JP2005113764A - Cylinder block cooling structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder block cooling structure, capable of equalizing cylinder bore wall temperature between cylinders by disposing a spacer on a water jacket, in which both insufficient cooling on the cooling water outlet side and excess cooling on the cooling water inlet side can be prevented. <P>SOLUTION: In this cylinder block cooling structure, the spacer 20 is disposed on the water jacket 10 of a cylinder block. (1) The cross sectional area of a main cooling passage 18 is not enlarged on the downstream side, while contact area with a cylinder bore wall of the main cooling passage 18 is set larger on the downstream side. (2) On the spacer 20, a spacer extension part 24 for preventing penetration of cooling water is provided close to an introducing part for cooling water to the water jacket. (3) At a spacer part of a cylinder bore at an end of the cylinder bore line, in the facing direction to the cylinder bore line, a spacer extended part 26 is provided for restricting excess cooling of the cylinder bore wall. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

Conventionally, Japanese Patent Laid-Open No. 2002-30989 discloses that a spacer (which may be referred to as an “insert”) formed separately from a cylinder block is disposed in a water jacket so that the temperature distribution of the cylinder bore wall (water jacket inner wall) is uniform. A cooling structure for a cylinder block is disclosed.
In the cylinder block cooling structure disclosed in the above publication, in order to improve the inter-cylinder temperature distribution in the cylinder bore wall,
(I) The heat transfer coefficient of the spacer is small at the cooling water inlet and large at the cooling water outlet.
(Ii) The cooling water passage cross-sectional area that touches the outer peripheral surface of the cylinder bore wall is small at the cooling water inlet and large at the cooling water outlet.
(Iii) A throttle is provided on the cooling water outlet side to increase the downstream flow velocity.
(Iv) An independent path is provided in the spacer so that the cold water is routed around the cylinder bore wall away from the cooling water inlet;
It has at least one of the structures.

However, the above cooling structure still has the following problem to be solved.
(I) In a structure in which the heat transfer coefficient of the spacer is small at the cooling water inlet and large at the cooling water outlet, the heat transfer coefficient of the solid spacer is considerably smaller than the heat transfer coefficient of the cooling water having a flow velocity. Insufficient cooling on the cooling water outlet side. If the amount of cooling water is increased so as not to cause insufficient cooling on the cooling outlet side, excessive cooling occurs on the cooling inlet side.
(Ii) In the structure in which the cooling water passage cross-sectional area is small at the cooling water inlet and large at the cooling water outlet, the flow rate of the cooling water decreases toward the outlet side, the heat transfer coefficient decreases significantly, and cooling on the cooling water outlet side is reduced. Run short.
(Iii) In a structure in which a throttle is provided on the cooling water outlet side to increase the flow velocity on the downstream side, the amount of water passing through the water hole or air vent hole in the cylinder head gasket to the water jacket in the cylinder head increases, resulting in an increase in the water jacket in the cylinder block. Since the flow rate on the outlet side of the water is significantly reduced, the cooling capacity on the outlet side is reduced in terms of heat capacity, and cooling on the cooling water outlet side is insufficient.
(Iv) In a structure in which cooling water is routed through the bypass circuit around the cylinder bore wall away from the cooling water inlet, the cooling of the inlet is insufficient if the bypass circuit is wide, and the bypass flow is insufficient if the inlet is wide. Insufficient cooling on the outlet side.
JP 2002-30989 A

  The problem to be solved by the present invention is that when a spacer is arranged on the water jacket and the cylinder bore wall temperature (water jacket inner wall temperature) is made uniform among the cylinders, the cooling on the cooling water outlet side is not performed in the conventional cooling structure. If the cooling water outlet side is not short enough to prevent insufficient cooling, the cooling water inlet side will be overcooled.

  The object of the present invention is to provide a spacer in the water jacket to make the cylinder bore wall temperature (water jacket inner wall temperature) uniform among the cylinders, so that neither cooling on the cooling water outlet side nor excessive cooling on the cooling water inlet side occurs. An object of the present invention is to provide a cooling structure for a cylinder block which does not occur.

The present invention for achieving the above object is as follows.
(1) A cooling structure of a cylinder block in which a spacer is disposed in a water jacket of the cylinder block, wherein the main cross-sectional area of the main cooling passage at the upper part of the water jacket is prevented from becoming wider on the downstream side. A cooling structure of a cylinder block in which the cross-sectional shape of the spacer is changed in the cooling water circulation direction so that the contact area of the cooling passage with the cylinder bore wall increases toward the downstream side.
(2) The cylinder block cooling structure according to (1), wherein the cross-sectional shape of the spacer is changed stepwise before and after the water hole in the cooling water flow direction so that the flow velocity is substantially the same before and after the gasket water hole.
(3) Cylinder block cooling structure in which a spacer is arranged in the water jacket of the cylinder block, and the stagnation of the coolant to the cylinder bore wall side is suppressed in the vicinity of the introduction portion of the coolant to the water jacket. A cooling structure for a cylinder block provided with a spacer extension extending in the vertical direction along the cylinder bore wall. The structure (3) may be subordinate to the structure (1). That is, the structure (3) may be adopted simultaneously with the structure (1).
(4) The cylinder block cooling structure according to (3), wherein the spacer extension is provided with a flange that is bent from the spacer extension.
(5) The cooling structure of the cylinder block according to (3), wherein a squeezing suppressing member that suppresses sneaking of cooling water to the cylinder bore wall side is provided in the spacer extension part in the spacer extension part.
(6) A cooling structure for a cylinder block in which a spacer is disposed in the water jacket of the cylinder block, and a portion of the spacer facing the cylinder bore wall of the cylinder bore at the end of the cylinder bore row in the cylinder bore row direction from the cylinder bore row direction. The cooling structure of the cylinder block which provided the spacer extension part extended in an up-down direction along the cylinder bore wall which suppresses cooling of the cylinder bore wall. The structure of (6) may be subordinate to the structure of (1). That is, the structure (6) may be adopted simultaneously with the structure (1).

According to the cooling structure of the cylinder block of (1) above, the cross-sectional shape of the spacer is changed in the cooling water circulation direction while preventing the passage cross-sectional area of the main cooling passage above the water jacket from becoming wider on the downstream side. Therefore, the flow velocity that most affects the heat transfer rate can be made substantially the same in the cooling water flow direction, and even if the cooling water flows out to the cylinder head side through the water holes, there is no insufficient cooling on the cooling water outlet side. In addition, the temperature of the cooling water rises toward the downstream, and the temperature difference between the bore wall and the cooling water becomes small, but the contact area between the main cooling passage and the cylinder bore wall is increased toward the downstream side. The amount by which the temperature difference of the cooling water becomes small can be offset by the amount by which the contact area with the cylinder bore wall of the cooling passage becomes larger toward the downstream side, and insufficient cooling at the cooling water outlet side does not occur. Further, it is not necessary to increase the amount of cooling water that is necessary when insufficient cooling occurs at the outlet side, and excessive cooling at the cooling water inlet side that occurs when the amount of cooling water is increased does not occur.
According to the cooling structure of the cylinder block of (2) above, since the cross-sectional shape of the spacer is changed stepwise before and after the water hole in the cooling water flow direction, The flow rate before and after the water hole, and thus the heat transfer rate, can be maintained substantially constant.

