JP7106004B2 - Medium and small diameter thick-walled metal pipe and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to the field of metal tube material processing technology, and more particularly to medium and small-diameter thick-walled metal tubes and methods for manufacturing the same.

At present, the main methods of forming medium- and small-diameter thick-walled metal pipes (where D/S is within the range of 2 to 20) include extrusion and rolling. The product cost is high, the market is not competitive, and it is usually used to produce very few metal tubes that cannot or are difficult to produce by other processes. Hot roll forming mainly includes rotary forging mill, 3-roll cross roll forming, and stretch reduction forming.

A rotary forging mill feeds a pipe material into a rolling groove consisting of a mandrel and a caliber that periodically reciprocates at a constant frequency. , to achieve the functions of diameter reduction and wall thickness reduction. Two-stage pilger rolling mills are generally used as rotary forging mills, but in the rolling process, the frame and rolling rolls reciprocate, and there are many moving parts, and the inertia is large, so the rolling process is stable. In addition, the structure of the rolling mill is complicated, making maintenance and adjustment difficult. The pipe material rolled by the two-high rolling mill has low dimensional accuracy and poor surface quality.

The three rolls of the three-roll cross mill are evenly arranged to form an angle of 120° around the rolling centerline, and the axes of the rolls and the rolling centerline are inclined and intersect at a specific angle (i.e. , rolling angle and feed angle), so that the billet advances spirally due to the action of the rolling rolls, forming a "helical line" on the outer surface of the rolled tube material, affecting the surface quality and stopping the rolling It is prone to "triangle" defects in the rear that cause .

A 3-roll stretch reduction mill is generally a series of grooves composed of 10 or more frames, which provides stretching through the difference in rotation speed of the mill rolls of adjacent frames, thereby hollow reducing the billet. However, due to the large number of frames, the equipment investment is large, the production line is long, the site area is large, and the equipment adjustment and control are complicated.

SUMMARY OF THE INVENTION The present invention provides a medium-sized and small-diameter thick-walled metal pipe and a manufacturing method thereof to solve the problems in the prior art. The present invention has the characteristics of both forging and rolling, realizes single-pass processing of metal billets, large deformation amount, short process, high product dimensional accuracy (±0.2mm), inner and outer wall surface quality good and low cost.

SUMMARY OF THE INVENTION A first object of the present invention is to provide a medium to small diameter thick-walled metal pipe.

The range of the cross-sectional diameter of the metal tube is 30-160 mm, the dimensional accuracy is ±0.2 mm, and the ratio of the metal tube outer diameter to the wall thickness is greater than 2 and 20 or less.

Preferably,
The cross-sectional diameter of the metal tube ranges from 30 to 100 mm,
The ratio of the outer diameter of the metal tube to the wall thickness is greater than 2 and no greater than 12, more preferably greater than 2 and no greater than 10, and most preferably greater than 2 and no greater than 5.

The inner and outer walls of the metal tube have no peeling, dent marks or cracks.

The material of the metal tube is preferably steel, copper, aluminum, magnesium, titanium, or an alloy.

A second object of the present invention is to provide a method for manufacturing medium- and small-diameter thick-walled metal pipes.

(1) selecting a billet and cutting it to a standard length;
(2) attaching the billet to the material supply frame, clamping the rear end of the billet with a clamping device and supporting the leading end with a support roll to ensure that the core casting device passes through the inner bore of the billet;
(3) Before each pass, the material feeding mechanism feeds the billet by 5 to 30 mm at a feeding speed of 1 to 3 m / min so that it enters the composite forging device and is formed. ,
(4) rotating the billet about its central axis by 15 to 90° each time the billet is formed once in the composite forging machine;
(5) repeating process steps (3) and (4) until the leading edge of the billet enters the material receiving frame, the material receiving mechanism clamping the leading edge of the billet and the material feeding frame releasing the trailing edge of the billet; the billet continues to advance in conjunction with the material receiving mechanism until molding of the entire billet is completed;
(6) cooling and cutting to length;

where preferably
In step (1), the billet has an outer diameter of 40-180 mm and a standard length of 0.5-10 m;
In step (3), in the case of cold forming, the billet is fed directly into the composite forging device, and in the case of hot forming, the billet is heated to the target temperature by the induction heating device, and then the billet is heated to the target temperature. send to
In step (3), when hot forming, the induction heating device is preferably a medium-wave induction heating coil, and the target temperature range is preferably 800-1200°C.

Said compound forging machine consists of three oscillating mold blocks, equidistantly arranged at 120° around the central axis of the billet, the mold blocks having a crank connecting rod mechanism driven by a motor. The mold block performs reciprocating linear motion with the connecting shaft while rotating around the connecting shaft, and spur gears are connected to both ends of the connecting shaft through flat keys. Mounted, the movement displacement and rotation angle of the mold are controlled by spur gears.

Specifically, the present invention can employ the following technical solutions.

The process is as follows. (1) Select an appropriate billet and cut it to length. (2) The billet is mounted on the material feeding frame, the trailing end of the billet is clamped by the clamping device, and the leading end is supported by the supporting rolls to ensure that the core casting device passes through the inner bore of the billet. (3) Every time one pass is started, before that, the billet is fed by 5 to 30 mm at a feed speed of 1 to 3 m / min for the material feed mechanism, and when cold forming, after feeding, directly to the composite forging forming device In the case of feeding and hot forming, the billet is heated to the target temperature by an induction heating device and then fed into a composite forging forming device. (4) Each time the billet is formed once in the composite forging device, the billet is rotated 15 to 90° around its central axis, fed again by 5 to 30 mm, and then returned to the composite forging device. Put in and shape. (5) repeating process steps (3) and (4) until the leading edge of the billet enters the material receiving frame, the material receiving mechanism clamping the leading edge of the billet and the material feeding frame releasing the trailing edge of the billet; The billet continues to advance in conjunction with the material receiving mechanism until the entire billet has been molded. (6) Cool and cut to length.

The process is mainly
(1) selecting a suitable billet and cutting it to size;
(2) attaching the billet to the material supply frame, clamping the rear end of the billet with a clamping device and supporting the leading end with a support roll to ensure that the core casting device passes through the inner bore of the billet;
(3) Every time one pass is started, before that, the billet is fed by 5 to 30 mm at a feed speed of 1 to 3 m / min for the material feed mechanism, and when cold forming, after feeding, directly to the composite forging forming device In the case of feeding and hot forming, a step of heating the billet to a target temperature with an induction heating device and then feeding it into a composite forging device;
(4) Each time the billet is formed once in the composite forging device, the billet is rotated 15 to 90° around its central axis, fed again by 5 to 30 mm, and then returned to the composite forging device. placing and molding;
(5) repeating process steps (3) and (4) until the leading edge of the billet enters the material receiving frame, the material receiving mechanism clamping the leading edge of the billet and the material feeding frame releasing the trailing edge of the billet; the billet continues to advance in conjunction with the material receiving mechanism until molding of the entire billet is completed;
(6) cooling and cutting to length;

The billet selected in the present invention includes high-frequency straight seam welded pipes and seamless pipes, and the material requirements include steel pipes and non-ferrous metal pipes such as aluminum, copper, magnesium, and titanium, and the billet outer diameter is 40-180 mm. , the standard length is 0.5~10m.

In the present invention, the forming mold is composed of three oscillating mold blocks, which are equally spaced at 120° around the center axis of the billet, and the mold blocks are equipped with a crank connecting rod mechanism driven by a motor. The mold block oscillates synchronously through the connecting shaft, and while rotating around the connecting shaft, performs reciprocating linear motion with the connecting shaft, and its movement displacement and rotation angle exactly correspond to each other.

In the present invention, the feeding speed of the billet is 1-3 m/min, and the amount of each feed is 5-30 mm.

In the present invention, the process can be carried out in cold and hot forming methods, the induction heating device in step (3) is a medium-wave induction heating coil, and the forming temperature range is 800~ 1200°C.

The present invention is applicable to the forming of medium and small diameter metal pipes of various metal materials, the outer diameter range of the product is 30 to 160 mm, and the ratio of the outer diameter to the wall thickness (D/S) is greater than 2. 20 or less.

In the present invention, the dimensional accuracy of the obtained metal tube product is ±0.2 mm.

The beneficial effects of the above technical solution of the present invention are as follows.

(1) It is possible to realize a single-pass processing of a metal billet in which the cross section changes with a large amount of deformation.

(2) The process is short and the equipment investment is small.

(3) The dimensional accuracy of the product is high (±0.2 mm), and the quality of the inner and outer walls is good.

(4) The process has the characteristics of forging and rolling, and the deformation mass point is in the triaxial compressive stress state, which can be applied to cold and hot forming of small and medium diameter metal pipes of various metal materials.

1 is a schematic diagram of a composite forged metal tube forming machine of the present invention; FIG. 1 is a schematic diagram of a transmission device of the present invention; FIG. 1 is a schematic diagram of a composite forging forming apparatus of the present invention; FIG. FIG. 4 is a side sectional view of FIG. 3; 1 is a schematic diagram of an induction heating coil of the present invention; FIG. 1 is a schematic diagram of a core casting apparatus of the present invention; FIG. It is a schematic diagram of the material supply apparatus of this invention. 1 is a schematic diagram of a material receiving device of the present invention; FIG. 1 is a schematic diagram of a small-diameter thick-walled metal tube product of the present invention; FIG. FIG. 10 is a schematic diagram of the cross section of FIG. 9;

The present invention will be further described below with reference to examples.

With the steel pipe 6 as a billet, the billet is attached to the material supply frame 8, the rear end of the billet is clamped by the hydraulic chuck 27, and the core casting device 7 is ensured to pass through the inner bore of the billet, and the length is 1.5 m. The billet is fed by 25 mm at a feeding speed of /min, and after the billet enters the induction heating coil 4 and is heated to 1000° C., it enters the forming frame 3 . Each time the billet is formed once, the billet is rotated 60° around its central axis and fed again by 25 mm in the compound forging device until the tip of the billet enters the material receiving frame 1. . The material receiving mechanism clamps the leading end of the billet, the material supply frame releases the trailing end of the billet, and the billet continues to advance in conjunction with the material receiving mechanism until the entire billet is formed. After the billet is cooled, it is cut into regular lengths.

Example 1
(1) Q235 high-frequency straight-seam welded pipe is selected as the billet, the original outer diameter of the billet is 86mm, the wall thickness is 4.5mm, and the standard length is 3m.

(2) The billet is mounted on the material supply frame, the leading end is supported by the supporting roll, the trailing end of the billet is clamped by the clamping device, the core casting device is ensured to pass through the inner bore of the billet, and the mandrel is straight. The diameter of the part is 54 mm.

(3) Before starting each pass, the material supply mechanism feeds the billet by 25 mm at a supply speed of 1.5 m / min, heats the billet to 1000 ° C. with an induction heating coil, and then feeds it to the composite forging device. Send in.

(4) Each time the billet is formed once in the composite forging device, the billet is rotated 60° around its center axis, fed again by 25 mm, heated by the induction coil, and then heated by the induction coil. Put it in and mold it.

(5) repeating process steps (3) and (4) until the leading edge of the billet enters the material receiving frame, the material receiving mechanism clamping the leading edge of the billet and the material feeding frame releasing the trailing edge of the billet; The billet continues to advance in conjunction with the material receiving mechanism until the entire billet has been molded.

(6) Cool and cut to length.

