JP2012001300A - Attachment for forklift and freight handling method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an attachment or the like for a forklift capable of lifting, conveying, and storing a curved concrete product in a stable state.SOLUTION: The attachment includes a pair of nearly L-shaped fork auxiliary bodies (11A, 11B) installed at respective fork claws (26a, 26b) of the forklift where an interval (S) between two right and left fork claws can be adjusted. Each fork auxiliary body comprises: a base (111) installed and fixed so that the base (111) is fitted to cover the fork claw of the forklift; and a strut (112) provided so that the strut (112) nearly vertically rises from the front end of the base. With respect to a lifting position of the concrete product, an interval (S) between the pair of the fork claws is adjusted so that the gravity center (G) of the concrete product (30) is positioned at a side closer to the forklift (20) than an area having a width (W) and connecting positions where the two right and left fork claws lift the concrete product.

Description

  TECHNICAL FIELD The present invention relates to an attachment for a forklift and a load handling method using the same, and more specifically, an attachment provided on a forklift for handling a curved concrete product, and a curved concrete product by a forklift equipped with the attachment. It is related with the lifting and transporting method.

A forklift, also called a forklift truck, is a special vehicle equipped with a mast at the front of a powered vehicle body and configured to move up and down a fork for holding luggage along this mast. For transportation, it is widely used in factories, warehouses, collection sites, construction sites, etc.
In addition to the fork, various types of attachments can be attached to the mast depending on the form of the luggage and the work content.
For example, Patent Document 1 below discloses an attachment configured as a tire stacking device, Patent Documents 2 and 3 disclose snow removal attachments, and Patent Document 4 further discloses. Discloses an attachment for handling a drum can.

However, forklift attachments for handling, for example, curved concrete products constituting the walls of tunnels and large drains, that is, curved concrete products whose inner and outer peripheral surfaces are part of a substantially cylindrical curved surface, Never been offered before.
Such curved concrete products are large, heavy, and have a special shape, so it is difficult to balance when handling with a forklift, and if the balance is lost, the product may fall or fall. Not only was the product damaged, it was very dangerous.
Therefore, there is a problem that handling of such a curved concrete product with a forklift requires great care and is troublesome, and usually a large crane vehicle or the like is used for handling the load.

Japanese Patent Laid-Open No. 05-139698 Japanese Patent Laid-Open No. 10-088543 Japanese Patent Laying-Open No. 2005-220711 JP 2000-016792 A

Therefore, an object of the present invention is to stably attach a curved concrete product as described above by a forklift attachment capable of lifting and transporting the curved concrete product in a stable state and a forklift equipped with the attachment. The idea is to provide a method that can be lifted and transported.
In the present invention, the term “curved concrete product” is not necessarily limited to only a concrete product, but broadly encompasses all heavy objects having a generally curved shape.

To achieve the above object, a forklift attachment for handling a curved concrete product according to the present invention comprises:
An attachment consisting of a pair of substantially L-shaped forks attached to each fork claw of a fork lift constructed so that the distance between the two fork claws can be adjusted by moving the left and right fork claws to the left and right respectively. Each fork auxiliary body
A base portion mounted and fixed so as to fit over the fork claw of the forklift;
A support provided to stand substantially vertically from the front end of the base,
In this case, it is also recommended to attach an oblique reinforcing bar between the back surface of the support column and the upper surface of the base, or to install a damper on the front surface of the support column.

In order to achieve the above object, the method according to the present invention includes:
A fork lift in which the fork lift attachment according to the present invention is attached to each fork claw of the fork lift configured such that the distance between the two fork claws can be adjusted by moving the left and right fork claws to the left and right. A method of lifting and transporting a curved concrete product having a circumferential surface and a circumferential surface part of a substantially cylindrical curved surface,
Holding the curved concrete product in an upright state such that the generatrix of the substantially cylindrical curved surface is substantially vertical;
When the concrete product is lifted from below by the pair of fork claws in a state where the columns of the pair of fork auxiliary bodies attached to the two left and right fork claws are close to or in contact with the inner peripheral surface of the concrete product Adjusting the distance between the pair of fork claws such that the center of gravity of the concrete product is positioned closer to the forklift than the area of the width connecting the two left and right fork claws lifting the concrete product,
Advance the forklift and scoop the concrete product by slightly raising the pair of fork claws with the struts of the pair of fork auxiliary members being close to or in contact with the inner peripheral surface of the concrete product. A process of transporting a concrete product to a desired location by running a forklift;
It is comprised from these.

According to the present invention, a pair of substantially L-shaped fork auxiliary bodies, which are attachments for handling loads according to the present invention, are attached to each fork pawl of the forklift, and the columns of these fork auxiliary bodies are attached to the inner peripheral surface of the concrete product. The concrete product is lifted from the bottom by the pair of fork claws in the state of being in contact with or in contact with each other. In this case, the center of gravity of the concrete product is the place where the left and right fork claws lift the concrete product respectively. When the concrete product is lifted after adjusting the distance between the pair of fork claws so that it is located closer to the forklift than the area of the width to be tied, the center of gravity of the concrete product is the two left and right fork claws as described above. Each forklift than the area of the width connecting the places where concrete products are lifted Because of the near side, concrete products leaning on struts of the fork auxiliary body as going to fall into the truck side, are intended to be stably supported by the struts. In other words, if the concrete product is gripped inside the center of gravity of the concrete product, the concrete product will fall to the inner surface side, and the concrete product that is about to fall to the inner surface side will be transported in a state that is stably supported by the fork auxiliary column. To do.
Therefore, there is no need to firmly connect the pair of fork claws and the concrete product with another rope or the like, and the curved concrete product can be lifted and transported in a stable state. Therefore, it is not necessary to use a large crane vehicle or the like, the working efficiency is improved, and the cost can be saved.

It is explanatory drawing which shows one Example of the attachment for forklifts which concerns on this invention. FIG. 3 is a four-side view of one fork auxiliary body in the forklift attachment shown in FIG. 1. It is explanatory drawing which shows the example of the general forklift truck which attaches and uses the attachment for forklifts which concerns on this invention. It is explanatory drawing which shows the state which attached the attachment for forklifts which concerns on this invention to the forklift shown in FIG. It is explanatory drawing which shows the preparation state which raises the curved concrete product which should be lifted and conveyed, lifts this with the forklift to which the attachment which concerns on this invention was attached, and conveys. It is explanatory drawing which shows the state which lifts the curved concrete product with the forklift to which the attachment which concerns on this invention was attached. It is explanatory drawing which shows the positional relationship of the lifting location at the time of lifting the curved concrete product with a fork nail | claw, and the gravity center of concrete product. It is explanatory drawing which shows a state when conveying the curved concrete product with the forklift which attached the attachment which concerns on this invention. It is explanatory drawing which shows the state when carrying and storing many curved concrete products with the forklift which attached the attachment which concerns on this invention. It is explanatory drawing which shows another state when transporting and storing many curved concrete products with the forklift which attached the attachment which concerns on this invention.

The details of the forklift attachment according to the present invention will be described below with reference to the accompanying drawings.
The present invention is not limited to the illustrated embodiment, and each component can be replaced with another member having an equivalent function.

FIG. 1 is a perspective view showing an embodiment of a forklift attachment according to the present invention. FIG. 2 is a front view of one fork auxiliary body of the forklift attachment shown in FIG. It is shown as a figure (A), a left side view (B), a rear view (C), and a plan view (D).
The forklift attachment 10 according to the present invention includes a pair of fork auxiliary bodies 11A and 11B as shown in FIG.
As shown in FIGS. 4 to 6, these fork auxiliary bodies 11 </ b> A and 11 </ b> B are attached to a pair of fork claws 26 a and 26 b of the forklift 20 and are preferably used for lifting and transporting the curved concrete product 30.

Since both of the pair of fork auxiliary bodies 11A and 11B have the same configuration, only the fork auxiliary body 11A (the one on the right side as viewed from the forklift driver) will be described here.
As shown in FIGS. 1 and 2, the fork auxiliary body 11 </ b> A is a substantially L-shaped attachment having a base portion 111 and a support column 112 that rises substantially vertically from the front end of the base portion 111.
In the illustrated embodiment, the base portion 111 has a hollow box shape made of a metal such as iron. As shown in FIG. By fixing, it is attached to the fork claw 26a. When attaching to the fork claw 26a, the column 112 is attached so as to be located on the front side (the side far from the forklift main body).

In the illustrated embodiment, the support column 112 is manufactured using an H-shaped steel material. However, the column 112 is not necessarily limited to the H-shaped steel material as long as the member is easily fixed to the base 111 and has sufficient strength. Absent.
It is desirable to attach an oblique reinforcing bar 114 between the back surface of the support column 112 and the upper surface of the base portion 111 as shown in the figure.
The large and heavy curved concrete product handled in the present invention is supported by leaning on the support 112 of the fork auxiliary bodies 11A and 11B as will be described later. This is because the fixing strength with 111 needs to be sufficiently strong.
Further, it is desirable to attach a damper (buffer material) 113 to the front surface of the support column 112.
This is to prevent the concrete product from being damaged when the concrete product contacts the support column 112. As the damper 113, a rubber tire or the like may be reused. However, since black rubber may contaminate concrete products, if necessary, cure with clear tape or use raw rubber damper or white rubber damper.
It should be noted that the damper 113 is attached to the outside of the center line of the front surface of the column 112 (the right fork auxiliary body 11A is moved to the right side and the left fork auxiliary body 11B is moved to the left side). Is desirable. That is, since the concrete product is curved, if the height (thickness) of the damper is not sufficient, the edge of the support pillar (H steel) 112 and the inner surface of the concrete product interfere with each other and damage the product (see FIG. 7). ). However, it is not realistic to change the height (thickness) of the damper according to the size and curvature of the concrete product. Therefore, as shown in FIG. 2, the damper 113 is attached so as to be offset outward from the center line of the front surface of the support column 112 (to the right for the right fork auxiliary body 11A shown in FIG. 2). Regardless of the height of the damper, the contact between the concrete product and the edge of the column (H steel) 112 can be prevented.

It is desirable that the height of the column 112 is somewhat higher than the height of the concrete product to be handled.
Further, the shape of the base 111, the fixing means, etc. are not limited to the example shown in the figure, and any form is possible as long as the fork auxiliary bodies 11A, 11B can be firmly fixed to the fork claws 26a, 26b of the forklift. Can be used.
In addition, in the case of a forklift that can tilt the mast back and forth (tilt), the forklift mast is designed to prevent the fork auxiliary body from falling off the fork claws during the lifting and transporting of the concrete product. The fork auxiliary bodies 11A and 11B may be prevented from falling off by inclining somewhat backward and inclining so that the tip side of the fork claw is lifted somewhat.

FIG. 3 shows a general forklift 20 to which a forklift attachment according to the present invention is attached and used.
The forklift 20 has a mast 23 at the front of a vehicle body 21 having a driver's seat 22, and a fork mounting frame 25 to which a pair of left and right fork claws 26 a and 26 b is attached can be lifted and lowered along the mast 23. Yes.
The roller chain 24 is a part of a drive mechanism for raising and lowering the fork mounting frame 25. The roller chain 24 is wound around a sprocket not shown in the figure, and the fork mounting frame 25 is raised and lowered by forward and reverse rotation of the sprocket. Yes.
The fork mounting frame 25 is provided with a mechanism (fork positioner; not shown in the drawing) that allows the distance between the fork claws (opening width) to be adjusted by moving the pair of left and right fork claws 26a and 26b to the left and right. In the present invention, this mechanism is used to stably lift and transport the concrete product by adjusting the distance between the fork claws according to the position of the center of gravity of the curved concrete product.

4 to 6 sequentially show work steps for attaching the attachment 10 of the present invention shown in FIGS. 1 and 2 to the forklift 20 shown in FIG. 3 and lifting the curved concrete product 30 using the attachment 10. .
As shown in FIG. 4, the attachment 10 according to the present invention inserts a fork claw 26 a of a forklift into the inside of the base portion 111 of each fork auxiliary body 11 </ b> A, 11 </ b> B and fixes it with a fixing screw 115. , 26b. When attaching to the fork claws 26a, 26b, as described above, the support column 112 is attached so as to be positioned on the front side (the side far from the forklift main body).

