JP5292331B2 - Intake control device for internal combustion engine - Google Patents

Description

  The present invention includes a synthetic resin throttle body having an intake passage, a pair of cylindrical bearing holders that are insert-molded on the throttle body so as to be coaxially arranged across the intake passage, and the bearing holders. An intake control device for an internal combustion engine comprising a pair of bearings that are press-fitted and held, a valve shaft that is rotatably supported by these bearings, and a throttle valve that is attached to the valve shaft and opens and closes the intake passage by rotation thereof. Regarding improvement.

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

JP 2006-17005 A

  In the conventional intake control device for an internal combustion engine, the inner end surface of the bearing holder exposed in the intake passage is exposed when the inner end of the bearing holder is exposed to the intake passage and the bearing is press-fitted into the bearing holder from the outer end side. The press-fitting receiving jig that supports is installed in the intake passage.

  In such a case, it is possible to prevent the press-fitting load of the bearing to the bearing holder from being applied to the throttle body, and to avoid the separation of the bearing holder from the throttle body.

  However, inserting a press-fitting receiving jig that supports the inner end surface of the bearing holder into the intake passage may damage the inner peripheral surface of the intake passage that has been finished with high accuracy. For this reason, a high degree of consideration is required for the installation of the press-fitting receiving jig in the intake passage, which causes a reduction in production efficiency and makes it difficult to reduce costs.

  The present invention has been made in view of such circumstances. When the bearing is press-fitted into the bearing holder, there is no fear of damaging the inner peripheral surface of the intake passage, and the inner end of the bearing holder is received by the press-fitting receiving jig. An object of the present invention is to provide an intake control apparatus for an internal combustion engine.

  In order to achieve the above object, the present invention comprises a synthetic resin throttle body having an intake passage and a pair of cylindrical inserts formed on the throttle body so as to be coaxially arranged with the intake passage interposed therebetween. A bearing holder, a pair of bearings that are press-fitted and held in these bearing holders, a valve shaft that is rotatably supported by these bearings, and a throttle valve that is attached to the valve shaft and opens and closes the intake passage by its rotation. In the intake control device for an internal combustion engine, the bearing holder is disposed so that the inner end face thereof is located on the radially outer side of the intake passage, and a recess that exposes at least a part of the inner end face is also provided. A press fit that is formed in the throttle body so as to be located radially outside the intake passage and supports the inner end face of the bearing holder when the bearing is press fitted into the bearing holder. That the only tool to be inserted into the recess to the first feature.

  According to the present invention, in addition to the first feature, a portion of the inner end surface of the bearing holder is exposed to the recess so as to be supported by the press-fitting receiving jig, and the remaining portion is exposed to the throttle body. The second feature is that it has been buried in.

  Furthermore, in addition to the first or second feature, the present invention provides the valve shaft that is offset from the central portion in the intake flow direction of the intake passage to the downstream side, and the recess is formed in the intake passage of the throttle body. A third feature is that an opening is provided in the end face on the downstream side.

  According to the first aspect of the present invention, when a bearing is press-fitted into a bearing holder embedded in a synthetic resin throttle body by insert molding, the bearing exposed in the recess by the press-fitting receiving jig in the recess. By supporting the inner end face of the holder, the press-fit load on the bearing holder of the bearing can be received by the press-fit receiving jig. Therefore, the bearing is securely press-fitted into the bearing holder without bearing the press-fit load on the throttle body. can do.

  In addition, since the concave portion is disposed so as to be located radially outside the intake passage and is isolated from the concave portion, the inner surface of the intake passage may be damaged by the press-fit receiving jig when the press-fit receiving jig is inserted into and removed from the concave portion. There is no worries at all. Therefore, the handling of the press-fitting receiving jig becomes easy, which can contribute to the improvement of productivity and the cost reduction.

  According to the second feature of the present invention, the portion of the inner end surface of the bearing holder that is more than half a circumference is exposed in the recess and is received by the press-fitting receiving jig. Can be smoothly and accurately inserted. In addition, since the remaining portion of the inner end face of the bearing holder is buried in the throttle body, it is possible to ensure a strong coupling between the throttle body and the bearing holder.

  According to the third feature of the present invention, since the recess opens at the downstream end face of the throttle body, which is relatively close to the valve shaft and the throttle valve, the depth of the recess can be made as shallow as possible. As a result, the length of the press-fitting receiving jig inserted into the recess can be shortened as much as possible to increase its bending rigidity, and the bearing holder can be firmly supported against the press-fitting load of the bearing.

1 is a cross-sectional view of an intake control device for an internal combustion engine according to an embodiment of the present invention. The corresponding figure with FIG. 1 which shows the throttle body with a control housing. FIG. FIG. FIG. 5 is a view taken in the direction of arrow 5 in FIG. 3. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a sectional view taken along line 7-7 in FIG. Explanatory drawing of the press fit procedure of a ball bearing to a bearing holder. The perspective view of a press-fit receiving jig.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  In FIG. 1, FIG. 2 and FIG. 6, an intake control device for an internal combustion engine mounted on a vehicle such as a motorcycle or an automobile is composed of a synthetic resin throttle body 1 having an intake passage 2 at the center, and an integrated body. The main body is a control housing 3 made of synthetic resin.

  The throttle body 1 has a pair of bearing bosses 4 and 4 integrally on the left and right side walls thereof, and a mounting flange 5 having a square basic shape is provided at the downstream end of the intake passage 2 of the throttle body 1. It is integrally formed.

  A pair of left and right ball bearings 7 and 7 for rotatably supporting the valve shaft 6 crossing the intake passage 2 are attached to the bearing bosses 4 and 4 via bearing holders 8 and 8, respectively. A throttle valve 9 for opening and closing the intake passage 2 is fixed. One bearing holder 8 is fitted with a ball bearing 7 on the same side and a cap 10 covering one end surface of the valve shaft 6, and the other end of the valve shaft 6 extends into the control housing 3. .

  The valve shaft 6 and the throttle valve 9 are disposed offset from the central portion of the intake passage 2 to the downstream side in the intake flow direction. The mounting flange 5 is provided with a plurality of bolt holes 11, 11... For bolting this to a mounting flange on the intake manifold side of the internal combustion engine (not shown).

  Next, a structure for attaching the bearings 7 and 7 to the bearing bosses 4 and 4 will be described.

  At the time of injection molding of the throttle body 1 with synthetic resin, metal bearing holders 8 and 8 made of metal are embedded in the bearing bosses 4 and 4 by insert molding. At that time, the bearing holders 8 and 8 are arranged so that the respective inner end surfaces 8 a are located on the radially outer side of the intake passage 2. A recess 12 exposing a part of the inner end face 8a is formed so as to open to the downstream end face of the throttle body 1, that is, the end face of the mounting flange 5. In the illustrated example, the recess 12 is formed in an annular shape so as to surround the intake passage 2 on the downstream side of the throttle valve 9, and so that the bottom surface ends beyond the axis of the valve shaft 6 to the upstream side of the intake passage 2. Further, the annular recess 12 is formed such that the inner peripheral surface on the inner side thereof has a cylindrical shape concentric with the inner peripheral surface of the intake passage 2 and the inner peripheral surface on the outer side forms a polygon (FIGS. 2 and 2). 5).

  As shown in FIGS. 6 and 7, a portion of the inner end surface 8 a of the bearing holder 8 that is more than half a circumference is exposed in the recess 12, and the remaining portion is buried in the bearing boss 4. A plurality of annular anchor grooves 13 are formed on the outer peripheral surface of the bearing holder 8 to reinforce the coupling force with the bearing boss 4.

  After the bearing holder 8 is embedded in the bearing boss 4 by insert molding in this way, as shown in FIG. 8, the ball bearing 7 is press-fitted into the bearing holder 8 from the outer end side thereof by the press-fitting jig J2. At that time, the press-fitting receiving jig J1 is inserted into the concave portion 12 in advance and waited.

  As shown in FIG. 9, the press-fitting jig J1 is formed of a polygonal cylinder corresponding to the polygonal inner peripheral surface of the outer side of the recess 12, and a pair of opposed flat walls 15, Are provided with notches 16 and 16 that allow the base of the pair of bearing bosses 4 and 4 to be received, and a support portion 17 that can receive an exposed portion of the inner end surface 8a of the bearing holder 8 to the recess 12.

  Thus, the press-fitting receiving jig J1 inserted into the recess 12 first receives the roots of the bearing bosses 4 and 4 in the notches 16 and 16 and first enters the recess 12 on the inner end surface 8a of the left or right bearing holder 8. In this state, the ball bearing 7 is press-fitted into the one bearing holder 8 from the outer end side. Therefore, the press-fitting load of the ball bearing 7 to the bearing holder 8 by the press-fitting jig J2 is received by the press-fitting receiving jig J1, so that the ball bearing 7 is supported without bearing the press-fitting load on the throttle body 1. The holder 8 can be securely press-fitted.

  In addition, since the press-fitting receiving jig J1 is inserted into the recess 12 that is radially outside the intake passage 2 and is isolated from it, the press-fitting receiving jig J1 is inserted into the recess 12 and waits. There is no concern of damaging the inner surface of the intake passage 2 with the tool J1. Therefore, the press-fitting jig J1 can be easily handled, which can contribute to the improvement of productivity and the cost reduction.

  Further, since the portion of the inner end surface 8a of the bearing holder 8 is more than half a circumference exposed to the recess 12 and received by the press-fitting receiving jig J1, the posture of the bearing holder 8 is stabilized and the ball bearing 7 is press-fitted smoothly and accurately. be able to. In addition, since the remaining portion of the inner end face 8a of the bearing holder 8 is buried in the bearing boss 4, a strong coupling state between the bearing boss 4 and the bearing holder 8 can be ensured.

  On the other hand, since the press-fitting receiving jig J1 is composed of a polygonal cylinder, it has high bending rigidity and can firmly support the bearing holder 8 against the press-fitting load. Further, since the recess 12 is opened at the downstream end face of the throttle body 1 that is relatively close to the valve shaft 6 and the throttle valve 9, the depth can be made as shallow as possible. As a result, the recess 12 is inserted into the recess 12. The length of the press-fitting receiving jig J1 can be shortened as much as possible to further increase the bending rigidity.

  In order to regulate the press-fitting depth of the ball bearing 7 into the bearing holder 8, an inward flange 18 with which the inner end of the ball bearing 7 abuts is formed at the inner end of the bearing holder 8 (FIGS. 1 and 2).

  After the ball bearing 7 is press-fitted into the one bearing holder 8, the ball bearing 7 is press-fitted into the other bearing holder 8 in the same manner.

  When the mounting flange 5 is bolted to a mounting flange on the intake manifold side (not shown), the recess 12 is closed by the mounting flange on the intake manifold side so that dust and the like do not enter.

  1 to 3 again, the control housing 3 is integrally formed with the throttle body 1 with synthetic resin from the one bearing boss 4 to two sides forming a right angle of the mounting flange 5.

  The control housing 3 includes a cylindrical motor housing portion 3a connected to one side of the mounting flange 5 and arranged in parallel with the valve shaft 6, and a valve shaft 6 from one end in the axial direction of the motor housing portion 3a. The gear housing 3b is a flat and substantially rectangular parallelepiped gear housing 3b extending in a direction perpendicular to the bearing boss 4, and the surface of the gear housing 3b opposite to the throttle body 1 is an open surface. Yes. The motor accommodating portion 3a accommodates the electric motor 20, and the gear accommodating portion 3b accommodates a reduction gear device 21 that decelerates the rotation of the electric motor 20 and transmits it to the valve shaft 6. A synthetic resin cover 22 covering the device 21 is joined to the open surface of the control housing 3 by screws 23.

  The reduction gear device 21 includes a primary drive gear 26 fixed to the output shaft 25 of the electric motor 20, a primary driven gear 26 ′ rotatably supported on the intermediate shaft 27 and meshed with the primary drive gear 26, A secondary drive gear 28 integrally formed on one side of the primary driven gear 26 ′, and a sector type secondary driven gear 28 ′ fixed to the valve shaft 6 by a nut 29 and meshing with the secondary drive gear 28. The rotation of the output shaft 25 of the electric motor 20 is decelerated in two steps and transmitted to the valve shaft 6 so that the throttle valve 9 can be opened and closed. Each gear of the reduction gear device 21 is a spur gear, and the valve shaft 6, the output shaft 25, and the intermediate shaft 27 are arranged such that their axis lines are orthogonal to the axis line of the intake passage 2 and are parallel to each other. The intermediate shaft 27 is fixedly supported at one end by a cylindrical support boss 30 formed integrally with the control housing 3 by insert molding, and the other end is supported by being fitted into a support hole 31 provided in the cover 22. . The secondary driven gear 28 ′ is connected to a closing spring 32 made of a torsion coil spring that urges the secondary driven gear 28 ′ in the closing direction of the throttle valve 9.

  A throttle opening sensor 33 that detects the opening of the throttle valve 9 is provided between the valve shaft 6 of the throttle valve 9 and the cover 22. This throttle opening sensor 33 is a known sensor that takes out the opening of the throttle valve 9 as an electrical signal, and is attached to the end of a socket-type nut 29 that fixes the secondary driven gear 28 'to the valve shaft 6. And a receiver 35 attached to the cover 22 so as to face the transmitter 34.

  Each part of the control housing 3 is formed with ribs for reinforcing it as follows. First, in FIG. 3 to FIG. 5, the gear housing 3 b has a flat, substantially rectangular parallelepiped shape having the arrangement direction of the valve shaft 6 and the electric motor 20 as long sides. As shown in FIGS. 4 and 5, a pair of opposing sides of the outer side on the long side of the gear housing 3b and the outer side on the short side near the valve shaft 6 are spaced apart from each other by a certain distance. The long ribs 40, 40 and a plurality of connecting ribs 41, 41,..., 42, 42, which integrally connect the long ribs 40, 40 at least on the long side are formed. At this time, at least three connecting ribs 41 are provided on the output shaft 25, the intermediate shaft 27, and the valve shaft 6 while being orthogonal to the long ribs 40, 40 in a side view when the gear housing 3 b is viewed from the long side. Each is arranged on an axis. The other connecting ribs 42 are disposed so as to cross the long ribs 40, 40.

  As described above, the gear housing portion 3b is effectively strengthened by the pair of long ribs 40, 40 and the plurality of connecting ribs 41, 41,..., 42, 42,. Although it is made of synthetic resin, it is not deformed by the driving reaction force during operation of the electric motor 20, and it is not deformed even if it is vibrated from the internal combustion engine side. The force can be efficiently transmitted to the valve shaft 6 via the reduction gear device 21, the inner peripheral surface of the intake passage 2 can be prevented from being distorted, and the intake air amount controlled by the throttle valve 9 can be stabilized. .

  In particular, mixing the connecting ribs with those 41 orthogonal to the long ribs 40 and 40 and those oblique with each other constitutes a truss structure between the pair of long ribs 40 and 40. Since the rigidity enhancement of the gear housing portion is further promoted, it is extremely effective for preventing deformation of the gear housing portion 3b.

  Further, at least three connecting ribs 41 orthogonal to the long ribs 40, 40 are provided on the axis of the output shaft 25, the intermediate shaft 27 and the valve shaft 6 in a side view when the gear housing portion 3 b is viewed from the long side. As a result, the gear housing portion 3b can be effectively reinforced around the output shaft 25, the intermediate shaft 27, and the valve shaft 6, thereby preventing deformation thereof.

  Further, the mutual spacing between the connecting ribs 41, 41,..., 42, 42,. In this way, the number of connecting ribs 41, 41..., 42, 42... Is increased on the motor housing 3a side and decreased on the throttle body 1 side, so that the connecting ribs 41, 41. The gear housing portion 3b on the motor housing portion 3a side can be effectively reinforced while minimizing the number used. Therefore, even if the motor housing portion 3a receives a large driving reaction force of the electric motor 20 or has a large vibration energy when excited from the internal combustion engine side, it becomes the root of the motor housing portion 3a. The deformation of the gear housing portion 3b can be prevented.

  Further, on the bottom surface of the gear housing portion 3b opposite to the open surface, there are a plurality of ribs 43 that connect the support boss 30 and the opposing inner surfaces on the long sides of the gear housing portion 3b. 43 is formed. In the illustrated example, a pair of ribs 43 and 43 are formed so as to connect the opposing inner side surfaces on the long side while crossing in an X shape at the support boss 30. The ribs 43, 43 cooperate with the outer long ribs 40, 40 and the connecting ribs 41, 41 ...; 42, 42 ... to reinforce the gear housing portion 3b more effectively. Deformation can be prevented more reliably, and at the same time, the support boss 30 can be reinforced to increase the support rigidity of the intermediate shaft 27 and to stabilize the support of the primary driven gear 26 ′ and the secondary drive gear 28.

  Further, a plurality of ribs 44, 44... Orthogonal to the grid are also formed on the outer peripheral surface of the motor housing 3a. Thereby, since the motor accommodating part 3a is reinforced, the support rigidity with respect to the electric motor 20 of the motor accommodating part 3a can be improved.

  A cylindrical gate portion 45 having a diameter larger than the wall thickness is formed at a plurality of locations of the various ribs 40 to 44. These gate portions 45 are portions formed by a mold gate when the throttle body 1 and the control housing 3 are injection molded. Therefore, at the time of injection molding, the molten resin corresponds to the various ribs 40 to 44 from the gate. Since the narrow cavity is filled into the corresponding wide cavity of the control housing 3 and the throttle body 1, it is possible to obtain a high-quality synthetic resin throttle body 1 and control housing 3 that are surely filled and have no nest. .

  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 ball bearing 7, other types of bearings such as a plain bearing can be used.

1 ... Throttle body 2 ... Intake passage 6 ... Valve shaft 7 ... Bearing (ball bearing)
8 .... Bearing holder 8a ... Inner end face 9 ... Throttle valve J1 ... Press fitting jig

Claims (3)

A synthetic resin throttle body (1) having an intake passage (2) and a pair of cylindrical inserts formed on the throttle body (1) so as to be coaxially arranged with the intake passage (2) in between Bearing holder (8), a pair of bearings (7) press-fitted and held in these bearing holders (8), a valve shaft (6) rotatably supported by these bearings (7), and this valve shaft (6 And an intake control device for an internal combustion engine comprising a throttle valve (9) that opens and closes the intake passage (2) by its rotation,
The bearing holder (8) is disposed so that its inner end face (8a) is positioned radially outside the intake passage (2), and at least a part of the inner end face (8a) is exposed (12). ) Is formed in the throttle body (1) so as to be located radially outside the intake passage (2), and when the bearing (7) is press-fitted into the bearing holder (8), the bearing holder An intake control device for an internal combustion engine, characterized in that a press-fit receiving jig (J1) for supporting the inner end face (8a) of (8) can be inserted into the recess (12). The intake control device for an internal combustion engine according to claim 1,
Of the inner end surface (8a) of the bearing holder (8), a portion of more than half a circumference is exposed to the recess (12) so as to be supported by the press-fitting receiving jig (J1), and the remaining portion is exposed to the throttle body ( An intake control device for an internal combustion engine, characterized in that it is buried in 1). The intake control device for an internal combustion engine according to claim 1 or 2,
The valve shaft (6) is disposed offset from the central portion in the intake air flow direction of the intake passage (2), and the concave portion (12) is disposed on the intake passage (2) of the throttle body (1). An intake control device for an internal combustion engine, wherein the intake air control device is opened at an end face on the downstream side.

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