JPH0523218B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a pedal lock device for an industrial vehicle.

More specifically, the present invention relates to an electrical circuit configuration of an electromagnetic cargo handling pedal lock device, such as a so-called skid steer loader, in which left and right wheels are driven independently for running and steering.

[Conventional technology]

In a skid steer loader, it is extremely dangerous if the driver does not sit properly in the driver's seat or operates the cargo handling equipment in an abnormal posture, and is likely to cause a serious accident.

For this reason, the skid steer loader automatically locks the cargo handling pedal when operation is stopped, and when operation resumes the next time, it is automatically detected that the driver is seated in the seat and fastened the seat belt. When the conditions for turning on the key switch are met, the electromagnetic pedal lock device is released.

The current electromagnetic cargo handling pedal lock device has a circuit configuration as shown in FIGS. 2 and 3.

In other words, the key switch 3 of the skid steer loader, the seat switch 1 that is activated by the load when the driver is seated, and the seat belt switch 2 that is activated when the driver fastens (connects) his or her seat belt.
and a solenoid 4 for unlocking the cargo handling pedal 7.
are connected in series. Therefore, seat switch 1, seat belt switch 2, key switch 3
When all the switches are turned on, the unlocking solenoid 4 of the cargo handling pedal 7 is energized, the stopper 5 of the cargo handling pedal 7 swings around the pin 6, the stopper 5 is disengaged from the cargo handling pedal 7, and the cargo handling pedal is released. 7
operation becomes possible.

[Problem that the invention seeks to solve]

The conventional cargo handling pedal lock release device circuit has a problem in that the lock device is released as long as the seat belt is tied even if the driver is not wearing the seat belt.

In other words, if the seatbelt is tied at the end while it is long, the locking device will come off even if it is placed on the top of the seat, behind the seat, or under the driver's buttocks. There is a problem that cargo handling operations become possible.

It is extremely dangerous to operate a skid steer loader in such a state, and the inventors of the present invention have made extensive studies to solve the above-mentioned problems.

As a result, in the conventional cargo pedal lock release circuit, it is difficult to detect whether the driver is seated in the seat or not.
It has been found that there is a problem in that if the conditions of fastening the seat belt and turning on the key switch are satisfied, the cargo handling pedal is released regardless of the order in which the switches are activated.

[Means for solving problems]

The present invention has been made based on the above-mentioned knowledge, and a seat switch that is activated when a load is applied to the seat is connected in series to a first relay, and a seat belt switch that is activated when the seat belt is connected is connected to the first relay. a normally closed contact of the second relay is provided in series with the seat switch and the first relay; a normally closed contact is provided in the first relay in series with the second relay;
A key switch for operating an industrial vehicle, a normally open contact of the first relay, and a solenoid for releasing the cargo handling lock device are in series with the seat belt switch and in parallel with the normally closed contacts of the second relay and the first relay. The foregoing problem is solved by an industrial vehicle load-handling pedal lock device circuit characterized in that it is provided.

[Effect]

In the present invention, the cargo handling pedal lock device is released only when the seat belt switch is activated after the seat switch is activated.
The cargo handling pedal lock device is released if the driver fastens the seat belt after sitting in the seat, but the cargo handling pedal lock device is released if the driver sits in the seat with the seat belt still tied. Unable to carry out cargo handling work. Therefore, accidents caused by driving without wearing a seat belt can be prevented.

〔Example〕

FIG. 1 shows a circuit diagram of a pedal lock device circuit according to the present invention. An electromagnetic relay R1 is connected in series to a seat switch 1 that is activated when a driver sits on a seat 8.

In addition, an electromagnetic relay R2 is connected in series to the seatbelt switch 2, which is activated by tying the seatbelt.
is connected.

Furthermore, in series with the seat belt switch 2,
A key switch 3 for operating the skid steer loader and a solenoid 4 for releasing the cargo handling lock device are provided in parallel with the electromagnetic relay R2.

The armature of the solenoid 4 is connected to a stopper 5 that can swing around a pin 6, as shown in FIG. ), or the load-handling pedal 7 is released (unlocking the load-handling pedal).

