JPS62230425A - Sheet bending machine - Google Patents

Abstract

PURPOSE:To minimize a whole constituting and to maintain a displacing direction of an upper table (ram) caused by a pressure at time of working in the vertical direction by supporting both the sides of the upper table freely adjustably for keeping its position and height with respect to each guide post and removing a backlash of respective connecting parts. CONSTITUTION:The upper table 13 is moved vertically through the guide posts 9R, 9L by rotating an eccentric shaft 15. In case of lowering the table 13 to bend a work piece W, at first, as the upper table 13 is abutted on a ring parts 47 to put the backlash of each connecting part, etc., aside by working elastic the operation of members 49R, 49L, so an accurate positioning is performed. Furthermore, when an adjusting mortar 63 is driven to rotate chain sprockets 55R, 55L synchronously through a chain 53, cylindrical rotating bodies 51R, 51L provided with screw thread part 51S are rotated synchronously, the upper table 13 is adjusted in the position in vertical directions for the guide posts 9R, 9L.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an apparatus for bending a plate workpiece, and more specifically, to an apparatus for bending a plate workpiece, and more specifically, for controlling the vertical movement of an upper table (ram) supporting an upper die. The present invention relates to a plate material bending device which is provided with a drive source on the lower side and a guide post supporting an upper table that is movable up and down.

[Technical Background of the Invention and Problems Therewith] A press brake is well known as a bending device for bending a plate-shaped workpiece. In conventional press brakes, the upper table (ram) that supports the upper mold moves up and down, and a drive source such as a hydraulic cylinder or an eccentric shaft (crankshaft) is placed at the top of the C-shaped frame. Generally, the upper table is moved up and down by a drive source.

Therefore, in the past, the problem of increasing the overall structure in the vertical direction and the bending of the C-shaped frame toward the opening of the gap due to the reaction force of the pressurizing force during bending of the workpiece were caused by the upper There is a problem in that the positioning accuracy of the mold is affected, for example, it is difficult to perform highly accurate positioning during air bending.

Further, the positioning of a plate-shaped workpiece with respect to a mold provided in a press brake may be performed by using a back gauge or by visually positioning the score lines of the workpiece relative to the mold.

In the former case, there are problems such as the positioning accuracy of the workpiece depending on the edge finishing accuracy of the workpiece. Also,
In the latter case, there are problems such as large individual errors by the operator.

[Purpose of the Invention] The present invention was invented in view of the above-mentioned conventional problems, and its first purpose is to reduce the overall structure and reduce the pressure caused by the pressing force during bending of the workpiece. It is an object of the present invention to provide an apparatus for bending a sheet material of 100 degrees Celsius, which can maintain the displacement direction of an upper table (ram) in the vertical direction.

A second object of the present invention is to provide a novel bending device that can accurately match the bending position of a workpiece.

[Summary of the Invention] In order to achieve the above objects, the present invention provides guide posts that are vertically movably supported on guide members provided on both sides of a machine base that supports the lower die. Both sides of an upper table supporting an upper mold cooperating with the mold are supported by the guide posts, and the lower part of each guide post is connected to an eccentric part of an eccentric shaft rotatably supported by the machine base. It is what it is.

In addition, in order to accurately position the workpiece,
Standard I that optically detects the processing reference line corresponding to the bending processing position of the plate material! J reading devices are provided near both sides of the upper table so as to be movable up and down.

[Embodiments of the Invention] Referring to FIGS. 1 to 4, a bending device 1 for bending a plate-shaped workpiece W is generally a box supporting a lower die 3. The machine 5 is equipped with a machine stand 5 having a shape, and guide posts 9R and 9m are supported by guide members 7R and 7m provided on both left and right sides of the machine stand 5, respectively, so as to be vertically movable. The left and right sides of the upper table (ram) 13, which supports the upper die 11 for bending the workpiece W with the lower die 3 and the cooperation Or L, are supported by the upper parts of the left and right guide posts 9R and 9L. There is. The lower portions of each of the guide posts 9R, 9L are appropriately connected to an eccentric portion 15E of an eccentric shaft (crankshaft) 15 rotatably supported on the machine base 5 via connecting rods 17R, 17L.

