GB2309001A - Methods for use with punching press machines - Google Patents

Description

2309001 "METHODS FOR USE WITH PUNCHING PRESS MACHINES" The present

invention relates to a method for controlling a punching press machine and a method for working a work by means of the punching press machine. In the me thods, a punching press machine is provided with a tool in the form of wheels (hereinafter referred to an working wheels), each of which is rotatably mounted on a shaft parallel to a work in the form of a plate (hereinafter referred to simply as work). as upper and lower working wheels of the punching press machine. and the work is placed between the upper and lower working wheels, and the work and the upper and lower working wheels are relatively moved with the upper working wheel pressed against the work by a punch head to plastically deform the work, thereby carrying out working of the work such as continuous cutting, cutting out a wdrk piece, continuous drawing, or marking.

A known punching press machine is generally provided with a conventional punch and die as an upper tool member and a lower tool member into which the upper tool member is pressed, respectively. A work in the form of a plate is placed between the punch and die as upper and lower tool members, and the punch as an upper tool member is repeatedly struck by a punch head at intervals to punch the work, thereby carrying out working such as punching or drawing.

Accordingly, in such working, the work is moved repeatedly at intervals to position a portion to be worked under the upper tool - 1 mr irrespective of types of the working such as cutting and drawing. In other words, the working is carried out only in a repeated manner and cannot be carried out continuously.

Accordingly, when working such as cutting or drawing is carried out on a work by means of a conventional punching press machine using a customary punch and die along a line, the resulting cut line, drawn line or marking is a chain of repeated segments of a shape of the punch. In view of this, such working is unsuitable for a case where press working is required to provide a smooth worked line, and even if used in such a case, postworking is required.

In contrast to the working by means of a conventional punching press machine, when working is performed using working wheels each of which is mounted on a shaf t parallel to a work as upper and lower tool members, it is possible to carry out cutting, drawing or the like continuously. Therefom the above problem is not caused so long as the working is carried out along a straight working line. However, in continuous working along a curved or angulated working line, problems inherent in working by means of working wheels etLn be cau. For example, a cut edge of a work is bent upwardly or downwardly along a cut line, and a contour of the work is not bold at the initial end of the working.

In a punching press machine provided with a conventional punch and die as well as working wheels, when working is performed by means of the punch and die, a work is moved relative to the tool by point-to-point control, and when working is performed by means of the working wheels, the work is positioned by contouring control.

Heretofore, however, such a punching press machine provided with a conventional punch and die as well as working wheels has not been developed. It follows that there has not been a method for controlling such a punching press machine.

In view of the above problems, it is an object of the present invention to provide a method for controlling a punching press machine provided with a conventional punch and die an well as working wheels, and a method for working by means of the punching press machine, which is capable of solving the problems inherent in working by means of working wheels, and a method for working to cut out a work piece from a parent work. in particular, f rom a parent work in the form of a plate.

The present invention has been made with a view to solving the abovementioned problems. According to the present invention, there in provided a method for controlling a punching press machine provided with working wheels an well as a conventional punch and die to carry out working such as cutting or drawing, said method comprising:

establishing correspondences between the conventional punch and die and point-to-point control and between the working wheels and cohtouring control in a control unit having point-to-point control function for control to repeatedly move a work at intervals taking shortest course to successively place a plurality of portions to be worked under the punch to thereby carry out working such an cutting out successively and contouring contort function for control to move the work along a working course of a straight or curved line, or a working course including straight and curved lines to thereby carry out working such as cutting or shaping continuously, and selecting the corresponding control when working such as cutting or shaping is carried out using the punch and die or the working wheels, thereby carrying out working along an intended course of a work.

According to another aspect of the present invention, there is provided a method for working by means of a punching press machine using working wheels as upper and lower tool members each of which is rotatably supported by a shaft parallel or substantially parallel to a work, said punching press machine having a punch head capable of being kept at an intended position in its stroke for pressing the upper working wheel against the work placed between the upper and lower working wheels to plastically deform the work, said method comprising:

selecting direction of the upper and lower working wheels relative to direction of progress of the cutting as standard direction or reverse direction by turning each of holders of the working wheels in an angular amount of 180 degrees.

In this method for working, according to still another aspect, each of the shafts of the working wheels is slightly slanted to provide each of the shaft with an offset angle relative to the surface of the 'work, and the direction of the working wheels is defined as the standard direction when the cutting is advanced while looking the inclination of the working wheels to the right relative to the direction of progress of the cutting.

According to a further aspect, an upper working wheel in moved at a final end of a working line of working in the normal direction relative to the working line of a work in a slight amount and then in the direction of progress of the working in a slight amount and then lif ted up.

