JP2005194884A - Engine cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine cooling device capable of dividing the flow of cooling water from a water pump to a cylinder block and a cylinder head by a simple structure. <P>SOLUTION: This engine cooling device dividing the flow of the cooling water from the water pump 13 installed at the end part of the cylinder block 2 to a cylinder block 2 and the cylinder head 3 comprises an extension passage 35 (main passage) in which the cooling water discharged from the water pump 13 flows to lead the cooling water from the cylinder block 2 to the cylinder head 3, a water jacket 16 formed along the outer layers of the plurality of cylinders formed in the cylinder block, a left side outer wall part (partition wall) 17b partitioning the main passage from the water jacket, and an opening (branched part) formed by cutting out the partition wall from the upper surface of the cylinder block and leading a part of the cooling water flowing in the main passage to the water jacket 16. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cooling device used in a water-cooled engine, and more particularly to an engine cooling device that cools an engine by circulating cooling water from a water pump through both water jackets of a cylinder head and a cylinder block.

  The cooling system for a water-cooled engine is a cooling system after the cooling water discharged from the water pump flows into the cooling water inlet of the water jacket, which is a cooling water passage disposed in the engine body, and circulates through each part of the water jacket. While the water temperature is low, open the short circuit, return the cooling water from the short circuit directly to the inlet of the water pump to promote warm-up, and when the cooling water temperature rises, open the main circuit with the radiator installed, A cooling water circulation system is provided in which cooling water is supplied to the main circulation path for cooling, and the cooled cooling water is returned to the suction port of the water pump.

  Here, the cylinder block and the cylinder head constituting the engine main body have different cooling characteristics required after completion of warm-up. In other words, the cylinder head has a low wall facing the cylinder block where the cylinder facing position tends to increase in temperature, ensuring the heat resistance of the same part, and suppressing the increase in intake port temperature to suppress the reduction in intake efficiency. It is also desirable to cool sufficiently. On the other hand, the cylinder block needs to optimize the friction between the cylinders housed in the cylinder block and the piston that reciprocates in the cylinder block. Must be maintained at an appropriate temperature, and it is necessary to eliminate excessively low temperatures and excessively high temperatures and to ensure an appropriate temperature.

  By the way, when circulating cooling water through both the water jacket of the cylinder block and cylinder head that make up the engine body, due to the target cooling water temperature, the difference in auxiliary equipment such as water pump, thermostat, radiator, etc. of the cooling water circulation system The structure of the actual cooling water circulation system is different, and various circulation methods have been proposed.

  That is, in the cooling system of the basic circulation type engine in which the cooling water after passing through the water jacket in the cylinder block flows into the water jacket in the cylinder head and returns the cooling water to the water pump, the flow of the cooling water is roughly the flow of the engine body. Although the flow is smoother from below to above, the cooling efficiency of the cylinder head is relatively low.

  On the contrary, the cooling system for the engine of the cylinder head advance cooling system in which the water pump cooling water flows into the water jacket in the cylinder head, the cooling water after passing through the water jacket flows into the water jacket in the cylinder block, and the cooling water is returned to the water pump. However, the cooling efficiency of the cylinder head is relatively high, but the temperature of the cooling water flowing into the cylinder block after passing through the cylinder head fluctuates depending on the operating range, so the control to maintain the cylinder block at an appropriate temperature becomes unstable. .

Alternatively, in the cooling device for the cooling water branch circulation type engine that branches the cooling water discharge path of the water pump, flows the branching flow to the cylinder block and the cylinder head, and then merges them, and returns the cooling water to the water pump, The cylinder head and cylinder block can be cooled and held at an appropriate temperature.
Note that a cooling device that causes cooling water to flow through the cylinder head and the cylinder block is disclosed in Japanese Patent Laid-Open No. 2003-172140 (Patent Document 1).

Japanese Patent Application Laid-Open No. 2003-172140.

