JPS6317554Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of a bonded shell core for casting.

(Prior art) In recent years, automobile engines have replaced in-line engines with cylinders arranged in series, and in order to make engines lighter and more compact,
V-type engines arranged in rows are being put into practical use.

For example, in a 6-cylinder V-type engine, a cylinder block (casting product) 1 as shown in FIG.
The core for casting this is much more complex than that for an in-line engine, and high precision is also required for the assembly of the core.

By the way, referring to FIG. 6, the core for casting the cylinder block 1 of the V-type engine as described above includes a bore core 31, left and right jacket cores 32, 33, and a chamber core 34. , the left and right pillow cores 35, 36, the front and rear side cores 37, 38, and the pump core 39. The bore core 31 is engaged with the lower mold, and then the left and right jacket cores The inserts 32 and 33 are fitted obliquely, and the chamber core 34, left and right pillow cores 35,
36 is engaged and placed, and the front side core 37 and
Rear side core 3 with pump core 39 combined in advance
8 and are assembled by engaging with each other.

For example, the left and right jacket cores 32, 33
The left and right pillow cores 35, 36 are arranged between the upper left slope 1e and the upper right slope of the cylinder block 1, as shown in FIG. Concave portions 4, . . . , 4 formed in the left and right pillow cores 35, 36 forming the slope 1g, etc., and convex portions 7, . 7, and both cores 35 and 3
It is necessary to adopt a bonding structure in which 2, 36, and 33 are bonded.

Conventionally, as a joint structure of such a core, a press-fit joint is used in which a convex part of a second core (left and right jacket cores 32, 33) is press-fitted into a concave part of a first core (left and right pillow cores 35, 36). Although it is known (Jikko 49-
24576) and the core of cylinder block 1, where strength is required during assembly and casting, it is difficult to use press-fit connection because there is a risk of positional displacement or removal.

Therefore, as shown in Figure 2, the left and right pillow cores 35, 3
Apply adhesive 8 to the concave portion 4 of 6 and the convex portion 7 of the left and right jacket cores 32, 33, and attach both cores 35 and 3.
It is conceivable to bond the cores 35, 32, and 33 with adhesive, but the buoyancy of the adhesive 8 tends to cause poor assembly accuracy, and in order to prevent this buoyancy, the cores 35 and 32, Since it is necessary to clamp 33, both cores 35 and 32,3
It takes time to assemble parts 6 and 33 and the workability is poor.

Further, if the adhesive 8 protrudes as shown by 8' in FIG. 2, the casting will be defective in that part, and there is a risk that the cylinder block (cast product) 1 will be defective.

(Purpose of the invention) The present invention was made in order to solve the problems of the conventional core joining structure described above, and aims to ensure and speed up the core joining work, and to
The basic purpose is to eliminate the need for clamping jigs and the like.

(Structure of the invention) Therefore, in the present invention, while the convex part of the second core is fitted into the concave part of the first core and integrated, the adhesive is injected from the injection hole of the concave part of the first core. By injecting the adhesive and allowing the adhesive to permeate across the porous concave portions and convex portions, the two cores are bonded by permeation and adhesive.

(Effects of the invention) According to the invention, the first core and the second core are bonded together by penetration adhesive using the adhesive injected from the injection hole, so the joining operation can be performed simply by injecting the adhesive. It will be completed reliably and work efficiency will be significantly improved.

Furthermore, since no adhesive is used on the casting surface side, casting defects due to adhesive extrusion do not occur, the quality of the cast product is stabilized, and the yield rate is improved.

(Example) As shown in FIGS. 3 and 4, a cylinder block 11 of a six-cylinder V-type engine has a front surface 11a and a rear surface 11b having approximately regular pentagonal shapes at the front and rear.
(The rear surface 11b side is specifically shown in FIG. 4.) On the other hand, the front surface 11a
A top chamber 11c is formed at the top between the rear surface 11b and a bottom chamber 11d into which a crankshaft etc. is installed.
The upper left slope 11e and the lower left slope 11f in which the cylinder bores 12,..., 12 are opened, and the front surface 1
An upper right slope 11g and a lower right slope 11h are formed with three cylinder bores 12, . . . , 12 opening at a predetermined pitch from the side 1a.

As shown in FIG. 5, the core 40 for casting the cylinder block 11 of the V-type engine as described above has two rows of left and right bore forming portions 30 that are substantially equally inclined left and right with respect to a vertical line,... , 30 and forming the bottom chamber 11d etc.
, the peripheral wall of each bore 12 and the water jacket 2
Left and right jacket cores 3 forming 5,...etc.
2, 33, a chamber core 34 forming the top chamber 11c, etc., and left and right pillow cores 35, 36 forming the upper left slope 11e, the upper right slope 11g, etc.
and front and rear side cores 37, 3 forming the front surface 11a, rear surface 11b, etc.
8 and a pump core 39 forming a cooling water passage.

Each of these cores 31 to 39 is formed by hardening resin-coated core sand, and is porous as a whole.

Then, the bore core 31 is engaged with a lower mold (not shown), then the left and right jacket cores 32 and 33 are fitted at an angle, and the chamber core 34 and the left and right pillow cores 35 and 36 are engaged and placed. Front side core 3
7 and the rear side core 38 to which the pump core 39 has been previously combined are engaged to assemble.

By engaging and integrating left and right main molds (not shown) with the assembled core 40, a mold for the cylinder block 11 for a V-type engine is completed.

Next, the connection structure of the jacket cores 32, 33 to the left and right pillow cores 35, 36 will be explained.

As shown in Figure 6a, the left and right jacket cores 3
Appropriate tapered convex portions 32b, ..., 33b, ... are formed on the upper surfaces 32a, 33a of 2, 33, while the left and right upper slopes 11e, 1 of the left and right pillow cores 35, 36 are formed.
Forming tapered recesses 35b, . . . , 36b, . . . into which the convex portions 32b, . . . , 33b, .
The outer surfaces 35c, 3 are attached to the recesses 35b,..., 36b,...
Inlet ports 35d, . . . , 36d, .

Then, the convex portions 32b, 33b of the left and right jacket cores 32, 33 are inserted into the concave portions 35 of the left and right pillow cores 35, 36.
Then, as shown in FIG. 6b in this fitted and integrated state, fluidity is applied to the injection holes 35d and 36d from the outer surfaces 35c and 36c of the left and right pillow cores 35 and 36. The adhesive 41 is injected.

The adhesive 41 used is one whose main component is a resin that coats the core sand.

Therefore, the adhesive 41 injected from the injection ports 35d and 36d is applied to the porous left and right pillow cores 35 and 3, respectively.
6 recesses 35b, 36b and left and right jacket cores 3
It penetrates over a relatively wide range spanning the convex portions 32b and 33b of 2 and 33.

As the adhesive 41 penetrates, the convex portions 32b, 33b of the left and right jacket cores 32, 33 become irremovably bonded to the concave portions 35b, 36b of the left and right pillow cores 35, 36. be.

In the above embodiment, the connection structure between the left and right pillow cores 35, 36 and the left and right jacket cores 32, 33 for casting the cylinder block 11 of a V-type engine was taken as an example, but the structure is not limited to this. It goes without saying that the present invention can also be applied to other bonding structures for cast products.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a cylinder block of a typical V-type engine, Fig. 2 is a sectional view for explaining the coupling structure between a pillow core and a jacket core according to the prior art, and Fig. 3 is a diagram according to the present invention. 4 is a rear side plan view of a cylinder block of a V-type engine cast using a core, FIG. 4 is a rear front view of FIG. 3, FIG. 5 is an exploded perspective view of the core according to the present invention, and FIG. Figure a is a cutaway perspective view showing a state in which a jacket core is fitted into a pillow core according to the present invention, and Figure 6b is a sectional view showing a joined state in which adhesive is injected from the state in Figure 6a. 11... Cylinder block, 32, 33... Jacket core, 32b, 33b... Convex portion, 35,
36...Pillow core, 35b, 36b...Recess, 35
d, 36d... Injection hole, 40... Core, 41...
glue.

Claims (1)

[Claims for Utility Model Registration] A convex portion formed on a second core is fitted into a concave portion formed on a first core to couple the two cores, at least one of the two cores. The concave portion and the convex portion are formed of porous core sand, and the concave portion of the first core is provided with an injection hole that penetrates to the outside,
With the convex part of the second core fitted into the concave part of the first core and integrated, an adhesive is injected from the injection hole, and the adhesive connects the porous concave part and the convex part. A bonded shell core characterized in that both cores are bonded by penetrating across the cores.