Flow path switching valve

Abstract

A flow path switching valve is used in an engine water cooling system (900) mounted on a mounting surface (99) of an engine (90) to switch the flow path of cooling water in the engine water cooling system. The engine water cooling system has a cylinder block sleeve (93) formed on a cylinder block (91) and a cylinder head sleeve (97) formed on a cylinder head (96), which are connected to each other via a communication channel. Cooling water flowing in from the inlet of the cylinder block sleeve flows through the communication channel from the outlet (98) of the cylinder head sleeve into the inlet port (11) of the flow path switching valve. An inflow baffle (361) is provided, which closes a portion of the leakage path (94) side of the inlet port (11) to inhibit the flow of cooling water from the cylinder block sleeve through the leakage path (94) formed in the cylinder block (91) and cylinder head (96).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a flow path switching valve. BACKGROUND

[0002] Conventionally, a flow path switching valve that switches a flow path of cooling water of an engine water cooling system (i.e., engine water cooling system hereinafter) by operation of a valve is known.

[0003] For example, according to the disclosure in Patent Literature 1 (Japanese Unexamined Patent Publication No. 2018-54122), cooling water flows into a flow path switching valve via a cylinder block and a cylinder head of an engine. The flow path switching valve rotates a valve body to switch a flow path of the cooling water, and supplies the cooling water to a radiator, an oil cooler, and an air conditioning heat exchanger.

[0004] In the engine of Patent Literature 1, the cooling water is designed to flow from a cylinder block jacket of the cylinder block to a cylinder head jacket of the cylinder head through a communication passage and to an inlet port of the flow path switching valve. However, due to manufacturing factors of the engine, a leakage path that directly communicates from the cylinder block jacket to the inlet port of the flow path switching valve can be unintentionally formed. If a portion of the low-temperature cooling water that should flow to the cylinder head flows through the leakage path, the cooling efficiency of the cylinder head decreases. Further, if the low-temperature cooling water is supplied from the flow path switching valve to the air conditioning heat exchanger, the heating performance can deteriorate. SUMMARY

[0005] An object of the present disclosure is to provide a flow path switching valve that can suppress a decrease in cooling efficiency even when a leakage path that communicates from a cylinder block jacket to an inlet port is formed.

[0006] The present disclosure relates to a flow path switching valve that is used in an engine water cooling system mounted on a mounting surface of an engine, and switches a flow path of cooling water by operation of a valve.

[0007] The engine water cooling system has a cylinder block jacket that is a water jacket formed on a cylinder block, and a cylinder head jacket that is a water jacket formed on a cylinder head, and the cylinder block jacket and the cylinder head jacket are connected to each other via a communication passage. Cooling water in the engine water cooling system that flows in from an inlet of the cylinder block jacket is configured to flow in from an outlet of the cylinder head jacket to an inlet port of the flow path switching valve via the communication passage.

[0008] The flow path switching valve has an inflow blocking plate provided therein that closes a portion of a leakage path side at the inlet port to suppress inflow of the cooling water from the cylinder block jacket via the leakage path formed in the cylinder block and the cylinder head.

[0009] In the present disclosure, it is not necessary to completely prevent inflow of the cooling water from the leakage path, but it is only necessary to relatively suppress the inflow thereof. "Suppressing inflow of the cooling water from the leakage path" means that pressure loss of the cooling water flowing through the leakage path becomes larger than pressure loss of the cooling water flowing from the cylinder cover jacket.

[0010] Therefore, in the present disclosure, even if the leakage path is formed from the cylinder jacket to the inlet port due to a manufacturing factor of the engine, inflow of the cooling water to the flow path switching valve via the leakage path can be suppressed. Therefore, reduction in cooling efficiency of the cylinder head and reduction in heating performance of the air conditioning heat exchanger can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0011] Objects, features and advantages of the present disclosure will become more apparent from the following detailed description made in conjunction with the accompanying drawings, in which:

[0012] Figure 1 is a configuration view of an engine cooling system including a flow path switching valve according to an embodiment;

[0013] Figure 2 is a perspective view of the flow path switching valve according to the embodiment;

[0014] Figure 3 is a cross-sectional view of the flow path switching valve according to the embodiment;

[0015] Figure 4 is a schematic cross-sectional view of a flow path switching valve of a comparative example;

[0016] Figure 5 is a front view of an inlet port portion of the flow path switching valve according to a first embodiment;

[0017] Figure 6 is a schematic cross-sectional view taken along the line VI-VI of Figure 5 ;

[0018] Figure 7 is a front view of an inlet port portion of the flow path switching valve according to a second embodiment;

[0019] Figure 8 is a schematic cross-sectional view taken along the line VIII-VIII of Figure 7 ;

[0020] Figure 9 is a schematic cross-sectional view of an inlet port portion of the flow path switching valve according to a third embodiment;

[0021] Figure 10 is a front view of an inlet port portion of the flow path switching valve according to a fourth embodiment;

[0022] Figure 11 is a schematic cross-sectional view taken along the line IX-IX of Figure 10A schematic cross-sectional view taken along the XI-XI line; and

[0023] Figure 12 This is a schematic cross-sectional view of the inlet port of the flow path switching valve according to the fifth embodiment. Detailed Implementation

[0024] In the following description, several embodiments of the flow path switching valve according to the present disclosure are described with reference to the accompanying drawings. The substantially identical constructions in the various embodiments are indicated by the same reference numerals, and their description may be omitted. The first to fifth embodiments described below can be collectively referred to as "this embodiment". The flow path switching valve of this embodiment is mounted on the mounting surface of the engine, and the operation of the valve switches the flow path of the cooling water in the engine water cooling system. The basic purpose and function of the flow path switching valve are the same as those disclosed in Patent Document 1 (Japanese Unexamined Patent Publication No. 2018-54122).

[0025] [Engine Cooling System]

[0026] First, refer to Figure 1 The structure of the engine cooling system is described. The engine 90 includes a cylinder block 91 mounted at the lower part and a cylinder head 96 mounted at the upper part. A cylinder block sleeve 93, which serves as a water jacket, is formed on the cylinder block 91. A cylinder head sleeve 97, which serves as another water jacket, is formed on the cylinder head 96. The cylinder block sleeve 93 and the cylinder head sleeve 97 are connected to each other via a (main or vertical) connecting passage 95.

[0027] In the cylinder head 96, a flow path switching valve 100, used to switch the flow path of coolant in the engine cooling system 900 by valve operation, is mounted on the mounting surface 99 of the engine 90. As shown by the solid arrow, (primary or secondary) coolant Wc flows in from the inlet 92 of the cylinder block sleeve 93 via the connecting passage 95 from the outlet 98 of the cylinder head sleeve 97 into the inlet port 11 of the flow path switching valve 100. As the coolant Wc passes through the cylinder block 91 and the cylinder head 96, the temperature of the coolant Wc increases due to heat exchange with the engine 90.

[0028] The engine cooling system 900 includes a radiator 86, an oil cooler 87, an air conditioning heat exchanger 88, and a water pump 89. A flow path switching valve 100 switches the flow path for supplying cooling water to the radiator 86, oil cooler 87, and air conditioning heat exchanger 88. In the radiator 86, heat is released from the already heated cooling water. The oil cooler 87 cools the lubricating oil. In the air conditioning heat exchanger 88, heat exchange occurs to heat the air inside the vehicle. The cooling water discharged from the radiator 86, oil cooler 87, and air conditioning heat exchanger 88 is recirculated to the cylinder liner 93 of the engine 90 via the water pump 89.

[0029] Currently, due to manufacturing factors of the engine 90, such as cavities and core structures in the casting process, a leakage path 94 may unintentionally form, connecting directly from the cylinder block sleeve 93 to the inlet port 11 of the flow path switching valve 100. In this case, as indicated by the dashed arrow, coolant WL flows from the cylinder block sleeve 93 into the inlet port 11 of the flow path switching valve 100 via the leakage path 94. In the following text, when distinguishing the location of coolant inflow into the flow path switching valve 100, the (main) coolant from the cylinder head sleeve 97 is marked "Wc," and the (leaked) coolant from the leakage path 94 is marked "WL." To avoid misreading the lowercase "L(e1)" as the number "1," the uppercase letter "L" is used in "WL."

[0030] If a portion of the cryogenic coolant that should flow to the cylinder head 96 flows through the leakage path 94, the cooling efficiency of the cylinder head 96 decreases. Furthermore, if cryogenic coolant is supplied from the flow path switching valve 100 to the air conditioning heat exchanger 88, heating performance may also decrease / deteriorate. In response to this situation, in addition to measures to prevent the unintentional formation of the leakage path 94 on the engine 90, in this embodiment, from the viewpoint of the flow path switching valve 100, the focus is on preventing / suppressing the inflow of coolant WL from the leakage path 94.

[0031] [Flow path switching valve]

[0032] Next, refer to Figure 2 and Figure 3 The basic construction of the flow path switching valve 100, which is common to each of the following embodiments, is described. Figure 2 This is a perspective view corresponding to Figure 16 of Patent Document 1. Figure 3 It is related to Patent Document 1 Figure 1 The corresponding axial section view. Note that, for clarity, the orientation of the pipe fittings and connectors in the section view has been adjusted. Figure 2 and Figure 3 In the drawing, the shape of the support member 311 in the first embodiment is shown as a support member, and the reference numeral "311" is attached to the support member of the first embodiment. However, the specific details of the first embodiment are not mentioned here, but will be discussed later. Figure 5 and Figure 6 Describe it.

[0033] The flow path switching valve 100 of this embodiment is a valve with the following structure, wherein the valve body 20 rotates to switch the flow path of cooling water. Details of the switching will be discussed later. The flow path switching valve 100 includes a housing 10, a valve body 20, a shaft 25, a support member 311, etc. The housing 10 is made of resin and has a valve body receiving portion 12, which has an opening on the surface providing the engine mounting portion 19. A rotary drive unit 15 for rotating the valve body 20 is provided on the side opposite to the opening of the valve body receiving portion 12. Radiator pipe connector 16, oil cooler pipe connector 17 (in...) Figure 2 As shown in the text, but Figure 3 (Not shown in the image) and air conditioning duct connector 18 are provided on the exterior of housing 10 (e.g., on the outer surface). An annular gasket 71, as a sealing member, is attached to engine mounting portion 19 around the opening of valve body receiving portion 12.

[0034] The valve body 20 is formed of resin into a generally bottomed cylindrical shape and is rotatably housed in the valve body receiving portion 12 about the valve axis X. The cylindrical wall of the valve body 20 has a communication hole 21 formed thereon, communicating with a radiator pipe and an air conditioning pipe (such as...). Figure 3 (Shown) A connecting hole 23 communicates with the oil cooler pipe (not shown). A shaft 25, forming the rotation axis of the valve body 20, is embedded in the bottom 24 of the valve body 20. When the rotation drive unit 15 rotates the shaft 25 to the desired position, the connecting holes 21 and 23 and the positions of each pipe are matched, thereby allowing cooling water in the valve body 20 to flow out to those pipes. Figure 3 For ease of illustration, in this embodiment, the (radiator) connecting hole 21 is connected (aligned) with the radiator pipe connector 16, and the (air conditioning) connecting hole 23 is simultaneously connected (aligned) with the air conditioning pipe connector 18. In another embodiment (not shown), as the valve body 20 rotates, connecting holes 21 and 23 are actually connected to the pipe alternately. In another embodiment (not shown), proportional control is provided when the valve body 20 rotates, for example, in a first rotational position, 25% flows to the radiator pipe connector 16, and 50% flows to the air conditioning pipe connector 18, and 25% flows to the oil cooler pipe connector 17. Additionally, there may be rotational positions (not shown) where little or no coolant leaves the engine (when the engine is cold). Historically, mechanical temperature-sensitive valves performed this cold engine blocking function.

[0035] The support member 311 is made of resin and is coaxially disposed at its end on the engine mounting portion 19 side with the valve axis X to cover the opening of the valve body 20. The support member 311 supports one end of the shaft 25 via a bearing 26 disposed in its central hole. The support member 311 is provided with a plurality of ribs 35 radially connecting the central portion 33 and the peripheral portion 34. The space between adjacent ribs 35 serves as an inlet port 11 for cooling water Wc to flow in from the cylinder head sleeve 97. The engine side surface of the support member 311 can be used as an integral inflow baffle 361 (see [link to relevant documentation]). Figure 3 , Figure 5 and Figure 6 Alternatively, Figure 8 The (different) inflow baffle 402 may be different from the support member 322 (see [link]). Figure 8 The second embodiment and Figure 9 (The third embodiment in the text).

[0036] Subsequently, referring to Figure 4 This illustrates the state of a comparative flow path switching valve 109 attached to the mounting surface 99 of the engine 90. (Simplified) Figure 3 The diagram illustrates the basic structure of the flow path switching valve 109. When the flow path switching valve 109 is attached to the engine 90, coolant Wc flows from the outlet 98 of the cylinder head sleeve 97 through the inlet port 11 (formed between the ribs 35 of the support member 311) into the interior of the valve body 20. A gasket 71, located in the gasket groove 197 of the engine mounting portion 19, prevents coolant from leaking from the mounting surface 99 to the outside.

[0037] exist Figure 4 In the comparative example, the flow path switching valve 109 corresponds to the valve device of Patent Document 1 and does not have the inflow baffle plate of this embodiment. Therefore, the cooling water WL from the leakage path 94 also flows into the valve body 20 through the inlet port 11 formed between the ribs 35 of the support member 311. As a result, as described above, the cooling efficiency of the cylinder head 96 may be reduced and the heating performance may be reduced.

[0038] Therefore, the flow path switching valve 100 of this embodiment has an inflow baffle plate configured to block a portion of the leakage path 94 side of the inlet port 11, for preventing / inhibiting cooling water from flowing into the inlet port 11 via the leakage path 94.

[0039] [Inflow barrier]

[0040] In the following text, see references Figures 5 to 12This describes the construction of the inflow baffle in the flow path switching valve of the first to fifth embodiments. The inflow baffles in the following embodiments are classified / distinguished as follows: <1> Is the gasket configured as a "sealing element that separates the space on the cylinder head sleeve 97 side from the space on the leakage path 94 side", and <2> The inflow baffle is either integrally disposed with the support member or separately disposed from the support member (i.e., the inflow baffle and support member have an integral structure or the inflow baffle is a separate body). The reference numerals for the flow path switching valve in each of the following embodiments are "10" followed by the embodiment number as the third digit. Furthermore, the third digit of the reference numerals for the inflow baffle in each of the following embodiments corresponds to the embodiment number. For example, Figure 6 (First embodiment) shows a flow path switching valve 101 and a support member 311. Furthermore, Figure 8 (Second embodiment) shows the flow path switching valve 102 and the support member 322.

[0041] In each of the following embodiments, the view of the inflow baffle is shown as a front view from the outlet 98 side of the cylinder head sleeve 97 and a schematic cross-sectional view in the X direction of the valve axis. However, the front view is omitted in the third and fifth embodiments. In the schematic cross-sectional view, relative to... Figure 4 The comparative example in the figure omits the portion outside the periphery of the inlet port 11 of the housing 10 and the valve body 20.

[0042] For convenience, Figures 5 to 12 In the diagram, the portion shown above the valve axis X can be referred to as the "upper half," and the portion shown below the valve axis X can be referred to as the "lower half." The upper half of each schematic cross-sectional view shows the cross-section of the support member not at / excluding rib 35. In the second embodiment... Figure 8 The lower half shows a cross-section of a portion of the rib 35 of the support member.

[0043] (First embodiment, Figure 5 , Figure 6 )

[0044] Reference Figure 5 and Figure 6 The flow path switching valve 101 of the first embodiment is described. The (integral) inflow baffle 361 (also referred to as an inflow baffle "surface" in the integrated embodiment) of the first embodiment is integrally disposed with the support member 311, both made of resin. In the first embodiment, the support function of the support member 311 at one end of the shaft 25 is achieved by using the bearing 26 to support the shaft 25. Figure 4 The comparative example shown has the same support function. However, the comparative example does not have a baffle plate that limits or blocks any inflow of leaking cooling water WL.

[0045] The support member 311 has a plurality of ribs 35 that radially connect the central portion 33 and the peripheral portion 34 in the upper half region facing the outlet 98 of the cylinder head sleeve 97. The space between adjacent ribs 35 serves as an inlet port 11 for cooling water Wc to flow in from the cylinder head sleeve 97. As indicated by the solid arrow (in... Figure 6 In the middle), cooling water Wc flows from cylinder head sleeve 97 into the interior of housing 10 without obstruction.

[0046] Furthermore, in the support member 311, a wall-shaped inflow baffle 361 without any holes is formed in the lower half of the portion (surface) facing the leakage path 94. The inflow baffle 361 blocks a portion of the inlet port 11 on the leakage path 94 side to prevent (leaked) cooling water WL from flowing in from the cylinder liner 93 via the leakage path 94. Figure 6 The dashed arrows showing / representing (leaked) cooling water WL indicate suppression of its inflow. Suppression can be a complete blockage, or it can, for example, reduce the (leaked) cooling water WL by 50% relative to the comparison scale. Figure 6 In the middle, a very small amount of (leaked) cooling water WL can move vertically upward (through the small gap between the inflow baffle 361 and the mounting surface 99) and join the (main) cooling water Wc.

[0047] In other words, in the first embodiment, the leaking coolant WL that has passed through the leakage path 94 can reach and leak into the inlet port 11 on the cylinder head liner 97 side through the gap between the end face 37 of the inflow baffle 361 and the mounting surface 99 of the engine 90. However, in this embodiment, it is not necessary to completely block the inflow of leaking coolant WL from the leakage path 94; it is sufficient to relatively suppress the inflow. "Suppressing the inflow of leaking coolant WL from the leakage path" means reducing or stopping the flow rate of leaking coolant WL.

[0048] Therefore, in this embodiment, even when a leakage path 94 is formed due to manufacturing factors of the engine 90, allowing communication from the cylinder block liner 93 to the inlet port 11, the flow of (leaked) coolant WL through the leakage path 94 into the flow path switching valve 101 is suppressed (reduced or blocked). Thus, a decrease in (i) the cooling efficiency of the cylinder head 96 and a decrease in the heating performance of the air conditioning heat exchanger 88 can be suppressed. Note that it may be desirable to intentionally allow a small amount of (leaked) coolant WL to flow.

[0049] Furthermore, in the first embodiment, since the inflow baffle 361 is integrally provided with the support member 311, the function of the inflow baffle can be achieved with a minimum number of components.

[0050] (Second Embodiment)

[0051] Reference Figure 7 andFigure 8 The flow path switching valve 102 of the second embodiment is described. In the second embodiment, the inflow baffle 402 is separately disposed from the support member 322 and is preferably made of a metal plate such as stainless steel. Figure 7 As shown by the dashed lines, the support member 322 has ribs 35 arranged radially in all directions (including downwards). The (non-integral) support member 322 roughly corresponds to that in Patent Document 1. Figure 4 The structure disclosed in [etc.].

[0052] The inflow baffle 402 has a circular shape and a generally semi-circular window portion 41 that allows cooling water to flow from the cylinder head sleeve 97 side into the inlet port 11. The inflow baffle 402 is adhered to, for example, the inner circumference of a gasket 71, or embedded into the gasket 71. By mounting the gasket 71 in the gasket groove 197 of the housing 10, the inflow baffle 402 covers the end faces of five of the ribs 35 of the support member 322, such as... Figure 7 As shown.

[0053] Here, for example, a step 352 that partially protrudes and contacts the inflow baffle 402 can be formed on the end face (engine side surface) of the rib 35 of the support member 322. By supporting (supporting or reinforcing) the inflow baffle 402 with the surface pressure of some of the step portions 352 of the rib 35, deformation of the inflow baffle 402 due to water pressure can be prevented. In the second embodiment, as in the first embodiment, the inflow of cooling water WL from the leakage path 94 is suppressed. Furthermore, the strength of the inflow baffle 402 is ensured by using a metal inflow baffle 402. In addition, when repairing an existing flow path switching valve, it can be repaired at low cost and in a short time by simply replacing the metal inflow baffle 402 and possibly the annular gasket 71 that can be integral with the inflow baffle 402.

