JP2005290994A - Throttle control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize high accuracy of a clearance size between an inner diameter surface of a bore of a bore inner tube 5 of a double-tubed throttle body 4 and a throttle valve 1, and obtain predetermined valve-opening flow rate characteristics that the intake air volume continuously increases as the rotation angle of the throttle valve 1 increases. <P>SOLUTION: The throttle valve 1 is housed in the inner tube 5 of the bore so that the end surfaces 11, 12 on the outer diameter side of the throttle valve 1 are not projected either from the annular end surface 13 or the annular end surface 14 of the inner tube 5 of the bore. Thus, discontiguous increase or decrease in the size of an opening is prevented in the process of rotary action of the throttle valve 1. Furthermore, an annular plate-shaped connection 32 connecting the outer peripheral part of the inner tube 5 of the bore and the inner peripheral part of an outer tube 6 of the bore is attached so that it avoids the range where the end surfaces 11, 12 on the outer diameter side of the throttle valve 1 come into contact with the inner diameter surface of the bore of the bore inner tube 5. Thus, the influence of the inner tube 5 of the bore on the accuracy of the inner diameter size of the bore is eliminated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a throttle control device for an internal combustion engine mounted on a vehicle such as an automobile, and more particularly, a throttle that is rotatably supported by a throttle body by driving a drive motor in accordance with an accelerator operation amount of a vehicle occupant. The present invention relates to a throttle control device for an internal combustion engine that controls the valve angle (valve opening) of the valve.

[Conventional technology]
Conventionally, in a throttle control device for an internal combustion engine in which a drive motor is driven in accordance with the amount of depression of an accelerator pedal by a vehicle occupant to control a valve angle (valve opening) of a throttle valve by a predetermined amount, The gap between the bore inner surface of the throttle valve and the outer periphery of the throttle valve has a significant effect on the airtight performance when the throttle valve is fully closed. Improvement of the accuracy of the gap dimension between them is an issue. Further, since the throttle control device for an internal combustion engine as described above is used even in a cold environment such as winter, the intake air is sucked into each cylinder of the engine via the engine intake pipe including the throttle body. When the water contained in the water adheres to the surface of the throttle valve and is cooled and freezes across the throttle bore bore surface and the outer periphery of the throttle valve, the throttle valve contacts the bore bore surface of the throttle body. There is a possibility of freezing and sticking. For this reason, the problem is how to prevent the throttle valve from freezing and sticking.

  For the purpose of solving these two problems, for example, as shown in FIGS. 4 and 5, the internal structure of the throttle body 101 includes a bore inner pipe 102 through which intake air that flows toward each cylinder of the engine flows, The bore inner pipe 102 has a double pipe structure in which a bore outer pipe 103 for forming an annular space between the bore inner pipe 102 and the bore inner pipe 102 is disposed on the radially outer diameter side of the bore inner pipe 102. By floating from the bore outer pipe 103 that forms the outer shell of the body 101, moisture transmitted from the inner peripheral surface of the upstream engine intake pipe is trapped in the annular space, and the throttle valve 104 is connected to the bore inner pipe 102. Prevents freezing and sticking to the bore inner surface. At the same time, a reduction in cost and weight is also achieved by making the throttle body 101 resin (see, for example, Patent Document 1). When the throttle body 101 is made of resin, the deformation of the throttle body 101 after resin molding (molding shrinkage and distortion due to assembly) does not directly affect the bore inner diameter of the bore inner tube 102. The accuracy of the bore inner diameter of the bore inner tube 102 can be improved. Here, reference numeral 105 denotes a motor housing integrally formed on the outer peripheral portion of the bore outer tube 103 via a connecting rib 106, and 107 denotes a sensor cover.

[Conventional technical problems]
However, in the double pipe structure of the throttle body 101 described in Patent Document 1, when the throttle valve 104 is fully closed, as shown in FIGS. 6 and 7A, the outer peripheral portion of the bore inner pipe 102 and the bore A connection rib (bore inner / outer tube connecting portion) 109 connecting the inner periphery of the outer tube 103 is in contact with the outer periphery of the throttle valve 104 and the bore inner surface of the bore inner tube 102 (shown in FIG. 7A). If it overlaps with the hatched portion), deformation caused by molding shrinkage of the bore outer tube 103 of the throttle body 101 having a double tube structure or distortion caused when the mounting stay 110 formed integrally with the resin of the bore outer tube 103 is assembled to the vehicle. The influence propagates to the bore inner tube 102, and the effect of improving the accuracy of the bore inner diameter of the bore inner tube 102 is reduced. Accordingly, there is a problem that the roundness of the bore inner diameter of the bore inner tube 102 is lowered, and the amount of intake air leakage during idle operation is increased.

Further, when the throttle valve 104 is fully opened, as shown in FIGS. 6 and 7B, the outer diameter side end surface of the throttle valve 104 in the radial direction (the outer diameter at the position farthest from the rotation shaft axis of the throttle shaft). When the side end face (111) is located so as to protrude from both end faces (annular end faces) 112 in the central axis direction (tube direction) of the bore inner pipe 102, a discontinuous opening area in the course of the rotation operation of the throttle valve 104 There is a problem that it becomes difficult to obtain a predetermined valve opening flow rate characteristic in which the intake air amount continuously increases as the valve angle (valve opening) of the throttle valve 104 increases.
JP 09-032590 (page 1-7, FIGS. 1-6)

  An object of the present invention is to achieve high accuracy of the clearance dimension between the bore inner diameter surface of the bore inner pipe and the outer peripheral portion of the throttle valve by eliminating the influence on the accuracy of the bore inner diameter of the bore inner pipe. It is an object of the present invention to provide a throttle control device for an internal combustion engine that can be used. In addition, by preventing the opening / closing of the discontinuous opening area during the rotation of the throttle valve, a predetermined valve opening flow rate characteristic in which the amount of intake air continuously increases as the rotation angle of the throttle valve increases is obtained. It is an object to provide a throttle control device for an internal combustion engine that can be obtained.

  According to the first aspect of the present invention, the bore inner / outer pipe connecting portion for connecting the outer peripheral portion of the bore inner tube and the inner peripheral portion of the bore outer tube of the throttle body having a double pipe structure to the resinized throttle body is provided. It is formed integrally. When the above-mentioned bore inner / outer pipe connecting portion is set to the fully closed position where the intake air amount is minimized, the throttle valve (the outer peripheral portion or the outer diameter side end portion) is connected to the bore inner pipe. Displacement due to molding shrinkage of the outer pipe of the bore of a double-pipe throttle body or distortion caused when assembling a throttle pipe of a double-pipe structure in a vehicle by installing it avoiding the area that contacts or approaches the bore inner surface Is less likely to propagate to the bore inner tube via the bore inner / outer tube connecting portion. As a result, the accuracy of the bore inner diameter of the bore inner pipe can be eliminated, so that the accuracy of the gap dimension between the bore inner diameter surface of the bore inner pipe and the outer periphery of the throttle valve can be realized. it can. Accordingly, the roundness of the bore inner diameter of the bore inner pipe can be improved and the amount of intake air leakage during idle operation can be reduced, so that the airtight performance when the valve is fully closed can be ensured.

  According to the second aspect of the present invention, the resin-made throttle body is integrally formed with a housing that accommodates the actuator therein, and a housing connecting portion that connects the outer peripheral portion of the bore outer tube and the outer peripheral portion of the housing. doing. Then, by installing the bore inner / outer pipe connecting portion away from the connecting portion between the housing connecting portion and the outer peripheral portion of the bore outer tube, the influence of deformation or the like due to molding shrinkage of the housing can be reduced. It becomes difficult to propagate to the bore inner pipe through the inner and outer pipe connecting portions. Thereby, the effect of the invention of claim 1 can be further improved.

  According to the third aspect of the present invention, when the valve is fully opened to set the throttle valve to the fully opened position where the intake air amount is maximum, the throttle valve (the outer peripheral portion or the outer diameter side end portion) is made of resin. It is installed so as not to protrude from both end faces in the central axis direction of the bore inner pipe of the throttle pipe structure of the heavy pipe structure. That is, when the throttle valve is set to the fully open position where the amount of intake air is maximized, the throttle valve (the outer peripheral portion or the outer diameter side end portion) is connected from either end surface in the central axis direction of the bore inner pipe. By retracting and installing, it is possible to prevent a discontinuous increase / decrease in the opening area during the rotation operation of the throttle valve. As a result, it is possible to obtain a predetermined valve opening flow rate characteristic in which the intake air amount continuously increases as the rotation angle of the throttle valve increases.

  According to the fourth aspect of the present invention, when the valve is fully opened to set the throttle valve at the fully opened position where the intake air amount is maximized, the throttle valve (the outer peripheral portion or the outer diameter side end portion) has a double pipe structure. The throttle body is installed so as not to protrude from either end face in the central axis direction of the bore inner pipe of the throttle body. That is, when the throttle valve is set to the fully open position where the amount of intake air is maximized, the throttle valve (the outer peripheral portion or the outer diameter side end portion) is connected from either end surface in the central axis direction of the bore inner pipe. By retracting and installing, it is possible to prevent a discontinuous increase / decrease in the opening area during the rotation operation of the throttle valve. As a result, it is possible to obtain a predetermined valve opening flow rate characteristic in which the intake air amount continuously increases as the rotation angle of the throttle valve increases.

  According to the invention described in claim 5, the outer diameter dimension in the diameter direction of the throttle valve is set shorter than the pipe length dimension in the central axis direction of the bore inner pipe of the throttle body having a double pipe structure. The optimum dimensional relationship between the throttle valve when the valve is fully opened and the bore inner pipe of the throttle body having a double pipe structure can be realized. According to the sixth aspect of the present invention, the rotation center axis of the throttle valve substantially divides the tube length dimension in the direction of the center axis of the bore inner tube of the throttle body having a double-pipe structure. By installing the throttle valve in the bore inner pipe so that it passes through the intermediate point, the optimum dimensional relationship between the throttle valve when the valve is fully opened and the bore inner pipe of the double-pipe throttle body can be realized. it can.

  According to the seventh aspect of the present invention, the throttle valve has a rotation center axis in a direction substantially orthogonal to the center axis direction of the bore inner pipe, and the intake air is introduced from the fully closed position where the intake air amount is minimized. You may employ | adopt the butterfly valve from which a rotation angle is changed to the full open position where quantity becomes the maximum. The space for rotating the butterfly valve may be secured inside the bore inner pipe. Further, the butterfly valve may be formed not only in a disc shape but also in an elliptical shape, an oval shape, or a rectangular shape. However, the long diameter or the long side is located in a direction substantially parallel to the rotation center axis direction of the butterfly valve, and the short diameter or the short side is located in a direction substantially orthogonal to the rotation center axis direction of the butterfly valve. To form. Note that the cross-sectional shape of the bore inner tube may be changed in accordance with the change in the outer shape of the butterfly valve.

  The best mode for carrying out the present invention is to achieve a high accuracy of the clearance dimension between the bore inner diameter surface of the bore inner pipe and the outer peripheral portion of the throttle valve. Realized by eliminating the effect on accuracy. In addition, the purpose of obtaining a predetermined valve opening flow rate characteristic in which the amount of intake air continuously increases as the rotation angle of the throttle valve increases is to increase or decrease the discontinuous opening area in the process of rotating the throttle valve. Realized by preventing.

[Configuration of Example 1]
1 to 3 show a first embodiment of the present invention, FIG. 1 is a diagram showing a schematic structure of a throttle body having a double-pipe structure, and FIG. 2 is an overall structure of a throttle control device for an internal combustion engine. FIG.

  The throttle control device for an internal combustion engine of this embodiment is mounted on a vehicle such as an automobile, for example, and adjusts the amount of intake air directed to each cylinder (cylinder) of an internal combustion engine (hereinafter referred to as an engine) such as a gasoline engine. 1, a drive motor 3 that rotationally drives a throttle shaft 2 that operates integrally with the throttle valve 1, and a double-pipe structure that rotatably accommodates the throttle valve 1 and supports the throttle shaft 2 rotatably. The throttle body 4 and an engine control device (engine control unit: hereinafter referred to as ECU) that controls the valve opening (throttle opening) of the throttle valve 1 according to the accelerator operation amount of an operator such as a vehicle occupant (driver, driver). An intake control device for an internal combustion engine.

  The throttle valve 1 of the present embodiment is a substantially circular shape having a rotation center axis in a direction substantially perpendicular to the center axis direction of the cylindrical bore inner pipe 5 and the cylindrical bore outer pipe 6 of the throttle body 4 having a double pipe structure. The plate-shaped butterfly valve changes the rotation angle in the rotational operation range from the fully closed position where the amount of intake air is minimum to the fully open position where the amount of intake air is maximum. Control the amount. As shown in FIG. 3, the throttle valve 1 is biased in a direction to return to the fully closed position by a coil spring 10. The throttle valve 1 is constituted by a disk-shaped portion (resin disk) centering on the intersection of the central axis of the bore inner tube 5 and the rotation central axis of the throttle valve 1. The resin molded portion of the throttle valve 1 is integrally formed of a resin material such as a thermoplastic resin (heat-resistant resin: for example, polyphenylene sulfide: PPS, or polyamide resin: PA, or polypropylene: PP, or polyetherimide: PEI). Is formed.

  The throttle valve (disk-shaped part) 1 is in contact with the bore inner diameter surface of the bore inner pipe 5 when the valve is fully closed. The throttle valve 1 is set to a fully closed position where the amount of intake air is minimized. Outer diameter side end surfaces (outer diameter side end portions) 11 and 12 are provided. The semicircular plate-like portion on one end side of the throttle valve 1 is at one end side in the central axial direction of the bore inner pipe 5 (for example, the intake side) when the valve is fully opened to set the throttle valve 1 to the fully open position where the intake air amount is maximum. It is provided on the other end side in the radial direction of the cylindrical portion 15 so as to be located on the upstream side in the air flow direction. Further, the semicircular plate-like portion on the other end side of the throttle valve 1 is positioned on the other end side in the central axis direction of the bore inner tube 5 (for example, downstream in the flow direction of intake air) when the valve is fully opened. The other end side of the cylindrical portion 12 in the radial direction is provided. A reinforcing rib (not shown) for reinforcing the disk-shaped portion is integrally formed by resin molding on one end surface (for example, the upstream side surface in the intake air flow direction) or both end surfaces of the throttle valve 1. Has been. The cylindrical portion 15 of the throttle valve 1 is integrally formed by resin molding on the outer periphery of the valve holding portion of the throttle shaft 2. As a result, the throttle valve 1 and the throttle shaft 2 can be integrated and rotated integrally.

  Here, in this embodiment, as shown in FIG. 1A, when the valve is fully opened, the outer diameter side end surfaces 11 and 12 of the disc-shaped portion of the throttle valve 1 are connected to the central axis of the bore inner tube 5. It is installed so as not to protrude from either of both end faces (annular end faces) 13 and 14 in the direction. That is, when the valve is fully opened, the outer diameter side end surfaces 11 and 12 of the disc-shaped portion of the throttle valve 1 are installed so as to be retracted from both the annular end surfaces 13 and 14 of the bore inner pipe 5. This is because the outer diameter dimension in the diameter direction of the throttle valve 1 is set shorter than the pipe length dimension in the central axis direction of the bore inner pipe 5, and the rotation central axis line of the throttle valve 1 is in the direction of the central axis direction of the bore inner pipe 5. The throttle valve 1 is installed in the bore inner pipe 5 so as to pass through a substantially middle point of the bore inner pipe 5 which divides the pipe length dimension into two. Alternatively, the throttle valve 1 is installed in the bore inner pipe 5 so that the rotational operation space of the throttle valve 1 (the rotation locus of the throttle valve 1 from the fully closed position to the fully opened position) does not protrude from the bore inner pipe 5.

  The throttle shaft 2 is a metal shaft (rotary shaft) formed of a metal material such as brass or stainless steel in the shape of a round shaft, and is substantially orthogonal to the central axis directions of the bore inner tube 5 and the bore outer tube 6. The rotation center axis direction (axial direction) is set so as to be parallel to the central axis direction of the motor housing 7 integrally molded with resin on the outer wall portion of the bore outer tube 6 of the throttle body 4. ing. Here, the throttle shaft 2 of the present embodiment has a valve holding portion that holds and fixes the cylindrical portion 15 of the throttle valve 1, reinforces the throttle valve 1, and rotates the throttle valve 1 inside the cylindrical portion 15. Insert molding is performed so as to penetrate the central axis direction (diameter direction).

