Door hinge for household appliance, household appliance and door opening and closing control method for household appliance

Abstract

The invention relates to a door hinge for a household appliance, the household appliance and a door opening and closing control method of the household appliance. The first end of the tongue strip is hinged to the front end of the shell; the output end of the transmission assembly is hinged to the first end of the tongue strip; a first limiting part and a second limiting part are arranged on a power output shaft of the motor; the crank is arranged on a power output shaft of the motor in a sleeving mode, the crank is restrained between the first limiting part and the second limiting part, the crank is rotationally connected with the input end of the transmission assembly, and in the first state, the crank moves back and forth on the power output shaft of the motor to be close to the first limiting part or the second limiting part; and in the second state, the crank abuts against the first limiting part or the second limiting part, so that the crank can be driven by the first limiting part or the second limiting part to rotate along with the motor, and then the transmission assembly is driven to do reciprocating motion in the length direction of the shell. According to the door hinge, manual door opening and closing actions of the hinge under the power failure condition are achieved on the basis of an electric hinge.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and in particular to a door hinge for a household appliance, a household appliance and a method for controlling a door opening and closing of the household appliance. Background Art

[0002] The door bodies of household appliances such as steamers, ovens, and microwave ovens are set on the box bodies by rotating back and forth through hinges on the left and right sides of the lower end. For example, the Chinese utility model patent with patent number ZL 202022529893.2 (authorization announcement number CN213909874U) discloses a hinge device for an air oven.

[0003] There are many kinds of existing hinge structures, but most of them are mechanical manual hinges. For example, Chinese utility model patent No. ZL201320130245.7 (authorization announcement No. CN203175236U) discloses an oven door hinge, which has problems such as being hot to the touch and cannot adapt to the trend of electrification and intelligence. A small number of hinges have achieved electrification functions, but there is a problem that they cannot move during power outages, affecting the use of the entire machine under special circumstances.

[0004] In addition, in the opening and closing control of conventional doors, electric current is mostly used to monitor whether obstacles are encountered to control the stop of the door, such as the doors of refrigerators and cabinets. However, in steam ovens, because the door is flipped open, the center of gravity of the door changes during the entire opening or closing process, and the required torque changes accordingly, causing the current to change. Since the current is unstable during the movement and there are large fluctuations, the traditional current judgment is very poor in the opening and closing of cooking equipment in this type of structure.

[0005] Therefore, it is necessary to further improve the prior art. Summary of the invention

[0006] The first technical problem to be solved by the present invention is to provide a door hinge for household appliances that can realize manual and automatic integration and solve the problem of door opening and closing during power outages in response to the above-mentioned prior art.

[0007] The second technical problem to be solved by the present invention is to provide a household appliance having the above-mentioned door hinge.

[0008] The third technical problem to be solved by the present invention is to provide a method for controlling the switch door of a household appliance as mentioned above, which can adapt to the emergency treatment of the electric door body under various working conditions and has a better control effect.

[0009] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a door hinge for household appliances, comprising:

[0010] The housing is in the shape of a long strip and is used to connect with the inner frame of the household appliance;

[0011] A tongue strip, wherein a first end of the tongue strip is hinged to the front end of the housing through a first pin extending in the width direction of the housing, and a second end of the tongue strip is used to be connected to the door body;

[0012] A transmission assembly is arranged in the housing along the length direction of the housing, and the output end of the transmission assembly is hinged to the first end of the tongue bar through a first hinge shaft parallel to the first pin shaft;

[0013] The invention is characterized in that:

[0014] The motor has a power output shaft arranged along the width direction of the housing, and a first limiting portion and a second limiting portion arranged at intervals are provided on the power output shaft;

[0015] A crank is sleeved on the power output shaft of the motor, and the crank is constrained between the first limit portion and the second limit portion in a manner that it can move along the extension direction of the power output shaft of the motor. The crank is rotationally connected to the input end of the transmission assembly. During the rotation of the motor, the crank has at least the following two states:

[0016] In the first state, the crank moves back and forth on the power output shaft of the motor and approaches the first limit portion or the second limit portion respectively;

[0017] In the second state, the crank abuts against the first limiting portion or the second limiting portion, so that the crank can rotate with the motor driven by the first limiting portion or the second limiting portion, and then drive the transmission assembly to reciprocate along the length direction of the shell.

