JP2023151929A - bending machine - Google Patents

Abstract

To set a distance between a punch and a die as a target distance when bending, and to improve passage accuracy.SOLUTION: A bending machine 1 comprises: an eccentric shaft 20 of which a midship part 20C, that is decentered by only a prescribed eccentricity ΔE from a rotary shaft Ar when rotating around the rotary shaft Ar along a cross direction Y, is vertically moved and presses a pressure reception face 5P of a stationery table 5; and a cylindrical eccentric ring 30 which is provided on at least one support plate 11 (or 13) of a support plate 11 on a front side and a support plate 13 on a rear side, and adjusts a position of the midship part 20C of the eccentric shaft 20 with respect to the pressure reception face 5P of the stationery table 5. The eccentric ring 30 includes an outer peripheral part 31 which is supported by a through hole 17F (or 17B) provided at least one support plate 11 (or 13), and an inner peripheral part 32 which so supports the eccentric shaft 20 as to be rotatable around the rotary shaft Ar, and a center 32C of the inner peripheral part 32 is eccentric with respect to a center 31C of the outer peripheral part 31.SELECTED DRAWING: Figure 4

Description

The present invention relates to a bending machine.

BACKGROUND ART Bending machines equipped with a crowning mechanism are conventionally known (for example, Patent Document 1). The crowning mechanism included in the bending machine described in Patent Document 1 includes an eccentric shaft that rotates to deform the upper table or the lower table (fixed table) in a convex direction, and a servo motor that rotates the eccentric shaft. It is equipped with

The center of the eccentric shaft that constitutes the crowning mechanism is eccentric from the center of rotation by a predetermined amount of eccentricity, and the front and rear parts of the eccentric shaft are horizontally supported via bearings by support plates placed at the front and rear of the fixed table. It is supported by and can rotate freely. The eccentric shaft is connected to a servo motor attached to the rear surface of the support plate on the rear side of the fixed table, and is rotated by driving of the servo motor. As the central portion moves up and down due to the rotation of the eccentric shaft, the pressure receiving surface of the fixed table that receives the force from the central portion is vertically displaced (deformed). Due to the action of such an eccentric shaft, the fixed table curves up and down, so that the distance between the punch and the die is kept constant during bending, and the passing accuracy is improved.

Japanese Patent Application Publication No. 2000-343127

However, when assembling a bending machine, due to cumulative tolerances of multiple parts that make up the bending machine, the positional relationship between the eccentric shaft and the pressure receiving surface of the fixed table that receives the force from the eccentric shaft is at the ideal position. There may be no relationship. Therefore, the stroke amount (vertical movement amount of the central part of the eccentric shaft) and speed of the eccentric shaft relative to the pressure receiving surface of the fixed table do not match the target values during bending, and the distance between the punch and the die does not match the target distance. There are cases.

In addition, it is possible to reduce the cumulative tolerance by reducing the dimensional tolerance of each component that makes up the bending machine, and to reduce the dimensional tolerance between the eccentric shaft and the pressure receiving surface of the fixed table, but it is possible to reduce the dimensional tolerance to 0. It's difficult to do.

One aspect of the present invention is a bending machine that includes a movable table that moves in the vertical direction and a fixed table that is disposed at a position facing the movable table in the vertical direction. It is inserted into the front support plate and the rear support plate, and the through holes that penetrate in the front and back direction provided in the front and rear support plates, respectively, and rotate around the rotation axis along the front and rear direction. When rotated, the central part that is eccentric from the rotating shaft by a predetermined eccentric amount moves up and down and presses the pressure receiving surface of the fixed table, thereby bending the fixed table. a cylindrical eccentric ring provided on at least one support plate to adjust the position of the central part of the eccentric shaft with respect to the pressure receiving surface of the fixed table, the eccentric ring having a through hole provided on at least one support plate; The center of the inner circumferential portion is eccentric with respect to the center of the outer circumferential portion.

