JP3166090B2 - Manufacturing method of fuel delivery pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to supplying fuel supplied from a fuel pressurizing pump of a fuel injection type automobile engine to each intake passage or each cylinder of the engine through a fuel injector (injection nozzle). In particular, the present invention relates to a connection structure between a main pipe having a fuel passage and a socket for mounting a fuel injection valve.

[0002]

2. Description of the Related Art A conventional fuel delivery pipe is disclosed in, for example, Japanese Utility Model Laid-Open No. 57-84362, "Delivery Pipe for Fuel Injection Type Internal Combustion Engine" and Japanese Utility Model Laid-Open No. 59-40577, "Delivery Pipe". A plurality of cylindrical sockets for receiving an injection shaft of an injection valve are arranged at regular intervals on a main pipe having a circular or square cross section. The cylindrical socket is classified into a type that is welded to the main pipe and a type that is integrally formed with the main pipe.

[0003] Since the fuel injection valve must be mounted to the intake hole of the intake manifold of the engine with its axis aligned accurately, the spacing between sockets and the mounting angle must be within tight tolerances. No. For this reason, the type in which the socket is welded to the metal main pipe requires man-hours and time to perform complicated and precise processing in manufacturing the socket itself, and furthermore, in the connection work between the socket and the main pipe, tacking and brazing are required. In order to obtain high dimensional accuracy after the process, a 100% inspection process by mold matching is required, leading to an increase in cost.

[0004] In the type in which the socket is formed integrally with the main pipe, as disclosed in, for example, Japanese Utility Model Application Laid-open No. Sho 59-107050, "Delivery Pipe Apparatus", the entire fuel delivery pipe is made of aluminum die cast or aluminum extruded material. , The surface treatment is performed after the whole is formed, so that the surface treatment is likely to be non-uniform, and the mold is required to have a draft angle, so that the wall thickness increases and the weight increases,
There are drawbacks in that it is difficult to find defects such as internal nests, and that quality cannot be guaranteed, and that it is difficult to deal with design changes.

In Japanese Utility Model Laid-Open No. 60-14276, "fuel distribution pipe for internal combustion engine", the entire fuel delivery pipe is formed of a composite material in which a reinforcing fiber material is mixed with a synthetic resin, but the heat resistance is insufficient. There are drawbacks such as the fact that the whole is bent or distorted due to expansion and contraction due to heat and deformed, and that the synthetic resin swells and deteriorates when the fuel passes through the inside.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to form a part of a fuel delivery pipe with a resin, thereby facilitating processing and securing rigidity to suppress deformation and prevent oil leakage. It is in. Another object of the present invention is to
An object of the present invention is to manufacture a fuel delivery pipe in which the positioning accuracy between the sockets is enhanced and the breakage and oil leakage from the connection portion with the fuel injection valve are prevented. Yet another object of the present invention is to eliminate the drawbacks of the fuel delivery pipe including a resin part, suppress deformation due to heat, and enable a compact design.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a communication pipe having a fuel passage extending in a straight line therein, and a communication pipe positioned at a predetermined interval along a longitudinal direction of the communication pipe. A method for manufacturing a fuel delivery pipe comprising a cylindrical socket for mounting a fuel injection valve,
Punch grooves are formed along the outer peripheral shape of the fuel supply hole at predetermined intervals along the longitudinal direction of the communication pipe, and a cylindrical socket is provided around the communication pipe so as to cover each of the punch grooves. Molding, and then punching out each punching groove to remove an internal region, forming a fuel supply hole, and connecting the fuel passage with the inside of the cylindrical socket, by a method of manufacturing a fuel delivery pipe. Achieved.

According to such a configuration, after welding parts such as flanges and branch pipes onto the communication pipe, a plurality of cylindrical sockets are simultaneously molded and set at predetermined positions on the communication pipe. As a result, the dimensional accuracy between the sockets is improved, the connection with the fuel injection valve is reliably performed, and breakage and oil leakage can be prevented. Since the molding is performed at a relatively low temperature compared to the high temperature at the time of welding, thermal deformation can be prevented and dimensional accuracy can be maintained. Since the fuel supply hole does not penetrate at the time of molding, it is possible to prevent the molded resin from entering the fuel supply hole. Further, by changing the mold for molding, there is obtained an advantage that design change can be easily dealt with. Other features and advantages of the present invention will become apparent from the following description in which reference is made to the embodiments of the accompanying drawings.

[0009]

FIG. 1 shows a primary assembly (sub-assembly) 10 before molding in a process for manufacturing a fuel delivery pipe using the method of the present invention.
Three punching grooves 16 are formed at regular intervals in the longitudinal direction of the communication pipe 11 having a fuel supply passage 17 therein. The area surrounded by the punched groove 16 forms a dummy cover 19. As will be described later, a cylindrical socket for mounting the fuel injection valve is molded with synthetic resin so as to cover each punching groove 16 and the dummy cover 1 is formed.
9 is stamped out and removed.

The communication pipe 11 has a circular cross section, and is provided at one end thereof with a flange 13 for introducing high-pressure fuel delivered from the fuel pump through a pressure regulating valve, and at the other end thereof. A connection pipe 14 for sending surplus fuel to another cylinder or fuel tank is attached. The illustrated primary assembly 10 is used for a 6-cylinder V-type engine in which one pair is combined. A thick and solid bracket 15 for attaching the fuel delivery pipe to the engine is further fixed to the communication pipe 11.

FIG. 2 and FIG. 3 show the detailed shape of the punching groove 16, and the bottom end of the groove 16 extends to near the inner periphery of the communication pipe 11 to form a thin portion. The punching groove 16 can be easily processed by using a machine tool or the like provided with a numerical control system.

FIG. 4 shows a state in which the cylindrical socket 12 for mounting the fuel injection valve is molded so as to cover each punching groove 16 of the primary assembly 10 shown in FIG. As shown in cross section in FIG. 6, the socket 12 is composed of a tubular extension 21 for receiving the fuel injection valve and a band 22 wound around the communication pipe 11, and these are integrally molded with synthetic resin. Have been.

As shown in cross section in FIG. 5, after the socket 12 is molded, a tool is inserted into the socket from the cylindrical extension 21 and the dummy cover 19 is moved along the punched groove 16 by the tip of the tool. And a fuel supply hole 18 is formed. The dummy cover 19 that has fallen to the bottom of the fuel passage 17 is discharged from the central opening 23 of the flange 13 to the outside.

Thus, as shown in FIGS. 5 and 6, the fuel passage 17 and the inside of the cylindrical socket 12 communicate with each other. As a result, the fuel supplied from the central opening 23 of the flange 13 passes through the fuel supply passage 17 inside the communication pipe 11 and from the hole 18 in the side wall to the fuel injection valve mounted in the cylindrical extension 21 of the socket. Is sent. The surplus fuel is sent from the fuel supply passage 17 through the connection pipe 14 to another cylinder or a fuel tank.

The molding of the socket 12 is performed by the communication tube 1.
It is desirable that the flange 13, the connecting pipe 14, and the bracket 15 be brazed or welded on the surface 1, subjected to a surface treatment as necessary, and then subjected to molding. According to this method, it is possible to prevent contamination of the surface and a reduction in corrosion resistance that occur when welding or brazing is performed after the surface treatment.

FIGS. 7 to 9 show another embodiment of the present invention. The present invention is applied to a fuel delivery pipe of the type in which the center axis of the socket is offset without crossing the center axis of the fuel supply passage. It is an example of applying the method of the invention.

FIG. 7 shows a primary assembly (sub-assembly) 40 before molding. Three recesses are provided at regular intervals on the longitudinal side of a communication pipe 41 having a fuel supply passage 47 therein. A place 50 is provided.

As shown in FIG. 8, a pair of punched grooves 56 and 57 are formed in each recess 50 so as to face each other. Areas surrounded by the punched grooves 56 and 57 constitute dummy covers 58 and 59. Each of the punched grooves 56 and 57 extends to near the inner periphery of the communication pipe 41 to form a thin portion. These punched grooves 56 and 57 can be easily processed by using a machine tool equipped with a numerical control system. As described later, each punched groove 56, 5
A cylindrical socket for mounting the fuel injection valve is molded so as to cover 7, and the dummy covers 58 and 59 are punched out and removed.

The communication pipe 41 has a circular cross section. A flange 43 is provided at one end of the communication pipe 41 for introducing high-pressure fuel delivered from the fuel pump through a pressure regulating valve. A connection pipe 44 for sending surplus fuel to another cylinder or fuel tank is attached. Communication pipe 4
Further, a thick and rigid bracket 45 for attaching the fuel delivery pipe to the engine is fixed to 1.