[0018] In order to realize manual opening and closing of the door, the power output shaft of the motor is provided with an external thread on the outer peripheral wall between the first limit part and the second limit part, and the crank is provided with an internal thread threadedly connected to the external thread on the power output shaft of the motor.

[0019] There are many kinds of structures of the above-mentioned transmission assembly. Preferably, the transmission assembly includes at least two connecting rods arranged in sequence along the length direction of the shell, and two adjacent connecting rods are hinged in sequence. The front end of the connecting rod located in the front is the output end of the transmission assembly, and the rear end of the connecting rod located in the rear is the input end of the transmission assembly.

[0020] Preferably, there are two connecting rods, namely a first connecting rod and a second connecting rod. The front end of the first connecting rod is hinged to the bottom end of the tongue strip through a first hinge shaft, the rear end of the first connecting rod and the front end of the second connecting rod are hinged to the shell through a second hinge shaft, and the rear end of the second connecting rod is rotatably connected to the crank through a third hinge shaft.

[0021] In order to achieve the door opening and closing angle limit, guide slide holes extending along the length direction are respectively opened on the side walls of the shell, and the two ends of the second hinge shaft are respectively inserted into the corresponding guide slide holes. The second hinge shaft can slide back and forth along the length direction of the guide slide holes on both sides and the two ends are respectively guided and matched with the corresponding guide slide holes.

[0022] In order to provide pulling force to the transmission assembly, the door hinge also includes a first pull rod and a second pull rod arranged along the length direction of the shell, the first pull rod and the second pull rod are respectively located on both sides of the second connecting rod, the front end of the first pull rod and the front end of the second pull rod are installed on the second hinge shaft, and the rear end of the first pull rod and the rear end of the second pull rod are hinged to the shell through the first mounting shaft.

[0023] Furthermore, the door hinge also includes a tension spring arranged along the length direction of the shell, a second installation shaft is installed at the rear end of the shell, the front end of the tension spring is installed on the first installation shaft, and the rear end of the tension spring is installed on the second installation shaft.

[0024] In order to monitor different states of the door opening and closing, a first elastic member and a second elastic member are provided on both sides of the crank in the shell. The first elastic member and the second elastic member both act on the crank, and the first elastic member and the second elastic member are always in a compressed state.

[0025] In order to realize the door force detection during the door opening and closing process, it also includes:

[0026] A first stress strain gauge, used for detecting the stress value of the first elastic member;

[0027] A second stress strain gauge is used to detect the stress value of the second elastic member;

[0028] The controller is electrically connected to the first stress strain gauge, the second stress strain gauge and the motor, and is configured to determine the current state of the door body according to the detection results of the first stress strain gauge and the second stress strain gauge, and control the motor to perform corresponding actions.

[0029] The technical solution adopted by the present invention to solve the above second technical problem is: a household appliance, characterized in that: it has a door hinge for a household appliance as described above.

[0030] The technical solution adopted by the present invention to solve the third technical problem is: a door opening and closing control method of the household appliance as described above, characterized in that it comprises the following steps:

[0031] Step 1: determine whether the door of the current household appliance is in a fully open state. If yes, proceed to step 4; if no, proceed to step 2;

[0032] Step 2, determining whether the door of the current household appliance is in a completely closed state, if yes, proceeding to step 5; if no, it indicates that the door of the current household appliance is in a suspended state, and proceeding to step 3;

[0033] Step 3: Detect the stress value p1 of the first elastic member by the first stress strain gauge and detect the stress value p2 of the second elastic member by the second stress strain gauge, calculate the absolute value of the difference |Δp| ​​between p1 and p2, and make the following judgment:

[0034] When |Δp|≤P, P is the preset threshold, and p1>p2, it means that the previous door body encountered an obstacle during the closing process, and the current door body has been reset, and the process goes to step 4;

[0035] When |Δp|≤P, and p1<p2, it means that the previous door body encountered an obstacle during the opening process, and the current door body has been reset, and the process goes to step 5;

[0036] Step 4, executing the door closing action until p1>P1max, P1max is the maximum preset stress value of the first elastic member, and detecting whether the door of the current household appliance is in a completely closed state. If yes, then the process ends; if not, then it is blocked by an obstacle, and then proceeding to step 6;

[0037] Step 5, executing the switch action until p2>P2max, P2max is the maximum preset stress value of the second elastic member, and detecting whether the door of the current household appliance is in the open and fully closed state. If yes, then the process ends; if not, it is blocked by an obstacle, and the process goes to step 6;

[0038] Step 6: Control the motor to rotate in the opposite direction until |Δp|≤P, then the door is reset and the process ends.

[0039] In order to also distinguish the power outage situation, step 3 also includes the following judgment:

[0040] When |Δp|>P, and p1>p2, it means that the door is powered off during the closing process;

[0041] When |Δp|>P and p1<p2, it means that the door is powered off during the opening process.

[0042] In order to realize the door opening and closing control after power failure, the household appliance also includes a backup power supply for powering the motor. The backup power supply works in the state of power failure during the door closing process or the door opening process, and controls the motor to rotate in the opposite direction for n turns, where n is a preset value.

[0043] Compared with the prior art, the advantages of the present invention are as follows: first, by setting the crank sleeve on the power output shaft of the motor, before the crank hits the first limit part and the second limit part, the crank is constrained between the first limit part and the second limit part in a manner that it can move along the extension direction of the power output shaft of the motor, and after the crank hits the first limit part or the second limit part, the power output shaft of the motor will drive the crank to rotate together, and the crank drives the connecting rod assembly to perform linear reciprocating motion forward and backward, thereby driving the tongue bar to perform swing arm motion to achieve door body movement; secondly, in the case of power failure, when manually opening and closing the door, the tongue bar will transfer the motion in the reverse direction to the crank, and due to the self-locking of the motor, the power output shaft of the motor does not rotate, and only the crank rotates, thereby realizing the manual opening and closing of the door. Therefore, the door hinge realizes the hinge manual opening and closing door action in the case of power failure on the basis of the electric hinge, has a simple structure, and can improve the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the structure of a door hinge in an embodiment of the present invention;

[0045] Figure 2 for Figure 1 Schematic diagram of part of the structure (mounting base omitted);

[0046] Figure 3 for Figure 1 Another perspective structural diagram of;

[0047] Figure 4 for Figure 1 Schematic diagram of part of the structure (housing and mounting base omitted);

[0048] Figure 5 for Figure 1 A cross-sectional view along the length direction of the shell;

[0049] Figure 6 for Figure 1 A cross-sectional view along the width direction of the shell;

[0050] Figure 7 for Figure 1 Exploded diagram of . DETAILED DESCRIPTION

[0051] The present invention is further described in detail below with reference to the accompanying drawings.

[0052] The household appliance in this embodiment includes a door body (not shown in the figure) and an inner container (not shown in the figure), and the two sides of the lower end of the door body are respectively hinged to the inner container frame through door hinges. The household appliance in the present invention includes but is not limited to cooking equipment such as steamers, ovens, microwave ovens, dishwashers, refrigerators, disinfection cabinets, etc., or a combination of at least one of the above appliances.

[0053] like Figures 1 to 7 As shown, the door hinge in this embodiment includes a housing 1, a mounting seat a, a tongue strip 2, a connecting rod assembly 3, a motor 4 and a crank 5.

[0054] The shell 1 is in a long strip shape and is connected to the inner tank frame of the household appliance; and the cross section of the shell 1 is in a U-shape with an open end downward, and the cross section of the mounting seat a is in a U-shape with an open end upward. The shell 1 is installed in the mounting seat a, and support blocks 1a for supporting the bottom of the shell 1 are provided on the two side walls of the mounting seat a, so that a space 1b is formed between the bottom of the shell 1 and the bottom of the mounting seat a, and the mounting seat a is fixedly installed with the shell 1, and the space 1b is used for the crank 5 to rotate.

[0055] The first end of the tongue strip 2 is hinged to the front end of the shell 1 through a first pin shaft 13 extending in the width direction of the shell 1, and the second end of the tongue strip 2 is used to connect with the door body; the transmission assembly 3 is arranged in the shell 1 along the length direction of the shell 1, and the output end of the transmission assembly 3 is hinged to the first end of the tongue strip 2 through a first hinge shaft 61 parallel to the first pin shaft 13; the power output shaft 41 of the motor 4 is arranged along the width direction of the shell 1, and the power output shaft 41 is provided with a first limit portion 411 and a second limit portion 412 arranged at intervals; Figure 4 As shown, in this embodiment, the first limiting portion 411 is a step portion, and the second limiting portion 412 is a retaining spring sleeved on the power output shaft 41 of the motor 4; Figure 6 As shown, in this embodiment, the power output shaft 41 of the motor 4 is provided with an external thread on the outer peripheral wall between the first limit portion 411 and the second limit portion 412, and the crank 5 is provided with an internal thread threadedly connected to the external thread on the power output shaft 41 of the motor 4. In this way, the power output shaft 41 of the motor 4 does not rotate, and only the crank 5 rotates, thereby realizing the manual door opening and closing action.

[0056] The crank 5 is sleeved on the power output shaft 41 of the motor 4. The crank 5 is constrained between the first limit portion 411 and the second limit portion 412 in a manner that it can move along the extension direction of the power output shaft 41 of the motor 4. The crank 5 is rotationally connected to the input end of the transmission assembly 3. During the rotation of the motor 4, the crank 5 has at least the following two states: in the first state, the crank 5 moves back and forth on the power output shaft 41 of the motor 4 and approaches the first limit portion 411 or the second limit portion 412 respectively; in the second state, the crank 5 abuts against the first limit portion 411 or the second limit portion 412, so that the crank 5 can rotate with the motor 4 driven by the first limit portion 411 or the second limit portion 412, and then drive the transmission assembly 3 to reciprocate along the length direction of the shell 1.

[0057] The transmission assembly 3 includes at least two connecting rods arranged in sequence along the length direction of the housing 1, and two adjacent connecting rods are hinged in sequence. The front end of the connecting rod located in the front is the output end of the transmission assembly 3, and the rear end of the connecting rod located in the rear is the input end of the transmission assembly 3. Figure 5 and Figure 7 As shown, in this embodiment, there are two connecting rods, namely a first connecting rod 31 and a second connecting rod 32. The front end of the first connecting rod 31 is hinged to the bottom end of the tongue strip 2 through a first hinge shaft 61, the rear end of the first connecting rod 31 and the front end of the second connecting rod 32 are hinged to the housing 1 through a second hinge shaft 62, and the rear end of the second connecting rod 32 is rotatably connected to the crank 5 through a third hinge shaft 63 (as shown in FIG. Figure 7 As shown, the third hinge shaft 63 is arranged on the crank 5, and a bearing is sleeved on the third hinge shaft 63, and the rear end of the second connecting rod 32 is provided with a through hole 321 that can be sleeved on the bearing; in addition, the side walls of the housing 1 are respectively provided with guide sliding holes 11 extending along the length direction thereof, and the two ends of the second hinge shaft 62 are respectively inserted into the corresponding guide sliding holes 11, and the second hinge shaft 62 can slide back and forth along the length direction of the guide sliding holes 11 on both sides, and the two ends are respectively guided and matched with the corresponding guide sliding holes 11. The second hinge shaft 62 is limited by the two ends of the guide sliding hole 11, so as to realize the control of the opening and closing angle of the door.

[0058] like Figure 4 and Figure 7 As shown, the door hinge also includes a first pull strip 71, a second pull strip 72 and a tension spring 9 arranged along the length direction of the shell 1. The first pull strip 71 and the second pull strip 72 are respectively located on both sides of the second connecting rod 32. The front end of the first pull strip 71 and the front end of the second pull strip 72 are installed on the second hinge shaft 62, and the rear end of the first pull strip 71 and the rear end of the second pull strip 72 are hinged to the shell 1 through the first mounting shaft 81. The second mounting shaft 82 is installed at the rear end of the shell 1, the front end of the tension spring 9 is installed on the first mounting shaft 81, and the rear end of the tension spring 9 is installed on the second mounting shaft 82.

