CN105855791B - A kind of friction and Extrusion intensifying method of structural member connecting hole - Google Patents
A kind of friction and Extrusion intensifying method of structural member connecting hole Download PDFInfo
- Publication number
- CN105855791B CN105855791B CN201510026828.9A CN201510026828A CN105855791B CN 105855791 B CN105855791 B CN 105855791B CN 201510026828 A CN201510026828 A CN 201510026828A CN 105855791 B CN105855791 B CN 105855791B
- Authority
- CN
- China
- Prior art keywords
- friction
- connecting hole
- extrusion
- extrusion head
- hole
- 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.)
- Expired - Fee Related
Links
Landscapes
- Extrusion Of Metal (AREA)
Abstract
The invention discloses a kind of friction and Extrusion intensifying methods of structural member connecting hole, belong to technical field of mechanical processing.This method is reinforcing tool using friction and Extrusion head as friction and Extrusion, under conditions of keeping 0.02~1mm crushed increscence amount between friction and Extrusion head and connecting hole, friction and Extrusion head is rotated and at the uniform velocity on insert structure part in connecting hole, is then extracted after 2~5s of static rotation；The rotation speed of friction and Extrusion head is 100~1000rpm, and insertion speed is 0.1~2mm/s, and extraction speed is 0.3~2mm/s；It is formed about residual compressive stress in wall surface of the hole in the above process, while Plastic Flow occurs for the material near wall surface of the hole, and generates distortion of lattice, dislocation density increases, and strengthens to realize to the friction and Extrusion of structural member connecting hole.Present invention is mainly used for the reinforcings of important feature part connecting hole in the industry such as Aeronautics and Astronautics, train and ship.
Description
Technical field
The invention belongs to technical fields of mechanical processing, and in particular to a kind of friction and Extrusion reinforcing side of structural member connecting hole
Method is mainly used for the reinforcing of important feature part connecting hole in the industry such as Aeronautics and Astronautics, train and ship.
Background technique
In recent years, the accident that aircraft is damaged because breaking down happens occasionally, the life security of people is seriously threatened.
In the various failures of aircraft, body injury has accounted for 30% or more of total failare quantity.Therefore, the entire life of aircraft mainly determines
Due to organism life-span.Fatigue rupture is the basic reason of airframe disablement, wherein 75~80% fatigue rupture
The connecting portion in housing construction occurs.The main connection means that aircraft structure uses at present are still mechanical connection, a frame
About 150~2,000,000 connectors on large aircraft only solve the connection Fatigue Life Problems of aircraft structure, ability
Guarantee the high life of aircraft, and then guarantees the safety and economy of aircraft utilization.Other than aviation field, space flight, train and
The fields such as ship are also faced with same problem.
In general, technological factor is often to guarantee that connection structure has the determinant of high life, including connecting hole
Dimensional accuracy and surface quality.Under the premise of dimensional accuracy is guaranteed, the surface quality of connecting hole is that influence connector is tired
The principal element in labor service life.The surface quality in hole includes surface roughness, surface microhardness and hardness, flow harden and remnants
Stress layer depth etc..In process, even if machining accuracy is very high, inner surface of the cutter also always in hole leaves cutting mark
Mark, these tool marks, which are formed by rugged ripple, can reduce the intensity of structural connection.In addition, for Aeronautics and Astronautics aluminium
It for alloy and the siding of titanium alloy etc materials, is process generally by rolling mill practice, material internal is dispersed with uniformly
Longitudinal streamline just inevitably cuts off material streamline if processing circular hole in panel surfaces, and the edge in hole forms weak ground
Band, during structure is on active service, crack initiation, extension, even recurring structure are broken easily at this.Therefore, it is necessary to counterweight mian parts
Bit architecture part connecting hole is effectively strengthened.
Currently, the main reinforcement technique of structural member connecting hole has cold extrusion reinforcement technique, mechanic shot peening reinforcement technique, interference
Mating connection technology and finish rolling hardening technology.Wherein, cold extrusion and mechanic shot peening be at present be widely used in both at home and abroad structure resist it is tired
Effective two kinds of reinforcement techniques of labor fracture design.
Cold extrusion reinforcing can be divided into plug cold extrusion and slotted liner bushing cold extrusion.Traditional cold-extrusion technology uses interference
Plug directly squeezes hole wall, although simple process, will cause nose end flange, and seriously damage hole surface.Slotted liner bushing is cold
Extrusion Strengthening Technique overcomes the deficiency of traditional technology, and the bushing to crack is increased between hole wall and plug, uses plug
Bushing is squeezed, bushing again squeezes hole wall, to overcome hole wall caused by plug directly squeezes axially scratch and angle of spot hole
The disadvantage of protrusion, is applied successfully on various structures, is one of state-of-the-art hole reinforcement technique in currently manufactured industry.
However slotted liner bushing extrusion process is relative complex, strengthen all needs one slotted liner bushing of consumption every time, and opens strengthening back bush
It is tensile stress state at seam, the germinating and extension of crackle can be promoted.In addition, can be left after slotted liner bushing cold extrusion in hole wall
Linear boss together need to just can guarantee the mechanical requirements of wall surface of the hole through reaming, but the residual stress distribution in ream device to hole week can produce
Raw large effect.Mechanic shot peening reinforcement process is complicated, aperture hour, it is difficult to which the inner surface of device to hole is strengthened, and empty by operation
Between limit, the connecting hole of many key positions is unable to get effective reinforcing.It is cold for the connecting hole of smaller size
It squeezes and mechanic shot peening is all highly difficult, strengthening effect is also undesirable.
Finish rolling hardening is also a kind of common hole reinforcement technique, according to the difference of rolling component shape, can be divided into ball
Formula, roller type and roller.Usual roller type stitching structure is simple, easily fabricated, and rigidity is preferable, distortion in rolling region and rolling
Pressure is larger, however this stitching is appropriate only for rolling larger-diameter hole；And ball-type and roller roll, the two becomes
Shape region is smaller, applies in general to the hole of medium-small diameter, however its corresponding stitching is structurally and operationally also more complicated.
With the continuous development of development and the engineering application of superpower laser, reiforcing laser impact technology is with it without dirt
The advantages that contaminating, is easy to control, strengthening effect is significant has huge application prospect.It is laser impact intensified in airplane design manufacture
Technology is by the reliability in raising Anti-Fatigue performance, life cycle management, especially in terms of the reinforcing of aperture, plays not
Alternative effect.However, laser impact intensified technical costs is too high, and complex process, currently, being only used as other reinforcings
The supplement of technology.
To sum up, existing hole reinforcement technique there is strengthening effects undesirable, cumbersome, low efficiency, narrow application range
And the problems such as at high cost.
Summary of the invention
For above-mentioned shortcoming present in existing hole reinforcement technique, the purpose of the present invention is to provide a kind of structural members
The ability of hole periphery material anti-crack germinating and extension not only can be enhanced in the friction and Extrusion intensifying method of connecting hole, this method；
And the wall surface scratch generated when drilling can be eliminated, improve the wall quality in hole.Operation of the present invention is simple, high-efficient, is applicable in
Range is wide, at low cost.
To achieve the above object, the technical solution adopted in the present invention is as follows:
A kind of friction and Extrusion intensifying method of structural member connecting hole, this method are strong using friction and Extrusion head as friction and Extrusion
Chemical industry tool rotates friction and Extrusion head under conditions of keeping 0.02~1mm crushed increscence amount between friction and Extrusion head and connecting hole
And at the uniform velocity on insert structure part in connecting hole, then extracted after 2~5s of static rotation；Wherein: the rotation speed of friction and Extrusion head
For 100~1000rpm, the insertion speed on insert structure part in connecting hole is 0.1~2mm/s, the speed extracted out of connecting hole
Degree is 0.3~2mm/s；It is formed about residual compressive stress in wall surface of the hole in the above process, while the material near wall surface of the hole occurs
Plastic Flow, and distortion of lattice is generated, dislocation density increases, and strengthens to realize to the friction and Extrusion of structural member connecting hole.
Friction and Extrusion head used includes cylindrical section and rotary table end in this method, and the junction at cylindrical section and rotary table end is smooth
Transition.
This method specifically comprises the following steps:
(1) it positions centering: friction and Extrusion head being directed at connecting hole, guarantees the axis of friction and Extrusion head and the axis of connecting hole
It is overlapped.
(2) it is rotatably inserted into: the speed rotation by friction and Extrusion head to set, then by the friction and Extrusion head being rotating along connection
The axis direction in hole inserts in the hole.
(3) static rotation: (refer in connecting hole be all the circle of friction and Extrusion head when friction and Extrusion head is fully inserted into connecting hole
When shell of column), stop insertion, and friction and Extrusion head is kept to continue static rotation required time；The static rotation refers to that friction is squeezed
Pressure head only makees the rotary motion around its axis.
(4) rotation is extracted: the axis direction by the friction and Extrusion head being rotating along hole is extracted out of hole.
In above-mentioned strengthening process, the crushed increscence amount refers to half between the cylindrical section and connecting hole of friction and Extrusion head
Diameter magnitude of interference, i.e. single side magnitude of interference.
The material of the structural member connection hole is aluminium, aluminium alloy, magnesium, magnesium alloy, copper, copper alloy, titanium, titanium alloy, height
Temperature alloy, structural carbon steel, structural alloy steel, superhigh intensity steel or stainless steel.
Size of the connecting hole before intensive treatment are as follows: 3~100mm of aperture, 1~30mm of depth；Friction and Extrusion head circle
The length of shell of column should be greater than the depth of connecting hole.
The hardness of the friction and Extrusion head should be greater than the hardness of connection hole material, the surface roughness Ra of friction and Extrusion head
≤0.2μm。
The present invention has the following advantages and beneficial effects:
1, the present invention is the friction and Extrusion intensifying method of structural member connecting hole, and this method is using friction and Extrusion head as friction
Coldworking strengthened tool, under conditions of 0.02~1mm crushed increscence amount is kept between friction and Extrusion head and connecting hole, by friction and Extrusion
Head rotation simultaneously carries out friction and Extrusion reinforcing to it in connecting hole at the uniform velocity on insert structure part；During being somebody's turn to do, in friction and Extrusion head
Under squeezing action, wall surface of the hole is formed about residual compressive stress, and part tensile stress can be offset under service condition, improves around hole
Ambient stress.Under the spin friction effect of friction and Extrusion head, Plastic Flow occurs for the material near wall surface of the hole, and generates crystalline substance
Lattice distortion, dislocation density increase.The above two aspects collective effect enhances the ability of hole periphery material anti-crack germinating and extension.
2, the spin friction effect of friction and Extrusion head can also eliminate the wall surface scratch generated when drilling in the present invention, improve
The wall quality in hole.
3, the present invention by control friction and Extrusion head revolving speed, insertion speed, static rotational time and extracts speed, and with it is suitable
When crushed increscence amount (0.02~1mm) match, the temperature of connecting hole near wall material can be made to reach 50~100 DEG C,
To make material generate a degree of softening, with cold extrusion hardening constituent ratio, the lower pressure that friction and Extrusion head needs when being inserted into is more
Small, the energy of consumption is less, and cost is lower.
4, in intensifying method of the present invention, friction and Extrusion head may be mounted on general machine tool chief axis and use；It is also possible to
Industrial common robot arm.Therefore, compared with existing hole reinforcement technique, this method is more flexible, the scope of application
It is wider.
5, intensifying method of the present invention does not need additional auxiliary appliance, bushing is needed when strengthening such as cold extrusion, and operate
Step is simple, high-efficient, the reinforcing suitable for various metals material hole.
Detailed description of the invention
Fig. 1 is the basic principle of the friction and Extrusion intensifying method of structure of the invention part connecting hole；Wherein: before (a) strengthening；
(b) it is rotatably inserted into and static rotation；(c) rotation is extracted.
Fig. 2 is the friction and Extrusion header structure schematic diagram that the present invention uses.
Fig. 3 is the comparison photo that friction and Extrusion strengthens front and back connecting hole；Wherein: before (a) strengthening；(b) after strengthening.
Fig. 4 is the residual stress distribution connected around hole wall after friction and Extrusion is strengthened；Wherein: (b) is region A in (a)
Residual stress distribution condition.
In figure: 1- connecting hole；2- friction and Extrusion head；21- rotary table end；22- cylindrical section；3- structural member motherboard.
Specific embodiment
Present invention will be further explained below with reference to the attached drawings and examples.
The present invention is the friction and Extrusion intensifying method of structural member connecting hole, and this method is using friction and Extrusion head 2 as friction
Coldworking strengthened tool is operated, and friction and Extrusion head 2 used is cylindric tool, including cylindrical section 22 and rotary table end 21, cylinder
The junction at section 22 and rotary table end 21 is smooth transition, as shown in Figure 2.
Friction and Extrusion intensifying method principle such as Fig. 1 (a)-(c) of the present invention has connecting hole 1 on structural member motherboard 3, is rubbing
It wipes under conditions of keeping 0.02~1mm crushed increscence amount between extrusion head 2 and connecting hole 1, friction and Extrusion head 2 is rotated and at the uniform velocity inserts
Enter on structural member in connecting hole 1, is then extracted after 2~5s of static rotation；Wherein: the rotation speed of friction and Extrusion head 2 be 100~
1000rpm, the insertion speed on insert structure part in connecting hole 1 is 0.1~2mm/s, and the speed extracted out of connecting hole 1 is
0.3~2mm/s；After above-mentioned intensive treatment, on the one hand, under the squeezing action of friction and Extrusion head 2,1 near wall of connecting hole
Residual compressive stress is formed, part tensile stress can be offset under service condition, improves the ambient stress around connecting hole 1；It is another
Aspect, under the spin friction effect of friction and Extrusion head 2, Plastic Flow occurs for the material of 1 near wall of hole, and it is abnormal to generate lattice
Become, dislocation density increases.The above two aspects collective effect enhances the energy of 1 periphery material anti-crack of connecting hole germinating and extension
Power.In addition, the spin friction effect of friction and Extrusion head 2 can also eliminate the wall surface scratch generated when drilling 1, connecting hole 1 is improved
Wall quality.
Embodiment 1
The present embodiment is to carry out friction and Extrusion intensive treatment to the connecting hole on aluminum alloy junction component, wherein motherboard 2mm
Thick 7B04 aluminium alloy sheet, it is 5.6mm that connecting hole, which strengthens front aperture,.Friction and Extrusion head material selects In718 alloy, hardness
Value is much larger than the hardness of 7B04 aluminium alloy, and the diameter of friction and Extrusion head cylindrical section is 6mm, cylinder segment length is 5mm, friction and Extrusion
The surface roughness Ra value of head is 0.2 μm, and single side crushed increscence amount is 0.2mm.Specific intensive treatment process is as follows:
Step 1: positioning centering.Friction and Extrusion head is directed at connecting hole, guarantees the axis and connecting hole of friction and Extrusion head
Axis is overlapped.
Step 2: it is rotatably inserted into.Friction and Extrusion head is rotated with the revolving speed of 100rpm, then the friction and Extrusion head that will be rotating
Connecting hole is inserted into 0.5mm/s speed.
Step 3: static rotation.When the fully extended connecting hole in the rotary table end of friction and Extrusion head, stop insertion, and keep
Friction and Extrusion head continues with the static rotation 2s of the revolving speed of 100rpm.
Step 4: rotation is extracted.Friction and Extrusion head is extracted out of connecting hole with 0.5mm/s speed.
In the present embodiment, crushed increscence amount, friction and Extrusion head revolving speed, insertion speed, static rotational time and extraction speed
Degree, which matches, can make the temperature of 1 near wall material of connecting hole reach about 70 DEG C.
It is the comparison photo that friction and Extrusion strengthens front and back connecting hole shown in Fig. 3, from the figure, it can be seen that after intensive treatment,
The wall surface in hole is more bright and clean, and wall quality is more preferable.
Connecting hole around hole wall and does not have stress, the present embodiment rubs to it before intensive treatment on structural member
Occurs residual stress after coldworking strengthened around hole wall, distribution situation is as shown in Figure 4.It can be seen that most areas near hole wall
Domain is residual compressive stress, and part tensile stress can be offset under service condition, so as to improve the ambient stress around hole, enhances it
The ability of anti-crack germinating and extension, improves the service life in hole.
Claims (7)
1. a kind of friction and Extrusion intensifying method of structural member connecting hole, it is characterised in that: this method be using friction and Extrusion head as
Friction and Extrusion strengthens tool, under conditions of 0.02~1mm crushed increscence amount is kept between friction and Extrusion head and connecting hole, will rub
Extrusion head rotates and at the uniform velocity on insert structure part in connecting hole, then extracts after 2~5s of static rotation；Wherein: friction and Extrusion head
Rotation speed be 100~1000rpm, the insertion speed on insert structure part in connecting hole is 0.1~2mm/s, from connecting hole
The speed of interior extraction is 0.3~2mm/s.
2. the friction and Extrusion intensifying method of structural member connecting hole according to claim 1, it is characterised in that: the friction is squeezed
Pressure head includes cylindrical section and rotary table end, and the junction at cylindrical section and rotary table end is smooth transition.
3. the friction and Extrusion intensifying method of structural member connecting hole according to claim 1 or 2, it is characterised in that: this method
Specifically comprise the following steps:
(1) it positions centering: friction and Extrusion head being directed at connecting hole, guarantees the axis of friction and Extrusion head and the axis weight of connecting hole
It closes；
(2) it is rotatably inserted into: the speed rotation by friction and Extrusion head to set, then by the friction and Extrusion head being rotating along connecting hole
Axis direction inserts in the hole；
(3) static rotation: when friction and Extrusion head is fully inserted into connecting hole, stop insertion, and friction and Extrusion head is kept to continue
The time required to static rotation；
(4) rotation is extracted: the axis direction by the friction and Extrusion head being rotating along hole is extracted out of hole.
4. the friction and Extrusion intensifying method of structural member connecting hole according to claim 3, it is characterised in that: described to squeeze
The amount of being full of refers to the radius magnitude of interference between the cylindrical section and connecting hole of friction and Extrusion head, i.e. single side magnitude of interference.
5. the friction and Extrusion intensifying method of structural member connecting hole according to claim 3, it is characterised in that: the connecting hole
Size before intensive treatment are as follows: 3~100mm of aperture, 1~30mm of depth.
6. the friction and Extrusion intensifying method of structural member connecting hole according to claim 3, it is characterised in that: friction and Extrusion head
The length of cylindrical section should be greater than the depth of connecting hole.
7. the friction and Extrusion intensifying method of structural member connecting hole according to claim 1, it is characterised in that: the friction is squeezed
The hardness of pressure head should be greater than the hardness of connection hole material, friction and Extrusion head surface roughness Ra≤0.2 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510026828.9A CN105855791B (en) | 2015-01-19 | 2015-01-19 | A kind of friction and Extrusion intensifying method of structural member connecting hole |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510026828.9A CN105855791B (en) | 2015-01-19 | 2015-01-19 | A kind of friction and Extrusion intensifying method of structural member connecting hole |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105855791A CN105855791A (en) | 2016-08-17 |
| CN105855791B true CN105855791B (en) | 2018-12-25 |
Family
ID=56622768
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510026828.9A Expired - Fee Related CN105855791B (en) | 2015-01-19 | 2015-01-19 | A kind of friction and Extrusion intensifying method of structural member connecting hole |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105855791B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109822926A (en) * | 2019-03-11 | 2019-05-31 | 浙江众泰汽车制造有限公司 | CFRP/ metallic composite connection structure and its processing tool and processing method |
| CN110170739B (en) * | 2019-06-19 | 2021-01-26 | 南京航空航天大学 | Structural hole remanufacturing and reinforcing method based on friction stir connection |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020174528A1 (en) * | 2000-03-01 | 2002-11-28 | Surface Technology Holdings, Ltd. | Apparatus for providing a residual stress distribution in the surface of a part |
| CN1486803A (en) * | 2003-08-01 | 2004-04-07 | 东风汽车公司 | Metal plate punching and inner extruding reinforcing process |
| CN101942546A (en) * | 2010-10-19 | 2011-01-12 | 江苏大学 | Method and device for laser shock processing of fastening holes |
| CN102080199A (en) * | 2010-12-13 | 2011-06-01 | 中国航空工业集团公司北京航空材料研究院 | Method for extruding and strengthening 7B50-T7751 aluminum alloy thick plate holes |
| CN102205488A (en) * | 2010-03-31 | 2011-10-05 | 中国商用飞机有限责任公司 | Method for processing hole in split-sleeve cold extrusion manner |
| CN103128510A (en) * | 2013-03-20 | 2013-06-05 | 沈阳飞机工业（集团）有限公司 | Machining method of hole extrusion bar |
| CN103952651A (en) * | 2014-05-13 | 2014-07-30 | 中国航空工业集团公司北京航空制造工程研究所 | Combined strengthening method of alloy structural hole |
-
2015
- 2015-01-19 CN CN201510026828.9A patent/CN105855791B/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020174528A1 (en) * | 2000-03-01 | 2002-11-28 | Surface Technology Holdings, Ltd. | Apparatus for providing a residual stress distribution in the surface of a part |
| CN1486803A (en) * | 2003-08-01 | 2004-04-07 | 东风汽车公司 | Metal plate punching and inner extruding reinforcing process |
| CN102205488A (en) * | 2010-03-31 | 2011-10-05 | 中国商用飞机有限责任公司 | Method for processing hole in split-sleeve cold extrusion manner |
| CN101942546A (en) * | 2010-10-19 | 2011-01-12 | 江苏大学 | Method and device for laser shock processing of fastening holes |
| CN102080199A (en) * | 2010-12-13 | 2011-06-01 | 中国航空工业集团公司北京航空材料研究院 | Method for extruding and strengthening 7B50-T7751 aluminum alloy thick plate holes |
| CN103128510A (en) * | 2013-03-20 | 2013-06-05 | 沈阳飞机工业（集团）有限公司 | Machining method of hole extrusion bar |
| CN103952651A (en) * | 2014-05-13 | 2014-07-30 | 中国航空工业集团公司北京航空制造工程研究所 | Combined strengthening method of alloy structural hole |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105855791A (en) | 2016-08-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105855790B (en) | A kind of friction and Extrusion reinforcing tool and method of structural member connecting hole | |
| CN105855791B (en) | A kind of friction and Extrusion intensifying method of structural member connecting hole | |
| CN206509687U (en) | A kind of ultrasonic vibration rolling device | |
| CN106076553A (en) | A kind of cutter structure of single-shaft shredder | |
| CN207887892U (en) | Main shaft unit with ultrasonic cavitation function | |
| CN106925944B (en) | Self-cooling ultrasonic composite extrusion processing device for precision processing | |
| CN104816388B (en) | Crucible process tool | |
| CN204159940U (en) | Head-exchangeable fluted drill | |
| CN207414358U (en) | A kind of skiving platen structure | |
| CN207058347U (en) | A kind of change grinding tool positioning tool | |
| CN207222964U (en) | A kind of knife rest for electrode automatic grinding device | |
| CN215240551U (en) | Self-made can ear disassembling tool | |
| CN206869514U (en) | A kind of cage milling window positioning fixture | |
| CN200940201Y (en) | Sewing length adjustment device | |
| CN209125616U (en) | A kind of hook type shot-blasting machine with double-sealing device | |
| CN205605605U (en) | A bolted connection structure for heavy metallurgical equipment | |
| CN108465527A (en) | A kind of unilateral localization method of rubbish double-shaft crusher main shaft | |
| CN206912880U (en) | A kind of cylinder cap repairing tool of automobile | |
| CN219356444U (en) | Transmission shaft structure of tower mill | |
| CN104454753B (en) | Modified motor spindle component and its processing method | |
| CN211361873U (en) | Fixed thick roller of sander | |
| CN205950607U (en) | Female specialized tool of pump bearing lock | |
| CN220807712U (en) | Roll shaft structure | |
| CN203541743U (en) | Machining tool for catch wheel of rotary kiln | |
| CN207839595U (en) | A kind of pre-finishing mill protective cap |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20181225 Termination date: 20200119 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |