JPH1140411A - Electromagnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnet capable of lowering cost by decreasing a total number of parts, protecting a tube of nonmagnetic material, and improving a magnetic circuit. SOLUTION: The electromagnet comprises a magnetic external case and a tube assy 5 secured in the external case. One end of the external case has a flange and secure the tube assy 5, and the other end has a magnetic body 3 having an opening 3b, a magnetic protective cap 4 placed through the opening 3b of the body 3, and a packing made of rubber placed between the opening 3b and the protective cap 4. The protective cap 4 has a flange face 4a and a projection 4b protruding from the flange face 4a to the outside of the body 3, and is formed with its cross section in approximately reversed c character. A bobbin 6 has a backside wall and is formed with its top end in an opening cylinder and the inside face of the bobbin 6 has a first fitting face fitted by a fixed iron core and a second fitting face movably fitted by a moving iron core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet having a tube in which a fixed iron core and a movable iron core are disposed, wherein the movable iron core is excited by a coil and slides in the tube. .

[0002]

2. Description of the Related Art Conventionally, an electromagnet has a bobbin formed in a hollow shape, a magnetic coil wound around the bobbin, a fixed iron core disposed in the bobbin, and a sliding member which is close to and separated from the fixed iron core. A movable iron core to be moved. And
Generally, the movable core is operated so as to be attracted to the fixed core by excitation of the magnetic coil.

The electromagnet 20 shown in FIG. 6 is widely used as an oil immersion type for a hydraulic solenoid valve or the like. This electromagnet 20
A coil assembly 21; a tube assembly 26 fitted into the coil assembly 21;
And a nut 31 for fixing the tube assembly 26 and the coil assembly 21. The coil assembly 21 has a hollow bobbin 24 in which a magnetic coil 23 is wound in a hollow round outer case 22 and a yoke. The tube assembly 26 has a fixed iron core 27 and a movable iron core 28, and further has a pipe 29 for fitting the fixed iron core 27 and the movable iron core 28. I have. The pipe 29 is formed of a ring-shaped non-magnetic material, is inserted into the inner peripheral surface of the hollow portion of the bobbin 24, and has one end connected to the fixed core 2.
A movable iron core 28 that engages with and is welded to the inner core 7 and that approaches and separates from the fixed iron core 27 is slidably disposed on the inner peripheral surface.
A stopper 30 is welded to the other end of the pipe 29, and a nut 31 is screwed and attached to the stopper 30 in order to integrally fix the coil assembly 21 and the tube assembly 26.

The fixed iron core 27 has a through hole 27a including an oil passage through which a pin (not shown) is inserted along the central axis, and a male screw 27b formed at the outer periphery of the distal end portion. Attached to. An oil groove 28a for circulating oil is formed in one or both outer peripheral surfaces of the movable core 28 in the axial direction, and oil flowing from the fixed core 27 side circulates through the movable core 28 to the stopper 30 side. It had been. And a seal for preventing oil leakage was provided at a necessary place.

[0005]

However, as price competition intensifies, it is necessary to review the price of conventional electromagnets. In particular, an oil immersion type electromagnet 20
Is a non-magnetic pipe because oil circulates inside.
9 are arranged. One end of the pipe 29 is a fixed iron core 27
And the other end is disposed so as to protrude rearward from the outer case 22, so that the stopper 30 for closing the hollow portion of the pipe 29 is required. However, since the reduction in the number of parts leads to a cost reduction in the price review, the parts have been reviewed especially by removing the stopper 30 and the nut 31.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide an electromagnet which can reduce costs by eliminating conventional nuts, stoppers and yokes.

