JP2021197743A - Discharge device - Google Patents

Abstract

To prevent erosion of a contact point when discharging electric charge of a smoothing capacitor.SOLUTION: A rapid discharge device 40 discharging electric charge of a smoothing capacitor 42 smoothing an electric voltage between a pair of the power lines transferring electric power to an inverter 70 activated during travel of a vehicle 10 comprises: a discharge part 41 in parallel with the smoothing capacitor 42; and a collision detection switch 50 which supplies a trigger current on the basis of an electric potential difference of the pair of the power lines. The discharge part 41 includes: a self hold switch part (relays 43, 46) which brings the pair of the power lines into a conductive state by the trigger current and keeps the conductive state without the trigger current; and a first resistance part (resistance 45, 47, exciting coil of the relays 43, 46) consuming electric power when the self hold switch part is in the conductive state. The collision detection switch 50 supplies the self hold switch part with the trigger current when active force of collision makes a contact point be in the conductive state. A second resistance part (resistance 44, exciting coil of a relay 43) suppressing the trigger current is also provided.SELECTED DRAWING: Figure 1

Description

This disclosure relates to a discharge device, in particular, to discharge the charge stored in a capacitor provided between power line pairs that send DC power to equipment operating while the vehicle is running and smoothes the voltage between the power line pairs. Regarding the discharge device.

In a vehicle using high voltage power, a capacitor for smoothing the voltage between the power line pairs may be provided between the power line pairs from the high voltage battery to the inverter for driving the motor. When such a vehicle causes a collision, it is necessary to pay attention to the electric charge remaining in the capacitor in the accident processing such as rescue of the occupants of the vehicle.

Conventionally, there has been a discharge switch for a vehicle in which the movable contact is normally held in the off position by a magnet, while the movable contact is moved to the on position by a spring when the vehicle collides. For example, see Patent Document 1). When this discharge switch is turned on due to a vehicle collision, both ends of the capacitor are short-circuited and the capacitor is discharged.

Japanese Unexamined Patent Publication No. 2014-204637

In this discharge switch, it is necessary to pass a short-circuit current through the discharge switch in order to discharge the capacitor in a short time when an inertial force is generated in the movable contact due to a vehicle collision. Therefore, the short-circuit current becomes a large current, an arc discharge occurs at the contact of the discharge switch, and the contact may be melted.

This disclosure has been made to solve the above-mentioned problems, and an object thereof is to provide a discharge device capable of preventing contact damage when discharging the charge of a capacitor. ..

The discharge device according to this disclosure is a discharge device for discharging the electric charge stored in a capacitor provided between power line pairs that send DC power to a device that operates while the vehicle is running and that smoothes the voltage between the power line pairs. It is a device and includes a discharge unit electrically connected in parallel with a capacitor and a collision detection switch that supplies a trigger current using a potential difference between power line pairs. The discharge unit switches from a non-conducting state to a conducting state by the trigger current supplied from the collision detection switch, and maintains the conducting state even when the trigger current disappears when the trigger current switches to the conducting state. It includes a switch unit and a first resistance unit that consumes electric power that passes when the self-holding switch unit is in a conductive state. The collision detection switch supplies a trigger current to the self-holding switch unit by switching from the non-conducting state to the conducting state by contacting the contacts due to the force acting by the collision of the vehicle. The discharge device is provided in the path through which the trigger current flows, and further includes a second resistance portion that suppresses the trigger current.

According to such disclosure, when a vehicle collides, the collision detection switch is switched to the conduction state by contacting the contacts, and the trigger current flows to the self-holding switch section, but the trigger current is suppressed by the second resistance section. As a result, the trigger current flowing through the contact does not become excessive, so that the generation of arc discharge is suppressed and the contact can be prevented from melting. Further, even if the self-holding switch portion is switched to the conductive state and the trigger current disappears, the conductive state is maintained, so that the charge stored in the capacitor is consumed in the first resistance portion. As a result, it is possible to prevent the contacts from being melted when the electric charge of the capacitor is discharged.

According to this disclosure, it is possible to provide a discharge device capable of preventing contact damage when discharging the charge of a capacitor.

It is a figure which shows the outline of the structure of the vehicle which concerns on 1st Embodiment. It is a figure which shows the change of the voltage Vc of the smoothing capacitor in this embodiment. It is a figure which shows the change of the discharge current Ic of the smoothing capacitor in this embodiment. It is a figure which shows the outline of the structure of the vehicle which concerns on 2nd Embodiment.

Hereinafter, embodiments of this disclosure will be described with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Their names and functions are the same. Therefore, detailed explanations about them will not be repeated.

[First Embodiment]
FIG. 1 is a diagram showing an outline of the configuration of the vehicle 10 according to the first embodiment. With reference to FIG. 1, vehicle 10 is an electric vehicle. The vehicle 10 includes a high-voltage battery 20, a system main relay (hereinafter referred to as "SMR (System Main Relay)") 30, a power conversion device 60, a motor generator (hereinafter referred to as "MG (Motor Generator)") 80, and an electronic device. It includes a control unit (hereinafter referred to as "ECU (Electronic Control Unit)") 100.

The ECU 100 includes a CPU that executes a process for controlling a control target, and a memory that stores a program of the process and is used as a work memory for executing the program. The ECU 100 includes an SMR control unit 110 configured inside the CPU and transistors 120A and 120B. The SMR control unit 110 may be configured inside the CPU as software by executing a program by the CPU, or may be configured inside the CPU as hardware. The vehicle 10 further includes a collision detection unit 130, a low voltage battery 140, and a low voltage power line 150.

The high-voltage battery 20 stores high-voltage power supplied from the outside of the vehicle 10 and regenerative power supplied from the MG 80 via the inverter 70 and the power lines 62 and 63, and stores the high-voltage power used for driving the vehicle by the MG 80. It is supplied to the inverter 70 via the power lines 62 and 63.

The power conversion device 60 converts the electric power discharged from the high-voltage battery 20 into electric power suitable for driving the MG 80, and converts the electric power charged in the high-voltage battery 20 into electric power suitable for charging. The power conversion device 60 includes a discharge resistor 61, a smoothing capacitor 42, and an inverter 70.

The inverter 70 converts the DC power from the high-pressure battery 20 into three-phase AC power and supplies it to the MG 80, or converts the three-phase AC power from the MG 80 into DC power and supplies it to the high-pressure battery 20.

The SMR control unit 110 outputs a base current for turning on the SMR 30 to the transistors 120A and 120B in response to an operation by the driver to turn on the power switch. When the base current is input, the transistors 120A and 120B output the collector current supplied from the low voltage battery 140 via the low voltage power line 150 to the SMR 30.

The SMR control unit 110 stops the output of the base current to the transistors 120A and 120B in order to turn off the SMR 30 in response to the operation of turning off the power switch by the driver. When the base current is stopped, the transistors 120A and 120B stop the output of the collector current supplied from the low voltage battery 140 to the SMR 30 via the low voltage power line 150.

When the collector current is not input, the SMR 30 is turned off because the exciting current does not flow in the suction coil, and the high voltage battery 20 and the inverter 70 are made non-conducting, while the collector current is input. Since the exciting current flows through the suction coil, it is turned on and the high-voltage battery 20 and the inverter 70 are turned on.

The discharge resistor 61 is provided between the pair of power lines 62 and 63. The smoothing capacitor 42 is provided between the pairs of power lines 62 and 63 to smooth the voltage between the pairs of power lines 62 and 63.

If an electric charge is stored in the smoothing capacitor 42 before the SMR 30 is brought into a non-conducting state, a current flows from the smoothing capacitor 42 into the discharge resistor 61 and is converted into heat energy, which is consumed. Since the current always flows from the high-pressure battery 20 to the discharge resistor 61 when the SMR 30 is in a conductive state, the resistance value of the discharge resistor 61 is set to a sufficiently large value in order to suppress power consumption. To. Therefore, the power consumption in the discharge resistor 61 is slow.

