Intake valve device

Abstract

To provide an intake valve device for stabilizing the function of preventing positional deviation of a throttle valve when fixing the throttle valve to a throttle shaft.SOLUTION: The intake valve device has a throttle valve 40 fixed to a throttle shaft 30. In the throttle shaft 30, a valve insertion slit 33 into which the throttle valve 40 is inserted is formed in a state of penetrating therethrough in the radial direction. The throttle valve 40 inserted into the valve insertion slit 33 is fixed to the throttle shaft 30 with a fastening mechanism. The valve insertion slit 33 has a slit central part 33c and a pair of tapered parts 33f, 33r that expand as separating from one axial end side and the other end side of the slit central part 33c in the axial direction. The throttle valve 40 is fixed to the throttle shaft 30 at the positions of the tapered parts 33f, 33r of the valve insertion slit 33 with the fastening mechanism.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present technology relates to an intake valve device that includes a throttle body having an intake passage, a throttle shaft that crosses the intake passage and is supported by a bearing of the throttle body, and a disc-shaped throttle valve that is fixed to the throttle shaft and can adjust the opening of the intake passage. [Background technology]

[0002] A technique related to the above-mentioned intake valve device is described in Patent Document 1. As shown in Fig. 6, the intake valve device 100 described in Patent Document 1 includes a throttle body 103 having an intake passage 102 formed therein. The intake valve device 100 also includes a throttle shaft 104 that crosses the intake passage 102 and is supported by a bearing 103j of the throttle body 103, and a disc-shaped throttle valve 106 that is fixed to the throttle shaft 104 and can adjust the opening of the intake passage 102.

[0003] As shown in Figures 6 and 7, the throttle shaft 104 is formed with a valve insertion slit 104s, into which a throttle valve 106 is inserted, extending radially therethrough. Furthermore, as shown in Figure 7, sharp, thorn-like protrusions 104t are formed at the positions of both openings of the valve insertion slit 104s. The throttle valve 106 inserted into the valve insertion slit 104s is fixed to the throttle shaft 104 with screws 107. At this time, the protrusions 104t at both openings of the valve insertion slit 104s bite into the front and back surfaces of the throttle valve 106, preventing the throttle valve 106 from shifting position relative to the throttle shaft 104. Here, burrs or the like left over from cutting are suitably used to form the thorn-like protrusions 104t. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2012-172544 Summary of the Invention [Problem to be solved by the invention]

[0005] In the intake valve device 100, thorn-like protrusions 104t are formed in the valve insertion slit 104s of the throttle shaft 104, and these thorn-like protrusions 104t are caused to bite into the front and back surfaces of the throttle valve 106, thereby preventing misalignment of the throttle valve 106. However, with a configuration in which the thorn-like protrusions 104t are formed by burrs or the like, there is a large variation in the misalignment prevention function, and the effect is not stable.

[0006] This technology has been made to solve the above-mentioned problems, and the problem that the present invention aims to solve is to stabilize the function of preventing the throttle valve from shifting position when fixing the throttle valve to the throttle shaft. [Means for solving the problem]

[0007] The above-mentioned problems can be solved by various technologies. A first technology is an intake valve device having a throttle body with an intake passage, a throttle shaft that crosses the intake passage and is supported by a bearing of the throttle body, and a disc-shaped throttle valve that is fixed to the throttle shaft and can adjust the opening of the intake passage, wherein a valve insertion slit into which the throttle valve is inserted is formed radially penetrating the throttle shaft, the throttle valve inserted into the valve insertion slit is fixed to the throttle shaft by a fastening mechanism, the valve insertion slit of the throttle shaft has a slit center portion and a pair of tapered portions that widen as they move away from one axial end side and the other axial end side of the slit center portion, and the throttle valve is fixed to the throttle shaft by the fastening mechanism at the position of the tapered portion of the valve insertion slit.

[0008] According to the first technology, the valve insertion slit of the throttle shaft has a slit center and a pair of tapered portions that widen as they move away from one axial end and the other axial end of the slit center. Therefore, when a throttle valve is inserted into the valve insertion slit of the throttle shaft, a gap is formed between the throttle valve and the tapered portion of the valve insertion slit. The throttle valve is then fixed to the throttle shaft by a fastening mechanism at the position of the tapered portion of the valve insertion slit. As a result, the throttle valve is pressed from both the front and back sides at the slit center of the valve insertion slit by fastening the fastening mechanism. That is, with the throttle valve fixed to the throttle shaft by the fastening mechanism, contact pressure increases at the slit center of the valve insertion slit, particularly at the boundary between the slit center and the tapered portion. This prevents the throttle valve from shifting relative to the throttle shaft. Furthermore, because the valve insertion slit of the throttle shaft can be accurately formed from the slit center and the tapered portion, the function of preventing the throttle valve from shifting is stabilized. [Effects of the Invention]

[0009] According to the technology of the present application, when the throttle valve is fixed to the throttle shaft, the function of preventing the throttle valve from shifting position can be stabilized. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a plan view illustrating an intake valve device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along the line II-II in FIG. [Figure 3] 3 is a side view (enlarged view taken along arrow III in FIG. 2) showing a valve insertion slit of the throttle shaft. FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3. [Figure 5] FIG. 4 is a vertical cross-sectional view showing a structure for fixing a throttle valve to a throttle shaft by a screw. [Figure 6]FIG. 1 is a vertical cross-sectional view showing a conventional intake valve device. [Figure 7] FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Embodiment 1] An intake valve device 10 according to a first embodiment of the present invention will be described below with reference to Figures 1 to 5. The intake valve device 10 according to this embodiment is a device that adjusts the flow rate of combustion air supplied to a vehicle engine. Here, front, rear, left, right, and up and down shown in the figures correspond to front, rear, left, right, and up and down of the intake valve device 10.

[0012] <Overview of the intake valve device 10> As shown in FIGS. 1 and 2, the intake valve device 10 has a throttle body 20 with an intake passage 22 through which combustion air flows. The throttle body 20 is made of resin or metal and has a hollow, cylindrical intake passage 22 extending vertically in its center. As shown in FIG. 1, a disc-shaped throttle valve 40 that can adjust the opening of the intake passage 22 is housed in the intake passage 22. The throttle valve 40 is attached with a screw 50 to a metal throttle shaft 30 that crosses the intake passage 22. As shown in FIG. 2, the throttle shaft 30 is supported by bearings 23 provided on the left and right side walls of the throttle body 20 so that it can rotate about its axis. This allows the throttle valve 40 to rotate integrally with the throttle shaft 30. Rotation of the throttle valve 40 adjusts the opening of the intake passage 22, thereby regulating the flow rate of combustion air.

[0013] <Assembly structure of throttle valve 40 to throttle shaft 30> As shown in Fig. 2, a valve insertion slit 33, into which the throttle valve 40 is inserted, is formed so as to penetrate radially through the throttle shaft 30. As shown in Fig. 3, the valve insertion slit 33 of the throttle shaft 30 is made up of a slit central portion 33c located in the axial center of the throttle shaft 30, a left tapered portion 33f formed on the left side of the slit central portion 33c, and a right tapered portion 33r formed on the right side of the slit central portion 33c.

[0014] As shown in Fig. 4, the slit width dimension of the slit center portion 33c of the valve insertion slit 33 from the left end C1 to the right end C2 is set to a value larger than the thickness dimension of the throttle valve 40 by an amount corresponding to a clearance. Also, as shown in Fig. 3, the left tapered portion 33f is formed so as to gradually widen as it moves away from the left end C1 of the slit center portion 33c to the left in the axial direction. The right tapered portion 33r is formed so as to gradually widen as it moves away from the right end C2 of the slit center portion 33c to the right in the axial direction.

[0015] That is, the left and right tapered portions 33f, 33r of the valve insertion slit 33 are formed symmetrically. At the positions of the left and right tapered portions 33f, 33r, as shown in Fig. 3, gaps are formed between the wall surfaces of these tapered portions 33f, 33r and the front and back surfaces of the throttle valve 40. Furthermore, the throttle shaft 30 is formed with female threaded holes 35, into which screws 50 are fastened, near the axially outer sides of the left end C1 and right end C2 of the slit center portion 33c, at the positions of the left and right tapered portions 33f, 33r.

[0016] 1, 2, etc., the throttle valve 40 is made by processing a metal plate material into a perfect circular shape and is set to a substantially constant wall thickness. Screw insertion holes 43, through which screws 50 are inserted, are formed on the diameter line of the throttle valve 40 at positions corresponding to the left and right female threaded holes 35 of the throttle shaft 30, as shown in Fig. 3. The screw insertion holes 43 are formed with a larger diameter than the female threaded holes 35.

[0017] <Assembling procedure of the throttle valve 40 to the throttle shaft 30> When assembling the throttle valve 40 to the throttle shaft 30, the throttle valve 40 is radially inserted into the valve insertion slit 33 of the throttle shaft 30. Here, the slit width of the slit center portion 33c, where the slit width dimension is smallest, is set to be larger than the thickness dimension of the throttle valve 40 by an amount corresponding to clearance. This allows the throttle valve 40 to be smoothly inserted into the valve insertion slit 33 of the throttle shaft 30. Next, the left and right screw insertion holes 43 of the throttle valve 40 are aligned with the left and right female threaded holes 35 of the throttle shaft 30, and screws 50 are fastened to the left and right female threaded holes 35 of the throttle shaft 30, as shown in FIG. 5 etc. This fixes the throttle valve 40 to the throttle shaft 30.

[0018] As shown in FIG. 5, at the position of the tapered portion 33f of the valve insertion slit 33, gaps are formed between the wall surfaces of the tapered portion 33f and the front and back surfaces of the throttle valve 40. Therefore, when the screw 50 is fastened to the female threaded hole 35, the fastening force displaces the wall surfaces of the tapered portion 33f of the throttle shaft 30 so as to sandwich the throttle valve 40 from above and below (see white arrows). As a result, the slit center portion 33c, which is already in contact with the front and back surfaces of the throttle valve 40, presses against the front and back surfaces of the throttle valve 40 (see arrows). In particular, the pressing force at the left end C1 (boundary portion) of the slit center portion 33c becomes large. This increases the contact pressure between the slit center portion 33c of the valve insertion slit 33 and the front and back surfaces of the throttle valve 40. As a result, displacement of the throttle valve 40 relative to the throttle shaft 30 is prevented. Furthermore, since the valve insertion slit 33 of the throttle shaft 30 can be formed with high precision from the slit central portion 33c and the tapered portions 33f, 33r, the function of preventing the throttle valve 40 from shifting position can be stabilized.

[0019] <Regarding the correspondence between the terms used in this embodiment and the terms used in the present invention> In this embodiment, the screw 50, the screw insertion hole 43 of the throttle valve 40, and the female threaded hole 35 of the throttle shaft 30 correspond to the fastening mechanism of the present invention.

[0020] <Advantages of the intake valve device 10 according to this embodiment> In the intake valve device 10 according to this embodiment, the throttle valve 40 is fixed to the throttle shaft 30 by a screw 50 (fastening mechanism) at the tapered portions 33f, 33r of the valve insertion slit 33. As a result, the slit center portion 33c of the valve insertion slit 33 of the throttle shaft 30 is subjected to the fastening force of the screw 50 and is pressed against the front and back surfaces of the throttle valve 40. The pressing force is particularly strong at the boundary portions C1, C2 between the slit center portion 33c and the tapered portion 33f. That is, with the throttle valve 40 fixed to the throttle shaft 30 by the screw 50, the contact pressure of the slit center portion 33c of the valve insertion slit 33 increases. As a result, misalignment of the throttle valve 40 with respect to the throttle shaft 30 is prevented. Furthermore, because the valve insertion slit 33 of the throttle shaft 30 can be accurately formed by the slit center portion 33c and the tapered portions 33f, 33r, the function of preventing misalignment of the throttle valve 40 can be stabilized.

[0021] The present invention is not limited to the above-described embodiment, and modifications are possible within the scope of the present invention. For example, in this embodiment, the wall surface of the slit center portion 33c of the valve insertion slit 33 is formed flat in the radial direction of the throttle shaft 30, as shown in FIG. 4. However, a configuration in which a protrusion extending in the axial direction of the throttle shaft 30 is formed on the wall surface of the slit center portion 33c is also possible. This further increases the contact pressure between the slit center portion 33c of the valve insertion slit 33 and the front and back surfaces of the throttle valve 40. [Explanation of symbols]

[0022] 20 Throttle body 22... Intake passage 23 Bearing 30 Throttle shaft 33 Valve insertion slit 33c Center of the slit 33f...Left tapered section 33r Right tapered section 35... Female thread hole (fastening mechanism) 40 Throttle valve 43 Screw insertion hole (fastening mechanism) 50····Screw (fastening mechanism) C1...Left end C2...Right end

Claims

[Claim 1] An intake valve device comprising: a throttle body having an intake passage; a throttle shaft that crosses the intake passage and is supported by a bearing of the throttle body; and a disc-shaped throttle valve that is fixed to the throttle shaft and is capable of adjusting an opening degree of the intake passage, a valve insertion slit into which the throttle valve is inserted is formed in a radially penetrating state in the throttle shaft, The throttle valve inserted into the valve insertion slit is fixed to the throttle shaft by a fastening mechanism, the valve insertion slit of the throttle shaft has a slit center portion and a pair of tapered portions that widen as they move away from one axial end side and the other axial end side of the slit center portion in the axial direction, The throttle valve is fixed to the throttle shaft by the fastening mechanism at the position of the tapered portion of the valve insertion slit.

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