JPH0640924Y2 - Fuel distribution pipe for fuel injection device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fuel injection device for use in, for example, a fuel injection gasoline engine, and more particularly, to a plurality of fuel injection devices in which fuel from a pressurized fuel source is provided for each cylinder of the engine. It relates to a fuel distribution pipe distributed to a valve.

-Prior Art- A conventional fuel distribution pipe is made of a light metal extruded material such as aluminum as disclosed in Japanese Patent Publication No. 60-59427. That is, since the fuel distribution pipe is made of a rod-shaped material that is extruded in a hollow state, the distribution pipe material cut into a required length has a plurality of output ports, an input port for connecting a pressurized fuel pipe, After the return port for returning excess fuel is post-processed, both ends of the distribution pipe material are closed with stoppers or the like to complete the process.

-Problems to be solved by the invention-Therefore, in such a fuel distribution pipe using an extruded metal material, a connection screw is processed at the inlet of the input port in order to connect the pressurized fuel pipe to the input port. ,
Due to the post-processing of this connecting screw, not only is the manufacturing cost high, but it also takes a lot of time and effort to connect the pressurized fuel pipe to the input port of the fuel distribution pipe attached to the engine. There was a problem that the process was troublesome.

Further, in the conventional fuel distribution pipe as described above, it is necessary to secure a metal wall thickness that can sufficiently withstand the pressure and can process the output port, the input port, and the return port. However, the post-processing of the output port, the input port, and the return port causes a problem of poor mass production effect.

In the fuel distribution pipe described above, the input port and the return port are processed in the vicinity of both ends of the distribution pipe that is processed into a hollow rod shape, and the pressurized fuel flows through the inside of the distribution pipe. Since the return pipe to be connected is returned to the fuel tank along the outer surface of the distribution pipe and returned to the fuel tank, a return pipe in a substantially parallel state is provided side by side outside the distribution pipe, resulting in an overall structure. May become large and it may be difficult to install it in a small engine room.

In view of the problems of the conventional fuel distribution pipe for a fuel injection device as described above, an object of the present invention is to simply and without requiring post-processing on the connection portion between the pressurized fuel pipe and the input port of the distribution pipe body. It is possible to obtain a fuel distribution pipe which can be connected to a pressurized fuel pipe, which can be mass-produced to sufficiently reduce the manufacturing cost and can be downsized.

-Means for Solving the Problems-In order to achieve the above-mentioned object, the present invention provides a plurality of input ports connected to a pressurized fuel pipe and connected to a fuel injection valve. In the fuel distribution pipe for a fuel injection device in which the output ports of are arranged in the length direction, the input port is formed in a portion near one end and a plurality of the output ports arranged in the length direction on the circumferential surface are provided. Is formed and the return pipe receiver is integrally molded in the internal space corresponding to the return port formed in the state of being close to the input port, and the resin-made distribution pipe main body whose both ends are open is attached to the inlet of the input port. A connector socket having a seal ring for sealing between the pressurized fuel pipe inserted into the input port and the input port and a lock ring for preventing the bead portion of the pressurized fuel pipe from coming off. And a pair of plugs that can close both ends of the distribution pipe body and that are provided with a support block having a communication hole communicating with the pressure chamber inside the distribution pipe on the plug body opposite to the return pipe receiver. A body, a return pipe that is supported between the support block and the return pipe receiver, and connects the return port to the pressure chamber through the communication hole; and a pipe that covers both ends of the distribution pipe body. The present invention proposes a fuel distribution pipe for a fuel injection device, which includes a pair of seal caps that prevent the plugs from being pulled out from the pipe.

-Embodiment- Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings.

The fuel distribution pipe for a fuel injection device of the illustrated example is used for a part of a fuel injection device of a 4-cylinder gasoline engine, and the distribution pipe main body 1 which constitutes a main part of the fuel distribution pipe is made of a resin such as reinforced nylon. Is used to perform injection molding into a tubular shape having a non-circular cross section with both ends open. That is, the peripheral wall 1a of the distribution pipe body 1 has four output ports 2A, 2B, 2 arranged in the length direction thereof.
C, 2D is formed in a state of connecting to the internal pressure chamber 3,
Although not shown, these output ports 2A, 2B, 2
A fuel injection valve corresponding to each cylinder of a gasoline engine is attached to the output port flange 2a surrounding C and 2D.
Then, three mounting brackets 4A, 4B, 4C in which the threaded insert metal 4a is embedded are integrally molded on the outer surface of the distribution pipe body 1, and the distribution pipe body is provided through these mounting brackets 4A, 4B, 4C. 1 can be fixed to the engine body (not shown).

An input port 5 for taking pressurized fuel into an internal pressure chamber 3 is formed in a portion of the distribution pipe body 1 near a left end thereof,
A pressurized fuel pipe 7 led from a fuel pump (not shown) is connected to a connector socket 6 surrounding the input port 5. In the connector socket 6 of the illustrated example, by simply press-fitting the bead portion 7a of the pressurized fuel pipe 7, the bead portion 7a
Since the lock ring 6a and the seal ring 6b for locking and sealing are embedded, the pressurization fuel pipe 7 can be connected with one touch by simply press-fitting the end of the pressurization fuel pipe 7 into the connector socket 6 strongly.

In addition, the peripheral wall of the distribution pipe body 1 close to the input port 5
A return port 8 that can discharge excess fuel is formed in 1a,
Excess fuel can be discharged to the outside from the return pipe joint 9 outside the return port 8. In the pressure chamber 3 corresponding to the inner end of the return port 8, a return pipe receiver 10 having a connection hole 10a communicating with the return port 8 is integrally formed. That is, the end portion 11a of the return pipe 11 that is incorporated into the distribution pipe body 1 in a state of being close to the peripheral wall 1a of the distribution pipe body 1 is inserted into and supported by the connection hole 10a of the return pipe receiver 10. This return pipe 11
Is made of a lightweight metal pipe such as aluminum, and the opposite end 11b thereof is supported by a support block 14a of a second plug 14 described later.

On the other hand, external seal flanges 1b, 1c and end holes 1d, 1e are formed at both open ends of the distribution pipe body 1, and these end holes 1d, 1e have O-rings 12 on the outer peripheral surface, respectively. The first plug body 13 and the second plug body 14 which are located at the position are inserted, and the first plug body 13 and the second plug body 14 are attached to the corresponding seal flange 1.
Withdrawal from the distribution pipe main body 1 is prevented by the seal caps 15A and 15B curled by b and 1c. And, on the inner surface of the second plug body 14 which is resin-molded into a non-circular cross-sectional shape,
As shown in the fifth illustration, the support block 14a is integrally molded. That is, a support hole 16 facing the connection hole 10a is formed in the support block 14a, and a communication hole 17 communicating with the right end of the pressure chamber 3 is formed in the support hole 16a. When the return pipe 11 is attached to the support hole 16, the return pipe 11
The internal space of is connected only to the left end of the pressure chamber 3 through the communication hole 17.

Since the fuel distribution pipe for the fuel injection device according to the illustrated embodiment has the above-described structure, since the connector socket 6 is integrally formed with the distribution pipe main body 1 formed by resin molding, the pressurized fuel pipe 7 and the input port 5 are connected. Since no post-processing is required for the connecting portion, the manufacturing cost is low, and the connection can be completed by simply strongly inserting the tip of the pressurized fuel pipe 7 having the bead portion 7a into the connector socket 6. Therefore, there is an advantage that the connection work on the assembly line of the vehicle body can be performed quickly and easily.

Further, in the illustrated example, since the distribution pipe main body 1 is resin-molded by injection molding, not only the overall weight can be reduced, but also the post-processing of the distribution pipe main body 1 is not required.
The production price can be reduced sufficiently by mass production. Also, in the same fuel distribution pipe, in order to secure the positional accuracy of the fuel injection valve with respect to the engine manifold, the output ports 2A, 2B,
Although the distance accuracy between 2C and 2D is required, the accuracy of the same distance L can be secured by molding the distribution pipe body 1 with resin. The inner surface of the distribution pipe body 1 through which the pressurized fuel flows is desired to have a small surface roughness for the purpose of preventing pressure loss and the like, but the distribution pipe body 1 is formed by injection molding. A smooth inner surface of 1 can be obtained.

In the actual case, the pressurized fuel introduced from the input port 5 into the distribution pipe body 1 is distributed to the respective output ports 2A, 2B, 2C, 2D while flowing rightward from the left end portion of the distribution pipe body 1. Since the surplus fuel is collected from the right end of the return pipe 11, the bubbles that have entered the pressure chamber 3 gradually flow to the right of the pressure chamber 3 and are discharged to the outside from the right end of the return pipe 11. Therefore, there is an effect of removing bubbles inside the pressure chamber 3, and the restartability of the engine can be improved. In the case of the present invention, the return pipe
Since 11 is incorporated into the distribution pipe body 1, the overall external dimensions are extremely small, and it can be sufficiently incorporated even in a small engine room.

-Effect of the invention-As is clear from the above description, according to the present invention, the connector socket is integrally molded at the inlet of the input port of the distribution pipe body to be resin molded, and the connector socket has the bead portion. Since the pressurized fuel pipe is inserted, it is possible to provide an advantageous structure in which the pressurized fuel pipe can be connected with one touch without requiring post-processing on the distribution pipe body. Further, in the present invention, since the return pipe is assembled inside the distribution pipe main body which is resin-molded, it is possible to obtain a small fuel distribution pipe which is lightweight, has a high mass productivity and is highly producible. Further, in the present invention, since the distribution pipe main body is injection-molded, necessary dimensional accuracy such as between output ports can be easily ensured, and an inner surface with a small pressure loss can be obtained.

[Brief description of drawings]

1 is a plan view of the fuel distribution pipe according to the present invention, FIG. 2 is a cross-sectional view of the fuel distribution pipe, FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2, and FIG. 4 is FIG. FIG. 5 is a sectional view taken along line IV-IV of FIG. 5, and FIG. 1 …… Distribution pipe main body, 2A to 2D …… Output port, 3 …… Pressure chamber, 5 …… Input port, 6 …… Connector socket, 7 …… Pressurized fuel pipe, 7a …… Bead part, 8 …… Return port, 10 …… Return pipe receiver, 11 …… Return pipe, 13,14 …… Plug, 14a …… Support block, 15A, 15B …… Seal cap.

Claims (1)

[Scope of utility model registration request] 1. A fuel component for a fuel injector, wherein an input port connected to a pressurized fuel pipe is formed at a portion near one end, and a plurality of output ports connected to a fuel injection valve are arranged in a longitudinal direction. In the pipe, the input port is formed at a portion near one end and a plurality of the output ports arranged in the lengthwise direction are formed on the circumferential surface, and the return port is formed in the state of being close to the input port. A return pipe receiver integrally molded in the internal space, and a resin distribution pipe main body whose both ends are open; the pressurized fuel pipe attached to the inlet of the input port and inserted into the input port; and the input port. A connector socket having a seal ring that seals between the two and a lock ring that prevents the bead portion of the pressurized fuel pipe from coming off, and both ends of the distribution pipe body can be closed. A pair of plugs provided with a support block having a communication hole communicating with the pressure chamber inside the distribution pipe on the plug opposite to the return pipe receiver, and supported between the support block and the return pipe receiver. A return pipe that connects the return port to the pressure chamber via the communication hole, and a pair of seal caps that cover both ends of the distribution pipe body and prevent the plugs from being withdrawn from the distribution pipe. And a fuel distribution pipe for a fuel injection device.