VALVE DEVICE

Provided is a valve device in which a valve body can come into close contact with a valve seat to reliably close the valve even if a shaft moves slightly off-axis or tilted. In a valve device including: a housing 10 defining an upstream passage 12a and downstream passages 13a and 14a through which a fluid passes, and valve seats 11d and 11e interposed between the upstream passage and the downstream passages; a shaft 60 reciprocating along a predetermined axis S; and valve bodies 20 and 30 fixed to the shaft and seated on and separated from the valve seats, the valve seats 11d and 11e are formed into annular tapered surfaces forming a part of conical surfaces centered on the axis, and the valve bodies 20 and 30 are formed to include convex curved surfaces 22a and 32a that come into contact with the annular tapered surfaces when seated.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefits of Japanese application no. 2023-121078, filed on Jul. 25, 2023. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The disclosure relates to a valve device including a valve body that is seated on a valve seat to close the valve, and particularly relates to a valve device including a valve body fixed to a shaft that reciprocates linearly.

Description of Related Art

As a conventional valve device, there is a check valve which includes a housing (curved pipe, valve box) having an inflow path, an outflow path, and a planar valve seat interposed between the inflow path and the outflow path; a valve body integrally formed with a valve shaft that reciprocates within the housing; a flat plate-shaped packing member attached to the valve body so as to contact the valve seat when the valve is closed; and a spring body urging the valve body in the valve-closing direction (see, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2016-75357)).

In this check valve, the packing member is formed on a flat surface, and the valve seat is formed on a flat surface. Therefore, if the valve shaft is slightly tilted, the packing member may not come into close contact with the valve seat, making it impossible to reliably close the valve.

As another valve device, an electromagnetic control valve is known, which includes a housing having an intake port, an exhaust port, and a valve seat interposed between the intake port and the exhaust port; a shaft reciprocating within the housing; a valve member and a rubber member fixed to the end portion of the shaft; a compression spring urging the valve member in the valve-closing direction; and a solenoid that includes a movable iron core, a fixed iron core, and an electromagnetic coil fixed to the shaft (see, for example, Patent Document 2 (Japanese Patent Application Laid-Open No. 62-56679)).

In this electromagnetic control valve, the valve seat is formed as a flat surface perpendicular to the reciprocating direction of the shaft, and the rubber member is formed to include a flat surface facing the valve seat and an annular protrusion protruding from the flat surface. However, the top of the annular protrusion is located on a substantially flat surface, so if the shaft is slightly tilted, the rubber member may not come into close contact with the valve seat, making it impossible to reliably close the valve.

In view of the above circumstances, the disclosure provides a valve device in which the valve body can be brought into close contact with the valve seat to reliably close the valve even if the shaft moves slightly off-axis or tilted.

SUMMARY

A valve device of the disclosure includes: a housing that defines an upstream passage and a downstream passage through which a fluid passes, and a valve seat which is interposed between the upstream passage and the downstream passage; a shaft that reciprocates along a predetermined axis; and a valve body that is fixed to the shaft, and seated on and separated from the valve seat, in which the valve seat is formed into an annular tapered surface which forms a part of a conical surface centered on the axis, and the valve body is formed to include a convex curved surface which comes into contact with the annular tapered surface when seated on the valve seat.

In the above valve device, the convex curved surface may be formed to include a part of a spherical surface which has a center on the axis.

In the above valve device, the valve seat may be defined by a circular inner edge and a circular outer edge centered on the axis, the valve body may include an outer peripheral edge which has an outer diameter equal to or smaller than a diameter of the circular outer edge, and the convex curved surface may be formed over a predetermined range which extends inward in a radial direction from the outer peripheral edge.

In the above valve device, the valve body may include a valve base member fixed to the shaft, and an elastic sealing member fixed to the valve base member, and the convex curved surface may be formed on the elastic sealing member.

In the above valve device, the valve base member may include a hub portion fixed to the shaft, and an annular plate portion extending from an outer periphery of the hub portion in a radial direction perpendicular to the axis, and the elastic sealing member may be joined to cover the annular plate portion.

In the above valve device, the elastic sealing member and the hub portion may be formed to have the same thickness dimension in a direction of the axis.

In the above valve device, the valve base member may include an uneven surface at a joint interface of the elastic sealing member.

In the above valve device, the elastic sealing member may be molded to the valve base member.

In the above valve device, the valve body may be formed to be rotationally symmetrical around the axis and plane symmetrical with respect to a plane perpendicular to the axis.

In the above valve device, the downstream passage may include a first downstream passage and a second downstream passage which branch from the upstream passage, the valve seat may include a first valve seat facing the first downstream passage and a second valve seat facing the second downstream passage, and the valve body may include a first valve body corresponding to the first valve seat and a second valve body corresponding to the second valve seat, in which the first valve body and the second valve body are spaced apart from each other in a direction of the axis.

In the above valve device, the first valve body may be in an open state of being separated from the first valve seat in a state where the second valve body is in a closed state of being seated on the second valve seat, and the second valve body may be in an open state of being separated from the second valve seat in a state where the first valve body is in a closed state of being seated on the first valve seat.

The above valve device may further include a drive unit that drives the shaft.

In the above valve device, the drive unit may include a movable element to which the shaft is fixed, an excitation coil, and a stator which forms a magnetic path, and the shaft may be made of a non-magnetic material.

In the above valve device, the valve base member may be made of a non-magnetic material, and the elastic sealing member may be made of a rubber material.

In the above valve device, the first valve body and the second valve body may be fixed to the shaft by fitting, and the housing may include: a housing body that includes a joint surface which joins the drive unit, a first opening which is formed inside the joint surface and to which the first valve body is inserted from one side in the direction of the axis, the first valve seat and the second valve seat which are sequentially arranged in the direction of the axis following the first opening, and a second opening to which the second valve body is inserted from the other side in the direction of the axis; and a housing cover that is coupled to the housing body so as to close the second opening.

In the above valve device, the shaft may include a positioning portion that positions the second valve body in the direction of the axis.

According to the valve device having the above configuration, even if the shaft moves slightly off-axis or tilted, the valve body can be brought into close contact with the valve seat to reliably close the valve.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the disclosure will be described below with reference to the accompanying drawings.

The valve device of the disclosure is applied to, for example, a cooling water circulation system or the like of a vehicle to adjust the flow of cooling water as a fluid.

As shown inFIG.1toFIG.3, the valve device according to an embodiment includes a housing10, a first valve body20and a second valve body30as valve bodies, a sealing member40, and a drive unit U fixed to the housing10.

The housing10is made of a resin material or the like, and includes a housing body10aand a housing cover10b.

As shown inFIG.6andFIG.7, the housing body10aincludes a cylindrical portion11, an upstream pipe portion12, a first downstream pipe portion13, a second downstream pipe portion14, a flange portion15, and a cover coupling portion16.

The cylindrical portion11is formed into a substantially cylindrical shape centered on an axis S, and includes a side wall11a, a first opening11b, a second opening11c, a first valve seat11d, a second valve seat11e, a central chamber11f, a first working chamber11g, and a second working chamber11h.

The first opening11bis a circular hole centered on the axis S on the inside of a joint surface15aof the flange portion15so as to face the first working chamber11g, and is formed so that the first valve body20can be inserted from one side in the direction of the axis S. Then, the first opening11bis closed by joining the drive unit U with the sealing member40sandwiched therebetween.

The second opening11cis a circular hole centered on the axis S on the inside of the cover coupling portion16so as to face the second working chamber11h, and is formed so that the second valve body30can be inserted from the other side in the direction of the axis S. Then, after the second valve body30is assembled, the second opening11cis closed by coupling with the housing cover10b.

The first valve seat11dis a region on which the first valve body20is seated, and is formed into an annular tapered surface that forms a part of a conical surface centered on the axis S and widens toward the side of the first opening11b.

That is, as shown inFIG.8, the first valve seat11dis formed as a part of a conical surface that widens at an apex angle θ1 from an apex P1located near the central chamber11ftoward the side of the first working chamber11gon the axis S, and is defined by a circular inner edge11d1and a circular outer edge11d2.

Here, the apex angle θ1 is formed in a range of about 110 degrees to 120 degrees, for example, and is set to about 115 degrees here.

The second valve seat11eis a region on which the second valve body30is seated, and is formed into an annular tapered surface that forms a part of a conical surface centered on the axis S and widens toward the side of the second opening11c.

That is, as shown inFIG.9, the second valve seat11eis formed as a part of a conical surface that widens at an apex angle θ2 from an apex P2located near the central chamber11ftoward the side of the second working chamber11hon the axis S, and is defined by a circular inner edge11e1and a circular outer edge11e2.

Here, the apex angle θ2 is formed in a range of about 110 degrees to 120 degrees, for example, and is set to about 115 degrees here.

In this embodiment, the first valve seat11dand the second valve seat11eare formed to be plane symmetrical with respect to a plane perpendicular to the axis S.

The central chamber11fis formed between the first valve seat11dand the second valve seat11ein the direction of the axis S, communicates with an upstream passage12adefined by the upstream pipe portion12, and also functions as an upstream passage located upstream of the first valve seat11dand the second valve seat11e.

The first working chamber11gis formed downstream of the first valve seat11d, is a region in which the first valve body20reciprocates in the direction of the axis S, communicates with a first downstream passage13adefined by the first downstream pipe portion13, and also functions as a first downstream passage located downstream of the first valve seat11d.

The second working chamber11his formed downstream of the second valve seat11e, is a region in which the second valve body30reciprocates in the direction of the axis S, communicates with a second downstream passage14adefined by the second downstream pipe portion14, and also functions as a second downstream passage located downstream of the second valve seat11e.

The upstream pipe portion12is a region to which a fluid inlet pipe of the applicable object (here, an inlet pipe forming a part of the cooling water circulation system) is connected, and defines the upstream passage12athat has a circular cross section centered on an axis L1perpendicular to the axis S.

The first downstream pipe portion13is a region to which a fluid outlet pipe of the applicable object (here, an outlet pipe forming a part of the cooling water circulation system) is connected, and defines the first downstream passage13athat has a circular cross section centered on an axis L2perpendicular to the axis S.

The second downstream pipe portion14is a region to which another fluid outlet pipe of the applicable object (here, another outlet pipe forming a part of the cooling water circulation system) is connected, and defines the second downstream passage14athat has a circular cross section centered on an axis L3perpendicular to the axis S.

The flange portion15is a region where the drive unit U is joined and fixed, and is formed in a substantially rectangular outline around the first opening11b. The flange portion15includes the joint surface15athat forms a flat surface perpendicular to the axis S, an annular groove15binto which the sealing member40is fitted, a positioning protrusion15cthat protrudes from the joint surface15ain the direction of the axis S, and four female screw holes15dinto which fastening screws b are screwed.

The cover coupling portion16is a region where the housing cover10bis coupled, and includes an annular groove16acentered on the axis S around the second opening11c, and an annular joint surface16baround the annular groove16a.

The housing cover10bis coupled to the cover coupling portion16to close the second working chamber11h, and includes a disc-shaped lid portion10b1that fits into the second opening11c, an annular protrusion10b2that fits into the annular groove16a, and an annular joint surface10b3that joins the annular joint surface16b.

Then, when assembling the valve device, after the second valve body30is fitted and fixed to the shaft60of the drive unit U, the housing cover10bis fitted to the cover coupling portion16of the housing body10a, and is coupled by adhesion, welding or the like, as necessary.

As shown inFIG.10toFIG.12, the first valve body20includes a valve base member21that is fitted and fixed to a predetermined position of the shaft60of the drive unit U and is formed using a metal material such as stainless steel or a resin material, and an elastic sealing member22that is molded to cover the valve base member21.

The valve base member21is formed by a hub portion21afixed to the shaft60, and an annular plate portion21bextending in a radial direction perpendicular to the axis S from the outer periphery of the hub portion21a.

The hub portion21ais formed into a cylindrical shape defining a fitting hole21a1centered on the axis S. The annular plate portion21bincludes a plurality of annular protrusions21b1concentrically centered on the axis S on both sides in the direction of the axis S. Then, uneven surfaces are defined on both sides of the valve base member21by the tops P and the troughs V defined by the plurality of annular protrusions21b1.

The elastic sealing member22is joined using a rubber material or the like so as to cover the annular plate portion21bof the valve base member21, that is, molded to the valve base member21so as to be fixed to the valve base member21via a region including the uneven surfaces of the annular plate portion21b.

