JP2004058147A - Device for formation by bending - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for formation by bending, a device capable of accurately and easily adjusting the optimum pressing force of a punch applied to a blank. <P>SOLUTION: In the bending formation device that forms a metallic plate into a prescribed shape by moving a punch along a cam curve, a prescribed rotary angle range for one rotation of cam 200 is at least provided with a first cam pressure angle range 213 and an adjacent second cam pressure angle range 214 which is connected to the first. The increment of operation quantity of the punch 201 is fixed in the range in which the pressure angle of the second cam is smaller than that of the first cam and also in the range of the second cam pressure angle. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to a bending apparatus capable of accurately adjusting an optimal pressing force of a punch applied to a material.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a belt-shaped plate material bending apparatus is configured to operate a punch by a cam to push and bend a material as described in Japanese Patent Application Laid-Open No. Hei 3-165941.
In the case of processing a strip 10 having a shape as shown in FIG. 1, for example, the forming apparatus in such a conventional apparatus fixes a metal strip 10 with a clamp 12 and a die 11 and fixes a punch 201 as shown in FIG. The bending process is performed by operating as shown.
[0003]
In general, when a pressure is released after a metal plate is deformed by applying a pressure to the metal plate, a springback phenomenon occurs in the band-shaped plate 10 to which the pressure is applied as shown in FIG. Therefore, the shape of the plate material 10 differs before and after the pressure is released.
Therefore, in general, in the bending process, the occurrence of the springback phenomenon is anticipated. For example, when a molded product 10 bent at 45 degrees as shown in FIG. 1 is obtained, the shapes of the punch and the die are set so that the plate material can be bent by 45 degrees or more. Use the designed one.
However, even when a punch and a die designed in such a manner are used, a spring-back phenomenon still occurs, and the bending result may not be a desired angle.
This is often due to the fact that, after the punch has been moved to a position where its linear movement is impeded by the die, the punching force necessary to reliably cause the plate to undergo a predetermined deformation is not applied to the plate. .
[0004]
Conventionally, in order to solve such a problem, before starting the bending process, the punch pressure, which most affects the bending process accuracy, is adjusted by adjusting the protrusion amount of the punch that moves linearly along the cam curved surface. Was.
However, even if a skilled worker adjusts the amount of punch protrusion until a desired bending result is obtained, it takes a short time of about half a day and a long time of about three days to improve the operation rate of the bending apparatus. It was a hindrance factor.
In addition, even if the cam is adjusted in this way, if the cam is once removed from the device for maintenance or other reasons, and then re-installed in the device, it takes another half day to obtain the same molding result as before the cam was removed. It requires a certain amount of cam mounting adjustment time.
Further, even if there is no change in the cam or the like, the result of the bending process is different each time the lot of the material used for the process is changed. Therefore, it is necessary to adjust the mounting of the cam each time.
[0005]
In order to solve this problem, a means for driving the rotation of a cam by a servomotor or the like and controlling the rotation has been proposed in Japanese Patent Application Laid-Open No. Hei 3-165941.
According to such a proposal, it is possible to easily reproduce the cam adjustment by quantitatively adjusting the rotation amount of the cam by numerical control and reuse the adjustment value, and to freely set the rotation amount of the cam. Is possible, it is possible to solve the difficulty of correcting the curved surface of the cam, which is a conventional problem, and even if the same cam is used, the cam rotation amount and the direction can be freely set to differ. It has become possible to easily carry out bending processing of products.
[0006]
[Problems to be solved by the invention]
However, in the above-mentioned proposal, although how to control the punch operation amount (projection amount) is proposed, it does not take into consideration how to perform the bending process with high accuracy.
For example, in the prior art, by rotating and controlling a cam 100 having a shape as shown in FIG. 4 with a servomotor, it is possible to control a punch operation amount 101 in proportion to the rotation of the cam as shown in FIG.
However, in the cam 100 having such a shape, since the punch protrusion increment value per unit rotation angle of the cam is large, the punch comes into contact with the material, and the desired bending result is obtained after the pressing and bending of the material is started. The pressure 102 applied to the punch while it is obtained has a characteristic of rapidly increasing as shown in FIG.
Therefore, in the cam shape having the pressing force characteristic as shown in FIG. 5, since the increment value of the pressing force with respect to the rotation per cam unit rotation angle is large, the adjustment region for adjusting the pressing force is narrow.
Therefore, it is difficult to precisely adjust the pressing force.
[0007]
Further, in the shape of the cam described in Japanese Patent Application Laid-Open No. Hei 3-165941, the design is made with emphasis on how to operate the punch, and the pressure angle of the cam (that is, the pressure between the cam and the punch) is determined. At the contact point, no design has been made that takes into account the cam push-out angle that pushes the punch against the workpiece.
However, the cam pressure angle is an important factor related to the punch pressure.
For example, when performing a punch operation using a cam having a large cam pressure angle, a large force (up to about 100 KN) is required to cause the punch to perform a predetermined work.
[0008]
Therefore, when a cam that does not consider minimizing the cam pressure angle is used in a bending apparatus, a servo motor having an unnecessarily large capacity is required for an operation source for operating the cam, and as a result, power consumption is reduced. This causes problems such as an increase in the price, an increase in the price of the device, an increase in its size, and a deterioration in controllability due to an increase in the motor inertia.
[0009]
[Object of the invention]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a bending apparatus capable of accurately and easily adjusting an optimum pressing force of a punch applied to a material.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, a bending apparatus of the present invention is a bending apparatus for forming a sheet metal into a predetermined shape by moving a punch according to a cam curve. Has at least a first cam pressure angle range and a second cam pressure angle range connected thereto, wherein the second cam pressure angle is smaller than the first cam pressure angle and the second cam pressure angle is smaller than the first cam pressure angle. The operation amount increment of the punch is constant in the pressure angle range.
With this configuration, the bending apparatus of the present invention can realize precise adjustment of the pressure applied to the workpiece, and can use a smaller capacity and lower inertia servomotor. It is possible to reduce the power, reduce the price of the device, reduce the size of the device, and improve controllability.
[0011]
According to another aspect of the present invention, there is provided a bending apparatus for forming a sheet metal into a predetermined shape by moving a punch in accordance with a cam curve. Is controlled in a multi-step manner from a large value to a small value to control the punch pressure accurately relating to the processing accuracy of the bending process.
Even with this configuration, the bending apparatus of the present invention can realize precise adjustment of the pressure applied to the workpiece.
[0012]
According to another aspect of the present invention, there is provided a bending apparatus including a cam rotation angle range in the first cam pressure angle range, a punch operation amount in the cam rotation angle range, and a cam rotation angle range in the second cam pressure angle range. The shape of the cam is designed based on the rotation angle range and the amount of punch operation in that range.
With this configuration, it is possible to easily design the cam shape of the bending apparatus of the present invention.
[0013]
Further, in order to solve the above-mentioned problem, the bending apparatus according to the present invention has a configuration in which the operation amount increment of the punch is constant in the first cam pressure angle range.
With this configuration, the bending apparatus of the present invention can more easily control the punch operation amount.
[0014]
Further, in order to solve the above problems, a bending apparatus of the present invention has a configuration in which the cam is rotated by a servomotor and positioned at a desired cam rotation angle.
According to this configuration, the bending apparatus of the present invention can easily adjust the amount of advance of the punch in the direction of the workpiece by positioning the cam at a desired rotation angle, and therefore, the same cam can be used. However, it is possible to implement various types of workpiece processing.
[0015]
【Example】
Hereinafter, an embodiment according to the present invention will be described with reference to an explanatory diagram, taking as an example a bending forming process of pressing and bending a band-shaped plate material 45 as shown in FIG.
[0016]
In order to carry out the bending process of the shape shown in FIG. 1, for example, as shown in FIG. 2, a device for performing the bending process is equipped with a punch 201, a die 11, a clamp 12 for fixing the strip-shaped plate material 10, and the like. .
This bending process is performed by fixing the band-shaped plate material 10 with the die 11 and the clamp 12 and operating the punch 201 in a predetermined direction.
[0017]
6 and 7 are operation principle diagrams of the punch 201 that operates at the time of the bending process and the cam 200 related to the operation of the punch, which will be described below.
The punch 201 receives at least a force from the spring 204 such that the cam contact end 202 of the punch always contacts the cam 200, and the punch 201 follows the shape of the cam 200 and rotates along the guide 203 by the rotation of the cam. It is pushed out and pulled back by the action of the spring 204.
The cam 200 is rotated by a servomotor 205 via a speed reducer 207, and the servomotor 205 is drive-controlled by a controller 206.
[0018]
The cam 200 of the present embodiment has a first cam pressure angle range 213 and a second cam pressure angle range 214, the second cam pressure angle is smaller than the first cam pressure angle, and the second cam pressure angle is smaller than the first cam pressure angle. The configuration is such that the amount of increase in the amount of advance of the punch in the direction of the workpiece is constant within the cam pressure angle range.
Here, the cam pressure angle is, as described above, an angle between the normal line and the movement direction of the punch at the contact point between the cam and the punch. The intersection angle α between a normal line perpendicular to a tangent passing through the contact point with the punch contact end 202 and the axis of the punch 201.
[0019]
The design of the cam 200 uses a table as shown in FIG. 8 and specifies the punch extrusion amount accompanying the rotation of the cam.
In the present embodiment, as shown in FIG. 8, the first cam (the ratio of the cam rotation to the punch extrusion amount (punch extrusion amount / cam rotation angle)) is a first predetermined value (inclination of the straight line 208). It has a pressure angle range 213 and a second cam pressure angle range 214 in which the ratio between the rotation of the cam and the amount of punching out is a second predetermined value (slope of the straight line 209) smaller than the first predetermined value. ing.
Thus, the straight line 208 and the straight line 209 each have a predetermined inclination.
That is, in the first and second cam pressure angle ranges 213 and 214, the punch pushing amount per unit angle of the cam is a predetermined value.
Therefore, each of the cam pressure angles in the first and second cam pressure angle ranges also becomes substantially a predetermined value.
In the first and second cam pressure angle ranges 213 and 214, the punch operation amounts (extrusion amounts) 210 and 211 and the corresponding cam rotation angles 213 and 214 are set in consideration of the following points.
[0020]
First, a total operation amount 212 required for the punch 201 to complete the bending processing and a total rotation angle range 215 of the cam 200 used for moving the punch 201 are set.
Next, a punch operation amount 211 within the second cam pressure angle range for adjusting the pressing force of the workpiece and a corresponding cam rotation angle range 214 are set.
The second cam pressure angle range 214 is mainly intended to precisely adjust the pressing force of the punch to the molding object.
[0021]
In order to achieve this object, the punch pressure 216 only needs to have a characteristic that does not rise sharply with the rotation of the cam. For example, a straight line 209 indicating the amount of punch protrusion with respect to the increment of the rotation angle of the cam 200 The second cam pressure angle range start cam rotation angle 217, the second cam pressure angle range end cam rotation angle 218, and the punch actuation amount (projection amount) 211 within the second cam pressure angle range so that the inclination of the second cam pressure angle range becomes smaller. Should be set.
[0022]
Further, in this embodiment, the purpose is to use a servomotor having a small capacity and a low inertia in the bending apparatus. However, in order to generate a necessary and sufficient pressing force for the bending processing by the servomotor, it is possible to use the servomotor. It is preferable to set the second cam pressure angle range 214 as wide as possible, and to minimize the cam pressure angle.
[0023]
Next, the punch operation amount 210 within the first cam pressure angle range obtained by subtracting the punch operation amount 211 within the second cam pressure angle range from the total operation amount 212, and the punch operation amount 210 within the second cam pressure angle range from the total rotation angle range 215. A cam rotation angle range 213 within the first cam pressure angle range obtained by subtracting the cam rotation angle range 214 is obtained.
The first cam pressure angle range punch operation amount 210 may be increased linearly as shown in FIG. 8, but may be increased along a parabolic or sinusoidal pattern. You may.
