KR100717451B1 - Manufacturing apparatus for damping pipe and a die for the same - Google Patents

Abstract

The apparatus for manufacturing a vibration suppression pipe according to the present invention includes a crucible in which a melt is accommodated therein; A heating body for heating the crucible; And a die immersed in the melt and provided in a multi-layered structure in a horizontal direction.

According to the present invention, the shape of the die mounted on the solid solution boundary portion to which the melt is solidified is improved, so that the physical characteristics of the vibration suppression pipe manufactured are improved. In addition, the vibration suppression pipe can be manufactured in a state where there is no temperature gradient, so that the vibration suppression pipe of the shape memory alloy having a stable structure can be manufactured.

Vibration Damping Pipe, Shape Memory Alloy, Die

Description

Manufacturing apparatus for damping pipe and a die for the same

1 is a cross-sectional view illustrating the structure of a puller to which the present invention is applied.

Figure 2 is a perspective view of the damping pipe manufacturing die according to the present invention.

3 is a cross-sectional view of II ′ of FIG. 2.

<Explanation of symbols for the main parts of the drawings>

31: first platform 32: second platform 33: connection

34: Post 35: Round Slit 36: Screw

Korean Patent Application No. 10-2002-0083873

Korean Patent Publication No. 10-2000-0075400

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping pipe, and more particularly, to a manufacturing apparatus and a manufacturing method of a vibration damping pipe which can be manufactured using a shape memory alloy to maximize the damping force. In particular, the present invention relates to a manufacturing die for the production of a vibration suppression pipe made of a shape memory alloy.

General household appliances such as air conditioners and refrigerators have built-in devices that generate vibration, such as compressors. Since such home appliances are mainly used indoors, vibrations generated by the home appliances cause discomfort to the user.

Many attempts have been made to solve this problem. Among these attempts, a shape memory alloy has been proposed to be used as a pipe connected to the compressor so that a damping effect occurs in the pipe connected to the compressor. . As an example of using the shape memory alloy pipe, the present invention has already been proposed in Korean Patent Application No. 10-2002-0083873. The shape memory alloy obtains a shape memory effect by using the phase change property of martensite and austenite.

The shape memory alloy is used as a reinforcement pipe because the shape memory alloy has elasticity and plasticity at the same time, unlike general metals, so that vibration is absorbed by using the property of acting as a plastic body at a constant temperature against external vibration. This is because it can be used to return to the original shape in another constant temperature range.

However, since the shape memory alloy has a lot of physical properties against vibration depending on the manufacturing process and the manufacturing environment, a specific manufacturing method has to be proposed in order to maximize the damping characteristics of the dust collecting pipe.

On the other hand, the damping force of a general metal or alloy is generally evaluated by the following equation (1).

ψ = 2πQ ^-1 100%

Where ψ represents a damping power and Q ⁻¹ represents internal friction of the shape memory alloy. In this case, when the damping force (ψ) is less than 1%, it is called a low damping material, when 1% <ψ <10%, it is called an intermediate damping material, and when 10% <ψ <100%, it is called a high damping material. have.

As apparent from Equation 1, the shape memory alloy exhibits a high damping force as the internal friction increases. In addition, as the internal friction is known by a number of experiments and several documents, when the martensite structure is present, the maximum internal friction occurs in the case of monocrystal, and the internal friction in the case of polycrystal Since it is small, it is preferable to use the shape memory alloy of a single crystal structure in order to increase the internal friction of the shape memory alloy.

On the other hand, in order to improve the mass productivity of the vibration suppression pipe manufactured using the shape memory alloy, a specific manufacturing method has to be proposed. In particular, in order to improve the physical characteristics of the vibration suppression pipe during the mass production process, the melt is in a molten state. It is important to make the temperature gradient of the vibration suppression pipe uniform in the vertical, horizontal and radial phases when solidified and crystallized at.

The present invention is proposed under the background described above, and proposes an apparatus for manufacturing a vibration suppression pipe and a manufacturing die for the vibration suppression pipe to improve the physical characteristics of the vibration suppression pipe by improving the shape of the die mounted to an adjacent portion where the melt is solidified. It aims to do it.

In addition, an object of the present invention is to propose an apparatus for manufacturing a vibration suppression pipe and a manufacturing die for the vibration suppression pipe in which the appearance of the vibration suppression pipe is improved and the crystallization process in which the melt is solidified can be performed stably.

The apparatus for manufacturing a vibration suppression pipe according to the present invention for achieving the above object is a crucible in which a melt is accommodated therein; A heating body for heating the crucible; And a die immersed in the melt and provided in a multi-layered structure in a horizontal direction.

According to another aspect, a manufacturing die of the vibration suppression pipe according to the present invention includes a first platform disposed below; A second platform placed on an upper side and having a plurality of holes formed therein; A connection unit vertically connecting the first platform and the second platform; And a post coupled to the first platform and partially extending into the hole.

The vibration suppression pipe can be manufactured in a stable state by the proposed apparatus for manufacturing the vibration suppression pipe and the manufacturing die of the vibration suppression pipe, and the physical properties of the vibration suppression pipe can be improved.

First, a method of manufacturing a single-crystal shape memory alloy is introduced. In general, a method of manufacturing a shape memory alloy includes a Brigman's method, a chokhralsky's method, and a wannril's method. And stepanov's method have been introduced. These methods are methods in which a single crystal alloy is produced from a molten alloy, and the present invention exemplarily illustrates a process in which an alloy of copper, aluminum, and nickel is manufactured into a single crystal alloy by the Czochralski method.

The Czochralski method has been widely known as a method of growing a single crystal silicon substrate, and is already well known through the related international patent classification C30B15 / 00. Specifically, Korean Patent Application Publication No. 10-2000-75400 may be exemplified as a specific application example of the Czochralski method.

1 is a view for explaining the structure of a Czochralski puller.

Referring to FIG. 1, the Czochralski pooler of the present invention includes a furnace 1 in which a high temperature environment is created inside, and a crucible 2 in which a melt 8 is accommodated in the furnace 1. ), A heating body 7 provided at an adjacent position of the crucible 2, and a die 3 which is placed on the upper side of the crucible 2 so as to produce a single crystal of a specific shape.

In addition, a shape memory alloy 9 of a shape corresponding to the opening of the die 3 is shown, wherein the shape memory alloy 9 is continuously pulled upward at a constant speed. Specifically, the melt 8 in contact with the shape memory alloy 9 is pulled upward during the operation in which the shape memory alloy 9 is pulled up in contact with the shape memory alloy 9. The melt 8 is then made of a single crystal shape memory alloy 9 by a crystallization process that is cooled and solidified after being pulled up.

Of course, when the shape memory alloy 9 is first produced, a predetermined inoculum is immersed to a certain depth on the surface of the melt 8, and the shape memory alloy 9 is continuously raised while the inoculum is raised. This is grown.

As a concept in which the inoculum and the shape memory alloy 9 are included, a predetermined column immersed in the melt 8 causes the melt 8 to be cooled and solidified to produce a single crystal. Collectively referred to as a refrigerator. Adjacent positions of the coolers may be equipped with any type of cooling system that allows the temperature to be lower than ambient.

In addition, a power supply 4 is disposed outside the furnace 1, and the first electrode 5 connected to the power supply 4 contacts the shape memory alloy 9 and the second electrode 6. The silver is brought into contact with the melt 8, whereby the shape memory alloy 9 and the melt 8 are supplied with a current having a predetermined frequency which is energized in a predetermined direction. The current can effectively stabilize the level and width of the interface of the melt 8 and the cooler, and allow the grown crystals to have a particular crystallographic orientation.

Since the single crystal shape memory alloy manufactured through the above-described method improves single crystallinity, internal friction is maximized and the damping force can be maximized.

In particular, the present invention proposes a die structure in which the physical properties of the vibration suppression pipe are improved, the crystallization process is performed stably, and the temperature gradient during the crystallization process is uniformly formed vertically, horizontally, and radially so that the crystallization process is stably performed. It is characterized by the thing. Hereinafter, the die structure of the vibration suppression pipe will be described in detail.

2 is a perspective view of a damping pipe manufacturing die according to the present invention.

2, the manufacturing die 3 of the vibration suppression pipe according to the present invention includes a platform in the form of a die, and a post 34 fixed to the platform.

In detail, the platform includes a first platform 34 provided in the horizontal direction at the lower side, a second platform 32 provided in the horizontal direction at the upper side, the first platform 34 and the second platform 32. It includes a connecting portion 33 to connect in the vertical direction at the center of the approximately. In addition, the platform 31 and the post 34 are made of graphite so that they do not melt and resist heat even at a high melting temperature inside the crucible.

In addition, the second platform 32 is provided with a plurality of circular holes, in which the post 34 is inserted. Therefore, a circular slit 35 is formed in the interval between the outer circumferential surface of the post 34 and the inner circumferential surface of the circular hole.

A hollow hollow vibration damping pipe 9 is manufactured while passing through the circular slit 35 while the melt 8 is raised and solidified. In addition, since a plurality of circular slits 35 are provided in a single second platform 32, there are advantages in that a plurality of vibration suppression pipes can be manufactured during one pulling process.

3 is a cross-sectional view of the II ′ of FIG. 2, referring to FIG. 3, it will be clearly understood that the circular slit 35 is provided. In addition, the post 34 is fixed to the platform by a screw 36 inserted below the first platform 31. The screw 36 is also preferably made of graphite.

On the other hand, when the die 3 is immersed in the melt 8, a load portion such as a heat-resisting material or nickel having a high specific gravity is applied to the die 3 so that its own weight to be immersed to a predetermined depth or more is applied to the die 3. 3) can be further combined. In addition, in order for the immersion portions of the die 3 including the first platform 31 immersed in the melt 8 to resist heat, aluminum oxide (Al ₂ O ₃ ) is formed on the outer surface of the die _3. ) Is preferably further formed as a protective layer.

Referring to the advantages that can be obtained by the die of the damping pipe according to the present invention described above are as follows.

First, since a die can be manufactured simply by a process of coupling a post to a two-layered platform provided as a first platform and a second platform as a whole, the manufacturing cost of the die can be saved.

In addition, since the circular slit 35 manufactured in the vibration suppression pipe can be manufactured in an accurate and clean shape, there is an advantage that the appearance of the vibration suppression pipe is neat.

Further, crystallization can be performed stably because the thermal gradient can be uniformly distributed horizontally, vertically, and radially in the vicinity of the circular slit 35 where crystallization takes place.

In addition, since a plurality of circular slits 35 are formed in a single die, a plurality of vibration suppression pipes can be manufactured in one pulling process.

In addition, since the depth of the circular slit 35 can be adjusted by adjusting the size and shape of the platform and the post, there is an advantage that the control of the position where the crystallization occurs is convenient.

In addition, since the temperature gradient can be obtained uniformly and accurately at the interface of high melting, there is an advantage that the single crystal structure of the final vibration damping pipe can be perfectly provided.

In addition, the outer surface of the die 3 contacts the inner surface of the crucible 2 so that the position of the die 3 is guided, so that the horizontal state of the die 3 can be improved to obtain a uniform temperature gradient, This has the advantage that the crystallization process can be performed stably and uniformly.

On the other hand, the manufacturing die of the vibration damping pipe described above may be applied to the Czochralski puller, or may be easily modified and applied to other types of shape memory alloy manufacturing apparatus.

The vibration suppression pipe of the single crystal shape memory alloy manufactured by the above process is further subjected to a heat treatment process of the shape memory alloy in order to widen the martensite transformation temperature representing the maximum damping force, which will be described in detail below. do.

First, a floating-zone method is performed to change the single crystal shape memory alloy by refining the polycrystalline shape memory alloy which may be included in the single crystal shape memory alloy. The floating zone method may be performed until the desired crystal structure and shape of the vibration suppression pipe is provided. If the single crystallinity of the shape memory alloy is desired, the floating zone method may not be performed.

Thereafter, a tempering process is performed for 0.1 to 280 seconds at a temperature of 1.2 to 6.5 Af.

Then, the first alternating-sign plastic deformation is performed at the martensitic transformation start temperature (Ms). Specifically, the first alternating-sign plastic deformation is performed in the range of 0.001 to 20% of the deformation of the original form. 1 Alternate plastic deformation is performed. After heating to a temperature of 1.0 to 1.2 Af, the temperature is maintained for 15 to 30 seconds.

Thereafter, the second alternating plastic deformation is performed at the martensite transformation end temperature Mf, and the second alternating plastic deformation is gradually increased in the range of 0.01 to 50%. The shape is maintained for 0.1 to 280 seconds at a temperature of 1.2 to 6.5 Af.

The heat treatment method as described above is performed by the change of phase of the single crystal shape memory alloy. In other words, a plastic phase is applied in the martensite transformation temperature range (Ms-Mf) and maintained for a certain time at a temperature above the martensite reverse transformation end temperature (Af). ) To increase the temperature range in which the maximum damping force is generated in the vibration suppression pipe.

This phase change process, in which the initial β1 'phase changes to the martensite γ1' phase, results in a change in the microscopic shape of the deformed portion of the damping pipe, and the reverse martensite transformation end temperature (Af). The external stress applied above) not only increases the reverse martensite transformation temperature (As-Af) but also forms a new martensite structure.

Hereinafter, the change of the phase of the shape memory alloy will be described in detail.

In detail, when the initial β1-phase included in the Cu-Al-Ni single crystal shaped enterprise alloy is cooled, it becomes γ1'-phase, and β1'-phase is formed under the influence of external stress.

On the contrary, when the external stress is removed, an inverse transformation occurs in which the β1'-phase becomes a β1-phase, and if the β1'-phase obtained under the influence of mechanical stress is cooled to a low temperature, the phase is converted to the γ1'-phase do.

In conclusion, the load on the single crystal is made into the structure of β1 'single crystal. Furthermore, the additional load will change the shape of β1'-phase into α1'-phase of the face centered cubic system.

