JPH0327367Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a germination machine that automatically performs a series of steps to germinate rice seeds, that is, sterilizes the rice seeds, soaks the seeds, and germinates the seeds. The heater that maintains the hot water at a predetermined temperature is
This invention relates to a heater protection device for preventing high temperature deterioration or burnout when water circulation is interrupted.

Conventional technology Conventionally, a heater tank (heater tube) is used, which has a container that stores hot water and soaks the seed rice, and a heater that heats the circulating water in the hot water circulation path that circulates the hot water from the bottom of the container to the shower on the top. ), as described in Japanese Utility Model Publication No. 55-25210 and Publication No. 61-29213,
Already known. In addition, this type of germinator is equipped with a float switch in the heater tank that is activated by circulating water in order to prevent the heater from deteriorating at high temperatures or burning out when the water circulation is interrupted. This is also stated in the same bulletin.

Problems that the invention aims to solve By the way, in conventional germ generators such as those mentioned above, the circulating water often causes convection within the heater tank, which causes the float switch to vibrate and repeat intermittent cycles, causing the heater protection circuit to fail. Not only will the relay contacts etc. of the device be worn out and burned out in a short period of time, but
Since this type of heater has a large power capacity, it is frequently turned on and off, causing fluctuations in the power supply voltage. It may also have a negative effect on peripheral devices.

In view of these problems with conventional devices, the present invention detects when the circulating water flowing in the heater tank causes convection and the float switch repeatedly switches on and off, and protects the heater. By keeping the circuit on,
It prevents damage to the heater protection circuit and fluctuations in power supply voltage caused by repeated turning on and off of the heater, and prevents damage to the automatic control system of the germ generator as well as
It is an object of the present invention to provide a heater protection device for a germination machine that does not have any adverse effects on other peripheral equipment.

Means for Solving the Problems The present invention has the following technical means for achieving its purpose.

That is, the heater protection device in the germination machine according to the present invention heats circulating water in a container that stores hot water to soak the rice seeds, and in a hot water circulation path that circulates hot water from the bottom of the container to the shower on the top surface. In a germination machine equipped with a heater tank having a built-in heater, a float switch is provided in the heater tank, which closes when water circulates and opens when water circulation is interrupted, and the float switch turns on and off the heater. The heater protection circuit is characterized by comprising a heater protection circuit for controlling the heater protection circuit, and a malfunction prevention circuit for detecting the disconnection of the float switch due to the convection of water generated in the heater tank and keeping the heater protection circuit in the on state. It is.

Function When the circulating water causes convection in the container that stores hot water and soaks the rice seeds, and the heater tank that is installed in the hot water circulation path that circulates hot water from the bottom of the container to the shower on the top, the water inside the heater tank The float switch is repeatedly intermittent, but
That condition is sensed in the anti-malfunction circuit and the heater protection circuit is held on.

Therefore, if the circulating water is flowing in the heater tank, even if the circulating water causes convection in the heater tank, the heater will remain on regardless and the circulating water will be heated normally. action takes place.

Example Embodiments of the present invention will be explained with reference to the drawings.

In FIGS. 1, 2, and 3, reference numeral 1 denotes a germination machine, and this germination machine 1 is composed of a container 2 with an open top and a control section 3 attached thereto. The container 2 is for storing hot water and soaking the seed rice, and a drainboard 4 is laid on the bottom of the container 2, and a compartment 5 is formed at the bottom of the drainboard.
A shower pipe 6 is installed on the upper side of the container 2, and a plurality of shower heads 7 are provided on the shower pipe 6 at appropriate intervals. The control unit 3 also includes a pump 8 at the bottom thereof.
However, a heater tank 9 is provided at the top of each. A suction pipe 10 connected to the compartment 5 at the bottom of the container 2 is connected to the suction side of the pump 8, and a pump pipe 11 communicates between the discharge side of the pump 8 and the bottom of the heater tank 9. Furthermore, a shower pipe 6 is connected to the top of the heater tank 9, forming a hot water circulation path that circulates hot water from the bottom of the container 2 through the heater tank 9 to the shower on the top of the container 2. .

As shown in detail in FIG. 3, a U-shaped heater 12 is built in the heater tank 9 provided in the middle of the hot water circulation path, and a float switch 13 is provided. This float switch 13 is constructed by attaching a float 16 in which a magnet 15 is embedded so that it can move up and down to a vertical pipe 14 hanging down from the top surface of the heater tank 9, and a reed switch 17 corresponding to the float 16 inside the vertical pipe 14. When water circulates in the heater tank 9, the float 16 rises and closes the reed switch 17, and when the circulating water stops, the float 16 descends and opens the reed switch 17. . 18 and 19 are float 16
This is a stopper that restricts the range of vertical movement. A thermistor 20 is provided at the lower end of the vertical pipe 14, and this thermistor 20 is for detecting the temperature of circulating water heated by the heater 12 in the heater tank 9.

As shown enlarged in FIGS. 4 and 5, the control panel 21 of the control section 3 has a set water temperature display section 22 on the left side that digitally displays the set water temperature.
A current water temperature display section 23 for digitally displaying the current water temperature detected by the thermistor 20 is provided on the right side thereof. Under the set water temperature display section 22, push buttons 24 and 25 are provided corresponding to each digit to individually increment or decrement each numerical value by one. 26 is a clear button for clearing the set value. Note that the control panel 21 includes operating procedures,
Various display sections 27, 28, and 29 are provided for displaying precautions for use and the like.

FIG. 6 shows an example of a control circuit built into the control section 3. That is, the water pump 8
is connected to a power source (AC100V or AC200V) via an earth leakage breaker 30 that also serves as a main power switch, and the temperature of the hot water to be circulated is set, and the heater 12 is turned on and off to turn on and off the hot water. Electric power is also supplied to a control circuit 31 that maintains the temperature at a set value and protects the heater 12 via the earth leakage breaker 30. The heater 12 is connected to the output side of the earth leakage breaker 30 via a relay contact 32 of a relay controlled by a control circuit 31. 33 is a water temperature setting circuit, 34 is a current water temperature display circuit, and the display (LED) 35 of the set water temperature display section 22 and current water temperature display section 23 is displayed by the water temperature setting circuit 33 and the current water temperature display circuit 34. It is driven. Push buttons 23, 24 and clear button 2
6 are connected to the water temperature setting circuit 33, respectively. The thermistor 20 is connected to the control circuit 31, and the reed switch 17 of the float switch 13 is connected to the thermal reed switch 36.
are connected in series. This thermal reed switch 36 is a safety switch that opens when the water temperature rises abnormally. In the control circuit 31, when the reed switch 17 of the float switch 13 is closed, the relay contact 32 closes to turn on the heater 12, and when the circulating water rises to the set water temperature, the relay contact 32 opens and the heater 12 is turned on.
The heater tank 9
Even when the reed switch 17 of the float switch 13 is opened due to the interruption of circulating water within the tank, the relay contact 32
A heater protection circuit 37 is configured to open the heater 12 and turn off the heater 12. The heater protection circuit 37 also includes a circuit 38 for preventing malfunction when the float switch 13 causes convection of circulating water in the heater tank 9 and the reed switch 17 is repeatedly turned on and off. That is, this malfunction prevention circuit 38 senses the phenomenon in which the reed switch 17 of the float switch 13 is interrupted by the convection of circulating water, and operates to keep the relay contact 32 controlled by the heater protection circuit 37 in the ON state. It is. The control circuit 31 is backed up to retain the data even after the power is turned off, but in order to turn off the display 35 after the power is turned off, when the reed switch 17 of the float switch 13 is opened, The circuit configuration is such that the display drive is stopped. That is, as shown in FIG. 7, when the reed switch 17 of the float switch 13 is closed, the display 35 is driven to display after a certain time t' delay, and when the reed switch 17 is opened, the display is driven with a certain time t delay. The display drive is then stopped. Therefore, even if the reed switch 17 causes convection of the circulating water in the heater tank 9 and is repeatedly turned on and off, the display on the display 35 will not change.

In the germination machine 1 configured as described above, in order to disinfect, soak, and germinate the rice seeds, the container 2 is filled with an appropriate amount of water and the rice seeds stored in the net-shaped rice bag.
A predetermined water temperature is set for each process of disinfection, seed soaking, and germination. The water in the container 2 is circulated from the bottom of the container 2 through the heater tank 9 to the shower on the top, and during the circulation, the water is heated to the heater 12 in the heater tank 9. As a result, the water is heated and maintained at a predetermined temperature.

By the way, hot water circulating as described above often causes convection within the heater tank 9. When this phenomenon occurs, the float 16 of the float switch 13 moves up and down, and the reed switch 17 repeats the on/off operation, but the heater protection circuit 34 detects the on/off of the reed switch 17 and turns on the heater 12. Since the malfunction prevention circuit 38 is provided, the heater 12 continues to be in the ON state even in this case, and the normal heating operation is performed. Therefore, it is possible to prevent damage to the heater protection circuit 37 and fluctuations in the power supply voltage caused by repeated turning on and off of the heater 12, and prevent damage to the automatic control system of the germ generator 1 as well as other peripheral devices. There is no negative effect on the product, and stable usage can be maintained at all times. When the reed switch 17 is opened and a certain period of time T has elapsed, the heater protection circuit 37 is turned off, the relay contact 31 is opened, and the heater 12 is turned off, preventing high-temperature deterioration and burnout. (See Figure 8).

In addition, in the device according to the present invention, as described above, the reed switch 1 of the float switch 13
Even if 7 is repeatedly interrupted due to the convection of circulating water, malfunction can be reliably prevented. However, in order to prevent the float 16 of the float switch 13 from moving up and down in the heater tank 9, the steps shown in FIG. In this way, an umbrella 39 covering the float 16 may be provided as an upper stopper of the vertical pipe 10 to prevent the descending water flow due to the convection of circulating water from reaching the float 16. The protrusions 40 are formed so that they do not come into close contact with each other. In addition, as shown in FIG. 10, the float 1
Even with a configuration in which a guide body 41 for circulating water surrounding the float 16 is provided, an effect of preventing vertical movement of the float 16 due to convection of the circulating water can be expected. In addition, the umbrella 39 and the guide body 41 are made of non-magnetic material,
The reed switch 17 of the float switch 13 is prevented from malfunctioning.

Effects of the invention As mentioned above, the present invention includes a container that stores hot water to soak the rice seeds, and a heater that heats the circulating water in the hot water circulation path that circulates the hot water from the bottom of the container to the shower on the top. In a germination machine equipped with a built-in heater tank, a float switch is provided in the heater tank, which closes when water circulates and opens when water circulation stops, and the float switch turns on and off the heater. In addition to configuring a protection circuit, it also includes a malfunction prevention circuit that detects the disconnection of the float switch due to water convection occurring within the heater tank and keeps the heater protection circuit in the ON state. Even if the circulating water causing convection causes the float switch to repeatedly turn on and off, it will sense this and keep the heater protection circuit in the on state, causing the heater to repeatedly turn on and off. It is possible to prevent damage to the heater protection circuit and fluctuations in the power supply voltage, and there is no negative effect on the automatic control system of the germ generator or other peripheral equipment, and stable operation can be maintained at all times. You can get the desired effect.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is an overall side view with a part of the germinator cut away, Fig. 2 is an overall perspective view of the germinator, and Fig. 3 is an enlarged view of the heater tank. 4 is a perspective view showing the control panel portion of the control unit; FIG. 5 is an enlarged front view of the same as above;
Figure 6 is a control circuit diagram, Figure 7 is a time chart showing the control operation of the display, Figure 8 is a time chart showing the malfunction prevention operation of the heater protection circuit, and Figures 9 and 10 are the convection of circulating water. FIG. 3 is a longitudinal cross-sectional view showing an example of a configuration for preventing vertical movement of a float switch due to the movement of the float switch. 1... Germinator, 2... Container, 3... Control unit, 4
... drainboard, 5 ... compartment, 6 ... shower pipe, 7 ... shower head, 8 ... water pump,
9... Heater tank, 10... Water suction pipe, 1
1... Lifting pipe, 12... Heater, 13...
Float switch, 14... Vertical pipe, 15...
...Magnet, 16...Float, 17...Reed switch, 18, 19...Stopper, 20...
... Samister, 21 ... Control panel, 22 ... Set water temperature display section, 23 ... Current water temperature display section, 24,
25...Push button, 26...Clear button, 2
7, 28, 29...Various display parts, 30...Earth leakage breaker, 31...Control circuit, 32...Relay contact,
33...Water temperature setting circuit, 34...Current water temperature display circuit, 35...Display, 36...Thermal reed switch, 37...Heater protection circuit, 38
...Malfunction prevention circuit, 39...Umbrella, 40...Protrusion, 41...Guiding body.

Claims (1)

[Scope of utility model registration request] In a germination machine that is equipped with a container that stores hot water and soaks the rice seeds, and a heater tank that has a built-in heater that warms the circulating water in the hot water circulation path that circulates the hot water from the bottom of the container to the shower on the top surface, A float switch is provided in the heater tank, which closes when water circulates and opens when water circulation stops, and this float switch constitutes a heater protection circuit that turns on and off the heater, and also prevents the 1. A heater protection device for a germination machine, comprising a malfunction prevention circuit that detects disconnection of a float switch due to water convection and keeps the heater protection circuit in an on state.