Stationary battery charger

Abstract

To provide a stationary charger capable of automatically stopping charging when a plug terminal is abnormally overheated.SOLUTION: A stationary battery charger 100 includes an AC plug 110, an AC cable 120, a battery charger main body 130 that converts AC power into DC power and outputs the DC power, a DC cable 140, and a DC plug 150, and further includes temperature fuses TF1 and TF2 connected to plug terminals 151 of the DC plug 150 in a thermally conductive manner and signal lines L1 to L3 in which the temperature fuses TF2 and are interposed, and the battery charger main body 130 detects operation of the temperature fuses L1 and L3 via the signal lines TF1 to and stops output of the DC power. TF2 TF1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stationary charger for charging a cargo handling vehicle such as a forklift. [Background technology]

[0002] Stationary chargers have been known for some time that supply DC power to batteries mounted on forklifts to charge the batteries. However, conventional stationary chargers generally cannot automatically stop charging if the plug terminals connected to the forklift overheat abnormally.

[0003] A known charging plug is equipped with a label that changes color in the event of abnormal overheating (see, for example, Patent Document 1). With the charging plug described in Patent Document 1, a forklift operator can visually recognize the discoloration of the label in the event of abnormal overheating, enabling early detection of abnormal overheating of the plug terminals. However, even with the charging plug described in Patent Document 1, it is not possible to automatically stop charging in the event of abnormal overheating of the plug terminals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-201461 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stationary charger that can automatically stop charging when the plug terminals abnormally overheat. [Means for solving the problem]

[0006] In order to solve the above problems, the stationary charger according to the present invention comprises: an AC plug to be connected to an AC power source; an AC cable having one end connected to the AC plug and transmitting AC power supplied from the AC power supply; a charger main body to which the other end of the AC cable is connected, which converts the AC power supplied via the AC cable into DC power and outputs the DC power; a DC cable having one end connected to the charger main body and transmitting the DC power; a DC plug including a plug terminal, one side of which is connected to the other end of the DC cable and the other side of which is connected to a power outlet of a cargo handling vehicle, and an insulating case that houses the plug terminal; A stationary charger comprising: a thermal fuse connected to the plug terminal in a thermally conductive manner; a signal line having the thermal fuse interposed therein and wired from the charger main body to the charger main body via the DC plug, The charger main body includes: The operation of the thermal fuse is detected via the signal line, and the output of the DC power is stopped.

[0007] In the stationary charger, the thermal fuse is connected to the plug terminal via a metal terminal; The metal terminal is The thermal fuse may have a mounting portion on one side on which the thermal fuse is mounted and a rod portion on the other side, the rod portion being configured to be connected to the plug terminal.

[0008] In the stationary charger, The arrangement portion of the metal terminal is The thermal fuse is formed in a cylindrical shape, and the thermal fuse is disposed inside the cylindrical shape. The rod portion of the metal terminal is The DC cable may be configured to be crimped to the plug terminal together with the electric wires of the DC cable.

[0009] In the stationary charger, The plug terminal is It has a positive plug terminal and a negative plug terminal, The thermal fuse is a positive electrode side thermal fuse connected to the positive electrode side plug terminal in a thermally conductive manner; a negative electrode thermal fuse connected to the negative electrode plug terminal in a thermally conductive manner, The positive electrode side thermal fuse and the negative electrode side thermal fuse are It can be configured to be inserted in series into the signal line.

[0010] In the stationary charger, The charger main body includes: Transformer and a switch circuit that is provided on a primary side of the transformer, and that supplies the AC power to the transformer when in an ON state and cuts off the supply of the AC power to the transformer when in an OFF state; a rectifier circuit provided on the secondary side of the transformer; a control circuit that controls the on state and the off state of the switch circuit, the signal line is connected to the control circuit; The control circuit The output of the DC power can be stopped by turning the switch circuit off.

[0011] In the stationary charger, the switch circuit includes a magnetic switch; The magnetic switch is a switch unit that switches between the on state and the off state; a coil unit that turns the switch unit to the on state when a current is flowing and turns the switch unit to the off state when no current is flowing, the signal line is an electric wire, The coil portion can be configured to be inserted in the electric wire in series with the thermal fuse.

