JPH0733011A - Driving wheel load relesing device for unmanned vehicle - Google Patents

Abstract

PURPOSE:To provide a simplified engineering means which releases traveling load generated by rotating the wheels forcibly with frictional force from a floor surface when an unmanned vehicle is used by hand-pushing operation, for example. CONSTITUTION:In an unmanned vehicle, in which a driving carriage 7 provided with driving wheels 6 and driven wheels 5 is provided on the frame 4 of the vehicle, is installed at a position between the driving wheels 6 and the driven wheels 5 so that the carriage can make a relative oscillating motion around a shaft parallel to the shaft of the driven wheels 5, an up/down lever 20 which is either integral with an operating lever 21 or is so linked with the lever to make an oscillating motion is provided on the driving carriage 7 in its extension on the opposite side of the driving wheels from the driven wheel 5. A roller 23 is journaled to the top of the up/down lever 20 so that the roller may be brought into push-contact with the lower surface of the frame 4 when the up/ down lever 20 is raised. A stopper 24 is also provided so that the further oscillating motion of the up/down lever 20 may be regulated at a position which is slightly beyond a position where the up/down lever 20 stands perpendicularly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for releasing a traveling load generated when a drive wheel is forcibly rotated by a frictional force from a floor surface when an automatic guided vehicle is used, for example, by a manual pushing operation. It is about.

[0002]

2. Description of the Related Art An automated guided vehicle is usually constructed so as to run along a colored strip or a metal tape provided on the floor or a signal line embedded in the floor. Usually, in order to simplify the drive system, the frame of an automatic guided vehicle is supported by four driven wheels including two caster wheels, and one steering and driving wheel is provided in the substantially central portion of the frame. It is normal. The steering and drive wheels steer the transport vehicle by rotating the wheels around the axle and applying a driving force to the transport vehicle, and turning the axle around a vertical axis.

[0003]

When it is attempted to move the automatic guided vehicle to a position deviating from its travel route, the driving force is cut off to move it by hand or the steering system is switched to a manual steering system. It is necessary to move by manual steering. However, in the former method, since the drive wheels are generally driven from a drive source such as a motor through a speed reducer, when the transport vehicle is moved by hand, the drive wheels are forcibly forced by the frictional force from the floor surface. There is a problem that a very large force is required to move the carrier because the speed reducer acts as a speed increaser by being rotated and a large mechanical friction load is applied to the drive wheels. Further, the latter method requires two steering systems, an automatic steering system and a manual steering system, and thus has a problem that the control device becomes expensive.

The present invention has been made to solve the above problems, and provides a simple technical means for reducing the running resistance of an automated guided vehicle when the driving force of the automated guided vehicle is turned off and the automated guided vehicle is moved by pushing or the like. The challenge is to get it.

[0005]

In a drive wheel load releasing apparatus for an automatic guided vehicle according to the present invention, a drive carriage 7 provided with a drive wheel 6 and a driven wheel 5 on a frame 4 of the vehicle is a drive wheel 6 and a driven wheel. In an automatic guided vehicle that is relatively swingable about an axis parallel to the axis of the driven wheel 5 at a position between the driven wheel 5 and the driven wheel 5, the operation lever 21 is provided on the extension portion of the driven vehicle 5 on the side opposite to the driven wheel. A raising / lowering lever 20 is provided integrally with or swingably connected with the raising / lowering lever 20, and a roller 23 that is pressed against the lower surface of the frame 4 when the raising / lowering lever 20 stands up is axially attached to the tip of the raising / lowering lever 20. In addition, a stopper 24 is provided for restricting further swinging of the raising / lowering lever 20 at a position where the raising / lowering lever 20 slightly exceeds the vertical standing position.

[0006]

The load of the frame 4 of the automatic guided vehicle and the load 27 loaded on the frame 4 is partially fixed at a constant rate.
Acts on the carriage 7 and is further distributed to the driven wheels 5 and the drive wheels 6 at a constant rate and loaded. Therefore, when the vehicle is traveling, a load is applied to the drive wheels 6 substantially in proportion to the weight of the load, and the load prevents slip between the drive wheels and the floor surface, thus realizing stable traveling of the carrier vehicle.

When the automatic guided vehicle is moved by pushing by hand or the like, the operating lever 21 is operated to swing the raising / lowering lever 20 in the standing direction until it comes into contact with the stopper 24. When the raising / lowering lever 20 stands up, the roller 23 comes into contact with the lower surface of the frame 4 and pushes up the frame 4, but in reality, the carriage 7
The side is pushed down, and the dolly 7 swings about the connecting portion 8 as a fulcrum in the direction of raising the drive wheel 6 side. This swinging motion causes the drive wheels 6 to move away from the floor surface 28. This frame 4
The relative tilted state of the carriage 7 is held by its own weight because the load of the frame 4 applied to the roller 23 tends to rotate the raising / lowering lever 20 in the direction of pressing it against the stopper 24. Therefore, if the automatic guided vehicle is pushed in this state, the drive wheel 6 is not in contact with the floor surface, the load acting from the drive wheel becomes 0, and the automatic guided vehicle can be moved with a light force. In particular, in the structure of the present invention, since the drive wheels are completely separated from the floor surface, the drive wheels are kept steered, that is, the drive wheels are stopped while forming an angle with respect to the traveling direction of the transport vehicle. Even in such a case, the steered wheels do not interfere with the traveling of the bogie or give a traveling load at all.

[0008]

EXAMPLE An example shown in the drawings will be described below. In the illustrated embodiment, the fixed wheel is removed from the frame 4 of the handcart 3 having the two caster wheels 1 and the two fixed wheels, and the dolly 7 having the driven wheels 5 and the drive wheels 6 is inserted into the frame 4. It shows a configuration used as an automated guided vehicle. The handcart 3 and the bogie 7 are pivotally attached to each other at a connecting portion 8 thereof by a fulcrum pin 9 in a direction parallel to an axis of a driven wheel 5 of the bogie. The dolly 7 has a flat T-shape, and the driven wheels 5 are individually rotatably attached to both ends of the bar (T-shaped horizontal bar) so that the axles thereof are on the same axis line. The drive wheel 6 is attached to the front end portion of FIG. The drive wheel 6 is axially supported by a shaft box 12 which is pivotally supported by a carriage 7 by a vertical turning pin 11, and a motor 13 for driving the drive wheel 6 in a traveling direction is mounted on the shaft box 12 and a speed reducer 14 The drive wheels 6 are driven via. Meanwhile, dolly 7
A slewing gear 15 having the center of the slewing pin 11 as an axis is fixed to the slewing gear, and this slewing gear and a gear 17 fixed to an output shaft of a steering motor 16 mounted on a shaft box 12 are connected by a chain. .

The bogie 7 extends beyond the shaft-mounted position of the driven wheel 5 to the side opposite to the driving wheel, and the extended portion thereof raises and lowers a pin 20 in a direction parallel to the axis 18 of the driven wheel. Is pivoted. The raising / lowering lever 20 has an integrated operation lever 21.
A pedal 22 is attached to the tip of the. On the other hand, a roller 23 that freely rotates around an axis parallel to the pin 19 is provided at the tip of the raising / lowering lever 20, and a stopper 24 is fixedly provided on the carriage 7 side. The stopper 24 is provided so as to come into contact with the raising / lowering lever 20 at a position where the raising / lowering lever 20 has swung further to the opposite side from the vertical direction and prevent further swinging.
In the device in which the carriage 7 and the operation lever 21 are arranged as described above, the pedal 22 at the tip of the operation lever 21 is located below the handle 25 of the handcart.

About half of the load of the load 27 placed on the frame 4 of the handcart is loaded on the caster wheel 1 of the handcart, and the other half of the load is on the connecting portion 8. The truck 7 is partially loaded. The load acting on the connecting portion 8 is distributed to the drive wheel 6 and the driven wheel 5 according to the ratio of the distance L ₁ from the connecting portion to the driving wheel and the distance L ₂ from the connecting portion to the driven wheel. To be done. Therefore, the driven wheel 5
By determining the ratio of L ₁ to L ₂ between the drive wheel 6 and the driven wheel 5 so that the load ratio applied to the drive wheel 6 becomes the optimum ratio, the handwheel can be efficiently driven without slipping on the drive wheel 6. 3 (unmanned guided vehicle) can be driven. The detection device of the traveling road and the control device of the steering motor 16 based on the detection device may be the same as those of the conventional device, and thus the drawings and the description thereof are omitted.

When the apparatus having the above structure is used by a manual pushing operation, the drive source is turned off to stop the drive wheels and the pedal 22 is depressed. Then, the raising / lowering lever 20 stands up and swings until it abuts on the stopper 24, so that the carriage 7 is swung clockwise in the drawing to lift the drive wheels 6 from the floor surface 28. Since this state is held by the load or the weight of the handcart as described above, pushing the handle 25 of the handcart in this state allows the handcart 3 to be conveyed to a free position off the traveling path. it can.

[0012]

According to the present invention described above, since the running resistance acting from the drive wheels at the time of manual pushing movement can be reduced to zero by the extremely simple structure, it is extremely easy to switch between automatic running and manual running. It is possible to obtain an unmanned guided vehicle that can be used, for example, to obtain a suitable unmanned guided vehicle by a semi-automatic semi-manual transportation line when the transportation vehicle must be finely moved at each station of a long transportation path to perform complicated work. it can.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment.

[Fig. 2] Bottom view of the drive cart

FIG. 3 is a perspective view of a driving wheel driving and steering mechanism as seen from below.

[Explanation of symbols]

 4 frame 5 driven wheel 6 drive wheel 7 dolly 20 raising / lowering lever 21 operation lever 23 roller 24 stopper

Claims (1)

[Claims] 1. A drive carriage (7) in which a drive wheel (6) and a driven wheel (5) are provided on a frame (4) of a carrier vehicle is located at a position between the drive wheel (6) and the driven wheel (5). In an unmanned guided vehicle that is relatively swingable around an axis parallel to the driven wheel (5), an operating lever (21) is provided on the extension of the driven wheel (7) from the driven wheel (5) on the side opposite to the driven wheel. ) Is provided integrally with or swingably connected to the bottom of the frame (4) when the raising / lowering lever (20) stands up. The roller (23) to be contacted is pivotally attached, and the stopper (24) that restricts the further rocking of the raising / lowering lever (20) at a position where this raising / lowering lever (20) slightly exceeds the vertical standing position. )
A drive wheel load releasing device for an automated guided vehicle, characterized in that: