Thermostat

Abstract

A thermostat 1 comprises an opening / closing valve 20, a body 30, first piping 41, second piping 42, third piping 43, and fourth piping 44. A valve body 23 releasably closes the first piping 41. The body 30 comprises a flow inlet 31, an accommodation space 32, an outlet passage 33, and a partitioning wall 34. The partitioning wall 34 comprises a recessed section 34a that is recessed from the accommodation space 32 toward the outlet passage 33, the section of the recessed section 34a that is furthest to the outlet passage 33 side has a first surface 34b that is perpendicular to an attachment surface 36, and the first surface 34b is continuous with the edge of the flow inlet 31.

Description

thermostat

[0001] The present invention relates to a thermostat.

[0002] Conventionally, a thermostat provided in a cooling circuit that circulates a coolant to cool an automobile engine has been known (see, for example, Japanese Patent Application Laid-Open No. 2023-81141). The thermostat disclosed in Japanese Patent Application Laid-Open No. 2023-81141 is provided on the inlet side of the engine.

[0003] JP 2023-81141 A

[0004] When a thermostat is installed on the engine outlet side of the cooling circuit, if it is desired to reduce pressure loss in the coolant flowing to the radiator, one option is to enlarge the thermostat body to increase the flow rate of coolant to the radiator. However, because automobiles are equipped with various components, there is a limit to how large the thermostat body can be due to the space available for installation.

[0005] SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a thermostat that can reduce pressure loss in the flow of coolant toward a radiator without increasing the size of the body.

[0006] In order to achieve the above object, a thermostat of the present invention comprises an on-off valve, a body that houses the on-off valve, and first, second, third and fourth pipes that are respectively connected to the body, the first pipe directing coolant to a radiator and the second pipe returning coolant from the radiator, the on-off valve comprising a thermoelement case, a piston that is movable in a protruding direction from the thermoelement case due to expansion of contents in the thermoelement case, a valve body fixed to the thermoelement case, and a biasing member that biases the valve body in the protruding direction of the piston, the valve body releasably closing the first pipe, The body is provided at the coolant outlet of the engine and comprises an inlet for taking in coolant, a storage space communicating with the inlet, an outlet passage arranged alongside the storage space and connected to the second pipe to return coolant from the radiator, a partition wall separating the storage space from the outlet passage, a bypass path for directing coolant in the storage space to the outlet passage, and a flat mounting surface arranged to surround the inlet, wherein the partition wall has a recessed portion recessed from the storage space toward the outlet passage, and the surface of the recessed portion closest to the outlet passage on the storage space side has a first surface perpendicular to the mounting surface, and the first surface is continuous with the edge of the inlet.

[0007] With this configuration, the recessed portion increases the cross-sectional area of ​​the coolant flow path around the valve body, reducing the pressure loss of the coolant to the first pipe connected to the radiator when the valve body is open. Furthermore, because the recessed portion is recessed toward the outlet passage, the pressure loss of the coolant flowing toward the radiator can be reduced more than before without increasing the size of the body.

[0008] In the thermostat, the corners of the recess may have a uniform thickness and be curved so that the flow path cross-sectional area of ​​the outlet passage increases toward the downstream side of the outlet passage.

[0009] With this configuration, the corners of the recess are curved, allowing the coolant to flow smoothly without stagnating at the corners of the recess. In addition, the corners of the recess have a uniform thickness, and the flow path cross-sectional area increases toward the lower side of the outlet passage, allowing the coolant to flow smoothly in the outlet passage.

[0010] In the thermostat, the minimum flow passage area in the region of the body where the recessed portion is provided may be set to be larger than the minimum flow passage area of ​​the second pipe.

[0011] With this configuration, by providing a recess, the minimum flow area of ​​the outlet passage in the area where the recess is provided is smaller than that of the outlet passage of a conventional thermostat, but is set larger than the minimum flow area of ​​the second piping. Therefore, even if the partition wall is moved in a direction that narrows the outlet passage by providing a recess, the flow of coolant in the outlet passage is not impeded, and the pressure loss in the outlet passage does not increase significantly.

[0012] In addition, in the thermostat, the body may have a baffle wall that extends perpendicular to the first surface of the recess and has a second surface that is parallel to the mounting surface, and the second surface of the baffle wall may be positioned to coincide with the edge of the communication port of the third piping that is closest to the mounting surface.

[0013] With this configuration, the obstruction wall can prevent the coolant that has entered the recessed portion from flowing smoothly into the third pipe, thereby preventing excessive coolant from flowing into the third pipe and ensuring a sufficient flow rate into the first pipe.

[0014] Furthermore, in the thermostat, one end of the first pipe is inserted into the body, and when viewed from the first pipe, the direction toward the one end of the first pipe is defined as a first direction, and the direction away from the body on the opposite side of the one end of the first pipe is defined as a second direction.The body has a straightening surface located between the inlet and the connection port of the first pipe, and when an imaginary plane extending the straightening surface is defined as an extension plane, the one end of the first pipe may be located away from the extension plane in the second direction.

[0015] With this configuration, the coolant that enters through the inlet and flows along the flow-straightening surface can flow into the first pipe without being obstructed by colliding with the inlet-side edge of the tip edge of the first pipe.

[0016] Fig. 1 is a perspective view showing a thermostat according to an embodiment of the present invention. Fig. 2 is a perspective view showing a partially cutaway cross section of the thermostat according to this embodiment in a closed valve state. Fig. 3 is a perspective view showing a partially cutaway cross section of the thermostat according to this embodiment in an open valve state. Fig. 4 is a cross-sectional view showing, partially in cross section, the positional relationship between the baffle wall of the thermostat according to this embodiment and the communication port of the third pipe. Fig. 5 is a cross-sectional view showing, partially in cross section, the positional relationship between the edge of the first pipe of the thermostat according to this embodiment and the flow straightening surface. Fig. 6 is a cross-sectional view showing, partially enlarged, Fig. 5.

[0017] A thermostat according to an embodiment of the present invention will be described in detail with reference to the drawings. Referring to Fig. 1, a thermostat 1 according to this embodiment is provided in a cooling circuit that cools an engine (not shown) of an automobile (not shown) with a coolant circulating therethrough, and is disposed on the coolant outlet side from the engine (not shown). The thermostat 1 includes an on-off valve 20, a body 30 that houses the on-off valve 20, and a first pipe 41, a second pipe 42, a third pipe 43, and a fourth pipe 44 that are connected to the body 30, respectively.

[0018] Referring to Figure 2, the on-off valve 20 comprises a thermoelement case 21 containing paraffin wax as a content, a piston 22 that can move in a direction protruding from the thermoelement case due to the expansion of the paraffin wax, a valve body 23 fixed to the thermoelement case 21, and a coil spring 24 (biasing member) that biases the valve body 23 in the direction of protrusion of the piston 22.

[0019] The valve element 23 is pressed against the valve seat 41b of the first pipe 41 by a coil spring 24, closing the water passage connecting the accommodation space 32 and the first pipe 41. The valve seat 41b is formed on the leading edge of the first pipe 41. Note that the valve seat does not necessarily have to be on the leading edge of the first pipe 41. For example, the valve seat may be provided on the inner periphery of the first pipe 41, or the valve seat may be separate from the first pipe 41. The leading end of the piston 22 is inserted into a support portion 101 provided in the first pipe 41. Movement of the piston 22 upward in Figures 2 and 3 is restricted by this support portion 101. The amount of protrusion of the piston 22 changes as the paraffin wax expands and contracts in response to temperature changes in the coolant flowing through the body 30.

[0020] In this embodiment, the piston 22 abuts against the first pipe 41. As the temperature of the coolant rises, the paraffin wax contained therein expands. As the paraffin wax expands, the piston 22 is pushed out of the thermo-element case 21. The tip of the piston 22 abuts against a support portion 101 provided on the first pipe 41, and further upward movement in FIG. 2 is restricted, so the thermo-element case 21 moves and the piston 22 retracts from the thermo-element case 21.

[0021] The valve element 23 moves together with the thermo-element case 21 in a direction away from the first pipe 41 while compressing the coil spring 24, and separates from the valve seat 41b, opening the on-off valve 20. The first pipe 41 opens, and the coolant in the body 30 flows through the first pipe 41 toward the radiator (not shown).

[0022] The body 30 is attached to a coolant outlet of an automobile engine (not shown). The body 30 includes an inlet 31 for taking in coolant, a storage space 32 communicating with the inlet 31, an outlet passage 33 arranged next to the storage space 32, a partition wall 34 separating the storage space 32 from the outlet passage 33, a bypass passage 35 for directing the coolant in the storage space 32 to the outlet passage 33, and a flat mounting surface 36 arranged to surround the inlet 31. The storage space 32 accommodates a portion of the on-off valve 20, specifically, the thermo-element case 21, the valve element 23, and the coil spring 24.

[0023] The first pipe 41 is connected to the upper left side of the body 30 in FIGS. 1 to 3 and can communicate with the storage space 32. The communication between the first pipe 41 and the storage space 32 is allowed or blocked by the on-off valve 20. The gap between the first pipe 41 and the body 30 is sealed to prevent leakage of the coolant. As shown in FIG. 3, when the on-off valve 20 is opened, the first pipe 41 guides the coolant to a radiator (not shown) of the automobile (not shown). The second pipe 42 is connected to the upper right side of the body 30 in FIGS. 1 to 3 and guides the coolant returning from the radiator (not shown) or the like to the outlet passage 33. The gap between the second pipe 42 and the body 30 is sealed to prevent leakage of the coolant.

[0024] 1 to 3, the third pipe 43 is connected to the rear surface of the body 30, communicates with the housing space 32, and extends downward to guide the coolant to other accessories (e.g., a heater core (not shown)). The third pipe 43 is molded integrally with the body 30. The fourth pipe 44 is connected to the lower right side of the body 30 in FIGS. 1 to 3, communicates with the outlet passage 33, and guides the coolant to the engine (not shown) and a water pump (not shown). The gap between the fourth pipe 44 and the body is sealed to prevent coolant leakage.

[0025] The partition wall 34 has a recess 34a that is recessed from the storage space 32 toward the outlet passage 33. The surface of the recess 34a closest to the outlet passage 33, facing the storage space 32, has a first surface 34b that is perpendicular to the mounting surface 36, and this first surface 34b is continuous with the edge of the inlet 31.

[0026] A communication port 35 a of the bypass passage 35 of the accommodation space 32 to the accommodation space 32 is disposed at a position facing the tip edge of the first pipe 41 .

[0027] Here, as the temperature of the coolant rises, the paraffin wax contained therein expands. As the paraffin wax expands, the piston 22 is pushed out of the thermo-element case 21. Because the piston 22 is in contact with the first pipe 41 and is restricted from moving any further, the thermo-element case 21 moves away from the piston 22, causing the piston 22 to retract from the thermo-element case 21. Together with the thermo-element case 21, the valve element 23 compresses the coil spring 24 and moves in a direction away from the first pipe 41, separating from the valve seat 41b, and the on-off valve 20 enters an open state. When the on-off valve 20 opens, the accommodation space 32 and the first pipe 41 communicate with each other, and the coolant in the body 30 flows through the first pipe 41 toward the radiator (not shown).

[0028] As shown in Fig. 3, when the on-off valve 20 opens, the thermo-element case 21 moves together with the valve body 23 against the biasing force of the coil spring 24. At this time, as shown in Fig. 3, the end of the thermo-element case 21 enters the bypass passage 35, and the end of the thermo-element case 21 enters the inlet of the bypass passage 35. As a result, when the opening amount of the on-off valve 20 increases, the communication port 35a of the bypass passage 35 is blocked by the thermo-element case 21, and the flow rate of the coolant passing from the inlet 31 through the bypass passage 35 to the fourth pipe 44 (indicated by the dashed line in Fig. 2) decreases, making it easier for the coolant to flow to the first pipe 41, and the flow rate of the coolant passing from the inlet 31 to the first pipe 41 (indicated by the dashed line in Fig. 3) increases.

[0029] The surface of the recess 34a of the partition wall 34 closest to the outlet passage 33 on the storage space side has a third surface 34c that curves smoothly from the vertical first surface 34b toward the communication port 35a of the bypass passage 35. By forming the curved third surface 34c in this manner, it is possible to prevent the coolant from accumulating at the end of the recess 34a.

[0030] The recessed portion 34a is set so that the minimum flow area X of the outlet passage 33 of the body 30 in the region where the recessed portion 34a is provided, in other words, the region where the partition wall 34 is closer to the outlet passage 33 than in the past, is larger than the minimum flow area Y of the second pipe 42. In other words, the partition wall 34 is positioned closer to the outlet passage 33. As a result, even if the recessed portion 34a is provided, in other words, even if the partition wall 34 is positioned in a direction that narrows the outlet passage 33, it is possible to suppress obstruction of the flow of coolant (indicated by the two-dot chain line in FIG. 3 ) from the radiator toward the engine through the second pipe 42 and the fourth pipe 44.

[0031] 4 , a communication port 43a of the third pipe 43 is opened in the body 30. The third pipe 43 communicates with the accommodation space 32 via the communication port 43a. The communication port 43a of the third pipe 43 is located on the opposite side of the inlet 31 from the thermo-element case 21. In other words, the thermo-element case 21 is disposed between the inlet 31 and the communication port 43a of the third pipe 43.

[0032] The body 30 is provided with a baffle wall 37 that prevents the coolant that has flowed into the recess 34a from the inlet 31 from flowing smoothly into the third pipe 43. The baffle wall 37 extends perpendicular to the first surface 34b of the recess 34a and is parallel to the mounting surface 36. As shown by the two-dot chain line L1 in Fig. 4 , the baffle wall 37 is positioned to coincide with the edge of the communication port 43a of the third pipe 43 that is closest to the mounting surface 36. This allows the baffle wall 37 to have an effect of preventing the coolant from flowing smoothly from the recess 34a into the third pipe 43, while ensuring that the recess 34a is as large as possible, thereby maximizing the effect of the recess 34a in reducing pressure loss to the first pipe 41.

[0033] 5 and 6 , which are enlarged views of FIG. 5 , the body 30 includes a flow straightening surface 38 that guides the coolant from the inlet 31 to the first pipe 41. The flow straightening surface 38 is perpendicular to the mounting surface 36. If the flow straightening surface 38 were tilted downward from right to left in FIGS. 5 and 6 , the pressure loss of the coolant to the first pipe 41 would increase. Furthermore, if the flow straightening surface 38 were tilted upward from right to left in FIGS. 5 and 6 , a complex mold would be required to ensure that the coolant could be easily removed from the mold when molding the body 30, which would increase costs. Therefore, to reduce the pressure loss of the coolant flowing to the first pipe 41 while keeping costs down, it is preferable to make the flow straightening surface 38 perpendicular to the mounting surface 36.

[0034] The first pipe 41 is connected to the body 30 so that an edge 41 a of the first pipe 41 on the inlet 31 side, which serves as a valve seat, is located above the flow straightening surface 38 in Figures 5 and 6. This allows the coolant to flow smoothly through the first pipe 41 without colliding with the inlet 31 side of the first pipe 41.

[0035] In the thermostat 1 of this embodiment, the recess 34a increases the flow rate of coolant around the valve body 23, reducing the pressure loss of coolant into the first pipe 41 when the valve body 23 is open. Furthermore, because the recess 34a is recessed from the accommodation space 22 toward the outlet passage 33, the outer edge of the body 30 remains unchanged from the conventional one, and the flow rate of coolant into the first pipe 41 can be increased compared to the conventional one while keeping the size of the body 30 the same.

[0036] For example, in this embodiment, the extension line of the baffle wall 37, indicated by the dashed-dotted line L1 in Figure 4, is positioned so as to coincide with the edge of the communication port of the third pipe 43 closest to the mounting surface. However, since the baffle wall of the present invention is only required to increase the flow rate through the recess 34a into the first pipe 41 and to impede the smooth flow from the recess 34a into the third pipe 43 to some extent, the baffle wall may be positioned slightly in front of or behind the edge of the communication port 43a of the third pipe 43 closest to the mounting surface 36. This still achieves the advantageous effect of the present invention, in which the recess 34a reduces pressure loss into the first pipe 41 when the valve is opened. The shape, position, and angle of the baffle wall may be adjusted as needed to suit the required flow rate.

[0037] Furthermore, in this embodiment, the third surface 34c is curved, but the third surface 34c of the present invention does not have to be curved. Furthermore, in this embodiment, the minimum flow area X in the region of the outlet passage 33 where the recessed portion 34a is provided, in other words, the region where the partition wall 34 is closer to the outlet passage 33 than in the past, is set to be larger than the minimum flow area Y of the second pipe 42. However, in the thermostat of the present invention, the relationship between the minimum flow area X in the region of the outlet passage 33 where the recessed portion 34a is provided and the minimum flow area Y of the second pipe 42 may be appropriately changed depending on the required flow rate. Furthermore, in this embodiment, the coil spring 24 is used as the biasing member, but the biasing member of the present invention is not limited to a coil spring and may be another elastic member.

[0038] As explained above, the thermostat 1 of this embodiment comprises: an on-off valve 20; a body 30 accommodating the on-off valve 20; and a first pipe 41, a second pipe 42, a third pipe 43, and a fourth pipe 44 connected to the body 30, the first pipe 41 directing coolant to a radiator (not shown), and the second pipe 42 returning coolant from the radiator (not shown); the on-off valve 20 comprises a thermoelement case 21; a piston 22 movable in a protruding direction from the thermoelement case 21 by expansion of a material contained in the thermoelement case 21 (a material that expands and contracts freely in response to changes in the temperature of the coolant; a temperature-sensitive material, such as paraffin wax); a valve body 23 fixed to the thermoelement case 21; and a biasing member (e.g., a coil spring 24) biasing the valve body 23 in the protruding direction of the piston 22; the valve body 23 releasably closes the first pipe 41; The body 30 is provided at the coolant outlet of the engine and comprises an inlet 31 for taking in coolant, a storage space 32 communicating with the inlet 31, an outlet passage 33 arranged alongside the storage space 32 and connected to the second pipe 42 to return coolant from the radiator (not shown), a partition wall 34 separating the storage space 32 from the outlet passage 33, a bypass path 35 for directing the coolant in the storage space 32 to the outlet passage 33, and a flat mounting surface 36 arranged to surround the inlet 31, the partition wall 34 having a recessed portion 34a recessed from the storage space 32 to the outlet passage 33, the surface of the recessed portion 34a closest to the outlet passage 33 on the storage space side having a first surface 34b perpendicular to the mounting surface 36, and the first surface 34b continuing to the edge of the inlet 31.

[0039] According to this embodiment, the recess 34a can increase the cross-sectional area of ​​the coolant flow path around the valve body 23, thereby reducing the pressure loss of the coolant to the first pipe 41 connected to the radiator when the valve body 23 is open. Furthermore, because the recess 34a is recessed toward the outlet passage 33, in other words, the partition wall 34 is closer to the outlet passage 33 than in the past, the pressure loss of the coolant in the radiator can be reduced without increasing the outer circumferential dimensions of the body 30.

[0040] In addition, in this embodiment, the corner 34c of the recess 34a on the bypass passage 35 side has a uniform thickness and is curved so that the flow path cross-sectional area of ​​the outlet passage 33 increases toward the downstream side of the outlet passage 33.

[0041] According to this embodiment, the corners 34c are curved, so that the coolant does not stagnate at the corners 34c of the recess 34a, but can be smoothly guided to the bypass path 35 and flow without stagnation. The corners 34c of the recess 34a on the bypass path 35 side may be sharp or may be chamfered with an inclined portion.

[0042] In this embodiment, the minimum flow path area X of the outlet passage 33 of the body 30 in the region where the recessed portion 34 a is provided is set to be larger than the minimum flow path area Y of the second pipe 42 .

[0043] According to this embodiment, by providing the recess 34a, the minimum flow area X of the outlet passage 33 in the region where the recess 34a is provided is smaller than that of a conventional thermostat, but is set larger than the minimum flow area Y of the second pipe 42. Therefore, even if the partition wall 34 is moved in a direction that narrows the outlet passage 33 by the recess 34a, the flow of coolant indicated by the two-dot chain line in Figure 3 is not impeded and pressure loss does not increase. Note that, as long as the required flow rate can be ensured, the relationship between the minimum flow area X of the outlet passage 33 in the region where the recess 34a is provided and the minimum flow area Y of the second pipe 42 may be changed as appropriate.

[0044] In addition, in this embodiment, the body 30 is provided with a baffle wall 37, which extends perpendicular to the first surface 34b of the recess portion 34a and is composed of a surface parallel to the mounting surface 36, and the baffle wall 37 is positioned to coincide with the edge of the communication port 43a of the third piping 43 closest to the mounting surface 36.

[0045] According to this configuration, the baffle wall 37 can prevent the coolant that has entered the recess 34a from smoothly flowing into the third pipe 43, thereby reducing the flow rate into the third pipe 43 and ensuring the flow rate into the first pipe 41. As a result, the baffle wall 37 has the effect of inhibiting the smooth flow of coolant from the recess 34a into the third pipe 43, while ensuring the recess 34a is as large as possible, thereby maximizing the effect of the recess 34a in reducing pressure loss into the first pipe 41. Note that depending on the position of the communication port 43a of the third pipe 43, the baffle wall 37 may be omitted, and the position, area, shape, angle, and attitude of the baffle wall 37 may be changed as appropriate as long as the required flow rates can be ensured in each of the first pipe 41 and the third pipe 43.

[0046] In addition, in this embodiment, the body 30 has a straightening surface 38 located between the inlet 31 and the tip edge of the first pipe 41, and the edge 41a of the tip edge of the first pipe 41 on the inlet 31 side is located closer to the outer end of the first pipe than the extension plane of the straightening surface 38.

[0047] With this configuration, the coolant that enters through the inlet 31 and flows through the flow straightening surface 38 can flow to the first pipe 41 without being obstructed by the edge 41 a of the tip edge of the first pipe 41 on the inlet 31 side. Note that the position of the tip of the first pipe 41 can be changed as appropriate as long as the flow rate of the first pipe 41 can be ensured.

[0048] Although specific examples of the embodiments of the present invention have been described above, the thermostat of the present invention is not limited to the above-described embodiments and can be modified as appropriate within the scope of the claims.

[0049] REFERENCE SIGNS LIST 1 thermostat 20 on-off valve 21 thermoelement case 22 piston 23 valve body 24 coil spring 30 body 31 inlet 32 ​​accommodation space 33 outlet passage 34 partition wall 34a recessed portion 34b first surface 34c third surface 35 bypass path 35a communication port 36 mounting surface 37 baffle wall 37a second surface 38 flow straightening surface 41 first pipe 41a edge on inlet side 41b valve seat 42 second pipe 43 third pipe 43a communication port 44 fourth pipe 101 support portion X minimum flow path area of ​​outlet passage Y minimum flow path area of ​​second pipe

Claims

1. A thermostat comprising a shut-off valve, a body that houses the shut-off valve, a first pipe, a second pipe, a third pipe, and a fourth pipe, each connected to the body, wherein the first pipe guides a coolant to a radiator, and the second pipe is a thermostat through which the coolant from the radiator returns. The shut-off valve includes a thermo-element case, a piston movable in a protruding direction from the thermo-element case due to expansion of the contents therein, a valve body fixed to the thermo-element case, and a biasing member that biases the valve body in the protruding direction of the piston. The valve body releasably closes the first pipe. The body is provided at a coolant outlet of an engine and includes an inlet through which the coolant is taken in, a housing space communicating with the inlet, an outlet passage arranged beside the housing space to which the second pipe is connected and through which the coolant from the radiator returns, a partition wall that partitions the housing space and the outlet passage, a bypass passage that guides the coolant in the housing space to the outlet passage, and a flat mounting surface arranged to surround the inlet. The partition wall has a recessed portion that is recessed from the housing space to the outlet passage. The surface on the housing space side of the portion of the recessed portion closest to the outlet passage has a first surface perpendicular to the mounting surface. The first surface is continuous with the edge of the inlet.

2. The thermostat according to claim 1, wherein the corner portion of the recessed portion on the bypass passage side has a uniform wall thickness and is curved such that the flow passage cross-sectional area of the outlet passage increases as it goes downstream of the outlet passage.

3. The thermostat according to claim 1 or claim 2, wherein the minimum flow passage area in the region of the body where the recessed portion of the outlet passage is provided is set to be larger than the minimum flow passage area of the second pipe.

4. The thermostat according to claim 1 or claim 2, wherein the body includes a baffle wall. The baffle wall extends perpendicular to the first surface of the recessed portion and has a second surface parallel to the mounting surface. The second surface of the baffle wall is arranged to coincide with the edge of the communication port of the third pipe closest to the mounting surface.

5. The thermostat according to claim 1, wherein one end of the first pipe is inserted into the body. When, looking from the first pipe, the direction toward the one end of the first pipe is defined as the first direction and the direction outward from the body on the side opposite to the one end of the first pipe is defined as the second direction, the body includes a rectifying surface located between the inlet and the connection port of the first pipe. When a virtual plane obtained by extending the rectifying surface is defined as an extended plane, the one end of the first pipe is positioned so as to be away from the extended plane in the second direction.

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