JP4330423B2 - Casting equipment - Google Patents

Description

  The present invention relates to a casting apparatus for casting a plate-like member.

  Some recent internal combustion engine cylinders are provided with a partition plate, also referred to as a tumble plate, in the intake port of the cylinder head. By controlling the airflow control valve arranged at the intake side end of the intake port, the intake air introduced from the intake port to the cylinder bore is drifted by the partition plate, and the tumble flow (longitudinal vortex flow) generated in the cylinder bore is strengthened, The fuel consumption is improved (see Patent Document 1).

  In the present specification, in the partition plate, the side on which the intake air of air or fuel gas flows is referred to as “intake side”, and the opposite side, that is, the cylinder bore side is referred to as “cylinder side”.

  In the case of casting the cylinder head, it is common to place a metal partition plate in the intake port molding sand core and cast and mold the partition plate. During casting of the cylinder head, each of the core and the partition plate rises in temperature due to heat from the molten metal and expands thermally. Here, the difference between the thermal expansion coefficient of the partition plate and the thermal expansion coefficient of the core that holds the partition plate is large, and the partition plate has a larger amount of thermal expansion than the core. For this reason, the partition plate may pressurize or spread the core, causing cracks or breakage in the core, and the molten metal may ooze out from the crack, creating a burr. In addition, due to the thermal expansion of the partition plate, the position of the partition plate may be shifted during casting of the cylinder head. Further, in the cylinder head as a product after the completion of casting, the partition plate may be loose in the product. There is also.

  For this reason, depending on the location where the burrs are generated, not only the deburring work in post-processing is extremely troublesome, but also the quality of the product is deteriorated due to the displacement of the partition plate and the play in the product. Therefore, the thermal influence must be fully considered for the partition plate.

The partition plate disclosed in Patent Document 1 is formed in a corrugated shape as a countermeasure against deformation caused by thermal expansion when casting the partition plate during casting of the cylinder head. However, the wave-shaped partition plate can absorb the thermal expansion in the radial direction of the intake port, but cannot absorb the thermal expansion in the axial direction. For this reason, it is not possible to limit the locations where burrs are generated due to the cracking of the core due to the difference in thermal expansion between the partition plate and the core, and the position of the partition plate and the play in the product are not sufficient. It cannot be suppressed to.
JP-T-2001-193469 (see paragraph numbers 0011, 0020, 0022 and FIGS. 1, 3 and 4)

  The present invention has been made in view of the above circumstances, and it is intended to improve the product quality by sufficiently suppressing the positional deviation of the partition plate and the play in the product, and further, the burr caused by the cracking of the core. The purpose is to facilitate the deburring work in post-processing by limiting the occurrence locations.

  The present invention that achieves the above object is a casting apparatus that casts and forms a plate-like member previously set on a sand core so that both side edges protrude outward, and the thickness of the product that can be cast is A mold is provided that forms a larger cavity on the other end side than the one end side so as to be thicker on the other end side than the one end side of the plate-like member.

  According to the present invention, since the mold forms a larger cavity on the other end side than the one end side of the plate-like member, more molten metal is poured in the vicinity of the other end side than the one end side, and the one end side with less molten metal. Start to solidify first. As a result, one end side of the plate-like member is fixed first, the direction in which the plate-like member expands due to the heat of the molten metal can be limited or controlled in one direction, and the occurrence of burrs caused by cracks in the core is limited As a result, deburring work in post-processing can be facilitated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Below, the case where this invention is applied to the casting apparatus which casts a cylinder head and casts a partition plate in this cylinder head is demonstrated. However, the present invention is not limited to this, and can be applied to any casting apparatus that casts and forms a plate-like member.

  First, the cylinder head 10 manufactured by the casting apparatus of the present invention and having the partition plate 100 for the intake port 14 will be described. In the following description, the partition plate 100 for the intake port 14 is also referred to as a “tumble plate 100”.

  FIG. 1 is a schematic cross-sectional view showing a cylinder head 10 of the engine, FIG. 2 is a cross-sectional view perpendicular to the axis of the intake port 14, and FIG. 3 is a schematic view showing an air flow state in the cylinder head 10.

