JP2004195533A - Method for controlling cooling of metallic mold in low-pressure casting apparatus, and metallic mold in low-pressure casting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for low-pressure casting and a metallic mold in the low-pressure casting apparatus with which the improvements of quality in a cast product and productivity due to shortening of the casting cycle can be expected. <P>SOLUTION: The method for controlling the cooling of the metallic mold in this low-pressure casting apparatus, is provided with a thermo-couple 54 for detecting molten metal temperature at a sprue 45, an upper mold cooling water passage 55 formed in an upper mold 41, a lower mold cooling water passage 59 formed in a lower mold 43, a side mold cooling water passage 58 formed in a side mold 42, an ignition plug insert cooling water passage 56 formed in an ignition plug insert 52 and a lifter insert cooling water passage 57 formed in a lifter insert 53, continued through an upper mold cooling water control valve 63, a lower mold cooling water control valve 75, a side mold cooling water control valve 72, an ignition plug insert cooling water control valve 66 and a lifter insert cooling water control valve 69 in a cooling water supplying source 61, respectively. Then, in this metallic mold cooling control method, the respective cooling water control valves 63, 75, 72, 66, 69 are controlled based on the variation of the measured temperature with the thermo-couple 54. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mold cooling control method for a low-pressure casting apparatus and a mold for a low-pressure casting apparatus.
[0002]
[Prior art]
For example, in the casting of aluminum alloys and the like, mass production is possible, the solidification process is rational, dense and dimensional accuracy is good, and the equipment cost is relatively low, so the low pressure casting method is widely used. I have.
[0003]
In the low-pressure casting method, a molten metal is placed in a closed molten metal tank, compressed air is supplied into the molten metal tank to pressurize the molten metal surface, the molten metal is pushed up through a stalk by the applied pressure, and the metal placed on the molten metal is placed on the molten metal. After casting the molten metal supplied into the mold cavity and holding the molten metal in the cavity for a certain period of time while maintaining the pressurized state, it is cooled while releasing the pressure, and when the molten metal solidifies, the mold is opened and the casting is carried out. Is the way.
[0004]
By automatically setting the pressurization time and cooling time during low-pressure casting, the solidification state of the molten metal is stabilized, and a pressure control method for a low-pressure casting device that aims to improve productivity and stabilize quality is proposed. (For example, see Patent Document 1).
[0005]
The pressurization control method of the low-pressure casting device will be described with reference to a schematic system diagram shown in FIG.
[0006]
The low-pressure casting apparatus 101 includes a die base 105 on which an upper mold 102a, a horizontal mold 102b forming a cavity 103 together with the upper mold 102a, and a lower mold 102c having a gate 104 are installed. A mold clamping device 106 for clamping the mold 102 installed in the mold, a molten metal tank 107 installed below the die base 105, and a stalk 108 penetrating through the die base 105 and hanging into the molten metal tank 107, and a stalk 108. A first temperature sensor 109a for detecting the temperature of the molten metal is installed in the lower mold 102c, a second temperature sensor 109b for detecting the temperature of the gate 104 is installed in the lower mold 102c, and a third temperature sensor 109c is installed in the horizontal mold 102b.
[0007]
Then, the pressurizing time and the cooling time are automatically determined by a map or the like which is previously confirmed by experiments or simulations according to the detected temperatures of the first, second, and third temperature sensors 109a, 109b, and 109c during casting. It is intended to stabilize the solidification state of the molten metal by setting it appropriately.
[0008]
Further, a temperature detecting means is provided in each part of the mold and a cooling water passage is formed, and cooling water is supplied to each cooling water passage based on the detected temperature of each temperature detecting means to control the temperature of each part of the mold. There is a mold cooling control method to be performed.
[0009]
This mold cooling control method will be described with reference to FIGS. 9 and 10 by taking as an example a case where a cylinder head of an engine is cast.
[0010]
FIG. 9 is a configuration diagram of a mold 110 for low-pressure casting. The mold 110 has an upper mold 111, a pair of horizontal molds 112, and a lower mold 113, and includes an upper mold 111, a horizontal mold 112, A hollow cavity 114 is formed by the cavity sides 111a, 112a, 113a of the lower mold 113.
[0011]
The lower mold 113 is provided with a sprue 115 extending in the up-down direction and communicating between a stalk side (not shown) and the cavity 114 side.
[0012]
The upper die 111 is provided with a punched pin mounting hole 117, a spark plug nesting mounting hole 118, and a lifter nesting mounting hole 119 which are formed to penetrate in the vertical direction.
[0013]
A cast pin 121, a spark plug insert 122, and a lifter insert 123 are fitted and attached to the cast pin mounting hole 117, the spark plug insert mounting hole 118, and the lifter insert insert hole 119, respectively.
[0014]
The cast pin 121 has a column shape in which the base 121 a is fitted and mounted in the cast pin mounting hole 117, and the tip 121 b penetrates through the cavity 114 and reaches the upper part of the gate 115 of the lower mold 113.
[0015]
The ignition plug nest 122 has a base 122a fitted and fitted in the ignition plug nest mounting hole 118 of the upper die 111, and has a columnar shape with a tip 122b protruding into the cavity 114. It is a nest that forms a hole. The lifter nest 123 has a columnar shape in which the base 123a is mounted in the lifter nest mounting hole 119 and the tip 123b protrudes into the cavity 114, and forms a valve lifter mounting hole for mounting the valve lifter on the cylinder head.
[0016]
A thermocouple thermometer 131 in which a temperature measurement point 131a is set corresponding to the vicinity of the cavity 114 is provided in the upper mold 111, and a cooling water inlet 132a is formed at an end thereof, and the thermocouple thermometer 131 is folded near the cavity 114. An upper cooling water passage 132 having a cooling water outlet 132b formed near the cooling water inlet 132a.
[0017]
In the spark plug insert 122, a thermocouple thermometer 133 in which a temperature measurement point 133a is set corresponding to the vicinity of the tip 122b is provided, and a cooling water inlet 134a is formed in the base 122a so that the vicinity of the tip 122b is formed. An ignition plug nested cooling water passage 134 is formed by turning the cooling water outlet 134b and forming the cooling water outlet 134b in the base 122a.
[0018]
The lifter insert 123 has a thermocouple thermometer 135 in which a temperature measuring point 135a is set, and a cooling water inlet 136a is formed in the base 123a, and the cooling water outlet 136b is folded near the tip 123b. A lifter nested cooling water passage 136 formed in the base 123a is formed.
[0019]
The horizontal mold 112 is provided with a thermocouple thermometer 137 in which a temperature measuring point 137a is set corresponding to the vicinity of the cavity 114, and a cooling water inlet 138a is formed at an end thereof. A horizontal cooling water passage 138 having a cooling water outlet 138b formed at an end thereof is provided.
[0020]
The lower mold 113 is provided with a thermocouple thermometer 139 in which a temperature measuring point 139a is set corresponding to the vicinity of the sprue 115, and a cooling water inlet 140a is formed at an end thereof. A lower cooling water passage 140 having a cooling water outlet 140b formed near the cooling water inlet 140a is formed.
