WO2003001953A1

WO2003001953A1 - A directly heated electric pressure cooker

Info

Publication number: WO2003001953A1
Application number: PCT/CN2002/000009
Authority: WO
Inventors: Wei Wen Jian; Jing-Ran Fu; Jin-Quan Liu
Original assignee: Wei Wen Jian; Jing-Ran Fu; Jin-Quan Liu
Priority date: 2001-06-29
Filing date: 2002-01-09
Publication date: 2003-01-09
Also published as: CN2479871Y

Abstract

A directly heated electric pressure cooker according to the invention comprises a heating element welded with the inner case of the pressure cooker and a thermal control device with a probe. On one end of the thermal control device, there is a probe capable of being inserted in the guide hole on the bottom of the inner case of the pressure cooker, and in the probe there is a temperature switching circuit, capable of controlling the heating element on or off, with a temperature sensor. The electric pressure cooker has advantages of small bulk, little cost, fast heat transfer, high heat efficiency and long service time, and can cook food in multiple ways, such as braising, boiling, decocting and frying. In addition, it is convenient to employ, tend and repair the cooker.

Description

TECHNICAL FIELD

The invention relates to an electric pressure cooker, in particular to a direct heating type electric pressure cooker.

Background technique

Existing electric pressure cookers are provided with a shell, a pressure cooker bladder, an electric heating plate with electric heating elements, and a temperature control switch circuit. The pressure cooker is installed in the casing and placed on the electric heating plate; the temperature control switch is installed in the sandwich of the casing. The disadvantages of this electric pressure cooker are: the structure is complicated, the volume is large, and the cost is high, and because the electric heating plate is separated from the pot, the contact surface between the electric plate and the pot is high. , It will reduce the heat transfer efficiency. In addition, the high temperature in the housing will affect the service life of the temperature-controlled switch circuit.

Summary of the Invention

The technical problem to be solved by the present invention is to overcome the shortcomings of the electric pressure cooker, and to provide a direct-heating electric pressure cooker with simple structure, small size, low cost, high heat conduction efficiency and long service life.

The technical solution of the present invention to solve the above technical problem is to provide a direct-heating electric pressure cooker, which includes a pressure cooker lid with a pressure relief valve and a safety valve, a pressure cooker pot, an electric heating element, and a probe-type temperature controller. The needle type thermostat is equipped with a temperature control switch circuit with a temperature sensing element that can control the on-off of the electric heating element and is connected to an external power cord. One end of the probe type thermostat is provided with a bottom guide for the pressure vessel pot Hole probe, the end is also provided with the probe The power socket is electrically connected to the terminal in parallel with the needle; the electric heating element is welded to the pressure cooker pot; a temperature sensing sheet with a guide hole is provided between the parallel terminals; the temperature transmission of the temperature control switch circuit The sensing element is installed in the probe; the bottom of the pressure cooker pot is also provided with feet.

In the direct-heating electric pressure cooker according to the present invention, the electric heating element is a shaped electric heating tube, and the flat outer wall thereof is welded to the bottom of the pressure cooker pot.

In the direct-heating electric pressure cooker of the present invention, the temperature control switch circuit in the probe-type temperature controller is a single-chip numerical control circuit, and a control button and a liquid crystal of the single-chip numerical control circuit are provided on the shell of the probe-type temperature controller. monitor.

In the direct-heating electric pressure cooker of the present invention, the bottom of the pressure cooker bladder is provided with a support column higher than the electric heating element, and the legs are connected to the support column by screws.

The invention is provided with a probe type temperature controller, which can effectively reduce the influence of the high temperature generated by the electric pressure cooker on the temperature control switch circuit, thereby extending the life of the temperature control switch circuit in the probe type temperature controller; Welding with the bottom of the pressure cooker pot not only simplifies the structure and reduces the cost, but also fast heat transfer, high thermal efficiency, and long service life. Since the probe type thermostat is plug-in type, the power can be removed after removing it. The pressure cooker is put into water for cleaning as a whole, and when the probe temperature controller fails, it is also easy to repair it separately, so it is very convenient to use, clean and repair. The electric pressure cooker can cook food in various ways such as steaming, boiling, frying and frying.

Brief description of the drawings

FIG. 1 is a schematic diagram of an external appearance of a direct-heating electric pressure cooker according to an embodiment of the present invention; FIG. 2 is a schematic cross-sectional structure view taken along a line A in FIG. 1;

FIG. 3 is a schematic diagram of the B-direction structure of FIG. 1 with the feet and the handle removed; 4 is a schematic structural diagram of the probe-type temperature controller with the probe of FIG. 3 removed;

5 is a top view of the probe-type temperature controller in FIG. 1;

6 is a schematic cross-sectional structure view of FIG. 5;

7 is a circuit diagram of a temperature-controlled switch according to the embodiment of the present invention;

FIG. 8 is a circuit diagram of another temperature-controlled switch according to the embodiment of the present invention.

In the picture, a pressure cooker lid, 2—pressure cooker pot, 3—probe thermostat, 4 feet, 5—pot handle, 6—support column, 7—electric heating element, 8—check valve, 9— Pressure relief valve, 10—thermometer, 11—guide hole, 12—power socket, 13—probe, 14—parallel lead-out, 15—external power cord, 16—control button, 17—liquid crystal display.

Embodiments of the invention

As shown in FIG. 1, the direct pad-type electric pressure cooker of the present invention has a pressure cooker lid 1, a pressure cooker pot 2, a probe-type temperature controller 3 provided outside the bottom of the pressure cooker pot 2, and a bottom of the pressure cooker pot 2 Of feet 4.

As shown in FIG. 2, the direct-heating electric pressure cooker of the present invention is provided with a safety valve with a check valve 8 and a pressure relief valve 9 on the lid 1 of the pressure cooker; and a pair of pots on the outer wall of the pressure cooker pot 2 The 5, pot can be riveted to the outer wall of the pressure cooker pot with fasteners such as rivets; an electric heating element 7 and a support post 6 higher than the electric heating element 7 are provided at the bottom of the pressure cooker pot;

As shown in FIG. 3 and FIG. 4; the direct-heating electric pressure cooker of the present invention, the electric heating element 7 of which is an Ω-shaped electric heating tube, and its flat outer wall is connected to the bottom of the pressure cooker pot 2 with a welding connection, which is led out in two parallel to the electric heating tube A temperature sensing sheet 10 with an introduction hole is provided between the ends 14, and the introduction hole is coaxial with the guide hole 11 provided on the bottom side of the pressure vessel pot 2 and has the same size. As shown in FIG. 6 and FIG. 3, in the direct-heating electric pressure cooker of the present invention, the probe-type temperature controller 3 is provided with a temperature control switch-off circuit with a temperature sensing element capable of controlling the on-off of the electric heating element 7. , And is electrically connected to the external power cord 15. One end of the probe type thermostat 3 is provided with a probe 13 that can be inserted into the guide hole 11 on the bottom side of the pressure cooker pot. The end is also provided with a probe 13 that is parallel to the probe 13 and can be connected with The power socket 12 is electrically connected to the two end terminals 14 in parallel.

As shown in FIG. 5, the direct-heating type electric pressure cooker according to the present invention is provided with a control button 16 and a liquid crystal display 17 on the housing of the probe-type temperature controller 3.

A type of temperature control switch circuit in the probe type temperature controller is a single-chip microcomputer numerical control circuit, and its circuit diagram is shown in FIG. 7. The circuit is composed of a single-chip microcomputer circuit with fuzzy logic control function. The single-chip microcomputer IC1 uses GMS81504 integrated circuit. It has 30 pins and a memory capacity of 4KB. In normal operation, a DC power supply VDD (5 ~ 5.5V) is required at pin 30. , Pin 20 plus DC power supply VSS (5V). Store the voltage in this microcontroller to cancel each working state control program and the voice chip IC3 address signal. The user can select different work programs by pressing different button keys, and different voices occur at the same time to start the pressure cooker to work. During the working process, the temperature signal is from IC17 and 9 pins, and the key control signal is input through pins 8, 10, 11, 13, 15, and 16; the driving heating control signal is output from pins 5, 30, and 23; Pins 1-4, 21-22, and 24-29 are used to complete. Voice or sound address is drawn on pins 14, 17, 20, and voice or sound can be activated and the signal is serially connected from pin to IC2 and IC2. To the pronunciation chip (microcontroller). Bow! Feet 18 and 19 are externally connected to a crystal oscillation circuit consisting of R9, C7, and C8, which provides a 4Mc crystal frequency for the microcontroller operation.

The model of the voice chip IC3 in the voice generating circuit is AP1840W voice amplifier The circuit includes transistors Q4 resistors R4, R22, etc .; IC3 voice microcontroller has statements to be issued by the pressure cooker to work, different sections store different sounds, and different sounds can be issued by pressing different keys.

The function status display circuit is mainly composed of R20, R21, R22, R23, R24, R25, C7, C8, R9 crystal oscillator, XTAL and special design (LCD) liquid crystal display, single chip microcomputer ICl and 6 keys, which are used to display the function status and Display the time status in the function status, which can be used to select different computer working procedures and statuses.

The heater control circuit has a heater (heating plate). The power of TR1 and TR2 is 1000W-1400W. It is mainly used for cooking food in the pot to pressurize or maintain pressure. The fuzzy control and IC1 5 feet, 30 feet, 23 Use the relay to control the length of heating time and the temperature to control the pressure.

The protection circuit includes TR, E3, C9, CIO, D4, IC15 pin, 30 pin, etc. When the power supply is normally supplied, the + 5V DC voltage from the rectifier circuit is added to the IC130 pin through the diode BD4 branch and E3, E9 VDD. At this time, IC1 pin 5 outputs a high level, and the voltage of C10 is 5.5V. When the power is turned off, the IC1 pin becomes a low level, which interrupts the processing of IC1. The current and voltage of C10 are used for D9 isolation and E3 discharge. The chip in the circuit has (IC) built-in COMS circuit devices, which consumes little power and can be maintained for 30 minutes. When the power is restored, the circuit can be restored to its working state before power down without re-energizing.

The reset circuit is composed of H7, R8, TR3, R6, R5, C6, Z3. When overtemperature is detected and abnormal temperature rise is found within a short time, the heater will be disconnected or a symbol will prompt. When the temperature is reset, TR3 A low level appears to control the 17-pin microcontroller, so that the microcontroller can effectively resume the current working state. The pot-poor thousand-burn protection circuit consists of K8, R3, R32, and IC1 14 pins. When K1 is closed, IC1 becomes high, and when K1 is disconnected, IC1 becomes low. When the pot is not put, the microcontroller will be automatically cut off. Working power, the entire system fails to heat up and does not boost.

Another type of temperature control switch circuit in the probe type temperature controller is also a single chip microcomputer numerical control circuit, and its circuit diagram is shown in FIG. 8. The single-chip microcomputer (IC1) of this circuit uses MB89983 chip, which is a 16-bit single-chip microcomputer with 64 pins and 8KB of memory. It is connected to a 3 ~ 3.6V DC power supply during normal operation.

The circuit structure of the input terminal of the single-chip microcomputer is:

The temperature sensor of the temperature detection circuit uses a thermistor RT, which converts the temperature signal into an electrical signal and sends it to pins 7 and 10 of the microcontroller. The temperature sensor can provide the microcontroller with working temperature limit, abnormal temperature rise, and open-circuit short-circuit and over-temperature protection. Protection signals such as working pressure, real-time detection and control of the working state of the electric pressure cooker through the built-in program of the single chip microcomputer;

The function selection keyboard circuit is a keyboard scanning circuit composed of keys S1 ~ S7 and resistors R8 ~ R14. It is connected to pins 15 and 25 ~ 30 of the microcontroller. The program in the microcontroller uses different function keys to input different signals to select the control program;

The reset circuit is composed of buttons S8, C16, E7, R24, D3, IC2 and other components. It is connected to pin 19 of the single-chip microcomputer. When a crash occurs or the current working state is eliminated and the execution situation, press S8 to reset;

This example is also provided with an open-circuit short-circuit protection circuit. Its structure is a fuse FUSE connected in series at the input end of the power supply. The function is to power off the control board under short-circuit and open-circuit conditions. Resistor-capacitor step-down routing VI, C8 ~ C10, R32, R31, D7, D8, Cll, E3, R29, R30, Z3, Z4, R28, C13, E5, Z2 are composed of 5VDC power supply and relay power supply. source.

The 5VDC power circuit consists of Z2, C14, E6, and C15, and provides a source of 3.6VDC (single chip computer operation) power.

The circuit structure of the output of the single-chip microcomputer is:

The liquid crystal display circuit is composed of a liquid crystal display (specific design), and there is no editing program control in the single chip microcomputer to realize functions and various status displays;

The heating control switch circuit is a differential amplifier circuit composed of TR1 and TR2. Its input terminal is connected to the 46 and 16 pins of the microcontroller. The collector of the output circuit TR2 is connected in series with a relay coil RY1. When TR2 is turned on, a current flows through RY1. Control the on / off of the electric heating tube through its contact;

The power-off memory protection circuit between the heating control switch circuit and the output of the single-chip microcomputer is at the input terminal E10 of the heating control switch circuit. When the power is cut off, the capacitor can maintain the state before the power off. Previous working status

The audible alarm circuit is composed of Q2, Bl, and R35. The 16-pin microcontroller can be connected to realize the audible alarm function.

Industrial applicability

The direct-heating electric pressure cooker of the present invention can cook food in a variety of ways such as steaming, cooking, frying, and frying, and since the probe-type temperature controller is plug-in type, the whole electric pressure cooker can be put into water after being pulled out. It is easy to clean when it fails, so it is very convenient to use, maintain, and guarantee the electric pressure cooker.

Claims

Claim

1. A direct-heating electric pressure cooker, comprising a pressure cooker lid (1) with a pressure relief valve and a safety valve, a pressure cooker pot (2), and an electric heating element (7), characterized in that it further comprises a probe-type temperature control The temperature controller (3) is provided with a temperature control switch circuit with a temperature sensing element capable of controlling the on-off of the electric heating element (7), and is connected to an external power line (15) point; a probe-type temperature controller (3) ) One end is provided with a probe (13) that can be inserted into the guide hole (11) of the bottom of the pressure cooker pot, and the end is also provided with two parallel leads that are parallel to the probe and can be drawn out with the two heating elements (7) as the probe is inserted The terminal (14) is a power socket (12) for electrical connection; the electric heating element (7) is connected to the pressure cooker pot (2) by welding, and a band is provided between the two parallel-lead terminals (14). Guide hole (11) Coaxial and equal-sized lead-in temperature-sensing sheet (10); The temperature sensing element of the temperature control switch circuit is installed in the probe (13); the bottom of the pressure cooker pot is also provided with a foot (4).

2. The direct-heating electric pressure cooker according to claim 1, characterized in that: the electric heating element (7) is a shaped electric heating pipe, and is connected with the bottom of the pressure cooker pot (2) by a flat outer wall.

3. The direct-heating electric pressure cooker according to claim 1 or 2, characterized in that: the temperature-control switch circuit in the probe-type temperature controller (3) is a single-chip numerical control circuit, and in the probe-type temperature control The shell of the device (3) is provided with a control button (16) and a liquid crystal display (17) of a single-chip numerical control circuit.

4. The direct-heating electric pressure cooker according to claim 1 or 1, characterized in that the bottom of the pressure cooker pot (2) is provided with a support column (6) higher than the electric heating element (7), The feet (4) are connected to the support posts (6) by screws.

5. The direct-heating type electric cooker according to claim 3, characterized in that: the bottom of the pressure cooker pot (2) is provided with a support column (6) higher than the electric heating element (7), and the legs (4) pass through The screw is connected to the support post (6).