JP4274788B2 - Gravity casting - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention also relates to gravity casting process.
[0002]
[Prior art]
Gravity casting is a method in which a molten metal such as an aluminum alloy or magnesium alloy is cast into the cavity of a mold by gravity pouring, and the dimensional accuracy is high, the casting structure is dense, and the mechanical properties and durability are improved. In addition to being excellent, the casting apparatus and the mold have a long life, and the equipment cost is relatively low.
[0003]
However, if the mold temperature at the time of casting is too low, the molten metal solidifies in the thin wall part during filling and causes casting defects such as non-rotating, hot water, and nests, and if the mold temperature is too high, the wall thickness has a large heat capacity. A casting defect such as a nest occurs in the part, which becomes a cause of defective casting.
[0004]
As a countermeasure, measure the time from the end of the casting cycle to the start of the next casting cycle and the temperature of the mold immediately before filling the molten metal, and compare the measurement time and measured temperature with the preset time and mold temperature. Then, by adjusting the heating means and the casting cycle time so that the mold reaches the set temperature based on the calculation result, the mold temperature is controlled to a predetermined temperature range and the occurrence of casting defects is prevented. A control method is known (see, for example, Patent Document 1).
[0005]
On the other hand, in the gravity casting method, since the casting in the mold cavity is gradually performed, the molten metal that has flowed in first flows to the tip, so that it solidifies first from the tip and the feeder part solidifies last. It is necessary to make directional solidification proceed, and the generic name of the sprue, runner, etc. including this feeder is the design part, and when the design part is solidified, the mold is opened and the product is taken out. .
[0006]
This plan part is important for ensuring the quality of molten metal by pouring molten metal into the cavity, that is, suppressing the entrainment of air and the generation of oxide when filling, and ensuring the directional solidification toward the feeder part. Part.
[0007]
In addition, the solidification time required from pouring to mold opening, that is, the solidification state that determines the mold clamping time and mold opening time is determined by installing a temperature measurement means such as a thermocouple thermometer in the cavity or mold. A method of grasping the solidification state of a casting based on temperature detection by a temperature measuring means is generally performed.
[0008]
For example, the temperature of the mold when casting a casting with a weight of about 10 kg is gradually increased by the melt heat of the melt filled in the cavity from the gate as shown in the correlation diagram between the mold temperature and the solidification time shown in FIG. Then, after reaching the maximum temperature a, for example, 491 ° C., it gradually descends with the start of solidification of the molten metal in the cavity. The mold temperature b when the mold has reached a solidification temperature at which no deformation or galling occurs, for example, a time t reaching 453 ° C., for example, 210 seconds, is experimentally confirmed and set in advance as a solidification time. The time t at this time can be the end of the coagulation time, that is, the mold opening time. However, the temperature of the mold is low at the start of the casting operation, for example, and the mold temperature gradually rises as the casting operation is repeated, so that there is a variation of about ± 15 ° C. in the mold temperature, for example. Therefore, the mold temperature relative to the true solidification temperature is 438 ° C. to 468 ° C., and the solidification time must be set in consideration of this, and an extra time is set from the time required for the true solidification.
[0009]
[Patent Document 1]
JP-A-6-262337
[Problems to be solved by the invention]
However, the setting of the solidification time until the temperature of the casting drops to a temperature at which the casting does not deform or galvanize even when the mold is opened and released is set based on the time experimentally confirmed in advance. Since each time is artificially set based on the experience and feeling of the casting worker, there are individual differences in the setting of the solidification time depending on the casting worker. In actual casting, uncertain factors such as the atmospheric temperature, mold temperature, mold heat capacity, etc. affect the solidification time for each casting cycle.
[0011]
Setting of the solidification time of this mold is not appropriate, and when the mold is opened in a state where the portion of the design portion is not completely solidified, a sufficient feeder effect cannot be obtained and a nest is generated. If the coagulation time is set to be long in order to avoid the formation of the nest, it is feared that an extra time than the time required for the true coagulation is set and the work efficiency is lowered. If the solidification time is longer than necessary, the heat of the mold received from the molten metal is dissipated and the mold temperature required to cast a good product may change, affecting the quality of the cast product. Furthermore, the setting of the solidification time is not appropriate, and if the temperature for releasing is too high, the cast product may be galled or deformed, and if the temperature for releasing is too low, the release may be difficult.
[0012]
On the other hand, in the method of grasping the solidification state of the molten metal based on the temperature detection by the temperature measuring means provided in the cavity or in the mold, the product specifications such as the product extrusion pin of the mold, the product shape, the mold configuration For example, it is difficult to grasp the solidified state of the casting with high accuracy due to the influence of the heat and heat capacity of the mold itself.
[0013]
Accordingly, an object of the present invention made in view of the above point is to provide a gravity casting method capable of improving the work efficiency by appropriately setting the solidification time regardless of human beings and improving the quality of the cast product. It is in.
[0014]
[Means for Solving the Problems]
The invention of the gravity casting according to claim 1, which achieves the above object, is a method of gravity casting in which molten metal is filled into the cavity of the mold by gravity from the gate and the mold is opened after the solidification time has elapsed. the temperature of the mold is set to the final solidification portion of the filled molten metal temperature measurement points, and ends preset the last to the freezing unit when the coagulation was a temperature at which progressed clotting time, the The solidification arrival time from the start of the solidification time by filling the mold cavity to the end of the solidification time is compared with a preset reference solidification arrival time range, and the solidification arrival time is compared with the reference solidification arrival time. When it is not within the range, it is judged that there is a casting defect .
[0015]
According to the first aspect of the present invention, the temperature set in the final solidification part is hardly affected by uncertain factors such as the atmospheric temperature, mold temperature, mold heat capacity, etc. and has a very high correlation with the solidification state of the molten metal. By ending the solidification time when the temperature at the measurement point reaches a solidification temperature that has been set in advance by experimental or simulation, it is possible to obtain a suitable solidification time that is highly accurate and free from excess or deficiency without human intervention. By setting, it becomes possible to open the mold in an appropriate state, and when the solidification arrival time is not within the reference arrival time range, it is determined that there is a casting defect, thereby improving the quality of the cast product.
[0016]
The invention of gravity casting according to claim 2 is a method of gravity casting in which the molten metal is filled into the mold cavity from the gate by gravity and the mold is opened after the solidification time has elapsed, and the cast product is taken out. The time at which the temperature at the temperature measurement point set in the final solidification part of the molten metal becomes the temperature at which solidification has progressed to the preset final solidification part is the end of the solidification time, and the maximum of the final solidification part Comparing the maximum temperature arrival time from the start of solidification time by filling the mold cavity into the mold cavity to reaching the maximum temperature, and the preset reference maximum temperature range and reference maximum temperature arrival time range When the maximum temperature and the maximum temperature attainment time are not within the reference maximum temperature range or the reference maximum temperature attainment time range, it is determined that there is a casting defect .
[0017]
According to the second aspect of the present invention, the temperature set in the final solidified portion is less affected by uncertain factors such as the atmospheric temperature, mold temperature, mold heat capacity, etc. and has a very high correlation with the solidified state of the molten metal. By ending the solidification time when the temperature at the measurement point reaches a solidification temperature that has been set in advance by experimental or simulation, it is possible to obtain a suitable solidification time that is highly accurate and free from excess or deficiency without human intervention. The mold can be opened in an appropriate state, and the maximum temperature of the final solidification part and the maximum temperature arrival time from the start of the solidification time by filling the mold cavity to the maximum temperature, Comparing the set reference maximum temperature range and the reference maximum temperature arrival time range to calculate the maximum temperature and maximum temperature arrival time The reference maximum temperature range or reference maximum temperature arrival time By determining that there is a casting defects when not囲内, improving the quality of castings can be obtained.
[0018]
According to a third aspect of the present invention, in the gravity casting method according to the first or second aspect , the temperature measurement point is set in a feeder part .
[0019]
According to a third aspect of the present invention, the final solidified portion where the temperature measurement point is set in the first or second aspect is made more concrete, and the feeder portion is formed by a molten metal filled in the cavity from the gate. In order to compensate for the decrease in volume due to the progress of solidification, it serves to supply molten metal, and in order to secure the effect of the molten metal, the molten metal in the molten metal part is set to be the final solidified part that solidifies last .
[0020]
According to a fourth aspect of the present invention, in the gravity casting method of the first or second aspect, the temperature measurement point is set in a runner .
[0021]
According to a fourth aspect of the present invention, the final solidified portion where the temperature measurement point in the first or second aspect is set is made more concrete, and the runner guides the molten metal from the gate into the cavity. Thus, it becomes the final solidified part that solidifies last. In addition, this runway often serves as a feeder.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the gravity casting method according to the present invention will be described with reference to FIGS.
