JP2013194659A - Throttle body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically provide various throttle bodies whose positions of bumping parts differ from each other.SOLUTION: A throttle body 1 includes a throttle shaft 4 which rotates holding a throttle valve 3. The throttle valve 3 is prevented from being rotated by bringing an abutment member 6, which integrally rotates with a valve gear 5, into abutment with a rotation prevention member 7. The valve gear 5 and abutment member 6 are configured to bring their contact faces into contact with each other and are fixed on a throttle shaft 4 with a shaft force given to an axial direction of the throttle shaft 4. Each contact face is a metal face and its surface is roughened.

Description

  The present invention relates to a throttle body that opens and closes an intake passage of an engine.

  Conventionally, such a throttle body is fixed to a throttle shaft that holds an engine intake passage, a throttle valve that opens and closes the intake passage of the engine, a throttle shaft that holds the throttle valve, and the intake of the throttle body. And a valve gear driven to open and close the passage (see, for example, Patent Document 1).

  The valve gear is driven by urging the valve gear in the closing direction with a torsion coil spring and transmitting the driving force of the motor to the valve gear. At that time, in order to prevent the throttle valve from rotating beyond the predetermined opening in the closing direction, when the throttle valve reaches the predetermined opening during the rotation in the closing direction, the abutting portion of the valve gear It comes to abut against a rotation preventing member fixed to the casing.

  For example, as described in Patent Document 1, the valve gear is formed by insert molding in which a metal plate is integrated with a synthetic resin molding material. In this case, the metal plate constitutes a portion for fixing the valve gear to the throttle shaft and the abutting portion described above, and the synthetic resin forms a gear portion of the valve gear. Since the metal plate forms an abutting portion that requires high accuracy, the metal plate is formed of a highly rigid metal.

International Publication No. 01/075506

  When manufacturing various types of throttle bodies in which the position of the abutting portion of the valve gear is different, it is necessary to use a dedicated valve gear having a corresponding abutting portion for each of the various throttle bodies. For example, for a throttle body in which the opening and closing direction of the throttle valve is reversed, it is necessary to use a valve gear in which the abutting portion is located on the opposite side.

  Therefore, it is necessary to design a valve gear in which the position of the abutting portion is different for each type of throttle body. Specifically, in the case of the throttle body of Patent Document 1 above, the metal plate constitutes the abutting portion. Therefore, in order to change the position of the abutting portion, the shape of the metal plate is redesigned and adjusted accordingly. Therefore, it is necessary to design a new mold for forming the valve gear.

  However, when designing the valve gear, each design requires a large amount of money for trial manufacture of the mold and evaluation thereof. This is because the valve gear decelerates the driving force of the motor and transmits it to the throttle shaft, so that it is necessary to form the valve gear as a molded part having excellent strength and precision.

  An object of the present invention is to make it possible to economically provide various throttle bodies having different abutting portions in view of the problems of the conventional technology.

  A throttle body according to the present invention includes an engine intake passage, a throttle valve for opening and closing the engine intake passage, a throttle shaft that holds and rotates the throttle valve, and is fixed to the throttle shaft. The throttle valve rotates in the closing direction beyond a predetermined opening degree by contact with the valve gear driven to open and close the intake passage, the abutting member that rotates integrally with the valve gear, and the abutting member The throttle shaft includes a fixed portion having a predetermined cross-sectional shape, and the valve gear and the abutting member are in contact with each other, and the fixed portion. Each having a shape corresponding to the cross-sectional shape of each of the through holes, and the valve gear and the valve gear. The abutting member is fixed to the fixed portion by fitting between the fixing portion and each fixing hole, and an axial force applied to the valve gear and the abutting member in the axial direction of the throttle shaft. Each of the contact surfaces in contact with the metal surface is a metal surface, and one or both of them are processed to roughen the surface.

  According to the present invention, the valve gear and the abutting member for preventing its rotation are configured as separate members. For this reason, various throttle bodies having different abutting positions with the rotation preventing portion of the abutting member are used for the valve gear, and only the abutting member is used corresponding to the abutting position. Can be configured.

  Therefore, it is possible to easily provide various throttle bodies having different contact positions, that is, positions of the abutting portions where the abutting members abut against the rotation preventing portions.

  However, each contact surface of the valve gear and the abutting member is a metal surface, and one or both of them are processed to roughen the surface, and the axial force of the throttle shaft is applied from the outside in the axial direction. Therefore, the static friction coefficient of each contact surface and the drag acting perpendicularly between the contact surfaces are very large.

  For this reason, moments acting in opposite directions on the valve gear and the abutting member when the abutting member abuts against the rotation preventing portion cancel each other through the frictional force between the contact surfaces. That is, even if the valve gear and the abutting member are separate members, the moment acting on each of them does not separately act on the fixed portion of the throttle shaft to apply a large force.

  Thereby, it can avoid that each fixing hole of a valve gear and an abutting member receives a big force from a fixing | fixed part, and durability falls. This effect is obtained by the above-described processing for roughening the surface and the axial force of the throttle shaft.

  In order to obtain this effect, it is not necessary to increase the area of the contact surface of the valve gear and the abutting member or add other parts. Moreover, it is not necessary to enlarge each fixing hole in order to reduce a large force applied to each fixing portion. Therefore, it is possible to easily provide various throttle bodies having different contact positions while reducing the size of the throttle body and reducing the manufacturing cost.

  In the present invention, the valve gear may be formed by resin molding in which a metal member constituting the through hole and the contact surface is inserted.

  In this case, as described above, since the function of the conventional abutting portion is performed by the abutting member, the abutting portion does not exist in the inserted metal member. For this reason, the structure of the mold used for insert molding may be a structure that avoids interference with such an abutting portion, or there is a risk that burrs will occur between the mold and the metal member at the part where interference is avoided. The valve gear can be easily formed without causing the occurrence of the above.

  In the present invention, the throttle body constitutes a multiple throttle, and the abutting member is connected to a coupling lever fixed to the throttle shaft of another throttle body constituting the multiple throttle. You may provide the connection part for making it do.

  According to this, it is possible to eliminate the need for a dedicated connecting lever that has been adopted for interlocking the throttle shafts of the adjacent throttle bodies in the conventional throttle body. Therefore, it is possible to further reduce the size of the throttle body and reduce the manufacturing cost.

It is a perspective view which shows the principal part of the throttle body which concerns on one Embodiment of this invention. It is a disassembled perspective view which shows the attachment structure of the valve gear with respect to the throttle shaft of the throttle body of FIG. It is explanatory drawing of the moment provided to the valve gear and butting member of the throttle body of FIG. FIG. 2 is a perspective view showing a state in which a butting member of the throttle body of FIG. 1 is connected to a connecting lever of an adjacent throttle body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The throttle body according to the embodiment constitutes a first throttle body among the first to third three throttle bodies forming a triple throttle.

  As shown in FIG. 1, a throttle body 1 according to the embodiment is fixed to a throttle valve 3 for opening and closing an intake passage 2 of an engine, a throttle shaft 4 that rotates while holding the throttle valve 3, and the throttle shaft 4. The valve gear 5, the butting member 6 that rotates integrally with the valve gear 5, and the rotation prevention member 7 as a rotation prevention unit that prevents the throttle valve 3 from rotating beyond the predetermined opening degree in the closing direction. .

  The throttle shaft 4 is rotatably supported by a cylindrical member 8 constituting the intake passage 2 so that the throttle valve 3 can open and close the intake passage 2.

  The valve gear 5 and the abutting member 6 are fixed to the throttle valve 3 by a spring washer 9 and a nut 10 at one end of the throttle shaft 4 protruding from the cylindrical member 8. That is, the valve gear 5 and the abutting member 6 are fixed in the axial direction with respect to the throttle valve 3 by the axial force of the throttle shaft 4 applied from the outside in the axial direction.

  The valve gear 5 is driven to open and close the intake passage 2 by the throttle valve 3. The valve gear 5 is driven by the motor 11 via the intermediate gear 12. The intermediate gear 12 includes a small-diameter gear 13 having a smaller number of teeth and a large-diameter gear 14 having a larger number of teeth. The large diameter gear 14 meshes with a pinion gear 15 provided on the output shaft of the motor 11, and the small diameter gear 13 meshes with the valve gear 5.

  The valve gear 5 is applied with an urging force in a direction in which the throttle valve 3 is rotated in the closing direction (hereinafter simply referred to as “closing direction”). The biasing force is applied by a torsion spring 16 that is interposed between the valve gear 5 and the casing of the throttle body 1.

  The valve gear 5 is driven by a driving force from the motor 11 in a state where a biasing force in the closing direction by the torsion spring spring 16 is applied. At this time, the valve gear 5 is driven at a rotational speed reduced with respect to the rotational speed of the motor 11 via the intermediate gear 12 or the like.

  The abutting member 6 is formed by processing a metal plate. In the vicinity of the tip, which is the end opposite to the center of rotation of the abutting member 6, the thrust that abuts against the rotation prevention member 7 when the throttle valve 3 rotates in the closing direction and reaches the aforementioned predetermined opening degree. A contact portion 17 and a connecting portion 18 for connecting to the throttle shaft of the second throttle body adjacent to the throttle body 1 are formed.

  The abutting portion 17 and the connecting portion 18 are located on the radially outer side from the throttle shaft 4, which is the central axis of rotation of the abutting member 6, and as far as the teeth of the valve gear 5. The abutting portion 17 is formed as a bent portion having a shape such that the protruding piece at the tip of the abutting member 6 is bent toward the intake passage 2 side. The edge of the bent portion on the closing direction side abuts against the rotation prevention member 7.

  The connecting portion 18 includes two bent portions 19 and 20 having a shape such that two protruding pieces on both sides of the tip portion of the abutting member 6 are bent in the opposite direction to the abutting portion 17. One bent portion 19 is provided with a screw hole 21 for connecting the connecting portion 18 to a connecting lever fixed to the throttle shaft of the adjacent second throttle body.

  The rotation preventing member 7 is provided on the casing of the throttle body 1. When the abutting portion 17 of the abutting member 6 contacts the rotation preventing member 7, the rotation of the throttle valve 3 exceeding the predetermined opening degree is prevented.

  FIG. 2 is an exploded perspective view showing a mounting structure of the valve gear 5 and the abutting member 6 with respect to the throttle shaft 4. As shown in FIG. 2, a small-diameter portion 22 having a smaller diameter than an adjacent central portion is provided at an end portion on one end side of the throttle shaft 4 over the end edge. A bearing 23 for rotatably supporting the throttle shaft 4 on the cylindrical member 8 (see FIG. 1) is fitted to the peripheral surface of the end portion of the small diameter portion 22 opposite to the end edge.

  Moreover, the edge part side of the small diameter part 22 becomes the fixing | fixed part 24 which has a predetermined cross-sectional shape. This cross-sectional shape has a shape in which both sides of a circle are cut symmetrically by two parallel lines. That is, the fixed portion 24 has two planes that are parallel to and symmetrical to the axis of the throttle shaft 4. On the distal end side of the fixing portion 24, a male screw 25 is provided over the edge.

  The valve gear 5 and the abutting member 6 are each provided with a fixing hole 26 and a fixing hole 27 penetrating in the axial direction having a shape corresponding to the cross-sectional shape of the fixing portion 24 on the rotation axis. The valve gear 5 and the abutting member 6 are provided with a contact surface 28 and a contact surface 29 that contact each other. The valve gear 5 is formed by resin molding with the metal member 30 inserted. The metal member 30 constitutes the fixing hole 26 and the contact surface 28 of the valve gear 5.

  The contact surface 28 is an annular region having a radial width extending from the inner edge side adjacent to the fixing hole 26 to the vicinity of the outer edge side adjacent to the resin portion of the valve gear 5 on the abutting member 6 side of the metal member 30. Occupy. The contact surface 29 also occupies an annular region with a corresponding size and shape.

  One or both of the contact surface 28 and the contact surface 29 are processed to roughen the surface. This processing is performed by, for example, rough surface processing in which fine and hard particles are sprayed at high pressure. In this case, even when the metal member 30 is in an uncut material state, after the metal member 30 is formed, or even after the valve gear 5 is formed, the contact surface 28 can be easily formed. Processing to roughen the surface can be performed.

  Moreover, the process which roughens the surface can also be performed by knurling. In this case, when the valve gear 5 or the abutting member 6 is processed into a flat plate shape or formed by injection molding, the contact surface 28 or the contact surface 29 is pressed or molded by a mold having an uneven shape, etc. The surface of the contact surface 28 or the contact surface 29 can be easily roughened.

  The surface roughness of the contact surface 28 and the contact surface 29 is, for example, 6 μm or more on an average of 10 points. In this case, the tightening torque of the nut 10 that fastens the valve gear 5 and the abutting member 6 to the throttle shaft 4 is 4 Nm or more if the nominal diameter of the screw is M7.

  When attaching the valve gear 5 and the butting member 6 to the throttle shaft 4, first, the bearing 23 and the cylindrical spacer 31 are fitted on the outer periphery of the small diameter portion 22 in this order. Next, the fixing holes 24 and the fixing holes 26 and 27 of the abutting member 6 are fitted in this order on the outer periphery of the fixing portion 24. Then, the nut 10 is fastened to the male screw 25 via the spring washer 9.

  As a result, the valve gear 5 and the abutting member 6 are fixed in the circumferential direction by fitting the fixing portion 24 and the fixing holes 26 and 27 to the throttle shaft 4. Further, the axial force of the throttle shaft 4 corresponding to the fastening force of the nut 10 and the male screw 25 is applied to the valve gear 5 and the abutting member 6 from the outer side in the axial direction through the spacer 31 and the spring washer 9. Thus, the valve gear 5 and the abutting member 6 are fixed to the throttle shaft 4. This axial force increases the drag between the contact surfaces 28 and 29 and improves the maximum static frictional force.

  An engagement hole 33 for engaging a lower end of a support member 32 described later is provided in the bent portion 20 of the connecting portion 18 of the abutting member 6.

  FIG. 3 is an explanatory diagram of moments applied to the valve gear 5 and the abutting member 6. As shown in FIG. 3, when the valve gear 5 is driven in the closing direction Y <b> 1 by the torsion spring spring 16 (see FIG. 1) and the power applied via the small diameter gear 13, the abutting portion of the abutting member 6. When 17 hits against the rotation prevention member 7, the throttle valve 3 (see FIG. 1) is prevented from rotating beyond the predetermined opening degree in the closing direction.

  As a result, the throttle valve 3 is accurately positioned with respect to the closed position of the predetermined opening. However, at this time, the driving force F <b> 1 by the small diameter gear 13 and the urging force by the torsion spring spring 16 are applied to the valve gear 5, and the reaction force F <b> 2 from the rotation preventing member 7 is applied to the abutting portion 17.

  At this time, if the valve gear 5 and the abutting member 6 are fixed only to the throttle shaft 4 in the circumferential direction by the fixing portion 24, the fixing portion 24 is connected to the valve gear 5 from the fixing hole 26 of the valve gear 5. A large moment force A corresponding to the applied driving force F1 or the like is applied. Further, a large moment force B corresponding to the reaction force F <b> 2 from the rotation prevention member 7 is applied to the fixing portion 24 from the fixing hole 27 of the abutting member 6.

  However, as described above, the valve gear 5 and the abutting member 6 are provided to the throttle shaft 4 from the outside in the axial direction via the spacer 31 and the spring washer 9 (see FIG. 2). The moment forces A and B are reduced by the frictional force between the spacer 31 and the valve gear 5 and the frictional force between the butting member 6 and the spring washer 9.

  Further, as described above, the contact surfaces 28 or 29 (see FIG. 2) of the valve gear 5 and the abutting member 6 have a friction coefficient increased by the process of roughening the surface, and correspond to the axial force of the throttle shaft 4. The maximum static frictional force is increased by drag. For this reason, due to the frictional force between the contact surfaces 28 and 29, the moment force in the reverse direction due to the driving force F1 and the reaction force F2 is not transmitted to the throttle shaft 4, but is canceled halfway.

  That is, due to the friction between the contact surfaces 28 and 29, the valve gear 5 and the abutting member 6 function as a substantially integrated object mechanically. As a result, the force applied to the throttle shaft 4 by the fixing holes 26 and 27 or the reaction force thereof is a force C smaller than the moment forces A and B. Therefore, the durability of the fixing holes 26 and 27 is not impaired.

  This effect is obtained by roughening the surface applied to each contact surface 28 or 29 and the axial force corresponding to the fastening force of the spring washer 9 and the nut 10. Therefore, in order to obtain this effect, it is not necessary to increase the area of the contact surfaces of the contact surfaces 28 and 29 or add other parts.

  FIG. 4 is a perspective view showing a state in which the abutting member 6 is connected to the connecting lever of the adjacent second throttle body. As shown in FIG. 4, a connecting lever 36 having a connecting piece 35 at the tip is fixed to the end of the throttle shaft 34 of the adjacent second throttle body.

  A screw 37 is screwed into the screw hole 21 (see FIG. 3) of the bent portion 19 in the connecting portion 18 of the abutting member 6 from the outside via a compression coil spring 38a. A support member 32 having a flange-shaped tip is attached to the bent portion 20. The front flange portion is provided so as to protrude inside the bent portion 20 so as to face the front end of the screw 37.

  A compression coil spring 38 b is provided between the flange-shaped portion of the support member 32 and the bent portion 20. The lower end of the support member 32 is engaged with the engagement hole 33 so that the support member 32 is not pulled out by the compression coil spring 38 b and is fixed to the bent portion 20. The support member 32 is supported by the flange-like portion while being displaced according to the screwing amount of the connection piece 35 male screw 25 of the connection lever 36.

  When the throttle shaft 4 and the throttle shaft 34 are in the connected state, the connecting piece 35 of the connecting lever 36 is in a state substantially parallel to the bent portions 19 and 20 in the connecting portion 18 of the abutting portion 17. To position. At this time, the connection piece 35 of the connection lever 36 is sandwiched and supported between the screw 37 and the support member 32.

  In this state, when the throttle shaft 4 is rotated by the motor 11, the driving force is transmitted to the throttle shaft 34 through the valve gear 5, the abutting member 6, and the connecting lever 36. As a result, the throttle shaft 34 rotates in conjunction with the rotation of the throttle shaft 4.

  The phase difference in the opening between the throttle valve 3 that is opened and closed in conjunction with the throttle valve 39 of the second throttle body can be adjusted by the screw 37. That is, when the screwing amount of the screw 37 is changed, the connecting piece 35 of the connecting lever 36 is rotated with respect to the abutting portion 17 by an amount corresponding thereto.

  The support member 32 is displaced following the rotation by the urging force of the compression coil spring 38b. Therefore, the phase difference between the throttle valves 3 and 39 can be adjusted by adjusting the screwing amount of the screw 37.

  As described above, according to the present embodiment, the valve gear 5 and the abutting member 6 for preventing the rotation of the valve gear 5 are constituted by separate members. Various different throttle bodies can be configured by using the same valve gear 5 and using only the abutting member 6 corresponding to the position of the different rotation preventing member 7.

  For example, with respect to the throttle body in which the rotation direction of the valve gear 5 corresponding to the closing direction of the throttle valve 3 is opposite to that in the present embodiment, a new abutting member provided with the abutting portion in the opposite direction on the opposite side is newly provided. You can respond by simply designing. Therefore, various throttle bodies can be provided without requiring a large mold cost for design change and an evaluation cost of the mold.

  Further, since the valve gear 5 has no abutting portion, it can be easily molded by resin molding. For example, if the metal member 30 to be inserted has an abutting part, it is necessary to use a mold that avoids interference with the abutting part. There is a risk that burrs will occur between the mold and the metal member 30. Such difficulty in molding can be avoided.

  Further, the contact surface 28 or 29 of the valve gear 5 or the abutting member 6 is roughened so that the valve gear 5 and the abutting member 6 are fixed by an axial force. Thus, the durability of the fixing holes 26 and 27 can be improved. Further, the effect of improving the durability can be obtained without causing an increase in the size of the throttle body and an increase in the number of parts.

  Moreover, since the connection part 18 was provided in the abutting member 6, the necessity to provide a connection lever separately can be excluded. Furthermore, since the connecting portion 18 is provided with means for adjusting and tuning the phase difference between the slot valves 3 and 39, the necessity for providing such tuning means can be eliminated.

  In addition, this invention is not limited to the above-mentioned embodiment. For example, an embodiment in which the opening / closing direction of the throttle valve 3 is opposite to the case of FIGS. In this embodiment, the abutting portion 17 is provided in the opposite direction on the opposite side of the abutting member 6, and the rotation prevention member 7 is also provided in the opposite direction on the opposite side.

  In this case, when the abutting portion 17 abuts against the rotation preventing member 7, a reaction force opposite to the reaction force F2 in FIG. As a result, the nut 10 that fastens the abutting member 6 is given a moment in the direction of loosening the nut 10 via the spring washer 9 due to the frictional force of the fastening portion.

  However, in this case as well, due to the frictional force generated by the roughening process applied to the surface of each contact surface 28 or 29 and the large drag force acting between each contact surface 28 and 29 due to the axial force of the throttle shaft 4, Since the valve gear 5 and the rotation prevention member 7 are securely fixed to each other and the moment in the direction of loosening the nut 10 is offset, the nut 10 is not loosened.

  Also in this case, the force applied to the fixing holes 26 and 27 is the same small force C for the same reason as described in FIG. 3, thereby deteriorating the durability of the fixing holes 26 and 27. There is nothing.

  DESCRIPTION OF SYMBOLS 1 ... Throttle body, 2 ... Intake passage, 3 ... Throttle valve, 4 ... Throttle shaft, 5 ... Valve gear, 7 ... Rotation prevention member (rotation prevention part), 17 ... Abutting member, 18 ... Connection part, 24 ... Fixed part , 26, 27 ... fixing holes, 28, 29 ... contact surfaces, 30 ... metal members, 36 ... connecting levers.

Claims (3)

The intake passage of the engine,
A throttle valve for opening and closing the intake passage of the engine;
A throttle shaft that rotates while holding the throttle valve;
A valve gear fixed to the throttle shaft and driven to open and close the intake passage with the throttle valve;
An abutting member that rotates integrally with the valve gear;
A rotation blocking portion for blocking the throttle valve from rotating beyond a predetermined opening in the closing direction by contact with the abutting member;
The throttle shaft includes a fixed portion having a predetermined cross-sectional shape,
The valve gear and the abutting member are provided with respective contact surfaces in contact with each other, and respective fixing holes penetrating with a shape corresponding to the cross-sectional shape of the fixing portion,
The valve gear and the abutting member are fixed to the fixing portion by fitting the fixing portion and the fixing holes and an axial force applied to the valve gear and the abutting member in the axial direction of the throttle shaft. ,
Each of the contact surfaces in contact with each other is a metal surface, and one or both of them are processed to roughen the surface.   2. The throttle body according to claim 1, wherein the valve gear is formed by resin molding in which a metal member constituting the contact surface and the fixing hole is inserted. Constructs a multiple throttle,
The said abutting member is provided with the connection part for connecting this abutting member to the connection lever fixed to the throttle shaft of the other throttle body which comprises the said multiple throttle. Throttle body as described in

Images