JP3240802B2 - Order picker lifting speed adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting speed adjusting device used for a lift cylinder of an order picker.

[0002]

2. Description of the Related Art The configuration shown in FIG. 6 is employed as an order picker generally used conventionally.

[0006] In FIG. 6, reference numeral 1 denotes an order picker used for speedily processing a dispensing operation in a warehouse. The order picker 1 is provided with a front wheel 2 which is both a driving wheel and a steering wheel, and a rear wheel 3 which rotates freely, and a mast 5 which is raised and lowered by two lift cylinders 4 in the center. Is erected. On an inner mast (not shown) of the mast 5, a platform 6 configured so that a worker can work while standing is slidably mounted via a chain (not shown). I have. The platform 6 is provided with an operation panel 7 as shown in FIG. 7, and the operation panel 7 has various devices necessary for operating the order picker 1. For example, the operation panel 7
A handle 8 for steering the front wheel 2 in an arbitrary direction is provided on the front surface, and a loading / unloading operation section 9 for raising / lowering the platform 6 and moving the order picker 1 forward and backward is provided on the side surface. .

As shown in FIG. 8, a lifting push button switch 10 for supplying hydraulic oil to the lift cylinder 4 to raise the platform 6 is provided to the cargo handling operation section 9.
A lowering push button switch 11 for allowing hydraulic oil to flow out of the lift cylinder 4 to lower the platform 6, a horn switch 12 for generating an alarm sound, and moving the order picker 1 back and forth in its rotating direction. An accelerator lever 13 that can change the traveling speed according to the amount of rotation is provided.

The platform 6 is provided with a head guard 14, a deadman brake 15, a fork 16, and the like, which are adapted to follow the elevation of the platform 6.

Next, a description will be given of a lifting and lowering adjustment device for raising and lowering the platform 6 of the order picker 1 described above. As shown in FIG. 9, the oil tank 17 includes:
A hydraulic pump 19, which is driven by a pump motor 18 connected to a battery B via a pump contactor C, is connected to an ascending pipe 20 provided on the way and a shockless valve 2.
1 is connected to a descending pipe 22 provided on the way. A cylinder pipe 24 connects the junction 23 between the ascending pipe 20 and the descending pipe 22 to the two lift cylinders 4a and 4b.

[0007] A flow regulator valve 25 is provided in the cylinder pipe 24. When the platform 6 is lowered, the flow regulator valve 25 flows out of the lift cylinder 4 even if the load applied to the platform 6 changes. This is for keeping the amount of oil to be constantly constant. Also, two lift cylinders 4a and 4
b, a safety down valve 26 is attached to one of the cylinder bottoms.
Reference numeral 6 indicates that when the flow regulator valve 25 breaks down or the piping is damaged and a sudden drop occurs, the amount of oil is controlled to limit the lowering speed of the lift cylinder 4. Further, a relief valve 28 is provided in a communication pipe 27 that connects the ascending pipe 20 and the descending pipe 22, and the relief valve 28 adjusts the pressure of the hydraulic oil pumped from the hydraulic pump 19. Thus, unnecessary rise in pressure is eliminated to prevent breakage of the elevation adjustment device.

Here, the operation of the above-described lifting / lowering adjusting device will be described. First, by turning on the push button switch 10 for raising, the pump contactor C is turned on, the pump motor 18 is rotated, and the hydraulic pump 19 is continuously driven. As a result, a predetermined amount of hydraulic oil is continuously supplied from the oil tank 17 to the lift cylinder 4 through the ascending pipe 20, and the rod 4a of the lift cylinder 4
A and 4bA are continuously pushed up at a predetermined speed. as a result,
The inner lift (not shown) of the mast 5 rises at a predetermined speed, and accordingly, the platform 6 also rises. Thereafter, when the platform 6 reaches a desired height, the pump contactor C is turned off by turning off the raising push button switch 10 to stop the hydraulic pump 19, and the flow of hydraulic oil in the raising pipe 20. To stop the platform 6 at the desired height.

In addition, the lifting pipe 2
Backflow to zero is prevented by check valve 29,
Backflow from the lift cylinder 4 to the descending pipe 22 is prevented by positioning the spool 21a of the shockless valve 21 on the closing side via the solenoid 21b.

Next, when the lowering push button switch 11 is turned on, the solenoid 21b is driven, and the spool 21a of the shockless valve 21 is gradually positioned on the open side, whereby the lowering pipe 22 is gradually opened. The hydraulic oil in the lift cylinder 4
Through the oil tank 17 at a constant speed.
As a result, due to the weight of the platform 6, the rods 4aA and 4bA of the lift cylinder 4 continue to descend at a predetermined speed, and the inner lift (not shown) of the mast 5 and the platform 6 also keep descending. Then, Platform 6
When is at the desired height, the lower push button switch 1
1, the excitation of the solenoid 21b is released, and the spool 21a is positioned on the closed circuit side.
The flow of hydraulic oil in 2 is stopped, and the platform 6 is stopped at a desired height. Therefore, the operator can stop the platform 6 at an arbitrary height by turning on / off the push button switches 10 and 11.

[0011]

However, the conventional order picker lifting / lowering adjusting device has the following problems because it is configured as described above. That is, the ascending speed of the platform 6 in the conventional elevating device is determined in advance by the discharge amount of the hydraulic pump 19, and the descending speed is determined by the weight of the platform 6, the shockless valve 21 and the flow regulator valve. The driver 6 turns the platform 6 up and down by turning on and off the up and down push button switches 10 and 11 because the structure is preliminarily determined by the structure of 25 (not half-open). It was only possible to stop the vehicle at an arbitrary height, and it was not possible to control the elevation speed of the platform 6 by the driver's intention. That is, in the conventional lifting and lowering adjustment device, the platform 6 can only be raised and lowered at a constant speed at all times. As a result, the platform 6 is slightly raised when positioning the fork 16 or taking out the load at a high place. Inching operation to move up and down is difficult,
It has been extremely difficult to set the ON / OFF timing of the push button switches 10 and 11. When the push button switches 10 and 11 are repeatedly turned on and off to perform an inching operation, the position of the platform 6 is not easily determined, and the platform 6 fluctuates.
Workers were uncomfortable. Further, since the speed of raising and lowering the platform 6 is always constant, there is a problem that the raising and lowering of the platform 6 cannot be performed quickly according to the intention of the operator.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. In particular, it is an object of the present invention to provide an order picker elevating speed adjusting device capable of appropriately changing the elevating speed of a platform. Aim.

[0013]

SUMMARY OF THE INVENTION According to the present invention, there is provided an ascending / descending speed adjusting apparatus for an order picker, which raises a platform by flowing hydraulic oil from an oil tank through an ascending pipe provided with a hydraulic pump. hydraulic oil through the down pipe to the order picker having a lift cylinder for lowering the its own weight Pratt <br/> home by flowing out to the oil tank, the merging portion of the rising pipe and a falling pipe High speed low terminal and high speed
Side terminal, lower speed side terminal for lowering and higher speed side terminal.
Number of input terminals, slidably mounted and their positions
A spool that controls the amount of oil flowing through the junction according to
When a current is input to any of the multiple input terminals,
An electromagnet that moves the spool to a position corresponding to the force terminal
Proportional control valve having a plurality of
It is obtained by an operation switch for inputting a current to one of the input terminals.

[0014]

In the lifting / lowering speed adjusting device of the order picker according to the present invention, by appropriately selecting the operation switch, the electric signal sent to the proportional control valve disposed at the junction of the ascending pipe and the descending pipe is transmitted. Change, and accordingly,
The opening and position of the spool are controlled, and as a result, the amount of oil flowing from the oil tank to the lift cylinder and the amount of oil flowing from the lift cylinder to the oil tank change according to the operator's intention, and the platform lifting speed To change.
That is, the proportional control valve is raised by selecting the operation switch.
Low-speed terminal and high-speed terminal for
Current is input to one of the input terminals
The electromagnet moves the spool to the position corresponding to its input terminal.
To move the ascending pipe and the descending pipe together.
The amount of oil flowing through the flow section is controlled.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the order picker lifting / lowering speed adjusting device according to the present invention will be described in detail with reference to the drawings. Note that the same or equivalent parts as those in the conventional example are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 1, an operation panel 7 is provided on the platform 6, and the operation panel 7 has various devices necessary for operating the order picker 1.
For example, on the front surface of the operation panel 7, a loading / unloading lever switch 30, which is an example of an operation switch for determining the elevating speed of the platform 6, is disposed. As shown in FIG. By tilting the neutral position A back and forth, it is possible to switch between an ascending-side low-speed position D, an ascending-side high-speed position E, a descending-side low-speed position F, and a descending-side high-speed position G. . Then, corresponding to the positions D to G of the lever switch 30, the switch units S1, S2, S3, S4 are provided in the switch box 31.
Is provided.

Next, an elevation speed adjusting device for elevating the platform 6 of the order picker 1 will be described. As shown in FIG. 3, a hydraulic pump 19 driven by a pump motor 18 connected to a battery B via a pump contactor C is provided in the oil tank 17.
To the ascending pipe 20 and the descending pipe 22
And are connected. A proportional control valve 32 that adjusts the elevating speed of the lift cylinder 4 while controlling the amount of oil in accordance with the opening degree of the spool is provided at a junction 23 between the ascending pipe 20 and the descending pipe 22. . In addition, the proportional control valve 3
Two to two lift cylinders 4 a and 4 b are connected by a cylinder pipe 24. The proportional control valve 32 is a current suppression type solenoid valve equipped with an amplifier.

The proportional control valve 32 is provided with a spool 35 slidably pulled to a predetermined position by an ascending drive electromagnet 33 and a descending drive electromagnet 34 provided at both ends. This spool 35 is connected to the cylinder pipe 2
And a first control unit 35a for closing the communication between the cylinder pipe 24 and the descending pipe 22 at the same time as allowing the cylinder pipe 24 and the descending pipe 22 to communicate with each other at a predetermined opening degree. A second control unit 3 that allows communication with the opening degree and simultaneously blocks communication between the cylinder pipe 24 and the ascending-side pipe 20.
5b, a cylinder pipe 24 and an ascending and descending pipe 20,
And a third control unit 35c that does not allow communication with the control unit 22. Therefore, by pulling the spool 35 with the ascending drive side electromagnet 33, the cylinder pipe 24 and the ascending pipe 20 can be communicated via the first control unit 35a,
Further, by pulling the spool 35 by the descending drive side electromagnet 34, the cylinder pipe 2 is pulled through the second control unit 35b.
4 and the down pipe 22 can be communicated.

The ascending drive side and descending drive side electromagnets 33, 34 are connected to high-speed terminals 36, 37 for inputting a large current to generate a large magnetic force, and input a small current to generate a small magnetic force. Low-speed side terminal 3 for generating
8, 39 are provided respectively. These terminals 3
6 to 39 are connected to switch units S1 to S4 in the switch box 31 via wires 40 to 43. Specifically, the switch section S1 and the low-speed side terminal 38 are connected to the wiring 4
2, the switch section S2 and the high-speed terminal 36
Are connected via a wiring 40, the switch section S3 and the low-speed side terminal 39 are connected via a wiring 43, and the switch section S4 and the high-speed side terminal 37 are connected via a wiring 41. However, as shown by the dashed line in FIG. 5, the wirings 40 to 43 are disposed in the mast 5 so that the wirings 40 to 43 are not exposed to the outside.

Here, the operation of the above-described lifting / lowering speed adjusting device will be described. First, when the loading lever switch 30 is switched from the neutral position A to the ascending side low speed position D, the switch section S1 is turned on, the pump contactor C is turned on, the pump motor 18 is rotated, and the hydraulic pump 19 is turned on. Keep driving. At the same time, a small current is input to the low speed terminal 38 to excite the ascending drive electromagnet 33.
As a result, the first control portion 35a of the spool 35 is pulled by a predetermined amount by the electromagnet 33, and
And the ascending pipe 20 are opened to a half-open state (the communication between the cylinder pipe 24 and the descending pipe 22 is, of course, closed). Therefore, the amount of oil flowing through the proportional control valve 32 decreases, and the lift cylinder 4 is raised at a low speed, and the platform 6 is raised at a low speed. Then, when the platform 6 reaches the predetermined height, the loading lever switch 30 is returned to the neutral position A, whereby the spool 35 returns to the neutral position, and the third control unit 35
c and the ascending and descending pipe 2 with the cylinder pipe 24
Communication with 0,22 is blocked, stopping the platform 6 from rising.

Next, when the cargo handling lever switch 30 is switched to the high speed position E on the ascending side, the switch section S2 is turned on, the hydraulic pump 19 is driven, and a large current is input to the high speed side terminal 36, so that the ascending drive is performed. The side electromagnet 33 is excited. As a result, the first control portion 35a of the spool 35 is pulled by a predetermined amount by the electromagnet 33, and at the same time, the cylinder pipe 24, the ascending pipe 20, and the opening are fully opened (in addition,
Naturally, the cylinder pipe 24 and the descent pipe 22
Communication has been blocked). Therefore, the proportional control valve 32
The amount of oil flowing therethrough increases, and the lift cylinder 4 is raised at a high speed, and the platform 6 is raised at a high speed. Then, when the platform 6 has reached the predetermined height, the loading lever switch 30 is returned to the neutral position A, thereby stopping the elevation of the platform 6.

Next, when the loading lever switch 30 is switched to the lower speed position F on the lower side, the switch section S3 is turned on, a small current is input to the lower speed terminal 39, and the lower drive side electromagnet 34 is excited. As a result, the second control portion 35b of the spool 35 is pulled by a predetermined amount by the electromagnet 34, and at the same time, the opening degree of the cylinder pipe 24 and the descent pipe 22 is set to a half-open state (the cylinder pipe 24 The communication between the pipe and the ascending pipe 20 is closed.) Therefore, since the amount of oil flowing through the proportional control valve 32 is reduced, a small amount of hydraulic oil flows out of the lift cylinder 4 to the oil tank 17 per unit time due to the weight of the platform 6, and the lift cylinder 4 is lowered at a low speed. The platform 6 is lowered at a low speed. Then, when the platform 6 reaches the predetermined height, the lowering of the platform 6 is stopped by returning the cargo handling lever switch 30 to the neutral position A.

Next, when the loading lever switch 30 is switched to the descending high-speed position G, the switch section S4 is turned on, a large current is input to the high-speed terminal 37, and the descending drive-side electromagnet 34 is excited. As a result, the second control portion 35b of the spool 35 is pulled by a predetermined amount by the electromagnet 34, and at the same time, the opening degree of the cylinder pipe 24 and the descent pipe 22 is fully opened (note that the cylinder pipe 24 The communication between the pipe and the ascending pipe 20 is closed.) Accordingly, the amount of oil flowing through the proportional control valve 32 increases, so that a large amount of hydraulic oil flows from the lift cylinder 4 to the oil tank 17 per unit time due to the weight of the platform 6 and lowers the lift cylinder 4 at high speed. Lower the platform 6 at high speed. Then, when the platform 6 reaches the predetermined height, the lowering of the platform 6 is stopped by returning the cargo handling lever switch 30 to the neutral position A.

Another example of the operation switch 30 is as follows.
A push button type configuration as shown in FIG. 4 can be employed. That is, on the operation panel 44, an ascending low speed push button switch 45, an ascending high speed push button switch 46, a descending low speed push button switch 47, a descending high speed push button switch 48, and an ascending / descending stop The switch 49 may be provided. Note that reference numeral 1
Reference numeral 3 denotes an accelerator lever capable of moving the order picker 1 back and forth in the direction of rotation and changing the traveling speed according to the amount of rotation.

The present invention is not limited to the above-described embodiment. It goes without saying that, for example, by increasing the number of the switch sections, the vertical speed can be subdivided. Further, by adopting a stepless switch portion as the switch portion, the platform 6 can be changed according to the tilt angle of the loading lever switch 30 as shown in FIG.
Can be controlled steplessly.

[0026]

The lifting / lowering speed adjusting device of the order picker according to the present invention is configured as described above, so that the following effects can be obtained. I.e. low for ascent
High-speed terminal and high-speed terminal, and low-speed terminal and high-speed terminal for descending
Multiple input terminals consisting of side terminals and slidably mounted
Control the amount of oil flowing through the junction according to the position
Current to one of the input terminals and the spool
When the spool is pressed, the spool moves to the position corresponding to the input terminal.
Moving a proportional control valve having an electromagnet and
Installed at the junction with the downcoming pipe, and the operating position of the operation switch
Current to one of the multiple input terminals of the proportional control valve depending on
By operating the operation switch, the elevation speed of the platform can be controlled between the high speed side and the low speed side according to the driver's intention .
For example, by performing the inching operation to raise or lower the platform slightly on the low speed side ,
The platform can be securely stopped at any position. Therefore, it is possible to eliminate a problem that the position of the platform is not easily determined and the platform rattles and gives an uncomfortable feeling to the operator. Also ,
By using the high-speed side, it is possible to raise and lower the platform quickly according to the worker's intention,
It has an excellent effect that the efficiency of cargo handling work can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a platform on which an operation switch for driving a lifting / lowering speed adjusting device of the present invention is disposed.

FIG. 2 is a side view showing the operation switch of FIG. 1;

FIG. 3 is a hydraulic circuit diagram schematically showing a lifting speed adjusting device according to the present invention.

FIG. 4 is a front view showing another embodiment of the operation switch.

FIG. 5 is a side view showing an order picker provided with the elevating speed adjusting device of the present invention.

FIG. 6 is a side view showing a conventional order picker.

FIG. 7 is a perspective view showing a conventional operation panel.

FIG. 8 is a front view showing a conventional cargo handling operation unit.

FIG. 9 is a hydraulic circuit diagram showing a conventional elevating / lowering adjusting device for an order picker.

[Explanation of symbols]

4 lift cylinder, 6 platform, 17 oil tank, 19 hydraulic pump, 20 ascent pipe, 22
... down pipe, 23 ... junction, 24 ... cylinder pipe, 3
0: operation switch (loading lever switch), 32: proportional control valve, 35: spool, 35a: first control unit, 35
b ... second control unit.

Claims (1)

(57) [Claims] 1. A through the rising pipe which is disposed in the middle of the hydraulic pump with raising the platform by introducing the working oil from the oil tank, the hydraulic oil through the down pipe by flowing out to the oil tank in order picker with a lift cylinder to lower the platform by its own <br/> weight, disposed of the merging portion with the descending pipe and the rising pipe
Low-speed terminal and high-speed terminal for ascending and low-speed terminal for descending
Multiple input terminals consisting of side terminals and high-speed side terminals, and sliding
Freely furnished and flows through the junction depending on its position
Spool that controls the amount of oil to be applied and multiple input terminals
When a current is input to the
A proportional control valve having an electromagnet for moving the spool, and any one of the plurality of input terminals depending on the operation position thereof.
A lift speed adjusting device for an order picker, comprising: an operation switch for inputting a current .