JPH0417736B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention particularly relates to a deep drawing method and apparatus for performing deep drawing on difficult-to-process materials while applying ultrasonic vibrations. [Prior Art] Conventional deep drawing equipment processes difficult-to-process materials such as metal plates and plastic plates used to form safety valves for high-pressure gas cylinders while applying ultrasonic vibrations.
For example, there is something like the one shown in Figure 5 (``Plasticity and Processing'' Vol. 23, No. 256 (1982-5)). To explain the main parts of the processing apparatus shown in FIG. 5, a workpiece is placed between a wrinkle presser 1 having a vibrator 3 attached to its outer periphery and a die 2 having another vibrator 3 attached to its outer periphery. After inserting the blank plate 5, ultrasonic vibrations are mechanically generated by a plurality of radially arranged transducers 3 to press the wrinkle presser 1.
When the vibration is applied to the die 2, the wrinkle presser 1 and the die 2 concentrically expand and contract vibrations, so the wrinkle presser 1 is then pressurized with a hydraulic press, etc., and the punch 4 is raised while pressing the blank 5. When this is done, the blank is subjected to deep drawing. [Problems to be Solved by the Invention] However, in such a conventional ultrasonic processing method, a plurality of vibrators 3 are required in order to apply approximately axially symmetrical vibrations to the wrinkle presser 1 and the die 2. The problem was that the resonant frequencies of each vibrator had to be matched, making the design of the vibration system complicated. Further, since the vibrator is directly attached to the wrinkle presser and the die, the processing device can only be used for deep drawing processing, resulting in a loss of versatility. The present invention has been made in order to solve the above problems, and makes it unnecessary to match each resonant frequency as in the past, but makes it possible to vibrate the entire vibration system with one vibrator. Another object of the present invention is to provide a deep drawing method and apparatus that have versatility so that the processing device can be used for purposes other than deep drawing. [Means for Solving the Problems] In order to achieve the above-mentioned object, the deep drawing method according to the present invention involves sandwiching a blank between a vibrating die and a wrinkle holder, and drawing a blank sheet perpendicular to the machined surface of the vibrating die. A punch that passes through the center of the wrinkle presser while applying ultrasonic vibration that makes a one-dimensional axial reciprocating motion in the direction and converting this vibration into a radial vibration that expands and contracts concentrically on the processing surface and vibrates. The method is characterized in that the blank plate is subjected to drawing processing. Further, the processing device used to carry out the deep drawing method of the present invention includes a vibrating die having an annular hollow disk portion having a die processing surface and a coaxial shaft portion perpendicular to the hollow disk portion; It is characterized by comprising a vibration transmitting cone that is removably connected to the shaft via a connecting bolt and equipped with a vibrator that provides ultrasonic vibration in the axial direction. [Function] Since the vibrating die of the present invention has a structure having an annular hollow disk portion having a die processing surface and a coaxial shaft portion perpendicular to this, the resonance frequency of the shaft portion and the hollow disk It is possible to make the vibrating die resonate by finding the resonant frequency of the entire vibrating die where both parts resonate at the same time from the resonant frequency of the vibrating die. When sonic vibration is applied, the axial ultrasonic vibration generated in the shaft portion is converted into radial vibration that concentrically expands and contracts in the hollow disc portion. Therefore, since axial ultrasonic vibrations can be converted into radial vibrations using only one vibrator, deep drawing becomes possible. Furthermore, since this vibrating die can be replaced with another general die, this device can be used for processes other than deep drawing. [Example] Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the entire configuration of an ultrasonic machining apparatus showing one embodiment of the present invention, and FIG. 2 is an enlarged half-sectional view of the vibrating die portion of FIG. 1. As shown in these figures, the vibrating die 20 of this embodiment is
An annular hollow disk portion 22 having a die processing surface 21
The hollow disc part 22 has a shaft part 23 vertically protruding from a connecting part 24 at the center thereof, and vibrations are transmitted to the vibration die 20 via a connecting bolt 8 to this shaft part 23. A cone 7 is connected to the cone 7, and a vibrator 6 connected to an ultrasonic generator 9 and capable of generating ultrasonic vibrations in one-dimensional axial reciprocating motion is attached to the cone 7. Further, the vibrating die 20 is provided with a wrinkle presser 1 that can raise the punch 4 for deep drawing while inserting the raw plate 5 therebetween and applying ultrasonic vibration. Further, a control unit 12 that controls an electromagnetic valve 11 for supplying and stopping pressure oil of a hydraulic pump 10 is connected to the ultrasonic generator 9, and pressurizes the wrinkle presser 1 via the unit 12, and pressurizes the punch 4.
Pressure oil is supplied to and stopped from a hydraulic press (not shown) that raises the . Further, the wrinkle presser 1 and the punch 4 are provided with a load meter 14 equipped with a recorder 13. Note that 15 is a power source for the ultrasonic generator 9. In this embodiment, when designing the vibrating die 20, the resonance frequency of the shaft portion 23 and the hollow disc portion 2 are determined.
