JPS626761A - Casting method for fiber reinforced cylinder block stock - Google Patents

Abstract

PURPOSE:To obtain a product having high quality by pouring a molten metal into cavities for forming cylinder block stocks from the lower part thereof while holding a cylindrical fiber molding between each core for forming a cylinder bore and each cavity by maintaining a space therebetween. CONSTITUTION:Each core 41 for forming the cylinder bore is loosely fitted into each fiber molding F and the projecting part 41a of the core 41 is fitted into a recess 23 on the peak surface of the 1st molding part 18. Each projection 62 of a sand core 59 is loosely inserted into each cavity C. Molds are clamped after a cope 9 and side molds 101, 102, etc. are fitted to each other. The molten metal is supplied into a pouring basin part 14 of a drag 11 and is poured into the cavities C by using a plunger 16. Gases are vented from vent holes 32, 33. The plunger 16 is accelerated after venting to thoroughly solidify the molten metal under the pressure. The structure of the aluminum alloy is compacted in the above-mentioned manner and the product having the excellent quality is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION A9 Object of the Invention (1) Field of Industrial Application The present invention relates to a method for casting a fiber-reinforced cylinder block material in which the circumference of a cylinder bore is reinforced with a fiber molded body.

(2) Conventional technology Conventionally, when casting this type of cylinder block material, a cylindrical fiber molded body is attached to the outer peripheral surface of a cylinder bore molding core whose axis is arranged horizontally, and then the fiber molded body is surrounded. A method is adopted in which molten metal is injected into the cylinder block material molding cavity from one open end side of the fiber molded body under a predetermined pressure that exceeds atmospheric pressure, and then the molten metal is completely solidified under high pressure that exceeds the above pressure. has been done.

(3) Problems to be Solved by the Invention However, according to the above method, the flow of the molten metal is an axial flow from one open end side of the fiber molded body to the other open end side. There is a problem in that gas such as air is likely to be trapped in the area on the open end side, resulting in the formation of cavities. Furthermore, when the bulk density of the fiber molded body is increased with the aim of improving fiber reinforcement, there is also the problem that the filling properties of the molten metal become poor, making it easy to produce defective products.

An object of the present invention is to provide the casting method that can solve the above problems.

B0 Structure of the Invention (1) Means for Solving the Problems The present invention is directed to a cylinder bore molding machine whose axis is directed in the vertical direction when casting a cylinder block material reinforced with a fiber molded body around the cylinder bore. Loosely fitting a cylindrical fiber molded body onto the outer peripheral surface of the core; narrowing the opening of the gas vent hole in the upper part of the cavity for molding the cylinder block material that surrounds the fiber molded body, and under a predetermined pressure exceeding atmospheric pressure; a step of injecting the molten metal into the cavity from the lower part of the cavity so that the molten metal level rises in a substantially horizontal state; a step of closing the gas vent hole and completely solidifying the molten metal under a high pressure exceeding the pressure; It is characterized by using

(2) A cylindrical fiber molded body is loosely fitted onto the outer peripheral surface of the core with its axis of action facing up and down, and the molten metal is poured into the cavity from the bottom using a push-up method to make the molten metal level approximately horizontal. At the same time, the opening of the gas vent hole is narrowed to maintain the injection pressure of the molten metal at a predetermined pressure above atmospheric pressure, so that the molten metal is injected into the cavity and simultaneously filled into the fiber molded body. is applied to the fiber molded body starting from the inside and outside from the bottom to the top. Further, since gas such as air inside the fiber molded body is pushed out by the molten metal and escapes upward, degassing performance is also good. In addition, gas entrainment into the molten metal can be prevented by raising the molten metal level in a substantially horizontal state.

Furthermore, since the molten metal is completely solidified under a high pressure exceeding the above-mentioned pressure, the molten metal is completely filled into the fiber molded body during the process of increasing the pressure of the molten metal, and the metal structure of the matrix is densified to improve its strength.

(3) Embodiment Figures 1 to 3 show a Siamese-type cylinder block S made of a fiber-reinforced aluminum alloy made of a material obtained according to the present invention, in which a plurality of cylinder blocks S are arranged in series, four in the illustrated example. It is composed of a Siamese cylinder barrel 1 formed by connecting cylinder barrels 11 to 14 with each other, an outer wall 2 surrounding the Siamese cylinder barrel 1, and a crankcase 3 connected to the lower edge of the outer wall 2. . A cylindrical fiber molded body F is embedded around the cylinder bore 4 in each cylinder barrel 11 to 14, and the area around the cylinder bore 4 is reinforced with fibers by this fiber molded body F.

A water jacket 6 facing the entire circumference of the Siamese cylinder barrel 1 is formed between the Siamese cylinder barrel 1 and the outer wall portion 2. At the opening on the cylinder head side of the water jacket 6, the Siamese cylinder barrel l
and the outer wall part 2 are connected by a plurality of reinforcing deck parts 8,
The space between adjacent reinforcing deck portions 8 functions as a communicating lower portion to the cylinder head side. As a result, the cylinder block S is configured into a closed deck type.

Figures 5 to 8 show the cylinder block material S shown in Figure 4.
m (shows a casting device used in the implementation of the present invention, the device is equipped with a mold M, the mold M is arranged below the upper mold 9 and the upper mold 9, which can be raised and lowered, 5. In Fig. 6, the first and second side molds 10..10 are divided into left and right halves.
□, both sides type 10, . It is composed of a lower die 11 on which a 10□ is slidably placed.

On the lower surface of the upper mold 9, both sides mold 10. ．． A mold clamping recess 12 that defines a first cavity CI for molding the Siamese cylinder barrel 1 and outer wall 2 is formed in cooperation with the mold clamping convex 13 that fits into the recess 12. is double-sided type 10. ．． 102 in a protruding manner.

7th. As shown in FIG. 8, the lower mold 11 includes a sump 14 that receives molten aluminum alloy from a melting furnace (not shown), a hot water supply cylinder 15 communicating with the sump 14, and a hot water supply cylinder 15 connected to the sump 14. A plunger 16 to be slid together, and a pair of runners 17 that are branched into two from the tundish portion 14 and extend in the longitudinal direction of the first cavity CI and over approximately the same length as the first cavity CI are provided. The lower mold 11 also has a molding block 18 projecting upward between the two runners 17, and the molding block 18 has a molding block 18 on both sides of the mold 10. ．． 10□ to define a second cavity C2 for molding the crankcase 3. The upper end of the cavity C2 communicates with the first cavity C8, and the lower ends on both sides communicate with both runners 17 via a plurality of weirs 19. These first. 2nd cavity C
+ and Cz constitute a cavity for molding the cylinder block material.

The molding block 18 is located between four tall semi-cylindrical first molding parts 1B formed at predetermined intervals and adjacent first molding parts 188 and outside of the outermost brush 1 molding part 181. It consists of a convex-shaped second molded part 18□, and each first molded part 18. is used to form the crank pin and crank arm rotation space 20 (Figs. 2 and 3),
Second molding section 18. is crank journal bearing holder 2
1 (Figures 2 and 3).

Each layer 19 is provided corresponding to each second molding section 18□, so that the molten metal is quickly injected into the large capacity portion of the second cavity C2.

Both runners 17 are formed such that the bottom surface of the runners 17 is shaped like several steps ascending from the trough portion 14 side so that the cross-sectional area gradually decreases from the trough portion 14 side toward the runner light 17a. There is. Each rising portion 17c connected to each step portion 17b allows the molten metal to flow into each layer 19.
It is formed diagonally so that it can be guided smoothly.

When the cross-sectional area of the runner 17 is reduced in stages in this way,
In areas with large cross-sectional areas, a large amount of molten metal is pumped through the weir 19 at a slow speed.
In the small cross-sectional area, a small amount of molten metal can be injected into the second cavity C2 through the weir 19 at a high speed. The molten metal level rises in a nearly horizontal state, and the molten metal flows into the cavity C.
There is no turbulence within the molten metal, and gases such as air are prevented from being drawn into the molten metal, thereby avoiding the formation of cavities. In addition, since the molten metal injection work is performed efficiently,
Casting efficiency can be improved.

Fifth. As shown in FIG. 6, a positioning protrusion 22 into which the lower end of the fiber molded body F fits is protruded from the top surface of each first molded part 18, and a recess 23 is formed in the center of the positioning protrusion 22. Ru. Also, two first molded parts 18 located on both sides.
On both sides of the positioning protrusion 22, the first molded portion 18.
A through hole 24 is formed passing through the through hole 24, and a pair of temporary installation pins 25 are slid into each of 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 fixed to a mounting plate 26 disposed below the forming block 18. Two support rods 27 are inserted through the mounting plate 26, 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 temporary installation pin 25.

Also, two first molded parts 18 located on both sides. A through hole 29 passing through the first molded portion 18 is formed at a trisecting position between both through holes 24, 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 operating pin 30 protrudes into the recess 23,
Further, when the mold is closed, it is pushed down by a cylinder bore molding core, which will be described later, so that both plate installation pins 25 are retracted from the top surface of the first molding part 181.

First and second side molds10. ．． Core holders 31 for actually installing sand cores are provided at two locations in the center of the wall defining the first cavity C7 in 10□. Each core holder 31 has an engagement hole 31a for positioning the sand core, and a clamping surface 31b formed on the outer periphery of the opening to clamp the sand core.
It becomes more.

A plurality of third cavities C3 for communicating with the first cavity C1 to overflow the molten metal and a fourth cavity C4 for forming a communicating lower are formed in the mold clamping recess 12 of the upper mold 9, and Gas vent holes 32 and 33 are formed in the mold 9 and communicate with the third cavity C3 and the fourth cavity C4, respectively.

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

The small diameter portions 32a, 33a of each gas vent hole 32, 33, which extend upward over a predetermined length from the communicating end with respect to both cavities C1, C4, fit into the lower end of each closing pin 34, 35, and the third Cavity C3 and fourth cavity C4 can be closed.

A hydraulic cylinder 39 is interposed between the upper surface of the upper mold 9 and the mounting plate 36, and the operation of the hydraulic cylinder 39 raises and lowers the mounting plate 36, and each small diameter portion 32a,
33a is opened and closed. 40 is the mounting plate 36
This is the guide rod.

Each cylinder barrel 1 is placed on the top surface of the mold clamping recess 12 of the upper mold 9.
．． - 14, cylindrical cores 41 for forming cylinder bores with their axes facing upward and downward are protrudingly provided, and the lower end surface of each core 41 is provided with a concave portion 23 on the top surface of the first molded portion 18I. A convex portion 41a that can be fitted is provided. Each core 41 is tapered from the upper end to the lower end.

9th. FIG. 10 shows a sand core 59 for a water jacket, and the sand core 59 has four cylindrical portions 60.corresponding to the four cylinder barrels 11-14 of the cylinder block S. ~60
In order to form a core main body 61 which is provided with 4 and lacks the surrounding walls that overlap with each other, and a communicating lower and reinforcing deck part 8 that communicates the water jacket with the water jacket of the cylinder head, A plurality of protrusions 62 protruding from the upper end surface of the main body 61, two cylindrical portions 60□, 60. It is comprised of baseboards 63 protruding from both outer surfaces of the baseboard. Each baseboard 63 has a large diameter portion 63a that is integral with the core body 61, and a small diameter portion 6 that protrudes from the end surface of the large diameter portion 63a.
3b.

Fig. 11 shows a cylindrical fiber molded body F formed from a mixed fiber of carbon fiber and alumina fiber, and its dimensions are an outer diameter of 89M at the upper end, an inner diameter of 78111, an outer diameter of 89M at the lower end, and an inner diameter of It is 74m1 high and 152 cranes, and its bulk density is 0.3g/Cm'. The dimensions of the inner circumferential surface of the fiber molded body F, that is, the tapered surface, are set to be slightly larger than those of the cylinder bore forming core 41.

The fiber molded body F is made of a pair of carbon fibers (short fibers) with an average diameter of 18 μm and an average length of 0°8 mm and alumina fibers (short fibers) with an average diameter of 3 to 4 μm and an average length of 0.5 mm. 3 and 3, silica sol was added as a binder to the mixed fibers, and molded by applying a suction adhesion molding method. In this case, it is possible to use alumina sol alone or a mixture of silica sol and alumina sol instead of silica sol.

The above-mentioned suction adhesion molding method is a method in which a cylindrical mold with air permeability with both ends sealed is erected in a tank containing the mixture of the mixed fibers and silica sol, and a suction action is applied to the inside of the cylindrical mold. A method in which a mixture is adsorbed onto the outer surface of a cylindrical shape.

The fiber molded body formed by the above method is used after being released from the mold and subjected to a drying and firing process.

Next, the casting operation of the cylinder block material Sm by the casting apparatus using the fiber molded body F will be explained.

First, as shown in FIG. 5, the upper die 9 is raised, and both sides of the die 10. ．． Open the mold by moving the 10 squares apart from each other. The hydraulic cylinder 39 on the upper mold 9 is actuated to raise each closing pin 34.35 through the mounting plate 36, and the lower ends of the small diameter portions 32a, 33a communicating with the third and fourth cavities C3, Ca are opened. The opening degree of each upper opening is narrowed by positioning it near the upper opening. Further, the plunger 16 in the hot water supply cylinder 15 is lowered.

The lower opening on the small diameter side of each fiber molded body F preheated to approximately 300°C is connected to each first molded portion 18. Each fiber molded body F is fitted into the positioning protrusion 22 to stand up on the top surface of each first molded part 181. In this case, as shown in FIG. 7A, each fiber molded body F
A gap g is formed between a part of the inner circumferential surface of the lower opening and a part of the outer circumferential surface of the positioning protrusion 22 for allowing the molten metal to enter the inside of the fiber molded body F from the lower part.

Fifth. As shown in FIG. 10, each cylindrical portion 60 in the sand core 59. 604 are loosely fitted on the outside of each fiber molded body F to form a space S therebetween, and the cylindrical portions 60. ．．
The lower edge of 604 is attached to the first molding portions 18 on both sides of the lower mold 11.
The sand core 59 is temporarily installed by engaging with the recess 25a of each temporary installation bin 25 protruding from the top surface of the sand core 59.

As shown in FIG. 6, the two-sided molds 101 and 102 are moved a predetermined distance in the direction in which they approach each other, and
and each skirting board 63, and the sand core 59 is fully installed.

That is, the sand core 59 is positioned by fitting the small diameter portion 63b of each baseboard 63 in the sand core 59 into the engagement hole 31a of each core receiver 31, and also aligning the cylinder barrel arrangement direction of each large diameter portion 63a. The sand core 59 is clamped by the clamping surfaces 31b of each core holder 31 by abutting the end surfaces parallel to the clamping surfaces 31b of each core holder 31.

Next, the upper die 9 is lowered to form each cylinder bore core 4.
1 is loosely fitted into each fiber molded body F, and the convex portion 41a of the core 41
is fitted into the recess 23 on the top surface of the first molded part 181. Since the actuating pin 30 is pushed down by this uneven fitting, each temporary installation pin 25 is lowered and retracted from the top surface of the first molded part 181. In addition, each protrusion 62 of the sand core 59 corresponds to each fourth cavity C4.
Furthermore, the mold clamping recesses 12 of the upper mold 9 fit into the mold clamping protrusions 13 of the both molds 101.10□ to perform mold clamping, and each fiber molded object F and the first molding section 1
It is clamped and fixed between the top surfaces of 81. Furthermore, a predetermined gap g2 is formed between the core 41 and the fiber molded body F, and the gap g2
communicates with the first cavity C1 via the gap g1.

A molten metal made of aluminum alloy (JIS ADC12) at 730 to 740°C is supplied from a melting furnace to the sump 14 of the lower mold 11, and the plunger 16 is heated to a height of 0.08 to 0.3 m.
/sec to raise the molten metal from both runners 17 to weir 1.
9 into the second cavity C2 and the first cavity CI from both lower parts of the second cavity C2. Gas such as air in both cavities C, , C, is pushed up by the molten metal and escapes above the upper mold 9 through gas vent holes 32, 33 communicating with the third and fourth cavities Ci, C4.

In this case, both runners 17 are formed in the shape of several steps ascending from the trough portion 14 side so that the cross-sectional area of both runners 17 gradually decreases toward the runner light 17a, as described above. As the plunger 16 rises, the molten metal flows from both runners 17 to each layer 1.
9 and is injected into the second cavity C2 from both lower portions thereof substantially uniformly over its entire length.

By applying this push-up method, the hot water level rises in a substantially horizontal state in the second cavity C2 and the first cavity C8 including the space S and the gap g2, and at the same time
．． Since the opening degree of the small diameter portions 32a and 33a in 33 is narrowed, the injection pressure of the molten metal becomes a pressure pl exceeding atmospheric pressure as shown in FIG. 12, and as a result, the molten metal is injected into the first cavity CI. At the same time, filling of the molten metal into the fiber molded body F starts from the bottom to the top from the inside and outside. Furthermore, gas such as air within the fiber molded body F is pushed out by the molten metal and escapes upward, resulting in good degassing performance. Moreover, since the molten metal level rises in a substantially horizontal state, entrainment of gas into the molten metal is prevented, and therefore the generation of cavities is avoided.

Third. When the molten metal is completely injected into the fourth cavities Cz and C4, the hydraulic cylinder 39 on the upper mold 9 is operated to lower the mounting plate 36, which communicates with both cavities C3 and C4 through the closing bins 34.35. Small diameter portions 32a, 33a
will be closed.

After that, plunger 16 is rotated at 0.14 to 0.18 m/se.
The molten metal is raised at a rate of C under a high pressure pz exceeding the pressure p, that is, 400 kg/an! The aluminum alloy is held under pressure to completely solidify it, thereby densifying the structure of the aluminum alloy matrix and improving its strength. When the pressure of the molten metal reaches 5 to 20 kg/ci in the process of increasing the pressure of the molten metal, the filling of the molten metal into the fiber molded body F is completed.

Since the pressure at which the filling of the molten metal is completed is low as described above, the fiber molded body F is not destroyed by the molten metal during filling.

Each fiber molded body F is clamped and fixed between the top surface of the recess 12, the first molded portion 18, and the top surface, so when pouring the molten metal into the first cavity C2 and pressurizing the molten metal in the cavity C5. In this case, each fiber molded body F does not move, so that the area around the cylinder bore 4 can be reliably reinforced with fibers. Furthermore, since the sand core 59 is held in an accurate position by the molds 101. It never floats up. In addition, the end surfaces of the large diameter portions 63a of each baseboard 63 are double-sided type 10+, 10z.
When the sand core 59 tends to swell, the deformation force is supported by each clamping surface 31b, which prevents the sand core 59 from deforming. Thus, a Siamese cylinder barrel 1 having uniform wall thickness around each cylinder bore 4 can be obtained.

After the molten metal has completely solidified, the mold is opened to obtain the cylinder block material Sm shown in FIG. 4.

When the cylinder block material Sm is subjected to a grinding process to remove each protrusion 64 formed by the cooperation of each fourth cavity C4 and each protrusion 62 of the sand core 59, each communicating lower and reinforcing deck portion 8 is formed. The water jacket 6 is obtained by removing sand, and the inner circumferential surface of each cylinder bore 4 is machined into a perfect circle to remove the aluminum alloy portion filled in the gap g2, and other predetermined processes are performed. By performing the above processing, the cylinder block S shown in FIGS. 1 to 3 is obtained.

Note that the fiber molded body F may be molded from one type of reinforcing fiber. In addition to the aluminum alloy, cast iron, copper, magnesium alloy, etc. may be used as the matrix.

C0 Effects of the Invention According to the present invention, a cylindrical fiber molded body is loosely fitted into a cylinder bore molding core whose axis is directed in the vertical direction, and molten metal is injected into the cylinder block material molding cavity from the lower part of the core. A push-up method is applied to raise the molten metal level in a nearly horizontal state, and at the same time, the opening of the gas vent hole is narrowed to maintain the molten metal injection pressure at a predetermined pressure above atmospheric pressure. Simultaneously with the injection, filling of the molten metal into the fiber molded body starts from the inside and outside of the fiber molded body from the bottom to the top, improving the filling efficiency of the molten metal.

Further, gas such as air inside the fiber molded body is pushed out by the molten metal and escapes upward, thereby preventing gas from being trapped in the fiber molded body. Further, the rising of the molten metal level in a substantially horizontal state prevents gas from being drawn into the molten metal.

After that, the molten metal is completely solidified under high pressure exceeding the above pressure, so that the molten metal completely fills the fiber molded body during the process of increasing the pressure of the molten metal, and the filling property of the molten metal is good even if the bulk density of the fiber molded body is high. Become. Furthermore, the metal structure of the matrix becomes denser and its strength improves.

Therefore, by employing the above method, it is possible to efficiently cast a high-strength fiber-reinforced cylinder block material that is reliably fiber-reinforced around the cylinder bore and free from the occurrence of cavities.

[Brief explanation of drawings]

1 to 3 show a Siamese type cylinder block made of the material obtained according to the present invention, FIG. 1 is a perspective view seen from above, FIG.
The figures are FIG. 9, a sectional view taken along the line X-X, FIG. 3, a perspective view from below, FIG. 4, a perspective view from above of the Siamese-type cylinder block material obtained by the present invention, and FIG. FIG. 6 is a longitudinal sectional front view of the casting device when the mold is opened, FIG. 7 is a sectional view taken along the line XX of FIG. 9, and FIG. 7A is a sectional view of the casting device when the mold is closed. Line sectional view, Figure 8 is Figure 9 X-X
Line sectional view, Figure 9 is a perspective view of the sand core seen from above, Figure 1
0 is a sectional view taken along the line X-X in FIG. 9, FIG. 11 is a perspective view of the fiber molded body, and FIG. 12 is a graph showing the relationship between the pressure of the molten metal and time. C+, Cz... The first composing the cylinder block material molding cavity. 2nd cavity, F...fiber composition body, Sm...Siamese type cylinder block material,
4... Cylinder bore, 32.33... Gas vent hole,
41... Core patent applicant Honda Motor Co., Ltd. Figure C procedural amendment (,e) October 1985 - 30 1,9 Office Director's Palace 1, case indication 1985 patent application No. 146994 2, Name of the invention Casting method for fiber-reinforced cylinder block material 3, Relationship with the person making the amendment Case Name of patent applicant (532) Honda Motor Co., Ltd. 4, Representative
Director 105 Telephone Tokyo 434-4151 5 Contents of the amendment subject to amendment (The entire text of 11 specifications is corrected as shown in the attached sheet. (2) Please note that the code r in Figure 7 of the drawing is not included in the attached drawing.
lO,'' was corrected to r 10'l J, and the symbol rlO
, J. 1. Title of the invention Method for casting fiber-reinforced cylinder block material 2. Claims When casting a cylinder block material whose circumference around the cylinder bore is reinforced with a fiber molding, the axis line is Cylinder bore molding core arranged facing the direction - 6mm long outer U
! Keeping the cylindrical fiber molded body in a loose fit relationship,
Between the core and the front 3[F]NjiilUrM shape, there is a picture of the lower plate of the cavity for forming the cylinder block material surrounding the fiber molded body.
- Narrow down the opening of the gas vent hole in the seventh part of the restaurant, and enter the cavity and the stop from the bottom of the cavity? A method for casting a fiber-reinforced cylinder block material 3, characterized by using the following steps: closing the gas vent hole, pressurizing the molten metal, and completely solidifying it under the pressure.
, Detailed Description of the Invention A Object of the Invention (1) Industrial Application Field The present invention relates to a method for casting a fiber-reinforced cylinder block material in which the circumference of a cylinder bore is reinforced with a fiber molded body. (2) Conventional technology Conventionally, when casting this type of cylinder block material, a cylindrical fiber molded body is attached to the outer peripheral surface of a cylinder bore molding core whose axis is arranged horizontally, and then the fiber molded body is surrounded. A method is adopted in which the molten metal is injected from one end side of the fiber molded body into the cylinder block material molding cavity, and then the molten metal is pressurized and completely solidified under the pressure. (3) Problems to be Solved by the Invention However, according to the above-mentioned method, the molten metal flows in the axial direction from one end of the fiber molded body to the other end, so the molten metal tends to entrain gas. Gas is likely to be trapped in a portion of the fiber material that corresponds to the other end of the fiber molded article. As a result, there is a problem that cavities occur in the cylinder block material. The object of the present invention is to provide a casting method that can solve the above problems. B9 Structure of the Invention + 11 Means for Solving Problems The present invention involves casting a cylinder block material reinforced with a fiber molded material around the cylinder bore. and a cylindrical fiber molded body disposed on the outer periphery of the core and a cylindrical fiber molded body disposed on the outer periphery of the core, and a cylinder block material for forming a cylinder block material surrounding the fiber molded body is placed between the core and the fiber molded body. a step of forming a gap communicating with the lower part of the cavity; a step of narrowing down the opening for gas venting in the upper part of the cavity, and injecting molten metal into the cavity and the gap from the lower part of the cavity; and forming the gas vent hole described in iii. The molten metal is closed, pressurized, and completely solidified under the pressure. (2) Action: At the same time, inject 8-8 (from the F part of the toyabitei) into the toyabitei, open the gas vent hole [1 through -1-
Since gas is vented within the cavity, the back pressure within the cavity is constant 4+EL due to the throttling effect of the opening, and this back pressure acts equally on the entire hot water surface. As a result, the molten metal surface overcomes the ripples and rises approximately horizontally, thereby preventing gas from being entrained in the molten metal and efficiently degassing. Furthermore, since the molten metal is pressurized and completely solidified under that pressure, the molten metal is filled with the molten metal from the inside and outside during the process of increasing the pressure of the molten metal. becomes denser and its strength improves. (3) Embodiment Figures 1 to 3 show a Siamese-type cylinder block S made of a fiber-reinforced aluminum alloy made of a material obtained according to the present invention. An example is a Siamese cylinder barrel 1 formed by connecting four cylinder barrels 11 to 14 to each other, and a Siamese cylinder barrel 1. It is composed of a sloped outer wall part 2 and a crank case 3 connected to the lower edge of the outer wall part 2. A cylindrical fiber molded body 1.'' is embedded around the cylinder bore 4 in each cylinder barrel 11 to 14, and the area around the cylinder bore 4 is reinforced with fibers by this fiber molded body F. A water jacket 6 facing the outer periphery of the Ziamese cylinder hull 1 is formed between the Ziamese cylinder hull 1 and the outer wall portion 2. At the cylinder head side end of the water jacket 6, the Siamese cylinder barrel 1 and the outer wall 2
The spaces between the reinforcing deck parts 8 are partially connected by a plurality of reinforcing deck parts 8, and the adjacent reinforcing deck parts 8 function as a continuous lower part to the cylinder head side. As a result, the cylinder block S is configured into a closed deck type. 5 to 8 show a casting device used in the practice of the present invention to cast the cylinder block material S nt shown in the 4th FA, and the device is equipped with a mold M, which can be moved up and down. An upper mold 9 and a fifth mold disposed below the upper mold 9.
In FIG. 6, the first and second side molds 10 are divided into left and right halves.
．． 10□ and the third and fourth side molds 103 and 104 divided into left and right halves in FIG.
It is composed of a lower die 11 on which O2 is slidably placed. On the lower surface of the upper mold 9, each side mold 10. The four mold clamping parts 12 that define the first cavity C1 for molding the Siamese cylinder barrel 1 and the outer wall part 2 in cooperation with the upper half of ~104 are formed, and are fitted into the respective recesses 12. Matching mold clamping convex portions 13 are provided protrudingly on the upper surface of each side mold 10, to 104. 7th. As shown in FIG. 8, the lower mold 11 includes a sump 14 that receives molten aluminum alloy from a melting furnace (not shown), a hot water cylinder 15 communicating with the sump 14, and a hot water cylinder L5. The plunger 1G to be slid together and a pair of fields '1fj 17 which are branched into two branches from the water reservoir part I4 and extend over approximately the same length in the longitudinal direction of the first cylinder bit CI. provided. The mold 11 also has a molding block 1B projecting upward between the two runners 17, and the molding block 18 is connected to each side mold 10. ~The second part for forming the crankcase 3 by working with the lower half of lo4
A cavity C2 is defined. The upper end of the cavity C2 communicates with the first cavity CI, and the lower ends on both sides communicate with both runners 17 via a plurality of weirs 19. These first. The second cavity c1°C2 constitutes a cavity for molding the cylinder block material. The molding block 18 includes four tall semi-cylindrical first molding parts LL formed at predetermined intervals, and adjacent first molding parts 18. and a convex-shaped second molding part 182 located between and outside of the outermost brush 1 molding part IL, and each first molding part 18. is used to form the crank pin and crankcase, and the rotating space 20 (Figs. 2 and 3).
The second molded part 182 is the bearing holder 2 of the crank journal.
1 (Figures 2 and 3). Each layer 19 is provided corresponding to each second molded part 18□, and is provided in a large capacity part of the second cavity C2. 8 Hot water is injected early. The bottom surface of the runner 17 is formed in the shape of several steps from the sump portion 14 side so that the cross-sectional area of both runners L7 gradually decreases from the sump portion I4 side toward the runner light 17a. has been done. Each rising portion 17c connected to each step portion 17b allows the molten metal to flow into each layer 19.
It is formed diagonally so that it can be guided smoothly. When the cross-sectional area of the hot water 1fi17 is reduced in stages in this way, in the part with a large cross-sectional area, a large amount of molten metal is injected into the second cavity C2 through the weir 19 at a slow speed, and in the part with a small cross-sectional area, a small amount of molten metal is injected into the second cavity C2. Since the molten metal can be injected into the second cavity C2 through the weir 19 at a high speed,
The molten metal is injected into the -1-yabity C2 substantially uniformly over the entire length of the runner 17. Further, since the molten metal injection work is performed efficiently, casting efficiency can be improved. Fifth. As shown in FIG. 6, a positioning protrusion 22 is protrudingly provided on the top surface of each first molded part 181, with which the lower part of the fiber molded body F is fitted. It is formed. Also, two first molded parts 18 located on both sides. On both sides of the positioning protrusion 22, the first molded portion 18. A through hole 24 is formed passing through the W through hole 24, and a pair of temporary installation pins 25 are slid into each of the W through holes 24, respectively. These temporary iη pins 25 are used for temporary installation of a sand core for a water jacket, which will be described later. The lower end of both plate installation bins 25 is attached to a mounting plate 2 disposed below the molded block 18.
It is fixed at 6. 2 wooden support rods 2 on its mounting plate 26
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 connected to the first molded part 18, It protrudes from the top. Four portions 25a that engage with the lower edge of the sand core are formed on the tip end surface of each temporary installation pin 25. In addition, a through hole 29 is formed in the two first molded parts 18 located on both sides to pass through the first molded part 18 at a trisecting position between both page through holes 24, and the iT through hole 29 has a lower end. The operating pin 30, which is fixed to the mounting plate 26, is slid together. When the mold is opened, the tip of the operating pin 30 protrudes into the recess 23, and when the mold is closed, it is pushed down by a cylinder bore molding core, which will be described later.
Molding part 18. 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 center of the wall defining the first cavity C2 in the first and second side molds 101.10□. Each core holder 31 has an engagement hole 31a for positioning the sand core, and a clamping surface 31b formed on the outer periphery of the opening to clamp the sand core.
It becomes more. In the mold clamping recess 12 of the upper mold 9, in the first cavity C2 &
A plurality of third cavities C3 for overflowing the yongyang (throughout) and a fourth cavity C4 for molding the continuous 1ff1 lower are formed, respectively, and each of the third cavities C4 and the 44th cavity C4 are formed in the upper mold 9. , l are formed, respectively. Closing pins 34 and 35 are loosely inserted into these gas vent holes 32 and 33, respectively, and the upper ends of these closing IR1 bins 34 and 35 are fixed to a mounting plate 36 disposed above the second mold 9. Each gas vent hole 32.33, both -1-yabity C3°C
Small-diameter portions 32a and 33a extending from the communicating end for 4 to one side over a predetermined length are fitted with the lower end of each closing pin 3.1°35 to close the third cavity C3 and the fourth cavity C4. It is possible to do it. Three hydraulic cylinders are interposed between the upper surface of the upper die 9 and the mounting plate 36, and the operation of the three hydraulic cylinders raises and lowers the mounting plate 36, and each small diameter portion 32a,
33a is opened and closed. 40 is the mounting plate 36
The guide is 1 node. On the top of the four mold clamping parts 12 of the upper mold 9, each
Corresponding to numbers 1 to 14, cylindrical cores 41 for forming cylinder bores are provided with their axes facing downward at 1-.0,
The first molded portion +8. Convex portions 41a that can fit into the four portions 23 on the top surface are provided. Each core 41
Upper ◇: L; It is tapered so as to taper toward the lower end. 9th. FIG. 10 shows a water jacket river sand core 59, which has four wooden cylindrical sections 60.corresponding to the four cylinder barrels l, 14 of the cylinder block S. ~60
4 and the core body 61 is missing the surrounding walls that match the adjacent ones 111, and the water jacket is in the water jacket of the cylinder head! In order to form a communicating lower and reinforcing deck part 8, a plurality of protrusions 62 protrude from the upper end surface of the core body 61, and a plurality of protrusions 62 are provided on both outer surfaces of the core body 61 in the cylinder barrel arrangement direction, in the illustrated example, at the middle. It is composed of baseboards 63 protruding from both sides of the two cylindrical parts 60□ and 603 located therein. 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. Fig. 11 shows a cylindrical fiber molded body F formed from a mixed fiber of carbon fiber and alumina fiber, and its dimensions are an outer diameter of 89 mm at the upper end, an inner diameter of 78 mm, an outer diameter of 89 mm at the lower end, and an inner diameter of 89 mm. 74 dragon height is 1520-, and its bulk density is 0.3 g/c1. The dimensions of the inner circumferential surface of the fiber molded body F, that is, the tapered surface, are set to be slightly larger than those of the cylinder bore forming core 41. The fiber molded body F has an average diameter of 18 tt m and an average length of 0.
゜8-maro carbon fiber (short fiber) and average diameter 3-477
m, and alumina fibers (short fibers) with an average length of 0.5 mm.
The fibers of Pair 3 were mixed by merging, silica sol was added as a binder to the mixed fibers, and molded by applying a suction adhesion molding method. In this case, it is possible to use an alumina sol propellant or a mixture of silica sol and alumina sol instead of silica sol. The above-mentioned suction 41-layer molding method is a method in which a cylindrical mold with air permeability with both sides of N; The mixture is sucked onto the outer circumferential surface of the cylindrical shape by applying a suction action. This refers to the method of making i. The fiber molded body formed by the above method is used after being released from the mold and subjected to a drying and firing process. Next, the casting operation of the cylinder block material 6m by the casting apparatus using the fiber molded body F will be explained. First, as shown in FIG. 5, the upper mold 9 is raised, and the opposing molds 101, 102; The hydraulic cylinder 39 on the upper mold 9 is actuated to raise each closing pin 34.35 through the mounting plate 36, so that their lower ends are connected to the third. Small diameter portions 32a, 33 communicating with the fourth cavity C3°C4
The opening of each upper opening is narrowed by placing it near the frontage of part a. Further, the plunger 16 in the hot water supply cylinder 15 is lowered. The lower opening on the small diameter side of each fiber molded body F preheated to approximately 300°C is connected to each first molded portion 18. b on the positioning protrusion 22 of
Each fiber molded body F is placed upright on the top surface of each first molded portion 18+ by aligning the fibers F with each other. In this case, as shown in FIG. A gap g+ is formed for entering the inside from the lower part. Fifth. As shown in FIG. 10, the cylindrical portions 601 to 604 of the sand core 59 are loosely fitted to the outside of each fiber molded body F to form a space S therebetween, and the cylindrical portions 60 . ．．
The lower edge of 604 is attached to the first molding portions 18 on both sides of the lower mold 11.
．． The sand core 59 is temporarily installed by engaging with the four parts 25a of each temporary installation pin 25 protruding from the top surface of the sand core 59. As shown in FIG. 6, both sides type 10. ．． 10□ by a predetermined distance in the direction in which they approach each other, and
and each skirting board 63, and the sand core 59 is fully installed. That is, the sand core 59 is positioned by fitting the small diameter portion 63b of each skirting board 63 in the sand core 59 into the engagement hole 31a of each core holder 31, and also aligning the cylinder of each large diameter portion 63a. The 5::j plane parallel to the barrel arrangement horn direction is the clamping surface 31 of each core receiver 31.
To b? The sand cores 59 are held together by the holding surfaces 31b. Similarly, the other side molds 10z and 104 are made to have one hyperactivity. Next, the mold 9 is lowered to loosely place each cylinder bore molding core 41 into each fiber molded body F, and the convex part 41a of the core 4J is fitted into the first molded part 18 and the recess 23 on the If surface. do. As the actuation bin 30 is pushed down by this uneven fitting, each temporary installation pin 25 descends and the first molded part 18.
Pull in from the top. In addition, each protrusion 62 of the sand core 59
The mold clamping recess 12 of the upper mold 9 is loosely inserted into the cavity C4, and each side mold 10, to 10. Mold clamping is performed by fitting into the mold clamping convex portion 13 of the mold clamping convex portion 13, and each fiber molded body F is fitted between the top surface of the recess portion 12 and the first molded portion 18. It is clamped and fixed between the top surfaces. Furthermore, a predetermined gap g2 is formed between the core 41 and the fiber molded body 1-', and the gap g2 communicates with the lower part of the first cavity C1 via the gap g1. Heat the melting furnace to 730 to 740°C in the sump 14 of the lower mold 11.
Aluminum alloy (JIS)＼D e l 2)
Supply a /8 positive and plunger 16 from 0.08 to
The soil was moved at a speed of 0.3 m/sec, and the soil was moved from the road 17 through the weir 19 to the second cavity C2.
Inject from both lower parts of the ;)-Yabi-i C2, first cavity C1, and eight gaps. Both cabs C3,
The gas such as air in C2 is pushed up by the )8 field and is pushed up by the 3rd field. It exits to one side of the -1 mold 9 through the gas vent holes 32 and 33 communicating with the fourth cavity CI and C4. In this case, as mentioned above, Ryoon i! The bottom surface of the runner is formed in the shape of several steps from the sump portion 14 side so that the cross-sectional area of Therefore, the temperature of the molten metal is 1i1
7, it is injected into the second cavity C2 through the winter clothes 19 almost equally over the entire length of both lower portions of the second cavity C2. Also, 1st. Is there melting in the second cavity C1, Cz?
When carrying L people, close the bottle and release the gas from the 34.354 bottle.
Since the opening degree of the small diameter portions 32a and 33a at L32.33 is narrowed, the first. Back pressure is generated within the second cavities C, C2, and each back pressure acts equally on the entire surface of the cavity. As a result, the undulating surface is suppressed and rises substantially horizontally, thereby preventing gas from being entrained in the molten metal, and degassing efficiently, thereby avoiding the formation of cavities. Due to the back pressure, the elution injection pressure in the first, second, and second cavities c, CZ becomes a pressure p1 north of atmospheric pressure, for example, 2 to 5 kg/c, as shown in Fig. 12. . Furthermore, since the fibrous molded body F is preheated to the above temperature, the molten metal is kept warm, thereby preventing the molten metal from adhering to the fibrous molded body F. Third. When 78 hot water is completely injected into the fourth cavity C1, C, the second hydraulic cylinder 39 of the mold 9 is activated, the mounting +S, 36 is lowered, and the pin 34, . 35, the small diameter portion 32a communicates with both cavities C1, C44. 'Close l+. Then plunge +l (i 0.14~O, 18m/=,
ac speed 1-, 'j knee 7 yang, [1:
1. Under high pressure p2 exceeding pressure pI, i.e. 400 k>
It is held under H/aII pressure to completely harden the aluminum alloy, which is 7 trinox, to densify the structure of the aluminum alloy and improve its strength. During this elution pressure-1'-gastric process, the hot wire molded body F is filled with the molten metal from the inside and outside at a pressure of 5 to 20 kg/cIIt. In this way, the filling pressure for elution is (l), so during filling the fiber v1
The molded body F will not be easily destroyed. Each fiber VIE molded body “?” indicates the concave portion 12 top surface and the first molded portion 18
Since it is clamped and fixed between , Y and 100 sides, when the 8th cedar ring is inserted into the first cavity C1 and its cahiai C
When pressurizing the molten metal in I, each fiber molded body 1? does not move, and therefore the area around the four cylinder bores can be reliably reinforced with fibers. Also, the sand core 59 is inserted into both side molds 10 through each baseboard 63 of the sand core 59 . ．． Since the sand core 59 is held in an accurate position by the sand core 59, the sand core 59 does not float up during the injection of the molten metal and the pressurization of the molten metal. Further, the end surfaces of the large diameter portions 63a of each baseboard 63 are both side type 10. ．． Since it abuts against the clamping surface 31b of the core support 31 at 102, when the sand core 59 tends to swell,
The deforming force is supported by each clamping surface 31b, thereby preventing deformation of the sand core 59, and obtaining a Siamese cylinder barrel l having a uniform wall thickness around each cylinder bore 4. After the molten metal has completely solidified, the mold is opened to obtain the cylinder block material Sm shown in FIG. 4. When the cylinder block material Sm is subjected to 1iJF machining to remove each protrusion 64 formed by the cooperation of each fourth cavity C4 and each protrusion 62 of the sand core 59, each communicating lower and reinforcing deck part 8 are removed. The inner circumferential surface of each cylinder bore 4 is machined into a perfect circle to obtain a gap g of 1111.
By removing the aluminum alloy portion filled in 2 and performing other predetermined processing, the cylinder block S shown in FIGS. 1 to 3 is obtained. Note that the fiber molded body F may be molded using one type of reinforcing heat 11. In addition to the aluminum alloy, cast iron, copper, magnesium alloy, etc. can be used as the matrix. C1 Effects of the Invention According to the present invention, molten metal is injected from the lower part of the toyabity for cylinder block material molding, and at the same time gas is vented from the cavity through the opening of the gas vent hole whose opening is narrowed. The back pressure generated in the cavity due to the squeezing effect acts uniformly on the entire hot water surface, and as a result, the ripples of the hot water surface are suppressed and the water rises almost horizontally.
The dirt prevents the entrainment of molten metal and gas, and also allows for efficient degassing. Furthermore, since the molten metal is filled from the inside and outside of the fiber molded body, the filling efficiency of the melt 115 into the fiber molded body can be improved. Moreover, since the molten metal is completely solidified under pressure, the metal structure of the matrix can be densified and its strength can be improved. Therefore, by adopting the above-mentioned method, it is possible to efficiently cast a high-strength fiber-reinforced cylinder cylinder material with no cavities, which is reliably fiber-reinforced around the cylinder bore. 4. Brief explanation of drawings No. 1 3 to 3 show Siamese-type cylinder tabs i:I made of the material obtained according to the present invention.
The figure is a perspective view seen from above, and Figure 2 is the 1st lAll-■
2A is a sectional view taken along line II a - II a in FIG. 2, FIG. 3 is a perspective view taken from below, and FIG. Fig. 5 is a longitudinal sectional front view of the casting device when the mold is opened, Fig. 7 is a longitudinal sectional front view of the casting device when the mold is closed, and Fig. 7 is a sectional view taken along the line X-X in Fig. 9. , Fig. 7A is a sectional view taken along line J in Fig. 7, Fig. 8 is a sectional view taken along line XX in Fig. , FIG. 1θ is a sectional view taken along the line X-X in FIG. 9, FIG. 11 is a perspective view of the fiber molded product, and FIG. 12 is a +i? It is a graph showing the relationship between pressure and time of 'b4.

Claims (1)

[Claims] When casting a cylinder block material reinforced with a fiber molded body around the cylinder bore, a step of loosely fitting a cylindrical fiber molded body onto the outer peripheral surface of a cylinder bore molding core arranged with its axis directed in the vertical direction; The opening of the gas vent hole at the top of the cavity for molding the cylinder block material that surrounds the fiber molded body is narrowed, and the molten metal is poured into the cavity from the bottom of the cavity under a predetermined pressure exceeding atmospheric pressure, with the molten metal level rising in a substantially horizontal state. A method for casting a fiber-reinforced cylinder block material, the method comprising: injecting the material so that the gas vent hole is closed and completely solidifying the molten metal under a high pressure exceeding the pressure.