JP2003184640A - Cooling water channel forming method for cylinder head and passage forming core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling water channel forming method for a cylinder head, avoiding an increase in size of a cooling water channel forming core. <P>SOLUTION: A thermostat housing forming core 21 is integrally provided on an upper stage cooling water channel forming core 20 and a bypass channel forming core 11 is integrally provided on a lower stage cooling water channel forming core 10. The two cooling water channel forming cores 10, 20 are superimposed one on the other. An opening portion forming part 23 of the thermostat housing forming core 21 and a connection portion forming part 13 of the bypass channel forming core 11 are arranged on vertical lines with a bottom bypass hole forming part 22 and with a bypass channel lower baseboard 12, respectively. Thus, the increase in size of the cooling water channel forming core is avoided, the cooling water channel forming core is firmly and precisely fixed thereto and a cooling water channel is accurately formed in a product. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a cooling water passage for a cylinder head having a thermostat housing and a core for the passage.

[0002]

2. Description of the Related Art A cooling water passage of a cylinder head is provided with a thermostat and a bypass passage so that cooling water can be circulated without passing through a radiator (for example, Japanese Utility Model Laid-Open No. 7-35741). . In a cylinder head in which cooling water passages are provided in upper and lower two stages, a thermostat housing is provided on one side surface of the cylinder head, and a bypass passage is provided from this one side surface to the other side surface, thereby forming a thermostat housing. A structure in which a bypass passage is in communication is known.

Such a method of forming the cooling water passages in the upper and lower two stages of the cylinder head is conventionally performed by using a core as shown in FIG. In the figure, (a) is a lower cooling water passage forming core 100, and (b) is an upper cooling water passage forming core 200. As is clear from the figure, the cylinder center (c
yl. A core 1 for manufacturing a cylinder head for an in-line 4-cylinder engine, which has four centers).
00 and 200.

Core 20 for forming a thermostat housing
1 is a core 20 for forming the upper cooling water passage as shown in FIG.
It is integrally provided on one side of the end portion of 0 in an overhang state. Further, the bypass passage forming core 101 is provided outside the end portion of the lower cooling water passage forming core 100 and extends over the product (cylinder head) as shown in FIG. , 103 to be integrated with the lower cooling water passage forming core 100.

When a cylinder head is manufactured and upper and lower cooling water passages are formed therein, as shown in FIG. 3, the lower cooling water passage forming core 100 is placed on the lower side, and the upper stage is formed on the lower cooling water passage forming core 100. The cooling water passage forming core 200 is stacked and fixed in the main mold 300. In order to fix the upper and lower cooling water passage forming cores 100, 200 in the main mold 300, a baseboard 302,
More 303 is needed. That is, the thermostat housing forming core 201 to the baseboard 302 are integrally provided so as to correspond to the baseboard 102 in which the bypass passage forming core 101 is integrated, and the upper cooling water is formed to correspond to the baseboard 103. Passage forming core 200 to baseboard 30
3 are integrally provided, and these skirting boards 102, 103, 30
2, 303 is fixed outside the product.

[0006]

By the way, when manufacturing a cylinder head, it is important to firmly fix the cooling water passage forming core and to fix it accurately. In this respect, the method of fixing the cooling water passage forming cores 100 and 200 shown in FIGS.
03, 302, 303 was effective for fixing with precision and firmly, but these baseboards 102, 103, 30
Since 2,303 are provided on the outside of the product (cylinder head), not only the core becomes large, but also the shape is restricted due to the strength of the core and molding reasons. In addition, as shown in FIG. 4, the baseboard (102,
There was also a problem that the meat 401 was attached to the inside of (302).

The present invention has been made in view of the above circumstances, and a method for forming a cooling water passage for a cylinder head and a passage core for avoiding an increase in size of the cooling water passage forming core. It is intended to be provided.

[0008]

In the method for forming a cooling water passage for a cylinder head according to the present invention, which achieves the above object, the invention according to claim 1 is characterized in that the cooling water passage is formed in a plurality of pieces. In a method of forming a cooling water passage for a cylinder head, at least one cooling water passage forming core is integrally provided with a thermostat housing forming core having an opening forming portion and a bottom bypass hole forming portion, and at least another one. A bypass passage forming core having a connecting portion forming portion is integrally provided in the cooling water passage forming core, and these two cooling water passage forming cores are assembled to form an opening portion of the thermostat housing forming core. Part and bottom By arranging the bypass hole forming part, the connecting part forming part of the bypass passage forming core and the bypass passage lower skirting along the longitudinal direction, the bottom A part where the bypass hole forming portion and the connecting portion forming portion are overlapped with each other, and a load applied to the thermostat housing forming core and the bypass passage forming core is overlapped with the bottom bypass hole forming portion and the connecting portion forming portion. It is characterized in that it is supported by the bottom skirting of the bypass passage via the.

According to the first aspect of the present invention, the opening forming portion and the bottom bypass hole forming portion of the thermostat housing forming core, and the connecting portion forming portion of the bypass passage forming core and the bypass passage lower skirting board. Can be stacked in the product along the longitudinal direction, and the cooling water passage can be formed without providing a skirting board outside the product. Therefore, it is possible to prevent the core for forming the cooling water passage from increasing in size and prevent the product from being spoiled.

According to a second aspect of the present invention, in the first aspect of the invention, the opening forming portion and the bottom bypass hole forming portion of the thermostat housing forming core, and the connecting portion forming portion of the bypass passage forming core. And the bottom skirting of the bypass passage are located along the vertical direction.

According to the second aspect of the present invention, the opening forming portion, the bottom bypass hole forming portion, the connecting portion forming portion of the bypass passage forming core, and the bypass passage lower skirting board extend along the vertical direction. Therefore, the load applied to the thermostat housing forming core and the bypass passage core can be reliably supported by the bypass passage lower skirting.

According to a third aspect of the present invention, in the above-mentioned first or second aspect of the invention, the core for forming the cooling water passage, which is integrally provided with the core for forming the thermostat housing, is placed on the upper side, and the core for forming the bypass passage is provided. With the cooling water passage forming core provided integrally, the bottom bypass hole forming portion of the thermostat housing forming core and the connecting portion forming portion of the bypass passage forming core are superposed so as to be in contact with each other. To do.

The present invention is generally applied to the formation of a cooling water passage having an upper cooling water passage and a lower cooling water passage. In the formation of the cooling passage, a core for forming a thermostat housing is integrally provided. With the water passage forming core up,
The cooling water passage forming core, which is integrally provided with the bypass passage forming core, is provided for casting. However, the present invention is not limited to this, and may have other cooling water passages such as side passages.

The invention according to claim 4 is the above-mentioned claims 1 to 3.
In any one of the inventions, a pressing surface formed in the opening forming portion of the thermostat housing forming core,
The overlapping surface of the bottom bypass hole forming portion and the connecting portion forming portion of the bypass passage forming core and the support lower surface of the bypass passage lower skirting board are substantially parallel to each other.

According to the invention of claim 4, the lower surface of the bypass passage lower skirting board is used as a supporting surface for supporting the main mold, and the upper surface of the core for forming the thermostat housing is used as a pressing surface to apply a load applied between them. It can be reliably supported through the surface of the above and the above-mentioned overlapping surface. As a result, it is possible to firmly fix the cooling water passage forming core and improve the fixing accuracy.

According to a fifth aspect of the present invention, there is provided a cooling water passage core for a cylinder head, wherein the thermostat housing forming core having an opening forming portion and a bottom bypass hole forming portion is integrally provided. A molding core,
Cooling of a cylinder head formed by separating a plurality of cooling water passages into which a bypass passage forming core having a connecting portion forming portion and another cooling water passage forming core are stacked. In the water passage forming core, a thermostat housing forming core is provided at one end of the one cooling water passage forming core so that the bypass hole forming portion faces inward and the opening forming portion faces outward. A core for bypass passage is provided at one end of the other core for forming a cooling water passage, and a core portion for bypass passage is provided so that a connecting portion forming portion is located on the tip side of the bend portion. A skirting board support portion is provided on an outer portion of the portion, the bottom bypass hole forming portion and the connecting portion forming portion overlap each other, and the skirting board continuous to the opening portion forming portion outer surface and the skirting board support portion. Outer branch of And it is located and the said opening substantially along the bypass hole forming portion and the connecting portion forming portions and the core print support and baseboards outer support surface loading direction applied between the surfaces.

The skirting board provided on the outer side of the bent portion may be integral with or separate from the bent portion. In the case of one body, the baseboard support portion serves as a connecting portion between the bent portion and the baseboard. Further, the core may include, in addition to one core and another core, another core. According to the configuration of claim 5, the load applied between the outside surface of the opening forming portion and the outside support surface of the skirting board can be supported only by the skirting board and the opening.
No need for extra skirting boards.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A method for forming a cooling water passage for a cylinder head according to the present invention will be described below with reference to FIG. In this embodiment as well, the lower cooling water passage forming core 10 is integrally provided with the bypass passage forming core 11, and the upper cooling water passage forming core 20 is provided with the thermostat housing forming core 21 in an overhung state. The point is that the core 10 for forming the lower cooling water passage is placed in the main mold 30 in the main mold 30 and the core 20 for forming the upper cooling water passage is superposed on the lower core 10 in the main mold 30. The method is similar.

