JPH0349822A - Band saw and cutting method of metal material used thereof - Google Patents

Abstract

PURPOSE:To facilitate the cutting of a material difficult to cut and to prolong the service life by alternately fitting a high blade and low blade of a sintered hard alloy made tip having a rake angle, front face relief angle and set angle and having a side part relief angle with both shoulders being cut down to a steel made blade body. CONSTITUTION:Cutting is progressed by the edge tip 31 of an acute angle formed by a rake angle alpha, front face relief angle beta and side part relief angle deltaand executed alternately in the center part depth direction and both sides horizontal direction by the combination of A and B blades whose heights and the cutting-off areas P and Q of both shoulder parts differ. At the time when a band saw is advanced along the face of its blade body 1, the blade body 1 is made in the shape twisted excessively a little because of the cutting face being curved but it becomes a proper twist by making the cutting-off areas P and Q of the tip 32 both shoulders asymmetrical. The cutting lightens the load and on the other hand selects the traveling speed higher, making a proper cutting conditions divided by the hardness in working and increasing the cutting amount per unit hour.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an improved band saw for cutting metal materials, and also to an improved cutting method carried out using the band saw. [Conventional technology] For example, when manufacturing a mold from mold steel, it is necessary to cut a large steel material with a wide cutting area. This cutting must not introduce any new strain into the material, and
Since we want to achieve high dimensional accuracy, we must use a mechanical cutting method using a band saw instead of using a frame cutter. Conventional band saws are made by welding a high-speed steel band to a blade made of lll and processing it into a sawtooth shape, but it takes a long time to cut materials that are difficult to process. It cannot be said to be efficient. A band saw that enables high-speed cutting has been proposed in which the steel blade is preformed into a serrated shape, and a cemented carbide tip is attached to the blade edge by means such as electron beam welding. (For example, Special Publication No. 49-37957). [Problems to be Solved by the Invention] The first object of the present invention is to improve a band saw of the type in which a cemented carbide tip is attached to the cutting edge of a blade made of vA, so that it can also be used for cutting loosely processed materials. The goal is to provide something that can be used to advantage. A second object of the present invention is to provide a method for efficiently cutting metal materials using the band saw described above. [Means for Solving the Problem] As shown in FIGS. 1 and 2, the band saw for cutting metal materials of the present invention has a blade (1) made of vA and a large number of blades made of cemented carbide or Ceramic chips (3A, 3B>
In a band saw in which the saw blade is formed by attaching by welding,
Each insert has an acute cutting edge (31) defined by a rake angle (α) and a front relief angle (β) when viewed from the side, as shown in FIGS. 3 to 5, for example, and when viewed from the cutting direction. It has a hexagonal blade surface (32) with both shoulders of an inverted trapezoid that decreases from the top of the blade to the base with a set angle (γ), and is defined by a lateral clearance angle (6) when viewed from the top of the blade. The A blade has an inverted trapezoidal cross-sectional shape and has a high cutting edge and a large cutting area on both shoulders, as shown in Figures 3 to 5, and the A blade has a low cutting edge, as shown in Figures 6 to 8. It is characterized by the fact that every other blade has a B blade with a small scraping area on both shoulders. The preferred ranges and typical values of various angles such as clearance angles shown in FIGS. 3 to 8 are summarized as follows. ΔΣ Double rake angle αA=αB Front clearance angle BA=β8 Set angle Ha=γ8 Side clearance angle δ. =68 Scraping angle εA " εB Range Typical value 10~20' 15°O~]O° 5°2~5° 3°O~6° 4°35~45° 40°37~47° 42°A The difference in height between the blade and the B blade varies depending on the size of the blade and tip, but for bandsaws of typical sizes,
Absolute value ranges from 0.1 to 0.3 m, usually 0.24
The degree is appropriate. As for the width of the tip, it is best to make the B blade slightly wider than the A blade, and the value also varies depending on the size, but the height difference for a band saw of a typical size as mentioned above is 0° 11J! Less than r1, typical value is 0
