JP2005120997A - Partition plate for intake port, sand core for forming intake port and cylinder head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the product quality by remarkably improving looseness of a partition plate in a product. <P>SOLUTION: This partition plate 100 (tumble plate) for the intake port 14 is previously installed in an intake port forming sand core (port core) 200 for forming the intake port of the cylinder head, and inserted at the time of cast-forming the cylinder head to partition the intake port into a plurality of ports. In the partition plate, both side edge parts Tc inserted in molten metal are subjected to surface treatment, so that both side edge parts are roughened to have a larger surface roughness than the surface roughness of a partition part 103 partitioning the inside of the intake port. <P>COPYRIGHT: (C)2005,JPO&NCIPI

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”.

  When casting the cylinder head, it is common to install a metal partition plate in the sand core for intake port molding and cast and form both side edges of the partition plate protruding from the core. . In the cylinder head after casting, both side edges of the partition plate are not welded to the cylinder head. This is because, when welded, the partition plate may be fatigued due to repeated thermal shock and vibration received when used as an engine. Thus, since the cast-in part of the partition plate, that is, both side edges are not welded to the cylinder head, in the cylinder head as a product after the casting is completed, there is a possibility that the partition plate may be loose in the product.

Moreover, a press product may be used for a partition plate from a cost viewpoint. The press product uses a plate material having a relatively small surface roughness in order to properly perform the press work, and the surface is soiled by a lubricating oil film during the press work. When the partition plate made of such a press product is cast and formed, the grip force of the partition plate against the cylinder head is low, and the partition plate is likely to be loose in the product.
JP 2001-193469 A

  The present invention has been made in view of the above circumstances, and an object thereof is to greatly improve the play in the product of the partition plate to improve the product quality.

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,
Surface treatment is performed on both side edge portions cast into the molten metal, and the both side edge portions are roughened to a surface roughness larger than the surface roughness of the partition portion partitioning the inside of the intake port. It is a partition plate for intake ports.

  According to the present invention, by applying a surface treatment to both side edges that are cast into the molten metal, dirt remaining on the surfaces of both side edges is removed and the surface roughness of both side edges is increased. Therefore, even when the both side edges of the partition plate are not welded to the cylinder head, the grip force of the partition plate against the intake ports on both side edges can be increased, greatly improving the play in the product. Product quality can be improved.

  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.

  In the cylinder head 10 as a product after the completion of casting, it is also important that the tumble plate 100 has no play in the product. This is because when used as an engine, the tumble flow is disturbed and sound vibrations are caused. If both side edges Tc of the tumble plate 100 can be welded to the cylinder head 10, rattling of the tumble plate 100 can be avoided, but if it is welded, a new problem of causing fatigue failure of the tumble plate 100 occurs. Therefore, the side edge portions Tc cannot be welded to the cylinder head 10. From the viewpoint of cost, a press product may be used for the tumble plate. However, a lubricating oil film or other dirt in the pressing process may adhere to both side edges Tc. It becomes a factor which promotes the clearance gap between the part Tc and the cylinder head 10 wall part. For this reason, rattling of the tumble plate occurs in the longitudinal direction and the vertical direction, and a gap of about 1/10 mm may occur.

  Therefore, in the first embodiment, when casting the cylinder head 10, both side edges Tc are roughened to remove the dirt on the surface at the same time, and both side edges Tc are welded to the cylinder head. Even if the structure is not made, the grip force of the tumble plate 100 can be increased.

  5A, 5B, and 5C are a plan view, a side view, and a schematic enlarged view of the side edge portion Tc showing the tumble plate 100 according to the first embodiment.

  The tumble plate 100 according to this embodiment is installed in advance in a later-described intake port molding sand core 200 (see FIG. 7) that forms the intake port 14 of the cylinder head 10, and is cast when the cylinder head 10 is cast. Rarely, the intake port 14 of the cylinder head 10 is partitioned into a plurality of ports (upper port 14u and lower port 14d). In brief, as shown in FIG. 5C, the tumble plate 100 performs surface treatment on both side edges Tc encased in the molten metal to partition the side edges Tc into the intake port 14. The surface roughness of the partition 103 is larger than the surface roughness. The roughening by the surface treatment is performed on the side end face 101 and the end face 102 in the thickness direction at the side edges Tc. In the following description, the intake port molding sand core 200 on which the tumble plate 100 is preliminarily installed is also referred to as “port core 200”, and the roughened portion is referred to as “roughened portion 130”. Is also referred to.