[0021]
FIG. 10 shows cooling for supplying cooling water to each of the upper cooling water passage 132, the spark plug nested cooling water passage 134, the lifter nested cooling water passage 136, the horizontal cooling water passage 138, and the lower cooling water passage 140. It is a water control diagram.
[0022]
The cooling water supply source 141 is provided by an upper cooling water control valve 143, an ignition plug nested cooling water control valve 146, a lifter nested cooling water control valve 149, a horizontal cooling water control valve 152, and a lower cooling water control valve 155. Each cooling of the upper cooling water passage 132, the spark plug nesting cooling water passage 134, the lifter nesting cooling water passage 136, the horizontal cooling water passage 138, and the lower cooling water passage 140 via the passages 142, 145, 148, 151, 154. Water inlets 132a, 134a, 136a, 138a, 140a are connected.
[0023]
The upper mold cooling water control valve 143 is controlled to be opened and closed by an upper mold temperature controller 144, and a detected value from a thermocouple thermometer 131 is input to the upper mold temperature controller 144 at the time of casting, and the upper mold temperature controller 144 uses the detected value based on the detected value. The upper mold cooling water control valve 143 is opened to supply cooling water to the upper mold cooling water passage 132 to cool the upper mold 111.
[0024]
The ignition plug nest cooling water control valve 146 is controlled to open and close by an ignition plug nest temperature controller 147, and a detected value from a thermocouple thermometer 133 is input to the ignition plug nest temperature controller 147 during casting, and the ignition plug nest temperature controller 147 Based on the detected value, the spark plug nest cooling water control valve 146 is opened to supply cooling water to the spark plug nest cooling water passage 134 to cool the spark plug nest 122.
[0025]
The lifter nest cooling water control valve 149 is controlled to be opened and closed by a lifter nest temperature controller 150, and a detected value from a thermocouple thermometer 135 is input to the lifter nest temperature controller 150 during casting, and the lifter nest temperature controller 150 is based on the detected value. The lifter nest cooling water control valve 149 is opened to supply cooling water to the lifter nest cooling water passage 136 to cool the lifter nest 123.
[0026]
The horizontal cooling water control valve 152 is controlled to be opened and closed by a horizontal temperature controller 153, and a detection value from a thermocouple thermometer 137 is input to the horizontal temperature controller 153 during casting, and the horizontal temperature controller 153 determines the horizontal cooling water based on the detected value. The control valve 152 is opened to supply the cooling water to the horizontal cooling water passage 138 to cool the horizontal molding 112.
[0027]
The lower mold cooling water control valve 155 is controlled to be opened and closed by a lower mold temperature controller 156, and a detected value from a thermocouple thermometer 139 is input to the lower mold temperature controller 156 during casting, and the lower mold temperature controller 156 uses the detected value based on the detected value. The lower mold water control valve 155 is opened to supply cooling water to the lower mold water passage 140 to cool the lower mold 113.
[0028]
Then, the cooling temperature of each part where no cavities are formed inside the casting is confirmed and set in advance by experiment or simulation, and the temperature is controlled by each of the temperature controllers 144, 147, 150, 153, and 156 so as to reach the set temperature. The mold cooling control valve 143, the spark plug nested cooling water control valve 146, the lifter nested cooling water control valve 149, the horizontal cooling water control valve 152, and the lower mold cooling water control valve 155 are opened and closed to control the upper mold 111 and the ignition plug nest 122. Then, the lifter insert 123, the horizontal mold 112, and the lower mold 113 are cooled.
[0029]
[Patent Document 1]
JP-A-6-114535
[0030]
[Problems to be solved by the invention]
According to the pressurization control method of Patent Document 1 shown in FIG. 8, the first temperature sensor 109a provided on the stalk 108, the second temperature sensor 109b provided on the lower mold 102c, and the third temperature sensor 109c provided on the horizontal mold 102b. The pressurizing time and the cooling time are determined based on the detected molten metal temperature, the gate temperature, and the temperature of the horizontal mold 102b in advance by a map or the like which is set by confirming experimentally or by simulation in advance. Pressurization control corresponding to a change in temperature is performed.
[0031]
However, it is difficult to appropriately control the temperature of each part including the nests in the molds, for example, the upper mold, the lower mold, the horizontal mold, and the mold having various nests. Since it is not possible to follow the directional solidification temperature gradient in the casting cycle, there is a concern about occurrence of casting defects such as formation of cavities in thick portions of the cast product where the thickness changes greatly.
[0032]
In addition, since the first, second, and third temperature sensors 109a, 109b, and 109c are provided in the stalk 108, the lower mold 102c, and the horizontal mold 102b, respectively, the mold 102 is complicated and the accuracy of each temperature sensor is reduced. And the occurrence of defects such as poor insulation of the compensating lead wire, which is a factor of causing a deterioration in the quality of the cast product. Many maintenance man-hours are required to prevent these problems from occurring.
[0033]
On the other hand, according to the cooling control method shown in FIGS. 9 and 10, the thermocouple thermometers 131 and 137 are respectively provided in the upper mold 111, the horizontal mold 112, the lower mold 113, the spark plug insert 122, and the lifter insert 123 forming the mold 110. , 139, 133, 135 and the respective cooling water passages 132, 138, 140, 134, 136, and the cooling temperature of each portion where no nests are formed inside the casting is previously confirmed experimentally or by simulation, and the temperature is determined. Thus, the cooling water can be supplied to each of the cooling water passages 132, 138, 140, 134, and 136 to control the temperature of each part of the mold.
[0034]
However, these temperature controls cannot strictly follow the directional solidification temperature gradient that differs in each casting cycle, and nests are generated particularly in a thick portion where the thickness changes greatly in a casting having a complicated shape. There is a concern that casting defects may occur.
[0035]
In addition, thermocouple thermometers 131, 137, 139, 133, and 135 for detecting temperatures are provided in the upper mold 111, the horizontal mold 112, the lower mold 113, the spark plug insert 122, and the lifter insert 123 forming the mold 110, respectively. Accordingly, the mold is complicated, and there are many factors that cause problems such as a decrease in accuracy of the thermocouple thermometers 131, 137, 139, 133, and 135, and a failure in insulation of the compensating lead wires, and a decrease in quality of the cast product. It becomes a factor. Many maintenance man-hours are required to prevent these problems from occurring.
[0036]
Accordingly, an object of the present invention in view of such a point is that an ideal mold cooling can be obtained by a temperature detected by a single temperature detecting means, and the quality of a cast product is improved, and the productivity is improved by shortening a casting cycle. It is an object of the present invention to provide a mold cooling control method for a low-pressure casting apparatus and a mold for a low-pressure casting apparatus that can be expected.
[0037]
[Means for Solving the Problems]
The invention of a mold cooling control method for a low-pressure casting apparatus according to claim 1, which achieves the above object, is a mold having a stalk extending in the vertical direction and a continuous cavity formed at the upper end of the stalk via a sprue. A mold cooling control method for a low-pressure casting apparatus for filling and casting a molten metal into the cavity via the stalk, wherein a temperature of the molten metal at the gate is detected, and the metal is cooled in accordance with the detected temperature. The cooling means provided in each part of the mold is controlled.
[0038]
The invention of claim 1 focuses on the fact that the temperature of the molten metal at the gate, which becomes the final solidified portion of the molten metal filled in the cavity and changes at each casting cycle, corresponds to the temperature change at each part of the mold. The control timing of the cooling means at which the cooling temperature at which directional solidification can be obtained in each part of the mold corresponding to the change in the molten metal temperature in the gate portion is confirmed and set in advance experimentally or by simulation, By controlling the cooling means provided in each part of the mold based on the change in the temperature of the molten metal at the gate, it is possible to promote the solidification rate while achieving directional solidification, and ideal mold cooling is achieved. As a result, it is expected that the quality of the cast product is improved and the productivity is improved by shortening the casting cycle.
[0039]
According to a second aspect of the present invention, there is provided a mold cooling control method for a low-pressure casting apparatus, comprising: a mold having a cavity formed by a plurality of mold components; A method of controlling cooling of a mold of a low-pressure casting apparatus, comprising: a stalk continuous with a cavity through a formed gate, and filling and casting a molten metal into the cavity through the stalk. Temperature detecting means for detecting a temperature, and cooling water passages formed in each of the mold components connected to the cooling water supply source via each cooling water control valve, and the temperature detected by the temperature detecting means The cooling water control valves are controlled to open and close in response to supply cooling water from a cooling water supply source to the respective cooling water passages.
[0040]
According to the second aspect of the present invention, the timing of supplying cooling water to each cooling water passage by each cooling water control valve at which a cooling temperature at which directional solidification can be obtained in each mold member of the mold corresponding to a change in the temperature of the molten metal at the gate. Is set beforehand experimentally or by simulation, and the respective cooling water control valves are controlled to open and close according to the temperature detected by the temperature detecting means at the gate to supply cooling water to the respective cooling water passages. By gradually cooling the lower mold and each mold member, it is possible to promote the solidification rate while aiming for directional solidification, and to achieve ideal mold cooling, to improve the quality of the cast product and Productivity can be improved by shortening the casting cycle.
[0041]
Further, since each cooling water control valve is controlled to open and close based on the detection of the molten metal temperature at the gate portion by a single temperature detecting means, the cooling control is simplified and causes of troubles are reduced, and the quality of the cast product is reduced. Can be avoided.
[0042]
According to a third aspect of the present invention, there is provided a mold for a low-pressure casting apparatus, wherein a cavity is formed by a plurality of mold components, and the upper end of the mold extends in the up-down direction. A stalk continuous with the cavity through a sprue formed in the member, and a mold of a low-pressure casting device for filling and casting a molten metal into the cavity through the stalk, the temperature of the molten metal at the sprue portion And a cooling unit formed in each of the mold components connected to the cooling water supply source through each of the cooling water control valves that are respectively opened and closed according to the temperature detected by the temperature detecting unit. And a water passage.
[0043]
According to the third aspect of the present invention, the timing of supplying the cooling water to the respective cooling water passages by the cooling water control valve which becomes the cooling temperature at which the directional solidification can be obtained in each mold member of the mold corresponding to the change of the molten metal temperature at the gate. Is set in advance by experiment or by simulation, and each cooling water control valve is controlled based on the temperature detected by the temperature detecting means to supply cooling water to the respective cooling water passages so that each mold component is Cooling allows the solidification rate to be accelerated while achieving directional solidification, resulting in ideal mold cooling, and expected to improve the quality of castings and improve productivity by shortening the casting cycle. it can.
[0044]
Furthermore, since each cooling water control valve is controlled based on the temperature measured by the single temperature detecting means, it is not necessary to arrange the temperature detecting means in each mold constituent member, and simplification of the mold can be achieved. In addition to the above, factors that cause problems such as a decrease in accuracy of the temperature detecting means and an insulation failure of the compensating lead wire are extremely reduced, a decrease in quality of the cast product can be avoided, and maintenance can be simplified.
[0045]
According to a fourth aspect of the present invention, there is provided a mold for a low pressure casting apparatus, wherein a cavity is formed by an upper mold, a lower mold having a gate, and a horizontal mold disposed between the lower mold and the upper mold. A mold having a mold and a stalk extending vertically and having an upper end connected to the cavity via the gate, and filling the cavity with the molten metal through the stalk to perform casting; In the above, the upper mold connected to the cooling water supply source via a temperature detecting means for detecting the temperature of the molten metal in the gate section, and an upper cooling water control valve which is opened and closed according to the temperature detected by the temperature detecting means. Lower mold cooling formed in the lower mold connected to the cooling water supply source through the formed upper mold water passage and the lower mold water control valve that is opened and closed according to the temperature detected by the temperature detecting means. The water passage and the temperature detection means To characterized in that a horizontal cooling water passage formed in the horizontal continuous to the cooling water supply source through a horizontal cooling water control valve which is opened and closed controlled according to the temperature.
[0046]
According to the invention of claim 4, the upper cooling control valve and the horizontal cooling water control valve which have the cooling temperatures at which the directional solidification can be obtained in the upper mold, the horizontal mold and the lower mold corresponding to the change in the molten metal temperature at the gate. The cooling water supply timing to the upper cooling water passage, the horizontal cooling water passage, and the lower cooling water passage by the lower cooling water control valve is set beforehand experimentally or by simulation and set. Cools the upper, horizontal, and lower molds by controlling the upper, horizontal, and lower cooling water control valves based on the change, thereby accelerating the solidification rate while achieving directional solidification. It is possible to achieve ideal mold cooling, and it is expected that the quality of cast products is improved and the productivity is improved by shortening the casting cycle.
[0047]
Further, since the upper cooling water control valve, the horizontal cooling water control valve, and the lower cooling water control valve are controlled based on the temperature detected by the single temperature detecting means, each part of the upper, horizontal, and lower molds is controlled. In addition, it is not necessary to dispose the temperature detecting means, which simplifies the mold, and reduces the accuracy of the temperature detecting means and the occurrence of problems such as insulation failure of the compensating lead wire. And maintenance can be simplified.
[0048]
According to a fifth aspect of the present invention, in the mold for the low pressure casting apparatus according to the fourth aspect, the mold has a nest, and a nested cooling water control valve that is controlled to open and close according to the temperature detected by the temperature detecting means. A nested cooling water passage formed in the nest connected to the cooling water supply source through the nest.
[0049]
According to the fifth aspect of the present invention, in addition to the fourth aspect, cooling to the nested cooling water passage by the nested cooling water control valve which has a cooling temperature at which directional solidification in the nest corresponding to the temperature change of the molten metal at the gate is obtained. The water supply timing is set beforehand experimentally or by simulation, and the nest cooling water control valve is controlled based on the temperature detected by the temperature detecting means to supply cooling water to the nest cooling water passage to cool the nest. By doing so, it is possible to accelerate the solidification speed while achieving directional solidification even in a mold having a nest, and it is expected that the quality of a cast product will be improved.
[0050]
According to a sixth aspect of the present invention, in the mold for a low-temperature casting apparatus according to any one of the third to fifth aspects, the mold has a cast pin whose tip projects into the gate, and the temperature detecting means is provided. Is a thermocouple thermometer provided on the cast pin and having a temperature measuring point near the tip of the cast pin.
[0051]
According to the invention of claim 6, the thermocouple thermometer is provided on the cast pin whose tip projects into the gate so that the thermocouple thermometer as the temperature detecting means is provided without complicating the configuration of the mold. can do.
[0052]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the mold cooling control method of the low-pressure casting apparatus and the mold of the low-pressure casting apparatus according to the present invention will be described with reference to FIGS. Will be explained.
[0053]
FIG. 1 is a conceptual diagram of a low-pressure casting apparatus 1 including a holding furnace 10 and a casting machine 30, FIG. 2 is a schematic diagram of a main part of the low-pressure casting apparatus 1, and FIG. FIG.
[0054]
The holding furnace 10 has a molten metal tank 12 supported by a molten metal holding furnace 11 and holding a molten metal 80, and a molten metal supply device 15 is suspended and supported by a support frame 13 provided above the molten metal tank 12.
[0055]
As shown in FIG. 2, the molten metal supply device 15 is a bottomed cylinder immersed in a molten metal 80 of an aluminum alloy whose upper end is hermetically supported by a base 16 suspended and supported and whose lower part is stored in the molten metal bath 12. A pressurized pot 17 is provided.
[0056]
At the bottom of the pressure pot 17, a suction port 17a communicating with the inside of the molten metal tank 12 is formed. At the side of the pressure pot 17, the base end of a hot water supply pipe 19 whose leading end communicates with the stalk 33 of the casting machine 30 via the base 16 is inserted, and a discharge port 19a formed in the hot water supply pipe 19 is added. It is open in the pressure pot 17. The suction port 17a and the discharge port 19a are opened and closed by a suction port side valve element 18 and a discharge port side valve element 20 provided in the pressure pot 17, respectively.
[0057]
Further, a vacuum pump 22 for depressurizing the inside of the pressurizing pot 17 and a pressurized gas body, in this embodiment, compressed air, are fed into the pressurizing pot 17 through the suction and air supply pipe 21 to the melt supply device 15. A pressurizing pot decompressing and pressurizing means 24 constituted by a pressurizing pump 23 and the like for pressurizing is provided. A level sensor (not shown) for detecting the liquid level of the molten metal 80 is provided in the pressurizing pot 17. In addition, each operation control of these suction port side valve element 18, discharge port side valve element 20, vacuum pump 22, pressurizing pump 23, etc. is performed by a control unit (not shown).
[0058]
On the other hand, the casting machine 30 has a cylindrical stalk 33 having an upper end attached to a die base 31 via a stalk plate 32 and extending vertically, and a hot water supply pipe led to the lower end of the stalk 33 from the holding furnace 10. A die 40 for casting a cylinder head is mounted on a die base 31 to which the distal end of the die 19 is connected.
[0059]
As shown in FIG. 3, the mold 40 has an upper mold 41, a pair of horizontal molds 42, and a lower mold 43, which are mold constituent members, and a mold clamping device 35 constituted by a hydraulic cylinder or the like (see FIG. 1). The upper die 41 is moved up and down so as to be able to contact and separate from the lower die 43 coupled to the die base 31, and the pair of horizontal dies 42 are moved in the horizontal direction so as to contact and separate from each other. And the cavity side 41a, 42a, 43a of the lower mold 43 forms a hollow cavity 44.
[0060]
The upper die 41 is provided with a punching pin mounting hole 47 that penetrates in the vertical direction and is formed by an upper large diameter portion 47a and a lower small diameter portion 47b via a step portion. , A spark plug insert mounting hole 48 formed by an upper large diameter portion 48a and a lower small diameter portion 48b, and a lifter insert formed by an upper large diameter portion 49a and a lower small diameter portion 49b through a step portion. A mounting hole 49 is formed. The upper die 41 has an upper cooling water passage 55 having a cooling water inlet 55a formed at an end thereof and being folded near the cavity 44 to form a cooling water outlet 55b near the cooling water inlet 55a. Has been established.
[0061]
In the cast pin mounting hole 47, the spark plug insert mounting hole 48, and the lifter insert mounting hole 49, a die forming component 51, a spark plug insert 52, and a lifter insert 53 are fitted to the upper die 41. It is attached.
[0062]
The blanking pin 51 is a rod having a relatively large-diameter base portion 51a fitted into the large-diameter portion 47a of the blanking pin mounting hole 47 and a shaft portion 51b fitted into the small-diameter portion 47b. The tip 51c has a length reaching the upper part of the gate 45 of the lower mold 43 through the cavity 44, and is held at a predetermined position by fitting the base 51a into the cast pin mounting hole 47.
[0063]
A thermocouple thermometer 54, which is a temperature detecting means in which a temperature measurement point a is set corresponding to the vicinity of the tip 51c, is provided inside the cast pin 51, and the cast pin 51 is inserted into the cast pin mounting hole 47. By mounting, the temperature of the upper part in the gate 45 can be detected. Further, by installing the thermocouple thermometer 54, the thermocouple thermometer 54 can be provided without complicating the mold 40.
[0064]
The spark plug insert 52 has a rod-like shape having a relatively large-diameter base portion 52a fitted into the large-diameter portion 48a of the spark plug mounting hole 48 and a shaft portion 52b fitted into the small-diameter portion 48b. It has a length protruding inward, and is held at a predetermined position by fitting the base 52a into the spark plug nest mounting hole 48. Further, in the spark plug insert 52, a cooling water inlet 56a is formed in the base 52a, and an ignition plug insert cooling water passage 56 is formed in which the cooling water outlet 56b is formed in the base 52a by being folded near the tip 52c. ing.
[0065]
The lifter insert 53 has a rod shape having a relatively large-diameter base 53a fitted to the large-diameter portion 49a of the lifter insert mounting hole 49 and a shaft 53b fitted to the small-diameter portion 49b. And is held at a predetermined position by fitting the base 53a into the lifter nesting hole 49. Further, the lifter insert 53 has a lifter insert cooling water passage 57 in which a cooling water inlet 57a is formed in the base 53a and turned around near the tip 53c to form a cooling water outlet 57b in the base 57a. .
[0066]
The horizontal die 42 is provided with a horizontal cooling water passage 58 having a cooling water inlet 58a formed at an end thereof and being folded near the cavity 44 to form a cooling water outlet 58b at the end.
[0067]
The lower die 43 is formed with a spout 45 extending vertically to communicate the stalk 33 side and the cavity 44 side, and to have a relatively small opening area in the middle portion and gradually increasing upward and downward, Further, a lower cooling water passage 59 is formed in which a cooling water inlet 59a is formed at an end and is folded near the gate 45 to form a cooling water outlet 59b near the cooling water inlet 59a.