[0012] In the stationary charger, the switch circuit includes a thermal relay; The thermal relay is a heat element connected in series to the switch portion of the magnetic switch; The magnetic switch may be configured to include a relay contact connected in series to the coil portion of the magnetic switch. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a stationary charger that can automatically stop charging when the plug terminals are abnormally overheated. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a circuit diagram of a stationary charger according to an embodiment of the present invention. [Figure 2] 1 is an outline view of a stationary charger according to an embodiment of the present invention; [Figure 3] 1A and 1B are diagrams showing a DC plug of a stationary charger according to one embodiment of the present invention, in which (A) is a block diagram and (B) is a diagram showing the structure of the negative electrode side. [Figure 4] 1A and 1B are diagrams showing an example of a metal terminal of the present invention, in which (A) is a front view and (B) is a plan view. [Figure 5] FIG. 10 is a circuit diagram of a stationary charger according to a modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a stationary charger according to the present invention will be described with reference to the accompanying drawings.

[0016] Fig. 1 shows a circuit diagram of a stationary charger 100 according to one embodiment of the present invention, and Fig. 2 shows an outline view of the stationary charger 100. The stationary charger 100 is a charger for a forklift (the "material handling vehicle" of the present invention).

[0017] The stationary charger 100 includes an AC plug 110 , an AC cable 120 , a charger main body 130 , a DC cable 140 , and a DC plug 150 .

[0018] The AC plug 110 is connected to an AC power supply, which may be, for example, a three-phase AC power supply installed in a facility such as a factory or a warehouse.

[0019] The AC cable 120 transmits AC power supplied from an AC power source. One end of the AC cable 120 is connected to the AC plug 110, and the other end is connected to the charger main body 130. The AC cable 120 may be configured as a single power cable, or may be configured as a plurality of connected power cables.

[0020] Charger main body 130 converts AC power supplied via AC cable 120 into DC power and outputs the DC power. Charger main body 130 includes AC input terminals T1 to T3, a switch circuit 131 (magnetic switch 132 and thermal relay 133), a transformer 134, a rectifier circuit 135, and DC output terminals T4 and T5.

[0021] The AC input terminals T1 to T3 are connected to the other end of the AC cable 120. For example, the R phase of AC power is input to the AC input terminal T1, the S phase of AC power is input to the AC input terminal T2, and the T phase of AC power is input to the AC input terminal T3. The AC input terminal T1 is connected to the switch circuit 131 via a current fuse F1, the AC input terminal T2 via a current fuse F2, and the AC input terminal T3 via a current fuse F3. The current fuses F1 to F3 melt when an overcurrent flows. The same applies to the current fuse F4 described below.

[0022] Switch circuit 131 is provided on the primary side of transformer 134, supplies AC power to transformer 134 during charging, and cuts off the supply of AC power to transformer 134 when not charging or when an abnormality occurs. Switch circuit 131 includes a magnet switch 132 and a thermal relay 133.

[0023] The magnet switch 132 includes three switch units 132a that switch between an ON state and an OFF state, and a coil unit 132b. The three switch units 132a are attached to the electric wires connected to the AC input terminals T1 to T3. The coil unit 132b turns the three switch units 132a to the ON state when current is flowing, and turns the three switch units 132a to the OFF state when current is not flowing. When the three switch units 132a are turned to the OFF state, the supply of AC power to the transformer 134 is cut off.

[0024] The thermal relay 133 includes three heat elements 133a and a relay contact 133b. The three heat elements 133a are connected in series with the three switch sections 132a, and the relay contact 133b is connected in series with the coil section 132b. When the heat element 133a detects a predetermined overcurrent, the relay contact 133b is opened, and the supply of current to the coil section 132b is cut off. When the heat element 133a does not detect a predetermined overcurrent, the relay contact 133b is closed.

[0025] The transformer 134 includes a primary coil and a secondary coil (not shown). The primary coil is connected to the switch circuit 131, and the secondary coil is connected to the rectifier circuit 135. The transformer 134 transforms (e.g., steps down) the AC power input to the primary coil and outputs it from the secondary coil.

[0026] The rectifier circuit 135 rectifies AC to DC. The rectifier circuit 135 of this embodiment is a three-phase bridge diode in which six diodes are bridge-connected. A smoothing capacitor may be provided downstream of the three-phase bridge diode. The high-potential side (positive side) output terminal of the rectifier circuit 135 is connected to the DC output terminal T4 via a current fuse F4, and the low-potential side (negative side) output terminal of the rectifier circuit 135 is connected to the DC output terminal T5.

[0027] The control circuit 136 is a controller having pins 1 to 5. The pin 1 is connected to the AC input terminal T2 side of the second switch section 132a. The pin 2 is connected to the DC output terminal T4 via a voltage detection section (not shown). The pin 3 is connected to the DC output terminal T5 via the voltage detection section. The pin 4 is connected to one end side of the coil section 132b (the side opposite to the relay contact 133b) and the AC input terminal T1 side of the first switch section 132a. The pin 5 is connected to the relay contact 133b of the thermal relay 133 via electric wires L1 to L3 (corresponding to the "signal line" of the present invention).

[0028] The control circuit 136 controls the switch circuit 131 while monitoring the voltage between the DC output terminals T4 and T5 from the second and third pins. The voltage between the DC output terminals T4 and T5 corresponds to the voltage of the battery installed in the forklift to which the DC plug 150 is connected. The control circuit 136 passes current through the closed circuit (electric wires L1 to L3) between the fourth and fifth pins, causing current to flow through the coil unit 132b and turning on the switch unit 132a, thereby charging the forklift. When the voltage between the DC output terminals T4 and T5 reaches a predetermined voltage value, the control circuit 136 stops the current flowing through the coil unit 132b, turns off the switch unit 132a, and ends charging of the forklift.

[0029] If an overcurrent flows through the heating element 133a for some reason while the forklift is being charged, the relay contact 133b opens, cutting off the current supply to the coil 132b, turning off the switch 132a, and automatically stopping charging of the forklift.

[0030] The DC cables 140 include a positive DC cable 140a and a negative DC cable 140b, and transmit DC power. One end of the positive DC cable 140a is connected to the DC output terminal T4, and the other end is connected to the plug terminal 151 (positive plug terminal 151a) of the DC plug 150. One end of the negative DC cable 140b is connected to the DC output terminal T5, and the other end is connected to the plug terminal 151 (negative plug terminal 151b) of the DC plug 150.

[0031] The DC plug 150 is configured to be connectable to a power outlet of a forklift. As shown in Fig. 3(A), the DC plug 150 includes a positive plug terminal 151a, a negative plug terminal 151b, and an insulating case 152. The DC plug 150 is further provided with a positive metal terminal 160a and a positive thermal fuse TF1, and a negative metal terminal 160b and a negative thermal fuse TF2.

[0032] One side of the positive plug terminal 151a is connected to the electric wire of the positive DC cable 140a and the positive metal terminal 160a, and the other side is connected to the positive side of the outlet of the forklift. A positive thermal fuse TF1 is disposed in the positive metal terminal 160a.

[0033] One side of the negative plug terminal 151b is connected to the electric wire of the negative DC cable 140b and the negative metal terminal 160b, and the other side is connected to the negative side of the forklift outlet. A negative thermal fuse TF2 is disposed in the negative metal terminal 160b.

[0034] In this embodiment, the positive electrode side plug terminal 151a and the negative electrode side plug terminal 151b have the same configuration, the positive electrode side metal terminal 160a and the negative electrode side metal terminal 160b have the same configuration, and the positive electrode side thermal fuse TF1 and the negative electrode side thermal fuse TF2 have the same configuration.

[0035] The insulating case 152 is a resin case that houses the positive plug terminal 151a and the negative plug terminal 151b. Specifically, the insulating case 152 includes a first housing section and a second housing section, with the positive plug terminal 151a housed in the first housing section and the negative plug terminal 151b housed in the second housing section. The insulating case 152 may also be provided with fixing brackets for fixing the positive DC cable 140a and the negative DC cable 140b.

[0036] 3(B) shows the structure of the negative electrode side of the DC plug 150. Note that the structure of the positive electrode side of the DC plug 150 is the same as the structure of the positive electrode side as described above, and therefore a description thereof will be omitted.

