JP5040253B2 - Gravity casting method and die for gravity casting - Google Patents

Description

This invention relates to gravity casting method and gravity casting mold, more particularly to prevent the entrainment of air when filling the molten metal within the mold, gravity casting method and to prevent casting defects of the casting product it relates to gravity casting mold.

  Conventionally, as one of the gypsum mold gravity casting methods, for example, as shown in FIG. 5, a lower mold 2 (lower mold) for installing a gypsum mold 1 and a horizontally openable and closable arrangement on the lower mold 2 are provided. The divided upper molds 3a and 3b (upper molds) are provided, and the molten metal W supplied from the tiltable water heater 4 (or hot water ladle) is provided in the divided upper molds 3a and 3b. Gravity in which casting is performed by sequentially filling the hot water supply port portions 6a and 6b of the runway 5 into the runner portion 7, the cavity of the product portion 8 of the gypsum mold 1 and the lower mold 2, and the upper molds 3a and 3b and the feeder 9 A casting method is known (see, for example, Patent Document 1).

  Moreover, since the initial molten metal W supplied with hot water flows on the surface 1a of the gypsum mold 1 through the runner 5 → the runner portion 7, the molten metal W is heated at the temperature of the molten metal W, so-called “overheating phenomenon”. Occurs. As a principle of casting work, the molten metal W supplied with hot water is slowly filled into the cavities of the product part 8 of the gypsum mold 1, the lower mold 2, and the upper molds 3 a, 3 b, and further sequentially filled toward the feeder part 9. Desirably, the filled molten metal W is preferably cured sequentially from the surface 1a side of the gypsum mold 1 toward the feeder 9.

  However, since the gypsum mold 1 filled with the molten metal W is heated by the “overheating phenomenon” as described above and has a long thermal insulation state, the molten metal W is fed from the surface 1a side of the gypsum mold 1 to the feeder 9 It does not necessarily harden sequentially toward the surface, and the feeder 9 starts to harden in a state where the surface 1a side of the plaster mold 1 is not hardened. For this reason, there has been a problem that a casting defect on the product surface of the casting (a recess or the like is generated on the product surface) occurs due to the “sink failure” of the molten metal W, resulting in a product defect.

  Therefore, as shown in FIGS. 6A and 6B, a branch runner 5a communicating with the inside of the cavity of the product portion 8 is formed in the vicinity of the feeder 9 of the runner 5 (see, for example, Patent Document 1). ) In the initial stage of filling the molten metal W, the molten metal W is filled from the runner 5 through the runner portion 7 into the cavity on the surface 1a side of the gypsum mold 1 and the product portion 8, and the molten metal W filling middle plate includes a runner It is also possible to prevent the “overheating phenomenon” of the gypsum mold 1 by changing the hot metal supply path of the molten metal W from the portion 7 to the branch runner portion 5a and filling the product portion 8 with it.

However, the hot water supply path of the molten metal W cannot be easily changed due to the flow rate of the molten metal W, the amount of the molten metal, the temperature of the molten metal and the mold, and the ratio of the cross-sectional area of the runner. There was a problem in that a product defect occurred due to the occurrence of a recess in the product part.
JP-A-7-290227 Japanese Patent Laid-Open No. 10-29054

This invention pays attention to such a conventional problem, and when filling molten metal, the hot water supply path is simply and reliably performed, the “overheating phenomenon” of the gypsum mold is prevented, and the molten metal is filled in the mold. the entrainment of air is prevented when, it is an object to provide a gravity casting method and gravity casting mold and improve the casting defects of the casting product.

In order to achieve the above object, according to the present invention, the gravity casting method of the present invention fills the molten metal into the cavity of the product part of the casting mold from the cavity of the product part to the feeder part sequentially through a plurality of runners. In the gravity casting method, the amount of molten metal filled in the cavity of the product portion is detected by the amount of molten metal detection means when the predetermined amount of molten metal is filled in the cavity of the product portion, and the amount of molten metal detection means Based on the detected value, the gist is to change the hot water path of the molten metal to the branch runner part on the side of the feeder part by shutting off the runner part in the vicinity of the product part by the shut-off means via the control device. is there.

Here, before Symbol blocking means is a blocking member for blocking the cooling means or runner part physically.

The gravity casting mold of the present invention is a gravity casting mold in which a plurality of runners are formed in the casting mold from the product part in the cavity toward the feeder part, and the cavity is filled. in response to loading of the molten metal to block the runner portion of the product portion near to be, the shut-off means for changing the hot water path of the molten metal in the branch runner portion of the feeder head portion is provided, the blocking means, the cavity The gist of the present invention is that a detection means for the molten metal filling amount is installed in the inside, and the runner portion in the vicinity of the product portion is blocked via the control device based on the detection value from the detection means .