[0068]
FIG. 4 shows the cooling water passages of the upper cooling water passage 55, the spark plug nested cooling water passage 56, the lifter nested cooling water passage 57, the horizontal cooling water passage 58, and the lower cooling water passage 59 which are the cooling means. FIG. 50 is a cooling water control circuit diagram 50 for supplying water.
[0069]
In FIG. 4, reference numeral 61 denotes a cooling water supply source, which is branched from the cooling water supply source 61 and is provided with a cooling water inlet of an upper cooling water passage 55 through a supply passage 62 in which an upper cooling water control valve 63 is interposed. 55a, through a supply path 65 in which a spark plug nested cooling water control valve 66 is interposed, and through a supply path 68 in which a lifter nested cooling water control valve 69 is interposed into a cooling water inlet 56a of the ignition plug nested cooling water passage 56. A lower cooling water control valve 75 is interposed at a cooling water inlet 58a of the horizontal cooling water passage 58 via a supply passage 71 having a horizontal cooling water control valve 72 interposed at a cooling water inlet 57a of the lifter nested cooling water passage 57. The cooling water inlet 59 a of the lower cooling water passage 59 is connected via a supply path 74.
[0070]
The upper mold cooling water control valve 63 is controlled to be opened and closed by an upper mold temperature controller 64, and the temperature detected by the thermocouple thermometer 54 is input to the upper mold temperature controller 64 at the time of casting, and the upper mold temperature controller 64 determines the temperature based on the detected temperature. The upper mold cooling water control valve 63 is opened to supply cooling water to the upper mold cooling water passage 55 to cool the upper mold 41.
[0071]
The ignition plug nest cooling water control valve 66 is controlled to be opened and closed by an ignition plug nest temperature controller 67, and a detected value from the thermocouple thermometer 54 is input to the ignition plug nest temperature controller 67 during casting, and the ignition plug nest temperature controller 67 The ignition plug nest cooling water control valve 66 is opened based on the detected value to supply cooling water to the ignition plug nest cooling water passage 56 to cool the ignition plug nest 52.
[0072]
The lifter nesting cooling water control valve 69 is controlled to be opened and closed by a lifter nesting temperature controller 70, and a detected value from the thermocouple thermometer 54 is input to the lifter nesting temperature controller 70 during casting, and the lifter nesting temperature controller 70 is based on the detected value. The lifter nest cooling water control valve 69 is opened to supply cooling water to the lifter nest cooling water passage 57 to cool the lifter nest 53.
[0073]
The horizontal cooling water control valve 72 is controlled to be opened and closed by a horizontal temperature controller 73, and a detected value from the thermocouple thermometer 54 is input to the horizontal temperature controller 73 during casting, and the horizontal temperature controller 73 performs horizontal cooling water control based on the detected value. The control valve 72 is opened to supply cooling water to the horizontal cooling water passage 58 to cool the horizontal molding 42.
[0074]
The lower mold cooling water control valve 75 is controlled to be opened and closed by a lower mold temperature controller 76, and a detected value from the thermocouple thermometer 54 is input to the lower mold temperature controller 76 at the time of casting, and the lower mold temperature controller 76 performs an operation based on the detected value. The lower mold water control valve 75 is opened to supply cooling water to the lower mold water passage 59 to cool the lower mold 43.
[0075]
Then, when performing cooling, care is taken so that solidification is performed from the upper part of the cavity 44 farthest from the gate 45 into which the molten metal 80 has been poured first, so that directional solidification is performed and finally the gate 45 is solidified. Control cooling.
[0076]
Here, the temperature measurement point a detected by the thermocouple thermometer 54 is a position that becomes the final solidification portion of the molten metal filled in the cavity 44 at the molten metal temperature of the gate 45, and the temperature of the temperature measurement point a is As shown in FIG. 5, the temperature at the tip of the core pin changes with each casting cycle. This temperature change corresponds to the temperature change of each part of the mold 40, that is, the upper mold 41, the horizontal mold 42, the lower mold 43, the spark plug insert 52, and the lifter insert 53, and is a temperature representative of the directional solidification of casting.
[0077]
Since the temperature of the temperature measuring point a rises as the molten surface 80a of the molten metal 80 in the Stoke 33 rises and approaches the temperature measuring point a, the temperature of the temperature measuring point a on the molten surface 80a at a predetermined position is determined. The position of the molten metal surface 80a in the Stoke 33 can be detected by performing experiments or simulations in advance, and the thermocouple thermometer 54 functions as a molten metal surface position sensor, and the molten metal surface detected by the thermocouple thermometer 54 is used. The detection signal is sent to a control unit provided in the molten metal supply device 15.
[0078]
Further, the temperature at the temperature measurement point a gradually increases due to the heat of fusion of the molten metal 80 poured into the cavity 44 from the gate 45, and after reaching the maximum value, the temperature of the molten metal 80 from the gate 45 where the molten metal 80 was poured first. Since solidification is performed from the farthest upper end and gradually descends, the start of cooling with cooling water is confirmed experimentally or in advance in advance so as to prevent cavities from occurring inside the casting at the temperature of the temperature measurement point a. The upper mold cooling water control valve 63, the spark plug nested cooling water control valve 66, and the cooling start signal from each of the temperature controllers 64, 67, 70, 73, 76 based on the detected temperature at the temperature measurement point a. The upper mold 41, the spark plug nest 52, the lifter nest 53, and the horizontal mold are controlled by opening the lifter nested cooling water control valve 69, the horizontal cooling water control valve 72, and the lower mold cooling water control valve 75. 2, the controlling the cooling of the lower mold 43.
[0079]
The opening control timing of the upper mold cooling water control valve 63 is adjusted so that the cooling temperature at which the directional solidification is obtained at the portion of the upper mold 41 corresponding to the temperature detected by the thermocouple thermometer 54 at the temperature measurement point a. The timing of starting the supply of cooling water to the upper cooling water passage 55 by opening the cooling water control valve 63 is set in advance by confirming experimentally or by simulation.
[0080]
The opening control timing of the spark plug nest cooling water control valve 66 is set such that the ignition plug nest 52 has a cooling temperature at which directional solidification can be obtained at the portion of the spark plug nest 52 corresponding to the temperature detected at the temperature measurement point a by the thermocouple thermometer 54. The timing of starting the supply of cooling water to the spark plug nesting cooling water passage 56 by opening the plug nesting cooling water control valve 66 is set in advance by confirming experimentally or by simulation.
[0081]
The opening control timing of the lifter nest cooling water control valve 69 is adjusted so that the cooling temperature at which the directional solidification can be obtained at the portion of the lifter nest 53 corresponding to the temperature detected by the thermocouple thermometer 54 at the temperature measurement point a is set. The timing of starting the supply of the cooling water to the lifter nesting cooling water passage 57 by opening the water control valve 69 is set in advance by confirming experimentally or by simulation.
[0082]
The opening / closing control timing of the horizontal cooling water control valve 72 is set so that the cooling temperature at which the directional solidification can be obtained at the horizontal 42 corresponding to the temperature detected at the temperature measurement point a by the thermocouple thermometer 54 is set. The timing of starting the supply of the cooling water to the horizontal cooling water passage 58 by opening 72 is set in advance by confirming experimentally or by simulation.
