JPH03230858A - Method for controlling filling-up of molten metal in mold for forming cylinder block raw material for multi-cylinder internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the development of blow hole by reducing cross sectional area in a runner step by step in a mold for forming a cylinder block for multi- cylinder internal combustion engine and constituting the mold so as to uniformize rising of molten metal surface flowing into cavity through a gate from a runner. CONSTITUTION:In the molten metal pouring control into the mold for forming the cylinder block in the multi-cylinder, the mold M with bottom face 17b of the runner formed to rising step state and top face 17c formed to horizontal and reducing the cross sectional area in the runner step by step, is used. By this setting of the cross section, the mold is constituted so that the raising surface of molten metal in the cavity C comes to uniformize the whole surface through each gate 19 from the runner 17. By this method, involution of gas into the molten metal can be prevented and therefore, the development of blow hole in the cylinder block is prevented and the quality can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION A0 Object of the Invention (1) Industrial Application Field The present invention relates to a method for controlling the filling of molten metal in a mold used for casting a cylinder block material for a multi-cylinder internal combustion engine.

(2) Prior Art Conventionally, as this type of mold, one in which a pair of runners are disposed approximately along the lower edges of both sides in the lateral direction of a cylinder block molding cavity is known. In this case, the top and bottom surfaces of both runners are formed substantially horizontally from their upstream ends on the hot water supply section side to their downstream ends.

(3) Problems to be Solved by the Invention However, if the cross-sectional area of each runner is made uniform over almost the entire length as described above, the filling timing of molten metal will be different between the hot water supply section side of the cavity and the opposite side. In other words, since the rise of the hot water level in the cavity becomes uneven in each part,
There is a problem in that the molten metal causes turbulence within the cavity and entrains gases such as air, creating cavities in the material.

The present invention has been proposed in view of the above, and provides a method in which the rise in the level of the molten metal within the cavity is approximately uniform over the entire area, thereby preventing turbulence of the molten metal. The purpose is to

B0 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a cavity corresponding to the shape of a cylinder block material for a multi-cylinder internal combustion engine;
A pair of runners extending substantially along the lower edges of both lateral sides of the cavity, a plurality of weirs communicating between each runner and the cavity, and a hot water supply section communicating with an upstream end of each runner;
In a method of controlling molten metal filling in a mold for forming a cylinder block material for a multi-cylinder internal combustion engine, the bottom surface of each runner is formed in the shape of an ascending staircase from upstream to downstream, and the top surface of each runner is roughly shaped. The mold is formed horizontally and the cross-sectional area of each runner is gradually reduced, and by setting the cross-sectional area of the runner, the molten metal flows into the cavity from the runner through each layer. It is characterized in that the rise in the hot water level within the chamber is made to be approximately uniform over the entire area.

(2) Function The upwardly stepped bottom surface of the runner can gradually increase the flow rate of the molten metal in the runner as it goes downstream, so even if it passes through a weir on the downstream side far away from the hot water supply part, the necessary amount of molten metal can flow into the cavity. will be introduced without delay.

Moreover, even if the volume distribution in the longitudinal direction of the cavity is not the same in each part due to the complex shape structure of a cylinder block for a multi-cylinder internal combustion engine, by setting the cross-sectional area of the runner,
Since the level of the molten metal flowing into the cavity from the runner through each layer can be raised almost uniformly over the entire area, gas entrainment into the molten metal can be effectively prevented. can.

(3) Embodiment Figures 1 to 3 show a Siamese type cylinder block S, which has an aluminum alloy cylinder block body 2.
and a cast iron sleeve 3 cast into the main body 2. The cylinder block main body 2 includes a Siamese cylinder barrel 1 formed by connecting a plurality of cylinder barrels 11 to 14 (in the illustrated example, four cylinder barrels) arranged in series, an outer wall 4 surrounding the Siamese cylinder barrel 1, and an outer wall 4. The sleeve 63 is cast into each cylinder barrel 11-14, and each sleeve 3 forms a cylinder bore 3a.

A water jacket 6 is provided between the Siamese cylinder barrel 1 and the outer wall 4 so that the outer circumference of the Siamese cylinder barrel 1 can be seen.
is formed. At the end of the water jacket 6 on the cylinder head side, the Siamese cylinder barrel 1 and the outer wall 4 are partially connected by a plurality of reinforcing deck parts 8, and the adjacent reinforcing deck parts 8 communicate with each other to the cylinder head side. Functions as a loa. As a result, the cylinder block S is configured into a closed deck type.

Figures 5 to 9 show the cylinder block material S shown in Figure 4.
The casting device is equipped with a mold M as a mold according to the present invention, and the mold M has an upper mold 9 that can be raised and lowered,
The fifth. In FIG. 6, the first and second side molds 10 are divided into left and right halves. ．． 10□ and in FIG. 7, and a lower mold 11 on which the side molds 10I to 104 are slidably placed.

On the lower surface of the upper mold 9, each side mold 10+ to 10. A mold clamping recess 12 is formed to define a first cavity sliding member for molding the Siamese cylinder barrel 1 and outer wall 4 in cooperation with the upper half, and a mold clamping member that fits into the recess 12 is formed. A protrusion 13 is provided to protrude from the upper surface of each side mold 10, to 104.

7th. As shown in FIG. 8, the lower mold 11 is provided with a hot water supply section A, which includes a sump section 14 that receives molten metal made of aluminum alloy from a melting furnace (not shown), and a sump section 14 that receives molten metal from an aluminum alloy from a melting furnace (not shown). It consists of a hot water supply cylinder 15 communicating with the hot water supply cylinder 14, and a plunger 16 slidingly engaged with the hot water supply cylinder 15. Further, a pair of runners 17 are formed in the lower mold 11, which branch into two from the trough portion 14 and extend in the longitudinal direction (ie, the crank axis direction) of the first cavity C3. Furthermore, the lower mold 11 has a molding block 18 projecting upwardly between the two runners 17, and the molding block 18 has a molding block 18 on each side mold 10. ~10
A second cavity C2 for forming the crankcase 5 is defined in cooperation with the lower half of the crankcase 4. The upper end of the second cavity C2 directly communicates with the first cavity C1, and the lower edges of both sides of the second cavity C2 in the lateral direction (vertical direction in FIG. 8) are connected to the two runners extending substantially along them. 17
are communicated with each other via a plurality of weirs 19. These first and second cavities C, C2 constitute a cylinder block molding cavity C.

A molding block consists of four tall semi-cylindrical first molding parts 1B formed at predetermined intervals, 181 adjacent first molding parts, and the outside of the outermost double cylinder 1 molding part 1B+. and a convex-shaped second molded part 182 located at each of the first molded parts 18. is used to form the rotation space 20 for the crank pin and crank arm (see Figures 2 and 3), and the second molded part 18□ is used to form the bearing holder 21 of the crank journal (see Figures 2 and 3). used to form Each layer 19 is provided corresponding to each second molded part 18□.

From the upstream end of each runner 17 communicating with the water reservoir 14 to the runner light 17a, which is the downstream end, the bottom surface 17b of both runners 17
is shaped like several ascending steps, and both hot water paths 17
The top surface 17c of
The cross-sectional area of 7 gradually decreases from the hot water supply section A toward the runner light 17a. Each rising portion 1 connected to each step portion 17d
7e is arranged corresponding to each layer 19, and the molten metal is distributed to each layer 19.
It is formed diagonally so that it can be efficiently guided to 9.

By forming the bottom surface 17b of the runner 17 in the ascending step shape as described above, the flow velocity of the molten metal in the runner 17 can be gradually increased as it goes downstream (for example, in the upstream area where the cross-sectional area is relatively large). In the side runner 17, a large amount of molten metal is passed through the weir 19 at a slow speed and filled into the second cavity C2, and in the downstream runner 17, which has a relatively small cross-sectional area, a small amount of molten metal is passed through the weir 19 at a high speed and filled into the second cavity C2. (can be filled into cavity C2). As a result, the necessary amount of molten metal can be introduced into the cavity C without delay even through the weir 19 on the downstream side far away from the hot water supply section A.

Moreover, in response to the complicated shape structure of the cylinder block material Sm for a multi-cylinder internal combustion engine, even if the volume distribution in the longitudinal direction of the cavity C (especially the second cavity CZ) is not the same in each part, the runner 17 By appropriately setting the cross-sectional area of the runner 17 and the cross-sectional area of both the runner 17 and the weir 19, the molten metal surface in the cavity C2 of the molten metal flowing from the runner 17 through each layer 19 into the second cavity C2 can be controlled over the entire area. It can be raised almost uniformly over the area. That is, to a part of the second cavity C2 with a particularly large volume, the molten metal is supplied relatively quickly from the weir 19 corresponding to that part, and to a part of the second cavity C2 with a particularly small volume, a weir 19 corresponding to that part is supplied. The inflow amount of the molten metal is controlled so that the molten metal is filled relatively slowly from the molten metal into the cavity C2.
Since the molten metal level within the cylinder block can be raised substantially uniformly over the entire area, entrainment of gas into the molten metal can be effectively prevented, and the generation of cavities in the cylinder block material Sm can be avoided. Further, since the molten metal filling operation is performed efficiently as a whole, casting efficiency can be improved.

Fifth. As shown in FIG. 6, a positioning protrusion 22 that fits into the inner peripheral surface of the cast iron sleeve 3 is provided on the top surface of each first molded part 18°, and a recess 23 is provided at the center of the positioning protrusion 22. is formed. Also, two first molded parts 18 located on both sides. , the first molded portion 18 . Through-holes 24 are formed through the through-holes 24, and a pair of temporary installation pins 25 are slid into the through-holes 24, respectively.
These temporary installation pins 25 are used for temporary installation of a sand core for a water jacket, which will be described later. The lower ends of both plate installation pins 25 are connected to a mounting plate 26 disposed below the molded block 18.
Fixed. The mounting plate 26 has two support rods 2.
7 is inserted, and a coil spring 28 is compressed between the lower part of each support rod 27 and the lower surface of the mounting plate 26. When the mold is opened, the mounting plate 26 receives the elastic force of each coil spring 28 and rises until it comes into contact with the stopper 27a at the tip of each support rod 27, so that the tip of each temporary installation pin 25 is brought to the top of the first molding part 181. protruding from the surface. A recess 25a that engages with the lower edge of the sand core is formed on the tip end surface of each plate 3-installation pin 25.

Further, the two first molding parts 1B located on both sides have a first molding part 18. A through hole 29 is formed through the through hole 29, and an operating pin 30 whose lower end is fixed to the mounting plate 26 is slid into the through hole 29. When the mold is opened, the tip of the actuating pin 30 protrudes into the recess 23, and when the mold is closed, it is pushed down by a diameter expanding mechanism, which will be described later. It is designed to be pulled in from the top.

Core holders 31 for actually installing sand cores are provided at two locations in the central portion of the wall defining the second cavity C2 in the first and second side molds 1o+ and toz. Each core holder 31 has a retaining hole 31a for positioning the sand core, and a clamping surface 31 formed on the outer periphery of the opening to clamp the sand core.
It consists of b.

4. A plurality of third cavities C3 for communicating with the first cavities C3 to overflow the molten metal and a fourth cavity C1 for molding a communicating lower are formed in the mold clamping recess 12 of the upper mold 9, and In addition, each third
Through holes 32 and 33 communicating with the cavity C3 and the fourth cavity C4 are formed, respectively.

Closing pins 34 and 35 are respectively inserted into the through holes 32 and 33, and the upper ends of these closing pins 34 and 35 are fixed to a mounting plate 36 disposed above the upper mold 9.

The small diameter portion 3 of each through hole 32, 34 extends upward over a predetermined length from the end communicating with both cavities C, C4.
2a, 33a can be fitted with each closing pin 34, 35 to close the third cavity C3 and fourth cavity C4, but the diameter of the outer portion thereof is larger than the diameter of each closing pin 34, 35, and this As a result, air passages 37,38 are formed between each closing pin 34,35 and each through hole 32,33.

A hydraulic cylinder 39 is interposed between the top surface of the upper die 9 and the mounting plate 36, and the operation of the hydraulic cylinder 39 causes the mounting plate 3 to
6 and lower each small diameter part 32 by each closing pin 34,35.
a, 33a are opened and closed. 40 is a guide rod of the mounting plate 36.

The upper die 9 is provided with a diameter expanding mechanism 41 for holding the sleeve 3 cast into each of the cylinder barrels 11 to 14, and the mechanism 41 is configured as follows.

A through hole 42 whose center line coincides with the extension axis of the operating pin 30 is formed in the upper mold 9, and a support rod 43 is loosely inserted into the through hole 42. The upper end of the support rod 43 is fixed to a bracket 44 erected on the top surface of the upper die 9, and a molten metal intrusion prevention plate 45 is fixed to the lower end thereof. The lower surface of the molten metal intrusion prevention plate 45 is provided with the first molding portion 1 of the lower mold 11.
A convex portion 45a that can fit into the concave portion 23 on the top surface of 81 is formed.

The hollow holding cylinder 46 has a circular outer peripheral surface and a tapered hole 47 with a downward slope from the top to the bottom. The holding cylinder 46 is inserted loosely, and its upper end surface abuts a protrusion 48 protruding from the recess 12 of the upper mold 9, and its lower end surface abuts a molten metal intrusion prevention plate 45. As shown in FIG. 9, a plurality of slot grooves 49 are formed in the peripheral wall portion of the holding cylinder 46, extending radially from the inner and outer peripheral surfaces thereof, alternately and at equal intervals on the circumference.

A hollow actuating rod 50 for expanding the diameter of the holding cylinder 46 is slid onto the supporting rod 43 over substantially the entire length of the supporting rod 43, and the actuating rod 50 is fitted into the tapered hole 47 of the holding cylinder 46. A matching tapered portion 50a,
It consists of a true inner part 50b which is connected to the tapered part 50a and is slidably fitted into the through hole 42 of the upper mold 9 and protrudes from the upper mold 9. A plurality of pins 57 are provided protruding from the tapered portion 50a, and these pins 57 are inserted into pin holes 58 that are long in the vertical direction of the holding tube 46, thereby allowing the rotation of the holding tube 46 while allowing the vertical movement of the tapered portion 50a. A stop is made.

A hydraulic cylinder 51 is fixed to the top surface of the upper mold 9, and a hollow piston rod 53. ．． 53□ passes through the upper end wall and the lower end wall of the cylinder body 54, respectively. The true interior 50b of the actuating rod 50 is inserted into the through hole 55 passing through the hollow piston 52 and the hollow piston rod 53,
A retaining stopper 56 fitted into the annular groove inside 50b thereof
1.56□ hollow piston rod 53. ．． The actuating rod 50 is raised and lowered by means of a hollow piston 52, which is brought into contact with the upper and lower end surfaces of the piston 53. The diameter expanding mechanism 41 is connected to each cylinder barrel 1 of the cylinder block S. ~1. Four machines will be installed to correspond to the above.

10th. FIG. 11 shows a sand core 59 for a water jacket,
The sand core 59 has four cylindrical parts 60.corresponding to the four cylinder barrels 11-14 of the cylinder block S. ~6
In order to form a core main body 61 which is equipped with a core body 61 which is equipped with a core body 61 which is provided with a core body 61 which lacks a surrounding wall that overlaps with the adjacent ones thereof, and a communicating lower part and a reinforcing deck part 8 that communicate the water jacket 6 with the water jacket of the cylinder head, A plurality of protrusions 62 protruding from the upper end surface of the child body 61, two cylindrical portions 60□, 60. It is comprised of baseboards 63 protruding from both outer surfaces of the baseboard.

Each baseboard 63 is formed of a large diameter part 63a that is integral with the core body 61 and a small diameter part 63b that projects from the end surface thereof. In this case, the dimensions of the protrusion 62 are set so that it can be loosely inserted into the fourth cavity C4.

Next, a description will be given of the casting operation of the cylinder block material Sm using the casting apparatus.

