JPH079227Y2 - Torque measuring cassette - Google Patents

Description

The present invention relates to a torque measuring cassette, and more particularly to a torque measuring cassette suitable for use as a cassette type torque meter or a tape pulling force measuring meter.

[Outline of device]

The reel in the cassette casing is composed of an inner ring and an outer ring, and a spiral spring is arranged between them so that the spring elastically deforms according to the torque so that the outer ring rotates relative to the inner ring. In the torque measurement cassette, the radial dimension of at least one of the electrode plates provided on the inner ring and the outer ring is changed according to the rotational position, and rotational displacement or tape due to tape pulling force is applied. The torque can be accurately measured by increasing the rate of change of the capacity with respect to the rotational displacement between the inner ring and the outer ring due to the winding force of.

[Conventional technology]

Conventionally, a torque measuring cassette has been used to measure the pulling force of a tape recorder or VTR capstan pulling the tape and the reel winding torque. In such a cassette, the reel in the casing is composed of an inner ring and an outer ring, and a spiral spring is arranged between them.
The spring is elastically deformed according to the applied torque, and the outer ring is rotationally displaced relative to the inner ring. In such a cassette, the torque can be known by measuring the relative rotation angle between the inner ring and the outer ring.

[Problems to be solved by the invention]

Therefore, if the inner ring and the outer ring are provided with respective pole plates and the capacitors are configured so that these pole plates can face each other, the capacitance changes according to the relative rotation angle between the inner ring and the outer ring. Therefore, it becomes possible to measure the torque depending on the capacity. However, in the conventional measuring device of this type, since the radial dimension of the electrode plate that constitutes the capacitor is constant regardless of the rotational position, the rate of change of the capacitance with respect to the relative rotational angle is small. The characteristics are shown by the dotted line in the figure. Therefore, according to such a torque measuring cassette, there are drawbacks that it is easily affected by external factors, errors occur, and it is difficult to read.

The present invention has been made in view of such problems, and increases the amount of change in capacitance with respect to the relative rotation angle between the inner ring and the outer ring, thereby making it less susceptible to external factors. It is an object of the present invention to provide a torque measurement cassette that is less likely to cause an error and is easy to read.

[Means for solving problems]

According to the present invention, a reel arranged in a cassette casing is composed of an inner ring and an outer ring, and polar plates are attached to the inner ring and the outer ring so as to be able to face each other. In the cassette, in which the capacity between the pair of polar plates is changed when the elastic means elastically deforms in response to torque and the outer ring relatively rotates with respect to the inner ring by interposing means, The radial dimension of at least one of the polar plates is changed according to the rotational position.

[Action]

Therefore, according to the present invention, when the outer ring rotates relative to the inner ring during the torque measurement, the overlapping angle of the pair of electrode plates changes and the width of the electrode plate at the overlapping portion is changed at the same time. Therefore, the change amount of the capacitance with respect to the relative rotation angle increases.

〔Example〕

FIG. 3 shows a torque measuring cassette according to an embodiment of the present invention. The cassette has a cassette casing 10 having the same shape as a conventional audio cassette. The reel 11 and the take-up reel 12 are stored side by side. These reels
Both 11 and 12 have the same structure and are composed of an inner ring 13 and an outer ring 14 as shown in FIGS. A ball bearing 15 is arranged between the inner ring 13 and the outer ring 14 so that they can rotate relative to each other. A spiral spring 16 is arranged between the inner ring 13 and the outer ring 14, and is housed in a recess 17 (see FIG. 5) formed in the lower surface of the outer ring 14. The inner peripheral end of the spiral spring 16 is locked to the inner ring 13, and the outer peripheral end is locked to the outer ring 14.

A pole plate 20 which also serves as a scale plate is provided on the upper surface of the inner ring 13. The electrode plate 20 has a large radius and extends to the outer peripheral side in the radial direction to a position substantially the same as the outer peripheral surface of the outer ring 14. On the other hand, a pole plate 22 is provided on the step portion 21 on the upper surface of the outer ring 14. As shown in FIGS. 1 and 2, the polar plate 22 has a radial dimension that changes in accordance with the rotation angle. The electrode plate 20 is connected to the slip ring 23, and the brush 24 is arranged in the casing 10 so as to be in sliding contact with the slip ring 23. Also the outer ring 14
The side electrode plate 22 is connected to the slip ring 25,
A brush 26 is arranged in the casing 10 so as to be in sliding contact with the slip ring 25, as shown in FIG. The brushes 24 and 26 are connected to the corresponding capacitance meter 28 via the connector 27 as shown in FIG.

When performing dynamic torque measurement using such a torque measuring cassette, the cassette 12 is mounted on the cassette tape recorder shown in FIG. 3, and the reel 12 on the winding side is driven by the reel shaft. The outer rings 14 of the two reels 11 and 12 are connected to a magnetic tape 32 via a leader tape 31. The magnetic tape 32 is guided in the casing 10 via the guide pins 33 and the guide rollers 34 as shown in FIG. Therefore, when the magnetic tape 32 is run in this manner, the torque applied to the reels 11 and 12 via the magnetic tape 32 or the leader tape 31, respectively, causes the capacity between the pole plates 20 and 22 of these reels 11 and 12 to increase. Will be detected as. That is, in this case, the backup torque is measured by the supply-side reel 11, and the winding torque of the reel shaft is measured by the winding reel 12.

When torque is applied to the outer ring 14 through the magnetic tape 32 or the leader tape 31, the spiral spring 16 interposed between the inner ring 13 and the outer ring 14 elastically deforms in response to the torque, whereby the inner ring 13 is deformed. Therefore, the outer ring 14 rotates relatively. Then, the pair of electrode plates 20 shown in FIG.
The positions of 22 are displaced from each other, which changes the capacitance of the capacitor formed by the two electrode plates 20 and 22.
This change in capacitance has the characteristic shown by the solid line in FIG. 7, and such a change in capacitance is measured by a capacitance meter.
It becomes possible to know the torque by reading through 28.

Moreover, in the cassette according to the present embodiment, as is apparent from FIGS. 1 and 2, when the radial dimension of one of the polar plates 22 is W 0, the torque is W ₁ to some extent. It will change to W ₂ when added, and the outer ring
The radial dimension of the pole plate 22 on the outer ring 14 side is changed at the edge position of the pole plate 20 on the inner ring 13 side in accordance with the relative rotation of 14, thereby increasing the change in the capacity with respect to the torque. There is. Therefore, according to such a measurement, it becomes difficult to be influenced by an external factor, an error is reduced, and it is easy to read.

[Application example]

The present invention has been described above with reference to the illustrated embodiment, but the present invention is not limited to the above embodiment, and various modifications can be made based on the technical idea of the present invention. For example, the above embodiment relates to a torque measuring cassette for a tape recorder, but the present invention can also be applied to a torque measuring cassette for a VTR. Further, although the cassette of the above embodiment is used for measuring the dynamic characteristic, the present invention can be applied to the cassette for measuring the static characteristic. In a cassette for static measurement, the inner ring may be fixed to the casing side, which eliminates the need for the slip ring and brush on the inner ring side.

[Effect of device]

As described above, according to the present invention, the radial dimension of at least one of the two electrode plates constituting the capacitor is changed according to the rotational position. The facing area of the electrode plate is gradually changed so that the change can be read accurately as a change in capacitance. Therefore, it is possible to change the capacitance so that the accuracy error of the structural component can be ignored, and it is possible to provide the torque measurement cassette capable of performing accurate measurement.

[Brief description of drawings]

FIG. 1 is a plan view showing a capacitor of a torque measuring cassette according to an embodiment of the present invention, FIG. 2 is a plan view of a capacitor during torque measurement, and FIG. 3 is a general structure of the torque measuring cassette. A plan view, FIG. 4 is an exploded perspective view of the reel,
FIG. 5 is a front view in which a part of the tape cassette is cut away, and FIG.
FIG. 7 is a cross-sectional view of an essential part showing the structure of the brush portion, and FIG. 7 is a graph showing the relationship between torque and capacitance of the capacitor. The names of the main parts in the drawings are as follows. 10 …… Cassette casing 11 …… Supply reel 12 …… Winding reel 13 …… Inner ring 14 …… Outer ring 15 …… Ball bearing 16 …… Spiral spring 20 …… Pole plate (scale plate) 22 …… Pole plate 31… … Leader tape 32 …… Magnetic tape

Front page continuation (72) Inventor Nobuhiko Watanabe 1-30-9 Ogikubo, Suginami-ku, Tokyo Inside Watanabe Equipment Co., Ltd. (56) Reference JP-A-1-196760 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A reel arranged in a cassette casing is composed of an inner ring and an outer ring, and polar plates are attached to the inner ring and the outer ring so as to be able to face each other, and further, between the inner ring and the outer ring. A cassette in which elastic means is interposed so that the capacity between the pair of polar plates changes when the elastic means elastically deforms in response to torque and the outer ring relatively rotates with respect to the inner ring, A torque measuring cassette, wherein the radial dimension of at least one of the electrode plates is changed according to the rotational position.