JPS6338369Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an improvement of an electromagnetic fuel injection valve used in an internal combustion engine.

Prior Art Among conventional electromagnetic fuel injection valves of this type, the bottom feed type has a plunger with a ball valve welded to its tip slidably inserted directly into the center hole of the valve seat. Because there was an excessive difference in hardness between the plunger and the valve seat, there was a problem in that the plunger was severely worn, causing the valve seat to lose its airtightness in a short period of time, resulting in poor durability. In addition, since the magnetic path section consisting of the plunger, core, and case is generally made of magnetic material,
When the electromagnetic coil is demagnetized, the plunger tends to stick to the magnetic path due to residual magnetism, resulting in a problem that the control accuracy of the fuel injection amount is low.

Purpose In view of the above problems, the present invention provides an electromagnetic fuel that maintains the airtightness of the valve seat over a long period of time and prevents the magnetic path section consisting of the plunger, core, and case from being attracted. The aim is to provide an injection valve.

Overview The electromagnetic fuel injection valve according to the present invention is characterized in that a guide member made of a non-magnetic material with hardness approximately equal to that of the plunger is interposed between the inner surface of the center hole of the valve seat and the plunger. be.

Embodiment Hereinafter, the present invention will be explained in detail based on an embodiment shown in FIGS. 1 and 2.
A generally cylindrical nozzle case 2 made of a magnetic material and having a fuel vapor outlet 1b and a fuel vapor outlet 1b is caulked to the upper end of the nozzle case 1, vertically penetrating the core part 2a provided at the lower end, and having a central A core made of a magnetic material having a fuel injection amount adjustment hole 2b concentric with the hole 1a, and a fuel vapor exhaust passage 2c communicating the hole 2b with the fuel vapor exhaust port 1b; 3 is a central large diameter portion of the core 2; An O-ring fitted to the outer periphery, 4 a coil bobbin fitted to the core part 2a, 5 an electromagnetic coil wound around the coil bobbin 4, and 6 a lower end of the electromagnetic coil 4
A terminal 8 is connected to the fuel injection amount adjusting hole 2b and has a chamfered portion 8a at the lower end, and has an O-ring 7 fitted in the center for airtightness. and a constricted part 8b that is continuous with the chamfered part 8a and faces the fuel vapor exhaust path 2c, and the upper small diameter part of the core 2 is narrowed at the upper end part, so that the core 2
9 is a ball plug press-fitted into the upper end of the fuel injection amount adjustment hole 2b; A center hole 10a which is caulked to the lower end of the nozzle case 1 and is concentric with the center hole 1a;
A pair of fuel inlet holes 1 formed in a spiral direction with respect to the center of the hole 1 and communicating the outer peripheral portion with the center hole 10a.
0b, 10b (see FIG. 2), an inverted conical sheet surface 10c concentric with the center hole 10a, and an orifice 10.
d; 12 is an O-ring fitted to the outer periphery of the lower end of the valve seat 10; 13 is a non-magnetic material which is fitted and fixed in both center holes 1a and 10a and whose hardness is approximately equal to that of the plunger described below. A pipe-shaped guide member made of body material, 14 is a guide member 13
A plunger made of a magnetic material and having a plurality of leg portions 14a formed at the lower end thereof and a center hole 14b continuous with the leg portions 14a and communicating with the hole 2b; A ball valve 15 is welded to the leg portion 14a and can come into contact with the seat surface 10c, and a ball valve 16 is interposed between the plunger 14 and the lower end surface of the rod 8 to give the plunger 14 a downward movement habit. The spring 17 is located between the lower end surface of the core portion 2a and the upper end surface of the plunger 14, and restricts the upward movement of the plunger 14 and the ball valve 15, and its thickness forms an air gap. A stopper 18 made of a non-magnetic material is attached to the nozzle case 1 and the valve seat 10 so as to surround the outer periphery corresponding to the fuel inlet holes 10b, 10b of the valve seat 10.
19 is a nozzle fitted to the lower end of the valve seat 10; 20 is interposed between the orifice 10d and the nozzle 19; A plurality of fuel passages 20a, . . . , 2 are formed.
It is a swirl plate with 0a.

Since the electromagnetic fuel injection valve according to the present invention is constructed as described above, when the electromagnetic coil 5 is energized by a signal from a control circuit (not shown), the plunger 14 and the ball valve 15 are drawn upward and opened. After the fuel passes through the filter 18, it flows into the center hole 10a through the fuel inlet holes 10b, 10b, and at this time, the fuel inlet holes 10b, 10b are formed in a spiral direction with respect to the center of the center hole 10a. Therefore, a swirl (eddy current) is generated within the center hole 10a. Next, the fuel passes through the orifice 10d and then flows through the fuel passages 20a,..., 20a.
The fuel is sprayed from the nozzle 19 through the swirl plate 2.
Since it is formed in a helical direction with respect to the zero axis, even more swirl occurs. The basic operation of the electromagnetic fuel injection valve according to the invention has been explained above.
Since the guide member 13, which has approximately the same hardness as the plunger 14, is interposed between the inner surface of the center hole 10a of 0 and the plunger 14, the wear of the plunger 14 is reduced and the airtightness of the valve seat 10 is maintained for a long period of time. It is maintained over a long period of time and its durability is improved.
Furthermore, since the guide member 13 is made of a non-magnetic material, the magnetic path section and the plunger 1 when the electromagnetic coil 5 is demagnetized are
4 is prevented, and the control accuracy of the fuel injection amount is improved. The fuel vapor generated in the center hole 10a is discharged between the legs 14a, between the center hole 14b, between the inner surface of the center hole 2b and the chamfered part 8a and the constricted part 8b, in the fuel vapor exhaust passage 2c, and at the fuel vapor exhaust port. 1b.

FIG. 3 is a diagram showing another mounting structure for the guide member 13, in which the guide member 13 is fitted into the center hole 1a of the nozzle case 1 and has an annular projection whose lower end is provided at the upper end of the valve seat 10. Article 10e
(concentric with the center hole 10a).

Effects of the Invention As described above, the electromagnetic fuel injection valve according to the present invention has the practically important advantages of improved durability and improved control accuracy of the fuel injection amount.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of one embodiment of the electromagnetic fuel injection valve according to the present invention, Fig. 2 is an enlarged sectional view showing the mounting structure of the guide member of the above embodiment, and Fig. 3 is another mounting structure of the guide member. FIG. 3 is an enlarged sectional view showing the structure. 1... Nozzle case, 2... Core, 3, 7, 1
2... O-ring, 4... Coil bobbin, 5... Electromagnetic coil, 6... Terminal, 8... Fuel injection amount adjustment rod, 9... Ball plug, 10... Valve seat, 11... Stroke adjustment shim, 13...
... Guide member, 14 ... Plunger, 15 ... Ball valve, 16 ... Spring, 17 ... Stopper, 18 ... Filter, 19 ... Nozzle, 20
...Swirl plate.

Claims (1)

[Scope of utility model registration request] In a bottom-feed type electromagnetic fuel injection valve in which a plunger with a ball valve welded to the tip is slidably inserted into the center hole of the valve seat, there is a hardness between the inner surface of the center hole of the valve seat and the plunger. An electromagnetic fuel injection valve characterized in that a guide member made of substantially the same non-magnetic material is interposed therebetween.