JP2007321755A - Flow passage forming member of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow passage forming member for reducing the number of part items, by reducing a space around an engine, in the flow passage forming member fastened to an engine body. <P>SOLUTION: This flow passage forming member 50 is formed with a cooling water flow passage 24 joined to a body side cooling water flow passage 22 with a cooling water joining opening 23, and an engine oil flow passage 34 joined to a body side engine oil flow passage 32 with an engine oil joining opening 33. A fastening boss hole 43 to a cylinder block 3 is arranged so that the center of gravity Pw of the cooling water joining opening 23 and the center of gravity Po of the engine oil joining opening 33, are positioned inside a square shape L formed by connecting the center of the respective fastening boss holes 43 by a straight line. The center of the respective fastening boss holes 43 is not positioned in an area R formed by connecting the outer edge of the cooling water joining opening 23 and the outer edge of the engine oil joining opening 33 by a tangent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flow path forming member fastened to an internal combustion engine body.

  For internal combustion engines such as automobiles (hereinafter referred to as engines), engine oil is pumped to each part to lubricate the valve operating mechanism and cool the pistons, so that it consists of oil pumps, oil filters, strainers, relief valves, etc. A system is provided. On the other hand, a cooling device is attached to the engine for cooling during operation. The cooling device is composed of a radiator, a water jacket provided on the cylinder head and the cylinder block, a hose connected from the radiator to the water jacket, a thermostat, and the like. By forcibly circulating cooling water in the water jacket, Absorbs the heat generated and keeps the engine at a constant temperature.

  It is desirable that the engine temperature be constant regardless of the outside air temperature. When the engine is cold, the engine temperature is raised to an appropriate temperature, and after reaching the appropriate temperature, cooling water is circulated to keep the temperature constant. By this, the inflow of cooling water to the radiator is controlled. In a thermostat case that houses such a thermostat and is connected to the engine and the cooling water flow path is opened, the external piping is reduced, and the space for use around the engine is reduced by downsizing, and the engine room is moved into the engine room. In order to facilitate the arrangement of the oil filter, a flange for connecting to the engine body, a flange for mounting the oil filter, and a flange for mounting the oil cooler are formed, and an oil flow communicating with the oil filter and the oil cooler is formed. A thermostat case in which paths are formed has been proposed (see Patent Document 1).

In addition, it is attached to the engine and formed inside to improve the assembly workability of the engine by improving the connection workability of flow path forming members such as hoses to multiple outlets, and to further reduce the number of parts. In the engine provided with the flow path forming member connected to the cooling water inflow port and the outflow port formed in the engine body, each of the plurality of flow paths has two outflow ports, which are connected to each other. An engine including a flow path forming member formed by partitioning two flow paths by a partition wall has been proposed. (See Patent Document 2)
JP-A-11-182223 JP 2002-339744 A

  However, in the conventional thermostat case, the flow path for cooling water and the flow path for engine oil are connected to the flow paths formed in the engine body by different flanges. There was a need to do. Further, since the engine oil flow path and the cooling water flow path are not arranged close to each other, the cooling effect of the engine oil cannot be sufficiently expected.

  Moreover, in the internal combustion engine provided with the flow path forming member described in Patent Document 2, the flow path forming member attached to the outside is integrally formed by reducing the number of parts by bringing the outflow flow path formed in the engine close to each other. However, although it is possible to improve the assembly of the engine, it is necessary to form two outflow passages in the engine partitioned by a partition wall or the like, and the manufacture of the engine body is complicated.

  The present invention has been made in view of such a background, and in the flow path forming member fastened to the engine body, the two flow paths are arranged close to each other and the two joint openings are joined to the engine body. An object of the present invention is to provide a flow path forming member that uses a common fastening member to save space around the engine and reduce the number of parts.

Moreover, in the flow path forming member fastened to the engine body, the number of parts is reduced by joining a flow path forming member having two flow paths to one flow path formed in the engine main body. Another object of the present invention is to provide a flow path forming member that facilitates manufacture of an engine body while improving engine assembly.

  In order to solve the above-mentioned problem, the invention according to claim 1 is formed in the internal combustion engine body, a first flow path that joins a first main body side flow path formed in the internal combustion engine body with a first joint opening. A flow path forming member that is fastened to the internal combustion engine main body by at least three fastening members, the second flow path forming member being joined to the second main body side flow path with a second joint opening. The center of gravity of the second joint opening and the center of gravity of the second joint opening are located inside the polygon having the largest area among the polygons formed by connecting the centers of the fastening members with straight lines.

  The invention according to claim 2 is the flow path forming member according to claim 1, wherein the center of each fastening member connects the outer edge of the first joint opening and the outer edge of the second joint opening by a tangent line. It is not located in the area | region formed by.

  The invention according to claim 3 is characterized in that, in the flow path forming member according to claim 1 or 2, the first joint opening and the second joint opening are formed on the same plane. To do.

  According to a fourth aspect of the present invention, in the flow path forming member according to any one of the first to third aspects, the first main body flow path and the first flow path are formed by being joined to the internal combustion engine main body. A first flow channel expansion chamber is formed between the first flow channel and the first flow channel.

  According to a fifth aspect of the present invention, in the flow path forming member according to any one of the first to third aspects, the second main body flow path and the first flow path forming member are joined to the internal combustion engine main body. A second channel expansion chamber is formed between the two channels.

  Moreover, the invention which concerns on Claim 6 is a flow-path formation member which concerns on any one of Claims 1-5. WHEREIN: The fluid which distribute | circulates a said 1st flow path is cooling water, The said 2nd flow path The fluid flowing through the engine oil is engine oil.

  Moreover, the invention which concerns on Claim 7 was further provided with the thermostat accommodating part with which the flow-path formation member as described in any one of Claims 1-6 is used for accommodation of a thermostat. .

  The invention according to claim 8 is a flow path forming member that is fastened to the internal combustion engine body and has a flow path that joins a main body flow path formed in the internal combustion engine main body. A partition that branches the flow path into a first flow path and a second flow path is provided.

  Further, the invention according to claim 9 is the flow path forming member according to claim 8, further comprising a thermostat housing portion used for housing the thermostat, and one of the first flow path and the second flow path. Is a bypass passage connected to the thermostat housing part.

  According to the flow path forming member of claim 1, for example, by fixing two types of flow paths with a common fastening member, piping around the engine can be simplified and the number of fastening parts can be reduced. . In addition, if the respective centers of gravity of the two openings are located within the polygon, a predetermined sealing property can be ensured, so that the polygon is excessively large (the fastening means are excessively separated from each other). The fastening means can be arranged at a position as close as possible. Accordingly, the size of the part can be reduced. According to the flow path forming member of claim 2, since the fastening member is not located between the first joint opening and the second joint opening, both the openings can be formed close to each other. The path forming member can be reduced in size. In addition, according to the flow path forming member of the third aspect, the fastening member can be arranged in the same direction to improve the sealing performance of both openings. In addition, according to the flow path forming member of claim 4 and claim 5, by forming the flow path expansion chamber on the mating surface, the expansion chamber formed in each member as compared with the case where the flow path expansion chamber is formed on only one of them. Can be reduced, and molding during casting becomes easy. According to the flow path forming member of claim 6, the cooling effect of the engine oil by the cooling water can be expected because the cooling water flow path and the engine oil flow path are close to each other. Furthermore, according to the flow path forming member of claim 7, it is not necessary to provide a separate thermostat case, and the number of parts can be reduced and the flow path forming member can be downsized.

  According to the flow path forming member of claim 8, two types of flow paths, such as a cooling water flow path flowing out to the radiator and a cooling water flow path flowing out to the thermostat, are separated by the partition provided in the flow path forming member. By branching into two, the engine side opening can be made a single one, facilitating molding during casting, and the manufacturing cost can be reduced. Furthermore, according to the flow path forming member of the ninth aspect, the thermostat is formed integrally with the flow path forming member, so that space saving around the engine is realized and a bypass passage that does not pass through the radiator is also formed. Therefore, it is not necessary to separately provide a bypass connection pipe.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing an engine and a cooling device. 2 is a perspective view showing the cylinder block and the flow path forming member, FIG. 3 is a front view showing the cylinder block and the flow path forming member, and FIG. 4 is a sectional view taken along line IV-IV in FIG. 5 is a VV cross-sectional view in FIG. 6 is a sectional view taken along line VI-VI in FIG. 4, and FIG. 7 is a sectional view taken along line VII-VII in FIG.

  8 is a sectional view taken along the line IV-IV in FIG. 3 according to the first embodiment, and FIG. 9 is a sectional view taken along the line IV-IV in FIG.

<< Overall Configuration and Action of Embodiment >>
An engine 1 (internal combustion engine) shown in FIG. 1 is a water-cooled four-cylinder diesel engine with a turbocharger mounted on a vehicle, and a cylinder block 3 (internal combustion engine body) in which four cylinders 2 are arranged in series. A cylinder head 4 fastened to the upper surface of the cylinder block 3 and a turbocharger 5 are included. Further, the engine 1 is provided with a cooling device 6. The cooling device 6 includes a radiator 8 for releasing heat of the cooling water into the atmosphere, and two electric radiators disposed on the rear surface of the radiator 8. The fan 9a, 9b, a thermostat 11 for controlling the temperature of the cooling water, a water pump 12 for pumping the cooling water, an expansion tank 13 for capturing the air in the cooling water flow path, and various pipes. Yes.

  Since the rotation of the engine 1 has a wide range from a low speed range to a high speed range, a thermo switch that detects the coolant temperature and switches the rotation speed of the radiator fans 9a and 9b so that cooling according to the rotation can be obtained. 10 a and 10 b are provided in the radiator 8. When the temperature of the cooling water reaches a first set temperature (for example, 90 ° C.), the thermo switch 10a starts the radiator fans 9a and 9b at a low speed, and the thermo switch 10b sets the temperature of the cooling water to the second set temperature ( For example, when the temperature reaches 100 ° C., the radiator fans 9a and 9b are driven at a high speed.

  The water pump 12 pumps cooling water to the cylinder block 3 and the cylinder head 4 when driven by the crankshaft of the engine. A cooling water flow path is provided on the side surface of the cylinder block 3, and the cooling water flows through the flow path to cool the cylinder block 3 to keep the cylinder temperature constant. The flow path forming member 50 is fastened to the cylinder block 3 to form a flow path through which cooling water flows. At the same time, the flow path forming member 50 is provided with a thermostat case 21 (thermostat accommodating portion) containing the thermostat 11. When the thermostat 11 switches the flow path, the temperature of the cooling water is controlled.

  When the temperature of the cooling water is equal to or lower than a predetermined temperature (for example, 78 ° C.), the thermostat 11 closes the cooling water passage 11a that flows from the radiator 8 through the cooling water hose 52 to shut off the cooling water. Accordingly, the cooling water flowing through the cylinder block 3 does not flow into the cooling water hose 51 connected to the radiator 8 but flows into the thermostat bypass passage 11b formed in the thermostat 11 and further passes through the connecting pipe 53 to the water. It flows into the pump 12. On the other hand, when the cooling water continues to absorb the heat of the engine 1 and reaches a predetermined temperature or more, the thermostat 11 moves to open the cooling water passage 11a and close the thermostat bypass passage 11b. The inflow is interrupted, and the cooling water flows into the radiator 8, and the water temperature is lowered by releasing heat into the air. The cooling water whose temperature has been lowered flows from the radiator 8 through the cooling water hose 52, through the thermostat 11, through the connecting pipe 53, and into the suction side of the water pump 12.

