JP2010223127A - Actuator for pipe length switching valve of intake manifold and intake manifold having actuator for pipe length switching valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator capable of reducing the number of part items, or capable of reducing assembling manhours, while protecting the actuator itself. <P>SOLUTION: An actuator case is arranged on an opposite side surface of a butting surface, and has a breathing hole for communicating the actuator case inside with outside air. In this actuator 10 for a pipe length switching valve of an intake manifold 12, the breathing hole is arranged outside an annular seal surface in the butting surface so as to communicate up to the butting surface from the actuator case inside, and when the butting surface is butted against an end surface, the end surface forms a breathing clearance between a part and the end surface for arranging the breathing hole among the butting surface, while forming a cap means to the breathing hole. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an intake manifold having a pipe length switching valve actuator and an intake manifold having a pipe length switching valve actuator, and more specifically, an intake air that can reduce the number of parts or assembly man-hours while protecting the actuator itself. The present invention relates to an actuator for a pipe length switching valve of a manifold and an intake manifold having a pipe length switching valve actuator.

Conventionally, an intake manifold in which the pipe length of the intake passage is made variable by opening and closing the valve has been adopted, and an actuator for switching the pipe length of the intake manifold has been used for that purpose.
An actuator for a pipe length switching valve of an intake manifold is disclosed in Patent Document 1, for example.
As shown in FIGS. 8 to 10, the intake manifold pipe length switching valve actuator 200 has a plurality of intake passages 214 arranged in parallel from an opening provided on one end face in the parallel direction of the intake manifold. A switching valve mechanism 216 that is inserted into a support hole that traverses the intermediate portion of the auxiliary intake passage of the intake passage and opens and closes so that the length of each intake pipe can be switched, and a valve cover 218 that supports one end of the switching valve mechanism 216. The valve cover 218 is provided with an abutting surface fixed to the end surface, and an annular seal portion surrounding one end of the switching valve mechanism 216 is provided on the abutting surface, and a drive motor 223 for driving the switching valve mechanism 216. And an actuator case 222 with a built-in drive motor 223. Provided on a surface opposite to the Align surface, actuator case 222 has a breathing hole 224 communicating the interior actuator case and the outside air.

With such a configuration, it is possible to switch the pipe length of each intake passage 214 by driving the switching valve mechanism 216 by the drive motor 223 of the actuator and connecting or blocking the auxiliary intake passage through the valve opening / closing operation. .
At this time, since the actuator case 222 is provided with a breathing hole 224 for ventilating the inside and outside of the actuator case 222, the drive motor 223 in the actuator case 222 generates heat by repeating such opening and closing operations, and the actuator case 222 is heated. The temperature inside the engine case rises, or conversely, the temperature inside the engine room where the intake manifold is installed rises, creating a pressure difference between the inside and outside of the actuator case 222, whereby the pressure inside the actuator case 222 is increased. Rises and sometimes causes damage to the case, or conversely, the pressure inside the case becomes negative compared to the outside of the case, and moisture enters the case from outside the case, thereby causing failure of the actuator. It is possible to prevent such a situation A.

However, there are the following technical problems with the conventional actuator for switching the pipe length of the intake manifold.
That is, as shown in FIG. 10, the breathing hole 224 is provided with a normal filter 226 that closes the breathing hole 224 and a cap 228 that is provided at the end of the breathing hole 224 and protects the filter 226. In order to prevent the breathing hole 224 from breathing through the filter 226 by completely closing the breathing hole 224, the cap 228 is provided with a protrusion 230 from the viewpoint of ensuring ventilation.
Such a cap 228 increases the number of parts of the actuator or the number of assembly steps. However, if the cap 228 is omitted, the protection of the filter 226 is insufficient and the filter may be damaged.
JP 2001-248449 A

In view of the above technical problems, an object of the present invention is to provide an intake manifold pipe length switching valve actuator and a pipe length switching valve actuator that can reduce the number of parts or the number of assembly steps while protecting the actuator itself. It is to provide an intake manifold.

In order to achieve the above object, an actuator for a pipe length switching valve of an intake manifold according to the present invention includes:
Inserted into a support hole that crosses the middle of the sub-intake passage of each intake passage through an opening provided on one end face in the parallel direction of an intake manifold having a plurality of intake passages arranged in parallel. A switching valve mechanism that opens and closes in a switchable manner,
A valve cover for supporting one end of the switching valve mechanism, comprising a butting surface fixed to the end surface, wherein the butting surface is provided with an annular seal portion surrounding one end of the switching valve mechanism; ,
A drive motor for driving the switching valve mechanism; and an actuator case containing the drive motor;
The actuator case is provided on a surface opposite to the abutting surface, and has a breathing hole that communicates the inside of the actuator case with the outside air.
The breathing hole is provided outside the annular seal portion at the butting surface so as to penetrate the valve cover from the opposite surface to the butting surface.
When the abutting surface is abutted against the end surface, the end surface forms a cap means for the breathing hole, and the breathing surface is provided between a portion of the abutting surface where the breathing hole is provided and the end surface. The gap is formed.

According to the pipe manifold switching valve actuator of the intake manifold having the above configuration, the length of the intake pipe can be changed by connecting or blocking the auxiliary intake passage through the opening / closing operation of the valve of the switching valve mechanism by the actuator. Is possible.
Since the actuator case is provided with a breathing hole for venting the inside and outside of the actuator case, the drive motor in the actuator generates heat due to repetition of such opening and closing operations, and the temperature in the actuator case increases or vice versa. In addition, when the temperature inside the engine room where the intake manifold is installed rises, a pressure difference is created inside and outside the actuator case, which increases the pressure inside the actuator case, possibly causing damage to the case. Or, conversely, the pressure inside the case becomes negative compared to the outside of the case, and moisture etc. can enter the case from outside the case, thereby preventing the actuator from being damaged. is there.

In this case, since the breathing hole is provided outside the annular seal portion of the valve cover so as to penetrate the valve cover from the opposite surface of the valve cover to the butting surface, the butting surface of the valve cover is in contact with the end surface. By being abutted, the end surface itself functions as a cap means for the breathing hole, and achieves full protection of the filter provided to close the breathing hole without providing a separate cap part as in the prior art. It is possible.
On the other hand, the outer surface of the annular seal portion of the butting surface of the valve cover has a larger surface roughness than the annular sealing portion that requires a sealing function, so the butting surface of the valve cover is butted against the end surface. Even so, a gap is inevitably formed between the outer portion of the annular seal portion and the end face, and therefore, using this gap, the inside of the actuator case passes through the breathing hole with the outside air, It is possible to breathe.
From the above, it is possible to reduce the number of parts or the number of assembling steps by securing the ventilation inside and outside the actuator case with the breathing hole and omitting the cap part for the breathing hole while protecting the actuator itself.

The valve cover may have a recess on a surface opposite to the abutting surface, and the actuator case may be integrally formed with the recess.

Still further, the valve cover is integrally formed of resin, whereby a difference in processing accuracy on molding between the portion where the breathing hole is provided in the butting surface and the annular seal portion is caused by the breathing. It is preferable to form a clearance for use. Alternatively, the valve cover may be integrally formed of a resin, and a portion of the abutting surface where the breathing hole is provided may be one step lower than the annular seal portion.

In addition, the switching valve has a rotating shaft inserted into the support hole along the axial direction,
The valve cover has a through-hole through which one end of the rotating shaft comes out at a central portion thereof, and a first space extending from the through-hole in the thickness direction of the valve cover,
The actuator case preferably has a second space that communicates laterally with the first space and accommodates the drive motor.

According to the pipe manifold switching valve actuator of the intake manifold according to the present invention, the breathing hole is provided outside the annular seal portion of the valve cover so as to penetrate the valve cover from the opposite surface of the valve cover to the butting surface. Therefore, when the butting surface of the valve cover is abutted against the end surface, the end surface itself functions as a cap means for the breathing hole, and closes the breathing hole without preparing a separate cap part as in the prior art. It is possible to achieve sufficient protection of the filter provided as described above, and the portion outside the annular seal portion of the butt surface of the valve cover is the surface compared to the annular seal portion requiring a sealing function. Since the roughness is large, even if the butting surface of the valve cover is butted against the end surface, the annular seal part Since a gap is inevitably formed between the outer portion and the end face, the inside of the actuator case can breathe through the breathing hole with the outside air using this gap. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1 to FIG. 3, the actuator 10 for the intake manifold pipe length switching valve is inserted into the intake manifold 12 to perform opening / closing operation so that the length of each intake passage 14 of the intake manifold 12 can be switched. The valve mechanism 16, an actuator valve cover 20 that supports one end of the switching valve mechanism 16 and closes the opening 18 (see FIG. 4) of the intake manifold 12 into which the switching valve mechanism 16 is inserted, and the switching valve mechanism 16. The actuator valve cover 20 has a breathing hole 24 (see FIG. 6) that communicates the inside of the actuator valve cover 20 and the outside air. Yes.

The intake manifold 12 corresponds to a four-cylinder engine, and has a surge tank 26 that forms an intake manifold and a main intake passage 28 that communicates with the intake manifold, and one end of the intake manifold 12 is connected to the surge tank 26. It has four mutually independent branch pipes 30 connected in common, and an engine mounting flange 32 connected to the other end of each branch pipe 30, and the four branch pipes 30 are arranged in parallel in the horizontal direction. ing.
The intake manifold 12 is made of, for example, a synthetic resin, and is configured by welding a plurality of, for example, three joining members to each other.
An air inlet 34 is provided at one end of the surge tank 26 along the parallel direction of the branch pipes 30, and an air cleaner (not shown) is connected to the air inlet 34 via a throttle body (not shown). An amount of air corresponding to the throttle opening in the throttle body is introduced into the intake air collecting chamber.
As shown in FIG. 2, each branch pipe 30 having one end connected to the lower portion of the surge tank 26 is formed to be curved in a substantially C shape, and is attached to the other end of each branch pipe 30. The working flange 32 is disposed on the downstream side of the surge tank 26.
The intake manifold 12 is provided with a sub-intake passage 36 having one end opened to the intake manifold and the other end opened in the middle of the main intake passage 28. A passage from the intake manifold to the engine by the sub-intake passage 36 is provided. Can be bypassed.

As shown in FIG. 3, the communication or blocking of each auxiliary intake passage 36 is switched by a switching valve mechanism 16 having a butterfly valve that is rotatably supported on the intake manifold 12. The switching valve mechanism 16 corresponds to the cross section of the rotary shaft 42 and each auxiliary intake passage 36, and the plate portion 46 provided with four openings 44 aligned in the axial direction of the rotary shaft 42 and the four openings 44. Corresponding to the position, there are four valve bodies 48 fixed to the rotary shaft 42 at a predetermined interval in the axial direction of the rotary shaft 42.
Each valve body 48 has a plate-like shape, and corresponds to each sub-intake passage 36, and as shown in FIG. As shown in b), it can be rotated around the axis between the position where the auxiliary intake passage 36 is blocked.
As shown in FIG. 4, the end face 114 of the intake manifold 12 is provided with a substantially rectangular cross-section space that crosses the middle portion of each auxiliary intake passage 36, and the opening 18 provided at one end in the parallel direction of the four branch pipes 30. Thus, the switching valve mechanism 16 is inserted into the surge tank 26 along the longitudinal direction of the rotary shaft 42.

In the plate portion 46, the rotary shaft 42 passes through each of the four openings 44 in the axial direction, and the valve body 48 is fixed to the rotary shaft 42 in each opening 44, and the axial direction of the rotary shaft 42 is the center. Each valve body 48 is rotated by the rotation, so that the corresponding opening 44 is opened and closed. A circular opening 54 through which the rotary shaft 42 passes is provided at one end of the plate portion 46, and an O-ring 56 is attached to the peripheral edge of the circular opening 54, and this circular opening 54 will be described later on the actuator valve cover 20. The first hollow cylindrical portion 88 is fitted so as to be sealed (see FIG. 5).
As shown in FIG. 5, the rotary shaft 42 is supported by a bearing 58 fixedly supported by the wall surface of the support hole 40 so as to be rotatable about the axial direction. A first cylindrical collar 60, a stopper lever 62, a second cylindrical collar 64, a cushion rubber 66, and a worm wheel gear 68 are fitted on the rotary shaft 42 in this order from the bearing 58 toward one end of the rotary shaft 42. ing.
More specifically, the first cylindrical collar 60 is interposed between the bearing 58 and the stopper lever 62, and transmits the axial force from the flange nut 59 fastened from one end of the rotating shaft 42 to the bearing 58 from the stopper lever 62. Like to do.

The stopper lever 62 is fixed to the rotation shaft 42 in the rotation direction around the axis, and rotates integrally with the rotation shaft 42. The stopper lever 62 is provided with a projecting portion 70 that projects in the radial direction from the rotating shaft 42, and the rotating shaft 42 is inserted when the projecting portion 70 rotates about the axial direction by the rotation of the rotating shaft 42. A rotation restricting member (not shown) provided on the inner wall of the support hole 40 is abutted to restrict the rotation range of the rotation shaft 42. More specifically, the rotation shaft 42 is configured to be rotatable between a rotation angle position corresponding to a closed position of a valve provided on the rotation shaft 42 and a rotation angle position corresponding to an opening position. As described above, the rotation shaft 42 is restricted in rotation by the projecting portion 70 coming into contact with the rotation restricting member provided on the inner wall of the support hole 40, so that the valve is positioned at the closed position and the open position. When the overhanging portion 70 collides with the rotation restricting member provided on the inner wall of the support hole 40, an impact load is generated, and this impact load is transmitted to the drive motor 22 through the rotation shaft 42. Such an impact load is absorbed by the cushion rubber 66 interposed between the lever 62 and the drive motor 22, and the impact load transmitted to the drive motor 22 is alleviated, and thus the drive motor 22 is fully protected. I am doing so.

The second cylindrical collar 64 is interposed between the stopper lever 62 and the flange nut 59, and transmits the axial force generated by fastening of the flange nut 59 to the stopper lever 62 via the second cylindrical collar 64. . The second cylindrical collar 64 has an annular projecting flange 72 at one end toward the flange nut 59, and the annular outer surface 74 of the annular projecting flange 72 receives the fastening force of the flange nut 59, and the second tubular collar 64. A cushion rubber 66 and a worm wheel gear 68 are slidably fitted in the axial direction in this order toward the annular projecting flange 72 on the shaft portion 64, and one end surface of the worm wheel gear 68 is annular projecting flange 72. It arrange | positions so that it may contact | abut to the annular inner surface 78 of this.

The shaft length of the shaft portion of the second cylindrical collar 64 is set to be shorter than the total length of the shaft length of the cushion rubber 66 and the flange thickness of the worm wheel gear 68, whereby the second cylindrical shape is secured by fastening the flange nut 59. The collar 64 and the cushion rubber 66 or the worm wheel gear 68 slide in the axial direction, and the axial length of the shaft portion of the second cylindrical collar 64, the axial length of the cushion rubber 66, and the flange thickness of the worm wheel gear 68. The cushion rubber 66 is slightly squeezed in the axial direction according to the difference from the total length, and the repulsive force acts in the direction opposite to the axial force due to the fastening of the flange nut 59, thereby causing the worm wheel gear 68 to be annularly extended flange 72. The worm wheel gear 68 is fixed in the axial direction by pressing against the annular inner surface 78. In this regard, the axial length of the shaft portion of the second cylindrical collar 64 is such that when the worm wheel gear 68 is fixed in the axial direction by fastening the flange nut 59, the cushion rubber 66 is properly crushed in the axial direction. It is necessary to set the range.

The cushion rubber 66 is made of a hollow-cylindrical synthetic rubber. As described above, when an impact load centered on the axial direction of the rotating shaft 42 is generated by the overhanging portion 70, the cushion rubber 66 is caused by such an impact load. Causes torsional elastic deformation about the axial direction, absorbs the impact load by this torsional elastic deformation, relieves the impact load transmitted to the drive motor 22, and thereby achieves sufficient protection of the drive motor 22. As long as it is, the thickness, material, etc. may be appropriately selected. One end surface of the cushion rubber 66 is in contact with the end surface of the stopper lever 62, and a plurality of recessed portions A 80 are provided in the circumferential direction on the one end surface, and each recessed portion A 80 is provided on the end surface of the stopper lever 62. The cushion rubber 66 and the stopper lever 62 are integrally rotated about the axial direction by fitting into the protruding portion A82. On the other hand, the other end surface of the cushion rubber 66 is in contact with the end surface of the worm wheel gear 68. Like the one end surface, the other end surface is provided with a plurality of indentations B81 in the circumferential direction. The cushion rubber 66 and the worm wheel gear 68 are integrally rotated about the axial direction by fitting B81 into the protrusion B83 provided on the end face of the worm wheel gear 68. As described above, the stopper lever 62, the cushion rubber 66, and the worm wheel gear 68 can be integrally rotated around the axial direction, and the rotational driving force of the drive motor 22 described later is applied to the worm wheel gear 68, the cushion rubber 66, and Since it is transmitted to the stopper lever 62 and the stopper lever 62 rotates integrally with the rotating shaft 42, the rotating shaft 42 is rotated by the drive motor 22.

As shown in FIG. 3, an actuator valve cover 20 in which an actuator case incorporating a drive motor 22 and a valve cover are integrated is provided at one end of the switching valve mechanism 16.
The actuator valve cover 20 is made of an integrally molded resin, for example.
As a result, the actuator case and valve cover are separate, and the number of parts can be reduced or the cost can be reduced by reducing the number of assembly steps compared to the conventional case where the actuator case is fixed to the valve cover with a nut or the like. In addition, the vibration resistance can be improved by integrating the actuator case and the valve cover. In particular, it is possible to shorten the axial length of the switching valve actuator 10 by integrating the actuator case with the recess of the surface 85 opposite to the butting surface 84 of the valve cover 20.

As shown in FIG. 3, the actuator valve cover 20 has a plate shape, and as shown in FIG. 6, one surface thereof constitutes a butting surface 84 with the end surface of the intake manifold 12. The abutting surface 84 has a circular opening 86 at the center thereof, and a first hollow cylindrical portion 88 extending from the circular opening 86 in the thickness direction of the actuator valve cover 20 is provided. In one space 110, a stopper lever 62, a cushion rubber 66, a worm wheel gear 68 and a flange nut 59 are accommodated. A circular opening 90 is provided on the side wall of the first hollow cylindrical portion 88, and a second hollow cylindrical portion 92 extending from the circular opening 90 in the lateral direction of the actuator valve cover 20 is provided, as shown in FIG. The opposite end surface of the second hollow cylindrical portion 92 is open. The drive motor 22 described later is accommodated in the second space 112 inside the second hollow cylindrical portion 92.
As shown in FIG. 6, the butting surface 84 is provided with an annular seal surface 94 so as to surround the circular opening 86, and when the annular sealing surface 94 is butted against the end surface 114 of the intake manifold 12, the butting surface 84 is provided. Is sealed. A mounting hole 96 is provided around the actuator valve cover 20 so as to correspond to the mounting hole 113 provided in the end surface 114 of the intake manifold 12 so that the actuator valve cover 20 is fixed to the end surface 114 of the intake manifold 12. ing.

With the above configuration, the switching valve mechanism 16 is inserted into the surge tank 26 along the axial direction of the rotary shaft 42, the butting surface 84 of the actuator valve cover 20 is butted against the end surface 114 of the intake manifold 12, and the intake hole 96 By fixing to the manifold 12, one end of the rotary shaft 42 is accommodated in the first space 110 of the first hollow cylindrical portion 88 while being hermetically held by the annular seal surface 94, and the rotary shaft 42 is in the worm wheel gear 68 and the worm 98. And the drive motor 22 disposed in the second space 112 of the second hollow cylindrical portion 92 through which the rotary shaft 42 is rotated.

As shown in FIG. 3, the drive motor 22 is conventionally known. A worm 98 is provided at the tip of the rotary shaft 23, and the drive motor 22 rotates by engaging with the worm wheel gear 68 of the rotary shaft 42. The driving force is transmitted to the rotary shaft 42 via the worm 98 and the worm wheel gear 68. The drive motor 22 is housed in the second space 112 of the second hollow cylindrical portion 92, and is driven with respect to the axial direction of the rotary shaft 42 in which one end is housed in the first space 110 of the first hollow cylindrical portion 88. The rotating shaft 23 of the motor 22 is arranged in a direction that is substantially orthogonal. A packing 100 is provided at the periphery of the opening of the second hollow cylindrical portion 92 so that the opening can be closed by the lid portion 102. A rotation angle detection sensor 104 is attached to the lid 102, and when the opening is closed by the lid 102, the rotation angle detection sensor 104 is attached to the stopper lever 62 located in the first space 110 of the first hollow cylindrical portion 88. It extends to a position facing the provided magnet 105. The rotation angle detection sensor 104 is a known sensor that incorporates a Hall element, detects a change in the magnetic flux of the magnet 105 due to the rotation of the rotary shaft 42 about the axial direction, and generates an electromotive force due to the magnetic flux change. Is used to detect the rotation angle of the valve fixed to the rotary shaft 42.

As shown in FIG. 6, the actuator valve cover 20 has a breathing hole 24 that allows the inside of the actuator valve cover 20 to communicate with the outside air. The diameter of the breathing hole 24 may be appropriately determined according to the filter performance from the viewpoint of the air permeability between the inside of the actuator valve cover 20 and the outside air.
As shown in FIG. 7, the breathing hole 24 is provided at a position inside the actuator valve cover 20 from the abutting surface 84 so that the filter 106 closes the breathing hole 24, and the inside of the actuator valve cover 20. Foreign matter is not mixed in.
The breathing hole 24 is provided outside the annular seal surface 94 at the butting surface 84 so as to penetrate the actuator valve cover 20 from the opposite surface 85 to the butting surface 84. Thereby, when the abutting surface 84 is abutted against the end surface 114 of the intake manifold 12, the end surface functions as a cap for the breathing hole 24, and between the portion of the abutting surface 84 where the breathing hole 24 is provided and the end surface. A breathing gap 108 is formed.

More specifically, the actuator valve cover 20 is made of an integrally molded resin, and when the actuator valve cover 20 is molded, an outer portion of the annular seal surface 94 provided with the breathing hole 24 in the butting surface 84, and the annular seal surface 94 is provided with a difference in processing accuracy in molding, and the annular seal surface 94 that requires sealing performance with the end surface has a high surface roughness, while the annular sealing surface 94 does not require sealing performance with the one end surface. The outer portion of the sealing surface 94 has a low surface roughness. As a result, when the annular sealing surface 94 is sealingly abutted against the end surface, a gap is inevitably formed between the end surface and the outer portion of the annular sealing surface 94, and this gap is the outer portion of the annular sealing surface 94. Thus, the breathing gap 108 of the breathing hole 24 provided at the position is formed.
As a result, it is possible to eliminate the need for a cap that closes the breathing hole 24 while securing the breathing gap 108 so as not to completely block the breathing hole 24 as in the prior art.
As a modification, a step is provided between the outer portion of the annular seal surface 94 where the breathing hole 24 is provided and the annular seal surface 94, and the outer portion of the annular seal surface 94 is one step lower than the annular seal surface 94. You may comprise.
Furthermore, as a modification, the end face may be configured to block only a part of the breathing hole 24.

The operation of the intake manifold pipe length switching valve actuator 10 having the above configuration will be described in detail below with reference to the drawings.
When the switching valve mechanism 16 is switched from the closed state to the open state in order to bypass the auxiliary intake passage 36 in order to shorten the intake passage 14 of the intake manifold 12, the worm 98 and the worm wheel are driven by driving the drive motor 22. The rotation shaft 42 rotates through meshing with the gear 68, and the corresponding valve fixed to the rotation shaft 42 opens in each auxiliary intake passage 36, whereby the intake passage 14 can be shortened. is there.
On the contrary, when the switching valve mechanism 16 is switched from the open state to the closed state in order to lengthen the intake passage 14 of the intake manifold 12, it may be achieved by performing the operation opposite to that described above.

When the switching valve mechanism 16 is repeatedly opened and closed, the actuator drive motor 22 generates heat, and the temperature in the actuator valve cover 20 increases or the temperature in the engine room increases. There may be a pressure difference between the inside and outside of the actuator valve cover 20. In such a case, since air permeability is ensured between the inside of the actuator valve cover 20 and the outside air through the breathing hole 24, the actuator valve cover accompanying such a pressure difference can be obtained by breathing according to the pressure difference. It is possible to prevent 20 damages or failures.

In this case, the breathing hole 24 is provided outside the annular seal surface 94 of the actuator valve cover 20 so as to penetrate the actuator valve cover 20 from the opposite surface 85 of the actuator valve cover 20 to the butting surface 84. From the above, the butting surface 84 of the actuator valve cover 20 is butted against the end surface, so that the end surface itself functions as a cap means for the breathing hole 24, and the breathing hole can be provided without preparing a separate cap part as in the prior art. It is possible to achieve full protection of the filter 106 provided to close 24.

On the other hand, the portion of the butting surface 84 of the actuator valve cover 20 that is outside the annular sealing surface 94 has a larger surface roughness than the annular sealing surface 94 that requires a sealing function. Even if the surface 84 is abutted against the end face, a breathing gap 108 is inevitably formed between the outer portion of the annular seal surface 94 and the end face. The inside of the actuator valve cover 20 can breathe through the breathing hole 24 with the outside air.
From the above, by securing ventilation between the inside and outside of the actuator valve cover 20 by the breathing hole 24, it is possible to reduce the number of parts or the number of assembly steps by omitting the cap parts for the breathing hole 24 while protecting the actuator itself. It becomes.

While the embodiments of the present invention have been described in detail above, various modifications and variations can be made by those skilled in the art without departing from the present invention. For example, in the present embodiment, the switching valve actuator has been described as corresponding to a four-cylinder engine. However, the present invention is not limited to this. For example, the switching valve actuator may be compatible with an engine having a smaller number of cylinders. Good. Further, in the present embodiment, the butterfly type valve switching mechanism has been described. However, the present invention is not limited thereto, and for example, a rotary valve switching mechanism may be used. Further, in the present embodiment, an actuator valve cover in which the valve cover and the actuator case are integrated is adopted, but the present invention is not limited to this, and the valve cover and the actuator case may be separate. It doesn't matter. Furthermore, in the present embodiment, the single-shaft type switching valve actuator that directly transmits the rotational driving force of the driving motor to a single rotating shaft has been described. However, the actuator case is not limited thereto. As long as the rotary shaft is rotationally driven by the drive motor accommodated therein, a multi-axis type may be used.

It is a schematic front view of the intake manifold provided with the pipe length switching valve actuator of the intake manifold according to the embodiment of the present invention. It is the schematic which shows the effect | action of the pipe length switching valve actuator of the intake manifold which concerns on embodiment of this invention. It is a disassembled perspective view of the pipe length switching valve actuator of the intake manifold according to the embodiment of the present invention. FIG. 4 is an end view of one side of the intake manifold in the pipe length switching valve actuator of the intake manifold according to the embodiment of the present invention. It is a fragmentary sectional view which shows the attachment state with the actuator valve case of the actuator for pipe length switching valves of the intake manifold which concerns on embodiment of this invention. It is sectional drawing of the valve cover seen from the direction in alignment with the AA of FIG. It is sectional drawing of the through hole seen from the direction which follows the BB line of FIG. It is a schematic perspective view of the intake manifold provided with the actuator for pipe length switching valves of the conventional intake manifold. It is a fragmentary perspective view which shows the surroundings of the drive motor provided in the actuator for pipe length switching valves of the conventional intake manifold. It is the schematic of the breathing hole of the actuator for pipe length switching valves of the conventional intake manifold.

10 Intake manifold pipe length switching valve actuator 12 Intake manifold 14 Intake passage 16 Switching valve mechanism 18 Opening 20 Actuator valve cover 22 Drive motor 24 Breathing hole 26 Surge tank 28 Main intake passage 30 Branch pipe 32 Engine mounting flange 34 Air inlet 36 Sub-intake passage 40 Support hole 42 Rotating shaft 44 Opening 46 Plate part 48 Valve body 54 Circular opening 56 O-ring 58 Bearing 59 Flange nut 60 First cylindrical collar 62 Stopper lever 64 Second cylindrical collar 66 Cushion rubber 68 Warm Wheel gear 70 Overhang portion 72 Annular overhang flange 74 Annular outer surface 78 Annular inner surface 80 Recessed portion A
81 Indentation B
82 Protrusion A
83 Projection B
84 Abutting surface 86 Circular opening 88 First hollow cylindrical portion 90 Circular opening 92 Second hollow cylindrical portion 94 Annular seal surface 96 Mounting hole 98 Worm 100 Packing 102 Lid portion 104 Rotation angle detection sensor 106 Filter 108 Respiration gap 110 First space 112 Second space 113 Mounting hole 114 End face

Claims (6)

Inserted into a support hole that crosses the middle of the sub-intake passage of each intake passage from an opening provided on one end face in the parallel direction of an intake manifold having a plurality of intake passages arranged in parallel, and the length of each intake pipe A switching valve mechanism that opens and closes in a switchable manner,
A valve cover for supporting one end of the switching valve mechanism, comprising a butting surface fixed to the end surface, wherein the butting surface is provided with an annular seal portion surrounding one end of the switching valve mechanism; ,
A drive motor for driving the switching valve mechanism; and an actuator case containing the drive motor;
The actuator case is provided on a surface opposite to the abutting surface, and has a breathing hole that communicates the inside of the actuator case with the outside air.
The breathing hole is provided outside the annular seal portion at the abutting surface so as to communicate from the inside of the actuator case to the abutting surface,
When the abutting surface is abutted against the end surface, the end surface forms a cap means for the breathing hole, and the breathing surface is provided between a portion of the abutting surface where the breathing hole is provided and the end surface. An actuator for a pipe length switching valve of an intake manifold, characterized in that a gap is formed.     The actuator for a pipe length switching valve of an intake manifold according to claim 1, wherein the valve cover has a recess on a surface opposite to the abutting surface, and the actuator case is formed integrally with the recess. 3. The valve cover according to claim 2, wherein a difference in processing accuracy in forming between the portion where the breathing hole is provided in the butting surface and the annular seal portion forms the breathing gap. Actuator for pipe length switching valve of intake manifold.     4. The intake manifold according to claim 1, wherein the valve cover has a surface that is one step lower than the annular seal portion on the butting surface, and the breathing hole is provided on the surface. 5. Tube length switching valve actuator. The switching valve has a rotating shaft inserted into the support hole along the axial direction,
The valve cover has a through-hole through which one end of the rotating shaft comes out at a central portion thereof, and a first space extending from the through-hole in the thickness direction of the valve cover,
The actuator for a pipe length switching valve of an intake manifold according to claim 2, wherein the actuator case has a second space that communicates laterally with the first space and accommodates the drive motor.   An intake manifold having the pipe length switching valve actuator of the intake manifold according to any one of claims 1 to 4.

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