JP2020159514A - Control valve - Google Patents

Abstract

To provide a control valve capable of suppressing leakage of liquid from a gap between a valve body and a seal cylindrical member in cold weather.SOLUTION: A valve body 22 has a convex spherical peripheral wall part 53B and a valve hole. A seal cylindrical member 131 has a concave spherical valve sliding contact surface 141a and a seal opening 90. A radius of curvature R1 of the outer peripheral surface of the valve body 22 at the time when liquid is at a reference temperature within a room temperature range, a radius of curvature R2 of the valve sliding contact surface 141a of the seal cylindrical member 131 at the time when the liquid is at the reference temperature within the room temperature range, a coefficient of linear expansion α1 of the valve body 22 and a coefficient of linear expansion α2 of the seal cylindrical member 131 are set to satisfy the following relational expressions (1) and (2): R1(1+α1×Δt)≥R2(1+α2×Δt) (1) and ΔT≤-25 (2), where ΔT represents the temperature difference between an actual liquid temperature and the reference temperature.SELECTED DRAWING: Figure 4

Description

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

In the cooling system that cools the engine using cooling water, in addition to the radiator flow path that circulates between the radiator and the engine, a bypass flow path that bypasses the radiator, a warm-up flow path that passes through the oil warmer, etc. are installed side by side. Sometimes. In this type of cooling system, a control valve is interposed at a branch portion of the flow path, and the flow path is appropriately switched by the control valve. As a control valve, a valve body is rotatably arranged in a casing, and an arbitrary flow path is opened and closed according to a rotation position of the valve body (see, for example, Patent Document 1).

The control valve described in Patent Document 1 is provided with an inflow port into which a liquid such as cooling water flows in and a plurality of outflow ports in which the inflowing liquid flows out to the outside in the casing. The valve body is arranged inside the casing, and has a peripheral wall portion having a convex spherical outer peripheral surface and a valve hole that communicates the inside and outside of the peripheral wall portion. A seal cylinder member is attached to the outlet of the casing. A concave spherical valve sliding contact surface that slides into the outer peripheral surface of the valve body is formed on the end surface of the seal cylinder member that faces the outer peripheral surface of the valve body. Further, the seal cylinder member is formed with a seal opening that communicates the inner region of the valve slide contact surface with the outlet side. The concave spherical valve sliding contact surface of the seal cylinder member is in sliding contact with the convex spherical outer peripheral surface of the valve body at a position where it wraps with the rotation path of the corresponding valve hole of the valve body.
The width of the valve hole in the direction intersecting the rotation direction of the valve body is set to be larger than the inner diameter of the seal opening of the seal cylinder member, and the radius of curvature of the convex spherical outer peripheral surface of the valve body is the seal cylinder. It is set so as to be equal to or less than the radius of curvature of the concave spherical valve sliding contact surface of the member.

When the valve body of the control valve is in a position where the seal opening of the seal cylinder member communicates with the corresponding valve hole, the valve body of the seal cylinder member allows the outflow of liquid from the inner region of the valve body to the corresponding outlet. When the seal opening is in a position that does not communicate with the corresponding valve hole, the outflow of liquid from the inner region of the valve body to the corresponding outlet is blocked. The rotation position of the valve body is controlled by an actuator such as an electric motor.

JP-A-2017-3064

The conventional control valve does not particularly consider expansion and contraction deformation of the valve body and the seal cylinder member in cold weather (cooling water temperature is 0 ° C. or less). Therefore, in cold weather, the contact state between the valve sliding contact surface of the seal cylinder member and the outer peripheral surface of the valve body may change due to the deformation of the valve body or the seal cylinder member due to the temperature change. In this case, there is a concern that the liquid in the casing may leak to the outlet side from the gap between the valve body and the seal cylinder member.

Therefore, the present invention is intended to provide a control valve capable of suppressing the leakage of liquid from the gap between the valve body and the seal cylinder member in cold weather.

The control valve according to the present invention adopts the following configuration in order to solve the above problems.
That is, the control valve according to the present invention is rotatably arranged inside the casing and has a casing having an inflow port where a liquid flows in from the outside and an outflow port where the liquid flowing into the inside flows out to the outside. A valve body having a peripheral wall portion having a convex spherical surface and a valve hole communicating with the inside and outside of the peripheral wall portion, and one end portion being held by the casing in a state of communicating with the outlet and being formed at the other end portion. The valve body includes a concave spherical valve sliding contact surface that is in sliding contact with the outer peripheral surface of the valve body, and a seal cylinder member having a seal opening that communicates the other end portion and the one end portion. Allows the outflow of liquid from the inner region of the peripheral wall portion to the outlet when the valve hole and the seal opening are in a rotating position to communicate with each other, and the valve body allows the valve hole and the seal opening to flow. In a control valve that blocks the outflow of liquid from the inner region of the peripheral wall portion to the outlet when the liquid is in a rotational position that does not allow communication, the outer peripheral surface of the valve body when the liquid is at a reference temperature in the normal temperature range. The radius of curvature R1 of the valve body, the radius of curvature R2 of the valve sliding contact surface of the seal cylinder member when the liquid is at a reference temperature in the normal temperature range, the linear expansion coefficient α1 of the valve body, and the linear expansion of the seal cylinder member. The coefficient α2 is characterized in that it is set so as to satisfy the equations (1) and (2).
R1 (1 + α1 · Δt) ≧ R2 (1 + α2 · Δt)… (1)
ΔT ≤ -25 ... (2)
ΔT: Temperature difference between the actual liquid temperature and the reference temperature

With the above configuration, when the valve body is in a rotational position where the valve hole and the seal opening are not communicated with each other, the communication between the valve hole and the outlet through the seal cylinder member is cut off. When the valve body rotates from this state and the seal opening of the seal cylinder member communicates (wraps) with the valve hole of the valve body, the liquid inside the valve body flows out to the outlet through the valve hole and the seal opening. In cold weather when the temperature of the liquid is 0 ° C or less, the actual radius of curvature of the valve sliding contact surface of the seal cylinder member is the actual curvature of the outer peripheral surface of the valve body according to the above equations (1) and (2). It is below the radius. For this reason, the valve sliding contact surface of the seal cylinder member easily comes into contact with the outer peripheral surface of the valve body from the portion closer to the outer side in the radial direction, and when a pressing load in the valve body direction acts on the seal cylinder member, the valve covers almost the entire radial direction. It comes into contact with the outer peripheral surface of the body. As a result, when the valve sliding contact surface of the seal cylinder member and the outer peripheral surface of the valve body are in surface contact with each other over a wide area and the valve hole and the outlet are not in communication with each other, the liquid in the casing is in contact with the valve sliding contact surface. Leakage to the outlet side through the gap on the outer peripheral surface of the valve body is suppressed.

The seal cylinder member has an urging pressure receiving surface that receives the pressure of the liquid inside the casing to urge the seal cylinder member toward the valve body side.
The area S1 of the pressure receiving surface for urging and the area S2 of the valve sliding contact surface of the seal cylinder member may be set so as to satisfy the equations (3) and (4).
S1 <S2≤S1 / k ... (3)
β ≦ k <1… (4)
k: Pressure reduction constant of the liquid flowing through the minute gap between the valve sliding contact surface and the valve body β: 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 pressure receiving surface for urging the seal cylinder member is equal to or larger than the area S2 of the valve slide contact surface of the seal cylinder member multiplied by the pressure reduction constant k. As a result, when the pressure of the liquid in the casing acts on the pressure receiving surface for urging and the peripheral region outside the valve sliding contact surface, the valve body due to the hydraulic pressure acting on the seal cylinder member through the pressure receiving surface for urging. The pressing force in the direction is greater than the lifting force from the valve body that acts on the seal cylinder member when the liquid leaks from the minute gap between the valve sliding contact surface and the valve body. Therefore, it is possible to maintain the valve sliding contact surface of the seal cylinder member in contact with the outer peripheral surface of the valve body. At this time, the desired pressure reduction constant k cannot be obtained unless the valve sliding contact surface of the seal cylinder member is in contact with the outer peripheral surface of the valve body substantially uniformly over a wide area in the radial direction. In the case of this configuration, even if the valve body and the seal cylinder member expand and contract in cold and cold, the valve sliding contact surface of the seal cylinder member contacts the outer peripheral surface of the valve body in a wide area, so that even in cold and cold. , The desired pressure reduction constant k can be obtained.
Further, in this configuration, since the area S1 of the pressure receiving surface for urging the seal cylinder member is smaller than the area S2 of the valve slide contact surface, the seal cylinder member is subjected to excessive force even if the pressure of the liquid in the casing increases. It is suppressed from being pressed against the valve body.
Therefore, according to this configuration, the area of the valve sliding contact surface is the pressure receiving surface for urging within a range in which the pressing force in the valve body direction by the liquid acting on the seal cylinder member does not fall below the lifting force acting on the seal cylinder member. Since the area is set to be larger than the area of, it is possible to secure good sealing performance while suppressing pressing of the sealing cylinder member against the valve body by an excessive force.

The present invention has a radius of curvature at a reference temperature of the outer peripheral surface of the valve body so that the actual radius of curvature of the valve sliding contact surface of the seal cylinder member is equal to or less than the actual radius of curvature of the outer peripheral surface of the valve body in cold weather. , The radius of curvature of the valve sliding contact surface of the seal cylinder member at the reference temperature, and each linear expansion coefficient of the valve body and the seal cylinder member are set. Therefore, in cold weather, the valve sliding contact surface of the seal cylinder member comes into contact with the outer peripheral surface of the valve body over a wide area in a state where a pressing load in the valve body direction is applied to the seal cylinder member. Therefore, according to the present invention, it is possible to suppress the leakage of the liquid from the gap between the valve body and the seal cylinder member in cold weather.

It is a block diagram of the cooling system which concerns on embodiment. It is a perspective view of the control valve which concerns on embodiment. It is an exploded perspective view of a part of the control valve which concerns on embodiment. It is sectional drawing which follows the IV-IV line of FIG. It is an enlarged view of V part of FIG.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following description, a case where the control valve of the present embodiment is adopted as the cooling system for cooling the engine using the coolant will be described.

[Cooling system]
FIG. 1 is a block diagram of the cooling system 1.
As shown in FIG. 1, the cooling system 1 is mounted on a vehicle having at least an engine as a vehicle drive source. 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 heat exchanger 5 (H / EX), a heater core 6 (HTR), an EGR cooler 7 (EGR), and a control. The valves 8 (EWV) are connected by various flow paths 10 to 14.
The water pump 3, the engine 2, and the control valve 8 are sequentially connected on the main flow path 10 from upstream to downstream. In the main flow path 10, the coolant (liquid) passes through the engine 2 and the control valve 8 in order by the operation of the water pump 3.

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

The radiator 4 is connected to the radiator flow path 11. In the radiator flow path 11, heat exchange between the coolant and the outside air is performed in the radiator 4.

A heat exchanger 5 is connected to the warm-up flow path 12. Engine oil circulates between the heat exchanger 5 and the engine 2 through an oil flow path 18. In the warm-up flow path 12, heat exchange between the coolant and the engine oil is performed in the heat exchanger 5. That is, the heat exchanger 5 functions as an oil warmer when the water temperature is higher than the oil temperature and heats the engine oil. On the other hand, the heat exchanger 5 functions as an oil cooler when the water temperature is lower than the oil temperature and cools the engine oil.

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 between the coolant and the air conditioning air flowing in the duct is performed in the heater core 6.

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

In the cooling system 1 described above, the cooling liquid that has passed through the engine 2 in the main flow path 10 flows into the control valve 8 and then is selectively distributed to the various flow paths 11 to 13 by the operation of the control valve 8. As a result, early temperature rise and high water temperature (optimal temperature) control can be realized, and the fuel efficiency of the vehicle is improved.

(Control valve)
FIG. 2 is a perspective view of the control valve 8. FIG. 3 is an exploded perspective view of a part of the control valve 8. Note that FIG. 3 is an exploded perspective view centering on the valve body 22 from which the casing 21 and the drive unit 23, which will be described later, are removed from the control valve 8.
As shown in FIGS. 2 and 3, the control valve 8 mainly includes a casing 21, a valve body 22 (see FIG. 3), and a drive unit 23.

(casing)
The casing 21 has a bottomed tubular casing main body 25 and a lid 26 that closes the opening of the casing main body 25. In the following description, the direction along the axis O1 of the casing 21 is simply referred to as the case axial direction. 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 the first side, and the direction toward the lid 26 with respect to the case peripheral wall 31 of the casing body 25 is referred to as the first side. It is called the second side. Further, the direction orthogonal to the axis O1 is referred to as the case radial direction, and the direction around the axis O1 is referred to as the case circumferential direction.

A plurality of mounting pieces 33 are formed on the case peripheral wall 31 of the casing main body 25. Each mounting piece 33 projects from the case peripheral wall 31 to the outside in the case radial direction. The control valve 8 is fixed in the engine chamber via, for example, each mounting piece 33. The position and number of the mounting pieces 33 can be changed as appropriate.

An inflow port 37 that bulges outward in the radial direction of the case is formed in a portion of the case peripheral wall 31 located on the second side. The inflow port 37 is formed with an inflow port (not shown) that penetrates the inflow port 37 in the radial direction of the case. The inflow port communicates with the inside and outside of the casing 21. The above-mentioned main flow path 10 (see FIG. 1) is connected to the open end surface (outer end surface in the case radial direction) of the inflow port 37.

A radiator port 41 that bulges outward in the case radial direction is formed at a position of the case peripheral wall 31 that faces the inflow port 37 with the axis O1 in between in the case radial direction. The radiator port 41 is formed with a fail opening (not shown) and a radiator outlet (outlet) arranged side by side in the case axial direction. The fail opening and the radiator outlet each penetrate the radiator port 41 in the radial direction of the case.

A radiator joint 42 is connected to the open end surface (outer end surface in the radial direction of the case) of the radiator port 41. The radiator joint 42 connects the radiator outlet and the upstream end of the radiator flow path 11 (see FIG. 1). The radiator joint 42 is welded (for example, vibration welding or the like) to the open end surface of the radiator port 41.

A thermostat (not shown) is provided at the fail opening. The thermostat opens and closes the fail opening according to the temperature of the coolant flowing in the casing 21.

An EGR outlet (not shown) is formed in a portion of the lid 26 located closer to the radiator port 41 in the case radial direction with respect to the axis O1. In the lid body 26, an EGR joint 52 is formed at the opening edge of the EGR outlet. The EGR joint 52 is formed in a tubular shape extending outward in the radial direction of the case toward the second side in the axial direction of the case, and is formed between the EGR outlet and the upstream end of the EGR flow path 14 (see FIG. 1) described above. You are connected.

A warm-up port (not shown) that bulges outward in the radial direction of the case is formed in a portion of the case peripheral wall 31 that is located on the first side in the case axial direction with respect to the radiator port 41. The warm-up port is formed with a warm-up outlet (outlet) that penetrates the warm-up port in the radial direction of the case. A warm-up joint 62 is connected to the open end face of the warm-up port. The warm-up joint 62 connects the warm-up outlet and the upstream end of the warm-up flow path 12 (see FIG. 1) described above. The warm-up joint 62 is welded (for example, vibration welding) to the open end surface of the warm-up port.

Of the case peripheral wall 31, at a position between the radiator port 41 in the case axial direction and the warm-up port (warm-up joint 62) and at a position deviated from the warm-up port by about 180 ° in the case circumferential direction. An air conditioning port 66 is formed. The air conditioning port 66 is formed with an air conditioning outlet 66a (outlet) that penetrates the air conditioning port 66 in the radial direction of the case. An air conditioning joint 68 is connected to the open end surface of the air conditioning port 66. The air conditioning joint 68 connects the air conditioning outlet 66a and the upstream end of the air conditioning flow path 13 (see FIG. 1) described above. The air conditioning joint 68 is welded (for example, vibration welding) to the open end surface of the air conditioning port 66.

(Drive unit)
The drive unit 23 is attached to the bottom wall portion 32 of the casing main body 25. In the drive unit 23, a motor, a speed reduction mechanism, a control board, and the like (not shown) are housed in a unit case. The drive unit 23 rotates the valve body 22, which will be described later, based on a command from a control device (not shown).

