JP2005273469A - Cooling structure of cylinder block - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure of a cylinder block which achieves uniform cooling. <P>SOLUTION: A cooling structure 1 of a cylinder block is equipped with a cylinder block 10 in which water jacket portions 12 are successively provided around a bore wall 11b and a water jacket spacer 20 inserted into the jacket portion 12 so as to create a clearance with the bore wall 11b. Cooling water 100W is supplied to the water jacket portion 12 to make the bore wall 11b uniform. In the bore wall 11b, the upper region 211, the center region 311 and the lower region 411 are sequentially disposed from the side close to an engine head 130 along the moving direction of a piston 50. The upper region 211 and the lower region 411 have wider clearances than the center region 311 has. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cylinder block cooling structure, and more particularly to a cylinder block cooling structure capable of uniformly cooling a bore wall of a cylinder block.

Conventionally, the cooling structure of a cylinder block is disclosed by Unexamined-Japanese-Patent No. 2002-30989 (patent document 1), for example.
JP 2002-30989 A

  As the tendency of the bore wall temperature distribution of the cylinder block of the internal combustion engine, the temperature tends to be higher because the temperature on the upper surface side is higher and the water temperature rises on the downstream side relative to the flow direction of the cooling water. In particular, a technique for setting a water jacket spacer for the heat distribution in the vertical direction and aiming at uniform bore wall temperature is disclosed in the above-mentioned document. However, the heat distribution in the vertical direction was not sufficiently uniform.

  Also, the heat distribution on the downstream side of the cooling water tended to be high. The reason is considered to be that the setting of the flow rate in the region formed by the gap between the water jacket spacer and the water jacket portion was insufficient.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide a cylinder block cooling structure capable of uniformly cooling the cylinder block.

  The cooling structure of the cylinder block according to the present invention includes a water block inserted into the water jacket portion so that a gap is provided between the cylinder block in which the water jacket portion is continuously provided around the bore wall and the bore wall. A cooling structure for the cylinder block that includes a jacket spacer, supplies a cooling medium to the water jacket portion, and equalizes the bore wall temperature, the bore wall from the side close to the engine head along the direction of movement of the piston, It has an upper region, a central region, and a lower region, and the upper region and the lower region have a larger gap than the central region.

  In the cooling structure of the cylinder block configured in this way, in the upper region near the deck surface, the distance between the bore wall and the water jacket is widened, and the gap becomes narrower as it approaches the bottom of the water jacket portion. The gap is widened at the bottom (bottom). Thereby, the flow rate distribution of the cooling medium in the height direction can be controlled, and the temperature of the bore wall can be made uniform in the vertical direction of the bore wall.

  The cooling structure of the cylinder block according to the present invention includes a water block inserted into the water jacket portion so that a gap is provided between the cylinder block in which the water jacket portion is continuously provided around the bore wall and the bore wall. A cooling structure for a cylinder block that includes a jacket spacer, supplies a cooling medium to the water jacket portion, and makes the bore wall temperature uniform by flowing the cooling medium from the upstream side to the downstream side of the water jacket portion. The gap increases as it approaches the downstream side.

  In the cooling structure of the cylinder block configured as described above, the temperature of the water temperature and the temperature is corrected by increasing the distance between the water jacket spacer and the bore wall as it approaches the downstream side with respect to the upstream near the cooling water inlet. Is possible. As a result, uniform cooling of the cylinder block can be realized.

  According to the present invention, it is possible to provide a cylinder block cooling structure capable of uniformly cooling the cylinder block.

  Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
1 is a sectional view of a cooling structure for a cylinder block according to a first embodiment of the present invention. Referring to FIG. 1, a cylinder block cooling structure 1 according to Embodiment 1 of the present invention includes a cylinder block 10 in which a water jacket portion 12 is continuously provided around a bore wall 11b, a bore wall 11b, And a water jacket spacer 20 to be inserted into the water jacket portion 12 so that the gaps W1 to W4 are provided therebetween. The cooling water 100W as a cooling medium is supplied to the water jacket part 12, and the temperature of the bore wall 11b is equalized. The bore wall 11b has an upper region 211, a central region 311 and a lower region 411 from the side close to the engine head 130 along the moving direction of the piston 50 (the direction indicated by the arrow 51), and the upper region 211 and the lower region 411. Then, the gap is larger than the central region 311. Specifically, the gap W3 is smaller than the gaps W1, W2, and W4 in other areas.

