阅读说明：本技术 不锈钢卡压管件成形工艺 (Stainless steel clamping and pressing pipe fitting forming process ) 是由 徐晓东 赵洪强 周淑云 陆仁兴 王新伟 张立峰 张忠明 陆博凡 沈科 计龙余 于 2019-11-07 设计创作，主要内容包括：一种不锈钢卡压管件制备工艺,包括成形阶段和整形阶段,所述成形阶段采用液压胀形工艺,其中,所述液压胀形工艺采用上下模具和左、右推头将管坯固定在成形腔内,经由左、右推头内部的输油管路输入高压油,使管坯在液压油的液体压力下产生径向扩张；所述整形阶段采用滚压工艺,采用凸辊和凹槽辊一边在管坯的管轴方向上赋予压力一边进行滚压加工。本发明在成形阶段采用高效的液压胀形工艺,在整形阶段采用滚压工艺,在确保成形精度的同时,有效降低了设备成本,液压胀形设备压力不超过30MPa。(A preparation process of a stainless steel clamping and pressing pipe fitting comprises a forming stage and a shaping stage, wherein a hydraulic bulging process is adopted in the forming stage, an upper die, a lower die, a left push head and a right push head are adopted in the hydraulic bulging process to fix a pipe blank in a forming cavity, and high-pressure oil is input through oil conveying pipelines inside the left push head and the right push head to enable the pipe blank to radially expand under the hydraulic pressure of the hydraulic oil; and in the shaping stage, a rolling process is adopted, and a convex roller and a groove roller are adopted to apply pressure in the pipe shaft direction of the pipe blank and perform rolling processing. The invention adopts the high-efficiency hydraulic bulging process in the forming stage and the rolling process in the shaping stage, thereby effectively reducing the equipment cost while ensuring the forming precision, and ensuring that the pressure of the hydraulic bulging equipment is not more than 30 MPa.)

1. A preparation process of a stainless steel clamping and pressing pipe fitting comprises a forming stage and a shaping stage, wherein the forming stage adopts a hydraulic bulging process, wherein,

the hydraulic bulging process adopts an upper die, a lower die, a left push head and a right push head to fix the tube blank in a forming cavity, and high-pressure oil is input through oil pipelines inside the left push head and the right push head to enable the tube blank to radially expand under the hydraulic pressure of the hydraulic oil;

in the shaping step, a rolling process is adopted, and a convex roller and a concave roller are adopted to roll while applying pressing force in the radial direction of the tube blank.

2. The manufacturing process according to claim 1, wherein the output pressure of the hydraulic press in the forming stage is set to 20-30MPa, and the displacement amount of the left and right horizontal push heads at both ends of the pipe fitting is 80-100 mm.

3. The process according to claim 1, wherein the tube blank is continuously formed by a plurality of sets of concave rollers and convex rollers by continuously passing the tube blank between a plurality of sets of press rollers by a continuous rotary rolling process, and a finished product is obtained after the rolling is finished.

4. The process according to claim 1, wherein the surface of the male roller is coated with a layer of liquid glue during rolling, and the glue on the surface of the male roller is used to coat a certain amount of glue inside the protrusions of the pipe clamp during rolling.

5. The manufacturing process according to claim 4, wherein the glue is applied to the surface of the convex roller of the end concave-convex pressing roller set.

Technical Field

The invention relates to a forming process of a stainless steel clamping and pressing pipe fitting.

Background

The stainless steel material has outstanding corrosion resistance and good mechanical property, can be made into a thin-wall pipe to reduce cost, so that the application of the thin-wall stainless steel pipeline system in various industries is popularized and used in many countries. Thin-walled stainless steel pipes are not suitable for general screw connection because of their small wall thickness (generally less than 1.5 mm). The stainless steel clamping-pressing type pipe fitting has the advantages of quick and simple installation, stable pressure resistance, corrosion resistance, no pollution to fluid medium and the like, and is an ideal connecting piece for thin-wall stainless steel pipelines. Stainless steel clamp-press type pipe fittings are widely used in developed countries such as sweden, germany and japan. China also released an industrial standard in 2001 to popularize the application of a thin-wall stainless steel pipeline system in an urban water supply system so as to ensure the water quality of supplied water, prolong the service life of the pipeline, improve the reliability of the water quality of supplied water and ensure the health of residents.

The thin-wall stainless steel clamping-pressing type pipe fitting is made up by using thin-wall stainless steel straight-seam welded pipe as blank material through the processes of cold plastic deformation, welding and surface treatment, etc. and mainly has the forms of straight-through, three-way and elbow. In the line forming process, forming equipment with large hydraulic pressure is needed, the equipment cost and the energy consumption are high, and the production cost is needed to be reduced when materials of stainless steel pipe fittings are popularized.

Disclosure of Invention

The invention provides a stainless steel clamping and pressing pipe fitting molding process, which reduces the pressure of hydraulic equipment, thereby reducing the cost and energy consumption.

The invention improves the high-energy-consumption forming stage based on the energy consumption research of each stage of the stainless steel clamping and pressing pipe fitting forming process, thereby not only reducing the energy consumption and the equipment cost, but also ensuring the performance of the product.

The preparation process of the stainless steel clamping and pressing pipe fitting comprises a forming stage and a shaping stage, wherein the forming stage adopts a hydraulic bulging process, wherein,

the hydraulic bulging process adopts an upper die, a lower die, a left push head and a right push head to fix the tube blank in a forming cavity, and high-pressure oil is input through oil pipelines inside the left push head and the right push head to enable the tube blank to radially expand under the hydraulic pressure of the hydraulic oil;

and in the shaping stage, a rolling process is adopted, and a convex roller and a concave roller are adopted to roll while applying pressure in the pipe shaft direction of the pipe blank.

Furthermore, the output pressure of the hydraulic machine in the forming stage is set to be 20-30MPa according to the wall thickness and the shape of the pipe fitting, and the displacement of the left horizontal pushing head and the right horizontal pushing head at the two ends of the pipe fitting is 80-100 mm.

Furthermore, a continuous rotary rolling process is adopted, the tube blank continuously passes through a plurality of groups of press rolls and is continuously formed by a plurality of groups of concave rolls and convex rolls, and a finished product is obtained after rolling is finished.

Further, a layer of liquid glue is brushed on the surface of the convex roller during rolling, and a certain amount of glue is coated inside the protrusions of the clamping and pressing pipe fitting during the rolling process by means of the glue on the surface of the convex roller.

Further, the glue is coated on the surface of the convex roller in the terminal concave-convex pressing roller group.

The invention adopts an efficient hydraulic bulging process in the forming stage to apply uniform bulging pressure to the tube blank, so that the tube blank has uniform and smooth wall thickness and good dimensional precision, and can be formed by adopting a low-tonnage hydraulic press.

In addition, the invention adopts a rolling process in the shaping stage, avoids shaping by using high-pressure hydraulic equipment, effectively reduces the pressure of the equipment, and ensures that the pressure of hydraulic bulging equipment does not exceed 30 MPa.

Drawings

FIG. 1 shows the equipment used in the process for preparing stainless steel clamping-pressing pipe fitting of the present invention.

Detailed Description

The process for forming the stainless steel pressure pipe fitting provided by the invention is further described with reference to the following specific examples.

The forming method of the stainless steel clamping and pressing pipe comprises the following steps: blanking, deburring, extrusion forming, annealing, pickling passivation and inspection.

The annealing is carried out in an ammonia decomposition crawler-type solid-state furnace, and the annealing is carried out at 1100 ℃ for 90min, so that the stress is eliminated and the elongation is not changed.

The preparation process of the stainless steel clamping and pressing pipe fitting comprises a forming stage and a shaping stage, wherein the forming stage adopts a hydraulic bulging process, wherein,

referring to fig. 1, in the hydraulic bulging process, an upper die 3 and a lower die 5, a left push head 1 and a right push head 4 are adopted to fix a tube blank in a forming cavity, high-pressure oil is input through oil pipelines inside the left push head and the right push head, so that the tube blank is radially expanded under the hydraulic pressure of the hydraulic oil, and the extrusion speed is 13 mm/s;

the upper die 3 is made of Cr12MoV and is subjected to heat treatment of 50-58HRC, the lower die 5 is machined by adopting H13 steel, and other structures are machined by adopting 45 steel and are subjected to heat treatment of 40-45 HRC.

And (3) forming: sleeving a rubber pipe into the pipe blank, keeping the outer diameter of the sealing rubber pipe consistent with the inner diameter of the pipe blank 2, placing the pipe blank 2 into a cavity of a lower die, and closing an upper die and the lower die to enable the pipe blank 2 to be in a closed die forming cavity;

the left push head 1 and the right push head 4 are respectively connected with two oil cylinders, and the oil cylinders perform feed motion to drive the two push heads to respectively move towards the middle part along the axial direction of the tube blank. The left push head and the right push head are in interference fit with the whole of the tube blank and the rubber tube, so that the connection and sealing between the push heads and the tube blank are realized, and the separation of the push heads and the tube blank is prevented;

the fluid medium enters the tube blank through the oil pipeline in the left push head 1, and internal pressure which is uniformly distributed is applied to the inner surface of the tube blank;

the tube blank moves along the circumferential direction under the fluid pressure to fill the cavity, and the section forming is realized. In the expansion process, the left push head and the right push head move towards the middle part along the central axis of the tube blank, so that the axial material supply amount is increased, and the circumferential material deformation is supplemented.

The output pressure of the hydraulic machine is set to be 20-30MPa according to the wall thickness and the shape of the pipe fitting, so that the local material gathering at the position with the characteristic of difficult deformation is ensured, the subsequent precision requirement of parts is ensured, and meanwhile, the excessive blank is prevented from flowing into a gap between a die and a pipe blank to cause the accumulation and wrinkling of materials.

The displacement of the left and right horizontal pushing heads at the two ends of the pipe fitting is 100 mm.

Shaping phase

Shaping by roll forming, using a convex roller with the outer diameter of 80-100mm, the width of 5-10mm and the curvature radius of 2.5mm and using a concave roller with the outer diameter of 90-110mm, the groove depth of 12-15mm, the inner wall width of the annular groove of 10mm and the curvature radius of 2.5mm, rolling while applying a pressing force in the radial direction of the pipe body, and finally forming a clamping convex strip with the height of about 5-6 mm.

The continuous rotary rolling process is adopted, the tube blank continuously passes through a plurality of groups of concave-convex press rolls and is continuously formed by a plurality of groups of concave rolls and convex rolls, and a finished product is obtained after rolling is finished. Because the forming is carried out gradually, the deformation force is reduced, the strength requirement on the die roller is reduced, the noise is reduced, and the service life of the compression roller is prolonged.

In addition, a layer of liquid glue is brushed on the surface of the convex roller during rolling, and a certain amount of glue is coated inside the bulge of the clamping and pressing pipe fitting during the rolling process by means of the glue on the surface of the convex roller, so that the subsequent installation of the O-shaped sealing ring is facilitated, and the assembly efficiency is improved.

And the glue is coated on the surface of the convex roller in the concave-convex pressing roller group at the tail end.

The invention adopts an efficient hydraulic bulging process in the forming stage to apply uniform bulging pressure to the tube blank, so that the tube blank has uniform and smooth wall thickness and good dimensional precision, and can be formed by adopting a low-tonnage hydraulic press.

The invention adopts a rolling process in the shaping stage, avoids shaping by using high-pressure hydraulic equipment, effectively reduces the pressure of the equipment, and ensures that the pressure of the hydraulic bulging equipment does not exceed 30 MPa.

While the best mode for carrying out the invention has been described in detail, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily produce alterations to, variations of, and equivalents to these embodiments. Therefore, any technical solutions that can be obtained by a person skilled in the art through logical analysis, deduction or based on limited experiments on the basis of the prior art according to the present inventive concept should be within the scope of protection defined by the present claims.