JP2611120B2 - Vibration / hydraulic drawing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The drawing method is a method of drawing a sheet metal into a die with a punch and drawing a seamless bottomed container. The present invention performs such drawing processing. Method and apparatus.

[0002]

2. Description of the Related Art FIG. 7 is a longitudinal sectional view of a conventional drawing apparatus, in which (1) shows a state before drawing and (2) shows a state immediately after drawing. At the time of drawing, first, as shown in FIG. 1 (1), the material plate 2 is placed on the die 1 fixed to the press machine, and the punch 4 is inserted into the die hole 5 with the material plate 2 being pressed by the wrinkle holder 3. Lower down. At this time,
With the lowering of the punch 4, as shown in FIG.
Squeezed into the die hole 5 and has a seamless bottom
2a is formed.

On the other hand, a method is known in which a hydraulic chamber 6 is formed in a die 1 and filled with a lubricating liquid in advance, as shown in FIG. . In this apparatus, the material plate 2 is narrowed down by the punch 4 into the hydraulic chamber 6 filled with liquid, whereby the hydraulic pressure in the hydraulic chamber 6 naturally rises, and the lubricating liquid is mixed with the material plate 2 and the die. 1, the friction in the flange portion 2f of the product is reduced, and the drawability is improved. That is,
He says that he can squeeze deeper with less processing power.

On the other hand, referred to as the ultrasonic vibrating, the mounting ultrasonic transducer 7 to each portion, the blank holder 3, applying ultrasonic vibration of the arrow a ₁ direction, the die 1, the arrow a ₂ direction of the ultrasonic concussion the punch 4, applying ultrasonic vibration of the arrow a ₃ direction, the blank holder 3, applying ultrasonic vibration of the arrow a ₄ direction, the die 1, applying ultrasonic vibration of the arrow a ₅ direction, It has also been proposed to reduce friction at the flange portion 2f of the product by using such a technique.

[0005]

However, in such a method of applying ultrasonic vibration, no improvement in drawability enough to deserve industrialization could be expected even if ultrasonic vibration was applied to any position and in any direction. . As above, in the case of a method of applying ultrasonic vibration of the arrow a ₃ directions punch 4 has been said and even counterproductive.

[0006] In the opposed hydraulic system in which the hydraulic chamber 6 is provided as described above, if the pressure of the liquid in the hydraulic chamber 6 is not considerably large, the lubricating liquid will not flow between the flange 2 f of the material plate 2 and the die 1. Do not get in the way. Therefore, 300 ~
An extremely large liquid pressure of 400 atm or 100 atm is required even for an aluminum plate. For example, even if the drawing force is 5 tons, the total working force can be as high as 50 tons. As a result, there are many problems such as the necessity of a press machine having a large capacity and the necessity of reinforcing the mold.

The technical problem of the present invention is to focus on such a problem and to improve the conventional molding method so as to be able to draw deeper with a smaller working force.

[0008]

FIG. 1 is a cross-sectional view for explaining the basic structure of a vibration and hydraulic drawing method and apparatus according to the present invention. A first aspect of the present invention resides in that the material plate 2 is placed on the die 1, and the material plate 2 is pressed by the wrinkle holder 3, and the punch 4 is inserted from above the material plate 2 into the die hole 5 communicating with the hydraulic pressure chamber 6. In the method of drawing the material plate 2 by inserting a hole, at least one of the punch 4, the die 1 and the wrinkle retainer 3, the load acting between the punch 4 and the material plate 2 during the processing is almost periodically changed. The drawing process is performed while applying a mechanical vibration having an amplitude and a period that can be set to zero.

In a second aspect of the present invention, the material plate 2 is placed on the die 1, and the material plate 2 is pressed by the wrinkle holder 3, and the die plate 5 is inserted into the die hole 5 communicating with the hydraulic pressure chamber 6. In the method of inserting the punch 4 from above and drawing the material plate 2, at least one of the punch 4, the die 1 and the wrinkle holder 3 has an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz.
Drawing while applying the mechanical vibration of

In a third aspect of the present invention, the blank 2 is placed on the die 1, and the blank 2 is held down by the wrinkle holder 3. In the method in which the punch 4 is inserted from above and the material plate 2 is drawn, mechanical vibration having an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz is applied to one of the punch 4 and the die 1.
Alternatively, drawing is performed while applying ultrasonic vibration to the wrinkle holder 3.

