JP2003340563A - Ultrasonic molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required until a solid body being subjected to ultrasonic excitation is pulled up after submerged into a liquid so as to realize a technology which can complete ultrasonic molding in a short time. <P>SOLUTION: A cope 20 is subjected to ultrasonic excitation with great power while the cope 20 is submerged in molten metal 42. The ultrasonic power given to the cope 20 is decreased before the cope 20 is pulled up from the molten metal 42 and the amount of the molten metal 42 pulled up clinging to the cope 20 is adjusted according to the volume of the molding space. This allows the molten metal 42 containing impurities a little to touch the cope 20 in a short time, even in the event that the ultrasonic power to be given to the cope 20 needs to be limited to a small value when the cope 20 is pulled up from the molten metal 42, and does not cause defective molding even if the cope 20 is pulled up from the molten metal 42 in a short time. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to improvement of an ultrasonic molding method.

[0002]

The present inventors have discovered that when a solid is submerged in a liquid while being subjected to ultrasonic vibration and then pulled up, a phenomenon in which a large amount of the liquid is attached to the solid can be obtained. When this phenomenon is utilized, the solid space on which the liquid adheres is pressed against the mold to define a molding space between the solid and the mold, the liquid adhered to the solid is confined in the molding space, and the liquid is enclosed in the molding space. When is solidified, a molded product having an intended shape is obtained. If the solid to which the ultrasonic vibration is applied is a mold, a molded body made of a liquid material is molded by releasing the mold after molding. If the solid to which ultrasonic vibration is applied is the base material, a composite body in which a formed body formed of a liquid material is in close contact with the base material is formed. The method of pulling up the solid while applying ultrasonic vibration to the solid, pressing the solid on which a large amount of the liquid adheres to the mold, and solidifying the liquid in the molding space to mold the solid is called ultrasonic molding technology.

In a usual molding technique, since a molding space is filled with a liquid for molding, filling failure may occur depending on the molding shape. In the ultrasonic molding method, a liquid is attached in advance to a solid (often a mold) that defines one side of the molding surface, and then the liquid is pressed against the other mold for molding, so that defective filling is unlikely to occur. The ultrasonic molding method has great potential because it can solve other problems found in existing molding methods such as the injection molding method.

[0004]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention According to the research conducted by the present inventors, a predetermined time is required from the immersion of an ultrasonically excited solid in a liquid to the lifting thereof, and before the required time elapses. It has become clear that defective molding tends to occur when pulled up. That is, it has been found that the amount of adhered liquid is insufficient to cause defective molding, or the component of the adhered liquid deviates from the intended component to cause defective molding.

The ultrasonic molding method of the present invention comprises the steps of submerging the ultrasonically excited solid into the liquid and then pulling it up to attach the liquid to the solid, and the molding formed between the solid and the mold. Trapping the liquid adhering to the space to solidify the liquid. It has been confirmed that the amount of liquid adhering to the pulled-up solid changes depending on the power of ultrasonic waves applied to the solid when the liquid is pulled out of the liquid. Therefore, the power of the ultrasonic waves to be applied to the solid when pulled out from the liquid is determined by the volume of the molding space (that is, the wall thickness of the molded body). According to the research conducted by the inventors of the present invention, a phenomenon in which the amount of liquid adhered is insufficient to cause defective molding or the component of the adhered liquid deviates from an intended amount to cause defective molding is mainly caused by It has been found that it occurs when the power of the ultrasonic waves to be applied to the solid to deposit a liquid (comparable to the volume of the space) is small (typically when the volume of the molding space is small). When the power of the ultrasonic waves applied to the solid is small, it takes a long time to sink the solid into the liquid and then pull it up. The present invention has been studied in order to realize a technique capable of completing the ultrasonic molding in a short time by shortening the time required for the ultrasonically excited solid to be submerged in the liquid and then lifted.

[0006]

Means and Actions for Solving the Problems The present inventors have
We studied the meaning of the time it takes to immerse a ultrasonically excited solid into a liquid and then pull it up. As a result, the following phenomena have become known.

(1) Oxides and foreign substances often float on the surface of the liquid that is the molding material. In particular, the liquid surface where the metal is melted is often covered with an oxide film. (2) When the ultrasonically excited solid is submerged in the liquid,
Initially, an oxide film, a foreign material layer, gas, etc. are present between the solid and the liquid. (3) When the ultrasonically excited solid is submerged in the liquid, the oxide film, the foreign material layer, the gas, etc. existing between the solid and the liquid are separated from the ultrasonically excited solid. As a result, the oxide film, the foreign material layer, and the intervening layer such as gas disappear, and the liquid containing few impurities comes into contact with the solid. (4) It is important to wait until this point before pulling up the solid, and if the solid is pulled up and molded before that, the amount of adhered liquid will be insufficient and molding defects will occur, or liquids containing oxides, foreign matter, or gas mixed Since it is used for molding, defective molding is likely to occur. (5) When the power of ultrasonic waves to be applied to a solid in order to deposit an appropriate amount of liquid is small, the time taken until the event of (3) is obtained as compared with the case where a large power is applied to the solid. Tend to prolong.

From the above understanding, when the power of the ultrasonic wave applied to the solid is small (typically, when the volume of the molding space is small), the solid before the event (3) is obtained. It has been found that molding defects are likely to occur from the pulling up of. Moreover, when the power of the ultrasonic wave applied to the solid is small, the phenomenon that the molding material in the molding space is not properly melted easily occurs. This may cause defective molding. Therefore, in the ultrasonic molding method, it is important to change the power of the ultrasonic waves applied to the solid in accordance with the progress of the process, and it was confirmed that by appropriately changing the power, it is possible to complete high-quality molding in a short time.

In particular, while being submerged in a liquid, the solid is ultrasonically vibrated with a large power, and the power of the ultrasonic wave applied to the solid before being pulled out of the liquid is reduced. It was confirmed that it was effective to pull out from the liquid. According to this method, even if it is necessary to keep the adhesion amount small because the volume of the molding space is small, the liquid with few impurities will come into contact with the solid in a short time, and even if the solid is pulled up in a short time, molding failure will occur. Do not invite

Effective results can also be obtained by varying the power of ultrasonic waves applied in the step of solidifying the liquid that has been pulled up by following the progress of solidification. Usually, it is preferable to make the power of ultrasonic waves applied at the initial stage of solidification higher than at the latter stage of solidification. In the initial stage of solidification, by adding a large power, the density of the crystal to be solidified can be improved and the gas can be removed, so that a high-quality molded product can be obtained.
The power of the ultrasonic waves applied at the initial stage of solidification can be made larger than the power of the ultrasonic waves applied to the solid when it is pulled out from the liquid. Further, the stress applied to the solidified portion can be reduced by reducing the power in the latter stage of solidification. The ultrasonic vibration may be stopped in the latter step of solidification. In the solidification step, the power of ultrasonic waves applied to the solid pulled up from the liquid may be adjusted, or the power of ultrasonic waves applied to the mold that faces the solid and defines the molding space may be adjusted. Alternatively, ultrasonic vibration may be applied separately, or ultrasonic vibration may be applied so that both vibrate integrally.

When the solid drawn from the liquid is a mold, it is necessary to release the molded product from the mold. In this case, it is preferable to release the molded body while ultrasonically vibrating the mold. When ultrasonic vibration is applied to the mold, the liquid is attached, while the solid (here, the molded body) is peeled off. If ultrasonic vibration is applied to the mold after the liquid has solidified, it may be possible to release the mold without preparing an extrusion pin, etc., and the extrusion force is reduced even when an extrusion pin etc. is required. The molded body is not damaged.

The ultrasonic molding method of the present invention can be applied to various materials that can be solidified in a liquid state and solidified in the molding space. Examples of such a material include materials such as metal, thermoplastic resin, paraffin wax, and glass which become liquid by heat, and thermosetting resin before reaction curing. Further, a material in which a powder of ceramics such as alumina, silicon carbide or boron carbide, or a powder of a refractory metal or an intermetallic compound is dispersed using these as a matrix may be used.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is also characterized by being embodied in the following modes.

(Mode 1) By changing the amplitude of ultrasonic vibration, the power of the ultrasonic wave applied to the solid is changed in accordance with the progress of solidification. Generally, the power of ultrasonic waves can be changed by changing at least one of amplitude and frequency. Generally, the ultrasonic vibration device has a configuration in which the amplitude of the ultrasonic vibration is easier to adjust (change more easily) than the frequency. Therefore, in the molding method of the present invention, it is suitable that the frequency of ultrasonic vibration is kept substantially constant, and the power of ultrasonic waves is changed by changing the amplitude according to the progress of the process.

(Mode 2) The liquid material attached to the solid is a molten metal. In such cases, molten metal (molten metal)
The liquid surface of is often covered with an oxide film, and it tends to take a long time to peel off the oxide film from the solid submerged in the molten metal. Therefore, the effect obtained by applying the present invention (the effect of shortening the time required from the immersion of the ultrasonically excited solid in the liquid to the pulling up) is great.

(Mode 3) The power of the ultrasonic waves when the solid is immersed in the liquid is 1.2 times or more (more preferably 1.5 times) the power of the ultrasonic waves applied to the solid when the liquid is pulled up from the liquid. And above). As a result, the time required for the solid to be pulled up after being immersed in the liquid can be significantly shortened.

[0017]

EXAMPLES A molding example to which the molding method of the present invention is applied and an experimental example related to the molding method will be described below. The schematic structure of the molding apparatus used is shown in FIG. As illustrated, the ultrasonic vibrator 10 includes an oscillator 12 and a horn 14 that are integrated with each other, and an ultrasonic oscillation source 16 connected to the oscillator 12. The horn 14 is fixed to the upper die 20, whereby the vibrator 12, the horn 14, and the upper die 20 are fixed.
Are integrally movable up and down. The amplitude of ultrasonic vibration generated from the ultrasonic oscillation source 16 can be changed within a predetermined range at any time. This makes upper mold 2
The power of the ultrasonic wave added to 0 can be adjusted arbitrarily. In the molding apparatus used here, the total amplitude of the horn 14 (which means the entire width of displacement of the horn due to ultrasonic vibration) can be arbitrarily changed within a range of approximately 0 to 50 μm. On the other hand, the molten metal tank 40 holds a molten metal 42 as a molding material. Using a hydraulic piston, etc.
By moving the upper die 20 up and down together with the vibrator 12 and the horn 14, the upper die 20 can be immersed or pulled up in the molten metal 42.

A molded body can be produced using the molding apparatus having the above-mentioned structure, for example, as follows. That is, as shown in FIG.
0 is submerged in molten metal 42. When the upper mold 20 is pulled up from the molten metal 42 while continuously applying ultrasonic vibration, a part of the molten metal 42 is attached (sucked) to the upper mold 20 and pulled up, as shown in FIG. While maintaining the ultrasonic vibration of the upper mold 20, as shown in FIG.
Is pressed against the lower mold 30 (mold matching). This allows
The molten metal 42 is enclosed in a molding space defined between the upper mold 20 and the lower mold 30. In this state, the molten metal 42 is cooled and solidified. Then, open the mold as shown in FIG.
The molded body 44 formed by solidifying 2 is removed from the upper mold 20. Ultrasonic vibration of a predetermined total amplitude (variable) can be applied to the upper mold 20 at any time during the above manufacturing process.

In such a manufacturing method, the amount of the molten metal 42 attached to the upper die 20 and pulled up (adhered amount) so that an amount of the molten metal 42 corresponding to its volume is confined in the molding space.
Adjust. This amount of adhesion changes depending on the power of the ultrasonic waves applied to the upper die 20 when the upper die 20 is pulled up from the molten metal 42, if other main conditions are similar.
The relationship is also shown in the result of an experiment conducted using a device configured as in FIG. 1 and using silicone oil instead of the molten metal 42. The experimental results are shown in FIG. Figure 6
As can be seen, as the total amplitude of the horn fixed to the upper mold is increased, the amount of silicone oil attached tends to increase. As can be seen from FIG. 6, this adhesion amount is determined by the viscosity of silicone oil (eg, kinematic viscosity coefficient (cSt)).
It also depends on the above), and the adhesion amount tends to increase as the viscosity decreases.

