JPH08189413A - Cylinder block - Google Patents

Abstract

PURPOSE: To manufacture a cylinder block for an engine of closed deck/wet liner type easily. CONSTITUTION: In a die-cast cylinder block main body 14, one or more cylindrical member is provided it plural they are arranged contiguously. An insert member 15 provided with a first projection part 18 whose top end is formed flatly on the upper surface of the main body 14 and a second projection part 19 whose top end is formed flatly on the side part of the main body 14, is inserted inside the main body 14. At this time, the top ends of the first and second projection parts 18, 19 are exposed. Holes 22, 23 for the communication of a water jacket and a cylinder block outer part with each other are provided on the first and second projection parts 18, 19, and the holes 22, 23 are connected to a cylinder head, a water pump, and the like directly without through the forming member of the main body 14. A black peel (a chill layer) is formed on a tightened surface of the insert member 15 and the main body 14. It is thus possible to prevent water and oil from leaking from a space formed between the main body 14 and the insert member 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder block of a die-cast closed deck type engine.

[0002]

2. Description of the Related Art Generally, in a cylinder block of an engine made of an aluminum alloy, a cylinder liner made of a thin wear resistant material is incorporated, and a cylinder bore into which a piston is fitted is formed in the cylinder liner.

In this type of cylinder block, for example,
An open deck type, such as a cylinder block 1 shown in FIG. 12, having a structure in which a water jacket 3 formed on an outer peripheral portion of a cylinder liner 2 for circulating cooling water is opened at a cylinder head mounting surface 4, As in the cylinder block 5 shown in FIG. 13, the water jacket 7 formed on the outer peripheral portion of the cylinder liner 6 is closed by the cylinder head mounting surface 8, and the cooling water passage 9 communicating with the water jacket 7 is connected to the cylinder head mounting surface 8. There is a closed deck type with a structure provided with.

The open deck type cylinder block 1 as shown in FIG. 12 can be easily formed by a die casting method when cast and formed from an aluminum alloy, but the cylinder head mounting surface 4 is open. ,
It has the drawbacks of low rigidity and easy generation of vibration and noise.

On the other hand, in the closed-deck type cylinder block as shown in FIG. 13, since the cylinder head mounting surface 8 is closed, the rigidity is high and vibration and noise are less likely to occur. The advantage is that Further, like the cylinder block 10 shown in FIG.
The closed deck wet liner type in which the water jacket 12 is formed on the outer peripheral portion of the cylinder liner 11 is excellent in cooling efficiency because the cooling water in the water jacket 12 directly contacts the cylinder liner 11. In addition,
14, those parts that are the same as those corresponding parts in FIG. 13 are designated by the same reference numerals.

By the way, the closed deck wet liner type cylinder block 10 is difficult to form by the die casting method because the water jacket 12 forms an undercut portion due to its structure, and in general, a collapsible core is used. Although it is molded by the gravity casting method or the low pressure casting method, there is a problem that the core is complicated to manufacture and take out after molding, and the productivity is low.

Therefore, various methods for manufacturing a closed deck wet liner type cylinder block by using a die casting method have been conventionally proposed in order to improve productivity. For example, a method of forming a water jacket using a split type movable core (Japanese Patent Publication No. 2-53623).
Japanese Patent Publication No. 2-53624), a method of forming a water jacket in the same manner as the open deck type and then closing a part of the opening of the cylinder head mounting surface (Japanese Patent Laid-Open No. Hei 1).
No. 100352, Japanese Unexamined Patent Publication No. 1-147145, Japanese Patent Publication No. 2-11735), and a method of casting a cylinder liner having a water jacket in advance (Japanese Unexamined Patent Publication No. 62-
No. 113845, Japanese Utility Model Laid-Open No. 5-78950),
Also, a cylinder liner having a flange portion on the outside of one end is press-fitted into the small diameter portion of the stepped bore formed in the cylinder block, and the large diameter portion of the stepped bore and the side wall and the flange portion of the cylinder liner are used for water. Method of forming a jacket (Japanese Patent Laid-Open No. 60-135650, JP-B-1-10)
No. 427) is proposed.

[0008]

However, the above-mentioned conventional method of manufacturing a cylinder block has the following problems. That is, in the method (1), the structure of the die becomes complicated, the die cost becomes high, and the die life is short. In the above method, the step of closing a part of the opening is complicated, and improvement in productivity cannot be expected so much. In the method (1), the cylinder liner has a complicated shape and is difficult to manufacture. Therefore, improvement in productivity cannot be expected so much. In this method, it is difficult to firmly connect the cylinder block main body and the cylinder liner, and the rigidity of the cylinder block decreases. in this way,
The manufacturing method of the cylinder block shown above to
It cannot be said that any of them have been sufficiently satisfactory.

A die casting method using a disintegrating core or a low melting point metal core has also been developed.
Since the core is used, take out the core after molding,
Cleaning and core recycling are required, and productivity and cost are not satisfactory.

In addition, a method of directly fitting the cylinder liner after forming the cooling water passage by machining without using a core or the like is conceivable, but has the following problems. A chill layer composed of a dense structure is formed on the surface layer of the cylinder block, which is a die-cast product, but defects such as shrinkage cavities, blowholes, and pinholes are likely to occur inside, so machining such as cutting is difficult If applied, these internal defects will be exposed and problems such as water leakage and oil leakage will occur.
In order to suppress this, the cutting surface may have to be subjected to a very expensive post-treatment such as resin impregnation when it is actually used, and this method is not usually used.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cylinder block of a closed deck wet liner type engine which can be easily manufactured by a die casting method, and its manufacture. The purpose is to provide a method.

[0012]

Means for Solving the Problems According to the present invention for solving the above problems, there is provided a first die block cylinder block body in which one or a plurality of cylindrical members are connected to each other and a top end thereof is flat. An insert member having a protruding portion and a second protruding portion having a flat tip on the side portion is cast by exposing the first and second protruding portion tips and the inner peripheral wall of the cylindrical member, and above the insert member. It is characterized in that a water jacket is formed by a cylinder liner that can be inserted from the inside and the inner peripheral wall.

Further, in the present invention, the first and second
It is possible to form a communication hole between the water jacket and the outside of the cylinder block in the protruding portion of.

[0014]

The insert member and the part outside the cylinder block are separated from each other by forming a protrusion on the insert member that is cast in the cylinder block body and exposing the protrusion on the surface of the casting surface of the cylinder block body. Direct contact without going through. Further, since the contact surface between the insert member and the die-cast cylinder block body is made of black skin (chill layer), there is no fear of water leakage, oil leakage or the like. Furthermore, a water jacket formed inside the insert member and a hole for communicating with the outside of the cylinder block are bored in the protrusion, and cooling water is caused to flow through the hole.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the accompanying drawings. In the figure, the same or corresponding parts as those of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

The cylinder block 13 according to the invention is shown in FIG.
The cylinder block body has a structure as shown in
This is a closed deck wet liner type cylinder block composed of 14, an insert member 15 and a cylinder liner 16. The cylinder block body 14 is made of aluminum die cast. As will be described later, the insert member 15 is formed by connecting a plurality of cylindrical members 17 to each other.
The protrusion 18 and the second protrusion 19 of the cylinder block body
It is exposed and cast on the surface of 14 casting surfaces. Cylindrical member 17
Has a space region 20 inside, and a water jacket 21 is formed by closing it with a cylinder liner 16.
Further, communication holes 22 and 23 are formed in the first protrusion 18 and the second protrusion 19 to communicate the water jacket 21 and the outside of the cylinder block 13. Further, it has a plurality of oil passages 26.

The insert member 15 will be described with reference to FIG. Insert member 15 in this embodiment
Is for multiple cylinders (three cylinders) and has a shape like a plurality of cylindrical members 17 connected to each other. By forming the inner peripheral wall 151 of the insert member 15 so as to have a diameter larger than the diameter of the openings 152 and 153, the space region 20 is formed inside the insert member 15. Further, on the upper surface of the insert member 15, a plurality of first protrusions 18 having flat ends are formed. In addition, a second protrusion with a flat tip is also provided on the side.
19 are formed. As will be described later, the first protrusions form a contact surface with a cylinder head (not shown), so that their heights are uniform. In addition, the second protrusion 19
Has a shape that is flush with the side surface of the cylinder block body 14 after being cast in the cylinder block body 14.

As shown in FIG. 3, for example, the insert member 15 has flange portions 154 and 155 inside the upper and lower end portions.
It can be manufactured by joining two members 15a having a shape in which a connecting body of cylindrical members is halved and integrating them as shown in FIG. The other of the two members 15a (not shown) has a second protrusion 19 as shown in FIG.

Further, the above-mentioned 2 which forms the insert member 15
If the two members 15a are formed by a die casting method using an aluminum alloy, the advantages of mass production can be exhibited, and since a hard and dense chill layer is formed on the casting surface, the pressure resistance and waterproofness of the water jacket are improved. Therefore, it is preferable.

Further, as a method of joining the two members 15a, for example, resistance welding such as projection welding, arc spot welding, TIG welding, MIG welding, welding by friction welding or the like, Aron ceramic (manufactured by Toagosei Chemical Industry Co., Ltd.) ) Adhesion using a heat-resistant inorganic adhesive, brazing, or forming a fitting shape (for example, a pin and a hole, a convex portion and a concave portion) on the contact surfaces of both, and joining them by fitting. Can be used.

Next, a method of manufacturing the cylinder block 13 using the die casting method will be described with reference to FIGS. By the way, FIGS. 4 to 8 each show a vertical cross section taken along the line AA in the manufacturing process of the cylinder block 13 of FIG.

First, as shown in FIG. 4, an insert member
The flanges 154 and 155 of the first block 18 are inserted into the insert 24a, which is a part of the mold (cavity type) 24 of the cylinder block body, and the first protrusion 18 formed on the upper surface of the insert member 15 is inserted.
Is brought into contact with the mold 24. Next, as shown in FIG. 5, the mold (core mold) 25 is clamped, and the columnar protrusion 25a (FIG. 4) is brought into contact with the lower end portion of the insert member 15. Then, between the insert member 15 and the insert 24a, a space area where molten metal does not enter
Twenty is formed. At this time, the first protrusion 18 and the second protrusion 19 (not shown) can be used for positioning inside the molds 24 and 25. When the molten metal is injected into the mold and solidified, the mold is removed to form a cylinder block (semi-finished product) 13 'in which the insert member 15 is wrapped around the cylinder bore of the cylinder block body 14 as shown in FIG. It At this time, the tip of the first protrusion 18, the tip of the second protrusion 19 (not shown) and the inner peripheral wall
151 is exposed.

Next, as shown in FIG. 7, by machining,
The first protrusion 18 and the second protrusion 19 of the insert member 15
(Not shown), communication holes 22 and 23 (see FIG. 1) communicating with the space region 20 are formed. Then, as shown in FIG. 8, the cylinder liner 16 is press-fitted from above the insert member 16 to press the insert member 15 and the cylinder liner.
A water jacket 21 is formed between the water jacket 21 and 16.

As described above, by implementing the present invention, the following operational effects can be obtained.
First, by thus fitting the insert 24a, which is a part of the mold, into the insert member 15 and casting the insert member, the undercut portion for forming the water jacket 21 is eliminated. A closed deck wet liner type cylinder block 13 made of an aluminum alloy can be manufactured by using the die casting method.

Further, since a hard and dense chill layer is formed on the casting surface of the cylinder block body 14 by die casting, the cylinder block body 14 and the insert are combined with the chill layer formed on the casting surface of the insert member 15. Water leakage and oil leakage with the member 15 are prevented. Moreover, the communication hole 22 that is a passage for the cooling water to enter and exit the water jacket 21
Reference numerals 18 and 23 are parts of the insert member 15 and are directly exposed to the casting surface of the cylinder block main body 14, respectively.
Also, the communication holes 22 and 23 can be directly connected to the cylinder head, the water pump and the like without being provided with another member forming the cylinder block main body 14 since they are formed in the second protrusion 19. . Therefore, even if the cooling water or the like penetrates into the insert member 15, the chill layer described above does not cause water leakage or oil leakage to the outside of the insert member 15.

By the way, a case where the communication hole is provided at a place other than the protrusion is shown in FIG. As shown in the drawing, when the communication hole 22 ′ is bored in a place other than the first protrusion 18, the inside of the cylinder block body 14 having a shrinkage cavity, a pinhole, etc. is not formed. The cross section S is exposed in the communication hole 22 '. Therefore, the cooling water may squeeze out from the internal cross section S as shown by the arrow W and may enter the oil passage 26. Therefore, in the present invention, the insert member 15 is formed with the first and second protrusions 18 and 19 to be exposed on the casting surface of the cylinder block body 14, and only the first and second protrusions 18 and 19 are formed. By forming the cooling water communication holes 22 and 23, troubles such as water leak and oil leak can be prevented.

As described above, the cylinder block 13 can be easily manufactured without using a complicated mold and a collapsible core, the productivity can be improved and the manufacturing cost can be reduced, and at the same time, the water can be reduced. It is possible to form a closed deck / wet liner type cylinder block that does not cause problems such as leakage or oil leakage.

As described above, in the first embodiment, a combination of the insert member and the half-die-cast member is used, but the cylinder block having the same effect can be formed by the following method. can do. A second embodiment of the present invention will be described below with reference to the accompanying drawings. Portions which are the same as or corresponding to those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

A single view of the insert member 27 used in the second embodiment is shown in FIG. At least the inner peripheral wall 271 of the insert member 27 is formed by integrally forming a plurality of cylindrical members 28 having a uniform diameter. The upper surface has a plurality of first protrusions 18 each having a flat tip and a uniform height, and the second protrusions 19 each having a flat tip are also formed on the side portions. Insert member 27
May be integrally formed by die casting,
Alternatively, the cylindrical members 28 may be individually formed by cutting and then integrated by welding or the like.

The insert member 27 is, as in the first embodiment, cast into the cylinder block body 14 and then machined to form the hollow region 20. The other configurations are the same as those in the first embodiment, and the effects are the same.

Furthermore, an insert member as shown in FIG.
It is also possible to use 29. The insert member 29 has a hollow region 30 which is closed in advance. The insert member 29 of this type is cast in the cylinder block body 14 as in the first embodiment, the communication holes 22 and 23 are formed in the first and second projections 18 and 19, and the inner peripheral wall 29 is formed.
By removing 1 by cutting and fitting the cylinder liner 16 in it, a closed deck wet liner type cylinder block free from water and oil leaks can be formed by the die casting method.

Although not shown in the drawings, when the present invention is applied to a single cylinder engine, the insert member 15 and the like have a first protrusion 18 on the upper surface of a single cylindrical member and a second protrusion 18 on the side. It is assumed that the one in which the protruding portion 19 is formed is used.

[0033]

Since the present invention is constructed as described above, the following effects can be obtained. In the die-cast cylinder block main body, one or a plurality of cylindrical members are connected to each other, and an insert member having a first projection portion having a flat tip on an upper surface and a second projection portion having a flat tip on a side surface is provided. First
The black skin (chill layer) is formed on the contact surface between the insert member and the die-cast cylinder block main body by exposing and casting the tip of the second protrusion and the inner peripheral wall of the cylindrical member. It is possible to prevent water leakage and oil leakage between the block body and the insert member.

The communication holes, which are passages for the cooling water flowing in the water jacket, are a part of the insert member, and the first and second protrusions directly exposed to the casting surface of the cylinder block body. The communication hole can be directly connected to the cylinder head, the water pump, etc. without using the forming member of the cylinder block body. Therefore, even if cooling water or the like penetrates into the insert member, the chill layer does not cause water leakage or oil leakage to the outside of the insert member. Therefore, there is no need to perform surface treatment such as resin impregnation,
The factor of cost increase can be reduced.

A water jacket can be formed by closing the space area formed by the inner peripheral wall of the insert member cast in the cylinder block body with a cylinder liner that can be inserted from above the insert member. Therefore, a closed deck wet liner type cylinder block made of an aluminum alloy can be manufactured at low cost by using the die casting method.

[Brief description of drawings]

FIG. 1 is a schematic view of a cylinder block of an engine showing a first embodiment of the present invention.

FIG. 2 is a unitary view of an insert member cast in a cylinder block of the engine showing the first embodiment of the present invention.

FIG. 3 is a schematic view showing a member forming the insert member of FIG.

FIG. 4 is a schematic diagram showing a first stage of a manufacturing process of a cylinder block showing an embodiment of the present invention.

FIG. 5 is a schematic diagram showing a second stage of the manufacturing process of the cylinder block.

FIG. 6 is a schematic diagram showing a third stage of the manufacturing process of the cylinder block.

FIG. 7 is a schematic diagram showing a fourth stage of the manufacturing process of the cylinder block.

FIG. 8 is a schematic diagram showing a final stage of a manufacturing process of a cylinder block.

FIG. 9 is a schematic diagram showing a problem when a communication hole is formed in a portion other than a protrusion.

FIG. 10 is a single view of an insert member used in the second embodiment of the present invention.

FIG. 11 is a unitary view of an insert member used in another embodiment of the present invention.

FIG. 12 is a schematic view showing a conventional open deck type cylinder block.

FIG. 13 is a schematic view showing a conventional closed deck cylinder block.

FIG. 14 is a schematic view showing a conventional closed deck wet liner type cylinder block.

[Explanation of symbols]

 13 Cylinder block 14 Cylinder block body 15 Insert member 151 Inner peripheral wall 16 Cylinder liner 17 Cylindrical member 18 First protrusion 19 Second protrusion 21 Water jacket 22 Communication hole 23 Communication hole

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F02F 1/10 D 1/16 B

Claims (2)

[Claims] 1. A die-cast cylinder block main body has one or a plurality of cylindrical members connected to each other, and has a first protrusion having a flat tip on its upper surface and a second protrusion having a flat tip on its side. The insert member is cast-in by exposing the tips of the first and second projections and the inner peripheral wall of the cylindrical member, and a water jacket is formed by the cylinder liner insertable from above the insert member and the inner peripheral wall. A cylinder block for an engine, which is characterized in that 2. The cylinder block for an engine according to claim 1, wherein the first and second protrusions are provided with a communication hole between the water jacket and the outside of the cylinder block.