CN108044202B - Hob for processing screw rotor and its production method - Google Patents
Hob for processing screw rotor and its production method Download PDFInfo
- Publication number
- CN108044202B CN108044202B CN201711263045.8A CN201711263045A CN108044202B CN 108044202 B CN108044202 B CN 108044202B CN 201711263045 A CN201711263045 A CN 201711263045A CN 108044202 B CN108044202 B CN 108044202B
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- hob
- rotor
- tooth
- cutter
- rotor hob
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- 238000000227 grinding Methods 0.000 claims abstract description 79
- 238000000034 method Methods 0.000 claims abstract description 14
- 238000003754 machining Methods 0.000 claims abstract description 9
- 238000003801 milling Methods 0.000 claims description 18
- 238000005520 cutting process Methods 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 6
- 238000003672 processing method Methods 0.000 claims description 6
- 238000005553 drilling Methods 0.000 claims description 3
- 238000005242 forging Methods 0.000 claims description 3
- 238000009966 trimming Methods 0.000 claims description 2
- 238000001514 detection method Methods 0.000 description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000010431 corundum Substances 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 238000007730 finishing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Abstract
A hob for processing screw rotor and its production method, including the cutter body with inner hole and pillow block, there are cutter teeth on the cutter body uniformly, the chip pocket between the cutter teeth is parallel with axis of the cutter body, the cutter teeth are arranged along the circumference of the cutter body spirally; the cutter body has two pairs, one pair is a female rotor hob and the other pair is a male rotor hob; the tooth shape of the hob tooth of the female rotor is meshed with the tooth groove of the female rotor, and the tooth shape of the hob tooth of the male rotor is meshed with the tooth groove of the male rotor. The invention increases the number of cutter teeth, can directly utilize generating hobbing to process the male and female rotors of the screw, and improves the production efficiency of the screw rotors. In addition, the tooth shape of the screw rotor hob is obtained through back calculation of the screw rotor, and the hob is completely meshed with the tooth shape of the screw rotor in space, so that the precision of the screw rotor obtained by one-time generating and hobbing can meet the use requirement of a workpiece. The machining precision is high, and grinding is not needed again, so that the production cost is reduced.
Description
Technical Field
The invention belongs to the technical field of metal cutter processing, and particularly relates to a hob for processing a screw rotor and a production method thereof.
Background
Screw rotors are typically composed of two rotors, one female and one male. The current method for machining the screw rotor is to use a milling cutter for rough machining and then grinding and finishing. Since the screw rotor includes a male rotor and a female rotor, the milling cutter also includes a male rotor milling cutter and a female rotor milling cutter. However, the existing milling cutter is used for machining the screw rotor, so that the efficiency is low. As shown in fig. 1 and 2, the female rotor milling cutter 1 and the male rotor milling cutter 2 have only one row of cutter teeth in the axial direction, and each tooth of the rotor needs to be machined separately and then ground. Also, because only one row of cutter teeth is provided, the teeth are separated and the cutter is aligned for many times in the processing process, so that the processing efficiency is low. In addition, the processing quality of the cutter teeth is difficult to be effectively ensured due to the fact that the cutter teeth are divided for a plurality of times.
Disclosure of Invention
In view of the above, the present invention provides a hob for processing a screw rotor and a method for producing the same, which utilize the generating hobbing of multiple hob teeth of the hob to improve the processing efficiency of the screw rotor.
The technical scheme of the invention is that a production method for processing a screw rotor hob is characterized by comprising the following steps:
Step 1: drilling inner holes of two pairs of identical bars, and turning a shaft table to determine the length of a cutter body of the rotor hob;
Step 2: turning a thread tooth form along the circumferential direction of the cutter body on the basis of the step 1, and milling chip flutes along the axial direction of the cutter body to obtain cutter blanks of the two pairs of rotor hob;
Step 3: carrying out relieved tooth on a pair of cutter blanks in the step 2 by adopting a female rotor hob relieving cutter to obtain a rough machined female rotor hob; carrying out relieved tooth on the other pair of cutter blanks in the step 2 by adopting a male rotor hob relieving cutter to obtain a rough machined male rotor hob;
step 4: performing relief grinding on the rough machined female rotor hob in the step 3 by adopting a female rotor hob grinding wheel to obtain a finish machined female rotor hob; performing relief grinding on the rough machined male rotor hob in the step 3 by adopting a male rotor hob grinding wheel to obtain a finish machined male rotor hob;
The shape of the blade of the female rotor hob shovel blade is consistent with the shape of the grinding blade of the female rotor hob grinding wheel, the blade shape of the female rotor hob shovel blade is determined by the tooth shape of the female rotor hob tooth, and the tooth shape of the female rotor hob tooth is obtained by inverse calculation of the tooth shape of the female rotor in the screw rotor; the shape of the cutting edge of the male rotor hob shovel blade is consistent with the shape of the grinding edge of the male rotor hob grinding wheel, the tooth shape of the male rotor hob is determined by the tooth shape of the male rotor hob tooth, and the tooth shape of the male rotor hob tooth is obtained by inverse calculation of the tooth shape of the male rotor in the screw rotor.
Further, the processing method of the female rotor hob and the male rotor hob in the step 3 is as follows: the method comprises the steps of sequentially forging, finishing milling cutter blanks and heat treatment to obtain a cuboid cutter blank, and linearly cutting the cuboid cutter blank according to the determined cutting edge shape to obtain a female rotor hob shovel cutter and a male rotor hob shovel cutter, wherein one end of the female rotor hob shovel cutter and one end of the male rotor hob shovel cutter are provided with the cutting edge shape.
Further, the female rotor hob and the male rotor hob each have a tooth top relief angle of 30-35 ° and a side edge relief angle of 3±0.2°.
Further, the processing method of the female rotor hob grinding wheel in the step 4 is as follows: and (3) in a state of uniform rotation of the cylindrical grinding wheel blank, trimming the cylindrical grinding wheel blank through rollers according to the determined shape of the grinding edge to obtain a female rotor hob grinding wheel and a male rotor hob grinding wheel with the outer diameters provided with the grinding edges.
Further, the diameters of the female rotor hob grinding wheel and the male rotor hob grinding wheel are 50-150 mm.
The utility model provides a hobbing cutter of processing screw rod rotor, includes the cutter body that has hole and pillow block, has the cutter tooth on the cutter body evenly arranged, its characterized in that: the chip flutes between the cutter teeth are parallel to the axis of the cutter body, and the cutter teeth are spirally arranged along the circumferential direction of the cutter body; the cutter bodies are two pairs, one pair is a cutter body of a female rotor hob, and the other pair is a cutter body of a male rotor hob; the tooth shape of the hob tooth of the female rotor is meshed with the tooth groove of the female rotor, and the tooth shape of the hob tooth of the male rotor is meshed with the tooth groove of the male rotor.
Further, the cutter body is provided with 10-18 rows of cutter teeth and chip flutes.
Further, the tooth tops and the tooth roots of the tooth shapes of the female rotor hob and the male rotor hob are connected smoothly.
The invention has the advantages that the hob of the screw rotor fundamentally increases the number of the hob teeth, can directly process the male and female rotors of the screw by generating hobbing, and improves the production efficiency of the screw rotor. In addition, the tooth shape of the screw rotor hob is obtained through back calculation of the screw rotor, and the hob is completely meshed with the tooth shape of the screw rotor in space, so that the precision of the screw rotor obtained by one-time generating and hobbing can meet the use requirement of a workpiece. The machining precision is high, and grinding is not needed again, so that the production cost is reduced.
Drawings
Fig. 1 is a schematic view of a structure of a female rotor milling cutter according to the prior art.
Fig. 2 is a schematic structural view of a prior art male rotor milling cutter.
Fig. 3 is a schematic view of the structure of the female rotor hob.
Fig. 4 is a right side view of fig. 3.
Fig. 5 is an axial cross-sectional view of fig. 3.
Fig. 6 is a partial enlarged view at a of fig. 5.
Fig. 7 is a schematic view of the structure of the male rotor hob in the present invention.
Fig. 8 is a right side view of fig. 7.
Fig. 9 is an axial cross-sectional view of fig. 7.
Fig. 10 is a partial enlarged view at B of fig. 9.
Fig. 11 is a schematic view of the structure of a female rotor hob blade.
Fig. 12 is a top view of fig. 11.
Fig. 13 is a schematic view of the structure of a male rotor hob blade.
Fig. 14 is a top view of fig. 13.
Fig. 15 is a schematic structural view of a male rotor hob grinding wheel.
Fig. 16 is a left side view of fig. 15.
Fig. 17 is a schematic view of the structure of a female rotor hob grinding wheel.
Fig. 18 is a left side view of fig. 17.
Fig. 19 is a schematic view of blade processing.
Fig. 20 is a schematic view of grinding wheel processing.
Fig. 21 is a schematic view of a cutting blade rough machining of a rotor hob cutting tooth.
Fig. 22 is a schematic view of the relief finishing of a grinding wheel for a rotor hob.
In the figure: 1. the milling cutter comprises a female rotor milling cutter, 2 male rotor milling cutters, 3 female rotor hob, 4, a pillow block, 5, an inner hole, 6, a chip flute, 7, female rotor hob teeth, 8, male rotor hob, 9, male rotor hob teeth, 10, female rotor hob spade, 11, a blade of the female rotor hob spade, 12, a tooth top relief angle, 13, male rotor hob spade, 14, a blade of the male rotor hob spade, 15, a female rotor hob grinding wheel, 16, a grinding blade of the female rotor hob grinding wheel, 17, a male rotor hob grinding wheel, 18, a grinding blade of the male rotor hob grinding wheel, 19, a molybdenum wire, 20, a roller, 21, a spade movement track, 22 and a grinding wheel movement track.
Detailed Description
In order to make the technical solution of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.
As shown in fig. 3 and 4, and fig. 7 and 8, a hob for machining a screw rotor includes a hob body having an inner bore 5 and a pillow block 4. Cutter teeth are uniformly arranged on the cutter body. The chip flute 6 between the cutter teeth is parallel to the axis of the cutter body. The cutter teeth are in multiple rows and multiple columns, and are spirally arranged along the circumferential direction of the cutter body. The cutter body is provided with 10-18 rows of cutter teeth and chip flutes 6. The chip flute 6 of the rotor hob is a straight flute parallel to the axis, so the end face tooth form is a straight line, and the axial tooth form and the normal tooth form are the same.
As shown in fig. 5 and 6, and fig. 9 and 10, since the screw rotors to be processed according to the present invention are divided into female rotors and male rotors, there are two pairs of cutter bodies, one pair being the cutter body of the female rotor hob 3 and the other pair being the cutter body of the male rotor hob 8. According to the space engagement principle, the tooth shape of the hob tooth of the corresponding rotor is reversely calculated through the tooth shape of the screw rotor. The tooth form of the female rotor hob tooth 7 is meshed with the tooth form of the female rotor. In the tooth form of the female rotor hob tooth 7, the tooth tip and the tooth root are connected smoothly. The tooth form of the hob tooth 9 of the male rotor is meshed with the tooth form of the male rotor. In the tooth form of the male rotor hob tooth 9, the tooth tip and the tooth root are connected smoothly.
A production method for processing a screw rotor hob specifically comprises the following steps:
step 1: and (3) drilling inner holes 5 of two pairs of identical bars, and turning out the shaft table 4 to determine the cutter body length of the rotor hob.
Step 2: and (3) turning a thread tooth form along the circumferential direction of the cutter body on the basis of the step (1), and milling chip flutes 6 along the axial direction of the cutter body to obtain cutter blanks of the two pairs of rotor hob.
Step 3: carrying out relieved tooth on a pair of cutter blanks in the step 2 by adopting a female rotor hob relieving cutter 10 to obtain a rough machined female rotor hob 3; and (3) carrying out relieved tooth on the other pair of cutter blanks in the step (2) by adopting a male rotor hob relieving cutter 13 to obtain the rough machined male rotor hob 8. The relieved tooth processing performed in this step needs to leave a margin of 0.3 to 0.5mm for relief grinding processing in the subsequent step. After the relieved tooth processing is completed, the rotor hob needs to be subjected to heat treatment, and the heat treatment hardness is 65-67 HRC. After the heat treatment is finished, grinding the inner hole 5 and the pillow block 4 of the rotor hob, and then sharpening the front cutting edge of the hob.
Step 4: carrying out relief grinding on the rough machined female rotor hob 3 in the step 3 by adopting a female rotor hob grinding wheel 15 to obtain a finish machined female rotor hob 3; and (3) carrying out relief grinding on the rough machined male rotor hob 8 in the step (3) by adopting a male rotor hob grinding wheel 17 to obtain the finished male rotor hob 8.
As shown in fig. 11 and 12, and fig. 15 and 16, the shape of the blade 11 of the female rotor hob blade is identical to the shape of the grinding blade 16 of the female rotor hob grinding wheel, and is determined by the tooth form of the female rotor hob tooth 7. The tooth form of the female rotor hob tooth 7 is obtained by back calculation of the tooth form of the female rotor in the screw rotor. As shown in fig. 13 and 14, and fig. 17 and 18, the shape of the blade 14 of the male rotor hob blade is identical to the shape of the grinding blade 18 of the male rotor hob grinding wheel, and is determined by the tooth form of the male rotor hob tooth 9. The tooth shape of the male rotor hob tooth 9 is obtained by back calculation of the tooth shape of the male rotor in the screw rotor.
And (3) for the relieved tooth processing in the step (3), the rotating speed of the rotor hob is between 10 and 15r/min according to the outer diameter of the rotor hob. The feeding amount of the shovel blade is divided into a coarse shovel and a fine shovel, wherein the feeding amount of the shovel blade is 0.05-0.15 mm when the shovel blade is coarse, and the feeding amount of the shovel blade is 0.01-0.03 mm when the shovel blade is fine. As shown in fig. 21, in the tooth-relieved process, the relief path 21 is a relief process along the curve of the tooth top relief angle 12 of the rotor hob, so that the tooth shape of the rotor hob is ensured to be completely relieved, and the rear row of cutter teeth cannot be shoveled. When the precision of the relieving is detected, the relieving is arranged on the cutting edge of the rotor hob, and the relieving is qualified when the tooth profile of the relieving and the tooth profile of the hob are seamless.
And (3) controlling the rotating speed of the rotor hob to 2500-3500 r/min and the linear speed to 25-35 m/min for the relief grinding processing in the step (4). The feeding amount of the relief grinding is divided into coarse grinding and fine grinding, wherein the coarse grinding is 0.02-0.05 mm, and the fine grinding is 0.005-0.01 mm. As shown in fig. 22, in the relief grinding process, the relief grinding motion track is to perform relief grinding along the curve of the tooth top relief angle 12 of the rotor hob, so that the relief grinding cannot damage the rear row of cutter teeth, and the tail of the cutter teeth cannot be allowed to bulge. When the relief grinding precision is detected, an enlarged projector is adopted for detection, and the projection multiple is 10-20 times. The rotor hob needs to rotate for detection during detection, and the tooth shape of the rotor hob is qualified when the tooth shape of the rotor hob is within the tolerance of an enlarged drawing with the tolerance under the rotation condition. The tooth form error is generally within 0.005 mm.
From the above, it is known that the production of rotor hobs involves two important machining tools, namely a shovel and a grinding wheel. The specific methods of the two processing tools are as follows:
The processing method of the female rotor hob shovel 10 and the male rotor hob shovel 13 comprises the following steps: the high-strength steel is adopted to obtain a cuboid cutter blank through forging, finishing milling cutter blank and heat treatment of hardness to 65-67 HRC. As shown in fig. 19, the rectangular parallelepiped blade blank is wire-cut by a molybdenum wire 19 to obtain a female rotor hob blade 10 and a male rotor hob blade 13 having blade shapes at one ends. The female rotor hob blade 10 and the male rotor hob blade 13 each have a tooth top relief angle 12 of 30-35 ° and a side edge relief angle of 3±0.2°, so that the blades need to be installed at a certain angle during wire cutting to form a relief angle after the wire cutting is completed. The wire cutting adopts slow wire feeding, and the feeding speed is 0.1-0.3 m/s.
The processing method of the female rotor hob grinding wheel 15 and the male rotor hob grinding wheel 17 comprises the following steps: and adopting 80-100 corundum grinding wheels, wherein the outer diameter of the grinding wheels is 50-150 mm according to the structure of the rotor hob. The cylindrical grinding wheel blank is dressed by the diamond roller 20 in a state of uniform rotation to obtain a female rotor hob grinding wheel 15 and a male rotor hob grinding wheel 17 with outer diameters having grinding edges, as shown in fig. 20. In the finishing process, the rotating speed is 2500-3000 r/min, and the rotating speed of the roller 20 is 4000-6000 r/min. The feeding amount is 0.01-0.05 mm.
The rotor hob obtained through the production and processing has the tooth form which can be completely meshed with the screw rotor, and becomes a full-cutting screw rotor hob, namely the tooth root position of the tooth form of the rotor hob can also participate in cutting. This means that the screw rotor obtained by the one-time generating and hobbing of the invention can reach the use requirement of the workpiece in precision. The method has high processing precision, and grinding processing in the original processing method is not needed again, so that the production cost is reduced.
Claims (5)
1. A production method for processing a screw rotor hob is characterized by comprising the following steps of:
Step 1: drilling inner holes of two pairs of identical bars, and turning a shaft table to determine the length of a cutter body of the rotor hob;
Step 2: turning a thread tooth form along the circumferential direction of the cutter body on the basis of the step 1, and milling chip flutes along the axial direction of the cutter body to obtain cutter blanks of the two pairs of rotor hob;
Step 3: carrying out relieved tooth on a pair of cutter blanks in the step 2 by adopting a female rotor hob relieving cutter to obtain a rough machined female rotor hob; carrying out relieved tooth on the other pair of cutter blanks in the step 2 by adopting a male rotor hob relieving cutter to obtain a rough machined male rotor hob;
step 4: performing relief grinding on the rough machined female rotor hob in the step 3 by adopting a female rotor hob grinding wheel to obtain a finish machined female rotor hob; performing relief grinding on the rough machined male rotor hob in the step 3 by adopting a male rotor hob grinding wheel to obtain a finish machined male rotor hob;
The shape of the blade of the female rotor hob shovel blade is consistent with the shape of the grinding blade of the female rotor hob grinding wheel, the blade shape of the female rotor hob shovel blade is determined by the tooth shape of the female rotor hob tooth, and the tooth shape of the female rotor hob tooth is obtained by inverse calculation of the tooth shape of the female rotor in the screw rotor; the shape of the cutting edge of the male rotor hob shovel blade is consistent with the shape of the grinding edge of the male rotor hob grinding wheel, the tooth shape of the male rotor hob is determined by the tooth shape of the male rotor hob tooth, and the tooth shape of the male rotor hob tooth is obtained by inverse calculation of the tooth shape of the male rotor in the screw rotor.
2. A method of manufacturing a screw rotor hob according to claim 1, characterized in that: the machining method of the female rotor hob and the male rotor hob in the step 3 comprises the following steps: the method comprises the steps of sequentially forging, finishing milling cutter blanks and heat treatment to obtain a cuboid cutter blank, and linearly cutting the cuboid cutter blank according to the determined cutting edge shape to obtain a female rotor hob shovel cutter and a male rotor hob shovel cutter, wherein one end of the female rotor hob shovel cutter and one end of the male rotor hob shovel cutter are provided with the cutting edge shape.
3. A method of producing a screw rotor hob according to claim 1 or 2, characterized in that: the female rotor hob and the male rotor hob have a tooth top relief angle of 30-35 degrees and a side edge relief angle of 3+/-0.2 degrees.
4.A method of manufacturing a screw rotor hob according to claim 1, characterized in that: the processing method of the female rotor hob grinding wheel in the step 4 is as follows: and (3) in a state of uniform rotation of the cylindrical grinding wheel blank, trimming the cylindrical grinding wheel blank through rollers according to the determined shape of the grinding edge to obtain a female rotor hob grinding wheel and a male rotor hob grinding wheel with the outer diameters provided with the grinding edges.
5. A method of producing a screw rotor hob according to claim 1 or 4, characterized in that: the diameters of the female rotor hob grinding wheel and the male rotor hob grinding wheel are 50-150 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711263045.8A CN108044202B (en) | 2017-12-04 | Hob for processing screw rotor and its production method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711263045.8A CN108044202B (en) | 2017-12-04 | Hob for processing screw rotor and its production method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108044202A CN108044202A (en) | 2018-05-18 |
| CN108044202B true CN108044202B (en) | 2024-07-02 |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204934750U (en) * | 2015-08-20 | 2016-01-06 | 天津宇晟金属制品有限公司 | A kind of hobboing cutter |
| CN207629324U (en) * | 2017-12-04 | 2018-07-20 | 汉江工具有限责任公司 | Process the hobboing cutter of screw rotor |
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204934750U (en) * | 2015-08-20 | 2016-01-06 | 天津宇晟金属制品有限公司 | A kind of hobboing cutter |
| CN207629324U (en) * | 2017-12-04 | 2018-07-20 | 汉江工具有限责任公司 | Process the hobboing cutter of screw rotor |
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