Protection circuit and circuit protection method used in protection circuit

Abstract

The embodiment of the present invention provides a protection circuit and a circuit protection method applied to the protection circuit, including a starting module, a power-on circuit, a starting circuit, a control module and a motor, wherein the starting module is electrically connected to the control module, the control module is electrically connected to the power-on circuit and the starting circuit respectively, and the starting circuit is electrically connected to the motor. The starting module is used to provide an electrical signal to the control module; the control module is used to output a first high-level signal to the power-on circuit, or output a first low-level signal; the power-on circuit is used to power on the electric working machine, or to power off the electric working machine; the control module is also used to output a second high-level signal to the starting circuit, or output a second low-level signal; the starting circuit is used to start the motor, or shut down the motor. The present invention is used to solve the defect in the prior art that the failure rate of the power system of the excavator is relatively high due to the bad usage habits of users.

Description

Technical Field

[0001] The present invention relates to the technical field of protection circuits, and in particular to a protection circuit and a circuit protection method applied to the protection circuit. Background Art

[0002] Hydraulic excavator is a kind of engineering machinery widely used in urban infrastructure and other construction fields. With the annual increase of national infrastructure construction and the increase of energy demand such as minerals, hydraulic excavator has become a hot engineering machinery. Among them, the power system of electric hydraulic excavator is the power source of the whole excavator. Whether the power system can operate normally directly affects the operation of the whole excavator.

[0003] However, due to the bad usage habits of users, the failure rate of the excavator's power system is relatively high. Therefore, how to make the excavator's power system adapt to the various usage habits of users is a problem that needs to be solved urgently in the industry. Summary of the invention

[0004] The embodiment of the present invention provides a protection circuit and a circuit protection method applied to the protection circuit, so as to solve the defect in the prior art that the failure rate of the power system of the excavator is high due to the bad usage habits of users, and realize adaptation to various usage habits of users.

[0005] An embodiment of the present invention provides a protection circuit, characterized in that it is applied to an electric working machine, the protection circuit comprises: a starting module, a power-on circuit, a starting circuit, a control module and a motor, the starting module is electrically connected to the control module, the control module is electrically connected to the power-on circuit and the starting circuit respectively, and the starting circuit is electrically connected to the motor;

[0006] A start-up module, used to provide an electrical signal to the control module, wherein the electrical signal includes: a first signal and a second signal;

[0007] The control module is used to output a first low-level signal to the power-on circuit, or to receive the first signal and output a first high-level signal to the power-on circuit;

[0008] The power-on circuit is used to receive the first high-level signal to power on the electric working machine, or to receive the first low-level signal to power off the electric working machine;

[0009] The control module is further used to output a second low level signal to the startup circuit, or is further used to receive the second signal and output a second high level signal to the startup circuit;

[0010] The starting circuit is used to receive the second high level signal to start the motor, or receive the second low level signal to shut down the motor.

[0011] According to a protection circuit of one embodiment of the present invention, the power-on circuit comprises: a first relay group and a first fuse;

[0012] A first end of the first relay group is electrically connected to the control module, and a second end of the first relay group is electrically connected to the first fuse.

[0013] According to a protection circuit of an embodiment of the present invention, the protection circuit further comprises: a power supply module and a ground wire, wherein the power supply module is electrically connected to the startup module and is used to supply power to the startup module;

[0014] The first relay group includes: a first relay and a second relay;

[0015] A first end of the coil of the first relay is electrically connected to the control module, a second end of the coil of the first relay is electrically connected to the negative pole of the power module, a first end of the contact of the first relay is electrically connected to the first end of the coil of the second relay, and a second end of the contact of the first relay is electrically connected to the positive pole of the power module;

[0016] The second end of the coil of the second relay is electrically connected to the control module, the first end of the contact of the second relay is electrically connected to the positive pole of the power module, and the second end of the contact of the second relay is electrically connected to the first fuse.

[0017] According to a protection circuit of one embodiment of the present invention, the startup circuit comprises: a second relay group and a third relay group;

[0018] The first end of the second relay group is electrically connected to the starting module, the second end of the second relay group is electrically connected to the motor, the first end of the third relay group is electrically connected to the control module, and the second end of the third relay group is electrically connected to the motor.

[0019] According to the protection circuit of one embodiment of the present invention, the startup circuit further includes: a second fuse, a third fuse and a fourth fuse;

[0020] The second relay group includes: a third relay, and the third relay group includes: a fourth relay and a fifth relay;

[0021] A first end of the coil of the third relay is electrically connected to the start module, a second end of the coil of the third relay is electrically connected to the ground wire, a first end of the contact of the third relay is electrically connected to the second fuse, and a second end of the contact of the third relay is electrically connected to the control module;

[0022] A first end of the coil of the fourth relay is electrically connected to the motor through the third fuse, a second end of the coil of the fourth relay is electrically connected to the control module, a first end of the contact of the fourth relay is electrically connected to the motor, and a second end of the contact of the fourth relay is electrically connected to the ground wire;

[0023] The first end of the coil of the fifth relay is electrically connected to the fourth fuse, the second end of the coil of the fifth relay is electrically connected to the control module, the first end of the contact of the fifth relay is electrically connected to the motor, and the second end of the contact of the fifth relay is electrically connected to the ground wire.

[0024] An embodiment of the present invention further provides a circuit protection method applied to a protection circuit, comprising:

[0025] Acquire an electrical signal provided by the start-up module, wherein the electrical signal includes: a first signal and a second signal;

[0026] When it is determined that the electrical signal is the first signal, the control module is controlled to output a first high level signal to the upper power circuit to power on the electric working machine;

[0027] When the operating signal of the electric operating machine is not detected within a first preset time after the electric operating machine is powered on, the control module is controlled to output a first low-level signal to the power-on circuit to power off the electric operating machine, wherein the operating signal is used to indicate the operating status of the electric operating machine;

[0028] When it is determined that the electrical signal is the second signal, controlling the control module to output a second high level signal to the starting circuit and obtaining the rotation speed of the motor;

[0029] When the rotation speed is greater than a preset value, it is determined that the motor is started successfully; when the rotation speed is less than or equal to the preset value, it is determined that the motor is not started successfully;

[0030] When the second signal is not detected within a second preset time after the motor fails to start, the control module is controlled to output a second low level signal to the starting circuit to turn off the motor.

[0031] According to a circuit protection method of an embodiment of the present invention, when it is determined that the electrical signal is the first signal, controlling the control module to output a first high-level signal to the power circuit to power on the electric working machine includes:

[0032] When it is determined that the electrical signal is the first signal, the control module is controlled to output the first high-level signal to the power-on circuit, so that the coil of the first relay is powered on, the contacts of the first relay are electrically connected, the coil of the second relay is powered on, the contacts of the second relay are electrically connected, and the electric working machine is powered on successfully.

[0033] According to an embodiment of the present invention, a circuit protection method controls the control module to output a first low-level signal to the power-on circuit to power off the electric working machine, including:

[0034] The control module is controlled to output the first low-level signal to the power-on circuit, so that the coil of the first relay and the coil of the second relay are de-energized, the contacts of the first relay and the contacts of the second relay are disconnected, and the electric working machine is successfully de-energized.

[0035] According to a circuit protection method of an embodiment of the present invention, when it is determined that the electrical signal is the second signal, controlling the control module to output a second high level signal to the starting circuit and obtaining the rotation speed of the motor includes:

[0036] When it is determined that the electrical signal is the second signal, the control module is controlled to output the second high-level signal to the starting circuit, so that the coil of the third relay is powered on, the contacts of the third relay are electrically connected, and after the third relay is powered on, the rotation speed of the motor is obtained.

[0037] According to an embodiment of the circuit protection method of the present invention, when the rotation speed is less than or equal to the preset value, after determining that the motor has not started successfully, the method further includes:

[0038] If the second signal is detected within the second preset time, the control module is controlled to output the second high-level signal, so that the coil of the fourth relay is powered on, and the contacts of the fourth relay are electrically connected; and after the third preset time, the control module is controlled to output the second high-level signal, the coil of the fifth relay is powered on, and the contacts of the fifth relay are electrically connected to start the motor, and the second preset time is less than the second preset time.

[0039] The beneficial effects of the present invention are:

[0040] 1. The protection circuit provided in the embodiment of the present invention is applied to an electric working machine, comprising: a starting module, a power-on circuit, a starting circuit, a control module and a motor, wherein the starting module is electrically connected to the control module, the control module is electrically connected to the power-on circuit and the starting circuit respectively, and the starting circuit is electrically connected to the motor; the starting module is used to provide an electrical signal to the control module, and the electrical signal comprises: a first signal and a second signal; the control module is used to receive the first signal, output a first high-level signal to the power-on circuit, and the power-on circuit receives the first high-level signal to power on the electric working machine; the control module is also used to output a first low-level signal to the power-on circuit, and the power-on circuit receives the first low-level signal to power on the electric working machine The operating machinery is powered off; the control module is further used to receive a second signal and output a second high-level signal to the starting circuit; the starting circuit is used to receive the second high-level signal to start the motor; the control module is further used to output a second low-level signal to the starting circuit, and the starting circuit is used to receive the second low-level signal to shut down the motor. It can be seen that the present invention separately controls the power-on of the operating machinery and the starting of the motor through two protection circuits, and separately controls the power-off of the operating machinery and the shut-down of the motor through two protection circuits, so that the electric operating machinery of the present invention can adapt to various usage habits of users, and solves the problem of easy failure of the power system of the electric operating machinery due to improper use by users.

[0041] 2. The circuit protection method applied to the protection circuit of the present invention provided by the present invention obtains the electrical signal provided by the starting module, and the electrical signal includes: a first signal and a second signal; when it is determined that the electrical signal is the first signal, the control module is controlled to output a first high-level signal to the upper power circuit to power on the electric working machine; when the operating signal of the electric working machine is not detected within the first preset time after the electric working machine is powered on, the control module is controlled to output a first low-level signal to the upper power circuit to power off the electric working machine, and the operating signal is used to indicate the operating status of the electric working machine. It can be seen that after the present invention determines that the electric working machine is powered on, but there is no user using the electric working machine, at this time, the present invention uses the power-on circuit to power off the electric working machine, which effectively avoids the occurrence of safety hazards caused by the excavator not running for a long time.

[0042] Furthermore, when it is determined that the electrical signal is the second signal, the control module is controlled to output a second high-level signal to the starting circuit and obtain the rotational speed of the motor; when the rotational speed is greater than a preset value, it is determined that the motor has started successfully, and when the rotational speed is less than or equal to the preset value, it is determined that the motor has not started successfully; when the second signal is not detected within a second preset time after the motor has not started successfully, the control module is controlled to output a second low-level signal to the starting circuit to turn off the motor. It can be seen that the present invention controls the start or shut down of the motor based on parameters such as the rotational speed and duration of the motor, so that the present invention can adapt to various usage habits of users and solves the problem that the power system of the electric working machinery is prone to failure due to improper use by users. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 This is one of the structural schematic diagrams of a protection circuit provided by an embodiment of the present invention;

[0045] Figure 2 This is a second structural schematic diagram of a protection circuit provided by an embodiment of the present invention;

[0046] Figure 3 This is a third structural schematic diagram of a protection circuit provided by an embodiment of the present invention;

[0047] Figure 4 It is a flow chart of a circuit protection method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Combine the following Figures 1 to 3 A protection circuit according to an embodiment of the present invention is described.

[0050] An embodiment of the present invention provides a protection circuit, which is applied to electric working machinery, such as a hydraulic excavator, an electric excavator, an electric hydraulic excavator, etc. The circuit structure of the protection circuit is as follows: Figure 1 As shown, it specifically includes: a starting module 101, a power-on circuit 102, a starting circuit 103, a control module 104 and a motor 105. The starting module 101 is electrically connected to the control module 104, the control module 104 is electrically connected to the power-on circuit 102 and the starting circuit 103 respectively, and the starting circuit 103 is electrically connected to the motor 105.

[0051] The start module 101 is used to provide an electrical signal to the control module 104, and the electrical signal includes: a first signal and a second signal;

[0052] The control module 104 is used to output a first low-level signal to the upper power circuit 102, or to receive a first signal and output a first high-level signal to the upper power circuit 102;

[0053] The power-on circuit 102 is used to receive a first high-level signal to power on the electric working machine, or to receive a first low-level signal to power off the electric working machine;

[0054] The control module 104 is further configured to output a second low level signal to the start-up circuit 103, or is further configured to receive a second signal and output a second high level signal to the start-up circuit 103;

[0055] The start circuit 103 is used to receive the second high level signal to start the motor 105, or receive the second low level signal to stop the motor 105.

[0056] Specifically, the starting module 101 includes: a first starting end and a second starting end, the first starting end and the second starting end are electrically connected to the control module 104 respectively, the first starting end is used to provide a first signal to the control module 104, and the second starting end is used to provide a second signal to the control module 104.

[0057] Among them, the first starting end is the BR output end, and the second starting end is the C end.

[0058] The start-up module 101 further includes: a positive electrode terminal, which is electrically connected to the positive electrode of the power module through a fifth fuse.

[0059] Below, through a number of specific embodiments, and by combining Figure 2 and Figure 3 A specific description of the protection circuit:

[0060] In a specific embodiment, the power-on circuit 102 includes: a first relay group and a first fuse 201 . A first end of the first relay group is electrically connected to the control module 104 , and a second end of the first relay group is electrically connected to the first fuse 201 .

[0061] In a specific embodiment, the protection circuit further includes: a power module and a ground wire, the power module is electrically connected to the start-up module 101, and is used to supply power to the start-up module 101. The first relay group includes: a first relay 202 and a second relay 203; the first end of the coil of the first relay 202 is electrically connected to the control module 104, the second end of the coil of the first relay 202 is electrically connected to the negative pole of the power module, the first end of the contact of the first relay 202 is electrically connected to the first end of the coil of the second relay 203, and the second end of the contact of the first relay 202 is electrically connected to the positive pole of the power module; the second end of the coil of the second relay 203 is electrically connected to the control module 104, the first end of the contact of the second relay 203 is electrically connected to the positive pole of the power module, and the second end of the contact of the second relay 203 is electrically connected to the first fuse 201.

[0062] Specifically, the positive electrode of the power module is electrically connected to the positive electrode terminal of the starting module.

[0063] Specifically, the control module 104 includes: a first control unit 204, a second control unit 205 and a third control unit 206, and a communication electrical connection is established between the first control unit 204, the second control unit 205 and the third control unit 206. The first control unit 204 is electrically connected to the first starting end, and is used to receive the first signal transmitted by the first starting end; the first control unit 204 is also used to control the second control unit 205 to output a first low-level signal; the second control unit 205 is electrically connected to the second end of the coil of the second relay 203, and is used to output a first low-level signal to power off the power-on circuit 102. Specifically, the second control unit 205 outputs the first low-level signal, the coil of the second relay 203 is powered off, and the contacts of the second relay 203 are disconnected. At this time, the power-on circuit 102 is powered off, and the whole vehicle is powered off successfully.

[0064] The first control unit 204 is further used to receive the first signal and control the third control unit 206 to output a first high-level signal; the third control unit 206 is electrically connected to the first end of the coil of the first relay 202, and is used to output a first high-level signal to power on the power-on circuit 102. Specifically, the third control unit 206 outputs the first high-level signal, the coil of the first relay 202 is powered on, the contacts of the first relay 202 are electrically connected, the coil of the second relay 203 is powered on, the contacts of the second relay 203 are electrically connected, and the power-on circuit 102 is powered on. At this time, the vehicle is on a low voltage of 24V.

[0065] In a specific embodiment, the starting circuit 103 includes: a second relay group and a third relay group. A first end of the second relay group is electrically connected to the starting module 101, a second end of the second relay group is electrically connected to the motor 105, a first end of the third relay group is electrically connected to the control module 104, and a second end of the third relay group is electrically connected to the motor 105.

[0066] In a specific embodiment, the start-up circuit 103 further includes: a second fuse 207 , a third fuse 208 and a fourth fuse 209 , the second relay group includes: a third relay 210 , and the third relay group includes: a fourth relay 211 and a fifth relay 212 .

[0067] Among them, the first end of the coil of the third relay 210 is electrically connected to the start module 101, the second end of the coil of the third relay 210 is electrically connected to the ground wire, the first end of the contact of the third relay 210 is electrically connected to the second fuse 207, and the second end of the contact of the third relay 210 is electrically connected to the control module 104. The first end of the coil of the fourth relay 211 is electrically connected to the motor 105 through the third fuse 208, the second end of the coil of the fourth relay 211 is electrically connected to the control module 104, the first end of the contact of the fourth relay 211 is electrically connected to the motor 105, and the second end of the contact of the fourth relay 211 is electrically connected to the ground wire.

[0068] The first end of the coil of the fifth relay 212 is electrically connected to the fourth fuse 209, the second end of the coil of the fifth relay 212 is electrically connected to the control module 104, the first end of the contact of the fifth relay 212 is electrically connected to the motor 105, and the second end of the contact of the fifth relay 212 is electrically connected to the ground wire.

[0069] Specifically, the control module further includes: a fourth control unit 213, a fifth control unit 214 and a sixth control unit 215, and a communication electrical connection is established among the fourth control unit 213, the fifth control unit 214 and the sixth control unit 215. The fourth control unit 213 is electrically connected to the second end of the contact of the third relay 210, and the first end of the coil of the third relay 210 is electrically connected to the second starting end, for receiving the second signal output by the second starting end. The fourth control unit 213 is further used to receive the second signal and control the fifth control unit 214 to output a second high level signal; the fifth control unit 214 is electrically connected to the second end of the coil of the fourth relay 211 and is used to output a second high level signal to power on the fourth relay 211; the fourth control unit 213 is further used to receive the second signal and control the sixth control unit 215 to output a second high level signal; the sixth control unit 215 is electrically connected to the second end of the coil of the fifth relay 212 and is used to output a second high level signal to power on the fifth relay 212; the first end of the contact of the fourth relay 211 and the first end of the contact of the fifth relay 212 are respectively electrically connected to the motor 105 to start the motor 105. The fourth control unit 213 is further used to control the fifth control unit 214 and the sixth control unit 215 to output a second low level signal; the first end of the contact of the fourth relay 211 and the first end of the contact of the fifth relay 212 are respectively electrically connected to the motor 105 to turn off the motor 105.

[0070] Specifically, the protection circuit further includes: a motor controller 216. A first end of the motor controller 216 is electrically connected to a first end of a contact of the fourth relay 211 and a first end of a contact of the fifth relay 212, respectively, and a second end of the motor controller 216 is electrically connected to the motor 105, for controlling starting or shutting down the motor 105.

[0071] Specifically, the protection circuit further includes: a pilot switch 217 and a door touch switch 218. The first end of the pilot switch 217 is electrically connected to the second start end, the second end of the pilot switch 217 is electrically connected to the first end of the door touch switch 218, and the second end of the door touch switch 218 is electrically connected to the first end of the coil of the third relay 210.

[0072] The protection circuit and the circuit protection method applied to the protection circuit provided by the embodiment of the present invention are applied to an electric working machine, comprising: a starting module 101, a power-on circuit 102, a starting circuit 103, a control module 104 and a motor 105, wherein the starting module 101 is electrically connected to the control module 104, the control module 104 is electrically connected to the power-on circuit 102 and the starting circuit 103 respectively, and the starting circuit 103 is electrically connected to the motor 105; the starting module 101 is used to provide an electrical signal to the control module, and the electrical signal includes: a first signal and a second signal; the control module 104 is used to receive the first signal and output a first high-level signal to the power-on circuit 102, and the power-on circuit 102 receives the first high-level signal to power on the electric working machine; the control module 104 is also used to output a first low-level signal to the power-on circuit 102 Signal, the power-on circuit 102 receives the first low-level signal to cut off the power of the electric working machine; the control module 104 is also used to receive the second signal and output a second high-level signal to the starting circuit 103; the starting circuit 103 is used to receive the second high-level signal to start the motor 105; the control module 104 is also used to output a second low-level signal to the starting circuit 103, and the starting circuit 103 is used to receive the second low-level signal to shut down the motor 105. It can be seen that the present invention controls the power-on of the working machine and the starting of the motor 105 separately through two protection circuits, and controls the power-off of the working machine and the shut-down of the motor 105 separately through two protection circuits, so that the electric working machine of the present invention can adapt to various usage habits of users, and solves the problem that the power system of the electric working machine is prone to failure due to improper use by users.

[0073] The circuit protection method applied to the protection circuit of the present invention is described below. For the specific implementation of the above protection circuit, please refer to the protection circuit part. The repeated parts will not be repeated. Figure 4 The method of the invention is described. It should be noted that the specific implementation of the method is not limited to Figure 4 Here is an example to illustrate the specific implementation process of the method:

[0074] Step 401 , obtaining an electrical signal provided by the starting module 101 .

[0075] The electrical signal includes: a first signal and a second signal.

[0076] Step 402 , when it is determined that the electric signal is the first signal, the control module 104 is controlled to output a first high level signal to the power-on circuit 102 to power on the electric working machine.

[0077] In a specific embodiment, when it is determined that the electrical signal is the first signal, the control module 104 outputs a first high-level signal to the upper power circuit 102, so that the coil of the first relay 202 is powered on, the contacts of the first relay 202 are electrically connected, the coil of the second relay 203 is powered on, the contacts of the second relay 203 are electrically connected, and the electric working machine is powered on successfully.

[0078] Step 403 , when no operating signal of the electric working machine is detected within a first preset time after the electric working machine is powered on, the control module 104 is controlled to output a first low level signal to the power-up circuit 102 to power off the electric working machine.

[0079] Among them, the operating signal is used to indicate the operating status of the electric operating machinery.

[0080] In a specific embodiment, the control module 104 outputs a first low-level signal to the upper power circuit 102, so that the coil of the first relay 202 and the coil of the second relay 203 are de-energized, the contacts of the first relay 202 and the contacts of the second relay 203 are disconnected, and the electric working machine is successfully de-energized.

[0081] The present invention adopts a power-on circuit to power on the entire vehicle, but within the first preset time period after power-on, if no user uses the electric excavator, the electric excavator is powered off, effectively avoiding the occurrence of safety hazards caused by the excavator not being in operation for a long time.

[0082] Step 404 , when it is determined that the electrical signal is the second signal, the control module 104 is controlled to output a second high level signal to the start circuit 103 , and the rotation speed of the motor 105 is obtained.

[0083] In a specific embodiment, when it is determined that the electrical signal is the second signal, the control module 104 outputs a second high-level signal to the starting circuit, so that the coil of the third relay 210 is powered on, the contacts of the third relay 210 are electrically connected, and after the third relay 210 is powered on, the speed of the motor is obtained.

[0084] Specifically, when the pilot switch 217 and the door touch switch 218 are closed, the coil of the third relay 210 is powered on, and the contacts of the third relay 210 are electrically connected. At this time, the fourth control unit 213 inputs a high level signal corresponding to the second signal. After determining that the fourth control unit 213 inputs a high level signal corresponding to the second signal, the speed of the motor 105 is obtained.

[0085] Step 405 , when the rotation speed is greater than a preset value, it is determined that the motor 105 is started successfully; when the rotation speed is less than or equal to the preset value, it is determined that the motor 105 is not started successfully.

[0086] In a specific embodiment, if a second signal is detected within a second preset time, the control module 104 outputs a second high-level signal to power on the coil of the fourth relay 211 and electrically connect the contacts of the fourth relay 211, and after a third preset time, the control module 104 outputs a second high-level signal to power on the coil of the fifth relay 212 and electrically connect the contacts of the fifth relay 212 to start the motor 105, and the second preset time is less than the second preset time.

[0087] Specifically, when the rotation speed is greater than the preset value, it is determined that the motor 105 is in the starting state. At this time, the fourth control unit 213 controls the fifth control unit 214 not to output any electrical signal, and the starting circuit 103 is in the power-off state. After determining that the motor 105 is started, the present invention puts the starting circuit 103 in the power-off state, effectively avoiding repeated starting of the excavator. In addition, after determining that the motor 105 is started, the second signal is automatically filtered out to avoid repeated starting of the motor 105.

[0088] Step 406 , when the second signal is not detected within the second preset time after the motor 105 fails to start, the control module 104 is controlled to output a second low level signal to the starting circuit 103 to turn off the motor 105 .

[0089] Specifically, when the motor 105 needs to be turned off, the fourth control unit 213 controls the fifth control unit 214 and the sixth control unit 215 to make the fifth control unit 214 and the sixth control unit 215 output the second low level signal at the same time, and the motor 105 stops running.

[0090] The circuit protection method applied to the protection circuit provided in the embodiment of the present invention obtains the electrical signal provided by the starting module 101, and the electrical signal includes: a first signal and a second signal; when it is determined that the electrical signal is the first signal, the control module 104 is controlled to output a first high-level signal to the power-on circuit 102 to power on the electric working machine; when the operating signal of the electric working machine is not detected within the first preset time after the electric working machine is powered on, the control module 104 is controlled to output a first low-level signal to the power-on circuit 102 to power off the electric working machine, and the operating signal is used to indicate the operating status of the electric working machine. It can be seen that after the present invention determines that the electric working machine is powered on, but there is no user using the electric working machine, at this time, the present invention uses the power-on circuit to power off the electric working machine, which effectively avoids the occurrence of safety hazards caused by the excavator not being in operation for a long time.

[0091] Furthermore, when it is determined that the electrical signal is the second signal, the control module 104 is controlled to output a second high-level signal to the starting circuit 103 and obtain the rotational speed of the motor 105; when the rotational speed is greater than the preset value, it is determined that the motor 105 has started successfully, and when the rotational speed is less than or equal to the preset value, it is determined that the motor 105 has not started successfully; when the second signal is not detected within a second preset time after the motor 105 has not started successfully, the control module 104 is controlled to output a second low-level signal to the starting circuit 103 to turn off the motor 105. It can be seen that the present invention controls the start or shut down of the motor 105 based on parameters such as the rotational speed and duration of the motor 105, so that the present invention can adapt to various usage habits of users and solve the problem of easy failure of the power system of the electric working machinery due to improper use by the user.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protection circuit, characterized in that: Applied to electric working machinery, the protection circuit includes: a starting module, a power-on circuit, a starting circuit, a control module and a motor, the starting module is electrically connected to the control module, the control module is electrically connected to the power-on circuit and the starting circuit respectively, and the starting circuit is electrically connected to the motor; A start-up module, used to provide an electrical signal to the control module, wherein the electrical signal includes: a first signal and a second signal; The control module is used to output a first low-level signal to the power-on circuit, or to receive the first signal and output a first high-level signal to the power-on circuit; The power-on circuit is used to receive the first high-level signal to power on the electric working machine, or to receive the first low-level signal to power off the electric working machine; The control module is further used to output a second low level signal to the startup circuit, or is further used to receive the second signal and output a second high level signal to the startup circuit; The starting circuit is used to receive the second high level signal to start the motor, or receive the second low level signal to shut down the motor; The power-on circuit comprises: a first relay group and a first fuse; A first end of the first relay group is electrically connected to the control module, and a second end of the first relay group is electrically connected to the first fuse; The protection circuit further includes: a power module and a ground wire, wherein the power module is electrically connected to the startup module and is used to supply power to the startup module; The first relay group includes: a first relay and a second relay; A first end of the coil of the first relay is electrically connected to the control module, a second end of the coil of the first relay is electrically connected to the negative pole of the power module, a first end of the contact of the first relay is electrically connected to the first end of the coil of the second relay, and a second end of the contact of the first relay is electrically connected to the positive pole of the power module; The second end of the coil of the second relay is electrically connected to the control module, the first end of the contact of the second relay is electrically connected to the positive electrode of the power module, and the second end of the contact of the second relay is electrically connected to the first fuse; The starting circuit comprises: a second relay group and a third relay group; The first end of the second relay group is electrically connected to the starting module, the second end of the second relay group is electrically connected to the motor, the first end of the third relay group is electrically connected to the control module, and the second end of the third relay group is electrically connected to the motor; The startup circuit also includes: a second fuse, a third fuse and a fourth fuse; The second relay group includes: a third relay, and the third relay group includes: a fourth relay and a fifth relay; A first end of the coil of the third relay is electrically connected to the start module, a second end of the coil of the third relay is electrically connected to the ground wire, a first end of the contact of the third relay is electrically connected to the second fuse, and a second end of the contact of the third relay is electrically connected to the control module; A first end of the coil of the fourth relay is electrically connected to the motor through the third fuse, a second end of the coil of the fourth relay is electrically connected to the control module, a first end of the contact of the fourth relay is electrically connected to the motor, and a second end of the contact of the fourth relay is electrically connected to the ground wire; The first end of the coil of the fifth relay is electrically connected to the fourth fuse, the second end of the coil of the fifth relay is electrically connected to the control module, the first end of the contact of the fifth relay is electrically connected to the motor, and the second end of the contact of the fifth relay is electrically connected to the ground wire.

2. A circuit protection method applied to the protection circuit according to claim 1, characterized in that: include: Acquire an electrical signal provided by the start-up module, wherein the electrical signal includes: a first signal and a second signal; When it is determined that the electrical signal is the first signal, the control module is controlled to output a first high level signal to the upper power circuit to power on the electric working machine; When the operating signal of the electric operating machine is not detected within a first preset time after the electric operating machine is powered on, the control module is controlled to output a first low-level signal to the power-on circuit to power off the electric operating machine, wherein the operating signal is used to indicate the operating status of the electric operating machine; When it is determined that the electrical signal is the second signal, controlling the control module to output a second high level signal to the starting circuit and obtaining the rotation speed of the motor; When the rotation speed is greater than a preset value, it is determined that the motor is started successfully, and when the rotation speed is less than or equal to the preset value, it is determined that the motor is not started successfully; When the second signal is not detected within a second preset time after the motor fails to start, the control module is controlled to output a second low level signal to the starting circuit to turn off the motor.

3. The circuit protection method according to claim 2, characterized in that: When it is determined that the electrical signal is the first signal, controlling the control module to output a first high level signal to the power circuit to power on the electric working machine includes: When it is determined that the electrical signal is the first signal, the control module is controlled to output the first high-level signal to the power-on circuit, so that the coil of the first relay is powered on, the contacts of the first relay are electrically connected, the coil of the second relay is powered on, the contacts of the second relay are electrically connected, and the electric working machine is powered on successfully.

4. The circuit protection method according to claim 2, characterized in that: Controlling the control module to output a first low-level signal to the power-on circuit to power off the electric working machine includes: The control module is controlled to output the first low-level signal to the power-on circuit, so that the coil of the first relay and the coil of the second relay are de-energized, the contacts of the first relay and the contacts of the second relay are disconnected, and the electric working machine is successfully de-energized.

5. The circuit protection method according to claim 3 or 4, characterized in that: When it is determined that the electrical signal is the second signal, controlling the control module to output a second high level signal to the starting circuit and obtaining the rotation speed of the motor includes: When it is determined that the electrical signal is the second signal, the control module is controlled to output the second high-level signal to the starting circuit, so that the coil of the third relay is powered on, the contacts of the third relay are electrically connected, and after the third relay is powered on, the rotation speed of the motor is obtained.

6. The circuit protection method according to claim 3 or 4, characterized in that: When the rotation speed is less than or equal to the preset value, after determining that the motor has not started successfully, the method further includes: If the second signal is detected within the second preset time, the control module is controlled to output the second high-level signal, so that the coil of the fourth relay is powered on, and the contacts of the fourth relay are electrically connected; and after the third preset time, the control module is controlled to output the second high-level signal, the coil of the fifth relay is powered on, and the contacts of the fifth relay are electrically connected to start the motor, and the second preset time is less than the third preset time.

Images