JP4226435B2 - Partition plate for intake port, sand core for forming intake port and cylinder head - Google Patents

Description

  The present invention relates to a partition plate for an intake port, a sand core for forming an intake port, and a cylinder head.

  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 pre-installed in a sand core for forming an intake port for forming an intake port of a cylinder head, and is cast at the time of casting the cylinder head so that the intake port of the cylinder head is made into a plurality of ports. In the partition plate for the intake port that partitions,
Providing a means for promoting the solidification of the molten metal in a part of the end face in the thickness direction at both side edges that are cast into the molten metal ,
The promoting means is composed of at least one of a plurality of convex portions, a plurality of concave portions, a plurality of concave and convex portions, and a plurality of through holes formed on the end faces in the thickness direction at the both side edge portions,
The intake port partition , wherein the promoting means is provided in a portion closer to the cylinder side end than the intake side end, or in a portion closer to the intake side end than the cylinder side end. It is a board.

  According to the present invention, the solidification of the molten metal in the vicinity of a portion where the accelerating means is provided in the end face in the thickness direction at the side edge portion is promoted more than the solidification of the molten metal in the vicinity of the other portion. The position of the partition plate can be regulated, and the product quality can be improved by sufficiently suppressing the position shift of the partition plate and the play in the product. Furthermore, the direction in which the partition plate thermally expands due to the heat of the molten metal can be limited or controlled in one direction, and the occurrence of burrs due to the cracking of the core is limited to deburring in post-processing. The work can be facilitated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, the cylinder head 10 having the partition plate 100 for the intake port 14 which is a premise of the present invention 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”.

  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, FIG. 3 is a schematic view showing an air flow state in the cylinder head 10, and FIG. FIG.

  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 tumble plate 100 is provided in the intake port 14 along the flow direction (white arrow) of intake air flowing from the intake side (outer end side in FIG. 3) toward the cylinder side. As shown in FIGS. 3 and 4, an intake manifold 12 provided with a control valve 18 is connected to the intake side of the tumble plate 100. The intake port 14 is divided into an upper port 14u and a lower port 14d by the tumble 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 first embodiment, when casting the cylinder head 10, the position of the cylinder side end portion Ta of the tumble plate 100 is fixed and the position of the intake side end portion Tb is relatively free. Even if the tumble plate 100 is thermally affected during pouring, it can be absorbed on the intake side end Tb side.

  5A and 5B are a plan view and a side view showing the tumble plate 100 according to the first embodiment.

  As shown in FIGS. 5 (A) and 5 (B), the tumble plate 100 according to the embodiment is preliminarily placed on a later-described intake port molding sand core 200 (see FIG. 6) that forms the intake port 14 of the cylinder head 10. It is installed and cast when the cylinder head 10 is cast to partition the intake port 14 of the cylinder head 10 into a plurality of ports (upper port 14u and lower port 14d). In brief, the tumble plate 100 is provided with an accelerating means 120 for promoting the solidification of the molten metal at a part of the end face 102 in the thickness direction at both side edges Tc to be cast into the molten metal. 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 thickness of the tumble plate 100 is preferably thin so as not to resist the 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 promoting means 120 is limited to a part of the end face 102 in the thickness direction at both side edges Tc, and in the present embodiment, the part is closer to the cylinder side end Ta. The promotion means 120 is composed of a convex portion 121 formed on the end surface 102 in the thickness direction at both side edge portions Tc. The convex portion 121 in the illustrated example has a cylindrical shape. The convex portion 121 forming the promoting means 120 takes into account the positional accuracy required for the tumble plate 100, the thermal expansion amount of the tumble plate 100, and the like, and determines the shape, size, number, installation position, and installation density of the protrusions. Needless to say, it can be changed.

  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.

  For convenience of explanation, a part of the side edge portion Tc of the tumble plate 100 where the accelerating means 120 is provided is also referred to as “coagulation accelerating part a”, and the other part where the accelerating means 120 is not provided is referred to as “smooth part”. Also referred to as “b”.

  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.

  6A and 6B are a plan view and a side view showing the port core 200 in which the tumble plate 100 of the first embodiment is installed in advance. 7 is a schematic cross-sectional view showing a mold 300 for molding the port core 200, and FIG. 8 is a plan view showing the tumble plate 100 exposed by breaking the mold 300 for molding the port core 200. is there. In the following description, the mold 300 for forming the port core 200 is also referred to as “core mold 300”.

  When casting the cylinder head 10, first, the port core 200 shown in FIG. 6 is formed using the core mold 300 shown in FIG. 7.

  The port core 200 is installed in a casting mold 400 for casting the cylinder head 10 (see FIG. 9) 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.

  In the present embodiment, by promoting the solidification of the molten metal by the accelerating means 120 provided at both side edge portions Tc, the solidification promoting portion a at the both side edge portions Tc is firmly fixed. It can be made smaller. Therefore, the notch depth becomes shallow and stress concentration is suppressed from occurring in the notch-shaped part, and the structural strength of the cylinder head 10 can be increased. Furthermore, the thickness of the cylinder head 10 can be reduced, which can contribute to improvement in engine cooling performance and weight reduction.

  And since the promotion means 120 is arrange | positioned in the thickness direction in the both-sides edge part Tc, compared with the form which forms the recessed part which makes a promotion means in the side end surface 101, the casting allowance can be made still smaller, The above-mentioned effects such as increasing the structural strength of the cylinder head 10 can be exhibited more remarkably.

  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.

  As shown in FIG. 8, 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. 7 has shown the baseboard.

  FIG. 9 is a cross-sectional view showing a state where the port core 200 is installed in a casting mold 400 for casting the cylinder head 10.

  As shown in FIG. 9, 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. In addition, the code | symbol "405" in a figure is a core for water jacket shaping | molding. As the casting method, for example, a low pressure casting method (LPDC) is adopted.

  In this state, when a molten metal made of aluminum alloy or other metal is poured into the cavity 404 from the gate (not shown), the cylinder head 10 as shown in FIG. 1 is formed. The tumble plate 100 provided in the port core 200 is thermally expanded by the heat of the molten metal.

  In the present embodiment, the promoting means 120 including the convex portion 121 is provided on a part near the cylinder side end portion Ta of the end surface 102 in the thickness direction at both side edge portions Tc of the tumble plate 100. The promoting means 120 promotes the solidification of the molten metal in the vicinity of the part (solidification promoting part a) provided with the promoting means 120 rather than the solidification of the molten metal in the vicinity of the other part (smoothed part b). This is for regulating the position of the tumble plate 100 with respect to the intake port 14.

  When the port core 200 in which the tumble plate 100 provided with the promoting means 120 is installed in advance is assembled in the casting mold 400 and poured into the cavity 404, the both side edges Tc of the tumble plate 100 are cast. As the molten metal solidifies, the entire side edges Tc are fixed.

  Here, the solidification promoting portion a near the cylinder side end portion Ta of the side edge portions Tc has a larger contact area with the molten metal per unit length due to the presence of the convex portion 121 than the smooth portion b. Yes. For this reason, when both side edge portions Tc of the tumble plate 100 are cast, the molten metal in the vicinity of the solidification promoting part a is relatively rapidly cooled as compared with the molten metal in the vicinity of the smooth part b, and solidification of the molten metal is promoted. . Furthermore, since the passage resistance when the molten metal passes is increased due to the presence of the convex portion 121, the molten metal in the vicinity of the solidification promoting portion a is likely to stay relatively, compared to the molten metal in the vicinity of the smooth portion b. Coagulation of is promoted.

  The action of rapidly quenching the molten metal by the accelerating means 120 and the action of retaining the molten metal combine to promote solidification of the molten metal in the vicinity of the solidification accelerating portion a rather than solidification of the molten metal in the vicinity of the smooth portion b. Thereby, the coagulation promoting part a is fixed to the both side edge parts Tc before the smooth part b, and the position of the tumble plate 100 with respect to the intake port 14 is restricted. Further, the presence of the convex portion 121 increases the resistance when the tumble plate 100 tries to move in the molten metal in a semi-solid state. Also from this point of view, the tumble plate 100 is difficult to move, and displacement of the tumble plate 100 is prevented. In the present embodiment, the side edge portion Tc is fixed at a position near the cylinder side end portion Ta earlier than a portion near the intake side end portion Tb, so that the position of the cylinder side end portion Ta with respect to the intake port 14 is fixed. Misalignment can be prevented.

