JP7579690B2 - Control valve - Google Patents

Description

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

In a cooling system that uses coolant to cool an engine, a bypass flow path that bypasses the radiator and an air conditioning flow path that heats the conditioned air may be installed in addition to the radiator flow path that circulates between the radiator and the engine. In this type of cooling system, a control valve is installed at the branch point of the flow path, and the flow path is appropriately switched by the control valve. A known control valve has a valve body having a peripheral wall portion (cylindrical wall) that is rotatably arranged inside the casing, and any flow path is opened or closed depending on the rotational position of the valve body (see, for example, Patent Document 1).

The control valve described in Patent Document 1 has a casing provided with an inlet through which liquid such as a coolant flows in, and a set number of outlets for discharging the inlet liquid to the outside. A plurality of valve holes communicating the inside and outside are formed in the peripheral wall of the valve body, corresponding to the plurality of outlets. In addition, one end side of a cylindrical sealing tube member is held in each outlet of the casing. The other end side of each sealing tube member is provided with a valve sliding surface that slidably abuts against the outer peripheral surface of the peripheral wall of the valve body. The valve sliding surface of each sealing tube member slides against the outer peripheral surface of the peripheral wall at a position overlapping the rotation path of the corresponding valve hole of the valve body. Each sealing tube member is opened and closed by the corresponding valve hole on the valve body.

The valve element allows the liquid to flow from the inner region of the peripheral wall to the corresponding outlet when the sealing cylinder member is in a rotational position where it communicates with the corresponding valve hole, and blocks the liquid from flowing from the inner region of the peripheral wall to the corresponding outlet when the sealing cylinder member is in a rotational position where it does not communicate with the corresponding valve hole. The rotational position of the valve element is operated by an actuator such as an electric motor.
A drive shaft for transmitting the power of the actuator to the valve disc is disposed at the axial center position of the peripheral wall of the valve disc. A connecting wall for connecting the peripheral wall to the drive shaft is integrally formed at one axial end of the peripheral wall of the valve disc. The connecting wall extends radially inward from the axial end of the peripheral wall, and its radially inner end is connected to the drive shaft. An end wall on one axial end side (actuator side) of the casing is disposed adjacent to the axial outside of the connecting wall.

JP 2015-96736 A

However, in the control valve described in Patent Document 1, the connecting wall connecting the peripheral wall of the valve body and the drive shaft extends radially inward from one axial end of the peripheral wall, and the radially outer end of the connecting wall becomes an obstacle, preventing the end wall of the casing from fully entering the axially inward direction of the peripheral wall. This increases the inflow volume of liquid inside the peripheral wall of the valve body, and increases the amount of liquid flowing through a liquid distribution system (for example, the above-mentioned cooling system) that includes the control valve. And when the amount of liquid flowing through the liquid distribution system increases, it takes a long time to control each part in the liquid distribution system to the desired temperature, and friction in the engine, which is the driving source, increases.

Therefore, the present invention aims to provide a control valve that can reduce the inflow volume of liquid inside the peripheral wall of the valve body, thereby quickly controlling each part in the liquid distribution system to the desired temperature.

In order to solve the above problems, the control valve according to the present invention employs the following configuration.
That is, the control valve according to the present invention comprises a casing having an inlet through which liquid flows in from the outside and an outlet through which the liquid that has flowed in the inside flows out to the outside, a valve body rotatably arranged inside the casing and having a valve hole formed near one end in the axial direction of a peripheral wall portion, a sealing cylindrical member having one end communicating with the outlet port and the other end abutting against an outer circumferential surface of the peripheral wall portion and opened and closed by the valve hole, and a drive shaft arranged at the axial center position of the valve body and transmitting rotational power to the valve body, the valve body being arranged between the peripheral wall portion and the peripheral wall portion in the axial direction. the casing has a connecting wall which connects a position near one end of the casing to the drive shaft, the connecting wall extending radially inward from an axially inner position of the peripheral wall portion further than the edge of the valve hole near the one end to form a concave portion which opens to the axial one end side of the peripheral wall portion, the end wall near the axial one end of the casing bulges out to enter the concave portion, and the radially outer end of the connecting wall is connected to the edge of the valve hole near the one end via a connection portion which is recessed radially inward from the outer circumferential surface of the peripheral wall portion .

In the above configuration, the outer peripheral edge of the connecting wall of the valve body is positioned so that it is recessed significantly axially inward from the end portion near one end of the peripheral wall portion, so that the bulging portion of the end wall near one end of the casing in the axial direction can be inserted significantly into the recessed portion. As a result, it is possible to reduce the inflow volume of liquid flowing inside the peripheral wall portion of the valve body.

In this case, the connecting wall is connected to the edge of the valve hole by the connecting wall even at the circumferential position where the valve hole is located. Therefore, when this configuration is adopted, the rigidity of the joint between the connecting wall and the peripheral wall portion can be increased.

The sealing tube member has an annular valve sliding surface that slidably contacts the outer peripheral surface of the peripheral wall portion, and an edge near one end of the valve hole and an edge near the other end opposite the edge may be configured to contact a radially outer position of the valve sliding surface of the sealing tube member relative to the inner peripheral end.

In this case, the edge near one end of the valve hole and the edge near the other end are in sliding contact with the valve contact surface at a position radially outward of the inner peripheral end of the valve contact surface of the sealing tube member. Therefore, even if wear occurs on the valve contact surface of the sealing tube member over time, the worn portion does not extend over the inner peripheral end of the sealing tube member. Therefore, even if the above-mentioned wear occurs on the valve contact surface, it is possible to prevent liquid from leaking into the inside of the sealing tube member through the gap between the peripheral wall portion and the valve contact surface.

It is desirable that the connecting wall close the space between the peripheral wall portion and the drive shaft.

In this case, liquid that has flowed inside the peripheral wall is less likely to flow out axially to the outside of the peripheral wall than the connecting wall, which reduces pressure loss caused by liquid flowing into unnecessary areas.

The connecting wall may be curved inward in the axial direction of the peripheral wall portion from the radially outer end toward the radially inner side.

In this case, the liquid that flows inside the peripheral wall is guided by the curved surface of the connecting wall, allowing it to flow smoothly in the direction of the valve hole.

The valve hole may be formed in an elongated hole shape extending circumferentially around the peripheral wall portion.

In this case, since the valve hole is an elongated hole extending in the circumferential direction, even if part of the valve hole is narrowed by the connecting wall, the elongated hole extending in the circumferential direction ensures a sufficient inflow area for liquid.

In the present invention, the connecting wall of the valve body extends radially inward from an axially inner position of the peripheral wall portion beyond the edge near one end of the valve hole, and the connecting wall forms a concave portion on the axial end side of the peripheral wall portion, and the end wall of the casing is shaped to fit into the concave portion. As a result, the inflow volume of liquid flowing into the peripheral wall portion of the valve body is reduced by the end wall of the casing, and each part of the liquid distribution system can be quickly controlled to the desired temperature.

FIG. 2 is a block diagram of an embodiment of a liquid dispensing system. FIG. 2 is a perspective view of a control valve according to an embodiment. FIG. 2 is an exploded perspective view of a control valve according to an embodiment. 4 is a cross-sectional view of the control valve according to the embodiment taken along line IV-IV in FIG. 2. 5 is a cross-sectional view of the control valve according to the embodiment taken along line VV in FIG. 4. FIG. 6 is an enlarged view of part VI in FIG. 5 . FIG. 7 is a cross-sectional view of the control valve according to the embodiment taken along line VII-VII in FIG. 2 . FIG. 4 is a perspective view showing a valve body and a cylindrical seal member according to the embodiment. FIG. 4 is a longitudinal sectional view of the cylindrical seal member according to the embodiment. FIG. 8 is a cross-sectional view similar to FIG. 7 of another embodiment.

Next, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a control valve is used in a liquid distribution system of a vehicle that distributes and supplies coolant for cooling the engine to a radiator and other devices.

Liquid Distribution System
FIG. 1 is a block diagram of a liquid dispensing system 1 .
1, the liquid distribution system 1 is mounted on a vehicle having at least an engine as a vehicle drive source. The vehicle may be a vehicle having only an engine, a hybrid vehicle, a plug-in hybrid vehicle, or the like.

The liquid distribution system 1 is composed of 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), which are connected by various flow paths 10-14.
The water pump 3, the engine 2, and the control valve 8 are connected in this order from upstream to downstream on a main flow path 10. In the main flow path 10, the operation of the water pump 3 causes the coolant (liquid) to pass through the engine 2 and the control valve 8 in this order.

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

The radiator 4 is connected to the radiator flow path 11. In the radiator flow path 11, heat exchange occurs between the coolant and the outside air in the radiator 4. The bypass flow path 12 returns the coolant that has passed through the control valve 8 to the upstream part 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 conditioning device. In the air conditioning flow path 13, heat exchange takes place in the heater core 6 between the coolant and the conditioned air flowing through the duct.

The EGR cooler 7 is connected to the EGR passage 14. In the EGR passage 14, heat exchange takes place between the coolant and the EGR gas in the EGR cooler 7.

In the liquid distribution 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]
Fig. 2 is a perspective view of the control valve 8, and Fig. 3 is an exploded perspective view of the control valve 8. Fig. 4 is a cross-sectional view of the control valve 8 taken along line IV-IV in Fig. 2, and Fig. 5 is a cross-sectional view of the control valve 8 taken along line V-V in Fig. 4. Fig. 6 is an enlarged view of a portion VI in Fig. 5, and Fig. 7 is a cross-sectional view of the control valve 8 taken along line VII-VII in Fig. 2.
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 has a cylindrical casing body 25 with a bottom and an end cover 26 attached to the end of the opening side of the casing body 25. The valve body 22 is rotatably accommodated inside the casing 21. An 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. 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 side facing the end wall 32, which is the bottom wall 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 of the case axial direction, and the side facing the end cover 26 with respect to the case peripheral wall 31 of the casing body 25 is referred to as the other end side of the case axial direction. 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 an outer shape that is roughly rectangular. A number 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 the mounting pieces 33.

The end cover 26 of the casing 21 has a boss 26c disposed at the axial center of the annular frame 26a. The boss 26c is supported by the frame 26a through a number of spokes 26b. A cylindrical sliding bearing 16 with a bottom is attached to the boss 26c. The opening of the end cover 26, surrounded by the frame 26a, the boss 26c, and the adjacent spokes 26b, serves as an inlet 17 for allowing the coolant to flow into the inside of the casing 21. The inlet 17 is connected to the downstream side of the engine 2 of the main flow passage 10 (see FIG. 1) of the liquid distribution system 1. The end cover 26 is formed of a resin material, similar to the casing body 25.

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

A radiator joint 42 is connected to the open end face 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).
Further, a seal mechanism 36 is provided at the radiator outlet 60. The seal mechanism 36 includes a cylindrical seal member 37, a biasing member 38, and seal members 39 and 40. One axial end of the cylindrical seal member 37 communicates with the inside of the radiator outlet 60 (the downstream side of 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 disposed 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 is connected to the radiator joint 42 (radiator flow path 11). When the temperature of the coolant flowing inside the casing 21 rises above a specified temperature, the thermostat 61 opens the fail opening and allows the coolant inside the casing 21 to flow out into the radiator flow path 11.

Near one end of the case peripheral wall 31 in the case axial direction, an EGR port 62 is formed adjacent to the housing of the thermostat 61. The EGR port 62 is formed in the case peripheral wall 31 by bulging outward in the case radial direction. The EGR port 62 is formed with an EGR outlet 63 that communicates with a portion of the housing of the thermostat 61 upstream of the thermostat 61. The EGR joint 52 is connected to the open end face of the EGR port 62. The EGR joint 52 connects between the EGR outlet 63 and the upstream end of the EGR flow passage 14 (see FIG. 1).

A bypass port 64 that bulges outward in the case radial direction is formed in the wall of the case peripheral wall 31 opposite the wall in which the radiator port 41 is formed. The bypass port 64 is formed with a bypass outlet 65 (outlet) that penetrates the bypass port 64 in the case radial direction. The bypass outlet 65 is formed in a position facing the radiator outlet 60, with the axis O1 of the casing 21 between them. The bypass outlet 65 is also formed in a position biased toward the other end of the case peripheral wall 31 in the case axial direction, similar to the radiator outlet 60.

A bypass joint 66 is connected to the open end face of the bypass port 64. The bypass joint 66 connects the bypass outlet 65 to the upstream end of the bypass flow passage 12 (see FIG. 1). The bypass outlet 65 is provided with a seal mechanism 36 similar to that provided in the radiator outlet 60. The seal tube member 37 of this seal mechanism 36 has one axial end communicating with the inside of the bypass outlet 65 (downstream of the bypass outlet 65) and the other axial end opened and closed by the valve body 22.

An air conditioning port 67 (see FIGS. 2 and 3) that bulges outward in the case radial direction is formed in a wall of the case peripheral wall 31 adjacent to one side of the wall in which the radiator port 41 is formed. An air conditioning outlet 68 that penetrates the air conditioning port 67 in the case radial direction is formed in the air conditioning port 67. An air conditioning joint 69 is connected to the open end face of the air conditioning port 67. The air conditioning joint 69 connects the air conditioning outlet 68 to the upstream end of the air conditioning flow path 13 (see FIG. 1). The air conditioning outlet 68 is provided with a seal mechanism 36 similar to those provided in the radiator outlet 60 and the bypass outlet 65. One axial end of the seal tube member 37 of this seal mechanism 36 communicates with the air conditioning outlet 68 (downstream of the air conditioning outlet 68), and the other axial end is opened and closed by the valve body 22.
In the following, the sealing cylinder member 37 that communicates with the air conditioning outlet 68 will be referred to as the first sealing cylinder member 37A, the sealing cylinder member 37 that communicates with the bypass outlet 65 will be referred to as the second sealing cylinder member 37B, and the sealing cylinder member 37 that communicates with the radiator outlet 60 will be referred to as the third sealing cylinder member 37C.

[Drive unit]
The drive unit 23 is attached to an end wall 32 of the casing body 25. As shown in Fig. 4, the end wall 32 has an end wall main body 32a that closes one end face of the case peripheral wall 31 in the case axial direction, and an enclosing wall 32b that protrudes from the outer circumferential edge of the end wall main body 32a toward one end in the case axial direction. A part of the drive unit 23 is housed inside the enclosing wall 32b, and in this state is fixed to the end wall 32 by bolting or the like.

The drive unit 23 includes a unit body 23A including a motor, a reduction mechanism, a control board, etc., and a unit case 23B that houses the unit body 23A. The output shaft 23Aa of the unit body 23A penetrates the unit case 23B and protrudes to the outside. A separate drive shaft 27 is integrally connected to the output shaft 23Aa. The drive shaft 27 is composed of a first shaft 27A made of resin and a second shaft 27B made of metal that are coaxially connected. The drive shaft 27 penetrates an axial hole 28 formed in the end wall body 32a of the casing 21 and is connected to the axial center of the valve body 22 described later. The drive shaft 27 is arranged coaxially with the axis O1 of the casing 21.

The thickness of the end wall body 32a of the casing 21 on the side facing the case peripheral wall 31 increases from the peripheral edge toward the central region (the region where the shaft hole 28 is formed). That is, a bulging portion 32a-1 that bulges toward the inside of the peripheral wall portion 44 of the valve body 22 is formed on the side of the end wall body 32a facing the case peripheral wall 31. The shaft hole 28 is formed so as to penetrate the thickest part of the end wall 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). In addition, an enlarged diameter groove 30 with an inner diameter larger than the inner peripheral surface of the other parts of the shaft hole 28 is formed on the edge of the shaft hole 28 on the valve body 22 side. A seal ring 35 is attached inside the enlarged diameter groove 30 in close sliding contact with the outer circumferential surface of the drive shaft 27 (second shaft 27B) to prevent leakage of coolant from inside the casing body 25 to the drive unit 23. The other end 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 disposed inside the casing 21. The valve body 22 includes a cylindrical peripheral wall portion 44, a connecting wall 45 extending radially inward from a position near one end of the peripheral wall portion 44 in the case axial direction, and a substantially cylindrical connecting tube portion 46 connected to the radially inner end of the connecting wall 45. The peripheral wall portion 44, the connecting wall 45, and the connecting tube portion 46 are integrally formed of a resin material. The connecting tube portion 46 is integrally connected to the drive shaft 27 (second shaft 27B). The peripheral wall portion 44 is formed with a valve hole 47 that can communicate with each of the above-mentioned outlets (air conditioning outlet 68, bypass outlet 65, and radiator outlet 60). Each valve hole 47 penetrates the peripheral wall portion 44 in the case radial direction.
Hereinafter, the valve hole 47 that can communicate with the air conditioning outlet 68 will be referred to as the first valve hole 47A, the valve hole 47 that can communicate with the bypass outlet 65 will be referred to as the second valve hole 47B, and the valve hole 47 that can communicate with the radiator outlet 60 will be referred to as the third valve hole 47C.

FIG. 8 is a perspective view showing the valve body 22 and each of the cylindrical seal members 37 (first cylindrical seal member 37A, second cylindrical seal member 37B, and third cylindrical seal member 37C) arranged around the peripheral region of the peripheral wall portion 44 of the valve body 22.
The first valve hole 47A is formed in a region on one end side of the peripheral wall portion 44 in the case axial direction (closer to one end portion of the peripheral wall portion 44 in the axial direction). The first valve hole 47A is formed in an elongated hole shape along the circumferential direction of the peripheral wall portion 44. When the valve body 22 is in a predetermined rotation range, the first valve hole 47A allows communication between the inner space of the peripheral wall portion 44 of the valve body 22 and the air conditioning outlet 68. The first valve hole 47A has a width along the axial direction of the peripheral wall portion 44 set to be narrower than the second valve hole 47B and the third valve hole 47C.

The second valve hole 47B is formed in two parts spaced apart in the circumferential direction in the region on the other end side of the peripheral wall portion 44 in the case axial direction (near the other end of the peripheral wall portion 44 in the axial direction). The third valve hole 47C is formed in two parts spaced apart in the circumferential direction in the region on the other end side of the peripheral wall portion 44 in the case axial direction (near the other end of the peripheral wall portion 44 in the axial direction). The second valve hole 47B and the third valve hole 47C are formed in a region on the peripheral wall portion 44 where they overlap with each other in the axial direction. The second valve hole 47B and the third valve hole 47C are formed in a region on the peripheral wall portion 44 that does not overlap with the first valve hole 47A in the axial direction (regions spaced apart in the axial direction). The second valve hole 47B and the third valve hole 47C can have any shape, such as a perfect circle, an oval, or a rectangle, but the width in the axial direction of the peripheral wall portion 44 of the third valve hole 47C, which can communicate with the radiator outlet 60, is wider than the second valve hole 47B.

Here, the connecting wall 45 of the valve body 22 described above extends radially inward from an axially inner position of the peripheral wall portion 44 beyond the edge of the first valve hole 47A closer to one axial end (closer to one axial end of the peripheral wall portion 44). In the region on the peripheral wall portion 44 where the first valve hole 47 does not exist, the outer peripheral end of the connecting wall 45 is directly connected to the inner peripheral surface of the peripheral wall portion 44 as shown in FIG. 4. In contrast, in the region on the peripheral wall portion 44 where the first valve hole 47 exists, as shown in FIG. 7, the connecting part 50 is connected to the edge 47Ae-1 closer to one end of the first valve hole 47A via a connecting part 50 recessed radially inward from the outer peripheral surface of the peripheral wall portion 44. The connecting part 50 extends radially inward from the edge 47Ae-1 closer to one end of the first valve hole 47A of the peripheral wall portion 44 in a stepped manner and toward the inside of the first valve hole 47A (the axial inner side of the peripheral wall portion 44). The outer peripheral end of the connecting wall 45 is connected to the end of the connecting part 50 in the extension direction.

In the valve body 22 of this embodiment, as described above, the outer peripheral edge of the connecting wall 45 is positioned axially inward of the edge 47Ae-1 near one end of the first valve hole 47A, thereby forming a concave portion 51 that opens to one axial end side of the peripheral wall portion 44. The depth of the outer peripheral edge of the concave portion 51 (depth from the axial end side of the peripheral wall portion 44) is deeper than the edge 47Ae-1 near one end of the first valve hole 47A. The bulge portion 32a-1 formed on the end wall 32 of the casing 21 fits into the concave portion 51. Since the concave portion 51 of the valve body 22 is particularly deep at the outer peripheral edge, the volume of the bulge portion 32a-1 on the casing 21 side that fits into the concave portion 51 is large.

4 and 7, the connecting wall 45 is curved inward in the axial direction from the radially outer end toward the radially inner side. In other words, the connecting wall 45 is formed so that the coolant flowing in from the inlet 17 on the other axial end side of the peripheral wall portion 44 flows smoothly along the curved surface of the connecting wall 45 toward the first valve hole 47A.
In addition, since the connecting wall 45 is a wall for connecting the peripheral wall portion 44 of the valve body 22 and the drive shaft 27, it is possible to form it in a spoke shape, but the connecting wall 45 in this embodiment is configured as a continuous wall with no gaps or openings so as to close the space between the peripheral wall portion 44 and the drive shaft 27.

[Sealing mechanism]
Next, a description will be given of the sealing mechanism 36 provided at each outlet (the bypass outlet 65, the radiator outlet 60, and the air conditioning outlet 68) and the structure of its surrounding area. Note that since the sealing mechanisms 36 arranged at each outlet have the same basic structure, the following will describe in detail the sealing mechanism 36 at the bypass outlet 65 and the structure of its surrounding area, and will omit a description of the sealing mechanisms 36 at the radiator outlet 60 and the air conditioning outlet 68 and the structure of their surrounding areas.

In the following description, the direction along the axis O2 (see FIG. 5) 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 (see FIG. 5) with respect to the bypass port 64 is referred to as the inner side, and the side away from the axis O1 with respect to the bypass port 64 is referred to as the outer side. In addition, 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 has a small diameter hole 65a adjacent to the inner surface of the casing 21, a medium diameter hole 65b connected to the small diameter hole 65a on the outside in the port axial direction, and a large diameter hole 65c connected to the medium diameter hole 65b on the outside in the port axial direction.

The bypass joint 66 has a joint tubular portion 53 arranged coaxially with the axis O2, and a joint flange portion 54 extending radially outward from the joint tubular portion 53. The joint flange portion 54 is placed on an end face of the bypass port 64 in the expanding direction, and is fixed to the bypass port 64 by bolt fastening or the like. The joint tubular portion 53 has a large diameter portion 53a fitted into the large diameter hole 65c of the bypass outlet 65, a small diameter portion 53b fitted into the medium diameter hole 65b of the bypass outlet 65, and a medium diameter portion 53c forming an annular seal accommodating portion 58 between the large diameter hole 65c of the bypass outlet 65 and the medium diameter portion 53c.
Further, an enlarged diameter groove 55 that continues to the inner end in the port axial direction is formed on the inner peripheral surface of the joint cylinder portion 53. A step portion 55a is provided at the outer end in the port axial direction of the enlarged diameter groove 55.

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

FIG. 9 is a vertical cross-sectional view of the cylindrical seal member 37.
The sealing tube member 37 has a peripheral wall extending coaxially with the axis O2. The peripheral wall of the sealing tube member 37 is formed in a multi-stage cylindrical shape in which the outer diameter is stepped down toward the outside in the port axial direction. Specifically, the peripheral wall of the sealing tube member 37 has a first tube portion 56 located on the outside in the port axial direction (one end side in the axial direction) and communicating with the downstream side of the bypass outlet 65, and a second tube portion 57 located on the inside in the port axial direction (the other end side in the axial direction) and having an inner diameter and an outer diameter larger than those of the first tube portion 56. As shown in FIG. 9, if the inner diameter dimension of the first tube portion 56 is R1, the inner diameter dimension of the second tube portion 57 is R2, the outer diameter dimension of the first tube portion 56 is R3, and the outer diameter dimension of the second tube portion 57 is R4, the inner diameters and outer diameters of the first tube portion 56 and the second tube portion 57 are set to satisfy R1<R2 and R3<R4.
The inner circumferential surfaces of the first cylindrical portion 56 and the second cylindrical portion 57 form an internal passage 90 that connects the outer end (one end) and the inner end (the other end) of the sealing cylindrical member 37 in the port axial direction.

As shown in FIG. 6, the sealing cylinder member 37 has a large-diameter second cylinder portion 57 slidably inserted into the inner circumferential surface of the small-diameter hole 65a of the bypass outlet 65. The inner end face of the second cylinder portion 57 in the port axial direction forms an annular valve sliding surface 59 (sliding surface) that slidably contacts the outer circumferential surface of the peripheral wall portion 44 of the valve body 22. In this embodiment, the valve sliding surface 59 is a continuous curved surface that follows the shape of the outer circumferential surface of the peripheral wall portion 44.

The outer peripheral surface of the first cylindrical portion 56 is connected to the outer peripheral surface of the second cylindrical portion 57 via a step surface 49. A gap Q1 is formed between the outer peripheral surface of the first cylindrical portion 56 of the sealing cylindrical member 37 and the inner peripheral surface of the medium diameter hole 65b of the bypass outlet 65, the gap Q1 being sandwiched between the step surface 49 of the sealing cylindrical member 37 and the end face of the small diameter portion 53b of the bypass joint 66. An annular seal member 39 such as an X packing or a Y packing is interposed in this gap Q1. The seal member 39 is in slidable contact with the outer peripheral surface of the first cylindrical portion 56 of the sealing cylindrical member 37 and the inner peripheral surface of the medium diameter hole 65b of the bypass outlet 65.
Incidentally, the hydraulic pressure of the coolant in the casing 21 is introduced into the space inside the gap Q1 in the port axial direction, sandwiching the seal member 39, through the gap between the small diameter hole 65a of the bypass outlet 65 and the second tubular portion 57 of the tubular seal member 37. The stepped surface 49 is formed in a direction opposite to the valve sliding surface 59 of the tubular seal member 37 in the port axial direction. The stepped surface 49 constitutes a pressure-receiving surface that receives the hydraulic pressure of the coolant in the casing 21 and is pressed inward in the port axial direction.
Further, an annular seal 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 to provide a liquid-tight seal therebetween.