Using the apparatus shown in FIG. 1, a temperature of 650 ° C.
Molding Example 1 was carried out in which a molded body A having a predetermined shape was produced from the molten metal of the Mg-Al-Zn alloy AZ91D held at. Further, Molding Examples 2 to 6 in which a molded body B having a volume different from that of the molded body A was produced using the same molten metal were carried out. In these molding examples, the upper mold was vibrated by applying longitudinal ultrasonic vibration (resonance frequency: 20 kHz) to the horn. The preheating temperature of the upper mold when the upper mold was submerged in the molten metal was 350 ° C.

<Molding Example 1: Example of constant ultrasonic power (1)> The upper mold, which is ultrasonically vibrated with a total amplitude of 16 μm, is immersed in the molten metal for 3 seconds and vibrated with a total amplitude of 16 μm. While pulling out from the molten metal. Amplitude of the upper mold with molten metal attached is 1
While continuously vibrating at 6 μm, the lower mold was matched with the lower mold, and in this state, the molten metal in the molding space was cooled and solidified. The upper mold was vibrated continuously with a total amplitude of 16 μm until the beginning of solidification, and then stopped. After solidification is completed, the mold is opened and the total amplitude is 16
The molded body was released from the mold while vibrating the upper mold with a thickness of μm. According to this molding example, a high-quality molded product having no defective molding was obtained.

<Molding Example 2: Example in which the power of ultrasonic waves is constant (2)> The upper mold, which is ultrasonically excited with a total amplitude of 10 μm, is immersed in the molten metal for 10 seconds, and is agitated with a total amplitude of 10 μm. While pulling out from the molten metal. The upper mold to which the molten metal adhered was matched with the lower mold while continuously vibrating at a total amplitude of 10 μm, and in this state, the molten metal in the molding space was cooled and solidified. The upper mold was vibrated continuously at a total amplitude of 10 μm until the beginning of solidification, and then stopped. After solidification is completed, the mold is opened and the total amplitude is 1
The molded body was released from the mold while vibrating the upper mold at 0 μm. According to this molding example, a high-quality molded product having no defective molding was obtained.

<Molding Example 3: Example in which the power of ultrasonic waves is constant (3)> Except that the time for submerging the upper mold (excited with a total amplitude of 10 μm) in the molten metal is changed from 10 seconds to 3 seconds. A molded body was produced in the same manner as in Molding Example 2. Molding defects were found in the molded body obtained in this molding example.

<Molding Example 4: Example of varying ultrasonic power (1)> The upper die, which is ultrasonically excited with a total amplitude of 16 μm, is immersed in the molten metal for 3 seconds to reduce the total amplitude to 10 μm. Then, the upper mold was pulled out of the molten metal. In all other respects, a molded body was produced in the same manner as in Molding Example 2. According to this molding example, a high-quality molded product having no defective molding was obtained.

<Molding Example 5: Example (2) in which the power of ultrasonic waves was changed> The same procedure as in Molding Example 4 was performed from the time the sub-mold was immersed in the molten metal until the mold was pulled up.
While continuing to vibrate, I matched the mold with the lower mold. The upper mold was vibrated with a total amplitude of 16 μm at the initial stage of solidification, and then the vibration was stopped. In all other respects, a molded body was produced in the same manner as in Molding Example 2. With this molding example, a molded body of higher quality than that of molding example 4 was obtained.

<Molding Example 6: Example (3) in which the power of ultrasonic waves was changed> The same procedure as in Molding Example 2 was performed from the time the sub-mold was submerged in the molten metal until it was pulled up.
While continuing to vibrate, I matched the mold with the lower mold. The upper mold was vibrated with a total amplitude of 16 μm at the initial stage of solidification, and then the vibration was stopped. In all other respects, a molded body was produced in the same manner as in Molding Example 2. With this molding example, a molded body of higher quality than that of molding example 2 was obtained. For each of the above molding examples, Table 1 collectively shows the time (immersion time) for submerging the upper mold in the molten metal, the total amplitude of ultrasonic vibration in each step, and the type of molded body to be manufactured.