  More specifically, as shown in FIGS. 5A and 5B, the tumble plate 100 has a thin, substantially rectangular shape, and both side edge portions Tc that are to be cast in the molten metal when the cylinder head 10 is cast. And an intake side end portion Tb that is continuous with both side edge portions Tc and is disposed upstream of the intake air flow in the intake port 14, and is continuous with both side edge portions Tc and downstream of the intake air flow. And a cylinder side end Ta to be arranged. 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.

  By performing surface treatment on both side edge portions Tc, both side edge portions Tc are roughened to form a roughened portion 130, but the surface roughness of both side edge portions Tc is larger than the surface roughness of the partition portion 103. It is preferable to increase the size (see FIG. 5C). This is to prevent rattling of the tumble plate 100 while preventing disturbance of the tumble flow.

  The surface treatment method for roughening the side edge portions Tc is not particularly limited, and examples thereof include mechanical blast treatment and chemical corrosion treatment. The blast treatment includes sand shot blast and steel shot blast, and the corrosion treatment includes corrosion treatment with sodium hydroxide.

  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. Although there may be a case where a lubricating oil film or other dirt in the pressing process adheres to both side edges Tc, in this embodiment, the surface treatment on the tumble plate 100 performed after the pressing process results in the side edges Tc. Surface contamination will be removed at the same time. Since the surface contamination is eliminated, even if the press product is used for the tumble plate 100, the factor that promotes the gap between the side edge portions Tc and the cylinder head 10 is eliminated.

  6 (A) and 6 (B) are diagrams for explaining in which process the surface treatment is performed, and FIG. 6 (A) shows the side edge Tc before the port core 200 is formed. FIG. 6B shows a case where the surface treatment is performed on the side edge portions Tc after the port core 200 is formed.

  The surface treatment for roughening the side edges Tc is performed before molding the port core 200 as shown in FIG. 6 (A), or as shown in FIG. 6 (B). Or can be carried out after molding.

  In any case, the surface treatment is preferably performed by providing the partition 103 with the masking means 131. The small surface roughness, that is, smoothness of the partition portion 103 is not impaired, and the disturbance of the tumble flow can be prevented, and the surface roughness of only the side edge portions Tc that are the cast-in portions is increased to reduce the backlash of the tumble plate 100. This is because it can be suppressed.

  Here, the masking means 131 can be composed of the masking material 132 or the core sand 210 forming the port core 200.

  That is, as shown in FIG. 6 (A), when the surface treatment is performed before molding the port core 200, the partition 103 is masked by the masking material 132 as the masking means 131, and both side edges are formed. Surface treatment can be performed only on Tc. For example, when the shot blasting process is performed in a state where the masking material 132 is disposed in the partition portion 103 and both side edge portions Tc are exposed, the partition portion 103 secures the surface roughness required for performance, The surface roughness of Tc can be increased. If surface treatment such as sand shot blasting or steel shot blasting is applied to the entire tumble plate 100, the surface roughness of the partition portion 103 becomes too rough and the tumble flow may be disturbed. It is effective to partially treat the surface with 132.

  In addition, as shown in FIG. 6B, when the surface treatment is performed after the port core 200 is molded, the surface treatment is applied only to both side edges Tc projecting outward from the port core 200 in the first place. Cannot be applied. For this reason, the core sand 210 forming the port core 200 is used as the masking means 131. Even in this case, the partition 103 can be masked by the core sand 210 as the masking means 131, and the surface treatment can be performed only on the side edge portions Tc. For example, when a corrosive treatment in which a corrosive solution such as a sodium hydroxide solution is applied to both side edges Tc with a brush or the like, the surface of the side edges Tc is secured in the partition 103 while ensuring the surface roughness required for performance. The roughness can be increased. In the surface treatment method in this case, the amount of the corrosive liquid used for the surface treatment can be reduced, and furthermore, the corrosion reaction at both side edges Tc is promoted by the residual heat at the time of molding the port core 200. There is also an advantage that the time required for the process can be shortened.

