Electronic device

Abstract

An electronic device (1) includes: a housing (31) having a first opening (31a) and housing an electronic component and a discharge resistor; a discharge switch (21); a first cover (32) which closes the first opening (31a) and can be opened and closed; and a movement restricting member (35). The discharge switch (21) has a pair of terminals (22a, 22b) and a movable member (23) that is formed of a conductor and is located at an on position or a non-on position. The movement restricting member (35) allows the movable member (23) to be in the conductive position when the first cover (32) is opened, and maintains the movable member (23) in the non-conductive position when the first cover (32) is closed. When the movable member (23) is in the conductive position, the electronic component is electrically connected to the discharge resistor, and when the movable member (23) is in the non-conductive position, the electronic component is electrically isolated from the discharge resistor.

Description

Technical Field

[0001] This disclosure relates to an electronic device. Background Technology

[0002] Electronic devices, such as propulsion control devices and power supply devices installed in railway vehicles, include a housing, inside which electronic components are housed. To ensure safe maintenance of the electronic components, the electronic device has a structure that suppresses the power supply to the electronic device when the housing cover is opened. Such an electronic device is disclosed in Patent Document 1.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Utility Model Patent Publication No. 4-76530 Utility Model Content

[0006] Patent Document 1 discloses an electronic device comprising: a microswitch that is switched on and off according to the opening and closing of the housing cover; and a relay disposed in the pantograph raising circuit, which switches between an on-state and an off-state according to the state of the microswitch. When the cover is opened, the relay becomes off-state, electrically isolating the main circuit from the power supply. Therefore, even if the pantograph raising switch is accidentally operated during maintenance, power will not be supplied to the electronic device.

[0007] In the electronic device disclosed in Patent Document 1, in order to perform maintenance work on the main circuit more safely, in addition to electrically isolating the main circuit from the power supply when the cover is opened as described above, it is also necessary to discharge electronic components, such as capacitors, on which high voltages are applied before maintenance work. To further improve the safety of the electronic device, sometimes a switch is provided to electrically connect the capacitor to a discharge resistor when the electronic device is stopped, with the aim of reliably discharging the capacitor. This switch is, for example, an electronically controllable switch. When the electronically controllable switch malfunctions, it may sometimes be impossible to connect the capacitor to the discharge resistor and discharge it before maintenance work.

[0008] This disclosure is made in view of the above circumstances, and its purpose is to provide a highly secure electronic device.

[0009] To achieve the above objectives, the electronic device of this disclosure includes a housing, a discharge switch, a first cover, and a movement limiting member. The housing has a first opening. The housing houses electronic components and a discharge resistor for discharging the electronic components. The discharge switch has a pair of terminals and a movable member, and is housed in the housing. One of the terminals is electrically connected to the electronic components, and the other of the terminals is electrically connected to the discharge resistor. The movable member is formed of a conductor and is in a conducting position or a non-conducting position. In the conducting position, the movable member is in contact with both of the terminals; in the non-conducting position, the movable member is spaced apart from at least one of the terminals. The first cover seals the first opening and is openable and closable. The movement limiting member allows the movable member to be in the conducting position when the first cover is opened and maintains the movable member in the non-conducting position when the first cover is closed. When the movable member of the discharge switch is in the conducting position, the electronic components are electrically connected to the discharge resistor; when the movable member of the discharge switch is in the non-conducting position, the electronic components are electrically isolated from the discharge resistor.

[0010] The movable restrictor included in the electronic device of this disclosure allows the movable component to be in a conductive position when the first cover is opened. Thus, when the first cover is opened, the electronic components are electrically connected to the discharge resistor. As a result, a highly secure electronic device can be obtained. Attached Figure Description

[0011] Figure 1 This is a circuit diagram of the electronic device according to Embodiment 1.

[0012] Figure 2 This is a perspective view of the electronic device according to Embodiment 1.

[0013] Figure 3 This is a diagram showing the movement restriction member of Embodiment 1 and the discharge switch in the on state.

[0014] Figure 4 This is a diagram showing the movement restriction member of Embodiment 1 and the discharge switch in the off state.

[0015] Figure 5 This is a perspective view of the discharge switch according to Embodiment 1.

[0016] Figure 6 This is a perspective view showing the discharge switch in the off state according to Embodiment 2.

[0017] Figure 7 This is a perspective view showing the discharge switch in the ON state according to Embodiment 2.

[0018] Figure 8 This is a perspective view of the casing of embodiment 3.

[0019] Figure 9This is a perspective view of the electronic device according to Embodiment 3.

[0020] Figure 10 This diagram shows the movement restriction member, the discharge switch in the on state, and the key holding part in Embodiment 3.

[0021] Figure 11 This diagram shows the movement restriction member, the discharge switch in the off state, and the key holding part in Embodiment 3.

[0022] Figure 12 This is a diagram illustrating a modified example of the movement limiting member, the discharge switch in the on state, and the key holding part of the electronic device according to the embodiment.

[0023] Figure 13 This is a diagram illustrating a modified example of the electronic device according to the embodiment, including a movement limiting member, a discharge switch in the off state, and a key holding part.

[0024] Figure 14 This is a diagram showing a modified example of the movement limiting member, discharge switch, and key holding part of the electronic device according to the embodiment.