  Referring to FIGS. 1 and 3, a cylinder head 10 is provided on an upper portion of a cylinder block 11, and includes an intake port 14 for introducing an intake air flow including air and fuel gas from an intake manifold 12 into the cylinder bore 13, and a cylinder bore. 13 has an exhaust port 15 for discharging exhaust gas after burning in the interior. The illustrated engine has one cylinder and four valves, and two intake valves 16 and two exhaust valves 17 are provided.

  A partition plate 100 is provided in the intake port 14 along the flow direction of intake air (open arrow) flowing from the intake side (outer end side in FIG. 3) toward the cylinder side. As shown in FIG. 3, an intake manifold 12 provided with a control valve 18 is connected to the intake side of the partition plate 100. The intake port 14 is partitioned into an upper port 14u and a lower port 14d by the partition plate 100. When the lower port 14d is closed by the control valve 18, the intake air is accelerated and flows in the upper port 14u, and the cylinder bore A strong tumble flow (longitudinal vortex flow) will be formed within 13.

  In the intake port 14, the passage on the cylinder side is greatly bent, and if the position of the cylinder side end portion Ta of the tumble plate 100 varies, the characteristics of the air flow change, which greatly affects the generation state of the tumble flow. Therefore, the position of the cylinder side end portion Ta is an extremely important position. On the other hand, the position of the intake side end portion Tb of the tumble plate 100 is the side where the intake air is branched and the control valve 18 is provided. Therefore, even if the position varies, the characteristics of the airflow change. In general, it is not necessary to set the cylinder side end portion Ta as accurately as possible.

  Therefore, in the present embodiment, in the casting apparatus for casting the cylinder head 10, the position of the cylinder side end portion Ta is fixed by first solidifying the molten metal near the cylinder side end portion Ta of the tumble plate 100, The heat expansion of the tumble plate 100 due to the thermal influence of the molten metal can be absorbed on the relatively free intake side end portion Tb side.

  In the following, in order to facilitate the description of the configuration of the casting apparatus according to the present invention, the port core in which the tumble plate is previously installed, the state of forming the port core, and the port core in the mold are described below. The state of placing and casting will be described, and then the structure that is a feature of the present embodiment will be described.

(Port core)
FIGS. 4A and 4B are a plan view and a side view showing the port core 200 on which the tumble plate 100 is previously installed.

  As shown in FIGS. 4A and 4B, the tumble plate 100 according to the embodiment is installed in advance on an intake port molding sand core 200 that forms the intake port 14 of the cylinder head 10, and The intake port 14 of the cylinder head 10 is divided into a plurality of ports (upper port 14u and lower port 14d) by being cast at the time of casting. In the following description, the intake port molding sand core 200 on which the tumble plate 100 is installed in advance is also referred to as “port core 200”.

  More specifically, the tumble plate 100 has a substantially rectangular shape, and is continuous with the side edge portions Tc and the side edge portions Tc that are to be cast in the molten metal when the cylinder head 10 is cast, and within the intake port 14. An intake side end Tb to be disposed on the upstream side of the intake flow, and a cylinder side end Ta to be disposed on the downstream side of the intake flow while continuing to the side edges Tc. ing. The inner part of each side edge part Tc is a partition part 103 that partitions the inside of the intake port 14.

  The material of the tumble plate 100 is preferably an aluminum alloy in consideration of recyclability. The plate thickness of the tumble plate 100 is preferably thin so as not to cause resistance to intake air flowing through the intake port 14, but when the material of the tumble plate 100 is an aluminum alloy, the cast product of the cylinder head 10 is heat-treated. In consideration of the need to prevent thermal deformation at the time, the thickness is preferably about 1.5 mm or more.

  The tumble plate 100 may be chamfered on the intake side end Tb. There is a case where the end face of the cylinder head 10 to which the intake manifold 12 is connected is machined by a cutter or the like in post-processing after the casting of the cylinder head 10 is cast. In such a case, the cutting of the intake side end Tb of the tumble plate 100 is cut off. This is because the burrs can be suppressed more smoothly and the occurrence of burr during processing can be suppressed.

  Although the manufacturing method of the tumble plate 100 is not particularly limited, it is preferable to manufacture the tumble plate 100 by press molding from the viewpoint of easily and inexpensively manufacturing the tumble plate 100.

  The port core 200 is installed in a casting mold 400 for casting the cylinder head 10 (see FIG. 7) to form the intake port 14 of the cylinder head 10. This port core 200 is installed in advance so that the above-described tumble plate 100 protrudes to the outside so that both side edge portions Tc are cast in the molten metal.

  Both side edge portions Tc of the tumble plate 100 protruding to the outside are portions that make the holding more reliable when cast into the molten metal. The casting allowance is not particularly limited, but is set to about 2 mm, for example.

  In the cylinder head 10 after casting, both side edges Tc of the tumble plate 100 are not welded to the cylinder head 10. This is because, when welded, the tumble plate 100 may be fatigued due to repeated thermal shock and vibration received when used as an engine. Since the tumble plate 100 is not welded to the cylinder head 10, when viewed from the cylinder head 10, the cast-in part has a notch shape. For this reason, when the cast-in allowance is too large, the notch depth becomes deep and stress concentration occurs in the notch-shaped portion, which becomes a factor for reducing the structural strength of the cylinder head 10. Furthermore, in order to improve the water jacket cooling performance of the cylinder head 10 or to reduce the weight, the thickness of the cylinder head 10 may have to be partially or entirely reduced. Therefore, it is preferable that the casting allowance is as small as possible.

(How to mold the port core)
FIG. 5 is a schematic cross-sectional view showing a mold 300 for molding the port core 200. In the following description, the mold 300 for forming the port core 200 is also referred to as a “core mold 300”.

  When casting the cylinder head 10, first, the port core 200 shown in FIG. 4 is formed using the core mold 300 shown in FIG. 5.

  The core mold 300 is composed of a plurality of partial molds including a core upper mold 301 and a core lower mold 302. When these partial molds are brought into contact with each other, a cavity 303 for forming the port core 200 is formed therein. Core sand is blown into the cavity 303 and pressed to form the port core 200.

(Case where port core is placed for casting)
FIG. 6 is a plan view showing a state in which the mold 300 for molding the port core 200 is broken and the tumble plate 100 is exposed.

  As shown in FIG. 6, core sand is blown in a state where the tumble plate 100 is previously placed on the core mold 300, and the port core 200 is formed. The tumble plate 100 is positioned so as not to be displaced in the core mold 300, and is set on a seat formed on the mold matching surface of the core mold 300. That is, it is held in a state of being placed on the peripheral edge of the cavity of the core lower mold 302.

  The port core 200 molded in the core mold 300 is obtained by dividing the partial molds such as the core upper mold 301 and the core lower mold 302 in the dividing direction indicated by the arrows in FIG. 300 is taken out. In addition, the code | symbol 201 in FIG. 5 has shown the baseboard.

  FIG. 7 is a cross-sectional view showing a concept of a state in which the port core 200 is installed in a casting mold 400 for casting the cylinder head 10. In addition, in FIG. 7, the concept of the state in which the port core 200 is installed is shown, and illustration is omitted about the core pin and insert of the casting apparatus mentioned later.

  As shown in FIG. 7, the port core 200 is incorporated in a casting mold 400 for molding the cylinder head 10. The casting mold 400 includes an upper mold 401, a lower mold 402, and a side mold 403. When the port core 200 is supported between the lower mold 402 and the side mold 403 and covered with the upper mold 401, the cylinder head 10 is placed inside. A cavity 404 is formed for molding. Reference numeral “405” in the figure denotes a water jacket forming core and an oil passage forming core. As the casting method, for example, a low pressure casting method (LPDC) is adopted.

  In this state, when a molten metal made of an aluminum alloy or other metal is poured from the gate 500 into the cavity 404, the cylinder head 10 as shown in FIG. 1 is formed. During this pouring, the tumble plate 100 provided on the port core 200 is thermally expanded by the heat of the molten metal.

  In the present embodiment, the casting apparatus is more than the cylinder side end portion Ta side so that the thickness of the cast product is thicker on the intake side end portion Tb side than on the cylinder side end portion Ta side of the tumble plate 100. A large cavity is formed on the intake side end portion Tb side. In order to enlarge the cavity on the intake side end portion Tb side, that is, in order to reduce the cavity on the cylinder side end portion Ta side, the casting apparatus cylinders inserts (solidification adjusting inserts) that protrude from the mold into the mold. It arrange | positions in the side edge part Ta vicinity.

