JP4456014B2 - Die casting mold degassing apparatus and die casting mold apparatus - Google Patents

Description

  The present invention relates to a die-casting die venting device having a venting passage communicating with a cavity of a die-casting die and the structure of the die-casting die device.

  2. Description of the Related Art Conventionally, as a die casting mold gas venting device (chill vent; hereinafter referred to as a gas venting device), a serpentine gas vent passage communicating with a cavity of a die casting die is provided on a die-matching surface, , Be: 0.15-2.0 mass%, Ni: 1.0-6.0 mass%, and Co: at least one selected from 0.1-0.6 mass%, the balance being substantially In addition, there is a copper alloy having a Cu composition, a hardness of 180 or more in Brinell hardness HB, and a thermal conductivity of 0.2 cal / cm · s · ° C. or more. In addition, a cooling pipe is provided on the outer periphery of the meandering gas vent passage (see, for example, Patent Document 1).

Japanese Patent No. 3025656 (Claim 1, Claim 2, FIG. 4)

  In the conventional degassing apparatus, since the entire degassing apparatus is made of a copper alloy containing beryllium (Be) or the like, it is compared with the steel material used as a material constituting a general degassing apparatus. There is a problem that it tends to be expensive.

  Moreover, when the cooling pipe is installed, there is a problem that the manufacturing process of the degassing device is likely to be complicated.

  Further, when the gas vent passage is formed in a meandering shape, there is a problem that the processing cost becomes expensive.

  The present invention has been made to solve the above-mentioned problems, and has the same cooling performance as a beryllium copper alloy degassing apparatus in which a cooling pipe is installed, but also the beryllium copper alloy. An object of the present invention is to provide a gas venting device that can be manufactured at a lower cost than a manufactured gas venting device.

A degassing device for a die casting mold according to the present invention includes a degassing passage communicating with a cavity of a die casting die, and is formed on a base material made of a steel material and a portion of the base material in contact with the degassing passage. The surface layer made of a material having a high thermal conductivity higher than that of the base material, the linear expansion coefficient of the material constituting the base material, and the linear expansion coefficient of the material constituting the surface layer between the base material and the surface layer And an intermediate layer made of a material having a linear expansion coefficient between.

  In particular, the surface layer is made of Cu, W, or an alloy of Cu and W. Furthermore, the shape of the degassing passage is a smooth shape, a ridge shape having a stepped portion, or a multi-stage uneven shape.

The die-casting die apparatus according to the present invention includes a gas vent passage communicating with the cavity, and has a plate material made of a steel material in the gas vent passage portion and a steel material formed at a portion in contact with the gas vent passage. The laminated board which consists of a high heat conductive board with high conductivity is arrange | positioned, It is characterized by the above-mentioned.

  The die-casting die apparatus according to the present invention includes a gas vent passage communicating with the cavity, and is characterized in that a single plate made of a high heat conductive plate is disposed at a portion in contact with the gas vent passage.

  According to the degassing device for a die casting mold of the present invention, it has a cooling performance equivalent to that when the entire degassing device is made of a high thermal conductivity material, and can more reliably prevent the molten metal from being flushed, And the effect which can be manufactured cheaply is acquired.

  According to the die casting mold apparatus of the present invention, the degassing part can be manufactured at a low cost, and the flushing of the molten metal can be surely prevented, and the degassing part can be applied to the die casting mold main mold. Attachment / removal becomes easy, and the time for assembling can be shortened.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

Embodiment 1 FIG.
1 is a perspective view showing a degassing apparatus for a die casting mold according to Embodiment 1 of the present invention. A gas venting apparatus 100 according to the present embodiment includes a base material 101 made of a pair of steel materials that is a main part of the gas venting apparatus, and a high thermal conductivity formed in a portion of the base material 101 that is in contact with the gas vent passage 102. And a surface layer 103 made of a rate material.

