JPS6393594A - Shearing processing equipment - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to the configuration of a press working device for shearing a very thin foil-like workpiece.

[Prior art and its problems]

A method using pneumatic pressure for punching or drilling holes in a plate-shaped workpiece is known. With respect to the finishing force of the workpiece during this machining, it is desirable that there be little ``sag'' or ``burr'' caused by the workpiece being drawn in by the tool and plastically deformed. Particularly when the workpiece is in the form of a foil with a thickness of several tens of micrometers or less, the initial speed at which the punch as a movable blade or the die as a fixed blade begins to penetrate into the workpiece can be suppressed to a low level to minimize the thickness of the workpiece. By softening the impact force applied to the workpiece, the occurrence of "drip" is suppressed, and the travel distance of the punch, that is, the stroke, is kept to the thickness of the workpiece, and the punch is stopped near the position where the punch has finished cutting the foil. Therefore, it is necessary to prevent the occurrence of "kaeshi".

However, with conventional press equipment, it is nearly impossible to keep the punch stroke to an extremely short value of several tens of micrometers or less, which corresponds to the thickness of the foil, and it is almost impossible to set the punch stop position with accuracy commensurate with the thickness of the foil. It is also extremely difficult to control the point so that it is always constant at a point near where the foil has been cut.

Therefore, in the punching of ordinary foil-like workpieces, it is impossible to prevent the punch from moving over a certain long stroke with a certain initial velocity, and the occurrence of "slop" and "burrs" cannot be prevented. Furthermore, punching cannot be prevented, so even if it is possible to prevent ``slips'', it is not possible to prevent ``slips'' from occurring.

[Purpose of the invention]

This invention solves the above-mentioned problems, and allows the moving distance of the movable blade to be controlled to the thickness of the foil-like workpiece, and also allows the initial velocity of the movable blade to be applied to the workpiece from a stationary state. It is an object of the present invention to provide a shearing device that gives a good finish to a workpiece.

[Key points of the invention]

This invention utilizes the distortion of a piezoelectric element as a drive source for a movable blade, so that the moving distance of the punch as a movable blade is approximately equivalent to the thickness K of a foil-like workpiece of several tens of μm or less. , and its value is controllable. Distortion of piezoelectric element and its distortion K
The generated force can be controlled by the load applied to the piezoelectric element, the voltage applied to the piezoelectric element, and K. For this purpose, the drive source of the movable blade is composed of a piezoelectric element and an elastic body for applying a load to the piezoelectric element, and the elastic body is provided with an initial deformation adjusting means to adjust the load on the piezoelectric element. Furthermore, the distance between the punch as a movable blade that performs shearing processing and the die as a fixed blade before processing can be adjusted from a state in which they are in contact with each other by an interval adjustment means.K Therefore, the initial velocity of the die relative to the workpiece K so that it is given from a rest state.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the invention.

A piezoelectric element 1 housed in an insulating case, a steel transmission rod 3 that transmits the vertical deformation of the piezoelectric element 1 to the punch 2, and a spring 4 that applies a compressive load to the piezoelectric element 11C are housed in the case 5. It is stored. The amount of deflection of the spring 4 can be adjusted by adjusting the screw length of the load adjustment bolt 6, and thereby the initial compressive load that the spring 4 applies to the piezoelectric element 1 can be adjusted. The case 5 is fixed to the actuator stand 7 and installed on the pace 8. A mold 9 serving as a die is further installed on the base 8, a metal foil 11 as a workpiece is placed on top of the mold 9, and an upper mold 10 is placed on top of the metal foil 11. A punch 2 is inserted into the upper die 10 and connected to the transmission rod 3 by a sleeve 12. The actuator stand 7 can be finely adjusted in the vertical position with the interval adjustment screw 13, and the punch 2 and the mold 9
You can adjust the distance between the two until they come into contact. Therefore, after aligning the metal foil 11 and the punch 2 in the horizontal direction prior to processing, the tip of the punch 2 is adjusted so that it is in light contact with the upper surface of the metal foil 11. Terminal 1 provided on the outer insulator case of the piezoelectric element 1
4 and a connection terminal 15 provided in the case 5 are connected inside the case 5. Connect the power supply 16 to the connection terminal 15,
When a voltage is applied to the piezoelectric element 1, the piezoelectric element 1 is distorted and expanded in the vertical direction, pushing down the transmission rod 3, and the connected punch 2 is loaded and punches out the metal foil 11. At this time, the punch 2 starts punching the metal foil 11 from a stationary state, so that "sloping" can be prevented from occurring. further up m1
0 applies a static load to the vicinity of the punched portion of the metal foil 11 to suppress deformation of the metal foil 11, thereby further increasing the effect of preventing droop. Further, the moving distance of the punch 2 is equal to the elongation length of the piezoelectric element 1, and this length is equal to y to the thickness of the metal foil 11, so the punch 2 stops at the point where punching is completed and moves over a long stroke. This prevents the occurrence of ``burr''. As described later, piezoelectric element 1
Since the amount of elongation depends on the applied voltage and the spring constant of the spring 4, it is necessary to adjust the applied voltage or replace the spring 4 with one having a different spring constant for thin plates 11 of different thicknesses. Therefore, it can be dealt with. Further, the force required for punching can be adjusted by the voltage applied to the piezoelectric element 1 or the load applied, and this is controlled by the load adjustment port 6.
This is done by adjusting the initial deflection amount of the spring 4. FIG. 2 is a graph explaining that the amount of elongation of the piezoelectric element 1 and the generated force can be adjusted by the above adjustment. This is the amount of deformation of the vertical axis of the piezoelectric element 1 and the spring 4, with the elongation in the positive direction. Further, the horizontal axis F is the load applied to the piezoelectric element 1, and since this is always balanced with the force generated by the piezoelectric element 1, the horizontal axis F also indicates the force generated by the piezoelectric element 1. In the figure, the characteristics when a voltage is applied to the piezoelectric element 1 are the piezoelectric element characteristics 21 when v=0, and the characteristics when the voltage v1 or F2 is applied are the piezoelectric element characteristics 22 when v=v1 or ■=■ 2 is shown as piezoelectric element characteristic 23. Further, the relationship between the amount of deflection (negative direction) of the spring 4 and the load is shown as a spring characteristic 24. Piezoelectric element 1 above
The relationships among the stress T applied to the piezoelectric element 1, the applied electric field E, and the strain S are expressed by the piezoelectric equation 8 (1) where the elastic compliance constant and d are the piezoelectric strain constants.

(As is clear from Equation 11, there is a linear relationship between strain S and stress T using electric field E as a parameter.Furthermore, the deformation scale is strain S, the load or generated force F is stress T, and the voltage V is electric field EK. Since it is proportional, (based on Equation 11, the characteristics of the piezoelectric element 1 shown in FIG.
It can be explained that the piezoelectric element characteristic 21 of =O is translated in parallel.

The value at the point where a straight line indicating these piezoelectric element characteristics, for example piezoelectric element characteristic 22, intersects with the vertical axis. 0 is the amount of displacement when no load is applied to the piezoelectric element IK or no force is generated at V=V1, and the value F' at the point where it intersects with the horizontal axis
oo is the same <force generated by the piezoelectric element when displacement is completely restrained at V=V1] or a load that completely restrains displacement.

Now at V=0, compress the spring 4 and get the initial deflection -Lo/
and its load F. When the piezoelectric element 1 is compressed by , the initial deformation of the piezoelectric element 1 becomes -Lo. This state corresponds to the point Po' on the spring characteristic 24 and the point Po on the piezoelectric element characteristic 21 of -o. When the piezoelectric element IK voltage 1 is applied in this state, the piezoelectric element 1 causes elongation, and the spring 4 is further compressed by this elongation, and becomes flat when the force generated by the elongation of the piezoelectric element 1 becomes equal to the load by the spring 4. to oppose This equilibrium point is defined as point P1 on the piezoelectric element characteristic 22 where V=V in the figure, and the corresponding elongation of the piezoelectric element from the no-load state is defined as L1 + the generated force is defined as Fl. Piezoelectric element 1 is -L
.

Since it is deformed by Llt from , the amount of elongation due to the application of voltage v1 is Lo+L1, which corresponds to the length of pIQl in the figure. If pIQl is extended downward and the intersection point of the spring characteristic 24 is set to P1', the amount of deformation pIQl of the piezoelectric element is equal to the amount of deflection Pi'Qt' of the spring 4, as described above.

Also, Po Ql=PO'Q1'! l /PI Qt
PO=ZPO'(h'P1'=Right angle, so as is clear from the figure, it is a triangle P.

slope A straight line p drawn by giving the orientation of the reciprocal of the spring constant.

