JP2005337190A - Intake air throttle for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase degree of freedom in design of layout of a suction pipe. <P>SOLUTION: The layout of the suction pipe capable of arbitrarily selecting generation of a tumble stream or a swirl stream in a combustion chamber of a 4-cycle gasoline engine for a two-wheeled vehicle and promotion of atomization of fuel spray injected from an injection hole of an injector 8 is constituted without changing a shape (changing design) of a throttle body 4 or an outlet duct 5 even when there is restriction in a positional relation of the throttle body 4 for the direction of advance of the vehicle from a viewpoint of vehicle structure by changing a mounting angle of the outlet duct 5 for the throttle body 4 continuously in the direction of pipe periphery of the throttle body 4. Consequently, air stream having comparatively high flow speed can be blown for a wall face on a ceiling side of a suction port 11 bent three-dimensionally without changing a mounting position of the throttle body 4 for the direction of advance of the vehicle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an intake throttle device for an internal combustion engine that controls an engine torque or an engine rotation speed by changing an intake air amount to an intake port of the internal combustion engine corresponding to a driver's accelerator operation amount or throttle operation amount. In particular, the present invention relates to a vortex generator for an internal combustion engine that secures the flow velocity and directionality of intake air flowing into an intake port of the internal combustion engine and generates vortex flow in a combustion chamber of the internal combustion engine to stabilize combustion.

[Conventional technology]
Conventionally, there is no surge tank between the downstream end of the throttle body and the intake port formed in the cylinder head of the engine. For example, in a two-wheeled vehicle engine, a slide valve in which the throttle valve is opened only from one side. By using a throttle valve of the type, the intake passage formed in the intake pipe connected to the downstream end of the throttle body is divided into two in the direction orthogonal to the flow direction of the intake air, so that the valve opening of the throttle valve can be reduced. An intake device for a two-wheeled vehicle engine that secures the flow velocity and direction of the intake air flowing into the intake port of a two-wheeled vehicle engine at a small low opening, and is more compact than the intake system of a four-wheeled vehicle engine. It has been proposed (see, for example, Patent Document 1).

[Conventional technical problems]
However, the conventional intake device for a two-wheeled vehicle engine described in Patent Document 1 employs a slide valve type throttle valve, and therefore protrudes from the outer periphery of the shaft portion to both sides in the diameter direction of the shaft portion. The butterfly valve type throttle valve in which the intake air is directed to the intake port from between the entire outer peripheral end of the two disk portions and the inner wall surface (bore inner diameter surface) of the cylindrical bore wall of the throttle body. Compared to this, there is a problem that the physique is increasing.

[Defects of prior technology]
Therefore, Japanese Patent Application No. 2003-96724 has already been proposed for the purpose of providing an intake throttle device for an internal combustion engine equipped with a butterfly valve type throttle valve having a very compact intake pipe including the throttle body. No. (filed on March 31, 2003). As shown in FIG. 9, this is because the structure on the downstream side of the throttle valve 102 of the throttle body 101 is a vortex flow into which intake air flows when the throttle valve 102 has a low opening (α °). The generation flow path 103 and the intake air flow path 104 into which intake air flows only when the valve opening of the throttle valve 102 is large are partitioned by a circular tubular partition wall 105 to form a double tube structure. Then, the downstream end of the vortex generating flow path 103 is partitioned by a circumferential partition plate 106, and the internal combustion engine is in a part of the partition plate 106 when the valve opening of the throttle valve 102 is low (α °). An opening 109 is provided on one side of the intake valve 108 for opening and closing the intake port 107 for allowing intake air having a relatively high flow velocity to flow in.

  As a result, when the valve opening of the throttle valve 102 is small and low (α °), a relatively high flow rate flows into the intake port 107 of the internal combustion engine from the opening 109 provided in the circumferential partition plate 106. Atomization of the fuel can be promoted by applying fuel to the fast flow from the injection hole of the injector 111 attached to the cylinder head 110 of the internal combustion engine. Further, when the intake valve 108 is opened, an air-fuel mixture having a relatively high flow velocity is introduced into the combustion chamber of the cylinder from the upper layer side of the intake port 107 of the internal combustion engine through one side of the intake valve 108 to thereby provide a combustion chamber in the cylinder. Can generate a vortex (for example, a longitudinal vortex: a tumble flow).

  In addition, when the amount of intake air is small, the intake air is made to flow along the wall surface of the intake port as a drift converged by the butterfly valve type throttle valve. A throttle valve with a butterfly valve type that allows vortex flow (for example, lateral vortex flow: swirl flow) to be generated in the combustion chamber of the cylinder by arranging the throttle valve in the vicinity of the intake valve so that it is maintained. An intake throttle device for an internal combustion engine has also been proposed (see, for example, Patent Document 2).

  However, in an intake throttle device for an internal combustion engine having a butterfly valve type throttle valve, the downstream end of the throttle body incorporating the throttle valve is directly coupled to the inlet of the intake port formed in the cylinder head of the internal combustion engine. . When a tumble flow is generated in the combustion chamber of the cylinder of the internal combustion engine, the intake air flow is blown out along the upper layer portion of the intake port of the internal combustion engine when the valve opening of the throttle valve is small. It is necessary to form an air outlet for the vortex flow generation flow path, and when a swirl flow is generated in the combustion chamber of the cylinder of the internal combustion engine, when the valve opening of the throttle valve is small, the internal combustion engine It is necessary to form the air outlet of the vortex generating flow path so that the intake air flow blows out along the side portion of the intake port.

Therefore, in the intake throttle device for an internal combustion engine having the butterfly valve type throttle valve as described above, when changing from the swirl flow to the tumble flow, or when changing from the tumble flow to the swirl flow, the intake air of the internal combustion engine Although it is necessary to change the mounting angle of the downstream end of the throttle body with respect to the inlet of the port by at least 90 ° or more, in the case of a two-wheeled vehicle, the positional relationship of the throttle body with respect to the vehicle traveling direction has a structural limitation on the two-wheeled vehicle. In other words, since there is a restriction on the direction in which the accelerator lever integrated with the throttle shaft from the outer wall surface of the throttle body is taken out, it is easy to change the mounting angle of the downstream end of the throttle body with respect to the intake port inlet of the internal combustion engine. A throttle that can generate a desired vortex without a degree of freedom between a throttle body that has a swirl flow channel that generates a swirl flow and a throttle body that has a vortex flow channel that generates a tumble flow There was a problem that it was necessary to prepare each body, resulting in an increase in cost.
Japanese Patent Laid-Open No. 11-166420 (page 1-15, FIGS. 1 to 40) Japanese Patent Laid-Open No. 54-163215 (Pages 1-8, FIGS. 1 and 2)

  It is an object of the present invention to provide intake air locally on the wall surface of an intake port of an internal combustion engine or one side of an intake valve even if there is a restriction on the vehicle structure in the positional relationship of the throttle body (first tubular body) with respect to the vehicle traveling direction. The second tubular body having a laminar flow generation flow path for generating a drift or laminar flow that blows out the flow is made variable in the tube circumferential direction with respect to the first tubular body, so that the specification of the internal combustion engine or It is an object of the present invention to provide an intake throttle device for an internal combustion engine that can be configured with an intake pipe layout that can be arbitrarily selected according to demands without changing the shape of the first tubular body or the second tubular body.

  According to the first aspect of the present invention, the intake pipe through which the intake air flows is provided with a throttle formed with an intake air flow path whose flow path opening area is changed according to the valve opening of the butterfly valve type throttle valve. An outlet duct having a body (first tubular body) and a laminar flow generation flow path for generating a drift or laminar flow that blows intake air locally to a wall surface of an intake port of an internal combustion engine or one side of an intake valve (Second tubular body), and the upstream end of the second tubular body is directly or indirectly coupled to the downstream end of the first tubular body. And, by making the mounting angle of the second tubular body relative to the first tubular body variable in the tube circumferential direction of the first tubular body, the positional relationship of the first tubular body with respect to the vehicle traveling direction has restrictions on the vehicle structure. However, the specifications or requirements of the internal combustion engine (for the purpose of improving the combustion state of the combustion chamber of the internal combustion engine and the exhaust gas purification efficiency, for example, generating a vertical vortex flow (tumble flow) in the combustion chamber of the internal combustion engine, (E.g., generating a lateral vortex flow (swirl flow) in the combustion chamber of the internal combustion engine or promoting atomization of fuel spray injected from the fuel injection valve)) The layout can be configured without changing the shape (design change) of the first tubular body or the second tubular body. As a result, it is possible to provide an intake throttle device for an internal combustion engine having an intake pipe layout with a high degree of design freedom.

  According to the second aspect of the present invention, the laminar flow generation channel ensures the flow velocity and directionality of the intake air flowing into the intake port of the internal combustion engine, and promotes the combustion of the air-fuel mixture in the combustion chamber of the internal combustion engine. It is characterized by being a vortex generating flow path for generating a vortex for generating the vortex. According to the third aspect of the present invention, the laminar flow generation channel has a relatively fast flow velocity characteristic for the intake air flowing in from the intake air channel of the first tubular body, or It is characterized by being an airflow characteristic imparting flow path having airflow characteristics for promoting atomization of fuel spray injected from the injection hole of the fuel injection valve.