[0037] In this embodiment, the negative side (second housing portion) of the insulating case 152 houses the negative plug terminal 151b, the negative metal terminal 160b, and the negative thermal fuse TF2.

[0038] Negative plug terminal 151b includes crimping portion 153 and connecting portion 154, which are made of a metal with high thermal conductivity (e.g., copper). The electric wire of negative DC cable 140b and negative metal terminal 160b are connected to crimping portion 153. Connecting portion 154 is connected to the negative side of a forklift outlet.

[0039] 4, the negative electrode side metal terminal 160b includes an arrangement portion 161 and a rod portion 162 made of a metal with high thermal conductivity (for example, copper). In this embodiment, a rod-shaped crimp terminal can be used as the negative electrode side metal terminal 160b.

[0040] The arrangement portion 161 is formed in a tubular shape (cylindrical in this embodiment), and the negative electrode thermal fuse TF2 is arranged inside the tube. The negative electrode thermal fuse TF2 is fixed to the arrangement portion 161 with, for example, an insulating adhesive. As shown in FIG. 3(B), the electric wire L3 is drawn out from one side of the tube of the arrangement portion 161, and the electric wire L2 is drawn out from the other side of the tube of the arrangement portion 161.

[0041] The rod portion 162 is formed in a straight line and is inserted into the crimping portion 153 of the negative plug terminal 151b. The rod portion 162 is crimped together with the electric wire of the negative DC cable 140b by the crimping portion 153, while the placement portion 161 is placed in the second housing portion outside the crimping portion 153.

[0042] This prevents the negative thermal fuse TF2 placed in the placement portion 161 from being adversely affected during the crimping process. Furthermore, because the rod portion 162 is inserted into the crimping portion 153, the gap between the crimping portion 153 and the insulating case 152 can be narrow, and the negative thermal fuse TF2 can be provided inside the insulating case 152 without increasing the size of the insulating case 152.

[0043] The negative-side thermal fuse TF2 may be, for example, a non-resettable thermal fuse in which the thermosensitive element contains a fusible alloy. The negative-side thermal fuse TF2 includes a first lead connected to one side of the thermosensitive element and a second lead connected to the other side of the thermosensitive element. The first lead is connected to the electric wire L3 in a state insulated by an insulating tube or the like. Similarly, the second lead is connected to the electric wire L2 in a state insulated by an insulating tube or the like.

[0044] In this embodiment, poor contact between the plug terminal 151 of the DC plug 150 and the outlet of the forklift may cause abnormal overheating at the contact point. For example, poor contact between the positive plug terminal 151a and the positive side of the outlet may cause abnormal overheating at the contact point on the positive side. Also, poor contact between the negative plug terminal 151b and the negative side of the outlet may cause abnormal overheating at the contact point on the negative side.

[0045] For example, if abnormal overheating occurs at the connection portion 154 of the negative plug terminal 151b shown in Figure 3(B), the heat generated at the abnormally overheated area is transferred to the negative thermal fuse TF2 via the crimping portion 153 and the negative metal terminal 160b. Moreover, because the negative thermal fuse TF2 is disposed inside the cylindrical arrangement portion 161, heat is transferred to the negative thermal fuse TF2 from all directions. Therefore, in the event of abnormal overheating, the negative thermal fuse TF2 can be quickly melted (activated).

[0046] 1, if the negative-side thermal fuse TF2 melts (operates) while the forklift is being charged, the supply of current to the coil portion 132b of the magnetic switch 132 is cut off, so the switch portion 132a of the magnetic switch 132 is turned off, and the supply of AC power to the transformer 134 is cut off. In other words, the stationary charger 100 according to this embodiment can automatically stop charging the forklift in the event of abnormal overheating.

[0047] As a result, in the event of abnormal overheating, it is possible to prevent the insulating case 152 from melting or to significantly reduce the amount of melting of the insulating case 152, thereby reliably preventing the area where the negative electrode plug terminal 151b contacts the negative electrode side of the outlet, the spread of fire to the body of the forklift, etc. In other words, the stationary charger 100 according to this embodiment can ensure safety when charging the forklift.