[0025] Symbol Explanation

[0026] 1, 2 Electronic equipment; 1a, 1b Input terminals; 11 Power conversion circuit; 12 Discharge circuit; 21, 51 Discharge switches; 22a, 22b, 52a, 52b Terminals; 23, 53 Movable components; 24, 54 Force-applying components; 25, 55 Terminal holding components; 26 Insulating components; 31 Housing; 31a First opening; 31b, 31c Second openings; 32 First cover; 33 Fixing frame; 34 Supporting component; 35 Movement limiting component; 35a Contact portion; 36, 37 Second cover; 38, 39 Locking mechanism; 40, 41 Key; 42 Protruding component; 55a, 55b, 56a, 56b Mounting part; 56 Movable component holding part; 57 Telescopic mechanism; 61, 62 Key holding part; 61a, 62a Holding mechanism; 61b, 62b Opening and closing limiting mechanism; 81 Cooling device; 91 Load device; AX1, AX2, AX3, AX4, AX5, AX6 Rotating axis; C1 Capacitor; R1, R2 Discharge resistor; SW1 Switching element. Detailed Implementation

[0027] Hereinafter, an electronic device according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts in the drawings will be labeled with the same reference numerals.

[0028] (Implementation Method 1)

[0029] As an example of electronic equipment, a DC-to-three-phase converter is provided, installed in a railway vehicle, to convert DC power supplied from a DC power source into three-phase AC power and supply it to the motor. Taking the DC-to-three-phase converter as an example, the electronic equipment 1 of Embodiment 1 will be described. Figure 1 The electronic device 1 shown is installed in a DC-powered railway vehicle. The electronic device 1 converts the supplied DC power into AC power for supplying to a load device 91, and then supplies the converted AC power to the load device 91. The load device 91 is, for example, a three-phase induction motor that generates the propulsion force of the railway vehicle.

[0030] Figure 1 The illustrated electronic device 1 includes an input terminal 1a connected to a power source and an input terminal 1b grounded. The electronic device 1 also includes: a power conversion circuit 11 that converts DC power supplied from the power source into AC power; a capacitor C1 connected between the input terminals 1a and 1b; and a discharge circuit 12 connected in parallel with the capacitor C1. The discharge circuit 12 has a switching element SW1 and a discharge resistor R1 connected in series, and a discharge switch 21 and a discharge resistor R2 connected in series.

[0031] Input terminal 1a is connected to a power source, specifically a current collector, via a contactor, reactor, etc. (not shown). The current collector obtains power from the substation via a power supply line. For example, the current collector is a pantograph or current collector shoe, and the power supply line is an overhead line or a third rail. Input terminal 1b is short-circuited to the rail via a grounding brush, grounding ring, wheel, etc. (not shown), thereby achieving grounding.

[0032] Capacitor C1 is disposed between the primary terminals of power conversion circuit 11 and is charged by DC power supplied by the power source. Capacitor C1 and an inductor (not shown) together form an LC filter to reduce harmonic components generated during the switching operation of power conversion circuit 11.

[0033] The power conversion circuit 11 converts the DC power supplied through capacitor C1 into three-phase AC power and outputs the three-phase AC power to the load device 91. The voltage and frequency of the three-phase AC power output by the power conversion circuit 11 are adjustable. The power conversion circuit 11 has multiple switching elements, such as IGBT (Insulated Gate Bipolar Transistor), GTO (Gate Turn-off Thyristor), MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), etc.

[0034] The power conversion circuit 11 has multiple switching elements that are controlled by control signals supplied by a power conversion control device (not shown), switching between on and off. Through the switching actions of these multiple switching elements, the power conversion circuit 11 performs power conversion.

[0035] Switching element SW1 and discharge resistor R1 are connected in parallel with capacitor C1. Switching element SW1 is electrically controlled by a switching control unit (not shown). For example, switching element SW1 has the same structure as the switching element in power conversion circuit 11. Switching element SW1 is controlled by a control signal output from the switching control unit, switching between on and off.

[0036] When the switching element SW1 is on, the discharge resistor R1 is electrically connected to the capacitor C1, and the capacitor C1 discharges. When the switching element SW1 is off, the discharge resistor R1 is electrically isolated from the capacitor C1. For example, when the voltage between the terminals of the capacitor C1 reaches an overvoltage, the switch control unit turns the switching element SW1 on, causing the capacitor C1 to discharge. Then, when the voltage between the terminals of the capacitor C1 reaches the target voltage range, the switch control unit turns the switching element SW1 off. As a result, the capacitor C1 is electrically isolated from the discharge resistor R1.

[0037] Discharge switch 21 and discharge resistor R2 are connected in parallel with capacitor C1. Discharge switch 21 switches between on and off via mechanical action. When discharge element 21 is on, discharge resistor R2 is electrically connected to capacitor C1, and capacitor C1 discharges. When discharge element 21 is off, discharge resistor R2 is electrically isolated from capacitor C1.

[0038] The following is a detailed description of the structure of electronic device 1. For example... Figure 2 As shown, the electronic device 1 includes a housing 31 that houses electronic components and discharge resistors R1 and R2, wherein the electronic components are... Figure 1 The electronic device 1 shown is comprised of components in which the discharge resistors R1 and R2 are used to discharge one example of an electronic component, namely capacitor C1. The housing 31 has a first opening 31a, which facilitates maintenance of the components of the electronic device 1.

[0039] The electronic device 1 further includes: a first cover 32 that seals the first opening 31a and is openable and closable; and a cooling device 81 that is housed inside the housing 31 and is thermally connected to an electronic component that generates heat when powered on, thereby cooling the electronic component by releasing the heat transferred from the electronic component to the surrounding air.

[0040] Figure 2In this diagram, the Z-axis direction represents the vertical direction. The penetration direction of the first opening 31a is defined as the Y-axis direction. The axis orthogonal to both the Z-axis and the Y-axis is defined as the X-axis. The same applies to subsequent figures. For example, electronic device 1 is installed under the base of the railway vehicle using a lifting device (not shown) with its Y-axis aligned with the width direction of the railway vehicle and its X-axis aligned with the travel direction of the railway vehicle.

[0041] On the side of the housing 31, specifically on the surface of the housing 31 facing the negative Y-axis, a first opening 31a is formed.