2, a resonance frequency at which the entire vibrating die 20 resonates simultaneously is determined. Ultrasonic vibration system used in the example, vibrator 6 and cone 7
The resonant frequency of is, for example, 14.45~15.05kHz,
The outer diameter and length of the shaft portion 23, the hollow disk portion 2
The inner and outer diameters, thickness, etc. of 2 are determined. Then, when the vibrator 6 is axially vibrated at this resonance frequency and the vibration is transmitted to the shaft portion 23 of the vibrating die 20 by the cone 7, the axial vibration of the shaft portion 23 is as shown by the dotted line in FIG. The vibration is converted into a radial vibration that concentrically expands and contracts in the hollow disc portion 22. Also, when restrained in the axial direction by the wrinkle presser 1,
The axial restraining force helps to some extent (about 10%) in converting the radial vibration, but the conversion itself from the axial vibration to the radial vibration is automatically performed by the vibrating die 20 itself as described above. It is carried out according to Therefore, this radial vibration is also transmitted to the blank 5 held between the die processing surface 21 of the vibrating die 20 and the wrinkle presser 1, and the blank 5 itself also vibrates. In this way, after the entire vibration system oscillates, pressurized oil from the hydraulic pump 10 is supplied to press the wrinkle presser 1 to apply a predetermined pressure to the flange portion of the blank plate 5, and then the punch 4 is raised to create a deep The drawing process is carried out, and when a predetermined drawing depth is reached, the control unit 1
The ultrasonic oscillation is stopped by the command from 2, and the solenoid valve 1
By closing 1, the wrinkle presser 1 is released,
Then, when the punch 4 is lowered, the machining is completed. Table 1 shows cases where deep drawing is performed using the vibrating die according to the present invention while applying ultrasonic vibration, and
The following shows a comparison of experimental results when machining is performed without vibration.

[Table] As is clear from Table 1, when the drawing depth is 7 mm, forming is possible in both processes, but when no vibration is applied, wrinkles appear on the side of the workpiece, and when the drawing depth is 19 mm, forming is possible. In some cases, molding cannot be performed without vibration, indicating that the molding limit has been greatly improved. In other words, the limiting drawing ratio (LDR) for aluminum with a plate thickness of 50 μm is 1.2 when no vibration is applied, but when using this vibrating die,
LDR=1.8, which is a significant improvement. Moreover, FIG. 4 shows the results of investigating the relationship between the wrinkle pressing pressure and the drawing depth for the same materials and plate thicknesses as above, in a graph. Figure 4a shows the wrinkle generation limit (broken line A) on the side surface of the workpiece when the vibrating die is vibrated with an amplitude of 14 μm, and Figure 4b shows the fracture limit (solid line B) and the wrinkle generation limit without vibration. The generation limit (broken line C) is shown. Note that no wrinkles were generated when the amplitude was 20 μm. As can be seen from FIG. 4b, when no vibration is applied, molding becomes impossible and wrinkles occur when the wrinkle pressing pressure exceeds 7 mm under all conditions. On the other hand, in the case of this vibrating die, deep drawing of 20 mm is possible under all conditions of the wrinkle presser pressure, and wrinkles do not occur if the wrinkle presser pressure is 0.05 kgf/mm ² or more. Next, since the vibrating die 20 is connected to the cone 7 supporting the vibrator 6, which is a vibration generation source, by a connecting bolt 8, the vibrating die 20 can be removed and attached to another vibrating die for processing. It is easy to replace, and this processing device can be used for purposes other than deep drawing. [Effects of the Invention] As described above, according to the present invention, it is possible to convert axial vibration into radial vibration using a vibrating die by using only one vibrator.
Deep drawing is easy, and the vibrating die is easy to replace, making this processing device versatile enough to be used for other processing as well.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the entire processing apparatus showing an embodiment of the present invention, Fig. 2 is an enlarged half-sectional view of the vibrating die, Fig. 3 is an explanatory diagram showing the resonance state of the vibrating die, and Fig. 4 This is a graph showing the relationship between wrinkle presser pressure and drawing depth. Figure a shows the case when the present vibrating die is used, and Figure b shows the case when no vibration is applied. FIG. 5 is a sectional view showing the main parts of a conventional ultrasonic processing device. DESCRIPTION OF SYMBOLS 1... Wrinkle presser, 4... Punch, 5... Raw plate, 6... Vibrator, 7... Cone, 8... Connection bolt, 9... Ultrasonic generator, 10... Hydraulic pump, 11... Solenoid valve, 1
2... Control unit, 13... Recorder, 14... Load cell, 15... Power supply, 20... Vibrating die, 21... Die processing surface, 22... Hollow disc part, 23... Shaft part, 24
...joint part. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A blank plate is sandwiched between a vibrating die and a wrinkle presser, and ultrasonic vibration is applied to make a one-dimensional axial reciprocating motion in a direction perpendicular to the machined surface of the vibrating die. A deep drawing method comprising drawing the blank using a punch passing through the center of the wrinkle holder while converting vibration into radial vibration that concentrically expands and contracts on the processing surface. 2. A vibrating die having an annular hollow disk portion having a die processing surface and a coaxial shaft portion perpendicular to the hollow disk portion, and a vibrating die that is removably connected to the shaft portion via a connecting bolt, and has an axial direction. A deep drawing device comprising: a cone for transmitting vibrations equipped with a vibrator that generates ultrasonic vibrations; and a cone for transmitting vibrations.