JP2002034165A - Safety device for charging battery-operated forklift - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fire when charging by detecting the temperature of a noncontact part such as an outlet, etc., and interrupting power to a charger if the temperature becomes a specified temperature or higher. SOLUTION: Betwen the outlet 11 and the charger 7, the main contact 1a of a magnetic contactor 1 is connected. A thermostat 5 is fitted to a terminal of the outlet 11 directly. If a detected temperature of the thermostat 5 becomes higher than a set temperature, a latching relay 2 is turned on, and its contact 2a closes. Consequently, a relay 3 is excited, and a contact 3b of the relay 3 is turned off, and a contact 3a is turned on. Consequently, the main contact 1a of the magnetic contactor 1 is opened, and power to the charger 7 is interrupted. Simultaneously, the alarm lamp of an alarm device 4 is lighted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery forklift using a battery as a driving source, and more particularly to a charging safety device for charging a battery.

[0002]

2. Description of the Related Art A battery forklift using a battery as a driving source performs loading and unloading work during normal working hours from morning to evening, and charges the battery of the forklift at night when not in use. The forklift is provided with a charging device for charging the battery, and the charging device is supplied from an AC power supply in a power supply premises. An outlet connected to the charging device is provided on the body of the forklift, and by inserting a plug derived from the premises into the outlet, power is supplied to the charging device so that the charging device is charged. Has become.

[0003]

Conventionally, when charging a charging device, the charging is stopped for a fixed time by a timer, or the charging is stopped when the battery is fully charged. However, during charging of the conventional forklift, since the temperature of the contact portion including the plug and the outlet is not detected, the temperature of the contact portion rises due to deterioration or poor contact of the terminal in the plug or the outlet, and fire occurs. There was a danger that. That is, a plug or an outlet is made of a housing plastic, and a metal terminal is provided in the housing, and the plug terminal and the outlet terminal are inserted and connected to energize.

The forklift has a large battery capacity and a large current for charging the battery. Therefore, a large amount of current flows through the plug and outlet terminals. The terminal itself is heated, and this heat is further transmitted to the plastic housing, which ignites.

The present invention has been made in view of the above points, and detects the temperature of a contact portion such as an outlet, and when the temperature reaches a predetermined temperature or more, shuts off the power supply to the charging device and performs charging. It is intended to provide a charging safety device for a battery forklift for the purpose of preventing ignition at a vehicle.

[0006]

According to a first aspect of the present invention, there is provided a charging safety device for a battery forklift, wherein a battery serving as a driving source, a charging device for charging the battery, and a power supply plug are connected. Outlet and
A contactor of a contactor interposed between the outlet and the charging device, a thermostat disposed at the contact portion for detecting a temperature of a contact portion including the outlet and the plug, and a temperature preset by the thermostat. A relay for turning off the contactor so as to turn off the contactor of the contactor when the contactor becomes higher.

[0007] With this configuration, the temperature of the contact portion is detected by the thermostat, and when the temperature exceeds a temperature set in advance by the thermostat, the contactor is turned off and the power supply to the charging device is cut off. In addition, even if the terminals of the contact portion are deteriorated or have poor contact, ignition at the contact portion can be prevented.

According to a second aspect of the present invention, the thermostat is directly attached to a terminal of an outlet.

Thus, the accuracy of the temperature detected at the terminal of the thermostat can be improved.

According to a third aspect of the present invention, there is provided a charging safety device for a battery forklift, wherein when the contactor is turned off, a notification is made to the surroundings by a notification means.

[0011] Thus, it is possible to notify the surrounding workers that the temperature of the contact portion such as the terminal has become higher than the set temperature.

According to a fourth aspect of the present invention, there is provided a charging safety device for a battery forklift, wherein the contactor and the relay are wired discretely to the vehicle body.

As a result, for example, as compared with the case where a temperature sensor such as a thermistor is used, a printed board for mounting each component is not required, and a pattern formed on the printed board itself is not required. The charging safety device can be manufactured inexpensively and easily.

6. The charging safety device for a battery forklift according to claim 5, wherein a metal terminal portion inside the outlet, a through hole penetrating on both sides, and a screw hole communicating with the through hole are provided. A screw for connecting an electric wire inserted through the through hole to the terminal by screwing the screw hole into the screw hole, the thermostat and the mounting hole, and a screw portion screwed into the screw hole of the terminal and the screw. An adapter with a screw hole for screwing is provided, and a screw is screwed into the screw hole of the terminal, and a screw is inserted into the screw hole of the adapter to which the electric wire is connected and the mounting plate and the mounting hole of the thermostat are inserted. The thermostat is attached to the terminal via a mounting plate and an adapter.

[0015] Thereby, the thermostat can be easily attached to the terminal of the outlet via the adapter and the attachment plate, so that the temperature of the terminal itself can be detected.
The accuracy of the detected temperature can be improved.

7. The charging safety device for a battery forklift according to claim 6, further comprising: a metal terminal inside the outlet, a through hole penetrating on both sides, and a screw hole communicating with the through hole. And a screw for connecting an electric wire inserted through the through-hole to the terminal by screwing the screw hole into the screw hole of the terminal and a screw portion provided on the thermostat. A thermostat screw is screwed into the screw hole of the adapter to which the wire is connected by screwing the screw part into the screw hole of the terminal, and the thermostat is attached to the terminal via the adapter. It is characterized by:

Thus, the thermostat can be easily attached to the terminal of the outlet via the adapter, so that the temperature of the terminal itself can be detected and the accuracy of the detected temperature can be improved. In addition, when the thermostat is attached to the terminal, it is only necessary to attach the adapter to the terminal and then attach the thermostat to the adapter, so that the assembly workability can be improved.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a specific circuit diagram of the charging safety device, which is mounted on a body frame side of a forklift without being mounted on each of the illustrated component printed boards. A charging device 7 for charging a battery 8 serving as a driving source is provided, and charging power is supplied to the charging device 7 from a premises power supply via a plug 12 and an outlet 11. A main contact 1a of a magnetic contactor (electromagnetic contactor) 1 is interposed in a main circuit for charging the charging device 7. The plug 12 and the outlet 11 constitute a contact portion.

The magnetic contactor 1 is connected between the power supply side and the ground, and the alarm device 4 and the relay 3 are connected between the power supply of the battery 8 and the ground. Further, a series circuit of the thermostat 5 and the latching relay 2 is connected between the power supply and the ground, and the latching relay 2 is provided with a release switch 6 for releasing the latching state of the latching relay 2. The thermostat 5 is arranged directly on a contact portion such as the plug 12 and the outlet 11, and may be arranged on the surface of the resin at the contact portion.
It is arranged directly to the metal terminal inside.

A normally open (a contact) contact 2a of the latching relay 2 is connected in series with the relay 3, and
The normally open contact 3a of the relay 3 is connected in series with the alarm device 4, and the normally closed (b contact) contact 3b of the relay 3 is connected to the magnetic contactor 1 in series.

FIG. 7 and FIG. 8 show thermostats 5 having different shapes, respectively. The thermostat 5 shown in FIG. 7 is of a type to be mounted via a mounting plate, and is made of a shell metal. And mounting holes 1 on both lower sides
4 are provided. In addition, thermostat 5
The contact 5a shown in FIG.
a Connected to an external electric wire, the connection terminal is omitted in FIG. It is of a type that is directly attached to the thermostat 5 terminal or the like shown in FIG. 8. A mounting screw portion 15 is vertically provided on the lower surface, and a pair of connection terminals 16 for electric wire connection is provided on the upper surface.

The structure of the terminal inside the outlet 11 and the plug 12 and the connection structure of the electric wire to the terminal are shown in FIGS. 9 and 10. Although a plurality of terminals in the outlet 11 are provided, one terminal will be described.
In addition, since the configuration of the entire terminal is a well-known matter, a main part of the terminal will be described in detail.

The metal terminal 30 is formed in a cylindrical shape, and a screw hole 31 having an open upper surface is formed on the upper part of the terminal. A through-hole 32 is formed below the screw hole 31 so as to communicate with the screw hole 31 and penetrate through both sides of the terminal 30.
The conductor 34 of the electric wire 33 is inserted into the through hole 32. Then, the screw 35 is screwed into the screw hole 31 of the terminal 30,
By pressing the conductor 34 against the lower surface of the screw 35, the electric wire 33 is pressed.
Are connected to the terminal 30. A terminal 30 having a screw hole 31 and a through hole 32 and a terminal 3
The terminal portion is constituted by the screw 35 screwed to the terminal 0.

Considering the structure of the terminal 30 as described above,
The configuration shown in FIGS. 3 and 4 is such that the thermostat 5 having the shape shown in FIG. 7 is directly attached to the terminal 30. That is, to attach the thermostat 5 to the terminal 30, an adapter 40 and a mounting plate 44 having a columnar shape or a substantially hexagonal cross section are used, and a screw hole 31 of the terminal 30 is formed from the lower surface of the metal adapter 40. The screw part 41 for screwing to is provided vertically. Further, a screw hole 42 into which the screw 35 is screwed is provided on the upper part of the adapter 40. The metal mounting plate 44 and the lower surface of the thermostat 5 are formed in substantially the same shape, and a screw hole 46 into which a screw 45 is screwed is screwed into one of the mounting plates 44. A hole 47 for inserting a screw 35 is formed in the other side of the mounting plate 44.

Next, the case where the thermostat 5 is attached to the terminal 30 will be described. First, the conductor 34 of the electric wire 33 is inserted into the through hole 32 of the terminal 30, and the screw portion 41 of the adapter 40 is inserted into the screw hole 31 of the terminal 30. The conductor 34 is pressed against the lower surface of the screw portion 41 to connect the electric wire 33 to the terminal 30. Next, the screw 35 having the washer 36 inserted therein is attached to the mounting hole 14 of the thermostat 5 and the mounting plate 44.
The thermostat 5 is attached to the adapter 40 by inserting the screw 35 into the screw hole 42 of the adapter 40 through the hole 47 of the adapter 40. Further, the screw 45 having the washer 36 inserted therein is inserted into the mounting hole 14 of the thermostat 5 and screwed into the screw hole 46 of the mounting plate 44. In this state,
Upper surface of adapter 40 and lower surface of mounting plate 44, mounting plate 44
And the lower surface of the thermostat 5 are in contact with each other, so that heat from the terminal 30 can be efficiently transmitted to the thermostat 5. This allows
It will be attached to the terminal 30 via the thermostat 5 attachment plate 44 and the adapter 40. in this way,
The thermostat 5 can be easily attached to the terminal 30 by screwing the adapter 40 to the terminal 30 and then screwing the screw 35 to the adapter 40.

Next, a thermostat 5 having the shape shown in FIG.
5 and 6 will be described with reference to FIGS. First, as in the case of FIG. 3, the conductor 34 of the electric wire 33 is inserted into the through hole 32 of the terminal 30, and the screw portion 41 of the adapter 40 is screwed into the screw hole 31 of the terminal 30. The conductor 34 is pressed into contact to connect the electric wire 33 to the terminal 30. Next, screw part 1 of thermostat 5
5 is screwed into the screw hole 42 of the adapter 40 and tightened until the lower surface of the thermostat 5 contacts the upper surface of the adapter 40. Thus, the thermostat 5 can be easily arranged on the terminal 30 via the adapter 40.

Next, during charging of the battery 8, if the temperature of the contact portion (the terminal 30 of the outlet 11 in the present embodiment) becomes higher than the set temperature of the thermostat 5, the charging current is cut off, and control is performed until a warning is issued. The operation will be described with reference to the circuit diagram of FIG. 1 and the flowchart of FIG.

