JPH0325313Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is designed to be used, for example, to drive a pair of operating pieces constituting a friction brake in order to stop a pair of tape reel stands provided in a video tape recorder. The present invention relates to an operation piece drive device using a solenoid plunger.

[Background technology and its problems]

Conventionally, solenoid plungers have been widely used as mechanical drive sources for various electronic devices. This solenoid plunger has a solenoid provided in a solenoid box, and a plunger rod with one end protruding from the solenoid box disposed within the solenoid. It operates to draw suction into the solenoid box.

By the way, the suction force of this solenoid plunger changes as shown in the characteristic diagram shown in FIG. 1 with respect to the amount of protrusion of the plunger rod from the solenoid box. That is, in this characteristic diagram, the vertical axis indicates the suction force of the plunger rod,
The horizontal axis indicates the amount of protrusion of the plunger rod from the solenoid box. The above plunger rod has a solenoid plunger performance curve A.
As shown in the figure, when the plunger rod protrudes beyond the solenoid box, the displacement force applied by the solenoid, that is, the suction force, acts small, and as it is drawn into the solenoid box, the suction force that acts on the plunger rod has an approximately square relationship. rises with Therefore, in a solenoid plunger having such characteristics, the suction force is weak when the plunger rod protrudes beyond the solenoid box, and it can only be driven against a load that is less than the suction force. Therefore, when attempting to obtain a large stroke of the plunger, the solenoid plunger can only be used for driving something that has a small load relative to its capacity. For example, when such a solenoid plunger drives an operating piece biased by a coil spring, as shown by load curve B, the product kx of the spring constant k of the spring and the displacement x is equal to This will act as a load. The stroke of the solenoid plunger must be set within a range where its suction force exceeds the load kx. Therefore, if the load applied to the solenoid plunger is relatively large relative to its capacity, it is difficult to increase its stroke.

However, when the amount of protrusion of the plunger rod is reduced, the suction force becomes extremely large, and an unnecessarily large suction force acts on all parts except for a portion intended to counter the load.

In this way, it is difficult to obtain a large stroke with a solenoid plunger, and it is also difficult to use the suction force effectively over the entire stroke. It becomes necessary to use .

In addition, in such a solenoid plunger,
The plunger rod is returned to the protruding position before the suction operation after the solenoid is energized by the biasing force of a coil spring or the like that biases the operating piece. However, due to long-term use of the solenoid plunger, the plunger rod becomes magnetized, and a residual attractive force is generated after the energization is stopped, which may prevent proper return operation. Therefore, it is necessary to increase the return force of the plunger rod by the coil spring, that is, the load kx, but if the stroke of the plunger rod is increased, the load kx cannot be large relative to the capacity of the solenoid plunger as described above. Therefore, it is difficult to ensure proper return operation. Therefore, a separate coil spring is required to ensure the return of the plunger rod, which has the drawback of increasing the number of parts and complicating the installation work.

[Purpose of invention]

Therefore, in view of the above-mentioned circumstances, the present invention makes it possible to effectively use the suction force of the solenoid plunger in accordance with its characteristics, to obtain a large stroke relative to its capacity, and to obtain a reliable return operation. An object of the present invention is to provide an operation piece drive device using a solenoid plunger that can perform the following operations.

[Summary of the idea]

That is, in order to achieve the above-mentioned object, the present invention provides a pair of operation pieces that are each rotatably supported and engaged with each other, and these operation pieces are biased to rotate in opposite directions by at least one spring. At the same time, a solenoid plunger is provided which overcomes this rotational bias and drives each operation piece by suction, and as the suction operation of the solenoid plunger moves, the engagement point of each of the operation pieces moves, and the amount of rotation is determined by the amount of rotation of the solenoid plunger. It is designed to increase relative to the amount of drive.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

In this embodiment, as shown in FIG. 2, the operation piece drive device according to the present invention includes a pair of tape reels rotatably supported by a mechanical chassis 1 of a video tape recorder and driven by a drive mechanism (not shown). This is provided as a brake device to stop the platforms 2 and 3. A reel hub of a tape cassette (not shown) is fitted into each of the above-mentioned tape reel stands 2 and 3, and the magnetic tape stored therein is made to run by the rotational drive of each of the above-mentioned tape reel stands 2 and 3. There is.

And, the solenoid plunger 4 according to the present invention
The operating piece drive device is the tape reel stand 2,
A pair of operation pieces 5 and 6 that are operated toward and away from 3.
, a solenoid plunger 4 that drives these operating pieces 5 and 6, and one coil spring that biases these operating pieces 5 and 6.

Each of the operating pieces 5 and 6 is integrally formed of, for example, synthetic resin, and is attached to a pair of support shafts 5 provided on the mechanical chassis 1 by outsert molding.
It is rotatably supported by shafts a and 6a. and,
These operating pieces 5, 6 are formed with pressure contact portions 7, 8 which press against the outer circumferential wall of the proximal end of each of the tape reel stands 2, 3 and stop the rotation of these tape reel stands 2, 3. Incidentally, the pressure contact portions 7 and 8 are provided with friction rubber or the like in order to obtain a large frictional force.

Further, these operating pieces 5 and 6 are provided with engagement arm portions 9 and 10 that engage with each other. For example, as shown in the figure, these engaging arm parts 9 and 10 are connected to one engaging arm part 9 and the other engaging arm part 10.
A pair of protrusions 11 and 12 are formed facing each other, and depending on the rotation angle of each of the operating pieces 5 and 6,
When one protrusion 11 or the other protrusion 12 comes into contact with the other engagement arm part 10,
The operating pieces 5 and 6 are placed in an engaged state, and as one operating piece 5 rotates, the other operating piece 6 is rotated. In the pair of operation pieces 5, 6 formed in this way, the pair of protrusions 11,
12, when one protrusion 11 formed on the inner diameter side of one operating piece 5 and the other engaging arm 10 are in contact with each other, the rotation of one operating piece 5 does not allow the operation of the other operating piece 5. The piece 6 is adapted to rotate slightly, and when the other protrusion 12 formed on the outer diameter side of the operating piece 5 is engaged with the other engaging arm 10, the one operating piece 5 rotates. The other operating piece 6 is designed to rotate significantly relative to the rotation. In this manner, the mutual engagement points of the operating pieces 5 and 6 move as the operating pieces 5 and 6 rotate, and the amount of rotation changes with respect to a constant amount of drive.

Further, a single coil spring 13 is bridged between each of the operating pieces 5 and 6. This coil spring 13 connects each of the operating pieces 5 and 6 to each of the projections 1 and 13.
1 and 12 and the other engaging arm 10 toward and away from each other, that is, these operating pieces 5 and 6 are rotated in opposite directions. The pressure contact portions 7 and 8 of each of the operation pieces 5 and 6 are brought into pressure contact with the tape reel stands 2 and 3 by the biasing force of the coil spring 13. Furthermore, the coil spring 1
3 also acts as a spring to return the plunger rod 14 to the protruding state before the suction operation after the suction operation of the solenoid plunger 4 is canceled.

The solenoid plunger 4 is attached to the mechanical chassis 1, and its plunger rod 14 is attached to one of the operating pieces 5 to rotate the operating piece 5.

Solenoid plunger 4 configured in this way
In the operating piece drive device according to the invention, when the solenoid plunger 4 is not energized, the plunger rod 14 protrudes more than the solenoid box 15, as shown in FIG. The pressure contact parts 7, 8 are in pressure contact with the tape reel stands 2, 3,
The rotation is stopped. and,
When the solenoid plunger 4 is energized, the plunger rod 14 moves as shown in FIGS.
It is driven by suction as shown in the figure. At this time, as long as the amount of protrusion of the plunger rod 14 is large,
As shown in FIG. 3, the operating pieces 5 and 6 are engaged at the engagement point between the protrusion 11 on one side and the engagement arm 10 on the other side, and the coil spring 13 is used to prevent the plunger rod 14 from retracting. Stretched by a relatively small percentage of the amount. Therefore, the load applied to the plunger rod 14 in this state is also small.

Then, when the amount of protrusion of the plunger rod 14 becomes smaller, as shown in FIG. Above coil spring 1
3 is expanded to a large extent relative to the amount by which the plunger rod 14 is retracted. Therefore, a relatively large load is applied to the plunger rod 14, but the plunger rod 1 at this position
The suction force of No. 4 has increased significantly, and proper suction drive is performed against the above-mentioned load. In this way, each of the operation pieces 5 and 6 is rotated, each of the pressure contact parts 7 and 8 is operated to be separated from each of the tape reel stands 2 and 3, and the drive operation of the tape reel stands 2 and 3 is performed. It is done. By providing the other protrusion 12, each operating piece 5, 6 can be rotated by the amount of rotation α compared to when only one protrusion 1 is provided.

The relationship between the performance of the solenoid plunger 4 and the load applied to the plunger rod 14 in such an operation piece drive device is explained as a characteristic diagram shown in FIG. That is, in this characteristic diagram, the vertical axis represents the suction force of the plunger rod 14, and the horizontal axis represents the amount of protrusion of the plunger rod 14. And the plunger rod 14
As shown by the performance curve C of the solenoid plunger 4, the load curve D increases according to the amount of retraction of the plunger rod 14, and the load curve D due to the coil spring 13 is shown by the performance curve C of the solenoid plunger 4. From the combined position, the above performance curve A
The suction force of the solenoid plunger 4 is effectively used.

In this way, the solenoid plunger 4 of this embodiment
According to the operating piece driving device according to
When the engagement point of the plunger rod 14 moves and the amount of protrusion of the plunger rod 14 is large, a small load is applied to the plunger rod 14, and when the amount of protrusion becomes small, a large load is applied to the plunger rod 14, thereby increasing the suction. Since the operating pieces 5 and 6 are moved largely at the position where the force increases, a large stroke can be obtained relative to the capacity of the solenoid plunger 4, and the amount of rotation of each operating piece 5 and 6 is large. can be obtained. Therefore, the press-contact parts 7, 8 provided on each of the operating pieces 5, 6 can be operated properly, and malfunctions of the tape reel stands 2, 3 can be prevented.

In addition, since the amount of rotation of each of the operating pieces 5 and 6 can be increased, the mounting position of the solenoid plunger 4 and the like must be strictly adjusted in order to ensure proper braking operation of the tape reel stands 2 and 3. There's no need to. Therefore, the work of assembling a video tape recorder provided with this operating piece driving device can also be facilitated.

Furthermore, with the plunger rod 14 retracted into the solenoid box 15, a large load is applied to the plunger rod 14 by the coil spring 13. Therefore, when the solenoid plunger 4 is no longer energized, this load acts as a return force for the plunger rod 14 and can reliably return the plunger rod 14 to its protruding state. Therefore, malfunction due to residual suction force of the plunger rod 14 is prevented.

Note that the above-described embodiment can be modified in various ways. For example, the projections 11 and 12 may be provided on the other engagement arm 10. In addition, the coil spring 1
3 may be arranged, and each operation piece 5, 6 may be individually biased. Furthermore, it is also possible to apply a friction brake when the solenoid plunger 4 is energized.

Furthermore, the present invention is not limited to the above-described embodiments, and, for example, the operation pieces 5 and 6 are provided with pressure contact parts 7,
By providing an operating lever or the like in place of 8, the present invention can be applied to various applications as a driving device for operating pieces provided in various electronic devices.

[Effect of idea]

As is clear from the description of the embodiments described above, according to the present invention, the engagement point of each operating piece moves as the solenoid plunger suctions, and at a position where the plunger rod protrudes a large amount, a small load is applied to the plunger rod. When the amount of protrusion becomes small, a large load is applied to the plunger rod, and the operation piece is moved greatly at the position where the suction force is increased, so that the solenoid plunger has a large capacity relative to the capacity of the solenoid plunger. A stroke can be obtained, and a large amount of rotation of each of the operation pieces can be obtained.

Further, when the plunger rod is retracted into the solenoid box, a large load is applied to the plunger rod by the coil spring.
Therefore, when the solenoid plunger is no longer energized, this load acts as a return force for the plunger rod, and can reliably return the plunger rod to its protruding state. Therefore, malfunction due to residual suction force of the plunger rod is prevented.

[Brief explanation of the drawing]

Fig. 1 is a characteristic diagram illustrating the characteristics of the solenoid plunger and the state of the load applied to the solenoid plunger, Fig. 2 is a schematic plan view showing an embodiment of the present invention, and Fig. 3 is a pair of driven solenoid plungers. 4 is a schematic plan view showing a state in which the engagement point of the operating piece moves, FIG. 4 is a schematic plan view showing a state in which the retracting operation of the plunger rod of the solenoid plunger is completed, and FIG. 5 shows the performance of the solenoid plunger in the above embodiment. FIG. 3 is a characteristic diagram illustrating the state of the load applied to the solenoid plunger. 4... Solenoid plunger, 5, 6... Operating piece, 9, 10... Engagement arm, 11, 12... Protrusion, 13... Coil spring.

Claims (1)

[Scope of utility model registration request] A pair of operation pieces are provided which are rotatably supported and engaged with each other, and the operation pieces are biased to rotate in opposite directions by at least one spring, and each operation piece is rotated by overcoming this rotation biasing force. Operation by the solenoid plunger is provided with a solenoid plunger that is driven by suction, and the engagement points of the respective operation pieces move as the solenoid plunger suctions, and the amount of rotation thereof becomes larger than the amount of drive of the solenoid plunger. Single drive device.