By the way, in the cooling system of the cooling water branch circulation type engine, the cylinder head and the cylinder block can be cooled and held at an appropriate temperature. However, the cooling water discharged from the water pump is supplied to the cylinder head side and the cylinder block side on the cooling water circulation system. It is necessary to provide a branching means for adjusting the amount of branching, and it is likely to cause problems such as mounting properties due to securing a mounting space for the branching means, complexity of the branching means, and cost increase. Yes.
The present invention has been made on the basis of the above-described problems, and an object of the present invention is to provide an engine capable of diverting the coolant immediately after being discharged from the water pump to the cylinder head side and the cylinder block side with a simple structure. It is to provide a cooling device.

  According to a first aspect of the present invention, there is provided a cooling device for an engine, wherein the cooling water from a water pump provided at an end of a cylinder block is diverted to the cylinder book and the cylinder head, and is discharged from the water pump. Main passage through which the cooled water flows and guides the cooling water from the cylinder block to the cylinder head, a water jacket formed along outer layers of a plurality of cylinders formed in the cylinder block, the main passage, and the above A partition wall that partitions the water jacket, and the partition wall is notched from the upper surface of the cylinder block and includes a branch portion that guides a part of the cooling water flowing in the main passage to the water jacket side. It is characterized by.

  The engine cooling device according to a second aspect of the present invention is the engine cooling device according to the first aspect, wherein a head bolt formed on an upper portion of the cylinder block for fixing the siricid head to the cylinder block can be inserted. The main passage is formed in the vicinity of the bolt hole located at the foremost end where the chain case of the cylinder block is provided.

  The engine cooling device according to claim 3 of the present invention is the engine cooling device according to claim 2, wherein the main passage has at least an arcuate outer wall forming the bolt hole, and an outer wall extending in the longitudinal direction of the cylinder block. And the partition wall.

  According to the first aspect of the present invention, the flow rate ratio of the cooling water between the head-side water jacket and the block-side water jacket can be adjusted in a simple configuration, and the cooling water of the appropriate flow rate is supplied to the cylinder block and the cylinder head, respectively. Can be cooled properly.

  According to the second and third aspects of the present invention, the main passage can be formed close to the inside of the cylinder block, and the increase in size of the engine can be suppressed.

  1 and 2 show an engine cooling apparatus as one embodiment of the present invention. This cooling device is mounted on a four-cycle gasoline engine for vehicles (hereinafter simply referred to as engine 1), and the engine is cooled with cooling water circulating along a cooling water circulation system R equipped inside and outside the engine.

  The cylinder head 3 is provided on the upper surface of the cylinder block 2, and head bolts (not shown) are inserted into a plurality of head bolt holes A (see FIG. 7) penetrating from the upper surface of the cylinder head 2 to the cylinder block 3 and fastened. The engine 1 has a head cover 11 on the upper side of the cylinder head 3 and an oil pan 4 on the lower side of the cylinder block 2 and the cylinder head 3, and a chain case 5 on one side thereof. Form the body. A plurality of cylinders S are provided in the cylinder block 2 and the cylinder head 3, and each component of an intake / exhaust system and a valve system (not shown) that controls intake and exhaust gases that are sucked into and exhausted from a combustion chamber inside the cylinder S 2. And a crankshaft 6 that rotates in response to output energy received by a piston (not shown) in the combustion chamber. FIG. 2 shows only the intake manifold 7 and the exhaust manifold 8 of the intake / exhaust system.

  A radiator 9, a thermostat 12, and a water pump 13, which are auxiliary equipment for the cooling device, are disposed on the outer wall of the engine body and the vicinity thereof. Here, the radiator is connected to a cylinder head rear nipple (outflow pipe) 26 and an upper pipe 14, and is connected to a lower pipe 15 and a fitting (lid joint) portion provided on a thermostat 12 on the cylinder block front side. . The thermostat 12 is mounted on the left side surface of the cylinder block 2, and the water pump 13 is mounted on the front side of the chain case 5.