  Here, the die casting method will be described with reference to FIG. In the die casting method, molten metal such as aluminum, zinc, magnesium, or copper is poured into the sleeve 201 of the die casting mold apparatus 200, and the plunger tip 202 is moved in the left direction in the drawing at a high speed through the gate 203. In this method, molten metal is filled into the cavity (void) 204 of the mold at a high speed to obtain a casting with good shape transfer accuracy. That is, in the die casting method, molten metal is filled into the mold cavity 204 at a high speed of about 30 to 70 m / s. Here, if the gas in the cavity 204 is not properly vented, the pressure in the unfilled area in the cavity (hereinafter referred to as the back pressure) is increased by compressing the gas without escape space as the cavity filling rate increases. It will rise exponentially. This leads to an increase in the size of gas defects entrained in the molten metal, leading to a reduction in product quality.

  For this reason, usually, a method is adopted in which a gas vent passage 205 is provided at an appropriate position in the mold and the gas in the mold is released so that the back pressure does not increase. The shape of the gas vent passage 205 is such that the larger the passage area is, the shorter the length is, and the closer the shape is to a straight tube, the smaller the exhaust resistance becomes, and the gas in the mold can be discharged efficiently. On the other hand, when the passage shape has a small exhaust resistance as described above, there is a problem that the molten metal filled in the mold at a high speed is likely to be ejected to the outside of the mold (this phenomenon is called “flash”).

  Therefore, in consideration of the balance between the two, the following means have been considered so that the molten metal does not flush, that is, the solidification of the molten metal can be completed while passing through the gas vent passage. For example, in an aluminum die casting mold (die casting machine mold having a clamping force of 350 to 500 tons), the gap d as shown in FIG. 3 is about 0.4 mm, the length L is about 160 mm, and the width is about 60 mm. A degassing device (chill vent) 300 having a meandering (θ = 90 degrees) degassing passage 305 is often used (however, the size and shape are appropriately changed depending on the volume and shape of the product). In order to further reduce the exhaust resistance, a degassing device made of copper alloy containing beryllium or the like with high cooling efficiency capable of expanding the gap d of the degassing passage 305 to about 1 mm is used. In either case, the cooling pipe 301 is provided.

  However, the time for the molten metal to pass through the degassing passage is a very short time of 100 ms or less, and since the gap d is 1 mm or less, the heat capacity of the molten metal passing through the degassing passage is relatively small. . The inventors pay attention to this point, and think that it is limited to the outermost surface of the gas venting device that is involved in the transfer of heat transfer with the molten metal, and a base made of a steel material as shown in FIG. A degassing apparatus 100 having a relatively thin surface layer 103 made of a high thermal conductivity material on the very surface of the material 101 was manufactured, and its effect was verified.

  In the degassing apparatus 100 used for the verification of the present embodiment, the meandering angle θ of the degassing passage 102 is 180 degrees (that is, a smooth surface), the gap d is 0.5 mm, the length L is 250 mm, and the groove width w is 60 mm. It is. S45C, which is a general carbon steel for mechanical structures, is used as the base material 101 which is a main part of the gas venting apparatus, and Cu (copper; thermal conductivity 390 W / m) which is a material having high thermal conductivity as the material of the surface layer 103. K) and W (tungsten; thermal conductivity 200 W / m · K) were used. The surface layer 103 was formed by thermal spraying, and the film thickness was set in the range of 0.1 to 2.5 mm. The gas venting apparatus 100 manufactured in this way was installed so as to face the die mating surface of the die casting mold at a position communicating with the final filling area of the cavity 204 of the die casting mold as shown in FIG. Then, 1.0 kg of molten aluminum alloy (ADC12) was actually injected at an injection speed of 1.5 m / s, and flashing occurred in all 10 shots under the conditions 1-1 to 1-12 shown in Table 1 below. The number of times was measured. Further, as a comparative material, a single-structure degassing device made of SKD61 (HRC49), which is a hot tool steel usually used for die casting molds, and a single-structure degassing die made only of a high thermal conductivity BeCu alloy The equipment was also verified at the same time. The results are shown in Table 1.

  As can be seen from Table 1, in the degassing apparatus 100 in which S45C, which is a general carbon steel for mechanical structure, is used as the base material 101 of the degassing apparatus main body portion and Cu (copper) is formed as the surface layer 103, the surface layer When the film thickness of 103 exceeds 0.5 mm (No. 1-2), the effect of suppressing the flash appears, and when the film thickness is 1.0 mm or more (No. 1-3 to 1-6), the flash caused by the film thickness difference It was found that there was no difference in the degree to which it occurred. It was also found that the cooling performance equivalent to that of the degassing device (Comparative Example 3) in which the entire degassing device was composed of BeCu was obtained even though only the surface layer 103 was composed of a high thermal conductivity material.

  Furthermore, in the degassing apparatus 100 shown in the present embodiment, the degassing apparatus having a film thickness exceeding 1.0 mm (Nos. 1-3 to 1-6) although no cooling pipe is provided. Showed the same cooling performance as the BeCu gas venting device with cooling water shown in Comparative Example 4. This is because, during die casting, a water-soluble release agent is applied to the cavity surface after the casting is taken out from the die casting mold, but the heat capacity of the surface of the degassing device is relatively small. This is probably because a cooling effect equivalent to that of the cooling pipe is obtained by application.

  On the other hand, even in a degassing apparatus in which S45C, which is carbon steel for mechanical structure, is used as the base material 101 of the degassing apparatus main body and W (tungsten) is formed as the surface layer 103, the film thickness is 0.5 mm (No. 1). When it exceeds -8), it was found that a flash suppression effect was produced, and when the film thickness exceeded 1.5 mm (No. 1-10 to 1-12), there was a constant flash suppression effect regardless of the film thickness.

  In the above verification, as shown in FIG. 4, the gas venting apparatus 100 is attached in a state of protruding from the die casting mold, but the attachment method is not limited to this mode. As long as it is a part communicating with the final filling area of the cavity 204, for example, it may be mounted in a die casting mold as shown in FIG. 5, or may be mounted on a side surface of the die casting mold as shown in FIG. In the present embodiment, the surface layer 103 is formed by thermal spraying. However, as long as a predetermined film thickness can be obtained, the surface layer 103 may be formed not only by thermal spraying but also by plating or vapor deposition.

  Further, in the gas venting apparatus 100 used in the verification shown in Table 1, the base material 101 provided with the surface layer 103 is configured as a separate member independent of the main die of the die casting mold. This is to provide consistency with a meandering gas venting die (FIG. 3) that is generally used conventionally. However, the gas venting device may not be an independent and separate part but may be integrated with the main die of the die casting mold. FIG. 7 shows a cross-sectional configuration of the gas venting apparatus according to the present invention integrated with the die of the die casting mold. The effect of the degassing apparatus configured as described above is also the same as that of the degassing apparatus shown in the first embodiment.

  In the present embodiment, two examples of Cu and W are shown as the material of the surface layer 103, but it is considered that the same effect can be obtained if the heat capacity is the same as these materials. In the present embodiment, the carbon steel for mechanical structure S45C that is generally used is a base material that is a main part of the gas venting device. However, the present invention is not limited to this material. There is no limitation.

Embodiment 2. FIG.
FIG. 8 is a perspective view showing a degassing apparatus according to Embodiment 2 of the present invention. The degassing apparatus 800 according to the present embodiment includes a base material 801 made of a pair of steel materials that is a main part of the degassing apparatus, and a high thermal conductivity formed in a portion of the base material 801 that is in contact with the degassing passage 802. And a surface layer 803 made of a rate material. The shape of the gas vent passage 802 is a hook shape having a stepped portion 804.

  Table 2 shows the verification result of the degassing apparatus according to the present embodiment. In addition, the degassing apparatus 800 used for verification is similar to the degassing apparatus used for verification in the first embodiment, and uses carbon steel for mechanical structure S45C as the base material 801 and is in a portion in contact with the degassing passage 802. A film made of Cu or W was formed in the range of 0.1 to 2.5 mm by thermal spraying. The gap of the gas vent passage 802 was d = 0.5 mm, the length L = 250 mm, the groove width w = 60 mm, and the height H of the stepped portion 804 was 6 mm.

  In the degassing apparatus 100 shown in the first embodiment, since the degassing passage 102 is a smooth surface, it has not been possible to prevent 100% of the molten metal from being flushed. In the case where the surface layer 803 is either Cu or W in the verification experiment, the molten metal flash is shown in the first embodiment in the verification experiment by making the passage into a bowl shape having a stepped portion 804 as shown in FIG. It became possible to prevent more effectively. As shown in Table 2, the heat capacity (calculated value) difference of the surface layer is only about 3% different from the case where the gas vent passage shown in Table 1 is smooth, but the flash deterrence rate is more than that I was found to be deterred. This is because the molten metal that has entered the gas vent passage collides with the stepped portion, and the passing speed decreases, so the time for heat exchange between the molten metal and the mold becomes longer, and the heat transfer from the molten metal to the mold is It is thought that it is for transmitting to a deeper position of the mold.

Embodiment 3 FIG.
FIG. 9 is a perspective view showing a gas venting apparatus according to Embodiment 3 of the present invention. The degassing apparatus 900 according to the present embodiment has a base material 901 made of a pair of steel materials that are the main part of the degassing apparatus, and a high thermal conductivity formed in a part of the base material 901 that is in contact with the degassing passage 902. And a surface layer 903 made of a rate material. In the present embodiment, a high thermal conductivity material is formed on the surface of the base material 901 on which the multi-step uneven portion 904 is formed. In this case, it is possible to more reliably suppress the molten metal flush as compared with the case where the shape of the gas vent passage is made smooth or bowl-shaped. This is because an increase in the contact area with the molten metal is advantageous for heat transfer and a decrease in the speed of the molten metal.

  In the conventional gas venting device (chill vent) as shown in FIG. 3, the number of stages of the gas vent passages is often about 10 stages, but by adopting the configuration according to the present embodiment. Since the number of stages can be reduced as compared with the conventional product (for example, three stages as shown in FIG. 9), it is possible to contribute to a reduction in processing cost.

Embodiment 4 FIG.
FIG. 10 is a perspective view showing a gas venting apparatus according to Embodiment 4 of the present invention. The degassing apparatus 1000 according to the present embodiment has a base material 1001 made of a pair of steel materials that is a main part of the degassing apparatus, and a high heat conduction formed in a portion of the base material 1001 that is in contact with the degassing passage 1002. It is composed of a surface layer 1004 made of an index material (for example, W) and an intermediate layer 1003 made of, for example, a Cu—W alloy formed between the base material 1001 and the surface layer 1004. The intermediate layer 1003 is made of a material having a linear expansion coefficient between the linear expansion coefficient of the material forming the base material 1001 and the linear expansion coefficient of the material forming the surface layer 1004.

In the said Embodiment 1 and 2, it showed that it was effective in flash prevention by forming W into a film directly on the surface of the base material which consists of steel materials. However, when the temperature of the degassing device rises due to the passage of the molten metal, thermal stress is generated at the interface due to the difference in coefficient of linear expansion between the material constituting the substrate and the surface layer. For example, the linear expansion coefficient of a general steel material is 12 × 10 ⁻⁶ [1 / K], and the linear expansion coefficient of W is 4.3 × 10 ⁻⁶ [1 / K]. The coefficient difference is about 3 times, and considerable thermal stress is generated. Since this thermal stress acts in the direction of shearing the interface, there is a problem that thermal fatigue occurs at the interface due to the heating / cooling cycle of the mold, leading to peeling of the surface layer.

Like this structure, between the base material (steel material) 1001 and the surface layer (W) 1004, for example, a Cu—W alloy (linear expansion coefficient 8 × 10 ⁻⁶ [1 / By forming the intermediate layer 1003 made of K]), it is possible to alleviate the generation of thermal stress even when the temperature rises when passing through the molten metal, and the life of the degassing device can be extended.

Embodiment 5 FIG.
FIG. 11 is a perspective view showing a plate material used in a die casting mold according to Embodiment 5 of the present invention. In the present embodiment, a portion that comes into contact with molten aluminum is constituted by a high thermal conductive plate 1101 such as a copper plate, and a portion that comes into contact with a mold on the opposite side is constituted by an iron plate 1102. For example, a rolled plate composed of a laminated plate of a steel plate having a thickness of 2 mm and a copper plate having a thickness of 2 mm is cut into a shape (width 100 mm, length 250 mm) suitable for the degassing portion and die-casted as shown in FIG. It is installed by a fixing member 1103 or the like on the mold tip.

  In this structure, the degassing passage surface in contact with the molten metal is composed of the high heat conductive plate 1101 such as a copper plate, so that even if the thickness is 2 mm as shown in the first embodiment, the flash is suppressed. Is effective. Moreover, since the back is comprised with the iron plate 1102, the intensity | strength can be given to a cooling plate rather than the case where it comprises only a high heat conductive board (copper board etc.). Further, in the present embodiment, since the gas venting portion is formed in a plate shape, as shown in FIG. 12, it can be mounted on the main mold by the slot-in method, which leads to shortening of the mold assembly time.

  The high heat conductive plate 1101 may be a plate made of W or an alloy of Cu and W in addition to a Cu plate.

Embodiment 6 FIG.
FIG. 13 is a perspective view showing a plate material used in the die casting mold according to the embodiment of the present invention. In this embodiment, the portion that contacts the molten aluminum is composed of a high thermal conductive plate 1301 such as a copper plate, and the portion that contacts the mold on the opposite surface is composed of an iron plate 1302. The contact portion is bent into a corrugated shape. For example, a rolled plate composed of a laminated plate of a 2 mm thick steel plate and a 2 mm thick copper plate cut into a shape suitable for the degassing part (width 100 mm, length 250 mm) is corrugated (stepped) by, for example, pressing. 5 mm).

  As described above, by forming the surface of the high thermal conductive plate 1301 in a multi-stage wave shape, it is possible to more reliably prevent molten metal from flashing. In addition, since the gas vent part is configured in a plate shape, multi-stage wave shapes can be formed by press molding, greatly reducing processing costs compared to multi-stage gas vent parts by conventional machining. It becomes possible to do. It should be noted that the same effect can be obtained even if the shape of the gas vent passage is changed to a bowl shape with a stepped portion.

  The high thermal conductive plate 1301 may be a plate made of W or an alloy of Cu and W in addition to the Cu plate.

Embodiment 7 FIG.
FIG. 14 is a perspective view showing a plate material used in a die casting mold according to Embodiment 7 of the present invention. In this embodiment mode, a portion in contact with the molten aluminum is formed with the high heat conductive plate 1401. The high heat conductive plate 1401 is a plate material made of Cu having a thickness of about 20 mm, a width of 100 mm, and a length of about 250 mm, for example. In the above embodiment, the gas vent passage is configured by depositing a high thermal conductivity material (Cu, W) on a base material made of a steel material. However, in this embodiment, the high thermal conductivity material is formed. It is composed of a single plate made of rate material.

  With this configuration, the high thermal conductivity material itself needs to be thicker than the film-formed product, but it can also be attached to the main mold in a slot-in manner as shown in FIG. As shown, it can also be attached directly to the die-cast main body with bolts. Therefore, there is an advantage that it is easy to attach and replace the gas vent passage portion. In addition, the flash of molten metal can be more effectively suppressed by making the shape of the degassing passage portion into a bowl shape having a stepped portion or a multistage shape.

  The high thermal conductive plate 1401 may be a plate made of W or an alloy of Cu and W in addition to a Cu plate.

It is a perspective view which shows the degassing apparatus for die-casting molds concerning Embodiment 1 of this invention. It is sectional drawing which shows a die-cast metal mold | die. It is the perspective view and sectional drawing which show the conventional degassing apparatus for die-casting molds. It is sectional drawing which shows the state which attached the degassing apparatus for die-casting molds concerning Embodiment 1 of this invention to the die-casting mold. It is sectional drawing which shows the other example of the state which attached the degassing apparatus for die-casting molds concerning Embodiment 1 of this invention to the die-casting mold. It is sectional drawing which shows the other example of the state which attached the degassing apparatus for die-casting molds concerning Embodiment 1 of this invention to the die-casting mold. It is sectional drawing which shows the degassing part for die-casting molds concerning Embodiment 1 of this invention. It is a perspective view which shows the degassing apparatus for die-casting molds concerning Embodiment 2 of this invention. It is a perspective view which shows the degassing apparatus for die-casting molds concerning Embodiment 3 of this invention. It is a perspective view which shows the degassing apparatus for die-casting molds concerning Embodiment 4 of this invention. It is a perspective view which shows the board | plate material used for the die-cast metal mold | die which concerns on Embodiment 5 of this invention. It is a perspective view which shows a part of die-casting metal mold | die which concerns on Embodiment 5 of this invention. It is a perspective view which shows the board | plate material used for the die-cast metal mold | die which concerns on Embodiment 6 of this invention. It is a perspective view which shows the board | plate material used for the die-cast metal mold | die by Embodiment 7 of this invention. It is a perspective view which shows a part of die-casting die concerning Embodiment 7 of this invention. It is sectional drawing which shows the die-cast metal mold | die which concerns on Embodiment 7 of this invention.

Explanation of symbols

100 degassing apparatus, 101 base material, 102 degassing passage, 103 surface layer,
200 Die casting apparatus, 201 Sleeve, 202 Plunger tip,
203 sprue, 204 cavity, 205 degassing passage, 800 degassing device,
801 Substrate, 802 Degassing passage, 803 Surface layer, 804 Stepped portion,
900 Degassing device, 901 base material, 902 degassing passage, 903 surface layer,
904 concavo-convex part, 1000 degassing device, 1001 base material, 1002 degassing passage,
1003 Intermediate layer, 1004 Surface layer, 1101 High heat conduction plate, 1102 Iron plate,
1301 High heat conduction plate, 1302 Iron plate, 1401 High heat conduction plate.

Claims (10)

In a degassing apparatus for a die casting mold including a degassing passage communicating with a cavity of a die casting mold, from a base material made of a steel material and the base material formed on a portion of the base material in contact with the degassing path A surface layer made of a high thermal conductivity material having high thermal conductivity, and between the base material and the surface layer, the linear expansion coefficient of the material constituting the base material and the linear expansion coefficient of the material constituting the surface layer A degassing device for a die-casting mold, comprising an intermediate layer made of a material having a linear expansion coefficient between the two. 2. The degassing die degassing apparatus according to claim 1, wherein the surface layer is made of Cu, W, or an alloy of Cu and W. The degassing device for a die casting die according to claim 1 or 2, wherein the shape of the degassing passage is smooth. The degassing device for a die casting die according to claim 1 or 2, wherein the shape of the degassing passage is a bowl shape having a stepped portion. The degassing device for a die casting die according to claim 1, wherein the shape of the degassing passage is a multi-stage uneven shape. In a die-casting die apparatus having a gas vent passage communicating with a cavity, a degassing passage portion is formed by degassing a laminated plate comprising a plate material made of a steel material and a high thermal conductivity plate having a higher thermal conductivity than the steel material. A die-casting die apparatus characterized in that the passage surface is arranged to be composed of the high thermal conductive plate. The die-cast mold apparatus according to claim 6, wherein the high thermal conductive plate is made of Cu, W, or an alloy of Cu and W. 8. The die casting mold apparatus according to claim 6, wherein the shape of the gas vent passage is smooth. The die-casting die device according to claim 6 or 7, wherein the shape of the gas vent passage is a bowl shape having a stepped portion. The die casting mold apparatus according to claim 6 or 7, wherein the shape of the gas vent passage is a multi-stage wave shape.

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