Valve device

A valve device includes: a valve having a ball surface having a convex spherical shape, and a first opening opened in the ball surface to allow fluid to pass through; and a seat having an annular shape and opposing the ball surface to be in sliding contact, the seat being pressed against the ball surface, the seat having a second opening to communicate with the first opening. The seat has a sealing surface in a sliding contact with the ball surface at a valve closed time when the ball surface and the second opening overlap with each other, and a seat contact surface in a sliding contact with an opening inner wall surface or an opening end surface of the first opening at a valve opened time when the first opening and the second opening overlap with each other.

CROSS REFERENCE TO RELATED APPLICATION

This application is the U.S. national phase of International Application No. PCT/JP2016/001718 filed Mar. 24, 2016 which designated the U.S. and claims priority to Japanese Patent Application No. 2015-77874 filed on Apr. 6, 2015 and Japanese Patent Application No. 2016-53310 filed on Mar. 17, 2016, the entire contents of each of which are hereby incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a valve device.

BACKGROUND ART

A conventional valve device is known, which includes an annular valve seat elastically supported by a casing, a ball valve having a ball surface shaped in a convex sphere surface in sliding contact with a sealing surface of the valve seat, and an elastic component which biases the valve seat against the ball surface of the ball valve (for example, Patent Literature 1).

The valve device controls the communication state between a first opening of the valve seat and a second opening of the ball valve by rotating the ball valve with a drive unit, so as to control the opening-and-closing operation of the ball valve.

However, in the conventional valve device, since the sealing surface of the valve seat and the ball surface of the ball valve are always in sliding contact to open and close, the sealing surface is worn out, such that the contact surface between the sealing surface and the ball surface increases. For this reason, the contact surface pressure of the sealing surface relative to the ball valve falls, and fluid may leak easily. In other words, the sealing performance for the fluid at the valve closed time of the ball valve cannot be secured over a long period of time.

Therefore, a valve device is required to achieve both of improvement in wear-resistant of the sealing surface of the seat and improvement in reliability of restricting fluid leak while the seat is pressed against the valve by the biasing force of the elastic component.

PRIOR ART LITERATURES

Patent Literature

SUMMARY OF INVENTION

The present disclosure is aimed to provide a valve device which can achieve both of improvement in wear-resistant of a sealing surface of a seat and improvement in reliability of restricting fluid leak.

According to an aspect of the present disclosure, a valve device performs at least opening and closing operation by both-way moving (hereafter, may be called as rotating) a valve in a rotational direction. The valve has a ball surface shaped in a convex spherical surface, and a first opening. The ball surface shaped in the convex spherical surface protrudes outward in a radial direction with a center corresponding to a predetermined rotation axis. The first opening of the valve is opened in the ball surface to allow fluid to pass through. The valve device has a seat having an annular shape and opposing the ball surface to be in sliding contact. The seat is pressed against the ball surface, and has a second opening capable of communicating with the first opening. The seat which is pressed against the valve has a sealing surface and a seat contact surface. The sealing surface is in sliding contact with the ball surface at a valve closed time when the ball surface and the second opening overlap with each other. The seat contact surface is in sliding contact with an opening inner wall surface or an opening end surface of the first opening at a valve opened time when the first opening and the second opening overlap with each other.

Thus, wear of the sealing surface of the seat can be reduced by separating the sealing surface in sliding contact with the ball surface at the valve closed time from the seat contact surface in sliding contact with the opening inner wall surface or the opening end surface of the first opening at the valve opened time. Thereby, fluid hardly leaks between the sealing surface and the ball surface, such that the seal performance for the fluid at the valve closed time can be secured for a long period of time. Therefore, both of improvement in wear-resistant of the sealing surface of the seat and improvement in reliability of restricting fluid leak can be achieved.

DESCRIPTION OF EMBODIMENTS

FIG. 1throughFIG. 7illustrate a valve device according to a first embodiment.

The valve device of this embodiment is a ball type rotary valve device mounted in a vehicle, and includes a spring3which elastically presses a valve seat2against a ball valve1. The valve device rotates the ball valve1to perform a flow control (open/close a passage and control the opening degree) or distribution control (switch the passage) of the engine cooling water (hereafter referred to cooling water) which is an example of fluid.