[0042] The first cover 32 opens and closes the first opening 31a by rotating about a rotation axis AX1 parallel to the Z-axis. The first cover 32 is formed by a plate-like member capable of covering the entire first opening 31a and its periphery.

[0043] The cooling device 81 includes, for example, a heating block thermally connected to electronic components inside the housing 31; fins mounted on the heating block and exposed outside the housing 31; and a cover covering the heating block and fins and having ventilation holes. Heat generated by the electronic components is transferred via the heating block and fins to air flowing into the interior of the cover through the ventilation holes, thereby cooling the electronic components.

[0044] The following describes the details of the structure used to improve the security of electronic device 1. Figure 3 and Figure 4 This is a view of the electronic device 1 from inside the housing 31 towards the first cover 32. To avoid complicating the accompanying drawings, Figure 3 and Figure 4 Only the discharge switch 21, a component of the electronic device 1 housed inside the casing 31, is shown. Figure 3 With the first cover 32 open as shown, the discharge switch 21 is switched on. Figure 4 With the first cover 32 closed as shown, the discharge switch 21 is turned off.

[0045] The discharge switch 21 includes a pair of terminals 22a, 22b and a movable member 23 located in a conducting or non-conducting position. Preferably, the discharge switch 21 further includes a force-applying member 24 that applies force to the movable member 23 in the conducting position. The discharge switch 21 also includes a terminal holding member 25 that holds the pair of terminals 22a, 22b.

[0046] The electronic device 1 further includes: a fixed frame 33 fixed to the inner surface of the housing 31; and a support member 34 mounted on the fixed frame 33 to support the discharge switch 21. The electronic device 1 also includes a movement limiting member 35, which allows the movable member 23 to be in the conducting position when the first cover 32 is opened, and maintains the movable member 23 in the non-conducting position when the first cover 32 is closed.

[0047] In embodiment 1, as shown in the perspective view of the discharge switch 21, Figure 5 As shown, terminals 22a and 22b are respectively shaped to clamp the movable member 23 in the Z-axis direction. One of terminals 22a and 22b is electrically connected to the electronic component to be discharged, namely capacitor C1. The other of terminals 22a and 22b is electrically connected to the discharge resistor R2. In Embodiment 1, one of terminals 22a and 22b is electrically connected to... Figure 1 The input terminal 1a shown is electrically connected to the connection point of the power conversion circuit 11, and the other of terminals 22a and 22b is electrically connected to the discharge resistor R2.

[0048] The movable member 23 is formed of a conductor. In embodiment 1, the movable member 23 is formed of a plate-shaped metal member. The movable member 23 is located at... Figure 3 and Figure 5 The conductive position that contacts terminals 22a and 22b as shown, or located in Figure 4 As shown, a non-conductive position spaced apart from at least one of terminals 22a and 22b. In Embodiment 1, as... Figure 5 As shown, one end of the movable member 23 is fixed to the terminal 22b by a fastening member. The movable member 23 rotates about the rotation axis AX2 extending parallel to the Z-axis, with the end fixed to the terminal 22b as the center.

[0049] The discharge switch 21 has a pair of force-applying members 24 positioned to clamp a movable member 23 in the Z-axis direction. The force-applying members 24 apply force to the movable member 23 in the conducting position. In embodiment 1, the force-applying member 24 is formed of an elastic body that deforms under external force and returns to its original shape when the external force is removed. When the elastic body is in its original shape, the movable member 23 is in the conducting position. Specifically, the force-applying member 24 is formed of a helical spring, one end of which is mounted to a terminal holding member 25 and the other end of which is mounted to the movable member 23 via an insulating member 26. When the helical spring is at its natural length, the movable member 23 is in the conducting position. The movable member 23... Figure 5When the movable member 23 is rotated clockwise along the positive Z-axis and is in the non-conductive position, the force-applying member 24 formed by the helical spring generates a force that restores it to its natural length. In other words, the force-applying member 24 pulls the movable member 23 from the non-conductive position to the conductive position. Thus, the movable member 23 is subjected to force from the non-conductive position to the conductive position.

[0050] The terminal retaining member 25 holds the terminals 22a and 22b in a state that insulates them from each other. The terminal retaining member 25 is formed of an insulating member, for example, of resin.

[0051] like Figure 3 and Figure 4 As shown, the fixing frame 33 is fixed to the inner surface of the housing 31 in a state of contact with the inner surface of the housing 31. The fixing frame 33 has stiffness and strength to the extent that it will not deform even under the maximum foreseeable vibration of the railway vehicle. For example, the fixing frame 33 is formed of metal components such as iron or aluminum. The fixing frame 33 only needs to be fixed to the housing 31 with strength sufficient to ensure that the positional relationship between the fixing frame 33 and the housing 31 does not change under the vibration of the railway vehicle during operation. The fixing frame 33 is fixed to the housing 31 by methods such as fastening based on fastening members, bonding based on adhesives, welding, brazing, etc.

[0052] The support member 34 possesses stiffness and strength sufficient to withstand even the maximum foreseeable vibrations of the railway vehicle without deformation. For example, the support member 34 may be formed from metal components such as iron or aluminum. The support member 34 only needs to be fixed to the fixed frame 33 with strength sufficient to maintain the positional relationship between the support member 34 and the fixed frame 33 without changing under vibrations from the moving railway vehicle. The support member 34 is fixed to the fixed frame 33 by methods such as fastening with fasteners, bonding with adhesives, welding, or brazing.

[0053] The support member 34 is equipped with the terminal holding member 25 of the discharge switch 21. The terminal holding member 25 is fixed to the support member 34 with a strength sufficient to ensure that the positional relationship between the terminal holding member 25 and the support member 34 does not change when subjected to vibrations during the operation of the railway vehicle. For example, the terminal holding member 25 is fixed to the support member 34 by means of fastening based on a fastening member.

