JPH0782679B2 - Operation switching mechanism in tape recorder - Google Patents

Description

The present invention relates to an operation switching mechanism applied to switching between various modes in a tape recorder.

[Outline of Invention]

The present invention provides a cam gear having at least two magnets integrally magnetized and a cam integrally provided with a toothless portion, and an attraction type electromagnetic plunger having an iron core facing one pole of the magnet.
An operation switching mechanism in a tape recorder, which has a cam gear and a drive gear meshed with each other, and is configured to perform operation switching drive and operation holding of the tape recorder by rotation and stop holding of the cam gear by forward and reverse energization of an electromagnetic plunger.

[Conventional technology]

A conventional operation switching mechanism using an electromagnetic plunger in a tape recorder is disclosed in Japanese Patent Laid-Open No. 58-70448 (FIG. 5 in the publication). As shown in FIG. 5, this operation switching mechanism has a partly toothless gear (1) with a south pole and a north pole of 180 °.
Is integrally provided with a magnet (2) and a fan-shaped cam (3) which are magnetized so as to face each other, and a drive gear (4) is axially supported so as to face the toothless gear (1). .

An electromagnetic plunger (5) is arranged corresponding to the toothless gear (1). The yoke (6) of this electromagnetic plunger (5) is formed in a double U-shape to form a first magnetic path and a second yoke forming a first magnetic path (7) and a second magnetic path.
Of the first yoke portion (7) is integrally provided with the yoke portion (8) of the first yoke portion (7), and the coil (9) is wound around the common portion of the both yoke portions (7) and (8). (7a) and (7b) are bent toward the center of the magnet (2) of the tooth-missing gear (1) to bring one end (7a) close to the magnet (2) and the other end. Predetermined clearances a ₁ and a ₂ (a ₁ <a ₂ ) are formed in correspondence with each other (7b) in a separated state, and the movable iron core (10) of this electromagnetic plunger (5) is The yoke portion (8) is arranged so as to face each other between both ends (8a) and (8b).

The switching lever (12) connected to the controlled member (11) is engaged with the cam (3) of the toothless gear (1) configured as described above, and the movable iron core (10) of the electromagnetic plunger (5) is also engaged. ) Is connected to the lock lever (13).

In the switching mechanism having this configuration, when the tape recorder is in the stop mode, the tooth-chipped gear (1) faces the drive gear (4) at the tooth-chipped portion (1a) and is in a non-meshing state. 2) is attracted to one end portion (7a) of the first yoke portion (7) of the electromagnetic plunger (5) and is stable. When the FWD button is pressed in this state, the coil (9) of the electromagnetic plunger (5) is energized, and the N pole and S pole are provided at both ends (7a) and (7b) of the first yoke portion (7). Appearing, this magnetic pole causes attraction and repulsive force between the magnet (2) of the toothless gear (1) and rotational force is generated in the toothless gear (1) to mesh with the drive gear (4). Therefore, the partly tooth-missing gear (1) is rotated and the switching lever (12) engaged with the cam (3) is swung so that the controlled member (11) is switched to the switching operation, that is, the FWD mode.

[Problems to be solved by the invention]

In the conventional operation switching mechanism configured as above, the initial rotation (trigger operation) of the tooth-missing gear (1) due to energization of the electromagnetic plunger (5) is determined by the mounting position of the electromagnetic plunger (5) with respect to the tooth-missing gear (1). And the clearances a ₁ and a ₂ between the magnet (2) provided on the toothless gear (1) and the end portions (7a) and (7b) of the first yoke portion (7) vary due to variations in component dimensions. Occurs, and an unstable operation, for example, even if only the operation holding by the attraction force of the electromagnetic plunger (5) is required, the trigger operation is performed and the operation is affected. Therefore, it is necessary to check and adjust the clearance after the electromagnetic plunger (5) is attached, which is a troublesome assembling process.

Further, in the case of holding the operation by the electromagnetic plunger (5) from the trigger operation of the partly tooth-missing gear (1), a stopper is required to prevent the second part of the partly tooth-missing gear (1) from triggering operation, and the structure becomes complicated and the design There is a problem that causes the above restrictions and noise generation.

In view of such a point, the present invention provides an operation switching mechanism that is reliably operated with a simple configuration.

[Means for solving problems]

In order to solve the above-mentioned problem, the present invention provides an operation switching mechanism, a cam gear having a toothless portion and a cam portion, and a magnet having at least two poles magnetized integrally with the cam gear, From an attraction type electromagnetic plunger having an iron core facing one pole of this magnet, a drive gear rotated at a position facing the toothless portion of the cam gear, and a switching lever engaged with the cam portion of the cam gear. It is composed.