With the above configuration, by appropriately rotating the eccentric shaft 15, the upper table 13 can be moved up and down via the guide posts 9R and 9L. Therefore, after positioning the workpiece W on the lower mold 3, the eccentric shaft 15 is rotated to lower the upper table 13, and the upper mold 11 is engaged with the lower mold 3, thereby bending the workpiece W. Processing may be performed.

In order to detect the positioning state of the workpiece W when bending the workpiece W as described above,
As will be described in detail later, a reference line reading device 19 that optically detects reference lines such as score lines drawn on the workpiece W is attached to the rear surface of the upper table 13. In addition, in order to accurately position the workpiece W based on the reading result of the reference line reading device 19, a back gauge device 21 is installed at a position behind the lower mold 3 (the right mold in FIG. 2).
is provided. Further, the bending device 1 includes a CR, for example, in order to control each operating section of the bending device 1.
A control panel 23 is equipped with a display device such as T (not shown) and a numerical control device (hereinafter referred to as an NC device), and also detects the thickness of the workpiece W to be machined and displays the data. plate thickness detection device 2 that outputs the information to the NC device;
5 is provided.

More specifically, the machine stand 5 has left and right side plates 5R.

5L, and a horizontal upper plate 5U whose left and right sides are supported on the front upper part of the side plates 5R and 5L, and has a roughly box-like structure, and reinforcing plates 5r are attached to the front and rear of the lower surface of the upper plate 5U, respectively. It is.

The eccentric shaft 15 is located below the upper plate 5U of the machine base 5, and its left and right ends are rotatably supported by the side plates 5R and 5L via a bearing device 27. A driven gear 29 is integrally attached to one end of the eccentric shaft 15 via a key or a nut, and a driving gear 31 meshes with this driven gear 29. The drive gear 31 is connected to the side plate 5R.
It is attached to the output shaft of a servo motor 33 attached to. Therefore, by appropriately rotating and stopping the servo motor 33 under the control of the NC device, the lowering speed and stopping position of the upper table 13 can be appropriately controlled.

In order to eliminate a minute gap in the bearing portion of the eccentric shaft 15, the bearing device 27 has a special configuration. That is, as shown in FIG. 5, an annular bearing holder 35 is mounted on one side plate 5R. The outer ring 3 of the bearing 37 is integrally attached to this annular bearing holder 35.
7Δ indicates a close fit.

The inner circumferential surface of the inner ring 37B of the bearing 37 is formed into a tapered hole corresponding to a portion of the tapered outer circumferential surface of the bushing 39 closely fitted to the eccentric shaft 15. A threaded portion is formed at one end of the bush 39, and a nut member 41 that abuts the end surface of the inner ring 37B is screwed into this threaded portion.

Although detailed illustrations are omitted, a slit in the axial direction is formed from the other end of the bushing 39 over an appropriate length, and the bushing 39 is configured to expand and contract in diameter to form a rod.

With the above configuration, by tightening the nut member 41, the inner ring 37B of the bearing 37 and the bushing 39 are tightly fitted, and the bushing 39 and the eccentric shaft 15 are also tightly fitted due to the action of a portion of the taper. . Therefore, the minute gap in the bearing portion of the eccentric shaft 15 is eliminated.

Furthermore, the structure of the bearing portion of the eccentric shaft 15 relative to the other side plate 5L, the connecting portion between the eccentric portion 15E of the eccentric shaft 15 and the connecting rods 17R, 17L, and the connecting portion between the connecting rods 17R, 17L and the guide posts 9R, 9L are also shown. Since micro gaps are removed using a similar configuration, the same 11! Components that perform functions will be designated by the same reference numerals and detailed explanations will be omitted.

As can be understood from the above explanation, since minute gaps in rotating parts such as the bearing part of the eccentric shaft 15 are removed,
According to this embodiment, when controlling the position of the upper table 13 by appropriately rotating and stopping the eccentric shaft 15, highly accurate position control is possible.

In order to detect the top dead center and bottom dead center of the eccentric shaft 15, two pairs of dogs 4 are provided on the eccentric shaft 15, as shown in FIG.
3A, 43B: 43G, 43D are installed, and two pairs of sensors 45 corresponding to each dog 43A to 43D are installed on the machine base 5.
A, 45B: 45G, 45D are installed. The above pair of dogs 43A.

