JP2004211683A - Air intake device for internal combustion engine and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate deburring work in after-machining by generating burring at limited positions resulting from the crack of a core due to a thermal expansion difference between the core for forming an air intake port and a partition plate when casting the partition plate 6 for partitioning the air intake port 3 of a cylinder head into upper and lower parts, at its side edge 6a into the inner wall of the air intake port 3 of the cylinder head. <P>SOLUTION: A portion 21 located inside the cross section of an air intake port passage, out of the end of the partition plate 6 on the side of a head end face 5, is located inside of the head end face 5. A portion 22 located outside the cross section of the air intake port passage and adapted to be cast into the inner wall of the air intake port 3 of the cylinder head is protruded outside of the head end face 5 and formed flush with the head end face 5 in after-machining. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an intake device for an internal combustion engine in which an intake port in a cylinder head is partitioned by a partition plate into a pair of divided intake ports, and a method of manufacturing the intake device.

Patent Document 1 discloses an intake passage structure in which an intake port in a cylinder head is divided into a pair of divided intake ports by a partition plate in order to enhance a tumble flow (longitudinal vortex) of intake air introduced into a cylinder of an internal combustion engine. It is known.
Further, in Patent Literature 1, when a partition plate is cast at the time of casting of a cylinder head, the partition plate has a corrugated plate shape as a measure against the deformation of the partition plate due to thermal expansion.
JP 2001-193469 A (especially paragraphs 0020 and 0022)

However, in a corrugated partition plate as disclosed in Patent Document 1, thermal expansion in the radial direction of the intake port can be absorbed, but thermal expansion in the axial direction of the intake port cannot be absorbed.
For this reason, when the partition plate is set and cast into the core for forming the intake port when casting the cylinder head, the core is broken (broken) due to the difference in thermal expansion between the partition plate and the core (cast sand). Hot water (aluminum) flows into the cracked part, causing burrs (cast burrs). Depending on the location of the burrs, deburring work in post-processing is extremely troublesome. There was a problem of becoming.

  In view of such conventional problems, the present invention restricts the location of burrs caused by cracks in the core due to the difference in thermal expansion between the partition plate and the core, and performs deburring work in post-processing. The purpose is to facilitate

  For this reason, in the present invention, of the end of the partition plate on the side of the intake port opening surface of the cylinder head, the portion located in the cross section of the intake port passage is located inside the intake port opening surface of the cylinder head, A portion located outside the port passage cross section and cast into the intake port inner wall portion of the cylinder head is formed so as to protrude outward from the intake port opening surface of the cylinder head and formed flush with the intake port opening surface by post-processing. I do.

  According to the present invention, according to the above configuration, the intake port opening of the cylinder head on the side of the end portion of the partition plate that is located outside the cross section of the intake port passage and cast into the intake port inner wall of the cylinder head. Burrs are generated at portions protruding outside the surface. Therefore, burrs are generated outside the product, and when finishing the intake port opening surface of the cylinder head after casting, burrs can be removed together by cutting off the protruding portions.

  In addition, among the ends of the partition plate, the portion located in the cross section of the intake port passage of the cylinder head is easily deformed because it is not directly supported, but is located inside the intake port opening surface of the cylinder head, Since it is not a target of resection, the resection operation is only a part and can be easily performed.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of a cylinder head of an internal combustion engine showing an embodiment of the present invention, FIG. 2 is a plan view of an intake port taken along line AA of FIG. 1, and FIG. FIG. 3 is a view of an intake port opening surface of a head side wall.
An intake port 3 and an exhaust port 4 are formed in a cylinder head 1 made of an aluminum alloy with respect to a cylinder 2.

The intake port 3 is a siamese type that branches into two on the downstream side, opens into the cylinder 2 via intake valves (not shown), and gathers on the upstream side. The upstream gathering portion has a flat passage section that is long in the lateral direction, and is open to the side wall (the intake port opening surface 5) of the cylinder head 1.
The intake port 3 is made of an aluminum alloy (specifically, duralumin having a higher strength than a general aluminum alloy for cylinder head casting) or an SUS, which partitions an upstream gathering portion into a pair of upper and lower divided intake ports 3a and 3b. A partition plate 6 is provided over substantially the entire length of the collecting portion.

Although not shown, a tumble control valve for opening and closing the lower divided intake port 3b is provided in the lower divided intake port 3b, and the tumble control valve is closed so that the intake air flows into the cylinder 2 only through the upper divided intake port 3a. By introducing it into the intake port, it is possible to enhance the tumble flow of the intake air and improve the fuel efficiency.
The partition plate 6 is cast into the cylinder head 1 when casting the cylinder head 1.

Specifically, as shown in FIG. 4, the partition plate 6 is set on a core 10 for forming an intake port at the time of cylinder head casting, and the side edge 6 a of the partition plate 6 is set on the side of the core 10. And is cast into the inner wall of the intake port of the cylinder head 1 at the side edge 6a.
By adopting a structure in which the partition plate 6 is fixed to the cylinder head 1 by casting in this way, the partition plate 6 can be made sufficiently thin (for example, 1 to 2 mm), and the ventilation resistance can be suppressed. The partition plate 6 can be formed of a suitable material such as duralumin or SUS different from the cylinder head 1. Further, since there is no need to separately attach the partition plate 6 to the cylinder head 1, manufacturing is easy.

  In the present invention, as shown in FIG. 2, a portion 21 of the end portion of the partition plate 6 on the intake port opening surface (hereinafter, referred to as a head end surface) 5 side of the cylinder head 1 is located in the intake port passage cross section. The portion 22 located inside the head end surface 5 in the drawing S1 and outside the cross section of the intake port passage and cast into the intake port inner wall portion of the cylinder head 1 is projected from the head end surface 5 to the outside S2 in the drawing and is post-processed. The head is formed flush with the end face 5. Hereinafter, the portion 21 is referred to as a concave portion, and the portion 22 is referred to as a convex portion. The corners of the projections 22 of the partition plate 6 are previously rounded or chamfered.

The reason and effect of the above configuration will be described in detail below.
When the partition plate 6 is set on the core 10 and cast, the difference in thermal expansion between the partition plate (aluminum alloy) 6 and the core (casting sand) 10 (the thermal expansion of the partition plate 6 is larger) is shown in FIG. As shown in FIG. 5 (a), a crack (break) W occurs in the core 10 and hot water (aluminum) enters the cracked portion, and after casting, burrs (cast burrs) remain at the tip of the partition plate 6. Would. The crack W is generated at one of the two end portions of the partition plate 6, but the core side has a smaller core cross section, and the head end face side has a baseboard for supporting the core 10 integrally. Because of the presence of casting sand 12, it generally occurs on the cylinder side.

  However, such burrs remaining in the product shape (on the cylinder side) have a great effect on the intake performance and the deburring operation is not easy, so that as shown in FIG. By reducing the cross-sectional area of the core on the side of the baseboard 12 by forming a cut portion 12a in a part of the baseboard, cracks W are likely to be generated on the side of the baseboard 12 and burrs occur on the head end face side. It is desirable to make

In view of such a point, the present inventors first examined a plan A and a plan B shown as reference examples in FIG.
In the plan A, the partition plate is protruded from the end face of the head (extended to the outside of the product shape), a part is provided outside the end face of the head using a baseboard, and a crack is generated at this part.
In this case, since the burrs can be out of the product shape, the burrs can be dropped together by processing (cutting) the projection of the partition plate at the same time as finishing the head end face.

  However, since the protruding portion extends over the entire radial direction of the port, a force is applied to the protruding portion during processing, and the partition plate is deformed. In particular, in the case of the siyamies type, the width of the partition plate becomes long, and there is a limit in support at both ends (the center of the partition plate becomes unconstrained), so that the partition plate is significantly deformed. Such deformation of the partition plate adversely affects the intake performance. Further, since the entire long protruding portion is processed, the processability is poor, and abnormal noise is generated during the processing.

In the plan B, the partition plate is inserted (recessed) in the end face of the head.
However, in this case, since burrs are formed on the head end surface of the partition plate, a deburring operation is performed separately from the finish processing of the head end surface, and the workability is deteriorated. .
In the case of plan A or plan B, when the end of the partition plate is cast flush with the end surface of the head, there is a case in which burrs are not generated at the end of the partition plate depending on a formed product, Therefore, some products require deburring and others do not, resulting in poor workability.

  Therefore, in the present invention, by forming the end of the partition plate into the shape described in FIG. 2, that is, as shown in FIG. The recess 21 is located inside the head end face, and the portion located outside the intake port passage cross section and cast into the intake port inner wall portion of the cylinder head is a projection 22 projecting outward from the head end face. Cracks occur on the baseboard 12 side due to the convex portions 22, and thus burrs also occur outside the product shape at the tips of the convex portions 22.

Therefore, it is possible to secure a shape that generates burrs outside the product shape, and at the same time as finishing the head end surface with a cutter, by processing (cutting) the convex portion 22 flush with the head end surface, the burr can be dropped together. It becomes possible.
In addition, the protruding portion 22 that needs to be cut does not extend over the entire radial direction of the port, but is only a part of both ends. Not only is the processing amount small, but the cut portion is strongly supported by the cylinder head, and rigidity is low. Since the portion within the low intake port passage cross section does not need to be shaved, an effect of preventing deformation such as bending of the partition plate 6 can also be achieved.

In addition, as in the present embodiment, by performing rounding or chamfering on the corners of the convex portion 22 at the end of the partition plate 6, post-processing (cutting) of the convex portion 22 by the cutter can be performed more smoothly. And the occurrence of processing burrs can be prevented.
Next, another embodiment of the present invention (an embodiment in which an additional configuration is added to the above configuration) will be described.

In the embodiment shown in FIG. 8, the side edge 6 a of the partition plate 6 is bent in a direction (vertical direction) intersecting with the plate surface of the partition plate 6 and cast into the inner wall of the intake port 3 of the cylinder head 1. .
According to this, the resistance force in the case of being pulled in the center direction of the intake port 3 increases, and the partition plate 6 is less likely to be pulled off by the cutter during the post-processing, so that the deformation of the partition plate 6 can be further prevented.

In the embodiment shown in FIG. 9, as shown in FIGS. 9A to 9D, the partition plate 6 is provided with a bend (or bead) so that thermal expansion in the radial direction of the intake port can be absorbed.
Among them, (a) is one which is bent in one direction in advance. (B) is to provide a bead and locally absorb the deformation. (C) has two beads, which absorb a large amount of deformation, and there is no bead at the center of the port, so that the deterioration of the intake performance is reduced. (D) shows a configuration in which the center of the port is formed into a flat plate by bending at two places on both ends.

Next, an embodiment in which a caulking portion is added will be described as still another embodiment of the present invention.
In the present invention, when the partition plate 6 is cast into the cylinder head 1, the partition plate 6 is allowed to extend to the head end face 5 side, so that the difference in the thermal expansion coefficient between the cylinder head 1 and the partition plate 6 causes Alternatively, due to the difference in cooling between the two after casting, the binding force may be weakened due to relative movement or the like, and the partition plate 6 may rattle after the product is completed.

As a countermeasure, an embodiment in which caulking portions k1 and k2 are added as shown in FIGS. 10 and 11 or an embodiment in which caulking portions k3 and k4 are added as shown in FIGS. 12 and 13 is adopted. Is valid.
In the embodiment shown in FIGS. 10 and 11, an end surface (k1) of the partition plate 6 that is exposed to the head end surface 5 after post-processing at a portion cast into the intake port inner wall portion of the cylinder head 1 and / or A punch is driven into the head end surface (k2) near the end surface (k1) by an automatic machine or the like, and the cast portion and the cast portion are caulked by plastic deformation.

That is, the caulked portion k1 causes the cast portion to bulge or the caulked portion k2 causes the cast portion to bulge, thereby generating a binding force and preventing the partition plate 6 from rattling. can do.
In this case, the portions to be swaged, that is, the portions (k1 and k2) into which the punches are to be driven are located at positions (inside the escape holes 102) which do not interfere with the gasket mounted between the head end surface 5 and the flange surface of the intake manifold. I do. This can prevent the gasket from affecting the sealing performance. In FIG. 11, reference numeral 101 denotes a screw hole for mounting the intake manifold on the head end face 5, and reference numeral 102 denotes a relief hole for the intake port 3 and the screw hole 101 of the gasket.

In the embodiment shown in FIGS. 12 and 13, a partition (k3) close to the intake port inner wall surface of the cylinder head 1 on the plate surface of the partition plate 6 and / or a partition wall at the intake port inner wall surface of the cylinder head 1. A punch is manually driven into a portion (k4) close to the plate surface of the plate 6, and the cast portion and the cast portion are caulked by plastic deformation.
That is, the caulked portion k3 causes the cast portion to bulge or the caulked portion k4 causes the cast portion to bulge, thereby generating a binding force and preventing the partition plate 6 from rattling. can do. In this case, caulking may be performed on both sides of the upper and lower surfaces, or may be performed only on one side.

1 is a cross-sectional view of a cylinder head of an internal combustion engine showing an embodiment of the present invention. FIG. 1 is a plan view of an intake port taken along line AA in FIG. 1. FIG. 1 is a view of an intake port opening surface of a cylinder head as viewed from an arrow B in FIG. 1. Perspective view of core for forming intake port Diagram showing core cracking in conventional example Explanatory drawing of reference example (plan A and plan B) Illustration of the present invention The figure which shows the shape of the side edge of a partition plate as another embodiment of this invention. The figure which shows the cross-sectional shape of a partition plate as another embodiment of this invention. Top view of intake port showing caulking portions k1 and k2 Drawing of intake port opening surface showing caulking parts k1 and k2 Sectional view of the cylinder head showing the swaged parts k3 and k4 Drawing of intake port opening surface showing caulking parts k3 and k4

Explanation of reference numerals

1 cylinder head
2 cylinder
3 Intake port (cyamys type)
3a Upper split intake port
3b Lower split intake port
4 Exhaust port
5 Cylinder head intake port opening surface (head end surface)
6 Partition plate
6a Side edge of partition plate
10 Core for forming intake port
12 Baseboard
12a notch
21 recess
22 convex

Claims (16)

In an intake device for an internal combustion engine, a partition plate that partitions an intake port in a cylinder head into a pair of divided intake ports is cast at an inner wall portion of an intake port of the cylinder head at a side edge thereof.
Of the end of the partition plate on the side of the intake port opening surface of the cylinder head, a portion located within the intake port passage section is located inside the intake port opening section of the cylinder head and located outside the intake port passage section. The portion cast into the inner wall portion of the intake port of the cylinder head is formed so as to protrude outward from the intake port opening surface of the cylinder head and to be formed flush with the intake port opening surface by post-processing. Intake device.   2. The intake device for an internal combustion engine according to claim 1, wherein corners of the outwardly protruding portion at an end of the partition plate are rounded or chamfered.   3. The internal combustion engine according to claim 1, wherein a side edge of the partition plate is bent in a direction intersecting a plate surface of the partition plate and cast into an inner wall portion of an intake port of a cylinder head. Air intake device.   At the part of the partition plate, which is cast into the intake port inner wall of the cylinder head, at the end face exposed to the intake port opening face of the cylinder head, or at least one of the intake port opening faces of the cylinder head near the end face. The intake device for an internal combustion engine according to any one of claims 1 to 3, wherein the cast portion and the cast portion are caulked.   The intake device for an internal combustion engine according to claim 4, wherein the caulking connection is performed by driving a punch and performing plastic deformation.   6. The internal combustion engine according to claim 4, wherein the caulking portion is located at a position that does not interfere with a gasket mounted between the intake port opening surface of the cylinder head and the flange surface of the intake manifold. Intake device.   On the plate surface of the partition plate, at least one of a portion adjacent to the intake port inner wall surface of the cylinder head or a portion of the cylinder head intake port inner wall surface adjacent to the plate surface of the partition plate is cast. The intake device for an internal combustion engine according to any one of claims 1 to 3, wherein a portion which is cast and a portion which is cast are connected by caulking.   The intake device for an internal combustion engine according to claim 7, wherein the caulking connection is performed by driving a punch and performing plastic deformation. A partition plate that partitions the intake port in the cylinder head into a pair of split intake ports is set on the core for forming the intake port when casting the cylinder head, and the side edge of the partition plate protrudes from the side of the core. At the side edge, when casting into the intake port inner wall of the cylinder head,
Of the end of the partition plate on the side of the intake port opening surface of the cylinder head, a portion located within the intake port passage section is located inside the intake port opening section of the cylinder head and located outside the intake port passage section. The part cast into the inner wall portion of the intake port of the cylinder head is formed so as to protrude outward from the intake port opening surface of the cylinder head and formed flush with the intake port opening surface by post-processing. Manufacturing method of intake device.   The method of manufacturing an intake device for an internal combustion engine according to claim 9, wherein corners of the outwardly protruding portion at the end of the partition plate are rounded or chamfered.   The internal combustion engine according to claim 9 or 10, wherein the side edge of the partition plate is bent in a direction intersecting with the plate surface of the partition plate and cast into an intake port inner wall portion of a cylinder head. Manufacturing method of intake device.   At the part of the partition plate, which is cast into the intake port inner wall of the cylinder head, at the end face exposed to the intake port opening face of the cylinder head, or at least one of the intake port opening faces of the cylinder head near the end face. The method of manufacturing an intake device for an internal combustion engine according to any one of claims 9 to 11, wherein the cast portion and the cast portion are caulked.   The method for manufacturing an intake device for an internal combustion engine according to claim 12, wherein the caulking connection is performed by driving a punch and performing plastic deformation.   14. The internal combustion engine according to claim 12, wherein the portion to be caulked is at a position that does not interfere with a gasket mounted between the intake port opening surface of the cylinder head and the flange surface of the intake manifold. Manufacturing method of intake device.   On the plate surface of the partition plate, at least one of a portion close to the plate surface of the partition plate, or a portion close to the intake port inner wall surface of the cylinder head, or a portion of the cylinder head suction port inner wall surface, which is close to the plate surface of the partition plate. The method for manufacturing an intake device for an internal combustion engine according to any one of claims 9 to 11, wherein the portion that is cast and the portion that is cast are caulked.   The method for manufacturing an intake device for an internal combustion engine according to claim 15, wherein the caulking connection is performed by driving a punch and performing plastic deformation.

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