According to a still further aspect of the present invention, there is provided a method for working by means of a punching press 4 machine using working wheels as upper and lower tool members along a working line including its portions via an angulation, said method comprising:

raising a punch head at the angulation, which is pressing the upper working wheel against a work to such a level that the upper working wheel is brought out of contact with the work, turning each of holders of the upper and lower working wheels to the direction of the next portion of the working line to adjust the direction of the upper and lower working wheels to the direction of the next portion, and lowering the punch head to the level for the working to resume the working.

In addition, according to another aspect of the present invention, there is provided a method for working by means of a punching press machine using working wheels as upper and lower tool members along a continuous curved working line including a straight portion, said method comprising:

turning each of holders of the upper and lower working wheels to adjust the working wheels to the tangential direction relative to the working line, and concurrently with this, adjusting the level of the upper working wheel by controlling a punch head to continuously carry out the working along the continuous curved working line.

Further, according to still another aspect of the present invention, a method for cutting out an intended work piece from a parent work in the form of a plate by means of a punching press machine using working wheels, said method comprising:

retaining a cutout work or cutout work-to-be raised from a parent work by cutting in the parent work by appropriate several sites, and afterward.

punching out the cutout work or cutout work-to-be by punching.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a sectional view of an example of working wheels used in the present invention, which frontally shows an example of cutting of a work in the form of a plate by means of the working wheels.

Fig. 2 is a perspective view showing an offset angle and standard and reverse directions of working.

Fig. 3 is a plan view of an example of a working line of working by means of working wheels.

Fig. 4 is a plan view of an example of a working line of drawing by means of working wheels.

Fig. 5 is a sectional view of the result of the drawing in Fig.

4.

Fig. 6 is a plan view of an example of cutting by means of working wheels in the standard direction.

Fig. 7 is t sectional view of the result of the cutting in Fig.

6.

Fig. 8 is a plan view of another example of cutting by means of working wheels in the reverse direction.

Fig. 9 is a sectional view of the result of the cutting in Fig.

Fig. 10 is a front view showing cutting a work in the form of a plate by means of working wheels.

Fig. 11 is a plan view of one mode of the cutting in Fig. 10.

Fig. 12 is a plan view of another mode of the cutting in Fig. 10.

Fig. 13 is a plan view of an example of motion of a working - 6 wheel at an end of working.

Fig. 14 is an enlarged sectional view of the'cutting Fig. 10.

Fig. 15 is a plan view showing an example of movement of working wheels in working by means of the working wheels.

Fig. 16 is a plan view showing another example of movement of working wheels in working by mans of the working wheels.

Fig. 17 is a plan view showing still another example of movement of working wheels in working by means of the working wheels.

Fig.18 is a diagram showing relationship between movement of a work and movement of a punch head in nibbling by means of a punching press machine using a conventional punch and die.

Fig. 19 is a plan view showing a cut line in the nibbling by means of a conventional punch and die in Fig. 18.

Fig.20 is a diagram showing relationship between movement of a work and movement of a punch head in nibbling by means of working wheels.

Fig. 21 is a plan view showing a cut line in the nibbling by means of working wheels in Fig. 20.

Fig. 22 id a diagram showing an example of relationship between movement of a work and movement of a punch head in working by means of working wheels. In the movement of the punch head, an interpolative function is incorporated.

Fig.23 is a plan view showing a cut line in the working by means of working wheels in Fig. 22.

Fig-24 is a plan view of a complex curved working line of working by means of working wheels.

Fig. 25 is a plan view of a working wheel holder used for performing the working along the working line in Fig. 24.

Fig.26 is a diagram showing relationship between vertical movement of a punch head and movement of a work in carrying out working by means of working wheels which comprises a plurality of working steps.

Fig. 27 is a diagrammatic view showing locus of vertical movement of an upper working wheel relative to a work.

Fig. 28 in a diagrammatic view showing locus of vertical movement of an upper working wheel relative to a work.

Fig. 29 is a systematic block diagram showing an example of a control unit used in the working method according to the present invention.

Fig. 30 is a block diagram showing an example of a system for controlling the movement of the working wheels as shown in Fig. 13.

Fig. 31 is a flow chart of an example of the control by the system in Fig. 30.

Fig. 32 is a block diagram showing an example of a system for controlling the movement of the working wheels an shown in Figs. 15-1 7.

Fig. 33 is a flow chart of an example of the control by the system in Fig. 32.' In Figs. 1 and 2, reference number 1 represents an upper working wheel comprising a circular blade 2 and a circular stopper 3 having a diameter smaller than that of the blade 2. The blade 2 and the stopper 3 are coaxially mounted on a shaft 4 in contact with each other. The upper working wheel 1 mounted on the shaft 4 is rotatably supported by a stripper 5, which also serves as an upper working wheel casing, with its peripheral edge slightly protruded from the bottom of the stripper 5.