  According to the fourth aspect of the present invention, the air outlet for blowing out the intake air toward the intake port of the internal combustion engine is provided at the downstream end of the laminar flow generation flow path. The air outlet is characterized by opening at a position that is eccentric in the direction perpendicular to the direction of the central axis of the second tubular body. According to the fifth aspect of the present invention, the air intake for taking in the intake air from the intake air flow path into the laminar flow generation flow path is provided at the upstream end of the laminar flow generation flow path. And the intake air which flowed in from the air intake port which has an opening cross-sectional area wider than an air blower outlet converges toward the air blower outlet provided only in one place, and has an airflow characteristic with a comparatively quick flow velocity. become. According to the sixth aspect of the present invention, the upstream end of the laminar flow generation channel is provided with an air intake for taking in the intake air from the intake air channel into the laminar flow generation channel. The laminar flow generation channel passes through the laminar flow generation channel by providing the air flow inlet or the laminar flow generation channel so that the cross-sectional area of the flow channel gradually decreases from the middle of the laminar flow generation channel toward the air outlet. The intake air converges from the middle of the air inlet or the laminar flow generation channel toward the air outlet and has an air flow characteristic with a relatively high flow velocity.

  According to the seventh aspect of the present invention, the internal combustion engine is disposed in the vicinity of the flow path of the intake air blown from the air outlet at the downstream end of the laminar flow generation flow path toward the intake port of the internal combustion engine. A fuel injection valve having an injection hole for injecting fuel spray toward the intake port is mounted. As a result, the intake air can be introduced in the vicinity of the injection hole of the fuel injection valve. Therefore, the air assist function for promoting atomization of the fuel spray injected from the injection hole of the fuel injection valve is provided with the injection hole of the fuel injection valve. This can be realized with a simple structure without any change in shape. According to the invention described in claim 8, the first tubular body is provided with the intake air flow path that is opened and closed by the throttle valve. And while opening only in the downstream end of a 1st tubular body, the space connected to a laminar flow production | generation flow path is provided in parallel with the intake air flow path so that the circumference | surroundings of the intake air flow path may be surrounded. The downstream side of the first tubular body has a partial double tube structure by partitioning the intake air flow path and the space with a cylindrical partition.

  According to the ninth aspect of the present invention, the pressure sensor that detects the air pressure introduced from the pressure introduction passage that communicates with the space that is not easily affected by the pressure fluctuation that changes as the valve opening of the throttle valve changes. By providing, the detection accuracy of the air pressure by the pressure sensor can be improved. According to the invention described in claim 10, the auxiliary air passage (the air inlet) of the auxiliary air amount control valve is in a turbulent state downstream of the throttle valve in the flow direction of the intake air. It communicates with a space in a laminar flow state different from the location, that is, a space that is not affected by the disturbance of the intake air in accordance with the size of the throttle valve. Accordingly, it is possible to prevent an irregular flow (turbulent flow) from occurring in the vicinity of the auxiliary air passage (the air introduction port), and thus it is possible to prevent the generation of intake noise.

  According to invention of Claim 11, the 1st tubular body and the 2nd tubular body are each integrally formed with the resin material. And the downstream end of the 1st tubular body and the upstream end of the 2nd tubular body are couple | bonded using heat welding. The second tubular body may be fastened and fixed to the downstream end of the first tubular body using a fastener, and the downstream end of the first tubular body and the upstream end of the second tubular body may be bonded with an adhesive. May be used. According to the invention described in claim 12, the first tubular body and the second tubular body are integrally formed of the resin material. Then, the plurality of engagement claws formed at the upstream end of the second tubular body are fitted into the plurality of engagement holes formed at the downstream end of the first tubular body using elastic deformation, whereby the first tubular body Are connected to the upstream end of the second tubular body.

  The best mode for carrying out the present invention is that the intake pipe conforming to the specifications or requirements of the internal combustion engine, even if there is a restriction on the vehicle structure in the positional relationship of the throttle body (first tubular body) with respect to the vehicle traveling direction. An object of the present invention is to provide an intake throttle device for an internal combustion engine with a high degree of design freedom, in which the layout can be configured without changing the shape of the first tubular body or the second tubular body. A second tubular body having a laminar flow generation flow path that generates a drift or laminar flow that blows out intake air locally to one side of the intake valve is continuously or circumferentially with respect to the first tubular body or Realized by changing the mounting angle in stages.

[Configuration of Example 1]
FIGS. 1 to 4 show Embodiment 1 of the present invention. FIG. 1 is a view showing an intake system of an engine for a two-wheeled vehicle. FIGS. 2 to 4 are main structures of an intake throttle device for an internal combustion engine. FIG.

  The intake throttle device for an internal combustion engine according to the present embodiment is based on the driver's accelerator operation amount. It is built in the middle of an intake pipe through which intake air that flows into the room flows. By changing the amount of intake air drawn into the combustion chamber of the engine, that is, a throttle lever or a throttle handle of a vehicle such as a two-wheeled vehicle It is a device that controls the engine speed or the engine torque by changing the amount of intake air flowing into the combustion chamber of the engine based on the throttle operation amount of the operation component. Note that the throttle operation amount corresponds to a driver's accelerator pedal depression amount (accelerator operation amount) in a four-wheeled vehicle.

  An intake throttle device for an internal combustion engine according to this embodiment includes an accelerator lever 1 mechanically connected to a throttle operating part such as a throttle lever or a throttle handle via a wire cable, and a throttle shaft integrated with the accelerator lever 1. 2, a butterfly valve type throttle valve 3 that rotates integrally with the throttle shaft 2, a throttle body 4 that accommodates the throttle valve 3 in an openable / closable manner, and a downstream end of the throttle body 4. The outlet duct 5, the return spring 6 that urges the throttle valve 3 to return to the fully closed position where the amount of intake air is minimized, and the bypass passage (auxiliary air passage) 9 that bypasses the throttle valve 3. Consists of an auxiliary air amount control valve (not shown) for adjusting the amount of auxiliary air flowing It has been.

  Here, the engine obtains output by heat energy obtained by burning the air-fuel mixture of intake air and fuel in the combustion chamber, and is a cylinder that is airtightly coupled to the downstream end of the intake pipe (intake pipe described later) A head 10 and a cylinder block (not shown) that forms a combustion chamber into which an air-fuel mixture is sucked from an intake port (intake port) 11 having a three-dimensional intake passage shape provided in the cylinder head 10 are provided. Yes. An intake port 11 formed on one side of the cylinder head 10 is an intake valve (intake valve) that is slidably held in a reciprocating direction in a cylindrical valve guide 12 mounted on the cylinder head 10 of the engine. 13, an exhaust port (exhaust port: not shown) is held in a cylindrical valve guide (not shown) mounted on the cylinder head 10 of the engine so as to be slidable in the reciprocating direction. It is opened and closed by an (exhaust valve: not shown).

  The intake valve 13 is configured to open and close the intake port 11 by being separated from or seated on an annular valve seat (seat ring) 14 attached to the intake port 11 of the cylinder head 10 of the engine. Yes. The exhaust valve is configured to open and close the exhaust port by being separated or seated on an annular valve seat (seat ring: not shown) attached to the exhaust port of the cylinder head 10 of the engine. Yes. A piston connected to an engine crankshaft (not shown) via a connecting rod (not shown) is slidably disposed on the inner peripheral surface of the cylinder formed by the cylinder head 10 and the cylinder block. It is installed. Note that a spark plug (not shown) is attached to the cylinder head 10 so that the tip portion is exposed in the combustion chamber.

  In addition, an electronically controlled fuel injection device is mounted on a vehicle such as a two-wheeled vehicle of this embodiment. This is because fuel (for example, gasoline) is pressurized to a constant pressure by an electric fuel pump (not shown), sent to the injector 8 through a fuel filter (not shown), and fuel can be injected at an optimal timing. This is the system. The electronically controlled fuel injection device includes various sensors that detect the operating state of the engine, an engine control unit (hereinafter referred to as ECU: not shown) that integrates them, and the like. Here, the ECU that electronically controls the injector (electromagnetic fuel injection valve) 8 and the auxiliary air amount control valve (idle rotational speed control valve) described later includes functions such as a CPU, a RAM, and a ROM. A microcomputer is provided, and sensor signals from various sensors are A / D converted by an A / D converter and then input to the microcomputer.

  The microcomputer includes an intake pressure signal from a pressure sensor, an intake air temperature signal from an intake air temperature sensor (not shown), an engine temperature signal from an engine wall temperature sensor (not shown), and a fuel temperature sensor (not shown). A sensor signal such as a fuel temperature signal from the engine and a crank angle signal from a crank angle sensor (not shown) are input. The microcomputer detects the engine speed by measuring the pulse interval time of the crank angle signal. Further, the valve opening or rotation angle of the throttle valve 3 may be detected by a throttle position sensor (not shown) attached to the throttle body 4. Further, the valve opening degree of the auxiliary air amount control valve is set so that the measured engine rotational speed substantially matches the target idle rotational speed set corresponding to the engine operating state such as the engine load and the engine warm-up state. The actuator drive current is feedback controlled.

  An intake pipe for sending intake air into the combustion chamber of the engine is an air cleaner case (not shown) that houses and holds an air cleaner (filter element: not shown) that filters the intake air, and is airtight on the downstream side of the air cleaner case. Coupled to the downstream end of the intake duct 15, the outlet duct 5 coupled to the downstream end of the throttle body 4, and the outlet duct 5. The intake pipe 17 and the like are hermetically coupled to the downstream end of the pipe. The intake duct 15 is a connecting hose (or an air cleaner outlet hose or an air intake hose) made of a substantially cylindrical rubber-based elastic body. In the intake duct 15, an intake air flow path 18 for sending intake air filtered by an air cleaner into the throttle body 4 is formed. An insulator 16 is welded and fixed to the outer periphery of the flange-like insulator mounting portion at the outer periphery of the upstream end of the intake pipe 17 by baking or the like.

  The insulator 16 is made of a substantially cylindrical rubber-based elastic body. In this insulator 16, an intake air flow path 19 for sending intake air from the outlet duct 5 to the intake pipe 17 is formed. An intake air flow path 20 for sending intake air from the throttle body 4 to the intake port 11 is formed in the intake pipe 17. In addition, an injector 8 that injects fuel at an optimal timing into the intake port 11 of the engine is attached to the upper layer portion of the intake pipe 17 (particularly, the top wall portion located on the top side in the vertical direction). An injection hole for injecting fuel toward the wall surface (for example, the bottom wall surface) of the intake port 11 of the engine or the back wall surface of the intake valve 13 that opens and closes the intake port 11 is formed at the tip of the injector 8. In the present embodiment, the intake air that is directed to the intake port 11 from the intake throttle device for an internal combustion engine (the air outlet of the laminar flow generation passage of the outlet duct 5) via the intake air passage 20 of the intake pipe 17 is supplied. The injector 8 is installed so that the injection hole is located in the vicinity of the flowing flow path.

  In the intake throttle device for an internal combustion engine of this embodiment, the accelerator lever 1, the throttle shaft 2, the throttle valve 3, the throttle body 4, and the outlet duct 5 are made of resin for the purpose of reducing the weight and cost. In particular, the non-cylindrical shaft-side fitting portion 21 of the throttle shaft 2 and the non-cylindrical valve-side fitting portion 22 of the throttle valve 3 are made of resin so that the shaft-side fitting portion 21 of the throttle shaft 2 and the throttle valve 3 are made of resin. The fitting portion with the valve side fitting portion 22 is fixed by using, for example, heat welding such as laser welding. Further, the fitting portion between the flanged body side fitting part 23 at the downstream end of the throttle body 4 and the flanged duct side fitting part 24 at the upstream end of the outlet duct 5 is used, for example, by heat welding such as laser welding. It is fixed.

  On the outer periphery of the accelerator lever 1, a substantially V-shaped circumferential groove 25 around which an opening side and a closing side wire cable (not shown) interlocked with a throttle operating part such as a throttle lever or a throttle handle operated by a driver is wound. Is provided. Further, on the outer peripheral portion of the accelerator lever 1, an opening side and a closing side attachment groove 26 for attaching one end portion of the opening side and closing side wire cables are provided. A boss-shaped thick portion 27 is provided on the back surface of the accelerator lever 1. The thick portion 27 of the accelerator lever 1 is provided so as to protrude from the periphery to the outer diameter surface side of the bore wall portion of the throttle body 4. The thick portion 27 includes a fully closed stopper portion that contacts the fully closed stopper 29 of the accelerator bracket 28 when the throttle valve 3 is fully closed, and a fully open portion that contacts the fully open stopper of the accelerator bracket 28 when the throttle valve 3 is fully opened. The stopper part is integrally formed by resin molding.

  The throttle shaft 2 is, for example, a resin material such as a thermoplastic resin (heat-resistant resin: for example, polybutylene terephthalate: PBT, or polyphenylene sulfide: PPS, or polyamide resin: PA, or polypropylene: PP, or polyetherimide: PEI). Insert-molding a split-type metal member made of a metal material (for example, stainless steel such as SUS304) for reinforcing the resin-molded portion such as the shaft-side fitting portion 21 into the shaft-side fitting portion 21 integrally molded by the resin Shaft. The shaft-side fitting portion 21 is a non-cylindrical valve fixing portion (resin shaft) that fixes the valve-side fitting portion 22 of the throttle valve 3 using a heat welding method such as laser welding. On the outer peripheral surface of the shaft side fitting portion 21, two flat surfaces (two surface width portions) are formed for increasing the welding strength at the time of laser welding. The outer peripheral surface of the shaft-side fitting portion 21 excluding two flat surfaces (two-surface width portions) is an arc-shaped curvature surface centered on the central axis (axial center / rotation center) of the throttle shaft 2. Yes. Further, after fitting the valve side fitting part 22 of the throttle valve 3 on the outer periphery of the shaft side fitting part 21 of the throttle shaft 2, the valve side fitting of the throttle valve 3 is fitted to the shaft side fitting part 21 of the throttle shaft 2. The joint portion 22 may be fastened and fixed using a screw such as a fixing bolt or a fastening screw.

  The split-type metal member includes a central shaft bar-shaped metal shaft 31 arranged in the whole axial direction from one end surface to the other end surface of the throttle shaft 2 and a cylindrical gap partially spaced on the outer periphery of the metal shaft 31. The cylindrical metal pipe (not shown) etc. which were fitted and arrange | positioned on the same axial center as the metal shaft 31 are comprised. A portion of the metal shaft 31 of the throttle shaft 2 that is fitted to the shaft-side fitting portion 21 is a small-diameter portion having a cylindrical shape. The metal shaft 31 is exposed at the outer peripheral surface of the throttle shaft 2 at the other end in the axial direction from the shaft-side fitting portion 21, and the exposed portion is the second shaft sliding hole of the throttle body 4. It is a cylindrical large-diameter portion that constitutes a second bearing sliding portion that is rotatably supported on an inner peripheral surface (not shown).

  Further, the metal pipe of the throttle shaft 2 is fitted to the outer periphery of one end portion in the axial direction of the shaft side fitting portion 21, and the fitting portion is exposed to the outer circumferential surface of the throttle shaft 2, and the exposed portion is A first bearing sliding portion is rotatably supported on an inner peripheral surface of a first shaft sliding hole (not shown) of the throttle body 4. Here, the throttle shaft 2 of the present embodiment has an eccentricity in which the rotation center axis of the metal shaft 31 is decentered by a predetermined distance on the lower side in the figure in the radial direction with respect to the center axis of the intake air passage 41 of the throttle body 4. Placed in position. An accelerator lever 1 mechanically connected to a throttle operating part such as a throttle lever or a throttle handle via a wire cable is identical to the shaft-side fitting portion 21 at one end of the throttle shaft 2 in the rotation center axis direction. The resin material is integrally formed.

  The throttle valve 3 is, for example, a resin material such as a thermoplastic resin (heat-resistant resin: for example, polybutylene terephthalate: PBT, or polyphenylene sulfide: PPS, or polyamide resin: PA, or polypropylene: PP, or polyetherimide: PEI). The resin molded product integrally formed by the above-described method is accommodated in the throttle body 4 so as to be freely opened and closed. The throttle valve 3 is a butterfly having a rotation center axis in a direction substantially perpendicular to a center axis direction (an axis direction of an average flow of intake air) of a bore wall portion (bore inner pipe described later) of the throttle body 4. The valve-type rotary valve (butterfly valve) changes the rotation angle (valve opening) within the rotationally operable range from the fully closed position that minimizes the intake air amount to the fully open position that maximizes the intake air amount. As a result, the amount of intake air taken into the combustion chamber of the engine is controlled. The throttle valve 3 has a valve opening (rotation angle) according to a throttle operation amount of a throttle operation part such as a throttle lever or a throttle handle of a vehicle such as a two-wheeled vehicle for adjusting the amount of intake air into the combustion chamber of the engine. Is changed.

  The throttle valve 3 is connected to a non-cylindrical valve side fitting portion 22 that is fitted and held and fixed to the outer periphery of the shaft side fitting portion 21 of the throttle shaft 2, and the valve side fitting portion 22. A disc-shaped portion (valve main body) 32 extended in the tangential direction of the valve-side fitting portion 22 is integrally formed. The valve side fitting portion 22 of the throttle valve 3 is fixed by using heat welding such as laser welding after being fitted on the outer periphery of the shaft side fitting portion 21 of the throttle shaft 2. The valve-side fitting portion 22 is press-fitted and fixed to the outer periphery of the shaft-side fitting portion 21 of the throttle shaft 2 at the center portion or at least one end portion of the fitting portion of the throttle shaft 2 with the shaft-side fitting portion 21 ( It has a throttle part (press-fit part) to be fitted.

  An oval through hole (fitting hole) 33 penetrating in the axial direction is formed in the valve side fitting portion 22. Further, in the inner peripheral surface of the valve side fitting portion 22, the portion corresponding to the two flat surfaces (two surface width portions) formed on the outer peripheral surface of the shaft side fitting portion 21 of the throttle shaft 2 is Two flat surfaces (two-surface width portions) are formed. This can prevent relative rotational movement between the shaft-side fitting portion 21 of the throttle shaft 2 and the valve-side fitting portion 22 of the throttle valve 3. The inner peripheral surface and the outer peripheral surface of the valve-side fitting portion 22 excluding two flat surfaces (two-surface width portions) are arcuate curved surfaces centering on the axis of the valve-side fitting portion 22. . A plurality of reinforcements are provided on one or both end surfaces of the disc-like portion 32 of the throttle valve 3 so as to connect the outer peripheral portion of the valve-side fitting portion 22 and the vicinity of the outer-diameter side end portion of the disc-like portion 32. The ribs 34 are integrally formed. Further, at the outer diameter side end portion of the disc-shaped portion 32 of the throttle valve 3, as shown in FIG. 4, a substantially arc shape for making the flow rate characteristic of the intake air non-linear with respect to the valve opening degree of the throttle valve 3 is shown. The convex portions (ribs) 35 and 36 are integrally formed.

