JP6718222B2 - Internal combustion engine - Google Patents

Description

The present invention relates to an internal combustion engine, and is characterized by a cylinder block cooling means.

A water jacket that surrounds a group of cylinder bores is formed in a cylinder block that constitutes an internal combustion engine, and cooling water is passed through this water jacket, but there is a problem that the cooling between the bores becomes insufficient. Therefore, for example, as disclosed in Patent Document 1, a cooling water passage having an inlet opening on the inner wall surface of the water jacket and an outlet opening on the upper surface is provided between the bores, and the cylinder is provided from this cooling water passage. Cooling water is made to flow toward the head.

JP2012-188959A

It is necessary to pass the required amount of cooling water through the cooling water passage to properly cool the space between the bores.However, since the cooling water passage is open in the state of a horizontal hole in the wall of the water jacket, the cooling water is cooled. There is a problem that it is difficult to pass a required amount of cooling water through the cooling water passage because a phenomenon of passing through the entrance of the water passage occurs.

The present invention is intended to solve this problem.

The present invention is
``In the cylinder block, a group of cylinder bores arranged in the crank axis direction and a water jacket that surrounds the group of cylinder bores are formed, and an inlet is provided in a bore portion between adjacent cylinder bores of the cylinder block. A cooling water passage is provided, which has an opening in the water jacket and an outlet opening in the upper surface of the cylinder block .
Further, a water jacket spacer is arranged on the water jacket so as to overlap the inner peripheral surface of the water jacket.
It has a basic configuration.

And in the above basic configuration,
"In the water jacket spacer, a recessed portion that overlaps a portion of the water jacket between the bores is formed, and in the recessed portion, a communication hole that communicates with an inlet of the cooling water passage is formed, A stopper piece, which projects the cooling water flowing in the circumferential direction of the water jacket and guides it to the communication hole, is provided at an area downstream of the communication hole in the recessed portion so as to project outward.
Also, an inclined main guide rib that guides the cooling water flowing in the circumferential direction through the water jacket to the stopper piece on a portion of the outer side surface of the recessed portion that is below the stopper piece, and below the main guide rib. And the inclined auxiliary guide ribs located at the position where the auxiliary guide ribs are inclined outwardly with the inclination of the auxiliary guide ribs being less than that of the main guide ribs. "
Is added.

In the present invention, since the stopper pieces and the guide ribs of the water jacket spacer can promote that the cooling water flowing through the water jacket flows into the cooling water passage, the cooling water passage is provided with an amount of cooling water that can accurately cool the space between the bores. Can be threaded. Since the water jacket spacer is separate from the cylinder block, it can be applied to existing cylinder blocks and has excellent versatility.

Since the water jacket spacer is also used as the guide member for the cooling water and it is not necessary to newly prepare a dedicated member, there is an advantage that the manufacturing cost and the labor for mounting can be reduced. Further, controlling the cooling water to flow through the cooling water passage without excess or deficiency can be easily realized by providing the water jacket spacer with the stopper piece, the main guide rib, and the auxiliary guide rib .

FIG. 1 is a diagram showing an embodiment, (A) is a partial plan view of only a cylinder block, and (B) is a vertical cross-sectional side view showing a water jacket spacer. It is a top view in the state where the water jacket spacer was attached. It is a perspective view of a water jacket spacer. (A) is a partially broken plan view of a main part, and (B) is a sectional view taken along line BB of (A).

Next, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the state viewed from the crank axis direction is a front view, and the crank axis direction is the front-back direction.

(1). Outline First, the outline (basic configuration) will be described. As shown in FIG. 1(A), the internal combustion engine of the present embodiment has four cylinders, and therefore, in the cylinder block 1, first to fourth four cylinder bores 3 to 6 arranged in the direction of the crank axis 2 are arranged. Are formed. A closed loop water jacket 7 is formed outside the group of cylinder bores 3 to 6 in the cylinder block.

