JP3829571B2 - Engine cylinder block structure and engine cylinder block plating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine structure, and more particularly to an engine cylinder block structure in which a piston sliding surface of a cylinder is plated and a method for plating an engine cylinder block .
[0002]
[Prior art]
2. Description of the Related Art Conventionally, the configuration of a motorcycle engine is such that a cylinder block and a crankcase are configured separately, and a sleeve for sliding a piston is press-fitted or cast into the cylinder block. It is.
The cylinder block is also known in which the inner surface of the cylinder bore, that is, the piston sliding surface is subjected to SCEM plating. When the piston sliding surface is plated, the entire cylinder block is immersed in a plating solution, and an electrode is inserted into the center of the cylinder portion to perform plating. After completion, the cylinder block is lifted from the plating tank to drain the plating solution, and the operation is completed.
[0003]
In recent years, in order to improve engine productivity, reduction in the number of parts, reduction in the number of attachment (tightening), reduction in size and weight, cost reduction, and the like have been demanded.
When the cylinder block and crankcase are configured separately, as in the past, positional accuracy for assembling both parts is required, and processing accuracy is required to ensure sealing performance, and many processing steps are required. In addition, there is a problem that assembly man-hours are required.
[0004]
Therefore, in order to solve the above problems and improve productivity, there has been proposed a structure in which a cylinder block and a crank housing are integrated as disclosed in JP-A-11-182322.
According to Japanese Patent Application Laid-Open No. 11-182322, the cylinder block is formed integrally with the cylinder portion having the piston sliding surface and the upper half of the crankcase, and a plating film is formed only on the piston sliding surface. Is. According to this, it is possible to reduce the number of parts and the number of manufacturing steps.
[0005]
[Problems to be solved by the invention]
However, when plating is performed on the piston sliding surface, the cylinder block is conventionally configured as a single unit, so the shape is not complicated, and the plating liquid can be easily drained. According to the problem, part of the cylinder block and crankcase are integrally formed, so the parts become large, complicated and heavy, and it is difficult to perform plating processing, especially plating solution draining. Has occurred.
In addition, if the drainage is poor, there is a problem that the plating solution is unnecessarily taken up from the plating tank and the cost increases.
[0006]
The present invention has been made in view of the above-described conventional problems, and with a simple configuration, improves the drainage of the plating solution in the plating process, reduces the amount of the plating solution taken out, and improves workability. An object of the present invention is to provide an improved engine cylinder block structure and an engine cylinder block plating method .
[0007]
[Means for Solving the Problems]
The present invention includes a plurality of cylinder portion having a piston sliding surface, in an engine provided with a first water jacket for cooling, which are formed over the top on the outer periphery of the cylinder portion from substantially the center of the cylinder longitudinal there are, on the mating surface of the cylinder head, said first water jacket and an engine and mounting screw hole for mounting the opening portion of the cylinder head is formed for communicating the second water jacket of the cylinder head in the cylinder block, inside the cylinder block, the communicating said first to said cylinder arrangement direction the water jacket downwardly extend the crossover passage in the width direction of the cylinder block the passage to the crank chamber 1 to form a passage in body traveling direction before between cylinder portion adjacent a first water jacket Between the adjacent cylinder parts, the jacket part on the rear side of the part formed separately is biased forward of the jacket part formed inside the rear wall behind the substantially central part in the circumferential direction of the cylinder part. the cylinder block of the engine, characterized in that the formation of the second passage communicating with said communication hole and said mounting screw holes by placing the mounting screw holes on the rear side of the jacket portion of the rear structure It is.
[0008]
In the present invention, it is preferable that the second passage penetrates a pilot hole of a mounting screw hole of the cylinder head through the communication hole and communicates the mounting screw hole and the communication hole.
[0009]
Further, the present invention is an engine comprising a plurality of cylinder parts having piston sliding surfaces, and a first water jacket for cooling on the outer periphery of the cylinder part from substantially the center to the upper part in the longitudinal direction of the cylinder. And an opening for communicating the first water jacket and the second water jacket on the cylinder head side and a mounting screw hole for mounting the cylinder head on the mating surface with the cylinder head. In the plating method of forming a plating film on the piston sliding surface, a communication hole extends in the width direction of the cylinder block in the cylinder arrangement direction inside the cylinder block of the engine, and the communication hole and the attachment forming a passage communicating with the screw holes, adhesion bonding the mating surfaces of the two cylinder head of the cylinder block The performed plating the piston sliding surface, after plating, in a state of overlapping the two cylinder blocks in the vertical direction, the plating liquid in the cylinder block located on the upper side, the cylinder block located on the lower side Te The engine cylinder block plating method is characterized in that it is discharged through a passage communicating the communication hole and the mounting screw hole .
[0010]
According to the present invention, inside the cylinder block, communicating the first was in the water jacket downwardly by extending the communication holes over the width direction of the cylinder block to the cylinder arrangement direction the passage into the crank chamber By forming the first passage, the weight of the cylinder block can be reduced, and the pressure fluctuation in the cylinder below the piston accompanying the vertical movement of the piston during engine operation can be reduced.
A rear jacket portion of the first water jacket formed separately between the adjacent cylinder portions in the front-rear direction of the vehicle body is defined as a rear rear wall at a substantially central portion in the circumferential direction of the cylinder portion. than the jacket portion formed therein biases the front side, between the cylinder portion in which the adjacent by placing the mounting screw holes on the rear side of the jacket portion of the rear side of the mounting screw hole and the communication hole By forming the second passage that communicates with each other, the plating solution can be easily discharged from the second passage when the piston sliding surface of the cylinder portion is plated.
[0011]
Further, the second passage can be formed with a simple structure and without greatly changing the cylinder block, that is, without impairing the basic performance, by penetrating the pilot hole of the mounting screw hole of the cylinder head.
[0012]
In addition, according to the present invention, an engine including a plurality of cylinder parts having piston sliding surfaces and a first water jacket for cooling on the outer periphery of the cylinder part from substantially the center to the upper part in the cylinder longitudinal direction. An engine in which an opening communicating with the first water jacket and the second water jacket on the cylinder head side and a mounting screw hole for mounting the cylinder head are formed on the mating surface with the cylinder head By forming a plating film on the piston sliding surface, it is not necessary to provide a cylinder liner. Therefore, the number of parts can be reduced and the cost can be reduced.
In addition, a communication hole is formed in the cylinder block of the engineon so as to extend in the width direction of the cylinder block in the cylinder arrangement direction and to communicate the communication hole and the mounting screw hole. Cylinder surfaces of two cylinder blocks are closely bonded to each other and the piston sliding surface is plated, and after plating, the two cylinder blocks are stacked in the vertical direction, and the cylinder located on the upper side The plating solution in the cylinder block after the plating process is discharged from the cylinder head by discharging the plating solution in the block through a passage that connects the communication hole and the mounting screw hole in the cylinder block located on the lower side. The cylinder block is taken out from the plating tank with the mating surface facing downward. Thus, the plating solution in the water jacket of the cylinder block is discharged, and at the same time, the plating solution accumulated inside the cylinder block (when the inside is formed in a concave shape) is discharged through the second passage. Can do.
Therefore, the plating solution can be easily drained without rotating the cylinder block.
[0013]
Also, the number of man-hours for the plating process can be reduced by closely joining the mating surfaces of the two cylinder blocks with the cylinder head and plating the two cylinder blocks simultaneously. Further, by tightly bonding the mating surfaces, the plating solution can be prevented from flowing into the water jacket, and the plating solution in the upper cylinder block is passed through the second passage in the lower cylinder block. Therefore, the plating solution can be drained safely and easily without rotating a heavy, large cylinder block.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an overall view showing a configuration of a motorcycle equipped with an engine according to an embodiment of the present invention, FIG. 2 is an explanatory view showing the overall configuration of the engine, and FIG. 3 is an overall view of a cylinder block structure of the engine. FIG. 4 is a side view showing the configuration of the upper case according to the present embodiment, FIG. 5 is a view taken in the direction of arrow X in FIG. 4, FIG. 6 is a view taken in the direction of arrow Y in FIG. 4 is a sectional view taken along the line AA of the upper case in FIG. 4, FIG. 8 is a sectional view taken along the line BB of the upper case in FIG. 6, and FIG. These are explanatory drawings which show the state at the time of performing the plating process of a piston sliding surface.
[0015]
In this embodiment, as shown in FIGS. 1 and 2, an engine 2 is disposed in the motorcycle 1 below the substantially central portion of the vehicle body frame 3, and the crankshaft 4 is disposed horizontally with respect to the vehicle body traveling direction. The cylinder portion 6 is suspended in a forwardly inclined direction toward the front in the direction. An air cleaner box 7 is disposed above the engine 2 via a vehicle body frame 3 and further above the air cleaner box 7. A fuel tank 8 is arranged so as to surround the fuel tank. A radiator 9 is disposed in front of the engine 2 in the vehicle traveling direction.
[0016]
As shown in FIGS. 2 to 5, the engine 2 is a four-cycle four-cylinder engine having four cylinder parts 6 formed in parallel, and a cylinder block having a water jacket 11 for cooling the cylinder parts. 12, and an upper case 14 including the cylinder block 12, a middle case 15, and a lower case 16. The upper and lower split crankcase 10 is roughly divided into a cylinder head 17, an upper case 14, a middle case 15, The lower case 16 is arranged in this order.
[0017]
An exhaust manifold 18 is provided on the front side of the cylinder head 17 in the vehicle traveling direction, an intake manifold 19 is provided on the rear side of the vehicle traveling direction, and a cooling second is provided in the vicinity of the exhaust manifold 18 and the intake manifold 19. The water jacket 20 is formed.
An exhaust pipe 21 is connected to the front side of the exhaust manifold 18 in the vehicle traveling direction. The exhaust pipe 21 extends downward along the front side of the engine 2 main body, extends around the lower side of the engine 2 and extends toward the rear of the vehicle body.
A throttle body 22 is disposed behind the intake manifold 19 in the vehicle body traveling direction, and communicates with the air cleaner box 7 via the throttle body 22.
The air cleaner box 7 communicates with a breather cover 25 installed on the upper part of the middle case 15 via a breather hose 24 connected to the lower rear end thereof.
[0018]
A cooling water union 27 is disposed on the rear side of the upper case 14 in the vehicle body traveling direction, and is connected to a water pump 29 described later via a water hose (cylinder block side) 28.
An oil pan 30 is disposed below the lower case 16, an oil filter 31 is disposed on the front side in the vehicle body traveling direction, and a water pump 29 is disposed on the left side in the vehicle body width direction substantially at the center of the lower case 16. Yes.
The water pump 29 is connected to the radiator 9 via a water hose (radiator side) 33 on the radiator 9 side, and the cooling water cooled by the radiator 9 is supplied to the cylinder via the union 27 by the water pump 29. The water jackets 11 and 20 (described later) formed in the block 12 and the cylinder head 17 are supplied.
[0019]
As shown in FIGS. 3 and 4, the upper case 14 is formed by integrally forming a cylinder block 12 at an upper portion and forming an upper crank chamber 14 a at a lower portion.
As shown in FIGS. 3 to 9, the cylinder block 12 includes four cylinder parts 6 arranged in parallel. The outer periphery of the cylinder part 6 has a first water for cooling from a substantially center to an upper part in the cylinder longitudinal direction. A jacket 11 is formed. The union 27 is disposed at substantially the same height as the first water jacket 11.
