JPH09306728A - Electromagnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnet which may be manufactured at a low cost and enables secure fixing of a residual magnetism prevention spacer. SOLUTION: On the inner peripheral surface of a bobbin 3 which is formed in a hollow shape and has a coil 2 wound thereon, a large-diameter part 3a and a small-diameter part 3b are formed in two stages. A fixed core 5 is fitted with the large-diameter part 3a, and a moving core 7 is fitted with the small- diameter part 3b in such a manner as to enable movement toward and away from the fixed core 5. In addition, a residual magnetism prevention spacer 6 is arranged on a step surface 3c formed on the inner peripheral surface of the bobbin 3. The residual magnetism prevention spacer 6 is fixed by the step surface 3c and a distal end surface of an axis part 5a of the fixed core 5.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an electromagnet,
More specifically, it relates to fixing a residual magnetism prevention spacer disposed in an electromagnet.

[0002]

2. Description of the Related Art Generally, when an electromagnet is energized by a coil, a magnetic flux is generated between a yoke, a movable iron core and a fixed iron core, and the movable iron core is moved toward the fixed iron core by its magnetic force. When the energization of the coil is stopped, the magnetic flux disappears, and the movable iron core is returned to the original position by a spring or the like. When the coil is de-energized and the movable core returns to its original position, if there is residual magnetism between the movable core and the fixed core, the movable core is attracted to the fixed core due to a slight magnetic force and the return is delayed. For example, it affects the performance of the valve. Therefore, in the electromagnet, usually, a spacer for preventing residual magnetism of a non-magnetic material is fixed to the movable iron core between the movable iron core and the fixed iron core.

As shown in FIGS. 3 to 6, a conventional residual magnetism preventing spacer is fixed to a movable iron core in various states.

In the electromagnet S3 shown in FIG.
Inside, a bobbin 23 around which the coil 22 is wound is disposed,
The fixed iron core 25 is provided so as to be fixed to one of the bobbins 23. A movable iron core 27 is provided on the other
However, the pin 28 formed in a two-stage diameter has a small diameter portion 28a.
Is disposed so as to be press-fitted, and the large-diameter portion 28b of the pin 28 is
Are slidably fitted in the shaft hole 25a of the fixed iron core 25. Further, on the side of the movable iron core 27 facing the fixed iron core 25, a valve connecting pin 29 is fixed along the axis so as to be connected to a valve (not shown). And
The spacer 26 for preventing residual magnetism is pinched between the end face of the movable iron core 27 and the large diameter portion 28a of the pin 28.
8 is supported and arranged on the outer periphery of the small diameter portion 28a.

When the coil 22 is energized, the movable iron core 27 is attracted to the fixed iron core 25 side. Therefore, when the coil 22 is de-energized, the movable iron core 27 is released by a spring (not shown). The valve is returned to its original position, and at the same time, the valve is also returned.

The electromagnet S4 shown in FIG. 4 differs from the electromagnet S3 of FIG. 3 in that the residual magnetism prevention spacer 36 is supported by the large diameter portion 38b of the pin 38 press-fitted into the movable iron core 37. However, the large diameter portion 38b of the pin 38 slides in the shaft hole 35a of the fixed iron core 35, and other configurations are the same as those of the electromagnet S3 in FIG.

In the electromagnet S5 shown in FIG. 5, the residual magnetism prevention spacer 46 is fixed to the movable iron core 47 by bolts 48 toward the fixed iron core 45 side. A hole 45a into which the head of the bolt 48 is loosely fitted is formed in the fixed iron core 45.

In the electromagnet S6 shown in FIG. 6, the residual magnetism preventing spacer 56 is made of a movable core 5 by an adhesive.
7 is fixed to the fixed iron core 55 side.

The movable iron core 3 of the electromagnet shown in FIGS.
Valve coupling pins 39, 49, 59, which are coupled to the illustrated in-core valves, are provided on the opposite sides of the fixed iron cores 35, 45, 55 of 7, 47, 57 from the movable iron cores 37, 47, 5 respectively.
It is pressed into 7.