(Valve body)
The valve body 22 shown in FIG. 3 is rotatably housed inside the casing 21 shown in FIG. As shown in FIG. 3, in the valve body 22, three convex spherical peripheral wall portions 53A, 53B, and 53C are connected in a direction along the axis O1. The valve body 22 is arranged coaxially with the axis O1 of the casing 21 inside the casing 21. The valve body 22 opens and closes each of the above-mentioned outlets (radiator outlet, warm-up outlet, and air-conditioning outlet 66a) by rotating around the axis O1.

The valve body 22 is provided with a shaft portion 73 (rotating shaft) coaxially with the peripheral wall portions 53A, 53B, 53C inside the triple peripheral wall portions 53A, 53B, 53C. The shaft portion 73 is integrally connected to the peripheral wall portions 53A, 53B, and 53C via the spoke portions 74. The shaft portion 73 is rotatably supported on the casing 21 via a bearing (not shown), and is arranged inside the casing 21 along the axis O1. The end of the shaft portion 73 is connected to the drive unit 23 described above. The valve body 22 is rotated by the drive unit 23 through the shaft portion 73.

The triple peripheral wall portions 53A, 53B, and 53C are arranged in a portion of the casing 21 located on the first side in the case axial direction with respect to the inflow port (inflow port 37). Specifically, the peripheral wall portions 53A, 53B, and 53C are arranged at positions that avoid the fail opening and straddle the radiator outlet, the air conditioning outlet 66a, and the warm-up outlet in the case axial direction. Inside the triple peripheral wall portions 53A, 53B, and 53C, the cooling liquid that has flowed into the casing 21 through the inflow port flows in along the case axial direction. The peripheral wall portion 53A located on the second side in the case axial direction is arranged so as to face the radiator outlet in the case radial direction, and the peripheral wall portion 53C located on the first side in the case axial direction is a warm-up flow. It is arranged so as to face the outlet in the radial direction of the case. The central peripheral wall portion 53B is arranged so as to face the air conditioning outlet 66a in the radial direction of the case. A gap is provided in the radial direction of the case between the outer peripheral surfaces of the peripheral wall portions 53A, 53B, and 53C and the inner peripheral surface of the case peripheral wall 31.

The peripheral wall portion 53A is formed with a valve hole 95 that penetrates the peripheral wall portion 53A in the radial direction of the case. The valve hole 95 is formed at the same position in the case axial direction as the radiator outlet on the casing 21 side. The valve hole 95 is formed in the shape of an elongated hole having a longitudinal direction along the outer peripheral surface of the peripheral wall portion 53A. When the valve hole 95 overlaps with the seal cylinder member 131 inserted into the radiator outlet when viewed from the case radial direction, the valve hole 95 and the seal cylinder member 131 communicate the inside of the peripheral wall portion 53A with the radiator outlet. As a result, the coolant in the casing 21 flows out to the radiator flow path 11 (see FIG. 1) through the radiator outlet.

The peripheral wall portion 53B is formed with a valve hole 96 that penetrates the peripheral wall portion 53B in the radial direction of the case. The valve hole 96 is formed at the same position in the case axial direction as the air conditioning outlet 66a on the casing 21 side. The valve hole 96 is formed in the shape of an elongated hole having a length along the outer peripheral surface of the peripheral wall portion 53B. When the valve hole 96 overlaps with the seal cylinder member 131 inserted into the air conditioning outlet 66a when viewed from the case radial direction, the valve hole 96 and the seal cylinder member 131 communicate the inside of the peripheral wall portion 53B with the air conditioning outlet 66a. .. As a result, the cooling liquid in the casing 21 flows out to the air conditioning flow path 13 (see FIG. 1) through the air conditioning outlet 66a.

Further, the peripheral wall portion 53C is formed with a valve hole 97 that penetrates the peripheral wall portion 53C in the radial direction of the case. The valve hole 97 is formed at the same position in the case axial direction as the warm-up outlet on the casing 21 side. In the case of this embodiment, the valve hole 97 is formed in a circular shape. When the valve hole 97 overlaps with the seal cylinder member 131 inserted into the warm-up outlet when viewed from the case radial direction, the valve hole 97 and the seal cylinder member 131 communicate the inside of the peripheral wall portion 53C with the warm-up outlet. .. As a result, the cooling liquid in the casing 21 flows out to the warm-up flow path 12 (see FIG. 1) through the warm-up outlet.

The valve body 22 switches between communication and cutoff between the valve holes 95, 96, 97 and the respective outlets corresponding to them as the valve body 22 rotates around the axis O1. The communication pattern between the valve holes 95, 96, 97 and the outlet can be set as appropriate.

Next, the details of the connection portion of the air conditioning port 66 and the air conditioning joint 68 will be described. The connection portion between the radiator port 41 and the radiator joint 42 and the connection portion between the warm-up port and the warm-up joint 62 have the same configuration as the connection portion between the air conditioning port 66 and the air conditioning joint 68. Omit.

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 2, and FIG. 5 is an enlarged view of the V portion of FIG. In the following description, the direction along the axis O2 of the air conditioning outlet 66a may be referred to as the port axial direction (first direction). In this case, in the port axial direction, the direction toward the axis O1 with respect to the air conditioning port 66 is referred to as the inside, and the direction away from the axis O1 with respect to the air conditioning port 66 is referred to as the outside. Further, the direction orthogonal to the axis O2 may be referred to as the port radial direction (second direction), and the direction around the axis O2 may be referred to as the port circumferential direction.
As shown in FIG. 4, the air conditioning port 66 has a seal cylinder portion 101 extending in the port axial direction and a port flange portion 102 projecting outward from the seal cylinder portion 101 in the port radial direction. The inside of the seal cylinder 101 constitutes the above-mentioned air conditioning outlet 66a (outlet). The inner diameter of the seal cylinder portion 101 is uniformly set over the entire area in the port axial direction.

The air-conditioning joint 68 has a joint cylinder portion 110 arranged coaxially with the axis O2, and a joint flange portion 111 projecting from the inner end portion of the joint cylinder portion 110 in the port axial direction to the outside in the port radial direction. There is. The joint flange portion 111 is overlapped with the port flange portion 102 of the air conditioning port 66 in the port axial direction. The air-conditioning port 66 and the air-conditioning joint 68 are joined to each other by vibration-welding the facing surfaces of the port flange portion 102 and the joint flange portion 111.

The joint cylinder portion 110 extends from the inner peripheral edge of the joint flange portion 111 to the outside in the port axial direction. The joint tubular portion 110 is formed in a multi-stage tubular shape whose diameter is gradually reduced toward the outside in the port axial direction. Specifically, in the joint cylinder portion 110, the large diameter portion 121, the medium diameter portion 122, and the small diameter portion 123 are sequentially connected to the outside in the port axial direction.

The large-diameter portion 121 surrounds the seal cylinder portion 101 in a state of being spaced outside in the port radial direction with respect to the seal cylinder portion 101 described above. The medium diameter portion 122 faces the seal cylinder portion 101 with a gap Q1 in the port axial direction.

A seal mechanism 130 is provided in a portion surrounded by the air conditioning port 66 and the air conditioning joint 68. The seal mechanism 130 includes a seal cylinder member 131, an urging member 132, a seal ring 133, and a holder 134. As shown in FIG. 3, a seal mechanism 130 having the same configuration as the seal mechanism 130 provided in the air conditioning port 66 is also provided in the radiator port 41 and the warm-up port described above. In the description of the present embodiment, the seal mechanism 130 provided in the radiator port 41 and the warm-up port will be designated by the same reference numerals as the seal mechanism 130 provided in the air conditioning port 66, and the description thereof will be omitted.

As shown in FIGS. 4 and 5, a part of the seal cylinder member 131 is inserted into the air conditioning outlet 66a. The seal cylinder member 131 has a peripheral wall extending coaxially with the axis O2. The peripheral wall of the seal cylinder member 131 is formed in a multi-stage cylinder shape in which the outer diameter is gradually reduced toward the outside in the port axial direction. Specifically, the peripheral wall of the seal cylinder member 131 is located on the outside in the port axial direction (one end side in the axial direction), and is connected to the first cylinder portion 142 communicating with the downstream side of the air conditioning outlet 66a and the port axial direction. It is located on the inner side (the other end side in the axial direction) and has a second tubular portion 141 having an inner diameter and an outer diameter larger than that of the first tubular portion 142. The inner peripheral surfaces of the first cylinder portion 142 and the second cylinder portion 141 form a seal opening 90 that communicates the outer end (one end) and the inner end (other end) of the seal cylinder member 131 in the port axial direction. ing.

In the seal cylinder member 131, a large-diameter second cylinder portion 141 is slidably inserted into the inner peripheral surface of the seal cylinder portion 101. The inner end surface of the second tubular portion 141 in the port axial direction is a valve sliding contact surface 141a that slidably abuts on the convex spherical outer peripheral surface of the peripheral wall portion 53B of the valve body 22. The valve slide contact surface 141a is formed in a concave spherical shape, and is in surface contact with the convex spherical outer peripheral surface of the peripheral wall portion 53B.

The outer peripheral surface of the first tubular portion 142 is connected to the outer peripheral surface of the second tubular portion 141 via a stepped surface 143. The stepped surface 143 is inclined outward in the port radial direction toward the inside in the port axial direction, and then extends further outward in the port radial direction. Therefore, a seal gap Q2 is provided in the port radial direction between the outer peripheral surface of the small diameter first cylinder portion 142 and the inner peripheral surface of the seal cylinder portion 101.

The outer end surface of the first tubular portion 142 in the port axial direction (hereinafter, referred to as “seat surface 142a”) is a flat surface orthogonal to the port axial direction. The seat surface 142a of the first cylinder portion 142 is arranged at a position equivalent to the outer end surface of the seal cylinder portion 101 in the port axial direction. The seal cylinder member 131 is separated from the air conditioning joint 68 in the port radial direction and the port axial direction.

The urging member 132 is interposed between the seat surface 142a of the seal cylinder member 131 and the inner end surface of the small diameter portion 123 of the air conditioning joint 68 in the port axial direction. The urging member 132 is, for example, a wave spring. The urging member 132 urges the seal cylinder member 131 inward in the port axial direction (toward the peripheral wall portion 53B).

The seal ring 133 is, for example, a Y packing. The seal ring 133 is extrapolated to the first cylinder portion 142 of the seal cylinder member 131 with the opening (forked portion) facing inward in the port axial direction. Specifically, in the state where the seal ring 133 is arranged in the seal gap Q2 described above, each tip of the bifurcated portion slides on the outer peripheral surface of the first cylinder portion 142 and the inner peripheral surface of the seal cylinder portion 101, respectively. Close to possible. In the seal gap Q2, the inner region in the port axial direction with respect to the seal ring 133 is inside the casing 21 through the gap between the inner peripheral surface of the seal cylinder portion 101 and the second cylinder portion 141 of the seal cylinder member 131. Hydraulic pressure is introduced. The stepped surface 143 is formed in a direction opposite to the valve sliding contact surface 141a of the seal cylinder member 131 in the port axial direction. The stepped surface 143 constitutes an urging pressure receiving surface that receives the hydraulic pressure of the cooling liquid in the casing 21 and is pressed inward in the port axial direction.

Here, in the seal cylinder member 131, the area S1 of the stepped surface 143 (pressure receiving surface for urging) and the area S2 of the valve sliding contact surface 141a are set so as to satisfy the following equations (3) and (4). Has been done.
S1 <S2≤S1 / k ... (3)
β ≦ k <1… (4)
k: Pressure reduction constant of the coolant flowing through a minute gap between the valve sliding contact surface 141a and the peripheral wall portion 53B of the valve body 22 β: Lower limit value of the pressure reduction constant determined by the physical properties of the coolant The area of the stepped surface 143 The area S2 of S1 and the valve sliding contact surface 141a means the area when projected in the port axial direction.

Β in the formula (4) is a standard value of a pressure reduction constant determined by the type of coolant, the usage environment (for example, temperature), and the like. For example, under normal use conditions, β = 1/2 in the case of water. When the physical properties of the coolant used change, it changes to β = 1/3 or the like.
Further, the pressure reduction constant k in the equation (4) is a standard value of the pressure reduction constant when the valve sliding contact surface 141a is uniformly in contact with the peripheral wall portion 53B from the outer edge to the inner edge in the port radial direction. It becomes β (for example, 1/2). However, due to manufacturing error, assembly error, etc. of the seal cylinder member 131, the gap between the outer peripheral portion of the valve slide contact surface 141a and the peripheral wall portion 53B is slightly increased with respect to the inner peripheral portion of the valve slide contact surface 141a. Sometimes. In this case, the pressure reduction constant k in the equation (4) gradually approaches k = 1.

In the present embodiment, it is assumed that there is a minute gap between the valve slide contact surface 141a of the seal cylinder member 131 and the outer peripheral surface of the peripheral wall portion 53B to allow sliding, and the step surface 143 and the valve slide. The relationship between the areas S1 and S2 of the contact surface 141a is determined by the equations (3) and (4).
That is, as described above, the pressure of the coolant in the casing 21 acts as it is on the stepped surface 143 of the seal cylinder member 131. On the other hand, the pressure of the coolant in the casing 21 does not act on the valve slide contact surface 141a as it is. Specifically, the pressure of the coolant is accompanied by a pressure decrease when the coolant flows from the outer edge to the inner edge in the port radial direction through a minute gap between the valve sliding contact surface 141a and the peripheral wall portion 53B. It works while. At this time, the pressure of the coolant gradually decreases toward the inside in the port radial direction, and tries to push up the seal cylinder member 131 to the outside in the port axial direction.

As a result, a force obtained by multiplying the area S1 of the stepped surface 143 by the pressure P in the casing 21 acts as it is on the stepped surface 143 of the seal cylinder member 131. On the other hand, a force acting on the valve slide contact surface 141a of the seal cylinder member 131 by multiplying the area S2 of the valve slide contact surface 141a by the pressure P in the casing 21 and the pressure reduction constant k.

As is clear from the equation (3), the area S1 and S2 of the control valve 8 of the present embodiment are set so that k × S2 ≦ S1 holds. Therefore, the relationship of P × k × S2 ≦ P × S1 also holds.
Therefore, the pressing force F1 (F1 = P × S1) acting on the stepped surface 143 of the seal cylinder member 131 is the lifting force F2 (F2 = P × S1) acting on the valve slide contact surface 141a of the seal cylinder member 131. It becomes larger than k × S2). Therefore, in the control valve 8 of the present embodiment, the seal cylinder member 131 and the peripheral wall portion 53B can be sealed only by the relationship of the pressure of the coolant in the casing 21.

On the other hand, in the present embodiment, as described above, the area S1 of the stepped surface 143 of the seal cylinder member 131 is smaller than the area S2 of the valve sliding contact surface 141a. Therefore, even if the pressure of the coolant in the casing 21 increases, it is possible to prevent the valve sliding contact surface 141a of the seal cylinder member 131 from being pressed against the peripheral wall portion 53B by an excessive force. Therefore, when the control valve 8 of the present 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 the seal cylinder member 131 and each bush 78. Premature wear of 84 (see FIG. 4) can be suppressed.

As described above, in the present embodiment, the valve does not fall below the inward pressing force acting on the seal cylinder member 131 in the port axial direction and the outward lifting force acting on the seal cylinder member 131 in the port axial direction. The area S2 of the sliding contact surface 141a is set to be larger than the area S1 of the stepped surface 143. Therefore, it is possible to seal between the seal cylinder member 131 and the peripheral wall portion 53B while suppressing the pressing of the seal cylinder member 131 against the peripheral wall portion 53B by an excessive force.

The holder 134 described above is configured to be movable in the port axial direction with respect to the air conditioning port 66 and the air conditioning joint 68 in the gap Q1. Further, the holder 134 is arranged at least one of the air conditioning port 66 and the air conditioning joint 68 so as to be separable in the port axial direction. The holder 134 has a holder cylinder portion 151, a holder flange portion 152, and a regulation portion 153.

The holder cylinder portion 151 extends in the port axial direction. The holder cylinder portion 151 is inserted into the seal gap Q2 from the outside in the port axial direction. The bottom portion of the seal ring 133 described above can be brought into contact with the inner end surface of the holder cylinder portion 151 in the port axial direction. That is, the holder cylinder portion 151 restricts the movement of the seal ring 133 to the outside in the port axial direction.

The holder flange portion 152 projects from the outer end portion of the holder cylinder portion 151 in the port axial direction to the outside in the port radial direction. The holder flange portion 152 is arranged in the gap Q1 between the outer end surface of the seal cylinder portion 101 in the port axial direction and the inner end surface of the medium diameter portion 122 in the port axial direction. The inward movement of the holder 134 in the port axial direction is regulated by the seal cylinder portion 101, and the outward movement of the holder 134 in the port axial direction is regulated by the medium diameter portion 122.

The regulation portion 153 is formed so as to protrude outward in the port axial direction from the inner peripheral portion of the holder cylinder portion 151 in a tubular shape. The regulating unit 153 regulates the movement of the urging member 132 in the port radial direction together with the holder cylinder portion 151.

(Details of the peripheral wall of the valve body and the seal cylinder member)
The peripheral wall portions 53A, 53B, 53C of the valve body 22 and the seal cylinder member 131 are made of, for example, a resin material containing polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyamide (PA) or the like as main components. It is formed. As the resin material constituting the peripheral wall portions 53A, 53B, 53C and the resin material constituting the seal cylinder member 131, glass fiber, carbon fiber, etc. are appropriately used in consideration of impact resistance, low friction, low wear resistance, etc. It is mixed.

The coefficient of linear expansion α1 of the resin material constituting the peripheral wall portions 53A, 53B, 53C is, for example, 1 × ^10-5 to 10 × ^10-5 / K. On the other hand, the linear expansion coefficient α2 of the resin material constituting the seal cylinder member 131 is larger than the linear expansion coefficient α1 of the resin material constituting the peripheral wall portions 53A, 53B, 53C. Therefore, the amount of change with respect to the temperature change is larger in the seal cylinder member 131.

Here, the radius of curvature of the convex spherical outer peripheral surface of the peripheral wall portions 53A, 53B, 53C when the coolant is at a reference temperature in the room temperature range (20 ° C. to 25 ° C.) is R1, and the coolant is in the room temperature range (20 ° C.). Assuming that the radius of curvature of the concave spherical valve sliding contact surface 141a of the seal cylinder member 131 at the reference temperature of ° C. to 25 ° C. is R2, each of these radii of curvature R1 and R2 and the linear expansion of each resin material The coefficients α1 and α2 are set so as to satisfy the following equations (1) and (2).
R1 (1 + α1 · Δt) ≧ R2 (1 + α2 · Δt)… (1)
ΔT ≤ -25 ... (2)
ΔT: Temperature difference between the actual coolant temperature and the reference temperature

Therefore, in a temperature environment where the temperature of the coolant is 0 ° C. or lower, the actual radius of curvature of the concave spherical valve sliding contact surface 141a of the seal cylinder member 131 is determined by the above equations (1) and (2). It is equal to or less than the actual radius of curvature of the convex spherical outer peripheral surface of each peripheral wall portion 53A, 53B, 53C. Therefore, in a temperature environment where the temperature of the coolant is 0 ° C. or lower, the concave spherical valve sliding contact surface 141a of each seal cylinder member 131 is a convex spherical outer peripheral surface of the corresponding peripheral wall portions 53A, 53B, 53C. On the other hand, it becomes easier to contact from the outer peripheral edge portion (the portion closer to the outer side in the radial direction).
Therefore, the seal cylinder member 131 receives the hydraulic pressure of the coolant and the urging force of the urging member 132, and the outer peripheral surfaces of the corresponding peripheral wall portions 53A, 53B, 53C (the portions where the valve holes 95, 96, 97 do not exist). When pressed against, the valve slide contact surface 141a comes into contact with the outer peripheral surfaces of the corresponding peripheral wall portions 53A, 53B, 53C in almost the entire radial direction.

[Operation method of control valve]
Next, the operation method of the control valve 8 described above will be described.
As shown in FIG. 1, in the main flow path 10, the coolant sent out by the water pump 3 flows toward the control valve 8 after heat exchange in the engine 2. The coolant that has passed through the engine 2 in the main flow path 10 flows into the inside of the casing 21 through the inflow port.

Of the coolant that has flowed into the casing 21, some of the coolant flows into the EGR outlet. The coolant flowing into the EGR outlet is supplied into the EGR flow path 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 the EGR gas is performed in the EGR cooler 7.

On the other hand, among the coolants that have flowed into the casing 21, the coolants that have not flowed into the EGR outlet are distributed to each outlet in the process of flowing in the case axial direction. That is, the cooling liquid flowing in the case axial direction is distributed to the flow paths 11, 13 and 12 through the outlets communicating with the corresponding valve holes 95, 96 and 97 among the outlets.

In the control valve 8, in order to switch the communication pattern between the valve hole and the outlet, the valve body 22 is rotated around the axis O1. Then, by stopping the rotation of the valve body 22 at a position corresponding to the communication pattern to be set, the valve hole and the outflow port communicate with each other in a communication pattern corresponding to the stop position of the valve body 22.

[Effect of Embodiment]
As described above, the control valve 8 of the present embodiment has the radius of curvature of the outer peripheral surfaces of the peripheral wall portions 53A, 53B, 53C of the valve body 22 when the coolant is at the reference temperature in the room temperature range (20 ° C. to 25 ° C.). R1, the radius of curvature R2 of the valve sliding contact surface 141a of the seal cylinder member 131 when the coolant is at a reference temperature in the room temperature range (20 ° C to 25 ° C), and the resin constituting the peripheral wall portions 53A, 53B, 53C. The linear expansion coefficient α1 of the material and the linear expansion coefficient α2 of the resin material constituting the seal cylinder member 131 are set so as to satisfy the above equations (1) and (2). Therefore, in cold weather, the actual radius of curvature of the valve sliding contact surface 141a of the seal cylinder member 131 is the outer peripheral surface of the peripheral wall portions 53A, 53B, 53C on the valve body 22 side due to expansion and contraction deformation due to the temperature change of each resin. It will be less than the actual radius of curvature.
Therefore, in the case of the control valve 8 of the present embodiment, when the seal cylinder member 131 is pressed against the outer peripheral surfaces of the peripheral wall portions 53A, 53B, 53C in cold weather, the peripheral area of the valve sliding contact surface 141a becomes the corresponding peripheral wall portion. It comes into contact with the outer peripheral surfaces of 53A, 53B, and 53C over a wide area (diameter width). Therefore, when the control valve 8 of the present embodiment is adopted, it is possible to suppress leakage of the cooling liquid from the gap between the valve body 22 and the seal cylinder member 131 in cold weather.

Further, in the control valve 8 of the present embodiment, the area S1 of the stepped surface 143, which is the pressure receiving surface for urging the seal cylinder member 131, and the area S2 of the valve sliding contact surface 141a are the above equations (3) and (4). ) Is set to be satisfied. Therefore, when the hydraulic pressure of the cooling liquid inside the casing 21 acts on the stepped surface 143 (pressure receiving surface for urging) and the peripheral region outside the valve sliding contact surface 141a, the seal cylinder member passes through the stepped surface 143. The pressing force in the valve body 22 direction due to the hydraulic pressure acting on 131 is greater than the lifting force due to the coolant acting on the gap between the valve sliding contact surface 141a and the peripheral wall portions 53A, 53B, 53C. Therefore, in the control valve 8 of the present embodiment, the valve sliding contact surface 141a of the seal cylinder member 131 is brought into contact with the outer peripheral surfaces of the peripheral wall portions 53A, 53B, 53C without increasing the urging force of the urging member 132. Can be maintained in a state.
Further, in this configuration, since the area S1 of the stepped surface 143 of the seal cylinder member 131 is smaller than the area S2 of the valve sliding contact surface 141a, the seal cylinder member 131 can be used even if the pressure of the coolant inside the casing 21 increases. It is possible to prevent the peripheral wall portions 53A, 53B, and 53C from being pressed by an excessive force.

Further, in the control valve 8 of the present embodiment, even if the peripheral wall portions 53A, 53B, 53C of the valve body 22 and the seal cylinder member 131 may expand and contract when the temperature of the coolant is cold or less of 0 ° or less, the above-mentioned As shown, the valve sliding contact surface 141a of the seal cylinder member 131 can be brought into contact with the outer peripheral surfaces of the peripheral wall portions 53A, 53B, 53C over a wide area. Therefore, even in cold weather, the outer peripheral edge portion of the valve slide contact surface 141a is prevented from rising from the outer peripheral surface of the corresponding peripheral wall portions 53A, 53B, 53C, and the step surface 143 and the valve slide contact surface 141a are prevented from rising. It is possible to maintain a constant balance of forces due to the coolant acting on. Therefore, even in cold weather, the space between the valve hole and the outlet can be stably maintained in a shutoff state by the seal cylinder member 131.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist thereof.

8 ... Control valve 21 ... Casing 22 ... Valve body 53A, 53B, 53C ... Peripheral wall portion 66a ... Air conditioning outlet (outlet)
90 ... Seal opening 95, 96, 97 ... Valve hole 131 ... Seal cylinder member 141a ... Valve sliding contact surface 143 ... Step surface (pressure receiving surface for urging)

Claims (2)

A casing having an inflow port where a liquid flows in from the outside and an outflow port where the liquid flowing into the inside flows out to the outside.
A valve body that is rotatably arranged inside the casing and has a peripheral wall portion having a convex spherical outer peripheral surface and a valve hole that communicates with the inside and outside of the peripheral wall portion.
A concave spherical valve sliding contact surface formed at the other end and in sliding contact with the outer peripheral surface of the valve body, and the other end and the one end are held in a state where one end communicates with the outlet. A seal cylinder member having a seal opening for communicating with the portion,
When the valve body is in a rotational position for communicating the valve hole and the seal opening, the liquid is allowed to flow out from the inner region of the peripheral wall portion to the outlet, and the valve body is formed with the valve hole. In a control valve that blocks the outflow of liquid from the inner region of the peripheral wall portion to the outlet when the seal opening is in a rotational position that does not communicate with the seal opening.
The radius of curvature R1 of the outer peripheral surface of the valve body when the liquid is at a reference temperature in the room temperature range, and the radius of curvature R2 of the valve sliding contact surface of the seal cylinder member when the liquid is at a reference temperature in the room temperature range. The control valve is characterized in that the linear expansion coefficient α1 of the valve body and the linear expansion coefficient α2 of the seal cylinder member are set so as to satisfy the equations (1) and (2).
R1 (1 + α1 · Δt) ≧ R2 (1 + α2 · Δt)… (1)
ΔT ≤ -25 ... (2)
ΔT: Temperature difference between the actual liquid temperature and the reference temperature The seal cylinder member has an urging pressure receiving surface that receives the pressure of the liquid inside the casing to urge the seal cylinder member toward the valve body side.
Claim 1 is characterized in that the area S1 of the pressure receiving surface for urging and the area S2 of the valve sliding contact surface of the seal cylinder member are set so as to satisfy the equations (3) and (4). The control valve described in.
S1 <S2≤S1 / k ... (3)
β ≦ k <1… (4)
k: Pressure reduction constant of the liquid flowing through the minute gap between the valve sliding contact surface and the valve body β: Lower limit value of the pressure reduction constant determined by the physical properties of the liquid

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