Reference number 6 represents a lower working wheel 8 comprising a blade 7 and a stopper 8 which are counter parts of the blade 2 and the stopper 3 of the upper working wheel 1. The blade 7 and stopper 8 are coaxially mounted on a shaft 9. The lower working wheel 6 mounted on the shaft 9 is rotatably supported by a stripper 10, which also serves as a lower working wheel casing, with its peripheral edge slightly protruded from the top of the stripper 10.

A work 11 is placed between the blade/stopper 2,3 of the upper working wheel 1 and the blade/stopper 7, 8 of the lower working wheel 6, and then forward or backward moved with the cutter wheels being rotated to subject the work 11 to plastic deformation, specifically, cutting or drawing in the direction of the rotation of the cutter wheels.

The upper and lower working wheels 1, 6 are supported by an upper tool member holder H (not shown in Figs. 1 and 2. see Fig. 25) which is vertically movable and a lower tool member holder (not shown) which is vertically unmovable, respectively, as in a case of a tool of a conventional punching press machine. The upper tool member holder can be kept at any vertical position by a punch head (not shown) which is vertically movable by an actuator such as a cylinder. When the upper tool member holder H is pushed down toward the lower working wheel 6 and kept at a predetermined vertical position by the punch head taking the thickness of the work 11 into account, the work 11 is moved in the direction of the rotation of the blades 2, 3 and the stoppers 7, 8. The work 11 in thereby plastically deformed.

If the upper and lower working wheels 1, 6 are cutter wheels, these wheels can have rotational directivity. When all of the blades 2, 3 and the stoppers 7, 8 are held upright as shown in Fig. 1, the upper and lower cutter wheels 1, 6 have no rotational m 9 - directivity. In other words, substantially the same cut edge condition results from working in either of standard and reverse rotational directions. However, when the shafts 4, 9 are slanted relative to a horizontal plane (or the plane of the work) at an offset angle of a few to several degrees and the blades 2, 3 and the stoppers 7, 8 are consequently inclined relative to a perpendicular at an inclination angle of a few to several degrees as shown in Fig. 2, the upper and lower cutter wheels 1, 6 have rotational directivity.

The result of the cutting is different in cut edge depending upon rotational directions of the blades 2, 3 and the stoppers 7, 8. Explanation on this is given with reference to Figs. 3 to 9.

When working is carried out along a working line comprising a straight portion and a curved portion as shown in Fig. 3 or a rectangular working line as shown in Fig. 4 with the blades 2, 3 and the stoppers 7, 8 uninclined or upright as shown in Fig. 1, substantially the same cut edge condition results from the working in either of standard and reverse rotational directions. In Figs. 3 and 4, A represents a working line, B represents rotational direction of theblade and stopper 2, 3 of the upper cutter wheel 11 and C represents a direction of progress of the worki ng. Fig. 5 shows a section of the work subjected to the working in Fig. 4.

On the other hand, when the cutter wheels 1. 6 are inclined with their blades 2, 3 and stoppers 7, 8 provided with an offset angle as illustrated in Fig. 2. the blades 2, 3 and the stoppers 7, 8 have rotational directivity. In other words, if a rotational direction where working is advanced forward while looking the inclination of the blades and stoppers to the right is defined as a standard rotational direction, working with the standard rotational direction is different from working with the reverse 1 0 rotational direction (where working is advanced forward while looking the inclination of the upper cutter wheel 1 to the left) in whether a bend b at a cut edge is formed on a cutout work W1 or on the rest W2 of the work 11. Accordingly, the direction of the movement of the work 11 relative to the cutter wheels 1. 6 is determined depending upon which of the cutout work and the rest is used after the cutting.

When cutting is carried out where a parent work W is placed between upper and lower cutter wheels 1, 6 uninclined as shown in Fig. 10 and the parent work W is then moved forward or backward with the upper cutter wheel 1 pressed against the parent work W to perform cutting by means of upper and lower blades 2, 7 and stoppers 3, 8, the following features are observed. The resulting cutout work CW and the parent work W respectively on the left and the right of the upper and lower cutter wheels 1, 6 are shorn and thereby brought vertically different levels as shown in Fig. 10. The contour of the cutout work CW substantially conforms to the shape of the resulting blank in the parent work W.

In general, the operation of the machine is suspended subsequently to the cutting to remove the cutout work CW, and resumed after the removal of the cutout work M This is undesirable in terms of operational efficiency. Accordingly, if the'cutting of the parent work W by means of the cutter wheels 1, 6 can be continued with the cutout work CW retained in the parent work by utilizing the above-mentioned feature that the contour of the cutout work CW and the outline of the blank of the parent work W substantially conform to each other, the suspension of the cutting operation of the punching press machine for the removal of the cutout work CW, which is usually practiced in a conventional punching press machine, can - 11 oe omitted. This remarkably increases operational efficiency.

