Deep fryer control system

Abstract

The present invention relates to a control system for a deep-fried oil fryer, the control system comprises a power module, a control module, a heating tube, and an oil injection pump, the power module, the control module, the heating tube, and the oil injection pump form a control loop, the control module comprises a heating control circuit and an oil injection control circuit; the control system comprises an interlocking module for controlling the interlocking of the heating control circuit and the oil injection control circuit, the interlocking module comprises a five-pin relay, two coil pins of the five-pin relay are connected to the heating control circuit, the heating control circuit is powered to realize the switching conduction of the normally closed contact and the normally open contact, the middle contact of the five-pin relay is connected to the power module, the normally open contact is connected to the heating tube, and the normally closed contact is connected to the oil injection control circuit and the oil injection pump. Through the above, the interlocking of oil injection and heating is effectively realized, and the oil injection operation under high temperature or heating state is effectively prevented, and the use is safer and more reliable.

Description

Technical Field

[0001] The invention relates to the field of household appliance control and is a control system for a deep fryer. Background Art

[0002] An air fryer is a machine that can use air for "frying". It mainly uses air to replace the hot oil in the frying pan to cook the food. At the same time, the hot air blows away the moisture on the surface of the food, making the food almost fried. In order to simplify the operation, some existing air fryers are usually equipped with an oil spraying device, such as the application number 201920479809.5 disclosed in the Chinese patent literature, the authorization announcement date is May 26, 2020, and the utility model name is "A food processor capable of spraying oil". It discloses an automatic oil spraying device, which not only simplifies the operation compared to manual oiling, but also makes the food more evenly oiled, which can reduce the waste of cooking oil. There is also an application number 202021111934.X published in the Chinese patent literature, with an authorization announcement date of December 17, 2021, and the utility model name is "Air Fryer". It also discloses an automatic oil injection scheme that can effectively control the amount of oil. It obtains the corresponding cooking temperature, time, oil injection temperature and other parameters according to the information on the label, thereby controlling the start of the driving member to spray a certain amount of oil mist into the accommodating cavity to achieve cooking and frying operations. However, in the existing oil injection device, the oil injection control unit and the electric heating control unit are usually independently controlled, that is, oil injection and heating are often carried out at the same time. In this case, there are certain safety hazards. When the temperature control in the air fryer fails, causing the temperature in the cavity to rise sharply, and the oil injection pump sprays more oil mist at the same time, it is very easy to cause an explosion, causing unnecessary losses. For this reason, it is necessary to improve the oil injection and heating control of the existing air fryer. Summary of the invention

[0003] In order to overcome the above shortcomings, the purpose of the present invention is to provide a control system for a deep fryer in the art, so as to solve the technical problem that the oil injection and heating of the existing deep fryers are not effectively interlocked, resulting in temperature control failure or safety accidents caused by oil injection at high temperature. The purpose is achieved through the following technical solutions.

[0004] A control system for a deep-fryer, the control system comprising a power module, a control module, a heating tube, and a fuel injection pump, wherein the power module, the control module, the heating tube, and the fuel injection pump form a control loop, and the control module comprises a heating control circuit and a fuel injection control circuit; the characteristic is that the control system comprises an interlocking module for controlling the interlocking of the heating control circuit and the fuel injection control circuit, the interlocking module comprises a five-pin relay, the heating control circuit comprises a resistor R9, a resistor R11, a transistor Q2, a transistor Q3, and a diode D6, one end of the resistor R9 serves as a HOT connection end, the other end of R9 is shunt-connected to the base of the transistor Q2, the base of the transistor Q3, and one end of the resistor R11, the collector of the transistor Q2 is shunt-connected to the positive electrode of the diode D6 and one of the coil pins of the five-pin relay, the negative electrode of the diode D6 and another coil pin of the five-pin relay are connected to a positive +5V power supply, and the The emitter of the transistor Q2 is connected to the collector of the transistor Q3, and the emitter of the transistor Q3 and the other end of the resistor R11 are both grounded; the fuel injection control circuit includes a resistor R5, a resistor R10, a resistor R15, a transistor Q6, and a bidirectional thyristor VT2, one end of the resistor R5 is used as a motor signal connection end, the other end of R5 is branched to connect the base of the transistor Q6 and one end of the resistor R10, the collector of the transistor Q6 is connected to one end of the resistor R15, the other end of the resistor R15 is connected to the control electrode of the bidirectional thyristor VT2, the first anode of the bidirectional thyristor VT2 is connected to the normally closed contact of the five-pin relay, the second anode of the bidirectional thyristor VT2 is connected to the fuel injection pump, the emitter of the transistor Q6 and the other end of the resistor R10 are both grounded; the middle contact of the five-pin relay is connected to the power module, and the normally open contact is connected to the heating tube. Through the above circuit, the heating control circuit is used to control the switching of the normally closed contacts and the normally open contacts of the five-pin relay to realize the interlocking of fuel injection and heating, which effectively prevents the fuel injection operation under high temperature or heating state, and is safer and more reliable to use.

