JP2001073828A - Suction device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compact a suction device of an engine by forming a throttle sensor and fuel injection controlling elements in a unit structure and installing on a throttle body compactly. SOLUTION: This suction device of an engine is equipped with the throttle body 11 having a suction duct 12 leading to the suction port of the engine, a throttle valve 20 controlling the suction amount by the engine through the suction duct 12, and a fuel injection valve injecting the fuel to be supplied to the engine. The throttle body 11 is furnished with an electronic control unit U incorporated with a throttle sensor Sth for sensing the degree of opening of the throttle valve 20 and fuel injection controlling elements 81 and 82 for controlling the fuel injection amount of the fuel injection valve, at least on the basis of the output signal from the throttle sensor Sth.

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 connected to an intake port of an engine, a throttle valve for controlling an intake amount of the engine through the intake passage, and a fuel injection for injecting fuel supplied to the engine. The present invention relates to an improvement of an intake system of an engine, comprising a valve.

[0002]

2. Description of the Related Art An intake system for such an engine is disclosed in, for example, Japanese Utility Model Laid-Open No. 3-122268.
Already known.

[0003]

In such a conventional intake device, a throttle sensor for detecting an opening of a throttle valve is provided on a throttle body, and a fuel injection control element for controlling a fuel injection amount of a fuel injection valve is provided with: Since each of the electronic control units is installed in a different part from the throttle body, the space for installing the throttle sensor and the electronic control unit must be individually secured, resulting in poor space efficiency, and an intake device. It is difficult to reduce the size of the device, and wiring work between the throttle sensor and the electronic control unit is required.

[0004] It is an object of the present invention to provide an intake device for the engine, which can solve such a problem at once.

[0005]

In order to achieve the above object, the present invention provides a throttle body having an intake passage connected to an intake port of an engine, a throttle valve for controlling an intake amount of the engine through the intake passage, In an intake system for an engine, comprising a fuel injection valve for injecting fuel to be supplied to an engine, a throttle sensor for detecting an opening degree of the throttle valve, and at least an output signal of the throttle sensor based on an output signal of the throttle sensor. A first feature is that an electronic control unit incorporating a fuel injection control element for controlling a fuel injection amount is attached to the throttle body. The fuel injection control elements correspond to a fuel injection amount control element 81 and a fuel injection timing control element 82 in an embodiment of the present invention described later.

According to the first feature, the throttle sensor and the fuel injection control element are unitized and can be mounted compactly on the throttle body. Therefore, in addition to the throttle body, installation for an electronic control unit is possible. There is no need to prepare a space, so that space efficiency is improved and the intake device can be made more compact. Also, the wiring between the throttle sensor and the fuel injection control element can be simplified.

Further, in addition to the above-mentioned features, the present invention provides a rotator which rotates the throttle sensor in conjunction with the opening of the throttle valve, and electrically controls a rotation angle of the rotator facing the rotator. And a stator for converting the signals into signals. The stator is provided on the sensor board of the electronic control unit, and the fuel injection control element is provided on the back side of the sensor board opposite to the throttle sensor. Second
The feature of.

According to the second feature, it is possible to freely dispose the fuel injection control element on the wide back side of the sensor substrate, and the layout can be performed as desired.

Further, the present invention has a third feature in that the throttle body is made of synthetic resin in addition to the first or second feature.

According to the third aspect, the throttle body itself is provided with insulating properties, so that the electronic control unit can be mounted on the throttle body without any special insulating member, thereby simplifying the mounting structure. Can be planned.

According to a fourth aspect of the present invention, in addition to any one of the first to third features, an ignition timing control element for controlling an ignition timing of an engine is incorporated in the electronic control unit. Features.

According to the fourth feature, not only the throttle sensor and the fuel injection control element but also the ignition control element are unitized and can be mounted compactly on the throttle body, thereby simplifying the engine control system. Can be planned.

[0013]

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.

