阅读说明：本技术 烟火式安全开关 (Pyrotechnic safety switch ) 是由 丁赟 梁朝升 侯范伟 于 2019-10-16 设计创作，主要内容包括：本发明涉及烟火式安全开关装置领域,尤其涉及烟火式安全开关铜排以及使用该铜排的烟火式安全开关。所述铜排中央为切断连接部,该切断连接部一侧的铜排上设有合金电阻部,该合金电阻部两端的铜排侧面上均设有采样插针,实现动力电池输出主回路电流检测,并在动力电池出现短路大电流时快速、可靠的切断主回路铜排,从而实现动力电池短路保护。(The invention relates to the field of pyrotechnic safety switch devices, in particular to a pyrotechnic safety switch copper bar and a pyrotechnic safety switch using the copper bar. Copper bar central authorities are for cutting off connecting portion, are equipped with alloy resistance portion on the copper bar of this cutting off connecting portion one side, all are equipped with the sampling contact pin on the copper bar side at this alloy resistance portion both ends, realize power battery output major loop current detection to quick, reliable major loop copper bar cuts off when power battery appears the short circuit heavy current, thereby realize power battery short circuit protection.)

1. Copper bar for pyrotechnic safety switch, including the copper bar, its characterized in that, copper bar central authorities are for cutting off connecting portion, are equipped with alloy resistance portion on the copper bar of this cutting off connecting portion one side, all are equipped with the sampling contact pin on the copper bar side at this alloy resistance portion both ends.

2. The copper bar for the pyrotechnic safety switch as claimed in claim 1, wherein the contact pin is connected with a PCB control board.

3. Pyrotechnic safety switch, characterized in that it comprises a copper bar according to any of claims 1-2, and also comprises a housing; the cavity in the center of the shell sequentially comprises an igniter, a piston and a copper bar from top to bottom; the cutting connecting part on the copper bar is positioned right below the cutting end of the piston; a control panel accommodating cavity is formed in the shell on one side of the cavity.

4. The pyrotechnic safety switch as claimed in claim 3 wherein the igniter is provided with a mounting step at the bottom end thereof, and slots are provided at both sides of the mounting step; and the two ends of the inner side wall of the top end of the piston are provided with insertion blocks matched with the insertion grooves for use.

5. The pyrotechnic safety switch of claim 3 wherein the cutting end of the piston is spaced from the copper bar.

6. The pyrotechnic safety switch as claimed in claim 3 wherein the igniter tip is provided with a signal input pin.

7. The detection system with the pyrotechnic safety switch is characterized by comprising a micro control unit, wherein the micro control unit is respectively connected with a high-voltage main loop, a power supply unit, an optical coupler and an isolation CAN transceiver; the power supply unit comprises a voltage stabilizer, an isolation module, a low-voltage auxiliary power supply, an igniter switch and a switch which are sequentially connected in series; the switch is connected with the optocoupler; and the micro control unit is connected with a copper bar of the pyrotechnic safety switch on the high-voltage main loop.

8. The detection method of the detection system with the pyrotechnic safety switch comprises the following steps: the method is characterized by comprising the following steps:

step 1: a copper bar on the pyrotechnic safety switch detects the current signal of the high-voltage main loop;

step 2: when the detected current is less than 1.5 times of the rated current, entering step 3;

and step 3: the CAN message displays the current value, the alarm is 0, and the step 1 is repeated;

and 4, step 4: when the current value is detected to exceed the rated current by 1.5 times but not exceed the rated current by 3 times, the step 7 is carried out, otherwise, the step 5 is carried out;

and 5: when the current value is detected to exceed 3 times of the rated current and not exceed 5 times of the rated current, the step 8 is carried out, otherwise, the step 6 is carried out;

step 6: when the current value is detected to exceed 5 times of the rated current, the step 9 is carried out;

and 7: sending a level 1 alarm message by the CAN message, displaying the current value, and repeating the step 1;

and 8: sending a 2-level alarm message by the CAN message, displaying the current value, and repeating the step 1;

and step 9: and the CAN message sends a 3-level alarm message, displays the current value and cuts off the high-voltage main loop.

Technical Field

The invention relates to the field of pyrotechnic safety switch devices, in particular to a pyrotechnic safety switch copper bar and a pyrotechnic safety switch with the copper bar.

Background

Two modes are generally used for detecting the main loop current of the power battery of the new energy electric automobile, one mode is a Hall type current sensor, the other mode is SHUNT SHUNT resistance detection, and when the short-circuit current of the power battery occurs, the three cutting schemes are generally ①, high-voltage relay is cut off with load (can be regarded as a recoverable cutting device), ② high-voltage fuse is fused (is fused once), and ③ pyrotechnic safety switch is cut off (is broken once).

At present, except that the fuse is self-heating fusing to achieve the function of cutting off a main loop, other breaking modes are the same from the aspect of control logic, namely: the Hall current sensor or the SHUNT SHUNT resistor detects abnormal large current, the information is fed back to a BMS (battery management system) through CAN communication, and then the BMS sends a signal to a related controllable breaking device through processing, so that a main loop is cut off, but the process has long reaction time and is not sensitive enough; and the circuit is longer, receives external signal interference easily and the risk that the signal transmission circuit damage fracture brought.

At present, a safety breaking system of a power battery is mostly in a mode of adding a fuse to a relay, namely, a high-voltage relay and the fuse are connected in series on a main loop, and when an electric vehicle works normally, the high-voltage relay is responsible for an output switch of the power battery, namely, the circuit is closed and broken; when short-circuit current occurs in a main loop of the power battery, the fuse is rapidly heated and fused within a certain time, and the BMS sends a signal to the high-voltage relay based on two modes at the moment to cut off the main loop, wherein one mode is that abnormal current is found by current detection and fed back to the BMS, and the other mode is that high-voltage sampling signals at two ends of the fuse are fed back to the BMS; the greatest risk points in the above model are: the fuse does not fuse for a long time when the low power transships and leads to the adhesion of high voltage relay contact, and high voltage relay can't divide absolutely to fuse protect function is inefficacy, leads to danger such as personnel's electric shock easily when the fuse is changed.

At present, the series mode of a pyrotechnic safety switch and a high-voltage relay of a newly developed product replaces a fuse, when the pyrotechnic safety switch receives a BMS signal, an igniter is detonated quickly to push a piston to cut off a copper bar, a breaking circuit is arranged, the response speed of the breaking circuit is within 1ms, the high-voltage relay can be protected effectively by the quick breaking circuit to prevent contact adhesion, the breaking of a main circuit in the mode is controllable, but the signal transmission process is that a Hall current sensor or a SHUNT SHUNT resistor detects abnormal short-circuit current and feeds the abnormal short-circuit current back to the BMS for diagnosis and judgment, then the BMS sends a signal to trigger the pyrotechnic safety switch igniter to break the circuit, the response speed of the pyrotechnic safety switch per se is 1ms, but the signal transmission may take 2ms, so that the effect of quick response is lost, and in an extreme case, if the signal is subjected to malfunction caused by external interference, or the physical damage and the breakage of the signal wire can not transmit signals, so that the pyrotechnic safety switch can not respond, and the like.

Disclosure of Invention

The invention aims to realize the detection of the current of the main loop output by the power battery and quickly and reliably cut off the copper bar of the main loop when the power battery has a short circuit and a large current, thereby realizing the short circuit protection of the power battery.

Copper bar for pyrotechnic safety switch, including the copper bar, copper bar central authorities are the cut-off connection portion, should cut off and be equipped with alloy resistance portion on the copper bar of connecting portion one side, all are equipped with the sampling contact pin on the copper bar side at this alloy resistance portion both ends.

The contact pin is connected with the PCB control board.

The pyrotechnic safety switch comprises a shell; the cavity in the center of the shell sequentially comprises an igniter, a piston and a copper bar from top to bottom; the cutting connecting part on the copper bar is positioned right below the cutting end of the piston; a control panel accommodating cavity is formed in the shell on one side of the cavity.

The bottom end of the igniter is provided with a mounting step, and two sides of the mounting step are provided with slots; and the two ends of the inner side wall of the top end of the piston are provided with insertion blocks matched with the insertion grooves for use.

And a space is reserved between the cutting end of the piston and the copper bar.

And a signal input contact pin is arranged at the top end of the igniter.

The detection system with the pyrotechnic safety switch comprises a micro control unit, wherein the micro control unit is respectively connected with a high-voltage main loop, a power supply unit, an optical coupler and an isolation CAN transceiver; the power supply unit comprises a voltage stabilizer, an isolation module, a low-voltage auxiliary power supply, an igniter switch and a switch which are sequentially connected in series; the switch is connected with the optocoupler; the isolated CAN transceiver is connected with the CAN; and the micro control unit is connected with a copper bar of the pyrotechnic safety switch on the high-voltage main loop.

The detection method of the detection system with the pyrotechnic safety switch comprises the following steps: comprises the following steps:

step 1: a copper bar on the pyrotechnic safety switch detects the current signal of the high-voltage main loop;

step 2: when the detected current is less than 1.5 times of the rated current, entering step 3;

and step 3: the CAN message displays the current value, the alarm is 0, and the step 1 is repeated;

and 4, step 4: when the current value is detected to exceed the rated current by 1.5 times but not exceed the rated current by 3 times, the step 7 is carried out, otherwise, the step 5 is carried out;

and 5: when the current value is detected to exceed 3 times of the rated current and not exceed 5 times of the rated current, the step 8 is carried out, otherwise, the step 6 is carried out;

step 6: when the current value is detected to exceed 5 times of the rated current, the step 9 is carried out;

and 7: sending a level 1 alarm message by the CAN message, displaying the current value, and repeating the step 1;

and 8: sending a 2-level alarm message by the CAN message, displaying the current value, and repeating the step 1;

and step 9: and the CAN message sends a 3-level alarm message, displays the current value and cuts off the high-voltage main loop.

The invention has the beneficial effects that: the invention combines the existing smoke-fire type safety switch, the main overcurrent device is the copper bar, and the working principle is as follows: the igniter receives the low-voltage signal and quickly detonates to push the piston to cut off the copper bar, so that the circuit is broken. As for the SHUNT SHUNT resistor for current detection, the matrix can be also regarded as a copper bar, and only the middle part is a precisely calibrated alloy resistor. The invention combines the copper bar and the SHUNT SHUNT resistor in the pyrotechnic safety switch, so that the current detection and the pyrotechnic safety switch are integrated. The SHUNT SHUNT resistor and the pyrotechnic safety switch are integrated and developed to realize current detection and reliable breaking integration; the SHUNT SHUNT resistor is used as a current sampling substrate, a PCB control board is added, software design is carried out, current detection, CAN communication reporting to a BMS, synchronous signaling to the pyrotechnic safety switch is realized, the pyrotechnic safety switch is driven to act, the response is rapid, and the operation is sensitive; the current detection is realized, the pyrotechnic safety switch is quickly fed back and driven, the signal transmission line is short, safety and reliability are realized, and the risks caused by external signal interference and damage and fracture of the signal transmission line can be eliminated. The invention integrates the SHUNT SHUNT resistor and the pyrotechnic safety switch into a whole so as to achieve relatively independent self-current detection and driving of the safety switch.

Drawings

The foregoing and other objects, features, and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings.

Wherein: FIG. 1 is a schematic view of the pyrotechnic safety switch of the present invention;

FIG. 2 is a schematic side sectional view of the pyrotechnic safety switch of the present invention;

FIG. 3 is a schematic structural diagram of the current detection principle of the present invention;

FIG. 4 is a schematic diagram of a current detection process according to the present invention;

in the attached drawing, 1 is the copper bar, 2 is cutting off connecting portion, 3 is alloy resistance portion, 4 is the sampling contact pin, 5 is the PCB control panel, 6 is the casing, 7 is some firearm, 8 is the piston, 10 holds the chamber for the control panel, 11 is the installation step, 12 is the slot, 13 is the inserted block, 14 is the interval, 15 is the signal input contact pin, 16 is little the control unit, 17 is the major loop, 19 is the opto-coupler, 20 is the isolation CAN transceiver, 21 is the stabiliser, 22 is the isolation module, 23 is low voltage auxiliary power supply, 25 is some firearm switches, 26 is the switch.

Detailed Description

Referring to fig. 1-3, a copper bar for a pyrotechnic safety switch comprises a copper bar 1, wherein a cut-off connection portion 2 is arranged in the center of the copper bar, an alloy resistance portion 3 is arranged on the copper bar on one side of the cut-off connection portion, and sampling contact pins 4 are arranged on the side faces of the copper bar at the two ends of the alloy resistance portion. The cutting connecting parts are connected with two ends of the copper bar, and the thickness of the cutting connecting parts is thinner than that of other parts of the copper bar, so that the cutting is convenient; alloy resistance portion has on the copper bar of cutting off connecting portion one side to the measuring current detects more sensitively, and sets up in the side of the copper bar of accurate resistance both sides and adopts the contact pin, conveniently connects PCB control panel 5.

The contact pin is connected with the PCB control board. The contact pin is connected with the control board, the contact pin feeds the detected current signal back to the control board, and the signal which needs to cut off the connection part is selected to be generated or not through the analysis of the control board.

The pyrotechnic safety switch comprises a shell 6; the cavity in the center of the shell sequentially comprises an igniter 7, a piston 8 and a copper bar from top to bottom; the cutting connecting part on the copper bar is positioned right below the cutting end of the piston; a control panel accommodating cavity 10 is arranged in the shell on one side of the cavity. The copper bar with alloy resistance portion is adopted, the contact pins on two sides of the alloy resistance portion transmit detected current signals to the PCB control board in the containing cavity, when short-circuit current is detected, the PCB control board sends low-voltage signals to the igniter, the igniter receives the low-voltage signals and detonates rapidly to push the piston to cut off the copper bar, and therefore a circuit is cut off. The two ends of the copper bar extend out of the shell and are connected with the main circuit, the contact pins on the copper bar are sampling points, and voltage drop is generated at the two ends after current flows through the precision resistor and is led into the control panel through the two contact pins.

The bottom end of the igniter is provided with a mounting step 11, and two sides of the mounting step are provided with slots 12; and the two ends of the inner side wall of the top end of the piston are provided with insertion blocks 13 matched with the insertion grooves for use. Piston top is the U-shaped structure, and installs in installation step both sides through the mode of pegging graft at both ends, like this when some firearm ignition explodes the back, piston and installation step can the quickly separating to the U-shaped structure remains to explode the space, and the impact force is bigger, and the explosion copper bar can cut off fast.

And a space 14 is formed between the cutting end of the piston and the copper bar. The distance is remained, so that the piston obtains an accelerating space and the cutting force is larger.

The igniter tip is provided with a signal input pin 15 (here the signal input pin is connected to F1).

The detection system with the pyrotechnic safety switch comprises a micro control unit 16, wherein the micro control unit is respectively connected with a high-voltage main loop 17, a power supply unit, an optical coupler 19 and an isolation CAN transceiver 20; the power supply unit comprises a voltage stabilizer 21 (the LDO in fig. 3 is a linear voltage stabilizer (or a linear transformer), which is connected in series in sequence, mainly converts an external power supply such as 12Vdc input into 5V or 3.3V output to supply power to an MCU (chip)), an isolation module 22, a low-voltage auxiliary power supply 23, an igniter switch 25 and a switch 26; the switch is connected with the optocoupler; the isolated CAN transceiver is connected with the CAN; and the micro control unit is connected with a copper bar of the pyrotechnic safety switch on the high-voltage main loop. The micro control unit (MM9Z1J638) is internally provided with a CAN controller, so that the CAN bus CAN be communicated only by externally accessing an isolated CAN transceiver. When the micro control unit detects a normal current range (0A-500A), the CAN message displays the current value and gives an alarm of 0; when the current value exceeds 1.5 times of the rated current, the CAN message sends a level 1 alarm message and displays the current value; when the current value exceeds 3 times of the rated current value, the CAN message sends a 2-level alarm message and displays the current value; when the current value exceeds the rated current value by 5 times, the CAN message sends a 3-level alarm message and displays the current value; when a 3-level alarm is achieved, the self-checking safety switch controller (the self-checking safety switch controller outputs power and high voltage common ground after low-voltage power supply passes through the isolation power module and provides power for the MCU, the MCU adopts Freescale MM9Z1J638), an electronic fuse tube (the electronic fuse tube is equivalent to a circuit switch, and the circuit is conducted) can be opened inside, the micro control unit drives the optocoupler to open the MOS, so that when F1 passes through a certain current value, gas inside the igniter expands to cause a copper bar in a high-voltage main loop to be twisted off by an expansive force, and the high-voltage main loop is broken; thereby ensuring the safety of the load of the main circuit and the unsafe factors brought to the vehicle when the load is in failure.

The detection method with the pyrotechnic safety switch comprises the following steps: comprises the following steps:

step 1: a copper bar on the pyrotechnic safety switch detects the current signal of the high-voltage main loop;

step 2: when the detected current is less than 1.5 times of the rated current (when the normal current range is 0A-500A), entering the step 3;

and step 3: the CAN message displays the current value, the alarm is 0, and the step 1 is repeated;

and 4, step 4: when the current value is detected to exceed the rated current by 1.5 times but not exceed the rated current by 3 times, the step 7 is carried out, otherwise, the step 5 is carried out;

and 5: when the current value is detected to exceed 3 times of the rated current and not exceed 5 times of the rated current, the step 8 is carried out, otherwise, the step 6 is carried out;

step 6: when the current value is detected to exceed 5 times of the rated current, the step 9 is carried out;

and 7: sending a level 1 alarm message by the CAN message, displaying the current value, and repeating the step 1;

and 8: sending a 2-level alarm message by the CAN message, displaying the current value, and repeating the step 1;

and step 9: the CAN message sends out a 3-level alarm message and displays the current value; meanwhile, an electronic fuse tube can be opened inside the self-checking safety switch controller, the micro control unit drives the optocoupler to open the MOS, so that F1 is electrified, the igniter ignites to enable a copper bar in the high-voltage main circuit to be twisted off by expansion force, and the high-voltage main circuit is broken. The micro control unit (MM9Z1J638) is internally provided with a CAN controller, so that the CAN bus CAN be communicated only by externally accessing an isolated CAN transceiver. When the micro control unit detects a normal current range (0A-500A), the CAN message displays the current value and gives an alarm of 0; when the current value exceeds 1.5 times of the rated current, the CAN message sends a level 1 alarm message and displays the current value; when the current value exceeds 3 times of the rated current value, the CAN message sends a 2-level alarm message and displays the current value; when the current value exceeds the rated current value by 5 times, the CAN message sends a 3-level alarm message and displays the current value; when a 3-level alarm is achieved, the self-checking safety switch controller (the self-checking safety switch controller outputs power after low-voltage power supply passes through the isolation power module and supplies power to the MCU together with high voltage and high voltage (the self-checking safety switch comprises all electronic devices on the whole low-voltage control panel) and (the MCU adopts Freescale MM9Z1J638) internally opens the electronic fuse tube (after the electronic fuse tube is opened, the MUC can be electrically started for subsequent operation), and the micro control unit drives the optical coupler to open the MOS so that F1 passes through a certain current value, thereby ensuring the safety of a main loop load and unsafe factors brought to a vehicle when the load is in fault.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiment according to the present invention are within the scope of the present invention.