CN106807865A - A kind of gear rolling manufacturing process of use taper rolling wheel - Google Patents
A kind of gear rolling manufacturing process of use taper rolling wheel Download PDFInfo
- Publication number
- CN106807865A CN106807865A CN201710131961.XA CN201710131961A CN106807865A CN 106807865 A CN106807865 A CN 106807865A CN 201710131961 A CN201710131961 A CN 201710131961A CN 106807865 A CN106807865 A CN 106807865A
- Authority
- CN
- China
- Prior art keywords
- tooth
- blank
- rolling wheel
- rolling
- taper
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21H—MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
- B21H5/00—Making gear wheels, racks, spline shafts or worms
- B21H5/02—Making gear wheels, racks, spline shafts or worms with cylindrical outline, e.g. by means of die rolls
- B21H5/022—Finishing gear teeth with cylindrical outline, e.g. burnishing
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Gears, Cams (AREA)
Abstract
A kind of gear rolling manufacturing process of use taper rolling wheel, it is that rolling is carried out to blank with least one taper rolling wheel, the tooth form of the taper rolling wheel is vertically change, each rolling wheel rotating Vortex, blank axial feed, point tooth in initial rolling stage is realized successively, the suppression of lug defect and the finishing of the tooth profile in rolling later stage of shaping stage, in the rotation of taper rolling wheel, with the axial feeding of blank, blank outer rim occurs and completes uniformly to divide tooth successively, tooth form is without lug shaping and flank profil finishing, realize the Accurate Shaping of gear rolling process.The method technical process is easy, it is easy to accomplish, forming quality is good, the machining for eliminating excision lug and the grinding for ensureing flank profil dimensional accuracy, material-saving and machining period, significantly improve the production efficiency and forming quality of gear rolling shaping, and reduce production cost.
Description
Technical field
The present invention relates to a kind of manufacturing process for rolling roller gear, belong to gear rolling forming technique field.
Background technology
Gear is one of most common mechanical organ in modern age machine, is the important foundation parts of engineering goods.At present
The main production of gear is machining and precision forging etc..The precision forging technique of roller gear is substantially
It is to use upsetting-extruding method, the manufacturing process of this closing causes that metal blank is subject to very big in shaping close to the flowing in end of a period stage
Limitation, the resistance of deformation of material steeply rises, cause flank profil to fill that unsatisfactory, required equipment tonnage is big, mould operating mode is severe,
Depanning difficulty etc..
Roll forming is a kind of revolution plastic forming process of continuous local loading local deformation, and deformation force significantly drops
Low, continuous gyration also causes that the percussion to mould is smaller, and the depanning that there's almost no die-forging forming appearance is difficult
The problems such as.Gear rolling technique embodies the advantage of roll forming mode and the advantage of gear forging forming technique, main at present
There are two kinds of basic manufacturing process：Tooth bar rollforming and rolling wheel rollforming.Wherein, rolling wheel Roll-forming processes have more
Practicality.Roller gear rolling wheel technique for rolling principle (or three or more) parameter identical rolling wheel as shown in figure 1, a pair
It is installed in parallel on two main shafts, in the same direction and synchronous rotary is done under the driving of transmission mechanism.Workpiece is fixed with its two ends centre bore
Position, is in freely to rolling state with two rolling wheels all the time.Under the rolling power effect that hydraulic system is provided, two rolling wheel footpaths
Workpiece is contacted and extruded to feeding.With the increase of the amount of clamp-oning, the metal of excircle of workpiece part is between rolling wheel by Fan Chengyun
It is dynamic to form tooth form, until rolling goes out whole gear structure.
