of the bypass. On the other hand, the other end of the valve piston cooperates with the hollow portion, the communication opening portion which penetrates one side wall of the valve piston corresponding to the hollow portion, and is always in communication with the valve inlet hole. The first feature is that a flow control opening for controlling the bypass intake air amount is provided.

According to the first feature, when the valve piston is in the fully closed state, the flow control opening is completely hidden from the valve outlet hole. Even if the backfire phenomenon occurs, the flow control opening is not exposed to the backfire gas, so that it is possible to prevent foreign matters such as carbon from adhering to the flow control opening.

In addition, on one side wall corresponding to the hollow portion of the valve piston, there are provided a communication opening which is always in communication with the valve inlet, and a flow control opening which controls the amount of bypass intake air in cooperation with the valve outlet. With this arrangement, the valve inlet hole and the valve outlet hole that open to the valve guide hole can be arranged close to each other, which can contribute to the compactness of the bypass valve.

The present invention, in addition to the first feature, further comprises a flow control opening, a wide portion, and a notch-shaped narrow portion opening at one end of the wide portion on the valve outlet hole side. The second feature is that the bypass intake air amount at the time of idling of the engine is controlled by cooperation of the narrow portion and the valve outlet hole.

According to the second feature, the fine control of the bypass intake air amount can be easily performed when the engine is idling.

Further, the present invention is characterized in that, in addition to the first or second features, the communication opening and the flow control opening are provided as a single opening in the valve piston.

According to the third feature, the communication opening and the flow control opening can be worked at once, which can contribute to the improvement of productivity. The holes can be arranged closer to each other, and the size of the bypass valve can be further reduced.

Further, according to the present invention, in addition to any one of the first to third features, when the throttle body is mounted on the vehicle engine, the valve piston comes to the uppermost portion of the bypass passage and the valve piston is mounted on the engine. A fourth feature is that the valve guide hole and the valve piston are arranged such that the axis has a gradient that rises slightly toward the actuator side.

According to the fourth feature, when the throttle body is attached to the vehicle engine, the valve piston and the actuator have only a slight horizontal gradient, and thus receive vertical vibrations accompanying the running of the vehicle. Even
Vertical vibration is not strongly applied to the connecting portion between the valve piston and the actuator, and wear due to the vibration of the connecting portion can be avoided, and the metering performance of the valve piston can be stabilized.

In addition, when the valve piston comes to the top of the bypass passage and the gradient applied to the valve piston is at the upper side of the actuator, the flow of oil and moisture in the blow-by gas and EGR gas during the operation of the engine. Even if sexual foreign matter enters the valve guide hole from the intake passage through a part of the bypass, the foreign matter does not rise to the step motor side, thus preventing malfunction of the actuator due to freezing or accumulation of foreign matter. be able to.

Further, in the present invention, in addition to the fourth feature, a fifth feature is that the valve guide hole and the valve piston are arranged in parallel with the intake path of the throttle body.

According to the fifth feature, the protrusion of the valve piston and the actuator toward the outside of the throttle body is suppressed to be small, and the bypass intake air amount control device can be made compact.

Further, according to the present invention, in addition to any one of the first to fifth features, the actuator is constituted by a step motor, and its rotor is mounted on a valve piston non-rotatably fitted in a valve guide hole. A sixth feature is that the connection is made via a screw mechanism.

According to the sixth feature, the rotation of the output shaft of the step motor is transmitted as axial displacement to the valve piston while being reduced by the screw mechanism, and the opening degree of the valve piston can be finely adjusted.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIG. 1 is a longitudinal sectional side view of a main part of a motorcycle engine equipped with a throttle body with a bypass valve according to the present invention, and FIG. 2 is a partially broken side view of the throttle body with the bypass intake air amount control device (FIG. 3). 3 is a sectional view taken along line 3-3 of FIG. 2, and FIG. 4 is a sectional view taken along line 4-3 of FIG.
4 is a sectional view of FIG. 5, FIG. 5 is a sectional view of line 5-5 in FIG. 4, and FIG.
7 is a sectional view taken along line 6-6 of FIG. 7, FIG. 7 is a sectional view taken along line 7-7 of FIG. 5, and shows the idle control state of the bypass valve. FIG. 8 shows the startup and fast idle control state of the bypass valve.
FIG. 9 is a sectional view corresponding to FIG. 7, and FIG. 9 is a sectional view corresponding to FIG. 7, showing a fully closed state of the bypass valve.

