intake throttle valve

Abstract

This invention relates to an intake throttle valve, which provides a thrust movement limiting structure for a shaft with fewer components and lower cost. One embodiment is an intake throttle valve (10) comprising a throttle body (12), a throttle valve member (15), a throttle shaft (17), a needle roller bearing (32) supporting the throttle shaft for rotation, a throttle gear (20) driven by an electric actuator, and a mounting member (50) fixed to the throttle gear. The outer ring (33) of the needle roller bearing is fixed to the throttle body. The throttle shaft and the mounting member have limiting surfaces (17c, 52a) facing each other across the needle roller bearing (32), with a gap between at least one of the limiting surfaces and the needle roller bearing. The axial movement of the throttle shaft is limited by the needle roller bearing abutting against either of the limiting surfaces.

Description

Technical Field

[0001] The technology disclosed in this application relates to intake throttle valves. Background Technology

[0002] Vehicles equipped with engines, such as cars, motorcycles, powered bicycles, and ships, typically have an intake throttle valve (throttle body) that controls the amount of air intake to the engine. The intake throttle valve usually uses an electric motor to rotate a shaft fixed to the throttle valve assembly (disc) to open and close the intake passage formed in the main body. The rotation of the electric motor is transmitted to the shaft via a gear train, with the final gear, called the throttle gear, fixed to the shaft. The shaft is supported by bearings to allow it to rotate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-150971 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The intake throttle valve disclosed in Japanese Patent Application Publication No. 2008-150971 discloses a method in which a rod controlling the opening and closing of a throttle valve component is reliably fixed to the shaft while the shaft is supported by a bearing to allow rotation. However, this intake throttle valve is not electric and does not have a throttle gear. Even assuming that a throttle gear is mounted on the rod in this publication, the structure is relatively complex because the thrust movement of the shaft is limited using a collar or cup-shaped component. Therefore, a structure that limits the thrust movement of the shaft with fewer components and at low cost is desired.

[0008] Solution for solving the problem

[0009] One technical solution of this technology is an intake throttle valve, which comprises: a throttle body forming a fluid passage; a throttle valve member disposed in the fluid passage for opening and closing the fluid passage; a throttle shaft fixed to the throttle valve member; a needle roller bearing supporting the throttle shaft for rotation; a throttle gear driven by an electric actuator; and a mounting member fixed to the throttle gear. The outer ring of the needle roller bearing is fixed to the throttle body. The throttle shaft and the mounting member have opposing limiting surfaces separated by the needle roller bearing. At least one of the limiting surfaces of the throttle shaft and the needle roller bearing, and the limiting surface of the mounting member and the needle roller bearing, has a gap. The needle roller bearing abuts against either the limiting surface of the throttle shaft or the limiting surface of the mounting member, thereby limiting the axial movement of the throttle shaft. Thus, the thrust movement of the shaft can be limited with a structure containing fewer components and at a lower cost. This restriction can suppress wear and tear on the throttle body and throttle valve components, as well as valve component locking and other adverse conditions. Attached Figure Description

[0010] Figure 1 This is a cross-sectional view of an intake throttle valve as one implementation.

[0011] Figure 2 yes Figure 1 A magnified view of the portion of the intake throttle valve enclosed by the dotted line.

[0012] Explanation of reference numerals in the attached figures

[0013] 10. Intake throttle valve; 12. Throttle body; 12a. Housing; 12b. Cover; 13. Fluid passage; 15. Throttle valve component; 17. Throttle shaft; 17a. Top; 17c. Restricting surface; 17b. Welded part; 20. Throttle gear; 20a. Through part; 20b. Inner wall surface; 22. Motor; 24. Drive gear; 26. Intermediate gear; 26a. Large diameter tooth; 26b. Small diameter tooth; 28. Tooth; 30. Helical spring; 32. (Needle roller) bearing; 33. Outer ring; 35. Needle roller; 45. Bearing retainer; 45a. Wall surface; 45b. Bottom surface; 50. Mounting component; 51. Base; 51a. Outer periphery; 51b. Inner periphery; 51c. Surface; 52. Cylindrical part; 52a. Restricting surface. Detailed Implementation

[0014] Hereinafter, various embodiments of the present technology will be described with reference to the accompanying drawings.

