JP2523918Y2 - Fuel injection valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve used in a fuel injection device, and this fuel injection valve is an EC.
The fuel is injected based on the injection signal from the U, converting the electric signal into a fuel flow rate and atomizing and injecting the fuel.

[0002]

2. Description of the Related Art A conventional fuel injection valve is disclosed, for example, in Japanese Utility Model 4-8.
No. 308 publication. According to this, a fuel injection valve is provided in a cylindrical housing, a coil bobbin in which an electromagnetic coil is wound around the cylindrical housing, and a movable core which is disposed in an inner hole of the coil bobbin and is energized to the electromagnetic coil. And a valve seat formed body having a valve seat attached to the tip of the housing and opened and closed by a valve unit provided integrally with the movable core, and is energized to the electromagnetic coil. And a magnetic circuit formed by the housing, the fixed core, and the movable core. The magnetic force generated by the magnetic circuit causes the movable core to be attracted to the fixed core against the spring force of the spring. The fuel is injected toward the engine with the valve seat opened. On the other hand, when the power to the electromagnetic coil is cut off, the magnetic force disappears,
The valve portion closes the valve seat by the spring force of the spring, thereby suppressing fuel injection toward the engine. Then, in the electromagnetic coil, for example, a single enamel wire is wound.

[0003]

The electromagnetic coil using a single enameled wire has the following problems to be solved. The end of the electromagnetic coil is electrically connected to a power source by soldering to a terminal or the like or by mechanical caulking. And, when connecting to such a terminal or the like, when a single enamel wire is used, regarding the disconnection of the enamel wire because the wire diameter is relatively small,
Extreme care must be taken, and the connection work to the terminals, the connection state check work after connection, and the winding work around the coil bobbin require a lot of man-hours, which hinders productivity and increases manufacturing costs. Is not preferable.

Further, the coil resistance increases and the coil temperature rises. In particular, in a fuel injection valve in which fuel passes through the inside of the electromagnetic coil, the fuel temperature rise is made small and accurate fuel control is considered. Therefore, the selection of the coil diameter requires many development man-hours.

The fuel injection valve according to the present invention has been made in view of the above-mentioned problems, and provides an inexpensive fuel injection valve which is extremely easy to connect the electromagnetic coil to the terminals and to check the connection state. It is an object of the present invention to obtain a fuel injection valve in which the temperature rise is small and the selection of a coil is extremely easy.

[0006]

In order to achieve the above object, a fuel injection valve according to the present invention has a cylindrical housing; and an inner hole disposed in the housing and axially penetrating the center of the housing. A fixed bobbin having an electromagnetic coil wound around the outer periphery thereof; a fixed core disposed in an inner hole of the coil bobbin, having a through hole formed in the axial direction thereof, and magnetically coupled to the housing; A movable core having a valve at its tip; a valve seat which is opened and closed by the valve; and a fuel injection hole connected to the valve seat and opening outward. And a valve seat forming body attached to the tip of the housing, wherein a plurality of magnet wires are twisted into a single stranded wire, and the stranded wire is wound around the outer periphery of the coil bobbin as an electromagnetic coil. Was .

[0007]

By using a stranded wire for the electromagnetic coil, the risk of disconnection when connecting to a terminal or the like is greatly reduced, and the connection work is facilitated and the connection state check after connection is unnecessary. In addition, an increase in the resistance of the electromagnetic coil is suppressed, and a rise in the temperature of the electromagnetic coil can be suppressed.

[0008]

FIG. 1 shows an embodiment of a fuel injection valve according to the present invention. Reference numeral 1 denotes a bottomed cylindrical housing having a lower opening, and a fixed core 2 having a through hole 2A is integrally formed at the center of the housing. In this example, the through hole 2A penetrates downward from above, and fuel flows in from the upper through hole 2A. Reference numeral 3 denotes a coil bobbin made of a non-magnetic material and having an inner hole 3A passing through the center thereof, and an electromagnetic coil 4 connected to the terminal T is wound around the outer periphery. The coil bobbin 3 is inside the housing 1 and the inner hole 3A is inserted into the outer periphery of the fixed core 2. Numeral 5 is a valve seat forming body fixedly disposed in the opening of the housing 1. The valve seat forming body 5 has a valve seat 5A and a fuel injection hole 5B opening outward from the valve seat 5A. Is done. A movable core 6 that is allowed to move in the axial direction between the valve seat 5A of the valve seat forming body 5 and the lower end 2B of the fixed core 2 is disposed between the valve seat 5A and the lower end 2B of the fixed core 2. A valve portion 7 that contacts the valve seat 5A is formed at the tip, and the valve portion 7 is elastically urged to the valve seat 5A by a spring 8 together with the movable core 6 to close the valve seat 5A.

