JPS61142350A - Siamease type cylinder block - Google Patents

Abstract

PURPOSE:To enhance the efficiency of radiation from a cast iron sleeve, by removing a cast skin on the outer peripheral surface of a cast iron sleeve adapted to be cast in an aluminum alloy cylinder barrel, all over the surface thereof, and by forming annular or spiral come-off checking grooves in the outer peripheral surface of the sleeve. CONSTITUTION:A Siamease type cylinder block is composed of a Siamease cylinder barrel 1 formed by coupling four cylinder barrels 11-14, an aluminum alloy cylinder block body 2 consisting of an outer wall 4 surrounding the cylinder barrel 1 and a crankcasing 5 and cast iron sleeves 3 each cast in each of the barrels 11-14. Before being cast into the barrel, the cast skin of each sleeve 3 is removed all over the outer peripheral surface thereof by means of a machining work. Further, a plurality of annular come-off checking grooves (g) having a minor arc cross-sectioned shape are formed in the outer peripheral surface of the sleeve at predetermined pitches at least over a predetermined distance from the cylinder head side end section by mean of a machining work.

Description

[Detailed Description of the Invention] A0 Objective of the Invention +1) Industrial Application Field The present invention relates to a Siamese type cylinder block, particularly a Siamese type cylinder block in which a plurality of cast iron sleeves are cast into a plurality of aluminum alloy cylinder barrels arranged in series. Regarding improvements.

(2) Prior Art Conventionally, in a cylinder block having the above structure, an as-cast sleeve is cast into each cylinder barrel. Further, on the outer circumferential surface of each sleeve, annular or spiral retaining grooves are formed along the circumferential direction over a predetermined length from the end on the cylinder head side at a predetermined pitch by a mold when the sleeve is cast.

(3) Problems to be solved by the invention However, when an as-cast sleeve is used, the outer circumferential surface has microporosity, which impedes the close contact between the molten metal and the sleeve, causing microscopic particles between the sleeve and the cylinder barrel. Creates a gap. In the Siamese type cylinder block, adjacent sleeves are very close to each other, and there is generally no water jacket between them, so the heat from the opposing parts of both sleeves is transferred through the cylinder barrel between them. The shortest way is to conduct heat to the water jacket, but if the minute gap is created on the outer circumferential surfaces of opposing parts of both sleeves, the conduction path will be blocked and the heat dissipation from the sleeve will be uniform around its circumference. This reduces the heat dissipation efficiency of the sleeve.

Further, when each of the retaining grooves is formed using a mold, there are many variations in the depth thereof, and the wall thickness of the sleeve at the retaining groove and the land portion between adjacent retaining grooves becomes non-uniform.

When an engine is assembled and operated using such a cylinder block, the amount of thermal expansion around the circumference of the sleeve becomes uneven, creating a gap between the piston ring and the sleeve, increasing blow-by gas and causing oil leakage. This causes problems such as wasteful consumption.

In view of the above, an object of the present invention is to provide the Siamese-type cylinder block, in which the amount of thermal expansion around the circumference of each sleeve during engine operation is approximately equalized.

B0 Structure of the Invention (Means for Solving Problem 11) The outer peripheral surface of the sleeve in the Siamese type block according to the present invention has the casting surface removed over its entirety, and the outer peripheral surface has a molded surface on the cylinder head side. It is characterized in that annular or spiral retaining grooves are formed along the circumferential direction over a predetermined length from the end portion at a predetermined pitch.

(2) Effect When the casting surface is removed from the entire outer circumferential surface of the sleeve, the adhesion between the sleeve and the molten metal becomes good, and there is no minute gap between the sleeve and the cylinder barrel, and the heat dissipation from the sleeve becomes more efficient around its circumference. It is done evenly around the circumference. Further, since the surface area of the sleeve is expanded by the retaining groove, the heat dissipation efficiency of the sleeve is improved in combination with the above-mentioned good adhesion. Furthermore, the wall thickness of the sleeve at the retaining groove and the land portion becomes uniform.

As a result, the amount of thermal expansion around the circumference of each sleeve during engine operation becomes approximately equal.

(3) Embodiment FIGS. 1 to 3 show a Siamese-type cylinder block S according to the present invention, which is an aluminum alloy cylinder having a plurality of cylinder barrels 11 to 14 arranged in series, and in the illustrated example, four cylinder barrels 11 to 14. It consists of a block body 2 and a cast iron sleeve 3 which is cast into each cylinder barrel 11 to 14 to form a cylinder bore 3a. The cylinder block body 2 includes each cylinder barrel l, ~1. The cylinder barrel row 4 is an assembly of cylinder barrels 4, and a crankcase 5 is integrally provided at the lower edge of the cylinder barrel row 4. A plurality of communicating lowers in the water jacket 6 toward the cylinder head side are opened at the upper end surface of the cylinder barrel row 4 so as to surround each cylinder bore 3a, and a reinforcing deck portion 8 is provided between adjacent communicating lowers. As a result, the cylinder block S is configured as a closed deck type. Before casting, the outer circumferential surface of the sleeve 3 is machined to remove the casting surface over its entire circumference, and as shown in FIG. In the illustrated example, a plurality of annular retaining grooves g having a sub-arc cross section are formed by machining at a predetermined pitch over the entire length.

The dimensions of each retaining groove g are, where the inner diameter of the sleeve 3 is D, the groove depth is a-0,002D to 0.02D, and the groove pitch is b.
=0.01D~0.100. Groove radius C=0°002D
~0.04D, respectively.

0 indicates the center of the groove C.

The reason why the dimensions of each retaining groove g are limited in this way is that when the groove depth a is less than 0.002D, the anchoring effect of each retaining groove g decreases, and the sleeve 3 becomes attached to the cylinder barrel 11.
~l, it becomes easier to come out, and on the other hand, when it exceeds 0.02 D, the molten metal enters each retaining groove g. This is because a gap is likely to occur between 14 and 14. Also, the groove pitch b is 0. Sleeve 3 when below OID
On the other hand, if the ring rigidity exceeds 0.10 D, the effect of expanding the surface area by each retaining groove g will decrease, and the heat dissipation of the sleeve 3 will be inhibited. Furthermore, when the groove radius C is less than 0.002D, molten metal enters each retaining groove g, and a gap is likely to be formed between the inner surface of the groove and the cylinder barrel 1° to 14°.On the other hand, when it exceeds 0.04D, the groove This is because as the pitch increases, the number of retaining grooves g decreases, and the effect of expanding the surface area by the retaining grooves g decreases, thereby impairing the heat dissipation of the sleeve 3.

Figures 5 to 9 show the cylinder block material S shown in Figure 4.
The apparatus is equipped with a mold M, and the mold M is provided with an upper mold 9 which can be raised and lowered, and which is disposed below the upper mold 9. In Figure 5, the first and second halves of the left and right halves are
Side type 101, 10! and bilateral 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, there is a mold clamping recess 1 that cooperates with the molds 10+ and 10g on both sides to define a cylinder barrel row molding cavity CI in which each cylinder barrel molding cavity is assembled.
2 is formed, and the mold clamping convex part 1 fits into the concave part 12.
3 is protrudingly provided on the upper surface of the both-side mold 101°10□.

7th. As shown in FIG. 8, the lower die 11 includes a sump 14 that receives molten aluminum alloy from a melting furnace (not shown), and a hot water cylinder 15 that communicates with the sump 14.
and a plunger 16 that is slid onto the hot water cylinder 15.
A pair of runners 17 are formed which branch into two from the sump portion 14 and extend in the longitudinal direction of the cylinder barrel row molding cavity CI and over approximately the same length. Further, the lower mold 11 has a molding block 18 projecting upward between the two runners 17, and the molding block 18 is connected to the mold 10 on both sides.
+ and 10□ to define a crankcase molding cavity C2. The upper end of the cavity C2 communicates with the cylinder barrel row molding cavity CI, and the lower ends on both sides communicate with both runners 17 via a plurality of weirs 19.