FIG. 9 shows a state in which the cylindrical socket 42 for mounting the fuel injection valve is molded so as to cover the punched grooves 56 and 57 of the primary assembly 10 shown in FIG. The socket 42 includes a tubular extension portion 51 that receives the fuel injection valve and a band portion 5 that is wound around the communication pipe 41.
2, and these are integrally molded with a synthetic resin.

In the state shown in FIG. 9, a tool is inserted from the cylindrical extension portion 51 of the socket 42, and the dummy covers 58, 59 are punched out from the outside along the punched grooves 56, 57 by the tip of the tool. Feed holes are created. The dummy covers 58 and 59 that have fallen to the bottom of the fuel passage 47
It is discharged to the outside through the central opening 53 of the flange 43 and removed.

Thus, the fuel passage 47 and the cylindrical socket 4
2 will communicate with the inside. As a result, the flange 4
The fuel supplied from the central opening 53 of the third through the fuel supply passage 47 inside the communication pipe 41, flows from the hole made after the dummy cover 58 is removed in the direction D (FIG. 7), and flows into the cylindrical shape of the socket. The fuel is supplied to the fuel injection valve installed in the extension part 21. The surplus fuel flows from the hole made after the dummy cover 59 is removed in the direction E (FIG. 7),
The fuel is sent from the fuel passage 47 to another cylinder or a fuel tank through the connection pipe 44.

The molding of the socket 42 is performed by the communication pipe 4.
It is desirable that the flange 43, the connecting pipe 44, and the bracket 45 be brazed or welded on the surface 1 and subjected to a surface treatment as required, and then the molding be performed. According to this method, it is possible to prevent contamination of the surface and a reduction in corrosion resistance that occur when welding or brazing is performed after the surface treatment.

[0024]

As described above in detail, according to the present invention, a part of the fuel delivery pipe is formed of resin, so that a part of the machining process can be omitted and the processing becomes easy. Since the pitch between the sockets and the mounting angle of the sockets are determined at the time of molding, accurate positioning is possible. If molding is performed after the welding operation, it is possible to prevent contamination of the surface and a decrease in corrosion resistance. In the molding, since the molding is performed at a relatively low temperature as compared with the high temperature at the time of welding, thermal deformation can be prevented and dimensional accuracy can be maintained.

Since the fuel supply hole does not penetrate at the time of molding the socket, it is possible to prevent the molded resin from entering the fuel supply hole.
Further, by changing the mold for molding, there is obtained an advantage that design change can be easily dealt with. In this way, a fuel delivery pipe having sufficient rigidity and dimensional accuracy is obtained, and the technical effects are extremely remarkable, such as an improvement in quality and a reduction in cost.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a primary assembly of a fuel delivery pipe using a manufacturing method according to the present invention.

FIG. 2 is a partially broken side view showing a punching groove on a communication pipe in an enlarged manner.

FIG. 3 is a longitudinal sectional view of a punched groove portion cut along a line AA in FIG. 2;

FIG. 4 is a perspective view showing a completed assembly of a fuel delivery pipe using the manufacturing method according to the present invention.

5 is a partially broken longitudinal sectional view of the fuel delivery pipe of FIG. 4 cut along an axial direction.

FIG. 6 is a longitudinal sectional view of the socket portion taken along line BB of FIG. 5;

FIG. 7 is a plan view illustrating a primary assembly of a fuel delivery pipe using a manufacturing method according to another embodiment of the present invention.

FIG. 8 is a side view of the primary assembly according to the embodiment of FIG. 7;

FIG. 9 is a perspective view showing a completed assembly of a fuel delivery pipe using the manufacturing method according to the embodiment of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Primary assembly 11 Communication pipe 12 Socket 16 Punching groove 17 Fuel passage 18 Fuel supply hole 19 Dummy cover 20 Fuel delivery pipe

Claims (1)

(57) [Claims] 1. A fuel pipe comprising: a communication pipe having a fuel passage extending in a straight line therein; and a cylindrical socket for mounting a fuel injection valve positioned at a predetermined interval along a longitudinal direction of the communication pipe. In the method for manufacturing a UEL delivery pipe, punching grooves are formed at predetermined intervals along the outer peripheral shape of the fuel supply hole along the longitudinal direction of the communication pipe, and the punching grooves are formed so as to cover the punching grooves. A socket is molded around the communication pipe, and then each punched groove is punched out to remove an internal region, a fuel supply hole is formed, and the fuel passage and the inside of the cylindrical socket are communicated. A method for manufacturing a fuel delivery pipe.