Intake control valve

Abstract

To suppress misalignment of a throttle valve to a throttle shaft after fastening using a tightening member.SOLUTION: An intake control valve 10 comprises a throttle shaft 20 having a slit 21, a throttle valve 30 inserted into the slit 21, and a screw 40 fastening the throttle valve 30 to the throttle shaft 20. The slit 21 has two wall surfaces 21a that make surface contact with two plate surfaces 31 of the throttle valve 30. The two plate surfaces 31 of the throttle valve 30 have contact surface parts 31a that make surface contact with the wall surfaces 21a and non-contact surface parts 31b that do not make surface contact with the wall surfaces 21a. The wall surfaces 21a have a shaft-side rough surface part that has a rougher surface roughness than an outer peripheral surface 20b of the throttle shaft 20. The contact surface parts 31a have a valve-side rough surface part that has a rougher surface roughness than the non-contact surface parts 31b.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to an intake control valve. [Background technology]

[0002] A conventional valve device is disclosed in, for example, Patent Document 1. The valve device includes a shaft having a slit hole penetrating in the radial direction, a flat valve inserted into the slit hole, and a fastening member that fastens the valve to the shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-172544 Summary of the Invention [Problem to be solved by the invention]

[0004] In the valve gear of Patent Document 1, in order to strengthen the connection between the shaft and the valve and prevent the valve from shifting due to stress caused by changes in the operating environment, uneven means (projections, recesses, etc.) are formed in the overlapping area where the shaft and the valve face each other. The uneven means (projections, recesses, etc.) bite into the mating part when the screw is tightened. However, forming the uneven means (projections, recesses, etc.) is difficult, making it difficult to reduce cost. In addition, there is a large variation in the degree to which the projections (projections) bite into the mating part, which can make the valve's prevention of shifting unstable. In addition, the projections can also reduce the ease of assembly to the mating part.

[0005] The problem that the technology disclosed in this specification aims to solve is to suppress misalignment of the throttle valve with respect to the throttle shaft after fastening by the fastening member, by using a configuration different from the configuration described in Patent Document 1. [Means for solving the problem]

[0006] In order to solve the above problems, the technology disclosed in this specification takes the following measures.

[0007] The first means is an intake control valve comprising a throttle shaft having a slit hole penetrating in the radial direction, a flat throttle valve inserted into the slit hole, and a fastening member fastening the throttle valve to the throttle shaft, wherein, in a fastened state between the throttle valve and the throttle valve, the slit hole of the throttle shaft has two wall surfaces that come into surface contact with both plate surfaces of the throttle valve, the two plate surfaces of the throttle valve have contact surface portions that come into surface contact with the two wall surfaces and non-contact surface portions that do not come into surface contact with the two wall surfaces, and at least one of the two wall surfaces of the slit hole has a shaft-side rough surface portion that has a surface roughness that is rougher than the outer peripheral surface of the throttle shaft, and / or the contact surface portion of at least one of the two plate surfaces of the throttle valve has a valve-side rough surface portion that has a surface roughness that is rougher than the non-contact surface portion of the plate surface.

[0008] According to the first aspect, the shaft-side rough surface portion and / or the valve-side rough surface portion increase the coefficient of friction between the contact surfaces of the throttle shaft and the throttle valve, thereby increasing the slippage load (retention force) of the throttle valve, thereby suppressing slippage of the throttle valve relative to the throttle shaft after fastening with the fastening member. [Effects of the Invention]

[0009] According to the technology disclosed in this specification, by using a configuration different from that described in Patent Document 1, it is possible to suppress deviation of the throttle valve relative to the throttle shaft after fastening by the fastening member. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a plan view showing an intake control valve according to one embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along the line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment for implementing the technology disclosed in this specification will be described below with reference to the drawings. In this embodiment, an intake control valve that controls the amount of intake air taken into an internal combustion engine (engine) is illustrated. FIG. 1 is a plan view showing the intake control valve, FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. For convenience of explanation, the front, rear, left, and right directions are determined based on the plan view in FIG. 1, but this does not specify the arrangement direction of the intake control valve.

[0012] (Outline of intake control valve) As shown in Figure 1, the intake control valve 10 has a throttle body 11. The throttle body 11 has a hollow cylindrical bore 12 that extends straight up and down (into and out of the plane of the paper in Figure 1). Intake air flowing from the air cleaner side flows through the bore 12 toward the intake manifold side. The throttle body 11 is made of resin or metal.

[0013] As shown in FIG. 2, a round rod-shaped throttle shaft 20 that crosses the bore 12 in the left-right direction (radial direction) is rotatably supported in the throttle body 11. The throttle shaft 20 has a slit hole 21 that penetrates in the radial direction (the front-to-back direction of the paper in FIG. 2). A flat throttle valve 30 is inserted into the slit hole 21. The throttle valve 30 has front and back surfaces (both plate surfaces) that are perfect circular or nearly perfect circular. The throttle valve 30 is fastened and fixed to the throttle shaft 20 by a screw 40. The throttle valve 30 rotates integrally with the throttle shaft 20 to control the amount of intake air flowing through the bore 12. The throttle shaft 20, throttle valve 30, and screw 40 are made of metal.

[0014] (Mounting structure of throttle valve 30 to throttle shaft 20) As shown in Figure 2, the longitudinal length of the slit 21 in the throttle shaft 20 is greater than the diameter 30d of the throttle valve 30. The lateral width of the slit 21 is slightly greater than the plate thickness 30t of the throttle valve 30. The slit 21 has two wall surfaces 21a that are flat surfaces parallel to each other in the lateral direction. A pair of left and right screw mounting holes 22 that are perpendicular to the slit 21 are formed in the throttle shaft 20.

[0015] As shown in Figure 3, the throttle valve 30 has two plate surfaces 31 which are flat surfaces parallel to each other. When the throttle valve 30 is inserted into the slit hole 21, the two plate surfaces 31 face both wall surfaces 21a of the slit hole 21 with almost no gap between them. The throttle valve 30 is formed with a pair of left and right screw insertion holes 32 which correspond to the two screw mounting holes 22 of the throttle shaft 20 (see Figure 2).

[0016] The screw 40 is a cross-recessed countersunk head screw. The screw 40 has a head 41 and a threaded shank 42. The screw 40 corresponds to the "fastening member" referred to in this specification. The screw mounting hole 22 of the throttle shaft 20 consists of a screw insertion hole 22a formed in the wall 20a on one side (upper side in FIG. 3) of the slit hole 21, and an internally threaded hole 22b formed in the wall 20a on the other side of the slit hole 21. The screw insertion hole 22a has a diameter slightly larger than the axial diameter of the threaded shank 42 of the screw 40. A countersunk hole 22c corresponding to the head 41 of the screw 40 is formed in the outer end (upper end in FIG. 3) of the screw insertion hole 22a. The threaded shank 42 of the screw 40 can be screwed into the internally threaded hole 22b. The screw insertion hole 32 of the throttle valve 30 has a hole diameter larger than the shaft diameter of the threaded shaft portion 42 of the screw 40 .

[0017] (Procedure for installing the throttle valve 30 on the throttle shaft 20) After the throttle shaft 20 is rotatably supported by the throttle body 11, the throttle valve 30 is inserted into the slit hole 21 of the throttle shaft 20. Next, the threaded shank 42 of the screw 40 is loosely inserted into the screw insertion hole 22a of the throttle shaft 20 and the screw insertion hole 32 of the throttle valve 30, and then tightened into the female threaded hole 22b. This fastens and fixes the throttle valve 30 to the throttle shaft 20. In this fastened state, both wall surfaces 21a of the slit hole 21 come into surface contact with both plate surfaces 31 of the throttle valve 30 due to deformation of both wall portions 20a and / or one of the wall portions 20a. Furthermore, because there is a radial gap between the screw insertion hole 32 of the throttle valve 30 and the threaded shank 42 of the screw 40, the throttle valve 30 may become misaligned due to stress caused by changes in the operating environment. This embodiment suppresses misalignment of the throttle valve 30 by the following characteristic configuration.

[0018] (Characteristic configuration of this embodiment) 3, when the throttle shaft 20 and the throttle valve 30 are fastened together, both wall surfaces 21a of the slit hole 21 of the throttle shaft 20 have shaft-side rough surface portions that have a rougher surface roughness (arithmetic mean roughness Ra) than the outer circumferential surface 20b of the throttle shaft 20. In this embodiment, the wall surfaces 21a are entirely shaft-side rough surface portions, and therefore the wall surfaces 21a are also referred to as shaft-side rough surface portions 21a.

[0019] Both plate surfaces 31 of the throttle valve 30 have contact surface portions 31a that come into surface contact with both wall surfaces 21a of the slit hole 21, and non-contact surface portions 31b that do not come into surface contact with either wall surface 21a. The contact surface portions 31a of both plate surfaces 31 have valve-side rough surface portions that have a rougher surface roughness (arithmetic mean roughness Ra) than the non-contact surface portions 31b of the plate surfaces 31. In this embodiment, since the entire contact surface portions 31a are valve-side rough surface portions, the contact surface portions 31a are also referred to as valve-side rough surface portions 31a.

[0020] (Advantages of the characteristic configuration of this embodiment) According to this embodiment, the shaft-side rough surface portion 21a and the valve-side rough surface portion 31a increase the coefficient of friction between the contact surfaces of the throttle shaft 20 and the throttle valve 30, thereby increasing the slippage load (retention force) of the throttle valve 30. This makes it possible to suppress slippage of the throttle valve 30 relative to the throttle shaft 20 after fastening with the screw 40. Furthermore, unlike the uneven means (projections, recesses, etc.) that bite into the mating surface of Patent Document 1, the shaft-side rough surface portion 21a and the valve-side rough surface portion 31a are easy to form, reducing costs and eliminating problems caused by protrusions (projections).

[0021] [Other embodiments] The technology disclosed in this specification is not limited to the above-described embodiment and can be implemented in various other forms. For example, the throttle shaft 20 may have a shaft-side rough surface portion on at least one of the wall surfaces 21a of the slit hole 21. The shaft-side rough surface portion 21a need not be entirely formed on the wall surface 21a, but may be partially formed. The throttle valve 30 may have a valve-side rough surface portion on the contact surface 31a of at least one of the plate surfaces 31. The valve-side rough surface portion 31a need not be entirely formed on the plate surface 31, but may be partially formed. At least one of the shaft-side rough surface portion 21a and the valve-side rough surface portion 31a may have a rough surface. The fastening member is not limited to the screw 40, but may be a bolt and nut, a set screw consisting of a male threaded member and a female threaded member with a threaded hole, or a rivet. The screw 40 is not limited to a cross-recessed countersunk head screw, but may be another type of screw member. [Explanation of symbols]

[0022] 10. Intake control valve 20 Throttle shaft 20b Outer surface 21 Slit hole 21a Wall surface (rough surface on shaft side) 30 Throttle valve 31 Board surface 31a Contact surface (rough surface on valve side) 31b Non-contact surface part 40 Screw (fastening member)

Claims

[Claim 1] a throttle shaft having a slit hole passing through it in the radial direction; a flat throttle valve inserted into the slit; a fastening member for fastening the throttle valve to the throttle shaft; An intake control valve comprising: when the throttle valve and the throttle valve are fastened together, the slit hole of the throttle shaft has two wall surfaces that come into surface contact with two plate surfaces of the throttle valve, and the two plate surfaces of the throttle valve have contact surface portions that come into surface contact with the two wall surfaces and non-contact surface portions that do not come into surface contact with the two wall surfaces, an intake control valve, wherein at least one of the two wall surfaces of the slit hole has a shaft-side rough surface portion having a surface roughness rougher than that of the outer peripheral surface of the throttle shaft, and / or the contact surface portion of at least one of the two plate surfaces of the throttle valve has a valve-side rough surface portion having a surface roughness rougher than that of the non-contact surface portion of the plate surface.

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