Reuleaux-triangular circular saw single-bevel blade for mounting on circular power saw

Abstract

[Problem] To accurately cut a foamed-resin-based building insulation material that is surface-coated with a thin aluminum film or sheet, while controlling the occurrence of foam dust to a minimum. [Solution] In the present invention, on a woodworking circular power saw, which is a handheld power tool, mounted is a circular saw blade of Fig. 1 that has a Reuleaux triangle form and has the blade edge ground to a single-bevel edge. A foamed-resin-based building insulation material that is surface-coated with a thin aluminum film or sheet is cut.

Description

Reuleaux triangular circular saw single blade to be attached to an electric circular saw

[0001] This relates to an electric circular saw blade that cuts foam resin insulation materials for construction that are covered with thin aluminum films, thin plates, or fiber sheets, while suppressing dust, using an electric circular saw, which is a handheld power tool.

[0002] Conventional handheld circular saws for cutting architectural foam insulation use dozens of saw-like hard tips positioned around the periphery of a circular metal plate. For example, for a 1mm thick metal plate, the hard tips extend to the left and right, resulting in a cutting width of 1.8mm. In this case, a single cut of 50mm thick foam insulation over a cutting distance of 910mm generates hundreds of thousands of particles of dust. This amounts to more than 100 cuts per day. This large amount of dust can be harmful to workers' health, and cutting on the roofs of architects' buildings is known to cause slippage and hazards. The dust generated by cutting foam insulation is lightweight and fine, scattering in the wind and causing a nuisance to neighbors, while cleanup requires significant time and effort.

[0003] Although power tool manufacturers and peripheral equipment suppliers around the world have implemented measures to address dust with some of their products, the problem has yet to be solved. There are methods for cutting without generating dust, such as using hand tools like utility knives, but cutting by hand is slow, the cutting angle is extremely inaccurate, and it is difficult to cut to match the roof slope, resulting in poor workmanship. Therefore, cutting is generally performed using an electric circular saw, which is fast and has a precise cutting angle.

[0004] One way to reduce dust when cutting foam insulation for building materials is to attach a Reuleaux triangular blade to an electric circular saw. A typical circular saw blade rotates around a circular metal plate with dozens of saw-like hard tips, cutting through the material by scratching it. A Reuleaux triangular blade, however, cuts into the material with a sliding motion. This blade can reduce dust from thermally fused foam insulation to less than one-hundredth of its original size. For every 1 mm of metal plate cut with a Reuleaux triangular blade, approximately 0.6 mm of foam insulation is lost, with the remaining 0.4 mm acting as cutting resistance. While this remaining 0.4 mm is not a problem with standard foam insulation, when cutting foam insulation coated with a thin aluminum film, no loss is observed, and the 1 mm of the circular saw blade itself acts as cutting resistance, disrupting the saw's ability to move in a straight line. The present invention provides an electric circular saw blade that can cut straight even foam resin insulation materials for construction that are surface-coated with a thin aluminum film or plate.

[0005] By dividing the aluminum thin film or sheet attached to building foam resin insulation into a flat side that is not subjected to cutting resistance and an inclined side that pushes away the cutting resistance, and by grinding it into a single-edged blade with the flat end as the cutting edge, the straightness of the electric circular saw can be maintained.

[0006] There is a saw blade adjustment technique called "relaxing" for both traditional saws and modern rotary circular saw blades. This involves thinning the flat surface of the metal plate by extending the cutting edge to the left and right (asari). Even slight distortions or bulges in the flat surface of the saw blade metal plate create unnecessary resistance during cutting. For an electric circular saw blade, the cutting width is 1 mm for the metal plate, and 0.4 mm of the cutting edge to the left and right (asari), for a total of 1.8 mm, making it easier to cut through 1 mm of metal plate. In this application, the cutting width of the metal plate is 1 mm and 0.6 mm or less, so a single-edged blade is used. The flat surface is completely punched out, creating numerous hollow holes and grooves to reduce cutting resistance on the flat surface of the metal plate. If the area of ​​the flat surface is halved, the probability of distortion and bulging is halved, and friction is also halved. The holes and grooves in an electric circular saw blade are known to allow air to pass through for cooling and heat dissipation, to save energy by reducing the weight of the metal plate, and to cushion sudden loads on the cutting edge, but in this application they also serve to indicate the distance from the center.

