Reducing cutter bit and hard alloy saw blade

Abstract

The invention relates to a reducing cutter head and a hard alloy saw blade, the reducing cutter head comprises a front cutter face, a rear cutter face, a left side face, a right side face and a welding face, a main cutting edge is arranged at the joint of the front cutter face and the rear cutter face, and a retracting front cutter face is arranged at one end of the front cutter face; the left side surface is provided with a retracted left side surface; the end, away from the rear tool face, of the right side face is provided with a retracting right side face. The vertical distance between the indented front cutter faces, the vertical distance between the left side face and the indented left side face and the vertical distance between the right side face and the indented right side face are all delta, and the length of the reducing cutter head is L; when L is less than or equal to 8mm, delta is equal to 0.5 mm; when L is greater than 8mm, delta is equal to 0.8 mm; the saw blade comprises a reducing cutter head and a base body. The saw blade has the beneficial effects that a three-face retraction mode is adopted, the grinding amount of gear grinding machining is remarkably reduced, the contact area of a tool bit and a cut object during cutting of the saw blade is reduced, cutting resistance is reduced, the sharpness of the saw blade is improved, meanwhile, the weight of the tool bit is reduced, and cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of carbide circular saw blades, and in particular to a wear-reducing cutter head and a carbide saw blade. Background Art

[0002] The carbide circular saw blade consists of a circular thin sheet matrix located inside the saw blade and a cutter head uniformly welded to the outer edge of the matrix. Since the cutter head material requires high hardness and high wear resistance, the material is carbide, whose main component is WC, and the bonding phase is mainly metals such as Co and Fe. WC, Co, and Fe are processed into fine powder and fully mixed, and then molded through a pressing process to initially form the shape and size required for the cutter head, and then go through a high temperature furnace and mold pressure sintering process, and finally there are related auxiliary processes to finally produce the cutter head for alloy saw blades.

[0003] After years of development, the blanks of carbide blades have been standardized and serialized. Alloy saw blade manufacturers can select from standard blade blanks according to the cutting objects and specifications of the saw blades. Fig.17 shown.

[0004] The common materials for the base are usually high-quality carbon structural steel and alloy steel sheets. The initial shape and size of the base are formed by stamping or cutting. Evenly distributed chip grooves and expansion joints are set on the outer edge of the base, and a tooth seat adapted to the cutter head is set on one side of the chip groove. The formed base blank is also subjected to heat treatment, inner hole turning, two-plane grinding, stress adjustment and other processes to finally complete the processing of the base.

[0005] In the processing of alloy saw blades, the main processing links are tooth seat grinding, tooth welding, and tooth grinding. There are other auxiliary processes such as leveling, tempering, sand blasting, polishing, stress detection and adjustment, and anti-rust treatment.

[0006] Gear seat grinding is the process of grinding the radial welding surface, circumferential welding surface, and the fillet connecting the gear seat using a special gear seat grinding machine. The purpose is to ensure the accuracy and surface roughness of the gear seat, while also removing the surface oxide scale of the gear seat to create good conditions for brazing the cutter head and the substrate.

[0007] The tooth welding process is to use a special tooth welding machine to braze the cutter head blank to each tooth seat of the base one by one, and the two are connected into a solid whole.

[0008] Gear grinding is the process of using a special alloy saw blade gear grinding machine to grind the front, back, left and right sides of each cutter head blank brazed to the substrate at a set angle, so that the above-mentioned surfaces are correspondingly ground into the rake face, back face, left side and right side of the saw blade. Fig.16 , Fig.17It is the most common alternating tooth type, based on which many other tooth types have been derived.

[0009] The shortcomings of existing alloy saw blade heads: The rake face, left side face, and lower part of the right side face of the cutter head have no beneficial effect on the cutting work. The cutting indicators of the saw blade are sharpness, wear resistance, and cutting quality. The sharpness of the saw blade is determined by the tip and the main cutting edge and the secondary cutting edge. Among each cutting edge, the main cutting edge and the secondary cutting edge near the tooth tip play a more important role. Therefore, the rake face, left side face, and lower part of the right side face of the cutter head have no effect on the sharpness.

[0010] From the wear resistance of the saw blade, the durability depends on the blunting caused by the wear of the tip and cutting edge. The tooth tip and the main cutting edge have no relationship with the rake face, left side, and the lower part of the right side of the cutter head. Only the secondary cutting edge has a theoretical relationship with these three surfaces, but because it is far away from the tip, it can be said that the effect is negligible. Practice has also proved that there is basically no relationship.

[0011] From the perspective of cutting quality, the secondary cutting edge plays a role in leveling the cutting surface, but since the lower end parts of the left and right sides are axially closer to the base than the upper end parts and the axial dimensions are smaller than the upper end parts, they basically have no effect.

[0012] In addition, the front face, left face, and lower end of the right face of the cutter head also rub against the cut part, causing the base temperature of the cutter head and the surrounding area to rise faster, causing a large temperature gradient on the radius of the saw blade. This temperature difference causes a large thermal expansion difference in the base of the saw blade, causing the saw blade to become unstable and deform. At the same time, the friction between the saw blade and the cutting object consumes the energy of the saw blade drive device, reduces the rotation speed of the saw blade, and ultimately leads to a decrease in cutting efficiency, which is manifested as a lower sharpness of the saw blade.

[0013] The reason why this type of cutter head blank is still used in the largest quantity is a continuation of the huge profits in the early days of the carbide saw blade industry. At one time, the large cutter head was even a selling point. Now it has become a consensus that the large cutter head has no effect on the saw blade. Therefore, reducing the friction between the cutter head and the cut object and reducing the heat of the saw blade as much as possible have become technical problems to be solved.

[0014] In the existing patent, the application number is 201921462577.9, and the name is a kind of alloy circular saw blade with scraper, which discloses a circular saw blade body, the surface of which is provided with cutting teeth, the top and bottom of which are provided with drainage grooves, the left side of the inner wall of which is provided with a mounting groove, and the interior of which is provided with a scraper; the scraper is provided on the saw blade, which increases the contact area between the saw blade and the object to be cut, and easily causes the saw blade to become unstable and deformed, while reducing the strength of the matrix; The application number is 202110359340.3; the name is a carbide circular saw blade, including a saw blade body and a cutter head, and tooth-like protrusions are evenly distributed on the outer edge of the saw blade body, and a cutter head seat is provided on the upper part of each tooth-like protrusion, and the side of the cutter head seat is a side end wall, and the side end wall and the cutter head are in contact in the thickness direction of the saw blade body and are arranged side by side, and the side end wall and the cutter head are fixed together by screws; the cutter head is fixed to the tooth seat of the base by screws, which reduces the strength of the tooth seat on the base, and the tooth seat is more prone to breakage. Summary of the invention

[0015] The purpose of the invention of this application is to provide a wear-reducing cutter head and a carbide saw blade, which can reduce the processing volume of the gear grinding process, improve processing efficiency, reduce power consumption and gear grinding diamond grinding wheel consumption without affecting the cutting performance of the carbide circular saw blade and without changing any processing process; and reduce the friction between the cutter head and the cutting object during the final saw blade cutting process, making the cutting work easier and reducing the probability of the saw blade being deformed due to heat; and reduce the consumption of carbide materials.

[0016] To achieve the above objectives, this application adopts the following technical solutions: A wear-reducing tool head comprises a rake face, a flank face, a left side face, a right side face and a welding face, wherein the intersection of the rake face and the flank face is a main cutting edge, an indented rake face is provided at one end of the rake face away from the main cutting edge; an indented left side face is provided at one end of the left side face away from the flank face; and an indented right side face is provided at one end of the right side face away from the flank face.

[0017] Further, the vertical distance between the indented rake face and the rake face, the vertical distance between the left side face and the indented left side face, and the vertical distance between the right side face and the indented right side face are all δ, and the length of the grinding head is L; When L≤8mm, δ=0.5mm; When L>8㎜,δ=0.8㎜.

[0018] Furthermore, a transition chamfer λ is provided at the connection between the indented rake face and the rake face, at the connection between the left side face and the indented left side face, and at the connection between the right side face and the indented right side face, and the range is 30°≤λ≤60°.

[0019] Furthermore, transition fillets R1 are provided at the connection between the indented rake faces, the connection between the left side face and the indented left side face, and the connection between the right side face and the indented right side face, and the radius of the fillet R1 is 0.5 mm to 1 mm.

[0020] Furthermore, the lengths of the front cutting edge, the left side and the right side are all L3. When L≤8㎜, 2㎜≤L3≤3㎜; When L>8㎜, 3㎜≤L3≤4㎜.

[0021] Furthermore, the welding surface includes a radial welding surface and a circumferential welding surface; the radial welding surface and the circumferential welding surface are transitioned through an arc surface.

[0022] A cemented carbide saw blade also includes a substrate, a wear-reducing cutter head brazed on a tooth seat of the substrate; the width of the circumferential welding surface is equal to the thickness of the substrate; the width of the radial welding surface after being cut off by the indented left side and the indented right side is equal to the thickness of the substrate.

[0023] The beneficial effects of this application are: The cutter head of the present application adopts a method of reducing the height and thickness of the front cutting face, the left side face and the right side face which are not involved in cutting and are far from the main cutting edge, so as to reduce the weight of the cutter head and thus reduce the cost. It can also reduce the resistance between the three faces and the object to be cut when the saw blade is used, and reduce the probability of the saw blade becoming unstable and deforming due to heat. At the same time, when manufacturing the saw blade, because the area to be ground on the three faces becomes smaller, the consumption of the grinding wheel for grinding teeth can also be reduced, further reducing the manufacturing cost. By setting chamfers or fillets between the rake face, the left face, the right face and their indentation faces, stress concentration caused by right-angle connection can be avoided; By setting the width of the circumferential welding surface and the radial welding surface to be the same as the thickness of the substrate, it is avoided that the welding strength is reduced after the indentation surface is set. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the three-dimensional structure of the wear-reducing cutter head; Figure 2 A schematic diagram showing the three-dimensional structure of the wear-reducing cutter head on the right side; Figure 3 A schematic diagram showing the three-dimensional structure of the wear-reducing cutter head on the welding surface; Figure 4 This is the front view of the grinding head; Figure 5 This is the left side view of the grinding head; Figure 6 for Figure 4 FF section view; Figure 7 for Figure 4 Cross-sectional view at GG; Figure 8 This is the front view of the grinding cutter head blank; Fig. 9 for Figure 8 Sectional view at AA; Fig.10 It is a structural schematic diagram of a carbide saw blade; Fig.11 for Fig.10 The enlarged view of point Ⅰ; Fig.12 for Fig.11 Sectional view at CC of ; Fig.13 for Fig.11 Sectional view at NN of ; Fig.14 for Fig.10 EE section view; Fig.15 for Fig.14 The enlarged view of point II; Fig.16 It is a schematic diagram of a partial three-dimensional structure of a carbide saw blade; Fig.17 This is a schematic diagram of the structure of the cutter head before improvement; The numbers in the figure are 1-cutter head, 11-flank face, 12-front face, 13-left side, 14-right side, 15-radial welding face, 16-circumferential welding face; 111-main cutting edge, 112-tool tip; 121-indented front cutting edge, 131-indented left side, 141-indented right side; 2-Matrix. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application; the described embodiments are only part of the embodiments of the present application, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments in the present application shall fall within the scope of protection of the present application; Example 1

[0026] like Figure 1 —17, like Figure 1-3 As shown, the wear-reducing cutter head is a hexahedral structure, which includes a back cutting edge 11, a front cutting edge 12, a left side 13, a right side 14 and a welding surface, and the welding surface includes a radial welding surface 15 and a circumferential welding surface 16; a circular chamfer R transition is provided between the radial welding surface 15 and the circumferential welding surface 16; the radius of the circular chamfer R is 0.5 mm.

[0027] The junction of the rear cutting edge 11 and the front cutting edge 12 is the main cutting edge 111, which is responsible for the cutting work of the saw blade; The main cutting edge 111 is a straight line inclined upward, and its highest point is the blade tip 112; the blade tip 112 contacts the object to be cut first; An end of the rake face 12 away from the main cutting edge 111 is provided with a retracted rake face 121; An end of the left side surface 13 away from the flank surface 11 is provided with an indented left side surface 131; An end of the right side surface 14 away from the back cutting surface 11 is provided with a retracted right side surface 141 .

[0028] Each indentation surface is parallel to the original blade surface, and the distance between each indentation surface and the original blade surface is δ; That is, the vertical distance between the indented rake face 121 and the rake face 12, the vertical distance between the left side face 13 and the indented left side face 131, and the vertical distance between the right side face 14 and the indented right side face 141 are all δ, and the length of the grinding head is L; When L≤8mm, δ=0.5mm; When L>8㎜,δ=0.8㎜.

[0029] Generally speaking, the larger the diameter of the saw blade, the longer the cutter head is, and the thicker the cutter head is, so the value of δ is also larger; the value of δ is also related to the width W of the cutter head and the thickness B1 of the substrate. Since the cutter head 1 is symmetrical in the thickness direction of the substrate 2, the width W1 of the left and right sides of the cutter head 1 after indentation should not be less than the thickness B1 of the substrate, so as to avoid reducing the welding surface and reducing the welding strength; A transition chamfer λ is provided at the connection between the indented rake face 121 and the rake face 12 , at the connection between the left side face 13 and the indented left side face 131 , and at the connection between the right side face 14 and the indented right side face 141 ; The range of transition chamfer is 30°≤λ≤60°. The smaller the angle is, the easier it is to demold when making the cutter head blank, but the cutter head will be heavier, which is not conducive to reducing costs; the larger the angle is, the more likely it is to have a dead angle, causing stress concentration and reducing the life of the mold.

[0030] The lengths of the front cutting edge 12, the left side 13 and the right side 14 are all L3. When L≤8㎜, 2㎜≤L3≤3㎜; When L>8㎜, 3㎜≤L3≤4㎜.

[0031] The longer the length L3 of the front cutting edge 12, the left side 13 and the right side 14, the larger the contact area between the saw blade and the object being cut, the greater the resistance, which is not conducive to reducing friction; if it is too small, the strength of the cutter head will be reduced, resulting in the risk of tooth breakage during cutting.

[0032] like Figure 8As shown, a chamfer is set between the indented front cutting edge 121 and the circumferential welding surface 16, the chamfer angle is η, the chamfer length is L2, and L2 is generally 2 mm; in order to reduce the weight of the cutter head and reduce the cost; the chamfer cannot reduce the welding length of the circumferential welding surface 16 on the substrate 2; By setting three indentation surfaces, the friction surface between the object to be cut and the cutter head is reduced during cutting, so as to avoid the cutter head heating and causing deformation of the substrate.

[0033] The setting of the indentation distance δ and the distance between the upper edge of each chamfer and the top surface of the original cutter head as L3 is to ensure that the tip and the main and secondary cutting edges of the product cutter head after grinding have sufficient strength and adapt to all angles of the general cutter head to ensure good adaptability. The setting of the indentation distance δ also ensures that after the three sides are indented, the width of the lower welding surface of the cutter head is not less than the thickness of the substrate, thereby ensuring that the welding area is not affected, and ultimately ensuring the welding strength between the cutter head and the substrate; Example 2

[0034] The structure of this embodiment is basically the same as that of embodiment 1. The difference is that like Figure 8-9 As shown, A transition fillet R1 is provided at the connection between the indented front cutting edge 121 and the front cutting edge 12 , the connection between the left side surface 13 and the indented left side surface 131 , and the connection between the right side surface 14 and the indented right side surface 141 . The radius of the fillet R1 is 0.5 mm to 1 mm.

[0035] The smaller the radius of fillet R1, the more difficult it is to demold during production, and the shorter the life of the mold; the larger the radius, the easier it is to demold during production, but the weight of the cutter head will be heavier; the optimal value we give is 0.8mm, which takes into account both mold life and cutter head weight reduction.

[0036] A width of 0.2 mm is left at the main cutting edge 111 of the rake face 12 and the flank face 11 of the blank so that the completed main cutting edge 111 can be machined during gear grinding.

[0037] The transition surfaces between the front, left and right sides of the blank and their corresponding indented surfaces are improved to rounded corners, which is helpful to alleviate the stress concentration phenomenon here. Since the components of the cutter head and the substrate are very different in the cutter head welding process, the thermal stress generated during the cooling process after welding is large, and the cutter head is often affected by the thermal stress to produce cracks or even breakage, so it is necessary to improve the transition to rounded corners here; Example 3

[0038] The structure of this embodiment is basically the same as that of embodiment 1. The difference is that like Figure 10-17 As shown, A cemented carbide saw blade also includes a substrate 2, a wear-reducing cutter head 1 brazed on a tooth seat of the substrate 2; the width of a circumferential welding surface 16 is equal to a thickness B1 of the substrate 2; the width of a radial welding surface 15 after being cut off by the indented left side 131 and the indented right side 141 is equal to the thickness of the substrate 2.

[0039] like Fig.14 As shown, the thickness of the grinding head 1 of the saw blade after grinding is T', α is the front angle of the head, the larger the angle, the sharper the head, but the life will be reduced, so this application combines work experience to take into account both life and sharpness and is set to 65 degrees.

[0040] like Figure 8 As shown, the thickness of the cutter head blank before grinding is T, and T-T' is the grinding thickness in this direction, that is, the machining allowance, which needs to be processed by a grinder.

[0041] The indentation structure of the present application greatly reduces the grinding workload of the gear grinding process. Among all the processing processes of the entire alloy saw blade, the gear grinding process has the lowest efficiency. To a certain extent, improving the efficiency of gear grinding is to improve the production efficiency of the alloy saw blade.

[0042] Taking the 305×40T alloy saw blade for wood with the least number of teeth and the highest grinding efficiency as an example, each set of gear grinding equipment can only process 145 pieces of products per shift. Each set of equipment includes: 1 front face gear grinding machine (double grinding head) + 3 side face gear grinding machines (double grinding heads) + 2 back face gear grinding machines (single grinding head).

[0043] The parameters of the improved front cutter head blank are as follows (mm):

[0044] The grinding area of ​​the rake face 12 and the two side faces is: 2×22.13m 2 +19.6m 2 =63.86m 2 ; The density of the blade material is: 14.65g / cm 3 , the mass of a single cutter head is: 1.1385885g.

[0045] The parameters of the cutter head blank after the application is improved are as follows (mm):

[0046] The grinding area of ​​the front cutting face 12, the left side face 13 and the right side face 14 of the improved cutter head 1 blank is: 2×8.74m 2 +8.75m 2 =26.23m 2 ; The density of the material of the grinding head 1 is: 14.65g / cm 3 , the mass of a single grinding head 1 is: 0.90503305g.

[0047] Because the grinding thickness allowance remains unchanged, by adopting the tool head blank of the present application, the grinding amount becomes 41% of the original amount, and the grinding amount is reduced by 58.9%.

