JPS58131353A - Electromagnetic fuel injector - Google Patents

Abstract

PURPOSE:To obtain an electromagnetic fuel injector which is excellent in its performance in spite of low manufacturing accuracy, by constituting a valve for opening and closing a fuel injection port from two spherical members having the same diameter, which is held in contact with an armature at one end and held in contact with a valve seat at the other end so that they function as a valve element. CONSTITUTION:A valve 31 is obtained by coupling two spherical members 32, 33 having the same radius by way of welding or other method and connecting further an armature 34 at one end of the members 32, 33 located on the axial line connecting the centers of the two spherical members, also by way of welding or other method. When the valve is closed, the spherical surface at the front part of the spherical member 32 is urged, by a spring 26, onto a conical valve seat 23a formed on the inside of an injection port 23 and serves as a valve element portion 32C for sealing high-pressure fuel. Since the valve element portion 32C is shaped to have a spherical surface, it has a self-aligning function.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic fuel injector mainly used in a multi-point or single-point electronically controlled fuel injection device for an internal combustion engine (hereinafter also referred to as engine) of an automobile.

Conventionally, an electromagnetic fuel injector 1 has a fuel injection port 5 at the tip of a pulp housing 2, as shown in FIG. , connect a chimney 1 to the rear end of the on-off valve 5, and attach a constant magnetic core 8 and an electromagnetic coil A/9 to the rear inside of the tsp ring 7 that holds the pulp housing 2;
A control signal is inputted from the terminal 10 force 4 to cause the on-off valve 5 to reciprocate and inject pressurized fuel.

The inner hook of the fuel injection port S of the pulp housing 20 forms a valve seat 5m (see wA in FIG. 2) that is tangential to the valve 5a of the on-off valve 50, and the fuel passage 4 continuing behind it has a cylindrical inner surface that is tangential to the valve 5a of the on-off valve 50. It serves as a guide hole for the valve 5. The details of the valve-head V fern 20 are protected by a cover 71, and the rear part is fixed to the front part of the magnetic housing 7 via an O-ring 11 on the @ face and a spacer 12 on the rear end face. A bottle 19 (see Fig. 2) is provided at the tip of the valve 5&, and an umbrella portion 19& for diffusing fuel is formed at the tip.

Seven flange 5b is provided on the rear circumference of the on-off valve 5 and contacts the front surface of the spacer 12 at the rear limit of the reciprocating stroke. The magnetic housing 7 is made of ferromagnetic material and has a nine-H shape, and an electromagnetic coil A/9 is attached to the space between it and the fixed magnetic core 8 via a sealing O-ring i5.1+. The fixed magnetic core 8 is made of a ferromagnetic material, and has a fuel passage 15 passing through its axial center. A compression spring 16 is inserted into the front end of the fuel passage 15, and constantly pushes the armchair 0vk end face forward to hold the on-off valve 5 in the closed position. A sleeve 17 serves as a fixed seat for the compression spring 16. A fuel filter 18 is provided at the rear end of the fuel passage 15.

In such an electromagnetic fuel injector 1#c, opening/closing 51?
5 moves smoothly, and the valve seat 51 is placed on the circular m-shaped valve seat 51.
It is necessary to seal the high-pressure fuel by making contact without any gaps.

For this reason, high machining accuracy is required for the nine sliding parts and the fuel passage clear guide hole 4 provided on the front and rear outer periphery of the on-off valve 5, and the valve seat 3a and valve element 5& are required to have surface roughness and perfect roundness. It is necessary to keep the degree and coaxiality within a very narrow range. Further, the tip shape of the on-off valve 5 including the bottle 19 and its bulk portion 19& must be formed into a complicated shape to atomize the fuel.
Moreover, the material of the guide hole 4 and the on-off valve 5 is rounded stainless steel, which is more difficult to process, and therefore the manufacturing cost thereof is extremely high.

In addition, since the on-off valve 5 of the conventional electromagnetic fuel injector 1 and the chi 1 chi air 10 are integrated and the weight is relatively heavy (approximately 5 f), the on-off valve 5 corresponding to the on/off of the electromagnetic coil I&/9 is relatively heavy (about 5 f).
The response is not very good, and the on-off valve 5 is worn and crystallized due to the large impact force. For rounding of 0 or more, which requires shortening the time it takes for the on-off valve 5 to stabilize when opening and closing the valve, reducing the mass of the on-off valve 5 and the armature 10 will have a great effect, but In order to maintain the accuracy of the parts, the diameter of the on-off valve 5 is made smaller (
This is not possible, and the on-off valve 5 can be rounded to avoid increasing the inclination of the axial center of the on-off valve 5 with respect to the axial center of the guide hole 4.
Therefore, it was not easy to realize an electromagnetic fuel injector with high responsiveness of the on-off valve 5 and excellent wear resistance.