[0007]

An electromagnet according to the present invention has the following configuration to solve the above-mentioned problems. That is, an outer case having one end opened,
A tube assembly housed in the outer case, wherein the tube assembly has a fixed iron core and a movable iron core that slides toward and away from the fixed iron core. An electromagnet configured to include a tube, wherein the tube is formed of a non-magnetic material, and is formed in a cylindrical shape so that one end is opened and the other end is closed with a rear wall, An outer case penetrates the opening from the main body of the magnetic body having a mounting flange at one end and an opening at the other end, a flange surface disposed on an inner side surface around the opening, and the flange surface. And a magnetic material protective cap having a protrusion protruding outward and closing the inside.

Preferably, the tube is a bobbin around which a coil is wound, and the bobbin is formed so as to cover one end, and is formed outward from an outer peripheral surface. A pair of coil housing wall portions, and a flange plate formed outwardly from one wall portion of the coil housing wall via a gap portion, and is integrally formed. Any feature may be used.

[0009] More preferably, the tube may be a pipe housed in a bobbin around which a coil is wound.

[0010] Further, an elastic member for crimping the outer peripheral surface of the protective cap portion is provided between the opening of the outer case and the protective cap portion. .

[0011]

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

As shown in FIG. 1, the electromagnet 1 of the present embodiment
The outer case 2 includes a round outer case 2 and a tube assembly 5 disposed in the outer case 2.
The bobbin 6 includes a coil 7 arranged to wind the bobbin 6, and a fixed iron core 9 and a movable iron core 11 arranged in the bobbin 6.

The outer case 2 is made of a magnetic material, and has a flange 3a at a front end (downward in FIG. 2) as shown in FIG. 2, for accommodating the tube assembly 5 and a rear end (FIG. 2). , Upper part), a protective cap part 4 attached so as to penetrate the opening part 3b, and a packing 13 disposed between the protective cap part 4 and the opening part 3b. It is configured. The protective cap portion 4 has a flange surface 4a and is formed in a substantially U-shaped cross section.
The flange surface 4a is disposed on the inner side surface around the opening 3b of the main body 3, and the projection 4b protruding outward from the main body 3 through the opening 3b from the flange surface 4a has a rear wall 4c. Closed. The main body 3 and the protective cap 4 are both formed of a magnetic material as described above, and are formed mainly by press working.

Further, an elastic rubber packing 1 is provided between the opening 3b of the main body 3 and the protective cap 4 so that water, dust and the like do not enter the outer case 2 through the opening 3b.
3 are provided. As shown in FIG. 2, the packing 13 has a hole 13a through which the protective cap portion 4 is inserted at the center.
And has a flange portion 13b on both upper and lower end surfaces, and is fitted into the opening 3b. Therefore,
The rubber packing 12 fitted in the opening 3b is inserted into the protective cap portion 4 and then pressure-bonded to the outer peripheral surface of the protective cap portion 4, whereby waterproofing and dustproofing from outside can be achieved.

The outer case 2 can be formed by pressing the main body portion and the protective cap portion integrally with each other by pressing. In that case, however, deep drawing is performed, and a large outer case is particularly required. In this case, since deep drawing requires a long processing time, the main body and the protective cap are separately formed and press-formed. In this case, since the protective cap 4 serves as a conventional yoke, the yoke can be omitted and the magnetic circuit is improved.

The tube assembly 5 has a tube in which a fixed iron core 9 and a movable iron core 11 are disposed. The tube in this embodiment is a bobbin 6 around which a coil 7 is wound.

The bobbin 6 is formed of a non-magnetic material and has a cylindrical shape. The bobbin 6 has a front end opened and a rear end closed with a rear wall 6a. A pair of coil storage walls 61 and 62 are formed on the outer peripheral surfaces of the front end portion and the intermediate portion of the bobbin 6 so as to be outwardly received in the outer case 2. The coil 7 is wound and stored. A disk-shaped flange plate 63 is formed on the rear end side so as to be housed in the outer case 2 at a distance from the coil storage wall 62 on the rear side. 63
The lead wire 7a of the coil 7 is inserted into the gap 6b formed between
Is stored, and a flange surface 4 a of the protective cap portion 4 of the outer case 2 is disposed between the flange plate 63 and the rear end surface of the main body 3 of the outer case 2.

A stopper 64 is formed inside the rear wall 6a of the bobbin 6 so as to protrude inward, so that when the movable core 11 comes into contact with the rear wall 6a, the movable core 11 is adhered so as not to be in close contact with oil. The area is reduced.

Further, on the inner peripheral surface of the bobbin 6, a first fitting surface 65 which fits with the fixed iron core 9 is formed on the front end side, and is connected to the first fitting surface 65 and is formed on the rear end side. A second fitting surface 66 to which the movable iron core 11 is fitted is formed. And the first
The fitting surface 65 is formed to have a larger diameter than the second fitting surface 66, and the fixed core 9 is positioned by the rear end surface of the fixed core 9 abutting the front end surface of the second fitting surface 66.

As shown in FIG. 3, a plurality of concave oil grooves 67 are formed in the second fitting surface 66 of the bobbin 6 along the axial direction to form an oil passage. The number of the oil grooves 67 may be only one, or a plurality of oil grooves may be formed at equal intervals.

As shown in FIG. 4, the oil passage may be formed by forming ribs 68 projecting inward at equal intervals along the axial direction on the second fitting surface 66. . In this case, if the tip of the rib 68 is formed in an arc surface and the movable iron core 11 is slidably fitted to the end surface 68a of the arc surface, an oil passage is formed between the ribs 68.

The fixed iron core 9 is fitted to the first fitting surface 65 of the bobbin 6 as described above, and has a recess at its rear end surface and abuts against the front end surface of the second fitting surface 66 to fix the fixed iron core 9.
Is projected forward from the coil housing wall 61 on the front end surface of the bobbin 6. An O-ring 15 is attached between the fixed iron core 9 and the front end inside the bobbin 6. Further, a through hole 9a is formed in the axial center portion of the fixed iron core 9, and serves as a passage for an oil (not shown) into which a pin (not shown) is inserted and which flows in from the outside.

The movable core 1 is provided on the rear end face of the fixed core 9.
A rib is formed to reduce residual magnetism at the time of release of the adsorption with the first.

The movable core 11 is formed in a round shape so as to be slidably fitted to the second fitting surface 66 of the bobbin 6 as described above, and engages with the concave portion of the fixed core 9 on the front end surface. Protrusions are formed. Then, the coil 7 is attracted to the fixed iron core 9 by the excitation, and the coil 7 is released from the excitation, thereby sliding toward the rear wall 6a of the bobbin 6 by the urging force of a spring (not shown).

The electromagnet 1 configured as described above constitutes a hydraulic solenoid valve by attaching the flange portion 3a of the outer case 2 to, for example, a hydraulic valve body. In this case, a pin (not shown) for moving the spool of the valve element is disposed between the movable iron core 9 and the valve element while being inserted into the through hole 9a of the fixed iron element 9. Since the pin is round and has cutout surfaces on both sides, oil flows into the electromagnet 1 from between the through hole 9a and the cutout surface of the pin. When the coil 7 is excited, a magnetic field is generated in the fixed iron core 9, the movable iron core 11, the main body part 3 of the outer case 2, and the protective cap part 4,
The movable iron core 11 moves in a direction in which it is attracted to the fixed iron core 9,
The protrusion of the movable core 11 is engaged with the recess of the fixed core 9.

When the excitation of the coil 7 is released, the magnetic field is demagnetized between the fixed iron core 9 and the movable iron core 11, so that the movable iron core 11 is separated from the fixed iron core 9 via the pin by a spring (not shown). Will move in that direction. The movable core 11 is returned from a position where the movable core 11 is attracted to the fixed core 9 to a position where the movable core 11 comes into contact with the stopper 64 of the rear wall 6 a of the bobbin 6.

