Conveyance system and power source plug

Abstract

To provide a conveyance system which can quickly shut off a power source when the system is abnormally heated.SOLUTION: A conveyance system is provided, which includes a conveyance device having an outlet and a power source plug. The power source plug comprises: a first terminal part; a second terminal part 312; a lead plate 330; a temperature fuse element 352 provided with a temperature fuse element 352c; an electric wire having a lead 361; and a conductive heat conducting plate 351 having a first heat conducting part H1 and a second heat conducting part H2. The first heat conducting part H1 is fixed to the second terminal part 312 in a state of being sandwiched between and in contact with the second terminal part 312 and the lead plate 330. The second heat conducting part H2 more protrudes in the first direction than the second terminal part 312, and the thermal fuse element 352 is disposed in the second heat conducting part H2.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a transport system and a power plug. [Background technology]

[0002] Known examples of conventional power plugs (also called charging plugs) include those described in Patent Documents 1 and 2. Patent Document 1 describes a spark prevention structure for a plug in which a resistor made of a coiled elastic body is placed in the gap between the outlet terminal of the outlet and the charging plug terminal of the charging plug. With this structure, current flows through the resistor, preventing sparks from occurring when the charging plug is inserted.

[0003] However, because the gap between the outlet terminal and the charging plug terminal is generally narrow, it is difficult to place a resistor made of a coiled elastic body in that gap. Therefore, the spark prevention structure for a plug described in Patent Document 1 requires significant changes to the design of the outlet terminal and / or the charging plug terminal in order to install a resistor made of a coiled elastic body, which increases costs. Furthermore, resistors have the problem of being unable to shut off the power supply (electric power transmitted from the charging plug to the outlet) if abnormal overheating occurs at the contact point between the outlet terminal and the charging plug terminal.

[0004] Patent Document 2 describes a charging plug in which a fuse is interposed in an electric wire that connects a charging plug terminal and a power cable. The electric wire includes a first electric wire that extends from inside the power cable and is connected to one end of the fuse, and a second electric wire that connects the other end of the fuse and the charging plug terminal. In the charging plug described in Patent Document 2, the fuse is covered with an insulating member, which protects the fuse that is provided between the electric wires extending from the power cable and makes it easy to handle the power cable.

[0005] However, in the charging plug described in Patent Document 2, if abnormal overheating occurs at the contact point between the outlet terminal and the charging plug terminal, there is a delay in heat conduction because the fuse is far from the contact point. As a result, there is a delay in the operation of the fuse, and the connector housing (resin case) near the contact point may melt before the fuse operates, and in some cases, may ignite. In other words, the fuse of the charging plug described in Patent Document 2 has a problem in that it cannot immediately cut off the power supply in the event of abnormal overheating, which causes a sudden temperature rise.

[0006] One possible method for arranging the fuse is to place it directly in the resin case that holds the charging plug terminal. However, because the resin case has limited space for arranging the fuse, it may not be possible to place the fuse depending on its size. Even if the fuse could be placed, the wires between the charging plug terminal and the fuse, and between the fuse and the power cable, would be bulky near the resin case, so it would be necessary to secure space for the wires near the resin case. Furthermore, because the resin case has low thermal conductivity, the responsiveness of the fuse is reduced, which, like the charging plug described in Patent Document 2, results in the problem of not being able to immediately shut off the power supply in the event of abnormal overheating. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 4-185235 [Patent Document 2] International Publication No. 2017 / 149763 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transport system and a power plug that can quickly shut off the power supply in the event of abnormal overheating. [Means for solving the problem]

[0009] In order to solve the above problems, the conveyance system according to the present invention comprises: a conveying device having an outlet; a power plug connected to a power cable for connecting to an external power source and configured to be able to fit into the outlet; A transport system comprising: The power plug is a first terminal portion that contacts a socket terminal of the socket; a second terminal portion connected to the first terminal portion and extending in a first direction; a lead plate connected to the second terminal portion; a thermal fuse substrate provided with a thermal fuse element connected to the lead plate; an electric wire connecting the thermal fuse element and the power cable; a conductive heat conduction plate having a first heat conduction portion and a second heat conduction portion; Equipped with the first thermally conductive portion is fixed to the second terminal portion in a state of being sandwiched between and in contact with the second terminal portion and the lead plate; The second thermally conductive portion protrudes in the first direction beyond the second terminal portion, and the thermal fuse substrate is disposed on the second thermally conductive portion.

[0010] In the transport system, The second heat conducting portion of the heat conducting plate and the lead plate can be configured to be fixed to the second terminal portion by a metal screw.

[0011] In the transport system, the heat conduction plate is a metal plate, The lead plate may be configured to have a bent portion at a position corresponding to a boundary between the first thermally conductive portion and the second thermally conductive portion.

[0012] In the transport system, The heat conduction plate is a first metal plate having the first thermally conductive portion and the second thermally conductive portion; The heat-transmitting element may be configured to include a second metal plate having only the first thermally conductive portion and sandwiched between the first metal plate and the lead plate.

[0013] In the transport system, The power plug can be configured to include three first terminal portions, three second terminal portions, three lead plates, the thermal fuse board, the electric wires, and the thermal conduction plates, each corresponding to the R phase, S phase, and T phase of three-phase AC.

[0014] In the transport system, the transport device is a mobile transport device, The mobile transport device may be configured to include at least one forklift.

[0015] In the transport system, the conveying device is a stationary conveying device, The stationary transport device may be configured to include at least one transport conveyor.

[0016] In order to solve the above problems, the power plug according to the present invention comprises: A power plug configured to be connected to a power cable and to be able to fit into a power outlet having a power outlet terminal, a first terminal portion that contacts the outlet terminal; a second terminal portion connected to the first terminal portion and extending in a first direction; a lead plate connected to the second terminal portion; a thermal fuse substrate provided with a thermal fuse element connected to the lead plate; an electric wire connecting the thermal fuse element and the power cable; a conductive heat conduction plate having a first heat conduction portion and a second heat conduction portion; Equipped with the first thermally conductive portion is fixed to the second terminal portion in a state of being sandwiched between and in contact with the second terminal portion and the lead plate; The second thermally conductive portion protrudes in the first direction beyond the second terminal portion, and the thermal fuse substrate is disposed on the second thermally conductive portion. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a charging system for a battery vehicle that can quickly cut off power in the event of abnormal overheating. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram showing a charging system for a battery vehicle according to the present invention; [Figure 2] 1 is a diagram showing a charging plug of the present invention. [Figure 3] 1 is a diagram showing the relationship between a charging plug terminal and a power outlet terminal according to the present invention; [Figure 4] 1A is a plan view showing a fuse portion of the present invention, and FIG. 1B is a cross-sectional view taken along line AA' of FIG. [Figure 5] 10A and 10B are diagrams illustrating the flow of heat conduction in a fuse portion of the present invention. [Figure 6] FIG. 10 is a diagram showing a temperature gradient for explaining the effect of the present invention. [Figure 7] 1A is a plan view showing a fuse portion of a modified example, and FIG. 1B is a cross-sectional view taken along line AA' of FIG. [Figure 8] 1 is a diagram showing a power supply system for a conveyor according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a transport system and a power plug according to the present invention will be described with reference to the accompanying drawings.

[0020] [First embodiment] In the first embodiment, a battery vehicle charging system 100 shown in Fig. 1 will be described as an example of a transport system according to the present invention. The battery vehicle charging system 100 is composed of at least one forklift 200 (corresponding to the "mobile transport device" of the present invention) and at least one charging plug 300 with a power cable.

[0021] In this embodiment, the forklift 200 is a reach-type forklift, but it may also be a counterbalance-type forklift or another type of forklift. Also, in this embodiment, the forklift 200 is a manned forklift driven by an operator, but it may also be an unmanned forklift that is capable of self-driving.

[0022] The forklift 200 includes a vehicle body 201. A pair of left and right straddle legs 202 and a load handling device 203 are provided at the front of the vehicle body 201. The load handling device 203 includes a mast 204 that is provided so as to be movable in the front-rear direction along the straddle legs 202, and forks 205 that are provided on the mast 204 so as to be able to rise and fall. The load handling device 203 may include another attachment in addition to or instead of the forks 205.

[0023] A driver's seat 206 in which an operator sits while standing is provided on the right side of the rear of the vehicle body 201. An operation unit 207 including an accelerator lever and various operation levers for the cargo handling device 203 is provided in front of the driver's seat 206. A steering handle 208 for steering is provided on the left side of the driver's seat 206. A head guard 209 is provided above the driver's seat 206. An outlet 210 is provided on the side wall of the driver's seat 206. The outlet 210 can be provided at any position on the vehicle body 201.

[0024] 3, the outlet 210 includes a resin terminal block 210a and a plurality of outlet terminals 210b protruding from the terminal block 210a. As long as the surface of the terminal block 210a facing the outlet terminals 210b is exposed from the vehicle body 201, the remaining portion of the terminal block 210a may be housed inside the vehicle body 201. The plurality of outlet terminals 210b include three outlet terminals 210b compatible with three-phase (R phase, S phase, T phase) AC power, and an outlet-side earth terminal (not shown).

[0025] As shown in Fig. 1, a battery 211 and an on-board charger 212 are provided inside a vehicle body 201. In this embodiment, the battery 211 is a lead battery, but it may be a lithium-ion battery or another type of battery. The on-board charger 212 charges the battery 211 using power input to an outlet 210. In this embodiment, three-phase (R-phase, S-phase, T-phase) AC power is input to the outlet 210, and the on-board charger 212 converts this AC power into DC power and supplies it to the battery 211.

[0026] Charging plug 300 with power cable includes charging plug 301 (corresponding to the "power plug" of the present invention) and power cable 302. Charging plug 301 is configured to be able to fit into outlet 210. Power cable 302 is configured to be able to connect to an external power source (in this embodiment, a three-phase AC power source provided in a facility such as a factory or warehouse). Power cable 302 may be configured as a single power cable or as a combination of multiple connected power cables.

[0027] 2 shows the internal structure of charging plug 301. Charging plug 301 includes multiple charging plug terminals 310, a resin case 320, multiple lead plates 330, multiple screws 340, multiple fuse portions 350, multiple electric wires 360, and a cover body 370 that houses these components.

[0028] The multiple charging plug terminals 310 include three charging plug terminals 310 corresponding to the three phases (R phase, S phase, and T phase) and a charging plug-side ground terminal (not shown) corresponding to the outlet-side ground terminal. As shown in Fig. 3, the charging plug terminal 310 includes a first terminal portion 311 and a second terminal portion 312 that are integrally formed.

[0029] First terminal portion 311 is formed in a cylindrical shape so as to fit into outlet terminal 210b. First terminal portion 311 has inner circumferential surface 311a and inner end surface 311b. When fitting into outlet 210, inner circumferential surface 311a of first terminal portion 311 contacts the outer circumferential surface of outlet terminal 210b and / or inner end surface 311b of first terminal portion 311 contacts the tip surface of outlet terminal 210b.

[0030] The second terminal portion 312 protrudes in the first direction from the resin case 320. The second terminal portion 312 is formed in a rectangular parallelepiped shape, and is formed with a fixing hole (not shown) for fixing the screw 340. In this embodiment, the second terminal portion 312 is formed integrally with the first terminal portion 311 and is made of the same metal material as the first terminal portion 311. Note that the second terminal portion 312 may be formed separately from the first terminal portion 311, or may be made of a metal material different from that of the first terminal portion 311, as long as it is connected to the first terminal portion 311.

[0031] Resin case 320 is a case made of resin (e.g., epoxy resin) and corresponds to an "insulating case" of the present invention. Resin case 320 includes case main body 321 and wall 322. Case main body 321 houses and holds first terminal 311, while exposing second terminal 312 from case main body 321. Wall 322 protrudes in the first direction from case main body 321 so as to be disposed between three second terminals 312. Wall 322 is provided to ensure a creepage distance between second terminals 312 and to reliably insulate fuse portions 350 from each other. Note that if the spacing between second terminals 312 is relatively large, resin case 320 does not need to include wall 322 as long as it includes case main body 321.

[0032] 2, the plurality of lead plates 330 includes three lead plates 330 corresponding to the three phases (R phase, S phase, and T phase). The lead plates 330 are conductive metal plates, and electrically connect the charging plug terminal 310 and the fuse portion 350.

[0033] The plurality of screws 340 includes at least three metal screws 340. Screws 340 are fixing means for fixing second terminal portion 312 of charging plug terminal 310, copper plate 351 (described later), and lead plate 330 in a stacked state. Note that fixing means is not limited to screws 340, and fixing means other than screws 340 may also be used.

[0034] The multiple fuse units 350 include three fuse units 350 corresponding to the three phases (R phase, S phase, and T phase). Note that, since no current normally flows through the charging plug's earth terminal, there is no need for a fuse unit 350 connected to the charging plug's earth terminal.

[0035] Fig. 4(A) shows a plan view of fuse section 350, and Fig. 4(B) shows a cross-sectional view taken along line A-A' in Fig. 4(A). As shown in Fig. 4(A) and Fig. 4(B), fuse section 350 includes copper plate 351, which corresponds to the "thermal conduction plate" of the present invention, and thermal fuse substrate 352.