As described above, the heat treatment process of the shape memory alloy according to the present invention is a process of annealing on the β-phase of the shape memory alloy, the process of maintaining the deformation state at a temperature higher than the martensite reverse transformation temperature (Af), tempering Process, the directional crystallization process of the alloy.

It presents a specific experimental example of the heat treatment method of the vibration damping pipe as described above.

Experimental Example

1. Make a molten alloy based on copper and containing 13.4% by weight of aluminum and 3.2% of nickel. The alloy has a martensite transformation start temperature (Ms) of 40 ° C. and a martensite transformation end temperature (Mf). ) Is 10 ° C, the martensite reverse transformation start temperature (As) is 45 ° C, and the martensite reverse transformation end temperature (Af) is 75 ° C.

2. The vibration suppression pipe of single crystal is manufactured by the Choklasky method at 1075 degreeC which is the melting temperature (Tm) of the said alloy.

3. Thereafter, the obtained vibration damping pipe is annealed at a stable β-phase temperature range in a 10% sodium chloride solution at 910 ° C.

4. The damping pipe is heated to 6.2Af and maintained for 10 seconds.

5. After cooling to the martensitic transformation start temperature (Ms), a first alternating plastic deformation of the damping pipe is carried out starting from 0.001% to 10.2% strain for the initial shape of the damping pipe.

6. Heat to 1.0 Af, and hold for 15 seconds.

7. At the martensite transformation start temperature Mf, the second alternating plastic deformation is performed. In this case, the strain rate is gradually increased by 0.2% and is deformed up to 5.0%.

8. After the second alternating plastic deformation is performed, it is heated to a temperature of 1.2 Af and maintained for 2.0 seconds.

After the heat treatment is performed by the above process, it can be seen that the temperature range in which the maximum damping force is generated is increased 3 to 7 times compared to the vibration suppression pipe before the heat treatment is performed. This is because the intermediate martensite phases are formed in the shape memory alloy by the heat treatment process.

Differences in the damping force between the vibration suppression pipes subjected to the heat treatment according to the present invention described above and the general copper pipe will be described with reference to Table 1 below.

Dongguan Vibration damping pipe of the present invention Natural frequency Damping ratio Natural frequency Damping ratio Primary 168 0.011 90 0.081 Secondary 469 0.006 244 0.057 3rd 914 0.005 483 0.037 4th 1495 0.006 786 0.038 5th 2208 0.005 1160 0.027 Attenuation coefficient α 23.39 98.09 Attenuation coefficient β 7.70E-07 8.60E-06

Table 1 shows the result of measuring one end of the tube having a length of 40 cm and the other end of the vibration measuring end.

Referring to Table 1, it can be seen that the vibration suppression pipe of the present invention is about 5 times superior to the conventional copper pipe.

According to the present invention, there is an advantage that the physical characteristics of the vibration suppression pipe manufactured by improving the shape of the die mounted on the solid solution boundary where the melt is solidified is improved. In addition, the vibration suppression pipe can be manufactured in a state where there is no temperature gradient, so that the vibration suppression pipe of the shape memory alloy having a stable structure can be manufactured.

In addition, there is an advantage that the appearance of the vibration damping pipe can be improved and the crystallization process can be performed stably.

Claims (12)

A crucible in which a melt is received; A heating body for heating the crucible; And At least one layer is immersed in the melt and includes a die provided in a multi-layered structure in a horizontal direction, Apparatus for producing a vibration suppression pipe is cooled in the process of the melt is pulled to produce a single crystal damping pipe. The method of claim 1, The die is a manufacturing apparatus of the vibration suppression pipe is formed a plurality of holes in which the melt is drawn. The method of claim 1, The die is a two-layer structure of the vibration suppression pipe manufacturing apparatus. The method of claim 1, The outer surface of the die is in contact with the inner surface of the crucible manufacturing apparatus of the damping pipe. A first platform underlying; A second platform placed on the upper side and in which holes are formed; A connection unit vertically connecting the first platform and the second platform; And A post coupled to the first platform and partially extending into the hole, The manufacturing die of the vibration suppression pipe that the melt is pulled through the gap between the post and the hole. The method of claim 5, The connecting portion is a manufacturing die of the vibration suppression pipe is placed in the center. The method of claim 5, The hole is a manufacturing die of the vibration suppression pipe is formed a plurality. The method of claim 5, The platform or the post is a manufacturing die of the vibration damping pipe made of graphite. The method of claim 5, The post is a manufacturing die of the vibration damping pipe is coupled to the screw of graphite material on the first platform. The method of claim 5, The platform is a manufacturing die of the vibration suppression pipe of a circular shape. The method of claim 5, And a heat-resistant protective layer is formed on an outer surface of at least a portion of the manufacturing die. The method of claim 5, At least a portion of the manufacturing die manufacturing die of the vibration suppression pipe is further provided with a load portion for increasing the load.

Images