First, as shown in FIG. 5, the upper mold 9 is raised, and both opposing molds 10. ．． 10□; IL.

104 are moved away from each other to open the mold. In the diameter expanding mechanism 41, each hydraulic cylinder 51 is operated to lower the operating rod 50 using the hollow piston 52, and the diameter of the holding cylinder 46 is reduced by moving the tapered portion 50a downward. In addition, the hydraulic cylinder 39 on the upper die 9 is operated to raise the mounting plate 36, thereby causing each closing pin 34 to rise.
．． 35 as the third. It is separated from the small diameter portions 32a and 33a communicating with the fourth cavities Cs and Ca. Further, the plunger 16 in the hot water supply cylinder 5 is lowered.

A substantially perfect circular cast iron sleeve 3 is loosely fitted into each holding cylinder 46, the upper end opening of the sleeve 3 is closed by fitting into the convex part 48 of the upper mold 9, and the lower end surface of the sleeve 3 is fitted with a molten metal intrusion prevention plate. The convex portion 45a of 45 is aligned with the lower end surface of the molten metal intrusion prevention plate 45.
The lower end opening of the sleeve 3 is closed. Then, the hydraulic cylinder 51 of the diameter expanding mechanism 41 is operated, and the operating rod 50 is raised by the hollow piston 52 thereof. As a result, the tapered portion 50a moves upward, so that the holding tube 46 expands in diameter, and the sleeve 3 is reliably held in the holding tube 46 by receiving the diameter expanding force.

Fifth. As shown in FIG. 11, cylindrical portions 60 on both sides of the sand core 59. ．． 60. The lower edge is attached to the first molding portions 18 on both sides of the lower die 11. The sand 1 core 59 is temporarily installed by engaging with the recess 25a of each temporary installation pin 25 protruding from the top surface of the sand 1 core.

The two-sided molds 10+ and 10g are moved a predetermined distance in the direction in which they approach each other, and each core holder 31 and each baseboard 63 are engaged to perform the actual installation of the sand core 59.

That is, the small diameter portion 63b of each skirting board 63 in the sand core 59 is fitted into the engagement hole 31a of each core receiver 3, and the sand core 59
In addition, the end surfaces of each large diameter portion 63a parallel to the cylinder barrel arrangement direction abut against the clamping surfaces 31b of each core receiver 31, and the sand core 59 is clamped by the clamping surfaces 31b. Further, the other double-sided molds 103 and 104 are also moved in the same manner.

As shown in FIG. 6, the upper mold 9 is lowered and each sleeve 3 is
are inserted into each of the cylindrical parts 601 to 604 of the sand core 59, and the convex part 45a of the molten metal intrusion prevention plate 45 is fitted into the concave part 23 on the top surface of the first molded part 181. As a result, the molten metal intrusion prevention plate 45
Since the two operating pins 30 are pushed down by the convex portion 45a, each temporary installation pin 24 is lowered and retracted from the top surface of the first molded portion 181.

Further, the mold clamping recess 12 of the upper mold 9 is connected to each side mold 10. ~104
The mold clamping is performed by fitting into the mold clamping convex portion 13 of.

A molten metal made of aluminum alloy is supplied from a melting furnace to the sump 14 of the lower die 11, and the plunger 16 is raised to allow the molten metal to pass through the weir 19 from both runners 17 and into the cavity from the lower edges of both sides in the lateral direction of the second cavity C2. C2 and the first cavity C1 are filled. Gas such as air in both cavities C+ and Cz is pushed up by the molten metal and flows into the third cavity. The air exits above the upper mold 9 through air passages 37, 38 communicating with the fourth cavities C, C4.

In this case, both runners 17 are formed so that the cross-sectional area gradually decreases from the water reservoir 14 side toward the runner light 17a as described above, and the cross-sectional area of the runner 17 or the runner 17 is
Since the cross-sectional areas of both the weir 19 and the weir 19 are set as described above, the molten metal flows from both runners 17 to each layer 19 as the plunger 16 rises.
The molten metal flows smoothly into each part of the lower edge of the second cavity C2 through the molten metal, and at that time, the surface of the molten metal flows into the cavity cz.
It rises almost evenly over the entire area. Therefore, the molten metal does not cause turbulence in both cavities C3 and Cz,
It is possible to prevent gases such as air from being entrained in the molten metal, thereby avoiding the formation of cavities.

Third. When the fourth cavity C3, C, is filled with molten metal, the hydraulic cylinder 39 on the upper mold 9 is operated to lower the mounting plate 36, and the small diameter cavity is connected to both cavities C3, Ca by means of closing pins 34 and 35. The sections 32a and 33a are closed.

In the pouring operation, the second cavity C2 and the first
Plunger 16 for filling cavity CI with molten metal
The displacement and molten metal pressure are controlled as shown in FIG.

That is, the plunger 16 changes its moving speed to the first to third speeds.
It is controlled in three stages, 1 to 3. In this example, the first speed ■
1 is 0.08 to 0.12 m/sec, 2nd speed V2 is 0.14 to 0.18 m/sec, and 3rd speed ■3 is 0.04 to 0.08 to achieve a significant deceleration state. m/se
These three-stage speed controls prevent the molten metal from collapsing, form a quiet molten metal flow that does not involve air or other gases, and efficiently send the molten metal to both cavities C, , C, Can be filled well.

In addition, at the first speed vI of the plunger 16, the molten metal flows through both runners 1
7 etc., the pressure P of the molten metal is kept approximately constant, and the second and third speeds V, , V, of the plunger 16
Since the molten metal fills both cavities C3 and C2, the pressure P2 of the molten metal rises rapidly. 3rd plunger 16
After moving at speed 3 for a predetermined 5 hours, the filling pressure P3 of the molten metal is maintained at 150 to 400 kg/ctll for about 1.5 seconds, thereby completely enveloping the sand core 59 with the molten metal and covering its surface. Forms a molten metal solidification film.

After the time has elapsed, the plunger 16 is moved at a speed v4.
Since the molten metal is moved at a reduced speed, the pressure P4 of the molten metal increases, and when the pressure P reaches 200 to 600 kg/cIIl, the movement of the plunger 16 is stopped and the molten metal is solidified in this state.

If a molten metal coagulation film is formed on the surface of the sand core 59 by keeping the pressure of the molten metal constant for a predetermined period of time as described above, the sand core 59 will be protected by the film and damaged during the next pressurization of the molten metal. There is no.

Also, the sand core 59 expands due to the molten metal, but since the protrusion 62 is loosely inserted into the fourth cavity C4, the sand core 59 expands.
The protrusion 62 follows the expansion of the protrusion 62, thereby preventing the protrusion 62 from breaking.

26-Furthermore, since the sand core 59 is held in an accurate position by the molds 101. The sand core 59 will not float up when the molten metal inside is pressurized. In addition, the end surface of the large diameter portion 63a of each baseboard 63 is
When the sand core 59 tends to swell, the deformation force is supported by each clamping surface 31b, thereby preventing the sand core 59 from deforming and causing each sand core 59 to bulge. A Siamese cylinder barrel 1 having a uniform wall thickness around the sleeve 3 can be obtained.

By controlling the moving speed of the plunger 16 and the pressure of the molten metal as described above, a closed deck type cylinder block material can be cast with substantially the same production efficiency as die casting.

After the molten metal has solidified, the hydraulic cylinder 51 of the diameter expansion mechanism 41 is operated, the operating rod 50 is lowered to remove the diameter expansion force of the holding cylinder 46 against the sleeve 3, and the mold is opened. The cylinder block material Sm shown is obtained.

When the cylinder block material Sm is subjected to a grinding process to remove the protrusions 64 formed by the cooperation between the fourth cavities C4 and the protrusions 62 of the sand core 59, the protrusions 62 cause the lower communication Reinforcement deck portions 8 are formed between adjacent communicating lowers. Thereafter, a water jacket 6 is obtained by removing sand, and the inner circumferential surface of each sleeve 3 is machined into a perfect circle, and other predetermined processing is performed to form a cylinder block as shown in FIGS. 1 to 3. S is obtained.

C0 Effects of the Invention As described above, according to the present invention, there is provided a cavity corresponding to the shape of a cylinder block material for a multi-cylinder internal combustion engine, a pair of runners extending substantially along the lower edges of both sides of the cavity in the lateral direction; A molten metal filling control method in a mold for forming a cylinder block material for a multi-cylinder internal combustion engine, which has a plurality of weirs communicating between runners and the cavities, and a hot water supply section communicating with the upstream end of each runner, The mold has the bottom surface of each runner shaped like an ascending staircase from upstream to downstream, and the top surface of each runner is formed substantially horizontally to reduce the cross-sectional area of each runner stepwise. was used, and by setting the cross-sectional area of the runner, the rise in the level of the molten metal flowing into the cavity from the runner through each layer into the cavity was approximately uniform over the entire area. The upwardly stepped bottom surface of the runner allows the flow rate of the molten metal in the runner to gradually increase as it goes downstream, making it possible to introduce the required amount of molten metal into the cavity without delay even through the weir on the downstream side, which is far away from the hot water supply section. can. 9. In addition, even if the volume distribution of the cavity in the longitudinal direction is not the same in each part due to the complex shape structure of a cylinder block for a multi-cylinder internal combustion engine, the cross-sectional area of the runner can be set to Since the level of the molten metal flowing into the cavity through each layer can be raised almost uniformly over the entire area, gas entrainment into the molten metal can be effectively prevented. The occurrence of cavities in the cylinder block material is avoided and a high quality cylinder block material can be obtained. Furthermore, since the filling of the molten metal into the cavity is performed in an even manner for each part, the filling work can be performed efficiently as a whole, which can contribute to improving the efficiency of the casting work.

[Brief explanation of drawings]

Figures 1 to 3 show a Siamese type cylinder block, Figure 1 is a perspective view seen from above, Figure 20 is a sectional view taken along line ■-■ in Figure 1, and Figure 2A is a cross-sectional view along line ■a-■ in Figure 2.
3 is a perspective view seen from below, FIG. 4 is a perspective view of a Siamese type cylinder block material seen from above, and FIG. 5 is a mold of a casting machine to which an embodiment of the present invention is applied. 6 is a vertical sectional front view of the casting device when the mold is closed; FIG. 7 is a sectional view taken along the line ■-■ of FIG. 6; FIG. 8 is a sectional view taken along the line ■■ of FIG. Figure 9 is a sectional view taken along the line IX-IX in Figure 5, Figure 10 is a perspective view of the sand core seen from above, and Figure 11 is a cross-sectional view taken along the line IX-IX in Figure 5.
FIG. 10 is a sectional view taken along the line X I-X I, and FIG. 12 is a graph showing the relationship between the displacement of the plunger and the pressure of the molten metal over time. A... Hot water supply part, C... Cylinder block molding cavity, M... Mold as a casting mold, Sm... Cylinder block material, 17... Runway, 17b... Bottom surface, 17c... ...Top surface, 19...Weir 31- Figure 4 Figure 3 Figure 1 Figure 2

Claims (1)

[Claims] A cylinder block for a multi-cylinder internal combustion engine, a cavity (C) corresponding to the shape of the material (Sm), and the cavity (C)
A pair of runners (17
), a plurality of weirs (19) that communicate between each runner (17) and the cavity (C), and a hot water supply section (A) that communicates with the upstream end of each runner (17). In a method for controlling molten metal filling in a mold for forming a cylinder block material for an internal combustion engine, the bottom surface (17b) of each runner (17) is formed in an ascending step-like shape from upstream to downstream of each runner (17), and Using the mold (M) in which the top surface (17c) of each runner (17) is formed substantially horizontally and the cross-sectional area of each runner (17) is gradually reduced, By setting the cross-sectional area of , the rise in the level of molten metal in the cavity (C) that flows into the cavity (C) from the runner (17) through each weir (19) is approximately uniform over the entire area. A method for controlling molten metal filling in a mold for forming a cylinder block material for a multi-cylinder internal combustion engine, characterized by: