JP2006112318A - Sliding throttle valve type throttle body in fuel injector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the whole height of a throttle body provided with a sliding throttle valve, while preventing blow-back fuel in an intake passage from intruding into a fuel delivery hole and an annular clearance opening in the intake passage. <P>SOLUTION: The intake passage 11 is opened and closed by the sliding throttle valve 13, and a sliding throttle valve guiding cylinder 12 for storing the sliding throttle valve 13 is continuously arranged upward from the intake passage 11. A fuel injection valve J is arranged on the engine E side of the sliding throttle valve guiding cylinder 12 above the intake passage 11, and is arranged in the same direction as the moving direction X-X of the sliding throttle valve 13. A tip part Ja of the fuel injection valve is inserted and arranged in the fuel delivery hole 1 of the throttle body 10, and a rear end part Jc is inserted into an injection valve inserting hole 2a of a fuel supply pipe 2, and the fuel injection valve J is sandwiched by the throttle body 10 and the fuel supply pipe 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, fuel stored in a fuel tank is boosted by a fuel pump, and the boosted fuel is passed through a fuel injection valve attached to a throttle body into an intake passage downstream of the throttle valve. In particular, a fuel injection device in which an intake passage that penetrates through the throttle body is opened and closed by a sliding throttle valve that moves linearly across the intake passage. Dynamic throttle valve type throttle body.

A conventional sliding throttle type throttle body is shown in FIG.
Reference numeral 10 denotes a throttle body having an intake passage 11 penetrating laterally through the inside, and a sliding throttle valve guide tube 12 is opened continuously from the middle portion of the intake passage 11 upward.
The upper part of the sliding throttle valve guide cylinder 12 opens upward with an upper opening 12a.
Reference numeral 13 denotes a sliding throttle valve that is movably disposed in the sliding throttle valve guide cylinder 12. The sliding throttle valve 13 controls the opening and closing of the intake passage 11 across the intake passage 11 in a straight line direction. .
The sliding throttle valve 13 is opened / closed by a link arm 14, and the upper end of the link arm 14 is screwed and fixed to an operating shaft 15 rotatably supported by the throttle body 10 with a screw. A rotor 14 a disposed at the lower end of the sliding engagement is disposed in an inclined groove 13 a formed above the sliding throttle valve 13.
3 is a state in which the link arm 14 is rotated most counterclockwise, and the sliding throttle valve 13 is in a state in which the intake passage 11 is most closed by the rotor 14a of the link arm 14.
Here, when the operating shaft 15 is operated by the driver and the link arm 14 including the operating shaft 15 rotates clockwise in FIG. 3, the rotor 14a rotates clockwise in the inclined groove 13a. The valve 13 moves upward in FIG. 3 to open the intake passage 11 according to the rotation of the link arm 14.
As described above, the intake passage 11 is controlled to open and close in the linear direction by the sliding throttle valve 13, and the intake passage 11b on the downstream side of the sliding throttle valve 13 is communicated to the engine via an intake pipe (not shown). .
Therefore, the amount of the clean air from which foreign matter has been removed by the air cleaner is controlled by the opening of the sliding throttle valve 13, and flows into the intake passage 11b on the downstream side from the intake passage 11a on the upstream side. Is supplied to the engine via the intake pipe.

In the throttle body 10 having such a sliding throttle valve 13 (in other words, a sliding throttle valve type throttle body), the fuel injection valve J is below the throttle body 10 facing the end 13b of the sliding throttle valve 13, that is, It is disposed below the intake passage 11.
An electromagnetic fuel injection valve J is disclosed in Japanese Patent No. 3049576.
The fuel injection valve J has a cylindrical front end portion Ja on its front end side, and has an injection hole Jb opened on its front end surface Ja1, a rear end portion Jc having a cylindrical shape on its rear end side, and directed toward the rear end surface. Thus, the fuel inflow hole Jd is opened.
The fuel injection valve J has an electromagnetic coil, a movable core, and a valve that moves in synchronism with the movable core. The fuel flowing into the fuel injection valve J from the fuel inflow hole Jd is supplied to the electromagnetic coil. The amount is controlled by opening the valve in accordance with the energization time, and the controlled fuel is discharged from the nozzle hole Jb of the front end face Ja1.
The fuel injection valve J is attached to the throttle body 10 by the following.
First, the throttle body 10 is provided with a fuel discharge hole 16 for inserting and supporting the front end portion Ja of the fuel injection valve J. The upper end thereof is opened below the intake passage 11b on the downstream side of the sliding throttle valve 13, and the lower end of the fuel discharge hole 16 has a larger diameter than that of the fuel discharge hole 16. The ring storage hole 16a is opened and opened downward.
Reference numeral 17 denotes a fuel supply pipe which is inserted into the rear end portion Jc of the fuel injection valve J to supply fuel to the fuel injection valve J and sandwich the fuel injection valve J toward the throttle body 10 and includes the following.
Reference numeral 17a denotes an injection valve insertion hole that opens obliquely upward to the left in FIG. 3 and into which the rear end portion Jc of the fuel injection valve J is inserted. The fuel supply hole 17b penetrates from the lower end to the lower right. And then drilled.
Reference numeral 17c denotes a flange formed laterally from the fuel supply pipe 17, and a mounting hole 17d along the injection valve insertion hole 17a is formed through the flange 17c.
The fuel injection valve J is attached to the throttle body 10 by the following.
That is, the front end portion Ja of the fuel injection valve J is inserted and disposed in the fuel discharge hole 16 of the throttle body 10, and the injection valve insertion hole 17a of the fuel supply pipe 17 is inserted and disposed in the rear end portion Jc of the fuel injection valve J. An upper end surface 17c1 of the flange portion 17c is disposed in contact with a mounting boss 10a formed to protrude from the throttle body 10.
In this state, a screw 18 is inserted into the mounting hole 17d, and the fuel supply pipe 17 is screwed and fixed to the throttle body 10 by the screw 18.
According to the above, the fuel injection valve J is sandwiched between the fuel supply pipe 17 and the throttle body 10, and the O-ring R1 is provided between the outer periphery Ja2 of the tip portion Ja of the fuel injection valve J and the ring housing hole 16a. The O-ring R <b> 2 is disposed in a contracted manner between the rear end Jc and the injection valve insertion hole 17 a of the fuel supply pipe 17.
According to the above, the fuel discharge hole 16 and the atmosphere are shut off by the O-ring R1 and kept airtight, and the fuel supply hole 17b and the atmosphere are shut off by the O-ring R2 and kept airtight.
Further, as described above, the tip portion Ja of the fuel injection valve J is inserted and disposed in the fuel discharge hole 16, and at this time, an annular gap 19 is formed between the outer periphery Ja 2 of the tip portion Ja and the fuel discharge hole 16. It is formed.
The annular gap 19 is formed in this way because when the fuel injection valve J is screwed to the throttle body 10 via the fuel supply pipe 17, the tip portion Ja interferes with the fuel discharge hole 16 due to manufacturing errors thereof. This is necessary so as not to damage the tip Ja.
The fuel supply hole 17b is connected to the fuel pump through a fuel pipe (not shown), and the fuel boosted by the fuel pump is supplied into the fuel injection valve J through the fuel pipe and the fuel supply hole 17b. The fuel controlled in the valve J is injected and supplied from the injection hole Jb opened in the front end face Ja1 to the lower position of the intake passage 11b downstream of the sliding throttle valve 13 through the fuel discharge hole 16.
Reference numeral 20 denotes a top cover for closing the upper opening 12a of the sliding throttle valve guide cylinder 12, and a top cover 20 having a bottomed cup shape on the upper flange 12b of the sliding throttle valve guide cylinder 12 is provided. Screwed.
Patent 3049576

When such a conventional sliding sliding throttle valve type throttle body is mounted on an engine, the sliding throttle valve guide cylinder 12 is designed so that the sliding throttle valve 13 can close the intake passage 11 with its own weight from the viewpoint of fail-safe. Is generally disposed at an upper position in the direction of gravity. According to this, the fuel discharge hole 16 formed in the throttle body 10 is located at a lower position in the direction of gravity and obliquely upward toward the lower side of the intake passage 11b. Accordingly, the fuel injection valve J is also disposed at a position below the throttle body 10.
Here, during the operation of the engine, the fuel injected from the injection hole Jb of the fuel injection valve J into the intake passage 11b on the downstream side through the fuel discharge hole 16 is subjected to blowback from the engine. A part of the fuel blows back and adheres as fuel to the inner wall surface of the fuel discharge hole 16, stays in the fuel discharge hole 16, and further enters the annular gap 19 through the fuel discharge hole 16. To do.
According to the blow-back fuel stagnated in the fuel discharge hole 16 and the blow-back fuel that has entered the annular gap 19, the fuel is irregularly distributed in the downstream intake passage 11b during the operation of the engine. According to this, the mixed state of the fuel and air flowing in the intake passage 11b may become uneven or the mixture concentration may become temporarily high.
Further, when the stagnant fuel reaches the nozzle hole Jb, the shape of the fuel spray injected from the nozzle hole Jb is disturbed and the particle size of the fuel particles becomes non-uniform. It will be greatly disturbed.
According to the above, engine operability and exhaust gas characteristics deteriorate.
Such inconveniences are particularly noticeable when the sliding throttle valve 13 with a small amount of air directed to the engine is low and at a medium opening.
Further, while the engine is stopped, the fuel stagnating in the fuel discharge hole 16 evaporates under the influence of the ambient temperature of the engine, and this evaporated fuel is sucked from the intake passage 11b on the downstream side (not shown). When the inside of the pipe is filled, the air-fuel mixture concentration becomes excessive when the engine is restarted, and good starting is inhibited.
Furthermore, if this evaporated fuel is discharged from the intake passage 11a on the upstream side to the atmosphere side, it is not preferable from the viewpoint of preventing air pollution.
Furthermore, when the sliding throttle valve guide cylinder 12 is disposed so as to protrude upward, the fuel injection valve J is disposed so as to protrude downward, and they are disposed opposite to each other with the intake passage 11 interposed therebetween, the throttle body 10 The overall height is high, and the mountability to two-wheeled vehicles limited in storage space is poor.
In addition, since the assembly direction of the sliding throttle valve 13 in the sliding throttle valve guide cylinder 12 and the assembly direction of the fuel injection valve J to the throttle body 10 are different, their assembly performance cannot be improved.

The sliding throttle valve type throttle body according to the present invention is made in view of the above problems,
When the fuel injected from the injection hole of the fuel injection valve into the intake passage through the fuel discharge hole is blown back by the intake air pulsation of the engine, this blow-back fuel is opened to the intake passage. Prevent entry into the discharge hole and annular gap and retention. And reduce the overall height of the throttle body. Furthermore, improve the assembly of the throttle body. With the goal.

In order to achieve the above object, the sliding throttle valve type throttle body according to the present invention is configured such that the fuel in the fuel tank is boosted by a fuel pump, and this boosted fuel is attached to the throttle body. In the fuel injection device that is injected and supplied into the intake passage downstream from the sliding throttle valve via the injection valve,
For the throttle body,
A sliding throttle valve guide cylinder is continuously provided upward from the intake passage, and a sliding throttle valve that opens and closes the intake passage across the intake passage is movably disposed in the sliding throttle valve guide cylinder. ,
On the other hand, the fuel injection valve is located above the intake passage and on the engine side of the sliding throttle valve guide cylinder, and is disposed in the same direction as the movement direction of the sliding throttle valve, and the tip of the fuel injection valve Is inserted and disposed in a fuel discharge hole for drilling the throttle body and is sandwiched between the throttle body by a fuel supply pipe inserted and disposed at the rear end of the fuel injection valve,
The first feature is that the fuel injected from the fuel injection valve is supplied from above the intake passage into the intake passage downstream of the sliding throttle valve.

  In addition to the first feature, the present invention provides an injection valve insertion hole for inserting a rear end portion of the fuel injection valve into the fuel supply pipe, and a fuel supply hole for supplying fuel toward the injection valve insertion hole. The second feature is that the top cover portion that closes the upper opening portion of the sliding throttle valve guide tube is integrally formed.

  Further, in addition to the first feature, the present invention has a third feature in that the sliding throttle valve is inclined toward the engine side and the fuel injection valve is inclined in the same direction as the sliding throttle valve. To do.

  Furthermore, in addition to the first feature, the present invention has a fourth feature in which a bypass air passage connected to an intake passage upstream of the sliding throttle valve is opened in the fuel discharge hole.

According to the first aspect of the present invention, the fuel injection valve is disposed above the intake passage and on the engine side of the sliding throttle valve guide cylinder, and further in the same direction as the moving direction of the sliding throttle valve. The tip of the fuel is inserted into a fuel discharge hole that is located above the intake passage and opens downward, and fuel injected from the injection hole of the fuel injection valve passes through the fuel discharge hole. Injection is supplied toward the upper side of the intake passage.
According to the above, even when the fuel injected from the fuel injection valve is blown back by the intake pulsation in the intake passage during the operation of the engine, the fuel discharge hole opens downward and the fuel injection valve Since the annular gap formed by the tip portion and the fuel discharge hole opens downward, it is prevented that the fuel blows back and adheres to or stays in the fuel discharge hole and the annular gap.
Therefore, the boiled-back fuel that accumulates during operation of the engine is not irregularly sucked into the intake passage, and uniform and stable fuel can be supplied to the engine. Hot restartability and exhaust gas characteristics can be obtained.
Further, the fuel injection valve is arranged above the intake passage and on the engine side of the sliding throttle valve guide cylinder, and further arranged in the same direction as the moving direction of the sliding throttle valve. The sliding throttle valve guide cylinder and the fuel injection valve can be arranged above the intake passage, so that the overall height of the sliding throttle valve type throttle body can be reduced, and the storage space is limited. This is preferable for motorcycles.
Also, according to the above, the assembly of the sliding throttle valve into the sliding throttle valve guide cylinder and the assembly of the fuel injection valve to the throttle body are both assembled in the same direction from the top to the bottom. According to this, it is not necessary to reverse the throttle body during the assembly work, and the assembly performance can be greatly improved.
If attention is paid to the fuel discharge hole into which the tip of the fuel injection valve is inserted, the fuel injection valve is arranged in the same direction as the movement direction of the slide throttle valve. Are arranged in the same upward direction. According to this, at the time of injection molding of the throttle body, the fuel discharge hole can be cast and formed at the same time as the sliding throttle valve guide cylinder. It becomes unnecessary and can eliminate the leakage of the nest during casting.
Further, according to the above arrangement, the fuel injection valve is arranged on the engine side of the sliding throttle valve guide cylinder, which is suitable for opening the injection hole of the fuel injection valve into the intake passage downstream of the sliding throttle valve. In addition to this, it is suitable for shortening the overall length along the intake passage of the throttle body.

Further, according to the second feature of the present invention, the rear end portion of the fuel injection valve is inserted into the injection valve insertion hole of the fuel supply pipe, and the top of the fuel supply pipe is located at the upper opening of the sliding throttle valve guide tube. The cover portion is in contact with the fuel supply pipe, and in this state, the fuel supply pipe is screwed into the throttle body.
According to the above, the fuel injection valve whose tip is inserted into the fuel discharge hole is held by the fuel supply pipe toward the throttle body, and the upper opening of the sliding throttle valve guide cylinder is closed by the top cover. .
Here, the fuel supply pipe is integrally formed with an injection valve insertion hole for supporting the rear end portion of the fuel injection valve and a top cover portion for closing the upper opening portion of the sliding throttle valve guide cylinder. As well as assembly work.
Of these, the fact that the assembling work can be reduced eliminates the need for a flange part and a boss part for assembling, and is effective in reducing the size of the throttle body.

Further, according to the third feature of the present invention, the fuel injection valve is inclined toward the engine side. According to this, the fuel injected from the injection hole of the fuel injection valve is in response to the air flow flowing through the intake passage. Thus, the fuel is injected while being inclined toward the engine side, and the injected fuel is easy to ride on the air flow without opposing the air flow.
Further, if the sliding throttle valve and the fuel injection valve are inclined toward the engine side, the overall height of the throttle body can be lowered according to the inclination angle.

Furthermore, according to the fourth aspect of the present invention, the bypass air is sucked from the bypass air passage into the fuel discharge hole during the operation of the engine.
According to this, since air is supplied toward the fuel injected from the nozzle hole, it is possible to effectively carry the fuel into the intake passage particularly when the sliding throttle valve is low and at the middle opening degree. .

An embodiment of a sliding throttle valve type throttle body in a fuel injection device according to the present invention will be described below with reference to FIG.
In addition, about the same structure part as FIG. 3, the description is abbreviate | omitted using the same code | symbol.
First, the fuel injection valve J is disposed above the intake passage 11.
In other words, since the sliding throttle valve guide cylinder 12 is connected upward from the intake passage 11, the fuel injection valve J is disposed on the upper wall 10 b of the throttle body 10 in the same direction as the sliding throttle valve guide cylinder 12. Will be.
Second, it is arranged on the engine side E of the sliding throttle valve guide cylinder 12.
In FIG. 1, the engine side E is the left side of the sliding throttle valve guide cylinder 12.
Third, the sliding throttle valve 13 is arranged in the same direction as the moving direction XX.
In other words, it is arranged in the same direction as the sliding throttle valve guide cylinder 12.

  In order to achieve the arrangement of the fuel injection valve, the fuel discharge hole 1 is the upper wall 10b of the throttle body 10, the engine side E of the sliding throttle valve guide cylinder 12, and the sliding throttle valve 13 The lower part of the fuel discharge hole 1 opens toward the intake passage 11b on the downstream side of the sliding throttle valve 13, and the upper part of the fuel discharge hole 1 is above the fuel discharge hole XX. A ring housing hole 1a having a diameter larger than 1 is opened.

The fuel supply pipe 2 is formed by the following.
In the fuel supply pipe 2, an injection valve insertion hole 2a for inserting the rear end portion Jc of the fuel injection valve J opens downward, and an upper end of the injection valve insertion hole 2a is connected to the fuel supply hole 2b to open. .
Further, a top cover portion 2c having a bottomed cup shape for closing the upper opening portion 12a of the sliding throttle valve guide cylinder 12 is formed on the right side of the fuel supply pipe 2 so as to open downward. A lower flange 2d that abuts on the upper flange 12b of the sliding throttle valve guide cylinder 12 is formed on the outer periphery of the lower end of the top cover 2c.
That is, the fuel supply pipe 2 is integrally formed with an injection valve insertion hole 2a, a fuel supply hole 2b, and a top cover portion 2c.

The fuel injection valve J is attached to the throttle body 10 by the following.
The front end portion Ja of the fuel injection valve J is inserted into the fuel discharge hole 1, the injection valve insertion hole 2 a of the fuel supply pipe 2 is inserted into the rear end portion Jc, and the upper flange portion of the sliding throttle valve guide cylinder 12 A lower flange portion 2d of the top cover portion 2c is disposed on the top surface 12b, and an O-ring R1 is further disposed between the ring housing hole 1a and the outer periphery Ja2 of the front end portion Ja, and the rear end portion Jc and the injection valve An O-ring R2 is disposed in a contracted manner between the insertion hole 2a.
In this state, the lower flange portion 2d of the top cover portion 2c is screwed and fixed to the upper flange portion 12b of the sliding throttle valve guide tube 12 by the screw 3.
According to the above, the fuel injection valve J is sandwiched between the fuel supply pipe 2 and the throttle body 10 and attached to the throttle body 10.
Further, the upper opening portion 12 a of the sliding throttle valve guide cylinder 12 is closed by the top cover portion 2 c of the fuel supply pipe 2.
Further, the fuel discharge hole 1 and the atmosphere are blocked and hermetically maintained by the O-ring R1, and the injection valve insertion hole 2a and the atmosphere are blocked and hermetically held by the O-ring R2.
The fuel boosted by a fuel pump (not shown) is supplied into the fuel injection valve J through the fuel pipe, the fuel supply hole 2b, and the fuel inflow hole Jd. The fuel controlled in the fuel injection valve J is Then, the fuel is injected and supplied from the injection hole Jb opened in the front end surface Ja1 to the position above the intake passage 11b on the downstream side of the sliding throttle valve 13 through the fuel discharge hole 1.
On the other hand, the sliding throttle valve 13 is movably disposed in the sliding throttle valve guide cylinder 12 closed by the top cover portion 2c, and the link arm 14 is operated by operating the operating shaft 15 by the driver. The sliding throttle valve 13 controls the opening and closing of the intake passage 11 via the.

And according to the said structure, the fuel injection valve J is arrange | positioned in the upper 11c of the intake passage 11, and is arrange | positioned at the engine E side of the sliding throttle valve guide cylinder 12, and also the moving direction X of the sliding throttle valve 13 Arranged in the same direction as -X.
According to the above, the annular gap formed by the fuel discharge hole 1 opening 11 c above the intake passage 11 and opening downward, and the outer periphery Ja 2 of the tip end portion Ja of the fuel injection valve J and the fuel discharge hole 2. 4 opens downward, so that even if the blown-back fuel from the blow-back of the engine reaches the fuel discharge hole 1 and the annular gap 4, the blow-back fuel adheres to the fuel discharge hole 1 and the annular gap 4, Stagnation is deterred.
Therefore, since the fuel injected from the fuel injection valve J can be uniformly and stably supplied to the engine, good engine operability and exhaust gas characteristics can be obtained.
Further, the fact that there is no fuel accumulation means that there is no fuel evaporation when the engine is stopped, so that the hot restart can be improved and the occurrence of air pollution due to the evaporated fuel is suppressed.

Further, the sliding throttle valve guide cylinder 12 including the sliding throttle valve 13 is arranged above the intake passage 11 and the fuel injection valve J is located above the intake passage 11 11c, and the sliding throttle valve guide cylinder. 12 and on the engine side E and in the same direction as the moving direction XX of the sliding throttle valve 13, the overall height of the sliding throttle valve type throttle body 10 can be made low, like a two-wheeled vehicle. It is possible to improve the mountability to those where the storage space is limited.
Further, in the above, particularly when the fuel injection valve J is set in the same direction as the moving direction XX of the sliding throttle valve 13, both the fuel injection valve J and the sliding throttle valve 13 are throttle bodies from the same upward direction. 10 can be assembled and the assemblability can be greatly improved.
In addition, according to the above, the fuel discharge hole 1 and the sliding throttle valve guide cylinder 12 can be cast simultaneously when the throttle body 10 is injection-molded. When the fuel discharge hole 1 is used without processing, it is possible to prevent the occurrence of airtight defects due to nest leakage.
Further, since the fuel injection valve J is disposed on the engine side of the sliding throttle valve guide cylinder 12, it is easy to open the injection hole Jb of the fuel injection valve J to the intake passage 11 b on the downstream side of the sliding throttle valve 13. Furthermore, the overall length of the throttle body 10 can be effectively shortened.

Although the sliding throttle valve 13 shown in the drawing has a plate shape, the shape is not limited to a rectangular shape, a cylindrical shape, or the like. Further, the operating method of the sliding throttle valve 13 is a link arm 14. It is not limited to, and an accelerator wire or the like may be used.
Furthermore, the fact that the fuel injected from the injection hole Jb of the fuel injection valve J is discharged through the fuel discharge hole 1 is that the front end surface Ja1 of the fuel injection valve J protrudes from the downstream end of the fuel discharge hole 1. Is also included.

In addition, an injection valve insertion hole 2 a into which the rear end portion Jc of the fuel injection valve J is inserted into the fuel supply pipe 2, a fuel supply hole 2 b connected to the fuel pump, and an upper opening 12 a of the sliding throttle valve guide cylinder 12. Since the top cover portion 2c for closing is integrally formed, the number of parts can be reduced, and in particular, the number of injection molds can be reduced to one type from the conventional two types, which can greatly reduce the manufacturing cost.
Further, by screwing the fuel supply pipe 2 to the sliding throttle valve guide cylinder 12, the injection valve insertion hole 2 a is attached to the rear end portion Jc of the fuel injection valve J, and the sliding throttle valve guide cylinder 12 is positioned above. Since the top cover 2c can be attached to the opening 12a at the same time, the number of assembling steps can be reduced, which is also preferable for reducing the manufacturing cost.

A second embodiment of the present invention will be described with reference to FIG.
The same structural parts as those in FIG. 1 use the same reference numerals.
2 and FIG. 1 differ in the arrangement state of the sliding throttle valve 13.
That is, the sliding throttle valve 13 is inclined and arranged toward the engine side.
The sliding throttle valve 13 is arranged with its tip end portion 13b moving in the clockwise direction as compared with FIG.
According to this, the sliding throttle valve guide cylinder 12 that slides and guides the sliding throttle valve 13 and the fuel injection valve J including the fuel discharge hole 1 are also inclinedly arranged toward the engine side.
According to the above, the fuel injected from the injection hole Jb of the fuel injection valve J becomes the fuel flow BB inclined toward the engine side with respect to the air flow AA flowing through the intake passage 11, and therefore the air flow AA The fuel can be supplied so as to meet the above condition, thereby improving the responsiveness of the fuel supply toward the engine.
Further, since the sliding throttle valve 13 and the fuel injection valve J are inclined in the same direction toward the engine side, the overall height of the throttle body 10 can be further reduced according to the inclination angle.

Returning to FIG. 2 again, 5 is a bypass air passage, the upstream side of which opens to the intake passage 11a on the upstream side of the sliding throttle valve 13, and the downstream side thereof is the tip portion Ja of the fuel injection valve J. Open to an annular gap 4 formed by the outer circumference Ja2 and the fuel discharge hole 1.
According to the above, during operation of the engine, the air in the bypass air passage 5 is sucked into the annular gap 4 and then sucked into the intake passage 11b downstream of the sliding throttle valve 13 through the fuel discharge hole 1. Therefore, according to this, the periphery of the fuel injected from the injection hole Jb can be surrounded by the bypass air, and the fuel can be effectively conveyed into the intake passage 11b.
Further, a vortex flow is generated in the region D between the upper portion 11c of the intake passage 11 and the engine side surface 13c of the sliding throttle valve 13, and this vortex flow may disturb the fuel flow injected from the injection hole Jb. As described above, the influence of the vortex flow on the injected fuel can be reduced by surrounding the injected fuel with the bypass air.
The above-described effect is significant when the sliding throttle valve 13 where a large amount of vortex flows is generated in the region D above the intake passage 11 is low and at a medium opening degree.

Reference numeral 6 denotes a bypass adjusting screw for controlling the amount of bypass air flowing in the bypass air passage 5, and by adjusting this, for example, the amount of idle air during idling operation of the engine can be freely controlled. Bypass air can be obtained.
Further, the upstream side of the bypass air passage 5 may be opened to an air cleaner or further opened to the atmosphere.

The principal part longitudinal cross-sectional view which shows one Example of the sliding throttle-type throttle body in the fuel-injection apparatus which becomes this invention. The principal part longitudinal cross-sectional view which shows the 2nd Example of this invention. The principal part longitudinal cross-sectional view which shows the throttle body of the conventional sliding throttle valve type | mold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel discharge hole 2 Fuel supply pipe 2a Injection valve insertion hole 2b Fuel supply hole 2c Top cover part 5 Bypass air passage 10 Throttle body 11 Intake passage 11b Intake passage 12 downstream from a sliding throttle valve Sliding throttle valve guide cylinder 13 Sliding throttle valve J Fuel injection valve Ja Front end Jb Injection hole Jc Rear end

Claims (4)

The fuel in the fuel tank is boosted by the fuel pump, and the boosted fuel is injected into the intake passage downstream of the sliding throttle valve via the electromagnetic fuel injection valve attached to the throttle body. In the supplied fuel injection device,
Throttle body 10 has
A sliding throttle valve guide cylinder 12 is continuously provided upward from the intake passage 11, and a sliding throttle valve 13 that opens and closes the intake passage 11 across the intake passage 11 is provided in the sliding throttle valve guide cylinder. Arranged freely,
On the other hand, the fuel injection valve J is above the intake passage 11 and on the engine side E of the sliding throttle valve guide cylinder 12, and is further arranged in the same direction as the moving direction XX of the sliding throttle valve 13. The front end portion Ja of the fuel injection valve is inserted into the fuel discharge hole 1 for drilling the throttle body 10, and the throttle body 10 is inserted into the fuel supply pipe 2 inserted into the rear end portion Jc of the fuel injection valve J. Sandwiched between
The fuel to be injected from the fuel injection valve J is supplied from above the intake passage 11 toward the intake passage 11b on the downstream side of the sliding throttle valve 13 and is of a sliding throttle valve type in the fuel injection device. Throttle body.   An injection valve insertion hole 2a for inserting the rear end portion Jc of the fuel injection valve J into the fuel supply pipe, a fuel supply hole 2b for supplying fuel toward the injection valve insertion hole 2a, and a sliding throttle valve guide cylinder 12 A sliding throttle valve type throttle body in a fuel injection device according to claim 1, wherein a top cover portion (2c) for closing the upper opening portion (12a) is integrally formed.   2. A sliding throttle valve in a fuel injection device according to claim 1, wherein the sliding throttle valve is inclined and arranged toward the engine side, and the fuel injection valve J is inclined and arranged in the same direction as the sliding throttle valve. Type throttle body. 2. A sliding throttle valve type throttle body in a fuel injection device according to claim 1, wherein a bypass air passage (5) connected to the intake passage (11a) upstream of the sliding throttle valve (13) is opened in the fuel discharge hole.

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