JP5560167B2 - Thin plate work fixing device and thin plate work processing device using the same - Google Patents

Description

  The present invention relates to a fixing device for fixing a thin plate workpiece in a predetermined position while maintaining the shape of the thin plate workpiece during surface processing of the thin plate workpiece, and a thin plate workpiece processing apparatus using the fixing device.

  A thin plate workpiece used for an aircraft body or the like is a processing object in which a metal thin plate is formed in advance into a predetermined three-dimensional shape by stretch forming or the like. The thin plate workpiece is subjected to surface processing such as a thinning process on at least the upper surface thereof for the purpose of weight reduction. Since such a thin plate workpiece has a three-dimensional shape and is easily deformed, when performing surface processing of the thin plate workpiece, the thin plate workpiece is held at a predetermined position so as to keep the shape of the thin plate workpiece. Need to be fixed.

  Therefore, conventionally, a processing apparatus that performs surface processing of a thin plate workpiece is provided with a plurality of cylinder rods that firmly fix the thin plate workpiece while supporting the thin plate workpiece from below using vacuum suction as described in Patent Document 1. There is something. The plurality of cylinder rods are erected along the longitudinal direction and the width direction of the thin plate workpiece with a space therebetween. Each cylinder rod includes a rod, a jack for adjusting the height of the rod, and a suction pad attached to the tip of the rod. The suction pad can suck the thin plate workpiece by evacuation.

  When a thin plate workpiece is fixed at a predetermined position using these cylinder rods, first, each jack is used based on drawing data of the thin plate workpiece (that is, data on the three-dimensional shape of the thin plate workpiece at the time of design). By adjusting the height of the rod, the height position of each suction pad is adjusted to a position corresponding to the three-dimensional shape. Next, a thin plate work is placed on each suction pad and is vacuum-sucked by the suction pad.

US Pat. No. 5,163,793

  However, in the apparatus described in Patent Document 1, increasing the support rigidity of a thin plate work leads to an improvement in shape accuracy, but there is a problem that it is difficult to improve the support rigidity. Specifically, to increase the support rigidity, it is effective to increase the holding position of the thin workpiece by each suction pad and reduce the pitch between the holding positions. However, the suction pad has a large diameter, and the suction pad Since the structure for adsorption by the pad is complicated, the adsorption pad and the rod cannot be arranged at a narrow pitch, and the increase in the arrangement number causes a significant increase in cost. Therefore, it is difficult to narrow the interval between adjacent cylinder rods. As a result, it becomes difficult to improve the support rigidity of the thin plate workpiece, and it is difficult to suppress the deflection of the thin plate workpiece caused by the load received from the tool during the processing of the thin plate workpiece.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thin plate workpiece fixing device capable of improving the support rigidity of a thin plate workpiece and performing surface processing with high accuracy.

  In order to solve the above problems, the thin plate workpiece fixing device of the present invention is a fixing device for fixing the thin plate workpiece in a predetermined position, and is arranged in a plurality of different specific directions on a horizontal reference plane. And a plurality of first cylinder rods that fix the lower surface of the thin plate workpiece and at least one second cylinder rod that is disposed between the adjacent first cylinder rods and supports the thin plate workpiece from below. The first cylinder rod is provided at the tip of the first rod, a first height adjusting portion that changes the height of the first rod, and the first rod, The second cylinder rod has a second rod whose tip abuts against the lower surface of the thin workpiece, and a second height adjusting unit that changes the height of the second rod. The The second rod has a contact portion for supporting the thin plate workpiece from below by contacting the lower surface of the thin plate workpiece from below, and the first cylinder rod and the second cylinder rod Are arranged so as to stand vertically with respect to a horizontal reference plane, and at least two of the first cylinder rods are arranged along a specific direction of the thin plate work and are adjacent to each other. At least one second cylinder rod is disposed between the cylinder rods, and the second cylinder rod is smaller than the first cylinder rod with respect to the external dimensions in the specific directions.

  The fixing device of the present invention makes it possible to reduce the interval between the cylinder rods that support the thin plate workpiece from below in order to stably fix the thin plate workpiece that is easily deformed while maintaining its shape.

  Specifically, the first cylinder rods having the suction pads for sucking the thin plate workpieces are arranged in a specific direction (for example, the width direction of the thin plate workpieces) on the horizontal reference surface, and the first cylinder rods of the first cylinder rods are arranged. A second cylinder rod having no suction pad is disposed between them. The second cylinder rod supports the thin plate workpiece by bringing the tip of the second rod into contact with the lower surface of the thin plate workpiece.

  And since a 2nd cylinder rod has a dimension smaller than a 1st cylinder rod about the external dimension regarding a specific direction (for example, the width direction of a thin-plate workpiece | work), reducing the support space | interval of a thin-plate workpiece | work about the said specific direction. Is possible.

  With this configuration, it is possible to support the thin plate workpiece in a state where the support point interval of the thin plate workpiece is shortened as compared with the fixing device including only the first cylinder rod having the suction pad, and the support rigidity of the thin plate workpiece. Can be increased. As a result, even when a tool is pressed when processing a thin plate workpiece, the deflection of the thin plate workpiece can be reduced, and the thin plate workpiece can be processed with high accuracy.

  Moreover, it is preferable to further include a work edge gripping part for gripping the edge of the thin plate work. By further including the workpiece edge gripping portion, it is possible to suppress vibration of the edge of the thin plate workpiece that occurs when processing the thin plate workpiece.

  The thin plate workpiece is easily deformed because it is made of a material such as a metal thin plate, and particularly has a property that the edge portion easily vibrates during surface processing of the thin plate workpiece. Also, even if several points on the lower surface of the thin plate workpiece are fixed to the suction pad of the first cylinder rod, the edge of the thin plate workpiece may be a free end that is not restrained by the suction pad due to the arrangement of the suction pad, etc. Yes, it may be difficult to suppress vibrations using only the suction pad.

  Therefore, by gripping the edge of the thin plate workpiece by the workpiece edge gripping part, the vibration of the edge of the thin plate workpiece that occurs when machining the thin plate workpiece can be suppressed, and there is no possibility that the thin plate workpiece will come off the suction pad, and more accurate Can be processed well.

  It is preferable that the thin plate workpiece has a shape in which an edge thereof is inclined with respect to the reference plane, and the workpiece edge gripping portion grips an edge of the thin plate workpiece.

  According to this configuration, when the edge of the thin workpiece is inclined with respect to the reference surface on which the first and second cylinder rods are erected, the suction pad may be difficult to be attracted to the edge of the thin workpiece. In such a case, the entire peripheral part of the edge of the thin plate workpiece or most of the peripheral part becomes a free end that is not constrained by the suction pad.In such a case, the edge of the thin plate workpiece is moved by the workpiece edge gripping part. By gripping the edge of the thin plate workpiece, even if it is a three-dimensional thin plate workpiece having a large warped edge, vibration of the edge of the thin plate workpiece that occurs when processing the thin plate workpiece can be suppressed. As a result, there is no possibility that the thin plate workpiece is detached from the suction pad, and processing can be performed with higher accuracy.

  Furthermore, the workpiece edge gripping portion has an upper surface contact portion having a shape capable of contacting the upper surface of the thin plate workpiece, and a lower surface contact portion having a shape capable of contacting the lower surface of the thin plate workpiece. The workpiece edge gripping portion sandwiches the thin plate workpiece between the upper surface contact portion and the lower surface contact portion by reducing the distance between the upper surface contact portion and the lower surface contact portion. It is preferable to do this.

  According to this configuration, by reducing the distance between the upper surface contact portion and the lower surface contact portion of the work edge gripping portion, a force can be applied from both the upper surface and the lower surface of the thin plate workpiece, The workpiece can be gripped stably.

  A pedestal that supports each of the first cylinder rod and the second cylinder rod in an upright position so as to be movable at least in the specific direction; and the pedestal is moved to a predetermined position along the specific direction. It is preferable to further include an interval changing mechanism including a drive unit that changes the interval between the first cylinder rod and the second cylinder rod in the specific direction by stopping the first cylinder rod and the second cylinder rod.

  According to this configuration, each of the first cylinder rod and the second cylinder rod is supported in an upright state by the pedestal portion, and the pedestal portion is moved in a specific direction to stop the pedestal portion at a predetermined position. Thereby, the space | interval of a 1st cylinder rod and a 2nd cylinder rod can be changed easily.

  Further, the first height adjusting unit converts the rotational drive force generated by the support unit that supports the first rod so as to be movable in the up and down direction, the electric motor, and the linear drive force in the vertical direction. A power transmission unit that converts and transmits the linear driving force to the first rod, and the second height adjustment unit includes an air cylinder in which a lower end portion of the second rod is inserted freely. It is preferable to provide.

  The first height adjusting portion of the first cylinder rod converts the electric motor and the rotational driving force of the electric motor into a linear driving force in order to move the suction pad and the first rod that supports the suction pad up and down. And a power transmission unit that transmits the linear driving force to the first rod, and a complicated and large mechanism is required. On the other hand, since the second cylinder rod has a simple structure having no suction pad, the second height adjustment unit may employ a mechanism capable of generating a driving force that can adjust the height of the second rod. Therefore, by adopting an air cylinder capable of adjusting the height of the second rod as the second height adjusting portion, the structure of the second cylinder rod becomes simpler than that of the first cylinder rod, and further miniaturized. Can be achieved. As a result, the second cylinder rod can be brought closer to the first cylinder rod.

  Further, the suction pad can be deformed in accordance with the shape of the surface of the thin plate workpiece contacting the tip thereof and can be brought into close contact with the lower surface of the thin plate workpiece, and the first cylinder rod can be It is preferable that at least a part of the seat which is provided at the tip of the rod and can contact the thin plate workpiece further has a spherical surface, and the seat is disposed inside the suction pad.

  According to such a configuration, the suction pad in the first cylinder rod can be deformed in accordance with the shape of the thin workpiece in order to perform evacuation without causing air leakage between the thin workpiece and the suction pad. . Furthermore, the 1st cylinder rod is provided with the seating part which has a spherical surface in the front-end | tip of a 1st rod separately from a suction pad. In such a structure, regardless of the orientation and shape of the thin workpiece, the spherical surface of the seating part can always make point contact directly with the lower surface of the thin workpiece, and force is applied in the direction extending in the normal direction of the lower surface of the thin workpiece. Can be supported stably. Thereby, the thin plate work is rigidly supported by the first rod through the seating portion. As a result, compared to a structure in which the thin plate workpiece is held only by the suction pad, the rigidity of the portion holding the thin plate workpiece at the tip of the first cylinder rod is improved, and the positioning accuracy and the support rigidity of the thin plate workpiece are improved.

  Further, a thin plate work processing apparatus according to the present invention is a thin plate work fixing device according to any one of claims 1 to 8, and a tool for performing surface processing of the thin plate work fixed at a predetermined position by the fixing device. And a tool moving unit that moves the tool on the thin plate workpiece.

  According to such a configuration, the thin plate workpiece can be supported at a shorter interval between the support points of the thin plate workpiece by using the fixing device of the present invention, and the support rigidity of the thin plate workpiece can be increased. As a result, even when a tool is pressed when processing a thin plate workpiece, the deflection of the thin plate workpiece can be reduced, and the thin plate workpiece can be processed with high accuracy.

  As described above, according to the thin plate workpiece fixing device and the processing device using the same according to the present invention, the support rigidity of the thin plate workpiece can be increased. As a result, the deflection of the workpiece during the processing of the thin plate workpiece is reduced. Can be processed with high accuracy.

