A method for detecting the position of a rotary valve of a food processing machine

Abstract

The present application discloses a method for detecting the position of a rotary valve of a food processing machine. The food processing machine includes a rotary valve provided with a magnet, a linear Hall, and a signal control unit electrically connected to the linear Hall. The method includes at least: a signal acquisition stage: the signal control unit acquires the magnetic field strength signal of the magnet during the rotation of the rotary valve through the linear Hall; a signal processing stage: the signal control unit calculates and compares a plurality of the magnetic field strength signals to obtain the change trend of the magnetic field strength signal, and the change trend includes the critical jump of the magnetic field strength signal; a signal recognition stage: the signal control unit recognizes that the rotary valve has turned to the set position according to the critical jump. Through the technical solution of the present invention, the rotary valve can be accurately identified to reach the set position according to the critical jump, eliminating the influence of the rotary valve position deviation, and can also detect the situation of rotary valve blocking to avoid misjudgment.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for detecting the position of a rotary valve of a food processing machine. Background Art

[0002] With the advancement of smart home appliances, food processors with automatic water inlet and / or self-cleaning functions (such as wall breaking machines, soy milk machines, etc.) are becoming more and more popular among contemporary young users. The birth of this automatic water inlet and automatic cleaning function eliminates the tedious process of users adding water and manual cleaning according to the menu, greatly improving the user experience. However, existing food processors with automatic water inlet and / or self-cleaning functions still have the following problems:

[0003] (1) In the prior art, the switching of multiple pipelines inside the aforementioned food processing machine is achieved through a rotary valve: first, a stepper motor is used to drive the rotary valve to rotate, and then a position sensor is used to detect a fixed rotation position to control the rotary valve to switch to a preset position, thereby achieving the switching of the pipeline. However, due to the differences in the sensing distances of the position sensors of different prototypes, it is easy to cause the actual position of the rotary valve to deviate from the set position when the rotary valve rotates, although the sensor detects a signal. In addition, due to the differences in the tightness of the rotary valve installation and the speed of the stepper motor, the actual position of the rotary valve will also deviate from the set position due to inertia after the rotary valve stops rotating.

[0004] In the prior art, some rotary valves also detect their positions through linear Hall: when the magnet rotates to different detection positions, the linear Hall device outputs different voltage signals. The MCU determines the position of the rotary valve by detecting the voltage signal value to realize the function of one Hall device for multiple position detection. For example, the patent with application number 201922288713.3 discloses a position detection scheme for the rotary valve: when the magnet rotates to different detection positions, the linear Hall device outputs different voltage signals, and the main control unit determines the current position of the rotary valve based on different voltage signals. However, this scheme has high requirements on the consistency of the linear Hall output value, and the positions of the rotary valve need to be very close to each other to ensure that a linear Hall can cover the detection range of all positions. Differences in the structure and components of mass-produced machines will still cause the position of the rotary valve to be offset.

[0005] (2) The rotary valve of the existing food processing machine is relatively large in size, which not only occupies structural space, but also has a high cost. For this reason, some people limit the structure on both sides of the rotary valve, use the rotary valve blocking detection to realize the position recognition on both sides, and detect the middle position through sensors. This is not only low-cost, but also can reduce the size of the rotary valve. However, due to the smaller size of the rotary valve, the design margin of the middle sealing port is small. If the rotary valve is slightly offset, the sealing port will leak slurry.

[0006] (3) In order to save the cost of the rotary valve, a limit structure and a stall detection are generally used to realize position identification: a limit is designed at the water inlet and slurry discharge positions. When the rotary valve is rotated to the corresponding position, a stall will occur due to the existence of the limit structure. At this time, the rotary valve can be identified by detecting the stall current. However, if the rotary valve is stalled prematurely due to foreign matter inside the rotary valve, there is a risk of misjudgment. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems in the above-mentioned technology to a certain extent. In order to overcome the shortcomings and deficiencies in the prior art, the present invention provides a method for detecting the position of a rotary valve of a food processing machine to accurately detect whether the rotary valve is in place and eliminate the influence of the rotary valve position deviation.

[0008] To achieve the above object, the present invention adopts the following technical solution: a method for detecting the position of a rotary valve of a food processing machine, the food processing machine comprising a rotary valve provided with a magnet, a linear Hall, and a signal control unit electrically connected to the linear Hall, characterized in that the method at least comprises:

[0009] Signal collection stage: the signal control unit collects the magnetic field strength signal of the magnet during the rotation of the rotary valve through the linear Hall;

[0010] Signal processing stage: the signal control unit calculates and compares the multiple magnetic field strength signals to obtain the change trend of the magnetic field strength signal, wherein the change trend includes the critical jump of the magnetic field strength signal;

[0011] Signal recognition stage: the signal control unit recognizes that the rotary valve turns to the set position according to the critical jump.

[0012] Preferably, the changing trend includes a first trend during the rotation of the rotary valve and a second trend during the rotation of the rotary valve to the set position. In the signal identification stage, when the signal control unit detects that the changing trend jumps from the first trend to the second trend, it is determined that the changing trend produces a critical jump and recognizes that the rotary valve has turned to the set position.

[0013] Preferably, in the signal recognition stage, when the signal control unit detects that the signal value rises twice in succession, it determines that the first trend is a continuous rise, and recognizes that the rotary valve rotates toward the set position;

[0014] When the signal control unit detects that the signal value stops increasing and starts decreasing, it is determined that the change trend jumps from the first trend to the second trend, and the signal control unit recognizes that the rotary valve is completely rotated to the set position.

