CN108372206A - A kind of Integral elastic material guide device of oblique milling copper rod - Google Patents

A kind of Integral elastic material guide device of oblique milling copper rod Download PDF

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Publication number
CN108372206A
CN108372206A CN201810286331.4A CN201810286331A CN108372206A CN 108372206 A CN108372206 A CN 108372206A CN 201810286331 A CN201810286331 A CN 201810286331A CN 108372206 A CN108372206 A CN 108372206A
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CN
China
Prior art keywords
copper rod
pedestal
bearing
guide device
material guide
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Pending
Application number
CN201810286331.4A
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Chinese (zh)
Inventor
王宝雨
林龙飞
刘晋平
杨翠萍
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University of Science and Technology Beijing USTB
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University of Science and Technology Beijing USTB
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Priority to CN201810286331.4A priority Critical patent/CN108372206A/en
Publication of CN108372206A publication Critical patent/CN108372206A/en
Pending legal-status Critical Current

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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21BROLLING OF METAL
    • B21B39/00Arrangements for moving, supporting, or positioning work, or controlling its movement, combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B39/14Guiding, positioning or aligning work

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rolling Contact Bearings (AREA)

Abstract

The present invention relates to metal forming techniques and equipment technology field; provide a kind of Integral elastic material guide device of oblique milling copper rod; mainly it is made of rack, elastic support unit body and protection pipe; since device is made of several independent elastic support unit bodies; its interchangeability is high, applicability is good, can be applied to the copper rod charging of different length;Device is annular integral vertical type pedestal, has the characteristics that compact-sized, stiffness by itself is high, small to rack active force;Since copper rod and device are Elastic Contact, the present apparatus has buffering absorbing effect, can reduce copper rod and be deformed because of impact, reduces impact noise.The present invention has many advantages, such as that versatility is good, compact-sized, rigidity is high, on-site noise is low, copper rod deformation is small, bearing life is long.

Description

A kind of Integral elastic material guide device of oblique milling copper rod
Technical field
The present invention relates to metal forming technique and equipment technology field, more particularly to a kind of monoblock type of oblique milling copper rod Elastic material guide device.
Background technology
Anodic phosphorous copper balls are widely used and the industrial circles such as printed circuit board, hardware, decoration as plating anode material. Because room temperature oblique milling technology has, production efficiency is high, energy consumption cost is low, stable quality, product plating performance is excellent, the mode of production is clear The advantages that clean pollution-free, has obtained universal application now, becomes the important technological means of production anodic phosphorous copper balls.
Currently, the technique of oblique milling anodic phosphorous copper balls is:Copper bar by continuous casting is transported with plate-like to scene, is used first Flying shearing machine are cut out, then charging support device is imported into after straightener is aligned, and then enter to expect skew rolling mill, final greenhouse oblique milling sun Pole phosphorous copper balls.In oblique roll process, the length of pan feeding copper rod is longer, and material head loss is fewer, and stock utilization is higher;Oblique milling Rotating speed is bigger, and production efficiency is higher, so the length of general oblique milling copper rod is 3 ~ 5m, rotating speed is about 600 ~ 900r/min.
Due to the radial high speed rotation of long thin copper bar work, the compound motion of axial straight-line feed, copper rod and charging support device There are high speed impact, existing security closed type low noise oblique milling copper ball feeding equipment(CN102039360.A), due to feed roller System and copper rod are rigid contacts, so copper rod is easy the low pair of high frequency in charging support device and gets rid of pendulum, cause production scene noise Greatly, the problems such as piece surface serious wear that copper rod self-deformation is serious, is contacted with copper rod, to formed noise pollution seriously, The problems such as copper ball surface quality reduces, pan feeding copper rod length shortens and milling train rotating speed reduces, roller system short life.Simultaneously as its The pedestal of each unit also non-integral type, leads to that structure is not compact, device rigidity is low.
Invention content
The purpose of the present invention is exactly to have overcome the deficiencies of the prior art and provide a kind of Integral elastic guide of oblique milling copper rod Device is made of several independent elastic support unit bodies, and interchangeability is good, can be applied to the copper rod charging of different length; The device is Elastic Contact with copper rod, has buffering absorbing effect, can prevent copper rod from being deformed because of rigid shock, can reduce charging When impact noise;It is good, compact-sized with versatility, rigidity is high, on-site noise is low, copper rod deformation small, bearing life length etc. Advantage.
Technical scheme is as follows:
A kind of Integral elastic material guide device of oblique milling copper rod, including rack, several flexible feed support unit bodies, protection pipe; Several described flexible feed support unit bodies are sequentially arranged along the rack, and the flexible feed support unit body includes charging Supporting mechanism, pedestal;The pedestal is fixedly connected on rack;The charging supporting mechanism is connect with the pedestal spring, copper rod It is contained in several flexible feed support unit bodies and the protection pipe is formed by confined space, realize copper rod and institute State the Elastic Contact of the Integral elastic material guide device of oblique milling copper rod.
Further, the pedestal is annular integral vertical type pedestal, and it is equal to be equipped with 3 circumferential directions in the pedestal axial direction intermediate ends The installation stepped hole of even arrangement, 3 charging supporting mechanisms are circumferentially staggered by the installation stepped hole in the pedestal 120 ° are evenly arranged.
Further, the charging supporting mechanism includes bearing, bearing jackshaft, supporting bearing base, and bearing is mounted on branch It supports on the inside of bearing block;It is described charging supporting mechanism assembly method be:Bearing and supporting bearing base are heated to 100 ° -130 °, Or bearing jackshaft 15 is soaked into liquid nitrogen, with the mode elastic conjunction of the cold hole heat of axis.
Further, the bearing is the bearing of the included lubrication of totally enclosed type, be deep groove ball bearing, roller bearing or Any one of universal ball bearing.
Further, hollow end cap is equipped with by bolt on two axial end faces of the pedestal, be used for the base The inner cavity closing of seat;It is covered in the hollow end and connecting flange is installed by bolt and nut, passed through on the outside of the connecting flange Welding or holding screw are cased with the protection pipe, and the flexible feed support unit body is made to close, and eliminate because of copper rod high-speed motion The security risk brought.
Further, the charging supporting mechanism is installed on by butterfly spring group in the installation stepped hole of the pedestal, The butterfly spring group is separately mounted to the medial and lateral of the installation stepped hole, the spring bearing using pairing combination 2 locking nuts are installed in the outer end of seat, to precompressed butterfly spring group.
Further, the annular diameters of the pedestal are 150mm, outer annular diameter 250mm, axial width 120mm;Butterfly The stroke of groups of springs is 1 ~ 1.5mm, and load is 1 ~ 2t.The fit clearance of butterfly spring group and supporting bearing base is 1.3mm, with base The fit clearance 1.5mm of seat.
Further, the flexible feed support unit body is 5, the spacing of each flexible feed support unit body For 500 ~ 800mm, the pedestal is fixed in the rack by bolt.
Further, the rack is installed on the ground by foundation bolt, height and the skew rolling mill feeding mouth of rack It is highly consistent.
Beneficial effects of the present invention are:Versatility is good, can be applied to the copper rod charging of different length;With buffering absorbing Effect, can prevent copper rod from being deformed because of rigid shock, can reduce impact noise when charging;Base construction is compact, stiffness by itself It is high, small to rack active force;Abrasion reduces, and bearing life is high.
Description of the drawings
Fig. 1 show a kind of Integral elastic material guide device general structure schematic diagram of oblique milling copper rod of the embodiment of the present invention.
Fig. 2 show flexible feed support unit body structural schematic diagram.
Fig. 3 show the half section structure diagram of flexible feed support unit body.
Fig. 4 show charging supporting mechanism structural schematic diagram.
Fig. 5 show base construction schematic diagram.
Fig. 6 show pedestal half section structure diagram.
Fig. 7 show rack construction schematic diagram.
In figure:1. copper rod;2. elastic feeding support unit body;3. protection pipe;4. rack;5. connecting flange;6. hollow end Lid;7. pedestal;8. bearing;9. supporting bearing base;10. locking nut;11. butterfly spring group;12. bearing jackshaft.
Specific implementation mode
The specific embodiment of the invention is described in detail below in conjunction with specific attached drawing.It should be noted that in following embodiments The combination of the technical characteristic or technical characteristic of description is not construed as isolated, they can be combined with each other to reach To superior technique effect.In the attached drawing of following embodiments, identical label that each attached drawing occurs represent identical feature or Person's component can be applied in different embodiments.
It is the preferred embodiment of the present invention below, it should be noted that the design parameter in embodiment can be according to reality It needs to be determined that being not intended to limit the present invention.Protection scope of the present invention, is subject to claim.
As shown in Figure 1,1 long 3000mm of copper rod, diameter of phi 25mm, a kind of monoblock type bullet of oblique milling copper rod of the embodiment of the present invention Property material guide device, including rack 4, flexible feed support unit body 2 and protection pipe 3, rack 4 is mounted on ground by foundation bolt On, the height of rack 4 is highly consistent with skew rolling mill feeding mouth, and the spacing of each flexible feed support unit body 2 is 500 ~ 800mm And pedestal 7 is fixed in rack 4 by bolt, it shares 5 flexible feed support unit bodies 2 and forms.
As shown in Fig. 2, being equipped with hollow end cap 6 by bolt on two axial end faces of pedestal 7, it is used for pedestal 7 It closes inner cavity.Connecting flange 5 is mounted with by bolt and nut on hollow end cap 6, the diameter of bore of connecting flange 5 is 30mm, The outside of connecting flange 5 is cased with protection pipe 3 by welding or holding screw, and elastic feeding support unit body 2 is made to close, eliminate because The security risk that 1 high-speed motion of copper rod is brought.
As shown in figure 3, be mounted on supporting mechanism is fed in the installation stepped hole of pedestal 7 by butterfly spring group 11, 11 internal diameter 22.4mm of butterfly spring group, outer diameter 45mm are separately mounted to the interior outside of mounting hole using pairing combination, support 2 locking nuts 10 are installed in the outer end of bearing block 9, to precompressed butterfly spring group 11.The stroke of butterfly spring group 11 be 1 ~ 1.5mm, load are 1 ~ 2t.The fit clearance of butterfly spring group 11 and supporting bearing base 9 is the fit clearance of 1.3mm and pedestal 7 1.5mm.All faces coordinated with butterfly spring group 11 need to be heat-treated to after HRC52 grinding and polishing again.
As shown in figure 4, support construction is made of bearing 8, bearing jackshaft 15, supporting bearing base 9, assembly method is: Bearing 8 and supporting bearing base 9 are heated to 120 ° or so, or bearing jackshaft 15 is soaked into liquid nitrogen, with the side of the cold hole heat of axis Formula elastic conjunction.Bearing 8 is the bearing of the included lubrication of totally enclosed type, can be deep groove ball bearing, roller bearing or multi-directional ball Bearing, the type of bearing select service life of actual production process middle (center) bearing to be reference.
As shown in Figure 5,6, pedestal 7 is annular integral vertical type pedestal, and the annular diameters of annular mounting base are 150mm, outside Ring diameter 250mm, axial width 120mm.Axially intermediate ends have the installation stepped hole 3 being arranged circumferentially, rank Diameter 25mm, the thickness 20mm of terraced hole medial small hole, diameter 50mm, the thickness 16mm of outside macropore.
The operation principle of the present invention:
The copper rod 1 sent out by straightener is passed through in protection pipe 3, is passed through connecting flange 5, is transmitted to elastic feeding support unit body 2 It is interior, after being supported by the bearing 8 of 3 120 ° of arrangements, finally it is fed and expects in skew rolling mill.Since copper rod 1 is under the action of oblique milling power The compound motion of the radial high speed rotation of work, axial straight-line feed, copper rod 1 has a strong effect bearing 8, and passes through bearing jackshaft 15 are transmitted in supporting bearing base 9.The pairing butterfly spring group 11 and 7 bullet of pedestal for passing through inside and outside arrangement due to supporting bearing base 9 Property connection, to realize the elastic connection of supporting bearing base 9 and pedestal 7, the Elastic Contact of final realization bearing 8 and copper rod 1, To complete elastic pan feeding support.
Although having been presented for several embodiments of the present invention herein, it will be appreciated by those of skill in the art that Without departing from the spirit of the invention, the embodiments herein can be changed.Above-described embodiment is only exemplary, no It should be using the embodiments herein as the restriction of interest field of the present invention.

Claims (9)

1. a kind of Integral elastic material guide device of oblique milling copper rod, which is characterized in that single including rack, the support of several flexible feeds First body, protection pipe;Several described flexible feed support unit bodies are sequentially arranged along the rack, and the flexible feed support is single First body includes charging supporting mechanism, pedestal;The pedestal is fixedly connected on rack;The charging supporting mechanism and the pedestal bullet Spring connects, and copper rod is contained in several flexible feed support unit bodies and the protection pipe is formed by confined space, Realize the Elastic Contact of copper rod and the Integral elastic material guide device of the oblique milling copper rod.
2. the Integral elastic material guide device of oblique milling copper rod as described in claim 1, which is characterized in that the pedestal is annular Integral vertical type pedestal is equipped with 3 installation stepped holes being arranged circumferentially, 3 chargings in the pedestal axial direction intermediate ends Supporting mechanism is circumferentially staggered 120 ° in the pedestal by the installation stepped hole and is evenly arranged.
3. the Integral elastic material guide device of oblique milling copper rod as claimed in claim 2, which is characterized in that the charging support machine Structure includes bearing, bearing jackshaft, supporting bearing base, and bearing is mounted on the inside of supporting bearing base;The charging supporting mechanism Assembly method is:Bearing and supporting bearing base are heated to 100 ° -130 °, or bearing jackshaft 15 is soaked into liquid nitrogen, uses axis The mode elastic conjunction of cold hole heat.
4. the Integral elastic material guide device of oblique milling copper rod as claimed in claim 3, which is characterized in that the bearing is full envelope The bearing of the included lubrication of enclosed, is any one of deep groove ball bearing, roller bearing or universal ball bearing.
5. the Integral elastic material guide device of oblique milling copper rod as claimed in claim 2, which is characterized in that two of the pedestal Hollow end cap is equipped with by bolt on axial end face, for closing the inner cavity of the pedestal;It is covered in the hollow end logical Bolt and nut installation connecting flange is crossed, the outside of the connecting flange is cased with the protection pipe by welding or holding screw, makes The flexible feed support unit body closing.
6. the Integral elastic material guide device of oblique milling copper rod as claimed in claim 5, which is characterized in that the charging support machine Structure is installed on by butterfly spring group in the installation stepped hole of the pedestal, and the butterfly spring group is using pairing combination point Not An Zhuan the installation stepped hole medial and lateral, 2 locking nuts are installed in the outer end of the supporting bearing base, to precompressed Butterfly spring group.
7. the Integral elastic material guide device of oblique milling copper rod as claimed in claim 6, which is characterized in that the inner ring of the pedestal A diameter of 150mm, outer annular diameter 250mm, axial width 120mm;The stroke of butterfly spring group be 1 ~ 1.5mm, load be 1 ~ 2t;
The fit clearance of butterfly spring group and supporting bearing base is 1.3mm, the fit clearance 1.5mm with pedestal.
8. the Integral elastic material guide device of oblique milling copper rod as described in claim 1, which is characterized in that the flexible feed branch It is 5 to support cell cube, and the spacing of each flexible feed support unit body is 500 ~ 800mm, by bolt by the base Seat is fixed in the rack.
9. such as the Integral elastic material guide device of claim 1-8 any one of them oblique milling copper rods, which is characterized in that the machine Frame is installed on the ground by foundation bolt, and the height of rack is highly consistent with skew rolling mill feeding mouth.
CN201810286331.4A 2018-03-27 2018-03-27 A kind of Integral elastic material guide device of oblique milling copper rod Pending CN108372206A (en)

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CN201810286331.4A CN108372206A (en) 2018-03-27 2018-03-27 A kind of Integral elastic material guide device of oblique milling copper rod

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Application Number Priority Date Filing Date Title
CN201810286331.4A CN108372206A (en) 2018-03-27 2018-03-27 A kind of Integral elastic material guide device of oblique milling copper rod

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112692054A (en) * 2020-11-18 2021-04-23 江苏省镔鑫钢铁集团有限公司 Bar steel rolling and splitting process capable of reducing raw material cost
CN113899330A (en) * 2021-08-19 2022-01-07 北京科技大学 Full-automatic measurement system for spiral rib lead of cladding pipe

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5331835A (en) * 1992-04-15 1994-07-26 Innse Innocenti Engineering, S.P.A. Rolling stand, having three or more driven and adjustable rollers
TW390230U (en) * 1998-05-21 2000-05-11 Metal Ind Res & Dev Ct Automatic materials feeding adjustment mechanism applicable for rolling
RU2165816C2 (en) * 1999-03-17 2001-04-27 Открытое акционерное общество "Электростальский завод тяжелого машиностроения" Working stand of mill for helical rolling of bodies of revolution
CN101804421A (en) * 2010-03-23 2010-08-18 北京科技大学 Low-noise copper ball skew rolling feed device with straightening function
CN102039360A (en) * 2010-11-11 2011-05-04 北京科技大学 Safe, airtight and low-noise feeding equipment of copper balls during skew rolling
WO2012155854A1 (en) * 2011-05-18 2012-11-22 合肥市百胜科技发展股份有限公司 Rolling mill
CN202729397U (en) * 2012-06-08 2013-02-13 滁州精益模具设备制造有限公司 Rolling type lateral positioning device of plate material
CN202861000U (en) * 2012-06-08 2013-04-10 滁州精益模具设备制造有限公司 Auxiliary pressure positioning device on rear side surface of panel veneer on refrigerator side plate rolling mill
CN103316917A (en) * 2013-06-18 2013-09-25 太原科技大学 Three-roller skew continuous rolling mill for producing tubes or bars
CN204657364U (en) * 2015-06-08 2015-09-23 成都市新筑路桥机械股份有限公司 A kind ofly push away the equipment rolling shaping rail
CN205949494U (en) * 2016-08-18 2017-02-15 广东科莱博科技有限公司 A loading attachment for rolling mill
CN107511433A (en) * 2017-09-04 2017-12-26 扬州天开机电有限公司 A kind of automatic charging device of bending machine
CN208810821U (en) * 2018-03-27 2019-05-03 北京科技大学 A kind of Integral elastic material guide device of oblique milling copper rod

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5331835A (en) * 1992-04-15 1994-07-26 Innse Innocenti Engineering, S.P.A. Rolling stand, having three or more driven and adjustable rollers
TW390230U (en) * 1998-05-21 2000-05-11 Metal Ind Res & Dev Ct Automatic materials feeding adjustment mechanism applicable for rolling
RU2165816C2 (en) * 1999-03-17 2001-04-27 Открытое акционерное общество "Электростальский завод тяжелого машиностроения" Working stand of mill for helical rolling of bodies of revolution
CN101804421A (en) * 2010-03-23 2010-08-18 北京科技大学 Low-noise copper ball skew rolling feed device with straightening function
CN102039360A (en) * 2010-11-11 2011-05-04 北京科技大学 Safe, airtight and low-noise feeding equipment of copper balls during skew rolling
WO2012155854A1 (en) * 2011-05-18 2012-11-22 合肥市百胜科技发展股份有限公司 Rolling mill
CN202729397U (en) * 2012-06-08 2013-02-13 滁州精益模具设备制造有限公司 Rolling type lateral positioning device of plate material
CN202861000U (en) * 2012-06-08 2013-04-10 滁州精益模具设备制造有限公司 Auxiliary pressure positioning device on rear side surface of panel veneer on refrigerator side plate rolling mill
CN103316917A (en) * 2013-06-18 2013-09-25 太原科技大学 Three-roller skew continuous rolling mill for producing tubes or bars
CN204657364U (en) * 2015-06-08 2015-09-23 成都市新筑路桥机械股份有限公司 A kind ofly push away the equipment rolling shaping rail
CN205949494U (en) * 2016-08-18 2017-02-15 广东科莱博科技有限公司 A loading attachment for rolling mill
CN107511433A (en) * 2017-09-04 2017-12-26 扬州天开机电有限公司 A kind of automatic charging device of bending machine
CN208810821U (en) * 2018-03-27 2019-05-03 北京科技大学 A kind of Integral elastic material guide device of oblique milling copper rod

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
长沙机务段: "ND2型 内燃机车", vol. 1, 30 April 1975, 长沙机务段, pages: 114 - 115 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112692054A (en) * 2020-11-18 2021-04-23 江苏省镔鑫钢铁集团有限公司 Bar steel rolling and splitting process capable of reducing raw material cost
CN112692054B (en) * 2020-11-18 2022-03-04 江苏省镔鑫钢铁集团有限公司 Bar steel rolling and splitting process capable of reducing raw material cost
CN113899330A (en) * 2021-08-19 2022-01-07 北京科技大学 Full-automatic measurement system for spiral rib lead of cladding pipe
CN113899330B (en) * 2021-08-19 2022-11-04 北京科技大学 Full-automatic measuring system for spiral rib lead of cladding pipe

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