JPH0237002Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a solenoid used in a solenoid valve.

[Prior Art] In a conventional solenoid for a solenoid valve, the generation of the attraction force that attracts and slides the movable core is limited to between the opposing magnetic pole faces of the fixed core and the movable core.

Therefore, when the solenoid is downsized, the area of opposing magnetic poles between the fixed core and the movable core also decreases, which inevitably reduces the force with which the fixed core attracts the movable core.

[Problems to be solved by the invention] The problem to be solved by the invention is to increase the suction force of the movable core with a simple configuration, thereby making it possible to further downsize the solenoid for a solenoid valve. This is a problem.

[Means for Solving the Problems] The present invention provides a fixed core at one end of a bobbin around which an excitation coil is wound, and a movable core is slidably disposed opposite to the fixed core. In a solenoid for a solenoid valve in which an excitation coil is surrounded by a magnetic frame, the inner surface of the center hole of the magnetic frame facing the movable core is formed by a tapered surface with a smaller diameter on the fixed core side, and the above-mentioned taper in the movable core is The above problem is solved by making the surface facing the fixed iron core a conical surface that comes into close contact with the tapered surface when it is attracted to the fixed iron core.

[Operation] In the electromagnetic valve solenoid having the above configuration, when the excitation coil is excited, an attractive force that attracts the movable core is generated between the opposing magnetic pole surfaces of the fixed core and the movable core, and the tapered surface of the magnetic frame Also, a suction force is generated that attracts the movable iron core.

The attractive force generated on the tapered surface of the magnetic frame is caused by the fact that the opposing surfaces of the magnetic frame and the movable core are inclined with respect to the sliding direction of the movable core, which attracts the movable core in the sliding direction. Therefore, the movable core is attracted by a large attraction force that is the addition of the sliding direction component of the attraction force of the magnetic frame to the attraction force of the fixed core.

[Embodiment] Fig. 1 shows an embodiment of the present invention, in which an excitation coil 1
A fixed iron core 3 is fitted and fixed into one end of the center hole of the bobbin 2 wound with a movable iron core 4, and a movable iron core 4 is slidably disposed opposite to the fixed iron core 3. The magnetic frame 5 surrounding the excitation coil 1 is
Magnetic frame body 6 that covers the top surface and outer peripheral surface of the excitation coil 1
and an annular magnetic plate 7 connected thereto and having a center hole facing the movable iron core 4. At the periphery of the center hole of the magnetic plate 7, there is a cylindrical portion 8 projecting to both sides in the axial direction of the hole. The magnetic plate 7 is positioned concentrically with the bobbin 2 by fitting one end of the cylindrical portion 8 into a stepped portion formed in the center hole of the bobbin 2.

On the other hand, the movable core 4 slidably inserted into the center hole of the bobbin 2 and the magnetic plate 7 is provided with a valve member 9 that closes a valve seat, which will be described later. Spring 1 interposed between iron core 4
0, the valve seat is always biased in the direction of closing.

The inner surface of the center hole of the magnetic plate 7 is formed by a tapered surface 11 with a smaller diameter on the side of the fixed core 3, and the surface of the movable core 4 facing the tapered surface 11 is spaced apart from this by a gap x. The fixed iron core 3 side is formed into a conical surface 12 with a smaller diameter.

As shown in FIG. 2, the above-mentioned gap x has a relationship of x=lsinθ with respect to the stroke l of the movable iron core 4, where θ is the inclination angle of the tapered surface 11 and the conical surface 12, and therefore the movable When the iron core 4 is attracted to the fixed iron core 3, the conical surface 12 comes into close contact with the tapered surface 11 thereof.

Note that the arrows in FIG. 2 indicate the flow of magnetic flux near the gap x.

The above-mentioned excitation coil 1, bobbin 2, fixed iron core 3,
A solenoid composed of a movable core 4, a magnetic frame 5, etc. has a valve seat 2 that is opened and closed by a valve member 9.
1 is joined to the valve body 20 provided with the valve body 20. This valve body 20 has an inflow passage 22 and an outflow passage 23 formed therein, and a valve chamber 24 facing the above-mentioned solenoid. The passages 23 communicate with valve chambers 24, respectively. The valve body 20 is positioned relative to the solenoid by inserting the cylindrical portion 8 of the magnetic plate 7 into the valve chamber 24, and is integrated with the solenoid by appropriate means.

Note that the inner surface of the center hole of the magnetic plate 7 or the movable iron core 4
By applying a wear-resistant, non-magnetic or weakly magnetic plating or coating treatment to one or both of the conical surfaces of the conical surface, wear of both can be prevented.

In the solenoid having the above configuration, when the excitation coil 1 is excited by a conductive wire (not shown), the fixed core 3 attracts the movable core 4 by the attractive force generated between the opposing magnetic pole faces of the movable core 4. The suction is similar to the conventional solenoid, but the magnetic plate 7 has a tapered surface 11 and the movable iron core 4 has a conical surface 1.
2, due to the attractive force Fx of the magnetic plate 7, Fa=Fxsinθ, as shown in FIG.
A component force Fa in the sliding direction is generated with the relationship:

Therefore, the sliding direction component force Fa of the attractive force generated between the opposing magnetic pole surfaces of the magnetic plate 7 and the movable iron core 4 is added to the conventional attractive force that occurs between the opposing magnetic pole surfaces of the fixed iron core 3 and the movable iron core 4. As a result, the movable iron core 4 is attracted by a large suction force. In addition, this sliding direction component force
The radial component force Fb of the movable iron core is reduced by Fa.

[Effects of the invention] In the present invention, the center hole of the magnetic frame is made into a tapered surface, and the surface of the movable core opposite to this is made into a conical surface. The sliding direction component of the attraction force generated between them is added to the attraction force of the fixed core, and the movable core is attracted with a large attraction force. Also, the desired suction force can be obtained and the solenoid can be made smaller.

In addition, the generation of the sliding direction component force reduces the radial component force on the movable core, which prevents the movable core from being attracted to either side and sliding eccentrically. The operation becomes smoother and the life of the solenoid can be improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the main part, and FIG. 3 is an explanatory diagram of the attractive force generated in the magnetic frame. 1... Excitation coil, 2... Bobbin, 3... Fixed iron core, 4... Movable iron core, 5... Magnetic frame, 11...
Tapered surface, 12...conical surface.

Claims (1)

[Scope of utility model registration request] A solenoid for a solenoid valve comprising a fixed iron core provided at one end of a bobbin around which an excitation coil is wound, a movable iron core slidably disposed opposite to the fixed iron core, and the excitation coil surrounded by a magnetic frame. The inner surface of the center hole of the magnetic frame facing the movable core is formed by a tapered surface with a smaller diameter on the fixed core side, and the surface of the movable core facing the tapered surface is formed so that the inner surface of the center hole faces the movable core when the movable core is attracted to the fixed core. A solenoid for a solenoid valve characterized by a conical surface that closely fits into a tapered surface.