[0083]
Similarly, the opening / closing control timing of the lower mold cooling water control valve 75 is set to a cooling temperature at which directional solidification can be obtained in the lower mold 43 corresponding to the temperature detected at the temperature measurement point a by the thermocouple thermometer 54. The timing of starting the supply of cooling water to the lower cooling water passage 59 by opening the lower cooling water control valve 75 is set in advance by confirming experimentally or by simulation.
[0084]
Further, when the temperature at the temperature measurement point a has dropped to the set temperature confirmed experimentally or by simulation in advance, a signal is sent to the control unit as a hot water supply time release signal of the thermocouple thermometer 54. Further, the temperature at the temperature measurement point a continued to decrease as the solidification progressed and became a casting, and the temperature at the time when the temperature dropped to a temperature at which deformation and galling did not occur even when the mold 40 was released was experimentally determined in advance. Alternatively, it is confirmed and set by a simulation, and when the temperature reaches this temperature, an electric signal is transmitted from the thermocouple thermometer 54 to the control unit as a coagulation time setting release signal.
[0085]
Next, the casting method using the low-pressure casting apparatus 1 configured as described above will be described with reference to the explanatory diagram of the casting cycle in FIG. 5, the flowchart of the filling operation in FIG. 6, and the flowchart of the filling and cooling operation in FIG.
[0086]
Prior to pouring the molten metal 80 into the cavity 44 of the mold 40, the molten metal is stuffed until the molten metal surface 80a reaches a constant molten metal surface position set at or near the upper end of the stalk 33 of the casting machine 30.
[0087]
This filling operation is prepared by injecting a molten metal 80 in which an aluminum alloy has been melted into the molten metal tank 12 of the holding furnace 10 and storing it in a predetermined amount.
[0088]
Then, the discharge port 19a opened at the base end of the hot water supply pipe 19 is closed by the discharge port side valve body 20 according to an instruction from the control unit according to a preset program (step S1). Subsequently, the suction port 17a of the pressurizing pot 17 closed by the suction port side valve body 18 is opened to communicate the inside of the molten metal tank 12 and the pressurizing pot 17 (step S2). Next, the inside of the pressurizing pot 17 is depressurized by the vacuum pump 22 via the suction and air supply pipe 21, and the molten metal 80 in the molten metal tank 12 is sucked from the suction port 17a to near the upper end of the pressurizing pot 17 (step S3). . When the level sensor detects that the molten metal 80 has been sucked up to the vicinity of the upper end of the pressurizing pot 17, the pressure reduction in the pressurizing pot 17 by the vacuum pump 22 is stopped, and the suction port 17 a is controlled by the suction side valve element 18. Is closed (step S4).
[0089]
Next, compressed air is supplied from the suction and air supply pipe 21 into the pressurizing pot 17 by the pressurizing pump 23 to pressurize the melt surface, and the discharge port 19a closed by the discharge port side valve body 20 is opened ( In step S5, the molten metal 80 in the pressure pot 17 is pushed up to the constant molten metal surface position L set in the stalk 33 through the hot water supply pipe 19 (step S6).
[0090]
When the molten metal 80 is pushed up to the constant molten metal surface position, the molten metal surface 80a in the stalk 33 rises toward the temperature measuring point a of the thermocouple thermometer 54 provided on the casting pin 51 as the molten metal 80 is pushed up. As shown in FIG. 5, the temperature at the temperature measuring point a rises and reaches a temperature A at which the molten metal surface 80a is located at a constant molten metal surface position obtained experimentally or by simulation in advance. Is detected by the thermocouple thermometer 54. When the thermocouple thermometer 54 detects the molten metal surface 80a pushed up to the constant molten metal surface position (step S7), the molten metal surface detection signal is sent from the thermocouple thermometer 54 to the control unit, and the pressure is measured by the pressurizing pump 23. Pressurization in the pressurizing pot 17 is stopped, and at the same time, the discharge port 19a is closed by the discharge port side valve body 20 to prevent the backflow of the molten metal 80 from the stalk 33 and maintain the constant molten metal surface pressure. The molten metal surface 80a is held at the constant molten metal surface position (step S8).
[0091]
Following the filling operation from step S1 to step S8, a filling operation for filling the molten metal 80 into the cavity 44 of the mold 40 is started. The filling operation and the cooling operation will be described with reference to the explanatory diagram of the casting cycle in FIG. 5 and the filling and cooling operation flowchart in FIG.
[0092]
In a state where the discharge port 19a is closed by the discharge port side valve element 20 and the hot water surface 80a in the stalk 33 is held at the constant molten metal surface position (step S11), the suction port 17a closed by the suction port side valve element 18 is closed. The pressure holding of the constant molten metal surface in the opening pressure pot 17 is released (step S12).
[0093]
Next, the pressure inside the pressure pot 17 is reduced by the vacuum pump 22 via the suction / air supply pipe 21 and the molten metal 80 for one casting of the cavity 44 is sucked into the pressure pot 17 from the suction port 17a (step S13). . When the hot water 80 for one casting is sucked into the pressurizing pot 17, the pressure reduction by the vacuum pump 22 is stopped, and the suction port 17a is closed by the suction side valve element 18 (step S14). The amount of molten metal for one casting sucked and supplied to the pressurizing pot 17 is obtained in advance experimentally or by simulation, and is fixed by detecting suction to a certain position by a level sensor provided in the pressurizing pot 17. Secure quantity.
[0094]
Subsequently, compressed air is supplied from the suction / air supply pipe 21 into the pressurizing pot 17 by the pressurizing pump 23 to pressurize the molten metal surface, and the discharge port 19a closed by the discharge port valve 20 is opened (step). S15). The molten metal 80 is pressure-fed into the stalk 33 from the opened discharge port 19a through the hot water supply pipe 19 to push up the molten metal surface 80a and fill the cavity 44 of the mold 40, and the pressure required for the filling, that is, the filling pressure Is maintained (step S16). Due to the heat of the molten metal 80 filled in the cavity 44, the temperature of the temperature measurement point a set on the casting pin 51 starts to rise as shown in FIG. 5, and the temperature detected by the thermocouple thermometer 54 rises. I do.
[0095]
When the temperature of the temperature measuring point a reaches a preset upper mold cooling start temperature B, for example, 590 ° C., due to the heat of the molten metal, an upper signal is outputted from the upper mold temperature controller 64 based on the temperature detection by the thermocouple thermometer 54. The mold cooling water control valve 63 is opened, cooling water is supplied from the cooling water supply source 61 to the upper mold cooling water passage 55 via the supply path 62, and the cooling of the upper mold 41 is started (step S17). Further, the temperature of the temperature measurement point a rises due to the heat of fusion and reaches the highest point, for example, 600 ° C., and then the molten metal 80 filled in the cavity 44 starts to solidify from the upper end far from the gate 45, and the progress of this solidification As a result, the temperature at the temperature measurement point a starts to decrease.
