JP2010116794A - Intake system for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake system for an internal combustion engine, suppressing deformation of an intake passage and achieving weight reduction. <P>SOLUTION: This intake system for the internal combustion engine includes: a throttle body 21 formed with a bore 30; a throttle valve 22 rotatably supported by the throttle body 21 and used for throttle control of the passage of the bore 30; an intake manifold 3 formed with an intake passage 41 communicating with the bore 30; a communication pipe 31 projecting from one of the throttle body 21 and intake manifold 3, having an outer peripheral surface formed with a male thread 31a, and used for connecting the bore 30 to the intake passage 41; and a communication pipe retaining section 42 formed on the other of the throttle body 21 and intake manifold 3, and having an inner peripheral surface formed with a female thread 42a screwed around the male thread 31a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an intake device for an internal combustion engine, and more particularly to a connection structure between a throttle device and an intake member such as an intake manifold.

  When connecting the throttle device main body (hereinafter referred to as the throttle body) and the intake manifold, there is a method in which flanges are formed at the respective connecting ends, and each flange is fastened with a bolt or the like via a seal member such as a gasket. Often taken. However, when the throttle body is formed of a resin material, the flange surface is deformed by fastening due to low flatness of the flange surface or reaction force from the seal member, and accordingly, the intake passage in the throttle body There was also a problem of deformation. When the intake passage is deformed, the intake flow rate naturally changes, so there is a possibility that optimum combustion control may be hindered.

In order to solve the above-described problems, a connecting pipe protrudes from the connecting end of the throttle body, and this connecting pipe is inserted into the connecting end of the intake manifold, and the outer peripheral surface of the connecting pipe and the inner peripheral surface of the intake passage of the intake manifold A connection structure has been proposed in which a seal member is interposed between the two so that the reaction force by the gasket is not transmitted to the flange (for example, Patent Document 1).
Japanese Patent No. 3620034

  However, even in the connection structure according to Patent Document 1, a flange is provided in the throttle body and is fastened by a fastening clip in a state where the flange and the connection end of the intake manifold are in contact with each other. When the flatness is low, the problem that the flange is deformed at the time of fastening and the intake passage in the throttle body is deformed cannot be solved. Further, since the throttle body has a flange, it becomes larger in the radial direction, which increases the weight and limits the layout.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an intake device for an internal combustion engine that can suppress the deformation of the intake passage of the resin throttle body and can be reduced in weight.

  In order to solve the above-mentioned problem, the first invention of the present invention is a throttle body (21) in which a first intake passage (bore 30) is formed, and is rotatably supported by the throttle body. A throttle valve (22) used for passage restriction control, an intake member (intake manifold 3) formed with a second intake passage (41) communicating with the first intake passage, the throttle body, and the intake member And a male pipe (31a) formed on the outer peripheral surface, a connecting pipe (31) used for connecting the first intake passage and the second intake passage, and the throttle body And a connection pipe holding portion (42) formed on the inner peripheral surface of a female screw (42a) screwed into the male screw.

  According to this configuration, the throttle body and the intake member are coupled by screwing the connecting pipe and the connecting pipe holding portion. Therefore, it is not necessary to provide a flange at the coupling end between the throttle body and the intake member. By eliminating the fastening by the flange, it is possible to eradicate the occurrence of fastening distortion due to the flange and reduce the weight.

  A second invention is characterized in that, in the first invention, the male screw is a sawtooth screw having a flank angle on the base end side smaller than a flank angle on the tip end side.

  According to this configuration, the resistance against a load in the direction in which the connecting pipe is detached from the connecting pipe holding portion is increased, and the coupled state is stabilized.

  According to a third invention, in the first or second invention, the male screw is an intermittent screw in which a screw thread is intermittently formed.

  According to this configuration, since the male screw can release stress caused by screwing with the female screw in the circumferential direction of the connecting pipe, it is possible to prevent the stress from being applied to the connecting pipe and the intake passage.

  According to a fourth invention, in any one of the first to third inventions, a seal member (O-ring 47) is interposed between the connection pipe and the connection pipe holding portion.

