High production rate swaging machine and swaging working process

Abstract

 The present invention is provided for allowing a metal stock (7) to be worked by cold working such as swaging, at a higher production rate and with a higher working productivity. A metal stock (7) may be processed by increasing its density, by refining its crystalline grain structure, and by eliminating any deformation that might occur locally and unevenly due to its metal plasticity.
A swaging machine (1) is capable of running at a higher production rate and with a higher working productivity, and includes a series of several sets of swaging die sets (6) arranged in a tandem along the length of a metal stock (7) being worked, wherein any two adjacent swaging die sets (6) are placed in close proximity to each other, and may be actuated at a different timing with regard to each other so that the following one of the any two adjacent swaging die sets (6) can apply a counter pressure to the metal stock (7) from the side located at a right angle to the side on which the metal stock (7) becomes deformed by flowing toward a relief in the preceding one of the any two adjacent swaging die sets (6).
A swaging process or method is performed continously at a higher production rate by using a series of several sets of swaging dies (6) arranged in a tandem along the length of a metal stock (7) being worked, wherein any two adjacent swaging die sets (6) are placed in close proximity to each other, and may be actuated at a different timing with regard to each other so that the following one of the any two adjacent swaging die sets (6) can apply pressure to the metal stock (7) in a counter direction from the side opposite the side on which the metal stock (7) becomes deformed by flowing toward a relief in the preceding one of the any two adjacent swaging die sets (6).

Description

[0001] The present invention relates generally to the art of metal working, and more particularly to a swaging machine that is capable of running at a high production rate and with a high metal working productivity. The present invention also provides a swaging working method that may be performed in a continuous manner and at a high production rate. In accordance with the swaging machine and method, final products may be obtained by increasing the density for a metal wire stock consisting of individual twisted wires, by refining the crystalline grain structure, by eliminating any deformation that might occur locally and unevenly in a particular direction, and by facilitating the metal working process.

[0002] There is a conventional swaging machine that includes a series of multi-stage swaging dies that apply pressure to a metal stock being worked in a radial direction, such as metal wire stock, metal tube stock, etc. (referred to collectively as "metal stock").

[0003] When a metal stock is processed through the conventional arrangement of swaging die sets, the metal stock may be elongated in a longitudinal direction while becoming deformed in a transverse direction in which the metal stock tends to flow toward a relief in each of the die sets. For practical uses, there are limitations on the number of impacts to be applied by the swaging dies, as well as on the number of rotations to be driven when points of impact by the swaging dies change. For this reason, it is impossible to achieve the high production rate. If an attempt is made to increase the production rate, the metal stock being worked may excessively fill the elliptical relief in the dies, which may produce fins. Or the metal stock entering the swaging dies under applied pressure may totally be swung by the increasing rotating torque produced in the swaging dies. Thus, the low production rate must be tolerated. It is particularly noted that the prior art swaging machine and method has a further disadvantage in that, when all of the swaging die sets arranged in the tandem are operated simultaneously, a metal stock may not be fed smoothly through the tandem swaging die arrangement, and so the smooth metal working cannot be achieved.

[0004] For example, a solid metal wire stock is usually worked at the rate of 20 mm to 30 mm per second, and a metal tube stock is usually worked at the rate of 30 mm to 60 mm per second. Other metal stocks must be worked (such as drawn or rolled) at the low production rate, which corresponds to 1/10 to 1/20 of the above production rate.

[0005] Despite its low production rate, the swaging process generally has a number of advantages. For example, cold or hot working may be carried on, depending upon the type of metals being worked, and metals of foreign shapes in cross section, such as triangle, square, and the like, may be produced by the swaging process. Therefore, the swaging process may be utilized for processing various types of metals.

[0006] The present invention eliminates the problems of the prior art swaging machine as described above, by arranging a series of several sets of swaging dies in a tandem in such a way that any two adjacent sets are placed at a particular angle with regard to each other.

