JP2001248462A - Electric intake amount control device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric intake amount control device for an engine capable of performing waterproof and dustproof for a speed reduction gear device without using a special cover. SOLUTION: In this electric intake amount control device for an engine having a throttle valve 20 driven for opening/closing an intake passage 12 by an electric motor 55 via the speed reduction gear device 63, the electric motor 55 is mounted on an end part of a throttle supporting part 22 formed in a throttle body 11 to rotatably support the throttle valve 20, the speed reduction gear device 63 connecting an output shaft 60 of the electric motor 55 to the throttle valve 20 is stored within the throttle supporting part 22, and waterproof and dustproof for the speed reduction gear device 63 are performed by the throttle supporting part 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle body having an intake passage, in which a throttle valve is rotatably supported for opening and closing the intake passage, and the throttle valve is driven by an electric motor via a reduction gear device. ,
The present invention relates to an improvement in an electric intake air amount control device for an engine.

[0002]

2. Description of the Related Art Such an electric intake air amount control device for an engine is already known, for example, as disclosed in Japanese Utility Model Laid-Open Publication No. 8-193528.

[0003]

In such a conventional electric intake air amount control apparatus, a throttle valve and an electric motor are arranged so that their axes are parallel to each other, and between the two, a throttle valve and an electric motor are disposed between the electric motor and the throttle valve. Since the reduction gear device for driving the reduction gear is provided, the reduction gear device is exposed, and a special cover is required to cover the exposure device in order to achieve waterproof and dustproof. This is not preferable because it causes an increase in the number of parts and an increase in the outer shape.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made to be able to achieve waterproof and dustproof of a reduction gear device without using a special cover. It is an object to provide a control device.

[0005]

In order to achieve the above object, the present invention provides a throttle body having an intake passage rotatably mounted on a throttle body for opening and closing the intake passage. A throttle support having a support hole for rotatably supporting a throttle valve is formed in a throttle body, wherein the throttle support is driven by a reduction gear device. A first feature is that an electric motor is mounted at one end of the motor so as to close the support hole, and a reduction gear device connecting the output shaft of the electric motor and the throttle valve is accommodated in the throttle support.

According to the first feature, the throttle support for supporting the throttle valve is used not only for mounting the electric motor but also as a housing for accommodating the reduction gear device. Therefore, not only can the mounting structure of the electric motor be simplified, but also the waterproofing and dustproofing of the reduction gear device can be achieved without using a special cover.

Further, according to the present invention, a throttle valve is rotatably supported on a throttle body having an intake passage so as to open and close the intake passage, and the throttle valve is driven by an electric motor via a reduction gear device. In an electric intake air amount control device for an engine, a throttle body is provided with a throttle support portion having first and second support holes coaxially arranged in a throttle body, and a rotary type throttle valve is rotatable in the first support hole. The second feature is that the reduction gear device for connecting the output shaft of the electric motor and the throttle valve is accommodated in the throttle support portion. And

According to the second feature, the first and second support holes coaxially arranged for supporting the throttle valve and the electric motor can be simultaneously formed on the throttle support portion with high precision. The property becomes good. In addition, the reduction gear device that connects the output shaft of the electric motor and the throttle valve can be configured with high precision, so that the backlash of the reduction gear device is minimized and the throttle valve is driven by the electric motor. Can be performed accurately. Moreover, since the reduction gear device is housed in the throttle support portion, the reduction gear device can be made waterproof and dustproof without using a special cover.

Further, in addition to the first or second feature, the present invention further provides a reduction gear including a pinion provided on an output shaft of the electric motor, a ring gear provided on a throttle valve surrounding the pinion, and an electric motor. A third feature is that it comprises an idle gear which is rotatably supported by the housing and meshes with the pinion and the ring gear.

According to the third feature, the reduction gear device can be made compact and easily housed in the throttle support.

Further, the present invention, in addition to any one of the first to third features, is characterized in that a cylindrical concave portion is formed at one end of the throttle valve and a reduction gear device is provided in this concave portion. This is the fourth feature.

According to the fourth aspect, by accommodating the reduction gear device in the throttle valve, the size of the throttle support can be reduced, and the overall intake amount control device can be reduced in size.

