JP3497341B2 - Semi-molten separation method for brazing sheet scrap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention is used for heat exchangers and the like.
Aluminum alloy brazing sheet scrub
For separating the brazing material from the core material
Method, especially taking advantage of the difference in melting point between the brazing material and the core material.
To a semi-molten state where only the brazing material is substantially melted.
To separate the molten brazing material from the solid core material
It is about the method. [0002] BACKGROUND OF THE INVENTION As is well known, a brazing sheet is
Low melting on one or both sides of core material to be structural material after brazing
It is clad with brazing filler metal as a skin material.
Has been widely used for brazing structures such as heat exchangers.
You. In recent years, heat exchange with radiators and the like of automobiles
For heat exchangers, aluminum alloys are used for weight reduction.
Aluminum alloys used for heat exchangers
Production of brazing sheets made of brass is also increasing
You. On the other hand, the brazing sheet is
It is a kind of clad material that is clad with
In the manufacturing process of such clad material, a large amount of scrap
Lapping material is generated. In other words, the crimping process between dissimilar alloys and
Of the front and rear ends in the hot rolling process
Material, or width in each step of hot rolling and cold rolling
Trimming material for defective parts on both sides
Manufacturing process such as off-gauge part cut off for dimension adjustment
The amount of scrap generated inside is extremely large, and in extreme cases
Means that the amount of scrap during the process is almost equal to the amount of product paid out
And the brazing sheet manufacturing method
The effective collection, processing and re-use of scrap material.
Its use is an important technical issue. [0004] Generally, aluminum alloy brazing members
7-12% of brazing material used as a skin material
Aluminum alloy containing a large amount of Si
Generally, Al-Mn alloys are used as the core material.
And the composition of the alloy components of the two are completely different. Blaze
The core material usually occupies 60 to 90% of the total weight of the
The brazing sheet
When re-melting the raw material as it is, the brazing material
However, only materials with an incomplete alloy composition
For the brazing sheet core material and brazing material.
It cannot be reused as it is, and is used for other low-grade materials
Or used as a partial compounding material
Not get. And this is the production of brazing sheets
Material costs for
You. [0005] Therefore, the scrap material of the brazing sheet
From scrap to brazing filler metal
Separating only the part, new brazing of the remaining core part
A new material is used for the core material of the sheet and the brazing material that has been separated and recovered.
Technology for reusing brazing material for lasing sheets,
That is, the direct lisa of the brazing sheet scrap
The development of cycle technology is urgently needed. [0006] By the way, brazing sheet scrap material
To separate the brazing filler metal from the core material
As for the method, in JP-A-4-218624,
A method that uses the difference in melting point between the skin material (brazing material) and the core material is proposed
Have been. In other words, in this method, the melting point of the brazing material is
Is generally 60 degrees C or more lower
Temperature that is above the liquidus of the brazing material and below the solidus of the core
Each time, only the brazing material on the surface is melted without melting the core material.
Melts and separates and recovers molten brazing material from core material
The present inventors have adopted such a method as semi-molten
This is called the separation method. [0007] SUMMARY OF THE INVENTION As described above,
In the proposed semi-solid separation method,
There was a problem. That is, in the brazing sheet,
The interface between the core material and the brazing material is firmly joined by metallurgy
Therefore, if external heating is applied,
Interdiffusion of alloy components is likely to occur on the surface, especially in the liquid and solid phases.
At the interface with, diffusion tends to occur significantly. Therefore external
The brazing filler metal using the difference in melting point
Satisfactory separation results were difficult to obtain even when separated
That is the fact. Specifically, the brazing material, which is a skin material, and the core material
Near the interface, from the molten brazing material to the core material
Diffusion increases the Si concentration of the core material, resulting in
Reuse of the core material after material separation was hindered, and brazing
It is difficult to sufficiently separate and recover the material. In addition, external
Simple heating from above requires sufficient melting of the brazing material.
Time is long, and accordingly, near the interface as described above
There is a problem that the problem due to the diffusion in the case occurs remarkably. [0010] The thickness of the brazing material, particularly the skin material on the surface
If the thickness is thin, the surface of the brazing
The effect of surface tension on separation is no longer negligible.
In some cases, mere heating can provide satisfactory separation results
The fact is that it is often lost. The present invention has been made in view of the above circumstances.
What about brazing sheet scrap?
Semi-melt separation method using the difference in melting point between filler material (skin material) and core material
In separating the brazing material from the core material by
Solve problems and remove only brazing material on the surface quickly and efficiently
Melt separation, separation and collection of core material and separation of brazing material
The core of a new brazing sheet as it is
To ensure that they can be reused as brazing and brazing materials
In addition, the basic purpose is to improve the processing efficiency,
Is it reliable even if the brazing material is thin, especially as a surface material?
To provide efficient and efficient separation of brazing material
It is intended to do so. [0012] Means for Solving the Problems The above-mentioned problems are solved.
As a result of repeated experiments and studies by the present inventors,
High frequency as heating means for brazing sheet scrap
Applying induction heating to properly determine the heating conditions
Therefore, only brazing material as a surface cladding material can be used quickly and efficiently.
Can be melted, and as such a surface skin material
After melting the brazing material, apply vibration or impact force under appropriate conditions.
Effectively removes the droplets generated on the surface
Separation to increase separation and recovery efficiency, and furthermore, melting
Add mechanical vibration or impact force for brazing material separation
The timing of the addition appropriately
In this way, the components of the brazing material droplets
Found that penetration into the wood could be minimized,
Of the invention. [0013] Specifically, the blaze according to the first aspect of the present invention
Semi-solid separation method of scraping sheet scraps, vertical axis
Around the crucible around the center of the crucible.
A high-frequency current through the heating coil
Aluminum alloy brazing sheet screen in crucible
Heat the wrap and braze the brazing sheet scrap
The brazing material is melted due to the difference in melting point between the
Semi-molten separation method that melts and separates only brazing material from core material
In addition, the brazing sheet scrap, its full weight
80% or more of the scrap is at an angle of 60 degrees or more from the horizontal plane
Into the crucible so that it is standing upright
In addition, the frequency f (Hz)
According to the thickness t (mm) of the wrap, t ≧ 40.4 (1 / f)^1/2 A high-frequency current that satisfies
The heating melts the brazing material on the surface of the brazing sheet.
And at the time of high-frequency induction heating,
The anode voltage of the oscillation tube that generates the high-frequency current for
And start the induction heating before starting the anode of the oscillation tube.
To said maximum after the current has increased and reached a maximum
The amount of decrease in anode current ΔI (mA) is
Scrap thickness t (mm) and loading scrap material
The following equation according to the total weight w (g) ΔI · t / w> 10^-3 And after 10 seconds of the anode current value
When the decrease of the acceleration becomes 0.025 A or less, the acceleration becomes 1
Melting by applying mechanical vibration or impact force of 0G or more
The brazing material is separated from the core material.
You. [0014] [0015] [0016] [0017] [0018] DETAILED DESCRIPTION OF THE INVENTION A brazing sheet according to the present invention.
An example of a situation where a semi-solid separation method for crap is being implemented
FIG. 1 schematically shows the configuration of the apparatus. In FIG. 1, a crucible 1 made of a heat-resistant material is used.
Is formed in a substantially cylindrical shape centered on the vertical axis,
Around the crucible 1 around a vertical axis
A spiral heating coil 2 is provided. Further
The portion corresponding to the lower bottom of the crucible 1 has a mesh structure or
Is provided with a transparent supporting member 3 having a lattice shape or a porous structure.
The upper surface is opened below the transparent support member 3.
A free receiving container 4 is provided. The crucible 1 itself
Is supported by supporting legs 5, and the supporting legs 5
Mechanically coupled to vibration or shock generator not shown
From the vibration or shock generator.
Mechanical vibration or impact force is applied to the crucible 1 via the legs 5
Is to be granted. If this mechanical vibration
Or the direction of the impact force should be vertical (vertical)
Is desirable. In the configuration shown in FIG.
The target brazing sheet scrap 6
Then, a high-frequency current is passed through the heating coil 2 to the scrap 6.
An eddy current is generated by electromagnetic induction. At this time,
The eddy current due to the magnetic induction causes the scrap 6
Generated on the surface layer, the surface layer self-heats, and
The brazing material melts. Some of the molten brazing material is a core material
The droplets remain on the surface, and a part is
Form a let. And a vibration generator (not shown)
Is the mechanical vibration or impact force applied from the shock generator
Of these molten brazes by acceleration and gravity due to
Flows down along the surface of the scrap, and
Through the transparent support member 3 at the bottom of the crucible 1
It is accommodated in the lower receiving container 4. Here, in carrying out the method of the present invention,
, The brazing sheet scrap is generally in the vertical direction
Store in an upright state in a crucible. More precisely, billing
8 of the total weight to be charged as specified in paragraph 1.
0% or more of the scrap is at an angle of 60 degrees or more from the horizontal plane
And housed in the crucible 1. Break as described above
Scrap generated during the jing sheet manufacturing process
Wood (crop, trimming, off-game)
Part) and its shape is plate-like
Because it is normal, handle as a plate material and as described above
Eighty percent or more stand at more than 60 degrees from horizontal
In a crucible in a vertical position
Can be accommodated. In this manner, the scrap is set up in a substantially vertical direction.
The reason for storing in the crucible in the pressed state is as follows. That is, the scrap is placed in a horizontal state and
When stored in the crucible 1 stacked below,
It is difficult for the brazing material to flow down and drip,
The molten brazing material stays on the surface of the scrap
Not only is it difficult to release, but the molten brazing material is
Alloy components of the molten brazing material, especially Si, to stay on the surface
Diffuses into the core material, producing so-called erosion
And the efficiency of separating and collecting the brazing material and the core material is reduced. This
Crucible with the scrap standing almost vertically
If it is stored in the pot, it will melt on the scrap surface.
The lumber easily flows down and drip easily.
Accordingly, the residence time of the molten brazing material on the core material surface is short.
Erosion as described above
Therefore, the efficiency of separating and collecting the brazing material and the core material is improved. In addition, around the vertical axis around the crucible,
The lines of magnetic force generated from the heating coil wound spirally
Within the crucible in a substantially vertical direction (parallel to the crucible axis
Direction).
Is generally parallel to the surface of the scrap placed in the vertical direction.
Penetrates into scrap and works near the surface layer of scrap
Eddy currents are generated, and high-frequency energy is described later.
Thus, it can be utilized for melting the brazing material efficiently. Here, originally all the scraps are vertical.
It is desirable to stand in the direction
All scraps of the law must be strictly vertical.
Therefore, according to the present invention, the screen to be charged is
80% or more of the total weight of the wrap is 60 degrees from the horizontal plane
We decided that we should stand at the above angle. From the horizontal plane
Scraps at an angle of 60 degrees or more are the total weight of loaded scrap
When the amount is less than 80%, the above-mentioned effect is effectively exhibited.
It becomes difficult. Further, in the present invention, the induction heating
The frequency f (Hz) of the high-frequency current for
The following equation (1) according to the plate thickness t (mm) t ≧ 40.4 (1 / f)^1/2      … (1) Must be determined to satisfy This is because
It depends. In heating the scrap, the core material is
Only the brazing material on the surface is melted quickly without melting,
To minimize the penetration of the brazing filler metal component into the core material
Is a self-heating device that uses electromagnetic induction to generate scrap
Heating rapidly, and at that time using high frequency,
Surface wax utilizing the skin effect peculiar to high frequency induction heating
It is appropriate to heat and melt the material preferentially. The object to be heated is heated by high-frequency induction heating.
The resulting eddy current flows mainly through the skin region of the object to be heated
This is known as the skin effect. Eddy current density
Is exponential as it goes from the skin to the inside of the object to be heated
But the current density in the epidermis is
The depth that can be assumed to flow through the cloth is that the current density is
Depth of 1 / e of degree (where e is the base of natural logarithm)
This depth is called the penetration depth of the eddy current, and the frequency and
Is expressed by the following equation (2). δ = 5.03 (ρ / μ_r・ F)^1/2      … (2) Here, δ is the penetration depth of the eddy current (cm), and ρ is the object to be heated.