[0007] Specifically, one object of the present invention is to provide a swaging machine that is capable of running at a high production rate and with a high working productivity, and includes a series of several sets of swaging dies arranged in a tandem along the length of a metal stock being worked, wherein any two adjacent sets are placed in close proximity to each other and all of the swaging die sets are operated at a different timing with regard to each other. In one preferred embodiment, the swaging machine may include two to six sets of swaging dies arranged in a tandem.

[0008] Another object of the present invention is to provide a swaging working method that may be performed in a continuous manner and at a high production rate by using several sets of swaging dies arranged in a tandem along the length of a metal stock being worked, wherein the method comprises allowing the following one of any two adjacent die sets to be operated at a different timing with regard to each other such that the following one of the two adjacent sets can apply a counter pressure to the metal stock from the side thereof located at a right angle to the side on which the metal may become deformed by flowing toward a relief in the preceding one of the any two adjacent die sets. Advantageously, each adjacent die set may apply the pressure in the counter direction, in such a way that it can slowly control the increasing flow resistance of the metal stock that may become deformed due to its metal plasticity.

[0009] A further object of the present invention is to provide a swaging working method that may be performed in a continuous manner and at a high production rate by using several sets of swaging dies arranged in a tandem along the length of a metal stock being worked, wherein the method comprises allowing the following one of any two adjacent swaging die sets to be operated for applying a counter pressure to the metal stock, from the side located at a right angle to the side on which the metal may become deformed by flowing toward the relief in the preceding one of the any two adjacent swaging die sets, said following one being operated at a different timing with regard to said preceding one at least when the maximum working pressure is applied.

[0010] A still another object of the present invention is to provide a swaging working method that may be performed in a continuous manner and at a high production rate by using several sets of swaging dies arranged in a tandem along the length of a metal stock being worked, wherein the method comprises allowing the following one of any two adjacent swaging die sets to be operated for applying a counter pressure to the metal stock, from the side located at an right angle to the side on which the metal may become deformed by flowing toward a relief in the preceding one of the any two swaging die sets, and wherein one of the swaging die sets is operated for working upon a metal stock, while all of the other swaging die sets are non-operational, freeing the metal stock from the irrespective holding pressure,

[0011] For example, consider that a soft steel which has a tensile strength of 30 kgf/mm² is worked by the swaging dies. In this case, if the total of the grooves formed in the swaging dies is equal to more than 30 times the average diameter of all individual soft steel wires, the resistance to the deformation to which the wires would be subjected would amount to five times the tensile strength of 30 kgf/mm², or 150 kgf/mm² (no hardening is assumed in this case). Thus, two-dimensional deformation could not be obtained. However, three-dimensional deformation may be obtained, depending upon the particular shape of the groove to be formed in the swaging dies, and the part of the metal to be deformed may be deformed by placing that part under the pressure applied by a series of swaging die sets arranged in a tandem. In this way, the coefficient of friction may be reduced drastically, and the part of the metal that has been deformed to expand transversely through the preceding stage set may be pressed by the next stage set following that preceding set, thus preventing any fins from being produced from that expanded part.

[0012] In the arrangement including a series of three die sets in a tandem as shown in Fig. 7, for example, reduction may be performed through the first and second die sets, and skin pass may occur at the third die set. The total frictional resistance may be reduced during the swaging process, and a high production rate (such as 300 mm per second or more) may be achieved. In the arrangement including a series of five die sets in a tandem, not shown, reduction may be performed through the first, second, third and fourth die sets, and skin pass may occur at the last (fifth) die set.

[0013] Theoretically, any number of swaging die sets may be included in the tandem arrangement, but practically and preferably, two to six die sets may be included.

[0014] In the present invention, at least any swaging die sets that participate in the reduction are not operated simultaneously. In the tandem arrangement including three swaging die sets, for example, the first and second sets participate in the reduction. So, backers 5, 5 having the shape shown in Fig.14 (a) and Fig.14 (b) may be provided so that the first and second sets are not operated at the same time. Alternatively, those swaging die sets may be arranged at an offset from each other. Also it is possible to provide the backer rollers, each of which has a part having a smaller diameter than the other part as shown in Fig. 7, Fig. 8 and Fig. 9.

[0015] Further, six roller, each of which has an uniform diameter at any part of roller, may be provided, and the swaging die sets that participate in the reduction may be arranged at a right angle with regard to each other as shown in Fig. 15 in order to prevent at least any swaging die sets that participate in the reduction from being operated simultaneously.

[0016] It should be understood that any of the methods that employ the concept of the present invention as described above, that is, that the reduction swaging die sets are not operated simultaneously, falls within the spirit and scope of the present invention.

[0017] Preferably, types of metals that may be handled by the present invention may include those of tungsten, molybdenum, titanium, and the like. Those types of metals may be cold or hot worked by subjecting them to the swaging action. Particularly, the hot working may effectively be performed for a wire rope stock consisting of individual coper twists so that the gap between the individual twists can be minimized, that is, the maximum density may be obtained.

[0018] As it may be appreciated from the foregoing description, the swaging machine according to the present invention includes several sets of swaging dies arranged serially and in a tandem along the length of a metal stock being worked, each adjacent set being placed in close proximity to each other such that any two adjacent sets are positioned at a right angle with regard to each other. According to this tandem arrangement, any two adjacent sets that participate in the reduction may be operated at a different timing with regard to each other so that the following one of the any two adjacent sets can apply a counter pressure to a metal stock being worked, from the side located at a right angle to the side on which it becomes deformed from a true circle in section into an expanded part by flowing toward the relief in the preceding one of the any two adjacent sets. Thus, the expanded part may be pressed and reformed back to the true circle by the following set, and the resistance to the deformation that metal is subjected to may be reduced. Passing sequentially through those die sets, the metal stock may be elongated in proportion to the cross section.

[0019] As compared with the conventional multi-stage swaging machine including several die sets arranged in a tandem in which any two adjacent sets are not positioned at an angle with regard to each other, the swaging machine according to the present invention allows a metal stock to be worked by reducing the resistance to the deformation to which the metal stock is subjected. Thus, the production rate or productivity may be increased. In addition, the metal stock can be fed smoothly by avoiding that all the swaging die sets are operated simultaneously.

[0020] According to the present invention, the resistance to the deformation to which a metal stock is subjected during the swaging action may be reduced, and the high production rate may therefore be achieved. Those effects can be attained by arranging the several sets of swaging dies serially in a tandem and placing any two adjacent sets at an angle with regard to each other, and operating each swaging die set at a different timing with regard to the other swaging die sets. Products can thus be obtained by increasing the density (for a metal wire stock consisting of individual wires, in particular), refining the crystalline grain structure, and eliminating any deformation that may occur locally which would cause any fins to be produced.

[0021] According to the present invention, the relatively high rate reduction (15% or more, for example) can be attained by avoiding that at least any two adjacent die sets or all die sets are actuated simultaneously for applying pressure to a metal stock being worked.

[0022] The above and other objects, features and advantages of the present invention may be understood from the following detailed description of the particular preferred embodiments that will be provided below with reference to the accompanying drawings, in which:

Fig. 1 is a sectional side view showing part of the swaging machine in accordance with a first preferred embodiment;

Fig. 2 is a front view of the swaging machine shown in Fig. 1, with some parts not shown;

Fig. 3 is a sectional side view showing part of the swaging machine in accordance with a second preferred embodiment;

Fig. 4 is a front view of the swaging machine shown in Fig. 3, with some parts not shown;

Fig. 5 is a sectional side view showing part of the swaging machine in accordance with a third preferred embodiment;

Fig. 6 is a front view of the swaging machine shown in Fig. 5, with some parts not shown;

Fig. 7 is a schematic diagram showing a perspective view of a series of three sets of swaging dies arranged in a tandem, on an enlarged scale, with some parts not shown;

Fig. 8 is a schematic diagram showing a side view of the tandem arrangement including three sets of swaging dies and corresponding rollers, with some parts not shown;

Fig. 9 (a) is a sectional view taken along the line A - A in Fig. 8;

Fig. 9 (b) is a sectional view taken along the line B - B in Fig. 8;

Fig. 10 is a perspective view showing the other swaging dies;

Fig. 11 is a schematic diagram showing the section of a metal stock and explaining how it becomes deformed in a particular direction when it is being pressed;

Fig. 12 is a perspective view showing, on an enlarged scale, part of the swaging machine including a series of three set of swaging dies arranged in a tandem with some parts not shown;

Fig. 13 is a schematic diagram showing how the three swaging die sets are placed relative to each other within a die holder;

Fig. 14 (a) shows that the most expanding position of a backer is located at the center;

Fig. 14 (b) shows that the most expanding position of a backer is at an offset of θ relative to the center; and

Fig. 15 is a front view of the other swaging machine of the present invention with some parts not shown.