It is a whole perspective view concerning one embodiment of a processing device provided with the fixing device of the thin plate work of the present invention. It is a perspective view of the fixing device of FIG. It is the III-III sectional view taken on the line of the fixing device of FIG. FIG. 2 is an explanatory diagram for explaining that a support point interval is calculated based on a machining allowable value and a deflection amount of a thin plate workpiece and positioning of the first and second cylinder rods is performed in the fixing device of FIG. 1. FIG. 2 is an enlarged front view of a work edge gripping part of FIG. 1. FIG. 6 is an enlarged perspective view of the preload mechanism of FIG. 5 and its surrounding clamps and receiving portions. It is an expanded sectional view which shows the spherical seating part inside the suction pad of FIG. 1, and its peripheral part. It is sectional drawing of the 1st height adjustment part of FIG. It is sectional drawing of the 2nd height adjustment part of FIG. It is a figure which shows the shift | offset | difference with NC processing data in the processing method of a thin-plate workpiece | work, and the position of an actual thin-plate workpiece | work. It is a figure which shows the shift | offset | difference of the position of the reference point on drawing data in the processing method of a thin plate workpiece, and the actual reference point of a thin plate workpiece. It is a figure which shows the shift | offset | difference of the position of the reference point on the processing range drawing of the thin plate workpiece on NC processing data in the processing method of a thin plate workpiece, and the reference point of an actual workpiece. It is a figure which shows the original processing position on NC processing data in the pocket hole processing in the processing method of a thin-plate workpiece. It is a figure which shows the processing position after correction | amendment in the pocket hole processing in the processing method of a thin-plate workpiece | work. It is the figure which performed correction | amendment which raises the processing position after correction | amendment in the pocket hole processing in the processing method of a thin-plate workpiece | work, and correct | amended which ensures minimum residual thickness.

  Next, a thin plate workpiece fixing device and a thin plate workpiece processing apparatus using the same according to the present invention will be described in more detail with reference to the drawings.

  The fixing device 2 of the present embodiment is a fixing device that stably fixes a thin plate workpiece W that is easily deformed while maintaining its shape, in order to reduce the interval between cylinder rods that support the thin plate workpiece W from below. As two types of cylinder rods, a first cylinder rod 5 having a suction pad and a second cylinder rod 6 that directly supports a thin workpiece W at the tip of the rod without using a suction pad are provided upright (FIG. 2-3).

  And the processing apparatus 1 of this embodiment is equipped with such a fixing device, can reduce the deflection of the thin plate workpiece W during processing of the thin plate workpiece W, and can perform processing with high accuracy. is there.

  Hereinafter, the processing device 1 and the fixing device 2 will be described in order.

(Overall configuration of processing equipment)
A processing apparatus 1 for a thin plate workpiece W shown in FIG. 1 is a device that performs surface processing of a thin plate workpiece W having a complicated three-dimensional shape made of a thin metal plate used in an aircraft body or the like. The processing apparatus 1 according to the present embodiment performs, for example, a thinning process or a pocket hole process for forming a large number of recesses by partially cutting and removing the surface of the thin workpiece W in order to reduce the weight.

  The processing apparatus 1 includes a fixing device 2, a tool 71, and a tool moving unit 72.

  The fixing device 2 fixes the thin plate workpiece W at a predetermined position within the movable range of the tool 71. The configuration of the fixing device 2 will be described in detail later.

  The tool 71 is a cutting tool such as a milling cutter for performing 5-axis machining. The tool 71 of the present embodiment reduces the weight of the thin plate workpiece W by performing so-called thinning processing or pocket hole processing in which a large number of recesses (pockets) are formed around the surface of the thin plate workpiece W to be thinned. Do.

  As shown in FIG. 1, the tool moving unit 72 moves the tool 71 on the thin plate workpiece W in the five-axis direction. That is, the tool moving unit 72 includes a longitudinal direction moving unit 72 a that moves the tool 71 in the longitudinal direction X of the thin plate workpiece W, a width direction moving unit 72 b that moves the tool 71 in the width direction Y of the thin plate workpiece W, and the tool 71. Is moved in the height direction (that is, the thickness direction) Z of the thin plate workpiece W, and the rotational movement unit is configured to rotate the tool 71 on the thin plate workpiece W in two rotational directions α and β. 72d. The two rotation directions α and β are, for example, in a relationship in which the rotation axes are orthogonal to each other.

  Here, the rotational movement part 72d turns the tool 71 in two rotational directions α and β. In the present embodiment, the rotation direction α is a direction that rotates around the longitudinal direction X so as to be along the width direction of the thin plate workpiece W, while the rotation direction β is along the longitudinal direction of the thin plate workpiece W. This is the direction of rotation around the width direction Y.

  The tool 71 is detachably attached to a tool spindle 72e provided in the rotational movement unit 72d.

(Overall configuration of the fixing device 2)
As shown in FIGS. 1 to 3, the fixing device 2 includes a workpiece lower fixing portion 3 that fixes the thin plate workpiece W from below, and a workpiece edge holding portion 4 that holds the four edges of the outer periphery of the thin plate workpiece W. ing.

  The work lower fixing portion 3 includes a plurality of first cylinder rods 5, a plurality of second cylinder rods 6, and an interval changing mechanism 8.

  The first cylinder rod 5 and the second cylinder rod 6 are spaced apart from each other in the longitudinal direction X of the thin workpiece W so as to be arranged in a plurality of different specific directions on the base 1a of the processing apparatus 1 which is a horizontal reference surface. And are erected along the width direction Y, respectively. The first cylinder rod 5 and the second cylinder rod 6 are respectively arranged via the interval changing mechanism 8 in a state where the first cylinder rod 5 and the second cylinder rod 6 are set up vertically with respect to the pedestal 1a of the processing apparatus 1 which is a horizontal reference surface. Between the first cylinder rods 5, one second cylinder rod 6 is disposed one by one. Two or more second cylinder rods 6 may be arranged. The “plural specific directions” may be different from the longitudinal direction X and the width direction Y of the thin workpiece W.

  As shown in FIG. 3, the first cylinder rod 5 is provided at the tip of the first rod 11, the first height adjusting unit 12 that changes the height of the first rod 11, and the first rod 11. And a suction pad 13 for sucking the thin plate workpiece W.

  The first rod 11 is a rod-like member, and a passage 11a (see FIGS. 7 to 8) through which air passes is formed in the direction in which the first rod 11 extends. The first rod 11 can support the suction pad 13 at the tip thereof, and has sufficient rigidity to secure the inside of the passage 11a in a vacuum state for vacuuming, such as steel. Manufactured with a high-strength metal material.

  The first height adjusting unit 12 is a mechanism for moving the first rod 11 up and down. As shown in FIG. 8, for example, the driving electric motor 12 a and the rotational driving force of the electric motor 12 a are moved up and down. A power transmission portion 12b that converts the linear driving force toward the direction and transmits the linear driving force to the first rod 11 and a support portion 12c that supports the first rod 11 so as to be movable in the vertical direction are provided. The electric motor 12a, the power transmission part 12b, and the support part 12c are accommodated in the casing 12d. In the present embodiment, a ball screw mechanism is illustrated as an example of the power transmission unit 12b, but other power transmission mechanisms may be employed.

