JPH06101593A - Fuel injection system for internal combustion engine - Google Patents

Abstract

PURPOSE:To provide a fuel injection system with a mounting property equivalent to that of a top feed type fuel injection valve and also to always cool a solenoid coil using fuel in the same manner as a side feed type fuel injection valve, while facilitating removal of vapor generated inside a fuel injection valve. CONSTITUTION:An outer case 14 is provided around a fuel injection valve 12, the diameter of the outer case 14 being greater by a predetermined value than the outside diameter of the fuel injection valve. The upper end of the outer case is open to a passage 131 located in a deliverly pipe and the lower end of the case is sealed by the lower portion of the fuel inlet 12 of the fuel injection valve. A blocking member for blocking the direct flow of fuel from a downward passage 142 to an upward passage 143 is disposed in the space between the fuel injection valve and the outer case, and fuel flowing through the downward passage or upward passage cools a solenoid coil. Therefore, even if the delivery pipe is installed at the head portion of the fuel injection valve, the solenoid coil can always be cooled by the fuel, and vapor generated inside the valve is easily discharged via the delivery pipe, so that high- temperature restart performance is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for an internal combustion engine, and more particularly to a fuel injection device capable of constantly cooling a solenoid coil.

[0002]

2. Description of the Related Art In recent years, internal combustion engines for automobiles are mainly those to which a so-called electronic fuel injection device is applied. In this electronic fuel injection device, the fuel pumped up from the fuel tank by the fuel pump is supplied to the delivery pipe installed along the internal combustion engine through the fuel pipe.

Fuel is injected into the intake pipe from a fuel injection valve arranged so as to be inserted into the delivery pipe at a right angle. The amount of injected fuel changes the excitation time of a solenoid coil built in the fuel injection valve. Controlled by. Further, the fuel injection valve needs to be installed as close as possible to the intake valve of each cylinder in order to reduce the amount of fuel adhering to the inner wall surface of the intake pipe.

As the fuel injection valve, there are a top feed type which supplies fuel from the head of the fuel injection valve and a side feed type which supplies fuel from almost the center of the fuel injection valve. FIG. 5 is a mounting view of a top-feed type fuel injection valve, in which a delivery pipe 52 is attached to the head of the fuel injection valve 51. That is, the fuel injection valve 51 is connected to the delivery pipe 52 only by inserting the head of the fuel injection valve 51.

The fuel is branched from the delivery pipe, descends in the fuel injection valve, and is injected into the intake pipe from a nozzle provided at the tip of the fuel injection valve. That is, when a top feed type fuel injection valve is used, the delivery pipe is installed on the head, so the fuel injection valve itself has a simple shape, and the intake air is reduced in order to reduce the amount of fuel adhering to the inner wall surface of the intake pipe. In the intake pipe 53 in the immediate vicinity of the valve or in the cylinder head 5 of the internal combustion engine
It is possible to directly dispose the fuel injection valve on the valve 4.

However, when the internal combustion engine stops at a high temperature, the fuel retained in the fuel injection valve from the delivery pipe to the nozzle at the tip of the fuel injection valve may evaporate, and so-called vapor lock may deteriorate the restartability. Furthermore, since the heat generated in the internal combustion engine is directly conducted to the solenoid coil built in the fuel injection valve, it is necessary to take measures such as increasing the insulation grade or increasing the number of turns to ensure the certainty of valve opening. there were.

In order to solve the above problems, a side feed type fuel injection valve has been proposed. FIG. 6 is a cross-sectional view of the side-feed type fuel injection valve.
Is inserted into the delivery pipe 62 up to almost the center, and the solenoid coil 63 is cooled by the fuel flowing in the delivery pipe.

Therefore, it is not necessary to take measures such as increasing the insulation grade of the solenoid coil or increasing the number of turns. Furthermore, even if the flow of fuel stops due to the stop of the internal combustion engine and the fuel evaporates to generate vapor, the vapor is discharged through the delivery pipe when the internal combustion engine is restarted, so that the occurrence of vapor lock can be reduced.

[0009]

However, in the side-feed type fuel injection valve, since the distance from the delivery pipe to the nozzle is short, mounting in the vicinity of the intake valve is limited and the amount of fuel adhering to the inner surface of the intake pipe increases. This is unavoidable, and fuel consumption will deteriorate. Further, it is necessary to form the port portion 64 that supports the fuel injection valve integrally with the delivery pipe 62, which complicates the shape of the delivery pipe and increases the number of manufacturing steps.

The present invention has been made in view of the above problems, and not only has the same mountability as that of the top-feed type fuel injection valve but also cools the solenoid coil at all times like the side-feed type fuel injection valve. It is an object of the present invention to provide a fuel injection device that is capable of achieving the above-mentioned characteristics and that can easily remove vapor generated in the fuel injection valve.

[0011]

A fuel injection device for an internal combustion engine according to a first aspect of the invention includes at least a solenoid coil and a valve body whose open / closed state is controlled depending on whether or not power is supplied to the solenoid coil. One fuel injection valve and a delivery pipe having a fuel passage axially passing therethrough for supplying fuel to the at least one fuel injection valve, and the delivery pipe is penetrated for each at least one fuel injection valve. The fuel flow valve that opens upstream of the fuel flow path and supplies fuel to the valve body of the fuel injection valve, and the downstream flow path of the fuel flow path that penetrates the delivery pipe The ascending flow path returning to the delivery pipe is installed, and the fuel flow path in the delivery pipe is provided with at least one fuel injection valve between the opening of the descending flow path and the opening of the ascending flow path. Cut off the flow With installing a blocking member, disposed at least one-way descending channel and upward flow path around the solenoid coil.

In the fuel injection device for an internal combustion engine according to the second aspect of the present invention, the shut-off member is an electrode connector having a terminal wire for supplying a current to a solenoid coil incorporated in the fuel injection valve. A fuel injection device for an internal combustion engine according to a third aspect of the present invention includes an integrated harness connected to an electrode connector, and the direction in which the electrode connector is inserted into the delivery pipe and the direction in which the integrated harness and the terminal wire are connected coincide with each other. Let

A fuel injection device for an internal combustion engine according to a fourth aspect of the present invention has, for each at least one fuel injection valve, an outer case having a diameter larger than a predetermined value by more than an outer diameter of the fuel injection valve. A separating member that separates the space between the fuel injection valve and the fuel injection valve into a descending passage and an ascending passage is disposed.

[0014]

According to the fuel injection device for the internal combustion engine of the first aspect of the invention, the fuel is delivered to the delivery pipe, the descending passage and the ascending passage even when the fuel injection valve is connected to the delivery pipe at the rear end side. Flow again along the flow path returning to the delivery pipe. According to the fuel injection device for the internal combustion engine of the second invention, the terminal wire for supplying the drive current of the solenoid coil is embedded in the blocking member.

According to the fuel injection device for an internal combustion engine of the third aspect of the present invention, since the inserting direction of the electrode connector into the delivery pipe and the connecting direction of the integrated harness and the terminal wire are the same, the electrode connector is delivered to the delivery pipe. When inserted in, the connection between the terminal wire and the integrated harness is also made. According to the fuel injection device for the internal combustion engine of the fourth aspect of the invention, the descending flow path and the ascending flow path are configured by dividing the outer case with the separating member, and the structure is simplified.

[0016]

1 is a front sectional view of a fuel injection device according to the present invention, in which a fuel injection valve 12 is directly attached to a cylinder head 11.
Is attached. The delivery pipe 13 is provided with a channel 131 penetrating in the axial direction, and the fuel pumped up from a fuel tank (not shown) by a fuel pump (not shown) flows in the direction of arrow A.

An outer case 1 is provided around the fuel injection valve 12.
4 is installed, and the upper end of the outer case 14 opens into the flow path 131 penetrating the delivery pipe 13. The lower end of the outer case 14 extends to the fuel intake port 121 provided in the fuel injection valve 12, and is sealed at the lower part of the fuel intake port 121. FIG. 2 is a horizontal partial sectional view of the fuel injection valve 12, where (a) shows an XX section, (b) shows a YY section, and (c) shows a zz section.

As shown in FIG. 2A, the fuel injection valve 12
In the space between the outer case 14 and the outer case 14, a resin member 141 is installed in a portion perpendicular to the flow path 131 to separate the descending flow path 142 and the ascending flow path 143. That is, a portion of the valve body of the fuel injection valve 12 and the resin member 141 on the outer periphery thereof that penetrates the flow passage 131 in the delivery pipe 13 functions as a blocking member, and all the fuel flowing in the delivery pipe 13 flows into the descending flow passage 142. .

It is also possible to form the entire blocking member as an integral structure with the valve body. Further, as shown in FIG. 2B, the resin member 141 includes the fuel injection valve 12 and the outer case 1.
The space between 4 and 4 is also filled. Therefore, the solenoid coil 122 is cooled by the fuel flowing in from the upstream opening 145 and flowing in the descending passage 142, and the fuel flowing in the ascending passage 143 and returning from the downstream opening 146 to the passage 131.

Further, as shown in FIG. 2C, a part of the fuel flowing around the solenoid coil flows into the fuel intake port 121 of the fuel injection valve 12, and when the solenoid coil 122 is excited, the intake pipe from the injection hole 125. And the remaining fuel returns to the ascending flow path 143. An air assist hole 126 is connected to the injection hole 125, and an upstream end of the air assist hole 126 is connected to, for example, an upstream side of an intake throttle valve (not shown) so that the injected fuel collides with the intake air to promote atomization of the fuel. .

A terminal wire 123 for transmitting a signal for exciting the solenoid coil 122 penetrates through the valve body 12 and is connected to a connection terminal 124 provided on the head of the fuel injection valve. The connection terminal 124 projects from the upper surface of the delivery pipe 13. That is, the terminal wire 123 penetrates the blocking member, that is, the valve body 12 and the resin member 141 that penetrate the inside of the delivery pipe, and the blocking member constitutes an electrode connector.

FIG. 3 is a part of a WW local sectional view of the fuel injection valve 12. The upper surface of the delivery pipe 13 is a resin cover 13
The integrated harness 133 is attached inside the resin cover 132. Integrated harness 1
Reference numeral 33 is a printed circuit board extending in the axial direction of the delivery pipe, for example, and a plurality of electric conduction paths 134 are printed.

A receptacle 135 is provided at a position corresponding to the fuel injection valve 12, and is fitted with a connection terminal 124 provided on the upper surface of the delivery pipe 13. That is, according to the fuel injection device of the present invention, the connection between the terminal wire 123 and the integrated harness 133 is completed by inserting the fuel injection valve 12 into the delivery pipe 13.

Therefore, the integrated harness 133 and the control unit (not shown) are provided with a multi-core prefabricated cable (not shown).
If the connection is made by (1), the electrical connection between each fuel injection valve 12 and the control unit will be completed, and the number of cabling steps will be reduced. FIG. 4 is a mounting view of the fuel injection device according to the present invention, in which the delivery pipe is attached to the head of the fuel injection valve as in the conventional top-feed type fuel injection valve, so that the cylinder head 41 near the intake valve shaft is provided. It is possible to directly arrange the fuel injection valve.

Although the embodiment in which the fuel injection valve is inserted in the delivery pipe and the valve body itself is used as the shut-off member has been described above, the conventional top feed type fuel injection in which the delivery pipe is installed at the head of the fuel injection valve has been shown. It is also possible to dispose a plate-shaped blocking member in the delivery pipe so that the fuel is disposed in the same arrangement as the valve so that the fuel flows through the descending passage and the ascending passage arranged around the fuel injection valve.

[0026]

According to the fuel injection device of the first aspect of the present invention, as with the top-feed type fuel injection valve, it is easy to connect to the delivery pipe and attach it in the vicinity of the intake valve, and the side-feed type fuel injection device is also provided. Like the valve, the fuel flowing in the delivery pipe not only allows the solenoid coil to be cooled at all times, but also facilitates vapor removal during high temperature restart.

According to the fuel injection device of the second invention, since the electrode connector is installed on the head of the fuel injection valve, the fuel injection valve can be miniaturized, and for example, it is narrow near the intake valve shaft. It is also possible to install it in a different space, and to install the fuel injection valve closer to the intake pipe. According to the fuel injection device of the third invention, it is possible to insert the electrode connector into the delivery pipe and simultaneously complete the connection between the terminal wire and the integrated harness. The connecting step and the connecting step can be combined into one step, and the assemblability can be improved.

According to the fuel injection device of the fourth aspect of the present invention, the outer case covering the outer periphery of the fuel injection valve is installed, and the separating member is arranged at a portion above the upper end of the solenoid coil. The fuel injection device according to the invention can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view of a fuel injection valve.

FIG. 2 is a horizontal partial sectional view of a fuel injection valve.

FIG. 3 is a vertical partial sectional view of a fuel injection valve.

FIG. 4 is a mounting view of a fuel injection valve according to the present invention.

FIG. 5 is a mounting view of a top feed type fuel injection valve.

FIG. 6 is a sectional view of a side-feed type fuel injection valve.

[Explanation of symbols]

 11 ... Cylinder head 12 ... Fuel injection valve 121 ... Fuel intake port 122 ... Solenoid coil 123 ... Terminal wire 124 ... Connection terminal 13 ... Delivery pipe 131 ... Flow path 132 ... Resin cover 133 ... Integrated harness 134 ... Electrical conduction path 135 ... Receptacle 14 Outer case 141 Resin member 142 Downward flow channel 143 Upward flow channel

Claims (4)

[Claims] 1. At least one fuel injection valve having a solenoid coil and a valve body whose open / closed state is controlled depending on whether or not power is supplied to the solenoid coil, and fuel is supplied to the at least one fuel injection valve. A fuel injection device for an internal combustion engine, comprising: a delivery pipe having an axially penetrating fuel flow passage, and a fuel flow passage penetrating the delivery pipe for each of the at least one fuel injection valve. Opening on the upstream side of
A descending flow path for supplying fuel to the fuel injection valve, and an opening on the downstream side of the fuel flow path penetrating the delivery pipe,
An ascending flow path for returning fuel near the valve body of the fuel injection valve to the delivery pipe, and the descending flow path provided for each of the at least one fuel injection valve in the fuel flow path in the delivery pipe. A blocking member that blocks the flow of fuel directly from the opening of the ascending passage to the opening of the ascending passage, and at least one of the descending passage and the ascending passage is disposed around the solenoid coil. A characteristic fuel injection device for an internal combustion engine. 2. The fuel injection device for an internal combustion engine according to claim 1, wherein the cutoff member is an electrode connector having a built-in terminal wire for supplying a current to a solenoid coil built in the fuel injection valve. 3. An integrated harness connected to the electrode connector is provided, and a direction in which the electrode connector is inserted into the delivery pipe and a direction in which the integrated harness and the terminal wire are connected are made to coincide with each other. The fuel injection device for an internal combustion engine according to claim 2, characterized in that: 4. An outer case having a diameter larger than an outer diameter of the fuel injection valve by a predetermined value or more is provided for each of the at least one fuel injection valve, and a space between the outer case and the fuel injection valve. 2. The fuel injection device for an internal combustion engine according to claim 1, further comprising a separating member that separates the fuel into the descending passage and the ascending passage.