[0023] Referring to the figures, several preferred embodiments of the present invention are described below.

(Embodiment 1)

[0024] Referring first to Figs. 1, 2, 12, and 13, there is shown a swaging machine according to a first preferred embodiment which is the spindle-driven type.

[0025] A swaging machine, generally designated by numeral 1, includes a housing 2 inside which an annular anti-pressure member 3 is mounted. Inside the annular anti-pressure member 3, there are backer rollers 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h (which are collectively referred to by a single reference numeral 4), which are arranged at equal intervals and mounted rotatably (Fig. 2). The backer rollers 4 are operated to give impact to backers 5a, 5b, 5c, 5d, 5e (which are collectively referred to by a single reference numeral 5), which are then actuated to move a metal stock, such as metal wire stock 7 as shown, toward sets of dies 6a, 6b, 6c, 6d, 6e (which are collectively referred to by a single reference numeral 6) through which the metal wire stock 7 is subjected to the swaging action. The backer rollers 4 are mounted on rings 8, 9 which are arranged at predetermined interval.

[0026] A spindle 11 is mounted across the interior of the housing 2, and is drivably supported at one end thereof on a bearing 10. The outer end of the spindle 11 extending outwardly through the housing 2 carries a pulley 12, which is operatively connected to a pulley 14 on a motor 13 by way of a belt 15. The other or inner end of the spindle 11 located inside the housing 2 is coupled with a die holder 16 (Fig. 13). The die holder 16 has slits formed therein, which are collectively referred to by numeral 17, and each combination of the die 6 and backers 5 is mounted one after another in the corresponding slit 17 slidably in an axial direction.

[0027] The die holder 16 has a first slit 17a, a second slit 17b which is provided at a right angle with regard to the first slit 17a, and a third slit 17c which is provided at a right angle with regard to the second slit 17b. As seen from Fig. 13, those slits are provided in the order of the first slit 17a, second slit 17b and third slit 17c when viewed from the direction in which a metal wire stock 7 is fed toward the spindle 11, as indicated by an arrow 36 in Fig. 1. Each respective combination of the die 6a and backer 5a, the die 6b and backer 5b, and the die 6c and backer 5c is mounted in each respective corresponding slit 17a, 17b, and 17c (Fig. 1, Fig. 12 and Fig. 13).

[0028] In operation, the swaging machine 1 may be run by starting the motor 13. When the motor 13 is started, the spindle 11 is rotated in the direction of an arrow 18 by way of the pulley 14, belt 15 and pulley 12 (Fig. 2) Then, the backer rollers 4a, 4e are actuated to press the first set of dies 6a, 6a and the third set of dies 6c, 6c, and the backer rollers 4c, 4g are actuated to press the second set of dies 6b, 6b. Thus, when the metal wire stock 7 is fed through the swaging machine 1, it is first placed under the pressure applied by the first set of dies 6a, 6a so that it is deformed to have an expanded portion, and is then placed under the pressure applied by the second set of dies 6b, 6b where the expanded portion is pressed and removed while it is deformed to have a second expanded portion. It is then placed under the pressure applied by the third set of dies 6c, 6c where the second expanded portion is then pressed and removed. Finally, the metal wire stock 7 is reformed to a wire product 7a having a true circle in cross section (Fig. 1).

[0029] For the three-stage swaging die arrangement described above, reduction may occur through the first and second sets of dies, while for the five-stage swaging die arrangement, reduction may occur through the first through fourth sets of dies. When the metal wire stock passes through the first set of dies, it may be pressed and deformed transversely to include an expanded portion, and the resistance to the deformation to which the metal is subjected may become relatively small. Passing through the second set of dies, the expanded portion is pressed and removed, and the resistance to the deformation to which the metal is subjected may also become relatively small. Finally, skin pass may occur through the third set of dies, and the resistance to the deformation to which the metal is subjected may become relatively small. The resulting total resistance may thus be reduced, and the higher production rate may be achieved accordingly. In short, metal may be deformed easily by causing the first set of dies to press it in the direction of an arrow 25a (Fig. 11) so as to be deformed in the direction of an arrow 26a so that it can have an expanded portion, and then by causing the second set of dies to press the expanded portion in the direction of an arrow 29 so as to be deformed and removed.

[0030] In the description above, it should be noted that each swaging die set is operated at a different timing with regard to the other swaging die sets. The swaging die sets are not operated simultaneously except that at least the skin pass occurs.

(Embodiment 2)

[0031] Referring next to Figs. 3 and 4, a second preferred embodiment is described.

[0032] In the preceding (first) embodiment the spindle 11 is driven for rotation. In the second embodiment, there is an annular anti-pressure member 19 which has a Vee groove 20 on the outer wall, which acts as a Vee pulley 21 which is operatively connected to a Vee pulley 23 on a motor 22 by way of a Vee belt 24. An upper machine frame 25 is mounted on a machine pedestal 26, and mounting bolts are shown by 27, 27.

[0033] The backer rollers 4, the backers 5 and the die sets 6 in the current embodiment are identical to those in the preceding embodiment, both functionally and constructionally. For simplicity, the description of them is omitted.

[0034] In operation, when the motor 22 is started, it causes the Vee pulley 21 to rotate, moving the backer rollers 4 around in the direction of an arrow 28 (Fig 4). Those backer rollers 4 act upon the corresponding backers 5 sequentially so that the former can press the latter. Any two adjacent die sets are always kept at a particular angle with regard to each other, and the resistance to the deformation to which the metal stock is subjected may be reduced as described above in the preceding embodiment.

[0035] The swaging die arrangement described here is primarily intended for working a metal wire rope stock consisting of individual wires, in order to increase the density between the wires can be increased. In this case, the total length of the die sets in series (total slit length) may be greater than the diameter of a particular metal wire stock. For example, the length may be 20 to 30 times the diameter of the metal wire stock. In this arrangement, the diameter of the metal wire stock may be reduced with its length remaining unchanged. Fins that might occur due to the deformation can be avoided. Thus, the current embodiment provides the increased production rate.

[0036] In the current embodiment, as same as the preceding embodiment, each swaging die set is operated at a different timing with regard to the other swaging die sets. The swaging die sets are not operated simultaneously except that at least the skin pass occurs.

(Embodiment 3)

[0037] A third preferred embodiment is described by referring to Figs. 5 and 6.

[0038] In this embodiment, there is an annular anti-pressure member 19 which has a Vee groove 20 on the outer side, which acts as a Vee pulley 21 which is operatively connected to a Vee pulley 23 on a motor 22 by way of a Vee belt 24. The anti-pressure member 19 may be rotated by those elements. A spindle 11 has a Vee pulley 12 fixed to the outer end thereof, which is operatively connected to a Vee pulley 14 on a motor 13 by way of a Vee belt 15. A one-way clutch 38 may be operated to engage and disengage the spindle 11. To the inner end of the spindle 11 is connected a die holder 16. The anti-pressure member 19 may be rotated in the same manner as in the second embodiment, and the spindle 11 may be rotated in the same manner as in the first embodiment. Specifically, the anti-pressure member 19 may be rotated in the direction of an arrow 32, and the spindle 11 may be rotated in the direction of an arrow 31, as shown in Fig. 6.

[0039] According to the current embodiment, the anti-pressure member 19 and the spindle 11 may be rotated by engaging the one-way clutch 38.

[0040] For a metal wire stock having a small cross section and consisting of thin wires of 2 mm to 6 mm φ in diameter, for example, to be worked, the torque developed during the swaging action will be transmitted to the metal wire stock being worked. Each individual thin wire may exhibit the elasticity like a spring that resists the torsion brought about by the torque. The moment that the torque during the swaging action is placed under no load until the next impact is applied, the torsion resisted by the wire will be restored.

