JP6167838B2 - Engine cooling system - Google Patents

Description

  The present invention relates to an engine cooling apparatus in which engine cooling water circulates in a water jacket provided in a cylinder block and a cylinder head.

  2. Description of the Related Art Conventionally, a water jacket provided on a cylinder block so as to surround a cylinder bore wall of an engine and a water jacket provided on a cylinder head coupled to the cylinder block have engine cooling water in the water jacket. Cooling devices for circulating engines are well known. In order to improve the fuel efficiency performance and exhaust gas purification performance of the automobile, it is preferable to warm up the engine early by suppressing overcooling of the cylinder bore wall when the engine is cold.

  As a technique for that, the technique disclosed in Patent Document 1 can be adopted. That is, in Patent Document 1, a spacer member having a peripheral wall facing the cylinder bore wall in the vicinity of the cylinder bore wall is accommodated in the water jacket of the cylinder block, and flanges extending outward from the spacer member are provided on the upper and lower ends of the peripheral wall. It is disclosed. And, it is supposed that the cooling water flowing in the water jacket of the cylinder block is prevented from flowing between the peripheral wall and the cylinder bore wall by this scissors. Therefore, if this technique is used, the cooling water is prevented from flowing directly on the surface of the cylinder bore wall, so that heat is deprived from the cylinder bore wall and the engine is warmed up.

JP 2007-263120 A (paragraphs 0030 and 0031, FIG. 4)

  However, it cannot be said that the stagnation of the cooling water to the cylinder bore wall side is still sufficiently suppressed by the above-mentioned dredging.

  The present invention has been made in view of the above-described situation, and an object of the present invention is to provide an engine cooling device that can sufficiently prevent the coolant from flowing between the spacer member housed in the water jacket of the cylinder block and the cylinder bore wall. To do.

In order to solve the above-described problems, the present invention provides a first water jacket provided on a cylinder block so as to surround cylinder bore walls of a plurality of cylinders of an engine, and a cylinder head coupled to the upper surface of the cylinder block. A cooling device for a multi-cylinder engine having a second water jacket provided on the spacer, a spacer member housed in the first water jacket and having a peripheral wall facing the cylinder bore wall in close proximity, and the peripheral wall A flange portion extending outward in the cylinder bore radial direction from the peripheral wall, and a gasket interposed between the cylinder block and the cylinder head, the first water jacket and the first A communication hole communicating with the two water jackets, and provided in the cylinder block. An introduction part into which cooling water is introduced into the first water jacket from a position below the flange part, and a discharge part provided in the cylinder head and through which the cooling water is discharged from the second water jacket. provided, the height of the upper end of the spacer member is a spacer member in the lower position than the upper end of the first water jacket is disposed, between the upper end and the lower surface of the gasket of the spacer member A predetermined gap is formed, and the flange portion has a plurality of notches as a flow promoting portion that promotes the flow of the cooling water outside the peripheral wall of the spacer member to the communication hole in the first water jacket. together provided, the area excluding the respective notches is the flange portion formed so as to extend in the cylinder row direction, the communication hole, in the vertical direction as viewed Serial, characterized in that it is provided in a position overlapping with each notch (Claim 1).

  According to the present invention, the first water jacket provided in the cylinder block and the second water jacket provided in the cylinder head communicate with each other via the communication hole, and the cylinder block is connected to the first water jacket. Since the introduction part for introducing the cooling water is provided, and the cylinder head is provided with the discharge part for discharging the cooling water from the second water jacket, the cooling introduced from the introduction part to the first water jacket. When the water comes in the vicinity of the communication hole, a part of the water tries to flow into the second water jacket through the communication hole. That is, in the vicinity of the communication hole, there is a flow of cooling water from the first water jacket to the second water jacket (hereinafter referred to as “vertical flow in the vicinity of the communication hole”).

Under such circumstances, the peripheral wall of the spacer member accommodated in the first water jacket is close to and opposed to the cylinder bore wall, and a flange portion extending outward in the cylinder bore radial direction is provided on the upper portion of the peripheral wall. Therefore, the flange portion prevents the cooling water flowing outside the spacer member from the peripheral wall in the first water jacket from flowing from the upper side between the peripheral wall and the cylinder bore wall.

On the other hand, the flange portion is provided such that cooling water flowing outside the spacer member from the peripheral wall (hereinafter sometimes simply referred to as “outside of the peripheral wall”) flows from the lower side between the peripheral wall and the cylinder bore wall. It is suppressed as follows by the distribution promotion part (notch) . That is, the distribution promoting part has a function of promoting the flow of cooling water from the peripheral wall to the communication hole outside the spacer member (hereinafter referred to as “distribution promoting function”). Therefore, the vertical flow in the vicinity of the communication hole is strengthened outside the peripheral wall by the flow promoting function. Accordingly, the vertical flow in the vicinity of the communication hole is weakened inside the peripheral wall, that is, between the peripheral wall and the cylinder bore wall. For example, if the flow outside the peripheral wall is weak relative to the target amount of cooling water flowing from the first water jacket to the second water jacket, the flow inside the peripheral wall becomes strong to compensate for this, and the flow outside the peripheral wall If the flow is sufficient, the flow inside the peripheral wall almost stops. As a result, the flow promoting function of the flow promoting part almost stops the flow inside the peripheral wall, so that it is effective that the cooling water flowing outside the peripheral wall flows from the lower side between the peripheral wall and the cylinder bore wall. It is suppressed.

As described above, according to the present invention, since the wraparound of the cooling water to the cylinder bore wall side is suppressed on both the upper side and the lower side , the cooling water is interposed between the spacer member accommodated in the water jacket of the cylinder block and the cylinder bore wall. An engine cooling device that can sufficiently suppress the sneaking around is provided. Therefore, the engine can be warmed up early by suppressing overcooling of the cylinder bore wall when the engine is cold.

  In addition, according to the present invention, a communication hole that allows the first water jacket and the second water jacket to communicate with each other is preferably provided by using a gasket interposed between the cylinder block and the cylinder head. be able to.

  In the present invention, a vertical wall is erected from the outer surface of the peripheral wall continuously to the flange portion on the downstream side in the flow direction of the cooling water flowing in the circumferential direction outside the peripheral wall with respect to the flow promoting portion. (Claim 2).

  According to this configuration, the cooling water flowing in the first water jacket hits the vertical wall, and a part thereof is converted into a flow toward the communication hole. Strengthened.

In the present invention, with respect to mutually boundary of the cylinder bores of adjacent cylinders, the outer peripheral wall on the upstream side of the flow direction of the cooling water flowing in the circumferential direction, from the outer surface of the peripheral wall in succession to the flange portion It is preferable that a barrier is erected (claim 3).

  According to this configuration, the cooling water flowing in the first water jacket hits the barrier, and the momentum of the flow is weakened. Therefore, the momentum of the cooling water hitting the boundary portion of the cylinder bore on the downstream side of the barrier is also reduced. Also weakened. For this reason, when the cooling water hits the boundary of the cylinder bore, the momentum of the cooling water toward the cylinder head becomes weak, so that it is further suppressed that the cooling water goes over the flange portion to the cylinder bore wall side. The

In the present invention, it is preferable that a second flange portion extending outward from the peripheral wall in the cylinder bore radial direction is provided below the flange portion of the peripheral wall .

  According to this configuration, since the flange portion is provided in two stages, this also further suppresses the cooling water from passing over the flange portion to the cylinder bore wall side.

In the present invention, the upper Symbol promote distribution unit is preferably provided for a plurality of cylinder bores of the downstream side of the flow direction of the cooling water flowing outside of the circumferential wall in the circumferential direction of the cylinder bore (claim 5) .

  The flow of the cooling water in the first water jacket is strong on the upstream side near the introduction portion of the cooling water, and weak on the downstream side far from the introduction portion of the cooling water. Therefore, the vertical flow in the vicinity of the communication hole is strong in the upstream cylinder bore and weak in the downstream cylinder bore. Therefore, according to this configuration, since the flow promoting function of the flow promoting portion is exerted on the downstream cylinder bore in which the longitudinal flow in the vicinity of the communication hole is relatively weak, the overcooling of the cylinder bore wall is suppressed. For cylinder bores that need more countermeasures, the sneaking of cooling water to the cylinder bore wall side is well suppressed.

