JP7347755B2 - Engine cooling structure - Google Patents

Description

The present invention relates to an engine cooling structure in which a water jacket spacer for controlling the flow of cooling water is disposed within a water jacket.

BACKGROUND ART A water jacket, which serves as a flow path for cooling water, is provided in a cylinder block of a multi-cylinder engine (internal combustion engine) so as to surround a plurality of cylinders (cylinder rows). A water jacket spacer is placed inside the water jacket to control the flow of cooling water in order to set the cylinder to a target temperature.

The water jacket spacer has a cylindrical shape in which parts corresponding to each cylinder are connected, and is generally integrally molded as a whole. However, in recent years, from the standpoint of ensuring functionality and production, water jacket spacers with a split structure consisting of two mutually independent parts have also been seen, for example, as disclosed in Patent Document 1. The water jacket spacer disclosed in Patent Document 1 has a configuration in which it is divided at both end portions in the cylinder row direction.

Japanese Patent Application Publication No. 2018-131963

In the engine disclosed in Cited Document 1, a cooling water supply port is provided at one end portion of the cylinder block in the cylinder row direction, and the following problems can be considered. That is, in this engine, the water pressure of the cooling water supplied to the water jacket through the cooling water supply port acts near the connecting part of the two parts that constitute the water jacket spacer, and the water pressure creates a gap between the two parts. It is conceivable that a gap is formed and cooling water flows into the inside of the water jacket spacer. In such a case, the targeted water flow cannot be obtained within the water jacket, which may affect the cooling effect of the cylinder. Such a phenomenon becomes particularly noticeable when the water pump is disposed near the cooling water supply port.

Therefore, when a water jacket is equipped with a water jacket spacer having a split structure, measures are required to avoid such inconvenience, but Patent Document 1 does not disclose or suggest anything regarding this point. I can't do it.

The present invention has been made in view of the above-mentioned circumstances, and is directed to an engine in which a water jacket spacer having a split structure is provided in the water jacket, in which an unintended water flow is formed inside the water jacket spacer. The aim is to provide technology that can suppress this.

In order to solve the above problems, the present invention provides a cylinder block including a cylinder row in which a plurality of cylinders are arranged in a line in a predetermined direction, and a water jacket formed to surround this cylinder row. an engine cooling structure comprising: a water jacket spacer having a cylindrical shape surrounding the cylinder row and disposed within the water jacket to control the flow of cooling water; is divided into one end and the other end in the cylinder row direction, and has a first end that is connected to each other at the one end and a second end that is connected to each other at the other end. The cylinder block is provided with a supply port for supplying a cooling liquid into the water jacket at a position corresponding to the one end of the water jacket spacer, and the cylinder block is provided with a supply port for supplying cooling liquid into the water jacket at a position corresponding to the one end of the water jacket spacer. Among the second end portions, only the first end portions overlap each other over a range longer than the length of the supply port in the cylinder axial direction.

According to this cooling structure, the first ends of the water jacket spacer overlap each other over a range longer than the length of the supply port, so that the water pressure of the cooling water supplied from the supply port is applied to the first end of the water jacket spacer. Even when acting on one end, both ends are difficult to separate or deform. In other words, it is difficult for a gap to be formed between both end portions. Therefore, it is possible to prevent the formation of the gap and the formation of an unintended water flow inside the water jacket spacer. Further, according to this structure, a rational structure is achieved in which only the first end portions, in which gaps are likely to be formed due to the water pressure of the cooling water, overlap each other among the first and second end portions.

In particular, when the engine is equipped with a water pump that is attached to the cylinder block on the same side as the one end of the water jacket spacer in the cylinder row direction and pumps cooling water toward the supply port, Since the water pressure of the cooling water supplied from the mouth becomes relatively high, there is a concern that the gap may be formed between the two first ends. However, according to the above structure in which the first end portions overlap each other, formation of a gap between the two first end portions is effectively suppressed.

In each of the cooling structures described above, each of the first end portions of the water jacket spacer is provided with a regulating portion that restricts relative displacement of each of the first end portions by engaging with each other. suitable.

According to this structure, it becomes more difficult for the first end portions to separate from each other, so that the formation of a gap between the two end portions due to the water pressure of the cooling water is suppressed to a higher degree.

In this cooling structure, it is preferable that the respective first end portions overlap each other in a cylinder axial direction other than the restriction portion.

According to this configuration, the parts other than the regulating part of each first end part, that is, the parts that are particularly easy to separate when receiving the water pressure of cooling water, overlap, so that both first ends can be arranged in a rational structure. It becomes possible to suppress the formation of gaps between the parts.

In this cooling structure, the water jacket has a shape in which the flow passage width gradually narrows from the cylinder head side toward the opposite cylinder head side in the cylinder block, and the regulating portion is arranged at each of the first end portions. Among them, the water jacket spacer is provided at a position that is biased toward the cylinder head side with respect to the middle part of the water jacket spacer in the cylinder axis direction.