[0036] Copper plate 351 is at least one flat plate (one plate in this embodiment) made of copper, and has a first thermally conductive portion H1 and a second thermally conductive portion H2. First thermally conductive portion H1 is a portion sandwiched between second terminal portion 312 of charging plug terminal 310 and lead plate 330. Second thermally conductive portion H2 is a portion that protrudes in the first direction beyond second terminal portion 312.

[0037] The first thermally conductive portion H1 is fixed to the second terminal portion 312 with screws 340 while in direct contact with the second terminal portion 312 and the lead plate 330. A thermal fuse board 352 is mounted on the upper surface of the second thermally conductive portion H2. An end of the second thermally conductive portion H2 protrudes in the first direction beyond an end of a thermal fuse element 352c (described later). In this embodiment, the widthwise dimension of the second thermally conductive portion H2 is the same as the widthwise dimension of the first thermally conductive portion H1, but the two may be different. Similarly, the thicknesswise dimension of the second thermally conductive portion H2 is the same as the thicknesswise dimension of the first thermally conductive portion H1, but the two may be different.

[0038] The thermal fuse substrate 352 is an insulating substrate and has a first surface (lower surface) and a second surface (upper surface) that face each other. The first surface of the thermal fuse substrate 352 is fixed to the upper surface of the second thermally conductive portion H2 of the copper plate 351 with an adhesive. A first electrode 352a, a second electrode 352b, a thermal fuse element 352c, and a sealing resin 352d are provided on the second surface of the thermal fuse substrate 352. In this embodiment, the width of the thermal fuse substrate 352 is larger than the width of the copper plate 351, but may be smaller than the width of the copper plate 351.

[0039] The first electrode 352a is formed on the right side of the second surface of the thermal fuse substrate 352 and is connected to the lead plate 330 by soldering. The lead plate 330 has a bent portion bent in the thickness direction, making it connectable to the first electrode 352a. In this embodiment, the bent portion is formed close to the side surface of the thermal fuse substrate 352 (at a position corresponding to the boundary between the first thermal conductive portion H1 and the second thermal conductive portion H2), so that the lead plate 330 can maximize the contact surface with the copper plate 351, thereby improving thermal conductivity.

[0040] The second electrode 352b is formed on the left side of the second surface of the thermal fuse substrate 352, and is connected to a lead 361 provided at the tip of the electric wire 360 ​​by soldering.

[0041] The thermal fuse element 352c is composed of a fusible alloy and a special resin (flux) that coats the fusible alloy. One end is connected to the first electrode 352a and the other end is connected to the second electrode 352b. When the temperature of the fusible alloy in the thermal fuse element 352c exceeds a predetermined threshold (melting point), the fusible alloy melts and cuts off the electrical connection between the first electrode 352a and the second electrode 352b. In other words, the thermal fuse element 352c can cut off the power supply in the event of abnormal overheating. Any known fusible alloy type fuse element can be used as the thermal fuse element 352c. Alternatively, any known thermal pellet type fuse element may be used instead of the fusible alloy type.

[0042] The sealing resin 352d is intended to protect the thermal fuse element 352c and the like. More specifically, the sealing resin 352d contains a special resin (flux) that maintains the performance of the fusible alloy that constitutes the thermal fuse element 352c. The sealing resin 352d is provided on the entire second surface of the thermal fuse substrate 352, and covers the thermal fuse element 352c, the connection portion between the first electrode 352a and the lead plate 330, and the connection portion between the second electrode 352b and the lead 361. In this embodiment, the sealing resin 352d is an epoxy resin.

[0043] In addition, the charging plug 301 of this embodiment has three insulating coating parts (e.g., insulating tubes) corresponding to the three phases (R phase, S phase, and T phase), and it is preferable that each insulating coating part covers the temperature fuse substrate 352 and the second thermal conductive part H2 of the copper plate 351.

[0044] 2, the plurality of electric wires 360 includes at least three electric wires 360 corresponding to three phases (R phase, S phase, and T phase). The electric wires 360 are electric wires drawn from the power cable 302 into the cover body 370.

[0045] Cover body 370 houses charging plug terminal 310, resin case 320, lead plate 330, screws 340, fuse section 350, and electric wire 360. Cover body 370 has a gripping section 371 that can be gripped by an operator. In this embodiment, cover body 370 is made of a transparent material, but it may also be made of an opaque material.