  In the present invention, a discharge part that is provided in the cylinder block and from which the cooling water is discharged from the first water jacket, and a cooling water introduced from the introduction part to the first water jacket, pass through the communication hole. Through the first water jacket, circulates through the second water jacket and is discharged from the discharge portion of the cylinder head, and cooling water introduced from the introduction portion to the first water jacket. Flows into the second water jacket through the communication hole, flows through the second water jacket and is discharged from the discharge portion of the cylinder head, and flows through the first water jacket and discharges the cylinder block. A second path that is discharged from the section, and when the engine temperature is lower than a predetermined warm-up determination temperature, the flow path of the cooling water is the first path. Is switched to the road, it is preferable that when the temperature of the engine is equal to or greater than the warm-up determination temperature is switched to said second path (claim 6).

  According to this configuration, when the engine temperature is lower than the warm-up determination temperature, only the cylinder head is cooled by the first path through which the cooling water flows through the second water jacket, and the engine temperature is increased. After warming up above the machine determination temperature, in addition to the cylinder head, the cylinder block is also cooled by the second path through which the coolant flows through the first water jacket and the second water jacket. Therefore, when the engine is cold, the circulation promotion function of the above-described circulation promotion unit suppresses the wrapping of the cooling water to the cylinder bore wall side, thereby suppressing the overcooling of the cylinder bore wall and the cooling water. The supercooling of the cylinder bore wall is also suppressed by switching the flow path to the first path. As a result, the engine can be warmed up more quickly.

  As described above, the present invention provides an engine cooling device that can sufficiently prevent the cooling water from flowing between the spacer member accommodated in the water jacket of the cylinder block and the cylinder bore wall. It contributes to the development and improvement of the technology of the engine cooling device in which the cooling water circulates in the water jacket.

1 is a block diagram showing an overall configuration of an engine cooling device according to an embodiment of the present invention. It is a block diagram which shows the operating state of the said cooling device according to head combustion chamber wall surface temperature, (a) is at the time of cold, (b) is before warming up, (c) is after warming up, (d) is After warm-up is complete. It is a disassembled perspective view of the cylinder block of the said engine including a gasket. It is a top view of the said cylinder block. It is sectional drawing along the VV line of FIG. It is a side view by the side of the intake of the water jacket spacer used for the said cooling device. It is a side view of the exhaust side of the water jacket spacer. It is a side view by the side of the 1st cylinder of the water jacket spacer. It is the perspective view seen from the intake side by the side of the 1st cylinder of the said water jacket spacer. It is the perspective view seen from the exhaust side of the 1st cylinder side of the said water jacket spacer.

(1) Overall configuration [1-1]
FIG. 1 is a block diagram showing an overall configuration of an engine cooling device 1 according to the present embodiment. The engine 2 includes a cylinder block 3 and a cylinder head 4 coupled to the cylinder block 3, and four cylinders (first to fourth cylinders # 1 to # 4 shown in FIG. 3) are arranged in the crankshaft direction (FIG. 1). The cross-flow type in-line four-cylinder diesel engine is arranged in a row in the left-right direction with respect to the cylinder block 3 and the cylinder head 4. The engine 2 has an engine room (not shown) provided at the front of the vehicle, in which the cylinder row faces the vehicle width direction, the intake side (IN) faces the front in the vehicle front-rear direction, and the exhaust side (EX) Is mounted so that the cylinder axis of each cylinder faces the vertical direction.

  In FIG. 1, since the cylinder block 3 is viewed from above and the cylinder head 4 is viewed from below, the positional relationship between the intake side and the exhaust side between the cylinder block 3 and the cylinder head 4 is described. Is reversed.

  The cylinder block 3 includes a block-side water jacket 33, an introduction hole 36 through which engine cooling water (hereinafter simply referred to as “cooling water”) is introduced into the water jacket 33, and a block from which the cooling water is discharged from the water jacket 33. A side discharge hole 37 is provided. The cylinder head 4 is provided with a head side water jacket 61 and a head side discharge hole 62 through which cooling water is discharged from the water jacket 61.

  The introduction hole 36 is provided with a water pump (WP) 5 for supplying cooling water to the water jackets 33 and 61. The water pump 5 is a mechanical water pump that is passively driven by the rotation of the engine 2.

[1-2]
The cooling device 1 includes first to fourth flow paths 11 to 14 for circulating cooling water through the water jackets 33 and 61.

  The first flow path 11 connects the head side discharge hole 62 and the introduction hole 36 via the flow path switching unit 6 and the water pump 5. The first flow path 11 includes a water temperature sensor 102 for detecting the temperature of the cooling water, a high pressure EGR valve (HP EGR / V) 21, an electric throttle 22, a thermostat valve 6a of the flow path switching unit 6, and a water pump 5. Go through in order. The water temperature sensor 102 is disposed in the head side discharge hole 62. The thermostat valve 6a circulates cooling water only through the first flow path 11 when the first to third control valves 6b to 6d are normal, and protects the engine 2 when the first to third control valves 6b to 6d are abnormal. Therefore, the cooling water is also circulated through the second flow path 12.

  The second flow path 12 connects the head side discharge hole 62 and the introduction hole 36 via the flow path switching unit 6 and the water pump 5. The second flow path 12 includes a water temperature sensor 102, an idle stop water pump (WP) 23, an air conditioning heater core 24, a low pressure EGR cooler (LP EGR / C) 25, a low pressure EGR valve (LP EGR / V) 26, a flow It passes through the first control valve 6b of the path switching unit 6 and the water pump 5 in this order. The idle stop water pump 23 is an electric water pump used when the engine 2 is temporarily stopped during the idle stop. The low pressure EGR cooler 25 and the low pressure EGR valve 26 are disposed in the second flow path 12 in parallel with each other.

  The third flow path 13 connects the block-side discharge hole 37 and the introduction hole 36 via the flow path switching unit 6 and the water pump 5. The third flow path 13 includes an engine oil cooler (O / C) 27, an automatic transmission hydraulic oil warmer (ATF / W) 28, a second control valve 6 c of the flow path switching unit 6, and the water pump 5. Go through in this order. The engine oil cooler 27 is disposed in the block side discharge hole 37.

  The fourth flow path 14 connects the head side discharge hole 62 and the introduction hole 36 via the flow path switching unit 6 and the water pump 5. The fourth flow path 14 passes through the water temperature sensor 102, the radiator 7, the third control valve 6d of the flow path switching unit 6, and the water pump 5 in this order.

[1-3]
The cooling device 1 includes an ECU 100. The ECU 100 is a microprocessor having a known configuration including a CPU, a ROM, a RAM, and the like. The ECU 100 receives detection signals from the water temperature sensor 102, the engine speed sensor 103 that detects the engine speed, and the fuel injection quantity sensor 104 that detects the fuel injection quantity, and is determined from the engine speed and the fuel injection quantity. 2 is used to predict the temperature of the wall of the combustion chamber on the cylinder head 4 side of the engine 2 (head combustion chamber wall surface temperature), and the first to third control valves 6b according to the predicted head combustion chamber wall surface temperature. Control ~ 6d. Note that the temperature of the cooling water may be simply used, and the detection target is not limited as long as it can be controlled based on the temperature of the engine.

  2A to 2D are block diagrams showing the operating state of the cooling device 1 in accordance with the head combustion chamber wall surface temperature.

  First, when the engine 2 is cold, the ECU 100 closes all the control valves 6b to 6d. Thereby, as shown by a thick line in FIG. 2A, the cooling water is circulated only in the first flow path 11. Cooling water introduced from the introduction hole 36 into the block-side water jacket 33 by the water pump 5 flows into the head-side water jacket 61 through communication holes 52, 53a to 53f (see FIG. 3), which will be described later. It flows through the jacket 61 and is discharged from the head side discharge hole 62.

  Since the first flow path 11 does not pass through the radiator 7 and almost no cooling water flows through the block-side water jacket 33, the temperature of the cylinder block 3 gradually increases, and warming up of the engine 2 is promoted. On the other hand, since a small amount of cooling water flows through the head-side water jacket 61, local heating of the wall surface of the combustion chamber on the cylinder head 4 side is prevented.

  Furthermore, since cooling water flows through the high pressure EGR valve 21 and the electric throttle 22, the high pressure EGR valve 21 is appropriately cooled immediately after the engine 2 is started, and when the electric throttle 22 is frozen, it is thawed.

  Let the cooling water flow path realized at this time be the cold time path K1.