[Action]

With this configuration, the cam gear is rotated by the repulsive force of the iron core magnet when the attraction type electromagnetic plunger is energized, and the cam gear is rotated by being meshed with the drive gear, and the switching lever engaged with the cam portion is displaced. Then, the controlled member is operated, the cam gear is stopped and held by the attraction force of the iron core with respect to the magnet when the electromagnetic plunger is reversely energized, and the movable iron core of the electromagnetic plunger is attracted.

〔Example〕

An embodiment in which the present invention is applied to a mode switching mechanism of a tape recorder will be described below with reference to FIGS. 1 to 3. In the figure, (21) is a cam gear, which has an arcuate cam portion (22) formed in the outer peripheral direction from the center portion on one surface, and has a notched tooth portion (23) in a part of the outer peripheral tooth portion. And is rotatably supported by a rotation shaft (24) that is provided so as to project from the center of the chassis. The cam gear (21) is embedded with magnets (25) whose N and S poles are two-sided magnetized, and is exposed on at least the other surface side. (26) is the cam gear (21)
In the present embodiment, a drive force transmission gear (hereinafter referred to as a drive gear) arranged in correspondence with the gear is engaged with a gear (29) fixed to a flywheel (28) of a capstan (27) and is constantly rotated.

(30) is an electromagnetic plunger (hereinafter referred to as an electromagnet), and the iron core is composed of a fixed iron core (31) forming a magnetic path and a stable iron core (32) having a magnetic pole at its tip. The iron cores (31) and (32) are formed in a U shape so that both iron cores (31)
And (32) face each other so that one side (31a) and (32
Insert a) into the bobbin (34) wound with the coil (33),
Attach the other side (32b) of the stable iron core (32) to the coil bobbin (34).
Is extended through the outside of the coil, and a magnetic pole is generated at the tip (32b ₁ ) by energizing the coil (33). The stable iron core (32) is formed of a relatively thin plate-like body, and the tip (32b ₁ ) of the other side portion (32b) is formed in a bifurcated shape. Further, both ends (31a ₁ ) and (31
The movable iron core (35) is arranged so that it can be moved toward and away from b ₁ ).

The electromagnet (30) configured in this manner is arranged in the vicinity of the cam gear (21), and the tip of the other side of the stable iron core (32) (hereinafter simply referred to as the tip) (32b ₁ ) is flat on the magnet (25). They are vertically opposed to each other at a required interval.

In FIG. 3, (36) is an example of the switching lever, FWD / RE
With the V switching lever, one end side (36a) of which is the cam gear (2
It is slidably arranged so as to come into contact with the cam portion (22) of 1), and the tension coil spring (37) makes one direction, that is, one end side portion (36a) comes into contact with the cam portion (22). Is urged to. An operation lever (38) for half-rotating a rotary magnetic head, which is a controlled member, for the switching lever (36) and for switching the tape running direction between the forward (FWD) side and the reverse (REV) side. Etc. are related. The operation lever (38) slides along with the sliding movement of the switching lever (36), and the switching lever (36) moves to the cam gear (21).
When sliding due to the rotation of the lock member (3
It is locked by 9) and the switching lever (36) is also locked.

Reference numeral (40) is a lock lever, which is pivotally supported by a fulcrum shaft (41) and is biased by an extension coil spring (42) in a direction of an arrow, and a movable iron core (3) is attached to the lock lever (40).
5) is swingably supported by the support pin (43). Incidentally, FIG. 4 shows the transport of the reverse type tape recorder to which the operation switching mechanism of the present invention is applied.
4) is a rotary magnetic head and a semi-rotating mechanism (45) at the rear
Is provided, and the operation lever (38) described above is associated with the half-rotation mechanism (45). (46) and (47) are FWD capstans and REV capstans, (48) and (49) are pinch rollers corresponding to the respective capstans (46) and (47), (50) and (51). Is driven by the Rehab drive shaft in the forward and reverse directions. (52) is a mounting plate for the tape select detection switch (53) which also serves as a tape cassette retainer.

Next, the mode switching operation by the operation switching mechanism configured as described above will be described.

First, when the tape recorder is in the STOP mode and the power is not supplied, the capstan (27) is not rotated and therefore the drive gear (26) meshed with the gear (29) on the flywheel (28) side. Has been stopped. In this state, as shown in FIGS. 1 and 3, the cam gear (21) faces the drive gear (26) by the toothless portion (23) and both gears (21) and (26) are disengaged. In this state, the cam gear (21) is attracted by the N pole of the magnet (25) embedded therein facing the tip (32b ₁ ) of the stable iron core (32) of the electromagnet (30). Is stable by. That is, the cam gear (21) is magnetically locked.

Next, when the power switch of the tape recorder is turned on and the capstan (27) is rotated by the motor, the drive gear (2
6) is also rotated in the direction of arrow a in FIG. 1 via the gear (29). By pressing the play button of the tape recorder in this state, the stable iron core (32) is attached to the coil (33) of the electromagnet (30).
Energize in the direction where the N pole is generated at the tip of the (32b ₁ ) (positive energization)
Then, the cam gear (21) is in a state in which the N pole of the magnet (25) repels and the S pole is attracted, and the cam gear (21) rotates in the direction of the arrow b, and the toothed portion meshes with the drive gear (26). The cam gear (21) rotates once by the rotation of the drive gear (26).

At this time, the mode switching lever (36) is slid against the urging force of the tension coil spring (37) by the cam portion (22) of the cam gear (21), and the operation lever (38) and the like associated therewith are driven. Then, a required operation, for example, switching of the magnetic head and FWD / REV in the tape running direction is performed.

If the cam gear (21) rotated in this way has the current supplied to it at this time, the N pole of the magnet (25) will once again become a stable iron core (3).
It is sucked corresponding to the tip (32b ₁ ) of 2) and becomes stable again (trigger operation).

When the coil (33) of the electromagnet (30) is reversely energized, an S pole is generated at the tip (32b ₁ ) of the stable iron core (32). This tip (32b ₁ ) is the magnet of the cam gear (21). N of (25)
Since the poles are facing each other, the cam gear (21) remains in a stable state as they are attracted to each other, and only the attraction force between the fixed iron core (31) and the movable iron core (35) acts to move the movable iron core. The lock lever (40) connected to (35) is fixedly held, and is used only as a motion holding function of a motion member.

As described above, according to this example, when the coil of the electromagnet (30) is positively energized, the trigger operation is performed, and the reverse energization causes the operation holding state. Therefore, when the trigger operation is the adsorption holding operation, the positive energization is changed to the reverse energization. By changing the energizing direction, the mechanical holding mechanism becomes unnecessary.

In this way, one electromagnet can be used as two independent functions by dividing the functions by applying forward and reverse currents to the coil of the electromagnet (30). Further, in this example, the magnet (25) of the cam gear (21) and the tip (32b ₁ ) of the stable iron core (21) of the electromagnet (30) are configured to face each other, so that the clearance between them is set to the electromagnet (30 ) Can be easily and accurately set by adjusting the thrust direction of the cam gear (21) without being affected by variations in the mounting position of ().

Although the magnetic head of the tape recorder and the FWD / REV switching operation in the tape running direction have been described in this example, the switching lever (36) engaged with the cam portion (22) of the cam gear (21).
Can be applied to the switching of various modes by connecting to the controlled member of various switching mechanisms. Also this cam gear (21)
The switching mechanism including the electromagnet (30) and the electromagnet (30) can be applied as a switching mechanism for various devices other than the recording / reproducing device such as a tape recorder.

〔The invention's effect〕

As described above, according to the present invention, one iron core of the electromagnetic plunger also serves as the trigger function and the stabilizing function of the cam gear that performs the trigger operation, and the two functions can be performed substantially independently by applying forward and reverse current to the electromagnetic plunger. Since it is configured so that the trigger operation and the operation holding by the suction force are reliably performed, the structure is simplified without the need of a stopper to prevent unnecessary trigger operation, design restrictions and noise generation etc. Can be solved, the clearance between the magnet of the cam gear and the iron core of the electromagnetic plunger can be easily adjusted, and the assembly workability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of an essential part of an operation switching mechanism according to the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. FIG. 4 is a perspective view of an example, and FIG. 4 is a perspective view of a transport of a tape recorder to which an operation switching mechanism is applied.
The figure is a plan view of a conventional operation switching mechanism. In the figure, (21) is a cam gear, (22) is a cam portion, (23) is a toothless portion, (25) is a magnet, (26) is a driving force transmission gear,
(30) is an electromagnetic plunger, (31) is a fixed iron core, (32) is a stable iron core, (32b ₁ ) is a tip, (35) is a movable iron core, (36)
Is a switching lever.

Claims (1)

[Claims] 1. A cam gear having a cam portion having a toothless portion, a magnet having at least two poles magnetized integrally with the cam gear, and an iron core facing one pole of the magnet. And a drive gear that is rotated at a position facing the toothless portion of the cam gear, and a switching lever that is engaged with the cam portion of the cam gear. Sometimes the cam gear is rotated by the repulsive force of the iron core with respect to the magnet and is rotationally driven by meshing with the drive gear, and the switching lever that engages with the cam portion is biased to operate the controlled member. When the electromagnetic plunger is reversely energized, the cam gear is stopped and held by the attraction force to the magnet so that the movable iron core of the electromagnetic plunger is attracted. Action switching mechanism in the recorder.