  The throttle body 4 corresponds to the first tubular body of the intake pipe of the present invention. For example, a resin material such as a thermoplastic resin (heat-resistant resin: for example, polybutylene terephthalate: PBT, or polyphenylene sulfide: PPS, or A resin molded product (resin-molded) that is integrally molded (resinized) with polyamide resin: PA, polypropylene: PP, or polyetherimide: PEI, and the like, and a device that rotatably accommodates and holds the throttle shaft 2 and the throttle valve 3 (Housing). An intake air passage 41 for sending intake air into the combustion chamber of the engine is formed in the cylindrical bore wall of the throttle body 4. As shown in FIG. 1, the intake air passage 41 is an intake passage having a circular cross section through which the intake air flows in the direction of the central axis, and from the air cleaner through the intake air passage 18 of the intake duct 15. It has an air inlet part (upstream side opening part) for sucking in intake air and an air outlet part (downstream side opening part) for allowing intake air to flow into the intake port 11 of the engine via the outlet duct 5. .

  Here, on the bracket mounting base 42 of the throttle body 4, for example, an accelerator bracket 28 integrally formed in a predetermined shape by press forming a metal plate such as a cold rolled steel plate (SPCC) is fastened. It is tightened and fixed using a screw 43 such as a screw. The accelerator bracket 28 is integrally provided with a claw-like portion 44 for holding the valve opening side and valve closing side wire cables movably in the reciprocating direction. The accelerator bracket 28 has a flat-plate full-close stopper 29 with which a full-close stopper portion (not shown) of the accelerator lever 1 abuts directly or indirectly when the throttle valve 3 is fully closed, and the throttle valve 3. A flat open stopper (not shown) with which the fully open stopper portion (not shown) of the accelerator lever 1 abuts directly or indirectly when the valve is fully opened is integrally provided.

  The bore wall portion of the throttle body 4 according to the present embodiment is composed of only a substantially cylindrical bore inner pipe (or bore outer pipe) 45 on the upstream side in the intake air flow direction from the rotation center axis of the throttle valve 3. . At the upstream end of the bore inner pipe (or bore outer pipe) 45, a cylindrical intake duct mounting portion for fastening and fixing the downstream end of the intake duct 15 using a clamp, a mounting bracket or a fastening tool such as a mounting band. 46 is integrally formed. The inner periphery of the downstream end of the intake duct 15 is fitted into the outer periphery of the intake duct mounting portion 46 and is airtightly coupled. Further, the bore wall portion of the throttle body 4 of the present embodiment is such that the downstream side in the flow direction of the intake air with respect to the rotation center axis of the throttle valve 3 is a bore-shaped tube with a substantially truncated cone shape (the inner diameter side forming the bore inner diameter Formed in a partial double tube structure in which a substantially cylindrical bore outer pipe (outer diameter side cylindrical part forming the outer wall of the bore wall of the throttle body 4) 52 is disposed on the outer diameter side of the cylindrical part 51 in the radial direction. Has been.

  Further, the intake air passage 41 communicating with the combustion chamber of the engine is formed in the bore inner pipe 51, and the shaft side fitting portion 21 of the throttle shaft 2 is formed in the intake air passage 41. The entire throttle valve 3 is rotatably incorporated. Here, the bore inner tube 51 is formed in a substantially truncated cone shape so as to be inclined from the inner peripheral portion of the bore outer tube 52 to the left in the figure at a predetermined inclination angle. In addition, a conical surface 53 that gradually decreases in diameter toward the downstream side in the flow direction of the intake air is formed on the bore inner diameter surface of the bore inner pipe 51. This conical surface 53 can restrict further rotation of the throttle valve 3 in the fully closed direction when the outer diameter side end of the disc-shaped portion of the throttle valve 3 is mechanically touched (directly contacted). A simple valve locking portion. At the downstream end of the bore outer tube 52, the flanged body side fitting part 23 for joining the flanged duct side fitting part 24 at the upstream end of the outlet duct 5 by using thermal welding such as laser welding, for example. Are integrally formed. The flange-like body-side fitting portion 23 includes a body-side cylindrical portion 23a fitted on the outer periphery of the flange-like duct-side fitting portion 24, and a radial direction from the outer peripheral surface of the downstream end of the body-side cylindrical portion 23a. It consists of an annular body-side annular portion (a flange-like flange portion) 23b that extends outward.

  The throttle body 4 has a cylindrical space 54 that communicates with the intake air passage 41 in parallel with the combustion chamber of the engine between the bore inner pipe 51 and the bore outer pipe 52. The bore inner tube 51 constitutes a cylindrical partition that partitions the cylindrical space 54 and the intake air flow path 41. The cylindrical space 54 is provided in parallel to the intake air flow path 41 so as to surround the intake air flow path 41, and is a substantially annular recess that opens only at the downstream end of the bore wall portion of the throttle body 4. Is configured. Further, the upstream end of the cylindrical space 54 is partitioned by a partition wall 55 over the entire circumference in the circumferential direction, so that a portion of the bore wall portion of the throttle body 4 downstream from the rotation center axis of the throttle valve 3 is partially double-structured. It is said.

  The outlet duct 5 corresponds to the second tubular body of the intake pipe of the present invention, and is, for example, a resin material such as a thermoplastic resin (heat-resistant resin: for example, polybutylene terephthalate: PBT, or polyphenylene sulfide: PPS, or Polyamide resin: PA, or polypropylene: PP, or polyetherimide: PEI, etc., which is a resin molded product (resinized), which is formed on the outer pipe 52 of the throttle body 4 with respect to the throttle body 4. This is a housing whose mounting angle is variable in the pipe circumferential direction. The outlet duct 5 has an intake air passage 61 through which intake air flows only when the valve opening or rotation angle of the throttle valve 3 is large and a low opening when the valve opening or rotation angle of the throttle valve 3 is small. A double-pipe structure is formed by partitioning into a laminar flow generation flow path 62 into which intake air flows by a substantially circular partition wall (hereinafter referred to as a bore inner pipe) 63. That is, the outlet duct 5 is formed in a double tube structure in which a circular bore outer tube 64 is arranged on the radially outer diameter side of a substantially circular tube inner tube 63 with a predetermined annular gap. Yes. An intake air passage 41 formed in the bore inner pipe 51 of the throttle body 4 is provided between the downstream end of the bore inner pipe 51 of the throttle body 4 and the upstream end of the bore inner pipe 63 of the outlet duct 5. The air inlet portion of the laminar flow generation flow path 62 formed between the wall surface side portion (annular air outlet portion) at the downstream end, the outer periphery of the bore inner tube 63 of the outlet duct 5 and the inner periphery of the bore outer tube 64 ( A cylindrical communication path 65 communicating with the substantially annular air intake 73) is formed.

  The laminar flow generation channel 62 ensures the flow velocity and directionality of the intake air flowing into the intake port 11 of the engine even when the valve opening (rotation angle) of the throttle valve 3 is small and low, for example. For the purpose of generating a vertical vortex (tumble flow) for promoting combustion of the air-fuel mixture in the combustion chamber of the engine, the flow velocity is relatively high and the wall surface of the intake port 11 (for example, the ceiling side wall surface) or An eddy current generating flow path for generating a drift or laminar flow that blows the intake air locally to one side of the intake valve 13 is configured. In addition, a substantially annular air intake 73 for taking in intake air from the intake air passage 41 of the throttle body 4 is formed at the upstream end of the laminar flow generation passage 62. The air inlet 73 has an opening cross-sectional area wider than that of the air outlet 74. Further, the air intake 73 has a purpose of reducing bending pressure loss when intake air flows into the laminar flow generation passage 62 from the intake air passage 41 of the throttle body 4 via the communication passage 65. A chamfered portion having a tapered or R-shaped chamfer is provided. The air intake 73 communicates with the air outlet of the cylindrical space 54 of the throttle body 4 and also communicates with the air outlet of the intake air passage 41 of the throttle body 4 through the communication passage 65. Yes. The flow path diameter of the laminar flow generation flow path 62 and the opening cross-sectional area of the air intake or air outlet may be arbitrarily changed according to engine specifications (e.g., displacement) or the like.

  Also, a substantially arc-shaped air outlet 74 is formed at the downstream end of the laminar flow generation channel 62 to blow intake air toward the wall surface (for example, the ceiling side wall surface) of the intake port 11 or one side of the intake valve 13. Has been. Further, the downstream end of the laminar flow generation channel 62 of the present embodiment is partitioned by a substantially annular plate-like partition plate 66, which is a part of the partition plate 66, that is, in the direction of the central axis of the outlet duct 5. The air outlet 74 is provided at only one position at a position that is eccentric to the upper layer side in the vertical direction (the upper side in FIG. 1, FIG. 2A, FIG. 4 and FIG. 5A, FIG. 5C). It is open. In the present embodiment, the dimension in the axial direction of the flow of the intake air is longer on the upper side in the figure of the bore inner pipe 63 than on the lower side in the figure of the bore inner pipe 63. The upper layer side (the upper side in the figure) is inclined with respect to the lower layer side (the lower side in the figure) of the partition plate 66 so as to be positioned downstream in the flow direction of the intake air. That is, the laminar flow generation channel 62 is provided such that the cross-sectional area of the channel gradually decreases from the middle of the laminar flow generation channel 62 toward the air outlet 74.

  Here, at the downstream end of the bore outer pipe 64 of the outlet duct 5, there is a cylindrical insulator mounting portion 67 for fastening and fixing the upstream end of the insulator 16 using a clamp, a mounting bracket, a mounting band or the like. It is integrally formed. The inner periphery of the upstream end of the insulator 16 is fitted to the outer periphery of the insulator mounting portion 67 and is airtightly coupled. Further, at the upstream end of the bore outer pipe 64 of the outlet duct 5, for example, laser welding or the like is welded to the flange-like body side fitting portion 23 at the downstream end of the bore wall portion (bore inner pipe) 51 of the throttle body 4. The hook-shaped duct side fitting portion 24 to be coupled with each other is integrally formed. The flanged duct side fitting portion 24 includes a duct side cylindrical portion 24a fitted to the inner periphery of the body side cylindrical portion 23a of the flanged body side fitting portion 23, and an outer periphery of the duct side cylindrical portion 24a. It is composed of a duct-side annular portion (a flange-like flange portion) 24b that extends outward in the radial direction from the surface. The duct-side annular portion 24b is disposed so as to face the body-side annular portion 23b and is in close contact with the end surface of the body-side annular portion 23b. Note that an O-ring 68 serving as a sealing material is provided on the outer periphery of the duct-side cylindrical portion 24a as a seal material for hermetically sealing (sealing) between the flange-like body-side fitting portion 23 and the flange-like duct-side fitting portion 24. Is formed with an O-ring groove 69.

