JPH07111165B2 - Fuel injection valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve, and more particularly to a fuel injection valve in which a valve body that opens and closes an injection hole is made of an elastic material such as rubber.

[Prior Art] There is a fuel injection valve in which a tip end surface of a valve body is made of a rubber material in order to surely close an injection hole. An example in which this is applied to an electromagnetic fuel injection valve 58-81374) is shown in FIG.

In the figure, a valve housing 1 is a cylindrical fuel inlet joint 11
And a pipe body connected to the lower end of this via an O-ring
A known swirl nozzle 13 having a fuel injection hole 131 opening downward is held and fixed in the lower end portion of the pipe body 12 by caulking all around.

A movable core 2 is provided in the pipe body 12 as a movable body that also functions as a valve body so that it can move up and down, and a rubber layer 3 having a streamline shape toward the tip is provided on the outer periphery of a locking projection 21 formed at the tip thereof. ′ Is integrally formed by injection molding. Then, the rubber layer 3 ′ is brought into contact with the opening of the fuel flow passage 121 provided in the partition wall that partitions the swirl nozzle 13 by the urging force of the spring member 22 that urges the movable core 2 and closes it. is doing.

An electromagnetic coil 4 is provided on the outer circumference of the pipe body 12 so as to be covered with a case 14, and when the electromagnetic coil 4 is energized via an energizing pin 51 of a resin connector 5, the movable core 2 faces the fuel inlet joint 11. Is sucked upward to open the fuel flow path 121. As a result, the fuel inlet joint 11 and the movable core 2 are
Through the lateral hole 23 of the swirl nozzle 13 and the fuel passage 121.
The fuel is supplied to the engine and injected through the injection hole 131 into an unillustrated engine intake pipe.

The valve housing 1 is fixed to the intake pipe wall by a mounting plate 6.

[Problems to be Solved by the Invention] However, in the above-described conventional structure, it is difficult to perform rust-preventive plating treatment on the movable core because heat is applied during molding of the rubber layer. It uses the perfect stainless steel. In addition, stainless steel is inferior in machinability and requires a lot of time and labor for drilling as well as for machining complicated shapes such as locking projections.

The present invention is intended to solve such a problem, and an object of the present invention is to provide a fuel injection valve that does not require a movable body to be manufactured from stainless steel, and is therefore inexpensive and easy to manufacture.

[Means for Solving Problems] The structure of the present invention will be described with reference to FIG.
Inside the tubular housing 1 provided with 131, the movable body 2 whose tip 24 is located near the fuel injection hole 131 and the drive means 4 for operating the movable body 2 are provided. The movable body 2 has a cylindrical tip 24 and the fuel injection hole is formed in the tip 24.
The base end of the valve body 3 made of an elastic material that opens and closes 131 is inserted and fixed.

According to the present invention, after the movable body and the valve body are manufactured separately, the valve body is fixed to the movable body at room temperature, so that the movable body can be plated for rust prevention. Therefore, the movable body can be made of ordinary steel which is easy to cut.

Therefore, the fuel injection valve of the present invention can be manufactured at low cost and with little labor.

[Embodiment] An embodiment in which the present invention is applied to an electromagnetic fuel injection valve will be described below, focusing on differences from the conventional example.

In FIG. 1, a movable core 2 is provided so as to be vertically movable in a valve housing 1 constituted by a tubular fuel inlet joint 11 and a pipe body 12 which are connected via an O-ring. 2 has a tubular shape as a whole. A spring member 22 is provided in the upper half of the cylinder, and is arranged between a locking portion 25 formed by recessing the cylinder wall inward and the lower end surface of the fuel inlet joint 11.

A bullet-shaped rubber valve body 3 is inserted into the lower half of the movable core 2 inside the cylinder, and the base end of the movable core 2 is inserted inward by caulking the lower half cylinder wall. The valve body 3 is retained by being depressed by the depressed portion 24. The tip of the valve body 3 abuts a valve seat of an opening of a fuel passage 121 provided at the center of a partition wall at the lower end of the pipe body 12, and the fuel passage 121 is sealed by the urging force of the spring member 22.

A lateral hole 23 for fuel flow is provided in the peripheral wall of the upper half of the movable core 2.

The fuel flows through the inlet joint 11 and reaches the valve seat portion through the lateral hole 23 of the movable core 2.

When the electromagnetic coil 4 provided around the pipe body 12 is energized via the energizing pin 51 of the resin connector 5, the movable core 2 is attracted to the lower end surface of the fuel inlet joint 11 against the biasing force of the spring member 22. Further, the fuel flow path 121 is opened and the fuel is supplied to the swirl nozzle 13. The fuel supplied to the swirl nozzle 13 is fed into an intake pipe (not shown) through a fuel injection hole 131 provided in the swirl nozzle 13.

According to the above structure, the movable core is formed of ordinary steel, and rust-proof plating is applied to this, after which the valve body can be inserted into the movable core and caulked and fixed, and these can be integrally joined. It is not necessary to use expensive stainless steel, and the labor of processing can be greatly reduced.

It should be noted that a recess for preventing the valve body from coming off may be formed in advance on the cylinder wall of the movable core, and the valve body made of an elastic body may be pushed into the cylinder of the movable core with a strong force and fixed. .

Of course, the fuel injection valve to which the present invention is applied is not limited to the electromagnetic type.

[Brief description of drawings]

1 and 2 are overall sectional views of a fuel injection valve showing the present invention and a conventional example, respectively. 1 …… Housing 11 …… Fuel inlet joint 12 …… Pipe body 121 …… Fuel flow passage 13 …… Swirl nozzle 131 …… Fuel injection hole 2 …… Movable core (movable body) 24 …… Cavity part 3 …… Valve Body 4 ... Electromagnetic coil (driving means) 5 ... Resin connector

Claims (3)

[Claims] 1. A cylindrical housing having a fuel injection hole at one end thereof is provided with a movable body whose tip is located near the fuel injection hole and a drive means for operating the movable body. A fuel injection valve characterized in that a base end of a valve body made of an elastic material that is formed into a tubular shape and that opens and closes the fuel injection hole is inserted and fixed in the tip. 2. The method according to claim 1, wherein after the base end of the valve body is inserted into the cylinder of the movable body, the cylinder wall of the movable body is caulked inward to fix the valve body. The fuel injection valve described in the paragraph. 3. The fuel injection valve according to claim 1, wherein the driving means is an electromagnetic coil and the movable body is a movable core.