JPS63174724A - Bending machine - Google Patents

Abstract

PURPOSE:To promoto the plastic deformation of a work piece and to perform the bending with high accuracy by guiding the work piece with the specified pressure by a moving die while under the bending by three points and giving an ultrasonic vibration to the punch tip part. CONSTITUTION:A pressure detector 17 detects the pressurizing force on to a vibration die 9d and based on the action of a control device the servovalve of a hydraulic cylinder 21 is controlled so that the pressurizing force becomes the specified one. The agitator main body 19a starts the vibration with the working start, concentrating the vibration energy to the tip vicinity of a punch 11, promoting the plastic deformation of the punch tip part of a work piece W by limiting the flow of the metal by plastic work to the tip vicinity of the punch and performing the bending of high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) The present invention relates to a bending machine capable of performing highly accurate bending.

(Prior Art) The conventional three-point bending process called air bending involves performing a well-known three-point bending process between a punch and a U-shaped die shoulder.

(Problems to be Solved by the Invention) However, in these conventional three-point bending processes using air bending, there are three points between the die shoulder and the punch tip.
Since the structure was designed to perform point bending, bending was performed only by moment, so the plastic deformation of the sheet metal at the punch tip did not occur smoothly as the punch moved relative to the die, and the bending shape at the punch tip of the workpiece There was a problem in that it appeared to be slightly bulging outward, making it difficult to perform high-precision bending.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned problems and provide a bending machine that can perform three-point bending with high accuracy.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention includes a bending machine including a punch, and a bending machine that cooperates with the punch with the tip position of the punch as an intermediate point. With a workpiece sandwiched between a fixed die that performs point bending and the tip of a punch disposed at an intermediate position between the fixed die, the punch moves as the punch moves relative to the fixed die. The present invention includes a movable die that moves along the fixed die while applying a predetermined pressing force between the two, and a vibrating means that applies ultrasonic vibration to the movable die and/or the punch.

(Function) In this invention, during three-point bending, as the punch tip moves relative to the die, the workpiece is guided by the moving die with a predetermined pressing force, and ultrasonic vibrations are applied to the punch tip. This promotes plastic deformation at the punch tip of the workpiece, resulting in high-precision bending with a small moment.

(Example) Referring to FIG. 1, a hydraulic bending machine is illustrated as an example of a bending machine embodying the present invention. FIG. 2 is an enlarged explanatory view of the main parts along the I[-11 arrow line in FIG. 1.

The bending machine 1 has left and right side frames 3R, 3.
L is provided vertically, and this side frame 3R, 3L
Both sides of a lower frame 5 extending in the left-right direction are appropriately supported at the lower part of the frame.

A ram 7 facing the lower frame 5 is provided above the lower frame 5 and is movable up and down.
A die 9 provided on the lower frame 5 is located at the bottom of the frame 5.
A punch 11 is attached to work in cooperation with the punch 11 to process the workpiece W.

In order to move the ram 7 up and down, each side frame 3R
, 3L are equipped with hydraulic cylinders 13R and 13L, respectively.
is installed, and each piston rond in each hydraulic cylinder 13R, 13L is connected to the ram 7 as appropriate. Valve blocks 15R, 15L equipped with various valves for controlling the operation of each hydraulic cylinder 13R113 are attached to the upper part of each of the hydraulic cylinders 13R, 13L.

As shown in FIG. 2, the die 9 includes fixed dies 9a and 9b fixed to the front and rear of the frame 5 with respect to the punch 11.
and a movable die 9C which is vertically movably provided at an intermediate position between the fixed dies 9a and 9b. The movable die 9C has a vibrating die 9d in the center, and a pressure detector 17 is built in the lower surface of the vibrating die 9d. The pressure detector 17 is composed of a piezoelectric element and outputs a predetermined voltage according to the applied force.

The movable die 9C is connected via a vibrator 19 to a hydraulic cylinder 21 for driving the die. The vibrator 19 has a vibrator main body 19a that is indirectly connected to the imaging die 9d via the pressure detector 17.

The vibrator body 19a is an ultrasonic oscillator composed of a piezoelectric element or a magnetostrictive element, and vibrates at a frequency of several tens of hertz in response to a predetermined voltage input, and imparts the vibration to the vibrating die 9d. be.

In the bending machine having the above configuration, the movable die 9C has its top surface aligned with the top surface of the fixed dies 9a and 9b before the bending process starts, and when the workpiece W starts bending, It descends while supporting the intermediate bending point on the upper surface of the vibrating die 9d.

At this time, the pressure detector 17 detects the pressure applied to the vibrating die 9d, and the servo pulp of the hydraulic cylinder 21 is controlled based on the action of a control device, which will be described later, so that the pressure becomes a predetermined value.

Moreover, the vibrator main body 19a starts vibrating at the same time as processing starts,
By concentrating vibration energy near the tip of the punch 11 and limiting the flow of metal due to plastic working to the vicinity of the punch tip, plastic deformation of the punch tip of the workpiece W is promoted, making it possible to perform high-precision bending. do.

FIG. 3 is a block diagram showing a control device of the bending machine 1. As shown in FIG.

The control device has a main control device 23 consisting of a CPU, a storage device 25 such as ROM and RAM, and an input/output device 27.
, A/D converter 17a, and voltage controller 29.3
1.33 is connected. The servo valves 15a arranged in the valve blocks 15R and 15L are connected to a voltage controller 29. The pressure detector 17 is connected to the main controller 2 via an A/D converter 17a.
Connected to 3. The vibrator 19 is connected to a voltage controller 31 . A servo valve 21a that controls the hydraulic cylinder 21 is connected to the voltage controller 33.

In the control device configured as described above, the voltage controller 29 outputs a control signal to the servo valve 15a to process the ram 7 at a predetermined speed to a predetermined position.

The pressure detector 17 detects the force F applied to the die 9 from the bunch 11, and outputs this to the main controller 23 via the A/D converter 17a. The main controller 23 controls the servo valve 21a via the voltage controller 33 so that the pressurizing force F becomes a predetermined value based on the detected pressure.

The vibrator 19 vibrates at a predetermined vibration cycle during the bending process,
The vibration is transmitted to the vibrating die 9d.

Due to the above action, the workpiece W shown in FIG.
Vibration is applied to the tip of the bunch 11 while receiving a predetermined pressing force, and three-point bending is performed.

During this time, the pressing force F is maintained at a predetermined value under the control of the main controller 23, so that no unreasonable bending force is applied. In addition, a predetermined ultrasonic vibration is applied to the tip of the bunch 11, and plastic deformation is easily performed, resulting in good processing accuracy. Note that since the vibration is ultrasonic, it will not make the working environment worse.

The frequency may be changed depending on processing conditions such as the material of the workpiece W, plate thickness, bending angle, etc. in order to perform bending with higher precision, or may be changed depending on the degree of progress of bending.

In the above example, the vibrator 19 is provided on the die 9 side, but the vibrator 19 can also be provided on the bunch 11 side.

Further, in the above example, the vibrator 19 is vibrated at the start of the machining process, but the vibrator 19 may be vibrated after the bending process has progressed to a certain extent.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented in other embodiments by making appropriate design changes.

[Effect of the invention 1 As described above, according to the present invention, since ultrasonic imaging is applied to the tip of the punch during bending, plastic deformation of the sheet metal is promoted at the tip of the punch, resulting in highly accurate bending. becomes possible.

[Brief explanation of the drawing]

Figure 1: Front view of the bending machine embodying this invention; Figure 2:
The figure is an enlarged explanatory view of the main part shown along the II-IF arrow line in FIG. 1, and FIG. 3 is a block diagram of the control device. 7...Bunch 9...Die 9a, 9b...Fixed die 9C...Moving die 17...1 pressure detector...Exciter Patent attorney Yasuo Miyoshi Figure 2 Figure 3

Claims (2)

[Claims] (1) A punch, a fixed die that performs 3-point bending in cooperation with the punch, with the punch tip position as an intermediate point, and a workpiece that is disposed at an intermediate position between the fixed die and the punch tip. a movable die that moves along the fixed die while maintaining a predetermined pressing force between the punch and the punch as the punch moves relative to the fixed die; and a vibration excitation unit that applies ultrasonic vibration to the punch. (2) The bending machine according to claim 1, wherein the pressing force is detected by a piezoelectric element and feedback-controlled.