JP2016153130A - Ultrasonic casting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic casting device capable of obtaining high airtightness while suppressing attenuation of vibration in an axial direction of a vibration transmission body.SOLUTION: An ultrasonic casting device 1 comprises: a vibration generator 13 which generates ultrasonic vibration; a housing 3 including a compression chamber 5 which holds molten metal 2 and in which a compression gas for injection to a mold 11 is supplied to an upper space 51 of the molten metal; a vibration transmission body 6 which extends from the vibration generator 13 to the molten metal 2; a flange which is provided in the vibration transmission body 6; an annular seal member which is arranged between the housing 3 and the flange and projects to the periphery of the flange; and a holder which is fixed to the housing 3 and includes a peripheral wall forming a gap with the outer peripheral surface of the flange and pressing the outer peripheral part of the seal member against the housing 3, and a ring part protruding inward from the peripheral wall so as to cover the gap between the peripheral wall and the outer peripheral surface of the flange and is brought into contact with the flange over the whole periphery to press the flange against the housing 3 via the seal member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ultrasonic casting apparatus that applies ultrasonic vibration to a molten metal before being poured into a mold.

  Conventionally, it is known that crystal grains generated during casting can be refined by applying ultrasonic vibration to a molten metal before being poured into a mold (see, for example, Non-Patent Document 1). In recent years, development of an ultrasonic casting apparatus that achieves this has been underway.

Park Silence, 1 outside, “Ultrasonic Casting”, Production Research, Institute of Industrial Science, University of Tokyo, August 1, 1965, Vol. 17, No. 8, p. 195-199,216

  For example, in a low pressure casting method using pressurized gas (for example, air) for pouring molten metal into a mold, a casting apparatus including a housing to which the mold is attached is used. The housing is formed with a pressurizing chamber that holds the molten metal and is supplied with a pressurized gas for injection into the mold in a space above the molten metal. In such a casting apparatus, for example, if the following configuration is adopted, an ultrasonic casting apparatus can be obtained.

  First, it is necessary to provide a vibration generator that generates ultrasonic vibrations. The vibration generator is preferably arranged outside the housing in order to avoid the influence of heat. For this reason, a vibration transmission body is provided that extends from the vibration generator through the upper space of the housing and the molten metal to the molten metal. If it does so, it is necessary to ensure airtightness between a vibration transmission body and a housing.

  Generally, a vibration transmission body used for transmission of ultrasonic vibration may be provided with a flange at a position that becomes a node of an expansion / contraction waveform due to ultrasonic vibration. Therefore, it is conceivable to seal between the housing and the vibration transmitting body using this flange. For example, a seal member is interposed between the flange and the housing, and the flange is fixed to the housing with a bolt or the like, whereby the seal member is pressed against the housing by the flange.

  However, in the low pressure casting method, it is necessary to precisely control the pressure in the pressurizing chamber in order to prevent casting defects such as shrinkage cavities and poor hot water circulation when pouring molten metal into the mold. For that purpose, very high airtightness is required between the vibration transmitting body and the housing.

  In order to obtain high airtightness in the configuration in which the seal member is pressed against the housing by the flange as described above, a large pressing area of the seal member to the housing may be ensured. For that purpose, the flange must be enlarged.

  By the way, in a flange, the outer peripheral surface of a flange vibrates to the radial direction of a vibration transmission body by the partial expansion-contraction by the ultrasonic vibration of a vibration transmission body. The amplitude of the outer peripheral surface of the flange increases as the flange increases in size. In other words, as described above, when the flange is enlarged in order to ensure a large pressing area of the seal member to the housing, the airtightness increases, but the large amplitude of the outer peripheral surface of the flange causes the flange to be fixed to the housing. As a result, the axial vibration originally required for the vibration transmitting body is attenuated. On the other hand, if the flange is downsized, the attenuation of vibration in the axial direction of the vibration transmitting body can be suppressed, but the airtightness is lowered.

