JP2011051769A - Safety device for cargo handling work of reach stacker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform safe cargo handling work, even when an eccentric load is caused by an interlock controller. <P>SOLUTION: This safety device for the cargo handling work is provided with the interlock controller 61 for respectively regulating the rising, lowering and extension of a boom when an actual load of a container exceeds an allowable load, and regulating the rising, lowering and extension of the boom when a spreader exceeds a side shift limit, by determining the actual load of the container from an actual inclination of the boom, the length of the boom and hydraulic pressure of an extension side oil chamber of a lifting cylinder 23, by arranging a cargo holder at the tip of the freely derricking/freely expandable boom via a side shift device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a safety device for cargo handling work of a reach stacker.

  For example, Patent Document 1 discloses a side shift device that limits the amount of side shift by detecting left and right eccentric loads of a load in a forklift.

Japanese Patent No. 2563219

  However, there has been no suggestion of safety with respect to an eccentric load with respect to a reach stacker in which a spreader as a load holding tool is provided at the tip of a boom supported in a undulating and telescopic manner from a vehicle body.

  An object of the present invention is to provide a safety device for cargo handling work of a reach stacker that can cope with an eccentric load of the load of the reach stacker.

According to the first aspect of the present invention, a boom that is supported up and down around a horizontal axis so as to be extendable and retractable is provided on the vehicle body, and a side shift position is adjustable at the tip of the boom via a side shift device. A safety device for cargo handling work of a reach stacker comprising a load holding tool, an elevating cylinder for raising and lowering the boom, a telescopic cylinder for extending and retracting the boom, and a shift driving device for driving the side shift device,
A boom angle detector for detecting the tilt angle of the boom;
A boom length detector for detecting the length of the boom;
A cylinder oil pressure detector for detecting the oil pressure in the extension side oil chamber of the elevating cylinder;
A side shift detector for detecting a side shift amount of the load holding device;
An interlock controller capable of regulating the operation of the elevating cylinder and the telescopic cylinder and the shift drive device,
The interlock controller includes an actual boom inclination angle detected by the boom angle detector, an actual boom length detected by the boom length detector, and a lift cylinder detected by the cylinder hydraulic pressure detector. The actual load of the load is calculated from the hydraulic pressure of the extension side oil chamber, and when the actual load of the load exceeds the allowable load, the boom is lifted, lowered, and extended, and the load holding device is controlled by the side shift detector. Is detected to exceed the side shift limit, the boom is raised, lowered and extended.

  According to a second aspect of the present invention, in the configuration of the first aspect, the interlock controller is configured so that any one of the actual load of the load, the actual inclination angle of the boom, and the actual lift height of the load holder exceeds the respective shift set values. And the shift drive device is configured to restrict the movement of the load toward the side where the eccentric load increases.

  According to the invention described in claim 1, when the actual load of the load calculated from the detected values of the boom angle detector, the boom length detector, and the cylinder hydraulic pressure detector exceeds a preset allowable load, The interlock controller regulates the boom up, down, and extension to allow only the boom to contract, and further regulates the boom up, down, and extension when the load retainer exceeds the side shift limit. Thus, by only allowing the boom to contract, even when an eccentric load is generated on the load held by the load holding tool by the side shift, the cargo handling operation can be performed safely.

  According to the invention described in claim 2, the actual load of the load exceeds the shift set load, the tilt angle of the boom exceeds the shift set tilt angle, or the lift height of the load holding tool exceeds the shift set lift height. Then, the side shift device can be regulated by the interlock controller to regulate the shift of the load eccentricity to the increasing side, and the safety against the eccentric load of the load can be further enhanced.

It is a side view which shows the Example of the safety device for cargo handling work of the reach stacker based on this invention, and shows the structure of a reach stacker. It is a perspective view which shows the spreader of a reach stacker. It is a block diagram which shows a safety device. It is a circuit diagram which shows a safety device. It is a flowchart which shows operation | movement of a safety device. It is a graph explaining the relationship between a rated load curve and the amount of side shift.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, a self-propelled vehicle body 11 having left and right front wheels 12 and left and right rear wheels 13 includes an engine 14, a traveling device driven by the engine 14, and a working hydraulic unit. The cargo handling work device 15 is mounted.

[Handling equipment]
The cargo handling work device 15 is supported by a boom support portion 16 installed at the rear portion of the vehicle body 11 so as to be able to undulate and tilt in the vertical direction via a support shaft 17 in the vehicle width direction (horizontal direction), and to extend and contract. The side shift position is supported via a side shift device 19 on a boom 21 and a suspension base 18 that is swingable around a horizontal axis center and pivotally provided at the tip of the boom 21. A spreader (load holding tool) 22 capable of holding the container (load) 20 is provided. A pair of left and right lifting cylinders 23 for tilting and raising the boom 21 in the up and down direction are installed on both left and right sides of the vehicle body 11, and a telescopic cylinder 24 for expanding and contracting the boom 21 is housed inside the boom 21.

  The boom 21 is configured to be extendable and contractable by a rear boom 31 on the base end side and a top boom 32 that is fitted inside the rear boom 31 so as to be retractable from the rear boom 31. The suspension base 18 includes a base portion 35 that is swingably supported by a suspension member 33 provided at the distal end portion of the top boom 32 via a horizontal pin 34 in the width direction, and the base portion 35. The base portion 35 is provided by a damping cylinder 38 that is provided between the suspension member 33 and the base portion 35, and includes a shift support base 37 that is supported so as to be rotatable around a vertical axis through a turning device 36. Can be adjusted. The turning device 36 includes a ring gear 36a attached to the shift support base 37, a pinion 36b meshed with the ring gear 36a, and a turning motor 36b provided on the base portion 35 to rotationally drive the pinion 36b. .

  In the spreader 22, a right beam member 42R and a left beam member 42L are slidably fitted within a predetermined range in a square pipe-shaped spreader body 41, and front and rear beam members are provided at the front ends of the right beam member 42R and the left beam member 42L. A pair of front and rear twist lock devices 44 and 44 are provided via 43 and 43, respectively. In addition, a cylinder (not shown) for moving the right beam material 42R and the left beam material 42L in and out of the spreader main body 41 is built in, so that the position of the twist lock device 44 can be adjusted to correspond to the size of the container. Is done.

  The side shift device 19 that slides the spreader 22 to the left and right is formed in a gate-like cross section in which a shift support base 37 is externally fitted to the upper surface and front and rear side surfaces of the spreader body 41, while Shift rails 45 are attached respectively. The shift support base 37 is provided with slide plates (not shown) for supporting the shift rail 45 from below, and the spreader 22 is supported on the shift support base 37 so as to be movable in the vehicle width direction. Further, side shift cylinders (side shift drive devices) 47 in which piston rods are connected to the shift support base 37 are provided on the front and rear surfaces of the spreader body 41, respectively, so that the spreader 22 can be side-shifted in the vehicle width direction. it can.

  As shown in FIG. 3, the cargo handling work device 15 is provided with a working hydraulic device 51 that supplies and discharges hydraulic pressure to and from the lifting cylinder 23, the telescopic cylinder 24, and the side shift cylinder 47. A driver's seat of the vehicle body 11 is provided with a work operation lever (joystick lever) 25 for operating both the cargo handling cylinders 23 and 24 and a side shift switch 26 for operating the side shift cylinder 47. The cargo handling work device 15 includes a damping cylinder 38, a turning motor 36b, a fine adjustment cylinder, and a drive cylinder for the twist lock device 44, which are omitted in FIG.

[Work hydraulic system]
As shown in FIGS. 3 and 4, the working hydraulic device 51 has a hydraulic pilot lift that supplies and discharges the pressure oil sent from the hydraulic pump P <b> 1 to the lift cylinder 23 by operating the work control lever 25. Operation of the hydraulic control valve 53 and the hydraulic control valve 53 for supplying and discharging the hydraulic oil sent from the hydraulic pump P1 to the expansion cylinder 24 by operating the operation control lever 25 and the side shift switch 26. Thus, there is provided an electromagnetic shift control valve (proportional control valve) 54 for supplying and discharging the pressure oil sent from the hydraulic pump P2 to the side shift cylinder 23.

  Then, an electromagnetic lift lock valve 56U is interposed in a pilot pipe for supplying pilot pressure from the lift pilot valve 55U operated by the work operation lever 25 to the lift operation portion of the lift control valve 52. An electromagnetic lowering lock valve 56D is interposed in a pilot pipe that supplies pilot pressure from the valve 55D to the lowering operation portion of the lifting control valve 52. Further, an electromagnetic extension lock valve 56F is interposed in a pilot pipe for supplying pilot pressure from the extension pilot valve 55F operated by the work operation lever 25 to the extension operation portion of the expansion / contraction control valve 53, and the contraction pilot valve. An electromagnetic contraction lock valve 56R is interposed in a pilot pipe for supplying pilot pressure from 55R to the contraction operation portion of the expansion / contraction control valve 53.

  Further, shift lock relays (b contacts) 58R and 58L are interposed in an electric circuit for sending an operation signal from the side shift switch 26 to the operation portion of the shift control valve 54, respectively.

  The working hydraulic device 51 detects a boom angle detector 27 that detects the tilt angle of the boom 21, a boom length detector 28 that detects the length of the boom 21, and the hydraulic pressure in the extension chamber of the lift cylinder 23. A cylinder oil pressure detector 29 and a side shift detector 30 for detecting the side shift amount of the spreader 22 are provided.

  As shown by a solid line in FIG. 2, the first example of the side shift detector 30 includes left and right detection pieces 49R and 49L respectively installed at predetermined left and right side shift limits, and the left and right of the shift support base 37. Left and right detection pieces 49R and 49L that are attached to both sides and can be detected by shift limit proximity switches 48R and 48L, respectively.

  The second example of the side shift detector 30 is configured by providing a shift distance detector 50 capable of detecting the side shifted distance, as indicated by a virtual line in FIG. The shift distance detector 50 is attached to the spreader main body 41, and is composed of a drum that winds up a detection cord connected to the shift support base 37 so as to be freely unwound and a rotary encoder that detects the rotation angle of the drum. Of course, as the shift distance detector, a potentiometer provided in the side shift cylinder 47 and detecting the amount of piston rods withdrawing and retracting can be used.

[Interlock controller]
An interlock controller (PLC) 61 that regulates the rise, fall, and extension of the boom 21 and regulates the side shift of the spreader 22 in order to prevent equipment breakdown and overturning of the vehicle body 11 due to an excessive load during cargo handling work. Is provided. In this interlock controller 61, the input unit 62 sends the storage unit 63 the allowable load that is the maximum load that can be held by the spreader 22 corresponding to the length and inclination angle of the boom 21, and the side shift beyond the side shift limit. Possible side shift set load (shift set value), side shift set boom length (shift set value) of the boom 21 that can be side shifted beyond the side shift limit, and side shift possible side shift beyond the side shift limit The shift set height (shift set value) is input and stored.

  In the interlock controller 52, the tilt angle of the boom 21 detected by the boom angle detector 27, the length of the boom 21 detected by the boom length detector 28, and the hydraulic pressure detected by the cylinder oil pressure detector 29. Based on the above, the actual load of the container 20 held by the spreader 22 is calculated. When the actual load exceeds the allowable load, the interlock relays (a contacts) 57U, 57D, and 57F are operated to turn on the lock valves 56U, 56D, and 56F for lifting, descending, and extending, respectively ( The boom 21 is lifted, lowered, and extended by the work operation lever 25, and only the contracting operation is enabled. Further, when the actual load exceeds the allowable load and exceeds the side shift limit detected by the left and right shift limit proximity switches 48R and 48L, the interlock relays 57U, 57D and 57F are operated to raise and lower. Each of the extension lock valves 56U, 56D, and 56F is turned on (blocked), and the boom 21 is controlled to be lifted, lowered, and extended in the same manner as the boom 21 by the work operation lever 25, and only the contracting operation is enabled. .

  In the case where the shift distance detector 50 is provided, as shown in FIG. 5, the side shift limit that regulates the raising, lowering, and extension of the boom 21 is set at a plurality of positions corresponding to the actual load of the container 20. Can be set.

  In the interlock controller 52, when the actual load exceeds the side shift set load, the length of the boom 21 becomes longer than the side shift set boom length, or the height of the spreader 22 becomes equal to or higher than the side shift set lift. The shift lock relay (b contact) 58R or 58L on the side where the eccentric load increases is turned on to restrict the side shift to the side where the eccentric load increases.

[Operation of interlock controller]
The operation of the interlock controller 61 will be described with reference to FIG.
1) The boom angle detector 27 detects the tilt angle of the boom 21 and the boom length detector 28 detects the length of the boom 21 (STEP.11). The current allowable load is obtained from the tilt angle and length of the boom 21 (STEP.12). Further, the cylinder oil pressure detector 29 detects the oil pressure in the extension chamber of the elevating cylinder 23 (STEP.13), and calculates the actual load of the container 20 from the oil pressure of the elevating cylinder 23 and the tilt angle and length of the boom 21 (STEP.13). 14).

  2) Compare the actual load and allowable load of the container 20 (STEP.15). If the actual load is larger than the allowable load, operate (turn on) the interlock relays 57U and 57D to increase and decrease The lock valves 56U and 56D are respectively operated to the II position (OFF side) (STEP.17), the lifting control valve 52 is held at the neutral position to stop the supply of hydraulic pressure to the lifting cylinder 23, and for interlocking The relay 57F is operated (ON) to operate the extension lock valve 56F to the II position (OFF side) (STEP.16). As a result, the expansion / contraction control valve 53 is not operated even when the work operation lever 25 is operated to the expansion side, and the expansion / contraction control valve 53 is operated to the contraction position only when operated to the contraction side, and the expansion / contraction cylinder 23 contracts. Hydraulic pressure is supplied only to the chamber, and the boom 21 is contracted (STEP.17).

  3) When one of the left and right shift limit proximity switches 48R and 48L detects the detection piece 49R or 49L beyond the side shift limit of the spreader 22 (STEP.18), STEPs 16 and 17 are performed.

  4) Compare the actual load with the preset side shift set load (STEP.19). If the actual load is larger than the side shift set load, the shift lock relay 58R or 58L on the side where the eccentric load increases. Is turned on (STEP. 20), and the extension operation or the contraction operation on the side where the eccentric load of the shift control valve 54 increases is regulated. Here, the previous allowable load and the side shift set load can be set to be the same. Thereby, even if the side shift switch 26 is operated so that the spreader 22 shifts to the side where the eccentric load increases, the shift control valve 54 is not interlocked and shifted. Further, only when the side shift switch 26 is operated to the side where the eccentric load is reduced, the shift control valve 54 is operated, the side shift cylinder 47 is extended or contracted, and the eccentric load of the spreader 22 is shifted in the direction of decreasing. (STEP.21).

  5) The length of the boom 21 detected by the boom length detector 28 is compared with a preset boom setting boom length of the boom 21 (STEP.22), and the boom 21 is longer than the shift setting boom length. STEP.20 and 21 are performed.

  6) The lift height of the spreader 22 obtained from the tilt angle and length of the boom 21 is compared with a preset lift setting height of the spreader 22 (STEP.23), and the obtained lift height is set as a shift. If it is higher than the lift, STEP.22 and 23 are performed.

  7) The operation lever 25 is operated to raise and lower the boom 21, and the boom 21 is expanded and contracted to perform a cargo handling operation (STEP. 24). Further, the side shift switch 26 performs side shift of the spreader 22. (STEP.25), stacking work, stacking work, hollowing out, dropping work of the container 20 is performed.

[Second example of side shift detector]
When the shift distance detector 50 is provided in the side shift detector 30, a plurality of side shift limits can be set corresponding to the actual load as shown in FIG. That is, when the actual load is in the range of the maximum load and the load A, the side shift limit a is set, and when the actual load is in the range of the load A and the load B, the side shift limit b is set. In the range of C, the side shift limit c is set. Thereby, the range in which the spreader 22 can be side-shifted is widened, and the cargo handling operation can be performed safely and efficiently.

[Effect of Example]
According to the above embodiment, when the actual load of the load calculated from the tilt angle of the boom 21 and the length of the boom 21 and the hydraulic pressure in the extension side oil chamber of the elevating cylinder 23 exceeds the allowable load, the interlock controller 61 The boom 21 is restricted from rising, lowering, and extending to allow only the boom 21 to contract, and when the spreader 22 exceeds the side shift limit, the boom 21 is restricted from rising, lowering, and extending, respectively. By enabling only the contraction of the container, even when an eccentric load is generated in the container 20 held by the spreader, the cargo handling operation can be performed safely.

  Further, when the actual load of the load exceeds the shift set load, the boom inclination angle exceeds the shift set angle, or the actual lift height of the spreader exceeds the shift set lift height, the interlock controller 61 causes the side shift cylinder 47 to move. Can be prevented from being side-shifted to the side where the eccentric load increases, and further, the load can be prevented from increasing, so that the safety against the eccentric load of the load can be further improved.

DESCRIPTION OF SYMBOLS 11 Car body 15 Cargo handling work device 19 Side shift device 20 Container 21 Boom 22 Spreader 23 Lifting cylinder 24 Telescopic cylinder 25 Work operation lever 26 Side shift switch 27 Boom angle detector 28 Boom length detector 29 Cylinder oil pressure detector 30 Side shift detection Device 36 swivel device 37 shift support base 44 twist lock device 45 shift rail 47 side shift cylinders 48R, 48L shift limit proximity switch 49R, 49L detection piece 50 shift distance detector 51 hydraulic control device 52 lift control valve 53 telescopic control Valve 54 Shift control valve 56U Lifting lock valve 56D Lowering lock valve 56F Extension lock valve 56R Contraction lock valve 57U Interlock relay 57D Inter Click for relay 57F interlock relay 57R interlock relay 58R shift lock for a relay 58L shift lock for the relay 61 interlocking controller

Claims (2)

A boom that is supported by a vehicle body so that it can be raised and lowered around a horizontal axis, a load holding tool that is provided at the tip of the boom via a side shift device so that the side shift position can be adjusted, and the boom. A safety device for cargo handling work of a reach stacker comprising an up-and-down lifting cylinder, an expansion / contraction cylinder that expands and contracts the boom, and a shift driving device that drives the side shift device,
A boom angle detector for detecting the tilt angle of the boom;
A boom length detector for detecting the length of the boom;
A cylinder oil pressure detector for detecting the oil pressure in the extension side oil chamber of the elevating cylinder;
A side shift detector for detecting a side shift amount of the load holding device;
An interlock controller capable of regulating the operation of the elevating cylinder and the telescopic cylinder and the shift drive device,
The interlock controller includes an actual boom inclination angle detected by the boom angle detector, an actual boom length detected by the boom length detector, and a lift cylinder detected by the cylinder hydraulic pressure detector. The actual load of the load is calculated from the hydraulic pressure of the extension side oil chamber, and when the actual load of the load exceeds the allowable load, the boom is lifted, lowered, and extended, and the load holding device is controlled by the side shift detector. The reach stacker safety device for cargo handling work, which is configured to regulate the lifting, lowering and extension of the boom when it is detected that the vehicle has exceeded the side shift limit. Interlock controller
If any of the actual load of the load, the actual inclination angle of the boom, and the actual lift height of the load retainer exceeds the respective shift setting values, the shift drive device will restrict the movement of the load toward the side where the eccentric load increases. The reach stacker safety device for cargo handling work according to claim 1, wherein the reach stacker is configured as follows.

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