JP4506492B2 - Melting / solidifying work fixing agent and machining method using the same - Google Patents

Description

The present invention relates to a melting / solidifying workpiece fixing agent that fixes a workpiece by utilizing its own melting and solidification, and a machining method using the same.

This type of melting / solidifying workpiece fixing agent fixes workpieces made of materials such as stainless steel, non-ferrous metals, ceramics, etc. that cannot use the magnetic workpiece fixing method, even in this case, especially thin plates and those that are weak and fragile. It is effective when used for machining such as cutting.

As such a machining method, for example, in Patent Document 1, a melting / solidifying workpiece fixing agent made of a thermoplastic resin such as paraffin is heated and melted, and a workpiece (plastic lens) is added to the molten workpiece fixing agent. ), And then the workpiece fixing agent is cooled and solidified to fix the workpiece to the fixing base via the workpiece fixing agent, and machine the workpiece in this state. A machining method is described in which a workpiece fixing agent is heated and melted with hot water, hot air, or the like, and the workpiece is removed from the fixing table.
Japanese Patent Laid-Open No. 11-198814

By the way, when the present inventors examine in detail a machining method for fixing a workpiece using a conventional melting / solidifying-type workpiece fixing agent, the melting / solidifying behavior of the fixing agent may be slow. It has been found that this is a major factor in reducing the workability of machining.

In other words, since conventional paraffins are generally of a very low purity consisting of a mixture of several substances, the temperature difference between the melting start temperature and the melting end temperature of conventional paraffinic fixatives and the solidification start temperature The temperature difference from the solidification end temperature is a considerably large value, for example, exceeding 10 ° C.

In this way, the behavior until the start and end of melting and solidification of the workpiece fixing agent is a slow behavior with a large temperature difference, so solidification starts when the workpiece fixing agent is cooled and solidified when fixing the workpiece. The time from solidification to the end of solidification becomes longer. Similarly, when the work fixing agent is heated and melted when the work is removed, the time from the start of melting to the end of melting becomes longer.
Thereby, the malfunction that workability | operativity of machining falls arises.

In view of the above points, an object of the present invention is to improve the workability of a machining method using a melting / solidifying workpiece fixing agent.

In order to achieve the above object, the invention described in claim 1 is a melting / solidifying type work fixing agent for fixing a work by utilizing its own melting and solidification,
It consists of paraffin or polyethylene glycol, and is characterized in that the temperature difference between the melting start temperature and the melting end temperature is within 2 ° C.

  Here, a method for measuring the melting point of the workpiece fixing agent will be described. FIG. 4 shows a melting point measuring device, and the heating device 10 is an electrothermal type capable of adjusting the temperature rising speed, and heats the heating table 11 placed on the upper surface thereof. The heating table 11 has a metal plate shape, and a ceramic heat-resistant coating layer is formed on the plate-shaped surface.

  The thermocouple 12 is a detection means for detecting the temperature of the heating table 11 and has a good thermal response because of its small heat capacity. The thermocouple 12 is a sticking type that is attached in the vicinity of the workpiece fixing agent 3 on the surface of the heating table 11. In addition, 13 is a magnifier which expands the state of the fixing agent 3, and 14 shows a visual observer.

  First, before officially measuring the melting start temperature of the workpiece fixing agent 3, a small amount, for example, 0.05 to 0.06 grams of the workpiece fixing agent 3 collected from the storage container is placed on the heating table 11. Heat to melt. Then, the temperature of the heating table 11 is immediately returned to near room temperature, and the workpiece fixing agent 3 is solidified. By doing so, the heat of the heating table 11 is easily transmitted to the workpiece fixing agent 3.

  Note that “return to around room temperature” may return to a temperature (30 ° C.) higher than room temperature (25 ° C.). Thus, even if it returns to temperature higher than room temperature (30 degreeC) and measures a melting start temperature, the melting start temperature intrinsic | native to the workpiece | work fixing agent 3 does not change.

Thereafter, the melting point measurement of the workpiece fixing agent 3 is officially started as follows. That is, the heating table 11 is heated at a constant heating rate, for example, a heating rate of 5 ° C. per minute, and a part of the workpiece fixing agent 3 starts to melt, and the color of the workpiece fixing agent 3 changes from white to transparent. that began visually observed in larger mirror 1 3, and input to a computer (not shown) the temperature at which the color of the work fixing agent 3 begins to change transparent and stored. This is defined as the first melting start temperature of the workpiece fixing agent 3.

  Further, the heating is continued, and all the work fixing agents 3 are transparent and melted, and then visually observed with the magnifying glass 13, and the temperatures when all the work fixing agents 3 become transparent are shown in the figure. Enter it in the computer and remember it. This is defined as the first melting end temperature of the workpiece fixing agent 3.

  Next, after returning the heating table 11 to near room temperature again, the second melting start temperature and the melting end temperature are measured by heating at a constant heating rate of 5 ° C. per minute in exactly the same manner. Such a process is repeated a predetermined number of times, for example, five times, and the average value of the five measurement values is set as the melting start temperature and the melting end temperature of the workpiece fixing agent 3, respectively. The melting point in the present invention refers to this melting start temperature.

Note that the temperature at which the work fixing agent begins to solidify after being completely melted and cooled is the solidification start temperature, and the temperature at which solidification of the work fixing agent ends is This is the solidification end temperature. Since the solidification start temperature is substantially the same as the melting end temperature, and the solidification end temperature is substantially the same as the melting start temperature, the temperature difference between the melting start temperature and the melting end temperature of the workpiece fixing agent is within 2 ° C. In some cases, the temperature difference between the solidification start temperature and the solidification end temperature is also within 2 ° C.

