CN113818967A - Throttle device of engine - Google Patents

Abstract

The invention provides a throttle device of an engine, which can realize a desired reduction ratio, reduce a gear accommodating chamber to realize compactness and improve the installation performance to a vehicle. The throttling device comprises: a throttle device body which supports a throttle valve through a throttle shaft in a throttle hole; a drive gear fixed to an output shaft of a motor mounted at the throttle device main body; and a driven gear fixed to the throttle shaft, wherein the rotation of the drive gear is transmitted to the driven gear via an intermediate transmission mechanism. The intermediate transmission mechanism includes a first intermediate gear supported by the first gear shaft and including a first large diameter portion meshing with the drive gear and a first small diameter portion integrally provided with the first large diameter portion, and a second intermediate gear supported by the second gear shaft and including a second large diameter portion meshing with the first small diameter portion of the first intermediate gear and a second small diameter portion integrally provided with the second large diameter portion and meshing with the driven gear.

Description

Throttle device of engine

Technical Field

The present invention relates to a throttle device for an engine.

Background

For example, in the throttle device disclosed in patent document 1, a throttle valve is pivotally supported by the throttle shaft so as to be openable and closable within a throttle hole formed in a throttle device body. The throttle body is provided with a motor, and an output shaft and a throttle shaft of the motor protrude toward an outer side surface of the throttle body and are closed by a gear cover, thereby defining a gear housing chamber between the outer side surface and the gear cover.

In the gear housing, a drive gear is fixed to an output shaft of the motor, and a driven gear is fixed to the throttle shaft. An intermediate gear formed by integrally molding a small diameter portion and a large diameter portion is rotatably supported by a gear shaft between the drive gear and the driven gear, the large diameter portion of the intermediate gear is engaged with the drive gear, and the small diameter portion is engaged with the driven gear. Therefore, when the motor is operated, the rotation of the output shaft is decelerated between the drive gear and the large diameter portion of the intermediate gear, further decelerated between the small diameter portion of the intermediate gear and the driven gear and transmitted to the throttle shaft, and the amount of intake air flowing through the throttle hole is adjusted in accordance with the opening and closing of the throttle valve.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 4055547

Since such a throttle device is mounted in a vehicle in a state of being mounted on an engine, it is required to be compact in order to prevent interference with auxiliary equipment of the engine and the like. For example, the throttle device for a single cylinder engine described in patent document 1 is mounted on a bicycle with a prime mover or the like having a small vehicle body, and is provided with not only auxiliary equipment of the engine but also a fuel tank, a vehicle body frame, and the like around the throttle device, and therefore, it is required to be particularly compact.

In order to make the throttle device compact, it is effective to reduce the gear housing chamber, but there is a limit in that a certain gear diameter is required to achieve a desired reduction ratio from the drive gear to the driven gear. In addition, the motor may be downsized as a measure for downsizing, but the reduction gear ratio needs to be further increased to compensate for the torque reduction of the motor accompanying downsizing. For example, in the throttle device of patent document 1, it is difficult to further reduce the diameter of the small diameter portions of the drive gear and the intermediate gear, which are originally small in diameter, and therefore, the diameter of the large diameter portion of the intermediate gear and the diameter of the driven gear are mainly increased. As a result of the specification change, the gear housing chamber is greatly enlarged, and there is a problem that the size reduction of the motor, which is difficult to obtain, is offset and the reduction in size is not substantially facilitated.

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an engine throttle device that can reduce a gear housing chamber to be compact in size while achieving a desired reduction ratio, thereby improving mountability to a vehicle.

In order to achieve the above object, a throttle device for an engine according to the present invention includes: a throttle body having a throttle hole communicating with the cylinder in a state of being mounted on the engine, the throttle body supporting the throttle valve in the throttle hole so as to be openable and closable by a throttle shaft; a motor attached to the throttle body; a drive gear fixed to an output shaft of the motor; and a driven gear fixed to the throttle shaft, the rotation of the drive gear being transmitted to the driven gear via an intermediate transmission mechanism, the intermediate transmission mechanism including a first intermediate gear and a second intermediate gear, wherein the first intermediate gear is rotatably supported by a first gear shaft disposed between the drive gear and the driven gear, and is composed of a first large diameter portion engaged with the driving gear and a first small diameter portion having a smaller diameter than the first large diameter portion and provided integrally with the first large diameter portion, a second intermediate gear rotatably supported by a second gear shaft disposed between the driving gear and the driven gear, and is composed of a second large diameter portion which meshes with the first small diameter portion of the first intermediate gear, and a second small diameter portion which is smaller in diameter than the second large diameter portion, is provided integrally with the second large diameter portion, and meshes with the driven gear (claim 1).

