JPH0151388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive device for a traveling trolley for transporting cargo used in a multi-level automated warehouse, and more particularly to a device for hydraulically driving the traveling of the trolley.

The traveling trolley used for the above purpose is equipped with a cargo support platform that can be raised and lowered to receive cargo placed on pallets, etc., and travels on rails, and after arriving at a predetermined location, lowers the support platform and places the cargo on a shelf. The robot then leaves the location and moves to transport another load, which is repeated. In this case, conventional running of the trolley and lifting and lowering of the cargo support platform are all driven by mechanical means using electric power.

An example of a conventional mechanical drive device will be described with reference to the attached FIGS.
The chain sprockets e and f attached to the shaft of are driven by the chain sprocket h attached to the reducer g. The reducer g is driven by a chain sprocket k attached to a motor i with a brake and a chain sprocket l attached to the input side of the reducer g. The traveling trolley a is equipped with a load support stand m, and the load is supported via rotating rollers p attached to the load support stand m by rotating eccentric cams n attached to hollow shafts c and d surrounding the axes of the drive wheels. The platform m is lifted up to a high level y shown by the imaginary line, travels in that state, and after arriving at a predetermined position, the cargo support platform m is lowered and the cargo is transferred to a shelf (not shown), and then the cargo support platform m
Leave the location while descending and drive toward the next destination. To drive the eccentric cam n, a chain sprocket s attached to a geared motor r rotates chain sprockets t and u attached to hollow shafts c and d, thereby rotating the eccentric cam n by a predetermined amount. A take-up chain sprocket u is provided on the running chain sprockets e, t, and h to prevent the chain from loosening. Also, the lifting chain sprocket s, t,
A take-up chain sprocket q is similarly provided at u to prevent the chain from loosening. Further, the traveling truck a is provided with a control panel w.

As mentioned above, the speed reduction mechanism of conventional trolleys has a constant reduction ratio, so the moving speed of the trolley depends solely on the acceleration/deceleration characteristics of the electric motor, and the acceleration during acceleration/deceleration is roughly adjusted. When used for transporting products that are easy to move or collapse, the impact may be applied to the loaded products or items due to the effect of inertia acting on the loaded products or items when speeding up, decelerating, or stopping, resulting in damage or damage to the items. There are drawbacks such as causing cargo to collapse. Further, since the traveling operation and the lifting operation are each driven by independently provided electric motors via a reduction gear, the traveling truck becomes large. Furthermore, since the minimum speed of the traveling bogie is determined by the reduction ratio of the reducer, it is difficult to obtain a sufficiently low speed with a small reducer, and there remains a problem that requires improvement in terms of accuracy in the stopping position of the bogie. has been done.

The present invention has been made for the purpose of eliminating the various drawbacks mentioned above, and a driving device for a traveling trolley according to the present invention is a traveling trolley that can move forward and backward and has a luggage support platform that can be raised and lowered. It is equipped with a hydraulic cylinder for raising and lowering, a hydraulic motor for driving the traveling trolley, and a hydraulic source for driving the hydraulic cylinder and the hydraulic motor, and a control switching valve for controlling starting/stopping and forward/backward movement of the hydraulic motor. A flow regulating valve is provided in the pressure oil supply line of the motor and also controls the acceleration when increasing the speed of the hydraulic motor and the reverse acceleration when decelerating the hydraulic motor, and is provided in the oil drain line of the hydraulic motor so that the opening/closing speed of the valve can be controlled. Furthermore, the present invention is characterized in that the flow rate passing through the flow rate adjustment valve can be adjusted in order to enable the desired low-speed travel when the traveling bogie is stopped.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the driving device for a traveling trolley according to the present invention will be described below with reference to the accompanying drawings.

A first embodiment is shown in FIGS. 4 to 7. The traveling truck 1 has four driving wheels 2 and four driven wheels 3, and travels by driving the driving wheels 2 by a chain sprocket 6 attached to a hydraulic motor 5 via a chain sprocket 4. Further, the traveling trolley 1 is equipped with a cargo support stand 7, which is attached to the bottom surface of the traveling trolley 1 through pins 8 horizontally, or approximately horizontally with an inclination so as not to protrude above the height i of the trolley.
The hydraulic cylinder 9 is expanded and contracted, and the rollers 12 and 13 are moved up and down using the pin 11 attached to the hollow shaft 10 that covers the shaft on which the drive wheel is attached as a pivot. The telescopic movement of the hydraulic cylinder 9 is transmitted to the connected hollow shaft 17 as the vertical movement of rollers 18 and 19. That is, a total of four rollers 12, 13, 18, two on each shaft, attached to two hollow shafts 10, 17,
19 lifts the load support stand 7, travels with the load 42 lifted on a high level, and after reaching a predetermined position descends to a lower level, places the load 42 on the upper surface of the rail that also serves as a shelf, and releases it.

The hydraulic system includes a single hydraulic power source 23 constituted by a hydraulic pump 22 driven by one electric motor 20 via a coupling 21, and the hydraulic power source 2.
3, a hydraulic motor 5 rotatable in both forward and reverse directions drives the traveling cart 1 by receiving pressurized oil from the hydraulic cylinder 9, a hydraulic cylinder 9 that raises and lowers the cargo support platform 7, and various control valves, that is, the motor 5. A control switching valve 24 for controlling start/stop and forward/reverse rotation direction, and the motor 5
A first flow regulating valve 2 consisting of a flow regulating valve 25 and a control piston 26 that control acceleration (rate of increase in speed) and reverse acceleration (rate of decrease in speed) during increase/deceleration of the
7. An increase/decrease switching valve 28 that controls the opening/closing speed of the first flow rate regulating valve, an elevation switching valve 29 that controls the expansion and contraction of the hydraulic cylinder 9, and a hydraulic system according to the hydraulic system diagram shown in FIG. Contact each of the above equipment,
It is composed of a piping device including a pressure oil supply line 30, an oil drain line 31, a hydraulic tank 32, a relief valve 33, and the like.

Next, to explain the operation of the traveling bogie 1, in order to start and accelerate the stopped bogie in the forward direction (arrow A), first, the solenoid installed in the control switching valve 24 is
Sol.2, then the solenoid of the increase/decelerate switching valve 28.
When Sol. 1 is energized, the motor 5 starts to rotate normally, and then the control piston 26 moves in the direction of arrow D, and the opening degree of the first regulating valve 27, specifically the valve 25, increases to increase the oil pressure. The rotational speed of the motor 5 increases,
The traveling trolley 1 starts, is accelerated, and then starts running at a constant speed. For deceleration during forward (motor forward rotation) constant speed running, when the solenoid Sol. However, the rotational speed of the hydraulic motor 5 decreases, and the traveling trolley 1 begins to decelerate.

Acceleration and reverse acceleration are adjusted using the acceleration/deceleration switching valve 28.
When the moving speed of the piston 26 is changed by changing the opening degree of the second flow rate regulating valve 34 incorporated in the first flow rate regulating valve 27, this is achieved by changing the valve opening/closing speed of the first flow rate regulating valve 27. That is, when reducing the magnitude of acceleration, the second
When the flow rate of the flow rate adjustment valve 34 is decreased, the control piston 2, which is moving at a certain speed at that time,
Since the moving speed of the piston 6 is reduced, the opening/closing speed of the valve 25 of the first flow rate regulating valve 27 is reduced, and the acceleration of the hydraulic motor 5 is weakened.

To stop the traveling bogie 1 that is moving forward (motor rotation forward), once the solenoid Sol. is cut off, the hydraulic motor 5 stops, and therefore the traveling carriage 1 also stops.

The accuracy of the stop position is adjusted by the first flow rate adjustment valve 27.
This is achieved by limiting the flow rate of the valve 25 to a small flow rate.

Next, to explain the operation of moving the stopped truck 1 backward (in the direction of arrow B), in order to start the stopped motor 5, first, the solenoid Sol.
Then, the solenoid Sol.1 of the acceleration/deceleration switching valve 28
When energized, pressure oil is supplied in the direction of reversing the hydraulic motor 5, while the piston 26 moves in the direction of arrow D, opens the valve 25 of the first flow rate regulating valve 27, and the traveling truck 1 starts in the reverse direction. The vehicle is accelerated and then starts running at a constant speed. In order to decelerate during constant speed running in reverse (motor reversal), when the solenoid Sol. The opening degree decreases, and the traveling trolley 1 begins to decelerate. To stop the traveling truck, first decelerate and then release the excitation of the solenoid Sol. 3 of the control switching valve 24, the hydraulic motor 5 will stop, and therefore the traveling truck 1 will also stop.

As an emergency measure, if you want to move the traveling trolley 1 by input during a power outage, etc., please use the stop valve 35.
By fully opening the hydraulic motor 5, the hydraulic motor 5 is released and the traveling trolley 1 can move both forward and backward. Further, the pressure oil supply line 30 is equipped with a relief valve 33,
Prevent overload of related equipment due to excessive hydraulic pressure.

Finally, to explain the operation when lifting and lowering the cargo support platform 7, by energizing the solenoid Sol. Also, by energizing the solenoid Sol. 5 of the elevation switching valve 29, the axis of the cylinder 9 is contracted in the direction of arrow T, and the cargo support platform 7 is lowered.

The traveling trolley 1 is provided with a traveling control limit switch and a lifting control limit switch (not shown), and a control panel 36 for performing the above-mentioned electrical control. Power is supplied to the traveling vehicle 1 through a power supply cable (not shown) attached to the lower surface of the control panel 36.

In addition, to prevent the load support platform 7 from swinging back and forth and left and right during lifting and lowering operations, rollers 12, 13, and 1 are used.
Flanges (shoulders) 41 are provided at 8 and 19 to suppress left and right deflection, and a drop-in stopper 37 is provided to prevent longitudinal movement.

Next, a second embodiment is shown in FIGS. 8 to 11. This embodiment relates to a drive device for lifting and lowering a traveling trolley having a load support platform for transporting relatively heavy loads (approximately 2 to 3 tons) or long objects. The device part includes a sprocket for driving each driven wheel 3.
This embodiment is the same as the first embodiment except that a chain 38 is provided on the axle of each driving wheel and each driven wheel. Identical parts in the figures are designated by the same reference numerals.

Only the lifting device will be explained below.

The load support platform 7 is supported by four hydraulic cylinders 9, 9', 9'', and 9 arranged vertically at the four corners of the traveling trolley 1, and the four hydraulic cylinders are expanded and contracted by hydraulic pressure to move it up and down. By doing this, the load support platform 7 is lifted to the position C when ascending, and lowered to the position C when descending. The distance ring z between the top surface of 7 and the top surface of the rail that also serves as a shelf is approximately equal,
The total distance should be approximately 40mm. In order to reduce the horizontal load applied to the four hydraulic cylinders 9, 9', 9'', and 9 when the traveling speed of the traveling truck changes or when the load support platform is raised and lowered, a One or more drop-in stoppers 37
will be established. A hole 40 may be formed in the load support base 7 so that the fitted state of the stopper 37 can be easily checked visually. As shown in Fig. 11, the hydraulic system diagram shows that four hydraulic cylinders 9, 9', 9'', and 9 are connected instead of the one hydraulic cylinder in the first embodiment; This is the same as in the embodiment. To explain the operation when the cargo support platform 7 is raised and lowered, each axis of the hydraulic cylinders 9, 9', 9'', and 9 is activated by energizing the solenoid Sol. starts to extend in the direction of the arrow, lifts the cargo support platform 7, and energizes the solenoid Sol. The load support platform 7 is lowered in the direction shown in FIG.

Note that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

Since the traveling bogie drive device of the present invention has the above-described configuration, it can achieve the following remarkable effects.

(i) By installing a reduction gear for traveling and driving it with a traveling motor, and using a geared motor for lifting and lowering, the conventional traveling trolley is made hydraulic, making it easier to adjust the speed and reduce acceleration and reverse acceleration. Since the size of the container can be freely controlled, products that are easily damaged or items that are likely to collapse can be safely transported. Furthermore, since low-speed operation is possible, the accuracy of the stop position of the traveling carriage can be improved.

(ii) For the reasons stated in the previous section, it becomes possible to run and move up and down with a single electric motor, making the trolley more compact.

(iii) In times of emergency, power outage, etc., moving the traveling trolley by hand can be easily done by fully opening the stop valve.

(iv) Lifting and lowering of the cargo support platform is performed by hydraulic cylinders, and by appropriately selecting the number and arrangement of hydraulic cylinders according to the weight and shape of the cargo, it is easy to create a cargo support platform with the width and length that suits the cargo. can be designed. Furthermore, the height i of the traveling cart can be made thinner, and the height of the cargo 42 can be increased.

(v) By installing a relief valve in the pressure supply line, there is no risk of excessive load being applied to the drive unit or load support, and the safety of the equipment is guaranteed.

[Brief explanation of drawings]

Fig. 1 is a plan view of a conventional traveling trolley, Fig. 2 is a cutaway side view of the lifting/lowering operation portion of the load support platform viewed from the - direction in Fig. 1, and Fig. 3 is a traveling operation from the - direction in Fig. 1. FIG. 4 is a plan view of a driving device for a traveling bogie showing the first embodiment of the present invention, and FIG.
FIG. 6 is a cutaway front view showing the structure of the axle in the direction shown in FIG. 4, FIG. 6 is a cutaway side view of the drive device of the load support platform seen from the − direction in FIG. 4, and FIG. 7 is a hydraulic system diagram of the drive device in FIG. 4. FIG. 8 is a plan view of a driving device for a traveling truck showing a second embodiment of the present invention; FIG.
The figure is a cutaway side view taken from the − direction in FIG. 8, FIG. 10 is a cutaway front view of the drive device of the cargo support platform taken from the − direction in FIG. 8, and FIG. 11 is the hydraulic system of the drive device in FIG. 8. Figure. In the figure, 1 is a traveling trolley, 5 is a hydraulic motor, 7 is a load support platform, 9, 9', 9'', 9 are hydraulic cylinders, 2
3 is a hydraulic power source, 24 is a control switching valve, 27 is a first flow rate adjustment valve, 29 is a lift switching valve, 30 is a pressure oil supply line, 31 is an oil drain line, and 34 is a second flow rate adjustment valve. be.

Claims (1)

[Scope of Claims] 1. A traveling truck that can move forward and backward and has a load support platform that can be raised and lowered, comprising: a hydraulic cylinder that raises and lowers the load support platform; a hydraulic motor that drives the travel truck; In addition to being equipped with a hydraulic source for driving the motor, a control switching valve for controlling starting/stopping and forward/backward movement of the hydraulic motor is installed in the pressure oil supply line of the hydraulic motor, and also controls the acceleration during speed increase and deceleration of the hydraulic motor. A flow rate regulating valve for controlling reverse acceleration is provided in the oil drain line of the hydraulic motor so that the opening/closing speed of the valve can be controlled, and the flow rate regulating valve is configured to control the opening/closing speed of the valve. A driving device for a traveling bogie, characterized in that the flow rate passing through can be adjusted. 2. The driving device for a traveling bogie according to claim 1, wherein the valve opening/closing speed of the flow rate regulating valve is configured to be controllable by adjusting the valve opening degree of another flow rate regulating valve. 3. Claim 1 or 2, characterized in that one hydraulic cylinder is installed substantially horizontally on the bottom surface of the cargo support platform, and the cargo support platform is raised and lowered via a link mechanism. A drive device for the traveling trolley described. 4 At the four corners of the bottom of the cargo support stand, place four squares perpendicular to the bottom.
3. The drive device for a traveling trolley according to claim 1 or 2, characterized in that said hydraulic cylinder is attached to raise and lower said load support platform.