As described above, the work fixing agent temperature difference between the melting initiation temperature and melting completion temperature is within 2 ℃ is specifically with paraffin or polyethylene glycol, obtained by increasing these purity be able to.

For example, a work fixing agent in which the purity of normal paraffin having 16 carbon atoms (C ₁₆ H ₃₄ ) is increased to 99% (the same or less by weight) has a melting start temperature: 18 ° C. and a melting end temperature: 18.7 ° C. is there. Therefore, the temperature difference between the start and end of melting can be set to a slight value of 0.7 ° C.

  Further, the purity of normal paraffin comprising normal paraffin having 18 carbon atoms: 91%, normal paraffin having 17 carbon atoms: 6.7%, and normal paraffin having 19 carbon atoms: 2.3% was increased to 99.3%. The workpiece fixing agent has a melting start temperature: 22.5 ° C. and a melting end temperature: 22.8 ° C. Accordingly, the temperature difference between the start and end of melting can be set to a very small value of 0.3 ° C.

Furthermore, as the paraffin in the invention according to the first aspect , paraffin obtained by combining normal paraffin and non-normal paraffin shown in the following (1) to (5) can also be used. In addition,% of the composition ratio is all by weight.

(1) Paraffin composed of the total components of normal paraffin 88.999% and the balance non-normal paraffin “Composition of normal paraffin”
C18 normal paraffin: 0.08%
Normal paraffin with 19 carbon atoms: 0.41%
Normal paraffin having 20 carbon atoms: 1.76%
Normal paraffin having 21 carbon atoms: 5.61%
Normal paraffin with 22 carbon atoms: 10.66%
Normal paraffin having 23 carbon atoms: 14.76%
C24 normal paraffin: 14.50%
Normal paraffin having 25 carbon atoms: 12.42%
Normal paraffin having 26 carbon atoms: 9.08%
Normal paraffin having 27 carbon atoms: 6.58%
Normal paraffin having 28 carbon atoms: 4.04%
Normal paraffin with 29 carbon atoms: 2.88%
Normal paraffin with 30 carbon atoms: 2.09%
C 31 normal paraffin: 1.50%
C32 normal paraffin: 1.02%
C33 normal paraffin: 0.72%
C34 normal paraffin: 0.37%
C35 normal paraffin: 0.24%
Normal paraffin with 36 carbon atoms: 0.14%
Normal paraffin with 37 carbon atoms: 0.08%
Normal paraffin with 38 carbon atoms: 0.05%
As described above, the total component of normal paraffin is 89.99%, and the balance is non-normal paraffin.

  The average carbon number of the paraffin having the composition (1) is 24.74, and the standard deviation of the molecular weight distribution is 2.86. The smaller the standard deviation, the sharper the molecular weight distribution. In addition, the paraffin having the composition (1) has a maximum molecular weight of 534 and a minimum molecular weight of 254. Accordingly, the molecular weight distribution width is 280.

  The melting start temperature of the paraffin having the composition (1) is 50.4 ° C., and the melting end temperature is 51.7 ° C. Therefore, the temperature difference between the melting start temperature and the melting end temperature can be set to a slight value of 1.3 ° C.

(2) Paraffin consisting of 88.64% total components of normal paraffin and the remaining non-normal paraffin “Composition of normal paraffin”
C18 normal paraffin: 0.07%
Normal paraffin with 19 carbon atoms: 0.28%
Normal paraffin having 20 carbon atoms: 1.10%
Normal paraffin having 21 carbon atoms: 3.38%
Normal paraffin having 22 carbon atoms: 6.92%
Normal paraffin having 23 carbon atoms: 10.86%
Normal paraffin having 24 carbon atoms: 12.67%
Normal paraffin having 25 carbon atoms: 12.74%
Normal paraffin with 26 carbon atoms: 11.17%
Normal paraffin having 27 carbon atoms: 9.18%
Normal paraffin having 28 carbon atoms: 6.43%
Normal paraffin with 29 carbon atoms: 4.73%
Normal paraffin with 30 carbon atoms: 3.01%
Normal paraffin with 31 carbon atoms: 2.16%
Normal paraffin with 32 carbon atoms: 1.42%
C33 normal paraffin: 0.98%
C34 normal paraffin: 0.55%
C35 normal paraffin: 0.36%
Normal paraffin with 36 carbon atoms: 0.22%
Normal paraffin with 37 carbon atoms: 0.15%
Normal paraffin with 38 carbon atoms: 0.11%
Normal paraffin with 39 carbon atoms: 0.09%
Normal paraffin with 40 carbon atoms: 0.06%
As described above, the total of normal paraffin components is 88.64%, and the balance is non-normal paraffin.

  The average carbon number of the paraffin having the composition (2) is 25.61, the standard deviation of the molecular weight distribution is 3.05, the maximum molecular weight is 562, and the minimum molecular weight is 254. Accordingly, the molecular weight distribution width 366 is obtained. The melting start temperature of the paraffin having the composition (2) is 52.5 ° C., and the melting end temperature is 53.7 ° C. Therefore, the temperature difference between the melting start temperature and the melting end temperature can be set to a slight value of 1.2 ° C.

