Starter isolation circuit, device and automobile

Abstract

The present application provides a starter isolation circuit, device and automobile. The circuit includes: a battery, a DC converter, a switch structure, a vehicle controller, an analog switch, a starter and a starter relay; the switch structure includes a control end; wherein the battery is connected to the switch structure, and the switch structure is connected to the DC converter; the vehicle controller is connected to the battery and the analog switch respectively, and the analog switch is connected to the control end; the vehicle controller is used to control the starter relay to close and control the analog switch to disconnect if it is determined that the starter starts the engine; the control end is used to control the switch structure to be only unidirectional when the analog switch is disconnected, so that when the starter starts the engine, the DC converter stops charging the battery. The circuit of the present application isolates the battery and the DC converter when the starter starts the engine, avoids the situation of pulling down the DC converter voltage, improves driving safety, and protects the DC converter from being burned.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a starting isolation circuit and device of a starter and an automobile. Background Art

[0002] Since hybrid power systems can achieve good fuel-saving effects and are low in cost, they are widely used in automobiles. In hybrid power systems, there are usually two engine starting methods: motor starting and starter starting, which are suitable for different automobile working conditions.

[0003] In the prior art, after receiving the engine start request, the vehicle controller determines whether the vehicle meets the conditions for the motor to start the engine. If the conditions are met, the motor is controlled to start the engine; if the conditions are not met, the starter is controlled to start the engine. However, in the existing low-voltage circuit, when the starter starts the engine, the battery needs to supply power to the starter, and the DC converter will also be involved in the starting process. In the transient state when the starter drags the engine, the battery voltage is pulled down, and the voltage of the DC converter connected to the battery will also be pulled down. At this time, not only is the driving safety not high, but when the voltage of the DC converter is lower than a certain value, it will also cause the DC converter to report an overcurrent fault, and there is even a risk of burning the DC converter fuse.

[0004] Therefore, it is necessary to control the process of starting the engine by the starter to improve driving safety. Summary of the invention

[0005] The present application provides a starting isolation circuit, device and automobile of a starter, so as to solve the problems in the prior art that, in the transient state when the starter drags the engine, the voltage of the DC converter will be pulled down, thereby resulting in low driving safety and causing the DC converter to report an overcurrent fault.

[0006] On the one hand, the present application provides a starter isolation circuit for a starter, the starter isolation circuit comprising: a battery, a DC converter, a switch structure, a vehicle controller, an analog switch, a starter and a starter relay; the switch structure comprises a control end;

[0007] The battery is connected to the switch structure, and the switch structure is connected to the DC converter; the vehicle controller is connected to the battery and the analog switch respectively, and the analog switch is connected to the control end;

[0008] The vehicle controller is used to control the starter relay to close and the analog switch to open if it is determined that the engine is started by the starter;

[0009] The control end is used to control the switch structure to conduct only in one direction when the analog switch is disconnected, so that when the engine is started by the starter, the DC converter stops charging the battery.

[0010] Optionally, the switch structure includes a diode and a switch element, and the switch element includes a first connection terminal, a second connection terminal, and a control terminal;

[0011] The first connection end is connected to the positive electrode of the diode and the battery, and the second connection end is connected to the negative electrode of the diode and the DC converter;

[0012] The diode is used to achieve unidirectional conduction from the battery to the DC converter;

[0013] The control end is used to disconnect the switch element when the analog switch is disconnected, so that when the engine is started by the starter, the DC converter stops charging the battery.

[0014] Optionally, the switch element comprises a MOS tube, a source of the MOS tube is the first connection end, a drain of the MOS tube is the second connection end, and a gate of the MOS tube is the control end;

[0015] The gate of the MOS tube is used to turn off the MOS tube when the analog switch is disconnected, so that when the engine is started by the starter, the DC converter stops charging the battery.

[0016] Optionally, the vehicle controller is further used to close or open the analog switch according to the power level of the battery after completing the starting control of the starter, so that the DC converter charges or does not charge the battery;

[0017] Wherein, when the analog switch is closed, the vehicle controller also provides the control end with a control voltage capable of controlling the closing of the switch structure, so that the DC converter charges the battery.

[0018] Optionally, the vehicle controller includes a micro control unit and an amplifier circuit;

[0019] The micro control unit is connected to the analog switch and the input end of the amplifier circuit respectively, the input end of the amplifier circuit is also connected to the battery, and the output end of the amplifier circuit is connected to the analog switch;

[0020] The micro control unit is used for controlling the starter relay to close and the analog switch to open if it is determined that the engine is started by the starter;

[0021] The microcontroller unit is also used to close or open the analog switch according to the power level of the battery after completing the starting control of the starter, so that the DC converter charges or does not charge the battery;

[0022] The amplifier circuit is used to provide the control terminal with a control voltage capable of controlling the switch structure to be closed when the analog switch is closed, so that the DC converter charges the battery.

[0023] Optionally, the amplifier circuit comprises a transistor, the base of the transistor is the input end of the amplifier circuit, the collector of the transistor is the output end of the amplifier circuit, and the emitter of the transistor is grounded;

[0024] The transistor is used to provide the control terminal with a control voltage capable of controlling the switch structure to be closed when the analog switch is closed, so that the DC converter charges the battery.

[0025] Optionally, the amplifying circuit further includes a capacitor, one end of which is connected to the collector of the transistor, and the other end of which is grounded, and the capacitor is used to filter the control voltage.

[0026] Optionally, the starting isolation circuit also includes a battery monitoring sensor, which is connected to the battery and is used to monitor the power level of the battery and provide the battery power information to the vehicle controller.

[0027] On the other hand, the present application provides a starting isolation device for a starter, comprising a starting isolation circuit as described in any one of the above items.

[0028] On the other hand, the present application also provides a car, comprising the starting isolation circuit as described in any one of the above items.

[0029] The application provides a starter isolation circuit, device and automobile for a starter, wherein the starter isolation circuit includes: a battery, a DC converter, a switch structure, a vehicle controller, an analog switch, a starter and a starter relay; the switch structure includes a control end; wherein the battery is connected to the switch structure, and the switch structure is connected to the DC converter; the vehicle controller is respectively connected to the battery and the analog switch, and the analog switch is connected to the control end; the vehicle controller is used to control the starter relay to close and control the analog switch to disconnect if it is determined that the starter starts the engine; the control end is used to control the switch structure to be only unidirectional when the analog switch is disconnected, so that when the starter starts the engine, the DC converter stops charging the battery. By setting the switch structure and controlling the disconnection of the analog switch through the vehicle controller, the switch structure is disconnected, so that when the starter starts the engine, the battery and the DC converter are isolated. It avoids pulling down the voltage of the DC converter when the starter starts the engine, which not only improves driving safety, but also protects the DC converter from being burned. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0031] Figure 1 A schematic diagram of a starting isolation circuit of a starter provided in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of a starting isolation circuit of another starter provided in an embodiment of the present application;

[0033] Figure 3 A flow chart of a control logic based on a starting isolation circuit provided in an embodiment of the present application.

[0034] Reference numerals:

[0035] 10-battery; 20-DC converter; 30-switch structure; 301-control end; 31-diode; 32-switch element; 321-first connection end; 322-second connection end; 40-vehicle controller; 41-micro control unit; 42-amplifier circuit; 421-transistor; 422-capacitor; 50-analog switch; 60-starter; 70-starter relay; 80-low-voltage power supply load.

[0036] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0037] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0038] The terms "positive electrode", "negative electrode", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0039] The hybrid system that couples a single motor on the even-numbered shafts of a dual-clutch transmission can achieve better fuel-saving effects. It also has the advantages of low cost and short development cycle. Therefore, it is widely used in the automotive industry.

[0040] In a hybrid power system, two engine starting methods are usually set up: motor starting and starter starting, which are suitable for different vehicle working conditions. Among them, the motor starting engine is generally used to start the car in situ or when the car has a certain speed; the starter starting is generally used when the speed is low or when the motor, power battery, etc. fail. The starter starts the engine by converting the battery's electrical energy into mechanical energy and starting the engine flywheel to rotate. As a backup starting method, the reliability and stability of the starter starting directly affect the safety of the driving system. Among them, common starters include 6V, 12V, 24V starters, etc., which can be configured according to the needs of the car.

[0041] In one example, when the vehicle controller of a car receives a request to start the engine, it will determine whether the car meets the conditions for the motor to start the engine based on the current actual vehicle condition, that is, whether the car is starting in situ or whether the vehicle speed meets the motor starting speed. If it is determined that the conditions for the motor to start the engine are met, the vehicle controller uses the motor to start the engine to start the engine; if it is determined that the conditions for the motor to start the engine are not met, such as when the vehicle speed is low or the motor, power battery, etc. are faulty, the vehicle controller controls the starter to start the engine to start the engine.

[0042] When the engine is started by the starter, the vehicle controller sends injection and ignition commands to the engine controller, and sends a closing command to the starter relay. After the relay is closed, the starter starts to drive the engine. When the engine is dragged to a certain speed, the engine injects fuel and ignites, completing the starter starting process.

[0043] Among them, the starter drives the engine, and the battery is required to supply power to the starter. However, in the low-voltage circuit of the current hybrid system, the DC converter is connected to the battery, and the DC converter will also participate in the starting process. In the transient state when the starter drives the engine, the voltage of the battery will be pulled down, and at the same time, the voltage of the DC converter connected to the battery will also be pulled down. At this time, the vehicle controller of the car is at risk of power failure, resulting in reduced safety of the vehicle; moreover, when the voltage of the DC converter is lower than a certain value, it will also cause the DC converter to report an overcurrent fault, and there is even a risk of burning the DC converter fuse.

[0044] In order to solve the above-mentioned problem, the present application provides a starting isolation circuit, device and automobile of a starter, by setting a switch structure and an analog switch between the battery and the DC converter, and controlling the analog switch to be disconnected through the vehicle controller when the starter starts the engine, so that the switch structure is only unidirectionally conductive, thereby achieving the purpose that the DC converter will not be pulled down in voltage by the starter when the starter starts the engine.

[0045] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0046] Figure 1 A schematic diagram of a starter isolation circuit of a starter provided in an embodiment of the present application. Figure 1 As shown, the starting isolation circuit includes: a battery 10, a DC converter 20, a switch structure 30, a vehicle controller 40, an analog switch 50, a starter 60 and a starter relay 70; wherein the switch structure 30 includes a control terminal 301.

[0047] like Figure 1 As shown, the battery 10 is connected to the switch structure 30 , and the switch structure 30 is connected to the DC converter 20 ; the vehicle controller 40 is respectively connected to the battery 10 and the analog switch 50 , and the analog switch 50 is connected to the control terminal 301 .

[0048] The vehicle controller 40 is used to control the starter relay 70 to close and the analog switch 50 to open if it is determined that the engine is started by the starter 60 .

[0049] The control terminal 301 is used to control the switch structure 30 to be only unidirectionally conductive when the analog switch 50 is disconnected, so that when the engine is started by the starter 60 , the DC converter 20 stops charging the battery 10 .

[0050] Exemplarily, the vehicle controller 40 is the control center of the vehicle. After the high voltage of the vehicle is powered on, if the vehicle controller 40 receives a start request of the engine, the vehicle controller 40 will determine whether the engine is started by the starter 60 according to the actual working condition of the current vehicle. If it is determined that the engine is started by the starter 60, the vehicle controller 40 sends a closing instruction to the starter relay 70 to control the starter relay 70 to close so that the battery 10 supplies power to the starter 60; at the same time, the vehicle controller 40 also controls the analog switch 50 to be disconnected so that the control end 301 controls the switch structure 30 to be only unidirectionally conducted, so that the DC converter 20 stops charging the battery 10, so as to avoid the voltage of the DC converter 20 being pulled down in the transient state when the battery 10 supplies power to the starter 60.

[0051] Exemplarily, when the analog switch 50 is disconnected, the control end 301 controls the switch structure 30 to be disconnected; when the analog switch 50 is closed, the control end 301 controls the switch structure 30 to be closed. Among them, the present application does not limit the specific implementation method of the switch structure 30. For example, it can be implemented by a diode and a relay in parallel, or by a diode and a MOS tube in parallel. In addition, it can also be implemented in other ways, which are not limited by the present application. The purpose of setting the switch structure 30 of the present application is to: when the switch structure 30 is disconnected, realize the unidirectional conduction from the battery 10 to the DC converter 20, so that when the DC converter 20 is not working, the battery 10 can supply power to the low-voltage power supply load 80; and when the switch structure 30 is closed, the DC converter 20 can charge the battery 10.

[0052] Among them, when the analog switch 50 is disconnected, the control end 301 controls the switch structure 30 to be disconnected, that is, at this time, the switch structure 30 only unidirectionally conducts the battery 10 to the DC converter 20, and the battery 10 can supply power to the low-voltage power supply load 80, but at this time the DC converter 20 cannot charge the battery 10; thereby achieving the goal of isolating the battery 10 and the DC converter 20 when the starter starts the engine.

[0053] The starter isolation circuit of the starter provided in the embodiment of the present application includes: a battery, a DC converter, a switch structure, a vehicle controller, an analog switch, a starter and a starter relay; the switch structure includes a control end; wherein the battery is connected to the switch structure, and the switch structure is connected to the DC converter; the vehicle controller is respectively connected to the battery and the analog switch, and the analog switch is connected to the control end; the vehicle controller is used to control the starter relay to close and control the analog switch to disconnect if it is determined that the engine is started by the starter; the control end is used to control the switch structure to be only unidirectional when the analog switch is disconnected, so that when the engine is started by the starter, the DC converter stops charging the battery. The present application sets a switch structure between the battery and the DC converter, and controls the disconnection of the analog switch by the vehicle controller to control the disconnection of the switch structure, so as to isolate the battery from the DC converter when the engine is started by the starter. It avoids the situation where the voltage of the DC converter is pulled down when the engine is started by the starter, which not only improves driving safety, but also protects the DC converter from being ablated.

[0054] Figure 2 A schematic diagram of another starter isolation circuit provided in an embodiment of the present application. Figure 2 As shown, the starting isolation circuit includes: a battery 10, a DC converter 20, a switch structure 30, a vehicle controller 40, an analog switch 50, a starter 60 and a starter relay 70; wherein the switch structure 30 includes a diode 31 and a switch element 32, and the switch element 32 includes a first connection terminal 321, a second connection terminal 322, and a control terminal 301.

[0055] like Figure 2 As shown, the first connection end 321 of the switch element 32 is connected to the positive electrode of the diode 31 and the battery 10, and the second connection end 322 of the switch element 32 is connected to the negative electrode of the diode 31 and the DC converter 20; the vehicle controller 40 is respectively connected to the battery 10 and the analog switch 50, and the analog switch 50 is connected to the control end 301.

[0056] Among them, the vehicle controller 40 is used to control the starter relay 70 to close and control the analog switch 50 to open if it is determined that the engine is started by the starter 60; the control end 301 is used to disconnect the switch element 32 when the analog switch 50 is disconnected, so that when the engine is started by the starter 60, the DC converter 20 stops charging the battery 10; the diode 31 is used to realize unidirectional conduction from the battery 10 to the DC converter 20.

[0057] For example, after the high voltage of the automobile is powered on, if the vehicle controller 40 determines that the engine is started by the starter 60, the vehicle controller 40 controls the starter relay 70 to close so that the battery 10 supplies power to the starter 60; at the same time, the vehicle controller 40 also controls the analog switch 50 to be disconnected, so that the control end 301 controls the first connection end 321 and the second connection end 322 of the switch element 32 to be disconnected, so that the DC converter 20 stops charging the battery 10, and only conducts the battery 10 to the DC converter 20 in a unidirectional manner through the diode 31, so that the battery 10 can still supply power to the low-voltage power supply load 80. Thus, the starter is isolated from the starter, and the impact of the starter on the entire power supply circuit when starting the engine is reduced.

[0058] Exemplarily, the diode has unidirectional conductivity. The present application sets a diode 31 in the switch structure 30 to achieve unidirectional conduction from the battery 10 to the DC converter 20, so that when the DC converter 20 is not working, the battery 10 can supply power to the low-voltage power supply load 80. In addition, the switch structure 30 also includes a switch element 32, and the switch element 32 includes a control terminal 301, and the control terminal 301 is used to control the connection between the first connection terminal 321 and the second connection terminal 322.

[0059] When the analog switch 50 is disconnected, the control end 301 controls the first connection end 321 and the second connection end 322 to be disconnected, and when the analog switch 50 is closed, the control end 301 controls the first connection end 321 and the second connection end 322 to be closed. When the first connection end 321 and the second connection end 322 are disconnected, the diode 31 is used to realize unidirectional conduction from the battery 10 to the DC converter 20, so that the battery 10 supplies power to the low-voltage power supply load 80, and the DC converter 20 cannot charge the battery 10 at this time; when the first connection end 321 and the second connection end 322 are closed, the conduction from the DC converter 20 to the battery 10 is realized, and the DC converter 20 can charge the battery 10.

[0060] The analog switch 50 in the present application may be a normally closed switch.

[0061] In one example, the switch element 32 includes a MOS tube, a source of the MOS tube is a first connection terminal 321, a drain of the MOS tube is a second connection terminal 322, and a gate of the MOS tube is a control terminal 301; the gate of the MOS tube is used to cut off the MOS tube when the analog switch 50 is disconnected, so that when the engine is started by the starter, the DC converter stops charging the battery.

[0062] Exemplarily, when the analog switch 50 is disconnected, the gate of the MOS tube is grounded. At this time, the MOS tube is cut off, thereby isolating the battery 10 from the DC converter 20. At this time, the DC converter 20 cannot charge the battery 10. When the analog switch 50 is closed, the gate of the MOS tube conducts the source and the drain, and the DC converter 20 can charge the battery 10.

[0063] Among them, if the switching element 32 includes a MOS tube, the gate of the MOS tube controls the conduction or cutoff of the MOS tube. When the analog switch 50 is closed, in order to achieve conduction between the source and the drain of the MOS tube, the vehicle controller also provides a control voltage greater than the source voltage to the gate of the MOS tube.

[0064] Among them, the MOS tube has the advantages of good real-time response performance and long life. On the one hand, it can improve the control efficiency of the entire starting isolation circuit, and on the other hand, it can minimize the impact of the starter on the DC converter when starting the engine.

[0065] In one example, the vehicle controller 40 is also used to close or open the analog switch 50 according to the power of the battery 10 after completing the starting control of the starter 60, so that the DC converter 20 charges or does not charge the battery 10; wherein, when the analog switch 50 is closed, the vehicle controller 40 also provides a control voltage capable of controlling the closing of the switch structure 30 to the control terminal 301, so that the DC converter 20 charges the battery 10.

[0066] For example, after the starting control of the starter 60 is completed, the battery 10 and the DC converter 20 will no longer be pulled down in voltage by the starter 60. At this time, the battery 10 and the DC converter 20 can be normally connected or disconnected as needed to realize the charging and discharging control of the battery.

[0067] For example, when the battery has a high charge level, continued charging will cause gassing due to excessive voltage, shortening the battery life, reducing charging efficiency, and increasing energy consumption. Therefore, it is necessary to control the charge and discharge of low-voltage batteries.

[0068] Exemplarily, the vehicle controller 40 can monitor the power of the battery 10 in real time. After completing the starting control of the starter 60, the vehicle controller 40 can determine whether the battery 10 needs to be charged according to the power of the battery 10, and close or open the analog switch 50 to enable the DC converter 20 to charge or not charge the battery 10. When the battery 10 needs to be charged, the vehicle controller 40 controls the analog switch 50 to be closed, and provides the control terminal 301 with a control voltage that can control the switch structure 30 to be closed, so that the DC converter 20 charges the battery 10. When the battery 10 does not need to be charged, the vehicle controller 40 controls the analog switch 50 to be opened, so that the DC converter 20 stops charging the battery 10.

[0069] The power of the battery 10 can be obtained through a variety of methods such as a battery monitoring sensor and a battery monitoring system, which are not limited in this application. In one example, the starting isolation circuit also includes a battery monitoring sensor (not shown in the figure), which is connected to the battery 10. The battery monitoring sensor is used to monitor the power of the battery 10 and provide the battery power information to the vehicle controller 40.

[0070] Exemplarily, the battery monitoring sensor monitors the power information of the battery 10 in real time and sends the real-time power information to the vehicle controller 40, so that the vehicle controller 40 can control the charging and discharging of the battery 10 in time according to the power of the battery 10 after completing the starting control of the starter 60.

[0071] The present application does not limit how the vehicle controller 40 provides the control terminal 301 with a control voltage capable of controlling the switch structure 30 to close. For example, the vehicle controller 40 includes an amplifier circuit, and the amplifier circuit provides the control voltage to the control terminal 301; or it can be implemented in other feasible ways.

[0072] In one example, the vehicle controller 40 includes a micro control unit 41 and an amplifier circuit 42 .

[0073] like Figure 2 As shown, the micro control unit 41 is connected to the analog switch 50 and the input end of the amplifier circuit 42 respectively. The input end of the amplifier circuit 42 is also connected to the battery 10 , and the output end of the amplifier circuit 42 is connected to the analog switch 50 .

[0074] The micro control unit 41 is used for controlling the starter relay 70 to close and the analog switch 50 to open if it is determined that the engine is started by the starter 60 .

[0075] The micro control unit 41 is also used to close or open the analog switch 50 according to the power level of the battery 10 after completing the starting control of the starter 60, so that the DC converter 20 charges the battery 10 or not.

[0076] The amplifier circuit 42 is used to provide a control voltage capable of controlling the switch structure 30 to be closed to the control terminal 301 when the analog switch 50 is closed, so that the DC converter 20 charges the battery 10 .

[0077] For example, after the automobile is powered on at high voltage, if the microcontroller unit 41 determines that the engine is started by the starter 60, the microcontroller unit 41 controls the starter relay 70 to close so that the battery 10 supplies power to the starter 60; at the same time, the microcontroller unit 41 also controls the analog switch 50 to be disconnected so that the control end 301 controls the switch element 32 in the switch structure 30 to be disconnected, so that the DC converter 20 stops charging the battery 10. At this time, the battery 10 is only unidirectionally conducted to the DC converter 20 through the diode 31, so that the battery 10 can still supply power to the low-voltage power supply load 80. Thus, the starter is isolated and the impact on the entire power supply circuit is reduced.

[0078] After completing the starting control of the starter 60, the micro control unit 41 is also used to realize the charge and discharge control of the battery 10. Exemplarily, the micro control unit 41 can determine whether the battery 10 needs to be charged according to the power of the battery 10, so as to control the analog switch 50 to be closed or disconnected, so as to realize the control of the DC converter 20 to charge or not charge the battery 10. Among them, when the battery 10 needs to be charged, the micro control unit 41 controls the analog switch 50 to be closed, and provides a PWM control signal to the amplifier circuit 42. The amplifier circuit 42 adjusts the voltage input by the battery 10 according to the PWM control signal, so that the output control voltage can make the control end 301 control the switch element 32 in the switch structure 30 to be closed. When the control end 301 receives the control voltage enough to control the switch element 32 in the switch structure 30 to be closed, the control switch element 32 is closed so that the DC converter 20 charges the battery 10. When the storage battery 10 does not need to be charged, the micro control unit 41 controls the analog switch 50 to be disconnected. At this time, the control terminal 301 is grounded, the switch structure 30 is disconnected, and the DC converter 20 stops charging the storage battery 10 .

[0079] The present application does not limit the specific value of the control voltage that can control the switch structure to close. For example, if the switch structure includes a MOS tube, and the gate of the MOS tube controls its conduction, it should be ensured that the voltage reaching the gate is greater than the source voltage, and only then will the MOS tube be turned on.

[0080] In one example, the amplifier circuit 42 includes a transistor 421, the base of the transistor 421 is the input terminal of the amplifier circuit 42, the collector of the transistor 421 is the output terminal of the amplifier circuit 42, and the emitter of the transistor 421 is grounded; the transistor 421 is used to provide a control voltage capable of controlling the closing of the switch structure 30 to the control terminal 301 when the analog switch 50 is closed, so that the DC converter 20 charges the battery 10.

[0081] Exemplarily, the transistor 421 can adjust the voltage input from the battery 10 according to the PWM control signal provided by the micro control unit 41, and control the output voltage to be stable at a control voltage capable of controlling the switch structure 30 to be closed.

[0082] In one example, the amplifier circuit 42 further includes a capacitor 422 , one end of the capacitor 422 is connected to the collector of the transistor 421 , and the other end of the capacitor 422 is grounded. The capacitor 422 is used to filter the control voltage.

[0083] For example, Figure 2 As shown, the amplifier circuit 42 may further include a capacitor 422, one end of which is connected to the collector of the transistor 421, and the other end of which is grounded. The capacitor 422 may filter the control voltage output by the transistor 421 that can control the switch structure 30 to close, so that the output control voltage is more stable, thereby improving the control effect.

[0084] In addition, in the starting isolation circuit of the present application, a diode may be provided at any necessary position to achieve unidirectional conduction between the devices, and the present application does not impose any limitation thereto.

[0085] The starter isolation circuit of the starter provided in the embodiment of the present application is provided with a switch structure between the battery and the DC converter, and the vehicle controller controls the disconnection of the analog switch to control the disconnection of the switch structure, so that when the starter starts the engine, the battery and the DC converter are isolated, and the situation of lowering the voltage of the DC converter when the starter starts the engine is avoided, thereby improving driving safety and protecting the DC converter from being ablated. In addition, the starter isolation circuit of the starter provided in the embodiment of the present application can also be used for battery charge and discharge control, which is more practical.

[0086] Figure 3 A flow chart of a control logic based on a starting isolation circuit provided in an embodiment of the present application.

[0087] The following is based on Figure 2 The starter isolation circuit shown in the figure is combined with Figure 3 The control process of battery charging and discharging and starter isolation in this application is introduced in three cases.

[0088] For example, when the car is powered on at a low voltage, because the analog switch 50 in the starting isolation circuit of the starter is in a normally closed state, the gate voltage of the MOS tube in the switch structure 30 is higher than the source voltage after the low voltage is powered on, and the battery 10 and the DC converter 20 are turned on. Since high voltage power is not supplied, the DC converter 20 cannot output electrical energy and cannot charge the battery 10. The low-voltage energy consumption of the entire vehicle is provided by the battery 10.

[0089] Exemplarily, when the high voltage of the car is powered on, but the starter is not used to start the engine, the starting isolation circuit is only used to complete the charge and discharge control of the battery 10. Under this working condition, the vehicle controller 40 receives the power information of the battery 10 and determines whether charging is required based on the power of the battery 10. If the DC converter 20 is required to charge the battery 10, the analog switch 50 is kept in a normally closed state. At this time, the gate voltage of the MOS tube is higher than the source voltage, the source and drain of the MOS tube are turned on, and the low-voltage terminal voltage of the DC converter 20 is higher than the voltage of the battery 10. The DC converter 20 provides power to the low-voltage load while charging the battery 10. When the DC converter 20 is not needed to charge the battery 10, the vehicle controller 40 controls the analog switch 50 to be disconnected. At this time, the gate of the MOS tube is grounded, the source and drain are cut off, and only one-way conduction is conducted through the diode. The DC converter 20 is disconnected from the battery 10, and the DC converter 20 stops charging the battery 10.

[0090] For example, when the high voltage of the automobile is powered on, not only the starter is used to start the engine, but the starting isolation circuit is also used to complete the charge and discharge control of the battery 10. Under this working condition, when the battery 10 does not need to be charged, the analog switch 50 is controlled to be disconnected to isolate the DC converter 20 from the battery 10. At this time, the DC converter 20 can supply power to the low-voltage load of the entire vehicle alone; when the battery 10 needs to be charged, the analog switch 50 is controlled to be closed to connect the DC converter 20 and the battery 10. The DC converter 20 supplies power to the low-voltage load of the entire vehicle while charging the battery 10. When it is determined that the engine needs to be started by the starter 60, the analog switch 50 is controlled to be disconnected, so that the gate of the MOS tube is grounded. At this time, the source and drain are cut off, and only the diode is unidirectionally conducted to achieve isolation between the DC converter 20 and the battery 10. The DC converter 20 stops charging the battery 10. At this time, after the starter relay 70 is closed, the battery 10 supplies power to the starter 60 alone, and the DC converter 20 supplies power to the low-voltage load of the vehicle, avoiding the starter 60 pulling down the low-voltage terminal voltage of the DC converter 20 when pulling down the voltage of the battery 10. After the engine speed is dragged to a certain speed by the starter 60, the engine is ignited by fuel injection, and the control of the starter 60 starting the engine is completed. Then, the state of the analog switch 50 is determined according to whether the battery 10 needs to be charged, and then the conduction state of the source and drain of the MOS tube is determined.

[0091] The starting isolation circuit of the starter provided in the embodiment of the present application can not only realize the starting isolation of the starter, but also realize the charging and discharging control of the battery, thereby improving the practicality and safety.

[0092] In addition, an embodiment of the present application also provides a starting isolation device for a starter, including a starting isolation circuit provided by any one of the above embodiments.

[0093] Furthermore, an embodiment of the present application also provides a car, comprising the starting isolation circuit provided by any one of the above embodiments.

[0094] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0095] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A starting isolation circuit for a starter, characterized in that: The starting isolation circuit includes: a battery, a DC converter, a switch structure, a vehicle controller, an analog switch, a starter and a starter relay; the switch structure includes a control end; The battery is connected to the switch structure, and the switch structure is connected to the DC converter; the vehicle controller is connected to the battery and the analog switch respectively, and the analog switch is connected to the control end; The vehicle controller is used to control the starter relay to close and the analog switch to open if it is determined that the engine is started by the starter; The control end is used to control the switch structure to conduct only in one direction when the analog switch is disconnected, so that when the engine is started by the starter, the DC converter stops charging the battery; The vehicle controller is also used to close or open the analog switch according to the power of the battery after completing the starting control of the starter, so that the DC converter charges or does not charge the battery; Wherein, when the analog switch is closed, the vehicle controller also provides the control terminal with a control voltage capable of controlling the switch structure to be closed, so that the DC converter charges the battery; The vehicle controller includes a micro control unit and an amplifier circuit; The micro control unit is connected to the analog switch and the input end of the amplifier circuit respectively, the input end of the amplifier circuit is also connected to the battery, and the output end of the amplifier circuit is connected to the analog switch; The micro control unit is used for controlling the starter relay to close and the analog switch to open if it is determined that the engine is started by the starter; The microcontroller unit is also used to close or open the analog switch according to the power level of the battery after completing the starting control of the starter, so that the DC converter charges or does not charge the battery; The amplifier circuit is used to provide the control terminal with a control voltage capable of controlling the switch structure to be closed when the analog switch is closed, so that the DC converter charges the battery.

2. The starting isolation circuit according to claim 1, characterized in that: The switch structure includes a diode and a switch element, and the switch element includes a first connection end, a second connection end, and a control end; The first connection end is connected to the positive electrode of the diode and the battery, and the second connection end is connected to the negative electrode of the diode and the DC converter; The diode is used to achieve unidirectional conduction from the battery to the DC converter; The control end is used to disconnect the switch element when the analog switch is disconnected, so that when the engine is started by the starter, the DC converter stops charging the battery.

3. The starting isolation circuit according to claim 2, characterized in that: The switch element comprises a MOS tube, the source of the MOS tube is the first connection end, the drain of the MOS tube is the second connection end, and the gate of the MOS tube is the control end; The gate of the MOS tube is used to turn off the MOS tube when the analog switch is disconnected, so that when the engine is started by the starter, the DC converter stops charging the battery.

4. The starting isolation circuit according to claim 1, characterized in that: The amplifier circuit comprises a triode, the base of the triode is the input end of the amplifier circuit, the collector of the triode is the output end of the amplifier circuit, and the emitter of the triode is grounded; The transistor is used to provide the control terminal with a control voltage capable of controlling the switch structure to be closed when the analog switch is closed, so that the DC converter charges the battery.

5. The starting isolation circuit according to claim 4, characterized in that: The amplifying circuit further comprises a capacitor, one end of which is connected to the collector of the transistor, and the other end of which is grounded, and the capacitor is used to filter the control voltage.

6. The starting isolation circuit according to claim 1, characterized in that: The starting isolation circuit also includes a battery monitoring sensor, which is connected to the battery. The battery monitoring sensor is used to monitor the power level of the battery and provide the battery power information to the vehicle controller.

7. A starting isolation device for a starter, characterized in that: The invention comprises a starting isolation circuit as claimed in any one of claims 1 to 6.

8. A car, characterized in that: The automobile comprises a starting isolation circuit as claimed in any one of claims 1 to 6.

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