JPS6134590Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a torque meter for measuring the rotational torque of a reel drive shaft in a tape recorder that uses a compact cassette called a Philips type cassette. It relates to something that is intended to be smooth and to minimize measurement errors. Conventionally, to measure the torque of the reel drive shaft, a string attached to a spring scale is hooked to a reel pin, etc., and the tape recorder is placed in a playing state.
It is known to perform a predetermined operation and measure the torque from the spring scale reading (grams) and the reel diameter (cm). However, in such a case, the time and effort required to measure the torque was complicated, and the value was determined by calculation each time, which was inefficient and extremely inconvenient for torque measurement on a mass production line. In contrast, an inner race that fits on the reel drive shaft and has an index scale, and an outer race that is concentrically related to the inner race via a spring and has a scale (torque display) around the periphery are installed inside the housing. With the advent of cassette-type torque meters housed in tape recorders, it has become possible to read torque easily and quickly by simply installing the cassette at a predetermined location on a tape recorder. However, with this configuration, the torque of the reel drive shaft fluctuates over time (occurrence of locking torque), and the position of the pointer relative to the scale fluctuates constantly, making it impossible to read the scale correctly. There were flaws. In addition, a phenomenon appears in which the torque fluctuations occurring in the friction mechanism of the reel drive shaft are amplified, and the apparent torque fluctuations become significantly large, causing the torque meter pointer to fluctuate greatly, making it difficult to read the true value. was difficult. The present invention was devised in view of the drawbacks of the conventional technology, and therefore, the object of the present invention is to provide an inner tape recorder having an index part such as a pointer that is fitted onto the reel drive shaft of a tape recorder and rotates. A stepped regulating portion and a stopper are provided between the race and an outer race having a scale on the flange around which the magnetic tape is wound to regulate the relative rotational position of the inner race and the outer race. It is an object of the present invention to provide an apparatus that prevents the above-mentioned indicator from swinging by interposing high-viscosity silicone oil between the race and the outer race, thereby allowing highly accurate torque measurement. An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a partially cutaway plan view showing an embodiment of the present invention, and FIG. 2 is a sectional view of the same main part, and the application to a cassette tape recorder will be specifically explained. First, cassette half 1 has a shape that is almost the same as a so-called Phillips type, and on the left and right sides of this cassette half 1 there are inner inner cassettes with claw protrusions that engage with the reel drive shaft of a cassette tape recorder. A race 2 and an outer race 3 concentrically related to the outer periphery of the inner race 2 are arranged so as to face a through hole (a reel drive shaft insertion hole) formed in a well-known cassette half 1. And between the inner lace 2 and outer lace 3, there is a second
As shown in the figure, a torque detection spring 4 is tensioned on the lower surface of each of these. Note that 5 is a bearing interposed in annular grooves 6 and 7 on the outer and inner circumferential surfaces of the inner race 2 and outer race 3, respectively. Also,
Reference numeral 8 denotes an index scale engraved on the upper surface of the inner race 2, and is urged to rotate in the same direction by the rotation of the reel drive shaft. On the other hand, a scale plate 9 for displaying the torque value is attached to the circumferential surface of the outer race 3, and a stopper 10 is provided protruding from the inner surface of the scale plate 9 to restrict excessive deflection of the inner race 2. This is arranged in a step-like regulating part 11 cut out in the upper surface of the inner race 2. Note that 12 is a magnetic tape. Further, a bearing 5 interposed in the annular grooves 6 and 7
are held in relation to each other by retainers (not shown) so that they can move smoothly at predetermined intervals. Furthermore, an inner race 2 and an outer race 3 including the annular grooves 6 and 7
A high viscosity silicone oil is interposed between the two. Next, the operation of the device configured as described above will be explained. First, the cassette half 1 forming the main body of the torque meter is inserted into the playing position of the cassette tape recorder, and a play operation is performed. This results in
The reel drive shaft, which is brought into contact with the reel stand drive unit such as a motor through a friction member such as felt, is driven, and therefore the inner race 2
is driven in the direction of solid arrow A. Then, the index scale 8 also moves in the same direction, and the outer race 3, which is connected to the inner race 2 via the spring 4, is also rotated in the same direction. However, due to the bending force of the spring 4, the outer race 3 is not driven directly and follow-up by the inner race 2, but follows the rotation of the inner race 2 with a delay and oscillation. becomes. That is,
Such a torque meter is such that the drive torque of the reel drive shaft can be read out, and the amount of displacement of the outer race 3 relative to the inner race 2 due to the amount of change in the deflection of the spring 4 can be read out using the index scale and the scale on the scale plate 9. Even though the torque was adjusted correctly, it was not possible to measure the correct torque due to the above-mentioned oscillation. And if this agitation is significant,
Even the significance of the existence of such a torque meter was beginning to be lost. The mechanism of occurrence of this oscillation is that torque fluctuations of the friction mechanism between the drive section of the reel stand and the reel stand equipped with the reel drive shaft are superimposed at the time when the oscillation periods of the spring 4 coincide. This is thought to occur because the apparent torque becomes significantly larger. Therefore, in such a case, the fluctuation of the scale plate 9 with respect to the index scale 8 becomes large, making it difficult to read out the true value of torque. Therefore, in the present invention, high viscosity silicone oil is interposed between the inner race 2 and the outer race 3 constituting the torque meter, so that the above-mentioned inertial or synergistic addition of the silicone oil is provided. They succeeded in suppressing the necessary torque fluctuations. The table below shows the torque fluctuation test results for the case where silicone oil is interposed between the inner race 2 and outer race 3 and the case where silicone oil is not interposed as in the conventional case. .