  Further, since the solidification of the molten metal in the vicinity of the solidification promoting portion a is promoted, even when sand or a resin film or the like remains on both side edges Tc, the airtightness is reliably maintained. Thus, the tumble plate 100 is securely fixed. Thereby, in the cylinder head 10 as a product after the completion of casting, the backlash in the product on the tumble plate 100 can be greatly reduced.

  Further, the coagulation promoting part a of the side edge portions Tc is fixed first, and the smooth part b is fixed relatively later than the coagulation promoting part a. Therefore, the direction in which the tumble plate 100 thermally expands due to the heat of the molten metal is limited or controlled to one direction from the solidification promoting portion a where the molten metal has started to solidify toward the smooth portion b where the molten metal remains unsolidified. It becomes possible. In the present embodiment, since the cylinder side end portion Ta of the tumble plate 100 is fixed first, the direction in which the tumble plate 100 thermally expands can be limited to the direction toward the intake side end portion 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, it is not necessary to perform or perform the subsequent deburring operation easily.

  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.

  FIGS. 10A and 10B are a plan view and a cross-sectional view showing an outline of the intake port 14 in the cylinder head 10 in which a multi-point injection (MPI) type fuel injection device is incorporated, and FIGS. FIG. 4A is a plan view and a cross-sectional view schematically showing an intake port 14 in a cylinder head 10 in which a single-point injection (SPI) type fuel injection device is incorporated.

  In the present embodiment, since the position of the tumble plate 100 with respect to the intake port 14 can be regulated, the cylinder side end portion Ta of the tumble plate 100 can be positioned at a limit position that does not interfere with the fuel injection range or the valve operation range.

  That is, as shown in FIGS. 10A and 10B, in the cylinder head 10 in which the MPI type fuel injection device is incorporated, the cylinder side end portion Ta is positioned at a limit position that does not interfere with the fuel injection range 21. Can be made. Further, as shown in FIGS. 10C and 10D, in the cylinder head 10 in which the SPI type fuel injection device is incorporated, the cylinder side end portion Ta is positioned at a limit position that does not interfere with the valve operating range 22. Can be made. Since the cylinder side end portion Ta is located at a limit position where it does not interfere with the fuel injection range 21 or the valve operation range 22, a desired tumble flow can be reliably formed in the cylinder bore 13 and fuel efficiency can be improved reliably. You can plan.

(Second Embodiment)
FIGS. 11A and 11B are a plan view and a side view showing a port core 200a in which the tumble plate 100a of the second embodiment is installed in advance.

  In the tumble plate 100a of the second embodiment, the portion (coagulation promoting portion a) provided with the accelerating means 120 at both side edge portions Tc is different from the other portion (smooth portion b) at both side edge portions Tc. It is different from the first embodiment in which the casting allowance of both side edges Tc is the same in that the casting allowance is large. Other configurations are the same as those of the first embodiment.

  As the casting allowance, an appropriate dimension can be adopted depending on the wall thickness of the intake port 14 and the thickness of the tumble plate 100a. For example, the casting allowance L1 at the smooth portion b is set to about 2 mm. In this case, the casting allowance L2 in the solidification promoting portion a is set to about 2.5 mm to 3 mm.

  By increasing the casting allowance L2 at the solidification promoting portion a, the contact surface with the cylinder head 10, that is, the main body is increased, and the solidification promoting portion a is more firmly fixed. The positional accuracy of the end portion Ta with respect to the intake port 14 can be further increased. Furthermore, since the area receiving the heat of the hot water is large and the temperature rise of the tumble plate 100a is accelerated, the tumble plate 100a is stretched to a level at which the amount of elongation can be absorbed before the surrounding molten metal solidifies. Become. Thereby, generation | occurrence | production of the crack, damage, etc. of the port core 200a can also be prevented further.

  Note that, as described in the first embodiment, it is possible to make the casting allowance of the side edge portions Tc as small as possible, so the casting allowance is slightly increased as in the second embodiment. Therefore, even if the notch depth is slightly increased, it does not cause a decrease in the structural strength of the cylinder head 10.

(Third embodiment)
FIGS. 12A and 12B are a plan view and a side view showing a port core 200b in which the tumble plate 100b of the third embodiment is installed in advance.

  In the tumble plate 100b of the third embodiment, a portion where the promoting means 120 is provided in that the portion where the promoting means 120 of the end face 102 in the thickness direction at both side edges Tc is provided is closer to the intake side end portion Tb. This is different from the first embodiment in which is set close to the cylinder side end portion Ta. Other configurations are the same as those of the first embodiment.

  Depending on the structure of the intake port 14 and the type of the fuel injection device, it may be required to increase the positional accuracy of the intake side end Tb of the tumble plate 100b. In such a case, as in the third embodiment, the portion (coagulation accelerating portion a) where the promoting means 120 is provided in both side edge portions Tc may be set closer to the intake side end portion Tb.

  In such a configuration, as in the first embodiment, the action of rapidly quenching the molten metal by the accelerating means 120 and the action of retaining the molten metal are combined, so that the solidification of the molten metal in the vicinity of the solidification promoting part a is in the vicinity of the smooth part b. It is promoted more than the solidification of the molten metal. As a result, in the side edge portions Tc, the solidification promoting portion a is fixed before the smooth portion b, and the position of the tumble plate 100b with respect to the intake port 14 is restricted. In the third embodiment, the side edge portion Tc of the tumble plate 100b is fixed at the portion near the intake side end portion Tb before the portion near the cylinder side end portion Ta, so that the intake air to the intake port 14 is sucked. A positional shift of the side end portion Tb can be prevented.

(Fourth embodiment)
FIGS. 13A and 13B are a plan view and a side view showing the port core 200c in which the tumble plate 100c of the fourth embodiment is installed in advance.

  In the tumble plate 100c of the fourth embodiment, convex portions 122 and 123 corresponding to members that promote solidification of the molten metal are provided over the entire longitudinal direction of the end surface 102 in the thickness direction at both side edge portions Tc, In addition, the degree of promoting the solidification of the molten metal by the members 122 and 123 varies along the longitudinal direction, thereby promoting the solidification of the molten metal relatively or substantially to a part of the end face 102 in the thickness direction. 120 is provided. This is different from the first embodiment in which the formation portion of the convex portion 121 is a specific range. Other configurations are the same as those of the first embodiment.

  Depending on the structure of the intake port 14 and the like, it may be required to more firmly fix both side edges Tc of the tumble plate 100c in the entire longitudinal direction. In such a case, the convex portions 122 and 123 may be formed over the entire longitudinal direction of the end surface 102 in the thickness direction as in the fourth embodiment. However, the positional accuracy required for the cylinder side end portion Ta of the tumble plate 100c is different from the positional accuracy required for the intake side end portion Tb, and further, the direction in which the tumble plate 100c is thermally expanded by the heat of the molten metal is the same. It is also necessary to limit or control the direction.

  In the illustrated example, the case where the position accuracy required for the cylinder side end portion Ta is higher than the intake side end portion Tb is taken as an example, and the installation density of the convex portions 122 near the cylinder side end portion Ta is set to “dense”. The installation density of the convex portions 123 near the intake side end portion Tb is “sparse”. The convex part 122 (hereinafter referred to as “dense convex part 122”) having an installation density of “dense” is compared with the convex part 123 (hereinafter referred to as “sparse convex part 123”) having an installation density of “sparse”. In comparison, the effect of rapidly cooling the molten metal and the effect of retaining the molten metal are large. Therefore, even when the convex portions 122 and 123 are formed over the entire longitudinal direction of the end surface 102 in the thickness direction, the promotion means 120 in the present invention can be relatively or substantially changed by changing the installation density of the convex portions 122 and 123. In addition, it is provided on a part of the end face 102 in the thickness direction at both side edge portions Tc. A portion where the dense convex portion 122 is arranged becomes a solidification promoting portion a.

  In such a configuration, the side edges Tc can be more firmly fixed over the entire longitudinal direction by the convex portions 122 and 123 formed over the entire longitudinal direction of the end surface 102 in the thickness direction. Furthermore, the solidification of the molten metal in the vicinity of the dense convex portion 122 that functions as the promoting means 120 is promoted more than the solidification of the molten metal in the vicinity of the loose convex portion 123. As a result, both side edge portions Tc of the tumble plate 100c are fixed before the portion where the sparse convex portion 123 is disposed in the solidification promoting portion a where the dense convex portion 122 is disposed, and the tumble plate 100c with respect to the intake port 14 is fixed. The position is restricted. In the fourth embodiment, the side edge portions Tc of the tumble plate 100c are fixed to the cylinder side with respect to the intake port 14 because the portion near the cylinder side end portion Ta is fixed before the portion near the intake side end portion Tb. The positional shift of the side end portion Ta can be prevented. Further, the direction in which the tumble plate 100c thermally expands can be limited to the direction toward the intake side end Tb, and there is a crack or breakage in an important region for forming the shape of the intake port 14 in the port core 200c. It does not occur.