  Then, an object of this invention is to provide the ultrasonic casting apparatus which can obtain high airtightness, suppressing the attenuation | damping of the vibration of the axial direction of a vibration transmission body.

  In order to solve the above problems, an ultrasonic casting apparatus of the present invention includes a vibration generator that generates ultrasonic vibrations, a molten metal that is held, and a pressurized gas that is injected into a mold is supplied to an upper space of the molten metal. A housing including a pressurized chamber, a vibration transmission body extending from the vibration generator through the housing and the upper space of the molten metal to the molten metal, and a node of an expansion and contraction waveform due to ultrasonic vibration in the vibration transmission body; A flange facing the housing outside the housing, an annular seal member projecting around the flange disposed between the housing and the flange, and fixed to the housing. A peripheral wall that forms a gap with the outer peripheral surface of the flange and presses the outer peripheral edge of the seal member against the housing; and A ring portion that protrudes inward from the peripheral wall so as to cover a gap between the wall and the outer peripheral surface of the flange, contacts the flange over the entire circumference, and presses the flange against the housing via the seal member And a holder including:

  According to the above configuration, since the seal member is pressed against the housing by the flange and the peripheral wall of the holder, a large pressing area of the seal member to the housing can be secured. For this reason, it is possible to reduce the size of the flange to suppress the vibration attenuation in the axial direction of the vibration transmitting body, and even in this case, high airtightness can be obtained between the seal member and the housing. In addition, since the vibration between the outer peripheral surface of the flange in the radial direction of the vibration transmission body is allowed by the gap between the peripheral wall of the holder and the outer peripheral surface of the flange, it is possible to more effectively attenuate the vibration in the axial direction of the vibration transmission body. Can be suppressed. On the other hand, when the flange is downsized, the contact area between the flange and the seal member decreases. However, the reduction in the sealing performance due to the decrease in the contact area can be covered by the contact area between the ring portion of the holder and the flange. Therefore, high airtightness can be obtained on both sides of the seal member.

  The ultrasonic casting apparatus may further include an annular sealing material interposed between the ring portion of the holder and the flange. According to this configuration, the relative relative movement of the seal member interposed between the ring portion and the flange of the holder can be performed smoothly by elastic deformation thereof. Therefore, attenuation of vibration in the axial direction of the vibration transmitting body can be further suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, high airtightness can be acquired, suppressing attenuation | damping of the vibration of the axial direction of a vibration transmission body.

It is a schematic block diagram of the ultrasonic casting apparatus which concerns on one Embodiment of this invention. It is an enlarged view of the part which a vibration transmission body penetrates a housing. It is a figure which shows the attachment structure of a modification. It is a figure which shows the attachment structure of another modification. It is a schematic block diagram of the ultrasonic casting apparatus which concerns on another embodiment.

  FIG. 1 shows an ultrasonic casting apparatus 1 according to an embodiment of the present invention. The ultrasonic casting apparatus 1 includes a housing 3 to which a mold 11 is attached, a vibration generator 13 that generates ultrasonic vibrations, and a vibration transmission body 6 that is joined to the vibration generator 13.

  The housing 3 is a furnace body having a heat insulating structure capable of maintaining a high temperature. In the housing 3, a pressurizing chamber 5 that communicates with the inside of the mold 11 via an injection path 32 and a holding chamber 4 that communicates with the pressurizing chamber 5 via a supply path 31 are formed. The holding chamber 4 and the pressurizing chamber 5 hold the molten metal 2. In addition, the housing 3 is provided with a gate device 12 that opens and closes the supply path 31, and on / off of the supply of the molten metal 2 from the holding chamber 4 to the pressurizing chamber 5 is switched by opening and closing the supply path 31 by the gate device 12. It is done.

  In the present embodiment, the casting inlet of the mold 11 opens downward, and the molten metal 2 is poured upward into the mold 11. However, the injection direction of the molten metal 2 into the mold 11 is not limited to the upward direction, and may be, for example, a lateral direction or a downward direction. The mold 11 is not particularly limited, and may be, for example, a sand mold or a mold.

  Although the metal which comprises the molten metal 2 is not specifically limited, For example, they are an aluminum alloy, a magnesium alloy, a copper alloy, etc.

  A pressurized gas for injection into the mold 11 is supplied to the upper space 51 of the molten metal 2 in the pressurizing chamber 5. The pressurized gas may be air or another gas (for example, an inert gas). In the present embodiment, the housing 3 includes a lid 52 that constitutes the ceiling of the pressurizing chamber 5, and a pressurizing path 53 is provided in the lid 52. Then, the pressurized gas is supplied to the upper space 51 of the molten metal 2 through the pressurizing passage 53. Note that the pressurizing path 53 is not necessarily provided in the lid body 52, and may be provided in a body portion constituting the wall surface of the pressurizing chamber 5 in the housing 3.

  The above-described vibration transmission body 6 extends from the vibration generator 13 through the lid 52 and the upper space 51 of the molten metal 2 to the molten metal 2. However, the vibration transmitting body 6 does not necessarily have to pass through the lid body 52, and may pass through a body portion that constitutes the wall surface of the pressurizing chamber 5 in the housing 3.

  As shown in FIG. 2, the vibration transmission body 6 is provided with a flange 65. The flange 65 is disposed at a position that becomes a node of an expansion / contraction waveform due to ultrasonic vibration in the vibration transmitting body 6. Further, the flange 65 is opposed to the lid body 52 outside the housing 3.

  In the present embodiment, the vibration transmission body 6 includes a booster 61 connected to the vibration generator 13 and a horn 64 connected to the booster 61. The above-described flange 65 is formed integrally with the booster 61.

  The vibration generator 13 has a built-in vibrator and converts a voltage change into vibration. The booster 61 and the flange 65 are made of, for example, a titanium alloy having low thermal conductivity. The booster 61 includes a large diameter portion 62 located on the vibration generator 13 side from the flange 65 and a small diameter portion 63 located on the horn 64 side from the flange 65. However, the booster 61 may have a constant diameter over the entire length. The horn 64 is made of a material (for example, ceramics) that does not dissolve when immersed in the molten metal 2.

  The shape of the flange 65 may be a circular shape, or may be a polygonal shape of a quadrangle or more. Between the flange 65 and the lid body 52, an annular seal member 8 having a central hole inserted through the vibration transmitting body 6 is disposed. An annular holder 7 is disposed around the flange 65. The annular shape of the seal member 8 and the holder 7 is a shape (circular shape or polygonal shape) that matches the shape of the flange 65.

  More specifically, the seal member 8 has a larger contour than the contour of the flange 65 and projects around the flange 65. The seal member 8 is not particularly limited, but is a woven fabric gasket, for example.

  The holder 7 is made of, for example, steel and is fixed to the lid body 52 with bolts 9. However, as a means for fixing the holder 7 to the lid 52, various means (for example, magnetic force) other than the bolt 9 can be employed. The holder 7 includes a peripheral wall 71 that surrounds the flange 65, and a ring portion 72 that protrudes inward from the upper end of the peripheral wall 71.

  The inner surface of the peripheral wall 71 is separated from the outer peripheral surface of the flange 65, and a gap is formed between the peripheral wall 71 and the outer peripheral surface of the flange 65. For example, when the flange 65 and the holder 7 are circular, the peripheral wall 71 has an inner diameter larger than the outer diameter of the flange 65. The peripheral wall 71 presses the outer peripheral edge of the seal member 8 against the lid 52 by fixing the holder 7 to the lid 52 with the bolt 9.

  The ring portion 72 protrudes inward from the upper end portion of the peripheral wall 71 so as to cover the gap between the peripheral wall 71 and the outer peripheral surface of the flange 65. The ring portion 72 contacts the flange 65 over the entire circumference. In other words, the holder 7 is configured to seal a gap between the peripheral wall 71 and the outer peripheral surface of the flange 65. In the present embodiment, the ring portion 72 has a certain thickness and contacts the outer peripheral edge portion of the flange 65. The ring portion 72 presses the outer peripheral edge portion of the flange 65 against the lid body 52 through the seal member 8 by fixing the holder 7 to the lid body 52 with the bolt 9.