  Further, the throttle shaft 2 has one end portion of the rotation center axis (axial direction) exposed (protruded) from the annular end surface on one end side of the cylindrical portion 15 of the throttle valve 1, and the first valve bearing of the throttle body 4. It functions as a first bearing sliding portion that slides rotatably in a first bearing (not shown) held and fixed to the portion 16. Further, the other end portion of the rotation center axis (axial direction) of the throttle shaft 2 is exposed (protruded) from the annular end surface on the other end side of the cylindrical portion 15 of the throttle valve 1, and the second valve bearing of the throttle body 4. It functions as a second bearing sliding portion that slides rotatably in a second bearing (not shown) that is held and fixed to a portion (not shown). A valve gear 17 that is one of the components of the gear reduction device is integrally formed at the right end (other end) of the throttle shaft 2 in the figure.

  Here, the ECU opens the accelerator opening sensor that converts the accelerator operation amount (accelerator pedal depression amount) by the driver into an electric signal (accelerator opening signal) and outputs to the ECU how much the accelerator pedal is depressed. (Not shown) is connected. The throttle control device for an internal combustion engine converts the valve opening (rotation angle, valve angle) of the throttle valve 1 into an electrical signal (throttle opening signal), and outputs to the ECU how much the throttle valve 1 is open. A rotation angle sensor (throttle position sensor). Then, the ECU of this embodiment performs proportional-integral-derivative control (PID control) on the drive motor 3 so that there is no deviation between the throttle opening signal from the rotation angle sensor and the accelerator opening signal from the accelerator opening sensor. Is configured to perform feedback control.

  Here, the rotation angle sensor is a throttle opening sensor that detects a throttle opening (throttle position) corresponding to the rotation angle (valve angle) of the throttle valve 1, and is integrally attached to one end of the throttle shaft 2. And a non-contact type magnetic detection element (not shown) that generates an electromotive force in response to the magnetic field generated from the magnetic field generation source. A split permanent magnet (magnet) 19 is used as the magnetic field generation source. In addition, the magnet 19 and a split yoke magnetized by the magnet 19 (magnetic body: not shown) use an adhesive or the like on the inner peripheral surface of the valve gear 17 that is one of the components of the gear reduction device. It is fixed. As the magnetic detection element, a Hall IC, a Hall element, or a magnetoresistive element is used. The magnetic detection element is held and fixed to the sensor mounting portion of the sensor cover 9 assembled to the outer wall portion of the throttle body 4 so as to face the inner peripheral surface of the yoke.

  Here, the power unit that opens or closes the throttle valve 1 is driven by a drive motor 3 that is a power source and power transmission that transmits the rotational power of the drive motor 3 to the throttle valve 1 via the throttle shaft 2. And a device (gear reduction device). The drive motor 3 is integrally connected to a motor energization terminal embedded in the sensor cover 9, and when energized, a motor shaft (not shown) rotates in the forward direction or the reverse direction. Actuator (drive source). The front end frame of the drive motor 3 is fastened and fixed around the motor insertion opening of the cylindrical motor housing 7 using a fastener 20 such as a fastening screw.

  The gear reduction device reduces the rotation speed of the drive motor 3 to a predetermined reduction ratio, and a pinion gear 21 fixed to the outer periphery of the motor shaft of the drive motor 3 and an intermediate portion that meshes with the pinion gear 21 and rotates. It has a reduction gear 22 and a valve gear 17 that meshes with and rotates with the intermediate reduction gear 22. The pinion gear 21 is a motor gear that is integrally formed in a predetermined shape with a metal material and rotates integrally with the motor shaft of the drive motor 3. The intermediate reduction gear 22 is integrally formed in a predetermined shape with a resin material, and is rotatably fitted to the outer periphery of a support shaft 23 that forms the center of rotation. The intermediate reduction gear 22 is provided with a large-diameter gear 24 that meshes with the pinion gear 21 and a small-diameter gear 25 that meshes with the valve gear 17.

  Further, the support shaft 23 is integrally formed by resin molding on the bottom wall surface of the gear box 8, and a tip portion thereof is fitted in a concave portion formed on the inner wall surface of the sensor cover 9. The valve gear 17 is integrally formed of a resin material into a predetermined substantially annular shape, and a gear portion (tooth portion) 26 that meshes with the small diameter gear 25 of the intermediate reduction gear 22 is integrally formed on the outer peripheral surface of the valve gear 17. Has been. Note that the outer peripheral portion of the valve gear 17, that is, one end surface in the circumferential direction of the gear portion 26, is engaged with a fully closed stopper 27 formed integrally with the gear box 8 when the throttle valve 1 is closed to the fully closed position. A fully-closed stopper portion 29 is integrally formed as a locked portion to be stopped.

  The throttle body 4 of the present embodiment is made of a predetermined material by a resin material such as a thermoplastic resin (heat resistant resin: for example, polyphenylene sulfide: PPS, or polyamide resin: PA, or polypropylene: PP, or polyetherimide: PEI). It is formed integrally with the shape. The throttle body 4 made of resin in this manner has a cylindrical bore inner pipe (inner diameter side cylindrical portion forming the bore inner diameter) 5 and a cylindrical bore on the radially outer diameter side of the bore inner pipe 5. The throttle body 4 has a double-pipe structure in which an outer pipe (an outer diameter side cylindrical portion that forms an outline of the throttle body 4) 6 is disposed. The throttle body 4 is a device that rotatably holds the throttle valve 1 within the bore inner diameter (intake air passage) of the bore inner tube 5. The throttle body 4 is sucked into an air inlet (intake air passage) for sucking intake air from an air cleaner (not shown) through an engine intake pipe (not shown), and a surge tank or intake manifold of the engine. A resin having an air outlet (intake air passage) for inflowing air and having substantially the same inner and outer diameters in the flow direction of the intake air (the direction from the upper end side in the drawing toward the lower end side in the drawing). It is integrally formed by molding.

  The bore inner pipe 5 accommodates the throttle valve 1 in an openable and closable manner, and is formed with a circular intake air passage 31 through which intake air drawn into each cylinder of the engine flows in the direction of the central axis. A cylindrical space (cylindrical space) formed between the bore inner tube 5 and the bore outer tube 6 is partitioned by an annular plate-like connecting portion 32. The annular plate-like connecting portion 32 is substantially the entire circumference at a part of the cylindrical space, that is, substantially at the center of the cylindrical space (in the radial direction of the axial center portion of the throttle shaft 2 near the fully closed position of the throttle valve 1). It functions as an annular connecting portion (bore inner / outer tube connecting portion) that connects the outer peripheral portion of the bore inner tube 5 and the inner peripheral portion of the bore outer tube 6 so as to be closed. The cylindrical space on the upstream side of the annular plate-like connecting portion 32 is a blocking recess (moisture trap groove) 33 for blocking moisture flowing in along the inner peripheral surface of the engine intake pipe. ing. The cylindrical space on the downstream side of the annular plate-like connecting portion 32 is a blocking recess (moisture trap groove) 34 for blocking moisture flowing in along the inner peripheral surface of the intake manifold. Yes.

  Here, as shown in FIG. 1 (b), the annular plate-like connecting portion 32 of the present embodiment has an outer diameter side end face of the throttle valve 1 when the throttle valve 1 is set to a fully closed position. The outer diameter side ends (11, 12) are installed so as to avoid a range in contact with or approaching the bore inner diameter surface of the bore inner tube 5. In the present embodiment, for example, the annular plate-like connecting portion 32 is connected to the downstream end portion (lower end portion in the figure) of the bore inner tube 5 so that the inner volume of the blocking recess 33 is larger than that of the blocking recess 34. ) And the inner peripheral portion of the downstream end portion (lower end portion in the figure) of the bore outer tube 6 are connected. An annular plate-like connecting portion 32 that connects the outer peripheral portion of the bore inner tube 5 and the inner peripheral portion of the bore outer tube 6 is a rectangular parallelepiped that connects the outer peripheral portion of the bore outer tube 6 and the outer peripheral portion of the motor housing 7. The connecting portion between the cylindrical connecting portion 42 and the outer peripheral portion of the bore outer pipe 6 may be avoided.

  The bore inner tube 5 and the bore outer tube 6 have substantially cylindrical first and second valve bearing portions 16 that rotatably support the first and second bearing sliding portions at both ends of the throttle shaft 2. Resin integrated molding. A plug (not shown) for closing the opening side of the first valve bearing portion 16 is attached to the opening side end portion of the first valve bearing portion 16. The second valve bearing portion is integrally formed so as to protrude from the outer wall surface of the throttle body 4, that is, the bottom wall surface of the gear box 8 toward the right in the figure, and the outer peripheral portion thereof is formed by the coil spring 10. It functions as a spring inner peripheral guide (not shown) that holds the inner diameter side of the coil.

  On the outer wall portion of the bore outer tube 6, a gear box 8 for accommodating the gear reduction device inside and a cylindrical motor housing (actuator housing) 7 for accommodating and fixing the drive motor 3 therein are resin-molded. Are integrally formed. Further, the outer peripheral portion of the bore outer tube 6 on the other end side (the lower end side in the figure) in the central axis direction is coupled to the coupling end surface of the intake manifold of the engine by using a fastener (not shown) such as a fastening bolt. A substantially annular (saddle-shaped) mounting stay portion 35 is integrally formed by resin molding. The mounting stay portion 35 is provided so as to protrude from the outer wall surface of the lower end portion of the bore outer tube 6 to the outer diameter side in the radial direction, and is inserted in a round hole shape through which a fastener such as the fastening bolt is inserted. A plurality of holes 36 are formed. Furthermore, an undercut portion (concave groove) 37 communicating with a part of the insertion holes 36 among the plurality of insertion holes 36 is formed on the outer peripheral surface of the mounting stay portion 35.

  The motor housing 7 has a motor housing hole (not shown) for housing and holding the drive motor 3 therein, and has a radius on the side wall surface of the bore outer tube 6 of the throttle body 4 with respect to the central axis direction of the throttle body 4. A parallelepiped connection portion (connection rib) 42 is connected in parallel to the outer diameter side in the direction. The motor housing 7 is integrally formed of the same resin material as the throttle body 4 and is connected to the left end surface of the container-shaped gear box 8 for rotatably housing the gears of the gear reduction device. Yes. The rectangular parallelepiped connecting portion 42 functions as a housing connecting portion that connects the outer peripheral portion of the bore outer tube 6 and the outer peripheral portion of the motor housing 7. The motor housing 7 includes a substantially cylindrical side wall 43 extending leftward from the left end surface of the gear box 8 in the figure, and a substantially annular bottom that closes the left side opening side of the side wall 43 in the figure. A wall 44 is provided. The central axis direction of the side wall 43 of the motor housing 7 is set to be parallel to the axial direction of the throttle shaft 2 (rotational central axis direction of the throttle valve 1). It is set in a direction substantially orthogonal to the central axis direction.