[0010]

However, the fixing of the spacer for preventing residual magnetism to the movable iron core in the conventional electromagnet has the following problems.

In the electromagnets S3 and S4 shown in FIGS. 3 and 4, the pins 28 and 38 must be newly manufactured, which not only increases the number of parts but also guides the pins 28 and 38 to the fixed iron cores 25 and 35. Since the holes 25a and 35a to be formed are formed, the processing cost is increased. Further, in the electromagnet of FIG. 4, when the pin 38 comes out of the hole 35a of the fixed iron core 35, the residual magnetism prevention spacer 36 is likely to fall.

In the electromagnet S5 in FIG. 5, since the bolt 48 is fastened, when the screw of the bolt 48 is loosened, the head of the bolt 48 interferes with other parts, or the bolt 48 comes off to prevent residual magnetism. 46 easily falls. Also,
In the electromagnet S6 in FIG. 6, since the residual magnetism prevention spacer 56 is fixed by the adhesive, the adhesive is easily peeled off and dropped.

The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide an electromagnet capable of preventing an increase in cost and reliably fixing a spacer for preventing residual magnetism to a movable iron core.

[0014]

An electromagnet according to the present invention has the following configuration to solve the above-mentioned problems. That is, a bobbin formed in a hollow shape around which a coil is wound, a fixed iron core arranged on the inner peripheral surface of the bobbin, and a movable iron core movably arranged with respect to the fixed iron core. An electromagnet comprising, the inner peripheral surface of the bobbin is formed in a large diameter portion and a small diameter portion, a movable iron core is movably fitted to the small diameter portion, the large diameter portion,
While the fixed iron core is fitted, a residual magnetism prevention spacer is arranged so as to come into contact with the step surface of the large diameter portion and the small diameter portion, and the residual magnet is prevented by the step surface and the fixed iron core. It is characterized in that it is configured to fix the anti-magnetic spacer.

Further, this electromagnet has a hollow bobbin around which a coil is wound, a fixed iron core arranged on the inner peripheral surface of the bobbin, and a movable iron core movably with respect to the fixed iron core. And a movable iron core, wherein the inner peripheral surface of the bobbin is formed into a large diameter portion and a small diameter portion, a fixed iron core is fitted to the small diameter portion, the large diameter portion , A pipe in which the movable core is movably arranged is fitted, and a spacer for preventing residual magnetism is arranged so as to come into contact with the stepped surface of the large diameter portion and the small diameter portion. The surface and the pipe are configured to fix the residual magnetism preventing spacer.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an electromagnet S1 according to a first embodiment of the present invention. Coil 2 in case 1
The bobbin 3 around which the bobbin 3 is wound is disposed, and the yoke 4 is disposed so as to be adjacent to one side portion of the bobbin 3. The bobbin 3 and the yoke 4 are formed in a hollow shape, and the inner peripheral surface of the bobbin 3 is formed in two steps of a large diameter portion 3a and a small diameter portion 3b. The shaft portion 5a of the fixed iron core 5 formed in a flange shape is fitted to the large diameter portion 3a, and the flange portion 5b is fixed to the case 1 so as to be adjacent to the other side portion of the bobbin 3.

A spacer 6 for preventing residual magnetism of a non-magnetic material is arranged at the tip (left side in FIG. 1) of the large diameter portion 3a of the bobbin 3 on the side of the small diameter portion 3b. The tip surface (the left side in FIG. 1) of the shaft portion 5a of the fixed iron core 5 is brought into contact with the
The stepped surface 3c formed on the inner peripheral surface of the bobbin 3 and the fixed iron core 5 are fixed so as to sandwich the spacer 6 for preventing residual magnetism. The residual magnetism prevention spacer 6 is formed in a disk shape, and a hole is formed in the central portion.

A movable iron core 7 is movably fitted to the small-diameter portion 3b of the bobbin 3 so as to move toward and away from the fixed iron core 5. The pin 9 is press-fitted into the shaft portion of the movable iron core 7 on the side of the movable iron core 7 facing the fixed iron core 5 side, and the valve B1 is connected to the tip of the pin 9 to form a hydraulic circuit. A coil spring 10 is arranged around the pin 9 and biases the movable iron core 7 in a direction separating from the fixed iron core 5.

When the coil 2 of the electromagnet S1 thus constructed is energized, a magnetic flux is generated in the yoke 2, the fixed iron core 5, and the movable iron core 7, and the movable iron core 7 moves toward the fixed iron core 5 in the figure. , Move to the right. The valve B1 is moved to the right along with the movement of the movable iron core 7, and is operated so that the hydraulic pressure flows.

When the coil 2 is de-energized, the magnetic flux disappears, and the movable iron core 7 is moved leftward in FIG. 1 by the coil spring 10. At this time, a small amount of residual magnetism remains between the movable iron core 7 and the fixed iron core 5, but the spacer 6 for preventing residual magnetism of a non-magnetic material blocks the residual magnetism, so the movable iron core 7
Moves smoothly, and the response delay of the valve B1 does not occur.

FIG. 2 shows an electromagnet S2 according to the first embodiment of the present invention. A bobbin 13 around which the coil 12 is wound is arranged in the case 11, and a yoke 14 is arranged so as to be adjacent to one side portion of the bobbin 13. The bobbin 13 and the yoke 14 are formed in a hollow shape, and the inner peripheral surface of the bobbin 13 is formed in two steps of a large diameter portion 13a and a small diameter portion 13b. The shaft portion 15a of the fixed iron core 15 formed in a flange shape is fitted to the small diameter portion 13b, and is fixed to the case 11 so that the flange portion 15b is adjacent to the other side portion of the bobbin 13.

Large diameter portion 13a of small diameter portion 13b of bobbin 13
A spacer 16 for preventing remanent magnetism of a non-magnetic material is provided at the side end (right side in FIG. 2), and a pipe 18 is fitted to the inner peripheral surface of the large diameter portion 13a to prevent remanent magnetism. The tip surface (right side in FIG. 2) of the pipe 18 is brought into contact with the spacer 16, and the step surface 13c formed on the inner peripheral surface of the bobbin 13 and the pipe 1
8 and 8 are fixed so as to sandwich the residual magnetism preventing spacer 16. The residual magnetism-preventing spacer 16 is formed in a disk shape, and a hole is formed in the center thereof.

The movable iron core 17 is movably fitted to the inner peripheral surface of the pipe 18 so as to move toward and away from the fixed iron core 15. The pin 19 is press-fitted into the shaft portion of the movable iron core 17 on the side of the movable iron core 17 facing the fixed iron core 15 side, and the valve B2 is connected to the tip end portion of the pin 19 to form a hydraulic circuit. A coil spring 20 is provided around the pin 19.
Is arranged to urge the movable iron core 17 in a direction away from the fixed iron core 15.

When the coil 12 of the electromagnet S2 thus constructed is energized, a magnetic flux is generated in the yoke 12, the fixed iron core 15 and the movable iron core 17, and the movable iron core 17 is fixed to the fixed iron core 1.
It moves to the right in FIG. 2 toward 5. Movable iron core 1
With the movement of 7, the valve B2 is moved to the right and operated so that the hydraulic pressure flows.

When the coil 2 is de-energized, the magnetic flux disappears, and the movable iron core 17 is moved by the coil spring 20 in FIG.
Move to the left. At this time, the movable iron core 17 and the fixed iron core 1
Although the residual magnetism slightly remains between the spacer 5 and the magnet 5, the spacer 1 for preventing the residual magnetism of the non-magnetic material is used as in the first embodiment.
Since 6 blocks the residual magnetism, the movable iron core 17 is moved smoothly and the response delay of the valve B2 does not occur.

In the present embodiment, the fixed iron core is described as being arranged at the position opposite to the valve side with respect to the movable iron core, but the electromagnet of the present invention is not limited to this. It may be used in a type in which the fixed core is located between the movable core and the valve.

[0028]

As described above, according to the electromagnet of the first aspect, the bobbin formed in a hollow shape and around which the coil is wound, the fixed iron core arranged on the inner peripheral surface of the bobbin, and the fixed And a movable iron core arranged so as to be movable with respect to the iron core. An inner peripheral surface of the bobbin is formed into a large diameter portion and a small diameter portion, and a movable iron core is movably fitted to the small diameter portion. Further, the large-diameter portion is fitted with the fixed iron core, and a residual magnetism prevention spacer is arranged so as to come into contact with the step surface of the large-diameter portion and the small-diameter portion,
Since the residual magnetism preventing spacer is fixed by the stepped surface and the fixed iron core, the residual magnetism preventing spacer can be securely fixed without dropping. Moreover, since it is not necessary to add new parts, it can be manufactured inexpensively without increasing the cost.

Further, according to the electromagnet of claim 2, the electromagnet includes a bobbin formed in a hollow shape and around which a coil is wound, a fixed core provided on an inner peripheral surface of the bobbin, and the fixed core. On the other hand, a movable iron core movably arranged is provided. The inner peripheral surface of the bobbin is formed into a large diameter portion and a small diameter portion, and a fixed iron core is fitted in the small diameter portion. Further, a pipe in which the movable iron core is movably arranged is fitted in the large-diameter portion, and a residual magnetism preventing space is brought into contact with a step surface of the large-diameter portion and the small-diameter portion. Since the spacer is arranged and the residual magnetism preventive spacer is fixed by the step surface and the pipe, the residual magnetism preventive spacer is securely fixed without dropping. be able to. Moreover, since it is not necessary to add new parts, it can be manufactured inexpensively without increasing the cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing an electromagnet according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing an electromagnet according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional electromagnet.

FIG. 4 is a view showing a fixed state of a spacer for preventing residual magnetism of another conventional electromagnet.

FIG. 5 is a diagram showing a fixed state of a spacer for preventing residual magnetism of another conventional electromagnet.

FIG. 6 is a view showing a fixed state of a spacer for preventing residual magnetism of another conventional electromagnet.

[Explanation of symbols]

 S1, S2 ... Electromagnets 2, 12 ... Coils 3, 13 ... Bobbins 3a, 13a ... Large diameter portions 3b, 13b ... Small diameter portions 3c, 13c ... Step surfaces 5, 15 ... Fixed iron core 6, 16 ... Spares for preventing residual magnetism Service 7, 17 ... Movable iron core 18 ... Pipe

Claims (2)

[Claims] 1. A bobbin formed in a hollow shape and around which a coil is wound, and a fixed iron core disposed on an inner peripheral surface of the bobbin;
An electromagnet comprising a movable iron core movably arranged with respect to the fixed iron core, wherein an inner peripheral surface of the bobbin is formed into a large diameter portion and a small diameter portion, and the small diameter portion includes a movable iron core. Is movably fitted, the fixed core is fitted to the large-diameter portion,
A residual magnetism preventing spacer is disposed so as to abut the step surfaces of the large diameter portion and the small diameter portion, and the residual magnetism preventing spacer is fixed by the step surface and the fixed iron core. An electromagnet, which is characterized in that 2. A bobbin formed in a hollow shape and around which a coil is wound, and a fixed iron core arranged on an inner peripheral surface of the bobbin.
An electromagnet comprising a movable iron core movably arranged with respect to the fixed iron core, wherein an inner peripheral surface of the bobbin is formed into a large diameter portion and a small diameter portion, and the small diameter portion is fixed. An iron core is fitted, a pipe in which the movable iron core is movably arranged is fitted in the large-diameter portion, and the residual magnetism is made to abut on the step surface of the large-diameter portion and the small-diameter portion. An electromagnet, wherein a preventive spacer is provided, and the residual magnetism preventive spacer is fixed by the step surface and the pipe.