[0007] When cutting foam resin insulation materials for construction that are covered with thin aluminum films or plates, workers can complete the work without being exposed to large amounts of dust.

[0008] When cutting foam resin insulation materials for construction that are covered with thin aluminum films or plates, workers can significantly reduce cleaning time.

[0009] From left to right, the diagrams are a plan view, a cross section, and an enlarged view of the single-edged blade in the circle on the right. Reference number 1 indicates the hole where the metal circular saw blade is attached to the electric circular saw, which is designated as the inner diameter according to the Japanese Industrial Standards. Handheld circular saws for woodworking, typically with an outer diameter of 100 mm to 200 mm, often have an inner diameter of 20 mm in Japan. In the United States, 5 / 8 inch (approximately 16 mm) is common, regardless of outer diameter. Reference number 2 indicates a completely punched-out hollow groove, indicating the intermediate distance from the center of rotation to the tip of the cutting edge. Conventional grooves engraved or painted on the surface of metal plates disappear due to friction and become obscured by the adhesion of resin or rust. However, the grooves of this invention are hollow, so they do not disappear due to friction, do not adhere to resin or rust, and do not become invisible. They are commonly referred to as slits. Reference number 3 indicates the tip of the cutting edge at the tip, which is a single-edged shape. Reference number 4 indicates the tip of the cutting edge at the periphery, which is a single-edged shape. In this application, we refer to the "single-edged" designation commonly used for kitchen knives. Number 5 is a completely punched hollow hole. The effect is the same as number 2.

[0010] This involves attaching a single-blade triangular circular saw blade made by the Reuleaux company to a handheld electric circular saw for woodworking and rotating it to cut foam resin insulation for construction, which is surface-coated with a thin aluminum film or plate, which is the material to be cut.

[0011] It is difficult to build houses and other buildings exactly according to theoretical figures, and errors of several millimeters can occur. A handheld circular saw for woodworking can be carried and used by a person, and by cutting foam resin-based building insulation already attached to roofs and walls of buildings, it is possible to fine-tune the shape and dimensions of the insulation, eliminating errors.

[0012] The Reuleaux triangular circular saw blade was invented and used 21 years ago. We have repeatedly conducted experiments to explore the dangers and problems of using it in rotation, even bringing it into contact with wood and nails, which are not the intended cutting material, but have not yet experienced any damage or deformation. However, we discovered that it loses its ability to cut straight when used with foamed resin-based building insulation materials that are coated on one or both sides with thin aluminum films or plates, which are intended to improve the performance of conventional foamed resin-based building insulation materials. To overcome this, we shaped and sharpened the cutting edge to one side, which allowed us to maintain its ability to cut straight.

[0013] Demand for architectural foam resin insulation is increasing due to international trends to reduce the energy consumption of heating and cooling in buildings and reduce environmental impact, such as the Zero Energy House initiative in Japan by the Agency for Natural Resources and Energy and the mandatory construction of highly insulated homes in the UK. However, cutting quickly and accurately using a power circular saw is common, and it is well known both in Japan and around the world that workers are plagued by large amounts of dust. Global power tool manufacturers have developed and sold jigsaw blades, table saw blades, and specialized power tools to address the cutting of architectural foam resin insulation. However, these tools fall far short of the original in terms of cutting speed, cutting angle accuracy, and dust suppression when cutting thermally fused architectural foam resin insulation. Our products set the global standard for cutting architectural foam resin insulation.

Claims

1. A rotary circular saw blade for a handheld power tool for woodworking, which cuts a building foam resin-based heat insulator surface-coated with an aluminum thin film or thin plate while suppressing dust, wherein the outer shape of the rotary circular saw blade that rotates and cuts a metal plate is a roulo triangle, and the polished cutting edge has one side as a plane and the other side is inclined from near the cutting edge, and the end of the plane is a single-edge rotary circular saw blade with the cutting edge.

2. The rotary circular saw blade according to claim 1, wherein the rotary circular saw blade has holes or grooves indicating each intermediate distance from the rotation center to the apex of the cutting edge.

Images