The cylinder bore on the cooling water inlet side in the cylinder bore row is cooled more strongly than the other cylinder bores by the cooling water flowing in from above and below the spacer, and easily causes a temperature difference between the cylinders. According to the present invention, since the spacer is provided with the spacer extension portion extending in the vertical direction along the cylinder bore wall in the vicinity of the introduction portion to the water jacket of the cooling water, the wraparound of the cooling water to the cylinder bore wall side is suppressed. This can contribute to uniform bore wall temperature between cylinders.
According to the cooling structure of the cylinder block of (4) above, since the flange is provided, it is possible to further suppress the wraparound and contribute to the uniformization of the inter-cylinder bore wall temperature.
According to the cooling structure of the cylinder block of (5) above, since the wraparound suppressing member is provided, the wraparound can be further suppressed and it is possible to contribute to the uniformization of the inter-cylinder bore wall temperature.

  The cylinder bores on the cooling water inlet side and the cooling water outlet side in the cylinder bore row are cooled from one side in the longitudinal direction of the cylinder block in addition to being cooled from two sides in the left and right direction perpendicular to the longitudinal direction of the cylinder block. However, according to the cylinder block cooling structure of (6) above, the cylinder bore wall of the cylinder bore at the end of the cylinder bore row of the spacer is aligned with the cylinder bore row direction. Is provided with a spacer extension extending in the vertical direction along the cylinder bore wall to suppress cooling of the cylinder bore wall from the cylinder bore row direction, so that excessive cooling of the cylinder bore at the end of the cylinder bore row can be suppressed, This can contribute to the uniform temperature of the bore wall between the cylinders.

The cylinder block cooling structure of the embodiment of the present invention will be described with reference to FIGS.
1 and 2 show Embodiment 1 of the present invention, FIGS. 3 and 4 show Embodiment 2 of the present invention, FIGS. 3 and 5 show Embodiment 3 of the present invention, and FIG. 6 shows a fourth embodiment of the present invention, and FIGS. 6 to 7 show a fifth embodiment of the present invention. Portions common to all the embodiments of the present invention are denoted by the same reference numerals throughout the embodiments of the present invention.

First, portions common to all the embodiments of the present invention will be described with reference to FIGS. 1 and 2, for example.
The cylinder block cooling structure 1 of the present invention includes a cylinder block in which a spacer 20 (which may be referred to as an “insert”) is disposed in a water jacket 10 formed in a cylinder block 2 of an internal combustion engine. Cooling structure.
Engine cooling water flows through the water jacket 10 to cool the cylinder bore wall 4 (water jacket inner wall) to an appropriate temperature. The spacer 20 is inserted into the water jacket 10 to change the flow distribution of the engine cooling water in the water jacket 10 to make the temperature of the cylinder bore wall 4 (water jacket inner wall) uniform in the vertical direction of each cylinder bore 3 and between the cylinders. .

  The internal combustion engine has one or more cylinder bores 3 in the cylinder block 2. A water jacket 10 is formed around the cylinder bore 3. In the illustrated example, a plurality of cylinder bores 3 are provided in parallel with each other. The shaft cores of the plurality of cylinder bores 3 are positioned on a straight line extending in the cylinder block longitudinal direction. The illustrated example shows a case where a plurality of cylinder bores 3 are formed in the cylinder block 2. The axis of the cylinder bore 3 extends in the vertical direction, and in the V-type engine in which the left and right banks are V-shaped, it extends in the diagonally vertical direction.

In an in-plane direction orthogonal to the axis of the cylinder bore, the water jacket 10 is formed around the cylinder bore 3 so as to surround the plurality of cylinder bores 3 from the outside.
In the in-plane direction orthogonal to the axis of the cylinder bore, the water jacket 10 has flow paths 14 and 15 extending in the cylinder block longitudinal direction on both the left and right sides of the cylinder bore row, and flow paths 14 and 15 at both ends of the cylinder block longitudinal direction. It has the junction parts 16 and 17 which merge. The water jacket 10 has an engine coolant inlet at one end 16 in the longitudinal direction of the cylinder block and an engine coolant outlet at the other end 17 in the longitudinal direction of the cylinder block.
In a direction parallel to the axis of the cylinder bore, the water jacket 10 is formed on the side of the stroke range of the upper surface of the piston and has substantially the same depth (height) as the stroke range of the upper surface of the piston.

In the present invention, the water jacket 10 is an open deck water jacket that opens upward. The spacer 20 is usually inserted into the water jacket 10 from the upper opening and fixed.
The water jacket 10 is a space formed between a water jacket inner wall 4 that also serves as the cylinder bore wall 4 and a water jacket outer wall 5, and is a space that is covered with a cylinder head via a cylinder head gasket with a bottom wall 6. It is. Engine cooling water flows through the water jacket 10 to cool the periphery of the cylinder bore 3 and cool the combustion chamber from the outside.

  The cylinder head gasket sandwiched between the cylinder block 1 and the cylinder head includes a water hole that allows water to flow from the water jacket 10 in the cylinder block to the water jacket in the cylinder head above and in some places above the water jacket 10. Alternatively, an air vent hole 9 (a hole through which air mixed in water is removed upward when the engine coolant is exchanged) is provided. While engine cooling water flows from the engine cooling water inlet to the engine cooling water outlet, a part of the water in the cylinder head passes through the water hole and / or the air vent hole 9 from the water jacket 10 in the cylinder block. Go out to the jacket.

  The spacer 20 is made of resin, for example. The spacer 20 has a shape and a size that can be inserted into the water jacket 10. The spacer 20 has a shape extending around the cylinder bore 3 in the in-plane direction orthogonal to the axis of the cylinder bore, and extends in the direction parallel to the axis of the cylinder bore. The height is lower than the depth. The spacer 20 has a thickness smaller than the width of the water jacket 10 so that the spacer 20 can be inserted into the water jacket 10. In the state where the spacer 20 is inserted into the water jacket 10, it is normally possible to insert between the inner surface of the spacer 20 and the outer surface of the water jacket inner wall 4 and between the outer surface of the spacer 20 and the inner surface of the water jacket outer wall 5. Clearance remains for. However, either one of the clearances may be zero.

A temperature difference tends to occur between the cylinder bore wall, that is, the water jacket inner wall 4 in the vertical direction and between the cylinders.
In the vertical direction, the cylinder bore wall 4 has an upper portion that receives heat from the explosion and combustion stroke of the engine, so that the temperature of the upper portion of the cylinder bore wall tends to be higher than that of the lower portion.
In order to make the temperature distribution in the vertical direction uniform, the spacer 20 is inserted into the water jacket 10 so that the spacer 20 occupies more space below the upper portion of the water jacket 10. As a result, a large amount of engine cooling water flows to the water jacket upper portion 11 and flows to the water jacket lower portion 12 and the water jacket intermediate portion 13 (height direction intermediate portion) less than the water jacket upper portion 11. The temperature is made uniform in the vertical direction.

The temperature difference between cylinders in the cylinder bore wall 4 is
(A) While the engine cooling water flows through the water jacket 10 from the engine cooling water inlet 7 to the engine cooling water outlet 8, the temperature from the cylinder bore wall 4 is deprived and the temperature rises, and the cylinder bore wall 4 temperature and the engine The difference between the coolant temperature and the downstream side of the engine coolant flow becomes smaller,
(B) The engine cooling water flows out from the water hole and / or the air vent hole 9 to the cylinder head, and the flow rate of the engine cooling water flowing through the water jacket 10 of the cylinder block becomes slower toward the downstream side. The smaller the heat transfer coefficient,
It is caused by. The temperature of the bore wall 4 of the cylinder bore 3 on the downstream side tends to increase.

The temperature difference between the cylinder bore walls 4 is as follows:
(C) Even if the cylinder bore wall 4 facing the engine cooling water inlet 7 has the spacer 20 between the engine cooling water inlet 7 and the cylinder bore wall 4, the engine cooling water flows from the upper and lower sides of the spacer 20 to the cylinder bore wall 4 side. Wrap around and cool strongly,
(D) The cylinder bore wall 4 at the center of the cylinder bore row is cooled from two directions, but the cylinder bore walls 4 at both ends of the cylinder bore row are cooled from three directions, so that they are cooled more strongly.
Also occurs. In this case, the temperature of the bore wall of the specific cylinder bore tends to decrease.

When the temperature of the cylinder bore wall 4 is made uniform among the cylinders, there is insufficient cooling of the downstream cylinder bore wall 4 due to the above (a) and (b), and at the end of the cylinder bore row due to the above (c) and (d). It is necessary to provide a cooling structure that does not cause at least one of excessive cooling of the cylinder bore wall 4 of the cylinder bore.
The structure for making the temperature of the cylinder bore wall 4 uniform among the cylinders is different in each embodiment of the present invention.

Next, parts specific to each embodiment of the present invention will be described.
[Example 1]
In the cylinder block cooling structure 1 according to the first embodiment of the present invention, as shown in FIGS. 1 and 2, the passage cross-sectional area S of the main cooling passage 18 of the upper portion 11 of the water jacket is not made wider on the downstream side. However, the cross-sectional shape of the spacer 20 is changed in the cooling water circulation direction (cooling water flow direction) so that the contact area (represented by “height” H) of the main cooling passage 18 with the cylinder bore wall increases toward the downstream side. I'm allowed.

  1 correspond to the upstream portion, the midstream portion, and the downstream portion, respectively, in the cooling water flow direction, and the cross sections of the A, B, and C portions in FIG. 1 are shown in FIG. , (B), (C). In FIG. 2, passage sectional areas SA, SB, and SC are passage sectional areas of the main cooling passage 18 at portions A, B, and C in FIG. 1, and VwA, VwB, and VwC are respectively shown in FIG. 1 is the flow rate of the engine cooling water in the main cooling passage 18 at the parts A, B, and C, and vA, vB, and vC are the engine cooling water in the main cooling passage 18 at the parts A, B, and C in FIG. Flow rate.

The above-mentioned condition that “the passage cross-sectional area S of the main cooling passage 18 of the upper portion 11 of the water jacket 11 is not widened on the downstream side” is SA ≧ SB ≧ SC. The flow velocities that have the greatest effect on the current are made substantially the same, ie, vA≈vB≈vC.
In addition, the condition that “the contact area of the main cooling passage 18 with the cylinder bore wall increases toward the downstream side” is that HA <HB <HC. Thus, the cylinder bore wall increases toward the downstream side. (4) The cooling effect is increased so that the engine cooling water temperature increases toward the downstream side, and the cylinder bore wall cooling effect is reduced.

  When the cross-sectional shape of the spacer 20 is changed in the cooling water circulation direction (cooling water flow direction), the spacer is set so that the flow speed of the engine cooling water is approximately the same before and after the water hole and / or the air vent hole 9 of the cylinder head gasket. It is desirable to change the sectional shape of 20 in a stepwise manner before and after the water hole and / or the air vent hole 9 in the cooling water flow direction.

The operation and effect of the first embodiment of the present invention will be described.
Since the cross sectional area S of the main cooling passage 18 at the upper part of the water jacket is not widened on the downstream side, the cross sectional shape of the spacer 20 is changed in the cooling water circulation direction, so that the flow velocity that most affects the heat transfer coefficient α. v can be made substantially the same in the cooling water flow direction, that is, vA≈vB≈vC. As a result, even if the engine coolant flows into the water jacket in the cylinder head through the water hole and / or the air vent hole 9, the cylinder bore wall 4 is not insufficiently cooled on the coolant outlet side of the water jacket 10.

  Further, the temperature of the cooling water rises toward the downstream, the temperature difference between the cylinder bore wall 4 and the engine cooling water becomes small, and the amount of heat Q = αA (Tb−Tw) transferred (stolen) from the cylinder bore wall to the engine cooling water. (Tb−Tw) decreases and Q decreases, but the contact area A (proportional to the contact area height H) of the main cooling passage 18 with the cylinder bore wall increases toward the downstream side (HA < HB <HC), the amount of decrease in the temperature difference (Tb−Tw) between the bore wall and the cooling water becomes smaller, and the amount of contact area between the cooling passage and the cylinder bore wall increases toward the downstream side (HA <HB <HC). ), And there is no insufficient cooling of the cylinder bore wall 4 on the cooling water outlet side. Conventionally, it was necessary when there was insufficient cooling on the outlet side (necessary to suppress the increase in Tw on the downstream side). Therefore, overcooling at the cooling water inlet side is not generated.

Further, since the cross-sectional shape of the spacer 20 is changed stepwise in the cooling water flow direction before and after the water hole and / or the air vent hole 9, the engine that has been generated stepwise before and after the water hole and / or the air vent hole 9. A change in the flow rate v of the cooling water can be accommodated, and the flow rate v of the engine cooling water before and after the water hole and / or the air vent hole 9 and thus the heat transfer coefficient α can be maintained substantially constant. This also makes it possible to reduce the cylinder bore wall temperature difference between the cylinders.
[Example 2]
In the cylinder block cooling structure 1 according to the second embodiment of the present invention, as shown in FIG. 3B, the spacer 20 has an introduction portion (an engine cooling water inlet 7, a water pump W to the water jacket 10). Cylinder bore wall that suppresses the sneaking of engine cooling water to the cylinder bore wall 4 side ((b) in FIG. 3 shows the wrapping of cooling water in the conventional structure) in the vicinity of the portion where the cooling water flows from / P) 4 is provided with a spacer extension portion 24 ("spacer extension portion for suppressing wraparound", a portion longer in the vertical direction than the spacer in FIG. 3A) in FIG. Yes.
The spacer extension 24 may be provided in the circumferential direction of the cylinder bore wall 4 at about 1/4 of the circumferential length of the cylinder bore wall 4 on the most upstream side. In that case, the center of the spacer extension 24 in the circumferential direction of the arc is positioned at the engine coolant inlet 7 site.

As for the operation and effect of the second embodiment of the present invention, the spacer 20 is provided with the spacer extension 24 extending in the vertical direction along the cylinder bore wall in the vicinity of the introduction portion of the cooling water to the water jacket. It is possible to suppress the sneaking of water to the cylinder bore wall 4 side, the cylinder bore wall 4 facing the engine cooling water inlet 7 is not cooled intensively, and the uniform cylinder wall temperature between the cylinders is further improved. I can be taken.
Example 3
In the cylinder block cooling structure 1 according to the third embodiment of the present invention, as shown in FIG. 4, the spacer 20 has an introduction portion (from the engine cooling water inlet 7 and the water pump W / P to the water jacket 10 to the cooling water jacket 10). A spacer extension 24 extending in the vertical direction along the cylinder bore wall 4 is provided in the vicinity of the portion where the cooling water flows in, and the engine cooling water is prevented from entering the cylinder bore wall 4 side. A flange 25 is provided that is bent from the upper and lower ends in a direction perpendicular to the spacer extension 24 and extends to the cylinder bore wall 4.
The spacer extension 24 and the flange 25 may be provided in the circumferential direction of the cylinder bore wall 4 at about ¼ of the circumferential length of the cylinder bore wall 4 on the most upstream side. In that case, the circumferential center of the circular arc of the spacer extension 24 and the flange 25 is set to the engine coolant inlet 7 site.