[0005] The control system includes a single-chip microcomputer and a voltage stabilizing and regulating circuit. The HOT connection end of the heating control circuit and the motor signal connection end of the injection control circuit are both connected to the corresponding pins of the single-chip microcomputer. The 5V square wave signal of the single-chip microcomputer is provided by the voltage stabilizing and regulating circuit. The voltage stabilizing and regulating circuit includes a resistor R7, a resistor R8, a resistor R12, a diode D5, a transistor Q1, a resistor R3, and a capacitor C3. One end of the resistor R7 is an AC connection end, and the other end is connected in series with a resistor R8. The resistor R8 is connected in a branch path to the resistor R12, the cathode of the diode D5, and the base of the transistor Q1. The other end of the resistor R12, the anode of the diode D5, and the emitter of the transistor Q1 are connected to the ground and one end of the capacitor C3. The other end of the capacitor C3 is connected to the collector end of the transistor Q1 and is simultaneously connected to the square wave signal pin of the single-chip microcomputer and one end of the resistor R3. The other end of the resistor R3 is a +5V connection end. Through the voltage stabilizing and regulating circuit, the input AC alternating current is converted into a 5V square wave signal for the single-chip microcomputer.

[0006] The control system also includes a photoelectric liquid level detection circuit for detecting the amount of oil in the oil box connected to the fuel injection pump. The photoelectric liquid level detection circuit includes a photoelectric liquid level sensor, a capacitor C4, and a capacitor C5. The VCC pin of the photoelectric liquid level sensor is connected to the +5V input and one end of the capacitor C4, the VOUT pin of the photoelectric liquid level sensor is connected to the voltage signal input pin corresponding to the single-chip computer, the GND pin of the photoelectric liquid level sensor is connected to the ground, and the other ends of the capacitors C4 and C5 are both connected to the ground. By detecting different output voltage signals, three situations can be realized: the oil box has oil, the oil box has no oil, and the oil box is taken away.

[0007] The control system includes a fan module for heat dissipation, the fan module includes a fan circuit and a fan motor, the fan circuit includes a resistor R2, a resistor R4, a resistor R6, a transistor Q4, and a bidirectional thyristor VT1, one end of the resistor R2 is a fan signal connection end, the other end of the resistor R2 is connected to one end of the resistor R4 and the base of the transistor Q4, the emitter of the transistor Q4 and the other end of the resistor R4 are both connected to the ground, the collector of the transistor Q4 is connected in series with the resistor R6 and connected to the control end of the bidirectional thyristor TV1, the first anode of the bidirectional thyristor is connected to the fan motor, and the second anode is connected to the power module. The fan motor is controlled by the fan module.

[0008] The control system includes a micro switch protection circuit, that is, a micro switch is provided in the neutral line circuit of the power supply circuit formed by the fuel injection control circuit, the heating control circuit, the fan circuit and the power module. When the micro switch is disconnected, the neutral line circuit is disconnected. By setting the micro switch, when the micro switch is turned off, the heating pipe, the fan motor and the fuel injection pump cannot work in the case of software failure.

[0009] The invention realizes the interlocking of oil injection and heating, that is, oil injection and heating do not work simultaneously, effectively solves the problem of temperature control failure or safety accidents that may occur when oil is injected at high temperature, and is safer and more reliable to use. It is suitable for use as a control circuit of an oil-spraying fryer, or an improvement of similar control methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is the control principle diagram of the present invention.

[0011] Figure 2 It is the overall circuit diagram of the present invention.

[0012] Figure 3 yes Figure 2 The interlock module circuit diagram in.

[0013] Figure 4 yes Figure 2 The voltage regulation circuit diagram in .

[0014] Figure 5 yes Figure 2 Photoelectric liquid level detection circuit diagram.

[0015] Figure 6 It is the wiring diagram of the heating pipe, fuel injection pump, fan motor and micro switch of the present invention.

[0016] The serial numbers and names in the figure are: 1. Control system, 2. Heating tube, 3. Fuel injection pump, 4. Fan motor, 5. Temperature sensor, 6. Photoelectric liquid level sensor, 7. UI human-computer interaction module, 8. Micro switch. DETAILED DESCRIPTION

[0017] Now, this work will be further described with reference to the accompanying drawings.

[0018] like Figure 1-5As shown, the control system 1 of the oil-spraying fryer includes a power module, a control module, a heating tube 2, and an oil injection pump 3. The power module, the control module, the heating tube, and the oil injection pump form a control loop. The control module includes a heating control circuit and an oil injection control circuit. The control system includes an interlocking module for controlling the interlocking of the heating control circuit and the oil injection control circuit. The interlocking module includes a five-pin relay. The heating control circuit includes a resistor R9, a resistor R11, a transistor Q2, a transistor Q3, and a diode D6. One end of the resistor R9 serves as a HOT connection end, and the other end of R9 is connected to the base of the transistor Q2, the base of the transistor Q3, and one end of the resistor R11. The collector of the transistor Q2 is connected to the positive electrode of the diode D6 and one of the coil pins of the five-pin relay. The negative electrode of the diode D6 and the other coil pin of the five-pin relay are connected to the positive +5V power supply. The emitter of the transistor Q2 is connected to the collector of the transistor Q3, and the emitter of the transistor Q3 and the other end of the resistor R11 are both connected to the ground. The circuit includes resistor R5, resistor R10, resistor R15, transistor Q6, and bidirectional thyristor VT2. One end of resistor R5 is used as the motor signal connection end, and the other end of R5 is connected to the base of transistor Q6 and one end of resistor R10 in a branch path. The collector of transistor Q6 is connected to one end of resistor R15, and the other end of resistor R15 is connected to the control electrode of bidirectional thyristor VT2. The first anode of bidirectional thyristor VT2 is connected to the normally closed contact of the five-pin relay, and the second anode of the bidirectional thyristor VT2 is connected to the injection pump (represented as MOTOR1 in the circuit). The emitter of transistor Q6 and the other end of resistor R10 are both grounded; the middle contact of the five-pin relay is connected to the power module, and the normally open contact is connected to the heating tube (represented as HEAT-UP1 in the circuit).

[0019] The working principle of the above interlocking module is as follows: when the HOT connection terminal is at a high level, the transistors Q2 and Q3 are turned on, and the 2nd and 3rd pins of the five-pin relay are turned on, so that the heating tube works. On the contrary, when the HOT connection terminal is at a low level, the 2nd and 4th pins of the five-pin relay are turned on, and the heating tube stops heating. When the heating tube stops heating, when the motor signal connection terminal (MOTOR2 in the figure) in the fuel injection control circuit is at a high level, the transistor Q6 is turned on, and current is provided to the 3rd pin of the bidirectional thyristor VT2, so that the bidirectional thyristor VT2 is turned on, and the fuel injection pump (MOTOR1 in the figure) starts working, and the fuel injection operation is realized; when MOTOR1 is at a low level, the transistor Q6 is turned off, and there is no current at the 3rd pin of the bidirectional thyristor VT2, so that the bidirectional thyristor VT2 is turned off, and the fuel injection pump stops working. In this way, the heating and fuel injection interlocking can be realized, which effectively prevents the temperature in the fryer cavity from rising sharply due to the failure of temperature control detection, and the oil pump sprays more oil mist at the same time to cause an explosion.

[0020] The control system also includes a single-chip microcomputer and a voltage stabilizing and regulating circuit. The HOT connection end of the heating control circuit and the motor signal connection end of the injection control circuit are both connected to the corresponding pins of the single-chip microcomputer. The 5V square wave signal of the single-chip microcomputer is provided by the voltage stabilizing and regulating circuit. The voltage stabilizing and regulating circuit includes resistor R7, resistor R8, resistor R12, diode D5, transistor Q1, resistor R3, and capacitor C3. One end of the resistor R7 is an AC connection end, and the other end is connected in series with resistor R8. The resistor R8 is connected in a branch to the resistor R12, the cathode of the diode D5, and the base of the transistor Q1. The other end of the resistor R12, the anode of the diode D5, and the emitter of the transistor Q1 are connected to the ground and one end of the capacitor C3. The other end of the capacitor C3 is connected to one end of the collector of the transistor Q1 and is simultaneously connected to the square wave signal pin of the single-chip microcomputer and one end of the resistor R3. The other end of the resistor R3 is a +5V connection end.

[0021] The control system also includes a photoelectric liquid level detection circuit for detecting the amount of oil in the oil box connected to the injection pump. The photoelectric liquid level detection circuit includes a photoelectric liquid level sensor 6, a capacitor C4, and a capacitor C5. The VCC pin of the photoelectric liquid level sensor is connected to the +5V input and one end of the capacitor C4, the VOUT pin of the photoelectric liquid level sensor is connected to the voltage signal input pin corresponding to the microcontroller, the GND pin of the photoelectric liquid level sensor is connected to the ground, and the other ends of the capacitors C4 and C5 are both connected to the ground.

[0022] The control system also includes a fan module for heat dissipation, the fan module includes a fan circuit and a fan motor 4 (represented as FAN in the circuit), the fan circuit includes a resistor R2, a resistor R4, a resistor R6, a transistor Q4, and a bidirectional thyristor VT1, one end of the resistor R2 is a fan signal connection end, the other end of the resistor R2 is branched and connected to one end of the resistor R4 and the base of the transistor Q4, the emitter of the transistor Q4 and the other end of the resistor R4 are both grounded, the collector of the transistor Q4 is connected in series with the resistor R6 and is connected to the control end of the bidirectional thyristor TV1, the first anode of the bidirectional thyristor is connected to the fan motor, and the second anode is connected to the power module.

[0023] like Figure 6 As shown, the control system also includes a micro switch protection circuit, that is, a micro switch 8 is provided in the neutral line loop of the power supply loop formed by the fuel injection control circuit, the heating control circuit, the fan circuit and the power module. When the micro switch is disconnected, the neutral line loop is disconnected. At this time, when the software fails, the heating pipe, the fuel injection pump and the fan motor cannot work.

[0024] In addition, the circuit of the present invention also includes functional modules such as a UI human-computer interaction module 7, a temperature detection circuit (including a temperature sensor 5), etc., which respectively implement corresponding functions. Since the functional structure is well known, it will not be described in detail.

[0025] The above contents are intended to illustrate the technical means of the present invention, but not to limit the technical scope of the present invention. Those skilled in the art may make obvious improvements or substitutions to the present invention in combination with existing common knowledge, which also fall within the protection scope of the claims of the present invention.

Claims

1. A control system for a deep-fryer, the control system (1) comprising a power module, a control module, a heating tube (2), and a fuel injection pump (3), wherein the power module, the control module, the heating tube, and the fuel injection pump form a control loop, and the control module comprises a heating control circuit and a fuel injection control circuit; characterized in that The control system includes an interlocking module for controlling the interlocking of the heating control circuit and the injection control circuit. The interlocking module includes a five-pin relay. The heating control circuit includes a resistor R9, a resistor R11, a transistor Q2, a transistor Q3, and a diode D6. One end of the resistor R9 serves as a HOT connection end, and the other end of R9 is branched to the base of the transistor Q2, the base of the transistor Q3, and one end of the resistor R11. The collector of the transistor Q2 is branched to the positive electrode of the diode D6 and one of the coil pins of the five-pin relay, the negative electrode of the diode D6 and the other coil pin of the five-pin relay are connected to the positive +5V power supply, the emitter of the transistor Q2 is connected to the collector of the transistor Q3, and the emitter of the transistor Q3 and the other end of the resistor R11 are connected to the positive +5V power supply. One end is connected to the ground; the fuel injection control circuit includes a resistor R5, a resistor R10, a resistor R15, a transistor Q6, and a bidirectional thyristor VT2, one end of the resistor R5 is used as a motor signal connection end, the other end of R5 is connected to the base of the transistor Q6 and one end of the resistor R10, the collector of the transistor Q6 is connected to one end of the resistor R15, the other end of the resistor R15 is connected to the control electrode of the bidirectional thyristor VT2, the first anode of the bidirectional thyristor VT2 is connected to the normally closed contact of the five-pin relay, the second anode of the bidirectional thyristor VT2 is connected to the fuel injection pump, the emitter of the transistor Q6 and the other end of the resistor R10 are both connected to the ground; the middle contact of the five-pin relay is connected to the power module, and the normally open contact is connected to the heating tube.

2. The control system of the deep fryer according to claim 1, characterized in that The control system (1) comprises a single-chip microcomputer and a voltage regulating circuit. The HOT connection end of the heating control circuit and the motor signal connection end of the injection control circuit are both connected to corresponding pins of the single-chip microcomputer. The 5V square wave signal of the single-chip microcomputer is provided by the voltage regulating circuit. The voltage regulating circuit comprises a resistor R7, a resistor R8, a resistor R12, a diode D5, a transistor Q1, a resistor R3, and a capacitor C3. One end of the resistor R7 is an AC connection end, and the other end is connected in series with a resistor R8. The resistor R8 is connected in a branch path to the resistor R12, the cathode of the diode D5, and the base of the transistor Q1. The other end of the resistor R12, the anode of the diode D5, and the emitter of the transistor Q1 are connected to the ground and one end of the capacitor C3. The other end of the capacitor C3 is connected to one end of the collector of the transistor Q1 and is also connected to the square wave signal pin of the single-chip microcomputer and one end of the resistor R3. The other end of the resistor R3 is a +5V connection end.

3. The control system of the deep fryer according to claim 2, characterized in that The control system (1) further comprises a photoelectric liquid level detection circuit for detecting the amount of oil in the oil box connected to the fuel injection pump, the photoelectric liquid level detection circuit comprising a photoelectric liquid level sensor (6), a capacitor C4, and a capacitor C5, the VCC pin of the photoelectric liquid level sensor being connected to a +5V input and one end of the capacitor C4, the VOUT pin of the photoelectric liquid level sensor being connected to a voltage signal input pin corresponding to the single-chip computer, the GND pin of the photoelectric liquid level sensor being connected to ground, and the other ends of the capacitors C4 and C5 being connected to ground.

4. The control system of the deep fryer according to claim 2, characterized in that The control system (1) comprises a fan module for heat dissipation, the fan module comprises a fan circuit and a fan motor (4), the fan circuit comprises a resistor R2, a resistor R4, a resistor R6, a transistor Q4, and a bidirectional thyristor VT1, one end of the resistor R2 is a fan signal connection end, the other end of the resistor R2 is connected in a branch to one end of the resistor R4 and the base of the transistor Q4, the emitter of the transistor Q4 and the other end of the resistor R4 are both connected to the ground, the collector of the transistor Q4 is connected in series with the resistor R6 and is connected to the control end of the bidirectional thyristor TV1, the first anode of the bidirectional thyristor is connected to the fan motor, and the second anode is connected to the power module.

5. The control system of the deep fryer according to claim 4, characterized in that The control system (1) comprises a micro switch protection circuit, that is, a micro switch (8) is provided in the neutral line circuit of the power supply circuit formed by the fuel injection control circuit, the heating control circuit, the fan circuit and the power module, and when the micro switch is disconnected, the neutral line circuit is disconnected.

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