One portion of the eccentric shaft 15 slightly overlaps at the bottom dead center position, and the other pair of dogs 43G, 43[) slightly overlap at the top dead center position of the eccentric shaft 15. Therefore, one dog 4
When the eccentric shaft 15 is stopped while the sensors 45A and 45B corresponding to the sensors 3A and 43B are both in the detection operating state, the eccentric shaft 15 is stopped at the bottom dead center.

Conversely, the sensor 45 corresponding to the other dog 43C, 43D
When C and 45D are both in the detection operating state, the eccentric shaft 15
will be located at top dead center. In other words, according to this embodiment, the eccentric shaft 15 can be stopped at the top dead center and the bottom dead center with high precision.

Referring again to FIGS. 1 to 4, the guide post 9
The guide members 7R, 7L that guide R, 9L up and down are formed in a cylindrical shape, and the axis of each guide member 7R, 7L is approximately aligned with the vertical plane passing through the axis of the eccentric shaft 15. It is arranged. Each guide member 7R, 7L and each guide post 9R99L are fitted together without play, and the upper part of each guide member 7R, 7L is fitted with each guide post 9R.
.

Ring members 47R and 47L are provided which are movable up and down, and which come into contact with the upper table 13 supported by the upper table 9L.

Each ring member 47R, 47m is provided so as to come into contact with the upper table 13 before the upper mold 11 engages with the lower mold 3 due to the lowering of the upper table 13, and each ring member 47R, 47L is provided with a guide. It is always urged upward by elastic members 49R and 49L that are elastically mounted between members 7R and 7m.

The elastic members 49R, 49L have sufficient strength to push up the total ff1ffi of the upper table 13, guide posts 9R, 91, etc.

With the above configuration, when the upper table 13 is lowered to bend the workpiece W, the upper table 13 first comes into contact with the ring member 47 and the elastic member 4
When the upper table 13 is relatively pushed up by the action of 9R and 49L, and the looseness of each connecting portion is moved in one direction, and the upper table 13 is positioned near the bottom dead center,
This allows for highly accurate positioning.

In order to adjust the height position of the upper table 13 in response to changes in the height of the upper and lower molds 11 and 3 and changes in the thickness of the workpiece W, the left and right sides of the upper table 13 are provided with the guide posts. It is attached to 9R and 9L so that its vertical position can be adjusted freely.

More specifically, at the upper end of each guide post 9R, 9L, a cylindrical rotating body 51 is provided with a threaded portion 518 on the lower side.
R and 51L are rotatably supported. Chain brockets 55R, 55L are integrally attached to each rotating body 51R, 51L so as to rotate in synchronization with each other, and an endless chino 53, which is hung around each chain brocket 55R, 55L, is attached to the upper table. 13 by means of a tension sprocket 57 (see FIG. 4) appropriately attached to the tension sprocket 57 (see FIG. 4). A driven gear 51G is appropriately provided integrally with one of the rotating bodies 51R, and this driven gear 51G
The drive gear 59 is in mesh with the drive gear 59. The drive gear 59 is attached to the output shaft of an adjustment motor 63 supported by the upper table 13 via a bracket 61. Nut members 65R and 65L attached to both sides of the upper table 13 are screwed into the threaded portions 518 of the respective rotating bodies 51R and 51L.

Therefore, when the adjusting motor 63 is driven to rotate appropriately, the chain sprockets 55R and 55L are rotated synchronously via the chain sprocket 53. Therefore, the upper table 13 rotates each of the rotating bodies 51R, 51L in synchronization to rotate each guide post 9R.

The position will be adjusted in the vertical direction with respect to 9L.

In order to accurately adjust the vertical position of the upper table 13 by eliminating backlash between the screw portion 518 of each rotary body 51R, 51L and each nut member 65R, 65L,
A backlash removal device is provided between each guide post 9R, 9L and the upper table 13.

More specifically, as shown in FIG. 6, a stepped portion 9RR consisting of a large diameter portion 9RL and a small diameter portion 9R8 is formed at the upper portion of the guide post 9R. A cylinder member 67 provided around the stepped portion 9RR is fitted across the small diameter portion 9R8 and the large diameter portion 9RL, and a fluid pressure chamber 69 is formed in the portion corresponding to the stepped portion 9RR. It is. The cylinder member 67 is held integrally between the nut member 67R and the upper daple 13.

In the above configuration, when the working fluid is supplied to the fluid pressure chamber 69, the fluid pressure acts on the stepped portion 9RR of the guide post 9R and also acts on the inner surface of the cylinder member 67. Therefore, the upper and lower pressure receiving areas of the cylinder member 67 are the large diameter portion 9RL and the small diameter portion 9R of the guide post 9R.
Since the upper side is larger by an amount corresponding to the difference from 8, the cylinder member 67 moves upward relative to the guide post 9R, and moves the nut member 65R upward. Therefore, backlash between the nut member 65R and the threaded portion 518 of the rotating body 51R is eliminated.

As already understood, when the lower mold 3 and the upper mold 11 are engaged to bend the workpiece W, play in each connecting portion is removed and backlash in the threaded portion is also eliminated. The processing is performed in this state, and the position of the upper die 11 relative to the lower die 3 can be controlled with high precision, and the bending process can be performed with high precision.

In order to prevent the respective guide posts 9R, 9L from being bent in the front-rear direction due to drag or reaction force during the bending process of the workpiece W, the lower die 3 is attached to the guide members 7R, 7L.
Each guide member 7R substantially coincides with a vertical plane passing through the axis of the guide member 7R.
, 7L, and is supported by the machine stand 5 via a lower mold holder 71. Further, the upper mold 11 is supported by the lower part of the upper table 13 via the upper mold holder 73 and is located vertically above the lower mold 3.

Therefore, the reaction force when the workpiece W is bent by the upper and lower molds 11, 3 acts perpendicularly to each guide post 9R, 9L, causing the guide post 9R, 9L to bend back and forth. There's nothing I can do about it.

Therefore, the upper and lower molds 11.3 are accurately aligned,
Accurate bending can be performed.

As mentioned above, when lowering the upper table 13 to bend the workpiece W, the upper table 13
In order to detect the descending position and speed of the machine, a rack 75 extending vertically is attached to the upper table 13, as shown in FIG. Further, a rotary pulse encoder 79 having a pinion 77 meshed with a rack 75 is mounted on a part of the machine base 5. Therefore, when the upper table 13 is lowered from the top dead center, the lowering speed and position can be detected by counting the number of pulses output from the pulse encoder 79 and performing appropriate arithmetic processing.

Referring to FIGS. 2 to 4, the reference line reading device 19
is for optically detecting the reference line of the workpiece W prior to bending the workpiece W, and in this embodiment, sensors 81R and 81L are provided on both left and right sides of the back surface of the upper table 13. There is. Each sensor 81R, 81L
is equipped with a light irradiation unit that irradiates the upper surface of the workpiece W with a light beam such as a laser beam or visible light, and a detection unit that detects the presence or absence and strength of reflected light. It is used to detect.

The detection section of each sensor 81R, 81L can use, for example, an image sensor or various optical sensors. The detection data of each sensor 81R, 81L is the back gauge device 2.
1 is used for positioning control.

More specifically, the reference line reading device 19 is supported by a guide rail 83 provided horizontally on the back surface of the upper table 13, and is supported by support members 85R and 85L whose position can be adjusted in the left and right direction.
Each supporting member 85R, 85L is provided with a fixing bolt that can fix each supporting member 85R, 85m to the guide rail 83, and a tightening knob 87R, 87L is provided at the end of the fixing bolt, respectively. is provided. Further, each of the support members 85R and 85L is provided with lifting members 89R and 89L that can be moved up and down, and each of the lifting and lowering members 89R.
, 89L, lifting cylinders 91R, 91
L is provided. And each of the elevating members 89R, 8
The respective sensors 81R and 81L are attached to the lower part of 9L.

With the above configuration, each of the support members 85R and 85L can be appropriately positioned along the guide rail 83, and workpieces W of various widths can be handled. Further, by lowering the elevating members 89R and 89L, the position of the reference line pre-marked on the workpiece W can be detected in a state where the sensors 81R and 81R are brought close to the workpiece W, and the position of the reference line pre-marked on the workpiece W can be detected. : It is possible to avoid interference between the workpiece W and the sensors 81R, 81R.

The back gauge device 21 for positioning the workpiece W includes a pair of guide bases 93R and 93L supported by the machine stand 5 and extending in the front-rear direction, as shown in FIGS. 2 to 4. Each guide base 93R
, 93L each have a carriage 95 as a moving member.
R and 95L are supported so as to be movable back and forth. In order to move the carriages 95R, 95m back and forth, each guide base 93R, 93L has general ball screws 97R, 97L screwed together with a nut member (not shown) provided on each carriage 95R, 95L, and each ball screw 97R. ,97m
Servo motors 99R and 99L are provided to rotate the servo motors 99R and 99L individually.

The carriages 95R, 95m are provided with operating handles IC) 1R, 101L, respectively, and elevating members 103R, 103L whose vertical positions can be adjusted by rotating the operating handles 101R, 101L. Each lifting member 103R.

A dovetail groove in the left and right direction orthogonal to the moving direction of the carriages 95R and 95L is formed in the lower part of the carriage 103L, and gauge holders 105R and 105L extending horizontally in the left and right direction are positioned in this dovetail groove in the left and right direction. It is fixedly supported by adjustable and conventional fasteners. Each gauge holder 105R.

Abutment positioning members 107R and 107L for abutting the workpiece W are supported on the abutment positioning member 105L so as to be adjustable and fixed in the left and right directions, respectively. A sensor 107S that detects contact between the two is connected to each other.

. With the above configuration, by individually driving each servo motor 99R, 99L, each carriage 95R, 95L can be individually adjusted to move back and forth. therefore,
It is possible to cope with the case where the rear end edge of the workpiece W is inclined in the left-right direction, and even if the processing position of the workpiece W is inclined, for example, it can be corrected by moving one carriage back and forth. It can be done.

That is, according to this embodiment, the left and right abutting positioning members 107R, 107L are positioned in advance so that the planned processing position of the workpiece W is on the processing line defined by the upper and lower molds 11, 3. After positioning the workpiece W by holding the rear edge of the workpiece W in contact with each other, the left and right sensors 81R and 81L in the reference II reading device 19 are used to measure the score lines, etc. of the workpiece W. When it is detected that the processing position of the workpiece W is inclined with respect to the processing position of the upper and lower molds 11 and 3, one of the servo motors 99R and 99L is driven according to the amount of inclination. By correcting the position of one of the abutment positioning members 107R and 107m, the processing position of the workpiece W can be corrected to be parallel to the processing position of the mold, and the position can be accurately positioned.

The plate thickness detection device V! detects the plate thickness of the workpiece W! 1
25 is attached via a mounting block 109 attached to the side surface of the upper plate 5U of the machine base 5, as shown in FIG. As shown in detail in FIGS. 7 and 8, a column 113 is supported on the mounting block 109 via a pivot 111 so that it can be raised and lowered, and an arcuate portion formed at the base of the column 113 is attached to the mounting block 109. Multiple recesses 115A, 115B
is formed. On the other hand, a plunger 119 rotatably equipped with a roller 117 that can be freely engaged with and disengaged from the recesses 115A and 115B is slidably housed inside the mounting block 109. This plunger 119 and mounting block 1
The plunger 119 is always pressed toward the base of the support column 113 by the action of a spring 123 that is elastically mounted between the screw member 121 screwed into the plunger 119. Further, the mounting block 109 is provided with a stopper 125.

A base block 127 having an inverted cross section is attached to the tip of the support column 113. This base block 12
A cylindrical support 129 for supporting the workpiece W is integrally attached to the protrusion 7, and an abutting block 131 for abutting the workpiece W is attached thereto. Further, on the upper base block 127, a holder block 135 that supports a contact 133 having a flat vein-shaped contact portion facing the support 129 at one end so as to be movable in the axial direction is attached to the protruding portion of the base block 127. They are installed integrally with opposite sides apart. The holder block 135 is equipped with a measurement Ia 137 such as a diamond gauge or a differential transformer that detects the amount of movement by bringing the spindle 139 into contact with the other end of the contactor 133. This measuring device 137 is configured to output the measurement data to the NC device when measuring the thickness of the workpiece W, and the NC device holds the minimum data of the measuring device 137. The minimum value is recognized as the plate thickness of the workpiece W, and each operating section is appropriately controlled based on the plate thickness data.

A limit switch 141 is attached to the holder block 135 for detecting that the workpiece W is inserted between the supporter 129 and the contactor 133 and comes into contact with the abutment block 131, and a limit switch 141 is attached to the holder block 135. A protection plate 145 that protects the actuator 143 of the switch 141 is swingably supported.

With the above configuration, by appropriately rotating the support 113 and selectively engaging the rollers 117 in the recesses 115A and 115B, the support 113 can be placed in a vertical state where it can be used or in a horizontal state when not in use. can be maintained. Pillar 1
13 in a vertical state, the supporter 129 and the contactor 13
Insert the workpiece W between the abutting block 13 and
1, the limit switch 141 is activated and becomes ready for measurement. As described above, since the workpiece W is inserted between the supporter 129 and the contactor 133, the measuring device 137 detects the thickness of the workpiece W. At this time, when the workpiece W is swung up and down using the upper part of the supporter 129 as a fulcrum, the contactor 133 moves up and down, and the measured value of the measuring device 137 changes. The measured value is held every minute time, and the minimum value is set to the workpiece W.
The thickness of the plate is determined as follows. Based on the plate thickness, the position of the upper table 13 is controlled according to the bending angle, etc., and each necessary operating section is controlled.

[Effects of the Invention] As can be understood from the description of the embodiments above, the gist of the present invention is as described in the claims, so the overall structure can be made compact and the workpiece can be folded. The alignment of the upper and lower molds during bending can be maintained accurately, and bending can be performed with high precision. In addition, the bending position of the workpiece can be quickly and accurately positioned relative to the bending position of the mold.
This improves work efficiency and enables accurate machining.

[Brief explanation of drawings]

FIG. 1 is a front view of the sheet material bending apparatus. 2 is a right side view of the same, FIG. 3 is a rear view of the same, and FIG. 4 is a plan view of the same. FIG. 5 is an enlarged sectional view taken along the line V-■ in FIG. 2. Figure 6 shows Vl-Vl in Figure 2.
It is an enlarged sectional view along the line. FIG. 7 is an enlarged sectional view taken along the line ■-■ in FIG. 1. FIG. 8 is an enlarged view in the direction of the ■ arrow in FIG. 3...Lower die, 5...Machine base, 7R, 7m...Guide members 9R, 9L...Guide post, 11...Upper die,
13... Upper table, 15... Eccentric shaft, 19...
・Reference line reader porridge-) Figure 6 Figure 109 12':1 115B Medicine 8z

Claims (5)

[Claims] (1) Guide posts are supported on guide members provided on both sides of the machine base that supports the lower die, allowing vertical movement,
Both sides of the upper table supporting the upper mold cooperating with the lower mold are supported by each of the guide posts, and the lower part of each guide post is an eccentric part of an eccentric shaft rotatably supported by the machine base. A sheet material bending device characterized by being connected to. (2) The plate material bending apparatus according to claim 1, wherein both sides of the upper table are supported by respective guide posts so that the height position thereof can be freely adjusted. (3) The lower die and the upper die are arranged between the guide posts so as to substantially coincide with a vertical plane including the axis of each guide post, as set forth in claim 1. plate bending processing equipment. (4) Guide posts are supported on guide members provided on both sides of the machine base that supports the lower die so as to be movable up and down, and
Both sides of an upper table supporting an upper mold cooperating with the lower mold are supported by the guide posts, and the lower part of each guide post is connected to an eccentric portion of an eccentric shaft rotatably supported on a machine base. A sheet material bending apparatus characterized in that a reference line reading device for optically detecting a processing reference line of a sheet material to be bent is provided near both sides of the upper table so as to be movable up and down. . (5) Claim 4, characterized in that each reference line reading device is positionally adjustable in directions toward and away from each other.
The sheet material bending processing device described in 2.