[0020]
As shown in FIGS. 3, 7, and 8, an oil passage 35 extends below the first water jacket 11 in the cylinder arrangement direction in the width direction of the cylinder block 12. It is installed.
A communication hole 36 is formed in the rear wall of the cylinder block 12 in the vehicle body traveling direction so as to be substantially the same height as the oil passage 35 and below the first water jacket 11.
[0021]
The communication hole 36 extends in the cylinder arrangement direction inside the rear wall, and is formed in the vicinity of the outer side of the rotation locus 40 by the crank web outer end portion (not shown) of the crankshaft 4. Further, a first passage 38 is formed in the crank chamber side wall of the cylinder block 12 to communicate the communication hole 36 with the crank chamber.
[0022]
As shown in FIGS. 6 and 7, the first passage 38 is formed at two locations described later with respect to each cylinder portion 6 on the rear side in the vehicle body traveling direction of the cylinder block 12, and the upper portion 38 a The upper side portion 36a of the communication hole 36 is substantially at the same position, and the lower side is open to the crank chamber.
As shown in FIG. 5, the first water jacket 11 and the second water jacket 20 formed on the cylinder head 17 communicate with the mating surface 13 of the cylinder block 12 with the cylinder head 17. An opening 12a and a mounting screw hole 12b for mounting the cylinder head 17 are formed.
[0023]
A part of the mounting screw hole 12b is arranged above the communication hole 36, and three inner holes (marked with * in FIG. 5) in the inside reach the communication hole 36. The screw hole 12b and the communication hole 36 are communicated by a pilot hole 12c as a second passage.
[0024]
Near the lower side of the communication hole 36 of the cylinder block 12, the inner wall portion of the cylinder block 12 and the outer wall of the cylinder portion 6 in a direction orthogonal to the cylinder arrangement direction at a substantially central portion in the circumferential direction of each cylinder portion 6. A bridge portion 44 is formed by connecting the portions.
[0025]
The positional relationship between the first water jacket 11 and the communication hole 36 is such that the first water jacket 11 has a lower portion 11a disposed at substantially the same height as the piston apex 41a at the bottom dead center of the piston 41. The communication hole 36 has an upper portion 36a disposed below the piston apex 41a at the bottom dead center of the piston 41, and a lower portion 36b of the communication hole 36 at the lower end of the skirt portion 42 of the cylinder inner wall. Are disposed at substantially the same height.
[0026]
Next, the plating process of the piston sliding surface of the cylinder block will be described with reference to the drawings.
FIG. 10 is an explanatory view showing a state when the piston sliding surface is plated according to the present embodiment.
When the piston sliding surface 6a of the cylinder block 12 is plated, it is usually performed by electrolytic plating.
[0027]
First, as shown in FIG. 10, the mating surfaces 13 of the cylinder blocks 12 of the two upper cases 14 and the cylinder heads 17 are overlapped, and sandwiched by two set jigs 52 in this state, and these are attached to four pieces. By tightening with bolts 54, the two mating surfaces 13 are tightly fixed.
The setting jig 52 has a rectangular plate shape, and an opening 53 is formed at a position substantially opposite to the opening 14b of the upper case 14 at a position substantially smaller than the opening 14b.
[0028]
Next, with the two upper cases 14 being stacked substantially vertically, the entire upper case is immersed in the plating solution 51 in the plating tank 50 with the crank case side of one upper case 14 facing down. The electrode rod 55 is disposed substantially vertically at the approximate center in the cylinder.
And the electrolytic plating process of the piston sliding face 6a is performed.
[0029]
After the completion of the plating process, the two upper cases 14 are pulled up substantially vertically from the plating tank 50 to drain the plating solution. At this time, since the upper case 14 disposed on the lower side opens downward, the plating solution is drained without accumulating in the case.
On the other hand, in the case of the upper case 14 disposed on the upper side, since the overall shape is opened upward in a bowl shape, most of the plating solution is discharged from the opening of the cylinder portion, but the plating solution is accumulated in the case. easy.
[0030]
However, since the inner shape of the case is substantially curved, and the first passage 38 is arranged at the lowest position in the inverted state, the plating solution in the case is the first solution. Into the passage 38.
The plating solution that has flowed into the first passage 38 enters the communication hole 36, and is discharged out of the upper case 14 through the lower hole 12 c of the attachment screw hole 12 b that penetrates the communication hole 36.
[0031]
Here, since the mounting screw hole 12b of the upper upper case 14 and the mounting screw hole 12b of the lower upper case 14 are overlapped with each other, the plating solution discharged from the upper mounting screw hole 12b is lower. Enters the side mounting screw hole 12 b and is discharged from the first passage 38 through the communication hole 36. Therefore, all the plating solution accumulated in the upper case is discharged.
[0032]
According to the above configuration, the communication holes 36 extend in the cylinder arrangement direction inside the cylinder block 12, and the communication holes 36 communicate with the crank chamber side walls of the cylinder block 12. Since the passage 38 is formed, the weight of the cylinder block 12 can be reduced, and fluctuations in the pressure force in the cylinder portion 6 on the lower side of the piston 41 due to the vertical movement of the piston 41 during engine operation can be reduced.
In addition, since the lower hole 12c of the mounting screw hole 12b is passed through the communication hole 36 as a second passage that connects the mounting screw hole 12b of the cylinder head 17 and the communication hole 36, the piston sliding surface of the cylinder portion 6 When plating 6a, the plating solution can be easily discharged from the prepared hole 12c of the mounting screw hole 12b.
[0033]
Further, since the pilot hole 12c of the mounting screw hole 12b of the cylinder head 17 is passed through the communication hole 36, the second passage can be formed with a simple structure and without greatly changing the cylinder block 12. The screw hole and the communication hole can be communicated with each other.
[0034]
Further, since the plating film is formed on the piston sliding surface 6a, it is not necessary to provide a cylinder liner, and therefore the number of parts can be reduced and the cost can be reduced. Further, the plating solution in the cylinder block 12 after plating is discharged from the mating surface 13 side with the cylinder head 17, that is, the cylinder block 12 is taken out from the plating tank with the mating surface 13 facing downward. For example, the plating solution in the water jacket 11 of the cylinder block 12 is discharged, and at the same time, accumulated inside the cylinder block 12 (when the inside is formed in a concave shape) via the prepared hole 12c of the mounting screw hole 12b. The plating solution can be discharged. Therefore, the plating solution can be easily drained without rotating the cylinder block 12.
[0035]
Also, the number of man-hours for the plating process can be reduced by closely bonding the mating surfaces of the two cylinder blocks 12 with the cylinder head 17 and plating the two cylinder blocks 12 simultaneously. Further, the mating surfaces 13 of the cylinder block 12 are opposed to each other, closely joined and overlapped in the vertical direction, so that it is possible to prevent the plating solution from flowing into the water jacket 11, and the inside of the upper cylinder block 12. Since the plating solution can be discharged through the pilot hole 12c in the lower cylinder block 12, the plating solution can be drained safely and easily without rotating the heavy cylinder block 12.
[0036]
It should be noted that the cylinder block structure of the engine of the present invention is not limited to the illustrated examples described above, and it is needless to say that various modifications can be made without departing from the scope of the present invention. For example, in this embodiment, the pilot hole 12c of the mounting screw hole 12b is extended to the communication hole 36 as the second passage. However, as a modified example, the second passage is not limited to one formed by drilling. Alternatively, it may be formed as a cast hole.
[0037]
【The invention's effect】
As described above, according to the engine cylinder block structure and the engine cylinder block plating method of the present invention, the plating solution can be drained with a simple configuration without rotating the heavy cylinder block during the plating process. realizable. That is, it is possible to provide an engine cylinder block structure and an engine cylinder block plating method that improve the drainability of the plating solution, reduce the amount of the plating solution taken out, and improve the workability.
[Brief description of the drawings]
FIG. 1 is an overall view showing a configuration of a motorcycle equipped with an engine according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing an overall configuration of the engine.
FIG. 3 is a partial cross-sectional assembly view showing the entire cylinder block structure of the engine according to the present embodiment.
FIG. 4 is a side view showing a configuration of an upper case according to the present embodiment.
5 is a cross-sectional view of the upper case of FIG. 4 as viewed from the X direction.
6 is a view of the upper case of FIG. 4 as viewed from the arrow Y. FIG.
7 is an AA cross-sectional view of the upper case of FIG. 4;
8 is a cross-sectional view of the upper case of FIG. 6 taken along the line B-B.
9 is a cross-sectional view taken along the line CC of the upper case of FIG. 6;
FIG. 10 is an explanatory view showing a state when the piston sliding surface according to the embodiment is plated.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Engine 4 Crankshaft 6 Cylinder part 6a Piston sliding surface 11 1st water jacket 11a Lower side part 12 Cylinder block 12a Opening part 12b Mounting screw hole 12c Lower hole 13 Matching surface 14 Upper case 14a Crank chamber upper part 17 Cylinder head 20 Second water jacket 35 Oil passage 36 Communication hole 36a Upper portion 36b Lower portion 38 First passage 38a Upper portion 40 Rotation locus 41 Piston 41a Piston apex position (bottom dead center)
42 Skirt portion 44 Bridge portion 50 Plating tank 51 Plating solution 52 Setting jig 53 Opening portion 54 Bolt 55 Electrode rod

Claims (3)

An engine comprising a plurality of cylinder parts having piston sliding surfaces, and a first water jacket for cooling formed on the outer periphery of the cylinder part from approximately the center to the upper part in the longitudinal direction of the cylinder,
An engine cylinder block in which an opening communicating with the first water jacket and the second water jacket on the cylinder head side and a mounting screw hole for attaching the cylinder head are formed on a mating surface with the cylinder head ,
Inside the cylinder block, a first passage is formed under the first water jacket so as to extend a communication hole in the cylinder arrangement direction in the width direction of the cylinder block and to communicate the communication hole with the crank chamber. And
The rear jacket portion of the first water jacket formed separately between the adjacent cylinder portions in the front-rear direction of the vehicle body is placed inside the rear wall behind the substantially central portion in the circumferential direction of the cylinder portion. Biased to the front side of the formed jacket part,
Between the adjacent cylinder portions, the mounting screw hole is disposed on the rear side of the rear jacket portion to form a second passage that communicates the mounting screw hole and the communication hole. Engine cylinder block structure.   2. The second passage according to claim 1, wherein the mounting screw hole and the communication hole are communicated with each other by penetrating a pilot hole of a mounting screw hole of the cylinder head through the communication hole. Engine cylinder block structure. An engine comprising a plurality of cylinder parts having piston sliding surfaces, and a first water jacket for cooling on the outer periphery of the cylinder part from substantially the center to the upper part in the longitudinal direction of the cylinder, The piston sliding surface of the engine is plated with an opening for communicating the first water jacket and the second water jacket on the cylinder head side and a mounting screw hole for mounting the cylinder head on the mating surface In a plating method for forming a film,
In the cylinder block of the engine, the communication hole extends in the width direction of the cylinder block in the cylinder arrangement direction, and a passage that connects the communication hole and the mounting screw hole is formed .
The mating surfaces of the cylinder heads of the two cylinder blocks are closely bonded to each other, and the piston sliding surface is plated.
After the plating process, with the two cylinder blocks stacked vertically, the plating solution in the cylinder block located on the upper side communicates with the communication hole in the cylinder block located on the lower side and the mounting screw hole. A cylinder block plating method for an engine, wherein the exhaust is discharged through a passage .

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