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Copper Tube Information

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brass tube bead nut

author:MF manufacturerstime:2022-03-15 11:39:31

Design of injection molded copper nut

(brass tube bead nut)


brass tube bead nut


(1) Features of the insert

1) Inserts are made of metal,It can increase the strength and stiffness of the whole or a part of the plastic part,as in the handle、Metal Bone Rod Inserts for Box Climbing,see picture。


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2) Shell to improve bond strength Plastic has very low strength,To connect two plastic parts together,If connected with screws,its strength is affected,Instead, a threaded insert is placed in the plastic part beforehand.,Can greatly improve the connection strength,and durable,see picture。

3) Plastic is a good insulator,And put some metal pieces in the plastic part、String、board etc.,make the electronic、electrical appliances、Useful for power components,Medium as shown。

4) The hardness of plastic is low,Poor resistance to external forces,Place suitable metal inserts where increased hardness and wear resistance are required,Will effectively improve the hardness and wear resistance of the insert。

(2) insert material

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(3) Design points for inserts

1) Metal inserts embedded in plastic parts cannot be sharp corners,should be properly rounded,In order to reduce the influence of stress concentration on plastic parts when the plastic around the insert cools,Improve the strength of plastic parts

2) If the insert is provided with a raised part on the plastic part,Its embedded depth should be greater than the height of the raised part,To ensure the mechanical strength of the embedded plastic parts,see picture

3) The distance between the insert and the side wall of the plastic part shall generally not be less than0.6mmIf there are inserts on the opposite side of the plastic part, The thickness of the plastic layer between the two inserts shall not be less than3. 5mmo

4) for inside、External thread insert,Its height should be slightly lower than the molding height of the cavity0.05mm about,To avoid crushing the insert and cavity,see picture。


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1) The plastic layer between the bottom surface of the insert and the bottom surface of the plastic part should have a certain thickness,Generally not less than the outer diameter of the insert1/6,If the thickness is too small,Plastic parts are prone to defects such as dents and cracks at this position。


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2) External thread insert,A section without thread should be set,To prevent molten material from penetrating into the mold,see picture。

(4) Fixing of inserts

1) In order to make the insert and the plastic part tightly combined,The insert surface should be knurled or grooved,to increase friction。Make the insert not easy to be pulled out during use,do not rotate etc.。

2) To facilitate placement and positioning of the insert in the mold,The part where the insert is placed in the mold should be designed to be cylindrical,In this way, it is convenient to place the insert in the relevant positioning round hole on the mold。

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brass tube bead nut


4) The height of the insert should be less than its diameter2times,The fit of the fixed part in the mold should be a tighter clearance fit。

5) if the board、Chip inserts,Can be fixed with hole and window fixing method,piece,It should be fixed by incision or bending,see picture。


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6) When setting inserts in bosses,In order to ensure the stability of the insert,and the strength of the plastic matrix,The insert should extend into the bottom of the boss,But the minimum bottom thickness must be guaranteed,Insert head to be rounded,see picture。


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7) For rod inserts,need to deform its head,flattened head、flush、Bending,Splits etc.,This deformed insert can be well combined and fixed with the plastic part,see picture。

8) Rod inserts embedded in the handle,The embedded part should be processed into a square shape,to prevent rotation,see picture。

9) Shaft inserts are generally inserted into the corresponding holes of the mold and fixed.,In order to prevent the molten material from being squeezed into the thread groove,Several methods can be used as shown in the figure。

①Polished rod,as shown。It utilizes the polished rod portion of the insert and the die fit。

②Shoulder fit,as shown。a shoulder,It not only increases the stability of the insert after inserting people,It can also prevent the molten material from flowing into the thread。

③ring fit,as shown。it has a protruding ring,During molding, the ring is pressed against the mold to form a sealing ring,Prevents molten material from flowing into the threads。

Shoulder fit,as shown。This is another form of shoulder fit,However, the difference between the outer diameter of the knurled part and the outer diameter of the threaded part is much larger。

10) If there are threaded inserts with no through holes in the hole type inserts,can be placed as shown in the figure


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①Blind hole positioning,as shown。Available with an optical axis inserted into the mold,Position it in the blind hole of the insert。

②Boss positioning as shown in the figure。Set a boss on the insert,Corresponding holes on the die。

③Concave positioning,as shown。Concave the insert,This concave is positioned with the corresponding shaft on the mold。

11) For elongated inserts,If its axis is perpendicular to the material flow direction,easy to bend,As shown。to this end,Some supports can be installed where the slender insert is deformed,to increase its rigidity,as the picture shows,But beware,Additional support holes should not affect the use of plastic parts。


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5、Screw column design

5.1 The two shells are usually fixed by means of screws and snaps,The screw post usually also acts on thePCBplate positioning。

5.2 The design principle of the screw column for self-tapping screws is to:Its outer diameter should beScrewoutside diameter2.0~2.4times。picture6-2forM1.6×0.35Dimensional relationship of self-screw and stud。available in design:Outer diameter of screw=2×Screw outer diameter;Stud ID(ABS,ABS+PC)=Screw outer diameter-0.40mm;Stud ID(PC)=Screw outer diameter-0.30mmor-0.35mm(You can press0.30mmto design,After the test is passed, the mold will be repaired and glued);The distance between the stud surfaces of the two shells is taken as0.05mm。

5.3 different materials、The design values of screw holes for different screws are shown in the table5-2、surface5-3shown。

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