According to this configuration, the regulating portion is located in a portion of the water jacket where there is sufficient space, so that the regulating portion is less likely to be subject to structural restrictions. Therefore, it becomes possible to provide a regulating portion that can more reliably regulate the relative displacement of each first end portion with a margin. Furthermore, since the first end portions overlap each other in the region on the side opposite to the cylinder head among the first end portions, it is also suppressed that a gap is formed in the region due to the water pressure of the cooling water.

In each of the cooling structures described above, it is preferable that an expansion member is provided at a position corresponding to the supply port on the inner wall surface of the water jacket spacer.

According to this structure, both first end portions are difficult to be displaced by the expansion pressure of the expansion member interposed between the cylinder bore wall and the water jacket spacer. Therefore, formation of a gap between the first end portions due to the water pressure of the cooling water is more reliably suppressed.

In addition, when the supply ports are provided at symmetrical positions with the cylinder axis as a border in the orthogonal direction perpendicular to both the cylinder row direction and the cylinder axis direction, these ports are provided at both first end portions. Water pressure acts to separate them. Therefore, each of the cooling structures described above is particularly useful when the supply ports are provided at symmetrical positions with respect to the cylinder axis in the orthogonal direction.

As explained above, according to the engine cooling structure of the present invention, in an engine equipped with a water jacket spacer having a split structure, it is possible to suppress the formation of unintended water flow inside the water jacket spacer. becomes possible.

FIG. 1 is a front view of an engine to which a cooling structure according to the present invention is applied. It is an exploded perspective view showing a cylinder block and a water jacket spacer together. FIG. 3 is a front view of the cylinder block alone (viewed from the -X side). FIG. 3 is a cross-sectional view of the cylinder block in the YZ plane (a cross-sectional view taken along line IV-IV in FIG. 2). FIG. 3 is a perspective view of the water jacket spacer viewed from one end side (-X side) in the cylinder row direction. FIG. 2 is an exploded perspective view of the water jacket spacer viewed from one end side (−X side) in the cylinder row direction. It is an exploded perspective view of the water jacket spacer seen from the other end side (+X side) in the cylinder row direction. FIG. 3 is an exploded perspective view of the main parts of the water jacket spacer showing the configuration of the first connecting portion. FIG. 3 is a front view of the water jacket spacer (a front view seen from the -X side). FIG. 9 is a cross-sectional view (cross-sectional view taken along line XX in FIG. 9) of the water jacket spacer. FIG. 9 is a cross-sectional view of the water jacket spacer (cross-sectional view taken along the line XI-XI in FIG. 9). FIG. 9 is a cross-sectional view of the water jacket spacer (cross-sectional view taken along the line XII-XII in FIG. 9). FIG. 9 is a cross-sectional view of the water jacket spacer (cross-sectional view taken along line XIII-XIII in FIG. 9). FIG. 3 is an exploded perspective view of a main part of the water jacket spacer showing the configuration of a second connecting portion.

Hereinafter, one preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[Overall engine configuration]
FIG. 1 is a front view of an engine 1 to which a cooling structure according to the present invention is applied. The engine 1 is an engine mounted on a vehicle as a driving power source, and is, for example, a four-cycle multi-cylinder diesel engine.

The engine 1 includes a cylinder block 2 having a plurality of cylinders (cylinder bores) therein, a cylinder head 3 attached to the top surface of the cylinder block 2, and a piston 4 (FIG. 4) housed in the cylinder. The engine body 10 includes an engine body 10. The engine 1 is installed in a vehicle vertically or horizontally. In the case of vertical installation, in the directions shown in FIG. 1, the Y direction is the left-right direction corresponding to the vehicle width direction, and the Z direction is the up-down direction (+Z=up, -Z=down).

The engine 1 includes a water pump 11 for forcibly circulating cooling water (coolant) within the engine body 10. The water pump 11 is an impeller type pump equipped with an impeller that pumps cooling water. The water pump 11 is driven by the driving force generated by the engine body 10. That is, the driving force of the crankshaft is transmitted to the water pump 11 via a crank pulley 12 attached to the crankshaft of the engine body 10 and a stretch belt 13 stretched around the crank pulley 12.

FIG. 1 shows a cooling water inlet port section 14 that introduces cooling water into the engine body 10, and a cooling water outlet port section 16 that serves as an outlet of the cooling water after passing through the circulation path of the cooling water inside the engine body 10. is shown. The coolant inlet port section 14 and the coolant outlet port section 16 are composed of piping members attached to the engine body 10. The water pump 11 is incorporated in the middle of the distribution channel. In addition to the above-mentioned distribution path within the engine body 10, the cooling water circulates through a circulation path that passes through a heater unit (not shown), a radiator for heat radiation, and the like.