  Next, when the head combustion chamber wall surface temperature becomes equal to or higher than a predetermined first determination temperature (for example, 150 ° C.), the ECU 100 opens the first control valve 6 b while the engine 2 is warming up. As a result, the cooling water is circulated through the second flow path 12 in addition to the first flow path 11 as indicated by a thick line in FIG. Cooling water introduced from the introduction hole 36 into the block-side water jacket 33 by the water pump 5 flows into the head-side water jacket 61 through the communication holes 52, 53a to 53f, and circulates through the head-side water jacket 61. It is discharged from the side discharge hole 62.

  The second flow path 12 also does not pass through the radiator 7 and the cooling water hardly flows through the block-side water jacket 33, so that the warm-up of the engine 2 is continuously promoted.

  Further, since the cooling water flows through the air conditioning heater core 24, the low pressure EGR cooler 25, and the low pressure EGR valve 26, the heating performance is ensured during the warm-up of the engine 2, and the low pressure EGR cooler 25 and the low pressure EGR valve 26 are appropriately set. To be cooled.

  The coolant flow path realized at this time is defined as a pre-warm-up path K2.

  The cold-time path K1 shown in FIG. 2A and the pre-warm-up path K2 shown in FIG. 2B correspond to the “first path” described in the claims.

  Next, after the engine 2 is warmed up, specifically, a predetermined second determination temperature in which the head combustion chamber wall surface temperature is higher than the first determination temperature (corresponding to “warm-up determination temperature” in the claims). If it becomes above, ECU100 will open the 2nd control valve 6c. As a result, the cooling water is circulated through the third flow path 13 in addition to the first and second flow paths 11 and 12 as indicated by a thick line in FIG. Cooling water introduced from the introduction hole 36 into the block-side water jacket 33 by the water pump 5 flows into the head-side water jacket 61 through the communication holes 52, 53a to 53f, and circulates through the head-side water jacket 61. In addition to being discharged from the side discharge hole 62, the second control valve 6 c is opened, whereby the block side water jacket 33 is circulated and discharged from the block side discharge hole 37.

  In the third flow path 13, since the cooling water also flows through the block-side water jacket 33, the cylinder block 3 is also cooled to some extent. However, since the third flow path 13 also does not pass through the radiator 7, the warm-up of the engine 2 proceeds.

  Furthermore, since the coolant flows through the oil cooler 27 and the hydraulic oil warmer 28, the engine oil is appropriately cooled after the engine 2 is warmed up, and the hydraulic oil in the automatic transmission is appropriately heated. As a result, the viscosity of the hydraulic oil is reduced, the sliding resistance is reduced, and fuel efficiency is improved.

  Let the cooling water flow path realized at this time be a warm-up path K3.

  When the warm-up of the engine 2 is completed, specifically, when the head combustion chamber wall surface temperature becomes equal to or higher than a predetermined third determination temperature higher than the second determination temperature, the ECU 100 opens the third control valve 6d. To do. Thereby, as shown with a thick line in FIG.2 (d), in addition to the 1st-3rd flow paths 11-13, a cooling water is circulated also to the 4th flow path 14. FIG. Cooling water introduced from the introduction hole 36 into the block-side water jacket 33 by the water pump 5 flows into the head-side water jacket 61 through the communication holes 52, 53a to 53f, and circulates through the head-side water jacket 61. In addition to being discharged from the side discharge hole 62, the second control valve 6 c is opened, whereby the block side water jacket 33 is circulated and discharged from the block side discharge hole 37.

  Since the fourth flow path 14 passes through the radiator 7, the head combustion chamber wall surface temperature is lowered by the radiator 7, and the engine 2 after warm-up is maintained at a predetermined temperature.

  The flow path of the cooling water realized at this time is defined as a post-warm-up path K4.

  The warm-up path K3 shown in FIG. 2 (c) and the warm-up completion path K4 shown in FIG. 2 (d) correspond to the “second path” described in the claims.

  As described above, the ECU 100 closes all the first to third control valves 6b to 6d when the engine 2 is cold, and opens the first to third control valves 6b to 6d as the head combustion chamber wall surface temperature rises. By sequentially opening the valves, the cylinders # 1 to # 4, the cylinder block 3, the cylinder head 4, and the auxiliary machines 21 to 28 are appropriately cooled or heated according to the head combustion chamber wall surface temperature.

  In the above, the ECU 100 uses the predicted value as the head combustion chamber wall surface temperature. However, instead of this, the ECU 100 may use the coolant temperature detected by the water temperature sensor 102.

(2) Cylinder block [2-1]
FIG. 3 is an exploded perspective view of the cylinder block 3 including the gasket 50, and FIG. 4 is a plan view of the cylinder block 3.

  The cylinder block 3 includes a cylinder block body 30 and a water jacket spacer 40 accommodated in the block-side water jacket 33. The cylinder block body 30 is provided with cylinder bores 32 of the first to fourth cylinders # 1 to # 4 arranged in series so that the cylinder axis faces the vertical direction. In the present embodiment, the first cylinder # 1 to the fourth cylinder # 4 are arranged in order from left to right when the cylinder block 3 is viewed from the intake side. Hereinafter, the side where the first cylinder # 1 is located is the left, and the side where the fourth cylinder # 4 is located is the right.

  The cylinder block main body 30 is provided with a block-side water jacket 33 so as to surround a cylinder bore wall 32a connecting the four cylinder bores 32. The block-side water jacket 33 is an endless groove formed so as to continuously open on the upper surface 31 of the cylinder block body 30. The block-side water jacket 33 has an exhaust-side flow path 33 e that passes through the exhaust side of the cylinder block 3 and an intake-side flow path 33 i that passes through the intake side of the cylinder block 3.

  The introduction hole 36 through which the cooling water is introduced into the block-side water jacket 33 is disposed on the intake side of the left end portion of the cylinder block body 30. The downstream portion 36a of the introduction hole 36 is inclined so that the coolant hits the cylinder bore wall 32a of the first cylinder # 1 at a relatively shallow angle in plan view from the intake side. The block-side discharge hole 37 through which the cooling water is discharged from the block-side water jacket 33 is disposed on the intake side (the intake side of the second cylinder # 2) at the substantially central portion of the cylinder row in the cylinder block body 30.

  The head side discharge hole 62 through which the cooling water is discharged from the head side water jacket 61 is disposed at the right end of the cylinder head 4 (see FIG. 1).

[2-2]
The cylinder head 4 is coupled to the upper surface 31 of the cylinder block body 30 via a gasket 50 (see FIG. 5). A plurality of screw holes 38 into which a head bolt (not shown) for connecting the cylinder head 4 can be screwed are opened on the upper surface 31 of the cylinder block body 30. Hereinafter, the side where the cylinder block 3 is located is the lower side, and the side where the cylinder head 4 is located is the upper side.

  The gasket 50 is a metal sheet gasket in which a plurality of metal plates are overlapped and a plurality of places are integrated by caulking. The overall shape of the gasket 50 is formed so as to correspond to the upper surface 31 of the cylinder block body 30.

  In other words, the gasket 50 is provided with four circular holes 51 having the same diameter at positions corresponding to the four cylinder bores 32 of the cylinder block body 30, and the same number of head bolt insertion holes at positions corresponding to the plurality of screw holes 38. 54 is provided.

  The gasket 50 is provided with a plurality of communication holes 52, 53a to 53f that allow the block-side water jacket 33 and the head-side water jacket 61 to communicate with each other. The three first communication holes 52 are arranged at the left end portion of the gasket 50. Out of the six second communication holes 53a to 53f, the four second communication holes 53a to 53d on the exhaust side are arranged on the exhaust side of the first to fourth cylinders # 1 to # 4 in the gasket 50, and the two on the intake side. The two second communication holes 53e and 53f are arranged on the intake side of the second cylinder # 2 and the third cylinder # 3 in the gasket 50.

  Here, as clearly shown in FIG. 4, the first communication hole 52 is formed larger than the second communication holes 53 a to 53 f, and the second communication hole 53 a to 53 f is the first communication hole on the intake side of the second cylinder # 2. The second communication hole 53e and the second communication hole 53f on the intake side of the third cylinder # 3 are formed the largest, the second communication hole 53c on the exhaust side of the third cylinder # 3 is formed slightly smaller, and the second cylinder # 2 The exhaust side second communication hole 53b of the first cylinder # 1 is further reduced, and the exhaust side second communication hole 53a of the first cylinder # 1 and the exhaust side second communication hole 53d of the fourth cylinder # 4 are formed to be the smallest. Yes. This is because the amount of cooling water introduced from the introduction hole 36 to the block-side water jacket 33 through the first communication hole 52 is optimized, or the cooling water flowing from the block-side water jacket 33 to the head-side water jacket 61 is adjusted. This is in consideration of equalization of the amount of passage through the second communication holes 53a to 53f.

