JP7560879B2 - Shearing method using a shearing tool - Google Patents

Description

The present invention relates to shearing tools that require a large torque, commonly called wire cutters or bolt clippers.

It is known that a bolt cutter has been used in which the opening and closing movements of a pair of blade members with cutting edges are linked, as disclosed in Patent Document 1 for example. In order to synchronize the movements of the pair of blade members, gear parts are integrally formed with the blade members, and the gear parts are in mesh with each other.

Utility Model Publication No. 59-193626

However, because the gear section is subjected to a very large load, it is prone to wear and tear, which can lead to a decrease in shearing performance. When such a problem occurs, it is necessary to replace the entire blade member, which leads to high costs.

The present invention aims to provide a shearing device that can extend the life of the shearing device.

The present invention is a shearing tool comprising a base part provided with a pair of shaft parts, and a pair of blade members arranged facing each other and supported by the respective shaft parts of the base part, the pair of blade members rotating in relation to each other about the shaft parts, thereby sandwiching and shearing a predetermined object to be sheared between the blade tips formed on each blade member, the shearing tool being characterized in that a gear part is formed on each blade member, the gear parts are arranged facing each other, and a spacer member having teeth that mesh with the gear parts is interposed between the gear parts, and the pair of blade members rotates while the teeth of the spacer member mesh with the gear parts of the pair of blade members.

In this configuration, the spacer member functions as a so-called "planetary gear," and the so-called gear teeth mesh at two locations: the gear portion of one blade member and one tooth portion of the spacer member, and the gear portion of the other blade member and the other tooth portion of the spacer member. This means that the load applied during shearing is distributed at each meshing location, preventing excessive stress concentration and making it difficult for defects due to wear and tear of each blade member to occur. In addition, if a material with a relatively low hardness is selected for the material constituting the spacer member compared to the material constituting the blade member, the spacer member will have a shock absorbing effect, making it possible to further prevent wear and tear of the blade member. Furthermore, even if the tooth portion of the spacer member wears out or is damaged, there is no need to replace the entire blade member as in the past, and the cost of replacing parts can be significantly reduced.

In addition, when shearing objects of different dimensions, it is generally necessary to change the axial distance between a pair of blade members for each object to be sheared in order to appropriately change the point of force or point of action. However, in the configuration of the present invention, by using a spacer member with dimensions corresponding to the changed axial distance, it is possible to reuse and continue using the blade members as they are without modifying them, and even in such cases, it is possible to significantly reduce the costs associated with replacing parts.

In addition, by appropriately changing the material of the spacer member to change the hardness, it is also possible to change the torque adjustment during shearing. In addition, by appropriately changing the shape of the teeth of the spacer member, it is also possible to relatively vary the torque in the initial section, the torque in the middle section, and the torque in the final section when the blade member is opened and closed, and it is possible to realize the operation of the blade member with increased instantaneous acceleration in the middle section, for example.

When using the above-mentioned shearing tool to shear objects of different dimensions, a shearing method using a shearing tool is proposed that includes the steps of: changing the axial distance between the pair of shaft parts to match the dimensions of the objects to be sheared; supporting the blade members on the shaft parts after changing the axial distance; and interposing spacer members of a predetermined dimension between each of the gear parts of the blade members supported on the shaft parts.

As described above, the present invention has the excellent effect of extending the life of components.

FIG. 2 is a plan view of a shearing device according to an embodiment. 1A and 1B show a shearing tool with an open cutting edge, in which FIG. 1A is a partially cutaway plan view, and FIG. 1A and 1B show a shearing device with a closed cutting edge, in which FIG. 1A is a partially cutaway plan view, and FIG. 1B is a partially enlarged cross-sectional view of FIG.

Embodiments of the present invention will be described with reference to the following examples.

As shown in FIG. 1, the shearing device 1 comprises a base portion 10 made of a metal plate-like member and a pair of metal blade members 20, 20 that are used.

The base portion 10 has a generally rectangular flat plate shape and is provided with a pair of shaft portions 11, 11. The pair of shaft portions 11, 11 protrude in parallel in the same direction.

The pair of blade members 20, 20 are roughly symmetrical to each other, with cutting edges 21, 21 formed at the tip of each. The pair of blade members 20, 20 are supported by the shafts 11, 11 of the base portion 10 and arranged opposite each other, and are linked to each other so that they can rotate. The linking mechanism will be described in detail later.