[0096]
When the temperature of the temperature measurement point a falls to a preset lifter nest cooling start temperature C, for example, 595 ° C., the lifter nest cooling water is supplied by an open signal from the lifter nest temperature controller 70 based on the temperature detection by the thermocouple thermometer 54. The control valve 69 is opened, the cooling water is supplied from the cooling water supply source 61 to the lifter nest cooling water passage 57 via the supply path 68, and the cooling of the lifter nest 53 starts (step S18).
[0097]
Further, when the temperature of the temperature measurement point a falls and reaches a preset ignition plug nest cooling start temperature D, for example, 583 ° C., the ignition plug nest temperature controller 67 based on the temperature detection by the thermocouple thermometer 54 outputs the temperature. In response to the open signal, the ignition plug nesting cooling water control valve 66 is opened, cooling water is supplied from the cooling water supply source 61 to the ignition plug nesting cooling water passage 56 via the supply path 65, and the cooling of the ignition plug nesting 52 is started ( Step S19).
[0098]
Further, when the temperature of the temperature measurement point a decreases and reaches a preset horizontal cooling start temperature E, for example, 572 ° C., the horizontal type cooling controller 73 receives an open signal from the horizontal temperature controller 73 based on the detection of the temperature by the thermocouple thermometer 54 and outputs a horizontal type cooling signal. The cooling water control valve 72 is opened, the cooling water is supplied from the cooling water supply unit 61 to the horizontal cooling water passage 58 via the supply path 71, and the cooling of the horizontal die 42 is started (step S20).
[0099]
Further, when the temperature of the temperature measurement point a falls and reaches a preset lower mold cooling start temperature F, for example, 548 ° C., an open signal from the lower mold temperature controller 76 based on the detection of the temperature by the thermocouple thermometer 54. As a result, the lower mold cooling water control valve 75 is opened, the cooling water is supplied from the cooling water supply source 61 to the lower mold cooling water passage 59 via the supply path 74, and the cooling of the lower mold 43 is started (step S21).
[0100]
The solidification proceeds to the gate 45, the temperature at the time when the temperature at the temperature set point a decreases and the solidification proceeds to the preset temperature measurement point a, that is, the pressurization stop temperature G, for example, 530 ° C., is changed to a thermocouple. When the thermometer 54 detects (step S22), a pouring time release signal is sent from the thermocouple thermometer 54 to the control unit, and the pressurization in the pressurizing pot 17 by the pressurizing pump 23 is stopped to release the filling pressure. At the same time, the discharge port 19a is closed by the discharge port side valve body 20 to prevent the backflow of the molten metal 80 from the stalk 33, and the molten metal surface 80a is maintained at the constant molten metal surface position by maintaining the constant molten metal surface pressure ( Step S23).
[0101]
Further, the solidification in the cavity 44 progresses, and the temperature at the temperature set point a continues to drop, so that the solidified and cast product does not undergo deformation or galling even when the mold 40 is released. When the thermocouple thermometer 54 detects H, for example, 490 ° C., the upper mold temperature controller 64, the ignition plug nesting temperature controller 67, the lifter nesting temperature controller 70, the horizontal temperature controller 73 based on the temperature detection by the thermocouple thermometer 54, The upper mold cooling water control valve 63, the spark plug nesting cooling water control valve 66, the lifter nesting cooling water control valve 69, the horizontal cooling water control valve 72, and the lower cooling water control are operated by the closing signal from each controller of the lower mold temperature controller 76. Each control valve of the valve 75 is closed, the upper cooling water passage 55, the ignition plug nesting cooling water passage 56, the lifter nesting cooling water passage 57, The supply of the cooling water to each of the cooling water passages of the water passage 58 and the lower mold cooling water passage 59 is stopped (step S24), and a coagulation time release signal is sent from the thermocouple thermometer 54 to the control unit, and the mold clamping device 35 and the like are provided. The mold 40 is opened, the casting solidified in the cavity 44 is taken out, and one casting cycle is completed (step S25). Thereafter, the mold 40 is closed and the next molten metal filling standby state is set.
[0102]
Subsequently, the filling and cooling operations performed repeatedly are performed by the suction port side valve element 18 with the discharge port 19a closed by the discharge port side valve element 20 and the molten metal surface 80a in the stalk 33 held at the constant molten metal surface position. From step S11 of opening the constant molten metal surface pressure in the pressurizing pot 17 by opening the mold 17a, the mold 40 is opened and the mold 40 is taken out through the step S25 of taking out the solidified casting in the cavity 44, and the mold 40 is closed to wait for the next molten metal filling. The casting is repeatedly performed continuously by repeating the step of setting the state.
[0103]
According to the present embodiment, the part of the gate 45 which becomes the final solidified portion of the molten metal filled in the cavity 44 and changes at each casting cycle is set as the temperature measurement point a, and the upper die 41 corresponding to the detected temperature change, The upper mold cooling control valve 63, the spark plug nesting cooling water control valve 66, and the lifter nesting cooling water control valve 69 that provide a cooling temperature at which directional solidification can be obtained in the ignition plug nest 52, the lifter nest 53, the horizontal mold 42, and the lower mold 43. , The horizontal cooling water control valve 72, the lower cooling water control valve 75, the upper cooling water passage 55, the ignition plug nested cooling water passage 56, the lifter nested cooling water passage 57, the horizontal cooling water passage 58, and the lower cooling water The timing of supplying the cooling water to the passage 59 is set in advance by confirming it experimentally or by simulation, and the upper die cooling water control is performed based on the temperature change at the temperature measurement point a. 63, an ignition plug nested cooling water control valve 66, a lifter nested cooling water control valve 69, a horizontal cooling water control valve 72, and a lower cooling water control valve 75 to control the upper cooling water passage 55, the ignition plug nested cooling water passage. The cooling water is supplied to the cooling water passage 57, the lifter nesting cooling water passage 57, the horizontal cooling water passage 58, and the lower cooling water passage 59, and the upper die 41, the ignition plug nest 52, the lifter nesting 53, the horizontal die 42, and the lower die 43 are stepped. Cooling speed makes it possible to accelerate the solidification rate while achieving directional solidification, and achieves ideal mold cooling, and is expected to improve the quality of castings and improve productivity by shortening the casting cycle it can.
[0104]
Further, based on the temperature measured at the temperature measurement point a by the thermocouple thermometer 54 provided on the casting pin 51, the upper die cooling water control valve 63, the ignition plug nesting cooling water control valve 66, the lifter nesting cooling water control valve 69, Since the horizontal cooling water control valve 72 and the lower cooling water control valve 75 are controlled, the arrangement of thermocouple thermometers in each of the upper die 41, the spark plug insert 52, the lifter insert 53, the horizontal die 42, and the lower die 43 is omitted. As a result, simplification of the mold can be obtained, and causes of problems such as a decrease in the accuracy of the thermocouple thermometer and an insulation failure of the compensating lead wire are extremely reduced, so that a decrease in the quality of the cast product can be avoided. Furthermore, simplification of maintenance for preventing such occurrence can be obtained.