The molded block 18 includes four semicylindrical first molded parts 181 formed at predetermined intervals, and two first molded parts 181 located between adjacent first molded parts 188 and on the outermost side. and a convex-shaped second molded part 18 □ located on the outside of each first molded part 18 . is used to form a rotation space 20 (FIGS. 2 and 3) for the crank pin and crank arm,
The second molded part 18□ is the bearing holder 2 of the crank journal.
1 (Figures 2 and 3).

Each layer 19 has a respective second molded portion 18 . It is provided to correspond to the above, and the large capacity portion of the crankcase molding cavity C2 is filled with molten metal at an early stage.

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 addition, in the small cross-sectional area, a small amount of molten metal can be filled into the crankcase molding cavity C2 through the weir 19 at a high speed. The scene rises almost evenly over its entire length,
Therefore, the molten metal does not cause turbulent flow within the cavity C2, and gases such as air are prevented from being drawn into the molten metal, thereby making it possible to avoid the formation of cavities. Further, since the molten metal filling operation is performed efficiently, 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. A through hole 24 passing through the first molded part 181 is formed on both sides of the positioning protrusion 22, and a pair of temporary installation pins 25 are slid into the through hole 24, respectively.
These temporary installation pins 25 are used for temporary installation of the sand core for the water jacket. The lower ends of both plate installation pins 25 are fixed to a mounting plate 26 disposed below the forming block 18. The mounting plate 26 has two support rods 27.
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 touches the top of the first molded part 18+. 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.

In addition, the two first molded parts 181 located on both sides have the first molded part 18. A through hole 29 is formed through the through hole 29, and an operating bottle 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 29 protrudes into the recess 23, and when the mold is closed, it is pushed down by a collet mechanism described later, thereby moving both plate installation pins 25 into the first molding section 18.
1 It is designed to be pulled in from the top surface.

Positioning means 31 for actually installing sand cores are provided at two locations on the inner surfaces of the central portions of the first and second side molds 10+, to. Each positioning means 31 has a small diameter hole 31a.
and a stepped portion 31b formed on the outer periphery of the opening.

The mold clamping recess 12 of the upper mold 9 is formed with a plurality of overflow cavities C3 and communication zero molding cavities C4 that communicate with the cylinder barrel row molding cavities C1, and the upper mold 9 has each overflow cavity. Through holes 32 and 33 communicating with C1 and each communicating molding cavity C4 are formed, respectively.

Closing pins 34 , 35 are respectively inserted into the through holes 32 , 33 , and the upper ends of these closing pins 34 , 35 are fixed to a mounting plate 36 disposed above the upper die 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 of the closing pins 34 and 35 to close the overflow cavity C1 and the communication 0 molding cavity C4, but the diameter of the outside portion thereof is larger than the diameter of each of the closing pins 34 and 35. , thereby creating an air passage 37.3 between each closing pin 34.35 and each through hole 32.33.
8 is formed.

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 collet 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 actuating bottle 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 mold 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.
8. A protrusion 45a that can fit into the recess 23 on the top surface 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 slidably connected to the supporting rod 43 over substantially the entire length of the supporting rod 43, and the actuating rod 50 has a tapered shape that fits into the tapered hole 47 of the holding cylinder 46. portion 50a and its tapered portion 50a
It consists of a true inner part 50b that is connected to the upper mold 9, is slidably fitted into the through hole 42 of the upper mold 9, and protrudes from the upper mold 9. Tapered part 5
A plurality of pins 57 are protruded from 0b, and these pins 57 are inserted into vertically long pin holes 58 of the holding tube 46, thereby allowing the tapered portion 50a to move up and down while holding the holding tube 4.
6 is stopped.

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
+, SSZ with hollow piston rod 53. ．． Above 53□
The actuating rod 50 is raised and lowered by a hollow piston 52 while being brought into contact with the lower end surface. The collet mechanism 41 is connected to each cylinder barrel 1 of the cylinder block S.
There will be four machines corresponding to numbers 1 to 14.