The valve device has one cooling-water inlet (inlet) and one or more (such as two or three) cooling-water outlets (outlet). In case where plural cooling-water outlets are provided, the cooling-water outlets have the same basic structure. Hereafter, an opening-and-closing part which is communicated to one cooling-water outlet is explained as an example. The valve device has a casing, and an electric actuator in addition to the spring3, the ball valve1shaped in multiple-surface sphere and the valve seat2shaped in ring.

The ball valve1includes a shaft (not shown) extending straightly in the rotation axis (CL) direction. As shown inFIG. 3, the ball valve1moves (rotates) both-way in a rotational direction shown in an arrow R with a center corresponding to the rotation axis (CL). The shaft is installed to pass through the ball valve1in the CL direction, and is connected with the ball valve1to be integrally rotatable. The shaft is supported to be rotatable relative to a housing4of the casing. The electric actuator has an electric motor which generates power driving the shaft of the ball valve1both-way (to rotate) in the rotational direction.

The casing includes a housing5, a plate6, a sleeve7in addition to the housing4. The casing may be constructed with the housing4which accommodates the ball valve1rotatably, and the sleeve7opposing to be contact with a sleeve regulation part (to be mentioned later) of the housing4, while the sleeve7is movable together with the valve seat2in a pressing load direction of the spring3. That is, the casing includes at least the housing4,5and the sleeve7.

Moreover, a seal part8such as a lip seal is arranged between the sleeve7and the housing5. A seal component9such as O ring is also arranged between the housing4and the housing5.

A cooling-water passage13,14is defined inside of the casing, and is located downstream of a seat opening12of the valve seat2in the flowing direction of cooling water. Further, the cooling-water passage13,14is communicated to the valve opening11of the ball valve1through the seat opening12. Moreover, a valve accommodation chamber is defined inside the casing to accommodate the ball valve1rotatably.

The ball valve1is made of, for example, synthetic resin (thermoplastic resin such as PPS), and has a surface in contact with at least the valve seat2, e.g., a smooth ball surface21shaped in convex sphere surface. The ball valve1is rotated by the electric actuator through the shaft. The ball valve1is shaped in an approximately cup form as an example. Moreover, the ball valve1rotates around the rotation axis (CL) (refer toFIG. 3).

The flowing direction of cooling water is not limited, while the cooling water is supplied from the inlet to the cooling-water passage10inside the ball valve1through the cup opening, as an example, for easy understanding. When the ball valve1opens the passage, the cooling water supplied to the cooling-water passage10is introduced to the outlet through the valve opening11, the seat opening12, and the cooling-water passage13,14.

The ball valve1has plural (such as two or three) ball surfaces21,22shaped in convex sphere surface protruding outward in a radial direction with a center corresponding to a predetermined rotation axis (center axis line of the shaft) CL, and is rotated by the electric actuator. The ball surface21corresponds to a first sliding surface to be in sliding contact with a sealing surface (second sliding surface)31of the valve seat2. The valve opening11is defined in the ball surface21to extend in the circumference direction of the ball valve1, and is able to communicate with the seat opening12. The ball surface22corresponds to a third sliding surface to be in sliding contact with a sealing surface (fourth sliding surface) of the other valve seat (not shown) different from the valve seat2. A valve opening15is defined in the ball surface22, and is able to communicate with a seat opening (not shown) corresponding to a fourth opening of the other valve seat.

The valve opening11is a first opening opened in the ball surface21to allow the cooling water to pass through. The valve opening11is shaped in an oblong hole extending in the circumference direction of the ball surface21. Moreover, a bridge16for reinforcement is provided in the valve opening11to connect the wall surfaces with each other through the opening. The valve opening15is a third opening shaped in a circle hole opened in the ball surface22to allow the cooling water to pass through. Moreover, a taper-shaped chamfering part54is formed at the opening peripheries of the valve opening11opposing in the CL direction of the ball valve1. The chamfering part54has a slope surface to gradually increase the opening area of the valve opening11as heading outward in the radial direction of the ball valve1.

The shaft is a driving shaft arranged to pass through an approximately central part of the valve accommodation chamber, and is supported through a bearing to be rotatable relative to the housing4. The electric actuator which drives the shaft may have a known configuration. In this disclosed embodiment, the electric actuator includes an electric motor converting electric power to a rotation torque, a deceleration mechanism (for example, mechanical reduction gear) which slows down the rotation output of the electric motor to increase the drive torque of the shaft, and a noncontact rotation angle sensor which detects the rotation angle of the shaft (namely, operation angle of the ball valve1).

The valve seat2is a ring disk board having the seat opening12through which cooling water passes at the central part. The seat opening12is the second opening to be communicated with the valve opening11. The valve seat2is made of synthetic resin (such as PTFE) in order to reduce the manufacturing cost and in order to improve the sealing property at a valve closed time and the sliding property at an operation time.

The valve seat2has an annular opposing part opposing the ball surface21to be in sliding contact, and the opposing part is forced onto the ball surface21by the elastic force of the spring3. The sealing surface31is formed in the opposing surface of the opposing part. Moreover, a surface (the upper side surface shown inFIG. 1andFIG. 2) of the valve seat2opposite from the sealing surface31is a seat opposite surface.

The valve seat2is supported by the housing4, and the housing4has means for supporting the valve seat2, such as the spring3, the housing4, the housing5, the plate6, and the sleeve7. The spring3is, for example, a compression coil spring arranged between the valve seat2and the housing5, and is attached in the compressed state. An end of the spring3is held at the plate6, and the other end is held at the seat holding part (to be mentioned later) of the sleeve7. The spring3is an elastic component which generates the elastic force elastically pressing the valve seat2against the ball valve1in the load direction. The elastic force of the spring3is set in a manner that the valve seat2is pressed onto the ball valve1with a predetermined pressing load.

The cooling-water inlet is located at the upstream end of the housing4. The cooling-water outlet is located at the downstream end of the housing4. The housing4has an opening through which the ball valve1is inserted, and the valve accommodation chamber for accommodating the ball valve1.

A case where the housing4is directly attached to an engine is explained. The housing4is directly attached to the engine (such as cylinder head), and the housing4is fixed to the engine. The opening of the housing4corresponds to the exit of the engine cooling water. The cooling water is supplied from the engine to the valve accommodation chamber inside the housing4(specifically, inner side of the ball valve1) through the opening of the housing4.

In case where the housing4is mounted independently from the engine, an inlet pipe is prepared for the housing4to introduce the cooling water from the engine to the valve accommodation chamber.

Moreover, an outlet pipe is fixed to the housing4to lead the cooling water to the exterior, after the flow rate is controlled in the valve device. The cooling water controlled in the flow rate with the valve device is introduced to a radiator, a heater core, and the like through a piping connected to the outlet pipe.

The housing5is a ring-shaped spacer fixed inside the housing4, and is produced separately from the housing4. The cooling-water passage14is formed inside the housing5. The housing5may be, for example, a part of the outlet pipe which leads the cooling water passing through the valve seat2to the cooling-water outlet, or another component (such as cylindrical object) different from the outlet pipe.

The inner circumference of the housing4,5, especially the housing5, has a sleeve regulation part (hereafter called as an inner circumference projection)51that is in contact with an engaging part (to be mentioned later) of the sleeve7to regulate the movement of the sleeve7toward the valve. Moreover, the sleeve7has the engaging part (hereafter called as an outer circumference projection)42opposing to be in contact with the inner circumference projection51, and the outer circumference projection42is engaged with the inner circumference projection51.

The plate6has a ring disk form and is arranged between the spring3and the housing5. The plate6is a metal spring seat holding the end of the spring3, and is produced separately from the housing4,5.

The sleeve7has the outer circumference projection42opposing to be in contact with or to be separated from the inner circumference projection51, and the seat holding part (the ring board43, the peripheral wall44) holding the valve seat2.

At the valve closed time of the ball valve1, the outer circumference projection42is spaced from the inner circumference projections51through an annular clearance S. Moreover, at a valve opened time of the ball valve1, the outer circumference projection42is in contact with and engaged with the inner circumference projection51.

The sleeve7is a cylinder object which supports the valve seat2at one end (near the ball valve1), and the other end is inserted into the housing5. The cooling-water passage13is formed inside the sleeve7, and introduces the cooling water passing through the seat opening12to the cooling-water passage14.

Specifically, the sleeve7is made of metal material such as stainless steel excellent in corrosiveness-proof, but is not limited. As means for supporting the valve seat2, the end of the sleeve7shaped in cylinder, which restrains the outer circumference surface of the valve seat2, integrally has a ring board43in pressure-contact with the seat opposite surface.

The valve device of this embodiment is formed to intentionally introduce the pressure of cooling water (hereafter referred to as water pressure), at the valve closed time of the ball valve1, to both sides (the sealing surface side and the seat opposite surface side) of the valve seat2. Specifically, a back pressure space45is defined near the seat opposite surface, to which the cooling water is introduced from the inlet to the inside of the valve device (namely, inside of the housing4).

Specifically, the back pressure space45is a space around the sleeve7where the spring3is arranged. In more details, the back pressure space45is a space surrounded by the plate6, the sleeve7, the ring board43and the passage wall in the housing4to be communicated to the outlet.

The back pressure space45is communicated to the space in the housing4which accommodates the ball valve1through a clearance between the housing4and the ring board43. The space which accommodates the ball valve1is always communicated to the inlet. For this reason, as shown in a dashed arrow W in the drawings, the cooling water is introduced to the back pressure space45from the engine through the inlet.

The valve seat2of this embodiment has the sealing surface31and the seat contact surface32.

When the ball valve1is rotated, the sealing surface31is in sliding contact with the ball surface21at the valve closed time of the ball valve1when the ball surface21and the seat opening12overlap with each other.

The seat contact surface32is formed on a surface different from the sealing surface31. At a valve opened time of the ball valve1when the valve opening11and the seat opening12overlap with each other, the seat contact surface32is in sliding contact with the inner wall surface17of the valve opening11.

Moreover, the valve device of this embodiment includes the spring3, the housing4,5, and the sleeve7.

The housing5has the inner circumference projection51in contact with the outer circumference projection42of the sleeve7to regulate movement of the sleeve7toward the valve. Moreover, the sleeve7has the outer circumference projection42opposing to be in contact with the inner circumference projection51, and the outer circumference projection42is engaged with the inner circumference projection51.

The seat holding part of the sleeve7is configured by the ring board43which fixes (junction or adhesion) the seat opposite surface of the valve seat2, and the cylindrical peripheral wall44which fixes (junction, adhesion, press-fit, or plastically deforming fixation) the outer circumference surface of the valve seat2. Namely, the sleeve7is connected with the valve seat2, and is able to move integrally with the valve seat2.

The sleeve7is a cylinder object opposing to be in contact with the inner circumference projection51of the housing5, and moveable in the pressing load direction of the spring3together with the valve seat2. The cooling-water passage13is defined inside the sleeve7, and communicates with the seat opening12and the cooling-water passage14.

The inner circumference projection51is formed on the inner circumference of the housing5, and the outer circumference projection42is formed on the outer circumference of the sleeve7. That is, the cylinder part of the sleeve7has a structure such as outer circumference recess portion recessed from the outer side inward in the radial direction than the outer circumference end surface of the outer circumference projection42, to which the inner circumference projection51is fitted.

Moreover, at the valve closed time of the ball valve1, since the ball surface21and the sealing surface31are in sliding contact, the sleeve7is moved away from the pressing load direction of the spring3. Thereby, a clearance is generated between the upper end surface of the inner circumference projection51and the lower end surface of the outer circumference projection42in the pressing load direction of the spring3, such that the inner circumference projection51and the outer circumference projection42are not in contact with each other. Moreover, at the valve closed time, the sleeve7can be displaced by the clearance in the pressing load direction of the spring3.

In contrast, at a valve opened time of the ball valve1, the ball surface21and the sealing surface31are not in the contact state. Since the valve seat2enters slightly inside the valve opening11, the sleeve7moves in the pressing load direction of the spring3. Thereby, the clearance between the upper end surface of the inner circumference projection51and the lower end surface of the outer circumference projection42is lost, such that the inner circumference projection51and the outer circumference projection42are in contact with each other. Therefore, the position of the valve seat2is fixed in the pressing load direction of the spring3.

