CN110553077B - Control method of electronic water valve - Google Patents

Abstract

A control method of an electronic water valve at least comprises a valve core and a direct current motor, the electronic water valve is provided with a position detection module, and the control method at least comprises the following steps: electrifying to start the electronic water valve; the control valve core is reset to a first position; controlling the rotating speed of the direct current motor to be a first rotating speed, and entering a first process; acquiring the current position of the valve core through a position detection module to judge whether the first process is finished; when the first process is not finished, controlling the direct current motor to maintain the first rotating speed; when the first process is judged to be finished, controlling the direct current motor to be switched to a second rotating speed, and entering a second process; wherein the first rotational speed is less than the second rotational speed. According to the invention, through the change of the rotating speed of the motor, the output torque of the motor is matched with the required torque of the electronic water valve in different stages, so that the risk of locked rotor is reduced.

Description

Control method of electronic water valve

Technical Field

The invention relates to the technical field of fluid control, in particular to a control method of a water valve.

Background

The electronic water valve is generally composed of two parts, one part is a valve body part, and the other part is an actuator for controlling the opening degree. The actuator includes a driving portion including a motor.

When the valve core is at different positions, the friction torque of the valve seat to the valve core may be different, and the driving part makes the valve plate continue to rotate mainly by overcoming the friction torque between the valve core and the valve seat or the valve shell. At this time, if the output torque of the driving part is smaller than or close to the friction torque, the electronic water valve may be locked. The water valve is blocked, so that a series of problems can be caused, such as overheating of a motor, failure of a valve core to reach a specified position and the like.

When the valve is fully closed, the friction force distance between the valve seat and the valve core is large, the friction force distance in the middle process is small, generally, the direct current motor is started at a low speed for a period of time and then switched to operate at a high speed and a constant speed until the direct current motor is closed. However, this control method cannot determine whether the vehicle has entered a normal operating state, and therefore, there is a possibility that a locked-rotor occurs.

Disclosure of Invention

In order to solve the above technical problem, a technical solution of the present invention provides a control method for an electronic water valve, where the electronic water valve at least includes a valve core and a dc motor, and the control method includes:

electrifying to start the electronic water valve;

controlling the valve core to reset to a first position;

controlling the rotating speed of the direct current motor to be a first rotating speed, and entering a first process;

acquiring the current position of the valve core through a position detection module to judge whether the first process is finished;

when the first process is judged not to be finished, controlling the direct current motor to maintain a first rotating speed;

when the first process is judged to be finished, controlling the direct current motor to be switched to a second rotating speed, and entering a second process;

wherein the first rotational speed is less than the second rotational speed.

According to the technical scheme, whether the first process of the relatively high torque is finished or not is judged, and then the second process of switching the rotating speed to the relatively low torque is carried out, so that the output torque of the motor is matched with the required torque of the electronic water valve in different stages, and the risk of locked rotor can be reduced.

Drawings

FIG. 1 is a schematic diagram showing an output torque and a required torque in a conventional control manner;

FIG. 2 is a schematic view of a first embodiment of the electronic water valve control system;

FIG. 3 is a schematic flow chart diagram illustrating a first embodiment of a method of controlling an electronic water valve;

FIG. 4 is a schematic flow diagram of a preferred embodiment of the control method for the electronic water valve of FIG. 3;

FIG. 5 is a schematic diagram illustrating motor speed and output torque for the control method of FIG. 4;

FIG. 6 is a schematic diagram showing an output torque and a required torque in the first embodiment of the control method;

FIG. 7 is a schematic diagram showing an output torque and another required torque in a conventional control manner;

FIG. 8 is a flow chart of an electronic water valve control method in a second embodiment of the control method;

FIG. 9 is a schematic diagram showing the motor speed and output torque in a second embodiment of the control method;

FIG. 10 is a schematic diagram showing an output torque and a required torque in the second embodiment of the control method;

FIG. 11 is a schematic diagram showing motor speed versus time in a third embodiment of the control method;

FIG. 12 shows a schematic cross-sectional view of a first embodiment of a valve body structure;

FIG. 13 shows a schematic top view of a second embodiment of a valve body structure;

FIG. 14 is a schematic top view illustrating a valve cartridge of the electronic water valve of FIG. 12 in a first position;

FIG. 15 is a schematic diagram illustrating a top view of the valve cartridge of the electronic water valve of FIG. 12 during operation;

FIG. 16 is a schematic illustration of a top view of the valve cartridge of the electronic water valve of FIG. 12 in a second position;

FIG. 17 shows a schematic top view of a third embodiment of a valve body structure;

FIG. 18 depicts a schematic view of a second embodiment of an electronic water valve control system;

FIG. 19 depicts a schematic view of a third embodiment of an electronic water valve control system;

FIG. 20 is a schematic diagram showing motor speed versus DC motor steps for a fourth embodiment of the control method;

fig. 21 shows a schematic flow chart of a fifth embodiment of the control method.

Detailed Description

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

The electronic water valve at least comprises a valve core and a direct current motor, and the power output part of the direct current motor is in transmission connection or direct connection with the valve core.

The valve core may be in the form of a rotary. When the valve is opened or closed, the valve core moves for a certain distance after the valve port is completely closed or opened, and then the valve core reaches the position of stopping rotation, and at the moment, larger motor driving torque is needed. The first and second positions are the positions of the valve core which stops rotating and are determined by the mechanical structure, and the first and second positions are respectively positioned at two ends of the valve core stroke. Specifically, in an embodiment, as shown in fig. 12, the valve core is a first valve plate 22, the first valve plate 22 is in a rotating form, the dc motor can drive the first valve plate 22 to rotate, and the first position and the second position are respectively located at two ends of a stroke of the first valve plate 22. As shown in fig. 14, in the first position of the present embodiment, the valve port 121 is fully opened, and it can be seen that the first valve sheet 22 is still a distance away from the edge of the valve port 121 (see the portion circled by the dotted line in fig. 14); as shown in fig. 16, the second position is a state in which the valve port 121 is fully closed.

As shown in fig. 1, if the first valve plate rotation angle is θ, the range of the rotation angle of the first valve plate 22 is 0 to θ 3, the rotation angle of the first valve plate 22 to the first position is 0, the rotation angle to the second position is θ 3, and θ 3 may also be referred to as a maximum rotation angle. The driving torque of the motor required by the rotation angle of the first valve plate in a range from theta 1 to theta 3 (namely, a range II in the graph 1) is smaller than the driving torque of the motor required by the rotation angle in a range from 0 to theta 1 (namely, a range I in the graph 1).

For a water valve driven by a motor, in the output torque of a traditional control mode, a direct current motor is started at a low speed, and the direct current motor is accelerated to a target speed after being started for a period of time. Because the output torque of the motor is in inverse proportion to the operation speed, the friction force to be overcome is large in the starting stage, the speed of the motor is low in order to meet the requirement of the valve opening torque, and the output torque of the motor is large, so that the requirement of the valve opening torque can be met. Generally, the valve plate is accelerated to reach the target speed after running for a set time, the torque is greatly reduced, and if the valve plate does not run out of a range I with larger friction force at the moment, the water valve has the risk of stalling.

Therefore, as shown in fig. 3, a control method of an electronic water valve of the present embodiment at least includes: electrifying to start the electronic water valve;

the control valve core is reset to a first position;

controlling the rotating speed of the direct current motor to be a first rotating speed, and entering a first process;

acquiring the current position of the valve core through a position detection module to judge whether the first process is finished;

when the first process is not finished, controlling the direct current motor to maintain the first rotating speed;

when the first process is judged to be finished, controlling the direct current motor to be switched to a second rotating speed, and entering a second process;

wherein the first rotational speed is less than the second rotational speed. The output torque of the direct current motor at the first rotating speed is larger than that at the second rotating speed, so that the rotating speed of the direct current motor is matched with the torque required in the opening or running process of the electronic water valve. The range of motion of first valve plate 22 in the first process is contained in first range I, and the range of motion of first valve plate 22 in the second process is contained in second range II.

As shown in fig. 5 and 6, in the first process of the present embodiment, the motor 4 adopts a low-speed starting mode, and is not directly accelerated to the target speed after starting, but is operated at the lower first speed V1. At the moment, the speed is low, so that the output torque of the motor is large, the requirement that the required torque is large due to large friction torque in the first range I can be met, and the stalling risk in the first process is reduced. And accelerating to a higher second speed V2 to operate at the end of the first process, entering a second process, and operating the motor 4 at a higher speed in a motion range (namely a second range II) with a smaller friction torque under the condition of ensuring reliable operation so as to meet the opening, closing or adjusting time of the electronic water valve.

It should be noted here that the first rotation speed V1 and the second rotation speed V2 may be multiple values or may be a variable rotation speed for different system requirements, but it is required that V2 is greater than V1. It should be noted here that at the critical point of the V1 and V2 phase transitions, the velocities of both may be smooth transitions.

Preferably, the first rotation speed V1 meets the range of 100-200 RPM, such as 105RPM, 110RPM, 120RPM, 130RPM, 140RPM, 150RPM, 160RPM, 170RPM, 180RPM, 190RPM, 195RPM, can generate a larger output torque of the motor, meet the torque requirement in the region of larger required torque (i.e. the first range I), and reduce the risk of stalling, and at the same time, the first valve plate does not rotate too slowly, which results in a longer operation time.

The second rotating speed V2 satisfies the range of 250-400 RPM, such as 250RPM, 260RPM, 270RPM, 280RPM, 290RPM, 300RPM, 310RPM, 330RPM, 350RPM, 370RPM, 390RPM, 400RPM, 410RPM, 420RPM, 430RPM, 440RPM, 445RPM, the output torque corresponding to the rotating speed can satisfy the smaller required torque region (i.e. the second range II) with relatively low torque, and the faster rotating speed is favorable for driving the first valve plate to reach the designated position in a shorter time.

In the first embodiment of the control method, whether the first process is finished or not is mainly referred to a current spool rotation angle (θ) currently rotated from the first position toward the second position direction, that is, a first valve plate rotation angle.

Specifically, as shown in fig. 4, the step of judging whether the first process is finished by acquiring the current position of the valve element by the position detection module includes: the method comprises the steps of collecting a current valve core rotation angle (theta) through a position detection module, judging whether the current valve core rotation angle (theta) is larger than or equal to a first valve core preset angle (theta F), if not, judging that a first process is not finished, and if so, judging that the first process is finished.

As shown in fig. 5, θ F is a preset spool rotation angle. The value of θ F is primarily referenced to the torque demand curve of the valve of fig. 1.θ F needs to be larger than the angle θ 1, so that the risk of locked rotation of the first valve plate 22 in the range of the rotation angle 0 to θ 1 (i.e., the first range I) can be reduced. It should be noted that, acquiring the current rotation angle of the valve core is a real-time feedback process, and the time interval of each feedback is generally less than 1ms, which can meet the control accuracy.

Preferably, the preset angle θ F of the first valve element is selected as small as possible under the condition that θ F is larger than θ 1, so that the first valve plate 22 is accelerated in time after running out of the range of 0 to θ 1 (i.e., the first range I), the running time of the first valve plate can be reduced, and the locked rotor risk can be reduced.

Specifically, for the rotary three-way valve in fig. 13, if θ 1 is 0.1 θ 3, the first spool preset angle θ F may be selected to be 0.1 θ 3 to 0.3 θ 3, such as 0.11 θ 3, 0.13 θ 3, 0.15 θ 3, 0.17 θ 3, 0.19 θ 3, 0.20 θ 3, 0.21 θ 3, 0.23 θ 3, 0.25 θ 3, 0.27 θ 3, and 0.29 θ 3, so that a good balance between two requirements of reducing the operation time and reducing the locked rotor risk can be obtained.

The electronic water valve is provided with an electric control component 3, as shown in fig. 2, the electric control component 3 comprises: an information processing module 301 and a motor driving module 302.

The electric control component 3 is connected with the main controller through an automobile bus and receives a bus control signal sent by the main controller. The position detection module is used for acquiring the current valve core position, the information processing module extracts the valve core position information contained in the bus control signal, and the corresponding pulse width modulation sequence is generated by combining the current valve core position information received from the position detection module and is output to the motor driving module; and the motor driving module drives the direct current motor according to the pulse width modulation sequence. The information processing module can be a single chip microcomputer.

The current spool position information may include a current spool rotation angle (θ), and the spool position information included in the bus control signal may include a first spool preset angle (θ F) and/or a second spool preset angle (θ S). In one embodiment of the position detection module 6, the current valve core rotation angle (θ) can be collected by the position detection module 6. For example, the position detection module 6 includes a ring resistor, a brush is disposed on an output gear of the gear set 51, and the brush is in electrical contact with the ring resistor, and the brush rotates on the ring resistor to change a resistance value, so as to obtain a gear rotation angle from the electrical signal, and further obtain a current valve core rotation angle (θ).

In another embodiment of the position detection module 6, the position detection module 6 may include a hall sensor, and the hall sensor includes a hall element and a magnetic element directly or indirectly fixed to the power output portion of the dc motor, and the hall element is capable of interacting with a magnetic pole of the magnetic element to detect the feedback signal. The position sensor adopting the Hall effect has high precision and small volume, and is beneficial to miniaturization and accurate control. Because the direct current motor is in transmission connection with the valve core, the current valve core rotation angle (theta) can be indirectly obtained through the position of the rotor of the direct current motor. For example, according to the number of high levels in the feedback signal, the position information of the rotor of the dc motor can be obtained according to a specific calculation formula, and further the current valve core rotation angle (θ) can be calculated.

Or, the position sensor comprises a light source, a photoelectric element and an optical channel directly or indirectly fixed on the rotor of the direct current motor, and the information processing module calculates current position information of the direct current motor according to a change signal of induced current on the photoelectric element so as to obtain corresponding current valve core position information.

The form of the position sensor 6 includes, but is not limited to, the above position sensor using hall effect and sensor using photoelectric effect, and other sensors may be used to detect the rotation position of the rotor of the dc motor.

The information processing module 301 and the motor driving module 302 are not limited to be disposed in a control box of the electronic water valve, and may be directly integrated with a main controller.

In another embodiment of the electronic control component 3, the electronic control component 3 further includes a data storage module 304, the position detection module 6 is configured to detect a current position of the rotor of the dc motor, and correspondingly, the information processing module 301 may calculate, according to a position detection signal received from the position detection module 6, to obtain position information of the current rotor of the dc motor, and store the position information in the data storage module 304. The data storage module can be an EEPROM or a RAM.

Preferably, the dc motor 4 may be a dc brushless motor (BLDC). The DC brushless motor can obtain better torque and rotating speed characteristics and has longer service life.

The electronic water valve adopting the control method of the electronic water valve comprises a valve body 1, wherein the valve body 1 comprises a shell 11 and a valve seat 12.

In a first embodiment of the valve body 1, as shown in fig. 12, the electronic water valve may be a two-way valve. The housing 1 comprises only a first outlet conduit 113 and one inlet conduit 114. When the first valve plate 22 is located at the first position, the first valve plate 22 fully opens the first flow valve port 121; when the first valve plate 22 is located at the second position, the first valve plate 22 closes the first circulation valve port 121 completely, and seals the first circulation valve port 121.

In a second embodiment of the valve body 1, as shown in fig. 13, the electronic water valve can also be a three-way valve. The housing 11 includes a first outlet line 113, a second outlet line 115, and an inlet line 114, and the valve element is accommodated in the cavity, and the bottom side of the first valve plate 22 contacts the valve seat 12. The valve seat 12 includes a first flow-through valve port 121, a second flow-through valve port 122 in communication with the outlet line 113. First valve plate 22 moves between a first position and a second position relative to valve seat 12. As shown in fig. 14, when the first valve plate 22 is located at the first position, the first valve plate opens the first flow-through valve port 122 and the first outlet pipeline 113, and closes the second flow-through port 212 and the second outlet pipeline 114, and stops conducting, as shown in fig. 16, when the first valve plate 22 is located at the second position, the first valve plate opens the second flow-through valve port 212 and the second outlet pipeline 114, and closes the first flow-through valve port 122 and the first outlet pipeline 113. The state of the valve seat 12 and the first valve plate 22 during operation is shown in fig. 15. When first valve plate 22 is located the first position or the second position, sealed setting between first valve plate and the valve seat. Because the first valve plate is rotated by a certain angle after the valve port is fully closed or fully opened, the sealing area is larger than that of the scheme that the first valve plate stops immediately after the valve port is fully closed or fully opened, and the sealing effect is better. As shown in fig. 7, the required torque varies with the rotation angle of the first valve plate, and when the first valve plate is located at or near the first position or the second position relative to the valve seat, the required torque is greater than when the first valve plate moves between the first position and the second position relative to the valve seat.

In a third embodiment of the valve body 1, as shown in fig. 17, the electronic water valve can be a four-way switching valve. The valve seat 12 has four flow-through ports, namely a first flow-through port 121, a second flow-through port 122, a third flow-through port 123 and a fourth flow-through port 124, and the bottom side of the first valve sheet has a groove. As shown in fig. 17, when the first valve plate 22 is located at the first position, the first through valve port 121 is communicated with the second through valve port 122, and the third through valve port is communicated with the fourth through valve port; when the first valve plate rotates by a certain angle to reach the second position, the first circulation valve port is communicated with the third circulation valve port, and the second circulation valve port is communicated with the fourth circulation valve port.

The first and second positions may be switched depending on whether the valve is opened or closed. Specifically, in the operation process of opening a certain valve port, the first valve plate 22 is in a fully closed state of the certain valve port at the first position, and the first valve plate 22 is in a fully open state of the certain valve port at the second position; in the operation process of closing a certain valve port, the first valve plate 22 is in a state where the certain valve port is fully opened at the first position, and the first valve plate 22 is in a state where the certain valve port is fully closed at the second position. In this embodiment, the "certain valve port" refers to the same valve port, and the "certain valve port" may be the first circulation valve port 121 or the second circulation valve port 122, and so on.

The valve body 1 includes but not limited to two-way, three-way and four-way forms, and can also be other multi-channel valve forms such as five-way and six-way. In addition, the shape of the first valve plate includes, but is not limited to, a sector, and may also be a cylinder or any other valve plate with a flat sealing surface. In addition, the control method of the patent can be used for valves with similar required torque, whether a rotary valve core or a piston valve core.

In a further embodiment of the control method,the control method further comprises the following steps:

acquiring the current position of the valve core through a position detection module to judge whether the second process is finished;

when the second process is not finished, controlling the direct current motor to maintain the second rotating speed;

when the second process is judged to be finished, controlling the direct current motor to be switched to a third rotating speed, and entering a third process;

wherein the third rotational speed is less than the second rotational speed. The control method further includes a third process including controlling the motor rotation speed to a third rotation speed. Wherein the third rotational speed is less than the second rotational speed.

As shown in fig. 7, the movement range of the first valve plate 22 includes a first range I, a second range II, and a third range III. The motor driving torque required by the first valve plate rotation angle between theta 1 and theta 3 (i.e. the second range II in fig. 1) is smaller than the motor driving torque required by the rotation angle between 0 and theta 1 (i.e. the first range I in fig. 1), and the motor driving torque required by the first valve plate rotation angle between theta 1 and theta 2 (i.e. the second range II in fig. 1) is smaller than the motor driving torque required by the rotation angle between theta 2 and theta 3 (i.e. the third range III in fig. 1). If the first position is the state that the valve port is fully opened, when the first valve plate moves from the first position to the third range III, the valve port starts to enter the fully closed state and continues to rotate towards the second position. If the rotating speed of the direct current motor 4 is not changed at this moment, the direct current motor 4 is always operated at a larger target speed, the output torque is insufficient, the blocking risk can be generated, and the water leakage phenomenon caused by the untight sealing between the first valve plate and the valve seat can be further caused.

Specifically, acquiring the current position of the valve element through the position detection module to judge whether the second process is finished comprises the following steps:

the current valve core rotation angle (theta) is collected through the position detection module, whether the current valve core rotation angle (theta) is larger than or equal to a second valve core preset angle (theta S) or not is judged, if not, the second process is judged not to be finished, and if yes, the second process is judged to be finished.

And theta S is a preset angle of the second valve core. It should be noted here that the third rotation speed V3 may have a plurality of values or may be a variable rotation speed for different system requirements, but it is required that V3 is smaller than the second rotation speed V2. It should be noted here that at the critical point of the V2 and V3 phase transitions, the velocities of both may be smooth transitions.

As shown in fig. 9 and 10, the third process is started when the rotation angle of the first valve sheet 22 approaches the third range III. The output torque of the motor is improved by reducing the running speed, so that the stalling risk of the first valve plate 22 in the third range III is reduced, and the first valve plate 22 is ensured to reliably reach the second position and close the valve port. The sealing effect is prevented from being weakened due to the failure of reaching the specified position, and further leakage is reduced.

The preset angle θ S for the second spool may be a plurality of values, mainly referring to the demanded torque curve of the valve in fig. 7. Then θ S must be smaller than θ 2, so that the risk of stalling of the first valve plate 22 in the range of the rotation angle θ 2 to θ 3 (i.e., the third range III) can be reduced.

Preferably, under the condition that the locked-rotor risk is reduced, the second valve element preset angle (theta S) as large as possible is selected, the first valve plate is accelerated in time after approaching the region with large required torque (namely the third range III), the running time of the first valve plate can be reduced, and the locked-rotor risk is reduced.

Specifically, for the rotary three-way valve in fig. 13, if the valve core rotation angle corresponding to the rotation angle θ 2 is 0.9 θ 3, the second valve core preset angle (θ S) may be selected to be 0.7 θ 3 to 0.9 θ 3, for example, 0.71 θ 3, 0.73 θ 3, 0.75 θ 3, 0.77 θ 3, 0.79 θ 3, 0.80 θ 3, 0.301 θ 3, 0.83 θ 3, 0.4 θ 3, 0.87 θ 3, and 0.89 θ 3, so as to achieve a better balance between the two requirements of reducing the operation time and reducing the locked rotor risk.

Preferably, the third rotation speed V3 meets the range of 100-200 RPM, such as 105RPM, 110RPM, 120RPM, 130RPM, 140RPM, 150RPM, 160RPM, 170RPM, 180RPM, 190RPM, 195RPM, can generate a larger output torque of the motor, meet the torque requirement in the region of larger required torque (i.e. the third range III), and reduce the risk of stalling, while not making the first valve plate rotate too slowly to cause the valve closing time to be too long.

Preferably, when the rotation speed of the dc motor is switched from the first rotation speed to the second rotation speed or the second rotation speed to the third rotation speed, the rotation speed switching process is not a sudden speed change, but a speed change process in a time period, preferably a uniform speed change process. Specifically, controlling the dc motor to switch to the third rotational speed includes: the rotating speed of the direct current motor is changed from the rotating speed in the previous process to a third rotating speed in a uniform speed changing manner; controlling the dc motor to switch to the first rotational speed includes: the rotating speed of the direct current motor is changed from the rotating speed in the previous process to a first rotating speed in a uniform speed changing manner; controlling the dc motor to switch to the second rotational speed includes: the rotating speed of the direct current motor is changed from the rotating speed in the previous process to a second rotating speed in a uniformly-changing mode. In one embodiment of the rotation speed switching, as shown in fig. 11, during the switching from the first rotation speed to the second rotation speed, the acceleration process is a uniform acceleration process; and in the process of switching the second rotating speed to the third rotating speed, the deceleration process is a uniform deceleration process. Preferably, the acceleration process takes about 1.2s (as in the segment Δ T1 in fig. 13) and the deceleration process takes less than 100ms (as in the segment Δ T2 in fig. 13), which can reduce stalling. It should be noted that the switching process is started after the previous process is ended, for example, the rotational speed switching process is started after the first process is ended.

Preferably, because the torque of the dc motor is smaller at the second rotation speed, the possibility of stalling the dc motor is increased due to the bounce caused by the counter electromotive force and the speed change, and the rotation speed switching process includes, but is not limited to, a uniform speed changing process, and may also be a non-uniform speed changing process.

In another embodiment of the rotational speed switching process, during the acceleration from the first speed to the second speed, the change of the rotational speed of the dc motor is made gentler as the rotational speed approaches the second rotational speed than the initial change of the acceleration. This arrangement can reduce the chance of stalling. And the speed reduction process is opposite, the rotation speed can be reduced more quickly at the beginning of speed reduction, the change is gentler than the beginning of speed reduction when the rotation speed is close to the third rotation speed, and the influence caused by counter potential and inertia can be overcome.

In another embodiment of the rotational speed switching process, the rotational speed of the dc motor first enters the first gradual change stage, then enters the rapid change stage, and then enters the second gradual change stage, and the acceleration of the first and second gradual change stages is smaller than that of the rapid change stage. Specifically, as shown in fig. 20, the rotation angle (θ) of the first valve plate is a first gradual change stage within θ x to θ y, a rapid change stage within θ y to θ z, and a second gradual change stage within θ z to θ k. This arrangement can further reduce the chance of stalling.

In addition, since some electronic water valves with flow regulation function need to stop the valve core at a specific angle to regulate the opening degree of the valve port, after entering the second process for a certain period of time, the second process may include:

judging whether the valve core reaches a first opening position or not;

if not, controlling the direct current motor to maintain the second rotating speed; and if so, controlling the direct current motor to stop, and finishing the second process. At this time, the first opening position is a valve core position of the required valve port opening, that is, the first valve plate stops at the required valve port opening, and the first valve plate angle is located in the second range II.

In the control method, as shown in fig. 21, the third process may further include:

the current position of the valve core is collected by the position detection module to judge whether the third process is finished or not,

when the third process is not finished, controlling the direct current motor to maintain the third rotating speed;

when the third process is judged to be finished, controlling the direct current motor to stop;

the electronic water valve is closed when the power is cut off.

Specifically, the step of judging whether the third process is finished by acquiring the current position of the valve core through the position detection module comprises the following steps: the current valve core rotation angle (theta) is collected through the position detection module, whether the current valve core rotation angle (theta) is larger than or equal to the maximum rotation angle (theta 3) or not is judged (namely whether the valve core 2 reaches the second position or not is judged), if not, the third process is judged not to be finished, and if yes, the third process is judged to be finished. At this point, the whole valve closing process or the valve opening process is completed.

As shown in fig. 2, the transmission part may include a gear set 51, and the dc motor may be in transmission connection with the valve core through the gear set 51. Other suitable transmission modes can be set between the direct current motor and the valve core, for example, a rotor and the valve core of the direct current motor are set to be in a screw rod structure, or the rotor and the valve core are directly fixed.

The direct current motor 4 can be a permanent magnet brush direct current motor (PMDC), and the control system adopts closed-loop control and carries out feedback through the position detection module 6. Compared with a control component using a brushless direct current motor, the control system is simpler and has lower cost. However, the drawback of this solution is that the PMDC motor adopts the carbon brush to cooperate with the commutator for current commutation, and the control module works in a short time, intermittently and reciprocally, so that the carbon brush often rubs against a specific point or area of the commutator, and an oxide film with high resistivity or a carbon brush dead point is easily generated at a corresponding position of the commutator, thereby causing the PMDC motor to malfunction and reducing the reliability of the electronic water valve.

Therefore, as shown in fig. 19, the dc motor 4 may also be a brushless dc motor (BLDC), the electronic control unit 3 further includes a BLDC motor commutation logic module 309, the commutation logic module generates a corresponding commutation control logic according to a hall position signal fed back by the BLDC motor, and the motor driving module 302 commutates the winding current of the BLDC motor 4 according to the commutation control logic and the PWM sequence generated by the information processing module 301. The information processing module 301 may be a pulse width modulation module. Compared with the electric control component 3 using the permanent magnet brush direct current motor, the defect that a PMDC motor generates carbon brush dead points is overcome, and the service life is longer.

The direct current motor 4 may also be a suitable direct current motor other than the BLDC and PMDC described above. It should be noted that: although the present invention has been described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that the present invention may be modified and equivalents may be substituted for those skilled in the art, and all technical solutions and modifications that do not depart from the spirit and scope of the present invention should be covered by the claims of the present invention.

Claims (11)

1. A control method of an electronic water valve, the electronic water valve at least comprising a valve core and a direct current motor, the electronic water valve being provided with a position detection module, the control method at least comprising:

electrifying to start the electronic water valve;

controlling the valve core to reset to a first position, wherein the first position is positioned at one end of the valve core stroke;

controlling the rotating speed of the direct current motor to be a first rotating speed, and entering a first process;

acquiring the current valve core position through a position detection module, and judging whether the first process is finished;

when the first process is judged not to be finished, controlling the direct current motor to maintain a first rotating speed;

when the first process is judged to be finished, controlling the direct current motor to be switched to a second rotating speed, and entering a second process;

the first rotating speed is less than the second rotating speed, the valve core is a first valve plate, the movement range of the first valve plate in the first process is contained in a first range, the first range is the movement range of the first valve plate with the rotation angle of 0-theta 1, the movement range of the first valve plate in the second process is contained in a second range, the second range is the range of the first valve plate with the rotation angle of theta 1-theta 3, and theta 1 is more than 0 and less than theta 3;

wherein, collecting the current position of the valve core through the position detection module to judge whether the first process is finished comprises:

the current valve core rotation angle (theta) is collected through the position detection module, whether the current valve core rotation angle (theta) is larger than or equal to a first valve core preset angle (theta F) or not is judged, if not, the first process is judged not to be finished, if yes, the first process is judged to be finished, and the theta F is larger than theta 1.

2. The control method of an electronic water valve according to claim 1, wherein the position detection module includes a hall sensor.

3. The control method of the electronic water valve according to claim 1 or 2, further comprising:

acquiring the current position of the valve core through the position detection module to judge whether the second process is finished;

when the second process is not finished, controlling the direct current motor to maintain a second rotating speed;

when the second process is judged to be finished, controlling the direct current motor to be switched to a third rotating speed, and entering a third process;

wherein the third rotational speed is less than the second rotational speed.

4. The control method of the electronic water valve according to claim 3, wherein the judging whether the second process is finished by the position detection module acquiring the current position of the valve element comprises:

acquiring a current valve core rotation angle (theta) through the position detection module, judging whether the current valve core rotation angle (theta) is larger than or equal to a second valve core preset angle (theta S), if not, judging that the second process is not finished, and if so, judging that the second process is finished.

5. The control method of an electronic water valve according to claim 4, further comprising:

whether the third process is finished or not is judged by acquiring the current position of the valve core through the position detection module,

when the third process is not finished, controlling the direct current motor to maintain a third rotating speed;

when the third process is judged to be finished, the valve core is located at the second position, and the direct current motor is controlled to stop;

and closing the electronic water valve when the power is off.

6. The control method of the electronic water valve according to claim 5, wherein the judging whether the third process is finished by the position detection module acquiring the current position of the valve element comprises:

collecting the current valve core rotation angle (theta) through the position detection module, judging whether the current valve core rotation angle (theta) is larger than or equal to the maximum rotation angle (theta 3) or not,

if not, judging that the third process is not finished, and if so, judging that the third process is finished.

7. The control method of an electronic water valve according to claim 4,

controlling the dc motor to switch to a third rotational speed includes: the rotating speed of the direct current motor is changed from the rotating speed in the previous process to a third rotating speed in a uniform speed changing manner;

controlling the dc motor to switch to a first rotational speed includes: the rotating speed of the direct current motor is changed from the rotating speed in the previous process to a first rotating speed in a uniform speed changing manner;

controlling the dc motor to switch to a second rotational speed includes: the rotating speed of the direct current motor is changed from the rotating speed in the previous process to a second rotating speed in a uniform speed changing manner;

the value range of the second rotating speed is 250-400 RPM, the value range of the first rotating speed is 100-200 RPM, and the value range of the third rotating speed is 100-200 RPM.

8. The control method of the electronic water valve according to claim 4, wherein when the rotation speed of the direct current motor is switched between the first rotation speed and the second rotation speed or the second rotation speed and the third rotation speed, the rotation speed of the direct current motor firstly enters a first gradual change stage, then enters a rapid change stage, and then enters a second gradual change stage, and the acceleration of the first gradual change stage and the acceleration of the second gradual change stage are smaller than the acceleration of the rapid change stage;

the value range of the second rotating speed is 250-400 RPM, the value range of the first rotating speed is 100-200 RPM, and the value range of the third rotating speed is 100-200 RPM.

9. The control method of an electronic water valve according to any one of claims 1-2, 4-8,

the electronic water valve has an electrical control component comprising: the information processing module and the motor driving module are connected with the motor; the position detection module is used for acquiring the current valve core position, the information processing module extracts the valve core position information contained in the bus control signal, and generates a corresponding pulse width modulation sequence by combining the current valve core position information received from the position detection module and outputs the pulse width modulation sequence to the motor driving module; and the motor driving module drives the direct current motor according to the pulse width modulation sequence.

10. The control method of the electronic water valve according to claim 9, wherein the position detection module includes a hall sensor including a hall element and a magnetic element directly or indirectly fixed to a power output portion of the dc motor, the hall element being capable of interacting with a magnetic pole of the magnetic element to detect the feedback signal.

11. The control method of an electronic water valve according to claim 3,

the electronic water valve has an electrical control component comprising: the information processing module and the motor driving module are connected with the motor; the position detection module is used for acquiring the current valve core position, the information processing module extracts the valve core position information contained in the bus control signal, and generates a corresponding pulse width modulation sequence by combining the current valve core position information received from the position detection module and outputs the pulse width modulation sequence to the motor driving module; and the motor driving module drives the direct current motor according to the pulse width modulation sequence.

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