Pressure detection device with improved control precision of pressure cooking appliance

Patent metadata

Field	Value
Publication number	US-11399651-B2
Application number	US-201616338009-A
Country	US
Kind code	B2
Filing date	Dec 27, 2016
Priority date	Dec 13, 2016
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

Disclosed is a pressure detection device configured to detect pressure intensity in a sealed cavity of a cooking appliance, comprising: a pressure sensing assembly comprising a fixed part and a movable part, in which the movable part moves relative to the fixed part when a pressure change in the sealed cavity is sensed, so as to cause a sensing parameter of the pressure sensing assembly to change; and a detecting unit connecting with the pressure sensing assembly and can acquire the pressure intensity in the sealed cavity according to a current sensing parameter of the pressure sensing assembly. The pressure sensing assembly further comprises a flexible sealing sheet disposed at an open end of the body portion to seal the open end, and configured to be deformed towards the pressure chamber when an air pressure in the sealed cavity is greater than an air pressure in the pressure chamber.

First claim

What is claimed is:

1. A pressure detection device configured to detect pressure intensity in a sealed cavity of a cooking appliance, comprising:
a pressure sensing assembly comprising a fixed part and a movable part, in which the movable part is configured to move relative to the fixed part when a pressure change in the sealed cavity is sensed, so as to cause a sensing parameter of the pressure sensing assembly to change; and
a detection unit connected with the pressure sensing assembly, and configured to acquire the pressure intensity in the sealed cavity according to a current sensing parameter of the pressure sensing assembly;
wherein the pressure sensing assembly further comprises:
a body portion defining a pressure chamber therein, the pressure chamber having an opening facing the sealed cavity, and the body portion being provided with an air hole in communication with the pressure chamber; and
a flexible sealing sheet disposed at an open end of the body portion to seal the open end, and configured to be deformed towards the pressure chamber when an air pressure in the sealed cavity is greater than an air pressure in the pressure chamber, in which the movable part is fixed to the flexible sealing sheet and configured to move according to deformation of the flexible sealing sheet.

2. The pressure detection device according to claim 1 , wherein the sealed cavity is defined by a lid and a housing, and the detection unit comprises:
a first coupling coil disposed in the lid; and
a second coupling coil disposed in the housing and wirelessly coupled with the first coupling coil,
wherein one of the second coupling coil and the first coupling coil is connected with the pressure sensing assembly.

3. The pressure detection device according to claim 2 , wherein the pressure sensing assembly further comprises:
a body portion defining a pressure chamber therein, the pressure chamber having an opening facing the sealed cavity, and the body portion being provided with an air hole in communication with the pressure chamber, wherein two air holes are provided, and the two air holes are spaced apart in a top of the body portion, wherein the fixed part comprises a fixed electrode, the movable part comprises a movable electrode, and the movable electrode is configured to move relative to the fixed electrode when the pressure change is sensed, so as to cause a capacitance value of the pressure sensing assembly to change, wherein the detection unit comprises:
a third induction coil serving as the first coupling coil, and connected in parallel or in series with the pressure sensing assembly to constitute a second resonant circuit; and
a second detection assembly configured to detect a resonant frequency of the second resonant circuit and acquire the pressure intensity in the sealed cavity according to the resonant frequency of the second resonant circuit.

4. The pressure detection device according to claim 3 , wherein the second detection assembly comprises:
a fourth induction coil serving as the second coupling coil, and being in mutual induction with the third induction coil, in which the fourth induction coil generates a second induction signal according to a voltage signal or a current signal of the third induction coil;
a second detection chip connected with the fourth induction coil, and configured to detect a frequency of the second induction signal and acquire the resonant frequency of the second resonant circuit according to the frequency of the second induction signal; and
a second protection unit, at least a part of the second protection unit being disposed to a lower surface of the fixed electrode, and the second protection unit being configured to cut off power of a device for increasing an air pressure of the sealed cavity when at least a part of the movable electrode abuts against the second protection unit.

5. The pressure detection device according to claim 4 , wherein the second protection unit comprises an overload protection electrode and a second short-circuit detecting circuit, in which
the overload protection electrode is disposed to the fixed electrode, and the movable electrode is configured to be short-circuited with the fixed electrode upon contacting the overload protection electrode;
the second short-circuit detecting circuit is connected with the fixed electrode and the movable electrode, and generates a second protection signal when detecting that the fixed electrode and the movable electrode are short-circuited, so as to allow a pressure cooking appliance to perform a protective action according to the second protection signal, wherein the pressure sensing assembly is disposed in the lid and connected with the first coupling coil; and
further comprising a controller connected with the other of the second coupling coil and the first coupling coil.

6. The pressure detection device according to claim 2 , wherein the fixed part comprises a first coil, the movable part comprises a movable magnetic core, and the movable magnetic core is configured to move relative to the first coil when the pressure change is sensed, so as to cause an inductance value of the first coil to change.

7. The pressure detection device according to claim 6 , wherein the first coil generates an inductance change according to a displacement change of the movable magnetic core, and causes a resonant frequency change of a sensing circuit;
the detection unit is pre-stored with an air pressure value of the sealed cavity corresponding to the resonant frequency change, and calculates the air pressure of the sealed cavity according to the resonant frequency change.

8. The pressure detection device according to claim 6 , further comprising a first protection unit, at least a part of the first protection unit being disposed in a predetermined protection position in a moving direction of the movable magnetic core, and the first protection unit being configured to cut off power of a device for increasing the air pressure of the sealed cavity when a top of the movable magnetic core abuts against the first protection unit.

9. The pressure detection device according to claim 8 , wherein the first protection unit comprises a first protection electrode, a second protection electrode, and a first short-circuit detecting circuit, in which
the first protection electrode and the second protection electrode are disposed in the predetermined protection position in the moving direction of the movable magnetic core, and are configured to be short-circuited upon contacting the movable magnetic core;
the first short-circuit detecting circuit is connected with the first protection electrode and the second protection electrode, and configured to generate a first protection signal when detecting that the first protection electrode and the second protection electrode are short-circuited, so as to allow a pressure cooking appliance to perform a protective action according to the first protection signal.

10. The pressure detection device according to claim 6 , wherein the detection unit comprises:
a first capacitor connected in parallel with the first coil to constitute a first resonant circuit;
a first induction coil serving as the first coupling coil, and connected in parallel or in series with the first coil in the first resonant circuit; and
a first detection assembly configured to detect a resonant frequency of the first resonant circuit and acquire the pressure intensity in the sealed cavity according to the resonant frequency of the first resonant circuit.

11. The pressure detection device according to claim 10 , wherein the first detection assembly comprises:
a second induction coil serving as the second coupling co

Assignees

• Midea Group Co Ltd

Inventors

• Wu Shuyun
• Gao Anping
• Huang Xinjian
• Xiong Guilin

Classifications

• A47J27/09 Primary

  Safety devices · CPC title

• G01L9/12

  by making use of variations in capacitance {, i.e. electric circuits therefor} · CPC title

• G01L9/14

  involving the displacement of magnets, e.g. electromagnets · CPC title

• A47J45/063

  Knobs, e.g. for lids (A47J45/07 takes precedence) · CPC title

• A47J27/08 Primary

  Pressure-cookers; Lids or locking devices specially adapted therefor · CPC title