First, if the charging timer is on in step S1, the process proceeds to step S2. Here, forklifts are generally charged daily at night after work, for example, so that they are charged at a preset time. Therefore, the above-described charging timer is used, but is not a necessary condition for the present invention. And
In step S2, since the magnetic contactor 1 is turned on and the relay 3 is not excited, the contact 3a of the relay 3 is kept off and the warning lamp of the alarm device 4 is off (off). In this state, charging of the battery 8 is started (see step S3).

Next, proceeding to step S4, it is determined whether or not the temperature is equal to or higher than the preset temperature of the thermostat 5. If the temperature is equal to or lower than the temperature of the thermostat 5, the process proceeds to step S5 to turn off the latching relay 2. Relay 3
Is maintained in the OFF state, and the process returns to step S1 to maintain the charged state. When the thermostat 5 detects the temperature equal to or higher than the set temperature in step S4, the process proceeds to step S6. That is, when the temperature of the thermostat 5 becomes equal to or higher than the set temperature, the contact 5a of the thermostat 5 is turned on to excite the latching relay 2 and turn on the contact 2a of the latching relay 2. When the contact 2a is turned on, the relay 3 is excited, so that the contact 2a of the relay 3 is closed, and at the same time, the contact 2b of the relay 3 is opened. That is,
When the contact 2b of the relay 3 is opened, the power supply to the magnetic contactor 1 is cut off, the main contact 1a is opened, and the power supply to the charging device 7 is cut off. Relay 3 at the same time
When the contact 2a is turned on, the alarm device 4 is energized and the warning lamp is turned on (see step S7) to notify the surrounding workers. Thereby, the charging is stopped as shown in step S8. In addition, as the notification means, in addition to the above-mentioned warning lamp, notification by sound of a buzzer or the like may be used, or notification may be made by both the lamp and the buzzer.

Here, as described above, once the charging is stopped, when the operator presses the release switch 6, the latching relay 2 returns and the charging is started again. Charging cannot be performed until the temperature of the terminal 30 of the outlet 11 becomes lower than the contact temperature (see steps S9 to S4).

As described above, in this embodiment, since the thermostat 5 is directly attached to the terminal 30 of the outlet 11, the accuracy of detecting the temperature of the terminal 30 can be improved. In addition, the charging current can be cut off, and even if the terminal is deteriorated or the contact is poor, ignition of the resin portion of the outlet 11 can be prevented. When a temperature sensor such as a thermistor is used as a sensor for detecting the temperature of the contact portion such as the outlet 11, it is necessary to mount a circuit for signal processing after the temperature sensor on a printed circuit board. However, in the present invention, the components such as the latching relay 2 and the relay 3 are discretely wired by using the thermostat 5 having the contact 5a itself, so that the printed board and the pattern processing required for the printed board are correspondingly performed. It becomes unnecessary, and therefore, the charging safety device can be manufactured simply and inexpensively.

[0032]

According to the charging safety device for a battery forklift according to the first aspect of the present invention, the temperature of the contact portion is detected by the thermostat, and the contactor is turned off when the temperature becomes higher than the temperature preset by the thermostat. As a result, since the power supply to the charging device is shut off, it is possible to prevent ignition at the contact portion beforehand even if there is deterioration or poor contact at the terminal at the contact portion.

According to the charging safety device for a battery forklift according to the second aspect, since the thermostat is directly attached to the terminal side of the outlet, the accuracy of the detected temperature of the terminal in the thermostat can be improved.

According to the third aspect of the present invention, when the contactor is turned off, a notification is made to the surroundings by the notification means, so that a contacting part such as a terminal is set to the surrounding worker by the set temperature. It is possible to inform the fact that it has become the above.

According to the charging safety device for a battery forklift according to the fourth aspect, since the contactor and the relay are wired discretely on the vehicle body side, each component can be compared with a case where a temperature sensor such as a thermistor is used. A printed circuit board for mounting is not required, and a pattern formed on the printed circuit board itself is not required.
The charging safety device can be manufactured inexpensively and easily.

According to the charging safety device for a battery forklift according to the fifth aspect, the thermostat can be easily attached to the terminal of the outlet via the adapter and the mounting plate, so that the temperature of the terminal itself can be detected, and the detected temperature can be detected. Accuracy can be improved.

According to the charging safety device for a battery forklift according to the sixth aspect, the thermostat can be easily attached to the terminal of the outlet via the adapter, so that the temperature of the terminal itself can be detected and the accuracy of the detected temperature can be reduced. Can be improved. In addition, when the thermostat is attached to the terminal, it is only necessary to attach the adapter to the terminal and then attach the thermostat to the adapter, so that the assembly workability can be improved.

[Brief description of the drawings]

FIG. 1 is a specific circuit diagram of a charging safety device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a control operation when charging according to the embodiment of the present invention.

FIG. 3 is an exploded view when the thermostat of the embodiment of the present invention is attached to a terminal via an adapter.

FIG. 4 is a front view of the thermostat according to the embodiment of the present invention in a state where terminals are attached via an adapter.

FIG. 5 is an exploded view when a thermostat of another shape according to the embodiment of the present invention is attached to a terminal via an adapter.

FIG. 6 is a front view of a thermostat of another shape according to the embodiment of the present invention in a state where terminals are attached via an adapter.

7A and 7B are a plan view and a front view of a thermostat according to an embodiment of the present invention.

8A and 8B are a plan view and a front view of a thermostat having another shape according to the embodiment of the present invention.

FIG. 9 is an exploded perspective view when connecting the terminal of the outlet and the electric wire according to the embodiment of the present invention.

FIG. 10 is a front view when the terminal of the outlet and the electric wire according to the embodiment of the present invention are connected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic contactor 2 Latching relay 3 Relay 4 Alarm device 5 Thermostat 6 Release switch 7 Charging device 8 Battery 11 Outlet 12 Plug 14 Mounting hole 15 Screw part 30 Terminal 31 Screw hole 32 Through hole 33 Electric wire 34 Conductor 35 Screw 40 Adapter 41 Screw part 42 screw hole

Claims (6)

[Claims] 1. A battery as a driving source, a charging device for charging the battery, an outlet to which a power supply plug is connected, and contact points of a contactor interposed between the outlet and the charging device A thermostat disposed at the contact portion for detecting the temperature of the contact portion formed of the outlet and the plug; and turning off the contactor to turn off the contactor of the contactor when the temperature becomes higher than a preset temperature by the thermostat. A charging safety device for a battery forklift, comprising a relay for controlling the charging. 2. The charging safety device for a battery forklift according to claim 1, wherein the thermostat is directly attached to a terminal of an outlet. 3. The charging safety device for a battery forklift according to claim 1, wherein a notification unit notifies the surroundings when the contactor is turned off. 4. A discrete wiring is provided on the contactor and relay body side.
A charging safety device for a battery forklift according to any one of the above. 5. A metal terminal inside the outlet,
A terminal provided with a through hole penetrating on both sides and a screw hole communicating with the through hole, and a screw connecting the electric wire inserted into the through hole to the terminal by screwing into the screw hole of the terminal; A thermostat, a mounting hole, an adapter having a screw portion screwed into the screw hole of the terminal and a screw hole into which the screw is screwed is provided, and the screw portion is screwed into the screw hole of the terminal. 5. The thermostat according to claim 1, wherein a screw passing through the mounting plate and the mounting hole of the thermostat is screwed into a screw hole of the adapter to which the electric wire is connected, and the thermostat is mounted on the terminal via the mounting plate and the adapter. A charging safety device for a battery forklift according to any one of the above. 6. A metal terminal inside the outlet, a through hole penetrating on both sides, and a screw hole communicating with the through hole are provided, and a screw portion screwed into the screw hole of the terminal and a thermostat are provided. An adapter with a screw hole into which the screw part is screwed is provided.The screw part of the thermostat is screwed into the screw hole of the adapter to which the screw part is screwed into the terminal screw hole and the electric wire is connected. The charging safety device for a battery forklift according to any one of claims 1 to 4, wherein the thermostat is attached to the terminal via an adapter.