  When the cylinder head 4 is coupled to the cylinder block 3 with the gasket 50 interposed therebetween, the periphery of the circular hole 51 and the periphery of the insertion hole 54 are sealed by the elastic restoring force of the gasket 50. As a result, leakage of gas from the combustion chambers of the cylinders # 1 to # 4 and leakage of cooling water from the water jackets 33 and 61 are prevented. At this time, all of the communication holes 52, 53a to 53f are located above the block-side water jacket 33 and below the head-side water jacket 61 (see FIG. 5). Thus, the communication holes 52 and 53a to 53f communicate the block-side water jacket 33 and the head-side water jacket 61 with each other.

(3) Water jacket spacer [3-1]
FIG. 5 is a cross-sectional view taken along line VV in FIG. That is, the longitudinal section including the cylinder axis of the third cylinder # 3 is viewed from the first cylinder # 1 side. In FIG. 5, the inner wall portions 34e, 34i are the inner wall portions of the cylinder block 3 of the exhaust side flow passage 33e and the intake side flow passage 33i of the block side water jacket 33, and the outer wall portions 35e, 35i are the outer wall portions. To do. The inner wall portions 34e and 34i can also be called cylinder bore walls 32a.

  A water jacket spacer (hereinafter simply referred to as “spacer”) 40 is accommodated in the block-side water jacket 33. The spacer 40 has a peripheral wall 41 that faces and opposes the cylinder bore wall 32a (or the inner wall portions 34e and 34i of the water jacket 33). The peripheral wall 41 extends in the cylinder axial direction (vertical direction with respect to FIG. 5), and has a plate thickness (that is, a concave groove) that is accommodated in the water jacket 33 with a predetermined distance from the inner wall portions 34e and 34i and the outer wall portions 35e and 35i. And a height that does not protrude from the upper surface 31 of the cylinder block body 30 (that is, a height that is lower than the depth of the water jacket 33 that is a concave groove). ing. The peripheral wall 41 is an endless cylindrical member in which four circles are slightly overlapped and connected in plan view along the outer periphery of the cylinder bore wall 32a (see FIG. 3).

  The space between the peripheral wall 41 (more specifically, the outer surface of the peripheral wall 41) and the outer wall portions 35e, 35i of the water jacket 33 is relatively wide, and the peripheral wall 41 (more specifically, the inner surface of the peripheral wall 41) and the inner wall portions 34e, 34i of the water jacket 33 are. The distance from the (cylinder bore wall 32a) is relatively narrow. That is, the space outside the spacer 40 from the peripheral wall 41 in the water jacket 33 is wider and larger in volume than the inner space. Therefore, in the water jacket 33, the outer side of the peripheral wall 41 has a larger flow path cross-sectional area than the inner side, and the flow resistance is smaller. Therefore, the cooling water mainly flows in the space outside the peripheral wall 41 in the water jacket 33.

  A liner 39 having wear resistance is integrally formed on the inner peripheral surface of the cylinder bore wall 32a.

[3-2]
6 is a side view on the intake side of the spacer 40, FIG. 7 is a side view on the exhaust side, FIG. 8 is a side view on the left side, FIG. 9 is a perspective view seen from the left intake side, and FIG. It is the perspective view seen from the exhaust side of the left side.

<First flange>
As illustrated (for example, FIG. 9), a first flange 42 extending outward of the spacer 40 is provided at the upper end portion of the peripheral wall 41. The 1st flange 42 is provided over the perimeter of the surrounding wall 41 except the left end part of the surrounding wall 41, and the flow promotion part 46 mentioned later.

  As shown in FIG. 4, the first flange 42 extends to a position close to the outer wall portions 35 e and 35 i of the water jacket 33. That is, the first flange 42 closes the space outside the spacer 40 from the peripheral wall 41 of the water jacket 33 at a relatively upper position of the water jacket 33. The first flange 42 prevents the cooling water flowing outside the peripheral wall 41 in the water jacket 33 from getting over the first flange 42 and flowing around between the peripheral wall 41 and the cylinder bore wall 32a from the upper side of the peripheral wall 41. belongs to.

  The reason why the first flange 42 is not provided at the left end portion of the peripheral wall 41 is that a part of the cooling water introduced from the introduction hole 36 to the block-side water jacket 33 passes through the first communication hole 52 and passes through the head-side water jacket. This is because it does not hinder the flow into 61.

  Similarly, the reason why the first flange 42 is not provided in the flow promoting portion 46 is that a part of the cooling water flowing in the block-side water jacket 33 passes through the second communication holes 53b to 53f (excluding 53a). This is because it does not hinder the flow into the head-side water jacket 61. This will be further described later.

<Second flange>
As shown in the figure (for example, FIG. 9), a second flange 43 extending outward from the spacer 40 is provided below the first flange 42 of the peripheral wall 41 in parallel with the first flange 42 (excluding an inclined portion 43a described later). ) Is provided. Similarly to the first flange 42, the second flange 43 is not provided on the left end portion of the peripheral wall 41 and the flow promoting portion 46. Furthermore, the second flange 43 is not provided at the right end portion of the peripheral wall 41, the exhaust side of the fourth cylinder # 4, and a part of the intake side of the fourth cylinder # 4.

  The second flange 43 also extends to a position close to the outer wall portions 35e and 35i of the water jacket 33, and closes the space outside the spacer 40 from the peripheral wall 41 of the water jacket 33 at a relatively upper position of the water jacket 33. . The second flange 43 prevents the cooling water flowing outside the peripheral wall 41 in the water jacket 33 from getting over the second flange 43 and flowing around from the upper side of the peripheral wall 41 between the peripheral wall 41 and the cylinder bore wall 32a. belongs to.

  The distance between the first flange 42 and the second flange 43 is set to be relatively wide on the exhaust side and relatively narrow on the intake side. The right end portion on the intake side of the second flange 43 is connected to the first flange 42 via an inclined portion 43a.

<Third flange>
As illustrated (for example, FIG. 10), a third flange 43 z extending outward of the spacer 40 is provided in the vicinity of the lower end of the peripheral wall 41 on the exhaust side. The third flange 43z has a shorter outward extension distance than the first flange 42 and the second flange 43. The third flange 43z suppresses cooling water flowing outside the peripheral wall 41 in the water jacket 33 from getting over the third flange 43z and flowing between the peripheral wall 41 and the cylinder bore wall 32a from the lower side of the peripheral wall 41. Is for.

<Distribution Promotion Department>
As shown (for example, FIGS. 6 and 7), the first flange 42 and the second flange 43 are provided with a flow promoting portion 46. In this embodiment, the distribution promotion part 46 is provided in five places. That is, they are provided on the exhaust side of the second cylinder # 2, the exhaust side of the third cylinder # 3, the exhaust side of the fourth cylinder # 4, the intake side of the second cylinder # 2, and the intake side of the third cylinder # 3. ing.

  Specifically, the distribution promoting part 46 is configured by notches formed in the first flange 42 and the second flange 43. As is clear from FIG. 4, for example, on the exhaust side of the second cylinder # 2, the first flange 42 and the second flange 43 are connected to the right side portion of the second communication hole 53b from the right side in the plan view. A notch 46a is formed. Similarly, on the exhaust side of the third cylinder # 3, a notch 46b is formed in the first flange 42 and the second flange 43 from a position directly below the second communication hole 53c to the right side in a plan view. . Further, on the exhaust side of the fourth cylinder # 4, a notch 46c is formed in the first flange 42 from a position directly below the second communication hole 53d to a right side portion in plan view.

  On the other hand, on the intake side of the second cylinder # 2, a notch 46d is formed in the first flange 42 and the second flange 43 from right below the second communication hole 53e to the right side portion and the left side portion in plan view. Has been. Similarly, on the intake side of the third cylinder # 3, cutouts 46e are formed in the first flange 42 and the second flange 43 from a position directly below the second communication hole 53f to a right side portion and a left side portion in plan view. Is formed.

