JP3675005B2 - Container spreader strut coupling device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a container spreader that is mounted on a forklift and is used for container handling, and more particularly to a wing type container spreader in which twist lock columns are erected at the tips of left and right reach rails.
[0002]
[Prior art]
As shown in the schematic front view of FIG. 7, the wing-type container spreader includes a rail holder 32 formed of a cylindrical body as a spreader main body that is mounted so as to be movable up and down along the mast 31 of the forklift. The left and right reach rails 33 are attached to be extendable, and twist lock columns 34 are erected at the ends of the reach rails 33. The twist lock column 34 includes a rectangular tube-shaped lower column 35 fixed to the end of the reach rail 33 and a rectangular tube-shaped upper column 36 fitted to the outside of the lower column 35 so as to be movable up and down. A twist lock device 37 is provided at the upper end of the upper column 36.
[0003]
As shown in FIG. 8, the twist lock device 37 includes a twist lock box 38 fixed to the upper column 36 and a twist lock pin 39 provided on the front lower surface of the twist lock box 38 so as to be horizontally rotatable in a suspended state. And a drive device (not shown) installed in a twist box 38 for driving the twist lock pin 39. The bottom surface of the twist lock box 38 is received by the upper end portion of the lower column 35, and the upper column 36 is held at the lower limit position.
[0004]
In the twist lock column 34, a connecting rod 40 and a compression spring 41 as a column connecting device for connecting the upper and lower columns 35 and 36 are accommodated vertically. The connecting rod 40 has an upper end fixed to the bottom plate of the twist lock box 38 by a nut 42 and supported in a suspended manner, and a spring receiver 43 provided at the lower end thereof and a substantially central portion in the lower support 35. A compression spring 41 is interposed between the spring receiver 44 and the spring receiver 44. Further, a cylindrical stopper 45 is fitted on the lower side of the connecting rod 40 and is placed on the spring receiver 43. The stopper 45 abuts on the spring receiver 44 on the lower column 35 side. The upward movement of the upper column 36 is restricted.
[0005]
That is, in the conventional wing-type container spreader, the left and right twist lock struts 34 are disposed within the stroke S until the stopper 45 comes into contact with the spring receiver 44 of the lower strut 35 when an upward external force is applied to the upper strut 36. Thus, the upper support column 36 moves relative to the lower support column 35 against the compression spring 41. Accordingly, when the container is unloaded, as shown in FIG. 7, when the container spreader is lowered on the upper surface of the container C placed in an inclined posture or when the container C is lowered on the inclined surface, the left and right twist lock pins The position 38 can correspond to the inclination of the container C.
[0006]
[Problems to be solved by the invention]
By the way, in the case of the strut connecting structure having the above-described structure, when the connecting rod 40 is cut by an excessive external force exceeding expectation or due to fatigue failure or the like, the compression spring 41 which is a considerable heavy load is removed from the twist lock strut 34. It is desirable not to drop off. Therefore, conventionally, as shown in FIG. 8, a flange 35 a having an overhang is provided on the lower inner surface of the lower column 35, and a lid plate 46 is attached to this with a bolt 47 to close the lower portion of the lower column 35. Although the spring 41 is prevented from accidentally falling off, in such a configuration in which another part not directly related to the column connection is additionally set to prevent the dropping, the number of parts is increased and the assembling man-hour is increased. There is a problem that the cost increases due to the increase.
[0007]
The present invention has been made in view of the above-described problems, and the object of the present invention is to prevent the compression spring from falling off by a member directly involved in the column connection when the connection rod is unexpectedly cut. An object of the present invention is to provide a column connecting device for a container spreader.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention takes the following measures. That is, the invention according to claim 1 is a cylindrical lower support column fixed upright at the end of the rail, and is fitted to the lower support column so as to be movable up and down, and is supported from the lower side by the lower support column. A container spreader strut connecting device in which a twist lock strut is composed of an upper strut held by the upper strut, wherein the upper strut is fitted into the lower strut, and the upper strut is coupled to the upper strut The connecting rod and the compression spring are arranged vertically, and the connecting rod is fixed to the lower support with the lower end protruding from the lower end of the upper support, and the compression spring is connected to the connecting rod. It is characterized by being interposed between a provided spring receiver and a spring receiver provided on the inner surface of the upper column below the spring receiver.
[0009]
According to the invention of claim 1 configured as described above, the compression spring is received from the lower side by the spring support of the upper support inserted into the lower support, so that even if the connecting rod is cut, the compression spring is supported by the support. It will not fall out of the inside.
[0010]
According to a second aspect of the present invention, in the container spreader column connecting device according to the first aspect, a screw portion is provided at a lower end portion of the connecting rod, and the screw portion is screwed to a connecting plate provided on the lower column. It is characterized by being. Therefore, according to the invention of claim 2, even when the connecting rod is cut, the broken end of the connecting rod remains on the connecting plate and does not fall off.
[0011]
According to a third aspect of the present invention, in the container spreader strut coupling device according to the first aspect, a position where the upper strut protrudes a predetermined height upward from the lower strut is set as a lower movement lower limit position. Is characterized in that it is set to be slightly larger than the amount of droop of the twist lock pin suspended from the lower surface of the twist lock box fixed to the upper end of the upper support column.
[0012]
Therefore, according to the third aspect of the present invention, when the twist lock pin is visually recognized from the driver's seat, the compression is performed when the thickness of the upper column is set so that the twist lock pin does not enter the blind spot of the upper column. The accommodation space in the radial direction of the spring is increased as compared with the conventional case. That is, when the thickness of the upper column is set to be the same as the conventional one, the compression spring is accommodated in the upper column. According to the invention of claim 3, the lower column is fitted in the upper column and the compression is compressed in the lower column. Compared to the conventional case in which the spring is stored, the storage space for the compression spring is substantially increased, so that the spring diameter of the compression spring can be set larger.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. This embodiment is intended for a wing type container spreader, and its basic configuration is the same as the conventional one. That is, as shown in the front view of FIG. 2 (represented only on the right side), the wing-type container spreader includes a rail holder 1 as a spreader body that is mounted so as to be movable up and down along the mast of a forklift (not shown), 1, a left and right reach rail 2 (only one side is shown in the figure), a twist lock column 3 erected at the tip of both reach rails 2, and an upper end portion of both twist lock columns 3. And a twist lock device 6.
[0014]
The twist lock device 6 includes a twist lock box 7 fixed to the uppermost end of the twist lock column 3, a twist lock pin 8 provided on the front lower surface of the twist lock box 7 so as to be horizontally rotatable in a suspended state, A drive device (not shown) and the like installed in a twist box 7 for driving the twist lock pin 8 are configured. Further, as shown in FIG. 1, the twist lock support 3 is fitted into a hollow lower support 4 having a rectangular cross section fixed to the tip of the reach rail 2 and standing upright, and the lower support 4 can be moved up and down. It is comprised from the hollow upper support | pillar 5 which makes a cross-sectional rectangle.
[0015]
A ring-shaped stopper 9 is fixed to the upper part of the outer periphery of the upper column 5 by welding, and the upper column 5 is held at the lower position by supporting the stopper 9 at the upper end of the lower column 4. ing. Note that the upper support column 5 is defined as a lower movement lower limit position where the upper support column 5 protrudes from the upper end of the lower support column 4, and the protruding height is less than the amount of droop of the twist lock pin 8 as shown in the figure. Set slightly larger.
[0016]
Next, a column connecting device for connecting the upper and lower columns 4 and 5 will be described with reference to FIG. In order to elastically connect both struts 4, 5, the strut coupling device has a circular connecting rod 10 and a compression spring 11 arranged vertically in the upper strut 5, and an upward movement range of the upper strut 5. A cylindrical stopper member 12 to be regulated is configured as a main member. The stopper member 12 is fixed to the connecting rod 10 by welding in a state of being fitted approximately in the middle of the connecting rod 10 in the axial direction, and the lower end of the stopper member 12 abuts against the bottom plate 13 of the upper column 5 so that the upper column is supported. The upward movement of 5 is regulated.
[0017]
Further, the compression spring 11 is disposed so as to be fitted to the outer periphery of the stopper member 12, and is formed at the lower end portion of the upper column 5 and the overhanging spring receiver 14 formed integrally with the upper end portion of the stopper member 12. It is received by the bottom plate 13. Accordingly, the bottom plate 13 constitutes a spring receiver. Further, a screw portion 10a is provided at the lower end portion of the connecting rod 10, and this screw portion 10a extends through the center hole 13a of the bottom plate 13 of the upper column 5 to the lower column 4 side. After being penetrated through a bottom plate 15 as a connecting plate formed at the lower part of the inner surface, the nut 16 is fastened.
[0018]
The above-described members are assembled by inserting them downward from the working holes 7b formed in the bottom plate 7a of the twist lock box 7 so that the compression spring 11 is provided with the stopper member 12 in consideration of the assembling property at that time. It is desirable to fix to the spring receiver 14 by welding or a U-bolt, for example.
[0019]
According to the container spreader according to the present embodiment configured as described above, the upper and lower support columns 4 and 5 can move up and down within the range of the stroke S regulated by the contact between the stopper member 12 and the bottom plate 13. Permissible. Therefore, the positions of the left and right twist lock pins 8 can be made to correspond to the inclination of the container C as in the conventional case shown in FIG.
[0020]
In the present embodiment, the upper support column 5 is inserted into the lower support column 4, so that the compression spring 11 can be received by the bottom plate 13 formed on the upper support column 5. Therefore, even when the connecting rod 10 is cut by an excessive external force exceeding expectation or due to fatigue failure, the spring receiver 14 is applied to the compression spring 11 received by the bottom plate 13 of the upper column 5 and the compression spring 11. It is possible to prevent the stopper member 12 that is in contact from falling off the support column.
[0021]
That is, according to the present embodiment, the members directly involved in the column connection can prevent the compression spring 11 and the stopper member 12 from falling off, so that the cover plate 46 as a separate part is retrofitted to the lower column 33 as in the prior art. This makes it possible to save labor and reduce the number of parts and assembly man-hours.
[0022]
By the way, as shown in FIG. 3, in order to visually recognize the twist lock pin 8 that hangs down on the front lower portion of the twist lock box 7 on the driver's seat, the twist lock pin 8 is blinded (indicated by hatching). ) Must be set not to enter. For this purpose, it is necessary to secure a certain distance L1, L2 between the center of the twist lock pin 8 and the front surface of the column and between the center of the twist lock pin 8 and the side surface of the column. Unless the design is changed, the upper support column 5 is restricted by the thickness setting.
[0023]
In the present embodiment, however, the upper support column 5 is fitted into the lower support column 4 with the position where the upper support column 5 protrudes slightly larger than the hanging amount of the twist lock pin 8 from the upper end of the lower support column 4 as the lower movement lower limit position. Since the compression spring 11 is arranged in the upper column 5, when the thickness of the upper column 5 is the same as the conventional one, the lower column 35 is inserted into the conventional upper column 36 shown in FIG. Compared to the configuration in which the compression spring 41 is disposed in the lower support column 35, the accommodation space in the radial direction of the compression spring 11 is increased compared to the conventional case.
[0024]
This makes it possible to set a constant spring constant of the compression spring 11 disposed in the upper support column 5 and to set the spring diameter to be large, thereby reducing the internal stress of the compression spring 11 and its durability. Can be improved.
[0025]
In the conventional structure shown in FIG. 8, it is difficult to set the compression spring 41 as described above. Therefore, when the stress of the compression spring 41 is not sufficient, the twist lock strut 34 in addition to the compression spring 41 is used. On the outside, there may be a case where a tension spring 48 is added between the upper and lower support columns 35 and 36 as shown in the phantom line in the figure, but such a countermeasure has a problem that two kinds of springs are required and the cost is high. According to the present embodiment, such a problem is solved.
[0026]
Next, another embodiment of the present invention will be described. The embodiment shown in FIG. 4 is an example of a change in the connecting structure of the connecting rod 10 to the lower support column 4. The nut 16 is fixed to the bottom plate 15 of the lower support column 4 by welding (or a screw hole is formed in the bottom plate 15). It is fixed by screwing the threaded portion 10a of the connecting rod 10 into it. With this configuration, the connecting rod 10 remains in a state of being screwed to the nut 16 regardless of where the connecting rod 10 is cut. That is, it is possible to prevent the broken end of the connecting rod 10 from falling from the twist lock support 3.
[0027]
Further, the embodiment shown in FIG. 5 is a modification of the connection structure of the connecting rod 10 to the lower support column 4. A flange portion 17 is set at the lower end of the connecting rod 10, and the flange portion 17 is connected to the lower support column 4. The bottom plate 15 is fixed by tightening the nut 16 from the lower surface side in contact with the upper surface of the bottom plate 15. According to such a configuration, as long as the cutting of the connecting rod 10 occurs above the flange portion 17, it is possible to avoid the broken end from dropping from the twist lock support 3.
[0028]
Further, the embodiment shown in FIG. 6 is a modified example related to the stopper for restricting the downward movement position of the upper column 5, and is configured to weld the ring-shaped stopper 9 to the outer periphery of the upper column 5 described in the above-described embodiment. Instead, the lower column of the upper column 5 is extended downward and supported on the upper surface of the bottom plate 15 of the lower column 4, that is, the bottom plate 15 is used as a stopper. According to such a configuration, since the bottom plate 15 serves as both the connecting plate of the connecting rod 10 and the stopper of the upper column 5, it is possible to save time and labor for welding the stopper 9 to the upper column 5.
[0029]
【The invention's effect】
As described above in detail, according to the first aspect of the present invention, when the connecting rod for connecting the upper and lower support columns incorporated in the twist lock support column is unexpectedly cut, the heavy compression spring falls from the support support column. Since it is a structure which can prevent a fall of a compression spring especially by the member which is directly related to support | pillar connection, it is not necessary to set another part for the fall prevention like the past.
[0030]
Further, according to the invention of claim 2, it is possible to prevent the broken end from dropping when the connecting rod is cut. Furthermore, according to the invention of claim 3, it becomes possible to set the spring diameter of the compression spring disposed in the support column to be large, and the durability of the spring can be improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a column connecting device for a container spreader according to an embodiment of the present invention.
FIG. 2 is a front view showing only the right side of the container spreader.
FIG. 3 is a schematic plan view of a twist lock column.
FIG. 4 is a cross-sectional view showing another embodiment relating to a connecting structure of a connecting rod and a lower support column.
FIG. 5 is a cross-sectional view showing still another embodiment relating to a connecting structure of a connecting rod and a lower support column.
FIG. 6 is a cross-sectional view showing another embodiment related to a stopper for restricting the downward movement position of the upper column.
FIG. 7 is a simplified front view of a conventional wing type container spreader.
FIG. 8 is a longitudinal sectional view showing a conventional strut coupling device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rail holder 2 ... Reach rail 3 ... Twist lock support | pillar 4 ... Lower support | pillar 5 ... Upper support | pillar 9 ... Stopper 10 ... Connecting rod 11 ... Compression spring 12 ... Stopper member 13 ... Bottom plate 14 ... Spring receiver 15 ... Bottom plate

Claims (3)

Twisted from a cylindrical lower column that is fixed upright and fixed to the rail tip, and an upper column that is fitted to the lower column so as to be movable up and down and is supported from the lower side by the lower column and held at the lower position. A container spreader strut connecting device in which a lock strut is configured,
The upper strut is fitted into the lower strut, and a connecting rod and a compression spring for connecting the upper and lower struts are vertically disposed in the upper strut, and the lower end of the connecting rod is the lower end of the connecting rod. The compression spring is fixed between the spring support provided on the connecting rod and the spring support provided on the inner surface of the upper support below the spring support in a state protruding from the lower end of the upper support. A column connecting device for an intervening container spreader. The column connecting device for a container spreader according to claim 1, wherein a screw portion is provided at a lower end portion of the connecting rod, and the screw portion is screwed to a connecting plate provided on the lower column. A position where the upper column protrudes from the lower column by a predetermined height is set as a lower movement lower limit position, and the protruding height is suspended from the lower surface of the twist lock box fixed to the upper end of the upper column. The strut connecting device for a container spreader according to claim 1, wherein the strut connecting device is set so as to be slightly larger than a drooping amount of the twist lock pin.

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