Intake control valve and assembly method thereof

An intake control valve has a body, a valve, and a shaft. The valve has a connecting portion, a first boss located at an end of the connecting portion in the rotation axial direction; and a second boss located at an other end of the connecting portion in the rotation axial direction. The body has first and second bearing portions supporting the first and second protruding portions, respectively, first and second projection portions projecting inward from inner surfaces of the first and second bearings, respectively, to slidably support the first and second bosses, respectively, and first and second insertion openings defined between one circumferential end and an other circumferential end of the first and second projection portions, respectively. The first and second projection portions partially cover the first and second bosses, respectively, in a circumferential direction of the first boss and the second boss.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2013-230995 filed on Nov. 7, 2013, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to an intake control valve and an assembly method thereof. Especially, the intake control valve is used in an intake system (i.e., a variable intake system) for an internal combustion engine.

BACKGROUND

Conventionally, an internal combustion engine (i.e., an engine) having cylinders includes a surge tank, and the surge tank is divided into two chambers, a first surge tank and a second surge tank, by disposing a partition wall. The partition wall includes an opening through which the first surge tank and the second surge tank are communicated with each other. An intake control valve is disposed at the opening. The intake control valve has a valve part (e.g., a butterfly valve). When the butterfly valve is fully closed, the first surge tank and the second surge tank are separated from each other. When the butterfly valve is fully open, the first surge tank and the second surge tank are communicated with each other. Such variable intake system is described in, for example, patent document 1 (JP No. 4053393 corresponding to US 2004/0055565 A1).

The intake control valve has a valve holder. The valve holder will be referred to as a valve body hereafter. The valve body includes a valve hole passing through the valve holder. The butterfly valve includes a shaft holder to which a shaft is inserted. The shaft holder is rotatably disposed in a bearing of the valve body such that the valve hole is opened or closed by moving the shaft. The valve body having the butterfly valve is inserted in the opening of the surge tank.

According to the intake control valve described in patent document 1, the shaft is inserted in the shaft holder. A recessed portion of the butterfly valve and a valve holding portion of the shaft are fitted to each other, and the butterfly valve is fastened to the shaft by a bolt. Therefore, the number of components and man-hour are large, and cost increases.

Then, a shaft may be press-fitted to a butterfly valve made of synthetic resin, as described in patent document 2 (JP No. 4901016), to reduce the number of components and man-hour so as to reduce cost.

According to an intake control valve described in patent document 2, the butterfly valve is integrally formed with a shaft holder and bearings. The shaft holder is located at a center portion of the butterfly valve, and the shaft is fixed to the shaft holder. One of the bearings is located at an end side of the butterfly valve in a rotation axial direction of the butterfly valve, and the other bearing is located at another end side of the butterfly valve facing the one end side in the rotation axial direction. The bearings rotate and slide relative to bearing holders provided in the valve body of an intake manifold.

According to the above structure, since the valve body has the bearings, bearings holding the butterfly valve are not provided. In this case, a location of the butterfly valve is not set with respect to the valve hole of the valve body. Accordingly, the shaft cannot be press fitted in the shaft holder of the butterfly valve. In the result, specific bearing holders described in patent document 2 are required.

SUMMARY

It is an objective of the present disclosure to provide an intake control valve and an assembly method thereof with which a central axis of first and second bosses that are included in a valve and a central axis of first and second bearing portions that are included in a body can easily coincide with each other.

It is another objective of the present disclosure to provide the intake control valve and the assembly method thereof with which a shaft can be inserted easily to a connecting portion of the valve, the first and second bosses, and the first and second bearing portions such that a producing cost can be reduced by reducing the number of components and assembly works.

An intake control valve of the present disclosure has a body, a valve, and a shaft. The body has a valve seat that is formed in an annular shape and has a space passing through the valve seat to communicate with a cylinder of an internal combustion engine. The valve fits the valve seat to close the space or separating from the valve seat to open the space. The shaft is connected to the valve to rotate integrally with the valve, and extends in a rotation axial direction of the valve. The valve has a connecting portion, a first boss, and a second boss. The connecting portion extends in the rotation axial direction. The first boss has a cylindrical shape and is located at an end of the connecting portion in the rotation axial direction. The second boss has a cylindrical shape and is located at an other end of the connecting portion in the rotation axial direction. The shaft has a fitting portion, a first protruding portion, and a second protruding portion. The fitting portion fits the connecting portion and is coupled with the connecting portion, the fitting portion passing through the first boss and the second boss in the rotation axial direction. The first protruding portion protrudes from an end surface of the first boss in the rotation axial direction outward from the valve in the rotation axial direction. The second protruding portion protrudes from an end surface of the second boss in the rotation axial direction outward from the valve in the rotation axial direction. The body has a first bearing portion, a second bearing portion, a first projection portion, a second projection portion, a first insertion opening, and a second insertion opening. The first bearing portion supports the first protruding portion rotatably. The second bearing portion supports the second protruding portion rotatably. The first projection portion is formed in a semi-annular shape and projects inward from an inner surface of the first bearing. The first projection portion supports the first boss slidably. The second projection portion is formed in a semi-annular shape and projects inward from an inner surface of the second bearing. The second projection portion supports the second boss slidably. The first insertion opening is defined between one circumferential end and an other circumferential end of the first projection portion. The first insertion opening is open to a radial direction of the first projection portion. The second insertion opening is defined between one circumferential end and an other circumferential end of the second projection portion. The second insertion opening is open to the radial direction to which the first insertion opening is open. The first projection portion and the second projection portion partially cover the first boss and the second boss, respectively, in a circumferential direction of the first boss and the second boss.

A method for assembling the intake control valve includes (i) placing the first boss and the second boss on the first projection portion and the second projection portion, respectively, through the first insertion opening and the second insertion opening, respectively, (ii) inserting the shaft to the first bearing portion, the first boss, the connecting portion, the second boss, and the second bearing portion, in this order, and (iii) coupling the valve and the shaft to rotate integrally with each other.

According to the intake control valve and the method for assembling the intake control valve, the central axis of the first and second bosses and the central axis of the first and second bearing portions can easily coincide with each other. Furthermore, the first and second projection portions can hold the valve while the central axis of the first and second bosses and the central axis of the first and second bearing portions coincide with each other. Therefore, the shaft can easily be inserted to the connecting portion, the first and second bosses, and the first and second bearing portions. In the result, the number of components and the assembling works can be reduced, and the manufacturing cost can be reduced.

DETAILED DESCRIPTION

A first embodiment will be described referring toFIGS. 1 to 5.

A control device for an internal combustion engine (i.e., an engine control system) of the present embodiment has a variable intake system for the internal combustion engine (i.e., an engine: E/G). In the variable intake system, a length of an intake passage is changed depending on an operation condition of the engine.

The variable intake system has a surge tank providing a passage communicated with a combustion chamber of a cylinder of the engine and an intake control valve disposed in the surge tank.

The surge tank is integrally provided with an intake manifold and is located at an upstream side of the intake manifold having intake branch pipes. Specifically, first intake branch-pipes and second intake branch-pipes are connected to the surge tank. The surge tank has a partition wall separating an inside of the surge tank into two chambers, a first surge-tank chamber and a second surge-tank chamber.

The intake control valve has a valve body1made of synthetic resin and disposed integrally with the partition wall in the surge tank. The valve body1has a pair of valve seats, a valve seat2and a valve seat3, that are integrally formed with each other at a specified portion of the valve body1. As show inFIG. 2, each of the valve seat2and the valve seat3includes a space4passing through the valve seat2and the valve seat3to communicate with a combustion chamber of a cylinder of the engine.

The intake control valve further has a valve part, a shaft6, an actuator7, and a return spring (not shown). The valve part is a butterfly valve5according to the present embodiment. The butterfly valve5is moved to separate from the valve seats2,3so as to open the space4or moved to fit the valve seats2,3so as to close the space4. The shaft is supported to rotate integrally with the butterfly valve5. The actuator operates the shaft6to open or close the butterfly valve5. The return spring biases the butterfly valve5in an opening direction or a closing direction. An electric control unit (i.e., an ECU) (not shown) controls energization of a motor that is a power source for the actuator7such that an opening degree of the butterfly valve5is set to a target opening degree depending on an engine operation condition. For example, the opening degree is set to a fully closing degree, fully open degree, or intermediately open degree.

Intake air (i.e., intake) in the first surge-tank chamber is supplied to the combustion chamber of the cylinder through the first intake branch-pipe. The cylinder is one of cylinders of the engine, the combustion chamber is one of combustion chambers, and the first intake branch-pipe is one of the first intake branch-pipes. The number of the combustion chamber and the number of the first intake branch-pipes, respectively, is the same as the number of the cylinders. An inside of the first intake branch-pipe defines a first branch passage11communicated with the first surge-tank chamber.

Intake air (i.e., intake) in the second surge-tank chamber is supplied to the combustion chamber of the cylinder through the second intake branch-pipe. The second intake branch-pipe is one of second intake branch-pipes, and the number of the second intake branch-pipes is the same as the number of the cylinders. An inside of the second intake branch-pipe defines a second branch passage12communicated with the second surge-tank chamber.

A length of the first branch passage11is longer than a length of the second branch passage12.

Instead of forming the first branch passage11and the second branch passage12to be different from each other in length, the first branch passage11and the second branch passage12may be formed to be different from each other in cross-sectional area. In such a case, a cross-sectional area of the first branch passage11is smaller than a cross-sectional area of the second branch passage12.

The variable intake system improves an output torque of engine. Specifically, a length of a passage from the space4of the partition wall that is disposed in the surge tank to an intake port of the cylinder is changed depending on the operation condition (i.e., an operation state) of the engine. Accordingly, pulsation effect and inertia supercharging effect of intake air occurring in the intake passage of the engine can be used effectively.

The inertia supercharging effect is a supercharging effect with which a greater amount of intake air is drawn into the combustion chamber by using inertial force occurring due to pulsation of the intake air that is drawn into the combustion chamber.

As described above, the intake control valve has the valve body1including the valve seats2,3, the butterfly valve5, the shaft6, and the actuator7. The butterfly valve5is one of butterfly valves.

The butterfly valve5is a plate valve having a rectangular shape and opening or closing the space4. Furthermore, the butterfly valve5is a rotation-type valve. The butterfly valve5is made of synthetic resin and is seamlessly formed in a specified shape. The butterfly valve5is coupled with the shaft6.

The butterfly valve5rotates relative to the partition wall of the surge tank (i.e., the valve body1) such that the opening degree of the butterfly valve5is varied within a range between the fully closing degree and the fully open degree. At the fully closing degree, the butterfly valve5is at a fully closing position where the butterfly valve5fully closes the second branch passage12. At the fully open degree, the butterfly valve5is at a fully open position where the butterfly valve5fully opens the second branch passage12.

As shown inFIG. 2, the butterfly valve5includes a periphery portion13and a periphery portion14extending along a peripheral direction of the butterfly valve5. The periphery portions13,14form an annular band shape, in other words, a rounded generally-rectangular shape. The periphery portions13,14include valve through-holes15passing through the periphery portions13,14in a thickness direction of the periphery portions13,14perpendicular to both of a longitudinal direction and a short direction of the butterfly valve5. The valve through-holes15are arranged one after another in the peripheral direction. The periphery portion13has an elastic sealing part16attached (i.e., fixed) thereto, and the periphery portion14has an elastic sealing part17attached (i.e., fixed) thereto.

The elastic sealing part16and the elastic sealing part17are seamlessly formed with each other. As shown inFIG. 5, each of the elastic sealing parts16,17includes elastic covering portions21,22,23covering an outer periphery portion of the butterfly valve5. The elastic covering portion21is located on a first surface18, the elastic covering portion22is located on a second surface19, and the elastic covering portion23is located on a third surface perpendicular to the first surface18and the second surface19. The first surface18is opposite to the second surface19with respect to the third surface in the thickness direction.

The elastic sealing part16and the elastic sealing part17, respectively, further includes elastic coupling portions24and a seal lip25.

The elastic coupling portions24are filled in the valve through-holes15, respectively. The elastic covering portion21and the elastic covering portion22are coupled with each other through the elastic coupling portions24.

The seal lip25has a V-shape in cross-section and extends in the peripheral direction of the butterfly valve5. When the intake control valve is located at the fully-closing position, the seal lip25gas-tightly seals a clearance provided between the valve seats2,3and the periphery portions13,14.

The butterfly valve5has a connecting portion that is located on a central axis of the butterfly valve5extending in the longitudinal direction and that extends in an axial direction of the shaft6. The connecting portion includes through holes26,27,28having a rectangular shape in cross-section and fitting grooves31,32,33having a generally-square U-shape in cross-section. The shaft6is inserted into the through holes26,27,28and the fitting grooves31,32,33from one side to an other side in the axial direction of the shaft6.

The fitting grooves31,32,33extend in the axial direction, and a fitting portion45(that will be described after) of the shaft6is fitted into the fitting grooves31,32,33. The fitting grooves31,32are open at a center portion of the first surface18on a rotation axis of the butterfly valve5and recessed toward the second surface19that faces the first surface18in the thickness direction. The fitting grooves31,32are, in other words, first-side fitting grooves31,32. The fitting groove33is open at a center portion of the second surface19on the rotation axis and recessed toward the first surface18that faces the second surface19in the thickness direction. The fitting groove33is, in other words, a second-side fitting groove33.

The fitting grooves31,32,33are partially located in swelling portions34,35,36, for example, as shown inFIG. 2. The swelling portions34,35,35expand from the first surface18or the second surface19in the thickness direction, and have an arch shape in cross-section perpendicular to the axial direction.

The through hole26passes through the swelling portion34. The through hole27passes through the swelling portion35and is open in the axial direction at an end of the swelling portion35adjacent to the swelling portion34. The through hole28passes through the swelling portion36and is open in the axial direction at an end of the swelling portion36adjacent to the swelling portion34.

