Power supply control device

A power supply control device includes a body part in which a circuit block is accommodated; a first cable drawn outside from the body part to be connected to a charge circuit of an electric vehicle; a second cable drawn outside from the body part to be connected to a power source; and a sealing member sealing a gap between each of the cables and a corresponding cable passing port of the body part. The power supply control device further includes an outer restriction member provided at each of the cables on an outer side than the sealing member to prevent the corresponding cable from being bent.

FIELD OF THE INVENTION

The invention relates to a power supply control device.

BACKGROUND OF THE INVENTION

In recent years, an electric vehicle driven by electric power, such as an electric vehicle (EV) with a storage battery and a plug-in hybrid vehicle (PHV), has been practically used. Such electric vehicle has an in-vehicle charger that receives electric power from an external power source, such as a commercial 100 Vac power source, to charge a built-in battery for traveling. Herein, if an electric leakage occurs on the vehicle side when the battery is charged, an excessive current may flow into the in-vehicle charger. Therefore, a power supply control device is used for intercepting the power supply to the electric vehicle when the leakage occurs (e.g., see Japanese Patent Application Laid-open No. 2009-240053).

FIG. 11is a block circuit diagram of a power supply control device101. The power supply control device101is configured to accommodate a relay2, a zero-phase current transformer3, a control circuit4, and a power circuit5within a housing110(seeFIG. 12). The power supply control device101is provided with a power side plug P1connected to an external power source, and a vehicle side plug P2connected to an in-vehicle charger in a vehicle. These plugs P1and P2, and the circuits in the housing110are connected via cables C1and C2. Now, the cable C1between the power supply control device101and the power side plug P1includes two power wires L1and L2, and a ground wire L3. Further, the cable C2between the power supply control device101and the vehicle side plug P2includes the above three wires L1to L3and an electric wire L4for transmitting signals to and from the in-vehicle chargers.

The relay2has relay contacts2aprovided in internal conductive lines connected to the power wires L1and L2, respectively, and the control circuit4controls ON/OFF operations of the relay contact2a.

The zero-phase current transformer3is used for detecting an unbalanced current that flows through the power wires L1and L2when the leakage occurs.

The control circuit4opens or closes the relay2based on control signals inputted from the in-vehicle charger of the electric vehicle via the electric wire L4, so that the power supply to the in-vehicle charger is turned off or on. Besides, when detecting the unbalanced current flowing through the zero-phase current transformer3, the control circuit4opens the relay2to cut off the leak current flowing into the electric vehicle.

The power circuit5, to which an electric power is supplied from the external power source, supplies the electric power to the control circuit4.

The housing110of the power supply control device101, as shown inFIG. 12, includes a body111with a rectangular parallelepiped shape of which one side is opened, and a cover112attached to the body111so as to cover the opening of the body111. The relay2, the zero-phase current transformer3, the control circuit4, and the power circuit5, which are described above, are accommodated in an inner space defined by the body111and the cover112. In opposite side walls of the body111in its longitudinal direction (up and down side walls inFIG. 12), joint portions with the cover112are each recessed to provide a cable passing port17for introducing the cable C1or C2.

By the way, in view of wet circumstances in an outdoor parking space, the power supply control device101requires high waterproof performance. Higher waterproof performance needs complete sealing of the housing110. The housing110is, however, configured to be opened and closed for replacement of the cables C1and C2when they are broken by, e.g., a vehicle passing over them. Each of the cables C1and C2introduced into the housing110is connected to a terminal box disposed within the housing110to be electrically connected to the internal circuit. On the other hand, the cables C1and C2, which are connected to the respective terminal boxes, are extended to outside through the respective cable passing ports17. Therefore, it becomes necessary to prevent, e.g., rain water from infiltrating into the housing110through the cable passing ports17. Accordingly, in the power supply control device101disclosed in the above-cited reference, a gasket50provided on each of the cables C1and C2is attached to the cable passing port17to seal a gap between the body111, the cover112, and the cables C1and C2.

The gasket50, as shown inFIG. 13, has: a cylinder part51surrounding the cables C1and C2; and a couple of flanges52and53protruding outwardly from the cylinder part51and sealing the gap between the body111, the cover112, and the cables C1and C2. Further, in order to make the cylinder part51flexible, a plurality of annular grooves54extending circumferentially is formed on the cylinder part51at predetermined intervals in an axial direction thereof.

