WO2020145157A1

WO2020145157A1 - Cylinder head manufacturing method

Info

Publication number: WO2020145157A1
Application number: PCT/JP2019/050944
Authority: WO
Inventors: 小島　光高; 広司石井; 村田　真一
Original assignee: 三菱自動車工業株式会社
Priority date: 2019-01-07
Filing date: 2019-12-25
Publication date: 2020-07-16
Also published as: JP7028344B2; JPWO2020145157A1

Abstract

The present invention is a method for manufacturing a cylinder head having a cylinder head body in which is formed an air intake port that communicates with a combustion chamber, said method comprising: a first step (S10) for inserting a seal member from the combustion chamber side into the air intake port to seal an end part on the combustion chamber side of the air intake port via the seal member; a second step (S20) for inserting a mold into the air intake port from an opening in the air intake port, the opening being formed in a wall section of the cylinder head body; a third step (S30) for tightly adhering the seal member and the mold inside the air intake port; a fourth step (S40) for, after the third step (S30), supplying a molten resin to the inside of the air intake port in which the mold is disposed; and a fifth step (S50) where, after the fourth step (S40), a resin part is formed inside the air intake port by solidifying the molten resin, and the seal member and the mold are subsequently removed from the air intake port.

Description

Cylinder head manufacturing method

The present invention relates to a method for manufacturing a cylinder head having a cylinder head body in which an intake port portion communicating with a combustion chamber is formed.

The cylinder head of a general engine is molded by casting using aluminum or aluminum alloy, for example, and has a relatively high thermal conductivity. Therefore, the intake port connected to the combustion chamber is heated by the heat transmitted from the combustion chamber, and the temperature of the intake air flowing through the intake port rises. When the temperature of intake air rises, the amount of intake air decreases, knocking easily occurs, and engine performance may deteriorate. With respect to such a problem, for example, Patent Document 1 discloses an engine intake passage structure in which a resin heat insulating member is arranged on the inner surface of an intake port to suppress a rise in intake air temperature.

Japanese Patent Laid-Open No. 2018-3601

As a method of disposing a heat insulating member made of resin on the inner surface of the intake port, injection molding can be mentioned as in Patent Document 1 above. That is, this is a method in which the mold is inserted and fixed in the intake port portion of the cylinder head molded by casting, and the space between the inner surface of the intake port portion and the outer surface of the mold is filled with resin. When this method is adopted, it is important to secure a sealing surface so that the resin does not leak to areas other than the above space. However, since the cylinder head itself is a casting, the dimensional accuracy is rough, and it is difficult to secure a sealing surface. On the other hand, it is conceivable to machine the inner surface of the intake port to secure the sealing surface, but inserting a tool into the narrow space on the combustion chamber side for machining requires machining time, machining accuracy, and machining. It is difficult considering the cost.

The method of manufacturing the cylinder head of the present invention has been devised in view of such problems, and it secures the sealing surface on the combustion chamber side and prevents resin leakage even if the cylinder head itself is not subjected to additional processing such as processing. One of the purposes is to do. Note that the present invention is not limited to this purpose, and it is also for the other purpose of the present invention to provide operational effects that are obtained by the respective configurations shown in the modes for carrying out the invention to be described later and that cannot be obtained by the conventional technology. is there.

(1) The method of manufacturing a cylinder head disclosed herein is a method of manufacturing a cylinder head having a cylinder head body in which an intake port portion communicating with a combustion chamber via an intake valve hole is formed. A first step of inserting a seal member from the combustion chamber side with respect to the combustion chamber side, and sealing the end of the intake port portion on the combustion chamber side with the seal member; and a wall portion of the cylinder head body. A second step of inserting a mold into the intake port section from the opening of the intake port section, the seal member inserted in the intake port section in the first step, and the seal member inserted in the intake port section in the second step. A third step of bringing the mold into close contact with the inside of the intake port portion, and a fourth step of supplying molten resin into the intake port portion in which the mold is arranged after the third step, After the fourth step, after the molten resin solidifies to form a resin portion inside the intake port portion, a fifth step of withdrawing the seal member and the mold from the intake port portion is provided. There is.

(2) A first hole portion through which a valve guide is inserted is formed in the cylinder head body so as to communicate with the intake port portion, and the seal member is a seal portion that fits into the intake valve hole. And a guide portion extending from the seal portion and arranged in the first hole portion in a state where the seal portion is fitted in the intake valve hole. In this case, in the first step, the guide portion is inserted from the combustion chamber side before the seal portion, the guide portion is inserted into the first hole portion, and the seal portion is inserted into the intake valve hole. It is preferable to seal the ends by fitting them.

(3) It is preferable that the seal member has a circular O-ring and a holding portion to which the O-ring is attached. In this case, in the first step, the holding portion is inserted into the intake port portion from the combustion chamber side, and the O-ring is brought into close contact with the inner surface of the intake port portion to seal the end portion, In the third step, it is preferable that the holding portion and the mold are brought into close contact with each other.

(4) It is preferable that the cylinder head body is formed with a first hole through which the valve guide is inserted so as to communicate with the intake port. In this case, in the first step, it is preferable that the O-ring is brought into close contact with the inner surface on the upstream side of the opening of the first hole in the intake flow direction.
(5) It is preferable that the mold is a slide mold that is configured by combining a plurality of parts that are divided along a direction in which the intake port portion is inserted and removed.

(6) The cylinder head main body is formed with a second hole portion for attaching a port injection valve so as to communicate with the intake port portion. A stepped portion having a cross-section that changes in size perpendicular to the intake air flow direction is formed, and an expanded portion that expands toward the second hole portion upstream of the stepped portion in the intake air flow direction. And an opening of the second hole portion are formed, and the slide mold includes an upper mold arranged at an upper portion including the expansion portion, a lower mold arranged below the upper mold, and the upper mold. It is preferable to have a central mold arranged between the mold and the lower mold, at least lateral molds arranged on both sides of the central mold, and a valve mold inserted into the second hole. In this case, in the second step, the upper die, the lower die, the central die, and the lateral die are inserted in this order from the opening of the intake port portion, and the valve die is inserted into the second hole portion. Preferably.

