JP7417446B2 - control valve - Google Patents

Description

The present invention relates to a control valve used for switching the flow path of vehicle cooling water.

In a cooling system that uses cooling water to cool the engine, in addition to the radiator flow path that circulates between the radiator and the engine, there is also a bypass flow path that bypasses the radiator and a warm-up flow path that passes through the oil warmer. Sometimes. In this type of cooling system, a control valve is interposed at a branch part of a flow path, and the flow path is appropriately switched by the control valve. As a control valve, one in which a valve body is rotatably arranged in a casing and an arbitrary flow path is opened or closed depending on the rotational position of the valve body is known (see, for example, Patent Document 1).

In the control valve described in Patent Document 1, the casing is provided with an inlet through which a liquid such as cooling water flows, and a plurality of outlet ports through which the inflowing liquid flows out. The valve body is rotatably arranged inside the casing. The valve body has a substantially cylindrical peripheral wall portion, and a valve hole is formed in the peripheral wall portion to communicate the inside and outside of the peripheral wall portion. A seal cylinder member is attached to the outlet of the casing. An annular valve sliding surface that slides on the outer peripheral surface of the peripheral wall of the valve body is formed on the end face of the seal cylinder member on the side opposite to the outer peripheral surface of the valve body (the peripheral wall of the peripheral wall). The valve sliding surface of the seal cylinder member slides on the outer circumferential surface of the peripheral wall portion at a position where it overlaps the rotation path of the corresponding valve hole of the valve body.

The valve body of the control valve allows liquid to flow from the inner region of the valve body to the corresponding outlet when the axial end of the seal cylinder member is in a position communicating with the corresponding valve hole, and the seal When the axial end of the cylindrical member is in a position where it does not communicate with the corresponding valve hole, outflow of liquid from the inner region of the valve body to the corresponding outlet is blocked. Note that the rotational position of the valve body is controlled by an actuator such as an electric motor.
Further, the valve hole formed in the peripheral wall portion of the valve body is formed in a perfect circular shape or a long hole shape that is elongated in the circumferential direction. A perfectly circular valve hole is used to flow liquid to the outlet at a specific rotational position of the valve body, and a circumferentially long valve hole is used to flow liquid to the outlet over a wide range of rotation of the valve body. An elongated valve hole is used.

JP2018-71621A

In the control valve described in Patent Document 1, the inner diameter of the perfectly circular valve hole is approximately the same as or slightly larger than the inner diameter of the communication hole of the seal cylinder member. For this reason, when forming a plurality of valve holes spaced apart in the circumferential direction on the upper part of the peripheral wall of the valve body, the circumferential length of the valve body must be reduced to a certain degree or more in order to suppress a decrease in the rigidity of the valve body. I can't. In the above control valve, this has been a bottleneck in reducing the outer diameter of the peripheral wall portion of the valve body. In addition, if the inner diameter of the valve hole is made smaller in order to reduce the outer diameter of the peripheral wall of the valve body, the pressure loss of the liquid at the valve hole will increase, and the flow rate of the liquid flowing out from the outlet will decrease. It ends up.

Therefore, the present invention provides a control valve that can reduce the outer diameter of the peripheral wall of the valve body while suppressing a decrease in the flow rate of liquid flowing out from the outlet, thereby reducing the size of the entire device. This is what we are trying to provide.

A control valve according to one embodiment of the present invention includes a casing having an inlet through which liquid flows in from the outside and an outlet through which the liquid that has flowed into the inside flows out to the outside; a valve body having a peripheral wall portion formed with a valve hole that communicates with the valve body, one end in the axial direction communicates with the outlet, and the other end in the axial direction has a rotation path of the valve hole of the valve body. and a seal cylindrical member provided with an annular valve sliding contact surface that slidably contacts the outer peripheral surface of the peripheral wall portion at a position where at least a portion thereof overlaps, the seal cylindrical member comprising: a first cylindrical portion located on the one end side and communicating with the outlet; and a first cylindrical portion located on the other end side, whose axial end surface forms the valve sliding surface and whose inner diameter a second cylindrical portion larger than the inner diameter of the first cylindrical portion; The circumferential width W1 of the valve hole is set to satisfy equation (1).
R1≦W1<W2…(1)
R1: Inner diameter of the first cylindrical portion W2: Axial width of the valve hole

In this control valve, the valve hole of the valve body has an oval shape in which the width in the circumferential direction is narrower than the width in the axial direction, so the circumferential length of the peripheral wall can be shortened while suppressing a decrease in the rigidity of the peripheral wall of the valve body. can do. Therefore, the outer diameter of the peripheral wall portion of the valve body can be made small. In addition, in this control valve, since the circumferential width of the valve hole is set to be larger than the inner diameter of the first cylindrical portion of the seal cylindrical member, the pressure loss of the liquid flowing out from the outlet is reduced to the first cylindrical portion. is affected by the inner diameter of the valve hole, and is not affected by the circumferential width of the valve hole. Therefore, even if the circumferential width of the valve hole is narrowed, as long as the circumferential width is within the above range, the pressure loss of the liquid will not increase.
In addition, in this control valve, the valve hole of the valve body has an oval shape in which the width in the circumferential direction is narrower than the width in the axial direction. It is possible to increase the amount of change in the communication area between the valve hole and the seal cylinder member with respect to the moving speed in the direction. Therefore, with this control valve, a desired outflow flow rate can be quickly obtained by adjusting the rotation of the valve body.

It is desirable that the axial width W2 of the valve hole is set to satisfy equation (2).
W2<R2...(2)
R2: Outer diameter of the second cylindrical part

In this case, since the axial width of the valve hole is set to be narrower than the outer diameter of the second cylindrical portion, when the valve body is rotated to the position where the flow rate of liquid from the outlet is maximum. In addition, the valve sliding surface of the second cylindrical portion stably contacts the axially outer edge of the shaft hole of the valve body. Therefore, the state of the seal cylinder member can be stabilized when the valve body is rotated to a position where the flow rate of liquid from the outlet is maximized.
Further, when the second cylindrical portion of the seal cylindrical member communicates with the inside of the peripheral wall portion of the valve body through the valve hole, liquid on the outer peripheral side of the peripheral wall portion becomes difficult to flow into the second cylindrical portion through the valve hole. Therefore, when this configuration is adopted, it is possible to suppress unnecessary pressure fluctuations from occurring in the circumferential area of the seal cylinder member that is in contact with the circumferential wall portion of the valve body.

It is desirable that the circumferential width W1 of the valve hole is set to satisfy equation (3).
W1<R3...(3)
R3: Inner diameter of the second cylinder part

In this case, since the circumferential width of the valve hole is set to be narrower than the inner diameter of the second cylindrical portion, when the valve body is rotated to the position where the flow rate of liquid from the outlet is maximum, , the valve sliding contact surface of the second cylindrical portion stably contacts the circumferentially outer edge of the shaft hole of the valve body. Therefore, the state of the seal cylinder member can be stabilized when the valve body is rotated to a position where the flow rate of liquid from the outlet is maximized.

In the seal cylinder member, the outer diameter of the first cylinder part is larger than the outer diameter of the second cylinder part, and there is a gap between the outer peripheral surface of the first cylinder part and the outer peripheral surface of the second cylinder part. is provided with a step surface, and the step surface constitutes a pressure receiving surface for urging the seal cylinder member toward the valve body in response to the pressure of the liquid inside the casing, and the step surface constitutes a pressure receiving surface for urging the seal cylinder member toward the valve body side. The area S1 of the pressure receiving surface and the area S2 of the valve sliding surface of the seal cylinder member may be set to satisfy equations (4) and (5).
S1<S2≦S1/k...(4)
α≦k<1 (5)
k: Pressure reduction constant of liquid flowing through the minute gap between the valve sliding surface and the valve body.
α: Lower limit value of the pressure reduction constant determined by the physical properties of the liquid.

With the above configuration, the area S1 of the biasing pressure receiving surface of the seal cylinder member becomes an area larger than the value obtained by multiplying the area S2 of the valve sliding contact surface of the seal cylinder member by the pressure reduction constant k. As a result, when the pressure of the liquid in the casing acts on the urging pressure receiving surface and the outer peripheral area of the valve sliding contact surface, the valve body is caused by the liquid pressure acting on the seal cylinder member through the urging pressure receiving surface. The pressing force in this direction is greater than the lifting force from the valve body that acts on the seal cylinder member when liquid leaks from the minute gap between the valve sliding surface and the valve body. Therefore, the valve sliding surface of the seal cylinder member can be maintained in contact with the outer surface of the valve body.
In addition, since the area S1 of the urging pressure receiving surface of the seal cylinder member is smaller than the area S2 of the valve sliding surface, even if the pressure of the liquid in the casing increases, the seal cylinder member presses against the valve body with excessive force. be restrained from being exposed.
In this configuration, the area of the valve sliding surface is larger than the area of the biasing pressure receiving surface within the range where the pressing force in the direction of the valve body by the liquid acting on the seal cylinder member is not less than the lifting force acting on the seal cylinder member. It is set large. Therefore, when this configuration is adopted, it is possible to ensure good sealing performance while suppressing pressing of the seal cylinder member against the valve body with excessive force.

In the above-mentioned control valve, the valve hole of the valve body has an oval shape with a circumferential width narrower than an axial width, and the circumferential width of the valve hole is set to be equal to or larger than the inner diameter of the first cylindrical portion of the seal cylindrical member. Therefore, the outer diameter of the peripheral wall portion of the valve body can be reduced while suppressing a decrease in the flow rate of the liquid flowing out from the outlet. Therefore, when the above-mentioned control valve is employed, it is possible to reduce the size of the entire device while suppressing a decrease in the flow rate of liquid outflow.

FIG. 1 is a block diagram of a cooling system according to an embodiment. FIG. 2 is a perspective view of a control valve according to an embodiment. Exploded perspective view of the control valve of the embodiment FIG. 3 is a sectional view taken along the line IV-IV in FIG. 2 of the control valve of the embodiment. FIG. 5 is a sectional view taken along line VV in FIG. 4 of the control valve of the embodiment. FIG. 6 is an enlarged view of the VI section in FIG. 5. FIG. 3 is a vertical cross-sectional view of the seal cylinder member of the embodiment. FIG. 3 is a partially developed view of the peripheral wall of the valve body of the embodiment.

Next, embodiments of the present invention will be described based on the drawings. In the following description, a case will be described in which the control valve of this embodiment is employed in a cooling system that cools an engine using a coolant.

[Cooling system]
FIG. 1 is a block diagram of a cooling system 1. FIG.
As shown in FIG. 1, a cooling system 1 is mounted on a vehicle that includes at least an engine as a vehicle drive source. Note that the vehicle may be a hybrid vehicle, a plug-in hybrid vehicle, or the like in addition to a vehicle having only an engine.