[0046] Next, the flow of power in battery vehicle charging system 100 will be described. In battery vehicle charging system 100, when power cable 302 is connected to an external power source, power supplied from the external power source flows via power cable 302, through charging plug 301, outlet 210, and on-board charger 212, and is then supplied to battery 211. Power in charging plug 301 flows through electric wire 360 ​​(lead 361), second electrode 352b, thermal fuse element 352c, first electrode 352a, lead plate 330, copper plate 351, and charging plug terminal 310, and is then supplied to outlet terminal 210b of outlet 210. Here, poor contact between charging plug terminal 310 and outlet terminal 210b, for example, may cause abnormal overheating at the contact point between charging plug terminal 310 and outlet terminal 210b.

[0047] FIG. 5 shows an example of the flow of heat conduction from the abnormally overheated portion of the charging plug terminal 310. Heat generated at the abnormally overheated portion of the charging plug terminal 310 is conducted from the second terminal portion 312 of the charging plug terminal 310 to the copper plate 351. Heat from the first thermally conductive portion H1 of the copper plate 351 is conducted from the second surface (top surface) of the thermal fuse substrate 352 via the lead plate 330 to the thermal fuse element 352c. At the same time, heat from the second thermally conductive portion H2 of the copper plate 351 is conducted from the first surface (bottom surface) of the thermal fuse substrate 352 to the thermal fuse element 352c. In other words, heat is conducted from the top and bottom surfaces of the thermal fuse substrate 352 to the thermal fuse element 352c. Moreover, because the copper plate 351 has high thermal conductivity, heat generated at the contact portion of the charging plug terminal 310 with the outlet terminal 210b is quickly conducted to the thermal fuse element 352c. Therefore, in the event of abnormal overheating, the thermal fuse element 352c can be quickly melted down, and the power supply can be quickly cut off.

[0048] FIG. 6 shows examples of temperature gradients A to E during abnormal overheating. A is the temperature gradient in the sealing resin 352d of this embodiment. B is the temperature gradient in the thermal fuse element 352c of this embodiment. C is the temperature gradient in the thermal fuse element 352c of the comparative example. D is the temperature gradient in the sealing resin 352d of the conventional example. E is the temperature gradient in the thermal fuse element 352c of the conventional example.

[0049] Here, the comparative example has the same configuration as this embodiment except that it does not include the copper plate 351. The conventional example has the same configuration as this embodiment except that it does not include the copper plate 351, that the thermal fuse substrate 352 is disposed on the outer peripheral surface of the resin case 320, and that a lead and an electric wire are used instead of the lead plate 330. The temperature gradient in the sealing resin 352d is the temperature gradient at the right end of the sealing resin 352d (near the connection portion between the first electrode 352a and the lead plate 330). The temperature gradient in the sealing resin 352d of the comparative example is almost the same as the temperature gradient A in the sealing resin 352d of this embodiment, so it is not shown in the figures.

[0050] In Figure 6, temperature T1 is the melting point of the fusible alloy that constitutes the thermal fuse element 352c, and at temperature T1, the thermal fuse element 352c melts. Temperature T2 is the heat resistance temperature of the resin (epoxy resin) that constitutes the sealing resin 352d, and at temperature T2, the sealing resin 352d deforms (including softening and deterioration). If the sealing resin 352d deforms, for example, the enclosed special resin (flux) may leak out. As a result, the fusible alloy of the thermal fuse element 352c cannot be melted.

[0051] In any of the present embodiment, the comparative example, and the conventional example, the temperature gradient in the sealing resin 352d is greater than the temperature gradient in the thermal fuse element 352c. This is because the sealing resin 352d is closer to the abnormally overheated area than the thermal fuse element 352c, and the heat generated in the abnormally overheated area is transferred to the sealing resin 352d first.

[0052] In the conventional example, if abnormal overheating occurs at the contact point between the charging plug terminal 310 and the outlet terminal 210b at time t0, heat is transferred to the sealing resin 352d and the thermal fuse element 352c through the resin case 320, which has low thermal conductivity. As a result, the temperatures of the sealing resin 352d and the thermal fuse element 352c rise slowly, as shown by temperature gradients D and E. As a result, in the conventional example, the operation of the thermal fuse element 352c is delayed (the thermal fuse element 352c melts at time t4). Therefore, in the conventional example, the resin case 320 near the contact point may melt and possibly catch fire before the time t4 at which the thermal fuse element 352c melts. Note that in the conventional example, the temperature of the sealing resin 352d reaches temperature T2 at time t5, which is later than time t4, so there is no problem of the sealing resin 352d deforming before the thermal fuse element 352c melts.

[0053] In the comparative example, the sealing resin 352d and the thermal fuse element 352c are located near the abnormally overheated area, so the temperatures of the sealing resin 352d and the thermal fuse element 352c rise more rapidly than in the conventional example, as shown by temperature gradients A and C. However, in the comparative example, the copper plate 351 is not provided, so heat is conducted to the thermal fuse element 352c only from the upper surface of the thermal fuse substrate 352, and not from the lower surface of the thermal fuse substrate 352. Therefore, as shown by temperature gradients A and C, the difference between the temperature gradients of the sealing resin 352d and the thermal fuse element 352c becomes large. As a result, in the comparative example, the temperature of the sealing resin 352d reaches temperature T2 (time t2) before time t3, when the thermal fuse element 352c melts. That is, in the comparative example, the sealing resin 352d deforms, causing the enclosed special resin (flux) to leak, which could prevent the thermal fuse element 352c from operating (melting).

[0054] In this embodiment, the copper plate 351 is fixed to the second terminal 312 by the screw 340 while in direct contact with the second terminal 312 and the lead plate 330, so that heat is quickly conducted to the thermal fuse element 352c from the underside of the thermal fuse substrate 352. As a result, the temperature gradient B in the thermal fuse element 352c approaches the temperature gradient A, and the thermal fuse element 352c can be blown at time t1, before time t2 when the temperature of the sealing resin 352d reaches temperature T2. In other words, this embodiment can avoid the problem of the conventional example of delayed operation of the thermal fuse element 352c, and can also avoid the problem of the comparative example of leakage of the special resin (flux) due to deformation of the sealing resin 352d.

[0055] As described in Patent Document 2, when a fuse is provided between the electric wires 360, the fuse is located far from the contact point, causing a delay in heat conduction and a small temperature gradient, as in the conventional example. As a result, the resin case near the contact point may melt before the fuse element blows, possibly resulting in a fire.

[0056] In conclusion, the battery vehicle charging system 100 according to this embodiment has a copper plate 351 with high thermal conductivity that is in direct contact with the second terminal 312 and the lead plate 330, and a thermal fuse substrate 352 disposed on the copper plate 351. This improves the responsiveness and stability of the thermal fuse element 352c. Specifically, this avoids operational delays in the thermal fuse element 352c and prevents leakage of the special resin (flux) due to deformation of the sealing resin 352d. As a result, melting of the resin case 320 in the event of abnormal overheating can be avoided, or the amount of melting of the resin case 320 can be significantly reduced, thereby reliably preventing ignition at the contact point between the charging plug terminal 310 and the outlet terminal 210b and the spread of fire to the body 201 of the forklift 200. In other words, the battery vehicle charging system 100 ensures safety during charging of the battery 211.

[0057] Furthermore, since fuse portion 350 of this embodiment fits between wall portions 322 of resin case 320 (see FIG. 2), space can be saved and it can be easily applied to existing charging plugs.

[0058] [Modification of the first embodiment] In the battery vehicle charging system 100 of the above embodiment, instead of the lead plate 330, a lead plate 330' and a spacer 351' may be used as shown in FIG.

[0059] The lead plate 330' has the same structure as the lead plate 330, except that it does not have a bent portion bent in the thickness direction.

[0060] Spacer 351' is at least one flat plate (one plate in this modification) made of metal (e.g., copper). Spacer 351' is sandwiched between lead plate 330' and first thermally conductive portion H1 of copper plate 351. Copper plate 351 has first thermally conductive portion H1 and second thermally conductive portion H2, and therefore corresponds to the "first metal plate" of the present invention, while spacer 351' has only first thermally conductive portion H1, and therefore corresponds to the "second metal plate" of the present invention.

[0061] The spacer 351' is fixed to the second terminal portion 312 by the screw 340 while in direct contact with the lead plate 330' and the copper plate 351. The widthwise dimension of the spacer 351' is the same as the widthwise dimension of the lead plate 330' and the copper plate 351, but may be different. The thicknesswise dimension of the spacer 351' can be changed as appropriate depending on the thicknesswise dimension of the thermal fuse substrate 352.

[0062] In this modification, the thermal fuse element 352c can be quickly melted down in the event of abnormal overheating, thereby quickly cutting off the power supply, just as in the battery vehicle charging system 100 of the above embodiment. Note that in this modification, the copper plate 351 and the spacer 351' are formed as separate bodies, but since they are made of the same copper, they may be formed as an integrated body.

[0063] [Second embodiment] In the second embodiment, a conveyor power supply system 400 shown in Fig. 8 will be described as an example of a conveying system according to the present invention. The conveyor power supply system 400 is composed of at least one transport conveyor 500 (corresponding to the "stationary conveying device" of the present invention) and at least one power plug 600 with a power cable.

[0064] The transport conveyor 500 includes a conveyor main body 501, a conveyor control unit 502, and a power outlet 503. The power plug with power cable 600 includes a power plug 601 and a power cable 602.

[0065] The conveyor main body 501 includes a conveyor belt, multiple conveyor rollers, and a housing. The conveyor belt rotates in a first direction when the multiple conveyor rollers rotate in a first direction, and rotates in a second direction when the multiple conveyor rollers rotate in a second direction opposite to the first direction. The housing is configured to rotatably hold the conveyor belt and multiple conveyor rollers as described above. The housing includes legs (not shown) for installing the transport conveyor 500 in a facility such as a factory or warehouse.

[0066] The conveyor control unit 502 is configured to control the conveyor main body 501. The conveyor control unit 502 includes, for example, a motor for rotating the conveyor roller and a drive circuit for driving the motor. The drive circuit drives the motor based on AC power supplied to the outlet 503, and the motor rotates the conveyor roller in a first direction or a second direction. Specifically, the direction of rotation of the conveyor roller changes depending on the orientation of the power plug 601. When the power plug 601 is inserted into the outlet 503 with its top surface facing up, the conveyor roller rotates in the first direction, and when the power plug 601 is inserted into the outlet 503 with its top surface facing down, the conveyor roller rotates in the second direction.

[0067] The outlet 503 has the same configuration as the outlet 210 of the first embodiment, except that it is provided with two ground terminals (not shown). That is, the outlet 503 includes three outlet terminals compatible with three-phase (R phase, S phase, T phase) AC power, and two ground terminals provided on both the left and right sides thereof.

[0068] The power plug 601 has the same configuration as the charging plug 301 of the first embodiment, except that the cover does not have a gripping portion and has two ground terminals. The power plug 601 includes three power plug terminals (with the same configuration as the charging plug terminals 310) corresponding to the three phases (R phase, S phase, and T phase) and two ground terminals (with the same configuration as the charging plug ground terminals) provided on both the left and right sides. The power cable 602 has the same configuration as the power cable 302 of the first embodiment. Below, the same reference symbols as in the first embodiment are used for the components of the power plug 601.

[0069] According to the conveyor power supply system 400 of this embodiment, the power plug 601 has a copper plate 351 with high thermal conductivity that is in direct contact with the second terminal 312 and the lead plate 330, and the thermal fuse substrate 352 is mounted on the copper plate 351. This improves the responsiveness and stability of the thermal fuse element 352c. Specifically, this prevents operational delays in the thermal fuse element 352c and prevents leakage of the special resin (flux) due to deformation of the sealing resin 352d. As a result, melting of the resin case 320 in the event of abnormal overheating can be prevented, or the amount of melting of the resin case 320 can be significantly reduced. This reliably prevents fire at the contact point between the power plug terminal and the outlet terminal, and the spread of fire to the conveyor control unit 502 or the conveyor main body 501. In other words, the conveyor power supply system 400 ensures safety when supplying power to the transport conveyor 500.

[0070] Note that a configuration according to a modification of the first embodiment can also be applied to the power plug 601. Furthermore, if the conveyor belt rotates only in one of the first and second directions, the power plug 601 only needs to have one ground terminal, and the outlet 503 only needs to have one ground terminal.

[0071] Although the embodiments of the transport system and power plug according to the present invention have been described above, the present invention is not limited to the above-described embodiments.

[0072] [Other variations] The transport system of the present invention is a transport system including a transport device having an outlet, and a power plug connected to a power cable for connecting to an external power source and configured to be able to fit into the outlet, wherein the power plug has a first terminal portion that contacts the outlet terminal of the outlet, a second terminal portion that is connected to the first terminal portion and extends in a first direction, a lead plate connected to the second terminal portion, a temperature fuse board on which a temperature fuse element is connected to the lead plate, an electric wire that connects the temperature fuse element to the power cable, and a conductive heat conduction plate having a first heat conduction portion and a second heat conduction portion, wherein the first heat conduction portion is fixed to the second terminal portion while being sandwiched and in contact with the second terminal portion and the lead plate, and the second heat conduction portion protrudes in the first direction beyond the second terminal portion, and the temperature fuse board is arranged, and the configuration can be modified as appropriate.

[0073] The power plug of the present invention is a power plug that is connected to a power cable and is configured to be able to fit into a socket having a socket terminal, and includes a first terminal portion that contacts the socket terminal, a second terminal portion that is connected to the first terminal portion and extends in a first direction, a lead plate connected to the second terminal portion, a temperature fuse board on which a temperature fuse element is connected to the lead plate, an electric wire that connects the temperature fuse element to the power cable, and a conductive heat conduction plate having a first heat conduction portion and a second heat conduction portion, wherein the first heat conduction portion is fixed to the second terminal portion while being sandwiched and in contact with the second terminal portion and the lead plate, and the second heat conduction portion protrudes in the first direction beyond the second terminal portion, and the configuration can be modified as appropriate as long as a temperature fuse board is arranged.

[0074] The heat conducting plate may be any plate that is electrically conductive and has a certain degree of thermal conductivity. For example, a metal plate other than copper may be used as the heat conducting plate.

[0075] The mobile transport device may be a battery vehicle that moves by battery power. The battery vehicle may include vehicles other than forklifts, such as transport vehicles, construction machinery, or agricultural machinery. [Explanation of symbols]

[0076] 100 Battery Car Charging System 200 forklifts 201 Body 202 Straddle Leg 203 Cargo handling equipment 204 Mast 205 Fork 206 Driver's seat 207 Operation section 208 Steering Wheel 209 Head Guard 210 outlets 211 Battery 212 On-board charger 300 Power cable with charging plug 301 Charging plug 302 Power cable 310 Charging plug terminal 311 1st terminal section 312 2nd terminal section 320 Resin Case 321 Case body 322 Wall 330 Reed Plate 350 Fuse section 351 Copper plate 351' spacer 352 Thermal fuse board 360 electric wire 361 leads 370 Cover body 371 Gripping part 400 Conveyor Power Supply System 500 conveyor 501 Conveyor body 502 Conveyor control unit 503 Outlet 600 Power plug with power cable 601 Power plug 602 Power Cable

Claims

1. a conveying device having an outlet; a power plug connected to a power cable for connecting to an external power source and configured to be able to fit into the outlet; A transport system comprising: The power plug is a first terminal portion that contacts a socket terminal of the socket; a second terminal portion connected to the first terminal portion and extending in a first direction; a lead plate connected to the second terminal portion; a thermal fuse substrate provided with a thermal fuse element connected to the lead plate; an electric wire connecting the thermal fuse element and the power cable; an electrically conductive heat conduction plate having a first heat conduction portion and a second heat conduction portion; Equipped with the first heat conducting portion is fixed to the second terminal portion in a state of being sandwiched between and in contact with the second terminal portion and the lead plate; The second thermal conductive portion protrudes in the first direction beyond the second terminal portion, and the thermal fuse substrate is disposed on the second thermal conductive portion. A transport system characterized by:

2. The second heat conducting portion of the heat conducting plate and the lead plate are fixed to the second terminal portion by metal screws.

2. The transport system according to claim 1.

3. the heat conduction plate is a single metal plate, The lead plate has a bent portion at a position corresponding to a boundary between the first heat conducting portion and the second heat conducting portion.

2. The transport system according to claim 1.

4. The heat conduction plate is a first metal plate having the first thermally conductive portion and the second thermally conductive portion; a second metal plate having only the first heat conducting portion and sandwiched between the first metal plate and the lead plate; 2. The transport system according to claim 1.

5. The power plug includes three first terminals, three second terminals, three lead plates, a thermal fuse board, an electric wire, and a thermal conduction plate, each of which corresponds to an R phase, an S phase, and a T phase of a three-phase AC.

2. The transport system according to claim 1.

6. the transport device is a mobile transport device, The mobile transport device includes at least one forklift.

2. The transport system according to claim 1.

7. the conveying device is a stationary conveying device, The stationary transport device includes at least one transport conveyor.

2. The transport system according to claim 1.

8. A power plug configured to be connected to a power cable and to be able to fit into a power outlet having a power outlet terminal, a first terminal portion that contacts the outlet terminal; a second terminal portion connected to the first terminal portion and extending in a first direction; a lead plate connected to the second terminal portion; a thermal fuse substrate provided with a thermal fuse element connected to the lead plate; an electric wire connecting the thermal fuse element and the power cable; an electrically conductive heat conduction plate having a first heat conduction portion and a second heat conduction portion; Equipped with the first heat conducting portion is fixed to the second terminal portion in a state of being sandwiched between and in contact with the second terminal portion and the lead plate; The second thermal conductive portion protrudes in the first direction beyond the second terminal portion, and the thermal fuse substrate is disposed on the second thermal conductive portion. A power plug characterized by:

Images