WO2013058271A1

WO2013058271A1 - Engine intake control device

Info

Publication number: WO2013058271A1
Application number: PCT/JP2012/076800
Authority: WO
Inventors: 大地稲垣; 中次　幸一
Original assignee: 株式会社ケーヒン
Priority date: 2011-10-20
Filing date: 2012-10-17
Publication date: 2013-04-25
Also published as: BR112014008809A2; BR112014008809B1; IN2014CN02525A; CN103890374A; CN103890374B; JPWO2013058271A1; JP5693742B2

Abstract

In this engine intake control device, in which a bypass valve (30) comprises a bottom wall (30d), side walls (30c, 30c) that extend upwards from both sides of said bottom wall (30d), and first and second end walls (30a, 30b) that extend upwards from both ends of the bottom wall (30d), said bypass valve is shaped like a box, with the face opposite the bottom wall (30d) being an open face (30e). The bypass valve (30) is slidably fitted into a valve guide hole (20), and the following are placed in the bypass valve (30) through the open face (30e): a sliding piece (34); and a coil spring (38) that is supported by the first end wall (30a) and biases the sliding piece (34) toward the second end wall (30b). The second end wall (30b) is provided with a control groove (37) that engages with a rotation-prevention protrusion (34c) on the sliding piece (34) and prevents the sliding piece (34) from rotating. This makes it possible to absorb eccentricity between the rotary output shaft of a motor and this bypass valve without using an Oldham coupling.

Description

Engine intake control device

The present invention has both ends of an intake passage provided in a throttle body and opened and closed by a throttle valve, an inlet hole that opens to an intake passage upstream of the throttle valve, and an outlet hole that opens to an intake passage downstream of the throttle valve. And a valve guide hole having a valve seat surface that is a part of the bypass and that has a metering hole connected to the outlet hole on one inner surface, and is slidably and non-rotatably fitted in the valve guide hole. The present invention relates to an improvement in an intake control device for an engine, which is provided with a bypass valve that opens and closes the metering hole and a motor that opens and closes the bypass valve via a screw mechanism.

Such an intake control device for an engine is already known as disclosed in Patent Document 1 below.

Japanese Unexamined Patent Publication No. 2009-114997

In conventional intake control systems for such engines, even if there is an eccentricity due to manufacturing errors between the motor's rotational output shaft and the bypass valve, the eccentricity is absorbed and the bypass valve is opened and closed by the motor's rotational output shaft. In order to ensure smoothness, the female screw member of the screw mechanism and the bypass valve are connected via an Oldham joint. However, since the Oldham joint has a large number of parts and a complicated structure, it is an obstacle to reducing the cost of the intake control device.

The present invention has been made in view of such circumstances, and is capable of absorbing the eccentricity between the rotation output shaft of the motor and the bypass valve without using a complicated Oldham joint. An object of the present invention is to provide an intake control device for an engine.

In order to achieve the above object, the present invention provides an intake passage provided in a throttle body and opened and closed by a throttle valve, an inlet hole opened to an intake passage upstream of the throttle valve, and an intake passage downstream of the throttle valve. A bypass having an outlet hole that is open at both ends, a valve guide hole that is a part of the bypass and has a valve seat surface that is open to a measurement hole that is continuous with the outlet hole, and an inner surface of the valve guide hole. In the intake control device for an engine, comprising: a bypass valve that is slidably and non-rotatably fitted to open and close the measuring hole; and a motor that drives the bypass valve to open and close via a screw mechanism. Comprises a bottom wall, both side walls rising from both ends of the bottom wall, and first and second end walls rising from both ends of the bottom wall. , A box shape having a surface facing the bottom wall as an open surface, and a slide piece supported from the open surface by the first end wall in the bypass valve. A coil spring that is biased in a contact direction with the wall, and the second end wall is provided with a restriction groove that engages with a rotation projection of the slide piece to prevent rotation of the slide piece, The screw mechanism is constituted by a screw hole provided in the slide piece and a screw shaft integrally connected to the rotation output shaft of the motor and screwed into the screw hole.

According to the present invention, in addition to the first feature, an inner side surface of the valve guide hole in which the metering hole is opened is formed on a flat valve seat surface, and a bottom wall of the bypass valve is formed on the valve seat surface. A second feature is that the planar outer surface is slidably contacted to prevent the bypass valve from rotating relative to the valve guide hole.

Further, in addition to the first or second feature, the present invention provides the slide piece with a lateral hole in which an inner end of the screw hole is opened, and a distal end portion of the screw shaft on the inner surface on the back side of the lateral hole. A third feature is that the fully open position of the bypass valve is regulated by contacting the valve.

Furthermore, in addition to any of the first to third features, the present invention provides a contact surface between the slide piece and the second end wall between the contact surfaces by a load of the coil spring. According to a fourth aspect of the present invention, the valve is formed on an inclined surface so as to generate a component force that presses the valve seat surface side of the inner surface of the valve guide hole where the metering hole opens.

According to the first feature of the present invention, the slide piece and the bypass valve can be displaced relative to each other in the vertical direction at the engaging portion between the anti-rotation protrusion and the restriction groove, and between the bypass valve and the valve guide hole. Since there is a gap that enables displacement of the bypass valve in the lateral direction, even if there is an eccentricity due to manufacturing errors between the rotary output shaft of the motor and the bypass valve, the displacement of the slide piece in the vertical direction and the bypass valve The eccentricity can be absorbed by the displacement in the lateral width direction, and therefore, the inside of the valve guide hole can be smoothly slid without using the complicated Oldham joint and without breaking the bypass valve. In addition, since the fixed end of the coil spring that connects the slide piece and the bypass valve in the axial direction is supported by the first end wall of the bypass valve, a dedicated retainer member for supporting the fixed end is not required. , It is possible to reduce the number of parts and simplify the structure.

Also, when assembling the intake control device, if the slide piece is housed together with the coil spring from the open surface in a box-shaped bypass valve having an open surface, and the bypass valve is fitted into the valve guide hole, Since the upper open surface is closed on the upper side of the valve guide hole, it is possible to prevent the guide piece from being detached from the upper open surface. In addition, the structure can be simplified. In addition, since the accommodating space in the box-shaped bypass valve having an open surface has a wide cross section by the amount of the open surface, a coil spring and a slide are placed in the accommodating space while reducing the size of the bypass valve. The piece can be easily accommodated.

According to the second feature of the present invention, the planar contact between the valve seat surface of the valve guide hole and the bypass valve makes it possible to easily prevent the bypass valve from rotating within the valve guide hole and to ensure the operation of the screw mechanism. Can be made. In addition, according to the planar contact between the valve seat surface of the valve guide hole and the bypass valve, even if the bypass valve moves in the lateral direction within the valve guide hole, the opening of the measuring hole adjusted by the bypass valve can be reduced. It does not cause fluctuations.

According to the third feature of the present invention, the valve body is provided with a lateral hole in which the inner end of the screw hole is opened, and the tip of the screw shaft is brought into contact with the inner surface on the back side of the lateral hole. The fully open position of the bypass valve can be regulated by the structure.

According to the fourth aspect of the present invention, by using the set load of the coil spring, the bypass valve can be pressed against the valve seat surface of the valve guide hole where the upstream end of the metering hole opens, and therefore, by vibration. The bypass valve can be prevented from lifting and the opening of the measuring hole can be adjusted accurately.

1A and 1B show an intake control device for an engine according to an embodiment of the present invention in an attached state to the engine. FIG. 1A is a side view, and FIG. 1B is a rear view with an air cleaner removed. (First embodiment) FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. (First embodiment) 3 is a cross-sectional view taken along line 3-3 of FIG. (First embodiment) 4 is an exploded perspective view of the main part of FIG. (First embodiment)

2. Throttle body 3 ... Intake passage 7 ... Throttle valve 18 ... Bypass 18a ... Inlet hole 18c ... Metering hole 18d ... Outlet hole 20 ... Valve guide hole 20a ... Valve seat surface 27 ... Motor (electric motor)
30 .... Bypass valve 30a ... First end wall (front end wall)
30b ... second end wall (rear end wall)
30e ... Open surface 33 ... Screw mechanism 34 ... Slide piece 34c ... Anti-rotation projection 35 ... Screw shaft 36 ... Side hole 37 ... Restriction groove 38 ... ... Coil springs 41, 41 '... Contact surface 42 ... Screw holes

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

First embodiment

First, in FIG. 1, a throttle body 2 is attached via an intake pipe 1 to an engine E mounted on a motorcycle body. The throttle body 2 has an intake passage 3 at the center thereof that communicates with the intake port of the engine E through the intake pipe 1. An air cleaner 4 is connected to the upstream end of the throttle body 2, and a fuel injection valve 5 that can inject fuel toward the intake port of the engine E is attached to the intake pipe 1. The throttle body 2 is disposed so as to be inclined so that the axis A of the intake passage 3 forms an angle θ with the upstream side facing upward with respect to the horizontal plane H when attached to the engine E.

A valve shaft 6 disposed horizontally and orthogonal to the axis A of the intake passage 3 is rotatably supported in the middle portion of the throttle body 2. The valve shaft 6 is a butterfly type that opens and closes the intake passage 3. The throttle valve 7 is fixed. A throttle drum 8 for connecting an operation wire connected to a throttle operation member (not shown) is fixed to one end of the valve shaft 6, and a sensor box 9 is attached to the side surface of the throttle body 2 opposite to the throttle drum 8. . The sensor box 9 includes a throttle sensor 10 that detects the opening of the throttle valve 7, a negative pressure sensor 11 that detects boost negative pressure downstream of the intake passage 3, output signals of these sensors, and other engine E An electronic control unit 12 that obtains operation information and controls the operation of an electric motor 27 described later is housed.

1 and 2, a support base 15 is integrally formed on the upper side wall of the throttle body 2. An upward mounting surface 15 a parallel to the axis A of the intake passage 3 is formed on the support base 15, the valve body 16 is overlaid on the mounting surface 15 a, and fastened to the support base 15 with bolts 17.

A bypass 18 that bypasses the throttle valve 7 and communicates between the upstream portion and the downstream portion of the intake passage 3 is formed in the eaves support 15 and the valve body 16. The bypass 18 includes an inlet hole 18a provided from the support base 15 to the valve body 16 so as to open to the intake passage 3 upstream of the throttle valve 7, and the valve body 16 so as to be adjacent to the inlet hole 18a. A measuring hole 18c provided between the inlet hole 18a and the measuring hole 18c, a communication hole 18b provided in the valve body 16 so as to communicate with the inlet hole 18a, and a supporting base so that the measuring hole 18c communicates with the intake passage 3 downstream from the throttle valve 7. 15 and an outlet hole 18d provided in the motor. Thus, when the throttle valve 7 is fully closed, the intake air of the engine E flowing through the bypass 18 sequentially passes through the inlet hole 18a, the communication hole 18b, and the measuring hole 18c and the outlet hole 18d. Between the attachment surface 15 a and the lower surface of the valve body 16, a seal member 19 surrounding each part of the bypass 18 is interposed.

Furthermore, the valve body 16 is provided with a valve guide hole 20 that partially overlaps the downstream end of the communication hole 18b while traversing the upstream opening end of the measuring hole 18c. In the illustrated example, the valve guide hole 20 is disposed in parallel with the valve shaft 6, but may be disposed in parallel with the axis A of the intake passage 3.

A cylindrical motor housing 21 is integrally connected to one end portion of the valve body 16. The motor housing 21 has a motor mounting hole 23 connected to the open end of the valve guide hole 20 via an annular step portion 22. , An annular seal recess 24 having a larger diameter and continuing to the open end of the motor mounting hole 23 is provided.

2 to 4, a bypass valve 30 is slidably fitted into the valve guide hole 20 from the motor mounting hole 23 side. The valve guide hole 20 and the bypass valve 30 have a square cross section, and the bypass valve 30 cannot be rotated in the valve guide hole 20.

バルブ The valve guide hole 20 having a square cross section ends at the intermediate position of the communication hole 18b, and the length of each side thereof is longer than the inner diameter of the communication hole 18b having a circular cross section. Therefore, the front end wall of the valve guide hole 20 forms a shoulder portion 20b that stands up from the inner periphery of the intermediate portion of the communication hole 18b.

A fixed cylindrical portion 27a of an electric motor 27 is fitted in the saddle motor mounting hole 23, and an O-ring 28 that is in close contact with the outer peripheral surface of the proximal end of the fixed cylindrical portion 27a is mounted in the seal recess 24. At this time, a disc-shaped seal member 29 that is in close contact with the outer peripheral surface of the rotation output shaft 27b protruding from the end surface of the fixed cylindrical portion 27a is sandwiched between the end surface of the fixed cylindrical portion 27a and the annular step portion 22. . The electric motor 27 is fastened to the motor housing 21 with bolts 30. The electric motor 27 includes a coupler 31 that protrudes to the side.

The rotary output shaft 27 b of the electric motor 27 is connected to the bypass valve 30 via the screw mechanism 33. The screw mechanism 33 is non-rotatably supported by the bypass valve 30 and is integrally connected to the slide piece 34 having a screw hole 42 at the center and the rotary output shaft 27b, and screwed into the screw hole 42 of the slide piece 34. And the screw shaft 35 to be formed. Thus, if the rotation output shaft 27b, that is, the screw shaft 35 is rotated, the non-rotatable slide piece 34 is sent in the axial direction, and the slide piece 34 moves the bypass valve 30 between the fully closed position and the fully open position. Can be moved in the direction. The fully closed position of the bypass valve 30 is a forward position where the bypass valve 30 abuts against the shoulder 20b and closes the upstream end of the measuring hole 18c. The fully open position of the bypass valve 30 is that the bypass valve 30 is connected to the measuring hole 18c. It is a retreat position which fully opens the upstream end.

As clearly shown in FIGS. 2 and 4, the front end portion of the slide piece 34 is formed with a horizontal hole 36 penetrating the slide piece 34 in the lateral width direction, and the tip of the screw hole 42 is opened to the horizontal hole 36. It is over.

On the other hand, the screw shaft 35 is formed with a spherical end 35c at the tip, and the spherical end 35c abuts against the cylindrical inner surface of the lateral hole 36, thereby restricting the fully opened position of the bypass valve 30. It is like that.

The bypass valve 30 includes a front end wall 30a facing the shoulder 20b, a rear end wall 30b on the electric motor 27 side, and a

side wall

30c, 30c and a bottom facing each other by integrally connecting the both

end walls

30a, 30b. It is made up of a wall 30d and has a box shape with the upper surface being an open surface 30e. The bottom surface of the bottom wall 30d is a flat surface, and the rear end wall 30b is provided with a regulation groove 37 penetrating in the axial direction and the vertical direction.

On the other hand, the slide piece 34 includes a cylindrical portion 34a disposed in the bypass valve 30, a stopper flange 34b formed at the rear end of the cylindrical portion 34a and abutting against the inner surface of the rear end wall 30b, and the stopper flange. 34b includes a rotation-preventing protrusion 34c that is slidably brought into surface contact with the restriction groove 37 so as to slidably come into contact with the restriction groove 37. A gap 44 is provided between the opposing surfaces of the stopper flange 34b and the restriction groove 37. Therefore, the slide piece 34 and the bypass valve 30 can be relatively displaced in the vertical direction Y and the lateral width direction X.

Further, a coil spring 38 surrounding the cylindrical portion 34a of the slide piece 34 is provided between the front end wall 30a and the stopper flange 34b. The coil spring 38 holds the bypass valve 30 at the contact position between the stopper flange 34b and the rear end wall 30b by the set load, and thereby, the gap between the slide piece 34 and the bypass valve 30 is always rattled in the axial direction. Connect without any loss.

Further, in the bypass valve 30 and the valve guide hole 20, the gap 39 in the vertical direction Y is managed as small as possible within a range in which the bypass valve 30 can be slid in order to prevent lifting from the valve seat surface 20 a of the bypass valve 30. However, since the displacement in the lateral width direction X of the bypass valve 30 does not affect the lifting of the bypass valve 30 from the valve seat surface 20a, the gap 40 in the lateral width direction X can be managed relatively rough.

The contact surfaces 41 and 41 'between the stopper flange 34b and the rear end wall 30b are inclined so as to approach the coil spring 38 toward the lower side. Therefore, both contact surfaces 41 and 41' are coil springs. When they are pressed against each other with a set load of 38, a component force is generated between the contact surfaces 41 and 41 'to press the rear end wall 30b, that is, the bypass valve 30, downward. Are pressed against the valve seat surface 20a of the valve guide hole 20 which is open at the upstream end. In addition, since the valve guide hole 20 and the bypass valve 30 have a rectangular cross section and the bottom surfaces of the valve guide hole 20 and the bypass valve 30 are flat, the valve guide hole 20 and the bypass valve 30 are within the gap 40 between the valve guide hole 20 and the bypass valve 30. Even if the bypass valve 30 moves in the lateral width direction X orthogonal to the axis, the opening of the measuring hole 18c adjusted by the bypass valve 30 is not changed.

The coil spring 38 surrounding the cylindrical portion 34 a of the heel slide piece 34 is formed with a tightly wound portion 38 a that covers the lateral hole 36.

Next, the operation of this embodiment will be described.

When the throttle valve 7 is fully closed, the electronic control unit 12 in the sensor box 9 attached to one side of the throttle body 2 is used to adjust the throttle valve opening, engine intake negative pressure, intake air temperature, engine temperature, engine speed, etc. In order to obtain an optimum opening degree of the bypass valve 25 corresponding to the engine operating conditions such as engine starting, fast idling, normal idling, engine braking, etc. The rotation output shaft 27b of the electric motor 27 is rotated forward or reverse. When the rotor 28a rotates or reversely rotates, the rotation is transmitted as an axial displacement to the bypass valve 25 through the slide piece 34 while being decelerated by the screw mechanism 27. Therefore, the opening degree of the bypass valve 25 can be finely adjusted. .

Thus, the screw shaft 35 of the screw mechanism 33 pulls the bypass valve 30 rearward, and the spherical end portion 35a at the tip of the screw shaft 33 abuts against the inner surface of the lateral hole 36 of the bypass valve 30, so that the bypass valve 30 is fully opened. (See FIG. 2) is restricted, and at this time, the measuring hole 18c is fully opened. Further, the screw shaft 35 of the screw mechanism 33 feeds the bypass valve 30 forward, and the front end of the bypass valve 30 is brought into contact with the shoulder 20b of the valve body 16, whereby the fully closed position of the bypass valve 30 is regulated. Sometimes the measurement hole 18c is fully closed. And the opening degree of the measurement hole 18c is adjusted by the intermediate position of the bypass valve 30 between the fully opened position and the fully closed position. The amount of intake air flowing through the bypass 15 is finely controlled by the opening of the measuring hole 18c, and can cope with engine starting, fast idling, normal idling, engine braking, and the like.

If the throttle valve 7 is opened, an amount of intake air corresponding to the opening is supplied to the engine through the intake passage 3, and the engine moves to the output operation range.

By the way, the slide piece 34 and the bypass valve 30 are connected in the axial direction without any play by the coil spring 38, and the bypass valve 30 can follow the axial movement of the slide piece 34 without delay. In addition, the slide piece 34 and the bypass valve 30 can be relatively displaced in the vertical direction Y and the lateral width direction X at the surface contact portion between the anti-rotation protrusion 34 c and the restriction groove 37. Even if the rotation output shaft 27b of the electric motor 27 is eccentric due to manufacturing errors with respect to the bypass valve 30 that is in close contact with 20a, the eccentricity is absorbed by the displacement of the slide piece 34 in the vertical direction Y and the lateral width direction X with respect to the bypass valve 30. can do. Therefore, even if an Oldham joint having a complicated structure is not used, it is possible to prevent an unbalanced load from acting on the rotation output shaft 27b and the bypass valve 30 of the electric motor 27. Therefore, the bypass valve 30 is brought into close contact with the valve seat surface 20a. It can be smoothly slid with a proper posture.

Further, since the fixed end of the coil spring 38 that connects the slide piece 34 and the bypass valve 30 in the axial direction is supported by the front end wall 30a of the bypass valve 30, a dedicated retainer member for supporting the fixed end is also unnecessary. As described above, the number of parts of the intake control device can be reduced and the structure can be simplified.

Further, since the lower side surface of the valve guide hole 20 is a valve seat surface 20a in which the measuring hole 18c connected to the intake passage 3 downstream from the throttle valve 7 is opened, the bypass valve 30 is set to an intermediate opening or a fully closed state. When in position, the valve seat surface 20a can be securely adhered by gravity and the action of the negative intake pressure of the engine E.

Further, the contact surfaces 41 and 41 ′ between the stopper flange 34 b of the slide piece 34 and the rear end wall 30 b of the bypass valve 30 are inclined so as to approach the coil spring 38 toward the lower side. When the set load is received, a component force that presses the bypass valve 30 downward is generated. Therefore, the bypass valve 30 is also pressed against the valve seat surface 20a, and can be securely adhered to the valve seat surface 20a. Therefore, it is possible to prevent the bypass valve 30 from being lifted due to vibration and to accurately adjust the opening degree of the measuring hole 18c.

The restriction of the fully open position of the bypass valve 30 is restricted by the spherical end 35a of the screw shaft 35 coming into contact with the cylindrical inner peripheral surface of the lateral hole 36 provided in the bypass valve 30 itself. There is no need to provide a stopper member in the bypass valve 30, which contributes to a reduction in the number of parts and simplification of the structure, and a reduction in cost.

In addition, the contact portion between the spherical end portion 35a of the screw shaft 35 and the cylindrical inner peripheral surface of the lateral hole 36 is a surface contact with a relatively large contact area, so that the surface pressure of the contact portion is kept low. The wear resistance can be improved, and the fully open position accuracy of the bypass valve 30 can be properly maintained over a long period of time.

When the screw hole 42 into which the screw shaft 35 is screwed is machined into the slide piece 34, prior to that, the lower hole of the screw hole 42 and the lateral hole 36 are drilled, and then the lower hole In this way, not only can the machining deficiency of the screw hole 42 be surely prevented, but also the chips generated at that time can be discharged smoothly from the lateral hole 36. In addition, when the screw hole 42 is cleaned, the remaining chips can be smoothly discharged from the lateral hole 36, so that a highly accurate screw hole 42 can be obtained.

The coil spring 38 that surrounds the cylindrical portion 34a of the slide piece 34 is formed with a tightly wound portion 38a that covers the lateral hole 36, so that the tightly wound portion 38a causes a lateral hole 36 for foreign matter that has entered the bypass valve 30. Therefore, it is possible to prevent foreign matter from entering the threaded portion of the screw hole 42 and the screw shaft 35 without using a special cover, and the smooth operation of the screw mechanism 33 is guaranteed. .

In assembling the intake control device, first, the slide piece 34 to which the coil spring 38 is attached is housed in the bypass valve 30 from the open surface 30e while the coil spring 38 is contracted, and the rotation prevention projection 34c of the slide piece 34 is provided. The stopper flange 34 b is brought into contact with the inner surface of the rear end wall 30 b of the bypass valve 30 while engaging with the restriction groove 37 of the bypass valve 30. Then, the screw shaft 35 on the side of the electric motor 27 to which the seal member 29 and the O-ring 28 are attached is screwed into the screw hole 42 of the slide piece 34 to constitute an assembly of the electric motor 27 and the bypass valve 30. Alternatively, the screw shaft 35 may be first screwed into the screw hole 42 of the slide piece 34, and then the slide piece 34 may be housed in the bypass valve 30 together with the coil spring 38 from the open surface. In any case, the assembly of the bypass valve 30 and the slide piece 34 is easy, and the assembly of the assembly of the electric motor 27 and the bypass valve 30 is improved.

Next, the bypass valve 30 of the assembly is fitted into the valve guide hole 20 of the valve body 16. At this time, since the open surface 30e of the bypass valve 30 is closed on the upper side surface of the valve guide hole 20, it is possible to prevent the slide piece 34 from being detached from the open surface 30e of the bypass valve 30. No special detachment prevention means is required, so that the assembly can be improved and the structure can be simplified. In addition, the accommodating space in the box-shaped bypass valve 30 whose upper surface is the open surface 30e has a wide cross section by the amount that the upper surface is the open surface 30e. Therefore, the bypass valve 30 can be made compact. However, the coil spring 38 and the slide piece 34 can be easily accommodated in the accommodation space.

Subsequently, after the electric motor 27 is fitted into the motor mounting hole 23 of the motor housing 21, the electric motor 27 is fastened to the motor housing 21 with the bolt 32, and the assembly of the valve body 16 and the electric motor 27 is configured.

Then, the valve body 16 of this assembly is placed on the upward mounting surface 15 a of the support base 15 of the throttle body 2 and fastened to the support base 15 with bolts 17. The fastening surfaces of the support base 15 and the valve body 16 are arranged so as to intersect with the direction of gravity. Therefore, even if a strong vertical vibration is applied to the throttle body 2 and the valve body 16 while the vehicle equipped with the engine E is running, Almost no shear load acts on the fastening surfaces of the support base 15 and the valve body 16 and the bolts 17 for fastening, thereby preventing the displacement of the valve body 16 and improving the durability of the valve body 16 system. be able to.

In addition, the valve body 16 that supports the heavy electric motor 27 is attached to the support 15 on the upper side wall of the throttle body 2, so that the throttle drum 8, the sensor box 9, and the valve body 16 are connected to both side surfaces of the throttle body 2. It will be distributed on the upper surface, and the weight applied to the throttle body 2 can be balanced, thereby avoiding the application of an uneven load to the connecting portion between the throttle body 2 and the intake pipe 1. obtain.

During operation of the engine E, foreign matter such as oil or moisture in blow-by gas or EGR gas may enter the bypass 18, and even if the foreign matter passes through the valve guide hole 20 and enters the electric motor 27 side, The sheet member 29 interposed between the electric motor 27 and the motor housing 21 can prevent foreign matter from entering the electric motor 27. Therefore, it is possible to prevent the electric motor 28 from malfunctioning due to freezing or accumulation of foreign matter.

The valve guide hole 20 having a square cross section ends at the intermediate position of the communication hole 18b, and the length of each side thereof is longer than the groove width and depth of the communication hole 18b having a circular cross section. Since the front end wall of the hole 20 stands from the inner periphery of the communication hole 18b and forms a shoulder 20b that restricts the fully closed position of the bypass valve 30, a special stopper member that restricts the fully closed position of the bypass valve 30 Can be omitted from the valve body 16, and the structure can be simplified.

In addition, since the bypass valve 30 and the valve guide hole 20 have a square cross section, the shoulder valve and the valve guide hole have a circular cross section whose diameter is the length of one side of the square. A wide contact area between the portion 20b and the bypass valve 30 can be ensured, which can contribute to improvement of the durability of the bypass valve 30.

Further, when the bypass valve 30 and the valve guide hole 20 are square in cross section, and the bypass valve 30 occupies the fully open position, the bypass valve and valve guide hole having a circular cross section with the length of one side of the square as a diameter. In comparison with the case where the valve guide hole 20 is adopted, the valve guide hole 20 has an expansion chamber having a large volume communicating with the communication hole 18b defined by the front end surface of the bypass valve 30, and intake air passes through the communication hole 18b. After passing, the flow of the intake air can be effectively attenuated in the expansion chamber, and as a result, foreign matter contained in the intake air can be prevented from entering the bypass valve 30 side.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, instead of the electric motor 27, a step motor or other types of motors can be used.

Claims

An intake passage (3) provided in the throttle body (2) and opened and closed by the throttle valve (7), an inlet hole (18a) opened to the intake passage (3) upstream of the throttle valve (7), and the throttle valve A bypass (18) having outlet holes (18d) that open to the downstream intake passage (3) at both ends, and a metering hole that is a part of the bypass (18) and continues to the outlet hole (18d) ( 18c) a valve guide hole (20a) having a valve seat surface (20a) on one inner side surface, and the metering hole (18c) fitted into the valve guide hole (20) so as to be slidable and non-rotatable. In an intake control device for an engine, comprising: a bypass valve (30) for opening and closing the valve; and a motor (27) for driving the bypass valve (30) to open and close via a screw mechanism (33).
The bypass valve (30) includes a bottom wall (30d), both side walls (30c, 30c) rising from both side ends of the bottom wall (30d), and first and second sides rising from both ends of the bottom wall (30d). It is composed of two end walls (30a, 30b), and has a box shape in which a surface facing the bottom wall (30d) is an open surface (30e), and the bypass valve (30) is formed in the valve guide hole. (20) is slidably fitted,
In the bypass valve (30), the slide piece (34) is supported by the slide piece (34) and the first end wall (30a) from the open surface (30e) to the second end wall (30b). And a coil spring (38) for urging in the contact direction with
The second end wall (30b) is provided with a regulation groove (37) that engages with a rotation projection (34c) of the slide piece (34) and prevents the slide piece (34) from rotating.
The screw mechanism (33) is integrally connected to the screw hole (42) provided in the slide piece (34) and the rotation output shaft (27b) of the motor (27) to be connected to the screw hole (42). An intake control device for an engine characterized by comprising a screw shaft (35) to be screwed together.
The intake control apparatus for an engine according to claim 1,
An inner surface of the valve guide hole (20) through which the metering hole (18c) opens is formed in a flat valve seat surface (20a), and the bottom of the bypass valve (30) is formed on the valve seat surface (20a). Intake control of an engine, characterized in that the planar outer surface of the wall (30d) is slidably brought into contact with the valve guide hole (20) to prevent the slide piece (34) from rotating. apparatus.
The intake control apparatus for an engine according to claim 1 or 2,
The slide piece (34) is provided with a lateral hole (36) in which the inner end of the screw hole (42) is opened, and the tip end of the screw shaft (35) is formed on the inner surface on the back side of the lateral hole (36). An intake control device for an engine, characterized in that the fully open position of the bypass valve (30) is regulated by contact.
The intake control apparatus for an engine according to any one of claims 1 to 3,
The contact surfaces (41, 41 ') between the slide piece (34) and the second end wall (30b) are moved between the contact surfaces (41, 41') by the load of the coil spring (38). The bypass valve (30) is formed on an inclined surface so as to generate a component force that presses toward the valve seat surface (20a) side of the inner surface of the valve guide hole (20) through which the measuring hole (18c) opens. The engine intake control system.