  By disposing the insert, the thickness of the product at the cylinder side end portion Ta is reduced, and solidification during casting starts on the cylinder side end portion Ta side before the cylinder side end portion Tb side. Thereby, the expansion direction can be controlled so that the tumble plate 100 expands toward the intake side end portion Tb.

  The arrangement position of the insert and how the insert acts on the molten metal will be described with reference to FIG. Since the insert is pulled out from the cylinder head 10 after casting, a trace of the insert being pulled out remains in the cylinder head 10. In the following, the insert is virtually indicated by a two-dot chain line in this trace, and indicates where the insert is arranged in the cylinder head 10 that is a product during casting. At the same time, it shows which part of the cylinder head 10 to be a product is provided with a molten metal gate during casting.

  FIG. 8 is a diagram virtually showing the insert in the cylinder head 10 after casting. FIG. 8A is a plan view showing a schematic configuration of the cylinder head 10, and FIG. 8B is a plan view of FIG. It is sectional drawing along the 8A-8A line.

  As shown in FIGS. 8A and 8B, when the cylinder head 10 is cast, the insert pin 5a, the cylinder bore insert 5b, and the insert pins 5c to 5d (hereinafter collectively referred to as inserts) are used. Then, the molten metal is poured in a state where the insert 5) is arranged in the mold. As a result, the insert 5 is inserted into the cylinder head 10 before finishing. Here, at the same time, the tumble plate 100 is cast in the cylinder head 10.

  Each of the inserts 5 is formed with a sloped surface so that it can be pulled out from the cylinder head 10 after casting. The trace from which the insert is pulled out is used for other purposes in the commercialization stage. For example, a part of the cylinder bore 13 is formed on the trace where the cylinder bore insert 5b is pulled out.

  In the present embodiment, the core pin 5c is provided so as to be inserted into the thick portion 19 of the product, and the thickness of the outer edge portion of the tumble plate is t1 <t2 <t3 from the cylinder bore side toward the intake side. Distribution. As a result, the thickness of the surplus portion 19 is reduced and the solidification of the molten metal near the surplus portion 19 is accelerated during casting. As a result, the solidification of the molten metal in the vicinity of the cylinder side end portion Ta of the tumble plate 100 close to the fillet portion 19 is accelerated.

  In this way, by providing the cast pin 5c in the surplus part 19, the thickness of the surplus part 19 can be reduced, and the solidification of the molten metal can be accelerated. In addition to thinning the thickness of the hollow portion 19 with the cast pin 5c, if the distance between the mold and the port core 200 is made larger on the intake side end portion Tb side than the cylinder side end portion Ta side, The cavity in the vicinity of the cylinder side end portion Ta becomes relatively small, and solidification in the vicinity of the cylinder side end portion Ta can be relatively accelerated.

  In the present embodiment, in addition to the provision of the core pin 5c, the plurality of inserts 5 are used to solidify the molten metal near the cylinder side end portion Ta of the tumble plate 100 relative to the intake side end portion Tb. To promote the effect. In the following, a method for accelerating solidification of the molten metal in the vicinity of the cylinder side end Ta will be described for each of the cases where the heat capacity of the insert 5 is changed, the thermal conductivity is changed, and the temperature of the insert 5 is controlled. To do.

(Change heat capacity of insert)
By adjusting the heat capacity of the insert 5, solidification of the molten metal in the vicinity of the cylinder side end portion Ta of the tumble plate 100 can be promoted relatively to the intake side end portion Tb.

  In this case, the heat capacity of each insert 5 is varied. As shown in FIG. 8, when the insert 5 is arranged, the insert 5 is arranged from the downstream portion 101 in the vicinity of the tumble plate 100 toward the upstream portion 103 in descending order of the heat capacity of the insert. Here, since the heat capacity is directly proportional to the volume when the material of the insert 5 is the same, the size of the insert 5 is reduced from the downstream portion 101 near the tumble plate 100 toward the upstream portion 103. Specifically, when the volumes of the core pin 5a, the cylinder bore insert 5b, the core pin 5c, and the core pin 5d are denoted as Va, Vb, Vc, and Vd, respectively, the relationship is Vb> Va> Vc> Vd. To do.

  When the insert 5 is made of a different material, the cylinder bore insert 5b, the core pin 5a, the core pin 5c, and the core pin 5d are arranged in this order so that the heat capacity decreases from the downstream portion 101 toward the upstream portion 103. Use a material with a large heat capacity.

  Thus, by reducing the heat capacity of the insert 5 from the downstream portion 101 toward the upstream portion 103, the insert 5 is less likely to be warmed on the downstream portion 101 side and solidification of the molten metal is promoted, and the insert 5 is likely to be warmed on the upstream portion 103 side. Solidification of the molten metal is not promoted. As a result, the molten metal in the vicinity of the downstream portion 101 is first solidified, and the cylinder side end portion Ta of the tumble plate 100 is fixed.

(Change the thermal conductivity of the insert)
By adjusting the thermal conductivity of the insert 5, the solidification of the molten metal in the vicinity of the cylinder side end portion Ta of the tumble plate 100 can be promoted relatively to the intake side end portion Tb.

  In this case, the thermal conductivity of each insert 5 is varied. As shown in FIG. 8, when the insert 5 is disposed, the insert 5 is disposed in order from the downstream portion 101 in the vicinity of the tumble plate 100 toward the upstream portion 103 in descending order of thermal conductivity of the insert. Specifically, the cylinder bore insert 5b, the core pin 5a, the core pin 5c, and the core pin 5d are used in the order of high thermal conductivity.

  By reducing the thermal conductivity of the insert 5 from the downstream portion 101 toward the upstream portion 103 in this way, the heat of the molten metal is easily dissipated by the insert 5 on the downstream portion 101 side, so that solidification of the molten metal is promoted and the upstream portion On the 103 side, since the heat of the molten metal is hardly dissipated by the insert 5, solidification of the molten metal is not promoted. As a result, the molten metal in the vicinity of the downstream portion 101 is first solidified, and the cylinder side end portion Ta of the tumble plate 100 is fixed.

  In addition, since the insert 5 is used as a part of the mold, a certain degree of strength is required. Therefore, for example, as the insert 5, copper, tungsten, iron, or the like can be used. Here, since the thermal conductivity is copper> tungsten> iron, it is preferable to apply to the insert 5 from the downstream portion 101 toward the upstream portion 103 in the descending order of the thermal conductivity. Here, for example, the core pin 5d may be hollow to provide heat insulation.

(Insert temperature control)
FIG. 9 is a schematic diagram showing a cooling structure of a cooling core pin, and FIG. 10 is a schematic configuration diagram of a system for cooling control.

  By actively controlling the temperature of the insert 5, solidification of the molten metal in the vicinity of the cylinder side end portion Ta of the tumble plate 100 can be promoted relatively to the intake side end portion Tb.

  In this case, the core pin 5a, the cylinder bore insert 5b, and the core pin 5c are controlled to a temperature lower than the molten metal so as to cool the molten metal, and the core pin 5d is controlled to a temperature higher than the molten metal so as not to cool the molten metal. . That is, the downstream portion 101 of the tumble plate 100 is cooled and the upstream portion 103 is heated.

  As a structure of the core pin 5a for cooling the molten metal, for example, the structure shown in FIG. 9 can be considered. The core pin 5a has a supply pipe 50 provided in the center and a discharge pipe 51 provided around the supply pipe 50, and is formed in a double piping structure.

  The cooling medium is supplied from the supply pipe 50, and the cooling medium discharged from the tip of the supply pipe 50 is discharged through the discharge pipe 51. When the cooling medium passes through the discharge pipe 51, the surface of the core pin 5a is cooled. Thereby, the molten metal on the surface of the core pin 5a is cooled. Solidification is promoted in the cooled molten metal.

  The pipe 50 for supplying the core pin 5a is connected to an electromagnetic valve 52 shown in FIG. The electromagnetic valve 52 is connected to a control device 53 and can open and close the supply pipe 50 in accordance with an opening / closing instruction of the control device 53.

  The control device 53 is connected to at least one of the molten metal sensor 54 and the pressurization control device 55. Although not shown in FIG. 9, the molten metal sensor 54 is a sensor that is installed in the core pin 5a and detects the arrival of the molten metal due to a temperature change outside the core pin 5a. When the molten metal sensor 54 detects the arrival of the molten metal, it transmits a molten metal arrival signal to the control device 53. With the reception of the molten metal arrival signal, the control device 53 counts a timer and controls the electromagnetic valve 52 to be in an open state for a predetermined time. Thereby, the control apparatus 53 controls so that a cooling medium is sent to the core pin 5a, and adjusts the temperature of the core pin 5a.