Then, the elastic sealing member22is formed to include a convex curved surface22athat is convex outward on both sides in the direction of the axis S, an annular flat surface22b, and an outer peripheral edge22cthat forms a cylindrical surface.

Here, the convex curved surface22ais a curved surface having a predetermined curvature, and is formed to have a center C1on the axis S and include a part of a spherical surface Sp1having a radius R1, as shown inFIG.10, for example. Further, the convex curved surface22ais formed to extend over a predetermined range from the outer peripheral edge22ctoward the inside in the radial direction, here, as shown inFIG.12, to the inside in the radial direction beyond the circular inner edge11d1of the first valve seat11d.

The flat surface22bis formed at the same height position as the height dimension of the hub portion21aof the valve base member21in the direction of the axis S.

The outer peripheral edge22cis formed to have an outer diameter equal to or smaller than the diameter (diameter perpendicular to the axis S) of the circular outer edge11d2of the first valve seat11d. That is, the outer diameter dimension of the first valve body20is formed to be the same as or smaller than the outer diameter dimension of the first valve seat11d.

In the first valve body20having the above configuration, the convex curved surface22aof the elastic sealing member22is in close contact with the first valve seat11dat the valve-closed position. That is, the first valve body20is separated from the first valve seat11dand opens the valve at the rest position shown inFIG.15, and is seated on the first valve seat11dand closes the valve at the operating position shown inFIG.16.

Here, since the first valve body20is formed to include the convex curved surface22athat comes into contact with the annular tapered surface as the first valve seat11d, even if the first valve body20is seated on the first valve seat11dwith the shaft60tilted or off-axis, as indicated by the one-dot chain line and the two-dot chain line inFIG.13, the convex curved surface22ais reliably in close contact with the annular tapered surface to ensure airtightness.

In particular, since the convex curved surface22ais formed to include a part of the spherical surface having the center C1on the axis S, even if the first valve body20is seated with the shaft60tilted, close contact can be ensured to close the valve.

Furthermore, since the first valve body20is formed to have an outer diameter equal to or smaller than the diameter of the circular outer edge11d2of the first valve seat11d, even if the first valve body20is seated with the shaft60tilted, the outer peripheral edge22cof the first valve body20does not ride on the outside of the first valve seat11d, and close contact can be ensured to close the valve.

Moreover, since the first valve body20is fixed by joining the elastic sealing member22to the valve base member21via the region including the uneven surfaces, compared to a case of simply joining to a flat surface, the adhesion surface increases, and the mechanical bonding strength can be increased due to an anchor effect or the like.

Further, the elastic sealing member22and the hub portion21aare formed to have the same thickness dimension in the direction of the axis S. That is, since the outer contour of the first valve body20is formed as a continuous integral surface, the bonding strength therebetween can be increased compared to a configuration having a discontinuous step, and even if the shaft60is tilted, the region inside the convex curved surface22adoes not interfere with the first valve seat11d, and the valve-closing operation can be performed reliably while achieving thinness and size reduction.

Furthermore, the first valve body20is formed to be rotationally symmetrical around the axis S and plane symmetrical with respect to a plane perpendicular to the axis S. Therefore, the first valve body20has no directionality with respect to the first valve seat11d, and can be assembled so that either one of the convex curved surfaces22aon both sides faces the first valve seat11d, which facilitates the assembly work.

As shown inFIG.10toFIG.12, the second valve body30is fitted and fixed at a position where the second valve body30abuts against a positioning portion61of the shaft60of the drive unit U, and includes a valve base member31that is formed using a metal material such as stainless steel or a resin material, and an elastic sealing member32that is molded to cover the valve base member31.

The valve base member31is formed by a hub portion31afixed to the shaft60, and an annular plate portion31bextending in the radial direction perpendicular to the axis S from the outer periphery of the hub portion31a.

The hub portion31ais formed into a cylindrical shape defining a fitting hole31a1centered on the axis S. The annular plate portion31bincludes a plurality of annular protrusions31b1concentrically centered on the axis S on both sides in the direction of the axis S. Then, uneven surfaces are defined on both sides of the valve base member31by the tops P and the troughs V defined by the plurality of annular protrusions31b1.

The elastic sealing member32is joined using a rubber material or the like so as to cover the annular plate portion31bof the valve base member31, that is, molded to the valve base member31so as to be fixed to the valve base member31via a region including the uneven surfaces of the annular plate portion31b.

