JPH0140167Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to solenoids.

Generally, in a DC solenoid, a suction coil and a holding coil are wound around a bobbin, and a switching contact that operates during the plunger suction stroke switches the connection of each coil to the power source to reduce the coil current in the plunger holding state. A coil switching type solenoid is often used to reduce power consumption and suppress coil temperature rise. However, in the past, a separate switch was attached to the outside of the yoke of the solenoid as a switching contact, and the switching switch was operated by pushing a rod passing through the yoke and a fixed core fixed to the yoke with a plunger, etc. The disadvantage was that the external dimensions were large and the installation space for the solenoid was large.

This idea solves the above-mentioned conventional drawbacks.
The purpose is to provide a small and compact coil switching type solenoid.

An embodiment of this invention will be described below with reference to the drawings.

In the figure, 1 is a bobbin having a through hole 2, a suction coil 3a and a holding coil 3b connected in series with the suction coil 3a.
A coil 3 consisting of the following is wound. Reference numeral 5 denotes a yoke surrounding the bobbin 1, which is composed of a frame 6 formed by bending a magnetic material plate into a U-shape, and a lid 7 made of a magnetic material plate caulked to the frame. A molding resin is injected between the yoke 5 and the outer circumference of the bobbin 1 around which the coil 3 is wound, and solidifies to form a resin layer 8.
is formed. Reference numeral 9 denotes a fixed iron core that is inserted into one end of the through hole 2 and fixed to the frame 6 in a protruding manner. Reference numeral 11 denotes a plunger which is partially inserted into the through hole 2 and whose insertion side end 12 can freely approach and separate from the fixed iron core 9. 15 is formed, and a ring 16 made of a magnetic material is slidably fitted into this small diameter portion. Reference numeral 17 indicates a pin for preventing the ring from coming off, which is embedded in the plunger 11, and reference numeral 18 indicates an elastic body, such as a sponge, inserted between this pin and the ring 16, to suppress vibrations of the ring 16 during movement of the plunger, etc.
This is to prevent friction and noise from coming into contact with various parts due to the vibration. The protruding end portion 13 of the plunger is connected to a controlled body (not shown),
19 is a hole for this connection.

On the other hand, the collar 21 on the plunger insertion side of bobbin 1
has a thick and irregular shape, and a holding plate 24 to which a fixed contact 23 is fixed is fixed to the outwardly protruding portion 22 . Further, the collar 21 is formed with an elongated cavity 25 that opens to the outside, and a movable contact 27 facing the fixed contact 23 is fixed to a support piece 26 made of an elastic material whose base is fixed to the bottom of the cavity. These contacts 23 and 27 form a switching contact 28. This switching contact 28 is connected in parallel to the holding coil 3b as shown in the fourth figure.
Terminals 30 and 31 are connected to the ends of each coil, and are fixed to the other collar 32 of the bobbin 1.
The connection ends 33 and 34 of the holding plate 24 and the support piece 26 of both contacts protrude outward from the collar 21, and are connected to each coil or each terminal 30, 31.
It is fixed and held buried in the resin layer 8 together with the lead wire connecting it. Reference numeral 36 denotes a push rod made of an insulating material and having a stepped short shaft, one end of which faces the side surface of the ring 16 on the step 14 side, and the other end of which faces the intermediate portion of the support piece 26. Part 2
It is slidably inserted into a stepped hole-shaped through hole 37 bored in the side wall portion of 5. A small-diameter projection 38 is projected from the tip of the large-diameter portion of the push rod 36, and this projection is inserted into a small hole bored in the support piece 26.

In the solenoid 40 having the above configuration, when the coil is de-energized, the plunger 11 is in the position shown in the figure, and the ring 16 is in a position apart from the lid 7 together with the plunger 11, so the switching contact 28 is closed. If power is supplied to the terminals 30 and 31, the holding coil 3
Since b is short-circuited at the switching contact 28, a large current flows through the attraction coil 3a, and the plunger 11 is attracted in the direction of arrow X. At the same time, the ring 16 also moves in the direction of arrow X, and at the end of the attraction stroke, the push rod 36 is pressed, thereby opening the switching contact 28 and switching the attraction coil 3a and the holding coil 3b connected in series to the holding coil 3b to a holding state in which a small current flows. Since the ring 16 is sucked into the lid 7 at the end of the suction stroke, the plunger 1
1 increases, and a predetermined contact distance is reliably formed between the fixed contact 23 and the movable contact 27 while the ring 16 is attracted to the lid 7. The stepped portion 14 of the plunger is located slightly inside the surface of the lid 7, and the ring 16 is attracted to the surface of the lid 7. When the plunger 11 protrudes due to power cut-off of the coil, the support piece 2
6 returns the switching contact 28 to the closed state.

This invention is not limited to the above embodiment, and for example, a holding coil 3b and an attraction coil 3a are connected in parallel, and a switching contact 28 is connected to this attraction coil.
are connected in series, and in the holding state, the holding coil 3b
It is also possible to use a coil with a switching method other than the above, such as holding the plunger with only the plunger.

Above, we have explained the case where this idea is applied to an integral molded solenoid.
This idea can also be applied to solenoids that are not integrally molded.

As explained above, according to this invention, a fixed contact and a movable contact are provided on the flange of the bobbin on the side where the plunger is inserted, and a ring made of a magnetic material is slidably inserted into the protruding end of the plunger. Since the movable contact is driven by the movable contact, a coil switching solenoid having a small and compact structure can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view of a solenoid showing an embodiment of this invention, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, and Fig. 3 is a sectional view taken along the line B-B in Fig. 2. FIG. 4 is also a wiring diagram. 1... Bobbin, 3a... Suction coil, 3b...
Holding coil, 11... Plunger, 13... Projecting side end, 14... Step part, 15... Small diameter part, 16...
...Ring, 21...Brim, 23...Fixed contact, 2
6... Support piece, 27... Movable contact, 28... Switching contact, 36... Push rod, 37... Through hole, 40...
…solenoid.

Claims (1)

[Scope of utility model registration request] A bobbin having a through hole around which a suction coil and a holding coil are wound, a yoke surrounding the bobbin, a plunger partially inserted into the through hole, and a bobbin that operates during the suction stroke of the plunger to provide the above A solenoid comprising an attraction coil and a switching contact for switching the connection state of the holding coil to a power source, wherein a fixed contact is fixed to a brim of the bobbin on the side where the plunger is inserted, and a support piece having a base fixed to the brim is provided. A movable contact opposite to the fixed contact is fixed to form the switching contact, a small diameter part is provided at the protruding end of the plunger via a step, and a ring made of a magnetic material is attached to the small diameter part of the plunger. A push rod is slidably inserted in the axial direction, and has one end facing the step side of the ring and the other end facing the support piece, and is slidable into the hole drilled in the yoke and the collar. A solenoid characterized by being fitted into the.