[0054] (Third embodiment,) Figure 9 )

[0055] Reference Figure 9 The flow path switching valve 103 of the third embodiment is described. In the third embodiment, the inflow baffle 503 is separately disposed from the support member 323, which is made of metal such as stainless steel or resin. Similar to the second embodiment, the support member 323 is provided with ribs 35 extending radially in all directions. Figure 9 (Not shown in the diagram). The inflow baffle 503 has a plate portion 56 covering the lower half of the support member 323 and a mounting protrusion 58 protruding along the valve axis X toward the support member 323. The outer diameter of the mounting protrusion 58 is set to be slightly larger than the inner diameter of the mounting hole 38 of the support member 323. The inflow baffle 503 is fixed by press-fitting the mounting protrusion 58 into the mounting hole 38 of the support member 323. Even with this structure, the same effect as in the second embodiment can be obtained.Figure 9 In the third embodiment, the inflow baffle 503 does not necessarily have to contact the annular washer 71.

[0056] (Fourth embodiment, Figure 10 and 11 )

[0057] Fourth embodiment ( Figure 10 and 11 Similar to the first embodiment ( Figure 6 The fourth embodiment adds a cross portion 745 to the annular gasket 71 to significantly reduce (or terminate) (leaking) cooling water WL. Figure 6 There is a potential for small vertical upward flow in the gap between the support member 311 and the mounting surface 99 shown.

[0058] Reference Figure 10 and Figure 11 The flow path switching valve 104 of the fourth embodiment will be described. Similar to the inflow baffle 361 of the first embodiment, the inflow baffle 364 of the fourth embodiment is integrally provided with the support member 314 made of resin. Furthermore, in the inflow baffle 364 of the fourth embodiment, a gasket groove 377 is formed on the end face 37.

[0059] The gasket 74 used in the fourth embodiment has an "θ-shape," comprising a ring portion 740 and a cross portion 745 connecting / bridging opposite portions of the ring portion 740. The ring portion 740 of the gasket 74 is installed in the gasket groove 197 of the housing 10, and the cross portion 745 of the gasket 74 is installed in the gasket groove 377 of the inflow baffle plate 364. The cross portion 745 of the gasket 74 separates the space allowing communication from the cylinder head sleeve 97 to the inlet port 11 from the space allowing communication from the leakage path 94 to the inlet port 11. As a result, the inflow of cooling water WL from the leakage path 94 is further suppressed.

[0060] (Fifth embodiment, Figure 12 )

[0061] Reference Figure 12 The flow path switching valve 105 of the fifth embodiment is described below. Similar to the inflow baffle 503 of the third embodiment, the inflow baffle 505 of the fifth embodiment is provided separately from the support member 323 made of metal such as stainless steel or resin. The inflow baffle 505 is fixed by press-fitting the mounting protrusion 58 into the mounting hole 38 of the support member 323.

[0062] Furthermore, the inflow baffle plate 505 of the fifth embodiment has a relatively thick plate thickness, and a washer groove 577 is formed on the end face 57. As in the fourth embodiment, a θ-shaped washer 74 is installed in the washer groove 577. Therefore, the same effect as in the fourth embodiment can be achieved. In addition, an O-ring 8 can be provided on the outer periphery of the inflow baffle plate 505.

[0063] (Other embodiments)

[0064] (a) The structure of the flow path switching valve is not limited to the structure in which the cooling water flow path is switched by rotating the valve body 20, and can also be implemented by any method such as a sliding method, as long as the method can switch the flow path. In addition, there are no restrictions on the number of flow paths to be switched and the type of target device to which the cooling water is supplied via each flow path.

[0065] (b) The leakage path 94 caused by manufacturing factors is not limited to one path, and it can be made into multiple paths. In addition, the portion forming the leakage path 94 can vary from engine 90 to engine 90. In view of this reality, the inflow baffle of this disclosure does not need to cover all leakage paths 94, but can be configured to cover only the portion of the leakage path 94 with a large amount of leakage, in order to suppress / reduce the total inflow of cooling water.

[0066] As described above, this disclosure is not limited to the above embodiments, but can be implemented in various forms without departing from its spirit.

Claims

1. A flow path switching valve configured for use in an engine water cooling system, configured to be mounted on a mounting surface of an engine, and configured to switch the flow path of cooling water by operation of the flow path switching valve, the engine water cooling system comprising: a cylinder block sleeve as a water jacket formed on a cylinder block, and a cylinder head sleeve as a water jacket formed on a cylinder head, the cylinder block sleeve and the cylinder head sleeve being connected via a communication channel, the flow path switching valve being configured as follows: Cooling water flowing in from the inlet of the cylinder liner flows through the connecting channel from the outlet of the cylinder head liner into the inlet port of the flow path switching valve, and The flow path switching valve has an inflow baffle plate disposed therein, which closes a portion of the leakage path side at the inlet port to inhibit the flow of cooling water from the cylinder sleeve via the leakage path formed in the cylinder block and the cylinder head.

2. The flow path switching valve according to claim 1, wherein... A sealing member is provided at a location between the end face of the inflow baffle and the mounting surface of the engine, the sealing member separating the space that allows communication from the cylinder head sleeve to the inlet port from the space that allows communication from the leakage path to the inlet port.

3. The flow path switching valve according to claim 1 or 2, wherein... The flow path switching valve switches the flow path of the cooling water by rotating the valve body. The inflow baffle plate is integrally disposed with the support member, and the support member supports one end of the shaft that serves as the rotation shaft of the valve body.

4. The flow path switching valve according to claim 1 or 2, wherein The flow path switching valve switches the flow path of the cooling water by rotating the valve body. The inflow baffle plate is separately disposed from the support member, and the support member supports one end of the shaft that serves as the rotation shaft of the valve body.

5. A flow path switching valve configured to be mounted to an engine, and comprising: A housing configured to be mounted to the mounting surface of the engine; axis; The valve body is configured to rotate about the valve axis; Support member, configured to retain bearing and comprising: (i) An inlet port configured to receive and allow unleashed cooling water from the outlet of the cylinder head liner of the engine to pass through, such that the unleashed cooling water enters the valve body, and (ii) an end face facing the mounting surface, and Wherein, at least a portion of the end face forms an inflow baffle plate, the inflow baffle plate being an integral part of the support member, and The inflow baffle is configured to prevent leaked cooling water from flowing into the valve body.

6. The flow path switching valve according to claim 5, further comprising: Annular washer, The outer periphery of the support member is configured to contact the inner surface of the housing, and The housing includes a washer groove with its opening facing the engine mounting portion and is configured to retain the annular washer.

7. The flow path switching valve according to claim 6, wherein, The support member includes: The peripheral portion extends semi-circularly around the valve axis. The central part, and At least three ribs extend radially outward from the central portion toward the peripheral portion.

8. A flow path switching valve configured to be mounted to an engine, and comprising: A housing configured to be mounted to the mounting surface of the engine; axis; The valve body is configured to rotate about the valve axis; Support member, configured to retain bearing and comprising: (i) Central part, (ii) the circular perimeter and (iii) a rib extending radially from the central portion to the circular peripheral portion, wherein the central portion, the circular peripheral portion, and the rib define an opening; and The inflow baffle plate is different from the supporting member. The inflow baffle includes a substantially semi-circular window portion configured to receive and allow unleashed cooling water from the outlet of the engine's cylinder head liner to pass through, such that the unleashed cooling water further passes through at least one of the orifices and enters the valve body. The inflow baffle is configured to prevent leaked cooling water from entering the valve body.

9. The flow path switching valve according to claim 8, The circumferential outer surface of the support member contacts the first inner surface of the housing. The circumferential outer surface of the inflow baffle plate is in contact with or integrally formed with the annular gasket, and The annular washer contacts the second inner surface of the housing.

10. The flow path switching valve according to claim 9, The first inner surface has a first diameter. The second inner surface has a second diameter, and The first diameter is smaller than the second diameter.

11. The flow path switching valve according to claim 8, in, At least some of the ribs include stepped portions that extend toward the inflow baffle and are configured to at least partially support the inflow baffle.

12. The flow path switching valve according to claim 11, in, The housing includes a washer groove shaped to retain the annular washer. The washer groove is partially defined by the inner wall of the washer groove. The inner wall of the washer groove has a radial inner surface with the first diameter and a radial outer surface with the second diameter. The inner wall of the gasket groove is configured to at least partially support the inflow baffle.

13. The flow path switching valve according to claim 8, further comprising: The intersection portion, which is integrally formed with or adjacent to the annular washer to form a θ-shaped washer, and in, The cross section is configured to prevent leaking cooling water from entering the valve body.

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