JP2002527241A - Apparatus and method for forming tube with increased wall thickness at end - Google Patents

Abstract

Apparatus for and method of extruding a metal pipe having a uniform inner diameter, and forward and rearward end sections (62, 66) which are thicker than the middle section (64) of the pipe. A metal billet (54) having a bore (56) is inserted into an open ended cylindrical bore of a stationary container (12). The billet (54) is moved axially within the bore of the container (12) by a press (13) which includes a pressing surface (38, 39) and a mandrel (44) extending forwardly from the pressing surface through the bore of toward the billet (54). The mandrel (44) has a cylindrical large diameter rearward portion (48), a cylindrical small diameter middle portion (50) and a forwardly and outwardly tapering forward portion (52). Metal from the billet (54) is forced through the small diameter bore of a two part removable first die (20) around the middle portion (50) of the mandrel (44) by moving the press forwardly for a first distance to form a preliminary forward end section (62) of pipe. The press is moved forwardly for a second distance for forcing metal from the billet through the bore of the first die (51) around the rearward portion (48) of the mandrel for extruding the middle section (64) of pipe and causing the preliminary forward end section (62) of pipe to pass over the tapered forward portion (52) of the mandrel to form the forward end section (62) of pipe. The press is moved forwardly for a third distance for forcing metal from the billet through the relatively large bore of a second die (53) around the rearward portion (48) of the mandrel to form the rearward end section (66) of pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD [0001] The present invention relates to the manufacture of pipes, especially in trade, "double ended upset pipes".
("upset pipe)". Such a tube has a front or "pin" end section, an extended middle section, and a rear or "box" end section. The inside diameter of all three sections of the tube is the same. The outside diameter of the front and rear end sections of the tube is substantially larger than the outside diameter of the middle section of the tube. As such, the thickness of the middle section of the tube is substantially less than any of the front and rear end sections of the tube.

BACKGROUND OF THE INVENTION The present invention is directed to an apparatus for forming a fluid transport tube known as a "double-ended upset tube" in a transaction. Such a tube has a front or "pin" end section, an extended middle section, and a rear or "box" end section. The inside diameter of all three sections of the tube is the same. The outside diameter of the front and rear end sections of the tube is substantially larger than the outside diameter of the middle section of the tube. As such, the thickness of the middle section of the tube is substantially less than any of the front and rear end sections of the tube. The extra thickness of the front and rear end sections of the tube is such that the front or "pin" end of the first tube can be joined to the rear or "box" end of the second tube by machining and And / or threaded.

Conventionally, double-ended upset pipes made of metal have been formed by separately extruding the middle and end sections of the pipe and welding the front and rear end sections to both ends of the middle section. Since the weld zone represents a potentially weak area of the tube, each section of the tube was made thicker than normally required. This procedure is time consuming and expensive. The extra thickness, which requires extra material, also adds material costs to the tube. The added weight of the tube adds additional costs to shipping and shipping.

[0004] Many metal extrusion devices and methods have been developed for extruding tubes from billets using a stamping machine, mold and mandrel. However, there is no known device or system for extruding a unitary tube having a uniform inner diameter and having both ends of the tube having an outer diameter greater than the outer diameter of the middle section of the tube. These and other difficulties experienced by prior art tube extrusion equipment or methods are obviated by the present invention. Therefore, a primary object of the present invention is to extrude a tube from a metal billet to produce an integrally formed tube having a constant or uniform inner diameter and an intermediate section having an outer diameter smaller than the outer diameter of each of the end sections of the tube. To provide an apparatus for the same.

It is a further object of the present invention to provide an apparatus for extruding a tube as described above from a metal billet in a single continuous extrusion operation.

It is another object of the present invention to provide a method for extruding a tube from a metal billet having a uniform inner diameter and an intermediate section having an outer diameter smaller than the outer diameter of the end sections of the tube.

It is a further object of the present invention to provide a method for extruding a tube as described above from a metal billet in a single continuous process.

Yet another object of the present invention is to use a metal extruder for extruding a tube from a metal billet having a uniform inner diameter and an intermediate section having an outer diameter smaller than the outer diameter of the end sections of the tube. It is to provide a device having an outer non-uniform configuration mandrel.

Another object of the invention is that the middle section of the tube has an outer diameter smaller than the outer diameter of each end section of the tube, and one end section of the tube is smaller than the inner diameter of the middle section and the other end section of the tube. It is to provide an apparatus for extruding a tube having a small inner diameter from a metal billet.

[0010] In view of these and other objects, it will be apparent to those skilled in the art that the present invention resides in combinations of the description portion with the subject matter of the claims.

SUMMARY OF THE INVENTION An apparatus and method for extruding a metal tube having a substantially uniform inner diameter. The front and rear end sections of the tube are thicker than the middle section of the tube. A heated metal billet having a cylindrical vertical hole is inserted into the rear opening of the cylindrical hole of the stationary container. An inner mold that is movable in two parts is installed in the hole of the container adjacent to the front end of the container, and the outer mold is installed outside the container adjacent to the front end of the container. The inner mold has a relatively small cylindrical hole. The outer mold has a relatively large cylindrical hole. The billet is moved along the central longitudinal axis within the bore of the container by a stamping machine that includes a circular forward pressing surface and a mandrel extending forward from the circular forward pressing surface toward the billet. The mandrel has a cylindrical, large-diameter rear part, a cylindrical, relatively small-diameter middle part, and a frusto-conical front part that tapers outward in the forward direction from the diameter of the middle part to the diameter of the front part. And Metal from the billet is pushed through the inner hole around the small diameter portion of the mandrel by moving the stamping machine forward a first distance to extrude the temporary front end area of the tube. To push the metal from the billet through the inner hole around the large diameter part of the mandrel, extruding the middle part of the tube and passing the temporary front end area of the tube beyond the tapered front part of the mandrel,
The press is moved a second distance forward. This causes the temporary front end area of the tube to expand transversely to its central longitudinal axis to an inner diameter equal to the inner diameter of the intermediate section and a wall thickness greater than the wall thickness of the intermediate section of the tube. The metal from the billet is forced through an outer die hole around the rear of the mandrel to remove the rear end section of the tube having an inner diameter equal to the inner diameter of the middle section of the tube and a wall thickness greater than the wall thickness of the middle section of the tube. To extrude, the inner die is removed from the container and the die is moved a third distance forward.

