JPS61221097A - Safety circuit in battery type industrial car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a safety circuit for preventing abnormal start of an industrial vehicle such as a forklift.

(Prior Art) Generally, some battery-powered industrial vehicles such as forklifts are equipped with a device such as a dead man seat for detecting whether a driver is present in the driver's seat. This parking seat is structured so that when the driver gets out of the driver's seat, the seat flips up and the parking brake is applied, and when the driver gets back into the driver's seat, the parking brake is released.

(Problems to be Solved by the Invention) By the way, in the conventional industrial vehicle as described above, when the key switch is turned on, the vehicle can be started by the driver sitting in the driver's seat. There was a problem that if you forgot to turn the key switch on and accidentally stepped on the accelerator, the vehicle would suddenly start moving.

(Means for solving the problem) Therefore, in view of the above problems, the present invention requires that when the driver gets out of the driver's seat and sits back in the driver's seat, the key switch must be turned OFF once and then turned ON again. This is characterized by a structure that prevents the vehicle from starting to move.

(Example) Embodiments of the present invention will be specifically described below with reference to the drawings.

First, prior to explaining the embodiments, a description of the conventional technology will be added. In FIG.
4.

On the other hand, the current flowing through the armature coil 14 is returned to the battery 1 via the field coil 14a and the chopper 15.

Note that the armature coil 14 is provided with a wheeling diode 13 and an armature diode 16, respectively.

Next, the rotation of the armature coil 14 is controlled by the forward direction switch 7 and the backward direction switch 1.
It is controlled by 0. That is, when the forward direction switch 7 is pressed,
The forward contactor 8 is excited and the switching contact 8ab is switched, and the field coil 14a is switched to the armature coil 1.
4 is excited in the direction of forward rotation. Furthermore, when the reverse direction switch 10 is pressed, the reverse contactor 11 is energized, the switching contact 11ab is switched, and the field coil 14a is energized in the direction of reversing the armature coil 14.

On the other hand, between the battery 1 and the direction switch 7 and 10, there are fuses for the t and +11 circuits, 2 and the key switch 3, respectively. Therefore, in this conventional example, when the key switch 3, the exhaust man seat switch 5, and the accelerator switch 9 are all turned on, the forward The traveling motor 18 can be rotated in a direction determined by the operating state of the direction switch 7 or the reverse direction switch 10.

The above-mentioned passenger seat switch 5 is a switch that is operated in conjunction with the driver's seat, and the accelerator switch 9 is a switch that is operated in response to depression of an accelerator (not shown). When the accelerator switch 9 is depressed, a signal is sent to the chopper 15 by a circuit (not shown), thereby changing the conductivity of the chopper 15 and changing the rotational speed of the motor.

Next, a first embodiment of the present invention will be described based on FIG. This first embodiment is different from the conventional circuit described above.
．． Second auxiliary relays 4 and 6 are provided. And this first one. By providing the second auxiliary relays 4 and 6, the running motor 18 is prevented from starting unless the dead man seat switch 5 is turned on before the key switch 3 is turned on.

First, the second auxiliary relay 4 is connected to the control circuit fuse 2 via the key switch 3.

Next, the first auxiliary relay 6 is connected to the control circuit fuse 2 through a parallel circuit of the dead man seat switch 5, a normally open contact 6al, and a normally closed contact 4b.

On the other hand, the circuit consisting of the forward direction switch 7 and the two-way contactor 8 and the circuit consisting of the reverse direction switch 10 and the reverse contactor 11 are as follows:
Accelerator switch 9 and normally open contacts 6a2, 4a, respectively
It is connected to the control circuit fuse 2 via.

Subsequently, the operation and effect of the first embodiment configured as described above will be explained.

First, when the driver sits in the driver's seat, the passenger seat switch 5 is turned on. For this reason, battery 1. Control circuit fuse 2. A circuit consisting of the normally closed contact 4b and the dead man seat switch 5 is connected to the first auxiliary relay 6.
is excited. When the first auxiliary relay 6 is excited, the normally open contact 6a1 is turned on, so the first auxiliary relay 6 is self-held.

Next, when the key switch 3 is turned on, the second auxiliary relay 4 is energized, and its normally open contact 4a is turned on and its normally closed contact 4b is turned off. Note that even in this state, the first auxiliary relay 6 is still self-supported.

Next, turn on either the forward direction switch 7 or the reverse direction switch 10.
When the driver presses the accelerator (not shown), either the forward contactor 8 or the reverse contactor 11 is energized.

Here, it is assumed that the song selection direction switch 7 is ON.
When the forward contactor 8 is energized, the switching contact 8ab is switched and the travel motor 18 begins to rotate forward. Then, when the accelerator pedal (not shown) is further depressed, the current from the battery 1 is transferred to the travel motor fuse.

-Z12. Amateur coil 14. switching contact 11ab,
It flows through the field coil 14a, the switching contact 8ab, and the chopper 15, and the rotational speed of the travel motor 18 is controlled in proportion to the conductivity of the chopper 15.

Next, when the driver leaves the cab with the key switch 3 and forward direction switch 7 turned on,
The det man seat switch 5 is turned OFF. Then,
The self-holding of the first auxiliary relay 6 is released and the normally open contact 6
a1.6a2 turns OFF.

Next, when the driver sits in the driver's seat again, the passenger seat switch 5 is turned on, but since both the normally open contact 6a1 and the normally closed contact 4b are turned off, the first auxiliary relay 6 is not energized. . Therefore, if the accelerator is depressed and the accelerator switch 9 is turned ON, the normally open contact 6a2 will remain OFF.
The vehicle never starts moving.

Therefore, in order to start the traveling motor 18, the driver turns off the key switch 3 once.

Then, the normally closed contact 4b turns ON and the first auxiliary relay 6
is excited and self-held by the normally open contact 6a1, so the normally open contact 6a2 is turned on and the travel motor 18 can be started. That is, by stepping on an accelerator (not shown), the armature coil 14 rotates and the vehicle can move forward or backward until t.

As described above, in this first example, once the driver gets out of the driver's seat, even if the driver gets back into the driver's seat, the vehicle will continue to operate unless the key switch 3 is turned OFF and then turned ON again. It never starts to move. For this reason, even if the driver gets out of the driver's seat with key switch 3 on, then sits back in the driver's seat and forgets that key switch 3 is on and accidentally presses the accelerator, the vehicle will not start moving. It becomes safe.

On the other hand, when the user wants to move the vehicle, he or she simply has to turn off the key switch 3 and then turn it on again, making it extremely easy to move the vehicle.

Next, a second embodiment will be explained based on FIG. 2. This second embodiment shows an embodiment in which the traveling motor 18 cannot be started if the direction switch 7 or 10 is turned on before the dead man seat switch 5 is turned on.

Therefore, in this embodiment, a neutral position detection switch 17 for detecting that the forward direction switch 7 and the reverse direction switch 10 are in the neutral position is provided in place of the key switch 3 in the first embodiment. Furthermore, the key switch 3 is arranged in series with the normally open contact 4a.

Next, the operation and effects of this second embodiment will be explained. When the driver sits in the driver's seat, the passenger seat switch 5 is turned on. Therefore, a circuit consisting of the normally closed contact 4b and the dead man seat switch 5 is formed, and the first
The auxiliary relay 6 is energized and its normally open contact 6a1 is turned on.
Then, the first auxiliary relay 6 is self-held.

Next, if you turn on the key switch 3 and then turn on either the forward direction switch 7 or the reverse direction switch 10 (here, for example, assume that the forward and reverse direction switch 7 is turned on), this @ When the road direction switch 7 is turned on, the neutral position detection switch 17 is first turned on.
, and the second auxiliary relay 4 is energized. For this reason,
The normally closed contact 4b is turned off and the normally open contact 4a is turned on.