As mentioned above, in the valve device of this embodiment, the valve seat2, which is pushed against the ball surface21of the ball valve1and the opening inner wall surface17of the valve opening11by the pressing load of the spring3, has the sealing surface31and the seat contact surface32.

At the valve closed time of the ball valve1, the valve seat2is pushed against the ball valve1by the pressing load of the spring3, such that the sealing surface31and the ball surface21of the valve seat2are in sliding contact. Namely, at the valve closed time of the ball valve1, the ball surface21and the sealing surface31are in the contact state, and the clearance between the ball surface21and the sealing surface31can be liquid-tightly sealed.

On the other hand, at a valve opened time of the ball valve1, the valve seat2is pushed against the ball valve1by the pressing load of the spring3, and the inner circumference projection51and the outer circumference projection42are in contact with each other. Since the sealing surface31of the valve seat2is fixed in the state of entering inside of the valve opening11, the seat contact surface32and the opening inner wall surface17of the valve opening11are in sliding contact. Namely, at a valve opened time of the ball valve1, the sealing surface31and the ball surface21are in the non-contact state.

The seat contact surface32that is in sliding contact with the opening inner wall surface17of the valve opening11at a valve opened time of the ball valve1can be produced separately from the sealing surface31that is in sliding contact with the ball surface21at the valve closed time of the ball valve1, such that wear of the sealing surface31of the valve seat2can be reduced. Thereby, cooling water becomes difficult to leak between the ball surface21and the sealing surfaces31. The seal performance for cooling water at the valve closed time of the ball valve1can be secured over a long period of time. Therefore, the wear-resistant improvement in the sealing surface31of the valve seat2and the improvement of reliability to prevent leak of cooling water become compatible.

Moreover, at a valve opened time of the ball valve1, while the sealing surface31of the valve seat2is forced onto the ball valve1by the pressing load of the spring3, the ball surface21and the sealing surface31are in the non-contact state. Therefore, wear of the sealing surface31can be reduced, and the contact surface area between the ball surface21and the sealing surface31does not increase.

Since the contact surface pressure of the sealing surface31over the ball valve1is secured, the cooling water becomes difficult to leak from the seal part of the ball surface21and the sealing surface31, and the seal performance for the cooling water at the valve closed time of the ball valve1is securable over a long period of time. Therefore, since a fixed contact surface pressure can be uniformly maintained irrespective to wear of the valve seat2, the wear-resistant improvement in the sealing surface31of the valve seat2, and the improvement of reliability to prevent leak of cooling water become compatible.

InFIG. 6, the vertical axis represents the average value [° C.] of the engine internal water temperature TW, and the horizontal axis represents the lapsed time Time [sec] after the engine is started. In addition, G represents a change in the leak flow rate of the cooling water of the first embodiment, and H represents a change in the leak flow rate of the cooling water of a comparative example (system without the valve device of the first embodiment).

InFIG. 7, the vertical axis represents a fuel efficiency improvement effect [%], and the horizontal axis represents a leakage flow rate [L/min] of the cooling water.

According to the valve device of this embodiment, at a valve opened time of the ball valve1, the seat contact surface32and the opening inner wall surface17are in contact with each other, and the ball surface21and the sealing surface31are made in the non-contact, such that wear of the sealing surface31can be controlled.

When such valve device is used for flow control of engine cooling water, as shown inFIG. 6andFIG. 7, the leak flow rate of the cooling water at the valve closed time of the ball valve1can be reduced from A (for example, 25-35 [L/min]) in the conventional example to 0 [L/min] according to the first embodiment, such that high seal performance can be maintained for a long period of time.

That is, if the seal performance is maintainable over a long period of time, the fuel efficiency improvement effect: α % or more can be attained to improve the reliability.

The fuel efficiency improvement effect: α % means that the fuel efficiency improves by α %, if the time period from the engine start to the warm-up completion becomes short by ΔT seconds, compared with the comparative example.