In the present invention, a cutout work-to-be CW is raised from a parent work W by cutting in such a manner that it is retained in the parent work W by appropriate several sites, and afterward, the sites are punched. Specifically, cutting is performed along an outline of a cutout work CW to be cut out from a parent work W by means of cutter wheels 1, 6 with corners llrlls of the outline left uncut to retain the cutout work-to-be CW in the parent work W, and afterward. the cutout-to-be CW is punched at the corners llrlls left uncut are punched by means of a conventional punch and die (not shown), as shown in Fig. 11. Alternatively, cutting is performed in the same manner as in the above to retain the cutout work-to-be CR in the parent work W, and afterward, the parent work W is punched at the corners llrlls, as shown in Fig. 12.

Further, a work CW may be cut out from a parent work W. In this case, the cleavage resulting from the cutting is half-punched by means of a conventional punch and die to fit and retain the cutout work CR in the parent work W.

Accordin41 to the above-described cutting procedures, a cutout work or cutout work-to-be CW can be retained in a parent work W, and therefore, cutting operation can be continued without suspending operation of a machine for removal of the cutout work M By virtue of this, operational efficiency is remarkably increased.

Practically, it is preferred that number of steps in the cutting procedure which are subsequent to the step of the punching the corners llrlls left uncut be minimized, that when the corners llrlls lef t uncut are punched by a conventional punch and die, a small punch and die be used to reduce impact by the punching, and that the corners llrlls be narrowly left uncut to reduce an impression of a 1 2 - stripper plate.

In working operation using cutter wheels 1, 6 as described with reference to Figs. 3 to 9 whose blades 2, 7 and stopper 3, 8 are inclined to have an offset angle, if the upper cutter wheel 1 is raised from the final end of the working without taking any measures, an edge of the cleavage in the work 11 is likely to catch on an edge of the upper cutter wheel 1 which is ascending. In consequence, the work 11 is hitched up, and thus it comes off a work clamp or undergoes deformation or damage.

To cope therewith, in the present invention, the work 11 is first moved slightly in the normal direction and then moved slightly in the tangential direction relative to the working line A as shown in Fig. 13, thereby preventing the blade and stopper 2, 3 of the upper cutter wheel 1 from catching the work 11. This will be hereinafter referred to as avoiding motion. Fig. 13 is a plan view schematically showing relative movement between the work 11 and the upper cutter wheel 1. rig. 14 is an enlarged sectional side view showing the relative movement between the work 11 and the blade 2.

In the ptinching press machine employing the cutter wheels 1, 6 described with reference to Fig. 10 as well as the conventional punch and die, the avoiding motion in the working operation by means of the cutter wheels is controlled, for example, by the control system as shown in Figs. 30 and 31. The control system will be described below..

In Fig. 30, reference number 21 represents a tool information input unit for supplying tool information whether a tool used is a conventional punch and die or cutter wheels 1, 6 to an avoiding operation unit 23a in a NC (numerical control) program analysis unit 23, reference number 22 represents an avoiding amount - 13 input unit for inputting avoiding amounts in the normal and tangential directions which are also preliminarily set besides the tool information. In this connection. if the avoiding amounts in the normal and tangential directions are the same, it suffices for the avoiding amount to input only one value. Reference number 24 represents a moving part of a punching press machine, which receives control output from the avoiding operation unit 23a of the NC program analysis unit 23 to bring the upper cutter wheel 1 into the avoiding motion as illustrated in Figs. 13 and 14, and reference number 25 represents the punching press machine provided with the cutter wheels 1, 6, The operation of the control system proceeds in accordance with the flow chart in Fig. 31. Specifically, in the avoiding operation unit 23a, it in checked in step 51 whether or not the tool used is working wheels and the working wheels are for cutting. When the tool used is not wheels for cutting, the avoiding operation unit 23a does not further advance its operation, thereby quitting the operation. On the other hand, when the tool used is wheels for cutting (cutter 'wheels). avoiding amounts preliminarily inputted in the avoiding amount input unit 22 are set (step S2) to cause the moving part 24 of the machine to perform avoiding motion in the set amounts (step S3). Thus, the control operation is completed.

Such avoiding motion of the cutter wheel 1 as described above is not only useful for the avoidance at the final end of working but also advantageously applicable to a case where working wheels 1, 6 are turned relative to a work 11 in mid course of working to angularly change the direction thereof although avoiding is performed in a different manner. In the next place, the avoiding motion in the latter case will be described.

1 4 For example, in performance of drawing on a work 11 along a continuous line by means of upper and lower working wheels (drawer wheels) 1, 6, if a ram head is raised to elevate the upper drawer wheel 1 at the final end of one drawing step, difference in level is caused between the initial end of the next drawing step and the final end of the preceding drawing step. This aesthetically impairs appearance of a finished work piece. Accordingly, it is desired to carry out such drawing along a continuous line by means of drawer wheels 1, 6 without elevating the upper drawer wheel 1. However, if drawing is carried out continuously without elevating the upper drawer wheel 1 even in a case the drawing line is angularly changed between drawing steps, the work 11 and the drawer wheels 1, 6 are likely to undergo undesired cut or damage.

To cope therewith, according to the present invention, in performance of working on a work 11 by means of a punching press machine using upper and lower working wheels 1, 6 along a continuous working line by moving the work 11 with a punch head kept at a lowered level, if there in difference between final position and direction ofa working step and initial position and direction of the next working step, the punch head is raised to elevate the upper drawer wheel 1. Subsequently. if the positions are different, the work 11 is moved relative to the upper drawer wheel 1, thereby placing the initial position of the next working step under the upper drawer wheel 1. If the directions are different the work 11 is turned or the upper drawer wheel 1 is turned by the holder H of the upper drawer wheel 1. thereby changing the direction of the upper drawer wheel to the initial direction of the next working step.

For example, as shown in Figs. 15 and 17, when working is performed on a work 11 along a working line A and then along a 1 5 - working line A' of the next working stop which intersects the working line A at a predetermined angle at the final end of the working line A. an upper drawing wheel 1 is lifted up from the work 1 1 at the final end of the working line A and then turned to the direction of the working line A' of the next working step.

Subsequently, the upper drawing wheel 1 is lowered by lowering a punch head to proceed to the next working step. In this connection, in working along a working line as shown in Fig. 16, which is an unanguler continuous smooth working line constituted of the working line A and the subsequent working line A', the working can be performed continuously without elevating an upper drawing wheel 1 while changing direction of the working along the working line A,.

The working as described above with reference to Figs. 15 to 17 is carried out under control of a control system as shown in Figs.

32, 33 by way of an example. In Fig. 32, reference number 27 represents an allowance setting unit for setting an allowance with respect to difference in position and direction of working wheels 1, 6 between final position and direction of one working step and initial positiofl and direction of the next working step so as to regard these positions and directions of the working wheels 1, 6 in the working steps as being the same on condition that the positions and directions are the same or that difference between the positions and directions is within a range of the allowance which is preliminarily set. In a sameness checking unit 23b in a NC program analysis unit 23, it is checked whether or not the positions and directions of the working wheels 1, 6 in the working steps are the same G i. e., whether or not these positions and directions are regarded as the same on condition that these are the same or that difference therebetween is within the range set in the allowance - 1 6 setting unit 27). When these are regarded as the same, the working in advanced to the next working step without elevating the upper working wheel 1. When not regarded as the same, the upper working wheel 1 is elevated and command to change the position andlor direction of the upper and lower working wheels 1, 6 is directed to a moving part 24 of the punching press machine 25 to cause the upper working wheel 1 of the machine to perform predetermined motion.

Fig. 33 is a flow chart of the operation of the control system shown in Fig. 32. In the sameness checking unit 23b, it is checked in step S11 whether or not final position and direction of the upper working wheel 1in one working step and initial position and direction of the upper working wheel 1 in the next working step are regarded as the same on condition that these are the same or that difference therebetween in within the range of the allowance. When these are regarded as the same, the working is directly advanced to the next working step. When not regarded as the same. the upper working wheel 1 in elevated by raining a punch head and the position and/or direction of the working wheels 1. 6 is changed relative to the work 11.

In the mode of working according to the present invention which is described above with reference to Figs. 15 to17, 32 and 33, if either of the position and direction of the working wheels 1, 6 at the transitional point between the working steps, the punch head is raised to elevate the upper working wheel 1, thereby preventing damage to the working wheels 1, 6 or work 11. According to the present invention, it in further possible to provide a smooth curved cut line which cannot be obtained by nibbling utilizing conventional punching press technique. Such a smooth cut line is attained by controlling stroke of the punch head, which will be - 1 7 described with reference to Figs. 18 to 28.

Fig. 18 in a diagram showing relationship between movement of a conventional punch and die and movement of a work 11. The punch,in vertically moved repeatedly to punch the work 11 at intervals while moving the work 11 during the intervals in which the punch is elevated, resulting in an unsmooth cut line of a chain of segments A of the shape of the punch as shown in Fig. 19 in plan.

On the other hand, in nibbling utilizing cutter wheels 1, 61 a work 11 can be moved with a punch head lowered to a predetermined level and kept at the level, as diagrammatically shown in Fig. 20.

Accordingly, it is possible to attain a cut line A as shown in Fig. 21 which is far smoother than that shown in Fig. 19. However, if direction of the cutting is changed with the punch head kept lowered, condition of the resulting cut edge is likely to be impaired at the angulation. Further, a blade of the cutter wheel is likely to be undesirably affected.