(3) Paraffin consisting of 89.57% total of normal paraffin components and the rest non-normal paraffin “Composition of normal paraffin”
Normal paraffin with 19 carbon atoms: 0.09%
Normal paraffin with 20 carbon atoms: 0.34%
Normal paraffin with 21 carbon atoms: 1.31%
C22 normal paraffin: 3.50%
Normal paraffin having 23 carbon atoms: 7.09%
Normal paraffin with 24 carbon atoms: 10.36%
Normal paraffin with 25 carbon atoms: 12.57%
Normal paraffin having 26 carbon atoms: 12.68%
Normal paraffin having 27 carbon atoms: 11.75%
Normal paraffin having 28 carbon atoms: 8.80%
Normal paraffin having 29 carbon atoms: 6.99%
Normal paraffin with 30 carbon atoms: 4.74%
C 31 normal paraffin: 3.41%
C32 normal paraffin: 2.42%
C33 normal paraffin: 1.70%
C34 normal paraffin: 0.93%
C35 normal paraffin: 0.54%
Normal paraffin with 36 carbon atoms: 0.25%
Normal paraffin with 37 carbon atoms: 0.10%
As described above, the total component of normal paraffin is 89.57%, and the balance is non-normal paraffin.

  The paraffin having the composition (3) has an average carbon number of 26.56, a standard deviation of the molecular weight distribution of 2.94, a maximum molecular weight of 520, and a minimum molecular weight of 268. Accordingly, the molecular weight distribution width is 252. The melting start temperature of the paraffin having the composition (3) is 54.6 ° C., and the melting end temperature is 55.6 ° C. Therefore, the temperature difference between the melting start temperature and the melting end temperature can be set to a slight value of 1.0 ° C.

(4) Paraffin composed of 71.11% total of normal paraffin components and the remaining non-normal paraffin “Composition of normal paraffin”
C23 normal paraffin: 0.08%
Normal paraffin having 24 carbon atoms: 0.16%
Normal paraffin with 25 carbon atoms: 0.39%
Normal paraffin with 26 carbon atoms: 0.87%
Normal paraffin with 27 carbons: 1.52%
C 28 normal paraffin: 1.99%
Normal paraffin with 29 carbon atoms: 2.68%
C30 normal paraffin: 3.14%
C 31 normal paraffin: 3.71%
C32 normal paraffin: 3.94%
Normal paraffin having 33 carbon atoms: 4.07%
C34 normal paraffin: 4.37%
C35 normal paraffin: 4.94%
C36 normal paraffin: 5.49%
Normal paraffin with 37 carbon atoms: 6.00%
Normal paraffin with 38 carbon atoms: 5.44%
Normal paraffin with 39 carbon atoms: 4.50%
C 40 normal paraffin: 3.71%
Normal paraffin having 41 carbon atoms: 3.01%
C42 normal paraffin: 2.53%
Normal paraffin having 43 carbon atoms: 1.94%
Normal paraffin having 44 carbon atoms: 1.55%
C45 normal paraffin: 1.06%
C 46 normal paraffin: 0.84%
47 normal carbon paraffin: 0.58%
48 normal carbon paraffin: 0.45%
Normal paraffin having 49 carbon atoms: 0.33 %
Normal paraffin with 50 carbon atoms: 0.32%
Normal paraffin with 51 carbon atoms: 0.26%
Normal paraffin with 52 carbons: 0.21%
Normal paraffin with 53 carbon atoms: 0.19%
Normal paraffin with 54 carbon atoms: 0.17%
Normal paraffin with 55 carbon atoms: 0.15%
Normal paraffin with 56 carbon atoms: 0.13%
Normal paraffin with 57 carbon atoms: 0.11%
Normal paraffin with 58 carbon atoms: 0.09%
Normal paraffin with 59 carbon atoms: 0.08%
C 60 normal paraffin: 0.06%
C 61 normal paraffin: 0.05%
As described above, the total component of normal paraffin is 71.11%, and the balance is non-normal paraffin.

  The paraffin having the composition (4) has an average carbon number of 36.34, a standard deviation of molecular weight distribution of 5.70, a maximum molecular weight of 856, and a minimum molecular weight of 324. Accordingly, the molecular weight distribution width is 532. The melting start temperature of the paraffin of this composition (4) is 72.1 ° C., and the melting end temperature is 73.4 ° C. Therefore, the temperature difference between the melting start temperature and the melting end temperature can be set to a slight value of 1.3 ° C.

(5) Paraffin composed of 75.78% total of normal paraffin components and the rest non-normal paraffin “Composition of normal paraffin”
Normal paraffin with 29 carbon atoms: 0.08%
Normal paraffin with 30 carbon atoms: 0.23%
Normal paraffin with 31 carbon atoms: 0.69%
C32 normal paraffin: 1.36%
C33 normal paraffin: 1.77%
C 34 normal paraffin: 2.02%
Normal paraffin with 35 carbons: 2.21%
Normal paraffin with 36 carbon atoms: 2.41%
Normal paraffin with 37 carbon atoms: 3.02%
Normal paraffin with 38 carbon atoms: 3.58%
Normal paraffin with 39 carbon atoms: 3.52%
40 normal carbon paraffin: 3.94%
Normal paraffin having 41 carbon atoms: 4.13%
C42 normal paraffin: 5.15%
Normal paraffin having 43 carbon atoms: 4.95%
Normal paraffin having 44 carbon atoms: 5.54%
C45 normal paraffin: 4.55%
C 46 normal paraffin: 4.71%
47 normal carbon paraffin: 3.53%
48 normal carbon paraffin: 3.08%
Normal paraffin having 49 carbon atoms: 2.38%
C 50 normal paraffin: 2.16%
Normal paraffin with 51 carbon atoms: 1.68%
Normal paraffin with 52 carbons: 1.35%
Normal paraffin with 53 carbon atoms: 1.21%
54 normal carbon paraffin: 1.00%
Normal paraffin with 55 carbon atoms: 0.85%
Normal paraffin with 56 carbon atoms: 0.80%
Normal paraffin with 57 carbon atoms: 0.63%
C 58 normal paraffin: 0.59%
Normal paraffin with 59 carbon atoms: 0.49%
C 60 normal paraffin: 0.41%
Normal paraffin with 61 carbons: 0.34%
Normal paraffin with 62 carbons: 0.38%
Normal paraffin with 63 carbon atoms: 0.36%
64 normal carbon paraffin: 0.30%
C 65 normal paraffin: 0.23%
66 normal carbon paraffin: 0.15%
As described above, the total component of normal paraffin is 75.78%, and the balance is non-normal paraffin.

Average carbon number of the paraffin having the above composition (5) is 43.69, the standard deviation of the molecular weight distribution 6.81, the maximum molecular weight is 926, the minimum molecular weight is 408. Therefore, the molecular weight distribution width is 518. The melting start temperature of the paraffin having the composition (5) is 86.2 ° C., and the melting end temperature is 87.9 ° C. Therefore, the temperature difference between the melting start temperature and the melting end temperature can be set to a slight value of 1.7 ° C.

In addition, as the polyethylene glycol in the invention described in claim 1 , the following can be used. For example, polyethylene glycol having an average molecular weight of 1540 has a melting start temperature: 46 ° C. and a melting end temperature: 47.2 ° C. Therefore, the temperature difference between the melting start temperature and the melting end temperature can be set to a very small value of 1.2 ° C.

  Polyethylene glycol having an average molecular weight of 4000 has a maximum molecular weight of 5464, a minimum value of 1689, a number average molecular weight Mn: 2866, a weight average molecular weight Mw: 2935, a Z average molecular weight Mz: 3004, a molecular weight distribution dispersity ( Mw / Mn: 1.0238, Mz / Mw: 1.0237, showing a sharper distribution closer to 1. The polyethylene glycol having an average molecular weight of 4000 has a melting start temperature: 55.1 ° C. and a melting end temperature: 56.4 ° C. Therefore, the temperature difference between the melting start temperature and the melting end temperature can be set to a very small value of 1.3 ° C.

As described above, when the workpiece fixing agent having a temperature difference between the melting start temperature and the melting end temperature of 2 ° C. or less is used as the workpiece fixing agent, the workpiece fixing agent in the liquid state is cooled and solidified to fix the workpiece. When the work fixing agent that has solidified and is in a solid state is heated and melted to remove the work, it is only necessary to heat and cool the work fixing agent corresponding to a slight temperature change of about 2 ° C.

Therefore, the work fixing work and the work removing work can be efficiently performed in a short time. In addition, since the temperature change width for heating and cooling the workpiece fixing agent is small, the thermal expansion change of the workpiece is also small, which can improve the machining accuracy of the workpiece and reduce the thermal stress on the workpiece material. Material deterioration can also be suppressed.

  By the way, the adhesive strength of the workpiece fixing agent increases as the difference between the melting start temperature and the adhesive surface temperature increases. For this reason, since all the paraffins composed of the above-described compositions (1) to (5) are in a relatively high temperature range where the melting start temperature is 50 ° C. or higher, the difference between the melting start temperature of the workpiece fixing agent and the bonding surface temperature. Can be increased to increase the adhesive strength.

  Here, the method for measuring the adhesive strength of the workpiece fixing agent will be described in detail with reference to FIG. 5. FIG. 5A shows a T-shaped test piece 20 corresponding to the workpiece to be fixed. The material of the T-shaped test piece 20 is SUS304, and its surface roughness is 4.0 Rz. The dimensions of the T-shaped test piece 20 are as shown in FIG.

  FIG. 5B shows an outline of a tensile test method for measuring the adhesive strength of the workpiece fixing agent 3. In this test method, a paraffin having a melting start temperature of 72.1 ° C. and a melting end temperature of 73.4 ° C. (paraffin having the composition (4) described above) is used as the workpiece fixing agent 3. The material of the fixing base 21 is SUS440, and its surface roughness is 3.0 Rz.

  A T-type test piece 20 is fixed to the surface of the fixing base 21 with a workpiece fixing agent 3 (paraffin having the above composition (4)), a push-pull gauge 22 is connected to the T-type test piece 20, and the push-pull gauge 22 is connected. The tensile force F when the T-shaped test piece 20 is detached from the fixed base 21 is measured by applying the tensile force F. This is the adhesive strength of the workpiece fixing agent 3.

  Then, when the surface temperature of the fixing base 21, that is, the adhesive surface temperature of the workpiece fixing agent 3 was changed and the adhesive strength of the workpiece fixing agent 3 was measured, the melting start temperature and the adhesive surface of the workpiece fixing agent 3 were as follows. The measurement result was obtained that the greater the difference from the temperature, the greater the adhesive strength.

That is, when the adhesive surface temperature was 25 ° C. (the difference between the melting start temperature and the adhesive surface temperature was 47.1 ° C.), the adhesive strength was 6 kg / cm ² .

When the adhesive surface temperature was 17 ° C. (the difference between the melting start temperature and the adhesive surface temperature was 55.1 ° C.), the adhesive strength was 11 kg / cm ² .

When the adhesive surface temperature was 11 ° C. (the difference between the melting start temperature and the adhesive surface temperature was 61.1 ° C.), the adhesive strength was 25 kg / cm ² .

  When the T-shaped test piece 20 is fixed with the same adhesive strength, if the difference between the melting start temperature and the melting end temperature of the workpiece fixing agent 3 is large, the workpiece fixing agent 3 must be heated to a high temperature to be melted. So work efficiency will be worse.

  In particular, it takes a long time to heat a large workpiece to a high temperature while the workpiece is attached to a machining apparatus (see FIG. 6 described later) such as wire electric discharge machining, which is a big problem. In such a case, if the difference between the melting start temperature and the melting end temperature is small, the required adhesive strength can be ensured at a low temperature, so that the work time can be shortened accordingly.

Such an effect can be more effectively exhibited when the temperature difference between the melting start temperature and the melting end temperature of the workpiece fixing agent is within 1 ° C. as in the invention described in claim 5 .

In addition, the paraffin or polyethylene glycol limited in the invention of claim 1 has a large work adhesion strength (work fixing force) when solidified, and is non-corrosive to metal, It has the advantage that it is a material with a low environmental impact without concern about pollution.

  For example, Japanese Patent Application Laid-Open No. 2004-156033 introduces a fixing agent and a fixing method mainly composed of a salicylic acid derivative, but this substance has a strong odor and toxicity and is not suitable for use in a processing field. That is, if the fixing agent is heated at the time of fixing the workpiece, a bad odor is generated, so that a special exhaust and removal device is required. Still, odors are attached to clothes, which is disliked by workers.

  In addition, the pollution treatment of the fixing agent that occurs when the fixed workpiece is removed and cleaned is very troublesome. For this reason, it becomes a factor of processing cost increase. The material price of the salicylic acid derivative itself is also higher than that of paraffin or polyethylene glycol.

  In the present invention, the paraffin and polyethylene glycol used as a workpiece fixing agent are not only toxic to the material itself, but also do not generate harmful substances during heating and fixing, and the workpiece can be removed and post-washed with no concern about pollution. Cleaning solution is sufficient.

  For example, a cleaning liquid stock solution containing a neutral surfactant, specifically, a cleaning liquid obtained by diluting a liquid of a trade name: Daikaclean S (manufacturer: Albose Co., Ltd.) with about 10 times water is made higher than the melting point of the fixing agent. By heating and immersing the workpiece in this cleaning solution, the paraffin adhering to the workpiece can be removed.

  Thereafter, if the workpiece is further immersed in warm water having a melting point or higher, the paraffin slightly attached to the workpiece can be removed. In the cleaning liquid after cleaning the workpiece, the paraffin that has melted solidifies and floats on the surface when the temperature returns to room temperature. Therefore, if this is taken out and reheated, the cleaning liquid can be used again for removing paraffin.

  This product name: Daikaclean S is also used as a synthetic detergent for kitchen utensils containing a neutral surfactant, so it does not corrode amphoteric metals such as aluminum and zinc, and is also a problem in terms of pollution and safety. Can be used without

  In addition, since polyethylene glycol is harmless and water-soluble, the workpiece after processing can be washed with water, and the dirty cleaning solution can be disposed of as general industrial wastewater.

  Paraffin or polyethylene glycol is practically easy to adjust the melting point in the temperature range near room temperature, which is easy to melt and solidify.

The invention according to claim 3 is a melting / solidifying type work fixing agent for fixing a work by utilizing its own melting and solidification,
The temperature difference between the melting start temperature and the melting end temperature is within 2 ° C., and the melting start temperature and the melting end temperature are in the range of 18 ° C. to 30 ° C.

According to this, the workability of the machining method using the melting / solidifying workpiece fixing agent is reduced by setting the temperature difference between the melting start temperature and the melting end temperature within 2 ° C. as in the first aspect of the invention. In addition to this, in the temperature range around room temperature , it is only necessary to heat and cool the workpiece fixing agent corresponding to a slight temperature change of about 2 ° C. Change and thermal stress can be reduced more effectively.
As in the invention described in claim 2, in the melting / solidifying workpiece fixing agent described in claim 1, the melting start temperature and the melting end temperature are within the range of 18 ° C to 30 ° C. Is desirable.
Further, the melting / solidifying workpiece fixing agent according to claim 3 may be specifically paraffin or polyethylene glycol as in the invention according to claim 4.

In the invention described in claim 6 , the melting / solidifying workpiece fixing agent (3) according to any one of claims 1 to 5 is brought into contact with the workpiece (1) on the fixing table (2) in a molten state. Let
The workpiece fixing agent (3) is cooled and solidified to fix the workpiece (1) on the fixing base (2), and in this state, the workpiece (1) is machined.
It is characterized by a machining method for removing the workpiece (1) from the fixing table (2) by heating and melting the workpiece fixing agent (3) after the machining.

Thereby, the machining method which can exhibit the effect of Claims 1 thru | or 5 can be provided.

In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

The melting / solidifying workpiece fixing agent is used for fixing a workpiece (workpiece) to a fixing base in machining, but in this embodiment, as the workpiece, an optical semiconductor (for example, a blue light emitting diode) is used. The sapphire substrate is used, and the sapphire substrate is subjected to ultraprecision surface polishing.