Still further, according to the present invention, in addition to the fourth feature, a first support hole in which the throttle valve is rotatably fitted to the throttle support portion, and a first support hole having a diameter larger than the first support hole, A second support hole is provided in the support hole via a step, and a positioning flange formed at one end of the throttle valve is rotatably received in the second support hole, and cooperates with the step. The fifth feature is that the housing of the electric motor that restrains the axial movement of the positioning flange is fitted and fixed.

According to the fifth aspect, the axial position of the throttle valve can be determined using the housing of the electric motor. Therefore, the throttle valve can be axially positioned without using a special positioning stopper member, which can contribute to simplification of the configuration.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIG. 1 is a longitudinal sectional side view of an engine provided with the electric intake air amount control device of the present invention, FIG. 2 is a longitudinal sectional side view of the electric intake amount control device, and FIG. FIG. 4 is an enlarged vertical sectional view of the electric motor unit in FIG. 2, FIG. 5 is a sectional view taken along line 5-5 in FIG. 3, and FIG. 6 is an exploded view of the electronic control unit unit in FIG.

Referring to FIGS. 1 and 2, an engine E is a four-stroke engine for a motorcycle, and includes a cylinder block 1 and a cylinder head 2 which take a substantially horizontal posture with their heads directed forward of the vehicle. The cylinder head 2 is provided with an intake port 3, an exhaust port 4, an intake valve 5, an exhaust valve 6, and a valve mechanism 7 for opening and closing these valves. An intake pipe 8 communicating with the intake port 3 is joined to the upper surface of the cylinder head 2. The intake pipe 8 is made of synthetic resin, and an electromagnetic fuel injection valve 9 is attached to a support boss 8c formed on one side thereof by a valve holder 91. The fuel injected from the fuel injection valve 9 is directed to the intake port 3 of the cylinder head 2 by a fuel discharge hole 86 formed in the intake pipe 8.

The valve holder 91 includes a first holding cylinder 91a fitted to the base of the fuel injection valve 9, a second holding cylinder 91b fitted to a tip of the valve 9 having a fuel inlet, and a second holding cylinder 91b. A connecting portion 91c that integrally connects the two holding cylinder portions 91a and 91b.
And a hose joint 92 discharged from one side of the second holding cylinder portion 91b are integrally formed of synthetic resin. The first holding cylinder portion 91a has a metal ring connected to the support boss 8c. 93 are buried. A fuel hose 94 connected to a fuel injection pump (not shown) is connected to the hose joint 92.

An electric intake air amount control device 10 is connected to an upstream end of the intake pipe 8 to which the fuel injection valve 9 is mounted. That is, the intake air amount control device 10 is disposed upstream of the fuel discharge holes 96 in the intake system of the engine E. Intake amount control device 10
Is provided with a throttle body 11 made of synthetic resin.
This throttle body 11 has an intake path 12 inclined with the downstream side slightly downward, the upstream end of which is enlarged in a funnel shape, and an annular concave portion on the inner peripheral surface of the downstream end. 13a are formed.

At the funnel-shaped upstream end of the intake passage 12,
An air cleaner (not shown) is connected via a rubber intake duct 95.

The intake air amount control device 10 will be described in detail with reference to FIGS.

2 and 3, a straight passage 33 of an auxiliary intake passage 34, which will be described later, is provided in the throttle body 11 at the downstream end face thereof in parallel with the intake passage 12. Annular recess 1 on the inner peripheral surface at the downstream end
3b is formed.

On the other hand, the intake pipe 8 includes an intake path 8a for connecting the intake path 12 to the intake port 3 of the engine E, and a straight path 3
3 is provided with an auxiliary intake passage 8b communicating with a supercharging pump 36 driven by the engine E.
A pair of fitting cylinders 26a and 26b are formed at the upstream end of the intake pipe 8 in correspondence with the a and the auxiliary intake passage 8b, and these are fitted in the annular recesses 13a and 13b respectively.
Fitted via 4a, 14b.

The throttle body 11 and the intake pipe 8 include:
Connecting flanges 15 and 16 are formed which are in contact with each other, and are connected to each other by a connecting ring 17 having a U-shaped cross section. Thus, the throttle body 11 is connected to the intake pipe 8. At this time, the fitting tube portion 26a of the intake pipe 8,
Seal members 14a, 14b mounted on each outer periphery of 26b
Is brought into close contact with the inner peripheral surfaces of the annular recesses 13a and 13b of the throttle body 11, and the throttle body 11 and the intake pipe 8 are
Since the airtightness between the insides is maintained, finishing of each end face of both connecting flanges 15 and 16 is not required,
The airtightness between the throttle body 11 and the intake pipe 8 can be ensured, and not only the thickness of the flanges 15 and 16 can be reduced, but also the connecting portions thereof can be made compact.

The throttle body 11 is integrally formed with a cylindrical throttle support 19 having a support hole 18 which is orthogonal to the axis of the intake passage 12 and has a larger diameter than the intake passage 12. Of the throttle valve 20 is rotatably fitted. This throttle valve 20 is also made of synthetic resin.

As shown in FIG. 4, one end of the throttle support 19 has a second support hole 2 having a diameter larger than that of the support hole 18 and coaxially connected to the support hole 18 through an annular step 22.
1 is provided, and an annular step 22 is formed in the second support hole 21.
A positioning flange 20a is formed integrally with the outer periphery of one end of the throttle valve 20.

An end of a housing 56 of an electric motor 55 for opening and closing the throttle valve 20 is fitted into the second support hole 21, and a mounting flange 57 protruding from the outer periphery of the housing 56 has a throttle flange 57. It is fixed to one end surface of the support portion 19 by a bolt 69 (see FIG. 1). Thus, the support hole 18 into which the throttle valve 20 is fitted is closed by the electric motor 55.

The electric motor 55 includes a stator 58 fixed to the inner peripheral surface of the housing 56, a rotor 59 cooperating with the stator 58, and an output shaft 60 fixed to the rotor 59 and penetrating the center thereof. Is provided. Housing 5
6 comprises a cylindrical housing body 56a for supporting the stator 58, and inner and outer end brackets 56b, 56c coupled to both ends of the housing body 56a. Support both ends of the output shaft 60 via bearings 61 and 62. Accordingly, the inner end of the housing body 56a is fitted into the second support hole 21 together with the inner end bracket 56b, and the inner end bracket 56b cooperates with the annular step 22 to rotate the shaft of the positioning flange 20a. The directional movement, that is, the axial movement of the throttle valve 20 is restricted. Of course, a minute gap is provided between the positioning flange 20a and the inner end bracket 56b to allow rotation of the positioning flange 20a.

As shown in FIGS. 4 and 5, the electric motor 5
From 5, a reduction gear device 63 that drives the throttle valve 20 to reduce the speed is provided in the throttle support 19. This reduction gear device 63 is provided with the inner end bracket 56 of the output shaft 60.
b, a pinion 64 formed at the end protruding outside, a ring gear 65 of internal teeth formed at one end of the throttle valve 20 and surrounding the pinion 64, and an inner end bracket 56
and an idle gear 66 meshed with a pinion 64 and a ring gear 65 supported by a support shaft 67 protruding from b. The ring gear 65 is connected to the throttle valve 20.
Cylindrical recess 6 provided to open at one end surface
8 is formed on the inner peripheral surface. In the illustrated example, three support shafts 67 and the idle gear 66 are arranged at equal intervals around the output shaft 60.

Referring again to FIGS. 2 and 3, the throttle valve 20 has a valve hole 27 having the same cross section as the intake passage 12.
When the throttle valve 20 is in the fully closed position, the valve hole 27 is completely disengaged from the intake passage 12 to be in a non-conductive state, and when the throttle valve 20 is fully opened, the valve hole 27 is aligned with the intake passage 12 to form a continuous intake passage 12. It has become.

The throttle valve 20 is formed with a vertical hole 31 opening on one side surface of the valve hole 27 and a horizontal hole 32 penetrating one side wall of the vertical hole 31. A straight passage 33 that opens at the upstream end surface of the body 11 is formed in the throttle body 11. The vertical intake hole 31, the horizontal hole 32 and the straight passage 33 form the auxiliary intake passage 3.
4 are configured. The auxiliary intake path 34 is connected to the supercharge pump 36 via the auxiliary intake path 8b of the intake pipe 8 as described above.