  Here, a pressure sensor (none of which is shown) is attached to the outer wall surface at the downstream end of the bore wall portion of the throttle body 4 of this embodiment, that is, the outer wall surface of the bore outer tube 52 via a rubber hose. . This pressure sensor detects the air pressure in the cylindrical space 54 introduced from the pressure introduction passage (pressure sensing port) 7 formed in the pressure introduction pipe 71 in which one end of the rubber hose is fitted in an airtight manner. It is a sensor. The pressure introduction pipe 71 is provided so as to extend upward in the figure from the outer wall surface on the upper end side (ceiling side) of the bore outer pipe 52 in the figure, and the pressure introduction passage 7 is, for example, the ceiling of the cylindrical space 54. The pressure inlet is open on the side wall surface. The pressure sensor is a semiconductor pressure sensor composed of a piezoresistive element that converts the air pressure in the cylindrical space 54 of the throttle body 4 introduced through the pressure introduction passage 7 into an electrical signal and outputs the electrical signal, and outputs from the semiconductor pressure sensor. This is an intake pipe pressure (intake pressure) sensor that has a pressure detection unit such as an amplifier circuit that amplifies the electric signal to be detected, and detects a pressure change in the intake pipe by replacing it with a voltage change.

  In addition, a valve housing (not shown) of an auxiliary air amount control valve is attached to the downstream end of the bore wall portion of the throttle body 4 of this embodiment, that is, the outer wall surface of the bore outer tube 52 via a communication tube. Yes. This auxiliary air amount control valve is an auxiliary flow that flows through a bypass passage (auxiliary air passage) 9 formed in a valve housing, a connecting pipe and an auxiliary air introduction pipe 72 in which one end of the connecting pipe is fitted in an airtight manner. Valve (valve element) that adjusts the amount of air, actuator (valve element drive means) such as a stepping motor that drives the valve in the valve opening direction, and valve element energization such as a spring that urges the valve in the valve closing direction Means (both not shown). Here, the valve housing of the auxiliary air amount control valve of the present embodiment is provided with a frame-like seat wall (not shown) in which the valve seats with a minute gap. A hole (not shown) is formed. That is, the auxiliary air amount control valve of the present embodiment is an idle rotation speed of a type in which a slight amount of air leaks not only when the throttle valve 3 is fully closed, that is, during idle operation, but over the entire operation region of the engine. It is a control valve.

  The auxiliary air introduction pipe 72 is provided so as to extend downward in the figure from the outer wall surface on the lower end side (bottom side) of the bore outer pipe 52 in the figure. Further, the bypass flow path 9 bypasses the throttle valve 3 from an air inlet formed in an intake pipe (for example, an intake duct 15) upstream of the throttle valve 3, and forms a cylindrical space 54 of the throttle body 4. It is an intake air flow path leading to an air outlet formed on the wall surface. Further, the bypass channel 9 has an air outlet (air inlet) opened at the bottom wall surface of the cylindrical space 54, for example. Further, the flow path diameter of the bypass flow path 9 may be arbitrarily changed according to engine specifications (for example, the displacement) or the like. The diameter of the bypass flow path 9 in this embodiment is larger than the diameter of the pressure introduction path 7.

  The auxiliary air amount control valve changes the flow passage area of the bypass flow passage 9 and variably controls the intake air amount supplied to the combustion chamber of the engine via the bypass flow passage 9, thereby An idle speed control valve (ISCV) that controls the idle rotational speed according to the engine load and the warm-up state of the engine is configured during idle operation, that is, when the throttle valve 3 is fully closed. For example, even when the engine load increases, the auxiliary air amount control valve is supplied into the combustion chamber of the engine by lifting the valve according to the drive current to the actuator and increasing the flow passage area of the bypass flow passage 9. The amount of intake air to be increased can be increased, and engine stall can be prevented.

[Assembly method of Example 1]
Next, a method for assembling the throttle body 4 and the outlet duct 5 according to the present embodiment will be briefly described with reference to FIGS.

  Here, the mounting angle of the throttle body 4 is required to mechanically connect a throttle operating part such as a throttle lever or a throttle handle and the accelerator lever 1 integrated at one end of the throttle shaft 2 via a wire cable. Since the pressure sensor and the pressure introducing pipe 71 of the throttle body 4 need to be connected via a rubber hose, the mounting angle of the throttle body 4 with respect to the traveling direction of the vehicle such as a two-wheeled vehicle is It is predetermined for each vehicle. However, even for the same vehicle type, there is a demand to have a plurality of variations by variously changing engine specifications (e.g., displacement, etc.) or requirements. For example, in an engine, various eddy currents are created in order to promote rapid and good combustion of the air-fuel mixture in the combustion chamber. This is a tumble flow in which the air-fuel mixture flowing from the intake port 11 into the combustion chamber causes a vortex flow in the vertical direction, and the swirl flow in which the air-fuel mixture flowing from the intake port 11 into the combustion chamber causes a vortex flow in the lateral direction. is there. Further, it is conceivable to improve the combustion performance in the combustion chamber by accelerating atomization of the fuel spray by applying an intake air flow having a relatively high flow rate to the fuel spray injected from the injection hole of the injector 8. .

  Therefore, in this embodiment, the throttle body 4 and the outlet duct 5 are divided into two parts, and the mounting angle of the outlet duct 5 with respect to the throttle body 4 is determined according to the engine specifications (for example, the displacement) or the demand. The bore wall of the four bore walls is variable in the pipe circumferential direction of the outer pipe 52. In this embodiment, as indicated by arrows in FIG. 1, the intake air blown from the air outlet 74 of the laminar flow generation passage 62 of the outlet duct 5 toward the combustion chamber is used as the intake air flow of the intake pipe 17. It is possible to generate a tumble flow in the combustion chamber that flows along the top wall side of the passage 20 and the top wall side of the intake port 11 of the cylinder head 10 and has an effect of promoting mixing and mixing by the rising of the piston. A method of joining the flange-shaped body side fitting portion 23 at the downstream end of the throttle body 4 and the flange-shaped duct side fitting portion 24 at the upstream end of the outlet duct 5 at a mounting angle by using thermal welding such as laser welding. Will be explained.

  As shown in FIG. 4, on the inner periphery of the body side cylindrical portion 23a of the saddle-like body side fitting portion 23 at the downstream end of the throttle body 4 incorporating a valve assembly such as the throttle shaft 2 and the throttle valve 3, an O The duct-side cylindrical portion 24a of the flange-shaped duct-side fitting portion 24 at the upstream end of the outlet duct 5 in which the O-ring 68 is mounted in the ring groove 69 is fitted. At this time, the air outlet 74 of the laminar flow generation channel 62 provided in the outlet duct 5 is located on the upper layer side of the outlet duct 5, that is, on the protruding side of the pressure introduction pipe 71 of the throttle body 4. The flange-like body side fitting portion 23 at the downstream end and the flange-like duct side fitting portion 24 at the upstream end of the outlet duct 5 are fitted together. Further, the downstream annular end surface of the body side annular portion 23b of the throttle body 4 and the upstream annular end surface of the duct side annular portion 24b of the outlet duct 5 are brought into contact with each other.

  Then, the throttle body 4 and the outlet duct 5 in such a fitted state are assembled to a jig of a laser welding apparatus (not shown). The jig is configured to be movable in the circumferential direction, for example, and a laser device is installed on the side of the jig. The laser device collects the laser beam output from the laser oscillator with a lens or the like and irradiates the downstream annular end surface of the duct-side annular portion 24 b of the outlet duct 5. As the laser oscillator of the laser device, a semiconductor laser oscillator having a laser output of about 20 W to 30 W is used. Further, as the laser oscillator, other laser oscillators such as a pulse YAG (yttrium, aluminum, garnet) laser and a CO2 laser may be used. Further, the moving speed of the jig is set to about 10 mm / sec.

  While irradiating the downstream annular end surface of the duct-side annular portion 24b of the outlet duct 5 with laser light from the laser oscillator of the laser apparatus, the jig is moved in the pipe circumferential direction of the outlet duct 5, and the duct-side annular portion Laser irradiation is performed by reciprocating in the radial direction of 24b. At this time, the laser light enters the duct-side annular portion 24b of the outlet duct 5, passes through the portion, reaches the downstream annular end surface of the body-side annular portion 23b of the throttle body 4, and is absorbed. . This laser irradiation melts the downstream annular end surface of the body-side annular portion 23b, and the heat causes the upstream annular end surface of the duct-side annular portion 24b to melt, and the downstream side of the body-side annular portion 23b. The annular end surface and the upstream annular end surface of the duct-side annular portion 24b are heat-welded. Note that the body-side cylindrical portion 23a and the duct-side cylindrical portion 24a may be joined using thermal welding such as laser welding.

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

  When the driver operates a throttle operating part such as a throttle lever or a throttle handle of a vehicle such as a two-wheeled vehicle, the accelerator lever 1 mechanically connected to the throttle operating part via a wire cable causes the urging force of the return spring 6 to move. Against this, it rotates by a predetermined rotation angle corresponding to the throttle operation amount. As a result, the throttle shaft 2 that rotates integrally with the accelerator lever 1 rotates by a predetermined rotation angle, and the throttle valve 3 rotates by a predetermined valve opening (rotation angle) in the intake air passage 41 of the throttle body 4. To do. Therefore, since the intake air flow path 41 of the throttle body 4 is opened by the valve opening, the engine speed is changed to a speed corresponding to the throttle operation amount.

  On the other hand, the fuel pumped up from the fuel tank is supplied into the injector 8 through a fuel pump, a fuel filter, and a fuel pipe. When the injector 8 receives an injection signal from the ECU, the injector 8 is injected into the intake air flow path 20 of the intake pipe 17 and the intake port 11 of the cylinder head 10 from the injection hole at the tip of the injector 8 with good timing. In this embodiment, the fuel injection timing and the fuel injection amount (fuel injection period) are controlled so as to overlap with the intake stroke of the engine or to end the fuel spray injection before the intake stroke of the engine. The fuel injection timing (injection timing) and the fuel injection amount (fuel) are injected from the injection hole of the injector 8 toward the wall surface of the engine intake port 11 (for example, the bottom wall surface) or the back wall surface of the intake valve 13 of the engine. The injection period is determined by the ECU. For example, the intake air pressure of the engine is detected by a pressure sensor to indirectly calculate the intake air amount, and the basic injection period is calculated from the calculated intake air amount and the measured engine rotation speed. The command injection period is determined by correcting the sensor signal. The basic injection period may be directly calculated from the intake pipe pressure and the engine speed.

  In the intake stroke of the engine, when the intake valve 13 is open and the exhaust valve is closed, if the piston moves downward from the top dead center toward the bottom dead center, a negative pressure is generated in the combustion chamber, and the air-fuel mixture flows into the combustion chamber. Inhaled. At this time, the intake air filtered by the air cleaner flows into the intake air passage 41 of the throttle body 4 via the intake air passage 18 of the intake duct 15. Then, according to the valve opening of the throttle valve 3, the intake air flowing from the air outlet portion of the intake air passage 41 of the throttle body 4 into the intake air passage 61 of the outlet duct 5, the communication passage 65, the air intake The air is divided into intake air flowing into the laminar flow generation flow path 62 via the inlet 73. The intake air flowing into the intake air passage 61 is sucked into the combustion chamber via the intake air passage 19 of the insulator 16, the intake air passage 20 of the intake pipe 17, and the intake port 11 of the cylinder head 10. In this embodiment, the amount of intake air taken into the combustion chamber of the engine is indirectly measured by calculating the intake pipe pressure detected by the pressure sensor and the measured engine rotation speed with the ECU. Yes. That is, an intake pipe pressure method (speed density method) is adopted as the intake air amount detection device.

  On the other hand, the intake air that has flowed into the laminar flow generation flow path 62 is more downstream in the flow direction of the intake air on the upper layer side (upper side in the drawing) than on the lower layer side (lower side in the drawing) of the partition plate 66. In other words, the laminar flow generation channel 62 is provided so that the cross-sectional area of the channel gradually decreases from the middle of the laminar flow generation channel 62 toward the air outlet 74. ing. As a result, the intake air that has flowed into the lower layer side of the laminar flow generation channel 62 easily flows into the air outlet 74 provided on the upper layer side without resistance. The intake air that has flowed into the laminar flow generation channel 62 converges from the middle of the laminar flow generation channel 62 toward the air blowout port 74 and is blown out from the air blowout port 74 at a relatively high flow rate. It becomes a fast flow of.

  Thus, in the intake air flow path 20 of the intake pipe 17 and the intake port 11 of the cylinder head 10, the intake air flow path 20 and the intake port 11 are arranged along the upper layer portion (ceiling side wall surface) of the intake air flow path 20 and the intake port of the engine. Thus, it is possible to create an air flow having a relatively high flow velocity toward one of the 11 wall surfaces (for example, the ceiling side wall surface) or one side of the intake valve 13. Further, the fuel spray injected from the injection hole of the injector 8 is applied to an air flow having a relatively high flow velocity toward one side of the intake valve 13. Thereby, when the intake valve 13 is opened, the flow of the intake air flowing into the intake air flow path 20 of the intake pipe 17 and the intake port 11 of the cylinder head 10 from the air outlet 74 of the laminar flow generation flow path 62 is used. Thus, the atomization of the fuel spray injected from the injection hole of the injector 8 can be promoted. Then, when the intake valve 13 is opened, the air-fuel mixture having a relatively high flow velocity enters the combustion chamber via the intake air flow path 20 and the upper layer portion (ceiling side wall surface) of the intake port 11 and one side of the intake valve 13. Therefore, a vertical vortex flow (tumble flow) can be generated. Therefore, eddy currents for accelerating the combustion of the air-fuel mixture can be actively generated in the combustion chamber of the engine, so that it can be burned at a thin air-fuel ratio (lean combustion) that is difficult to burn normally, and the fuel efficiency can be reduced without degrading the engine performance. Can be improved.

  In the compression stroke in which the intake valve 13 is closed and the piston rises, the atomized fuel is vaporized in the air-fuel mixture, and is compressed in the combustion chamber while being mixed with air and becoming a flammable gas. When the piston reaches top dead center and the temperature and pressure are both high, when the spark plug is used to ignite the spark, the air-fuel mixture burns rapidly, and the piston is pushed down by the combustion gas with increased pressure. The crankshaft is turned (explosion stroke). When the piston reaches the bottom dead center, the exhaust valve is opened, and the combustion gas is ejected from the exhaust port, and the piston is raised to expel the combustion gas remaining in the combustion chamber (exhaust stroke). In the present embodiment, the above four strokes of intake, compression, explosion, and exhaust are performed while the crankshaft makes two revolutions (720 ° CA).

  On the other hand, when the driver returns the throttle operation part such as the throttle lever or the throttle handle, the accelerator lever 1, the throttle valve 3 and the throttle shaft 2 are returned to the fully closed direction by the urging force of the return spring 6, and the throttle body 4 Is closed by the throttle valve 3. Even when the throttle valve 3 is fully closed, the intake air flows into the combustion chamber of the engine via the bypass flow path 9 that bypasses the throttle valve 3. It becomes idle rotation speed.

[Effect of Example 1]
As described above, in the intake throttle device for the internal combustion engine of the present embodiment, the flow passage opening area of the throttle body described in Comparative Example 1 shown in FIG. 9 is changed according to the valve opening of the throttle valve 3. Are divided into a throttle body 4 having an intake air flow path 41 and an outlet duct 5 having a laminar flow generation flow path 62 for generating a tumble flow in the combustion chamber of the engine. Here, the throttle body 4 is a main body component that constitutes a substantially tubular first tubular body that accommodates the throttle valve 3 so as to be freely opened and closed. Further, the outlet duct 5 has an air inlet 73 having an annular opening cross section wider than the air outlet 74, and can blow out an air flow having a relatively higher flow velocity than the one air outlet 74. It is an accessory part which comprises a 2nd substantially tubular body.

  And, by making the mounting angle of the outlet duct 5 with respect to the throttle body 4 continuously variable in the pipe circumferential direction of the throttle body 4, there is a restriction in the vehicle structure in the positional relationship of the throttle body 4 with respect to the vehicle traveling direction. In order to improve the engine specifications (for example, the displacement, etc.) or requirements (the combustion state in the engine combustion chamber and the exhaust gas purification efficiency, for example, a tumble flow or a swirl flow is generated in the engine combustion chamber, or an injector (E.g., promoting atomization of fuel spray injected from the 8 injection holes), the layout of the intake pipe that can be arbitrarily selected in accordance with the change (design change) of the throttle body 4 or the outlet duct 5 Can be configured without. Thus, the target position of the intake port 11 that three-dimensionally bends the air flow having a relatively high flow velocity without changing the mounting position of the throttle body 4 in the vehicle traveling direction (in this example, the ceiling side wall surface of the intake port 11). ), It is possible to generate a desired vortex flow in the combustion chamber. Therefore, it is possible to provide an intake throttle device for an internal combustion engine having an intake pipe layout with a high degree of design freedom.

  In the intake throttle device for the internal combustion engine of this embodiment, the air is blown from the air outlet 74 of the laminar flow generation passage 62 toward the ceiling side wall of the intake port 11 of the engine and one side of the intake valve 13. In addition, an injector 8 having an injection hole for injecting fuel spray toward the intake port 11 of the engine is provided in the upper layer portion (injector mounting portion) of the intake pipe 17 in the vicinity of the intake air flow path having a high flow velocity. Thereby, since the intake air can be introduced in the vicinity of the injection hole of the injector 8, the air assist function for promoting atomization of the fuel spray injected from the injector 8 is accompanied by a change in the shape of the injection hole of the injector 8. And can be realized with a simple structure.

  Further, in the intake throttle device for the internal combustion engine of the present embodiment, the cross-sectional shape of the throttle body 4 constituting the intake pipe for sending the intake air into the combustion chamber of the engine is set to the intake air rather than the rotation center axis of the throttle valve 3. The downstream side in the flow direction has a partial double pipe structure in which the bore outer pipe 52 is arranged on the radially outer diameter side of the bore inner pipe 51. A cylindrical space that communicates in parallel with the intake air passage 41 that accommodates the throttle valve 3 in an openable / closable manner between the bore inner tube 51 and the bore outer tube 52 of the throttle body 4 in parallel with the combustion chamber of the engine. 54 is formed. A pressure introducing pipe 71 is integrally formed so as to extend upward from the outer wall surface on the upper end side (ceiling side) of the bore outer pipe 52 of the throttle body 4 in the figure. Further, an auxiliary air introduction pipe 72 is integrally formed so as to extend downward from the outer wall surface on the lower end side (bottom side) of the bore outer pipe 52 in the figure.

