JP4519103B2 - Resin throttle body - Google Patents

Description

  The present invention relates to a resin throttle body attached to an internal combustion engine mounted on a vehicle or the like.

2. Description of the Related Art Conventionally, a throttle body attached to an engine which is an internal combustion engine mounted on, for example, a vehicle or an automobile has been widely used to reduce the weight. For example, Patent Document 1 describes a throttle body made of synthetic resin that is connected to an intake manifold made of synthetic resin. These intake manifolds and throttle bodies made of synthetic resin are generally manufactured by injection molding.
JP 2003-343289 A

  By the way, in the throttle body made of synthetic resin, as described in Patent Document 1, for example, the flange portion for mounting the throttle body is bent by contraction after molding, and the flatness of the mounting surface is lowered. There is. When such a throttle body is attached to the intake manifold, a portion of the throttle body in which the throttle valve is built, that is, the intake air metering portion may be deformed due to the flatness of the attachment surface. Such deformation of the intake air metering section in the throttle body may hinder accurate measurement of the intake air amount when the engine is in an idling operation state. In addition, the throttle valve may come into contact with the deformed inner wall of the intake air metering section, which may affect the operation of the throttle valve.

  In view of such problems, in Patent Document 1, the thickness of the wall between the flange portion and the intake air metering portion is set so that the stress distortion generated in the flange portion does not affect the intake air metering portion. Is made thinner than the thickness of the intake air metering section so that stress strain is not transmitted to the intake air metering section. Moreover, in this patent document 1, when connecting an air duct hose by the same structure, the stress distortion which arises in the attachment site | part of an air duct hose by tightening the metal band for retaining of an air duct hose is stress. Distortion is prevented from reaching the intake air metering section. In other words, the thickness of the air duct hose attachment portion and the wall between the attachment portion and the intake air metering portion is reduced to prevent stress strain from reaching the intake air metering portion.

  However, if the thickness of the mounting part of the air duct hose is reduced until the distortion caused by the tightening force by the metal band is not transmitted to the intake air metering part, the tightening force of the band is not uniform all around. As a result, the roundness of the air duct hose decreased, and the sealing performance between the inner periphery of the air duct hose and the outer periphery of the attachment portion decreased. As described above, when the sealing performance at the connecting portion of the air duct hose is lowered, the intake air or blowby gas leaks from the connecting portion, or the outside air that has not passed through the air cleaner flows into the throttle valve. This problem becomes prominent in a vehicle equipped with a turbocharger having a large band tightening force.

  Therefore, the present invention aims to eliminate such problems.

That is, the resin throttle body of the present invention is a resin including a cylinder having a mounting cylinder portion to which a hose member for guiding air is attached in close contact with the outer peripheral surface, and a throttle valve provided inside the cylinder. In the made throttle body, at least first and second annular thin walls that are thinner than the thickness of the mounting cylinder portion along the circumferential direction of the cylindrical body at a position downstream of the mounting cylinder portion and upstream of the throttle valve in the cylinder body part of providing, and said first and Ri Na provided thick a thick portion than the thickness of the mounting cylinder portion between the second thin annular portion, adjacent the first annular thin portion upstream from the thick portion Thus, a restraining rod for preventing movement of the hose member is formed between the first annular thin portion and the thick portion so as to protrude from the outer wall of the cylindrical body .
The first and second annular thin-walled portions are preferably annular grooves having tapered surfaces that are located downstream from the mounting cylinder portion and are inclined toward the intake air metering portion to which the throttle valve is attached.

According to such a configuration, when the hose member is attached by being in close contact with the outer peripheral surface of the mounting cylinder portion of the cylindrical body on the upstream side of the thick wall portion, the stress distortion is caused by each annular shape. It is blocked by the thin part. Therefore, stress distortion does not occur in the portion where the throttle valve is built in, and it is possible to prevent problems such as inaccurate metering of the intake air amount when operating with being attached to the internal combustion engine. . Further, by providing the thick portion between the annular thin portions, it is possible to prevent the strength of the portion upstream of the throttle valve from being extremely reduced. Further, the hose member is restrained by the restraining rod, so that the hose member can be easily positioned in the hose attachment portion.

  As described above, the present invention is in close contact with the outer peripheral surface of the mounting cylinder portion of the cylindrical body on the upstream side of the thick-walled portion without extremely reducing the strength of the portion upstream of the throttle valve. Even if the cylindrical body is distorted by being attached, the stress distortion can be prevented by the respective annular thin portions. For this reason, stress distortion does not occur in the part where the throttle valve is built in, and it is possible to prevent problems such as inaccurate metering of the intake air amount when operating with being attached to the internal combustion engine.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  The throttle body TH is made of synthetic resin and basically includes a cylinder 1 and a throttle valve 2 including a butterfly valve provided inside the cylinder 1. The cylindrical body 1 has a plurality of substantially cylindrical shapes having different inner diameters, and an air duct hose DH that is a hose member that guides intake air when attached to an engine that is an internal combustion engine is in close contact with the outer peripheral surface. Hose attachment part 11 having attachment cylinder part 11a for attachment, intake air metering part 12 to which throttle valve 2 is attached at a substantially intermediate position between one end part and the other end part, and attachment to the outer peripheral part A manifold attachment portion 14 having a flange 13 is provided. The hose attachment portion 11, the intake air metering portion 12, and the manifold attachment portion 14 are arranged in this order from upstream to downstream in the direction of intake air flow when attached to the engine.

The hose attachment portion 11 is formed on one end side of the cylindrical body 1, and includes an attachment cylinder portion 11a inserted into the air duct hose DH and an inclined portion 11b whose inner diameter decreases toward the intake air metering portion 12. And a first annular thin portion (hereinafter referred to as a first thin portion) 11c, a second annular thin portion (hereinafter referred to as a second thin portion) 11d, and a thick portion 11e. The mounting cylinder portion 11a of the hose mounting portion 11 has an inner diameter set in order to keep inflow of intake air well, and has an outer diameter that matches the inner diameter of the air duct hose DH. Is formed with an annular ridge 11f for preventing the air duct hose DH from coming off. The inclined portion 11b is a portion for adjusting a difference in inner diameter between the hose attachment portion 11 and the intake air metering portion 12.

The first thin part 11c, the second thin part 11d, and the thick part 11e are downstream of the attachment cylinder part 11a to which the air duct hose DH is attached and the intake air metering part 12 to which the throttle valve 2 is rotatably attached. It is formed at a predetermined portion of the hose attachment portion 11 on the upstream side. The first thin portion 11c is formed of an annular groove having a tapered surface inclined toward the intake air metering portion 12, and is a portion from the end portion where the annular protrusion 11f of the hose attachment portion 11 is provided to the first thin portion 11c. The thickness is smaller than the thickness of a certain mounting cylinder portion 11a, that is, it is thin. Adjacent to the first thin portion 11c and between the thick portion 11e, a restraining rod 11g for preventing the movement of the air duct hose DH is formed protruding from the outer wall of the hose attachment portion 11. When the air duct hose DH is connected to the hose attachment portion 11, the end of the air duct hose DH abuts against the restraining rod 11g.

  Similarly to the first thin portion 11c, the second thin portion 11d is formed to have a thickness smaller than the thickness of the mounting tube portion 11a, that is, a thin wall, and is a tapered surface inclined from the thick portion 11e toward the intake air metering portion 12. An annular groove having Adjacent to the second thin portion 11d, between the inclined portion 11b, a reinforcing rod 11h having a smaller projecting dimension than the stopping rod 11g is formed, similar to the blocking rod 11g. The thick part 11e formed between the first thin part 11c and the second thin part 11d is formed thicker than the thickness of the mounting cylinder part 11a of the hose mounting part 11, that is, thick.

  The throttle valve 2 is formed of a substantially circular plate and is attached to a throttle shaft 21 that penetrates the intake air metering portion 12. The throttle valve 2 adjusts the intake air amount by changing the opening area of the intake air metering section 12 based on the rotation angle of the throttle shaft 21. A throttle lever 22 is attached to one end of the throttle shaft 21 and the other end is connected to a throttle sensor 3 that detects the throttle opening. The throttle shaft 21 is urged by a coil spring 4 attached to the throttle lever 22 side in a direction in which the throttle valve 2 is closed when no rotational force is applied to the throttle lever 22.

  In such a configuration, the throttle body TH is attached to the intake manifold by the flange 13, for example, from the upper side of the engine, that is, with the central axis of the cylinder 1 aligned with the longitudinal direction of the engine. An air duct hose DH for introducing air from the air cleaner into the throttle body TH is connected to the throttle body TH integrated with the engine at the hose mounting portion 11 facing upward.

  The air duct hose DH is attached by fitting the attachment tube portion 11a of the hose attachment portion 11 into the air duct hose DH so that the attachment tube portion 11a of the hose attachment portion 11 is attached in close contact with the outside of the air duct hose. The air duct hose DH is tightened by a so-called hose band or hose clip HC. The mounting tube portion 11a of the hose mounting portion 11 is inserted into the air duct hose DH until the tip of the air duct hose DH abuts against the restraining rod 11g of the throttle body TH. Since the air duct hose DH is located above the throttle body TH, it falls downward when not tightened with the hose clip HC, but the restraining rod 11g restrains the fall. And the positioning of the air duct hose DH in the hose attachment part 11 can be facilitated by restraining the air duct hose DH by the restraining rod 11g.

  After the positioning of the air duct hose DH is completed, when the air duct hose DH is tightened by the hose clip HC, the tightening force causes stress distortion in the mounting tube portion 11a of the hose mounting portion 11, and the mounting tube portion 11a of the hose mounting portion 11 is It may be slightly deformed from a cylinder having a substantially circular cross-sectional shape. In this case, the first thin part 11c and the second thin part 11d provided between the attachment cylinder part 11a and the intake air metering part 12 prevent stress distortion generated in the attachment cylinder part 11a of the hose attachment part 11. . That is, the first thin wall portion 11c and the second thin wall portion 11d are different in thickness from the mounting tube portion 11a of the hose mounting portion 11, thereby preventing deformation due to the generated stress strain, and measuring the intake air while the stress strain remains as it is. It is not transmitted to the part 12. Moreover, the stress strain reduced by the first thin portion 11c is further reduced by the second thin portion 11d after the amount of distortion deformation is reduced due to the rigidity of the thick portion 11e.

  As described above, since the thin portion, that is, the first thin portion 11c and the second thin portion 11d, which are thinner than the mounting cylinder portion 11a, are provided in two stages along the flow direction of the intake air, the stress strain is greatly reduced. Thus, deformation of the intake air metering unit 12 can be reliably suppressed. Therefore, when the throttle valve 2 is closed, for example, when the throttle valve 2 is closed to the idle opening, the distance between the throttle valve 2 and the inner peripheral surface of the intake air metering unit 12 due to the deformation of the intake air metering unit 112. Therefore, it is possible to prevent such a problem that the intake air amount is inaccurately measured. Further, such a deformation can also prevent the trouble that the throttle valve 2 is restricted by the inner peripheral surface of the intake air metering portion 12 and cannot be rotated.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

The front view of the embodiment of the present invention. The side view of the embodiment. Sectional drawing along the II line | wire of the embodiment. Sectional drawing along the II-II line of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cylindrical body 2 ... Throttle valve 11a ... Mounting cylinder part 11c ... 1st thin part 11d ... 2nd thin part 11e ... Thick part DH ... Air duct hose

Claims (2)

In a resin throttle body comprising a cylinder having an attachment cylinder portion to which a hose member for guiding air is attached in close contact with the outer peripheral surface, and a throttle valve provided inside the cylinder,
Provide at least first and second annular thin portions that are thinner than the thickness of the mounting cylinder portion along the circumferential direction of the cylinder at a site downstream of the mounting cylinder portion and upstream of the throttle valve in the cylinder; and Ri Na provided thick a thick portion than the thickness of the mounting cylinder portion between said first and second annular thin portion
Adjacent to the first annular thin portion upstream of the thick portion, a restraining rod that prevents the hose member from moving protrudes from the outer wall of the cylindrical body between the first annular thin portion and the thick portion. Plastic throttle body is formed . 2. The resin throttle according to claim 1, wherein the first and second annular thin portions are annular grooves each having a tapered surface that is located downstream from the attachment cylinder portion and is inclined toward an intake air metering portion to which a throttle valve is attached. body.

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