JPH0528582Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a cassette-type tape tensile force measuring device for measuring the tensile force of a cassette-type tape.

[Conventional technology]

The present invention relates to a tensile force measuring device for a cassette type tape, and in particular, an outer ring is rotatably supported with respect to an inner ring that is locked to a cassette casing, and a spring is interposed between the inner ring and the outer ring. FIG. 6 shows a cassette type tape tensile force measuring device in which the tensile force of the tape whose one end is fixed to the outer ring is measured by the amount of rotation of the outer ring relative to the inner ring due to the deformation of the spring. - What is shown in FIG. 11 has been proposed.

Such a tape tensile force measuring device is used in a recording/reproducing device using a tape-shaped recording medium such as a cassette-type tape recorder or a VTR (video tape recorder). This is used to test whether or not it has a predetermined function. In other words, it is used for checking tape recorder and VTR production lines, or for investigating the cause of failures during service.

First, the outline of the cassette type tape tensile force measuring device will be explained with reference to FIG. 6. This device is equipped with a cassette casing 1 having the same shape as a tape cassette. The casing 1 is composed of a pair of upper and lower halves 2 and 3 made of synthetic resin. The halves 2 and 3 are connected to each other by a predetermined number of screws 4, for example, five screws. Casing 1 composed of these halves 2 and 3
A tape tensile force measuring reel 5 and a dummy reel 6 are housed inside.

As shown in FIG. 2, the tape tensile force measuring reel 5 consists of an inner ring 7 (see FIG. 7A) held on the cassette casing 1 and a ball 9 held in a retainer 8 (see FIG. 7B). ) (Fig. 7C). And inner ring 7 and outer ring 1
A spiral spring 11 is interposed between the inner ring 7 and the outer ring 10, with the inner end and the outer end thereof fixed to the inner ring 7 and the outer ring 10 (FIG. 7D). A scale 12 indicating the tensile force of the tape is engraved on the upper end surface of the outer ring 10. Further, a pointer 13 is fixed to the inner ring 7, and is configured to read the value indicated by the pointer 13 on a scale 12 to obtain a measured value. Furthermore, a reel shaft insertion hole 14 is formed through the inner ring 7 at its center, and a plurality of protrusions 15 for engaging with the reel shaft are protruded from the inner peripheral surface of this insertion hole 14. .

On the other hand, the dummy reel 6 is composed of an inner ring 16 and an outer ring 17, as shown in FIG. A rod spring 18 bent into a substantially square shape is interposed between the two wheels 16 and 17. Both ends of this bar spring 18 are connected to small holes 1 formed in the outer ring 17.
9. Also, a rectangular bar spring 1
The top of the bar spring 18 is received in a groove 20 formed on the inner circumferential surface of the outer ring 17, and the side portion between the tops of the bar spring 18 is received in a groove formed on the outer circumferential surface of the inner ring 16. 21 has been accepted. Thereby, the inner ring 16 is rotatably supported relative to the outer ring 17. A reel shaft insertion hole 22 is also formed in the center of the inner ring 16 of the reel 6, and a plurality of protrusions 23 protrude from the inner peripheral surface of the insertion hole 22 for engaging with the reel shaft. . Further, a magnetic recording tape 24 is fixed at both ends to the outer ring 10 of the tape tensile force measurement reel 5 and the outer ring 17 of a dummy reel, and is wound around these reels 5 and 6 and stored in the cassette casing 1. has been done. The tape 24 is guided by a pair of tape guide pins 25 and a pair of guide rollers 26 to the front wall 27 of the cassette casing 1.
It extends in parallel with the wall portion 27 on the inside. The operation of measuring tape tensile force using the measuring device shown in FIG. 8 will be explained with reference to FIGS. 8 and 9. When this measuring device is attached to, for example, a cassette-type tape recorder, the capstan 30 is inserted into the through holes 28 and 29 (see FIG. 6) formed in the upper and lower halves 2 and 3 of the casing 1. 30 is located inside the tape 24 that is stretched around the inside of the wall portion 27. If you switch the tape recorder to recording mode or playback mode in this state, the pinch roller 3
1 enters into the cassette casing 1 through an opening 32 formed in the front wall 27 of the casing 1, and the tape 24 is pinched by the capstan 30 and the pinch roller 31. Since the capstan 30 is rotating at a constant speed, the tape 24 is thereby subjected to a tensile force.

This tensile force is measured by the tape tensile force measuring reel 5.
A force is applied to the outer ring 10 of the reel 5 to rotate it counterclockwise in FIG. Therefore, the outer ring 10 rotates relative to the inner ring 7 while elastically deforming the spiral fit 11. and the tensile force applied to the tape 24 and the spiral spring 1
The elastic restoring force of outer ring 1 is in a balanced state.
0 stops rotating with respect to the inner ring 7. The tape tensile force is determined from the value on the scale 12 indicated by the pointer 13 at this time.

At this time, since the inner ring 7 of the reel 5 is locked to the casing 1, the supply-side reel shaft 33, which is engaged with the inner ring 7, remains stationary together with the inner ring 7. Further, since the reel shaft 34 on the winding side that is engaged with the inner ring 16 of the reel 5 is rotationally driven, the inner ring 16 rotates together with this reel shaft 34. That is, the inner ring 16
rotates while being supported by a bar spring 18 with respect to the stationary outer ring 17.

Next, regarding the structure of locking the inner ring 7 of the tape tensile force measuring reel 5 to the casing 1, the eighth section
To explain with reference to the figures and FIG. 10, the inner ring 7 is formed with a pair of arcuate long holes 37.
These long holes 37 penetrate the inner ring 7 in the axial direction. On the other hand, halves 2 and 3 of cassette casing 1
A pair of small holes 38 are formed in each of the holes.
A pair of locking pins 39 whose upper and lower ends are supported by these small holes 38 are loosely fitted into the pair of elongated holes 37 . Also, a locking piece 4 is provided at one end of the elongated hole 37.
A coil spring 41 is interposed between the locking piece 40 and the pin 39.
As a result, the inner ring 7 is urged to rotate clockwise in FIG. 8. Note that the elastic restoring force of this spring 41 is much weaker than the elastic restoring force of the spiral spring 11 described above.

Therefore, when no tensile force is applied to the tape 24, the inner ring 7 rotates clockwise due to the elastic restoring force of the coil spring 41, as shown in FIG. 8, and the coil fit 41 contracts. is in a state of
When a tensile force is applied to the tape 24 in this state, the inner ring 7 and the outer ring 10 rotate counterclockwise in FIG. 8 as a unit against the coil spring 41. That is, since the elastic restoring force of the coil spring 41 is smaller than the elastic restoring force of the spiral spring 11,
At this time, the spiral spring 11 is not elastically deformed, and the reel 5 rotates as a unit.

As shown in FIG. 11, the coil spring 41
When the pin 39 is extended and comes into contact with the clockwise end of the elongated hole 37, the inner ring 7 can no longer rotate counterclockwise relative to the casing 1, so the spiral spring 11 becomes elastic. Deformed and outer ring 1
0 will rotate relative to the inner ring 7, and the tensile force applied to the tape 24 will be measured as described above.

In this way, until a tensile force is applied to the tape 24 and the pin 39 comes into contact with the end of the elongated hole 37,
For example, the play that exists in the joint between the spiral spring 11 and the inner ring 7 or the joint between the spiral spring 11 and the outer ring 10 may be caused by the play in the coil spring 4.
1, it will be completely removed by elastic force.

Therefore, the amount of angular displacement that occurs between the inner ring 7 and the outer ring 10 after the pin 39 comes into contact with the end of the elongated hole 37 corresponds completely to the above-mentioned tensile force of the tape 24, so this amount of angular displacement By reading from the scale 12, the above-mentioned tensile force of the tape 24 can be determined with the naked eye.

[Problem that the invention attempts to solve]

However, the conventional cassette case torque meter is a mechanical type, and the hub is divided into two parts, an inner ring and an outer ring.
Since it is divided into two parts, it is easy for errors caused by the measurer to occur. Since the indicator plate on the outer ring 10 also rotates, it is difficult to read with the naked eye when the cassette cassette is placed in a cassette tape recorder, and it is necessary to determine whether the quality is good or bad from this indicator value, which is difficult for production in the flow process. do not have. It could not be used for front loading types such as car stereos. Furthermore, if the device is placed in a constant temperature bath or the like, continuous torque fluctuations cannot be measured over time. Furthermore, since the output was not obtained as an electrical signal, data could not be collected using a computer.

The present invention has been devised to overcome these drawbacks, and an object of the present invention is to provide a cassette-type tape tensile force measuring device that has a simple configuration and can easily measure torque values.

[Means for solving problems]

The present invention is a cassette type tape tensile force measuring device, which includes an inner ring 7a and an outer ring 10a having magnetic patterns 7b and 10b;
It has magnetic detection elements 44 and 45 corresponding to 0a.