[0059] like Figure 3 As shown, the housing 1 is further provided with a first elastic member 101 and a second elastic member 102 located on both sides of the crank 5. The first elastic member 101 and the second elastic member 102 both act on the crank 5. The first elastic member 101 and the second elastic member 102 are always in a compressed state. In this embodiment, the first elastic member 101 and the second elastic member 102 are both springs, and in order to prevent the springs from moving, as shown in FIG. Figure 7 As shown, two positioning posts 12 are provided on the inner wall of the housing 1 and are arranged toward the crank 5 , and each spring is sleeved on the corresponding positioning post 12 .

[0060] In addition, the present embodiment also includes a first stress strain gauge (not shown in the figure), a second stress strain gauge (not shown in the figure) and a controller (not shown in the figure), the first stress strain gauge is used to detect the stress value of the first elastic member 101, and the second stress strain gauge is used to detect the stress value of the second elastic member 102; the controller is electrically connected to the first stress strain gauge, the second stress strain gauge and the motor 4, and is configured to: determine the current state of the door body according to the detection results of the first stress strain gauge and the second stress strain gauge, and control the motor 4 to perform corresponding actions.

[0061] In this embodiment, the power output shaft 41 of the motor 4 rotates, and the crank 5 preferably moves horizontally to the left or right under the action of the thread. During this process, the door body does not move, which is called "idle stroke". After the crank 5 encounters the first limit part 411 or the second limit part 412, the power output shaft 41 of the motor 4 will drive the crank 5 to rotate together, and the crank 5 drives the second hinge shaft 62 to perform a straight reciprocating motion forward and backward, and then drives the first connecting rod 31 to drive the tongue bar 2 to perform a swing arm motion, so as to realize the movement of the door body. During the whole process, the tension spring 9 provides a pulling force to assist in pulling the second hinge shaft 62; and in the case of power failure, when the door is manually opened and closed, the tongue bar 2 will transmit the motion in the reverse direction to the crank 5. Due to the self-locking of the motor, the power output shaft 41 of the motor 4 does not rotate. By utilizing the thread between the crank 5 and the power output shaft 41 of the motor 4, only the crank 5 rotates along the thread on the power output shaft 41 of the motor 4, thereby realizing the action of manually opening and closing the door.

[0062] The above-mentioned household appliance door opening and closing control method comprises the following steps:

[0063] Step 1: determine whether the door of the current household appliance is in a fully open state. If yes, proceed to step 4; if no, proceed to step 2;

[0064] Step 2, determining whether the door of the current household appliance is in a completely closed state, if yes, proceeding to step 5; if no, it indicates that the door of the current household appliance is in a suspended state, and proceeding to step 3;

[0065] Step 3: Detect the stress value p1 of the first elastic member by the first stress strain gauge and detect the stress value p2 of the second elastic member by the second stress strain gauge, calculate the absolute value of the difference |Δp| ​​between p1 and p2, and make the following judgment:

[0066] When |Δp|≤P, P is the preset threshold, and p1>p2, it means that the previous door body encountered an obstacle during the closing process, and the current door body has been reset, and the process goes to step 4;

[0067] When |Δp|≤P, and p1<p2, it means that the previous door body encountered an obstacle during the opening process, and the current door body has been reset, and the process goes to step 5;

[0068] Step 4, executing the door closing action until p1>P1max, P1max is the maximum preset stress value of the first elastic member, and detecting whether the door of the current household appliance is in a completely closed state. If yes, then the process ends; if not, then it is blocked by an obstacle, and then proceeding to step 6;

[0069] Step 5, execute the switch action until p2>P2max, P2max is the maximum preset stress value of the stress of the second elastic member, and detect whether the door of the current household appliance is in the open and fully closed state. If yes, then end; if not, it is blocked by an obstacle, and go to step 6; the above P2max and P1max can also be the same value;

[0070] Step 6: Control the motor to rotate in the opposite direction until |Δp|≤P, then the door is reset and the process ends.

[0071] Step 3 also includes the following judgment: when |Δp|>P, and p1>p2, it means that the door body is powered off during the closing process; when |Δp|>P, and p1<p2, it means that the door body is powered off during the opening process.

[0072] The household appliance also includes a backup power supply for powering the motor. The backup power supply can be a supercapacitor connected in series in the power supply circuit, which can be charged when the power supply circuit is not powered on, and the supercapacitor is quickly discharged after the power supply circuit is powered off. The backup power supply works when the power is off during the door closing process or the door opening process, and controls the motor to rotate in the opposite direction for n turns, where n is a preset value. In this embodiment, after the motor rotates in the opposite direction for n turns, |Δp|>P, so it can be distinguished whether the hovering is caused by an obstacle or a power outage. At this time, the door is in a half-open state, and the user can manually open the door completely to take out the food, or choose to close it completely.

Claims

1. A door hinge for a household appliance, comprising: The housing (1) is in the shape of a long strip and is used to be connected to the inner frame of the household appliance; A tongue strip (2), wherein a first end of the tongue strip (2) is hinged to a front end of the housing (1) via a first pin shaft (13) extending in a width direction of the housing (1), and a second end of the tongue strip (2) is used to be connected to a door body of the household appliance; A transmission assembly (3) is arranged inside the housing (1) along the length direction of the housing (1), and an output end of the transmission assembly (3) is hingedly connected to a first end of the tongue strip (2) via a first hinge shaft (61) parallel to the first pin shaft (13); The invention is characterized in that it also includes: A motor (4), wherein a power output shaft (41) is arranged along the width direction of the housing (1), and a first limiting portion (411) and a second limiting portion (412) arranged at intervals are provided on the power output shaft (41); A crank (5) is sleeved on a power output shaft (41) of a motor (4); the crank (5) is constrained between a first limit portion (411) and a second limit portion (412) in a manner that the crank (5) can move along an extension direction of the power output shaft (41) of the motor (4); the crank (5) is rotationally connected to an input end of a transmission assembly (3); and during the rotation of the motor (4), the crank (5) has at least the following two states: In the first state, the crank (5) moves back and forth on the power output shaft (41) of the motor (4) and approaches the first limiting portion (411) or the second limiting portion (412) respectively; In the second state, the crank (5) abuts against the first limiting portion (411) or the second limiting portion (412), so that the crank (5) can rotate along with the motor (4) under the drive of the first limiting portion (411) or the second limiting portion (412), and then drive the transmission assembly (3) to perform reciprocating motion along the length direction of the housing (1).

2. The door hinge according to claim 1, characterized in that: The power output shaft (41) of the motor (4) is provided with an external thread on the outer peripheral wall between the first limiting portion (411) and the second limiting portion (412), and the crank (5) is provided with an internal thread threadedly connected to the external thread on the power output shaft (41) of the motor (4).

3. The door hinge according to claim 2, characterized in that: The transmission assembly (3) comprises at least two connecting rods arranged in sequence along the length direction of the housing (1), and two adjacent connecting rods are hinged in sequence. The front end of the connecting rod located at the front is the output end of the transmission assembly (3), and the rear end of the connecting rod located at the rear is the input end of the transmission assembly (3).

4. The door hinge according to claim 3, characterized in that: There are two connecting rods, namely a first connecting rod (31) and a second connecting rod (32). The front end of the first connecting rod (31) is hinged to the bottom end of the tongue strip (2) via a first hinge shaft (61), the rear end of the first connecting rod (31) and the front end of the second connecting rod (32) are hinged to the shell (1) via a second hinge shaft (62), and the rear end of the second connecting rod (32) is rotatably connected to the crank (5) via a third hinge shaft (63).

