JPS61164457A - Electromagnetic actuator - Google Patents

Abstract

PURPOSE:To enable the high speed action of an armature to be performed, by arranging the armature forming concave sections and convex sections alternately in the circumferential direction, between two stators confronting each other and having exciting coils. CONSTITUTION:Stators 3, 4 of magnetic substance confronting each other are arranged in a housing 6. A plurality of concentric-circle-shaped concave sections 8 are formed on the margin sections of the stators 3, 4, and coils 9 are provided for the concave sections 8, and the adjacent coils are wound up mutually in the opposite directions. An armature 5 is arranged between the stators 3, 4. Concave sections and convex sections are alternately formed on the armature 5 in the circumferential direction, and a valve rod 10 is fixed and reciprocates between the stators 3, 4. When the coil 9 of the stator 3 or 4 is excited, the armature 5 is shifted at high speed in the direction as shown by the arrow head A or B in the figure. In this manner, a high speed actuator is organized and is suitable for a fuel injection valve.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to the structure of an electromagnetic actuator.

For example, it is used in electromagnetic valves of fuel injection devices.

(Conventional example) As this type of electromagnetic actuator, for example, JP-A-53
As shown in Publication No. 120017, an electromagnetic coil is provided in the stator, the armature is arranged to face the stator in a plane, and the armature is directed toward the stator by energizing the electromagnetic coil. Devices designed for suction are known. To return this armature to its original position, fluid pressure may be used as shown in the above publication, but normally a return spring is provided between the stator and armature, and the return force of this return spring is used to return the armature to its original position. That's what I'm supposed to do.

(Problems to be Solved by the Invention) As described above, in the conventional electromagnetic actuator, 1
Although this configuration has one stator for two armatures, in order to reciprocate the armature at higher speed, a second stator is placed on the return side of the armature, and the It would be easily conceivable to apply a restoring force to the armature by energizing the second electromagnetic coil.

However, since a large magnetic force is required to move the armature at high speed, the armature must be placed closely between both stators.

By arranging the armatures in close proximity in this way, if the armatures are simply made into a flat shape as shown in the above-mentioned publication, when the electromagnetic coil of one stator is excited, leakage magnetic flux will leak through the armature to the other stator. occurs and loses the effect of being placed in close proximity.

Therefore, it is conceivable to provide two armatures and place each armature close to the stator.

In Nil, the number of parts will increase and the price will rise.

Therefore, this invention uses a special armature shape to minimize the increase in the number of parts.

It is an object of the present invention to provide an electromagnetic actuator that can be operated at high speed.6 (Means for solving the problem) The gist of the present invention is to An armature is interposed between the two stators, and the armature is an electromagnetic actuator in which concave portions and convex portions are integrally formed alternately in the circumferential direction.

(Function) Therefore, one concave portion (or convex portion) is close to one stator and acts only on that stator, so leakage magnetic flux from one stator to the other stator is reduced, and - armature can be constructed, and the 11 problems mentioned above can be achieved.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, an electromagnetic actuator 1 constitutes an electromagnetic valve attached to a fuel injection device 2, and includes two stators 3 and 4 made of magnetic material and facing each other in a plane, and an electromagnetic actuator 1 that is made of a magnetic material and has two stators 3 and 4 facing each other in a plane. The stator 3 can be moved relative to each other.
, 4 and an armature 5 interposed between them.

The stators 3 and 4 have a housing 6 and a screw 7 on the outer peripheral surface.
The electromagnetic actuator 1 is housed within the housing 6. In the stators 3 and 4, for example, three grooves 8 are formed concentrically on the mutually facing planes 3a and 4a, respectively. A coil 9 is provided in each groove 8.
The adjacent winding directions of the coil 9 are opposite to each other, and the current direction is set to be opposite to each other. Therefore, magnetic fields in opposite directions are generated around the adjacent coils 9 and strengthen each other, so that the armature 5 is strongly attracted.

Further, a valve stem IO is fixed to the armature 5.

This valve rod 10 is slidably inserted into the fuel injection device 2 through a through hole 11 provided at the center of the stator 4, and a conical valve head 12 is attached to the lower end of the valve rod 10.
is formed, and this valve head 12 is seated on a valve seat 13 provided in the fuel injection device 2. And armature 5
is attracted to the stator 3, the valve head 12 is moved to the valve seat 1.
A fuel inlet passage 14 and a fuel outlet passage 15 formed in the fuel injection device 2 are connected to each other through a communication passage 16 formed in the fuel injection device 2, and the fuel pushed out by a plunger (not shown) is separated from the fuel injection device 2. is returned to the low pressure side.

The armature 5 has three parts as shown in FIG.
It has two concave portions 17 and three convex portions 18.

These concave portions 17 and convex portions 18 are integrally formed alternately in the circumferential direction. A boss portion 19 is formed in the center, and the armature 5 is configured. Further, the recessed portion 17 and the convex portion 18 are arranged in the radial direction so as to be located in the portion where the coils 9 of the stators 3 and 4 are buried.

In the axial direction, the stators 3 and 4 are separated by a distance slightly shorter than the distance between them. 6 However, in the above configuration, to explain the operation of the solenoid valve, the fuel inlet passage 1
4 and the fuel outlet passage 15, the coil 9 of the stator 4 is energized. The magnetic field caused by the excitation of the coil 9 acts on the recess 17 of the armature 5 and attracts the recess 17, so that the valve head 12 seats on the valve seat 13 and establishes communication between the inlet passage 14 and the outlet passage 15. Next, when the fuel inlet passage 14 and the fuel outlet passage 15 are to be communicated with each other, the coil 9 of the stator 3 is energized. The coil 9
As the convex portion 18 is attracted by the excitation, the valve head 12 is separated from the valve seat 13 and the inlet passage 14 and the outlet passage 15 are communicated with each other via the communication passage 16.

In this embodiment, three concave portions and three convex portions are provided, but it is needless to say that the present invention is not limited to this. Further, although the areas of the concave portions and the convex portions are all equal, the areas may be changed to vary the magnitude of the generated force.

(Effects of the invention) As described above, according to the invention, the armature in which the recesses and the projections are integrally formed alternately in the circumferential direction is interposed between two stators having excitation coils, so that the armature In the conventional example in which a return cut of return number 1 is used to return the spring to its original position, when the armature moves against the return force of the return spring, the The force is the generated electromagnetic force minus the return force of the return spring, whereas all the generated electromagnetic force acts as a force for moving the armature, moving one armature at high speed in two axial directions. It can be operated with. Furthermore, since the concave portion and convex portion are close only to the stator on the side to be attracted and are a predetermined distance in front of other stators, leakage occurs from one stator to the other stator via the armature. Magnetic flux decreases. Also.

Since only one armature is required, the number of parts per unit is small, and the assembly work can be simplified, thereby making it possible to reduce the cost.

By changing the area ratio of the concave portions or convex portions, the ratio of the generated force can be changed.

In addition, if electromagnetic force is used to move the armature in both the outward and return directions, the speed and generated force can be changed for each of the outward and return trips by controlling the applied voltage or current, improving the functionality of the solenoid valve. Therefore,
Tolerance can be added to the design of electromagnetic actuators.

Furthermore, since there is no need to generate electromagnetic force against the return spring, power consumption is reduced, and the heat dissipation area can be reduced, so the electromagnetic actuator can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a solenoid valve having an electromagnetic actuator according to the present invention, and FIG. 2 is a perspective view of the electromagnetic actuator used in the same. 1... Electromagnetic actuator, 2... Fuel injection device,
3, 4... Stator, 5... Armature, 17.
... Concave portion, 18... Convex portion. Figure 2 et al.

Claims (1)

[Claims] Two stators having excitation coils are arranged facing each other, and an armature is interposed between the two stators, and the armature is characterized in that recesses and projections are integrally formed alternately in the circumferential direction. electromagnetic actuator.