On the other hand, the curved concrete product 30 to be lifted and transported is erected using a reversing machine or the like (not shown) as shown in FIG. 5 and placed on the sleeper 40 made of steel frame or the like. The space for inserting the fork claw is provided through the lower part.
That is, the concrete product 30 to be handled in the present invention generally has a curved shape in which the inner peripheral surface 30a and the outer peripheral surface 30b are part of a substantially cylindrical curved surface. 30c is an upper surface, 30d is a lower surface, and 30e is a substantially cylindrical curved generatrix.
When such a curved concrete product 30 is lifted using the attachment of the present invention, it is erected using a reversing machine or the like so that the substantially cylindrical curved generatrix 30e is substantially vertical, and is brought into its standing state. The forklift 20 is slowly moved toward the inner peripheral surface 30a of the held concrete product 30, and the columns 112 (or the dampers 113) of the pair of fork auxiliary bodies 11A and 11B attached to the two left and right fork claws are made into concrete. As shown in FIG. 6, the concrete product 30 is lifted from below by the pair of fork claws 26 a and 26 b in a state in which the product 30 is close to or in contact with the inner peripheral surface 30 a of the product 30.
In this case, the lifting position of the fork claws 26a and 26b with respect to the lower surface 30d of the concrete product 30 is a feature of the load handling method according to the present invention, and this point will be described with reference to FIG.

FIG. 7 is a schematic diagram of the concrete product 30 curved in an arc shape as viewed from above when the fork claws 26a and 26b to which the fork auxiliary bodies 11A and 11B according to the present invention are attached are lifted.
As shown in the drawing, in the present invention, the concrete product is located closer to the forklift than the region of the width W connecting the portions (hatched portions in the figure) where the two left and right fork claws 26a, 26b lift the concrete product 30 respectively. The distance S (fork span) between the pair of fork claws is adjusted so that the center of gravity G of 30 is located. As can be understood from the figure, the shorter the fork span S, the farther the fork claw lifts the concrete product away from the forklift 20, and the longer the fork span S, the closer the fork claw lifts the concrete product to the forklift 20. Become. Therefore, by adjusting the fork span S in advance according to the concrete product 30, the center of gravity G of the concrete product 30 is from the region of the width W connecting the two fork claws 26 a and 26 b lifting the concrete product 30. Can also be positioned closer to the forklift 20 so that the raised concrete product can rest against the fork auxiliary column 112.
That is, when the fork span S is large, a moment is generated in the concrete product to fall to the opposite side of the forklift. When the fork span S is small, the concrete product has a forklift side, that is, a fork auxiliary column. A moment that leans to the side is generated. Therefore, in the present invention, it is important to make the fork span S smaller than the position of the center of gravity.
In addition, when the shape of the curved concrete product is a simple shape and the center of gravity position can be easily obtained by a calculation formula, the center of gravity position may be obtained in advance.

As described above, when the position of the center of gravity is located closer to the forklift 20 than the region of the width W connecting the lifting locations, when the concrete product 30 is lifted, the concrete product 30 is placed on the side with the center of gravity (of the forklift 20). It is supported so as to fall down toward the existing side) and to lean against the support 112 of the fork auxiliary body.
Therefore, the concrete product 30 does not fall toward the outside (the side opposite to the side where the forklift 20 is present), and the column 112 of the fork auxiliary bodies 11A and 11B is in a state of tilting to the near side as viewed from the driver. Is maintained in a stable state.
Therefore, it is not necessary to firmly tie the concrete product 30 to the fork claws 26a, 26b and the fork mounting frame 25 with another rope or the like, and the two fork claws 26a to which the fork auxiliary bodies 11A, 11B are attached. By simply adjusting the interval 26b in advance as described above, the curved concrete product 30 can be lifted and transported in a stable state. Therefore, it is not necessary to use a large crane vehicle or the like, the working efficiency is greatly improved, and the cost can be reduced.

In FIG. 8A, as described above, fork lifts 20 in which the fork auxiliary bodies 11A and 11B are attached to the two fork claws 26a and 26b and the distance S between the fork claws is adjusted as described above are used for the concrete product. A state in which 30 is transported in a stable state is shown.
Further, in FIG. 8B, in order to transport the mast 23 in a more stable state, the mast 23 is tilted somewhat backward (tilt), and the fork pawls 26a and 26b are tilted so that the tip ends are lifted somewhat. A state in which the stability of the product 30 is ensured is shown.

