Intake control device

Abstract

This intake control device (1) achieves a reduction in size in a direction along a throttle shaft (6). The intake control device (1) comprises: the throttle shaft (6) that holds a throttle valve (5) for opening and closing an intake passage (2) in a throttle body (4), the throttle shaft (6) being supported by the throttle body (4); and an opening degree sensor (7) that detects the opening degree of the throttle valve (5). The opening degree sensor (7) comprises: a rotor (9) connected to the throttle shaft (6) via a protruding and recessed fitting part (8); and a Hall element (11) that outputs an electric signal corresponding to the rotational position of the rotor (9). The protruding and recessed fitting part (8) is located inside the throttle body (4).

Description

Intake control device

[0001] The present invention relates to an intake control device equipped with an opening sensor that detects the opening of a throttle valve.

[0002] BACKGROUND ART Conventionally, an intake control device is known that includes a throttle valve that opens and closes an intake passage of a throttle body and an opening sensor that detects the opening of the throttle valve, and controls the intake of air into an engine (see, for example, Patent Document 1).

[0003] In the intake control device described in Patent Document 1, a throttle valve is driven to open and close via a throttle drum fixed to one end of a throttle shaft. The opening sensor includes a rotor connected to the other end of the throttle shaft. This rotor rotates together with the throttle shaft, which rotates as the throttle valve is driven to open and close.

[0004] The sensor case of the throttle opening sensor is provided with a rotor support hole that rotatably supports a rotor that rotates together with the throttle shaft. The throttle shaft and the rotor are connected within the rotor support hole.

[0005] A stator is fixed to the sensor case and cooperates with the rotor to form an opening sensor, which outputs a signal from the stator that corresponds to the rotation angle of the rotor relative to the stator and indicates the opening of the throttle valve.

[0006] Japanese Patent Application Laid-Open No. 2007-127091

[0007] However, in recent years, there has been a growing demand for replacing intake control devices, such as those using conventional mechanical throttle bodies as disclosed in Patent Document 1, with small electronically controlled throttle bodies (ETBs) that can achieve more precise throttle valve opening control according to driving conditions, even in small motorcycles with small engine displacements.

[0008] To adequately meet this demand, the electronically controlled throttle body must be made as compact in size along the throttle shaft as a conventional mechanical throttle body, in order to satisfy customer requirements for ease of installation in vehicles.

[0009] SUMMARY OF THE INVENTION In view of the above problems of the prior art, an object of the present invention is to reduce the size of an intake control device in the direction along the throttle shaft.

[0010] The intake control device of the present invention comprises a throttle body having an intake passage wall that defines an intake passage, a throttle valve that opens and closes the intake passage, a throttle shaft that holds the throttle valve and is rotatably supported by the throttle body, and an opening sensor that detects the opening of the throttle valve.

[0011] The opening sensor comprises a rotor connected to one end of the throttle shaft via a concave-convex fitting and rotating together with the throttle shaft, a sensor case fixed to the rotor-side edge of the throttle body, and a detector provided within the sensor case that outputs an electrical signal corresponding to the rotational position of the rotor.

[0012] The concave-convex mating portion includes a recess provided on one of the throttle shaft or the rotor and recessed in the axial direction of the throttle shaft, and a protrusion provided on the other, protruding in the axial direction and mating with the recess. The cross-sectional shapes of the mating surfaces of the recess and the protrusion are non-circular, preventing relative rotation between the throttle shaft and the rotor. At least a portion of the concave-convex mating portion is located inside the throttle body.

[0013] According to the present invention, the intake control device can be made smaller in size in the direction along the throttle shaft.

[0014] 1 is a side view of an intake control device according to an embodiment of the present invention, and is a cross-sectional view taken along line II-II of FIG. 1. FIG.

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows an intake control device 1 according to an embodiment of the present invention as viewed from the opening sensor side. Fig. 2 shows a cross section taken along line II-II in Fig. 1. This intake control device 1 controls the amount of intake air supplied to a vehicle engine.

[0016] 1 and 2, the intake control device 1 includes a throttle body 4 having an intake passage wall 3 that defines an intake passage 2 therein, a throttle valve 5 that opens and closes the intake passage 2, a throttle shaft 6 that holds the throttle valve 5 and is rotatably supported by the throttle body 4, and an opening sensor 7 that detects the opening of the throttle valve 5. A butterfly valve is used as the throttle valve 5.

[0017] The opening sensor 7 is connected to one end of the throttle shaft 6 via a concave-convex fitting 8 and comprises a rotor 9 which rotates together with the throttle shaft 6, a sensor case 10 which is fixed to the edge of the throttle body 4 on the rotor 9 side, and a Hall element 11 which is provided within the sensor case 10 and serves as a detector which outputs a signal according to the rotational position of the rotor 9.

[0018] The concave-convex fitting portion 8 includes a recess 12 provided on one of the throttle shaft 6 or the rotor 9 and recessed in the axial direction A of the throttle shaft 6, and a protrusion 13 provided on the other and protruding in the axial direction A to fit into the recess 12. The cross-sectional shape of the fitting surfaces of the recess 12 and the protrusion 13 is non-circular, which prevents relative rotation between the throttle shaft 6 and the rotor 9. In this embodiment, the throttle shaft 6 is provided with the protrusion 13, and the rotor 9 is provided with the recess 12.

[0019] The protrusion 13 corresponds to, for example, a portion formed by flattening the end of the throttle shaft 6. Simply by fitting the protrusion 13 into the corresponding recess 12, the throttle shaft 6 and the rotor 9 are connected so that they cannot rotate relative to each other.

[0020] An accommodating recess 14 is provided on the edge of the throttle body 4 on the rotor 9 side, recessed along the axial direction A of the throttle shaft 6. The aforementioned concave-convex fitting portion 8 is disposed in this accommodating recess 14. The rotor 9, which rotates together with the throttle shaft 6, is provided with a magnet 15 facing a Hall element 11. The Hall element 11 detects the magnetic field emitted by the magnet 15 and outputs a signal corresponding to the rotational position of the rotor 9.

[0021] The throttle body 4 has a shaft insertion hole 16 into which the portion of the throttle shaft 6 supported by the throttle body 4 is inserted, the shaft insertion hole 16 communicating with the bottom of the accommodation recess 14. The inner diameter of the accommodation recess 14 is larger than the inner diameter of the shaft insertion hole 16.

[0022] Figure 3 shows a cross section taken along line III-III in Figure 1, viewed in a direction along the intake passage 2. As shown in Figure 3, the throttle body 4 has a mounting surface 17 for attaching the sensor case 10 to the throttle body 4. The mounting surface 17 is provided with bolt holes 19 for fixing the sensor case 10 to the mounting surface 17 with bolts 18. The corresponding surfaces of the sensor case 10 are pressed against the mounting surface 17 by the bolts 18 to fix them.

[0023] In this embodiment, the mounting surface 17 is configured as a plane perpendicular to the axial direction A of the throttle shaft 6. The intake passage 2 side of the plane P including the mounting surface 17 in the throttle body 4 is defined as the interior of the throttle body 4. More generally, even if there is a portion of the throttle body 4 that is recessed from the mounting surface 17, the portion that is located closer to the intake passage 2 than the surrounding mounting surface 17 portion is considered to be the interior of the throttle body 4.

[0024] Considering this point, the accommodation recess 14 that accommodates the concave-convex fitting portion 8 is formed as a portion of the mounting surface 17 that is recessed toward the intake passage 2, and therefore corresponds to the interior of the throttle body 4. Therefore, all or part of the concave-convex fitting portion 8 arranged in the accommodation recess 14 is located inside the throttle body 4.

[0025] The throttle body 4 also includes a mounting flange 20 for mounting an intake pipe (not shown) to the throttle body 4. The mounting flange 20 opens to a seating surface of the mounting flange 20 that is perpendicular to the passage direction of the intake passage 2, and has bolt holes 21 for fixing the intake pipe to the seating surface.

[0026] The edge of the mounting flange 20 on the sensor case 10 side constitutes part of the mounting surface 17 to which the sensor case 10 is fixed. Bolt holes 19 are provided in part of this mounting surface 17 for fixing the sensor case 10 with the above-mentioned bolts 18. Note that the sensor case 10 is also fixed to other parts of the mounting surface 17 with other bolts 18 (see FIG. 1).

[0027] In the axial direction A, the position P1 of the tip of the bolt 18 for mounting the sensor case 10, which is screwed into the bolt hole 19 of the mounting flange 20, is located closer to the sensor case 10 than the position P2 of the edge of the bolt hole 21 for mounting the intake pipe on the sensor case 10 side.

[0028] The throttle body 4 is also provided with a motor housing 22 that houses a motor for driving the opening and closing of the throttle valve 5. A valve gear 23 for rotating the throttle shaft 6 is fixed to the end of the throttle shaft 6 opposite the rotor 9.

[0029] A reducer is provided between the valve gear 23 and a pinion gear 24 fixed to the output shaft of the motor, which reduces the rotation of the pinion gear 24 and transmits it to the valve gear 23. This reducer is composed of, for example, a large-diameter gear 25 that meshes with the pinion gear 24, and a small-diameter gear (not shown) that is fixed coaxially with the large-diameter gear 25 and meshes with the valve gear 23.

[0030] In an intake control device 1 having such a configuration, if the distance D between the mounting surface 17 of the opening sensor 7 on the throttle body 4 and the intake passage 2 (distance between the mounting surface and the intake passage) can be reduced, it is possible to make the intake control device 1 smaller in the axial direction A of the throttle shaft 6.

[0031] However, if the distance D between the mounting surface and the intake passage is reduced, the bolt holes 19 for mounting the sensor case 10 and the bolt holes 21 for mounting the intake pipe will be closer to each other, reducing the rigidity of the mounting flange 20. For this reason, it is necessary to ensure a certain degree of distance D between the mounting surface and the intake passage.

[0032] Therefore, in this embodiment, the distance D between the mounting surface and the intake passage is such that, in the axial direction A of the throttle shaft 6, the position P1 of the tip of the bolt 18 for mounting the sensor case 10 is located closer to the sensor case 10 than the position P2 of the edge of the bolt hole 21 for mounting the intake pipe on the sensor case 10 side. This prevents the mounting flange 20 from becoming weaker due to the above-mentioned reason.

[0033] After ensuring that the distance D between the mounting surface and the intake passage is a certain size as described above, the concave-convex fitting portion 8 is disposed in the accommodation recess 14 recessed from the mounting surface 17 into the interior of the throttle body 4. In other words, the concave-convex fitting portion 8, which has a certain length in the axial direction A, is disposed inside the throttle body 4, not inside the sensor case 10.

[0034] Therefore, compared to the conventional intake control device (see Patent Document 1) in which the concave-convex fitting portion 8 is arranged inside the sensor case 10, the dimension of the sensor case 10 in the axial direction A is reduced by the amount of the concave-convex fitting portion 8 arranged inside the throttle body 4. This reduces the dimension of the intake control device 1 in the axial direction A.

[0035] When the intake control device 1 operates, the motor in the motor housing portion 22 is driven based on the throttle operation of the vehicle in which the intake control device 1 is installed, an opening signal indicating the opening of the throttle valve 5 from the opening sensor 7, etc. The rotation of the motor is transmitted to the throttle shaft 6 via a reducer and is used to open and close the throttle valve 5. This allows the opening of the throttle valve 5 to be appropriately controlled, and an appropriate amount of intake air is supplied to the vehicle engine.

[0036] As described above, according to this embodiment, the concave-convex fitting portion 8 that connects the rotor 9 to the throttle shaft 6 is located inside the throttle body 4, so the dimensions of the intake control device 1 along the axial direction A of the throttle shaft 6 can be reduced.

[0037] Even in this case, the distance D between the mounting surface and the intake passage is set so that the position P1 of the tip of the bolt 18 for mounting the sensor case 10 is located closer to the sensor case 10 than the position P2 of the edge of the bolt hole 21 for mounting the intake pipe on the sensor case 10 side, thereby ensuring the necessary rigidity of the mounting flange 20.

[0038] Furthermore, the interior of the throttle body 4 where the concave-convex fitting portion 8 is located is the interior of the accommodating recess 14 which is recessed along the throttle shaft 6 at the end edge on the rotor 9 side of the throttle body 4, so the concave-convex fitting portion 8 can be easily positioned inside the throttle body 4.

[0039] Furthermore, the inner diameter of the accommodation recess 14 that accommodates the concave-convex fitting portion 8 is larger than the inner diameter of the shaft insertion hole 16 into which the portion of the throttle shaft 6 supported by the throttle body 4 is inserted. As a result, even if the outer diameter of the portion of the rotor 9 that constitutes the concave-convex fitting portion 8 is larger than the outer diameter of that portion of the throttle shaft 6, by appropriately setting the inner diameter of the accommodation recess 14 in accordance with that outer diameter of the rotor 9, the portion of the rotor 9 that constitutes the concave-convex fitting portion 8 can be accommodated within the accommodation recess 14 of the throttle body 4.

[0040] In addition, the rotor 9 that rotates together with the throttle shaft 6 is equipped with a magnet 15, and the detector that outputs an electrical signal corresponding to the rotational position of the rotor 9 is a Hall element 11 that detects the magnetic field emitted by the magnet 15, so the rotational position of the rotor 9 can be detected with high accuracy.

[0041] Furthermore, an electric intake control device such as this embodiment, which is equipped with a reducer that transmits the rotation of the motor's pinion gear 24 to the valve gear 23 fixed to the end of the throttle shaft 6 opposite the rotor 9, generally increases in size in the axial direction A of the throttle shaft 6. Therefore, by adopting the configuration of this embodiment, which has the effect of reducing the size of such an electric intake control device in the axial direction A, it is possible to enjoy this effect with particularly high value.

[0042] Although the embodiment of the present invention has been described above, the present invention is not limited to this. For example, the opening sensor 7 may be a potentiometer whose resistance value changes depending on the position of the throttle valve 5.

[0043] 1...intake control device, 2...intake passage, 3...intake passage wall, 4...throttle body, 5...throttle valve, 6...throttle shaft, 7...opening sensor, 8...concave-convex fitting portion, 9...rotor, 10...sensor case, 11...hall element, 12...recess, 13...protrusion, 14...accommodating recess, 15...magnet, 16...shaft insertion hole, 17...mounting surface, 18...bolt, 19...bolt hole, 20...mounting flange, 21...bolt hole, 22...motor accommodating portion, 23...valve gear, 24...pinion gear, 25...large diameter gear

Claims

1. An intake control device comprising: a throttle body having an intake passage wall that defines the intake passage; a throttle valve that opens and closes the intake passage; a throttle shaft that holds the throttle valve and is rotatably supported by the throttle body; and an opening sensor that detects the opening of the throttle valve, wherein the opening sensor comprises: a rotor that is connected to one end of the throttle shaft via a concave-convex fitting and rotates together with the throttle shaft; a sensor case that is fixed to the edge of the throttle body on the rotor side; and a detector that is provided within the sensor case and outputs an electrical signal according to the rotational position of the rotor, wherein the concave-convex fitting comprises a recess that is provided on either the throttle shaft or the rotor and is recessed in the axial direction of the throttle shaft, and a protrusion that is provided on the other and protrudes in the axial direction and fits into the recess, and wherein the cross-sectional shapes of the fitting surfaces of the recess and the protrusion are non-circular to prevent relative rotation between the throttle shaft and the rotor, An intake control device, wherein at least a portion of the concave-convex fitting portion is located inside the throttle body.

2. The intake control device described in claim 1, characterized in that the interior of the throttle body where the concave-convex fitting portion is located is the interior of a accommodating recess that is recessed along the throttle shaft at the rotor-side edge of the throttle body, the throttle body has a shaft insertion hole into which the throttle shaft is inserted and which leads to the accommodating recess, and the inner diameter of the accommodating recess is larger than the inner diameter of the shaft insertion hole.

3. The intake control device according to claim 1, wherein the rotor is provided with a magnet, and the detection body is a Hall element that detects the magnetic field generated by the magnet.

4. An intake control device as described in claim 1, characterized in that it comprises a valve gear fixed to the end of the throttle shaft opposite the rotor, and a reducer that reduces the rotation of a pinion gear fixed to the output shaft of a motor and transmits it to the valve gear.

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