Throttle device

Abstract

A throttle device, comprising: a throttle valve (13) disposed in a plurality of intake passages (12) of a throttle body (11); a throttle shaft (14) supporting the throttle valve (13); a motor (15) for driving the throttle valve (13) to open and close through the throttle shaft (14); a rotation transmission mechanism (20) interposed between the motor (15) and the throttle shaft (14); and a position sensor to detect a displacement in the rotation transmission mechanism (20). The rotation transmission mechanism (20) includes a pinion (21) driven by the motor (15) and a control gear (23) interlocked with the pinion (21) and integrally connected to the throttle shaft (14). The position sensor (30) to detect an angular displacement of the control gear (23) and the rotation transmission mechanism (20) are disposed between the plurality of intake passages 12.

Claims

1. A throttle device mounted on an engine having a plurality of intake ports, the throttle device comprising: a first throttle body having a first intake passage and a second throttle body having a second intake passage; a first throttle valve provided in the first intake passage and a second throttle valve provided in the second intake passage; a throttle shaft supporting the first throttle valve and the second throttle valve; an actuator that drives the first throttle valve and the second throttle valve to open and close through the throttle shaft; a rotation transmission mechanism interposed between the actuator and the throttle shaft; and a position sensor that detects a displacement in the rotation transmission mechanism, wherein the rotation transmission mechanism includes a first transmission member driven by the actuator and a second transmission member capable of interlocking with the first transmission member and is-the second transmission member is integrally connected to the throttle shaft in a rotation direction, the position sensor, that detects the displacement of the second transmission member, and the rotation transmission mechanism are disposed between the first throttle body and the second throttle body, the position sensor includes a movable side detection element supported by the second transmission member and a fixed side detection element arranged on an accommodation cover in which the rotation transmission mechanism is accommodated, and the fixed side detection element is configured to detect an angle displacement of the movable side detection element, the movable side detection element is disposed on a surface of the second transmission member, the surface extending in a radial direction of the throttle shaft and opposed to an accommodation cover covering the rotation transmission mechanism on one side, the second throttle body having an accommodation portion for accommodating the actuator, the first throttle body and the second throttle body integrally fastened in a direction in which the first throttle body and the second throttle body are adjacent to each other, the first throttle body, constituted by integrally connecting the accommodation cover covering the rotation transmission mechanism on one side with one of the throttle bodies, and the second throttle body, constituted by integrating the accommodation portion with the other one of the throttle bodies, and the throttle device has the position sensor between the first intake passage and the second intake passage.

2. The throttle device according to claim 1, further comprising a torsion coil spring interposed between one of the throttle bodies and the throttle shaft and biasing a throttle valve of the plurality of throttle valves to a predetermined opening degree position, wherein the position sensor is disposed radially outwardly of an arrangement region of the torsion coil spring.

3. The throttle device according to claim 1, wherein the movable side detection element of the position sensor is constituted by a magnet or a brush disposed on a side surface on one end side in a tooth width direction of the second transmission member, and the fixed side detection element of the position sensor is constituted by a Hall element or a resistance coating film.

4. The throttle device according to claim 1, wherein the movable side detection element and the fixed side detection element are opposed to each other in a radial direction of the second transmission member, and the movable side detection element is opposed to a meshing teeth portion of the second transmission member in a radial direction of the second transmission member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic configuration diagram of a main part of a throttle device according to an embodiment of the present invention.

(2) FIG. 2 is a schematic configuration diagram of a throttle device in its entirety in the case where the throttle device according to one embodiment of the present invention is mounted on a four-cylinder engine.

(3) FIG. 3 is a front view of a throttle device in the case where the throttle device according to one embodiment of the present invention is mounted on a four-cylinder engine.

(4) FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3.

(5) FIGS. 5A and 5B show front views of two examples where two of the throttle devices mounted on the four-cylinder engine are conventionally configured.

(6) FIG. 6 is a schematic configuration diagram of a throttle device in its entirety in the case where the throttle device according to one embodiment of the present invention is mounted on a three-cylinder engine.

DETAILED DESCRIPTION OF THE INVENTION

(7) Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

One Embodiment

(8) FIGS. 1-4 show a configuration of a throttle device according to an embodiment of the present invention.

(9) First, the configuration will be described.

(10) As shown in FIG. 1 and FIG. 2, the throttle device 10 of the present embodiment is a multiple type throttle device adapted to a multi-cylinder internal combustion engine, for example, a four-cylinder engine 1 for a two-wheeled vehicle. Although not described in detail here about the engine 1, a plurality of cylinders 1c are adjacent to each other in the left-right direction (vehicle width direction) with respect to the body frame extending in the front-rear direction of the two-wheeled vehicle (the direction perpendicular to the paper surface of FIG. 2). This means that the crankshaft is mounted in a horizontally placed state extending in the vehicle width direction. As shown in FIG. 3, a pair of throttle devices 10 (10A, 10B in FIG. 3) are arranged in parallel to the engine 1 so as to be adjacent to each other on the left and right sides.

(11) As shown in FIG. 1, the throttle device 10 includes a throttle body portion 11a (a first throttle body) having an intake passage 12a (a first intake passage), a throttle body portion 11b (a second throttle body) having an intake passage 12b (a second intake passage), a common (same) throttle shaft 14 rotatably supported with respect to the throttle body portions 11a and 11b, a motor 15 capable of opening and closing the plurality of the throttle valves 13a and 13b through the throttle shaft 14 and a rotation transmission mechanism 20.

(12) Further, the rotation transmission mechanism 20 is disposed between the throttle body portions 11a and 11b, so as to be connected to the throttle shaft 14 at a position between the adjacent throttle valves 13a and 13b, thereby making it possible to transmit power to the substantially central position of the throttle shaft 14.

(13) The throttle body portions 11a, 11b respectively have an inner circumferential wall surface of a circular cross section and are arranged to be parallel to each other, and form a plurality of intake passages 12a, 12b (a plurality of branch passages in the case of a manifold) communicating with the plurality of intake ports 1a. Further, a plurality of throttle valves 13a, 13b are provided in the respective intake passages 12a, 12b, so that the opening degree of throttle valves 13a, 13b can be controlled. In FIG. 1, the shape of the body portion (unit body 11 to be described later) except for the plurality of throttle body portions 11a and 11b and a periphery of a rotational transmission path between the throttle body portions 11a and 11b are schematically shown with a quadrangle. In addition, the plurality of throttle valves 13a and 13b are respectively of a type in which they are rotated in the valve opening and closing directions, for example a butterfly type, but may be of other types.

(14) The throttle shaft 14 functions as a rotation center axis for rotatably supporting the plurality of throttle valves 13a, 13b in a fixed length region on both end sides thereof, and rotates in accordance with the rotational (angle) operation amount from the motor 15 through the rotation transmission mechanism 20 at a shaft center portion of the throttle shaft 14, thereby making it possible to control an opening degree of the throttle valves 13a and 13b.

(15) The motor 15 is an actuator, which is for example a pulse motor such as a step motor or the like, and is adapted to control the rotational angle position of the throttle shaft 14 corresponding to the opening position (throttle position) required for the throttle valves 13a, 13b, based on the acceleration request input according to the accelerator operation of the two-wheeled vehicle.

(16) The rotation transmission mechanism 20 includes a pinion 21 integrally mounted on the rotation output shaft of the motor 15, an idler gear 22 supported on the unit body 11 so as to be rotatable around the axis while being engaged with the pinion 21, and a control gear 23 integrally connected to the throttle shaft 14 while being engaged with the idler gear 22.

(17) This means that the rotation transmission mechanism 20 is provided, between a pair of intake passages 12a, 12b adjacent to each other in the left-right direction of the vehicle, with a pinion 21, which is a gear constituting a first transmission member driven by the motor 15, and a control gear 23 which is a gear interlocked with the pinion gear and constituting a second transmission member integrally connected to the throttle shaft 14 in the rotation direction, and further is further provided with an idler gear 22 interposed between the two gears.

(18) In the rotation transmission mechanism 20, the pitch circle radius increases in the order of the pinion 21, the idler gear 22, and the control gear 23, which are interposed between the motor 15 and the throttle shaft 14, thereby making it possible to fulfill the deceleration function and the high precision positioning function.

(19) The throttle device 10 further includes a movable side detection element 31 supported by the control gear 23 and a fixed side detection element 32 capable of detecting the angular displacement (displacement) of the movable side detection element 31. The movable side detection element 31 and the fixed side detection element 32 constitute a position sensor 30 (throttle position sensor) adapted to detect the angular displacement of the throttle shaft 14 and the control gear 23, which is the displacement of the specific portion in the rotation transmission mechanism 20 corresponding to the opening degree of the throttle valves 13a, 13b, and to output a position signal Pth.

(20) The movable side detection element 31 of the position sensor 30 is constituted by a magnet (which may be a magnetic pattern in which magnetic poles of N/S are alternately arranged) or a brush disposed on a side surface on one end side in the tooth width direction of the control gear 23, while the fixed side detection element 32 of the position sensor 30 is constituted by a Hall element or a resistance coating film.

(21) In FIG. 2, the throttle device 10 is exemplified in a layout adapted to the four-cylinder engine 1. In the figure, two throttle devices 10, each covering a plurality of intake ports 1a aligned in the cylinder arrangement direction of the engine 1 for each two cylinders, each having a full width W1, respectively have a unit body 11 constituted by integrating the throttle body portions 11a, 11b. In each unit body 11, the throttle body portions 11a, 11b are provided adjacently so that intake passages 12a, 12b communicating with the plurality of intake ports 1a are arranged in parallel, while in the intake passages 12a, 12b, a plurality of throttle valves 13a and 13b are provided so as to control the opening degree.

(22) FIGS. 3 and 4 show an embodiment in which the throttle device 10 is applied to a four-cylinder engine 1 for a two-wheeled vehicle. The unit body 11 is provided with a plurality of fuel injection valves 41 capable of injecting fuel into the plurality of intake passages 12a and 12b and a fuel pipe 42 for distributing and supplying fuel to the plurality of fuel injection valves 41. Further, the unit body 11 is constituted by a first segment body 11f (first throttle body) and a second segment body 11s (second throttle body) integrally fastened in a direction in which the throttle body portions 11a, 11b are adjacent to each other (left and right direction in FIG. 3), the first throttle body (first throttle body) constituted by integrally connecting a gear cover portion 11c covering the rotation transmission mechanism 20 on one side with one of the throttle body portions 11a or 11b, and a second segment body 11s (second throttle body) constituted by integrating a motor cover portion 11d (accommodating portion) for accommodating the motor 15 with one of the other throttle body portions 11b or 11a are disposed adjacent to the throttle body portions 11a and 11b. Further, the fuel injection valve 41 is provided in each of the first segment body 11f and the second segment body 11s, and the fuel pipe 42 is so provided to connect the first segment body 11f and the second segment body 11s.

(23) As shown in FIGS. 1, 3 and 4, the movable side detection element 31 is disposed on an opposing surface 23a (one side surface, the surface in a radial direction of the shaft) of the control gear 23 opposed to the gear cover portion 11c. The fixed side detection element 32 is mounted on the gear cover portion 11c. By his configuration, there is no need to provide a separate case for the position sensor. When an urging unit such as a torsion coil spring 16 for biasing the control gear 23 to a predetermined rotational angle position or a bearing and the like is provided, it is preferable to dispose the movable side detection element 31 and the fixed side detection element 32 in a radially outward side of a region where the torsion coil spring 16 or the like is provided. The urging unit such as the torsion coil spring 16 mentioned here is interposed between, for example, the unit body 11 and the throttle shaft 14 or the control gear 23, so as to urge the throttle valves 13a, 13b at a predetermined opening position (typically a valve close position) around the throttle shaft 14, wherein the radially outward side refers to a position at an arbitrary radial position outside the radial region necessary for installing the urging unit such as the torsion coil spring 16.

(24) Next, the operation will be described.

(25) In the throttle device 10 of the present embodiment, when the pinion 21 is driven by the motor 15 in response to the acceleration request input according to the accelerator operation of the two-wheeled vehicle, the throttle shaft 14 rotates integrally with the control gear 23 that is engaged therewith, so that the degree of opening of the throttle valves 13a and 13b changes. This means that the control of the rotational angle position of the throttle shaft 14 corresponding to the opening degree position required for the throttle valves 13a, 13b is executed.

(26) During the control of the rotational angular position, the angular displacement of the movable side detection element 31 supported on the opposing surface 23a (side surface) of the control gear 23 is detected by the fixed side detection element 32 disposed on the side of the gear cover 11c, as the rotational angular position of the control gear 23 directly connected to the throttle shaft 14, so that the opening degree of the throttle valve 13a, 13b is detected.

(27) In the present embodiment, it is not necessary to provide a separate rotation transmission element such as a sensor shaft (a functional portion around the intake passage) in order to transmit the angular displacement of the throttle shaft 14 to the position sensor 30. Accordingly, interval d1 (See FIG. 2) between the two intake passages 12a, 12b which are disposed adjacent to each other in a cylinder arrangement direction of the engine 1 sandwiching the rotation transmission mechanism 20 and a width dimension of a thick portion (a portion surrounding the rotation transmission mechanism 20) of the unit body 11 corresponding to the d1 can be kept small.

(28) Further, in the present embodiment, two unit bodies 11 are combined to adapt to the four-cylinder engine 1, so that an interval d2 between the two central throttle body portions 11a, 11b can be narrowed. Furthermore, by combining the two unit bodies 11 to the four-cylinder engine 1, the degree of freedom of installation also increases.

(29) Further, the movable side detection element 31 of the position sensor 30 is disposed on the opposing surface 23a of the control gear 23 opposed to the gear cover portion 11c of the unit body 11, and a fixed position of the fixed side detection element 32 to detect the rotation of the movable side detection element 31 is in the vicinity of a facing surface of the gear cover portion 11c of the first segment body 11f (throttle body) in the rotational radius region of the opposing surface 23a of the control gear 23. Therefore, the implementation form of the position sensor 30 in the throttle device 10 is extremely compact and the implementation work is easy. Thus, the arrangement of the position sensor can be easy, and the space for the arrangement can be reduced, and the interval d1 between the intake passages 12a, 12b can be narrowed.

(30) Furthermore, in the present embodiment, since the movable side detection element 31 and the fixed side detection element 32 of the position sensor 30 are respectively disposed at predetermined rotational radial positions of the control gear 23, even though other member, for example the torsion coil spring 16 that urges the control gear 23 to a predetermined angular position or the like, is disposed inside the radical is disposed, the position sensor can be disposed outside the radial direction, and sufficient detection accuracy can be obtained.

(31) In addition, in the present embodiment, the movable side detection element 31 is constituted by the magnet or the brush disposed on the opposing surface 23a which is the side surface on the one end side in the tooth width direction of the control gear 23, while the fixed side detection element 32 is constituted by the Hall element or the resistance coating film, so that the position sensor 30 is compact and simple in the configuration, thereby making it possible to provide a compact throttle device 10 with a reduced full width W1.

(32) Thus, according to the present embodiment, the position sensor 30 does not need to protrude out of the range of the entire width of the throttle body as in the conventional art, so that the throttle device 10 can be made compact and the degree of freedom of arrangement can be increased. Therefore, the mountability of the engine 1, having the throttle device 10 provided therein, on a body frame of a two-wheeled vehicle can be improved.

(33) FIGS. 5A and 5B show conventional throttle devices 110, 120 applied to the four cylinders of the engine. In the figures, the gear transmission mechanisms 112, 122 and the position sensors 113, 123, which perform rotational transmissions from the motors 111, 121 to the throttle shaft (without a reference numeral), are disposed at both ends of the respective throttle shafts. In this case, the angular displacement of the throttle shaft can be directly detected by the position sensors 113, 123, and it is possible to exclude errors due to backlashes in a transmission path as in the case of providing a sensor on the side of the motors 111, 121. However, in this case, due to the existence of both throttle position sensors 113, 123 and the gear transmission mechanism 112, 122, the entire widths Wa1, Wb1 of the throttle devices 110, 120 become larger with respect to the entire width of the throttle body 115, 125, respectively by the widths of the gear transmission mechanism 112, 122 or the throttle position sensors 113, 123.

(34) In the throttle device of the present invention, by disposing a gear transmission mechanism and a position sensor, conventionally disposed on the end side of the throttle shaft, between the two throttle bodies, the entire width of the throttle device can be narrowed compared to the conventional throttle device, thereby contributing to the improvement of mountability of the throttle device to the engine. Further, by disposing the position sensor at the center of the throttle shaft, it is possible to ensure favorable detection accuracy without being affected by an accuracy error or the like due to twisting of the throttle shaft. Still further, by providing the gear transmission mechanism in a case that accommodates the throttle bodies, it is possible to narrow the full width W1, thereby improving the fitness of the throttle device to a two-wheeled vehicle.

(35) In the above-described embodiment, the throttle device is mounted on a four-cylinder engine, but the present invention is also applicable to a throttle device mounted on an engine of two or more cylinders. For example, in the case that the throttle device is mounted on a three-cylinder engine 1 as shown in FIG. 6, a throttle device 10A for two cylinders similar to the main portion of one embodiment as shown in FIG. 1 and a throttle device 10B having a third segment body 11t for one cylinder which is constituted by removing the throttle valve 13 on one side of the throttle device 10A and leaving a portion 14′ of the throttle shaft 14, can be mounted in combination. In this case as well, it is possible to suppress the whole width W2 of the engine 1, so that the arrangement of the throttle device in the body frame of the two-wheeled vehicle is easy, thereby improving the mountability.

(36) Although the rotation transmission mechanism 20 is exemplified by employing three gears, the number of gears may be arbitrary, and the rotation transmission elements may be other than gears. When a plurality of throttle devices 10 respectively for two cylinders are arranged in the cylinder arrangement direction, instead of disposing the motor 15 on one side in the left-right direction of the vehicle with respect to the rotation transmission mechanism 20 as shown in FIG. 2, the motor 15 may be arranged to be inverted on both sides in the left-right direction of the vehicle body, considering the center of gravity in relationship with other equipment.

(37) Further, in the present embodiment, the movable side detection element 31 and the fixed side detection element 32 of the position sensor 30 for detecting the throttle opening are opposed to each other in the tooth width direction of the control gear 23, but since a meshing teeth portion of the control gear 23 is formed only in a range sufficient for rotation position control of the throttle valve 13 and is not formed around the entire circumference, the movable side detection element 31 and the fixed side detection element 32 may be so arranged to oppose each other in the radial direction of the control gear 23 within a range of a predetermined angle on the missing tooth side.

(38) As described above, according to the present invention, it is not necessary to dispose the position sensor so as to protrude outside the entire width range of the throttle body, so that it is possible to achieve the effect that the throttle device can be miniaturized and the degree of freedom of arrangement of the throttle device can be increased, and thus the present invention is useful for a multilateral throttle device in general in which a plurality of throttle valves on the intake passage of an engine are controlled by an actuator in common.

EXPLANATION OF REFERENCE NUMERALS

(39) 1 engine 1a intake port 10 throttle device 11 unit body (throttle body) 11a throttle body portion (first throttle body) 11b throttle body portion (second throttle body) 11c gear cover portion 11d motor cover portion (accommodation portion) 11f first segment body (first throttle body) 11s second segment body (second throttle body) 12a, 12b intake passage 13a, 13b throttle valve 14 throttle shaft 15 motor (actuator) 16 torsion coil spring (urging unit) 20 rotation transmission mechanism 21 pinion (first transmission member, gear) 22 idler gear (gear) 23 control gear (second transmission member, gear) 23a opposing surface (one side surface, surface in the radial direction of the shaft) 30 position sensor (throttle position sensor) 31 movable side detection element (magnet or brush) 32 fixed side detection element (Hall element or resistance coating film) 41 fuel injection valve 42 fuel pipe D1 interval W1 full width