JP2789150B2 - Semi-finished cylinder block, method of manufacturing cylinder block, and mold for semi-finished cylinder block - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cylinder block body having at least a pair of journal walls integrally formed therein, in which a cylinder sleeve is cast so that an end face of the cylinder case faces the pair of journal walls. The present invention relates to a semi-finished cylinder block, and further relates to a manufacturing method and a mold for manufacturing the cylinder block.

[0002]

2. Description of the Related Art Conventionally, this type of cylinder block has been disclosed in Japanese Utility Model Laid-Open No. 55-104740 or Japanese Patent Publication No. 58-104740.
What is described in -31460 is publicly known.

[0003]

By the way, when such a cylinder block is cast, when the molten metal in the cylinder block body in which the cylinder sleeve is cast is solidified and contracted, the shrinkage rate of the molten metal near the journal wall having a large mass is reduced. Is relatively large, whereas the shrinkage of the molten metal at a portion away from the journal wall is relatively small. When the contraction rate of the molten metal in the cylinder block body surrounding the cylinder sleeve becomes unbalanced in the circumferential direction, there is a problem that the solidification contraction force deforms the bore of the cylinder sleeve into an elliptical shape.

The present invention has been made in view of such circumstances, and has as its object to prevent deformation of a cylinder sleeve when the cylinder sleeve is cast into a cylinder block body.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a cylinder block body having at least a pair of journal walls integrally formed therein, and a cylinder sleeve having a crankcase-side end face having the pair of journal walls. A cylinder block semi-finished product cast so as to face between the walls, and a bridge portion extending in a direction intersecting a direction connecting the pair of journal walls so as to bridge a crankcase side end surface of the cylinder sleeve. The first feature is that they are integrally formed.

According to the present invention, there is provided a cylinder block in which a cylinder sleeve is cast into a cylinder block body integrally having at least a pair of journal walls such that an end surface on a crankcase side faces between the pair of journal walls. In the manufacturing method, when the cylinder sleeve is cast into the inside of the cylinder block body, a bridge portion extending in a direction intersecting a direction connecting the pair of journal walls is bridged so as to bridge a crankcase side end surface of the cylinder sleeve. The second feature is that the bridge portion is cut off after the cylinder block body solidifies.

The present invention also provides a cylinder block half having a cylinder sleeve cast inside a cylinder block body integrally having at least a pair of journal walls such that an end surface on a crankcase side faces between the pair of journal walls. In a mold for molding a product, which is a mold for molding the inner surface of the crankcase of the cylinder block body, a bridging portion extending in a direction intersecting a direction connecting the pair of journal walls so as to bridge the end surface of the cylinder sleeve on the crankcase side. A third feature is that the groove is formed integrally.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show a finished product of a cylinder block 1 of a multi-cylinder internal combustion engine (in the embodiment, an in-line four-cylinder internal combustion engine). The cylinder block 1 comprises a cylinder block main body 2 made of an aluminum alloy and a cast iron. And a cylinder sleeve assembly 3 made of stainless steel. The cylinder block body 2
A cylinder barrel assembly 4 formed by casting the cylinder sleeve assembly 3, an outer wall 5 surrounding the cylinder barrel assembly 4, and a crankcase connected to lower ends of the cylinder barrel assembly 4 and the outer wall 5. 6 and five journal sections 7. A water jacket 8 is formed between the cylinder barrel assembly 4 and the outer wall 5.

The cylinder sleeve assembly 3 is formed by connecting four cylindrical cylinder sleeves 3 ₁ to each other over the entire length of each bus bar, and the center lines of the cylinder bores 9 of each cylinder sleeve 3 ₁ . Are arranged so as to be located on the same plane. Figure 2, as is apparent from FIGS. 4 and 14, the outer surface of the cylinder sleeve assembly 3, ridges 3 ₁₁ ... and the concave stripes 3 ₁₂ circumferentially extending ... are formed alternately in the axial direction . A plurality of projections 3 ₁₃ parallel to each other protrude outward from the concave ridges 3 ₁₂ near the connecting portion of the adjacent cylinder sleeves 3 ₁ , and the tip of each projection 3 ₁₃ is a ridge 3 _11. ... extends outside the top.