In the power supply control device with such configuration, the gasket50provided on each of the cables C1and C2is attached to the cable passing port17for the purpose of ensuring waterproof performance of the housing110. When the cable C1or C2is bent in directions denoted by arrows A1and A2inFIG. 13A, the gasket50is hardly bent in conformity with the bending of the cable C1or C2. This may cause a gap between an outer surface of the cable C1or C2and the gasket50, which deteriorates the waterproof performance.

SUMMARY OF THE INVENTION

In view of the above, the present invention provides a power supply control device capable of ensuring waterproof performance even when a cable thereof extending to outside is bent by an external force applied thereto.

In accordance with an aspect of the present invention, there is provided a power supply control device including: a body part in which a circuit block is accommodated; a first cable drawn outside from the body part to be connected to a charging circuit of an electric vehicle; a second cable drawn outside from the body part to be connected to a power source; a sealing member sealing a gap between each of the cables and a corresponding cable passing port of the body part; and an outer restriction member provided at each of the cables on an outer side than the sealing member to prevent the cable from being bent.

In the power supply control device, an inner restriction member may be provided at each of the cables on an inner side than the sealing member.

In the power supply control device, the restriction members may have a substantially cylindrical shape formed independently of the body part, and each cable may be inserted thereinto.

In the power supply control device, a tension preventing member for receiving an external force applied to each cable may be provided on an outer side than the outer restriction member that is located on the outer side than the sealing member.

In the power supply control device, with respect to each cable, the sealing member, the restriction member, and the tension preventing member may be held by a cap member detachably attached to the body part.

In the power supply control device, the tension preventing member may include a tubular member whose inner diameter is decreased by being held by the cap member to prevent the corresponding cable from being tensioned. Besides, the body part and the tensile prevention member may be provided with depression-projection engaging parts that are engaged with each other in a circumferential direction of each cable to prevent the tension preventing member from rotating.

With such configurations, since the portion of each cable on the outer side than the sealing member is prevented from being bent by the outer restriction member, it becomes difficult to generate a gap between the sealing member and the cable. Therefore, the contact condition between the sealing member and the cable is stabilized, which improves the waterproof performance.

DETAILED DESCRIPTION OF THE EMBODIMENT

Hereinafter, an embodiment of a power supply control device in accordance with the present invention will be described with reference to the drawings. The power supply control device of the present embodiment is used for charging an electric vehicle (an electric vehicle of storage battery type, a plug-in hybrid car, and the like) at home, and is adapted to turn on and off power supply to a charging circuit provided in the electric vehicle. Hereinafter, up-down and left-right directions are defined based on the directions shown inFIG. 2A, and a front-rear direction is defined based on the right-left direction inFIG. 2D. However, the above directions are defined for convenience of explanation, and do not necessarily congruous with the directions in the actual use state of the power supply control device.

The power supply control device1includes a housing (body part)10having a body11with a rectangular parallelepiped shape of which one side is opened; and a cover12attached to the body11so as to close the opening of the body11, as shown inFIGS. 2A to 6. A groove11ais formed in end surfaces of side walls of the body11(facing the cover12). When the body11and the cover12are coupled with screws in the state where an O-ring16is fitted into the groove11a, a gap between the body111and the cover12is sealed with the O-ring16. At one end of the cover12in a longitudinal direction thereof, a supporting part13protruding outwardly beyond the body11is provided. A through hole13ais formed in the supporting part13. By fitting the through hole13aonto a pin which is fixed on such as a wall surface, the housing10can be hung on the wall.

A cable C1(a second cable) to be connected to a power receptacle (not shown) is drawn out of the housing10from one side wall of the body11(on the side of the supporting part13) in a longitudinal direction thereof. A cable C2(a first cable) to be connected to a charging circuit (not shown) of an electric vehicle is drawn out of the housing10from another side wall of the body11, which is opposite to the side wall from which the cable C1is drawn. Note that, the cable C1on the power source side includes power wires L1and L2to be connected to power terminals of an external power source such as a commercial power source 100 Vac; and a ground wire L3to be connected to a ground terminal of the external power source. These three wires L1to L3are covered with an external shell40made of a flexible material (e.g., elastomer) to form the single cable C1. The cable C2on the vehicle side includes two power wires L1and L2, a ground wire L3, and an electric wire L4for transmitting signals to and from an in-vehicle charger of an electric vehicle, which are covered with an external shell40to form the single cable C2.

