JPH0674357A - Solenoid valve - Google Patents

Abstract

PURPOSE:To facilitate mounting and fixing a covering member relating to a movable core by forming the covering member from a heatshrinkage tube, in a solenoid valve of providing the covering member in the periphery of the movable core magnetically attracted at the time of electrifying a solenoid coil. CONSTITUTION:In a solenoid coil, a movable core 9 is attracted to a side of a fixed core 4 against a spring 11 by energizing the fixed core 4 at the time of electrifying a solenoid coil 3 wound onto a bobbin 2. As a result, a valve part 8 integrally formed with the movable core 9 is separated from a hole 7A of a valve seat 7, to flow control fluid from a flow path 5 to a flow path 6. Here for ensuring the movable core 9 to smoothly slide in the bobbin 2, a covering member 12, formed of a plastic-made tube heat shrinking further with a very small coefficient of friction, is mounted on the periphery of the movable core 9. The sovering member 12 is mounted by its heat shrinkage after coating the periphery of the movable core 9 with the covering material 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case, a fixed iron core excited by energization of a solenoid coil, a movable iron core attracted to the fixed iron core by the excitation of the fixed iron core, and the movable iron core attached to the valve seat side. A solenoid valve comprising a biasing spring.

[0002]

2. Description of the Prior Art FIGS.
It is sectional drawing which shows an example of the conventional electromagnetic valve disclosed by the 324 publication. In the figure, reference numeral 1 is a case, 2 is a bobbin made of plastic contained in the case 1, and 3 is a bobbin 2.
A solenoid coil, 4 wound around a fixed core, which is built in the bobbin 2 and is excited by energization of the solenoid coil 3, 5 and 6 are flow passages for a control fluid such as oil, and 7 is an outlet of the flow passage 5. A valve seat provided, 8 is a valve portion that closes the hole 7a of the valve seat 7, 9 has a valve portion 8 at the tip, and is incorporated in the bobbin 2 so as to be freely slidable in the axial direction. The movable iron core 10 is a plastic covering member attached to the outer periphery of the movable iron core 9 so that the movable iron core 9 can slide smoothly, and the reference numeral 11 is provided between the fixed iron core 4 and the movable iron core 9. It is a spring that is contracted and biases the valve portion 8 via the movable iron core 9 so as to close the hole 7a of the valve seat 7.

In such a structure, when a current is passed through the solenoid coil 3, the fixed iron core 4 is excited, so that the movable iron core 9 resists the urging force of the spring 11 and the fixed iron core 4 moves.
Is sucked to the side. As a result, the valve portion 8 closing the hole 7a of the valve seat 7 is separated from the hole 7a of the valve seat 7, so that the control fluid flows from the flow path 5 to the flow path 6.

At this time, the movable iron core 9 smoothly slides in the bobbin 2 toward the fixed iron core 4 side via the covering member 10 mounted on the outer periphery.

[0005]

Since the conventional solenoid valve is constructed as described above and the covering member 10 is attached to the outer periphery of the movable iron core 9 by a fitting method, the covering member 10 can be mounted and fixed extremely. It is troublesome, and since the covering member 10 needs to be manufactured together with the movable iron core 9, there is a problem that cost increase cannot be avoided. Further, since the covering member 10 is manufactured by molding or cutting, there are problems that it is difficult to reduce the thickness and the material is easily wasted.

The present invention has been made in order to solve the above problems, and enables the mounting and fixing of the covering member to be performed easily and reliably, and the covering member to be easily manufactured. The purpose of the present invention is to provide a solenoid valve.

[0007]

In the solenoid valve according to the present invention, a covering member made of a heat-shrinkable tube is attached to the outer periphery of the movable iron core.

[0008]

In the solenoid valve according to the present invention, since the covering member mounted on the outer periphery of the movable iron core is formed of the heat-shrinkable tube, the manufacturing and mounting of the covering member can be performed easily and reliably. In addition, the movable iron core can be smoothly slid, and the solenoid valve can be stably slid.

[0009]

【Example】

Example 1. FIG. 1 is a sectional view showing an embodiment of a solenoid valve according to the present invention. In the figure, the same parts as those of the conventional example and the corresponding parts are designated by the same reference numerals, and the description thereof will be omitted. Reference numeral 12 is a covering member mounted on the outer periphery of the movable iron core 9 so that the movable iron core 9 can smoothly slide in the bobbin 2, and 13 is a magnetic path holder made of a magnetic material having a magnetic circuit function.

