CN-122000166-A - Electromagnetic solenoid

Abstract

An electromagnetic solenoid is obtained in which magnetic flux generated between a convex portion and a concave portion in a direction different from the operation direction of a movable iron core can be reduced even when the current passing through a coil is reduced during suction holding. The electromagnetic solenoid has a bobbin made of a non-magnetic material, a fixed core, a movable core, a biasing member, a coil, a driving circuit, and a yoke made of a magnetic material. The movable core has a protruding portion protruding toward the fixed core and a groove portion extending over the entire circumference of the root portion of the protruding portion. The fixed core is formed with a recess opening at an end portion facing the movable core. In a state where the movable core is attracted to the fixed core, the protruding portion is disposed in the recessed portion, and a gap is formed between an outer peripheral surface of the protruding portion and an inner peripheral surface of the recessed portion through the groove portion.

Inventors

• HIDA KAZUHISA

Assignees

• 三菱电机株式会社

Dates

Publication Date

20260508

Application Date

20251103

Priority Date

20241108

Claims (7)

1. 1. An electromagnetic solenoid, comprising: A cylindrical bobbin made of a non-magnetic material; a fixed iron core disposed on an inner periphery of the bobbin; A movable iron core disposed so as to be movable in an axial direction on an inner periphery of the bobbin and opposed to the fixed iron core in the axial direction; a biasing member that biases the movable iron core in a direction away from the fixed iron core; A coil that generates a magnetic force that causes the movable iron core to be attracted toward the fixed iron core against the urging force of the urging member; A driving circuit for making the current flowing through the coil smaller than that in the sucking operation in the state that the movable iron core is sucked to the fixed iron core, and A yoke which houses the bobbin, the fixed core, the movable core, the biasing member, and the coil and is made of a magnet material, The movable core has a protrusion protruding toward the fixed core and a groove extending over the entire circumference around the root of the protrusion, A recess opening toward an end of the movable core in the fixed core is formed in the fixed core, The protruding portion is disposed in the recessed portion in a state where the movable core is adsorbed to the fixed core, and a1 st gap is formed between an outer peripheral surface of the protruding portion and an inner peripheral surface of the recessed portion through the groove portion.
2. 2. The electromagnetic solenoid according to claim 1, wherein, A 2 nd gap is formed between the outer peripheral surface of the convex portion and the inner peripheral surface of the concave portion at a position closer to the tip end of the convex portion than the 1 st gap.
3. 3. The electromagnetic solenoid according to claim 2, wherein, The 1 st gap and the 2 nd gap communicate with each other and are connected in the axial direction.
4. 4. An electromagnetic solenoid according to any one of claims 1 to 3 wherein, And a tubular member disposed between the bobbin and the movable core in the yoke and fixed to an inner peripheral surface of the bobbin, An annular step portion protruding toward the inner periphery is formed on the inner peripheral surface of the bobbin, A cylindrical member-side tapered portion that reduces in diameter in the axial direction toward the fixed core is formed on an outer peripheral surface of an end portion of the cylindrical member toward the fixed core, A3 rd gap is formed between the cylindrical member-side tapered portion and the annular stepped portion.
5. 5. The electromagnetic solenoid according to claim 4, wherein, The 3 rd gap is formed over the entire circumference of the fixed core.
6. 6. An electromagnetic solenoid according to any one of claims 1 to 3 wherein, And a tubular member disposed between the bobbin and the movable core in the yoke and fixed to an inner peripheral surface of the bobbin, An annular step portion protruding toward the inner periphery is formed on the inner peripheral surface of the bobbin, A reluctance portion that blocks a flow of magnetic flux from the tubular member to the annular step portion is formed between an end portion of the tubular member facing the fixed core direction and the annular step portion.
7. 7. The electromagnetic solenoid according to claim 6, wherein, The reluctance portion is a gap formed between an end of the tubular member in the direction toward the fixed core and the annular step portion, or a nonmagnetic body formed of a nonmagnetic material and disposed between an end of the tubular member in the direction toward the fixed core and the annular step portion.

Description

Electromagnetic solenoid Technical Field The present invention relates to an electromagnetic solenoid having a fixed iron core and a movable iron core. Background Conventionally, an electromagnetic solenoid having a fixed iron core and a movable iron core, which are disposed opposite to each other in an axial direction, is known. As such an electromagnetic solenoid, for example, techniques disclosed in patent documents 1 and 2 are known. Patent document 1 discloses a technique in which, in order to increase the suction force at the time of suction operation of the movable iron core to the fixed iron core, a convex portion is provided at the center portion in the radial direction of the movable iron core, a concave portion is provided at the center portion in the radial direction of the fixed iron core, and the convex portion is disposed in the concave portion at the time of suction operation. In the case of the attraction holding for holding the movable iron core attracted to the fixed iron core, that is, the movable iron core is in contact with the fixed iron core, the attraction force is larger than that in the attraction operation, so that the movable iron core can be maintained in the state of being attracted to the fixed iron core even if the ampere-turns number of the electromagnetic solenoid is reduced. Accordingly, patent document 2 discloses a technique of reducing heat generation of the electromagnetic solenoid by making a current flowing through the coil smaller during suction holding than during suction operation. Patent document 1 Japanese patent laid-open No. 4-192401 Patent document 2 Japanese patent application laid-open No. 2004-186052 As in the technique disclosed in patent document 1, providing a convex portion in the movable core and providing a concave portion in the fixed core is effective for increasing the adsorption force at the time of the adsorption operation. However, in the technique disclosed in patent document 1, if the current passing through the coil is reduced at the time of suction holding as in the technique disclosed in patent document 2, a lot of magnetic flux is easily generated between the convex portion and the concave portion in a direction different from the operation direction of the movable core. This causes a problem that the adsorption force for adsorbing the movable core to the fixed core is reduced. Disclosure of Invention The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an electromagnetic solenoid capable of reducing magnetic flux generated between a convex portion and a concave portion in a direction different from an operation direction of a movable iron core, as compared with the conventional art, even when a current passing through a coil is reduced at the time of suction holding. In order to solve the above problems, an electromagnetic solenoid according to the present invention includes a tubular bobbin made of a non-magnetic material, a fixed iron core disposed on an inner periphery of the bobbin, a movable iron core disposed so as to be movable in an axial direction on the inner periphery of the bobbin and facing the fixed iron core in the axial direction, and a biasing member for biasing the movable iron core in a direction away from the fixed iron core. The electromagnetic solenoid according to the present invention includes a coil that generates a magnetic force that causes the movable core to be attracted to the fixed core against the urging force of the urging member, a drive circuit that causes a current flowing through the coil to be smaller than that during the attraction operation in a state in which the movable core is attracted to the fixed core, and a yoke that accommodates the bobbin, the fixed core, the movable core, the urging member, and the coil and is made of a magnet material. The movable core has a protruding portion protruding toward the fixed core and a groove portion extending over the entire circumference of the root portion of the protruding portion. The fixed core is formed with a recess opening toward an end of the movable core. In a state where the movable core is attracted to the fixed core, the convex portion is disposed in the concave portion, and a 1 st gap is formed between an outer peripheral surface of the convex portion and an inner peripheral surface of the concave portion through the groove portion. ADVANTAGEOUS EFFECTS OF INVENTION The electromagnetic solenoid according to the present invention has an effect that, even when the current passing through the coil is reduced during the attraction holding, the magnetic flux generated between the convex portion and the concave portion in a direction different from the operation direction of the movable core can be reduced as compared with the conventional art. Drawings Fig. 1 is a cross-sectional view showing a state of the electromagnetic solenoid according to embodiment 1 when the elect