According to the bending machine of one aspect of the present invention, the cylindrical eccentric ring that adjusts the position of the central part of the eccentric shaft with respect to the pressure receiving surface of the fixed table is attached to at least one of the front support plate and the rear support plate. installed on the support plate. The eccentric ring includes an outer peripheral part supported by a through hole provided in at least one support plate, and an inner peripheral part that supports the eccentric shaft rotatably around the rotation axis, and the center of the inner peripheral part is It is eccentric to the center of the outer periphery. Since the center of the inner circumference of the eccentric ring is eccentric with respect to the center of the outer circumference, the position of the center of the eccentric shaft relative to the pressure receiving surface of the fixed table can be adjusted. Therefore, by adjusting the position of the central portion of the eccentric shaft relative to the pressure receiving surface of the fixed table, the vertical movement amount and speed of the central portion of the eccentric shaft relative to the pressure receiving surface of the fixed table can be adjusted to the target value during bending. be able to.

According to one aspect of the present invention, the interval between the punch and the die during bending can be set to a target interval, and the passing accuracy can be improved.

FIG. 1 is an explanatory diagram schematically showing the configuration of a bending machine according to this embodiment. FIG. 2 is a diagram showing the configuration of the fixed table. FIG. 3 is a diagram showing the external shape of the crowning mechanism. FIG. 4 is a sectional view taken along the cutting line AA shown in FIG. 2, and is an explanatory diagram showing the configuration of the crowning mechanism. FIG. 5 is an explanatory diagram schematically showing the configuration of the eccentric ring. FIG. 6 is a diagram showing a notch provided in the eccentric ring. FIG. 7 is an explanatory diagram schematically showing the action of the eccentric ring.

Hereinafter, a bending machine according to this embodiment will be described with reference to the drawings.

FIG. 1 is an explanatory diagram schematically showing the configuration of a bending machine according to this embodiment. FIG. 2 is a diagram showing the configuration of a fixed table. FIG. 4 is a sectional view taken along the cutting line AA shown in FIG. 2, and is an explanatory diagram showing the configuration of the crowning mechanism. FIG. 5 is an explanatory diagram schematically showing the configuration of the eccentric ring. The configuration of the bending machine according to this embodiment will be described below with reference to FIGS. 1, 2, 4, and 5.

In the following description, the left-right direction X, the front-back direction Y, and the up-down direction Z are used to define the bending machine. The left-right direction X and the front-back direction Y correspond to two directions perpendicular to each other in the horizontal direction, and the up-down direction Z corresponds to the vertical direction. However, these directions are only used for convenience in order to explain the bending machine in this embodiment.

The bending machine 1 according to the present embodiment includes a movable table 7 that moves in the vertical direction Z, and a fixed table 5 that is disposed at a position facing the movable table 7 in the vertical direction Z. The bending machine 1 is provided with a front support plate 11 and a rear support plate 13, which are arranged on both sides of the fixed table 5 in the front-rear direction Y, and a front support plate 11 and a rear support plate 13, respectively. When inserted into the through holes 17F and 17B penetrating in the front-rear direction Y, and rotated around the rotation axis Ar along the front-rear direction Y, the central portion 20C, which is eccentric from the rotation axis Ar by a predetermined eccentric amount ΔE, moves up and down. An eccentric shaft 20 that curves the fixed table 5 by pressing the pressure receiving surface 5P of the fixed table 5, and an eccentric shaft 20 provided on at least one support plate 11 (or 13) of the front support plate 11 and the rear support plate 13, It includes a cylindrical eccentric ring 30 that adjusts the position of the central portion 20C of the eccentric shaft 20 with respect to the pressure receiving surface 5P of the fixed table 5. The eccentric ring 30 has an outer peripheral part 31 supported by a through hole 17F (or 17B) provided in at least one support plate 11 (or 13), and an inner part that supports the eccentric shaft 20 rotatably around the rotation axis Ar. A center 32C of the inner circumference 32 is eccentric with respect to a center 31C of the outer circumference 31.

The detailed configuration of the bending machine 1 will be described below. The bending machine 1 is a processing machine that performs a bending process on a plate-shaped work such as a sheet metal, for example. The bending machine 1 is, for example, a press brake, and pressurizes the workpiece between an upper die 8 such as a punch and a lower die 6 such as a die by moving the movable table 7 in the vertical direction Z. Perform bending.

The bending machine 1 includes a fixed table 5, a movable table 7, left and right actuators such as hydraulic cylinders 9L and 9R, crowning mechanisms 19L and 19R, and a control device 80. A servo motor may be used as the actuator instead of a hydraulic cylinder.

The bending machine 1 includes left and right side frames 3L and 3R that are spaced apart and opposed to each other in the left-right direction X. The movable table 7 extends in the left-right direction X, and is supported by the front upper portions of the side frames 3L and 3R. The movable table 7 is configured to be movable in the vertical direction Z. The fixed table 5 extends in the left-right direction X, and is supported by the front lower portions of the side frames 3L and 3R.

An upper mold holder that removably holds the upper mold 8 is provided below the movable table 7. A holder groove for inserting the base of the upper mold 8 is formed along the left-right direction X in the upper mold holder. The upper die holder has a hydraulic clamp that fixes the upper die 8 to the movable table 7. Note that the clamp may be of an electric type, a mechanical type, or a pneumatic type instead of a hydraulic type.

A lower mold holder that removably holds the lower mold 6 is provided above the fixed table 5. A holder groove for inserting the base of the lower mold 6 is formed along the left-right direction X in the lower mold holder. The lower die holder has a hydraulic clamp that fixes the lower die 6 to the fixed table 5. Note that the clamp may be of an electric type, a mechanical type, or a pneumatic type instead of a hydraulic type.

The left and right hydraulic cylinders 9L and 9R are provided at the left and right upper portions of the side frames 3L and 3R, respectively. The left and right hydraulic cylinders 9L and 9R function as a lifting mechanism that moves the movable table 7 in the vertical direction Z.

A front support plate 11 and a rear support plate 13 are provided on both sides of the fixed table 5 in the longitudinal direction Y, respectively. The front support plate 11 and the rear support plate 13 are integrally attached to the fixed table 5 via left and right pivot shafts 15L and 15R penetrating in the front-rear direction Y.

Left and right through holes 17L and 17R, which pass through the front support plate 11 and the rear support plate 13 in the front-rear direction Y, are located at symmetrical positions on the left and right sides with respect to the center position of the fixed table 5 in the left-right direction X. It is provided. The left and right through-hole portions 17L and 17R are each configured by a through-hole 17F provided in the front support plate 11 and a through-hole 17B provided in the rear support plate 13 (FIG. 4). Crowning mechanisms 19L and 19R are provided inside the left and right through holes 17L and 17R. Note that the shapes of the left and right through holes 17L and 17R are the same, and the configurations of the left and right crowning mechanisms 19L and 19R are the same. Therefore, in the following description of the crowning mechanism, it will simply be referred to as the through hole portion 17 and the crowning mechanism 19.

FIG. 3 is a diagram showing the external shape of the crowning mechanism. FIG. 6 is a diagram showing a notch provided in the eccentric ring. The configuration of the crowning mechanism 19 will be described below with reference to FIGS. 3 to 6. As shown in FIG. 4, the crowning mechanism 19 includes an eccentric shaft 20, an eccentric ring 30, and a servo motor 50.

The eccentric shaft 20 is composed of three parts: a front part 20F, a central part 20C, and a rear part 20B, and rotates around a rotation axis Ar along the front-rear direction Y. The centers of the front portion 20F and the rear portion 20B coincide with the rotation axis Ar of the eccentric shaft 20, and the center of the center portion 20C is eccentric from the rotation axis Ar of the eccentric shaft 20 by a predetermined eccentric amount ΔE. The eccentric shaft 20 is inserted into the through hole 17. Specifically, the front portion 20F is inserted into a through hole 17F provided in the front support plate 11, and the rear portion 20B is inserted into a through hole 17B provided in the rear support plate 13. The eccentric shaft 20 is supported by the front support plate 11 and the rear support plate 13 via the eccentric ring 30. Specifically, the front portion 20F is supported by the front support plate 11 via the eccentric ring 30, and the rear portion 20B is supported by the rear support plate 13 via the eccentric ring 30. In a state where the eccentric shaft 20 is supported by the front and rear support plates 11 and 13, the central portion 20C is located below the pressure receiving surface 5P of the fixed table 5. In this embodiment, the pressure receiving surface 5P of the fixed table 5 is provided at the lower end of the fixed table 5.

The central portion 20C of the eccentric shaft 20 (hereinafter also referred to as the "eccentric shaft central portion 20C") is surrounded by a central ring 70 having a through hole in the center. A pair of bearing portions 42 arranged in the front-rear direction are fitted into the center ring 70, and the eccentric shaft center portion 20C is rotatably supported by the pair of bearing portions 42. When the eccentric shaft 20 rotates in the rotation direction R around the rotation axis Ar, the eccentric shaft center portion 20C, which is eccentric by a predetermined eccentric amount ΔE from the rotation axis Ar, moves in the vertical direction. As the center ring 70 moves in the vertical direction as the eccentric shaft central portion 20C moves, the center ring 70 moves the pressure receiving surface 5P of the fixed table 5 upwardly with respect to the front and rear support plates 11 and 13. to press. Thereby, the eccentric shaft 20 causes the fixed table 5 to curve upward in a convex manner.

The eccentric ring 30 is a cylindrical ring that is provided on the front and rear support plates 11 and 13, respectively, and adjusts the position of the eccentric shaft center portion 20C with respect to the pressure receiving surface 5P of the fixed table 5. In the present embodiment, the eccentric ring 30 is provided on the front and rear support plates 11 and 13, respectively, but the eccentric ring 30 is provided on at least one support plate 11 (or 13) of the front and rear support plates 11 and 13. It is sufficient if it is provided.

The eccentric ring 30 has an outer peripheral part 31 supported by through holes 17F and 17B provided in the front and rear support plates 11 and 13, and an inner peripheral part that supports the eccentric shaft 20 rotatably around the rotation axis Ar. 32. A bearing portion 40 that pivotally supports the eccentric shaft 20 is fitted into the inner peripheral portion 32 . The bearing portion 40 is, for example, a self-aligning roller bearing. A front portion 20F and a rear portion 20B of the eccentric shaft 20 are rotatably supported by a bearing portion 40. As shown in FIG. 5, in the eccentric ring 30, the center 32C of the inner peripheral part 32 is eccentric with respect to the center 31C of the outer peripheral part 31. In a state where the inner peripheral part 32 supports the eccentric shaft 20, the center 32C of the inner peripheral part 32 and the rotation axis Ar of the eccentric shaft 20 coincide. By rotating the eccentric ring 30 relative to the through hole 17, the position of the eccentric shaft 20 relative to the through hole 17 can be adjusted in the vertical direction, and the positional relationship between the eccentric shaft central portion 20C and the pressure receiving surface 5P can be adjusted. Can be adjusted up and down.

As shown in FIGS. 5 and 6, a notch 33 is formed in the outer peripheral portion 31 of the eccentric ring 30 along a plane parallel to the rotation axis Ar. The notch 33 extends from the front end 34 of the eccentric ring 30 to the rear end 35.

It is preferable that the notch portion 33 is formed at a portion opposite to a portion where the thickness of the outer peripheral portion 31 and the inner peripheral portion 32 of the eccentric ring 30 is the thinnest. The size of the notch portion 33 may be appropriately set depending on the clearance between the eccentric ring 30 and the through hole portion 17 that is required when the crowning mechanism 19 is inserted into the through hole portion 17. Specifically, when inserting the crowning mechanism 19 from the rear support plate 13 side, the eccentric ring 30 and the through holes 17F and 17B are connected to each other, which is necessary when the eccentric ring 30 passes through the through holes 17F and 17B. The clearance is set as appropriate.

In addition, in this embodiment, an example was shown in which the bearing part 40 was fitted into the inner peripheral part 32 of the eccentric ring 30, but the eccentric ring 30 may be integrated into the outer peripheral part 41 of the bearing part 40. . Specifically, the outer circumferential portion 41 of the bearing portion 40 may have the shape of the outer circumferential portion 31 of the eccentric ring 30. In this case, for example, when the bearing portion 40 is a self-aligning roller bearing, the shape of the bearing ring having the outer circumferential portion 41 is the shape of the outer circumferential portion 31 of the eccentric ring 30.