(7) In the second step, it is preferable that after the upper mold is inserted from the opening of the intake port portion, the valve mold is inserted into the second hole portion to be integrated with the upper mold.
(8) In the fifth step, the valve mold is extracted from the second hole portion, and the side mold, the center mold, the lower mold, and the upper mold are sequentially extracted from the opening of the intake port portion. Is preferred.

According to the disclosed method of manufacturing a cylinder head, the seal member is inserted into the intake port portion from the combustion chamber side and the end portion of the intake port portion on the combustion chamber side is sealed. The sealing surface on the combustion chamber side can be secured without additional processing. Therefore, the molten resin can be prevented from leaking by pouring the molten resin while the sealing member and the mold are in close contact with each other inside the intake port portion.

FIG. 3 is a schematic front view of the intake side portion of the cylinder head manufactured by the manufacturing method according to the first embodiment as viewed from the front side of the engine. FIG. 2 is a schematic side view of the cylinder head of FIG. 1 viewed from the intake side (a view in the direction of arrow A in FIG. 1 ). FIG. 3 is a cross-sectional view (cross-sectional view taken along the line BB of FIG. 2) showing the configuration around the intake port of the cylinder head of FIG. 1. FIG. 4 is a cross-sectional view showing only a cylinder head main body, excluding a resin portion from the cross-sectional view of FIG. 3. (A) is a flowchart explaining the procedure of the manufacturing method according to the first embodiment, and (b) and (c) are sub-flowcharts of FIG. 5(a). FIG. 4 is a perspective view showing an example of a seal member for molding the intake port shown in FIG. 3, (a) being an integrated state and (b) being a disassembled state. FIG. 4 is a perspective view showing an example of a slide mold for molding the intake port shown in FIG. 3, (a) showing a completely assembled state, and (b) showing a state in which all the molds are disassembled. FIG. 7 is a cross-sectional view (cross-sectional view corresponding to the cross-sectional view taken along the arrow B′-B in FIG. 2) showing a state where the seal member shown in FIG. 6A and the slide die shown in FIG. 7A are inserted. 8A is an enlarged view of a D portion of FIG. 8, and FIG. 8B is an enlarged view of an E portion of FIG. 4A and 4B are perspective views showing another example of a slide mold for molding the intake port shown in FIG. 3, where FIG. 7A is a completely assembled state, and FIG. FIG. 11 is a cross-sectional view showing a state before the side mold of the slide mold shown in FIG. 10B is inserted (a cross-sectional view corresponding to a cross-sectional view taken along the line BB″ of FIG. 2 ). FIG. 11 is a cross-sectional view (cross-sectional view corresponding to the cross-sectional view taken along the line CC in FIG. 1) showing a state in which the seal member shown in FIG. 6A and the slide die shown in FIG. 10A are inserted. It is a perspective view which shows the sealing member and slide mold|die used by the manufacturing method which concerns on 2nd embodiment, (a) is a fully assembled state, (b) is the state which disassembled all components and molds. FIG. 13 is a cross-sectional view (a view corresponding to FIG. 8) showing a state in which the seal member and the slide die shown in FIG. 13A are inserted. It is a flow chart explaining the procedure of the manufacturing method concerning a second embodiment.

A method of manufacturing a cylinder head as an embodiment will be described with reference to the drawings. The embodiments described below are merely examples, and are not intended to exclude various modifications and application of techniques that are not explicitly described in the following embodiments. Each configuration of the present embodiment can be variously modified and implemented without departing from the spirit thereof. In addition, they can be selected or combined as needed.

[1. First embodiment]
[1-1. Cylinder head structure]
FIG. 1 is a schematic front view of an intake side portion of a cylinder head 1 manufactured by the manufacturing method according to the present embodiment as viewed from the front side, and FIG. 2 is a side view of the cylinder head 1 (see FIG. 1). (A direction arrow view). The cylinder head 1 is a component that constitutes, for example, an engine mounted on a vehicle. The manufacturing method of the present embodiment is a method of manufacturing the cylinder head 1 by disposing the resin portion 20 in the intake port portion 11 of the cylinder head body 10 described later.

In the present embodiment, the cylinder head 1 of the engine in which four cylinders are arranged side by side in a row and two intake valves and two exhaust valves are provided in one cylinder is exemplified, but the number of cylinders and the number of valves are Is not limited to this. Further, the engine of the present embodiment includes a cylinder injection valve (not shown) that injects fuel into the combustion chamber 2 (see FIG. 3) and a port injection valve (not shown) that injects fuel into the intake port 3. Equipped. Note that FIG. 3 is a cross-sectional view (a cross-sectional view taken along the line BB of FIG. 2) showing the configuration around the intake port 3.

As shown in FIGS. 2 and 3, the cylinder head 1 manufactured by the manufacturing method of the present embodiment includes a cylinder head body 10 molded by casting using aluminum or an aluminum alloy, and a resin portion 20 (described later). (See FIG. 3). In the cylinder head 1, an intake port 3, a port injection valve mounting hole 5 (second hole portion), and an in-cylinder injection valve mounting hole 6 are formed for each cylinder. The intake port 3 and the mounting

holes

5 and 6 are open to the outside of the cylinder head 1. In addition, a pedestal portion 8 to which a delivery pipe connected to an in-cylinder injection valve is fixed, and an injection port 9 for supplying a molten resin to be a resin portion 20 are provided on the intake side wall portion 1a of the cylinder head 1. Has been formed. Note that, in FIG. 2, the reference numerals of the intake port 3, the mounting

holes

5 and 6, the pedestal portion 8 and the like that are similarly provided in each of the four cylinders are given to only one cylinder.

The cylinder head main body 10 constitutes the main body of the cylinder head 1, and as shown in FIGS. 3 and 4, has a combustion chamber 2, mounting

holes

5, 6 and the like, and constitutes the intake port 3. It has an intake port section 11 as a section. 4 is a cross-sectional view showing only the cylinder head body 10 without the resin portion 20 from the cross-sectional view of FIG. The intake port portion 11 of the present embodiment is formed in a bifurcated shape that communicates with the combustion chamber 2 via the two intake valve holes 4. In FIGS. 3 and 4, the wall portion that divides the intake port portion 11 into two forks is not shown.

