CN106041609A - Feeding device of numerical control machine tool - Google Patents
Feeding device of numerical control machine tool Download PDFInfo
- Publication number
- CN106041609A CN106041609A CN201610569617.4A CN201610569617A CN106041609A CN 106041609 A CN106041609 A CN 106041609A CN 201610569617 A CN201610569617 A CN 201610569617A CN 106041609 A CN106041609 A CN 106041609A
- Authority
- CN
- China
- Prior art keywords
- guide
- catch
- feeding
- hole
- ball screw
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q7/00—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q7/00—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting
- B23Q7/06—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting by means of pushers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q7/00—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting
- B23Q7/08—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting by means of slides or chutes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q7/00—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting
- B23Q7/10—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting by means of magazines
- B23Q7/106—Arrangements for handling work specially combined with or arranged in, or specially adapted for use in connection with, machine tools, e.g. for conveying, loading, positioning, discharging, sorting by means of magazines with means to deliver a certain quantity
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Feeding Of Articles To Conveyors (AREA)
Abstract
The invention discloses a feeding device of a numerical control machine tool. The feeding device comprises a servo feeding mechanism, a guide rod provided with a guide head, a guide pipe, a storage hopper and a single selection mechanism. The guide head is fixed to the guide rod. A guide through hole is formed in the guide pipe. The guide head is mounted in the guide through hole. The servo feeding mechanism drives the guide rod, and therefore the guide head moves in the guide through hole. A discharging channel of the storage hopper is connected with the guide through hole. The storage hopper feeds one material in the guide through hole every time through the single selection mechanism. According to the feeding device, automatic discharging is achieved while automatic in-position feeding is achieved; the material switchover speed is high; guiding and feeding stability is good; the production takt is quick; production efficiency is high; labor cost is low; the automation level is high; and automatic production can be achieved easily.
Description
Technical field
The invention belongs to the parts technical field of Digit Control Machine Tool, relate to the pay-off of a kind of Digit Control Machine Tool, this feeding
Device is mainly used in the NC automatic processing equipment of axle, pipe part.
Background technology
At present, existing Digit Control Machine Tool, its discharging and feeding required time are long, cause material longer for switching time, and then
Causing production efficiency low, it is impossible to meet Production requirement, labor strength is also big simultaneously, and automatization level is the lowest, and material switches
Less stable, it is impossible to realize preferably automated production.
To this end, the pay-off of the Digit Control Machine Tool of a kind of stability and high efficiency of necessary design, to solve above-mentioned technical problem.
Summary of the invention
It is an object of the invention to provide a kind of delivery material good stability and the pay-off of efficient Digit Control Machine Tool, using should
Pay-off carries out feeding and discharging automatically, to shorten material switching time, improves production efficiency, reduce labor strength and
Improve automatization level.
In order to solve above-mentioned technical problem, the technical solution used in the present invention is: the pay-off of a kind of Digit Control Machine Tool, bag
Include servo feeding mechanism, guide bar, guide head, passage, for storing storage bin hopper and the single choice mechanism of material, described guide head
Being fixed on described guide bar, described passage is provided with guide through hole, and described guide head is loaded in described guide through hole, described
Servo feeding mechanism drives described guide bar so that described guide head moves in described guide through hole, under described storage bin hopper
Material passage is connected with described guide through hole, and described storage bin hopper sends into one in described guide through hole by described single choice mechanism every time
Part material.
Further, described servo feeding mechanism includes mounting seat, feeding servomotor, synchronous belt drive mechanism, ball
Screw mandrel and ball screw nut, described feeding servomotor and described ball screw are respectively arranged in described mounting seat, described
Feeding servomotor drives described ball screw to rotate by described synchronous belt drive mechanism, and described ball screw nut is set in
On described ball screw, described ball screw nut is connected with described guide bar.
Further, described synchronous belt drive mechanism includes the first synchronous pulley, Timing Belt and the second synchronous pulley, described
First synchronous pulley is set in the rotating shaft of described feeding servomotor, and described second synchronous pulley is set in described ball screw
One end, described Timing Belt is connected to described first synchronous pulley and the second synchronous pulley.
Further, described single choice mechanism includes mounting bracket, the first single choice cylinder, the first catch, the second single choice cylinder
With the second catch, described mounting bracket is fixed on described storage bin hopper, and described first single choice cylinder and the second single choice cylinder are respectively
Being installed in described mounting bracket, described first catch and the second catch are individually fixed in the piston rod of described first single choice cylinder
With the piston rod of described second single choice cylinder, described first catch and the second catch all can stretch into the blanking of described storage bin hopper and lead to
In road.
Further, the distance between described first catch and described second catch is equal to the width of described material.
Further, described passage is provided with opening, and this opening is connected with described guide through hole, under described storage bin hopper
Material passage is connected with described opening.
The method have the benefit that the pay-off self-feeding of the present invention also achieves automatic discharging while putting in place, because of
This material switch speed is fast, and productive temp is fast, improves production efficiency;Only need manually timing to be supplemented by material and be positioned over storage bin hopper
In can realize certain time and the most automatically process, therefore save artificial, reduce cost of labor;Automatically carry out discharging and send
Material, automatization level is high, is advantageously implemented automated production;Also lead feeding process smooth and easy stable, do not have the different of jam
Reason condition, therefore leading feeding stability might as well.
Accompanying drawing explanation
Fig. 1 is the structural representation of the pay-off of the embodiment of the present invention.
Fig. 2 is the partial structurtes schematic diagram of Fig. 1.
Fig. 3 is the top view of Fig. 2.
Fig. 4 is the left view of Fig. 2.
Fig. 5 is storage bin hopper and the structural representation of single choice mechanism.
Fig. 6 is the zoomed-in view of A in Fig. 5.
Fig. 7 is view during pan feeding state.
Fig. 8 is view during feeding waiting state.
Fig. 9 is that feeding puts in place and view during discharging.
Description of reference numerals:
Mounting seat 11, feeding servomotor the 12, first synchronous pulley 13, Timing Belt the 14, second synchronous pulley 15, ball wire
Bar 16, ball screw nut 17, guide bar 18, guide head 19, passage 20, storage bin hopper 21, single choice mechanism 22, chuck 23, thing
Material 24;
Guide post 181, guide pin bushing 182;
Mounting bracket the 221, first single choice cylinder the 222, first catch the 223, second single choice cylinder the 224, second catch 225;
Guide through hole 201, opening 202;
Blanking channel 211.
Detailed description of the invention
Below in conjunction with the accompanying drawing of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described,
Obviously, described embodiment is only a part of embodiment of the present invention rather than whole embodiments.Based in the present invention
Embodiment, the every other embodiment that those of ordinary skill in the art are obtained under not making creative work premise, all
Belong to the scope of protection of the invention.
The structure of the pay-off of the present embodiment is as shown in Figure 1.This pay-off is the position feeding of horizontal parallel parallel duplex
Structure (the most once can send two pieces material 24) simultaneously, pay-off include servo feeding mechanism, guide bar 18, guide head 19,
Passage 20, for storing storage bin hopper 21 and the single choice mechanism 22 of material 24.
With reference to Fig. 2, Fig. 3 and Fig. 4, servo feeding mechanism includes mounting seat 11, feeding servomotor 12, toothed belt transmission machine
Structure, ball screw 16 and ball screw nut 17, feeding servomotor 12 and ball screw 16 are respectively arranged in mounting seat 11,
Ball screw nut 17 is set on ball screw 16, and feeding servomotor 12 drives ball screw by synchronous belt drive mechanism
16 rotate, thus drive ball screw nut 17 to move on ball screw 16.Decision design, synchronous belt drive mechanism includes
One synchronous pulley 13, Timing Belt 14 and the second synchronous pulley 15, the first synchronous pulley 13 is set in turning of feeding servomotor 12
On axle, the second synchronous pulley 15 is set in one end of ball screw 16, and Timing Belt 14 is connected to the first synchronous pulley 13 He
Second synchronous pulley 15.Decision design, ball screw nut 17 is fixed with guide pin bushing 182, mounting seat 11 is fixed with guide post
181, guide post 181 is parallel with ball screw 16, and sleeve 182 is set on 181.One end of guide bar 18 is connected to ball screw
Nut 17, the other end is fixed with a guide head 19.Mounting seat 11 is fixed in one end of passage 20, and the other end is connected to numerical control
The chuck 23 of lathe.Being machined with a guide through hole 201 on passage 20, this guide through hole 201 is on the length direction of passage
Through, passage 20 is also processed an opening 202, this opening 202 is connected with guide through hole 201.Guide head 19 is loaded on guide
In through hole 201, servo feeding mechanism drives guide bar 18 so that guide head 19 moves in guide through hole 201.
With reference to Fig. 5 and Fig. 6, storage bin hopper 21 being machined with blanking channel 211, blanking channel 211 is connected with opening 202, storage
Material 24 in hopper 21 is by sending into material 24 in blanking channel 211 guide material through hole 201.Single choice mechanism 22 is installed on blanking
At passage 211, single choice mechanism 22 includes mounting bracket the 221, first single choice cylinder the 222, first catch the 223, second single choice cylinder
224 and second catch 225.Mounting bracket 221 is fixed on storage bin hopper 21, the first single choice cylinder 222 and the second single choice cylinder 224
Being respectively arranged in mounting bracket 221, the first catch 223 and the second catch 225 are individually fixed in the work of the first single choice cylinder 222
Stopper rod and the piston rod of the second single choice cylinder 224, the first catch 223 and the second catch 225 all can alternately stretch into storage bin hopper 21
Carrying out backgauge in blanking channel 211, wherein the distance between the first catch 223 and the second catch 225 is equal to the width of material 24.
Workflow and principle to the pay-off of the present invention are described in further detail below.
1, pan feeding state: with reference to Fig. 7, feeding servomotor 12 drives guide head 19 to rest at the left end of passage 20,
Second single choice cylinder 224 drives the second catch 225 to stretch in blanking channel 211, and the first single choice cylinder 222 drives the first catch
223 leave blanking channel 211, and a material 24 between the first catch 223 and the second catch 225 drops and enters guide through hole
In 201;
2, feeding waiting state: feeding waiting state is one-level feeding state, with reference to Fig. 8, feeding servomotor 12 works
Drive guide head 19 to move to chuck 23 direction thus promote material 24 to move to chuck 23 direction, when material 24 is pushed to folder
Time at the left side of 23, feeding servomotor 12 quits work, and now material 24 rests on and waits at the left side of chuck 23;
This one-level feeding process is to carry out in the Digit Control Machine Tool course of processing simultaneously, is not take up time process-cycle, the most greatly saves
About time of feeding;
3, feeding puts in place and discharging state: feeding puts in place and discharging state is two grades of feeding states, with reference to Fig. 9, works as chuck
After material 24 at 23 is processed, feeding servomotor 12 task driven guide head 19 continue to move to chuck 23 direction from
And continue to press on material 24 and move to chuck 23 direction, material 24 also promotes the workpiece in front to move simultaneously, the work in last front
Part is pushed out and drops in dump skip, and material 24 is pushed to position simultaneously.
So circulate according to above-mentioned steps.
To sum up, the pay-off of the present invention, it can carry out discharging and feeding automatically, and feeding also achieves while putting in place and unloads
Material, therefore material switch speed is fast, improves production efficiency;Only need manually timing that material is positioned in storage bin hopper and can be realized
Long-time processing the most automatically, therefore saves artificial, reduces cost of labor;Automatically discharging and feeding, Automated water are carried out
Flat height, is advantageously implemented automated production;Lead feeding process smooth and easy stable, do not have the abnormal conditions of jam, therefore delivery
Material stability might as well.
The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all essences in the present invention
Within god and principle, any modification, equivalent substitution and improvement etc. made, as three station feedings, four station feedings, five stations send
Material or N station feeding, should be included within the scope of the present invention.
Claims (6)
1. the pay-off of a Digit Control Machine Tool, it is characterised in that include servo feeding mechanism, be furnished with the guide of guide head (19)
Bar (18), passage (20), it is used for storing the storage bin hopper (21) of material (24) and single choice mechanism (22), on described passage (20)
Being provided with guide through hole, described guide head (19) is loaded in described guide through hole, and described servo feeding mechanism drives described guide bar
(18) so that described guide head (19) moves in described guide through hole (201), the blanking channel of described storage bin hopper (21)
(211) being connected with described guide through hole (201), described storage bin hopper (21) is each to described guide by described single choice mechanism (22)
A material (24) is sent in through hole (201).
The pay-off of a kind of Digit Control Machine Tool the most according to claim 1, it is characterised in that described servo feeding mechanism bag
Include mounting seat (11), feeding servomotor (12), synchronous belt drive mechanism, ball screw (16) and ball screw nut (17),
Described feeding servomotor (12) and described ball screw (16) are respectively arranged in described mounting seat (11), described feeding servo
Motor (12) drives described ball screw (16) to rotate by described synchronous belt drive mechanism, and described ball screw nut (17) overlaps
Being loaded on described ball screw (16), described ball screw nut (17) is connected with described guide bar (18).
The pay-off of a kind of Digit Control Machine Tool the most according to claim 2, it is characterised in that described synchronous belt drive mechanism
Including the first synchronous pulley (13), Timing Belt (14) and the second synchronous pulley (15), described first synchronous pulley (13) is set in
In the rotating shaft of described feeding servomotor (12), described second synchronous pulley (15) is set in the one of described ball screw (16)
End, described Timing Belt (14) is connected to described first synchronous pulley (13) and the second synchronous pulley (15).
The pay-off of a kind of Digit Control Machine Tool the most according to claim 1, it is characterised in that described single choice mechanism (22) is wrapped
Include mounting bracket (221), the first single choice cylinder (222), the first catch (223), the second single choice cylinder (224) and the second catch
(225), described mounting bracket (221) is fixed on described storage bin hopper (21), described first single choice cylinder (222) and the second single choice
Cylinder (224) is respectively arranged in described mounting bracket (221), and described first catch (223) and the second catch (225) are solid respectively
Piston rod and the piston rod of described second single choice cylinder (224), described first catch due to described first single choice cylinder (222)
(223) and the second catch (225) all can stretch in the blanking channel of described storage bin hopper (21).
The pay-off of a kind of Digit Control Machine Tool the most according to claim 4, it is characterised in that described first catch (223)
And the distance between described second catch (225) is equal to the width of described material (24).
The pay-off of a kind of Digit Control Machine Tool the most according to claim 1, it is characterised in that described passage sets on (20)
Opening (202), this opening (202) is had to connect with described guide through hole (201), the blanking channel (211) of described storage bin hopper (21)
It is connected with described opening.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201610569617.4A CN106041609A (en) | 2016-07-18 | 2016-07-18 | Feeding device of numerical control machine tool |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201610569617.4A CN106041609A (en) | 2016-07-18 | 2016-07-18 | Feeding device of numerical control machine tool |
Publications (1)
Publication Number | Publication Date |
---|---|
CN106041609A true CN106041609A (en) | 2016-10-26 |
Family
ID=57187969
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201610569617.4A Pending CN106041609A (en) | 2016-07-18 | 2016-07-18 | Feeding device of numerical control machine tool |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN106041609A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107511432A (en) * | 2017-09-20 | 2017-12-26 | 浙江默客机电有限公司 | A kind of feed arrangement of mahjong table leg process equipment |
CN109108712A (en) * | 2018-08-07 | 2019-01-01 | 天长市永鑫制冷设备有限公司 | A kind of mandril of air conditioner parts material-pulling device |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1338381A2 (en) * | 2002-02-15 | 2003-08-27 | BIESSE S.p.A. | Machine for machining panels of wood or similar |
CN103692484A (en) * | 2013-12-16 | 2014-04-02 | 浙江大学 | Pearl holing machine |
CN204075852U (en) * | 2014-08-22 | 2015-01-07 | 宁波铝宏汽车零部件有限公司 | Axle class feed arrangement |
CN204194812U (en) * | 2014-11-07 | 2015-03-11 | 江西三锐精工有限公司 | A kind of lathe feeding device |
CN204777598U (en) * | 2015-07-12 | 2015-11-18 | 浙江工商职业技术学院 | Blowing device of bar |
CN205147941U (en) * | 2015-10-26 | 2016-04-13 | 池州市大千科技有限公司 | Autoloading clamping device of drill bit processing |
CN205852377U (en) * | 2016-07-18 | 2017-01-04 | 佛山市春莱机械设备有限公司 | The pay-off of Digit Control Machine Tool |
-
2016
- 2016-07-18 CN CN201610569617.4A patent/CN106041609A/en active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1338381A2 (en) * | 2002-02-15 | 2003-08-27 | BIESSE S.p.A. | Machine for machining panels of wood or similar |
CN103692484A (en) * | 2013-12-16 | 2014-04-02 | 浙江大学 | Pearl holing machine |
CN204075852U (en) * | 2014-08-22 | 2015-01-07 | 宁波铝宏汽车零部件有限公司 | Axle class feed arrangement |
CN204194812U (en) * | 2014-11-07 | 2015-03-11 | 江西三锐精工有限公司 | A kind of lathe feeding device |
CN204777598U (en) * | 2015-07-12 | 2015-11-18 | 浙江工商职业技术学院 | Blowing device of bar |
CN205147941U (en) * | 2015-10-26 | 2016-04-13 | 池州市大千科技有限公司 | Autoloading clamping device of drill bit processing |
CN205852377U (en) * | 2016-07-18 | 2017-01-04 | 佛山市春莱机械设备有限公司 | The pay-off of Digit Control Machine Tool |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107511432A (en) * | 2017-09-20 | 2017-12-26 | 浙江默客机电有限公司 | A kind of feed arrangement of mahjong table leg process equipment |
CN109108712A (en) * | 2018-08-07 | 2019-01-01 | 天长市永鑫制冷设备有限公司 | A kind of mandril of air conditioner parts material-pulling device |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN203863219U (en) | Metal tubular product laser cutting automatic feeding and discharging mechanism | |
CN203592350U (en) | Processing control device for tubular parts and rod parts | |
CN202272493U (en) | Turning type material conveying device for conveying rod-shaped materials | |
CN109676013A (en) | A kind of new automatic hole punched device with tubing vision-based detection | |
US10537930B1 (en) | Automatic machining device for shaft body | |
CN108620930B (en) | Full-automatic bar processing machine tool | |
CN102502238B (en) | Overturning type feeding device for conveying rod-like material | |
CN103658688B (en) | A kind of automatic lathe discharging mechanism laggard, rear | |
CN106041609A (en) | Feeding device of numerical control machine tool | |
KR101533616B1 (en) | Exhaust system for the automatic supply of CNC | |
CN105537431A (en) | Machining equipment used for riveting and fixing ends of steel ropes and threaded rods | |
CN105127358A (en) | Automatic material feeding and discharging device | |
CN205852377U (en) | The pay-off of Digit Control Machine Tool | |
CN201913267U (en) | Automatic drilling machine | |
CN103785904A (en) | Internal thread tapping method of multi-station sleeve | |
CN106002302A (en) | Automatic assembly line of hollow guide rail | |
CN210412562U (en) | Automatic feeding and discharging system of special numerical control automatic lathe for bearing roller | |
CN205237083U (en) | Automatic unloading mechanism of going up of lathe | |
CN107263187B (en) | Automatic chamfer milling equipment | |
CN202123253U (en) | Rear feeding mechanism for automatic lathe | |
CN216729577U (en) | Automatic turning equipment for round bar | |
CN209754671U (en) | Automatic feeding device for cylindrical parts | |
CN211516386U (en) | Laser cutting machine's frame | |
CN209095101U (en) | Combine loading and unloading lathe | |
CN114952316A (en) | Processing line for output shaft of double-line type isolator |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
RJ01 | Rejection of invention patent application after publication |
Application publication date: 20161026 |
|
RJ01 | Rejection of invention patent application after publication |