Specific resistance (μΩcm) of aluminum alloy
At 650 ° C., ρ = 10.3 μΩcm can be set.
Also μ_rIs the relative magnetic permeability, which is almost
It can be placed with a bowl. F is the frequency (Hz)
You. On the other hand, in an object to be heated having a plate thickness t (mm),
The power consumption density per unit volume due to the eddy current loss is represented by the thickness t
Equation (3) determined by the depth and the penetration depth δ (mm) t / δ = 2.5 (3) It is known that the maximum occurs at the position. Therefore, in the object to be heated having a thickness t, a high circumference
In order to effectively realize wave induction heating, t / δ ≧ 2.
5 is satisfied, that is, the following equation (4) t ≧ 2.5δ (4) Needs to be satisfied. This equation (4) is 0.40t ≧ δ (4 ′) This equation (4 ′) can be rewritten as
The eddy current penetration depth δ is 40% or less of the plate thickness t.
Effective use of the skin effect when the brazing material on the surface
Can be preferentially melted. Focusing on the relationship between the frequency f and the thickness t,
And combining the above equations (2) and (4), and (2)
In the equation, the specific resistance ρ is 10.3 μΩcm, and the specific magnetic permeability μ_r
If you put 1 as t ≧ 2.5 × 5.03 (10.3 / f)^1/2= 40.4
(1 / f)^1/2 Thus, the above-mentioned equation (1) is obtained. That is, the sheet thickness t is set so as to satisfy the expression (1).
By determining the induction heating frequency f according to
By controlling the current penetration depth to 40% or less of the plate thickness t,
Effective heating and melting of the surface brazing material by the effect
You can. Here, the induced current at various frequencies f
Plate that can be expected to have the skin depth δ and skin effect based on it
Table 1 shows the result of calculating the range of the thickness t. [0034] [Table 1]From Table 1, for example, at a frequency of 200 kHz
When high-frequency current is used, plate thickness t is 0.9 mm or more
At 400 kHz, the thickness t is 0.65 mm or more.
By satisfying equation (4) or equation (1),
In that case, effective skin effect by high-frequency induction heating
Expecting for preferential and efficient melting of brazing material on the surface
It turns out that it gets. In addition, brazing sheet scrap
The brazing material of the scrap is charged by the high frequency induction heating
When melting the various types of
Scrap plates of different thicknesses may be mixed.
The thickness t of all loaded scrap plates
It is desirable that the frequency, the frequency f, and the function satisfy the above-described equation (1).
However, in practice, it is less than 2/3 of the total weight of the loaded scrap.
If the top is a plate thickness that satisfies the formula (1), some efficiency
The brazing material can be melted. In addition, a large number of scrap plates are mounted in the crucible.
Contact between the scrap plates when they are inserted
However, the surface of each scrap plate has an oxide film with high electrical resistance
Is usually thin, so the oxide film
It functions as an insulating film at the touching part,
The above-mentioned skin effect will be produced for each plate. Next, the melting of the brazing material specified in the present invention
Mechanical vibration or impingement to separate the subsequent molten wax droplets
The additional condition of the impact will be described. The brazing sheet scrap is almost vertically
High frequency induction heating in a crucible while standing in the direction,
As mentioned above, the brazing material on the scrap surface is preferentially melted.
Flow down along the surface of the scrap
It collects at the lower end of the plate to form fillet-shaped droplets. this
Fillet-shaped formed at the lower end of such a scrap plate
To separate droplets from the scrap plate,
Such conditions are required. That is, a piece having a width D, a length L, and a skin material thickness d
Think of a clad brazing sheet scrap board,
All the brazing material is melted and the entire amount of
Supposed to form fillet-shaped droplets at the bottom of the plate
Then, the mass M of the droplet is given by the following equation (5).
It is. M = ρ · D · L · d (5) Where ρ is the density of the aluminum liquid near the melting point,
2.37 g / cm^ThreeAnd can be put. On the other hand, the fillet-shaped droplet is made to resist surface tension.