  The member that promotes the solidification of the molten metal is constituted by a concave portion, a concave and convex portion, a through hole, and the like in addition to the convex portions 122 and 123 described above. In order to vary the degree of promoting the solidification of the molten metal by the member that promotes the solidification of the molten metal along the longitudinal direction, as described above, in addition to the configuration in which the installation density of the convex portions 122 and 123 is changed, the installation density It is also possible to change the size (diameter and height) and the installation position of the convex portions 122 and 123 according to the required degree of positional accuracy while keeping the constant. Further, in order to vary the degree of solidification of the molten metal along the longitudinal direction, in addition to a form that changes only to two degrees, a form that changes stepwise to three or more degrees, or a continuous change Any of the forms can be adopted.

(Fifth to eighth embodiments)
FIGS. 14A and 14B, FIGS. 15A and 15B, FIGS. 16A and B, and FIGS. 17A and 17B are the fifth, sixth, seventh, and eighth, respectively. It is the top view and side view which show the port core 200d-g in which the tumble board 100d-g of embodiment of this was previously installed.

  In 1st Embodiment, although the promotion means 120 comprised from the convex part 121 formed in the end surface 102 of the thickness direction in the both-sides edge part Tc was shown, this invention is not limited to this case. The promoting means 120 can adopt an appropriate structure as long as the solidification of the molten metal is promoted, and may be constituted by a concave portion, a concavo-convex portion or a through-hole formed in the end surface 102 in the thickness direction at both side edge portions Tc. Further, the shape of the accelerating means 120 is not limited to the illustrated cylindrical shape, and an appropriate shape such as a conical shape, a square shape, a pyramid shape, a triangular shape, a rectangular shape, a round hole, a rectangular hole, or a linear shape can be adopted. . The convex portion, the concave portion, the concave and convex portion, and the through hole may be appropriately combined and mixed, or different shapes may be combined and mixed. Furthermore, the processing method of the accelerating means 120 is not limited to press molding, and a known processing method such as laser processing, knurling, drilling, or cutting can be employed.

  Specifically, the promoting means 120 can be structured as in the fifth to eighth embodiments.

  In the fifth embodiment, the end face 102 in the thickness direction is subjected to laser processing to form a concave portion 124 having a substantially conical shape (FIGS. 14A and 14B).

  In the sixth embodiment, the end face 102 in the thickness direction is knurled to form the cross hatched uneven portion 125 over the entire width of the casting allowance (FIGS. 15A and 15B).

  In the seventh embodiment, the end face 102 in the thickness direction is drilled to form a through hole 126 formed of a round hole (FIGS. 16A and 16B).

  In the eighth embodiment, the end surface 102 in the thickness direction is subjected to laser processing or cutting to form an oblique linear recess 127 (FIGS. 17A and 17B).

(Ninth embodiment)
18A and 18B are plan views showing tumble plates 100h and 100i of the ninth embodiment.

  As described above, the port core 200 is formed by blowing core sand in a state where the tumble plate 100 is previously placed on the core mold 300. In consideration of the flow behavior of the molten metal, the shape of the left and right side edge portions Tc of the tumble plate 100, the allowance for casting, and the like may be varied. When the tumble plate 100 has a distinction between the front and the back, when forming the port core 200, it is necessary to place the tumble plate 100 on the core mold 300 so that the front and back of the tumble plate 100 are in the correct orientation. In such a case, as in the ninth embodiment, in order to prevent a setting error when the tumble plates 100h and 100i are placed on the core mold 300, it is preferable to provide a so-called “pokka”. . Specifically, a notch 128 is provided as an anti-poker (see FIG. 18A), or the arrangement state of the convex portions 121 forming the promotion means 120 is asymmetrical at the left and right side edge portions Tc (see FIG. 18 (B)).