FIGS. 1 to 3 are views showing the ultraprecision surface polishing method according to the present embodiment, and the work 1 is a disk-shaped sapphire substrate having a diameter of 50 mm and a thickness of 0.3 mm. The grooved fixing base 2 is formed of a magnetic material such as an iron-based material (for example, S50C, SUS430, etc.) so as to have a rectangular outer shape.

A groove portion 4 for injecting the workpiece fixing agent 3 is formed on the surface of the fixing base 2. The shape of the groove portion 4 is a shape in which a plurality of concentric circular portions and a plurality of radial straight portions are combined as illustrated in FIG. Thereby, since the plurality of concentric circular portions of the groove portion 4 are all in communication with each other by the linear straight portion, when the molten liquid workpiece fixing agent 3 is injected into the groove portion 4 from a specific location, the liquid workpiece fixing is performed. The agent 3 can be injected over the entire area within the groove 4.

Moreover, the workpiece | work fixing agent 3 in the groove part 4 can be made to contact each part of the bottom face part of the workpiece | work 1 equally by setting it as the groove shape which combined the some concentric circle part and the some radial linear part.

A portion of the surface of the fixing base 2 where the groove 4 is not formed becomes a flat portion 2a that directly contacts the workpiece 1 as shown in FIG. As a result, there is no gap between the workpiece 1 and the fixed base 2,
The workpiece 1 can be fixed with respect to the fixed base 2 while maintaining good parallelism.

On the surface of the fixed base 2, a cooling water passage 5 formed of a rectangular concave groove is formed on the outer peripheral side of the maximum circular portion of the groove portion 4. The cooling water passage 5 plays a role of collecting cooling water sprinkled on the surface of the fixed base 2 by a cooling water supply means (not shown) and draining it from the drain port 5a. Here, both cooling water for polishing and cooling water for cooling and solidifying the workpiece fixing agent 3 are used as the cooling water.

As the workpiece fixing agent 3 in this embodiment, normal paraffin having a melting start temperature (melting point): 22.5 ° C. and a melting end temperature: 22.8 ° C. is used. The normal paraffin having such a slight temperature difference between the melting start and the melting end of 0.3 ° C. is specifically a carbon number of 1
The purity of normal paraffin consisting of 8% normal paraffin: 91%, 17 carbon normal paraffin: 6.7%, and 19 carbon normal paraffin: 2.3%.
It can be obtained by increasing to 3%.

Next, the ultra-precision surface polishing process according to the present embodiment will be specifically described. As shown in FIGS. 1 and 2, the workpiece 1 made of a disk-shaped sapphire substrate is used to form the groove 4 and the flat surface 2a on the surface of the fixed base 2.
Put it on top. And after covering the upper surface of the workpiece | work 1 with a protective sheet (not shown), it is about 500.
The gram weight is placed on the workpiece 1 through the protective sheet.

  Thereby, it can avoid that the workpiece | work 1 lifts from the fixed base 2 with the workpiece | work fixing agent 3 of the liquid state mentioned later, Therefore, the lower surface of the workpiece | work 1 can be closely_contact | adhered to the plane part 2a of the fixed base 2 surface without gap.

Here, the protective sheet prevents damage to the workpiece 1 due to the weight, but as the material of the protective sheet, a material having a small adhesive force with the workpiece fixing agent 3, specifically, silicone rubber is suitable.

Next, the fixing table 2 on which the workpiece 1 is placed is placed on an electrothermal hot plate (not shown), the fixing table 2 is heated, and the surface temperature of the fixing table 2 is higher than the melting point of the workpiece fixing agent 3. Temperature 2
Bring to 3 ° C.

Next, the workpiece fixing agent 3 that is completely melted and in a liquid state is injected into the groove portion 4 of the fixing base 2. Here, since the fixing base 2 is preheated to 23 ° C. as described above, it does not solidify when the workpiece fixing agent 3 in the liquid state comes into contact with the surface of the groove portion 4 and remains in the liquid state throughout the groove portion 4. Go around smoothly. The work fixing agent 3 is poured until it fills the groove 4 and comes into contact with the lower surface of the work 1.

In addition, the workpiece fixing agent 3 in a liquid state is accommodated in a metal container formed of a metal such as stainless steel, and the metal container is placed on an electrothermal hot plate and heated to 23 ° C. The workpiece fixing agent 3 always maintains a liquid state inside the metal container.

Next, cooling water having a temperature lower than the melting point of the workpiece fixing agent 3 is supplied into the cooling water passage 5 of the fixing base 2, and the surface of the fixing base 2 is cooled to 21 ° C. with this cooling water. Thereby, the workpiece | work fixing agent 3 in the groove part 4 is solidified, a phase change is carried out from a liquid state to a solid state, and the workpiece | work 1 can be closely_fixed and fixed to the fixed base 2 surface.

Next, the weight and the protective sheet are removed from the fixed base 2. At this time, since the protective sheet is made of silicone rubber having a small adhesive force with the workpiece fixing agent 3, the protective sheet can be easily peeled from the workpiece fixing agent 3.

After that, the fixing table 2 to which the work 1 is fixed is fixed on the electromagnetic chuck table of the polishing machine by electromagnetic force, and 21 ° C. cooling water having a temperature lower than the melting point of the work fixing agent 3 is sprinkled on the work 1. Then, the surface of the work 1 is polished by a predetermined amount (for example, 0.6 microns) with a polishing tool. The cooling water of this polishing process flows into the cooling water passage 5 of the fixed base 2 and then drains from the drain port 5a to the outside of the fixed base 2.

When the polishing of the workpiece 1 is completed, 23 ° C. cooling water which is a temperature higher than the melting point of the workpiece fixing agent 3 is sprinkled on the surface of the workpiece 1. As a result, the workpiece fixing agent 3 is melted into a liquid state, so that the workpiece 1 is fixed by the workpiece fixing agent 3 and the workpiece 1 is fixed to the fixing base 2.
Can be easily removed. In addition, the workpiece | work fixing agent 3 used as the liquid state flows into the cooling water channel | path 5 with cooling water, and is discharged | emitted from the drain port 5a to the fixing stand 2 exterior. The post-cleaning of the workpiece 1 was performed by immersing in the above-mentioned Dica Clean cleaning solution.

As understood from the above description, according to the present embodiment, the workpiece fixing agent 3 in the groove 4 in a liquid state at 23 ° C. is cooled to 21 ° C., so that the workpiece fixing agent 3 is solidified. Can be fixed. And after completion | finish of a process of the workpiece | work 1, the workpiece | work fixing agent 3 solidified at 21 degreeC can be removed from the fixing stand 2 by heating to 23 degreeC and fuse | melting.

In this way, the workpiece 1 is fixed and removed by causing the workpiece fixing agent 3 to undergo a phase change of solidification and melting with a slight temperature change width of 2 ° C. between 23 ° C. and 21 ° C. 1
Can be fixed and removed in a short time, and the workability of machining can be improved.

In addition, since the workpiece 1 is fixed and the workpiece 1 is removed in a temperature range of 23 ° C. and 21 ° C. near room temperature and with a slight temperature change width of 2 ° C., the difference in thermal expansion before and after the processing of the workpiece 1 also occurs. Only a small amount is required. Therefore, the machining accuracy of machining can be improved, and the thermal stress on the material of the workpiece 1 can be reduced to suppress the material deterioration of the workpiece 1.

  In the first embodiment described above, an example in which an optical semiconductor sapphire substrate is used as the workpiece 1 has been described. However, this sapphire substrate is an application example of the workpiece 1, and other than this, stainless steel, non-ferrous metal, ceramics The present invention can be applied to machining of a thin plate made of a material such as the above and a workpiece 1 having a weak strength and fragile.

  Further, in the first embodiment described above, the example in which the workpiece 1 is polished is described. However, the present invention is not limited to the polishing processing, and is also applicable to machining such as wire electric discharge machining and milling. Of course, it can be applied.

(Second Embodiment)
The second embodiment relates to an example in which the workpiece fixing agent of the present invention is applied to wire electric discharge machining. FIG. 6 shows a wire electric discharge machining method according to the second embodiment. The workpiece 1 is formed of a steel material (S50C) in a cube having a width: 100 mm, a depth: 100 mm, and a height: 100 mm.

  In the wire electric discharge machining method according to the second embodiment, as shown in FIG. 7, wire electric discharge machining is performed along a predetermined machining locus from the machining start point 1a of the workpiece 1 toward the machining stop point 1b (primary machining step). ).

  Specifically, in a state where the machining fluid (water) is filled around the workpiece 1, a high frequency voltage is applied by the machining power source 3 connected to the workpiece 1 and the wire 30 by terminals 31a and 31b, and the workpiece 1 is mounted. By moving the placed work table (not shown) along a predetermined machining locus, electric discharge machining is advanced by the wire 1.

  By this wire electric discharge machining, a machining groove 32 having a constant width (for example, 0.3 mm) penetrating from the upper surface 1c to the bottom surface 1d of the workpiece 1 is formed. By repeating the wire electric discharge machining for forming the machining groove 32 a plurality of times, for example, three times, the surface roughness of the machining groove 32 is reduced. A cut-out portion 33 is formed in the center portion of the work 1 by the machining groove 32.

  In the primary machining, the non-machined portion 34 is left unmachined and the electric discharge machining is temporarily stopped at the machining stop point 1b. After the electric discharge machining is stopped, the machining fluid (water) around the workpiece 1 is once removed from the machining apparatus.

  Next, as shown in FIG. 8, a heat-resistant leak-proof tape 35 is attached to the bottom surface 1 d of the work 1 to seal the work groove 32. The leak-proof tape 35 can be formed into a shape that conforms to the shape of the processed groove 32 that has been grasped in advance.

  Next, the magnet rubber heater 36 (FIG. 6) incorporating the electric heater is attached to the other five surfaces excluding the upper surface 1c of the workpiece 1, and the workpiece 1 is heated.

  Here, the heating temperature of the workpiece 1 is a temperature equal to or higher than the melting end temperature of the workpiece fixing agent 3a, specifically 53 ° C. The workpiece heating time from 25 ° C. to 53 ° C. at room temperature was 15 minutes. The work fixing agent 3a is water-insoluble, and is specifically paraffin (paraffin having the composition (1) described above) having a melting start temperature of 50.4 ° C. and a melting end temperature of 51.7 ° C.

  After the workpiece 1 is heated to 53 ° C. or higher as described above, the solid fixing agent 3a is applied to the upper surface 1c of the workpiece 1 and melted. After the fixing agent 3a is melted, a drop prevention plate 37 is placed on the melted fixing agent 3a.

  Subsequently, a water-insoluble conductive workpiece fixing agent 3b is applied to a portion near the unprocessed portion 34, specifically, near the processing start point 1a, in the processing groove 32 of the upper surface 1c of the workpiece 1. Since the workpiece fixing agent 3b uses the same paraffin (paraffin having the composition (1) described above) as the workpiece fixing agent 3a, the melting start temperature is 50.4 ° C. and the melting end temperature is 51.7 ° C. is there.

  However, the workpiece fixing agent 3b is mixed with carbon particles in order to ensure conductivity. Specifically, the workpiece fixing agent 3b is composed of a ratio of 50% by weight of the paraffin having the composition (1) and 50% by weight of carbon particles having an average particle diameter of 5 microns.

  Even if the melted workpiece fixing agents 3a and 3b flow into the machining groove 32, the bottom portion of the machining groove 32 is sealed by the leak-proof tape 35, so that the melted fixing agents 3a and 3b are outside the machining groove 32. It will not sag.

  Thereafter, the magnet rubber heater 36 is removed from the workpiece 1, the workpiece 1 is cooled to 50.4 ° C. or less, which is the melting start temperature of the fixing agents 3a and 3b, and the paraffin constituting the fixing agents 3a and 3b is solidified (solidified). .

  As a work cooling method at this time, natural cooling may be used, or a cloth soaked in water may be attached to the work 1. After the fixing agents 3a and 3b are solidified, both the workpiece 1 and the drop-off prevention plate 37 are cooled to 20 ° C. by filling the processing device with water for processing maintained at a constant temperature of 20 ° C.

As a result, the difference between the melting start temperature (50.4 ° C.) and the bonding surface temperature (20 ° C.) of the fixing agents 3a and 3b becomes 30.4 ° C. Therefore, the bonding strength of the fixing agents 3a and 3b is 5 kg / cm. Guaranteed to ² levels. For this reason, the workpiece cutting part 33 is held without dropping from the main body of the workpiece 1.

  Since the workpiece fixing agent 3b has conductivity, the conductivity of the workpiece cutting portion 33 is ensured even when the remaining unprocessed portion 34 is processed. Therefore, the surface roughness of the unprocessed portion 34 can be satisfactorily finished by electric discharge machining a plurality of times (for example, three times).

  Then, wire electric discharge machining is performed on the unprocessed portion 34 (execution of secondary processing), and the unprocessed portion 34 is excised as shown in FIG. Thereby, the workpiece cutting part 33 can be completely cut from the main body of the workpiece 1. Even in this state, the workpiece cutout portion 33 can be held on the main body of the workpiece 1 by the drop-off prevention plate 37 and the fixing agent 3a. For this reason, it is possible to prevent a problem that the workpiece cutting part 33 is dropped and deformed after being completely cut.

  In order to remove the workpiece cut-out portion 33 after excision of the unprocessed portion 34, the workpiece 1 is immersed in warm water of 51.7 ° C. or higher which is the melting end temperature of the fixing agents 3a and 3b, or the workpiece 1 is again removed with the magnet rubber heater 36. May be heated to 51.7 ° C. or higher.

It is a schematic perspective view of the principal part of the machining apparatus used in 1st Embodiment of this invention. It is AA sectional drawing of FIG. It is a top view of the fixed base of FIG. It is explanatory drawing of the melting | fusing point measuring method of the workpiece | work fixing agent in this invention. (A) is a perspective view of the test piece used for the adhesive strength measuring method of the workpiece | work fixing agent in this invention, (b) is explanatory drawing of the adhesive strength measuring method using the test piece of (a). It is explanatory drawing of the wire electric discharge machining method by 2nd Embodiment of this invention. It is explanatory drawing of the primary process of the wire electric discharge machining method by 2nd Embodiment. It is explanatory drawing of the sticking process of the leak-proof tape after the primary process of the wire electric discharge machining method by 2nd Embodiment. It is a perspective view which shows the workpiece | work after the secondary process of the wire electric discharge machining method by 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Work, 2 ... Fixing stand 3, 3a, 3b ... Work fixing agent.

Claims (6)

A melting / solidifying workpiece fixing agent that fixes the workpiece using its own melting and solidification,
A melting / solidifying workpiece fixing agent, which is made of paraffin or polyethylene glycol and has a temperature difference between the melting start temperature and the melting end temperature within 2 ° C. 2. The melting / solidifying workpiece fixing agent according to claim 1 , wherein the melting start temperature and the melting end temperature are in a range of 18 ° C. to 30 ° C. 3. A melting / solidifying workpiece fixing agent that fixes the workpiece using its own melting and solidification,
A melting / solidifying workpiece characterized in that a temperature difference between a melting start temperature and a melting end temperature is within 2 ° C , and the melting start temperature and the melting end temperature are within a range of 18 ° C to 30 ° C. Fixative. 4. The melting / solidifying workpiece fixing agent according to claim 3 , comprising paraffin or polyethylene glycol. The melting / solidifying workpiece fixing agent according to any one of claims 1 to 4, wherein a temperature difference between a melting start temperature and a melting end temperature is within 1 ° C. The melting / solidifying work fixing agent (3) according to any one of claims 1 to 5 is brought into contact with the work (1) on the fixing base (2) in a molten state,
The workpiece fixing agent (3) is cooled and solidified to fix the workpiece (1) on the fixing base (2), and in this state, the workpiece (1) is machined.
A machining method, comprising: removing the workpiece (1) from the fixing table (2) by heating and melting the workpiece fixing agent (3) after completion of the machining.

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