JPH01178057A - Brake controller for reach forklift - Google Patents

Abstract

PURPOSE:To permit the sure electric brake application by detecting the getting- on/off of a driver to a prescribed position of a reach forklift and switching-ON /OFF the feed of electricity to a control means for speed-controlling a driving motor for traveling according to the getting-on/off state. CONSTITUTION:A driver takes a seat of a reach forklift and steps-on a rubber switch 31 in mat form which is laid on the floor part of the forklift and constitutes a driver detecting means 3, and then the resistance value of the rubber switch 31 is varied. Then, the binary signal on the basis of the lowering of voltage of the rubber switch 31 is outputted from an amplification circuit 32, and the contact point 33 of a brake relay is closed. If the driver steps-on a brake releasing pedal in this state, the brake power of a disc brake is released, and traveling is started by the power of a driving motor M. Further, when an accelerating lever is operated, the output electric current of a transistor 13 is controlled according to an acceleration signal Sa supplied from a rotary encoder 18, and the number of revolution of the driving motor M is varied.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a braking control device for an electric reach forklift that can be used.

[Prior art] A conventional reach forklift brake control device °C1
a mechanical brake device that releases braking by pressing a brake release pedal; a control means that applies electrical braking to a rotating drive motor by operating a direxicon lever;
llllrn by depressing/releasing the brake release pedal
Some have been known to have a brake switch that cuts off and on the power supply to the means.

In this device, when the brake release pedal is not depressed, the mechanical brake device mechanically brakes the traveling drive device, and the brake switch drives the traveling drive device via the control means. The power supply to the 11Jv motor is cut off, and as a result, the movement of the forklift is doubly restricted. When the brake release pedal is depressed, the mechanical brake device mechanically releases the braking of the driving drive fJ+ device, the brake switch supplies power to the control means, and the υll1I1 means drives [
-The rotation of the motor can be controlled. In this state, when the dilexicon lever is turned in the opposite direction while the reach forklift is running, the drive motor consumes running energy as a start, and the reach forklift is electrically braked. This electric braking is often used in actual driving because it provides a braking force that corresponds to the traveling speed.

Conventionally, the brake switch is generally a limit switch, which is attached to a brake release pedal or a link mechanism operated by the brake release pedal, and supplies power to the control means in conjunction with the depression/release operation of the brake release pedal. It has an intermittent pull function.

[Problems to be Solved by the Invention] However, as can be seen from the operational relationship between the depressed position of the brake release pedal, the brake switch, and the mechanical brake means shown in FIG. Depending on the degree to which the brake release pedal is depressed, the brake switch may not operate even though the mechanical brake means has been released, and as a result, power may not be supplied to the control means. That is, in FIG. 5, the -dotted chain point LO represents the natural position of the brake release pedal when the brake release pedal is not depressed, and L1 represents the natural position of the brake release pedal when the brake release pedal is depressed and release of mechanical braking is started. L2 is the depressing position where the mechanical brake is completely released.
13 indicates the depression position where power supply to the control means starts,
L4 represents the maximum depression position. Therefore, machine 1. LJ! 11 The difference x 3 between the complete release range x 1 and the electric braking possible range x 2 is the range in which both electric braking and mechanical braking do not operate. Therefore, when the brake release pedal is depressed within this range x 3, the electric braking is not possible even if the direction lever is turned in the opposite direction while driving, and the mechanical braking will of course not operate, so unexpected brakes may occur. The situation could occur in the tribe. In addition, if the brake release pedal is depressed in the range x 4 where mechanical braking is partially released, electric braking cannot be used at the same time even if the direction lever is moved in the opposite direction, which may result in insufficient braking. There was sex.

The above-mentioned non-braking range x 3 may further expand if the positional relationship between the brake release pedal or link mechanism and the brake switch changes over time due to vibration or wear, and the non-braking range x 3 may expand further if the positional relationship between the brake release pedal or link mechanism and the brake switch changes over time due to vibration or wear. Reliability was in question.

The present invention has been devised in view of the above-mentioned problems, and includes brake systems for reach forklifts that can reliably perform electric braking despite changes in the amount of depression of the brake release pedal and the position of the brake switch over time. 'The purpose is to provide an IE device.

[Means for Solving the Problems] The present invention detects when a driver gets on and off a reach forklift at a predetermined position, and when the driver gets on and off a reach forklift, the above-mentioned 1IIl 11
A technical measure is taken to independently provide a driver occupancy detection means that cuts off and on the power supply to one means.

[Operation] In the reach forklift shift control device of the present invention, the mechanical brake means releases the mechanical braking of the traveling drive device by pressing the brake release pedal. The driver boarding detection means detects the boarding of the driver at a predetermined position of the reach forklift, and starts supplying power to the control unit upon boarding the reach forklift. The control means can start, stop, and control the speed of the drive motor of the traveling drive device immediately after the start of the power supply, and furthermore, it is possible to perform 11 electric movements by operating the direction lever in the opposite direction while the vehicle is traveling. becomes.

That is, in the present invention, when the driver's boarding is detected by the first stage of driver boarding detection, the control means is replaced to a state where it can control the drive motor regardless of the operation of the brake release pedal.

[Example] Specific examples of the present invention will be described based on FIGS. 1 to 4. Figure 1 shows the lI of the reach 1-crit of this example.
, is a schematic diagram of the IJ IIJ m device, and FIG.
FIG. 2 is an electrical block diagram of the brake control device shown in FIG.

FIG. 3 is a side view of a reach forklift truck equipped with a brake control device according to this embodiment, and FIG. 4 is a plan view thereof.

As shown in FIGS. 1 and 2, the brake control device for this reach forklift includes a control means 1 for electrically braking a drive motor M of a traveling drive device (not shown) at a speed of 1III all, and a brake release pedal. a mechanical brake means 2 which mechanically operates the travel drive device (not shown) by 171 vJ by actuation of a brake release pedal 21; It consists of means 3.

The traveling drive device (not shown) includes a drive motor M installed in a drive unit room located on the side of the driver's seat.
and a reduction gear that transmits the rotation of the drive motor M to the wheels 6. The drive motor M is a DC series motor.

The control means 1 controls the start/stop of the drive motor M and the speed If.
vJ all, a travel control circuit 11 that commands electric braking, and a driver transistor 13 that is controlled by the travel control circuit 11. Furthermore, as shown in FIGS. 2, 3, and 4, the control means 1 includes a direction lever 15 for switching the electrically biasing direction of the drive motor M, a position sensor 16 for detecting the position of the direction lever 15, It has an accelerator lever 17 for controlling the traveling speed r1 and a rotary encoder 18 that detects the position of the accelerator lever 17. The running series control circuit 11 is configured to start and stop the front 2, speed a 1.
II III is a microcomputer device that commands control operations such as electric braking, and has a field coil switching relay (not shown). As shown in FIG. 2, the field coil switching relay (not shown) has an output J contact 14 for switching the connection direction of the field coil f of the drive motor M.

The position sensor 16 detects the forward movement of the direction lever 15,
This is a sensor that detects the reverse and neutral positions.
The rotary encoder 18 is a sensor that detects the position of the accelerator lever 17.

The emitter of the driver transistor 13 is grounded, its base is connected to the traveling tII11&11 circuit 11, and its collector is connected to the output contact 14, the field coil f1 drive motor M (particularly the armature coil A), and the positive terminal of the valve 37 via the fucose 39. connected to the side.

As shown in FIG. 1, the mechanical brake means 2 includes a brake release pedal 21, a disc brake 22 that is directly connected to the rotating shaft of the drive motor M of the travel drive 5A and reduces the mechanical biasing force thereof, and a brake release pedal 21. It consists of a link mechanism 25 that transmits the angle of change of the pedal 21 to the disc brake 22. The brake release pedal 21 is installed near the floor 30 of the driver's seat as shown in FIGS. 3 and 4, and when it is not depressed, it is moved to the position LO (the first (Fig.) is maintained. Although the internal structure of the disc brake 22 is not shown, a cam 26 rotatably supported at one end 28 is connected to a disc pad (not shown) inside the disc brake 22.
The frictional state between the disc wheel and the disc wheel (not shown) is adjusted. The link mechanism 25
Rad portions 25A, 125B, 25C, 25D, and 25E operate in this order to transmit the angle change of the brake release pedal 21 to the cam 26, and the cam 26 resists the mechanical biasing force of the spring 27 to release the disc brake 22. I'ltl! It is configured to control braking force.

The driver boarding detection means 3 is a mat-shaped rubber switch 31 placed on the floor 30 of the driver's seat of the reach forklift.
and an amplification circuit section 32 that amplifies and binarizes the output current of the rubber switch 31 and operates a built-in brake relay (not shown). The rubber switch 31 is a variable elastic resistance body having surface electrodes (not shown) provided on both sides of carbon-containing rubber III (not shown), and furthermore, the surfaces of the surface electrodes are covered with a resin layer (not shown). Protected by insulation.

The output contact 33 of the built-in brake relay (not shown) of the amplifier circuit section 32 is connected in series with the power supply terminal of the travel control circuit 11, as shown in FIG.

The operation of the till control device for this reach forklift will be explained below.

When a driver gets on the driver's seat of the reach forklift and steps on a pine i-shaped rubber switch 31 laid on the floor 30 of the driver's seat, the resistance of the rubber switch 31 changes. The amplifier circuit section 32 detects the voltage drop of the rubber switch 31, and binarizes the detected voltage drop using a built-in comparator (not shown).
Then, the brake relay (
(not shown). The output contact 33 of the brake relay (not shown) applies the voltage of the battery 37 to the cruise control circuit 11 via the fuse 38, and as a result, the cruise control circuit 11 is connected to the driver transistor 13 and the contact 14.
i, II m becomes possible.

Here, it is assumed that the dilexicon lever 15, which switches between the forward operation and the approach/retreat operation of the reach forklift, is in the forward position, and accordingly, the travel control circuit 11 has the contact 14 in the 8th position.

When the driver depresses the brake release pedal 21, the angle of change of the brake release pedal 21 is transmitted to the cam 26 via the link mechanism 25, as shown by the arrow in FIG. The frictional braking force of the disc brake 22 is partially or completely released against the mechanical biasing force of the spring 27.

As a result of (a), the rotating shaft of the drive motor M connected to the rotating shaft 29 of the disc brake 22 becomes rotatable.

When the driver operates the accelerator lever 17, the rotary encoder 18 outputs the accelerator signal 3a to the travel control circuit 11 in accordance with the angle change of the accelerator lever 17, and the
[, the control circuit 11 controls the output current of the drive transistor 13 according to the accelerator signal 3a. The rotational speed of the drive motor M is then controlled according to the output current of the drive transistor.

When the driver releases the brake release pedal 21, mechanical braking by the disc brake 22 is applied again. Also, if the driver turns the direction lever in the opposite direction while the reach forklift is running, that is, if the driver puts the direction lever 16 in the backward position while moving forward or puts the direction lever 16 in the forward position while moving backward, the direction lever The travel control circuit 11 that receives the direction lever position signal Sd from the position detection device 16 has a contact point 1.
4 to position A or position B. As a result, the direction of the field current flowing through the field coil f is reversed, the electrical biasing force of the drive motor M is reversed, and electrical braking occurs.

Naturally, the machine 1 described above. You are free to choose between the lj-kun and the electric v1-kun, and it is also possible to use both together.

According to this embodiment, there is an advantage that electric braking can be reliably achieved in accordance with the traveling speed, and furthermore, it is possible to apply mechanical braking of a necessary magnitude while applying electric braking. Further, in a running state where the brake release pedal 21 is depressed to release mechanical braking, if the direction lever 15 is turned on, a reliable electric illumination can be obtained without becoming a free running state.

In this embodiment, it is of course possible to replace the rubber switch 31 in the shape of the pin 1, which is the driver occupancy detection means 3, with another mechanical switch, an optical limit switch, or the like.

[Effects of the Invention] As explained above, the reach forklift braking control device of the present invention can electrically brake the drive motor to reduce the speed. I1 means and a driver occupancy detection means that detects when the driver gets on or off the reach forklift at a predetermined position and continues to supply power to the control means when the driver gets on or off the reach forklift, regardless of whether the brake release pedal is depressed. You can reliably apply electric v1 shift to a reach forklift.

Furthermore, according to the present invention, when using the mechanical half-braking state, power supply to the drive motor can be ensured without fail, so the repetition of mechanical half-braking and driving by the drive motor, and the instantaneous braking operation can be reliably performed. There are advantages that can be achieved.

[Brief explanation of the drawing]

Figure 1 shows the braking system of the reach forklift truck according to this embodiment.
FIG. 2 is an electrical block diagram of the brake control device shown in FIG. 1. FIG. FIG. 3 is a side view of a reach forklift equipped with the υ1 shift 1ift device according to this embodiment, and FIG. 4 is a plan view thereof. FIG. 5 is a diagram showing the operational relationship between a brake release pedal, a brake switch, and a mechanical brake means of a conventional reach forklift. 1... Control means 2... Mechanical play, Means 3... Driver occupancy detection means Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] (1) A reach forklift equipped with a control means for electrically braking the speed of a drive motor of a traveling drive device, and a mechanical brake device for mechanically braking the traveling drive device by actuation of a brake release pedal. A reach forklift, characterized in that the braking control device is independently provided with a driver occupancy detection means that detects whether the driver gets on or off the reach forklift at a predetermined position and cuts off power supply to the control means when the driver gets on or off the reach forklift. brake control device.