JP2002242753A - Cylinder block structure of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling efficiency in a cylinder block of an engine and the serviceability of a cooler in the engine because a cooling water passage formed at a conventional cylinder block allows for only a contact area between cooling water and a cylinder peripheral section and no careful consideration is given to a flow of cooling water in the cooling water passage, so that cooling efficiency is not always high. SOLUTION: The shape of a head bolt boss 94 which comes into contact with the cooling water passage 37 formed in the cylinder block and positioned between cylinders is formed so as to be asymmetrical between the upstream and downstream of the cooling water passage 37, and a water jacket formed in the cylinder block is extended to the crankcase section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure of a cylinder block constituting an engine.

[0002]

2. Description of the Related Art Conventionally, a cooling water path formed in a cylinder block is configured around the cylinder so as to surround the cylinder. Then, cooling water flows through the cooling water path to cool the cylinder. In addition, the drain hole of the cooling water path formed in the cylinder block is formed on the side surface of the cylinder block, but is not located at the bottom of the cooling water path. Further, the cooling water path of the cylinder block is arranged at a position higher than the lubricating oil path due to the arrangement relation with the gallery of the lubricating oil formed in the cylinder block.

[0003]

The cooling water path formed in the conventional cylinder block takes into account only the contact area between the cooling water and the cylinder periphery, and particularly takes into account the flow of the cooling water in the cooling water path. Because it was not done
The cooling efficiency was not always good. Further, the cooling water path formed in the cylinder block considers only cooling of the cylinder, and does not particularly consider cooling of lubricating oil circulating in the cylinder block. Furthermore, since the drain hole of the cooling water path is configured at a position higher than the bottom of the cooling water path, it is difficult to completely remove the cooling water, and the cooling water remains in the cooling water path for a long time. Otherwise, the cylinder block may be deteriorated.

[0004]

According to a first aspect of the present invention, in a cylinder block structure of an engine comprising a cylinder portion for accommodating a piston and a skirt portion for covering a crankshaft, the cylinder block is provided. The shape of the head bolt boss that is in contact with the cooling water path and located between the cylinders is formed asymmetrically between the upstream side and the downstream side of the cooling water path.

According to a second aspect of the present invention, in a cylinder block structure of an engine comprising a cylinder portion for accommodating a piston and a skirt portion for covering a crankshaft, a water jacket formed on the cylinder block is provided with a crankcase. Part was extended.

According to a third aspect of the present invention, the water jacket extends below the lubricating oil passage.

According to a fourth aspect of the present invention, the cooling water drain hole formed in the cylinder block is provided below the lubricating oil gallery.

[0008]

Next, an embodiment of the present invention will be described. 1 is a side sectional view showing an engine, FIG. 2 is a front sectional view of the same, FIG. 3 is a view showing an assembly configuration of a cylinder block, FIG. 4 is a left side view of the engine, FIG. Similarly, FIG. 7 is a side sectional view, FIG. 8 is a sectional view showing the shape of a head bolt boss, FIG.
5 is a sectional view taken along line BB in FIG. 5, FIG. 10 is a sectional view taken along line AA in FIG. 4, FIG. 11 is a front view of a cylinder block,
FIG. 12 is a sectional view taken along line CC in FIG.

The schematic structure of the engine will be described with reference to FIGS. A cylinder head 1 is attached to an upper end of a cylinder block 15 of the engine E, and a valve arm chamber 2 is formed above the cylinder head 1.

The driving force from the crankshaft 25 is applied to the front surface of the cylinder block 15 by the camshaft 14 and the fuel injection pump 1.
Gear case 2 for storing gears and the like for transmitting to gear 2 and the like
3 are connected. A flywheel housing 27 that accommodates a flywheel 28 is connected to the other surface of the cylinder block 15.