The servo motor 50 is fixed to the rear support plate 13 via a motor base 51. The rotation of the servo motor 50 is decelerated by the reducer 52 and transmitted to the eccentric shaft 20 via the connecting portion 53. The servo motor 50 rotates the eccentric shaft 20.

The configuration of the crowning mechanism 19 has been described above. The left and right crowning mechanisms 19L, 19R can be independently controlled. By independently controlling the left and right crowning mechanisms 19L and 19R, the curved state of the fixed table 5 can be adjusted. Adjustment of the curved state includes adjusting the position where the fixed table 5 is curved, such as the left side, the center, and the right side, the shape of the curve, the degree of the curve, and the like.

The control device 80 is, for example, a computer such as a numerical control device (NC (Numerical Control) device). A computer mainly includes a hardware processor such as a CPU (Central Processing Unit), memory, and various interfaces. Memory and various interfaces are connected to the hardware processor via a bus. A predetermined computer program is installed on the computer. The computer executes the functions provided by the control device 80 by the hardware processor executing the computer program.

The control device 80 controls the operation of the bending machine 1. Specifically, the control device 80 controls the left and right hydraulic cylinders 9L, 9R and the left and right crowning mechanisms 19L, 19R. The control device 80 can control the movement of the movable table 7 in the vertical direction Z and the curved state of the fixed table 5 by controlling the left and right hydraulic cylinders 9L and 9R and the left and right crowning mechanisms 19L and 19R.

The control device 80 includes workpiece information such as the thickness, bending length, and material of the workpiece, product information such as the bending angle and flange dimensions, mold information such as the types, dimensions, and angles of the lower mold 6 and upper mold 8; The bending state of the fixed table 5 is controlled based on processing information such as the positions of the lower die 6 and the upper die 8. Specifically, the control device 80 calculates the amount of deflection in the left-right direction X of the movable table 7 and the fixed table 5 during bending based on workpiece information, product information, mold information, processing information, and the like. The control device 80 causes the servo motors 50 of the crowning mechanisms 19L and 19R to rotate the eccentric shaft 20 so as to cancel the amount of deflection of the movable table 7 and the fixed table 5 and to maintain a constant distance between the upper mold 8 and the lower mold 6. to curve the fixed table 5. The rotation angle of the eccentric shaft 20 is calculated based on a predetermined eccentricity amount ΔE of the eccentric shaft central portion 20C.

In the bending machine 1 having such a configuration, a plate-shaped workpiece is positioned on the lower mold 6 mounted on the fixed table 5. The control device 80 lowers the movable table 7 toward the fixed table 5. As a result, the work is pressurized between the upper mold 8 and the lower mold 6, and the work is bent to a desired target bending angle by the cooperation of the upper mold 8 and the lower mold 6.

However, if the positional relationship between the eccentric shaft central portion 20C and the pressure receiving surface 5P of the fixed table 5 is not the ideal positional relationship, the vertical movement amount and speed of the eccentric shaft central portion 20C with respect to the pressure receiving surface 5P may not match the target values. First, the distance between the upper die 8 and the lower die 6 during bending may not be constant. In this case, by adjusting the position of the eccentric shaft 20 with respect to the through hole portion 17 using the eccentric ring 30, the positional relationship between the eccentric shaft central portion 20C and the pressure receiving surface 5P can be adjusted to an ideal positional relationship. . Thereby, the distance between the upper die 8 and the lower die 6 during bending can be kept constant.

FIG. 7 is an explanatory diagram schematically showing the action of the eccentric ring. Hereinafter, with reference to FIGS. 5 and 7, a mechanism in which the position of the eccentric shaft center portion 20C with respect to the pressure receiving surface 5P is adjusted by the eccentric ring 30 will be described.

As shown in FIG. 5, the position of the eccentric shaft 20 with respect to the through hole portion 17 changes as the eccentric ring 30 rotates. Specifically, by rotating the eccentric ring 30 in the rotation direction R around the rotation axis Ar, the position of the eccentric shaft 20 relative to the through hole portion 17 changes. For example, as shown in FIG. 5A, when the eccentric ring 30 is rotated around the rotation axis Ar, the center 32C of the inner peripheral part 32 is eccentric with respect to the center 31C of the outer peripheral part 31. As shown in FIG. 5(b), the inner peripheral portion 32 moves upward. Therefore, the position of the eccentric shaft 20 moves upward with respect to the through hole portion 17. Thereby, the position of the eccentric shaft 20 with respect to the through hole portion 17 can be adjusted upward. In this manner, by rotating the eccentric ring 30 around the rotation axis Ar, the position of the eccentric shaft 20 with respect to the through hole portion 17 can be adjusted, and in turn, the position of the eccentric shaft central portion 20C with respect to the pressure receiving surface 5P. can be adjusted.

Next, with reference to FIG. 7, the relationship between the movement range of the crowning output surface in the vertical direction Z and the movement amount 5M of the pressure receiving surface 5P will be described. Here, the crowning output surface corresponds to the upper surface of the center ring 70 that presses the pressure receiving surface 5P.

(a) to (c) shown in FIG. 7 show the movement range of the crowning output surface in the vertical direction Z when using a ring 38 in which the center 32C of the inner peripheral part 32 and the center 31C of the outer peripheral part 31 are not eccentric. It shows the relationship between the amount of movement 5M of the pressure receiving surface 5P and the amount of movement 5M of the pressure receiving surface 5P.

(d) to (f) shown in FIG. 7 show the relationship between the movement range of the crowning output surface in the vertical direction Z and the movement amount 5M of the pressure receiving surface 5P when the eccentric ring 30 is used.

First, with reference to (a) and (d), the relationship between the movement range of the crowning output surface in the vertical direction Z and the movement amount 5M of the pressure receiving surface 5P when the fixed table 5 is at the ideal position 5i will be described.

First, it is assumed that the pressure receiving surface 5P of the fixed table 5 is at the ideal position 5i. When the pressure receiving surface 5P of the fixed table 5 is at the ideal position 5i, the crowning output surface contacts the pressure receiving surface 5P of the fixed table 5 in a predetermined state (eg, no load).

When the eccentric shaft 20 is rotated by a predetermined rotation angle, the central portion 20C of the eccentric shaft moves upward, and the crowning output surface moves from the origin position 70L to the raised position 70H.

As the crowning output surface moves upward from the origin position 70L to the raised position 70H, the pressure receiving surface 5P of the fixed table 5 is pressed by the center ring 70 and rises from the position 5L to the position 5H. Therefore, when the pressure receiving surface 5P is at the ideal position 5i, the movement amount 5M of the pressure receiving surface 5P is from the position 5L at the ideal position 5i to the position 5H.

As shown in (d), when the eccentric ring 30 is used and the pressure receiving surface 5P of the fixed table 5 is at the ideal position 5i, the center 31C of the outer peripheral part 31 and the inner peripheral part 32 of the eccentric ring 30 are The center 32C is placed on one horizontal line in the left-right direction X. That is, the inner circumferential portion 32 is in a neutral position state in which it is not moving in either the up or down direction Z.

Next, referring to (b) and (e), the movement range of the crowning output surface in the vertical direction Z when the pressure receiving surface 5P of the fixed table 5 is at the position 5L shifted upward by ΔE1 from the ideal position 5i. The relationship with the amount of movement of the pressure receiving surface 5P will be explained.

As described above, the crowning output surface moves in the vertical direction Z in the range from the origin position 70L to the raised position 70H. However, the pressure receiving surface 5P of the fixed table 5 is at a position 5L shifted upward by ΔE1 from the ideal position 5i. Therefore, the pressure receiving surface 5P does not rise until the crowning output surface moves upward and presses the pressure receiving surface 5P at the position 5L. Therefore, when the position of the pressure receiving surface 5P deviates upward by ΔE1 from the ideal position 5i, a dead zone region ΔE1 occurs in which the pressure receiving surface 5P does not rise even though the crowning output surface is moving upward. As a result, the rotation angle of the eccentric shaft 20 and the amount of movement of the fixed table 5 in the vertical direction Z do not match, and the amount of upward movement of the fixed table 5 is insufficient with respect to the target amount of movement. Therefore, the amount of movement 5M of the pressure receiving surface 5P is short by ΔE1 compared to the case where the pressure receiving surface 5P is at the ideal position 5i. Furthermore, the rotation angle of the eccentric shaft 20 when the crowning output surface starts pressing the pressure receiving surface 5P is different from the initially assumed angle, so that the rotation speed of the eccentric shaft 20 may not reach the target rotation speed. .

Next, with reference to (c) and (f), the relationship between the movement range of the crowning output surface in the vertical direction Z and the amount of movement of the pressure receiving surface 5P when the position of the crowning output surface with respect to the pressure receiving surface 5P is adjusted will be explained. do.

In (c), by rotating the eccentric shaft 20, the origin position 70L of the crowning output surface is raised to the position 70P of the pressure receiving surface 5P, thereby eliminating the dead zone region ΔE1. However, the eccentric shaft 20 has already rotated by the dead zone area ΔE1. Therefore, even if the rotation angle of the eccentric shaft 20 is increased, it may not be possible to obtain the same amount of movement 5M as when the pressure receiving surface 5P is at the ideal position 5i, and the pressure receiving surface 5P may not be able to reach the target position 5H. It may not be possible to raise it.

In (f), the eccentric ring 30 is rotated around the rotation axis Ar, and the origin position 70L of the crowning output surface is moved upward by the dead zone area ΔE1. That is, the position of the eccentric shaft 20 with respect to the through hole portion 17 is moved upward by the dead zone area ΔE1, and the crowning output surface is adjusted to be at the origin position 70L. As a result, even if the pressure receiving surface 5P is at a position deviated from the ideal position 5i, the fixed table 5 can adjust the movement range of the crowning output surface in the vertical direction Z and the movement amount of the pressure receiving surface 5P to the ideal position 5i. You can do the same thing as in . Furthermore, since the rotation angle of the eccentric shaft 20 when the crowning output surface starts pressing the pressure receiving surface 5P can be set to the initially assumed angle, the rotation speed of the eccentric shaft 20 can be set to the target rotation speed. I can do it.

[Effect]
As explained above, according to this embodiment, the following effects can be obtained.

The bending machine 1 has a cylindrical eccentric provided on at least one of the front support plate 11 and the rear support plate 13 to adjust the position of the eccentric shaft central portion 20C with respect to the pressure receiving surface 5P of the fixed table 5. A ring 30 is provided. The eccentric ring 30 has an outer peripheral part 31 supported by a through hole 17F (or 17B) provided in at least one support plate 11 (or 13), and an inner part that supports the eccentric shaft 20 rotatably around the rotation axis Ar. A center 32C of the inner circumference 32 is eccentric with respect to a center 31C of the outer circumference 31.

The bending machine 1 can adjust the position of the eccentric shaft 20 with respect to the through hole 17 because the center 32C of the inner peripheral part 32 of the eccentric ring 30 is eccentric with respect to the center 31C of the outer peripheral part 31. . Therefore, by adjusting the position of the eccentric shaft 20 with respect to the through-hole portion 17, the bending machine 1 adjusts the movement amount and speed of the eccentric shaft central portion 20C relative to the pressure receiving surface 5P to the target value during bending. can do. Thereby, the bending machine 1 can set the interval between the punch and the die at the time of bending to a target interval, and can improve passing accuracy.

A bearing part 40 that pivotally supports the eccentric shaft 20 is fitted into the inner peripheral part 32 of the eccentric ring 30, and by rotating the eccentric ring 30 around the rotation axis Ar, the eccentric ring 30 is rotated about the rotation axis Ar. The position of the central portion 20C of the shaft 20 changes relatively. Thereby, the bending machine 1 can adjust the position of the center portion 20C of the eccentric shaft 20 with respect to the pressure receiving surface 5P of the fixed table 5.

The eccentric ring 30 may be integrated with the outer circumferential portion of the bearing portion 40. Thereby, the bending machine 1 can change the position of the eccentric shaft 20 relative to the through-hole portion 17 while reducing the number of parts constituting the bending machine 1. Thereby, the bending machine 1 can adjust the position of the center portion 20C of the eccentric shaft 20 with respect to the pressure receiving surface 5P of the fixed table 5.

A notch 33 is formed in the outer circumferential portion 31 of the eccentric ring 30 along a plane parallel to the rotation axis Ar, and the notch 33 extends from the front end 34 of the eccentric ring 30. It extends to the rear end 35. Thereby, the eccentric ring 30 can provide a clearance between the eccentric ring 30 and the through holes 17L, 17R when inserting the left and right crowning mechanisms 19L, 19R into the left and right through holes 17L, 17R, and the crowning mechanism 19L, 19 can be easily inserted into the through holes 17L, 17R.

It is preferable that the notch portion 33 is formed at a portion opposite to a portion where the thickness of the outer peripheral portion 31 and the inner peripheral portion 32 of the eccentric ring 30 is the thinnest. The portion opposite to the portion where the outer circumferential portion 31 and the inner circumferential portion 32 are the thinnest is the portion where the outer circumferential portion 31 and the inner circumferential portion 32 are the thickest. Therefore, by forming the cutout part 33 in the part where the thickness of the outer peripheral part 31 and the inner peripheral part 32 is the thickest, the eccentric ring can be used when inserting the crowning mechanisms 19L and 19R into the left and right through holes 17L and 17R. The clearance between 30 and the through holes 17L and 17R can be made larger.

As described above, embodiments of the present invention have been described, but the statements and drawings that form part of this disclosure should not be understood as limiting the present invention. Various alternative embodiments, implementations, and operational techniques will be apparent to those skilled in the art from this disclosure.

1 Bending machine 5 Fixed table 5P Pressure receiving surface 7 Movable table 11 Front support plate 13 Rear support plate 17L, 17R Through hole portion 17F Through hole provided in support plate 11 17B Through hole provided in support plate 13 20 Eccentric shaft 20F Front part 20C Central part 20B Rear part 30 Eccentric ring 31 Outer part 31C Center of outer part 31 32 Inner part 32C Center of inner part 32 33 Notch part 34 Front end 35 Rear end 40 Bearing part Ar Rotating shaft ΔE Predetermined eccentricity

Claims (5)

A bending machine including a movable table that moves in the vertical direction and a fixed table that is disposed at a position opposite to the movable table in the vertical direction,
a front support plate and a rear support plate arranged on both sides of the fixed table in the front-rear direction;
A predetermined eccentricity from the rotation axis when inserted into the through holes penetrating in the front-rear direction provided in the front support plate and the rear support plate respectively, and rotated around the rotation axis along the front-rear direction. an eccentric shaft that bends the fixed table by moving up and down a central portion eccentric by an amount and pressing a pressure-receiving surface of the fixed table;
a cylindrical eccentric ring provided on at least one of the front support plate and the rear support plate to adjust the position of the central portion of the eccentric shaft with respect to the pressure receiving surface of the fixed table; ,
The eccentric ring is
an outer peripheral portion supported by the through hole provided in the at least one support plate;
an inner peripheral portion that rotatably supports the eccentric shaft around the rotating shaft;
A bending machine in which the center of the inner circumference is eccentric with respect to the center of the outer circumference. A bearing portion that pivotally supports the eccentric shaft is fitted into the inner peripheral portion of the eccentric ring,
The bending machine according to claim 1, wherein the position of the central portion of the eccentric shaft changes relative to the pressure receiving surface of the fixed table by rotating the eccentric ring around the rotating shaft. The bending machine according to claim 2, wherein the eccentric ring is integrated with an outer peripheral portion of the bearing portion. A cutout portion cut out along a plane parallel to the rotation axis is formed in the outer peripheral portion of the eccentric ring,
The bending machine according to any one of claims 1 to 3, wherein the notch extends from a front end to a rear end of the eccentric ring. The bending machine according to claim 4, wherein the cutout portion is formed at a portion opposite to a portion where the thickness of the outer circumferential portion and the inner circumferential portion of the eccentric ring is the thinnest.

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