．． Approximately 02711111 is appropriate. When making the chip asymmetrical, the ratio of the removed areas of both shoulders, that is, PA/Q^ in Fig. 5 and PB/ in Fig. 8,
The appropriate value of QB is 1.0 to 1.2, typically 1.15. By making the area to be removed on both shoulders of the tip larger on one side and smaller on the other with respect to the plane of symmetry of the blade, it is possible to improve the straightness of the blade when cutting with twisting while the blade is running. A band saw is also included within the scope of the present invention. The A blade and B blade shown in Figures 5 and 7 are PA/QA
It is designed asymmetrically with a ratio of =PB/Q13 =1.15. The method for cutting metal materials of the present invention uses the band saw described above, with a load of 300'j/evt or less and a running speed of 25
It consists of applying a band saw to the metal material and cutting it under conditions selected according to the workability of the metal material within the range of ~200 m/ll1 inch. When comparing the workability of typical metal materials, they can be grouped as follows. Appropriate cutting conditions can be determined experimentally for each group from the ranges described below. [Function] Cutting is performed by the shape of the cemented carbide tip described above, that is, the acute cutting edge formed by the rake angle (α), front relief angle (β), and side relief angle (δ). At this time, A blade and B blade, which have different heights and scraping areas on both shoulders,
By combining the blades, cutting is performed alternately in the depth direction of the central portion and in the lateral direction of both survey portions. Figure 9 is A
The shaded area in the center is cut by the blade, and FIG. 10 shows the shaded areas on both sides cut by the B blade. In this way, cutting can be performed under conditions where cutting resistance to the saw teeth is relaxed. A band saw is driven and moved between two drums,
In many cases, the blade is supported in a twisting manner in the area where cutting is to be performed and pressed against the material to be cut. At this time, a force acts on the blade to restore its shape against the twist, causing distortion in the blade, causing the cutting edge to curve slightly inward, that is, to the side opposite to the twisting direction. Therefore, when the band saw is pushed along the surface of its blade, the cut surface tends to be curved. To avoid this, the blade should be pushed slightly (for example, 0.
5-1°) must be used in an over-twisted form. On the other hand, if the areas to be shaved off on both chip shoulders are made asymmetrical, more cutting will be performed on the side where more chips are protruding, resulting in a tendency for the cut surface to curve in that direction. By offsetting these two tendencies, the above-mentioned excessive twisting can be avoided. Of course, depending on the conditions of use, it may not be possible to reduce the excessive twist angle to zero, but even in that case, the asymmetrical tip facilitates straight cutting by adjusting this angle. In the method of cutting metal materials of the present invention using the band saw described above, cutting with a conventional band saw using cemented carbide or a band saw made of high-speed steel is usually carried out at a load of 600 g/cti or less and a running speed of 15 to 80 TrL/cti. This is a cutting method that reduces the load and increases the running speed compared to the cutting method that was used under the minimum cutting conditions. Appropriate cutting conditions for each group divided by processing difficulty described above are shown below in comparison with cutting conditions employed in the prior art. (Load) 9/ai Group Conventional technology 1 400-560 2 300-460 3180-340 4 80-220 (Traveling speed) m/ff1in Gu stop 2 1-strike 110-20 2 25-40 3 40-70 4 75-120 Rikata Ashiichi for one book 200-310 160-260 100-200 60-140 Method of the present invention 25-40 45-70 80-130 140-200 In this way, the chip By reducing the amount removed by traveling and instead increasing the traveling speed, the amount of cutting per unit time can be increased. It is shown that when cutting is carried out at the same cutting rate, for example 70 i/min, there is a big difference in the durability and life of the band saw between cutting with a conventional heavy load and cutting with a light load according to the present invention. , there is an example as shown in FIG.

【Example】

Prepare a chip made of cemented carbide with a hardness of Hv = 19000 to 20000, the size shown below, and the angle of each part adopting the representative value described above, Ehe blade - B blade height 5.35 m 5.12 mm Height difference 0.2m Width 2.61mm 2.63M Blade thickness 1.6#, width 57m, total length (electronic belt > 7
．． A band saw with a length of 6 m and a tip pitch of 2.6 m was manufactured. Using this band saw, the circumferential speed (travel speed > 70TrL/mi)
A round bar of plastic mold steel rNAK55J (manufactured by Daido Steel) with a diameter of 650 m was cut at n. Cutting rate 70.6cm/min, cutting area 182.50
A score of 0i was obtained. This corresponds to 2.5 times the cutting rate and 6 times the cutting area compared to when a high-speed steel bandsaw is used. Using the same band saw, titanium alloy (Ti-6AJ2-4V
) when cutting a round bar with a diameter of 300 m at a circumferential speed of 40 TrL/min, the cutting rate was 25 ai/min, and the cutting area was 8.
Cutting was possible with a result of 0.0OOi. As expected, with the same band saw, a round bar of the same diameter made of pure titanium was cut at a circumferential speed of 70 m.
When cutting at /min, the cutting rate is 100aA/1ll.
In, a cutting area of 40,000 cIi was obtained.

【Effect of the invention】

The band saw of the present invention can easily cut materials that have hitherto been difficult to cut, and has a long service life. When using the cutting method of the present invention, the amount of cutting per unit time increases due to the above-described benefit, and accordingly, cutting can be performed at a higher speed than before.

[Brief explanation of drawings]

1 and 2 are schematic diagrams showing the shape of a band saw of the present invention, with FIG. 1 being a side view of the saw blade portion and FIG. 2 being a plan view. 3, 4, and 5 are detailed views showing the shape of the "A blade" in an example of the band saw of the present invention, and FIG. 3 is a side view similar to FIG. FIG. 4 is a plan view similar to FIG. 2, and FIG. 5 is a view taken from the third station. 6, 7, and 8 are detailed views showing the shape of the "B blade" in an example of the band saw of the present invention, and correspond to FIGS. 3 to 5, respectively. FIGS. 9 and 10 are diagrams illustrating the state of cutting by the band saw of the present invention. FIG. 11 is a graph showing the effect of cutting metal using the band saw of the present invention in terms of the relationship between the traveling speed of the saw blade and the service life when cutting is performed at a constant cutting rate. 1... Blade 3A... Tip for A blade 3B... Tip for B blade β... Front clearance angle δ... Lateral clearance angle α... Rake angle γ... Set angle

Claims (3)

[Claims] (1) In a band saw in which a saw blade is formed by attaching a large number of cemented carbide or ceramic tips (3A, 3B) to a steel blade (1) by welding, each tip has a rake angle when viewed from the side. It has an acute-angled cutting edge (31) defined by (α) and a front relief angle (β), and has both shoulders of an inverted trapezoid that decreases from the top to the root with a set angle (γ) when viewed from the cutting direction. It has a hexagonal cutting surface (32), and has an inverted trapezoidal cross-sectional shape defined by the lateral relief angle (δ) when viewed from the top of the blade, and has a high cutting edge and a large cutting area on both shoulders. A band saw for cutting metal materials, characterized in that a large A blade and a B blade with a low cutting edge and a small scraping area on both shoulders are attached to every other blade. (2) A claim in which the cutting area of both shoulders of the tip is made larger on one side and smaller on the other side with respect to the plane of symmetry of the blade, thereby improving the straightness of the blade in cutting where twisting occurs when the blade runs. 1 bandsaw. (3) Using the band saw of claim 1 or 2, 300g/c
A method for cutting a metal material, comprising cutting under conditions selected according to the workability of the metal material, such as a load of less than m^2 and a running speed within the range of 25 to 200 m/min.