Noise reduction method and control circuit for fuel heater plunger pump

Abstract

The present application relates to a noise reduction method and control circuit for a fuel heater plunger pump. The noise reduction method for a fuel heater plunger pump comprises the following steps: detecting the current value of the electromagnet of the plunger pump, calculating the current difference between the current value and the calibrated current value; if the current difference is greater than a preset value, adjusting the voltage of the electromagnet according to the current difference; repeating the above steps until the current difference is less than or equal to the preset value. The above-mentioned noise reduction method and control circuit for the fuel heater plunger pump detects the current value of the electromagnet of the plunger pump, and when the current difference between the current value and the calibrated current value exceeds a preset value, adjusts the voltage of the electromagnet according to the current difference, thereby reducing the current difference to less than or equal to the preset value, achieving a substantially constant suction force of the electromagnet, thereby improving the problem of increased noise of the plunger pump due to changes in the suction force of the electromagnet.

Description

Technical Field

[0001] The present disclosure relates to the field of auxiliary thermal management of new energy vehicles, and in particular to a noise reduction method and a control circuit for a fuel heater plunger pump. Background Art

[0002] New energy vehicles use power batteries to provide energy, which has the advantages of being quiet and having high energy supply efficiency. However, due to the limitation of the storage capacity of the power battery, it is difficult to provide heat to the vehicle while supplying energy. For this reason, in some new energy vehicles, a fuel heater can also be set to provide heat for the new energy vehicle through fuel combustion. The fuel heater requires a plunger pump to pulse the oil into the burner for combustion. The plunger pump has the advantages of low price, mature and convenient application, but because the plunger pump needs to use the suction force generated by the electromagnet through the coil to move the pump oil, noise will inevitably be generated during the movement of the electromagnet, especially when the suction force of the electromagnet changes, the noise of the electromagnet is more obvious. Summary of the invention

[0003] In view of the above, it is necessary to provide a noise reduction method and a control circuit for a fuel heater plunger pump, aiming to improve the noise problem of the fuel heater plunger pump.

[0004] To this end, the present invention first provides a method for reducing the noise of a fuel heater plunger pump, comprising the following steps:

[0005] Detecting the current value of the electromagnet of the plunger pump, and calculating the current difference between the current value and the calibrated current value;

[0006] If the current difference is greater than a preset value, adjusting the voltage of the electromagnet according to the current difference;

[0007] Repeat the above steps until the current difference is less than or equal to the preset value.

[0008] Preferably, detecting the current value of the electromagnet of the plunger pump includes:

[0009] The current flowing through the electromagnet is guided to the current sampling terminal of the controller through a feedback line connected to the electromagnet to detect the current value.

[0010] Preferably, adjusting the voltage of the electromagnet according to the current difference comprises: adjusting the duty cycle of the voltage according to the current difference to adjust the effective value of the voltage of the electromagnet.

[0011] Preferably, adjusting the voltage of the electromagnet according to the current difference comprises:

[0012] The duty cycle of the voltage is adjusted according to the following formula:

[0013]

[0014] Wherein, I is the current value of the electromagnet, U is the voltage value of the electromagnet, R is the resistance value of the electromagnet, and D is the duty cycle of the voltage.

[0015] Preferably, adjusting the voltage of the electromagnet comprises:

[0016] The controller controls the voltage of the electromagnet by outputting a chopping signal to the electromagnet, and adjusts the duty cycle of the chopping signal according to the current difference.

[0017] Preferably, the method further comprises: detecting the temperature of the plunger pump, and if the temperature is lower than a preset value, turning on the electromagnet so that the temperature of the electromagnet is greater than or equal to the preset value.

[0018] In addition, the present invention also provides a control circuit for a fuel heater plunger pump, comprising:

[0019] A driving circuit, connected to the electromagnet of the plunger pump, for driving the electromagnet of the plunger pump to pull the plunger of the plunger pump to pump out fuel when closed;

[0020] A feedback circuit, connected to the electromagnet, for feeding back the working current of the electromagnet;

[0021] A controller is connected to the driving circuit and the feedback circuit, and is used to execute the noise reduction method according to the current value fed back by the feedback circuit, and control the electromagnet through the driving circuit.

[0022] Preferably, the driving circuit comprises a switching device, and the switching device is connected to the coil of the electromagnet.

[0023] Preferably, the feedback circuit further comprises an amplifier, an input end of the amplifier is connected to the coil of the electromagnet, and an output end of the amplifier is connected to a sampling port of the controller.

[0024] Preferably, it also includes a temperature detection circuit, which includes a temperature sensor. The temperature sensor is connected to the controller and is used to detect the temperature of the plunger pump. When the temperature is lower than a preset value, the controller controls the coil of the electromagnet to conduct for a preset time through the drive circuit to preheat the plunger pump.

[0025] Compared with the prior art, the noise reduction method and control circuit of the above-mentioned fuel heater plunger pump detects the current value of the electromagnet of the plunger pump. When the current difference between the current value and the calibrated current value exceeds a preset value, the voltage of the electromagnet is adjusted according to the current difference, thereby reducing the current difference to less than or equal to the preset value, thereby achieving a basically constant suction force of the electromagnet, thereby improving the problem of increased noise of the plunger pump due to changes in the suction force of the electromagnet. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods, the drawings required for use in the description of the implementation methods will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 It is the schematic diagram of the control circuit of the fuel heater plunger pump.

[0028] Figure 2 It is a flow chart of a method for reducing noise of a fuel heater plunger pump.

[0029] Main component symbols

[0030] Controller 10 Chopping signal output terminal 11 AD current sampling terminal 12 Temperature detection terminal 13 Drive circuit 20 Coil 21 Feedback Circuit 30 Phase difference amplifier 31 Temperature detection circuit 40 Temperature Sensor 41

[0031] The following specific implementations will further illustrate the present disclosure in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0032] In order to more clearly understand the above-mentioned purposes, features and advantages of the present disclosure, the present disclosure is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth in order to fully understand the present disclosure, and the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used in the specification herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0034] In each embodiment, for the convenience of description and not to limit the present disclosure, the term "connection" used in the patent specification and claims of the present disclosure is not limited to physical or mechanical connection, but may include electrical connection, whether direct or indirect. "Up", "down", "below", "left", "right", etc. are only used to indicate relative position relationship. When the absolute position of the described object changes, the relative position relationship also changes accordingly.

[0035] The inventors found in practice that the resistance of the electromagnet coil 21 of the plunger pump will change as the working condition of the plunger pump changes or the working time increases. According to the suction formula of the electromagnet:

[0036]

[0037] Where B0 is the magnitude of the magnetic field (Tesla, T), S0 is the cross-sectional area of ​​the plunger (m 2 ), F is the suction force generated by the coil 21 (Newton, N).

[0038] It can be seen from the above formula that the magnitude of the electromagnet suction force is proportional to the cross-sectional area S0 of the air gap and the square of the magnetic induction intensity B0 in the air gap. When the structure of the plunger pump is fixed, the magnitude of the suction force F can be adjusted by changing the magnitude of the magnetic field.

[0039] The calculation formula of magnetic field strength is as follows:

[0040] B0=μ0×N×I

[0041] Among them, μ0 is a constant, N is the number of turns of the coil 21 of the electromagnet of the plunger pump, and I is the current (A) in the coil 21.

[0042] It can be seen from the formula of magnetic field strength that when the number of turns N of the coil 21 remains unchanged, the magnetic field strength is changed by changing the current I in the wire of the coil 21. Since the resistance of the coil 21 may change under the influence of environmental conditions or working time, when the voltage applied to the coil 21 remains unchanged, the current I of the coil 21 will change and affect the magnetic field B0 of the coil 21.

[0043] To this end, it is necessary to provide a noise reduction method, in which the control circuit of the above-mentioned fuel heater plunger pump adjusts the voltage according to the change of current, so that the change of current can be kept within the preset value when the resistance changes, thereby keeping the suction force of the coil 21 basically unchanged, maintaining the suction force of the electromagnet constant, and reducing the working noise of the plunger pump.

[0044] Figure 1 This is the schematic diagram of the control circuit of the fuel heater plunger pump. Figure 1As shown, the control circuit of the fuel heater plunger pump includes a controller 10, a drive circuit 20, a feedback circuit 30 and a temperature detection circuit 40. The controller 10 can drive the electromagnet of the fuel heater plunger pump through the drive circuit 20 to realize pulse oil pumping action, obtain the current of the electromagnet through the feedback circuit 30, and obtain the ambient temperature of the piston oil pump through the temperature detection circuit 40.

[0045] The various programs and data installed in the controller 10 are used to control the action of the electromagnet of the plunger pump. The controller 10 includes but is not limited to a central processing unit (CPU), a microcontroller unit (MCU), etc., which are used to interpret computer instructions and process data in computer software. In this embodiment, the controller 10 includes three ports: a chopping signal output terminal 11, an AD current sampling terminal 12, and a temperature detection terminal 13, wherein the chopping signal output terminal 11 is an output terminal, connected to the drive circuit 20, and used to output a PWM chopping signal. The AD current sampling terminal 12 is an input terminal, which is used to receive the current signal fed back by the feedback circuit 30, and the corresponding module inside the controller 10 performs AD sampling on the received current signal to realize the digital processing of the current signal. The temperature detection terminal 13 is an input terminal, which is used to receive the current or voltage signal of the temperature detection circuit 40, and the corresponding module inside the controller 10 can sample and process the current or voltage signal, and convert it into a digital signal to obtain the ambient temperature of the fuel heater plunger pump.

[0046] The driving circuit 20 is connected to the electromagnet of the plunger pump, and is used to drive the electromagnet of the plunger pump to pull the plunger of the plunger pump to pump out fuel when closed. In this embodiment, the driving circuit 20 includes a switching device, and the switching device is connected to the coil 21 of the electromagnet. Specifically, the switching device includes transistors Q1 and Q2, and a MOS tube Q3. The transistor Q1 is a PNP type transistor, the base is connected to the chopping signal output terminal 11 of the controller 10, and the collector is connected to the base of the transistor Q2. The transistor Q2 is an NPN type transistor, and its collector is connected to the gate of the MOS tube. The coil 21 of the electromagnet of the plunger pump is connected to the power supply at one end, and the MOS tube is connected at the other end. The connection or disconnection of the coil 21 can be controlled by connecting or disconnecting the two ends of the MOS tube. During use, when the MOS tube is turned on, the coil 21 generates suction from the power supply and moves in the plunger pump to pump out oil. When the MOS tube is disconnected, the coil 21 loses power so that the plunger pump serves under the action of the reset spring. The chopping signal generated by the controller 10 controls the MOS tube to be turned on or off through the transistors Q1 and Q2, thereby realizing the power-on-power-off cycle of the coil 21, thereby controlling the electromagnet to continuously cycle and pump oil to the burner in a pulsed manner.

[0047] The feedback circuit 30 is connected to the electromagnet and is used to feed back the working current of the electromagnet. In this embodiment, the feedback circuit 30 includes a phase difference amplifier 31, and the input end of the phase difference amplifier 31 is connected to the MOS tube, so that the current of the coil 21 can be introduced. The output end of the phase difference amplifier 31 is connected to the AD current sampling end 12 of the controller 10, which is used to receive the current signal amplified by the phase difference amplifier 31. During the operation, the magnitude of the current (i.e., the current value) of the coil 21 of the electromagnet can be detected in real time through the feedback circuit 30.

[0048] The temperature detection circuit 40 includes a temperature sensor 41, which is connected to the controller 10 and is used to detect the ambient temperature of the plunger pump. When the temperature is lower than a preset value, the controller 10 controls the coil 21 of the electromagnet to conduct for a preset time through the drive circuit 20 to preheat the plunger pump.

[0049] Figure 2 The following is a flow chart of the noise reduction method for the fuel heater plunger pump. Figure 2 As shown, the noise reduction method includes steps S201 to S203.

[0050] Step S201: Detect the current value of the electromagnet of the plunger pump. In this step, the current flowing through the electromagnet is guided to the current sampling terminal of the controller 10 by connecting the feedback circuit of the electromagnet to detect the current value. Specifically, the current value flowing through the coil 21 of the electromagnet can be obtained through the feedback circuit 30, and the corresponding module inside the controller 10 can convert the current signal into a corresponding digital signal to obtain the current value of the current of the coil 21 in real time.

[0051] Step S202: Calculate the current difference between the current value and the calibrated current value. In this step, the controller 10 can perform a difference operation based on the acquired current value and the calibrated current value stored in the internal storage space of the controller 10 to obtain the absolute value of the current value and the calibrated current value, that is, the current difference.

[0052] Step S203: If the current difference is greater than a preset value, the voltage of the electromagnet is adjusted according to the current difference. In this step, the duty cycle of the voltage is adjusted according to the current difference to adjust the effective value of the voltage of the electromagnet. Specifically, the duty cycle of the voltage is adjusted according to the following formula:

[0053]

[0054] Wherein, I is the current value of the electromagnet, U is the voltage value of the electromagnet, R is the resistance value of the electromagnet, and D is the duty cycle of the voltage. The controller 10 controls the voltage of the electromagnet by outputting a chopping signal to the electromagnet, and adjusts the duty cycle of the chopping signal according to the current difference.

[0055] Finally, the above steps are repeated until the current difference is less than or equal to the preset value.

[0056] In addition, the inventors also found in practice that the hardening of the rubber plug in the oil pump at low temperatures will also increase the working noise of the plunger pump. For this reason, in this embodiment, before the plunger pump works, the controller 10 detects the ambient temperature through the temperature detection circuit 40. If the temperature is lower than the preset value, the electromagnet is turned on so that the temperature of the electromagnet is greater than or equal to the preset value. By giving the plunger pump a certain preheating voltage and keeping it for a period of time, the purpose of preheating the inner rubber plug of the plunger pump is achieved, thereby reducing the noise when the oil pump is working.

[0057] The above-mentioned noise reduction method and control circuit of the fuel heater plunger pump detects the current value of the electromagnet of the plunger pump. When the current difference between the current value and the calibrated current value exceeds a preset value, the voltage of the electromagnet is adjusted according to the current difference, thereby reducing the current difference to less than or equal to the preset value, thereby achieving a basically constant suction force of the electromagnet. This can not only improve the problem of increased noise of the plunger pump due to changes in the suction force of the electromagnet, but also ensure that the electromagnet can maintain sufficient pulse suction to ensure the reliability of fuel supply.

[0058] In addition, the noise reduction method and control circuit of the above-mentioned fuel heater plunger pump also detects the ambient temperature before the plunger pump works, and preheats the plunger pump by generating heat through continuous conduction of the coil 21 of the plunger pump, thereby reducing the hardness of the inner rubber plug and further improving the noise problem of the plunger pump.

[0059] In the several specific embodiments provided in the present disclosure, it is obvious to those skilled in the art that the present disclosure is not limited to the details of the above exemplary embodiments, and that the present disclosure can be implemented in other specific forms without departing from the spirit or basic features of the present disclosure. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present disclosure is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present disclosure. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0060] The above embodiments are only used to illustrate the technical solution of the present disclosure rather than to limit it. Although the present disclosure is described in detail with reference to the above preferred embodiments, those skilled in the art should understand that the technical solution of the present disclosure can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present disclosure.

Claims

1. A method for reducing noise of a fuel heater plunger pump, characterized in that: The following steps are involved: Detecting the current value of the electromagnet of the plunger pump, and calculating the current difference between the current value and the calibrated current value; If the current difference is greater than a preset value, adjusting the voltage of the electromagnet according to the current difference; Adjusting the voltage of the electromagnet according to the current difference includes: adjusting the duty cycle of the voltage according to the current difference to adjust the effective value of the voltage of the electromagnet; adjusting the voltage of the electromagnet according to the current difference includes: The duty cycle of the voltage is adjusted according to the following formula: Wherein, I is the current value of the electromagnet, U is the voltage value of the electromagnet, R is the resistance value of the electromagnet, and D is the duty cycle of the voltage; the controller controls the voltage of the electromagnet by outputting a chopping signal to the electromagnet, and adjusts the duty cycle of the chopping signal according to the current difference; Repeat the above steps until the current difference is less than or equal to the preset value; Detecting the current value of the electromagnet of the plunger pump includes: The current flowing through the electromagnet is guided to the current sampling terminal of the controller through a feedback line connected to the electromagnet to detect the current value; The method further includes: detecting the temperature of the plunger pump, and if the temperature is lower than a preset value, turning on the electromagnet so that the temperature of the electromagnet is greater than or equal to the preset value.

2. A control circuit for a fuel heater plunger pump, characterized in that: include: A driving circuit, connected to the electromagnet of the plunger pump, for driving the electromagnet of the plunger pump to pull the plunger of the plunger pump to pump out fuel when closed; A feedback circuit, connected to the electromagnet, for feeding back the working current of the electromagnet; A controller, connected to the drive circuit and the feedback circuit, configured to execute the noise reduction method according to claim 1 according to the current value fed back by the feedback circuit, and control the electromagnet through the drive circuit; It also includes a temperature detection circuit, which includes a temperature sensor. The temperature sensor is connected to the controller and is used to detect the temperature of the plunger pump. When the temperature is lower than a preset value, the controller controls the coil of the electromagnet to conduct for a preset time through the drive circuit to preheat the plunger pump.

3. The control circuit of the fuel heater plunger pump according to claim 2, characterized in that: The driving circuit includes a switching device connected to the coil of the electromagnet.

4. The control circuit of the fuel heater plunger pump according to claim 3, characterized in that: The feedback circuit further comprises an amplifier, an input end of the amplifier is connected to the coil of the electromagnet, and an output end of the amplifier is connected to the sampling port of the controller.

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