TW201350224A - Method and device for the manufacture of metallic components comprising a shaft which is deformed along its longitudinal axis to at least one helix - Google Patents

Abstract

The invention relates to a method for producing metal components with a shank that is deformed along the longitudinal axis thereof into at least one helix, and a device suitable for performing said method. Proceeding from the disadvantages of the known prior art, a method suitable for the economical mass production of components having more stable helices is to be created. For this purpose, a blank (7) is introduced into a guide (12), and then in at least one multi-section split mould (10) with at least two movable jaws (11), the internal wall of which is provided with a helically formed contour (11a) designed as a negative, through impact extrusion by means of an extrusion die (13) which strikes the free end of the blank (7), the shank (8) of the blank is extruded through an outlet opening in the split mould (10), the centre of area of which is off-set from the centre line M of the tool (10) or of the component (1) in an offset direction, with the result that the shank (8) of the blank (7) is deformed into at least one stable strand (4) in the form of a helix.

Description

Method and apparatus for manufacturing a metal component having a shaft that forms at least one spiral along its longitudinal axis

The present invention relates to a method of making a metal component having a shaft, wherein the shaft forms at least one helix along its longitudinal axis, and a device suitable for carrying out the method.

Metal components consisting of a shaft portion and a head are often used in the fastening connection technique, wherein the shaft portion is usually a cylindrical bolt or pin, and the shaft surface forms a thread, the fastener and the threaded coupling finger Screws, bolts, dowels or anchor bolts.

In addition, metal rotary worms such as screw conveyors, screw feeders, screw conveyors, hybrid screws or worm gear drives are also widely used. These components are also composed of a shaft portion and a head portion, and the surface of the shaft portion is formed into a spiral or a spiral structure. A grooved thread structure is formed on the surface of the worm gear for power transmission, and the head of the worm gear is clamped into the chuck and connected to a rotary drive.

The WO 2010/142458 A2 patent discloses a method of manufacturing a metal elongate member having a spiral slot, in particular a method of manufacturing a spiral drill or a screw, first placing an unheated blank into a guide die, and placing the embryo The material is introduced into a dental mold and then cold deformed. The dental mold has at least two movable dental plates, and the inner wall of the dental plate has at least one bottom mold portion having a thread profile to form a spiral groove. The punch is axially moved to abut the free end of the blank located in the guide die to complete the cold deformation. Under pressure, the billet can be partially squeezed through the central opening of the closed cavities without preheating. A spiral groove is formed on the surface of the blank through cold plastic deformation while being in contact with the contour of the mold. After the cold deformation is completed, the cavities are opened, and the drill or the screw processed from the billet in the cavities is taken out.

In addition, a shaft portion or a head or a combination of a shaft portion and a head portion may be formed on the billet by other cold deformation steps before extrusion.

European Patent EP 2 156 909 B1 discloses a method of manufacturing a metal fastener or a metal connector having a radially external thread such as a screw or bolt.

The processed blank is placed in a multi-piece dental mold. At this time, the blank is located in the axially extending groove of the opened dental plate, and the dental plate of the punching die is formed on the inner wall thereof. The bottom mold of the profile to form a radially external thread on the billet. Under the action of a radial force, the dental plate is closed, and a thread is formed on the shaft portion of the blank to pass through the groove in the shaft portion of the blank to prevent the material from entering between the dental plates of the dental mold during the extrusion process. Also, during the stamping process, radial threads are not formed at the axially extending grooves.

The German patent DE 31 16 101 C2 discloses a screw element which differs from the conventional construction described above in that the shaft of the screw element is helical or spiral, the screw shaft forming the thread of the screw.

The screw element is used for connecting a semi-rigid material, and the screw member is manufactured by winding a piece of metal wire. The lead of the screw element near the head is smaller than the lead of the screw element, and the screw element is manufactured by winding the metal wire, especially manufacturing. This method is very cumbersome in the case of strong screw elements, and in this way only screw elements with a single helix can be produced.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide a method of manufacturing a metal component which is suitable for economical and mass production of components having a structurally stable thread, and the method of the present invention can also be used to produce components having a plurality of spiral or spiral structures. Further, the present invention also provides an apparatus suitable for the manufacturing method.

For the purpose of the present invention, the present invention has the features recited in claim 1, the request item 2 to the request item 14 mainly describe the advantages of the manufacturing method of the present invention, and the request item 15 discloses a device suitable for the manufacturing method, the request item 16 to claim 25 relate to the advantages of the device.

In the manufacture of a threaded component, a solid cylindrical preform or an elongate sleeve is typically used. Of course, the blank may also be a sleeve having a solid end.

The multi-piece stamping blank can be passed through a series of complicated processing processes. Preferably, a formed blank having a shaft portion is directly applied, and the shaft portion extends longitudinally to form one or several eccentric rods. The body cylinder segment or sleeve can also be advanced into a blank having a heel or a plurality of rods, which may also be referred to as a "leg".

The following describes a cold forging method in which one or a plurality of parallelly disposed rod bodies are deformed into a spiral structure or a plurality of intertwined spiral structures.

First, the formed blank member is placed into a guiding device and then introduced into at least one multi-piece dental mold for cold forging, the dental mold having at least two movable dental plates, the inner wall of the dental plate A bottom mold having a spiral profile. The guiding device can be a guiding mold. Of course, the dental plate of the dental mold can also have a corresponding guiding device.

What is important is that the center of gravity of the die output extends in an offset direction relative to the wire in the mold or the component, and the guiding device of the blank is a part of the mold. Therefore, the center of gravity of the die output is not located in the component. The center line or the center line of the guiding device that holds the blank.

The deformation force required for cold forging is produced by a punch that abuts the free end of the blank.

By applying a pressure to the blank member, the blank member is partially pressed by the eccentric opening of the closed cavities, and the blank member is plastically deformed when it contacts the inner contour of the mold to form a spiral rod.

The shaft of the blank member forms at least one solid rod body which can have an almost constant helical cross section since the center of gravity of the jaw mold outlet extends relative to the normal from the center of gravity of the central opening of the guide.

After the extrusion is completed, the cavities are opened and the finished product having one or more helical rods is removed.

The spiral structure described above is a curve, and its radius can be constant or continuously increased or decreased.

According to another preferred embodiment of the present invention, two or a plurality of screw bodies arranged in parallel may be formed by cold forging at the same time, and all the rod bodies are not in contact with each other and are entangled with each other in the form of double-threaded screws.

According to a third embodiment of the present invention, the center of the blank member forms a first straight rod along a longitudinal central axis thereof, and the longitudinal central axis of the second rod body is offset from the longitudinal central axis of the first rod body, and a single helix is formed, the spiral line The first straight rod is wound during the pressing process, and the tip of the first straight rod is a tip portion, which can serve as the top center of the coupling member such as a screw.

The straight rod can also be formed when the blank is processed.

The element of the invention may also have at least two parallel, longitudinally extending, stabilizing rod-like arms having a helical cross-section that is either constant or continuously reduced in the direction of the punch. The shaft portion of the blank itself forms two helical rods extending from the head, the center of gravity of which has a specific distance from the longitudinal centerline of the head, the distance being generally limited to the millimeter range.

Such fasteners or threaded couplings are widely used in various forms in the industrial or construction field.

In addition, when cold or forging two or more spiral rod bodies, a core rod may be fixed at the center of the opening of the tooth decay mold, and the spiral rod body after cold forging is wound and surrounds the core rod, and after the extrusion is completed, , remove the mandrel and open the caries mold to release the mold. The mandrel can extend into the opening of the dental mold, even beyond the mold.

When the blank is a sleeve, the mandrel can extend into the upper end of the sleeve, even protruding from the sleeve, and the lower portion of the punch is also a sleeve. During the extrusion process, the punch is placed on the core rod and pressed. The finished product is longer than the blank used, that is to say, after cold forging, the length of the auger changes not only, but also the material is hardened.

All processing steps, starting with the original rod or wire segment, can be done in a multi-stage extrusion unit.

