JP4058382B2 - Manufacturing method of closed deck cylinder block - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method of a closed deck type cylinder block in which a gasket surface side end portion of a water jacket portion is closed.
[0002]
[Prior art]
One type of cylinder block that constitutes an internal combustion engine such as an automobile is a closed deck cylinder block 3 in which the gasket surface 2 side of the water jacket portion 1 is closed as shown in FIG. If the thickness of the block main body 4 is the same, the closed deck cylinder block 3 has an advantage that the rigidity is higher than that of the open deck cylinder block in which the gasket surface side of the water jacket portion is open.
[0003]
In the case of the closed deck type cylinder block 3, the water jacket portion 1 is formed by gravity casting (GDC) or low pressure casting (LPDC) using a core that can be easily collapsed, a so-called collapsible core. .
[0004]
On the other hand, in an internal combustion engine, a piston (not shown) reciprocates inside the bore hole 5. For this reason, a cylinder sleeve 6 made of a material having excellent wear resistance, such as a so-called FC sleeve or MMC sleeve, is inserted into the bore hole 5, and the side peripheral wall portion of the piston is slid on the side peripheral wall portion of the cylinder sleeve 6. I try to contact them. As another material excellent in wear resistance, so-called high silicon-based aluminum is exemplified.
[0005]
When manufacturing such a closed deck type cylinder block 3, first, a collapsible core, a cylinder sleeve 6 and the like are arranged in a cavity formed by a casting mold, and in this state, molten metal is poured into the cavity. Then, the collapsible core, the cylinder sleeve 6 and the like are surrounded by the molten metal.
[0006]
Next, the block main body 4 is provided by cooling and solidifying the molten metal. Along with this cooling and solidification, the cylinder sleeve 6 is cast.
[0007]
Thereafter, the collapsible core is collapsed. The hollow portion obtained by this collapse becomes the water jacket portion 1. That is, in this case, the water jacket portion 1 is provided on the block body 4.
[0008]
By the way, in recent years, in order to prevent global warming, it is desired to improve the fuel efficiency of automobiles and the like from the viewpoint of energy saving. As a countermeasure, it has been proposed to reduce the weight of an automobile, which is the final product, by reducing the weight of an internal combustion engine or the like.
[0009]
From this point of view, friction stir welding (see, for example, Patent Documents 1 and 2) has attracted attention. According to the friction stir welding, for example, when the block main body 4 made of aluminum and the cylinder sleeve 6 made of high silicon-based aluminum are joined, it can be easily joined even if the objects to be joined are different metals. Because.
[0010]
That is, for example, a thin block body 4 is manufactured by high pressure casting (HPDC), and a cylinder sleeve 6 is joined to the block body 4, whereby a small and lightweight closed deck cylinder block 3 can be obtained. it is conceivable that. In addition, HPDC does not require the use of a collapsible core, so there is an advantage that the cost can be reduced.
[0011]
The friction stir welding is generally performed as follows. First, the friction stir welding tool that rotates is moved to the abutting portion to be joined after being buried in the workpiece, and is further displaced along the abutting portion. Along with this displacement, the meat of the butted portion is softened by frictional heat and stirred by the friction stir welding tool. As a result, the butt portion is solid-phase bonded. Thereafter, the friction stir welding tool is detached from the workpiece.
[0012]
[Patent Document 1]
JP 2000-176658 A (FIG. 1)
[Patent Document 2]
JP 2000-42759 A (FIG. 1)
[0013]
[Problems to be solved by the invention]
In order to further reduce the size and weight of the cylinder block, for example, it is conceived that a gap is formed between the block main body and the cylinder sleeve, and the gap is used as a water jacket portion. This is because, unlike the case where the block body 4 is provided with a hollow portion and the hollow portion is used as the water jacket portion 1 as described above, a portion for casting the cylinder sleeve into the block body is not necessary.
[0014]
However, as understood from the above, in the friction stir welding, the butt portion is joined. For this reason, when joining a block main body and a cylinder sleeve, it is necessary to contact | abut a block main body and a cylinder sleeve, and to provide a butt | matching part. In other words, when the block main body and the cylinder sleeve are to be joined by friction stir welding, it is necessary to bring the block main body and the cylinder sleeve into close contact with each other, so that it is difficult to provide a water jacket portion therebetween.
[0015]
That is, when a water jacket portion is provided between the block body and the cylinder sleeve in order to reduce the size and weight of the closed deck type cylinder block, there is a problem that it is extremely difficult to perform the friction stir welding.
