Throttling device for an engine

Abstract

The throttle device of the present application can reduce the occupied space in the axial direction of the throttle valve to achieve compact engine. The throttle device includes: a throttle device body, which supports the throttle valve in the throttle hole through the throttle valve shaft, and protrudes the throttle valve shaft on the outer side; a cover member, which divides the mechanism room containing the transmission mechanism with the outer side of the throttle device body; a motor, which is installed on the throttle device body, the rotation of the output shaft protruding into the mechanism room is transmitted to the throttle valve shaft through the transmission mechanism, and the amount of intake air flowing in the throttle hole is adjusted according to the opening and closing of the throttle valve; a throttle opening degree sensor, which is provided on the cover member and detects the rotation angle of the throttle valve shaft; and at least any one of an intake air temperature sensor and an intake air pressure sensor, the intake air temperature sensor is provided on the cover member and detects the temperature of the intake air, and the intake air pressure sensor is provided on the cover member and detects the pressure of the intake air.

Description

TECHNICAL FIELD

[0001] The present application relates to a throttle device of an engine. BACKGROUND

[0002] For example, Patent Literature 1 discloses a throttle device for a single cylinder engine, in which a throttle valve is supported by a throttle valve shaft so as to be opened and closed, in a single throttle hole formed in a throttle device main body. The throttle valve shaft protrudes from the throttle hole toward one side, and a recess is integrally formed in the throttle device main body so as to surround an end portion of the throttle valve shaft, and the recess is closed from the one side by a cover member, thereby dividing a gear housing chamber. A motor is installed at the throttle device main body in a posture in which an output shaft protrudes into the gear housing chamber, and rotation of the output shaft is transmitted to the throttle valve shaft via a gear train, and the amount of intake air flowing in the throttle hole is adjusted according to the opening and closing of the throttle valve.

[0003] A sensor unit including an intake air temperature sensor and an intake air pressure sensor is installed at the other side of the throttle device main body, in other words, at the side opposite to the gear housing chamber with the throttle device main body interposed therebetween. In detail, the intake air temperature sensor protrudes from the sensor unit, and a front end thereof protrudes into the throttle hole through the throttle device main body, and detects the temperature of intake air flowing in the throttle hole. Further, a pressure passage is formed in the throttle device main body, and the intake air pressure sensor communicates with the inside of the throttle hole via the pressure passage, and detects the pressure of intake air flowing in the inside.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Laid-Open No. 2019-132202 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] Such a throttle device is installed in a vehicle in a state of being installed in an engine, and therefore, in order to prevent interference with auxiliary equipment and the like of the engine, compactness is required. For example, the throttle device for a single cylinder engine described in Patent Literature 1 is installed in a bicycle with a prime mover and the like, in which a fuel tank, a vehicle body frame, and the like are provided around the throttle device, and therefore, compactness is particularly required.

[0009] In the throttle device described in Patent Literature 1, in addition to the throttle device main body which functions to adjust the amount of intake air as it is, a gear housing chamber in which a gear train is housed is divided at one side thereof, and a sensor unit including an intake air temperature sensor and an intake air pressure sensor is installed at the other side. As a result, the occupied space of the entire throttle device in the throttle valve axis direction increases, and therefore, a countermeasure for compactness has been required in the past.

[0010] The present application has been made to solve the above problems, and has an object to provide a throttle device of an engine which can reduce the occupied space in the direction of the axis of the throttle valve to achieve compactness.

[0011] Technical solution adopted to solve the technical problem

[0012] To achieve the above object, the throttle device of the present application includes: a throttle device main body which is formed with a throttle hole that communicates with the cylinder in a state of being mounted to the engine, a throttle valve is supported to be able to open and close in the throttle hole by a throttle valve shaft, and the throttle valve shaft protrudes from the outer side toward one side; a cover member which closes the outer side of the throttle device main body from one side, and divides a mechanism chamber in which a transmission mechanism is accommodated between the cover member and the outer side; a motor which is mounted to the throttle device main body, and the rotation of an output shaft that protrudes into the mechanism chamber is transmitted to the throttle valve shaft via the transmission mechanism, and the amount of intake air that flows in the throttle hole is adjusted according to the opening and closing of the throttle valve; a throttle opening degree sensor which is provided to the cover member, and detects the rotation angle of the throttle valve shaft as the throttle opening degree; an intake air temperature sensor which is provided to the cover member and detects the temperature of the intake air that flows in the throttle hole; and an intake air pressure sensor which is provided to the cover member and is connected to the inside of the throttle hole via a pressure passage, the pressure passage is formed by a tube that is provided to extend from the cover member toward the throttle hole and a through hole that is formed in the throttle device main body (Technical Solution 1).

[0013] As another aspect, the through hole is opened on the downstream side of the throttle valve in the throttle hole, the tube is integrally formed on the inner side of the cover member and the base end is connected to the intake air pressure sensor, and the tube is provided to extend toward the throttle hole and is inserted into the through hole, the tip end reaches the middle of the through hole, the inside of the through hole and the tube are continuous with each other and form the pressure passage (Technical Solution 2).

[0014] As another aspect, an O-ring is interposed between the base end of the tube and the throttle device main body (Technical Solution 3).

[0015] As another aspect, it is also possible that the throttle opening degree sensor is arranged on the axis of the throttle valve shaft in the mechanism chamber, and at least either one of the intake air temperature sensor and the intake air pressure sensor is arranged in the area around the throttle opening degree sensor on the cover member (Technical Solution 4).

[0016] As another aspect, it is also possible that at least either one of the intake air temperature sensor and the intake air pressure sensor is arranged in the area on the side opposite to the transmission mechanism with the throttle opening degree sensor as a reference (Technical Solution 5).

[0017] As other modes, the intake air temperature sensor can be provided extending from the cover member toward the throttle hole, and the tip end can be made to project into the throttle hole via a through-hole formed in the throttle device main body (claim 6).

[0018] As other modes, the tip end of the intake air temperature sensor can be made to project to the upstream side of the throttle valve in the throttle hole, and the intake air temperature sensor can be disposed on the cover member at a position corresponding to the upstream side in the intake air flow direction, and the intake air pressure sensor can be disposed at a position corresponding to the downstream side in the intake air flow direction (claim 7).