Gear rolling shapes typical defect has tooth form lug as shown in Figure 2, flank line asymmetric and end cydariform etc.,
Wherein lug defect is the mass defect of most serious in gear rolling forming technology, is in the top both sides of tooth form in forming process
The projection of formation.Lug phenomenon is built up due to the top layer blank flows faster contacted with rolling wheel during rolling
Formed, be under gear rolling shaping mode of texturing intrinsic deformation behaviour, it is necessary to pass through machining excision lug.By work
Skill parameter is allocated, it is difficult to significantly improve or eliminate tooth form lug phenomenon.Additionally, the rollforming starting stage, blank is with rolling
During wheel rotation point tooth, side set phenomenon, side set and a point tooth inequality is easily produced all to influence rollforming quality due to skidding,
Shaping is caused to fail when serious.Meanwhile, in shaping ending phase, due to rolling wheel tooth top, tooth root and shaping tooth form tooth root, tooth top
All it is simultaneously contact, tooth root keeps certain gap state with gear tip clearance during rather than master gear engaged transmission, therefore, rotation
During turning, flank profil bottom, rolling wheel tooth root and the blank screw-in tooth flank profil top that rolling wheel tooth top screws out tooth with blank can be sent out
Raw interference, forces blank tooth form to deform, and causes that the profile accuracy of rollforming cannot be guaranteed.
In sum, in existing gear rolling manufacturing process, rolling wheel shaft only radially send relative between blank axle
Enter motion and rotary motion, mutual axial movement is had no between rolling wheel shaft and blank axle, under the motion mode, rolling wheel
Tooth-shape structure be vertically necessarily uniform form with ring so that initial in gear rolling shaping nipping uniformly point tooth, into
The lug defect in shape stage suppresses and the finishing of shaping later stage tooth profile is difficult to be realized by a set of rolling wheel.
The content of the invention
The present invention is for only radial feed motion and rotation between rolling wheel and blank in existing gear rolling forming technique
The limitation transported dynamic forms of motion and brought to the control of gear rolling forming process, proposes a kind of simple and convenient, low cost, energy
It is enough to realize uniformly point tooth, suppression lug, the gear rolling manufacturing process of the use taper rolling wheel of finishing flank profil.
The gear rolling manufacturing process of use taper rolling wheel of the invention, be：
Rolling is carried out to blank with least one taper rolling wheel, the tooth form of the taper rolling wheel is vertically change
, each rolling wheel rotating Vortex, blank axial feed realizes point tooth, the lug of shaping stage in initial rolling stage successively
Defect suppression and the finishing of the tooth profile in rolling later stage；In the rotation of taper rolling wheel, with the axial feeding of blank, base
Material outer rim occurs and completes uniformly to divide tooth, tooth form to be shaped without lug and flank profil finishing successively, realizes gear rolling process
Accurate Shaping.
Said process uses taper rolling wheel, and axial feeding and rotary motion are produced between rolling wheel and blank, overcomes
A set of rolling wheel cannot simultaneously be realized uniformly dividing tooth, suppress lug, tooth profile essence in existing gear rolling forming process
Whole forming quality requirement.The uniformly forming quality requirement such as point tooth, suppression lug, finishing flank profil is realized by a set of rolling wheel.
The taper rolling wheel is divided into Fen Chi areas, formation zone and Runout area in the axial direction, and its tooth form is vertically in three areas
It is change；The tooth form cone angle in Fen Chi areas is 25 °~30 ° (tooth form is sharper, is beneficial to a point tooth), and tooth is a height of to intend formed gear modulus
0.20~0.25 times；Taper rolling wheel interlude is formation zone, and the tooth form pitch of formation zone gradually decreases to standard tooth form
Pitch, meanwhile, formation zone root circle size according to the dimensional uniformity design grown tall without lug tooth form, with during suppressing rolling
The appearance of lug defect；The port of export of taper rolling wheel is Runout area, and the tooth form pitch of Runout area is constant, and the tooth top chi of tooth form
It is very little to be gradually reduced, gradually decrease to the tooth top size of standard tooth form engagement.
The root radius of the formation zone of the taper rolling wheel is：
rf=a-r0-hj,
In formula：A is the centre-to-centre spacing of taper rolling wheel and blank；r0It is the initial radium of blank；hjFor blank tooth form is grown tall
Amount, hj=φ (f), f are axial feeding length of the blank in taper rolling wheel formation zone, hjShaped in taper rolling wheel with blank
The axial feeding length f in area is related, and its numerical value passes through blank rolling wheel at the axial feeding position of taper rolling wheel formation zone
The relation that the volume of tooth form press-in blank is equal with the volume that blank tooth form is grown tall is tried to achieve.
The present invention changes the motion side between the structure type of rolling wheel and rolling wheel and blank during former rolling
Formula, using taper rolling wheel structure type, to eliminate bring in original gear rolling complex degree of structure and be synchronized with the movement and is difficult
The rolling wheel radial feed motion of control.
The present invention realizes gear rolling each stage to improve gear rolling morphoplasm not only through rolling wheel structure design
Amount and to the requirement of forming process, the also overall simplified complexity of rollforming system so that gear rolling shaped
Journey is easy, it is easy to accomplish, forming quality is good, and profile accuracy is high, is capable of achieving the Accurate Shaping of gear rolling, eliminates tooth form lug machine
Tool processing and the finishing of flank profil size, material-saving and machining period, significantly improve the production of roller gear rollforming
Efficiency, reduces production cost.
Brief description of the drawings
Fig. 1 is existing cogged rolling wheel rollforming principle schematic.
Fig. 2 is the lug defect schematic diagram of the rolling wheel rollforming presence of gear.
Fig. 3 is principle schematic of the present invention using the gear rolling manufacturing process of taper rolling wheel.
Fig. 4 is the structural representation of taper rolling wheel in the present invention.
Fig. 5 is rolling process schematic diagram of the taper rolling wheel to blank in the present invention.
Fig. 6 is that tooth form volume of growing tall is equal to rolling form of gear tooth involute generating motion envelope and is formed during rolling of the present invention
Press-in blank volume schematic diagram.
In figure：1. taper rolling wheel, 2. blank.
Specific embodiment
It is with least one (in Fig. 3 as shown in figure 3, the gear rolling manufacturing process of use taper rolling wheel of the invention
Set two) taper rolling wheel 1 carries out rolling to blank 2, taper rolling wheel 1 during rotating Vortex, the axial feeding of blank 2
And rotated under the drive of taper rolling wheel 1.Of the invention to be with existing rolling wheel technique for rolling difference, the present invention is used
Rolling wheel be the pyramidal structure shown in Fig. 4, its tooth form is change along its axial direction, and the tooth-shape structure of change is according to gear rolling
Point tooth (starting stage), the requirement of tooth forming (shaping stage) and flank profil finishing (rolling later stage) of process and set
Meter, reaches that rolling process starting stage point tooth is uniform, shaping stage eliminates tooth form lug defect and rolling later stage tooth profile
The purpose of finishing, acquisition need not cut off the accurate rollforming of the grinding of the machining and guarantee profile accuracy of lug
Gear.
As shown in figure 4, the structure of taper rolling wheel 1 is divided into Fen Chi areas, formation zone and Runout area, its tooth form is vertically three
Individual area is change.The arrival end of taper rolling wheel is with the importing Jiao Fenchi areas for being easy to blank to be sent into, the tooth in Fen Chi areas
Shape is sharper, is beneficial to a point tooth, and tooth form cone angle scope is 25 °~30 °, a height of intend formed gear modulus 0.20~0.25 times of tooth.
Taper rolling wheel interlude is formation zone, and the tooth form pitch of formation zone gradually decreases to the pitch of standard tooth form, meanwhile, formation zone
Root circle size according to the dimensional uniformity design grown tall without lug tooth form, to suppress the appearance of lug defect during rolling.
The port of export of taper rolling wheel is Runout area, and the tooth form pitch of Runout area is constant, and the tooth top size of tooth form is gradually reduced, gradually
It is reduced to the tooth top size of standard tooth form engagement.
As shown in figure 4, before rolling, the front end of blank 2 is located at the inlet orifice of taper rolling wheel 1, and taper rolling wheel 1 at the uniform velocity revolves
Turn, the axial feeding of blank 2, tooth form of its front end gradually with taper rolling wheel 1 in taper rolling wheel inlet orifice is contacted, and is first carried out
Blank outer rim pattern such as Fig. 5 after stage i (starting stage) point tooth, the tooth form of the taper rolling wheel in point tooth stage and point tooth
Shown in (a).When blank continues axial feeding, phase il (shaping stage), the taper rolling form of gear tooth of shaping stage are entered into
Pitch be gradually reduced, shown in tooth form such as Fig. 5 (b) (c) of its tooth-shape structure and shaping stage blank, the stage rolling wheel
Tooth-shape structure in addition to the standard pitch that pitch is gradually transitioned into standard tooth form by the higher value in point tooth stage, the chi of its tooth root
The very little dimensional uniformity that should be grown tall according to the stage tooth form is designed, effectively to suppress the generation of lug.When blank continues to send
When entering, into ii I-stage (finishing stage), the tooth form for terminating shaping carries out repairing for flank profil in rolling wheel finishing Structure Stage
Just, the tooth form pitch of the stage rolling wheel is constant, and the tooth top size of tooth form is gradually reduced, and is gradually transitions master gear engagement
Tooth top size during transmission, completes the finishing of tooth profile.
Taper rolling wheel formation zone root circle size is designed by procedure below：
The purpose of the root circle size-modify design of the formation zone of taper rolling wheel 1 is to suppress the formation of lug, that is to say, that
During the axial feeding of shaping stage, blank tooth form is gradually formed and grown tall blank 2, the rolling wheel root face of shaping stage
Need to fit the uniform tooth form tooth top surface grown tall of blank to reach the purpose that suppression lug is generated.As shown in fig. 6, according to metal
Plastic Forming constancy of volume criterion, the tooth form of wheel blank is grown tall volume SBase toothEqual to the involute generating motion that rolling wheel is pressed into blank
The wheel blank teeth groove volume S that envelope is formedBase groove, understanding by analysis, the tooth top press-in generating motion of blank 2 of taper rolling wheel 1 is formed
Blank surface teeth groove volume SBase grooveIt is equivalent to volume S of the rolling wheel teeth groove in the compression distanceRace.By SBase groove=SRace, ask
The size of forming solution stage axial root circle everywhere.
The transverse tooth thickness of any circle is at the tooth of taper rolling wheel 1
In formula：riIt is any radius of circle；R is reference radius；δ is reference circle transverse tooth thickness；αiIt is any circle pressure angle；α is to divide
Degree circle pressure angle.
The teeth groove thickness of any circle of the tooth of tapper shape pinch roller 1 is
In formula：Z is rolling tooth number, and remaining variables are ibid.
When the intrusion of taper rolling wheel 1 is hiWhen, then under equal intrusion rolling wheel teeth groove volume SRaceFor
In formula：rfIt is rolling wheel root radius.
Gear blank grows volume SBase toothFor
In formula：hjIt is a large amount long of blank tooth form.
In the rollforming stage, the taper rolling wheel tooth top with tapered (cone angle is β, sees Fig. 4) is with sending the axial direction of blank
And then it is gradually pressed into that blank is cylindrical, the Radial feed quantity h of taper rolling wheel 1iTaper rolling wheel formation zone is entered into blank
Relation between axial feeding length f is
hi=ftg β (2-3)
Simultaneous equations (2-1), (2-2) and (2-3) can draw tooth form a large amount h longjShaped in taper rolling wheel with blank
Relation between the axial feeding length f in area, i.e.,：
hj=φ (f) (2-4)
That is, according to above formula, the tooth form a large amount long for just setting up blank 2 in shaping stage is rolled with blank in taper
Relation between the axial feeding length of pinch roller formation zone.
The center of blank 2 is invariable during rolling with the distance at the center of taper rolling wheel 1, if rolling
The tooth root of wheel can fit with the outer rim that blank tooth form is grown tall just, just can suppress the generation of tooth form lug, i.e., now with blank tooth
The root radius of shape tooth corresponding taper rolling wheel 1 high is
rf=a-r0-hj (2-5)
In formula：A is the centre-to-centre spacing of taper rolling wheel 1 and blank 2；r0It is the initial radium of blank 2.
As long as that is, the root radius of the formation zone of taper rolling wheel 1 has tried to achieve h according to by formula (2-4)jAfterwards again
The r determined by formula (2-5)fValue is designed, and the taper rolling wheel just can suppress the formation of tooth form lug during rolling.
Claims (3)
1. a kind of gear rolling manufacturing process of use taper rolling wheel, it is characterized in that：
Rolling is carried out to blank with least one taper rolling wheel, the tooth form of the taper rolling wheel is vertically change, respectively
Individual rolling wheel rotating Vortex, blank axial feed realizes the lug defect suppression of point tooth, shaping stage in initial rolling stage successively
The finishing of the tooth profile in system and rolling later stage；In the rotation of taper rolling wheel, with the axial feeding of blank, blank outer rim
Occur and complete uniformly to divide tooth, tooth form to be shaped without lug and flank profil finishing successively, realize gear rolling process it is accurate into
Shape.
2. the gear rolling manufacturing process of use taper rolling wheel according to claim 1, it is characterized in that：The taper rolling
Pinch roller is divided into Fen Chi areas, formation zone and Runout area in the axial direction, and its tooth form is vertically change in three areas；The tooth in Fen Chi areas
Shape cone angle is 25 °~30 °, a height of intend formed gear modulus 0.20~0.25 times of tooth；Taper rolling wheel interlude is formation zone,
The tooth form pitch of formation zone gradually decreases to the pitch of standard tooth form, meanwhile, formation zone root circle size is according to without lug tooth form
The dimensional uniformity design grown tall, to suppress the appearance of lug defect during rolling；The port of export of taper rolling wheel is finishing
Area, the tooth form pitch of Runout area is constant, and the tooth top size of tooth form is gradually reduced, and gradually decreases to the tooth top of standard tooth form engagement
Size.
3. the gear rolling manufacturing process of use taper rolling wheel according to claim 2, it is characterized in that：The taper rolling
The root radius of the formation zone of pinch roller is：
rf=a-r0-hj,
In formula：A is the centre-to-centre spacing of taper rolling wheel and blank；r0It is the initial radium of blank；hjIt is blank tooth form a large amount long, hj
=φ (f), f are axial feeding length of the blank in taper rolling wheel formation zone, hjWith blank in taper rolling wheel formation zone
Axial feeding length f is related, and its numerical value rolls form of gear tooth by blank at the axial feeding position of taper rolling wheel formation zone
The relation that the volume of press-in blank is equal with the volume that blank tooth form is grown tall is tried to achieve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710131961.XA CN106807865B (en) | 2017-03-07 | 2017-03-07 | A kind of gear rolling manufacturing process using taper rolling wheel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710131961.XA CN106807865B (en) | 2017-03-07 | 2017-03-07 | A kind of gear rolling manufacturing process using taper rolling wheel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106807865A true CN106807865A (en) | 2017-06-09 |
| CN106807865B CN106807865B (en) | 2018-06-01 |
Family
ID=59116128
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710131961.XA Active CN106807865B (en) | 2017-03-07 | 2017-03-07 | A kind of gear rolling manufacturing process using taper rolling wheel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106807865B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111558685A (en) * | 2020-05-14 | 2020-08-21 | 西安交通大学 | Method for forging and rolling composite forming of large-tooth high worm and radial forging die |
| CN111571234A (en) * | 2020-04-30 | 2020-08-25 | 徐云涛 | Forging process of single-oil-groove helical gear |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1558086A (en) * | 1922-12-23 | 1925-10-20 | Charles O Gustavsen | Machine for rolling gears |
| US2906147A (en) * | 1955-11-18 | 1959-09-29 | Michigan Tool Co | Roll for forming toothed elements |
| CN1103016A (en) * | 1993-11-19 | 1995-05-31 | 戴凤林 | Gear working method and device |
| JP2009012080A (en) * | 2008-10-24 | 2009-01-22 | Jtekt Corp | External tooth forming roller |
| CN104438993A (en) * | 2014-10-22 | 2015-03-25 | 山东大学 | Gear rolling forming method for overcoming tooth-form lug defect |
-
2017
- 2017-03-07 CN CN201710131961.XA patent/CN106807865B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1558086A (en) * | 1922-12-23 | 1925-10-20 | Charles O Gustavsen | Machine for rolling gears |
| US2906147A (en) * | 1955-11-18 | 1959-09-29 | Michigan Tool Co | Roll for forming toothed elements |
| CN1103016A (en) * | 1993-11-19 | 1995-05-31 | 戴凤林 | Gear working method and device |
| JP2009012080A (en) * | 2008-10-24 | 2009-01-22 | Jtekt Corp | External tooth forming roller |
| CN104438993A (en) * | 2014-10-22 | 2015-03-25 | 山东大学 | Gear rolling forming method for overcoming tooth-form lug defect |
Non-Patent Citations (1)
| Title |
|---|
| 王广春等: "齿轮滚轧成形技术及其研究进展", 《航空制造技术》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111571234A (en) * | 2020-04-30 | 2020-08-25 | 徐云涛 | Forging process of single-oil-groove helical gear |
| CN111571234B (en) * | 2020-04-30 | 2021-12-07 | 西伯瀚(泰兴)传动技术有限公司 | Forging process of single-oil-groove helical gear |
| CN111558685A (en) * | 2020-05-14 | 2020-08-21 | 西安交通大学 | Method for forging and rolling composite forming of large-tooth high worm and radial forging die |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106807865B (en) | 2018-06-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6154954B2 (en) | Method for rolling thread outside pipe, rolling head and apparatus therefor | |
| CN103316926B (en) | Cold rolling forming method for automotive hub bearing ring part with L-shaped cross section | |
| US20200346262A1 (en) | Device and method for forming shaft part by two-roller flexible skew rolling | |
| WO2011012070A1 (en) | Roll forming method for wheel spoke | |
| CN100581678C (en) | Moulds and methods for forming blanks of worm shafts rolled with roller wedge laterally | |
| CN102357531A (en) | Composite roll forming process of thick-wall deep-groove ring member | |
| CN106984686B (en) | A kind of aluminium alloy wheel hub shear spinning shapes method and demoulding mechanism | |
| CN106807865B (en) | A kind of gear rolling manufacturing process using taper rolling wheel | |
| CN102009112A (en) | Method for thickening annular outer edge of circular plate material | |
| Li et al. | Numerical-experimental investigation on the rabbit ear formation mechanism in gear rolling | |
| CN103316983A (en) | Two-wheel flexible spinning technology applicable to radial grooves of synchronous cog belt pulleys | |
| CN106734802A (en) | Super-huge thick wall head forging rotary rolling manufacturing process and building mortion | |
| CN109926533A (en) | A kind of precision plastic forming method of bevel gear | |
| CN101439461B (en) | Technique for producing and processing chamfering tool for cylindrical gear double-side tooth profile | |
| CN110479836B (en) | Spin forming method for part with regular polygonal section | |
| CN103357661B (en) | A kind of universal rolling technique of round steel | |
| US8539806B2 (en) | Roll forming method for producing longitudinally toothed profiled bodies in pot-shaped cylindrical workpieces | |
| CN103495617B (en) | A kind of change wall thickness cylinder part Roll-extrusion forming device | |
| CN103341514A (en) | Roller extrusion deflashing forming device of curve rotary appearance cylinder part | |
| CN206046960U (en) | A kind of involute gear rolling die | |
| CN100408223C (en) | Roller type wedge cross-rolling process of shaping eccentric stepped shaft | |
| CN114769454A (en) | Flexible gear and strengthening and toughening cold machining method thereof | |
| CN109759527B (en) | Multi-pass simultaneous rolling die and method for large-diameter tooth-shaped piece | |
| CN103230994A (en) | Device and method for forming imprint of micro groove on shaft through stepping rolling | |
| CN101222990A (en) | Hand tool head production method and roller mill |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |