JPH0563260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for casting a plurality of engine cylinder blocks simultaneously.

(Prior art) In general, in a line for casting engine cylinder blocks, the size of the mold and the amount of molten metal poured into the mold differ depending on the number of cylinder blocks to be manufactured. It is customary to be constructed for cylinder blocks of 6-cylinder engines, etc., but even in such lines, by adopting the so-called multi-cavity casting method, for example, 2 to 3
Cylinder blocks for cylinder engines can be cast. This multi-cavity casting method involves arranging a plurality of cavities in parallel in a set of molds and providing a single runner that branches and communicates with these cavities. This is a method of forming multiple castings at the same time by demolding. Therefore, if this method is used to obtain, for example, two cylinder block castings for a two-cylinder engine, the cylinder block for the two-cylinder engine will have approximately half the volume of the cylinder block casting for a four-cylinder engine; When making individual cylinder blocks, the size of the mold and the amount of poured metal are approximately the same as when making one cylinder block for a 4-cylinder engine, so cylinder block castings for a 2-cylinder engine are manufactured on a cylinder block casting line for a 4-cylinder engine. This makes it possible.

By the way, in the casting line, after the mold is disassembled, there is so-called chiseling work or sand removal work to remove the surplus solidified in the runner etc. from the manufacturing department of the casting, or after small correction work such as manual grinding and chiseling. Although the processing is performed sequentially, such post-processing is also performed on a plurality of castings as described above. In that case, these multiple castings are connected by the surplus solidified in the runner, and when the surplus is removed in the chiseling process, they are separated into individual castings.
For example, when manufacturing cylinder block castings for a 2-cylinder engine using a cylinder block casting line for a 4-cylinder engine using two cavities, the process after the chiseling process described above will be lower than when manufacturing cylinder block castings for a 4-cylinder engine. Number of castings is 2
It will be doubled. As a result, in the post-processing process after the chiseling process, the work tact and conveyance tact (processing time for one casting) are halved, and therefore 2
In the case of individual production, it is necessary to increase the equipment capacity and personnel organization in the post-processing process. In particular, in the case of mixed production of one cylinder block casting for a four-cylinder engine, for example, and two cylinder block castings for a two-cylinder engine, for example, the setting is such that two-piece casting operations are possible. The equipment capacity and personnel organization that have been built up are wasted when single-piece work is carried out, resulting in a decline in overall productivity.

(Object of the Invention) The present invention addresses the above-mentioned circumstances regarding the casting of cylinder blocks.
To make it possible to perform post-processing work on a plurality of cylinder block castings in the same tact as for a single-cavity casting, in the case of producing cylinder block castings for a cylinder engine by two-cavity castings.
This eliminates the need to increase equipment capacity and personnel when performing multi-cavity casting work, and also eliminates the need to increase equipment capacity and personnel when performing mixed production of single-cavity castings and multi-cavity castings. The purpose is to prevent wasted organization.

(Structure of the Invention) In order to achieve the above object, the casting method of the present invention is characterized by the following structure.

That is, in a multi-cavity casting method using a mold in which a plurality of cavities are arranged side by side to form a cylinder block casting, in addition to the runners leading to each cavity, the mold has a plurality of communication channels that communicate with each other. By providing a part, a plurality of cylinder block castings are connected to form an integrated product, and then this integrated product is subjected to a prescribed post-treatment, and then, at the end of the process, the connected part of the integrated product is cut. This separates the cylinder block into individual castings. In other words, according to this method, each cylinder block casting is not separated even if the surplus solidified in the runner is removed in the chiseling process after demolding, and these castings are connected as a single piece during the chiseling process. Post-processing such as removing sand and manual grinding is then performed. Therefore, in these post-processing steps, it becomes possible to perform the above-mentioned operations, transportation, etc. in the same tact as when casting a single piece. Each cylinder block casting is separated at the end of the process of this casting line, that is, at the stage when it is transferred to a subsequent machining line or the like.

(Effects of the Invention) As described above, according to the method for casting cylinder block castings in multiple pieces according to the present invention, the cylinder block castings made in multiple pieces can be treated as a single piece in the post-processing process after demolding. Therefore, when manufacturing cylinder block castings using a single-cavity cylinder block casting line, the multi-cavity castings can be processed in the same takt as the single-cavity castings after the mold is disassembled. It becomes possible to do so. This eliminates the need to increase equipment capacity and personnel organization when producing multiple pieces, and also eliminates the waste of equipment capacity and personnel when producing single-piece castings and multi-piece castings in mixed production. This will greatly improve productivity in such casting operations.

(Example) Hereinafter, an example of the casting method of the present invention will be described. This embodiment is for a case where two cylinder blocks are used for a two-cylinder engine.

First, the configuration of the mold device used in this example will be explained. As shown in FIG. 1, this mold device 1 has the following structure.
It is composed of a pair of main molds 2, 2 (only one is shown) and a core assembly assembled between the main molds 2, 2. This core assembly includes a front core 3 forming the front end surface of the cylinder block, two bore cores 4, 4 forming the two cylinder parts of the cylinder block, and a water jacket of the cylinder block. It consists of a jacket core 5 that forms the cylinder block, and a rear core 6 that forms the rear end surface of the cylinder block, and two sets of these are set in the main molds 2, 2 to respectively form the cylinder block castings of the two-cylinder engine. The two forming cavities 7, 7 are arranged in series in parallel. Here, the rear core 6 is also used as two sets of core assemblies, and the two cavities 7, 7 are partitioned by the rear core 6. As shown in FIG. 2, a plurality of notches 6a and communication holes 6b are provided in the peripheral portion of this rear core 6, thereby allowing the two cavities 7, 7 to be connected between their opposing surfaces. They are designed to communicate with each other.

Further, the main molds 2, 2 are provided with a runner 9 which is formed so as to extend downward from a sprue 8 opening at the upper end surface, then bend in the horizontal direction and wrap around below the cavities 7, 7. In addition, a plurality of weirs 10 are provided to connect the lower horizontal part 9a of the runner 9 and the cavities 7, 7, respectively, and the vertical part 9b of the runner 9 and the side part of one of the cavities 7 are provided. A reception weir 11 is installed between them.

Next, a casting method using this mold device 1 will be explained according to the process diagram of FIG. 3.

First, as a first step, a mold device 1 is assembled using the main molds 2, 2 and each of the cores 3 to 6, and two cavities 7, 7 forming the cylinder block of a two-cylinder engine are formed, Next, as a second step, molten metal is injected from the sprue 8 in this mold device 1. This molten metal flows from the horizontal part 9a below the runner 9 through the weirs 10...10 into the two cavities 7, 7, respectively, and when the injection level reaches a certain level, the molten metal flows into the runner 9. It flows into one cavity 7 from the vertical part 9b through the reception weir 11. At this time, the two cavities 7, 7 are communicated with each other through the notch 6a and communication hole 6b provided in the rear core 6 of the core assembly.
The molten metal flows into both cavities 7, 7 while maintaining approximately the same level, so that a casting having approximately the same structure is formed by both cavities 7, 7, and casting defects are reduced. Become.

When the pouring work is completed in this way and the hot water in the cavities 7 and 7 is solidified, the mold device 1 is demolded as shown in FIGS. 4 and 5 as a third step. An integral product 20 is obtained. This integrated product 20 consists of two cylinder block castings 21, 21 solidified in the cavities 7, 7, respectively, and an excess portion 22 solidified in the runners 9 and weirs 10, 11 in the molding device 1. However, two more cylinder block castings 21, 21 are placed in the notch 6a of the rear core 6.
A plurality of connecting portions 23 solidified within the communication hole 6b...
They are connected to each other by 23.

Post-processing is then performed on this product 20, and first, as the first step (fourth step), a chiseling operation is performed to remove the surplus portion 22. At this time, two cylinder block castings 21,
21 are connected only by the surplus portion 22, both castings 21, 21 will be separated, but connecting portions 23...23 are provided between these castings 21, 21 as described above. As a result, the two cylinder block castings 21, 21 are not separated by this chiseling operation, and are connected to each other by the connecting portions 23...23 as shown in FIG. A product 20' is obtained. and,
Regarding this intermediate integrated product 20', further post-processing steps include sand removal work (fifth process), manual grinding work to remove small surplus parts such as burrs (sixth process), and a manual grinding process (sixth process). Chiseling work (seventh step) and black coating work for rust prevention (eighth step) are performed in sequence.

When the post-processing of the intermediate integrated product 20' is completed in this way, the next step is to cut the connecting portions 23...23 connecting the two cylinder block castings 21, 21. As a result, the two cylinder block castings 21, 21 are separated for the first time, resulting in a product 21' as shown in FIG.
This product (cylinder block casting) 21' is then transferred to a machining line.

As described above, according to this casting method, each work in the post-processing process is performed in the state of the intermediate integral product 20' before the two cylinder lock castings 21, 21 are separated, that is, as one casting. For example, this cylinder lock casting 21, 2
1 using a cylinder block casting line for a four-cylinder engine, the work and transportation in each of the above steps can be performed in the same takt as when manufacturing the cylinder block casting for a four-cylinder engine. Therefore, there is no need to increase equipment capacity or personnel organization to perform two-piece work.
Particularly in the case of mixed production of two-cavity castings and one-cavity castings, waste of equipment capacity and personnel due to changes in takt time can be prevented.

In this example, the cutting operation in the ninth step was performed after the black painting operation in the eighth step.
The order of these operations may be reversed, or the cutting operation may be performed as the first step in the machining line.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a mold device used in an embodiment of the casting method of the present invention, and FIG. 2 is a perspective view of a rear core in the mold device. Fig. 3 is a process diagram showing an embodiment of the casting method of the present invention, Fig. 4 is a front view of the product obtained in the demolding process, and Fig. 5 is Fig. 4-
FIG. 6 is a front view of the intermediate integral product obtained in the chiseling process, and FIG. 7 is a perspective view of the cylinder block casting obtained in the cutting process. 1 to 6... Mold (1... Mold device, 2... Main mold,
3 to 6... Core), 6a, 6b... Communication portion (6a
...notch, 6b ... communication hole), 7 ... cavity, 9 ... runner, 20, 20' ... integral part, 21,
21'...Cylinder block casting, 23...Connection part.

Claims (1)

[Claims] 1. A multi-piece casting method for cylinder block castings using a mold in which a plurality of cavities are arranged side by side for forming cylinder block castings, in which the molds are provided with these cavities in addition to the runners leading to each cavity. By providing a plurality of communicating parts, a plurality of cylinder block castings are connected to form an integrated product.This integrated product is then subjected to predetermined post-processing, and then, at the end of the process, the integrated product is A method for casting cylinder block castings in multiple pieces, characterized in that the cylinder block castings are separated into individual castings by cutting the connecting portions.