The normally closed contact (B terminal) R1b of the electromagnetic relay R1 is connected in series with the relay R2, and the normally open contact (A terminal) R1a is connected to the key switch 3 and the solenoid 4.
are installed in series. Furthermore, electromagnetic relay R2
A normally closed contact (B terminal) R2b is provided in series with relay R1.

With the above configuration, under normal conditions,
It works as follows.

Initially, seat switch 1, seat belt switch 2, and key switch 3 are all off, and electromagnetic relays R1 and R2 are in a non-energized state.

When the driver takes a seat in the seat 8, the seat switch 1 is turned on, and the B terminal R2b of the electromagnetic relay R2,
The electromagnetic relay R1 is energized through the seat switch 1 and excited. As a result, A of electromagnetic relay R1
Terminal R1a is turned on and B terminal R1b is turned off.

Next, when the driver seated in the seat 8 fastens his or her seat belt, the seat belt switch 2 is turned on. However, the electromagnetic relay R2 is not energized because the B terminal R1b of the electromagnetic relay R1 is off.

Furthermore, when the driver turns on the key switch 3, the solenoid 4 is energized through the seat belt switch 2, the A terminal R1a of the electromagnetic relay R1, and the key switch 3, and the cargo handling pedal is unlocked.

When the driver ties the seat belt and sets it on the seat 8 or on the rear side of the seat 8 before sitting on the seat 8, the seat switch 1 and the key switch 3 are turned off and the seat belt 2 is turned on.

In this state, seat switch 1 is off, and electromagnetic relay R1 is off. Therefore, the B terminal R1b of the electromagnetic relay R1 is on, and the seat belt switch 2 is on, so the electromagnetic relay R2 is energized and excited, and the electromagnetic relay R2 is turned on.
The B terminal R2b of No. 2 is off.

Even if the driver sits on the seat to operate the cargo handling system in this state, electromagnetic relay R2
Since the terminal R2b is off, even if the seat switch 1 is turned on, the electromagnetic relay 1 is not energized. Therefore, the A terminal R1a of the electromagnetic relay R1 remains off, the B terminal R1b remains on, and the electromagnetic relay 2 continues to be energized.

Even if the driver turns on the key switch 3, since the A terminal R1a of the electromagnetic relay R1 is off, the solenoid 4 is not energized and the cargo handling pedal 7 is not unlocked.

As mentioned above, by using this circuit configuration,
After the driver is seated in the seat 8, the cargo handling pedal 7 will not be unlocked unless the driver fastens the seat belt on his or her waist or shoulder (in the case of a three-point seat belt).

When the driver gets out of the vehicle, he turns off either the seat switch 1, the seatbelt switch 2, or the key switch 3, and the power to the solenoid 4 is cut off.
The cargo handling pedal 7 is locked.

〔Effect of the invention〕

According to the present invention, the cargo handling pedal cannot be unlocked unless the driver fastens the seat belt after sitting in the seat, so the driver can be reliably fastened with the seat belt, and cargo handling work can be carried out safely. can be done.

In the present invention, solenoids for releasing the seat switch, seatbelt switch, key switch, and cargo handling lock device are connected to a relay under specific circuit conditions, and the structure is simple and the operation is reliable.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG.
FIG. 3 is a conventional circuit diagram. 1... Seat switch, 2... Seat belt switch, 3... Key switch, 4... Solenoid.

Claims (1)

[Claims] 1. A seat switch 1 that is activated when a load is applied to the seat 8 is connected in series to the first relay R1, and a seat belt switch 2 that is activated when the seat belt is connected is arranged in parallel with the seat switch 1. The second relay R2 is connected in series to the seat switch 1 and the first relay R1.
A normally closed contact R2b of the first relay R1 is provided in series with the seat belt switch 2 and the second relay R2.
A normally open contact R1a of the relay R1 and a solenoid for releasing the cargo handling lock device are provided in series with the seat belt switch 2 and in parallel with the normally closed contacts R1b of the second relay R2 and the first relay R1. A cargo handling pedal lock device circuit for an industrial vehicle, characterized in that: