JPH07112636B2 - Plate bending machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for bending a workpiece of a plate material, and more specifically, to a guide post supporting an upper table and the upper table. The present invention relates to an apparatus for bending a plate material provided with an elastic body for pulling up a minute amount of looseness or the like at the connecting portion between the guide post and the eccentric shaft in the upward direction.

[Prior Art] A press brake is well known as a bending apparatus for bending a plate-shaped workpiece. In the conventional press brake, in the type where the upper table (ram) supporting the upper die moves up and down by the rotation of the eccentric shaft, when lowering the upper table and attempting to bend the workpiece, Cylinders or springs have been used as counterbalances to remove play at each connecting portion, for example, play between connecting rod and crankshaft or play between screws and ram.

[Problems to be Solved by the Invention] However, when a cylinder is used, an operation source is required,
When a spring is used, a long spring is required to cover the entire stroke due to the spring constant, and when positioning the upper frame near the bottom dead center, there is a problem that accurate positioning cannot be performed.

[Means for Solving the Problems] In view of the conventional problems as described above, according to the present invention, guide posts are provided on guide members provided on both sides of a machine base that supports a lower die so as to be movable up and down. Both sides of the upper table supporting the upper mold for bending the plate material on the lower mold are supported by the guide posts, and the lower parts of the guide posts are rotatably supported by the machine base. Each guide post is provided with an elastic body that is connected to the eccentric part of the eccentric shaft and that abuts on the upper table and urges it upwardly just before the upper die contacts the plate material on the lower die when the upper table descends. Is provided on the upper part of each of the guide members, and the strength of each elastic member is urged upward in the upper table and each of the guide posts to connect the guide posts with the eccentric shaft and each guide post. And the connection between the upper table and It is designed to have a small amount of backlash and backlash so that it can be moved upward.

[Embodiment] Referring to FIGS. 1 to 4, a bending apparatus 1 for bending a plate-shaped workpiece W has a box-like shape in which a lower die 3 is supported. The machine base 5 is provided, and guide posts 9R and 9L are respectively supported by guide members 7R and 7L provided on both left and right sides of the machine base 5 so as to be vertically movable in the vertical direction. An upper table (ram) 13 supporting an upper mold 11 for bending a workpiece W in cooperation with the lower mold 3.
The left and right sides of the are supported on the upper portions of the left and right guide posts 9R and 9L. Below the guide posts 9R and 9L,
Eccentric shaft (crank shaft) 15 rotatably supported on the machine base 5
Is appropriately connected to the eccentric portion 15E through connecting rods 17R and 17L.

With the above configuration, by appropriately rotating the eccentric shaft 15, the upper table 13 moves up and down via the guide posts 9R and 9L. Therefore, the workpiece W is placed on the lower mold 3.
Position, rotate the eccentric shaft 15 to rotate the upper table 13
By lowering and engaging the upper mold 11 with the lower mold 3,
Bending of the workpiece W can 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 later in detail, on the rear surface of the upper table 13, a reference line reading device 19 that optically detects a reference line such as a ruled line drawn on the workpiece W is mounted. Further, in order to accurately position the work piece W based on the reading result of the reference line reading device 19, a back gauge device 21 is provided at the rear (right side in FIG. 2) position of the lower mold 3. Has been.

Further, the bending apparatus 1 is provided with a control device including a display device (not shown) such as a CRT and a numerical control device (hereinafter, referred to as an NC device) for controlling each operating unit of the bending device 1. A plate 23 is provided, and a plate thickness detection device 25 that detects the plate thickness of the workpiece W to be processed and outputs the data to the NC device is provided.

More specifically, the machine base 5 includes left and right side plates 5R and 5L and side plates 5R and 5L.
Horizontally, the upper and lower sides of the R and 5L are supported on both left and right sides, and the upper is 5U.
Are formed into a substantially box shape by and reinforcing plates 5r are attached to the front and rear parts of the lower surface of the upper plate 5U.

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

In order to remove a minute gap in the bearing portion of the eccentric shaft 15,
The bearing device 27 is of special construction. That is, as shown in FIG. 5, an annular bearing holder 35 is integrally attached to one side plate 5R by bolts or the like, and the outer ring 37A of the bearing 37 is closely attached to the annular bearing holder 35. Is fitted to.

The inner peripheral surface of the inner ring 37B of the bearing 37 has the eccentric shaft 15
Is formed in a tapered hole corresponding to the tapered portion on the outer peripheral surface of the bush 39 closely fitted to the. A screw portion is formed at one end of the bush 39, and the inner ring is formed in this screw portion.
A nut member 41 that contacts the end surface of 37B is screwed. Although not shown in detail, an axial slit is formed from the other end of the bush 39 over an appropriate length so that the diameter can be expanded / contracted.

With the above configuration, by tightening the nut member 41, the fitting between the inner ring 37B of the bearing 37 and the bush 39 is brought into close contact, and the action of the taper portion brings the bush 39 and eccentric shaft 15 into close contact. Therefore, the eccentric shaft 15
The minute gap in the bearing portion of is removed.

The configuration of the bearing portion of the eccentric shaft 15 with respect to the other side plate 5L, the connecting portion of the eccentric portion 15E of the eccentric shaft 15 and the connecting rods 17R, 17L, and the connecting portion of the connecting rods 17R, 17L and the guide posts 9R, 9L are also included. Since the minute gap is removed by the similar structure, the same reference numerals are given to the constituent members having the same functions, and detailed description thereof will be omitted.

As can be understood from the above description, since the minute gaps in the rotating portion such as the bearing portion of the eccentric shaft 15 are removed, according to the present embodiment, the eccentric shaft 15 is appropriately rotated and stopped, and When the position of the table 13 is controlled, the position can be controlled with high accuracy.

In order to detect the top dead center and the bottom dead center of the eccentric shaft 15, as shown in FIG. 1, the eccentric shaft 15 has two pairs of dogs 43A and 43A.
B; 43C, 43D are attached, and two pairs of sensors 45A, 45B; 45C, 45D corresponding to the dogs 43A to 43D are attached to the machine base 5. One portion of the pair of dogs 43A, 43B slightly overlaps at a position showing the bottom dead center of the eccentric shaft 15, and the other pair of dogs 43C, 43D slightly at a position showing the top dead center. They overlap. Therefore,
When the sensors 45A and 45B corresponding to one of the dogs 43A and 43B both stop the eccentric shaft 15 in the detection operating state, the bottom dead center is stopped. On the contrary, the sensor 45C, 4 corresponding to the other dog 43C, 43D
When both 5D are in the detection operation state, the eccentric shaft 15 is located at the top dead center. That is, according to this embodiment, it is possible to accurately stop the eccentric shaft 15 at the top dead center and the bottom dead center.

Referring again to FIGS. 1 to 4, the guide post 9
The guide members 7R, 7L for guiding R, 9L up and down are formed in a cylindrical shape, and each guide member 7R, 7L is in a state in which the axis is substantially 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 9R, 9L are fitted without looseness, and the upper table supported on each guide post 9R, 9L is attached to the upper part of each guide member 7R, 7L. Ring members 47R, 47L that come into contact with 13 are provided so as to be vertically movable.

The ring members 47R, 47L are provided so as to contact the upper table 13 before the upper die 11 engages with the lower die 3 due to the lowering of the upper table 13, and the ring members 47R, 47L.
Between the guide members 7R, 7L are the guide posts 9R, 9L.
The elastic members 49R, 49L such as coil springs and disc springs surrounding and elastically urging the are always urged upward. The elastic members 49R and 49L are the upper table 13
The guide posts 9R, 9L, etc. in the upward direction to connect the guide posts 9R, 9L with the eccentric shaft 15 and the guide posts 9R, 9L.
It has the strength that can move the minute backlash and backlash of the connecting portion between the 9L and the upper table 13 upward.

With the above structure, when the upper table 13 is lowered to bend the workpiece W, the upper table 13 first contacts the ring member 47, and the elastic members 49R, 49L.
When the upper table 13 is positioned in the vicinity of the bottom dead center, it is possible to perform accurate positioning. .

In order to adjust the height position of the upper table 13 according to the change in the height of the upper and lower molds 11 and 3 and the change in the thickness of the work piece W, the left and right sides of the upper table 13 have the guide posts. It is mounted on 9R and 9L so that the vertical position can be adjusted.

More specifically, cylindrical rotating bodies 51R, 51L having screw parts 51S on the lower side are rotatably supported at the upper ends of the respective guide posts 9R, 9L. The chain sprockets 55R, 55L, 51R, 51L are rotated in synchronization with each other.
55L is attached integrally, and each chain spret 55R, 5
The endless chain 53 hung on 5L is the upper table.
It is tensioned by a tension sprocket 57 (see FIG. 4) which is properly attached to 13.

A driven gear 51G is integrally provided on one of the rotating bodies 51R as appropriate, and a drive gear 59 is meshed with the driven gear 51G. The drive gear 59 is attached to the output shaft of an adjusting 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 screw portions 51S of the rotary bodies 51R and 51L.

Therefore, when the adjustment motor 63 is appropriately driven to rotate,
Each chain sprocket 55R, 55L rotates synchronously via the chain 53. Therefore, the upper table 13 is composed of the rotating bodies 51R, 51
By synchronously rotating L, the position of each of the guide posts 9R and 9L is adjusted in the vertical direction.

In order to remove the backlash between the screw portion 51S of each rotating body 51R, 51L and each nut member 65R, 65L and adjust the vertical position of the upper table 13 accurately, each guide post 9R, 9L
A backlash removing device is provided between L and the upper table 13.

More specifically, as shown in FIG. 6, the guide post
A stepped portion 9RR with a large-diameter portion 9RL and a small-diameter portion 9RS on the upper part of 9R.
Is formed. The cylinder member 67 provided surrounding the stepped portion 9RR is fitted over the small diameter portion 9RS and the large diameter portion 9RL, and the fluid pressure chamber 69 is formed in the portion corresponding to the stepped portion 9RR. There is. The cylinder member 67 is the nut member 65.
The R and the upper table 13 are integrally held.

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 larger by the amount corresponding to the difference between the large diameter portion 9RL and the small diameter portion 9RS of the guide post 9R. It moves relatively to the upper side and moves the nut member 65R upward. Therefore, the backlash between the nut member 65R and the screw portion 51S of the rotating body 51R is removed.

As will be understood, when the lower die 3 and the upper die 11 are engaged with each other to perform the bending work of the workpiece W, the looseness of each connecting portion is removed and the backlash of the screwing portion is removed. Since the machining is performed in this state, the position control of the upper die 11 with respect to the lower die 3 can be performed with high precision, and the bending process with high precision can be performed.

The lower die 3 is a vertical surface that passes through the axis of the guide members 7R and 7L so that the guide posts 9R and 9L do not bend in the front-rear direction due to a reaction force or a reaction force when the workpiece W is bent. Is arranged between the guide members 7R and 7L, and is supported by the machine base 5 via a lower die holder 71. The upper die 11 is supported by the lower portion of the upper table 13 via the upper die holder 73, and is positioned vertically above the lower die 3.

Therefore, the reaction force when bending the workpiece W by the upper and lower molds 11 and 3 is
It will act perpendicularly to L and guide post 9R,
There is no such thing as bending 9L back and forth. Therefore, the upper and lower molds 11 and 3 can be accurately aligned, and accurate bending can be performed.

As described above, when the workpiece W is bent by lowering the upper table 13, in order to detect the lowering position and speed of the upper table 13, as shown in FIG. A rack 75 extending vertically is attached. A rotary pulse encoder 79 provided with a pinion 77 meshed with a rack 75 is provided on a part of the machine base 5.
Is installed. Therefore, when lowering the upper table 13 from the top dead center, the descent speed and the position can be detected by counting the number of pulses output from the pulse encoder 79 and appropriately performing arithmetic processing.

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. In the present embodiment, sensors 81 are provided on the left and right sides of the back surface of the upper table 13.
Equipped with R and 81L. Each sensor 81R, 81L is provided with a light beam irradiation for irradiating the upper surface of the workpiece W with a light beam such as a laser beam or a visible light, and also with a detection unit for detecting the presence or absence and the intensity of reflected light, such as a marking line. The bending position is detected. The detection unit of each of the sensors 81R and 81L can use, for example, an image sensor or various optical sensors. The detection data of each sensor 81R, 81L is used for positioning control of the back gauge device 21.

More specifically, the reference line reading device 19 is an upper table.
It is equipped with support members 85R and 85L that are supported by a guide rail 83 that is horizontally provided on the rear surface of 13 and whose position can be adjusted in the left-right direction. Each support member 85R and 85L is provided with each support member 85R and 85L. A fixing bolt that can be fixed to 83 is provided,
Tightening knobs 87R and 87L are provided at the ends of the fixing bolts, respectively. In addition, the lifting members 89R and 8R are attached to the support members 85R and 85L.
9L is provided so that it can move up and down, and each lifting member 89
Lifting cylinders 91R, 91L for lifting the R, 89L are provided. The sensors 81R and 81L are attached to the lower portions of the lifting members 89R and 89L.

With the above structure, each support member 85R, 85L
It is possible to appropriately position the workpieces W along the workpiece W, and it is possible to deal with workpieces W having various widths. Also, the lifting member 89
By lowering R, 89L, the sensor 81R, 81L can be detected close to the workpiece W, and the position of the reference line pre-scored on the workpiece W can be detected. Sensor 81R, 81
It is possible to avoid interference with L.

As shown in FIGS. 2 to 4, the back gauge device 21 for positioning the work piece W includes a pair of guide bases supported by the machine base 5 and extending in the front-rear direction.
93R and 93L are provided, and carriages 95R and 95L as moving members are movably supported on the guide bases 93R and 93L, respectively. In order to move the above carriages 95R and 95L back and forth, each carriage 9 is attached to each guide base 93R and 93L.
A general ball screw 97R, 97L screwed with a nut member (not shown) provided for the 5R, 95L and servo motors 99R, 99L for individually rotating the ball screws 97R, 97L are provided.

Operation handles 101R,
Elevating member 103R, 103L equipped with 101L and adjustable in vertical position by rotating operation handle 101R, 101L
Is provided. At the bottom of each lifting member 103R, 103L,
A dovetail groove is formed in the left-right direction that is orthogonal to the moving direction of the carriages 95R, 95L. Gauge holders 105R, 105L that extend horizontally in the left-right direction are positioned in the dovetail groove and adjusted in the left-right direction by general tightening. It is fixedly supported by attachments. Workpiece W is attached to each gauge holder 105R, 105L.
Abutment positioning members 107R, 107L for abutting against each other are supported so as to be positionally adjustable and fixed in the left-right direction, and a sensor for detecting contact of the workpiece W is provided on the facing surface of each abutment positioning member 107. 107S is installed respectively.

With the above configuration, by individually driving each servo motor 99R, 99L, it is possible to individually move and adjust the carriages 95R, 95L back and forth. Therefore, it is possible to cope with the case where the rear end edge of the workpiece W is inclined with respect to the left-right direction, and for example, even when the machining position of the workpiece W is inclined, one carriage is moved back and forth to correct. It is possible.

That is, according to this embodiment, the left and right abutting positioning members 107R and 107L are pre-positioned so that the predetermined machining position of the workpiece W is on the machining line defined by the upper and lower molds 11 and 3. After the workpiece W is positioned while holding the rear end edge of W in contact with each other, the left and right sensors 81R,
81L detects the marking lines of the workpiece W, and when the machining position of the workpiece W is inclined with respect to the machining positions of the upper and lower molds 11 and 3, one of them is determined according to the inclination amount. By driving the servo motors 99R, 99L of No. 1 to correct the position of one of the abutting positioning members 107R, 107L, the machining position of the workpiece W can be corrected in parallel to the machining position of the die, and accurately. It will be possible to position.

The plate thickness detection device 25 for detecting the plate thickness of the workpiece W
Is the upper plate 5U of the machine base 5, as shown in FIG.
It is mounted via a mounting block 109 mounted on the side surface of the. As shown in detail in FIGS. 7 and 8, a column 113 is rotatably supported by the mounting block 109 via a pivot 111, and an arc-shaped portion formed at the base of the column 113 is supported. A plurality of recesses 115A and 115B are formed. On the other hand, in the mounting block 109, a plunger 119, which is rotatably provided with a roller 117 that can be engaged with and disengaged from the recessed portions 115A and 115B, is slidably installed. Due to the action of the spring 123 mounted between the plunger 119 and the screw member 121 screwed to the mounting block 109, the plunger 119 is constantly pressed and biased toward the base of the column 113. Also, mounting block 109
Is provided with a stopper 125.

A base block 127 having an inverted L-shaped cross section is attached to the tip of the column 113. The protruding portion of the base block 127 has a semi-cylindrical support 12 for supporting the workpiece W.
9 is integrally attached, and an abutment block 131 for abutting the workpiece W is attached. Further, on the upper base block 127, a holder block 135, which is movably supported in the axial direction, is provided with a contactor 133 having a hemispherical contact portion facing the support 129 at one end thereof.
It is integrally attached to the projecting part of 27 with being spaced apart from each other. The holder block 135 includes a spindle 139 and the contactor 13
A measuring instrument 137 such as a dial gauge or a differential transformer, which comes into contact with the other end of 3 to detect the amount of movement, is mounted. The measuring device 137 is configured to output the measurement data to the NC device when the plate thickness of the workpiece W is measured. In the NC device, the minimum data of the measuring device 137 is held, The minimum value is configured to be recognized as the plate thickness of the workpiece W, and the control of each operating unit is appropriately performed based on the plate thickness data.

The holder block 135 includes a support 129 and a contact 13
A work piece W is inserted between the work piece 3 and the work piece 3, and a limit switch 141 that detects that the work piece W has come into contact with the protruding block 131 is attached, and a protection plate 145 that protects an operator 143 of the limit switch 141 swings. It is supported freely.

With the above-described configuration, the support 113 is appropriately rotated,
By selectively engaging the roller 117 with the recesses 115A and 115B, the column 113 can be held in a usable vertical state or a horizontal state when not in use. The column 113 is held vertically, and the work piece W is provided between the supporter 129 and the contactor 133.
When is inserted and abuts against the abutment block 131, the limit switch 141 is actuated, and the state becomes measurable. As described above, the work piece W is provided between the support member 129 and the contact member 133.
By inserting the
The thickness of the. At this time, when the workpiece W is swung up and down with the upper part of the support 129 as a fulcrum, the contact 13
3 moves up and down, and the measurement value of the measuring device 137 changes. The measured value is held every minute time, and the minimum value is determined as the plate thickness of the workpiece W. Based on the plate thickness, the position of the upper table 13 is controlled according to the bending angle and the like, and each necessary operating part is controlled.

[Effects of the Invention] As will be understood from the above description of the embodiments, the present invention is, in short, the guide members (7R, 7L) provided on both sides of the machine base (5) supporting the lower mold (3). Guide post (9R, 9
L) are each vertically movable, and both side portions of the upper table (13) supporting the upper die (11) for bending the plate material (W) on the lower die (3) are attached to the guide posts ( 9R, 9
L), the lower part of each guide post (9R, 9L) is rotatably supported by the machine base (5).
The upper table (13) is provided so as to be connected to the eccentric part (15E) of 5), and immediately before the upper die (11) comes into contact with the plate material (W) on the lower die (3) due to the lowering of the upper table (13). Enclosing the guide posts (9R, 9L) with elastic bodies (49R, 49L) that come into contact with and urge upwardly, the guide members (7R, 7L).
And the strength of each elastic body (49R, 49L) is set on the upper part of the upper table (13) and each guide post (9R, 9L) by urging the upper table (13) and each guide post (9R, 9L) upward. Eccentric shaft (1
5) The strength is such that minute backlash and backlash at the connecting part with the guide post (9R, 9L) and the upper table (13) can be moved upward.

As is apparent from the above configuration, according to the present invention, the upper die 11 is supported on the upper portions of the guide posts 9R, 9L movably supported by the guide members 7R, 7L provided on the machine base 5. A table 13 is supported and each guide post 9
The lower part of R, 9L is an eccentric shaft 15 rotatably supported on the machine base 5.
The eccentric part 15E is connected.

The elastic bodies 49R and 49L that contact the upper table 13 and urge the upper mold 11 upward before the upper mold 11 comes into contact with the plate material W on the lower mold 3 due to the lowering of the upper table 13 are formed by the respective guide posts 9.
R, 9L is provided on the upper part of each guide member 7R, 7L surrounding the R, 9L, and the strength of each elastic body 49R, 49L is sufficient to push up the total weight of the upper table 13 and each guide post 9R, 9L, etc. Since the upper table 13 and the guide posts 9R, 9L are urged upward by the elastic bodies 49R, 49L before the plate material W is processed by the upper mold 11 and the lower mold 3, the upper table 13 and the guide posts 9R, 9L are urged upward. Therefore, for example, minute play, backlash, etc. at the connecting portion between each guide post 9R, 9L and the eccentric shaft 15 and at the connecting portion between each guide post 9R, 9L and the upper table 13, etc. will be moved upward. The upper die 11 can be positioned with high accuracy near the bottom dead center.

In addition, since each elastic body 49R, 49L is surrounded by each guide post 9R, 9L, the upper table 13 and each guide post 9
When urging R and 9L upward, bending does not act on each guide post 9R and 9L, and each guide post 9R and 9L does not galling against each guide member 7R and 7L. It can always move up and down smoothly.

[Brief description of drawings]

FIG. 1 is a front view of a plate 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 cross-sectional view taken along the line VV in FIG. FIG. 6 is an enlarged sectional view taken along line VI-VI in FIG. FIG. 7 is an enlarged sectional view taken along the line VII-VII in FIG. Figure 8 shows VIII in Figure 1.
FIG. 7R, 7L …… Guide member 9R, 9L …… Guide post 13 …… Upper table 47R, 47L …… Ring member 49R, 49L …… Elastic member

Claims (1)

[Claims] 1. A guide post (9R, 9L) is attached to a guide member (7R, 7L) provided on both sides of a machine base (5) for supporting a lower mold (3).
The upper and lower dies (11) for bending the plate material (W) on the lower dies (3) are supported by the guide posts (9R, 9L)
It is installed on the bottom of each guide post (9R, 9L).
The upper table (1) is connected to an eccentric part (15E) of an eccentric shaft (15) rotatably supported by the machine base (5).
Immediately before the upper die (11) comes into contact with the plate material (W) on the lower die (3) due to the descent of 3), the elastic body (49R, 49L) that comes into contact with the upper table (13) and urges it upward is attached. Surrounding the guide posts (9R, 9L), the guide members (7R, 7L)
And the strength of each elastic body (49R, 49L) is set on the upper part of the upper table (13) and each guide post (9R, 9L) by urging the upper table (13) and each guide post (9R, 9L) upward. Eccentric shaft (1
5) It is characterized in that it is provided with such strength that it can pull up minute backlash and backlash in the connecting part with the guide post (9R, 9L) and the upper table (13). Plate bending equipment.