[0015] Preferably, in the signal identification stage, when the signal control unit detects that the rate of change of the multiple magnetic field strength signal values ​​is a positive number, the change trend is determined to be a first trend, and the rotary valve is identified to be rotating toward the set position;

[0016] When it is detected that the change rate jumps from a positive number to zero, it is determined that the change trend jumps from a first trend to a second trend, and the signal control unit recognizes that the rotary valve is completely rotated to the set position.

[0017] Preferably, the magnet and the linear Hall are symmetrically arranged. When the rotary valve is rotated to the set position, the magnet rotates circumferentially with the rotary valve, and the distance between the magnet and the linear Hall shows a nonlinear change that first decreases rapidly and then decreases slowly. The change trend is the first trend. Only when the rotary valve is rotated to the set position, the distance between the magnet and the linear Hall no longer decreases, so that the change trend collected by the signal control unit jumps from the first trend to the second trend.

[0018] Preferably, the rotary valve includes a water inlet position, a slurry discharge position and a sealing position. During the signal acquisition stage, the linear Hall acquisition magnetic field strength signal when the rotary valve rotates to a set position, and the set position is any one of the water inlet position, the slurry discharge position and the sealing position.

[0019] Preferably, the set position includes a semi-open position for controlling the liquid flow rate, and the signal control unit identifies that the rotary valve turns to the semi-open position according to the critical jump, thereby reflecting the opening degree of the semi-open position.

[0020] Preferably, in the signal acquisition stage, the signal control unit acquires the AD value of the linear Hall K 1 and the calibration value of linear Hall at the factory K ;

[0021] In the signal processing stage, the signal control unit K 1 value and K The values ​​are calculated and compared to obtain K 1 whether the value meets the preset conditions;

[0022] In the signal recognition stage, the signal control unit K If the value 1 does not meet the preset conditions, the rotary valve is identified to be blocked.

[0023] Preferably, in the signal processing stage, the time required for the rotary valve to rotate to the set position at the preset speed is used as the preset time and compared with the actual rotation time of the rotary valve;

[0024] In the signal identification stage, the signal control unit identifies that the rotary valve has an operating failure and issues an alarm based on the fact that the actual rotation time of the rotary valve is greater than three times the preset time.

[0025] The above technical solution of this application has the following beneficial effects:

[0026] 1. In the present invention, a food processing machine includes a rotary valve provided with a magnet, a linear Hall and a signal control unit electrically connected to the linear Hall. The present invention provides a method for detecting the position of a rotary valve of a food processing machine, the method at least comprising: a signal acquisition stage: the signal control unit acquires the magnetic field strength signal of the magnet during the rotation of the rotary valve through the linear Hall; a signal processing stage: the signal control unit calculates and compares a plurality of the magnetic field strength signals to obtain a change trend of the magnetic field strength signal, the change trend includes a critical jump of the magnetic field strength signal; a signal recognition stage: the signal control unit recognizes that the rotary valve has turned to a set position according to the critical jump. In the signal acquisition stage of the scheme, the signal control unit can collect the magnetic field signal strength when the rotary valve runs to any position, thereby forming a continuous signal acquisition process and improving the reliability of signal data; further, the signal control unit calculates and compares the magnetic field signal strength to calculate the change trend of the magnetic field strength signal value in a certain interval, rather than obtaining the magnetic field strength signal value, which greatly reduces the requirements for the consistency of the magnetic field strength signal value, and can exclude the influence of the magnetic strength of the magnet and the distance between the linear Hall and the magnet. The change trend includes a critical jump, which must occur at a certain specific position. The linear Hall shown only needs to cover the detection range of the specific position, thereby greatly reducing the volume of the rotary valve; further, since the critical jump only occurs when the rotary valve is turned to the set position, the signal control unit can identify the rotary valve turning to the set position through the critical jump. This technical solution of identifying the rotary valve reaching the set position through the critical jump, because the signal control unit identifies the change trend of the magnetic field signal strength in the process of the rotary valve approaching the set position, which is a process change, and the critical jump is the change trend of multiple signal values ​​within a certain preset interval, rather than judging the size of a single signal value, therefore, it is easier to avoid misjudgment and improve the accuracy of detecting the rotary valve in place.

[0027] 2. Critical jump refers to the jump from the first trend to the second trend. The rotary valve maintains the first trend while slowly approaching the set position. Only when the rotary valve is fully turned to the set position, the first trend jumps to the second trend, thereby generating a critical jump. The signal control unit can recognize this change and determine whether the rotary valve is in place. Since this is a process detection, this trend change can be accurately detected, thereby improving the accuracy of position detection.

[0028] 3. Due to the fluctuation of the magnetic field strength signal, the signal control unit will detect that the signal value has risen and the rising value is a positive number before the rotary valve is started. Therefore, in order to prevent the misjudgment of the starting point of the rotary valve, the signal control unit of this scheme is configured to recognize that the rotary valve is rotating toward the set position after detecting that the signal value has risen twice in succession. After determining that the rotary valve has really rotated, it will then begin to determine when the change trend jumps from the first trend to the second trend. When a critical jump occurs, it is recognized that the rotary valve has completely rotated to the set position. The rising signal value in the second trend and the initial rising signal value and the rising value being a positive number can be clearly distinguished to avoid misjudgment of the rotary valve position.

[0029] 4. The change trend can also be reflected by calculating and comparing the change rate of the magnetic field strength signal value. When the change rate is a positive number, the change trend is determined to be the first trend, and the rotary valve rotates toward the set position; when the change rate changes from a positive number to zero, the change trend is determined to jump from the first trend to the second trend, and the signal control unit recognizes that the rotary valve is completely rotated to the set position. Similarly, the change rate can be calculated in real time during the rotation of the rotary valve, and the critical jump can be identified based on the change rate value jumping from a positive number to zero, or from a positive number to zero and then to a negative number, thereby accurately judging the position of the rotary valve.

[0030] 5. By symmetrically arranging the magnet and the linear Hall, the distance between the magnet and the linear Hall is constantly changing during the process of the rotary valve turning to the set position. When the rotary valve turns to the set position, the magnet and the linear Hall are closest to each other, and the magnetic field strength signal is the strongest. Furthermore, since the magnet rotates circumferentially with the rotary valve, the distance between the magnet and the linear Hall shows a nonlinear change of first rapidly decreasing and then slowly decreasing as the rotary valve slowly approaches the set position. This nonlinear change causes the change trend to maintain the first trend during the operation of the rotary valve, but in the first trend, its magnetic field strength signal will show a rapid increase first and then a slow increase until it reaches the set position, and then it will slowly increase until it stops increasing, thus showing a critical jump from the first trend to the second trend. This relies on the particularity of the circumferential operation of the rotary valve, which causes the change trend of the magnetic field strength signal to have a critical jump, so the position of the rotary valve can be accurately detected based on this jump signal.

[0031] 6. By setting the setting position to any one of the water inlet position, the pulp discharge position and the sealing position, it is beneficial for the food processor to start working or need to be cleaned and water inlet, and the rotary valve is turned from the sealing position to the water inlet position to ensure that the water inlet position is fully opened; or when the food processor needs to discharge pulp at the end, the rotary valve is turned from the sealing position to the pulp discharge position to ensure that the pulp discharge position is fully opened; or when the food processor has finished water inlet or pulp discharge, the rotary valve can also be turned from the pulp discharge position or the water inlet position to the sealing position. This meets the needs of users at different stages of the food processing process. When water inlet or pulp discharge is required, the water inlet position or the pulp discharge position is fully opened, so that the speed of water inlet or pulp discharge is relatively large, saving working time; when sealing is required, the sealing position completely blocks the cup body mouth to prevent water or pulp leakage, resulting in damage to the components in the main machine and reducing the life of the food processor. At the same time, the leakage of water or pulp will also cause the actual production ratio to change, thereby affecting the taste of the ingredients produced.

[0032] 7. By setting the setting position to a semi-open position for controlling the liquid flow rate, that is, when the rotary valve is turned to the semi-open position, the linear Hall is closest to the magnet, so the signal control unit can identify that the rotary valve is turned to the semi-open position according to the critical jump. This technical solution sets the setting position at the semi-open position. For example, when only a small amount of liquid is needed during food processing, such a semi-open position can meet the actual needs of users and avoid liquid waste caused by too large an opening and too fast a flow rate.

[0033] 8. During the operation of the rotary valve, if the power is cut off due to various reasons, the rotary valve will inevitably stop operating immediately. However, after the power is turned on again, the rotary valve will return to the initial position from the position where it stopped when the power was cut off, and then restart until it reaches the set position, and then stop rotating. In this way, through a specific reset operation, the rotary valve can still be smoothly turned to the set position after the power is turned on again in the case of a sudden power outage, so that the rotary valve can resume normal operation, reduce the failure rate of the rotary valve, and improve the user's operating experience.

[0034] 9. In order to eliminate the fluctuation of the AD value of the linear Hall sensor when it is far away from the magnet due to the differences between different linear Hall sensors, which will have an adverse effect on the subsequent test results, the AD value of the linear Hall sensor will be calibrated at the factory in this solution. K Furthermore, when the rotary valve is turned to a position other than the set position, the linear Hall is away from the magnet. At this time, the AD value of the linear Hall is K 1 and the calibration value of linear Hall at the factory K Close, so K Value and K1 value is close to the preset condition. Since the stall condition when the rotary valve is turned to other positions other than the set position is identified by the motor stall current, when the signal control unit detects K 1 and K When the values ​​differ greatly, K If the value 1 does not meet the preset conditions, it can identify the premature stalling of the motor and improve the reliability of the rotary valve.

[0035] 10. By calculating and comparing the time required for the rotary valve to rotate to the set position at a preset speed with the actual rotation time of the rotary valve as the preset time, the comparison results of the two times can be fed back in time. If an abnormality occurs, an alarm will be issued in time to remind the user to prevent safety risks. Furthermore, the signal control unit can ensure that the rotary valve has enough time to rotate to the set position under normal circumstances based on the actual rotation time of the rotary valve being greater than three times the preset time, thereby avoiding false alarms. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0037] Figure 1 is a schematic diagram of the food processing machine according to an embodiment of the present invention;

[0038] Figure 2 is a flow chart of the rotary valve position detection method of the food processing machine according to an embodiment of the present invention;

[0039] Figure 3 It is a structural explosion diagram of the rotary valve according to an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the connection between the linear Hall and the signal control unit in an embodiment of the present invention;

[0041] Figure 5 It is a schematic diagram of a curve showing a change in the linear Hall AD value versus the valve core position before filtering in an embodiment of the present invention;

[0042] Figure 6 It is a schematic diagram of a curve showing a change in the AD value of a linear Hall sensor after filtering as a function of the position of a valve core according to an embodiment of the present invention;

[0043] Figure 7 It is a schematic diagram of a method for detecting whether a rotary valve is in place or has a fault according to an embodiment of the present invention;

[0044] Figure 8 A schematic diagram of the structure of the valve core according to an embodiment of the present invention;

[0045] Fig. 9 is a cross-sectional view of the valve core according to an embodiment of the present invention;

[0046] Fig.10 Schematic diagram of the valve position and cup opening in a food processor according to an embodiment of the present invention.

[0047] The numbers corresponding to the component names in the figure are as follows:

[0048] S101, signal acquisition stage; S102, signal storage stage; S103, signal processing and identification stage; 1, water tank; 2, motor; 3, water inlet control module; 4, cup cover; 5, crushing cup body; 6, heating module; 7, rotary valve; 71, reduction motor; 72, rotary valve plate; 73, valve shell; 74, magnet; 75, valve core; 751, slurry discharge position; 752, water inlet position; 753, sealing position; 76, valve sleeve; 77, valve seat; 78, slurry outlet nozzle; 8, slurry receiving cup; 9, residual water box. DETAILED DESCRIPTION

[0049] The following description and accompanying drawings fully illustrate specific embodiments of the present invention so that those skilled in the art can practice. The embodiments represent possible variations only, and unless expressly required, individual components and functions are optional, and the order of operations may vary. Herein, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusions, so that the process, method or device including a series of elements includes not only those elements, but also other elements not explicitly listed. In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined arbitrarily with each other.

[0050] The steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. Also, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described can be performed in a sequence different from that shown here.

[0051] The present invention first provides a food processing machine, including a machine base with a main machine built in, a processing chamber arranged on the machine base, and a rotary valve connected to the processing chamber for pipeline conversion. Specifically, an automatic water-adding food processing machine is used as an example for explanation, but it is not limited to automatic water-adding food processing machines, and manual water-adding food processing machines may also be used. Figure 1 As shown, the food processor includes a base with a motor 2, a water control module 3 and other main control components built in, a water tank 1 for supplying water to a grinding cup 5 is provided on one side of the base, and a processing chamber is provided on the other side of the base, the processing chamber includes a grinding cup 5 and a cup cover 4 provided on the grinding cup 5 to prevent food from splashing. A heating module 6 is provided at the bottom of the grinding cup 5, the grinding cup 5 is connected to a rotary valve 7 at its lower side, and a slurry receiving cup 8 and a residual water box 9 are provided below the outlet of the rotary valve 7.

[0052] Usually, the user needs to add water in the water tank 1 to the specified scale line before use, and then add the required ingredients into the grinding cup 5 according to the specific ingredient ratio of the food to be made, and then cover the cup cover 4, press the corresponding function key, and start the food processor. After starting, the mixing knife in the grinding cup 5 stirs and chops the added ingredients, the water in the water tank enters the grinding cup 5 through the pipeline, and the heating module 6 heats and cooks the mixture of ingredients and water. Of course, some foods suitable for cold drinks, such as milk shakes, fruit and vegetable juices, etc., do not need to be heated and cooked by the heating module 6. After the food processing is completed, when the rotary valve 7 is rotated to the pulp discharge position, the pulp is discharged into the pulp receiving cup 8 through the pulp discharge pipeline. After the pulp discharge is completed, the rotary valve 7 is rotated again and turned to the sealing position, and the water tank 1 again delivers water to the grinding cup 5 to clean the grinding cup 5. After cleaning, the rotary valve 7 is rotated again and turned to the water outlet position, and the remaining liquid after cleaning is discharged into the residual water box 9 through the water outlet pipeline. After the drainage is completed, the rotary valve 7 is rotated to the sealing position again to ensure the sealing of the grinding cup body 5, and then drying, disinfection and other operations can be carried out as required.

[0053] Further, such as Figure 3 and Figure 4 As shown, the food processor also includes a rotary valve 7 provided with a magnet 74, a linear Hall and a signal control unit electrically connected to the linear Hall, wherein the rotary valve 7 includes a valve housing 73, a valve sleeve 76 installed in cooperation with the valve housing 73, and a valve core 75 nested in the valve sleeve, the valve core 75 is provided with a magnet that cooperates with the linear Hall for induction, a rotary valve plate 72 is connected between one end surface of the valve housing 73 and the reduction motor 71, the linear Hall is arranged on the rotary valve plate 72, and a valve seat 77 supporting the entire rotary valve 7 is arranged on the other end surface of the valve housing 73, one end of the slurry outlet nozzle 78 passes through the valve seat 77 and is connected to the outlet of the valve core 75, so that the slurry or residual liquid is discharged into the slurry receiving cup 8 or the residual water box 9 through the slurry outlet nozzle 78.

[0054] Further, such as Figure 2 As shown, the method for detecting the rotary valve position of a food processing machine according to the present invention at least includes S101-S103:

[0055] S101, signal collection stage: the signal control unit collects the magnetic field strength signal of the magnet during the rotation of the rotary valve through the linear Hall.

[0056] In the embodiment of the present invention, the signal control unit can collect the magnetic field signal strength when the rotary valve 7 runs to any position through the linear Hall, thereby forming a continuous signal collection process and improving the reliability of signal data.

[0057] S102, signal processing stage: the signal control unit calculates and compares the multiple magnetic field strength signals to obtain the change trend of the magnetic field strength signal, and the change trend includes the critical jump of the magnetic field strength signal.

[0058] The existing method of using linear Hall to identify the position of the rotary valve includes the signal control unit obtaining the value of the magnetic field signal strength when the rotary valve 7 is turned to the set position, and then comparing the obtained signal value with the preset value to identify that the rotary valve 7 has turned to the set position. This solution has high requirements on the consistency of the linear Hall output value, and the positions of the rotary valve 7 need to be very close to ensure that a linear Hall can cover the detection range of all positions. The differences in the structure and components of mass-produced machines will still cause the position of the rotary valve 7 to be offset.

[0059] In order to overcome the detection defects of the above-mentioned existing solutions, in the embodiment of the present invention, the magnetic field signal strength needs to be calculated and compared accordingly to obtain the change trend of the magnetic field strength signal. The change trend must be the change of the magnetic field strength signal within the specified interval, such as whether the magnetic field signal strength value is continuously rising or continuously falling within the interval, or whether the change rate of the magnetic field strength signal within the interval is positive, negative or zero. The interval can be understood as the time interval during the rotation of the rotary valve 7 or the distance change based on the rotation position of the rotary valve 7 as an interval, and the calculation and comparison are performed based on multiple magnetic field strength signals within the same time interval or position interval. The technical solution of the present invention is intended to calculate the change trend of the magnetic field strength signal value in a certain interval, rather than obtaining the magnetic field strength signal value, which greatly reduces the requirements for the consistency of the magnetic field strength signal value, and can exclude the influence of the magnetic strength of the magnet and the distance between the linear Hall and the magnet. And the change trend includes a critical jump, which must occur at a specific position. The linear Hall shown only needs to cover the detection range of the specific position, thereby greatly reducing the volume of the rotary valve 7.

[0060] S103, signal processing stage: the signal control unit recognizes that the rotary valve turns to a set position according to the critical jump.

[0061] Since the critical jump only occurs when the rotary valve 7 is turned to the set position, the signal control unit can identify that the rotary valve 7 has turned to the set position through the critical jump. This technical solution of identifying that the rotary valve 7 has reached the set position through the critical jump is a technical solution that identifies that the rotary valve 7 has reached the set position through the critical jump. Since the signal control unit identifies the changing trend of the magnetic field signal strength in the process of the rotary valve 7 approaching the set position, which is a process change, and the critical jump is the changing trend of multiple signal values ​​within a certain preset interval, rather than judging the size of a single signal value, it is easier to avoid misjudgment of the position and improve the accuracy of detecting that the rotary valve 7 is in place.

[0062] In addition, the critical jump referred to in the embodiment of the present invention refers to the jump from the first trend to the second trend, that is, the rotary valve 7 keeps the first trend while slowly approaching the set position, and only when the rotary valve 7 is completely rotated to the set position, the change trend jumps from the first trend to the second trend, thereby generating a critical jump, and the signal control unit can identify this change to determine whether the rotary valve 7 is rotated to the right position. Since this is a process detection, this trend change can be accurately detected, thereby improving the accuracy of position detection.

[0063] Furthermore, the critical jump only occurs when the rotary valve 7 is turned to the set position because there is a strong correlation between the rotation mode of the rotary valve 7 and the position setting of the magnet 74 and the linear Hall. It can be understood that when the rotary valve 7 reaches the set position according to the critical jump, the rotary valve is turned to the position where the magnet and the linear Hall are directly opposite. In an embodiment of the present invention, the magnet 74 and the linear Hall are symmetrically arranged, and in the process of the rotary valve 7 turning to the set position, the magnet 74 rotates circumferentially with the rotary valve 7. In the process of the circumferential rotation of the rotary valve 7, the distance between the magnet 74 and the linear Hall changes nonlinearly, and the magnetic field strength signal value is related to the distance between the magnet 74 and the linear Hall, so this causes the change in the magnetic field strength signal value to also show nonlinear changes. In general, the smaller the distance between the magnet 74 and the linear Hall, the larger the magnetic field strength signal value. Specifically, in the process of the rotary valve 7 being turned to the set position, the distance between the magnet 74 and the linear Hall shows a nonlinear change of first decreasing rapidly and then decreasing slowly, that is, the distance between the magnet 74 and the linear Hall is always decreasing, and the magnetic field strength signal value shows a nonlinear change of first increasing rapidly and then increasing slowly. The magnetic field strength signal of this process is always increasing, and the change trend of this process is identified as the first trend. When the rotary valve 7 is turned to the set position, the distance between the magnet 74 and the linear Hall reaches the minimum value and no longer decreases, so that the change trend collected by the signal control unit jumps from the first trend to the second trend. The second trend means that within a specified interval, the detected magnetic field signal strength remains almost unchanged and reaches a constant.

[0064] It should be noted that, in the process of the rotary valve 7 rotating from the beginning to the set position, it is actually the valve core 75 that rotates in the circumferential direction, and the magnet 74 is located on the end surface of the valve core. Therefore, the change of the magnetic field strength signal caused by the AD value of the linear Hall with the change of the valve core position is as follows: Figure 5 and Figure 6 As shown. Among them, Figure 5 This is a schematic diagram of the curve of the linear Hall AD value changing with the valve core position before filtering. Figure 6It is a schematic diagram of the curve of the linear Hall AD value after filtering and the change of the valve core position. It should also be pointed out that the linear Hall inputs the magnetic field strength signal to the signal control unit, and the AD module in the signal control unit processes the linear Hall AD value, and the software then processes and outputs it as follows Figure 5 or Figure 6 The curve waveform diagram shown in FIG. 1 shows a theoretical AD value of the present invention of 2048 (12-bit AD).

[0065] In some embodiments of the present invention, the in-position detection of the rotary valve 7 is determined by detecting the rise and fall of the signal value within a specified interval as a change trend. It can be understood that in the signal processing stage, the signal control unit calculates the difference between multiple adjacent magnetic field strength signals to obtain the change trend, wherein the difference is the latter magnetic field strength signal minus the previous magnetic field strength signal.

[0066] It should be noted that the fluctuation of the magnetic field strength signal may cause the signal control unit to detect that the signal value has risen and the rising value is a positive number when the rotary valve 7 has not yet started. Therefore, in order to prevent the misjudgment of the rotation starting point of the rotary valve 7, the present scheme arranges the signal control unit to recognize that the rotary valve 7 is rotating toward the set position after detecting that the signal value has risen twice in succession. At this stage, the change trend is always maintained as the first trend. After determining that the rotary valve 7 has really rotated, it is then determined when the change trend jumps from the first trend to the second trend. When a critical jump occurs, it is recognized that the rotary valve 7 has completely rotated to the set position. The second trend and the initial signal value rise and the rising value are positive numbers, which can be clearly distinguished, thereby avoiding misjudgment of the position of the rotary valve 7.

[0067] Specifically, Figure 6 To expand the explanation, Figure 6 The process from point a' to point b' in the figure is the process of the valve core 75 getting closer and closer to the set position. The AD value of the linear Hall is constantly increasing in the a'b' area. The change trend at this time is defined as the first trend. At point b', the AD value of the linear Hall reaches the maximum value, and within the extremely short interval b'c', the AD value of the linear Hall collected by the signal control unit remains unchanged. This is the second trend, that is, at point b' or a certain point in the b'c' area, a critical jump occurs, and the signal control unit recognizes that the rotary valve 7 is turned to the set position. Figure 5 Points a, b, and c correspond to Figure 6 The meaning of the process is the same as that of point a', point b', and point c'. Figure 5 The curve diagram fluctuates because it has not been filtered, which will not be discussed here.

[0068] In some embodiments of the present invention, the detection of the position of the rotary valve 7 is determined by detecting the change rate of the magnetic field signal strength within a specified interval. The change rate is the difference of the magnetic field strength signal within the specified interval divided by the interval. When the change rate is a positive number, the change trend is determined to be the first trend, and the rotary valve 7 rotates toward the set position, that is, Figure 6 The slope of the curve at any interval in the a'b' region shown in is positive; when the rate of change changes from positive to zero, that is, Figure 6 In the b'c' region, the magnetic field signal intensity remains unchanged, the slope of the curve is zero, and it is determined that the change trend jumps from the first trend to the second trend. The signal control unit recognizes that the rotary valve 7 is completely rotated to the set position. The curve in the area after c' shows a nonlinear decline, which indicates that the rotary valve 7 begins to move away from the set position again. This scheme calculates the rate of change in real time, and identifies the critical jump based on the value of the rate of change jumping from a positive number to zero, or from a positive number to zero and then to a negative number, so as to accurately determine the position of the rotary valve 7. It should be noted that the b'c' region is an extremely small interval, and as long as the rotary valve 7 has an actual deviation, it will not fall within this area. Therefore, this scheme can accurately determine whether the rotary valve 7 has reached the set position.

[0069] It can be understood that when the rotary valve 7 is rotated to the set position, it can also be the time when the linear Hall is farthest from the magnet, and when the rotary valve 7 is in the initial position, it is the moment when the linear Hall is closest to the magnet. Under this scheme, the signal control unit can also recognize that the rotary valve 7 has reached the set position through critical jumps.

[0070] In some embodiments, the control flow of the method for detecting the position or failure of the rotary valve 7 is as follows: Figure 7 As shown, the following steps are included: (1) the motor controls the rotary valve to work. When the stepper motor works, the rotary valve starts to rotate and enters step (2); (2) it is determined whether the working time of the rotary valve is greater than the preset maximum working time T of the rotary valve. If it exceeds T, the rotary valve is identified to be blocked and an alarm is issued to prompt the user. If it does not exceed T, the AD value of the linear Hall is accumulated n times to obtain an average value, where n is preferably 16 times; (3) it is determined whether the AD value of the linear Hall is greater than the sum of the reference value and the minimum change amount. In other words, whether the AD value of the linear Hall increases and the increase value is greater than zero. If so, it enters step (4); (4) it is determined whether the AD value of the linear Hall continues to increase. In other words, when the AD value of the linear Hall increases twice in succession, it enters step (5). If not, it returns to the previous step or step (1); (5) it is determined whether the change rate of the AD value of the linear Hall is less than the set threshold a. It should be noted that the threshold a is actually the change rate when the rotary valve reaches the set position and the change rate is zero at this time. If so, it is determined that the rotary valve is in place and the motor is stopped. If not, it continues to return to the previous step until the change rate is less than the set threshold a.

[0071] It should be noted that the AD value of the linear Hall is accumulated n times to obtain the average value in step (2) in order to solve the problem of Figure 5 The AD value fluctuation problem of the linear Hall is shown in . The interference is eliminated by the cumulative filtering process in step (2), thus obtaining the following Figure 6 In the stable signal detection process shown, the curve waveform is smooth and has no burrs, thereby avoiding misjudgment of the position of the rotary valve 7.

[0072] In some embodiments, in order to enable timely alarm to alert the user when the rotary valve 7 has an operational failure, in the signal processing stage, the time required for the rotary valve 7 to rotate to the set position at a preset speed is taken as the preset time and compared with the actual rotation time of the rotary valve 7; by taking the time required for the rotary valve 7 to rotate to the set position at a preset speed as the preset time and comparing with the actual rotation time of the rotary valve 7, the comparison result of the two times can be fed back in time, and if any abnormality occurs, an alarm will be issued in time to alert the user to prevent safety risks.

[0073] In the signal recognition stage, the signal control unit recognizes that the rotary valve 7 has an operational failure and issues an alarm according to the fact that the actual rotation time of the rotary valve 7 is greater than three times the preset time. The signal control unit can ensure that the rotary valve 7 has enough time to rotate to the set position under normal circumstances according to the fact that the actual rotation time of the rotary valve 7 is greater than three times the preset time, thereby avoiding false alarms.

[0074] It should be noted that the time required for the rotary valve 7 to rotate to the set position at a preset speed is taken as the preset time. The preset time is the maximum working time T of the rotary valve. T is set according to the normal time for the rotary valve 7 to rotate from the initial position to the set position, such as from the slurry discharge position 751 or the water inlet position 752 to the sealing position 753. Preferably, T is three times the normal time for the rotary valve 7 to rotate from the initial position to the set position.

[0075] In some embodiments, Figure 3 as well as Figures 8 to 10 As shown, the rotary valve 7 includes a valve core 75, and a water inlet position 752, a slurry discharge position 751 and a sealing position 753 are provided on the side wall of the valve core 75. The magnet 74 is provided on the central axis of any one of the three positions. The valve housing 73 is provided with a cup body opening that can correspond to any one of the three positions respectively. One end of the valve core is a sealing opening, and the other end is an opening, and the opening is connected to the slurry outlet nozzle 78. In the signal acquisition stage, the linear Hall collects the magnetic field strength signal when the rotary valve 7 rotates to the set position, and the set position is any one of the water inlet position 752, the slurry discharge position 751 and the sealing position 753.

[0076] This embodiment sets the set position to any one of the water inlet position 752, the pulp discharge position 751 and the sealing position 753, so that when the food processor starts working or needs to be cleaned and water is taken in, the rotary valve 7 is turned from the sealing position 753 to the water inlet position 752 to ensure that the water inlet position 752 is completely aligned with the cup body mouth, that is, the water inlet position 752 is fully opened; or when the food processor is finished and pulp needs to be discharged, the rotary valve 7 is turned from the sealing position 753 to the pulp discharge position 751 to ensure that the pulp discharge position 751 is fully opened; or when the food processor has finished water intake or pulp discharge, the rotary valve 7 can also be turned from the pulp discharge position 751 or the water inlet position 752 to the sealing position 753. This meets the needs of users at different stages of the food processing process. When water is needed to be introduced or slurry is discharged, the water inlet position 752 or the slurry discharge position 751 is fully opened to increase the speed of water introduction or slurry discharge, saving working time. When sealing is needed, the sealing position 753 completely blocks the cup body opening to prevent water or slurry from leaking, which would damage unnecessary components in the main unit and reduce the life of the food processor. At the same time, the leakage of water or slurry would also cause changes in the actual production ratio, thereby affecting the taste of the prepared ingredients.

[0077] In some embodiments, the set position includes a semi-open position for controlling the flow rate of the liquid, that is, the magnet 74 is offset from the central axis of the set position. When the rotary valve 7 is turned to the semi-open position, the linear Hall is closest to the magnet 74, so the signal control unit can identify that the rotary valve 7 is turned to the semi-open position according to the critical jump, thereby reflecting the opening degree at the semi-open position. This technical solution sets the set position at the semi-open position. For example, when only a small amount of liquid is needed during food processing, such a semi-open position can meet the actual needs of the user and avoid waste of liquid caused by too large an opening and too fast a flow rate.

[0078] It is understandable that multiple magnets 74 may be provided on the valve core 75 so that when different opening requirements are detected, corresponding positions can be detected according to different jump signals. If multiple magnets are provided, it is necessary to ensure that the magnetic field strength between the magnets 74 has almost no influence, so that the rotary valve 7 can be identified to be turned to different positions according to the critical jump of the magnetic field strength signal at the position of different opening and closing sizes, thereby further reflecting the opening and closing degrees of different half-opening positions.

[0079] In some embodiments, during the actual operation of the rotary valve 7, there may be a phenomenon that the rotary valve 7 stops operating immediately due to power failure due to various reasons. To ensure that the rotary valve 7 can continue to automatically rotate to the set position after power is turned on. This solution arranges that after the rotary valve 7 is powered on again, the rotary valve 7 will return to the initial position from the position where it stopped when the power was turned off, and then restart until it reaches the set position, and then stop rotating. In this way, through a specific reset operation, the rotary valve 7 can still be smoothly rotated to the set position after power is turned on again in the event of a sudden power failure, so that the rotary valve 7 can resume normal operation, reduce the failure rate of the rotary valve 7, and improve the user's operating experience. At the same time, this solution can ensure the operating stroke of the rotary valve 7, and avoid the signal control unit being unable to accurately detect the changing trend of the magnetic field strength signal due to the short stroke when the rotary valve 7 rotates to the linear Hall position.

[0080] In some embodiments, in order to eliminate the fluctuation of the AD value of the linear Hall due to the differences between different linear Halls when the linear Hall is far away from the magnet 74, which has an adverse effect on the subsequent detection results, the AD value of the linear Hall is calibrated at the factory in this solution. K .

[0081] Furthermore, when the rotary valve 7 is rotated to a position other than the set position, the linear Hall is away from the magnet 74. At this time, the AD value of the linear Hall is K 1 and the calibration value of linear Hall at the factory K Close, so K Value and K 1 value is close to the preset condition. Specifically, the preset condition refers to the rotary valve 7 being in a non-set position. K 1 value calculation satisfies K ×0.95< K 1< K ×1.05. K 1 is used as the reference value of the linear Hall, which can eliminate the deviation of the AD value of the linear Hall caused by the mechanism difference of the rotary valve 7.

[0082] In addition, since the stalling condition when the rotary valve 7 is rotated to other positions other than the set position is identified by the motor stalling current, when the signal control unit detects K 1 and K When the values ​​differ greatly, K If the value 1 does not meet the preset conditions, the motor can be identified to be locked in advance, which can solve the problem of misjudgment when the existing rotary valve 7 determines the position through the locked current, and improve the reliability of the rotary valve 7. K 1 Satisfaction K ×0.95< K 1< K ×1.05, it is recognized that the rotary valve 7 is normal and K1 is used as the reference value for subsequent judgment of the AD value change of the linear Hall; otherwise, if it is not satisfied, that is, when K 1< K ×1.05 or K 1> K ×0.95, it is considered that the rotary valve 7 is blocked and an alarm is given.

[0083] Those skilled in the art should understand that although the embodiments disclosed in the embodiments of the present invention are as above, the contents are only embodiments adopted for facilitating the understanding of the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. Any person skilled in the art in the field to which the embodiments of the present invention belong may make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the embodiments of the present invention, but the scope of patent protection of the embodiments of the present invention shall still be subject to the scope defined by the attached claims and their equivalents.

Claims

1. A method for detecting the position of a rotary valve of a food processing machine, wherein the food processing machine comprises a rotary valve provided with a magnet, a linear Hall, and a signal control unit electrically connected to the linear Hall, wherein: The method at least comprises: Signal acquisition stage: the signal control unit continuously obtains the AD value of the magnetic field strength signal of the magnet during the rotation of the rotary valve through the linear Hall; Signal processing stage: the signal control unit calculates and compares the AD values ​​of the acquired multiple magnetic field strength signals to obtain the change rate of the AD value of the magnetic field strength signal, and determines the change trend according to the change rate of the AD value of the magnetic field strength signal; The change trend includes a first trend when the rotary valve is in a rotating process, and a second trend when the rotary valve is in a set position; Signal recognition stage: when the rate of change of the AD value of the magnetic field strength signal is a positive number, the signal control unit recognizes the first trend that the rotary valve is in the rotation process; when the rate of change of the AD value of the magnetic field strength signal is zero, the signal control unit recognizes the second trend that the rotary valve is in the set position.

2. A method for detecting the position of a rotary valve of a food processing machine according to claim 1, characterized in that: In the signal recognition stage, when the signal control unit detects that the AD value of the magnetic field strength signal of the magnet rises twice in succession, it is determined as a first trend, and it is recognized that the rotary valve rotates toward the set position; When the signal control unit detects that the AD value of the magnetic field strength signal of the magnet rises to a maximum value, it is determined that the change trend jumps from the first trend to the second trend, and the signal control unit recognizes that the rotary valve is completely rotated to the set position.

3. The method for detecting the position of a rotary valve of a food processing machine according to claim 1, characterized in that: When the rotary valve rotates to the set position, the magnet rotates along with the rotary valve first quickly and then slowly.

4. The method for detecting the position of a rotary valve of a food processing machine according to claim 1, characterized in that: The rotary valve includes a water inlet position, a slurry discharge position and a sealing position, and the set position is any one of the water inlet position, the slurry discharge position and the sealing position.

5. The method for detecting the position of a rotary valve of a food processing machine according to claim 1, characterized in that: The set position is a semi-open position for controlling the flow rate of the liquid.

6. The method for detecting the position of a rotary valve of a food processing machine according to claim 1, characterized in that: When a power failure occurs during the rotation of the rotary valve, the rotary valve will first return to the initial position after power is restored, and then rotate from the initial position to the set position.

7. The method for detecting the position of a rotary valve of a food processing machine according to claim 1, characterized in that: The linear Hall sensor is preset with a calibration value K at the factory; In the signal processing stage, the signal control unit calculates and compares the AD value and K value of the collected magnetic field strength signal of the magnet to identify whether the rotary valve is blocked.

8. The method for detecting the position of a rotary valve of a food processing machine according to claim 1, characterized in that: The food processor is provided with a preset time, and the actual rotation time of the rotary valve from the initial position to the set position is obtained; When the actual rotation time of the rotary valve is greater than three times of the preset time, the signal control unit identifies that an operation failure of the rotary valve occurs and issues an alarm.

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