In the present invention, the end of the bypass passage forming core 11 is a curved portion 11a which curves upward, and the bypass passage lower skirting board 12 is integrally provided on the lower side thereof. The connecting portion between the bent portion 11a and the bypass path lower skirting board 12 serves as the skirting board support portion of the present invention. Bypass passage lower baseboard 1
The lower surface 12a of No. 2 is formed horizontally, and a connection portion forming portion 13 which is an end portion of the bypass passage is arranged vertically above the bypass passage lower skirting board 12 and the upper surface 13a thereof is formed horizontally. As a result, the lower surface 12a of the lower skirting board 12 and the upper surface 13a of the connecting portion forming portion 13 are parallel to each other. On the other hand, a thermostat housing forming core 21 is integrally provided at an end of the upper cooling water passage forming core 20.
The core 21 for forming the thermostat housing is formed such that the bottom bypass hole forming portion 22 is formed below and the opening forming portion 23 is located above. The lower surface 22a of the bottom bypass hole forming portion 22 is formed horizontally, and the opening forming portion 23 is located above the lower surface 22a. The lower surface 22 of the bottom bypass hole forming portion 22 is provided on one side of the opening forming portion 23.
The horizontal pressing surface 23a is formed so as to correspond to the vertically upper side of a. Bottom surface 22a of bottom bypass hole forming portion 22
And the horizontal pressing surface 23a of the opening forming portion 23 are parallel to each other.

When the lower cooling water passage forming core 10 is placed inside the main mold 30 and the upper cooling water passage forming core 20 is placed thereon, the bypass passage forming core is arranged. Lower surface 1 of the lower skirting 12 of the bypass passage provided in 11
2a is seated on and supported by the main mold 30, and the bottom bypass hole forming portion 22 of the thermostat housing forming core 21 is provided on the upper surface 13a of the connecting portion forming portion 13.
The lower surface 22a of is overlapped.

By stacking in this way, the bypass passage lower skirting 12, the connecting portion forming portion 13, and the bottom bypass hole forming side of the upper cooling water passage forming core 20 on the lower cooling water passage forming core 10 side are formed. Portion 22 and opening forming portion 23
Are located along the vertical line. In addition, the surface of each part, that is, the lower surface 12a of the bypass passage lower skirting board 12,
Bypass passage lower baseboard 12 support portion, connection portion forming portion 13
The upper surface 13a, the lower surface 22a of the bottom bypass hole forming portion 22 on the upper cooling water passage forming core 20 side, and the horizontal pressing surface 23a of the opening forming portion 23 are also positioned along the vertical line. Therefore, the thermostat housing forming core 21 and the bypass passage forming core 11 are pressed by the upper die 31 via the horizontal pressing surface 23a formed in the opening forming portion 23 of the thermostat housing forming core 21. The cores 10 and 20 for forming the upper and lower cooling water passages are fixed by being supported by the lower baseboard 12 of the bypass passage. As described above, the lower surface 12a, the support portion of the bypass passage lower skirting board 12, the upper surface 13a, the lower surface 22a along the load direction applied to the horizontal pressing surface 23a and the lower surface 12a of the bypass passage lower skirting board 12.
And the horizontal pressing surface 23a is located.

By forming the cooling water passages in the cylinder head in this way, it is possible to form the thermostat housing without providing the skirting board for fixing the upper and lower cooling water passage forming cores 10 and 20 on the outside of the product. The core and the core for forming the bypass passage can be supported. As a result, the core can be prevented from becoming large, the cost for the core can be reduced, and the design of the outer shape of the product can be done without considering the existence of the skirting board. It can also be improved. It is also possible to eliminate the cause of sticky meat because the skirting board is not provided outside the product.

By supporting the bypass passage lower skirting 12 provided on the bypass passage forming core 11 by the main mold 30, and pressing the thermostat housing forming core 21 by the upper mold 31, upper and lower cooling water passages are formed. Since the forming cores 10 and 20 can be firmly fixed and the fixing accuracy can be improved, the upper and lower cooling water passages can be accurately formed inside the product, and the quality can be improved. it can.

As described above, the lower surface 22a of the bottom bypass hole forming portion 22 of the thermostat housing forming core 21 is brought into contact with the upper surface 13a of the connecting portion forming portion 13 of the bypass passage forming core 11. The product can be manufactured with the thermostat housing and the bypass passage communicating with each other.

[0025]

As described above, according to the cooling water passage forming method of the cylinder head of the present invention, the opening forming portion and the bottom of the thermostat housing forming core provided in the cooling water passage forming core. Since the bypass hole forming portion, and the connecting portion forming portion of the bypass passage forming core and the bypass passage lower skirting board are arranged in the vertical direction, preferably on the vertical line, it is possible to support only the bypass passage lower skirting board. Since it is not necessary to provide a skirting board outside the product, it is possible to avoid the generation of spoiled meat and prevent the core for forming the cooling water passage from increasing in size. Further, the core for forming the cooling water passage can be firmly and accurately fixed, and the cooling water passage can be accurately formed in the product.

[Brief description of drawings]

FIG. 1 is a partial front view of a state in which upper and lower cooling water passage forming cores are stacked and fixed in an embodiment of the present invention.

2A and 2B are diagrams illustrating a conventional method, FIG. 2A is a plan view of a lower cooling water passage forming core, and FIG. 2B is a plan view of an upper cooling water passage forming core.

FIG. 3 is a front view of a state in which upper and lower cooling water passage forming cores are similarly stacked and fixed.

FIG. 4 is a partial view for explaining pad meat in a conventional method.

[Explanation of symbols]

10 Core for forming the lower cooling water passage 11 Core for forming bypass passage 11a bent part 12 Bypass passage lower baseboard 12a lower surface 13 Connection part formation part 13a upper surface 20 Core for forming upper cooling water passage 21 Core for forming thermostat housing 22 Bottom bypass hole forming part 22a lower surface 23 Opening part 23a Horizontal holding surface 30 master 31 Upper mold

Claims (5)

[Claims] 1. A method of forming a cooling water passage for a cylinder head, wherein a plurality of cooling water passages are formed separately, wherein at least one cooling water passage forming core has an opening forming portion and a bottom bypass hole forming portion. And a core for forming a thermostat housing, which has at least one, and a core for forming a bypass passage, which has a connecting portion forming portion, are integrally provided for at least one other core for forming a cooling water passage, and these two cooling water passages are formed. The core for forming the thermostat housing, the portion for forming the opening of the core for forming the thermostat housing, the portion for forming the bottom bypass hole, the portion for forming the connecting portion of the core for forming the bypass passage, and the lower baseboard of the bypass passage along the longitudinal direction. The thermostat housing forming core and the bypass are positioned so that the bottom bypass hole forming portion and the connecting portion forming portion are overlapped with each other. A cooling water passage formation of a cylinder head, characterized in that a load applied to the passage forming core is supported by the bypass passage lower skirting board through an overlapping surface of the bottom bypass hole forming portion and the connecting portion forming portion. Method. 2. The opening forming portion and the bottom bypass hole forming portion of the thermostat housing forming core, and the connecting portion forming portion of the bypass passage forming core and the bypass passage lower skirting board are arranged along a vertical direction. The method for forming a cooling water passage of a cylinder head according to claim 1, wherein the cooling water passage is located. 3. A cooling water passage forming core having a thermostat housing forming core integrally provided thereon is placed on the upper side, and a bypass passage forming core having an integrally provided cooling water passage forming core being placed on the lower side. 3. The cylinder head according to claim 1 or 2, wherein the bottom bypass hole forming portion of the thermostat housing forming core and the connecting portion forming portion of the bypass passage forming core are overlapped so as to be in contact with each other. Method for forming cooling water passage. 4. A pressing surface formed in an opening forming portion of a thermostat housing forming core, an overlapping surface of a bottom bypass hole forming portion and a connecting portion forming portion of a bypass passage forming core, and a bypass passage lower skirting board. 4. The method for forming a cooling water passage for a cylinder head according to claim 1, wherein the support lower surfaces of the above are substantially parallel to each other. 5. A cooling water passage forming core integrally provided with a thermostat housing forming core having an opening forming portion and a bottom bypass hole forming portion, and a bypass passage forming core having a connecting portion forming portion. A core for cooling water passage formation of a cylinder head, in which another core for cooling water passage formation integrally provided with a core is stacked, and a cooling water passage is formed in a plurality of separate parts. At one end of the cooling water passage forming core, a thermostat housing forming core is provided so that the bypass hole forming portion faces the inside and the opening forming portion faces the outside, and the other cooling water passage forming core. A bypass passage core is provided at one end of the bent portion so that an inwardly curved portion is formed and a connection portion forming portion is located at the tip end side of the curved portion, and a skirting board support portion is provided at an outer portion of the curved portion. Establishment The bottom bypass hole forming portion and the connecting portion forming portion are overlapped with each other, and the load direction applied between the outside surface of the opening forming portion and the outside supporting surface of the skirting board connected to the skirting board supporting portion. A core for forming a cooling water passage of a cylinder head, characterized in that the opening forming portion, the bypass hole forming portion, the connecting portion forming portion, the skirting board support and the skirting board outer supporting surface are located substantially along the line. .