  As described above, in the ultrasonic casting device 1 of the present embodiment, the seal member 8 is pressed against the lid body 52 by the flange 65 and the peripheral wall 71 of the holder 7, so that the pressing area of the seal member 8 against the lid body 52 is A can be secured large. For this reason, the flange 65 can be downsized to suppress the attenuation of the vibration in the axial direction of the vibration transmitting body 6, and even in this case, high airtightness can be obtained between the seal member 8 and the lid body 52. it can. Further, since the vibration between the outer peripheral surface of the flange 65 in the radial direction of the vibration transmitting body 6 is allowed by the gap between the peripheral wall 71 of the holder 7 and the outer peripheral surface of the flange 65 (the actual vibration of the outer peripheral surface of the flange 65 is Further, the vibration attenuation in the axial direction of the vibration transmitting body 6 can be more effectively suppressed. On the other hand, when the size of the flange 65 is reduced, the contact area B between the flange 65 and the seal member 8 is reduced. The reduction in the sealing performance due to the decrease in the contact area B is caused by the contact area between the ring portion 72 of the holder 7 and the flange 65. Can be covered with C. Therefore, high airtightness can be obtained on both sides of the seal member 8.

<Modification>
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  For example, the vibration transmission body 6 does not necessarily need to be composed of the booster 61 and the horn 64, and may be a rod-shaped body having a constant diameter over the entire length.

  Moreover, in the said embodiment, although the flange 65 and the ring part 72 of the holder 7 were metal touches, as shown in FIG. 3, between the ring part 72 of the holder 7 and the outer peripheral edge part of the flange 65, An annular sealing material 85 may be interposed. According to this configuration, smooth relative movement between the ring portion 72 of the holder 7 and the flange 65 can be achieved by elastic deformation of the sealing material 85. Therefore, attenuation of vibration in the axial direction of the vibration transmitting body 6 can be further suppressed.

  Further, the ring portion 72 of the holder 7 does not necessarily have a constant thickness, and the inner peripheral edge portion of the ring portion 72 may protrude toward the flange 65 as shown in FIG. That is, the ring part 72 may contact the intermediate part or the inner peripheral part instead of the outer peripheral part of the flange 65.

  Further, as shown in FIG. 5, the casting mold 11 is attached to a lid body 52 that constitutes the ceiling of the pressurizing chamber 5, and an injection pipe 15 for pouring the molten metal 2 into the casting mold 11 in the pressurizing chamber 5. May be provided.

DESCRIPTION OF SYMBOLS 1 Ultrasonic casting apparatus 11 Mold 13 Vibration generator 2 Molten metal 3 Housing 5 Pressurizing chamber 51 Upper space of molten metal 6 Vibration transmission body 65 Flange 7 Holder 71 Peripheral wall 72 Ring part 8, 85 Sealing material

Claims (2)

A vibration generator that generates ultrasonic vibrations;
A housing that includes a pressurizing chamber that holds the molten metal and is supplied with a pressurized gas for injection into the mold in an upper space of the molten metal;
A vibration transmission body extending from the vibration generator to the molten metal through the housing and the upper space of the molten metal;
A flange facing the housing outside the housing, provided at a position that becomes a node of an expansion / contraction waveform by ultrasonic vibration in the vibration transmitting body;
An annular sealing member disposed between the housing and the flange and extending around the flange;
A holder fixed to the housing, wherein a gap is formed between the outer peripheral surface of the flange and the outer peripheral edge of the seal member is pressed against the housing; and the peripheral wall and the outer peripheral surface of the flange A holder including a ring portion that protrudes inward from the peripheral wall so as to cover a gap therebetween, and that contacts the flange over the entire circumference and presses the flange against the housing via the seal member;
An ultrasonic casting apparatus comprising: The ultrasonic casting apparatus according to claim 1, further comprising an annular sealing material interposed between the ring portion of the holder and the flange.

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