KR100221345B1 - Bending machine - Google Patents

Abstract

[purpose]

An electric motor is used as the driving source, and the bending device moving the bending through the link is used to accurately bend the workpiece at a predetermined bending angle.

[Configuration]

The bending arm is pivotally attached to the base. The bending arm is provided with a bending type and a tightening type. The bending arm is connected by a link with a drive arm rotating by the output side of the electric motor. The bending arm rotates through the drive arm and the link by the rotation of the output shaft of the electric motor. As a result, the workpiece clamped by the tightening die is bent along the bending die. In this case, the rotation speed of the output shaft of the electric motor is controlled by the control means so that the bending arm rotates at a constant speed.

Description

Bending device

1 is a partially broken perspective view of a bending device.

2 is a side view of the bending device.

3 is a plan view of the drive mechanism of the bending arm.

4 is a block diagram of a control means.

5 is a graph showing the relationship between the rotation angle of the bending arm and the operating angle of the output shaft of the electric motor with respect to the operating angle of the bending arm at 1 ° at the rotation angle.

* Explanation of symbols for main parts of the drawings

10: base 15: bending arm

16: bending type 18: tightening type

23: electric motor 25: output shaft

26: driving arm 28: link

50: control means

The present invention relates to a bending device for bending a workpiece by inserting a long workpiece such as a pipe or a rod into a bending type and a tightening type, and moving the tightening type to an arc around the bending type.

As a bending apparatus, the thing of the following structures is known conventionally. That is, the vertical shaft is freely rotatable. The base of the bending arm is also fixed to the middle of the shaft. The base of the bending arm is fixed to the upper end of the shaft. A bending type is provided at the upper end of the shaft, and a tightening type for clamping the workpiece into the bending type is provided on the bending arm. The chain sprocket mounted on the lower part of the shaft is connected to the chain sprocket mounted on the output shaft of the electric motor through the chain. As the shaft of the bending arm is rotated through the chain by the electric motor, the workpiece sandwiched between the bending type and the tightening type is bent in accordance with the bending type. As a bending device of this kind, there is shown, for example, in US Patent Nos. 4, 236, 398.

This kind of bending device is convenient because it can be operated by using the power supply equipment which is being used universally. However, with this device, the sprocket at the lower side of the bending type can interfere with the bending of the workpiece. For example, when the workpiece is bent three-dimensionally, that is, when bending in different directions is sequentially performed at a plurality of locations, the tip of the workpiece may come into contact with the sprocket.

Bending device that is easy to bend the workpiece in three dimensions is a bending device of the following structure. That is, a bending arm is pivotally attached to the front end of the base. The bending arm is provided with a bending type and a tightening type. The driving arm is pivotally attached to a position later than the pivoting position of the bending arm on the base. The bending arm and the driving arm are connected by a link. A hydraulic cylinder is connected to the drive arm. As the hydraulic cylinder extends, the drive arm rotates and the bending arm rotates through the link. As a result, the workpiece sandwiched between the bending die and the tightening die is bent in accordance with the bending die. As a bending device of this kind, there is shown, for example, in US Patent Nos. 4, 938, 047. Such a bending device easily performs the three-dimensional bending processing of the work because the space below the bending type is open.

However, this kind of device requires large auxiliary equipment such as a hydraulic pump or a hydraulic tank to operate the hydraulic cylinder.

The inventor attempted to rotate the drive arm by an electric motor instead of the hydraulic cylinder. The reason is that the electric motor can use a power supply facility that is used as a general driving source. That is, it is because it is simple compared with the said auxiliary equipment of a hydraulic cylinder.

However, the rotation of the drive arm by an electric motor has the following properties. That is, the angle between the drive arm and the link or the angle between the link and the bending arm changes depending on the magnitude of the rotation angle from the start position of the bending arm. Therefore, even if the drive arm rotates at a constant speed because the output shaft of the electric motor rotates at a constant speed, the rotation speed of the bending arm changes in accordance with the change of the rotation angle of the bending arm.

The above properties cause the problems described below when the workpiece is bent. When a bending device is operated to bend a workpiece, the electric motor, drive arm, link, and bending arm all generate inertia. Therefore, when the workpiece is bent at a predetermined bending angle, the bending arm is stopped with respect to the predetermined angle in order to stop the bending arm accurately and without impact when the rotation angle of the bending arm reaches a predetermined angle corresponding to the bending angle. It is necessary to start the deceleration of the electric motor where it has rotated to a point of an angle as small as a certain angle. However, if there is such a property, that is, the property that the rotational speed of the bending arm changes with the change of the rotation angle of the bending arm, the following problems arise. That is, even if the deceleration speed of the bending arm is determined so that the bending arm stops exactly at the predetermined angle when the predetermined angle is at a certain angle, when the predetermined angle is at another angle different from the specific angle, the bending arm Because of the different rotation speeds, the problem is that the bending arm does not stop exactly at its intended angle. For example, when the bending speed of the bending arm is large, the bending arm rolls over a predetermined angle. On the contrary, when the bending speed of the bending arm is small, the bending arm stops before reaching the predetermined angle. These both degrade the accuracy of the bending angle of the workpiece.

The present invention has been made to solve the problems (technical problems) of the prior art.

It is an object of the present invention to provide a bending device which is easy to bend a workpiece in three dimensions.

In the present invention, the bending arm is a structure that is rotated through the link by the driving arm of the rear portion thereof. Therefore, there is only a bending arm under the bending die, and the lower side thereof is open. In that open space the already bent tip of the workpiece can be freely positioned. As a result, it is easy to bend the workpiece in three dimensions.

Another object of the present invention is to provide a bending device using an electric motor as a drive source of the drive arm. Electric motors have the convenience of being easily operated using a universal power supply.

Another object of the present invention is to provide a bending device capable of precisely bending a workpiece at a predetermined bending angle, even if the electric motor is used as a driving source and the structure of moving the bending arm through a link.

In the present invention, even if a link is interposed between the output shaft of the electric motor and the bending arm, the rotational speed of the output shaft is controlled so that the bending arm rotates at a constant speed despite the change in the rotation angle. As described above, when the workpiece is bent by rotating the bending arm by the rotation of the electric motor and decelerating the bending arm by the deceleration of the electric motor, the bending arm of the bending arm may be of any size. The rotational speed of the bending arm at the point of starting deceleration is the same. Accordingly, the bending arm can be accurately stopped at the predetermined angle by decelerating the electric motor so that the bending arm decelerates at a predetermined speed, regardless of the predetermined bending angle of the workpiece. In other words, the workpiece can be bent accurately at a predetermined bending angle.

In order to achieve the above object, the bending device according to the present invention includes a base, a bending arm pivotally attached to the front end of the base, a bending type arranged in a state in which the pivot center and the center of the bending arm are aligned; A fastening type provided on the bending arm for clamping the workpiece, a drive arm pivoted at a position later than a pivoting position of the bending arm on the base, and a link connecting the bending arm and the drive arm. A bending device comprising: an output shaft of an electric motor for rotating it to the drive arm, and the motor is provided with control means for controlling the rotation speed of the output shaft so that the rotation speed of the bending arm is constant.

The drive arm rotates by rotating the output shaft of the electric motor. This rotation is transmitted to the bending arm through the link to rotate the bending arm. As a result, the clamped workpiece is bent in accordance with the bending die. In this case, the rotational speed of the output shaft of the electric motor is controlled so that the bending arm rotates at a constant speed.

EXAMPLE

In FIG. 1, 2, 3, the base 10 consists of the main body 11 and the support part 12 provided in the front end. The workpiece | work W is supplied in the supply direction shown by the arrow 21 to FIG. 1, 2 by the well-known carriage (not shown) provided on the main body 11. As shown in FIG. The work W includes a pipe and a rod, and the cross section has a ring and an angle. In addition, in this specification, the front side (postal in FIG. 2) to which the said workpiece | work W is supplied is called the front, and the reverse side is called the back. In the support part 12, the vertical shaft 13 is freely rotated by the tapered roller bearing 14. The upper and lower ends of the shaft 13 protrude upward and downward from the support part 12. The bending arm 15 has its base in two parts, and its two parts 15a, 15a are provided in the projection of the shaft 13. The bending arm 15 is provided with a shaft 15b for a bending device in a state in which the shaft 13 and the center are aligned. The bending die 16 is attached to this shaft 15b so that attachment and detachment are possible. The bending die 16 has a groove 17 into which the work W is fitted. A clamping die 18 for clamping the workpiece W to the bending die 16 is freely provided on the bending arm 15 in the longitudinal direction of the bending arm 15. The tightening die 18 is moved to the bending die 16 in a perspective manner as is known by the moving mechanism provided in the bending arm 15. The clamping die 18 has a groove 19 into which the work W is fitted on the side opposite to the bending die 16. The support portion 12 is provided with a support type (called a pressure type) 20. The support 20 receives the reaction force of the work W when bending the work W. FIG. The supporting die 20 can be changed in position as indicated by an arrow in a horizontal direction perpendicular to the supply direction of the workpiece W, depending on the radius of the bending die 16 and the thickness of the workpiece W. FIG.