[0015] [Intake throttle valve]

[0016] Figure 1This describes an intake throttle valve 10, as one embodiment, installed in vehicles such as automobiles and motorcycles to regulate the amount of air intake into the engine. The intake throttle valve 10 includes a throttle body 12 forming a through-flow fluid passage 13. The fluid passage 13 constitutes a portion of the intake passage leading to the engine. The throttle body 12 can be made of metal or resin. Furthermore, the intake throttle valve 10 includes a rotatable circular throttle valve member (disc) 15 that regulates the flow rate through the fluid passage 13. The throttle valve member 15 is fixed to a throttle shaft 17, which is rotatably supported on the throttle body 12. The throttle valve member 15 passes through a slit in the throttle shaft 17 and is fixed to the throttle shaft 17 by means of threaded components or the like. The throttle shaft 17 is arranged to traverse the fluid passage 13 in the diametrical direction and is supported on both sides of the fluid passage 13 by bearings 32, 19 mounted on the throttle body 12. The throttle valve assembly 15 is rotatable from a fully closed position, which is substantially orthogonal to the fluid passage 13, to a fully open position, which is substantially parallel to the fluid passage 13. The throttle valve assembly 15 opens and closes when the throttle shaft 17 rotates. The throttle shaft 17 can be made of metal.

[0017] [Motor and transmission mechanism]

[0018] The intake throttle valve 10 includes a motor 22 as an electric actuator for driving the throttle valve component 15. The rotation output from the motor 22 is transmitted to the throttle shaft 17 via a transmission mechanism. The motor 22 and the transmission mechanism are housed in a housing portion 12a formed in the throttle body 12, and the throttle body 12 has a cover 12b that closes the housing portion. In one embodiment, the transmission mechanism includes a drive gear 24 fixed to the output shaft of the motor 22, an intermediate gear 26 rotatably supported on the throttle body 12 by means of an intermediate shaft, and a throttle gear 20 coaxially fixed to the throttle shaft 17 as a driven gear. The intermediate gear 26 has a large-diameter tooth portion 26a and a small-diameter tooth portion 26b coaxially fixed to the intermediate shaft. The drive gear 24 meshes in the large-diameter tooth portion 26a, and the teeth 28 of the throttle gear 20 mesh in the small-diameter tooth portion 26b. The throttle gear 20 can be made of resin. Throttle shaft 17 is fixed to throttle gear 20 by means of mounting member 50, also referred to as rod (described later). Motor 22 is controlled by an external electronic control unit (ECU). The opening of throttle valve member 15 is adjusted by controlling the rotation direction and amount of rotation of motor 22.

[0019] [coil spring]

[0020] The intake throttle valve 10 includes a coil spring 30, which functions as a torsion spring that applies force to the throttle valve member 15 toward its default position. One end of the coil spring 30 is mounted to the throttle body 12, and the other end is mounted to the throttle gear 20, through which a force is applied to the throttle valve member 15. When the motor 22 is energized (i.e., when the output shaft can be controlled), the force of the coil spring 30 can overcome the force of the coil spring 30, causing the throttle valve member 15 to rotate to any position between the fully closed and fully open positions. When the power to the motor 22 is cut off, the force of the coil spring 30 causes the throttle valve member 15 to automatically rotate to its default position, supplying a certain amount of air to the engine via the fluid passage 13.

[0021] Needle roller bearings

[0022] like Figure 2 As shown, the bearing 32 on the throttle gear 20 side is a needle roller bearing. The needle roller bearing 32 has an outer ring 33 and a plurality of needle rollers 35 rolling inside the outer ring 33. The throttle body 12 has a bearing retainer 45. The bearing retainer 45 has a cylindrical wall 45a on its inner side, which holds the outer ring 33 of the bearing 32 in an interference fit. The bearing 32 can be axially positioned using the bottom surface 45b of the bearing retainer 45. The bearing retainer 45 can, for example, be configured as a cylindrical body protruding from the throttle body 12 toward the throttle gear 20. Figure 1 One end of the helical spring 30 is disposed on the outside of the cylindrical body constituting the bearing retainer 45. As another embodiment not shown, a needle roller bearing that also has an inner ring and in which needle rollers roll between the outer and inner rings can also be used.

[0023] [Installation Components]

[0024] The throttle shaft 17 is fixed to the throttle gear 20 by means of a generally annular mounting member 50. The throttle gear 20 has a through portion 20a or a recess that receives the top end 17a of the throttle shaft 17. The mounting member 50 can be made of metal and can be partially embedded in the inner wall surface 20b of the resin-made through portion 20a of the throttle gear 20 by insert molding, thereby engaging with the throttle gear 20. The throttle gear 20 is engaged with the throttle shaft 17 by welding the top end 17a of the throttle shaft 17 relative to the mounting member 50 (e.g., by laser welding). Figure 2 The welded part 17b is shown as an example.