[0027]

[Table 1]

The results of Molding Examples 1 to 4 show that by increasing the total amplitude when the upper mold is submerged in the molten metal, a good molded product can be obtained even if the upper mold is pulled up in a short time. The time required to remove the oxide film, gas, etc. from the surface of the upper mold submerged in the molten metal (to optimize the composition and amount of the molten metal attached to the upper mold and pulled up) is the ultrasonic wave applied to this upper mold. As the power of (the total amplitude here) increases, it tends to become shorter. After that, when the upper die is pulled up from the molten metal, the upper die is vibrated with a total amplitude so that the amount of the adhered material corresponds to the volume of the molding space. Therefore,
When the power of ultrasonic waves to be applied to a solid in order to deposit an appropriate amount of liquid as in molding example 4 is relatively small,
In order to adjust the adhesion amount, the total amplitude is reduced and then the upper die is pulled up. In the step of adhering a liquid (here, molten metal) to a solid (here, upper mold), by varying the total amplitude of ultrasonic vibrations applied to the solid in this way, the molten metal can be applied to the upper mold regardless of the volume of the molding space. The ultrasonic molding can be completed in a short time by shortening the time from submersion to pulling up.

Further, as can be seen from the comparison between Molding Example 4 and Molding Example 5 and the comparison between Molding Example 2 and Molding Example 6, when vibrating with a large total amplitude in the initial stage of solidification, the denseness of the metal crystal solidified. The quality of the molded body can be further improved by improving the degree of discharge and facilitating the escape of gas.

In the above-mentioned molding example, the ultrasonic vibration was carried out until the initial solidification, but the vibration was stopped, but the vibration may be continued until the solidification further progresses. In this case, it is preferable to gradually or stepwise reduce the total amplitude as the solidification progresses. Further, when the molded body is released from the mold, the larger the total amplitude of the ultrasonic vibration applied to the mold, the faster and surely the mold release can be performed. Until the upper mold pulled up from the molten metal is matched with the lower mold, it is preferable to maintain a total amplitude equal to or more than the total amplitude when the upper mold is pulled up from the molten metal. By increasing the total amplitude after pulling up the upper mold from the molten metal, it is possible to enhance the effect of degassing the molten metal that is attached to the upper mold and pulled up.

The preferable range of the power of the ultrasonic wave applied when the solid (upper mold) is immersed in the liquid material depends on the properties (eg viscosity, specific gravity) of the liquid material. Although not particularly limited, when the liquid material is a general molten metal such as a magnesium alloy (typically AZ91D) or an aluminum alloy (typically ADC12), the resonance frequency is, for example, about 20 kHz. In this case, by ultrasonically exciting the solid with a total amplitude of 15 μm or more (typically 15 to 50 μm), the effect of shortening the time required for the solid to be submerged in the liquid and then pulled up becomes remarkable. Total amplitude 20 μm or more (typically 20 to 50 μm
A higher effect can be obtained by vibrating with m).
The direction of ultrasonic vibration applied to the solid is not particularly limited. The frequency of the ultrasonic vibration (resonance frequency) may be the frequency of the generally used ultrasonic wave, for example, 3 to 40 kH.
A range of z can be used.

In the following Experimental Examples 1 to 3, the time from when the ultrasonically excited solid (mold or the like) is immersed in the molten metal until the oxide film or the like is peeled off from the surface of the submerged solid. I tried to measure.

<Experimental Example 1> M kept at a temperature of 650 ° C.
A molten metal of the g-Al-Zn alloy AZ91D was prepared. A cylindrical mold having a diameter of 40 mm was preheated to 350 ° C., and the lower end thereof was immersed in the molten metal while ultrasonically vibrating at a resonance frequency of 20 kHz and a total amplitude of 16 μm. The temperature near the contact interface between the mold and the molten metal was continuously measured, and it was judged that the oxide film or the like had been peeled off from the mold when the temperature greatly changed.
In this experimental example, the time from when the mold was submerged in the molten metal until the oxide film was peeled off was about 1.6 seconds.

<Experimental Example 2> The time until the oxide film was peeled off was measured in the same manner as in Experimental Example 1 except that the preheating temperature of the mold was 400 ° C. In this experimental example, the time until the oxide film was peeled off was about 1.3 seconds.

<Experimental Example 3> The time until the oxide film was peeled off was measured in the same manner as in Experimental Example 1 except that the preheating temperature of the mold was set to 300 ° C. In this experimental example, the time until the oxide film was peeled off was about 5 seconds.

The results of Experimental Examples 1 to 3 show that the time required for the ultrasonically excited solid (mold or the like) to be pulled up after being submerged in the liquid (molten metal or the like) The time required to optimize the composition and amount)
It is shown that this can be shortened by increasing the preheating temperature of the solid. By increasing the preheating temperature of this solid in addition to increasing the total amplitude applied to the solid submerged in the liquid, the time required to submerge the ultrasonically excited solid into the liquid and pull it up is further shortened. can do. As a result, a good quality molded product can be produced in a short time.

The phenomenon that occurs when the mold is submerged in the molten metal can be read from the time-temperature chart as shown in FIG. 10, for example. In FIG. 10, T _Mg is the transition of the temperature of the molten metal (here, AZ91D alloy) prepared in the crucible, and T _mold is the transition of the temperature of the die (here, the die preheated to 400 ° C. was used). , T _s1.0 is the temperature change of the molten metal 1 mm below the end face (bottom face) of the submerged mold, and T _s0.5 is the molding 0.5 mm from the end face (bottom face) of the mold. The changes in the temperature of the material (adhered molten metal) are shown. Further, the horizontal axis of FIG. 10 shows the elapsed time before and after the time in seconds by setting the time when the mold is submerged in the molten metal as 0. Here, the time from immersion of the mold in the molten metal to pulling it up (immersion time t1) was set to 10 seconds. Also,
The mold was ultrasonically excited under the conditions of a resonance frequency of 20 kHz and a total amplitude of 9.6 μm. As shown in FIG. 10, the temperature changes when the ultrasonically excited mold is submerged in the molten metal, the oxide film is destroyed (a), the foreign matter is removed (b), and the quality is improved (molten metal cleaning).
The progress of (c) can be read.

<Experimental Example 4> The state of the liquid when the ultrasonically excited solid was submerged in the liquid was observed. As a liquid,
A dispersion liquid in which flaky aluminum powder was dispersed in methanol was used. At the lower end of the same mold used in Experimental Examples 1 to 3, the resonance frequency was about 19.5 kHz and the total amplitude was 6 μm.
When submerged in this dispersion while applying ultrasonic vibration, a flow toward the mold is generated in the dispersion, and the dispersion that was near the interface with the mold earlier is pushed outward by the dispersion that flows in later. The phenomenon of being done was observed. The left half of FIG. 7 is a photograph showing the state (the movement of the flake-shaped aluminum powder is seen as a white line), and the right half is a schematic diagram showing the flow of the dispersion liquid. It is presumed that the mold is "washed" by such a flow of the dispersion liquid, and the oxide film and the like that are present between the mold and the dispersion liquid are removed.

<Experimental Example 5> Mg-Al-Zn alloy AZ
For 91D, the relationship between the temperature of the molten metal and the amount of deposit was examined. The same mold used in Experimental Examples 1 to 3 is 673K.
It was preheated to (about 400 ° C.), and its lower end was immersed in the molten metal held at a predetermined temperature for 10 seconds while being ultrasonically excited at a resonance frequency of 20 kHz and a total amplitude of 15 μm. Then the total amplitude 1
The mold was pulled up from the molten metal while maintaining 5 μm, and the mass of the molten metal attached to the mold and pulled up was measured. FIG. 8 shows the relationship between the molten metal temperature and the deposition amount obtained as a result.

As can be seen from FIG. 8, the molten metal temperature is 870K.
Adhesion amount increases as it gets higher from near, 923K
It becomes maximum near (about 650 ° C). When the temperature of the molten metal further increases, the amount of the deposits slightly decreases, but it is almost flat in the temperature range above 940K. AZ91 used here
The solid-liquid coexistence region of D alloy is a temperature range of approximately 870 K or less (liquidus temperature 871 K and solidus temperature 693 to 708 K).
Temperature range between and). That is, in this solid-liquid coexistence region, the amount of AZ91D alloy deposited increases compared to the lower temperature region.

For this AZ91D alloy, the relationship between the total amplitude of the mold and the mass of the molten metal attached to the mold and pulled up was examined. That is, the same mold as above is 673K
While preheating to (about 400 ° C) and ultrasonic vibration at a resonance frequency of 20 kHz and a predetermined total amplitude, 923 K (about 650
1) at the bottom of the AZ91D alloy melt maintained at
It sank for 0 seconds. Then, the mold was pulled up from the molten metal while maintaining the same total amplitude as when it was submerged in the molten metal, and the mass of the molten metal pulled up by adhering to the mold was measured. The relationship between the total amplitude and the adhered amount obtained as a result is shown in FIG.

As can be seen from FIG. 9, the amount of molten metal adhered to the mold is determined depending on the ultrasonic power (here, the total amplitude) applied to the solid when the liquid is pulled up from the liquid.
The characteristics may differ depending on the type of liquid (molten metal), as shown in the schematic shapes of FIGS. 6 and 8, for example.

Specific examples of the present invention have been described above in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Further, the technical elements described in the present specification or the drawings are
The technical usefulness is exhibited alone or in various combinations, and is not limited to the combinations described in the claims at the time of filing. In addition, the technique illustrated in the present specification or the drawings achieves a plurality of purposes at the same time, and achieving the one purpose among them has technical utility.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a schematic configuration of a molding apparatus used in a molding method of the present invention.

FIG. 2 is an explanatory view illustrating a state in which an upper die is submerged in a molten metal.

FIG. 3 is an explanatory view illustrating a state in which an upper die is pulled up from a molten metal.

FIG. 4 is an explanatory view illustrating a state in which the molten metal attached to the upper mold is enclosed in a molding space.

FIG. 5 is an explanatory diagram illustrating a state in which a molded body is released.

FIG. 6 is a characteristic diagram showing the relationship between the total amplitude of ultrasonic vibration applied to the upper mold when pulled up from the liquid and the amount of adhesion.

FIG. 7 is an explanatory diagram showing a flow of a liquid when the ultrasonically excited solid is submerged in the liquid.

FIG. 8 is a characteristic diagram showing the relationship between the temperature of molten metal and the adhesion amount.

FIG. 9 is a characteristic diagram showing the relationship between the total amplitude of ultrasonic power applied to the mold and the molten metal deposition amount.

FIG. 10 is a chart exemplifying the transition of the temperature of each part when the mold is submerged in the molten metal.

[Explanation of symbols]

10: Ultrasonic shaker 12: oscillator 14: Horn 16: Ultrasonic oscillator 20: Upper mold 30: Lower mold 42: molten metal

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiki Tsunekawa             1-12 Kuma 1-Tenpaku-ku, Nagoya-shi, Aichi               Toyota Institute of Technology

Claims (5)

[Claims] 1. A step of attaching a liquid to a solid by immersing the ultrasonically excited solid in the liquid and then pulling it up, and confining the attached liquid in a molding space formed between the solid and the mold. And a step of solidifying the liquid by means of an ultrasonic forming method, wherein the power of ultrasonic waves applied to the solid is varied in accordance with the progress of the step. 2. The ultrasonic forming method according to claim 1, wherein the power of the ultrasonic wave applied to the solid is reduced and then the solid is pulled out of the liquid. 3. The ultrasonic forming method according to claim 1, wherein the power of ultrasonic waves applied in the step of solidifying the liquid is varied in accordance with the progress of solidification. 4. The ultrasonic forming method according to claim 3, wherein the power of ultrasonic waves applied in the initial stage of solidification is made higher than in the latter stage of solidification. 5. The ultrasonic molding method according to claim 1, wherein the solid is a mold, and the mold is ultrasonically excited to release the molded body.