[0048] The reduction in grinding volume not only improves processing efficiency, but also proportionally reduces the consumption of diamond grinding wheels and electricity for grinding teeth, which will undoubtedly have a huge effect on reducing the cost of carbide saw blades.

[0049] While reducing the amount of grinding, the quality of the cutter head blank becomes 79.5% of the original, that is, the amount is reduced by 20.5%. The cutter head blank is priced by weight when purchased, and the purchase cost of a single cutter head is reduced by 20.5%.

[0050] The cutter head blank of the present application has a simple structure, and in the manufacturing process of the cutter head blank, it provides convenience for the processing and manufacturing of the steel mold for the pressing process and the graphite mold for the sintering process. Both the horizontal pressing and vertical pressing modes can be demolded smoothly, and the life of the processing mold of the cutter head blank is effectively guaranteed.

[0051] Since the angle range of the back edge angle is relatively large and is evenly distributed in the range of 0°-20°, if the back tool face 11 is set with a retracted amount, the back tool face 11 will lack material and cannot be ground into a complete back tool face 11, so the back tool face 11 is not set with a telescopic surface.

[0052] The above is only a preferred specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed in the present application according to the technical solution and improved ideas of the present application, which should be covered by the protection scope of the present application.

[0053] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

Claims

1. A wear-reducing tool head, comprising a rake face (12), a flank face (11), a left side face (13), a right side face (14) and a welding face, wherein the intersection of the rake face (12) and the flank face (11) is a main cutting edge (111), characterized in that: An end of the front cutting surface (12) away from the main cutting edge (111) is provided with an indented front cutting surface (121); an end of the left side surface (13) away from the back cutting surface (11) is provided with an indented left side surface (131); and an end of the right side surface (14) away from the back cutting surface (11) is provided with an indented right side surface (141).

2. A wear-reducing cutter head according to claim 1, characterized in that: The vertical distance between the indented front cutting edge (121) and the front cutting edge (12), the vertical distance between the left side surface (13) and the indented left side surface (131), and the vertical distance between the right side surface (14) and the indented right side surface (141) are all δ, and the length of the grinding head is L; When L≤8mm, δ=0.5mm; When L>8㎜,δ=0.8㎜.

3. A wear-reducing cutter head according to claim 2, characterized in that: A transition chamfer λ is provided at the connection between the indented front cutting edge (121) and the front cutting edge (12), at the connection between the left side surface (13) and the indented left side surface (131), and at the connection between the right side surface (14) and the indented right side surface (141), with a range of 30°≤λ≤60°.

4. The wear-reducing cutter head according to claim 2, characterized in that: A transition fillet R1 is provided at the connection between the indented front cutting edge (121) and the front cutting edge (12), at the connection between the left side surface (13) and the indented left side surface (131), and at the connection between the right side surface (14) and the indented right side surface (141), and the radius of the fillet R1 is 0.5 mm to 1 mm.

5. A wear-reducing cutter head according to claim 3 or 4, characterized in that: The lengths of the front cutting edge (12), the left side (13) and the right side (14) are all L3. When L≤8㎜, 2㎜≤L3≤3㎜; When L>8㎜, 3㎜≤L3≤4㎜.

6. The wear-reducing cutter head according to claim 5, characterized in that: The welding surface comprises a radial welding surface (15) and a circumferential welding surface (16); the radial welding surface (15) and the circumferential welding surface (16) are transitioned via an arc surface.

7. A cemented carbide saw blade, using a wear-reducing cutter head according to claim 6, characterized in that: It also includes a base (2), a wear-reducing cutter head (1) brazed on a tooth seat of the base (2); the width of the circumferential welding surface (16) is equal to the thickness of the base (2); and the width of the radial welding surface (15) left after being cut off by the indented left side surface (131) and the indented right side surface (141) is equal to the thickness of the base (2).

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