[0025] [Restricted aspects]

[0026] The throttle shaft 17 and the mounting member 50 have opposing limiting surfaces 17c and 52a separated by a needle roller bearing 32. The distance between the limiting surface 17c of the throttle shaft 17 and the limiting surface 52a of the mounting member 50 is set to a size that does not simultaneously abut against the needle roller bearing 32. That is, a gap exists between at least one of the limiting surface 17c of the throttle shaft 17 and the needle roller bearing 32, and between the limiting surface 52a of the mounting member 50 and the needle roller bearing 32. However, the axial movement (thrust movement) of the throttle shaft 17 is limited by the needle roller bearing 32 abutting against either the limiting surfaces 17c or 52a of the throttle shaft 17 and the mounting member 50. Therefore, thrust movement of the throttle shaft 17 can be limited without the need for special additional components such as a C-ring arranged around the throttle shaft 17, thus reducing costs.

[0027] As one embodiment, the limiting surface 17c of the throttle shaft 17 described above can be set as a stepped surface facing the needle roller bearing 32 on the throttle shaft 17.

[0028] The mounting member 50, for example, has a base 51 that engages with the throttle gear 20 and a cylindrical portion 52 extending from the base 51 toward the needle roller bearing 32. The base 51 can be flat, with its outer periphery 51a embedded in the throttle gear 20. As one embodiment, the top end 17a of the throttle shaft 17 can be welded to the inner periphery 51b of the surface 51c of the base 51 of the mounting member 50 on the side farther from the needle roller bearing 32. The welding can be performed continuously around the entire circumference of the inner periphery 51b, or it can be performed discontinuously (e.g., in dots) at multiple locations along the inner periphery 51b. As one embodiment, the limiting surface 52a of the mounting member 50 can be the top end surface of the cylindrical portion 52 facing the needle roller bearing 32.

[0029] In one embodiment, the mounting member 50 can have an L-shaped cross-section. That is, the inner periphery 51b of the base 51 is made circular, and the cylindrical portion 52 extends from the inner periphery 51b of the base 51 toward the needle roller bearing 32. Thus, the mounting member 50 becomes a simple drawn shape, making molding easier. In another embodiment (not shown), the mounting member 50 can also have a T-shaped cross-section. That is, the cylindrical portion 52 extends from the portion of the base 51 that is outside the inner periphery 51b toward the needle roller bearing 32. In yet another embodiment (not shown), the cylindrical portion 52 of the mounting member 50 can also have a trapezoidal cross-section. That is, the diameter can be made to thicken from the top surface (limiting surface 52a) toward the base 51.

[0030] [Assembly]

[0031] During assembly, firstly, the throttle body shaft 17 is inserted into the through hole of the throttle body 12, and the needle roller bearing 32 is inserted into the top end 17a of the throttle body shaft 17, while simultaneously pressing the outer ring 33 into the bearing retainer 45. The throttle gear 20, with the mounting member 50 embedded within it, is then inserted into the top end 17a of the throttle body shaft 17, and the top end 17a is welded relative to the mounting member 50. Next, the throttle valve component 15 is inserted into the slit of the throttle body shaft 17 and secured with threads.

[0032] The above describes the specific implementation methods, but this technology is not limited to these implementation methods. If one is skilled in the art, one can implement various substitutions, improvements and changes without departing from the purpose of this technology.

Claims

1. An intake throttle valve, wherein, This intake throttle valve features: The throttle body forms the fluid passage; A throttle valve component, which is disposed in the fluid passage, to open and close the fluid passage; Throttle valve shaft, which is fixed to the throttle valve component; A needle roller bearing that supports the throttle body shaft so that it can rotate; Throttle gear, which is driven to rotate by an electric actuator; as well as The mounting component is fixed to the throttle gear. The outer ring of the needle roller bearing is fixed to the throttle body. The throttle body shaft and the mounting member have opposing limiting surfaces separated by the needle roller bearing, and at least one of the limiting surface of the throttle body shaft and the needle roller bearing and the limiting surface of the mounting member and the needle roller bearing has a gap. The axial movement of the throttle shaft is restricted by the needle roller bearing abutting against either the limiting surface of the throttle shaft or the limiting surface of the mounting member.

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