  The cylinder block 2 is provided with a plurality of vertical (vertical Z) cylinders S at predetermined intervals in the longitudinal direction X of the engine, and continuously covers the periphery of the cylinders S with a block-side water jacket 16 and further on the outside. Are continuously covered by front and rear, left and right vertical outer walls 17, and the upper and lower ends of four cylinders S and front, rear, left and right vertical outer walls 17 are connected by overlapping wall portions 18 and connecting walls 19, thereby blocking the block side. The water jacket 16 is formed in a closed space. The cylinder block 2 is formed with a skirt portion 171 extending further downward from the coupling wall 19, and a lower chamber is closed by an oil pan 4 to form a crank chamber.

Here, one front side of the cylinder block 2 (the lower wall in FIG. 3) is formed as an end inner wall 17f, and an extending portion 17g projects from the left and right ends of the end inner wall 17f. The flange portion overlaps the connection flange 501 on the chain case 5 side, and is fastened with bolts (not shown).
The water pump 13 and the thermostat 12 of the cooling water circulation system R are arranged close to each other on the inner wall 17f of the end portion and the rear side of the cylinder block 2 (front side in FIGS. 1 and 4 and left side in FIG. 2). The

  As shown in FIGS. 2, 3, and 4, the thermostat 12 is formed by projecting a cylindrical base portion 21 of the thermostat 12 from the left outer wall portion 17b, and is tightly integrated integrally with the annular distal end portion of the cylindrical base portion 21. 22 are joined to form an outer shell, and first and second inflow chambers 23 and 24 are formed in the outer shell. In addition, the first and second inflow chambers 23 and 24 are alternately opened and closed, and the valve bodies 30 are integrally connected to each other with the temperature sensing unit 10 interposed therebetween. The temperature sensing unit 10 senses the cooling water temperature and selectively guides the cooling water to the inflow chamber 23 to control the temperature of the cooling water flowing into the engine.

As shown in FIGS. 1 and 2, the first inflow chamber 23 is connected to the cylinder head 3 through an outflow pipe 26, which will be described later, through a heater 50 and a short circuit 27. Similarly, the second inflow chamber 24 is connected to the protruding end of the outflow pipe 26 via a cooling path 28 including the upper pipe 14, the radiator 9, and the lower pipe 15.
As shown in FIGS. 3 and 4, the inflow chambers 23, 24 communicate with a suction passage 32 that passes through a protruding wall portion 29 protruding from the cylindrical base portion 21 and the left outer wall portion 17 b and communicates with a pump chamber 131 described later.

  As shown in FIGS. 3 and 4, the protruding wall portion 29 has a base end side that overlaps the left outer wall portion 17b and the one extending portion 17g and protrudes in the cylinder lateral width direction Y. In particular, one side (downward in FIG. 3) The opposing one-side facing surface F forms a surface that is continuous with the left and right extending portions 17g, and the case-joining surface fc of the chain case 5 is formed so as to be able to come into close contact with the one-side facing surface F.

  The chain case 5 has a front wall 501 and left and right side walls 502 that are substantially continuous vertically, has a concave cross-section in plan view, and is formed so that the chain housing chamber 33 can be secured in the center when joined to the one side facing surface F. Is done. In addition, a thick bulging portion 34 is integrally formed continuously at a portion facing the protruding wall portion 29, and the water pump 13 is disposed at this portion.

  The water pump 13 is installed on the front side of the case of the wall thickness bulging portion 34, and is connected to a pump chamber 131 communicating with the suction passage 32, an impeller (not shown) accommodated in the chamber 131, and a rotation shaft of the impeller. The pump drive side connection part 133 fixed to the outer wall side of the bulging part 34, and the case side discharge path 132 extended from the upper end side of the pump chamber 131 are provided. The tip of the case side discharge path 132 protrudes and is formed so as to communicate with the extension path 35 formed on the wall portion 29 side.

  As shown in FIGS. 3 and 4, the extension path (main passage) 35 protrudes and is formed with a lateral portion 351 formed inside the base end portion of the wall portion 29, and subsequently the thickness of the left outer wall portion (partition wall) 17 b A vertical portion 352 formed separately from the block-side water jacket 16 is provided in the portion. The vertically oriented portion 352 is provided in the vicinity of the bolt hole A on the foremost end side where the chain case 5 of the cylinder block 2 is mounted, and the outer wall of the bolt hole A and the outer wall 17 extending in the longitudinal direction of the cylinder block 2 and the rear The wall portion 17b is surrounded.

  The upper end of the vertically oriented portion 352 communicates with a cut portion h that is recessed in the upper wall of the left outer wall portion 17b. The cut portion h forms a flow path by overlapping with the overlapping wall portion (low wall) 37 of the cylinder head 3. Among these, a portion facing the vertically oriented portion 352 communicates with the head-side water jacket 36 through a through hole 40 formed in the overlapping wall portion 37 to form a first branch path r1. Further, the portion of the digging portion h that reaches the block-side water jacket 16 from the portion facing the vertical portion 352 overlaps with the overlapping wall portion 37 so that the second branch passage r2 that branches off from the first branch passage r1 extends. It is formed and communicates with the block-side water jacket 16 through the opening (branch portion) m.

  In this manner, the overlapping wall portion 37 (low wall) on the cylinder head side overlaps the overlapping wall portion 18 of the left outer wall portion 17b, so that the cooling water flows upward into the thick portion of the left outer wall portion 17b. A (main passage) 35 and a first branch passage r1 branched from the tip of the main passage 35 and communicating with the head-side water jacket 36 and a second branch passage r2 communicating with the block-side water jacket 16 are formed to extend.

  As shown in FIGS. 5 and 6, the opening m formed by the overlap of the left outer wall portion 17 b and the overlapping wall portion 37 is a vertical width that is a width that is opposite to the overlapping wall portion 37 and a lateral width L <b> 1 that approximates the vertically oriented portion 352. A width L2, and is formed in a substantially rectangular shape. In particular, as shown in FIG. 5, the lower edge portion m1 of the opening m is formed as a relatively thin plate-like lower edge portion, whereby an opposing gap L2 between the lower edge portion m1 and the overlapping wall portion 37 is formed. Increase and decrease can be adjusted relatively easily.

  In addition, the dividing part h where the overlapping wall part 37 overlaps, the opening m, the first second branch paths r1, r2, and the like branch into the block-side water jacket 16 and the head-side water jacket 36 from the discharge cooling water of the water pump 13. Is forming.

Here, the flow rate of the second branch path r2 can be regulated by the opening area (flow channel area) of the opening m, that is, the ratio of each cooling water inflow to the block-side water jacket 16 and the head-side water jacket 36 can be increased or decreased. .
For example, if the facing gap between the lower edge portion m1 of the opening m and the overlapping wall portion 37 is narrowed and formed as a vertical width L2 ′ as shown by a two-dot chain line, the cooling water flow rate to the block-side water jacket 16 is reduced. Will be allowed to. As a result, the flow rate of the cooling water to the head-side water jacket 36 can be increased, the cooling efficiency of the head-side water jacket 36 can be increased, and the cooling efficiency of the block-side water jacket 16 can be suppressed.

  The overlapping wall portion 37 of the cylinder head 3 is overlapped with the overlapping wall portion 18 (upper wall) via the gasket 38. An annular outer wall 39 extending vertically is continuously formed from the peripheral edge of the overlapping wall portion 37, and includes an intermediate wall 41 (see FIG. 4) that is irregularly and integrally joined to the inner wall portion of the outer wall 39. A head-side water jacket 36 is formed between the upper and lower sides of the intermediate wall 41 and the overlapping wall portion 37. The head-side water jacket 36 is formed so as not to interfere with a valve system and ignition system members (not shown). As shown in FIG. 7, the overlapping wall portion 37 of the cylinder head 3 is formed with a concave wall 371 at a portion facing each cylinder S, and the concave wall 371 has a port p1 of an air supply / exhaust valve (not shown) and a spark plug (not shown). A mounting hole p2 (not shown) is formed.