Next, the driving mechanism 22 for rotating the bending arm 15 together with the shaft 13 will be described. The electric motor 23 for a drive is attached to the bracket 24 attached to the main body 11. As shown in FIG. As this motor 23, for example, a servomotor with a reduction gear is used. The output shaft 25 of the motor 23 is in a vertical state at a position behind the shaft 13. The drive arm 26 is fixed to the output shaft 25 by the key 25a at one end thereof. The other end of the drive arm 26 has two parts, up and down. The link 28 connects the drive arm 26 and the bending arm 15. One end of the link 28 is located between the two parts 27, 27 of the drive arm 26, and the rotation is freely connected by the bearing 30 to the pin 29 fixed to the two parts 27, 27. It is. The other end of the link 28 is rotatably connected by the bearing 32 to the connecting shaft piece 31 protruding from the lower surface of the bending arm 15. The end cap 33 mounted to the shaft piece 31 prevents the link 28 from being separated from the shaft piece 31.

As shown in FIG. 2, the detector tool 35 for detecting the rotation angle of a bending arm is provided under the support part 12. As shown in FIG. An encoder 36 used as an angle detector is attached to the support 12 by a stay 37. The timing pulley 39 is attached to the rotation shaft (input shaft) 38 of the encoder 36. Under the two portions 15a of the bending arm 15, the timing pulley 40 is installed with the shaft 13 and the center visible. The timing belt 41 is provided in both timing pulleys 39 and 40.

Next, the relationship between the bending arm 15, the drive arm 26, the link 28 and the like will be described with reference to FIG. These constitute 4 linkage mechanisms together with the base 10 and the bracket 24 which function as fixed links. In this example, the length L1 to L4 of each link, that is, the distance L1 between the center 01 of the shaft 13 and the center 02 of the output shaft 25, the center 01 of the shaft 13 and the shaft piece Distance L2 between center A of center 31, distance L3 between center 02 of output shaft 25 and center B of pin 29, center A of shaft piece 31. The relationship between the distance L4 between the center and the center B of the pin 29 is as follows.

[Equation 1]

L3〉 L4〉 L2〉 L1

More specifically, L1 is 62.6 mm, L2 is 70 mm, L3 is 122 mm, and L4 is 98.7 mm. As a result, when the rotation angle θ of the driving arm 26 is about 100 °, the rotation angle α of the bending arm 15 is about 180 °. That is, the angle of rotation of the driving arm 26 is enlarged and the bending arm 15 rotates. In addition, the magnitude relationship of the length of each link is not limited to the relationship of said formula (1), What is necessary is just to determine so that the rotation angle (alpha) of the bending arm 15 desired may be obtained with respect to the rotation angle (theta) of the drive arm 26.

Next, the control means 50 of the electric motor 23 is demonstrated based on FIG. The control means 50 comprises a bending angle setting means 51, a comparison means 52, a servo amplification means 53, a correction means 54, a driving amplification means 55, and the angle detector 36. It is. The bending angle setting means 51, the comparison means 52, the servo amplification means 53 and the drive amplifying means 55 are the same as those known in the known servo control mechanism. The correction means 54 is for applying correction as described later to the output of the servo amplification means 53. Each means represented by said code | symbol 51-55 is comprised by the hardware of a computer, and the software for moving it, for example. However, it may be constituted by a separate electric circuit. In that case, each means is called a bending angle setter 51, a comparator 52, a servo amplifier 53, a correction circuit 54, a drive amplifier 55, and the like. There is no difference in functionality. The drive arm 26, link 28 and bending arm 15 are shown as driven system 56.

Next, the bending process of the workpiece | work W by the said bending apparatus is demonstrated. In the state where the bending arm 15 is in the start position shown in the solid line in FIG. 1 and FIG. 3, respectively, the position which becomes a state orthogonal to the supply direction 21 of the workpiece | work W in this example, the workpiece | work W ) Is supplied in the direction of the arrow 21, and a portion to be bent is located between the bending die 16 and the tightening die 18. The location is clamped to the bending die 16 by the clamping die 18. In addition, the support die 20 is appropriately moved in the direction of the arrow to reach the work W. Next, the electric motor 23 is driven by the control by the control means 50. The drive arm 26 rotates clockwise in FIG. 3 by the rotation of the output shaft 25 of the electric motor 23. The rotational force is transmitted to the bending arm 15 via the link 28 so that the bending arm 15 rotates clockwise. The bending die 16 and the clamping die 18 on the bending arm 15 rotate around the center of the bending die 16 with the workpiece W sandwiched therein, and the workpiece W bends along the bending die 16. do. The bending of the bending arm 15 is performed up to a predetermined bending angle corresponding to the predetermined bending angle of the work W (the angle at which the spring back of the work W is added to the predetermined bending angle of the work W). When the rotation of the bending arm 15 to the predetermined angle is completed, the clamp of the workpiece W is released by the tightening die 18, and the bending arm (reversal) of the output shaft 25 of the electric motor 23 is performed. 15) Go back to the original starting position. Thereby, the bending process of the workpiece | work W in the said location is completed.

The bending of the work W by the above-described operation is repeated in sequence with respect to the points to be bent in the work W, respectively, to process the work W into a predetermined three-dimensional shape.

Next, the control of the electric motor 23 by the control means 50 in the case of the bending process of the said workpiece | work W is demonstrated. In the bending angle setting means 51, a predetermined angle for rotating the bending arm 15 is set. On the other hand, the rotation angle at the start position of the bending arm 15 is detected by the angle detector 36. The comparison means 52 compares the signal of the predetermined angle given from the angle setting means 51 with the signal of the rotation angle given from the angle detector 36, and outputs a signal corresponding to the angle difference between them. The servo amplifier 53 receives the signal and outputs a signal (for example, a voltage signal) corresponding to the speed at which the output shaft 25 of the electric motor 23 is to be rotated. In this case, the correction means 54 receives the angle signal from the angle detector 36, and gives the servo amplification means 53 a correction value (correction value of the rotational speed of the output side 25) corresponding to the angle. Therefore, the output signal from the servo amplification means 53 is a signal to which correction by the correction value was applied. The drive amplifying means 55 receives a signal from the servo amplifying means 53 and supplies electric power corresponding thereto to the electric motor 23. The output shaft 25 of the electric motor 23 rotates by the electric power, and the driven system 56 is driven.

Here, the correction by the correction means 54 will be described. In the driven system 56, the rotation of the drive arm 26 by the electric motor 23 is transmitted to the bending arm 15 via the link 28, so that the bending arm 15 rotates. In this case, the angle between the drive arm 26 and the link 28 or the angle between the link 28 and the bending arm 15 changes depending on the size of the rotation angle from the start position of the bending arm 15. do. For this reason, the angle of rotation of the bending arm 15 and the angle of operation of the output shaft 25 of the electric motor 23 with respect to the constant angle of operation of the bending arm 15 (for example, 1 °) at the angle of rotation The relationship of is as shown in the column (a) and (b) of Table 1 shown later, for example. That is, it becomes a relationship which draws the curve as shown in FIG. Thus, in the correction means 54, the rotational speed of the output shaft 25 of the electric motor 23 is changed while drawing a curve such as the curve of FIG. 5 with the change of the rotational angle of the bending arm 15. The correction values as shown in column (c) of Table 1 are stored in advance. The correction value of this column (c) is, for example, the column (b) in various angles based on the numerical value of the column (b) in the case where the rotation angle of the bending arm 15 is 51 ° to 60 °. It is the numerical value obtained by dividing each numerical value of by its reference value.

The above correction values are given from the correction means 54 to the servo amplification means 53, so that the servo amplification means 53 uses the output shaft 25 of the electric motor 23 by the signal from the comparing means 52. A signal for rotating at a speed obtained by multiplying the determined rotation speed by a magnification of the correction value is output.

As a result of the correction described above, the rotation of the electric motor 23 is controlled, and as a result, the rotational speed of the output shaft 25 of the electric motor 23 is changed according to the change of the rotation angle of the bending arm 15. It changes while drawing a curve like a curve. As a result, the bending arm 15 rotates at a constant rotational speed despite the change in the rotational angle.

As described above, the bending arm 15 rotates at a constant speed, and reaches a point at a predetermined angle, for example, as small as 10 ° (hereinafter referred to as a deceleration start angle), which is predetermined with respect to the predetermined angle, as follows. The deceleration of the electric motor 23 is performed. That is, when the signal from the comparator 52 becomes the signal of the constant angle, the servo amplifying means 53 reduces its output. Thereby, the output of the drive amplifying means 55 is also reduced, and the rotation speed of the output shaft 25 of the electric motor 23 is reduced. In this case, the rotational angle of the bending arm 15 is a predetermined value, for example, every time 1 ° advances, the rotation speed of the bending arm 15 is predetermined, for example, the rotational speed of the bending arm 15. The servo amplifying means 53 reduces its output based on the signal from the comparing means 52 so as to decelerate by (constant speed) divided by the constant angle. As a result, the bending arm 15 smoothly decreases and stops accurately at the predetermined angle.

Next, various embodiments will be described. When the positional relationship between the distal end of the support part 12 and the base of the bending arm 15 is composed of the relationship in which the electrons are located upward, the bending type 16 has the center of rotation and the center of the bending arm 15 aligned. The support 12 may be freely rotated in a state. In this case, the workpiece W is bent in the same manner as in the above case by the rotation of the bending arm 15. In the above case, the bending die 16 may be fixed to the support 12. In this case, the clamping die 18 revolves around the bending die 16 by the rotation of the bending arm 15. As a result, the workpiece W is pressed against the bending die 16 by the tightening die 18 gradually toward the front portion, and is bent along the bending die 16. As another example, as the bending type, two grooves which are mutually bent and provided with different radii may be used up and down, and as the tightening type, those grooves corresponding to each may be used up and down. Further, by appropriately selecting the lengths L1 to L4 of the four links, the rotation angle θ of the drive arm 26 may be reduced to allow the bending arm 15 to rotate. That is, as compared with the rotational torque of the output shaft 25 of the electric motor 23, the bending arm 15 may produce big bending torque.

As described above, in the present invention, the above object can be achieved, and the workpiece can be bent easily three-dimensionally, and furthermore, it can be operated using a general-purpose power supply facility, and the bending angle at which the workpiece is intended It can be bent accurately with the effect.

Claims (3)

A base 10, a bending arm 15 pivotally attached to the front end of the base, a bending type 16 arranged with the rotation center and the center of the bending arm aligned, installed on the bending arm and clamping the workpiece A fastening type 18 for driving, a drive arm 26 pivoted at a position rearward of the pivoting position of the bending arm on the base, and a link 28 connecting the bending arm and the drive arm. In the bending device, an output shaft 25 of an electric motor 23 for rotating it to the drive arm 26 is connected, and the rotating speed of the output shaft 25 is connected to the electric motor 23. Bending device, characterized in that the control means 50 for controlling the rotational speed of the control unit to be constant. 2. The distance from the center of rotation of the drive arm 26 to the connection position of the link 28 to the drive arm is defined by the link 28 of the link 28 to the bending arm. Bending device, characterized in that greater than the distance to the connection position. 2. An angle detector (36) for controlling the rotation angle of the bending arm, a bending angle setting means (51) for setting a predetermined angle for rotating the bending arm, and the bending angle A comparison means 52 which receives a signal of a predetermined angle from the setting means and a signal of the rotation angle from the angle detector and outputs a signal corresponding to the difference between the two angles, and receives a signal of the rotation angle from the angle detector Correction means (54) for outputting a correction value corresponding to the correction means, and a correction value by the correction value is added to the rotational speed of the electric motor determined by the signal from the comparison means and the correction value from the correction means. Servo amplifying means 53 for outputting a signal for rotating the electric motor at a speed, and a sphere for driving the electric motor by receiving the output of the servo amplifying means. The bending machine comprising the amplifying means (55).