JP2013202623A - Press brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press brake equipped with an upper side detection means for detecting a vertical motion position of a ram relative to a side frame and a lower side detection means for detecting a displacement of a lower frame.SOLUTION: A press brake includes: upper and lower side detection means 15L, 15R:27L, 27R for detecting vertical displacements between a lower table 7 and an upper table 7 relative to left and right side frames 3L and 3R of the press brake; a pressurizing force detection means 47 for detecting pressurizing force on a workpiece by an upper die and a lower die; a distortion amount data table 51 in which the pressurizing force and a distortion amount of the side frame are related with each other and stored; a crowning data table 49 in which a crowning pressure of a crowning cylinder for performing crowning and a vertical displacement of the lower table relative to the side frame are related with each other and stored; a search means 53 for searching respective data tables; and a calculation means 55 for calculating an interval dimension between an upper die and a lower die by a search value searched by the search means 53 and a detection value detected by the upper side detection means.

Description

  The present invention relates to a press brake. More specifically, the present invention includes upper and lower detection means for individually detecting the vertical displacement of the upper and lower tables with respect to the side frame in the press brake. The present invention relates to a press brake provided with a calculation means for calculating the relative movement positions of upper and lower molds based on the detected value of the means.

  The press brake includes a lower table provided with a lower mold on the lower side of the left and right C-shaped side frames, and an upper table provided with an upper mold on the upper side of the side frame, One of the upper table and the lower table is provided as a movable table (ram) that can move up and down. When the plate-shaped workpiece is bent by the cooperation of the upper mold and the lower mold, the moving position of the moving table from the reference position in the vertical direction is detected by a position detector such as a linear scale. The relative movement positions of the upper and lower molds are detected (for example, see Patent Documents 1 and 2).

Japanese Patent No. 3552724 JP 2005-319489 A

  As is apparent from the descriptions in Patent Documents 1 and 2, as a configuration for detecting the moving position of the moving table in the press brake, when the upper table is a moving table, the lower part of the C-shaped detection plate is used as a side frame. A position detecting means such as a linear scale is provided on the upper free end side of the mounting, and the vertical movement position of the upper table is detected. When the lower table is a moving table, the configuration is opposite to that described above.

  That is, in the conventional configuration, one end side of the C-shaped detection plate that is long in the vertical direction is attached to the side frame, and the detection means is provided on the free end side of the detection plate. It was easy to receive, and further improvement was required.

  The present invention has been made in view of the problems as described above, and includes a lower table having a lower mold on the lower side of the left and right side frames, and an upper table having an upper mold on the upper side. A press brake having one of the tables as a movable table that is movable up and down, and a lower side detection means for detecting a vertical displacement of the lower table relative to the side frame, and An upper side detecting means for detecting a displacement in the vertical direction, a pressure detecting means for detecting a pressing force when the workpiece is bent by the cooperation of the upper mold and the lower mold, and the pressing force And a distortion amount data table in which the distortions of the side frames are stored in association with each other, and a crowning cylinder for crowning the lower table. A crowning data table that stores the awning pressure and the vertical displacement of the lower table relative to the side frame, a search unit that searches each data table, a search value searched by the search unit, and the upper part And a calculation means for calculating a distance dimension between the upper and lower molds based on a detection value detected by the side detection means.

  According to the present invention, the vertical displacement of the upper and lower tables with respect to the side frame is individually detected, and the relative movement position of the upper mold with respect to the lower mold is obtained by referring to the separately detected displacements. Therefore, for example, the configuration of the conventional detection plate as described above can be omitted. Therefore, the conventional problems as described above can be solved.

It is front explanatory drawing which showed notionally and schematically the structure of the press brake which concerns on embodiment of this invention. It is a perspective explanatory view showing the configuration of the lower side detection means. It is perspective explanatory drawing which shows the structure of an upper side detection means. It is explanatory drawing of a functional block diagram.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. A press brake 1 according to an embodiment of the present invention includes C as well as a general press brake, as conceptually and schematically shown in FIG. The left and right side frames 3L and 3R are provided, and a lower table 7 having a lower die (die) 5L is provided on the lower side of the side frames 3L and 3R. An upper table 9 having an upper die (punch) 5U is provided on the upper side of the side frames 3L and 3R. Note that the press brake has a configuration in which one of the upper and lower tables 9 and 7 is provided so as to be movable up and down, but in the present embodiment, the case where the upper table 9 moves up and down as a ram is illustrated.

  As is well known, the left and right ends of the lower table 7 are supported by swing support portions 11 provided on the left and right side frames 3L and 3R, and the front plate 13A has a form in which the lower table 7 is sandwiched from the front and rear. A crowning cylinder (not shown) is provided between the rear plate 13B (see FIG. 2) and the lower table 7. In other words, the lower table 7 is provided so that the central portion in the left-right direction can be curved upward.