In a front surface of the body11, exposed holes are opened to expose various kinds of operation buttons and display lamps. A transparent cover18is attached to the front surface of the body11so as to cover these exposed holes. Besides, a label19is attached so as to cover the transparent cover18, and the label19is provided with characters and symbols indicating functions of the operation buttons and the display lamps.

The power supply control device1, like the power supply control device described in the Background of the Invention section, has such a circuit configuration as shown inFIG. 11which mainly includes the relay2, the zero-phase current transformer3, the control circuit4, and the power circuit5.

The relay2has relay contacts2aprovided in conductive paths that are connected to the power wires L1and L2serving as power supply lines, respectively. An ON/OFF operation of the relay contact2ais controlled by the control circuit4.

The zero-phase current transformer3is used for detecting an unbalanced current flowing through the power wires L1and L2when current leakage occurs.

Based on signals inputted from the charging circuit of the electric vehicle via the electric wire L4, the control circuit4opens or closes the relay2, so that power supply to the charging circuit is turned off or on. Further, when detecting the unbalanced current flowing into the zero-phase current transformer3, the control circuit4opens the relay2to intercept power supply to the electric vehicle. The relay2, the zero-phase current transformer3, and the control circuit4constitute a current leakage breaker.

The power circuit5is connected to each of the power wires L1and L2and the ground wire L3at points located closer to the external power source than the relay contacts2a. The power circuit5receives power from the external power source and supplies a drive power to the control circuit4.

Within the housing10, a circuit block20including the above-described circuits is accommodated. This circuit block20includes: a first printed wiring board21on which the power circuit5is mounted; a second printed wiring board22on which the control circuit4is mounted; a terminal box TB1to which the cable C1is connected; and a terminal box TB2to which the cable C2is connected.

The terminal box TB1has three terminals to which the wires L1to L3are respectively connected, and is disposed at one longitudinal end portion within the housing10. The terminal box TB2has four terminals to which the wires L1to L4are respectively connected, and is disposed at the other longitudinal end portion within the housing10. The terminals of the terminal boxes TB1and TB2, to which the wires L1to L3are connected respectively, are electrically connected therebetween via several bus bars (not shown) made of elongated metal plates. These bus bars are molded integrally with a mounting base23made of a resin-molding. The relay2is connected to each of the bus bars to which the power wires L1and L2are respectively connected. These two bus bars are extended through a center hole of an annular core with which the zero-phase current transformer3is provided.

Meanwhile, the mounting base23holding the bus bars has a substantially rectangular plate shape, and a side wall23ais provided at a peripheral edge of the mounting base23to protrude from the peripheral edge in opposite thickness directions (back and forth directions). On one surface of the mounting base23(facing the bottom of the body11), the second printed wiring board22, on which the control circuit4is mounted, is attached to a region surrounded by the side wall23a. On the other surface of the mounting base23(opposite to the body11), the terminal boxes TB1and TB2, the relays2and2, and the zero-phase current transformer3are arranged. A plurality of columns is provided on the other surface of the mounting base23, and a first printed wiring board21, on which the power circuit5is mounted, is screwed to these columns. Since the first printed wiring board21is fixed to the mounting base23through the columns, a space is defined between the first printed wiring board21and the mounting base23, and components of the power circuit5mounted on the first printed wiring board21is accommodated in the space.

As described above, the terminal boxes TB1and TB2are arranged at longitudinally opposite end portions within the body11. Cylindrical bosses15are provided on the longitudinally opposite side walls of the body11to be protruded therefrom outwardly. Each of the bosses15is provided with a through-hole14communicating with the inside and the outside of the body11. Through the through-hole14(cable passing port), the cables C1and C2are drawn out of the housing10.