First, in FIG. 1, reference symbol E denotes an engine mounted on the body of a motorcycle, and an intake pipe Ei connected to a cylinder Eh of the engine has a gradient θ whose upstream side is slightly upward. Granted. A throttle body 1 having an intake path 2 connected to the intake pipe Ei is connected to an upstream end of the intake pipe Ei. Therefore, in the connection state with the intake pipe Ei, the throttle body 1 is arranged such that the intake passage 2 has a gradient θ in which the upstream side is slightly upward, like the intake pipe Ei. The upstream end of the intake passage 2 has a funnel shape, to which an air cleaner is connected. A fuel injection valve I for injecting fuel toward the intake valve is attached to the cylinder Eh.

2 to 4, the throttle body 1
On both sides of the middle part of the shaft hole 4, which is orthogonal to the axis of the intake passage 2,
A pair of bosses 3, 3 'each having a 4' is formed, and a butterfly type throttle valve 5 for opening and closing the intake passage 2 is provided on a valve shaft 6 rotatably supported by the shaft holes 4, 4 '. It is fixed. At one end of the valve shaft 6, a throttle drum 7 for connecting an operation wire 9 connected to a throttle operation member (not shown) is fixed. At the other end of the valve shaft 6, a rotor 8a of a throttle sensor 8 for detecting the opening of the throttle valve 5 is fixed.

On one side of the throttle body 1, an intake passage 2 is provided.
And a housing 10 having a bottom surface 1a parallel to the axis of the housing 10 is integrally formed. The other boss 3 'protrudes from the bottom surface 1a of the housing 10, and the shaft hole 4' of the boss 3 'and the bottom surface 1a are arranged so as to be orthogonal to each other. The bottom surface 1a of the housing 10 is a mounting surface, on which the connecting surface 11a of the valve body 11 housed in the housing 10 is overlapped, and the valve body 11 is fixed to the throttle body 1 by bolts 12. You. Further, a cover plate 13 for hermetically closing the open surface of the housing 10 is fixed by bolts 14.

The valve body 11 has a first receiving hole 37 for receiving the other boss 3 'and the rotor 8a.
b is attached. The pickup coil 8b constitutes a throttle sensor 8 that electrically detects the opening of the throttle valve 5 in cooperation with the rotor 8a.

As shown in FIGS. 2 to 6, a bypass 15 is formed from the throttle body 1 to the valve body 11. The bypass path 15 is provided with a throttle valve 5
A bypass inlet hole 20 (see FIGS. 4 and 5) formed in the throttle body 1 to communicate between the intake passage 2 and the mounting surface 1a on the upstream side of the intake passage 2 and the intake passage 2 on the downstream side of the throttle valve 5. And a bypass outlet hole 21 (see FIGS. 4 and 6) formed in the throttle body 1 so as to communicate between the mounting surfaces 1a, and a bypass inlet hole 20 formed at the joint surface 11a of the valve body 11 at one end. An upstream groove 16 extending at the other end upward, a downstream groove 17 also formed at the joint surface 11a of the valve body 11 and extending at one end to the bypass outlet hole 21 and extending the other end upward; Above the hole 20 and the bypass outlet hole 21, a bottomed cylindrical valve guide hole 19 formed in the valve body 11 in parallel with the intake passage 2;
The bypass inlet hole 23 penetrates between the inner peripheral surface of the valve guide hole 19 and the upper end groove bottom of the upstream groove portion 16 and penetrates between the inner peripheral surface of the valve guide hole 19 and the upper end groove bottom of the downstream groove passage 17. And a bypass outlet hole 24. Thus, the bypass path 15 is connected to the intake path 2 so as to bypass the throttle valve 5, and the valve guide hole 19 is disposed at the top of the bypass path 15.

At this time, the bypass inlet hole 20, the bypass outlet hole 21 and the shaft holes 4, 4 'are arranged in parallel with each other so that they can be machined at once with a multi-axis drilling machine. Also, the bypass inlet hole 23 and the bypass outlet hole 24
Are arranged parallel to the bypass inlet hole 20 and the bypass outlet hole 21 while being close to each other, and the bypass outlet hole 24 is located downstream of the bypass inlet hole 23 along the intake path 2.

The valve guide hole 19 is provided in the intake passage 2.
And in the state where the throttle body 1 is connected to the intake pipe Ei, a slight gradient θ similar to that of the intake passage 2.
(See FIG. 2).

As shown in FIGS. 5 to 7, a valve piston 25 constituting a bypass valve V is slidably fitted in the valve guide hole 19 in cooperation with the valve body 11. In order to prevent the rotation of the valve piston 25, a key 42 integrally formed on the inner peripheral surface of the valve guide hole 19 is engaged with the key groove 41 on the outer periphery thereof.

The valve piston 25 has its intake passage 2
A hollow portion 25a opening at the downstream end face along the opening, a communication opening 26 penetrating through one side wall of the valve piston 25 corresponding to the hollow portion 25a, and allowing the hollow portion 25a to always communicate with the bypass inlet hole 23; A flow control opening 29 for controlling the amount of bypass intake air in cooperation with the outlet hole 24 is provided. At that time, in the illustrated example, the communication opening 26 and the flow control opening 29 are formed as a single opening.

The communication opening 26 has a lateral width along the circumferential direction of the valve piston 25 substantially equal to the diameter of the bypass inlet hole 23, and the flow control opening 29 has a wide width equal to the communication opening 26. Part 29a and the wide part 29a,
A narrow portion 29b that opens in a notch shape at one end edge on the downstream side along the intake path 2 is formed. In the low opening region of the valve piston 25, the opening area of the narrow portion 29b to the valve outlet hole 24 is controlled, and the amount of bypass intake air is finely adjusted. In the high opening range, the opening areas of the narrow portion 29b and the wide portion 29a to the valve outlet hole 24 are controlled, and the bypass intake air amount is adjusted relatively largely.

A step motor 28 is provided above the valve piston 25 along the gradient θ (see FIGS. 2 and 7).
Is disposed coaxially with the valve 25, and the rotor 28 a of the step motor 28 is connected to the valve piston 25 via the screw mechanism 27. That is, an operating member 32 having a screw hole 31 is non-rotatably fitted (see FIG. 6) and attached to the center portion of the valve piston 25, and is integrally formed with the screw hole 31 of the operating member 32 with the rotor 28a. The connected screw shaft 30 is screwed. The stator 28b of the step motor 28 is housed and fixed in a second housing hole 38 of the valve body 11 which is continuous with the valve guide hole 19.

At one end of the actuating member 32, an enlarged portion 32 which contacts the ceiling surface of the hollow portion 25a of the valve piston 25 is provided.
a is formed, and a clip 35 is locked to the other end, and between the clip 35 and the valve piston 25,
A coil spring 45 for urging the valve piston 25 in the direction of contact with the expanding portion 32a is contracted. Thus, the operating member 32 is integrally connected to the valve piston 25.

Referring again to FIGS. 3 and 4, a seal groove 46 surrounding the upstream groove 16 and the downstream groove 17 is formed on the joint surface 11a of the valve body 11, and the joint surface 11a is formed on the seal groove 46. When it is placed on the mounting surface 1a of the throttle body 1, a seal member 47 that is in close contact with the mounting surface 1a is mounted. Thus, each groove 16, 1
The open surface 7 is hermetically closed by the mounting surface 1a.

Next, the operation of this embodiment will be described.

In the fully closed state of the throttle valve 5,
Valve piston corresponding to engine operating conditions such as engine start, fast idling, normal idling, engine braking, etc. based on engine operating conditions such as throttle valve opening, boost negative pressure, intake air temperature, engine temperature, etc. In order to obtain an optimum opening of 25, the amount of power to the step motor 28 is controlled to rotate the rotor 28a forward or backward. When the rotor 28a rotates or reversely rotates, the rotation is transmitted as an axial displacement to the valve piston 25 while being decelerated by the screw mechanism 27, so that the opening degree of the valve piston 25 can be finely adjusted.