To separate from the scrap plate bottom
It is desirable to apply vertical mechanical acceleration to
However, if the vertical acceleration applied to the droplet is A,
When the acceleration A satisfies the following equation (6), the droplet
It will be separated against the tension. M · A ≧ D · T (6) Where T is the surface tension of the aluminum liquid, near the melting point
Can be set to approximately 914 dyne / cm. Therefore, from equations (5) and (6),
Fillet-shaped droplets of molten brazing material accumulated at the lower end of the lap plate
To mechanically separate from the scrap plate, the acceleration
A needs to be determined so as to satisfy the following equation (7). A ≧ D · T / M = T / ρ · LD (7) Here, T is 914 dyne / cm, and ρ is
2.37 g / cm^ThreeAnd based on equation (7), various
Plate thickness, cladding rate, brazing material brazing material
Calculate acceleration required for separation for auto scrap plate
Table 2 shows the results. The width W of the scrap plate is 4c.
m and the length L were constant at 5 cm. [0044] [Table 2]As is clear from Table 2, the filter as a skin material
The smaller the thickness of the cladding, the greater the acceleration required for separation.
It will be good. Where the thickness of the brazing sheet scrap
In most cases, the thickness is generally 0.5 mm or more.
When heating a scrap plate of 5 mm or more, 10
Table 2 shows that acceleration greater than G is required.
Therefore, according to the invention of claim 2, mechanical vibration or impact force is applied.
Is specified as 10 G or more. Further, according to the present invention, for separating droplets,
Timing of starting to apply mechanical vibration or impact force
The conditions are defined, which will be described next. Brazing sheet The surface of the scrap plate
The brazing material melts and flows down along the plate surface,
Only when fillet-shaped droplets are formed at the bottom of the plate
If mechanical acceleration is applied quickly, fillet-shaped droplets
Minimize the diffusion of brazing material components into the core material
Thus, efficient separation and recovery of the core material and brazing material can be achieved. This
Determination of the time of formation of fillet-like droplets such as
Although it is most certain that this will be the case,
For some characteristic change instead of visual observation for power and automation
It is preferable that the judgment be automated. For this purpose
Lighters and others have found that the relationship between various properties and the formation of fillet-like droplets
Investigating the relationship, the high-frequency current flowing through the heating coil
Of the anode voltage of the oscillation tube of the high-frequency oscillator to generate
If it is controlled to be constant, the change in the anode current of the oscillation tube
Burn-off of brazing material on brazing sheet scrap
I found out that I could understand. That is, the anode current of the oscillation tube is set in the crucible.
Depends on the amount of scrap charged into
Not only exist, but also the reluctance
(Magnetic susceptibility). Especially clad material
In brazing sheet scrap, as shown in FIG.
In addition, immediately after the start of induction heating, the anode current increases,
After that, the relative permeability decreases as the brazing material on the surface melts.
The anodic current decreases from the maximum value and burns out
Termination stops the decrease in relative permeability and the anode current is constant
It turned out to calm down to the value of. That is, FIG.
Is 1.3 mm double-sided clad material (cladding ratio per side 1
5.5%) brazing sheet scrap
And the anode voltage of the oscillation tube was 8.8
Anode when high-frequency induction heating is performed at a constant kV
FIG. 2 shows a change in current, and FIG.
It turns out that the transition of the anode current is shown. Note that in FIG.
The number (%) in the figure is formed at the bottom of the scrap plate
Except for the area of fillet-like droplets, wax on the scrap plate surface
The thickness reduction rate of the material is shown as the brazing material separation rate at each point in time.
It was done. As described above, the anodic current shows a unique change process.
From where the brazing material melts down
By grasping the situation and applying acceleration at the appropriate time
To separate the brazing material efficiently,
It can be advantageous for recovery and reuse. In the case of the method according to the invention, the heating coil is vertical.
Spiral around the crucible around a simple axis
Because it is arranged, the magnetic field lines of the induction magnetic field by the heating coil
The direction is the direction along the vertical axis direction of the crucible. one
The scrap plate in the crucible is set up almost vertically
For each scrap plate, the magnetic field lines are
Along the plate surface of the clap plate, make it orthogonal to the thickness direction.
Into the interior of the In this state, it was charged
Let w be the weight of the scrap and t be the thickness of the scrap
For example, in a uniform magnetic field, the number of lines of magnetic force is proportional to w / t. Therefore, the anode current decreases from the maximum value.
If the amount is ΔI, ΔI · t / w is the current per number of lines of magnetic force.
The amount of decrease (normalized amount of current decrease).
You. And the current reduction standardized per number of magnetic field lines
The value of the small amount (ΔI · t / w) is 10^-3After crossing
And when the anode current value has fallen, acceleration is added
Efficiency to the extent that brazing material separation is satisfactory
It turned out that it could be. Here, "The anode current value decreases
Specifically, the timing of "cutting time" is
Judgment is made when the current drop of the capacitor becomes 0.025 A or less.
be able to. Therefore, in the present invention, the current decrease amount ΔI
The following equation (8) ΔI · t / w> 10^-3      (8) And after 10 seconds of the anode current value
At the time when the decrease of
Apply mechanical vibration or impact force with acceleration of G or more
I decided. [0052] 【Example】 [Example 1] As scrap, a thickness of 0.1 to 0.4 m
m of double-sided clad brazing sheet of various thickness
Veneer (width 40mm x length 50mm) vertically in a crucible
Stand up and spiral around an axis perpendicular to the crucible
200 kHz, 400 kHz,
Induction of high frequency by passing various high-frequency currents of 5.35 MHz
Heating was performed. And the surface material (brazing material) melts down
Reducing the thickness of the area excluding the fillet-shaped droplet at the bottom
Checked by volume. Table 3 shows the results. In Table 3
Is the current penetration depth δ at each frequency according to equation (2).
Is calculated together with the critical plate thickness t that satisfies the equation (4).
I will show you. Here, at 200 kHz and 400 kHz
When the anode voltage of the oscillation tube is set at a constant 10 kV,
If the burn-through time is about 40 seconds with a small plate thickness,
It is about 2 minutes with a thick one, while 5.35MHz
In, the anode voltage is fixed at 6 kV and the burn-through time
Was about 10 seconds at any plate thickness. [0053] [Table 3]As shown in Table 3, the current penetration depth δ
The limit thickness t determined by the above equation (4), that is, the power input
A class with a thickness greater than the critical thickness t that maximizes the force density
In the case of a paddle board, the actual thickness of the skin
The thickness has caused a decrease in plate thickness, that is, burn-through.
Erosion from brazing material to core material during burn-through
Is presumed to have occurred partially. Such a result
However, considering the collection and reuse of core material only, brazing material
(Skin material) was efficiently melted and separated.
You. Here, the limit at 200 kHz and 400 kHz
The plate thickness t of the field is 0.90 mm and 0.65 mm, respectively.
However, a thinner 0.5 mm thick cladding material is sufficient.
Was not able to melt and separate the surface cladding material (brazing material)
I understand. Similarly, the limit thickness t at 5.3 MHz is 0.18 m.
m, in which case each clad material has a critical thickness
Since it is thinner than t, the surface skin material is sufficiently separated by melting.
It turns out that it was not obtained. However, in the case of the conventional method, 5-6
If it is not thicker than about mm
Separation is difficult and therefore much more
It is possible to separate brazing material even if it is thin.
You. [Example 2] In this example, the liquid of the molten brazing material was used.
Verification of acceleration addition conditions for droplet separation
is there. That is, thickness 2.6 mm, width 50 mm, length 6
5 mm double-sided clad material (cladding rate per side 15.5
%) As in Example 1.
House it vertically in the crucible and hang it around the crucible.
A heating coil spirally wound around a straight axis,
High frequency of 200kHz with constant 10kV anode voltage of oscillation tube
Wave current and high-frequency electromagnetic induction heating for 170 seconds
Was. And burn-off of the surface brazing material and liquid pool at the lower end
Immediately after visually confirming fillet formation
5G, 10G, 15G, 20G
Apply for 10 seconds at a frequency of 50 Hz at various accelerations.
Under some conditions, it was added for 30 seconds. The sample
In order to prevent the protrusion and maintain the vertical state,
A sample holding jig was applied. And the weight of the base plate and the height
Frequency induction heating-The difference from the weight after mechanical vibration
The rate of weight loss on the board was determined. The results are shown in Table 4.
You. The experiment for each condition was performed twice or more.
Was performed three times. [0056] [Table 4] In the case of this embodiment, the size of the clad plate
The required acceleration obtained from the calculation is approximately 2G or more.
However, as is apparent from Table 4, the addition of 5G is actually performed.
Even at speed, the amplitude of the clad plate is reduced,
No separation could be achieved. On the other hand, high acceleration of 10G or more
Then, a weight reduction rate close to 31% of the amount of skin material on both sides is obtained.
And almost all of the surface material (brazing material) could be separated.
You can see that. [Embodiment 3] In this embodiment, a plurality of
Sheet scrap plate in the same crucible at the same time
Melting of surface brazing material by high frequency induction heating
Separation of fillet-like droplets by applying mechanical vibration
This is an example. That is, various thicknesses as shown in Table 5
Now, about the brazing sheet scrap with the clad rate
The same clad thickness and the same clad ratio
Approximately vertically in the same crucible about 300g to 500g
And high lap under the conditions shown in Table 5.
Wave induction heating and mechanical vibration addition were performed. From the original plate
Of weight loss after induction of high frequency induction heating and mechanical vibration
Are shown in Table 5. [0059] [Table 5] In order to perform efficient separation as described above,
Although acceleration of 10G or more is desirable,
If the loading plate is loaded at the same time, especially the charge amount increases
Then, in order to reduce the influence on peripheral equipment members,
In addition, from the perspective of preventing the charged material from scattering,
The lower the speed, the better. And add high acceleration
If the addition time was shortened or the frequency of vibration was increased
Combined with induction heating conditions such as heating input and heating time
It is desirable to apply appropriate conditions depending on the
Therefore, high separation and recovery efficiency of brazing material can be achieved.
Wear. The conditions of each example in Table 5 are also determined from such a viewpoint.
In all cases, the brazing filler metal was efficiently used.
It can be seen that they were separated well. [Embodiment 4] In this embodiment, a high-frequency oscillation tube
Changes in the anode current of the brazing sheet
Case of detecting burn-through of brazing surface brazing material
It is shown. That is, various plate thicknesses, various claddings
Rate of brazing sheet scrap in various loading amounts
It is inserted almost vertically into the crucible, and the anode voltage of the oscillation tube is 8.8k.
200kHz or 400kHz frequency at constant V
High-frequency current to the heating coil to reduce the anode current of the oscillation tube.
The normalized value (ΔI · t / w) of the small amount ΔI is 10^-3Over
And after the anode current value has fallen for about 10 seconds
When the current drop of
An experiment was performed to add vibration. The vibration conditions are
Speed 10G, frequency 50Hz, vibration addition time 30sec
It is. The weight loss rate of scrap after vibration was investigated.
Table 6 shows the results. [0063] [Table 6] As shown in Table 6, in each case, the anode
Normalized value of current decrease (ΔI · t / w) exceeds 10 -3
Later and the anode current value has fallen to a
Due to the addition of vibration when the lower part becomes 0.025 A or less
It can be seen that the brazing material was almost certainly separated. [Embodiment 5] This embodiment is a modification of the present invention.
Brazing sheet scrap to meet all the conditions
1 shows an example in which semi-solid separation was performed. That is, a 1.3 mm thick double-sided
Braid made of steel (cladding rate 15.5% per side)
505g of jing sheet scrap is placed almost vertically in the crucible
And centered around an axis perpendicular to the crucible
200k frequency heating coil wound spirally
Hz high-frequency current at an anode voltage of the oscillation tube of 8.8 kV
Then, high-frequency induction heating was performed. In this process, the oscillation tube
The anodic current reaches 1.60A from the initial 1.35A
After that, it gradually decreases, and when it reaches 1.10A, the acceleration
Apply 10G, 50Hz vertical vibration for 10 seconds
Was. Here, the anode current decrease amount ΔI at the time of adding vibration
(= Anode current maximum value-Anode current value when vibration is applied) is 0.5
A, the standardized value (ΔI · t / w) is 1.3 × 10
^-3Therefore, in this example, the anode current reduction amount is normalized.
Value is 10^-3And after the anode current value has fallen
When the decrease becomes less than 0.025A per 10 seconds
This means that vibration was added. As a result, skin material (brazing material)
The weight loss rate due to the separation was 30.7%,
Separation close to the desorption rate was achieved. In this embodiment, the original plate before separation is
The chemical composition of the skin material (brazing material) and the core material, and the separated skin material (filtration)
Table 7 shows the results of analyzing the chemical components of the core material and the core material.
In Table 7, 90% of skin material (brazing material) is separated and removed from the base plate.
The calculated values of the chemical components assuming that
You. [0068] [Table 7]From Table 7, it can be seen from the chemical components that the recovered wick after separation was
Materials that are slightly mixed in the brazing material and recovered brazing material
But almost ideal separation was achieved from the viewpoint of weight change.
It turns out that there is. [0070] The brazing sheet scraper of the present invention
According to the semi-solid separation method of the brazing sheet,
Is the brazing material that is the skin material on the wrap surface rapidly from the core material?
And efficient separation, especially in the presence of brazing filler metals
Is it possible to obtain a minimum amount of core material recovery material?
The core material as the core material of the brazing sheet
Can be used, and the separated brazing material
However, depending on the separation conditions, the filter may be close to the brazing filler metal component before separation.
Brazing material can be obtained.
Can be reused as a brazing sheet skin material
No, it is possible to directly replace the brazing sheet scrap.
Cycle to reduce brazing sheet manufacturing costs
Can be reduced. According to the method of the present invention,
More about thin brazing sheet scrap
Material can be separated efficiently, and
It is also possible to use the group effectively.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example of a situation in which the method of the present invention is implemented.
FIG. 2 is a schematic vertical cross-sectional view shown together with a device configuration for implementation. FIG. 2 is a graph showing a change in anode current of an oscillation tube for high-frequency induction heating in a state where the method of the present invention is performed. [Description of Signs] 1 crucible 2 heating coil 6 brazing sheet

Continuation of the front page (56) References JP-A-8-73955 (JP, A) JP-A-8-13049 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22B 1 / 00-61/00

Claims (1)

(57) [Claims 1] A high-frequency current is applied to a heating coil arranged so as to spirally surround a crucible around a vertical axis, and aluminum in the crucible is induced by induction heating. In a semi-melting separation method of heating an alloy brazing sheet scrap, melting the brazing material by the difference in melting point between the brazing material of the brazing sheet scrap and the core material, and melting and separating only the surface brazing material from the core material, 80% of the total weight of the scrap
The above scrap is placed in a crucible so as to stand up to an angle of 60 degrees or more from the horizontal plane, and the frequency f (Hz) depends on the thickness t (mm) of the brazing sheet scrap. A high-frequency current satisfying the following equation t ≧ 40.4 (1 / f) ^1/2 is supplied to the heating coil to melt the brazing material on the surface of the brazing sheet by high-frequency induction heating. The anode voltage of the oscillating tube for generating a high-frequency current for induction heating is kept constant, and the anode current of the oscillating tube increases from the start of induction heating to the maximum value after reaching the maximum value. The reduction amount ΔI (mA) of the anodic current satisfies the following expression ΔI · t / w> 10 ⁻³ depending on the thickness t (mm) of the brazing sheet scrap and the total weight w (g) of the loaded scrap material. Became In and when the decrease per 10 seconds of the anode current value is equal to or less than 0.025 A, acceleration 1
A method for semi-molten separation of a brazing sheet scrap, which comprises applying a mechanical vibration or impact force of 0 G or more to separate a molten brazing material from a core material.