[0031]
FIG. 1 is a conceptual diagram of a gravity casting apparatus 1 in which a support body 4 is tiltably supported on a base 2 by a support shaft 3, and the support body 4 is in a hot water supply / opening position by a tilt drive means (not shown). And tilted between the filling and solidification position. A mold 10 having a lower mold 11 and an upper mold 12 for forming a cavity 13 is attached to the upper side of the support body 4 at the hot water supply / opening position shown in FIG.
[0032]
The upper mold 12 rotates about 90 ° with respect to the lower mold 11 as shown in FIG. 1 and the mold clamping position shown in FIG. 2 via an arm 31 formed in an approximately L shape with respect to the lower mold 11. Then, the mold is clamped by the expansion and contraction operation of the mold clamping cylinder 32 that is supported tiltably between the standing mold opening position and spanned between the arm 31 that is a mold clamping mechanism and the lower portion of the support body 4. It rotates to the position and the mold opening position and is held at those positions.
[0033]
The upper mold 12 is provided with an upper mold product extrusion cylinder 33 for operating an extrusion pin for releasing the cast product protruding into the cavity 13 from the upper mold 12, and the lower mold 11 is provided below the support body 4. A lower product extrusion cylinder 34 is provided which operates an extrusion pin for extruding a cast product protruding into the cavity 13 from the side.
[0034]
A bottomed ladle 36 whose upper side is opened is supported by the support body 4 by a hot water receiving arm 35 that is pivotally supported. Normally, the pouring port 36a of the ladle 36 is held in a state where it is inserted into the pouring gate 17 of the mold 10 to be described later, and the hot water receiving arm 35 can be tilted and accumulated in the ladle 36 as indicated by a virtual line. Maintenance such as hot metal removal work is made easy.
[0035]
Further, the mold 10 is shown in FIG. 3 which is a cross-sectional view of the main part in the filling / solidification position in which the support body 4 is tilted by 90 ° from the hot water supply / opening position shown in FIG. As shown in the I-line cross-sectional view, at the filling / solidification position, the cavity side 11a, 12a is formed above the hollow cavity 13 formed by the cavity side 11a of the lower mold 11 and the cavity side 12a of the upper mold 12. The hot water supply part 16 is continuously formed by the continuous hot water supply part sides 11b and 12b, and further, the pouring gate 17 whose diameter is increased in a taper shape by the hot water supply side 11c and 12c continuous to the hot water supply part sides 11b and 12b and the upper end is opened. It is continuously formed. In the present embodiment, the feeder 16 also serves as a runway for guiding the molten metal supplied from the feeder 17 into the cavity 13, and the feeder 15 and the feeder 17 form a design portion 15.
[0036]
The mold 10 is provided with a temperature detection device 21 in which a temperature measurement point s is set in the feeder part 16. The temperature detection device 21 will be described with reference to FIG. 5 showing an enlarged view of a portion II in FIG.
[0037]
The upper mold 12 is provided with a mounting hole 22 penetrating from the outside to the feeder part 16 and formed by the outer large diameter part 22b and the small diameter part 22c on the feeder part 16 side through the step part 22a. A protection pin 23 for holding a temperature detection means, for example, a thermocouple thermometer 24 using a thermocouple, is attached to the attachment hole 22. The protective pin 23 is fitted to a relatively large diameter base portion 23b and a small diameter portion 22c that are fitted to the large diameter portion 22b via a step portion 23a that can be engaged with the step portion 22a of the mounting hole 22. It is a rod shape having a shaft portion 23c of about 6 mm to 8 mm, and is inserted into the mounting hole 22 from the outside, and the step portion 23a is brought into contact with the step portion 22a of the mounting hole 22 so that the tip of the shaft portion 23c becomes the feeder portion. It has a length that protrudes from the side 12b by about 10 mm to 15 mm into the feeder part 16, and a tip hole thickness in which a holding hole 23d that reaches the vicinity of the tip of the shaft part 23c from the base part 23b is formed is about 2-3 mm. Is formed.
[0038]
A thermocouple thermometer 24 having a temperature measurement point s in contact with the tip of the holding hole 23 d corresponding to the vicinity of the tip of the protection pin 23 is inserted into the holding hole 23 d of the protection pin 23, and the protection pin 23 is attached to the mounting hole 22. By attaching to, the temperature measurement in the hot-water supply part 16 used as the last solidification part is attained.