(Tenth embodiment)
FIG. 19 is a plan view and a side view showing the port core 200j in which the tumble plate 100j of the tenth embodiment is installed in advance.

  The tumble plate 100j according to the tenth embodiment is further provided with an accelerating means only on the end face 102 in the thickness direction in that another accelerating means 110 for accelerating the solidification of the molten metal is further provided on the side end face 101 at both side edges Tc. This is different from the first embodiment in which 120 is provided.

  In consideration of the change in the thickness of the cylinder head 10 and the avoidance of stress concentration, the promotion means 120 provided on the end face 102 in the thickness direction at the side edge Tc and other promotion means provided on the side end face 101 at the side edge Tc. 110 may be an effective means in combination. In such a case, as in the tenth embodiment, the facilitating means 120 is provided on the end surface 102 in the thickness direction at the side edge Tc, while the other facilitating means 110 is provided on the side end surface 101 at the side edge Tc. Provide. The other promotion means 110 can be comprised from at least 1 among the recessed part 111 formed in the side end surface 101 in the both-sides edge part Tc, a convex part, and an uneven | corrugated | grooved part.

  For example, the other accelerating means 110 constituted by the concave portion 111 formed on the side end face 101 is combined with the action of rapidly cooling the molten metal and the action of retaining the molten metal in the same manner as the accelerating means 120 constituted by the convex portion 121. A function of accelerating solidification of the molten metal in the vicinity of the portion a than that of the molten metal in the vicinity of the smooth portion b is exhibited.

  When the other promoting means 110 is provided on the side end face 101, the casting allowance in this part is slightly larger than the casting allowance in the part in which the promoting means 120 is provided on the end face 102 in the thickness direction. The depth is slightly deeper. For this reason, it is not preferable to apply the method of providing the other promoting means 110 on the side end face 101 to a part where stress concentration is to be avoided or a part where the cylinder head 10 is thin. However, in the thick wall portion, even if the notch depth is slightly deep, it does not cause a decrease in the structural strength of the cylinder head 10, but rather, the contact area with the molten metal increases and the wall thickness increases. There is an effect of promoting the cooling of the molten metal in a thick part.

  In the present embodiment, in consideration of the above points, the combined use of the promoting means 120 provided on the end face 102 in the thickness direction and the other promoting means 110 provided on the side end face 101 is defined as follows. First, near the cylinder side end Ta on the downstream side where the requirement of positioning accuracy is relatively high, the cylinder head 10 is thick, and therefore, the side end face 101 is provided with another promoting means 110 including the recess 111. Further, in the vicinity of the head bolt 129 where stress concentration is desired to be avoided, the facilitating means 120 composed of the convex portions 121 is provided on the end face 102 in the thickness direction so that the mutual interval is narrow (installation density “dense”). Further, since the cylinder head 10 is thin at the upstream intake side end portion Tb where the positioning accuracy requirement is relatively low, the accelerating means 120 formed of the convex portions 121 on the end surface 102 in the thickness direction is spaced from each other. Is widened (installation density is "sparse"). With this configuration, it is possible to easily cope with the change in the thickness of the cylinder head 10 and the avoidance of stress concentration.

  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. FIG. 4 is a schematic plan view of FIG. 3. 5A and 5B are a plan view and a side view showing the tumble plate according to the first embodiment. FIGS. 6A and 6B are a plan view and a side view showing a port core in which the tumble plate of the first embodiment is installed in advance. 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 state which installed the port core in the casting die which cast-molds a cylinder head. FIGS. 10A and 10B are a plan view and a cross-sectional view showing an outline of an intake port in a cylinder head in which a multi-point injection (MPI) type fuel injection device is incorporated, and FIGS. FIG. 2 is a plan view and a cross-sectional view showing an outline of an intake port in a cylinder head in which a single point injection (SPI) type fuel injection device is incorporated. FIGS. 11A and 11B are a plan view and a side view showing an intake port molding sand core in which the tumble plate of the second embodiment is installed in advance. FIGS. 12A and 12B are a plan view and a side view showing a port core in which the tumble plate of the third embodiment is installed in advance. 13A and 13B are a plan view and a side view showing a port core in which the tumble plate of the fourth embodiment is installed in advance. FIGS. 14A and 14B are a plan view and a side view showing a port core in which the tumble plate of the fifth embodiment is installed in advance. FIGS. 15A and 15B are a plan view and a side view showing a port core in which the tumble plate of the sixth embodiment is installed in advance. FIGS. 16A and 16B are a plan view and a side view showing a port core in which the tumble plate of the seventh embodiment is installed in advance. FIGS. 17A and 17B are a plan view and a side view showing a port core in which the tumble plate of the eighth embodiment is installed in advance. It is a top view which shows the tumble board of 9th Embodiment. 19A and 19B are a plan view and a side view showing a port core in which the tumble plate of the tenth embodiment is installed in advance.