The billet obtained by this molding process has an outer diameter of 65 mm, a wall thickness of 5.5 mm, a product dimensional accuracy of ±0.2 mm, and no defects such as peeling or dent marks on the inner and outer walls.

Example 2
(1) 08Al seamless steel pipe is selected as the billet, the original outer diameter of the billet is 60mm, the wall thickness is 3.8mm, and the standard length is 5m.

(2) The billet is mounted on the material supply frame, the leading end is supported by the supporting roll, the trailing end of the billet is clamped by the clamping device, the core casting device is ensured to pass through the inner bore of the billet, and the mandrel is straight. The diameter of the part is 25 mm.

(3) Before each pass, the material supply mechanism feeds the billet by 20 mm at a feed speed of 2 m/min, heats the billet to 900° C. with an induction heating coil, and then feeds it into the composite forging machine.

(4) Each time the billet is formed once in the composite forging device, the billet is rotated 75° around its center axis, fed again by 20 mm, heated by the induction coil, and then the composite forging device Put it in and mold it.

(5) repeating process steps (3) and (4) until the leading edge of the billet enters the material receiving frame, the material receiving mechanism clamping the leading edge of the billet and the material feeding frame releasing the trailing edge of the billet; The billet continues to advance in conjunction with the material receiving mechanism until the entire billet has been molded.

(6) Cool and cut to length.

The billet obtained by this molding process has an outer diameter of 35 mm, a wall thickness of 5 mm, a product dimensional accuracy of ±0.18 mm, and no defects such as peeling of inner and outer walls and dent marks.

Example 3
(1) A copper tube is selected as the billet, the billet's original outer diameter is 60mm, wall thickness is 4mm, and the standard length is 6m.

(2) The billet is mounted on the material supply frame, the leading end is supported by the supporting roll, the trailing end of the billet is clamped by the clamping device, the core casting device is ensured to pass through the inner bore of the billet, and the mandrel is straight. The diameter of the part is 18 mm.

(3) Every time one pass is started, before that, the material feeding mechanism feeds the billet by 10 mm at a feeding speed of 3 m/min and feeds it into the compound forging device.

(4) Each time the billet is formed once in the composite forging device, the billet is rotated 45° around its central axis, fed again by 10 mm, and then put into the composite forging device again to be formed. .

(5) repeating process steps (3) and (4) until the leading edge of the billet enters the material receiving frame, the material receiving mechanism clamping the leading edge of the billet and the material feeding frame releasing the trailing edge of the billet; The billet continues to advance in conjunction with the material receiving mechanism until the entire billet has been molded.

(6) Cut to a fixed length.

The outer diameter of the aluminum tube product obtained using the cold forming process is 30 mm, the wall thickness is 6.5 mm, the inner and outer walls are smooth, there are no defects such as peeling and dent marks, and the dimensional accuracy of the product is ± 0.2 mm.

Example 4
(1) A pure aluminum tube is selected as the billet, the billet's original outer diameter is 140mm, wall thickness is 10mm, and the standard length is 8m.

(2) The billet is mounted on the material supply frame, the leading end is supported by the supporting roll, the trailing end of the billet is clamped by the clamping device, the core casting device is ensured to pass through the inner bore of the billet, and the mandrel is straight. The part diameter is 85 mm.

(3) Every time one pass is started, before that, the material feeding mechanism feeds the billet 8 mm at a feeding speed of 3 m/min and feeds it into the compound forging device.

(4) Each time the billet is formed once in the composite forging device, the billet is rotated 25° around its center axis, fed again by 8 mm, and then put into the composite forging device again to be formed. .

(5) repeating process steps (3) and (4) until the leading edge of the billet enters the material receiving frame, the material receiving mechanism clamping the leading edge of the billet and the material feeding frame releasing the trailing edge of the billet; The billet continues to advance in conjunction with the material receiving mechanism until the entire billet has been molded.

(6) Cut to a fixed length.

The outer diameter of the aluminum pipe product obtained using the cold forming process is 110 mm, the wall thickness is 12.5 mm, the inner and outer walls are smooth, and there are no defects such as peeling or dent marks, and the product's dimensional accuracy is ± 0.2 mm.

The above are preferred embodiments of the present invention. It should be noted that for those skilled in the art, some improvements and modifications may also be made without departing from the above principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. .

DESCRIPTION OF SYMBOLS 1... Material receiving frame, 2... Transmission frame, 3... Forming frame, 4... Induction heating coil, 5... Control cabinet of induction heating device, 6... Billet, 7... Core mold, 8... Material supply frame, 9... Eccentricity Wheel connecting rod 10 Molded frame base 11 Main transmission shaft 12 Transmission bevel gear A meshing with each other 13 Transmission bevel gear B meshing with each other 14 Transmission bevel gear C meshing with each other 15 Transmission bevel gear meshing with each other D, 16... Intermediate transmission shaft, 17... Eccentric wheel shaft, 18... Eccentric wheel, 19... Connecting shaft, 20... Bearing seat connecting rod, 21... Fan-shaped mold block, 22... Mold shaft, 23... Stroke spur gear, 24... Rack, 25... Mold rail frame, 26... Material supply support roll, 27... Hydraulic chuck, 28... Servo motor, 29... Small reduction gear, 30... Large reduction gear, 31... Chuck sheet, 32... Travel carriage, 33... Travel carriage guide pulley, 34 positioning guide rail, 35 core mold positioning sheet, 36 material supply table, 37 support leg, 38 motor of traveling carriage, 39 material receiving support roll

Claims (4)

A method for manufacturing a thick-walled metal tube of medium and small diameter, wherein the ratio of the outer diameter of the metal tube to the wall thickness is greater than 2 and equal to or less than 20 ,
(1) selecting a billet and cutting it to a standard length;
(2) attaching the billet to the material supply frame, clamping the rear end of the billet with a clamping device and supporting the leading end with a support roll to ensure that the core casting device passes through the inner bore of the billet;
(3) Before each pass, the material feeding mechanism feeds the billet by 5 to 30 mm at a feeding speed of 1 to 3 m / min so that it enters the composite forging device and is formed. ,
(4) rotating the billet about its central axis by 15 to 90° each time the billet is formed once in the composite forging machine;
(5) repeating process steps (3) and (4) until the leading edge of the billet enters the material receiving frame, the material receiving mechanism clamping the leading edge of the billet and the material feeding frame releasing the trailing edge of the billet; the billet continues to advance in conjunction with the material receiving mechanism until molding of the entire billet is completed;
(6) cooling and cutting to length ;
Said composite forging machine consists of three oscillating mold blocks, equidistantly arranged at 120° around the central axis of the billet, the mold blocks having a crank connecting rod mechanism driven by a motor. The mold block performs reciprocating linear motion with the connecting shaft while rotating around the connecting shaft, and spur gears are connected to both ends of the connecting shaft through flat keys. A method for manufacturing medium- and small-diameter thick-walled metal pipes, characterized in that the movement displacement and rotation angle of the mold are controlled by spur gears . In step (1), the billet has an outer diameter of 40-180 mm and a standard length of 0.5-10 m.
2. The method for manufacturing a medium-sized and small-diameter thick-walled metal pipe according to claim 1 , wherein: In step (3), in the case of cold forming, the billet is fed directly into the composite forging device, and in the case of hot forming, the billet is heated to the target temperature by the induction heating device, and then composite forging. send to the device
2. The method for manufacturing a medium-sized and small-diameter thick-walled metal pipe according to claim 1 , wherein: In step (3), when hot forming, the induction heating device is a medium-wave induction heating coil, and the target temperature range is 800-1200 ℃;
2. The method for manufacturing a medium-sized and small-diameter thick-walled metal pipe according to claim 1 , wherein:

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