  As shown in FIG. 7, the suction pad 13 is made of, for example, a bellows-like cylinder and is made of a material such as rubber having flexibility. When the suction pad 13 comes into contact with the lower surface of the thin workpiece W, the suction pad 13 is deformed in accordance with the shape of the lower surface of the thin workpiece W. Thereby, the front end edge of the suction pad 13 can be adhered to the surface of the thin workpiece W with good airtightness. With the suction pad 13 in close contact with the thin plate workpiece W, the air in the suction pad 13 is extracted through the passage 11a of the first rod 11 by the vacuum pump V shown in FIG. Vacuum adsorption is possible.

  As shown in FIG. 7, the first cylinder rod 5 of the present embodiment further includes a seating portion 16 having at least a part of a spherical surface 16 a that can contact the thin plate workpiece W. The seating portion 16 is disposed inside the suction pad 13. The seating portion 16 is fixed to the tip of the first rod 11 via the connecting portion 19. The spherical surface 16a of the seating portion 16 can reliably contact the lower surface of the thin plate workpiece W regardless of the shape and orientation of the thin plate workpiece W facing the spherical surface 16a. A spherical seat 16 fixed to the tip of the first rod 11 directly contacts the thin plate workpiece W and supports it.

  As shown in FIGS. 3 and 9, the second cylinder rod 6 has a second rod 14 whose tip 14 a abuts on the lower surface of the thin plate workpiece W, and a second height that changes the height of the second rod 14. And an adjusting unit 15.

  In the present embodiment, the tip 14a of the second rod 14 is a contact portion that supports the thin plate workpiece W from below by directly contacting the lower surface of the thin plate workpiece W from below. In addition, you may provide the contact part of the 2nd rod 14 and another member in the front-end | tip 14a of the 2nd rod 14. FIG.

As shown in FIG. 9, the second height adjusting unit 15 includes an air cylinder 15a.
The air cylinder 15a has an opening 15b at its upper end, and the lower end portion 14a of the second rod 14 is inserted into the opening 15b so as to reciprocate up and down. Compressed air is supplied into the air cylinder 15a by the air pump A, and the height of the second rod 14 is changed by supplying and discharging the compressed air. The air cylinder 15a is accommodated in the casing 15c.

  The space | interval change mechanism 8 has the some width direction change part 17 and the longitudinal direction change part 18, as FIG.

  The width direction changing unit 17 changes the intervals in the width direction Y of the plurality of first cylinder rods 5 and second cylinder rods 6 arranged in the width direction Y of the thin plate workpiece W.

  On each width direction change part 17, the some 1st cylinder rod 5 and the 2nd cylinder rod 6 are attached so that movement in the width direction Y is possible. Specifically, the width direction changing portion 17 corresponds to each of the first cylinder rod 5 and the second cylinder rod 6 and extends in the width direction in a state where each of the first cylinder rod 5 and the second cylinder rod 6 stands. A pedestal portion 17a that is movably supported in Y, and the pedestal portion 17a is moved to a predetermined position along the width direction Y and stopped to stop the first cylinder rod 5 and the second cylinder rod 6 in the width direction. And a drive unit 17b for changing the interval of Y. The pedestal portion 17a is guided to be movable in the width direction Y by the guide portion 17c. The individual first cylinder rods 5 and the second cylinder rods 6 can reciprocate independently along the width direction Y by these drive portions 17b.

  The longitudinal direction changing unit 18 changes the intervals in the longitudinal direction X of the plurality of first cylinder rods 5 and second cylinder rods 6 arranged in the longitudinal direction X of the thin plate workpiece W. Specifically, the longitudinal direction changing unit 18 is disposed along the longitudinal direction X of the thin plate workpiece W.

  The longitudinal direction changing unit 18 includes a guide unit 18 a that guides each individual width direction changing unit 17 in the longitudinal direction X, and a drive unit 18 b attached to each individual width direction changing unit 17. A plurality of width direction changing portions 17 are attached to the guide portion 18a so as to be movable in the longitudinal direction X. The individual width direction changing units 17 can be moved in the longitudinal direction X independently by these driving units 18b. Thereby, the first cylinder rod 5 and the second cylinder rod 6 that are placed on a certain width direction changing portion 17, and the first cylinder rod 5 and the second cylinder that are placed on the adjacent width direction changing portion 17. The space | interval about the longitudinal direction X between the rods 6 can be changed.

  As shown in FIG. 4, the support interval L between the first rod 11 of the adjacent first cylinder rod 5 and the second rod 15 of the second cylinder rod 6 is the pressing force F received from the tool 71 and the thin plate workpiece W. It is calculated from conditions such as the plate thickness t and the processing allowable value γ. Based on the calculated support interval L, the width direction changing unit 17 adjusts the interval between the first rod 11 of the first cylinder rod 5 and the second rod 14 of the second cylinder rod 6.

  In the present embodiment, as shown in FIG. 4, the second cylinder rod 6 has a width Y <b> 1 that is smaller than the first cylinder rod 5 with respect to the outer dimension (that is, the width Y <b> 2) in the width direction Y of the thin workpiece W. Therefore, the occupied area is smaller than that of the first cylinder rod 5 in the width direction Y. Thereby, the support interval of the thin plate workpiece W can be reduced.

  The interval L between the adjacent first cylinder rod 5 and the second cylinder rod 6 is appropriately changed and set according to the dimensional shape and processing conditions of the thin plate workpiece W, and is, for example, about 127 mm (5 inches). The interval between the first cylinder rods 5 is set to about 254 mm (10 inches), which is twice as large.

  When the thin plate workpiece W is placed on the workpiece lower fixing portion 3, the following procedure is performed.

  (I) First, as shown in FIG. 3, the tip 14a of the second rod 14 of the second cylinder rod 6 is positioned above the tip of the suction pad 13 of the adjacent first cylinder rod 5 (see FIG. 3). Positioning is performed at the position of the two-dot chain line (second rod positioning step).

  In this second rod positioning step, the tips 14a of all the second rods 14 may be positioned at positions higher than the tips of the suction pads 13, or some of the second rods of about 4 to 8 pieces. Only the tip 14a of 14 may be positioned in the upper position.

  (ii) Next, the thin plate workpiece W is placed on the tip 14a of the second rod 14 (mounting process). In this process, when the thin plate workpiece W is lowered onto the tips 14a of the plurality of second rods 14 using a crane or the like, the impact load from the thin plate workpiece W generated at that time can be received only by the second rod 14. it can.

  (iii) Next, the second rod 14 is lowered by the second height adjusting unit 15 (lowering step).

  (iv) Then, it is made to adsorb | suck to the adsorption pad 13 (adsorption process).

  In the above procedure, the impact of dropping when the thin workpiece W is mounted on the workpiece lower fixing portion 3 is received only by the second rod 14 having no suction pad, and the impact is applied to the suction pad 13 of the first cylinder rod 5. It can be prevented from transmitting. As a result, it is possible to reduce the occurrence of defects such as the suction position of the thin plate pad W in the suction pad 13 being shifted or the suction pad 13 being deteriorated and damaged.

  As shown in FIG. 2, the workpiece edge gripping portion 4 grips the edges E on the four sides of the outer periphery of the thin workpiece W. In the present embodiment, the four workpiece edge gripping portions 4 are arranged on the base 1 a of the processing apparatus 1 in a quadrangular shape so as to surround the workpiece lower fixing portion 3.

  As shown in FIG. 5, each workpiece edge gripping portion 4 includes a support base 40 and a plurality of gripping assemblies 43. Each gripping assembly 43 connects between the thin plate workpiece W and the support base 40. The support base 40 is disposed along any one of the four sides of the edge E of the thin plate workpiece W. The plurality of gripping assemblies 43 are arranged side by side along the side of the single support base 40 facing the thin plate workpiece W.

  As shown in FIG. 5, the grip assembly 43 includes a clamp 41, a receiving portion 42, a pair of support arms 44 and 45, and a pair of ball joints 46 and 47.

  As shown in FIGS. 5 to 6, the clamp 41 holds the thin plate workpiece W therebetween. The clamp 41 is formed with a slit 41a opened forward. The thin plate workpiece W is inserted into the slit 41a. Further, a screw hole 41b communicating with the slit 41a is formed on the upper surface of the clamp 41.

  The tip end surface 48a of the work attachment screw 48 screwed into the screw hole 41b is formed as a flat surface or a spherical surface so that it can contact the upper surface of the thin plate work W. Further, the lower surface 41c inside the slit 41a is formed by a flat surface so as to be in contact with the lower surface of the thin workpiece W. By screwing a work mounting screw 48 into the screw hole 41b, the distance between the front end surface 48a of the work mounting screw 48 and the lower surface 41c inside the slit 41a is reduced, and a thin plate is formed between the front end surface 48a and the lower surface 41c. By sandwiching the workpiece W, the thin plate workpiece W is held inside the slit 41. Here, the tip surface 48a is included in the concept of the upper surface contact portion of the present invention, and the lower surface 41c is included in the concept of the lower surface contact portion of the present invention.

  The receiving part 42 supports the clamp 41 via a preload mechanism 7 described later.

  The pair of support arms 44 and 45 have ball joint portions 44a and 45a at their tips. A receiving portion 42 is coupled to the ball joint portions 44a and 45a so as to be swingable in three axial directions.

  Further, the ball joints 46 and 47 shown in FIG. 5 are attached to the support base 40 along the height direction Z. The support arms 44 and 45 are attached to the support base 40 through these ball joints 46 and 47 so as to be swingable in three axial directions.

  In the present embodiment, each gripping assembly 43 is provided with a preload mechanism 7 for correcting the shape of the thin workpiece W. Since the thin plate workpiece W as described above is manufactured by the stretch forming method or the like, as shown in FIG. 3, there is a shape between the shape W0 in the drawing data at the time of design and the shape W1 of the actual thin plate workpiece. Therefore, even if the height of the suction pad 13 of each first cylinder rod 5 is adjusted based on the drawing data, a gap is generated between the thin plate workpiece W1 and the suction pad 13, and the thin plate There is a possibility that the workpiece W1 cannot be firmly fixed to the suction pad 13 by vacuum suction. Therefore, in order to solve such a problem, in the present embodiment, each gripping assembly 43 has a shape for correcting the shape of the thin plate workpiece W so that vacuum suction by the suction pad 13 can be satisfactorily performed. In order to reduce the deformation of the thin workpiece W when it is corrected and previously brought into contact with the tip 14a of the second rod 14 of the second cylinder rod 6 and receives a pressing force from the tool 71 during processing, the thin workpiece W A preload mechanism 7 for applying a compressive load (preload) in advance to the edge E is provided.

  The preload mechanism 7 of the present embodiment is a mechanism that can manually adjust the magnitude of the compressive load applied to the edge E of the thin plate workpiece W, as shown in FIGS. That is, the preload mechanism 7 shown in FIG. 6 includes a bolt 51, a spring 52, an inner nut 53, a clamp side flange 54, a receiving portion side flange 55, and an outer nut 56. Each has a pair.

  The clamp-side flange 54 is provided to protrude from the both side surfaces of the clamp 41 to the left and right. A through hole 54 a is formed in the clamp side flange 54.

  The receiving portion side flange 55 is provided so as to protrude right and left from both side surfaces of the receiving portion 42. A screw hole 55 a is formed in the receiving portion side flange 55 so as to penetrate the receiving portion side flange 55.

  The bolt 51 is inserted into the through hole 54 a of the clamp side flange 54 and screwed into the screw hole 55 a of the receiving portion side flange 55. The bolt 51 has a straight bar shape without a hexagonal head, and a screw is formed on the outer peripheral surface.

  The spring 52 is arranged between the clamp side flange 54 and the receiving part side flange 55 so that the bolt 51 is inserted into the spring 52.

  The inner nut 53 is coupled to the bolt 51 between the clamp side flange 54 and the receiving portion side flange 55, and is disposed adjacent to the spring 52.

  The outer nut 54 is coupled to the bolt 51 on the opposite side of the receiving side flange 55 with respect to the clamp side flange 54.

  Next, a procedure for fixing the edge E of the thin plate workpiece W using the workpiece edge gripping portion 4 will be described.

  First, the edge E of the thin plate workpiece W in a state of being fixed on the workpiece lower fixing portion 3 is gripped using the workpiece edge gripping portion 4.

  Specifically, as shown in FIG. 5, the clamp 41 is moved to the position of the edge E of the thin plate workpiece W, then the thin plate workpiece W is inserted into the slit 41 a of the clamp 41, and then the workpiece mounting screw 48 is attached. The thin plate workpiece W and the clamp 41 are connected by tightening. This operation is performed for all the clamps 41 surrounding the four edges E on the outer periphery of the thin workpiece W.

  At this time, the clamp 41 is supported by the support base 40 at a predetermined position and angle in a stationary state via the pair of support arms 44 and 45 and the ball joints 46 and 47.

  Next, with respect to each clamp 41, the preload mechanism 7 causes the edges E on both sides of the thin plate workpiece W to face toward the intermediate position in the width direction or the longitudinal direction of the thin plate workpiece W (more preferably, the thin plate workpiece W). Preload in the tangential direction of W). Specifically, first, the tightness of the outer nut 56 is adjusted to adjust the distance between the clamp side flange 54 and the receiving portion side flange 55. Next, the inner nut 53 is rotated to change the distance between the clamp-side flange 54 and the inner nut 53, thereby adjusting the degree of contraction of the spring 52. Thereby, the contraction degree of the spring 52 can be changed, and the compressive load which acts on the clamp 41, ie, a preload, can be adjusted.

  When the preload is applied to the edge E of the thin workpiece W, as shown in FIG. 3, a compressive load having the same magnitude is applied to the two opposite edges E of the thin workpiece W from the edges E on both sides. .

  Thus, by applying the preload to the edge E of the thin plate workpiece W inward of the thin plate workpiece W by the preload mechanism 7, the thin plate workpiece W is forcibly warped so as to protrude downward toward the suction pad 13. Thus, the adhesion between the thin plate workpiece W and the suction pad 13 can be improved, and the support rigidity of the thin plate workpiece W by the suction pad 13 can be improved.

(Data correction method)
As shown in FIG. 2, in the fixing device 2 of the present embodiment, the work lower fixing portion 3 having a form in which the first cylinder rod 5 having the suction pad 13 and the second cylinder rod 6 not having the suction pad are densely packed. In addition to supporting from below the thin plate workpiece W and firmly holding the four edges E of the thin plate workpiece W by the workpiece gripping portion 4, the thin plate workpiece W can be fixed at a predetermined position with high rigidity.

  However, since the thin workpiece W is easily deformed, it is difficult to fix the thin workpiece W in a shape as shown in the drawing data. For example, as shown in FIG. 10, there is a possibility that the placement position W0 of the thin plate workpiece on the NC machining data created based on the drawing data and the actual placement position W1 of the thin plate workpiece may deviate.

  Therefore, the present inventors have grasped the shape of the thin plate workpiece W fixed by the fixing device 2 of the present embodiment by measurement and correct the NC machining data, and the thin plate based on the corrected NC machining data. A processing method for the workpiece W is devised.

  That is, in the processing method of the thin plate workpiece W in the present embodiment, the shape of the thin plate workpiece W is changed by actually performing measurement while the thin plate workpiece W that may be deformed or stretched is fixed to the fixing device 2. The situation is grasped, and NC machining data is corrected based on the measurement result. After that, using the corrected NC processing data, processing such as thinning or pocket hole processing of the thin workpiece W is performed.

  Further, in this processing method, the thin plate workpiece W that is displaced or stretched is measured in a state of being fixed to the fixing device 2, and the processing of the thin plate workpiece W is performed by calculating the correction formula and correcting the processing portion according to the situation. I do.

  Next, measurement for calculating a correction formula for correcting NC machining data will be described.

1. Measurement for calculating the correction formula 1) First, after the thin plate workpiece W is fixed by the fixing device 2 described above, the positional deviation of the thin plate workpiece W with respect to the reference position defined by the NC machining data is measured.

  Specifically, as shown in FIG. 11, the reference points P11 to P14 on the surface of the actual thin plate work position W1 corresponding to the reference points P01 to P04 related to the thin plate work position W0 defined by the NC machining data. Is measured with a measurement probe, and the amount of displacement is calculated.

  The measurement probe is attached to the tool moving part 72 by exchanging with the tool 71 attached to the tool spindle 72e of the tool moving part 72 of the processing apparatus 1 shown in FIG. By moving the probe attached to the tool moving unit 72 in five axial directions (longitudinal direction X, width direction Y, height direction Z, and two rotation directions α and β), the amount of positional deviation of the thin plate workpiece W can be reduced. Measure.

  After measuring the amount of misalignment, a correction formula is created by selecting the following processing in consideration of the shape of the thin plate workpiece W and machining tolerance.

  2) As shown in FIG. 11, centering and rotation are performed by measuring the reference points P11 to P14 of the actual thin plate workpiece placement position W1 with a measurement probe.

  3) As shown in FIG. 12, within the range (arrangement position W1) in which the actual thin plate work is arranged, the blanking process determined in the arrangement position W0 of the thin plate work defined by the drawing data is scheduled to be performed. It is verified whether or not the entire processing range W2 that is the range is included. Here, it is only determined whether or not the entire processing range W2 is included, and data correction processing is not performed. For example, in the state of FIG. 12, since a part of the processing range W2 protrudes from the actual thin plate workpiece range (arrangement position W1), it is determined that the processing range W is not completely included.

  4) In addition to the above processes 1) to 3), a scaling coefficient is obtained from the result of measuring an actual thin plate workpiece W entirely by laser scanning. The scaling factor is the ratio of the actual dimension obtained by measuring the actual thin plate workpiece W by laser scanning to the design dimension in the drawing data at the time of design.

  From the results of the above processes 1) to 4), the correction formula is calculated by the following combination.

  That is, the correction formula is calculated by any combination of the above procedures 1) +2) +3) +4), 1) +3) +4), or 2) +3) +4).

  The correction formula obtained above is used as a correction formula for the entire thin plate workpiece W. Specifically, the correction formula obtained by the above method is a composite coordinate transformation matrix including at least one parameter of (position shift amount) or (centering / rotation) and a scaling factor. It becomes.

