JPH03138299A - Container spreader device - Google Patents

Abstract

PURPOSE:To guarantee the correct position adjustment and horizontality of a spreader rail by providing a lock pin to be removably engaged with a positioning hole, bored at each leg body, piercing the cylinder wall of a vertical cylinder part, and a spring for energizing the lock pin always in the advancing direction, as well as a control mechanism for timing the lock pin. CONSTITUTION:In the case of changing a spreader rail 12 in its initial position 8ft into an adjusted position 9ft, a corresponding operating switch S3 is turned on first. Then the reset input end R, being L so far, of a flip-flop FF3 becomes H, and a solenoid SOL is turned on, so that a lock pin 30 in colliding contact with the outer face of a leg body 24 by the energizing force of a spring 32 is forced to recede. When proximity sensors LS1, LS2 then detect a region A3 by the expansion of a hydraulic cylinder 25 based on lever operation, a lamp L3 is lighted up, as well as a logic gate G3 becomes H simultaneously, so that the FF3 is reset, and the tip of a pin 30 is inserted into a positioning hole 33b corresponding to the adjusted position 9ft by the energizing force of the spring 32.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a container spreader device mounted on a forklift, and more specifically, it is constructed so that the position of a spreader rail can be adjusted according to the height of a container being handled. This invention relates to a container spreader device.

[Prior Art] The conventional container spreader device shown in FIG. 5 has a spreader frame 10 that is attached to the platform of a forklift and moves up and down, as seen in the device disclosed in Japanese Utility Model Application No. 63-4984, for example. The spreader rail 12, which is installed horizontally on the upper part of the spreader frame 10 and has a twist lock mechanism (only the twist lock pin 11 is shown in the figure) that engages with the container, is connected to a pair that hangs downward via a joint 13. The legs 14 of the spreader frame 1
By operating a pair of hydraulic cylinders 16 for adjustment, which are fitted into the upright cylindrical part 15 that also serves as the vertical frame of 0, and are interposed between the outer wall surface of the upright cylindrical part 15 and the spreader rail 12,
It is configured to be adjustable in the vertical direction.

In other words, a large rotational moment acts on the container suspended at two points by the twist lock pins 11 with the same suspension points as the pivot, and this is because the reinforcing portion provided at the lower end of the front side of the container is attached to the spreader frame 10. It is accepted by colliding with a pad 17 installed on the front side of the horizontal frame, but containers are generally used in four height levels from 8ft to 0.5ft, and when handling any container, Also the reinforcement part of the above container and pad 1
This is because in order to accurately align the spreader rail 12 with the spreader rail 12, it is necessary to adjust the position of the spreader rail 12.

[Problems to be Solved by the Invention] In the conventional device described above, the pair of adjusting hydraulic cylinders 1
In order to synchronize the spreader rail 12, a diverter valve is placed in the circuit to supply oil to the cylinder 16, but even a slight deviation in accuracy of the diverter valve tends to cause the spreader rail 12 to tilt. This is also one of the factors that makes it difficult to carry out heavy lifting operations. Furthermore, since the method of adjusting the position of the spreader rail 12 according to the type of container is based solely on the visual confirmation of the indicator 18 graduated in four stages (Fig. 5), it is natural that adjustment errors may occur. The drawback was that it could not be completely erased.

The technical problem to be solved by the present invention is to accurately adjust the position of the spreader rail and to ensure high levelness at each adjustment position.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention includes a spreader frame that is attached to the platform of a forklift and moves up and down, and a pair of hanging legs that are guided by an upright cylindrical portion of the spreader frame.
In a container spreader device comprising a spreader rail that can be adjusted in the vertical direction by being driven by a pair of hydraulic cylinders, and a twist lock mechanism built into the spreader rail, A locking pin that removably engages with a positioning hole drilled in each leg, a spring that always biases the locking pin in a forward direction, and a spring that resists the biasing force of the spring. It adopts a new configuration with a control mechanism that allows the robot to retract at the appropriate time.

In a preferred embodiment of the present invention, the control mechanism includes an initial position display means of the spreader rail, a changed position command means, and a command signal of the changed position command means and an operation of a hydraulic cylinder to determine the required position of the locking pin. and a traction means for forced retreat during the hours of

[Function] As mentioned above, four levels of container height are commonly used, and for containers of maximum and minimum height (9, 5 and 8 ft), each adjustment of the spreader rail at the end of the stroke of the hydraulic cylinder is required. The position is set correspondingly, and containers of intermediate height (9 and 8.5 ft) similarly have their spreader rail adjustment positions established through the engagement of the locking pins.

That is, the traction means is operated in response to a change position command via the control mechanism, and just before reaching the change position, the traction operation of the traction means is canceled and the biasing force of the spring is applied to the locking pin. Therefore, even if there is a slight deviation in the synchronized movement of the paired hydraulic cylinders due to the accuracy of the flow divider valves, the spreader rails can be adjusted accurately by the engagement of the locking pins of the pairs or the end of stroke of the hydraulic cylinders. Position adjustment and high levelness at each adjustment position are guaranteed.

[Example] Hereinafter, the present invention will be explained in detail based on the drawings.

Components that are the same as those in the conventional device will be described using the same reference numerals as those in FIG.

In FIGS. 1 to 4, a spreader frame 20 that is attached to a loading platform 2 of a forklift 1 and moves up and down is strongly formed from an upright cylindrical portion 21 that also serves as left and right vertical frames, and upper and lower horizontal frames 22, and is made up of a container C. Twist lock mechanism that engages with (
The spreader rail 12, which is installed horizontally on the upper part of the spreader frame 20 and has a twist lock bin 11 (only the twist lock bin 11 is shown in FIG. A pair of hydraulic cylinders 25 inserted into the cylindrical portion 21 and interposed between the support portion extending from the outer wall surface of the upright cylindrical portion 21 and the spreader frame 12.
However, the spray ladder rail 12 is configured to be adjustable in the vertical direction by synchronized operation by oil supply via a not-shown diverter valve.

In other words, a large rotational moment acts on the container C, which is suspended at two points by the twist lock pin 11, with the same suspension point as the pivot, and this is because the reinforced part provided at the lower end of the front side of the container C is connected to the spreader frame. Container C is generally accepted by colliding with the pad 17 installed on the entire surface of the lower horizontal frame of container C (see Fig. 5).
ft to Q, four height levels in 5 ft increments are commonly used, and in order to accurately align the reinforced part of the container C and the pad 17 when handling any container C, the spreader rail is The vertical position of 12 is adjusted. In this case, the maximum and minimum heights (9, 5 and 8
ft> for container C is set so that both stroke ends of the hydraulic cylinder 25 are adapted to this as is, and the adjustment position for containers C of intermediate height (9 and 8.5 ft> is described below. This is determined by the engagement between the locking pin and the positioning hole.

As clearly shown in FIG. 2, a bottomed cylinder 31 that supports a locking pin 30 is attached to the cylinder wall of the left upright cylinder part 21, and a spring 32 built in the bottomed cylinder 31 is activated. The locking pin 30, which is always urged in the direction of movement, is attached to the upright cylinder portion 2.
It is constructed so that it can be inserted into and removed from two positioning holes 33a and 33b formed in the leg body 24 by penetrating the cylindrical wall of 1.

The control mechanism moves the locking pin 30 against the biasing force of the spring 32 when adjusting the spreader rail 12 from the initial position (current position) to the changed position as the height of the handling container C changes. For example, an initial position display means including an initial position display lamp of the spreader rail 12, a change position command means equipped with an operation switch, etc., a command signal of the change position command means, and an expansion/contraction of the hydraulic cylinder 25. It is composed of an electric control system whose main element is a traction means such as a solenoid that pulls and retreats the locking pin 30 for a required period of time based on the operation.

Next, the above control mechanism will be explained in detail.

The control mechanism includes a proximity sensor LS1.132 that detects the vertical position of the spreader rail 12, and a control circuit section 40 that processes its output signal, and includes a magnetically sensitive proximity sensor L.
S1 and LS2 are juxtaposed on the outer peripheral surface of the hydraulic cylinder 25, and a detection object 50 made of a steel plate is suspended from the lower end surface of the spreader rail 12, facing the proximity sensors LSI and LS2. Two rows of grooves 52 and 53 are carved in the vertical direction on the detection surface 51 of the detection object 50, which faces the proximity sensor LSI and LS2 with a small interval, and the proximity sensor LSI, LS2 individually detects whether these grooves 52, 53 cooperating with the spread barrel 12 are close together.

To explain further, the area facing the proximity sensors LS1 and LS2 of the detection surface 51 that moves up and down has an area of 0.5f in the vertical direction.
The area is divided into four areas A1 to A4 for every t. The grooves 52 facing the proximity sensor LS1 are in areas A1 and A.
The grooves 53 facing the proximity sensor LS2 are bored in the areas A1 and A3. Each detected position (adjustment position @) of 8 to 9.5 ft is set at the midpoint of the areas A1 to A4, respectively. Therefore, in area A1, both proximity sensors LS1 and LS2 are on, in area A2, only proximity sensor LS1 is on, in area A3, only proximity sensor LS2 is on, and in area A4, both proximity sensors LS1 and LS2 are off.

Next, to explain the control circuit section 40 according to FIG. 4, the output terminal a of the proximity sensor LSI is grounded by a resistor R1, and the output terminal of the proximity sensor LS2 is grounded by a resistor R2.
Output terminals a and b are individually input to logic gates 01 to G4. The output terminal of logic gates 01 to G4 is an indicator lamp L1
~Activate L4 and flip-flop FF1
~ are individually input to the reset input terminal R of FF4. Each set input terminal S of flip-flops FF1 to FF4 is
They are individually connected to the high-level power supply terminal VCC by the first to fourth operation switches 81 to S4, and further individually grounded via the discharge resistor R3. Flip 70 TsubuFFI~FF4
are of the reset priority type, and their Q outputs are connected to the base of the driver transistor Tr whose emitter is grounded via the OR circuit G5 and the current limiting resistor R4.

The collector of the driver transistor Tr is the horizontal frame 22.
The solenoid SQL placed above is driven to pull the extended rear end of the locking pin 30 that has entered the solenoid SQL, and the locking pin 30 is forcibly retracted. Note that the first operation switch S1 is a switch that commands a change to the 8ft adjustment position located in area A1, and similarly the second operation switch
-Fourth operation switches 82 to S4 are switches for instructing changes to each adjustment position of 8.5 to 9.5 ft.

Hereinafter, the position adjustment operation of the spreader frame 12 by the above-mentioned control mechanism will be explained. Due to the adjustment operation of the spreader rail 12, the potentials of the output terminals a and b of the proximity sensors LS1 and LS2 fluctuate, and each logic gate G1 changes accordingly. Since the output potential of ~G4 fluctuates, the respective lamps 11-L4 are lit in areas A1-A4 to display the current position.

Now, if the initial position of the spreader rail 12 is 8ft and you want to change it to the adjusted position of 9ft with the next handling container C, first, the corresponding third
The operation switch S3 is made conductive. As a result, the flip-flop FF whose reset input terminal R is at a low level
3 becomes high level, the solenoid SQL is turned on, and the locking pin 30, which had been in contact with the outer surface of the leg body 24 until then, is forcibly retracted by the biasing force of the spring 32.

Then, when the proximity sensor LSI, LS2 detects the area A3 due to the extension of the hydraulic cylinder 25 based on the lever operation,
At the same time that the lamp L3 lights up, the logic gate G3 becomes high level, the flip-flop FF3 is reset, the solenoid SQL is turned off, and the tip of the locking pin 30 collides with the outer surface of the leg 24 due to the biasing force of the spring 32. ,
Positioning hole 33b corresponding to the adjustment position of 9ft
is inserted into the Of course, even if there is a slight deviation in the synchronized operation of the paired hydraulic cylinders 25 due to the accuracy of the flow dividing valve, the locking pins 3 that are connected to the positioning holes 33b of the legs 24 one after the other
0 insertion, the spreader rail 12 is accurately aligned. Note that the pressure increase in the oil supply circuit to the hydraulic cylinder 25 based on the engagement of the locking pin 30 is controlled by a relief valve (not shown), so the spreader rail 12
The operating lever is returned to neutral after the engine stops.

Next, when the current position is 8 ft and the adjustment position is to be changed to 9.5 ft, the corresponding fourth operation switch circuit S4 is made conductive. As a result, the flip-flop FF4 whose reset input terminal R is at a low level
becomes high level, the solenoid SQL is turned on, and the locking pin 30 is similarly forcibly retracted. When the proximity sensors LS1 and LS2 detect area A4 due to the extension of the hydraulic cylinder 25 based on the lever operation, the lamp L
4 lights up, the logic gate G4 becomes high level, the flip-flop FF4 is reset, the solenoid SQL is turned off, and the tip of the locking pin 30 collides with the outer surface of the leg 24 due to the biasing force of the spring 32. The spreader rail 12 is then adjusted to the desired 9° 5 ft position by the extended end of the hydraulic cylinder 25.

That is, in this control circuit section 40, when a change position is commanded, the solenoid SQL is turned on, and the proximity sensor L is turned on.
Since S1 and LS2 are automatically turned off when they reach the required change area within the area A1-A4, there is no error that the locking pin 30 is inserted into unnecessary positioning holes 33a and 33b during adjustment movement.

Note that the following configuration can also be adopted as a modification of the above control device.

That is, magnetic patterns are recorded at regular intervals on the detection surface 51 of the detection object 50, and a reference position is recorded at the center. A magnetic encoder is provided in place of the proximity sensor LS1, and the magnetic pattern is read by this magnetic encoder. The read magnetic patterns are sent to the microcomputer, which counts the magnetic patterns and calculates the absolute distance from the reference position. After that, when a command is issued to change to one of the above positions 8 to 9.5 ft, the hydraulic cylinder 25 and solenoid SQL are controlled based on the relationship between the current position and the command position, and the lock is stopped close to the changed position. The spreader rail 12 can be adjusted while pulling the pin 30.

[Effects of the Invention] As described above in detail, the present invention ensures the adjustment position of the spreader rail according to the type of container by engaging the locking pins of the left and right pairs at the stroke ends of the hydraulic cylinders. Therefore, regardless of the accuracy of the flow divider valve, the container and pad can always be stably aligned and collided based on accurate position adjustment, and the adjustment posture of the spreader rail is always high in any case. Since levelness is guaranteed, the container can be lifted quickly and smoothly.

[Brief explanation of the drawing]

Fig. 1 is a side view of a forklift truck equipped with a container spreader device according to the present invention, Fig. 2 is a partially sectional front view showing main parts of the container spreader device, and Fig. 3 is a line taken along the line ■-■ in Fig. 2. 4 is a circuit diagram showing a control circuit section of the control mechanism, and FIG. 5 is a front view showing a conventional container spreader device. 12... Spreader rail 20... Spreader frame 21... Upright cylinder 24... Leg body 25... Hydraulic cylinder 30... Locking pins 33a, 33b... Positioning hole 40... Control circuit section

Claims (1)

[Claims] (1) A spreader frame that is attached to the platform of a forklift and moves up and down, and a pair of hanging legs that are guided by the upright cylindrical part of the spreader frame, and a spreader that can be adjusted vertically by being driven by a pair of hydraulic cylinders. In a container spreader device comprising a rail and a twist-lock mechanism built into the spreader rail, the container spreader device is configured to penetrate a cylindrical wall of the upright cylindrical portion and engage with positioning holes drilled in each of the leg bodies in a removable manner. A container spreader comprising a locking pin that fits together, a spring that always biases the locking pin in a forward direction, and a control mechanism that retracts the locking pin at a timely manner against the biasing force of the spring. Device.