JP2010106738A - Throttle device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the idle speed of an internal combustion engine, by reducing the minimal air flow rate of an intake throttle valve control device for an internal combustion engine. <P>SOLUTION: Lip seals 7A, 7B as resin sealing members with good sealability are installed to body shaft holes 1A, 1B to reduce an amount of air leaked from the body shaft hole parts 1A, 1B and a valve slit 8, and thereby to reduce the minimal air flow rate taken into the internal combustion engine. Since sealing work is done at the same time as installation work of the throttle valve, the work is easily done compared with the coating of molybdenum disulfide to close a leaking air passage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a throttle device for controlling an opening area of an intake passage of an internal combustion engine to control an intake amount and a negative pressure of the intake passage, and in particular, is attached to a throttle shaft, and the throttle shaft is installed in the intake passage. And a butterfly-type throttle valve that rotates in an intake passage.

  In the conventional throttle device known from Japanese Patent Application Laid-Open No. 2004-27925, in order to reduce the amount of air leakage, molybdenum disulfide is applied to the intake passage side of both bearings of the throttle shaft, or the shaft hole diameter of the throttle shaft. Is made smaller.

JP 2004-27925 A

  In the above prior art, the molybdenum disulfide coating step increases and the manufacturing cost increases. Furthermore, if the body shaft hole diameter is reduced too much, there is a problem that it interferes with the throttle shaft and causes malfunction of the throttle valve.

  An object of the present invention is to reduce an air flow leaking from a gap between a bearing and a rotation locus on the outer periphery of a throttle valve in an intake air flow control device using a throttle valve for controlling an intake air flow rate or pressure of an internal combustion engine. This is achieved by reducing the air flow rate when the throttle valve is low.

  In the present invention, in order to achieve the above object, a three-part for sealing is mounted between the bearing and the rotation locus on the outer periphery of the throttle valve.

  Preferably, the sealing sleeve is formed integrally with the throttle shaft and the throttle valve, and is installed in the gap between the bearing and the rotation locus on the outer periphery of the throttle valve.

  By inserting the sealing sleeve into the shaft hole, the leakage air flow rate at the time of low valve opening can be reduced. As a result, the minimum air flow rate can be reduced, so that the engine idling speed can be lowered. Since the sealing operation can be achieved simultaneously with the throttle valve mounting operation, the operation is simpler than applying molybdenum disulfide and closing the leakage air passage.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an example in which a throttle valve according to a first example of an embodiment of the present invention is applied to a motor-driven intake throttle valve control device for a gasoline engine, and the configuration of components will be specifically described with reference to FIG. .

  FIG. 1 is a main sectional view thereof. In the following description, portions not shown in FIG. 1 are shown in detail in other FIGS.

  The throttle control device includes a bore 1 that forms a part of an intake passage of an internal combustion engine, and a throttle valve 2 that is rotatably mounted in the bore 1.

  The throttle valve 2 is fixed to the throttle shaft 3 with throttle valve retaining screws 3A and 3B. The throttle shaft 3 passes through the body shaft hole portions 1A and 1B of the bore 1, and the throttle in which the bore 1 is formed. The body 4 is rotatably supported.

  The apparatus of this embodiment includes ball bearing type bearings 5A and 6A in which bearing outer rings 5a and 6a are press-fitted into bearing mounting bosses 5 and 6 of the throttle body 4, and the throttle shaft 3 includes the bearings 5A and 5A. The throttle shaft 3 is press-fitted into the bearing inner rings 5b and 6b of 6A and is rotatably supported by the throttle body 4.

  Due to recent environmental problems, there is a problem of reducing exhaust gas discharged from vehicles. One of the means for reducing the exhaust gas is to improve the fuel efficiency. As a demand for the throttle from the improvement of the fuel efficiency, there is a problem of reducing the minimum air flow rate in order to reduce the engine speed.

  The clearance between the body shaft hole portions 1A and 1B of the bore 1 and the throttle shaft 3 is set to have a very small clearance in order to suppress the flow rate of air flowing in the bore as much as possible. As a result, the flow rate of air flowing into the bore 1 is prevented from flowing in large amounts downstream through the bearing mounting bosses 5 and 6.

  However, if the clearance between the body shaft hole portions 1A, 1B of the bore 1 and the throttle shaft 3 is small, the body shaft hole portions 1A, 1B of the bore 1 and the throttle shaft 3 cause a galling phenomenon, and the operation is performed via the throttle shaft 3. Thus, the throttle valve 2 becomes immobile, and the function of the throttle control device is impaired.

  Therefore, as a structure for preventing the flow rate of air flowing into the downstream side of the throttle valve 2 through the bore 1, a lip seal 7A as a seal member is installed on an inner diameter portion coaxially penetrated with the body shaft hole portion 1A, and used as a seal member. The lip seal 7B is installed in an inner diameter portion that is coaxially penetrated with the body shaft hole portion 1B.

  By arranging the lip seals 7A and 7B as seal members in the body shaft hole portions 1A and 1B, air flowing out to the body shaft hole portions 1A and 1B can be prevented in advance, and as a result, the minimum air sucked into the engine The flow rate can be reduced.

  Lip seals 7A and 7B as seal members have a low coefficient of friction and excellent wear resistance and slidability so as not to increase resistance to the sliding portions with the body shaft hole portions 1A and 1B. For example, polyamide A resin member such as (PA), polyphenylene sulfide (PPS), or a fluorine resin is used.

  Further, the seal member can be integrally molded so as to cover the valve slit 8 of the throttle shaft 3, thereby suppressing the flow rate of the throttle leak from the valve slit 8.

  When the throttle shaft 3 is inserted and assembled from the left side of FIG. 1, the throttle shaft 3 is set by setting the outer diameter of the lip seal 7A as the seal member to be smaller than the outer diameter of the lip seal 7B as the seal member. Assembling workability to the throttle body 4 can be improved. On the other hand, when assembling from the opposite side, the outer diameter of the lip seal 7B as the seal member may be set smaller than the outer diameter of the lip seal 7A as the seal member.

  FIG. 4 is a schematic perspective view of a throttle shaft portion set integrally formed with a throttle shaft in an electronically controlled throttle device to which an intake throttle valve control device for an internal combustion engine according to a second embodiment of the present invention is applied. It is a schematic perspective enlarged view of lip seal installation in an electronically controlled throttle device to which an intake throttle valve control device for an internal combustion engine according to Embodiment 2 of the present invention is applied.

  In this embodiment, when the lip seals 7A and 7B as seal members for integral molding are formed so as to sandwich the throttle valve 2, the lip seals 7A and 7B as seal members rotate at the same time. In addition, the structure is made difficult to slip. As a result, it is possible to make a structure that improves the mutual adhesion at a lower cost than by performing an additional process of uneven shape on the throttle shaft 3 side and improving the adhesion at the time of molding with the lip seals 7A and 7B as the seal members. be able to.

  Further, the lip seals 7A and 8A as seal members that protrude into the bore may be shaped to be chamfered so as not to cause a pressure loss of the air flowing into the bore when the throttle valve 2 is at a high opening degree. .

  In the embodiment, a single bore has been described, but it can also be applied to a multiple throttle having a plurality of bores, and further to an electronically controlled throttle.

1 is a cross-sectional view of a motor-driven throttle valve control device used in a vehicle according to Embodiment 1 of the present invention. 1 is an enlarged view of installation of a seal member in an electronically controlled throttle device to which an intake throttle valve control device for an internal combustion engine according to Embodiment 1 of the present invention is applied. 1 is a schematic perspective view of a throttle shaft portion set integrally formed with a throttle shaft in an electronically controlled throttle device to which an intake throttle valve control device for an internal combustion engine according to Embodiment 1 of the present invention is applied. FIG. 7 is a schematic perspective view of a throttle shaft portion set integrally formed with a throttle shaft in an electronically controlled throttle device to which an intake throttle valve control device for an internal combustion engine according to Embodiment 2 of the present invention is applied. The schematic perspective enlarged view of the lip seal installation in the electronically controlled throttle device to which the intake throttle valve control device for an internal combustion engine according to the second embodiment of the present invention is applied.

Explanation of symbols

1 Bore 1A, 1B Body shaft hole 2 Throttle valve 3 Throttle shaft 3A, 3B Throttle valve retaining screw 4 Throttle body 5, 6 Bearing mounting boss 5A, 6A Bearing 5a, 6a Bearing outer ring 5b, 6b Bearing inner ring 7A, 7B Lip seal 8 as a seal member Valve slit

Claims (5)

A throttle body with an intake passage,
A throttle shaft disposed across the intake passage and rotatably supported by the throttle body;
In the throttle shaft provided with the butterfly throttle valve that rotates with the throttle shaft and controls the passage area of the intake passage.
The throttle body has a bearing hole through which the throttle shaft is inserted,
A bearing is attached to the bearing hole,
Further, the throttle shaft is inserted into the bearing,
An end surface on the intake passage side of the bearing and an outer peripheral surface of the butterfly throttle valve are installed between a rotation locus, an inner periphery thereof is in contact with an outer peripheral surface of the throttle shaft, and the outer peripheral surface is an inner surface of the bearing hole. A throttle device for an internal combustion engine provided with a sealing sleeve in contact with a peripheral surface. In claim 1,
A throttle valve control device for an internal combustion engine, wherein the sealing sleeve is integrally formed with a throttle shaft and a throttle valve. In claim 1,
The throttle device for an internal combustion engine, wherein the sealing sleeve is made of a resin material. In claim 1,
The throttle shaft has a slit into which the butterfly throttle valve is inserted at the center,
A throttle device for an internal combustion engine, wherein the sealing sleeve covers the throttle valve insertion valve slit of the throttle shaft. In claim 1,
A pair of the bearings are provided on both sides of the throttle shaft across the intake passage,
The throttle device for an internal combustion engine, wherein one outer diameter of the two sealing sleeves is smaller than the other outer diameter.

Images