  The upper table 9 is supported by the left and right side frames 3L and 3R so as to be movable up and down. The left and right side frames 3L and 3R are rotationally driven by, for example, a servo motor to move the upper table 9 up and down. Ram drive devices 13L and 13R such as a ball screw mechanism and a hydraulic cylinder are provided. Furthermore, upper side detection means 15L, 15R for detecting the vertical displacement (movement position) of the ram (upper table) 9 with respect to the left and right side frames 3L, 3R are provided above the left and right side frames 3L, 3R. Is provided.

  Since the left and right upper detection means 15L, 15R have the same configuration or a symmetrical configuration, only the right upper detection means 15R will be described, and the left upper detection means 15L will not be described. It will be omitted.

  The upper side detection means 15R is composed of a linear scale such as a magnescale, for example, and as shown in FIG. 3, a bracket 17 attached to the upper part of the side frame 3R is provided with a vertical base plate 19. . A linear scale body 21 is vertically attached to the base plate 19. The linear scale body 21 is provided with a detection head 23 that can freely move up and down, and the detection head 23 is integrally provided with a vertical follow-up member 25 that moves up and down following the vertical movement of the ram 9. It has been. The vertical follow-up member 25 is in contact with the upper surface of the ram 9 at an appropriate position.

  With the above configuration, when the ram 9 is moved up and down by the ram driving devices 13L and 13R, the detection head 23 is moved up and down integrally through the up and down following member 25. Therefore, the vertical movement position of the ram 9 relative to the vertical reference position of the left and right side frames 3L, 3R can be detected by the detection head 23.

  By the way, when the plate-shaped workpiece is bent by the upper die 5U attached to the upper table (ram) 9 and the lower die 5L attached to the lower table 7, the ram 9 is slightly curved so as to protrude upward. However, the lower table 7 tends to be slightly curved so as to protrude downward. Therefore, the lower table 7 is bent upward in a convex shape by the crowning cylinder so that the lower table 7 is bent upward along the curve of the ram 9.

  As described above, when the lower table 7 is curved upward, the central portion in the left-right direction of the lower table 7 is slightly displaced in the vertical direction with respect to the left and right side frames 3L, 3R. Therefore, in order to detect the vertical displacement of the lower table 7 relative to the left and right side frames 3L, 3R, lower side detection means 27L, 27R are provided on the lower side of the left and right side frames 3L, 3R. Since the left and right lower side detection means 27L and 27R have the same or symmetrical configuration, the configuration of one lower side detection means 27R will be described, and the description of the other lower side detection means 27L will be omitted.

  As shown in FIG. 2, the lower side detection means 27R (27L) includes a support member 29 whose base end side is fixed to the side frame 3R (3L). The distal end side of the support member 29 extends downward from the protruding portion 7P provided on the left and right ends of the lower table 7, and the protruding portion 7P is provided with a position detector 31 such as a linear potentiometer. ing. The tip of the contact 33 provided to the position detector 31 so as to be vertically movable and urged upward is in contact with the lower surface of the protruding portion 7P.

  Accordingly, when the lower table 7 is curved upward or downward with respect to a reference position where the upper surface of the lower table 7 is horizontal, the protruding portion 7P causes the swing support portion 11 to move. The position detector 31 can detect the displacement in the vertical direction of the protrusion 7P at this time. By the way, the dimension L1 from the swing center of the swing support part 11 to the position detector 31 is a preset dimension, and is from the bending position of the workpiece, for example, the central part of the lower table 7 in the left-right direction. If the dimension L2 to the center of swinging of the swinging support part 11 is known, the amount of vertical displacement at the bending position of the workpiece can be obtained from the dimension ratio.

  In other words, the lower side detection means 27L, 27R can detect the magnitude of the upward or downward curvature of the lower table 7, and can perform appropriate crowning when bending the workpiece. Is. That is, a data table in which the relationship between the detection value of the lower side detection means 27L and 27R and the crowning pressure applied to the crowning cylinder that performs crowning is experimentally obtained in advance and the detected value and the pressure of the crowning cylinder are associated with each other. By making it, an appropriate crowning pressure can be applied to the crowning cylinder, and appropriate crowning can be performed.

  That is, the control device 35 for controlling the press brake 1 is composed of a computer, and includes a CPU 37, a RAM 39, a ROM 41, an input means 43 and an output means 45 as schematically shown in FIG. Yes. The control device 35 is connected to the upper side detection means 15L and 15R and to the lower side detection means 27L and 27R. Further, a pressure detection means 47 is connected to the control device 35.

  The pressure detecting means 47 can detect the pressure by detecting the pressure of the hydraulic oil when the ram driving devices 13L and 13R are hydraulic cylinders, and detects the pressure by detecting the current value in the case of a servo motor or the like. It is something that can be done. In addition, since the structure which detects pressurizing force in a press brake is well-known, more detailed description of the pressurizing force detection means 47 is abbreviate | omitted.

  The control device 35 is provided with a crowning data table 49. The crowning data table 49 is used to perform proper crowning when bending a workpiece. The crowning data table 49 performs crowning of the detection values of the lower side detection means 27L and 27R and the lower table 7. The relationship with the pressure of the hydraulic oil applied to the crowning cylinder for this purpose is experimentally determined and stored in advance. Accordingly, by detecting the displacement of the lower table 7 relative to the side frames 3L, 3R by the lower side detection means 27L, 27R, proper crowning can be performed by the crowning cylinder.

  Further, the control device 35 is provided with a distortion amount data table 51. In this strain amount data table 51, the relationship between the pressurizing force at the time of bending the workpiece and the strain amount of the side frames 3L and 3R is experimentally obtained in advance and stored. Therefore, the amount of distortion of the side frames 3L and 3R can be corrected by detecting the applied pressure with the applied pressure detecting means 47 during bending of the workpiece. The control device 35 is provided with a search means 53 for searching the crowning data table 49 and the distortion amount data table 51 and a calculation means 55 for performing various calculations.

  In the configuration as described above, as shown in FIG. 1, after the upper and lower molds 5U and 5L are mounted at the center in the left-right direction of the upper and lower tables 9 and 7, and the workpiece W is positioned on the lower mold 5L, By driving the ram driving devices 13L and 13R and lowering the ram 9, the workpiece W can be bent by the upper and lower molds 5U and 5L. When the ram 9 is lowered as described above, the vertical movement position of the ram 9 from the reference position in the vertical direction with respect to the side frames 3L, 3R is detected by the upper side detection means 15L, 15R.

  When the workpiece W is bent by the upper and lower molds 5U and 5L, as is well known, the ram 9 tends to bend so that the upper part is convex, and the lower table 7 is convex downward. Tend to bend. And if the said curvature arises in the lower table 7, the displacement of the right-and-left both sides in the lower table 7 with respect to the side frames 3L and 3R will be detected by the lower side detection means 27L and 27R.

  When the detection values of the lower side detection means 27L and 27R are input to the control device 35, the search means 53 searches the crowning data table 49 and determines the pressure of the crowning cylinder (crowning pressure) corresponding to the detection value. Search for. Then, the crowning pressure retrieved from the crowning data table 49 by the retrieval means 53 is applied to the crowning cylinder, and the lower table 7 is crowned.

  Further, as described above, when the workpiece W is bent by the upper and lower molds 5U and 5L, the side frames 3L and 3R are strained upward. Therefore, when the applied pressure at the time of bending the workpiece W is detected by the applied pressure detection means 47 and this detected value is input to the control device 35, the search means 53 searches the distortion amount data table 51, and the detection is performed. A distortion amount corresponding to the value is obtained. Then, with respect to the detection values of the upper side detection means 15L and 15R, the distortion amount searched by the search means 53 is calculated and corrected by the calculation means 55 to calculate a correction value.

  By correcting the ram position with the obtained correction value, the distance between the upper and lower molds 5U, 5L, that is, the proximity position of the upper mold 5U with respect to the lower mold 5L can be accurately determined regardless of the distortion of the side frames 3L, 3R. It can be controlled and the workpiece W can be bent accurately.

  As already understood, the vertical movement position of the upper mold 5U with respect to the lower mold 5L is obtained by detecting the vertical movement position of the ram 9 with respect to the side frames 3L and 3R and correcting the distortion of the side frames 3L and 3R. Therefore, a detection plate that is long in the vertical direction is not necessary, and the influence of press brake vibration can be suppressed.

  Further, since the displacement of the left and right ends of the lower table 7 with respect to the side frames 3L and 3R is detected and the crowning pressure applied to the crowning cylinder is set, it corresponds to the applied pressure when the workpiece W is bent. Appropriate crowning can be performed, and accurate bending can be performed.

1 Press brake 3L, 3R Side frame 5U Upper die (punch)
5L Lower mold (die)
7 Lower table 9 Upper table (ram)
15L, 15R Upper side detection means 27L, 27R Lower side detection means 35 Controller 47 Pressure detection means 49 Crowning data table 51 Strain amount data table 53 Search means 55 Calculation means

Claims (1)

  A press brake having a lower table with a lower mold on the lower side of the left and right side frames, an upper table with an upper mold on the upper side, and one of the upper and lower tables as a movable table that can move up and down. A lower side detecting means for detecting a vertical displacement of the lower table relative to the side frame; an upper side detecting means for detecting a vertical displacement of the upper table relative to the side frame; Strain amount data for storing a pressurizing force detecting means for detecting a pressurizing force at the time of bending a workpiece by cooperation of the upper die and the lower die, and the pressurizing force and the strain amount of the side frame in association with each other. A table, a crowning pressure of a crowning cylinder for crowning the lower table, and a lower table for the side frame A crowning data table stored in association with the vertical displacement of each of the above, a search means for searching each of the data tables, a search value searched by the search means, and a detection value detected by the upper side detection means And a calculation means for calculating a distance between the upper and lower molds.

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