DETAILED DESCRIPTION OF THE INVENTION Referring first to FIGS. 19a, 19b, 19c and 19d, a tube extrusion apparatus of the present invention is indicated generally by the reference numeral 10. The apparatus 10 includes a rear machine base 72 and a front machine base 70 connected to the rear machine base by four connecting rods 74. The stamping machine, indicated generally by the reference numeral 13,
Machine bases 70 and 72 for longitudinal (longitudinal) movement along central longitudinal axis 18.
It is attached to the inter-pipe extrusion device 10.

The press machine 13 includes a crosshead 78 installed between machine bases 70 and 72. The piston 75 is connected to the rear side of the crosshead 78 via a horizontal connector 79. The piston 75 is a single-acting hydraulic (/ water pressure) fixed to the rear machine base 72.
Hereinafter, "hydraulic pressure" includes hydraulic pressure. ) Slidably mounted in cylinder 77.
The cylinder 77 is connected to a high-pressure hydraulic source (not shown) via a hydraulic line 73. The crosshead 78 is supported by the pair of vertical paths 81 and guided by the connecting rail 74 for vertical reciprocation along the longitudinal axis 18. The crosshead 78 has a horizontal hole 65 coaxial with the longitudinal axis 18. The double-acting hydraulic cylinder 81 is fixed to a hydraulic cylinder 77 via a structural support 82. The piston, indicated generally by the reference numeral 85, comprises a piston head 8 slidably mounted in a cylinder 81.
9 and a piston rod 93 extending from the cylinder 81 and fixed to the upper end of the crosshead 78. The cylinder 81 is connected to a high-pressure hydraulic source (not shown) via a hydraulic line 76. Actuation of the cylinder 77 moves the piston 75 and the crosshead 78 forward toward the front machine base 70. The relatively large cylinder 77 provides the large force required to push the billet through a mold structure, described below, at the front end of the extruder. The crosshead 78 and the piston 75 are moved back to their starting position by actuating the cylinder 81,
Therefore, the head 89 is moved backward in the cylinder 81. The press 13 also includes a cylindrical housing or stem 36 secured to the front side of the crosshead 78 and extending forward along the longitudinal axis 18. The double-acting hydraulic cylinder 69 is fixed to the rear side of the crosshead 78 and is connected to a high-pressure hydraulic source via a hydraulic line 68.

The stem 36 has a chamber 40 and a front end 47 that includes a front opening 49 into the chamber 40. The push ring 38 is installed in the front opening 49 of the housing 36 and includes a cylindrical hole 42 and a circular front push surface 39. The mandrel 44 is located within the chamber 40 and has a rear end 45 formed for coupling to a front end of a drive rod 46. The bush 59 is fastened to the front end of the drive rod 46 with a play in the stem 36. This helps to support the drive rod 46 and keep the mandrel 44 centered. The rear end of the drive rod 46 is connected to a piston 71 slidably mounted in a cylinder 69. The cylinder 69 allows the mandrel 44 to be selectively movable forward and rearward along the longitudinal axis 18 relative to the stem 36. Mandrel 44 is coaxial with central longitudinal axis 18. The mandrel 44 has a cylindrical rear portion 48, a reduced-diameter cylindrical intermediate portion 50, and a frustoconical front portion 52 tapered (gradient) outward from the reduced-diameter intermediate portion 50 to the front end of the mandrel. The foremost end of the mandrel 44 has the same diameter as the diameter of the rear part 48. Mandrel 44 extends freely through aperture 42 in push ring 38. The push ring 38 is not attached to the stem 36,
Supported by mandrel 44.

The housing or container 12 is supported on a front machine base 70. The housing 12 is fixed to a pair of opposing push connection arms 80. The connecting arm 80 is secured to the rearwardly extending ends 85 of a pair of pistons, indicated generally by the reference numeral 84. The front end of the piston 84 is slidably mounted in a double acting hydraulic cylinder 88 connected to a high pressure hydraulic source via a hydraulic line 90. The hydraulic cylinder 88 is fixed to the front machine base 70. Housing 12 houses a cylindrical tube or liner 14 having a circular hole 16 coaxial with longitudinal axis 18. The hole 16 has a circular rear opening 15 and a circular front opening 17. Referring also to FIG. 1 and FIG.
0 is located in the hole 16 adjacent to the front opening 17 of the hole. Inner die 20 is split laterally along line 21 to form two separable halves 20a, 20b. An outer mold assembly, indicated generally by the reference numeral 23, is located outside the front opening 17 of the hole 16. The outer die assembly 23 includes a die holder 24 having a hole 37, a rear end 41, and a front end 43. The outer mold 26 is located in the hole 37 and the rear end 4 of the mold holder 24.
1 is installed. The back plate 30 is installed at the front end 43 of the mold holder 24. Outer die 26
Has a circular hole 28. The back plate 30 has a circular hole 32. The diameter of the hole 32 is the hole 28
Slightly larger than the diameter of The hole 22 of the inner mold 20 has a diameter smaller than the diameter of the hole 28.

The tube to be formed by the extrusion device 10 of the present invention is formed from a cylindrical billet 54 having a cylindrical vertical hole 56. The dimensions of the billet 54 include a specified amount of clearance between the inner surface of the liner 14 forming the hole 16 and the outer surface of the billet. The diameter of the hole 56 in the billet 54 has a defined clearance with respect to the outer diameter of the mandrel portions 48,52. The stem 36 of the stamping machine 13 moves along the axis 18 and applies the full forward force of the stamping machine 13 to the billet 54.

The outer die assembly 23 is installed in a movable housing, that is, a retaining ring 92 installed at the rear end of the outer die carrier 98. The mold carrier 98 is installed in a horizontal chamber 100 in the front machine base 70. The chamber 100 has a rear opening 103 and a front opening 99. The carrier 98 has a central horizontal hole 97 having a front opening 86 and a rear opening 87. A rear portion of the hole 97 is provided with a counter hole 96 for receiving the retaining ring 92 and the outer die assembly 23.
Having. The stop plate 94 is installed at the front end of the counter hole portion of the hole 97. The stop plate 94 has a hole 91 having a larger diameter than the hole 32 of the back plate 30.

The outer carrier 98 is maintained at the rear end of the chamber 100 by a releasable stop mechanism indicated generally by the reference numeral 102. The stop mechanism 102 is connected to the chamber 10
A pair of opposing gates 104 slidably mounted in the horizontal hole 101 crossing the zero.
including. Each gate 104 is connected to one end of a piston 108. Each piston 1
08 is slidably mounted in the hydraulic cylinder 110. Each hydraulic cylinder 110 is fixed to the front machine base 70. Hydraulic cylinder 110 can be controlled to selectively move gate 104 from an operative position, as shown in FIG. 19d, where gate 104 is located within chamber 100, to a non-operating position where gate 104 is outside chamber 100. It is. When the gates 104 are in the operating position, they prevent any forward movement of the outer carrier 98 and move the outer assembly 23 to the container 1.
2 and the front end side of the inner mold 20. When the gate 104 is in the non-operation position,
Outer carrier 98 is movable from chamber 100 through front opening 99.

The guide tube 95 is fixed to the front side of the stop plate 94. The guide tube 95 is coaxial with the longitudinal axis 18 and extends forward through the front opening 99. The table 112 is fixed to the guide tube 95 and extends below the tube 95. The plurality of guide rollers 114 are installed on the upper surface of the table 112.

Having described the details of the tube forming apparatus of the present invention, the double-ended upset tube semi-finished product is formed according to the following description.

Referring to FIG. 1, the mandrel 44 includes a billet 54 and a mandrel 44 and a chamber 16.
Are shown retracted into the stem 36 to allow placement between them.
Billet 54 is then loaded into hole 16 of container 12. Once the billet 54 has been loaded into the hole 16 as shown in FIG. 4, the cylinder 69 is actuated to urge the driver 46 forward against the crosshead 78 and stem 36. As such, the mandrel 44 extends forward with respect to the stem 36 by the driver 46 so that the rear portion 48 of the mandrel is at the front end of the stem 36 and within the bore 42 of the push ring 38. At this point, the mandrel 44 is maintained in a fixed position relative to the ring 38. The cylinder 77 is operated, and the crosshead 78, the stem 36, the mandrel 4
The press machine 13 including the press ring 4 and the press ring 38 is moved forward as a single unit. The stamping machine 13 is moved forward along the longitudinal axis 18 as shown in FIG. 5, so that the mandrel 44 has holes 56 in the billet 54, holes 22 in the inner mold 20,
It extends through a hole 28 in the outer die 26 and a hole 32 in the back plate 30. The stem 36 also enters the hole 16 as shown in FIG. Immediately before applying the forward compressive force to billet 54, push ring 38 is adjacent to the rear end of billet 54, as shown in FIG.

A preferred variant of this first step is to operate cylinder 69 and push mandrel 44 through hole 56 in billet 54 while the billet is supported on the movable carriage. The cylinder 77 is operated, and the press machine 13 is moved toward the container 12,
Thereby, the mandrel 44 and billet 54 are transported into the hole 16 of the container to the position shown in FIG.

The billet is pressed against the rear end of the inner mold 20 by the additional forward movement of the stamping machine 13. The small forward motion of the press 13 presses the billet and pushes the metal from the billet to completely fill the space between the inner surface of the liner 14 and the billet.
The metal at the front end of the billet 54 is also pushed inwardly toward the reduced diameter middle portion 48 of the mandrel 44 to form an inner ridge or "upset" 60, as shown in FIG. At this point, the forward force of stem 36 is compressing billet 54. Thus, the billet is slightly reduced in length, and the corresponding billet amount is converted to the gap between the liner 14 and the billet 54 and the gap between the mandrel and the billet, forming the "upset" 60. The location of the intersection between the reduced diameter middle portion 50 of the mandrel and the rear portion 48 of the mandrel, relative to the inner mold, defines a temporary forward or "pin" section 62 of the tube, as shown in FIG.

The continuous extrusion of the billet 54 by the forward movement of the stem 36 over the first distance causes the metal from the billet to displace the first annular opening or gap 51 between the inner surface of the inner mold 20 and the reduced diameter intermediate portion 50 of the mandrel. Through to form a temporary cylindrical front end section 62 of the tube, as shown in FIG. The temporary front end area 62 eventually becomes the "pin" or front end area of the tube. The middle section 64 and the front section 67 of the tube are used to
It is formed by moving forward over an interval. At this point,
The cylindrical large diameter rear portion 48 of the mandrel reaches the rear portion of the inner mold 20. As shown in FIG. 8, when the rear part 48 of the mandrel enters the hole 22 of the inner mold 20, a second annular opening 53 is formed between the inner surface of the inner mold 20 and the rear part 50 of the mandrel. The inside diameter of the second annular opening 53 is larger than the inside diameter of the first opening 51. This also means that the second annular opening 53 is narrower than the first annular opening 51. Thus, the metal from billet 54 is pushed into gap 53 by forward pressure, such as a tubular extrudate having a smaller wall thickness. This begins to form a cylindrical intermediate section 64 of the tube. At the same time, the temporary front end section 62 of the tube reaches the tapered front section 52 of the mandrel and begins to expand laterally of the axis 18, as shown in FIG. The extruded tube is several times longer than the billet since the cross section of the billet 54 is much larger than the cross section of the finished tube. The length of the extruded tube is determined by the ratio of the cross-sectional area of the billet to the cross-sectional area of the tube (ie, the extrusion ratio). For example, at an extrusion ratio of 12: 1, a 12-inch extruded tube is formed each time the press 13 is advanced by 1 inch. This extension at the point of extrusion causes the extruded tube to slide over the outer diameter of the mandrel 44 because the mandrel is maintained in a fixed relationship to the housing or stem 36.

FIG. 9 illustrates further compression of the billet 54, extension of the middle section 64 of the tube, and continuation of the temporary front end section 62 of the tube as it is pressed onto the tapered front end 52 of the mandrel 44. It shows a wide spread.

FIGS. 10 and 11 show the completion of the enlargement process for the front end section of the tube. 10 since the front end of the temporary front end section 62 of the tube passes through the front end of the tapered front portion 52 of the mandrel.
The area 62 becomes cylindrical as shown in FIG. Also, the enlarged front end area 62
Is the same as the inside diameter of the intermediate section 64. The temporary front end section 62 of the tube is shown in full scale in FIG. 11, thus completing the formation of the front or “pin” end section of the tube, which is identified by reference numeral 67.

As the stem 36 continues to move forward, the length of the middle section 64 of the tube gradually increases until the required length of tube is extruded, as shown in FIG. Middle section of pipe 6
After the formation of the cylinder 4, the cylinder 77 is simultaneously stopped and the cylinders 81 and 85 are operated to move the stem 36 and the container 12 backward. Billet 54 and the partially extruded tube also move rearwardly with container 12, as shown in FIG. This creates a small gap between the container 12 and the mold holder 24 and removes the forward pressure on the mold carrier 98. The cylinder 110 is then actuated to remove the gate 104 from the chamber 100 and the movable carrier 98 is moved forward, creating a gap 57 between the mold holder 24 and the container 12, as shown in FIG. . The gap 57 is wider than the inner mold 20. The operation of the cylinder 81 is stopped and the cylinder 77 is operated again to move the stem 36 forward. This forces the inner mold forward, out of the container 12 and into the space 57, as shown in FIG.
As shown in FIG. 16, when the inner die 20 passes through the front opening 17 of the hole 16, the inner die 2
The zero halves separate and fall away from the middle section 64 of the tube. The housing 98 is moved rearward, and the stem 36 and the container 12 are moved to the rear opening 103 of the chamber 100.
17 so that the mold holder 24 contacts the front surface of the container 12 as shown in FIG. When the cylinder 110 is operated, the gate 104 is moved to the mold carrier 9.
8 Return to the front room 100.

The remainder of billet 54 is used to form the rear or “box” area of the tube.

The cylinder 77 is operated to move the press machine 13 and the stem 36 forward by a third distance. The space between the rear portion 48 of the mandrel and the inner surface of the bore 28 forms a third annular opening or gap 55. The forward movement of the press machine 13 at the third interval is performed by the billet 54.
Through the third annular opening or gap 55. Outer die 26 hole 2
8 has a larger diameter than the hole 22 of the inner mold 20, so that the thickness of the annular opening or gap 55 is greater than the thickness of the second annular opening or gap 53. As such, the metal from billet 54 that is forced through opening 55 forms a relatively thick rear end section 66 of the tube, as shown in FIG. The outer diameter of the rear end section 66 is substantially larger than the outer diameter of the middle section 64 of the tube. At this point, the extrusion of the tube is complete. After the entire desired length of the tube has been extruded, a small non-extruded portion of billet 54 remains. The non-extrusion part is shown in FIG.
At 68. The non-extrusion section 68 operates the cylinder 69 to move the mandrel out of the pushed-out tube at the rear,
To move the container 12 backwards, it can be removed from the tube in the extruder. The retreating movement of the container 12 pushes the non-extrusion part 68 of the billet out of the bore 16, where it can be cut from the tube end. Preferably, the extruded tube including the non-extrusion section 68 is moved a short distance backward to facilitate removal of the non-extrusion section 68. The extruded tubes are removed by activating the cylinder 110 and moving the gates 104 out of the chamber 100 to their inactive position. Mold housing 9
8 is removed from the chamber 100 through the front opening 99. This is because the extrusion tube has a front opening 9
9 to be removed from the room. The non-extruded portion 68 can be removed from the rear end of the extruded tube by any desired means, such as shearing, sawing, grinding, melting, laser cutting, and the like. The extruded tube is then removed from chamber 100. Extruded tubing is a blank tube forming for later finishing. The ends of the tube are threaded and machined in a conventional manner to form a finished tube.

Referring to FIG. 20, a modified mandrel, indicated generally by the reference numeral 44 ′, is shown in the container 12 during the process of expanding the front end section of the tube. Mandrel 44 '
Has a cylindrical rear portion 48 ', a reduced diameter cylindrical intermediate portion 50', and a frustoconical front portion 52 'that slopes outwardly from the reduced diameter intermediate portion 50' to the front end of the mandrel. The mandrel 44 'is identical to the mandrel 44 with respect to the rear and middle portions of the mandrel. However, the mandrel 44 'differs from the mandrel 44 with respect to the frustoconical front of the mandrel. The outer diameter of the front end of the mandrel 44 'is larger than the outer diameter of the intermediate portion 50',
And it is smaller than the outer diameter of the rear part 48 '. The front end of the temporary front end section 64 of the pipe is the mandrel 4
Since it passes through the front end of the taper portion 52 'of 4', as shown in FIG.
2 is cylindrical. However, the inside diameter of the enlarged front end section 62 is smaller than the middle section 64 of the tube.
Smaller than the inner diameter of.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of the main functional components of an extrusion apparatus according to the present invention for forming a double-ended upset tube.

FIG. 2 is a side view of a mandrel portion of the device.

FIG. 3 is a rear view of a two-part mold that also forms part of the apparatus.

FIG. 4 is an operational drawing showing the formation of the front end and the middle section of the tube.

FIG. 5 is an operational drawing showing the formation of the front end and the middle section of the tube.

FIG. 6 is an operational drawing showing the formation of the front end and the middle section of the tube.

FIG. 7 is an operational drawing showing the formation of the front end and the middle section of the tube.

FIG. 8 is an operational drawing showing the formation of the front end and the middle section of the tube.

FIG. 9 is an operational drawing showing the formation of the front end and the middle section of the tube.

FIG. 10 is an operational drawing showing the formation of the front end and the middle section of the tube.

FIG. 11 is an operational diagram showing the formation of a front end and an intermediate section of a tube.

FIG. 12 is an operational drawing showing the formation of the front end and the middle section of the tube.

FIG. 13 is an operational drawing showing the formation of the rear section of the tube.

FIG. 14 is an operational drawing showing the formation of the rear section of the tube.

FIG. 15 is an operational drawing showing the formation of the rear section of the tube.

FIG. 16 is an operational drawing showing the formation of the rear section of the tube.

FIG. 17 is an operational drawing showing the formation of the rear section of the tube.

FIG. 18 is an operational drawing showing the formation of the rear section of the tube.

FIG. 19 is a longitudinal sectional view (FIGS. 19a, 19b, 19c and 19d) showing the entire extrusion device according to the present invention, which can be connected along common lines AA, BB and CC. .

FIG. 20 is a view similar to FIG. 10 showing a modified mandrel;

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CR, CU, CZ, DE, DK, DM, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID , IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW The press machine is moved forward by the second distance. The metal from the billet is forced through a relatively large hole in the second mold (53) around the rear (48) of the mandrel, forming a rear end section (66) of the tube. It is moved forward a third distance.

Claims (33)

[Claims] 1. A metal having a substantially uniform inner diameter and having a front end section, a rear end section, and an intermediate section having an outer diameter substantially smaller than the outer diameter of each of the front and rear end sections. An apparatus for extruding a tube, comprising: (a) a machine frame; (b) a central longitudinal axis for receiving a cylindrical metal billet supported by the machine frame and having a central longitudinal axis and a vertical cylindrical hole. A container having a vertical cylindrical first hole coaxial with the axis and having a front opening to the first hole and a rear opening to the first hole; and (c) a cylindrical shape coaxial with the first hole. Two halves having a second hole and having an outer diameter equal to the diameter of the first hole, and the second hole having a diameter smaller than the diameter of the first hole and being substantially equal. Through the front opening from an inner position adjacent to the front opening in the first hole to an outer position outside the first hole. A cylindrical inner mold movable along the longitudinal axis; and (d) a vertical cylindrical third die installed in front of the container and coaxial with the first and second holes and having a diameter larger than the second hole. An outer mold assembly having a hole, wherein one of the outer mold assembly and the container has an operating position in which the container and the outer mold assembly are adjacent at the front opening, and the outer mold assembly and the container have the inner mold removed from the apparatus. An outer mold assembly movable along a central longitudinal axis between a non-operating position sufficiently spaced to be movable to an outer position for removal; and (e) installed behind the container. And a movable front surface that is movable along the central longitudinal axis in a direction toward and away from the container, and faces a rear opening of the container,
A mandrel extending forward from the pushing surface toward the rear opening, wherein the pushing surface and the mandrel are coaxial with the first hole, and the pushing surface extends the pushing surface longitudinally into the first hole. A cylindrical rear portion having an outer diameter substantially the same as the inner diameter of the first hole and having a clearance smaller than the inner diameter of the second hole, with sufficient clearance to allow movement of the first hole; A cylindrical intermediate portion having an outer diameter smaller than the outer diameter of the rear portion, and a truncated cone extending from the intermediate portion forward from an outer diameter equal to the outer diameter of the intermediate portion to an outer diameter substantially equal to the outer diameter of the rear portion. And (f) an actuator for moving one of the outer mold assembly and the container along the longitudinal axis with respect to the other of the outer mold assembly and the container. 2. Extruding metal from a billet through a second hole around the middle to extrude a temporary front end area of the tube having an outer diameter equal to the diameter of the second hole and an inner diameter equal to the diameter of the middle. Therefore, the billet is pushed forward by the stamping machine,
When the stamping machine is pushed a first distance forward along the central longitudinal axis to a point where it engages the inner die and the rear is at the rear end of the second hole, the longitudinal length of each part of the mandrel is For the longitudinal and specific billet lengths of the mold, the intermediate portion will be in the second hole, and the forward movement of the second interval along the central longitudinal axis of the stamping machine while the rear portion is in the second hole, Push the metal from the billet through a second hole around the back of the mandrel,
Extruding an intermediate section of the tube having an outer diameter equal to the inner diameter of the bore and an inner diameter equal to the rear outer diameter, the forward movement of the second interval of the stamping machine also causes the temporary front end area to extend transversely of the central longitudinal axis. Extending the temporary front end section of the tube beyond the front of the mandrel to form an enlarged front end section of the tube having an inner diameter equal to the outer diameter of the rear of the mandrel and a thickness greater than the thickness of the middle section of the tube. A third interval of advancement along the central longitudinal axis of the stamping machine, which removes the metal from the billet to the rear of the mandrel after removal of the inner mold from the apparatus and while the outer mold assembly is in the operating position. 2. The apparatus of claim 1 wherein the tube is pushed through a surrounding third hole to extrude a rear section of the tube having an inner diameter equal to the rear outer diameter and an outer diameter equal to the inner diameter of the third hole. 3. The outer mold assembly comprises: (a) a mold holder having a fourth hole and having a rear end and a front end; and (b) a rear end in the fourth hole of the mold holder. And (c) a cylindrical fifth hole having a diameter larger than the diameter of the fourth hole, which is installed at a front end of the fourth hole of the mold holder. The tube extrusion device according to claim 1, further comprising a stop member having the stop member. 4. The mandrel has a rear end, and the stamping machine includes: (a) a housing having a chamber for accommodating the mandrel, and a front end having a front opening to the chamber; (B) a push ring installed at the front opening of the front end of the housing and including a front pressing surface and a cylindrical hole having an inner diameter substantially equal to the outer diameter of the rear portion of the mandrel; The mandrel moves along the central longitudinal axis between the rear withdrawal position in the room and the forward extension position with the rear of the mandrel in the hole of the push ring and the rest of the mandrel in front of the push ring. 2. A tube extrusion device according to claim 1, further comprising a driving body suitably connected to a rear portion of the tube. 5. The apparatus according to claim 1, further comprising an actuator for moving one of the outer mold assembly and the container along the central longitudinal axis relative to the other of the outer mold assembly and the container. 6. The actuator comprises: (a) a cylinder fixed to the machine frame; and (b) a rear portion extending rearward of the cylinder, and slidable in a cylinder appropriately connected to a container. The tube pushing device according to claim 5, which is a fluid actuator including a simple piston. 7. One of the first fluid actuators is on one side of the central longitudinal axis, and one of the second fluid actuators is on the opposite side of the central longitudinal axis, and the container has first and second fluid actuators. 7. The apparatus according to claim 6, wherein the apparatus is fixed to a piston of a fluid actuator. 8. The outer mold assembly comprises: (a) a carrier having a central hole coaxial with a central longitudinal axis, and the central hole having a front opening and a rear opening; and (b) a cylindrical cylindrical member. A mold holder having four holes, a rear end, and a front end, and being located at a front opening in the center hole; (c) being installed at a rear end in the fourth hole of the outer die assembly; 2. An outer die including a third hole, and a stop member provided at a front end of the holder in the fourth hole and having a cylindrical fifth hole having a diameter larger than the diameter of the fourth hole. A tube extrusion device as described. 9. The apparatus of claim 8, wherein the outer die assembly further comprises a stop ring in the center hole surrounding the die holder. 10. The outer die assembly has a cylindrical hole coaxial with the central longitudinal axis and having a diameter larger than the diameter of the fifth hole and smaller than the diameter of the fourth hole. 10. The tube extrusion device according to claim 9, further comprising a stop plate inside and in front of the mold holder. 11. The outer die assembly is secured to a stop plate and extends forward through a front opening of the center hole, and has an inner diameter at least as large as the inner diameter of the hole in the stop plate. The tube extrusion device according to claim 10, further comprising a guide tube. 12. The machine frame includes a chamber having a rear opening and a front opening, and the outer die assembly is installed in the chamber for longitudinal movement along a central longitudinal axis, and the apparatus. The apparatus of claim 1 further comprising a releasable stop mechanism for maintaining the outer mold assembly releasable in said chamber. 13. An operating position in which said machine frame extends laterally of a central longitudinal axis and has a transverse hole intersecting said chamber, and wherein said releasable stop mechanism has at least a portion of a gate in the room. 13. The apparatus according to claim 12, further comprising a gate slidably mounted in the lateral hole between the gate and a non-operating position where the gate is outside the room. 14. The tube extruder of claim 13, wherein said releasable stop mechanism further comprises an actuator for selectively moving the gate to a working or non-working position. 15. The actuator of claim 1, wherein the actuator is a fluid actuator.
5. The tube extrusion device according to 4. 16. The apparatus of claim 1 wherein said apparatus further comprises a guide table in front of the outer mold assembly for supporting and guiding the tubes as the tubes are extruded. 17. The tube extruder according to claim 16, wherein the guide table has an upwardly extending roller for supporting the extrusion tube. 18. The apparatus according to claim 17, wherein the apparatus further comprises a guide tube extending from the outer mold assembly to the guide table for guiding the extrusion tube from the outer mold assembly to the guide table. 19. A uniform inner diameter of a first dimension, a front end area, a rear end area, and an intermediate area between the front and rear end areas, wherein the intermediate area has an outer diameter of a second dimension. A mandrel for use in a metal extruder for extruding a metal tube having a front end and a rear end area each having an outer diameter greater than a second dimension, wherein: (a) a circle having an outer diameter equal to the first dimension; A columnar rear portion; (b) a columnar intermediate portion having an outer diameter substantially smaller than the outer diameter of the rear portion; and (c) an outer diameter equal to the outer diameter of the intermediate portion to an outer diameter equal to the outer diameter of the rear portion. A rear portion having a frusto-conical outer surface extending outwardly from the middle portion. 20. A cylindrical metal tube having a constant inner diameter and having a front end section, a rear end section, and an intermediate section having an outer diameter substantially smaller than the outer diameter of each of the front and rear end sections. (A) inserting a cylindrical billet through a rear opening into a cylindrical first hole,
Disposing a billet having a cylindrical vertical hole in a first hole of a container, wherein the first hole has a central longitudinal axis, the container has a front opening to the first hole, and the first hole; An inner mold adjacent to the front opening inside and an outer mold adjacent to the front opening outside the container, and the inner mold has a cylindrical second hole having a diameter smaller than the diameter of the first hole; Type is first
Having a third hole smaller than the diameter of the hole and larger than the diameter of the second hole, and wherein the inner die comprises two separable halves; and (b) moving the die along the central longitudinal axis. Arranging, wherein the stamping machine has a circular front pressing surface facing the container, and a mandrel extending forward from the pressing surface toward the container, and wherein the pressing surface and the mandrel have a first hole. The pressing surface is coaxial and has an outer diameter substantially equal to the inner diameter of the first hole, with a clearance sufficient to allow the pressing surface to move in the longitudinal direction in the first hole. And the mandrel has a cylindrical rear portion having a diameter smaller than the second hole, a cylindrical intermediate portion having a diameter smaller than the rear portion, and a middle portion having a diameter equal to the intermediate portion to a diameter equal to the rear portion. Having a frusto-conical front extending forward from the diameter; and (c) pushing forward. When the mandrel first contacts the billet and pushes the billet against the inner mold, the mandrel extends through the hole in the billet and the intermediate portion is placed in the second hole to form a first annular opening; Moving the stamping machine along the central axis such that the junction of the part and the rear is spaced behind the inner mold; and (d) pushing metal from the billet through the first annular opening; The point where the junction of the middle and the rear is at the rear end of the second hole to extrude the temporary front end section of the tube, having an outer diameter equal to the inner diameter of the second hole and an inner diameter equal to the outer diameter of the middle portion (E) moving the temporary front end area of the tube to an inner diameter equal to the inner diameter of the middle section of the pipe and an outer diameter greater than the outer diameter of the middle section of the pipe; A second interval advance of the stamping machine to be expanded laterally of the central longitudinal axis During movement, there is a rear within the second hole to form a second annular opening, forcing metal from the billet through the second annular opening, an outer diameter equal to the inner diameter of the second hole and an inner diameter equal to the rear diameter. Extruding a middle section of the tube and moving the stamping machine a second distance forward along a central longitudinal axis to pass the temporary front end section of the tube past the front of the mandrel; (F) moving one of the outer mold and the container along the central longitudinal axis such that the outer mold is spaced from the stationary container at least equal to the longitudinal length of the inner mold; (H) removing each half of the inner mold from the tube and the mandrel, and (i) removing the inner mold from the container so that the inner mold is forward of the inner mold. And the rear is in the third circular hole to form a third annular opening Moving one of the outer mold and the container rearward along the central longitudinal axis, and (j) pushing metal from the billet through the third annular opening, the inner diameter and the third hole equal to the outer diameter of the rear. To extrude the rear section of the tube having an outer diameter equal to the inner diameter of