An oil pan 21 is provided below the cylinder block 15, and lubricating oil is stored in the oil pan 21. The oil pan 21 is connected to the cylinder block 15 via the spacer 18. Spacing 18
Is the gear case 2 from one end of the cylinder block 15.
3 and the gear case cover 29 extending to the gear case cover 29 and connected to the cylinder block 15.
Is further connected to the spacer 18, and a gear case cover connected to the gear case 23 is also connected to the spacer 18.

A lubricating oil intake passage 81, which is a lubricating oil passage, is formed in the spacer 18, and the oil pan 21
It communicates with a lubricating oil suction pipe 19 protruding inward. The lubricating oil stored in the oil pan 21 is sucked into the lubricating oil pump 22 through the lubricating oil suction pipe 19 and the lubricating oil suction passage 31.

A crankshaft 25 is held below the cylinder block 15. The crankshaft 25 is held by a journal housing 38 of the cylinder block 15 and a journal housing 39 fixed to the cylinder block 15. The journal housing 39 is fixed below the front and rear ends of the cylinder block 15 and between the cylinders.
5 is supported from below.

Next, the structure of the cylinder block 15 will be described with reference to FIGS. The cylinder block 15 includes a cylinder portion 31 and a skirt portion 32. The cylinder portion 31 is formed by integrally casting an inner cylinder and an outer cylinder, and a piston 3 is provided inside the cylinder portion 31.
3 is provided. In the cylinder section 31, a cooling water passage is formed between the inner cylinder and the outer cylinder, and a camshaft case 53 is formed on one side. And, on both side surfaces of the cylinder block 15, cleaning holes 34 and 45 communicating with the cooling water passage are formed.
Cleaning hole 4 provided on the same side as camshaft case 53
5 is located below the camshaft case 53,
The inside lower end of the cleaning hole 45 constitutes the lowermost part of the cooling water path.

The cleaning holes 34 and 45 are provided in the cylinder block 1
5 is formed by a core supporting member when casting 5. That is, a core is used to form the cooling water path 37. In the mold, the core is supported by a support member.
45 is configured. Some of the cleaning holes 34 and 45 are used as paths for introducing and discharging cooling water, and the other cleaning holes 34 and 45 are provided with plugs 120. As a result, the cleaning holes 34 and 45 are sealed,
It becomes a plug hole. The cleaning holes 34 and 45 are openings that communicate with the cooling water path 37 in the cylinder block 15. For this reason, there is a possibility that the rigidity is reduced near the cleaning holes 34 and 45. However, the ribs are connected to the cleaning holes 34 and 45, so that the rigidity is suppressed from being reduced.

In the skirt portion 32, the lower portion of each cylinder has a curved configuration. The side surface of the skirt portion 32 has a curved shape when viewed from the front, and also has a curved shape when viewed in a plan view. That is, it has a curved shape in both the longitudinal section and the transverse section. Further, ribs are provided inside and outside of the skirt portion 32 to improve the rigidity of the skirt portion 32. By improving the rigidity of the skirt portion 32, when a member is mounted on the surface of the skirt portion 32,
The deformation of the skirt portion 32 can be suppressed. Rib 3
Reference numeral 5 denotes a cylinder portion 31 and a skirt portion of the cylinder block 15 which are formed in the front-rear direction of the cylinder block 15. The rib 36 is formed in the cylinder 31 and the skirt in the vertical direction of the cylinder block.

The rib 35 formed on the cylinder portion 31 is formed near the cleaning hole 34. Similarly, in the vicinity of the cleaning hole 34, a rib 36 formed in the vertical direction of the cylinder block 15 is also formed. By providing the rib 35 and the rib 36 near the cleaning hole 34, the cleaning hole 34 is provided.
The rigidity in the vicinity can be improved, and the rigidity of the cylinder block 15 can also be improved.

A lubricating oil case 91 is provided on the side of the cylinder block 15, and a main gallery of lubricating oil is formed in the lubricating oil case 91. The lubricating oil case 91 is formed at the center of the side of the cylinder block 15 in the cylinder arrangement direction.
5 are integrally formed.

Next, regarding the configuration of the cleaning holes 34 and 45,
This will be described in more detail with reference to FIG. Cleaning holes 34 and 45
Is formed in a counterbore shape, and the cylinder block 15
In this case, the precision in processing the cleaning holes 34 and 45 is improved. When the cylinder block 15 is formed by casting, the outer portions of the cleaning holes 34 and 45 may be recessed in a bowl shape. In this case, by sitting outside the cleaning holes 34 and 45, the shapes of the cleaning holes 34 and 45 can be made constant, the accuracy of plug attachment can be improved, and the rigidity of the cylinder block 15 can be improved. This prevents leakage of cooling water and improves durability.

Next, the configuration of the cooling water path will be described in detail with reference to FIGS. The cooling water path 37 constituting the water jacket is provided in the cylinder block 15, and the water jacket extends to the crankcase portion. Thereby, the capacity of the water jacket is increased, and the cooling effect of the crankcase portion can be improved. The noise generated inside the water jacket can be cut off by the water jacket, and the noise generated in the engine can be reduced. The cooling water path 37 is formed on the left and right outer sides and the front and rear ends of the cylinder 95, and is connected to the front and rear in the front and rear direction. The cooling water path 37 is formed along the outer surface of the connected cylinder 95, and an outer wall 96 forming the outside of the cooling water path 37.
Is configured to cover the connected cylinder 95. On the outer wall 95, a head bolt boss 94 is formed between the cylinders 95. The head bolt boss 94 is configured substantially symmetrically in the front-rear direction to hold a bolt for fastening the cylinder head in the upper part, and is configured asymmetrically in the front-rear direction of the cylinder block 15 in the lower part. Is what it is. One part of the lower part of the head bolt boss 94 is
, And the other is recessed inside the head bolt boss 94 (away from the cylinder 95). That is, the shape is different between the upstream side and the downstream side of the cooling water path 37. The head bolt boss 94 changes the direction of the cooling water to the cylinder 95
It is aimed at between 95. Thereby, the cooling water path 3
When the cooling water flows into the cylinder 7, the cooling water can be smoothly supplied to the portion between the cylinders, and the cooling effect can be improved.

Next, the cooling water jacket structure of the drain portion will be described with reference to FIGS. As described above, the lubricating oil case 91 is formed on the side of the cylinder block 15, and the lubricating oil gallery 97 is formed in the lubricating oil case 91. Lubricating oil gallery 97
Are connected to the journal housing 38 by an oil passage 98. Further, the inside of the camshaft case 53 is also connected to the journal housing 38 by an oil passage 99. Thereby, the crankshaft 25 and the cylinder block 1
5 can be maintained.

The cooling water path 37 is provided above the lubricating oil gallery 97 in the cylinder block 15. However, as shown in FIG. 10, the drain hole 100 of the cooling water is located below the lubricant gallery 97. Thus, the drain hole 100 is located at the lowest position in the cooling water path 37, so that the cooling water can be efficiently discharged into the cylinder block 15 through the drain hole 100. The drain hole 100 is connected to the cooling water path 37 via the cooling water discharge path 101. The cooling water discharge path 10
1 is a cooling water path 3 inside the lubricant gallery 97
7 and the drain hole 100. Thus, a drain that efficiently discharges the cooling water can be configured without changing the configuration of the lubricating oil gallery 97. Further, the cooling water does not remain in the cooling water path 37, and there is no possibility that the cylinder block is deteriorated.
Further, the water jacket formed by the cooling water path extends to below the lubricating oil path, and the area where the water jacket and the lubricating oil path are close to each other increases,
The cooling effect of the lubricating oil passage can be improved.