[0041] For a thick wire stock (or a rod) to be worked, the spindle must be rotated at a low speed, as opposed to the thin wire stock.

[0042] In the current embodiment, as same as the preceding embodiments, each swaging die set is operated at a different timing with regard to the other swaging die sets. The swaging die sets are not operated simultaneously except that at least the skin pass occurs.

(Embodiment 4)

[0043] Referring to Figs. 7, 8, 9 and 10, a fourth embodiment is described.

[0044] The embodiment has two possible variations. Fig. 7 shows the three stage tandem arrangement including each combination of dies 6a, 6b and 6c and corresponding backers 5a, 5b and 5c, in which any two adjacent combinations are placed at a right angle with regard to each other.

[0045] In the embodiment shown in Fig. 7 including the three sets of dies arranged in a tandem, the first set of dies 6a, 6a is placed at an angle of 90° with regard to the second set of dies 6b, 6b which in turn is placed at an angle of 90° with regard to the third set of dies 6c, 6c which is placed at the same angle as the first set (that is, the first and third sets have the same orientation). In this arrangement, the set following its preceding set may apply a counter pressure to the metal stock from the side located at a right angle to the side on which the metal becomes deformed by flowing toward a relief in the preceding set.

[0046] If the five stage tandem arrangement including each combination of dies 6a, 6b, 6c, 6d and 6e and corresponding backers 5a, 5b, 5c, 5d and 5e, in which any two adjacent combinations are placed at a right angle with regard to each other, is adopted, not shown, the third set of dies 6c, 6c is placed at an angle of 90° with regard to the fourth set of dies 6d, 6d which in turn is placed at an angle of 90° with regard to the fifth set of dies 6e, 6e. As a result, the die sets 6a, 6c and 6e have the same angle, and the die sets 6b and 6d have the same angle (that is, they have the same orientation, respectively).

[0047] Fig. 10 shows the die arrangement in which dies 30a, 30b, 30c are arranged radially and at an angle of 120° with regard to each other.

[0048] Fig. 12 shows the variation of the three stage die arrangement, in which a spindle 11 is supported by a roller bearing 33, and die holders which are collectively referred to by numeral 16 are coupled together by through bolts 34, 34. The spindle 11 carries a Vee pulley 37 around which a Vee belt 35 is threaded. Fig. 13 shows how the individual die holders 16a, 16b and 16c are positioned in relation to each other.

[0049] In the current embodiment, as same as the preceding embodiments, each sawing die set is operated at a different timing with regard to the other swaging die sets. The swaging die sets are not operated simultaneously except that at least the skin pass occurs.

(Embodiment 5)

[0050] In the present embodiment, the mechanisms to operate each swaging die set at a different timing with regard to the other swaging die sets which can be adopted in the preceding four embodiments are described.

[0051] The die sets may be actuated at a different timing with regard to each other, by varying the shape of the surface on which each of the backers 5 engages the corresponding one of the backer rollers 4 and thereby allowing the backer rollers to be actuated at different times. As shown in Fig. 14 (a) and Fig. 14 (b), the die sets may be actuated at different times by providing the maximum expanded portions 36 and 36a on any two adjacent backers 3, 5 at an angle of θ. Alternatively, the die sets may be actuated at different times by shifting the position of each backer roller in relation to each corresponding backer. It is also possible that the swaging die sets are not operated simultaneously by providing the backer rollers, each of which includes a particular part having a small diameter than the other part, as shown in Fig. 7, Fig. 8 and Fig. 9. As shown from Figs. 7, 8 and 9, when the first die set 6a, 6a is actuated according to the pressing by backer rollers 4a and 4d, the second die set 6b, 6b and the third die set 6c, 6c are not actuated. The second die set 6b, 6b is not pressed as shown in Fig. 9 (a). The third die set 6c, 6c is not pressed, since the parts of backer rollers 4a and 4d corresponding to the third die set 6c, 6c have a small diameter as shown in Fig. 7 and Fig. 9 (b). In this case, six backer rollers are required, but this requirements may be reduced by varying the shape of the backer that contacts the corresponding backer roller as shown in Fig. 14 (a) and Fig. 14 (b). Further, it is possible that the swaging die sets are not operated simultaneously by providing six rollers 4, each of which has an uniform diameter along the length of each roller, and providing the swaging die sets 6, that participate in the reduction, at right angle with regard to each die set as shown in Fig. 15.

[0052] It should be apparent to those skilled in the art that any two adjacent die sets or all die sets may be actuated at different times, not simultaneously, by any other means than by providing the different maximum expanded portions on the backer rollers 5 or by shifting the positions of the backer rollers with regard to the corresponding backers, which may fall within the scope of the present invention.

[0053] If it is required, the before described four embodiments may be changed to actuate any two adjacent die sets at the same time for applying pressure using backer rollers, which has conventional known structure and shape. Even if any two adjacent die sets are at the same timing, the resistance to the deformation to which a metal stock is subjected during the swaging action may be reduced, and the high production rate may therefore be achieved as compared with the conventional multi-stage swaging machine including several die sets arranged in a tandem, since, in the present invention, any two adjacent sets are positioned at an angle with regard to each other.

[0054] But there is a disadvantage that, when all of the swaging die sets arranged in tandem are operated simultaneously, a metal stock may not be fed smoothly through the tandem swaging die arrangement, and so the smooth metal working can not be achieved. Especially, if the high rate reduction (10% or more, for example) is required, the smooth working can not be accomplished by said swaging machine in which all of the swaging die sets arranged in tandem are operated simultaneously.

[0055] On the contrary, according to the present invention, at least any two adjacent die sets or all of the die sets are not actuated simultaneously but rather are actuated at different timing, it is possible to achieve the high reduction rate which is substantially equal to 30%.

[0056] Although the present invention has so far been described with reference to the particular preferred embodiments thereof, it should be understood that various changes and modifications may be made within the spirit and scope of the invention as defined in the appended claim.

Claims

1. A swaging machine comprising
   a series of several sets of swaging die means arranged in a tandem along the length of a metal stock being worked, each adjacent set being placed in close proximity to each preceding set and all of the sets of swaging die means arranged in a tandem being operated at a different timing with regard to each other for working upon the metal stock.

2. The swaging machine as defined in Claim 1, wherein swaging die means includes two to six sets of swaging dies arranged serially in a tandem.

3. A method of working a metal stock that may be performed in a continuous manner by using a series of several sets of swaging dies arranged in a tandem along the length of the metal stock being worked, wherein:
   any two adjacent sets of swaging dies are operated at a different timing with regard to each other such that the following one of the two adjacent sets can apply a counter pressure to the metal stock from the side located at a right angle to the side on which the metal stock becomes deformed by flowing toward a relief in the preceding one of the two adjacent sets.

4. The method as defined in Claim 3, wherein each adjacent set is actuated for applying pressure in such a manner as to slowly control the increase in resistance that may occur due to the metal plasticity of a metal when it becomes deformed by flowing.

5. A method of working a metal stock that may be performed in a continuous manner by using a series of several sets of swaging dies arranged in a tandem along the length of the metal stock being worked, wherein:
   any two adjacent sets of swaging dies are operated such that the following one of the two adjacent sets can apply a counter pressure to the metal stock from the side located at a right angle to the side on which the metal stock becomes deformed by flowing toward a relief in the preceding one of the adjacent sets, and wherein at least the reduction is performed by any two adjacent sets at a different timing with regard to each other.

6. A method of working a metal stock that may be performed in a continuous manner and at a high production rate by using a series of several sets of swaging dies arranged in a tandem along the length of the metal stock being worked, wherein:
   any two adjacent sets of swaging dies art operated such that the following one of the two adjacent sets can apply a counter pressure to the metal stock from the side located at a right angle to the side on which the metal stock becomes deformed by flowing toward a relief in the preceding one of the adjacent sets, and wherein one set of swaging dies is operated for working upon the metal stock, while all of the other sets of swaging dies are non-operational, freeing the metal stock from their respective holding pressure.

Drawing