Before the cold forging process, the blank piece may be preheated according to the situation, and the blank piece may be made of different metal materials such as aluminum, copper, steel or alloy, etc., it is important that the metal material can be cold forged and deformed, and the spiral formed by cold forging processing The rod body may have different shapes of cross sections, such as a circular cross section, an oval cross section, an elliptical cross section, a polygonal cross section such as a quadrilateral or a six-deformation, etc., and the opening of the dental mold has a cross-sectional shape, and the opening of the dental plate may have a squeezing edge. The cross-sectional shape in which the pressing direction is changed, for example, the cross-section is circular at the entrance of the dentition mold, and the outlet is elliptical.

The profile of the dental plate and the mandrel can vary with the helix of the component, especially the arc length of the helix, the curvature and the torsion or the angle of the thread.

When two or more rods are spiral, the spiral rods are parallel to each other at different distances. Of course, the spiral rods can also be entangled with each other without contact. In addition, the auger body may also be composed of a straight rod and a spiral rod body, and at this time, the spiral rod body is wound around the straight rod.

The inner contour of the tooth decay mold can change the pitch between adjacent spirals according to the number of spirals. When there are two spirals, the spirals are misaligned with each other at a half turn or half pitch.

An element having a plurality of helical shanks can be fabricated by a multi-piece fang mold having an eccentrically disposed squeezing port surrounded by a periphery of the slat and a central insert. Of course, cold forging can also be performed by a small single-station dental mold, in which case a dental mold is required for each screw body.

The periphery of the spiral of the two or more helical rods is larger than, equal to or smaller than the outer diameter of the blank or the periphery of the head.

By means of the method of the invention, it is possible to produce screws, bolts and anchor bolts, such as concrete sights, positioning bolts and the like.

The auger is slightly compressed when the screw is inserted into the hole.

By means of the method of the invention it is also possible to produce a rotary screw, such as a screw for a mixing device, a conveying device or a dosing device or a transmission worm gear for transmitting power.

The fastener or threaded coupling or screw produced by the method of the present invention can be further deformed to form the head of the coupling or screw, and the formed helical shaft can be further deformed as desired.

Through the forging process, the helix angle of the helix can be reduced, and at this time, the rod body is also shortened.

4. . . element

5. . . head

6. . . Rod body

7. . . Rod body

8. . . Countersunk structure

9. . . casing

7,7’. . . Embryo

8. . . Shaft portion

8a, 8b. . . Rod body

10. . . Dental mold

11. . . Dental plate

12. . . Guide mode

12a. . . Center opening

13. . . shower

14. . . Mandrel

15. . . Output port

16. . . Outer ring

F. . . Center of gravity

M. . . Midline

Z. . . Offset direction

Figure 1 is a perspective view of three embodiments of elements molded using the method of the present invention.

Figure 2: A simplified view of a longitudinal section of a blank of a different embodiment.

Figure 3: A simplified view of the production steps A, B, C for the manufacture of a screw having a helical body.

Fig. 4 is an enlarged cross-sectional view taken along line A-A of Fig. 3.

Figure 5: Simplified drawing of production steps A, B, C for the production of screws with two augers.

Fig. 6 is an enlarged cross-sectional view taken along line A-A of Fig. 5.

Figure 7: A simplified view of steps A, B, C for making a locating pin with a double helix body.

1 is a different component 1 manufactured according to the method of the present invention, FIG. A is a countersunk screw, FIG. B is a ground anchor bolt, and FIG. C is a positioning bolt (dowel) having a head 2 and two The rods 3, 4, the rods 3, 4 are axially connected to the head 2, and the rods 3, 4 form a helix or a helix.

The rods 3, 4 extend in the longitudinal direction and are parallel to each other and are entangled with each other without contact.

The rods 3, 4 are connected to the head 2, and the center of gravity of the rods 3, 4 is offset from the center line M in the offset direction Z. Please refer to the rod body 4 shown in Fig. 2.

As shown in Figure 1, these components differ in their cross-section and the angle of the threads of the bars 3, 4 and the heads of the elements.

The countersunk screw shown in FIG. A is formed by cold forging of the solid billet, and the head 2 is solid, and the top of the head is formed with a countersunk structure 5, like the ordinary screw, the countersunk structure 5 has a glyph or Plum-shaped gap.

The element 1 shown in Figures B and C is manufactured by cold forging a set of tubular blanks.

The head 2 of the anchor bolt shown in Fig. B is a sleeve 6, each of which has an elliptical cross section and is structurally stable, and the type of anchor bolt can be used as a concrete sight.

The head 2 of the positioning pin shown in Fig. C is also a sleeve 6. As shown in FIG. C, the threading angle of the threaded body or the rod body 3, 4 of the positioning bolt is smaller than that of the anchor bolt shown in FIG. B, and the sleeve 6 of the positioning bolt has an internal thread, and a Screw the screw.

Figure 2 is a schematic illustration of various embodiments of a shaped blank that is processed into the component 1 of the invention by cold forging.

The blank member 7, 7' is composed of a shaft portion 8 and a head portion 2, and Fig. A is a first blank member 7, which is formed by a solid cylinder, and the blank member is formed by forging a metal wire segment before deformation. .

Figure B shows a second blank member 7' which differs from the first blank member 7 in that the shaft portion 8 of the second blank member 7' already has a rod body 8a, 8b having an elliptical cross section. The rods 8a, 8b are formed in a pre-processing stage.

The rods 8a, 8b are straight, wherein the shaft is located outside the central axis of the blank 7', and the rods 8a, 8b are formed into a spiral structure by cold forging as described below.

Figure C is a third blank member 7, which is a formed metal sleeve 6, as shown in Figure D, the blank member 7' is a metal sleeve 6, and the shaft portion 8 has been formed into two having an elliptical cross section. The body 8a, 8b, which is similar to the blank shown in Figure B.

The pre-formed rods 8a, 8b may also be referred to as "legs", which may have differently shaped cross sections.

The advantage of using a preform having a rod body is that only a small pressure is required, and in addition, material strength and compressibility are also important.

Figure 3 shows the production steps A, B, C of machining the cylindrical solid blank 7 into a screw having a helical body, which is arranged in anteroposterior order.

The apparatus suitable for use in the manufacturing method of the present invention comprises a dentition mold 10 having four movable dental plates 11, a guide die 12 and a punch 13, which can apply a desired pressure.

The process of cold forging a metal material using a dental mold 10 having a movable dental plate 11 is a conventional technique, and the mold may have different numbers of dental plates, such as two, three, four or five dental plates. .

The dentition mold has an axially moving outer ring 16 in which the dental plate 11 is radially movably disposed, and the outer ring 16 is sleeved on the tapered surface of the dental plate 11, as shown in step C. The outer surface of the outer ring 16 has a tapered inner surface 16 corresponding to the tapered surface.

When the fang mold is opened or closed, the outer ring 16 moves toward the punching direction or in the opposite direction, and when the fang mold is mounted to the multi-stage squeezing device, the carriage of the multi-stage squeezing device moves forward. The outer ring 16 is moved by an adapter (not shown). Of course, the dental plate 11 can also be opened or closed by other means.

The sleeve tubular guide die 12 has a central opening 12a whose cross-sectional shape matches the cross-sectional shape of the blank member 7. The blank member 7 having a head portion 2 and a shaft portion 8 is placed in the center opening 12a of the guide die 12 (step A).

The punch 13 is moved to contact the blank member 7 to perform extrusion processing.

The center of gravity F of the output die 10 surrounded by the inner wall of the dental plate 11 is offset from the longitudinal center line M of the die or blank 7 or the component 1 in the offset direction Z (Fig. 4), and only in this way can the cold forging process be performed. The at least one stable auger body 4 is formed through the bottom mold inner contour 11a of the dental plate 11, and the step B simply describes the process of forming the shaft portion into a spiral body 4. Under the action of a large pressure, the length of the rod body changes before and after the cold forging process. In detail, the formed element 1 is longer than the blank member 7 used. After the tooth plate 11 of the caries mold 10 is opened, the formed spiral element 1 is taken out (step C), and the punch 13 can also be used as an ejection device for the element 1.