FIGS. 5 to 9 show a molding die 10 for die-casting the cylinder block 1. FIG.
The molding die 10 includes an upper movable die 12 and a lower movable die 1 that can move up and down so as to be able to approach and separate from each other.
3 and a side surface movable mold 14 that can be moved laterally with respect to the fixed mold 11, the upper surface movable mold 12, and the lower surface movable mold 13. Together forming surface 11 ₁ for molding an inner surface of the crankcase 6 is formed in the fixed die 11, the upper surface mobile 12
Molding surfaces 12 ₁ and 13 ₁ for molding the outer surface of the crankcase 6 are formed on the lower surface movable die 13. The sides in the moving mold 14, the four bore pin 14 ₁ ... cylindrical of the cylinder sleeve assembly 3 is fitted held water jacket pin for forming a water jacket 8 1
4 ₂ is projecting. A runner 15 for injecting molten metal is formed between the fixed die 11 and the lower surface movable die 13.

As is apparent from FIGS. 5 and 6, three first bridge forming grooves 14 ₃ ... Are formed in the side moving die 14 so as to cross between the four bore pins 14 ₁ . The cavities forming the cylinder barrel assembly 4 are communicated with each other on the cylinder head side end surface of the cylinder sleeve assembly 3 by the first bridge portion forming grooves 14 ₃ . Also,
Each bridge portion forming groove 14 ₃ ..., each two ejector pin 14 _4, 14 ₄ of the tip faces.

As is apparent from FIGS. 5 and 7, four second bridge forming grooves 11 ₂ are formed in the fixed die 11 so as to cross the center of the four cylinder bores 9 in the diameter direction. The cavities forming the cylinder barrel assembly 4 communicate with each other at the end surface of the cylinder sleeve assembly 3 on the crankcase 6 side by the second bridge portion forming grooves 11 ₂ .

FIGS. 10 to 13 show a cylinder block semi-finished product 1 'taken out of the molding die 10. FIG.
The cylinder block semi-finished product 1 ′ has three first bridge portions 16 formed by the first bridge portion forming grooves 14 ₃ ... On the cylinder head side end surface of the cylinder sleeve assembly 3.
... are provided integrally. Also, four second bridge portions 18 formed by the second bridge portion forming grooves 11 ₂ are integrally formed on the end surface of the cylinder sleeve assembly 3 on the crankcase 6 side of the cylinder block semi-finished product 1 ′. You.

Next, the above-mentioned cylinder block casting process will be described.

[0016] First, after fitting the cylinder sleeve assembly 3 in the bore pin 14 _first side mobile 14 of the mold 10 as shown in FIG. 5, the fixed mold 11 as shown in FIG. 8, top mobile 12 Then, the lower surface moving die 13 and the side surface moving die 14 are clamped. Subsequently, the molten metal is injected into the cavity through a runner 15 formed between the fixed die 11 and the lower surface movable die 13. At this time, the plating applied to the cylinder sleeve assembly 3 is melted by the molten metal and alloying occurs with the molten metal, and the adhesion between the cylinder sleeve assembly 3 and the cylinder barrel assembly 4 is improved.

When the molten metal solidifies, the mold 10 is opened as shown in FIG. 9 to separate the cylinder block semi-finished product 1 '. Three first bridge portions 16 are integrally formed on the cylinder head side end surface of the cylinder sleeve assembly 3 cast into the cylinder block semi-finished product 1 ', and four first bridge portions 16 are formed on the crankcase 6 side end surface. The second bridge portions 18 are integrally formed. The first bridge portions 16 and the second bridge portions 18 formed integrally with the cylinder block semi-finished product 1 'are cut off by machining to complete the cylinder block 1.

Next, the first bridging portion 16 at the time of casting is used.
Will be described with reference to FIG.

In the die casting of the cylinder block 1, the molten metal 19 of the aluminum alloy injected into the cavity of the molding die 10 solidifies and contracts with cooling. When the molten metal 19 of the cylinder barrel assembly 4 covering the outer periphery of the cylinder sleeve assembly 3 solidifies and contracts, the contraction force generally acts to bring the cylinder barrel assembly 4 into close contact with the cylinder sleeve assembly 3. In a specific area indicated by A in FIG. 14, the contraction force acts to separate the cylinder barrel assembly 4 from the cylinder sleeve assembly 3. That is, the arrow a is displayed in the area A of the cylinder barrel assembly 4.
When the coagulation / shrinkage force as shown by (1) acts, this coagulation / shrinkage force acts to generate a gap between the cylinder barrel assembly 4 and the cylinder sleeve assembly 3 by pulling the cylinder barrel assembly 4 outward.

However, the cylinder sleeve assembly 3
Of the cylinder barrel assembly 4 located on both sides of the cylinder 19
Are connected to each other via a first bridge portion 16, and a coagulation contraction force indicated by an arrow b also acts on the first bridge portion 16. The solidification contraction force acting on the first bridge portion 16 in the direction of arrow b opposes the solidification contraction force acting on the cylinder barrel assembly 4 in the direction of arrow a. Cylinder sleeve assembly 3
This prevents pressure leakage from the combustion chamber to the crankcase 6 and improves the heat transfer from the cylinder sleeve assembly 3 to the cylinder barrel assembly 4 to improve the cooling performance. be able to.

In the case where a large number of projections 3 ₁₃ are formed on the outer periphery as in the cylinder sleeve assembly 3 of the present embodiment, stress concentrates on the projections 3 ₁₃ when the molten metal 19 solidifies and contracts. However, the stress can be dispersed by the action of the first bridge portions 16.

Next, at the time of casting, the second bridge 18
Will be described with reference to FIG.

When the molten metal 19 of the aluminum alloy injected into the cavity of the mold 10 cools, the contraction rate of the molten metal 19 of the cylinder barrel assembly 4 located on the outer periphery of the cylinder sleeve assembly 3 becomes uneven in the circumferential direction. Become. That is, in the molten metal 19 of the cylinder barrel assembly 4, a portion adjacent to the journal portion 7 having a large mass has a large contraction rate, whereas a portion away from the journal portion 7 has a small contraction rate. As a result, solidification shrinkage force shown by the arrow c is generated in the molten metal 19 of the cylinder barrel assembly 4 located on the outer periphery of the cylinder sleeve assembly 3, the respective cylinder sleeves 3 ₁ of this solidification shrinkage force cylinder sleeve assembly 3 , So as to be deformed into a vertically long elliptical shape in a direction orthogonal to the arrangement direction.

However, since the molten metal 19 of the cylinder barrel assembly 4 is connected to each other through the second bridge 18, a solidification contraction force indicated by an arrow d acts on the second bridge 18, and this arrow 19 d direction of solidification shrinkage force is opposed to the solidification shrinkage force of the arrow c direction to try to deform the cylinder sleeve 3 ₁ vertically long elliptical. Thus, it is possible to prevent deformation of the cylinder sleeve assembly 3 and maintain the roundness of the cylinder bore 9.

The planar shape and cross-sectional shape of the second bridge 18 can be appropriately changed based on the magnitude and direction of the solidification contraction force of the molten metal 19, and various modifications as shown in FIG. 16 can be considered. In addition to the one shown in FIG. 16, it is also possible to provide two bridge portions 18 in one cylinder, or not to provide the bridge portion 18 in a specific cylinder.

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 small design changes can be made.

For example, in the embodiment, a multi-cylinder internal combustion engine is illustrated, but the present invention can be applied to a single-cylinder internal combustion engine.

[0028]

As described above, according to the first or third aspect of the present invention, when the cylinder sleeve is cast into the cylinder block body, the cross section of the cylinder sleeve is formed into an elliptical shape due to the solidification contraction force of the molten metal. Is prevented by the action of the bridging portion formed by the bridging portion forming groove provided in the mold. Thus, the accuracy of the cylinder block can be improved while maintaining the circularity of the cylinder sleeve.

According to the second feature of the present invention, the roundness of the cylinder sleeve can be maintained by the bridging portion, and the finished product of the cylinder block which does not hinder use by cutting off the bridging portion. Can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall plan view of a completed cylinder block.

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

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 1;

FIG. 5 is a sectional view of a mold for forming a cylinder block.

FIG. 6 is a view taken along line 6-6 of FIG. 5;

7 is a view in the direction of arrows in FIG. 5;

FIG. 8 is a diagram showing a state in which a molding die is clamped.

FIG. 9 is a view showing a state in which a mold is opened.

FIG. 10 is a sectional view of a semi-finished product of a cylinder block.

11 is a sectional view taken along line 11-11 of FIG. 10;

FIG. 12 is a view taken in the direction of arrow 12 in FIG. 10;

FIG. 13 is a view in the direction of arrow 13 in FIG. 10;

FIG. 14 is an explanatory diagram of an operation of a first bridge portion.

FIG. 15 is an explanatory diagram of an operation of a second bridge portion.

FIG. 16 is a view showing a modification of the second bridge portion.

[Explanation of symbols]

2 Cylinder block main body 3 ₁ Cylinder sleeve 6 Crank case 7 Journal wall 11 Fixed type (mold) 11 ₂ Second bridge portion forming groove (bridge portion forming groove) 18 Second bridge portion (bridge portion)

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tomoyuki Goto 1907, Hirata-cho, Suzuka-shi, Mie Honda Motor Co., Ltd. Suzuka Works (56) References JP-A-3-118952 (JP, A) JP-A-3 169 454 (JP, A) Japanese Utility Model 2-139343 (JP, U) Japanese Utility Model 63-79451 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 19/08 F02F 1/00

Claims (3)

(57) [Claims] An inside of a cylinder block body (2) having at least a pair of journal walls (7) integrally, a cylinder sleeve (3 ₁ ) having an end face on a crankcase (6) side is provided with the pair of journal walls (7). ) a cylinder block blank composed by casting so as to face between, so as to bridge the crankcase (6) side end surface of the cylinder sleeve (3 _1), intersecting the direction connecting the pair of journal walls (7) A semi-finished product of a cylinder block, wherein a bridge portion (18) extending in the direction of movement is formed integrally with the cylinder block body (2). 2. A cylinder sleeve (3 ₁ ) having an end face on a crankcase (6) side inside a cylinder block body (2) integrally having at least a pair of journal walls (7). ) In the method of manufacturing a cylinder block cast in such a way that the cylinder sleeve (3 ₁ ) is cast into the cylinder block body (2) when the cylinder sleeve (3 ₁ ) is cast into the cylinder block body (2).
A bridge portion (18) extending in a direction intersecting with a direction connecting the pair of journal walls (7) is formed integrally with the cylinder block body (2) so as to bridge an end surface of the cylinder block (6). A method for manufacturing a cylinder block, comprising cutting off the bridging portion (18) after the main body (2) has solidified. 3. A cylinder sleeve (3 ₁ ) having at least one pair of journal walls (7) integrally provided inside a cylinder block body (2) having an end face on the crankcase (6) side facing the pair of journal walls (7). ) the die cylinder block blank composed by casting so as to face in between the mold (11) for molding a crank case (6) the inner surface of the cylinder block body (2), cylinder sleeve (3 ₁₎
A cross-linking portion forming groove (11 ₂ ) extending in a direction intersecting with a direction connecting the pair of journal walls (7) so as to cross-link an end surface on the side of the crankcase (6). Mold for block semi-finished products.