[0024]
Next, according to the relationship between the amount of punch operation and the cam rotation angle shown in FIG. 8, the shape of the cam 200 for operating the punch 201 is designed by a generally known manual method.
Note that the above-mentioned method is to divide the cam into arbitrary angles, for example, 5 degrees, calculate the amount of operation of the punch 201 from the center of the cam at each of the divided angles from the table in FIG. That is, the shape of the cam 200 is designed by plotting the amount of operation of the punch 201 for each of the points on the drawing and connecting the plotted points smoothly.
[0025]
Further, as in the above-described method, the shape of the cam 200 may be designed by performing plotting on CAD without plotting points on the drawing and connecting the plotted points smoothly with a spline curve or the like.
[0026]
In addition, at least the first cam pressure angle range punch operation amount 210, the second cam pressure angle range punch operation amount 211, the total operation amount 212, the total rotation angle range 215, and the second cam pressure angle range start cam rotation The shape of the cam 200 may be automatically designed by inputting the angle 217 and the end cam rotation angle 218 of the second cam pressure angle range into a computer.
[0027]
Further, the designed cam is manufactured, and at least a cam 200, a punch 201, a servo motor 205 serving as a rotation drive source of the cam, a control device 206 for controlling the rotation of the servo motor, and a speed reducer 207 shown in FIG. It is incorporated into the operating device 219 having the above configuration, and the operating device is further mounted on a bending apparatus as shown in FIG.
The cam 200 may be connected to the servomotor 205 for rotation, but preferably, connected via a speed reducer 207 to further increase the resolution of the pressing force adjustment and to bend with a smaller capacity servomotor. A cam operating force sufficient for processing may be generated.
[0028]
Further, by controlling the rotation angle of the cam 200 by the servo motor 205 and the controller 206, for example, as shown in FIG. By variously changing, it is also possible to produce works having different shapes.
[0029]
Further, as shown in FIG. 11, a punching amount per unit cam rotation (punching amount / cam rotation angle) is set to, for example, four (four straight lines 401 and 402) at 0 ° which is the rotation start reference 400 of the cam 405. , 403, and 404), ie, a cam motor 405 shown in FIG. 12 is designed and manufactured to set four ranges of cam pressure angles, and the cam 405 is rotated forward and backward. By combining the control device with the control device, it is possible to process a wider variety of product shapes with a single cam.
[0030]
Next, a description will be given of an embodiment of the adjustment of the pressure applied to the work 10 performed before the work 10 is bent by the operation shown in FIG. 2 according to the punch operation pattern shown in FIG.
The pressing force adjustment is performed by first rotating the cam 200 to the second cam pressure angle range start cam rotation angle 217 which is set as the start position of the second cam pressure angle range 214, thereby obtaining a belt-shaped plate member as shown in FIG. (Work) 10 is pressed and bent.
Subsequently, the cam 200 is further rotated by inputting rotation amount data to the servo motor controller 206 from an external input device such as a generally used manual pulse generator or a numerical input device (not shown).
According to the rotation of the cam 200, the punch 201 moves to a position where the operation (projection) is hindered by the die 11, and the pressing force assumed to be necessary to obtain a desired bending process result by further rotating the cam 200. Is added to the belt-shaped plate material 10.
[0031]
Next, the pressure is once released, and the result of the bending of the band-shaped plate 10 is inspected.
The inspection may be performed manually using a measuring instrument such as a caliper, or may be automatically measured and inspected by combining an image processing apparatus, a computer, and software.
[0032]
As a result of the inspection, when the strip-shaped plate member 10 is not bent to a desired angle, the rotation amount data is input to the servo motor controller 206 so as to further rotate the cam 200 in order to increase the pressing force applied to the punch 201. If the belt-shaped plate member 10 is bent to a desired angle or more, the data of the rotation amount is input to the servo motor controller 206 so as to reduce the rotation angle of the cam 200 in order to reduce the pressing force.