The cooling system 1 includes an engine 2 (ENG), a water pump 3 (W/P), a radiator 4 (RAD), a heater core 6 (HTR), an EGR cooler 7 (EGR), and a control valve 8 (EWV) in various flow paths 10. .about.14 are connected to each other.
The water pump 3, the engine 2, and the control valve 8 are connected in order from upstream to downstream on the main flow path 10. In the main flow path 10, the coolant (liquid) passes through the engine 2 and the control valve 8 in sequence by the operation of the water pump 3.

A radiator flow path 11, a bypass flow path 12, an air conditioning flow path 13, and an EGR flow path 14 are connected to the main flow path 10, respectively. These radiator flow path 11 , bypass flow path 12 , air conditioning flow path 13 , and EGR flow path 14 connect the upstream portion of the water pump 3 and the control valve 8 in the main flow path 10 .

A radiator 4 is connected to the radiator flow path 11 . In the radiator flow path 11, heat exchange between the cooling liquid and the outside air is performed in the radiator 4. The bypass flow path 12 returns the coolant that has passed through the control valve 8 to the upstream portion of the water pump 3, bypassing the radiator 4 (radiator flow path 11).

A heater core 6 is connected to the air conditioning flow path 13 . The heater core 6 is provided, for example, in a duct (not shown) of an air conditioner. In the air conditioning flow path 13, heat exchange is performed in the heater core 6 between the coolant and the conditioned air flowing through the duct.

An EGR cooler 7 is connected to the EGR flow path 14. In the EGR flow path 14, heat exchange is performed between the cooling liquid and the EGR gas in the EGR cooler 7.

In the cooling system 1 described above, the coolant that has passed through the engine 2 in the main flow path 10 flows into the control valve 8 and is then selectively distributed to the various flow paths 11 to 13 by the operation of the control valve 8.

[Control valve]
2 is a perspective view of the control valve 8, and FIG. 3 is an exploded perspective view of the control valve 8. 4 is a cross-sectional view of the control valve 8 taken along the line IV--IV in FIG. 2, and FIG. 5 is a cross-sectional view of the control valve 8 taken along the line V-V in FIG. 4.
As shown in these figures, the control valve 8 mainly includes a casing 21, a valve body 22, and a drive unit 23.

[casing]
The casing 21 includes a bottomed cylindrical casing body 25 and an end cover 26 attached to the end of the casing body 25 on the opening side. A valve body 22 is rotatably housed inside the casing 21 . The axis of the casing 21 that coincides with the rotation center axis of the valve body 22 is referred to as the axis O1 of the casing 21. Furthermore, in the following description, the direction along the axis O1 of the casing 21 is simply referred to as the case axis direction. In addition, in the case axial direction, the direction toward the bottom wall 32 of the casing body 25 with respect to the case peripheral wall 31 of the casing body 25 is referred to as one end side in the case axial direction, and the end side with respect to the case peripheral wall 31 of the casing body 25 The direction toward the cover 26 is referred to as the other end in the axial direction of the case. Furthermore, the direction perpendicular to the axis O1 of the casing 21 is referred to as the case radial direction.

The casing body 25 is made of a resin material and has a substantially rectangular outer surface shape. A plurality of mounting pieces 33 extend from the other end of the case peripheral wall 31 in the case axial direction. The control valve 8 is fixed to an engine block (not shown) or the like via a mounting piece 33.

The end cover 26 of the casing 21 has a boss portion 26c located at the axis of the annular frame 26a. The boss portion 26c is supported by the frame frame 26a by a plurality of spoke portions 26b. A bottomed cylindrical sliding bearing 16 is attached to the boss portion 26c. An opening portion of the end cover 26 surrounded by the frame frame 26 a , the boss portion 26 c , and the adjacent spoke portions 26 b serves as an inlet 17 through which the cooling liquid flows into the inside of the casing 21 . The inlet 17 is connected to the main flow path 10 (see FIG. 1) of the cooling system 1 on the downstream side of the engine 2. The end cover 26 is made of a resin material like the casing body 25.

A radiator port 41 (see FIG. 4) that bulges outward in the radial direction of the case is formed in a wall forming one surface of the case peripheral wall 31. In the radiator port 41, a fail opening (not shown) and a radiator outlet 60 (outlet) are formed side by side in a direction perpendicular to the case axis direction. The fail opening and radiator outlet 60 are formed through the radiator port 41. Further, the fail opening and the radiator outlet 60 are formed at a position biased toward the other end in the case axial direction of the wall forming one surface of the case peripheral wall 31.

A radiator joint 42 is connected to the open end surface of the radiator port 41. The radiator joint 42 connects the radiator outlet 60 and the upstream end of the radiator flow path 11 (see FIG. 1).
Furthermore, a sealing mechanism 36 is provided at the radiator outlet 60. The seal mechanism 36 includes a seal cylinder member 37, a biasing member 38, and seal members 39 and 40. One axial end of the seal cylinder member 37 communicates with the radiator outlet 60, and the other axial end is opened and closed by a valve body 22, which will be described later. The seal mechanism 36 will be described in detail later.

A thermostat 61 is arranged in the fail opening. The thermostat 61 opens and closes the fail opening depending on the temperature of the coolant flowing inside the casing 21. The fail opening communicates with the radiator joint 42 (radiator flow path 11). The thermostat 61 opens the fail opening to cause the coolant in the casing 21 to flow out into the radiator flow path 11 when the temperature of the coolant flowing in the casing 21 becomes higher than a specified temperature.