On the upper end surface of the throttle valve 20, a cap 38 made of synthetic resin for closing the opening of the vertical hole 31 is provided.
The cap 38 is integrally formed with a connecting shaft 39 having a cross section of a broken circle extending coaxially with the throttle valve 20. A rotor 40r of a throttle sensor Sth for detecting the opening of the throttle valve 20 is provided on the connecting shaft 39.
Are connected.

The throttle body 11 is connected to the auxiliary intake passage 8
If b is not provided, the connecting shaft 39 can be formed integrally with the throttle valve 20.

The connecting cylinder 41 has a slit 42 at its tip for imparting a reduced diameter elasticity so that it can be fitted to the outer peripheral surface of the connecting shaft 39 without play. Rotor 40
A return spring 37 composed of a torsion coil spring, which urges the throttle valve 20 in the closing direction via a rotor 40r, is connected between the throttle body 11 and the throttle body 11. Therefore, the return spring 37 is connected to the throttle valve 20.
And a return spring common to the rotor 40r.

As shown in FIGS. 2 and 6, a tray-shaped control unit mounting portion 43 is integrally connected to the other end of the throttle support portion 19 opposite to the side on which the electric motor 55 is mounted.
The electronic control unit U is attached to this. The electronic control unit U includes a sensor substrate 44 facing the bottom surface of the control unit mounting portion 43, an element substrate 45 arranged on the back surface of the sensor substrate 44, a unit housing 46 for accommodating the substrates 44, 45, and Consists of

The sensor substrate 44 is provided with a support hole 49 into which the center shaft 48 of the rotor 40r of the throttle sensor Sth is rotatably fitted, and the rotation angle of the rotor 40r, that is, the opening of the throttle valve 20 The brush 50
A stator 40s that converts the electric signal into an electric signal is formed. The sensor substrate 44 has a boost negative pressure sensor Spb
Is attached. This boost negative pressure sensor Spb
Through a detection hole 47 opened in the intake passage 12 downstream of the throttle valve 20, a boost negative pressure of the engine E, in other words, an engine load is detected and converted into an electric signal.

In the throttle sensor Sth,
The brush 50 can be provided on the stator 40s side by exchanging the facing surfaces of the rotor 40r and the stator 40s. Further, a throttle sensor Sth is formed by using a Hall element and a magnet.
Can be configured in a non-contact type.

Further, a male connection terminal 51a is protruded from the lower surface of the sensor board 44, and a female connection terminal 51b connected thereto is provided on the bottom surface of the control unit mounting portion 43. This female connection terminal 51b has a throttle body 1
A conducting wire 52 connected to the intake air temperature sensor St facing the entrance of one intake passage 12 is connected. The intake air temperature sensor St and the conductor 5
The 2 and female connection terminals 51b are embedded in the throttle body 11 during molding. This eliminates the need for wiring work between the intake air temperature sensor St and the electronic control unit U. Note that, since the electronic control unit U is integrally attached to the throttle body 11, even if the intake air temperature sensor St is attached to the electronic control unit U, the temperature of the intake air flowing through the intake passage 12 is indirectly transmitted through the throttle body 11. The detection can be performed, and the wiring connected to the intake air temperature sensor St can be omitted.

On the upper surface of the sensor substrate 44, a stator 40s of the throttle sensor Sth, a boost negative pressure sensor Spb
And a female connection terminal 80b connected to the male connection terminal 51a and the like.
Is buried.

On the element substrate 45, the female connection terminals 80 are provided.
b, and a fuel injection amount control element 81, a fuel injection timing control element 82, an ignition timing control element 83, and other various control elements connected to the male connection terminal 80a. In addition, an LED indicator 84 used for testing the electronic control unit U and for failure alarms
Are attached, and the element substrate 45 is molded and connected to the unit housing 46. In this case,
There is no need to provide the indicator 84 on a special instrument panel or the like, and no wiring is required for that purpose.