2. Next, the correction of the NC machining data in the processing part such as the thinning or pocket hole processing of the thin workpiece W, that is, the NC processing data in the processing part is performed by any one of the following methods 11) and 12). You can select and correct.

  11) A method of correcting each NC machining command point by the correction formula obtained as described above. That is, this is a method of correcting each command point independently, and does not take into account the order relationship of the command points (for example, the relationship between the start point and the end point).

  12) A method in which correction is performed in units of machining sites by the correction formula obtained as described above. That is, this is a method that does not change the shape of the processed part (for example, a rectangular parallelepiped pocket shape or the like).

  In both cases 11) and 12), the “correction allowance” can be set.

  In the case of the above 12) correction method in units of processing parts, “minimum remaining thickness” can be set as a correction condition. For example, with respect to the reference value indicating the original processing position H0 (the portion where the hollow pocket is formed and the rectangular pocket is formed) in the thin plate workpiece W shown in FIG. There is a case where the position shifts from the position H0 to the corrected machining position H1. In this case, in the corner portion C at the lower end of the corrected machining position H1, if the thin workpiece W is thinned, the thickness is reduced. There is a possibility that the design strength of the workpiece W may not be satisfied.

  Therefore, as shown in FIG. 15, the minimum remaining thickness θ satisfying the design strength can be ensured by performing the correction for shifting the processing portion H1 upward.

(Features of this embodiment)
(1)
As described above, in the thin plate workpiece W fixing device 2 of the present embodiment, the second cylinder rod 6 having a simple and compact structure having no suction pad between the first cylinder rods 5 provided with the suction pad 13. Is arranged, and the thin plate workpiece W is supported from below by both the first cylinder rod 5 and the second cylinder rod 6. The second cylinder rod 6 is smaller in dimension than the width Y1 of the first cylinder rod 5 with respect to the outer dimension (that is, the width Y2) in the width direction Y of the thin plate workpiece W. However, the occupied area becomes smaller. Thereby, the support interval of the thin plate workpiece W can be reduced.

  With this configuration, it is possible to support the thin plate workpiece W in a state where the support point interval of the thin plate workpiece W is shortened as compared with the fixing device including only the first cylinder rod 5 including the suction pad 13. The support rigidity of the workpiece W can be increased. As a result, even when the tool 71 is pressed against the thin workpiece W, the deflection of the thin workpiece W can be reduced, and the thin workpiece W can be processed with high accuracy.

(2)
Moreover, in the fixing device 2 of the present embodiment, the edge E of the thin plate workpiece W is gripped by the workpiece edge gripping portion 4, and therefore the vibration of the edge E of the thin plate workpiece W that occurs when the thin plate workpiece W is processed. Therefore, the thin workpiece W is not likely to come off the suction pad 13 and can be processed with higher accuracy.

(3)
Further, as in the present embodiment, even if the edge E of the thin plate workpiece W is greatly warped and inclined with respect to the pedestal 1a, the thin plate workpiece W is moved by the workpiece edge gripping portion 4 to the edge E of the thin plate workpiece W. By gripping the edge E of W, the vibration of the edge E of the thin plate workpiece W that occurs when the thin plate workpiece W is processed can be suppressed. As a result, there is no possibility that the thin workpiece W is detached from the suction pad 13, and processing can be performed with higher accuracy.

(4)
Further, as shown in FIG. 6, the workpiece edge gripping portion 4 of the present embodiment includes a tip end surface 48 a of a workpiece mounting screw 48 that is an upper surface abutting portion having a shape capable of abutting on the upper surface of the thin workpiece W, It has a lower surface 41c inside the slit 41a, which is a lower surface contact portion having a shape capable of contacting the lower surface of the thin plate workpiece W. By reducing the distance between the tip surface 48a and the lower surface 41c, it is possible to apply force from both the upper surface and the lower surface of the thin plate workpiece W and hold the thin plate workpiece W stably. .

(5)
Moreover, in the present embodiment, the edge E of the thin plate workpiece W is gripped by the workpiece edge gripping portion 4, and the width E or the longitudinal direction of the thin plate workpiece W is applied to the opposite edges E of the thin plate workpiece W by the preload mechanism 7. By applying the preload in the direction toward the intermediate position, the thin plate workpiece W in which a manufacturing shape error occurs can be pressed and fixed on the suction pad 13. Thereby, the clearance gap between the thin plate work W and the suction pad 13 can be eliminated, and the support rigidity of the thin plate work W can be improved. Further, by applying a preload to the thin plate workpiece W and bringing the thin plate workpiece W into contact with the tip 14a of the second rod 14 of the second cylinder rod 6 in advance, a pressing force is received from the tool 71 during processing. The deformation of the thin plate workpiece W can be reduced.

(6)
In the present embodiment, each of the first cylinder rod and the second cylinder rod is supported in an upright state by the pedestal portion 17a of the interval changing mechanism 8, while the drive portion 17b moves the pedestal portion 17a in a specific direction (that is, The distance between the first cylinder rod 5 and the second cylinder rod 6 in the width direction Y of the thin plate workpiece W is facilitated by moving along the width direction Y) of the thin plate workpiece W and stopping at a predetermined position. Can be changed.

  Further, the first cylinder rod 5 and the second cylinder placed on a certain width direction changing portion 17 are moved by moving the width direction changing portions 17 of the interval changing mechanism 8 in the longitudinal direction X by the linear drive portion 18b. The distance in the longitudinal direction X between the rod 6 and the first cylinder rod 5 and the second cylinder rod 6 placed on the adjacent width direction changing portion 17 can also be easily changed.

(7)
Further, in the present embodiment, the first height adjusting unit 12 on the first cylinder rod 5 side is a complicated and large mechanism for moving the suction pad 13 and the first rod 11 supporting the suction pad 13 up and down. The first rod 11 is movably supported in the up-and-down direction, the support portion 12c, the electric motor 12a, and the rotational driving force generated by the electric motor 12a is converted into a linear driving force in the up-and-down direction. And a power transmission unit 12b that transmits a driving force to the first rod. On the other hand, since the second height adjusting portion 15 on the second cylinder rod 6 side is structured to drive the second rod 14 up and down by the air cylinder 15a, it is more structured than the first height adjusting portion on the first cylinder rod 5 side. Can be further reduced in size. As a result, the second cylinder rod 6 can be brought closer to the first cylinder rod 5, and the support rigidity of the thin plate workpiece W can be further improved.

(8)
In the present embodiment, in the first cylinder rod 5, the suction pad 13 matches the shape of the thin plate workpiece W in order to perform vacuuming without causing air leakage between the thin plate workpiece W and the suction pad 13. In addition to the suction pad 13, a seating portion 16 having a spherical surface 16 a is provided at the tip of the first rod 11. In such a structure, regardless of the orientation and shape of the thin workpiece W, the spherical surface 16a of the seating part 16 can always make direct point contact with the lower surface of the thin workpiece W, and the normal direction of the lower surface of the thin workpiece W A force can be applied in the direction extending to Q (see FIG. 7) to support stably. Thereby, the thin plate workpiece W is rigidly supported by the first rod 11 via the seating portion 16. As a result, the rigidity of the portion that holds the thin plate workpiece W at the tip of the first cylinder rod 5 is improved as compared with the structure in which the thin plate workpiece W is held by the suction pad 13 alone, and the positioning accuracy and support rigidity of the thin plate workpiece W are improved. Will improve.

(9)
The thin plate workpiece processing apparatus 1 according to the present embodiment includes the fixing device 2 according to the above-described embodiment. Therefore, the support point interval of the thin plate workpiece W is compared with the first cylinder rod 5 only fixing device including the suction pads 13. Thus, the thin plate workpiece W can be supported at shorter intervals, and the support rigidity of the thin plate workpiece W can be increased. As a result, even when the tool 71 is pressed against the thin workpiece W, the deflection of the thin workpiece W can be reduced, and the thin workpiece W can be processed with high accuracy.

(Modification)
In the above-described embodiment, the second cylinder rod 6 is configured such that the outer dimension (width Y2) in the width direction Y of the thin workpiece W is smaller than the width Y1 of the first cylinder rod 5, thereby reducing the first cylinder. Although the occupation area is smaller than that of the rod 5, the present invention is not limited to this, and the second cylinder rod 6 is used for the external dimensions in other specific directions, for example, the longitudinal direction X of the thin workpiece W. It may be made smaller than one cylinder rod 5. Also in this case, the support interval of the thin plate workpiece W can be reduced.

  In the above embodiment, the bellows-like cylindrical pad has been described as an example of the suction pad 13. However, the present invention is not limited to this, and various shapes of suction pads can be adopted. Can do. For example, a hemispherical cup-shaped suction pad may be used, and in that case as well, the thin plate workpiece W can be supported in a state where the support point interval of the thin plate workpiece W is shortened, The support rigidity of the thin plate workpiece W can be increased.

DESCRIPTION OF SYMBOLS 1 Processing apparatus 2 Fixing apparatus 3 Work downward fixing part 4 Work edge holding part 5 1st cylinder rod 6 2nd cylinder rod 8 Space | interval change mechanism 11 1st rod 12 1st height adjustment part 13 Suction pad 14 2nd rod 15 1st 2 Height adjustment part 16 Seating part 71 Tool 72 Tool moving part W Thin plate workpiece

Claims (8)

A fixing device for fixing a thin plate workpiece in a predetermined position,
A plurality of first cylinder rods arranged so as to be arranged in a plurality of different specific directions on a horizontal reference plane and fixing the lower surface of the thin plate workpiece;
A plurality of second cylinder rods disposed between adjacent first cylinder rods and supporting the thin plate workpiece from below;
The first cylinder rod includes a first rod, a first height adjusting unit that changes a height of the first rod, and a suction pad that is provided at a tip of the first rod and sucks the thin workpiece. Have
The second cylinder rod has a second rod whose tip abuts against the lower surface of the thin workpiece, and a second height adjusting unit that changes the height of the second rod,
The first cylinder rod and the second cylinder rod are respectively arranged in a state of being set up vertically with respect to a horizontal reference plane,
The second cylinder rod is smaller than the first cylinder rod with respect to the external dimensions in the specific directions.
A thin plate workpiece fixing device characterized by that. A work edge gripping part for gripping the edge of the thin plate work;
The thin plate work fixing device according to claim 1. The thin plate workpiece has a shape whose edge is inclined with respect to the reference plane,
The work edge gripping part grips an edge of the thin plate work,
The thin plate workpiece fixing device according to claim 2. The work edge gripping portion has an upper surface contact portion having a shape capable of contacting the upper surface of the thin plate workpiece and a lower surface contact portion having a shape capable of contacting the lower surface of the thin plate workpiece,
The workpiece edge gripping portion clamps the thin plate workpiece between the upper surface contact portion and the lower surface contact portion by reducing a distance between the upper surface contact portion and the lower surface contact portion. Item 4. The thin plate workpiece fixing device according to Item 2 or 3. A pedestal that supports each of the first cylinder rod and the second cylinder rod in an upright state so as to be movable in at least the specific direction, and the pedestal is moved to a predetermined position along the specific direction and stopped. And further comprising a distance changing mechanism including a drive unit that changes the distance in the specific direction between the first cylinder rod and the second cylinder rod.
The thin plate workpiece fixing device according to any one of claims 1 to 4. The first height adjusting unit converts the rotational drive force generated by the support unit, the electric motor, and the electric motor that supports the first rod so as to be movable in the vertical direction into a linear drive force that is directed in the vertical direction. And a power transmission unit that transmits the linear driving force to the first rod,
The second height adjustment unit includes an air cylinder in which a lower end portion of the second rod is inserted so as to be able to appear and retract.
The thin plate workpiece fixing device according to any one of claims 1 to 5. The suction pad can be deformed according to the shape of the surface of the thin plate work contacting the tip, and can be closely attached to the lower surface of the thin plate work, and
The first cylinder rod further includes a seating portion provided at a tip of the first rod and having at least a part of a spherical surface capable of contacting the thin plate workpiece;
The seating portion is disposed inside the suction pad,
The thin plate work fixing device according to any one of claims 1 to 6. The thin plate work fixing device according to any one of claims 1 to 7,
A tool for performing surface processing of the thin plate workpiece fixed at a predetermined position by the fixing device;
A tool moving section for moving the tool on the thin plate workpiece;
With
Thin plate workpiece processing equipment.

Images