The fitting grooves31,32,33partially include press-fitting grooves37,38at a specified portion in the fitting grooves31,32,33in the axial direction. The fitting portion45of the shaft6is press-fitted into the press-fitting grooves37,38to be fastened thereto. The press-fitting grooves37,38include bottom surfaces located below the fitting grooves31,32,33, respectively, and a clearance is defined between the bottom surfaces and the fitting portion45. When scraps of synthetic resin are provided by press-fitting the shaft6, the scraps of synthetic resin are held in the clearance.

The connecting portion has a cylindrical boss (i.e., a first boss)41and a cylindrical boss (i.e., a second boss)42that are formed in a cylindrical shape. The first boss41is located at an end of the connecting portion in the axial direction (i.e., a rotation axial direction) integrally with the connecting portion. The second boss42is located at an other end of the connecting portion in the axial direction integrally with the connecting portion.

An outer surface of the first boss41and an outer surface of the second boss42define a cylindrical surface.

The first boss41includes a first-boss hole43passing through the first boss41concentrically in the axial direction (i.e., a central axial direction). The first-boss hole43has a rectangular shape in cross-section, and the shaft6is inserted in the first-boss hole43. The second boss42includes a second-boss hole44passing through the second boss42concentrically in the axial direction. The second-boss hole44has a rectangular shape in cross-section, and the shaft6is inserted in the second-boss hole44. The first-boss hole43and the second-boss hole44are concentrically with the through holes26,27,28in the axial direction.

The shaft6extends straight in the axial direction. The shaft6is a polygonal cross-section shaft that has a polygonal shape such as a square shape in cross-section perpendicular to the axial direction. The shaft6is made of steel according to the present embodiment.

The shaft6includes a fitting portion45provided integrally with the shaft6. The fitting portion45fits the press-fitting grooves37,38and is coupled with the press-fitting grooves37,38. The fitting portion45passes through the first-boss hole43and the second-boss hole44. The fitting portion45has a first protruding portion51and a second protruding portion52at both ends of the fitting portion45in the axial direction. The first protruding portion51protrudes from an end surface of the first boss41in the axial direction outwardly from the butterfly valve5in the axial direction. The second protruding portion52protrudes from an end surface of the second boss42in the axial direction outwardly from the butterfly valve5in the axial direction.

The shaft6includes one end portion (i.e., the first protruding portion51) and an other end portion (i.e., the second protruding portion52) in the axial direction. The one end portion of the shaft6is housed rotatably in the first bearing hole55, and the other end portion of the shaft6is housed rotatably in the second bearing hole56.

The first protruding portion51has an end that protrudes outward from the partition wall of the surge tank, in other words, from the valve body1. The end of the first protruding portion46is drivingly connected to the actuator7. The second protruding portion52is formed in a circular shape in cross-section and is directly supported by a wall surface of the second bearing hole56.

The actuator7has a motor and a gear reducer. The motor generates power for opening or closing the butterfly valves5due to electric power supplied to the motor. The gear reducer reduces a rotation speed of the motor via two stages to be a specified reduction ratio.

The gear reducer has a pinion gear fixed to an output shaft of the motor, a middle gear engaged with the pion gear, and an output gear engaged with the middle gear. The output gear is connected to the shaft6to rotate integrally with the shaft6.

The motor is electrically connected to an exterior power source (e.g., a battery) that is mounted in a vehicle such as a car, through a motor driving circuit that is electrically controlled by the ECU.

The ECU has a microcomputer including at least CPU, ROM, and RAM.

In the ECU, an A/D convertor converts output signals from various sensors such as a crank angle sensor, an accelerator-opening sensor, a throttle opening sensor, a rotation angle detector, a coolant temperature sensor, and an air flow meter, from analog to digital. The converted output signals are input to the microcomputer. The various sensors configure an operation-state detecting device detecting an operation state of the engine.

When an ignition switch is on, in other words, in an IG-ON state, the ECU controls energization of the actuator7, especially, the motor, based on a control program memorized in a memory such as the ROM.

Specifically, the ECU calculates an engine rotation speed (i.e., an engine speed: NE) based on an NE pulse that is an output signal from the crank angle sensor. Subsequently, the ECU calculates a target opening degree of the butterfly valve5corresponding to the engine speed. Then, the ECU feedback-controls a power supply so as to eliminate a deviation between an actual opening degree of the butterfly valve5that is output from the valve opening sensor and the target opening degree.

The valve body1of the present embodiment will be described hereafter referring toFIGS. 1 to 4.

The valve body1is the partition wall in the surge tank. The valve body1has the valve seats2,3that are formed integrally with the valve body1, and the space4is defined by the valve seats2,3. The valve seat2has a periphery portion to which the elastic sealing part16attached to the periphery portion13of the butterfly valve5fits tightly. The valve seat3has a periphery portion to which the elastic sealing part17attached to the periphery portion14of the butterfly valve5fits tightly. The valve seats2,3define an opening periphery of the space4. The space4passes through the valve seats2,3in a flow direction of intake air.

The valve body1has a first bearing portion53supporting the first protruding portion51rotatably and a second bearing portion54supporting the second protruding portion52rotatably. The first bearing portion53is a specified distance separated from the second bearing portion54in the axial direction such that the first bearing portion53and the second bearing portion54face to each other. In the present embodiment, the specified distance is equal to a length of the space4in a longitudinal direction (i.e., the axial direction).

The first bearing hole55of the first bearing portion53passes through the first protruding portion51in the axial direction. The second bearing hole56of the second bearing portion54is a bottomed hole.

The valve body1has a first projection portion61and a second projection portion62. The first projection portion61is formed in a semi-annular shape and projects inward from an inner surface of the first bearing portion53. The second projection portion62is formed in a semi-annular shape and projects inward from an inner surface of the second bearing portion54. The first projection portion61includes a first concave portion63that slidably supports the first boss41. The second projection portion62includes a second concave portion64that slidably supports the second boss42. In other words, the first boss41and the second boss42are placed slidably on the first concave portion63and the second concave portion64, respectively.

The valve body1further has a first insertion opening65and a second insertion opening66. The first insertion opening65is defined between one circumferential end and an other circumferential end of the first projection portion61. The second insertion opening66is defined between one circumferential end and an other circumferential end of the second projection portion62. The first insertion opening65is open to a radial direction of the first projection portion61that is opposite from a midpoint of an arc portion of the first projection portion61. The second insertion opening66is open to a radial direction of the second projection portion62that is opposite from a midpoint of an arc portion of the second projection portion62. The first insertion opening65and the second insertion opening66have a semi-annular shape and are open to the same direction.

The first projection portion61fills and seals a clearance A that is defined between the end surface of the first boss41and an end-wall surface defining the space4in the axial direction and is formed in a semi-annular shape. The second projection portion62fills and seals a clearance B that is defined between the end surface of the second boss42and an other end-wall surface defining the space4in the axial direction and is formed in a semi-annular shape.

The first concave portion63extends from the first insertion opening65to an inner center area of the first projection portion61. The second concave portion64extends from the second insertion opening66to an inner center area of the second projection portion62. The first concave portion63includes an inner surface defining a first concave surface that has a specified radius of curvature centering a rotation axis (i.e., the central axis) of the butterfly valve5. The second concave portion64includes an inner surface defining a second concave surface that has a specified radius of curvature centering the rotation axis of the butterfly valve5.

The first projection portion61has a first guide portion67at a circumferential end of the first projection portion61. The first guide portion67has a flat plate shape extending in a tangential direction of the first concave surface. The second projection portion62has a second guide portion68at a circumferential end of the second projection portion62. The second guide portion68has a flat plate shape extending in a tangential direction of the second concave surface. The one circumferential end and the other circumferential end of the first projection portion61is in a generally 180-degree range in a circumferential direction of the first and second projection portions61,62. That is, a virtual line between the one circumferential end and the other circumferential end of the first projection portion61is generally a straight line. The one circumferential end and the other circumferential end of the second projection portion62is in a generally 180-degree range in the circumferential direction of the first and second projection portions61,62. That is, a virtual line between the one circumferential end and the other circumferential end of the second projection portion62is generally a straight line.

The first guide portion67may be located at the one circumferential end or the other circumferential end of the first projection portion61, and the second guide portion68may be located at the one circumferential end or the other circumferential end of the second projection portion62. Alternatively, the first guide portion67may be located at both of the one circumferential end and the other circumferential end, and the second guide portion68may be located at both of the one circumferential end or the other circumferential end of the second projection portion62. Either way, the first guide portion67extends linearly in the tangential direction of the first concave surface, and the second guide portion68extends linearly in the tangential direction of the second concave surface.

A method for assembling the intake control valve for the variable intake system, according to the present embodiment, will be described hereafter.

The first boss41is placed on the first projection portion61through the first insertion opening65, and the second boss42is placed on the second projection portion62through the second insertion opening66. Specifically, the first boss41is placed on the inner surface (i.e., the first concave surface) of the first concave portion63, and the second boss42is place on the inner surface (i.e., the second concave surface) of the second concave portion64.

In a state where the first and second bosses41,42are placed on the first and second projection portions61,62, respectively, a central axis of the through-holes26,27,28, a central axis of the fitting grooves31,32,33, a central axis of the first-boss hole43and the second-boss hole44, and a central axis of the first and second bearing holes55,56coincide with each other. That is, the central axis of the butterfly valve5, a central axis of the first and second bosses41,42, and a central axis of the first and second bearing portions53,54coincide with each other.

