JPH11320030A - Jacket core for forming cylinder block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically assemble a chaplet for reinforcing a jacket core in a siemese type cylinder block and to improve the fitting strength of the chaplet. SOLUTION: Three or more clinching pieces 21 (21a-21c) are formed at both end parts of the band plate-like chaplet 20, and each of the clinching pieces 21 is alternately turned mutually in the reversed direction, and a gap (m) is formed between adjacent clinching pieces 21, and both end parts of the chaplet 20 are embedded into gap facing wall parts 6 of the jacket core 5. Each of three or more clinching pieces 21 makes the posture of the chaplet 20 stabilized at the time of holding by interposing the chaplet 20 from both ends thereof, and the gap (m) serves to keep the fluidity of the molding sand at the time of forming the jacket core to prevent the clogging of the sand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jacket core used for casting a Siamese type cylinder block, and more particularly to a shape of a reinforcing core for the jacket core.

[0002]

2. Description of the Related Art FIG. 5 shows a Siamese type cylinder block in which a cylinder wall between adjacent cylinder bores is integrated to reduce the size and weight. The cylinder block 1 shown in FIG. 2 is surrounded by a water jacket 3. The cylinder wall 4 between the adjacent cylinder bores 2 is integrated, and the bore pitch P is set small, whereby the size and weight of the cylinder block 1 can be reduced.

A jacket core 5 shown in FIG. 6 is for casting the above-mentioned cylinder block 1 and has a shape of a space between a plurality of cylinder bores 2 arranged in a row and a water jacket 3. In the jacket core 5, a portion forming the cylinder wall 4 between the adjacent cylinder bores 2 of the cylinder block 1 is a gap portion G, and the core reinforcing keren 7 is bridged over the gap portion G. Has been done. Keren 7 is a strip-shaped metal plate, and has folded pieces 8 and 9 at the upper and lower ends of both ends as shown in FIG. The upper and lower folded pieces 8 and 9 are bent at predetermined angles in opposite directions in the plate thickness direction, and both ends of the Keren 7 including the folded pieces 8 and 9 are connected to a jacket core as shown in FIG. 5 is buried and fixed in the gap facing wall portion 6 facing on both sides of the gap portion G of FIG.

[0004] The jacket core 5 having the helium 7 is formed by inserting molding sand into the dies while inserting and holding the helens 7 in a not-shown die.
If the jacket core 5 is not provided with the keel 7, the jacket core 5 is easily deformed inward and outward due to the space of the gap portion G, and is broken or deformed at the time of casting the cylinder block to reduce the dimensional quality of the cylinder block. May worsen.
Therefore, both ends of the helmet 7 are buried in the gap facing wall portions 6 on both sides of the gap portion G having a low mechanical strength of the jacket core 5, and the kelen 7 is bridged over the gap portion G. Since the Keren 7 has a pair of upper and lower folded pieces 8 and 9 at both ends folded in opposite directions, the Keren 7 does not bite into the gap facing wall portion 6 of the jacket core 5 and does not come off, and the gap facing wall portion 6 does not move inside and outside. Reinforces without deformation.

[0005]

At the time of molding the jacket core 5 as described above, the kelenium 7 is placed in a mold (not shown).
Is set with the hands of the operator, but the workability of this manual setting is poor, and the mold temperature is high (about 300 ° C.), which imposes a heavy burden on the operator. Therefore, automatic insertion of the keren 7 into the mold by a robot arm or the like has been studied, but at present it is difficult to automatically insert the keren 7 for the following reasons.

[0009] As a method of automatically inserting the helmet 7 into the mold, for example, as shown in FIG. 9 (A), the flat central portion of the helmet 7 is held by a chuck claw 10 of a robot arm, and the helmet 7 is inserted into the mold. To be inserted into the file. But,
In this case, the chuck claw 10 interferes with the cylinder bore forming portion of the mold (not shown), and it is difficult to automatically insert the keel 7 into the mold.

Further, as shown in FIG.
It is also conceivable that two rod-shaped chuck rods 11 are fitted between the folded pieces 8 and 9 at both ends, and the two chuck rods 11 sandwich the keren 7 from both ends and insert it into the mold. .
In this case, the chuck rod 11 is present in the jacket core forming portion and does not interfere with the mold, and the kelen 7 can be automatically inserted into the mold. However, when the chuck bar 11 is held between the pair of upper and lower folded pieces 8 and 9 at both ends of the Keren 7, the Keren 7 tilts back and forth around the middle position between the upper and lower folded pieces 8 and 9. Then, the keren 7 is attached to the chuck rod 1
Therefore, it is difficult to hold the keren 7 in a stable position in a mold in a stable position.

[0008] In addition, the casting sand is set in the mold by setting the wrench 7 therein. At this time, the folded pieces 8 and 9 at both ends of the wrench 7 obstruct the flow of the casting sand. As a result, sand clogging is likely to occur at both ends of the Keren 7, and the occurrence of the sand clogging may cause unstable connection strength between the jacket core 5 and the Keren 7.

SUMMARY OF THE INVENTION An object of the present invention is to provide a jacket core which can easily and automatically insert keren into a mold for molding a jacket core and in which kelen is always connected and fixed with stable strength.

[0010]

The technical means to achieve the above object of the present invention is to provide a jacket core for forming a Siamese type cylinder block in which a cylinder wall between adjacent cylinder bores is integrated, between adjacent cylinder bores. In the gap portion corresponding to the portion forming the cylinder wall, both gap facing wall portions are wrapped around the gap portion facing both side portions of the gap portion with both ends buried and bridged. In the reinforced jacket core, both ends embedded in the jacket core of keren are divided into three or more folded pieces in a comb shape, and each folded piece is alternately folded in the opposite thickness direction. It is characterized by being tuned.

Further, the present invention is characterized in that a gap is formed between adjacent folded pieces of each of the folded pieces at both ends of the Keren to allow molding sand to flow during core molding.

Here, the both ends of the keren are divided into three or more folded pieces in the form of a comb, and each folded piece is alternately bent in the opposite thickness direction, so that at least three continuous folded parts vertically. The upper and lower two folded pieces and the middle one folded piece are folded in opposite directions, and the chuck bar is stabilized when the chuck bar is fitted between the upper and lower two folded pieces and the middle folded piece, With this stability, Keren can be held in a stable posture from both ends by a pair of chuck rods, and it becomes easy to automatically insert Keren into the jacket core forming die. In addition, by forming a gap between the folded pieces at both ends of the keel to positively flow the foundry sand, when inserting the keren into the mold and molding the foundry sand to mold the jacket core In addition, the gap between the folded pieces prevents the sand from being clogged with the casting sand, and the connection strength between the keren and the jacket core is greatly stabilized.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS. Note that the same reference numerals are given to the same parts throughout all the drawings including FIGS. 5 to 9 to avoid duplication of description.

FIG. 1 shows a specific example of the Keren 20 which is a feature of the present invention. The Keren 20 is a strip-shaped metal plate, and its both ends are indicated by chain lines in FIGS. 2 (A) and 2 (B). It is embedded in the gap facing wall portion 6 of the jacket core 5 as shown. Keren 2
The both ends of 0 are vertically divided into a plurality of three or more, for example, three, and three folded pieces 21 are formed at both ends.
The folding pieces 21 are an upper folding piece 21a, a middle folding piece 21b, and a lower folding piece 21c. The upper and lower folding pieces 21a and 21c are bent in the same thickness direction, and the middle folding piece 21b is folded. It is bent in the opposite thickness direction.

The upper and middle folded pieces 21a, 21a
The gap m is positively formed between the folded parts 21b and 21c between the folded pieces 21b and 21c of the middle and lower parts. The gap m has a size that does not hinder the flowability of the molding sand when the jacket core 5 is molded with the molding sand. Keren 20 having such a gap m and three or more folded pieces 21 at both ends is incorporated into jacket core 5 in the same manner as in the related art to reinforce jacket core 5.

When positioning and holding the helium 20 in a mold (not shown) for molding the jacket core 5, the helium 20 may be held between a pair of chuck rods 11 as shown in FIG. 3, for example. The chuck rod 11 is installed at the tip of a robot arm (not shown) so as to be openable and closable.
Is inserted between the folded pieces 21a, 21c and the folded piece 21b, which are bent in opposite directions at both ends of the Keren 20, and the Keren 20 is held. If inserted into the mold, the automatic insertion of the Keren 20 into the mold is easy and
You will be able to do it accurately.

That is, As shown in FIGS. 3 and 4, when a pair of chuck rods 11 are fitted into both ends of the helmet 20, the chuck rod 11 is sandwiched between the upper and lower folded pieces 21 a and 21 c and the middle folded piece 21 b, and Is held in a stable posture. Therefore, when the helmet 20 held by the pair of chuck rods 11 is automatically inserted into the mold,
Is held at a fixed position in the mold in a stable posture, and the molding sand is injected into the mold.

As shown by the chain lines in FIG. 4, both ends of the Keren 20 are embedded in the gap-facing wall 6 of the jacket core 5. The foundry sand when burying both ends of the crepe 20 in the gap-facing wall portion 6 flows through the gaps m at two positions above and below the both ends of the crepe 20, thereby forming the upper and lower folded pieces 21.
Sand clogging is reduced. By this improvement of the core sand clogging, the connection strength between the jacket core 5 and the keel 20 is greatly stabilized. In addition, the three folded pieces 21 at both ends of the Keren 20 are alternately bent in opposite directions to form the gap facing wall portion 6.
, The pull-out resistance of the Keren 20 from the gap-facing wall 6 increases. With this increase in pullout strength,
By the above-mentioned improvement of the core sand clogging, the jacket core 5 is firmly and reliably reinforced by the keel 20.

Each of the folded pieces 21 at both ends of the Keren 20
The number and shape and size of the gap m between the adjacent folded pieces 21 are not limited to the illustrated example.

[0020]

According to the present invention, three or more folded pieces are provided at both ends of the keel, and each folded piece is alternately bent in the opposite direction. Therefore, it is possible to easily automate the work of holding the keren with the chuck and setting the same in the jacket core forming die, thereby improving the productivity of the jacket core.

In addition, by forming a gap through which molding sand flows between the three or more folded pieces at both ends of the keren, the flowability of the molding sand at both ends of the keren during molding of the jacket core is improved. Sand clogging can be reduced, and a high-quality jacket core that is firmly and stably reinforced with kerosene and has a stable shape can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a specific example of keren used for a jacket core according to the present invention.

2 (A) is a plan view of the Keren in FIG. 1, and FIG. 2 (B) is a front view of the Keren.

FIG. 3 is a perspective view of the helmet shown in FIG. 1 when chucked.

FIG. 4 is a plan view of the Keren of FIG. 3;

FIG. 5 is a plan view of a cylinder block.

FIG. 6 is a plan view including a partially omitted portion of a conventional jacket core.

FIG. 7 is a cross-sectional view of a portion of FIG.

FIG. 8 is a perspective view of keren used for a conventional jacket core.

FIG. 9A is a plan view when the keel of FIG. 8 is chucked at the center, and FIG. 9B is a plan view when the keel is chucked from both ends.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder bore 4 Cylinder wall 5 Jacket core 6 Gap facing wall G Gap portion 20 Keren 21 Folding pieces 21a to 21c Folding piece m Gap

Claims (2)

[Claims] 1. A gap portion corresponding to a portion forming a cylinder wall between adjacent cylinder bores of a jacket core forming a Siamese type cylinder block in which cylinder walls between adjacent cylinder bores are integrated. In a jacket core in which both ends are buried and bridged with both ends buried in both gap facing walls facing both sides of the part, the gap core facing the wall, A cylindrical core for forming a cylinder block, characterized in that both end portions embedded in the armature are divided into three or more folded pieces in a comb shape, and the folded pieces are alternately bent in opposite plate thickness directions. . 2. A cylinder block forming jacket according to claim 1, wherein a gap for flowing molding sand at the time of core forming is formed between adjacent turned pieces of each of the turned pieces at both ends of the Keren. Child.