The material plate 2 is placed on the die 1, and the material plate 2 is held down by the wrinkle holder 3, and the material plate 2 is inserted into the die hole 5 communicating with the hydraulic pressure chamber 6. In the method of inserting the punch 4 from above and drawing the material plate 2, at least one of the punch 4, the die 1 and the wrinkle holder 3 has an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz.
The mechanical vibration is applied, and the drawing process is performed while controlling the pressure of the liquid in the hydraulic chamber 6 to be substantially constant until the processing is completed.

The material plate 2 is placed on the die 1, and the material plate 2 is held down by the wrinkle holder 3, and the material plate 2 is inserted into the die hole 5 communicating with the hydraulic chamber 6. A punch 4 is inserted into the blank 2 to draw the material plate 2, and at least one of the punch 4, the die 1, and the wrinkle holder 3 has an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz.
A vibration device for applying mechanical vibration is connected, and the liquid in the hydraulic chamber 6 contains a low-viscosity liquid having almost no lubricity.

[0013]

As described in claim 1, at least one of the punch 4, the die 1, and the wrinkle retainer 3 has an amplitude such that a load applied between the punch 4 and the material plate 2 periodically becomes substantially zero. When a periodic mechanical vibration is applied, the material plate 2 springs back at the moment when the applied load is reduced, and a minute gap is periodically generated between the die shoulder 1r and the material plate shoulder 2r. As a result, the lubricating liquid in the hydraulic chamber 6 can easily enter the minute gap, for example, 0.5 MPa (5 atm).
Sufficient lubrication can be obtained even with a small hydraulic pressure of
Friction force is reduced and drawability is significantly improved.

According to a second aspect of the present invention, during drawing, at least one of the punch 4, the wrinkle holder 3 and the die 1 is provided with a mechanical vibration having an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz. Is applied, the load acting between the punch 4 and the blank 2 can be reduced to almost zero.
Friction between 1r and the material plate shoulder 2r and between the die 1 and the flange 2f of the material plate 2 can be effectively reduced, and the drawing workability can be improved.

According to a third aspect of the present invention, one of the punch 4 and the die 1 has an amplitude of 0.5 mm or more and a frequency of 5 so that the load acting between the punch 4 and the material plate 2 becomes almost zero. When a mechanical vibration of ~ 80 Hz is applied and an ultrasonic vibration is applied to the other, the lubricating liquid can easily move between the material plate 2 and the die shoulder 1r by the low frequency mechanical vibration as described above. A gap is formed between the material plate 2 and the die 1 by the acoustic wave vibration, the lubricant can easily advance, and the friction between the material plate 2 and the die 1 can be reduced more efficiently.

According to a fourth aspect of the present invention, at least one of the punch 4, the die 1, and the wrinkle retainer 3 has an amplitude of 0.
Apply mechanical vibration of 5mm or more and frequency of 5 to 80Hz,
When the load acting between the punch 4 and the material plate 2 is reduced to almost zero and the pressure of the liquid in the hydraulic chamber 6 is controlled to be substantially constant until the end of machining, the liquid in the hydraulic chamber 6 is controlled. Unlike the conventional method in which the pressure gradually increases to an abnormally high pressure, a normal mold that does not use the opposing hydraulic pressure can be used. Also, the punch 4 is opposed to the hydraulic pressure in the hydraulic chamber 6.
The maximum punch force for lowering the pressure can be significantly reduced, and a press machine having a small capacity can be used.

According to a fifth aspect of the present invention, a mechanical vibration having an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz is applied to at least one of the punch 4, the die 1, and the wrinkle retainer 3. A vibration device is connected, and a low-viscosity liquid having almost no lubricity is contained as a liquid in the hydraulic chamber 6, so that various additives are added as in the prior art, and lubricity is improved. Since it is not necessary to use a high-viscosity oil, the burden of cleaning the product after drawing is reduced, and there is no need to use a special cleaning liquid, so there is no environmental pollution.

[0018]

Next, practical examples of how the vibration and hydraulic drawing method and apparatus according to the present invention are embodied will be described with reference to examples. FIG. 2 is an example of a drawing apparatus used in an experiment of the drawing method according to the present invention, and a wrinkle holder 3 is shown.
And the die 1 are shown in a sectional view.

In the apparatus shown in FIG. 2, a wrinkle holding force A is always uniformly applied to the blank 2 during drawing, and the wrinkle holding force A is always held down even when the thickness of the flange portion 2f fluctuates during the working. It is important to control the force to be constant. Therefore, the present device has a structure in which pressure is applied by eight pistons arranged concentrically on the wrinkle holder 3. Ring-shaped pistons are also commonly used, but have problems in terms of parallelism. Furthermore, an accumulator is incorporated in the middle of the hydraulic system for wrinkle control to absorb fluctuations in hydraulic pressure due to an increase in plate thickness during processing.

On the other hand, it is desirable that the opposing hydraulic pressure in the hydraulic chamber 6 of the die 1 can be maintained at a constant pressure during the drawing.
Therefore, the opposing hydraulic pressure is set to 0.5 MPa (5 atm) or more by a method such as incorporating an accumulator or attaching a relief valve also to the hydraulic system for adjusting the pressure in the hydraulic chamber 6.

[0021] the lower end of the die 1, through the member 11, the mounting ultrasonic transducers (R-L converter) 8, an ultrasonic vibration in the same direction as the axis of the punch 4 (arrow a ₁ direction) It is supposed to add. The power of the ultrasonic vibration device is 21 kHz, 2.
4 kW, about 3 μm between die 1 and blank 2
Is formed.

A load cell 10 for measuring a load acting on the punch 4 is mounted between the punch 4 and a hydraulic actuator 9 for driving the punch 4 up and down. The actuator 9 is used not only to move the punch 4 up and down, but also to apply low-frequency mechanical vibration to the punch 4. In the first embodiment, the mechanical vibration of the punch 4 was constant at an amplitude of 6 mm and a frequency of 32 Hz.

In this device, the die 1 has a die hole 5
Was 30 mm in inner diameter. Also, since a 0.6 mm thick aluminum plate (A5052) is used as the workpiece, the punch diameter is 28.4 mm in consideration of the clearance with respect to the inner diameter of the die.
And The clearance at this time is 1.3t (t is plate thickness)
Becomes As a lubricating liquid to be supplied to the hydraulic chamber 6, a low-viscosity paraffinic mineral oil (viscosity 15 cSt, 40 ° C.) was used.

FIG. 3 shows the maximum drawing force when drawing is performed using this test apparatus. Curve A in FIG. 3 represents curve B in the case where only the hydraulic pressure is applied by the hydraulic chamber 6.
When ultrasonic vibration is applied to the die 1 and hydraulic pressure is applied to the die 1 by the hydraulic pressure chamber 6, the curve C in FIG.
In addition, when the hydraulic pressure is applied by the hydraulic chamber 6, a curve D of ▲ indicates the case where the punch 4 is vibrated, the ultrasonic vibration is applied to the die 1, and the hydraulic pressure is also applied by the hydraulic chamber 6. . (A), when the processing speed is 1 mm / s, (b)
Is the case of 10 mm / s.

When only the opposing hydraulic pressure is applied as shown by the curve A, the maximum drawing force is the highest, and as shown by the curve B, when the ultrasonic vibration is applied to the die 1 with the opposing hydraulic pressure applied. The maximum drawing force is lower than in the case of only the opposing hydraulic pressure, and a certain effect is produced. In any case, the processing force is lower when the processing speed is 10 mm / s than when the processing speed is 1 mm / s.

On the other hand, when the punch 4 is vibrated at a low frequency as indicated by a curve C, the maximum drawing force is significantly reduced as compared with the curves A and B described above. The effect of the mechanical vibration is remarkably exhibited. When the processing speed is 1 mm / s or 10 mm / s, the opposing hydraulic pressure is 0.5M
It is effective when the pressure is Pa (5 atm) or more.

As shown by the curve D, when ultrasonic vibration is applied to the die 1 in addition to the low-frequency mechanical vibration of the punch 4, the maximum drawing force is reduced as compared with the case where only the mechanical vibration of the curve C is used. ing.

FIG. 4 is a stroke-working force diagram, in which the horizontal axis represents stroke (mm) and the vertical axis represents punch force (kN). In this figure, (a) shows the same conditions as in the case of the curve A,
That is, only the opposing hydraulic pressure is added. Since the punch 4 does not vibrate, the working force continuously increases and decreases, and the material plate is broken at the Z point. On the other hand, when the mechanical vibration of the punch 4 and the ultrasonic vibration to the die 1 are used together as shown in FIG. 3 (b), the punch 4 mechanically vibrates at a low frequency. Is declining. At the time when the maximum drawing force is decreasing, the force applied to the punch 4 from the actuator 9 is zero. As is clear from this figure, when low-frequency mechanical vibration is applied to the punch 4, the material plate does not break, and the effect of reducing the maximum drawing force is remarkable.

FIG. 5 shows the results of measurement of the limiting drawing ratio with the limit of the case where five blanks were drawn under the above-mentioned conditions A to D and all the sheets were drawn without breaking any of them.
(A) As shown in the figure, when the processing speed was 1 mm / s, under the conditions A and B in which low-frequency mechanical vibration was not applied to the punch, all the material plates broke. C with mechanical vibration applied to punch 4
Under the condition (1) and the condition (D) with the addition of ultrasonic vibration, as the opposing hydraulic pressure increases to 0.5 MPa or more, the limit throttle ratio increases.