Inside each of the bosses15, a sealing member30and outer and inner restriction members31aand31b, through which the cable C1or C2passes, are disposed. The sealing member30is formed of a flexible synthetic resin material, and preferably formed of, for instance, ethylene-propylene rubber with large elasticity, which can resist ultraviolet rays (namely, which has strong weather-resistance). The sealing member30is designed to have an inner diameter smaller than outer diameters of the cables C1and C2, and to have an outer diameter larger than an inner diameter of the boss15. On the other hand, the restriction members31aand31bare formed of a synthetic resin material having a small elasticity not to be deformed by an external force applied by the cables C1and C2. Besides, the restriction members31aand31bare formed into a cylindrical shape which has an approximately rectangular shape in axial section, and are disposed on both sides of the sealing member30. The restriction members31aand31bare designed to have an inner diameter substantially same as the outer diameters of the cables C1and C2, and to have an outer diameter substantially equal to or smaller than the inner diameter of the boss15. Accordingly, when the cable C1or C2is passed through the restriction members31aand31b, portions of the cable C1or C2held by the restriction members31aand31bremain their original shapes without being bent. Note that, the innermost portion of the through-hole14has an inner diameter smaller than that of the other portions. Further, the inner diameter of the innermost portion is designed to be larger than the outer diameters of the cables C1and C2and smaller than the outer diameters of the restriction members31aand31b. This prevents the restriction members31aand31bfrom entering an accommodation space within the housing10from the boss15.

A tension preventing ring32, through which the cables C1and C2are passed, is disposed on the outside of the boss15. The tension preventing ring32includes an annular ring part33having an outer diameter approximately the same as that of the boss15, the cable C1or C2passing through the annular ring part33; and a plurality of pressing pieces34protruded from one side of the ring part33in its axial direction, the pressing pieces34being circumferentially spaced apart at regular intervals. At a tip end of each pressing piece34, there is provided a claw34aprotruding toward the cable C1or C2. On the opposite side to the claw34a, each pressing piece34has a tapered surface34btapered as it goes to the tip end.

Then, the boss15is covered with a cap member35that is made of a synthetic resin and has a substantially cylindrical shape whose bottom surface has a cable passing hole35a. Flanges35c, each having an insertion hole35b, are provided at diametrically opposite end portions of the cap member35on its opening side. Joint screws36inserted into the insertion holes35bare screwed into screw holes provided in the body11, respectively, so that the cap member35is fixed to the body11. Note that a special screw of which a screw head is formed to have a Y-shaped groove is employed as the joint screw36. Accordingly, since the joint screw36cannot be removed with a usual Phillips head screwdriver, the cap member35is prevented from being detached by general users.

Next, the configuration for sealing portions at which the cables C1and C2are drawn out of the housing10, with reference toFIG. 1andFIGS. 7 to 10, will be described in detail. First of all, the cables C1and C2on each of which the sealing member30and the restriction members31a,31bare fitted are inserted into the boss15from the outside of the body11. Wires of the cable C1or C2, which are inserted into the body11through the through hole14of the boss, are connected to the screw terminals corresponding to the terminal box TB1or TB2arranged in the body11, respectively.

Secondly, the cap member35, through which the cable C1or C2are inserted, covers over the boss15in the state where the ring part33of the tension preventing ring32, through which the cable C1or C2are inserted, is in contact with the tip end surface of the boss15. Thus, the cap member35is fixed to the body11with the joint screws36inserted through the respective insertion holes35b. At this time, when the cap member35is pressed against the body11by tightening the joint screws36, an internal surface of the cap member35will push the tapered surfaces34bto deform the pressing pieces (pressing part)34inwardly (toward the cable C1or C2). Consequently, the claws34aof the pressing pieces34bite into the external shell40of the cable C1or C2, thereby restricting the movement of the external shell40in its axial direction. This reduces the tension applied to the connection portion of terminal box TB1or TB2when the cable C1or C2is pulled. Note that, on the tip end surface of the boss15, a plurality of projection parts15ais provided at regular intervals circumferentially. When depression parts33aprovided on the tension preventing ring32are engaged with the projection parts15a, the tension preventing ring32is prevented from rotating, thereby making it difficult to shift the positions of the pressing pieces34.

As described above, in the power supply control device of the present embodiment, the gap between the inner surface of the through hole14provided in the body11(body part) and the cable C1or C2is sealed with the sealing member30. Further, the outer restriction member31ais fitted on the cable C1or C2on an outer side than the sealing member30fitted on the cable C1or C2.

Since the outer restriction member31ais hardly deformed and keeps its original shape, the portion of the cable C1or C2on the outer side than the sealing member30, on which the outer restriction member31ais fitted, is also hardly bent. Even if the cable C1or C2drawn outside from the cap member35are bent by an external force, the outer restriction member31ainhibits the cable C1or C2from being bent, thereby making it difficult to bend the portion of the cable C1or C2on which the sealing member30is fitted. This enables to stabilize the contact condition between the sealing member30and the external shell40of the cable C1or C2, which improves the waterproof performance of the sealing member30.

Meanwhile, when the wires L1to L4introduced into the body11through the through hole14are bent within the body11for being connected to the terminal box TB1or TB2, the bending force is applied to a portion of the cable C1or C2on the inner side than the sealing member30. In the present embodiment, the inner restriction member31bis fitted on the portion of the cable C1or C2on the inner side than the sealing member30.

Since the inner restriction member31bis hardly deformed and keeps its original shape, the portion of the cable C1or C2on the inner side than the sealing member30, on which the inner restriction member31bis fitted, is also hardly bent. Even if the bending force is applied to the inner portion of the cable C1or C2, the inner restriction member31binhibits the cables C1or C2from being bent, thereby making it difficult to bend the portion of the cable C1or C2on which the sealing member30is fitted. This enables to stabilize the contact condition between the sealing member30and the external shell40of the cable C1or C2, which improves the waterproof performance of the sealing member30.

In the present embodiment, the restriction members for preventing the cables C1and C2from being bent are provided independently of the body part (body11), and include the restriction members31aand31bformed into a cylindrical shape of which inner diameter has the same dimension as the outer diameter of the respective cables C1and C2.

Accordingly, by inserting the cable C1or C2into the through hole14of the body11after passing the cable C1or C2through the sealing member30and the restriction members31aand31b, the sealing member30and the restriction members31aand31bcan be assembled into the body11. Therefore, the present embodiment is advantageously improved in assembly working efficiency as compared with the case where the sealing member30and the restriction members31aand31bare assembled independently.

Furthermore, in the present embodiment, the tension preventing ring32(tension preventing member), which receives an external force applied to each of the cables C1and C2, is further provided at a position on an outer side than the outer restriction member31a, which is located at a position on the outer side than the sealing member. The sealing member30, the restriction members31aand31b, and the tension preventing ring32are held in the body11(housing10) by the cap member35detachably attached to the body11.

Accordingly, an empty space near the through hole14can be enlarged within the housing10as compared with the case where the tension preventing member is disposed in the housing10. By utilizing the empty space, it becomes possible to accommodate excessive length of the electric wires connected to terminal boxes TB1and TB2, thereby enabling the housing10to be miniaturized as compared with the case where a separate space for accommodating the excessive length is provided. Since no tension preventing member exists in the space for accommodating the excessive length of the electric wires, the tension preventing member is avoided from being an obstacle in wiring work, thereby improving workability of the wiring work.

Still further, in the present embodiment, the tension preventing ring32serving as a tension preventing member, through which each of the cables C1and C2is inserted, includes a cylindrical member having the pressing pieces34(pressing part) that are held by the cap member35to press the external shell40. On the body11and the tension preventing ring32, there are respectively provided the depression-projection engaging parts engaged with each other in a circumferential direction of the cables C1and C2to prevent the tension preventing ring32from rotating. In the present embodiment, the depression-projection engaging parts includes: the projection parts15aprovided on the boss15of the body11; and the depression parts33aprovided on the tension preventing ring32and engaged with the projection parts15ato prevent the tension preventing ring32from rotating.

Since the depression parts33aon the tension preventing ring32and the projection parts15aon the boss15are engaged with each other to restrict the rotation of the tension preventing ring32, the cable C1or C2are hardly rotated even if an external force is applied so as to rotate the cable C1or C2. Accordingly, the contact condition between the sealing member30and the external shell40of the cable C1or C2is stabilized, which improves the waterproof performance of the sealing member30. Note that, the depression-projection engagement parts may include depression parts provided on the boss15and projection parts provided on the tension preventing ring32.

Meanwhile, in the present embodiment, alternating current power is supplied from an electric power system as the external power, but direct current power, for example, may be supplied from a solar cell and a fuel cell installed in a house.

Further, the control circuit4controls the ON/OFF operation of the relay2according to the control signal transmitted via the electric wire L4from the electric vehicle, but it is not necessary to adopt the configuration of communicating with the electric vehicle. For instance, the control circuit4may turn off the relay2automatically when predetermined time elapses after the relay2is turned on. Furthermore, a switch is provided in the housing10and an ON/OFF operation of the relay2may be controlled in accordance with the control signal inputted from the switch.