  Thereby, since the first flange 42 and the second flange 43 are not provided in the portion where the distribution promoting portion 46 is provided, the space outside the peripheral wall 41 of the water jacket 33 by the first flange 42 and the second flange 43. Is not blocked at a relatively upper position. Therefore, the first flange 42 and the second flange 43 cause a part of the cooling water flowing in the water jacket 33 to flow into the head-side water jacket 61 through the second communication holes 53b to 53f (excluding 53a). There is no hindrance. Therefore, the flow of cooling water outside the peripheral wall 41 in the water jacket 33 to the second communication holes 53b to 53f (excluding 53a) is promoted. That is, the distribution promotion function of the distribution promotion unit 46 is exhibited.

<Vertical wall>
As shown in the figure (for example, FIG. 10), a vertical wall 44a is provided at the upper part of the peripheral wall 41 on the right side of the exhaust-side circulation promoting portion 46 of the second cylinder # 2. The vertical wall 44 a is disposed adjacent to the second communication hole 53 b in a plan view, and is provided on the outer surface of the peripheral wall 41 so as to be continuous with the first flange 42 and the second flange 43.

  Similarly, a vertical wall 44b is provided in the upper part of the peripheral wall 41 on the right side of the exhaust side circulation promoting portion 46 of the third cylinder # 3. The vertical wall 44 b is disposed in the vicinity of the second communication hole 53 c in plan view, and is provided on the outer surface of the peripheral wall 41 so as to be continuous with the first flange 42 and the second flange 43.

<Barrier>
As shown in the figure (for example, FIGS. 6 and 7), at the upper part of the peripheral wall 41, the exhaust side of the first cylinder # 1, the exhaust side of the second cylinder # 2, the exhaust side of the third cylinder # 3, the first cylinder # Barriers 45a, 45b, 45c, 45d, 45e, and 45f are provided on the intake side of the first cylinder, the intake side of the second cylinder # 2, and the intake side of the fourth cylinder # 4, respectively. These barriers 45 a to 45 f are provided on the outer surface of the peripheral wall 41 so as to be continuous with the first flange 42 and the second flange 43.

  Specifically, the exhaust-side barrier 45a of the first cylinder # 1 is a boundary (an indentation inside the spacer 40) between the cylinder bore 32 of the first cylinder # 1 and the cylinder bore 32 of the second cylinder # 2. Bottom) and the expansion portion (the top of the convex portion on the outside of the spacer 40) on the exhaust side of the cylinder bore 32 of the first cylinder # 1.

  Similarly, the exhaust-side barrier 45b of the second cylinder # 2 includes an exhaust-side boundary between the cylinder bore 32 of the second cylinder # 2 and the cylinder bore 32 of the third cylinder # 3, and the cylinder bore 32 of the second cylinder # 2. The exhaust-side barrier 45c of the third cylinder # 3 is located between the cylinder-side bore 32 of the third cylinder # 3 and the cylinder-bore 32 of the fourth cylinder # 4. And the expansion portion on the exhaust side of the cylinder bore 32 of the third cylinder # 3.

  On the other hand, the intake side barrier 45d of the first cylinder # 1 has a boundary portion between the cylinder bore 32 of the first cylinder # 1 and the cylinder bore 32 of the second cylinder # 2, and the cylinder bore 32 of the first cylinder # 1. The intake side barrier 45e of the second cylinder # 2 is disposed between the intake side expansion portion and the intake side boundary between the cylinder bore 32 of the second cylinder # 2 and the cylinder bore 32 of the third cylinder # 3. The intake side barrier 45f of the fourth cylinder # 4 is disposed between the cylinder bore 32 of the third cylinder # 3 and the fourth cylinder # 4. It is disposed between the intake side boundary with the cylinder bore 32 and the intake side expansion portion of the cylinder bore 32 of the fourth cylinder # 4.

<Second barrier>
As shown in the figure (for example, FIG. 8), second barriers 45x and 45y are provided on the exhaust side and the intake side of the first cylinder # 1 above the peripheral wall 41, respectively. The second barriers 45 x and 45 y are provided on the outer surface of the peripheral wall 41 so as to be continuous with the first flange 42 and the second flange 43.

  Specifically, the second barrier 45x on the exhaust side of the first cylinder # 1 is disposed on the left end side of the cylinder row with respect to the exhaust side expansion portion of the cylinder bore 32 of the first cylinder # 1, and the first cylinder # 1 The second barrier 45y on the intake side is disposed on the left end portion side of the cylinder row with respect to the expansion portion on the intake side of the cylinder bore 32 of the first cylinder # 1.

  These second barriers 45x and 45y weaken the momentum of colliding with the outer wall portions 35e and 35i of the cooling water exhaust side flow path 33e and the intake side flow path 33i immediately after being introduced into the block side water jacket 33, and the cooling water is This is to prevent the outer wall portions 35e and 35i from going around the cylinder bore wall 32a beyond the first flange 42 when colliding with the outer wall portions 35e and 35i.

<Slope flange>
As illustrated (for example, FIG. 8), a slope-shaped flange 47 a is provided at the left end portion of the peripheral wall 41. The reason why such a slope-shaped flange 47a is provided is as follows.

  As shown in FIG. 3, the lower surface of the left end portion of the block-side water jacket 33 is formed in an inclined shape that smoothly rises from the side where the introduction hole 36 is arranged, that is, from the intake side toward the exhaust side, and then descends. As a result, the flow of the cooling water introduced into the block-side water jacket 33 from the introduction hole 36 is directed upward, that is, through the first communication hole 52 toward the head-side water jacket 61 by the rising portion. An inclined guide portion 47 is configured (see FIG. 4).

  Corresponding to the inclined guide portion 47, the lower end portion of the left end portion of the peripheral wall 41 is formed in an inclined shape that smoothly rises from the intake side toward the exhaust side and then descends. Furthermore, a slope-like flange 47a extending outward from the spacer 40 is provided at the rising portion of the lower end portion of the peripheral wall 41 formed in an inclined shape. Therefore, the slope-shaped flange 47a smoothly rises from the lower end portion of the peripheral wall 41 to the vicinity of the center portion in the cylinder axial direction from the intake side to the exhaust side.

<Others>
As shown in FIG. 6 (for example, FIG. 6), on the intake side of the peripheral wall 41, for a cold region, which is a notch for inserting a cold region heater (not shown) into a part of the lower portion of the fourth cylinder # 4. A heater insertion portion 49a is provided.

  As shown (for example, FIG. 6), on the intake side of the peripheral wall 41, a part of the lower part of the first cylinder # 1, a part of the lower part of the second cylinder # 2, and a part of the lower part of the third cylinder # 3 are covered. In addition, a discharge-corresponding deficient portion 49b which is a notch for ensuring smooth discharge of the cooling water from the block-side discharge hole 37 by enlarging the cross-sectional area of the water jacket 33 is provided.

[3-3]
Since the spacer 40 is accommodated in the block-side water jacket 33, the spacer 40 is formed of a resin having heat resistance that can withstand the high temperature inside the cylinder block 3 and rigidity that does not cause deformation or breakage due to the water pressure of the cooling water. ing. Examples of resins that can be used include polyamide-based thermoplastic resins (PA66, PPA, etc.), olefin-based thermoplastic resins (PP, etc.), polyphenylene sulfide-based thermoplastic resins (PPS, etc.), and the like. One of them can be used alone or in combination of two or more. Moreover, you may mix | blend reinforcement materials, such as glass fiber, as needed. Such a resin spacer 40 can be integrally molded by an injection molding technique.

[3-4]
Next, the main function of the spacer 40 will be described.

  For the explanation of the operation of the spacer 40, an arrow R1 (FIGS. 3 and 4) indicates a flow of cooling water introduced from the introduction hole 36 into the block-side water jacket 33, and an arrow R2 (FIGS. 3 and 4). Indicates the flow of the cooling water discharged from the block side discharge hole 37, and the arrow R3 (FIG. 4) indicates the flow of the cooling water toward the cylinder bore wall 32a of the first cylinder # 1, and the arrow R4 (FIG. 6 and FIG. 6). FIG. 8) shows the flow of cooling water toward the intake side flow path 33i and passing through the intake side flow path 33i, and the arrow R5 (FIG. 8) shows the flow of cooling water toward the exhaust side flow path 33e, Arrow R6 (FIG. 8) indicates the flow of the cooling water directed upward by the inclined guide portion 47, arrow R7 (FIG. 8) indicates the flow of the cooling water toward the first flow hole 52, and arrow R8 (FIG. 8). 7 and 8) passed through the tilt guide 47. The flow of the cooling water toward the exhaust side flow path 33e and passing through the exhaust side flow path 33e is shown, and an arrow R9 (FIG. 6) makes a U-turn after passing through the exhaust side flow path 33e and makes an intake side flow path. The flow of the cooling water which passes 33i is shown, arrow R10 (FIG. 6) shows the flow of the cooling water which goes to the block side discharge hole 37, arrows R11-R14 (FIG. 7), and arrows R15, R16 (FIG. 6). These show the flow of the cooling water toward the second circulation holes 53a to 53f on the exhaust side and the intake side.

