JP2515015Y2 - Reel stand device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reel base device of a tape recorder, and more particularly to a reel base device having a braking mechanism that applies back tension to a tape to be pulled out.

2. Description of the Related Art The applicant of the present invention has previously proposed a reel mount device having a braking mechanism that utilizes hysteresis loss in Japanese Utility Model Laid-Open No. 59-161530, entitled "Reel mount device".

The braking mechanism has a structure including a magnet structure and a hysteresis ring that rotates around the magnet structure. The hysteresis ring is provided on the reel stand body.

FIG. 9 shows the hysteresis ring 1 taken out. This hysteresis ring 1 is formed by rolling a hysteresis strip 2 shown in FIG. 10 and abutting the ends 3 and 4 on both sides thereof to form a ring.

The ends 3 and 4 of the hysteresis strip 2 are diagonal cuts 5 and 6. The hysteresis ring 1 is formed by abutting diagonal cut portions 5 and 6.

Problems to be Solved by the Invention The slanted cut portions 3 and 4 that are abutted with each other do not have a function of restraining the end portions 3 and 4 of the hysteresis strip 2 so as not to shift in the direction of the axis l of the ring. Therefore, when the hysteresis ring 1 is assembled, the ends 3 and 4 thereof are displaced in the direction of the axis l as shown in FIG. 9, and a gap 7 is likely to be formed between the ends 3 and 4. there were.

When the gap 7 is generated, the braking torque fluctuates, which causes the back tension of the tape to fluctuate, which deteriorates the running characteristics (ower / flutter) of the tape, and eventually deteriorates the characteristics of the tape recorder. .

An object of the present invention is to provide a reel stand device which solves the above problems.

Means for Solving the Problems According to the present invention, a hysteresis ring, which is a ring-shaped hysteresis strip, is provided on the inner peripheral surface of the cylindrical portion of the reel stand body, and a cylindrical shape in which different magnetic poles are arranged alternately in the circumferential direction. Of the magnet structure is fixedly disposed inside the hysteresis ring so as to be spaced apart and opposed to the hysteresis ring, and the magnet structure and the rotating hysteresis ring cooperate to apply a braking force to the rotation of the reel stand body. In the reel base device for applying, the hysteresis strip has one end in the longitudinal direction, the protrusion, and the first ends located on both sides of the protrusion,
A second end, a second end having a recess having a shape corresponding to the protrusion, and a third end corresponding to the first end and the second end, and a fourth end. The first end and the third end of the hysteresis strip are abutted against each other, and the second end and the fourth end are joined to each other. A first abutting portion that is abutted and formed by fitting the protrusion and the recess of the hysteresis strip, and abuts the first end and the third end, and A structure having a second butting portion formed by butting a second end and the fourth end, and having an abutting portion in which an edge of the projecting portion and an edge of the recessed portion are in contact with each other. In addition, when viewed from the peripheral surface side of the reel stand device, the contact portion,
The direction of a line that is inclined with respect to the edge of the magnetic pole piece extending in the direction of the axis of the magnet structure and that connects the first butting portion and the second butting portion is The structure is inclined with respect to the edge.

Action The configuration in which the protrusion and the recess are fitted together acts to restrain the ends of the hysteresis strip from shifting in opposite directions in the axial direction of the hysteresis ring.

The configuration in which the contact portion is inclined with respect to the edge of the magnetic pole piece when viewed from the peripheral surface side of the reel stand device acts so that the contact portion does not cross the line of the magnetic pole piece at the same time.

The configuration in which the direction of the line connecting the first butting portion and the second butting portion as viewed from the peripheral surface side of the reel stand device is inclined with respect to the edge of the pole piece is such that the first and second butting portions are It acts so as not to cross the edges of the pole pieces at the same time.

Embodiment FIG. 2 shows a supply reel base 10 which is an embodiment of the reel base device of the present invention. 1 shows the hysteresis ring 11 in FIG. 2, and FIG. 3 shows the magnet structure 12 in FIG. 2 in a disassembled state.

As shown in FIG. 2, the supply reel base 10 is a reel base body.
It is composed of 13 and a magnet structure 12. The reel stand body 13 is rotatably supported by a reel shaft 40 that is erected on the chassis 14. The magnet structure 12 is fixed to the reel shaft 40.

A hysteresis ring 11, which is an essential part of the present invention, is fitted to the inner peripheral surface of the lower cylindrical portion 13a of the reel stand body 13.

The hysteresis ring 11 is formed by rolling the hysteresis strip 15 shown in FIG. 4 and abutting the ends 16 and 17 into a ring shape. The hysteresis strip 15 is made of an iron / manganese-based semi-hard magnetic material.

One end 16 of the hysteresis strip 15 is a triangular protrusion 18, and the other end 17 is a triangular recess 19 corresponding to the protrusion 18.

The one end 16 is provided on both sides of the protrusion 18 with the first
Further has an end 100 and a second end 101. The other end
117, the third end 200 and the fourth end at positions on both sides of the recessed portion 19.
And 201.

As shown in FIGS. 1 and 5, the hysteresis ring 11 has a first end 100 and a third end 200 butted together, and a second end 101 and a fourth end 201 butted together. Moreover, the protrusion 18 and the recess 19 are formed by fitting. First end 10
The 0 and the third end 200 are butted to form the first butted portion 25. The second end 101 and the fourth end 201 are butted to each other to form the second butted portion 26. The protruding portion 18 and the concave portion 19 that are fitted to each other are restrained from each other,
Hysteresis ring 11 with ends 16 and 17 indicated by arrows Z ₁ and Z ₂
The displacement of the (magnet structure 12) in the direction of the axis l is limited. As a result, there is no gap between the abutted ends 16 and 17. It should be noted that although a gap is shown in FIG. 1, this is for convenience of illustration, and in reality, as shown in FIG. There is no.

As shown in an exploded view in FIG. 3, the magnet structure 12 includes a coil 21 wound around a central electromagnetic soft iron 20 fixed to a reel shaft 40, and a coil 21 sandwiched from above and below. It consists of fixed electrode plates 22 and 23, and is a substantially flat cylindrical body. The pole plates 22 and 23 have four trapezoidal tooth portions (pole pieces) 22a to 22d and 23a to 23d, respectively, and the tooth portions 22a to 22d and 23a to 23d.
The coils d are assembled in a positional relationship in which they are alternately arranged along the peripheral surface of the coil 21 at equal angular intervals. A direct current is supplied to the coil 21, the tooth portions 22a to 22d are magnetized to the N pole, the tooth portions 23a to 23d are magnetized to the S pole, and the N pole and the S pole are arranged on the peripheral surface of the magnet structure 12. The poles are alternating.

The reel stand body 13 and the magnet structure 12 are combined in a state where the magnet structure 12 is fitted in the cylindrical portion 13a of the reel stand body 13, and the magnetic pole surface of the magnet structure 12 is the hysteresis ring 11. It faces the inner surface.

The reel stand main body 13 rotates at a speed according to the tape withdrawn from the reel placed on the reel stand main body 13. By rotating the hysteresis ring 11 so as to face the magnetic poles, an alternating magnetic field is applied to the hysteresis ring 11 to cause a hysteresis loss, which gives a braking force to the rotation of the hysteresis ring 11 (reel stand main body 13). To do. Therefore, the reel stand body 13 rotates against the braking force applied by the non-contact braking mechanism, and the tape pulled out from the supply reel stand 10 is given a back tension corresponding to the braking force.

Here, the hysteresis ring 11 has no gap at its abutting portion, and the braking force is constant without change. By this, the back tension of the tape is evenly applied,
The tape running characteristics are excellent.

It should be noted that if the hysteresis strip 15 has a pointed portion, it is not preferable in terms of strength in terms of manufacturing and handling and is easily injured during handling.Therefore, the protruding portion 18 has a shape in which a triangular vertex is cut off, and the tip is It is reinforced. The tips of the triangular arms 24a and 24b on both sides of the recess 19 are also cut off and reinforced.

In addition, as shown in FIG. 4 and FIG.
The contact portion 27 where 18a and the edge 19a of the recessed portion 19 contact each other is a tooth portion (magnetic pole piece) 22a-2 when viewed from the peripheral surface side of the reel stand device 10.
It is inclined with respect to the edges 28 and 29 of 2d and 23a to 23d. Therefore, the contact portion 27 does not cross the edges 28 of the tooth portions (magnetic pole pieces) 22a to 22d at the same time, and does not cross the edge 29 of the tooth portions (magnetic pole pieces) 23a to 23d at the same time. With this configuration, the control torque is further constant.

Further, as shown in FIG. 5, the first and second butting portions 25, 26 of the hysteresis ring 11 are aligned in the reel axial direction. Therefore, the tooth portions (magnetic pole pieces) 22a to 22d and 23a to 23d are both trapezoidal so that the edges 28 and 29 of the tooth portions (magnetic pole pieces) do not cross the first and second butting portions 25 and 26 at the same time. I am doing it. With this configuration, the braking torque becomes more constant.

FIG. 6 shows a modification of the hysteresis ring 11.
The hysteresis ring 30 is formed by rolling the hysteresis strip 31 shown in FIG.

The hysteresis strip 31 has an asymmetric triangular protrusion 33 at one end 32 and a recess 35 corresponding to the protrusion 33 at the other end 34. The projecting portion 33 and the recessed portion 35 are fitted to each other as shown in FIGS. 6 and 8, and the displacements of the end portions 32 and 34 in the directions opposite to each other in the directions of arrows Z ₁ and Z ₂ are restricted. There is no gap between the ends 32 and 34. In FIG. 6, a gap is shown, but this is for convenience of illustration, and in reality,
As shown in FIG. 8, the ends 32 and 34 are in close contact with each other, and there is no gap therebetween.

Even when this hysteresis ring 30 is applied, the same effect as above can be obtained.

The butting portions 36 and 37 of the hysteresis ring 30 are circumferentially offset from each other. Therefore, even if the tooth portions 39, 40 forming the magnetic poles of the magnet structure 38 are rectangular in shape, the edges of the magnetic poles do not cross the abutting portions 36, 37 at the same time.

Effect of the Invention As described above, according to the reel base device of the present invention, the protrusions and the recesses are fitted to each other, so that the ends of the hysteresis strips are opposite to each other in the axial direction of the hysteresis ring. Therefore, the hysteresis ring can be formed without a gap between the ends of the hysteresis strip, and the absence of the gap can provide a constant braking force.

Further, as viewed from the peripheral surface side of the reel stand device, the contact portion between the protruding portion and the recess portion is inclined with respect to the edge of the magnetic pole piece, and
Since the direction of the line connecting the abutting portion and the second abutting portion is inclined with respect to the edge of the magnetic pole piece, the abutting portion is prevented from crossing the edge of the magnetic pole piece at the same time, and a plurality of abutting portions are provided. May not cross the edges of the pole pieces at the same time, and the presence of abutting and abutting parts may have minimal effect on the variation of the braking force, which further reduces the variation. You can get no braking force.

Therefore, it has a feature that the tape running characteristics (wow and flutter) of the tape recorder can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a hysteresis ring which constitutes a main part of the reel stand apparatus of the present invention, FIG. 2 is a sectional view of an embodiment of the reel stand apparatus of the present invention, and FIG. 3 is a magnet in FIG. FIG. 4 is an exploded perspective view of the structure, FIG. 4 is a plan view of the hysteresis strips that form the hysteresis ring of FIG. 1, and FIG. 5 is the end of the hysteresis strip of the hysteresis ring of FIG. 6 is a perspective view showing a modified example of the hysteresis ring, FIG. 7 is a plan view of a hysteresis strip constituting the hysteresis ring of FIG. 6, and FIG. FIG. 10 is a view showing a portion of the hysteresis ring of FIG. 6 where the ends of the hysteresis strips are butted in correspondence with each other, and FIG. 9 is a perspective view of the hysteresis ring of the conventional reel stand device, FIG. Is It is a plan view of a hysteresis strip constituting the hysteresis ring of Figure 9. 10 …… Supply rule stand, 11,30 …… Hysteresis ring, 1
2,38 ...... Magnetic structure, 13 ...... Reel stand main body, 13a ...... Cylindrical part, 14 ...... Cashier, 15,31 ...... Hysteresis strip, 16,17,32,34 ...... End part, 18, 33 …… Projection, 19,35…
… Dent part, 20 …… Electromagnetic soft iron, 21 …… Coil, 22,23 ……
Electrodes, 22a-22d, 23a-23d, 39, 40 ... Tooth (pole piece), 2
4a, 24b …… arm part, 25 …… first butting part, 26 …… second butting part, 36,37 …… butting part, 18a …… edge of projecting part, 19a …… edge of recessed part, 27 …… Abutting part, 28,29…
... Edge of tooth (pole piece), 100 ... first end, 101 ... second
Edge, 200 ... third edge, 201 ... fourth edge.

Claims (1)

(57) [Scope of utility model registration request] 1. A cylindrical magnet structure in which a hysteresis ring having a ring-shaped hysteresis strip is provided on the inner peripheral surface of a cylindrical portion of a reel stand main body, and a cylindrical magnet structure in which magnetic poles which are different in the circumferential direction are alternately arranged. In a reel stand device fixedly arranged inside the ring so as to be spaced apart and opposed to the hysteresis ring, and the braking force is applied to the rotation of the reel stand body in cooperation with the magnet structure and the rotating hysteresis ring, The hysteresis strip has a shape in which one end in the longitudinal direction has a protrusion and a first end and a second end located on both sides of the protrusion, and the other end is A configuration having a recess having a shape corresponding to the protrusion, a third end corresponding to the first end, and a fourth end corresponding to the second end, wherein the hysteresis ring is Hysteresis band The first end and the third end of the piece are butted, the second end and the fourth end of the piece are butted, and the protruding portion and the recessed portion of the hysteresis strip are fitted together. A first butting portion formed by joining the first end and the third end together, and a second butting portion formed by butting the second end and the fourth end together. The contact portion has a butting portion, and the contact portion is in contact with the edge of the protruding portion and the edge of the recess portion, and the contact portion is seen from the peripheral surface side of the reel stand device. Is inclined with respect to the edge of the magnetic pole piece extending in the axial direction of the magnet structure, and the direction of the line connecting the first butting portion and the second butting portion is the magnet. A reel stand device having a structure inclining with respect to one edge.