Moreover, the warm-up operation of the engine is performed, immediately after the engine is started, to raise the engine internal water temperature (TW) to a proper temperature (for example, internal water temperature: TW=80 [° C.]) while the operational status such as the engine rotation speed and the engine load is suppressed for a predetermined period of time. That is, the time period from the engine start to the warm-up completion means a period from when the engine is put in operation to when the engine internal water temperature is raised to the proper temperature.

FIG. 8andFIG. 9illustrate a valve device (according to a second embodiment). The same mark as the first embodiment represents the same configuration or function, and the explanation is omitted.

The valve device of this embodiment includes, similarly to the first embodiment, the ball valve1shaped in multiple-surface sphere, the valve seat2shaped in ring, the spring3, and the casing.

The casing includes at least the housing4,5and the cylindrical sleeve7.

The ball surface21of the ball valve1integrally has a ridge part52,53along a pair of opening peripheries extending in the rotational direction of the valve opening11. The ridge part52,53is a valve convex part projected outward in the radial direction than a ball reference surface23of the ball surface21.

The taper-shaped chamfering part54is formed along the opening periphery of the ridge part52,53adjacent to the valve opening11in the CL direction. The taper-shaped chamfering part55is formed along the opening periphery of the ridge part52,53on the side opposite from the valve opening11in the CL direction. The chamfering part54has a slope surface more gentle than that of the chamfering part55. The opening area of the valve opening11is gradually increased as heading outward in the radial outside of the ball valve1in the slope surface of the chamfering part54.

The taper-shaped chamfering part56is formed at the both ends of the ridge part52,53in the rotational direction. The chamfering part56has a slope surface inclined upward from the ball reference surface23toward the peak surface of the ridge part52,53.

The ball surface21has the ball reference surface23flush with the outer circumference surface (convex sphere surface other than the ridge part52,53) of the ball valve1. Moreover, the valve seat2has the ball contact surface24flush with the peak surface of the ridge part52,53of the ball valve1.

At the valve closed time of the ball valve1, the sealing surface31is in sliding contact with the ball reference surface23.

The ball contact surface24is shaped in the convex sphere surface protruding outward in the radial direction with the center corresponding to the rotation axis (CL) of the ball valve1, and is located at the position projected on the outer side in the radial direction than the ball reference surface23. The ball contact surface24is an opening end surface of the valve opening11, and is projected away from the pressing load direction of the spring3relative to the ball reference surface23.

At the valve closed time of the ball valve1, the sealing surface31of the valve seat2is pushed against the ball surface21by the elastic force of the spring3, and the annular sealing surface31is in sliding contact with the ball reference surface23of the ball surface21.

The annular seat contact surface33is defined on the outer side of the sealing surface31in the radial direction. At an opened time of the ball valve1, the seat contact surface33is pushed against the ball valve1by the elastic force of the spring3, and is in sliding contact with the ball contact surface24. The seat contact surface33is formed to surround the sealing surface31in the circumferential direction.

When closing the passage with the ball valve1, the valve seat2moves in the pressing load direction of the spring3, and the ball reference surface23and the sealing surface31are in sliding contact. At this time, the clearance between the upper end surface of the inner circumference projection51and the lower end surface of the outer circumference projection42becomes the narrowest.

At the valve closed time, the valve seat2and the sleeve7can displace by a predetermined distance in the pressing load direction of the spring3.

At the valve closed time, the sealing surface31of the valve seat2is forced on the ball valve1by the pressing load of the spring3, such that the ball reference surface23and the sealing surface31are in the contact state. Therefore, the clearance between the ball surface21and the sealing surface31can be liquid-tightly sealed.

In contrast, when opening the passage with the ball valve1, the valve seat2moves upward from the ball reference surface23through the chamfering part56onto the ball contact surface24. Therefore, the ball contact surface24and the seat contact surface33are in sliding contact, and the ball reference surface23and the sealing surface31are in the non-contact state. At this time, the sealing surface31is located on the inner side than the inner wall surface of the valve opening11.

Moreover, the ball contact surface24and the seat contact surface33are in contact with each other. For this reason, the position of the valve seat2is fixed in the pressing load direction of the spring3.