An EGR port 62 is formed adjacent to the housing portion of the thermostat 61 near one end of the case peripheral wall 31 in the case axial direction. The EGR port 62 is formed in the case peripheral wall 31 so as to bulge outward in the case radial direction. An EGR outlet 63 is formed in the EGR port 62 and communicates with a portion upstream of the thermostat 61 in the housing portion of the thermostat 61 . The EGR joint 52 is connected to the open end surface of the EGR port 62. The EGR joint 52 connects the EGR outlet 63 and the upstream end of the EGR flow path 14 (see FIG. 1).

A bypass port 64 that bulges outward in the radial direction of the case is formed on the wall of the case peripheral wall 31 on the side opposite to the wall where the radiator port 41 is formed. A bypass outlet 65 (outlet) is formed in the bypass port 64 and passes through the bypass port 64 in the case radial direction. The bypass outlet 65 is formed at a position facing the radiator outlet 60 with the axis O1 of the casing 21 interposed therebetween. Further, the bypass outlet 65 is formed at a position biased toward the other end of the case peripheral wall 31 in the case axial direction, similarly to the radiator outlet 60. A bypass joint 66 is connected to the open end surface of the bypass port 64. The bypass joint 66 connects the bypass outlet 65 and the upstream end of the bypass flow path 12 (see FIG. 1). The bypass outlet 65 is provided with a sealing mechanism 36 similar to that provided at the radiator outlet 60. The seal cylinder member 37 of the seal mechanism 36 has one end in the axial direction communicating with the bypass outlet 65, and the other end in the axial direction is opened and closed by the valve body 22.

An air conditioning port 67 (see FIGS. 2 and 3) that bulges outward in the radial direction of the case is formed in a wall of the case peripheral wall 31 adjacent to one side of the wall where the radiator port 41 is formed. . The air conditioning port 67 is formed with an air conditioning outlet 68 that passes through the air conditioning port 67 in the case radial direction. An air conditioning joint 69 is connected to the open end surface of the air conditioning port 67. The air conditioning joint 69 connects the air conditioning outlet 68 and the upstream end of the air conditioning flow path 13 (see FIG. 1). The air conditioning outlet 68 is provided with a sealing mechanism 36 similar to that provided at the radiator outlet 60 and the bypass outlet 65. The seal cylinder member 37 of the seal mechanism 36 has one end in the axial direction communicating with the air conditioning outlet 68, and the other end in the axial direction is opened and closed by the valve body 22.

[Drive unit]
The drive unit 23 is attached to the bottom wall portion 32 of the casing body 25. As shown in FIG. 4, the bottom wall portion 32 includes a bottom wall main body 32a that closes an end surface of the case peripheral wall 31 on one end side in the case axial direction, and a bottom wall main body 32a that extends from the outer peripheral edge of the bottom wall main body 32a to one end side in the case axial direction. It has a protruding surrounding wall 32b. A portion of the drive unit 23 is housed inside the surrounding wall 32b, and in this state is fixed to the bottom wall portion 32 by bolting or the like.

The drive unit 23 includes a unit main body 23A that includes a motor, a speed reduction mechanism, a control board, etc., and a unit case 23B that accommodates the unit main body 23A. The output shaft 23Aa of the unit main body 23A penetrates the unit case 23B and projects to the outside. A separate drive shaft 27 is integrally connected to the output shaft 23Aa. The drive shaft 27 includes a first shaft 27A made of resin and a second shaft 27B made of metal, which are coaxially connected. The drive shaft 27 passes through a shaft hole 28 formed in the bottom wall main body 32a of the casing 21, and is connected to the shaft center of the valve body 22, which will be described later. The drive shaft 27 is arranged coaxially with the axis O1 of the casing 21.

The bottom wall body 32a of the casing 21 has a wall thickness on the side facing into the case peripheral wall 31 that increases from the peripheral edge toward the center region (the region where the shaft hole 28 is formed). The shaft hole 28 is formed to penetrate the thickest part of the bottom wall main body 32a in the case axial direction. A cylindrical sliding bearing 29 is held inside the shaft hole 28 to slidably support the outer peripheral surface of the drive shaft 27 (first shaft 27A). Further, an enlarged diameter groove 30 having an inner diameter larger than the inner peripheral surface of other parts of the shaft hole 28 is formed at the end edge of the shaft hole 28 on the valve body 22 side. Inside the enlarged diameter groove 30, there is a seal that is slidably in close contact with the outer circumferential surface of the drive shaft 27 (second shaft 27B) to prevent leakage of the coolant from the inside of the casing body 25 to the drive unit 23 side. A ring 35 is attached. Further, the other end side portion of the second shaft 27B of the drive shaft 27 in the case axial direction is rotatably supported by the boss portion 26c of the end cover 26 via the sliding bearing 16.

[Valve body]
The valve body 22 is rotatably arranged inside the casing 21. The valve body 22 includes a cylindrical peripheral wall 44, a connecting flange 45 extending radially inward from one end of the peripheral wall 44 in the axial direction of the case, and a radially inner end of the connecting flange 45. A substantially cylindrical connecting cylinder part 46 is provided. These peripheral wall portion 44, connection flange portion 45, and connection cylinder portion 46 are integrally formed of a resin material. The connecting cylinder portion 46 is integrally connected to the drive shaft 27 (second shaft 27B). The peripheral wall portion 44 is formed with valve holes 47, 47A, and 47B that can communicate with each of the above-mentioned outlets (bypass outlet 65, radiator outlet 60, and air conditioning outlet 68). Each valve hole 47, 47A, 47B penetrates the peripheral wall portion 44 in the case radial direction.

A plurality of (for example, two) valve holes 47 that can communicate with the bypass outlet 65 are formed in a region of the peripheral wall portion 44 on the other end side in the case axial direction. A plurality (for example, two) of valve holes 47A that can communicate with the radiator outlet 60 are formed in a region of the peripheral wall portion 44 on the other end side in the case axial direction. The valve hole 47 that can communicate with the bypass outlet 65 and the valve hole 47A that can communicate with the radiator outlet 60 are formed in substantially the same axial region on the circumference of the peripheral wall portion 44 . The shape and size of the valve holes 47, 47A will be detailed later.

Only one valve hole 47B that can communicate with the air conditioning outlet 68 is formed in a region of the peripheral wall portion 44 on one end side in the case axial direction. The valve hole 47B is formed in a long hole shape along the circumferential direction of the peripheral wall portion 44. This valve hole 47B allows communication between the inner space of the peripheral wall portion 44 of the valve body 22 and the air conditioning outlet 68 when the valve body 22 is within a predetermined rotation range.

[Seal mechanism]
Next, the structure of the seal mechanism 36 provided at each outlet (bypass outlet 65, radiator outlet 60, air conditioning outlet 68) and its surrounding area will be described. Note that the seal mechanisms 36 disposed at each outlet have the same basic structure, so the seal mechanism 36 of the bypass outlet 65 and the structure of its surrounding area will be explained in detail below, and the radiator flow will be explained in detail. A description of the structure of the sealing mechanism 36 of the outlet 60 and the air conditioning outlet 68 and its surrounding parts will be omitted.

FIG. 6 is an enlarged view of the VI section of FIG. In the following description, the direction along the axis O2 of the bypass outlet 65 may be referred to as the port axial direction. In this case, in the port axial direction, the side facing the axis O1 with respect to the bypass port 64 is referred to as the inside, and the side facing away from the axis O1 with respect to the bypass port 64 is referred to as the outside. Further, the direction perpendicular to the axis O2 may be referred to as the port radial direction, and the direction around the axis O2 may be referred to as the port circumferential direction.
As shown in FIG. 6, the bypass outlet 65 formed in the bypass port 64 includes a small diameter hole 65a adjacent to the inner surface of the casing 21, and a medium diameter hole 65b connected to the outside of the small diameter hole 65a in the port axial direction. , and a large-diameter hole 65c connected to the outside of the medium-diameter hole 65b in the port axial direction.

The bypass joint 66 includes a joint cylindrical portion 53 disposed coaxially with the axis O2, and a joint flange portion 54 projecting outward from the joint cylindrical portion 53 in the port radial direction. The joint flange portion 54 is overlapped with the end surface of the bypass port 64 in the bulging direction, and is fixed to the bypass port 64 by fastening bolts or the like. The joint cylindrical portion 53 also includes a large diameter portion 53a that fits into the large diameter hole 65c of the bypass outlet 65, a small diameter portion 53b that fits into the medium diameter hole 65b of the bypass outlet 65, and a small diameter portion 53b that fits into the large diameter hole 65c of the bypass outlet 65. 65, and a medium diameter portion 53c that forms an annular seal housing portion 58 with the large diameter hole 65c.
Further, an enlarged diameter groove 55 is formed in the inner circumferential surface of the joint cylinder portion 53 and continues to the inner end in the port axial direction. A stepped portion 55a is provided at the outer end of the enlarged diameter groove 55 in the port axial direction.

A sealing mechanism 36 is arranged in a portion of the bypass port 64 surrounded by the bypass outlet 65 and the bypass joint 66. The seal mechanism 36 includes a seal cylinder member 37, a biasing member 38, and seal members 39 and 40. A portion of the seal cylinder member 37 is inserted into the small diameter hole 65a of the bypass outlet 65.

FIG. 7 is a longitudinal sectional view of the seal cylinder member 37.
As shown in FIGS. 5 to 7, the seal cylinder member 37 has a peripheral wall that extends coaxially with the axis O2. The peripheral wall of the seal cylindrical member 37 is formed into a multistage cylindrical shape whose outer diameter decreases in steps toward the outside in the port axial direction. Specifically, the peripheral wall of the seal cylinder member 37 is located on the outside in the port axial direction (one end side in the axial direction) and communicates with the first cylinder part 56 that communicates with the downstream side of the bypass outlet 65, and the peripheral wall in the port axial direction. A second cylindrical portion 57 is located inside (on the other end side in the axial direction) and has a larger inner diameter and outer diameter than the first cylindrical portion 56. The inner peripheral surfaces of the first cylindrical portion 56 and the second cylindrical portion 57 constitute a seal opening 90 that communicates the outer end (one end) and the inner end (other end) of the seal cylindrical member 37 in the port axial direction. ing.

The seal cylinder member 37 has a large-diameter second cylinder portion 57 slidably inserted into the inner peripheral surface of the small-diameter hole 65a of the bypass outlet 65. The inner end surface of the second cylindrical portion 57 in the port axial direction constitutes an annular valve sliding surface 59 that slidably contacts the outer peripheral surface of the peripheral wall portion 44 of the valve body 22 . In this embodiment, the valve sliding contact surface 59 is a curved surface formed to follow the radius of curvature of the outer peripheral surface of the peripheral wall portion 44 .

The outer circumferential surface of the first cylindrical portion 56 is continuous with the outer circumferential surface of the second cylindrical portion 57 via a stepped surface 49 . Between the outer circumferential surface of the first cylindrical portion 56 of the seal cylindrical member 37 and the inner circumferential surface of the medium diameter hole 65b of the bypass outlet 65, there is a stepped surface 49 of the seal cylindrical member 37 and a small diameter portion 53b of the bypass joint 66. A gap Q1 is formed between the end faces. An annular sealing member 39 such as an X packing or a Y packing is interposed in this gap Q1. The seal member 39 is slidably in close contact with the outer circumferential surface of the first cylindrical portion 56 of the seal cylindrical member 37 and the inner circumferential surface of the medium diameter hole 65b of the bypass outlet 65.
In addition, the inside of the casing 21 is provided through the gap between the small diameter hole 65a of the bypass outlet 65 and the second cylindrical portion 57 of the seal cylindrical member 37 into the space inside the port axial direction across the seal member 39 in the gap Q1. A hydraulic pressure of the coolant is introduced. The stepped surface 49 is formed in a direction opposite to the valve sliding contact surface 59 of the seal cylinder member 37 in the port axial direction. The stepped surface 49 constitutes a pressure receiving surface that receives the hydraulic pressure of the cooling fluid in the casing 21 and is pressed inward in the port axial direction.
Further, an annular sealing member 40 such as an O-ring is interposed between the large diameter hole 65c of the bypass outlet 65 and the medium diameter portion 53c of the bypass joint 66 for liquid-tightly sealing the space between the two. There is.

The biasing member 38 is interposed between the axial end surface of the first cylindrical portion 56 of the seal cylindrical member 37 and the stepped portion 55a of the bypass joint 66. The biasing member 38 is composed of, for example, a wave spring. The biasing member 38 biases the seal cylinder member 37 inward in the port axial direction (toward the peripheral wall portion 44 of the valve body 22).

Here, in the seal cylinder member 37, the area S1 of the stepped surface 49 and the area S2 of the valve sliding contact surface 59 are set so as to satisfy the following equations (4) and (5).
S1<S2≦S1/k...(4)
α≦k<1 (5)
k: Pressure reduction constant of the coolant flowing through the minute gap between the valve sliding surface 59 and the peripheral wall 44 of the valve body 22 α: Lower limit value of the pressure reduction constant determined by the physical properties of the coolant Note that the area of the stepped surface 49 The area S2 between S1 and the valve sliding contact surface 59 means the area when projected in the port axial direction.

α in equation (5) is a standard value of the pressure reduction constant determined by the type of coolant, the usage environment (for example, temperature), and the like. For example, under normal usage conditions, α=1/2 in the case of water. When the physical properties of the cooling water used change, α changes to 1/3, etc.
Further, the pressure reduction constant k in equation (5) is a standard value of the pressure reduction constant when the valve sliding surface 59 is in uniform contact with the peripheral wall portion 44 from the outer edge to the inner edge in the port radial direction. α (for example, 1/2). However, due to manufacturing errors, assembly errors, etc. of the seal cylinder member 37, the gap between the outer circumferential portion of the valve sliding contact surface 59 and the peripheral wall portion 44 increases slightly relative to the inner circumferential portion of the valve sliding contact surface 59. Sometimes. In this case, the pressure reduction constant k in equation (5) gradually approaches k=1.

In this embodiment, on the premise that there is a minute gap between the valve sliding contact surface 59 of the seal cylinder member 37 and the outer circumferential surface of the peripheral wall portion 44 to allow sliding, there is a gap between the stepped surface 49 and the valve sliding surface. The relationship between the areas S1 and S2 of the contact surface 59 is determined by equations (4) and (5).
That is, the pressure of the coolant in the casing 21 acts directly on the step surface 49 of the seal cylinder member 37 as described above. On the other hand, the pressure of the coolant in the casing 21 does not directly act on the valve sliding surface 59. Specifically, the pressure of the coolant decreases when the coolant flows through the minute gap between the valve sliding surface 59 and the peripheral wall 44 from the outer edge to the inner edge in the radial direction of the port. It acts while accompanying. At this time, the pressure of the coolant gradually decreases toward the inner side in the port radial direction, while attempting to push the seal cylinder member 37 outward in the port axial direction.

As a result, the force obtained by multiplying the area S1 of the stepped surface 49 by the pressure P inside the casing 21 acts on the stepped surface 49 of the seal cylinder member 37 as is. On the other hand, a force obtained by multiplying the area S2 of the valve sliding surface 59 by the pressure P inside the casing 21 and the pressure reduction constant k acts on the valve sliding surface 59 of the seal cylinder member 37.

In the control valve 8 of this embodiment, the areas S1 and S2 are set so that k×S2≦S1 holds, as is clear from equation (4). Therefore, the relationship P×k×S2≦P×S1 also holds true.
Therefore, the force F1 (F1=P×S1) in the pushing direction acting on the step surface 49 of the seal cylinder member 37 is equal to the force F2 (F2=P×S1) in the lifting direction acting on the valve sliding contact surface 59 of the seal cylinder member 37. k×S2) or more. Therefore, in the control valve 8 of this embodiment, the seal between the seal cylinder member 37 and the peripheral wall portion 44 can be sealed only by the pressure relationship of the coolant in the casing 21.

On the other hand, in this embodiment, as described above, the area S1 of the stepped surface 49 of the seal cylinder member 37 is smaller than the area S2 of the valve sliding contact surface 59. Therefore, even if the pressure of the coolant in the casing 21 increases, the valve sliding surface 59 of the seal cylinder member 37 can be prevented from being pressed against the peripheral wall portion 44 with excessive force. Therefore, when the control valve 8 of this embodiment is adopted, it is possible to avoid increasing the size and output of the drive unit 23 that rotationally drives the valve body 22, and also avoids increasing the size and output of the drive unit 23 that rotationally drives the valve body 22. It is possible to suppress early wear of types.

In this way, in this embodiment, the valve is pressed within a range in which the inward pressing force in the port axial direction acting on the seal cylinder member 37 is not less than the outward lifting force in the port axial direction acting on the seal cylinder member 37. The area S2 of the sliding surface 59 is set larger than the area S1 of the stepped surface 49. Therefore, it is possible to seal between the seal cylinder member 37 and the peripheral wall part 44 while suppressing pressing of the seal cylinder member 37 against the peripheral wall part 44 with excessive force.

[Details of the valve hole of the valve body]
FIG. 8 is a developed view of a portion of the peripheral wall portion 44 of the valve body 22 (the region in which the two valve holes 47 are formed).
The valve holes 47 and 47A formed in the peripheral wall portion 44 of the valve body 22 are not perfectly circular, and the circumferential width W1 along the circumferential direction of the peripheral wall portion 44 is wider than the axial width W2 along the axial direction of the peripheral wall portion 44. It is also formed into a narrow oval shape. Note that in this embodiment, the oval shape includes an elliptical shape, an elliptical shape, an oval shape, a rounded rectangular shape, and the like.

Further, the circumferential width W1 and the axial width W2 of the valve holes 47, 47A are set to satisfy the following equations (1) and (2).
R1≦W1<W2…(1)
W2<R2...(2)
R1: Inner diameter of the first cylindrical portion 56 of the seal cylindrical member 37 R2: Outer diameter of the second cylindrical portion 57 of the seal cylindrical member 37

Furthermore, it is more desirable that the circumferential width W1 of the valve holes 47, 47A is set to satisfy the following equation (3).
W1<R3...(3)
R3: Inner diameter of second cylindrical portion 57

[Control valve operation]
Next, the operation of the control valve 8 mentioned above will be explained.
As shown in FIG. 1, in the main flow path 10, the coolant sent out by the water pump 3 undergoes heat exchange with the engine 2, and then flows toward the control valve 8. The coolant that has passed through the engine 2 in the main flow path 10 flows into the casing 21 of the control valve 8 through the inlet 17 .

A portion of the coolant that has flowed into the casing 21 of the control valve 8 flows into the EGR outlet 63 . The coolant that has flowed into the EGR outlet 63 is supplied into the EGR passage 14 through the EGR joint 52. The coolant supplied into the EGR flow path 14 is returned to the main flow path 10 after heat exchange between the coolant and EGR gas is performed in the EGR cooler 7 .

On the other hand, among the coolant that has flowed into the casing 21 of the control valve 8, the coolant that has not flowed into the EGR outlet 63 is opened by the valve body 22 according to the rotational position of the valve body 22 within the casing 21. It is distributed to each of the flow paths 11 to 13 through any of the outlet ports (radiator outlet 60, bypass outlet 65, air conditioning outlet 68).

In the control valve 8, in order to switch the communication pattern between the valve hole and the outlet, the drive unit 23 rotates the valve body 22 around the axis O1. Then, by stopping the rotation of the valve body 22 at a position corresponding to a desired communication pattern, the valve hole and the outlet are communicated with each other in a communication pattern corresponding to the stop position of the valve body 22.

[Effects of embodiment]
As described above, in the control valve 8 of this embodiment, the valve holes 47 and 47A formed in the peripheral wall portion 44 of the valve body 22 have an oval shape in which the circumferential width W1 is narrower than the axial width W2. Therefore, if the same number of valve holes are to be formed on the outer circumference of the circumferential wall 44 of the valve body 22 (on the outer circumference in the same axial region), the circumferential length of the circumferential wall 44 of the valve body 22 should be shortened. Therefore, the outer diameter of the peripheral wall portion 44 can be made small.

Furthermore, in the control valve 8 of this embodiment, the circumferential width of the valve holes 47 and 47A is set to be equal to or larger than the inner diameter R1 of the first cylindrical portion 56 of the seal cylindrical member 37. Therefore, the pressure loss of the coolant is affected only by the inner diameter of the first cylindrical portion 56 of the seal cylindrical member 37, and is not affected by the circumferential width W1 of the valve holes 47, 47A.
Therefore, when the control valve 8 of the present embodiment is adopted, while suppressing a decrease in the flow rate of the coolant flowing out from the bypass outlet 65 and the radiator outlet 60, By reducing the diameter, the entire device (control valve 8) can be downsized.

Further, in the control valve 8 of the present embodiment, the valve holes 47, 47A of the valve body 22 have an oval shape in which the circumferential width W1 is narrower than the axial width W2, so that the valve holes 47, 47A are perfectly circular. Compared to the case where the shape is different, the amount of change in the communication area between the valve holes 47, 47A and the seal cylinder member 37 with respect to the moving speed of the valve body 22 in the circumferential direction can be increased. Therefore, when the control valve 8 of this embodiment is employed, a desired outflow flow rate can be quickly obtained by adjusting the rotation of the valve body 22.

Further, in the control valve 8 of this embodiment, the axial width W1 of the valve holes 47, 47A of the valve body 22 is set to be narrower than the outer diameter R2 of the second cylindrical portion 57 of the seal cylindrical member 37. . Therefore, when the valve body 22 is rotated to a position where the flow rate of the coolant from the bypass outlet 65 or the radiator outlet 60 is maximized, the valve sliding surface 59 of the seal cylinder member 37 This results in stable contact with the axially outer edges of the valve holes 47 and 47A of No. 22. Therefore, when this configuration is adopted, the state of the seal cylinder member 37 is stabilized when the valve body 22 is rotated to a position where the flow rate of the cooling liquid from the bypass outlet 65 or the radiator outlet 60 is maximized. can be done.

Furthermore, in the control valve 8 of this embodiment, the axial width W1 of the valve holes 47, 47A of the valve body 22 is set to be narrower than the outer diameter R2 of the second cylindrical portion 57 of the seal cylinder member 37. Therefore, when the seal cylinder member 37 communicates with the inside of the circumferential wall portion 44 of the valve body 22 through the valve holes 47, 47A, the coolant present on the outer circumferential side of the circumferential wall portion 44 passes through the valve holes 47, 47A. It becomes difficult to flow into the inside of the seal cylinder member 37. Therefore, when the control valve 8 of this embodiment is employed, it is possible to suppress unnecessary pressure fluctuations from occurring in the circumferential area of the seal cylinder member 37 that is in contact with the circumferential wall portion 44 of the valve body 22.

Further, in the control valve 8 of this embodiment, the circumferential width W1 of the valve holes 47 and 47A of the valve body 22 is set to be narrower than the inner diameter R3 of the second cylindrical portion 57 of the seal cylinder member 37. Therefore, when the valve body 22 is rotated to a position where the flow rate of the coolant from the bypass outlet 65 or the radiator outlet 60 is maximized, the valve sliding surface 59 of the seal cylinder member 37 This results in stable contact with the circumferentially outer edges of the valve holes 47 and 47A of No. 22. Therefore, when the control valve 8 of this embodiment is adopted, the seal cylinder member when the valve body 22 is rotated to a position where the flow rate of the coolant flowing out from the bypass outlet 65 or the radiator outlet 60 is maximized. 37 can be stabilized.

Further, in the control valve 8 of this embodiment, a stepped surface 49 is provided between the outer peripheral surface of the first cylindrical portion 56 and the outer peripheral surface of the second cylindrical portion 57 of the seal cylindrical member 37, and the stepped surface 49 is connected to the casing. It constitutes a biasing pressure receiving surface that biases the seal cylinder member 37 toward the valve body 22 in response to the pressure of the cooling fluid inside the valve body 21 . The area S1 of the urging pressure receiving surface and the area S2 of the valve sliding contact surface 59 of the seal cylinder member 37 are set so as to satisfy the above equations (4) and (5). Therefore, the pressing force of the coolant acting on the seal cylinder member 37 through the biasing pressure receiving surface (step surface 49) is applied to the seal cylinder when the coolant leaks from the gap between the valve sliding surface 59 and the valve body 22. This becomes a force greater than the lifting force acting on the member 37. Furthermore, since the area S1 of the biasing pressure receiving surface (step surface 49) of the seal cylinder member 37 is smaller than the area S2 of the valve sliding contact surface 59, even if the pressure of the coolant in the casing 21 increases, the seal cylinder member 37 can be prevented from being pressed against the valve body 22 with excessive force.
Therefore, when the control valve 8 of this embodiment is employed, it is possible to ensure good sealing performance while suppressing pressing of the seal cylinder member 37 against the valve body 22 with excessive force.

Note that the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the gist thereof.

8... Control valve 17... Inflow port 21... Casing 22... Valve body 37... Seal cylinder member 44... Surrounding wall part 47... Valve hole 49... Step surface 56... First cylinder part 57... Second cylinder part 59... Valve sliding contact surface 65...Bypass outlet (outlet)

Claims (4)

a casing having an inlet through which liquid flows from the outside and an outlet through which the liquid that has flowed into the inside flows out to the outside;
a valve body rotatably disposed inside the casing and having a peripheral wall portion in which a valve hole communicating inside and outside is formed;
One end in the axial direction communicates with the outflow port, and the other end in the axial direction slides on the outer peripheral surface of the peripheral wall at a position that at least partially overlaps the rotation path of the valve hole of the valve body. A control valve comprising: a seal cylinder member provided with an annular valve sliding contact surface that is movably abutted;
The seal cylinder member is
a first cylindrical portion located on the one end side and communicating with the outlet;
a second cylindrical portion located on the other end side, an end surface in the axial direction forming the valve sliding surface, and an inner diameter larger than the inner diameter of the first cylindrical portion;
The valve hole is formed in an oval shape in which a circumferential width along the circumferential direction of the peripheral wall portion is narrower than an axial width along the axial direction of the peripheral wall portion,
A control valve characterized in that the circumferential width W1 of the valve hole is set to satisfy equation (1).
R1≦W1<W2…(1)
R1: Inner diameter of the first cylindrical portion W2: Axial width of the valve hole The control valve according to claim 1, wherein the axial width W2 of the valve hole is set to satisfy equation (2).
W2<R2...(2)
R2: Outer diameter of the second cylindrical part The control valve according to claim 1 or 2, wherein the circumferential width W1 of the valve hole is set to satisfy equation (3).
W1<R3...(3)
R3: Inner diameter of the second cylinder part The seal cylindrical member is configured such that the outer diameter of the first cylindrical portion is smaller than the outer diameter of the second cylindrical portion, and the outer circumferential surface of the first cylindrical portion and the outer circumferential surface of the second cylindrical portion are formed. A step surface is provided on the
The stepped surface constitutes a biasing pressure receiving surface that biases the seal cylinder member toward the valve body in response to the pressure of the liquid inside the casing,
Claim 1, wherein an area S1 of the urging pressure receiving surface and an area S2 of the valve sliding contact surface of the seal cylinder member are set to satisfy formulas (4) and (5). The control valve according to any one of items 1 to 3.
S1<S2≦S1/k...(4)
α≦k<1 (5)
k: Pressure reduction constant of liquid flowing through the minute gap between the valve sliding surface and the valve body.
α: Lower limit value of the pressure reduction constant determined by the physical properties of the liquid.

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