  The cylinder block 10 surrounds a cylinder liner assembly 11 located inside, a water jacket portion 12 as a cooling medium passage disposed so as to surround the cylinder liner assembly 11, a water jacket portion 12, and And a cylinder block base 13 facing the cylinder liner assembly 11.

  The cylinder liner assembly 11 includes an iron cylinder liner and an aluminum alloy that surrounds the cylinder liner. The cylinder liner assembly 11 has a bore region 111 into which the piston 50 is inserted, and the bore region 111 is a substantially cylindrical region. A plurality of bore regions are arranged in one direction.

  The number of bore regions 111 may be set variously. The cylinder liner assembly 11 has a bore wall 11b. The bore wall 11b is a region cooled by a cooling medium (cooling water 100W) supplied to the water jacket portion 12, and heat generated in the bore region 111 is dissipated from the bore wall 11b to the outside.

  The water jacket portion 12 is an area provided between the cylinder liner assembly 11 and the cylinder block base portion 13 and has a function as a passage for a cooling medium. The water jacket portion 12 has a bottom portion, and the cylinder liner assembly 11 and the cylinder block base portion 13 are connected to the bottom portion. The width of the water jacket portion 12 is configured to be substantially uniform. That is, the distance between the bore wall 11b of the cylinder liner assembly 11 and the cylinder block base portion 13 is substantially equal. In addition, it is not restricted to this structure, The water jacket part 12 may be formed in V shape. That is, the bore wall 11b may have a tapered surface.

  The cylinder block base portion 13 is made of an aluminum alloy and is configured by a method such as die casting. In addition, the material of the cylinder block base part 13 and the cylinder liner assembly 11 is not particularly limited, and may be made of cast iron as well as an aluminum alloy. The cylinder block base portion 13 serves as an engine block, and various accessories provided in the engine are attached. The cylinder block base 13 is provided with an inlet (not shown) of cooling water, and cooling water is introduced into the hole serving as the inlet from the water pump. As a cooling medium, not only cooling water 100W but also various fluids such as long life coolant and oil can be used.

  The water jacket portion 12 is exposed on the deck surface 10d, which is the upper surface of the cylinder block 10, and is an open deck type. A gasket 140 and an engine head 130 are attached on the deck surface 10d. The gasket 140 functions to seal the cooling water 100W flowing through the water jacket portion 12.

  A water jacket spacer 20 is inserted into the water jacket portion 12. The water jacket spacer 20 has a shape along the water jacket portion 12 and surrounds the cylinder liner assembly 11. The material of the water jacket spacer 20 is not particularly limited, and various materials such as aluminum, cast iron, other non-metallic materials, inorganic materials, and resins can be employed.

  A step is formed on the surface of the water jacket spacer 20 facing the bore wall 11b, and the distance between the water jacket spacer 20 and the bore wall 11b varies stepwise. That is, the gaps W1 to W4 between the water jacket spacer 20 and the bore wall 11b are set for each vertical height of the water jacket spacer 20. The flow rate of the cooling water 100W in the vicinity of the bore wall 11b is adjusted by this gap, and the temperature distribution in the vertical direction of the bore wall 11b is made uniform. Specifically, in the region where the height from the deck surface 10d is h2, the gap is W1, the region where the height is from h2 to h3 is the gap W2, and the region where the height is from h3 to h4. Then, the gap is W3, and the gap is W4 in the region from h4 to h5.

  FIG. 2 is a graph showing the relationship between the bore wall temperature and the distance from the deck surface. The dotted line in FIG. 2 is the bore wall temperature before inserting the water jacket spacer, and the solid line is the bore wall temperature after inserting the water jacket spacer. Referring to FIG. 2, before the water jacket spacer 20 is inserted, the bore wall temperature is low in the region where the distance h from the deck surface is from h2 to h4 as indicated by the dotted line, and in the other portions, the bore wall temperature is low. The wall temperature was high. On the other hand, the bore wall temperature after inserting the water jacket spacer is uniform as shown by the solid line.

  FIG. 3 is a table showing an example of setting the gap. Referring to FIG. 3, in the region where the height is from h to h2, the temperature tends to increase as shown by the dotted line in FIG. Therefore, the required cooling amount of the bore wall is large in this region. As a result, the set gap W1 is increased, and the specific value of the gap W1 is 2.0 mm or more.

  On the other hand, in the region where the height is from h2 to h3 and the region from h4 to h5, the required cooling amount of the bore wall is medium as shown by the dotted line in FIG. For this reason, the gaps W2 and W4 in this region are moderate. Specifically, the gaps W2 and W4 are in the range of 0.5 to 2.0 mm.

  Finally, in the region of heights h3 to h4, there is a tendency to be easily cooled. Therefore, the required cooling amount of the bore wall is small. Therefore, the gap W3 is the smallest, and its specific value is 0 to 0.5 mm.

  In other words, in the region where the heat retention is necessary and the height is from h2 to h5, the gap W is set to 0 to 2.0 mm, and in the region where the cooling is positively required and the region from the height h1 to h2 is positive. The gap W is set to 2.0 mm or more.

  FIG. 4 is a graph showing the relationship between the gap and the friction flow velocity near the bore wall surface. Referring to FIG. 4, the frictional flow velocity of the cooling water in the vicinity of the bore wall surface is governed by the gap W between the water jacket spacer and the bore wall. When the gap W between the bore wall and the water jacket spacer is 2 mm or more, the influence of the boundary layer of the bore wall surface is reduced, and the flow velocity increase amount is increased. On the other hand, when the gap W is 2 mm or less, the influence of the boundary layer increases, and the friction flow velocity decreases. That is, there is a linear correlation between the frictional flow velocity in the vicinity of the bore wall 11b and the frictional transmission coefficient of the cooling water. When the gap W between the bore wall and the water jacket spacer is 2.0 mm or more, the rate of increase in the flow rate is increased. Therefore, it is necessary to set the gap to 2.0 mm or less in an area where cooling is not desired, that is, an area where heat is required. It becomes.

  As described above, in the cylinder liner cooling structure according to the first embodiment of the present invention, sufficient cooling is enabled by increasing the flow velocity in a region where aggressive cooling is required.

  Moreover, in the area | region where heat insulation is required, the flow rate is made small by making a clearance gap small, and heat insulation is enabled.

  Therefore, the temperature can be made uniform in the longitudinal direction of the bore wall 11b, and a cylinder liner cooling structure capable of uniform cooling can be provided.

(Embodiment 2)
FIG. 5 is a cross-sectional view of the cooling structure of the cylinder block according to the second embodiment of the present invention. Referring to FIG. 5, in the cylinder block cooling structure 1 according to the second embodiment of the present invention, the surface of the water jacket spacer 20 facing the bore wall 11b has a tapered shape. Different from the cooling structure 1 of the cylinder block according to the first embodiment. That is, in the first embodiment, the water jacket spacer 20 having a stepped surface is used, but in this embodiment, the water jacket spacer 20 having a tapered surface is used. In addition, you may use the water jacket spacer 20 which does not have a taper surface but has a curved surface shape, ie, a gentle slope.

  The relationship between the gaps W1 to W4 may be W3 <W2 = W4 <W1 as in the first embodiment. Further, W3 <W4 <W2 <W1 may be set, and W3 <W2 <W4 <W1 may be set.

  The water jacket spacer cooling structure 1 according to the second embodiment of the present invention configured as described above has the same effect as the water jacket spacer cooling structure 1 according to the first embodiment.

(Embodiment 3)
FIG. 6 is a plan view of a cylinder block cooling structure according to the third embodiment of the present invention.

  Referring to FIG. 6, in cylinder block cooling structure 1 according to the third embodiment of the present invention, cylinder block 10 in which water jacket portion 12 is continuously provided around bore wall 11b, bore wall 11b, And a water jacket spacer 20 inserted into the water jacket portion 12 so as to provide a gap therebetween. Cooling water as a cooling medium is supplied to the water jacket portion 12 in the direction indicated by the arrow 101, and the cooling water is caused to flow from the upstream side (cooling water inlet 14) to the downstream side (gasket hole 41) of the water jacket portion 12 to thereby provide a bore. The temperature of the wall 11b is made uniform. As the distance from the upstream side approaches the downstream side, the gaps w1 to w6 increase.

  In the cylinder block cooling structure 1, the cylinder block 10 is cooled by cooling water as a cooling medium. The cylinder block 10 includes a cylinder liner assembly 11, a groove-shaped water jacket portion 12 surrounding the cylinder liner assembly 11, and a cylinder block base portion 13 surrounding the water jacket portion 12.

  The cylinder liner assembly 11 has three bore regions 111, 112, and 113, and has a structure in which an iron alloy that surrounds the bore regions 111, 112, and 113 is surrounded by an aluminum alloy. The cylinder liner assembly 11 is surrounded by a water jacket portion 12 for flowing a cooling medium. The water jacket portion 12 has a groove shape and a shape along the cylinder liner assembly 11. The cylinder block base portion 13 is an engine block body and is made of an aluminum alloy.

  The cylinder block base portion 13 is provided with a cooling water inlet 14 as an inlet for a cooling medium. A gasket (not shown) is provided so as to cover the cylinder block base portion 13, and a gasket hole 41 serving as a cooling medium passage is provided in the gasket. An engine head is mounted on the gasket, and a passage (not shown) connected to the gasket hole 41 is provided in the engine head. The cooling medium passes through this passage to cool the engine head. be able to.

  The water jacket spacer 20 is fitted into the water jacket portion 12 and is configured to have a predetermined gap with the bore wall 11 b of the cylinder liner assembly 11. That is, the cooling water inlet 14 is upstream of the flow, the gasket hole 41 is downstream of the flow, and the gap w gradually increases as it approaches from the upstream to the downstream. These have a relationship of w1 <w2 <w3 <w4 <w5 <w6. In the cylinder block 10, the clearance is w1 to w3 on the intake side 10i, and the clearance is w4 to w6 on the exhaust side 10e. The thickness of the water jacket spacer 20 is not uniform, and the thickness is gradually changed in order to realize the above-described gaps w1 to w6. The flow makes a U-turn on the front side 10f of the cylinder block 10, and the flow turns from the intake side 10i to the exhaust side 10e. On the rear side 10r, the flow continues to the gasket hole 41, and cooling water is guided to the engine head side. The above flow is an example of block advance U-turn cooling. Note that arrows 101 to 103 indicate the flow of cooling water. The flow of the cooling water is not limited to this, and the shape does not make a U-turn, that is, the cooling water is input from the rear side 10r to flow the cooling water to the front side 10f. The present invention can also be adopted in a system in which cooling water is allowed to flow from the rear side to the rear side 10r.

  That is, the gap w between the water jacket spacer 20 and the bore wall 11b is set for each circumferential direction of the cylinder to adjust the coolant flow velocity in the vicinity of the wall surface of the bore wall 11b. Thereby, the wall temperature distribution between the cylinders in the circumferential direction of the bore wall 11b is made uniform.

  FIG. 7 is a graph showing the average temperature of the bore wall in each cylinder. Referring to FIG. 7, the temperature distribution on the intake side 10i and the exhaust side 10e from the bore region 111 as the first cylinder to the bore region 113 as the third cylinder is shown. The dotted line is the average bore wall temperature for the sample without the water jacket spacer, and the solid line is the average bore wall temperature for the sample with the water jacket spacer. As shown in FIG. 7, when there is no water jacket spacer, the bore wall average temperature is the lowest on the intake side (gap w1) of the bore region 111 and on the exhaust side 10e (gap w6) of the bore region 111. The wall average temperature is the highest. This is because the cooling water flowing in from the cooling water inlet 14 cools the bore wall 11b, and the temperature rises in the vicinity of the outlet. That is, the amount of heat taken away from the bore region is related to the difference between the temperature of the bore wall 11b and the temperature of the cooling medium. If this temperature difference is large, the amount of cooling heat also increases. In the vicinity of the cooling water inlet 14, since the temperature of the cooling water is low, the temperature difference from the bore wall 11b becomes large. Therefore, sufficient cooling can be performed in this region, and the average temperature of the bore wall can be lowered. On the other hand, since the cooling water is sufficiently warmed in the vicinity of the outlet, the temperature difference between the bore wall 11b and the cooling water becomes small. Therefore, the amount of heat taken away by the cooling medium is reduced. Therefore, a temperature distribution as shown by the dotted line in FIG. 7 is generated.

  On the other hand, when the water jacket spacer 20 according to the present invention is used, the bore wall average temperature becomes uniform in the circumferential direction of the flow as shown by the solid line. The reason is the smallest gap w1 in the vicinity of the cooling water inlet 14. For this reason, it is possible to prevent a positive flow of cooling water from occurring between the bore wall 11 b and the water jacket spacer 20. Thereby, the supercooling of the bore wall 11b by the cooling water in the vicinity of the cooling water inlet 14 is prevented. On the other hand, the gaps w2 to w6 are gradually increased as approaching the downstream side. By enlarging the gap, a positive flow of cooling water is generated between the bore wall 11b and the water jacket spacer 20, and heat can be taken away from the bore wall 11b by this flow. Since the gap increases as it approaches the downstream side, the cooling water flow rate that contributes to cooling increases toward the downstream side. However, since the temperature difference between the temperature of the bore wall 11b and the cooling water becomes small on the downstream side, a uniform temperature distribution can be realized by maintaining a balance between this temperature difference and the cooling water flow rate.

  FIG. 8 is a graph showing an example of setting the gap for each cylinder. In the present invention, since the gap increases from the upstream to the downstream of the flow, the gap is the smallest on the intake side 10i of the bore region 111 and the gap is the largest on the exhaust side 10e of the bore region 111. As shown in FIG. 8, the gaps w2 and w3 between the intake side 10i of the bore region 112 and the intake side 10i of the bore region 113 may be substantially equal. That is, the gaps in adjacent areas may be set equal.

  FIG. 9 is a graph showing an example of an increase in the coolant temperature. Referring to FIG. 9, the temperature of the cooling water increases from the upstream to the downstream of the flow. This is because the closer to the downstream, the greater the amount of heat held by the cooling water. That is, the cooling water located at the upstream side at a low temperature receives heat from the bore wall 11b, and the heat gradually accumulates, so that the temperature of the cooling water increases from the upstream toward the downstream. If it becomes downstream of the water jacket part 12, as shown in FIG. 9, the water temperature of cooling water will rise and cooling capacity will fall. Thereby, since the temperature of the bore wall 11b tends to rise downstream of the water jacket portion 12, the gap w can be changed for each cylinder, the flow rate can be adjusted, and the wall temperature can be made uniform.

  Although the embodiment of the present invention has been described above, the embodiment shown here can be variously modified. First, the number of bore regions provided in one cylinder block 10 is not limited to the embodiment, and one or more bore regions may be provided.

  Engines to which the present invention is applied include gasoline engines and diesel engines, and the present invention can be applied to various types of engines such as inline, V, W, and horizontally opposed types. Is possible.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied in the field of a cooling structure for a cylinder block of an internal combustion engine.

It is sectional drawing of the cooling structure of the cylinder block according to Embodiment 1 of this invention. It is a graph which shows the relationship between bore wall temperature and the distance from a deck surface. It is a table | surface which shows the example of a setting of a clearance gap. It is a graph which shows the relationship between a clearance gap and the friction flow velocity of the bore wall surface vicinity. It is sectional drawing of the cooling structure of the cylinder block according to Embodiment 2 of this invention. It is a top view of the cooling structure of the cylinder block according to Embodiment 3 of this invention. It is a graph which shows the average temperature of the bore wall in each cylinder. It is a graph which shows the example of a setting of the clearance gap for every cylinder. It is a graph which shows the water temperature rise example of cooling water.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Cylinder block cooling structure, 10 Cylinder block, 11 Cylinder liner assembly, 11b Bore wall, 12 Water jacket part, 13 Cylinder block base part, 20 Water jacket spacer, 50 Piston, 100W Cooling water, 130 Engine head, 211 Upper part Area, 311 Central area, 411 Lower area.

Claims (2)

A cylinder block in which a water jacket portion is continuously provided around the bore wall;
A water jacket spacer inserted into the water jacket portion so that a gap is provided between the bore wall and the bore wall;
A cooling structure of a cylinder block that supplies a cooling medium to the water jacket portion and equalizes the bore wall temperature,
The bore wall has an upper region, a central region, and a lower region from the side close to the engine head along the moving direction of the piston,
The cylinder block cooling structure in which the gap is larger in the upper region and the lower region than in the central region. A cylinder block in which a water jacket portion is continuously provided around the bore wall;
A water jacket spacer inserted into the water jacket portion so that a gap is provided between the bore wall and the bore wall;
A cooling structure of a cylinder block for supplying a cooling medium to the water jacket portion and flowing the cooling medium from the upstream side to the downstream side of the water jacket portion to equalize the bore wall temperature;
A cooling structure for a cylinder block, wherein the gap increases as it approaches the downstream side from the upstream side.

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