  The cylinder head 4 is connected to a pipe 61 communicating with the heater core 60, and the cooling water that has absorbed the heat of the engine 1 is used as a heat source for air conditioning. The heater core 60 is piped in parallel with the radiator 8, and the cooling water passing through the heater core 60 does not flow into the radiator 8, passes through the pipe 62, passes through the thermostat 11, passes through the connecting pipe 53, and is connected to the water pump 12. Inflow. A pipe communicating with the oil cooler 15 is connected to the discharge side of the water pump 12, and cooling water is used to cool the engine oil that has become hot. Cooling water that has passed through the oil cooler 15 flows into the suction side of the water pump 12.

  The cooling water passage of the cylinder block 3 is connected to an exhaust gas recirculation cooler (EGR / C) 16. On the other hand, the cooling water via the cooling water passage formed in the intake manifold (not shown) is formed in the exhaust gas recirculation valve (ERG / V) 17 and the exhaust gas recirculation bypass valve (EGR / BYPASS VLV) 18. It mixes with the cooling water cooled by EGR / C16 via the cooling water passage. Further, an air vent tube 19 is connected to the cylinder head 4 and connected to the radiator 8 via a breather heater 20.

<< Configuration of flow path forming member >>
As shown in FIGS. 2 to 5, the flow path forming member 50 has four bolts 41 (fastening members) on the front side (vehicle traveling direction side) of the cylinder block 3 in which the four cylinders 2 are arranged in series. It is fixed by. As shown in FIG. 4, a main body side cooling water flow path 22 (first main body side flow path) is formed on the cylinder block 3 side where the flow path forming member 50 is fixed. The cooling water circulates. The flow path forming member 50 is formed with a cooling water joint opening 23 (first joint opening) corresponding to the opening formed in the cylinder block 3 by the main body side cooling water flow path 22. The cooling water channel 24 (first channel) is provided.

  In the flow path forming member 50, the cooling water flow path 24 is branched into two by a partition wall 61. One flow path connects the main body side cooling water flow path 22 to the cooling water hose 51, and the other flow path. Forms a thermostat bypass passage 11 b and connects the main body side coolant flow path 22 to the thermostat case 21. In the present embodiment, the partition wall 61 extends to the connection surface of the flow path forming member 50 around the cooling water flow path 24 to the cylinder block 3, and the flow path forming member 50 is fixed to the cylinder block 3. Then, the tip of the partition wall 61 is extended to the surface of the cooling water joint opening 23. Further, the partition wall 61 has a pointed shape in which the wall thickness gradually decreases toward the tip.

  Cooling water that has absorbed the heat of the cylinder block 3 through the flow path formed on the side surface of the cylinder block 3, that is, the main body side cooling water flow path 22 and has reached a predetermined temperature or more, is a cooling water outlet. It flows out from a certain cooling water flow path 24 and flows into the radiator 8. The cylinder block 3 and the flow path forming member 50 are fastened to the cooling water joint opening 23, whereby the cooling water flow path having a larger cross-sectional area than the main body side cooling water flow path 22 and the cooling water flow path 24. An expansion chamber 25 (first flow path expansion chamber) is formed. An O-ring 26 is installed around the cooling water joint opening 23 of the flow path forming member 50 to ensure sealing performance.

  As shown in FIG. 5, a main body side engine oil flow path 32 (second main body side flow path) is formed on the cylinder block 3 side where the flow path forming member 50 is fixed. Engine oil circulates inside. The flow path forming member 50 is formed with an engine oil joint opening 33 (second joint opening) corresponding to the opening formed in the cylinder block 3 by the main body side engine oil flow path 32. The engine oil passage 34 (second passage) is provided.

  When the cylinder block 3 and the flow path forming member 50 are fastened to the engine oil joint opening 33, both members have a larger cross-sectional area than the main body side engine oil flow path 32 and the engine oil flow path 34. An engine oil flow passage expansion chamber 35 (second flow passage expansion chamber) is formed. An engine oil pipe 54 connected to a lubricating oil passage (not shown) of the turbocharger is connected to the end of the engine oil flow path 34 on the side opposite to the cylinder block 3, and the engine that lubricates the turbocharger. Oil flows into the engine oil passage 34. An O-ring 36 is installed around the engine oil joint opening 33 of the flow path forming member 50 to ensure sealing performance.