Then, the elastic sealing member32is formed to include a convex curved surface32athat is convex outward on both sides in the direction of the axis S, an annular flat surface32b, and an outer peripheral edge32cthat forms a cylindrical surface.

Here, the convex curved surface32ais a curved surface having a predetermined curvature, and is formed to have a center C2on the axis S and include a part of a spherical surface Sp2having a radius R2, as shown inFIG.10, for example. Further, the convex curved surface32ais formed to extend over a predetermined range from the outer peripheral edge32ctoward the inside in the radial direction, here, as shown inFIG.12, to the inside in the radial direction beyond the circular inner edge11e1of the second valve seat11e.

The flat surface32bis formed at the same height position as the height dimension of the hub portion31aof the valve base member31in the direction of the axis S.

The outer peripheral edge32cis formed to have an outer diameter equal to or smaller than the diameter (diameter perpendicular to the axis S) of the circular outer edge11e2of the second valve seat11e. That is, the outer diameter dimension of the second valve body30is formed to be the same as or smaller than the outer diameter dimension of the second valve seat11e.

In the second valve body30having the above configuration, the convex curved surface32aof the elastic sealing member32is in close contact with the second valve seat11eat the valve-closed position. That is, the second valve body30is seated on the second valve seat11eand closes the valve at the rest position shown inFIG.15, and is separated from the first valve seat11dand opens the valve at the operating position shown inFIG.16.

Here, since the second valve body30is formed to include the convex curved surface32athat comes into contact with the annular tapered surface as the second valve seat11e, even if the second valve body30is seated on the second valve seat11ewith the shaft60tilted or off-axis, as indicated by the one-dot chain line and the two-dot chain line inFIG.14, the convex curved surface32ais reliably in close contact with the annular tapered surface to ensure airtightness.

In particular, since the convex curved surface32ais formed to include a part of the spherical surface having the center C2on the axis S, even if the second valve body30is seated with the shaft60tilted, close contact can be ensured to close the valve.

Furthermore, since the second valve body30is formed to have an outer diameter equal to or smaller than the diameter of the circular outer edge11e2of the second valve seat11e, even if the second valve body30is seated with the shaft60tilted, the outer peripheral edge32cof the second valve body30does not ride on the outside of the second valve seat11e, and close contact can be ensured to close the valve.

Moreover, since the second valve body30is fixed by joining the elastic sealing member32to the valve base member31via the region including the uneven surfaces, compared to a case of simply joining to a flat surface, the adhesion surface increases, and the mechanical bonding strength can be increased due to an anchor effect or the like.

Further, the elastic sealing member32and the hub portion31aare formed to have the same thickness dimension in the direction of the axis S. That is, since the outer contour of the second valve body30is formed as a continuous integral surface, the bonding strength therebetween can be increased compared to a configuration having a discontinuous step, and even if the shaft60is tilted, the region inside the convex curved surface32adoes not interfere with the second valve seat11e, and the valve-closing operation can be performed reliably while achieving thinness and size reduction.

Furthermore, the second valve body30is formed to be rotationally symmetrical around the axis S and plane symmetrical with respect to a plane perpendicular to the axis S. Therefore, the second valve body30has no directionality with respect to the second valve seat11e, and can be assembled so that either one of the convex curved surfaces32aon both sides faces the second valve seat11e, which facilitates the assembly work.

Here, as described above, the first valve body20and the second valve body30are formed by the valve base members21and31having the same structure and form, and the elastic sealing members22and32having the same structure and form. That is to say, since the parts serving as the first valve body20and the second valve body30have the same shape (form), compared to a case where separate parts are used, management man-hours can be reduced and costs can be reduced.

If the first valve body and the second valve body have convex curved surfaces, they do not need to be the same part, and may be formed in different forms depending on the specifications of the first valve seat and the second valve seat, which form the annular tapered surfaces of the valve device.

As described above, the first valve body20and the second valve body30are arranged apart from each other in the direction of the axis S with respect to the shaft60, and due to the reciprocating movement of the shaft60, the first valve body20reciprocates within the first working chamber11gto be seated on and separated from the first valve seat11d, and the second valve body30reciprocates within the second working chamber11hto be seated on and separated from the second valve seat11e.