[0105]
In casting a cylinder head for an aluminum alloy water-cooled engine weighing about 9 kg with the low-pressure casting apparatus 1, directional solidification can be achieved and the casting cycle can be shortened as compared with the conventional casting method shown in FIGS. 9 and 10 described above. It was reduced to 1/3. Further, the incidence of internal defects such as internal cavities was improved by 3%.
[0106]
It should be noted that the present invention is not limited to the above embodiment, but can be variously modified without departing from the spirit of the invention. For example, in the above embodiment, the mold 40 for casting a cylinder head having the upper die 41, the horizontal die 42, the lower die 43, the cast pin 51, the spark plug insert 52, and the lifter insert 53 has been described as an example. The present invention can be applied to a mold for casting a casting. Further, in the above-described embodiment, the low-pressure casting apparatus 1 including the holding furnace 10 and the casting machine 30 has been described as an example. However, the molten metal tank is arranged below the mold, and the stalk that hangs from the mold into the molten metal tank. Can be applied to mold cooling of a low-pressure casting apparatus having
[0107]
【The invention's effect】
According to the mold cooling control method of the low-pressure casting machine and the invention of the mold of the low-pressure casting machine described above, the temperature of the molten metal at the gate portion that changes with each casting cycle becomes the final solidification part of the molten metal filled in the cavity. The control timing of the cooling means, which is the cooling temperature at which the directional solidification can be obtained in each part of the mold corresponding to the change, is set beforehand experimentally or by simulation and set, and based on the molten metal temperature detection at the gate section. By controlling the cooling means provided in each part of the mold, it is possible to promote the solidification rate while aiming for directional solidification, and to achieve ideal mold cooling, to improve the quality of the cast product and Productivity can be improved by shortening the casting cycle.
[0108]
Furthermore, since the cooling of each part of the mold is controlled based on the temperature detected by the single temperature detecting means, it is not necessary to arrange the temperature detecting means in each mold constituent member, and the mold can be simplified. As a result, the occurrence of problems such as a decrease in the accuracy of the temperature detecting means and an insulation failure of the compensating lead wire is extremely reduced, the deterioration of the quality of the cast product can be avoided, and the maintenance can be simplified.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a low-pressure casting apparatus showing an outline of an embodiment of a mold cooling control method of a low-pressure casting apparatus and a mold of the low-pressure casting apparatus according to the present invention.
FIG. 2 is a schematic view of a main part of the low-pressure casting apparatus in FIG. 1;
FIG. 3 is an explanatory view of a mold.
FIG. 4 is also a cooling water control circuit diagram.
FIG. 5 is also an explanatory diagram of a casting cycle.
FIG. 6 is also a flowchart of a hot water filling operation.
FIG. 7 is a flowchart of a charging and cooling operation.
FIG. 8 is a schematic explanatory view of a conventional low pressure casting apparatus.
FIG. 9 is an explanatory view of a conventional mold.
FIG. 10 is also a cooling water control circuit diagram.
[Explanation of symbols]
1 Low pressure casting equipment
33 Stoke
40 mold
41 Upper mold (mold component)
42 horizontal type (mold component)
43 Lower mold (mold component)
44 cavities
45 gate
51 Cast Pin
51c tip
52 Ignition plug nest (mold component, nest)
53 Lifter nesting (mold components, nesting)
54 Thermocouple thermometer (temperature detection means)
55 Upper cooling water passage (cooling means, cooling water passage)
56 Ignition plug nested cooling water passage (cooling means, cooling water passage)
57 Lifter nested cooling water passage (cooling means, cooling water passage)
58 Horizontal cooling water passage (cooling means, cooling water passage)
59 Lower cooling water passage (cooling means, cooling water passage)
61 Cooling water supply source
62 Supply path
63 Upper type cooling water control valve
64 Upper mold temperature controller
65 Supply channel
66 Ignition plug nested cooling water control valve
67 Spark plug nesting temperature controller
68 Supply path
69 Lifter nesting cooling water control valve
70 Lifter Nesting Temperature Controller
71 Supply channel
72 Horizontal cooling water control valve
73 Horizontal Temperature Controller
74 Supply channel
75 Lower cooling water control valve
76 Lower temperature controller
80 molten metal

Claims (6)

A low-pressure casting apparatus having a mold having a vertically extending stalk and a continuous cavity formed at the upper end of the stalk via a sprue, and filling and casting the molten metal into the cavity via the stalk. Mold cooling control method,
A mold cooling control method for a low-pressure casting apparatus, comprising: detecting a temperature of a molten metal in a gate section; and controlling cooling means provided in each section of the mold in accordance with the detected temperature. A mold having a cavity formed by a plurality of mold components; and a stalk extending vertically and having an upper end continuous with the cavity through a gate formed in the mold component. In a mold cooling control method of a low-pressure casting apparatus for casting by filling a molten metal into the cavity through the above,
Temperature detection means for detecting the temperature of the molten metal at the gate,
A cooling water passage formed in each of the mold components that is continuous with the cooling water supply source through each cooling water control valve,
A mold for a low-pressure casting apparatus, wherein the cooling water control valve is opened and closed according to the temperature detected by the temperature detecting means to supply cooling water from a cooling water supply source to the respective cooling water passages. Cooling control method. A mold having a cavity formed by a plurality of mold components; and a stalk extending vertically and having an upper end continuous with the cavity through a gate formed in the mold component. In a mold of a low-pressure casting apparatus for filling and casting a molten metal into the cavity through the above,
Temperature detection means for detecting the temperature of the molten metal at the gate,
A cooling water passage formed in each of the mold components connected to the cooling water supply source via each cooling water control valve that is controlled to open and close in accordance with the temperature detected by the temperature detecting means. Die for low pressure casting equipment. An upper mold, a lower mold having a sprue formed therein, a mold having a cavity formed by a horizontal mold disposed between the lower mold and the upper mold, and a vertically extending upper end passing through the sprue. Having a continuous stalk with the cavity, and a mold of a low-pressure casting apparatus for filling the cavity with the molten metal through the stalk and casting.
Temperature detection means for detecting the temperature of the molten metal at the gate,
An upper cooling water passage formed in the upper die that is continuous with the cooling water supply source through an upper cooling water control valve that is controlled to open and close according to the temperature detected by the temperature detecting unit;
A lower cooling water passage formed in the lower die connected to a cooling water supply source via a lower cooling water control valve that is opened and closed according to the temperature detected by the temperature detecting means,
A horizontal cooling water passage formed in a horizontal shape that is continuous with a cooling water supply source via a horizontal cooling water control valve that is opened and closed according to the temperature detected by the temperature detecting means. Mold. The mold has a nest,
5. A nested cooling water passage formed in the nest connected to a cooling water supply source via a nested cooling water control valve that is controlled to open and close according to the temperature detected by the temperature detecting means. A mold for the low-pressure casting apparatus as described. The mold has a cast pin whose tip projects into the gate,
6. The low pressure device according to claim 3, wherein the temperature detecting means is a thermocouple thermometer provided on the casting pin and having a temperature measuring point near a tip of the casting pin. Mold for casting equipment.

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