5. The door hinge according to claim 4, characterized in that: The side walls of the housing (1) are respectively provided with guide sliding holes (11) extending along the length direction thereof, and the two ends of the second hinge shaft (62) are respectively inserted into the corresponding guide sliding holes (11). The second hinge shaft (62) can slide back and forth along the length direction of the guide sliding holes (11) on both sides, and the two ends are respectively guided and matched with the corresponding guide sliding holes (11).

6. The door hinge according to claim 5, characterized in that: The door hinge also includes a first pull bar (71) and a second pull bar (72) arranged along the length direction of the shell (1), the first pull bar (71) and the second pull bar (72) are respectively located on both sides of the second connecting rod (32), the front end of the first pull bar (71) and the front end of the second pull bar (72) are installed on the second hinge shaft (62), and the rear end of the first pull bar (71) and the rear end of the second pull bar (72) are hinged on the shell (1) through the first installation shaft (81).

7. The door hinge according to claim 6, characterized in that: The door hinge also includes a tension spring (9) arranged along the length direction of the shell (1), and a second mounting shaft (82) is installed at the rear end of the shell (1), the front end of the tension spring (9) is installed on the first mounting shaft (81), and the rear end of the tension spring (9) is installed on the second mounting shaft (82).

8. The door hinge according to any one of claims 1 to 7, characterized in that: A first elastic member (101) and a second elastic member (102) are also provided in the housing (1) and are located on both sides of the crank (5); the first elastic member (101) and the second elastic member (102) both act on the crank (5); and the first elastic member (101) and the second elastic member (102) are always in a compressed state.

9. The door hinge according to claim 8, characterized in that: Also includes: A first stress strain gauge, used for detecting the stress value of the first elastic member (101); A second stress strain gauge, used for detecting the stress value of the second elastic member (102); The controller is electrically connected to the first stress strain gauge, the second stress strain gauge and the motor (4), and is configured to determine the current state of the door body according to the detection results of the first stress strain gauge and the second stress strain gauge, and control the motor (4) to perform corresponding actions.

10. A household appliance, characterized in that: A door hinge for a household appliance as claimed in claim 9.

11. A method for controlling the opening and closing of a household appliance as claimed in claim 10, characterized in that The steps include: Step 1: determine whether the door of the current household appliance is in a fully open state. If yes, proceed to step 4; if no, proceed to step 2; Step 2, determining whether the door of the current household appliance is in a completely closed state, if yes, proceeding to step 5; if no, it indicates that the door of the current household appliance is in a suspended state, and proceeding to step 3; Step 3: Detect the stress value p1 of the first elastic member by the first stress strain gauge and detect the stress value p2 of the second elastic member by the second stress strain gauge, calculate the absolute value of the difference |Δp| ​​between p1 and p2, and make the following judgment: When |Δp|≤P, P is the preset threshold, and p1>p2, it means that the previous door body encountered an obstacle during the closing process, and the current door body has been reset, and the process goes to step 4; When |Δp|≤P, and p1<p2, it means that the previous door body encountered an obstacle during the opening process, and the current door body has been reset, and the process goes to step 5; Step 4, executing the door closing action until p1>P1max, P1max is the maximum preset stress value of the first elastic member, and detecting whether the door of the current household appliance is in a completely closed state. If yes, then the process ends; if not, then it is blocked by an obstacle, and then proceeding to step 6; Step 5, executing the switch action until p2>P2max, P2max is the maximum preset stress value of the second elastic member, and detecting whether the door of the current household appliance is in the open and fully closed state. If yes, then the process ends; if not, it is blocked by an obstacle, and the process goes to step 6; Step 6: Control the motor to rotate in the opposite direction until |Δp|≤P, then the door is reset and the process ends.

12. The door opening and closing control method according to claim 11, characterized in that: The step 3 also includes the following judgment: When |Δp|>P, and p1>p2, it means that the door is powered off during the closing process; When |Δp|>P and p1<p2, it means that the door is powered off during the opening process.

13. The door opening and closing control method according to claim 12, characterized in that: The household appliance also includes a backup power supply for supplying power to the motor. The backup power supply works in a power-off state during the door closing process or the door opening process, and controls the motor to rotate in the opposite direction for n turns, where n is a preset value.

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