Next, the configuration of the camshaft case will be described with reference to FIGS. A groove 110 is formed inside the camshaft case 53. The camshaft case 5
3, a cylindrical space extending in the front-rear direction of the cylinder block 15 is formed.
4 is provided. A space is provided above the space in which the camshaft 14 is provided, and a space communicating in the up-down direction is provided, and a push rod is provided in the space provided above and below. A holding portion 111 is formed inside the camshaft case 53, and the camshaft 14 is held by the holding portion 111. Cylinder block 1
As described above, reference numeral 5 is integrally formed by casting, and the holding portion 111 is formed after casting to form a smooth and uniform surface in order to hold the cam shaft 14 smoothly. .

[0024]

According to the first aspect of the present invention, in a cylinder block structure of an engine including a cylinder portion for accommodating a piston and a skirt portion for covering a crankshaft, a cooling water path formed in the cylinder block is provided. Since the shape of the head bolt boss that is in contact with and located between the cylinders is formed asymmetrically between the upstream side and the downstream side of the cooling water path, the cooling water can be efficiently supplied between the cylinders and the cooling effect can be improved.

According to a second aspect of the present invention, in a cylinder block structure of an engine comprising a cylinder portion for accommodating a piston and a skirt portion for covering a crankshaft, a water jacket formed on the cylinder block is provided with a crankcase. Since it extends to the portion, the capacity of the water jacket is increased, and the cooling effect can be improved. Further, the cooling effect of the crankcase portion can be improved, and noise from inside can be cut off by the water jacket, so that the noise can be reduced.

According to a third aspect of the present invention, since the water jacket extends below the lubricating oil passage, the contact area between the water jacket and the lubricating oil passage can be increased, and the cooling of the lubricating oil passage can be achieved. The effect can be improved.

According to a fourth aspect of the present invention, the cooling water drain hole formed in the cylinder block is provided below the lubricating oil gallery, so that the cooling efficiency can be improved from above to below the lubricating oil passage. it can. And discharge of cooling water can be made easy. Cooling water can be completely extracted from the cooling water path of the engine, thereby improving maintainability. Further, the cooling water does not remain in the cooling water path 37, and there is no possibility that the cylinder block is deteriorated.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an engine.

FIG. 2 is a front sectional view of the same.

FIG. 3 is a diagram showing an assembly configuration of a cylinder block.

FIG. 4 is a left side view of the engine.

FIG. 5 is a right side view of the same.

FIG. 6 is a front sectional view of a cylinder block.

FIG. 7 is a side sectional view of the same.

FIG. 8 is a sectional view showing the shape of a head bolt boss.

FIG. 9 is a sectional view taken along line BB in FIG. 5;

FIG. 10 is a sectional view taken along line AA in FIG. 4;

FIG. 11 is a front view of a cylinder block.

FIG. 12 is a sectional view taken along line CC in FIG. 11;

[Explanation of symbols]

 E engine 1 cylinder head 2 valve arm chamber 14 camshaft 15 cylinder block 18 spacer 19 lubricating oil suction pipe 21 oil pan 25 crankshaft 27 flywheel housing 28 flywheel 31 cylinder part 32 skirt part 33 piston 34 cleaning hole 35, 36 Rib 37 Cooling water path 38/39 Journal housing 45 Cleaning hole 53 Camshaft case 61/62 Rib 81 Lubricating oil suction passage

Claims (4)

[Claims] In a cylinder block structure of an engine comprising a cylinder portion for accommodating a piston and a skirt portion for covering a crankshaft, a head which is in contact with a cooling water path formed in the cylinder block and is located between the cylinders. A cylinder block structure for an engine, wherein a shape of a bolt boss is asymmetrically formed on an upstream side and a downstream side of a cooling water path. 2. In a cylinder block structure of an engine comprising a cylinder portion for accommodating a piston and a skirt portion for covering a crankshaft, a water jacket formed on the cylinder block is extended to a crankcase portion. A cylinder block structure of an engine characterized by the following. 3. The engine cylinder block structure according to claim 2, wherein the water jacket extends below a lubricating oil passage. 4. The engine cylinder block structure according to claim 2, wherein a drain hole of the cooling water formed in the cylinder block is provided below the lubricating oil gallery.