When the working speed is 10 mm / s, the limit drawing ratio is extremely small under the conditions A and B where the punch is not mechanically vibrated. This is because the aluminum plate (A5052) as the raw material plate is a material that is very difficult to be drawn, and a lubricating liquid having low viscosity and poor lubricity such as spindle oil is used.

On the other hand, under the condition C where mechanical vibration is applied to the punch 4 and the condition D where ultrasonic vibration is further applied, the limit throttle ratio is remarkably improved, and the opposing hydraulic pressure is increased.
It is improved as it increases to 0.5 MPa or more.

As is clear from the above embodiment, applying low frequency mechanical vibration to the punch is extremely effective in improving drawability.

FIG. 6 shows the results of an examination of the influence of the frequency and amplitude of the punch when the drawing speed was set to 1 mm / s. This is the case where the material plate is broken. (a) shows the case where the diameter of the material plate is 50 mm, (b) shows the case where the diameter is 52 mm, (c) shows the case where the diameter is 54 mm, and (d) shows the case where the diameter is 56 mm. In the drawing, the larger the material plate, the more easily the material is broken.

(A) As shown in the figure, when the diameter of the material plate is 50 mm, the mechanical vibration frequency applied to the punch is 5 to 60 Hz.
In the case where the amplitude is 1 mm to 15 mm, the drawing process is successful. In addition, as shown in FIG.
In the case of, the mechanical vibration frequency applied to the punch is 5-80H
At z, when the amplitude is 1 mm to 15 mm, the drawing process is successful. (C) As shown in the figure, when the diameter of the material plate becomes 54 mm, the mechanical vibration frequency applied to the punch is 5 to 70 Hz.
In the case where the amplitude is 2 mm to 15 mm, the drawing process is successful. (D) As shown in the figure, when the diameter of the material plate is further increased to 54 mm, the mechanical vibration frequency applied to the punch becomes 5 to 5.
At 70 Hz and an amplitude of 4 mm to 15 mm, drawing was successful. In addition, the case where the amplitude exceeds 15 mm has not been tested, but as is clear from these results, the case where the amplitude is 15 mm or more is effective.

Therefore, depending on the thickness of the blank, if the mechanical frequency of the punch is 0.5 to 80 Hz and the amplitude is 0.5 or more, the drawing can be performed smoothly.

In each of the above embodiments, low-frequency mechanical vibration is applied to the punch 4. However, when low-frequency mechanical vibration is applied to the die 1 and the wrinkle holder 3, the flange 4
Between 2f and die 1 and die shoulder 1r and material plate shoulder 2r
It is considered that mechanical vibration is relatively generated between the above and the drawability is improved.

[0037]

According to the first aspect, the punch 4 and the die 1 are provided.
When mechanical vibration is applied to at least one of the wrinkle retainers 3 so that the load applied to the punch 4 periodically becomes almost zero, and the amplitude and the period of the mechanical vibration, the distance between the die 1 and the flange portion 2f of the material plate is increased. And die shoulder 1r and material plate shoulder
A gap is effectively generated between the lubricating fluid 2r and the lubricating fluid in the hydraulic pressure chamber 6. As a result, a sufficient lubricating effect can be obtained even with a small liquid pressure of about 0.5 MPa or more, and the drawing workability is remarkably improved.

According to a second aspect of the present invention, at least one of the punch 4, the wrinkle holder 3 and the die 1 has an amplitude of 0.3.
When drawing is performed while applying mechanical vibration having a frequency of 5 mm or more and a frequency of 5 to 80 Hz, the load acting between the punch 4 and the material plate 2 can be periodically reduced to almost zero. Between flange 2f and die shoulder 1r and material plate shoulder
Friction between 2r can be effectively reduced and drawability can be reliably improved.

When low-frequency mechanical vibration is applied to a punch or the like and ultrasonic vibration is applied to the other, the low-frequency mechanical vibration causes a gap between the flange portion 2f of the material plate and the die 1. A gap is easily formed, and the lubricating liquid that has entered the gap easily advances due to the formation of the gap between the material plate 2 and the die 1 by ultrasonic vibration. Friction is reduced more efficiently.

When the low frequency mechanical vibration is applied and the pressure of the liquid in the hydraulic pressure chamber 6 is kept constant until the processing is completed by using an accumulator or a relief valve, the opposite hydraulic pressure is obtained. Can be reduced to 1/10 to 1/50 of the conventional one, and the maximum drawing force can be significantly reduced. Therefore, there is no need to reinforce the mold as in the past, and the use of a press machine with a small pressing capacity is required. Becomes possible.

When the low-frequency mechanical vibration is applied as described above, the lubricating liquid can move smoothly between the die 1 and the flange 2f of the material plate and between the die shoulder 1r and the material plate shoulder 2r. An extremely low viscosity liquid can be used as the liquid.
As a result, a vibration device for applying low-frequency mechanical vibration is connected as in the device of claim 5, and furthermore, in the hydraulic chamber 6,
By adopting a configuration in which a low-viscosity liquid having almost no lubricity is contained, cleaning of the product after drawing is simplified, and the concern of environmental pollution is eliminated because a special cleaning liquid is not required.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a basic configuration of a vibration and hydraulic drawing method and apparatus according to the present invention.

FIG. 2 is an example of a drawing apparatus used in an experiment of a drawing method according to the present invention, in which a blank holder 3 and a die 1 are shown in a cross-sectional view.

FIG. 3 shows the measurement results of the maximum drawing force when drawing is performed under various conditions using this test apparatus.

FIG. 4 is a stroke-working force diagram.

FIG. 5 shows a result of measuring a limit drawing ratio in a case where the material plates are drawn five by five under the above-mentioned conditions A to D.

FIG. 6 is a result of examining the influence of the vibration frequency and amplitude of the punch when the drawing speed is 1 mm / s.

FIG. 7 is a longitudinal sectional view of a conventional drawing apparatus, (1)
Is a state before drawing, and (2) is a state immediately after drawing.

FIG. 8 is a longitudinal sectional view of a conventional opposed hydraulic type drawing apparatus.

[Explanation of symbols]

 Reference Signs List 1 die 1r die shoulder 2 material plate 2r material plate shoulder 2f material plate flange 3 wrinkle holder 4 punch 5 die hole 6 hydraulic chamber 7 ultrasonic vibrator 8 ultrasonic vibrator 9 actuator 10 load cell 11 member

Claims (5)

(57) [Claims] 1. A material plate 2 is placed on a die 1, and while the material plate 2 is pressed by a wrinkle holder 3, a punch 4 is placed from above the material plate 2 into a die hole 5 communicating with a hydraulic pressure chamber 6. In the method of drawing the material plate 2 by inserting the punch, at least one of the punch 4, the die 1 and the wrinkle retainer 3 periodically receives a load that acts between the punch 4 and the material plate 2 during the processing. A vibration / hydraulic drawing method characterized by applying a mechanical vibration of an amplitude and a period that can be brought to a state of zero. 2. A material plate 2 is placed on a die 1 and a blank 4 is pressed from above the material plate 2 into a die hole 5 communicating with a hydraulic pressure chamber 6 while the material plate 2 is pressed by a wrinkle holder 3. In the method of drawing the material plate 2 by inserting a material, at least one of the punch 4, the die 1, and the wrinkle holder 3 is provided with mechanical vibration having an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz. A vibration / hydraulic drawing method characterized by adding. 3. A material plate 2 is placed on a die 1 and a blank 4 is pressed from above the material plate 2 into a die hole 5 communicating with a hydraulic pressure chamber 6 while the material plate 2 is held down by a wrinkle holder 3. In the method of drawing the material plate 2 by inserting a hole, a mechanical vibration having an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz is applied to one of the punch 4 and the die 1, and the die 1 or wrinkle holding is performed. 3. A vibration / hydraulic drawing method characterized by applying ultrasonic vibration to 3. 4. A material plate 2 is placed on a die 1 and a blank 4 is pressed from above the material plate 2 into a die hole 5 communicating with a hydraulic pressure chamber 6 while the material plate 2 is pressed by a wrinkle holder 3. In the method of drawing the material plate 2 by inserting a material, at least one of the punch 4, the die 1, and the wrinkle holder 3 is provided with mechanical vibration having an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz. In addition, the vibration / hydraulic drawing method is characterized in that the pressure of the liquid in the hydraulic chamber 6 is controlled to be substantially constant until the processing is completed. 5. A material plate 2 is placed on a die 1 and a blank 4 is pressed from above the material plate 2 into a die hole 5 communicating with a hydraulic pressure chamber 6 while the material plate 2 is held down by a wrinkle holder 3. A mechanical vibration having an amplitude of 0.5 mm or more and a frequency of 5 to 80 Hz is applied to at least one of the punch 4, the die 1, and the wrinkle retainer 3. A vibrating / hydraulic drawing apparatus, wherein an additional vibrating device is connected, and a low-viscosity liquid having almost no lubricity is contained as the liquid in the hydraulic chamber 6.