[0039]
The protective pin 23 with the thermocouple thermometer 24 mounted in the mounting hole 22 is provided with a through hole 25a, and the pin holding plate 25 attached to the upper mold 12 with a mounting bolt (not shown) from the mounting hole 22. The thermocouple thermometer 24 is fixed by a retaining bolt 27 that is screwed into the pin holding plate 25. Further, by installing the thermocouple thermometer 24 in the protective pin 23, the thermocouple thermometer 24 can be disposed without complicating the configuration of the mold 10, and the thermocouple thermometer 24 is protected from molten metal or the like. .
[0040]
In addition, the thermocouple thermometer 24 is installed on the feeder 16 without being affected by the shape or the like of the mold 10, and the installation site can be easily selected according to the product. It can be installed in a state where the influence of the heat and heat capacity is eliminated as much as possible.
[0041]
Here, the molten metal in the feeder 16 serves to supply molten metal filled in the cavity 13 from the gate 17 to compensate for volume reduction during the progress of solidification, and was poured into the cavity 13. The molten metal is set so as to be solidified from the tip, that is, the lower end of the cavity 13 far from the previously poured pouring gate 17, and the molten metal in the feeder 16 becomes the final solidified portion that solidifies last.
[0042]
The temperature at the temperature measuring point s set in the feeder 16 has a very high correlation with the solidified state of the molten metal filled in the cavity 13, and when the molten metal supplied from the pouring gate 17 is filled. Since the solidification time starts, and after reaching the maximum temperature due to the melt heat of the melt poured into the cavity 13, the melt gradually descends with the start of solidification from the lower end that becomes the tip of the cavity 13. The temperature at the time when solidification progresses to 16 and the molten metal solidifies into a casting is lowered to a temperature at which deformation or galling does not occur even if the mold 10 is opened and released, or experimentally or By confirming and setting through simulation, the time when the thermocouple thermometer 24 detects this temperature can be set as the end of the coagulation time.
[0043]
Further, the comparison between the temperature detected by the thermocouple thermometer 24 and the preset temperature and the operation of each part are controlled by the control part, and this action and the like will be described in the casting method described next.
[0044]
A casting method using the gravity casting apparatus 1 configured as described above will be described with reference to a flowchart shown in FIG. 6 and a molten metal temperature in the feeder 16 shown in FIG. 7, that is, a correlation diagram between the feeder temperature and a solidification time.
[0045]
In the state where the support body 4 is held at the hot water supply / die opening position shown in FIG. 1 and the upper die 12 of the mold 10 is held at the clamping position, the molten metal for one casting set in advance in the ladle 36 is obtained. The hot water is supplied (step S1). Subsequently, the support portion body 4 is tilted by 90 ° by the tilt driving means until the gate 17 of the mold 10 is located around the support shaft 3. As the support body 4 is tilted, the mold 10 and the ladle 36 are integrally tilted to the filling / solidifying position (step S2).
[0046]
As the mold 10 and the ladle 36 are tilted to the filling / solidifying position, the molten metal in the ladle 36 flows into the cavity 13 from the pouring port 36a through the pouring port 17 of the mold 10 and is filled ( Step S3). The filling of the molten metal into the cavity 13 is sent to the control unit as the start of the solidification time.
[0047]
As the molten metal is filled, the temperature at the temperature measurement point s disposed in the feeder 16 is increased by the heat of the molten metal poured into the cavity 13 and the feeder 16 as shown in FIG. The temperature detected by the thermocouple thermometer 24 increases.
[0048]
After the temperature at the temperature measurement point s due to the molten metal reaches a maximum temperature A, for example, about 520 ° C. after about 85 seconds from the start of the solidification time, the molten metal filled in the cavity 13 is separated from the feeder 16. Solidification is started from the lower end of the cavity 13, and the temperature at the temperature measurement point s starts to drop along with the solidification.
[0049]
The temperature of this maximum temperature A is detected by the thermocouple thermometer 24, and the temperature at this point is compared with a preset reference maximum temperature range, for example, 510 ° C. to 530 ° C., and the detected temperature is the reference maximum. It is determined whether or not the temperature is within the temperature range (step S4).
[0050]
Here, the reference maximum temperature range is a good casting condition confirmed and set in advance experimentally or by simulation, and a factor that the detected temperature is higher than the reference maximum temperature range is that the molten metal poured into the cavity 13 When the temperature is high, the temperature of the mold 10 is too high, etc. On the other hand, as a factor lower than the reference maximum temperature range, when the amount of the molten metal is insufficient or the molten metal temperature is low, or the temperature of the mold 10 is too low, When the detected temperature is higher or lower than the reference maximum temperature range, there is a concern that casting defects such as nests may occur. Therefore, when the maximum temperature A of the final solidified portion is not within the reference maximum temperature range, it is determined that there is a casting defect.
[0051]
The maximum temperature A detected by the thermocouple thermometer 24 is compared with the maximum temperature at the time of the previous casting, and it is determined whether or not the temperature difference is within a reference temperature difference, for example, within 10 ° C. (step S5). . Here, as a factor in which the temperature difference from the previous time exceeds the reference temperature difference, there may be a case where there is a change in the temperature of the hot water or the mold 10, and there is a concern about the occurrence of casting defects such as nests. When it is not within the reference temperature difference between the temperature detection temperature of the maximum temperature A and the maximum temperature at the previous casting, it is determined that there is a casting defect.
[0052]
Comparing and calculating the maximum temperature arrival time T1 from the solidification start time to the time when the maximum temperature A is reached and an appropriate reference maximum temperature arrival time range that has been experimentally confirmed in advance, for example, 75 seconds to 95 seconds, reaches the maximum temperature. It is determined whether or not the time T1 is within the reference maximum temperature arrival time range (step S6). Here, as a factor that the maximum temperature attainment time T1 is longer than the reference maximum temperature attainment time range, when the molten metal poured into the cavity 13 is insufficient or when the hot water temperature is low, the temperature of the mold 10 is too low. Factors in which the maximum temperature arrival time range is short include cases where the hot water temperature is too high and the temperature of the mold 10 is too high, which may cause casting defects such as formation of nests. Therefore, when the maximum temperature arrival time T1 is not within the reference maximum temperature arrival time range, it is determined that there is a casting defect.
[0053]
After reaching the maximum temperature A, the molten metal filled in the cavity 13 starts to solidify from the lower end farthest from the gate 17, and the temperature at the temperature measurement point s starts to drop as the solidification proceeds.
[0054]
Solidification proceeds to the feeder part 16 (step S7), and a solidified temperature B, for example, 495 ° C. at which the solidified cast product does not cause deformation or galling even when the mold 10 is released. When the thermometer 24 detects, the thermocouple thermometer 24 issues a coagulation time release signal to the control unit as the coagulation time is over. According to this solidification time release signal, the solidification arrival time T2 from the solidification start time to the time when the solidification temperature B is detected is compared with a preset reference solidification arrival time range, for example, 165 to 185 seconds, and the solidification arrival time is the reference. It is determined whether it is within the solidification arrival time range (step S8). Here, the cause of the solidification arrival time being longer than the reference arrival time range is that the temperature of the mold 10 is too high, and the short cause is that the temperature of the mold 10 is too low, etc. There is concern about the occurrence of nests. Therefore, when the solidification arrival time T2 is not within the reference solidification arrival time range, it is determined that there is a casting defect.
[0055]
Subsequently, the support body 4 is tilted by 90 ° around the support shaft 3 by the tilt driving means, and returned to the hot water supply / opening position shown in FIG. 1 (step S9).
[0056]
After returning to the hot water supply / opening position, the mold clamping cylinder 32 is extended, and the upper mold 12 is rotated from the mold clamping position to the mold opening position as shown in FIG. In conjunction with the mold opening operation by the mold clamping cylinder 32, the upper mold product extrusion cylinder 33 provided in the upper mold 12 causes the extrusion pin to protrude into the cavity 13 to promote mold release from the upper mold 12. Further, the extrusion pin is protruded into the cavity 13 by the lower mold product extruding cylinder 34 to promote the release from the lower mold 11 (step S10).
[0057]
Thereafter, the cast product whose mold has been opened is taken out from the mold 10 by a loader or the like (step S11). Here, in step S4, step S5, step S6, and step S8, all of which are determined to be within the set range that has been confirmed experimentally or by simulation in advance are high-quality castings that have no casting defects such as nests. The product is transferred to the next process by a conveyor or the like.
[0058]
On the other hand, what is determined to be negative in any of step S4, step S5, and step S6 may have a casting defect and is solidified to facilitate mold opening because it is in an unsolidified state (step S12). ). In addition, it is feared that there is a casting defect such as a nest in the case determined to be negative in step S8, and these tilt the mold 10 to the hot water supply / opening position (step S13) and open the mold ( Step S14), taken out by a loader or the like and carried out to an NG pallet or the like.
[0059]
Therefore, according to this embodiment, the influence of uncertain factors such as the atmospheric temperature, the mold temperature, the mold heat capacity and the like is extremely small, and the feeder part 16 serving as the final solidification part that is extremely correlated with the solidification state of the molten metal. The temperature measurement point s is set to the maximum temperature A and the maximum temperature arrival time T1 at the temperature measurement point s, and the reference maximum temperature range and the reference maximum temperature arrival time range set in advance are compared and calculated. By determining whether the temperature arrival time T1 is within the reference temperature maximum range or the reference maximum temperature arrival time range, the solidification arrival time T2 from the start of the solidification time to the end of the solidification time, and a preset reference A casting defect can be detected by comparing the solidification arrival time range and determining whether the solidification arrival time T2 is within the reference arrival time range. Therefore, the solidification time without excess or deficiency is set without human intervention, ensuring the quality of the cast product and improving the work efficiency.
[0060]
Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, the gravity casting apparatus in which the mold 10 is tilted has been described. However, the gravity casting apparatus in which the mold is not tilted, and the runner for guiding the molten metal from the gate to the cavity and the feeder section are independent of each other. It can also be applied to a gravity casting apparatus. In addition, in a gravity casting apparatus in which the runner and the feeder section are independent, the temperature measurement point s can be set in the runner or feeder section that becomes the final solidification part.
[0061]
Furthermore, it is possible to form a cooling water passage in the mold according to the shape and thickness of the cast product, and to control the solidification rate in the cavity by the cooling water. In addition to casting an aluminum alloy, casting of a high melting point alloy such as copper or iron is also possible.
[0062]
【The invention's effect】
According to the gravity casting method of the present invention described above, the molten metal poured into the cavity from the pouring gate is hardly affected by the temperature of the mold or the like where the molten metal finally solidifies, and the solidified state of the molten metal is extremely high. Appropriate solidification without excess or deficiency without human intervention by ending the solidification time when the temperature of the final solidification zone that has correlation reaches the solidification temperature that has been set by experimental confirmation or simulation. When the time is set and the solidification arrival time is not within the reference arrival time range, it is determined that there is a casting defect, or when the maximum temperature and the maximum temperature arrival time are not within the reference maximum temperature range or the reference maximum temperature arrival time range By determining that there is a casting defect , the quality of the cast product can be ensured and the working efficiency is improved.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a gravity casting apparatus showing an outline of an embodiment according to the present invention.
FIG. 2 is a side view of a main part of a gravity casting apparatus showing a mold open state.
FIG. 3 is a cross-sectional view of a main part of a mold.
4 is a cross-sectional view taken along the line II of FIG.
FIG. 5 is an enlarged view of a portion II in FIG. 3;
FIG. 6 is an operation flowchart of the gravity casting apparatus.
FIG. 7 is a correlation diagram between a feeder temperature and a solidification time.
FIG. 8 is a correlation diagram between mold temperature and solidification time.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gravity casting apparatus 10 Mold 11 Lower mold 12 Upper mold 13 Cavity 15 Design part 16 Hot water supply part (runner)
17 Gate 21 Temperature detection device 23 Protection pin 24 Thermocouple thermometer (temperature detection means)
s Temperature measurement point

Claims (4)

In the gravity casting method, the molten metal is filled from the gate into the mold cavity by gravity, and the mold is opened after the solidification time has elapsed.
While the temperature at the temperature measurement point set in the final solidification part of the molten metal filled in the mold becomes the temperature when solidification has progressed to the preset final solidification part, the solidification time ends ,
The solidification arrival time from the start of the solidification time to the end of the solidification time by filling the molten metal into the cavity of the mold is compared with a preset reference solidification arrival time range, and the solidification arrival time is the reference solidification arrival time. Gravity casting characterized by determining that there is a casting defect when not within the time range . In the gravity casting method, the molten metal is filled from the gate into the mold cavity by gravity, and the mold is opened after the solidification time has elapsed.
While the temperature at the temperature measurement point set in the final solidification part of the molten metal filled in the mold becomes the temperature when solidification has progressed to the preset final solidification part, the solidification time ends ,
Maximum temperature of the final solidification part and the maximum temperature arrival time from the start of solidification time by filling the mold cavity to the maximum temperature, and the preset reference maximum temperature range and reference maximum temperature arrival time A gravity casting method characterized by determining that there is a casting defect when the maximum temperature and the maximum temperature arrival time are not within the reference maximum temperature range or the reference maximum temperature arrival time range by comparing and calculating a range . The gravity casting method according to claim 1 or 2 , wherein the temperature measurement point is set in a feeder part. The temperature measurement point, the gravity casting method according to claim 1 or 2, characterized in that set in the hot water canal.

Images