  The head-side water jacket 36 forms a cooling water passage continuous in the engine longitudinal direction X, and a through hole 40 (see FIGS. 1 and 7) is formed on one side end side of the overlapping wall portion 37. The through hole 40 communicates with the first branch path r <b> 1 during the polymerization with the polymerization wall portion 18, and introduces the cooling water discharged from the water pump 13 through the extension path 35. Further, in the vicinity of the other end side (right side in FIGS. 1 and 2) of the overlapping wall portion 37 of the cylinder head 3, there is an outlet 42 through which cooling water flows from the upper end opening side of the block side water jacket 16 to the head side water jacket 36. It is formed. As a result, the cooling water flowing in the block-side water jacket 16 in the engine longitudinal direction X is guided to the head-side water jacket 36, and the outflow pipe formed on the outer wall 39 on the other side (right side in FIGS. 1 and 2) of the cylinder head. 26 can flow out to the outside.

  As shown in FIGS. 1 and 2, the outflow pipe 26 provided on the other side of the cylinder head 3 (the right side in FIGS. 1 and 2) has an end communicating with the radiator 9 via the upper pipe 14. It communicates with the first inflow chamber 23 of the thermostat 12 through a pipe 27.

The operation of the engine cooling apparatus having such a configuration will be described.
The cooling water sucked from the suction path 32 by the water pump 13 is branched after passing through the case-side discharge path 132 and the extension path 35, and is blocked through the first branch path r1 to the head-side water jacket 36 and through the second branch path r2. It flows into the side water jacket 16.

  The cooling water flow n1 that reaches the head-side water jacket 36 and sequentially cools the intake / exhaust port of each cylinder and the vicinity of the contact surface of the ignition system goes to the outflow pipe 26. The cooling water flow n2 divided into the block-side water jacket 16 cools the outer peripheral area of each cylinder S and flows in the engine longitudinal direction X, cools the outer peripheral area of the other cylinder S, and then the head-side water from the outlet 42. It reaches the jacket 36 and goes to the outflow pipes 26, 51. The flow passage cross section of the outflow pipe 26 is set larger than the outflow pipe 51.

  At this time, when the cooling water temperature is relatively low, for example, when the thermostat 12 opens the heat pipe 27 and closes the cooling path 28, the cooling water from the outflow pipe 51 passes through the heater 50 to the water pump 13. Returned. When the coolant temperature is relatively high, for example, when the coolant is warmed up, the coolant from the outflow pipe 26 is radiated by the radiator 9 and returned to the water pump 13 by opening the cooling passage 28.

In such a cooling device, the flow rate ratio of the cooling water flow rate that flows through the head side water jacket 36 and the block side water jacket 16 is defined according to the size of the flow path area of the opening m.
For example, when this apparatus is a standard engine not equipped with a supercharger, the lower edge portion m1 of the opening m is formed to have a vertical width L2 ′ as shown by a two-dot chain line in FIG. In this case, it is possible to provide a cooling device that can suppress the cooling rate by relatively reducing the amount of cooling water in the cylinder block, prevent overcooling of the cylinder block, and increase the intake efficiency of intake air by promoting the cooling of the cylinder head.

On the other hand, when the present apparatus is a turbo engine equipped with a supercharger, the lower edge portion m1 of the opening m is formed with a vertical width L2, as indicated by a solid line in FIG. In this case, it is possible to provide a cooling device that can increase the cooling ratio by increasing the amount of cooling water in the cylinder block by increasing the flow path cross-sectional area (cross-sectional area) of the opening m, thereby preventing the cylinder block from becoming hot.
Thus, even when the characteristics of the engine 1 are different and the cooling characteristics are different, the cooling characteristics only increase or decrease the vertical width L2 of the lower edge portion m1 of the opening m, and the turbo engine can be used as a cooling device for a standard engine. As an engine cooling device, the cooling operation can be appropriately performed. For this reason, the cooling device of the present invention can be easily applied to a plurality of engines having different cooling characteristics with a simple configuration without causing an increase in cost.

Further, the structure of the branch portion including the opening m, the first and second branch paths r1, r2, and the like can be simplified, and can be mounted in the outer wall 17 of the cylinder block, so that it is possible to easily secure a space for mounting the branch portion configuration. . In addition, the flow rate ratio of the cooling water between the head side water jacket 36 and the block side water jacket 16 can be adjusted only by increasing / decreasing the area of the opening m, so that a simple configuration can be adopted and an increase in cost can be prevented.
Furthermore, since the opening m forms a part of the portion formed as the severing portion h in the rear outer wall 17b of the cylinder block 2, it can be changed by machining.
For this reason, the opposing gap L2 can be adjusted relatively easily, and the flow rate ratio of the cooling water between the head-side water jacket 36 and the block-side water jacket 16 can be adjusted easily, and the cylinder block 2 and the cylinder head 3 can be adjusted to an appropriate flow rate. Can be cooled with cooling water.

  In the above embodiment, in the engine cooling device of FIG. 1, the overlapping wall portion 37 overlaps the overlapping wall portion 18, so that the digging portion h forms the second branch path r <b> 2 and forms the opening m, Instead of this, the second branch path r2 that does not face the overlapping wall portion 37, that is, penetrates the overlapping wall portion 18 of the rear outer wall portion 17b, is branched from the first branch path r1 that communicates with the vertical portion 352. In this case as well, substantially the same effect as the engine cooling device of FIG. 1 can be obtained.

Further, although the lower edge portion m1 is formed substantially parallel to the upper side of the cylinder block, it may be formed to be inclined rightward or leftward. In this case, it is possible to change the flow rate of the cooling water that flows separately from the main passage and flows to the water jacket in the left and right directions.
Although the electric water pump 13 is used in the engine cooling apparatus in FIG. 1 as described above, a water pump that is driven by crank rotation may be used. In this case, the electric water pump 13 is almost the same as the engine cooling apparatus in FIG. Similar effects can be obtained.

  In the above description, the engine cooling device of the present invention is applied to a gasoline engine. However, the present invention can be similarly applied to a diesel engine.

1 is a schematic side view of an engine to which a cooling device for an engine according to an embodiment of the present invention is applied. It is a schematic plan view of the engine of FIG. It is a principal part notched top view of the cylinder block of the engine of FIG. It is a principal part expansion notched side view of the engine of FIG. FIG. 2 is an enlarged cutaway perspective view in the vicinity of an opening of a cylinder block of the engine of FIG. 1. FIG. 2 is an enlarged cutaway front view in the vicinity of an opening of a cylinder block of the engine of FIG. 1. It is a disassembled perspective view of the cylinder block and cylinder head of the engine of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder block 3 Cylinder head 13 Water hump 132 Discharge path 16 Block side water jacket 17 Outer wall 17b Left outer wall (partition wall) of engine
32 Water pump suction passage 35 Extension passage (main passage)
36 Head side water jacket 37 Overlapping wall part m Opening (branch part)
r1 First branch path r2 Second branch path R Cooling water circulation system X Engine longitudinal direction Y Engine lateral width direction

Claims (3)

In the engine cooling device for diverting the cooling water from the water pump provided at the end of the cylinder block to the cylinder book and the cylinder head,
A main passage through which the cooling water discharged from the water pump flows and guides the cooling water from the cylinder block to the cylinder head;
A water jacket formed along outer layers of a plurality of cylinders formed in the cylinder block;
A partition wall that partitions the main passage and the water jacket;
The engine cooling apparatus according to claim 1, wherein the partition wall is notched from the upper surface of the cylinder block, and includes a branch portion for guiding a part of the cooling water flowing in the main passage to the water jacket side. The engine cooling device according to claim 1,
A plurality of bolt holes formed in the upper part of the cylinder block, through which head bolts for fixing the silicon head to the cylinder block can be inserted;
The engine cooling device according to claim 1, wherein the main passage is formed in the vicinity of the bolt hole positioned at the foremost end where the chain case of the cylinder block is provided. The engine cooling device according to claim 2,
The engine cooling apparatus according to claim 1, wherein the main passage is formed of at least an arc-shaped outer wall forming the bolt hole, an outer wall extending in a longitudinal direction of the cylinder block, and the partition wall.

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