Preparation method of a compound planer tool with a matching cover tooth pattern

Abstract

A preparation method of a compound planer tool with a covering tooth pattern, which relates to the technical field of compound tool manufacturing. The purpose of the present invention is to solve the problems that the wood planer tool manufactured by the existing method has obvious welding stress due to the large difference in the linear expansion coefficients of cemented carbide and low-carbon steel, resulting in deformation after welding, and it is difficult to control the accuracy and the assembly positioning is poor during the process of machining the wood planer tool. In the present invention, two grooves are symmetrically opened on the left and right of the center line of the low-carbon steel tool body, and cemented carbide cutting edges with the same size are placed in the grooves. Further, a method of simultaneously welding two cemented carbide blades to a carbon steel tool bar is adopted. By using the characteristic that the deformations of the two cemented carbide blades are opposite to each other, the overall deformation of the tool is offset mutually, the residual stress of the tool is effectively relieved, the probability of cracks appearing in the welded joint is reduced, the purpose of improving the strength of the welded joint is achieved, and the service life of the tool is prolonged. The present invention can obtain a preparation method of a compound planer tool with a covering tooth pattern.

Description

Technical Field

[0001] The present invention relates to the technical field of composite tool manufacturing, and particularly relates to a preparation method of a cover-tooth-thread composite planer tool. Background Art

[0002] Cemented carbide is a powder metallurgy material sintered from refractory particles such as WC and binders such as Co. It has a quite high hardness and very good red hardness, can withstand cutting temperatures up to 800 - 1000 °C, and is not easily deformed. It has now become the main material for preparing woodworking cutting tools and cutting edges. The traditional welded large cemented carbide woodworking planer tool is a commonly used tool in wood carving, thinning, and cutting processes. Its cutting edge material is mostly cemented carbide, and the tool body material is low-carbon steel. There are two key problems in the manufacture of welded large cemented carbide woodworking planer tools. The first problem is the welding stress problem between cemented carbide and low-carbon steel. Since the linear expansion coefficient of cemented carbide is (4 - 7)×10 -6 , while the linear expansion coefficient of carbon steel is (14.7 - 15)×10 -6 , it can be seen that the linear expansion coefficients of cemented carbide and carbon steel differ by about 2 - 3 times. Therefore, after the thermal cycle of welding, the shrinkage of cemented carbide is more than half less than that of steel. However, in fact, after the cemented carbide blade is welded to the carbon steel tool bar, they are firmly connected through the weld. The free shrinkage between the blade and the tool bar is restricted. As a result, the carbon steel with a larger linear expansion coefficient generates tensile stress near the weld, while the cemented carbide with a smaller linear expansion coefficient generates compressive stress at the weld. The combined action of tensile stress and compressive stress will surely cause the deformation of cemented carbide and carbon steel, and the longer the tool, the more obvious the deformation. Seriously, it will cause failure behaviors such as cracks or even fractures on the cemented carbide blade.

[0003] The second problem is the poor assembly and positioning accuracy of the woodworking planer tool. Since the woodworking planer tool mainly relies on its cutting edge for work, and the cutting edge of a large woodworking planer tool is a vulnerable part, its cutting edge wears very fast. Under normal circumstances, the woodworking planer tool can be disassembled, and its service life can be extended by regrinding or sharpening the cutting edge and then reinstalling it. However, the length of the woodworking planer tool is usually greater than 1 m, and the width is greater than 30 cm. It is long in size and heavy in weight. After regrinding and installing, the processing position will change and requires repositioning, resulting in an extended processing time. At the same time, it will also affect the processing accuracy, and the processed dimensions will deviate. So far, there is no method suitable for the rapid installation and positioning processing of large woodworking planer tools or a precision processing tool that can be quickly disassembled and installed. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a cover-tooth-thread composite planer tool to solve the problems that the woodworking planer tool manufactured by the existing method has obvious welding stress due to the large difference in linear expansion coefficients between cemented carbide and low-carbon steel, resulting in deformation after welding, and it is difficult to control the accuracy and the assembly and positioning are poor during the process of processing the woodworking planer tool.

[0005] A preparation method of a compound planer tool with a matching cover tooth pattern is carried out according to the following steps:

[0006] Step 1: Taking the center line 4 in the length direction of the bottom surface of the low-carbon steel tool body 2 as the reference, two grooves are symmetrically opened on the left and right sides of the middle line 4. At the same time, two hard alloy cutting edges 1 are processed, and the size of the hard alloy strip is the same as that of the groove. Then, the welding surfaces to be welded of the groove and the hard alloy cutting edge 1 are cleaned.

[0007] Step 2: The welding surfaces to be welded of the hard alloy cutting edge 1 and the groove of the low-carbon steel tool body 2 are evenly coated with nickel-based brazing paste. Then, the hard alloy cutting edge 1 is placed into the groove of the low-carbon steel tool body 2 to obtain a structural member to be welded. The structural member to be welded is installed on a fixture and then placed in a vacuum brazing furnace. It is kept warm for 20 - 40 min under the vacuum degree of 1 - 6×10 -2 Pa and the temperature condition of 1300 - 1350 °C. After the heat preservation is completed, it is cooled to room temperature to obtain a brazed structural member.

[0008] Step 3: Under the protection of inert gas, the brazed structural member is reheated to 1100 - 1220 °C and kept warm for 0.5 - 1 h at 1100 - 1220 °C. After the heat preservation is completed, it is first cooled to 850 - 960 °C, then cooled to room temperature, and then tempered for 1.5 - 2 h at the temperature condition of 350 - 450 °C to obtain a welded part after tempering.

[0009] Step 4: The welded part after tempering is cut into two parts along the center line 4 and processed into shape respectively to obtain two tools. The tool is ground with a tooth pattern of 87° - 93° on the other side brazed with the hard alloy cutting edge 1, and the ground tool is used as the lower cover of the compound planer tool.

[0010] Step 5: Take a high-speed steel plate 3, grind a tooth pattern of 87° - 93° on one side of the high-speed steel plate 3 and a tooth pattern of 57° - 63° on the other side. The ground high-speed steel plate 3 is used as the upper cover of the compound planer tool. Finally, the side of the high-speed steel ground with a tooth pattern of 87° - 93° is assembled with the side of the tool ground with a tooth pattern of 87° - 93° in a tooth pattern meshing manner to obtain a compound planer tool with a matching cover tooth pattern.

[0011] The beneficial effects of the present invention:

[0012] (1) In the present invention, two grooves are symmetrically opened on the left and right sides of the center line of the low-carbon steel tool body, and hard alloy cutting edges with the same size are placed in the grooves. Further, by using the method of simultaneously welding two hard alloy blades and a carbon steel tool bar, taking advantage of the characteristics that the deformations of the two hard alloy blades are opposite to each other, the overall deformation of the tool is offset mutually, effectively relieving the residual stress of the tool, reducing the probability of cracks appearing in the welded joint, achieving the purpose of improving the strength of the welded joint, and prolonging the service life of the tool.

[0013] (2) The cover - matching tooth - grooved composite planer tool of the present invention has a carbide cutting edge material, which has high red - hardness, high hardness, wear - resistance, long service life, sharp and non - deformed cutting edges, and high quality and precision of the processed products. During the use process, it does not need to frequently repair the tool or grind the cutting edge; the tool body material is low - carbon steel with good toughness; the cover - matching tool body is high - speed steel with high hardness; the combination of the three can significantly improve the service life of the composite planer tool.

[0014] (3) For the cover - matching tooth - grooved composite planer tool of the present invention, the high - speed steel is used as the upper cover of the tool, and the low - carbon steel tool body is used as the lower cover. Small - angle precision teeth with equal distances are ground on the upper plane of the high - speed steel, and large - angle precision teeth with equal distances are ground on its lower plane; large - angle precision teeth with equal distances are ground on the upper plane of the low - carbon steel tool body; the small - angle precision teeth of the high - speed steel upper cover are suitable for quick assembly and fixation, and its large - angle precision teeth on the lower plane can match the large - angle precision teeth of the low - carbon steel tool bar to form a high - precision and equal - distance combined cover - matching ground - tooth planer tool. The high - speed steel upper cover and the low - carbon steel tool body lower cover are assembled together to form a cover - matching tooth - grooved composite planer tool. Since the tooth - groove spacing is fixed, rapid positioning can be achieved using the tooth grooves during installation and positioning, realizing rapid and precise installation.

[0015] The present invention can obtain a preparation method for a cover - matching tooth - grooved composite planer tool. Brief Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the welding and assembly of a low - carbon steel tool body and a carbide cutting edge. 1 represents the carbide cutting edge, 2 represents the low - carbon steel tool body, and 4 represents the center line;

[0017] Figure 2 It is a schematic diagram of the assembly of the cover - matching tooth - grooved composite planer tool. 1 represents the carbide cutting edge, 2 represents the low - carbon steel tool body, and 3 represents the high - speed steel plate. Detailed Description of the Invention

[0018] Detailed Description of Embodiment 1: A preparation method for a cover - matching tooth - grooved composite planer tool in this embodiment is carried out according to the following steps:

[0019] Step 1: Taking the center line 4 in the length direction of the bottom surface of the low - carbon steel tool body 2 as the reference, two grooves are symmetrically opened on the left and right sides of the middle line 4. At the same time, two carbide cutting edges 1 are processed, and the dimensions of the carbide strips are the same as those of the grooves; then the welding surfaces of the grooves and the carbide cutting edges 1 are cleaned;

[0020] Step 2: Evenly coat the nickel - based brazing paste on the welding surfaces of the carbide cutting edges 1 and the grooves of the low - carbon steel tool body 2. Then put the carbide cutting edges 1 into the grooves of the low - carbon steel tool body 2 to obtain a structure to be welded; install the structure to be welded on the fixture, and then place it in a vacuum brazing furnace. At 1 - 6×10 -2Under a vacuum degree of Pa and a temperature condition of 1300 - 1350 °C, keep warm for 20 - 40 min. After the heat preservation ends, cool to room temperature to obtain the brazed structural part;

[0021] Step three: Under the protection of inert gas, reheat the brazed structural part to 1100 - 1220 °C, and keep warm at 1100 - 1220 °C for 0.5 - 1 h. After the heat preservation ends, first cool down to 850 - 960 °C, then cool to room temperature, and then temper at a temperature condition of 350 - 450 °C for 1.5 - 2 h to obtain the welded part after tempering;

[0022] Step four: Cut the welded part after tempering into two parts along the center line 4, and process them into shape respectively to obtain two cutters; Grind tooth patterns with an angle of 87° - 93° on the other side of the cutter where the cemented carbide cutting edge 1 is brazed. Take the ground cutter as the lower cover of the composite planer;

[0023] Step five: Take a high - speed steel plate 3, grind tooth patterns with an angle of 87° - 93° on one side and grind tooth patterns with an angle of 57° - 63° on the other side. Take the ground high - speed steel plate 3 as the upper cover of the composite planer; Finally, assemble the side with 87° - 93° tooth patterns on the high - speed steel with the side with 87° - 93° tooth patterns on the cutter in a way that the tooth patterns are engaged to obtain the composite planer with matching cover tooth patterns.

[0024] Specific implementation method two: The difference between this implementation method and the first specific implementation method is: In step one, the width of the groove on the bottom surface of the low - carbon steel cutter body 2 is 10 - 50 mm, and the depth is 0.4 - 1.5 mm; In step one, the width of the cemented carbide cutting edge 1 is 10 - 50 mm, and the thickness is 0.4 - 1.6 mm.

[0025] Other steps are the same as those in the first specific implementation method.

[0026] Specific implementation method three: The difference between this implementation method and the first or second specific implementation method is: In step one, remove surface burrs, oxide layers, and oil stains from the welding surfaces of the groove and the cemented carbide strip.

[0027] Other steps are the same as those in the first or second specific implementation method.

[0028] Specific implementation method four: The difference between this implementation method and any one of the first to third specific implementation methods is: The nickel - based solder paste in step two is BNi2 solder paste, and the fixture is a graphite fixture.

[0029] Other steps are the same as those in the first to third specific implementation methods.

[0030] Specific implementation method five: The difference between this implementation method and any one of the first to fourth specific implementation methods is: In step two, heat up to 1300 - 1350 °C at a heating rate of 5 - 10 °C / min.

[0031] The other steps are the same as those in the first to fourth specific embodiments.

[0032] Specific embodiment six: The difference between this embodiment and any one of the first to fifth specific embodiments is that: in step three, the inert gas is nitrogen or argon, and the gas inlet pressure is 21 - 23 bar.

[0033] The other steps are the same as those in the first to fifth specific embodiments.

[0034] Specific embodiment seven: The difference between this embodiment and any one of the first to sixth specific embodiments is that: in step three, first cool down to 850 - 960 °C at a cooling rate of 50 - 90 °C / min, and then cool down to room temperature at a cooling rate of 15 - 25 °C / min.

[0035] The other steps are the same as those in the first to sixth specific embodiments.

[0036] Specific embodiment eight: The difference between this embodiment and any one of the first to seventh specific embodiments is that: in step three, temper 3 - 5 times within 1.5 - 2 h.

[0037] The other steps are the same as those in the first to seventh specific embodiments.

[0038] Specific embodiment nine: The difference between this embodiment and any one of the first to eighth specific embodiments is that: in step four, the width of the ground tool is 100 - 300 mm, the thickness is 3.1 - 13.3 mm, and the tolerance is 0.03 - 0.07 mm.

[0039] The other steps are the same as those in the first to eighth specific embodiments.

[0040] Specific embodiment ten: The difference between this embodiment and any one of the first to ninth specific embodiments is that: in step five, the thickness of the ground high-speed steel plate 3 is 7.9 - 18.7 mm, the surface roughness is Ra0.8 - Ra1.0; the tooth pitches of the 87° - 93° tooth pattern and the 57° - 63° tooth pattern are both 1.5 - 1.6 mm, and the tooth depth of the 57° - 63° tooth pattern is 0.80 - 0.90 mm; the total thickness of the cover tooth pattern composite planer is 11 - 32 mm.

[0041] The other steps are the same as those in the first to ninth specific embodiments.

[0042] The following examples are used to verify the beneficial effects of the present invention:

[0043] Example 1: A preparation method of a cover tooth pattern composite planer is carried out according to the following steps:

[0044] Step 1: Taking the center line 4 in the length direction of the bottom surface of the low-carbon steel tool body 2 as the reference, two grooves are symmetrically opened on the left and right sides of the center line 4. At the same time, two cemented carbide cutting edges 1 are processed, and the size of the cemented carbide strip is the same as that of the groove. Then, the welding surfaces of the groove and the cemented carbide cutting edge 1 are cleaned;

[0045] The type of the cemented carbide is WC-30Co cemented carbide, and the low-carbon steel is No. 20 low-carbon steel;

[0046] Step 2: The welding surfaces of the cemented carbide cutting edge 1 and the groove of the low-carbon steel tool body 2 are evenly coated with nickel-based brazing paste. Then, the cemented carbide cutting edge 1 is placed into the groove of the low-carbon steel tool body 2 to obtain a structure to be welded. The structure to be welded is installed on a fixture and then placed in a vacuum brazing furnace. It is kept warm for 40 min under the vacuum degree of 4×10 -2 Pa and the temperature of 1340 °C. After the heat preservation is completed, it is cooled to room temperature to obtain a brazed structure;

[0047] Step 3: Under the protection of inert gas, the brazed structure is reheated to 1200 °C and kept warm at 1200 °C for 1 h. After the heat preservation is completed, it is first cooled to 910 °C and then cooled to room temperature. Then, it is tempered at 415 °C for 1.5 h to obtain a welded part after tempering;

[0048] Step 4: The welded part after tempering is cut into two parts along the center line 4 and processed into shape respectively to obtain two tools. The teeth with an angle of 91° are ground on the other side of the tool where the cemented carbide cutting edge 1 is brazed. The tool after grinding is used as the lower cover of the composite planer;

[0049] Step 5: A high-speed steel plate 3 is taken. The teeth with an angle of 91° are ground on one side of the high-speed steel plate 3, and the teeth with an angle of 59° are ground on the other side. The high-speed steel plate 3 after grinding is used as the upper cover of the composite planer. Finally, the side of the high-speed steel with the 91° teeth ground is assembled with the side of the tool with the 91° teeth ground in a way that the teeth are meshed to obtain a composite planer with matching cover teeth.

Claims

1. A preparation method of a compound planer tool with matching cover tooth patterns, characterized in that The preparation method is carried out according to the following steps: Step 1: Taking the center line (4) in the length direction of the bottom surface of the low-carbon steel tool body (2) as the reference, two grooves are symmetrically opened on the left and right of the center line (4), and two cemented carbide cutting edges (1) are processed at the same time, and the size of the cemented carbide strip is the same as that of the groove; then the welding surfaces of the groove and the cemented carbide cutting edge (1) are cleaned. Step 2: Uniformly coat the nickel-based solder paste on the welding surfaces to be welded of the carbide cutting edge (1) and the groove of the low-carbon steel tool body (2). Then, place the carbide cutting edge (1) into the groove of the low-carbon steel tool body (2) to obtain the structural member to be welded. Install the structural member to be welded on the fixture, and then place it in a vacuum brazing furnace. Keep it warm for 20 - 40 min under the vacuum degree of 1 - 6×10 -2 Pa and the temperature condition of 1300 - 1350 °C. After the heat preservation is completed, cool it to room temperature to obtain the brazed structural member; Step 3: Under the protection of inert gas, the brazed structural part is reheated to 1100 - 1220 °C, and kept warm at 1100 - 1220 °C for 0.5 - 1 h. After the heat preservation is completed, it is first cooled to 850 - 960 °C, then cooled to room temperature, and then tempered at 350 - 450 °C for 1.5 - 2 h to obtain the welded part after tempering. Step 4: The welded part after tempering is cut into two parts along the center line (4) and processed into shape respectively to obtain two tools; the teeth with an angle of 87° - 93° are ground on the other side of the tool brazed with the cemented carbide cutting edge (1), and the tool after grinding is used as the lower cover of the composite planer. Step 5: Take a high-speed steel plate (3), grind the teeth with an angle of 87° - 93° on one side of the high-speed steel plate (3), and grind the teeth with an angle of 57° - 63° on the other side. The high-speed steel plate (3) after grinding is used as the upper cover of the composite planer; finally, the side of the high-speed steel with the teeth of 87° - 93° ground on it is assembled with the side of the tool with the teeth of 87° - 93° ground on it in a way that the teeth are engaged to obtain the composite planer with matching cover teeth.

2. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1, characterized in that In Step 1, the width of the groove on the bottom surface of the low-carbon steel tool body (2) is 10 - 50 mm, and the depth is 0.4 - 1.5 mm; in Step 1, the width of the cemented carbide cutting edge (1) is 10 - 50 mm, and the thickness is 0.4 - 1.6 mm.

3. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1 or 2, characterized in that In Step 1, the surface burrs, oxide layers and oil stains are removed from the welding surfaces of the groove and the cemented carbide strip.

4. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1, characterized in that In Step 2, the nickel-based brazing paste is BNi2 brazing paste, and the fixture is a graphite fixture.

5. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1, characterized in that In Step 2, the temperature is raised to 1300 - 1350 °C at a heating rate of 5 - 10 °C / min.

6. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1, characterized in that In Step 3, the inert gas is nitrogen or argon, and the gas inlet pressure is 21 - 23 bar.

7. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1, characterized in that In Step 3, it is first cooled to 850 - 960 °C at a cooling rate of 50 - 90 °C / min, and then cooled to room temperature at a cooling rate of 15 - 25 °C / min.

8. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1, characterized in that In Step 3, tempering is carried out 3 - 5 times within 1.5 - 2 h.

9. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1, characterized in that In Step 4, the width of the tool after grinding is 100 - 300 mm, the thickness is 3.1 - 13.3 mm, and the tolerance is 0.03 - 0.07 mm.

10. The preparation method of a matching cover tooth pattern composite planer tool according to claim 1, characterized in that In Step 5, the thickness of the high-speed steel plate (3) after grinding is 7.9 - 18.7 mm, and the surface roughness is Ra0.8 - Ra1.0; the tooth pitches of the teeth with an angle of 87° - 93° and the teeth with an angle of 57° - 63° are both 1.5 - 1.6 mm, and the tooth depth of the teeth with an angle of 57° - 63° is 0.80 - 0.90 mm; the total thickness of the composite planer with matching cover teeth is 11 - 32 mm.

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