JPS5844579Y2 - solenoid - Google Patents

Description

[Detailed description of the invention] This invention relates to a solenoid that can obtain a large operating force in the middle of its operating stroke.

For example, solenoids are often used to press keys on electric typewriters.

It is desirable for such a solenoid to apply the largest operating force, such as suction force, to the movable iron core at the middle part of the entire stroke, as shown in Figure 1a.For this reason, conventionally, in order to satisfy the above conditions, the entire solenoid suction force is applied to the movable iron core. As shown in Figure 1, a larger version is used.

However, such a solenoid has an extremely large capacity and is economically disadvantageous.

Therefore, as shown in Japanese Utility Model Publication No. 49-7068, first and second plungers are provided to the fixed core as shown in FIG. A device that obtains two-drive operation is being considered.

However, in this case, a considerable amount of magnetic flux passes through during the first stage operating state in which the first plunger is attracted to the fixed core, so that the fixed core and the second plunger are then moved to obtain the second stage operation. The suction force between them will be greatly reduced.

This means that, depending on the load, although the load starts to be driven by the first-stage operation, it becomes unable to respond to this drive at the start of the second-stage operation, making the drive of the load unstable.

This idea was made to solve the above problems, and it is a solenoid that can greatly increase the operating force for obtaining the second stage operation and stably drive the load. The purpose is to provide.

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

In FIG. 2, reference numeral 1 denotes a cylindrical excitation coil wound around a bobbin 2, and a fixed iron core 3 is fitted into one open end of the coil 1.

This fixed iron core 3 has a cylindrical shape, and has, for example, a tapered recess 31 formed at one open end located inside the coil 1, and a stepped portion 32 formed within the hollow portion.

The auxiliary core 4 is movably inserted into the hollow part of the fixed core 3.

The auxiliary iron core 4 has one end formed as a tapered protruding portion 41 that becomes gradually thinner toward the tip, and the other end formed as a large diameter portion 42 that is engaged with the step portion 32.

Further, the auxiliary iron core 4 has a notched groove 43 formed along the circumferential surface between the protruding portion 41 and the large diameter portion 42.

In this case, the width of the cutout groove 43 is made relatively large, and the width of the circumferential surface of the large diameter portion 42 is made as small as possible.

Then, the auxiliary core 4 is biased to the right in the drawing by the spring 5 so that the protruding portion 41 protrudes from one open end of the fixed core 3 and the large diameter portion 42 is locked to the stepped portion 32.

This state is shown in FIG. 2a. In this case, the large diameter portion 42
The locking surfaces of the step portion 32 and the step portion 32 are made sufficiently large to allow good transmission of magnetic flux therebetween.

In addition, 6 in the figure is a spring 5 fitted into the other open end of the fixed iron core 3.
A grip ring, for example, is a stop that absorbs the biasing force.

On the other hand, the movable iron core 7 is inserted from the other open end of the excitation coil 1.

This movable core 7 is brought into contact with the auxiliary core 4 and the fixed core 3, and has an end portion corresponding to the recess 31 of the measurement core 3 formed into a tapered convex portion 71, for example.

In the figure, 8 is a pipe made of a non-magnetic material inserted into the hollow part of the bobbin 2, and 9 is a yoke.

Next, the operation of the solenoid constructed as above will be described.

Now, when the coil 1 is energized in the state shown in FIG. 2a, the movable core 7 moves to the left in the figure along the axial direction of the bobbin 2.
First, it comes into contact with the tip of the auxiliary iron core 4 to complete the first stage operation.

However, from this position, the movable core 7 moves further to the left in the figure together with the auxiliary core 4 against the biasing force of the spring 5, and as shown in FIG.
1 and completes the second stage operation, thereby completing the entire stroke operation.

In this case, the relationship between the suction force acting on the movable iron core 7 and the operating stroke of the entire solenoid is as shown in FIG. 3a.

That is, in the first stage operation until the movable core 7 contacts the auxiliary core 4, the suction force acting on the movable core 7 increases rapidly from just before the movable core 7 attracts the auxiliary core 4.

Then, the movable iron core 7 contacts the auxiliary iron core 4 and starts to move together with the auxiliary iron core 4 against the biasing force of the spring 5.
In the step operation, the suction force acting on the movable core 7 temporarily decreases, and as the tapered convex portion 71 of the movable core 7 approaches the tapered concave portion 31 of the fixed core 3 and the stroke becomes smaller, the suction force increases again.