10th. FIG. 11 shows a sand core 59 for a water jacket, and the sand core 59 has four cylindrical parts 60. 604, and the core body 61 has no overlapping peripheral walls, and the upper part of the core body 61 is formed to form a communicating lower which communicates the water jacket with the water jacket of the cylinder head. It is composed of a plurality of protrusions 62 protruding from the end face, and positioning protrusions 63 protruding from both outer surfaces of two cylindrical parts 60 □ and 603 located in the middle of the core body 61 . Each positioning protrusion 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.

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 the molds 101 and 101 on both sides are moved apart from each other to open the molds. In the collet mechanism 41, each hydraulic cylinder 51 is operated to lower the operating loft 50 by 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 actuated to raise the mounting plate 36, thereby moving each closing pin 34, 35 into the overflow cavity C3.
and a small diameter portion 3 communicating with the communication port molding cavity C4.
2a and 33a. Furthermore, the hot water cylinder 15
The plunger 16 inside is lowered.

A cast iron sleeve 3 having the configuration shown in FIG. 2A is attached to each holding cylinder 4.
6, and connect the upper end opening of the sleeve 3 to the convex portion 48 of the upper die 9.
The lower end surface of the sleeve 3 is fitted to the lower end surface of the convex portion 45a of the molten metal infiltration prevention plate 45, and the lower end opening of the sleeve 3 is closed by the molten metal infiltration prevention plate 45. Then, the hydraulic cylinder 51 of the collet mechanism 41 is operated, and the hollow piston 52 raises the operating rod 50. 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 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 core 59.

The double-sided molds 101.10□ are moved a predetermined distance in the direction in which they approach each other, and the small diameter hole 31 of each positioning means 31 is moved.
The small diameter portion 6 of each positioning protrusion 63 in the sand core 59 is shown in a.
3b, and the end surfaces of each large diameter portion 63a abut against the step portions 31b of each positioning means 31, thereby accurately positioning the sand core 59 and positioning the sand core 59 on both side walls 10. ．． 10 □ and perform the actual installation of the sand core 59.

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 infiltration prevention plate 45 is inserted into the first molded part 18. It fits into the recess 23 on the top surface. As a result, the molten metal intrusion prevention plate 45
Since the operating pin 30 is pushed down by the convex portion 45a of the first molded portion 18. Pull in from the top.

Further, the mold clamping recess 12 of the upper mold 9 is connected to the mold clamping recess 12 of the upper mold 9. .

The mold clamping is performed by fitting into the mold clamping convex portion 13 of 10z.

Molten metal made of aluminum alloy is supplied from the melting furnace to the sump 14 of the lower mold 11, and the plunger 16 is raised to allow the molten metal to flow from both runners 17 through the weir 19 and from the lower edge of the crankcase molding cavity C2 into the cavity. Fill C7 and cylinder barrel row molding cavity CI. Gas such as air in both cavities C1 and C2 is pushed up by the molten metal and passes through an air passage 37.3 that communicates with the overflow cavity C8 and the connecting mouth molding cavity C1.
8 and exits above the upper mold 9.

In this case, the retaining groove g of each sleeve 3 is formed in a sub-arc shape, so when the cylinder barrel row forming cavity C9 is filled with molten metal, the gas in the retaining groove g is pushed up by the molten metal, as shown by the arrow in FIG. 2A. As shown in e, it flows smoothly along the arcuate inner surface and is reliably discharged outside the groove. As a result, gas is not trapped in the retaining groove g.

Further, as described above, both runners 17 have a cross-sectional area that gradually decreases toward the runner light 17a.
Since it is formed in the shape of several steps ascending from the side, as the plunger 16 rises, the molten metal flows from both runners 17 through each layer 19 from the lower ends of both sides of the crankcase molding cavity C2 almost uniformly over the entire length of the cavity. You can push up inside C2 smoothly. Therefore, the molten metal does not cause turbulent flow within both cavities C+ and Cz, and gases such as air can be prevented from being drawn into the molten metal, thereby avoiding the formation of cavities.

When each overflow cavity C1 and each communication port molding cavity C4 are filled with molten metal, the hydraulic cylinder 39 on the upper die 9 is operated to lower the mounting plate 36, and the closing pin 34.35 closes both cavities C3. ,C4
The small diameter portions 32a and 33a that communicate with the are closed. .

In the pouring operation, the displacement of the plunger 16 and the pressure of the molten metal for filling the crankcase molding cavity Ct and the cylinder barrel row molding cavity C6 with molten metal are controlled as shown in FIG.

That is, the plunger 16 changes its moving speed to the first to third speeds V.
, ~■3. In this embodiment, the first speed V
, is 0.08 to 0.3 m/sec, 2nd speed ■2 is 0
．． 14 to 0.18 m/sec, and the third speed V is set to 0.04 to 0.08 m/sec to achieve a significant deceleration state, and this three-stage speed control prevents the molten metal from collapsing. A quiet molten metal flow is formed without involving gas such as air, and the molten metal is transferred to both cavities Ct.
, C+ can be filled efficiently.

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 substantially constant, and the second and third speeds V2. V3
Since the molten metal fills both cavities C1 and C2, the pressure P of the molten metal rises rapidly. 3rd plunger 16
After moving at speed V for a predetermined time, the filling pressure P of the molten metal is maintained at 150 to 400 k[/cd] 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/cd, 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.

In addition, since the sand core 59 is held in an accurate position by the two-sided molds to+ and toz through its respective positioning protrusions 63, when filling the cylinder barrel row molding cavity C1 with molten metal and the cavity C8. The sand core 59 will not float up when the molten metal inside is pressurized. Further, the end face of the large diameter portion 63a of each positioning protrusion 63 is connected to the stepped portion 31 of the positioning means 31 in the double-sided type 101.10□.
b, the pressure of the molten metal acting on the sand core 59 is applied to the both side molds 10. ．． 10□, thereby preventing deformation of the sand core 59 and providing a cylinder barrel row 4 with uniform wall thickness around each sleeve 3.

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 completely solidified, the hydraulic cylinder 51 of the collet 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, as shown in FIG. A cylinder block material Sm is obtained.

When the cylinder block material Sm is subjected to a grinding process to remove each protrusion 64 formed by the cooperation of each communication port forming cavity C4 and each protrusion 62 of the sand core 59, each communication lower is formed, and By removing the sand, a water jacket 6 is obtained. Furthermore, by rounding the inner peripheral surface of each sleeve 3 and performing other predetermined processing, the cylinder block S shown in FIGS. 1 to 3 is obtained. can get.

FIG. 13 shows the sleeve 3 in the cylinder block S.
This is a micrograph (100x magnification) showing the metallographic structure of the welded part between the sleeve 3 and the cylinder barrel 11.As is clear from this drawing, the adhesion between the sleeve 3 and the cylinder barrel II is good, and the welded part between the sleeve 3 and the cylinder barrel II is good. There are no minute gaps. This is due to the removal of the cast surface on the entire outer peripheral surface of the sleeve 3.

Furthermore, since each retaining groove g is formed by machining, its dimensional accuracy is good, and therefore the thickness of the sleeve 3 at the retaining groove g and the land portion l becomes uniform.

Note that when each of the retaining grooves g is formed using a mold, the depth of the groove varies by about 1.0 mm at most.

When an engine is assembled and operated using the cylinder block S, the amount of thermal expansion around the circumference of each sleeve 3 becomes approximately equal.

Note that the retaining groove g of each sleeve 3 is not limited to an annular shape, but may be spirally shaped. Further, the retaining groove g does not necessarily need to be provided over the entire length of the sleeve 3, but may be provided in a range from the end on the cylinder head side to a portion facing the oil ring of the piston at the bottom dead center.

C0 Effects of the Invention According to the present invention, since the casting surface of the entire outer circumferential surface of the sleeve is removed, the adhesion between the sleeve and the molten metal is improved, and no minute gaps are created between the sleeve and the cylinder barrel. The heat dissipation is performed uniformly around the circumference, and the surface area of the sleeve is expanded by the retaining groove, so together with the above-mentioned good adhesion, the heat dissipation efficiency of the sleeve is improved.

Furthermore, the thickness of the sleeve at the retaining groove and the land portion becomes uniform.

As a result, the amount of thermal expansion around the circumference of each sleeve during engine operation is approximately equal, and the generation of gaps between the piston ring and the sleeve is minimized, reducing problems such as an increase in blow pie gas and wasteful consumption of oil. It can be solved.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the Siamese type cylinder block according to the present invention, in which FIG. 1 is a perspective view seen from above, FIG. 2 is a sectional view taken along line nn in FIG. 1, and FIG. 2A is a Fig. 2 is a partially enlarged view, Fig. 3 is a perspective view seen from below, Fig. 4 is a perspective view of the Siamese type cylinder block material seen from above, and Fig. 5 is a vertical front view of the casting machine when the mold is opened. , 6th
The figure is a longitudinal sectional front view of the casting device when the mold is closed, FIG. 7 is a sectional view taken along the line nn of FIG. 1, FIG.
The figures are a cross-sectional view taken along the line nn in Figure 1, a perspective view of the sand core seen from above, Figure 11 a cross-sectional view taken along the line XI-XI in Figure 10, and Figure 12 the displacement of the plunger over time. and a graph showing the relationship between the pressure of the molten metal and time, and FIG. 13 is a micrograph showing the metal structure at the welded portion between the cylinder barrel and the sleeve. S... Cylinder block, g... Retaining groove, 11-
14...Cylinder barrel, 3...Sleeve Fig. 4 Fig. 3 Fig. 1 Fig. 12 Time (sec) Procedural Dispute Manual (Method) % Formula % 2. Name of the invention Siamese type cylinder block 3. Relationship with the case of the person making the amendment Patent applicant name (532) Honda Motor Co., Ltd. 4, agent address 4-5-5 Shinbashi, Minato-ku, Tokyo, date of amendment order: February 6, 1985 ( Shipping date: February 26, 1985)
Procedural amendment (indication of own ship January 13, 1986 incident Patent application No. 238099 issued in 1988 #404, type -8'/971-7...) Person making the amendment Relationship with the incident Patent applicant name (532) Honda Motor Co., Ltd. Agent 〒105 Subject of amendment Contents of amendment 1. The statement in the "Claims" column of the specification is corrected as follows. In the Siamese type cylinder block, each cylinder of an aluminum alloy Siamese cylinder barrel is surrounded by a cast iron sleeve. A Siamese-type cylinder block characterized in that annular or spiral retaining grooves are formed at a predetermined pitch along the circumferential direction over a predetermined length from an end on the cylinder head side on the outer peripheral surface. 2. 5. Line 6 of Specification No. 2 Due East is corrected as follows: [A cast iron sleeve is cast into each cylinder barrel of an aluminum alloy Siamese cylinder barrel formed by combining a plurality of cylinder barrels.” 3. In the specification, page 3, line 3, ``Inode''... is corrected to ``Inode, j...''. 4. In the specification, page 5, line 6. ~In the last line, the phrase "arranged in series" should be corrected as follows: "The cylinder block body 2 consists of an aluminum alloy cylinder block body 2 and a cast iron sleeve 3. The illustrated example includes a Siamese cylinder barrel 1 formed by combining four cylinder barrels 1+=1n, an outer wall 4 surrounding the Siamese cylinder barrel 1, and a crankcase 5 connected to their lower edges. Between the Siamese cylinder barrel 1 and the outer wall 4, there is a water jacket 6 that faces the entire circumference of the Siamese cylinder barrel 1.
is formed, and at the cylinder head side opening of the water jacket 6, each cylinder barrel l, ~ 14 and the outer wall portion 4 are partially connected by a plurality of reinforcing deck portions 8 arranged in the circumferential direction. The space between the reinforcing deck portions 8 functions as a lower communicating portion of the water jacket 6 to the cylinder head side. As a result, the cylinder block S is configured into a closed deck type. Sleeve 3 covers each cylinder barrel l, ~14
The sleeve 3 defines a cylinder bore 3a. ” 5, page 7, lines 9 to 1 of the specification
Correct the 4th line on page 0 as follows. 5 to 9 show a casting device for the cylinder block material Sm shown in FIG. A lower mold 11 is disposed below the mold and on which the first and second side molds 10..10, which are divided into left and right halves in FIG. 5 and FIG. A mold clamping recess 12 is formed on the lower surface of the upper mold 9 to define a first cavity C1 in order to mold the Siamese cylinder barrel l and the outer wall part 4 in cooperation with the two molds toe and tow. 7. As shown in FIG. ), a sump 14 for receiving molten metal made of an aluminum alloy, a hot water cylinder 15 communicating with the sump 14, and a plunger 16 slidably connected to the hot water cylinder 1.5.
Then, it branches into two branches from the water reservoir part 14 and becomes the first key + bit C7.
A pair of runners 17 are provided that extend in the longitudinal direction of the runner and for approximately the same length. In addition, the lower mold 11 has both runners 1
It has a molded block 18 projecting upward between 7 and 7,
The molding block 18 cooperates with the molds 101.10t on both sides to define a second cavity C2 in which the crankcase 5 is molded. The upper end of the cavity C8 is the first cavity C
1, and the lower ends on both sides have multiple weirs 1 in both runners 17.
It communicates via 9. The molding block 18 is located outside of four tall semi-cylindrical first molding parts 181 formed at predetermined intervals, between adjacent first molding parts IL and both outermost first molding parts 18t. 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), and the second forming part 188 is used to form the crank journal bearing holder 21.
(Figs. 2 and 3). Each base 19 is provided corresponding to each second molding section 18o, so that the large capacity portion of the second cavity C2 is quickly filled with molten metal. The bottom surface of the runner 17 is formed in several ascending steps from the sump portion 14 side so that the cross-sectional area of both runners 17 gradually decreases toward the sump portion 14 and above all toward the runner light 17a. Each rising portion 17C connected to each step portion 17b is formed diagonally so that the molten metal can be smoothly guided to each base 19. 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 addition, in the part with a small cross-sectional area, a small amount of molten metal can be filled into the second cavity Ct through the weir 19 at a high speed. The scene rises almost evenly, and therefore the molten metal flows into the second cavity C.
J 6, page 11, line 15 to line 9 of member 12 of the specification are corrected as follows. %6ai of the notation 30 protrudes into the recess 23, and is pushed down by a diameter expanding mechanism to be described later when the mold is closed, thereby causing the both plate installation pins 25 to be retracted from the first molding part 1B+ top surface. Core holders 31 for actually installing sand cores are provided at two locations in the center of the wall defining the second cavity C3 in the first and second side molds 10s and 10g. The core holder 31 has a holding hole 31a for positioning the sand core, and a holding surface 31b formed on the outer periphery of the opening for holding the sand core.
It becomes more. A plurality of third cavities C1 for overflow and a plurality of fourth cavities C4 for forming communication ports are opened in the mold clamping recess 12 of the upper mold 9, and each third cavity Cs is opened in the upper mold 9. and through holes 32 communicating with each fourth cavity C4. ” 7. Page 12 of the specification, lines 18-19, ``Over... Tee Cal...''... ``3rd
．． Corrected to 4th cavity Cs, Ca J... 8. Specification page 13, line 11, page 15, line 15, 1
Page 6, line 16, page 17, lines 12-13, page 23, line 7, "Collet" is corrected to "Enlarged diameter J." 9. In the specification, page 14, line 19, ``Tapered portion 50b)'' is corrected to ``Tapered portion 50a''. IO0 Specification No. 1...[To surround sleeve 3]...
...Corrected to "corresponding to cylinder barrels 11 to 14"... 11. Lines 8 to 11 of page 16 of the specification are corrected as follows. 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.In this case, Protrusion 62
Its dimensions are set so that it can be loosely inserted into the fourth cavity C4. ” 12. Specification page 17, lines 2 and 3, ``Overty C4J...''...
・[Corrected to 3rd and 4th cavities C, C4 J... 13. Lines 4 to 9 of page 18 of the specification are corrected as follows. the engagement hole 3 of each core receiver 31.
The sand core 59 is positioned by fitting the small diameter portion 63b of each skirting board 63 in the sand core 59 to 1a, and each large diameter portion 63a
The end faces of the sand cores 59 are abutted against the clamping surfaces 31b of each core holder 31, thereby accurately positioning the sand cores 59,
14. Lines 4 to 1θ of page 19 of the specification are corrected as follows. [From the lower edge of the second cavity C8 to the cavity C1
and fills the first cavity C1. Gas such as air in both cavities C+ and Cm is pushed up by the molten metal to the third and fourth cavities C,. The air passes through air passages 37 and 38 communicating with C4 to the upper part of the upper mold 9. J 15, page 19, line 18 to page 20, line 17 of the specification are revised as follows. "Also, as mentioned above, the cross-sectional area of both runners 17 is the same as the runner light 17a.
The bottom of the runner is gradually reduced towards the sump part 1.
Since it is formed in the shape of several steps upward from the 4th side, the molten metal flows from both runners 17 to each layer 19 as the plunger 16 rises.
Through this, the inside of the cavity C8 can be smoothly pushed up almost evenly from the lower ends of both sides of the second cavity C1 over its entire length. Therefore, the molten metal is in both cavities CI,
It is possible to prevent turbulence within a cm and prevent gases such as air from being drawn into the molten metal, thereby avoiding the formation of cavities. Each third. When the fourth cavity Cs, Ca is filled with molten metal, the hydraulic cylinder 39 on the upper mold 9 is operated to lower the mounting plate 36 and close the closing pin 34. 35 closes the small diameter portions 32a and 33a communicating with both cavities Cx and Ca. In the pouring operation, the second. First cavity C,,C
, plunger J16 for filling molten metal into , page 21, line 2 of the specification, ... r O. 3 J... and...rO.
Corrected to 12J... 17. - The detailed description page 22, line 9 to page 23, line 2 are corrected as follows. Note: ``In addition, the sand core 59 expands due to the molten metal, but the protrusions 62
is loosely inserted into the fourth cavity C4, so the sand core 5
The protrusion 62 follows the expansion of the protrusion 9, thereby preventing the protrusion 62 from breaking. Furthermore, since the sand core 59 is held in an accurate position by the molds 1G+ and 10* on both sides through its baseboards 63, when filling the first cavity C8 with molten metal and the cavity CI. The sand core 59 does not float up when pressurizing the molten metal. Furthermore, since the end surface of the large diameter portion 63a of each skirting board 63 abuts against the clamping surface 31b of the core receiver 31 in the double-sided molds 101, 101, the sand core 5
9 tends to swell, the deformation force is applied to each clamping surface 31b.
This prevents deformation of the sand core 59 and provides a Siamese cylinder barrel l with uniform wall thickness around each sleeve 3. 1B, page 23, lines 13 to 15 of the specification are corrected as follows. [Then, each fourth cavity C4 and each protrusion 62 of the sand core 59
When each protrusion 64 formed in cooperation with is removed,
A communicating lower is formed by the protrusion 62, and a reinforcing deck portion 8 is formed between adjacent communicating lowers. 19. The first line of page 26 of Book 11 of the Meiji era is corrected as follows. [Fig. 2A is a partially enlarged view of Fig. 2, Fig. 2B is a partially enlarged view of Fig. 2]
Figure 1b-nb line sectional view, Figure 3 is lower j20, drawings 1-
4th. Fifth. 7th. Figure 8 is corrected as shown in the attached sheet. 21, Figure 2B of the drawing is attached as attached. that's all

Claims (1)

[Claims] In a Siamese type cylinder block in which a plurality of cast iron sleeves are cast into a plurality of aluminum alloy cylinder barrels arranged in series, the outer peripheral surface of the sleeve has the casting surface removed over its entirety, and the outer peripheral surface 1. A Siamese-type cylinder block characterized in that annular or spiral retaining grooves are formed at a predetermined pitch along the circumferential direction over a predetermined length from an end on the cylinder head side.