JP2012211510A - Ventilation structure of drive chamber in throttle body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the enlargement of a body size and the complication of a metal mold structure when forming a housing protruding sideways from a body main part constituting an intake passage, and a ventilation hole at the body side for ventilating the drive chamber which is formed between a cover attached to the housing and itself.SOLUTION: The housing 7b is composed of a cylindrical neck 7ba extending in the axial direction of a valve shaft 12, and a box-shaped part 7bb hanging out sideways from the external end of the neck 7ba, and a cylindrical protrusion 30 forming the ventilation hole 26 extends in a direction in which the protrusion progresses toward a plane PL including the center axial line of the intake passage 6 and the axial line of the valve shaft 12, and is formed at the neck 7ba so as to be arranged within a projection area line of the box-shaped part 7bb in a direction in which the protrusion progresses along the axial line of the valve shaft 12.

Description

  According to the present invention, a drive chamber is formed between a housing having a cylindrical body main part forming an intake passage and a body integrally having a housing part protruding laterally from the body main part. A cover attached to the housing portion, a throttle valve arranged in the intake passage so that the opening degree of the intake passage can be changed, and one end portion entering the drive chamber while crossing the intake passage A throttle body comprising a valve shaft that is rotatably supported by the body and to which the throttle valve is fixed, and a drive mechanism that is housed in the drive chamber so as to rotationally drive the valve shaft. In particular, the present invention relates to the improvement of the ventilation structure of the driving room.

  A housing part provided in the throttle body and a cover fastened to the housing part form a driving chamber that houses the driving mechanism, and the outer end is made of a waterproof and air-permeable membrane material to ventilate the driving chamber. Japanese Patent Application Laid-Open No. H10-228707 discloses a ventilation hole provided in the cover so that the opening is covered.

JP 2008-184941 A

  However, in the one disclosed in Patent Document 1, the ventilation part is exposed to the outside, and there is a possibility that foreign matter such as mud adheres to the ventilation part. Therefore, it is difficult for foreign matter such as mud to adhere to it as much as possible, and it is possible to secure a space for breathing and to provide a ventilation hole in the concave part on the body side. I want to avoid the complicated mold structure.

  The present invention has been made in view of such circumstances, and in providing a ventilation hole on the body side, it is possible to avoid an increase in the size of the body or a complicated mold structure. It aims at providing the ventilation structure of a driving room.

  In order to achieve the above object, the present invention provides a tubular body main portion forming an intake passage and a body integrally including a housing portion protruding laterally from the body main portion, and the housing portion. A cover that is attached to the housing portion so as to form a drive chamber, a throttle valve that is arranged in the intake passage so that the opening degree of the intake passage can be changed, and crossing the intake passage A valve shaft that is pivotally supported by the body so that one end thereof enters the drive chamber and is fixed to the throttle valve, and is housed in the drive chamber so as to rotationally drive the valve shaft. In the throttle body provided with a drive mechanism, the housing portion extends in the axial direction of the valve shaft and is connected to the main body portion of the cylinder, and from the outer end of the neck portion to the side. Zhang A ventilation hole that allows ventilation of the drive chamber and extends in a direction toward a plane including the central axis of the intake passage and the axis of the valve shaft. A first feature is that the neck portion is provided so as to be disposed within a projection plane line of the box-shaped portion in a direction along the axis of the valve shaft.

  According to the present invention, in addition to the configuration of the first feature, a membrane material insertion hole having a diameter larger than that of the ventilation hole is disposed in a projection plane line of the box-shaped portion in a direction along the axis of the valve shaft. As described above, a membrane material that is connected to the outer end of the ventilation hole and has a waterproof ventilation property is fixed in contact with a step formed between the ventilation hole and the membrane material insertion hole. A second feature is that the membrane material is inserted into the membrane material insertion hole while covering the ventilation hole.

  In the present invention, in addition to the configuration of the second feature, a plug insertion hole having a diameter larger than that of the membrane material insertion hole is disposed in a projection plane line of the box-shaped portion in a direction along the axis of the valve shaft. In this way, the plug that is connected to the outer end of the membrane material insertion hole and plugs the plug insertion hole is fitted and fixed in the plug insertion hole, and the membrane material insertion hole between the plug and the membrane material is formed. A third feature is that an opening communicating with the outside is provided in a side wall of the film material insertion hole and the plug insertion hole.

  According to the present invention, in addition to the configuration of the third feature, the ventilation hole, the membrane material insertion hole, and the plug insertion hole are provided in a cylindrical projection protruding from the neck portion, and the opening A fourth feature is that a part of the groove is formed by a part of a groove provided on the outer periphery of the protrusion along the longitudinal direction thereof.

  Furthermore, the present invention provides the structure according to the fourth feature, wherein the groove is provided on an outer periphery of the protrusion so as to face an air cleaner connected to the main body portion so as to pass through the upstream end of the intake passage. The fifth feature is that the air cleaner is formed so as to hide the groove when viewed from the air cleaner side.

  According to the first feature of the present invention, the housing part protruding laterally from the cylindrical body main part forming the intake passage is stretched laterally from the cylindrical neck part and the outer end of the neck part. The ventilation hole is provided in the neck portion so as to extend in a direction toward the plane including the central axis of the intake passage and the axis of the valve shaft. This makes it possible to simplify the mold structure when molding the molded body. Further, since the ventilation hole is disposed within the projection plane line of the box-shaped portion in the direction along the axis of the valve shaft, avoiding an increase in the size of the body while ensuring a space for breathing, It is possible to prevent foreign matters such as mud from adhering.

  According to the second feature of the present invention, since the ventilation hole is covered with a waterproof and breathable membrane material, ventilation can be performed while preventing water from entering the driving chamber from the ventilation hole. The membrane material insertion hole for inserting the material is connected to the outer end of the ventilation hole, and the membrane material insertion hole is disposed in the projection plane line of the box-shaped portion in the direction along the axis of the valve shaft. While making it possible to prevent foreign matter from adhering to the material, an increase in the size of the body can also be avoided.

  According to the third feature of the present invention, since the plug insertion hole closed by the plug is connected to the outer end of the membrane material insertion hole, it is possible to more reliably prevent the entry of foreign matters such as mud into the membrane material side. In addition, since the plug insertion hole is disposed within the projection plane line of the box-shaped portion in the direction along the axis of the valve shaft, the body does not increase in size due to the installation of the plug. In addition, since an opening that allows the membrane material insertion hole between the plug and the membrane material to communicate with the outside is provided on the side wall of the plug insertion hole, the drive chamber can be ventilated through the membrane material, and the opening can be easily formed. It is.

  According to the fourth aspect of the present invention, the ventilation hole, the membrane material insertion hole, and the plug insertion hole are provided in a cylindrical projection protruding from the neck portion, and a part of the opening is the projection. Since it is formed with grooves provided along the longitudinal direction of the outer periphery, it is easy to form openings and grooves, and since the grooves can be formed relatively long, foreign matter such as mud is difficult to accumulate, The opening is not blocked.

  Furthermore, according to the fifth feature of the present invention, since the groove provided on the outer periphery of the protrusion facing the air cleaner side is hidden by the air cleaner when viewed from the air cleaner side, foreign matter such as mud in the groove and the opening is removed. Intrusion can be suppressed.

It is a partially cutaway side view of a throttle body. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 4 attached herewith. First, in FIG. 1 and FIG. 2, this throttle body 5 is a part of an intake system in a motorcycle engine, for example. A body 7 having a cylindrical body main portion 7a that forms the intake passage 6 and a housing portion 7b that protrudes laterally from the body main portion 7a, and the housing portion 7b. A cover 10 that is attached to the housing portion 7b with a plurality of screw members 9, 9,... So as to form a drive chamber 8, and the opening degree of the intake passage 6 can be changed and disposed in the intake passage 6. The throttle valve 11 is supported by the body 7 so that one end of the throttle valve 11 penetrates the drive chamber 8 while traversing the intake passage 6 and the throttle valve 11 is rotated. It includes a valve shaft 12 Le valve 11 is fixed, and a drive mechanism 13 which is accommodated a valve shaft 12 to the driving chamber 8 so as to drive rotation.

  A fuel injection valve 14 for injecting fuel in the intake passage 6 downstream of the throttle valve 11 is attached to a body main portion 7a of the body 7, and a fuel pipe connected to the fuel injection valve 14 Reference numeral 15 denotes a screw member 16 which is attached to the body main portion 7a. An air cleaner 17 that is passed through the upstream end of the intake passage 6 is connected to the body main portion 7a.

  The housing portion 7b includes a cylindrical neck portion 7ba extending in the axial direction of the valve shaft 12 and connected to the body main portion 7a. The housing portion 7b projects sideways from the outer end of the neck portion 7ba. The cover 10 is composed of a box-shaped portion 7bb that is integrally connected to 7ba, and the cover 10 that closes the opening end of the box-shaped portion 7bb is fastened to the box-shaped portion 7bb.

  The drive mechanism 13 has a rotation axis parallel to the axis of the valve shaft 12 and is housed and fixed in the drive chamber 8, and is fixed to a motor shaft 21 of the electric motor 20. A drive gear 22, a first intermediate gear 23 meshed with the drive gear 22, a second intermediate gear 24 rotating with the first intermediate gear 23, and a second intermediate gear fixed to one end of the valve shaft 12 The rotational power of the electric motor 20 is decelerated and transmitted to the valve shaft 12.

  3 and 4, the ventilation hole 26 that allows the drive chamber 8 to be ventilated is a direction (in this embodiment, orthogonal to the plane PL including the central axis of the intake passage 6 and the axis of the valve shaft 12). The ventilation hole 26 is disposed within the projection plane line of the box-shaped portion 7bb in the direction along the axis of the valve shaft 12.

  The ventilation hole 26 is formed by a part of a cylindrical protrusion 30 that protrudes integrally with the neck portion 7ba, and the fuel pipe 15 connected to the fuel injection valve 14 connects the protrusion 30. It is arranged at a position covering from the outside.

  Further, a membrane material insertion hole 27 having a diameter larger than that of the ventilation hole 26 is disposed outside the ventilation hole 26 so as to be disposed within the projection plane line of the box-shaped portion 7bb in a direction along the axis of the valve shaft 12. In this embodiment, the membrane material insertion hole 27 is formed in the protrusion 30 so as to be coaxially connected to the outer end of the ventilation hole 26. Thus, the waterproof and breathable membrane material 31 is in contact with and adhered to the stepped portion 29 formed between the ventilation hole 26 and the membrane material insertion hole 27 while covering the ventilation hole 26. It is inserted into the film material insertion hole 27.

  Further, the membrane material insertion hole 27 is arranged such that a plug insertion hole 28 having a diameter larger than that of the membrane material insertion hole 27 is disposed within the projection plane line of the box-shaped portion 7bb in the direction along the axis of the valve shaft 12. In this embodiment, a plug insertion hole 28 is formed at the protruding end of the protrusion 30 so as to be coaxially connected to the outer end of the film material insertion hole 27. Is done. In addition, the plug 32 that closes the plug insertion hole 28 is fitted and fixed in the plug insertion hole 28.

  Moreover, an opening 33 that allows the film material insertion hole 27 between the plug 32 and the film material 30 to communicate with the outside is provided on the side wall of the plug insertion hole 28, and constitutes a part of the opening 33. A groove 34 is provided on the outer periphery of the protrusion 30 along its longitudinal direction.

  The groove 34 is provided on the outer periphery of the protrusion 30 so as to face the air cleaner 17, and is disposed at a position hidden by the air cleaner 17 when viewed from the air cleaner 17.

  Next, the operation of this embodiment will be described. The housing portion 7b that protrudes laterally from the cylindrical body main portion 7a that forms the intake passage 6 has a cylindrical neck portion 7ba and an outer portion of the neck portion 7ba. It consists of a box-like portion 7bb projecting laterally from the end, and the ventilation hole 26 is in a direction (in the present embodiment, a direction orthogonal) to the plane PL including the central axis of the intake passage 6 and the axis of the valve shaft 12. Since it is provided in the neck portion 7ba so as to extend, it is possible to simplify the mold structure when the body 7 is molded with the direction toward the plane PL (the direction orthogonal in this embodiment) as the mold dividing direction. it can. Further, the ventilation hole 26 is disposed in the projection plane line of the box-shaped portion 7bb in the direction along the axis of the valve shaft 12, so that the body 7 is prevented from being enlarged while ensuring a space for breathing, It is possible to prevent foreign matters such as mud from adhering to the ventilation hole 26 side. In addition, in this embodiment, since the protrusion 30 that forms the ventilation hole 26 is disposed at a position covered from the outside by the fuel pipe 15 connected to the fuel injection valve 14, mud or the like toward the ventilation hole 26 side is disposed. Can be more effectively prevented.

  Further, since the ventilation hole 26 is covered with the waterproof and breathable membrane material 31, ventilation can be performed while preventing water from entering the drive chamber 8 from the ventilation hole 26, and the membrane material 31 can be inserted. Since the membrane material insertion hole 27 continues to the outer end of the ventilation hole 26 and is disposed within the projection plane line of the box-like portion 7bb in the direction along the axis of the valve shaft 12, it prevents foreign matter from adhering to the membrane material 31. It is possible to avoid the increase in size of the body 7 while making it possible.

  In addition, since the plug insertion hole 28 closed by the plug 32 is connected to the outer end of the membrane material insertion hole 27, it is possible to more reliably prevent foreign matter such as mud from entering the membrane material 31, and the plug insertion hole 28. However, since it is disposed within the projection plane line of the box-shaped portion 7bb in the direction along the axis of the valve shaft 12, the body 7 is not enlarged by the installation of the plug 32. In addition, since the opening 33 that allows the film material insertion hole 27 between the plug 32 and the film material 31 to communicate with the outside is provided on the side walls of the film material insertion hole 27 and the plug insertion hole 28, the drive chamber 8 through the film material 31 is provided. Ventilation is possible, and the opening 33 can be easily formed. .

  A ventilation hole 26, a membrane material insertion hole 27, and a plug insertion hole 28 are provided coaxially on a cylindrical projection 30 projecting from the neck portion 7 ba, and a part of the opening 33 is formed on the projection 30. Since the groove 34 is formed on the outer periphery along the longitudinal direction, the opening 33 and the groove 34 can be easily formed, and the groove 34 can be formed relatively long. It is difficult to accumulate and the opening 33 is not blocked.

  Furthermore, since the groove 34 provided on the outer periphery of the protrusion 30 facing the air cleaner 17 side is hidden by the air cleaner 17 when viewed from the air cleaner 17 side, entry of foreign matters such as mud into the groove 34 and the opening 33 is suppressed. be able to.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

5 ... Throttle body 6 ... Intake passage 7 ... Body 7a ... Body main part 7b ... Housing part 7ba ... Neck part 7bb ... Box-like part 8 ... Drive chamber 10 ... Cover 11 ... Throttle valve 12 ... Valve shaft 13 ... Drive mechanism 17 ... Air cleaner 26 ... Ventilation hole 27 ... Membrane material insertion hole 28 ... Plug insertion hole 29 .... Step part 30 ... Projection part 31 ... Film material 32 ... Plug 33 ... Opening part 34 ... Groove PL ... Flat surface

Claims (5)

  A body (7) integrally having a cylindrical body main part (7a) forming an intake passage (6) and a housing part (7b) protruding laterally from the body main part (7a), and the housing part ( 7b), a drive chamber (8) is formed between the cover (10) attached to the housing part (7b) and the opening of the intake passage (6) can be changed, and the intake air can be changed. The throttle valve (11) disposed in the passage (6) and the body (7) are rotated so that one end thereof enters the drive chamber (8) while crossing the intake passage (6). A valve shaft (12) to be supported and fixed to the throttle valve (11), and a drive mechanism (8) accommodated in the drive chamber (8) to rotationally drive the valve shaft (12). 13), the throttle body comprising A cylindrical neck portion (7ba) that extends in the axial direction of the valve shaft (12) and is connected to the body main portion (7a), and an outer end of the neck portion (7ba) A ventilation hole (26) which is formed of a box-shaped portion (7bb) projecting laterally from the side and integrally connected to the neck portion (7ba), which allows ventilation of the drive chamber (8), is provided in the intake passage (6 ) In the plane of projection of the box-shaped portion (7bb) extending in a direction toward the plane (PL) including the central axis of the valve shaft (12) and the axis of the valve shaft (12) and along the axis of the valve shaft (12) The ventilation structure of the drive chamber in the throttle body, characterized in that it is provided on the neck portion (7ba) so as to be disposed at the bottom.   The membrane material insertion hole (27) having a diameter larger than that of the ventilation hole (26) is arranged in the projection plane line of the box-shaped portion (7bb) in the direction along the axis of the valve shaft (12). A stepped portion formed between the ventilation hole (26) and the membrane material insertion hole (27) is a membrane material (31) that is connected to the outer end of the ventilation hole (26) and has waterproof ventilation. 2. The drive chamber in the throttle body according to claim 1, wherein the drive chamber is inserted into the membrane material insertion hole (27) while covering the ventilation hole (26) by being in contact with and fixed to (29). Ventilation structure.   A plug insertion hole (28) having a diameter larger than that of the membrane material insertion hole (27) is disposed within a projection plane line of the box-shaped portion (7bb) in a direction along the axis of the valve shaft (12). Thus, the plug (32) connected to the outer end of the membrane material insertion hole (27) and closing the plug insertion hole (28) is inserted and fixed in the plug insertion hole (28), and the plug (32 ) And the membrane material insertion hole (27) between the membrane material (31) are provided on the side walls of the membrane material insertion hole (27) and the plug insertion hole (28). The ventilation structure of the drive chamber in the throttle body according to claim 2.   The ventilation hole (26), the membrane material insertion hole (27) and the plug insertion hole (28) are provided in a cylindrical projection (30) projecting from the neck portion (7ba), and the opening The throttle body according to claim 3, wherein a part of the part (33) is formed by a part of a groove (34) provided along the longitudinal direction of the outer periphery of the protrusion (30). Drive room ventilation structure.   The groove (34) is provided on the outer periphery of the protrusion (30) so as to face the air cleaner (17) connected to the body main part (7a) so as to pass through the upstream end of the intake passage (6). The ventilation structure of the drive chamber in the throttle body according to claim 4, wherein the air cleaner (17) is formed so as to hide the groove (34) when viewed from the air cleaner (17) side.

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