JPH1140418A - Solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration and damage of a bobbin by avoiding direct application of an impactive force of a movable core to the bobbin. SOLUTION: A bobbin 52 has a closed-end tube 52a. A first through hole 52c is formed in a bottom wall 52b of the closed-end tube 52a along a virtual axis L of a movable core 32. A case 53 has a bottom wall 53a opposed to the bottom wall 52b and is mounted on a valve body 7 by fixing metal parts 8 with the bobbin 52 accommodated inside. A second through hole 53b having a female thread is formed along the virtual axis L of the first through hole 52c. A stopper member 54 is provided with a friction part 54a which rubs against the first through hole 52c, a protrusion 54b protruding toward the inside of the closed-end tube 52a, a male thread for engagement in the female thread of the second through hole 53b and a head 54d which can be rotated from outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid which is mounted on a valve body and forms an electromagnetic valve together with the valve body.

[0002]

2. Description of the Related Art In general, an electromagnetic valve, which is a component of a hydraulic circuit or the like, includes a pair of left and right solenoids (electromagnets) having the same structure for operating the spool provided on a valve body having a built-in spool for opening and closing an oil passage and the like. ).

FIG. 2 shows a sectional view of a conventional example of one of a pair of left and right solenoids of this kind.

A solenoid 1 shown in FIG. 2 is a solenoid widely used for an oil immersion type solenoid valve and the like. The solenoid 1 includes a coil assembly 2, a tube assembly 3, and a nut 4.

The coil assembly 2 includes a resin bobbin 21
And a solenoid coil 22 wound around the bobbin 21
And a plurality of donut-shaped yokes 23 forming a part of the magnetic circuit MC indicated by the dashed arrows when the solenoid coil 22 is excited, and a hollow cylindrical magnetic body also forming a part of the magnetic circuit MC 24 and the solenoid coil 22
Terminal pin 25 for taking in current from outside
By setting these components 21 to 25 in a mold and injecting a resin material, the components 21 to 25 are molded and integrally formed in the resin case 26.

The tube assembly 3 is a coil assembly 2
Is inserted into the hollow portion of the bobbin 21. The tube assembly 3 includes a fixed iron core 31 having a male screw 31 a screwed into a female screw formed on a valve body (not shown), a movable iron core (plunger) 32 receiving a magnetic attraction force from the fixed iron core 31 when the solenoid coil 22 is excited, One end is welded to the fixed iron core 31 and the other end is welded to the stopper 34. The pipe 33 is made of a non-magnetic material and accommodates the movable iron core 32 slidably in the axial direction. And is integrally formed with the stopper 34. A manual operation pin 39 is slidably inserted into the through hole of the stopper 34 while ensuring sealing properties. The manual operation pin 39 is for manually operating a spool (not shown) in the valve body via the movable iron core 32 and the push pin 35 by an operation from the outside.

The nut 4 is a nut that is screwed into the external thread 34a of the stopper 34 of the tube assembly 3.
It is used to integrate the tube assembly 3 and the coil assembly 2 into a valve body. That is, the method of mounting the solenoid on the valve body is as follows. The male screw 31a of the fixed iron core 31 of the tube assembly 3 is screwed into the female screw of the valve body, and the coil assembly 2 is assembled to the tube assembly 3. The nut 4 is screwed into the male screw 34a.

The lower end surface of the movable iron core 32 is in contact with the upper end surface of a push pin 35.
5 is in contact with a spool (not shown) of the valve body through a through hole 31b in the vertical direction of the fixed iron core 31. Further, when the solenoid coil 22 is demagnetized and the other solenoid (which is located on the opposite side to the solenoid shown in FIG. 2 across the valve body and has the same structure as the solenoid shown in FIG. 2) is energized, the spool (Not shown) pushes the push pin 35 against the elastic force of a spring (not shown), and the movable core 32 is separated from the fixed core 31.

[0009]

However, the above-mentioned conventional solenoid has a problem that the number of parts is large and the cost reduction is limited.

Therefore, the present applicant has filed a Japanese Patent Application No. 9-1610.
In No. 26, the pipe of the tube assembly is omitted, and the resin bobbin also serves as a pipe, and the stopper of the tube assembly is omitted, and the resin bobbin also serves as a stopper. A solenoid has been proposed in which the case is mounted on the valve body such that the case covers the entire internal components such as the bobbin.

However, the following problems have been found in such proposals. In other words, by using the resin bobbin as the stopper, the number of parts can be reduced, but the stopper repeatedly repeats the impact force of the movable core every time the movable core separates from the fixed core. As a result, deterioration and damage of the resin bobbin are promoted.

In view of the above-described new problems, the present invention has a structure in which the impact force of the movable iron core is received on the case side, whereby deterioration and damage of the bobbin can be prevented, and the strength and durability are excellent. It is to provide a solenoid.

[0013]

A solenoid according to the present invention comprises a bobbin having a bottomed cylindrical portion in which a movable iron core and a fixed iron core are disposed, and a bottom opposed to the bottom wall of the bobbin bottomed cylindrical portion. A solenoid having a wall and a case attached to the valve body by a fitting while the bobbin is housed therein, wherein a solenoid formed on the bobbin bottom wall along a virtual axis of the movable iron core. A first through-hole, a second through-hole having an internal thread and formed in the bottom wall of the case along a virtual axis of the first through-hole, and a sliding contact portion slidingly contacting the first through-hole; A stopper member having a protrusion protruding into the bottomed cylindrical portion, a male screw portion meshing with the female screw of the second through hole, and a head rotatable from the outside is provided. .

Here, the bobbin is, for example, a resin bobbin.