Alternatively, the first gear shaft supporting the first intermediate gear and the second gear shaft supporting the second intermediate gear may be arranged on opposite sides with respect to a virtual line connecting the drive gear and the driven gear (claim 2).

Alternatively, the first gear shaft supporting the first intermediate gear and the second gear shaft supporting the second intermediate gear may be arranged on the same side with respect to a virtual line connecting the drive gear and the driven gear (claim 3).

Alternatively, the first intermediate gear and the second intermediate gear may be formed as the same member (claim 4).

Alternatively, the throttle shaft and the output shaft of the motor may be projected on the outer surface of the throttle body and closed by a gear cover, to divide a gear housing chamber housing a driving gear, a driven gear and an intermediate transmission mechanism, an intake air temperature sensor and an intake air pressure sensor are provided at a gear cover, wherein the intake air temperature sensor has a front end projecting into a throttle hole of the throttle device body to detect a temperature of intake air flowing in the throttle hole, the intake air pressure sensor communicates with the throttle hole of the throttle device body via a pressure passage, in order to detect the pressure of the intake air flowing through the throttle hole, at least one of the intake air temperature sensor, the intake air pressure sensor, and the pressure passage is disposed in the gear housing chamber at a position that avoids the drive gear, the driven gear, and the intermediate transmission mechanism when viewed in a direction along the throttle shaft (claim 5).

According to the throttle device for an engine of the present invention, the gear housing chamber can be reduced in size to be compact while achieving a desired reduction ratio, and thus the ease of installation into a vehicle can be improved.

Drawings

Fig. 1 is a perspective view showing a throttle device according to an embodiment.

Fig. 2 is a perspective view of the gear cover removed from the throttle body of the first embodiment to show the gear train in the gear housing chamber.

Fig. 3 is a perspective view of the gear cover removed from the throttle body to show the inner side surface of the gear cover.

Fig. 4 is an exploded perspective view showing a relationship among the motor, the gear train, and the throttle shaft.

Fig. 5 is a side view showing a state in which the motor, the gear train, and the throttle shaft are coupled to each other.

Fig. 6 is a diagram showing the arrangement of the gear train and the sensors in the gear housing chamber.

Fig. 7 is a diagram showing the arrangement of the intake air temperature sensor and the pressure passage in the gear housing chamber.

Fig. 8 is a sectional view taken along line VII-VII in fig. 7, showing the arrangement state of the intake air temperature sensor in the gear housing chamber.

Fig. 9 is a sectional view taken along line VIII-VIII of fig. 7 showing the arrangement state of the intake pressure sensor and the pressure passage in the gear housing chamber.

Fig. 10 is a diagram showing another example in which the arrangement of each sensor of the first embodiment is changed.

Fig. 11 is a diagram showing another example of the first embodiment in which the arrangement of the sensors is changed.

Fig. 12 is a diagram showing another example of the third embodiment in which the arrangement of each sensor is changed in the first embodiment.

Fig. 13 is a diagram showing another example of the fourth embodiment in which the arrangement of each sensor of the first embodiment is changed.

Fig. 14 corresponds to fig. 6 and shows a second embodiment.

Fig. 15 is a diagram showing another example of the fifth embodiment in which the arrangement of each sensor of the second embodiment is changed.

Fig. 16 is a diagram showing another example in which the arrangement of each sensor of the second embodiment is changed.

Fig. 17 corresponds to fig. 5, and shows a third embodiment.

Fig. 18 is a view corresponding to fig. 6, which also shows the third embodiment.

(symbol description)

1 throttling device

2 orifice

3 throttle valve shaft

4 throttle valve

5 throttling device body

6 gear accommodating chamber

7 Gear cover

9 Motor

9a output shaft

14 concave part (outer side)

18 air inlet temperature sensor

19 air inlet pressure sensor

21 pressure path

25 drive gear

26 driven gear

27 intermediate transfer mechanism

28 first intermediate gear

28a first large diameter part

28b first minor diameter portion

29 second intermediate gear

29a second large diameter part

29b second minor diameter portion

30 first gear shaft

31 second gear shaft

Detailed Description

(first embodiment)

Hereinafter, a first embodiment of the present invention will be described as embodied in a throttle device for a single cylinder engine mounted on a bicycle with a prime mover as a power source for traveling.

The throttle device 1 is attached to an engine, not shown, and functions to adjust the amount of intake air supplied into a cylinder of the engine in accordance with a throttle operation by a driver. As shown in fig. 1 to 3, the throttle device 1 is constituted as a whole by: a throttle device main body 5 that supports a throttle valve 4 so as to be openable and closable by a throttle shaft 3 in a single throttle hole 2 communicating with a cylinder of an engine; a gear cover 7 defining a gear housing chamber 6 between the gear cover 7 and the throttle body 5; and a motor 9, wherein the motor 9 transmits the rotation of an output shaft 9a protruding into the gear housing 6 to the throttle shaft 3 via the gear train 8, so as to open and close the throttle valve 4.

The throttle device 1 of the present embodiment is mounted on a vehicle in the posture shown in fig. 1. From this orientation, in the following description, the intake air flow direction along the axis Cb of the orifice 2 is referred to as the front-rear direction, the throttle axis direction along the axis Cth of the throttle shaft 3 orthogonal to the front-rear direction is referred to as the left-right direction, and the gear train direction in which the gear trains 8 orthogonal to both directions are arranged is referred to as the up-down direction. Of course, the installation posture of the throttle device 1 is not limited to this, and may be changed to various postures.

(throttle device body 5)

As shown in fig. 4 and 5, the throttle body 5 is provided with the throttle hole 2 penetrating in the front-rear direction, and a motor accommodating chamber 10 accommodating 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 an intake manifold of an engine by a bolt not shown via a flange 11 formed at a rear end of the throttle orifice 2, and an air cleaner not shown is connected to a front end of the throttle orifice 2. The throttle shaft 3 is disposed through the throttle hole 2 in the throttle device main body 5, and is rotatably supported by a bearing, not shown. In the orifice 2, the throttle valve 4 is fixed to the throttle shaft 3 by a pair of screws 13, and during operation of the engine, the throttle valve 4 is opened and closed in accordance with rotation of the throttle shaft 3 to adjust the amount of intake air flowing through the orifice 2.

(Gear housing 6)

The throttle shaft 3 extends rightward in the throttle body 5, and its end portion protrudes outward from the right side surface of the throttle body 5. A recess 14 that opens rightward is formed on the entire right side surface of the throttle body 5. The end of the throttle shaft 3 is surrounded by the recess 14, and the output shaft 9a of the motor 9 also protrudes into the recess 14. The recess 14 corresponds to an outer surface of the throttle body of the present invention.

A gear cover 7 having a concave shape that opens leftward is disposed in the concave portion 14 of the throttle body 5, and the periphery of the gear cover 7 is overlapped with the periphery of the concave portion 14 via a seal not shown and is fastened by a screw not shown. The concave portion 14 is closed by the gear cover 7, and a gear housing chamber 6 extending in the vertical direction is defined between the gear cover 7 and the concave portion 14.

As shown in fig. 4 to 6, a gear train 8 is provided between the output shaft 9a of the motor 9 and the throttle shaft 3 in the gear housing chamber 6. Since the structure of the gear train 8 is a characteristic part of the present invention, as described in detail later, when the motor 9 operates, the rotation of the output shaft 9a is decelerated by the gear train 8 and transmitted to the throttle shaft 3, and the throttle shaft 3 rotates against the urging force of a return spring, not shown, to open and close the throttle valve 4 as described above.

(Gear cover 7, intake air temperature sensor 18, intake air pressure sensor 19)

As shown in fig. 2 and 3, the gear cover 7 is made by injection molding a synthetic resin material, and a substrate 17, an intake air temperature sensor 18, an intake air pressure sensor 19, and a plurality of terminals, not shown, are partially embedded in the inner surface thereof. In the present embodiment, the members 17 to 19 are embedded by insert molding when the gear cover 7 is manufactured, but the manufacturing method thereof is not limited thereto and may be changed arbitrarily. Although fig. 2 and 3 show the substrate 17 and the sensors 18 and 19 as being separated from the gear cover 7, they are actually embedded in the gear cover 7 during injection molding, and they are shown for ease of understanding.

As shown in fig. 3 and 6 to 8, the pair of terminals 18b of the intake air temperature sensor 18 are connected to the substrate 17 and extend in the left direction, and a sensor main body 18a is supported at the tip end thereof. In the right side view of fig. 6 and 7, that is, in the "direction along the throttle shaft" of the present invention, the intake air temperature sensor 18 is disposed in front of and above the throttle shaft Cth, and a seal pipe 18c extending in the left-right direction is fixed to the upper wall 6a in the gear housing chamber 6 in accordance with the position. The seal pipe 18c has a right end opened to the inner surface of the gear cover 7 and a left end closed and projects forward of the throttle valve 4 in the orifice 2.

In a state where the gear cover 7 is coupled to the throttle body 5, the sensor body 18a and the terminal 18b are inserted into the seal pipe 18 c. The intake air temperature sensor 18 is thus configured, and the temperature of the intake air flowing through the orifice 2 is transmitted to the sensor body 18a located at the distal end in the seal pipe 18 c. For example, as the intake air temperature sensor 18, a thermistor or the like whose resistance changes with a change in temperature may be used, and the change in resistance may be converted into an electric signal relating to the intake air temperature and output.

As shown in fig. 3, 6, 7, and 9, the sensor body 19a of the intake pressure sensor 19 is fixed to the inner surface of the gear cover 7 and projects into the gear housing chamber 6, and its terminal 19b is connected to the substrate 17. The intake air pressure sensor 19 is disposed behind and above the throttle axis Cth as viewed from the right, and a pressure passage 21 is formed in the throttle device main body 5 corresponding to the position. Specifically, as shown in fig. 7, the pressure passage 21 is formed to protrude downward from the upper wall 6a of the gear housing chamber 6 and has a tubular shape extending in the left-right direction. The pressure passage 21 has a right end opening into the gear housing chamber 6 in the vicinity of the intake pressure sensor 19 and a left end opening rearward of the throttle valve 4 in the orifice 2. In a state where the gear cover 7 is coupled to the throttle body 5, a pressure chamber 22 is defined between the sensor body 19a of the intake air pressure sensor 19 and the right end of the pressure passage 21, and the pressure of the intake air flowing through the orifice 2 acts on the sensor body 19a via the pressure chamber 22 and the pressure passage 21.

For example, a semiconductor type pressure sensor, a strain gauge type pressure sensor, or the like can be used as the intake pressure sensor 19. The principle of the above-described pressure sensor is well known, and therefore, the semiconductor pressure sensor does not describe in detail, and applies pressure to a pressure receiving surface of a diaphragm forming a silicon gauge, and converts a resistance change (piezoresistive effect) caused by deflection of the silicon gauge according to the pressure into an electric signal related to intake air pressure, and outputs the electric signal. Further, the strain gauge type pressure sensor applies pressure to the metal diaphragm having the resistive bridge attached to the back surface thereof, converts a voltage change of the resistive bridge corresponding to the deflection of the metal diaphragm into an electric signal related to the intake pressure, and outputs the electric signal.

A terminal housing portion 23 is integrally formed at a lower portion of an outer side surface of the gear cover 7, and one ends of a plurality of terminals, not shown, embedded in the gear cover 7 are arranged in line in the terminal housing portion to constitute a connector 24. Each of the terminals extends inside the gear cover 7, and two of the terminals are connected to the motor 9, and the remaining terminals are connected to an intake air temperature sensor 18 and an intake air pressure sensor 19 via a base plate 17.

Although not shown, in a state where the throttle device 1 is mounted on the vehicle body, a vehicle body side connector is connected to the connector 24, and the throttle device 1 is electrically connected to the ECU mounted on the vehicle body via the vehicle body side connector and the wire harness. During the operation of the engine, electric power is supplied from the ECU to the motor 9 and the sensors 18 and 19 via the wire harness, the vehicle body side connector, the terminal, and the board 17, and detection signals output from the sensors 18 and 19 are input to the ECU along a path opposite to the above path.

It is effective to reduce the gear housing chamber 6 in order to make the throttle device 1 compact, but in the throttle device of patent document 1, a certain gear diameter is required in order to achieve a desired reduction ratio, and therefore it is difficult to reduce the gear housing chamber, and as a result, the demand for compactness cannot be satisfied. Therefore, in the present embodiment, a gear train 8 having a different configuration from the throttle device of patent document 1 is provided, and the details thereof will be described below.

(Gear train 8)

As shown in fig. 4 to 6, the gear train 8 of the throttle apparatus 1 includes a drive gear 25, a driven gear 26, and an intermediate transmission mechanism 27, wherein the drive gear 25 is fixed to the output shaft 9a of the motor 9, the driven gear 26 is fixed to the throttle shaft 3, the intermediate transmission mechanism 27 transmits the rotation of the drive gear 25 to the driven gear 26, and the intermediate transmission mechanism 27 includes a first intermediate gear 28 and a second intermediate gear 29 that mesh with each other, and as a result, the gear train is configured by four gears 25, 26, 28, and 29.

An output shaft 9a of the motor 9 protrudes from a lower portion of the gear housing 6 to fix the drive gear 25, and the throttle shaft 3 protrudes from an upper portion to fix the driven gear 26. Between the drive gear 25 and the driven gear 26, a first gear shaft 30 and a second gear shaft 31 are respectively provided upright on the throttle device main body 5. In detail, as seen from the right in fig. 6, the first gear shaft 30 and the second gear shaft 31 are disposed on opposite sides in the front-rear direction with respect to a virtual line L connecting the output axis Cm of the motor 9 and the throttle axis Cth, the first gear shaft 30 is disposed on the front side of the virtual line L, and the second gear shaft 31 is disposed on the rear side of the virtual line L. The second gear shaft 31 is disposed slightly above the first gear shaft 30 in the vertical direction.

