JPH0453538Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to an automatic balancing recorder used, for example, to record the internal temperature of a marine container refrigeration system, and is particularly useful for recording changes in process quantities. This invention relates to an improvement in an automatically balanced recorder that uses a servo mechanism to clearly record the state when the servo mechanism is in a powerless state such as a power outage.

[Conventional technology]

Conventionally, a self-balancing temperature recorder used in a marine container refrigeration system is constructed as shown in FIG. The recorder shown in Figure 2 has a temperature detection end.
The change in the resistance value of TH is converted into a voltage, and the resistance value of the potentiometer 9 fixed to the shaft of the gear 7 is converted into a voltage, and the difference between the two voltages is supplied to the amplifier 1. The output of this amplifier 1 is supplied to a servo motor 2, and the rotation of the servo motor 2 is controlled in accordance with the output of the amplifier 1. When the servo motor 2 rotates, the connecting gears 3, 4, 5, 6, and 7 rotate, and the potentiometer 9 fixed to the shaft of the gear 7 rotates, so that the input to the amplifier 1 becomes zero, that is, the output becomes zero. Rotate until it rotates. A recording pen 11 fixed to the shaft of a fan-shaped gear 8 connected to the gear 7 similarly moves, and a trajectory is recorded on the recording paper 13 by the pen tip 12. That is, the scale at the position of the locus recorded by the recording pen 11 on the recording paper 13 always indicates the measured temperature.

On the other hand, the recording paper 13 is rotated at a predetermined speed by a spring clock (a quartz clock in other examples) 14, and the temperature of the process corresponding to each time can be recorded.

Now, if the power is cut off due to a power outage or the like, the power to the servo motor 2 will be cut off, and the recording pen 11 will stop at the position immediately before that. Recording pen 1 even when the process temperature changes
1 does not move, and on the other hand, the recording paper 13 rotates due to the drive of the spring clock 14, so that the temperature immediately before the power outage is continuously recorded during the power outage period.

This presents a disadvantage when process temperature recording data is a critical requirement for transactions. For example, in the refrigerated container transportation industry, the most important transaction requirement is temperature control during the entire transportation process of the transported cargo (load) between the refrigerated container shipper and the carrier (shipping company). As proof of that,
Since we use the recording paper from the temperature recorder inside the refrigerated container, during power outages (during hoisting and unloading between the terminal and ship or land transport using a trailer without a generator),
Even though the refrigeration equipment has stopped and is not being cooled, it is recorded as if the predetermined temperature is being maintained, which can cause trouble in transactions.

[Problem that the invention attempts to solve]

The present invention was developed to solve the above problem, and its purpose is to detect when the power to the servo circuit is cut off due to a power outage, etc., and move the recording pen out of the recording scale range (in the maximum direction or minimum direction). ) to prevent improper recording during power outages.

[Means for solving problems]

The present invention has a configuration in which the recording pen can be shaken off in the event of a power outage. At this time, a large capacity capacitor is provided as a recording pen drive means for operating the servo mechanism or the recording pen to move the recording pen out of the recording scale range of the recording paper in the event of a power outage in the power supply circuit. It is possible to charge the servo motor and use the discharge current to drive the servo motor during a power outage, allowing the recording pen to swing out. Alternatively, a rechargeable battery is provided as a dedicated power source and is constantly charged, and this battery can be used to drive the servo motor in the event of a power outage. A structure that allows the recording pen to swing out by rotating it, or a structure in which a spring is attached to the recording pen, and the recording pen is normally driven with a force stronger than this spring, and in the event of a power outage, this spring swings the recording pen in the direction of tension. It can be either.

〔Example〕

An embodiment of the present invention is shown in FIG. In FIG. 1, when power is normally supplied from the power supply circuit 10, the contact 16 of the relay is tilted to the left in the figure (the position shown by the broken line), and the output of the amplifier 1 is supplied to the servo motor 2. Record temperature successfully. Now, if a power outage occurs, the power outage detection relay 15 will return to its normal state, and the contact 16 will fall to the right in the figure (solid line position), and the charge accumulated in the capacitor C of the pen drive circuit 17 at the time of a power outage will pass through the resistor R4 to the servo motor. 2, and the servo motor 2 is rotationally driven. This motor drive moves the recording pen to the outside of the minimum scale position, scaling out the recording at the time of a power outage.

[Effect of idea]

As described above, according to the present invention, the power outage condition is clearly recorded during a power outage without continuously recording the temperature just before the power outage. In the transportation industry, the reliability of recorded data (recording paper) between shippers and carriers (shipping companies) will be greatly improved, and problems surrounding recorded data will be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing the configuration of essential parts as an embodiment of the present invention, and FIG. 2 is a diagram showing the configuration of a conventional automatic balancing recorder. 1...Amplifier, 2...Servo motor, 10...
Power supply circuit, 15... Power outage detection relay, 16... Power outage detection relay contact, 17... Pen drive circuit during power outage.

Claims (1)

[Scope of utility model registration request] It has a servo mechanism driven via a power supply circuit, and a recording pen operated by the servo mechanism, and the recording pen records changes in the process amount to a non-electric drive mechanism independent from the power supply circuit. In a self-balancing recorder that records on a rotating recording paper, the servo mechanism or recording pen is connected to the servo mechanism or the recording pen, and when the power supply circuit is out of power, the servo mechanism or the recording pen is activated to move the recording pen to the recording paper. An automatic balance type recorder, characterized in that it is equipped with a recording pen drive means for moving the recording paper out of the recording scale range during a power outage.