JPS6039815Y2 - rotation detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotation detector that can be attached to a tape recorder or the like to send out a tape running signal.

This type of rotation detector has a pulley that is driven to rotate as the tape runs, and a disk-shaped magnet that is magnetized with alternating N and S poles on its circumferential surface and can be rotated integrally with the pulley. On the other hand, a magnetic sensing element such as a Hall IC is arranged on the frame so as to be close to the circumference of the magnet, and a pulse signal is generated from the magnetic sensing element by the rotation of the magnet, and this signal is The configuration is such that the running state (rotation state) of the tape can be detected.

In this case, this rotation detector is often integrated into a tape counter or the like so that it operates together with the tape counter's integrated display of the amount of tape travel.

By the way, a conventional rotation detector has a structure in which the above-mentioned magnet is directly attached to a pulley, and a magnetic sensing element is positioned with respect to this magnet and attached to a frame.

Therefore, if the specifications of the tape recorder to which this rotation detector is attached require various pulley mounting positions, the position of the magnet integrated with the pulley will be changed in accordance with the change in the pulley mounting position, and Accordingly, the mounting position of the magnetically sensitive element must also be changed.

In other words, in order to accurately send out pulses as the tape runs, not only the alignment between the magnetic sensing element and the circumferential surface of the magnet, but also the setting of the interval requires a certain degree of precision. It is necessary to change the tracking position of the sensing element.

Therefore, in the configuration in which the pulley and magnet are integrally attached as described above, it is necessary to provide a degree of freedom in the mounting structure of the magnetically sensitive element so that it can respond to changes in the position of the pulley, or in other words, changes in the position of the magnet. Therefore, the structure becomes complicated, and the mounting position of the element must be adjusted for each specification, making the assembly work troublesome.

In addition, in the past, if the mounting structure of the magnetically sensitive element had a degree of freedom, it was easy to cause misalignment even when the magnetically sensitive element was installed. etc., resulting in a complicated structure and complicated assembly work.

Furthermore, magnetic sensing elements are usually attached to a printed circuit board and then attached to a frame, but it is troublesome to attach them to the printed circuit board with high precision, and even if they can be attached, it is difficult to attach the printed circuit board itself to the frame. If the positional accuracy is low, the mounting accuracy of the element will be low as a result, and there is also the problem that it is difficult to perform good rotation detection.

The present invention was developed in view of the above points, and is structured so that a magnet is attached to the rotating shaft with reference to the end face of the bearing tube of the frame, and a pulley is attached to the other end of the rotating shaft. In addition, the frame is provided with a support part capable of fitting and supporting a magnetically sensitive element structure having a magnetically sensitive element disposed opposite to a part of the circumference of the magnet, and a positioning part for the magnetically sensitive element with respect to the magnet. Regardless of the change in the mounting position of the magnet, it is no longer necessary to change the mounting position of the magnet and the magnetically sensitive element provided opposite thereto, and on the other hand, the work of mounting the magnetically sensitive element is facilitated, which simplifies the structure and facilitates assembly. It is an object of the present invention to provide a rotation detector that can facilitate work and improve the precision of the mounting position of elements.

Hereinafter, the present invention will be explained based on the illustrated embodiments.

Fig. 1 is a partially exploded perspective view of the rotation detector of the present invention, and Fig. 2 is a cutaway front view showing its assembled state.
is a plate-shaped bracket as a frame that has a pair of mounting holes 1a, 1a and is fixed to a device such as a tape recorder with bolts (not shown) or the like.

A bearing sleeve 2 is integrally formed approximately at the center of the bracket 1 and has an appropriate length to protrude vertically, and can rotatably support a rotating shaft 3 inserted through the bracket 1 in the vertical direction.

Further, on one side of the bracket 1, there is integrally formed a support part 4 consisting of a central piece 5 which stands opposed to each other at a small interval, and a pair of side pieces 6, 6, which will be described later. The printed circuit board 7 of the magnetically sensitive element structure can be supported upright.

Furthermore, a holder 9 serving as a positioning portion for the magnetically sensitive element 8 is integrally formed between the side pieces 6, 6.

A plastic magnet 10 is press-fitted into the upper end side (one end side) of the rotating shaft 3 in the figure, and its shaft position is determined by slidingly contacting one end surface 2a of the bearing sleeve 2.

