JPH04194437A - Transmitting method by timing belt - Google Patents

Abstract

PURPOSE:To reduce the cost and improve the transmitting accuracy by linking two or more timing belts, having a plurality of natural vibrations, transmitted on timing belt pulleys. CONSTITUTION:For instance, by linking two timing belts 15, 16, having a plurality of vibrations, on timing belt pulleys 14, 7 of an ultrasonic probe, vibratory amplitude of a transmitting system of the pulley and belt can be decreased. As a result, an improper timing belt, having a plurality of vibrations, is changed proper to enable synchronous transmission of substantially improving transmission accuracy, so that swinging of an ultrasonic diagnostic picture can be eliminated. Further by using a timing belt of good product level, higher accuracy of transmission can be further contrived. Rubber and polyurethane are used as a material of the timing belt, and polyester and polyamide fibers are used as a material of a core unit.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a transmission method using a timing belt used in transmission systems in various technical fields where transmission accuracy is required.

Conventional technology Transmission using a timing belt has the same synchronicity as a combination of gears and chenno, which is constant angular velocity motion, but it is lightweight, compact, has low driving noise, does not require lubrication, etc. that cannot be achieved with a combination of gears and chenno. Recently, OA (office automation),
Applications for high-precision transmission systems in home appliances, etc. are expanding.

Conventional timing belts are made of a rubber material and reinforced with a core embedded inside. □In the past, in order to achieve more complete engagement with the timing belt pulley and improve transmission accuracy, the tooth shape of the timing belt (timing bell) was improved by improving mold accuracy or improving molding conditions. Efforts were being made to make it more complete.

Problems to be Solved by the Invention However, even if the accuracy of the tooth profile of the timing belt is improved or the manufacturing process is improved as described above, because the material is polymer (rubber), it is difficult to obtain accuracy above a certain level. Currently, it is impossible to do so, and this results in some degree of variation in quality. In particular, recent office automation equipment, home appliances, and the like have come to require more accurate transmission characteristics, and it has been extremely difficult to manufacture timing belts of constant quality that meet these requirements.

In addition to the above technical fields, for example, timing belts are used in the internal mechanism system of mechanical sector type ultrasound probes, which are the sensor parts of medical ultrasound diagnostic equipment. This disturbance directly affects the "shaking" of ultrasound diagnostic images. Even in the case of mechanical sector type ultrasonic probes, as in the case of the above-mentioned OA1 home appliances, extremely high precision is required for the transmission system, so even if the mechanical system is adjusted, the quality of the timing belt will be low. Since it remained below 40%, improvement of the transmission system was desired.

The present invention solves the problems of the prior art as described above, and improves transmission accuracy even if the timing belt is not of good quality. For example, it is possible to prevent "shaking" in ultrasonic diagnostic images, Therefore, it is an object of the present invention to provide a transmission method using a timing belt that allows the timing belt to be easily manufactured and, as a result, to reduce costs.

Means for Solving the Problems The technical solution of the present invention for achieving the above object is as follows:
Two or more timing belts with multiple vibrations are placed around a timing belt pulley to transmit power.

It is appropriate to use rubber or polyurethane as the material for the timing belt, and it is appropriate to use polyester or polyamide fiber as the material for the core.

Therefore, according to the present invention, even if each of the timing belts is defective, they interfere with each other and suppress abnormal vibrations, bringing the vibrations of the transmission system closer to steady single vibrations and reducing the amplitude. As a result, synchronous transmission with significantly improved transmission accuracy becomes possible. By realizing such synchronous transmission, for example, diagnostic image "shaking" in an ultrasonic diagnostic apparatus can be eliminated.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

1(a) and 1(b) show an example in which the transmission method using a timing belt according to one embodiment of the present invention is applied to an ultrasonic probe, and FIG. 1(a) is a partially broken front view. Figure, Figure 1 (
b) is an enlarged sectional view of the main part.

As shown in FIGS. 1(a) and 1(b), a motor 2 is supported within the rear part of a case 1. As shown in FIGS. A rotor shaft 5 is rotatably supported by a pair of shaft supports 3.4 in the front part of the case 1. A rotor 6 and a timing belt pulley 7 are attached to the rotor shaft 5, and the rotor 6 is equipped with an ultrasonic vibrator 8. An intermediate shaft 11 is rotatably supported on the shaft supports 3 and 9 in a direction orthogonal to the motor shaft 10.
Bevel gears 12 and 13 are fixed to the intermediate shaft 11, and these bevel gears 12 and 13 are meshed with each other. A timing belt pulley 14 is attached to the end of the intermediate shaft 11. Two timing belts 15 and 16 having a plurality of vibrations are endlessly hung between the driving side timing belt pulley 14 and the driven side timing belt pulley 7 on the rotor 6 side.

Then, the drive of the motor 2 rotates the intermediate shaft 11 via the bevel gears 12 and 13, and the rotation of the intermediate shaft 14 rotates the timing belt pulley 14 on the driving side.
Along with this, the timing belt pulley 7 and the rotor 6 on the driven side are connected to each other via the two timing belts 15 and 16.
Rotate and drag the subject.

The timing belts 15 and 16 mentioned above are made of rubber,
Or use polyurethane as the core material,
Polyester or polyamide fibers are used.

In order to quantitatively evaluate timing belt transmission, we prototyped a timing belt transmission characteristic evaluation system as shown in Figure 2. To explain this evaluation system, the second
As shown in the figure, a timing belt 25 is endlessly looped around the timing belt pulleys 23 and 24 on each rotating shaft of a drive-side motor 21 with an encoder and a driven-side motor 22, and the motor 21 is connected to a DC stabilized power source 26. Measure the encoder pulse output during steady rotation, and as shown in Figure 4,
The pulse rise time difference (Δt) between the driving side (Ach) and the driven side (Bch) is measured using a time interval analyzer (H
P5732A) 27, and using the data, the microcomputer 28 can perform frequency analysis.

Data evaluated using this system are shown in Figures 5 and 6. This data corresponds to a good product with no "shake" in the image and a defective product with "shake J" when one timing belt is used to transmit the ultrasonic probe mentioned above.This data is a measurement of Δt at approximately 5.000 points, and while the good timing belt shown in Figure 5 exhibits constant vibration, the defective timing belt shown in No. 6rjfJ exhibits multiple vibrations. The value of Δt (amplitude) was also smaller for the good timing belt.Furthermore, the results of frequency analysis based on this data are shown in Figures 7 and 8 for the good timing belt and the defective timing belt, respectively. 7 and 8, it is clearly seen that a good timing belt has a steady single vibration, and a defective timing belt has a plurality of vibrations.

FIG. 3 shows the results of measuring the characteristics of two defective timing belts after making a prototype of the evaluation system as described above. As is clear from FIG. 3, the spectrum showed the same time-Δ fluctuation characteristics and vibration frequency characteristics as the non-defective product.

These characteristics can be obtained because even if the timing belt is defective, it is possible to suppress abnormal vibrations caused by interference between the two belts and pitch irregularities, tooth profile variations, etc. Conceivable. Note that it can be easily inferred that the same effect can be obtained by using three or more timing belts.

As is clear from these evaluation results, by applying two timing belts 15 and 16 having multiple nine vibrations to the timing pulleys 14 and 7 in the ultrasonic probe, the vibration of the transmission system can be reduced to a steady state. The vibration can be made close to one vibration and the amplitude can be made small.As a result, a defective timing belt with multiple vibrations can be converted into a good product, and synchronous transmission with greatly improved transmission accuracy is possible, which can improve ultrasonic diagnostic images and I was able to eliminate the "shaking". The use of two or more timing belts is thought to lead to an increase in cost, but this could be countered by cutting the normal belt radius in half. As a result, if the conventional cost is 100, it has become possible to reduce it to 30.

Note that by using a timing belt of good quality, it is possible to achieve even higher precision in transmission, which is very effective in technical fields where transmission accuracy is required.

As described in detail, according to the present invention, two or more timing belts with multiple vibrations are applied to the timing belt pulley to transmit power, so the vibration of the transmission system is reduced to a steady single vibration. It is possible to reduce the distance and the amplitude, and as a result, the transmission accuracy can be improved.

In this way, it is possible to improve transmission accuracy even if the timing belt is not of good quality, but it is also possible to easily manufacture the timing belt, resulting in lower costs.

[Brief explanation of the drawing]

1(a) and 1(b) show an example in which the transmission method using a timing belt according to an embodiment of the present invention is applied to an ultrasonic probe, and FIG. 1(a) is a partially cutaway front view, and FIG. (b) is an enlarged cross-sectional view of the main part, Figure 2 is an explanatory diagram of the timing belt transmission characteristic evaluation system, and Figure 3 is the transmission when two timing belts are used as in the above embodiment of the present invention. Figure 4 shows the data obtained by frequency analysis of the vibration of the system.
Figures 5 and 6 are diagrams showing the temporal relationship between the driving-side encoder pulse and the driven-side encoder pulse and the relationship between the rise time differences of the respective pulses measured by the evaluation system shown in the figure. Temporal variation of the pulse rise time difference in the timing belt (
FIGS. 7 and 8 are diagrams showing data obtained by frequency analysis of vibrations of pulse rise time differences in timing belts of non-defective products and defective products, respectively. 7.14...timing boo 9-115.16...
Timing belt. Agent's name: Patent attorney Osamu Koebi Akira 2 people Figure 1 Tsuji times Kazuno Roha 1 N Emi. Biting area 1! Mourning MLA 1991 Procedural Amendments R. 72, 1991

Claims (3)

[Claims] (1) A transmission method using a timing belt, characterized in that two or more timing belts having multiple vibrations are applied to a timing belt pulley to transmit power. (2) The transmission method using a timing belt according to claim 1, wherein the timing belt is made of either rubber or polyurethane. (3) The transmission method using a timing belt according to claim 1 or 2, wherein the timing belt has a core made of either polyester or polyamide fiber.