Low-power-consumption electromagnetic valve driving circuit and electromagnetic pilot valve

Abstract

The utility model provides a low-power-consumption electromagnetic valve drive circuit and an electromagnetic pilot valve. The low-power-consumption electromagnetic valve drive circuit comprises a power supply unit and a drive unit. The driving unit comprises a timing circuit and a current-limiting resistor; when the timing time of the timing circuit is not up, the power supply unit directly supplies power to the electromagnetic valve, and large-current starting of the electromagnetic valve is achieved. After the timing circuit reaches the timing time, the current output by the power supply unit supplies power to the electromagnetic valve through the current limiting resistor, low-power-consumption keeping of the electromagnetic valve is achieved, an external control unit is not needed, low-power-consumption control can be automatically completed after the circuit is powered on, circuit complexity is reduced, the circuit is not prone to being influenced by temperature changes, and the service life of the electromagnetic valve is prolonged. And the control accuracy of the electromagnetic valve is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to solenoid valve drive technical field especially relates to a low -power solenoid valve drive circuit and electromagnetic pilot valve. BACKGROUND

[0002] Solenoid valve is the electric control commonly used electric control switch on-off device, and the use range is very extensive. When the solenoid valve is powered, the electromagnetic force generated by the solenoid can make the solenoid valve in the electromagnetic head attract, thereby making the solenoid valve conductive. After power off, the electromagnetic force disappears, and the electromagnetic head is not attracted, so that the solenoid valve is closed. Before the solenoid valve is connected, the distance between the electromagnetic heads is far apart, and a large current is usually required to generate a large electromagnetic force. However, after the solenoid valve is turned on, if the on-current of the solenoid valve is used to maintain the attraction between the electromagnetic heads, the power consumption of the solenoid valve will be greatly increased, and long-term operation will cause the solenoid valve to overheat and shorten the service life. After the solenoid valve is turned on, a smaller current is used to maintain the attraction between the electromagnetic heads, which greatly reduces the driving power consumption while maintaining the on-state of the solenoid valve. In the related art, the low-power solenoid valve drive circuit uses an external control unit, and the external control unit uses a voltage comparator to realize low-power control of the solenoid valve driving current. However, the voltage comparator changes the timing time by adjusting the reference voltage, which increases the complexity of the circuit, and the voltage comparator is affected by temperature changes, which may cause the timing error to increase, affecting the performance of the solenoid valve. SUMMARY

[0003] The utility model provides a low -power solenoid valve drive circuit and electromagnetic pilot valve to solve the defect that the traditional low -power solenoid valve drive circuit uses external control unit and uses voltage comparator to realize low -power control of solenoid valve driving current, which increases the complexity of the circuit, and the voltage comparator is affected by temperature changes, which may cause the timing error to increase, affecting the performance of the solenoid valve.

[0004] The utility model provides a low -power solenoid valve drive circuit, which comprises:

[0005] A power supply unit and a driving unit are provided.

[0006] The driving unit comprises a timing circuit and a current limiting resistor. When the timing time has not arrived, the power supply unit directly supplies power to the solenoid valve to realize large current starting of the solenoid valve. When the timing time arrives, the current output by the power supply unit passes through the current limiting resistor to supply power to the solenoid valve, realizing low-power maintenance of the solenoid valve.

[0007] The low-power solenoid valve drive circuit according to the utility model further comprises a freewheeling protection unit.

[0008] The freewheeling protection unit comprises a diode, an anode of the diode is connected to one end of the electromagnetic valve, and a cathode of the diode is connected to the other end of the electromagnetic valve.

[0009] When the electromagnetic valve is powered on, the power supply unit supplies power to the electromagnetic valve through the driving unit, a magnetic field is generated in the electromagnetic coil of the electromagnetic valve, and the electromagnetic head is attracted;

[0010] When the electromagnetic valve is powered off, the magnetic field in the electromagnetic coil rapidly decays to generate a reverse electromotive force, the anode voltage of the diode is higher than the cathode voltage, the diode is turned on, and a loop is formed to release the reverse electromotive force in the electromagnetic coil through the diode.

[0011] The low-power electromagnetic valve driving circuit provided by the utility model further comprises an anti-reverse unit, the anti-reverse unit comprises four diodes D1, D2, D3 and D4, which are connected between the two ports of the power supply unit, and the diodes D1, D2, D3 and D4 form a bridge rectifier circuit.

[0012] The low-power electromagnetic valve driving circuit provided by the utility model further comprises a timing circuit.

[0013] A first resistor and a first capacitor are connected in series.

[0014] The timing time is determined according to a time constant calculated by the first resistor and the first capacitor, and the time constant tau represents the time required for the capacitor to charge and discharge to a final value.

[0015] The time constant tau is RxC.

[0016] Wherein R is the resistance value of the resistor, and C is the capacity of the capacitor.

[0017] The low-power electromagnetic valve driving circuit provided by the utility model further comprises a MOS tube in the driving unit.

[0018] The MOS tube is used for controlling the current output path of the power supply unit.

[0019] The low-power electromagnetic valve driving circuit provided by the utility model further comprises an inverter in the driving unit.

[0020] The input port of the inverter is connected with the timing circuit.

[0021] When the voltage across the first capacitor is less than the preset threshold, the output of the inverter is high; when the voltage across the first capacitor is greater than the preset threshold, the output of the inverter is low.

[0022] When the inverter outputs high level, the MOS tube is turned on, and the power supply unit directly supplies power to the electromagnetic valve;

[0023] When the inverter outputs low level, the MOS tube is closed, and the power supply unit supplies power to the electromagnetic valve through the current limiting resistor, thereby realizing low power consumption maintenance of the electromagnetic valve.

[0024] According to the low-power-consumption electromagnetic valve driving circuit provided by the utility model, the driving unit further comprises a second resistor;

[0025] The second resistor is connected in series between the power supply unit and the electromagnetic valve, and limits the current passing through the electromagnetic valve through the resistance value.

[0026] According to the low-power-consumption electromagnetic valve driving circuit provided by the utility model, the driving unit further comprises an inductor;

[0027] The inductor is used for filtering and smoothing current.

[0028] The utility model further provides an electromagnetic pilot valve, which comprises the low-power-consumption electromagnetic valve driving circuit as described above.

[0029] The low-power-consumption electromagnetic valve driving circuit and the electromagnetic pilot valve provided by the utility model, the low-power-consumption electromagnetic valve driving circuit comprises a power supply unit and a driving unit; the driving unit comprises a timing circuit and a current limiting resistor; when the timing time has not arrived, the power supply unit directly supplies power to the electromagnetic valve, thereby realizing large-current starting of the electromagnetic valve; after the timing time arrives, the current output by the power supply unit supplies power to the electromagnetic valve through the current limiting resistor, thereby realizing low-power-consumption maintenance of the electromagnetic valve, without the need of an external control unit, low-power-consumption control can be automatically completed after the circuit is powered on, circuit complexity is reduced, and the accuracy of electromagnetic valve control is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical scheme in the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0031] Figure 1 It is the structure schematic view of the low-power-consumption electromagnetic valve driving circuit provided by the utility model embodiment;

[0032] Figure 2 It is the circuit diagram of the low-power-consumption electromagnetic valve driving circuit provided by the utility model embodiment. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the utility model clearer, the technical scheme in the utility model will be described clearly and completely in combination with the drawings in the utility model below. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without creative labor belong to the protection scope of the utility model.

[0034] Figure 1 The low-power electromagnetic valve driving circuit provided by the utility model embodiment has a structure diagram, and the low-power electromagnetic valve driving circuit comprises:

[0035] A power supply unit and a driving unit;

[0036] The driving unit comprises a timing circuit and a current limiting resistor; when the timing time has not arrived, the power supply unit directly supplies power to the electromagnetic valve, realizing large-current starting of the electromagnetic valve; after the timing time arrives, the current output by the power supply unit supplies power to the electromagnetic valve through the current limiting resistor, realizing low-power maintaining of the electromagnetic valve.

[0037] The traditional low-power electromagnetic valve driving circuit uses an external control unit, and the external control unit realizes low-power control of electromagnetic valve driving current by using a voltage comparator. However, the voltage comparator changes the timing time by adjusting the reference voltage, and the adjustment of the reference voltage increases the circuit complexity, and the voltage comparator is affected by temperature change, which may cause the timing error to increase, and affects the performance of the electromagnetic valve.

[0038] The low-power electromagnetic valve driving circuit provided by the utility model embodiment comprises a power supply unit and a driving unit; the driving unit comprises a timing circuit and a current limiting resistor; when the timing time has not arrived, the power supply unit directly supplies power to the electromagnetic valve, realizing large-current starting of the electromagnetic valve; after the timing time arrives, the current output by the power supply unit supplies power to the electromagnetic valve through the current limiting resistor, realizing low-power maintaining of the electromagnetic valve, without an external control unit, and the circuit can automatically complete low-power control after power-on, reduces the circuit complexity, is not easily affected by temperature change, and improves the accuracy of electromagnetic valve control.

[0039] Based on any one of the above embodiments, the power supply unit refers to a unit that can provide energy, and is connected to Figure 2The anti-reverse unit is composed of four diodes D1, D2, D3 and D4, and realizes non-polarity input of the power supply; the driving unit is composed of resistors R1 and R2, a MOS tube Q1, an inverter U1 and a capacitor C1; wherein R2 and C1 form a timing circuit (the timing time is determined by the values of R2 and C1), when the timing time has not arrived, the inverting terminal 14 of the inverter U1 outputs a high level to the gate of the N-type MOS tube Q1, the Q1 is turned on, the power supply directly supplies power to the electromagnetic valve L1, electromagnetic valve large current starting is realized, and the electromagnetic head is attracted; after the timing time arrives, the inverting terminal 14 of the inverter U1 outputs a low level to the gate of the N-type MOS tube Q1, the Q1 is turned off, at this moment, the power supply supplies power to the electromagnetic valve through the current limiting resistor R1, and electromagnetic valve low power consumption maintaining is realized.

[0040] In the embodiment of the utility model, the low-power electromagnetic valve driving circuit further comprises:

[0041] The freewheeling protection unit comprises a diode, an anode of the diode is connected to one end of the electromagnetic valve, and a cathode of the diode is connected to the other end of the electromagnetic valve.

[0042] When the electromagnetic valve is powered on, the power supply unit supplies power to the electromagnetic valve through the driving unit, a magnetic field is generated in the electromagnetic coil in the electromagnetic valve, and the electromagnetic head is attracted; when the electromagnetic valve is powered off, the magnetic field in the electromagnetic coil rapidly decays, an inverse electromotive force is generated, the anode voltage of the diode is higher than the cathode voltage, the diode is turned on, a loop is formed, and the inverse electromotive force in the electromagnetic coil is released through the diode.

[0043] In the embodiment of the utility model, when the electromagnetic valve is suddenly powered off, a reverse electromotive force (i.e. a reverse voltage) is generated in the coil inside the electromagnetic valve, because the magnetic field in the coil attempts to maintain the original current in the process of disappearing, thereby generating a voltage with a reverse direction at both ends of the coil. If no measures are taken to deal with the reverse electromotive force, other elements in the circuit may be damaged, and even the electromagnetic valve itself may be damaged.

[0044] In order to prevent this situation from happening, the freewheeling protection unit is connected in parallel to the electromagnetic valve through a diode D5. When the electromagnetic valve is powered off, the diode allows the current to continue to flow in a safe path until the energy stored in the electromagnetic valve coil is completely released. In this way, not only are other elements in the circuit protected from the influence of the reverse electromotive force, but also the electromagnetic valve is protected from possible damage caused by the reverse voltage.

[0045] The low-power electromagnetic valve driving circuit provided by the embodiment of the utility model further comprises:

[0046] The anti-reverse unit comprises four diodes D1, D2, D3 and D4, which are connected between two ports of the power supply unit, and the diodes D1, D2, D3 and D4 form a bridge rectifier circuit.

[0047] In the embodiment of the utility model, the anti-reverse unit ensures that the power supply can be inputted without polarity, that is, no matter how the positive and negative poles of the power supply are connected to the circuit, the circuit can work normally and will not be damaged or unable to work due to the reverse connection of the power supply. In the low-power electromagnetic valve driving circuit described in the document, the anti-reverse unit is composed of four diodes (D1, D2, D3 and D4), and the four diodes form a bridge rectifier circuit structure. This structure can convert the input power supply into a single direction current, thereby ensuring that even if the power supply wiring is wrong, it will not affect the normal operation of the circuit, improving the reliability and safety of the circuit.

[0048] In the embodiment of the utility model, the timing circuit comprises:

[0049] The first resistor and the first capacitor are connected in series.

[0050] The timing time is determined according to a time constant calculated by the first resistor and the first capacitor, and the time constant τ represents the time required for the capacitor to charge and discharge to the final value;

[0051] The time constant τ=RxC.

[0052] Wherein R is the resistance value of the resistor, and C is the capacity of the capacitor.

[0053] In the embodiment of the utility model, the driving unit further comprises:

[0054] The MOS tube is used for controlling the current output path of the power supply unit.

[0055] In the embodiment of the utility model, the main function of the MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor, Metal-Oxide-Semiconductor Field-Effect Transistor) is to act as a switch for controlling the start and low-power holding state of the electromagnetic valve. The functions of the MOS tube Q1 in this circuit include:

[0056] (1) Large current start: when the circuit is just connected to the power supply, the timing circuit (composed of R2 and C1) has not completed charging, at this time the output of the inverter U1 is high level, making the MOS tube Q1 conductive. In this way, the power supply can directly supply power to the electromagnetic valve L1, providing a large starting current to make the electromagnetic valve quickly enter the electromagnetic head attraction state.

[0057] (2) Low power consumption is kept: after the charging of the timing circuit is completed, the output of the inverter U1 becomes low after the preset time, causing the MOS tube Q1 to close. At this time, the power supply supplies power to the electromagnetic valve through the current limiting resistor R1, providing a much smaller holding current to maintain the attraction state of the electromagnetic valve, while greatly reducing the power consumption.

[0058] In this way, the MOS tube Q1 not only helps to achieve the large current start of the electromagnetic valve, but also effectively reduces the power consumption of the electromagnetic valve in the holding attraction state, prolonging the service life of the electromagnetic valve.

[0059] In the embodiment of the utility model, the driving unit further includes:

[0060] The input port of the inverter is connected with the timing circuit;

[0061] When the voltage across the first capacitor is less than the preset threshold, the output of the inverter is high; when the voltage across the first capacitor is greater than the preset threshold, the output of the inverter is low;

[0062] When the inverter output is high, the MOS tube is turned on, and the power supply unit directly supplies power to the electromagnetic valve;

[0063] When the inverter output is low, the MOS tube is closed, and the power supply unit supplies power to the electromagnetic valve through the current limiting resistor, realizing low power consumption of the electromagnetic valve.

[0064] In the embodiment of the utility model, the inverter is added to avoid oscillation caused by the electromagnetic valve malfunction, and the circuit anti-reverse connection scheme is provided

[0065] In the embodiment of the utility model, the driving unit further includes:

[0066] The second resistor is connected in series between the power supply unit and the electromagnetic valve, and the current passing through the electromagnetic valve is limited by the resistance value.

[0067] Inductance; the inductance is used for filtering and smoothing current.

[0068] The low-power electromagnetic valve driving circuit provided by the embodiment of the utility model can be applied to the field of coal mines or other engineering machinery fields using electromagnetic valves, such as electromagnetic valve driving in fully mechanized working face in the field of coal mines.

[0069] The low-power electromagnetic valve driving circuit provided by the utility model can realize automatic realization of low-power electromagnetic valve driving circuit without external control unit, can realize power polarity-free input, can realize automatic realization of low-power electromagnetic valve driving circuit without external control unit, and can realize power polarity-free input through the anti-reverse connection circuit.

[0070] The utility model embodiment further provides an electromagnetic pilot valve, including low power consumption electromagnetic valve drive circuit as above described embodiment.

[0071] The device embodiments described above are only illustrative, wherein the units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, i.e., can be located in one place or can be distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0072] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. A low-power solenoid valve drive circuit, characterized by comprising: Comprising: a power supply unit and a driving unit; the driving unit comprises a timing circuit and a current limiting resistor; when the timing time has not arrived, the power supply unit directly supplies power to the electromagnetic valve to realize large current starting of the electromagnetic valve; when the timing time arrives, the current output by the power supply unit passes through the current limiting resistor to supply power to the electromagnetic valve to realize low power consumption maintaining of the electromagnetic valve; a reverse prevention unit, the reverse prevention unit comprises four diodes D1, D2, D3 and D4, which are connected between the two ports of the power supply unit respectively, and the diodes D1, D2, D3 and D4 form a bridge rectifier circuit.

2. The low-power solenoid valve drive circuit according to claim 1, characterized by Further comprising a freewheeling protection unit; the freewheeling protection unit comprises a diode, the anode of the diode is connected to one end of the electromagnetic valve, and the cathode of the diode is connected to the other end of the electromagnetic valve; when the electromagnetic valve is powered on, the power supply unit supplies power to the electromagnetic valve through the driving unit, and the electromagnetic coil in the electromagnetic valve generates a magnetic field to make the electromagnetic head attract; when the electromagnetic valve is powered off, the magnetic field in the electromagnetic coil decays rapidly to generate a reverse electromotive force, the anode voltage of the diode is higher than the cathode voltage, the diode is turned on, and a loop is formed to release the reverse electromotive force in the electromagnetic coil through the diode.

3. The low-power solenoid valve drive circuit according to claim 1, characterized by The timing circuit comprises: a first resistor and a first capacitor, which are connected in series.

4. The low-power solenoid valve drive circuit according to claim 3, characterized by The timing time is determined according to the time constant calculated by the first resistor and the first capacitor, and the time constant τ represents the time required for the capacitor to charge and discharge to the final value; The time constant τ = R × C; where R is the resistance value of the resistor, and C is the capacity of the capacitor.

5. The low-power solenoid valve drive circuit according to claim 1, wherein The driving unit further comprises a MOS tube; The MOS tube is used to control the current output path of the power supply unit.

6. The low-power solenoid drive circuit of claim 5, wherein, The driving unit further comprises an inverter; The input port of the inverter is connected with the timing circuit; When the voltage across the first capacitor is less than a preset threshold, the output of the inverter is high; when the voltage across the first capacitor is greater than the preset threshold, the output of the inverter is low; When the inverter outputs high, the MOS tube is turned on, and the power supply unit directly supplies power to the electromagnetic valve; When the inverter outputs low, the MOS tube is closed, and the power supply unit supplies power to the electromagnetic valve through the current limiting resistor to realize low power consumption maintaining of the electromagnetic valve.

7. The low-power solenoid drive circuit of claim 1, wherein The driving unit further comprises a second resistor; The second resistor is connected in series between the power supply unit and the electromagnetic valve, and limits the current passing through the electromagnetic valve through its resistance value.

8. The low-power solenoid drive circuit of claim 1, wherein, The driving unit further comprises an inductor; The inductor is used for filtering and smoothing current.

9. An electromagnetic pilot valve characterized by comprising: Comprising the low power consumption electromagnetic valve driving circuit according to any one of claims 1-8.

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