The first intermediate gear 28 is rotatably supported by the first gear shaft 30 as described above, and the second intermediate gear 29 is rotatably supported by the second gear shaft 31. The first intermediate gear 28 and the second intermediate gear 29 are schematically arranged in parallel in the left-right direction and are adjacent to each other in the up-down direction in correspondence to the arrangement of the first gear shaft 30 and the second gear shaft 31, and the space occupied by the two gears 28 and 29 is smaller in the up-down direction than in the front-back direction.

The first intermediate gear 28 integrally forms a right first large diameter portion 28a and a left first small diameter portion 28b, and the first large diameter portion 28a meshes with the drive gear 25. The first small diameter portion 28b is set to be smaller in diameter than the first large diameter portion 28a in terms of the diameter, for example, pitch circle, of the first large diameter portion 28a and the first small diameter portion 28 b. The second intermediate gear 29 integrally forms a right second large diameter portion 29a and a left second small diameter portion 29b, the second large diameter portion 29a meshes with the first small diameter portion 28b of the first intermediate gear 28, and the second small diameter portion 29b meshes with the driven gear 26. The second large diameter portion 29a and the second small diameter portion 29b are set to have a smaller diameter than the second large diameter portion 29a in terms of the diameter of each other.

Therefore, when the motor 9 is operated, the rotation of the output shaft 9a is transmitted from the drive gear 25 to the first large diameter portion 28a of the first intermediate gear 28 and is decelerated, transmitted from the first small diameter portion 28b to the second large diameter portion 29a of the second intermediate gear 29 and is decelerated, and further transmitted from the second small diameter portion 29b to the driven gear 26 and is decelerated. As a result, the rotation of the output shaft 9a is transmitted to the throttle shaft 3 through three stages of deceleration, and the throttle valve 4 is opened and closed.

In the present embodiment, the first intermediate gear 28 and the second intermediate gear 29 are formed as the same member. Therefore, for example, a mold for injection molding can be used in common, and the manufacturing cost can be reduced for the reason that the parts stock management becomes easy. Since the angle range of the butterfly throttle 4 when it is opened and closed between the fully open state and the fully closed state is slightly smaller than 90 °, the driven gear 26 has a sector shape in which teeth are formed only in a region necessary for meshing with the second small diameter portion 29b of the second intermediate gear 29.

Fig. 6 shows a gear arrangement of the throttle device 101 of patent document 1 together with the throttle device 1 of the present embodiment. In short, the action of the first intermediate gear 28 and the second intermediate gear 29 of the present embodiment is realized by the single intermediate gear 102 supported by the gear shaft 103 in patent document 1. Since the structure of the gear train 8 other than the intermediate gear 102 is common to the embodiment, the same reference numerals are given to the same drawings. Therefore, in patent document 1, the rotation of the output shaft 9a is transmitted to the throttle shaft 3 through two stages of deceleration.

In order to directly compare the reduction ratios, the inter-shaft distance a between the output shaft 9a of the motors and the throttle shaft 3 is set to be the same, the diameters of the drive gear 25 and the driven gear 26 are set to be the same, the diameters of the small diameter portions 28b, 29b, 102b are set to be the same for the intermediate gears 28, 29, 102, and only the large diameter portion 102a is set to be larger than the first large diameter portion 28a and the second large diameter portion 29 a. According to the above-described setting of the dimensions, the present embodiment realizes a 1: 30, while patent document 1 has a reduction ratio of only 1: in order to realize the same reduction ratio as that of the present embodiment, the large diameter portion 102a of the intermediate gear 102 or the driven gear 26 needs to be made large in diameter.

However, the gear housing 6 is greatly enlarged by increasing the diameter of the gear as viewed from the right. Further, if the sensors 18 and 19 are provided in the gear cover 7 in the throttle device 101 of patent document 1 as in the present embodiment, the gear having the increased diameter interferes with the intake air pressure sensor 19 protruding from the gear cover 7 side into the gear housing chamber 6, the intake air temperature sensor 18 fixed to the upper wall 6a, and the pressure passage 21 rising from the upper wall 6a, and therefore cannot be realized in reality. As a result, it is found that in the throttle device 101 of patent document 1, it is impossible to avoid enlargement of the gear housing chamber 6 due to increase in the diameter of the gear or enlargement of the motor 9 to compensate for shortage of the reduction ratio, and thus it is impossible to make the throttle device 101 compact. In the following description, the intake air temperature sensor 18, the intake air pressure sensor 19, and the pressure passage 21, which are required to prevent interference with the gear train 8 in the gear housing chamber 6, may be collectively referred to as interference prevention required members.

In the present embodiment, as compared with the above-described patent document 1, the gear housing chamber 6 can be reduced in size as viewed from the right while achieving a high reduction ratio while preventing the gear train 8 in the gear housing chamber 6 from interfering with the interference prevention members 18, 19, 21. The above effects are achieved by the following aspects: the first intermediate gear 28 and the second intermediate gear 29 are made to have a reduction multi-step and an intermediate gear made to have a small diameter instead of the intermediate gear 102 of patent document 1, and the degree of freedom of arrangement of the gear train 8 is improved by increasing the number of gears.

In detail, in the present embodiment described based on fig. 6, by arranging the first intermediate gear 28 and the second intermediate gear 29 side by side in the left-right direction and approaching each other in the up-down direction, the occupied space thereof can be reduced mainly in the up-down direction. As a result, the first intermediate gear 28 and the second intermediate gear 29 are disposed by effectively utilizing the space between the drive gear 25 and the driven gear 26, and the gear train 8 is disposed such that the inter-shaft distance a between the output shaft 9a of the motor 9 and the throttle shaft 3 is reduced by reducing the space occupied in the vertical direction.

Therefore, the gear housing chamber 6 is provided with a margin in the vertical dimension, and the interference prevention members 18, 19, and 21 can be disposed at the upper side of the driven gear 26, that is, at the "position avoiding the driving gear, the driven gear, and the intermediate transmission mechanism" in the present invention. As a result, as shown in fig. 6 and 7, the gears 25, 26, 28, and 29 can be prevented from interfering with the interference prevention members 18, 19, and 21 regardless of the rotation angle of the driven gear 26, and therefore, the rotation transmission by the gear train 8 and the detection of the intake air temperature and the intake air pressure by the sensors 18 and 19 can be realized without any problem.

Further, since a high reduction ratio can be achieved by multi-stage reduction of the speed, even if the torque is reduced due to, for example, downsizing of the motor 9, the throttle valve 4 can be opened and closed to adjust the intake air amount without any problem. Further, since the first intermediate gear 28 and the second intermediate gear 29 are made smaller in diameter and the degree of freedom in arrangement of the gear train 8 is improved, a structure suitable for the gear train 8 in which the gear housing chamber 6 is reduced in size when viewed from the right can be adopted. In the present embodiment, the arrangement of the first intermediate gear 28 and the second intermediate gear 29 as described above reduces the inter-shaft distance a and reduces the gear housing chamber 6 mainly in the vertical direction, which is why the entire throttle device 1 can be made compact together with the downsizing of the motor 9, and the mountability to the vehicle can be improved.

Further, the reduction in the diameters of the first intermediate gear 28 and the second intermediate gear 29 also contributes to the reduction in the weight of the throttle device 1. This is because although the number of gears is increased from the single intermediate gear 102 of patent document 1 to the two intermediate gears 28 and 29, the total weight of the intermediate gears 28 and 29 having a reduced diameter is lighter than the single intermediate gear 102, which is a factor of reducing the weight of the throttle device 1.

(other examples one to four)

On the other hand, the arrangement of the intake air temperature sensor 18 and the intake air pressure sensor 19 is not limited to the present embodiment, and various modifications are possible, and other examples of the first embodiment will be described below as first to fourth examples.

In another example shown in fig. 10, the arrangement of the intake air temperature sensor 18 and the intake air pressure sensor 19 is reversed with respect to fig. 6.

In another example second shown in fig. 11, the intake air temperature sensor 18 is disposed on the rear side and the intake air pressure sensor 19 is disposed on the front side at the vertical position between the first intermediate gear 28 and the driven gear 26 and between the second intermediate gear 29 and the driven gear. The sensors 18 and 19 are disposed in the remaining space created around the first intermediate gear 28 and the second intermediate gear 29 by the reduction in diameter, as in the other examples three and four below.

In another third example shown in fig. 12, the arrangement of the intake air temperature sensor 18 and the intake air pressure sensor 19 is reversed with respect to fig. 11.

In another example of the fourth embodiment shown in fig. 13, the position of the intake air temperature sensor 18 is changed to the front side of the driven gear 26 with respect to fig. 12.

Although not described repeatedly, the same operational effects as those of the first embodiment can be obtained in the other examples one to four.

(second embodiment)

Next, a second embodiment will be explained. The difference from the first embodiment is in the arrangement of the first intermediate gear 28 and the second intermediate gear 29 and the arrangement of the intake air temperature sensor 18 and the intake air pressure sensor 19 attached thereto, and other configurations, such as the basic configuration of the throttle apparatus main body 5, other gear arrangements, and the like are the same as those of the first embodiment, and therefore, redundant description is omitted and the difference is mainly described.

Although the first gear shaft 30 and the second gear shaft 31 are provided between the drive gear 25 and the driven gear 26 in an upright manner, in the present embodiment, as viewed from the right in fig. 14, both the first gear shaft 30 and the second gear shaft 31 are disposed on the front side with respect to a virtual line L connecting the output axis Cm of the motor and the throttle axis Cth. Further, a second gear shaft 31 is disposed at a position directly above the first gear shaft 30 in the vertical direction, and the first intermediate gear 28 and the second intermediate gear 29 are rotatably supported by the respective gear shafts 30, 31. The first intermediate gear 28 and the second intermediate gear 29 are arranged in parallel in the vertical direction on the front side of the imaginary line L in accordance with the arrangement of the gear shafts 30 and 31.

As a result, a surplus space is formed on the rear side of the virtual line L, and the axial distance a between the output axis Cm of the motor 9 and the throttle axis Cth is longer than that in the first embodiment, so that the surplus space is enlarged in the vertical direction. Of course, the formation of the surplus space in which the sensors 18 and 19 are arranged with the intake air temperature sensor 18 on the upper side and the intake air pressure sensor 19 on the lower side is achieved because the first intermediate gear 28 and the second intermediate gear 29 have a smaller diameter and the degree of freedom in the arrangement of the gear train 8 is improved.

The arrangement of the intermediate gears 28 and 29 and the sensors 18 and 19 is not limited to the above. For example, in contrast to the above, the intermediate gears 28 and 29 may be disposed on the rear side with reference to the virtual line L, and the sensors 18 and 19 may be disposed in the remaining space formed on the front side.

Since the operational effects achieved by the above configuration are the same as those of the first embodiment, the detailed description is omitted, and in addition to preventing the gear train in the gear housing chamber 6 from interfering with the interference prevention members 18, 19, 21, the reduction gear ratio can be increased to reduce the size of the motor 9, and the gear housing chamber 6 can be reduced in size as viewed from the right to make the entire throttle device 1 compact and lightweight.

(other examples five and six)

The sensors 18 and 19 may be arranged as in the other examples, i.e., the fifth and sixth, on the premise of the arrangement of the first intermediate gear 28 and the second intermediate gear 29 according to the second embodiment.

In another fifth example shown in fig. 15, the intake air pressure sensor 19 is disposed in the remaining space on the rear side of the virtual line L, and the intake air temperature sensor 18 is disposed on the front side of the driven gear 26.

In another sixth example shown in fig. 16, the arrangement of the intake air temperature sensor 18 and the intake air pressure sensor 19 is reversed with respect to fig. 15.

Of course, the arrangement of the gear train 8 according to the present invention is not limited to the first embodiment and the second embodiment, and may be arbitrarily changed in consideration of various conditions such as the arrangement of the sensors 18 and 19.

(third embodiment)

Next, a third embodiment will be explained. The difference from the first embodiment is that the first intermediate gear 28 and the second intermediate gear 29 are provided as different members, and the gear arrangement in the left-right direction along the throttle axis Cth is changed, and since the other configurations are the same as those of the first embodiment, the overlapping description is omitted and the difference is emphasized.

As shown in fig. 17 and 18, the arrangement of the gears 25, 26, 28, and 29 when viewed from the right is the same as that of the first embodiment, and the second intermediate gear 29 is arranged so as to be inverted left and right. Therefore, the second small diameter portion 29b of the second intermediate gear 29 overlaps the first large diameter portion 28a of the first intermediate gear 28 in the left-right direction, but the first large diameter portion 28a is reduced in diameter compared to the first embodiment, so that interference with each other is prevented and free rotation is possible. As a result, the space occupied by the gear train 8 in the left-right direction is reduced from L1 shown in fig. 5 to L2 shown in fig. 17.

Since the driven gear 26 meshes with the second small diameter portion 29b of the second intermediate gear 29, rotation transmission is realized in the order of the drive gear 25, the first large diameter portion 28a of the first intermediate gear 28, the first small diameter portion 28b, the second large diameter portion 29a of the second intermediate gear 29, the second small diameter portion 29b, and the driven gear 26, as in the first embodiment.

According to the throttle device 1 of the present embodiment configured as described above, in addition to the operational effects described in the first embodiment, since the occupied space of the gear train 8 is reduced from L1 to L2, it is particularly helpful to make the throttle device 1 compact in the left-right direction.

The embodiments have been described above, but the embodiments of the present invention are not limited to the above embodiments. For example, although the above-described embodiment is embodied as the throttle device 1 including the single throttle hole 2 attached to the bicycle with a prime mover, the application and the form of the throttle device 1 are not limited thereto. The present invention is applicable to All so-called saddle-ride type vehicles on which a driver rides so as to straddle a saddle portion, and as such saddle-ride type vehicles, there are not only two-wheeled vehicles (e.g., bicycles with prime movers) equipped with engines with small displacement, such as scooters and mopeds, but also ATVs (All Terrain vehicles) such as two-wheeled vehicles (e.g., motorcycles) or four-wheeled off-the-road vehicles equipped with engines with larger displacement. Therefore, the throttle device of the present invention can be applied to any engine mounted on the above-described various vehicles as a power source for running. The throttle device of the present invention may be applied to an engine used for an application other than a power source for running, for example, an engine for a generator. Further, a multi-throttling device including multiple orifices may also be embodied.

In the above embodiment, the intake air temperature sensor 18 and the intake air pressure sensor 19 are provided in the gear cover 7, but the present invention is not limited thereto. For example, the sensors 18 and 19 may be provided on the throttle device main body 5 side, or another sensor, for example, a throttle opening sensor that detects the opening of the throttle valve, may be added in response to a request from the engine control or the like.

In the above embodiment, the intake air temperature sensor 18, the intake air pressure sensor 19, and the pressure passage 21 are disposed at positions avoiding the gear train 8 when viewed from the right, and are prevented from interfering with the gear train 8. For example, when the entire intake pressure sensor 19 is embedded in the gear cover 7 and is not located in the gear housing chamber 6, or when the pressure passage 21 is embedded in the throttle body 5 and is not located in the gear housing chamber 6, it is not necessary to prevent interference with the embedded members 19 and 21, and therefore, it is not necessary to dispose the intake pressure sensor at a position avoiding the gear train 8 when viewed from the right.

Claims (5)

1. A throttle device for an engine, comprising:

a throttle body having a throttle hole communicating with the cylinder in a state of being mounted on the engine, the throttle hole supporting a throttle valve in an openable and closable manner via a throttle shaft;

a motor attached to the throttle device main body;

a drive gear fixed to an output shaft of the motor; and

a driven gear fixed to the throttle shaft and to which rotation of the drive gear is transmitted via an intermediate transmission mechanism,

it is characterized in that the preparation method is characterized in that,

the intermediate transmission mechanism comprises a first intermediate gear and a second intermediate gear,

the first intermediate gear is rotatably supported by a first gear shaft disposed between the drive gear and the driven gear, and includes a first large diameter portion that meshes with the drive gear and a first small diameter portion that is smaller in diameter than the first large diameter portion and is provided integrally with the first large diameter portion,

the second intermediate gear is rotatably supported by a second gear shaft disposed between the drive gear and the driven gear, and includes a second large diameter portion that meshes with the first small diameter portion of the first intermediate gear, and a second small diameter portion that is smaller in diameter than the second large diameter portion, is provided integrally with the second large diameter portion, and meshes with the driven gear.

2. The throttle device of engine according to claim 1,

the first gear shaft supporting the first intermediate gear and the second gear shaft supporting the second intermediate gear are arranged on opposite sides with respect to a virtual line connecting the drive gear and the driven gear.

3. The throttle device of engine according to claim 1,

the first gear shaft supporting the first intermediate gear and the second gear shaft supporting the second intermediate gear are arranged on the same side with respect to a virtual line connecting the drive gear and the driven gear.

4. The throttle device of engine according to claim 1,

the first intermediate gear and the second intermediate gear are made as the same component.

5. The throttle device of engine according to claim 1,

a gear housing chamber that houses the drive gear, the driven gear, and the intermediate transmission mechanism is defined by a gear cover that is closed by protruding the throttle shaft and the output shaft of the motor on an outer side surface of the throttle device body,

an intake air temperature sensor and an intake air pressure sensor are provided at the gear cover, the intake air temperature sensor having a tip end projecting into a throttle hole of the throttle device main body to detect a temperature of intake air flowing through the throttle hole, the intake air pressure sensor communicating with the throttle hole of the throttle device main body via a pressure passage to detect a pressure of the intake air flowing through the throttle hole,

at least one of the intake air temperature sensor, the intake air pressure sensor, and the pressure passage is disposed in the gear housing chamber at a position that avoids the drive gear, the driven gear, and the intermediate transmission mechanism when viewed in a direction along the throttle shaft.

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