A coupler housing 85 is integrally formed on one side of the unit housing 46, and a plurality of coupler terminals 86 (only one of them is shown in the figure) connected to each of the above-described elements is disposed inside the coupler housing 85. And a coupler half 87a is formed by these components. Thus, when the electronic control unit U is integrally provided with the coupler half 87a, the wiring work therebetween is not required, and the number of parts can be reduced.

The coupler half 87a is connected to an external power supply, an accelerator pedal angle sensor Sp, an engine speed sensor Sne, a crank position sensor Sc and other various sensors, and an ignition timing control device Ig and other various control devices. Another coupler half 87b having a connection terminal is connected.

The fuel injection amount control element 81 and the fuel injection timing control element 82 are connected to the two coupler halves 87.
a, 87b may be connected to the solenoid of the electromagnetic fuel injection valve 9 to operate it, but in the case of the illustrated example, the fuel injection amount control element 81 and the fuel injection timing control element 82 The conductors 88 and 89 connecting the output part of the fuel injection valve 9 and the solenoid of the fuel injection valve 9 are embedded in the throttle body 11 and the intake pipe 8. At that time, the throttle body 11
A female connection terminal 90b and a male connection terminal 90a for connecting the conductors 88 and 89 are provided on the joint surface of the intake pipe 8 and a pair of similar connection terminals. It is also provided on the joint surface of the valve 9. By doing so, electrical connection can be made at the same time as assembling of parts, which can contribute to improvement of assemblability and reduction of the number of parts. If the throttle body 11 and the intake pipe 8 are integrally formed of synthetic resin, no connection terminal is required, and the number of parts can be further reduced.

When the electronic control unit U is mounted on the throttle body 11, the sensor board 44 is
Are stacked on the lower surface of the element substrate 45, and the connection terminals 80a, 80
b are connected to each other. And unit housing 4
6 is a control unit mounting portion 43 of the throttle body 11.
When the seal is fitted to the sensor board 44, the connection terminals 51a and 51b of the sensor board 44 and the throttle body 11 are connected to each other, and in this state, the contact surface between the unit housing 46 and the control unit mounting portion 43 is welded. Note that the unit housing 46 and the control unit mounting portion 43 can be connected to each other in a separable manner by clips, screws, or the like, so that maintenance and inspection inside the electronic control unit U can be performed. .

Next, the operation of this embodiment will be described.

During operation of the engine E, when an accelerator pedal (not shown) is depressed, the depression angle is detected by an accelerator pedal angle sensor Sp and inputted to the electronic control unit U, and the electronic control unit U responds accordingly. The motor 55 is energized to rotate the rotor 59. When the rotor 59 rotates, the pinion 64 rotates together with the output shaft 60, and while the throttle valve 20 is driven in the opening direction through the idle gear 66 and the ring gear 65 in a decelerating manner,
The opening of the valve 20 can be finely adjusted. When the throttle valve 20 is opened to an opening corresponding to the angle of the accelerator pedal, the opening is detected by the throttle sensor Sth and sent to the electronic control unit U. Supply.

The throttle support 19 for rotatably supporting the throttle valve 20 is provided with an electric motor 55.
Also, since the reduction gear device 63 is housed, the mounting structure of the electric motor 55 can be simplified, and the reduction gear device can be made waterproof and dustproof without using a special cover. it can.

Also, support holes 18 and 21 coaxially arranged for supporting the throttle valve 20 and the electric motor 55.
Can be simultaneously formed on the throttle support portion 19 with high precision and can be easily manufactured.
The reduction gear device 63 connecting the output shaft 60 and the throttle valve 20 can be configured with high precision.
The backlash of the reduction gear unit 63 can be minimized, and the electric motor 55 can drive the throttle valve 20 accurately.

Further, the reduction gear device 63 includes a pinion 64 formed on the output shaft 60 of the electric motor 55, a ring gear 65 formed on the inner peripheral surface of the cylindrical recess 68 of the throttle valve 20, and End bracket 56
Since it is compactly composed of the idle gear 66 meshed with the pinion 64 and the ring gear 65 supported by the shaft b, it can be easily accommodated in the throttle support 19, particularly in the narrow recess 68 of the throttle valve 20. ,
Therefore, it is possible to reduce the size of the throttle support portion 19 and contribute to downsizing of the entire electric intake air amount control device 10.