The water jacket 7 is a recessed portion 7a that approaches the crankshaft axis 2 (more precisely, the center line of the cylinder bore group) at a portion of the inter-bore portion 8 that is a portion between the adjacent cylinder bores. Therefore, the inter-bore portion 8 is a portion sandwiched by the two recessed portions 7a sandwiching the crank axis 2. A pair of cooling water passages 9 is formed in each of the inter-bore portions 8 on both sides of the crank axis 2.

As shown in FIG. 4(B), the cooling water passage 9 includes a first drill hole 9a in an inclined posture which is opened in the recess 7a of the water jacket 7 and a second drill hole which is opened toward the upper surface of the cylinder block 1. 9b, the end of the first drill hole 9a serves as the inlet 10, and the upper end of the second drill hole 9b serves as the outlet 11. A cylinder head 12 overlaps the cylinder block 1 via a gasket 1a, but a suction passage 13 communicating with the second drill hole 9b is open in the gasket 11 and the cylinder head 12.

A water jacket spacer 15 made of synthetic resin is attached to the water jacket 7 by fitting from above. The water jacket spacer 15 is a set of a pair of one located on the exhaust side and one located on the intake side with the crank axis 2 interposed therebetween. In the figure, the one located on the exhaust side is shown. This is simply referred to as the water jacket spacer 15.

The exhaust-side water jacket spacer 15 and the intake-side water jacket spacer 15 are attached to the water jacket 7 in a state where their ends are in contact with each other and engaged with each other. Therefore, the left and right water jacket spacers 15 form a closed loop.

The water jacket spacer 15 is adapted to overlap the inner peripheral surface of the water jacket 7 is basically a form similar water jacket 7. Therefore, the first to fourth arcuate curved portions 16 to 19 corresponding to the cylinder bores 3 to 6 and the first to third recessed portions 20 to 22 corresponding to the three recessed portions 7a of the water jacket 7 are provided. Have The upper ends of the arcuate curved portions 16 to 19 are slightly lower than the upper end of the water jacket 7.

(2). Details of Water Jacket 7 As shown in FIGS. 1 and 3, each of the second to fourth arcuate curved portions 17 to 19 is provided with three rectangular window holes 23 in the circumferential direction to form each rectangular shape. A sheet-shaped heat insulating material 24 is attached to the window hole 23. When the heat insulating material 24 absorbs water, it swells and comes into close contact with the inner surface of the water jacket 7. A spring piece 25 that comes into contact with the outer peripheral surface of the water jacket 7 is provided at each square window hole 23. The water jacket spacer 15 is held in a state of overlapping with the inner peripheral surface of the water jacket 7 by the pressing action of the spring piece 25. In FIG. 3, the tip of the spring piece 25 is located outside the water jacket 7, but this is because the state before deformation is displayed.

It should be noted that the second to fourth arc-shaped curved portions 17 to 19 are formed with an upward cutout 26 and a downward cutout 27 located at a substantially middle portion in the circumferential direction. The notches 26 and 27 are caulked and fixed to the water jacket spacer 15. The spring piece 25 is also formed on the holding plate.

As can be clearly understood from FIG. 3, the first arcuate curved portion 16 of the water jacket 7 is formed with a partition wall 28 that abuts the outer peripheral surface of the water jacket 7 so as to extend from the upper end to the lower end. The cooling water pumped by the water pump is discharged toward the first arc-shaped curved portion 16 from the inflow passage 29 (see the alternate long and short dash line in FIG. 1B) provided in the cylinder block 1. Due to the presence, the cooling water flows toward the second arcuate curved portion 17 side.

Then, the cooling water goes around the water jacket 7 almost once, and then is sent to the cooling water passage of the cylinder head through a hole (not shown). The partition wall 28 does not exist in the water jacket spacer on the intake side.

As can be easily understood from FIG. 3, each recess 20 to 22 of the water jacket spacer 15 is provided with a guide head 31 that is in close contact with or close to the recess 7a of the water jacket 7 so as to project upward. The head 31 is integrally provided with a top plate 32 protruding from the upper end in the outer peripheral direction of the water jacket 7 and an outward side stopper piece 33 connected to the guide head 31 and the top plate 32. .. The side stopper piece 33 is the stopper piece described in the claims.

A communication hole 34 for allowing water to pass through the inlet 10 of the cooling water passage 9 is formed in the guide head 31. The side stopper piece 33 is located downstream of the water flow with the communication hole 34 interposed therebetween. Therefore, the flow of the cooling water is stopped by the side stopper piece 33.

The first arcuate curved portion 17 of the water jacket spacer 15 is provided with a first main guide rib 35 continuous with the side stopper piece 33 of the first recess 20. The first main guide ribs 35, from the beginning of the upstream side to the end on the downstream side is inclined to a greater height so that the termination is continuous to the side stopper piece 33 of the first recess 20.

The height of the starting end of the first main guide rib 35 is approximately at the intermediate height position of the first arcuate curved portion 17, and when viewed in the circumferential direction, the portion protruding to the outermost side of the first arcuate curved portion 17 It is located a little downstream than. Further, as shown in FIG. 2, the outward height is about half the width of the flow passage outside the side stopper piece 33. Therefore, the cooling water can also flow vertically even at the location of the first arc-shaped curved portion 17.

As shown in FIG. 3, below the first main guide rib 35, an auxiliary guide rib 36 having a length that overlaps the first main guide rib 5 in a plan view is provided. The end of the auxiliary guide rib 36 is located at the location of the first recess 20. The auxiliary guide rib 36 is also inclined, but the degree of inclination is less than that of the first main guide rib 35. Therefore, the flow direction of the cooling water flowing below the first main guide rib 35 is controlled by the auxiliary guide rib 36 so as to change the flow upward.

As shown in FIG. 2, the starting end of the auxiliary guide rib 36 is adapted to projection height abutting or close to the outer peripheral surface of the water jacket 7, halfway toward the end direction is height gradually decreases There is. And about the rear half is about the same height.

The second arc-shaped curved portion 18 is formed with a second main guide rib 37 extending toward the second recessed portion 21, and the end of the second main guide rib 37 is at the end of the side stopper piece 33 of the second recessed portion 21. It is continuous at the bottom. The second main guide rib 37 is located on the rear side in the circumferential direction of the second arcuate curved portion 18 and above the rectangular window hole 23. For this reason, although the height increases from the start end toward the end, the tilted posture is considerably loose.

A third main guide rib 38 is formed at the location of the third recess 22. Most of the third main guide ribs 38 are located at the third recessed portions 22, with the starting end thereof slightly overlapping the third arcuate curved portion 18. However, the third main guide rib 38 has a shape elongated downward, and its starting end (lower end) is located substantially at the vertical middle height of the third recess 22.

(3). Summary In the present embodiment, the guide head 31, the top plate 32, the side stopper piece 33, and the first to third main guide ribs 35, 37, 38 having the communication holes 34 are guide portions. However, the auxiliary guide rib 36 can also be seen as a part of the guide member.

Then, a part of the cooling water that has flowed into the location of the first arcuate curved portion 17 is directed by the guiding action of the first main guide ribs 35 toward the location of the first recessed portion 20 of the water jacket 7, At the location of the first recessed portion 20, the cooling water is guided (direction is changed ) toward the inlet 10 of the cooling water passage 9 mainly by the damming action of the side stopper piece 33. As a result, the exhaust side portion of the first inter-bore portion 8 between the first cylinder bore 2 and the second cylinder bore 3 is forcibly cooled.

Next, a part of the cooling water is rectified by the guide action of the auxiliary guide ribs 36 toward the second recessed portion 21 of the water jacket 7, and the cooling water reaching the second recessed portion 21 is cooled by the second recessed portion 21. At 21 points, the side stopper pieces 33 are guided toward the inlet 10 of the cooling water passage 9 by the damming action of the side stopper pieces 33. As a result, the exhaust side portion of the second inter-bore portion 8 between the second cylinder bore 3 and the third cylinder bore 4 is forcibly cooled.