As described above, in the electromagnet 1, the bobbin 6 as a tube is formed in a cylindrical shape with the rear wall 6a at the rear end, and the outer case 2 is composed of the magnetic body 3 and the protective cap 4. Therefore, it is possible to protect the non-magnetic bobbin 6 and to form a magnetic path, so that the conventional yoke can be omitted. Therefore, the number of parts can be significantly reduced, and the cost can be reduced because the main body 3 and the protective cap 4 of the outer case 2 can be processed in a short time by pressing.

The electromagnet of the present invention can be modified without being limited to the above-described embodiments without departing from the scope of the claims.

An electromagnet 1A shown in FIG. 5 shows a case where a tube constituting a tube assembly is a tubular pipe housed in a bobbin. Therefore, the configuration of the outer case 2 is the same as that of the above-described embodiment shown in FIG.

The tube assembly 5A includes a bobbin 71 disposed in the outer case 2, a coil 72 disposed around the bobbin 71, a pipe 73 disposed in the bobbin 71, and a pipe 73 disposed in the pipe 73. Fixed core 75 to be placed
And a movable iron core 77.

The bobbin 71 is formed of a non-magnetic material such as resin and has a hollow shape, and is disposed in the outer case 2. The bobbin 71 has a pair of wall portions 71a for accommodating the coil 72 on an outer peripheral surface thereof, and a pipe 73 is fitted on an inner peripheral surface thereof. Between the bobbin 71 and the rear end of the outer case body 3, the flange surface 4a of the protection cap 4 of the outer case 2 is arranged, and the fixed core 75, the movable core 77, the body 3 of the outer case 2 and the protection are provided. It is configured so that a magnetic field can be generated with the cap 4.

The pipe 73 is formed of a non-magnetic material in a cylindrical shape, and has a front end opened and a rear end provided with a rear wall 73a, and is integrally formed by press deep drawing or resin molding. Is done. A stopper 73b is formed inwardly inside the rear wall 73a of the pipe 73 to reduce the contact area of the movable iron core 77 so that the movable iron core 77 does not come into close contact with the oil when it comes into contact with the rear wall 73a. . Also,
A corrugated washer 17 is provided between the rear wall 73a of the pipe 73 and the rear wall 4c of the outer case 2 so as to press the pipe 73 so as to eliminate the play between the fixed iron core 75 and the valve element. I have.

The fixed iron core 75 has an outer peripheral surface formed in two steps.
The large diameter portion 75a is inserted into the front end of the bobbin 71 as described above, and the small diameter portion 75b is fitted to the pipe 73. An O-ring 79 fitted to the fixed iron core 75 is disposed between the outer peripheral surface of the small diameter portion 75b and the inner peripheral surface of the pipe 73, so as to seal oil flowing into the pipe 73. doing. The front end face of the fixed iron core 75 projects forward from the front end face of the bobbin 71, and a recess is formed in the rear end face. Further, a through hole 75c is formed in the axial center of the fixed iron core 75.
Are formed, and play a role as a passage for oil which is inserted from the outside while a pin (not shown) is inserted.
In FIG. 5, another O-ring 80 is shown on the tip side of the fixed iron core 75. This is provided so that when the electromagnet 1A is attached to a valve (not shown), a sealing action is performed between the valve and the valve. Further, a rib is formed on the rear end surface of the fixed iron core 75 to reduce residual magnetism when releasing the suction from the movable iron core 77.

The movable iron core 77 is connected to the pipe 73 as described above.
Is formed in a round shape so as to be slidably fitted to the inner peripheral surface of the inner surface, and an oil groove 77a is formed partially along the axial direction. Therefore, the oil flowing from the fixed iron core 75 is circulated into the pipe 73 through the oil groove 77a of the movable iron core 77. Further, on the front end surface of the movable iron core 77, a convex portion that engages with the concave portion of the fixed iron core 75 is formed. Then, it is attracted to the fixed iron core 75 by the excitation of the coil 72, and slides toward the rear wall 73 a of the pipe 73 by the urging force of a spring (not shown) by releasing the excitation of the coil 72.

Accordingly, in this electromagnet 1, since the pipe 73 is integrally formed in a cylindrical shape with the rear wall 7a at the rear end, the conventional stopper and nut can be omitted, and the outside can be removed. Since the protective cap 4 of the case 2 replaces the conventional yoke, the yoke can be omitted. Furthermore, only one O-ring 79 disposed on the fixed iron core 75 and the pipe 73 is required to seal the oil flowing into the electromagnet 1, and the cost can be reduced in this respect as well.

As described above, the electromagnet of the present invention can cope with various types of tubes, and other configurations are not limited to the above.

[0037]

According to the present invention, an electromagnet includes an outer case having one end opened, and a tube assembly housed in the outer case, wherein the tube assembly includes a fixed iron core and the fixed iron core. And a movable iron core that slides so as to approach and separate from the movable iron core. The tube is formed of a non-magnetic material, and is formed in a tubular shape so that one end is opened and the other end is closed with a rear wall, and the outer case has a mounting flange at one end. A main body portion of a magnetic body having an opening at the other end, a flange surface disposed on an inner side surface around the opening, and a cross section substantially coaxial so as to protrude outward from the flange surface through the opening. And a protective cap portion made of a magnetic material having a protrusion formed in a character shape. Therefore, this electromagnet can eliminate the conventional nut and stopper, and can also eliminate the conventional yoke, and can reduce the cost. In addition, the tube made of a non-magnetic material can be protected and the magnetic circuit can be improved.

In this electromagnet, the tube constituting the tube assembly is a bobbin closing one end,
The present invention can be applied to a pipe housed in the bobbin.

Further, by interposing an elastic member between the opening of the outer case and the protective cap portion, waterproof and dustproof measures can be taken from the outside.

[Brief description of the drawings]

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

FIG. 2 is a partial sectional view showing a part of the outer case in FIG. 1;

FIG. 3 is a sectional view showing an oil groove (oil groove portion) of the bobbin in FIG. 1;

FIG. 4 is a side sectional view showing another embodiment of FIG. 3;

FIG. 5 is a sectional view showing an electromagnet according to another embodiment of the present invention.

FIG. 6 is a front sectional view showing a conventional electromagnet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electromagnet 2 ... Outer case 3 ... Body part 4 ... Protection cap part 4a ... Flange surface 4b ... Rear wall 5, 50 ... Tube assembly 6, 71 ... Bobbin (tube) 6a, 73a ... Rear wall 6b, 73b ... Stopper part 7, 72: coil 9, 75: fixed iron core 11, 77: movable iron core 13: packing 73, pipe

Claims (4)

[Claims] 1. An outer case having one end opened, and a tube assembly housed in the outer case, wherein the tube assembly approaches and separates from a fixed iron core and the fixed iron core. An electromagnet comprising a tube in which a movable iron core and a movable iron core are disposed, wherein the tube is formed of a non-magnetic material, one end of which is opened and the other end is formed of a rear wall. The outer case is formed in a cylindrical shape so as to be closed, and the outer case is disposed on a main body portion of a magnetic body having a mounting flange portion at one end and an opening at the other end, and an inner surface around the opening. A protective cap portion of a magnetic material having a flange surface, and a projection formed to penetrate the opening from the flange surface and project outward to close the inside;
An electromagnet, comprising: 2. The bobbin in which the tube is wound with a coil, wherein the bobbin is formed so as to cover one end and a pair formed outward from an outer peripheral surface. And a flange plate formed outward from one wall portion of the coil storage wall through a gap portion, and a flange plate is formed integrally with the coil storage wall portion. The electromagnet according to claim 1, wherein 3. The electromagnet according to claim 1, wherein the tube is a pipe housed in a bobbin around which a coil is wound. 4. An elastic member for pressing an outer peripheral surface of the protective cap portion is provided between the opening of the outer case and the protective cap portion.
4. The electromagnet according to 2 or 3.