JP2554835Y2 - Mold used for the production of sand mold for cylinder sleeve assembly casting - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold used for manufacturing a sand mold for casting a cylinder sleeve assembly of a cylinder block for a multi-cylinder internal combustion engine.

[0002]

2. Description of the Related Art Heretofore, as this kind of cylinder sleeve assembly, there has been known a cylinder sleeve assembly in which a plurality of circumferentially extending ridges are arranged at predetermined intervals along a generatrix direction on an outer peripheral surface of a peripheral wall of each cylinder sleeve. (See Japanese Utility Model Laid-Open No. 55-104740).

[0003] One of the reasons for providing the above-mentioned ridges is to increase the contact area of the cylinder sleeve assembly to improve the adhesion of the cylinder sleeve assembly to the cylinder barrel assembly. In a specific region, the ridge does not contribute to improving the adhesion between the cylinder barrel assembly and the cylinder sleeve assembly.

That is, as described above, when the adjacent two cylindrical peripheral walls of the plurality of cylinder sleeves are connected to each other, the outer peripheral surface of the cylinder sleeve assembly has valley regions on both sides of the connecting portion of the two cylindrical peripheral walls. Will have.

In a cylinder block casting mold provided with a cylinder sleeve assembly having such a structure, molten metal is poured into a cylinder barrel assembly molding cavity formed between the cylinder sleeve assembly and a water jacket molding core. Upon injection, there is a tendency for the molten metal present in the region facing the valley region to solidify more slowly than in the other regions. Therefore, a coagulation contraction force in the circumferential direction acts on the valley region-facing portion of the cylinder barrel assembly. However, since the ridge cannot counter this coagulation-shrinkage force, shrinkage occurs in the valley region-facing portion. Therefore, the adhesion between the opposing portion and the valley region is deteriorated.

Therefore, the present inventors have developed a cylinder sleeve assembly that can suppress the shrinkage of the cylinder barrel assembly at the valley region facing portion and improve the adhesion between the facing portion and the valley region. A plurality of cylinder sleeves adjacent to each other are connected to each other so as to be cast into a cylinder barrel assembly of a cylinder block for a multi-cylinder internal combustion engine, and the cylinder sleeves existing on both sides of a connection portion of the both peripheral walls are formed. In each valley region of the outer peripheral surface of the aggregate, a cylinder sleeve aggregate provided with a plurality of shrinkage suppressing protrusions that bite into the cylinder barrel aggregate during cylinder block casting so as to protrude substantially radially from each cylindrical peripheral wall. developed.

According to this cylinder sleeve assembly, it is possible to obtain the shrinkage suppressing action of each projection and improve the adhesion between the valley region facing portion of the cylinder barrel assembly and the valley region of the cylinder sleeve assembly. it can.

[0008]

The cylinder sleeve assembly is manufactured through a casting process. In the production of the sand mold, each shrinkage suppressing projection projects substantially radially from each cylindrical peripheral wall. Because of this, the sand mold can be smoothly released unless special measures are taken between each projection casting recess formed in the sand mold and each projection mold of the molding die forming the recess. Disappears.

In view of the above, an object of the present invention is to provide a molding die capable of smoothly releasing a sand mold having a concave portion for casting a projection.

[0010]

According to the present invention, two adjacent cylindrical peripheral walls of a plurality of cylinder sleeves are connected to each other so as to be cast into a cylinder barrel assembly of a cylinder block for a multi-cylinder internal combustion engine. In each of the valley-shaped regions on the outer peripheral surface of the cylinder sleeve assembly existing on both sides of the joint portion of the two peripheral walls, a plurality of shrinkage suppressing protrusions that bite into the cylinder barrel assembly during the cylinder block casting are substantially formed from each cylindrical peripheral wall. A molding die for producing a sand mold for casting a cylinder sleeve assembly provided so as to protrude in a radial direction, comprising a molding die constituent part for molding a mountain-shaped inner surface of the sand mold corresponding to the valley region, A plurality of projection casting recesses are formed on the inner surface of the chevron, and a plurality of projections detached from the recesses are provided prior to the release of the sand mold.

[0011]

1 and 2 show a cylinder block 1 for a multi-cylinder, in the illustrated example, a four-cylinder in-line type internal combustion engine. The cylinder block 1 is composed of an aluminum alloy cylinder block body 2 and a cast iron cylinder sleeve assembly. It consists of three.
The cylinder block body 2 includes a cylinder sleeve assembly 3
The cylinder barrel assembly 4 is formed by molding an outer wall 5 surrounding the cylinder barrel assembly 4, and a crankcase 6 connected to one end of the outer wall 5. A water jacket 7 is formed between the cylinder barrel assembly 4 and the outer wall 5.

3 to 5, a plurality of cylinder sleeve assemblies 3 in which the center lines of the respective cylinder bores 8 are arranged in parallel with each other, in the illustrated example, four cylinder sleeves 3 ₁ to 3 are shown.
3 ₄ phases Tonariru between both cylindrical peripheral wall 9 mutual those bound over the generatrix direction length.

[0013] The circumferential wall 9 the outer peripheral surface of the cylinder sleeve 3 ₁ to 3 ₄ are a plurality of ridges 10 extending in the circumferential direction, are arranged at predetermined intervals over the generatrix direction substantially the entire length. These ridges 10 prevent the cylinder sleeve assembly 3 from coming off the cylinder barrel assembly 4 and improve the adhesion between the cylinder barrel assembly 4 and the cylinder sleeve assembly 3 by increasing the contact area of the cylinder sleeve assembly 3. It is provided for the purpose.

In the outer peripheral surface of the cylinder sleeve assembly 3, in each of the valley regions A on both sides of the joint portion 11 of the adjacent cylindrical peripheral walls 9, a plurality of pits that bite into the cylinder barrel assembly 4 when the cylinder block 1 is cast. The shrinkage suppression projections 12
It is provided so as to be located on each concave strip 13 adjacent to each convex strip 10. Each of the projections 12 protrudes from the bottom surface of each of the concave ridges 13 in a substantially radial direction with a predetermined interval between adjacent ones, and the tip of each of the projections 12 is located radially outward of each of the convex ridges 10. I do. These projections 12 are formed simultaneously with the casting of the cylinder sleeve assembly 3.

Here, the valley region A is defined as follows.

[0016] That is, as best shown in FIG. 3, in one of the cylinder sleeves 3 _1, perpendicular to the plane C including the center line b of all cylinder bores 8, and the center line b of one of the cylinder sleeves 3 ₁ of the cylinder bore 8 The inclined surface displaced by about 30 ° at the cylinder bore center angle α from the vertical plane D including the connecting portion 11 toward the connecting portion 11 is defined as E, and the other cylinder sleeve 3 defined in the same manner as the inclined surface E with the connecting portion 11 interposed therebetween. Assuming that the inclined surface in ₂ is F, a range from one inclined surface E to the other inclined surface F through the joint portion 11 is a valley region A.

As shown in FIG. 6, the cylinder block casting mold 14, bore pins 15 are fitted in the respective cylinder sleeves 3 ₁ to 3 ₄ of the cylinder sleeve assembly 3, and the outer periphery of the cylinder sleeve assembly 3 Is provided with a water jacket molding core 16 having an inner peripheral surface along the outer peripheral surface thereof. Thus, a cavity 17 for molding a cylinder barrel assembly is formed between the cylinder sleeve assembly 3 and the core 16.

In casting the cylinder block 1, when a molten metal of an Al alloy is injected into the cavity 17, the molten metal in the portion 17a where the valley-shaped region A faces tends to solidify more slowly than the molten metal in the other portions 17b. .

Therefore, as shown by the two arrows g, the V-shaped portions 4a of the cylinder barrel assembly 4 opposed to the valley region A are subjected to coagulation and contraction forces acting in opposite directions and in the circumferential direction. However, since each projection 12 bites into the V-shaped portion 4a and opposes the coagulation contraction force, the occurrence of shrinkage in the V-shaped portion 4a is suppressed. In this case, since each projection 12 is directed substantially in the radial direction, it exerts a large opposing force against the coagulation contraction force.

Thus, the cylinder barrel assembly 4
Of the V-shaped portion 4a and the valley region A of the cylinder sleeve assembly 3 can be improved.

The cylinder sleeve assembly 3 is cast using a sand mold 18 shown in FIG. The sand mold 18 is made of resin sand.

The sand mold body 19 of the sand mold 18 is composed of a pair of halves 21 symmetrical with respect to a mating surface 20 including the center line b of each cylinder bore 8 and a pair of halves 21 located at both ends. The arc-shaped inner peripheral surface 22, two sets of opposed arc-shaped inner peripheral surfaces 23 between the two arc-shaped inner peripheral surfaces 22 that are opposed to each other, and adjacent arc-shaped inner peripheral surfaces 22 and It has six trapezoidal fitting grooves 24 that connect between the arcuate inner peripheral surfaces 23 and between the adjacent arcuate inner peripheral surfaces 23.

Each space surrounded by each of the arcuate inner peripheral surfaces 22 and each space between the opposing inferior arcuate inner peripheral surfaces 23 include:
In each case, a cylindrical sand core 25 for forming a cylinder bore is installed. A base end 27a of a sand mold 27 is fitted into each of the fitting grooves 24, and is provided with a mountain-shaped inner surface 26 corresponding to the valley region A of the cylinder sleeve assembly 3 so as to be continuous with the base end 27a. The chevron 27b protrudes from the fitting groove 24.

By cooperating the sand mold body 19, the sand cores 25 and the fitting sand molds 27 in this way, a cavity 28 for a cylinder sleeve assembly is formed in the sand mold 18. Although omitted in the figure, the cylinder sleeve assembly 3 is provided on each of the superior arc-shaped inner peripheral surfaces 22 and each of the sub-arc-shaped inner peripheral surfaces 23.
A plurality of recesses and ridges are formed corresponding to the respective recesses and ridges 13 and 10.

As shown in FIGS. 8 and 9, a plurality of concaves and convexes corresponding to the concaves and convexes 13 and 10 of the cylinder sleeve assembly 3 are formed on the inner surface 26 of each of the sand molds 27. The ridges 29, 30 and a plurality of recesses 31 arranged on each of the ridges 30 and casting the respective shrinkage suppressing projections 12 are formed.

In FIG. 7, the sand mold 18 is reinforced by a backup body 32 made of gravel or the like existing outside the sand mold 18.

If a molten metal having a cast iron composition is poured into the cavity 28 of the sand mold 18, the cylinder sleeve assembly 3 shown in FIGS. 3 to 5 can be cast.

The sand mold 18 is molded by using molding dies shown in FIGS. 10 to 15, that is, first and second molding dies 33 and 34 and core molding dies (not shown).

FIG. 10 shows a half 21 of the sand mold body 19.
Shows a first molding die 33 for producing
Reference numeral 3 denotes an upper die 35 and a lower die 36, and a molding cavity 37 corresponding to the half body 21 is formed by the two dies 35 and 36. The half body 21 is formed by blowing resin sand into the cavity 37 from each of the blowing ports 38 of the upper mold 35.

FIGS. 11 to 15 show a second mold 34 for casting a sand mold 27 having a chevron inner surface 26.

As clearly shown in FIGS. 11 and 13, the second molding die 34 is composed of a fixed lower die (forming die component) 39 and an upper die 40 which is attached to and detached from the lower die 39. Type 3
Positioning means (not shown) is provided between the positions 9 and 40. The upper die 40 includes a pair of side walls 41 facing each other at a predetermined interval, and a pair of end walls 42 attached to both end surfaces of the both side walls 41, respectively. It has an inlet 43 for the resin sand. Further, each end wall 42 has a chevron 45 having a pair of concave arc-shaped slopes 44, and the chevron 45 protrudes below the side walls 41. The lower mold 39 has a substantially V-shaped cross section, and a pair of upper surfaces 47 facing the lower surfaces 46 of the side walls 41 of the upper mold 40, and a valley surface 49 connected to both upper surfaces 47 and having a pair of convex arc-shaped slopes 48. And

When the upper and lower dies 40 and 39 are closed, the lower surfaces 46 of the side walls 41 of the upper die 40 match the upper surfaces 47 of the lower die 39, respectively, and both slopes of the chevron 45 of the upper die 40. 44 coincides with both slopes 48 at both ends in the longitudinal direction of the valley surface 49 of the lower mold 39. Thereby, the inner surface of both side walls 41, the inner surface of both end walls 42 and the valley surface 4 of the lower mold 39 are formed.
4 forms a molding cavity 50 corresponding to the fitting sand mold 27.

As shown in FIG. 14, in the molding cavity 50, the trapezoidal region h on the upper mold 40 side is
4, the base end 27a of the sand mold 27 to be fitted into the mold 4 (FIG.
9 is used for molding, and the valley region j on the side of the lower mold 39 forms a mountain 27b (see FIGS. 8 and 9) of the fitting sand mold 27 protruding from the fitting groove 24. Used for

As shown in FIG. 14, in the lower mold 39, each lower mold component 5 forming each slope 48 of the valley surface 49 is formed.
3, a plurality of recesses and projections 54 and 55 corresponding to the respective recesses and projections 29 and 30 of the insertion sand mold 27, and a projection casting recess 31 of the insertion sand mold 27 opened to each of the recesses 54. A plurality of corresponding through holes 56 are formed.

Each of the through holes 56 is slidably fitted with a pin-shaped convex mold 57 for forming the recess 31. In each lower mold component 53, the base end of each convex mold 57 is connected to each lower mold. Mold part 5
3 and are held together by a holder 58 disposed on the back side of the third. In a state in which each holder 58 abuts against the back surface of each lower mold component 53, the tip of each convex mold 57 projects substantially radially from each through hole 56, and the length of the protrusion is the protrusion casting recess 31.
Equal to the depth of

As clearly shown in FIGS. 11 to 14, each lower mold component 53 has an operating mechanism 59 for projecting each convex 57 from each through hole 56 and immersing it into each through hole 56. It is provided as follows.

Support shafts 60 are projected from both end surfaces of each lower mold component 53 so as to be located on the same axis, and a cam plate 61 is rotatably provided on each support shaft 60. Each cam plate 61
It has an elongated hole 62 in an arc shape, and the holder 58
An operation pin 63 protruding from the end face of the first member is slidably fitted. In each of the lower mold components 53, the two parallel arms 65 of the U-shaped operation handle 64 are connected to the outer peripheral portions of both cam plates 61 so as to extend diagonally upward.

As shown by a solid line in FIG.
4 is on the upper side and the operating pin 63 is located at one end side of the elongated hole 62 near the support shaft 60, the holder 58 abuts on the back surface of the lower mold component 53, and the tip of each convex mold 57 is Through hole 5
6 protrudes. On the other hand, when the operation handle 64 is on the lower side and the operating pin 63 is located on the other end side of the long hole 62 far from the support shaft 60 as shown by the chain line in FIG. The distal end of each convex 57 is immersed in the through-hole 56 away from the rear surface.

FIG. 1 shows the molding of the sand mold 27.
4. As shown by the chain line, the operation handle 64 is positioned on the lower side, and each projection 57 is immersed in each through hole 56. Next, resin sand is put into the cavity 50 from the charging inlet 43 and stiffened to form a sand mold material. After that, as shown in FIG.
15 project from each through-hole 56, thereby forming each convex 57 on the mountain-shaped inner surface 26 of the sand mold material as shown in FIG.
Is pressed in to form a projection casting recess 31.

When a plurality of convex dies 57 are densely formed on the valley surface 49, the concave portions 31 are formed simultaneously with the formation of the sand mold 27 with the tips of the convex dies 57 protruding from the through holes 56. Is performed, the resin sand may not reach the tips of all the convexes 57 and may cause defective products. However, as described above, the tips of the respective convexes 57 are pushed into the chevron inner surface 26 of the sand mold material. When each recess 31 is formed, each recess 31 can be formed reliably and without shape collapse.

To release the fitting sand mold 27, the operation handle 64 is again positioned on the lower side, each convex mold 57 is pulled out from each recess 31, and then the upper mold 40 is removed from the fitting sand mold 27. The fitting sand mold 27 is removed from the lower mold 39. This makes it possible to smoothly release the fitting sand mold 27.

It is also possible to fix each convex mold 57 to each lower mold component 53 and move each lower mold component 53 to separate each convex mold 57 from each recess 31. The present invention also provides a sand mold 18 in which a sand mold body 19 and a set sand mold 27 are integrated.
It is also applied to a molding die for molding.

[0043]

According to the present invention, according to the present invention, in a molding die used for manufacturing a sand mold for casting a cylinder sleeve assembly, each convex mold is formed on the inner surface of the chevron prior to releasing the sand mold having the inner chevron. Since the protrusions are detached from the concave portions for casting, the sand mold can be smoothly released without damaging the concave portions.

[Brief description of the drawings]

FIG. 1 is a fragmentary plan view of a main part of a cylinder block.

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

FIG. 3 is a fragmentary plan view of a cylinder sleeve assembly.

FIG. 4 is a fragmentary side view corresponding to a view taken in the direction of arrow 4 in FIG. 3;

FIG. 5 is an enlarged view of a portion indicated by an arrow 5 in FIG. 3;

FIG. 6 is a cross-sectional plan view showing a main part of a cylinder block casting mold.

FIG. 7 is a plan view of a sand mold for casting a cylinder sleeve assembly.

FIG. 8 is a perspective view of a fitting sand mold.

FIG. 9 is a sectional view taken along line 9-9 of FIG. 8;

FIG. 10 shows a first method for forming a half in a sand mold body.
It is a vertical front view of a molding die.

FIG. 11 is a front view of a second molding die for molding a fitting sand mold.

FIG. 12 is a view taken in the direction of arrow 12 in FIG. 11;

FIG. 13 is a view as viewed in the direction indicated by an arrow 13 in FIG. 11;

FIG. 14 is a sectional view taken along line 14-14 of FIG.

FIG. 15 is an explanatory diagram of a molding step of a fitting sand mold.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylinder block 3 Cylinder sleeve aggregate 3 _{1 to} 3 ₄ Cylinder sleeve 9 Peripheral wall 11 Joining part 12 Shrinkage suppressing projection 18 Sand mold 26 Inner surface 27 Inserting sand mold forming sand mold 31 Protrusion casting recess 39 Lower mold (forming mold configuration) Part) 57 convex

Claims (1)

(57) [Scope of request for utility model registration] 1. A cylinder casting as Guruma be barrel assembly (4), the phase Tonariru both cylindrical peripheral wall of the plurality of cylinder sleeves (3 ₁ to 3 ₄₎ of a multi-cylinder internal combustion engine cylinder block (1) (9) Both peripheral walls (9)
(11) The cylinder sleeve assembly (3) located on both sides of the cylinder block (1) into the valley-shaped region (A) of the outer peripheral surface. A molding die for producing a sand mold (18) for casting a cylinder sleeve assembly (3) provided with a suppression projection (12) so as to protrude substantially radially from each cylindrical peripheral wall (9); And a molding component (39) for molding the chevron inner surface (26) of the sand mold (18) corresponding to the valley region (A), and the molding component (39).
A plurality of projection casting recesses (3
1) and a plurality of convex molds (57) which are released from the concave portions (31) prior to the release of the sand mold (18).
A molding die used for producing a sand mold for casting a cylinder sleeve assembly, characterized by having: