JP5549101B2 - Cylinder block, its casting mold and its casting method - Google Patents

Description

  The present invention relates to a cylinder block having a water jacket on the outer peripheral side of a cylinder bore along the circumferential direction thereof, a casting mold thereof, and a casting molding method thereof.

  Conventionally, when a cylinder block made of a light alloy such as an aluminum alloy is cast and formed, the cylinder side wall portion between the cylinder bore and the surrounding water jacket becomes thin, so the hot water around the thin portion deteriorates. It tends to cause casting defects.

  For this reason, for example, in the light alloy cylinder block described in the following Patent Document 1, a thick and wide protruding portion that is cut and removed after casting at the end of the cylinder side wall portion that is thin between adjacent cylinder bores. The hot water supply is improved by providing.

Japanese Utility Model Publication 2-48122

  However, in the conventional cylinder block described above, the protruding part for improving the hot water supply is an unnecessary part as a product, so it is necessary to remove it after casting. For this reason, a work process for cutting and removing is set separately. It is necessary to increase the manufacturing cost. In addition, a solidification shrinkage defect may occur on the surface of the product exposed after cutting and removal.

  Therefore, the object of the present invention is to improve the hot water supply without providing a portion which is unnecessary as a product and is removed after casting.

The present invention is a casting mold of a cylinder block including a water jacket forming die for forming a water jacket formed between a cylinder side wall portion and an outer wall portion outside the cylinder side wall portion, and the water jacket includes the cylinder side wall portion. is formed along the circumferential direction, the water jacket mold corresponding to the water jacket, the projects from the cylinder side wall portion in a part of the circumferential direction of the water jacket, the crank case side of the water jacket The casting mold has a plurality of cylinder bore forming parts arranged in series such that a plurality of cylinder bores are arranged in series, and the notch Is the cylinder bore molding portion at the end on one side in the arrangement direction of the plurality of cylinder bore molding portions. Provided only on the opposite side of the cylinder bore forming portion adjacent to Ndaboa molding section, characterized in that the melt supply port is provided in the cylinder bore forming portion of the end portion in the array direction other side of the plurality of cylinder bores formed portion And

According to the present invention, at the time of casting, the molten metal enters the notch portion that forms the rib protruding from the cylinder side wall portion, so that even if the cylinder side wall portion is thin, the hot water circulation is improved and casting defects are suppressed. it can. At this time, since the rib is formed so as to protrude from the cylinder side wall into the water jacket, it is not necessary to remove it after casting, and therefore a portion that is unnecessary as a product and is removed after casting is provided. It is possible to improve the hot water circulation and increase the rigidity of the cylinder side wall by the rib.

It is a top view of the cylinder block which shows the 1st Embodiment of this invention. FIG. 2 is a cross-sectional view taken along line AA including a cylinder bore central axis in a lower bank in FIG. 1. FIG. 2 is a perspective view of a water jacket mold for forming a water jacket in the cylinder block of FIG. 1. It is a top view which shows the water jacket periphery of the cylinder block concerning the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
A cylinder block 1 of a V-type 6-cylinder engine shown in FIG. 1 is made of a light alloy made of an aluminum alloy, and is cast using a casting mold (not shown). Each cylinder bore 3 of the cylinder block 1 is cast with a cast iron sleeve 5 in order to increase the rigidity of the weight-reduced cylinder block 1.

  A water jacket 9 is formed on the outer peripheral side of the cylinder side wall 7 on the aluminum alloy side where the sleeve 5 is cast. The cylinder side wall portion 7 has a continuous portion 11 that is continuous between adjacent ones of three cylinder bores 3 that are arranged in series in one bank of the V-type engine, and includes the continuous portion 11. The above-described water jacket 9 is formed so as to surround the periphery of one cylinder side wall portion 7.

  That is, the water jacket 9 is provided along the circumferential direction of the cylinder side wall portion 7 between the cylinder side wall portion 7 and the outer wall portion 13 outside thereof.

In the first embodiment, ribs 15 that protrude from the cylinder side wall 7 are provided in a part of the circumferential direction of the water jacket 9 in the two banks of the V-type engine. The rib 15 is on the left side of the cylinder bore 3 in out Figure 1 of the three cylinder bores 3 in each bank is provided on the opposite side with respect to the center of the cylinder bore 3 that is adjacent to the left-side cylinder bore 3.

  The rib 15 described above protrudes from the cylinder side wall portion 7 and also protrudes from the outer wall portion 13 toward the water jacket 9. That is, the rib 15 is integrated with the cylinder side wall 7, the outer wall 13, and the bottom surface 9 a side of the water jacket 9.

  FIG. 3 shows a water jacket mold 17 for molding the water jacket 9, and the water jacket mold 17 has a notch 17 a corresponding to the rib 15 described above at the tip. That is, with respect to the bottom surface 9a of the water jacket 9 corresponding to the front end surface 17b of the water jacket mold 17, only the portion corresponding to the notch 17a has a rib 15 protruding upward in FIG. The depth of the part corresponding to the rib 15 is shallower than the other parts.

  Here, in the present embodiment, the flow direction of the molten metal in a casting mold (not shown) is from the right side to the left side including the ribs 15 in FIG. 1, and therefore the ribs 15 are downstream in the flow direction of the molten metal at the time of casting. Will be provided. That is, a melt supply port for supplying a melt to the end of the cylinder bore 3 on the right side in FIG. 1 opposite to the cylinder bore 3 having the rib 15 is provided, and a discharge port for gas generated in the cavity is provided to the rib 15. The cylinder bore 3 is provided at the end on the left side in FIG.

  In such a cylinder block 1, even when the cylinder side wall portion 7 is thin, the molten metal enters the portion where the rib 15 continuous to the cylinder side wall portion 7 and the outer wall portion 13 is formed during casting. It is possible to improve and suppress casting defects, and to manufacture a high-quality cylinder block 1. At this time, the rib 15 is continuous so as to protrude from the cylinder side wall portion 7 into the water jacket 9, so it is not necessary to remove it by cutting after casting or the like, and therefore it is necessary to set a work process to be removed separately. Therefore, it is possible to suppress an increase in manufacturing cost.

  Further, in the present embodiment, the rib 15 is provided on the downstream side in the flow direction of the molten metal at the time of casting, so that the gas generated in the cavity can be efficiently discharged to the outside from the portion where the rib 15 is formed, A higher quality cylinder block 1 can be manufactured.

  Further, the rib 15 can be expected to improve the rigidity of the thin cylinder side wall 7. Further, since the ribs 15 are located on the bottom surface 9a side of the water jacket 9, the cooling water in the water jacket 9 becomes a high heat generating portion opposite to the bottom surface 9a corresponding to the crankcase 19 side, which is not shown in the cylinder head side. Can contribute to improving the cooling performance of the engine.

[Second Embodiment]
In the first embodiment, one rib 15 is provided corresponding to each cylinder bore 3 located on the left side in FIG. 1 in the two banks of the V-type engine, but the second embodiment shown in FIG. In the embodiment, a plurality of (here, three) ribs are provided along the circumferential direction of each cylinder bore 3. That is, ribs 15A and 15B adjacent to the rib 15 are further provided on the rib 15 located at the same position as in the first embodiment.

  Each of these ribs 15A and 15B is located on the opposite side of the center of the cylinder bore 3 located on the left side in FIG. It is located downstream of the molten metal flow direction.

  As a result, in the second embodiment, the temperature of the molten metal at the time of casting can be further improved, and the effect of releasing the gas generated in the cavity to the outside is enhanced, thereby producing a higher quality cylinder block 1. In addition, the rigidity of the cylinder side wall 7 and the engine cooling performance can be improved.

  In each of the above-described embodiments, the ribs 15 are provided corresponding to the cylinder bores 3 on the left side in FIG. 1 in the two banks of the V-type engine, but the ribs are provided corresponding to the other cylinder bores 3. Or by appropriately changing the height and width of the ribs, it can be optimized for hot water and gas discharge.

  In each of the above-described embodiments, the V-type engine has been described as an example. However, an in-line engine may be used, and instead of the cast iron sleeve 5 cast into the cylinder side wall 7, An iron-based metal material may be sprayed on the inner surface of the cylinder side wall portion 7.

DESCRIPTION OF SYMBOLS 1 Cylinder block 7 Cylinder side wall part 9 Water jacket 9a Bottom surface of a water jacket 13 Outer wall part of a cylinder block 15 Rib 17 Water jacket molding die 17a Notch part of a water jacket molding die 19 Crank case

Claims (3)

A casting mold for a cylinder block including a water jacket mold for forming a water jacket formed between a cylinder side wall and an outer wall on the outside thereof, wherein the water jacket is a circumferential direction of the cylinder side wall. is formed along the water jacket mold corresponding to the water jacket, the projects from the cylinder side wall portion in a part of the circumferential direction of the water jacket, bottom corresponding to the crank case side of the water jacket includes a notch for forming the ribs to be integrated in,
In the casting mold, a plurality of cylinder bore forming portions are arranged in series such that a plurality of cylinder bores are arranged in series,
The notch portion is provided only on the opposite side of the cylinder bore molding portion adjacent to the cylinder bore molding portion of the cylinder bore molding portion at one end in the arrangement direction of the plurality of cylinder bore molding portions,
A cast molding die for a cylinder block , wherein a molten metal supply port is provided on the cylinder bore molding part side of the other end in the arrangement direction of the plurality of cylinder bore molding parts . A cylinder block casting method in which a water jacket formed between a cylinder side wall portion and an outer wall portion outside thereof is formed by a water jacket mold, wherein the water jacket is arranged in a circumferential direction of the cylinder side wall portion. The cylinder side wall is formed in a part of the water jacket in the circumferential direction by inserting molten metal into a notch provided in a part of the water jacket molding die corresponding to the water jacket. protruding from parts, to form a rib integrated into the bottom face corresponding to the crank case side of the water jacket,
The rib is provided only on the opposite side of the cylinder bore at one end in the arrangement direction of the plurality of cylinder bores with respect to the cylinder bore adjacent to the cylinder bore. A cast molding method for a cylinder block, characterized in that a molten metal is supplied from a molten metal supply port provided in the cylinder, and the supplied molten metal flows toward a side where the rib is formed . A cylinder block cast by the method of casting a cylinder block according to claim 2 .

Images