It can be determined as the intersection between Pl and the piezoelectric element characteristic 22. When the spring constant of the spring 4 is increased, the initial load on the piezoelectric element 1 remains unchanged. If given, the equilibrium point is a straight line P with different slopes. It is determined as the intersection point P2 between F2 and the piezoelectric element characteristic 22. Since the spring constant is a dog, the slope of the straight line PoP2, which is its reciprocal, is the straight line Po
As the slope becomes smaller than the gradient of Pl, the amount of elongation of the piezoelectric element 1 decreases to F2 Q2, but the generated force becomes F2, which is larger than Fl. When the spring constant is decreased, the equilibrium point shifts to F3, and the amount of elongation becomes large P3Q3 (PIQI), but the generated force is F3.
decreases to Also, the spring constant of spring 4 remains the same and the initial load is F. The initial state of the piezoelectric element 1 when the initial deformation amount -LOI is increased to 1 is the point PO on the piezoelectric element characteristic 21.
It is indicated by I, and the equilibrium point when voltage v1 is applied is point P4 on the piezoelectric element characteristic 22. Straight line PQIP4 and straight line P.

Since the slope is equal to Pl, it is a triangle P as shown in the figure. IP4Q4 and the triangle po plQl are congruent, so the amount of elongation P4Q4=PIQI remains the same, but in this case, a generated force F4 larger than Fl can be obtained. Further, when only the applied voltage is set to 2 greater than Vl, the equilibrium point moves to point P5 on the piezoelectric element characteristics 23, and the amount of elongation is P
It increases from IQI to P5Q5, and the generated force also increases from Fl to F5. The opposite is true when the applied voltage is smaller than V1. In this case triangle PoPIQ1 and triangle pop5Q
Since s are similar, the amount of elongation and the generated force have a linear relationship with respect to the applied voltage, and adjustment is easy.

In reality, there is a hysteresis phenomenon in the characteristics of the piezoelectric element 1, which causes some differences from those shown in Fig. 2, but by applying an initial load with an elastic body, the amount of elongation of the piezoelectric element 1 and the generated force can be changed. It remains possible to adjust the value to the desired value.

In the above embodiment, a compressive load is applied to the piezoelectric element by compressing the spring 4, but on the other hand, the spring 4 is stretched and the piezoelectric element 1 is compressed by the force that tries to return to its original state. A configuration that applies a load may also be used.

〔Effect of the invention〕

In this invention, a driving source for a movable blade of a shearing device for shearing a foil-like workpiece is composed of a piezoelectric element, an elastic body that applies a compressive load to the piezoelectric element by deformation, and a deformation amount of the elastic body, i.e. Since the configuration includes a means for adjusting the compressive load applied to the piezoelectric element and an interval adjusting means that can adjust the distance between the movable blade and the fixed blade over a range up to the point where they come into contact, the stroke of the movable blade is adjusted to the extent that the piezoelectric element It is possible to make the stroke of the movable blade equal to the thickness of the foil-like workpiece, and therefore, during shearing,
It is possible to prevent burrs from occurring. In addition, since the position of the movable blade can be adjusted to bring it into contact with the workpiece before machining, the initial speed of the movable blade during shearing can be kept low, thereby preventing the occurrence of "drip". These can improve the finish of the workpiece.

The amount of deformation and generated force of the piezoelectric element can be adjusted by adjusting the amount of deformation of the elastic body that applies a compressive load, changing the elastic constant of the elastic body, adjusting the voltage applied to the piezoelectric element, etc. The appropriate stroke and driving force of the movable blade can be selected according to the thickness and material of the workpiece, and therefore automatic control of the machining process is also possible.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a graph showing the relationship between the force or sway load generated by a piezoelectric element and the amount of deformation. 1: piezoelectric element, 2: punch, 3: transmission rod, 4: spring, 6
: Load adjustment bolt, 9: Mold, 11: Metal foil, 13: Spacing adjustment screw, 16: Power supply. -13= Figure 1

Claims (1)

[Claims] 1) In a device that has a movable blade and a fixed blade and performs shear processing on a workpiece placed between the movable blade and the fixed blade, a piezoelectric element and a load are applied to the piezoelectric element through deformation. an elastic body, a means for adjusting the initial deformation amount of the elastic body;
A distance adjusting means is provided in which the distance between the movable blade and the fixed blade before processing is adjusted according to the contact state between the two, and a voltage is applied to the piezoelectric element in a state where a load is applied by the elastic body. A shearing device characterized in that a movable blade is driven directly or indirectly by the distortion of the piezoelectric element in one direction, and shearing of a foil-shaped workpiece is performed.