The above operation is repeatedly performed until the desired result is obtained by bending the band-shaped plate material 10, and the finally obtained rotation angle of the cam 200 is stored in the servo motor controller 206, and the cam 200 is always By applying software for issuing a stored command value to the servomotor to rotate to the rotation angle to the servomotor, a bending process that satisfies a desired processing accuracy is stably performed.
[0033]
The repetitive work may be performed manually, but preferably may be performed automatically by combining the image processing device or the like with software.
Further, instead of obtaining a predetermined cam rotation angle by the above-mentioned repetitive operation, a punch set in a desired at least bent shape, the material of the band-shaped plate material 10, the shape of the punch and the die, and the first and second cam pressure angle ranges. The desired rotation angle of the cam 200 may be estimated from the operation amount and the cam rotation angle range, and the rotation angle may be set in the servo motor controller 206. Further, the estimation of the rotation angle is performed by combining a computer and software. May be.
[0034]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a bending apparatus capable of accurately and easily adjusting an optimum pressing force of a punch applied to a material.
[Brief description of the drawings]
FIG. 1 is an example of a molded product obtained by bending a band-shaped plate material.
FIG. 2 is an explanatory view of a bending operation of a band-shaped plate material.
FIG. 3 is an explanatory diagram of a springback phenomenon.
FIG. 4 is an example of a cam shape used in a conventional bending apparatus.
FIG. 5 is an explanatory diagram of a punch operation amount with respect to a cam rotation angle and a change in a pressing force applied to a strip-shaped plate material with respect to a cam rotation angle when a punch is operated by combining the cam and the servo motor shown in FIG.
FIG. 6 is a simple explanatory view of the operating principle of the punch.
FIG. 7 is another simple explanatory view of the operating principle of the punch.
FIG. 8 is a setting example of a cam pressure angle range in the embodiment.
FIG. 9 is a setting example of a cam rotation angle corresponding to a pressing force adjustment position in the embodiment.
FIG. 10 is a configuration example of a bending apparatus in an embodiment.
FIG. 11 is a setting example of two or more cam pressure angle ranges in the embodiment.
FIG. 12 is an example of a cam shape having two or more cam pressure angle ranges in the embodiment.
[Explanation of symbols]
10 Strip-shaped plate (work)
11 Die 12 Clamp 100, 200, 405 Cam 201 Punch 205 Servo motor 206 Servo motor controller 207 Reduction gear 213 First cam pressure angle range 214 Second cam pressure angle range 210 Punch operation within first cam pressure angle range Amount 211 Punch operation amount 212 within second cam pressure angle range 212 Total operation amount 215 Total rotation angle range 216 Punch pressure 401 Indicates the amount of change in punch protrusion in the first cam pressure angle range.
402 shows the amount of change in punch protrusion in the second cam pressure angle range.
403 shows the amount of change in punch protrusion in the third cam pressure angle range.
404 shows the amount of change in punch protrusion in the fourth cam pressure angle range.

Claims (5)

In a bending apparatus for forming a sheet metal into a predetermined shape by moving a punch in accordance with a cam curve, at least a first cam pressure angle range and a first cam pressure angle range connected to the predetermined rotation angle range of one rotation of the cam. A second cam pressure angle range, wherein the second cam pressure angle is smaller than the first cam pressure angle, and the punch operation amount increment is constant in the second cam pressure angle range. A bending apparatus. In a bending machine for forming a sheet metal into a predetermined shape by moving a punch in accordance with a cam curve, the bending is performed by controlling the increment of the amount of operation of the punch from a large value to a small value in multiple steps and controlling the increment. A bending apparatus characterized by precisely performing a punching pressure adjustment relating to a processing accuracy of a forming process. The cam shape based on the cam rotation angle range of the first cam pressure angle range and the amount of punch operation in the range, and the cam rotation angle range of the second cam pressure angle range and the amount of punch operation in the range The bending apparatus according to claim 1, wherein is designed. 2. The bending apparatus according to claim 1, wherein the operation amount increment of the punch is constant in the first cam pressure angle range. 2. The bending apparatus according to claim 1, wherein the cam is rotated by a servomotor and positioned at a desired cam rotation angle.

Images