When the electromagnetic coil 4 is not energized, the valve portion 7 closes the valve seat 5A by the elastic force of the spring 8, and when the electromagnetic coil 4 is energized, the valve portion 7 is closed by the elastic force of the spring 8. Move upward to open the valve seat 5A,
The fuel supplied into the through hole 2A is injected and supplied from the valve seat 5A to the engine via the fuel injection hole 5B.

[0010] In the fuel injection valve according to the present invention, the electromagnetic coil 4 is formed by the stranded wire P. The stranded wire P is obtained by twisting a plurality of magnet wires such as an enameled polyester wire, and specific examples are shown in FIGS. The example of FIG. 2 is a five-ply collective twist, the example of FIG. 3 is a concentric twist of seven twists, and the example of FIG. 4 shows a composite twist of seven twists and further seven twists.

As described above, the stranded wire P
Is used, since it has flexibility compared to a single enameled wire, the coil breakage at the time of coil winding work on the coil bobbin 3 by the winding machine or connection work to the terminal T is eliminated. In addition, the efficiency of these operations can be improved, and the number of inspection steps after the operations can be greatly reduced, thereby achieving a significant reduction in manufacturing costs. In addition, the fact that the increase in the resistance can be reduced can suppress the rise in the temperature of the electromagnetic coil 4, and in particular, in the case of a fuel injection valve in which fuel flows inside the electromagnetic coil 4, the rise in the fuel temperature in the fuel injection valve can be suppressed. Therefore, it is possible to suppress the variation in the fuel injection amount due to the change in the viscosity of the fuel, and to provide a fuel injection valve having excellent fuel controllability.

[0012]

[Effects of the Invention] As described above, according to the fuel injection valve of the present invention, by using a stranded wire for the electromagnetic coil, the operation of winding the electromagnetic coil around the coil bobbin, the operation of connecting the electromagnetic coil to the terminal, In some cases, it is no longer necessary to consider the disconnection of the electromagnetic coil, thereby significantly improving the work efficiency. In addition, according to the above, it is possible to greatly reduce the checking work for disconnection of the electromagnetic coil, and it is possible to achieve an increase in the efficiency of the inspection work. Thus, the manufacturing cost can be reduced.
In addition, the fact that the temperature rise of the electromagnetic coil has been suppressed has enabled accurate control of the amount of fuel injected from the fuel injection valve.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a fuel injection valve according to the present invention.

FIG. 2 is a longitudinal sectional view showing one embodiment of a stranded wire used for the electromagnetic coil of the present invention.

FIG. 3 is a longitudinal sectional view showing another example of a stranded wire;

FIG. 4 is a longitudinal sectional view showing still another example of a stranded wire.

[Explanation of symbols]

 3 Coil bobbin 4 Electromagnetic coil P Stranded wire

Claims (1)

(57) [Scope of request for utility model registration] 1. A cylindrical housing; a coil bobbin provided in the housing, having an inner hole at the center thereof penetrating in the axial direction, and an electromagnetic coil wound around the outer periphery;
A fixed core disposed in the inner hole of the coil bobbin and having a through hole formed in the axial direction thereof and magnetically coupled to the housing; disposed opposite to the fixed core via a spring; A movable core provided with a valve seat; a valve seat formed at the front end of the housing, the valve seat being opened and closed by a valve portion, and a fuel injection hole connected to the valve seat and opened outward; A fuel injection valve comprising: a plurality of magnet wires twisted into a single stranded wire; and the stranded wire is wound as an electromagnetic coil around an outer periphery of a coil bobbin.