JPH0494448A - Fuel injection valve - Google Patents

Abstract

PURPOSE:To reduce a tapping noise at the time of operating a fuel injection valve with constitution left as conventional by combination-constituting a valve seat of a member of large internal loss and a member of high hardness. CONSTITUTION:When a fuel injection valve is in operation, a tapping noise is generated by a movable piece 7 always colliding against a valve seat 6. Especially a valve seat part 6 is exposed to the outside in an actual use condition, so that a problem is provided that the tapping noise is easily leaked to the outside. Then, for instance, a porous member of large internal loss is used for a material of the valve seat part 6, and hard plating is used for a valve seat surface part 6''. By the constitution thus obtained, vibration, generated when the movable piece 7 collides against the valve seat surface part 6'' at the time of operating the fuel injection valve, is efficiently converted into heat by the valve seat 6, so that noise volume, scattered to the outside, is reduced. Since hard plating is applied to the valve seat surface part 6'', seat characteristic with the movable piece 7 can be ensured equivalent to the conventional product.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a valve seat material for an electromagnetic fuel injection valve for an internal combustion engine and a surface treatment method thereof.

[Conventional technology]

In the conventional device, as described in Japanese Patent Application Laid-Open No. 60-60264, a fuel injection section was constructed of a ball valve at the tip of a movable element and a tapered valve seat.

[vlA problem that the invention seeks to solve]

The above-mentioned conventional technology takes into consideration the operating accuracy and durability of the movable element that reciprocates by electromagnetic force, but does not consider the operating noise of the movable element, especially the seat noise between the movable element and the valve seat. There was a problem in that seat noise was likely to occur when the fuel injection valve was activated.

An object of the present invention is to reduce the above-mentioned seat noise, and thereby to provide a highly quiet internal combustion engine.

[Means for Solving the Problems] In order to achieve the above object, the main material of the fuel injection valve seat is made of a material with large internal loss such as a sintered alloy,
The seat portion that the mover collides with is hard plated.

[Effect]

A member with large internal loss that occupies most of the valve seat portion efficiently converts vibration into heat or its own deformation. As a result, seat noise or vibration generated at the valve seat portion when the fuel injection valve is operated is attenuated within the member with a large internal loss, so that the sound volume radiated to the outside can be reduced.

On the other hand, since the valve seat seat surface is hard plated, it will not be deformed or worn out even if the movable member and the valve seat seat collide with each other when the fuel injection valve is operated.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is an enlarged view of the valve seat.

In Fig. 1, 1 is a solenoid coil, 62 is a return spring that is internally fixed inside the yoke of 3, and is installed between the stopper of 4 and the movable element of 7, and the movable element of 7 is attached to the valve seat of 6. Furthermore, the spring force generated by the spring 2, which acts to generate a pressing force, is adjusted to the optimum position for the electromagnetic attraction force of the solenoid coil 1 by a spring adjuster 5 whose position is adjustable and which is installed inside the stopper 4. Adjusted to provide spring force. The valve seat portion 6 is press-fitted or fixed by welding into the yoke 3.

When the fuel injection valve is operated, fuel passes through the gap between the yoke 3 and the mover 7 and accumulates under pressure in the space inside the valve seat 6. At this time, when the solenoid coil 1 is energized, the mover moves toward the stopper 4, and a small gap is created between the valve seat 6 and the mover 4. As a result, the pressurized fuel is discharged from the fuel discharge hole 6' provided in the valve seat 6. On the other hand, when the energization of the solenoid coil 1 is stopped, the movable element 4 collides with the valve seat 6 due to the force of the two springs, and the discharge of fuel is stopped. As described above, when the fuel injection valve is operated, the movable element 7 and the valve seat 6 constantly collide, resulting in a tapping sound.

In particular, since the valve seat section 6 is exposed to the outside during actual use, there is a problem in that the tapping sound is likely to leak outside. In the present invention, as shown in FIG. 2, the material of the valve seat 6 is, for example, a porous member with a large internal loss, and the surface of the valve seat 6' is hard plated. With this configuration, the valve seat 6 can efficiently convert the vibration generated by the collision between the valve seat surface section 6' and the mover 7 when the fuel injection valve is activated into heat, so that the vibration is not dissipated to the outside. Volume can be reduced. Since the surface of the valve seat 6' is hard plated, the seating properties with the movable member 7 can be secured to the same level as conventional products.

〔Effect of the invention〕

According to the present invention, without adding any special parts to the parts constituting the fuel injection valve, it is possible to reduce the hammering noise when the fuel injection valve is operated without adding any special parts to the parts constituting the fuel injection valve.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, and FIG. 2 is a detailed view of the valve seat portion and movable element colliding portion in FIG. 1. 1... Solenoid coil, 2... Return spring,
3...Yoke, 4...Stopper, 5...Spring adjuster, 6...Valve seat, 6'...Fuel discharge hole, 6#
... Valve seat surface part, 7... Mover. Figure 1

Claims (2)

[Claims] 1. An electromagnetic injection valve for supplying liquid fuel pressurized by a pressure pump to an intake cylinder of an internal combustion engine, wherein an electromagnetic coil and a fixed core are fixed inside a yoke that constitutes the electromagnetic injection valve body. At the same time, a movable element with a valve is biased toward the valve seat side by a return spring and built in, and the movable element is reciprocated by the electromagnetic attraction force when the electromagnetic coil is energized and the return spring force when the electromagnetic coil is not energized. What is claimed is: 1. A fuel injection valve that opens and closes the valve by movement, characterized in that the valve seat is made of a composite structure of a member with a large internal loss and a member with a high hardness. 2. 2. The fuel injection valve according to claim 1, wherein said member having a large internal loss is made of synthetic resin.