A tube extrusion method comprising: a step of moving a pressing machine forward by a third interval along a central longitudinal axis; and (k) a step of removing an extrusion tube from a mandrel. 21. The method of claim 20, wherein the extruded tube is removed from the mandrel by moving the mandrel backward along the central longitudinal axis until the mandrel is behind the extruded tube. 22. The step (f) according to claim 20, wherein the inner die is pushed out of the first hole.
21. The tube extrusion method according to claim 20, wherein the container is moved rearward along the central longitudinal axis with respect to the outer mold and the mandrel. 23. A method in which the non-extrusion portion of the billet remains in the first hole after the forward movement of the mandrel for the third interval, comprising: (a) moving the mandrel around the central longitudinal axis until the mandrel is behind the extrusion tube; (B) moving one of the outer mold and the container along the central longitudinal axis such that the outer mold is spaced from the container; and (c) the rear end area of the extruded tube. Removing the non-extrusion portion of the billet from the tube. 24. The method according to claim 2, wherein the non-extruded portion of the billet is pushed out from the first hole.
24. The tube extrusion method according to claim 23, wherein the container is moved rearward along the central longitudinal axis with respect to the outer mold and the mandrel in step (b) of step 3. 25. A body having a uniform inner diameter of a first dimension, a leading end section, a trailing end section, and an intermediate area between the leading and trailing end areas, and the intermediate section having an outer diameter of a second dimension. And
And extruding a cylindrical metal tube having an outer diameter greater than a second dimension at each of a front end and a rear end area, the method comprising: (a) extruding a temporary front end area of the tube having an inner diameter smaller than a first dimension. Pushing a cylindrical metal billet in a cylindrical bore of the container through a first annular opening having an inner diameter smaller than the first dimension and an outer diameter equal to the second dimension; and (b) extruding a middle section of the tube. Pushing the metal billet in the bore through a second annular opening having an inner diameter equal to one dimension and an outer diameter equal to a second dimension; and (c) enlarging the temporary front end area of the tube to an inner diameter and a second diameter equal to the first dimension. Moving the temporary front end area of the tube onto a mandrel having a frustoconical outer surface shape to form a front end area of the tube having an outer diameter greater than two dimensions; and (d) extruding the rear end area of the tube. , Equal to the first dimension Pushing a metal billet in the hole through a third annular opening having a diameter and an outer diameter greater than the third dimension. 26. A front end section, a rear end section, and an intermediate section having an outer diameter substantially smaller than an outer diameter of each of the front and rear end sections, and wherein the front end section is a rear end section and an intermediate section. An apparatus for extruding a metal tube having an inner diameter smaller than each inner diameter, comprising: (a) a machine frame; and (b) a cylindrical shape supported by the machine frame and having a central longitudinal axis and a vertical cylindrical hole. A container having a first longitudinal hole coaxial with the central longitudinal axis for receiving the metal billet, and having a front opening to the first hole and a rear opening to the first hole; (c) A second hole coaxial with the first hole, having an outer diameter equal to the diameter of the first hole, the second hole having a diameter smaller than the diameter of the first hole, and Is vertically divided into two substantially equal halves, and is located at an inner position adjacent to the front opening in the first hole. A cylindrical inner mold movable along the central longitudinal axis through the front opening from the first hole to an outside position outside the first hole, and (d) installed in front of the container and coaxial with the first and second holes. An outer mold assembly having a vertical cylindrical third hole having a diameter larger than the second hole, wherein one of the outer mold assembly and the container is in an operating position in which the container and the outer mold assembly are adjacent at a front opening. Wherein the outer mold assembly and the container are movable along a central longitudinal axis between a non-operating position spaced sufficiently to allow the inner mold to move to an outer position for removal from the apparatus. An outer die assembly; and (e) a circular front-facing surface located behind the container and movable along a central longitudinal axis in a direction toward and away from the container, and facing a rear opening of the container. When,
A mandrel extending forward from the pushing surface toward the rear opening, wherein the pushing surface and the mandrel are coaxial with the first hole, and the pushing surface extends the pushing surface longitudinally into the first hole. A cylindrical rear portion having an outer diameter substantially the same as the inner diameter of the first hole and having a clearance smaller than the inner diameter of the second hole, with sufficient clearance to allow movement of the first hole; A cylindrical intermediate portion having an outer diameter smaller than the outer diameter of the rear portion, and an outer diameter equal to the outer diameter of the intermediate portion to an outer diameter larger than the outer diameter of the intermediate portion and smaller than the outer diameter of the rear portion. (F) an actuator for moving one of the outer mold assembly and the container along the longitudinal axis with respect to the other of the outer mold assembly and the container. Equipped with a tube extrusion device. 27. A first dimension having a uniform inner diameter, a front end section, a rear end section, and an intermediate section between the front and rear end sections, wherein the intermediate section has a first dimension inner diameter and a second end. Metal extrusion for extruding a metal tube having an outer diameter of two dimensions, and each of the leading and trailing sections having an outer diameter greater than the second dimension and a leading end section having an inner diameter less than the first dimension. (C) a cylindrical rear portion having an outer diameter equal to the first dimension; (b) a cylindrical intermediate portion having an outer diameter substantially smaller than the outer diameter of the rear portion; A) a rear portion having a frustoconical outer surface extending forward from the intermediate portion to an outer diameter less than the first dimension and greater than the outer diameter of the intermediate portion from an outer diameter equal to the outer diameter of the intermediate portion. 28. A front end section, a rear end section, and an intermediate section having an outer diameter substantially smaller than an outer diameter of each of the front and rear end sections, and wherein the front end section is a rear end section and an intermediate section. A method of extruding a cylindrical metal tube having an inner diameter smaller than each inner diameter, comprising: (a) inserting a cylindrical billet into a cylindrical first hole through a rear opening;
Disposing a billet having a cylindrical vertical hole in a first hole of a container, wherein the first hole has a central longitudinal axis, the container has a front opening to the first hole, and the first hole; An inner mold adjacent to the front opening inside and an outer mold adjacent to the front opening outside the container, and the inner mold has a cylindrical second hole having a diameter smaller than the diameter of the first hole; Type is first
Having a third hole smaller than the diameter of the hole and larger than the diameter of the second hole, and wherein the inner die comprises two separable halves; and (b) moving the die along the central longitudinal axis. Arranging, wherein the stamping machine has a circular front pressing surface facing the container, and a mandrel extending forward from the pressing surface toward the container, and wherein the pressing surface and the mandrel have a first hole. The pressing surface is coaxial and has an outer diameter substantially equal to the inner diameter of the first hole, with a clearance sufficient to allow the pressing surface to move in the longitudinal direction in the first hole. And the mandrel has a cylindrical rear portion having an outer diameter smaller than the inner diameter of the second hole, a cylindrical intermediate portion having a diameter smaller than the rear portion, and an outer diameter equal to the outer diameter of the intermediate portion. Frustoconical front that extends forward from the middle to a diameter greater than the outer diameter and less than the diameter of the rear (C) when the front pressing surface first contacts the billet and presses the billet against the inner mold, the mandrel extends through the hole in the billet and the intermediate portion is placed in the second hole. Moving the stamping machine along the central axis such that the first annular opening is formed and the junction between the intermediate portion and the rear portion is spaced behind the inner mold; (d) The metal from the billet is pushed through the first annular opening and the intermediate and rear portions are extruded to extrude a temporary front end section of the tube having an outer diameter equal to the inner diameter of the second hole and an inner diameter equal to the outer diameter of the intermediate portion. Moving the stamping machine a first distance along the central axis to a point where the joint is at the rear end of the second hole; and (e) the temporary front end area of the tube is smaller than the inner diameter of the middle section of the tube. And expanded transversely to the central longitudinal axis to an outer diameter greater than the outer diameter of the middle section of the pipe. A rear portion within the second bore to form a second annular opening during the second spaced forward movement of the stamping machine for pushing metal from the billet through the second annular opening; The extruder has a central longitudinal axis for extruding an intermediate section of the tube having an outer diameter equal to the inner diameter of the pipe and an inner diameter equal to the rear diameter of the pipe and for passing the temporary front end section of the pipe past the front of the mandrel. (F) moving one of the outer mold and the container along the central longitudinal axis such that the outer mold is spaced from the stationary container at least equal to the longitudinal length of the inner mold. (G) removing the inner mold from the first hole through the front opening such that the inner mold is in front of the container; and (h) removing each of the inner mold halves from a tube and a mandrel. And (i) the outer mold is in contact with the container and the rear part is a third circle. Moving one of the outer mold and the container rearward along the central longitudinal axis so as to form a third annular opening in the hole; and (j) pushing metal from the billet through the third annular opening. To extrude a rear section of the tube having an inner diameter equal to the outer diameter of the rear and an outer diameter equal to the inner diameter of the third hole,
A tube extrusion method comprising: a step of moving a pressing machine forward by a third interval along a central longitudinal axis; and (k) a step of removing an extrusion tube from a mandrel. 29. The method of claim 28, wherein the extruded tube is removed from the mandrel by moving the mandrel backward along the central longitudinal axis until the mandrel is behind the extruded tube. 30. The step (f) according to claim 20, wherein the inner die is pushed out of the first hole.
29. The method of claim 28, wherein the container is moved rearwardly along a central longitudinal axis relative to the outer mold and mandrel located at. 31. A method wherein the non-extrusion portion of the billet remains in the first bore after a third forward movement of the mandrel, the method comprising: (a) centering the mandrel on the central longitudinal axis until the mandrel is behind the extrusion tube; (B) moving one of the outer mold and the container forward along the central longitudinal axis such that the outer mold is spaced from the container; and (c) after the extruded tube. Removing the non-extrusion portion of the billet from the end section. 32. The non-extrusion portion of the billet is pushed out from the first hole, so that the billet is pushed out.
32. The method according to claim 31, wherein the container is moved rearward along the central longitudinal axis with respect to the outer mold and the mandrel in step (b) of step 3. 33. A front end section, a rear end section, and an intermediate section between the front and rear end sections, the intermediate section having an inner diameter of a first dimension and an outer diameter of a second dimension, and ,
A cylindrical metal tube having a rear end section having an inner diameter of a first dimension and an outer diameter greater than a second dimension, and a front end section having an outer diameter of greater than a second dimension and an inner diameter of a third dimension smaller than the first dimension; (A) through a first annular opening having an inner diameter smaller than a third dimension and an outer diameter equal to a second dimension to extrude a temporary front end area of the tube having an inner diameter smaller than a third dimension. Pressing a metal billet in a cylindrical bore of the container; and (b) pressing a metal in the bore through a second annular opening having an inner diameter equal to the first dimension and an outer diameter equal to the second dimension to extrude an intermediate section of the tube. Pressing a billet; and (c) expanding the temporary front end area of the tube to form a temporary front end area of the tube having an inner diameter equal to the third dimension and an outer diameter greater than the second dimension. With a truncated cone outer surface Moving up; and (d) pushing a metal billet in the bore through a third annular opening having an inner diameter greater than the first dimension and an outer diameter greater than the second dimension to extrude a rear end section of the tube. Equipped tube extrusion method.