When the collision detection unit 130 detects a collision of the vehicle 10, it outputs a signal indicating that the collision has been detected to the SMR control unit 110 of the ECU 100. The SMR control unit 110 stops the output of the base current to the transistors 120A and 120B in order to turn off the SMR 30 in response to receiving a signal indicating that a collision has been detected from the collision detection unit 130. When the base current is stopped, the transistors 120A and 120B stop the output of the collector current supplied from the low voltage battery 140 to the SMR 30 via the low voltage power line 150. When the collector current is no longer input, the SMR 30 is turned off, and the high-voltage battery 20 and the inverter 70 are brought into a non-conducting state.

In the vehicle 10 described above, even if the SMR 30 is turned off at the time of the collision of the vehicle 10 and the high voltage battery 20 and the inverter 70 are electrically cut off, electric charges may remain in the smoothing capacitor 42. In such a case, it is necessary to pay attention to the electric charge remaining in the smoothing capacitor 42 in the accident processing such as the rescue of the occupant of the vehicle 10.

In order to deal with such a situation, it is conceivable to provide a device for discharging the electric charge of the smoothing capacitor 42. For example, as such a device, conventionally, there has been a discharge switch in which a movable contact is normally held in an off position by a magnet, while a spring moves the movable contact to an on position when a vehicle collides. When this discharge switch is turned on due to a vehicle collision, both ends of the smoothing capacitor are short-circuited and the smoothing capacitor is discharged.

In this discharge switch, it is necessary to pass a short-circuit current through the discharge switch in order to discharge the smoothing capacitor in a short time when an inertial force is generated in the movable contact due to a vehicle collision. Therefore, the short-circuit current becomes a large current, an arc discharge occurs at the contact of the discharge switch, and the contact may be melted.

Therefore, as will be described later, the fast discharge device 40 is provided between the pair of power lines 62 and 63 that send DC power to the device (for example, MG80) that operates while the vehicle 10 is running, and is provided between the pair of power lines 62 and 63. It is a device for discharging the electric charge stored in the smoothing capacitor 42 that smoothes the voltage between them, and the potential difference between the discharge unit 41 electrically connected in parallel with the smoothing capacitor 42 and the power lines 62 and 63. It is provided with a collision detection switch 50 for supplying a trigger current.

The discharge unit 41 switches between the non-conducting state and the conducting state by the trigger current supplied from the collision detection switch 50, and conducts even if the trigger current disappears when the trigger current switches between the non-conducting state and the conducting state. It includes a self-holding switch section that maintains the state and a first resistance section that consumes power that passes when the self-holding switch section is in a conductive state.

The collision detection switch 50 supplies a trigger current to the self-holding switch unit by switching from the non-conducting state to the conducting state by contacting the contacts 51 by the force acting by the collision of the vehicle 10. The fast discharge device 40 is provided in the path through which the trigger current flows, and further includes a second resistance portion that suppresses the trigger current.

As a result, when the vehicle 10 collides, the contact 51 contacts the collision detection switch 50 to switch to the conduction state, and the trigger current flows to the self-holding switch portion, but the trigger current is suppressed by the second resistance portion. Since the trigger current flowing through the contact 51 does not become excessive, the generation of arc discharge can be suppressed and the contact 51 can be prevented from being melted. Further, even if the self-holding switch portion is switched to the conductive state and the trigger current disappears, the conductive state is maintained, so that the charge stored in the smoothing capacitor 42 is consumed in the first resistance portion. As a result, it is possible to prevent the contact 51 from being melted when the charge of the smoothing capacitor 42 is discharged.

With reference to FIG. 1 again, the discharge unit 41 includes the relays 43, 46 as the self-holding switch unit described above, and the exciter coils of the resistors 44, 45, 47 and the relays 43, 46 as the first resistance unit described above. And include. The collision detection switch 50 includes a contact 51, a movable piece 52, a compression coil spring 53, and a weight 54.

In the collision detection switch 50, a force in the left direction is applied to the movable piece 52 by the compression coil spring 53 in a normal time other than a collision, so that the weight 54 is pushed to the left end inside the collision detection switch 50 by being pushed by the movable piece 52. It will be in a state of being brought together. On the other hand, at the time of a collision, when the vehicle 10 and the collision detection switch 50 are excessively accelerated to the left due to the collision, the weight 54 tries to stay in place and exerts a force to the right on the movable piece 52. By being pushed by the weight 54, the movable piece 52 compresses the compression coil spring 53, and the contact 51 is closed by the movable piece 52.

In this way, the collision detection switch 50 switches from the non-conducting state to the conducting state when the contacts 51 come into contact with each other due to the force acting by the collision of the vehicle 10. As a result, a circuit is formed from the smoothing capacitor 42 to the smoothing capacitor 42 via the power line 62, the collision detection switch 50, the exciting coil of the relay 43, the resistor 44, and the power line 63. A trigger current for making the discharge unit 41 in a conductive state flows through this circuit.

Since this circuit has the above-mentioned excitation coil of the resistor 44 and the relay 43 as the second resistance portion, the trigger current is suppressed so that the trigger current flowing through the contact 51 of the collision detection switch 50 does not become excessive. , The generation of arc discharge is suppressed, and the contact 51 can be prevented from being melted. The resistance value of the resistor 44 and the specifications of the relay 43 are calculated by dividing the initial voltage of the smoothing capacitor 42 by the combined resistance value of the resistor 44 and the exciting coil of the relay 43. The value is designed so that it does not become excessive.

In the discharge unit 41, the contact of the relay 43 is closed by the trigger current from the collision detection switch 50 flowing through the exciting coil of the relay 43. Then, a circuit is formed that returns from the smoothing capacitor 42 to the smoothing capacitor 42 via the power line 62, the resistor 47, the contact of the relay 43, the resistor 45, and the power line 63. Therefore, the electric power from the smoothing capacitor 42 is consumed by the resistors 45 and 47. At this time, the contact of the relay 46 is closed by the current flowing through the exciting coil of the relay 46 provided in parallel with the resistor 45.

When the weight 54 returns to its original position, the contact 51 of the collision detection switch 50 is opened, and even if the trigger current from the collision detection switch 50 does not flow, the contact of the relay 46 is closed. A circuit is formed from the smoothing capacitor 42 to the smoothing capacitor 42 via the power line 62, the contact of the relay 46, the exciting coil of the relay 43, the resistor 44, and the power line 63. Therefore, as long as the electric charge remains in the smoothing capacitor 42, the current continues to flow in the exciting coil of the relay 43, so that the contacts of the relay 43 continue to be closed. As a result, the current state is maintained in the discharge unit 41. Further, the electric power from the smoothing capacitor 42 is consumed not only by the resistors 45 and 47 but also by the resistor 44.

When the charge of the smoothing capacitor 42 decreases to the extent that the contacts of the relay 43 and the relay 46 cannot be kept closed, the contacts of the relay 43 and the relay 46 are opened and no current flows through the discharge unit 41. The specifications of the relays 43 and 46 and the specifications of the resistors 44, 45 and 47 are the relay 43 and the relay 46 until the voltage of the smoothing capacitor 42 drops to a voltage that does not affect the handling of the collision accident. It is designed so that the contacts of the are not opened. Further, as the resistance value of the resistors 45 and 47 is smaller, the time required for discharging the smoothing capacitor 42 can be shortened. Therefore, the resistors 45 and 47 have a resistance value sufficiently smaller than the resistance value of the discharge resistor 61. Will be done.

In the circuit shown in FIG. 1, in the first period after the vehicle 10 collides, a current flows through the contact 51 of the collision detection switch 50, the exciting coil of the relay 43, and the first path of the resistor 44. In the second period thereafter, in addition to this first path, a current is applied to the second path of the resistor 47, the contact of the relay 43, and the resistor 45 (or the exciting coil of the relay 46) in parallel with the first path. Flows. In the third period after the contact 51 of the collision detection switch 50 is opened, in addition to the second path, the contact of the relay 46, the exciting coil of the relay 43, and the third path of the resistor 44 are changed to the first path. Current flows.

Since the substantial resistance of both the first path and the third path is the exciting coil of the relay 43 and the resistor 44, the combined resistance values of the first path and the third path are almost the same. Therefore, the combined resistance value of the circuit in the first period in which the current flows only in the first path is the second period in which the current flows in the first path and the second path, and the current flows in the second path and the third path. It becomes larger than the combined resistance value of the circuit in the third period. Therefore, assuming that the voltage Vc of the smoothing capacitor 42 is the same, the discharge current Ic of the smoothing capacitor 42 in the first period is smaller than the discharge current Ic in the second period and the third period.

FIG. 2 is a diagram showing changes in the voltage Vc of the smoothing capacitor 42 in this embodiment. With reference to FIG. 2, the voltage Vc of the smoothing capacitor 42 decreases monotonically as the first period, the second period, and the third period and the time t elapse.

FIG. 3 is a diagram showing changes in the discharge current Ic of the smoothing capacitor 42 in this embodiment. With reference to FIG. 3, during the first period, the discharge current Ic also decreases monotonically as the voltage Vc of the smoothing capacitor 42 decreases monotonically. However, when the first period elapses, the combined resistance value of the circuit decreases, so that the discharge current Ic once increases and then monotonically decreases again.

The resistance value of the resistor 44 and the specifications of the relay 43 are designed so that the current value of the first discharge current Ic in the first period is less than the current value that causes the contact 51 of the collision detection switch 50 to be melted. To.

As described above, according to the disclosure of the first embodiment, when the vehicle 10 collides, the collision detection switch 50 is switched to the conduction state by the contact 51, and the trigger current is the self-holding switch portion (relay 43) described above. , 46), but since the trigger current flowing through the contact 51 is not excessive due to the suppression of the trigger current by the above-mentioned second resistance portion (resistor 44), the generation of arc discharge is suppressed and the contact 51 It is possible to prevent melting damage. Further, even if the self-holding switch portion is switched to the conductive state and the trigger current disappears, the conductive state is maintained, so that the electric charge stored in the smoothing capacitor 42 is transferred to the first resistance portion (resistors 44, 45) described above. , 47). As a result, it is possible to prevent the contact 51 from being melted when the charge of the smoothing capacitor 42 is discharged.

In the vehicle 10, the low-voltage battery 140 and the fast discharge device 40 are often installed at locations separated from each other. Therefore, when the fast discharge device 40 is operated by the power of the low voltage battery 140, the fast discharge device 40 is operated when the power line from the low voltage battery 140 to the fast discharge device 40 is disconnected due to the collision of the vehicle 10. You will not be able to do it.

However, according to the disclosure of the first embodiment, the electric charge stored in the smoothing capacitor 42 is used for the operation of the fast discharge device 40 (collision detection switch 50, self-holding switch unit) without using the power of the low voltage battery 140. Therefore, even if the power line from the low-voltage battery 140 is disconnected or the low-voltage battery 140 itself is damaged at the time of the collision of the vehicle 10, the electric charge of the smoothing capacitor 42 can be reliably discharged.

Further, in the case of using the low voltage circuit using the low voltage power of the low voltage battery 140 in addition to the high voltage circuit using the high voltage power from the high voltage battery 20 and the smoothing capacitor 42 in the fast discharge device 40, the high voltage circuit and the low voltage circuit are isolated. It is necessary to employ a special circuit for this (for example, a relay having a double exciting coil isolated from each other). However, in the disclosure of the first embodiment, since only the high voltage power is handled by the fast discharge device 40, it is not necessary to provide such a special circuit, and the manufacturing cost can be reduced.

Further, according to the disclosure of the first embodiment, the SMR control unit 110 causes the exciting current from the low voltage battery 140 to flow through the suction coil of the SMR 30, so that the SMR 30 turns on the power supply from the high voltage battery 20. Therefore, even if the power line from the low-voltage battery 140 is disconnected or the low-voltage battery 140 itself is damaged at the time of the collision of the vehicle 10, the exciting current from the low-voltage battery 140 does not flow to the suction coil of the SMR 30. , The power supply from the high voltage battery 20 can be reliably cut off.

Further, in the fast discharge device 40, by arranging the smoothing capacitor 42, the collision detection switch 50, and the discharge unit 41 in close proximity to each other, the power lines 62 and 63 connecting them are disconnected due to the collision of the vehicle 10. It is possible to reduce the possibility that the fast discharge device 40 will not function.

[Second Embodiment]
In the first embodiment, the discharge unit 41 of the fast discharge device 40 of the power conversion device 60 of the vehicle 10 is configured to include the relays 43 and 46. In the second embodiment, the discharge unit 41A of the fast discharge device 40A of the power conversion device 60A of the vehicle 10A is configured to include the thyristor 91. Therefore, since the configurations other than the discharge unit 41A are the same as those in the first embodiment, the overlapping description will not be repeated.

FIG. 4 is a diagram showing an outline of the configuration of the vehicle 10A according to the second embodiment. With reference to FIG. 4, the discharge unit 41A includes the thyristor 91 as the self-holding switch unit described above and the resistor 94 as the first resistance unit described above. As the resistance value of the resistor 94 is smaller, the time required for discharging the smoothing capacitor 42 can be shortened. Therefore, the resistance value of the resistor 94 is set to be sufficiently smaller than the resistance value of the discharge resistor 61.

When the collision detection switch 50 is switched to the conduction state due to a collision, a circuit is formed from the smoothing capacitor 42 to the smoothing capacitor 42 via the power line 62, the collision detection switch 50, the resistor 92, the resistor 93, and the power line 63. .. Therefore, a trigger current for making the discharge unit 41A in a conductive state flows through this circuit by the electric power of the smoothing capacitor 42.

Since this circuit has the above-mentioned resistors 92 and 93 as the second resistance portion, the trigger current is suppressed, so that the trigger current flowing through the contact 51 of the collision detection switch 50 does not become excessive, so that the arc discharge occurs. The generation is suppressed, and the contact 51 can be prevented from being melted. The resistance value of the resistors 92 and 93 is calculated by dividing the initial voltage of the smoothing capacitor 42 by the combined resistance value of the resistors 92 and 93, and is designed so that the initial current value of the trigger current does not become excessive. Will be done.

In the discharge unit 41A, a voltage between the resistors 92 and 93 is applied between the cathode and the gate of the thyristor 91 to allow a gate current to flow, and the anode and the cathode of the thyristor 91 are in a conductive state. Become. Therefore, the electric power from the smoothing capacitor 42 is consumed by the resistor 94.

When the weight 54 returns to the original position, the contact 51 of the collision detection switch 50 is opened, the trigger current from the collision detection switch 50 does not flow, and even if the gate current does not flow, the thyristor 91 is conductive. Maintain the state. When the electric charge of the smoothing capacitor 42 disappears and no current flows through the anode of the thyristor 91, the thyristor 91 becomes non-conducting.

In the circuit shown in FIG. 4, a current flows through the contact 51 of the collision detection switch 50 and the fourth path of the resistors 92 and 93 in the first period after the vehicle 10A collides. In the second period thereafter, in addition to this fourth path, a current flows through the fifth path of the resistor 94 and the thyristor 91 in parallel with the fourth path. In the third period after the contact 51 of the collision detection switch 50 is opened, no current flows in the fourth path, and current flows only in the fifth path.

The combined resistance value of the circuit in the first period in which the current flows only in the fourth path is larger than the combined resistance value of the circuit in the second period in which the current flows in the fourth path and the fifth path. Therefore, assuming that the voltage Vc of the smoothing capacitor 42 is the same, the discharge current Ic of the smoothing capacitor 42 in the first period is smaller than the discharge current Ic in the second period.

Similar to FIG. 2, the voltage Vc of the smoothing capacitor 42 decreases monotonically as the first period, the second period, and the third period and the time t elapse.

Similar to FIG. 3, during the first period, the discharge current Ic also decreases monotonically as the voltage Vc of the smoothing capacitor 42 decreases monotonically. In the second period, since the combined resistance value of the circuit decreases, the discharge current Ic once increases and then monotonically decreases again. Unlike FIG. 3, in the third period, the combined resistance value of the circuit increases, so that the discharge current Ic decreases one step and then monotonically decreases.

The resistance values of the resistors 92 and 93 are designed so that the current value of the first discharge current Ic in the first period is less than the current value that causes the contact 51 of the collision detection switch 50 to be melted.

As described above, according to the disclosure of the second embodiment, when the vehicle 10A collides, the collision detection switch 50 is switched to the conduction state by the contact 51, and the trigger current is the self-holding switch portion (thyristor 91) described above. ), But the trigger current is suppressed by the above-mentioned second resistance section (resistors 92, 93), so that the trigger current flowing through the contact 51 is not excessive, so that the generation of arc discharge is suppressed and the contact 51 It is possible to prevent melting damage. Further, even if the self-holding switch portion is switched to the conductive state and the trigger current disappears, the conductive state is maintained, so that the electric charge stored in the smoothing capacitor 42 is transferred to the first resistance portion (resistor 94) described above. Be consumed. As a result, it is possible to prevent the contact 51 from being melted when the charge of the smoothing capacitor 42 is discharged.

[Modification example]
(1) In the above-described embodiment, the vehicles 10 and 10A are electric vehicles. However, the vehicle is not limited to this, and the vehicles 10 and 10A may be a vehicle provided with a smoothing capacitor 42 used for a high-voltage power line, may be a hybrid vehicle equipped with an engine in addition to a motor generator, or may be a fuel cell. It may be a fuel cell vehicle in which a motor is driven by the electric power generated in the above, or a vehicle in which a smoothing capacitor is used for other than driving a vehicle (for example, driving a compressor of a refrigerant such as an air conditioner).

(2) In the above-described embodiment, the technique relating to the situation where the vehicles 10 and 10A collide has been described. However, the above-mentioned technology is not limited to the situation where the vehicles 10 and 10A collide, and the situation where the impact is applied to the vehicles 10 and 10A (for example, the situation where a falling object has fallen on the vehicles 10 and 10A, the vehicle 10). , 10A has fallen under a cliff or into water), and it is also effective in a situation where a person has to touch the vehicles 10 and 10A when a high-voltage charge remains in the capacitor.

(3) In the above-described embodiment, as shown in FIGS. 1 and 4, the collision detection switch 50 is provided so that only collision detection in the uniaxial direction is possible. However, the present invention is not limited to this, and the collision detection switch 50 may be provided so as to enable collision detection in a multi-axis (for example, three-axis) direction. For example, three collision detection switches 50 are provided so that the directions in which the movable pieces 52 operate are orthogonal to each other in the three directions of the X, Y, and Z axes. In this case, the plurality of collision detection switches 50 are electrically connected in parallel. As a result, when any of the collision detection switches 50 becomes conductive, a trigger current flows through the discharge units 41 and 41A.

[summary]
As shown in FIGS. 1 and 4, the rapid discharge devices 40, 40A send DC power to a device (for example, an inverter 70 that exchanges power with MG 80) that operates while the vehicles 10 and 10 A are traveling. It is a discharge device for discharging the electric charge stored in the smoothing capacitor 42 provided between the pairs of 63 and smoothing the voltage between the pairs of the power lines 62 and 63, and is electrically connected in parallel with the smoothing capacitor 42. The discharged units 41 and 41A are provided with a collision detection switch 50 that supplies a trigger current using the potential difference between the pair of power lines 62 and 63.

As shown in FIGS. 1 and 4, the discharge units 41 and 41A switch from the non-conducting state to the conducting state between the pairs of the power lines 62 and 63 by the trigger current supplied from the collision detection switch 50, and by the trigger current. When switched to the conduction state, the self-holding switch unit (for example, relays 43, 46, thyristor 91) that maintains the continuity state even when the trigger current disappears, and the power that passes when the self-holding switch unit is in the conduction state are consumed. It includes a first resistor section (for example, resistors 45, 47, exciting coils of relays 43, 46, resistors 94).

As shown in FIGS. 1 and 4, the collision detection switch 50 sets the trigger current by itself by switching from the non-conducting state to the conducting state by contacting the contacts due to the force acting by the collision of the vehicles 10 and 10A. Supply to the holding switch section.

As shown in FIGS. 1 and 4, the fast discharge devices 40 and 40A are provided in the path through which the trigger current flows, and the second resistance portion (for example, the resistor 44, the exciting coil of the relay 43) that suppresses the trigger current is provided. It is further equipped with resistors 92,93).

As a result, when the vehicles 10 and 10A collide, the contact 51 contacts the collision detection switch 50 to switch to the conduction state, and the trigger current flows to the self-holding switch section, but the trigger current is suppressed by the second resistance section. As a result, the trigger current flowing through the contact 51 does not become excessive, so that the generation of arc discharge is suppressed and the contact 51 can be prevented from being melted. Further, even if the self-holding switch portion is switched to the conductive state and the trigger current disappears, the conductive state is maintained, so that the charge stored in the smoothing capacitor 42 is consumed in the first resistance portion. As a result, it is possible to prevent the contact 51 from being melted when the charge of the smoothing capacitor 42 is discharged.

The embodiments disclosed this time should be considered to be exemplary and not restrictive in all respects. The scope of the present disclosure is shown by the scope of claims rather than the description of the embodiments described above, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

10,10A vehicle, 20 high voltage battery, 30 SMR, 40,40A fast discharge device, 41,41A discharge part, 42 smoothing capacitor, 43,46 relay, 44,45,47,92,93,94 resistor, 50 collision Detection switch, 51 contacts, 52 movable pieces, 53 compression coil springs, 54 weights, 60, 60A power converters, 61 discharge resistors, 62,63 power lines, 70 inverters, 80 MG, 91 thyristors, 100 ECUs, 110 SMR controls , 120A, 120B transistor, 130 collision detector, 140 low voltage battery, 150 low voltage power line.

Claims (1)

It is a discharge device for discharging the electric charge stored in the capacitor that is provided between the power line pairs that send DC power to the equipment that operates while the vehicle is running and that smoothes the voltage between the power line pairs.
A discharge unit electrically connected in parallel with the capacitor,
It is equipped with a collision detection switch that supplies a trigger current using the potential difference between the power line pairs.
The discharge part is
When the trigger current supplied from the collision detection switch switches between the power line pairs from the non-conducting state to the conducting state and the trigger current switches to the conducting state, the self that maintains the conducting state even when the trigger current disappears. Holding switch part and
The self-holding switch unit includes a first resistance unit that consumes electric power that passes when the self-holding switch unit is in a conductive state.
The collision detection switch supplies the trigger current to the self-holding switch unit by switching from the non-conducting state to the conducting state by contacting the contacts due to the force acting by the collision of the vehicle.
A discharge device provided in a path through which the trigger current flows and further provided with a second resistance portion that suppresses the trigger current.

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