JPH10220286A - Cooling structure of metal-mold-cast cylinder head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate burrs from a first cooling medium passage so as to improve a cooling efficiency by forming an inner surface of the first cooling medium passage in a wave cross sectional shape on an end opened toward at least the first cooling medium passage of third cooling medium passages. SOLUTION: The inner surface of a first cooling medium passage 23 is formed in a wave cross sectional shape on an end opened toward the first cooling medium passage 23 of third cooling medium passages 251 , 252 . The opening end is formed discontinuously in a circumferential direction on a plane surface perpendicular to the advance direction of a drill tool for drilling on the third cooling medium passages 251 , 252 , in the end opened toward the first cooling medium passage 23 of third cooling medium passages 251 . Burrs generated at the time of drill work are comparatively small. As a result, the burrs can be eliminated not only from the first cooling medium passage 23 but also from a second cooling medium passage 24 side, so that then can easily eliminated by means of air blow and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a die-cast cylinder head such as an aluminum die-cast, and more particularly, to a first cooling medium extending along a cylinder arrangement direction above a plurality of recesses for forming combustion chambers. A passage, a second coolant passage surrounding the combustion chamber recess and opening to the lower surface of the cylinder head, and a third coolant passage connecting between the first and second coolant passages between the cylinders are provided in the cylinder head. The present invention relates to a cooling structure for a die-cast cylinder head, wherein the first and second cooling medium passages are formed by a core, and the third cooling medium passage is formed by machining.

[0002]

2. Description of the Related Art Conventionally, such a cooling structure is already known, for example, from Japanese Utility Model Publication No. 1-188814.

[0003]

When the third cooling medium passage connecting the first and second cooling medium passages is formed by machining from the side of the second cooling medium passage, the first cooling medium passage is first formed. It is inevitable that burrs are generated at the end on the side of the cooling medium passage, and it is necessary to remove burrs from the first cooling medium passage. However, in the above-described conventional case, the first cooling medium passage has a smooth circular shape. Since the third cooling medium passage is formed of a core having an outer surface with a cross-sectional shape, burrs are formed in an annular manner at the opening end of the third cooling medium passage on the first cooling medium passage side. Was difficult to remove.

The present invention has been made in view of the above circumstances, and facilitates removal of burrs generated from the first cooling medium passage accompanying the formation of the third cooling medium passage by machining, and then performs cooling. It is an object of the present invention to provide a cooling structure for a die-cast cylinder head that improves efficiency.

[0005]

According to a first aspect of the present invention, there is provided a cylinder head having a cylinder formed above a plurality of combustion chamber forming recesses which are open to the lower surface of the cylinder head. A first cooling medium passage extending along the arrangement direction, a second cooling medium passage surrounding the combustion chamber recess and opening to the lower surface of the cylinder head, and a first cooling medium passage between the cylinders. A third cooling medium passage formed between the second cooling medium passage and the second cooling medium passage after the molding of the cylinder head. In the cooling structure of the cylinder head made of die casting, which is formed by machining, the inner surface of the first coolant passage at least at the open end of the third coolant passage to the first coolant passage has a corrugated cross-sectional shape. Characterized in that it is formed so as to.

According to the first aspect of the present invention, the inner surface of the first cooling medium passage has a corrugated cross-sectional shape at the opening end of the third cooling medium passage to the first cooling medium passage. Is formed, so that at the open end of the third cooling medium passage to the first cooling medium passage, the opening end is formed in a circumferential direction at a plane perpendicular to the traveling direction of the drilling tool for forming the third cooling medium passage. The burrs generated by the machining with the drilling tool are discontinuous and do not continue in an annular shape, but are separated and relatively small. Therefore, burrs can be removed not only from the first cooling medium passage but also from the second cooling medium passage via the third cooling medium passage, and burrs relatively small by air blow or the like can be easily removed. It becomes possible. Moreover, since the first cooling medium passage has at least a part of the inner surface of the waveform, the contact area between the cylinder head and a cooling medium such as cooling water flowing through the first cooling medium passage can be relatively increased. It is possible to improve the cooling efficiency.

