JPS58149597A - Apparatus for measuring mechanical quantity - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to mechanical quantities to be measured, in particular forces, displacements, revolutions, angles, and impacts obtained with a sensor using a piezoceramic body. The present invention relates to a mechanical quantity measuring device in which a signal is transmitted via a transmission line to a measured value output device including an amplifier.

[Prior art and its problems]

Mechanical quantities can be measured electrically in a known manner. In this case, the mechanical measurement quantity is converted into an electrical measurement signal, resulting in changes in electrical resistance and capacitance.

Inductance change and electrical polarization change (piezo effect)
is utilized and current or voltage changes are indicated and recorded. If the detection location and the instruction recording location are far apart, it is necessary to transmit the measured values remotely, and the measured values present as electrical signals must be amplified beforehand! must be transmitted over an electrical conductor of the required length.

In these known methods, the characteristics of the signal transmission path influence the measurement signal. Additionally, ambient conditions around the transmission path, such as outside temperature, electric fields, and magnetic fields, can distort the measured signal. Furthermore, it is necessary to supply electrical energy to the electrical components of the amplifier located at the detection location.

In many cases, a power supply is not available at the detection site, so batteries have to be used, and continuous monitoring of mechanical quantities requires battery maintenance.

[Purpose of the invention]

It is an object of the present invention to provide a device for measuring force, displacement, rotational speed, angle, or impact that does not require the installation of an amplifier at the detection location, and that the measurement signal can be transmitted by changes in outside temperature and by the effects of magnetic and electric fields during transmission. The purpose of the present invention is to provide a measuring device that is free from the possibility of harmful effects.

[Summary of the Invention] This object is achieved according to the invention in a measuring device of the type mentioned at the outset, in which the electrical output of the piezoceramic body is connected to a light-emitting diode, and at least one light guide is provided at the light output point of the piezoceramic body. This is achieved in that the end is arranged and the light guide is guided to a measured value output device, where the transmitted optical signal is converted into an electrical quantity and amplified and fed to an indicating or recording device. be done.

The device according to the invention has the advantage that it is not necessary to supply electrical energy to the detection location and that no battery maintenance is required for continuous monitoring of mechanical quantities. Furthermore, no compensation circuit is required at the detection location, and transmission can be carried out over distances of several kilometers via a simple transmission path using a light guide, which is virtually unaffected by external influences.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows a device used for force, pressure, displacement or angle limit value alarms. Case 1 as a sensor
A piezoceramic body 2 with a size of There is. The light emitting diode 5 and the end of the light guide 6 are arranged in a closed case 7. A piezoceramic body 2 is mounted inside the case 1. The action of the force F on the structural member (beam) 8 to be monitored causes a displacement, which causes the rod 9 to move upwards, so that the spring 10 is tripped and impinges on the piezoceramic body 2 . A voltage is generated in the piezoceramic body 2, which is extracted from the electrodes 3, 4 and applied to the light emitting diode 5, so that the light emitting diode emits light. The optical signal emitted in this way is transmitted to the measurement value output device 1 several kilometers away without being amplified.
1 and there it is converted into an electrical quantity. that time,
The optical signal emerging from the end 6b of the light guide 6 is received by the photodiode 12 and transmitted via the amplifier 13 to the
or) given to the recording device. In this example, an optical display board 14 and (still) a buzzer 15 are used as indicating devices.

In the tachometer shown in Figure 2, the pin 17 or protrusion provided on the rotating shaft 16 (5) is a piezoelectric sensor.
- It acts on the spring 10 associated with the lamic body 2, causing the spring 10 to collide with the piezoceramic body 2 every rotation. The number of collisions is recorded in a recording device 18, from which the number of revolutions is known.

The angle needle shown in FIG. 3 operates on the same principle as the device of FIG. 2, but the rotation axis 16 is provided with a plurality of pins 17 or protrusions. In order to measure the angular values in two directions, a second device consisting of parts 2, 7 and 10 is provided.

In FIG. 4, a device for counting impacts of any kind is shown, the impacts acting on the rod 19.

The rod 19, which is held in position relative to the piezoceramic body 2 by the spring force, transmits the impulse to the piezoceramic body 2, which is supported in the tube 21 on a spring n.

The impact is recorded on the recording device 18.

This elastic support can also be used in devices for measuring forces, displacements, angles and rotational speeds. This elastic support prevents premature damage to the one-piece ceramic body.

(6) [Effects of the Invention] As explained above, in the present invention, the electrical output of the piezoceramic body is connected to the light emitting diode, and when the piezoceramic body receives various mechanical amounts, the light emitting diode is connected to the light emitting diode. Since the light is emitted at the detection point of the target amount and the signal is optically transmitted via a light guide to an indicating or recording location remote from the detection point, it is not necessary to provide a power source or an amplifier at the detection point. There is no need to change the settings at all.
Furthermore, there is no risk that the signal will be affected by outside temperature or electromagnetic fields during transmission. As is well known, piezoceramic bodies produce large electrical outputs, especially when subjected to mechanical shock, which causes light-emitting diodes to emit light with sufficient intensity to be transmitted over long conductor transmission lines. , force and displacement are at their limits.

When used in applications where the rotation speed and angle are transmitted digitally in the form of repeated optical pulses to an instruction or storage device located at a remote location, the operation is reliable and can be performed using conventional electrical signal transmission. It has the advantage that the detector and transmission means are much simpler and cheaper than other methods.

[Brief explanation of the drawing]

Figure 1 is a principle diagram of a device used for force, pressure, displacement, or angle limit value alarms; Figure 2 is a principle diagram of a tachometer;
The figure is a diagram of the principle of an angle meter, and FIG. 4 is a diagram of the principle of a device for counting the number of impacts. 1... Case, 2... Piezo ceramic body, 3, 4
...Electric output end, 5...Light emitting diode, 6...
Light guide, 6a, 6b... Guide body end, 7... Case, 8... Beam, 9... Bar, 10... Spring, 11
...Measurement value output device, 12...Photodiode,
13... Amplifier, 14... Optical display board, 15... Buzzer, 16... Rotating shaft, 17... Pin, 18...
Recording device, 19...rod, 20...spring, 21...
Tube, n...spring. Agent Iwao Yamaguchi

Claims (1)

Claims: 1) Mechanical quantities to be measured, in particular forces, displacements, and rotational speeds. An angle switch is a mechanical quantity measuring device in which a signal obtained by a sensor using a piezoceramic body in relation to an impact is transmitted via a transmission line to a measured value output device equipped with an amplifier. The electrical output end of the light emitting diode is connected to the light-emitting diode, and the end of at least one light conductor is arranged at the light output point, and this light conductor is led to a measured value output device and receives the transmitted optical signal there. An apparatus for measuring a mechanical quantity, characterized in that the quantity is converted into an electrical quantity, amplified, and applied to an indicating device or a recording device. 2. Measuring a mechanical quantity in the device according to claim 1, characterized in that a light emitting diode and an end portion of a guide attached thereto are also housed in the case housing the piezoceramic body. Device. 3) A measuring device for a mechanical lid, as claimed in claim 1 or 2, characterized in that the piezoceramic body is supported under elastic action.