<I>
The cooling water is first introduced into the left end portion of the block-side water jacket 33 (arrows R1 and R3), a part flows into the intake-side flow path 33i (arrow R4), and the remaining part flows into the exhaust-side flow path 33e (arrow). R5, R6, R8). The coolant that has flowed into the intake side flow path 33i flows through the intake side of the first cylinder # 1 and reaches the block side discharge hole 37 disposed on the intake side of the second cylinder # 2 (arrow R4). The cooling water that has flowed into the exhaust side flow path 33e flows through the exhaust side of the first to fourth cylinders # 1 to # 4 (arrow R8), and after making a U-turn, the fourth cylinder # 4 and the third cylinder # 3. It circulates on the intake side and reaches the block side discharge hole 37 (arrow R9).

  While flowing through the block-side water jacket 33, the cooling water passes through the first communication hole 52 and the second communication holes 53a to 53f and flows into the head-side water jacket 61 (arrows R7, R11 to R16). ). The cooling water flowing into the head-side water jacket 61 flows through the head-side water jacket 61 and reaches the head-side discharge hole 62 disposed at the right end of the cylinder head 4.

  Before the engine 2 is warmed up (FIGS. 2A and 2B), cooling water is circulated only in the first flow path 11 connecting the head side discharge hole 62 and the introduction hole 36, and the block side discharge is performed. Since the cooling water is not circulated through the third flow path 13 connecting the hole 37 and the introduction hole 36, the cooling water is discharged only from the head side discharge hole 62, and is not discharged from the block side discharge hole 37. After the engine 2 is warmed up (FIGS. 2 (c) and 2 (d)), the cooling water is also circulated through the third flow path 13, so that the cooling water is also discharged from the block-side discharge hole 37 ( Arrows R10, R2).

  In such a situation, the spacer 40 is accommodated in the block-side water jacket 33, the peripheral wall 41 of the spacer 40 faces the cylinder bore wall 32a in close proximity, and the cooling water is mainly a peripheral wall in the block-side water jacket 33. 41, and does not flow directly on the surface of the cylinder bore wall 32a, local cooling of the cylinder bore wall 32a is suppressed, and a temperature difference between the first to fourth cylinders # 1 to # 4 is suppressed. .

<Ii>
As shown in FIGS. 3 and 4, the cooling water introduced from the introduction hole 36 into the block-side water jacket 33 by the water pump 5 is the first cylinder # 1 side of the cylinder row of the cylinder bore wall 32a of the first cylinder # 1. (Arrow R3). At this time, the spacer 40 is accommodated in the water jacket 33, and the peripheral wall 41 of the spacer 40 faces the cylinder bore wall 32a in close proximity, so that the cooling water hits the peripheral wall 41 of the spacer 40 and the first cylinder # 1. It does not directly hit the cylinder bore wall 32a. As a result, the cylinder bore wall 32a of the first cylinder # 1 is suppressed from being locally cooled to a low temperature.

<Iii>
As shown in FIG. 4, when the cooling water introduced from the introduction hole 36 hits the cylinder bore wall 32a of the first cylinder # 1 by the downstream portion 36a of the introduction hole 36, it is at a relatively shallow angle in plan view from the intake side. Hit (arrow R3). Therefore, the amount of cooling water flowing through the intake side flow path 33i of the water jacket 33 is relatively small (arrow R4), and the amount of cooling water flowing through the exhaust side flow path 33e is relatively large (arrow R5). Therefore, the cylinder block 3 on the exhaust side whose temperature is likely to rise more than that on the intake side is further cooled, so that the temperature difference between the intake side and the exhaust side of each cylinder is suppressed.

<Iv>
The cooling water introduced from the introduction hole 36 is directed upward, that is, toward the head side water jacket 61 by the inclined guide portion 47 (arrow R6) while flowing into the exhaust side flow path 33e. As described with reference to FIG. 2, since the cooling water always circulates in the first flow path 11 connecting the head side discharge hole 62 and the introduction hole 36, the cooling water directed to the head side water jacket 61 side. Passes through the first communication hole 52 and flows into the head-side water jacket 61 (arrow R7).

  In particular, before the engine 2 is warmed up (FIGS. 2A and 2B), the cooling water does not circulate in the third flow path 13 connecting the block-side discharge hole 37 and the introduction hole 36. The cooling water directed toward the side water jacket 61 attempts to flow into the head side water jacket 61 through the first communication hole 52 (arrow R7). Therefore, before the engine 2 is warmed up, the cylinder block 3 is not cooled and the temperature gradually rises to promote warming up of the engine 2.

<V>
As described in <iv>, before the engine 2 is warmed up (FIGS. 2A and 2B), the third flow path 13 that connects the block-side discharge hole 37 and the introduction hole 36 is Since the cooling water does not circulate, the cooling water (arrow R8) that has flowed into the exhaust-side flow path 33e of the block-side water jacket 33 is directed upward when it comes near the second communication holes 53a to 53d on the exhaust side. A part of the gas passes through the second communication holes 53a to 53d and flows into the head-side water jacket 61 (arrows R11 to R14). That is, in the exhaust-side flow path 33e, there is a vertical flow in the vicinity of the communication hole from the block-side water jacket 33 toward the head-side water jacket 61 in the vicinity of the second communication holes 53a to 53d.

  And as above-mentioned, since the distribution promotion part 46 which has a distribution promotion function is provided with respect to the 2nd communicating holes 53b-53d (except 53a), the cooling water which flows through the inside of the exhaust side flow path 33e The first flange 42 and the second flange 43 do not impede the passage of a part of the air through the second communication holes 53b to 53d (excluding 53a) and flowing into the head-side water jacket 61. The flow of the coolant to the second communication holes 53b to 53d (excluding 53a) outside the peripheral wall 41 in the side flow path 33e is promoted.

  Thereby, in the second to fourth cylinders # 2 to # 4, the vertical flow in the vicinity of the communication hole is strengthened outside the peripheral wall 41 by the flow promoting function of the flow promoting portion 46 (see the thick arrow in FIG. 5). In exchange for this, it is weakened inside the peripheral wall 41, that is, between the peripheral wall 41 and the cylinder bore wall 32a (see thin arrows in FIG. 5). As a result, the flow promoting function of the flow promoting portion 46 almost stops the flow inside the peripheral wall 41, so that the cooling water flowing outside the peripheral wall 41 may wrap around from the lower side between the peripheral wall 41 and the cylinder bore wall 32a. Effectively suppressed. Therefore, the cooling water is prevented from flowing directly on the surface of the cylinder bore wall 32a, the heat is deprived from the cylinder bore wall 32a, and the warm-up of the engine 2 is promoted.

  The reason why the flow promoting portion 46 is not provided in the first cylinder # 1, that is, the second communication hole 53a is as follows. The first cylinder # 1 is located upstream of the second to fourth cylinders # 2 to # 4 in the flow direction of the cooling water (arrow R8) and the flow of the cooling water is relatively strong. The vertical flow (arrow R11) in the vicinity of the communication hole generated on the exhaust side of the first cylinder # 1 by hitting the outer wall portion 35e of the exhaust side flow path 33e is the exhaust side of the second to fourth cylinders # 2 to # 4. Compared with the vertical flow (arrows R12 to R14) in the vicinity of the communication hole generated in the above, it is originally strong outside the peripheral wall 41. Therefore, since the flow inside the peripheral wall 41 almost stops without providing the flow promoting part 46 for the second communication hole 53a, it is not necessary to provide the flow promoting part 46.