  FIGS. 7A and 7B 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. 8 is a schematic cross-sectional view showing a mold 300 for molding the port core 200. FIG. 9 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. 7 is formed using the core mold 300 shown in FIG. 8.

  The port core 200 is installed in a casting mold 400 for casting the cylinder head 10 (see FIG. 10) to form the intake port 14 of the cylinder head 10. The port core 200 is installed in advance so that the above-described tumble plate 100 protrudes to the outside so that both side edges Tc, which are roughened portions 130, are cast into 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.

  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. 9, 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 formed in the core mold 300 is formed 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. 8 has shown the baseboard.

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

  As shown in FIG. 10, the port core 200 is incorporated into 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 both side edges Tc of the tumble plate 100 are cast and the molten metal is solidified. Then, the entire side edges Tc are fixed, and the cylinder head 10 as shown in FIG. 1 is formed.

  In the present embodiment, by applying a surface treatment to both side edge portions Tc cast into the molten metal of the tumble plate 100, the side surface edge portions Tc of the tumble plate 100, which is a pressed product, removes dirt remaining on the surface. In addition, the roughened portion 130 has a surface roughness larger than the surface roughness of the partition portion 103. For this reason, even when both side edges Tc of the tumble plate 100 are not welded to the cylinder head 10, the roughened side edges Tc have a large number of minute meshing portions with the solidified molten metal. As a result, the grip force of the tumble plate 100 is increased, and the tumble plate 100 is securely fixed. Thereby, in the cylinder head 10 as a product after the completion of casting, the play of the tumble plate 100 with respect to the intake port 14 is suppressed.

  As described above, according to the present embodiment, even if the both side edge portions Tc of the tumble plate 100 are not welded to the cylinder head 10, they are cast with high accuracy. Therefore, the play in the product of the tumble plate 100 can be greatly improved and the product quality can be improved.

  FIG. 11A shows the surface roughness when the steel shot blasting, sand shot blasting and sodium hydroxide corrosion are performed as the surface treatment for roughening the side edges Tc. The graph shown together with the surface roughness, FIG. 11 (B), shows the backlash of the tumble plate 100 when corrosion by steel shot blast, sand shot blast, and sodium hydroxide is performed as the surface treatment for roughening the side edges Tc. It is a graph which shows a sticking incidence rate with the looseness incidence rate of the tumble board 100 with no processing, ie, a press product. In FIG. 11A, the surface roughness is indicated by arithmetic average roughness Ra (μm).

  As shown in FIG. 11A, the surface roughness varies depending on the processing method, and it can be seen that steel shot blasting is an effective means for roughening. As shown in FIG. 11 (B), the backlash occurrence rate of the tumble plate 100 depends on the surface roughness of the side edges Tc, and the surface roughness is more effective for the backlash of the tumble plate 100. It can be seen that this can be prevented. In any surface treatment method, the backlash is greatly reduced with respect to the pressed product. In particular, when surface treatment was performed with steel shot blasting, no play was observed.

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

  In the tumble plate 100b of the second embodiment, the side edges Tc further include an accelerating member 133 that promotes solidification of the molten metal, and the surface of the accelerating member 133 is roughened. This is different from the first embodiment. Other configurations are the same as those of the first embodiment.

  As described above, the position of the cylinder side end portion Ta of the tumble plate 100b is an important position because it greatly affects the state of occurrence of the tumble flow.

  In the second embodiment, when casting the cylinder head 10, the position of the cylinder side end portion Ta of the tumble plate 100b is fixed and the position of the intake side end portion Tb is relatively free. Even if the tumble plate 100b is thermally affected during hot water, the tumble plate 100b can absorb this on the intake side end Tb side.