In the cylinder head body 10 of the present embodiment, an insertion hole 7 (first hole portion) through which a valve guide (not shown) is inserted and a port injection valve mounting hole 5 are both formed so as to communicate with the intake port portion 11. ing. Further, the intake port portion 11 is provided with an expanded portion 16 which is formed so as to spread to the side where the port injection valve is attached (upper side in FIG. 4), an opening 5a of the attachment hole 5 and an opening 7a of the insertion hole 7. ing.

As shown in FIG. 3, the resin portion 20 is a heat insulating member (resin member) that is arranged along the inner surface of the intake port portion 11 and that suppresses the heat of the cylinder head body 10 from being transferred to the intake air. The resin portion 20 is formed of a resin having a lower thermal conductivity than the material of the cylinder head body 10, and more preferably a resin having a high heat resistance. The resin portion 20 is formed by solidifying the molten resin that is poured into the intake port portion 11 by injection molding. In FIG. 3, the resin portion 20 is shown with dots for easy understanding.

The resin portion 20 of the present embodiment is arranged in the entire length of the intake port portion 11 except for the portion on the combustion chamber 2 side (downstream portion). In other words, the intake port portion 11 has a portion where the resin portion 20 is not arranged and a portion where the resin portion 20 is arranged. Hereinafter, the former portion will be referred to as the exposed portion 12, and the latter portion will be referred to as the covering portion 13. That is, the exposed portion 12 is a portion where the material surface of the cylinder head body 10 directly contacts (exposes) the intake air, and the covering portion 13 is covered with the resin portion 20 and the material surface of the cylinder head body 10 is covered. Is the part that does not directly contact the intake air. The resin portion 20 of the present embodiment constitutes the inner surface of the intake port 3 together with the exposed portion 12.

As shown in FIGS. 3 and 4, the exposed portion 12 is located on the combustion side 2 side of the intake port portion 11, and the covering portion 13 is upstream of the exposed portion 12 in the intake flow direction (hereinafter, simply “upstream side”). Is called). The covering portion 13 has a cross-sectional shape (hereinafter, simply referred to as “cross-sectional shape”) orthogonal to the intake air flow direction, which is slightly larger than the exposed portion 12. Therefore, at the boundary between the exposed portion 12 and the covering portion 13 (in the middle of the intake port flow direction in the intake port portion 11), the step portion 14 whose cross-sectional size changes is provided. In the present embodiment, the expansion portion 16 and the opening 5a of the mounting hole 5 are located upstream of the step portion 14, and the opening 7a of the insertion hole 7 is downstream of the step portion 14 in the intake flow direction ( Hereinafter, it is simply referred to as "downstream side". Further, in the intake port portion 11 of the present embodiment, the portion from the opening 11a formed in the wall portion 1a of the cylinder head body 10 to the step portion 14 is linearly formed. An intake manifold (not shown) is connected to the opening 11a of the intake port portion 11.

The step portion 14 of the present embodiment is located at the bifurcation point 15 (see FIG. 4) of the intake port portion 11 or on the downstream side of the bifurcation point 15. The step portion 14 is located upstream of the opening 7a of the insertion hole 7 of the valve guide. That is, two step portions 14 are provided in one intake port portion 11, and each step portion 14 is provided separately from the combustion chamber 2. In the cylinder head body 10 of the present embodiment, the end of the intake port portion 11 on the side of the opening 11a (upstream end in the intake air flow direction) is narrowed, and the resin portion 20 is not arranged in this portion. An exposed portion 12' is provided.

[1-2. Cylinder head manufacturing method]
Next, regarding the method of manufacturing the cylinder head 1 by disposing the resin portion 20 in the intake port portion 11 of the cylinder head body 10 described above, the flowcharts shown in FIGS. 5A to 5C and FIGS. Will be described with reference to. In the present embodiment, a case will be described in which the resin member 20 is formed using the seal member 40 shown in FIGS. 6A and 6B and the mold 30 shown in FIGS. 7A and 7B.

First, as shown in FIG. 5A, the seal member 40 is inserted into the intake port portion 11 from the combustion chamber 2 side, and the end portion of the intake port portion 11 on the combustion chamber 2 side (downstream end portion). Is sealed (first step S10). In this embodiment, since the intake port portion 11 has a bifurcated shape, the two seal members 40 are inserted into one intake port portion 11 to seal the end portion of the intake port portion 11 on the combustion chamber 2 side.

As shown in FIGS. 6A and 6B, the seal member 40 of this embodiment is configured by combining two members, a first member 41 and a second member 42. The first member 41 has a seal portion 41a shaped to fit into the intake valve hole 4, and a rod-shaped guide portion 41b extending from the seal portion 41a. The seal portion 41a is a portion fitted into the intake valve hole 4 from the combustion chamber 2 side, and the guide portion 41b is a portion arranged in the insertion hole 7 in a state where the seal portion 41a is fitted in the intake valve hole 4. Is. The shape of the guide portion 41b is not particularly limited as long as it can be inserted into the insertion hole 7, but if the shape of the guide portion 41b is such that the guide portion 41b is fitted in the insertion hole 7 without a gap, the guide portion 41b allows the insertion hole 7 to be inserted. Can be sealed.

The second member 42 has a circular O-ring 43 and a holding portion 42a to which the O-ring 43 is attached. The holding portion 42a is a portion that holds the O-ring 43 and is arranged on the exposed portion 12 of the intake port portion 11, and the end surface of the intake port portion 11 arranged on the covering portion 13 side (upstream side) is flat. Has been formed. The holding portion 42a is provided with a hole 42b through which the guide portion 41b is inserted. The hole portion 42b is a portion that is arranged coaxially with the insertion hole 7 in a state where the holding portion 42a is arranged in the exposed portion 12 of the intake port portion 11. The first member 41 and the second member 42 are integrated by inserting the guide portion 41b of the first member 41 into the hole portion 42b of the second member 42.

As shown in FIG. 8, in the first step S10 of the present embodiment, first, the second member 42 is inserted into the intake port portion 11 from the combustion chamber 2 side, and the stepped portion of the inner surface of the intake port portion 11 is inserted. The O-ring 43 is brought into close contact with the portion immediately downstream of 14 (that is, upstream of the opening 7a of the insertion hole 7). Next, the first member 41 is inserted into the intake port portion 11 from the combustion chamber 2 side. Specifically, the guide portion 41b of the first member 41 is inserted from the combustion chamber 2 side before the seal portion 41a, and the guide portion 41b is inserted into the insertion hole 7 through the hole portion 42b of the second member 42. At the same time, the seal portion 41 a of the first member 41 is fitted into the intake valve hole 4. Thus, in the present embodiment, the second member 42 is prevented from coming off by pressing the second member 42 from the combustion chamber 2 side with the first member 41.

Next, the mold 30 is inserted into the intake port portion 11 through the opening 11a of the intake port portion 11 [second step S20 in FIG. 5(a)]. Here, an example of the mold 30 is shown in FIGS. The mold 30 of the present embodiment has an outer shape smaller than the inner shape of the intake port portion 11 and is divided into a plurality of parts that are divided along the direction in which the intake port portion 11 is inserted and removed (the intake air circulation direction). It is a slide type that is configured by combining. The slide mold 30 of the present embodiment includes an upper mold 31 arranged at an upper part including the expansion portion 16 of the intake port portion 11, a lower mold 32 arranged below the upper mold 31, an upper mold 31 and a lower mold. It has a central mold 33 arranged between 32, side molds 34 arranged at least on both sides of the central mold 33, and a valve mold 35 inserted into the mounting hole 5.

The upper mold 31 has an upper surface conforming to the shape of the expansion portion 16 and a flat lower surface. The end of the upper mold 31 on the combustion chamber 2 side is bifurcated, and a hole into which the valve mold 35 is fitted is formed on the upper surface of the upper mold 31. The lower mold 32 has a lower surface conforming to the shape of the lower surface side of the intake port portion 11 and a flat upper surface, and the end portion on the combustion chamber 2 side is formed in a bifurcated shape. The central mold 33 has a flat upper surface, a lower surface, and both side surfaces, expands from the end portion on the opening 11a side toward the end portion on the combustion chamber 2 side, and the end portion on the combustion chamber 2 side is bifurcated. Is formed in. The central mold 33 is formed so as to be slidable with respect to both the upper mold 31 and the lower mold 32 arranged in the space inside the intake port portion 11.

The side molds 34 are formed on both sides of the central mold 33 and between the upper mold 31 and the lower mold 32. Specifically, each of the two lateral dies 34 has a flat surface on each upper surface, each lower surface, and each side surface on the side of the central mold 33, and faces from the end portion on the opening 11a side toward the end portion on the combustion chamber 2 side. It has a tapered shape. Further, each of the side molds 34 is formed slidably with respect to each of the molds 31 to 33 arranged in the space inside the intake port portion 11. The valve die 35 has an outer shape that is substantially the same as the shape of the mounting hole 5, and the tip portion of the valve die 35 enters the expansion portion 16 through the mounting hole 5 and fits into the hole formed on the upper surface of the upper die 31. Is formed. The valve die 35 has a function of holding the upper die 31 by fitting into the hole of the upper die 31. In the state where the five types of molds 31 to 35 are combined, the slide mold 30 has a flat tip portion (the end surface arranged on the combustion chamber 2 side).

The procedure of the second step S20 of inserting the slide mold 30 will be described. In the second step S20, the upper die 31, the lower die 32, the central die 33, and the lateral die 34 are inserted in this order from the opening 11a of the intake port portion 11, and the valve die is attached to the attachment hole 5 for attaching the port injection valve. Insert 35. Unlike the other molds 31 to 34, the valve mold 35 is inserted into the mounting hole 5 and combined with the upper mold 31 in the intake port portion 11 to hold the upper mold 31. Is preferably after the upper mold 31 is inserted, and more preferably (immediately after) the upper mold 31 is inserted.

In the present embodiment, as shown in FIG. 5B, first, the upper die 31 is inserted from the opening 11a and accommodated in the upper portion including the expansion portion 16 (step S21), and in this state, the valve die 35 is attached to the mounting hole. 5, and the tip of the valve die 35 is fitted into the hole in the upper surface of the upper die 31 to integrate the valve die 35 and the upper die 31 (step S23). Then, the lower mold 32 is inserted from the opening 11a and arranged in the lower part (step S25), and further, the central mold 33 is inserted while being slid with respect to both the upper mold 31 and the lower mold 32 (step S27). Inside the intake port section 11, the three molds 31 to 33 are assembled. Finally, the two side molds 34 are inserted into the three molds 31 to 33 while sliding them (step S29) to bring the slide mold 30 into the state shown in FIG.

Then, the seal member 40 inserted into the intake port portion 11 in the first step S10 and the slide die 30 inserted into the intake port portion 11 in the second step S20 are brought into close contact with each other inside the intake port portion 11 [FIG. Third step S30 of a)]. More specifically, as shown in FIG. 9A, the holding portion 42a of the second member 42 and the tip portion of the slide die 30 are brought into close contact with each other at the step portion 14 of the intake port portion 11.

After the third step S30, the molten resin is supplied into the intake port portion 11 in which the seal member 40 and the slide die 30 are arranged [fourth step S40 in FIG. 5(a)]. In the cylinder head body 10 of the present embodiment, since the injection port 9 (see FIG. 2) for supplying the molten resin is formed for each cylinder, the injection port (not shown) is connected to each injection port 9 to melt the molten resin. Pour. The molten resin spreads into the space formed between the inner surface of the intake port portion 11 and the outer surface of the slide die 30.