[0016]
The present invention has been made to solve the above-described problems, and provides a closed deck cylinder block manufacturing method capable of obtaining a closed deck cylinder block having a thin wall thickness and excellent rigidity at a low manufacturing cost. The purpose is to provide.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a closed deck type cylinder in which a water jacket portion is formed in a gap between a block body and a cylinder sleeve, and a gasket surface side end portion of the water jacket portion is closed. A block manufacturing method comprising:
A step of manufacturing a block body provided with a stepped portion recessed in a diameter direction and a hole portion having a placement portion for placing one end face of the cylinder sleeve; and
The cylinder sleeve is inserted into the hole, and one end surface of the cylinder sleeve is placed on the mounting portion, and the water jacket portion is formed between the outer peripheral wall portion of the cylinder sleeve and the step portion. Process,
In a friction stir welding tool comprising a first rotating body and a second rotating body that are substantially orthogonal to each other and rotatable independently of each other, the axial direction of the cylinder sleeve and the axial direction of the first rotating body are parallel to each other. After being inserted into the cylinder sleeve so that the first rotating body is rotated along the circumferential direction of the cylinder sleeve, the cylinder sleeve and the Obtaining a cylinder block by friction stir welding the cylinder sleeve and the inner peripheral wall portion of the hole portion by plastically flowing the meat of the inner peripheral wall portion of the hole portion;
It is characterized by having.
[0018]
That is, in the present invention, a step portion having a concentrically increased diameter is provided in the hole portion into which the cylinder sleeve is inserted, and a gap formed between the step portion and the cylinder sleeve is used as a water jacket portion. Yes. For this reason, since it is not necessary to provide a hollow part in the block main body like the cylinder block according to the prior art and to use the hollow part as a water jacket part, a part for casting the cylinder sleeve into the block main body is not necessary.
[0019]
In addition, in this case, the amount of machining of the cylinder sleeve and the block body is significantly reduced. As a result, the material cost of the closed deck cylinder block, and hence the manufacturing cost, can be reduced.
[0020]
And in this invention, it is not necessary to provide the hollow part used as a water jacket part in a block main body. Therefore, it is possible to obtain a closed deck cylinder block that is thin and lightweight.
[0021]
Furthermore, since the block main body and the cylinder sleeve are joined by friction stir welding, even when both are made of different metal materials, they can be firmly joined. As a result, the obtained closed deck type cylinder block is excellent in strength and rigidity.
[0022]
In any case, it is preferable that the gasket sleeve side end face of the cylinder sleeve inserted into the hole and the gasket face of the block main body be joined by friction stir welding. As a result, the bonding strength between the block body and the cylinder sleeve is improved, so that the strength and rigidity of the closed deck cylinder block can be further improved.
[0023]
When the closed deck type cylinder block is of a multi-cylinder type, a flat surface is provided on the outer peripheral wall of the cylinder sleeve so that adjacent cylinder sleeves in the hole are brought into contact with each other via the flat surface. It is preferable. Thereby, since the space | interval between adjacent cylinder sleeves becomes small, it can obtain a closed deck cylinder block with a thinner thickness and light weight.
[0024]
In this case, you may make it provide the recessed part which becomes hollow in the diameter direction of a cylinder sleeve and functions as a water jacket part. Thus, the cooling efficiency of the closed deck cylinder block can be improved without increasing the interval between adjacent cylinder sleeves, in other words, without increasing the wall thickness.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a method for manufacturing a closed deck type cylinder block according to the present invention will be described in detail with reference to the accompanying drawings.
[0026]
First, the block main body 10 shown in FIG.
[0027]
As can be seen from FIG. 1, the block body 10 is provided with a hole 14 for inserting the cylinder sleeves 12 a to 12 d shown in FIG. 2. A portion 16 is provided. Further, the hole portion 14 is provided with a step portion 18 that is recessed in the diameter direction. That is, the hole part 14 and the step part 18 are provided concentrically. In FIG. 1, reference numerals 20 and 22 denote a journal portion and a gasket surface, respectively.
[0028]
The block body 10 can be manufactured by, for example, HPDC using a molten aluminum. At this time, it is not necessary to dispose the collapsible core in the cavity of the casting mold.
[0029]
The step portion 18 may be provided simultaneously with the hole portion 14 when performing HPDC, or after only the hole portion 14 is formed by HPDC, a part of the inner peripheral wall portion of the hole portion 14 is notched. You may make it provide by.