[Effect]

The cassette type tape tensile force measuring device of the present invention includes an inner ring 7a and an outer ring 1 having magnetic patterns.
0a, and magnetic detection elements 42 and 45 corresponding to the inner and outer rings 7a and 10a, while fully utilizing the dimensions and shape of the conventional cassette case body and the reliability of the mechanism, it is possible to This made it possible to easily obtain continuous measurements using a constant temperature bath, or to perform large amounts of measurements and torque data processing.

〔Example〕

An embodiment of the cassette type tape tensile force measuring device of the present invention will be described below with reference to FIGS. 1 to 5. In these FIGS. 1 to 5, parts corresponding to those in FIGS. 6 to 11 are given the same reference numerals, and detailed explanation thereof will be omitted.

In Fig. 1, 7b and 10b indicate magnetic sheets, and these magnetic sheets 7b and 10b have their N and S poles magnetized as shown in Fig. 2. As shown in FIG. 3, the difference in the center angles of the N poles of the inner ring 7a and the outer ring 10a is detected by the difference between the magnetic detection elements 44 and 45 provided on the support 42.
Here, the magnetic detection elements 44 and 45 are formed by Hall elements, detect changes in the direction of magnetic flux, and convert them into electrical signals. Further, 43 is a stopper. The output signals of the magnetic detection elements 44 and 45 (FIGS. 4A and 4B) are supplied to waveform shaping circuits 48 and 49 via amplifiers 46 and 47. Further, the output signals of the magnetic detection elements 44 and 45 are passed through amplifiers 46 and 47 to a waveform shaping circuit 48.
The determination circuit 50 determines the difference ΔT=T ₂ −T ₁ between the rising edges of the waveform-shaped pulse signals T ₁ and T ₂ , and displays the torque value, for example, 10 g·cm, based on the determination. 51. The other parts shall be formed in the same manner as a conventional cassette type tape tensile force measuring device.

In this embodiment configured in this manner, the torque detection operation is performed in the same manner as in the conventional case, and during this detection, the mutual deviation between the north poles of the magnetic sheets 7b and 10b is detected, and the electrical signal thereof is supplied to the display device 51. , for example, will be displayed as 10g・cm.

According to this embodiment described above, since the torque value is extracted and displayed as an electrical signal,
Errors caused by the measurer are beginning to disappear. Since it can be taken out as an electrical signal, it can also be used in front-loading types such as car stereos. Furthermore, continuous changes can be measured when placed in a thermostat at 5 to 15 degrees Celsius or 40 to 60 degrees Celsius, and since it is detected as an electrical signal, signal data can be easily compiled. Furthermore, quality can be more easily determined based on the torque value than the indicated value on the display device 51.

Furthermore, by printing scales and pointers on the magnetic sheets 7b and 10b, it is also possible to use the conventional method of visual inspection.

It goes without saying that the present invention is not limited to the above-described embodiments, and that various other configurations may be adopted without departing from the gist of the present invention.

[Effect of idea]

The cassette type tape tensile force measuring device of the present invention has an inner ring and an outer ring having a magnetic pattern, and magnetic detection elements corresponding to the inner and outer rings, and the measured torque value can be extracted using an electric signal. With a simple configuration that takes advantage of the dimensions and shape of a conventional cassette, torque values can be easily measured with the naked eye with little error, and can be used in flow processes, or for continuous torque measurement in front loading type devices such as car stereos or in thermostats. It has the advantage of being able to better measure changes in over time. Furthermore, since the output signal is obtained from an electrical signal, there is an advantage that data can be aggregated using a computer.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the cassette type tape tensile force measuring device of the present invention, Fig. 2 is a line diagram showing an example of the main part of the example in Fig. 1, and Fig. 3 is the system of the example in Fig. 1. 4 and 5 are diagrams for explaining the example shown in FIG. 1, and FIGS. 6 to 11 are diagrams showing examples of a conventional cassette type tape tension measuring device. 7a and 10a are the inner ring and outer ring, 7b and 10
b is a magnetic sheet, and 44 and 45 are magnetic detection elements.

Claims (1)

[Scope of utility model registration request] It has an inner ring body in which a reel shaft insertion hole is formed and an outer ring body rotatably connected to the inner ring body,
A magnetic pattern is provided on each of the inner ring body and the outer ring body, and a magnetic detection device for detecting the magnetic pattern is provided corresponding to the inner ring body and the outer ring body, and a tape pulling force is applied by the output of the magnetic detection device. A cassette-type tape tensile force measuring device characterized in that it measures .