In this case, when the auxiliary core 4 begins to move leftward in the drawing due to the second stage operation, the large diameter portion 42 of the auxiliary core 4 is disengaged from the stepped portion 32 of the fixed core 3.

Then, the auxiliary core 4 comes into contact with the hollow part of the measuring core 3 only by the circumferential surface of the large diameter part 42 with a small width dimension and part of the tapered protrusion 41 due to the notch groove 43, so that the fixed core 3
The magnetic resistance between the auxiliary iron core 4 and the auxiliary iron core 4 increases, and the magnetic flux passing through the auxiliary iron core 4 decreases.

As a result, the magnetic flux passing through the fixed iron core 3 and reaching the movable iron core 7 increases by the amount that the magnetic flux passing through the auxiliary iron core 4 decreases.
The attraction force between the two will increase as a whole.

As a result, considering the solenoid as a whole, a large suction force can be obtained once in the middle of the operation stroke, and the suction force for obtaining the second stage operation can also be greatly increased. Superior characteristics can be obtained compared to those of a two-stage operating solenoid.

Therefore, with such a configuration, the auxiliary core is movably provided in the hollow part of the cylindrical fixed core, and the movable core is attracted to the auxiliary core and the fixed core in that order, thereby obtaining two-stage operation. In this case, by making the configuration of the auxiliary core and the fixed core as in the above embodiment, when the movable core is always in an open state, the large diameter part of the auxiliary core and the stepped part of the fixed core are locked together during this time. A predetermined attraction force is applied to the first stage operation until the movable core is attracted to the auxiliary core by minimizing the magnetic resistance of the movable core, and the movable core is attracted to the auxiliary core, and in this state, the auxiliary core exerts a biasing force. When moving in the direction against A large suction force is applied during the second stage operation until it is attracted to the fixed iron core.

In other words, with such a configuration, a large suction force can be obtained even in the second stage operation, so that the load started to be driven in the first stage operation can be reliably driven even after the second stage operation. Thereby, load driving can always be performed stably.

This has the advantage that it can be applied to a wide range of loads compared to the conventional second stage operation in which the suction force is significantly reduced.

Furthermore, since it is extremely simple in terms of structure, it is not only easy to assemble, but also inexpensive and economically advantageous.

It should be noted that this invention is not limited to the above-mentioned embodiments, and can be implemented with appropriate modifications without changing the gist.

For example, as shown in FIG.
may be formed.

In this way, since the opposing area between the auxiliary core 4 and the movable core 7 increases, the suction force between them during the first drive operation increases as shown in FIG. 3 compared to that shown in FIG. 2. I can do it.

Other details are the same as in FIG. 2. As described above, according to this invention, the operating force for obtaining the second stage operation can be greatly increased, and a solenoid that can stably drive a load can be provided.

[Brief explanation of the drawing]

Figure 1 shows the suction characteristics of a general solenoid, Figure 2 shows the suction characteristics of a general solenoid.
Figures a and l) show an embodiment of this invention, where a is at the time of return and b
3 is a characteristic diagram for explaining the same embodiment, and FIG. 4 is a longitudinal sectional view showing another embodiment of this invention. 1... Excitation coil, 2... Bobbin, 3
...Fixed core, 31...Tapered recess, 32...Stepped portion, 4...Auxiliary core, 4
1...Tapered protrusion, 42...Large diameter portion, 43...Notch groove, 5...Spring,
6...Clip ring, 7...Movable iron core, 71...Tapered convex portion, 72...
Tapered recess, 8...pipe, 9...
yoke.

Claims (1)

[Scope of utility model registration request] a cylindrical excitation coil; a fixed iron core that is fitted into one open end of the coil, has a cylindrical shape, has four parts formed at the one open end on the inside of the coil, and has a stepped part formed in the hollow part; A tapered protrusion is movably inserted into the hollow part of the fixed iron core, and is formed at one end of the fixed iron core with a tapered protrusion that protrudes outward with a predetermined biasing force from the recess at one open end of the fixed iron core. A large diameter portion is formed to be locked to the stepped portion, and a notched groove is formed between the protruding portion and the large diameter portion, and movement in a direction against the biasing force causes the large diameter portion and the stepped portion of the fixed iron core to be connected to each other. The auxiliary core is released and the magnetic resistance between it and the fixed core can be increased, and the auxiliary core and the fixed core are inserted through the other open end of the excitation coil so that they can be attracted to each other in this order, and the fixed core A solenoid comprising: a movable iron core having a convex end portion that wicks in a recessed portion of the iron core.