JP2575090Y2 - Forklift cargo handling control 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 forklift cargo handling control device capable of optimally synchronizing the amount of movement between a face and a vehicle body.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, in a forklift equipped with a push-pull device A, the reciprocation and retraction of the face 9 and the amount of movement of the vehicle body 1 are automatically controlled in synchronism to improve workability. Automatic cargo handling control devices are known.

In such an automatic cargo handling control device, when the synchronous switch 16 provided near the driver's seat is turned on to perform the face retraction operation, when the operator operates the accelerator 15 to move the vehicle body 1 forward, the load W Is clamped by a sheet gripper 11 and a jaw 27 provided below the face 9,
Thereafter, based on the deviation of the movement amount of the face 9 from the vehicle body 1, the retraction control is performed so that the face 9 can be synchronized with the movement amount of the vehicle body 1.

[0004]

However, in such a conventional configuration, the accelerator 16 is operated during the retraction operation of the face 9, and the seat gripper 11 moves the seat pallet 12 after the vehicle body 1 starts running forward. Clamp.

That is, as shown in FIG.
, The hydraulic motor 26 is driven to rotate, the pump P discharges pressure oil, and the electromagnetic switching valve B
Is switched to port D. As a result, the hydraulic cylinders 10 and 10 that can move the seat gripper 11 up and down are lowered, and after the descent is completed, the relief valve E set to a predetermined pressure is opened by the pressure increase in the pipeline, and the face 9 is opened. The hydraulic cylinder which can advance and retreat is contracted.

For this reason, when the seat pallet 12 is clamped, the vehicle body 1 has already traveled a considerable amount, and the deviation between the movement amount of the vehicle body 1 and the movement amount of the face becomes large, and hunting and the like occur. As a result, the control becomes unstable and the load collapses. On the other hand, after the retraction operation of the face 9 is started, the face speed increases as the stroke end of the face 9 approaches, but at the stroke end, a mechanical impact of the link mechanism occurs,
Load collapse is easy to occur.

The present invention has been devised in view of such a situation, and has as its object to optimally synchronize the amount of movement between the face and the vehicle body during the retraction operation of the face, and to reduce the impact at the stroke end of the face. It is an object of the present invention to provide a forklift cargo handling control device capable of alleviating the above.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a push forklift having a face which can be moved in and out along a platen at a front portion of a forklift, and a sheet gripper which can clamp a sheet pallet under the face. A loading control device for a forklift equipped with a pull attachment, comprising a means for detecting a movement amount of a face, and in a start state in a face reloading operation, a sheet gripper until the sheet gripper finishes clamping a sheet pallet. The maximum chopper conductivity is output to the hydraulic motor switching unit that drives the cylinder that operates the cylinder, and the reduced chopper conductivity is output to the hydraulic motor switching unit from near the stroke end of the face to the stroke end. Fork wheel with control unit It is the capital of the cargo control system.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall side view of the present invention, in which a forklift body 1 has a mast device 3 erected at a front portion thereof, and the mast device 3 has a lifting frame 4 that can be raised and lowered by a lift cylinder. It is installed.

A push-pull device 2 is mounted on the front surface of the lifting frame 4.
A frame 7, a platen 8 extending forward from a lower portion of the frame 7, and along the platen 8,
Pantograph-shaped link mechanism 6 that can be moved in and out
And a sheet gripper 11 provided below the face 9.

A piston rod of a hydraulic cylinder 5 is pivotally connected to the link mechanism 6 so that the link mechanism 6 can move forward and backward. Furthermore, the sheet gripper 11 is
By operating the piston rod of 0, the one end of the sheet pallet 12 can be clamped by the sheet gripper 11 and the jaw 27 having a substantially U-shaped cross section.

Further, one end of a wire 13 is fixed to the face 9, and the other end of the wire 13 is fixed to a reel-type face movement detecting unit 14 mounted on the frame 7. Thereby, the movement amount of the face 9 with respect to the vehicle body 1 can be detected.

Further, the sheet gripper 11 is provided with a clamp detecting section 17.
Reference numeral 7 denotes an optical sensor including a light emitting unit and a light receiving unit (not shown). The optical sensor 7 is mounted on the sheet gripper 11 and the jaw 27, respectively. 12 can be detected as being clamped.

An accelerator 15 for outputting a travel command and a synchronous switch 16 for outputting a push-pull synchronization command are provided on the body 1 of the forklift near the driver's seat. A vehicle body movement amount detector 18 for detecting the movement amount is provided.

Next, an electric block diagram of the present invention will be described with reference to FIG. The control unit 22 receives an acceleration signal 15 for outputting a traveling command of the vehicle body, a synchronization switch 16 for outputting a push-pull synchronization command, and a detection signal of a clamp detection unit 17 which can detect that the sheet gripper 11 has clamped the sheet pallet 12. Each is entered.

The movement amount signals of the face movement amount detection unit 14 that can detect the movement amount of the face 9 and the vehicle movement amount detection unit 18 that can detect the movement amount of the vehicle body are respectively compared with the comparator 20.
, And the comparator 20 outputs a deviation signal to the control unit 22.

The control unit 22 outputs a predetermined chopper conductivity to the traveling motor switching unit 23 and the hydraulic motor switching unit 25 based on these input signals in accordance with the procedure stored in the storage unit 21 in advance. Thus, the drive of the traveling motor 24 and the hydraulic motor 26 is controlled.

[0018]

The operation of the present invention configured as described above will be described. First, the operator operates the synchronous switch 1
6 is turned on (Y in step 1), and it is determined whether or not an accelerator operation is performed (step 2). If the accelerator is operated (Y in step 2), it is determined whether or not the sheet gripper 11 has finished clamping the sheet pallet 12 (step 3).

If the clamping operation has not been completed, the maximum chopper continuity is output to the hydraulic motor switching unit 25 for driving the hydraulic motor 26 (step 6), and the hydraulic cylinder 10 is extended at the maximum speed. Let it. Therefore, during this time, even if the accelerator operation is being performed, the gate signal indicating the chopper conductivity is not output to the traveling motor switching unit 23, and the vehicle body 1 stops traveling.

Thereafter, when the sheet gripper 11 finishes clamping the sheet pallet 12 based on the detection signal of the clamp detector 17 (Y in step 3), it is determined whether or not the amount of movement of the face 9 is greater than a predetermined distance (k). Is determined (step 4). Here, the distance (k) can be set according to the load handled by the forklift. For example, if the total stroke of the face 9 is 1, it can be set to about 0.7,
Other than this is acceptable.

If N in step 4, it can be determined that the face 9 has not approached the stroke end yet, and the deviation between the movement amount of the vehicle body 1 and the movement amount of the face 9 is calculated by the comparator 20, and The chopper continuity is output to the hydraulic motor switching unit 25 based on (step 5),
The hydraulic motor 26 is driven, and synchronization with the vehicle body is maintained.

Further, the chopper conductivity proportional to the accelerator is output to the traveling motor switching unit 23 (step 6), and the traveling motor 24 is driven, so that the vehicle body 1 travels.

Next, if the moving amount of the face 9 is larger than the predetermined distance (k) (Y in step 4), it is determined that the face 9 is approaching the stroke end, and the chopper reduced to the hydraulic motor switching unit 25 The conductivity is output (step 8). Thereby, the moving speed of the face 9 is reduced until the stroke end, and the shock at the stroke end is reduced.

Here, the degree of reduction can be variously set according to the load handled by the forklift, but the lower limit is set to the maximum load that can be handled by the push-pull device 2 so that the face 9 can move. Yes, the upper limit can be set arbitrarily. During this time, the moving speeds of the vehicle body 1 and the face 9 are not synchronized, but the time is extremely short, so that there is no problem.

The hydraulic circuit is the same as the conventional one, and a pump P is connected to the hydraulic motor 26 as shown in FIG.

[0026]

As described above, according to the present invention, it is possible to prevent the deviation of the movement amount between the face and the body of the forklift from increasing, so that hunting can be prevented and the synchronization between the face and the body can be improved. The workability is improved, and the collapse of the load can be prevented. In addition, until the sheet gripper finishes clamping the sheet pallet, the hydraulic motor is driven at the maximum chopper conductivity, so that the time for the sheet gripper to clamp the sheet pallet can be reduced. Furthermore, since the face speed decreases just before the stroke end of the face, mechanical shock at the stroke end can be reduced,
Load collapse can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall side view of an embodiment of the present invention.

FIG. 2 is an electrical block diagram of the embodiment of the present invention.

FIG. 3 is a flowchart of an embodiment of the present invention.

FIG. 4 is an overall side view of a conventional push-pull device.

FIG. 5 is a hydraulic circuit diagram of the push-pull device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 2 Push-pull apparatus 9 Face 11 Sheet gripper 12 Sheet pallet 14 Face movement detection part 15 Accelerator 16 Synchronous switch 17 Clamp detection part 18 Body movement detection part 20 Comparator 22 Control part

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B66F 9/00-11/04

Claims (1)

(57) [Scope of request for utility model registration] 1. A forklift carrying a forklift equipped with a push-pull attachment having a face that can be moved in and out along a platen and a sheet gripper capable of clamping a sheet pallet under the face, at a front part of the body of the forklift. A control device having means for detecting the amount of movement of the face, and in a start state in the reloading operation of the face, a hydraulic pressure for driving a cylinder for operating the sheet gripper until the sheet gripper finishes clamping the sheet pallet. Forklift comprising: a control unit that outputs the maximum chopper conductivity to the motor motor switching unit and outputs the reduced chopper conductivity to the hydraulic motor switching unit from the vicinity of the stroke end to the stroke end of the face. Cargo handling control equipment.