Therefore, in order to raise the wear resistance of the sealing surface31of the valve seat2, the sealing surface31in sliding contact with the ball reference surface23of the ball surface21at the valve closed time of the ball valve1is separated from the seat contact surface33in sliding contact with the ball contact surface24at a valve opened time of the ball valve1, such that wear of the sealing surface31of the valve seat2can be reduced.

As mentioned above, in the valve device of this embodiment, the same effect as the first embodiment is achieved.

FIG. 10andFIG. 11illustrate a ball type rotary valve device (according to a third embodiment). The same mark as the first and second embodiments represents the same configuration or function, and the explanation is omitted.

The housing5of this embodiment has an inner circumference projection51in contact with an outer circumference projection42of the sleeve7to regulate the movement of the sleeve7.

The sleeve7has the outer circumference projection42opposing to be in contact with the inner circumference projection51, and the outer circumference projection42is engaged with the inner circumference projection51.

The inner circumference projection51has a slope surface61inclined to the pressing load direction of the spring3, and the outer circumference projection42has a slope surface62inclined to the pressing load direction of the spring3.

The slope surface61is a cone surface in which the passage cross-section area of the cooling-water passage14gradually decreases from the upper end of the housing5toward the lower end.

The slope surface62is a cone surface in which the amount of projection of the outer circumference projection42gradually decreases from the upper end of the sleeve7toward the lower end.

In the valve device of this embodiment, the same effect as the first and second embodiments is achieved.

Since the opposing surfaces of the inner circumference projection51and the outer circumference projection42are inclined, the displacement of the valve seat2and the sleeve7in the horizontal direction (left-right direction) can be restrained. Further, at a valve opened time of the ball valve1, the ball surface21and the sealing surface31can be restricted from having the sliding contact due to the engine vibration or the vehicle vibration. Thereby, wear of the ball surface21and the sealing surface31can be controlled.

FIG. 12andFIG. 13illustrate a valve device (according to a fourth embodiment). The same mark as the first, second and third embodiments represents the same configuration or function, and the explanation is omitted.

The valve device of this embodiment includes the ball valve1shaped in multiple-surface sphere, the valve seat2shaped in ring, the spring3, and the casing, similarly to the first embodiment.

The casing includes at least the housing4,5and the cylindrical sleeve7.

The ball valve1has the ball surface21and the ball contact surface25.

The ball contact surface25is an opening end surface of the valve opening11, and is defined along the opening periphery of the valve opening11. At a valve opened time of the ball valve1, the seat contact surface35is in sliding contact with the ball contact surface25.

The taper-shaped chamfering part54is formed along the opening periphery adjacent to the valve opening in the CL direction of the ball valve1.

Moreover, the taper-shaped chamfering part58is formed at the both ends of the valve opening11in the rotational direction of the ball valve1. Each of the chamfering parts58has an arc shape along the opening periphery of the valve opening11, and has a slope surface inclined upward to the opening end of the valve opening11. That is, the chamfering part58is formed in the taper shape in a manner that the valve seat2moves smoothly upward from the valve opening11onto the ball surface21when closing the passage with the ball valve1.

The valve seat2has an annular seat recess portion34located on the outer side of the annular sealing surface31in the radial direction. The seat recess portion34is recessed away from the pressing load direction of the spring3.

An annular seat contact surface35is formed on the outer side of the seat recess portion34in the radial direction, and opposes the ball surface21to be in sliding contact. The seat contact surface35is forced on the ball surface21by the elastic force of the spring3.

The seat contact surface35is connected with the sealing surface31through an annular step part36. The seat contact surface35is formed to surround the circumference of the sealing surface31in the circumferential direction. The seat contact surface35is in sliding contact with the ball contact surface25at a valve opened time of the ball valve1, and is in a non-contact state relative to the ball surface21at the valve closed time of the ball valve1.

The position of the seat contact surface35at the valve closed time of the ball valve1is located upper than the position of the seat contact surface35at a valve opened time, with respect to a reference line SL shown in a single chain line in the drawing. The reference line SL represents the position of the ring board43which holds the valve seat2in practice. That is, at a valve opened time of the ball valve1, the ring board43is located lower than the reference line SL.

The sealing surface31is arranged on the inner side of the seat recess portion34in the radial direction. The sealing surface31is defined along the opening periphery of the seat opening12. The sealing surface31is projected in the pressing load direction of the spring3, compared with the seat contact surface35. The sealing surface31is in sliding contact with the ball surface21at the valve closed time of the ball valve1, and is in a non-contact state relative to the ball surface21and the ball contact surface25at a valve opened time of the ball valve1.

In the valve device, the housing5does not have an inner circumference projection, and the sleeve7does not have an outer circumference projection. Thereby, the positions of the valve seat2and the sleeve7are fixed on the lower side when the ball surface21is in contact with the seat contact surface35(in the valve opened state), compared with a case where the ball surface21is in contact with the sealing surface31(in the valve closed state).

Therefore, at a valve opened time, the valve seat2is fixed in the state where the sealing surface31enters inside of the valve opening11while the ball surface21regulates the movement of the valve seat2and the sleeve7. That is, the ball surface21functions as a seat regulation part in contact with the valve seat2to regulate the movement of the valve seat2and the sleeve7.

When closing the passage with the ball valve1, the sealing surface31moves onto the ball surface21, such that the valve seat2moves in the pressing load direction of the spring3. That is, the valve seat2moves in an arrow direction (upward) shown inFIG. 12 (b).

Moreover, at the valve closed time of the ball valve1, the sealing surface31is forced on the ball valve1by the pressing load of the spring3. Therefore, the ball surface21and the sealing surface31are in the contact state, and the clearance between the ball surface21and the sealing surface31is liquid-tightly sealed.

Moreover, at the valve closed time of the ball valve1, since the ball surface21and the sealing surface31are in contact with each other, the valve seat2and the ring board43of the sleeve7are fixed on the upper side, compared with the valve opened time.

In contrast, when the ball valve1is operated to open, the sealing surface31of the valve seat2enters the valve opening11through the chamfering part58from the ball surface21. The ball contact surface25and the seat contact surface35are in sliding contact with each other, and the ball surface21and the sealing surface31are in the non-contact state. At this time, the sealing surface31is located on the inner side than the inner wall surface of the valve opening11. Moreover, the ball contact surface25and the seat contact surface35are in contact with each other. For this reason, the position of the valve seat2is fixed in the pressing load direction of the spring3.

When the ball valve1is operated to close, since the sealing surface31of the valve seat2moves upward onto the ball surface21through the chamfering part58from the valve opening11, the ball surface21and the sealing surface31are in sliding contact with each other, and the ball contact surface25and the seat contact surface35are in the non-contact state.

Therefore, in order to raise the wear resistance of the sealing surface31, the sealing surface31in sliding contact with the ball surface21at the valve closed time of the ball valve1is separated from the seat contact surface35in sliding contact with the ball contact surface25at the valve opened time of the ball valve1, such that wear of the sealing surface31can be reduced.

As mentioned above, in the ball type rotary valve of this embodiment, the same effect as the first, second and third embodiments is generated.

The ball valve is used as an example of a rotating-type valve in the embodiment, but is not limited. For example, the present disclosure may be applied to a rotary valve with an outer circumference surface shaped in convex sphere surface.

In this embodiment, fluid (cooling water in the embodiment) flows from the inner side to the outer side of a rotating-type valve (ball valve in the embodiment) at a valve opened time, but fluid may flow in the reverse direction.

In this embodiment, the ball valve is rotated by an electric actuator, but the means for driving the ball valve is not limited.

In this embodiment, the sleeve and the valve seat are fixed by press-fitting, but the joint means is not limited. For example, adhesive and the like may be used as the joint means.

In this embodiment, the compression coil spring is used as an example of a spring. Alternatively, the other spring such as bellows having a spring function relative to a ball valve or rubber component may be used.

In this embodiment, the present disclosure is applied to the valve device which controls the engine cooling water. Alternatively, the present disclosure may be applied to a valve device which controls cooling water of a vehicle not having an engine.

In this embodiment, the present disclosure is applied to the valve device which controls liquid (such as cooling water), but the fluid is not limited to liquid. The present disclosure may be applied to a valve device which controls gas (gases).