  The promotion member 133 is limited to a part of the side end face 101 at the side edge Tc. In the present embodiment, the part is close to the cylinder side end Ta. The promotion member 133 is configured by a recess 134 formed in the side end surface 101 at both side edge portions Tc. The inner surface of the concave portion 134 is surface-treated to form a roughened portion 130. The concave portion 134 in the illustrated example has a semicircular arc shape. The concave portion 134 forming the promoting member 133 can change the size, number, installation position, and installation density of the concave shape in consideration of the positional accuracy required for the tumble plate 100b, the thermal expansion amount of the tumble plate 100b, and the like. Needless to say.

  For convenience of explanation, a part of the side edge portion Tc of the tumble plate 100b where the promoting member 133 is provided is also referred to as “coagulation promoting part a”, and the other part where the promoting member 133 is not provided is “not installed”. Also referred to as “part b”.

  The accelerating member 133 promotes the solidification of the molten metal in the vicinity of the portion where the accelerating member 133 is provided (solidification accelerating portion a) rather than the solidification of the molten metal in the vicinity of the other portion (non-installed portion b). This is for regulating the position of the tumble plate 100b with respect to the intake port.

  When the port core 200b in which the tumble plate 100b provided with such a promotion member 133 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 100b 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 both side edge portions Tc has a larger contact area with the molten metal per unit length due to the presence of the concave portion 134 than the non-installation portion b. Yes. For this reason, when both side edges Tc of the tumble plate 100b are cast, the molten metal in the vicinity of the solidification promoting portion a is relatively rapidly cooled as compared with the molten metal in the vicinity of the non-installed portion b, and the solidification of the molten metal is promoted. The Furthermore, since the passage resistance when the molten metal passes increases due to the presence of the concave portion 134, the molten metal in the vicinity of the solidification promoting portion a is relatively likely to stay compared to the molten metal in the vicinity of the non-installed portion b. Coagulation of is promoted.

  The action of rapidly quenching the molten metal by the accelerating member 133 and the action of retaining the molten metal combine to promote the solidification of the molten metal in the vicinity of the solidification accelerating portion a rather than the solidification of the molten metal in the vicinity of the non-installed portion b. As a result, the side edge portions Tc have their solidification promoting portions a fixed prior to the non-installation portions b, and the position of the tumble plate 100b with respect to the intake port 14 is restricted. Further, due to the presence of the recess 134, the resistance when the tumble plate 100b tries to move in the molten metal in a semi-solid state is also increased. Also from this point of view, the tumble plate 100b is difficult to move, and displacement of the tumble plate 100b 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, the solidification of the molten metal in the vicinity of the solidification promoting portion a is promoted, and further, the facilitating member 133 is formed with the roughened portion 130 while removing the dirt remaining on the surface thereof. Even in a state where the edge portion Tc is not welded to the cylinder head 10, not only the side end surface 101 and the end surface 102 in the thickness direction of both side edge portions Tc but also the solidified molten member 133 is solidified. As a result of the formation of many minute meshing portions between the tumble plates 100, the gripping force of the tumble plate 100 is further increased, and the tumble plate 100 is more securely fixed. Thereby, in the cylinder head 10 as a product after the completion of casting, the play of the tumble plate 100b with respect to the intake port 14 is further suppressed.

  Furthermore, the coagulation promoting part a of the side edge portions Tc is fixed first, and the non-installation part b is fixed relatively later than the coagulation promoting part a. For this reason, the direction in which the tumble plate 100b thermally expands due to the heat of the molten metal is limited or controlled in one direction from the solidification promoting part a where the molten metal starts to solidify toward the non-installed part b where the molten metal remains unsolidified. Is possible. In this embodiment, since the cylinder side end portion Ta of the tumble plate 100b is fixed first, the direction of thermal expansion of the tumble plate 100b can be limited to the direction toward the intake side end portion Tb. Since the thermal expansion of the tumble plate 100b is concentrated at the intake side end Tb that is easy to expand, the port core 200b is not pressurized by the cylinder side end Ta. For this reason, the port core 200b is not cracked or damaged in a region important for shaping the shape of the intake port 14.

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

  As described above, according to the second embodiment, even if the tumble plate 100b is thermally expanded, the tumble plate 100b is accurately cast in a state where the position of the cylinder side end portion Ta that is an important position is maintained. Become. Therefore, in addition to the effect of preventing rattling of the tumble plate 100b as in the first embodiment, the positional accuracy of the tumble plate 100b and the bending of the port core 200b can be improved comprehensively.

  Depending on the structure of the intake port 14 and the type of the fuel injection device, it may be required to improve the positional accuracy of the intake side end portion Tb of the tumble plate 100. In such a case, if the accelerating member 133 that promotes solidification of the molten metal is provided near the intake side end portion Tb, the positional accuracy of the intake side end portion Tb can be increased. Further, the promoting member 133 can be provided on the end face 102 in the thickness direction at the side edge portions Tc. Furthermore, the promotion member 133 can adopt an appropriate structure and shape as long as the solidification of the molten metal is promoted.

(Other variations)
When the gap between the side edge portion Tc and the cylinder head 10 wall portion, which causes the play of the tumble plate 100, occurs in a specific range along the longitudinal direction of the side edge portion Tc, Only a part of the side edge portion Tc corresponding to the specific range may be roughened. Moreover, while roughening the whole side edge part Tc, you may make the surface roughness of a part corresponding to the said specific range further rough. In order to vary the surface roughness along the longitudinal direction, the time for projecting shots and the time for leaving the applied corrosive solution, that is, the surface treatment time, can be varied along the longitudinal direction, the shot diameter, the projected amount, and the corrosion. What is necessary is just to change liquid concentration etc. along a longitudinal direction. In addition, when changing the surface roughness along the longitudinal direction, in addition to a mode in which the surface roughness is changed to only two surface roughnesses, a mode in which the surface roughness is gradually changed to three or more surface roughnesses, or a continuous change. Any of the forms can be adopted.

  The present invention can be applied to an application for improving the backlash of the tumble plate at 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, 5B, and 5C are a plan view, a side view, and a schematic enlarged view of a side edge portion showing the tumble plate according to the first embodiment. 6 (A) and 6 (B) are diagrams for explaining in which process the surface treatment is performed, and FIG. 6 (A) shows the surface with respect to both side edges before molding the port core. FIG. 6B shows a case where the surface treatment is performed on both side edges after forming the port core. FIGS. 7A and 7B 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. FIG. 11 (A) shows the surface roughness when steel shot blasting, sand shot blasting and corrosion with sodium hydroxide are performed as the surface treatment for roughening the both side edges. The graph shown together with the roughness, FIG. 11B, shows the occurrence rate of rattling of the tumble plate when steel shot blasting, sand shot blasting, and sodium hydroxide corrosion are performed as the surface treatment for roughening both side edges. Is a graph showing the wobbling occurrence rate of the tumble plate that is not processed, that is, a pressed product. FIGS. 12A and 12B are a plan view and a side view showing a port core in which the tumble plate of the second embodiment is installed in advance.

Explanation of symbols

10 cylinder head,
14 intake port,
100 tumble board (partition board),
103 partition,
130 roughening section,
131 masking means;
132 Masking material (masking means),
133 Accelerating member that promotes solidification of the molten metal,
134 recess (promotion member),
200 port core (sand core for molding intake port),
210 Core sand (masking means) molding port core,
300 core type,
400 casting mold,
Ta cylinder side end,
Tb Inlet side end,
Tc Side edge.

Claims (5)

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 cast when the cylinder head is cast, and partitions the intake port of the cylinder head into a plurality of ports.
Surface treatment is performed on both side edge portions cast into the molten metal, and the both side edge portions are roughened to a surface roughness larger than the surface roughness of the partition portion partitioning the inside of the intake port. Partition plate for intake port. The surface treatment is performed by providing a masking means on the partition part,
2. The intake port partition plate according to claim 1, wherein the masking means is formed of a masking material or core sand forming the intake port molding sand core. 3.   2. The intake port partition plate according to claim 1, wherein the side edges further include a promoting member that promotes solidification of the molten metal, and a surface of the promoting member is roughened. 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 3, wherein both sides of the partition plate protrude outside so as to be cast in 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 3, wherein both side edges are cast into the molten metal and installed in the intake port,
The cylinder head is characterized in that the backlash of the partition plate with respect to the intake port is suppressed by the surface roughness of the side edges.

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