JPS6313086B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a combustion device, particularly a temperature control device for a gas stove.

Conventional technology As a means of controlling the gas amount of a combustion device that burns gas fuel, a so-called on-off solenoid valve is installed in the middle of the gas supply pipe leading to the gas burner, and the gas flow rate is set to maximum or stopped, or the gas flow rate is set to maximum or stopped. There were so-called high-low solenoid valves that switched between flow rates and proportional control solenoid valves that changed the flow rate continuously from the maximum flow rate to the minimum flow rate by changing the current value.

Problems to be Solved by the Invention However, when these are applied to the temperature control of a gas stove, the on-off solenoid valve causes large temperature fluctuations of the object to be heated, resulting in poor cooking performance. Also, although the high-low solenoid valve has better cooking performance than the on-off type, it is still not sufficient. Furthermore, multi-stage control becomes expensive. In addition, the proportional control solenoid valve is configured to vary the gas passage resistance with the valve body, so in appliances with a low combustion rate such as a gas stove, the gas volume will immediately reach full combustion as soon as the valve is slightly opened, especially for propane gas etc. In some cases, this became even more severe, making it difficult to maintain control stability.

Means for Solving the Problems In order to solve the above problems, the present invention does not vary the gas passage resistance, but controls gas pressure regulation. For this purpose, the valve installed in the gas passage is made movable by a diaphragm, a pressure regulating spring is provided on this diaphragm, and a motor is used as a means of changing the gas pressure regulating set value by changing the strength of this pressure regulating spring. It was established.

Function: With the above means, the pressure of the gas governor can be made stronger or weaker by rotating the motor by remote control, and the temperature of the object to be heated can be automatically controlled by varying the thermal power of the burner.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention in the form of a control system diagram. 1 is the gas inlet, 2 is the gas inlet, and 3 is the gas governor. In the four gas burners, 5 indicates a temperature sensor. Here, a center-touch type temperature sensor for detecting the temperature at the bottom of the pot 6 will be used as an example. 7
is a temperature setting knob, and 8 shows a control circuit that compares and amplifies the value set here with the signal from the sensor 5 and outputs the signal to the gas governor 3.

Normally, the gas governor 3 operates to keep the gas pressure on the secondary side B at a predetermined constant value even if the gas pressure on the primary side A fluctuates, thereby stabilizing the combustion of the burner 4. However, in the present invention, the governor 3 is provided with a drive section 9 which also has the function of varying the set secondary pressure of the governor 3. When the drive unit 9 is kept constant, it operates as a normal governor and also operates to control fluctuations in primary pressure.

FIG. 2 shows a specific example of the governor 3 and the drive unit 9.
The lower half shown in FIG. 2 shows the governor section 3, in which gas flows from the primary side A, passes through the gap between the valve 10 and the valve seat 11, and flows into the secondary side B. Here, the valve 10 is connected to a diaphragm 12, and a spring 13 on the back surface of the diaphragm 12 constantly urges the valve 10 downward. Now, when gas flows into the chamber C from the primary side A, the gas pressure pushes the diaphragm 12 upwards and it comes to rest at a point balanced with the force of the spring 13. At this time, gas flows from the gap between the valve 10 and the valve seat 11 and flows out from B. Here, when the pressure on the primary side A increases, the pressure in the chamber C increases, and the diaphragm is balanced at a point further above.
Therefore, the valve 10 also rises, and the gap with the valve seat 11 becomes smaller, thereby restricting the amount of gas. In other words, the valve is throttled by the amount that the primary gas pressure has increased, keeping the secondary gas pressure constant. As described above, the governor operates so that the secondary pressure is always constant. The chamber D is at atmospheric pressure due to the small hole 14.

The upper half of FIG. 2 shows the drive section 9. In this example, rack gear 1 mounted on spring 13
5 and a pinion gear 17 in contact therewith which is rotationally driven by a DC motor 16, and the rack gear 15 is provided with a cam 20 for turning switches 18 and 19 on and off. As shown in the figure, when the rack gear 15 is at the top, the spring 13 is weak and the secondary gas pressure is low, and when the rack gear is at the bottom, the spring 13 is strong and the secondary gas pressure is set high. That is, the motor 16 moves the rack gear 15 to control the gas pressure in high-low.

FIG. 3 shows a driving principle circuit for the motor shown in FIG. 2. A series circuit of contacts 18a, 19a of interlocking switches 21, 22 and switches 18, 19 driven by cam 20 is connected to a series circuit of power supplies 23, 24,
The middle point M of the power supplies 23 and 24 and the switch contact 18a,
The motor 16 is connected between the midpoint N of 19a. Now, when the rack gear 15 is stopped above, the state is shown in FIG. 3, and the motor 16 is not energized, so the amount of combustion remains low. Next, when the switches 21 and 22 are operated in the opposite direction as shown in the figure, current flows from the power supply 24 through the M and N normally closed contacts 19a switch 22, and the motor is turned into the rack gear 1.
Rotate in the direction of pushing down 5. rack gear 15
When the cam 20 is slightly lowered, the cam 20 is removed from the switch 18, and the contact 18a is closed. However, since the switch 21 is open at this time, no current flows from the power supply 23.

When the rack gear 15 further descends, the cam 20 pushes the switch 19 and opens the contact 19a, so that the motor 16 stops rotating. At this time, the gas pressure is set to high.

Next, when switches 21 and 22 are switched to return to the state shown in FIG.
It flows through contacts 18a and N to motor 16 and to M. Therefore, the motor rotates in the opposite direction, and the rack gear 15 is pulled upward and stopped at the above point. As described above, the gas pressure set value can be switched between high and low by switching the switches 21 and 22, so high and low control is possible by automatically controlling the switches 21 and 22.

FIG. 4 shows a specific example of a control circuit 8 to which this is applied.

A bridge is constituted by a series circuit of resistors 25, 26, and 27, a temperature setting variable resistor 7, and a temperature sensor 5 (here, a negative temperature-sensitive resistance element). The reference potential F of the bridge and the detection potential E are detected by the comparator 28.
(here, an example using a commercially available two-input open collector type comparator is shown) is connected to the positive and negative inputs of the comparator. The comparator 28 has a reference potential F
If the detected potential E is larger than E, the output will be high (equivalent to the switch 28a shown by the broken line being open), and if the potential F>E, the output will be low (the switch 28a will be closed). Further, transistors 21 and 22 are connected corresponding to the switches 21 and 22 in FIG.
Now, since the burner is performing low combustion, the temperature of the sensor 5 is decreasing. Therefore, the potential E increases and when it exceeds F, the output potential becomes high, and the potential becomes equal to the power supply potential P. Therefore, the transistor 21 is cut off. At the same time, the diode 29 becomes reverse biased, so the Q potential changes to the resistor 3.
The transistor 22 becomes conductive because it becomes a divided potential of the combined resistance of 0 and 31 and the resistance 32. Therefore, the state is the same as when the switch 21 is off and 22 is on in FIG. 3, and the motor 16 rotates to lower the rack gear 15, resulting in high combustion. Next, when the temperature of the sensor 5 rises, the potential E decreases, and when the potential E<F, the potential O becomes low. Therefore, transistor 2
At the base of the transistor 1, a divided potential is generated between the resistors 33 and 34, and the transistor 21 becomes conductive, and the Q potential is grounded through the diode 29, so the transistor 22 is cut off, and the switch 21 in FIG. 22 Motor 1 switched to off state
Rotate 6 in the opposite direction. In other words, the combustion amount of the burner can be controlled high or low depending on the temperature detected by the sensor 5.

In FIGS. 3 and 4, two power supplies 23 and 24 are used and the motor is connected to the two power supplies. The configuration may be such that the motor 16 is connected between the points. Further, in FIG. 2, the rotational motion of the motor 16 is converted into linear motion by the rack gear 15 and pinion gear 17, but the same effect can be obtained by using a structure other than this, such as a cam.

Effects of the Invention As explained above, the combustion apparatus with a temperature control device of the present invention has the following effects.

(1) Since the configuration automatically switches the gas pressure setting of the gas governor using an electronic circuit according to the temperature of the burner load, the two functions of temperature control function and gas governor function can be obtained with one component, making the device compact. Design becomes possible and reliability improves.

(2) Since the combustion amount of the burner is controlled by varying the gas pressure setting value, the variable range of the drive unit is wider than that of the combustion amount control means that directly controls the gas passage resistance. Therefore, it is possible to stably control the combustion amount even at a minute flow rate for equipment with a low combustion amount, such as a gas stove, or gas with a high calorific value, such as propane gas.

(3) Since the drive unit is driven by a motor, current flows to the motor only when switching the combustion amount, and almost no power is consumed at other times. Therefore, it saves energy, can be powered by dry cell batteries, and can be applied to devices without power cords, such as gas stoves.

(4) Since the motor drive is configured to automatically stop the power supply when the drive amount reaches a predetermined amount by switches 18 and 19, the motor drive circuit is
It is possible to accurately switch the combustion amount by simply driving the engine forward or reverse based on the temperature sensor signal.

(5) Since the combustion amount is switched by a motor, it takes time to switch. Therefore, it is safe because there is no misfire, backfire, or incomplete combustion due to sudden changes in combustion amount.

[Brief explanation of the drawing]

Fig. 1 is a control system diagram of a combustion device with a temperature control device showing an embodiment of the present invention, Fig. 2 is a sectional view of the governor drive section of the device, and Fig. 3 shows the principle of the motor drive section of the device. The circuit diagram to be described, FIG. 4, is a circuit diagram of a temperature control circuit using the drive section of the same device. 3... Gas governor, 4... Gas burner, 5...
Temperature sensor, 6... Pot (object to be heated), 7... Temperature setter, 8... Control circuit, 9... Drive section (means for varying gas pressure adjustment set value), 10... Valve, 12...
...Diaphragm, 13...Pressure adjustment spring, 15
... Rack gear (means for switching between two strong and weak positions), 1
6...Motor, 17...Pinion gear (means for switching between two strong and weak positions), 18...Detection switch (second
detection switch), 19... detection switch (first detection switch), 19... detection switch (first
detection switch), 21...transistor (second detection switch), 21...transistor (second
(switching element), 22...transistor (first switching element).

Claims (1)

[Claims] 1. A gas burner that heats an object to be heated, a gas governor that regulates the gas inflow pressure to the gas burner, a temperature sensor that detects the temperature of the object to be heated, a temperature setting device that sets the temperature, and a temperature setting value and the temperature. It consists of a control circuit that compares and amplifies sensor signals, and a means for varying the gas pressure regulation set value of the gas governor based on the output of the control circuit, and the gas governor operates as a valve by balancing a diaphragm that receives gas pressure with a pressure regulation spring. The gap is adjusted, and the means for varying the gas pressure adjustment set value includes means for varying the pressure of the pressure adjustment spring into two strong and weak positions by forward and reverse rotation of a motor, and a pressure point of the spring for each of the strong and weak positions. The control circuit has a pair of switching elements that drive the motor in forward and reverse directions according to the temperature setting value and the signal from the temperature sensor, and the control circuit has a pair of switching elements that drive the motor in forward and reverse directions according to the temperature setting value and the signal from the temperature sensor. A first detection switch is provided in series with the first switching element for pressing the spring toward the strong side to detect when the pressing point on the strong side has been reached, and the motor is connected in the direction for pressing the pressure regulating spring toward the weak side. A combustion device with a temperature control device, which is provided with a second detection switch that detects when a weak pressure point has been reached in series with a second switching element that drives the switch.