JPH048308Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electromagnetic fuel injector used in an internal combustion engine.

[Prior Art] Conventionally, this type of electromagnetic fuel injector is disclosed in, for example, Japanese Utility Model Application Publication No. 59-22982.
In this publication, a conical valve seat part having a fuel injection hole at the front end is connected to the front part of a cylindrical slide hole in the valve seat. Further, an on-off valve having a valve element at the front end of a cylindrical slide member is inserted into the slide hole so as to be able to reciprocate in the axial direction thereof. The cylindrical hollow part of the slide member serves as a fuel passage, and a communication hole is provided at the front end of the slide member to communicate the inside and outside of the slide member. Then, the on-off valve is reciprocated by electromagnetic force and the spring force of the spring, and the valve element is detached from and brought into contact with the valve seat, so that the pressurized fuel is passed from the fuel passage of the slide member to the flow hole of the slide hole. The fuel is injected intermittently from the fuel injection holes.

However, in this publication, most of the sliding member is guided by the slide hole in the valve seat, so the frictional resistance during the reciprocating operation of the opening/closing valve is large, and the responsiveness of the operation may be impaired. .

Therefore, in order to improve the responsiveness of the opening/closing valve operation, front and rear slide parts are formed on the outside of the slide member at a predetermined distance from each other to reduce the contact area between the slide hole of the valve seat and the slide member. , it is proposed to reduce the frictional resistance during the reciprocating operation of the on-off valve.

[Problems to be solved by the invention] However, according to the structure of the above-mentioned proposal, fuel accumulates in the empty space between both sliding parts of the sliding member, causing a kind of damper action, which prevents opening and closing. Responsiveness of valve operation is impaired. Furthermore, if the stagnant fuel changes in quality, it is predicted that the operation of the on-off valve will be impaired and the metering accuracy will be reduced.

Therefore, the present invention was devised to solve the above-mentioned problems, and its purpose is to provide an electromagnetic fuel injector that can improve the responsiveness of the opening/closing valve operation and the metering accuracy. be.

[Means for Solving the Problems] The electromagnetic fuel injector of the present invention that solves the above problems includes: A conical valve seat portion having a fuel injection hole at the front end, in the front part of the cylindrical slide hole in the valve seat. are arranged in series, an on-off valve having a valve at the front end of a cylindrical slide member is inserted into the slide hole so as to be able to reciprocate in the axial direction thereof, and the cylindrical hollow part of the slide member is used as a fuel passage. A communication hole is provided at the front end of the sliding member to communicate between the inside and outside of the slide member, and the opening/closing valve is reciprocated by electromagnetic force and the spring force of a spring, and the valve element is detached from and brought into contact with the valve seat. An electromagnetic fuel injector that intermittently injects pressurized fuel from a fuel passage of a slide member through a circulation hole and from a fuel injection hole of the slide hole, the electromagnetic fuel injector having a fuel injection hole on the outside of the slide member and upstream of the circulation hole. By forming the front and rear slide parts at a predetermined distance from each other, a cavity is formed between the two slide parts, and a fuel hole is provided in the slide member between the two slide parts to communicate the inside and outside of the slide member. At least the front slide portion is provided with a notch that communicates the hollow portion with the outer communication portion of the communication hole.

[Function] According to the above means, the pressurized fuel flows from the fuel passage of the slide member through the circulation hole to the fuel injection hole of the slide hole, and at the same time flows from the fuel passage to the cavity through the fuel hole, and then flows to the front portion. The fuel flows into the fuel injection hole through the notch in the slide portion.

Therefore, the fuel in the space between the sliding parts of the sliding member actively flows to the fuel injection hole without being stagnated.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings. In FIG. 1, which is a sectional view of an electromagnetic fuel injector, a connector 5 having an input signal receiving section 1 is attached to the rear end (right end in the figure) of a cylindrical body 6. As shown in FIG. A substantially cylindrical fixed core 4 is provided from a substantially central portion of the body 6 to a rear end of the connector 5 . Fixed core 4
A strainer 19 is inserted into the rear end.

A bobbin 3 surrounding the fixed iron core 4 is provided in the rear part of the body 6. A coil 2 electrically connected to the input signal receiving section 1 is wound around the bobbin 3 .

A cylindrical valve seat 12 is inserted into the front portion of the body 6 . A conical valve seat portion 16 having a fuel injection hole 15 at the front end is connected to the front portion of the cylindrical slide hole 13 in the valve seat 12 . Note that a cylindrical adapter 20 is attached to the front end of the valve seat 12.

Opening/closing valve 11 disposed within the valve seat 12
has a spherical valve (also referred to as a spherical valve) 10 welded to the front end of a cylindrical slide member 9.
Note that a cross-sectional view of the on-off valve 11 is shown in FIG.

The slide member 9 is inserted into the slide hole 13 so as to be able to reciprocate in its axial direction. Further, the cylindrical hollow portion of the slide member 9 serves as a fuel passage 14. The front end of the slide member 9 is provided with a communication hole 21 that communicates the inside and outside of the slide member 9 (see FIG. 2).

A movable iron core 8 is attached to the rear end of the slide member 9. Note that the rear end surface of the movable iron core 8 is
It faces the front end surface of the fixed iron core 4.

A ring groove 9b is provided in the slide member 9 adjacent to the fixed iron core 8 (see FIG. 2). A stopper 17 is provided in this ring groove 9b. The stopper 17 is held between the body 6 and the valve seat 12.

A cylindrical spring receiving member 18 is inserted into the fixed core 4 . A spring 7 is provided between the opposing surfaces of the receiving member 18 and the slide member 9.
is mediated. This spring 7 always urges the on-off valve 11 in the closing direction.

Furthermore, as shown in FIG. 2, on the outside of the slide member 9, front and rear slide portions 9a are formed at a predetermined distance from each other on the upstream side of the communication hole 21. Both slide parts 9a
A cavity 22 is formed between them.

The slide member 9 is provided with a fuel hole 24 that communicates between the inside and outside of the slide member 9 between both slide portions 9a.

A notch 23 is provided on the outer circumferential surface of the front slide portion 9a located at the front portion of the slide member 9 (on the left side in the figure), which communicates the hollow portion 22 with the outer communication portion of the communication hole 21. There is. Notch 23
As shown in the cross-sectional view of FIG. 3, four pieces are formed at equal intervals, and the slide portion 9a is formed into a substantially rectangular shape. In this example, the rear slide portion 9
A notch 23 is also formed in a.

In the electromagnetic fuel injector described above, pressurized fuel is transferred from the rear end of the fixed core 4 to the strainer 1.
9 through the spring receiving member 18 and the on-off valve 11
The fuel flows into the slide hole 13 of the valve seat 12 from the fuel passage 14 and the communication hole 21 of the slide member 9 .

When the fuel injector is not operating (when the coil 2 is not energized), the spring force of the spring 7 causes the on-off valve 11 to be in the closed state, that is, the ball valve 10 is in contact with the valve seat portion 16 of the valve seat 12. As a result, fuel is not injected from the fuel injection hole 15.

In this state, when the coil 2 is energized,
The movable iron core 8 is attracted to the fixed iron core 4 against the spring force of the spring 7 due to the excitation effect generated in the coil 2, so that the on-off valve 111 is retracted. Along with this, the ball valve 10 is detached from the valve seat part 16 of the valve seat 12, so that the fuel injection hole 1
Fuel is injected from 5.

Furthermore, when the coil 2 is no longer energized, the on-off valve 11 is closed by the spring force of the spring 7, so that the injection of fuel from the fuel injection hole 15 is stopped.

Therefore, when the coil 2 is energized, the fuel hole 2
The fuel that has flowed into the hollow part 22 through the front sliding part 9a enters the fuel injection hole 15 through the notch 23 of the front slide part 9a.
flows to. Therefore, the fuel in the space 22 between the sliding portions 9a of the sliding member 9 actively flows into the fuel injection hole 15 without being retained.

Therefore, the damper action caused by the accumulation of fuel in the air member 22 during the reciprocating operation of the on-off valve 11 is eliminated, so that the responsiveness of the on-off valve 11 does not deteriorate.

Furthermore, the metering accuracy of the on-off valve 11 due to deterioration of the fuel in the air member 22 does not deteriorate.

Note that if the electromagnetic fuel injector is installed on the engine side with the adapter 20 side facing downward, the ball valve 1 of the on-off valve 11 will be damaged due to an increase in fuel temperature.
Remove the paper that accumulates around the front slide section 9a.
through the notch 23 of the hollow part 22, the fuel hole 24,
It can be discharged to the fuel passage 14. Therefore, it is possible to accurately measure the injected fuel even at high temperatures.

[Effects of the invention] According to the electromagnetic fuel injector of the invention, fuel can flow through the space between the sliding parts of the sliding member, so that the reciprocating movement of the on-off valve is smoothed.
Therefore, it is possible to prevent deterioration in the responsiveness of the opening/closing valve operation and the metering accuracy due to the accumulation of fuel.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a sectional view of an electromagnetic fuel injector, Fig. 2 is a sectional view of an on-off valve, and Fig. 3 is a sectional view taken along line A-A in Fig. 2. It is. 9...Slide member, 9a...Slide portion, 1
0...Ball valve, 11...Opening/closing valve, 12...Valve seat, 13...Slide hole, 14...Fuel passage, 15...Fuel injection hole, 16...Valve seat portion, 21
...Flow hole, 22...Empty part, 23...Notch,
24...Fuel hole.

Claims (1)

[Claim for Utility Model Registration] A conical valve seat portion having a fuel injection hole at the front end is connected to the front part of a cylindrical slide hole in the valve seat, and a valve seat is provided at the front end of the cylindrical slide member. An on-off valve having an on-off valve is inserted into the slide hole so as to be able to reciprocate in the axial direction thereof, the cylindrical hollow part of the slide member is used as a fuel passage, and the front end of the slide member is provided with a communication hole that communicates the inside and outside of the slide member. The on-off valve is reciprocated by an electromagnetic force and the spring force of a spring, and the valve element is detached from and brought into contact with the valve seat, thereby allowing pressurized fuel to flow from the fuel passage of the slide member through the flow hole of the slide hole. An electromagnetic fuel injector that intermittently injects fuel from a fuel injection hole, wherein front and rear slide parts are formed on the outside of a slide member at a predetermined interval from each other on the upstream side of the flow hole. a hollow part is formed between the two sliding parts, and a fuel hole is provided in the sliding member between the two sliding parts to communicate the inside and outside of the sliding member, and at least in the front sliding part, the hollow part and the fuel hole are provided between the sliding parts. An electromagnetic fuel injector characterized by having a notch that communicates with an outer communicating portion of a flow hole.