[0030]
On the other hand, cylinder sleeves 12a to 12d shown in FIG. 2 are produced. Among these, the cylinder sleeves 12a and 12d are provided with a cylindrical body by, for example, performing a known molding method such as extrusion molding or casting on a workpiece made of high silicon-based aluminum, and then the side of the cylindrical body It is manufactured by notching a part of the peripheral wall portion and providing flat surfaces 24a and 24d, respectively.
[0031]
The flat surfaces 24a and 24d are provided with recesses 26a and 26d that are recessed in the diameter direction of the cylinder sleeves 12a and 12d.
[0032]
The remaining cylinder sleeves 12b and 12c are provided with flat surfaces 24b and 24c similar to the flat surfaces 24a and 24d of the cylinder sleeves 12a and 12d, and then further flattened at a position 180 degrees around the flat surfaces 24b and 24c. It is produced by providing 28b and 28c. Of course, these flat surfaces 24b, 24c, 28b, 28c are also provided with recesses 26b, 26c, 30b, 30c, respectively.
[0033]
Next, as shown in FIG. 3, these cylinder sleeves 12 a to 12 d are inserted into the holes 14 of the block body 10. At this time, the lower end portion of the inserted cylinder sleeve 12a~12d is Ru placed on the stepped portion provided on the lower side of the continuous annular step 16 (mounting portion). Thereby , the cylinder sleeves 12a to 12d are firmly supported from below.
[0034]
The outer peripheral wall portion at each end in the longitudinal direction of the cylinder sleeves 12 a to 12 d inserted into the hole portion 14 abuts on the inner peripheral wall portion of the hole portion 14. Further, the flat surface 28b of the cylinder sleeve 12b contacts the flat surface 24a of the cylinder sleeve 12a. Similarly, the flat surface 24c of the cylinder sleeve 12c contacts the flat surface 24b of the cylinder sleeve 12b, and the flat surface 24d of the cylinder sleeve 12d contacts the flat surface 24c of the cylinder sleeve 12c.
[0035]
Further, the outer peripheral wall portion of the middle portion of the cylinder sleeves 12a and 12d and the step portion 18 are separated from each other, and the recesses 26a and 30b and 26b are provided between the adjacent cylinder sleeves 12a and 12b, 12b and 12c, and 12c and 12d. By separating 30c, 26c, and 26d, a gap communicating with each other is formed. This gap becomes the water jacket portion 32.
[0036]
Thus, in the present embodiment, the water jacket portion 32 is formed as the cylinder sleeves 12 a to 12 d are inserted into the hole portion 14.
[0037]
Next, the block main body 10 and the cylinder sleeves 12a to 12d inserted into the holes 14 are friction stir welded to join and integrate the members 10 and 12a to 12d. That is, first, the inner peripheral wall portion of the hole portion 14 and the outer peripheral wall portions of the cylinder sleeves 12a to 12d are friction stir welded.
[0038]
As shown in FIG. 4, the friction stir welding tool 40 includes a first rotating body 42 and a first rotating body 42 provided on a side peripheral wall portion of the first rotating body 42 and rotatable independently of the first rotating body 42. A two-rotor 44 and a probe 46 having a smaller diameter than the second rotor 44 and having a conical tip are provided. The friction stir welding tool 40 thus configured is inserted into the cylinder sleeve 30a, and the probe 46 is brought into contact with the inner peripheral wall portion of the cylinder sleeve 12a. At this time, the probe 46 is positioned below the water jacket portion 32.
[0039]
When the second rotating body 44 is urged to rotate in this state, frictional heat is generated as the probe 46 comes into sliding contact with the inner peripheral wall portion of the cylinder sleeve 12a, and the contact portion of the probe 46 on the inner peripheral wall portion is softened. To do. As a result, the tip of the probe 46 is buried.
[0040]
The buried probe 46 finally passes through the cylinder sleeve 12a and reaches the inner peripheral wall portion of the hole portion 14, and accordingly, the outer peripheral wall portion of the cylinder sleeve 12a and the inner peripheral wall portion of the hole portion 14 rub against each other. Softens by heat.
[0041]
Next, when the first rotating body 42 is urged to rotate in the direction of arrow B, the buried probe 46 is displaced along the circumferential direction of the cylinder sleeve 12a. As the probe 46 is displaced in this manner, the softened meat is agitated and plastically flowed by the probe 46, and then solid-phase bonded as the probe 46 is separated. By repeating this phenomenon sequentially, the outer peripheral wall portion of the cylinder sleeve 12a and the inner peripheral wall portion of the hole 14 are joined and integrated. At the same time, the flat surface 24a of the cylinder sleeve 12a and the flat surface 28b of the cylinder sleeve 12b are joined and integrated.
[0042]
At this time, as shown in FIG. 3, the cylinder sleeves 12 a and 12 b are firmly supported by being mounted on the mounting portion provided below the continuous annular step portion 16. For this reason, friction stir welding can be easily performed.
[0043]
Thereafter, if the same operation is performed on the remaining cylinder sleeves 12b to 12d, the adjacent cylinder sleeves 12a and 12b, 12b and 12c, 12c and 12d are joined together, and the inner peripheral wall of the hole 14 in the block body 10 A four-cylinder closed deck type cylinder block 50 is obtained in which the portion and the outer peripheral wall portions of the cylinder sleeves 12a to 12d are joined (see FIG. 3). As can be understood from FIG. 3, the closed deck type cylinder block 50 is closed on the gasket surface 22 side in the water jacket portion 32.
[0044]
Further, the end faces on the gasket surface 22 side of the cylinder sleeves 12a to 12d and the gasket surface 22 may be joined and integrated by friction stir welding. At this time, as shown in FIG. 5, a friction stir welding tool 54 having a rotating body 51 and a probe 52 may be used.
[0045]
In this case, as indicated by an arrow A in FIG. 6, the probe 52 is displaced along the abutting portion between the outer peripheral edge portion of the cylinder sleeves 12 a to 12 d on the gasket surface 22 side end surface and the block body 10. Along with this displacement, the meat of the outer peripheral edge and the meat of the gasket surface 22 in the block body 10 are softened by frictional heat and are agitated by the probe 52. As a result, these meats are solid-phase bonded.
[0046]
Next, the end faces of the adjacent cylinder sleeves 12a and 12b, 12b and 12c, and 12c and 12d on the gasket surface 22 side are subjected to friction stir welding. At this time, the probe 52 may be displaced along the arrows B to D in FIG.
[0047]
Thus, on the gasket surface 22 side, the rigidity of the cylinder block 50 can be further improved by joining and integrating the block body 10 and the cylinder sleeves 12a to 12d and the adjacent cylinder sleeves. Note that there is no clear boundary line between the members 10 and 12a to 12d after being joined to each other.
[0048]
Since the block main body 10 constituting the closed deck cylinder block 50 is cast and molded by HPDC, the wall thickness is thin. Moreover, as can be understood from FIG. 3, the gap between the step portion 18 of the block body 10 and the cylinder sleeves 12a to 12d becomes the water jacket portion 32, so that a general closed deck cylinder block 3 (FIG. 8) is formed. It is not necessary to provide the water jacket portion 1 as a hollow portion of the block body 4 as shown in FIG. Therefore, since the thickness of the block main body 10 can be reduced, the volume of the closed deck cylinder block 50 can be reduced. In other words, the closed deck cylinder block 50 can be reduced in size and weight.
[0049]
In HPDC, it is not necessary to use a collapsible core. In other words, there is no need to prepare a collapsible core. For this reason, the cost required for the collapsible core becomes unnecessary, and the manufacturing cost of the closed deck cylinder block 50 can be reduced.
[0050]
And according to this Embodiment, only a part of outer peripheral wall part of cylinder sleeve 12a-12d is cut and removed, and it is not necessary to cut and remove block body 10 and cylinder sleeves 12a-12d greatly. That is, the amount of waste material is extremely small. In addition, in this case, the block body 10 is made of inexpensive aluminum. For the above reasons, the material cost of the closed deck cylinder block 50, and hence the manufacturing cost, can be further reduced.
[0051]
In addition, since the friction stir welding is employed, in the closed deck cylinder block 50, the block main body 10 (aluminum) and the cylinder sleeves 12a to 12d (high silicon-based aluminum) which are different from each other are firmly joined. Has been. For this reason, the closed deck cylinder block 50 exhibits high strength and rigidity.
[0052]
Furthermore, in this closed deck type cylinder block 50, since the cylinder sleeves 1a to 12d made of high silicon aluminum having excellent wear resistance are used, sufficient durability is ensured.
[0053]
In the above-described embodiment, the water jacket portion 32 is also provided between the adjacent cylinder sleeves. However, this is not always necessary, and the block body 10 and each of the cylinder sleeves 12a to 12d are not necessarily required. You may make it provide the water jacket part 32 only in between.
[0054]
Alternatively, the cylinder sleeves 12a to 12d may be joined in advance by welding or the like to form a cylinder sleeve coupling body and then inserted into the hole portion 14.
[0055]
The cylinder sleeves 12a to 12d are not particularly limited to those made of high silicon-based aluminum. For example, it may be made of another aluminum alloy or may be made of aluminum. As another suitable example, an aluminum quenching powder sleeve obtained by sintering a rapidly quenched aluminum powder, an MMC sleeve, and the like can be given.
[0056]
On the other hand, the block main body 10 is not limited to the one made of aluminum, and may be made of another material such as magnesium or a magnesium alloy.
[0057]
【The invention's effect】
As described above, according to the method for manufacturing a closed deck cylinder block according to the present invention, a step portion having a concentrically increased diameter is provided in the hole portion into which the cylinder sleeve is inserted, and the step portion and the cylinder sleeve are provided. A gap formed therebetween is used as a water jacket portion. For this reason, since the amount of the waste material is remarkably reduced, an effect that the material cost of the closed deck type cylinder block and consequently the manufacturing cost can be reduced is achieved.
[0058]
In addition, in this case, since it is not necessary to provide a hollow portion that becomes a water jacket portion in the block body, a closed deck cylinder block that is thin and lightweight can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic perspective partial cutaway view of a block body constituting a closed deck type cylinder block.
FIG. 2 is a schematic overall perspective view of a cylinder sleeve constituting a closed deck type cylinder block.
FIG. 3 is a schematic vertical cross-sectional view of a main part showing a state in which a cylinder sleeve is inserted into a hole of a block main body.
FIG. 4 is a schematic vertical sectional view of a main part showing a state where a probe of a friction stir welding tool is buried in a cylinder sleeve.
FIG. 5 is a schematic vertical sectional view of a main part showing a state where a gasket surface of a block body and a gasket surface side end portion of a cylinder sleeve are friction stir welded.
6 is an explanatory plan view from the gasket surface side for explaining the displacement direction of the friction stir welding tool when the end surface of the cylinder sleeve on the gasket surface side is bonded to the block body (gasket surface). FIG.
FIG. 7 is an explanatory plan view from the gasket surface side for explaining the displacement direction of the friction stir welding tool when the end surfaces on the gasket surface side of the cylinder sleeve are joined together.
FIG. 8 is a schematic vertical sectional view of a main part of a general closed deck type cylinder block.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 32 ... Water jacket part 2, 22 ... Gasket surface 3, 50 ... Closed deck type cylinder block 4, 10 ... Block main body 5 ... Bore hole 6, 12a-12d ... Cylinder sleeve 14 ... Hole part 16 ... Continuous annular step part 18 ... Steps 24a-24d, 28b, 28c ... Flat surfaces 26a-26d, 30b, 30c ... Recess 40, 54 ... Friction stir welding tool 46, 52 ... Probe

Claims (4)

A manufacturing method of a closed deck type cylinder block in which a water jacket portion is formed in a gap between a block main body and a cylinder sleeve, and a gasket surface side end portion of the water jacket portion is closed,
A step of manufacturing a block body provided with a stepped portion recessed in a diameter direction and a hole portion having a placement portion for placing one end face of the cylinder sleeve; and
The cylinder sleeve is inserted into the hole, and one end surface of the cylinder sleeve is placed on the mounting portion, and the water jacket portion is formed between the outer peripheral wall portion of the cylinder sleeve and the step portion. Process,
In a friction stir welding tool comprising a first rotating body and a second rotating body that are substantially orthogonal to each other and rotatable independently of each other, the axial direction of the cylinder sleeve and the axial direction of the first rotating body are parallel to each other. After being inserted into the cylinder sleeve so that the first rotating body is rotated along the circumferential direction of the cylinder sleeve, the cylinder sleeve and the Obtaining a cylinder block by friction stir welding the cylinder sleeve and the inner peripheral wall portion of the hole portion by plastically flowing the meat of the inner peripheral wall portion of the hole portion;
A closed deck cylinder block manufacturing method characterized by comprising:   2. The manufacturing method according to claim 1, further comprising a step of friction stir welding the gasket surface side end surface of the cylinder sleeve inserted into the hole and the gasket surface of the block body. Mold cylinder block manufacturing method.   3. The manufacturing method according to claim 1, wherein a flat surface is provided on an outer peripheral wall portion of the cylinder sleeve, and the cylinder sleeves adjacent in the hole portion are brought into contact with each other via the flat surface. Manufacturing method of closed deck type cylinder block.   4. The manufacturing method of a closed deck type cylinder block according to claim 3, wherein a recess functioning as a water jacket portion is provided in the flat surface so as to be recessed in a diameter direction of the cylinder sleeve.

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