The covering member 12 is placed on the outer periphery of the movable iron core 9 and is attached to the surface of the movable iron core 9 in close contact with the movable iron core 9 by thermal contraction. Further, the covering member 12 is
It is made of a plastic tube (for example, fluororesin) having an extremely small friction coefficient.

In such a structure, when a current is passed through the solenoid coil 3, the fixed iron core 4 is excited, so that the movable iron core 9 resists the urging force of the spring 11 and the fixed iron core 4 moves.
Is sucked to the side. As a result, the valve portion 8 pressed against the hole 7a of the valve seat 7 is replaced by the hole 7 of the valve seat 7.
Since it is separated from a, the control fluid flows from the flow path 5 to the flow path 6. At this time, the movable iron core 9 smoothly slides in the magnetic path holder 13 toward the fixed iron core 4 side via the covering member 12 mounted on the outer periphery.

Example 2. FIG. 2 is a cross-sectional view showing another embodiment of the solenoid valve according to the present invention. In the figure, the same parts as those of the first embodiment and the corresponding parts are designated by the same reference numerals,
The description is omitted. In the figure, reference numeral 9a denotes a stepped portion provided on the peripheral edge portion on the upper end side of the movable iron core 9 for preventing the covering member 12 from coming off, and 12a adjusts the flow direction of the control fluid flowing out from the hole 7a of the valve seat 7. It is a hanging piece.

The step portion 9a is formed continuously in the circumferential direction of the movable iron core 9, and the upper end portion of the covering member 12 is thermally contracted and adheres to the step portion 9a. Further, the lower end of the covering member 12 is formed to be slightly longer, and is heat-shrinked and closely adhered to the lower end side peripheral edge 9b of the movable iron core 9 so as to wrap the peripheral edge 9b. The hanging piece 12a is provided obliquely on the hole 7a side of the valve seat 7.

According to this embodiment, there is an effect that the covering member 12 can be securely fixed to the outer circumference of the movable iron core 9. In this case, the covering member 12 can be fixed to the movable iron core 9 only by fixing one of the upper and lower ends of the covering member 12 to the movable iron core 9, but if both ends of the covering member 12 are fixed as in the embodiment,
Furthermore, it can be securely fixed. Also, the hanging piece 1
Contamination (impurities and foreign substances) in the control fluid due to 2a
Is less likely to enter the clearance between the movable iron core 9 and the magnetic path holder 13 and has the effect of preventing the accumulation of contaminants.

[0015]

As described above, according to the present invention,
Since the covering member made of a heat-shrinkable tube is attached to the outer periphery of the movable core, the heat-shrinkable tube as the covering member is inserted into the movable iron core, and heat is applied to shrink the covering member so that the covering member can be easily attached to the movable iron core. It has the effect of being attached and fixed to.

Further, the covering member can be manufactured easily and at low cost, and can be mounted on a movable iron core of any shape and size, so that the versatility is high.
Further, since the covering member can be made relatively thin, it is almost unnecessary to consider the change in wall thickness due to the temperature change. Therefore, the clearance between the support and the movable iron core can be kept almost constant, and the movable iron core can be heated from low temperature to high temperature. There is also an effect that it can be operated stably at all times.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a solenoid valve according to the present invention.

FIG. 2 is a sectional view of another embodiment of the solenoid valve according to the present invention.

FIG. 3 is a cross-sectional view of a conventional example of a solenoid valve.

FIG. 4 is a cross-sectional view of a conventional example of a movable iron core to which a covering member is attached.

FIG. 5 is a cross-sectional view of another conventional example of a movable iron core to which a covering member is attached.

[Explanation of symbols]

 1 Case 2 Bobbin 3 Solenoid Coil 4 Fixed Iron Core 5 Control Fluid Flow Path 6 Control Fluid Flow Path 7 Valve Seat 9 Movable Iron Core 10 Covering Member 11 Spring

Claims (1)

[Claims] 1. A case, a bobbin built in the case, a solenoid coil wound around the bobbin, a fixed iron core built in the bobbin and excited by energization of the solenoid coil, A movable iron core that is built in the bobbin and that is attracted to the fixed iron core by excitation of the fixed iron core, and is contracted between the fixed iron core and the movable iron core, and urges the movable iron core toward the valve seat side. A solenoid valve comprising a spring, wherein a coating member made of a heat-shrinkable tube is attached to the outer periphery of the movable iron core.