FIG. 9 shows a state in which a concrete product transported by a forklift with an attachment according to the present invention can be stored in a predetermined storage location as it is. At that time, it is not necessary to remove the rope as in the case of a crane, transfer to another cart, or change the direction with a reversing machine.
That is, when using the forklift to which the attachment according to the present invention is attached, the curved concrete product 30 can be stably transported while being kept in an upright state as described above, and in a state of being stored, the sleeper 40 is left as it is as shown in FIG. Simply place them on top of each other in order to store curved concrete products side by side without interfering with each other. Therefore, handling can always be performed at the same position, the work efficiency is improved, and the space efficiency of the storage place is greatly improved as compared with the conventional case.

FIG. 10 shows a state in which concrete products transported by a forklift with an attachment according to the present invention can be stacked in two stages and stored in a space-saving state.
That is, after placing one or two concrete products 30 on the lower stage, lift the fork to a high position, place one or two on the upper stage, then place one or two on the lower stage again, and then place the upper one on the upper stage. By repeating the operation of placing one or two layers, the curved concrete product 30 can be stored in a space-saving state in two to three stages.

  The present invention is not limited to the above-described embodiment. For example, as described above, the support 112 does not necessarily use an H-shaped steel material, and the fixing screw 115 is also a fixing means other than a screw. Therefore, the present invention encompasses all modifications that can be easily conceived by those skilled in the art from the above description within the scope of the claims.

  As described above in detail, the present invention uses a fork auxiliary body attached to a fork claw of a forklift to raise a concrete product lifting position by the fork claw when the curved concrete product is lifted. Since the concrete product leans against the fork auxiliary column by its own weight and is supported stably, the curved concrete product can be lifted in a stable state without using a large crane or the like. It is possible to provide a forklift attachment that can be transported and a method that can stably lift, transport, and store a curved concrete product using the attachment.

DESCRIPTION OF SYMBOLS 10 Forklift attachment 11A, 11B Fork auxiliary body 111 Base part 112 Support | pillar 113 Damper 114 Reinforcement bar 115 Fixing screw 20 Forklift 21 Car body 22 Driver's seat 23 Mast 24 Roller chain 25 Fork mounting frame 26a, 26b Fork claw 30 Curved concrete product 30a Inner peripheral surface 30b Outer peripheral surface 30c Upper surface 30d Lower surface 30e Busbar 40 Sleepers G Center of gravity of concrete product S Spacing between both fork claws (fork span)

Claims (4)

An attachment consisting of a pair of substantially L-shaped forks attached to each fork claw of a fork lift constructed so that the distance between the two fork claws can be adjusted by moving the left and right fork claws to the left and right respectively. Each fork auxiliary body
A base portion mounted and fixed so as to fit over the fork claw of the forklift;
A support provided to stand substantially vertically from the front end of the base,
Attachment for forklifts for the handling of curved concrete products, characterized by comprising   The attachment for a forklift for handling a curved concrete product according to claim 1, wherein an oblique reinforcing bar is attached between the back surface of the support column and the upper surface of the base portion.   The forklift attachment for handling a curved concrete product according to claim 1 or 2, wherein a damper is attached to a front surface of the support column. The forklift attachment according to any one of claims 1 to 3 is attached to each fork claw of the forklift that is configured such that the distance between the two fork claws can be adjusted by moving the left and right fork claws to the left and right respectively. A forklift that lifts and transports a curved concrete product whose inner peripheral surface and outer peripheral surface are part of a substantially cylindrical curved surface,
Holding the curved concrete product in an upright state such that the generatrix of the substantially cylindrical curved surface is substantially vertical;
When the concrete product is lifted from below by the pair of fork claws in a state where the columns of the pair of fork auxiliary bodies attached to the two left and right fork claws are close to or in contact with the inner peripheral surface of the concrete product Adjusting the distance between the pair of fork claws such that the center of gravity of the concrete product is positioned closer to the forklift than the area of the width connecting the two left and right fork claws lifting the concrete product,
Advance the forklift and scoop the concrete product by slightly raising the pair of fork claws with the struts of the pair of fork auxiliary members being close to or in contact with the inner peripheral surface of the concrete product. A process of transporting a concrete product to a desired location by running a forklift;
A method of lifting and transporting a curved concrete product, characterized in that it consists of:

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