Here, before SL loading detecting means, contact or non-contact of the molten metal level gauge, a temperature sensor, ladle goniometer, is to use one selected from among the hot water timer.

  Further, the blocking means is a cooling means for cooling the runner near the product part, and the blocking means is a closing means for closing the runner near the product part.

  Since the present invention is configured as described above, when filling the molten metal, the hot water supply path is simply and reliably performed, the “overheating phenomenon” of the gypsum mold is prevented, and the molten metal is filled inside the mold. It is possible to prevent air entrainment and improve casting defects of casting products.

Since the present invention is configured as described above, the following excellent effects can be obtained. (a) When filling with molten metal, the hot water supply path can be easily and reliably performed.
(b) It is possible to prevent the “overheating phenomenon” of the plaster mold and to stabilize the quality by preventing product defects.
(c) The air can be prevented from being caught when the molten metal is filled in the mold, and the casting product can be prevented from being poorly cast.
(d). Work efficiency is good and productivity can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
Note that the same components as those in the conventional example are denoted by the same reference numerals and description thereof is omitted.

  FIG. 1 shows a schematic configuration diagram of a gravity casting mold for carrying out the gravity casting method according to the first embodiment of the present invention, wherein 1 is a gypsum mold and 2 is a lower mold (lower mold) on which a gypsum mold 1 is installed. 3), 3a, 3b are divided upper molds (upper molds) arranged to be openable and closable in the horizontal direction, 4 is a tiltable hot water furnace (or hot water ladle) provided with an angle meter 4a, The upper molds 3 a and 3 b are respectively formed with hot water supply port portions 6 a and 6 b of the runner 5, a runner portion 7, and a cavity of the product portion 8 that communicates with the runner portion 7 and a feeder 9. ing.

  Further, a branch runner part 5a communicating with the cavity of the product part 8 is formed in the vicinity of the hot water feed part 9 of the runner 5, and at the initial filling stage of the molten metal W, the runner 5 passes through the runner part 7. The surface of the plaster mold 1 is filled in the cavity of the product portion 8 and the product portion 8, and in the middle of the molten metal W, the hot water supply path of the molten metal W is changed from the runner portion 7 to the branch runner portion 5 a. The unit 8 is configured to be filled.

  In the runner 7, the runner 7 in the vicinity of the product 8 is blocked in accordance with the filling amount of the molten metal filled in the cavity of the product 8, and the molten metal path is connected to the feeder 7 side. There is provided a blocking means 10 for changing to the branch runner 5a. That is, the amount of molten metal filled in the cavity of the product portion 8 is detected by the hot water amount detecting means 11, and based on the detected value of the hot water amount detecting means 11, the product is near the product portion by the blocking means 10 via the control device 12. The runner portion 7 is configured to be cut off.

  As the blocking means 10, for example, in a pipe or mold in which a cooling medium such as cold water or compressed air is embedded in a mold near the runner 7 as in the second embodiment of the present invention shown in FIG. FIG. 2 (a), (b) and FIG. 3 (a), (b) show cooling means for cooling and hardening the molten metal W in the runner 7 through the cooling holes 13 formed in FIG. As in the first embodiment, it is conceivable to be a physical blocking means constituted by a control valve or the like that blocks the runner 7 with the shut pin 14 or the shielding plate 15 or the like.

  As shown in FIG. 4, the cooling means is provided with a control valve 16 such as a hand valve or an electric valve provided in a part of the cooling hole 13 or a pipe for circulating a cooling medium. A cooling medium is circulated in the hole 13. Reference numeral 17 denotes a molten metal coagulation detection device of the runner 7 connected to the control device 12. As the molten metal coagulation detection device 17, a temperature sensor, a timer or the like is used.

  Further, the shut pin 14 and the shielding plate 15 as the physical blocking means are a cylinder connected to the control device 12 as shown in FIGS. 2 (a) and 2 (b) and FIGS. 3 (a) and 3 (b). The runner 7 is opened and closed by operating the shut pin 14 and the shielding plate 15 via the driving means 18. Further, a hot water amount detecting means 11 for detecting the filling amount of the molten metal is installed in the cavity of the product portion 8, and based on the detection value from the hot water amount detecting means 11, the vicinity of the product portion 8 is provided via the control device 12. The runner 7 is blocked. The hot water amount detecting means 11 is selected from a contact or non-contact molten metal level gauge, a temperature sensor, a ladle angle meter, and a hot water timer, and the control device 12 detects from the hot water amount detecting means 11. Use the one that can perform sequence control based on the value.