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

In the cylindrical seal member 37, the area S1 of the step surface 49 and the area S2 of the valve sliding contact surface 59 are set so as to satisfy the following expressions (1) and (2).
S1<S2≦S1/k...(1)
α≦k<1 ... (2)
k: pressure reduction constant of the coolant flowing through the minute gap between the valve sliding surface 59 and the peripheral wall portion 44 of the valve body 22 α: lower limit of the pressure reduction constant determined by the physical properties of the coolant Note that the area S1 of the step surface 49 and the area S2 of the valve sliding surface 59 refer to the areas when projected in the port axial direction.

In formula (2), α is a standard value of the pressure reduction constant that is determined by the type of coolant, the usage environment (e.g., temperature), etc. For example, under normal usage conditions, in the case of water, α = 1/2. If the physical properties of the coolant used change, α changes to 1/3, etc.
Furthermore, the pressure reduction constant k in formula (2) is a standard value α (e.g., ½) when the valve contact 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. However, due to manufacturing errors or assembly errors of the cylindrical seal member 37, the gap between the outer circumferential portion of the valve contact surface 59 and the peripheral wall portion 44 may be slightly larger than the inner circumferential portion of the valve contact surface 59. In this case, the pressure reduction constant k in formula (2) gradually approaches k=1.

In this embodiment, assuming that there is a minute gap between the valve sliding surface 59 of the sealing tube member 37 and the outer peripheral surface of the peripheral wall portion 44 to allow sliding, the relationship between the areas S1, S2 of the step surface 49 and the valve sliding surface 59 is determined by equations (1) and (2).
That is, as described above, the pressure of the coolant inside the casing 21 acts as is on the step surface 49 of the cylindrical seal member 37. On the other hand, the pressure of the coolant inside the casing 21 does not act as is on the valve sliding contact surface 59. Specifically, the pressure of the coolant acts while decreasing as the coolant flows from the outer edge toward the inner edge in the port radial direction through the minute gap between the valve sliding contact surface 59 and the peripheral wall portion 44. At this time, the pressure of the coolant gradually decreases toward the inside in the port radial direction, and tries to push the cylindrical seal member 37 outward in the port axial direction.

As a result, a force obtained by multiplying the area S1 of the step surface 49 by the pressure P inside the casing 21 acts directly on the step surface 49 of the sealing cylinder member 37. On the other hand, a force obtained by multiplying the area S2 of the valve contact surface 59 by the pressure P inside the casing 21 and the pressure reduction constant k acts on the valve contact surface 59 of the sealing 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 the formula (1). Therefore, the relationship P×k×S2≦P×S1 also holds.
Therefore, the force F1 (F1 = P x S1) acting on the step surface 49 of the cylindrical seal member 37 in the pressing direction is greater than or equal to the force F2 (F2 = P x k x S2) acting on the valve sliding surface 59 of the cylindrical seal member 37 in the lifting direction. Therefore, in the control valve 8 of this embodiment, the gap between the cylindrical seal member 37 and the peripheral wall portion 44 can be sealed only by the relationship in the pressure of the coolant inside the casing 21.

In contrast, in this embodiment, as described above, the area S1 of the step surface 49 of the sealing cylinder member 37 is smaller than the area S2 of the valve sliding surface 59. Therefore, even if the pressure of the coolant in the casing 21 increases, the valve sliding surface 59 of the sealing 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 an increase in size and power of the drive unit 23 that rotates the valve body 22, and to prevent early wear of the sealing cylinder member 37 and the bushings of the drive unit.

In this manner, in this embodiment, the area S2 of the valve sliding surface 59 is set to be larger than the area S1 of the step surface 49, within a range in which the inward pressing force in the port axial direction acting on the sealing tube member 37 is not less than the outward lifting force in the port axial direction acting on the sealing tube member 37. Therefore, the gap between the sealing tube member 37 and the peripheral wall portion 44 can be sealed while preventing the sealing tube member 37 from being pressed against the peripheral wall portion 44 with excessive force.

[Valve body and sealing cylinder member]
The first valve hole 47A formed near one axial end of the peripheral wall portion 44 of the valve body 22 is formed in an elongated hole shape that is long in the circumferential direction of the peripheral wall portion 44, as described above. The first valve hole 47 opens and closes the first cylindrical seal member 37A by rotating the valve body 22. While the valve body 22 rotates with the first cylindrical seal member 37A closed by the peripheral wall portion 44, almost the entire surface of the valve sliding surface 59 of the first cylindrical seal member 37 slides in contact with the outer circumferential surface of the peripheral wall portion 44. In addition, while the valve body 22 rotates with the first sealing cylinder member 37A opened by the first valve hole 47A, a part of the valve sliding surface 59 of the first sealing cylinder member 37 slides in contact with an edge 47Ae-1 near one end of the first valve hole 47A in the axial direction and an edge 47Ae-2 near the other end (the end side opposite the edge 47Ae-1 near the one end across the first valve hole 47A).

In this embodiment, the edge 47Ae-1 near one end and the edge 47Ae-2 near the other end of the first valve hole 47A are set to contact the valve sliding surface 59 of the first seal cylinder member 37A at a radially outer position than the inner circumferential end 59e (see FIG. 9). In other words, the edge 47Ae-1 near one end and the edge 47Ae-2 near the other end do not move in the axial direction of the peripheral wall portion 44 to a position inside the inner circumferential end 59e of the valve sliding surface 59 (a position inside the inner circumferential surface of the valve sliding surface 59) when the valve body 22 rotates.

[Control valve operation]
Next, the operation of the above-mentioned control valve 8 will be described.
1 , in the main flow passage 10, the coolant delivered by the water pump 3 is heat exchanged in the engine 2 and then flows toward the control valve 8. The coolant that has passed through the engine 2 in the main flow passage 10 flows into a casing 21 of the control valve 8 through an inlet 17.

Of the coolant that flows into the casing 21 of the control valve 8, a portion of the coolant flows into the EGR outlet 63. The coolant that flows into the EGR outlet 63 passes through the EGR joint 52 and is supplied into the EGR flow path 14. The coolant that is supplied into the EGR flow path 14 undergoes heat exchange between the coolant and the EGR gas in the EGR cooler 7, and is then returned to the main flow path 10.

On the other hand, the coolant that flows into the casing 21 of the control valve 8 but does not flow into the EGR outlet 63 is distributed to each flow path 11 to 13 through one of the outlets (radiator outlet 60, bypass outlet 65, air conditioning outlet 68) opened by the valve body 22 depending on the rotational position of the valve body 22 in the casing 21.

In the control valve 8, to switch the communication pattern between the valve hole and the outlet, the valve body 22 is rotated around the axis O1 by the drive unit 23. 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 outlet are communicated in a communication pattern according to the stopping position of the valve body 22.

[Effects of the embodiment]
As described above, the control valve 8 of this embodiment is structured such that the connecting wall 45 of the valve body 22 extends radially inward from the axially inner position of the peripheral wall portion 44 beyond the edge 47Ae-1 near one end of the first valve hole 47A, and a recessed portion 51 with a deep radial outer area is formed on one axial end side of the peripheral wall portion 44. The bulging portion 32a-1 of the end wall 32 of the casing 21 fits inside this recessed portion 51. For this reason, when the control valve 8 of this embodiment is adopted, the end wall 32 of the casing 21 reduces the inflow volume of the cooling liquid flowing into the peripheral wall portion 44 of the valve body 22, and each part of the liquid distribution system 1 can be quickly controlled to a desired temperature. As a result, the friction of the engine 2, which is the driving source, can be reduced.

In addition, in the control valve 8 of this embodiment, the radially outer end of the connecting wall 45 of the valve body 22 is connected to the edge 47Ae-1 near one end of the first valve hole 47A via a connection portion 50 that is recessed radially inward from the outer circumferential surface of the peripheral wall portion 44. Therefore, the connecting wall 45 is connected to the peripheral wall portion 44 not only in the area where the first valve hole 47A is not open, but also in the area where the first valve hole 47A is open. Therefore, when this configuration is adopted, the rigidity of the joint between the connecting wall 45 and the peripheral wall portion 44 of the valve body 22 can be increased.

Furthermore, the control valve 8 of this embodiment is configured such that the edge 47Ae-1 near one end of the first valve hole 47A of the peripheral wall portion 44 and the edge 47Ae-2 near the other end abut at a radially outer position than the inner circumferential end 59e of the valve sliding surface 59 of the first seal cylinder member 37A. In particular, the edge 47Ae-1 near one end of the first valve hole 47A of the peripheral wall portion 44 is connected to the connecting wall 45 via a connecting portion 50 that is recessed radially inward from the outer circumferential surface of the peripheral wall portion 44. Therefore, while ensuring a deep recessed portion 51 in the radially outer region on the axial one end side of the peripheral wall portion 44, the edge 47Ae-1 near one end of the first valve hole 47A can be abutted at a radially outer position than the inner circumferential end 59e of the valve sliding surface 59 of the first seal cylinder member 37A. Therefore, with the above configuration, even if wear occurs on the valve sliding surface 59 of the first sealing cylinder member 37A due to use over time, the worn portion does not extend over the inner peripheral end portion 59e of the first sealing cylinder member 37A. Therefore, when the valve sliding surface 59 wears, it is possible to prevent liquid from leaking into the first sealing cylinder member 37A through the gap between the outer peripheral surface of the peripheral wall portion 44 and the valve sliding surface 59. Therefore, when this configuration is adopted, the seal life of the first sealing cylinder member 37A can be extended.

In addition, the control valve 8 of this embodiment is structured so that the connecting wall 45 of the valve body 22 closes the gap between the peripheral wall portion 44 and the drive shaft 27, making it difficult for the cooling liquid that has flowed inside the peripheral wall portion 44 to flow out to the outside of the connecting wall 45. Therefore, when the control valve 8 of this embodiment is used, the cooling liquid is less likely to flow into unnecessary areas, and the pressure loss of the cooling liquid flowing through the control valve 8 can be further reduced.

In addition, in the control valve 8 of this embodiment, the connecting wall 45 of the valve body 22 is curved from the radially outer end toward the inside of the peripheral wall portion 44 in the axial direction, so that the cooling liquid that flows into the inside of the peripheral wall portion 44 from the inlet 17 can flow smoothly along the curved surface of the connecting wall 45 in the direction of the first valve hole 47A.

Furthermore, in the control valve 8 of this embodiment, the first valve hole 47A of the valve body 22 is formed in an elongated hole shape that extends circumferentially along the peripheral wall portion 44. Therefore, even if a portion of the first valve hole 47A is narrowed by the connecting wall 45, the elongated hole shape extending in the circumferential direction can ensure a sufficient inflow area for the coolant.