Next, when the driver depresses the accelerator (not shown) of the vehicle, the accelerator switch 9 is turned on. For this reason, key switch 3.
Since the normally open contact 4a, the normally open contact 6a2, the accelerator switch 9, and the forward direction switch 7 are all turned on, the forward contactor 8 is energized and its switching contact 8 is turned on.
AB is 1 moss broken.

Furthermore, when the accelerator pedal (not shown) is depressed, the current supplied from the battery 1 is transferred to the travel motor fuse 12. Amateur coil 14. It passes through switching contact 11ab, switching contact 8ab, and chopper 15, and the rotational speed of armature coil 14 is controlled in proportion to the conductivity of chopper 15.

Next, if the driver leaves the driver's seat with the key switch 3 turned on and either the two-way direction switch 7 or the reverse direction switch 10 left turned on, the driver seat switch 5 is turned OFF, the self-holding of the first auxiliary relay 6 is released, and the normally open contacts 6a1 and 6a2 are turned OFF.
Become FF.

Next, when the driver sits in the driver's seat again, the passenger seat switch 5 is turned on, but since both the normally closed contact 4b and the normally open contact 6a1 are turned off, the first auxiliary relay 6 is energized. It will not be done. For this reason, the normally open contact 6
Since a2 remains in the OFF state, the traveling motor 18 will not start even if the accelerator switch 9 is depressed.

Next, in order to start the traveling motor 18, the direction switch 7.10 is once returned to the neutral position. Then, the neutral position detection switch 17 is turned OFF and the excitation of the second auxiliary relay 4 is canceled, so the normally closed contact 4b is turned ON, the first auxiliary relay 6 is energized, and the normally open contact 6a1 is activated. Retained.

Therefore, the normally open contact 6a2 is also turned ON, so when the accelerator switch 9 is depressed, the key switch 3° normally open contact 4a
, normally open contact 6a2. A current flows through the accelerator switch 9 and the forward direction switch 7, and the two-way contactor 8 is energized, making it possible to start the travel motor 18.

In this way, in the second embodiment, when the driver leaves the driver's seat and sits in the driver's seat again, the direction switch 7.10 is returned to the neutral position, and then the direction switch 7.10 is moved to the forward or reverse side again. This prevents the travel motor 18 from being activated inadvertently unless the direction switch 7.10 is turned on.

Therefore, in this second embodiment, even if you forget that the key switch 3 and forward direction switch 7 (or reverse direction switch 10) are turned on and press the accelerator, the vehicle will not start moving unexpectedly. It's safe.

Subsequently, a third embodiment will be described based on FIG. 3. In this third embodiment, if either the key switch 3 or the direction switch 7.10 is turned on before the seat switch 5, the driving motor 18 cannot be started. This is an example.

Therefore, in this third embodiment, the key switch 3 in the second embodiment shown in FIG. 2 described above is connected in parallel with the neutral position detection switch 17.

Next, the operation and effects of this third embodiment will be explained. First, when the driver sits in the driver's seat, the passenger seat switch 5 is turned on. Therefore, the circuit consisting of the normally closed contact 4b and the dead man seat switch 5
The auxiliary relay 6 is energized. Also, since the normally open contact 6al is turned on, the first auxiliary relay 6 is connected to the normally open contact 6a1.
It is self-maintained by a circuit consisting of a detonator seat switch 5 and a det man seat switch 5.

Next, when the key switch 3 is turned on, the second auxiliary relay 4 is energized, its normally open contact 4a is turned on, and its normally closed contact 4b is turned off.

Next, the forward direction switch 7 or the reverse direction switch 10 is turned on.

(In this embodiment, the forward direction switch 7 is set to OFF.
It shall be set to N. ) Then, when the forward direction switch 7 is turned on, the neutral position detection switch 17 is also turned on.

Next, when the driver depresses the accelerator (not shown), the accelerator switch 9 is turned on. For this reason, the normally open contacts 4a, 6a2. A circuit consisting of the accelerator switch 9 and the forward direction switch 7 is formed, the two-way contactor 8 is energized, and the switching contact 8ab is switched. Then, when you step on the accelerator further, battery 1. Travel motor fuse 12
．． Amateur coil 14. A circuit consisting of switching contact 11ab, switching contact 8ab, and chopper 15 controls the rotational speed of travel motor 18 in proportion to the conductivity of chopper 15.

On the other hand, key switch 3 or direction switch 7
．． If the driver leaves the driver's seat with 10 turned on,
Since the dead man seat switch 5 is turned off, the excitation of the first auxiliary relay 6 is released. Therefore, both the normally open contact 6a1 and the normally open contact 6a2 are turned OFF.

Next, when the driver sits in the driver's seat again, the exhaust man seat switch 5 is turned ON, but since the second auxiliary relay 4 is energized, the normally closed contact 4b is OFF, so the first Auxiliary relay 6 is not energized. Therefore, the normally open contact 6a2 remains in the OFF state, so the traveling motor 18 cannot be started.

In order to start the driving motor 18 from this state, turn off the key switch 3 and return the direction switch 7.10 to the neutral position (that is, by returning the direction switch 7.10 to the neutral position, the neutral position detection switch 17
is turned off).

Then, the second auxiliary relay 4 is de-energized and the normally closed contact 4b is turned on, so the first auxiliary relay 6 is energized and the normally open contact 6a2 is turned on, making it possible to start the traveling motor 18. becomes.

In this way, in this third embodiment, if either the key switch 3 or the direction switch is turned on before the seat switch 5, the driving motor 1 is turned on.
8 cannot be started. Further, in order to start this, the key switch 3 is turned OFF, the direction switch is returned to the neutral position, and then the direction switch is placed in the forward or reverse direction again.

Although the deadman seat switch is used as the deadman switch in the first to third embodiments, any means for detecting whether or not there is a driver in the driver's seat may be used.

(Effects of the Invention) As explained above, in the present invention, with the configuration described in the claims, when the driver leaves the driver's seat with the key switch turned on and gets back into the driver's seat, the driver can turn the key switch on. It has the excellent feature of being extremely safe, as even if you forget that it is on and step on the accelerator carelessly, the vehicle will not suddenly start moving.

In addition, to move the vehicle again, turn the key switch off once.
Since it only needs to be set to FF, it also has the desirable feature that it can be started in the FF mode.

[Brief explanation of the drawing]

1 to 3 of the drawings show embodiments of the present invention,
FIG. 1 is a circuit diagram showing a first embodiment of the invention, FIG. 2 is a circuit diagram showing a second embodiment of the invention, and FIG. 3 is a circuit diagram showing a third embodiment of the invention.
A circuit diagram showing an embodiment, and FIG. 4 is a circuit diagram showing a conventional example. 1... Battery 2... Control circuit fuse 3... Key switch 4... Second auxiliary relay 4a... Normally open contact 4b... Normally closed contact 5... Dead man seat switch 6... First auxiliary relay 6a1... Normally open contact 6a2... Normal contact 7... Direction switch for forward movement 8... Contactor for forward movement 8ab... Switching contact 9... Accelerator switch 10...Reverse direction switch 11...Reverse contactor 11ab...Switching contact 12...Travel motor fuse 13...Wheeling diode 14...Amateur coil 14a...Field Coil 15... Chopper 16... Amateur diode 17... Neutral position detection switch 18... Traveling motor

Claims (1)

[Claims] A safety circuit for a battery-powered industrial vehicle of the type that has a battery and uses current from the battery to drive a running motor to drive the vehicle, which memorizes that a deadman switch has been turned OFF, and OFF
When the first auxiliary relay is in a state where it remembers that the deadman switch has been turned off, the first auxiliary relay cuts off the power supply to the traveling motor; and when the first auxiliary relay is in a state where it remembers that the deadman switch has been turned off, and a second auxiliary relay that releases the memorized state of the first auxiliary relay by once turning off a key switch.