Since the cooling water also flows in the circumferential direction even outside the first main guide ribs 35, the second main guide ribs 37 also have a role of flowing outside the first main guide ribs 35 and directing the cooling water toward the second recess 21. Is playing.

The cooling water flowing below the auxiliary guide rib 36 flows in the circumferential direction while changing its direction upward due to the guide action of the auxiliary guide rib 36, and flows outside the cooling water and the first main guide rib 35 and the auxiliary guide rib 36. When the cooling water reaches the third recessed portion 22, it is rectified by the third main guide rib 38 so as to be directed upward, and this water flow is provided at the location of the third recessed portion 22 with the side stopper piece 33 and the top plate. By the damming action with 32, it is guided toward the inlet 10 of the cooling water passage 9. As a result, the exhaust side portion of the third inter-bore portion 8 between the third cylinder bore 4 and the fourth cylinder bore 5 is forcibly cooled.

In this way, the portion between the bores 8 on the exhaust side is forcibly cooled. Further, the cooling water that has spilled around to the intake side is rectified by the guide action of the first main guide ribs 35 in the water jacket 7 provided on the intake side so that a part thereof is rectified into a flow toward the upper end of each recessed portion. By the guide action of the stopper piece 33 and the like, it is forcibly sent to the cooling water passage 9 on the intake side. As a result, cooling of the intake side of the inter-bore portion 8 is also ensured.

As described above, in this embodiment, the cooling water is forcibly passed through the cooling water passages 9 of the inter-bore portions 8 so that the inter-bore portions 8 can be cooled firmly. As a result, it is possible to prevent uneven deformation of the cylinder bores 3 to 5, reduce mechanical loss, and improve fuel efficiency. Further, since the guide portion is provided on the water jacket spacer 15 , the structure is not complicated and the assembly is not troublesome.

In the above-described embodiment, the heat insulating material is attached to the water jacket 7, but it goes without saying that the heat insulating material may be omitted. Further, the shape and the number of guide ribs, Ru can be arbitrarily changed as required.

The present invention can be actually embodied in an internal combustion engine. Therefore, it can be used industrially.

1 Cylinder Block 2 Crank Axis 3-6 Cylinder Bore 7 Water Jacket 7a Water Jacket Recessed Portion 8 Bore Interspace 9 Cooling Water Passage 10 Inlet 11 Outlet 15 Water Jacket Spacer 16-19 Circular Curved Section 20-22 Water Jacket Spacer Recess Entry part 31 Guide head forming the guide part 32 Top plate forming the guide part 33 Side stopper piece forming the guide part 34 Communication hole forming the guide part 35, 37, 38 Main guide rib forming the guide part 36 Guide part Auxiliary guide ribs

Claims (1)

The cylinder block is formed with a group of cylinder bores aligned in the direction of the crank axis and a water jacket surrounding the group of cylinder bores, and the inlet is provided in the bore portion between adjacent cylinder bores of the cylinder block. A cooling water passage is provided with an opening in the water jacket and an outlet opening in the upper surface of the cylinder block.
Further, in the water jacket, a water jacket spacer is arranged so as to overlap the inner peripheral surface of the water jacket,
In the water jacket spacer, a recessed portion that overlaps a portion of the water jacket between the bores is formed, and in the recessed portion, a communication hole that communicates with an inlet of the cooling water passage is formed, and A stopper piece, which projects the cooling water flowing in the circumferential direction of the water jacket and guides it to the communication hole, is provided on the downstream side of the communication hole in the recessed portion so as to project outward.
In addition, an inclined main guide rib that guides the cooling water flowing in the circumferential direction through the water jacket to the stopper piece on a portion of the outer surface of the recessed portion that is below the stopper piece, and below the main guide rib. And an inclined auxiliary guide rib positioned at, the auxiliary guide rib is provided so as to project outward with the inclination of the auxiliary guide rib being less than the inclination of the main guide rib.
Internal combustion engine.

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