In view of them according to the present invention, an interpolative function is incorporated in movement of a work 11 relative to upper and lower cutter wheels 1, 6 as diagrammatically shown in Fig. 22 to thereby realize cutting capable of providing a smooth curved cut line with no angulation as illustrated in Fig. 23.

Such e effect is more enhanced by incorporating an interpolative function in vertical movement of a punch head. The interpolative function in vertical movement of the punch head is preferably carried out concurrently with the movement of the work 11 as illustrated in Fig. 26, thereby enabling preferable penetration and release of the upper cutter wheel 1 at the initiation and the termination of the working to be realized, respectively. This advantageously prevents damage or deformation of the work 11. in this connection, Fig. 27 shows locus of movement of an upper cutter wheel 1 relative to a work 11, with lapse of time as an abscissa axis, in which the upper cutter wheel 1 is lowered to and raised from the work 11 at the initial end and the final end of the working, respectively, without incorporating interpolative function in the movement of the upper cutter wheel 1. With the vertical movement of the upper cutter wheel 1 in such locus, the work 11 is likely to undergo deformation or bruise at the initial and final ends of the working. On the other hand, when interpolative function is applied to movement of an upper cutter wheel 1 in ascent and descent of the upper cutter wheel 1 at the initial and final ends of working as illustrated in Fig. 28, a work undergoes no substantial deformation or bruise at the initial and final ends of the working.

In the working wheels 1, 6 used in the working method according to the present invention, it in preferred to use a holder of an auto-index t"e as illustrated in Fig. 25 which is capable of rotational positioning, as a holder H of each of the upper and lower working wheels 1, 6. By the use of a holder of an auto-index type as each of the holders H, working can readily be performed continuously along a continuous curved line as shown in Fig. 24.

In press working using working wheels 1, 6, it is extremely useful to put the upper working wheel 1 under such control that the upper working wheel 1 is lowered to a work 11 at any level and kept at the level. According to the present invention. in press working by means of a punching press machine using working wheels 1, 6, a punch head can be controlled to be at any level. The control system will be described with reference to Fig. 29.

In Fig. 29, reference number 23 represents a NC unit which comprises a working program storage 23c for storing a working - 19 program a tool information storage 23d for storing information on a tool such as a type of the tool (whether the tool is a conventional punch and die or working wheels) and a size of the tool. and a work information storage 23e for storing information on a work such as a material of the work and a thickness of the work. Such required data are inputted to the storages 23c to 23e and, if necessary, the inputted data are rewritten through input means 26 comprising a key board 26a. and a display 26b such an a CRT display.

The NC unit 23 controls a punching press machine 25 in accordance with the working program inputted to the working program storage 23c through the data input means 26 to position a punch head 13 at a predetermined level. Consequently, an upper working wheel 1 is placed in position'according to the position of the punch head 13, and a work 11 i a moved by changing X, Y of the work in X-Y coordinates of a work holder 12 of the punching press machine 25 to perform working on the work 11. In the tool information storage 23d and the work information storage 23e, information on a tool 1, 6 each member of which is held by a tool member holder H of the punching press inachine 25 and information on the work 11 to be worked are set, respectively, through the data input means 26. In the working, the NC unit 23 compares the data set in the tool information storage 23d and in the work information storage 23e with the level of the punch head 13 set in the working program storage 23c to check whether the level of the punch head 13 in the working program is proper or not.

The reason for this is as follows. In such working operation using working wheels 1, 6. the position of the punch head 13 during the working has an influence on the result of the working.

Accordingly, the position of the punch head 13 should carefully be - 2 0 set depending upon thickness and material of the work 11, type of working line (straight line, curved line or the like), type of the working wheels 1, 6. If the punch head 13 is set at a level unsuited to the upper working wheel, not only the work 11 in inappropriately worked but also the working wheels 1, 6 can be damaged. To cope with this, in the present invention, the NC unit has a function to protect the work 11 and working wheels 1, 6 in the following manner.

An acceptable range of the level of the punch head 13 is preliminarily set in relation to the working wheels 1, 6 used in the working. During the working, the set level of the punch head 13 is compared with the acceptable range. If the level in outside the acceptable range, the working is suspended to protect the work 11 and the working wheels 1, 6.

An example of the control by means of the protective function of the NC unit 23 in the working operation using the working wheels 1, 6 is as follows. Information on the upper and lower working wheels 1, 6 each held by a holder H is first pre-set in the tool information storage 23d. It is set that types of tool include working wheels 1, 6 for cutting (cutter wheels) and working wheels for drawing 1, 6 (drawer wheels) as well as a conventional circular punch and die and a conventional rectangular punch and die.

A lower limit of the level of the punch head 13 is set as a parameter of the cutter wheels 1, 6. Separately, a lower limit of the level of the punch head 13 is also set as a parameter of the drawer wheels 1, 6.