  In this embodiment, the air introduction port of the bypass passage 9 is opened at the wall surface (for example, the bottom side wall surface) of the lower end portion of the cylindrical space 54, and the farthest place from the air introduction port of the bypass passage 9, That is, since the pressure introduction port of the pressure introduction passage 7 is opened at the wall surface (for example, the ceiling side wall surface) of the upper end portion of the cylindrical space 54 shown in the figure, even if the valve opening of the throttle valve 3 is large, the throttle valve 3 is less affected by the turbulence of the downstream airflow, and even when the throttle valve 3 is fully closed (idle operation), the turbulence of the airflow downstream of the air outlet portion of the bypass flow path 9 is affected. A pressure introduction port of the pressure introduction passage 7 is formed at a location that is difficult to receive. As a result, the cylindrical space 54 is not affected by the turbulence of the air flow that occurs according to the magnitude of the valve opening of the throttle valve 3 and the pressure fluctuation is as small as possible, that is, with the change of the valve opening of the throttle valve 3. The air pressure can be introduced into the pressure sensor through the pressure introduction passage 7 from the cylindrical space 54 that is not easily affected by the pressure fluctuation that changes. Therefore, the detection accuracy of the air pressure (intake pipe pressure) in the intake pipe can be improved.

  In addition, the air inlet of the bypass flow path 9 of the auxiliary air amount control valve is a cylindrical space 54 in a laminar flow state different from a portion that tends to be in a turbulent flow state downstream of the throttle valve 3, that is, the valve opening of the throttle valve 3. It opens at the wall surface of the cylindrical space 54 that is not affected by the turbulence of the airflow that occurs in accordance with the magnitude of the degree. As a result, the valve (valve element) of the auxiliary air amount control valve is of a type that seats with a minute gap between it and the frame-like seal wall provided in the valve housing that forms the bypass passage 9. However, when the intake air flows into the cylindrical space 54 from the air introduction port of the bypass flow channel 9, it mixes with the intake air flowing through the intake air flow channel 41 and has an irregular flow (turbulence near the air introduction port). Can be prevented from occurring. Alternatively, by opening the air introduction port of the bypass flow path 9 of the auxiliary air amount control valve so as to intersect at an approximately right angle with the inner wall surface of the bore outer pipe 52 at the downstream end of the throttle body 4, the valve opening of the throttle valve 3 is opened. Since the intake air flowing along the wall surface of the intake air passage 41 can be prevented from generating an irregular flow (turbulent flow) in the vicinity of the air inlet when the degree of opening is small, the generation of intake noise is prevented. be able to.

  Further, even when the throttle valve 3 is fully closed, the throttle valve 3 is bypassed from the air inlet formed in the intake pipe (for example, the intake duct 15) upstream of the throttle valve 3, thereby 4 through the bypass channel 9 reaching the air outlet (air inlet) formed on the wall surface of the cylindrical space 54, and further from the air inlet of the bypass channel 9 to the cylindrical space 54 and the layer of the outlet duct 5. Since the intake air can be introduced into the combustion chamber of the engine via the flow generation channel 62, the intake air channel 20 of the intake pipe 17 and the intake port 11 formed in the cylinder head 10 of the engine, Therefore, abnormal combustion and abnormal vibration of the engine due to a shortage of intake air amount can be prevented, and engine stall can be avoided.

  FIGS. 6 to 8 show a second embodiment of the present invention, FIG. 6 is a view showing an intake system of an engine for a two-wheeled vehicle, and FIGS. 7 and 8 are views showing an outlet duct.

  The body-side annular portion 23b of the flange-like body-side fitting portion 23 at the downstream end of the throttle body 4 of the present embodiment has an equal interval (for example, 30 ° interval) at the upstream-side annular shape of the body-side annular portion 23b. A plurality of through holes 91 are provided to communicate the end surface and the downstream annular end surface. In addition, a plurality of pieces that are fitted into the through-holes 91 by elastic deformation at equal intervals (for example, 30 ° intervals) in the duct-side annular portion 24b of the flange-like duct-side fitting portion 24 at the upstream end of the outlet duct 5. A protrusion (snap fit) 92 is provided. Thereby, the attachment angle of the outlet duct 5 with respect to the throttle body 4 can be made variable step by step in a predetermined angle (for example, 30 °) in the pipe circumferential direction of the throttle body 4. The same applies to the case where a screw hole is formed at the installation location of the protrusion 92 and the body-side annular portion 23b and the duct-side annular portion 24b are fastened and fixed using a fastener such as a fastening bolt or a washer. It is. In addition, between the downstream annular end surface of the body side annular portion 23b and the upstream annular end surface of the duct side annular portion 24b, the flanged body side fitting portion 23 and the flanged duct side fitting portion 24 are provided. A sealing material such as an O-ring that prevents leakage of intake air from between the two may be attached. Further, a thermal welding method such as laser welding in Example 1 may be added.

[Modification]
In this embodiment, as a valve driving means for driving the throttle valve 3 in the fully open direction or the fully closed direction, an operation amount (throttle operation amount) of a throttle lever or a throttle handle of a two-wheeled vehicle is mechanically controlled via a wire cable. 2 is transmitted to an accelerator lever (rotary body) integrated with one end of the throttle valve 3 so that the throttle valve 3 has a predetermined valve opening or a predetermined amount corresponding to the operation amount (throttle operation amount) of the throttle lever or throttle handle of the two-wheeled vehicle. Valve driving means adapted to rotate at a rotation angle is adopted. However, the rotation output of an actuator such as a drive motor is transmitted to a valve gear (rotary body) integrated with one end of the throttle shaft 2 so that the throttle Rotate to a predetermined valve opening or a predetermined rotation angle corresponding to the operation amount Unishi was the valve drive means may be employed.

  In this embodiment, the intake throttle device for an internal combustion engine according to the present invention changes the valve opening or the rotation angle of the throttle valve 3 in accordance with the operation amount (throttle operation amount) of the throttle lever or throttle handle of a two-wheeled vehicle. Although the example applied to the intake throttle device for an internal combustion engine of a two-wheeled vehicle has been described, the intake throttle device for an internal combustion engine of the present invention is a valve of the throttle valve 3 corresponding to the depression amount (accelerator operation amount) of the accelerator pedal. You may apply to the intake throttle device for internal-combustion engines of a four-wheeled vehicle which changed the opening degree or the rotation angle.

  The accelerator lever 1, the throttle shaft 2, the throttle valve 3, the throttle body 4 and the outlet duct 5 are filled with a resin material that is heated and melted (for example, a molten resin made of a thermoplastic resin) as a resin material for integrally molding the resin. A resin-based composite material (for example, polybutylene terephthalate containing 30% glass fiber: PBTG30, or 40% glass fiber) mixed with a material (for example, low-cost glass fiber, carbon fiber, aramid fiber, boron fiber, etc.) or an additive Polybutylene terephthalate containing: PBTG40) may be used. Also, by injecting the resin-based composite material from the gate into the cavity of the resin molding die, the resin throttle body, the resin throttle valve, the resin accelerator lever, or the resin throttle shaft can be obtained by injection molding of the resin-based composite material. May be manufactured. In this way, resin molded products molded integrally with resin by injection molding of resin-based composite materials are low in cost and excellent in resin moldability, as well as improved performance such as mechanical properties, strength, rigidity and heat resistance. To do.

  In this embodiment, a resin material (for example, a molten resin made of a thermoplastic resin) is used as a molten material that is heated and melted. However, a molten metal material (for example, an aluminum alloy) is used as a molten material that is heated and melted. Alternatively, a melt of a semi-molten alloy material such as a magnesium alloy may be used. That is, any one or more of the accelerator lever 1, the throttle shaft 2, the throttle valve 3, the throttle body 4, or the outlet duct 5 may be metallized. Further, the upstream end of the outlet duct 5 may be fastened and fixed to the downstream end of the throttle body 4 using a fastener such as a fastening bolt.

  In this embodiment, the intake throttle device for an internal combustion engine according to the present invention is configured so as to be able to generate a vertical vortex (tumble flow) that promotes combustion of the engine. You may comprise so that generation | occurrence | production of a vortex flow (swirl flow) is attained. Further, the intake throttle device for an internal combustion engine of the present invention may be configured such that generation of a squish vortex that promotes combustion of the engine is possible.

  In the present embodiment, for example, even when the valve opening of the throttle valve 3 is small, the flow velocity and directionality of the intake air flowing into the intake port of the internal combustion engine is ensured and mixed in the combustion chamber of the engine. For the purpose of generating a tumble flow for promoting the combustion of air, the flow velocity is relatively high, and the drift or laminar flow is such that the intake air is blown locally to the wall surface of the intake port 11 or one side of the intake valve 13. Is formed between the outer periphery of the bore inner pipe 63 and the inner periphery of the bore outer pipe 64 of the outlet duct 5. 62 may be formed between the bore inner tube 51 and the bore outer tube 52 of the throttle body 4. In this case, a communication path 65 is provided between the downstream end of the cylindrical space 54 and the upstream end of the laminar flow generation channel 62.

  Further, instead of the laminar flow generation flow path 62, atomization of the fuel spray injected from the injection hole of the injector 8 is performed without generating a vortex for promoting combustion of the air-fuel mixture in the combustion chamber of the engine. For the purpose of promoting, the outlet duct (second tubular body) 5 is provided with a laminar flow generation flow path for generating a drift or laminar flow that blows assist air locally in the vicinity of the injection hole of the injector 8. It may be provided. Further, instead of the laminar flow generation flow path 62 described above, the intake air flowing from the intake air flow path 41 of the throttle body 4 is not generated without generating a vortex for promoting the combustion of the air-fuel mixture in the combustion chamber of the engine. An airflow characteristic imparting flow path having an airflow characteristic having a relatively high flow velocity or an airflow characteristic for promoting atomization of the fuel spray injected from the injection hole of the injector 8 is provided in the outlet duct (second duct). (2 tubular bodies) 5 may be provided.

  In this embodiment, on the wall surface of the bore outer pipe 52 of the throttle body 4, a pressure introduction pipe 71 that forms the pressure introduction passage 7 of the pressure sensor and an auxiliary air introduction pipe that forms the bypass flow path 9 of the auxiliary air amount control valve. 72 is integrally provided, but either the pressure introduction pipe 71 or the auxiliary air introduction pipe 72 may be integrally provided on the wall surface of the bore outer pipe 64 of the outlet duct 5. Further, either the pressure introducing pipe 71 or the auxiliary air introducing pipe 72 may be provided on the wall surface of the intake pipe 17. Further, the positional relationship between the pressure introduction port of the pressure introduction passage 7 of the pressure sensor and the air outlet portion of the bypass passage 9 of the auxiliary air amount control valve is not limited to this embodiment, but preferably the pressure sensor. At a position farthest from the pressure inlet of the pressure introduction passage 7 and the air outlet of the bypass flow passage 9 of the auxiliary air amount control valve (about 90 to 270 ° in the pipe circumferential direction of the bore outer pipe 52, preferably 180 ° It is desirable to provide the

  In this embodiment, a cylindrical space communicated in parallel with the intake air flow path 41 into the combustion chamber of the engine between the bore inner pipe 51 and the bore outer pipe 52 constituting the bore wall portion of the throttle body 4. The pressure introduction passage 7 of the pressure sensor and the bypass passage 9 of the auxiliary air amount control valve that communicate with the cylindrical space 54 are symmetrically shown in the vertical direction in the drawing with the central axis of the throttle body 4 as the symmetry plane. However, a partition wall that divides the cylindrical space 54 into two or more spaces (for example, a semicircular cylindrical space or a substantially crescent-shaped space) is provided, and the pressure sensor pressure introduction passage 7 and the auxiliary are provided in independent spaces. You may make it make the bypass flow path 9 of an air quantity control valve communicate.

1 is a partial cross-sectional view showing an intake system of an engine for a motorcycle (Example 1). (A) is the rear view which showed the main structures of the intake throttle device for internal combustion engines, (b) is the side view which showed the main structures of the intake throttle device for internal combustion engines (Example 1). (A) is the side view which showed the main structures of the intake throttle device for internal combustion engines, (b) is the front view which showed the main structures of the intake throttle device for internal combustion engines (Example 1). (Example 1) which is AA sectional drawing of FIG.3 (b). (A) is the rear view which showed the outlet duct, (b) is the side view which showed the outlet duct, (c) is BB sectional drawing of (a) (Example 1). (Example 2) which is the fragmentary sectional view which showed the intake system of the engine for two-wheeled motor vehicles. (Example 2) which is the rear view which showed the outlet duct. (A) is CC sectional drawing of FIG. 7, (b) is D view of (a) (Example 1). (A) is the fragmentary sectional view which showed the intake system of the engine for two-wheeled motor vehicles, (b) is sectional drawing which showed EE sectional drawing of (a) (comparative example).

Explanation of symbols

2 Throttle shaft 3 Throttle valve 4 Throttle body (first tubular body of intake pipe)
5 Outlet duct (second tubular body of intake pipe)
7 Pressure introduction passage 8 Injector (fuel injection valve)
9 Bypass passage (auxiliary air passage)
10 Cylinder Head of Motorcycle Engine 11 Intake Port of Motorcycle Engine 13 Intake Valve (Intake Valve) of Motorcycle Engine
23 Fitting body side fitting portion of throttle body 24 Fitting shape duct side fitting portion 41 Throttle body intake air flow path 51 Bore inner pipe (cylindrical partition wall)
52 Bore outer pipe 54 Cylindrical space 61 Inlet air flow path of outlet duct 62 Laminar flow generation flow path (vortex flow generation flow path, flow characteristic imparting flow path) of outlet duct
63 Bore inner pipe (partition wall)
64 Bore outer pipe 65 Communication path 71 Pressure introduction pipe 72 Auxiliary air introduction pipe 73 Air intake of laminar flow generation flow path 74 Air blowout of laminar flow generation flow path

Claims (12)

(A) an intake pipe through which intake air flows toward the intake port of the internal combustion engine,
(B) In an intake throttle device for an internal combustion engine provided with a butterfly valve type throttle valve having a rotation center axis perpendicular to the average direction of the flow of intake air flowing in the intake pipe,
The intake pipe accommodates the throttle valve so as to be openable and closable, and has a first tubular body having an intake air flow path whose flow path opening area is changed according to the valve opening of the throttle valve, and the first tubular body A laminar flow that is directly or indirectly coupled to the downstream end of the body and generates a drift or laminar flow that blows intake air locally to the wall of the intake port of the internal combustion engine or one side of the intake valve A second tubular body having a generation flow path,
An intake throttle device for an internal combustion engine, wherein an attachment angle of the second tubular body with respect to the first tubular body is variable in a pipe circumferential direction of the first tubular body. The intake throttle device for an internal combustion engine according to claim 1,
The laminar flow generation flow path ensures a flow velocity and directionality of intake air flowing into the intake port of the internal combustion engine, and generates a vortex for promoting combustion of the air-fuel mixture in the combustion chamber of the internal combustion engine. An intake throttle device for an internal combustion engine, wherein The intake throttle device for an internal combustion engine according to claim 1,
The laminar flow generation flow path gives the intake air flowing in from the intake air flow path of the first tubular body the airflow characteristic having a relatively high flow velocity or the fuel injected from the injection hole of the fuel injection valve An intake throttle device for an internal combustion engine, characterized by being an airflow characteristic imparting flow path having airflow characteristics for promoting atomization of spray. The intake throttle device for an internal combustion engine according to any one of claims 1 to 3,
An air outlet for blowing out intake air toward the intake port of the internal combustion engine is provided at the downstream end of the laminar flow generation flow path,
The intake air throttle device for an internal combustion engine, wherein the air outlet is opened at a position that is eccentric in a direction perpendicular to a central axis direction of the second tubular body. The intake throttle device for an internal combustion engine according to claim 4,
At the upstream end of the laminar flow generation channel, an air intake for taking in the intake air from the intake air channel into the laminar flow generation channel is provided,
The air inlet has an opening cross-sectional area wider than the air outlet;
The intake air throttle device for an internal combustion engine, wherein the air outlet is provided at only one location. The intake throttle device for an internal combustion engine according to claim 4 or 5,
At the upstream end of the laminar flow generation channel, an air intake for taking in the intake air from the intake air channel into the laminar flow generation channel is provided,
The internal combustion engine, wherein the laminar flow generation flow path is provided so that a cross-sectional area of the flow path gradually decreases from the middle of the air intake port or the laminar flow generation flow path toward the air outlet. Intake throttle device. The intake throttle device for an internal combustion engine according to any one of claims 4 to 6,
The internal combustion engine is equipped with a fuel injection valve provided with an injection hole for injecting fuel spray toward an intake port of the internal combustion engine in the vicinity of a flow path of intake air blown from the air outlet. An intake throttle device for an internal combustion engine characterized by the above. The intake throttle device for an internal combustion engine according to any one of claims 1 to 7,
The first tubular body is provided in parallel to the intake air flow path so as to surround the intake air flow path, and opens only at the downstream end of the first tubular body to generate the laminar flow. Having a space communicating with the flow path;
An intake throttle device for an internal combustion engine having a partial double pipe structure by partitioning the intake air flow path and the space with a cylindrical partition on the downstream side of the first tubular body. The intake throttle device for an internal combustion engine according to claim 8,
The first tubular body is provided with a pressure sensor,
The intake air throttle device for an internal combustion engine, wherein the pressure sensor has a pressure introduction passage communicating with the space, and detects an air pressure introduced from the pressure introduction passage. The intake throttle device for an internal combustion engine according to claim 8 or 9,
An auxiliary air amount control valve is installed in the first tubular body,
The auxiliary air amount control valve has an auxiliary air passage that bypasses the throttle valve and communicates with the space, and adjusts the amount of auxiliary air that flows through the auxiliary air passage when the throttle valve is fully closed. An intake air throttle device for an internal combustion engine. The intake throttle device for an internal combustion engine according to any one of claims 1 to 10,
The first tubular body and the second tubular body are each integrally formed of a resin material,
An intake throttle device for an internal combustion engine, wherein the downstream end of the first tubular body and the upstream end of the second tubular body are joined together by heat welding. The intake throttle device for an internal combustion engine according to any one of claims 1 to 10,
The first tubular body and the second tubular body are each integrally formed of a resin material,
A plurality of engagement holes are formed at equal intervals in the pipe circumferential direction of the first tubular body at the downstream end of the first tubular body,
A plurality of engaging claws are formed at equal intervals in the pipe circumferential direction of the second tubular body at the upstream end of the second tubular body,
By fitting the plurality of engaging claws of the second tubular body into the plurality of engaging holes of the first tubular body using elastic deformation, the downstream end of the first tubular body and the second tubular body An intake throttle device for an internal combustion engine, which is connected to the upstream end of the engine.

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