[Table] According to this, the torque fluctuation that occurs in a conventional torque meter is a minimum of 4 g-cm, but a maximum of 22 g-cm.
g-cm, which means that it is either impossible to measure the torque of the reel drive shaft, or even if it is possible, a large error occurs. And the viscosity is 10000
When Stokes (CST) silicone oil is injected between the inner lace 2 and outer lace 3, the minimum amount is 0 g-cm and the maximum is 4 g-cm.
It can be seen that the effect of suppressing the torque fluctuation due to the high viscosity silicone oil is more remarkable than that of conventional products. That is,
When the above-mentioned torque is calculated by converting the tension strength using a tension analyzer, the above-mentioned fluctuation is approximately the value of the error in the tension analyzer reading and the loss torque of the torque meter itself.
You can read values that approximate the true value. On the other hand, in the same table, when silicone oil with a viscosity of 30,000 stokes (cst) is used, the followability of the outer race to the inner race becomes too strong in the above-mentioned Phillips type cassette. , torque measurements begin to become difficult to read. On the other hand, when using silicone oil with a viscosity of 10,000 stokes (cst) or less, on the other hand, with the above-mentioned Phillips type cassette, the above-mentioned followability is as poor as when using normal lubricating oil, and when using a silicone oil with a viscosity of 10,000 stokes (cst) or less, it is extremely poor. Therefore, if only silicone oil of 10,000 stokes (cst) or less is used, the intended purpose cannot be achieved. As described above, the present invention provides an inner race that is rotationally biased by a reel drive shaft, an outer race that is rotatably supported by the inner race via a bearing, and a gap between the inner race and the outer race. and a torque detection spring interposed in the inner race, and the torque is measured from the degree of deviation of the outer race with respect to the inner race. A stopper is provided to be interposed within the step-like regulating section, and the relative rotational position of the inner race and the outer race is regulated by the contact between the stopper and the step-like regulating section, and the relative rotational position of the inner race and the outer race is controlled. By interposing high viscosity silicone oil between them, the followability or braking performance of the outer race with respect to the inner race is made good, and the scale of the torque meter does not fluctuate greatly due to fluctuations in the torque of the reel drive shaft. This prevents the index scale from becoming difficult to read. In particular, in the present invention, the relative rotational position of the inner race and the outer race is regulated by the contact between the step-like regulating part and the stopper, so that the rotation is regulated beyond the elastic limit of the spring for torque detection, and further, the relative rotational position of the inner race and the outer race is Due to the action of the silicone oil interposed between the inner race and the outer race, sudden collision between the stopper and the step-like regulating part can be prevented during relative rotation of the inner race and the outer race, preventing unnecessary damage and maintaining a high-precision state at all times. can be maintained. Therefore, the true value of torque can be read with high precision. In addition, since high viscosity silicone oil is simply injected between the inner race and outer race of the conventional product, this type of torque meter can be offered to the market at low cost without making any complicated changes to the configuration of the conventional product. There are various effects.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially cutaway plan view of a torque meter according to the present invention, and FIG. 2 is a schematic front sectional view of the main parts. 2...Inner lace, 3...Outer lace, 4...Spring, 8...Indicator scale.

Claims (1)

[Scope of utility model registration request] An inner race that is fitted onto a reel drive shaft of a compact cassette tape recorder and rotated; an outer race that is rotatably supported by the inner race via a bearing; and an outer race that is interposed between the inner race and the outer race. and a torque detection spring for measuring the torque of the reel drive shaft from the degree of deviation of the outer race with respect to the inner race. The race is provided with a stopper interposed within the step-like regulating part, and the relative rotational position of the inner race and the outer race is regulated by contact between the stopper and the step-like regulating part, and the inner race and the outer race are A torque meter characterized in that silicone oil having a viscosity of 10,000 to 30,000 Stokes is interposed between the torque meter and the torque meter.