Regarding the operation and effect of the third embodiment of the present invention, the spacer 20 is provided with a spacer extension 24 extending in the vertical direction along the cylinder bore wall in the vicinity of the introduction portion of the cooling water into the water jacket. Since the flange 25 is provided at 24, the engine coolant can be prevented from wrapping around the cylinder bore wall 4 side (the wraparound can be further suppressed as compared with the second embodiment of the present invention), and the engine coolant inlet The cylinder bore wall 4 facing the cylinder 7 is not cooled intensively, and the cylinder wall temperature between the cylinders can be made even more uniform.
Example 4
In the cylinder block cooling structure 1 according to the fourth embodiment of the present invention, as shown in FIG. 5, the spacer 20 has an introduction portion (from the engine cooling water inlet 7 and the water pump W / P to the water jacket 10 to the cooling water). A spacer extension 24 extending in the vertical direction along the cylinder bore wall 4 is provided in the vicinity of the portion where the cooling water flows in, and the engine cooling water is prevented from entering the cylinder bore wall 4 side. At least one of the upper and lower end portions is provided with a wraparound suppressing member 40 that suppresses wrapping of the cooling water toward the cylinder bore wall.
The wraparound restraining member 40 may contact the cylinder bore wall 4 or the water jacket bottom wall or the cylinder head gasket. When the squeezing suppression member 40 comes into contact with the cylinder bore wall 4 or the water jacket bottom wall or the cylinder head gasket, the squeezing suppression member 40 is preferably made of an elastic member such as a sponge, and the sneaking suppression member 40 interferes with the cylinder bore wall 4 or the like. Even so, the wraparound suppressing member 40 is deformed, and the wraparound of the cooling water can be suppressed without impeding the insertability into the water jacket 10. Moreover, the heat | fever damage from the water jacket inner wall 4 of the resin spacer can be prevented by using the wraparound suppressing member 40 as a heat insulating material.
The spacer extension 24 and the sneaking-in suppressing member 40 may be provided in the circumferential direction of the cylinder bore wall 4 at about ¼ of the circumferential length of the cylinder bore wall 4 on the most upstream side. In that case, the circumferential direction center of the circular arc of the spacer extension part 24 and the sneaking-in suppression member 40 is made to come to the engine coolant inlet 7 site.

Regarding the operation and effect of the fourth embodiment of the present invention, the spacer 20 is provided with a spacer extension 24 extending in the vertical direction along the cylinder bore wall in the vicinity of the introduction portion of the cooling water into the water jacket. Since the sneaking suppression member 40 is provided at 24, the sneaking of the engine cooling water toward the cylinder bore wall 4 can be suppressed (the sneaking can be further suppressed as compared with the second embodiment of the present invention), and the engine cooling can be performed. The cylinder bore wall 4 facing the water inlet 7 is not cooled intensively, and the cylinder wall temperature between cylinders can be made even more uniform.
Example 5
In the cylinder block cooling structure 1 according to the fifth embodiment of the present invention, as shown in FIGS. 6 to 8, a portion of the spacer 20 that faces the cylinder bore wall 4 of the cylinder bore 3 at the end of the cylinder bore row in the cylinder bore row direction ( There are two locations on the upstream side and the downstream side, but at least one of them extends the vertical direction along the cylinder bore wall 4 to suppress cooling of the cylinder bore wall 4 from the cylinder bore row direction (for overcooling suppression) Spacer extension portion).
The spacer extension 26 for suppressing overcooling provided to face the cylinder bore wall 4 on the most upstream side may also serve as the spacer extension 24 for suppressing wraparound.
The spacer extension 26 for suppressing overcooling may be provided in the circumferential direction of the cylinder bore wall 4 at about 1/4 of the circumference of the cylinder bore wall 4 on the most upstream side. In that case, the circumferential direction center of the circular arc of the spacer extension 26 is set to the engine coolant inlet 7 site.

The operation and effect of the fifth embodiment of the present invention are as follows.
The cylinder bores on the cooling water inlet 7 and cooling water outlet 8 side of the cylinder bore row are cooled not only from the left and right surfaces perpendicular to the longitudinal direction of the cylinder block but also from one surface in the longitudinal direction of the cylinder block. The cylinder bore is cooled more strongly than the cylinder bore in the center, and a temperature difference between the cylinders is likely to occur. However, in the structure of the fifth embodiment of the present invention, the cylinder bore that suppresses the cooling of the cylinder bore wall from the cylinder bore row direction at the portion of the spacer 20 that faces the cylinder bore wall of the cylinder bore at the end of the cylinder bore row in the cylinder bore row direction. Since the spacer extension 26 extending in the vertical direction along the wall is provided, overcooling of the cylinder bore at the end of the cylinder bore row can be suppressed, which can contribute to uniforming of the inter-cylinder bore wall temperature.

It is a top view of the cooling structure of the cylinder block of Example 1 of this invention. It is sectional drawing of the cooling structure of the cylinder block of Example 1 of this invention, (A), (B), (C) is sectional drawing of A, B, and C site | part of FIG. 1, respectively. (A) is sectional drawing of the cooling structure of the conventional cylinder block, (b) is sectional drawing of the cooling structure of the cylinder block of Example 2 of this invention. It is sectional drawing of the cooling structure of the cylinder block of Example 3 of this invention. It is sectional drawing of the cooling structure of the cylinder block of Example 4 of this invention. It is a top view of the cooling structure of the cylinder block of Example 5 of this invention. It is sectional drawing of the cooling structure of the cylinder block of Example 5 of this invention, and is sectional drawing of the site | part corresponding to A site | part of FIG. It is sectional drawing of the cooling structure of the cylinder block of Example 5 of this invention, and is sectional drawing of the site | part corresponding to B site | part of FIG.

Explanation of symbols

1 Cylinder block cooling structure 2 Cylinder block 3 Cylinder bore 4 Water jacket inner wall (cylinder bore wall)
5 Water jacket outer wall 6 Water jacket bottom wall 7 Engine cooling water inlet 8 Engine cooling water outlet 9 Water hole and / or air vent hole 10 Water jacket 11 (Water jacket) upper part 12 (Water jacket) Lower part 13 (Water jacket outer part) ) Intermediate portion 14, 15 Flow path 16, 17 Merge portion 18 Main cooling passage 20 Spacer 24 Extension portion 25 (for suppressing wraparound) 26 庇 26 Extension portion (for suppressing overcooling) 40 Rotation suppression member

Claims (6)

  A cooling structure of a cylinder block in which a spacer is arranged in a water jacket of the cylinder block, wherein the cross-sectional area of the main cooling passage at the upper part of the water jacket is not widened on the downstream side, while the main cooling passage A cooling structure for a cylinder block in which the cross-sectional shape of the spacer is changed in the direction of circulating coolant so that the contact area with the cylinder bore wall increases toward the downstream side.   The cylinder block cooling structure according to claim 1, wherein the cross-sectional shape of the spacer is changed stepwise before and after the water hole in the cooling water flow direction so that the flow velocity is substantially the same before and after the gasket water hole.   A cylinder block cooling structure in which a spacer is arranged in the water jacket of the cylinder block, and the cylinder bore is configured to suppress the wrapping of cooling water to the cylinder bore wall side in the vicinity of the introduction portion of the cooling water to the water jacket. A cooling structure of a cylinder block provided with a spacer extension extending in the vertical direction along the wall.   4. The cooling structure for a cylinder block according to claim 3, wherein a flange extending from the spacer extension is provided on the spacer extension.   4. The cooling structure for a cylinder block according to claim 3, wherein a wraparound suppressing member that suppresses the wrapping of cooling water to the cylinder bore wall side is provided at the spacer extension.   Cylinder block cooling structure in which a spacer is arranged in the water jacket of the cylinder block, and the cylinder bore wall from the cylinder bore row direction is formed at a portion of the spacer facing the cylinder bore wall of the cylinder bore at the end of the cylinder bore row in the cylinder bore row direction. The cooling structure of the cylinder block which provided the spacer extension part extended in an up-down direction along the cylinder bore wall which suppresses cooling of.

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