The shaft6is inserted from an outside of the first bearing portion53adjacent to the actuator7to the first bearing portion53, the first boss41, the connecting portion, the second boss42, and the second bearing portion54, in this order. For example, the shaft6is inserted such that a tip of the second protruding portion52is inserted ahead. The shaft6is inserted to the connecting portion in the following order of: the first bearing hole55; the first-boss hole43: the through hole27; the fitting groove31; an opening of the through hole26; the fitting groove33; an other opening of the through hole26; the fitting groove32; the through hole28; the second-boss hole44; and the second bearing hole56. Then, the fitting portion45of the shaft6is press-fitted to the press-fitting groove37included in the fitting groove31, the press-fitting groove38included in the fitting groove32, and the press-fitting groove (not shown) included in the fitting groove33, at a second step.

Thus, since the fitting portion45is tightly fixed and supported at a specified position in the axial direction by press-fitting, the butterfly valve5is coupled with the shaft6to be able to rotate integrally with the shaft6.

The variable intake system according to the present embodiment operates as follows.

In the variable intake system, the butterfly valve5is fully opened when the engine is operated under a high-load-low-speed operation condition, and is fully closed when the engine is operated under a low-load-high-speed operation condition. In the result, a length of a passage through which intake air is supplied to the combustion chamber is changed. Thus, fuel charging efficiency can be secured at any rotation speed within an entire rotation-speed range of the engine by using the inertia supercharging effect.

When intake air leaks in a case where the butterfly valve5is fully closed, the inertia supercharging effect is reduced, and the intake control valve cannot improve the fuel charging efficiency.

According to the intake control valve of the present embodiment, sealing effect can be improved in the case where the butterfly valve5is fully closed.

As described above, the valve body1has the first and second projection portions61,62and the first and second insertion openings65,66. The first projection portion61having the semi-annular shape is located inside of the first bearing portion53so as to cover the first boss41partially in the circumferential direction. The second projection portion62having the semi-annular shape is located inside of the second bearing portion54so as to cover the second boss partially in the circumferential direction. The first insertion opening65is defined between the one circumferential end and the other circumferential end of the first projection portion61and is open to the radial direction of the first projection portion61. The second insertion opening66is defined between the one circumferential end and the other circumferential end of the second projection portion62and is open to the radial direction.

Accordingly, the first boss41is placed on the first concave surface of the first projection portion61through the first insertion opening65from an outside of the valve body1. The second boss42is placed on the second concave surface of the second projection portion62through the second insertion opening66from an outside of the valve body1. Thus, the central axis of through-holes26,27,28, the central axis of the fitting grooves31,32,33, the center axis of the first-boss hole43and the second-boss hole44, and the central axis of the first and second bearing holes55,56can easily coincide with each other.

Furthermore, the first and second projection portions61,62can support the butterfly valve5in a state where the central axis of the first-boss hole43and the second-boss hole44and the central axis of the first and second bearing holes55,56coincide with each other. In such a state, the central axis of the first-boss hole43and the second-boss hole44and the central axis of the first and second bearing holes55,56coincide with the rotation axis of the butterfly valve5. Accordingly, the shaft6can easily be inserted to the connecting portion, the first and second bosses41,42, and the first and second bearing portions53,54, and the number of components and a number of assembling works can be reduced. Therefore, manufacturing cost can be reduced.

The rotation axis of the butterfly valve5is located inside of the through-holes26,27,28and the fitting grooves31,32,33. Specifically, according to the present embodiment, the through-holes26,27,28and the fitting grooves31,32,33are located concentrically with the rotation axis of the butterfly valve5. The fitting portion45is inserted to the through-holes26,27,28and the fitting grooves31,32,33. The fitting grooves31,32,33partially includes the press-fitting grooves37,38to which the fitting portion45is press-fitted.

The central axis of the first and the second bosses41,42is located inside of the first-boss and second-boss holes43,44, respectively. Specifically, according to the present embodiment, the first boss41and the first through-hole43are located concentrically with each other, and the second boss42and the second through-hole44are located concentrically with each other.

The central axis of the first and the second bearing portions53,54is located inside of the first and second bearing holes55,56, respectively. Specifically, according to the present embodiment, the first bearing portion53and the first bearing hole55are coaxially with each other, and the second bearing portion54and the second bearing hole56are coaxially with each other. According to the present embodiment, the first bearing hole55of the first bearing portion53passes through the first protruding portion51in the axial direction. The second bearing hole56of the second bearing portion54is a bottomed hole. However, the first bearing hole55may be a bottomed hole, and the second bearing portion54may pass through the second protruding portion52in the axial direction.

The first boss41and the second boss42are located on the inner surfaces of the first and second projection portions61,62, respectively. Therefore, the first and second concave surfaces of the first and second projection portions61,62can support the butterfly valve5in the case where the central axis of the through-holes26,27,28, the central axis of the fitting grooves31,32,33, the central axis of the first-boss and second-boss holes43,44, and the central axis of the first and second bearing holes55,56coincide with each other.

According to the present embodiment, the first and second projection portions61,62include the first and second insertion openings65,66, respectively. The first and second insertion openings65,66are opened to the same direction. The valve body1includes the first concave portion63and the second concave portion64having a semi-annular shape. The first concave portion63extends from the first insertion opening65to an inner center area of the first projection portion61. The second concave portion64extends from the second insertion opening66to an inner center area of the second projection portion62. The first concave portion63includes the first concave surface having the specified radius of curvature that centers the rotation axis or the central axis of the butterfly valve5. The second concave portion64includes the second concave surface having the specified radius of curvature that centers the rotation axis or the central axis of the butterfly valve5.

Accordingly, the first and second bosses41,42are located on the inner surface of the first and second projection portions61,62, respectively, through the first and second insertion openings65,66, respectively. In other words, the first and second bosses41,42are located on the inner surfaces of the first and second concave surfaces of the first and second concave portions63,64, respectively. Therefore, the central axis of the first and second bosses41,42can easily coincide with the central axis of the first and second bearing portions53,54.

Furthermore, the inner surfaces of the first and second concave portions63,64are formed in a shape that fits a shape of an outer surface of the shaft6. Accordingly, the first and second bosses41,42can slidably move on the inner surface of the first and second projection portions61,62, respectively, in a rotation direction when the butterfly valve5is operated to be open or closed. In other words, the first and second bosses41,42can slidably move on the inner surface of the first and second concave portions63,64, respectively, in a rotation direction when the butterfly valve5is operated to be open or closed.

According to the present embodiment, the first projection portion61has the first guide portion67at the circumferential end of the first projection portion61. The first guide portion67has the flat plate shape extending in the tangential direction of the first concave surface. The second projection portion62has the second guide portion68at the circumferential end of the second projection portion62. The second guide portion68has the flat plate shape extending in the tangential direction of the second concave surface. When the first and second bosses41,42are placed on the inner surfaces of the first and second projection portions61,62, respectively, the first and second guide portions67,68guide the first and second bosses41,42, respectively. Accordingly, the first and second bosses41,42are promptly placed on a center area of the inner surfaces of the first and second concave surfaces of the first and second projection portions61,62, respectively. Therefore, assembling works to attach the first and second bosses41,42to the inner surfaces of the first and second projection portions61,62(i.e., the first and second concave portions63,64), respectively, can be expedited. In the result, productivity of the intake control valve can be improved.

The intake control valve of the present embodiment is assembled through the first step and the second step.

Accordingly, the butterfly valve5can be supported on the first and second concave surfaces of the first and second projection portions61,62in the state where the central axis of the through-holes26,27,28, the central axis of the fitting grooves31,32,33, the central axis of the first-boss and second-boss holes43,44, and the central axis of the first and second bearing holes55,56coincide with each other. Therefore, the shaft6can easily be inserted to the connecting portion, the first and second bosses41,42, and the first and second bearing portions53,54, and the number of components and the assembling works can be reduced. Therefore, manufacturing cost can be reduced.

Conventionally, according to a conventional intake control valve (e.g., an intake control valve described in patent document 1), a clearance having a specified length in the rotation direction is required between a butterfly valve and a wall surface that defines a space of a valve body in the rotation direction. By providing the clearance, a shaft can rotate relative to the valve body. However, the clearance defines a passage through which air leaks when the butterfly valve is fully closed. Accordingly, a leaking amount of the air leaking through the clearance may increase when the butterfly valve5is fully closed.

According to the present embodiment, the first and second projection portions61,62are located on the inner surfaces of the first and second bearing portions53,54, respectively, such that the first and second projection portions61,62so as to reduce the leaking amount of the air when the butterfly valve5is fully closed.

Therefore, the first projection portion61can fill and seal the clearance A that is defined between the end surface of the first boss41and the end-wall surface defining the space4in the axial direction. The second projection portion62can fill and seal the clearance B that is defined between the end surface of the second boss42and the other end-wall surface defining the space4in the axial direction. In the result, the leaking amount of the air when the butterfly valve5is fully closed can be reduced.

An intake control system having an intake control valve, according to a second embodiment, will be described referring toFIGS. 6 to 8.

The butterfly valve5disposed in the intake control valve of the present embodiment has the connecting portion located along the central axis of the butterfly valve5that extends in the longitudinal direction of the butterfly valve5. The connecting portion extends straight in the axial direction of the shaft6. The connecting portion includes the through holes26,27,28having the rectangular shape in cross-section and fitting grooves71,72,73,74having a generally-square U-shape in cross-section. The shaft6is inserted into the through holes26,27,28and the fitting grooves71,72,73,74from one side to an other side in the axial direction of the shaft6.

The through holes26,27,28include a press-fitting hole (i.e., a press-fitting portion)39to which the fitting portion45is press-fitted. Accordingly, the butterfly valve5is fixed to the shaft6, and the shaft6can support the butterfly valve5.

As shown inFIG. 8, the fitting grooves31,32,33are located inside of the swelling portions34,35,36that expand to have the arch shape. A first insertion hole is defined between the swelling portion34and the swelling portion35in the axial direction, and the fitting portion45of the shaft6is located inside of the first insertion hole. The first insertion hole has a rectangular shape in cross-section perpendicular to the axial direction. A second insertion hole is defined between the swelling portion34and the swelling portion36in the axial direction, and the fitting portion45is located inside of the second insertion hole. The second insertion hole has a rectangular shape in cross-section perpendicular to the axial direction.

The fitting grooves71,72,73,74extend in the axial direction, and the fitting portion45is press-fitted to the fitting grooves71,72,73,74. The fitting grooves71,72,73,74are partially located inside of the swelling portion34,35,36that expand from the first surface18or the second surface19in the thickness direction.

The fitting grooves71,72,73,74include press-fitting grooves81,82,83,84, respectively. The fitting portion45is press-fitted to the press-fitting grooves81,82,83,84. The press-fitting grooves81,82,83,84include bottom surfaces located below the fitting grooves71,72,73,74, respectively, and a clearance is defined between the bottom surfaces and the fitting portion45. When scraps of synthetic resin are provided by press-fitting the shaft6, the scraps of synthetic resin are held in the clearance.

The connecting portion has the first boss41and the second boss42that are formed in the cylindrical shape, similar to the first embodiment. The first boss41is located at the end of the connecting portion in the axial direction integrally with the connecting portion. The second boss42is located at the other end of the connecting portion in the axial direction integrally with the connecting portion.

The outer surface of the first boss41and the outer surface of the second boss42define the cylindrical surface. The first boss41includes a first-boss hole43passing through the first boss41concentrically in the axial direction (i.e., a central axial direction). The first-boss hole43has a rectangular shape in cross-section, and the shaft6is inserted in the first-boss hole43. The second boss42includes a second-boss hole44passing through the second boss42concentrically in the axial direction. The second-boss hole44has a rectangular shape in cross-section, and the shaft6is inserted in the second-boss hole44. The first-boss hole43and the second-boss hole44are concentrically with the through holes26,27,28in the axial direction.

Thus, the intake control valve of the present embodiment causes similar effects that are similar to that of the first embodiment.

According to the above embodiments, the actuator7operating the butterfly valve5that is the valve part of the intake control valve is an electric actuator having the motor and the gear reducer. However, the actuator7may be an electromagnetic actuator (i.e., a solenoid actuator) or a negative-pressure type actuator having an electromagnetic negative-pressure control valve or an electric negative-pressure control valve.

According to the above embodiments, the butterfly valve5as the valve part is the plate valve. However, the valve part may be a flap valve, a rotary valve, a poppet valve, a spool valve, or the like.

According to the above embodiments, the intake control valve is used in the variable intake system. However, the intake control valve may be used for an electronic throttle in an intake system that has a throttle valve adjusting a flow rate of intake air to be supplied to an internal combustion engine.

Alternatively, the intake control valve of the above embodiments may be used in an intake control system having a tumble control valve. In the intake control system having the tumble control valve, a linear flow (i.e., a drift) of intake air is caused at one side in an intake port in a height direction of the intake port. For example, when a piston moves in a vertical direction, the linear flow is caused at one side in the intake port in the vertical direction. In the result, a vortex (i.e., a tumble flow) of the intake air that swirls around a swirling axis perpendicular to the vertical direction is caused in a combustion chamber of an internal combustion engine, according to the intake control system having the tumble control valve.

Alternatively, the intake control valve of the above embodiments may be used in an intake control system having a swirl control valve. In the intake control system having the swirl control valve, a linear flow (i.e., a drift) of intake air is caused at one side in an intake port in a width direction of the intake port. For example, when a piston moves in the vertical direction, the linear flow is caused at one side in the intake port in the horizontal direction. In the result, a vortex (i.e., a swirl flow) of the intake air that swirls around a swirling axis parallel with the vertical direction is caused in a combustion chamber of an internal combustion engine, according to the intake control system having the swirl control valve.

According to the above embodiments, multiple plate valves are arranged one after another and connected to each other to move integrally. However, a single valve may work as the multiple plate valves as long as the valve is located in a fluid passage such as an intake passage of an internal combustion engine.

Such changes and modifications are to be understood as being within the scope of the present disclosure as defined by the appended claims.