CN103192022A - Cold heading manufacturing method for tor-shear type bolt - Google Patents

Abstract

The invention relates to a cold heading manufacturing method for a tor-shear type bolt, which comprises the following steps: martial cutting; adopting a ternary-necking mould produced by hexin standard mould piece factory in Nibo; forcibly necking the cut material to the size of the diameter of a wabbler formed blank through the ternary-necking mould in the first procedure, wherein the enter angle is controlled within 25-27 degrees; performing pre-heading of head parts, telescopic rods, end surface pre- chamfer angles in the second procedure; finely performing heading of the bolt head parts and the chamfer angles in the third procedure; and necking the dodecagonal wabbler in the fourth procedure. The method has the benefits that the product consistency is good, the production efficiency is high, no consequent auxiliary expense is produced, and the procedures of parkerizing, necking the dodecagonal wabbler and the like are avoided, and accordingly the manpower and material resources are reduced, the processing cost is saved, and the market competitiveness is enhanced.

Description

Torque-shear type bolt cold-heading manufacture method

Technical field

The present invention relates to a kind of torque-shear type bolt, relate in particular to the manufacture method of this torque-shear type bolt.

Background technology

Along with the fast development of domestic economy in recent years, domestic power plant, skyscraper, railway, bridge are all keeping good development circumstances.GB3632-2008 torque-shear type bolt is domestic a kind of bolt for steel structure auxiliary connection commonly used, and it is easy for installation, and fastener shaft power also is easy to control.

As seen from Figure 1: torque-shear type bolt head semicircular in shape 1, afterbody have a bihexagonal wabbler 2, by the diameter of control groove 3, after bolt reaches certain fastener shaft power, can twist into two parts voluntarily and come off.Because 12 jiaos of wabblers become parison footpath deformation ratio bigger, area dwindles about 16% approximately, by the manufacture craft of prior art direct 12 jiaos of wabblers of cold-heading at all, needs be lubricated again after cold-heading, i.e. just can carry out follow-up processing and forming after the phosphatization processing.

As seen from Figure 2: earlier according to the bolt specification fracture, through the order mould bolt head of upsetting in advance, be conical.Two orders are heading portion just, and contracting bar portion size for prolonging the service life of bolt head cold-heading mould, should divide equally its stressing conditions to rolling tooth base footpath as far as possible, and generally the head moulding divides 2～3 times.The smart heading of three orders portion marks, and base footpath before the 12 jiaos of wabbler moulding of contracting, thus the time through contracting bar once, the surface lubrication layer is existing to be destroyed, and damages so mould is easy to plucking, this also is the improved place of this arts demand.Four orders need be carried out the phosphatization lubricated before the contracting wabbler, avoid that quality problems such as seal appear drawing in the surface when the contracting wabbler, and die life is also increased.The 12 jiaos of wabblers that contract are processed at punch press, need to adjust the stroke of punch press, between mould and upper trimming die to the heart, just can process after the adjustment.

Above-mentioned processing method makes that homogeneity of product is not fine, and is bigger to follow-up processing influence, production efficiency many weak points such as also lower, the process-cycle is long.

Summary of the invention

The technical issues that need to address of the present invention have provided a kind of torque-shear type bolt cold-heading manufacture method, are intended to solve the above problems.

In order to solve the problems of the technologies described above, the present invention realizes by following steps:

Fracture;

Adopt three contracting moulds of Ningbo and prosperous standard products mold factory, an order is reduced to wabbler by force by three contracting moulds and becomes parison footpath size; Going into the angle should control at 25 °-27 °;

The pre-heading of two orders portion, contracting bar, the pre-chamfering of end face;

The smart rammer bolt head of three orders and chamfering;

Four orders, the 12 jiaos of wabblers that contract.

Compared with prior art, the invention has the beneficial effects as follows: product one is good to property, the production efficiency height, and can not increase any so and the auxiliary expenses that produces, phosphatization, the 12 jiaos of several leading road of plum blossom manufacturing procedures of contracting have been lacked on the contrary, human and material resources have also reduced thereupon, have saved processing cost, have strengthened the market competitiveness.

Description of drawings

Fig. 1 is torque-shear type bolt arrangement schematic diagram.

Fig. 2 is the torque-shear type bolt manufacturing method flow chart of prior art.

Fig. 3 is flow chart of the present invention.

The specific embodiment

Below in conjunction with accompanying drawing and the specific embodiment the present invention is described in further detail:

As seen from Figure 3: the present invention realizes by following steps:

Fracture;

Adopt three contracting moulds of Ningbo and prosperous standard products mold factory, an order is reduced to wabbler by force by three contracting moulds and becomes parison footpath size; Going into the angle should control at 25 °-27 °;

The pre-heading of two orders portion, contracting bar, the pre-chamfering of end face;

The smart rammer bolt head of three orders and chamfering;

Four orders, the 12 jiaos of wabblers that contract.

Strong contracting is to wish that wabbler becomes parison once contracting bar moulding of footpath among the present invention, because the raw material surface had one deck phosphating coat, lubricate originally, through the cross once the contracting bar after, the surface lubrication film will destroy to some extent, as contracting bar repeatedly, contracting bar place is easy to occur drawing trace, should avoid as far as possible.The strong contracting of three contracting moulds requires also than higher raw-material hardness, and general material hardness should be controlled between HRB86-90, and the too high life-span for grinding tool of hardness can have a greatly reduced quality.Two orders mainly are pre-heading portion, contracting bar (tooth base footpath is rolled in contracting), the pre-chamfering of end face.Three orders mainly are smart rammer bolt head and chamfering, and the chamfering mould has the 0.5mm arc transition, the burr that produces in the time of can reducing the bolt chamfering between end face and the chamfering when making.Four orders mainly are 12 jiaos of wabblers of contracting, and 12 angle mould tool materials are selected YG20C wolfram steel for use, go into the angle and should control about 30 °, the excessive too small meeting of angle cause cut edge or the transition size long partially.

Claims (1)

1. torque-shear type bolt cold-heading manufacture method, realize by following steps:

Fracture;

Adopt three contracting moulds of Ningbo and prosperous standard products mold factory, an order is reduced to wabbler by force by three contracting moulds and becomes parison footpath size; Going into the angle should control at 25 °-27 °;

The pre-heading of two orders portion, contracting bar, the pre-chamfering of end face;

The smart rammer bolt head of three orders and chamfering;

Four orders, the 12 jiaos of wabblers that contract.

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