Here, the edge portion on the combustion chamber 2 side in the space where the molten resin spreads is sealed by an O-ring 43 attached to the holding portion 42a of the second member 42, as shown in FIG. 9A. Therefore, resin leakage to the combustion chamber 2 side is avoided. Further, in the present embodiment, the intake valve hole 4 located closer to the combustion chamber 2 than the O-ring 43 is sealed by the seal portion 41a of the first member 41. With such a double seal structure of the O-ring 43 and the seal portion 41a, resin leakage to the combustion chamber 2 side can be more reliably avoided.

On the other hand, when the slide die 30 is inserted into the intake port portion 11, as shown in FIG. 9B, the throttle portion (second exposed portion 12 ′) on the upstream side of the intake port portion 11 and the slide die 30 are connected to each other. A slight gap is formed between the two. While this gap has a function of absorbing the displacement of the slide die 30, the molten resin may leak. Therefore, the slide die 30 of the present embodiment is equipped with the burr-cutting component 36 that comes into close contact with the flange surface 11b of the opening 11a of the intake port portion 11. As a result, the edge portion on the side of the opening 11a in the space where the molten resin spreads is also sealed, and resin leakage is avoided.

After the fourth step S40, after the resin portion 20 is formed inside the intake port portion 11 by solidifying the molten resin [YES route of step S45 in FIG. 5A], the sealing member 40 and the slide die 30 And are extracted from the intake port portion 11 [fifth step S50 in FIG. 5(a)]. In the fifth step S50 of the present embodiment, the seal member 40 is pulled out from the intake port portion 11 to the combustion chamber 2 side in the order of the first member 41 and the second member 42. Further, the valve die 35 is pulled out from the mounting hole 5 for mounting the port injection valve, and the side die 34, the central die 33, the lower die 32, and the upper die 31 are pulled out in this order from the opening 11a of the intake port portion 11. The valve mold 35 may be removed at any timing before the upper mold 31 is removed, and more preferably immediately before the upper mold 31 is removed.

In the present embodiment, as shown in FIG. 5(c), the two side molds 34 are slid and extracted (step S51), and then the central mold 33 is extracted (step S53). Next, the lower mold 32 is lifted to the space created by removing the central mold 33, and then removed (step S55). Further, the valve mold 35 is removed (step S57), and the upper mold 31 is lowered into the space created by removing the central mold 33 and the lower mold 32 and then removed (step S59). Thus, by removing the side mold 34 and the center mold 33 first, it is possible to remove the lower mold 32 and the upper mold 31 while avoiding contact with the inner surface of the resin portion 20 as much as possible.

The mold 30 is not limited to the slide mold shown in FIGS. 7A and 7B, and a mold 30′ shown in FIGS. 10A and 10B may be used, for example. Like the slide die 30, the die 30' also has an outer shape smaller than the inner shape of the intake port portion 11, and is arranged along the direction of inserting/removing with respect to the intake port portion 11 (intake air circulation direction). It is a slide type configured by combining a plurality of divided parts. Specifically, the upper die 31' disposed on the upper portion of the intake port portion 11 including the expansion portion 16, the lower die 32' disposed below the upper die 31', the upper die 31' and the lower die. It has a central mold 33' arranged between 32', a lateral mold 34' arranged at least on both sides of the central mold 33', and a valve mold 35' inserted into the mounting hole 5.

Unlike the side mold 34 described above, the side mold 34' shown in FIGS. 10(a) and 10(b) is formed in a shape that also contacts both sides of the upper mold 31' and the lower mold 32'. That is, each of the lateral dies 34 ′ has the same height dimension as the dimension from the upper surface of the upper die 31 ′ to the lower surface of the lower die 32 ′, and the three die 31 arranged in the space inside the intake port portion 11. It is formed so as to come into surface contact with all of the side surfaces of'-33' and to be slidable with respect to these side surfaces. Similar to the side mold 34, the side mold 34' is formed in a tapered shape from the end on the side of the opening 11a toward the end on the side of the combustion chamber 2. The upper mold 31', the lower mold 32', the central mold 33', and the valve mold 35' are configured in the same manner as the above-mentioned

molds

31, 32, 33, 35.

Even when this slide mold 30' is used, the resin portion 20 can be molded by the above-mentioned procedure [procedures in FIGS. 5(a) to 5(c)]. That is, in the second step S20, the upper die 31' is inserted from the opening 11a and accommodated in the upper portion including the expansion portion 16 (step S21), and in this state, the valve die 35' is inserted into the mounting hole 5 to The valve mold 35' and the upper mold 31' are integrated by fitting the tip of the 35' into the hole on the upper surface of the upper mold 31' (step S23). Then, the lower die 32' is inserted from the opening 11a and placed in the lower portion (step S25), and the central die 33' is slid and inserted into both the upper die 31' and the lower die 32' (step S25). (Step S27), as shown in FIG. 11, the three molds 31′ to 33′ are assembled inside the intake port portion 11. Finally, the two side molds 34' are inserted into the respective three molds 31' to 33' while sliding them (step S29) to bring the slide mold 30' into the state shown in FIG.

Then, as described above, the seal member 40 inserted into the intake port portion 11 in the first step S10 and the slide die 30' inserted into the intake port portion 11 in the second step S20 are installed inside the intake port portion 11. They are brought into close contact [third step S30 in FIG. 5(a)]. After the third step S30, the molten resin is supplied into the intake port portion 11 in which the seal member 40 and the slide die 30' are arranged [fourth step S40 in FIG. 5(a)]. Here, the edge portion on the combustion chamber 2 side in the space in which the molten resin spreads is, as described above, the O-ring 43 attached to the holding portion 42a of the second member 42 and the first member fitted to the intake valve hole 4. Since it is doubly sealed by the seal portion 41a of 41, resin leakage to the combustion chamber 2 side is avoided. On the other hand, the edge portion on the side of the opening 11a in the space where the molten resin spreads is sealed by the burr-cutting component 36' to prevent resin leakage.

After the fourth step S40, after the resin portion 20 is formed inside the intake port portion 11 by solidifying the molten resin [YES route of step S45 in FIG. 5A], the sealing member 40 and the slide die 30 'And are taken out from the intake port portion 11 [fifth step S50 of FIG. 5(a)]. That is, in the fifth step S50, as described above, the seal member 40 is removed from the combustion chamber 2 side in the order of the first member 41 and the second member 42. Further, the two side molds 34' are slid and removed (step S51), and then the central mold 33' is removed (step S53). Next, the lower mold 32' is lifted to the space created by removing the central mold 33', and then removed (step S55). Further, the valve mold 35' is removed (step S57), and the upper mold 31' is lowered into the space created by removing the central mold 33' and the lower mold 32', and then removed (step S59).

Although FIG. 5A illustrates the case where the first step S10 is performed before the second step S20, the first step S10 of the present embodiment may be performed after the second step S20. However, it may be performed simultaneously with the second step S20. In other words, which of the seal member 40 and the

slide molds

30 and 30 ′ of this embodiment may be inserted into the intake port portion 11 first.

[1-3. Action, effect]
(1) In the method for manufacturing the cylinder head 1 described above, the seal member 40 is inserted into the intake port portion 11 from the fuel chamber 2 side to seal the end portion of the intake port portion 11 on the combustion chamber 2 side, and to open the opening. The molds 30 and 30' are inserted from 11a. Then, since the molten resin is poured in the state where the seal member 40 and the molds 30 and 30' are in close contact with each other inside the intake port portion 11, the leakage of the molten resin can be prevented. That is, the sealing surface on the combustion chamber 2 side can be ensured and the resin leakage can be prevented even if the cylinder head body 10 that is a cast product is not subjected to additional processing. Further, by disposing the resin portion 20 in the intake port portion 11, it is possible to suppress the temperature rise of the intake air, so that it is possible to suppress the decrease of the intake air amount and the occurrence of knocking, and it is possible to improve the engine performance.

(2) The first member 41 of the seal member 40 described above is arranged in the insertion hole 7 with the seal portion 41a fitted into the intake valve hole 4 and the seal portion 41a fitted in the intake valve hole 4. A guide portion 41b is provided. Therefore, when the first member 41 is inserted into the intake port portion 11, the seal portion 41a can be guided to the intake valve hole 4 by inserting the guide portion 41b into the insertion hole 7 from the combustion chamber 2 side. .. Therefore, it becomes easy to properly arrange the first member 41 with respect to the intake port portion 11. Further, by disposing the guide portion 41b in the insertion hole 7 and fitting the seal portion 41a in the intake valve hole 4, the intake valve hole 4 is sealed by the seal portion 41a and the molten resin in the insertion hole 7 is sealed. Leakage can be suppressed by the guide portion 41b. If the guide portion 41b has a shape that fits inside the insertion hole 7, the insertion hole 7 can be sealed by the guide portion 41b, so that leakage of the molten resin into the insertion hole 7 can be prevented.

(3) The holding portion 42a of the seal member 40 is inserted into the intake port portion 11, the O-ring 43 attached to the holding portion 42a is brought into close contact with the inner surface of the intake port portion 11, and then the holding portion 42a and the mold 30 are inserted. By closely contacting 30' with the inside of the intake port portion 11, leakage of the molten resin can be prevented more reliably. Further, the O-ring 43 can be easily arranged inside the intake port section 11 by inserting the holding section 42a to which the O-ring 43 is attached from the combustion chamber 2 side into the intake port section 11.

Further, by arranging the O-ring 43 inside the intake port portion 11, a portion of the inside of the intake port portion 11 on the downstream side of the O-ring 43 can be the exposed portion 12. That is, in this case, since the resin portion 20 is not arranged in the portion of the intake port portion 11 on the combustion chamber 2 side, even if a high-temperature gas enters the intake port 3 due to the backflow of exhaust gas, the resin portion 20 is deteriorated. Can be suppressed. Further, as described above, by double sealing the end portion of the intake port portion 11 on the combustion chamber 2 side by both the seal portion 41a and the O-ring 43, it is possible to more reliably prevent leakage of the molten resin.

(4) The leakage of the molten resin into the insertion hole 7 can be prevented by bringing the O-ring 43 into close contact with the inner surface of the intake port portion 11 on the upstream side of the opening 7a of the insertion hole 7. Further, in this case, since the resin portion 20 is not arranged on the downstream side of the opening 7a of the insertion hole 7, it is possible to effectively suppress the deterioration of the resin portion 20 due to the influence of the high temperature gas flowing back from the combustion chamber 2. ..

(5) Since the above-described molds 30 and 30' are slide molds configured by combining a plurality of parts that are divided along the direction in which the intake port portion 11 is inserted and removed, the intake port portion 11 is Even if the shape is an undercut, it can be easily removed and inserted by the slide molds 30 and 30' composed of a plurality of parts.
(6) Further, by inserting the slide molds 30 and 30' into the intake port portion 11 according to the procedure shown in FIG. 5B, the slide molds 30 and 30' can be easily assembled in the intake port portion 11.

(7) Further, after inserting the upper molds 31 and 31' into the intake port portion 11, the

valve molds

35 and 35' are inserted into the mounting holes 5 to be integrated with the

upper molds

31 and 31'. , 35' can hold the upper mold 31, 31'. As a result, the attitude of the slide molds 30 and 30' can be stabilized in the intake port portion 11, and the variation in the thickness of the resin portion 20 can be suppressed.

(8) In the manufacturing method described above, the slide molds 30 and 30' are pulled out from the intake port portion 11 by the procedure shown in FIG. 5C, so that the side molds 34 and 34' and the central molds 33 and 33' are first processed. The lower molds 32, 32' and the upper molds 31, 31' can be moved to the space formed by the removal and then removed. As a result, the lower molds 32, 32' and the upper molds 31, 31' can be removed without contacting the resin part 20.

(9) In the intake port portion 11 described above, the portion from the opening 11a to the step portion 14 (mainly the covering portion 13) is formed in a linear shape, so that the outer shape of the mold 30, 30' can be simplified. .. Therefore, the molds 30 and 30' can be easily inserted into and removed from the intake port portion 11, so that the cylinder head 1 can be easily manufactured.

