JPS6319721B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a servo torque amplifier that uses fluid pressure supplied from a pressure source, and whose output shaft follows the rotation of an input shaft and rotates with high torque. The present invention relates to a safety device for equipment using a servo torque amplifier to prevent unexpected rotation of an output shaft when a pressure source is activated in equipment using a servo torque amplifier.

[Conventional technology]

As is well known, a servo torque amplifier that uses fluid pressure supplied from a pressure source includes a rotary guide valve 2 that rotates in conjunction with an input shaft 1, and a rotary guide valve 2 that rotates in conjunction with an input shaft 1, as shown in FIG. If there is a deviation between the rotary actuator 4 whose output part is connected to the output shaft 3 and the absolute rotational position (angle) of the input shaft 1 and the absolute rotational position (angle) of the output shaft 3, the rotary actuator 4 is rotated until the deviation disappears. , a mechanical feedback mechanism 6 that acts to rotate the output part (i.e., the output shaft 3) of the actuator 4 by the fluid pressure supplied from the pressure source 5, and the input shaft 1 rotates, the output shaft 3 follows the rotation of the input shaft 1 and rotates with high torque. Such servo torque amplifiers have excellent advantages such as high speed, high response, small size, and large output due to their inherently high spatial power density, and are used in many fields, but this type of amplifier is especially The servo torque amplifier has a very large torque-to-inertia ratio, and can perform precise and functional torque control when combined with an electronic control system, making it a popular choice for muscle strength rehabilitation and other fields. It is also attracting attention as a source of resistance torque for training aircraft.

For example, Fig. 2 is a block diagram showing an example of the configuration when the above-mentioned servo torque amplifier is applied to a muscle strength training machine, and the muscle strength training machine shown in this figure can perform so-called isometric training or constant velocity training. It is configured as follows. In this figure, the output shaft 3 of the servo torque amplifier 7 is connected to a muscle force application mechanism 8, such as a handle or pedal, which is rotated by a trainee or the like using muscle power. Further, the rotation of a DC servo motor 9 is transmitted to the input shaft 1 of the servo torque amplifier 7 via a reduction gear train 10 . This DC servo motor 9 is driven by a power amplifier 11, but in this case, its rotation speed is controlled using the output of the voltage amplifier 12 as a target value and the rotation speed of the DC servo motor 9 detected by a tacho generator 13 as a feedback signal. is configured to be The internal setting device 14 is a setting device for setting the target value of the rotational position of the muscle force application mechanism 8 such as a handle or pedal, and the one provided in this muscle training machine and the external setting device 15 are used to set a similar setting. However, the settings can be made from another external control device. A portion consisting of these internal setting device 14 and external setting device 15 is referred to as a setting section 16. Further, the angle detector 17 is a detector that detects the absolute rotational position (angle) of the input shaft 1, and the processing circuit 18 converts the signal output by the angle detector 17 into a voltage signal corresponding to the absolute rotational position of the input shaft 1. This is a circuit that does this.

In the muscle strength training machine having such a configuration, the rotational position of the muscle force application mechanism 8 such as a handle or pedal can be controlled with respect to the target value of the rotational position set in the setting unit 16, This makes it possible to perform isometric training or uniform speed training.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned muscle training machine, when there is a deviation between the absolute rotational position of the input shaft 1 and the absolute rotational position of the output shaft of the servo torque amplifier 7 when the pressure source 5 is stopped, When the pressure source 5 is activated, the output shaft 3
However, due to the fluid pressure, the muscle force applying mechanism 8 such as the handle and pedals is rotated due to the rapid rotation until the deviation is eliminated, which is very dangerous.

This invention was made in view of the above circumstances, and its purpose is to prevent unexpected rotation of the output shaft that may occur when the pressure source is started in equipment using a servo torque amplifier. The object of the present invention is to provide a safety device for equipment using a servo torque amplifier that can be used to improve safety.

[Means for solving problems]

In order to achieve this object, a safety device for equipment using a servo torque amplifier according to the present invention includes a first rotational position display device that detects and displays the absolute rotational position of the input shaft of the servo torque amplifier, and a first rotational position display device that detects and displays the absolute rotational position of the input shaft of the servotorque amplifier. and a second rotational position display device for detecting and displaying the position, and the first and second rotational position display devices are characterized in that they can operate even when the pressure source is not operating.

[Effect]

When the pressure source is inactive, a first rotational position indicator indicates the absolute rotational position of the input shaft of the servo torque amplifier, and a second rotational position indicator indicates the absolute rotational position of the output shaft. If there is no deviation between the two displayed absolute rotational positions, there is no risk of rapid rotation of the output shaft when the pressure source is activated, and on the other hand, if there is a deviation between the two absolute rotational positions, the pressure source It can be detected that there is a danger that the output shaft will rotate rapidly when activated. Therefore,
Accidents caused by rapid rotation of the output shaft when starting the pressure source can be prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment FIG. 3 is a block diagram showing the configuration of the first embodiment when this invention is applied to a strength training machine. In this figure, parts corresponding to those in FIG. 2 are the same. The description thereof will be omitted.
In FIG. 3, the angle detector 17 is constituted by an absolute rotary encoder, and outputs the absolute rotational position of the input shaft 1 as a corresponding code signal. The processing circuit 18 converts this code signal into a corresponding analog signal and outputs it to a summing point 19, and also converts the code signal into a display signal and outputs it to a display 20. in this case,
The angle detector 17, the processing circuit 18, and the display 20 constitute a first rotational position display device 21. Next, the angle detector 22 is also constituted by an absolute rotary encoder, and outputs the absolute rotational position of the output shaft 3 as a corresponding code signal. The processing circuit 23 converts this code signal into a display signal and outputs it to the display 24. In this case, the angle detector 22, the processing circuit 23, and the display 24 constitute a second rotational position display device 25. And these rotational position display devices 2
1 and 25 can be operated by supplying power from a power source (not shown) even when the pressure source 5 is inactive.

In the above configuration, before using this muscle training machine, the trainer etc. turns on the power to the rotational position display devices 21, 25, etc. (including the control circuits other than the pressure source 5) before starting the pressure source 5. do. Then, the absolute rotational angle of the input shaft 1 is detected by the angle detector 17, and a code signal corresponding to the absolute rotational position of the input shaft 1 is output from the angle detector 17. This code signal is converted into a display signal by the processing circuit 18 and supplied to the display 2, whereby the absolute rotational position of the output shaft 1 is displayed on the display 20.
At the same time, the absolute rotational position of the output shaft 3 is detected by the angle detector 25.
A code signal corresponding to the absolute rotational position of the output shaft 3 is output from. This code signal is transmitted to the processing circuit 23.
The signal is converted into a display signal and supplied to the display 24, whereby the absolute rotational position of the output shaft 3 is displayed on the display 24.

Therefore, the trainee checks whether there is a deviation between the absolute rotational positions of the input shaft 1 and the output shaft 3 displayed on the displays 20 and 24, respectively. If there is a deviation, check the muscle force applying mechanism 8 of the handle, pedal, etc. while watching both the indicators 20 and 24.
The output shaft 3 is rotated until the deviation disappears. Note that when the deviation disappears, the rotary guide valve 2 becomes in a neutral state and the output shaft 3 stops rotating. When the deviation disappears, the pressure source 5 is activated. In this way, even if fluid pressure is supplied to the servo torque amplifier 7, there will be no deviation in absolute rotational position between the input shaft 1 and the output shaft 3, so the output shaft 3 will not rotate unexpectedly. .

Second Embodiment Next, a second embodiment in which the present invention is applied to a muscle strength training machine will be described. FIG. 4 shows a muscle strength training machine in which the position of the output shaft 3 is controlled using the absolute rotational position of the output shaft 3 as a target value and the absolute rotational position of the input shaft 1 as a feedback amount. In this figure, the angle detector 17 has an incremental rotary encoder and a counter that counts and stores the output of the incremental rotary encoder. Here, the incremental rotary encoder detects the rotation of the input shaft 1 and outputs a forward rotation pulse A corresponding to the amount of forward rotation when the input shaft 1 rotates in the normal direction, while when the input shaft 1 rotates in the reverse direction outputs a reversal pulse B according to the amount of reversal,
Further, when the input shaft 1 is at the reference position, an origin signal Z is output. The counter receives the origin signal Z
When is supplied, the counted value is cleared to zero, and when forward pulse A is supplied, the counted value is incremented, and when reverse pulse B is supplied, the counted value is decremented. Therefore, the absolute rotational position of the input shaft can be known from this count value. These incremental rotary encoders and counters are designed to be powered by a backup power source such as a battery (not shown) even if the power to the muscle training machine is cut off. From this angle detector 17, the count value of the counter is transmitted to the input shaft 1.
is output as a code signal corresponding to the absolute rotational position. The processing circuit 18 converts this code signal into a corresponding analog signal and outputs it to the summing point 19, and also converts the code signal into a display signal and outputs it to the display 20. The angle detector 22 similarly includes an incremental rotary encoder and a counter for counting and storing the output thereof, and is also supplied with power from a backup power source. This angle detection circuit 22 outputs a code signal corresponding to the absolute rotational position of the output shaft 3. The processing circuit 23 converts this code signal into a corresponding analog signal and supplies it to the summing point 19, and also converts the code signal into a display signal and supplies it to the display 24. The pressure source 5 is connected to the rotation position display device 2 by a power switch (not shown).
Power can be supplied independently from 1, 25 and other control circuits.

That is, in this muscle strength training machine, for example, a trainee assumes that both the input shaft 1 and the output shaft 3 are at the absolute rotation position (the point at which the incremental rotary encoder forming the angle detectors 17 and 22 outputs the origin signal Z). When the handle 8 is rotated by an angle of X degrees in the forward direction from this state, the mechanical feedback mechanism 6 causes the rotary guide valve 2 to rotate the output shaft 3 in the reverse direction by an angle of X degrees to return it to its original state. At the same time, the reaction force of the fluid pressure acting on the trainee through the rotary guide valve 2 to reverse the rotary actuator 4 acts as a load (torque). This load (torque) acting on the trainee is
The larger the angle X° of the handle 8, the larger the angle becomes.

On the other hand, the angle X° of the handle 8 is measured by the angle detector 2.
2 and then outputted to the summing point 19 via the processing circuit 23. With this output, the input shaft 1, which is still in the absolute rotational position, is rotated by X° by the DC servo motor 9. Then, the rotary guide valve 2 also rotates by X°, so
The amount of feedback that was acting up until then (-X)
are canceled out and become 0, and as a result, no load is applied to the handle 8.

Then, when the trainee further rotates the handle 8, the above-mentioned operation is repeated instantaneously and continuously, and as a result, the trainee always sees the handle 8.
Load (torque) according to the force trying to rotate
will come into play. Therefore, with this muscle strength training device, training can be performed using a load (torque) that corresponds to the muscle strength of the trainee.

In the above configuration, a trainee or the like turns on the power to the rotational position display devices 21 and 25 before starting the pressure source 5 before using this muscle training machine.
The counters of the angle detectors 17 and 22 are backed up by batteries or the like, and the coefficient values at the time of power cut-off are held in the counters. When the power is turned on, the coefficient value of the counter of the angle detector 17 is output as a code signal, and this code signal is converted into a display signal by the processing circuit 18 and supplied to the display 20. As a result, the absolute rotational position of the output shaft 1 is displayed on the display 20. At the same time, the coefficient value of the counter of the angle detector 22 is output as a code signal, and this code signal is converted into a display signal by the processing circuit 23 and displayed on the display 2.
4. As a result, the absolute rotational position of the output shaft 3 is displayed on the display 24.

The trainee enters the display on the display devices 20 and 24, respectively, and is displayed on the display devices 20 and 24, respectively. Check whether there is any deviation between the absolute rotational positions of the input shaft 1 and the output shaft 3. If there is a deviation, use one of the following two methods to eliminate this deviation. The first method is to rotate the force applying mechanism 8 such as a handle or pedal to rotate the output shaft 3 until the deviation disappears. In the second method, all control circuits except the pressure source 5 are powered on. In this way, the output shaft 3
Since the position of the input shaft 1 is controlled by being driven by the DC servo motor 9 using the absolute rotational position as the target value, the deviation is eliminated. If the pressure source 5 is activated after confirming that the deviation has disappeared in this way, the output shaft 3 will not rotate unexpectedly.

〔Effect of the invention〕

As explained above, according to the safety device for equipment using a servo torque amplifier according to the present invention, even when the pressure supply source is not operating, the absolute rotational positions of the input shaft and output shaft of the servo torque amplifier can be controlled. Can be detected and displayed. Therefore, based on these display contents, it is possible to operate the pressure supply source after eliminating the deviation in the absolute rotational position between the input shaft and the output shaft. This makes it possible to prevent unexpected rotation of the output shaft that may occur during startup, ensuring operational safety. Further, according to the present invention, even when the servo torque amplifier is operating, it is possible to check the absolute rotational positions of the input shaft and output shaft, so the operation of the servo torque amplifier and its control circuit can be confirmed. Also useful for confirmation.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a servo torque amplifier, Fig. 2 is a block diagram showing an example of the configuration of a muscle strength training machine to which the servo torque amplifier is applied, and Fig. 3 is a diagram showing the structure of a muscle strength training machine when this invention is applied. FIG. 4 is a block diagram showing the structure of the first embodiment, and FIG. 4 is a block diagram showing the structure of the second embodiment when the present invention is applied to a muscle strength training machine. DESCRIPTION OF SYMBOLS 1... Input shaft, 2... Guide valve (rotary guide valve), 3... Output shaft, 4... Actuator (rotary actuator), 5... Pressure source, 6... Mechanical feedback mechanism, 7... Servo torque amplifier, 8... Muscle force application mechanism (handle, pedal, etc.), 21... First rotational position display device, 25
...Second rotational position display device.

Claims (1)

[Claims] 1. A guide valve connected to an input shaft, an actuator connected to the output shaft whose output part drives a load, and a displacement of the guide valve by fluid pressure supplied from a pressure source. A first rotational position display device for detecting and displaying the absolute rotational position of the input shaft in a device using a servo torque amplifier having a mechanical feedback mechanism that causes the output portion of the actuator to follow the output portion of the input shaft; and a second rotational position display device that detects and displays the absolute rotational position of the output shaft, and the first and second rotational position display devices can operate even when the pressure source is not operating. A safety device for equipment using a servo torque amplifier characterized by the following. 2. Using the servo torque amplifier according to claim 1, wherein at least one of the first and second rotational position display devices detects the rotational position using an absolute rotary encoder. Safety equipment for equipment that was used. 3. At least one of the first and second rotational position display devices constantly supplies power to an incremental rotary encoder, a count storage section for the output of the incremental rotary encoder, and the incremental rotary encoder and the count storage section. 3. A safety device for equipment using the servo torque amplifier according to claim 1 or 2, characterized in that the device has a power source capable of controlling the servo torque amplifier.