When the valve piston 25 occupies a high opening position near the step motor 28, as shown in FIG. 8, the flow control opening 29 of the valve piston 25 has a wide portion 29a and a narrow portion. Since 29b faces the valve outlet hole 24, the amount of intake air sucked into the engine through the bypass passage 15 is controlled in a relatively large amount by the opening areas of the wide portion 29a and the narrow portion 29b to the valve outlet hole 24, and It is possible to cope with the start of E and the fast idling operation.

When the valve piston 25 occupies a low opening position near the step motor 28, the narrow portion 29b of the flow control opening 29 faces the valve outlet hole 24 as shown in FIG. The amount of intake air flowing through the nozzle 15 is relatively small and finely controlled by the opening area of the narrow portion 29b to the valve outlet hole 24, and can correspond to normal idling of the engine.

When the throttle valve 5 is opened, an amount of intake air corresponding to the opening degree is supplied to the engine through the intake passage 2, and the engine moves to the output operation range.

At the time of engine braking, as shown in FIG. 9, the valve piston 25 is moved to the limit near the step motor 28 so that the valve piston 25 is fully closed, so that the engine braking effect can be enhanced. . In such a fully closed state of the valve piston 25, the flow control opening 29 is completely hidden from the bypass outlet hole 24, so that a backfire phenomenon occurs in the engine E, and the inner peripheral surface of the bypass outlet hole 24 becomes backfire gas. Even if exposed, the flow control opening 29 is not exposed to the gas, and foreign matter such as carbon can be prevented from adhering to the flow control opening 29.

In such a bypass intake air amount control apparatus, the valve piston 25 and the step motor 28 are attached to the valve body 11 which is detachably attached to the housing 10 integrated with the throttle body 1, so that the bypass valve assembly with the actuator is formed. As a result, the machining of the throttle body 1 is reduced, and the assembly can be manufactured in parallel with the throttle body 1, so that productivity can be improved.
Moreover, by removing the valve body 11 from the throttle body 1, the bypass passage 15 and the valve piston 2 are removed.
5. Maintenance of the step motor 28 and the like can be easily performed. In addition, by changing the specifications of the valve piston 25 and the step motor 28 in the valve body 11, it is possible to easily provide the throttle body 1 with the bypass valve V having different specifications while using the same throttle body 1. The mass productivity of the body 1 can be improved.

The upstream groove 16, the downstream groove 17, the valve inlet hole 23 and the valve outlet hole 24, which constitute the main part of the bypass 15, can be formed all at once on the joint surface 11 a of the valve body 11. The valve guide hole 19 in which the valve inlet hole 23 and the valve outlet hole 24 are open is arranged in parallel with the joint surface 11a of the valve body 11, so that the upstream groove 16 and the downstream groove 17 are extremely easy to manufacture. The valve guide hole 19 and the valve guide hole 19 can be formed close to each other and formed in the valve body 11 which is relatively thin, so that the bypass intake air amount control device can be made compact.

Further, the valve outlet hole 24 is connected to the valve inlet hole 2
By disposing the bypass passage 15 on the downstream side along the intake path 2, a reasonable configuration of the bypass passage 15 can be obtained without crossing the upstream groove 16 and the downstream groove 17, and the bypass intake air amount control device can be obtained. Can be further reduced in size.

On one side wall corresponding to the hollow portion 25a of the valve piston 25, a communication opening 26 constantly communicating with the bypass inlet hole 23, and a flow control opening for controlling the bypass intake air amount in cooperation with the bypass outlet hole 24. Since the portion 29 is provided, the bypass inlet hole 23 and the bypass outlet hole 24 that are open to the valve guide hole 19 can be arranged close to each other.
The size of the bypass valve V can be reduced.

In particular, when the communication opening 26 and the flow control opening 29 are formed as a single opening in the valve piston 25, the processing of the communication opening 26 and the flow control opening 29 can be performed all at once. Not only can contribute to the improvement of the productivity, but also the bypass valve V can be made more compact by making the bypass inlet hole 23 and the bypass outlet hole 24 closer to each other.

When the throttle body 1 is mounted on the engine E of the motorcycle, the valve piston 25 and the step motor 28 connected via the screw mechanism 27 are connected.
Has a slight gradient θ close to horizontal, so that even if it receives the vertical vibration accompanying the traveling of the vehicle, the vertical vibration does not act violently on the connecting portion between the valve piston 25 and the step motor 28, that is, the screw mechanism 27. In addition, the measurement performance of the valve piston 25 can be stabilized by avoiding wear due to the vibration of the mechanism 27.

When the throttle body 1 is connected to the intake pipe Ei, the valve guide hole 19 is
A slight gradient θ placed on top of and attached to
Sets the step motor 28 slightly above the valve piston 25, so that the blow-by gas or E
Even if fluid foreign substances such as oil and moisture in the GR gas enter the valve guide hole 19 from the intake path 2 through a part of the bypass path 15, the foreign substances do not go up to the step motor 28 side. Therefore, it is possible to prevent the step motor 28 from causing an operation failure due to freezing or accumulation of foreign matter.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist of the present invention. For example, the valve body 11 can be formed integrally with the throttle body 1.

[0048]

As described above, according to the first aspect of the present invention, a bypass which bypasses a throttle valve which opens and closes the intake passage is connected to the intake passage of the throttle body, and the bypass passage is connected to the bypass passage. A bypass valve that opens and closes a valve, and an actuator that operates the valve is connected to the bypass valve.
The bypass valve is slidably fitted in the valve body having the valve guide hole and the valve guide hole.
The valve body includes a valve piston having one end connected to an actuator. The valve body has a valve inlet hole that opens to the valve guide hole and is connected to the upstream side of the bypass passage. A valve outlet hole is provided on the inner peripheral surface and connected to the downstream side of the bypass passage. On the other hand, the other end of the valve piston passes through a hollow portion and one side wall of the valve piston corresponding to the hollow portion. A communication opening constantly communicating with the valve inlet hole;
Since the flow control opening for controlling the amount of bypass intake air is provided in cooperation with the valve outlet hole, the flow control opening is completely hidden from the valve outlet hole when the valve piston is fully closed. Even if the backfire phenomenon occurs during the output operation of the engine with the piston fully closed,
The flow control opening is not exposed to the backfire gas, and foreign matter such as carbon can be prevented from adhering to the flow control opening. In addition, on one side wall corresponding to the hollow portion of the valve piston, a communication opening that constantly communicates with the valve inlet hole and a flow control opening that controls the amount of bypass intake air in cooperation with the valve outlet hole are provided. Thus, the valve inlet hole and the valve outlet hole that open to the valve guide hole can be arranged close to each other, which can contribute to the downsizing of the bypass valve.

According to the second aspect of the present invention, in addition to the first aspect, the flow rate control opening is provided with a wide portion and a cutout opening at one end edge of the wide portion on the valve outlet hole side. The bypass intake air amount at the time of idling of the engine is controlled by cooperation of the narrowed portion and the valve outlet hole. Fine control can be easily performed.

According to a third feature of the present invention, the first
Alternatively, in addition to the second feature, since the communication opening and the flow control opening are provided as a single opening in the valve piston, the communication opening and the flow control opening can be processed at once. This not only contributes to an improvement in productivity, but also makes it possible to arrange the valve inlet hole and the valve outlet hole closer to each other, thereby further reducing the size of the bypass valve.

According to a fourth feature of the present invention,
In addition to any one of the first to third features, when the throttle body is attached to the vehicle engine, the valve piston comes to the top of the bypass passage, and the axis of the valve piston moves toward the actuator side. Since the valve guide hole and the valve piston are arranged so as to have an ascending gradient, the valve piston and the actuator have a slight horizontal gradient when the throttle body is attached to the vehicle engine. Even when receiving vertical vibrations caused by traveling of the vehicle, vertical vibrations are not strongly applied to the connection between the valve piston and the actuator, and wear due to the vibration of the connection is avoided to stabilize the measurement performance of the valve piston. be able to. In addition, since the valve piston comes to the top of the bypass and the gradient applied to the valve piston is at the top of the actuator, the blow-by gas and EGR
Even if fluid foreign substances such as oil and moisture in the gas enter the valve guide hole from the intake path through a part of the bypass path, the foreign substances do not go up to the step motor side, so that the foreign substances freeze or accumulate. Therefore, it is possible to prevent the malfunction of the actuator due to the above.

Further, according to a fifth aspect of the present invention,
In addition to the fourth feature, the valve guide hole and the valve piston are arranged in parallel with the intake path of the throttle body, so that the valve piston and the actuator are prevented from protruding outward from the throttle body, and the bypass intake air amount is controlled. The device can be made compact.

Further, according to a sixth aspect of the present invention,
In addition to any of the first to fifth features, the actuator is constituted by a step motor, and its rotor is connected via a screw mechanism to a valve piston non-rotatably fitted in the valve guide hole. The rotation of the output shaft of the step motor is transmitted as an axial displacement to the valve piston while being reduced by the screw mechanism, and the opening degree of the valve piston can be finely adjusted.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a main part of a motorcycle engine equipped with a throttle body with a bypass valve according to the present invention.

FIG. 2 is a partially cutaway side view of the throttle body with a bypass valve (a sectional view taken along line 2-2 in FIG. 3).

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 5 and shows an idle control state of the bypass valve.

FIG. 8 is a cross-sectional view corresponding to FIG. 7 and showing a startup state of a bypass valve and a fast idle control state.

FIG. 9 is a sectional view corresponding to FIG. 7, showing a fully closed state of the bypass valve.

[Explanation of symbols]

 E ····· Engine V ······ Bypass valve 1 ······························································································································································································· · Bypass passage 19 ··· Valve guide hole 23 ··· Valve inlet hole 24 ··· Valve outlet hole 25 ··· Valve piston 25a · · · Hollow portion 26 ··· Communication opening 27 · ... Screw mechanism 28 ... Actuator (step motor) 29 ... Flow control opening 29a ... Wide part 29b ... Narrow part

Claims (6)

[Claims] An intake path (2) for a throttle body (1).
Is connected to a bypass path (15) that bypasses a throttle valve (5) that opens and closes the intake path (2). In a bypass intake air amount control device comprising a valve (V) and an actuator (28) for operating the valve (V), a bypass valve (V) is connected to a valve body (11) having a valve guide hole (19).
And a valve piston (25) slidably fitted in the valve guide hole (19) and having one end connected to an actuator (28).
The valve inlet hole (23) which opens to the valve guide hole (19) and is connected to the upstream side of the bypass passage (15).
And an opening on the inner peripheral surface of the valve guide hole (19) adjacent to the valve inlet hole (23) and the bypass passage (1).
5), a valve outlet hole (24) is provided on the downstream side, and the other end of the valve piston (25) has a hollow portion (25a) and a valve piston (25) corresponding to the hollow portion (25a). ), A communication opening (26) which constantly communicates with the valve inlet hole (23) through one side wall, and a flow control opening ( 29), wherein a bypass intake air amount control device is provided. 2. The bypass intake air amount control device according to claim 1, wherein the flow control opening is formed in the wide portion.
a) and a notch-shaped narrow portion (29a) opened at one end edge of the wide portion (29a) on the valve outlet hole (24) side.
b), the bypass intake air amount at the time of idling of the engine is controlled by cooperation of the narrow portion (29b) and the valve outlet hole (24). Control device. 3. The bypass intake air amount control device according to claim 1, wherein the communication opening and the flow control opening are provided as a single opening in the valve piston. A bypass intake air amount control device, characterized in that: 4. The bypass intake air amount control device according to claim 1, wherein the valve piston (25) is connected to the bypass passage (25) when the throttle body (1) is attached to the vehicle engine (E). 15) and the valve guide hole (19) and the valve piston (2) so that the axis of the valve piston (25) has a gradient (θ) slightly rising toward the actuator (28).
5) A bypass intake air amount control device, wherein 5) is arranged. 5. The bypass intake air amount control device according to claim 4, wherein the valve guide hole (19) and the valve piston (25) are arranged in parallel with the intake passage (2) of the throttle body (1). A bypass intake air amount control device. 6. The bypass intake air amount control device according to claim 1, wherein the actuator comprises a step motor (28), and a rotor (28a) thereof is rotated by a valve guide hole (19). A bypass intake air amount control device, characterized in that it is connected to a valve piston (25), which is immovably fitted, via a screw mechanism (27).