Explanation of symbols

10 cylinder head,
14 intake port,
21 Fuel injection range,
22 Valve operating range,
100 tumble board (partition board),
101 side end face,
102 end face in thickness direction 110 other promotion means,
111 recess (other facilitating means),
120 facilitating means,
121 convex part (promotion means),
122, 123 convex parts (members that promote solidification of the molten metal),
200 port core (sand core for molding intake port),
300 core type,
400 casting mold,
Ta cylinder side end,
Tb Inlet side end,
Tc Side edge.

Claims (9)

In an intake port partition plate that is pre-installed in an intake port molding sand core that forms an intake port of a cylinder head, and is encased during casting of the cylinder head, and partitions the intake port of the cylinder head into a plurality of ports.
Providing a means for promoting the solidification of the molten metal in a part of the end face in the thickness direction at both side edges that are cast into the molten metal ,
The promoting means is composed of at least one of a plurality of convex portions, a plurality of concave portions, a plurality of concave and convex portions, and a plurality of through holes formed on the end faces in the thickness direction at the both side edge portions,
The intake port partition , wherein the promoting means is provided in a portion closer to the cylinder side end than the intake side end, or in a portion closer to the intake side end than the cylinder side end. Board. In an intake port partition plate that is pre-installed in an intake port molding sand core that forms an intake port of a cylinder head, and is encased during casting of the cylinder head, and partitions the intake port of the cylinder head into a plurality of ports.
Providing a means for promoting the solidification of the molten metal in a part of the end face in the thickness direction at both side edges that are cast into the molten metal,
The partition plate for an intake port , wherein the promotion means is provided in a portion closer to the cylinder side end than the intake side end . 3. The intake port for an intake port according to claim 1, wherein a portion of the side edge portion where the promoting means is provided has a larger casting allowance than other portions of the side edge portion. Partition plate. In an intake port partition plate that is pre-installed in an intake port molding sand core that forms an intake port of a cylinder head, and is encased during casting of the cylinder head, and partitions the intake port of the cylinder head into a plurality of ports.
A member for promoting the solidification of the molten metal is provided on each of the end portions in the thickness direction at both side edges to be cast into the molten metal and the portions near the cylinder side end and the intake side end,
By varying the degree of promoting the solidification of the molten metal by the member in the portion near the cylinder side end portion and the degree of promoting the solidification of the molten metal by the member in the portion near the intake side end portion, the cylinder side A partition plate for an intake port , characterized in that an accelerating means for relatively promoting the solidification of the molten metal is provided in a portion near the end portion or a portion near the intake side end portion . 3. The intake port partition plate according to claim 1, further comprising another accelerating means for accelerating solidification of the molten metal on a side end surface of the both side edge portions . 4. The said other promotion means is comprised from at least 1 among the several recessed part formed in the side end surface in the said both-sides edge part, several convex part, and several uneven | corrugated | grooved part. partition plate for the intake port.   In the intake port molding sand core that is installed in the casting mold for casting the cylinder head and forms the intake port of the cylinder head,
  The intake port partition plate according to any one of claims 1 to 6, wherein both sides of the partition plate project outside so as to be cast into molten metal, and are installed in advance. Sand core for molding.   The partition plate for an intake port according to any one of claims 1 to 6, wherein both side edges are cast into the molten metal and installed in the intake port,
  The position of the partition plate with respect to the intake port is promoted by the promoting means of the partition plate by promoting the solidification of the molten metal in the vicinity of the part where the promoting means is provided than in the vicinity of the other part. Cylinder head characterized by regulating   The cylinder head according to claim 8, wherein the cylinder side end portion of the partition plate is positioned at a limit position that does not interfere with a fuel injection range or a valve operation range.

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