CN106792392A - A kind of horn magnetic circuit structure and its assemble method - Google Patents

A kind of horn magnetic circuit structure and its assemble method Download PDF

Info

Publication number
CN106792392A
CN106792392A CN201710032206.6A CN201710032206A CN106792392A CN 106792392 A CN106792392 A CN 106792392A CN 201710032206 A CN201710032206 A CN 201710032206A CN 106792392 A CN106792392 A CN 106792392A
Authority
CN
China
Prior art keywords
magnet
washer
magnetic circuit
yoke
circuit structure
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.)
Pending
Application number
CN201710032206.6A
Other languages
Chinese (zh)
Inventor
戴辉华
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sunway Communication Jiangsu Co Ltd
Original Assignee
Shenzhen Sunway Communication Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shenzhen Sunway Communication Co Ltd filed Critical Shenzhen Sunway Communication Co Ltd
Priority to CN201710032206.6A priority Critical patent/CN106792392A/en
Publication of CN106792392A publication Critical patent/CN106792392A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/06Loudspeakers
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R31/00Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/02Details
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2400/00Loudspeakers
    • H04R2400/11Aspects regarding the frame of loudspeaker transducers

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Manufacturing & Machinery (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)

Abstract

The invention discloses a kind of horn magnetic circuit structure and its assemble method, horn magnetic circuit structure includes washer, magnet and yoke, the yoke includes an accommodating chamber, the washer includes washer main body and marginal texture, the washer main body is the cavity body structure of one end open, stretches out to form the marginal texture from the edge of opening of the cavity body structure;The marginal texture is located in the accommodating chamber, and the magnet is located in the washer main body.Fixed magnet and washer are distinguished by the cavity body structure and marginal texture of washer, can prevent larger relative displacement between any two, to ensure washer, magnet and the concentricity of yoke, be conducive to improving the yield of loudspeaker finished product;First assembled when being assembled to horn magnetic circuit and magnetized afterwards, can effectively prevent in the assembling process of magnet that polarity is anti-loaded, so as to ensure the phase equalization of loudspeaker finished product.

Description

A kind of horn magnetic circuit structure and its assemble method
Technical field
The present invention relates to loudspeaker technical field, more particularly to a kind of horn magnetic circuit structure and its assemble method.
Background technology
As shown in figure 1, existing Microspeaker generally comprises vibrating diaphragm, voice coil loudspeaker voice coil, washer, magnet, yoke, framework and pad, such as Shown in Fig. 2, the magnetic circuit part of loudspeaker mainly includes washer, magnet and yoke.When the assembling of horn magnetic circuit is carried out, first not Magnetic magnet is magnetized using special magnetizing equipment, it is taken magnetic, then the gluing water on yoke, by The magnet for magnetizing is bonded on yoke, and finally the another side again in magnet stamps glue and washer is fitted together, glue curing After washer, magnet and yoke can be made to be strongly adhered to together.Naked eyes can not recognize the polarity of magnet, institute during due to man-made assembly To be easy to the anti-loaded situation of polarity occur, if magnetic circuit part polarity is anti-loaded, then being assembled into when loudspeaker work can produce not Same phase, the tonequality to loudspeaker has undesirable effect.In addition, being all to carry out artificial contraposition dress when magnetic circuit assembling is carried out Match somebody with somebody, it is difficult to ensure that the concentricity of yoke, magnet and washer, and glue is in the curing process because the mobility of itself is held very much The eccentric phenomena of magnet and washer is easily caused, the performance of loudspeaker is finally influenceed.
The content of the invention
The technical problems to be solved by the invention are:A kind of concentricity that not only can guarantee that yoke, magnet and washer is provided but also Horn magnetic circuit structure and its assemble method that magnet polarities are anti-loaded can be prevented.
In order to solve the above-mentioned technical problem, the technical solution adopted by the present invention is:
A kind of horn magnetic circuit structure, including washer, magnet and yoke, the yoke include an accommodating chamber, the washer bag Include washer main body and marginal texture, the washer main body has the cavity body structure of opening for one end, the washer main body is from opening Stretch out to form the marginal texture;The marginal texture is arranged in the accommodating chamber, and the magnet is arranged at the chamber In body structure.
Another technical scheme of the invention is:
A kind of assemble method based on horn magnetic circuit structure, including:Magnet is installed in the cavity body structure of washer main body; The washer main body that magnet will be equiped with is contained in the accommodating chamber of yoke;Then magnet is magnetized using magnetizing equipment, is obtained Obtain the horn magnetic circuit structure.
The beneficial effects of the present invention are:Magnet is contained in cavity body structure, can be reduced between magnet and washer Skew, marginal texture is set on washer and can be used to be fixed on washer and magnet in the accommodating chamber of yoke, is prevented larger Skew, to ensure washer, magnet and the concentricity of yoke;When horn magnetic circuit is assembled, after washer, magnet and yoke are assembled again Magnetic structure is magnetized, magnet polarities can be prevented anti-loaded, it is ensured that the phase of loudspeaker unit is consistent, can greatly improve loudspeaker The yield of finished product.
Brief description of the drawings
Fig. 1 is the Structure explosion diagram of the loudspeaker of prior art;
Fig. 2 is the explosive view of the horn magnetic circuit structure of prior art;
Fig. 3 is the explosive view of the horn magnetic circuit structure of the embodiment of the present invention one;
Fig. 4 is the assembling flow path figure of the horn magnetic circuit structure of the embodiment of the present invention one.
Label declaration:
1st, washer;2nd, magnet;3rd, yoke;11st, washer main body;12nd, marginal texture;31st, accommodating chamber.
Specific embodiment
It is to describe technology contents of the invention, the objects and the effects in detail, below in conjunction with implementation method and coordinates attached Figure is explained.
The design of most critical of the present invention is:Magnet is contained in washer to prevent magnet from larger skew occurring, while Marginal texture is set on washer washer is fixed in the accommodating chamber of yoke, to ensure magnet, washer and the concentricity of yoke.
Fig. 3, a kind of horn magnetic circuit structure, including washer, magnet and yoke are refer to, the yoke includes an accommodating chamber, The washer includes washer main body and marginal texture, and the washer main body has the cavity body structure of opening, the washer for one end Main body extends to form the marginal texture from outward opening;The marginal texture is arranged in the accommodating chamber, and the magnet sets It is placed in the cavity body structure.
Knowable to foregoing description, the beneficial effects of the present invention are:Divided by the cavity body structure and marginal texture of washer Other fixed magnet and washer, can prevent larger relative displacement between any two, to ensure the concentric of washer, magnet and yoke Degree, is conducive to improving the yield of loudspeaker finished product.
Further, the cavity body structure is identical with the shapes and sizes difference of the magnet.
Seen from the above description, cavity body structure can just accommodate magnet, and magnet preferably can be positioned, and prevent hair Raw skew, to ensure the concentricity of magnet and washer, improves the performance of loudspeaker.
Further, phase is distinguished in the outward flange of the marginal texture with the shapes and sizes of the cross-sectional area of the accommodating chamber Together.
Seen from the above description, marginal texture can just be contained in the accommodating chamber of yoke, can prevent washer relative to Yoke shifts, and to ensure the concentricity of washer, magnet and yoke three, improves the performance of loudspeaker.
Further, the shape of the cavity body structure and magnet is cylinder.
Seen from the above description, cavity body structure and Magnet design are cylinder, are conducive to provide uniform and stable magnetic field.
Further, the outer peripheral of the marginal texture be shaped as circle, and the accommodating chamber is shaped as cylinder.
Seen from the above description, marginal texture may be designed as circle, certainly also dependent on needing to be designed as other shapes, As long as washer can be completely fixed in the accommodating chamber of yoke.
Further, the first adhesive linkage is provided between the washer and magnet, second is provided between the magnet and yoke Adhesive linkage.
Seen from the above description, in order to preferably fix washer, magnet and yoke, can be bonded by adhesive linkage.
Fig. 4 is refer to, another technical scheme of the invention is:
A kind of assemble method based on horn magnetic circuit structure, including:Magnet is installed in the cavity body structure of washer main body; The washer main body that magnet will be equiped with is contained in the accommodating chamber of yoke;Then magnet is magnetized using magnetizing equipment, is obtained Obtain the horn magnetic circuit structure.
Seen from the above description, when horn magnetic circuit structure is assembled, first assemble and magnetize afterwards, can avoid filling magnet polarities Instead so that the phase of loudspeaker unit is consistent, production yield is improved.
Further, the first adhesive linkage is set in the bottom of cavity body structure, by first adhesive linkage by the magnet One end is fixed in washer main body.
Seen from the above description, magnet is fixed on washer by the first adhesive linkage, can prevents from coming off, it is ensured that loudspeaker Performance, the first adhesive linkage can be realized by smearing one layer of glue.
Further, the second adhesive linkage is set in the bottom of the accommodating chamber of yoke, by second adhesive linkage by magnet The other end is fixed on yoke.
Seen from the above description, can prevent washer and magnet from being come off from yoke by the second adhesive linkage, it is ensured that loudspeaker Performance, the second adhesive linkage can also be realized by smearing one layer of glue.
Embodiment one
Fig. 3 is refer to, embodiments of the invention one are:A kind of horn magnetic circuit structure, including washer 1, magnet 2 and yoke 3, The washer 1 includes washer main body 11 and marginal texture 12, and the washer main body 11 is the cavity body structure of one end open, the magnetic Iron 2 is located in the cavity body structure, it is preferred that cavity body structure can just accommodate the shape of the cavity of the magnet 2, i.e. cavity body structure It is shape, the shape of size and magnet 2, in the same size, can prevent magnet from position occurring relative to washer and offset.In order that magnet 2 Preferably it is fixed on washer 1, the first adhesive linkage is provided with the bottom of cavity body structure, can be by magnet by first adhesive linkage 2 are securely fixed on washer, prevent from coming off.In the present embodiment, magnet 2 and cavity body structure are cylinder, can produce stabilization Uniform magnetic field, the external diameter of magnet 2 is consistent with the diameter of cavity body structure, and the height of magnet 2 is the depth of cavity body structure.
Stretch out to form the marginal texture 12 from the edge of opening of the cavity body structure, the yoke 3 includes that one holds Receive chamber 31, the marginal texture 12 can be contained in the accommodating chamber 31, it is preferred that the outer peripheral shape of the marginal texture 12 Shape, more than the shape with the cross section of the accommodating chamber 31, in the same size, washer 1 can be prevented to be subjected to displacement relative to yoke.This In embodiment, the accommodating chamber 31 of yoke 3 is also a cylinder, and marginal texture 12 may be designed as circle, naturally it is also possible to be designed as Other shapes, such as gear shape, square etc., offset as long as washer 1 being fixed in yoke and prevent it from position occurring.When Accommodating chamber 31 for cylinder, marginal texture 12 for it is circular when, the outer peripheral diameter of marginal texture 12 and the diameter of accommodating chamber 31 Unanimously.In order that magnet and washer are preferably fixed on yoke 3, the second adhesive linkage is provided with yoke 3, by described second Bonding can prevent washer 1 and the entirety of magnet 2 from being come off from yoke 3, advantageously ensure that the performance of loudspeaker.
In the present embodiment, by the mutual cooperation of the washer main body 11 and marginal texture 12 of washer 1, it is ensured that washer 1, magnetic Iron 2 and the concentricity of the three of yoke 3, improve the yield of loudspeaker finished product.
The present embodiment further relates to a kind of assemble method of horn magnetic circuit structure, mainly comprises the following steps:
Magnet 2 is installed in washer main body 11 first, is specifically included:The first adhesive linkage is set in the bottom of cavity body structure, One end of the magnet 2 is fixed in washer main body 11 by first adhesive linkage, the first adhesive linkage can be bonded adhesives Water, naturally it is also possible to be other bonded structures.
Then the washer 1 that magnet 2 will be equiped with is contained in yoke, is specifically included:In the bottom of the accommodating chamber 31 of yoke 3 If the second adhesive linkage, the other end of magnet 2 is fixed on yoke 3 by second adhesive linkage, second adhesive linkage But being bonded glue or other has bonded structure.
Finally magnetized using magnetizing equipment, the magnetic conductivity of washer 1 and yoke 3 will not be produced to the effect that magnetizes of magnet 2 Raw influence, and the polarity of magnet 2 can be as needed set, can effectively prevent from filling polarity in the assembling process of magnet Instead, so as to ensure the phase equalization of loudspeaker finished product.
In sum, the present invention is provided a kind of horn magnetic circuit structure and its assemble method, by the cavity body structure of washer Fixed magnet and washer are distinguished with marginal texture, can prevent larger relative displacement between any two, to ensure washer, magnetic The concentricity of iron and yoke, is conducive to improving the yield of loudspeaker finished product;First assembled when being assembled to horn magnetic circuit and magnetized afterwards, can It is in the assembling process of magnet that polarity is anti-loaded effectively to prevent, so as to ensure the phase equalization of loudspeaker finished product.
Embodiments of the invention are the foregoing is only, the scope of the claims of the invention is not thereby limited, it is every to utilize this hair The equivalents that bright specification and accompanying drawing content are made, or the technical field of correlation is directly or indirectly used in, similarly include In scope of patent protection of the invention.

Claims (9)

1. a kind of horn magnetic circuit structure, including washer, magnet and yoke, the yoke include an accommodating chamber, it is characterised in that institute Stating washer includes washer main body and marginal texture, and the washer main body has the cavity body structure of opening, the washer master for one end Body extends to form the marginal texture from outward opening;The marginal texture is arranged in the accommodating chamber, and the magnet is set In in the cavity body structure.
2. horn magnetic circuit structure according to claim 1, it is characterised in that the cavity of the cavity body structure and the magnet Shapes and sizes difference it is identical.
3. horn magnetic circuit structure according to claim 1, it is characterised in that the outward flange of the marginal texture and the appearance Receive chamber cross-sectional area shapes and sizes difference it is identical.
4. horn magnetic circuit structure according to claim 2, it is characterised in that the shape of the cavity body structure and magnet is Cylinder.
5. horn magnetic circuit structure according to claim 3, it is characterised in that the outer peripheral of the marginal texture is shaped as Circle, the accommodating chamber is shaped as cylinder.
6. the horn magnetic circuit structure according to claim 1-5 any one, it is characterised in that between the washer and magnet The first adhesive linkage is provided with, the second adhesive linkage is provided between the magnet and yoke.
7. a kind of assemble method of the horn magnetic circuit structure based on described in claim 1-6 any one, it is characterised in that bag Include:Magnet is installed in the cavity body structure of washer main body;The washer main body that magnet will be equiped with is contained in the accommodating chamber of yoke It is interior;Then magnet is magnetized using magnetizing equipment, obtains the horn magnetic circuit structure.
8. the assemble method of horn magnetic circuit structure according to claim 7, it is characterised in that set in the bottom of cavity body structure , be fixed in washer main body for one end of the magnet by first adhesive linkage by the first adhesive linkage.
9. the assemble method of horn magnetic circuit structure according to claim 8, it is characterised in that at the bottom of the accommodating chamber of yoke Portion sets the second adhesive linkage, and the other end of magnet is fixed on yoke by second adhesive linkage.
CN201710032206.6A 2017-01-16 2017-01-16 A kind of horn magnetic circuit structure and its assemble method Pending CN106792392A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710032206.6A CN106792392A (en) 2017-01-16 2017-01-16 A kind of horn magnetic circuit structure and its assemble method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710032206.6A CN106792392A (en) 2017-01-16 2017-01-16 A kind of horn magnetic circuit structure and its assemble method

Publications (1)

Publication Number Publication Date
CN106792392A true CN106792392A (en) 2017-05-31

Family

ID=58946954

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710032206.6A Pending CN106792392A (en) 2017-01-16 2017-01-16 A kind of horn magnetic circuit structure and its assemble method

Country Status (1)

Country Link
CN (1) CN106792392A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110536224A (en) * 2019-07-12 2019-12-03 国光电器股份有限公司 The assemble method of magnetic circuit structure for loudspeaker
CN110620985A (en) * 2019-09-27 2019-12-27 厦门三立电子有限公司 Small neodymium iron boron strip magnetic bonding process
CN113473337A (en) * 2021-07-14 2021-10-01 斯贝克电子(嘉善)有限公司 A kind of loudspeaker

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102256196A (en) * 2011-01-26 2011-11-23 歌尔声学股份有限公司 Micro moving-coil electroacoustic transducer and assembling method thereof
US20120051575A1 (en) * 2010-08-26 2012-03-01 Hiroshi Akino Condenser Microphone Unit and Condenser Microphone
CN103079135A (en) * 2013-01-08 2013-05-01 深圳市韶音科技有限公司 Bone-conduction headset device with single magnet and processing method thereof
CN204795582U (en) * 2015-07-17 2015-11-18 歌尔声学股份有限公司 A magnetic circuit and speaker for speaker
CN205142518U (en) * 2015-12-03 2016-04-06 歌尔声学股份有限公司 Loudspeaker
CN105491491A (en) * 2016-01-26 2016-04-13 深圳市赛音微电子有限公司 Loudspeaker and magnet assembly thereof
CN205179356U (en) * 2015-12-10 2016-04-20 厦门信荣达科技有限公司 Improve bearing structure's speaker
CN205491115U (en) * 2016-01-20 2016-08-17 合肥宏立电子有限公司 Prevent that audio amplifier magnetism that rocks returns structure
CN206413187U (en) * 2017-01-16 2017-08-15 深圳市信维通信股份有限公司 A kind of horn magnetic circuit structure

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120051575A1 (en) * 2010-08-26 2012-03-01 Hiroshi Akino Condenser Microphone Unit and Condenser Microphone
CN102256196A (en) * 2011-01-26 2011-11-23 歌尔声学股份有限公司 Micro moving-coil electroacoustic transducer and assembling method thereof
CN103079135A (en) * 2013-01-08 2013-05-01 深圳市韶音科技有限公司 Bone-conduction headset device with single magnet and processing method thereof
CN204795582U (en) * 2015-07-17 2015-11-18 歌尔声学股份有限公司 A magnetic circuit and speaker for speaker
CN205142518U (en) * 2015-12-03 2016-04-06 歌尔声学股份有限公司 Loudspeaker
CN205179356U (en) * 2015-12-10 2016-04-20 厦门信荣达科技有限公司 Improve bearing structure's speaker
CN205491115U (en) * 2016-01-20 2016-08-17 合肥宏立电子有限公司 Prevent that audio amplifier magnetism that rocks returns structure
CN105491491A (en) * 2016-01-26 2016-04-13 深圳市赛音微电子有限公司 Loudspeaker and magnet assembly thereof
CN206413187U (en) * 2017-01-16 2017-08-15 深圳市信维通信股份有限公司 A kind of horn magnetic circuit structure

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110536224A (en) * 2019-07-12 2019-12-03 国光电器股份有限公司 The assemble method of magnetic circuit structure for loudspeaker
CN110620985A (en) * 2019-09-27 2019-12-27 厦门三立电子有限公司 Small neodymium iron boron strip magnetic bonding process
CN110620985B (en) * 2019-09-27 2020-08-25 厦门三立电子有限公司 Small neodymium iron boron strip magnetic bonding process
CN113473337A (en) * 2021-07-14 2021-10-01 斯贝克电子(嘉善)有限公司 A kind of loudspeaker

Similar Documents

Publication Publication Date Title
CN106792392A (en) A kind of horn magnetic circuit structure and its assemble method
CN103581807B (en) Coil-moving speaker
CN205987363U (en) Electroacoustic transducer
CN206413187U (en) A kind of horn magnetic circuit structure
CN104038854B (en) A kind of Novel portable sound box
HK1114034A1 (en) Production method for cloth and solid piece assembly
CN205901840U (en) Waterproof structure of mobile phone touch screen
CN201585119U (en) Loudspeaker
CN105626649A (en) Decoration screw
JP2010524781A5 (en) Composite comprising a ring, a foil and a lid, a preliminary composite therefor, a method for producing a composite and a method for producing a container
CN204263635U (en) A kind of packing carton lower cover shaping mechanism
US20220038823A1 (en) Speaker module
CN105792080B (en) Coaxial point sound source magnetic circuit device and the loudspeaker with the magnetic circuit device
CN209462523U (en) A kind of sound chamber BOX structure
CN205408143U (en) Automobile loudspeaker
CN203933330U (en) A kind of front reed of voice coil motor
CN209314085U (en) A kind of Microspeaker with inside and outside voice coil structure
CN208469108U (en) A kind of polybag repair outfit
CN202565590U (en) Shell structure for electronic product
CN207099318U (en) The compound module of water-proof sound-transmitting
CN206433064U (en) The assembling structure and camera module of a kind of camera lens and carrier
CN206237595U (en) It is easy to the horn single body and its voice coil loudspeaker voice coil vibrating diaphragm of assembling
CN206136280U (en) Sound membrane module
CN205793277U (en) The mounting structure of a kind of Microspeaker upper cover and pedestal and Microspeaker
CN208623902U (en) A kind of horn structure of ultra-thin Baffle Box of Bluetooth

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
TA01 Transfer of patent application right
TA01 Transfer of patent application right

Effective date of registration: 20170908

Address after: 213000 No. 399 Ming Hu Road, Jintan District, Jiangsu, Changzhou

Applicant after: SUNWAY COMMUNICATION (JIANGSU) Co.,Ltd.

Address before: 518000 Guangdong Province, Shenzhen city Baoan District manhole Street Xihuan Road No. 1013, building B, A

Applicant before: SHENZHEN SUNWAY COMMUNICATION Co.,Ltd.

RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20170531