  According to this configuration, since the connection between the connection pipe and the connection passage is performed airtightly via the seal member, it is possible to prevent air leakage between the first intake passage and the second intake passage. Further, since the seal member is disposed on the outer peripheral portion of the connecting pipe that is a circular pipe, the connecting pipe can resist deformation of the intake passage against the reaction force of the seal member.

  According to a fifth invention, in any one of the first to fourth inventions, there is provided a regulating means for regulating relative rotation of the throttle body and the intake member around the connecting pipe.

  According to this configuration, since the relative rotation of the throttle body and the intake member around the connecting pipe is prevented, the screwing of the male screw and the female screw is maintained, and the coupled state of the throttle body and the intake member is maintained.

  According to a sixth aspect based on the fifth aspect, the restricting means includes a first flange (flange 36) extending from the throttle body and having a first through hole (37), and the intake member. A second flange (44) that is extended and has a first hole (screw hole 45), and a first connecting member (bolt 46) that is inserted through the first through hole and the first hole. The first through hole and the first hole are characterized in that their axes coincide with each other in a state where the throttle body and the intake member are connected.

  According to this configuration, relative rotation around the connecting pipe between the throttle body and the intake member can be reliably prevented with a simple configuration.

  In a seventh aspect based on the sixth aspect, the throttle body includes a motor accommodating portion (33) for accommodating an electric motor (23) used for driving the throttle valve, and the throttle for driving force of the electric motor. A transmission mechanism accommodating portion (34) that accommodates a power transmission mechanism (24) used for transmission to the valve, and the first through hole and the first intake passage in the axial direction of the connection pipe It is located between the motor accommodating part and the transmission mechanism accommodating part.

  According to this configuration, since the space surrounded by the first intake passage, the motor housing portion, and the transmission mechanism housing portion is used when the connecting pipe is viewed in the axial direction, the throttle body can be made compact and lightweight. Moreover, since the 1st connection member will be provided in the position close | similar to a motor accommodating part and a transmission mechanism accommodating part, the vibration of an electric motor and a power transmission mechanism can be suppressed effectively.

  In an eighth aspect based on the seventh aspect, the motor housing portion is disposed such that a rotation shaft (23a) of the electric motor is parallel to a rotation shaft (throttle shaft 22a) of the throttle valve, and the throttle body Is provided with a third flange (50) having a second through hole (51) in the vicinity of the end of the motor accommodating portion on the side different from the end on the transmission mechanism accommodating portion side, A fourth flange having a fourth through hole whose axial center coincides with the second through hole in a state in which the throttle body and the intake member are coupled, and the second through hole and the fourth through hole; Further, the second connecting member is inserted.

  According to this configuration, since the connecting member is provided close to both ends of the motor rotation shaft, vibration generated from the electric motor can be effectively suppressed.

  According to a ninth invention, in any one of the first to eighth inventions, the throttle body is made of a resin material.

  According to this configuration, the weight of the intake device can be reduced and the manufacturing cost can be reduced.

  According to the above configuration, it is possible to obtain an intake device in which the throttle body is connected to the intake member without deforming the first intake passage formed in the throttle body. Since the connection structure of the intake device is simple, the weight of the intake device can be reduced, the manufacturing cost can be reduced, and the workability of the assembling work can be improved.

  Embodiments in which the present invention is applied to an intake device for an automobile engine will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of the intake device according to the first embodiment, and FIG. 2 is an exploded perspective view of the intake device according to the first embodiment.

  As shown in FIGS. 1 and 2, the intake device 1 of the first embodiment includes an electronic control throttle device 2 and an intake manifold 3 connected to the downstream side of the electronic control throttle device 2 as main components. The upstream end of the electronically controlled throttle device 2 is connected to the downstream end of an intake duct 4 communicating with an air cleaner (not shown), and the downstream end of the intake manifold 3 is an in-line 4-cylinder gasoline engine (hereinafter abbreviated as an engine) E for automobiles. The cylinder head E1 is connected via an injector base (not shown). The intake manifold 3 is an injection molded product of a resin material.

  The electronically controlled throttle device 2 includes a throttle body 21, a throttle valve 22, an electric motor 23 that generates driving force for the throttle valve 22, and a power transmission mechanism (deceleration mechanism) 24 that transmits the driving force of the electric motor 23 to the throttle valve 22. It is configured. The electric motor 23 is driven and controlled by an ECU (not shown), and the power transmission mechanism 24 transmits the driving force of the electric motor 23 to the throttle valve 22.