[Engine (cylinder block) cooling structure]
FIG. 2 is an exploded perspective view showing the flow path of the cylinder block 2 among the cooling water flow paths in the engine body 10. A jacket spacer 5 is shown. Further, FIG. 3 is a front view of the cylinder block 2 alone.

As shown in FIG. 2, the cylinder block 2 includes a cylinder row 21L in which six cylinders (cylinder bores) 21 are arranged in a row in the X direction (predetermined direction), and is arranged to surround this cylinder row 21L. A water jacket 22 consisting of a groove is provided. Note that the X direction is the longitudinal direction of the vehicle when the engine 1 is placed vertically. Water jacket spacer 5 is arranged inside water jacket 22.

The cylinder block 2 is a substantially rectangular parallelepiped block that is long in the X direction. A water pump 11 is attached to the −X side side of the cylinder block 2, and as shown in FIG. ) is provided. Each block side inlet 15 communicates with the cooling water inlet port section 14 shown in FIG. 1 via the water pump 11. That is, the cooling water enters the cylinder block 2 from the cooling water inlet port portion 14, and enters the water jacket 22 from each block side inlet 15 due to the pumping force of the water pump 11. As shown by arrow FL in FIG. 2, the cooling water flows through the water jacket 22 from the −X side surface to the +X side surface of the cylinder block 2. That is, the water jacket 22 is a flow path that allows cooling water to flow from one end (-X side) to the other end (+X side) of the cylinder row 21L.

The cylinder head 3 is attached to the upper surface (+Z surface) of the cylinder block 2 so as to close the upper surface opening of each cylinder 21 in the cylinder row 21L. The cylinder head 3 is provided with an intake port and an intake valve that supply intake air to each cylinder 21, and an exhaust port and an exhaust valve that discharge combustion gas from each cylinder 21.

In FIG. 2, with respect to the arrangement line (line in the X direction) of the cylinder row 21L, the side where the intake valves are arranged is the "intake side", and the side where the exhaust valves are arranged is the "exhaust side". is indicated. The water jacket 22 includes an intake side jacket 22IN arranged on the intake side of the cylinder row 21L, and an exhaust side jacket 22EX arranged on the exhaust side.

As shown in FIG. 3, the two block-side inlets 15 formed on the side surface of the cylinder block 2 on the -X side are provided at symmetrical positions with respect to the cylinder axis 21X (virtual central axis of the cylinder 21). ing. As a result, the cooling water is divided almost equally into the intake side jacket 22IN and the exhaust side jacket 22EX, and flows through the water jacket 22.

The cylinder block 2 includes a cylindrical inner block (referred to as a cylinder bore wall 23) that partitions each cylinder 21, and an outer block 24 provided so as to surround the cylinder bore wall 23. Cylinder bore walls 23 that partition adjacent cylinders 21 are integrally connected to each other, and therefore, the cylinder block 2 can be said to be a cylinder block equipped with a Siamese-type cylinder row 21L. A cylinder liner 26 (FIG. 4), which serves as an inner surface on which the piston 4 actually slides, is arranged on the cylinder bore wall 23 that partitions each cylinder 21.

The inner wall surface of the water jacket 22 consists of the outer wall surface of the cylinder bore wall 23, and the outer wall surface of the water jacket 22 consists of the inner wall surface of the outer block 24. That is, the space between the outer wall surface of the cylinder bore wall 23 and the inner wall surface of the outer block 24 is a space of the water jacket 22 through which cooling water flows.

The thickness of the cylinder bore wall 23 is substantially constant except for a portion of the inter-bore wall 25, which is a wall between adjacent cylinders 21. Therefore, the outer wall surface of the cylinder bore wall 23 has an uneven curved shape that follows the contours of the six cylinders 21 lined up in the X direction when viewed from above. That is, the outer wall surface has a concave curved surface that is concave inward near the region of the inter-bore wall 25, and a convex curved surface that bulges outward in the region between the pair of inter-bore walls 25. The inner wall surface of the outer block 24 also has an uneven curved surface shape corresponding to the uneven curved surface shape of the outer wall surface of the cylinder bore wall 23. Therefore, in the extending direction (X direction) of the water jacket 22, the gap between the outer wall surface of the cylinder bore wall 23 and the inner wall surface of the outer block 24 (the groove width of the water jacket 22) is approximately constant. Therefore, the water jacket 22 has a shape corresponding to the uneven curved surface shape when viewed from above, and the water jacket spacer 5 also has a shape corresponding to this uneven curved surface shape.

FIG. 4 is a cross-sectional view of the cylinder block 2 along the YZ plane, and specifically, a cross-sectional view taken along the line IV--IV in FIG.

As shown in FIG. 4, the water jacket 22 has a U-shaped groove shape elongated in the vertical direction (Z direction), and the flow path width (width in the Y direction) is from the cylinder head 3 side to the opposite cylinder. It is formed to become gradually narrower toward the head 3 side.