  Next, the gravity casting method of the present invention will be described using the above gravity casting mold.

  First, in the case of a gravity casting mold provided with the physical blocking means 10 shown in FIGS. 1 to 3, the gypsum mold 1 is installed on the lower mold 2 (lower mold) and can be opened and closed horizontally. Molten metal from a tiltable hot water furnace (or hot water ladle) provided with an angle meter 4a at the hot water supply port portions 6a, 6b of the runway 5 with the upper molds (upper molds) 3a, 3b disposed in W water is supplied.

  And the molten metal W supplied with hot water is gradually filled into the cavity of the product part 8 from the runway 5 through the runner part 7, and when a predetermined amount of molten metal is filled into the cavity of the product part 8, The amount of the molten metal filled is detected by the hot water amount detecting means 11, and based on the detected value of the hot water amount detecting means 11, the shutoff means 10 is used to shut off the runner portion 7 in the vicinity of the product portion via the control device 12. The hot water supply path of the molten metal W is changed from the road portion 7 to the branch runner portion 5a to fill the cavity of the product portion 8 and the hot water supply portion 9 with each other.

  Specifically, when a preset amount of molten metal is detected by the molten metal amount detection means 11, a signal of the detected value is output to the control device 12, and the driving means 18 such as a cylinder is operated by the control signal from the control device 12. Then, in the direction of closing the shut pin 14 and the shielding plate 15, for example, in the case of the shut pin 14, the runner portion 7 near the product portion is operated by operating as (a) → (b) in FIG. In the case of the shielding plate 15, the runner portion 7 in the vicinity of the product portion is shut off by operating as shown in FIG. 3 in the order of (a) → (b). The hot water supply from the hot water is cut off and flows into the cavity of the product portion 8 from the branch runner portion 5a.

  Then, the filled molten metal is gradually filled from the cavity of the product part 8 to the feeder part 9, and the “overheating phenomenon” of the gypsum mold 1 is also prevented, thereby preventing product defects and stabilizing the quality. It can be planned.

  The operation timing for closing the shut pin 14 and the shielding plate 15 by the control device 12 via the hot water amount detecting means 11 when a predetermined amount of molten metal is filled in the cavity of the product portion 8 depends on the size of the mold. Although it cannot be set uniformly, it is preferable to shut off the runner part 7 when the molten metal filled in the cavity of the product part 8 is located in the vicinity of the branch runner part 5a.

  That is, if the runner 7 is shut off in a state where the amount of hot water in the cavity of the product portion 8 is small, there is a possibility that the molten metal W is caught in the air, and the molten metal is filled to the vicinity of the feeder 9. Thereafter, when the runner 7 is blocked, it is difficult to prevent the “overheating phenomenon” of the gypsum mold 1. Therefore, it is preferable to control the shut pin 14 and the shielding plate 15 to be closed when the filling amount of the molten metal W is optimum.

  Next, as a gravity casting method of the second embodiment in the case of a gravity casting mold provided with cooling means as the blocking means 10 shown in FIG. 4, first, a gypsum mold is placed on the lower mold 2 (lower mold). 1 is installed, and the upper molds (upper molds) 3a and 3b disposed so as to be opened and closed in the horizontal direction are closed, and the tilting type is provided with the goniometer 5 at the hot water supply ports 6a and 6b. Molten metal W is supplied from a hot water furnace (or hot water ladle).

  And the molten metal W supplied with hot water is gradually filled into the cavity of the product part 8 from the runway 5 through the runner part 7, and when a predetermined amount of molten metal is filled into the cavity of the product part 8, The amount of molten metal filled is detected by the hot water amount detecting means 11, and based on the detected value of the hot water amount detecting means 11, cooling of cold water (or compressed air) or the like is made in the cooling hole 13 of the cooling means via the control device 12. The medium is circulated to cool and harden the molten metal W in the runner 7, and the cured molten metal W blocks the passage of the runner 7, whereby the molten metal W supplies hot water from the runner 7. When it is cut off, it flows into the cavity of the product portion 8 from the branch runner 5a.

  As described above, the cooling means is provided with a control valve 16 such as a hand valve or an electric valve in a part of the piping or the cooling hole 13 through which the cooling medium flows, and based on a signal command from the control device 12 or the like, the control valve 16 Is opened and closed to circulate or block the cooling medium in the piping and the cooling hole 13. In order to perform more accurate control, a molten metal coagulation detection device 17 (temperature sensor, timer, etc.) of the runner 7 connected to the control device 12 is connected so that the molten metal W in the runner 7 can be controlled. The coagulation state is detected.