[0015]

According to the solenoid of the present invention, the solenoid coil of the solenoid is demagnetized, and the solenoid coil of the other solenoid, which forms a pair of left and right solenoids together with the solenoid, is excited, whereby the movable iron core of the solenoid is excited. When the is separated from the fixed iron core, the protrusion of the stopper member comes into contact with the movable iron core and receives an impact force. This impact force is not transmitted to the bobbin because the sliding portion of the stopper member is in sliding contact with the first through hole of the bobbin. Instead, the stopper member is inserted into the female screw of the second through hole of the case. Is transmitted to the case since the male screw portions of the first and second gears are engaged with each other.

Therefore, since the bobbin is not subjected to the impact force of the movable iron core, deterioration and damage of the bobbin can be prevented, and a solenoid excellent in strength and durability can be provided.

[0017]

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

FIG. 1 is a sectional view showing a state in which a solenoid 5 according to one embodiment is mounted on a valve body 7 of an oil immersion type solenoid valve.

Referring to FIG. 1, the solenoid 5 of this embodiment
Is a resin bobbin 5 around which a solenoid coil 51 is wound.
2 and the valve body 7 with the bobbin 52 housed therein.
The case 5 attached to the fixture 8 by a screw, for example.
3 is provided.

The bobbin 52 has a bottomed cylindrical portion 52a.
A movable iron core 32 and a fixed iron core 31 are arranged inside the bottomed cylindrical portion 52a. An upper end surface of a push pin 35 is in contact with a lower end surface of the movable iron core 32, and the push pin 35 passes through a through hole 31 b of the fixed iron core 31, and a lower end surface thereof is in contact with an upper end surface of the spool 37. Also,
A spring 3 is provided inside the through hole 31 b of the fixed iron core 31.
6 are stored.

A first through hole 52 is formed in the bottom wall 52b of the bobbin bottomed cylindrical portion 52a along the virtual axis L of the movable iron core 32.
c is formed.

The case 53 is made of a magnetic material and has a bottom wall 53a facing the bottom wall 52b of the bobbin bottomed cylindrical portion 52a.

A bobbin bottom wall 52b is provided on the case bottom wall 53a.
Along the virtual axis L of the first through hole 52c of the second through hole 5c.
3b is formed. A female screw is formed in the second through hole 53b.

A stopper member 54 is disposed inside the first through hole 52c and the second through hole 53b. The stopper member 54 is provided in the sliding contact portion 5 that is in sliding contact with the first through hole 52c.
4a and a protruding portion 54b protruding into the bottomed cylindrical portion 52a.
And a male screw portion 54 that meshes with the female screw of the second through hole 53b.
c and a head 54d that can be rotated from the outside.
Sliding contact portion 54a between first through hole 52c and stopper member 54
An O-ring 55 is provided between the two to secure the sealing performance.

In addition, between the flange 52d of the bobbin 52 and the case 53, a donut plate-shaped yoke 56 is arranged. Reference numeral 38 in the drawing denotes a spring receiver, 57
Represents a lead wire of the solenoid coil 51, and 58 represents an O-ring.

In the solenoid 5 configured as described above, when the solenoid coil 51 of the solenoid 5 is energized, and when the solenoid coil of another solenoid (not shown) is de-energized, the solenoid coil 51 is excited. The movable iron core 32 receives magnetic attraction from the fixed iron core 31 and is in a state of approaching the fixed iron core 31.

Thereafter, when the energization of the solenoid coil 51 is stopped and the solenoid coil of another solenoid is energized, the magnetic attraction force of the fixed iron core 31 to the movable iron core 32 disappears, and the other solenoid coil excites another magnet. The movable core is attracted to other fixed cores,
The spool 37 pushes the push pin 35 against the elastic force of the spring 36, and the movable core 32 is separated from the fixed core 31.

Then, the movable core 32 abuts on the protrusion 54 b of the stopper member 54, and the protrusion 54 b receives an impact force from the movable core 32. This impact force is not transmitted to the bobbin 52 because the sliding contact portion 54a of the stopper member 54 is in sliding contact with the first through hole 52c of the bobbin 52. Since the male screw portion 54c of the stopper member 54 is in mesh with the female screw of the hole 53b, the male screw portion 54c is transmitted to the case 53 and absorbed and reduced in the mounting bracket 8.

Therefore, since the bobbin 52 is not subjected to the impact force of the movable iron core 32, deterioration and damage of the bobbin 52 can be prevented, and a solenoid having excellent strength and durability can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which a solenoid according to one embodiment is mounted on a valve body of an oil immersion type electromagnetic valve.

FIG. 2 is a sectional view of a conventional solenoid.

[Explanation of symbols]

 Reference Signs List 5 solenoid 52 bobbin 52a bottomed cylindrical part 52b bottom wall 52c first through hole 53 case 53a bottom wall 53b second through hole 54 stopper member 54a sliding contact part 54b projecting part 54c male screw part 54d head 7 valve body 31 fixed iron core 32 Movable iron core L Virtual axis

Claims (2)

[Claims] 1. A bobbin having a bottomed cylindrical portion in which a movable core and a fixed core are disposed, and a bottom wall facing the bottom wall of the bobbin bottomed cylindrical portion, wherein the bobbin is provided inside. A solenoid that includes a case that is attached to the valve body by a mounting bracket in a housed state, the solenoid having a first through hole formed in the bobbin bottom wall along a virtual axis of the movable iron core, and a female screw; A second through-hole formed in the bottom wall of the case along an imaginary axis of the first through-hole; a sliding contact portion slidingly contacting the first through-hole; and protruding into the bottomed cylindrical portion. A solenoid comprising: a protrusion; a male screw portion meshing with a female screw of the second through-hole; and a stopper member having a head rotatable from the outside. 2. The solenoid according to claim 1, wherein the bobbin is a resin bobbin.