  The engine oil is sucked from the oil pan by the oil pump and is pumped to the oil main gallery through the oil cooler and the oil filter. In the oil main gallery, engine oil is distributed to various uses such as a valve train system, a crank journal system, and a turbocharger system. The engine oil distributed to the turbocharger system path circulates in the engine oil pipe 54, and the engine oil used for lubricating the turbocharger is supplied from the engine oil flow path 34 to the main body side engine oil. It flows into the flow path 32, falls into an oil pan disposed below, and is recycled.

  As shown in FIG. 6, on the front side of the cylinder block 3, a main body side cooling water flow path 22 that forms one side of the cooling water flow path expansion chamber 25 and a main body that forms one side of the engine oil flow path expansion chamber 35. A side engine oil passage 32 is opened. The opening of the main body side coolant flow path 22 has a shape formed by connecting two differently sized circles with tangents. On the other hand, the opening of the main body side engine oil passage 32 has a shape formed by connecting two circles of the same size by tangent lines, and both openings are formed on the same plane. Four screw holes 42 into which bolts 41 for fastening the flow path forming member 50 are fastened are arranged in the vicinity of these two openings.

  As shown in FIG. 7, the flow path forming member 50 has a cooling water joint opening 23 and an engine oil joint opening 33, and these two openings are openings of the main body side cooling water flow path 22 shown in FIG. And a shape corresponding to the opening of the main body side engine oil flow path 32, that is, a shape obtained by inverting these two openings. Similarly, in the vicinity of the cooling water joint opening 23 and the engine oil joint opening 33, four fastening boss holes 43 into which bolts 41 are inserted are arranged.

  The center of gravity Pw of the coolant joint opening 23 and the center of gravity Po of the engine oil joint opening 33 are located inside a quadrilateral L formed by connecting the centers of the four fastening boss holes 43 with straight lines. Here, the polygon in the embodiment having four or more fastening boss holes 43 does not have to be a polygon connecting all the fastening boss holes 43, and the fastening boss is a concave polygon. A combination of fastening boss holes that form a convex polygon having the maximum area excluding the holes 43 and means a polygon in which the centers of the fastening boss holes 43 are connected by straight lines. Further, the polygonal outer peripheral line represents a fastening load line by the fastening means constituting each vertex of the polygon, and the polygonal area represents an approximate region where the sealing performance is secured by the fastening means.

  The center of each fastening boss hole 43 is arranged not to be located in a region R formed by connecting the outer edge of the cooling water joint opening 23 and the outer edge of the engine oil joint opening 33 with a tangent line. Here, the tangent is generally the limit of M when Q is brought as close as possible to P when a straight line M passing through two points on the curve, P and Q, is used. When the outer edge of 23 or the outer edge of the engine oil joint opening 33 has a vertex, the straight line passing through the vertex is included.

  As shown in FIG. 6, similarly to the case where the opening of the main body side cooling water flow path 22 and the opening of the main body side engine oil flow path 32 are formed on the same plane, the cooling water joint opening 23 and the engine The oil joint opening 33 is formed on the same plane.

<Operation of flow path forming member>
As shown in FIG. 4, the cooling water flow passage expansion chamber 25 is formed on the mating surface between the cylinder block 3 and the flow passage forming member 50, so that it is formed in each member as compared with the case where the cooling water flow passage expansion chamber 25 is formed only on either one. The enlargement chamber can be made smaller, and the strength is prevented from being lost, and the manufacture is facilitated. Further, as shown in FIG. 5, like the cooling water flow passage expansion chamber 25, only one of them can be formed by forming the engine oil flow passage expansion chamber 35 on the mating surface of the cylinder block 3 and the flow passage forming member 50. Compared with the case of forming in the above, the expansion chamber formed in each member can be made smaller, and the strength is prevented from being impaired and the manufacture is facilitated.

  Further, as shown in FIG. 4, a part is formed by joining a flow path forming member 50 having two flow paths to one main body side cooling water flow path 22 formed in the cylinder block 3. The number of points is reduced and the engine assembly is improved. Further, by making the partition wall 61 have a pointed shape, an increase in flow path resistance is suppressed to a minimum, and at the time of manufacturing the flow path forming member 50, it is easy to remove a die, and productivity is improved.

  As shown in FIG. 7, the four fastening boss holes 43 are arranged so that the center of gravity Pw of the coolant joint opening 23 and the center of gravity Po of the engine oil joint opening 33 are located inside the quadrangular L, The fastening of the joint openings 23 and 33 to the cylinder block 3 is not cantilevered, and the sealing performance of the joint openings 23 and 33 is ensured. Since the number of bolts 41 is four instead of three, the flow path forming member is reduced in size. Further, the number of flow path forming members is reduced by forming the cooling water flow path 24 and the engine oil flow path 34 as one member and further including the thermostat case 21. Further, when two flow path forming members having an elongated joint opening shape such as an oval shape are fastened, three or more bolts are often used to ensure sealing performance. As a result, the number of bolts required for fastening is also reduced.

  Further, since the center of each fastening boss hole 43 is not located in the region R, the cooling water joint opening 23 and the engine oil joint opening 33 can be formed close to each other, so that the flow path including the thermostat case 21 is formed. The member 50 is downsized, and space saving in the engine room is realized. Furthermore, the cooling effect of engine oil can also be expected by arranging the cooling water joint opening 23 and the engine oil joint opening 33 close to each other.

  As shown in FIGS. 6 and 7, the cooling water joint opening 23 and the engine oil joint opening 33 are formed on the same plane, so that the bolt 41 can be arranged in the same direction. All the bolts 41 each perform a fastening function, and the sealing performance of both openings is improved.

  Although the description about specific embodiment is finished above, this invention is not limited to these embodiment. For example, the fluid flowing through the first flow path and the second flow path is not limited to cooling water and engine oil, but may be other liquids, or may be a gas such as air or exhaust gas. Good. Moreover, although the bolt is used as the fastening member in the present embodiment, the flow path forming member may be fastened using a stat bolt and a nut. Further, although four bolts are used to fasten the flow path forming member to the cylinder block, at least three bolts are sufficient.

<< Other Embodiment 1 >>
Next, another embodiment 1 in which changes are made to the embodiment of the present invention will be described. As shown in FIG. 8, the cooling water flow path 24 formed in the flow path forming member 50 is branched into two by a partition wall 61. Unlike FIG. 4 described above, the partition wall 61 of the present embodiment is The flow path forming member 50 extends further to the outer side than the connection surface to the cylinder block 3 around the cooling water flow path 24. Therefore, when the flow path forming member 50 is fixed to the cylinder block 3, the partition wall 61 is inserted into the cooling water flow path expansion chamber 25 behind the surface of the cooling water joint opening 23, and the main body side cooling water flow It fulfills the function of branching the cooling water flow passage expansion chamber 25 of the passage 22. Thereby, the flow of the cooling water in the cooling water flow path expansion chamber 25 can be controlled.

«Other embodiment 2»
Next, another embodiment 2 in which changes are made to the embodiment of the present invention will be described. As shown in FIG. 9, the cooling water flow path 24 formed in the flow path forming member 50 is branched into two by a partition wall 61, but unlike FIGS. 4 and 8 described above, The end of the partition wall 61 is installed in a state where the tip of the partition wall 61 is retracted to the inner side of the connection surface to the cylinder block 3 around the cooling water flow path 24 in the flow path forming member 50. Therefore, when the flow path forming member 50 is fixed to the cylinder block 3, the cooling water flow path expanding chamber 25 is extended in the flow path forming member 50, and the cooling water flow path expanding chamber is the same as in the first embodiment. In addition to controlling the flow of the cooling water in 25, it is possible to secure the flow path area to the thermostat bypass passage 11b when the cooling water flow path expansion chamber 25 cannot be secured in a sufficient size.

  In the other first and second embodiments, the modified embodiments of the partition wall 61 according to the embodiment of the present invention have been described, but the present invention is not limited to these embodiments. For example, the fluid flowing through the flow path is not limited to cooling water, and may be engine oil or other liquid, or may be a gas such as air or exhaust gas. Further, in the present embodiment, the cooling water flows from the cylinder block 3 side to the flow path forming member 50 side, that is, it is configured to branch from one flow path to two flow paths. The embodiment may be used in an embodiment in which the fluid flows from the flow path forming member 50 side to the cylinder block 3 side, that is, an embodiment in which two fluid paths are integrated into one flow path.

It is a conceptual diagram which shows the engine and cooling device which concern on embodiment. It is a perspective view showing a cylinder block and a channel formation member concerning an embodiment. It is a front view showing a cylinder block and a channel formation member concerning an embodiment. It is IV-IV sectional drawing in FIG. 3 which concerns on embodiment. It is VV sectional drawing in FIG. 3 which concerns on embodiment. It is VI-VI sectional drawing in FIG. 4 which concerns on embodiment. It is a VII-VII sectional view in Drawing 4 concerning an embodiment. It is IV-IV sectional drawing in FIG. 3 which concerns on other Embodiment 1. FIG. It is IV-IV sectional drawing in FIG.

Explanation of symbols

1 Engine 3 Cylinder block (Internal combustion engine body)
11 Thermostat 11b Thermostat bypass passage (bypass passage)
21 Thermostat case (thermostat housing)
22 Body side cooling water flow path (first body side flow path)
23 Cooling water joint opening (first joint opening)
24 Cooling water channel (first channel)
25 Cooling water channel expansion chamber (first channel expansion chamber)
32 Body side engine oil passage (second body side passage)
33 Engine oil joint opening (second joint opening)
34 Engine oil passage (second passage)
35 Engine oil passage expansion chamber (second passage expansion chamber)
41 Bolt (fastening member)
50 Flow path forming member 61 Partition Pw Center of gravity Po of cooling water joint opening 23 Center of gravity L of engine oil joint opening 33 Polygonal R region

Claims (9)

A first flow path that joins a first body side flow path formed in the internal combustion engine body with a first joint opening, and a second flow path that joins a second body side flow path formed in the internal combustion engine body with a second joint opening. A flow path forming member that is fastened to the internal combustion engine body by at least three fastening members,
The center of gravity of the first joint opening and the center of gravity of the second joint opening are located inside the polygon having the largest area among the polygons formed by connecting the centers of the fastening members with straight lines. A flow path forming member.   2. The flow according to claim 1, wherein the center of each fastening member is not located in a region formed by connecting an outer edge of the first joint opening and an outer edge of the second joint opening with a tangent line. Road forming member.   The flow path forming member according to claim 1, wherein the first joint opening and the second joint opening are formed on the same plane.   The first flow path expansion chamber is formed between the first main body flow path and the first flow path by being joined to the internal combustion engine main body. The flow path forming member according to any one of the above.   4. A second flow passage expansion chamber is formed between the second main body flow passage and the second flow passage by being joined to the internal combustion engine main body. The flow path forming member according to any one of the above.   6. The fluid according to claim 1, wherein the fluid flowing through the first flow path is cooling water and the fluid flowing through the second flow path is engine oil. A flow path forming member.   The flow path forming member according to any one of claims 1 to 6, further comprising a thermostat housing portion for housing the thermostat. A flow path forming member fastened to an internal combustion engine body and having a flow path joined to a main body flow path formed in the internal combustion engine main body,
A flow path forming member comprising a partition wall that faces the main body side flow path and branches the flow path into a first flow path and a second flow path. It further comprises a thermostat housing part used for housing the thermostat,
9. The flow path forming member according to claim 8, wherein either one of the first flow path and the second flow path is a bypass passage connected to the thermostat housing portion.

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