The water jacket spacer 5 is formed in a cylindrical shape surrounding the cylinder bore wall 23 (cylinder row 21L) when viewed from above. As shown in FIG. 4, the water jacket spacer 5 is inserted into the space of the water jacket 22, and divides the cooling water flow path into two regions: a bore side path 22A and an anti-bore side path 22B. The bore side route 22A is a route closer to the cylinder 21 in the radial direction of the cylinder 21. The anti-bore side path 22B is located outside the bore side path 22A and is a path far from the cylinder 21.

The water jacket spacer 5 serves to control the flow of cooling water within the water jacket 22. For example, the water jacket spacer 5 divides the flow of cooling water within the water jacket 22 so that the main flow of cooling water is formed in the anti-bore side path 22B. In other words, the water jacket spacer 5 is designed to actively form a water flow (form a main stream) of cooling water in the anti-bore side path 22B, while not actively forming a water flow in the bore side path 22A. control. This prevents the cylinder 21 from becoming too cold and causing cooling loss.

[Detailed structure of water jacket spacer]
FIG. 5 is a perspective view of the water jacket spacer 5. The water jacket spacer 5 is made of synthetic resin and has a cylindrical shape that can surround the cylinder row 21L. The water jacket spacer 5 has an upper end flange 31 at its upper end (+Z end) and a lower end flange 32 at its lower end (−Z end). These flanges 31 and 32 contribute to maintaining the posture of the water jacket spacer 5 within the water jacket 22, forming a desired water flow, and the like. A notch portion 33 is provided at the downstream end of the upper end flange 31 in the cooling water flow direction indicated by the arrow FL. Cooling water is guided to the water jacket inside the cylinder head 3 through this notch 33 .

An upper end protrusion 31a that projects upward from the upper end flange 31 is provided at the upper end of the water jacket spacer 5 at a position corresponding to each bore wall 25 of the cylinder row 21L. Furthermore, a lower end protrusion 32a (FIGS. 6 and 7) projecting downward from the lower end flange 32 is provided at the lower end of the water jacket spacer 5 at a position corresponding to each bore wall 25 of the cylinder row 21L. . The upper end protrusion 31a abuts from below an unillustrated gasket interposed between the cylinder block 2 and the cylinder head 3, and the lower end protrusion 32a abuts on the inner bottom surface of the water jacket 22. Thereby, as shown in FIG. 4, the water jacket spacer 5 is positioned in the vertical direction (Z direction) within the water jacket 22.

The water jacket spacer 5 further includes an expansion member 36 on its inner peripheral surface. Specifically, the expansion member 36 is provided in a region below the vertically intermediate portion of the water jacket spacer 5 over almost the entire circumference except for the positions of the connecting portions 5A and 5B, which will be described later.

The expansion member 36 expands due to an external factor, and positions the water jacket spacer 5 in the space of the water jacket 22 in the cylinder row direction (X direction) and in the width direction (Y direction) perpendicular to the cylinder row direction. In this example, the expansion member 36 is made of cellulose sponge, is in a contracted state when the engine is assembled, and expands when cooling water infiltrates (external factor). Due to this expansion, the water jacket spacer 5 is pressed and positioned against the inner wall surface of the outer block 24 via the lower end flange 32. As a result, as shown in FIG. A gap between the outer peripheral surface of the jacket spacer 5 and the inner wall surface of the outer block 24 is set to a predetermined dimension. In this example, by positioning the water jacket spacer 5 so that d2>d1, a water flow of cooling water is actively formed (a mainstream is formed) in the anti-bore side path 22B, as described above. As the expansion member 36, in addition to a member that expands due to infiltration of cooling water as in this example, it is also possible to use a member that expands in response to heat (external factors).

6 is an exploded perspective view of the water jacket spacer 5 viewed from one end side (-X side) in the cylinder row direction (X direction), and FIG. 7 is an exploded perspective view of the water jacket spacer 5 viewed from the other end side (+X side) in the cylinder row direction. 5 is an exploded perspective view of the water jacket spacer 5. FIG.

As shown in FIGS. 6 and 7, the water jacket spacer 5 has a half-split structure (divided structure) along the line in the cylinder row direction (X direction), and includes an intake side spacer 5IN on the +Y side, -Y side exhaust side spacer 5EX. The intake side spacer 5IN is a portion disposed within the intake side jacket 22IN of the water jacket 22, and the exhaust side spacer 5EX is a portion disposed within the exhaust side jacket 22EX.

The intake side spacer 5IN and the exhaust side spacer 5EX are integrated by connecting one end (−X end) and the other end (+X end) to each other in the cylinder row direction. That is, the water jacket spacer 5 has connecting portions (first connecting portion 5A, second connecting portion 5B) between the intake side spacer 5IN and the exhaust side spacer 5EX at one end and the other end in the cylinder row direction.

The first connecting portion 5A is a portion where an end portion 41A on one end side (−X side) of the intake side spacer 5IN and an end portion 42A on one end side (−X side) of the exhaust side spacer 5EX are connected. The first connecting portion 5A connects the intake side spacer 5IN and the exhaust side spacer 5EX, and in this connected state, the cylinder row direction (X direction), the vertical direction (cylinder axial direction/Z direction), and the cylinder A regulating portion is provided to regulate relative displacement of the end portions 41A and 42A in the width direction (Y direction) that is orthogonal to both the row direction and the vertical direction. Specifically, the first connecting portion 5A includes a first upper regulating portion 51A that regulates the relative displacement of the end portions 41A, 42A in the cylinder row direction, and a first upper regulating portion 51A that regulates the relative displacement of the end portions 41A, 42A in the vertical direction and width direction. and a first lower regulating portion 52A that regulates. In this embodiment, the end portions 41A and 42A correspond to the “end portion” and the “first end portion” according to the present invention, and the first upper restriction portion 51A and the first lower restriction portion 52A correspond to the “end portion” and the “first end portion” according to the present invention. This corresponds to the “Regulatory Department.”

FIG. 8 is an exploded perspective view of a main part of the water jacket spacer 5 showing the first connecting portion 5A, and FIG. 9 is a front view of the water jacket spacer 5 (a front view seen from the -X side). 10 to 13 are cross-sectional views of the water jacket spacer 5 on the XY plane, and specifically, the lines XX, XI-XI, XII-XII, and It is a sectional view along the line. Note that the expansion member 36 is not shown in FIGS. 10 to 13.

The first upper restricting portion 51A and the first lower restricting portion 52A are provided above a substantially intermediate portion of the water jacket spacer 5 in the vertical direction (Z direction), that is, at a position biased toward the cylinder head 3 side. The first upper regulating portion 51A is provided at the upper end portion of the water jacket spacer 5, and the first lower regulating portion 52A is provided adjacent to the lower side of the first upper regulating portion 51A.

As shown in FIG. 8, the first upper regulating portion 51A is provided along a plate-shaped protrusion 55 extending in the −Y direction from the end portion 41A of the intake spacer 5IN and an outer wall surface 501 of the exhaust spacer 5EX. and a regulating wall portion 56.

The plate-shaped projecting piece 55 has a rectangular shape with a short side in the Z direction and a long side in the Y direction, and extends slightly from the end portion 41A of the intake side spacer 5IN so as to be in contact with the outer wall surface 501 of the exhaust side spacer 5EX. It is provided offset to the outside (-X side) and has a slightly curved shape as a whole. On the other hand, the regulating wall portion 56 is provided with a gap equal to the thickness of the plate-shaped protrusion 55 between the regulating wall portion 56 and the outer wall surface 501 . The regulating wall portion 56 is also curved along the outer wall surface 501. The regulating wall portion 56 is provided upright on the upper surface of a protruding portion 64 (described later) provided on the outer wall surface 501, and is provided on the vertical wall portion 502 that connects the protruding portion 64, the outer wall surface 501, and the upper end flange 31. It is connected.

With this configuration, when the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX are brought together, a part of the plate-shaped protrusion 55 is attached to the exhaust side spacer 5EX, as shown in FIGS. 9 and 10. It is fitted between the outer wall surface 501 and the regulating wall portion 56 of 5EX. In this state, the plate-shaped projecting piece 55 is restrained from both sides in the X direction by the outer wall surface 501 and the regulating wall part 56. This restricts the relative displacement of the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX in the cylinder row direction (X direction).

As shown in FIG. 8, the first lower regulating portion 52A includes an engaging piece portion 62 extending in the −Y direction from the end portion 41A of the intake spacer 5IN, and a cover provided on the outer wall surface 501 of the exhaust side spacer 5EX. The engaging portion 63 is included.

The engagement piece 62 is a generally rectangular plate-shaped protrusion with a claw part 62a at the tip (-Y end), and like the plate-shaped protrusion 55, it extends from the distal end 41A of the intake side spacer 5IN. It is provided slightly offset to the outside (-X side). A pair of upper and lower recesses 62b are formed in the upper and lower edges (+Z side edge and −Z side edge) of the engagement piece portion 62, respectively. As a result, the portion between the distal end and the proximal end of the engagement piece portion 62 has a constricted shape.

The engaged portion 63 includes a pair of upper and lower protrusions 64 extending parallel to each other from the end portion 42A of the exhaust side spacer 5EX toward the -Y side. The spacing between these protruding stripes 64 (the spacing in the Z direction) is set to be approximately equal to or slightly wider than the vertical width (width in the Z direction) of the engagement piece portion 62. Engagement protrusions 65 are provided on opposing surfaces of the respective protrusions 64 so as to protrude from each other. Each engagement convex portion 65 is formed with a slope 65a that is inclined from the +Y side to the -Y side and gradually extends toward the -X side. Furthermore, an extending portion 66 extending in the Z direction from the opposing surface of each engagement convex portion 65 is connected to an end portion on the −Y side of the opposing surface.

With this configuration, when the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX are brought into contact with each other, the engaging piece portion 62 is inserted between the both protrusions 64 of the engaged portion 63. At the same time, the engaging piece 62 is guided along the slope 65a and deflects toward the −X side. Then, the claw portion 62a rides over each of the engagement convex portions 65 and the engagement piece portion 62 elastically returns, so that the engagement piece portion 62 passes through the engagement convex portion 65 and the extension portion 66 via the claw portion 62a. At the same time, each engagement convex portion 65 is interposed in each concave portion 62b of the engagement piece portion 62.

In this state, as shown in FIGS. 9, 11, and 12, the engagement piece portion 62 is engaged with the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX. It engages with the convex portion 65 and the extending portion 66 . Therefore, relative displacement in the width direction (Y direction) between the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX is restricted. In this case, the interposition of the engagement protrusion 65 in the recess 62b of the engagement piece 62 enhances the effect of regulating relative displacement in the width direction. In addition, each of the protrusions 64 comes into contact with the engagement piece 62 from both the upper and lower sides (both sides in the Z direction), so that the engagement piece 62 is restrained from both the upper and lower sides. Therefore, relative displacement in the vertical direction (Z direction) between the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX is restricted.

As shown in FIG. 5, FIG. 8, and FIG. An overlapping portion 70 is provided in which the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX overlap each other. Specifically, the end portion 42A of the exhaust side spacer 5EX is provided with a plate-shaped extension portion 72 that further protrudes in the +Y direction from the abutment position of both end portions 41A and 42A and extends in the vertical direction, while the intake side spacer A step portion 71 having a shape corresponding to the extension portion 72 is provided at the end portion 41A of the 5IN.

With this configuration, when the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX are brought into contact with each other, as shown in FIG. , 42A are connected without any gaps.

In this example, as shown in FIG. 9, the two block-side inlets 15 for introducing cooling water into the water jacket 22 are positioned below the first upper regulating part 51A and the first lower regulating part 52A. and faces the -X side end of the water jacket spacer 5. Moreover, these cooling water inlets 14 are located near the water pump 11, and as described above, are provided at positions that are symmetrical to each other with the cylinder axis 21X as a boundary. As a result, relatively high water pressure (water pressure of the cooling water discharged from the block side inlet 15) acts on the intake side spacer 5IN and the exhaust side spacer 5EX to separate them. However, since the overlapping portion 70 as described above is provided in the first connecting portion 5A of the water jacket spacer 5, the intake side spacer 5IN and the exhaust side spacer 5EX may be slightly deformed and separated by water pressure. Also, no gap is formed between both end portions 41A and 42A. Therefore, cooling water is prevented from flowing into the inside of the water jacket spacer 5 from between both end portions 41A and 42A. In order to enjoy such an effect more reliably, as shown in FIG. The length L1 of the overlapping portion 70 is set so that the relationship L1>L2.

FIG. 14 is an exploded perspective view of a main part of the water jacket spacer 5 showing a second connecting portion 5B that is a connecting portion on the opposite side (+X side) to the first connecting portion 5A.

The second connecting portion 5B is a portion where the other end side (+X side) end portion 41B of the intake side spacer 5IN and the other end side (+X side) end portion 42B of the exhaust side spacer 5EX are connected. The configuration of the second connecting part 5B is basically the same as the configuration of the first connecting part 5A. That is, the second connecting portion 5B connects the intake side spacer 5IN and the exhaust side spacer 5EX, and in this connected state, the second connecting portion 5B restricts the relative displacement of the end portions 41B and 42B in the cylinder row direction (X direction). It includes an upper regulating part 51B and a second lower regulating part 52B that regulates the relative displacement of the end parts 41B and 42B in the vertical direction (Z direction) and the width direction (Y direction).

Like the first upper regulating part 51A, the second upper regulating part 51B includes a plate-like protrusion 55 extending in the -Y direction from the end part 41B of the intake spacer 5IN, and a plate-like protrusion 55 extending along the outer wall surface 501 of the exhaust side spacer 5EX. and a regulating wall section 56 provided therein. A part of the plate-like protruding piece 55 is fitted between the outer wall surface 501 of the exhaust side spacer 5EX and the regulating wall 56, so that the end portion 41B of the intake side spacer 5IN and the end portion of the exhaust side spacer 5EX 42B in the cylinder row direction (X direction) is regulated.

Further, like the first lower regulating part 52A, the second lower regulating part 52B includes an engaging piece part 62 extending in the -Y direction from the end part 41B of the intake side spacer 5IN, and an outer wall surface of the exhaust side spacer 5EX. 501, and an engaged portion 63 provided at 501. Then, by engaging the engaging piece portion 62 with the engaged portion 63, the distal end portion 41B of the intake side spacer 5IN and the distal end portion 42B of the exhaust side spacer 5EX are aligned in the vertical direction (Z direction) and the width direction (Z direction). direction) is regulated.

Note that the second connecting portion 5B is not provided with an overlapping portion 70 like the first connecting portion 5A. This is because the block side inlet 15 is not opposed to the +X side end of the water jacket spacer 5, and the water pressure of the cooling water discharged from the block side inlet 15 is applied to the end 41B of the intake side spacer 5IN and the exhaust side. This is because it does not directly act on the end portion 42B of the side spacer 5EX. In addition, in this embodiment, the end portions 41B and 42B correspond to the "second end portion" according to the present invention.

[Effect]
In the cooling structure for the engine 1, the water jacket spacer 5 is composed of an intake side spacer 5IN and an exhaust side spacer 5EX, which are connected to each other at one end (-X end) and the other end (+X end) in the cylinder row direction. It is something. As mentioned above, the relative displacement of the intake side spacer 5IN and the exhaust side spacer 5EX in three mutually orthogonal directions is regulated: the cylinder row direction (X direction), the vertical direction (Z direction), and the width direction (Y direction). Concatenated in state. Therefore, the intake side spacer 5IN and the exhaust side spacer 5EX are unlikely to shift, and the connected state of both spacers 5IN and EX, that is, the assembled state of the water jacket spacer 5, is stably maintained.

Therefore, when assembling the engine, the intake side spacer 5IN and the exhaust side spacer 5EX may be misaligned, making it difficult to insert them into the water jacket 22. Insertion can prevent inconveniences such as not being able to obtain a targeted water flow (flow of cooling water) and, furthermore, not being able to obtain a desired cooling effect.

Further, in this water jacket spacer 5, the upper regulating parts 51A, 51B and the lower regulating parts 52A, 52B, which are the parts regulating the above-mentioned relative displacement, are located above (+Z side). In other words, the water jacket spacer 5 is configured such that the upper regulating portions 51A, 51B and the lower regulating portions 52A, 52B are arranged in a relatively spacious area of the water jacket 22. Therefore, with this configuration of the water jacket spacer 5, the intake side spacer 5IN and the exhaust side spacer 5EX can be connected without any gaps, and displacement in each of the above directions (X direction, Y direction, and Z direction) can be reliably regulated. There is an advantage that the upper restricting portions 51A, 51B and the lower restricting portions 52A, 52B that can be provided can be provided with a margin.

In particular, the first lower regulating part 52A and the second lower regulating part 52B regulate displacement in two directions, the vertical direction (Z direction) and the width direction (Z direction), so they regulate displacement in the vertical direction. Compared to the case where the regulating section for regulating displacement and the regulating section for regulating displacement in the width direction are provided separately, the regulating section is consolidated. Therefore, as described above, this is an advantageous configuration for providing the restriction portions (the first lower restriction portion 52A and the second lower restriction portion 52B) within the limited upper region of the space of the water jacket 22. I can say that.

Furthermore, the portion of the first connecting portion 5A (-X side connecting portion) of the water jacket spacer 5 that is lower than both the regulating portions 51A and 51B, that is, the portion where the block side inlet 15 faces, is as described above. Since the overlapping part 70 of the intake side spacer 5IN and the exhaust side spacer 5EX is provided, there is no part that locks the intake side spacer 5IN and the exhaust side spacer 5EX like the first lower regulating part 52A. , the formation of a gap between the end portions 41A and 42A is suppressed. That is, even if the intake side spacer 5IN and the exhaust side spacer 5EX are separated to some extent by the water pressure of the cooling water discharged from the block side inlet 15, the extension portion 72 and the stepped portion 71 overlap, so that the end portion Formation of a gap between 41A and 42A is suppressed. Therefore, cooling water enters the inside of the water jacket spacer 5 from a portion of the first connecting portion 5A that is lower than the first upper regulating portion 51A and the first lower regulating portion 52A, and an unintended water flow is formed. This effectively prevents the inconvenience of not being able to obtain the desired cooling effect.

In this case, as described above, an expansion member 36 is provided on the inner circumferential surface of the water jacket spacer 5 (at a position facing the block side inlet 15), and the expansion pressure of the expansion member 36 causes the water jacket spacer 5 to move toward the outer block. It is pressed against the inner wall surface of 24. Therefore, the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX are relatively difficult to displace. Therefore, in this respect as well, the formation of a gap between the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX due to the water pressure of the cooling water discharged from the block side inlet 15 is suppressed. .

[Modifications, etc.]
The cooling structure for the engine 1 described above is an example of a preferred embodiment of the engine cooling structure according to the present invention, and its specific configuration can be changed as appropriate without departing from the gist of the present invention. For example, the following configuration can also be adopted.

(1) In the embodiment, the water jacket spacer 5 has a half-split structure along a line in the cylinder row direction (X direction). That is, the water jacket spacer 5 is composed of an intake side spacer 5IN and an exhaust side spacer 5EX. However, the present invention is not limited to such a completely divided structure, but also a structure in which only one end of the water jacket spacer is divided, and the ends of the water jacket spacer in the circumferential direction are connected to each other at the one end. The present invention can also be applied to an engine including a water jacket spacer with a partially divided structure, and in that case, the same effects as those of the above embodiment can be obtained.

(2) In the embodiment, the overlapping portion 70 is configured such that the extension portion 72 of the end portion 42A of the exhaust side spacer 5EX and the stepped portion 71 of the end portion 41A of the intake side spacer 5IN overlap with each other. . However, the specific configuration of the overlapping portion 70 is not limited to the configuration of the embodiment as long as the end portion 41A of the intake side spacer 5IN and the end portion 42A of the exhaust side spacer 5EX overlap each other. , can be changed as appropriate.

(3) In the embodiment, each regulating portion 51A, 51B, 52A, 52B is provided above the middle portion of the water jacket spacer 5 in the vertical direction. However, the positions of each regulating portion 51A, 51B, 52A, 52B are not limited to this, and can be changed as appropriate. In that case, in the first connecting portion 5A, the overlapping portion 70 is provided in a portion other than the regulating portions (the first upper regulating portion 51A and the first lower regulating portion 52A) in the vertical direction (Z direction). preferable.

(4) In the embodiment, the expansion member 36 is provided over almost the entire circumference of the inner peripheral surface (inner wall surface) of the water jacket spacer 5, but for example, the expansion member 36 is provided at the -X side end of the water jacket spacer 5. The expansion member 36 may be provided only at a corresponding position, that is, a position corresponding to the block side inlet 15. In this case as well, at the −X side end of the water jacket spacer 5, the expansion pressure of the expansion member 36 presses the water jacket spacer 5 against the inner wall surface of the outer block 24, so that the end portion 41A of the intake side spacer 5IN Relative displacement of the exhaust side spacer 5EX with the end portion 41B is suppressed. Therefore, the same effects as in the embodiment can be expected.

1 Engine 2 Cylinder block 5 Water jacket spacer 5IN Intake side spacer 5EX Exhaust side spacer 5A First connection part 5B Second connection part 14 Water supply inlet port part 15 Block side inlet (supply port)
21 Cylinder 21L Cylinder row 22 Water jacket 36 Expansion member 41A End part (first end part)
41B End part (second end part)
42A End part (first end part)
42B End part (second end part)
51A First upper regulating section (regulating section)
51B Second upper regulating section 52A First lower regulating section (regulating section)
52B Second lower regulating part 70 Overlapping part 71 Step part 72 Extension part

Claims (7)

A cylinder block including a cylinder row in which a plurality of cylinders are arranged in a line in a predetermined direction, and a water jacket formed to surround the cylinder row;
An engine cooling structure comprising: a water jacket spacer having a cylindrical shape surrounding the cylinder row and disposed within the water jacket to control the flow of cooling water,
The water jacket spacer is divided into one end and the other end in the cylinder row direction, and has a first end that is connected to each other at the one end and a second end that is connected to each other at the other end. It has
The cylinder block includes a supply port for supplying cooling liquid into the water jacket at a position corresponding to the one end of the water jacket spacer,
Of the first end portions and the second end portions of the water jacket spacer, only the first end portions overlap each other over a range longer than the length of the supply port in the cylinder axial direction. An engine cooling structure characterized by: The engine cooling structure according to claim 1,
An engine cooling structure comprising: a water pump that is attached to the cylinder block on the same side as the one end of the water jacket spacer in the cylinder row direction and pumps cooling water toward the supply port. . The engine cooling structure according to claim 1 or 2,
An engine cooling structure characterized in that each of the first end portions of the water jacket spacer is provided with a regulating portion that restricts relative displacement of each of the first end portions by engaging with each other. . The engine cooling structure according to claim 3,
An engine cooling structure characterized in that each of the first end portions overlaps each other at a portion other than the position of the restriction portion in the cylinder axial direction. The engine cooling structure according to claim 4,
The water jacket has a shape in which the flow passage width gradually narrows from the cylinder head side toward the opposite cylinder head side in the cylinder block,
The engine cooling structure is characterized in that the restriction portion is provided at a position of each of the first end portions that is biased toward the cylinder head side with respect to an intermediate portion of the water jacket spacer in the cylinder axis direction. . The engine cooling structure according to any one of claims 1 to 5,
An engine cooling structure characterized in that an expansion member is provided on an inner wall surface of the water jacket spacer at a position corresponding to the supply port. The engine cooling structure according to any one of claims 1 to 6,
An engine cooling structure characterized in that the supply ports are provided at symmetrical positions with the cylinder axis as a boundary in an orthogonal direction that is perpendicular to both the cylinder row direction and the cylinder axis direction.

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