<Vi>
Similar to that described in <v>, the cooling water (arrow R4) that has flowed into the intake-side flow path 33i of the block-side water jacket 33, and the cooling that has made a U-turn from the exhaust-side flow path 33e to the intake-side flow path 33i. Water (arrow R9) is also directed upward when it comes close to the intake side second communication holes 53e and 53f, and a part of the water passes through the second communication holes 53e and 53f and passes through the head side water jacket. 61 (arrows R15 and R16). That is, also in the intake side flow path 33i, in the vicinity of the second communication holes 53e and 53f, there is a vertical flow in the vicinity of the communication hole from the block side water jacket 33 toward the head side water jacket 61.

  Since the second communication holes 53e and 53f are provided with the flow promoting part 46 having the flow promoting function as described above, a part of the cooling water flowing in the intake side flow path 33i is the first. The first flange 42 and the second flange 43 do not hinder the passage through the two communication holes 53e and 53f and into the head-side water jacket 61. Therefore, the outside of the peripheral wall 41 in the intake-side flow path 33i. The flow of the cooling water in the second communication holes 53e and 53f is promoted.

  As a result, in the second cylinder # 2 and the third cylinder # 3, the vertical flow in the vicinity of the communication hole is strengthened outside the peripheral wall 41 by the flow promoting function of the flow promoting portion 46 (thick arrow in FIG. 5). In exchange for this, it is weakened inside the peripheral wall 41, that is, between the peripheral wall 41 and the cylinder bore wall 32a (see thin arrows in FIG. 5). As a result, the flow promoting function of the flow promoting portion 46 almost stops the flow inside the peripheral wall 41, so that the cooling water flowing outside the peripheral wall 41 may wrap around from the lower side between the peripheral wall 41 and the cylinder bore wall 32a. Effectively suppressed. Therefore, the cooling water is prevented from flowing directly on the surface of the cylinder bore wall 32a, the heat is deprived from the cylinder bore wall 32a, and the warm-up of the engine 2 is promoted.

<Vii>
On the exhaust side of the spacer 40, the vertical walls 44a and 44b are respectively provided on the first flange on the downstream side of the flow direction (arrow R8) of the cooling water from the flow promoting portions 46 of the second cylinder # 2 and the third cylinder # 3. 42 and the second flange 43 are continuously provided on the outer surface of the peripheral wall 41. Therefore, the cooling water that has flowed through the exhaust-side flow path 33e of the block-side water jacket 33 hits the vertical walls 44a and 44b, and part of the cooling water flows toward the second communication holes 53b and 53c (arrows R12 and R13). Converted. Thereby, the distribution promotion function of the distribution promotion unit 46 is strengthened.

  The reason why the vertical wall is not provided in the fourth cylinder # 4, that is, the second communication hole 53d is as follows. The fourth cylinder # 4 is located at the right end of the block-side water jacket 33, where the width of the water jacket 33 is narrow as shown in FIG. , Brake on the flow of cooling water. Therefore, with respect to the second communication hole 53d, a part of the cooling water is converted into a flow (arrow R14) toward the second communication hole 53d without providing the vertical wall as described above. It is not necessary to provide a vertical wall.

  Since the cooling water flows from the left and right sides of the cylinder row and collides with each other on the intake side (arrows R4 and R9), a part of the cooling water is provided in the second communication holes 53e and 53e without providing the vertical wall as described above. It is converted into a flow (arrows R15, R16) toward 53f. Therefore, the vertical wall as described above is not provided on the intake side of the spacer 40.

  Further, as described above, since the cooling water flows from the left and right sides of the cylinder row on the intake side, the flow promoting portion 46 on the intake side has the first flange 42 and the second flange on the left and right sides of the second communication holes 53e and 53f. Notches 46d and 46e of the flange 43 are formed. On the other hand, since the cooling water flows only from the left side of the cylinder row on the exhaust side, the flow promoting part 46 on the exhaust side has the first flange 42 and the second flange only on the left side of the second communication holes 53b to 53d. 43 notches 46a to 46c are formed.

<Viii>
Except for the portion where the first communication hole 52 and the inclined guide portion 47 are located at the upper end portion of the peripheral wall 41 and the portion where the second communication holes 53b to 53f and the flow promoting portion 46 are located, outward of the spacer 40. An extending first flange 42 is provided. Therefore, the first flange 42 prevents the cooling water flowing outside the peripheral wall 41 in the block-side water jacket 33 from flowing from above between the peripheral wall 41 and the cylinder bore wall 32a.

  In other words, the flow promotion function of the flow promotion portion 46 described above suppresses the sneaking from the lower side to the cylinder bore wall 32a side of the cooling water, whereas the first flange 42 suppresses the sneaking from the upper side. Is done.

(4) Operation As described above, the engine cooling device 1 according to the present embodiment includes the block-side water jacket 33 provided in the cylinder block 3 so as to surround the cylinder bore wall 32a of the engine 2, and the cylinder block. 3 and a head side water jacket 61 provided on the cylinder head 4 coupled to the cylinder head 4.

  The cooling device 1 is accommodated in the block-side water jacket 33 and is provided at the upper end of the peripheral wall 41 with a spacer 40 having a peripheral wall 41 that is close to and opposed to the cylinder bore wall 32a. A first flange 42 extending outward, and a gasket 50 interposed between the cylinder block 3 and the cylinder head 4, the block-side water jacket 33 and the head-side water jacket 61 are mutually connected. Second communication holes 53a to 53f communicating with each other, an introduction hole 36 provided in the cylinder block 3 for introducing cooling water into the block-side water jacket 33, provided in the cylinder head 4, and the head-side water jacket. Head side discharge hole 62 through which cooling water is discharged from 61, and the first flange A flow promoting portion 46 for promoting the flow of cooling water to the second communication holes 53b to 53f (excluding 53a) outside the peripheral wall 41 of the spacer 40 in the block-side water jacket 33; ,have.

  According to this configuration, the peripheral wall 41 of the spacer 40 accommodated in the block-side water jacket 33 faces the cylinder bore wall 32a in close proximity, and the first flange that extends outward of the spacer 40 at the upper end portion of the peripheral wall 41 is provided. Since the first flange 42 is provided, the cooling water flowing outside the spacer 40 from the peripheral wall 41 in the block-side water jacket 33 circulates from above between the peripheral wall 41 and the cylinder bore wall 32a. Is suppressed.

  On the other hand, the flow promoting function of the flow promoting portion 46 strengthens the vertical flow in the vicinity of the communication hole on the outside of the peripheral wall 41, and accordingly, the flow of cooling water almost stops inside the peripheral wall 41. It is effectively suppressed that the cooling water flowing outside the wall flows from the lower side between the peripheral wall 41 and the cylinder bore wall 32a.

  As described above, since the wraparound of the cooling water toward the cylinder bore wall 32a is suppressed at both the upper end and the lower end of the peripheral wall 41, the cooling water is interposed between the spacer 40 accommodated in the block-side water jacket 33 and the cylinder bore wall 32a. An engine cooling device 1 that can sufficiently suppress the sneaking around is provided. Therefore, the engine 2 can be warmed up early by suppressing the overcooling of the cylinder bore wall 32a when the engine 2 is cold.

  In addition, the second communication holes 53a to 53f that allow the block-side water jacket 33 and the head-side water jacket 61 to communicate with each other using the gasket 50 interposed between the cylinder block 3 and the cylinder head 4 are good. Can be provided.

  In the present embodiment, the vertical wall extends from the outer surface of the peripheral wall 41 to the downstream side in the flow direction of the cooling water flowing in the circumferential direction on the outer side of the peripheral wall 41 with respect to the flow promoting portion 46. 44a and 44b are erected.

  According to this configuration, the cooling water flowing in the block-side water jacket 33 hits the vertical walls 44a and 44b, and a part thereof is converted into a flow toward the second communication holes 53b and 53c. The distribution promotion function of the promotion unit 46 is strengthened.

  In the present embodiment, the engine 2 is a four-cylinder engine, and coolant that flows in the circumferential direction outside the peripheral wall 41 with respect to the boundary portions of the cylinder bores 32 of the first to fourth cylinders # 1 to # 4 adjacent to each other. Barriers 45 a to 45 f are erected from the outer surface of the peripheral wall 41 continuously to the first flange 42 on the upstream side in the flow direction.

  According to this configuration, the cooling water flowing in the block-side water jacket 33 hits the barriers 45a to 45f, and the momentum of the flow is weakened. Therefore, the boundary portion of the cylinder bore 32 on the downstream side of the barriers 45a to 45f The momentum that the cooling water hits is also weakened. Therefore, when the cooling water hits the boundary portion of the cylinder bore 32, the momentum of the cooling water toward the cylinder head 4 becomes weak, so that the cooling water goes over the first flange 42 to the cylinder bore wall 32a side. Is further suppressed.