  As shown in FIG. 2, the throttle body 21 includes a bore 30 having a circular cross section forming an intake passage therein, a connecting pipe 31 projecting coaxially at one end of the bore 30, and coaxially at the other end of the bore 30. A projecting intake duct connecting portion 32 and a motor housing portion 33 and a transmission mechanism housing portion 34 projecting from the outer periphery of the bore 30 are provided. The throttle body 21 is an injection molded product of a resin material.

  FIG. 3 is a plan view showing a main part of the intake device according to the first embodiment, and shows a state in which the intake duct is removed. 4 is a cross-sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is a cross-sectional view taken along line V-V in FIG. As shown in FIGS. 3 and 4, a throttle shaft 22a of a throttle valve 22 is rotatably supported on the bore 30 via a bearing (not shown). The connecting pipe 31 is formed so that the inner diameter is equal to the inner diameter of the bore 30 and the outer diameter is smaller than the outer diameter of the bore 30, and the flank angle on the proximal end side is the flank angle on the distal end side on the outer peripheral surface thereof. A smaller male thread 31a is formed. The sawtooth screw is preferably formed with a very small flank angle on the base end side (about 0 to 3 °). The male screw 31a is an intermittent screw in which a screw thread is intermittently formed.

  The intake duct coupling portion 32 has a circular tube shape, and a tip end portion 32a is formed to protrude radially outward over the entire circumference. As shown in FIG. 1, the intake duct coupling portion 32 is inserted into the downstream end of the intake duct 4 and fastened to the intake duct 4 by an annular hose clamp 35 provided on the outer peripheral portion of the intake duct 4. . The distal end portion 32 a sandwiches the intake duct 4 between the front end portion 32 a and the hose clamp 35, and acts as a stopper for removing the intake duct 4.

  The motor accommodating portion 33 has a space for accommodating and supporting the electric motor 23 therein, and is arranged so that the rotating shaft 23a of the electric motor 23 to be supported is parallel to the throttle shaft 22a. One end of the transmission mechanism accommodating portion 34 is connected to the drive end side of the electric motor 23 of the motor accommodating portion 33, and the other end is connected to a portion where one end of the throttle shaft 22 a of the bore 30 is located. The transmission mechanism accommodating portion 34 has a space for supporting the power transmission mechanism 24 therein, and the output end of the rotating shaft 23a of the electric motor 23 and one end of the throttle shaft 22a extend into this space. The power transmission mechanism 24 is composed of one or more reduction gears, and is interposed between the output end of the rotating shaft 23a of the electric motor 23 and one end of the throttle shaft 22a to reduce the driving force of the electric motor 23. This is transmitted to the throttle shaft 22a.

  As shown in FIG. 3, a flange 36 is formed in a portion surrounded by the bore 30, the motor housing portion 33, and the transmission mechanism housing portion 34, and the flange 36 is parallel to the axial direction of the bore 30. A through-hole 37 is formed.

  An intake passage 41 of the intake manifold 3 is formed in a tubular shape, and a tubular connection tube holding portion 42 into which the connection tube 31 is inserted is formed at the coupling end with the throttle body 21. On the inner peripheral surface of the connecting pipe holding portion 42, an internal thread 42a that is screwed with the external thread 31a of the connecting pipe 31 is formed.

  As shown in FIGS. 2 and 5, a flange 44 projecting radially outward is formed on the outer peripheral surface of the connecting pipe holding portion 42, and a screw hole 45 is formed in the flange 44. Yes. In a state where the throttle body 21 is coupled to the intake manifold 3, that is, in a state where the male screw 31 a of the connecting pipe 31 is screwed to the female screw 42 a of the connecting pipe holding portion 42, the axis line between the screw hole 45 and the through hole 37 of the throttle body 21. The flange 44 and the screw hole 45 are arranged so as to match.

  To connect the throttle body 21 and the intake manifold 3, an O-ring 47 is interposed between the connecting pipe 31 and the connecting pipe holding part 42, and the male screw 31 a of the connecting pipe 31 and the female screw 42 a of the connecting pipe holding part 42 are screwed. This is done by combining them. The O-ring 47 is disposed at the base end portion of the connecting pipe 31 and is sandwiched between the outer peripheral surface of the connecting pipe 31 and the inner peripheral surface of the connecting pipe holding portion 42 in the radial direction of the connecting pipe 31. 31 is sandwiched between the end face of the bore 30 and the female screw 42a in the axial direction.

  In a state where the throttle body 21 is coupled to the intake manifold 3, the bolt 46 is inserted into the through hole 37 and the screw hole 45, and the rotation around the connecting pipe 31 between the throttle body 21 and the intake manifold 3 is restricted. The fastening force of the bolt 46 and the screw hole 45 is adjusted so that the flange 36 of the throttle body 21 is not deformed by fastening, and the throttle body 21 and the intake manifold 3 are loosely fastened.

  The effect of 1st Embodiment comprised as mentioned above is demonstrated. The throttle body 21 and the intake manifold 3 of the intake device 1 in the first embodiment are fastened by screwing the connecting pipe 31 and the connecting pipe holding portion 42. Therefore, it is not necessary to provide a fastening flange at each coupling end of the throttle body 21 and the intake manifold 3, and the weight and size can be reduced. Further, since the fastening between the throttle body 21 and the intake manifold 3 is not performed by the fastening flange, the deformation of the bore 30 at the time of fastening due to the low flatness of the flange surface is prevented.

  Since the connection between the connection pipe 31 and the connection pipe holding part 42 is performed by screwing of a saw-tooth screw, the resistance to the load in the direction in which the connection pipe 31 is detached from the connection pipe holding part 42 is large, and the connection state is Stabilize. Further, since the male screw 31a is an intermittent screw, when the male screw 31a and the female screw 42a are screwed together, stress is not easily applied to the male screw 31a, and deformation of the connecting pipe 31 is suppressed.

  Since the O-ring 47 is disposed in contact with the end face of the bore 30, the reaction force of the O-ring 47 is applied in the axial direction of the bore 30. Therefore, the bore 30 can resist the reaction force of the O-ring 47, and deformation is suppressed. Further, the reaction force of the O-ring 47 is also applied to the outer peripheral surface of the connecting pipe 31, but the connecting pipe 31, which is a circular pipe, is strong against a load applied to the outer peripheral surface, so that deformation is suppressed and deformation of the bore 30 is suppressed. The

  In a state where the throttle body 21 is coupled to the intake manifold 3, the bolt 46 is inserted into the through hole 37 and the screw hole 45, so that relative rotation between the throttle body 21 and the intake manifold 3 is restricted. Therefore, the connection state between the throttle body 21 and the intake manifold 3 is stably maintained. Further, since the throttle body 21 and the intake manifold 3 are loosely fastened by the bolts 46, vibrations generated from the electric motor 23 are suppressed. The flange 36 having the through hole 37 uses a space surrounded by the bore 30, the motor housing portion 33, and the transmission mechanism housing portion 34 in the axial direction of the connecting pipe 31, so that the throttle body 21 can be made compact and lightweight. Can be achieved.

  Next, a partially modified embodiment of the first embodiment will be described. FIG. 6 is a plan view showing a main part of an intake device according to a partially modified embodiment of the first embodiment. The throttle body 21 according to the partially modified embodiment includes a flange 50 extending from the side different from the drive end side of the motor housing portion 33 to the outer peripheral surface of the bore 30, and a portion adjacent to the motor housing portion 33 of the flange 50. A through hole 51 is formed. A flange (not shown) projecting radially outward is formed on the outer peripheral surface of the connecting pipe holding portion 42, and a screw hole (not shown) is formed in the flange. In a state where the throttle body 21 is coupled to the intake manifold 3, the flange 44 and the screw hole 45 are arranged so that the axes of the screw hole and the through hole 37 of the throttle body 21 coincide with each other. Bolts are inserted into the through holes 37 and the screw holes and tightened loosely.

  With the above configuration, the throttle body 21 is fastened to the intake manifold 3 in the vicinity of both ends of the motor accommodating portion 33, so that vibration of the electric motor 23 is effectively suppressed.

  Although the description of the specific embodiment is finished as above, the present invention is not limited to the above embodiment and can be widely modified. For example, instead of the electronically controlled throttle device 2, a mechanical throttle device 60 including an accelerator drum 61 connected to an accelerator via an accelerator wire is used, and the throttle body does not have a motor housing portion or the like. In this case, as shown in FIG. 7, a flange portion 63 having a through hole 62 formed at an arbitrary position is projected, and a flange having a screw hole is projected on the corresponding connecting pipe holding portion of the intake manifold. You may set up. The through holes 37 and 51 may be long holes. The configuration of other devices can be appropriately changed without departing from the spirit of the invention.

1 is a perspective view of an intake device according to a first embodiment. 1 is an exploded perspective view of an intake device according to a first embodiment. It is a top view which shows the principal part of the intake device which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the principal part of the intake device which concerns on 1st Embodiment. It is VV sectional drawing of FIG. It is a top view which shows the principal part of the intake device which concerns on the partial modification embodiment of 1st Embodiment. It is a top view which shows the principal part of the intake device which concerns on deformation | transformation embodiment.

Explanation of symbols

  1: intake device, 2: electronic control throttle device, 3: intake manifold, 21: throttle body, 22: throttle valve, 22a: throttle shaft, 23: electric motor, 23a: rotating shaft, 24: power transmission mechanism, 30: Bore, 31: connecting pipe, 31: male thread, 33: motor housing section, 34: transmission mechanism housing section, 36: flange, 37: through hole, 41: intake passage, 42: coupling pipe holding section, 42a: female thread, 44 : Flange, 45: Screw hole, 46: Bolt, 47: O-ring

Claims (9)

A throttle body in which a first intake passage is formed;
A throttle valve rotatably supported by the throttle body and used for throttle control of the first intake passage;
An intake member formed with a second intake passage communicating with the first intake passage;
A projecting pipe projecting from one of the throttle body and the intake member and having a male screw formed on an outer peripheral surface thereof, and a connection pipe provided for connection between the first intake passage and the second intake passage;
An intake air for an internal combustion engine, comprising: a connecting pipe holding portion formed on an inner peripheral surface of the throttle body and the intake device, and having an internal thread that engages with the external thread. apparatus.   2. The intake device for an internal combustion engine according to claim 1, wherein the male screw is a sawtooth screw having a flank angle on a proximal end side smaller than a flank angle on a distal end side.   The intake device for an internal combustion engine according to claim 1 or 2, wherein the male screw is an intermittent screw in which a screw thread is intermittently formed.   The intake device for an internal combustion engine according to any one of claims 1 to 3, wherein a seal member is interposed between the connection pipe and the connection pipe holding portion.   The intake device for an internal combustion engine according to any one of claims 1 to 4, further comprising a restricting means for restricting relative rotation of the throttle body and the intake member around the connecting pipe. . A first flange that extends from the throttle body and has a first through hole; a second flange that extends from the intake member and has a first hole; A first connecting member inserted through the first through hole and the first hole;
6. The intake air of the internal combustion engine according to claim 5, wherein the first through hole and the first hole have the same axial center when the throttle body and the intake member are connected to each other. apparatus. The throttle body includes a motor housing portion that houses an electric motor that is used to drive the throttle valve, and a transmission mechanism housing that houses a power transmission mechanism that is used to transmit the driving force of the electric motor to the throttle valve. With
The said 1st through-hole is located among the said 1st intake passage, the said motor accommodating part, and the said transmission mechanism accommodating part in the axial direction view of the said connecting pipe, The Claim 6 characterized by the above-mentioned. An intake device for an internal combustion engine. The motor accommodating portion is arranged so that the rotation shaft of the electric motor is parallel to the rotation shaft of the throttle valve,
The throttle body includes a third flange having a second through hole in the vicinity of an end portion on a side different from the end portion on the transmission mechanism housing portion side of the motor housing portion,
The intake member includes a fourth flange including a fourth through hole whose axial center coincides with the second through hole in a state in which the throttle body and the intake member are coupled to each other.
The intake device for an internal combustion engine according to claim 7, wherein a second connecting member is inserted through the second through hole and the fourth through hole.   The intake device for an internal combustion engine according to any one of claims 1 to 8, wherein the throttle body is made of a resin material.

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