  The pressurization control device 55 is a device that performs pressurization control in the mold. The pressurization control means 55 transmits a pressurization start signal to the control device 53 when starting pressurization in the mold. With the reception of the pressurization start signal, the control device 53 counts a timer and controls the electromagnetic valve 52 to be in an open state for a predetermined time. Thereby, the control apparatus 53 controls so that a cooling medium is sent to the core pin 5a, and adjusts the temperature of the core pin 5a.

  In addition to the melt sensor 54 and the pressurization control device 55, a temperature sensor 56 may be connected to the control device 53. The temperature sensor 56 is provided at the tip of the core pin 5 a, detects the temperature near the core pin 5 a, and transmits it to the control device 53. The control device 53 adjusts the temperature of the core pin 5a based on the temperature near the core pin 5a.

  Similarly to the above-described core pin 5a, the cylinder bore insert 5b and the core pin 5c also have a cooling structure. Here, by controlling the temperature of the cooling medium supplied to the core pin 5a, the cylinder bore insert 5b, and the core pin 5c individually, the solidification of the molten metal can be controlled for each position.

  On the other hand, the cored pin 5d has a built-in heater. The heater is connected to the control device 53 shown in FIG. The control device 53 performs control similarly to the electromagnetic valve 52 based on signals from the molten metal sensor 54, the pressurization control device 55, and the temperature sensor 56. That is, the heater is turned on when the electromagnetic valve 52 is opened, and the heater is turned off when the electromagnetic valve 52 is closed. Since the cast pin 5d warms the molten metal in the vicinity thereof by an internal heater, solidification of the molten metal can be prevented or delayed.

  In addition, the casting apparatus of this embodiment is provided with the gate 500 as shown in FIG. The gate 500 is a supply port for supplying high-temperature molten metal into the mold, and is provided at a position away from the cylinder side end portion Ta of the tumble plate 100. Thereby, the molten metal is not directly supplied to the vicinity of the cylinder side end portion Ta of the tumble plate 100, and the solidification of the molten metal in the vicinity of the cylinder side end portion Ta is not prevented.

  As described above, in the present embodiment, the thickness of the tumble plate 100 in the vicinity of the cylinder-side end portion Ta is thinned, and the heat capacity, heat transfer coefficient, and temperature of the insert 5 are controlled, so The solidification promotion effect of the molten metal is relatively enhanced, and conversely, the solidification of the molten metal in the vicinity of the intake side end Tb is delayed. The solidification time of the molten metal in the downstream portion 101, the midstream portion 102, and the upstream portion 103 in the vicinity of the tumble plate 100 was as shown in FIG.

  FIG. 11 is a graph showing the location of the tumble plate 100 and the solidification time of the molten metal in the vicinity thereof. As shown in FIG. 11, when the casting apparatus of the present invention is used, the solidification of the molten metal is controlled along the longitudinal direction of the tumble plate 100 in the order of the downstream portion 101, the midstream portion 102, and the upstream portion 103 around the tumble plate 100. The Since the molten metal in the downstream portion 103 of the tumble plate 100 is solidified first, the cylinder side end portion Ta of the tumble plate 100 is fixed before being affected by the thermal expansion of the tumble plate 100, and the cylinder side end portion Ta with respect to the intake port 14 is fixed. Can be prevented from being displaced.

  The subsequent thermal expansion of the tumble plate 100 is absorbed by the relatively free intake side end portion Tb side where the surrounding molten metal has not yet solidified. That is, the direction in which the tumble plate 100 thermally expands due to the heat of the molten metal can be limited or controlled in one direction from the cylinder side end Ta where the molten metal has solidified toward the intake side end Tb. Since the thermal expansion of the tumble plate 100 is concentrated at the intake side end portion Tb that easily expands, the port core 200 is not pressurized by the cylinder side end portion Ta. For this reason, the port core 200 is not cracked or damaged in a region important for molding the shape of the intake port 14.

  Even if the thermal expansion of the tumble plate 100 is large, the port core 200 is pressurized by the intake side end Tb, so that the crack generated in the port core 200 is induced or induced on the baseboard 201 side. Can do. The burr caused by the cracking of the port core 200 occurs outside the product shape, not inside the cylinder head 10 as a product after the casting is completed. Therefore, the subsequent deburring operation can be easily performed or need not be performed.

  In the present embodiment, the gate 500 for pouring the molten metal is provided at a position away from the vicinity of the cylinder side end portion Ta of the tumble plate 100. Therefore, the vicinity of the cylinder side end portion Ta of the tumble plate 100 is maintained at a high temperature by the heat of the poured molten metal, so that the molten metal does not slow down and can be solidified stably.

  As described above, according to the present embodiment, even if the tumble plate 100 is thermally expanded, the tumble plate 100 is accurately cast in a state where the position of the cylinder side end portion Ta, which is an important position, is maintained. Accordingly, the positional deviation of the tumble plate 100 and the play in the product are sufficiently suppressed to improve the product quality, and further, the occurrence of burrs caused by cracks in the port core 200 is limited. It is possible to facilitate deburring work during processing.

  In addition, the arrangement position of the insert 5 shown in the said FIG. 8 is an illustration to the last, and can be set as what kind of arrangement. Here, the cylinder side end Ta of the tumble plate 100 only needs to solidify the molten metal faster than the intake side end Tb.

  In the insert 5, heat capacity, thermal conductivity, and temperature control can be combined. For example, the heat capacity of the core pin 5a can be increased and the temperature of the core pin 5d can be increased.

  Moreover, although FIG. 8 demonstrated the case where the solidification of a molten metal was adjusted with a some insert, it is not limited to this. Even if a single insert, for example, an insert having a high heat capacity is disposed at the cylinder side end Ta of the tumble plate 100, solidification of the molten metal can be promoted more than the suction side end Tb.

(Modification)
Although the said embodiment demonstrated the case where only the gate 500 was installed in the position away from the cylinder side edge part Ta, it is not limited to this. As shown in FIG. 12, a gate 501 can be provided in addition to the gate 500. FIG. 12 is a cross-sectional view of the cylinder head 10 virtually showing an insert. In the case shown in FIG. 12, the sprue 501 is installed immediately below the tumble plate 100, but by making the size smaller than the spout 500, it is possible to improve the hot water performance while preventing the tumble plate 100 from being heated. .

  Further, as shown in FIG. 12, the punching pin 5d can be omitted as compared with FIG. Even if the cast pin 5d is omitted, the solidification of the molten metal near the cylinder side end Ta is promoted by the cast pins 5a and 5c and the cylinder bore insert 5b. This is because the molten metal is solidified.

  Further, in the above-described embodiment, when the temperature of the insert is controlled, the cast pin 5d including a heater is used in order to make the solidification of the molten metal near the intake side end Tb of the tumble plate 100 slower than the cylinder side end Ta. However, the present invention is not limited to this. For example, instead of the core pin 5d, a solidification adjusting insert that is formed in a hollow shape, prevents diffusion of the surrounding heat, keeps the surrounding temperature, and delays solidification of the molten metal may be installed. it can. Thereby, solidification of the molten metal can be controlled with a simple configuration without controlling the heater.

  Further, in the above embodiment, the cylinder side end portion Ta is exemplified as a portion where the position accuracy of the tumble plate 100 is required. However, in the case where the position accuracy is required in a portion other than the cylinder side end portion Ta, By providing the insert 5 controlled to have a high heat capacity, high thermal conductivity, or low temperature at a position corresponding to the required part, the solidification can be promoted and the solidification can be controlled to be delayed at other parts. For example, in order to increase the position accuracy of the intake side end portion Tb of the tumble plate 100, the insert 5 controlled to have a high heat capacity, high thermal conductivity, or low temperature is provided in the vicinity of the intake side end portion Tb. The insert 5 controlled to have a low heat capacity, low thermal conductivity, or high temperature may be provided in the vicinity of the cylinder side end portion Ta.

  Moreover, although the said embodiment demonstrated the example which casts the tumble board 100 in a cylinder port, it is not limited to this. The present invention can be applied to any casting apparatus that casts and forms a plate-like member that requires a certain position accuracy.

  The present invention can be applied to an application for improving the accuracy of the fixed position of the tumble plate in the intake port of the cylinder head.

It is a schematic sectional drawing which shows the cylinder head of an engine. It is a cross-sectional view perpendicular to the axis of the intake port. It is the schematic which shows the airflow state in a cylinder head. 4A and 4B are a plan view and a side view showing a port core in which a tumble plate is previously installed. It is a schematic sectional drawing which shows the type | mold which shape | molds a port core. It is a top view shown in the state where the type which makes a port core was fractured, and the tumble board was exposed. It is sectional drawing which shows the concept of the state which installed the port core in the casting die which cast-molds a cylinder head. It is a figure which shows an insert virtually to the cylinder head after casting, and Drawing 8 (A) is a top view showing a schematic structure of a cylinder head, and Drawing 8 (B) follows a 8A-8A line of Drawing 8 (A). FIG. It is. It is the schematic which shows the cooling structure of a cooling type core pin. It is a schematic block diagram of the system for cooling control. It is a graph which shows the solidification time of the location of a tumble board and the molten metal of the vicinity. It is sectional drawing of the cylinder head which showed the insert virtually.

Explanation of symbols

5 ... Insert,
10 ... Cylinder head,
14 ... Intake port,
19 ...
53. Control device,
54 ... Molten sensor 55 ... Pressure control device,
56 ... temperature sensor,
100 ... tumble board (partition board),
200: Port core (sand core for molding intake port),
300 ... core type,
400 ... casting mold,
500 ...
501 ...
Ta: cylinder side end,
Tb: Inlet side end.

Claims (13)

A casting apparatus that casts and forms a plate-like member previously set on a sand core such that both side edges protrude outwardly,
A cavity that is larger than the part where the positional accuracy is required is provided so that the thickness of the cast product is thicker at the other part than the part where the positional accuracy of the plate-like member is required. A casting apparatus having a mold to be formed. A casting apparatus that casts and forms a plate-like member that is pre-installed in a sand core such that both side edges protrude outside,
  A larger cavity is formed on the intake side end side than the cylinder side end side so that the thickness of the cast product is thicker on the intake side end side than on the cylinder side end side of the plate-like member. A casting apparatus having a mold to be formed. The mold includes at least one solidification adjusting insert that can be withdrawn from the product after casting;
The casting apparatus according to claim 1, wherein the solidification adjusting insert is disposed in the vicinity of both side edges of the plate-like member and adjusts the solidification of the molten metal. The solidification adjusting insert is disposed on the one end side of the plate-like member, thereby reducing the amount of molten metal flowing into the vicinity of the one end side during casting and promoting the solidification of the molten metal near the one end side. The casting apparatus according to claim 3 . The coagulation adjusting insert, the heat capacity of its own, to claim 3 or claim 4, characterized in that to relatively accelerate from the other end near the molten metal solidification at one end near the molten metal of the plate-like member The casting apparatus described. The coagulation adjusting insert is provided with a plurality, according to claim 5, characterized in that towards the other end from the one end of the plate-like member are disposed in order from the large thermal capacity Casting equipment. The coagulation adjusting insert, the thermal conductivity of its own, according to claim 3 or claim, characterized in that to relatively accelerate from the other end near the molten metal solidification at one end near the molten metal of the plate-like member 4. The casting apparatus according to 4 . The coagulation adjusting insert is provided with a plurality of, from the one end of the plate-like member on the other side, according to claim 7, characterized in that it is arranged in order of large thermal conductivity The casting apparatus described in 1. 5. The casting apparatus according to claim 3, wherein the solidification adjusting insert is adjustable in temperature and is connected to temperature control means for controlling the temperature. The casting apparatus according to any one of claims 1 to 9 , wherein a gate for supplying the molten metal into the mold is provided at a position away from the vicinity of the side edges. The melt plurality of sprue is provided to supply, wherein the sprue away from both side edges, any one of the claims 1-9, characterized in that it is larger than the close sprue The casting apparatus according to item . The casting apparatus according to claim 1, wherein the plate-like member is a partition plate that is cast into a cylinder head after casting and partitions an intake port into a plurality of ports. The casting apparatus according to claim 12 , wherein the partition plate is fixed by solidification of the molten metal first on the downstream side of the upstream side of the intake port.

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