CN204639283U - A kind of for precision machined titanium alloy ball-end mill - Google Patents
A kind of for precision machined titanium alloy ball-end mill Download PDFInfo
- Publication number
- CN204639283U CN204639283U CN201520301868.5U CN201520301868U CN204639283U CN 204639283 U CN204639283 U CN 204639283U CN 201520301868 U CN201520301868 U CN 201520301868U CN 204639283 U CN204639283 U CN 204639283U
- Authority
- CN
- China
- Prior art keywords
- cutting edge
- cutting
- radiused
- sword
- spiral
- 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.)
- Active
Links
Landscapes
- Milling Processes (AREA)
Abstract
The utility model discloses a kind of for precision machined titanium alloy ball-end mill, comprise cutting portion, cutting portion is provided with the first radiused cutting edge, second radiused cutting edge and three-arc shape cutting edge, angle between first radiused cutting edge with the second radiused cutting edge is identical with the angle between three-arc shape cutting edge and the second radiused cutting edge, first radiused cutting edge and the second radiused cutting edge surround first and enter to consider groove to be worth doing, second radiused cutting edge and three-arc shape cutting edge surround second and enter to consider to be worth doing groove, cutting is provided with the first spiral cutting sword, second spiral cutting sword and the 3rd spiral cutting sword, first spiral cutting sword, second spiral cutting sword and cutting portion surround the first chip area, first chip area and first enters to consider to be worth doing groove and is communicated with, second spiral cutting sword, 3rd spiral cutting sword and cutting portion surround the second chip area, second chip area and second enters to consider to be worth doing groove and is communicated with.By the way, stability and the chip removal ability of titanium alloy ball-end mill is improved.
Description
Technical field
The utility model relates to cutting-tool engineering field, particularly relates to a kind of for precision machined titanium alloy ball-end mill.
Background technology
Rose cutter is used for a kind of Common Use Tools of Digit Control Machine Tool processed complex curved surface, and it has a wide range of applications in industries such as Making mold, automobile making, space flight and aviation and telecommunications.
Under normal circumstances, the front end of rose cutter arranges the blade of circular arc, and the blade of circular arc is bulb shape, and the blade of rose cutter is provided with the blade of spiral.Inventor of the present utility model finds in studying for a long period of time: because the blade of the circular arc of rose cutter of the prior art is uneven, causes rose cutter in the process of cutting pin processing, poor stability; In addition, the chip removal performance of rose cutter of the prior art is also poor.
Utility model content
The technical problem that the utility model mainly solves is to provide a kind of for precision machined titanium alloy ball-end mill, improves in the process of machining, the stability of titanium alloy ball-end mill and chip removal ability; In addition, increase cooling mechanism again, conveniently cooling process is carried out to titanium alloy ball-end mill.
For solving the problems of the technologies described above, the technical scheme that the utility model adopts is: provide a kind of for precision machined titanium alloy ball-end mill, comprise shank section, cutting portion, one end of described cutting portion is connected with described shank section, the end face of the other end of described cutting portion is provided with the first radiused cutting edge, second radiused cutting edge and three-arc shape cutting edge, described first radiused cutting edge is identical with the angle between described three-arc shape cutting edge and the second radiused cutting edge with the angle between the second radiused cutting edge, described first radiused cutting edge and the second radiused cutting edge surround first and enter to consider groove to be worth doing, described second radiused cutting edge and three-arc shape cutting edge surround second and enter to consider to be worth doing groove, the side face of described cutting portion is provided with helical first spiral cutting sword, second spiral cutting sword and the 3rd spiral cutting sword, described first spiral cutting sword is connected with described first radiused cutting edge, described second spiral cutting sword is connected with described second radiused cutting edge, described 3rd spiral cutting sword is connected with described three-arc shape cutting edge, described first spiral cutting sword, described second spiral cutting sword and cutting portion surround the first chip area, described first chip area and described first enters to consider to be worth doing groove and is communicated with, described second spiral cutting sword, described 3rd spiral cutting sword and cutting portion surround the second chip area, described second chip area and described second enters to consider to be worth doing groove and is communicated with, described shank section, cutting portion, the first radiused cutting edge, the second radiused cutting edge, three-arc shape cutting edge, the first spiral cutting sword, the second spiral cutting sword and be that the 3rd spiral cutting sword is formed in one, and be titanium alloy.
Wherein, the arc chord angle of described first radiused cutting edge, the second radiused cutting edge and three-arc shape cutting edge is 45 degree.
Wherein, the helical angle of described first spiral cutting sword, the second spiral cutting sword and the 3rd spiral cutting sword is 45 degree.
Wherein, described titanium alloy ball-end mill also comprises auxiliary rod and the first latch, and one end of described auxiliary rod is provided with the first perforate; Described shank section is also provided with accommodating groove and the first jack, described first jack is communicated with described accommodating groove, and described first jack is near one end of described accommodating groove, wherein, described accommodating groove is for accommodating described auxiliary rod, described first jack is just to described first perforate, and described first latch is for being plugged in described first jack and described first perforate.
Wherein, described shank section also arranges the second jack, and described second jack is near the other end of described accommodating groove; Described titanium alloy ball-end mill also comprises the second latch; The other end of described auxiliary rod is also provided with the second perforate, and described second jack is just to described second perforate, and described second latch is for being plugged in described second jack and described second perforate.
Wherein, the shape of described first perforate, the first jack, the second perforate and the second jack is circle; The shape in the cross section of described first latch and the second latch is circle.
Wherein, described first spiral cutting sword, the second spiral cutting sword and/or the 3rd spiral cutting sword are provided with chip groove.
Wherein, described shank section is provided with first passage and annular intake chamber, and wherein, described intake chamber is positioned at the sidewall of described shank section, and the bottom of described intake chamber is communicated with one end of described first passage; Described cutting portion is provided with second channel and Cooling Holes, one end of described second channel is communicated with the other end of described first passage, the other end of described second channel is communicated with described Cooling Holes, and described Cooling Holes is positioned at described cutting portion one end away from described shank section.
Wherein, the quantity of described Cooling Holes is at least three, and described at least three Cooling Holes are respectively just to described first radiused cutting edge, the second radiused cutting edge and three-arc shape cutting edge.
Wherein, the shape in the cross section of described annular intake chamber is V-arrangement.
The beneficial effects of the utility model are: the situation being different from prior art, the utility model arranges the first radiused cutting edge, the second radiused cutting edge and three-arc shape cutting edge on the end face of the other end of cutting portion, angle between first radiused cutting edge with the second radiused cutting edge is identical with the angle between three-arc shape cutting edge and the second radiused cutting edge, titanium alloy ball-end mill is cut, titanium alloy ball-end mill is more stable, is applicable to Precision Machining, in addition, first radiused cutting edge and the second radiused cutting edge surround first and enter to consider groove to be worth doing, three-arc shape cutting edge and the second radiused cutting edge surround second and enter to consider to be worth doing groove, the side face of cutting portion is provided with the first spiral cutting sword, second spiral cutting sword and the 3rd spiral cutting sword, first spiral cutting sword, described second spiral cutting sword and cutting portion surround the first chip area, first chip area and first enters to consider to be worth doing groove and is communicated with, 3rd spiral cutting sword, second spiral cutting sword and cutting portion surround the second chip area, second chip area and second enters to consider to be worth doing groove and is communicated with, first chip area and first enters to consider to be worth doing groove and forms the first channel of chip removal, second chip area and second enters to consider to be worth doing groove and forms the second channel of chip removal, by the first channel of chip removal, second channel of chip removal two channel of chip removal carries out chip removal, strengthen the chip removal performance of titanium alloy ball-end mill.
Accompanying drawing explanation
Fig. 1 is the schematic diagram of this practicality for precision machined titanium alloy ball-end mill first embodiment;
Fig. 2 is the side schematic view of this practicality for precision machined titanium alloy ball-end mill second embodiment;
Fig. 3 is the front schematic view of this practicality for precision machined titanium alloy ball-end mill second embodiment;
Detailed description of the invention
For the ease of understanding the utility model, below in conjunction with the drawings and specific embodiments, the utility model is described in detail.It should be noted that, when element is stated " being fixed on " another element, it can directly on another element or can there is one or more element placed in the middle therebetween.When an element is stated " connection " another element, it can be directly connected to another element or can there is one or more element placed in the middle therebetween.The term " vertical " that this description uses, " level ", "left", "right" and similar statement are just for illustrative purposes.
Unless otherwise defined, all technology of using of this description and scientific terminology are identical with belonging to the implication that those skilled in the art of the present utility model understand usually.The object of the term used in description of the present utility model in this description just in order to describe concrete embodiment is not for limiting the utility model.The term "and/or" that this description uses comprises arbitrary and all combinations of one or more relevant Listed Items.
Refer to Fig. 1, Fig. 1 is the schematic diagram of the utility model for precision machined titanium alloy ball-end mill first embodiment, comprises shank section 21 and cutting portion 22 for precision machined titanium alloy ball-end mill 20.
One end of cutting portion 22 is connected with shank section 21.The end face of the other end of cutting portion 22 arranges the first radiused cutting edge 220, second radiused cutting edge 221 and three-arc shape cutting edge 222, angle between first radiused cutting edge 220 with the second radiused cutting edge 221 is identical with the angle between three-arc shape cutting edge 222 and the second radiused cutting edge 221, make titanium alloy ball-end mill 20 when cutting object, first radiused cutting edge 220, second radiused cutting edge 221 and three-arc shape cutting edge 222 are simultaneously and object contact, ensure the stability of titanium alloy ball-end mill 20 in cutting process.
First radiused cutting edge 220 and the second radiused cutting edge 221 surround first and enter to consider to be worth doing groove 223, three-arc shape cutting edge 222 and the second radiused cutting edge 221 surround second and enter to consider to be worth doing groove 224, the side face of cutting portion 22 is provided with helical first spiral cutting sword 225, second spiral cutting sword 226 and the 3rd spiral cutting sword 227, first spiral cutting sword 225 is connected with the first radiused cutting edge 220, second spiral cutting sword 226 is connected with the second radiused cutting edge 221, 3rd spiral cutting sword 227 is connected with three-arc shape cutting edge 222, first spiral cutting sword 225, second spiral cutting sword 226 and cutting portion 22 surround the first chip area 228, first chip area 228 and first enters to consider to be worth doing groove 223 and is communicated with, 3rd spiral cutting sword 227, second spiral cutting sword 226 and cutting portion 22 surround the second chip area 229, second chip area 229 and second enters to consider to be worth doing groove 224 and is communicated with, wherein, first chip area 228 and first enters to consider to be worth doing groove 223 and forms the first channel of chip removal, second chip area 229 and second enters to consider to be worth doing groove 224 and forms the second channel of chip removal, by the first channel of chip removal, second channel of chip removal two channel of chip removal carries out chip removal, improve the chip removal performance of titanium alloy ball-end mill 20.
Further, shank section 21, cutting portion 22, first radiused cutting edge 220, second radiused cutting edge 221, three-arc shape cutting edge 222, first spiral cutting sword 225, second spiral cutting sword 226 and be that the 3rd spiral cutting sword 227 is formed in one, and be titanium alloy.Because the hardness of titanium alloy is higher, strengthen the hardness of titanium alloy ball-end mill 20.In the present embodiment, preferably, the arc angle of the first radiused cutting edge, the second radiused cutting edge and three-arc shape cutting edge is 45 degree, and the helical angle of the first spiral cutting sword, the second spiral cutting sword and the 3rd spiral cutting sword is 45 degree.
In order to avoid titanium alloy ball-end mill produces larger chip when cutting, and larger chip easily damages radiused cutting edge and spiral cutting sword, therefore, first spiral cutting sword 225, second spiral cutting sword 226 and/or the 3rd spiral cutting sword 227 are provided with chip groove (not shown), by chip groove, secondary cutting is carried out to larger chip, larger chip cutting is become less bits.
Due to titanium alloy ball-end mill usually with driving arrangement, such as milling machine, with the use of, therefore, need titanium alloy ball-end mill to be arranged on driving arrangement or from driving arrangement to disassemble, and the installation and removal of conveniently titanium alloy ball-end mill, titanium alloy ball-end mill also can be provided with the convenient mechanism of installing or dismantling, as shown in Figures 2 and 3, Fig. 2 is the side schematic view of the utility model precision machined titanium alloy ball-end mill second embodiment, Fig. 3 is the front schematic view of the utility model precision machined titanium alloy ball-end mill second embodiment, titanium alloy ball-end mill second embodiment and the first embodiment difference are:
Titanium alloy ball-end mill 20 also can comprise auxiliary rod 23 and the first latch 24, and one end of auxiliary rod 23 is provided with the first perforate 231.Shank section 21 is also provided with accommodating groove 211 and the first jack 212, first jack 212 is communicated with accommodating groove 211, and the first jack 212 is near one end of accommodating groove 211, wherein, accommodating groove 211 is for accommodating auxiliary rod 23, first jack 212 just to the first perforate 231, first latch 24 for being plugged in the first jack 212 and the first perforate 231.When needs use auxiliary rod 23, the other end of auxiliary rod 23 is taken out from accommodating groove 211, opens auxiliary rod 23, operated the installation and removal of titanium alloy ball-end mill 20 by auxiliary rod 23, more convenient.
Further, shank section 21 also arranges the other end of the second jack 213, second jack 213 near accommodating groove 211.Titanium alloy ball-end mill 20 also comprises the second latch 25.The other end of auxiliary rod 23 be also provided with the second perforate 232, second jack 213 just to the second perforate 232, second latch 25 for being plugged in the second jack 213 and the second perforate 232.When needs dismantle titanium alloy ball-end mill 20 from driving arrangement, take out the second latch 25, open auxiliary rod 23; When titanium alloy ball-end mill 20 is installed on driving arrangement, takes out the first latch 24, open auxiliary rod 23.In the present embodiment, the shape of the first perforate 231, first jack 212, second perforate 232 and the second jack 213 is circle, the shape in the cross section of the first latch 24 and the second latch 25 is circle, to make auxiliary rod 23 can with the first latch 24 or the second latch 25 for axle rotates.
Further, conveniently in the process of cutting, radiused cutting edge is lowered the temperature, shank section 21 is provided with first passage (not shown) and annular intake chamber (not shown), wherein, intake chamber is positioned at the sidewall of shank section, and the bottom of intake chamber is communicated with one end of first passage.Cutting portion is provided with second channel (not shown) and Cooling Holes (not shown), one end of second channel is communicated with the other end of first passage, the other end of second channel is communicated with Cooling Holes, and Cooling Holes is positioned at cutting portion one end away from shank section.By adding water at intake chamber, water is along first passage and second channel flowing, and finally cut pin sword from Cooling Holes outflow to circular arc and lower the temperature, in the present embodiment, the shape in the cross section of annular intake chamber is V-arrangement; In addition, the quantity of Cooling Holes is at least three, and at least three Cooling Holes are respectively just to the first radiused cutting edge 220, second radiused cutting edge 221 and three-arc shape cutting edge 222.
In the utility model embodiment, the end face of the other end of cutting portion arranges the first radiused cutting edge, the second radiused cutting edge and three-arc shape cutting edge, angle between first radiused cutting edge with the second radiused cutting edge is identical with the angle between three-arc shape cutting edge and the second radiused cutting edge, titanium alloy ball-end mill is cut, titanium alloy ball-end mill is more stable, is applicable to Precision Machining, in addition, first radiused cutting edge and the second radiused cutting edge surround first and enter to consider groove to be worth doing, three-arc shape cutting edge and the second radiused cutting edge surround second and enter to consider to be worth doing groove, the side face of cutting portion is provided with the first spiral cutting sword, second spiral cutting sword and the 3rd spiral cutting sword, first spiral cutting sword, described second spiral cutting sword and cutting portion surround the first chip area, first chip area and first enters to consider to be worth doing groove and is communicated with, 3rd spiral cutting sword, second spiral cutting sword and cutting portion surround the second chip area, second chip area and second enters to consider to be worth doing groove and is communicated with, first chip area and first enters to consider to be worth doing groove and forms the first channel of chip removal, second chip area and second enters to consider to be worth doing groove and forms the second channel of chip removal, by the first channel of chip removal, second channel of chip removal two channel of chip removal carries out chip removal, strengthen the chip removal performance of titanium alloy ball-end mill.
It should be noted that, preferably embodiment of the present utility model is given in description of the present utility model and accompanying drawing thereof, but, the utility model can be realized by many different forms, be not limited to the embodiment described by this description, these embodiments not as the extra restriction to the utility model content, provide the object of these embodiments be make the understanding of disclosure of the present utility model more comprehensively thorough.Further, above-mentioned each technical characteristic continues combination mutually, is formed not at above-named various embodiment, is all considered as the scope that the utility model description is recorded; Further, for those of ordinary skills, can be improved according to the above description or convert, and all these improve and convert the protection domain that all should belong to the utility model claims.
Claims (10)
1., for a precision machined titanium alloy ball-end mill, it is characterized in that, comprising:
Shank section;
Cutting portion, one end of described cutting portion is connected with described shank section, the end face of the other end of described cutting portion is provided with the first radiused cutting edge, second radiused cutting edge and three-arc shape cutting edge, described first radiused cutting edge is identical with the angle between described three-arc shape cutting edge and the second radiused cutting edge with the angle between the second radiused cutting edge, described first radiused cutting edge and the second radiused cutting edge surround first and enter to consider groove to be worth doing, described second radiused cutting edge and three-arc shape cutting edge surround second and enter to consider to be worth doing groove, the side face of described cutting portion is provided with helical first spiral cutting sword, second spiral cutting sword and the 3rd spiral cutting sword, described first spiral cutting sword is connected with described first radiused cutting edge, described second spiral cutting sword is connected with described second radiused cutting edge, described 3rd spiral cutting sword is connected with described three-arc shape cutting edge, described first spiral cutting sword, described second spiral cutting sword and cutting portion surround the first chip area, described first chip area and described first enters to consider to be worth doing groove and is communicated with, described second spiral cutting sword, described 3rd spiral cutting sword and cutting portion surround the second chip area, described second chip area and described second enters to consider to be worth doing groove and is communicated with,
Described shank section, cutting portion, the first radiused cutting edge, the second radiused cutting edge, three-arc shape cutting edge, the first spiral cutting sword, the second spiral cutting sword and be that the 3rd spiral cutting sword is formed in one, and be titanium alloy.
2. titanium alloy ball-end mill according to claim 1, is characterized in that,
The arc chord angle of described first radiused cutting edge, the second radiused cutting edge and three-arc shape cutting edge is 45 degree.
3. titanium alloy ball-end mill according to claim 1, is characterized in that,
The helical angle of described first spiral cutting sword, the second spiral cutting sword and the 3rd spiral cutting sword is 45 degree.
4. titanium alloy ball-end mill according to claim 1, is characterized in that,
Described titanium alloy ball-end mill also comprises auxiliary rod and the first latch, and one end of described auxiliary rod is provided with the first perforate;
Described shank section is also provided with accommodating groove and the first jack, described first jack is communicated with described accommodating groove, and described first jack is near one end of described accommodating groove, wherein, described accommodating groove is for accommodating described auxiliary rod, described first jack is just to described first perforate, and described first latch is for being plugged in described first jack and described first perforate.
5. titanium alloy ball-end mill according to claim 4, is characterized in that,
Described shank section also arranges the second jack, and described second jack is near the other end of described accommodating groove;
Described titanium alloy ball-end mill also comprises the second latch;
The other end of described auxiliary rod is also provided with the second perforate, and described second jack is just to described second perforate, and described second latch is for being plugged in described second jack and described second perforate.
6. titanium alloy ball-end mill according to claim 5, is characterized in that,
The shape of described first perforate, the first jack, the second perforate and the second jack is circle;
The shape in the cross section of described first latch and the second latch is circle.
7. titanium alloy ball-end mill according to claim 1, is characterized in that,
Described first spiral cutting sword, the second spiral cutting sword and/or the 3rd spiral cutting sword are provided with chip groove.
8. titanium alloy ball-end mill according to claim 1, is characterized in that,
Described shank section is provided with first passage and annular intake chamber, and wherein, described intake chamber is positioned at the sidewall of described shank section, and the bottom of described intake chamber is communicated with one end of described first passage;
Described cutting portion is provided with second channel and Cooling Holes, one end of described second channel is communicated with the other end of described first passage, the other end of described second channel is communicated with described Cooling Holes, and described Cooling Holes is positioned at described cutting portion one end away from described shank section.
9. titanium alloy ball-end mill according to claim 8, is characterized in that,
The quantity of described Cooling Holes is at least three, and described at least three Cooling Holes are respectively just to described first radiused cutting edge, the second radiused cutting edge and three-arc shape cutting edge.
10. titanium alloy ball-end mill according to claim 8, is characterized in that,
The shape in the cross section of described annular intake chamber is V-arrangement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520301868.5U CN204639283U (en) | 2015-05-12 | 2015-05-12 | A kind of for precision machined titanium alloy ball-end mill |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520301868.5U CN204639283U (en) | 2015-05-12 | 2015-05-12 | A kind of for precision machined titanium alloy ball-end mill |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204639283U true CN204639283U (en) | 2015-09-16 |
Family
ID=54092063
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520301868.5U Active CN204639283U (en) | 2015-05-12 | 2015-05-12 | A kind of for precision machined titanium alloy ball-end mill |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204639283U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105328220A (en) * | 2015-12-15 | 2016-02-17 | 常州市海力工具有限公司 | Curved surface formed tool |
-
2015
- 2015-05-12 CN CN201520301868.5U patent/CN204639283U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105328220A (en) * | 2015-12-15 | 2016-02-17 | 常州市海力工具有限公司 | Curved surface formed tool |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103722227A (en) | Indexable ball end mill for molds | |
| CN204639283U (en) | A kind of for precision machined titanium alloy ball-end mill | |
| CN202824774U (en) | Composite knife for drilling, grooving and shaving | |
| CN203316750U (en) | Boring tool for processing chain links | |
| CN105081471A (en) | Chamfer tool | |
| CN204397100U (en) | A kind of buttless thread milling cutter | |
| CN205057142U (en) | Machining tool | |
| CN204504407U (en) | Low module machine clip variable-position gear milling cutter in plate-like | |
| CN203470938U (en) | Three-blade turning tool | |
| CN202555910U (en) | Reamer | |
| CN205764065U (en) | Stepped hole drill bit | |
| CN203635959U (en) | Profiling turning blade | |
| CN203664832U (en) | Stepped shaft reamer | |
| CN203281903U (en) | Forming cutter | |
| CN202861423U (en) | Lathe tool with a plurality of blades | |
| CN202804212U (en) | Finish machining molding cutter | |
| CN204997093U (en) | A cutter for processing cell -phone casing lead angle | |
| CN204148611U (en) | Bicircular arcs oil groove milling cutter fixture | |
| CN203471016U (en) | Four-edge coarse milling cutter | |
| CN205465899U (en) | Eave tile spanner with adjustable | |
| CN204396918U (en) | A kind of numerically controlled lathe special-shaped blade | |
| CN202239849U (en) | Cutter for milling groove | |
| CN204997119U (en) | A PCD cutter for processing cell -phone casing | |
| CN204277051U (en) | Two-sided hexagonal 12 sword slabbing series cutterhead | |
| CN203227858U (en) | Compound four-blade milling cutter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 518000 5th Floor, 2046 Baihua Community Sightseeing Road, Guangming Street, Guangming District, Shenzhen City, Guangdong Province Patentee after: Shenzhen Zhishan Science and Technology Co., Ltd. Address before: 518000 Workshop 105, No. 1, Xintianhuasai Industrial Plant, Jihua Road, Bantian Street, Longgang District, Shenzhen City, Guangdong Province Patentee before: Zhi Shang Science and Technology Ltd. of Shenzhen |