  The gear box 8 is integrally formed of the same resin material as that of the throttle body 4, and forms a gear chamber in which each gear constituting the gear reduction device is rotatably accommodated. Further, on the inner wall surface of the gear box 8, a full-close stopper 27 for restricting the rotation operation of the throttle valve 1 in the full-close direction at the full-close position of the throttle valve 1 is integrally formed by resin molding. Yes. Note that a full-open stopper for restricting the rotational operation of the throttle valve 1 in the fully-open direction at the fully-open position of the throttle valve 1 may be integrally formed on the inner wall surface of the gear box 8 by resin molding. The sensor cover 9 is formed in a predetermined shape by a resin material such as a thermoplastic resin that can electrically insulate between the terminals of the rotation angle sensor described above and between the energization terminals for the motor to the drive motor 3. Yes. The sensor cover 9 has a fitted portion to be fitted to a fitting portion provided on the opening side of the gear box 8, and the opening of the gear box 8 is formed by rivets, screws (not shown), heat caulking, or the like. It is assembled at the side edge. The sensor cover 9 is integrally molded with a cylindrical connector receiving portion 45 to which a connector (not shown) is connected.

[Operation of Example 1]
Next, the operation of the throttle control device for an internal combustion engine of the present embodiment will be briefly described with reference to FIGS.

  When the driver (driver) steps on the accelerator pedal, an accelerator opening signal is input to the ECU from the accelerator opening sensor. The drive motor 3 is energized so that the throttle valve 1 is at a predetermined angle by the ECU, and the motor shaft of the drive motor 3 rotates. Then, the torque of the drive motor 3 is transmitted to the pinion gear 21, the intermediate reduction gear 22 and the valve gear 17. As a result, the valve gear 17 rotates a rotation angle corresponding to the amount of depression of the accelerator pedal against the urging force of the coil spring 10. Accordingly, since the valve gear 17 rotates, the throttle shaft 2 rotates at the same rotation angle as that of the valve gear 17, and the throttle valve 1 is rotationally driven in a direction (a fully open direction) that opens from the fully closed position to the fully open position. As a result, the intake air passage 31 formed in the bore pipe 5 of the throttle body 4 is opened by a predetermined angle, so that the rotational speed of the engine is changed to a speed corresponding to the depression amount of the accelerator pedal.

  Conversely, when the driver removes his / her foot from the accelerator pedal, the throttle valve 1, the throttle shaft 2, the valve gear 17 and the accelerator pedal are moved to their original positions (idling position, throttle valve 1 fully closed position) by the biasing force of the coil spring 10. Is returned to. When the driver returns the accelerator pedal, an accelerator opening signal (0%) is output from the accelerator opening sensor, so that the ECU 3 controls the drive motor 3 so that the throttle valve 1 reaches the opening when the valve is fully closed. You may make it reversely rotate the motor shaft of the drive motor 3 by supplying with electricity. In this case, the throttle valve 1 can be rotationally driven by the drive motor 3 in the fully closed direction. At this time, the direction in which the throttle valve 1 is closed from the fully open position side to the fully closed position side by the urging force of the coil spring 10 until the fully closed stopper portion 29 provided in the valve gear 17 contacts the fully closed stopper 27 (fully closed direction). Rotate to. Further, since the further closing operation of the throttle valve 1 in the fully closed direction is restricted by the fully closed stopper 27, the throttle valve 1 is placed in the intake air passage 31 formed in the bore inner pipe 5 of the throttle body 4. It is held in a predetermined fully closed position. Thereby, the intake air passage 31 to the engine is fully closed, and the rotational speed of the engine becomes the idle rotational speed.

[Effect of Example 1]
As described above, in the throttle control device for an internal combustion engine of the present embodiment, as shown in FIG. 1A, the outer diameter side end surfaces 11 and 12 of the throttle valve 1 have a double pipe structure when the valve is fully opened. The throttle valve 1 can be freely opened and closed in the intake air passage 31 of the bore inner pipe 5 so as not to protrude from both end faces (annular end faces 13, 14) in the central axis direction of the bore inner pipe 5 of the throttle body 4. Is housed in. That is, when the valve is fully opened, the outer diameter side end surfaces 11 and 12 of the throttle valve 1 are installed by being retracted from both the annular end surfaces 13 and 14 of the bore inner tube 5. Thus, it is possible to prevent a discontinuous increase / decrease in the opening area. As a result, it is possible to obtain a predetermined valve opening flow rate characteristic in which the intake air amount continuously increases as the rotation angle of the throttle valve 1 increases.

  Further, as shown in FIG. 1B, an annular plate-like connecting portion 32 that connects the outer peripheral portion of the bore inner tube 5 and the inner peripheral portion of the bore outer tube 6 of the throttle body 4 having a double pipe structure is provided. When the valve is fully closed, avoid the range where the outer diameter side end surfaces (outer diameter side end portions) 11 and 12 of the throttle valve 1 are in contact with the bore inner diameter surface of the bore inner pipe 5 (the hatched portion shown in FIG. 1B). Installed. Accordingly, when the deformation of the bore outer tube 6 of the throttle body 4 is deformed due to the contraction and the mounting stay 35 of the bore outer tube 6 is fastened and fixed to the coupling end surface of the intake manifold of the engine by using a fastener such as a fastening bolt. Therefore, it is difficult to propagate the influence of the distortion generated on the bore inner pipe 5 from the bore outer pipe 6 through the annular plate-like connecting portion 32. Note that the annular plate-like connecting portion 32 described above avoids a connecting portion between the rectangular parallelepiped connecting portion 42 that connects the outer peripheral portion of the bore outer tube 6 and the outer peripheral portion of the motor housing 7 and the outer peripheral portion of the bore outer tube 6. When the motor housing 7 is installed, the influence of deformation or the like accompanying the molding shrinkage of the motor housing 7 is transferred from the motor housing 7 to the bore inner tube 5 through the rectangular parallelepiped connection portion 42, the bore outer tube 6, and the annular plate connection portion 32. Difficult to propagate. This eliminates the influence on the accuracy of the bore inner diameter of the bore inner tube 5, so that the bore inner diameter surface of the bore inner tube 5 and the outer diameter side end surface (outer diameter side end of the throttle valve 1) when the valve is fully closed. Part) 11, 12, it is possible to achieve high accuracy of the gap dimension. Therefore, the roundness of the bore inner diameter of the bore inner tube 5 can be improved and the amount of intake air leakage during idle operation can be reduced, so that the airtight performance when the valve is fully closed can be ensured.

  Further, in the throttle control apparatus for an internal combustion engine of the present embodiment, as shown in FIGS. 1 and 2, the annular plate-like connection portion 32 is more closed than the blocking recess 34. The outer peripheral portion of the downstream end portion (lower end portion in the figure) of the bore inner tube 5 and the inner peripheral portion of the downstream end portion (lower end portion in the figure) of the bore outer tube 6 are connected so that the inner volume becomes larger. Are arranged as follows. As a result, it is possible to prevent moisture that has reached the throttle body 4 from being transmitted through the inner peripheral surface of the engine intake pipe and blocked by the blocking recess 34 and reaching the throttle valve 1. Further, since the amount of moisture blocked in the blocking recess 33 is increased as compared with the conventional technique, the moisture blocked in the blocking recess 33 causes the annular end surface 13 of the bore inner tube 5 to be blocked. It is possible to prevent the vehicle from getting over and reaching the throttle valve 1. Therefore, it is possible to prevent the throttle valve 1 from being frozen and fixed to the bore inner diameter surface of the bore inner pipe 5, and at the same time, by making the throttle valve 1 and the throttle body 4 resin, it is possible to reduce the cost and weight. .

[Modification]
In the present embodiment, the present invention transmits the rotational power of the drive motor (actuator) 3 to the throttle shaft 2 via a power transmission device such as a gear reduction device, so that the rotational angle (valve opening) of the throttle valve 1 is determined. Although the example applied to the throttle control device for an internal combustion engine that controls according to the accelerator operation amount of the driver (driver) has been described, the present invention may be applied to a throttle device for an internal combustion engine that does not have the drive motor 3. . In this case, instead of the valve gear 17 provided at the other end of the throttle shaft 2, a lever portion that is mechanically connected to the accelerator pedal via a wire cable is provided. Even in this way, the accelerator operation amount of the driver (driver) can be transmitted to the throttle valve 1.

  In the present embodiment, the throttle body 4 has a cylindrical bore inner tube 5 disposed in a cylindrical bore outer tube 6 and the bore inner tube 5 and the bore outer tube 6 are disposed concentrically. A double pipe in which the central axis of the bore inner pipe 5 is decentered with respect to the central axis of the outer pipe 6 on one side in the radial direction perpendicular to the central axis direction of the throttle body 4 (for example, the ground side in the vertical direction). You may form in a structure. In addition, the throttle body 4 has a cylindrical bore inner tube 5 disposed in the cylindrical bore outer tube 6, and the center axis of the bore inner tube 5 is set to the throttle body 4 with respect to the center axis of the bore outer tube 6. It may be formed in a double tube structure that is eccentric to the other side in the radial direction perpendicular to the central axis direction (for example, the top side in the vertical direction). Further, the throttle valve 1 is manufactured from a resin material or a metal material, and is inserted into a valve insertion hole formed in the valve holding portion of the throttle shaft 2, and the throttle valve 1 is attached to the valve holding portion of the throttle shaft 2 with a fastening screw or the like. It may be fastened and fixed using a fastener.

  In this embodiment, without introducing engine cooling water into the throttle body 4, the throttle valve 1 is prevented from icing during cold weather such as in winter, and the number of parts is reduced upstream and downstream of the throttle valve 1. Blocking recesses 33 and 34 for blocking water flowing into the throttle body 4 from the side are provided, but at least along the inner peripheral surface of the engine intake pipe upstream of the throttle valve 1, the throttle body Only the blocking recess 33 for blocking the moisture flowing into 4 may be provided. Further, an idle rotation speed control for providing a bypass passage that bypasses the throttle valve 1 on the outer peripheral portion of the bore outer pipe 6 and controlling the engine idle rotation speed by adjusting the amount of air flowing through the bypass passage. A valve (ISC valve) may be attached.

  Further, an outlet hole of the blow-by gas reduction device (PCV) or a purge tube of the transpiration prevention device may be attached to the engine intake pipe upstream of the throttle body 4 in the flow direction of the intake air. In this case, there is a possibility that the engine oil contained in the blow-by gas accumulates on the inner wall surface of the engine intake pipe in the engine intake pipe and becomes a deposit. For this reason, it is possible to prevent malfunction of the throttle valve 1 and the throttle shaft 2 by blocking foreign matter such as oil mist and deposit transmitted from the inner wall surface of the engine intake pipe in the blocking recess 33.

  Further, as a resin material for integrally forming the throttle body 4 with resin, a heated resin material (for example, a molten resin made of a thermoplastic resin) and a filler (for example, low-cost glass fiber, carbon fiber, aramid fiber, A resin-based composite material (for example, polybutylene terephthalate containing 30% glass fiber: PBTG30) mixed with boron fiber or the like may be used. Further, as a resin material for integrally molding the throttle valve 1 with resin, a heated resin material (for example, a molten resin made of thermoplastic resin) and a filler (for example, low-cost glass fiber, carbon fiber, aramid fiber, A resin-based composite material (for example, polybutylene terephthalate containing 30% glass fiber: PBTG30) mixed with boron fiber or the like may be used.

  In this embodiment, a fully closed stopper portion 29 provided on a valve gear (rotating body) 17 capable of rotating integrally with the throttle valve 1 and the throttle shaft 2 is a gear box in which the throttle body 4 is integrally molded with resin. The throttle valve 1 is locked by a fully-closed stopper 27 to restrict the rotational operation of the throttle valve 1 in the fully-closed direction. However, the rotational operation of the throttle valve 1 in the fully-closed direction may be restricted by being locked by a fully-closed stopper integrally molded with the resin on the bore inner surface of the bore inner tube 5 of the throttle body 4.

  In this embodiment, when the rotation angle of the throttle valve 1 becomes a valve angle corresponding to the fully open position, the motor drive current to the drive motor 3 is controlled to restrict the rotation operation of the throttle valve 1 in the fully open direction. However, the valve gear (rotating body) 17 that can rotate integrally with the throttle valve 1 and the throttle shaft 2 is provided with a fully open stopper portion, and the fully open stopper portion is provided in the gear box 8. , The rotation operation of the throttle valve 1 in the fully open direction may be restricted. In addition, one end surface or both end surfaces of the disc-shaped portion of the throttle valve 1 are locked by a fully-open stopper formed integrally with the bore of the bore inner tube 5 of the throttle body 4 so that the throttle valve 1 You may make it control the rotation operation of a full open direction.

(A), (b) is explanatory drawing which showed schematic structure of the throttle body of a double pipe structure (Example 1). 1 is a perspective view showing an overall structure of a throttle control device for an internal combustion engine (Example 1). FIG. (Example 1) which is the front view which showed the motive power unit which performs valve opening drive or valve drive of a throttle valve. It is the perspective view which showed the whole structure of the throttle control apparatus for internal combustion engines (prior art). It is the perspective view which showed the throttle body of the double pipe structure which accommodated the throttle valve so that opening and closing was possible (prior art). It is the perspective view which showed the double pipe connection structure (conventional technique). (A), (b) is explanatory drawing which showed schematic structure of the throttle body of a double pipe structure (conventional technique).

Explanation of symbols

1 Throttle valve (disc-shaped part, butterfly valve)
2 Throttle shaft (rotating shaft)
3 Drive motor (actuator)
4 Throttle body 5 Bore inner pipe 6 Bore outer pipe 7 Motor housing (actuator housing)
8 Gearbox 9 Sensor cover 11 Throttle valve outer diameter side end face (outer diameter side end)
12 Throttle valve outer diameter side end face (outer diameter side end)
13 Both end faces of the bore inner pipe in the direction of the central axis (annular end faces)
14 Both end faces of the bore inner pipe in the central axis direction (annular end faces)
15 Cylindrical part of throttle valve 32 Ring plate connection part (bore inner / outer pipe connection part)
42 Rectangular connection (housing connection)

Claims (7)

(A) a throttle valve that adjusts an intake air amount toward the cylinder of the internal combustion engine;
(B) A bore inner tube that accommodates the throttle valve in an openable / closable manner, and a bore outer tube for forming an annular space between the bore inner tube and the bore inner tube on the radially outer diameter side of the bore inner tube In a throttle control device for an internal combustion engine provided with a throttle body having a double pipe structure,
The throttle body is made of resin, and has a bore inner / outer pipe connecting portion that connects an outer peripheral portion of the bore inner tube and an inner peripheral portion of the bore outer tube,
The bore inner / outer pipe connecting portion sets the throttle valve to a fully closed position where the amount of intake air is minimized, and avoids a range where the throttle valve contacts or approaches the bore inner diameter surface of the bore inner pipe when the valve is fully closed. A throttle control device for an internal combustion engine characterized by being installed. The throttle control device for an internal combustion engine according to claim 1,
An actuator for changing the rotation angle of the throttle valve;
The throttle body has a housing that houses the actuator therein, and a housing connecting portion that connects an outer peripheral portion of the bore outer tube and an outer peripheral portion of the housing,
The throttle control device for an internal combustion engine, wherein the bore inner / outer pipe connecting portion is installed so as to avoid a connection portion between the housing connecting portion and an outer peripheral portion of the bore outer pipe. The throttle control device for an internal combustion engine according to claim 1 or 2,
The throttle valve is installed so that it does not protrude from either end face in the central axis direction of the bore inner pipe when the throttle valve is set to a fully open position where the intake air amount is maximum. A throttle control device for an internal combustion engine. (A) a throttle valve that adjusts an intake air amount toward the cylinder of the internal combustion engine;
(B) A bore inner tube that accommodates the throttle valve in an openable / closable manner, and a bore outer tube for forming an annular space between the bore inner tube and the bore inner tube on the radially outer diameter side of the bore inner tube In a throttle control device for an internal combustion engine provided with a throttle body having a double pipe structure,
The throttle valve is installed so that it does not protrude from either end face in the central axis direction of the bore inner pipe when the throttle valve is set to a fully open position where the intake air amount is maximum. A throttle control device for an internal combustion engine. In the throttle control device for an internal combustion engine according to claim 3 or 4,
2. A throttle control apparatus for an internal combustion engine, characterized in that an outer diameter dimension in a diameter direction of the throttle valve is set shorter than a pipe length dimension in a central axis direction of the bore inner pipe. The throttle control device for an internal combustion engine according to any one of claims 3 to 5,
The throttle valve is installed in the bore inner pipe so that the rotation center axis of the throttle valve passes through a substantially middle point of the bore inner pipe, which divides the length of the bore inner pipe in the direction of the center axis. A throttle control device for an internal combustion engine. The throttle control device for an internal combustion engine according to any one of claims 3 to 6,
The throttle valve has a rotation center axis in a direction substantially perpendicular to the center axis direction of the bore inner pipe,
A throttle control device for an internal combustion engine, wherein the rotation angle is changed from a fully closed position where the intake air amount is minimum to a fully open position where the intake air amount is maximum.

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