The present invention is not limited to the above embodiment, and various design changes are possible without departing from the spirit of the present invention. For example, in the above embodiment, the cylindrical seal member 37 has a stepped cylindrical shape having the first cylindrical portion 56 and the second cylindrical portion 57, but the cylindrical seal member 37 may have a cylindrical shape without a stepped portion.
However, when the sealing tube member 37 has a stepped cylindrical shape having the first cylindrical portion 56 and the second cylindrical portion 57 as in the above embodiment, even if the valve hole on the valve body 22 side that opens and closes the sealing tube member 37 is not a long hole shape extending circumferentially, a sufficient amount of coolant can flow out to the corresponding outlet.

That is, the pressure loss of the cooling liquid flowing through the sealing tube member 37 is affected only by the opening area of the first tube portion 56, which has a smaller inner diameter than the second tube portion 57. Therefore, even if the valve hole formed on one axial end side of the peripheral wall portion 44 of the valve body 22 is not elongated and part of the valve hole is narrowed by the connecting wall 32, as long as the opening area of the valve hole is larger than the opening area of the internal passage of the first tube portion 56 of the sealing tube member 37, a sufficient amount of cooling liquid can be discharged to the corresponding outlet regardless of the opening area on the valve hole side. In this case, the connecting wall 32 can be offset toward the inside of the valve hole (inward in the case axial direction) while suppressing a decrease in the flow rate of the cooling liquid from the outlet.

In the above embodiment, the radially outer end of the connecting wall 45 of the valve body 22 is connected to the edge 47Ae-1 near one end of the first valve hole 47A via the connection part 50. However, as shown in Fig. 10, the radially outer end of the connecting wall 145 does not have to be connected to the edge 47Ae-1 of the first valve hole 47A so long as it extends radially inward from a position axially more inside than the edge 47Ae-1 near one end of the first valve hole 47A. In Fig. 10, the same reference numerals are used to designate parts common to the above embodiment.

In the above-described embodiment, the valve body 22 has a cylindrical peripheral wall portion 44, and a valve hole 47 that opens and closes the outlet of the sealing tube member 37 is formed on the outer circumferential surface of the cylindrical peripheral wall portion 44. However, the shape of the peripheral wall portion 44 of the valve body 22 is not limited to a cylindrical shape in which the diameter of the outer circumferential surface is constant in the axial direction. In other words, the shape of the peripheral wall portion 44 of the valve body 22 may be such that the diameter of the outer circumferential surface changes in the axial direction. In this case, the peripheral wall portion 44 of the valve body 22 can adopt various shapes, such as a spherical shape (a shape in which the diameter decreases from the center in the axial direction toward both ends), a shape in which multiple spherical shapes are connected in the axial direction, a tapered shape (a shape in which the diameter gradually changes from the first side to the second side in the axial direction), and a stepped shape (a shape in which the diameter gradually changes from the first side to the second side in the axial direction).

REFERENCE SIGNS LIST 1 liquid distribution system 8 control valve 17 inlet 21 casing 22 valve body 27 drive shaft 32 end wall 37 sealing cylinder member 44 peripheral wall portion 45 connecting wall 47A first valve hole (valve hole)
47Ae-1: Edge near one end 47Ae-2: Edge near the other end 50: Connection portion 51: Concave portion 59: Valve sliding surface 59e: Inner peripheral end 68: Air conditioning outlet (outlet)

Claims (5)

a casing having an inlet through which liquid flows in from the outside and an outlet through which the liquid that has flowed in is discharged to the outside;
a valve body rotatably disposed inside the casing, the valve body having a valve hole formed near one axial end of a peripheral wall portion;
a cylindrical seal member having one end communicating with the outlet port and the other end abutting against an outer circumferential surface of the peripheral wall portion and opened and closed by the valve hole;
a drive shaft disposed at an axial center position of the valve body and configured to transmit rotational power to the valve body,
the valve body has the peripheral wall portion and a connecting wall that connects the peripheral wall portion at a position near one end in the axial direction to the drive shaft,
the connecting wall extends radially inward from an axially inner position of the peripheral wall portion relative to an edge of the valve hole closer to the one end portion, and forms a recessed portion that opens toward the one axial end portion of the peripheral wall portion,
an end wall at one end of the casing in the axial direction bulges outwardly to enter the recessed portion ,
a connecting portion that is recessed radially inward from an outer circumferential surface of the peripheral wall portion and that is connected to an edge of the valve hole adjacent to the one end of the valve hole, the connecting portion being recessed radially inward from an outer circumferential surface of the peripheral wall portion . the cylindrical seal member has an annular valve sliding surface that slidably contacts an outer circumferential surface of the peripheral wall portion,
2. The control valve according to claim 1, wherein an edge of the valve hole near the one end and an opposite edge of the valve hole near the other end abut on a radially outer position of an inner circumferential end of the valve sliding surface of the cylindrical seal member. 3. The control valve according to claim 1 , wherein the connecting wall closes a gap between the peripheral wall portion and the drive shaft. 4. The control valve according to claim 3 , wherein the connecting wall is curved inwardly in the axial direction of the peripheral wall portion from a radially outer end portion toward a radially inner side. 5. The control valve according to claim 1, wherein the valve hole is formed in an elongated hole shape extending in a circumferential direction of the peripheral wall portion.

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