When working is carried out in accordance with G code for working by means of working wheels, if the working wheels used are cutter wheels, the level of the punch head to position the blade edge is compared with the lower limit of the level of the punch head which has been set as a parameter of the cutter wheels. If the level of the punch head to position the blade edge < the lower limit of the level of the punch head, operation of the machine is stopped as an alarm When working is carried out in accordance with G code for working by means of working wheels, if the working wheels used are drawer wheels, the level of the punch head to position the blade edge is compared with the lower limit of the level of the punch head which has been set as a parameter of the drawer wheels. If the level of the punch head to position the blade edge < the lower limit of the level of the punch head + a thickness of a work, operation of the machine is stopped as an alarm As described above, according to the working method of the present invention, it is possible to protect a work 11 and working wheels 1, 6 from being subjected to working with a punch head 13 at an unacceptable level by preliminarily setting an acceptable range of a level of the punch head 13 in relation to the working wheels 1, 6, comparing the level of the punch head 13 which has been set in a working program with the acceptable level during the working of the work 11, and suspending the working if the set level is outside the acceptable rang6. Further, if the movement of the punch head is simulated in the NC unit 23, by incorporating substantially the same protective procedure in the simulation, it is possible to check in advance of the working of the work 11 whether the level of the punch head 13 which has been set in the working program is acceptable or not- The protective procedure is carried out during the working for the following reason. If the procedure is carried out upon inputting the working program it is impossible, in a case where information on tool is changed after the input of the working program, to correctly check whether the working program is appropriate or not.

- 2 2 - In the press working by means of working wheels 1, 6 according to the present invention, when the working is cutting of a work 11, it is in some cases desired to provide the working wheels 1, 6 with an offset angle relative to the cutting line. This is made in view of the fact that the work 11 between the upper and lower cutter wheels 1, 6 is sheared by scissors-like action of blades 2, 7 of the cutter wheels 1, 6, and based on the rule of thumb that in the shear by such action, aesthetically better result of cutting can be attained when the cutter wheels are provided with a slight offset angle relative to the cutting line, i. a., the direction of the working.

Accordingly, in one embodiment of the present invention, when working, which in performed according to data read from the working program storage 23c and the tool information storage 23d in the NC unit 23 in the control system illustrated in Fig. 29, in cutting of a work by means of working wheels 1, 6, the working wheels 1, 6 used are provided with an offset angle preliminarily set in the working program. It in to be noted that such an offset angle has significance only in cutting operation utilizing working wheels 1, 6, and thus, is not applied to cutting operation by means of a conventional punch and die nor to any drawing operation irrespective of type of a tool. Accordingly, with respect application of this technique, it is checked in advance of working whether or not the working is cutting operation utilizing working wheels to determine whether an offset angle should be applied or not.

In the above description, the embodiments of working method by means of a punching press machine 25 using working wheels 1, 6 have been describe& However, the present invention may be carried out by means of a punching press machine having a conventional punch - 2 3 - and die (not shown) an well as working wheels 1, 6. In this case, it is set for example, in the working program in the NC unit 23 whether a tool used in working is a conventional punch and die or working wheels, thereby controlling the punching press machine 25 as follows. When the conventional punch and die is used, point-to-point control which corresponds to the conventional punch and die is automatically selected as positioning control of a work 1 1. When the working wheels are used, contouring control is automatically selected which corresponds to the working wheels. Such correspondences between the types of a tool and the types of control are preliminarily established so as to prevent the tools and the work from being damaged due to, for example, application of contouring control to the conventional punch and die or application of cutout action which should be applied to the conventional punch and die to the working wheels.

The present invention is constructed as described above and hence capable of solving problems in working by means of a conventional punching press machine. Heretofore, sheet metal working by means-of a punching press machine has been punching, cutting by repeatedly punching a work, or drawing by means of a punch and die. Accordingly, in nibbling to cut a work along a working line, it is unavoidable to strike the punch with a punch head repeatedly. This causes problems of noise, vibration and aesthetically unsatisfactory result of cut line. In contrast thereto, in the present invention, upper and lower working wheels are used as a tool which are rotated by relative movement between a work and the working wheels. By virtue of this, cutting or drawing along a continuous working line may be carried out with no substantial noise at a markedly increased working efficiency as 2 4 compared with conventional working methods.

Further, when each of the working wheels mounted on the punching press machine in held by a holder having rotational positioning function, direction of the working wheels relative to the working direction can, of course, be selected freely between standard and reverse direction. Further, it is possible to provide the working wheels with a desired offset angle relative to the direction of the working. By virtue of these, cutting capable of providing satisfactory result can be realize& Moreover, by introducing control to change a lowered position of a punch head or to keep the punch a predetermined position during working operation according to particulars the working operation, cutting or drawing operation can be perforimed continuously even along an angulated working line without damaging a tool or deforming a work.

In addition, according to the present invention, cutting operation from which no substantial cutting gap results can be carried out along either of straight and curved working lines. In view of such m advantage which has not been attained by conventional press working by means of a customary punch and die, the present invention is extremely useful as a sheet metal working method. Furthermore, in a punching press machine provided with a conventional punch and die as well as working wheels, correspondences between types of control and types of a tool are preliminarily set prior to working, thereby preventing incorrect operation due to mischoice of types of control on a tool.

Further, in working to cut out a work piece having an intended shape from a parent work by means of a punching press machine provided with cutter wheels, a cutout work-to-be raised - 2 5 from the parent work by the cutting is fitted and retained in the parent work by punching appropriate several sites thereof with a punch. By utilizing advantageous characteristics of the cutter wheels in this manner, it is possible to continuously carry out working operation by means of the cutter wheels. By virtue of this, markedly increased operational efficiency in cutting by means of a punching press machine is achieved - 2 6 -

Claims (11)

1. A method for controlling a punching press machine provided with working wheels as well an a conventional punch and die to carry out. working such as cutting or drawing, said method comprising: establishing correspondences between the conventional punch and die and point-to-point control and between the working wheels and contouring control in a control unit having point-to-point control function for control to repeatedly move a work at intervals taking shortest course to successively place a plurality of portions to be worked under the punch to thereby carry out working such as cutting out successively and contouring contort function for control to move the work along a working course of a straight or curved line, or a working course including straight and curved lines to thereby carry out working such an cutting or shaping continuously, and selecting the corresponding control when working such as cutting or shaping in carried out using the punch and die or the working g wheels,' thereby carrying out working along an intended course of a work.

2. A method for working by means of a pun ching press machine using working wheels as upper and lower tool members each of which in rotatably supported by a shaf t parallel or substantially parallel to a work, said punching press machine having a punch head capable of being kept at an intended position in its stroke for pressing the upper working wheel against the work placed between the upper and lower working wheels to plastically deform the work, said method comprising:

selecting direction of the upper and lower working wheels - 2 7 relative to direction of progress of the cutting as standard direction or reverse direction by turning each of holders of the working wheels in an angular amount of 180 degrees.

3. The method for working according to claim 2, wherein each of the shaf ts of the working wheels is slightly slanted to provide each of the shaft with a first offset angle relative to the surface of the work, and the direction of the working wheels is defined as the standard direction when the cutting is advanced while looking the inclination of the working wheels to the right relative to the direction of progress of the cutting.

4. The method for working according to claim 2 or 3, wherein each of the working wheels is slightly slanted to provide each of the working wheels with a second offset angle relative to the direction of progress of the cutting.

is

5. A method for working by means of a punching press machine using working wheels an upper and lower tool member. said method comprising:

moving the upper working wheel at a final end of a working line of working in the normal direction relative to the working line of a work in a slight amount and then in the direction of progress of the working in a slight amount and then lifted up, or moving the upper working wheel simultaneously in the direction of the progress and in the upward direction relative to the working line of the work in slight amounts to lif t up the upper working wheel.

6. A method for working by means of a punching press machine using working wheels as upper and lower tool members along a working line including its portions via an angulation, said method comprising: raising a punch head at the angulation, which is pressing 2 8 the upper working wheel against a work to such a level that the upper working wheel is brought out of contact with the work, turning each of holders of the upper and lower working wheels to the direction of the next portion of the working line to adjust the direction of the upper and lower working wheels to the direction of the next portion, and lowering the punch head to the level for the working to resume the working.

7. A method for working by means of a punching press machine using working wheels as upper and lower tool members along a continuous curved working line including a straight portion, said method comprising:

turning each of holders of the upper and lower working wheels to adjust the working wheels to the tangential direction relative to the working line. and concurrently with this, adjusting the level of the upper working wheel by controlling a punch head to continuously carry out the working along the continuous curved working line.

8. A mettiod for cutting out an intended work piece from a parent work in the form of a plate by means of a punching press machine using working wheels, said method comprising:

retaining a cutout work or cutout work-to-be raised from a parent work by cutting in the parent work by appropriate several sites, and afterward.

punching out the cutout work or cutout work-to-be by punching.

9. The method according to claim 8, wherein the cutting is performed along an outline of a cutout work to be cut out from a parent work by means of the working wheels with corners of the - 2 9 outline left uncut to retain the cutout work-to-be in the parent work, and afterward, the cutout work-to-be is punched at the corners left uncut by means of a conventional punch and die.

10. The method according to claim 9, wherein the corners left uncut to retain the cutout work-to-be in the parent work, and afterward, the parent work is punched at the corners.

11. The method according to claim 8, wherein the cutting is performed along an outline of a cutout work to be cut out form a parent work by means of the working wheels with corners of the outline left uncut and the resulting cleavage is half-punched to retain the cutout work-to-be in the parent work, and afterward, the corners left uncut are punched.

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