Furthermore, the second of the throttle support 19
Of the annular step 22 and the electric motor 55
The inner end bracket 56b of the throttle valve 2
Since the axial movement of the positioning flange 20a formed on one end of the throttle valve 20 is restricted, the axial positioning of the throttle valve 20 can be performed without using a special positioning stopper member, and the configuration is simplified. Can contribute.

When the engine E is started and idling, the throttle valve 20 is set to the fully closed position where the valve hole 27 is completely different from the intake path 12. This throttle valve 20 is of a rotary type, and the fitting state of the throttle body 11 with the support hole 18 is always constant.
Even in the fully closed position, there is no danger of sticking unlike the butterfly type throttle valve. In addition, when the engine E operates, the throttle valve 20 is drawn to the downstream side of the intake passage 12 by the action of the intake negative pressure, and comes into close contact with one side of the support hole 18. Of the throttle valve 20 and a favorable fully closed state of the throttle valve 20 can be obtained.

When the throttle valve 20 is rotated to the fully open position, the valve hole 27 is aligned with the intake path 12 and forms a continuous intake path 12 without any existing in the intake path 12. The intake resistance of the engine E is greatly reduced, and the high output performance of the engine E can be improved.

Further, a fuel discharge hole 96 is disposed downstream of the throttle body 11, through which the fuel injection valve 9 is provided.
Is injected into the intake port 3, so that the fuel supply system does not have intake resistance, which is particularly advantageous when the throttle valve 20 is fully closed, and the fuel passes through the throttle body 11. Since there is nothing, the adhesion of fuel to the pipe wall can be minimized, and the fluctuation of the air-fuel ratio can be prevented.

During this time, the air discharged from the supercharging pump 36 is supplied to the engine E via the auxiliary intake passage 34, thereby increasing the charging efficiency and contributing to further improvement in output. By the way, the auxiliary intake passage 34 is provided with the throttle body 11 and the throttle valve 2 so that the auxiliary intake passage 34 opens into the valve hole 27.
0, the formation of the auxiliary intake passage 34 in the throttle body 11 is small, that is, the straight passage 3
Thus, the throttle body 11 with the auxiliary intake passage 34 can be easily formed.

Also, since both the throttle body 11 and the throttle valve 20 are made of synthetic resin, their rotational fitting surfaces have a relatively low coefficient of friction and a relatively low surface hardness. The rotation surface of the rotation surface 20 can be easily adapted at an early stage, so that the opening and closing of the throttle valve 20 can be performed lightly and the amount of air leaking from the rotation surface can be stabilized at an early stage.

Further, since the throttle valve 20 is of a rotary type, the contact surface between the throttle body 11 and the throttle valve 20 is extremely wide, so that good heat radiation and heat reception can be obtained, and the contact surface between them is wide. Thus, the closeability of the throttle valve 20 at the fully closed position is improved, which can contribute to stabilization of the idling of the engine E.

During the operation of the engine E, the throttle valve 2
Throttle sensor St directly connected to rotor 40r
In h, the opening of the throttle valve 20 can be accurately detected. Then, the fuel injection amount control element 81 and the fuel injection timing control element 8 in the electronic control unit 46 are controlled.
2 and the ignition timing control element 83 are provided with a throttle sensor S
th, boost negative pressure sensor Spb, intake air temperature sensor St,
Engine speed sensor Sn and crank position sensor Sc
And the like, the operating state of the engine at that time is determined, and the fuel injection amount control element 81 and the fuel injection timing control element 82 determine the fuel injection amount and the injection timing of the fuel injection valve 9. Determined, so actuate the valve 9;
The ignition timing control element 83 determines the ignition timing and operates an ignition device (not shown) as described above.

The sensor board 44 having the throttle sensor Sth and the boost negative pressure sensor Spb and the element board 45 having the fuel injection amount control element 81, the fuel injection timing control element 82, and the ignition timing control element 83 are different from each other. Since the electronic control unit U is housed in a single unit housing 46 and is mounted on the control unit mounting portion 43 of the throttle body 11, various sensors S
The th, Spb and various control elements 81 to 83 are unitized and can be compactly installed on the throttle body 11.
1, there is no need to provide an installation space for the electronic control unit, so that space efficiency is improved and the control system can be made more compact, and the intake device can be made more compact, and the throttle sensor Sth In addition to simplifying the wiring between the various control elements 81 to 83, it is also possible to integrate the power cords necessary for the operation of the various control elements 81 to 83 and the wiring of the signal lines from the engine speed sensor Sn. it can. The simplification of the wiring is advantageous in reducing the influence of electromagnetic waves and the like.

Moreover, the rotor 4 is connected to the throttle valve 20.
Since 0r is directly connected to the throttle sensor Sth, the opening of the throttle valve 20 can be accurately detected.

Since the various control elements 81 to 83 are disposed on the wide back surface of the sensor board 44 via the element board 45, the various control elements 81 to 83 are connected to the throttle sensor S.
It can be freely arranged without being interfered by the th and the boost negative pressure sensor Spb, and the layout has a large degree of freedom.

In particular, since the sensor substrate 44 and the element substrate 45 are connected to each other in a stacked state so as to be separable from each other, the sensor substrate 44 and the element substrate 45 are compact, and various sensors mounted on the sensor substrate 44 and the element substrate 45 according to the model are provided. And the electronic control unit U having various characteristics by changing the specifications of the elements.
Can be provided at a low price. In addition, since the electronic control unit U is disposed on the opposite side of the electric motor 55 with the throttle body 11 interposed therebetween, the electronic control unit U is less affected by noise generated when the electric motor 55 operates.

Further, since the throttle body 11 is made of a synthetic resin, the throttle body 11 itself has an insulating property. Therefore, the electronic control unit U can be mounted on the throttle body 11 without any special insulating member, and the mounting structure is simplified. Can be achieved.

The present invention is not limited to the above embodiments, and various design changes can be made without departing from the gist of the present invention.

[0064]

As described above, according to the first feature of the present invention, a throttle valve is rotatably supported on a throttle body having an intake passage so as to open and close the intake passage, and this throttle valve is driven by an electric motor. In an electric intake air amount control device for an engine, which is driven via a reduction gear device, a throttle support portion having a support hole for rotatably supporting a throttle valve is formed in a throttle body. An electric motor is mounted at one end so as to close the support hole, and a reduction gear device connecting the output shaft of the electric motor and the throttle valve is accommodated in the throttle support, so that the throttle support supporting the throttle valve is provided. Is used not only for mounting the electric motor but also as a housing for accommodating the reduction gear device. Will be, not only it is possible to simplify the mounting structure of the electric motor, the waterproof of the reduction gear device without using a special cover, it is possible to achieve dust.

According to a second feature of the present invention, a throttle valve is rotatably supported on a throttle body having an intake passage so as to open and close the intake passage, and the throttle valve is driven by an electric motor via a reduction gear device. In the electric intake air amount control device for the engine,
A throttle support having first and second support holes arranged coaxially is provided in the throttle body, and a rotary type throttle valve is rotatably fitted in the first support hole and is fitted in the second support hole. The housing of the electric motor is fitted and fixed, and the reduction gear device for connecting the output shaft of the electric motor and the throttle valve is housed in the throttle support, so that it is arranged coaxially for supporting the throttle valve and the electric motor. The first and second support holes can be simultaneously formed in the throttle support portion with high precision, and the manufacturability is good. Accordingly, the reduction gear device for connecting the output shaft of the electric motor and the throttle valve is also required. Accurate configuration allows the backlash of the reduction gear unit to be minimized and the electric motor to drive the throttle valve accurately. It can be. Moreover, since the reduction gear device is housed in the throttle support portion, the reduction gear device can be made waterproof and dustproof without using a special cover.

According to a third feature of the present invention, the reduction gear is provided with a pinion provided on the output shaft of the electric motor,
Since a ring gear provided around the pinion and provided on a throttle valve and an idle gear supported by the housing of the electric motor and meshing with the pinion and the ring gear, the reduction gear device is compactly formed and the throttle support portion is formed. Can be easily stored.

Further, according to the third feature of the present invention, while the cylindrical concave portion is formed at one end of the throttle valve, and the reduction gear device is disposed in this concave portion, the reduction gear device is installed in the throttle valve. The throttle support can be accommodated, and the size of the throttle support can be reduced, so that the entire intake amount control device can be reduced in size.

According to a fifth feature of the present invention,
A first support hole in which the throttle valve is rotatably fitted to the throttle support portion; a first support hole having a diameter larger than the first support hole;
The first support hole is provided with a second support hole connected through a step,
The second support hole rotatably accommodates a positioning flange formed at one end of the throttle valve,
Since the housing of the electric motor that restrains the axial movement of the positioning flange in cooperation with the step portion is fitted and fixed, it is possible to determine the axial position of the throttle valve using the housing of the electric motor. Yes, so
The axial positioning of the throttle valve can be performed without using a special positioning stopper member, which can contribute to simplification of the configuration.

[Brief description of the drawings]

FIG. 1 is a vertical side view of an engine provided with an electric intake air amount control device of the present invention.

FIG. 2 is a vertical sectional side view of the electric intake air amount control device.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is an enlarged vertical sectional view of the electric motor unit in FIG. 2;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is an exploded view of the electronic control unit in FIG. 2;

[Explanation of symbols]

 E ···· Engine 10 ··· Electric electric intake air amount control device 11 ··· Throttle body 12 ··· Intake path 20 ··· Throttle valve 20a ··· Positioning flange 18 ··· 1st support hole 19... Throttle support 21... 2nd support hole 22... Step 55... Electric motor 56... Housing 60... Output shaft 63. ... reduction gear device 64 ... pinion 65 ... ring gear 66 ... idle gear 68 ... recess

Claims (5)

[Claims] 1. A throttle body (11) having an intake path (12) rotatably supports a throttle valve (20) for opening and closing the intake path (12), and the throttle valve (20) is connected to an electric motor ( 55) In the electric intake air amount control device for the engine, which is driven through the reduction gear device (63) according to (55), the throttle body (11)
A throttle support (19) having a support hole (18) for rotatably supporting a throttle valve (20) is formed in the throttle support (19), and the support hole (18) is closed at one end of the throttle support (19). And the output shaft (60) of the electric motor (55).
And a reduction gear device (63) connecting the throttle valve (20) and the throttle valve (20) is accommodated in a throttle support portion (19). 2. A throttle body (11) having an intake path (12) rotatably supports a throttle valve (20) for opening and closing the intake path (12), and the throttle valve (20) is connected to an electric motor ( 55) In the electric intake air amount control device for the engine, which is driven through the reduction gear device (63) according to (55), the throttle body (11)
A throttle support (19) having first and second support holes (18, 21) arranged coaxially, and a rotary type throttle valve (20) is rotated in the first support hole (18). And a second support hole (21)
A housing (56) of an electric motor (55) is fitted and fixed to the motor, and a reduction gear device (6) for connecting the output shaft (60) of the electric motor (55) and the throttle valve (20).
An electric intake air amount control device for an engine, characterized in that 3) is accommodated in a throttle support portion (19). 3. The electric intake air amount control device for an engine according to claim 1, wherein the reduction gear device (63) is provided with a pinion (64) provided on an output shaft (60) of the electric motor (55). A ring gear (65) provided on the throttle valve (20) so as to surround the pinion (64);
And an idle gear (66) axially supported by a housing (56) of an electric motor (55) and meshing with a pinion (64) and a ring gear (65). Control device. 4. A throttle valve (20) according to claim 1, wherein a cylindrical recess (68) is formed at one end of the throttle valve (20). 68. An electric motor-operated intake air amount control device for an engine, wherein a reduction gear device (63) is provided in (68). 5. The electric intake air amount control device for an engine according to claim 4, wherein the throttle support portion (19) includes:
A first support hole (18) into which the throttle valve (20) is rotatably fitted, and a diameter larger than the first support hole (18);
The second connecting to the first supporting hole (18) via the step (22).
A support hole (21) is provided. A positioning flange (20a) formed at one end of the throttle valve (20) is rotatably accommodated in the second support hole (21). ) And positioning flange (2)
A motor-operated intake air amount control device for an engine, wherein a housing (56) of an electric motor (55) for restricting the axial movement of Oa) is fitted and fixed.