The component can be subsequently processed according to the requirements of use, such as further deforming its head into a screw head (Fig. 1, Fig. a).

Referring to FIG. 5, the manufacturing process A, B, C of the solid cylindrical preform is deformed into a screw having two helical rods. Unlike the dental mold shown in Fig. 3, the dental mold 10 has two output ports 15, and the center of gravity F (dashed line) of the output port 15 is offset from the line of the mold or the element in the offset direction Z (Fig. 6). .

Further, a mandrel 14 is further fixed at the center thereof, and the mandrel 14 extends in the pressing direction toward the end surface of the blank member 7 located in the guide die 12 (step A). As shown in step B, the caries mold 10 is closed. After the tooth plate 11, the punch 13 moves axially. At this time, the blank member 7 is formed through the mold opening 15 under the action of high pressure. Since the inner contour of the mold is spiral, the two spiral rod bodies 3, 4 can be simultaneously formed. The two auger shafts 3, 4 have the same thread elevation angle and are wound around the periphery of the mandrel 14 and are not in contact with each other. After the cold forging process is completed, the mandrel is taken out, the caries mold is opened, and the component 1 is taken out.

Figure 7 is a step A, B, C for manufacturing the positioning pin, and the blank member 7 is a sleeve 6 (Fig. 2, Fig. C).

The sleeve 6 is placed in the guide die 12, and then a mandrel 14 is introduced into the sleeve from the bottom. The outer diameter of the mandrel 14 is the same as the inner diameter of the sleeve 6 to penetrate the mandrel into the top of the sleeve 6. And a gap is formed between the top of the sleeve 6. In the cold forging process, the mandrel 14 can also be used as a positioning sleeve 6.

As shown in step A, the bottom of the punch is also a sleeve. During the cold forging process, the annular end surface of the punch abuts against the top of the sleeve 6 in the extrusion direction and presses the sleeve through the mold opening 15. 6. At this time, the sleeve-like end of the punch 13 is sleeved on the mandrel 14.

The shaft 8 of the sleeve 6 is deformed into a double spiral rod 3, 4 by cold extrusion, and the spiral rod is wound around the periphery of the core rod 14 (step B). After the extrusion is completed, the core rod 14 is taken out. The jaw mold 10 is opened, and the component 1 (positioning pin) is released.

As shown in Fig. 1C, the blanks having the two rods 8a, 8b, that is, the "legs" can also be processed into such positioning bolts (Fig. 2, Fig. d).

After the extrusion is completed, the head 2 of the positioning bolt can be further processed according to requirements, and the free end of the spiral body can be further processed into a tip. All processing steps can be completed on a multi-stage extrusion device, which is very economical.

It is also possible to manufacture an element having three or four screw shafts by the manufacturing method of the present invention.

1. . . element

2. . . Countersunk structure

3. . . casing

7,7’. . . Embryo

8. . . Shaft portion

10. . . Dental mold

11. . . Dental plate

12. . . Guide mode

13. . . shower

F. . . Center of gravity

M. . . Midline

Z. . . Offset direction

Claims (25)

A method of manufacturing a metal member having a shaft, the shaft forming at least one spiral along a longitudinal axis thereof, wherein a blank member (7, 7') is a solid, a sleeve or a combination of a solid and a sleeve, firstly, The blank (7, 7') is placed in a guiding device (12) and then introduced into at least one multi-piece dental mold (10) for cold forging, the dental mold (10) having at least two active The dental plate (11), the inner wall of the dental plate (11) has a bottom mold having a spiral profile (11a), and a punch (13) abuts the free end of the top piece (7, 7') through the cymbal The output of the dental mold (10) is cold forged the shaft (8) of the blank, and the center of gravity (F) of the output is relative to the central mold (10) of the dental mold (10) or the element (1) The offset direction (Z) extends to shape the shaft (8) of the blank (7, 7') into at least one stable auger body (3, 4). The method of claim 1, wherein the output port (15) of the dentition mold (10) is different from the opening (12a) of the guide device (12). The method according to claim 1 or 2, characterized in that two or a plurality of parallel spiral rods (3, 4) can be simultaneously cold-forged, and the spiral rod bodies (3, 4) are intertwined with each other. The method according to claim 1, characterized in that a core rod (14) is passed through and fixed in the center of the opening (15) of the cavities (10), and the spiral rod body is cold forged (3, 4). After surrounding the mandrel (14), after the cold forging process is completed, the mandrel (14) is taken out and the carious mold (10) is opened for demolding. The method of claim 4, wherein the center of the blank (7) forms a first straight rod body and at least one second rod body (3, 4) along a longitudinal central axis thereof, wherein the second rod body The longitudinal center axis of (3, 4) is offset from the longitudinal center axis of the first rod to form a single helix, and the screw body is wound around the first rod during the stamping process. The method of claim 1, wherein when the blank member is a sleeve (6), the mandrel (14) passes through the top end of the sleeve (6) and protrudes from the sleeve (6). The bottom end of the head (13) is formed as a sleeve that fits over the mandrel (14) during extrusion. The method of claim 1, characterized in that the blank member (7') is previously formed into a blank member (7') having a shaft portion (8), wherein the shaft portion is made of one or several The root body is longitudinally extended (8a, 8b). The method of claim 1 wherein all of the extrusion process is completed in a multi-stage extrusion apparatus from the cutting of the rod body or the wire to the extrusion process. The method of claim 1, wherein the free ends of the shaft or the spiral form a tip shape. The method of claim 1, wherein the blank is heated prior to cold forging. The method of claim 3, wherein the total outer diameter of the one or more rods formed into the spiral is greater than or equal to the outer diameter of the blank or the head. The method of claim 1, wherein the spiral has a different torque or a threaded angle. The method of claim 3, wherein the two or more helical rods (3, 4) are cold forged through a dental mold (10), and the dental mold (10) has two or A plurality of openings that are offset from the axis of the blank (7, 7'). The method of claim 3, characterized in that after the cold forging is completed, the component (1) is forged to reduce the thread of the screw body (3, 4). a device for carrying out the above method, the device comprising at least one multi-piece caulking mold (10), a guiding device (12) and a punch (13), wherein the cavities (10) have at least two The movable tooth plate (11) has an inner wall having a bottom mold having a spiral contour, and a blank member (7, 7') is placed in the guiding device (12), and the punch (13) is pressed Applying a pressure to the blank member (7, 7') in a direction, and the center of gravity of the output port of the tooth decay mold (10) is offset from the line of the tooth decay mold (10) or the element (1) The direction of movement (Z) extends. The device of claim 15, wherein the opening of the dent shell (10) has a different cross section than the opening (12a) of the guide (12). The device of claim 15 or 16, further comprising a fixed mandrel (14) disposed at a center of the output of the dent shell (10) and extending into the center The output port (15). A device according to claim 15, characterized in that the guiding means for accommodating the blank (7, 7') is part of the dental mold (10) or is a guiding die (12). The device of claim 17, wherein the mandrel (14) extends into the guide or the guide die (12). The device of claim 15 is characterized in that the bottom end of the punch (13) is sleeved on the mandrel (14). A device according to claim 15, characterized in that the dent shell (10), the guide die (12), the punch (13) and the mandrel (14) are cold forging units of a multi-stage extrusion apparatus. The device of claim 15, wherein the device has a plurality of dentition molds, wherein a center of gravity of the output port (15) of a dent tooth mold is offset with respect to the dentition mold or the line of the element The direction of movement (Z) extends. The device of claim 15, wherein the device further comprises a dental mold (10), wherein the central output port (15) is divided into a plurality of output ports by a central insert, and one of the output ports The center of gravity extends in the offset direction (Z) relative to the dentition mold or the line in the element (1). The device of claim 23, wherein the central insert is part of a mandrel (14). The device of claim 15 wherein the device further has a central mold opening through which a straight rod body can be formed.