In order to solve the problems mentioned above, this invention provides an electromagnetic fuel injector that has sufficiently high operating characteristics with moderate processing accuracy, and that also reduces the weight of the on-off valve and improves response characteristics. purpose.

The present invention will be explained below based on the drawings of the embodiment. In FIG. 5, 21 is an electromagnetic fuel injector according to the present invention. Reference numeral 22 denotes a pulp housing, which has a fuel injection port 25 at its tip and a guide hole 24 passing through the shaft center. Reference numeral 31 denotes a plunger type on-off valve, which is inserted into the guide hole 24 so as to be able to be excited, and has an armature 34 connected to its rear end. Fuel injection port 25 and guide hole 2
A fuel chamber 24& is provided between the fuel chamber 4 and the front end of the fuel chamber 24.

Magnetic housing 27, fixed magnetic core 2B, electromagnetic coil 29,
The terminal 50.0 ring 56, 57, 58 and the fuel filter 39 have the same structure as the conventional one. Between the rear end of the vap housing 22 and the front end of the fixed magnetic core 28,
Ah! A space is provided for the fx armature 34 to reciprocate, and the shoulder circumference of the armature 54 forms the fuel passage 27&.

A fuel passage 25 penetrates through the axial center of the #A constant magnetic core 28, and a pressure* and held in the closed position. 25 is a sleeve that forms a fixed seat for the compression spring 26.

The details of the on-off valve 31 are as shown in the fourth factor, in which two spheres 52 and 33 with the same radius are fixed W'Q by welding, etc., and an armature 34 is attached to one end on the axis connecting their centers, that is, the rear end of the sphere 330. It is a round piece that is joined by welding or other means. The large interior of each sphere 52.35 perpendicular to the axis of the on-off valve 51 is
A sliding portion 321°55* contacts the inner surface of the guide hole 24 and supports the on-off valve 51. These sliding parts 32m
, 351 are provided with at least two or more communication grooves 52b, 35b, which are arranged approximately equally on the circumference and cut out in the spherical surface to allow fuel to communicate. When the on-off valve 31 is in the closed position, the spherical surface of the front part of the sphere 52 is connected to the valve seat 23 provided on the conical cane inside the injection port 23.
& is pressed by a spring 261c to supply high pressure fuel to V
- It is a valve part 520 that rotates. Armature 34
The rear end surface is rounded and has a required thickness L to provide a certain gap between it and the front end surface of the fixed magnetic core 28 to the extent that it is not affected by the residual magnetism of the fixed magnetic core 28 when the on-off valve 31 is in the open position.
A spacer 55tl of a non-magnetic material having a bond is attached. When the on-off valve 51 is in the closed position, the distance between the rear end surface of the spacer 55 and the front end surface of the fixed magnetic core 28 is
Position so that the total stroke is D.

As described above, the on-off valve 31 having the structure in which two spheres with the same radius are fixed together can easily have a sliding portion 52 & 15 m of the diameter after 1 lti along the reciprocating axis, and this allows the on-off valve 51 to be Slide the guide [24Ic accurately and tighten the
This enables the formation of a jet stream. Well, since the nine-valve portion 52o has a # surface, it has a self-aligning function, and therefore it is possible to reduce the processing accuracy.

In contrast to the above configuration with two spheres, an on-off valve configured with one sphere may be considered from the viewpoints of reducing processing accuracy, automatic control, and weight reduction. In other words, there is no sliding part, and the sphere is fixed to a flat armature and held with a flexible holding material.
A spherical valve is pressed against or separated from a conical valve seat to open and close an injection port.

However, with this configuration, the operation of the flexible holding member is not sufficiently stable, and it is inferior to conventional on-off valves in terms of the flexibility of jet flow formation.

In addition, a configuration in which 5 or more spheres of the same shape are connected and fixed,
It is difficult to form straight lines of sliding parts at five or more locations, and requires very advanced processing technology, so there is no advantage.

In the electromagnetic fuel injector 21 configured as described above, pressurized fuel is sent through the fuel filter 59 and the fuel passage 2
5.27m, 24, communication groove for persimmon and on-off valve 51, 55b
, 52b and is supplied to the fuel chamber 24at. Since the on-off valve 31 is pressed by the compression spring 26, the fuel injection port 25 is always kept closed. From the control combinator (not shown) to the electromagnetic coil 29
When a valve opening time signal is input to the magnet, a magnetic field is generated in the magnetic housing 27 and the fixed magnetic core 28, the armature 54 is attracted, the on-off valve 31 integrated therewith retreats, and the valve seat 2
A gap is created between the valve part 5a and the valve part 52o, and the fuel 1if
24 m of pressurized fuel is injected from the fuel injection port 23.

When the on-off valve 31 is operated, even if there is a slight misalignment between the axes of the fuel injection port 23 and the guide hole 24, the abutment surface of the valve element 32o against the valve seat 23a is at the 9th spherical surface, and the compression spring 26Ic The contact surface of the valve element 52o moves due to the pressing force, and a restraining action is automatically activated, causing the valve seat 2! A perfect sealing action is performed between the ia and the valve part 32o by a circumferentially corresponding pressing force.

The weight of the on-off valve 31 including A1 f Responsiveness has been greatly improved.

In the fuel injection characteristics shown in Figure 5, the conventional characteristics (steel wire in the figure) (compared to the characteristics invented by Jin, as shown by sJ! As a result, the idling speed of the engine can be lowered, and the maximum speed can be increased to improve engine output.

As explained above, this invention utilizes advanced processing technology for an IIC magnetic fuel injector by connecting and fixing two spheres with the same radius and an armature on one axis to form an on-off valve with nine configurations. A sliding portion that enables smooth reciprocating motion without wobbling can be obtained without the need for this, and has the effect of making it possible to form a tight jet flow.

In addition, the spherical valve element provides a self-aligning function, which has the effect of making it possible to close the valve with ease while reducing machining accuracy.

The structure of the on-off valve is simplified and the weight thereof is reduced, which has the effect of increasing the responsiveness of the on-off valve and improving fuel injection characteristics. 'Furthermore, the processing accuracy is relaxed and the structure is simplified, which has the effect of reducing manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a conventional electromagnetic fuel injector, FIG. 2 is an enlarged explanatory view of the fuel injection port portion of FIG. 1, FIG. The figure is a detailed view of the on-off valve shown in Fig. 5, and Fig. 5 is an explanatory diagram of its operation. 2.22...Pulp housing 3.23...
・Fuel injection port 4.24...Guide hole 5.5
1... Open/close valve 52.55... Sphere 5
2m! i5m... Sliding parts 52b, 55b... Communication @ 6.34... Armchair applicant Aisan Kogyo Co., Ltd. Representative Patent attorney Oka 1) Hide
Hiko 13 WJ Shin 4 Figure IE 5 Figure M Minute II Pa (msec) Procedural amendment (Chikisui) Showa tj 1935 lie H Kazuo Kanwakasugi to the Patent Office 1 ・) IPl front page 1977 j 7 ++1. 'IOO1217)
o'i2, meeting, name of January, 7th - heavy tarka entertainment table ←1
1 sun week L3, relationship with 41Pl who makes Supplement 11 Patent applicant 4 Agent 6, number of inventions increased by Supplement 11 As stated below 7, amended oH state (1) 1ljllll book or patent claim 0 [LllJ
01l18, Contents of amendment (1) The statement in the "Claims" column of Specification O is amended as shown in the attached sheet. 2. What is claimed: A valve housing having a fuel injection port and a valve seat at the tip thereof and having nine guide holes penetrating through the shaft center, and a valve housing that is slidably inserted into the guide holes and is normally operated by a compression spring. An on-off valve that closes the injection port, an armature coupled to the rear end of this on-off valve, a fixed magnetic core having a front end face facing the rear end face of the armature with a fixed gap, and a periphery of this fixed magnetic core. An electromagnetic carp attached to
an internal combustion electromagnetic fuel injector that opens the on-off valve and injects pressurized fuel while the electromagnetic coil receives a valve opening signal; The on-off valve has two spheres of the same radius fixed together, one end of which is connected to the armature on an axis connecting their centers, and the other end is configured as a valve element that contacts the valve seat. Features an electromagnetic fuel injector.

Claims (1)

[Claims] A pulp housing with a fuel injection port and a valve seat at the tip and a good guide hole penetrating through the shaft center, and a pulp housing that is movably inserted into the guide hole and is always held by a compression spring.
When the fuel injection port is closed, the valve has an on-off valve, an armature connected to the rear end of the on-off valve, and a front end face that faces the rear end face of the armature with a certain gap between them. It consists of a fixed magnetic core having nine fuel passages penetrating through it, an electromagnetic coil attached around the fixed magnetic core, and a magnetic coil which connects the pulp/X-using and the fixed magnetic core, and the electromagnetic coil While receiving a valve opening signal at I&/, the fmm on/off valve opens and injects pressurized fuel.The on/off valve connects two female bodies with the same radius to t! ! 9. An electromagnetic fuel injector, characterized in that an armchair is connected to one end of the armchair connecting the centers of the two, and the other end is configured as a valve that twists into contact with the valve fiK.