According to a second aspect of the present invention,
In addition to the configuration of the first aspect of the present invention, the height of the second cooling medium passage from the lower surface of the cylinder head is larger than that of the other portion of the second cooling medium passage in the portion corresponding to each cylinder. The third cooling medium passage connecting the first and second cooling medium passages is relatively short by providing a lower end of the third cooling medium passage in the recess. The time required for machining the passage can be reduced, and the second opening formed on the lower surface of the cylinder head can be reduced.
Only the portion corresponding to the third cooling medium passage is deepened in the cooling medium passage, and the tightening of the cylinder head and the cylinder block is performed because the depth of the second cooling medium passage is relatively small in other portions. A decrease in attachment rigidity can be prevented.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIGS. 1 to 7 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a cylinder head, taken along line 1-1 of FIG. 2, and FIG. 3 is a sectional view taken along line 3-3 of FIG. 2, FIG. 4 is a transverse sectional view of the cylinder head taken along line 4-4 of FIG. 3, FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is an enlarged view of a part viewed from the arrow 6 in FIG. 2, and FIG.
FIG. 7 is a sectional view taken along line 7.

Referring first to FIGS. 1 and 2, this cylinder head 10 is formed for a four-cylinder internal combustion engine by die casting such as aluminum die casting. Four combustion chamber forming recesses 1 for forming corresponding combustion chambers
Are provided so as to open to the lower surface of the cylinder head 10. Further, the cylinder head 10 is provided with an intake port 12 corresponding to each of the combustion chamber forming recesses 11 and an exhaust port 13 corresponding to each of the combustion chamber forming recesses 11. And a direction perpendicular to the arrangement direction of the cylinders, that is, the cylinder head 1
0 are opened on one first side surface 10a along the width direction 0, and each exhaust port 13 is opened on the second side surface 10b of the cylinder head 10 on the other side along the width direction. Is done.

The cylinder head 10 has a pair of intake passages 14 connecting each intake port 12 and each combustion chamber forming recess 11, a pair of exhaust ports 13 and each combustion chamber forming recess. A pair of exhaust passages 15 that connect between
Are provided, and the recesses 11 for forming the combustion chambers of the respective intake passages 14 are provided.
, An exhaust valve seat member 16 is provided at an opening end of each exhaust passage 15 to the combustion chamber forming recess 11.

Further, the cylinder head 10 has a plurality of plug mounting holes 18 for mounting the spark plugs (not shown) so that the tips of the spark plugs (not shown) can be inserted into the recesses 11 for forming the combustion chambers. A guide cylinder 19 for guiding an intake valve (not shown) that can be seated on the valve seat members 16.
Are press-fitted into each of the two cylinders for press-fitting, and guide cylinders 21 for guiding exhaust valves (not shown) that can be seated in the respective valve seat members 17 for exhaust valves. And two press-fitting holes 22 are provided for each cylinder so as to press-fit the holes.
Are perforated by machining after die casting of the cylinder head 10.

Referring to FIG. 3, FIG. 4 and FIG.
A first cooling medium passage 23, a second cooling medium passage 24 opened on the lower surface of the cylinder head 10, and a first cooling medium passage 24 for allowing a cooling medium such as cooling water to flow through the cylinder head 10.
And a plurality of third cooling medium paths connecting between the second cooling medium passages 23 and 24.
Cooling medium passages 25 ₁ ..., 25 ₂ ... and are provided first and second cooling medium passages 23, 24 cylinder head 10
To cast the at the time of molding are those formed by the core of the third cooling medium passages 25 ₁ ..., 25 ₂ ... are machined from the second cooling medium passage 24 side after casting of the cylinder head 10 It is formed.

The first cooling medium passages 23 are formed at the center of the cylinder head 10 in the width direction at the respective recesses 11 for forming the combustion chambers.
The cylinder head 1 is formed so as to extend along the direction in which the cylinders are arranged.
0, one end of the first cooling medium passage 23 is opened,
At the other end of the cylinder head 10 along the cylinder arrangement direction, a first
The other end of the cooling medium passage 23 is closed. Thus, a lid member (not shown) for closing one end of the first cooling medium passage 23 is fastened to the cylinder head 10. The first cooling medium passage 23 is formed by extracting the core to one end side along the cylinder arrangement direction of the cylinder head 10 during casting of the cylinder head 10, and is formed to have a draft angle. ing.

The second cooling medium passage 24 surrounds each of the combustion chamber forming recesses 11.
0 is formed endlessly on the lower surface of the cylinder 0, and a plurality of recesses 24a are arranged in pairs corresponding to portions between the cylinders.
However, the height from the lower surface of the cylinder head 10 is set to be larger than other portions of the second cooling medium passage 24, and the cylinder head 10 is provided in the second cooling medium passage 24. The first and second cooling medium passages 2 are provided at one end of the cylinder head 10 along the cylinder arrangement direction.
A communication passage 26 connecting between the first and second cooling medium passages 23 and 24 at the other end of the cylinder head 10 along the cylinder arrangement direction extends vertically. The communication passages 26, which are provided in the head 10, are provided in a core forming the second cooling medium passage 24.
A pin-shaped part forming 27 is provided integrally. That is, the two communication passages 26 and 27 are also formed by the core when the cylinder head 10 is molded.

A third cooling system in which the lower ends of the recesses 24a... Arranged on the first side surface 10a side of the cylinder head 10 with respect to the center line connecting the centers of the cylinders are opened at the lower ends and the upper ends are opened in the first cooling medium passage 23. Medium passage 25
₁ ... is, the inclined so as to approach the center line side provided in the cylinder head 10, also the lower end in a recess 24a ... arranged in the second side surface 10b side of the cylinder head 10 with respect to the center line as directed upward Are formed in the cylinder head 10 such that the third cooling medium passages 25 ₂ .. These third cooling medium passages 25 ₁ ... 25 ₂
Are drilled by the drilling tool 30 after the cylinder head 10 is formed by casting, as shown in FIG.

Referring also to FIG. 7, the first cooling medium passage 23 has, for example, a substantially triangular cross-sectional shape whose width is narrowed downward.
Are formed on the inner surfaces on both sides of the first cooling medium 23, and arc-shaped convex portions 28 extending along the longitudinal direction of the first cooling medium passage 23, and in the longitudinal direction of the first cooling medium passage 23. Are formed so as to be alternately continuous with arc-shaped concave grooves 29 extending along. Thus, the third cooling medium passages 25 ₁ .
25 ₂ ... an upper end of the, which is open on both sides the inner surface of the first cooling medium 23, the third cooling medium passage 25 ₁ ..., 25 ₂
Are formed so that the inner surface of the first cooling medium passage 23 has a corrugated cross-sectional shape at the opening end to the first cooling medium passage 23.

Next, the operation of this embodiment will be described.
And the third cooling medium passage 25₁…, 25 _TwoThe first cooling medium
At the open end to the body passage 23, it has a corrugated cross-sectional shape.
That the inner surface of the first cooling medium passage 23 is formed
As a result, the third cooling medium passage 25 ₁…, 25_TwoThe first cold
At the open end to the cooling medium passage, the third cooling medium passage 25
₁…, 25_TwoOf drilling tool 30 for drilling ...
The opening ends are discontinuous in the circumferential direction on a plane perpendicular to the direction.
Therefore, the third cooling medium passage 25 by the drilling tool 30 ₁
…, 25_TwoBurrs generated during drilling of…
It will not be broken down and will be relatively small.
As a result, the relatively small burr is removed from the first cooling medium passage.
From the second cooling medium through the third cooling medium passage.
Air blow can be removed from the passage side
For example, the burrs can be easily removed.

Moreover, since the first cooling medium passage 23 has at least a part of an inner surface whose cross section is corrugated, the contact area of the cylinder head 10 with a cooling medium such as cooling water flowing through the first cooling medium passage 23 is formed. And the cooling efficiency of the cylinder head 10 with the cooling medium can be improved.

In the portion corresponding to each cylinder, the second cooling medium passage 24 has a recess 24a whose height from the lower surface of the cylinder head 10 is larger than other portions of the second cooling medium passage 24. The third cooling medium passage 25
₁ ..., 25 since ₂ ... lower end of which is open to the recess 24a ..., the third cooling medium passage 25 ₁ ..., 25 ₂ ... relatively short, the third cooling medium passage 25 ₁ ..., 25 ₂ ... of It is possible to reduce the time required for machining. Moreover, even in the so-called open deck type cylinder head 10 in which the second cooling medium passage 24 is opened on the lower surface of the cylinder head 10, the second cooling medium passage 24 is connected to the third cooling medium passage 25.
₁ , 25 ₂ , etc., only the portion corresponding to the cylinder head 10 and the cylinder block (not shown) is relatively deep in the other portions, since the second cooling medium passage 24 is relatively shallow. ) Can be prevented from lowering.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, the entire inner peripheral surface of the first cooling medium passage 23 may be formed so as to have a corrugated cross section, so that the cooling efficiency can be further improved.

[0023]

As described above, according to the first aspect of the present invention, the first cooling medium passage has a corrugated cross-sectional shape at the opening end of the third cooling medium passage to the first cooling medium passage. By forming the inner surface, burrs generated by machining with the drilling tool are made relatively small, so that the burrs can be easily removed, and the cooling medium flowing through the first cooling medium passage and the cylinder head can be removed. And the cooling area can be improved by making the contact area relatively large.

According to the second aspect of the present invention, the third cooling medium passage can be made relatively short so that the time required for machining the third cooling medium passage can be shortened. (2) Despite the opening of the cooling medium passage, the tightening rigidity of the cylinder head and the cylinder block can be prevented from lowering.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a cylinder head, taken along line 1--2 of FIG.
It is a 1-line sectional view.

FIG. 2 is a bottom view as viewed in the direction of arrow 2 in FIG.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view of the cylinder head taken along line 4-4 in FIG.

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is an enlarged view of a part viewed from an arrow 6 in FIG. 2;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6;

[Explanation of symbols]

10 ... cylinder head 11 ... combustion chamber forming recess 23 ... first cooling medium passages 24 ... second cooling medium passage 24a ... recess 25 _1, 25 ₂ ... third cooling medium aisle

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masafumi Murata 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Toshiya Sonoda 1-4-1 Chuo, Wako-shi, Saitama Inside Honda R & D Co., Ltd. (72) Inventor Masatake Kanahiro 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside Honda R & D Co., Ltd.

Claims (2)

[Claims] 1. A first cooling medium passage extending in a cylinder arrangement direction above a plurality of combustion chamber forming recesses (11) opening toward a lower surface of the cylinder head (10). (23) and each of the combustion chamber recesses (1).
A second cooling medium passage (24) surrounding the 1) and opening to the lower surface of the cylinder head (10), and a third cooling medium passage connecting between the first and second cooling medium passages (23, 24) between the respective cylinders. (25 ₁ , 25 ₂ ) are provided, the first and second cooling medium passages (23, 24) are formed by the core during the casting of the cylinder head (10), and the third cooling medium passage (25 ₁ ) is formed. , 25 ₂ ) formed by machining from the side of the second cooling medium passage (24) after casting, in a cooling structure of a die-cast cylinder head, at least a third cooling medium passage (25 ₁ , 25 ₂ ). Cooling the metal casting cylinder head, wherein an inner surface of the first cooling medium passage (23) has a corrugated cross-sectional shape at an open end to the first cooling medium passage (23). Construction. 2. A second cooling medium at a portion corresponding to between the cylinders.
In the passage (24), from the lower surface of the cylinder head (10)
Is larger than the other part of the second cooling medium passage (24).
And a third cooling medium passage.
(25₁, 25 _Two) Is open to the recess (24a).
2. The mold casting mold according to claim 1, wherein
Head cooling structure.