JPH01187198A - Positioner for spreader - Google Patents

Abstract

PURPOSE:To permit the automatic positioning of a spreader by connecting a conduit which communicates to a head side oil chamber and has a flow suppressing check valve into a pressurized oil feeding conduit for the rod side oil chamber of a hydraulic cylinder and forming a passage in which a check valve for suppressing the inflow of the oil into the rod side oil chamber, to a piston. CONSTITUTION:The rod side oil chambers for the right and left hydraulic cylinders 10 are connected with a manually operated control valve 15 through each independent working oil feeding conduit 16. The rod of the cylinder 10 is always urged in the extension direction by a spring 27. The head side oil chamber is connected to the conduit 16 through a conduit 17 having a check valve 18 for suppressing the flow to the head side. A piston 12 has a passage 25 for the communication between the both oil chambers, and a check valve 26 for suppressing the flow to the rod chamber side is installed. When one side of a positioning stopper contacts one side of a container, a contraction force acts onto the hydraulic cylinder 10 on this side, and the oil on the head side flows into the rod side, and a spreader is swung and set parallel, and positioning is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a spreader mounted on a forklift truck and used for container cargo handling, and more particularly to a device for aligning a twist lock with a hanging hole of a container. .

(Prior Art) As shown in Fig. 5, the spreader is equipped with two twist locks 2 (one type is also available) provided at both the left and right ends of the spreader frame 1, which are inserted into the hanging hole C1 of the container C. A device is provided for aligning the twist Ω-tuck 2 with respect to the hanging holes C1 (making the spreader frame 1 parallel to the container C) before loading the container.

That is, in the conventional spreader, as shown in FIG.
The spreader frame 1 is pivotally connected to a support arm 7 attached to the support arm 7 so as to be horizontally swingable, and the left and right hydraulic cylinders 10 arranged on both sides of the swing center are telescopically operated by operating a control valve 15. It is designed to swing horizontally. That is, the operator on the driver's seat operates the control valve 15 to swing the spreader frame 1 so that the stoppers 3 on both left and right sides thereof are parallel to the rear surface of the container C, thereby opening the hanging hole C1 of the container C. The twist lock 2 is aligned with respect to the position of the twist lock 2. The above-mentioned device is not only used for aligning the twist lock, but also for adjusting the orientation of the container C by horizontally swinging the spreader frame 1 when lowering the container C after transportation. Also used in cases. A swing type positioning device using such a cylinder is disclosed in, for example, Japanese Utility Model Application Publication No. 54-97975.

(Problem to be Solved by the Invention) However, in the conventional spreader described above, the parallelism of the stopper 3 with respect to the container C is adjusted by operating the control valve 15 on the driver's seat to expand and contract the left and right hydraulic cylinders 10. This is an adjustment method that relies on the operator's intuition, so it is easy for the adjustment to go awry, and the work requires skill and nerves. It was a bad thing. If the work result is that they are actually not parallel, one stopper 3 will hit the container C first when the vehicle moves forward toward the container, so if the hit is strong, an excessive force will be applied to the stopper 3. There is a possibility that the stopper 3 or the container C may be damaged.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to improve work efficiency by automatically aligning a spreader frame with respect to a container.

(Means for Solving the Problems) In order to solve the above problems, the present invention has a spreader frame attached to a lift bracket so as to be horizontally swingable, and a spreader frame with respect to a container on both sides of the attachment portion. In the spreader, the spreader is provided with a stopper for alignment and a hydraulic cylinder for swinging the spreader frame, and the spreader frame is moved horizontally by switching a control valve and operating the hydraulic cylinders. The hydraulic oil supply conduit is always biased in the extension direction by a spring, and is used to supply hydraulic oil from the hydraulic pump to the rod side oil chamber of the hydraulic cylinder. One end leads to the head side oil chamber and there is a head A pipe line with a check valve for preventing oil from flowing into the side oil chamber is connected, and the piston of the hydraulic cylinder is equipped with a check valve that prevents oil from flowing from the head side oil chamber to the rod side oil chamber. The gist is that a passageway or oriswiss was provided.

(Function) The control valve is always placed in the neutral position,
When the spreader is advanced toward the container in order to lift the container in this state, unless the spreader is parallel to the container, one of the left and right stoppers on the spreader frame will come into contact with the front surface of the container first.

Due to this contact, an external force in the direction of contraction acts on the hydraulic cylinder on the contact side, and this external force causes the oil in the head side oil chamber to flow into the rod side oil chamber through the check valve in the conduit. , the hydraulic cylinder contracts against the spring. That is, the spreader frame is horizontally swung in a direction parallel to the container, and when the stopper on the opposite side abuts the front surface of the container, the spreader becomes parallel to the container.

Further, when the container is lifted, the hydraulic cylinder in the contracted state is returned to the initial state by the spring, so the spreader frame swings in the opposite direction during alignment and returns to the original position v1 parallel to the lift bracket.

(Example) Hereinafter, an example of the present invention will be specifically described based on the drawings. 1 in the figure is a spreader frame that extends horizontally in the left-right direction, and 44
It is equipped with twist locks 2 at the left and right rear ends (body #
) is equipped with a stopper 3 for positioning. In addition,
The stopper 3 is normally provided almost directly behind the twist lock 2. Spreader frame 1 is forklift 4
The lift bracket 6 is horizontally swingably attached to a lift bracket 6 that can be raised and lowered along a mast 5. That is, as shown in FIGS. 2 and 3, a support arm 7 is provided at the center of the front surface of the lift bracket 6, projecting horizontally in the straight direction.
A vertical center bin 8 provided at the tip of this support arm 7
A longitudinally long long hole 9 provided in the center of the spreader frame 1 is loosely fitted into the spreader frame 1.

Further, the left and right hydraulic cylinders 10 for horizontally swinging the spreader frame 1 are arranged symmetrically across the center bin 8, and their head side ends are pivotally connected to the lift bracket 6 by a bin 13, and the piston rod 11 is pivotally attached to the spreader frame 1 by a pin 14.

Next, the hydraulic circuit of the hydraulic cylinder 10 will be explained based on FIG. 1. The rod-side oil chambers of the left and right hydraulic cylinders 10 are connected to a manually operated control valve 15 that can be operated above the driver's seat through independent hydraulic oil supply pipes 16, and are supplied with hydraulic oil from a hydraulic pump 23. It can be operated individually only in the contraction direction. On the other hand, the head side oil chamber of the hydraulic cylinder 10 is connected to the hydraulic oil supply pipe 16 by a pipe 17.
is provided with a check valve 18 for blocking the flow to the head side, and the head side oil chamber is further connected to a return line 20 via a relief valve 19, and a replenishment chamber equipped with a check valve 21 is provided. It is connected to a tank 24 via a conduit 22.

Further, the piston 10 of the hydraulic cylinder 9 is provided with a passage 25 that communicates both chambers on the rond side and the head side.
This passage 25 is provided with a check valve 26 that prevents flow from the head side oil chamber to the rod side oil chamber. Further, a spring 27 is housed in the head-side oil chamber to always bias the hydraulic cylinder 10 in the extension direction, so that the hydraulic cylinder 10 is normally held at the end of its stroke in the extension direction. When the left and right hydraulic cylinders 10 are in the maximum extension state, the center pin 8 of the support arm 6 is positioned approximately at the center of the elongated hole 9 of the spreader frame 1, as shown in FIGS. 2 and 3. .

Further, as shown in FIG. 2, limit switches 28 for safety are provided on the left and right front surfaces of the lift bracket 6, respectively.
29 are provided, and these switches 28 and 29 are turned on by contacting the spreader frame 1 before the hydraulic cylinder 10 reaches the stroke end in the contraction direction.
Then, as shown in FIG. 4, a buzzer 30 or the like is activated to issue a warning to the operator.

This embodiment is constructed as described above, and its operation will be explained below.

Normally, the control valve 15 is held at a neutral position as shown in FIG. 1, and therefore the left and right hydraulic cylinders 10 are held at their maximum extension by the springs 27. In this state, when the spreader is moved toward the container C, that is, when the vehicle is moved forward, if the spreader frame 1 is tilted to the right with respect to the container C as shown in FIG. stopper 3
comes into contact with the left rear end surface of container C. Then, if the spreader is further advanced in this contact state,
A force in the contraction direction acts on the left hydraulic cylinder 10, which is the side that contacts the stopper.

That is, the piston rod 1 of the left hydraulic cylinder 10
1 has a bin 14 which is a connection point with the spreader frame 1.
Since the illustrated force P acts through the piston 12, the piston 12 is pushed against the spring 27 by this force.

At this time, the oil in the head side oil chamber flows from the check valve 18 to the pipe line 17.
Excess oil enters the rod side oil chamber through the relief valve 19 and returns to the tank 24.

On the other hand, the right side of the spreader frame 1 continues to move forward, so the spreader frame 1 swings horizontally using the left stopper 3 that is in contact with the container C as a fulcrum, and eventually the right side stopper 3 moves forward. Spreader frame 1 for C that contacts and covers the right rear end surface of container C
A parallel state is obtained. In other words, the hanging hole C of the container C
The twist lock 2 of the spreader frame 1 relative to the spreader frame 1 is automatically aligned at least in the longitudinal direction. In addition, at this time, the center bin 8 is connected to the left hydraulic cylinder 1.
It moves forward in the elongated hole 8 in response to the contraction operation of 0.

In addition, at the time of the above-mentioned positioning, before the parallel state of the container C and the spreader frame 1 is obtained,
When the hydraulic cylinder 10 during the contraction operation approaches the stroke end, the left limit switch 28 comes into contact with the container C and is turned on, so that the -buzzer 30 etc. are activated to notify the operator. Therefore, in this case, by redoing the alignment work, stopper 3 and container C
Damage to these parts due to excessive force acting on the contact parts can be prevented.

After the alignment is completed, the container C is lifted by sequentially inserting and engaging the twist lock 2 into the lifting hole C1 of the container C and raising the spreader. Since the force P acting on the hydraulic cylinder 10 is eliminated, the piston rod 11 of the hydraulic cylinder 10 is moved by the spring 27.
It is ejected by the restoring force and returned to the maximum extension position as the initial position. At this time, the oil in the rod side oil chamber pushes open the check valve 26 of the passage 25 and flows into the head side oil chamber.
Also, the shortage is covered by the check valve 21 of the replenishment line 22 from the tank 24.
It flows into the head side oil chamber through the.

Also, if you need to correct the orientation of container C when unloading it after transport, for example if you want to tilt it to the right,
The control valve 15 is switched to connect the hydraulic pump 23 to the right hydraulic cylinder 10. At this time, hydraulic oil is supplied to the rod side oil chamber of the right hydraulic cylinder 10, and as long as this pressure is greater than the set pressure of the relief valve 19, the piston 12 is pushed toward the head side against the spring 27. That is, since the oil in the head side oil chamber escapes to the tank 24 via the relief valve 19, the piston 1
2 is moved to the head side oil chamber, and at this time, the check valve 26 of the passage 25 receives the pressure of the head side oil chamber on the outlet (back side) side and is maintained in a closed state. The right hydraulic cylinder 10 is thus retracted, the spreader frame 1 is tilted to the right, and the container C is corrected to the desired orientation.

After the correction, return the control valve 15 to the neutral position, lower the container C, and tighten the twist lock 2.
is removed from the hanging hole C1, the right hydraulic cylinder 10 returns to its maximum extension state due to the return force of the spring 27 in the same way as when returning after alignment described above, and the spreader frame 1 returns to its initial position parallel to the lift bracket 6. to return to.

In this embodiment, the piston 12 is provided with a passage 25 with a check valve 26, but it is also possible to replace this with an orifice. Further, the spring 27 is not limited to a built-in type in the cylinder, but may also be placed externally.

(Effects of the Invention) As detailed above, according to the present invention, it is possible to automatically correct the parallelism of the spreader frame to the container during container lifting work, that is, automatically adjust the position of the twist lock with respect to the lifting hole. This improves work efficiency compared to the conventional method of pulp manipulation that relies on the operator's intuition, and is greatly useful in improving work efficiency and reducing operator fatigue. Further, the external force acting on the stopper during positioning is equivalent to the force that causes the hydraulic cylinder to contract against the spring, and there is no risk of damage to the stopper or the container. Note that adjustment of the orientation of the container when unloading the container can be carried out without any hindrance by operating the control valve in the same manner as in the past.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic cylinder for swinging the spreader foot and its hydraulic circuit diagram showing an embodiment of the present invention, Fig. 2 is a plan view of the spreader, Fig. 3 is a side sectional view, and Fig. 4 is an alarm circuit diagram. FIG. 5 is a schematic side view of a forklift equipped with a spreader, and FIG. 6 is an explanatory diagram showing a conventional example. 1... Spreader frame 3... Stopper 6.
...Lift bracket 10...Hydraulic cylinder 12
... Piston 15 ... Control valve 1
6... Hydraulic oil supply pipe line 17... Pipe line 18.2
1.26...Check valve 25...Passage 27...Spring Applicant: Toyota Industries Corporation ll Ltd. Agent
Patent attorney Hidehiko Okada (3 others) Figure 4 Figure 5

Claims (1)

[Claims] The spreader frame is attached to the lift bracket so that it can swing horizontally, and on both sides of the attachment part there are stoppers for positioning the spreader with respect to the container and hydraulic cylinders for swinging the spreader frame. In a spreader in which the spreader frame is horizontally swung by switching a valve and operating a hydraulic cylinder,
The hydraulic oil supply pipe for always urging both hydraulic cylinders in the extension direction by a spring and for supplying hydraulic oil from the hydraulic pump to the rod side oil chamber of the hydraulic cylinder has one end connected to the head side oil chamber. A conduit with a check valve for preventing oil from flowing into the head side oil chamber is connected to the piston, and a check valve is connected to the piston of the hydraulic cylinder to prevent oil from flowing from the head side oil chamber to the rod side oil chamber. Spreader alignment device with a passage or orifice with a stop valve.