[0054] The movement restriction member 35 is mounted on the surface of the first cover 32 facing the interior of the housing 31 and has a plate-shaped contact portion 35a extending in a direction away from the first cover 32. The movement restriction member 35 has stiffness and strength sufficient to not deform even under the maximum foreseeable vibration of the railway vehicle. For example, the movement restriction member 35 is formed of a metal component such as iron or aluminum. The movement restriction member 35 is fixed to the first cover 32 with a strength sufficient to ensure that the positional relationship between the movement restriction member 35 and the first cover 32 does not change under vibration during railway vehicle operation. The movement restriction member 35 is fixed to the first cover 32 by methods such as fastening based on fasteners, bonding based on adhesives, welding, brazing, etc. Insulation treatment is preferably applied to the movement restriction member 35.

[0055] like Figure 4 As shown, when the first cover 32 is closed, the contact portion 35a of the movement limiting member 35 abuts against the movable member 23, pushing the movable member 23 in the positive Y-axis direction. As a result, the movable member 23 rotates about the rotation axis AX2 with the end fixed to the terminal 22b as the center, spaced apart from the terminal 22a. Consequently, the movable member 23 is in a non-conductive position. During the period when the first cover 32 is closed, the movement limiting member 35 holds the movable member 23 in the non-conductive position.

[0056] During the operation of the railway vehicle, multiple switching elements of the power conversion circuit 11 switch on and off, thereby enabling power conversion. When the railway vehicle stops operating, that is, when the electronic device 1 stops operating, the power conversion control device turns off the multiple switching elements of the power conversion circuit 11. Then, the switch control unit turns on the switching element SW1, and the capacitor C1 is electrically connected to the discharge resistor R1, thereby discharging.

[0057] Maintenance work is performed on electronic device 1 while it is in a stopped state. During maintenance work, such as... Figure 3 As shown, when the first cover 32 is opened, the contact portion 35a of the movement limiting member 35 moves along with the rotation of the first cover 32, thereby separating it from the movable member 23. Consequently, the movable member 23 is forced from a non-conductive position to a conductive position under the action of the force-applying member 24. As a result, the movable member 23 contacts the terminals 22a and 22b, and the discharge switch 21 becomes closed. When the discharge switch 21 becomes closed, the capacitor C1 is electrically connected to the discharge resistor R2, thereby discharging. Therefore, even if the capacitor C1 cannot be discharged through the discharge resistor R1 due to a malfunction of the switching element SW1, the capacitor C1 can still be discharged through the discharge resistor R2.

[0058] As explained above, the movement limiting member 35 included in the electronic device 1 of Embodiment 1 allows the movable member 23 to be in the conducting position when the first cover 32 is opened. As a result, when the discharge switch 21 is turned on, the capacitor C1 is electrically connected to the discharge resistor R2, thereby discharging. In other words, when the first cover 32 is opened, the discharge switch 21 is turned on by mechanical action, enabling the capacitor C1, which is subjected to a high voltage, to discharge. Even if the capacitor C1 cannot be discharged through the discharge resistor R1 due to a failure of the switching element SW1, the discharge switch 21 can be turned on by the mechanical action of opening the first cover 32, thereby discharging the capacitor C1 through the discharge resistor R2, ensuring the safety of maintenance operations.

[0059] (Implementation Method 2)

[0060] The structure of the discharge switch is not limited to the examples described above. Any structure can be used as long as it is closed when the first cover 32 is closed and open when the first cover 32 is opened. In Embodiment 2, an electronic device 1 including a discharge switch with a structure different from that in Embodiment 1 will be described.

[0061] The electronic device 1 of embodiment 2 includes Figure 6 and Figure 7 The discharge switch 51 is shown. The structure of the electronic device 1 other than the discharge switch 51 is the same as that in embodiment 1. The discharge switch 51 is connected in series with the discharge resistor R2. The series-connected discharge switch 51 and discharge resistor R2 are connected in parallel with capacitor C1.

[0062] The discharge switch 51 switches between on and off states via mechanical action. When the discharge element 51 is on, the discharge resistor R2 is electrically connected to the capacitor C1, and the capacitor C1 discharges. When the discharge element 51 is off, the discharge resistor R2 is electrically isolated from the capacitor C1.

[0063] The discharge switch 51 includes a pair of terminals 52a and 52b, a movable member 53 located in a conducting position or a non-conducting position, and a force-applying member 54 that applies force to the movable member 53 in the conducting position. The discharge switch 51 also includes a terminal holding member 55 for holding the pair of terminals 52a and 52b, and a movable member holding portion 56 for holding the movable member 53.

[0064] In Embodiment 2, terminals 52a and 52b each have a columnar shape extending in the Y-axis direction. One of terminals 52a and 52b is electrically connected to the electronic component to be discharged, namely capacitor C1. The other of terminals 52a and 52b is electrically connected to the discharge resistor R2. In Embodiment 2, one of terminals 52a and 52b is electrically connected to... Figure 1The input terminal 1a shown is electrically connected to the connection point of the power conversion circuit 11, and the other of terminals 52a and 52b is electrically connected to the discharge resistor R2.

[0065] The movable member 53 is formed of a conductor. In embodiment 2, as... Figure 6 As shown, the movable member 53 is formed of a columnar metal member extending in the Y-axis direction. The movable member 53 has holes for terminals 52a and 52b to engage. The movable member 53 is located... Figure 7 The conductive positions that are in contact with terminals 52a and 52b as shown may be located at... Figure 6 The non-conductive positions are spaced apart from terminals 52a and 52b as shown.

[0066] The discharge switch 51 has a force-applying member 54 extending in the Y-axis direction. The force-applying member 54 applies force to the movable member 53 in the closed position. The force-applying member 54 is formed of an elastic body that deforms under external force and returns to its original shape when the external force is removed. When the elastic body is in its original shape, the movable member 53 is in the closed position. Specifically, the force-applying member 54 is formed of a helical spring with one end mounted to the terminal holding member 55 and the other end mounted to the movable member holding portion 56. When the helical spring is at its natural length, as... Figure 7 As shown, the movable component 53 is in the conductive position.

[0067] The movable member retaining part 56 that holds the movable member 53 from Figure 7 The movable member 53 moves along the positive Y-axis. When the movable member 53 is in the non-conducting position, the force-applying member 54 formed by the helical spring generates a force that restores it to its natural length. As a result, the movable member holding part 56 is forceped in the negative Y-axis direction. In other words, the movable member 53 is forceped from the non-conducting position to the conducting position.

[0068] The terminal holding member 55 holds the terminals 52a and 52b in a state that insulates them from each other. The terminal holding member 55 is formed of an insulating member, for example, of resin. In embodiment 2, as... Figure 6 As shown, the terminal holding member 55 has a box-shaped opening facing the positive Y-axis, housing terminals 52a and 52b spaced apart from each other inside. A flat mounting portion 55a, whose main surface is orthogonal to the Y-axis, is provided on the surface of the terminal holding member 55 facing the positive X-axis. A flat mounting portion 55b, whose main surface is orthogonal to the Y-axis, is provided on the surface of the terminal holding member 55 facing the negative X-axis.

[0069] The movable member holding portion 56 is formed of an insulating member, such as resin. In Embodiment 2, the movable member holding portion 56 has a box-shaped opening in the negative Y-axis direction, and accommodates the movable member 53 with a portion of the movable member 53 exposed. A flat mounting portion 56a with its main surface orthogonal to the Y-axis is provided on the surface of the movable member holding portion 56 facing the positive X-axis direction. A flat mounting portion 56b with its main surface orthogonal to the Y-axis is provided on the surface of the movable member holding portion 56 facing the negative X-axis direction.

[0070] One end of the force-applying member 54 is mounted to the mounting portion 55a of the terminal holding member 55, and the other end of the force-applying member 54 is mounted to the mounting portion 56a of the movable member holding portion 56. The movable member holding portion 56 is mounted to the terminal holding member 55 via a telescopic mechanism 57 that can extend and retract in the Y-axis direction. Specifically, one end of the telescopic mechanism 57 is mounted to the mounting portion 55b of the terminal holding member 55, and the other end of the telescopic mechanism 57 is mounted to the mounting portion 56a of the movable member holding portion 56.

[0071] When the first cover 32 is closed, the contact portion 35a of the movement limiting member 35 abuts against the mounting portion 56a of the movable member holding portion 56, pushing the movable member holding portion 56 in the positive Y-axis direction. As a result, the movable member 53 and the movable member holding portion 56 move integrally along the positive Y-axis, thereby separating themselves from the terminals 52a and 52b. In other words, the movable member 53 is in a non-conductive position. During the period when the first cover 32 is closed, the movement limiting member 35 holds the movable member 53 in the non-conductive position.

[0072] During the operation of the railway vehicle, multiple switching elements of the power conversion circuit 11 switch on and off, thereby enabling power conversion. When the railway vehicle stops operating, that is, when the electronic device 1 stops operating, the power conversion control device turns off the multiple switching elements of the power conversion circuit 11. Then, the switch control unit turns on the switching element SW1, and the capacitor C1 is electrically connected to the discharge resistor R1, thereby discharging.

[0073] Maintenance work is performed on electronic device 1 while it is in a stopped state. During maintenance, when the first cover 32 is opened, the contact portion 35a of the movement limiting member 35 moves along with the rotation of the first cover 32, and the contact portion 35a is spaced apart from the movable member holding portion 56. As a result, the movable member holding portion 56 is subjected to a force in the negative Y-axis direction under the action of the force-applying member 54. Consequently, as... Figure 7As shown, when the movable member 53 is forced from the non-conducting position to the conducting position, the movable member 53 contacts terminals 52a and 52b, and the discharge switch 51 becomes closed. When the discharge switch 51 becomes closed, the capacitor C1 is electrically connected to the discharge resistor R2, thereby discharging. Therefore, even if the capacitor C1 cannot be discharged through the discharge resistor R1 due to a failure of the switching element SW1, the capacitor C1 can still be discharged through the discharge resistor R2.

[0074] As explained above, the movement limiting member 35 included in the electronic device 1 of Embodiment 2 allows the movable member 53 to be in the conducting position when the first cover 32 is opened. As a result, when the discharge switch 51 is turned on, the capacitor C1 is electrically connected to the discharge resistor R2, thereby discharging. In other words, when the first cover 32 is opened, the discharge switch 51 is turned on by mechanical action, enabling the capacitor C1, which is subjected to a high voltage, to discharge. Even if the capacitor C1 cannot be discharged through the discharge resistor R1 due to a failure of the switching element SW1, the discharge switch 51 can be turned on by the mechanical action of opening the first cover 32, thereby discharging the capacitor C1 through the discharge resistor R2, ensuring the safety of maintenance operations.

[0075] (Implementation Method 3)

[0076] The electronic device may also have an interlocking mechanism that prevents the first cover 32 from being closed when another cover, different from the first cover 32, is unlocked. The electronic device 2 of Embodiment 3 will be described focusing on the differences from Embodiment 1.

[0077] like Figure 8 As shown, the housing 31 of the electronic device 2 has second openings 31b and 31c formed on the side opposite to the side where the first opening 31a is formed. Figure 9 As shown, the electronic device 2 includes a second cover 36 that blocks the second opening 31b and is openable and closable, and a second cover 37 that blocks the second opening 31c and is openable and closable. The electronic device 2 also includes a locking mechanism 38 for locking the second cover 36 and a locking mechanism 39 for locking the second cover 37.

[0078] The second cover 36 opens and closes the second opening 31b by rotating about a rotation axis AX3 parallel to the Z-axis. The second cover 36 is formed by a plate-like member capable of covering the entire second opening 31b and its perimeter.

[0079] The second cover 37 opens and closes the second opening 31c by rotating about a rotation axis AX4 parallel to the Z-axis. The second cover 37 is formed by a plate-like member capable of covering the entire second opening 31c and its periphery.

[0080] The key 40 of the locking mechanism 38 can only be removed when the second cover 36 is locked. The key 41 of the locking mechanism 39 can only be removed when the second cover 37 is locked.

[0081] like Figure 10 as well as Figure 11 As shown, the electronic device 2 includes a key holding part 61 for holding the key 40. The electronic device 2 also includes a key holding part 61 for holding the key 40. Figure 9 The key holding part 62 holds the key 41 shown. Figure 10 as well as Figure 11 To avoid complicating the accompanying drawings, the description of key 41 is omitted. The structure of the electronic device 2, other than the key holding parts 61 and 62, is the same as in Embodiment 1. To avoid complicating the accompanying drawings, Figure 10 and Figure 11 Only the discharge switch 21, which is housed inside the housing 31, is shown; the description of the rotation axis AX2 is omitted.

[0082] The key holding part 61 has a holding mechanism 61a, which is located at Figure 10 The unlock location and Figure 11 In any of the locked positions shown, the key 40 can be inserted and removed in the unlocked position, while removal of the inserted key 40 is suppressed in the locked position. The key holding part 61 also includes an opening and closing restriction mechanism 61b, which restricts the removal of the key 40 as shown in the figure. Figure 10 The first cover 32 is closed when the mechanism 61a is in the unlocked position, as shown, to prevent this, and to allow... Figure 11 The first cover 32 is closed when the retaining mechanism 61a is in the locked position as shown.

[0083] The insertion direction of the key 40 relative to the retaining mechanism 61a is aligned with the through direction of the first opening 31a, specifically with the Y-axis direction. The retaining mechanism 61a has a shape capable of rotating about a rotation axis AX5 extending in the insertion direction of the key 40. In other words, the retaining mechanism 61a is capable of rotating about a rotation axis AX5 parallel to the Y-axis. The opening and closing limiting mechanism 61b is formed by a protrusion mounted on the retaining mechanism 61a, extending radially orthogonal to the rotation axis AX5 of the retaining mechanism 61a, and rotating about the rotation axis AX5 as the retaining mechanism 61a rotates.

[0084] The key holding part 62 has the same structure as the key holding part 61. The key holding part 62 has a holding mechanism 62a, which is located in either an unlocked position or a locked position. In the unlocked position, the key 41 can be inserted and removed; in the locked position, the removal of the inserted key 41 is suppressed. The key holding part 62 also includes an opening and closing restriction mechanism 62b, which restricts the removal of the key 41 as follows: Figure 10 The first cover 32 is closed when the mechanism 62a is in the unlocked position, as shown, to prevent this, and to allow... Figure 11 The first cover 32 is closed when the retaining mechanism 62a is in the locked position as shown.

[0085] The insertion direction of the key 41 relative to the retaining mechanism 62a is aligned with the through direction of the first opening 31a, specifically with the Y-axis direction. The retaining mechanism 62a has a shape capable of rotating about a rotation axis AX6 extending in the insertion direction of the key 41. In other words, the retaining mechanism 62a is capable of rotating about a rotation axis AX6 parallel to the Y-axis. The opening and closing limiting mechanism 62b is formed by a protrusion mounted on the retaining mechanism 62a, extending radially orthogonal to the rotation axis AX6 of the retaining mechanism 62a, and rotating about the rotation axis AX6 as the retaining mechanism 62a rotates.

[0086] like Figure 10 As shown, if the first cover 32 is to be closed when the retaining mechanisms 61a and 62a are in the unlocked position, the contact portion 35a of the movement limiting member 35 installed on the first cover 32 abuts against the opening and closing limiting mechanisms 61b and 62b formed by the protrusions. Therefore, the first cover 32 can be prevented from being closed. When the retaining mechanisms 61a and 62a are in the unlocked position, the keys 40 and 41 can be removed from the retaining mechanisms 61a and 62a. Therefore, the second covers 36 and 37 can be unlocked. In other words, if the second covers 36 and 37 are in an unlockable state, the first cover 32 can be prevented from being closed.

[0087] like Figure 11As shown, when the retaining mechanisms 61a and 62a are in the locked position, the contact portion 35a of the movement limiting member 35 mounted on the first cover 32 does not abut against the opening and closing limiting mechanisms 61b and 62b formed by the protrusions. Therefore, the first cover 32 can be closed. As described above, the key 40, which can be removed from the locking mechanism 38 only when the second cover 36 is locked, is inserted into the retaining mechanism 61a. If the retaining mechanism 61a with the key 40 inserted rotates from the unlocked position to the locked position, the removal of the key 40 is suppressed, and the second cover 36 cannot be unlocked. Similarly, the key 41, which can be removed from the locking mechanism 39 only when the second cover 37 is locked, is inserted into the retaining mechanism 62a. If the retaining mechanism 62a with the key 41 inserted rotates from the unlocked position to the locked position, the removal of the key 41 is suppressed, and the second cover 37 cannot be unlocked. In this way, the second covers 36 and 37 are locked, and the keys 40 and 41 are inserted into the retaining mechanisms 61a and 62a respectively. When the retaining mechanisms 61a and 62a are in the locked position, the first cover 32 can be closed.

[0088] As explained above, the electronic device 1 of Embodiment 3 has an interlocking mechanism that suppresses the situation where the first cover 32 is closed while the second covers 36 and 37 are unlockable. As a result, the second covers 36 and 37 can be reliably locked, thereby obtaining a highly secure electronic device 2.

[0089] This invention is not limited to the examples of the above embodiments. Electronic devices 1 and 2 are not limited to DC-to-three-phase conversion devices; any structure including a discharge resistor R2 and a discharge switch 21 or discharge switch 51 can be any structure. As an example, electronic devices 1 and 2 can be power conversion devices installed in AC-powered railway vehicles that convert AC power supplied by a power source into three-phase AC power. In this case, besides… Figure 1 In addition to the structure shown, electronic devices 1 and 2 only need to have a converter that converts AC power into DC power and the capacitor C1 is charged by the DC power output by the converter.

[0090] As another example, electronic devices 1 and 2 may be railway vehicles equipped with direct current and DC (Direct Current) to DC converters that convert DC power supplied from the power source into DC power for supplying to the load device 91 and output the converted DC power.

[0091] As another example, electronic devices 1 and 2 may include multiple power conversion circuits 11 and a capacitor C1 provided for each power conversion circuit 11. In this case, electronic devices 1 and 2 may include a discharge circuit 12 shared with the multiple power conversion circuits 11, or they may include a discharge circuit 12 for each power conversion circuit 11. When a discharge circuit 12 is provided for each power conversion circuit 11, each discharge switch 21 or each discharge switch 51 only needs to be located adjacent to the first opening 31a. Thus, as long as the movable member 23 of each discharge switch 21 or the movable member 53 of each discharge switch 51 is in the conducting position when the first cover 32 is closed, and the movable member 23 of each discharge switch 21 or the movable member 53 of each discharge switch 51 is maintained in the non-conducting position when the first cover 32 is opened.

[0092] The discharge circuit 12 may also omit the switching element SW1 and the discharge resistor R1, and instead only have the discharge switch 21 and the discharge resistor R2. Similarly, the discharge circuit 12 may also only have the discharge switch 51 and the discharge resistor R2.

[0093] The structures of electronic devices 1 and 2 are not limited to the examples above. Any structure in which the movable member 23 of the discharge switch 21 or the movable member 53 of the discharge switch 51 is in a non-conductive position when the first cover 32 is closed, and the movable member 23 of the discharge switch 21 or the movable member 53 of the discharge switch 51 is maintained in a conductive position when the first cover 32 is opened.

[0094] As an example, the first cover 32 can also be rotated about a rotation axis parallel to the X-axis to open and close the first opening 31a. In this case, the first cover 32 can be located on the upper side of the first cover 32 in the vertical direction and rotate about a rotation axis extending parallel to the X-axis, or it can be located on the lower side of the first cover 32 in the vertical direction and rotate about a rotation axis extending parallel to the X-axis.

[0095] The structure, installation position, electrical connection position, and installation direction of the discharge switch 21 or discharge switch 51 are not limited to the examples above. As long as the first cover 32 is closed when closed and becomes connected when the first cover 32 is opened, it can be arbitrary.

[0096] As an example, discharge switches 21 and 51 may also lack force-applying components 24 and 54. Figure 12 as well as Figure 13 The image shows a modified example of an electronic device 1 including a discharge switch 21 without a force-applying member 24. If we consider... Figure 12As shown, when the first cover 32 is opened, it becomes closed. Before the first cover 32 is fully closed, the contact portion 35a of the movement limiting member 35 abuts against the movable member 23. If the first cover 32 moves further toward the housing 31, the contact portion 35a of the movement limiting member 35 abuts against the movable member 23 and lifts one end of the movable member 23 vertically upward. Thus, the movable member 23 rotates about the rotation axis AX2. Specifically, the movable member 23 rotates clockwise when viewed in the negative Y-axis direction. Figure 13 When the first cover 32 is completely closed as shown, one end of the movable member 23 is spaced apart from the terminal 22a. As a result, the discharge switch 21 becomes off.

[0097] If from Figure 13 When the first cover 32 is opened, causing the contact portion 35a of the movement limiting member 35 to move away from the movable member 23, one end of the movable member 23 moves downward in the vertical direction due to its own weight. As a result, the movable member 23 rotates about the rotation axis AX2. Specifically, the movable member 23 rotates counterclockwise when viewed in the negative Y-axis direction. Then, as... Figure 12 As shown, the movable member 23 comes into contact with terminals 22a and 22b. As a result, the discharge switch 21 is turned on.

[0098] As another example, one of the terminals 22a and 22b of the discharge switch 21 can be electrically connected to the connection point of the input terminal 1b and the power conversion circuit 11, and the other terminal 22a and 22b can be electrically connected to the discharge resistor R2.

[0099] As another example, the preferred discharge switches 21 and 51 are switches that switch between on and off by mechanical action as described above. However, they can also be formed by electronic switches that turn on when the first cover 32 is opened and turn off when the first cover 32 is closed. Specifically, they can be formed by optical switches, micro switches, etc.

[0100] The force-applying components 24 and 54 are not limited to helical springs, but can be formed of any elastic body such as leaf springs, disc springs, or rubber. The force-applying components 24 and 53 can apply force to the conducting position as described in the above embodiment, or they can apply force to the non-conducting position. When the force-applying components 24 and 54 apply force to the non-conducting position, for example, the movement limiting member 35 installed on the first cover 32 engages with the movable members 23 and 53 when the first cover 32 is opened, causing the movable members 23 and 53 to move to the conducting position.

[0101] The structure of the movement limiting member 35 is not limited to the examples described above. Any structure can be used as long as it abuts against the movable member 23 or the movable member 53 when the first cover 32 is closed, thereby maintaining the movable member 23 or the movable member 53 in a non-conductive position. As an example, the movement limiting member 35 may have a columnar shape with one end mounted to the first cover and extending in the Y-axis direction.

[0102] The above embodiments can be combined in any way. As one example, the electronic device 2 may include the discharge switch 51 shown in Embodiment 2. As another example, the electronic device 2 may include... Figure 12 and Figure 13 The discharge switch 12 and the movement limiting member 35 are shown.

[0103] The structure of the interlocking mechanism included in electronic device 2 is not limited to the examples described above. As an example, electronic device 2 can suppress the first cover 32 from being closed when the retaining mechanisms 61a and 62a are in the unlocked position by means of a component independent of the movement limiting member 35. Figure 14 The image shows a modified example of an electronic device 2 that includes a protruding member 42 independent of the movement limiting member 35.

[0104] The protruding member 42 has a surface mounted on the first cover 32 facing the interior of the housing 31 and extending in a direction away from the first cover 32. If the first cover 32 is to be closed when the retaining mechanisms 61a and 62a are in the unlocked position, the protruding member 42 mounted on the first cover 32 abuts against the opening / closing limiting mechanisms 61b and 62b formed by the protrusions. Therefore, the first cover 32 can be prevented from being closed. If the retaining mechanisms 61a and 62a are in the locked position, the protruding member 42 mounted on the first cover 32 does not abut against the opening / closing limiting mechanisms 61b and 62b formed by the protrusions. Therefore, the first cover 32 can be closed. In this case, the movement limiting member 35 only needs to have a shape that abuts against the movable member 23 but not against the opening / closing limiting mechanisms 61b and 62b.

[0105] The orientation of the electronic devices 1 and 2 installed on the railway vehicle is not limited to the examples above, and can be any orientation. The electronic devices 1 and 2 are not limited to being installed on railway vehicles, but can also be installed on any moving body such as automobiles, airplanes, and ships, and can also be placed in any stationary location.

[0106] The load device 91 is not limited to a three-phase induction motor, but can also be a synchronous motor or a DC motor. The load device 91 is not limited to a motor, but can also be any equipment installed on a railway vehicle.

[0107] Various embodiments and modifications can be made to this utility model without departing from its broad concept and scope. Furthermore, the above embodiments are only used to illustrate this disclosure and do not limit its scope. That is, the scope of this disclosure is indicated by the scope of the claims, not by the embodiments. Moreover, various modifications implemented within the scope of the claims and their equivalents are also considered to be within the scope of this disclosure.

Claims

1. An electronic device, comprising: include: A housing having a first opening and one or more second openings, and housing electronic components and a discharge resistor for discharging the electronic components; A discharge switch having a pair of terminals and a movable member, and housed in a housing, wherein one of the pairs of terminals is electrically connected to the electronic component, and the other of the pairs of terminals is electrically connected to the discharge resistor, the movable member being formed of a conductor, the movable member being in a conducting position or a non-conducting position, wherein in the conducting position the movable member is in contact with both of the pairs of terminals, and in the non-conducting position the movable member is spaced apart from at least one of the pairs of terminals; A first cover, which seals the first opening and can be opened and closed; A movement limiting member that allows the movable member to be in the conducting position when the first cover is opened, and maintains the movable member in the non-conducting position when the first cover is closed; One or more second covers, which seal the second opening and are openable and closable; One or more locking mechanisms that lock the second cover and allow the key to be removed only when locked; as well as A key holding part, disposed inside the housing, is used to hold the key. The key holding part has: A retaining mechanism, located in either an unlocked position or a locked position, wherein in the unlocked position the key can be inserted and removed, and in the locked position the removal of the inserted key is inhibited; and An opening and closing limiting mechanism that inhibits the first cover from being closed when the retaining mechanism is in the unlocked position, and allows the first cover to be closed when the retaining mechanism is in the locked position. When the movable member of the discharge switch is in the conducting position, the electronic component is electrically connected to the discharge resistor; when the movable member of the discharge switch is in the non-conducting position, the electronic component is electrically isolated from the discharge resistor.

2. The electronic device as claimed in claim 1, characterized in that, The movement limiting member is mounted on the inner surface of the first cover facing the housing. The movement limiting member has a plate-shaped contact portion extending in a direction away from the first cover. When the first cover is closed, the contact portion abuts against the movable member, thereby maintaining the movable member in the non-conductive position.

3. The electronic device as described in claim 1 or 2, characterized in that, The movable member has one end fixed to one of the pair of terminals and is rotatable about the fixed end.

4. The electronic device as described in claim 1 or 2, characterized in that, The movable member has a shape that engages with two of the pair of terminals in the conductive position, and is spaced apart from the two of the pair of terminals in the non-conductive position.

5. The electronic device as described in claim 1 or 2, characterized in that, The discharge switch also has a force-applying member that applies force to the movable member toward the conduction position.

6. The electronic device as claimed in claim 5, characterized in that, The force-applying component has an elastic body that deforms under external force and returns to its original shape when the external force is removed. When the elastomer is in its original shape, the movable member is in the conductive position.

7. The electronic device as claimed in claim 1 or 2, characterized in that, The insertion direction of the key relative to the retaining mechanism is consistent with the through direction of the first opening. The retaining mechanism has a shape that allows it to rotate about a rotation axis extending in the insertion direction of the key. The opening and closing limiting mechanism is formed by a protrusion mounted on the retaining mechanism, extending radially orthogonal to the rotation axis of the retaining mechanism, and rotating with the rotation of the retaining mechanism.

8. The electronic device as claimed in claim 7, characterized in that, When the retaining mechanism is in the unlocked position, the movement limiting member mounted on the first cover abuts against the protrusion to prevent the first cover from being closed.

9. The electronic device as claimed in claim 7, characterized in that, The electronic device further includes a protruding member mounted on the inner side of the first cover facing the housing and extending in a direction away from the first cover. When the retaining mechanism is in the unlocked position, the protrusion abuts against the protruding member to prevent the first cover from being closed.

Images