JPH046014B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] When the temperature inside the device, etc. fluctuates beyond a certain limit with respect to the set temperature, an abnormality signal is generated, the operation of the cooling/heating unit is stopped, and the temperature inside the device, etc. is reduced. The present invention relates to a temperature abnormality monitoring device that prevents the temperature from running out of control.

[Prior art]

FIG. 1 is a sequence diagram showing a conventional device,
This figure will be explained above. 1 is a cooling/heating unit operation switch, 2 is a cooling/heating unit stop switch,
3 is a temperature lower limit detection switch, 4 is a temperature upper limit detection switch, 6 is an upper/lower limit signal relay, and 6a is a relay 6
6b is the B contact of the relay 6, 7 is the operation relay for the cooling/heating unit (not shown), and 7a is the relay 7
8 is the alarm relay, 8a is the a contact of relay 8.
It is a point of contact. The temperature lower limit detection relay 3 is configured to short-circuit the common terminal and the L terminal when the temperature of the detected part exceeds the upper limit of the set temperature, and short-circuit the common terminal and the H terminal in other cases. be. The temperature lower limit detection relay 4 is configured to short-circuit the common terminal and the H terminal when the temperature of the detected part exceeds the lower limit of the set temperature, and short-circuit the common terminal and the L terminal in other cases. .

The H terminal of temperature lower limit detection relay 3 is connected to the common terminal of temperature upper limit detection relay 4, so that both relays 3 and 4 are connected in series. This results in
This series circuit detects that the temperature of the detected part is within the set temperature range and outputs a steady signal that energizes the upper and lower limit signal relay 6. When the temperature of the detected part is outside the set temperature range, the upper and lower limit signal relay 6 is activated. Temperature monitoring means is configured to output an abnormal signal to deenergize the temperature control circuit 6. In the case of FIG. 1, this temperature monitoring means is shown in a state in which it outputs a steady signal. In this state, when operation switch 1 is turned on, switch 2 and contact 8b
Since is closed, operation relay 7 is activated,
A cooling/heating unit (not shown) starts operating. The self-holding contact 7a is closed by the operation of the operation relay 7, and the operation relay 7 continues to operate thereafter. In addition,
In this state, switch 3 is tilted to the H terminal side and switch 4 is tilted to the L terminal side, so relay 6 is energized, contact 6b is open, and relay 8
is inoperative and contact 8b is closed. Here, if the temperature falls outside the set range, either switch 3 or switch 4 is activated depending on whether the temperature exceeds the lower limit or the upper limit. As a result, relay 6 becomes inactive,
Contact 6b closes, and alarm relay 8 constituting stop control means is energized. As a result, contact 8b opens, relay 7 becomes inactive, and the cooling/heating unit is stopped.

FIG. 2 is a diagram showing an example of temperature changes in the detected portion. As shown by temperature change curve B in this figure,
If the cooling/heating unit is started when the temperature is within the upper and lower limits of the set temperature, the above operation will occur. However, as shown in temperature change curve A, if operation is started when the temperature is outside the upper and lower limits, the upper and lower limit signal relay 6 turns OFF, and the alarm relay 8
turns on, issues an alarm signal, and the cooling/heating unit stops, making it impossible to start. Conventionally, to prevent this, the starting switch 5 was connected in parallel with the switches 3 and 4, and kept turned on until the temperature inside the device fell within the upper and lower limit setting ranges. However, with this method, even if the temperature falls within the set upper and lower limits, there is a possibility of forgetting to turn off switch 5, and even if the temperature inside the device falls outside the upper and lower limits, the cooling/heating unit cannot be stopped, leading to the risk of the temperature going out of control. There is.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a temperature abnormality monitoring device that can prevent uncontrollable conditions such as temperature runaway due to forgetting to turn off a switch or the like.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that when the temperature at the time of starting is outside the upper and lower limit setting range, the stop control means is kept inactive until the temperature falls within the range. The reason for this is that it is put into a standby state only after the engine has reached a certain point, and when it is started from within the range, it is put into a standby state from the beginning. Therefore, the present invention includes a signal monitoring means that inputs an abnormal signal to the stop control means only when the output signal from the temperature abnormality monitoring means changes from a steady signal to an abnormal signal.

[Embodiments of the invention]

An embodiment of the present invention shown in FIG. 3 will be described below. In this figure, the same reference numerals as in FIG. 1 indicate the same parts. However, the temperature lower limit detection relay 3 and the temperature upper limit detection relay 4, which constitute the temperature monitoring means, are connected in parallel, and when the temperature is within the set range, a steady signal that deenergizes the upper and lower limit signal relay 6 is sent out. Although this outputs an abnormality signal that energizes the upper and lower limit signal relays 6, they may be connected in series if the same function is achieved. 6a is the a contact point of the relay 6. Reference numeral 9 denotes an alarm standby state relay constituting a holding means which is one of the constituent elements of the signal monitoring means which constitutes the main part of the present invention, and a contact 9a connected to this relay
is one of the a contacts of the relay 9, and performs the self-holding operation of the relay 9. Contact 9a and contact 6b are connected in series, and this series circuit includes switch 1 and contact 7a.
Connect in parallel with Then, contact 6b and contact 9a
The common connection point with the relay 9 is connected to the relay 9. In addition, a relay 9 is included in the alarm relay 8 constituting the stop control means.
The other a-contact 9a and the a-contact 6a of the relay 6 are connected in series as logical product means, and the relay 8 is energized only when both contacts 6a and 9a are both turned on. That is, the contact 9a is the output of the relay 9 as a holding means, and when it is detected that the output signal of the temperature monitoring means changes from an abnormal signal to a steady signal, this steady signal is held, and the temperature is monitored in this state. Only when the output of the means changes from the steady signal to the abnormal signal, the relay 8 as the stop control means is energized. This makes it possible to control the cooling/heating unit from the time of startup without using a means such as a starting switch that ignores the output of the temperature monitoring means based on an external signal.

With this configuration, if the temperature of the detected part changes as shown in the temperature change curve A shown in Figure 2, both the temperature lower limit detection switch 3 and the temperature upper limit detection switch 4 are on the L side at the time of startup. Yes, upper and lower limit signal relay 6 is ON, contact 6b is OFF
Therefore, the temperature monitoring means outputs an abnormal signal. However, since the alarm standby state relay 9 is OFF and the contact 9a is OFF, even if the contact 6a is ON, the alarm relay 8 is not energized and the cooling/heating unit is operated. When the temperature inside the device falls within the upper and lower limit setting ranges from this state, the lower temperature limit detection switch 3 goes to the H side, the upper and lower limit signal relay 6 turns OFF, and the alarm standby state relay 9 is self-held by the contact 9a and the alarm relay 8 is in a standby state. Next, when the temperature inside the device falls outside the upper and lower limit setting ranges, the contact 6a turns ON to issue an abnormal signal and stop the operation of the cooling/heating unit.

In addition, in the case of a temperature change such as temperature change curve B in Fig. 2, the temperature lower limit detection switch 3 is activated at startup.
is on the H side, temperature upper limit detection switch 4 is on the L side,
The upper and lower limit signal relay 6 is OFF, the alarm standby state relay 9 is self-held by the contact 9a, and the alarm relay 8 is in a standby state. Next, when the temperature falls outside the upper and lower limit setting ranges, an abnormality signal is generated and the operation of the heating and cooling unit is stopped, as in the case of temperature change curve A.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the output of the alarm standby state relay is held when the temperature falls between the upper limit value and the lower limit value at the time of startup, and this alarm relay is set. Connect to a series circuit of the first normally open contact of the upper and lower limit signal relay that is energized outside the temperature range and the third normally open contact of the alarm standby state relay, and when the third normally open contact closes, Since it is energized by the closing of the first normally open contact, once the internal temperature of the device falls within the upper and lower limits of the temperature due to a malfunction or the like during startup, it will still be within this range before reaching the set temperature. Even if it is disconnected, an abnormality signal is generated by the operation of the upper and lower limit signal relays, and the operation of the cooling/heating unit can be stopped, making it possible to obtain a temperature abnormality monitoring device with excellent reliability. Furthermore, once a steady state has been reached, the temperature abnormality can be effectively managed, and the operation is automatically executed, making it possible to prevent uncontrollable conditions such as temperature runaway due to forgetting to turn off a switch, etc. can.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a conventional device having a switch for starting, Fig. 2 is a temperature change curve diagram showing an example of temperature change in a detected part, and Fig. 3 is a circuit diagram showing an embodiment of the present invention. . DESCRIPTION OF SYMBOLS 1... Cooling/heating unit operation switch, 2... Cooling/heating unit stop switch, 3, 4... Temperature lower limit detection switch constituting temperature monitoring means, 5... Switch for starting, 6... Upper/lower limit signal relay, 6a... …
6 a contact, 6b...6 b contact, 7...cooling/heating unit operation relay, 7a...7 a contact, 8...
Alarm relay constituting stop control means, 8a...8
A contact of 9, 9...Alarm standby state relay constituting the signal monitoring means, 9a...A contact of 9.

Claims (1)

[Claims] 1 A temperature abnormality monitoring device that controls the stop and start of the cooling/heating unit in response to an abnormal signal that is output when it detects that the set temperature is outside the range defined by the lower limit temperature and upper limit temperature. In devices that are configured to remain inactive until the temperature reaches a predetermined condition, there is a temperature lower limit detection switch that turns on when the temperature is below the lower limit, and one that turns on when the temperature exceeds the upper limit.
an upper and lower limit signal relay that is connected in series to the parallel connection circuit of the temperature upper limit detection switch, has a first normally open contact and a first normally closed contact, and is energized outside the set temperature range; A run/stop switch is formed by connecting in series a stop switch with a normally open contact and an operation switch with a normally open contact, and a second normally open contact and a third normally open contact, and the switch has a stop switch with a normally open contact and a run switch with a normally open contact, and has a second normally open contact and a third normally open contact. Connected to the run/stop switch via the first normally open contact so as to maintain an inoperable state until the temperature passes at least one of the lower limit temperature and the upper limit temperature from outside the range of the upper limit temperature and lower limit temperature. , when the temperature passes through at least one of the lower limit temperature and upper limit temperature from outside the above range to within the above range at the time of starting, the state is energized by the second normally open contact before reaching the set temperature. an alarm standby state relay having a second normally closed contact that connects the first normally open contact and the third normally closed contact;
connected to a series circuit of normally open contacts, and when the third normally open contact is closed, the temperature passes through at least one of the lower limit temperature or upper limit temperature from within the above range to outside the above range. an alarm relay energized by the closing of the first normally open contact;
A temperature abnormality monitoring device comprising an operation relay connected to the operation/stop switch via the second normally closed contact.