  In the present embodiment, a second flange 43 extending outward of the spacer 40 is provided below the first flange 42 of the peripheral wall 41.

  According to this configuration, since the first flange 42 and the second flange 43 are provided in two stages, it is further possible for the cooling water to go over the flanges 42 and 43 toward the cylinder bore wall 32a. It is suppressed.

  In the present embodiment, the engine 2 is a four-cylinder engine, and the flow promoting part 46 is arranged in the flow direction of the cooling water flowing in the circumferential direction outside the peripheral wall 41 of the four cylinder bores 32 in the exhaust side flow path 33e. Provided for the cylinder bores 32 of the second to fourth cylinders # 2 to # 4 on the downstream side.

  The reason for this is that, as described in <v> of [3-4], the flow of the cooling water in the block-side water jacket 33 is strong on the upstream side near the cooling water introduction hole 36, and the cooling water introduction hole. Weak on the downstream side far from 36. Therefore, the vertical flow (arrows R11 to R14) in the vicinity of the communication hole is strong in the cylinder bore 32 of the first cylinder # 1 on the upstream side and in the cylinder bore 32 of the second to fourth cylinders # 2 to # 4 on the downstream side. weak. Therefore, according to this configuration, the flow promoting function of the flow promoting portion 46 is provided to the cylinder bores 32 of the downstream second to fourth cylinders # 2 to # 4 where the longitudinal flow in the vicinity of the communication hole is relatively weak. Therefore, the cooling water wraps around the cylinder bore wall 32a of the downstream second to fourth cylinders # 2 to # 4 that need further measures to suppress overcooling of the cylinder bore wall 32a. Is satisfactorily suppressed.

  In the present embodiment, the cooling device 1 has a block-side discharge hole 37 provided in the cylinder block 3 for discharging cooling water from the block-side water jacket 33 in addition to the head-side discharge hole 62. ing.

In the cooling device 1, the cooling water introduced into the block-side water jacket 33 from the introduction hole 36 flows into the head-side water jacket 61 through the communication holes 52, 53 a to 53 f, and the head-side water jacket. A first path (that is, a cold path K1 shown in FIG. 2A and a pre-warm-up path K2 shown in FIG. 2B) that flows through the head 61 and is discharged from the head-side discharge hole 62; Cooling water introduced into the block-side water jacket 33 from the introduction hole 36 flows into the head-side water jacket 61 through the communication holes 52, 53a to 53f, flows through the head-side water jacket 61, and is discharged to the head side. In addition to being discharged from the hole 62, the second path (flow through the block-side discharge hole 37 through the block-side water jacket 33) Wachi Figure 2 and the warm-up completion path K4 shown in warm-up after the route K3 and FIG 2 (d) shown in (c)) is provided.

  The cooling device 1 switches the cooling water flow path to the first path when the head combustion chamber wall surface temperature is lower than the second determination temperature, and the head combustion chamber wall surface temperature is equal to or higher than the second determination temperature. Includes an ECU 100 that switches the flow path of the cooling water to the second path.

  According to this configuration, when the head combustion chamber wall surface temperature is cold below the second determination temperature, only the cylinder head 4 is cooled by the first path through which the coolant flows through the head-side water jacket 61, and the head combustion After the warming-up of the wall surface temperature equal to or higher than the second determination temperature, the cylinder block 3 is cooled in addition to the cylinder head 4 by the second path through which the coolant flows through the block-side water jacket 33 and the head-side water jacket 61. Is done. Therefore, when the engine 2 is cold, the flow promoting function of the flow promoting portion 46 prevents the cooling water from entering the cylinder bore wall 32a, thereby suppressing the overcooling of the cylinder bore wall 32a. The overcooling of the cylinder bore wall 32a is also suppressed by switching the flow path of the cooling water to the first path. As a result, the engine 2 can be warmed up more quickly.

  In the above embodiment, the engine 2 is an in-line four-cylinder diesel engine, but the number of cylinders is other than four as long as the engine coolant is a type in which the engine coolant flows in the water jacket provided in the cylinder block. But it can also be a gasoline engine.

DESCRIPTION OF SYMBOLS 1 Cooling device 2 Engine 3 Cylinder block 4 Cylinder head 32a Cylinder bore wall 33 Block side water jacket (1st water jacket)
36 Introduction hole (Introduction part)
36a Downstream part of introduction hole 37 Block side discharge hole (discharge part)
40 Water jacket spacer (spacer member)
41 Perimeter wall 42 1st flange (flange)
43 Second flange (second flange)
44a, 44b Vertical wall 45a-45f Barrier 46 Distribution promotion part 46a-46e Notch 47 Inclined guide part 47a Slope flange 50 Gasket 52 First communication hole 53a-53f Second communication hole 61 Head side water jacket (second water jacket Jacket)
62 Head side discharge hole (discharge section)
100 ECU
K1 Cold path (first path)
K2 Warm-up route (first route)
K3 Path after warm-up (second path)
K4 Path after warm-up completion (second path)

Claims (6)

A multi-cylinder having a first water jacket provided on a cylinder block so as to surround cylinder bore walls of a plurality of cylinders of an engine, and a second water jacket provided on a cylinder head coupled to an upper surface of the cylinder block An engine cooling device,
A spacer member housed in the first water jacket and having a peripheral wall facing and facing the cylinder bore wall;
A flange portion provided at an upper portion of the peripheral wall and extending outward in the cylinder bore radial direction from the peripheral wall;
A communication hole provided in a gasket interposed between the cylinder block and the cylinder head, and communicating the first water jacket and the second water jacket with each other;
An introduction portion provided in the cylinder block, into which cooling water is introduced into the first water jacket from a position below the flange portion;
A discharge portion that is provided in the cylinder head and from which the cooling water is discharged from the second water jacket;
By the height of the upper end of the spacer member is a spacer member in the lower position than the upper end of the first water jacket is disposed, predetermined between the upper end and the lower surface of the gasket of the spacer member A gap is formed ,
In the first water jacket, a plurality of notches are provided in the flange portion as a flow promoting portion for promoting the flow of cooling water outside the peripheral wall of the spacer member to the communication hole. The flange portion is formed so as to extend the region excluding the notch in the cylinder row direction,
The cooling device for an engine, wherein the communication hole is provided at a position overlapping the notches when viewed in the vertical direction . The engine cooling device according to claim 1,
A vertical wall is erected from the outer surface of the peripheral wall continuously to the flange portion on the downstream side in the flow direction of the cooling water flowing in the circumferential direction outside the peripheral wall with respect to the flow promoting portion. Engine cooling system. The engine cooling device according to claim 1 or 2,
A barrier is erected from the outer surface of the peripheral wall continuously to the flange portion on the upstream side in the flow direction of the cooling water flowing in the circumferential direction outside the peripheral wall with respect to the boundary portion of each cylinder bore of the cylinders adjacent to each other. A cooling system for an engine. The engine cooling device according to any one of claims 1 to 3,
A cooling device for an engine, wherein a second flange portion extending outward in the cylinder bore radial direction from the peripheral wall is provided below the flange portion of the peripheral wall. The engine cooling device according to any one of claims 1 to 4, wherein:
The above-mentioned distribution promotion part is provided with respect to the cylinder bore of the downstream of the flow direction of the cooling water which flows the outside of a peripheral wall in the peripheral direction among a plurality of cylinder bores, The engine cooling device characterized by things. The engine cooling device according to any one of claims 1 to 5,
A discharge part provided in the cylinder block and from which the cooling water is discharged from the first water jacket;
The cooling water introduced into the first water jacket from the introduction part flows into the second water jacket through the communication hole, flows through the second water jacket, and is discharged from the discharge part of the cylinder head. A first path;
The cooling water introduced into the first water jacket from the introduction part flows into the second water jacket through the communication hole, flows through the second water jacket, and is discharged from the discharge part of the cylinder head. And a second path through the first water jacket and discharged from the discharge part of the cylinder block,
When the engine temperature is lower than the predetermined warm-up determination temperature, the coolant flow path is switched to the first path, and when the engine temperature is equal to or higher than the warm-up determination temperature, the second path is switched. An engine cooling system characterized by that.

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