[0019] As other modes, at least either one of the intake air temperature sensor and the intake air pressure sensor and the throttle valve opening degree sensor can be electrically connected via a common substrate provided in the cover member and a common connector provided on one side of the cover member, and the respective detection signals can be output to a control device that controls the operation of the engine via the substrate and the connector (claim 8).

[0020] As other modes, the throttle device main body can be formed with a single throttle hole, and the throttle device can be installed in a single-cylinder engine that is installed in a straddle-type vehicle as a traveling power source (claim 9).

[0021] According to the throttle device of the present application, the occupied space in the throttle valve axis direction can be reduced to achieve compactness. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a perspective view of a throttle device according to an embodiment.

[0023] Figure 2 is a perspective view of a gear cover removed from a throttle device main body to show a gear train in a gear housing chamber.

[0024] Figure 3 is a perspective view of a gear cover removed from a throttle device main body to show the inner side surface of the gear cover.

[0025] Figure 4 is an exploded perspective view showing the relationship of a motor, a gear train, and a throttle valve shaft.

[0026] Figure 5 is a view showing the arrangement of a gear train and sensors in a gear housing chamber.

[0027] Figure 6 is a view showing the relationship of a motor, a gear train, and a throttle valve shaft and the arrangement of a throttle valve opening degree sensor. Figure 5 VI-VI line sectional view of Fig.

[0028] Figure 7 is an exploded perspective view showing the relationship of a gear cover and a sensor unit embedded in the gear cover.

[0029] Figure 8 is an exploded perspective view showing the relationship of the gear cover with the sensor unit embedded in the gear cover, from another angle.

[0030] Figure 9 is a IX-IX sectional view of FIG. 1 showing the state in which the intake air temperature sensor is embedded in the gear cover. Figure 5

[0031] Figure 10 is a X-X sectional view of FIG. 1 showing the state in which the intake air pressure sensor is embedded in the gear cover. Figure 5

[0032] Figure 11 is a perspective view showing another example in which the connector is directed rearward.

[0033] Figure 12 is a perspective view showing another example in which the connector is directed downward.

[0034] Figure 13 is a perspective view showing another example in which the connector is directed rightward.

[0035] (Symbol explanation)

[0036] 1 throttle device

[0037] 2 throttle hole

[0038] 3 throttle valve shaft

[0039] 4 throttle valve

[0040] 5 throttle device main body

[0041] 6 gear housing chamber (mechanism chamber)

[0042] 7 gear cover (cover member)

[0043] 8 gear train (transmission mechanism)

[0044] 9 motor

[0045] 9a output shaft

[0046] 21 throttle valve opening sensor

[0047] 22 intake air temperature sensor

[0048] 23 intake air pressure sensor

[0049] 37 seal tube

[0050] 38 through hole

[0051] 41 communication tube (pipe)

[0052] 43 O-ring​​

[0053] 44 pressure passage

[0054] 26 substrate

[0055] 34, 51-53 connectors DETAILED DESCRIPTION

[0056] Hereinafter, an embodiment in which the present application is embodied as a throttle device for a single-cylinder engine mounted on a bicycle with a prime mover as a traveling power source will be described.

[0057] The throttle device 1 is mounted on an engine not shown, and functions to adjust the amount of intake air supplied to the cylinder of the engine in accordance with the throttle operation by the driver. As shown in Figures 1-3 , the throttle device 1 is composed of, as a whole, a throttle device main body 5 in which a throttle valve 4 is supported by a throttle valve shaft 3 so as to be openable and closable within a single throttle hole 2 communicating with the cylinder of the engine, a gear cover 7 which divides a gear housing chamber 6 between the throttle device main body 5, and a motor 9 which transmits the rotation of an output shaft 9a protruding into the gear housing chamber 6 to the throttle valve shaft 3 via a gear train 8 to open and close the throttle valve 4. In the present embodiment, the gear housing chamber 6 corresponds to the mechanism chamber of the present application, the gear cover 7 corresponds to the cover member of the present application, and the gear train 8 corresponds to the transmission mechanism of the present application.

[0058] The throttle device 1 of the present embodiment is mounted on a vehicle in the posture shown in Figure 1 . According to this posture, in the following description, the intake air flow passage direction along the axis Cb of the throttle hole 2 will be referred to as the front-rear direction, the throttle valve axis direction along the axis Cth of the throttle valve shaft 3 orthogonal to the front-rear direction will be referred to as the left-right direction, and the gear train direction in which the gear train 8 is arranged orthogonal to both of the above directions will be referred to as the up-down direction. Of course, the mounting posture of the throttle device 1 is not limited to this, and can be changed to various postures.

[0059] (throttle device main body 5)

[0060] As shown in Figure 4 , Figure 6A throttle hole 2 is provided through the throttle device main body 5 in the front-rear direction, and a motor housing chamber 10 housing the motor 9 is integrally formed adjacent to the lower side of the throttle hole 2. The throttle device main body 5 is connected to the intake manifold of the engine via a flange 11 formed at the rear end of the throttle hole 2 by bolts not shown, and an air cleaner not shown is connected to the front end of the throttle hole 2. The throttle valve shaft 3 is disposed so as to pass through the throttle hole 2 in the throttle device main body 5, and is rotatably supported by a pair of bearings 12. In the throttle hole 2, the throttle valve 4 is fixed to the throttle valve shaft 3 by a pair of small screws 13, and during operation of the engine, the throttle valve 4 is opened and closed in conjunction with rotation of the throttle valve shaft 3 to regulate the amount of intake air passing through the throttle hole 2.

[0061] (Gear housing chamber 6)

[0062] The throttle valve shaft 3 extends toward the right within the throttle device main body 5, and its end portion protrudes outward from the right side surface of the throttle device main body 5. A recessed portion 14 that opens to the right is formed in the entire right side surface of the throttle device main body 5. The end portion of the throttle valve shaft 3 is surrounded by the recessed portion 14, and the output shaft 9a of the motor 9 also protrudes into the recessed portion 14. A gear cover 7 that is recessed to open to the left is disposed at the recessed portion 14 of the throttle device main body 5, and the periphery of the gear cover 7 overlaps the periphery of the recessed portion 14 via a seal not shown and is fastened by four small screws 15. The recessed portion 14 is closed by the gear cover 7, and a gear housing chamber 6 that is shaped so as to extend in the up-down direction is partitioned between the gear cover 7 and the recessed portion 14.

[0063] A gear train 8 is provided between the output shaft 9a of the motor 9 and the throttle valve shaft 3 within the gear housing chamber 6. The gear train 8 is composed of a drive gear 16 fixed to the output shaft 9a of the motor 9, a driven gear 18 fixed to the throttle valve shaft 3, and an intermediate gear 17 provided between the drive gear 16 and the driven gear 18, and each of the gears 16 to 18 is disposed side by side in the up-down direction. The intermediate gear 17 is rotatably supported by a gear shaft 19 that is erected between the throttle device main body 5 and the gear cover 7, and a large-diameter portion 7a that engages with the drive gear 16 and a small-diameter portion 17b that engages with the driven gear 18 are integrally formed. Within the gear housing chamber 6, a return spring 20 is wound around the throttle valve shaft 3, although not shown, one end of which is hooked to the throttle device main body 5 side and the other end of which is hooked to the throttle valve shaft 3.

[0064] The throttle valve 4 is urged toward a prescribed opening degree, such as a fully closed position, and the like, by the force of the return spring 20. Furthermore, when the motor 9 operates, the rotation of the output shaft 9a is transmitted to the large-diameter portion 17a of the intermediate gear 17 and is decelerated, and further is transmitted to the driven gear 18 from the small-diameter portion 17b of the intermediate gear 17 and is decelerated, and the throttle valve shaft 3 is rotated against the force of the return spring 20 to open and close the throttle valve 4 as described above.

[0065] Furthermore, the butterfly-type throttle valve 4 has an opening and closing angle range of slightly less than 90° between fully open and fully closed, causing the driven gear 18 to rotate within the same angle range via the throttle valve shaft 3. Therefore, the driven gear 18 has a toothed sector shape formed only in the area required for meshing with the small-diameter portion 17b of the intermediate gear 17. However, the structure of the gear train 8 is not limited to this; as long as the rotation of the motor 9's output shaft 9a is transmitted to the throttle valve shaft 3 while simultaneously reducing speed, the number of gears and their configuration can be arbitrarily changed.

[0066] As described above, in the throttling device 1 of this embodiment, in addition to the throttling device body 5 which originally functions to regulate the intake air volume, a gear housing chamber 6 is provided on its right side to house the gear train 8 used for motor drive, which is the same as the technology in Patent Document 1. Furthermore, in order to control the engine, the throttling device 1 includes an intake air temperature sensor that detects the temperature of the intake air flowing in the throttling orifice 2 and an intake air pressure sensor that detects the pressure of the intake air, which is also the same as in Patent Document 1. Therefore, assuming that each sensor is installed on the left side of the throttling device body 5, in other words, on the side opposite to the gear housing chamber 6 that sandwiches the throttling device body 5, as described in the "Technical Problem to be Solved by the Invention," a problem arises where the space occupied by the throttling device 1 in the left-right direction increases.

[0067] In view of the above-mentioned undesirable conditions, the inventors focused on a gear cover 7 that divides the gear housing chamber 6 between the throttling device body 5 and the gear housing 6. Such motor-driven throttling devices 1 sometimes include a throttling valve opening sensor; in this embodiment, a magnetic throttling valve opening sensor 21 is also housed within the gear housing chamber 6 along with the gear train 8. To detect the throttling valve opening as the rotation angle of the throttling valve shaft 3, the throttling valve opening sensor 21 is as follows: Figure 6 The throttle valve is positioned on the axis Cth within the gear housing 6, as shown, in an orientation opposite to the driven gear 18.

[0068] As a result, the throttle opening sensor 21 is positioned between the driven gear 18 and the inner side of the gear cover 7. To ensure sufficient space for its installation, the gear cover 7 originally had a cross-sectional shape that separated from the driven gear 18 to the right. Therefore, a dead zone is formed on the gear cover 7, especially around the throttle opening sensor 21, providing room for the installation of an intake air temperature sensor and an intake air pressure sensor.

[0069] Based on the above understanding, in this embodiment, the intake air temperature sensor 22 and the intake air pressure sensor 23 are installed together with the throttle valve opening sensor 21 at the gear cover 7. The sensors 21 to 23 will be described in detail below; before that, the overall structure of the gear cover 7 will be described.

[0070] (The overall structure of gear cover 7)

[0071] As shown in Figure 2 , Figure 3 , the gear cover 7 is injection molded of synthetic resin material, and each of the components and sensors 21 to 23, the substrate 26, the relay terminal 30, the connector terminals 31 and 32, and the like are embedded in the gear cover 7 and the resin seal 24 formed by resin sealing at the time of the insert molding and after the molding. Hereinafter, the assembly of each of the components and sensors 21 to 23, the substrate 26, the relay terminal 30, the connector terminals 31 and 32, and the like other than the gear cover 7 and the resin seal 24 will be referred to as the sensor unit 25. Further, the term "gear cover 7" can be used in the sense of the completed state including the sensor unit 25 and the resin seal 24, or in the sense of the single member other than them.

[0072] Figure 2 , Figure 3 Fig. 7 shows the gear cover 7 in the completed state in which the sensor unit 25 is embedded by the insert molding and the resin sealing, Figure 7 , Figure 8 Fig. 8 shows the state in which the sensor unit 25 and the resin seal 24 are separated from the gear cover 7. Note that Figure 7 , Figure 8 the separated state shown in Fig. 8 is not generated in the actual manufacturing process of the gear cover 7, but is shown for the convenience of understanding.

[0073] (Sensor Unit 25)

[0074] First, the relationship of each component constituting the sensor unit 25 will be described based on Figure 7 , Figure 8 . The substrate 26 is substantially quadrangular, and each of the sensors 21 to 23 is connected to the left side surface thereof. In detail, the sensor main body 27 of the throttle opening sensor 21 is disposed at substantially the center of the left side surface of the substrate 26, and six Hall devices 27b are arranged between a pair of holders 27a above and below the sensor main body 27, and the terminals 27c of each of the Hall devices 27b are connected to the substrate 26. The sensor main body 27 constitutes the throttle opening sensor 21 in opposition to the magnetic field generating portion 36 provided on the driven gear 18, which will be described later in detail.

[0075] A pair of terminals 28a of the intake air temperature sensor 22 are connected to the upper front side of the substrate 26, and each of the terminals 28a is extended to the left and supports the sensor main body 28 at the front end. In the state in which the gear cover 7 is combined with the throttle device main body 5, the sensor main body 28 protrudes into the throttle hole 2 and can detect the temperature of the intake air, which will be described later in detail.

[0076] A sensor main body 29 of an intake air pressure sensor 23 is arranged on the upper rear side of the substrate 26, and three terminals 29a thereof are connected to the substrate 26. In a state where the gear cover 7 is combined with the throttle device main body 5, the sensor main body 29 is able to detect the pressure of intake air in communication with the inside of the throttle hole 2 via the pressure passage 44, as will be described later in detail.

[0077] The upper ends of six relay terminals 30 in total are connected to the lower portion of the substrate 26, and each relay terminal 30 is in a short rod shape and extends downward, and the upper end of a connector terminal 31 is connected to the lower end of each relay terminal 30. Each connector terminal 31 is electrically connected to the terminals 27c, 28a, 29a of each sensor 21 to 23 via the corresponding relay terminal 30 and a not-shown wiring pattern formed on the substrate 26. Each connector terminal 31 is arranged while being bent and extending downward, and the lower end of each is arranged together with two connector terminals 32 extending from the motor 9, and is arranged in a terminal housing portion 33 integrally formed on one side of the gear cover 7 after injection molding of the gear cover 7 and constitutes a connector 34.

[0078] Although not shown, a vehicle body side connector is connected at the connector 34 in a state where the throttle device 1 is installed in the vehicle body, and the throttle device 1 is electrically connected to an ECU installed in the vehicle body via the vehicle body side connector and a wire harness. The above-mentioned ECU corresponds to the "control device that controls the operation of the engine" of the present application. Furthermore, during the operation of the engine, power is supplied from the ECU to the motor 9 and each sensor 21 to 23 via the wire harness, the vehicle body side connector, the connector terminals 31, 32, the relay terminals 30, and the substrate 26, and the detection signals output from each sensor 21 to 23 are input to the ECU along a path opposite to the above-mentioned path. In this way, the substrate 26, the relay terminals 30, and the terminals 30, 31 function as relays of power and detection signals between each sensor 21 to 23 and the motor 9 and the ECU, but the above-mentioned structure is not limited thereto and can be arbitrarily changed.

[0079] (Sensor unit 25 buried in gear cover 7)

[0080] Next, a state in which the sensor unit 25 configured as described above is buried in the gear cover 7 will be described. In addition, each component of the sensor unit 25 configured as described above is sequentially buried in the gear cover 7 through injection molding of the gear cover 7 and sealing resin after molding, but in the following description, a state in which all components are buried in the gear cover 7 and the combination with the throttle device main body 5 is also completed will be described.

[0081] (Substrate 26 and terminals 30, 31, 32)

[0082] As Figures 5-7As shown, a resin filling frame 35, which is a substantially quadrangular shape and opens to the right, is integrally formed on the upper portion of the outer side surface of the gear cover 7, and the substrate 26 is disposed inside the resin filling frame 35 from the right. The resin filling frame 35 is filled with synthetic resin, and the substrate 26 and each relay terminal 30 are sealed inside the resin seal 24 formed by curing the synthetic resin. Each connection terminal 31, 32 is embedded in the gear cover 7, and each lower end is disposed in the terminal housing portion 33 of the gear cover 7 as described above to constitute the connector 34. In the present embodiment, the terminal housing portion 33 is opened to the front, and the connector 34 is directed to the front, in other words, to the air cleaner side. This is based on the idea that, in a state in which the throttle device 1 is attached to the vehicle body, there is a spatial margin on the air cleaner side, it is easy to connect the vehicle body side connector from the front, and interference between the throttle device 1 and the surrounding components can be easily prevented.

[0083] (throttle opening degree sensor 21)

[0084] As Figure 5 , Figure 6 shown, the sensor main body 27 of the throttle opening degree sensor 21 is embedded in the inner side surface of the gear cover 7, whereby the inner side surface of the gear cover 7 is made cylindrical corresponding to the sensor main body 27 and protrudes to the left. Figure 5 The positional relationship of each sensor 21 to 23 is shown without the gear cover 7, and in a state in which the gear cover 7 is combined with the throttle device main body 5, the sensor main body 27 is positioned slightly apart from the right side surface of the driven gear 18.

[0085] The magnetic field generating portion 36 of the throttle opening degree sensor 21 is provided to the right side surface of the driven gear 18. In detail, the magnetic field generating portion 36 is integrally formed to the right side surface of the driven gear 18 in a ring shape centered on the throttle axis Cth in a manner of surrounding the sensor main body 27, and a plurality of magnets 36a are embedded at equal intervals in the circumferential direction.

[0086] Since the principle of the magnetic throttle opening degree sensor 21 is well known, only a general description will be given. When a current flows through the Hall device 27b in the magnetic field generated by the magnets 36a and the magnetic field generating portion 36 and the throttle shaft 3 are rotated together, a potential difference caused by the Lorentz force is generated at the Hall device 27b according to the rotation angle. The above-mentioned potential difference is converted into an electric signal related to the rotation angle of the throttle shaft 3 and output.

[0087] Furthermore, the throttle valve opening sensor 21 is not limited to a magnetic type; it can employ components based on various principles, such as an inductive sensor. Since the principle of this sensor is as well-known as that of a magnetic sensor, it will not be described in detail. For example, a retainer including an excitation conductor is fixed to the right side of the driven gear 18, and a base plate including an excitation conductor and a signal detection conductor is disposed on the gear cover 7 opposite to the retainer. When the driven gear 18 and the throttle valve shaft 3 rotate together, the excitation conductor on the retainer is energized with current according to the alternating current flowing through the excitation conductor of the base plate. This energized current then energizes the signal detection conductor of the base plate with alternating current, which is then converted into an electrical signal related to the rotation angle of the throttle valve shaft 3 and output.

[0088] In this embodiment, the positional relationship is as follows: As described above, a sensor body 27 is embedded on the inner side of the gear cover 7, and a magnetic field generating part 36 is integrally formed on the right side of the driven gear 18, surrounding the sensor body 27. Furthermore, since the resin seal 24 of the sealing substrate 26 is located to the right of the sensor body 27, the result is that, in order to install the throttle valve opening sensor 21, it is used in the left-right direction... Figure 6 The region represented by the dimension L.

[0089] When the throttle valve opening sensor 21 is not included, the sealing resin member 24 can be further configured close to the right side of the driven gear 18. However, since an area of ​​size L is required for mounting the throttle valve opening sensor 21, the original thickness of the gear cover 7 in the left-right direction is increased. Therefore, a dead zone is formed on the gear cover 7, especially in the area around the throttle valve opening sensor 21. In addition, since inductive sensors also require space for the mounting of retaining members and substrates, the same result occurs.

[0090] Therefore, the intake air temperature sensor 22 and the intake air pressure sensor 23 are configured using the dead zone formed by the setting of the throttle valve opening sensor 21 as described above.

[0091] (Intake air temperature sensor 22)

[0092] like Figure 8 , Figure 9 As shown, the intake air temperature sensor 22 is entirely embedded within the gear cover 7 via a resin seal 24. Specifically, a pair of terminals 28a of the intake air temperature sensor 22 extend to the left from the substrate 26 sealed within the resin-filled frame 35 of the gear cover 7, with the sensor body 28 supported at its front end. An elongated sealing tube 37 is integrally formed from the inner side of the gear cover 7 and extends to the left, housing the sensor body 28 and terminals 28a as described above. Its front end is sealed, and the sensor body 28 is disposed internally within it.

[0093] The synthetic resin filling the resin filling frame 35 also enters the sealing tube 37 and cures to form a resin seal 24, which seals the sensor body 28 and the terminal 28a within the sealing tube 37 to form the intake air temperature sensor 22. As a result, the intake air temperature sensor 22 has an elongated shape that extends to the left from the gear cover 7 and reaches the throttle orifice 2.

[0094] With the gear cover 7 and the throttling device body 5 engaged, an intake air temperature sensor 22 is inserted into the through hole 38 formed in the throttling device body 5, and an O-ring 39 is sandwiched between the base of the intake air temperature sensor 22 and the throttling device body 5. The front end of the intake air temperature sensor 22 protrudes towards the front of the throttling valve 4 in the throttling hole 2, and the temperature of the intake air flowing in the throttling hole 2 is transmitted to the sensor body 28 embedded inside. Specifically, the sensor body 28 is sealed with a double layer of synthetic resin forming a sealing tube 37 and a resin seal 24. The temperature of the intake air is effectively transmitted to the sensor body 28 through the tightly fitted synthetic resin, thus improving its detection sensitivity and responsiveness. For example, as the intake air temperature sensor 22, a thermistor whose resistance changes with temperature can be used to convert the resistance change into an electrical signal related to the intake air temperature and output it.

[0095] (Intake pressure sensor 23)

[0096] like Figure 8 , Figure 10 As shown, an intake pressure sensor 23 is embedded in the gear cover 7. Specifically, the intake pressure sensor 23 is embedded in the gear cover 7 near the substrate 26 sealed within the resin-filled frame 35. A pressure chamber 40 is formed in the gear cover 7 to the left of the intake pressure sensor 23 and communicates with it. An elongated connecting tube 41 is integrally formed from the inner side of the gear cover 7 and extends to the left, with its front end open and its base communicating with the pressure chamber 40. This connecting tube 41 corresponds to the "tube" of this invention.

[0097] With the gear cover 7 and the throttling device body 5 engaged, a connecting pipe 41 is inserted into the through hole 42 formed in the throttling device body 5, and an O-ring 43 is sandwiched between the base end of the connecting pipe 41 and the throttling device body 5. The through hole 42 opens at the rear side of the throttling valve 4 in the throttling orifice 2, and the front end of the connecting pipe 41 reaches the middle of the through hole 42. The interiors of the through hole 42 and the connecting pipe 41 are continuous and form a pressure passage 44 extending in the left-right direction, through which the throttling orifice 2 and the intake pressure sensor 23 are connected.

[0098] Therefore, the pressure of intake air flowing in the throttle hole 2 acts on the sensor body 29 of the intake air pressure sensor 23 via the pressure passage 44 and the pressure chamber 40. The sensor body 29 is firmly held in position because it is embedded in the gear cover 7, so even if it is subjected to pressure, it does not displace in position, thereby exerting the desired detection function.

[0099] For example, as the intake air pressure sensor 23, a semiconductor pressure sensor, a strain gauge pressure sensor, or the like can be used. The principle of the above pressure sensors is well known, so a detailed description will not be given, but the semiconductor pressure sensor causes pressure to act on a diaphragm pressure receiving surface formed of a silicon gauge, converts a resistance change (piezoresistive effect) resulting from the deflection of the silicon gauge corresponding to the pressure into an electric signal related to the intake air pressure, and outputs it. Further, the strain gauge pressure sensor causes pressure to act on a metal diaphragm to which a resistance bridge is attached on the back surface, converts a voltage change of the resistance bridge corresponding to the deflection of the metal diaphragm into an electric signal related to the intake air pressure, and outputs it.

[0100] The production of the gear cover 7 configured as described above is performed in the order of injection molding and sealing of the resin after molding, at this time, the embedding of each component configuring the sensor unit 25 is performed in the following steps. In addition, this production process is an example, and the contents thereof can of course be arbitrarily changed.

[0101] First, when injection molding of the gear cover 7 is performed, the sensor body 27 of the throttle opening degree sensor 21, the intake air pressure sensor 23, and each connector terminal 31, 32 are embedded in the gear cover 7. Next, the terminal 28a of the intake air temperature sensor 22 is soldered at the substrate 26 in advance, and while the sensor body 28 and the terminal 28a are inserted into the sealing tube 37 of the gear cover 7, the substrate 26 is disposed at a prescribed position within the resin filling frame 35. Naturally, the terminal 27c of the sensor body 27 of the throttle opening degree sensor 21 and the terminal 29a of the intake air pressure sensor 23 are inserted into the through hole of the substrate 26, and each insertion site is soldered. Further, a relay terminal 30 is disposed in a state of being bridged between the substrate 26 and the upper end of each connector terminal 31, and the upper end of each relay terminal 30 is connected to the substrate 26 and the lower end of each relay terminal 30 is connected to the connector terminal 31 by riveting or the like. Thus, the substrate 26 and each connector terminal 31 are electrically connected via each relay terminal 30.

[0102] After that, the gear cover 7 is held in a posture in which the outer side surface faces upward, and synthetic resin is caused to flow into the resin filling frame 35 which opens upward. The synthetic resin is filled in the resin filling frame 35, and also enters the sealing tube 37 and is cured as a resin seal 24. Thus, the substrate 26 and each relay terminal 30 are sealed within the resin filling frame 35, and the sensor body 28 and the terminal 28a are sealed within the sealing tube 37 to form the intake air temperature sensor 22, and the production of the gear cover 7 is completed.

[0103] Next, taking the throttle valve opening sensor 21 as a reference, the configuration of the intake air temperature sensor 22 and the intake air pressure sensor 23, which are embedded in the gear cover 7 as described above, will be explained.

[0104] Based on Figure 6 As described, in order to ensure that the throttle valve opening sensor 21 is embedded in the area of ​​dimension L of the gear cover 7, the thickness of the gear cover 7 in the left and right directions is increased. As a result, a dead zone is formed on the gear cover 7, especially in the area around the throttle valve opening sensor 21.

[0105] In addition, such as Figure 5 As shown, with the throttle valve opening sensor 21 as a reference, the intake air temperature sensor 22 is positioned above and in front, and the intake air pressure sensor 23 is positioned above and behind. All positions are contained within the dead zone surrounding the throttle valve opening sensor 21. Therefore, two sensors 22 and 23 can be embedded within the gear cover 7 with almost no increase in thickness. As a result, the throttle valve opening sensor 21, the intake air temperature sensor 22, and the intake air pressure sensor 23, which should be included in the throttle device 1, are all centrally located within the gear cover 7.

[0106] In the throttling device of Patent Document 1, a gear housing chamber is provided on one side of the throttling device body, and a sensor unit consisting of an intake air temperature sensor and an intake air pressure sensor is provided on the other side. However, in this embodiment, the function of the aforementioned sensor unit is achieved by the gear cover 7. As a result, in this embodiment, the space occupied by the throttling device 1 in the left-right direction can be reduced by an amount equivalent to the left-right thickness of the sensor unit, thereby achieving compactness. In particular, the throttling device 1 of this embodiment is installed on a bicycle with a small frame and a prime mover, and not only are auxiliary equipment such as the engine located around it, but also the fuel tank, the frame, etc. Therefore, if the throttling device 1 is not sufficiently compact, there may be situations where countermeasures on the frame side are required to avoid interference, but such adverse situations can be prevented.

[0107] In addition, since no component equivalent to the gear unit in Patent Document 1 is required, the number of parts can be reduced and the overall structure of the throttling device 1 can be simplified, which is the main reason for reducing manufacturing costs.

[0108] Furthermore, the configuration of the intake air temperature sensor 22 and the intake air pressure sensor 23 as described above is also excellent in the following aspects.

[0109] like Figure 5As shown, the driven gear 18 is fan-shaped and rotates counterclockwise around the throttle valve axis Cth from the position shown in the figure. Its rotation range is a value obtained by adding a margin to the less than 90° required for the opening and closing of the throttle valve 4. The intake air temperature sensor 22 and intake air pressure sensor 23 can also be arranged within the rotation range of the driven gear 18. However, in this case, measures such as offsetting the sensors 22 and 23 from the driven gear 18 in the left-right direction are required to prevent interference. However, the measures described above result in an increase in the thickness of the gear cover 7, which becomes a major obstacle to the compactness of the throttle device 1.

[0110] The positions above and in front of the throttle valve opening sensor 21, as well as the positions above and behind it, correspond to positions outside the rotation range of the driven gear 18. Therefore, by arranging the intake air temperature sensor 22 and the intake air pressure sensor 23 at various locations, the increase in the thickness of the gear cover 7 caused by measures to prevent interference with the driven gear 18 can be prevented, thereby further reliably achieving a compact throttle device 1. The positions above and in front of the throttle valve opening sensor 21, and the positions above and behind it, indicating the locations of the sensors 22 and 23, correspond to the "area on the side opposite to the transmission mechanism based on the aforementioned throttle valve opening sensor 21" in this invention.

[0111] In addition, by configuring the sensors 22 and 23 as described above, it is also possible to easily configure the pressure passage 44 of the intake air temperature sensor 22 and the intake air pressure sensor 23 within the main body 5 of the throttling device.

[0112] That is, such as Figure 9 As shown, the intake air temperature sensor 22 is preferably linear in shape so that the sensor body 28 and terminal 28a can be inserted into the sealing tube 37. Furthermore, from the viewpoint of pressure transmission, as... Figure 10 As shown, the pressure passage 44 of the intake pressure sensor 23 is preferably a straight shape compared to a complex, curved shape. Furthermore, from the structural viewpoint of the throttling device body 5, a simple straight shape is also preferred. On the other hand, as... Figure 6 As shown, a return spring 20 is wound around the throttle valve shaft 3 inside the throttle body 5, and a gear shaft 19 supporting the intermediate gear 17 and other components are arranged below it. Therefore, it is necessary to set the intake air temperature sensor 22 and the pressure passage 44 in a way that avoids these components.

[0113] When the straight linear intake air temperature sensor 22 is provided extending to the left from the front side position on the gear cover 7 as described above, the intake air temperature sensor 22 is positioned above and in front of the return spring 20 within the throttle device body 5 to prevent interference, and also does not interfere with the gear shaft 19 and the like positioned further below. Similarly, when the straight linear pressure passage 44 is provided extending to the left from the intake air pressure sensor 23 on the rear side position on the gear cover 7, the pressure passage 44 is positioned above and in the rear of the return spring 20 within the throttle device body 5 to prevent interference, and also does not interfere with the gear shaft 19 and the like positioned further below. As a result, the following effects can be obtained: on the basis of the intake air temperature sensor 22 and the pressure passage 44 being provided in the straight linear shape that is functionally preferable, they can be easily disposed without interfering with other components within the throttle device body 5.

[0114] Further, the disposition of the intake air temperature sensor 22 on the front side and the intake air pressure sensor 23 on the rear side as described above is also reasonable from the viewpoint of appropriately detecting the intake air temperature and the intake air pressure. That is, as is well known, the intake air temperature requires the intake air immediately after being introduced into the throttle hole 2, in other words, the intake air on the upstream side of the throttle valve 4, as the detection object. Further, the intake air pressure requires the intake air that passes through the throttle valve 4 and generates negative pressure, in other words, the intake air on the downstream side of the throttle valve 4, as the detection object. In order to satisfy the above requirements, it is necessary to project the front end of the intake air temperature sensor 22 to the upstream side of the throttle valve 4, in other words, to the front side position within the throttle hole 2, and to open the pressure passage 44 to the downstream side of the throttle valve 4, in other words, to the rear side position.

[0115] When the front and rear relationship of the intake air temperature sensor 22 and the intake air pressure sensor 23 is reversed with respect to the present embodiment, it is necessary to cross-dispose the straight linear intake air temperature sensor 22 and the pressure passage 44 within the throttle device body 5, or to provide them in a complexly curved shape, which in either case results in the throttle device body 5 being structurally complicated. In the present embodiment, the front and rear relationship of each sensor 22, 23 on the gear cover 7 is set in correspondence with the positional relationship of the intake air flow direction required by the intake air temperature sensor 22 and the pressure passage 44. Specifically, the intake air temperature sensor 22 is disposed on the front side, in other words, on the "position corresponding to the upstream side of the intake air flow direction" of the present invention, and the intake air pressure sensor 23 is disposed on the rear side, in other words, on the "position corresponding to the downstream side of the intake air flow direction" of the present invention.

[0116] Therefore, the following other effects can also be achieved: on the basis of the intake air temperature sensor 22 and the pressure passage 44 being maintained in the straight linear shape and the desired intake air before and after the throttle valve 4 being taken as the detection object, the structural complication of the throttle device body 5 can be avoided.

[0117] In addition, when the front-rear relationship of the two sensors 22, 23 on the gear cover 7 is set as described above, it is not necessary to provide the intake temperature sensor 22 and the pressure passage 44 in a straight line shape. This is because, since the mutually crossing arrangement within the throttle body 5 is avoided, even if not a straight line shape, for example, it is a simpler shape than when crossing, contributing to the simplification of the structure of the throttle body 5.

[0118] On the other hand, the throttle opening sensor 21, the intake temperature sensor 22, and the intake pressure sensor 23 are electrically connected to the vehicle body side via the substrate 26, the relay terminals 30, and the connector terminals 31 for the supply of electric power from the ECU and the output of detection signals to the ECU. Further, the terminals 27c, 28c, 29a of each sensor 21 to 23 are connected to the common substrate 26, and the substrate 26 is connected to the common connector 34 via each relay terminal 30 and each connector terminal 31. As a result, each sensor 21 to 23 and the ECU achieve the exchange of electric power and detection signals via the common substrate 26 and the connector 34.

[0119] When the substrate 26 and the connector 34 are provided on the gear cover 7 for each sensor, the arrangement of each sensor 21 to 23 itself or the arrangement of other components such as the gear train 8, which should also be provided on the gear cover 7, is restricted, and, due to the increase in the number of components, it is also disadvantageous in terms of manufacturing cost. By commonizing the substrate 26 and the connector 34, the limited space on the gear cover 7 can be effectively utilized, and furthermore, the degree of freedom of the arrangement of each sensor 21 to 23, the gear train 8, and the like on the gear cover 7 can be increased, and the number of components can be further reduced to achieve cost reduction.

[0120] The description of the embodiments has been completed, but the modes of the present application are not limited to the above-described embodiments. For example, although the throttle device 1 including a single throttle hole 2 mounted on a bicycle with a prime mover was concretized in the above-described embodiments, the use and the form of the throttle device 1 are not limited thereto. The present application can be applied to all so-called straddle-type vehicles in which a rider rides in a straddling manner over a saddle, and as such straddle-type vehicles, not only two-wheeled vehicles (bicycles with a prime mover and the like) equipped with a small displacement engine such as a scooter and a moped, but also two-wheeled vehicles (automatic two-wheeled vehicles and the like) equipped with a larger displacement engine or an ATV (All Terrain Vehicle) and the like. Therefore, the engine mounted on the above-described various vehicles as a traveling power source can be taken as an object, and the throttle device of the present application can be arbitrarily applied. In addition, the throttle device of the present application can be applied to an engine used for a use other than a traveling power source, for example, an engine for a generator and the like. In addition, a multi-throttle device including a plurality of throttle holes can be concretized.

[0121] Further, in the above embodiment, the intake temperature sensor 22 and the intake pressure sensor 23 are arranged using the dead zone formed around the throttle valve opening degree sensor 21 by the provision of the throttle cover 7, but this is not limiting. The position on the throttle cover 7 at which the dead zone is formed differs depending on the structure of each member provided on the throttle cover 7, and a dead zone is formed around the gear train 8 if, for example, the number of gears constituting the gear train 8, the arrangement, etc. are changed. In any case, as long as each sensor 21 to 23 is arranged in concentration on the throttle cover 7 using the dead zone, the effects described in the above embodiment are obtained, and therefore, as for the arrangement position thereof, it can be any position on the throttle cover 7.

[0122] Further, in the above embodiment, the throttle valve opening degree sensor 21 includes the intake temperature sensor 22 and the intake pressure sensor 23, but it is not necessary to include all of the sensors 21 to 23, and for example, any one of the intake temperature sensor 22 and the intake pressure sensor 23 can be omitted depending on the requirements from the engine control, etc.

[0123] Further, in the above embodiment, the intake temperature sensor 22 and the pressure passage 44 inside the throttle hole 2 are arranged in a front-rear relationship corresponding to the front-rear relationship of the intake temperature sensor 22 and the intake pressure sensor 23 on the throttle cover 7, but it is not necessary to be arranged in the above-described front-rear relationship, and the front-rear relationship of the two sensors 22, 23 can be reversed.

[0124] Further, in the above embodiment, the gear train 8 is used in order to transmit the rotation of the motor 9 to the throttle valve shaft 3, but the transmission mechanism of the present application is not limited to this, and any well-known transmission mechanism can be arbitrarily applied.

[0125] Further, in the above embodiment, the connector 34 provided on the outer side surface of the throttle cover 7 is directed forward, but this is not limiting. The throttle device 1 is mounted on various vehicle bodies, the arrangement of the members around the throttle device 1 differs depending on the various vehicle bodies, and the mounting posture of the throttle device 1 itself also differs. Further, in any vehicle body, it is required that the partner side connector be easily connected with the connector or interference with the members around be prevented, etc., and as a result, the direction in which the connector is directed differs depending on each vehicle body.

[0126] For the convenience of explanation, Figures 11-13 The throttle device 1 is shown in the same posture as the embodiment, and in Figure 11 the connector 51 is directed rearward, in Figure 12 the connector 52 is directed downward, and in Figure 13The connector 53 is directed to the right. The mounting posture of the actual throttle device 1 to the vehicle body can be different from the one shown, but in any posture, the connector 53 is directed to the right in the throttle device 1. Figure 11 In the throttle device 1, the direction of the connector 53 is determined in accordance with the point of view that there is a space surplus on the engine side. Figure 12 In the throttle device 1, the direction of the connector 53 is determined in accordance with the point of view that there is a space surplus on the lower portion of the engine. Figure 13 In the throttle device 1, the direction of the connector 53 is determined in accordance with the point of view that there is a space surplus on the side portion of the engine. For example, when the above-mentioned gear cover 7 is selectively combined to the throttle device main body 5 in accordance with the requirement from the vehicle body side, since the throttle device main body 5 can be shared, it contributes to the cost reduction of the throttle device 1.

Claims

1. A throttle device for an engine, characterized by, The throttle device for an engine includes: a throttle device main body formed with a throttle hole that communicates with a cylinder in a state of being mounted to an engine, a throttle valve is supported to be able to open and close in the throttle hole by a throttle valve shaft, and the throttle valve shaft protrudes from an outer side toward one side; a cover member that closes an outer side of the throttle device main body from the one side, and divides a mechanism room in which a transmission mechanism is housed between the cover member and the outer side; a motor that is mounted to the throttle device main body, and rotation of an output shaft that protrudes into the mechanism room is transmitted to the throttle valve shaft via the transmission mechanism, and an amount of intake air that flows through the throttle hole is adjusted according to opening and closing of the throttle valve; a throttle opening degree sensor that is provided to the cover member and detects a rotation angle of the throttle valve shaft as a throttle opening degree; an intake air temperature sensor that is provided to the cover member and detects a temperature of the intake air that flows through the throttle hole; and an intake air pressure sensor that is provided to the cover member and detects a pressure of the intake air that flows through the throttle hole via a pressure passage that is formed by a tube that is integrally formed on an inner side of the cover member and a through hole that is formed in the throttle device main body, the tube is provided so as to extend from the cover member toward the throttle hole and is inserted into the through hole, and a base end communicates with the intake air pressure sensor.

2. The throttle device for an engine according to claim 1, wherein the through hole is opened on a downstream side of the throttle valve in the throttle hole, a front end of the tube reaches halfway of the through hole, the through hole and an inside of the tube are continuous with each other and form the pressure passage.

3. The throttle device for an engine according to claim 2, wherein an O-ring is interposed between the base end of the tube and the throttle device main body.

4. The throttle device for an engine according to any one of claims 1 to 3, wherein the throttle opening degree sensor is disposed on an axis line of the throttle valve shaft in the mechanism room, at least either one of the intake air temperature sensor and the intake air pressure sensor is disposed in a region around the throttle opening degree sensor on the cover member.

5. The throttle device for an engine according to claim 4, wherein at least either one of the intake air temperature sensor and the intake air pressure sensor is disposed in a region on the cover member that is on a side opposite to the transmission mechanism with reference to the throttle opening degree sensor.

6. The throttle device for an engine according to claim 1, wherein the intake air temperature sensor is provided so as to extend from the cover member toward the throttle hole, and a front end protrudes into the throttle hole via the through hole that is formed in the throttle device main body.

7. The throttle device for an engine according to claim 6, wherein the front end of the intake air temperature sensor protrudes into the throttle valve on an upstream side in the throttle hole, The intake air temperature sensor is disposed at a position on the cover member corresponding to an upstream side in the direction of flow of intake air, and the intake air pressure sensor is disposed at a position corresponding to a downstream side in the direction of flow of intake air.

8. The throttle device of the engine according to claim 1, characterized in that, At least either one of the intake air temperature sensor and the intake air pressure sensor and the throttle opening degree sensor are electrically connected via a common substrate provided on the cover member and a common connector provided on one side of the cover member, and respective detection signals are outputted to a control device that controls the operation of the engine via the substrate and the connector.

9. The throttle device of the engine according to claim 1, characterized in that, The throttle device main body is formed with a single throttle hole, and is mounted to a single-cylinder engine that is installed as a traveling power source in a straddle-type vehicle.

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