  When the solidified state of the molten metal W in the runner 7 is confirmed by the cooling means, the control valve 16 stops the flow of the cooling medium in order to prevent the mold from being cooled. In this way, when the runner portion 7 in the vicinity of the product portion is shut off, the hot water supply path of the molten metal W is changed from the runner portion 7 to the branch runner portion 5a, and the inside of the cavity of the product portion 8 and the hot water supply portion 9 are filled. Will be. Since other operations are the same as those in the first embodiment, detailed description thereof is omitted.

  In this way, the filled molten metal is gradually filled from the cavity of the product part 8 into the feeder part 9, and the “overheating phenomenon” of the gypsum mold 1 is prevented, and foreign matters are effectively mixed. It is possible to prevent product defects and to stabilize the quality.

  Further, when the predetermined amount of molten metal is filled in the cavity of the product portion 8, the operation timing in which the cooling medium is circulated by the control device 12 via the molten metal amount detecting means 11 and the molten metal solidification detecting device 17 is the size of the mold. However, it is preferable to control when the molten metal filled in the cavity of the product part 8 is located in the vicinity of the branch runner part 5a or by determining the solidification state.

  By the above method, when filling with molten metal, the hot water supply path can be performed easily and reliably, and the “overheating phenomenon” of the gypsum mold 1 is prevented, and foreign matters are effectively prevented from being mixed. Therefore, product quality can be prevented and quality can be stabilized.

  In addition, by manufacturing a pneumatic tire manufacturing mold using the above-described gravity casting mold, a tire with stable quality and good appearance can be manufactured.

It is a schematic block diagram of the gravity casting die for enforcing the gravity casting method which shows 1st Embodiment of this invention. (A), (b) is explanatory drawing of the operation state of the shut pin as a physical interruption | blocking means in 1st Embodiment. (A), (b) is explanatory drawing of the operation state of the shielding board as a physical interruption | blocking means in 1st Embodiment. It is a schematic block diagram of the metal mold | die for gravity casting for enforcing the gravity casting method which shows 2nd Embodiment of this invention. It is a vertical front view of the conventional gravity casting mold. (A), (b) is a longitudinal cross-sectional explanatory drawing of the other conventional casting mold for gravity casting.

1 Gypsum mold 2 Lower mold (lower mold)
1a Surface 3a, 3b Upper mold (upper mold)
DESCRIPTION OF SYMBOLS 4 Tilt-type hot water furnace 4a Angle meter 5 Runway 6a, 6b Hot water supply part 7 Runway part 8 Product part 7a Branch runner part 9 Hot water supply part W Molten metal 10 Shut off means 11 Hot water amount detection means 12 Control apparatus 13 Cooling hole 14 Shut Pin 15 Shielding Plate 16 Control Valve 17 Molten Solidification Detection Device 18 Driving Means

Claims (6)

In the gravity casting method in which the molten metal is sequentially filled from the cavity of the product part to the feeder part through the plurality of runners in the cavity of the product part of the casting mold,
When a predetermined amount of molten metal is filled in the cavity of the product part, the amount of molten metal filled in the cavity of the product part is detected by the hot water amount detecting means, and control is performed based on the detection value of the hot water amount detecting means. A gravity casting method characterized in that a runner near the product part is shut off by a shutting means through an apparatus to change a molten metal path to a branch runner on the side of the feeder . The gravity casting method according to claim 1 , wherein the blocking means is a blocking member that physically blocks the cooling means or the runner. In a gravity casting mold in which a plurality of runners are formed from the product part in the cavity toward the feeder part in the casting mold,
Blocks the runner portion of the product portion near the corresponding to the filling amount of the molten metal to be filled into the cavity, provided with blocking means for changing the hot water path of the molten metal in the branch runner portion of the feeder head portion, the cut-off The means is characterized in that a means for detecting a molten metal filling amount is installed in the cavity, and the runner portion in the vicinity of the product portion is blocked through a control device based on a detection value from the detection means. Die for gravity casting. 4. The gravity casting mold according to claim 3 , wherein the molten metal filling amount detecting means is selected from a contact or non-contact molten metal level gauge, a temperature sensor, a ladle angle meter, and a hot water timer. The gravity casting mold according to claim 3 or 4 , wherein the blocking means is a cooling means for cooling the runner near the product portion. The gravity casting mold according to claim 3 , 4 or 5 , wherein the blocking means is a closing means for closing a runner near the product portion.

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