JPH04365305A - Stator for solenoid - Google Patents

Abstract

PURPOSE:To provide a stator for solenoid, which can be manufactured easily. CONSTITUTION:A three way control valve is provided in a fuel injection valve for diesel engine, and a stator 26 for solenoid is provided in the three way control valve. The stator 26 for solenoid comprises a plurality of plates made of a magnetic material, and the plates made of the magnetic material have an identical thickness with each other, and they have bent shapes. Further, the stator 26 for solenoid is formed by laying the plates made of the magnetic material in the form of a spiral around the center axis of the stator.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator for a solenoid used, for example, in a solenoid valve.

0002

2. Description of the Related Art Hitherto, a stator for a solenoid of an electromagnetic valve is known, as disclosed in Japanese Patent Application Laid-Open No. 63-203981. This involves preparing a large number of wedge-shaped magnetic plates (laminates) as shown in Figure 5, and arranging them radially from the center of the stator to form a cylindrical stator, as shown in Figure 6. be. At this time, when processing the magnetic plate material into a wedge shape, cutting methods, pressing methods, drawing methods, sintering methods, etc. can be used.

0003

[Problems to be Solved by the Invention] However, when using the drawing method to form a magnetic plate into a wedge shape, there are problems with processing limitations and dimensional accuracy with the current technology, and when using the sintering method, the solenoid valve When a large amount of attraction force is required, the attraction force is greatly reduced compared to the cutting method because the maximum magnetic flux density is low. Furthermore, if the cutting method is used, the cost will be extremely high if the number of magnetic plates is large.

An object of the present invention is to provide a stator for a solenoid that is easy to manufacture.

[0005]

[Means for Solving the Problems] The present invention provides a stator for a solenoid in which a plurality of magnetic plates having a uniform thickness and a curved shape are arranged in a spiral shape with respect to the central axis of the stator. That is.

[0006]

[Operation] A magnetic plate having a uniform thickness and a curved shape is manufactured by pressing a flat magnetic plate. That is, the stator for a solenoid can be manufactured without using the conventional cutting method, pressing method, drawing method, or sintering method for forming a wedge shape.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to the drawings. FIG. 1 shows a fuel injection valve provided in each combustion chamber of each cylinder of a diesel engine. This fuel injection valve uses the solenoid stator 26 of the present invention.

In FIG. 1, a lower casing member 1 consists of a body lower 2, a connecting member 3, and a valve casing 4, and each member 2, 3, 4 is integrated by a retaining ring 5. Inside the valve casing 4 is a valve body sliding hole 6.
A fuel reservoir chamber 7 is formed, and a nozzle hole 8 communicating with the fuel reservoir chamber 7 is formed at the tip. A large diameter portion 10 of a nozzle needle 9 is slidably fitted into the valve body sliding hole 6 . A connecting portion 11 is formed on the large diameter portion 10 of the nozzle needle 9, and a small diameter portion 12 and a valve body portion 13 are integrally formed on the lower tip portion. The seat portion x is opened and closed by the valve body portion 13, and fuel is injected from the nozzle hole 8.

At the tip of the connecting portion 11 of the nozzle needle 9, a flange 14, a piston pin 15 and a piston 1 are provided.
6 are integrally connected. Further, the nozzle needle 9 is urged in the valve closing direction by a spring 17. The piston 16 is slidably fitted into a cylinder 18 formed in the lower body 2, and a pressure control chamber 19 is formed within the cylinder 18 from which the end of the piston 16 is exposed.

A plate valve 20 having an orifice is provided in the upper part of the pressure control chamber 19, and a spring 21 for pressing the plate valve 20 is provided. An upper casing member 23 having a three-way control valve (electromagnetic valve) 22 is closely connected to the body lower 2 . That is, the cylindrical body upper 24 is screwed onto the body lower 2,
A three-way valve body 25 and a solenoid stator 26 are arranged in the inner hole of the body upper 24.

As shown in FIG. 1, the solenoid stator 26 has a cylindrical shape and has an annular coil insertion groove 38 formed in its lower surface. This solenoid stator 26 includes a number of magnetic plates 3 having a curved shape as shown in FIG.
It consists of 6. A grain-oriented silicon steel plate with good soft magnetic properties is used for the magnetic plate 36, and the plate thickness is uniform. This magnetic plate 36 is formed into a curved shape by stamping and punching a flat silicon steel plate, and has a cutout recess 37 that becomes a coil insertion groove 38 . Then, as shown in FIG. 4, this plate 36 is arranged in a spiral shape with respect to the central axis of the stator using a jig or the like, and the outer periphery is welded using a laser or the like, so that the cylindrical solenoid shown in FIG. Stator 26 is manufactured. Note that the magnetic plate 36 may be a non-oriented silicon steel plate.

Further, in FIG. 3, the three-way valve body 25
An outer valve 27 is slidably fitted therein, and an inner valve 28 is disposed in the inner hole of the outer valve 27. When the coil 29 is demagnetized, the outer valve 27 is in the lower position due to the force of the spring 30, and the high pressure side passage 31 and the pressure control chamber 19 are communicated via the oil passage 32. Further, when the coil 29 is excited, the outer valve 27 moves upward, and the pressure control chamber 19 and the drain passage (low pressure side passage) 33 are communicated via the oil passage 32. A fuel supply passage 34 is formed in the lower casing member 1, one end of which is exposed on the surface of the casing member 1, the other end communicates with the fuel reservoir chamber 7, and is connected to the high pressure side of the upper casing member 23. aisle 3
1 is connected. Further, an inlet 35 is screwed into the surface of the casing member 1 at the bottom thereof, and communicates with the fuel supply passage 34 .

High-pressure fuel from the common rail (high-pressure fuel accumulator pipe) is supplied to the fuel reservoir chamber 7 through the inlet 35 and the fuel supply passage 34, and is also supplied to the three-way control valve 22. Further, the fuel in the drain passage 33 can be drained into a drain tank. Therefore, when high-pressure fuel is supplied to the pressure control chamber 19, the force applied from the piston 16 in the valve closing direction to the nozzle needle 9 in response to this pressure is the force applied in the valve opening direction due to the pressure in the fuel reservoir chamber 7. The nozzle needle 9 closes the nozzle hole 8 by exceeding . From this state, the pressure control chamber 19 in which the three-way control valve 22 is controlled communicates with the drain passage 33 on the low pressure side, and the fuel in the pressure control chamber 19 flows out to the low pressure side, causing the nozzle needle 9 to move in the valve opening direction. Then, fuel is injected.

As described above, in the solenoid stator 26 of this embodiment, a plurality of magnetic plates 36 having a uniform thickness and a curved shape are arranged in a spiral shape with respect to the central axis of the stator 26. Therefore, the magnetic plate 36, which has a uniform thickness and a curved shape, is manufactured by pressing a flat magnetic plate, and does not require conventional cutting or pressing methods to form a wedge shape. A stator for a solenoid is manufactured without using a drawing method or a sintering method. As a result, it can be easily manufactured using current technology by press stamping. Furthermore, since a oriented (or non-oriented) silicon steel plate with good soft magnetic properties and other magnetic materials can be used, the maximum magnetic flux density can be high and the attractive force can be strong. In addition, eddy current flowing through the stator 26 can be reduced, and high-speed response of the solenoid valve can be achieved.

[0015]

[Effects of the Invention] As detailed above, the present invention exhibits the excellent effect of providing a stator for a solenoid that is easy to manufacture.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a stator for a solenoid according to an embodiment.

FIG. 2 is a perspective view showing a magnetic plate in the solenoid stator of the embodiment.

FIG. 3 is a sectional view showing a fuel injection valve.

FIG. 4 is a diagram showing a stator for a solenoid.

FIG. 5 is a perspective view showing a magnetic plate in a conventional stator for a solenoid.

FIG. 6 is a perspective view of a conventional stator for a solenoid.

[Explanation of symbols]

26 Stator for solenoid 36 Magnetic plate

Claims (1)

[Claims] 1. A stator for a solenoid, characterized in that a plurality of magnetic plates having a uniform thickness and a curved shape are arranged in a spiral shape with respect to the central axis of the stator.