[2. Second embodiment]
A manufacturing method according to the second embodiment will be described with reference to FIGS. 13 to 15. The manufacturing method of the present embodiment differs from the manufacturing method of the first embodiment described above in the seal member 40' and the mold 130 used in the injection molding of the resin portion 20. Hereinafter, elements that are the same as or correspond to the elements described in the first embodiment will be denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIGS. 13A and 13B, the seal member 40 ′ of this embodiment is formed in the same manner as the first member 41 of the seal member 40 described above. That is, the seal member 40' does not have the second member 42 (the O-ring 43 and the holding portion 42a), and is formed in the same manner as the seal portion 41a and the guide portion 41b described above, respectively. It has a part 40b. On the other hand, the mold 130 corresponds to a shape in which the slide mold 30′ illustrated in FIGS. 7A and 7B and the two second members 42 illustrated in FIGS. 6A and 6B are combined. It is a slide type.

Specifically, the slide mold 130 has an upper mold 131, a lower mold 132, a central mold 133, a side mold 134, and a valve mold 135, like the slide mold 30 described above. These molds 131 to 135 are extended at the end on the combustion chamber 2 side so that each of the molds 31 to 35 of the slide mold 30 described above has a portion corresponding to the holding portion 42a of the second member 42. It has the shape shown. Further, the slide mold 130 has a hole portion 137 corresponding to the hole portion 42b of the second member 42 described above in a state where these molds 131 to 135 are completely assembled. Specifically, the hole portion 137 includes a through hole 131 a formed in the upper die 131, a recess 133 a formed in the upper surface of the central die 133, and a recess 134 a formed in the upper surface of each side die 134. Composed by combining.

Hereinafter, a procedure for arranging the resin portion 20 in the intake port portion 11 using the seal member 40′ and the slide mold 130 of the present embodiment will be described. Note that, as shown in FIG. 14, in the present embodiment, the step portion 14 is omitted from the intake port portion 11, and substantially the entire inner surface of the intake port portion 11 becomes the covering portion 13 (the exposed portion 12 is not provided). A cylinder head body 10' is illustrated.

As shown in FIG. 15, in the present embodiment, first, the slide mold 130 is inserted into the intake port portion 11 from the opening 11a of the intake port portion 11 (second step A20). Next, the seal member 40' is inserted into the intake port portion 11 from the combustion chamber 2 side (first step A10). Specifically, the guide portion 40b of the seal member 40' is inserted from the combustion chamber 2 side before the seal portion 40a, and the guide portion 40b is inserted into the insertion hole 7 through the hole portion 137 of the slide mold 130. The seal portion 40a of the seal member 40' is fitted in the intake valve hole 4 to seal the end portion of the intake port portion 11 on the combustion chamber 2 side. Also in the second step A20 of this embodiment, the molds 131 to 135 of the slide mold 130 are inserted into the intake port portion 11 by the procedure shown in FIG. 5B, as in the above-described first embodiment.

Then, similarly to the above-described first embodiment, the seal member 40' inserted into the intake port portion 11 in the first step A10 and the slide mold 130 inserted into the intake port portion 11 in the second step A20 are provided in the intake port portion. The inside of 11 is closely contacted (3rd step A30 of FIG. 15), and the sealing member 40 and the slide mold 130 are brought into the state shown in FIG. Then, the molten resin is supplied into the intake port portion 11 where the seal member 40' and the slide mold 130 are arranged (fourth step A40 in FIG. 15).

Here, since the edge portion on the combustion chamber 2 side in the space where the molten resin spreads is sealed by the seal portion 40a of the seal member 40', resin leakage to the combustion chamber 2 side is avoided. On the other hand, the edge portion on the side of the opening 11a in the space where the molten resin spreads is sealed by the burr-cutting component 136 as in the above-described first embodiment, so that resin leakage is avoided.

After the resin portion 20 is formed inside the intake port portion 11 by solidifying the molten resin (YES route in step A45 of FIG. 15), the seal member 40' and the slide mold 130 are pulled out from the intake port portion 11. (Fifth step A50 in FIG. 15). In the fifth step A50 of this embodiment, the seal member 40' is first pulled out from the combustion chamber 2 side, and then the slide die 130 is pulled out from the opening 11a of the intake port portion 11. The procedure of removing the molds 131 to 135 of the slide mold 130 in the fifth step A50 can be performed by the procedure shown in FIG. 5C, as in the above-described first embodiment.

According to the manufacturing method of the present embodiment, first, the slide mold 130 is inserted from the opening 11a of the intake port portion 11, and then the seal member 40' is inserted into the intake port portion 11 from the fuel chamber 2 side to intake air. The end of the port portion 11 on the combustion chamber 2 side is sealed. After that, as in the above-described first embodiment, the molten resin is poured in the state where the seal member 40 ′ and the mold 130 are in close contact with each other inside the intake port portion 11, so leakage of the molten resin can be prevented. As a result, the sealing surface on the combustion chamber 2 side can be secured and the resin leakage can be prevented even if the cylinder head body 10' is not additionally processed.

Further, according to the manufacturing method of the present embodiment, the end portion of the intake port portion 11 on the combustion chamber 2 side can be sealed only by fitting the seal portion 40a into the intake valve hole 4. That is, since the holding portion 42a and the O-ring 43 described above are not provided, the resin portion 20 can be arranged over substantially the entire length of the intake port portion 11. As a result, the temperature rise of the intake air can be further suppressed, so that the reduction of the intake air amount and the occurrence of knocking can be further suppressed, and the engine performance can be further improved. According to the manufacturing method of this embodiment, the same effect can be obtained from the same configuration as that of the above-described embodiment.

[3. Modification]
The manufacturing method of the cylinder head 1 described above is an example, and is not limited to the procedure described above. For example, the

valve molds

35, 35', 135 may be inserted after the

lower molds

32, 32', 132 and the

side molds

34, 34', 134 are inserted. Further, in the fifth step A50, S50, the

valve molds

35, 35', 135 may be removed first, or the

side molds

34, 34', 134 may be removed next.

The respective configurations of the

molds

30, 30', and 130 described above are examples, and are not limited to those described above. The above-mentioned

molds

30, 30' and 130 are all slide molds composed of five kinds of molds 31 to 35, 31' to 35' and 131 to 135, but the kind and the number of molds are not particularly limited. Further, the mold may be any structure as long as it can be arranged inside the intake port portion 11, and is not a slide mold composed of a plurality of parts (molds) divided along the direction of inserting and removing from the intake port portion 11. Good. For example, when the shape of the intake port portion is not undercut, it may be configured with a single mold.

The configuration of the cylinder head 1 described above is an example, and is not limited to the above. For example, it may not be the cylinder head of an in-line four-cylinder engine, or the cylinder head of an engine equipped with both an in-cylinder injection valve and a port injection valve. Further, it may be a cylinder head of an engine in which one intake valve is provided in one cylinder. In this case, the shape of the intake port portion does not have a bifurcated shape, and the number of seal members 40 and 40' that are inserted into one intake port portion when manufacturing the cylinder head is one.

The configuration of the intake port portion 11 described above is an example, and the position of the stepped portion 14 may be other than the position described above. For example, when the intake port portion 11 has the branch point 15, the stepped portion may be provided on the upstream side of the branch point 15. Further, if the engine is not provided with the port injection valve, the expansion part 16 is also unnecessary. The step portion 14 may be omitted.

The configuration of the seal members 40 and 40' described above is an example, and is not limited to the above. The sealing members 40, 40' may be configured to seal the end portion of the intake port portion 11 on the combustion chamber 2 side, and for example, the

guide portions

41b, 40b may be omitted. Further, when the holding portion 42a to which the O-ring 43 is attached is provided as in the first embodiment described above, the seal portion 41a may be omitted.

1 Cylinder Head 1a Wall 2 Combustion Chamber 3 Intake Port 4 Intake Valve Hole 5 Port Injection Valve Mounting Hole (Second Hole)
5a opening 7 insertion hole (first hole portion)
7a Opening 10 Cylinder Head Main Body 11 Intake Port Part 11a Opening 14 Stepped Part 16 Expanded Part 20

Resin Part

30, 30', 130 Slide Type
31, 31', 131

Upper mold

32, 32', 132

Lower mold

33, 33', 133

Central mold

34, 34', 134

Lateral mold

35, 35', 135 Valve mold 40, 40' Seal member

41a Seal part

41b Guide part 42a Holding part A10,S10 First step A20,S20 Second step A30,S30 Third step A40,S40 Fourth step A50,S50 Fifth step

Claims

A method of manufacturing a cylinder head, comprising a cylinder head body having an intake port portion communicating with a combustion chamber via an intake valve hole,
A first step of inserting a seal member into the intake port portion from the combustion chamber side, and sealing the end portion of the intake port portion on the combustion chamber side with the seal member,
A second step of inserting a mold into the intake port portion from an opening of the intake port portion formed in the wall portion of the cylinder head body;
A third step of bringing the seal member inserted into the intake port section in the first step and the mold inserted into the intake port section in the second step into close contact with each other inside the intake port section;
After the third step, a fourth step of supplying a molten resin inside the intake port portion in which the mold is arranged,
After the fourth step, after the molten resin is solidified to form a resin portion inside the intake port portion, a fifth step of withdrawing the seal member and the mold from the intake port portion, A method of manufacturing a cylinder head, characterized in that
The cylinder head body is formed with a first hole through which a valve guide is inserted so as to communicate with the intake port.
The seal member includes a seal portion that fits into the intake valve hole, and a guide portion that extends from the seal portion and that is disposed in the first hole portion in a state where the seal portion fits into the intake valve hole. And have,
In the first step, the guide portion is inserted from the combustion chamber side before the seal portion, the guide portion is inserted into the first hole portion, and the seal portion is fitted into the intake valve hole. The method of manufacturing a cylinder head according to claim 1, wherein the end portion is sealed by doing so.
The seal member has a circular O-ring and a holding unit to which the O-ring is attached,
In the first step, the holding portion is inserted from the combustion chamber side with respect to the intake port portion, the O-ring is brought into close contact with the inner surface of the intake port portion to seal the end portion,
The method of manufacturing a cylinder head according to claim 1, wherein, in the third step, the holder and the mold are brought into close contact with each other.
The cylinder head body is formed with a first hole through which a valve guide is inserted so as to communicate with the intake port.
4. The method of manufacturing a cylinder head according to claim 3, wherein, in the first step, the O-ring is brought into close contact with the inner surface on an upstream side of an opening of the first hole portion in an intake air flow direction.
5. The mold is a slide mold configured by combining a plurality of parts divided along a direction of inserting and extracting with respect to the intake port portion, wherein the mold is a slide mold. A method of manufacturing a cylinder head according to one item.
In the cylinder head body, a second hole for attaching a port injection valve is formed so as to communicate with the intake port portion,
A step portion of which the size of a cross section orthogonal to the intake flow direction changes is formed midway in the intake flow direction of the intake port portion, and an upstream side of the step portion in the intake flow direction is formed. In the, the expanded portion and the opening of the second hole portion that is widened toward the second hole portion side,
The slide mold includes an upper mold arranged at an upper part including the expansion portion, a lower mold arranged below the upper mold, and a central mold arranged between the upper mold and the lower mold. At least a side mold arranged on both sides of the central mold, and a valve mold inserted into the second hole portion,
In the second step, the upper die, the lower die, the central die, and the lateral die are inserted in this order from the opening of the intake port portion, and the valve die is inserted into the second hole portion. The method for manufacturing a cylinder head according to claim 5, characterized in that
7. In the second step, the upper die is inserted from the opening of the intake port portion, and then the valve die is inserted into the second hole portion to be integrated with the upper die. A method for manufacturing the described cylinder head.
In the fifth step, the valve mold is extracted from the second hole portion, and the side mold, the central mold, the lower mold, and the upper mold are sequentially extracted from the opening of the intake port portion. The method for manufacturing a cylinder head according to claim 6 or 7.