[0048] Furthermore, since the stationary charger 100 according to this embodiment is equipped with the positive electrode thermal fuse TF1, even if abnormal overheating occurs at the positive electrode plug terminal 151a, charging of the forklift can be automatically stopped, just as with the negative electrode plug terminal, thereby ensuring safety during charging of the forklift.

[0049] [Variations] 5 shows a circuit diagram of a stationary charger 100' according to a modified example of the present invention. The stationary charger 100' has the same configuration as the above embodiment, except that it includes a charger main body 130' instead of the charger main body 130.

[0050] The charger main body 130′ has the same configuration as the above embodiment, except that it includes a switch circuit 131′ instead of the switch circuit 131. The switch circuit 131 in the above embodiment includes a magnetic switch 132 and a thermal relay 133, but the switch circuit 131′ in this modification includes the magnetic switch 132 but does not include the thermal relay 133.

[0051] For this reason, the stationary charger 100' according to this modification does not have the overcurrent protection function of the thermal relay 133, but the circuit configuration can be simplified compared to the above embodiment. Furthermore, like the above embodiment, the stationary charger 100' according to this modification can automatically stop charging of the forklift if abnormal overheating occurs at the plug terminal 151, thereby ensuring safety when charging the forklift.

[0052] [Other variations] Although the embodiments and modifications of the stationary charger according to the present invention have been described above, the present invention is not limited to the above-described embodiments and modifications.

[0053] The stationary charger according to the present invention is a stationary charger comprising: an AC plug connected to an AC power source; an AC cable having one end connected to the AC plug and transmitting AC power supplied from the AC power source; a charger main body to which the other end of the AC cable is connected and which converts the AC power supplied via the AC cable into DC power and outputs the DC power; a DC cable having one end connected to the charger main body and transmitting DC power; and a DC plug having a plug terminal having one end connected to the other end of the DC cable and the other end connected to an outlet of a loading vehicle and an insulating case surrounding the plug terminal, and further comprising: a thermal fuse connected to the plug terminal in a manner allowing thermal conduction; and a signal line having a thermal fuse interposed therein and wired from the charger main body to the DC plug and returning to the charger main body, and the configuration of the charger main body can be modified as appropriate as long as it detects activation of the thermal fuse via the signal line and stops the output of DC power.

[0054] For example, in the above embodiment, the positive thermal fuse TF1 is connected to the positive plug terminal 151a via the positive metal terminal 160a, but the positive thermal fuse TF1 may also be connected directly to the positive plug terminal 151a. The positive thermal fuse TF1 can be fixed to the outer peripheral surface of the positive plug terminal 151a by, for example, an insulating adhesive.

[0055] However, in this case, a process of fixing the positive thermal fuse TF1 to the outer peripheral surface of the positive plug terminal 151a is required in addition to the process of crimping the electric wire of the positive DC cable 140a to the positive plug terminal 151a, which reduces workability compared to the above embodiment. Also, if the gap between the crimping portion 153 and the insulating case 152 is narrow and there is not enough space to accommodate the positive thermal fuse TF1, the insulating case 152 needs to be enlarged.

[0056] Similarly, in the above embodiment, the negative thermal fuse TF2 is connected to the negative plug terminal 151b via the negative metal terminal 160b, but the negative thermal fuse TF2 may also be connected directly to the negative plug terminal 151b. The negative thermal fuse TF2 can be fixed to the outer peripheral surface of the negative plug terminal 151b with, for example, an insulating adhesive.

[0057] However, in this case as well, a process of fixing the negative thermal fuse TF2 to the outer peripheral surface of the negative plug terminal 151b is required in addition to the process of crimping the electric wire of the negative DC cable 140b to the negative plug terminal 151b, which reduces workability compared to the above embodiment. Also, if the gap between the crimping portion 153 and the insulating case 152 is narrow and there is no space to accommodate the negative thermal fuse TF2, the insulating case 152 needs to be enlarged.

[0058] The positive electrode side metal terminal 160a has a positioning portion on one side where the positive electrode side thermal fuse TF1 is placed, and a rod portion on the other side which is connected to the positive electrode side plug terminal 151a, so that the shapes of the positioning portion and the rod portion can be changed as appropriate.

[0059] Similarly, the negative electrode side metal terminal 160b has a positioning portion on one side where the negative electrode side temperature fuse TF2 is placed, and a rod portion on the other side which is connected to the negative electrode side plug terminal 151b, so that the shapes of the positioning portion and the rod portion can be changed as appropriate.

[0060] The cargo handling vehicle of the present invention may include any forklift or cargo handling vehicle other than a forklift (for example, a transport vehicle, construction machinery, or agricultural machinery) as long as it is equipped with a battery that can be charged by DC power. [Explanation of symbols]

[0061] 100, 100' Stationary Charger 110 AC plug 120 AC cable 130, 130' Charger body 131, 131' switch circuit 132 Magnetic Switch 132a Switch section 132b Coil section 133 Thermal relay 133a Heat Element 133b Relay contact 134 Trans 135 Rectifier circuit 136 Control circuit 140 DC Cable 140a positive DC cable 140b Negative DC cable 150 DC plug 151 Plug terminal 151a Positive plug terminal 151b Negative plug terminal 152 Insulation Case 153 Crimping section 154 Connection 160a Positive metal terminal 160b Negative metal terminal 161 Placement section 162 Rod section

Claims

1. an AC plug to be connected to an AC power source; an AC cable having one end connected to the AC plug and transmitting AC power supplied from the AC power supply; a charger main body to which the other end of the AC cable is connected, which converts the AC power supplied via the AC cable into DC power and outputs the DC power; a DC cable having one end connected to the charger main body and transmitting the DC power; a DC plug including a plug terminal, one side of which is connected to the other end of the DC cable and the other side of which is connected to a power outlet of a cargo handling vehicle, and an insulating case that houses the plug terminal; A stationary charger comprising: a thermal fuse connected to the plug terminal in a thermally conductive manner; a signal line having the thermal fuse interposed therein and wired from the charger main body to the charger main body via the DC plug, The charger main body includes: Detecting the operation of the thermal fuse via the signal line and stopping the output of the DC power. A stationary charger characterized by:

2. the thermal fuse is connected to the plug terminal via a metal terminal; The metal terminal is The thermal fuse has a mounting portion on one side on which the thermal fuse is mounted, and a rod portion on the other side, the rod portion being connected to the plug terminal.

2. The stationary charger according to claim 1.

3. The arrangement portion of the metal terminal is The thermal fuse is formed in a cylindrical shape, and the thermal fuse is disposed inside the cylindrical shape. The rod portion of the metal terminal is The DC cable is crimped to the plug terminal together with the electric wire.

3. The stationary charger according to claim 2.

4. The plug terminal is It has a positive plug terminal and a negative plug terminal, The thermal fuse is a positive electrode side thermal fuse connected to the positive electrode side plug terminal in a thermally conductive manner; a negative electrode thermal fuse connected to the negative electrode plug terminal in a thermally conductive manner, The positive electrode side thermal fuse and the negative electrode side thermal fuse are It is inserted in series into the signal line.

2. The stationary charger according to claim 1.

5. The charger main body includes: Transformer and a switch circuit that is provided on a primary side of the transformer, and that supplies the AC power to the transformer when in an ON state and cuts off the supply of the AC power to the transformer when in an OFF state; a rectifier circuit provided on the secondary side of the transformer; a control circuit that controls the on state and the off state of the switch circuit, the signal line is connected to the control circuit; The control circuit By turning the switch circuit into the off state, the output of the DC power is stopped.

2. The stationary charger according to claim 1.

6. the switch circuit includes a magnetic switch; The magnetic switch is a switch unit that switches between the on state and the off state; a coil unit that turns the switch unit to the on state when a current is flowing and turns the switch unit to the off state when no current is flowing, the signal line is an electric wire, The coil portion is inserted in the electric wire in series with the thermal fuse.

6. The stationary charger according to claim 5.

7. the switch circuit includes a thermal relay; The thermal relay is a heat element connected in series to the switch portion of the magnetic switch; a relay contact connected in series to the coil portion of the magnetic switch; 7. The stationary charger according to claim 6.

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