The air hammer mechanism 60, which serves as a power source, is connected to the base end of the blade members 20, 20 via a predetermined link mechanism 70. When the piston provided in the air hammer mechanism 60 moves back and forth, the pair of blade members 20, 20 rotate in the opening and closing directions in conjunction with each other based on the operation of the link mechanism 70 that accompanies this movement.

Next, the main parts of the present invention will be explained with reference to Figures 2 and 3.

In the pair of blade members 20, 20 described above, gear portions 22, 22 facing each other are formed at positions adjacent to the cutting edges 21, 21.

Furthermore, a spacer member 40 is interposed between the gear parts 22, 22. Specifically, the spacer member 40 is made of a long member, and multiple teeth 42 that mesh with the gear parts 22, 22 of the blade members 20, 20 are formed along the longitudinal direction.

In this configuration, when the air hammer mechanism 60 is driven, the gears 22, 22 of the blade members 20, 20 mesh with the teeth 42 of the spacer member 40 to shear and divide the predetermined workpiece W. Specifically, as shown in FIG. 3(a), when the piston of the air hammer mechanism 60 advances toward the blade member 20, the base ends of the pair of blade members 20, 20 move away from each other, and the cutting edges 21, 21 move closer to each other. Then, the cutting edges 21, 21 bite into the sheared object (e.g., rod material such as pipe material) sandwiched between the approaching cutting edges 21, 21 while being held by the cutting edges 21, 21, and finally break it. When the cutting edges 21, 21 are closest to each other, the cutting edges 21, 21 are parallel to each other, and a predetermined gap is formed between the cutting edges 21, 21. The width of the gap is determined in advance according to the size of the sheared object, and is set to a size smaller than the width of the sheared object. On the other hand, as shown in FIG. 2(a), when the piston of the air hammer mechanism 60 retreats relative to the blade member 20, the base ends of the pair of blade members 20, 20 approach each other, and the blade tips 21, 21 move apart.

In the above embodiment, the dimensions and shapes of each part can be freely selected as appropriate. The above-mentioned gear parts 22, 22 and the spacer member 40 constitute the torque transmission mechanism 50 of the shearing device 1.

Here, a pair of long-hole-shaped shaft attachment parts may be provided on the base part 10, and the shaft parts 11 may be attached to each of the shaft attachment parts, so that the distance between the shaft parts can be changed as appropriate. For example, a tool adjustment method may be adopted in which the distance between the shaft parts is made larger than in the above embodiment to increase the separation distance between the blade members 20, 20, and then a spacer member 40 of a size that is appropriately interposed between the gear parts 22, 22 of the blade members 20, 20 is placed.

Based on the technical ideas described above, the following configuration is also proposed. That is, in an expansion tool having a base portion with a pair of shaft portions and a pair of expansion members supported by the shaft portions of the base portion, the pair of expansion members each have gear portions facing each other, and a spacer member having teeth that mesh with the gear portions is interposed between the facing gear portions.

Reference Signs List 1: Shearing tool 10: Base portion 11: Shaft portion 20: Blade member 21: Blade tip 22: Gear portion 40: Spacer member 42: Tooth portion 50: Torque transmission mechanism

Claims (1)

A base portion provided with a pair of shaft portions;
A pair of blade members each pivotally supported on a shaft portion of the base portion and disposed opposite to each other;
Equipped with
A shearing device in which the pair of blade members rotate relative to each other around the shaft portion, thereby sandwiching and shearing a predetermined shearing object between blade tips formed on each blade member,
A shearing method using a shearing tool in which a gear portion is formed on each blade member, the gear portions are arranged opposite to each other, and a spacer member having teeth that mesh with the gear portions is interposed between the gear portions, and the pair of blade members rotate while the teeth of the spacer member mesh with the gear portions of the pair of blade members ,
changing the axial distance between the pair of shaft portions in accordance with the dimensions of the object to be sheared;
a step of supporting the blade member on the shaft portion after changing the center distance;
a step of interposing a spacer member of a predetermined dimension between each of the gear portions of the blade member journaled on the shaft portion;
A shearing method using a shearing device, comprising :

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