JP2018109361A - Water-cooling structure for multiple cylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-cooling structure for a multiple cylinder engine that can perform sufficient inter-bore cooling without causing an increase in engine length with further structural devising and strike a balance between miniaturization of the engine length and cooling performance.SOLUTION: A water-cooling structure for a multiple cylinder engine includes: a cylinder block 1; a cylinder 2 of in-line three cylinders; and a water jacket W around the cylinder 2. The water jacket W includes: a pair of main flow passages 7, 8 formed while extending in a cylinder alignment direction on an outer side of the cylinder 2; and inter-bore flow passages 9, 10 formed between the adjacent cylinders 2, 2 while connecting the pair of main flow passages 7, 8 to each other. A guide rib h capable of leading coolant flowing through the main flow passages 7, 8 to the inter-bore flow passages 9, 10 is provided to each of inter-bore flow passages 9, 10. A plurality of guide ribs h is configured so that a guide rib h located nearer to a downstream side in a coolant flow direction protrudes longer in a direction crossing with a cylinder shaft center and a cylinder shaft center direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a water cooling structure applied to an industrial diesel engine, and more specifically, a multi-cylinder engine including a plurality of cylinders arranged in a cylinder block and a water jacket formed around the plurality of cylinders. It relates to the water cooling structure.

  As a water-cooling structure in a multi-cylinder engine, a configuration in which a water jacket is provided around a cylinder or a cylinder head, which is a heat generation point, to circulate cooling water is common. In the case of a multi-cylinder engine having two or more cylinders such as an in-line four-cylinder engine, cooling between adjacent cylinders, that is, cooling between bores is often required.

  When there are two or more cylinders, in order to make the engine length compact, it is preferable to arrange adjacent cylinders as close as possible. However, between the cylinders that are also heat generation sources, that is, between the bores, the thermal load is most severe. Therefore, conventionally, as disclosed in Patent Document 1, means for forming a water channel by drilling a hole in the portion between the bores of the cylinder by post-processing has been adopted.

  The drilling holes allow cooling water to pass between the bores and improve the cooling performance. However, if the thermal load is higher, such as a high compression engine or a large displacement engine, it is desirable to enhance the cooling between the bores. . Therefore, conventionally, a means for further improving the cooling performance by using a core kelen or the like to clearly separate adjacent cylinders and provide a clear water jacket between the bores has been adopted.

  In the latter prior art, although the cooling performance can be improved, the distance between the bores is required, and as a result, there is a problem that the engine length tends to be large. The former prior art is advantageous in terms of engine length, but is inferior to the latter prior art in terms of cooling. As described above, in the conventional water cooling structure of the water cooling engine, there is a contradiction between suppressing the increase in engine length and improving the cooling performance, and it has been difficult to achieve both of them.

JP 2007-023824 A JP 2003-193836 A

  An object of the present invention is to provide a water cooling for a multi-cylinder engine that can achieve both a reduction in the engine length and a cooling performance by further reducing the engine length without causing an increase in the engine length, thereby achieving sufficient cooling between the bores. In providing the structure.

The invention according to claim 1 is a water cooling structure of a multi-cylinder engine.
A plurality of cylinders 2 arranged in a cylinder block 1;
A water jacket W formed around the cylinders 2;
The water jacket W includes a pair of main flow passages 7 and 8 that are formed outside the cylinder 2 in a cylinder arrangement direction, and a cylinder 2 adjacent to the pair of main flow passages 7 and 8 that are connected to each other. And is configured to have an inter-bore flow path 9, 10 formed between the two,
A guide rib h capable of guiding the cooling water flowing through the main flow paths 7 and 8 to the inter-bore flow paths 9 and 10 is provided for each of the plurality of inter-bore flow paths 9 and 10.
The plurality of guide ribs h are configured such that the protruding length in the direction intersecting the cylinder axis becomes longer toward the downstream guide rib h in the flow direction of the cooling water.

The invention according to claim 2 is a water cooling structure of a multi-cylinder engine.
A plurality of cylinders 2 arranged in a cylinder block 1;
A water jacket W formed around the cylinders 2;
The water jacket W includes a pair of main flow passages 7 and 8 formed in a state extending in the cylinder arrangement direction outside the cylinder 2 and a cylinder 2 adjacent to the pair of main water passages 7 and 8 connected to each other. And is configured to have an inter-bore flow path 9, 10 formed between the two,
A guide rib h capable of guiding the cooling water flowing through the main flow paths 7 and 8 to the inter-bore flow paths 9 and 10 is provided for each of the plurality of inter-bore flow paths 9 and 10.
The plurality of guide ribs h are configured such that the downstream guide rib h in the coolant flow direction is longer in the cylinder axial direction.

The invention according to claim 3 is the water cooling structure of the multi-cylinder engine according to claim 1 or 2,
The guide rib h is formed in a barrel portion 4 that forms the cylinder 2 in the cylinder block 1.

The invention according to claim 4 is the water-cooling structure of the multi-cylinder engine according to claim 1 or 2,
The guide rib h is formed in a cylinder outer frame portion 5 that surrounds the water jacket W in the cylinder block 1.

The invention according to claim 5 is the water cooling structure for a multi-cylinder engine according to any one of claims 1 to 4,
The guide rib h has an arc shape along the circumferential direction of the cylinder 2.

According to the present invention, the protruding length in the direction intersecting the cylinder axis of the downstream guide rib and the length in the cylinder axis direction are made longer (longer) than the corresponding protruding length and length of the upstream guide rib. Therefore, the cooling water flowing into the inter-bore channel on the downstream side where the flow of the cooling water becomes weak, for example, the amount of cooling water flowing into the inter-bore channel is balanced so that it becomes equal on the upstream side and the downstream side. The uptake action can be enhanced.
As a result, through further structural improvements, it is possible to provide sufficient cooling between the bores without causing an increase in the engine length, and provide a water-cooling structure for a multi-cylinder engine that achieves both a reduction in engine length and cooling performance. can do.

Plan view of cylinder part showing cylinder block Aa line sectional view of the cylinder block shown in FIG. Bb sectional view of the cylinder block shown in FIG. Cc line sectional view of the cylinder block shown in FIG. The flow of the cooling water in a water jacket is shown, (a) is a case where it is a guide wall of a mutually reverse direction (Embodiment 1), (b) is a case where it is a guide wall of the same direction mutually (Embodiment 2).

  Hereinafter, an embodiment of a water-cooling structure of a multi-cylinder engine according to the present invention will be described as applied to a vertical in-line three-cylinder water-cooled diesel engine with reference to the drawings.

  As shown in FIGS. 1 and 4, this engine includes a water jacket (cylinder jacket) W formed around a plurality of cylinders 2 in which a plurality (three) of cylinders 2 are arranged in series on a cylinder block 1. It is composed of a water-cooled engine equipped. The water jacket W includes barrel portions (cylinder walls) 4, 4, 4 that are formed in a substantially cylindrical shape to form the cylinders 2 in the cylinder block 1, a cylinder outer frame portion 5 in the cylinder block 1, and a cylinder ceiling. This is an internal space for cooling water circulation formed between the wall 3 and the wall 3. Note that a portion protruding to the left on the front side of the cylinder block 1 is a fuel injection case portion 26.

1 and 4, the intake side of the cylinder block 1 is on the left, the exhaust side is on the right, the side with the cooling water inlet 6 to the water jacket W is the front, and the opposite side is the rear.
The water jacket W is a pair of main flow paths that are formed outside the cylinder 2 (barrel portion 4) in the cylinder arrangement direction, and is a pair of main flow paths 7 and an exhaust side main flow path 8 and a pair of main flow paths 7. , 8 are connected to each other between adjacent cylinders 2 (barrel portion 4), and the first and second bore channels 9, 10 are connected to the main channels 7, 8 at the start and end. It has front and rear end flow paths wf, wr.

  As shown in FIGS. 1 and 4, the cylinder ceiling wall 3 to which the cylinder head (not shown) is connected to the upper surface 3A via a gasket (not shown) has a bolt insertion hole 3a, a communication hole 3b, a drill hole. A hole 3c is formed. The bolt insertion holes 3 a are holes through which bolts for connecting the cylinder block 1 and the cylinder head (not shown) are passed, and are opened at a plurality of locations (14 locations) around each cylinder 2. The communication hole 3b is a relatively large passage for flowing the cooling water from the water jacket W to the water jacket of the cylinder head (cylinder head jacket: not shown), and communicates with any of the main flow paths 7 and 8. It is formed in plural (12 places).

  The drill holes 3c are formed at a total of four locations at the front and rear ends of the cylinder ceiling wall 3 so as to communicate with the front and rear ends of the front end flow path wf and the rear end flow path wr of the water jacket W, respectively. In addition, between the cylinders 2 and 2 adjacent to each other on the cylinder ceiling wall 3, as an oblique hole extending from the upper left to the lower right in a state of communicating with the first inter-bore channel 9 and the second inter-bore channel 10. , Each one is formed.

  3 and 4, the hole provided at the front end of the cylinder block 1 so as to face the front end flow path wf is provided with an auxiliary device such as a thermostat (not shown) or a sensor (not shown) for measuring the coolant temperature. The mounting hole 25 for mounting may be used.

  Now, the cooling water sent from the cooling water inlet 6 to the water jacket W by the water pump (not shown) is first separated from the front end flow path wf to the left and right to move backward through the intake side main flow path 7 and the exhaust side main flow path 8. And also flows in the first and second flow paths 9, 10 along the way. Then, the cooling water flows upward while flowing backward through the water jacket W, and flows into the cylinder head jacket (not shown) through the plurality of communication holes 3b and the plurality of drill holes 3c. It flows toward the cooling water outlet (not shown).

Embodiment 1
As shown in FIG. 4 and FIG. 5A, guide ribs h (11 to 14) capable of guiding the cooling water flowing through the main flow paths 7 and 8 to the inter-bore flow paths 9 and 10 are provided in the cylinder block 1. , Formed as four cantilever protruding walls. More specifically, the first guide rib 11 protrudes from the front part of the second barrel part 4 between the front and rear to the intake side main flow path 7, and the second guide protrudes from the front part of the second barrel part 4 between the front and rear to the exhaust side main flow path 8. A guide rib 12, a third guide rib 13 protruding from the front side portion of the rear third barrel portion 4 to the intake side main flow path 7, and a fourth portion protruding from the front side portion of the rear side third barrel portion 4 to the exhaust side main flow path 8. Each guide rib h is constituted by the guide rib 14.

  The cooling water flowing from the front to the rear in the intake-side main flow path 7 near the first cylinder 2 by the first guide rib 11 exhibiting an arc shape along the circumferential direction of the first cylinder 2 on the front side when viewed in the vertical direction, A guide action to lead to the first inter-bore channel 9 toward the right is exhibited. With the second guide ribs 12 having an arc shape along the circumferential direction of the first cylinder 2 on the front side when viewed in the vertical direction, the cooling water flowing from the front to the rear in the exhaust-side main flow path 8 near the first cylinder 2 is A guide action to lead to the first inter-bore channel 9 toward the left is exhibited.

  By the third guide wall 13 having an arc shape along the circumferential direction of the second cylinder 2 when viewed in the vertical direction, the cooling water flowing from the front to the rear in the intake side main flow path 7 near the second cylinder 2 is The guide action leading to the second inter-bore channel 10 is exhibited. By the fourth guide wall 14 having an arc shape along the circumferential direction of the second cylinder 2 when viewed in the vertical direction, the cooling water flowing from the front to the rear in the exhaust-side main flow path 8 near the second cylinder 2 is left. The guide action leading to the second inter-bore channel 10 is exhibited.

  As described above, the first guide rib 11 and the third guide rib 13 corresponding to the inter-bore passages 9 and 10 adjacent to each other in the cylinder arrangement direction have the same direction for guiding the cooling water to the inter-bore passages 9 and 10. It is formed in the state. Then, the second guide rib 12 that guides the entry of the cooling water flowing through the exhaust-side main flow path 8 into the first inter-bore flow path 9 and the second boring flow path 10 of the cooling water flowing through the exhaust-side main flow path 8 are provided. The fourth guide ribs 14 that guide the entry are also formed so as to guide each other in the same direction.

  As a result, in the water jacket W, as shown in FIG. 5A, the cooling water flows through the pair of main flow paths 7 and 8 from the front to the back by the guide action of the first to fourth guide ribs 11 to 14. In the first and second bore passages 9 and 10, the flow is guided so as to generate a flow from the left end and the right end toward the left and right center. The cooling water that has flowed to the left and right center of each of the flow paths 9 and 10 between the bores flows out from the upper drill hole 3c toward the cylinder head jacket (not shown). With such a smooth flow of cooling water, a sufficient flow rate (and a flow rate per unit time of cooling water) is secured in the first and second flow paths 9, 10 between the bores, which are difficult to cool. Can be efficiently cooled without increasing the arrangement interval of the cylinders 2 and 2.

  That is, in the first inter-bore channel 9, the first and second guide ribs 11, 12 exhibit a cooling water intake (water intake) promoting action, so the width between the bores of the first inter-bore channel 9 is widened. It is possible to obtain an efficient cooling effect through a sufficient flow rate without any problem. Similarly, in the second inter-bore channel 10, the action of promoting the intake (intake) of cooling water by the third and fourth guide ribs 13, 14 is exerted, so the width between the bores of the second inter-bore channel 10 is increased. It is possible to obtain an efficient cooling effect through a sufficient flow rate without spreading.

  In the water-cooling structure of the multi-cylinder engine according to the first embodiment, the guide rib h protrudes in a direction (lateral direction such as the left-right direction or the front-rear direction) that intersects the cylinder axis as the downstream guide rib h in the coolant flow direction. The length is increased, and the length in the cylinder axial direction (vertical direction) is increased. That is, as shown in FIGS. 2 and 4, in the first and third guide ribs 11, 13, the amount of lateral protrusion from the corresponding barrel portion 4 to the intake side main flow path 7 and the height from the jacket bottom 15 are increased. In any case, the third guide rib 13 on the downstream side of the first guide rib 11 is set to be larger (see FIG. 3: the height t1 of the first guide rib 11 and the height t3 of the third guide rib 3). , T1 <t3).

  Similarly, in the second and fourth guide ribs 12 and 14, both the amount of lateral protrusion from the corresponding barrel portion 4 to the exhaust side main flow path 8 and the height from the jacket bottom 15 are greater than those of the second guide rib 12. Also, the fourth guide rib 14 on the downstream side is set larger. The difference in the lateral protrusion amount and height of the guide rib h is appropriately set according to various conditions such as the size, shape, angle, or number of cylinders (the number of flow paths between the bores). As an example, as shown in FIG. 2, the height of the first and second guide ribs 11 and 12 is lower than the height of the damming wall 16 (described later), and the height of the third and fourth guide ribs 13 and 14 is It is higher than the height of the blocking wall 16.

Since the amount of lateral protrusion of the downstream guide ribs 13 and 14 is larger (longer) than the amount of lateral protrusion of the upstream guide ribs 11 and 12, the flow to the first and second bore passages 9 and 10 is increased. The cooling water inflow amount is balanced so that the upstream side and the downstream side are equal to each other. For example, there is an effect that the cooling water intake action to the inter-bore channel on the downstream side where the cooling water flow becomes weak can be enhanced. .
Since the height of the downstream guide ribs 13 and 14 is higher (longer) than the height of the upstream guide ribs 11 and 12, the amount of cooling water flowing into the first and second flow passages 9 and 10 between the bores Are balanced so as to be equal to each other on the upstream side and the downstream side, for example, there is an effect that the cooling water intake action to the inter-bore channel on the downstream side where the flow of the cooling water becomes weak can be enhanced.

  Further, since the guide ribs h (11 to 14) have a circular arc shape that is concentric or substantially concentric with the circumferential direction of the cylinder 2 of the inter-bore passages 9 and 10 to which the cooling water is sent, the guide ribs 11 to 11 are provided. There is an advantage that the guiding action of the coolant 14 to the inter-bore flow paths 9, 10 can be made smoother.

As shown in FIGS. 2 and 3, the water jacket W includes a jacket bottom 15 and has a depth (vertical width) comparable to the vertical length of the barrel portion 4.
As shown in FIG. 2, between the bores, a damming wall 16 that integrates the lower half portions of the adjacent barrel portions 4 and 4 is formed so as to race up from the jacket bottom 15, and A point connection wall 17 is formed to integrate the upper portions of the matching barrel portions 4 and 4 with a small cross-sectional area.

  As shown in FIG. 2, the damming wall 16 having a shape that is long in the left and right and short in the front and rear is formed into a trapezoidal shape having upper and lower inclined side surfaces 18 and 19. The inclined side surfaces 18 and 19 may be formed as vertical side surfaces, and may be a rectangular damming wall 16 in the front-rear direction view. The cooling water that is about to flow into the inter-bore channels 9 and 10 is guided by the inclined side surfaces 18 and 19 so that the components of the flow that flows obliquely upward in the horizontal direction are promoted in the inter-bore channels 9 and 10. Become. In addition, the upper surfaces of the inter-bore channels 9 and 10 may be formed in a bowl-shaped curved ceiling surface 20, so that the flow between the upper and lower bores 9 and 10 is relatively promoted. It is configured.

  Between the upper and lower sides of the damming wall 16 and the point connection wall 17, an upper trapezoid trapezoidal lower rib wall 21 is formed so as to project from the barrel portion 4 in the front-rear direction. On the upper side of the point connection wall 17, an upper rib wall 22 is formed so as to project from the barrel portion 4 in the front-rear direction. The lower rib wall 21 and the upper rib wall 22 regulate the path width (front-rear width) of the inter-bore channels 9 and 10, and can achieve the effect of increasing the flow rate of the cooling water and the effect of guiding it upward.

  Further, a drill hole 3 c that vertically penetrates the cylinder ceiling wall 3 is formed in the upper left and right middle of the inter-bore channels 9 and 10 so as to open to the curved ceiling surface 20. This drill hole 3c allows flow from the top of the inter-bore channels 9, 10 to the cylinder head jacket (not shown), increasing the flow velocity in the inter-bore channels 9, 10 and increasing the cooling area. The cooling efficiency is increased.

  Thus, between the adjacent barrel portions 4 and 4 in the water jacket W, there is a damming wall 16 in the lower half, and the upper portion of the cylinder 2 has a cross-sectional area that is about half the depth of the main flow paths 7 and 8. Are formed in the inter-bore channels 9 and 10 in the state of The damming wall 16 and the point connecting wall 17 integrate the barrel portions 4 and 4 so that the cylinder block 1 can contribute to improvement in strength and rigidity.

[Embodiment 2]
As shown in FIG. 5B, among the four guide ribs h, the second and fourth ribs 12 and 14 may have a cooling structure having a configuration different from that of the first embodiment shown in FIG. . That is, the second guide rib 12 that has an arc shape along the circumferential direction of the second cylinder 2 as viewed in the vertical direction and projects from the first barrel portion 4 to the exhaust-side main flow path 8, and the third cylinder 2 as viewed in the vertical direction. The guide rib h includes a fourth guide rib 14 that has an arc shape along the circumferential direction and protrudes from the intermediate barrel portion 4 to the exhaust-side main flow path 8.

  The second guide rib 12 exerts a guide action for merging the cooling water flowing from the left to the right (from the intake side to the exhaust side) in the first inter-bore flow path 9 while guiding it to the exhaust-side main flow path 8 obliquely to the rear right. Is done. Similarly, the fourth guide rib 14 guides the cooling water flowing from the left to the right (from the intake side to the exhaust side) in the second inter-bore flow path 10 to join the exhaust-side main flow path 8 while guiding it diagonally rearward to the right. The effect is demonstrated.

Therefore, according to the guide ribs h (11 to 14) according to the second embodiment, the cooling water is taken into the inter-bore passages 9 and 10 from the intake-side main passage 7 and taken into the inter-bore passages 9 and 10. The flow in the water jacket W is controlled so that the cooling water flows out to both the exhaust side main flow dew 8 and the drill hole 3c.

Also in the water cooling structure of the second embodiment, the lateral protrusion amounts and heights of the third and fourth guide ribs 12 and 14 on the downstream side are the lateral protrusions of the corresponding first and second guide ribs 11 and 12 on the upstream side. It is set to be larger (longer) than the amount and height.

[Another Example]
Although not shown, any or all of the first to fourth guide ribs 11 to 14 may be configured as guide ribs h configured to protrude from the cylinder outer frame portion 5 to the main flow paths 7 and 8. . At this time, various changes can be set such that the guide rib h has a shape along the circumferential direction of the cylinder 2 as viewed in the axial direction of the cylinder 2, or a linear shape or a bent shape.

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder 4 Barrel part 5 Cylinder outer frame part 7 Intake side main flow path 8 Exhaust side main flow path 9,10 Flow path between bores 11-14 Guide rib W Water jacket h Guide rib

Claims (5)

A plurality of cylinders arranged in a cylinder block;
A water jacket formed around the plurality of cylinders;
The water jacket is formed between a pair of main flow paths formed in a state extending in the cylinder arrangement direction outside the cylinder, and an inter-bore flow formed between adjacent cylinders in a state of connecting the pair of main water channels. And roads,
A guide rib capable of guiding the cooling water flowing through the main channel to the channel between the bores is provided for each of the plurality of channels between the bores,
The plurality of guide ribs is a water-cooling structure for a multi-cylinder engine configured such that the protruding length in the direction intersecting the cylinder axis becomes longer toward the downstream guide rib in the coolant flow direction. A plurality of cylinders arranged in a cylinder block;
A water jacket formed around the plurality of cylinders;
The water jacket is formed between a pair of main flow paths formed in a state extending in the cylinder arrangement direction outside the cylinder, and an inter-bore flow formed between adjacent cylinders in a state of connecting the pair of main water channels. And roads,
A guide rib capable of guiding the cooling water flowing through the main channel to the channel between the bores is provided for each of the plurality of channels between the bores,
The plurality of guide ribs is a water-cooling structure of a multi-cylinder engine configured such that the downstream guide rib in the coolant flow direction has a longer length in the cylinder axial direction.   The water cooling structure for a multi-cylinder engine according to claim 1, wherein the guide rib is formed in a barrel portion that forms the cylinder in the cylinder block.   The water cooling structure for a multi-cylinder engine according to claim 1, wherein the guide rib is formed in a cylinder outer frame portion that surrounds the water jacket in the cylinder block.   The water cooling structure for a multi-cylinder engine according to any one of claims 1 to 4, wherein the guide rib has an arc shape along a cylinder bore.

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