Abstract:
Disclosed is a punch pressing machine requiring no turret, having punch units and die units as die sets, the number of which is not inferior to a turret punch pressing machine, and exhibiting a working accuracy superior to the turret punch pressing machine. A plurality of punch units and die units are disposed in two or more lines on a mounting plate member. A hammer member confronting the respective punch and die units is positioned in X-and-Y axis directions, whereby a workpiece can undergo necessary punch press working.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a punch pressing machine equipped with a plurality of punch and die units. 
     A punch press having a plurality of die sets has hitherto been known as a turret punch pressing machine. 
     The turret punch press, however, presents a problem in which a working accuracy depends on the positioning accuracy of the turret to align the punch over the die. 
     Known also is a punch pressing machine having the plurality of punch/die sets requiring no index positioning process. In this pressing machine, the plurality of die sets are simply arranged in one line, and the number of die sets is small. Hence, there arises such a problem that a working range is limited as compared with the turret punch pressing machine. 
     SUMMARY OF THE INVENTION 
     It is a primary object of the present invention in the light of the foregoing points to provide a non-turret type punch pressing machine equipped with a multiplicity of die sets. 
     According to one aspect of the present invention which has been devised to obviate the above-mentioned problems, there is provided a punch pressing machine comprising: a frame; work hands disposed on the frame in such a state as to be movable in X-and-Y axis directions on the plane of the frame for supporting a workpiece; a plurality of punch and die units capable of catching the workpiece from above and under; a mounting plate member, provided on the frame on which the punch and die units are arranged in at least two lines respectively in a posture orthogonal to the surface of the workpiece; and a hammer member disposed upwardly of the punch units in the plurality of lines for selectively performing a punching operation for each of the punch units while being moved and located in the X-and-Y directions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the present invention will become apparent during the following discussion taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a side elevation showing one example of a punch pressing machine according to the present invention; 
     FIG. 2 is a front view of the punch pressing machine; 
     FIG. 3 is a top view of the punch pressing machine of this invention; and 
     FIG. 4 is a block diagram showing one example of a drive system of a hammer member. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of a punch pressing machine of the present invention will hereinafter be described with reference to the drawings. 
     Referring to FIGS. 1 through 3, the numeral 1 represents a frame assuming a substantially C-shape in side (expressed in the reverse direction in the side elevation of FIG. 1). Designated at 2 is a work table horizontally mounted on the upper surface of a lower frame 1b inwardly of a cavity 1a in the frame 1. This table 2 is mounted with work hands 3 advanceable and retreatable (right and left directions of FIG. 1 which will hereinafter be referred to as X-axis directions) with respect to an opening portion of the cavity 1a in the frame 1 through a motor and a feed screw mechanism (unillustrated). At the same time, the table 2 itself is so mounted in a lower frame 1b as to be advanceable and retreatable in directions orthogonal to the X-axis directions with respect to the frame 1 (vertical directions on the sheet surface which will hereinafter be referred to as Y-axis directions) through the motor and the feed screw mechanism. 
     On the other hand, a base plate 1d is disposed on the lower frame 1b on the side opposite of the table 2, i.e., at the opening portion of the frame cavity 1a in the X-axis directions of the cavity 1a of the frame 1. A mounting plate member 4 is formed with a gap 4a into which a workpiece (blank) is insertable on the plate 1d and shaped in a laterally elongate C-like configuration in side view. The mounting plate member 4 is so mounted as to be turnable about a vertical turning shaft 5 with the opening portion of the gap 4a being directed to the table 2. This mounting plate member 4 can be moved horizontally clear of table 2 so that the mounting plate member 4 can be rotated about shaft 5 and, for this purpose, a slide mechanism 5a is connected to the shaft 5. Note that the table 2 may incorporate a relief function to avoid an interference of turning of the plate member 4 with the table 2. 
     Then, as one example, an upper member 4b positioned above the gap 4a of the mounting plate member 4 is detachably provided with punch units 6a arranged by sixes in two lines. Further, a lower member 4c positioned below the gap 4a is provided with die units 7a arranged by sixes in two lines corresponding respectively to the 2-line punch units 6a. 
     Each die unit 7a is so located as to slightly protrude into the gap 4a of the plate member 4 when it is to be used for punch press work. If unused, however, the die unit is located flush with or under the upper surface of the lower member 4c. Therefore, the lower end surface of each die unit 7a is supported on a lift mechanism (not shown) which utilizes a cylinder, a cam and the like. Only the one selected die unit 7a is so supported as to slightly protrude from the upper surface of the lower member 4c. According to the present invention, a plurality of die units 7a are referred to as a die set. 
     Indicated at 8 is a hammer member provided opposite to the above-mentioned punch and die units 6a, 7a with a hydraulic cylinder serving as a driving source in the upper frame 1c of the frame 1. This hammer member 8 is so supported as to be movable and locatable with respect to both the X and Y axes through a movement mechanism based on a stroke actuator such as, e.g., an air cylinder, whereby the hammer member can be positioned on the upper surface of each of the plurality of punch units 6a. 
     FIG. 4 is a mechanism block diagram showing one example of a drive control system of the hammer member 8. The symbol 8a denotes a hydraulic cylinder; and 8b a piston rod having its tip formed as a hammer for punching. A servo control drive hydraulic system 8c of the cylinder 8a is constructed of a pressure oil source 8d, a servo control valve 8e to be servo-controlled, pipes 8f, a stroke sensor 8g and a servo control unit 8S. 
     The symbol 8h represents an X-and-Y axis movement mechanism of the hydraulic cylinder 8a. This mechanism includes a member 8k fitted integrally with the hydraulic cylinder 8a wherein the member 8k is driven, with the aid of the air cylinder 8i, connected to the hydraulic cylinder 8a, in the X-axis directions and with aid of a feed screw mechanism 8j in the Y-axis directions. 
     In the thus constructed punch pressing machine of this invention, the working position of the workpiece (blank) such as a steel sheet or the like held in the posture horizontal to the work hands 3 is set between the predetermined punch unit 6a and die unit 7a by the positioning process of the work hands 3 in the X-and-Y axis directions. Simultaneously, the hammer member 8 is positioned with respect to the punch unit 6a concerned, and punching points of this hammer member 8 are basically the same with the conventional punch pressing machine. 
     In the hammer member 8 of this invention, however, the hydraulic cylinder 8a serves as the driving source and is driven while being servo-controlled by the control system composed mainly of the servo control valve 8e, the servo control unit 8S and the stroke sensor 8g. It is therefore possible to arbitrarily accelerate and decelerate especially the stroke motion. Hence, a dropping speed of the punch is infinitesimally controllable in accordance with a hardness and thickness of the workpiece. High-speed working with less noise is thus attainable. 
     On the other hand, the punch pressing machine according to the present invention includes the plurality of punch units 6a and die units 7a which are arranged in two lines, respectively. When the working position of the workpiece held by the work hands is set in the predetermined die set position, the hammer member 8 is positioned by the support mechanism thereof with respect to the X and Y axes above the punch unit 6a in the corresponding die unit. The punching operation is performed therein. Hence, this positioning control may not be as high as the turret punch press for index-positioning the die set. In this respect, there is an advantage in which the control drive system can be simply structured. 
     On the other hand, the punch pressing machine according to this invention has the plurality of die sets arranged in two or more lines. Therefore, when setting the working position of the workpiece to the predetermined die set by using the work hands 3, it can be considered that the work hands 3 interfere with other die units 7a. 
     According to the present invention, for avoiding this point, other unused die units 7a are located flush with or under the upper surface of the lower member 4c of the base member 4. Only the die unit to be used is protruded slightly from the upper surface of the lower member 4c by operating the lift support mechanism thereof. 
     Further, when replacing each die set, the mounting base member 4 of the die set can be turned about the shaft 5 for facilitating the operation. 
     Provided according to the present invention discussed above are the plurality of die sets in two or more lines which consist of the plurality of paired punch units and die units. The hammer member is so disposed as to be fixedly locatable with respect to the two X-and-Y axes for each die set. It is therefore possible to attain a variety of punch press works which are not inferior to those of the turret punch pressing machine without requiring the replacement of the die sets as compared with the conventional punch pressing machine equipped with the one-line die set. 
     Besides, the following advantage that only the workpiece and hammer member 8 may be positioned on the occasion of the punch press work. The turret index operation as done in the turret punch pressing machine, i.e., positioning on the die side is not effected. The working accuracy is more favorable, correspondingly. This advantage is brought about because of the fact that the die unit is not selected based on the turret structure. For this reason, the structure is simplified, and the profitability is given in terms of economical aspect such as manufacturing costs and maintenance costs. 
     Furthermore, the hammer member is drive-controlled by the servo-controlled hydraulic cylinder. The punching speed can be arbitrarily controlled during the operation in accordance with the content of the workpiece. Hence, a silent punch press work can be actualized. 
     Although the illustrative embodiment of the present invention has been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to this embodiment. Various changes or modifications may be effected by one skilled in the art without departing from the scope or spirit of the invention.