1 to 9 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional side view of an engine provided with an intake air amount control device of the present invention, and FIG. Side view,
3 is a sectional view taken along line 3-3 in FIG. 2, FIG. 4 is an exploded view corresponding to FIG. 3, FIG. 5 is a sectional view taken along line 5-5 in FIG. 3, and FIG.
6, FIG. 7 is a sectional view taken along the line 7-7 in FIG. 3, FIG. 8 is an explanatory view of the operation of the throttle valve, and FIG. 9 is a characteristic chart of the intake air amount control device of the present invention. FIG. 10 is a sectional view showing a second embodiment of the present invention, corresponding to FIG. 8, and FIG.
FIG. 9 is a sectional view illustrating an embodiment and corresponding to FIG. 8.

First, a description will be given of the first embodiment of the present invention. In FIG. 1, 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 facing the front of the vehicle. 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 are provided. 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 the tip of the valve 9 having a fuel inlet, 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 intake amount control device 10 is connected to an upstream end of the intake pipe 8 on 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.

The intake air amount control device 10 will be described with reference to FIGS. The intake air amount control device 10 includes a throttle body 11 made of synthetic resin (for example, made of PPS). 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. In this case, if the intake duct 95 and the case body of the air cleaner are also made of synthetic resin and are integrally formed with the throttle body 11, the configuration can be simplified. At that time, the throttle body 11
Can be arranged in the air cleaner to make the configuration compact.

The throttle body 11 is provided with a straight passage 33 for the auxiliary intake passage 12, which will be described later, which is open at the downstream end surface thereof, in parallel with the intake passage 12.
An annular concave portion 13b is also formed on the inner peripheral surface of the downstream end portion.

On the other hand, the intake pipe 8 includes an intake path 8a for communicating the intake path 12 with 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.

As shown in FIGS. 2 to 4, a fitting hole 18 having a diameter larger than that of the intake passage 12 is provided in the throttle body 11 so as to be orthogonal to the axis X of the intake passage 12. , A rotary type throttle valve 20 is rotatably fitted. This throttle valve 20 is also made of synthetic resin (for example, made of 6/6 nylon). A flange 21 is formed at one end of the throttle valve 20, and the flange 21 is sandwiched between a step portion 22 of the throttle body 11 and a stop ring 23 locked to the throttle body 11, whereby the shaft of the throttle valve 20 is rotated. The direction position is defined.

An annular groove 24 is formed in the throttle body 11 adjacent to the flange 21, and a seal member 25 in close contact with the outer peripheral surface of the throttle valve 20 is mounted in the annular groove 24.

The throttle valve 20 is formed with a valve hole 27 having the same cross section as that of the intake passage 12. The valve hole 27 is located at the fully closed position of the throttle valve 20 (FIG. 7).
7 (A)), the airway 12 is completely inconsistent with the intake path 12 and is in a non-conductive state. At the fully open position (see FIG. 7 (C)), the intake path 12
And a continuous intake path 12 is formed.

At one end of the throttle valve 20, a drive drum 39 having a wire groove 38 on its outer periphery is integrally formed. One end of the operation wire 30 engaging with the wire groove 38 is connected to the drive drum 39. The end is connected to a throttle grip of a steering handle (not shown). When the operation wire 30 is pulled by rotating the throttle grip, the throttle valve 20 can be rotated from the fully closed position to the fully open position.

The throttle valve 20 is formed with a vertical hole 31 extending from the other end face to the valve hole 27 and a horizontal hole 32 penetrating one side wall of the vertical hole 31. A straight passage 33 is formed in the throttle body 11 and opens at the upstream end face of the throttle body 11. These vertical holes 31, horizontal holes 32 and straight passages 33 constitute an auxiliary intake passage 34. 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 other 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.

As shown in FIGS. 3 and 6, the connecting cylinder 41 has a slit 42 formed at the end thereof for imparting diameter-reducing elasticity so that the connecting cylinder 41 can be fitted without looseness on the outer peripheral surface of the connecting shaft 39. It has become. Rotor 40r and throttle body 1
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 return spring 37 and the rotor 1. Therefore, the return spring 37 is a common return spring for the throttle valve 20 and the rotor 40r.

The throttle body 11 is integrally formed with a tray-shaped control unit mounting portion 43, on which an electronic control unit U is mounted. Electronic control unit U
Is composed of 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, and a unit housing 46 for accommodating the substrates 44, 45. .

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.

Incidentally, 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 protrudes 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. 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 board 44, a stator 40s of the throttle sensor Sth and 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 includes an external power supply, an engine speed sensor Sne, a crank position sensor Sc and other various sensors, and an ignition timing control device Ig.
Another coupler half 87b having a connection terminal connected to other various control devices 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. .

3 and 7, the throttle body 11 is provided with a bypass passage 53 bypassing the throttle valve 20 and connecting both ends to the intake passage 12, and a piston type valve element 54 faces the bypass passage 53. The first idle device 55 is attached to the throttle body 11.

The throttle body 11 has a valve guide hole 56 into which the valve body 54 is slidably fitted, an inlet chamber 57 opened at an end face of the valve guide hole 56, and one side surface of the valve guide hole 56. An outlet chamber 58 is provided which communicates with a plurality of small holes 59 extending in the sliding direction of the valve element 54. Bypass 53
Is a bypass passage upstream section 5 connected to the upstream side of the intake passage 12.
3a and a bypass downstream portion 53b connected to the downstream side of the intake passage 12. The downstream end of the bypass upstream portion 53a is connected to the inlet chamber 57, and the upstream end of the bypass downstream portion 53b is connected to the upstream end. It is connected to the outlet chamber 58.

When the valve element 54 moves through the valve guide hole 56, the opening of the group of small holes 59 is adjusted by the side surface of the valve element 54, and the opening of the group of small holes 59 flows through the bypass passage 53. The intake amount is determined.

The first idle device 55 comprises the valve element 54 and temperature-sensitive operating means 60 for operating the valve element 54 in accordance with a change in the temperature of the engine E. The temperature-sensitive operating means 60 includes a housing 62 fitted and fixed in a mounting hole 61 of the throttle body 11, a bottomed cylindrical wax holder 63 fitted in the housing 62, and a wax holder 63. And is slidably fitted to a wax case 65 having a wax 64 sealed therein and a bearing 66 at one end of the wax case 65.
An output rod 68 having one end facing the wax 64 via the seal piston 67 and the other end protruding out of the wax case 65, and sliding on the outer periphery of the wax case 65 while the inner end surface of the output rod 68 is in contact with the tip of the output rod 68. It comprises a bottomed cylindrical operating member 69 movably fitted, a return spring 70 for urging the operating member 69 toward the output rod 68, and an electric heater 71 attached to the wax holder 63. The electric heater 71 is energized after the start of the engine E, and responds to the rise in the engine temperature.
4 is heated.

The operating member 69 has an output rod 68 on its outer end surface.
The shaft 74 is integrally provided with a connecting shaft 74 arranged coaxially with the connecting shaft 74. The connecting shaft 74 is slidably fitted in a connecting hole 75 with a bottom formed in the end face of the valve body 54 on the side opposite to the inlet chamber 57. You.
An outward flange 74a is formed at the end of the connection shaft 74, and an inward flange 75a is formed at the open end of the connection hole 75. The abutment of the two flanges 74a, 75a causes the extension of the connection shaft 74 and the valve element 54. A directional sliding limit is defined. Between the connecting shaft 74 and the valve element 54, a lost motion spring 76 for urging them in the direction of extension and, in the case of the valve element 54, in the closing direction thereof is contracted.

When the wax 64 in the wax case 65 is in a contracted state in a cold state, the operating member 69 is retracted by pushing the output rod 68 into the wax case 65 with the load of the return spring 70. When the wax 64 expands due to heating by the heater 71, the output rod 68 operates so as to advance the operating member 69 toward the valve body 54 against the load of the return spring 70. Therefore, the valve element 54 increases the opening of the small holes 59 when the wax 64 contracts, and decreases the opening of the small holes 59 according to the expansion of the wax 64.

The throttle body 11 is provided with a movable stopper 77 capable of adjusting the closing position of the valve body 54. The movable stopper means 77 is provided in the entrance chamber 5.
7, a stopper bolt 78 screwed to the throttle body 11 so as to face the end face of the valve body 54, and a stopper bolt 78 sandwiched between the head of the stopper bolt 78 and the throttle body 11. A coil spring 79 for preventing delusion.

Next, the operation of this embodiment will be described.

When the engine E is started and idling, the throttle valve 20 is set to a fully closed position where the valve hole 27 is completely different from the intake passage 12, as shown in FIG. The throttle valve 20 is of a rotary type, and the fitting state of the throttle body 11 with the fitting hole 18 is always constant. Therefore, even in the fully closed position, there is no danger of sticking unlike the conventional butterfly type throttle valve. In addition, when the engine E is operating, 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 fitting hole 18. Of the throttle valve 20 and a good fully closed state of the throttle valve 20 can be obtained.

On the other hand, in the cold state, in the first idle adjusting device 55, the wax 64 is contracted, so that the operating member 69 occupies the retracted position under the load of the return spring 70. In this state, the connecting shaft 74 of the operating member 69 and the valve body 5
4 is in a connected state in which the outward flange 74a and the inward flange 75a are brought into contact with each other due to the load of the lost motion spring 76.
As a result, the small holes 59 are held at the high opening position where the small holes 59 are greatly opened.

Therefore, when the engine E is started with the throttle valve 8 fully closed, air is sucked into the engine E through the bypass passage 53, and the amount of intake air is controlled by the small holes 59 in a relatively large amount. The air and the fuel injected from the fuel injection valve 9 are mixed to form a relatively large amount of rich mixture suitable for starting, and the engine E can be started reliably. Even in the warm-up operation state of the engine, a relatively large amount of the air-fuel mixture is supplied to the engine E in the same manner as described above, so that the engine E can obtain the first idling rotational speed and promote the warm-up.

As the warm-up operation proceeds and the engine temperature rises, the heater 71 heats the wax 64 accordingly, so that the wax 64 expands and the operating member 69 resists the load of the return spring 70. To move forward. Accordingly, the valve element 54 is pushed in the closing direction, and the opening degree of the small holes 59 is reduced, so that the amount of intake air passing through the bypass passage 53 decreases. Is also reduced accordingly, so the first idling rotational speed decreases.

When the valve element 54 reaches the position where the valve element 54 comes into contact with the stopper bolt 78, that is, the closed position, the opening degree of the small holes 59 is minimized, and the intake air amount is also minimized. The normal idling speed of the engine E is secured by the minimum intake air amount. Therefore, the stopper bolt 78 is connected to the valve body 54.
, The minimum intake air amount can be adjusted by changing the closing position of the valve body 54, whereby the idling speed can be adjusted to a desired value. Moreover, since the adjustment of the minimum intake air amount is performed by adjusting the opening degree of the small holes 59 provided in the bypass passage 53 having a diameter much smaller than that of the intake passage 12, fine adjustment of the minimum intake air amount requires special skill. And can be easily performed. As described above, when the rotary throttle valve 20 is held in a good fully closed state, the adjustment amount of the first idle device 55 and the stopper bolt 78 is eliminated or significantly reduced, and the stable fast start of the engine E is reduced. Idling and normal idling conditions can be obtained.

Thereafter, when the wax 64 further expands and the operating member 69 further advances, the connecting shaft 74 compresses the lost motion spring 76 and deeply enters the connecting hole 75 of the valve body 54. As long as the valve body 54 is kept at the predetermined closed position, the excessive expansion of the wax 64 is absorbed by the lost motion spring 76, so that the generation of excessive stress can be avoided.

If the valve element 54 is operated by a linear solenoid instead of the wax 64, the idle control can be performed more finely.

When the operation wire 30 is pulled to rotate the throttle valve 20 in the valve opening direction in order to increase the output of the engine E, a valve hole 27 of the throttle valve 20 appears on the intake passage 12 and opens. Since the degree is increased, the intake amount of the engine E can be increased. At this time, as described above, the opening direction of the throttle valve 20 is such that the lower portion of the valve 20 is directed toward the downstream side of the intake passage 12, and as shown in FIG. At the intermediate opening of 20, the lower part of the fitting hole 18 of the throttle body 11 is exposed to the intake passage 12, and even if the fuel tries to accumulate in the lower part of the fitting hole 18 due to the return of the intake air,
Since the air that has flowed in from the inlet of the intake passage 12 descends obliquely through the valve hole 27 and flows along with the fuel along the bottom surface of the fitting hole 18, it is necessary to prevent the fuel from accumulating in the lower portion of the fitting hole 18. Therefore, the influence of the air-fuel ratio on the air-fuel ratio fluctuation can be avoided. Also, at this time, the bottom surface of the valve hole 27 of the throttle valve 20 reliably prevents the fuel from being transferred to the downstream side in an uphill attitude toward the downstream of the intake passage 12.

As shown in FIG. 8 (C), when the throttle valve 20 is rotated to the fully open position, the valve hole 27 is aligned with the intake passage 12, and the intake passage 12 is continuously provided without any air. Since the path 12 is formed, the intake resistance of the intake path 12 can be significantly 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 a fuel injection valve 9 is provided.
Is injected into the intake port 3, so that the fuel supply system does not become 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.

Next, when the traction force on the operation wire 30 is released in order to reduce the output of the engine E, the throttle valve 20 returns to the fully closed position with the repulsive force of the return spring 37, and the engine E is again in the idle state.

Further, 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.

Moreover, 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, and 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.

FIG. 9 is a characteristic diagram showing the relationship between the throttle valve opening and the intake air amount in the intake air amount control device 10 of the present invention.
It shows that the characteristics can be changed by variously selecting the conical shape, inverted conical shape, etc.

During the operation of the engine E, the throttle sensor Sth in which the rotor 40r is directly connected to the throttle valve 20 can accurately detect the opening of the throttle valve 20. And the electronic control unit 4
6, a fuel injection amount control element 81, a fuel injection timing control element 82, and an ignition timing control element 83 are a throttle sensor Sth, a boost negative pressure sensor Spb, an intake air temperature sensor St, an engine speed sensor Sne, and a crank position sensor. Receiving the electric signal output by Sc or 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
Is determined, and the valve 9 is operated as described above, and the ignition timing control element 83 determines the ignition timing, and thus operates the ignition device (not shown).

By the way, the sensor substrate 44 having the throttle sensor Sth and the boost negative pressure sensor Spb, and the element substrate 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, 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 Sne can be integrated. it can. The simplification of the wiring is advantageous in reducing the influence of electromagnetic waves and the like.

Further, 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 laminated 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 depending on the model. And the electronic control unit U having various characteristics by changing the specifications of the elements.
Can be provided at a low price.

Further, since the throttle body 11 is made of a synthetic resin, it has insulating properties itself, and therefore, the electronic control unit U can be mounted on the throttle body 11 without any special insulating member interposed therebetween. Can be achieved.

A second embodiment of the present invention shown in FIG. 10 is different from the first embodiment in that the valve hole 27 of the rotary type throttle valve 20 is formed in a notch shape in which one side is opened upward when fully opened.
The configuration is the same as that of the previous embodiment. In the figure, parts corresponding to those of the previous embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the third embodiment of the present invention shown in FIG. 11, the rotary type throttle valve 20 is arranged so that the lower surface thereof coincides with the bottom surface of the intake passage 12 of the throttle body 11, and the valve hole 27 is formed in one of the positions. The configuration is the same as that of the previous embodiment except that the side is formed in a notch shape that opens downward when fully opened. In the drawing, the same reference numerals are given to portions corresponding to the previous embodiment, and the same reference numerals are used. Description is omitted. According to the third embodiment, no recess is formed in the bottom surface of the intake passage 12 by the fitting hole 18 into which the throttle valve 20 fits, so that accumulation of fuel can be prevented.

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.

[0073]

As described above, according to the first aspect of the present invention, a throttle body having an intake passage connected to an intake port of an engine, a throttle valve for controlling an intake amount of the engine by the intake passage, and an engine And a fuel injection valve for injecting fuel to be supplied to the engine, a throttle sensor for detecting an opening of the throttle valve, and a fuel for the fuel injection valve based on at least an output signal of the throttle sensor. Since the electronic control unit incorporating the fuel injection control element for controlling the injection amount is mounted on the throttle body, the throttle sensor and the fuel injection control element can be unitized and compactly mounted on the throttle body. It is necessary to provide an installation space for the electronic control unit in addition to the body No longer greatly contributes to compactness of the intake system and, moreover, it is possible to simplify the wiring between the throttle position sensor and the fuel injection control device.

According to a second feature of the present invention, the throttle sensor is provided with a rotor which rotates in conjunction with the opening of the throttle valve, and a rotation angle of the rotor which faces the rotor. And a stator for converting to an electric signal, and the stator is provided on the sensor board of the electronic control unit, and the fuel injection control element is provided on the back side of the sensor board opposite to the throttle sensor. The fuel injection control element can be freely arranged on the wide back side of the sensor substrate, and the layout can be easily performed.

Further, according to the third feature of the present invention, since the throttle body is made of synthetic resin, the electronic control unit can be mounted on the throttle body without any special insulating member interposed therebetween, and the mounting structure can be improved. Simplification can be achieved.

According to a fourth feature of the present invention,
Since the electronic control unit also incorporates an ignition timing control element for controlling the ignition timing of the engine, not only the throttle sensor and the fuel injection control element but also the ignition control element are unitized to make the throttle body compact. It can be attached, and the engine control system can be simplified.

[Brief description of the drawings]

FIG. 1 is a vertical side view of an engine including an intake air amount control device according to a first embodiment of the present invention.

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

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

FIG. 4 is an exploded view corresponding to FIG. 3;

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

FIG. 6 is a sectional view taken along line 6-6 of FIG. 3;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 3;

FIG. 8 is a diagram illustrating the operation of a throttle valve.

FIG. 9 is a characteristic diagram of the intake air amount control device of the present invention.

FIG. 10 is a sectional view corresponding to FIG. 8, showing a second embodiment of the present invention;

FIG. 11 is a sectional view showing a third embodiment of the present invention and corresponding to FIG. 8;

[Explanation of symbols]

E ··· Engine X ··· Axis line of intake passage 3 ··· Intake port 9 ··· Fuel injector 11 ··· Throttle body 12 ··· Intake passage 40r ··· Rotor of throttle sensor ·········································································································································································································································································· ..Elements for controlling ignition timing

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F02M 69/00 G01B 21/22 G01B 21/22 F02M 69/00 350J 350L (72) Inventor Akihiro Iimuro Central, Wako, Saitama 1-4-1 F-term in Honda R & D Co., Ltd. F-term (reference) 2F069 AA83 BB40 GG06 HH07 HH15 3G065 AA04 AA11 BA01 CA23 GA01 GA10 HA21 3G066 AA01 AB02 DA01 DA04 DC09 DC19 3G301 HA01 LB02 MA14 MA18 PA07Z PA03Z

Claims (4)

[Claims] 1. A throttle body (11) having an intake path (12) connected to an intake port (3) of an engine (E).
And a fuel injection valve (9) for injecting fuel to be supplied to the engine (E), and a throttle valve (20) for controlling an intake amount of the engine in the intake path (12). , The throttle valve (20)
A throttle sensor (Sth) for detecting an opening of the fuel injection control element (81, 82) for controlling a fuel injection amount of the fuel injection valve (9) based on at least an output signal of the throttle sensor (Sth). An electronic control unit (U) incorporating the above is mounted on the throttle body (11). 2. An intake system for an engine according to claim 1, wherein said throttle sensor (Sth) is rotated in conjunction with an opening of said throttle valve (20); 40r) and a stator (40s) for converting the rotation angle of the rotor (40r) into an electric signal in opposition to the stator (40r).
s) is provided on the sensor board (44) of the electronic control unit (U), and the fuel injection control element (8) is provided on the back side of the sensor board (44) opposite to the throttle sensor (Sth).
(82) An intake device for an engine. 3. An intake system for an engine according to claim 1, wherein said throttle body (11) is made of synthetic resin. 4. The intake system for an engine according to claim 1, wherein the electronic control unit (U) includes:
An intake system for an engine, further comprising an ignition timing control element (83) for controlling the ignition timing of the engine (E).