JP2546495Y2 - Engine cylinder block structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cylinder block structure of a build-in type in which a water pump is directly incorporated in a cylinder block.

[Conventional technology]

In general, a water jacket is formed inside a cylinder block of an engine, and a water pump is provided on the front side. As a structure of a portion where the water pump is disposed, a build-in type is conventionally known. (See, for example, Japanese Utility Model Laid-Open No. 60-153818). In this build-in type structure, the pump body is directly attached to the front surface of the cylinder block having a hollow portion communicating with the water jacket, so that the pump body and the corresponding cylinder block inner wall have:
A pump chamber accommodating a pump impeller is formed.

[Problems to be solved by the invention]

In this type of conventional structure, a pump chamber formed by an inner wall of a cylinder block or the like has a volute shape having a spiral space on an outer peripheral side of a pump impeller to reduce resistance and the like. A relatively large space exists between the outer periphery of the impeller and the inner wall of the cylinder block. The mounting space for the pump body is partially provided, so that the space has a shape having irregularities.

However, when observing the water flow in the water pump in the conventional structure, turbulence and stagnation have occurred in the space below the pump having the above irregularities, and therefore, the cooling water smoothly flows in the water pump. It did not flow, and the circulation and heat radiation of the cooling water were reduced by the stagnation.

In view of such circumstances, the present invention can improve the cooling efficiency by improving the water flow in the water pump, and furthermore, is effective in improving the rigidity of the bulkhead at the front end side of the cylinder block. It is intended to provide a block structure.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a structure in which a water pump is disposed above a drive shaft of an engine and is a built-in type directly incorporated into a cylinder block. On the inner wall, a cooling water guide is provided in which an end face of a wall between the water pump and the drive shaft is formed in a circumferential shape close to the outer periphery of the pump impeller.

In addition, in addition to this configuration, it is preferable that a cooling water discharge hole to the cylinder head side is formed in the cylinder block above the water pump, and the discharge direction of the cooling water discharge hole is directed to the exhaust system arrangement side.

[Action]

According to the above configuration, the cooling water flowing on the outer periphery of the pump impeller below the water pump is guided in the circumferential direction by the cooling water guide portion, so that a smooth flow of water is obtained. Further, the cooling water guide portion provides a reinforcing effect on the bulkhead on the front end side of the cylinder block.

In addition, if the cooling water discharge hole to the cylinder head side formed in the cylinder block above the water pump is directed to the exhaust system arrangement side, the cooling effect on the exhaust system side where the temperature naturally tends to rise is enhanced. Can be

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

1 and 2, a plurality of cylinder holes 3 surrounded by a cylinder wall 2 are provided in a cylinder block 1, and a water jacket 4 is provided around the cylinder wall 2 inside the cylinder block outer wall. Is formed. At the lower portion of the cylinder block 1, bulkheads 5 and 6 are provided between the front and rear ends and between the cylinders. The journal portion of (engine drive shaft) 8 is journalled. A water pump 10 is provided on the front end side of the cylinder block 1.

The water pump 10 is of a build-in type which is located above the crankshaft and is directly incorporated in the cylinder block 1. That is, the pump impeller
The pump body 12 supporting the cylinder 11 is the cylinder block 1
The cylinder block 1 has a hollow portion 13 communicating with the water jacket 4 and opening at the front of the cylinder block.
Is formed, and the cavity 13 and the pump body 12 constitute a pump chamber 14. The pump impeller 11 protrudes into the cavity 13. A cooling water inlet 15 is formed in the pump body 12, and a cooling water passage for guiding cooling water from a radiator (not shown) is connected to the cooling water inlet 15.

In this structure, in particular, the water pump 10 is provided on the inner wall of the cylinder block below the pump chamber 14 of the water pump 10.
A cooling water guide portion 16 is provided in which an end surface of a wall portion between the crankshaft 8 and the pump shaft 11 is formed in a circumferential direction close to the outer periphery of the pump impeller 11. In other words, the lower part of the periphery of the pump impeller 11, which is indicated by the hatched broken line in FIG. 2 and indicated by the two-dot chain line 17 'in FIG. However, in the structure of the present invention, this portion is also buried with the meat portion 17 of the cylinder block 1, so that the cooling water guide portion 16 is formed with its inner peripheral surface. The peripheral surface of the hollow portion 13 (wall surface around the pump impeller 11) is formed in a circumferential shape including the cooling water guide portion 16, and the rear side of the hollow portion 13 is a water jacket around the cylinder wall 2. 4 in direct communication.

The lower portion of the meat portion 17 forming the cooling water guide portion 16 is connected to the bulkhead 5 on the front end side of the cylinder block 1. Further, the bulkhead 5 is provided with a rib 18 extending obliquely upward avoiding the rotation locus of the counterweight of the crankshaft 8 and a rib-like shape extending obliquely downward behind the meat portion 17 on the side of the cylinder wall. part
19 are in a row. In other words, on the side of the cylinder wall (side in the direction perpendicular to the paper surface of FIG. 1), the water jacket 4 extends from the rear end side of the cooling water guide 17 to the rib-shaped portion.
A lower end wall 4a is formed so as to extend downward through 18.

Further, a cooling water discharge hole 21 is formed in the cylinder block 1 above the pump chamber 14 toward the cylinder head. The cooling water discharge hole 21 penetrates the upper wall of the cylinder block 1 and communicates with the water jacket of the cylinder head 22. The cooling water discharge hole 21 is formed so as to be directed particularly toward the exhaust system. . That is, the cylinder head 22 has an intake port and an exhaust port (not shown).
For example, when the intake port is located on the left side of FIG. 2 and the exhaust port is located on the right side in FIG. 2, the cooling water discharge hole is inclined so that the upper end of the cooling water discharge hole 21 faces right. 21 are formed.

In FIG. 1, reference numeral 23 denotes a pump pulley attached to the pump body 12, which is driven by a crankshaft via a belt. Also,
Reference numeral 25 denotes a piston connected to the crankshaft 8 via a connecting rod 26.

According to the structure of the present embodiment as described above, as the pump impeller 11 of the water pump 10 rotates in a predetermined direction (the direction of the arrow A in FIG. 2) in conjunction with the crankshaft, the cooling water flows into the cooling water inlet 15. 1 (arrow B in FIG. 1), is sent to the outer peripheral side of the pump impeller 11, passes through the periphery of the pump impeller 11, and is sent out to the water jacket 4 from the side (arrow in FIG. 1). C). In this case, since the cooling water guide portion 16 is provided on the inner wall of the cylinder block 1 below the pump near the outer periphery of the pump impeller 11 and along the circumferential direction, the water is also provided below the outer periphery of the pump impeller 11. The cooling water smoothly flows in the circumferential direction until the cooling water reaches the portion to be sent to the jacket 4, so that the flow is prevented from being disturbed or stagnant.

The meat portion 17 forming the cooling water guide portion 16 also serves to reinforce the cylinder block front end side bulkhead 5 connected thereunder, thereby increasing the rigidity of the bulkhead 5. If the rib 18 and the rib-like portion 19 are provided in the vicinity of the bulkhead 5 and the above-mentioned meat portion 17, the rigidity of the bulkhead 5 can be further enhanced. When the rigidity of the bulkhead 5 is increased in this manner, bending deformation of the front end side of the crankshaft due to the explosion load is suppressed, and so-called runout of the crank pulley is suppressed.

On the other hand, in the upper part of the cylinder block 1, the cooling water sent from the water pump 10 is sent to the cylinder head 22 through the cooling water discharge holes 21, but the cooling water discharge holes 21 are disposed in the exhaust system. By being formed so as to be directed to the side, the cooling effect on the exhaust system arrangement side where the temperature naturally tends to increase is enhanced.

[Effect of the invention]

As described above, in the present invention, since the cooling water guide portion is provided on the inner wall of the cylinder block below the build-in type water pump in the vicinity of the outer circumference of the pump impeller and along the circumferential direction, It is possible to prevent turbulence and stagnation of the flow of water around the pump impeller in the section, and improve cooling efficiency by improving the water flow. In addition, the lower portion of the water pump adjacent to the bulkhead on the front end side of the cylinder block, which has been a space in the conventional structure, is filled with the portion forming the cooling water guide portion, thereby increasing the rigidity of the bulkhead. Therefore, there is also an effect of reducing noise caused by vibration of the crank pulley.

In addition, in addition to the above configuration, if a cooling water discharge hole to the cylinder head side is formed in the cylinder block above the water pump, and the discharge direction is directed to the exhaust system arrangement side, the exhaust system is inherently used. The cooling effect on the arrangement side can be enhanced, and the cooling effect can be further enhanced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a sectional view of a main part with a water pump attached, and FIG. 2 is a vertical view of a cylinder block from a front side with the water pump removed. FIG. 1 ... Cylinder block, 10 ... Water pump, 11 ...
... pump impeller, 16 ... cooling water guide, 21 ... cooling water discharge hole.

Claims (2)

(57) [Scope of request for utility model registration] In a built-in type structure in which a water pump is disposed above a drive shaft of an engine and is directly incorporated into a cylinder block, a water pump and the drive are provided on an inner wall of the cylinder block below the water pump. A cylinder block structure for an engine, comprising: a cooling water guide portion having a wall end face between the shaft and an outer peripheral surface of a pump impeller, which is formed in a circumferential direction. 2. A cooling water discharge hole to a cylinder head side is formed in a cylinder block above the water pump, and the discharge direction of the cooling water discharge hole is directed to the exhaust system arrangement side. Item 2. An engine cylinder block structure according to Item 1.