This plastic magnet 10 is made of a plastic material mixed with magnetic powder, and has a substantially disc-shaped circumferential surface with N
The poles and S poles are alternately and continuously magnetized, and the bottom surface of the central recess 10a provided on the lower surface is brought into contact with one end surface of the bearing sleeve 2.

On the other hand, a collar 11 is loosely inserted into the lower end (other end) of the rotating shaft 3 in line with the other end surface 2b of the bearing tube 2, and a pulley 12 is press-fitted so as to sandwich the collar 11.

Therefore, by selecting an arbitrary length for the interposed collar 11 of the pulley 12, the axial position (under-neck dimension l) of the pulley 12 relative to the bracket 1 can be changed as appropriate.

It goes without saying that a rubber belt (not shown) or the like is wound around the pulley 12 and is driven to rotate as the tape runs.

Incidentally, a known indicator disc 13 may be attached to one end of the rotating shaft 3 as shown in the figure.

As shown in detail in FIG. 3, the support portion 4 has side pieces 6,
6 has circular protrusions 6at6a integrally formed on the surfaces of both side pieces facing the center piece 5, and each protrusion 6a, 6a has a positioning hole 7a bored on both sides of the printed circuit board 7.
, 7a.

This printed circuit board 7 has a magnetically sensitive element 8 such as a Hall IC attached to its surface to constitute a magnetically sensitive element structure.
And with this element attached, the imaginary line and the second
As shown in the figure, it is inserted between the center piece 5 and both side pieces 6, 6, and is supported by them.

Further, the holder 9 is formed in a U-shape facing the road, and the magnetically sensitive element 8 can be held between both sleeve pieces 9a, 9a.

As shown in FIG. 2, the upper surface of the lower piece 9b of the holder 9 consists of a tapered surface 9c facing the central piece 5 and a flat surface 9d continuous thereto, and has a tapered portion 8a on the upper edge of the tip. The tapered surface 9c is formed on this tapered portion 8a of the element 8.
can be touched.

The three lead wires 8b of the magnetically sensitive element 8 are connected to the terminal circuit section 7b of the printed circuit board 7 by soldering or the like, and the element itself is not fixed to the printed circuit board.

Therefore, according to the above configuration, when the pulley 12 is rotated, the rotating shaft 3, the magnet 10, and the indicator disc 13 are also rotated, and the indicator disc 1
3 indicates the tape running state, and the magnet 10 cooperates with the magnetically sensitive element 8 to send out a pulse signal.

On the other hand, if the pulley position is required to be changed due to a change in specifications, the pulley 12 and collar 11 should be moved to the rotating shaft.
The pulley 12 is then removed and replaced with a collar having a suitable shaft length, and the pulley 12 is again press-fitted onto the rotating shaft 3 while sandwiching this collar.

As a result, the underneck dimension 1 of the pulley 12 relative to the bracket 1 can be easily changed, and despite this change, the axial position of the magnet 10 remains fixed due to the one end surface 2a of the bearing sleeve 2. Magnetic sensing element 8
There is no need to change the mounting position of the.

In addition, when supporting the magnetically sensitive element structure, that is, the printed circuit board 7 on the bracket 1, the printed circuit board 7 is inserted between the center piece 5 and both side pieces 6, 6, and both sides of the printed circuit board 7 are slightly curved outward. Then, the protrusions 6a, 6 of the side pieces 6, 6 will fit into the positioning holes 7a, 7a of the printed circuit board 7.
A inserts and positions the printed circuit board 7, and at the same time supports the printed circuit board and prevents it from falling off.

For this reason, together with the above-mentioned effect of not changing the mounting position of the magnetically sensitive element, the central piece 5 is formed simultaneously with the integral molding of the bracket 1.
The magnetically sensitive element can be suitably supported simply by forming the two side pieces 6, 6, and the supporting work can be performed extremely easily.

Further, at this time, the magnetically sensitive element 8, which can be moved to some extent with respect to the printed circuit board 7, is fitted into the holder 9 while supporting the printed circuit board.

Positioning in the left and right direction is performed by both sleeve pieces 9a, 9a, and the upper surface of the lower piece 9b, especially the tapered surface 9C.
is pressed against the printed circuit board surface by the wedge action of
d, the distal end surface of the element comes into contact with the flat surface, and positioning in the vertical direction is performed.

Therefore, there is no need to perform highly accurate positioning when attaching the element to the printed circuit board 7, and the element can be positioned with high precision simply by attaching the printed circuit board to the support portion 4.

In addition, if it is possible to maintain high precision in the mounting position of the element on the printed circuit board, the positioning section can have an elastic piece 14 structure as shown in FIG. By pressing the center piece 7 to the center piece 5, it is possible to prevent the positional shift caused by the bending of the printed circuit board.

Here, the rotation detector of the present invention can be integrated into a tape counter as shown in FIG. 5, instead of being constructed independently as in the previous example.

That is, a bearing cylinder 22 is formed in a part of a counter frame 21 that supports a plurality of number wheels 20 in parallel, and a rotating shaft 23 is formed with a bearing cylinder 22.
A supporting portion 24 consisting of a center piece 25 and both side pieces 26 and a positioning portion 27 are integrally formed in the vicinity thereof.

A magnet 28 and a worm gear 29 are attached to the upper part of the rotating shaft 23, and a pulley 31 is attached to the lower part via a collar 30.

The worm gear 29 is a drive gear 32 connected to the number wheel 20.
Needless to say, the number wheel 20 is rotated by meshing with the number wheel 20.

Further, the support portion 24 supports a magnetically sensitive element structure 33.

34 is a zero return lever. Therefore, in this tape counter, by appropriately changing the collar 30, the under-neck dimension of the pulley 31 relative to the counter frame 21 can be changed, while the support structure of the magnetically sensitive element structure is simplified and the installation work is facilitated. It is possible to improve the ability to follow changes in specifications.

Furthermore, even if the magnetically sensitive element is temporarily fixed to the printed circuit board, the element 33 can be fixed to the positioning section 24 simply by supporting the printed circuit board on the support section 24, and the mounting of the element is extremely easy. Become something.

In the above embodiment, when a conventional magnet is used as the magnet 10, instead of being press-fitted onto the rotating shaft 3, it can be integrally attached to the shaft using an auxiliary fixture.

In addition, the magnetic sensing element 8 and the support portion 4 of the printed circuit board 7
The structure of can be modified as appropriate.

As described above, according to the rotation detector of the present invention, a collar is interposed between the bearing cylinder of the frame and the pulley, and the position of the pulley can be changed by selecting this collar with an arbitrary shaft length. In addition, since the support part of the magnetically sensitive element structure and the positioning part of the element are provided in the frame, there is no need to change the position of the magnet regardless of the change in the position of the pulley. In addition, it is possible to simplify the assembling work by eliminating the need for supporting work and adjustment of the supporting position, etc., and to ensure extremely high support accuracy for the magnetically sensitive element. It has the effect of being able to do it.

[Brief explanation of drawings]

Fig. 1 is a partially exploded perspective view of the rotation detector of the present invention, Fig. 2 is a cutaway front view thereof, Fig. 3 is a detailed view of the support part, and Fig. 4 is a sectional view of the main part showing a modification of the positioning part. , FIG. 5 is a partially exploded perspective view of an applied example. 1...Bracket (frame), 2...
・Bearing tube, 3...Rotating shaft, 4...Support part, 5...Central piece, 6...Both sides pieces, 7
...Printed circuit board, 8...Magnetic sensing element, 9...Holder, 10...Magnet, 11...Color, 12... ...Pulley, 14...Elastic piece, 20...Number ring,
22... Bearing tube, 23... Rotating shaft, 2
4...Support part, 28...Magnet,
30...Color 31...Pulley.

Claims (1)

[Scope of utility model registration request] A rotating shaft is inserted into a bearing tube formed in a part of the frame, and a magnet is attached to one end of the rotating shaft with reference to the end surface of the bearing tube, while a pulley is attached to the other end of the rotating shaft. , and the frame is provided with a support part for a magnetically sensitive element structure having a magnetically sensitive element arranged to face a part of the circumference of the magnet, and a positioning part for the magnetically sensitive element with respect to the magnet. Rotation detector.