WO2016070692A1

WO2016070692A1 - Control method and system for direct-current water pump, water pump assembly and steam cooking appliance

Info

Publication number: WO2016070692A1
Application number: PCT/CN2015/090910
Authority: WO
Inventors: 区毅成; 栾春; 张国君; 刘连程; 唐春玉; 彭涛; 孙宁
Original assignee: 广东美的厨房电器制造有限公司; 美的集团股份有限公司
Priority date: 2014-11-06
Filing date: 2015-09-28
Publication date: 2016-05-12
Also published as: CN105626494A; CN105626494B

Abstract

Disclosed is a control method for a direct-current water pump, comprising: a first control step (102) of controlling an amplification circuit to be activated and initiating control of a timer inside a chip to work when receiving a water delivery instruction; a counting step (104) of counting the number of interrupt signals generated by the timer; and a second control step (106) of controlling the amplification circuit to be deactivated when the number of interrupt signals reaches a first predetermined value, controlling the amplification circuit to be activated when the number of interrupt signals reaches a second predetermined value, and re-performing the counting step (104) and the second control step (106) after clearing the counted number of interrupt signals until receiving an instruction for stopping delivering water. The control method is able to precisely control the water yield of a water pump, and reduce the space occupied by the product and lower product manufacturing costs while continuously delivering water.

Description

DC water pump control method and system, water pump assembly and steam cooking appliance

Technical field

The invention relates to the technical field of water pumps, in particular to a control method of a direct current water pump, a control system of a direct current water pump, a water pump assembly and a steam cooking appliance.

Background technique

With the improvement of living standards, users pay more and more attention to healthy eating, and the requirements for cooking effect are getting higher and higher, and cooking (ie steam heating) is gradually accepted by users due to various advantages.

Cooking relies on the enormous heat released by steam liquefaction to heat the food. Advantages include:

1) cooking speed is fast;

2) Due to the easy diffusion of the gas, the food is heated evenly, thereby avoiding the problem of partial overheating and burning, and the nutritional value is lowered;

3) Since the oxygen concentration in the air is reduced during the steam cooking process, the nutrients that are easily oxidized are prevented from coming into contact with oxygen to reduce the nutritional value;

4) Since the steam itself carries a large amount of heat, the specific heat capacity is higher than that of the air, and the temperature in the closed cavity that regulates only the small exhaust port is relatively time-saving and labor-saving.

At the same time, cooking can keep the moisture in the food so that it is not easy to lose, so the food after cooking is not only high in nutritional value but also fresh in taste.

At present, in the existing steamer cooking equipment, the water pump is usually used to supply water to the steam generator. The water pump used is AC, DC, piston water supply, vortex water supply, and various types of water supply are different. .

However, no matter which type of pump is used, the existing pump control mode only stays on the simple on-off control, only rough flow control can be realized, and the monotonous on-off control will generate the water supply pulse, that is, suddenly to the water demand device (such as Steam generator) provides a larger amount of water, for water heating equipment, This pulsed water supply may cause the temperature inside the water heating device to be unstable, affecting the performance of the product, and also reducing the service life of the product. Moreover, the existing water pump control mode is usually controlled by a relay, and the large size and high cost of the relay restrict the production cost of the product and the volume of the product to some extent. At the same time, since the relay itself needs to be at least 100ms from the switching state to the stability, the control of the pump by the relay cannot achieve accurate continuous water supply control.

Therefore, how to reduce the amount of space occupied by the product and reduce the production cost of the product becomes a technical problem to be solved under the premise of accurately controlling the water output of the water pump and realizing the continuous water supply of the water pump.

Summary of the invention

The present invention is intended to address at least one of the technical problems existing in the related art or related art.

Therefore, the object of the present invention is to provide a DC water pump control method capable of reducing the space occupied by the product and reducing the production cost of the product under the premise of accurately controlling the water output of the water pump and realizing the continuous water supply of the water pump. And control system.

Another object of the present invention is to provide a water pump assembly and a steam cooking appliance.

In order to achieve the above object, according to the embodiment of the first aspect of the present invention, a control method of a DC water pump is proposed. The DC water pump is connected in series with an amplifying circuit and connected between a DC power source and a ground. a diode is connected in parallel at both ends, an anode of the diode is connected to a low potential end of the DC water pump when the amplifying circuit is turned on, and a cathode of the diode is connected to a high potential of the DC water pump when the amplifying circuit is turned on The control method includes: a first control step, when the water supply instruction is received, controlling the amplifying circuit to be turned on, and starting a timer inside the control chip to perform a work; and a statistical step of counting the interrupt generated by the timer a number of signals; a second control step of controlling the amplifying circuit to be turned off when the number of the interrupt signals reaches a first predetermined value, and controlling the amplifying circuit when the number of the interrupt signals reaches a second predetermined value Turning on, and re-executing the statistical step and the second control step after clearing the statistical quantity of the interrupt signal, Stopping water supply to the received instruction; wherein said second predetermined value is greater than or equal to the first predetermined value.

A control method of a direct current water pump according to an embodiment of the present invention, due to a switch shape of an amplifying circuit The switching speed of the state is more sensitive and rapid than that of the mechanical relay. Therefore, in the present application, the switching state of the amplifying circuit is controlled to indirectly control the DC water pump, so that precise control below millisecond level can be realized, and thus the pair can be realized. The precise control of the water output of the pump; at the same time, due to the small volume and low cost of the amplifying circuit, the problem of the large circuit board area occupied by the control of the pump by the relay in the prior art is avoided, and the product is also reduced. Production costs.

In addition, since the rotor or stator inside the DC water pump is wound by a coil, the water pump can be regarded as an inductive load. When the number of interrupt signals generated by the timer inside the control chip reaches a first predetermined value, the control amplification is performed. When the circuit is turned off, since the current in the inductive load does not abruptly change, when the control amplifier circuit is turned on again (that is, when the number of interrupt signals generated by the timer reaches a second predetermined value), the current flowing through the water pump does not occur large. The change, in turn, enables the continuous water supply process to avoid the problem of pulsed water supply caused by monotonous on-off control in the related art.

In addition, the control method of the DC water pump according to the above embodiment of the present invention may further have the following additional technical features:

According to an embodiment of the invention, the timer generates a frequency of the interrupt signal greater than or equal to 100 KHz, and a frequency of a control signal that controls the amplifying circuit to perform an on or off is between 300 Hz and 50 kHz.

According to the DC water pump control method of the embodiment of the present invention, an internal oscillator of 12 MHz can be used and an interrupt signal having a frequency greater than or equal to 100 KHz can be generated by the timing time of the timer. In addition, if the frequency of the control signal that controls the amplifying circuit to perform the opening or closing is small, the current flowing through the water pump may fluctuate greatly, causing the pump to generate a large vibration; if the frequency of the control signal is large, the amplification may be caused. The circuit is frequently turned on and off, affecting the service life of the amplifier circuit, so the preferred frequency of the control signal is between 300 Hz and 50 kHz.

According to an embodiment of the present invention, the method further includes: setting, according to the rated water supply amount and the actual water demand of the DC water pump, a frequency at which the timer generates the interruption signal, the first predetermined value, and the second predetermined value .

According to the control method of the direct current water pump of the embodiment of the present invention, the frequency at which the interrupt signal is generated and the second predetermined value determine the period of the pump control, and the first predetermined value and the frequency at which the interrupt signal is generated The rate determines the time during which the pump is energized in one cycle, so the frequency at which the timer generates the interrupt signal, the first predetermined value and the second predetermined value can be set according to the rated water delivery amount of the DC water pump and the actual water demand.

According to an embodiment of the second aspect of the present invention, a control system for a DC water pump is further provided. The DC water pump is connected in series with an amplifying circuit and connected between a DC power source and a ground. An anode of the diode is connected to a low potential end of the DC water pump when the amplification circuit is turned on, and a cathode of the diode is connected to a high potential end of the DC water pump when the amplification circuit is turned on, the control The system includes: a first control unit, configured to: when receiving the water supply instruction, control the amplification circuit to be turned on, and start a timer inside the control chip to operate; and a statistical unit, configured to collect an interrupt signal generated by the timer The second control unit is configured to control the amplifying circuit to be turned off when the statistical unit counts that the number of the interrupt signals reaches a first predetermined value, and when the number of the interrupt signals reaches a second predetermined value Controlling the amplifying circuit to be turned on; a scheduling unit, configured to count the number of the interrupt signals in the statistical unit When the second predetermined value is used, the statistical quantity of the interrupt signal counted by the statistical unit is cleared, and the statistical unit is scheduled to re-count the number of the interrupt signal, and the second control unit is controlled to re-execute according to the The number of interrupt signals controls the operation of the amplifying circuit until an instruction to stop water delivery is received, wherein the second predetermined value is greater than or equal to the first predetermined value.

According to the control system of the DC water pump according to the embodiment of the present invention, since the switching speed of the switching state of the amplifying circuit is more sensitive and rapid than that of the mechanical relay, the switching state of the amplifying circuit is controlled indirectly in the present application. The pump is controlled to enable precise control below milliseconds, which enables precise control of the water output of the pump. At the same time, due to the small size and low cost of the amplifier circuit, the relay-to-water pump in the prior art is avoided. The problem of large board area occupied by control also reduces the production cost of the product.

In addition, since the rotor or stator inside the DC water pump is wound by a coil, the water pump can be regarded as an inductive load. When the number of interrupt signals generated by the timer inside the control chip reaches a first predetermined value, the control amplification is performed. The circuit is turned off, because the current in the inductive load does not change, so when the amplifier circuit is controlled again (ie, the number of interrupt signals generated by the timer) When the second predetermined value is reached, the current flowing through the water pump does not change greatly, and the continuous water supply process can be realized, thereby avoiding the problem that the pulsed water supply occurs due to the monotonous on-off control in the related art.

In addition, the control system of the DC water pump according to the above embodiment of the present invention may further have the following additional technical features:

According to the DC water pump control system of the embodiment of the present invention, an internal oscillator of 12 MHz can be used and an interrupt signal having a frequency greater than or equal to 100 KHz can be generated by the timing time of the timer. In addition, if the frequency of the control signal that controls the amplifying circuit to perform the opening or closing is small, the current flowing through the water pump may fluctuate greatly, causing the pump to generate a large vibration; if the frequency of the control signal is large, the amplification may be caused. The circuit is frequently turned on and off, affecting the service life of the amplifier circuit, so the preferred frequency of the control signal is between 300 Hz and 50 kHz.

According to an embodiment of the present invention, the method further includes: a setting unit, configured to set, according to the rated water supply amount and the actual water demand of the DC water pump, a frequency at which the timer generates the interrupt signal, the first predetermined value, and a Said second predetermined value.

According to the control system of the DC water pump of the embodiment of the present invention, the frequency of generating the interrupt signal and the second predetermined value determine the period of the pump control, and the first predetermined value and the frequency of generating the interrupt signal determine that the pump is energized in one cycle. The time, therefore, the frequency at which the timer generates the interrupt signal, the first predetermined value and the second predetermined value can be set according to the rated water supply amount of the direct current water pump and the actual water demand.

According to an embodiment of the third aspect of the present invention, a water pump assembly is further provided, comprising: a DC water pump; an amplifying circuit connected in series with the DC water pump and connected between the DC power source and the ground; a diode, and the DC water pump Connected in parallel, an anode of the diode is connected to a low potential end of the DC water pump when the amplifying circuit is turned on, and a cathode of the diode is connected to a high potential end of the DC water pump when the amplifying circuit is turned on; And a control chip, wherein the output end of the control chip is connected to a control end of the amplifying circuit, and the control chip comprises a control system of the DC water pump described in any of the above embodiments.

According to the water pump assembly of the embodiment of the present invention, since the switching speed of the switching state of the amplifying circuit is more sensitive and rapid than that of the mechanical relay, the DC pump is indirectly controlled by controlling the switching state of the amplifying circuit in the present application. It can realize precise control below the millisecond level, and thus can realize precise control of the water output of the pump; at the same time, due to the small volume and low cost of the amplifying circuit, the control of the water pump by the relay in the prior art is avoided. The problem of occupying a large circuit board area also reduces the production cost of the product.

By connecting the diode in parallel with the DC water pump, when the amplifying circuit is suddenly turned off, the DC water pump and the diode form a loop, and thus the current generated by the DC water pump can be discharged.

According to an embodiment of the present invention, the amplifying circuit includes: a triode; an emitter of the triode is grounded, a collector of the triode is connected to a first end of the DC water pump, and a base of the triode passes the first A resistor is coupled to the output of the control chip, a base of the transistor is also coupled to ground through a second resistor, and a second end of the DC water pump is coupled to the DC power source via a third resistor.

Of course, the amplifying circuit can also be a dedicated amplifier or MOS tube or the like.

According to an embodiment of the invention, the direct current water pump is a direct current diaphragm pump.

According to the water pump assembly of the embodiment of the present invention, since the rated speed of the DC diaphragm pump is high and the rated flow rate is large, the above-described control method of the present invention can realize a wide range adjustment of the actual flow rate of the DC diaphragm pump to meet the actual situation. Different needs in the application.

According to an embodiment of the fourth aspect of the present invention, there is also provided a steam cooking appliance comprising: a cooking cavity for containing food; a steam generator for supplying steam to the cooking cavity; and a water tank for Supplying water to the steam generator; and the water pump assembly of any of the above embodiments, wherein a DC water pump in the DC water pump assembly is coupled to the steam generator and the water tank Between, for controlling the amount of water delivered by the water tank to the steam generator.

According to the steam cooking appliance of the embodiment of the present invention, by using the DC water pump described above to control the amount of water supplied from the water tank to the steam generator, the amount of water supplied to the steam generator can be accurately controlled, and a continuous water supply process can be realized. It ensures that the temperature inside the steam generator does not change greatly, and thus the steam can be softened to achieve better cooking results.

The additional aspects and advantages of the invention will be set forth in part in the description which follows.

DRAWINGS

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from

1 shows a schematic flow chart of a control method of a direct current water pump according to an embodiment of the present invention;

2 shows a schematic flow chart of a control system of a direct current water pump according to an embodiment of the present invention;

Figure 3 shows a schematic structural view of a water pump assembly in accordance with an embodiment of the present invention;

4 is a schematic exploded view showing a steam cooking apparatus according to an embodiment of the present invention;

Figure 5 is a schematic view showing the structure of a water tank supplying water to a steam generator according to an embodiment of the present invention;

Figure 6 is a schematic view showing the structure of a water tank supplying water to a steam generator according to another embodiment of the present invention;

Figure 7 is a schematic view showing the structure of a water tank stopping to supply water to a steam generator according to an embodiment of the present invention;

Figure 8 shows a schematic block diagram of a control system for a water pump in accordance with another embodiment of the present invention;

FIG. 9 is a schematic flow chart showing a control method of a water pump according to another embodiment of the present invention; FIG.

Figure 10 shows a timing diagram of the control method shown in Figure 9 in accordance with one embodiment of the present invention;

Figure 11 is a timing chart showing the control method shown in Figure 9 in accordance with another embodiment of the present invention;

FIG. 12 shows a timing chart of the control method shown in FIG. 9 according to still another embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the drawings and specific embodiments. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a full understanding of the invention, but the invention may be practiced otherwise than as described herein. Limitations of the embodiments.

The DC water pump of the present invention is connected in series with the amplifying circuit and connected between the DC power source and the ground. The DC water pump has a diode connected in parallel at both ends thereof, and the anode of the diode is connected to the DC water pump to be turned on in the amplifying circuit. At the low potential end of the time, the cathode of the diode is connected to the high potential end of the DC water pump when the amplifying circuit is turned on.

Fig. 1 shows a schematic flow chart of a control method of a direct current water pump according to an embodiment of the present invention.

As shown in FIG. 1, a control method of a DC water pump according to an embodiment of the present invention includes: Step 102, that is, a first control step, when receiving a water supply instruction, controlling the amplification circuit to be turned on, and starting the control chip inside The timer works; step 104, that is, a statistical step, counting the number of interrupt signals generated by the timer; and step 106, that is, the second control step, when the number of the interrupt signals reaches a first predetermined value, the control station The amplifying circuit is turned off, and when the number of the interrupt signals reaches a second predetermined value, the amplifying circuit is controlled to be turned on, and the statistical step and the second are re-executed after the statistical amount of the interrupt signal is cleared. Controlling the step until an instruction to stop water delivery is received; wherein the second predetermined value is greater than or equal to the first predetermined value.

Since the switching speed of the switching state of the amplifying circuit is more sensitive and rapid than that of the mechanical relay, in the present application, the switching state of the amplifying circuit is controlled to indirectly to the direct current water. The pump is controlled to enable precise control below the millisecond level, thereby enabling precise control of the water output of the pump. At the same time, due to the small size and low cost of the amplifier circuit, the relay-to-water pump in the prior art is avoided. The problem of large board area occupied by control also reduces the production cost of the product.

An internal oscillator of 12 MHz can be used and an interrupt signal having a frequency greater than or equal to 100 kHz can be generated by the timer timing. In addition, if the frequency of the control signal that controls the amplifying circuit to perform the opening or closing is small, the current flowing through the water pump may fluctuate greatly, causing the pump to generate a large vibration; if the frequency of the control signal is large, the amplification may be caused. The circuit is frequently turned on and off, affecting the service life of the amplifier circuit, so the preferred frequency of the control signal is between 300 Hz and 50 kHz.

Specifically, the frequency at which the interrupt signal is generated and the second predetermined value determine the period of the pump control, and the first predetermined value and the frequency at which the interrupt signal is generated determine the time during which the pump is energized in one cycle, and thus may be based on the DC pump The rated water supply amount and the actual water demand amount set a frequency at which the timer generates the interrupt signal, the first predetermined value and the second predetermined value.

2 shows a schematic flow chart of a control system for a direct current water pump in accordance with one embodiment of the present invention.

As shown in FIG. 2, a control system 200 for a DC water pump according to an embodiment of the present invention includes: a first control unit 202, configured to control the amplification circuit to be turned on when a water supply instruction is received, and start the control chip inside The timer unit is configured to: the statistics unit 204 is configured to count the number of interrupt signals generated by the timer; and the second control unit 206 is configured to collect, by the statistics unit 204, the number of the interrupt signals to reach a first predetermined And controlling, when the value is off, the amplifier circuit to be turned off, and controlling the amplifying circuit to be turned on when the number of the interrupt signals reaches a second predetermined value; the scheduling unit 208, for the interrupt counted by the statistics unit 204 When the number of signals reaches the second predetermined value, the statistics of the interrupt signals counted by the statistics unit 204 are cleared, and the statistics unit 204 is scheduled to re-count the number of the interrupt signals, and the control is performed. The second control unit 206 re-executes the operation of controlling the amplifying circuit according to the number of the interrupt signals until receiving an instruction to stop the water supply, wherein The second predetermined value is greater than or equal to the first predetermined value.

Since the switching speed of the switching state of the amplifying circuit is more sensitive and rapid than that of the mechanical relay, the present invention controls the switching state of the amplifying circuit to indirectly control the DC water pump, thereby enabling precise control below milliseconds. In addition, the precise control of the water discharge amount of the water pump can be realized; at the same time, since the volume of the amplifying circuit is small and the cost is low, the problem of the large circuit board area occupied by the control of the water pump by the relay in the prior art is avoided. It also reduces the production cost of the product.

According to an embodiment of the present invention, the method further includes: a setting unit 208, configured to set, according to the rated water supply amount and the actual water demand of the DC water pump, a frequency at which the timer generates the interrupt signal, the first predetermined value, and The second predetermined value.

Figure 3 shows a schematic structural view of a water pump assembly in accordance with an embodiment of the present invention.

As shown in FIG. 3, a water pump assembly according to an embodiment of the present invention includes: a DC water pump 302; an amplifying circuit 304 connected in series with the DC water pump 302 and connected between a DC power source and a ground; a diode 306, and the The DC water pump 302 is connected in parallel, the anode of the diode 306 is connected to the low potential end of the DC water pump 302 when the amplifying circuit 304 is turned on, and the cathode of the diode 306 is connected to the DC water pump 302 at the amplifying circuit. a high potential end when 304 is turned on; and a control chip 308 whose output is connected to the control terminal of the amplifying circuit 304, the control chip 308 including the control system 200 of the DC water pump shown in FIG. .

Since the switching speed of the switching state of the amplifying circuit 304 is more sensitive and rapid than that of the mechanical relay, in the present application, the switching state of the amplifying circuit 304 is controlled to indirectly control the DC water pump 302, so that the millisecond level can be realized. Precise control, which in turn enables precise control of the water output of the pump; at the same time, due to the small size of the amplifying circuit 304, The cost is lower, thus avoiding the problem that the circuit board area occupied by the relay is controlled by the relay in the prior art, and the production cost of the product is also reduced.

In addition, since the rotor or the stator inside the DC water pump 302 is wound by a coil, the water pump can be regarded as an inductive load, and when the number of interrupt signals generated by the timer inside the control chip reaches the first predetermined value, the control is performed. The amplifying circuit 304 is turned off, since the current in the inductive load does not abruptly change, so when the control amplifying circuit 304 is turned on again (that is, when the number of interrupt signals generated by the timer reaches a second predetermined value), the current flowing through the water pump does not occur. Larger changes, in turn, enable continuous water delivery, avoiding the problem of pulsed water supply due to monotonous on-off control in the related art.

By connecting the diode 306 in parallel with the DC water pump 302, when the amplifying circuit 304 is suddenly turned off, the DC water pump 302 and the diode 306 form a loop, and the current generated by the DC water pump 302 can be discharged.

According to an embodiment of the invention, the amplifying circuit 304 comprises: a triode; the emitter of the triode is grounded, the collector of the triode is connected to the first end of the DC water pump 302, and the base of the triode passes The first resistor 310 is connected to the output end of the control chip 308, the base of the triode is also connected to the ground through a second resistor 312, and the second end of the DC water pump 302 is connected to the DC through a third resistor 314. power supply.

Of course, the amplifying circuit 304 can also be a dedicated amplifier or MOS tube or the like.

FIG. 3 is a schematic structural view of a water pump assembly according to an embodiment of the present invention, taking only the amplifying circuit 304 as an NPN type triode as an example. It should be understood by those skilled in the art that the amplifying circuit 304 described in the present application further It may be a PNP type transistor or an amplifying circuit composed of other devices.

According to an embodiment of the invention, the DC water pump 302 is a DC diaphragm pump.

Since the DC diaphragm pump has a high rated speed and a large rated flow rate, the above-described control method of the present invention can realize a wide range adjustment of the actual flow rate of the DC diaphragm pump to meet different needs in practical applications.

The present invention also provides a steam cooking appliance comprising: a cooking cavity for containing food; a steam generator for supplying steam to the cooking cavity; and a water tank for supplying water to the steam generator; And the water pump assembly shown in Figure 3, the direct current water in the DC water pump assembly A pump is coupled between the steam generator and the water tank for controlling the amount of water delivered by the water tank to the steam generator.

By using the DC water pump described above to control the water supply amount of the water tank to the steam generator, the water supply amount to the steam generator can be accurately controlled, and the continuous water supply process can be realized to ensure that the temperature in the steam generator does not occur greatly. The change, in turn, ensures that the steam is softened to achieve a better cooking effect.

Specifically, a schematic structural view of a steam cooking appliance according to an embodiment of the present invention will be described in detail below with reference to FIGS. 4 to 7.

As shown in FIGS. 4 to 7, a steam cooking device according to an embodiment of the present invention includes:

The cooking cavity 01, the steam injection hole 01a and the cavity bottom boss 01b disposed in the cooking cavity 01, the door body 02, the main control circuit board 03, the bottom plate 04 disposed in the cooking cavity 01, and the outer cover right Arm 05, housing left arm 06, door switch state detecting bracket 07, steam generator 08, steam generator heating tube 08a, steam generator temperature sensor 08b, steam generator nozzle 08c, water pump 10, each water pump 10 is a steam Generator 08 water supply, water pump bracket 11, top control panel 12, back heat sink 13, electromagnetic water distribution valve 14, water tank in place detection device 15, inlet water tank bracket shell 16, inlet water tank 17, cooling fan 18, decorative back panel 19. Internal conductor 20, power cord 21, steam exhaust port 22.

As shown in FIG. 5, a water pump 10 is connected between the inlet water tank 17 and the steam generator 08, and the water outlet 17a of the inlet water tank 17 communicates with the water inlet 10a of the water pump 10, and the water outlet 10b of the water pump 10 and the steam generator The water inlet of 08 is connected. 10c is the water storage chamber of the

water pump

10, 10d is the water pump movable diaphragm, 10e is the motor of the

water pump

10, 10f is the rotor core (brush motor) of the

water pump

10, and 10g is the rotor coil (brush motor) of the water pump 10.

Of course, an electromagnetic water distribution valve 14 may be connected between the water inlet tank 17 and the water pump 10. As shown in FIG. 6, when the electromagnetic water distribution valve 14 is energized, the electromagnetic water distribution valve 14 communicates with the water outlet of the water inlet tank 17. 17a is connected to the water inlet 10a of the water pump 10, the water outlet 10b of the water pump 10 is connected to the steam generator 08, and the water inlet tank 17 supplies water to the steam generator 08; as shown in Fig. 7, when the electromagnetic water distribution valve 14 is powered off, the electromagnetic The water dividing valve 14 disconnects the water outlet 17a of the inlet water tank 17 from the water inlet 10a of the water pump 10, and the inlet water tank 17 stops supplying water to the steam generator 08.

Figure 8 shows a schematic block of a control system for a water pump in accordance with another embodiment of the present invention. Figure.

As shown in FIG. 8, a control system for a water pump according to another embodiment of the present invention includes a control chip 802, an amplification circuit 804 connected to the control chip 802, and a water pump 806 connected to the amplification circuit 804.

The control chip 802 can be a single chip microcomputer, and includes: an arithmetic unit 8024 (CPU), a timer 8022 that periodically sends an interrupt signal to the arithmetic unit 8024, a storage unit 8026 that stores the number of interrupt signals, and an output port 8028 of the control signal. The water pump 806 can be a DC diaphragm pump.

Further, the voltage variation frequency outputted by the output port 8028 of the control chip 802 should be between 300 Hz and 50 kHz. If the frequency is selected too low, the current in the pump will have sufficient time to fluctuate up and down, resulting in a larger pump. If the frequency selection is too high, the switch (such as a triode) in the amplifying circuit 804 will be operated too frequently, resulting in a significant decrease in the life of the switch due to excessive loss.

The timer 8022 inside the control chip 802 generates an interrupt signal with a higher frequency than the output voltage of the output port 8028, which is generally above 100 kHz. Usually, an internal oscillator of 12 MHz is used and generated by counting the timer 8028. This periodic interrupt signal is above 100 kHz. The interrupt signal may be in the form of a low level, a high level, or an upper falling edge, and may be specifically set according to the identification manner of the arithmetic unit 8024 of the control chip 802.

The processing flow chart of the water pump control system shown in Fig. 8 will be described in detail below with reference to Fig. 9.

As shown in FIG. 9, a control method of a water pump according to another embodiment of the present invention includes:

In step 902, the water pump is powered, and the timer of the control chip starts counting.

In step 904, the timer of the control chip periodically sends an interrupt signal to the chip CPU (ie, the arithmetic unit).

In step 906, the chip CPU determines whether the number of interrupt signals exceeds the specified high level execution number. If yes, step 908 is performed; otherwise, returns to step 904. In this embodiment, when the control chip outputs a high level, the power supply of the pump is turned off as an example for explanation.

In step 908, when the chip CPU determines that the number of interrupt signals exceeds the specified high level execution number, the water pump is powered off, and the timer of the control chip continues to count.

Step 910, the chip CPU determines whether the number of interrupt signals exceeds the number of cycles. If yes, go to step 912; otherwise, go back to step 908.

Step 912, when the chip CPU determines that the number of interrupt signals exceeds the number of one cycle, the chip CPU counts back to zero, and re-counts the interrupt signal sent by the timer.

At step 914, it is determined whether the operation needs to be ended, and if so, the process ends; otherwise, the process returns to step 902.

10 to 12 show timing charts for controlling the water pump according to the number of different interrupt signals.

As shown in FIG. 10, waveform 1002 is a schematic diagram of an interrupt signal (low level trigger) of the timer; waveform 1004 shows a waveform diagram of the output of the control chip; waveform 1006 shows a current diagram of the flow through the water pump; waveform 1008 shows A schematic diagram of the water supply rate of the pump.

It can be seen that the control chip turns off the water pump power supply loop when the count value of the interrupt signal reaches 2, and the period is 6 interrupt signal counts. Practically speaking, if the period in which the timer generates an interrupt is 50 microseconds, the pulse width generated by the method shown in FIG. 10 is 100 microseconds, the period is 300 microseconds, and the equivalent control current generated at the pump end is about It is 1/3 of the rated current, and the continuous water supply flow rate is about 1/9 of the rated water supply flow rate.

As shown in FIG. 11, waveform 1102 is a schematic diagram of an interrupt signal (low level trigger) of the timer; waveform 1104 shows a waveform diagram of the output of the control chip; waveform 1106 shows a current diagram of the flow through the water pump; waveform 1108 shows A schematic diagram of the water supply rate of the pump.

It can be seen that the control chip turns off the water pump power supply loop when the count value of the interrupt signal reaches 1, and the period is 6 interrupt signal counts. In fact, if the period in which the timer generates an interrupt is 50 microseconds, the pulse width generated by the method shown in FIG. 11 is 50 microseconds, the period is 300 microseconds, and the equivalent control current generated at the pump end is about It is 1/6 of the rated current, and the continuous water supply flow rate is about 1/36 of the rated water supply flow rate.

As shown in FIG. 12, waveform 1202 is a schematic diagram of an interrupt signal (low level trigger) of the timer; waveform 1204 shows a waveform diagram of the output of the control chip; waveform 1206 shows a current diagram of the flow through the water pump; waveform 1208 shows A schematic diagram of the water supply rate of the pump.

It can be seen that the control chip turns off the water pump power supply loop when the count value of the interrupt signal reaches 2, and the period is 4 interrupt signal counts. Practically speaking, if the period in which the timer generates an interrupt is 50 microseconds, the pulse width generated by the method shown in FIG. 12 is 100 microseconds, and the period is 200 microseconds, the equivalent control current generated at the pump end is about 1/2 of the rated current, and the continuous water supply flow rate is about 1/4 of the rated water supply flow rate.

In summary, the water supply flow rate of the water pump (especially the DC diaphragm pump) is proportional to the square of the supply current, and the proportional coefficient depends on the actual parameters of the water supply pump itself.

Obviously, it can be realized according to the actual water demand requirement to adjust the number of counts of the interrupt signal of the control chip to turn off the power supply circuit of the water pump or the number of interrupt signals of one cycle.

Through the above technical solutions, it is possible to control the continuous water supply of the water pump, thereby enhancing the service life of the product; and the circuit is simple, and the motor current is adjusted by software, and no special equipment (such as a pulse width modulation PWM signal generating device) is required, and the cost is low; The water supply adjustment range is large, and the technical application surface is quite wide. In addition, the volume of each water storage chamber (usually more than three) in the DC diaphragm pump is small, and the water supply switching in different animal water chambers is quite smooth. Therefore, there is no obvious problem of pulsed water supply like a peristaltic pump.

The technical solution of the present invention is described in detail above with reference to the accompanying drawings. Considering that the existing water pump control mode only stays on the simple on-off control, only rough flow control can be realized, and the monotonous on-off control generates a water supply pulse. Moreover, the existing water pump control mode is usually controlled by a relay, and the large size and high cost of the relay restrict the production cost of the product and the volume of the product to some extent. At the same time, since the relay itself needs to be at least 100ms from the switching state to the stability, the control of the pump by the relay cannot achieve accurate on-off water control. Therefore, the present invention proposes a new DC water pump control scheme, which can reduce the space occupied by the product and reduce the production cost of the product under the premise of accurately controlling the water output of the water pump and realizing the continuous water supply of the water pump. .

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

The method for controlling a DC water pump is characterized in that: the DC water pump and the amplifying circuit are connected in series and connected between the DC power source and the ground, and the diode of the DC water pump is connected in parallel with a diode, and the anode of the diode is connected to the The low-potential end of the DC water pump when the amplifying circuit is turned on, the cathode of the diode is connected to the high-potential end of the DC water pump when the amplifying circuit is turned on, and the control method includes:

a first control step of controlling the amplifying circuit to be turned on when receiving the water supply instruction, and starting a timer inside the control chip to operate;

a statistical step of counting the number of interrupt signals generated by the timer;

a second control step of controlling the amplifying circuit to be turned off when the number of the interrupt signals reaches a first predetermined value, and controlling the amplifying circuit to be turned on when the number of the interrupt signals reaches a second predetermined value Re-executing the statistical step and the second control step after clearing the statistical quantity of the interrupt signal until receiving an instruction to stop water delivery;

Wherein the second predetermined value is greater than or equal to the first predetermined value.
A method of controlling a direct current water pump according to claim 1, wherein

The timer generates a frequency at which the interrupt signal is greater than or equal to 100 kHz, and a frequency of a control signal that controls the amplifying circuit to perform an on or off is between 300 Hz and 50 kHz.
The method of controlling a DC water pump according to claim 2, further comprising:

And setting a frequency, the first predetermined value, and the second predetermined value of the interrupt signal by the timer according to a rated water supply amount and an actual water demand amount of the DC water pump.
A DC water pump control system is characterized in that: the DC water pump and the amplifying circuit are connected in series and connected between the DC power source and the ground, the DC water pump has a diode connected in parallel at both ends thereof, and the anode of the diode is connected to the The low-potential end of the DC water pump when the amplifying circuit is turned on, the cathode of the diode is connected to the high-potential end of the DC water pump when the amplifying circuit is turned on, and the control system includes:

a first control unit, configured to control the amplifying circuit to be turned on when receiving the water supply instruction, and start a timer inside the control chip to operate;

a statistical unit, configured to count the number of interrupt signals generated by the timer;

a second control unit, configured to: when the statistics unit counts that the number of the interrupt signals reaches a first predetermined value, control the amplifying circuit to be turned off, and when the number of the interrupt signals reaches a second predetermined value, control The amplifying circuit is turned on;

a scheduling unit, configured to: when the number of the interrupt signals counted by the statistical unit reaches the second predetermined value, clear a statistical quantity of the interrupt signal that is counted by the statistical unit, and schedule the statistical unit Re-stating the number of the interrupt signals, and controlling the second control unit to re-execute the operation of controlling the amplifying circuit according to the number of the interrupt signals until receiving an instruction to stop water supply, wherein the second predetermined value Greater than or equal to the first predetermined value.
A control system for a direct current water pump according to claim 4, wherein

The timer generates a frequency at which the interrupt signal is greater than or equal to 100 kHz, and a frequency of a control signal that controls the amplifying circuit to perform an on or off is between 300 Hz and 50 kHz.
The control system of the DC water pump according to claim 5, further comprising:

And a setting unit, configured to set, according to the rated water supply amount and the actual water demand of the DC water pump, a frequency at which the timer generates the interrupt signal, the first predetermined value, and the second predetermined value.
A water pump assembly characterized by comprising:

DC water pump;

An amplifying circuit is connected in series with the DC water pump and connected between the DC power source and the ground;

a diode connected in parallel with the DC water pump, an anode of the diode is connected to a low potential end of the DC water pump when the amplification circuit is turned on, and a cathode of the diode is connected to the DC water pump to be turned on in the amplification circuit High potential end;

A control chip, an output of which is connected to a control terminal of the amplifying circuit, the control chip comprising a control system of the direct current water pump according to any one of claims 4 to 6.
The water pump assembly according to claim 7, wherein said amplifying circuit comprises: a triode;

An emitter of the triode is grounded, a collector of the triode is connected to a first end of the DC water pump, and a base of the triode is connected to an output of the control chip through a first resistor The base of the triode is also connected to the ground through a second resistor, and the second end of the DC water pump is connected to the DC power source through a third resistor.
A water pump assembly according to claim 7 or 8, wherein said DC water pump is a DC diaphragm pump.
A steam cooking appliance, comprising:

Cooking cavity for holding food;

a steam generator for supplying steam to the cooking cavity;

a water tank for supplying water to the steam generator;

A water pump assembly according to any one of claims 7 to 9, wherein a direct current water pump in the direct current water pump assembly is connected between the steam generator and the water tank for controlling the water tank to generate the steam The amount of water delivered by the device.