The sealing member40is formed into a disc shape using an elastically deformable thin film rubber material, and includes an annular fitting portion41, a central connecting portion42, and a communication hole43, as shown inFIG.3.

The communication hole43is formed in a size that does not allow foreign matter to pass through, and contributes to a pressure regulation effect as a ventilation hole.

Then, the sealing member40is connected by passing the shaft60of the drive unit U through the central connecting portion42, the annular fitting portion41is fitted into the annular groove15bof the housing10, and the sealing member40is held by joining a flat yoke100of the drive unit U.

In this assembled state, the sealing member40performs a sealing function at the joint interface between the housing10and the drive unit U, and is elastically deformed to move integrally with the shaft60and prevents foreign matter in the fluid from entering the side of the drive unit U. In addition, the sealing member40provides a pressure regulation effect through the communication hole43when elastically deformed so as not to inhibit the movement of the shaft60.

As shown inFIG.3andFIG.4, the drive unit U includes a movable element50, the shaft60, a first inner yoke70, a second inner yoke80, a cylindrical yoke90and a flat yoke100, an urging spring110, a coil module120, a cylindrical member130, and a sealing member Sr.

In addition, the coil module120includes a bobbin121, an excitation coil122, and a molded portion123in which the bobbin121and the coil122are embedded.

Further, the first inner yoke70, the second inner yoke80, the cylindrical yoke90, and the flat yoke100function as a stator that forms a magnetic path.

The movable element50functions as a magnetic path for passing lines of magnetic force and also functions as a movable iron core that moves in the direction of the axis S when the coil122is energized, and is formed into a cylindrical shape by machining or forging using free-cutting steel (SUM) or the like. As shown inFIG.4andFIG.5, the movable element50includes an outer peripheral surface51, a fitting hole52, a spring receiving portion53, a convex portion54, and an annular end surface55.

The outer peripheral surface51is formed as a cylindrical surface centered on the axis S, and is slidably in contact with the inner wall of the cylindrical member130.

The fitting hole52is a through hole centered on the axis S and is a region into which one end side region of the shaft60is press-fitted. The fitting hole52is formed to have an inner diameter slightly smaller than the outer diameter dimension of the shaft60.

The spring receiving portion53is formed into a circular concave portion centered on the axis S, receives one end portion111of the urging spring110, and positions the one end portion111in a direction perpendicular to the axis S.

The convex portion54is formed into a truncated cone shape, and is formed to fit into a concave portion83of the second inner yoke80in a non-contact manner.

The annular end surface55is formed as a flat surface perpendicular to the axis S, and faces an annular end surface84of the second inner yoke80in the direction of the axis S.

In addition, in order to make the movement of the movable element50smooth, for example, a slot extending in the direction of the axis S may be formed on the outer peripheral surface so as to adjust the front and rear pressures when the movable element50moves.

The shaft60is formed into a long columnar shape in the direction of the axis S using a non-magnetic material, for example, a metal material such as stainless steel or a resin material, and includes the positioning portion61near the other end side.

As shown inFIG.3,FIG.4, andFIG.10, the positioning portion61is formed into a brim shape that protrudes in the radial direction, and abuts against and positions the second valve body30in the direction of the axis S.

By providing the positioning portion61in this way, when the second valve body30is fitted and fixed to the shaft60inside the housing body10a, the second valve body30can be easily positioned at a predetermined position on the shaft60simply by abutting against the positioning portion61.

Then, the shaft60is fixed to the movable element50by fitting one end side region into the fitting hole52. Further, the central connecting portion42of the sealing member40is connected to the shaft60approximately at the center in the direction of the axis S, the first valve body20is fixed by fitting at a position closer to the other end (free end) side than the center in the direction of the axis S, and the second valve body30is fixed by fitting so as to abut against the positioning portion61on the other end side.

Then, the shaft60reciprocates in the direction of the axis S integrally with the movable element50, the first valve body20, and the second valve body30.

The first inner yoke70is formed by machining or forging using soft iron or the like, and functions as a magnetic path for passing lines of magnetic force. As shown inFIG.4andFIG.5, the first inner yoke70is formed into a cylindrical shape, and includes a first outer peripheral surface71, an inner peripheral surface72, and a first annular brim portion73.

The first outer peripheral surface71is formed as a cylindrical surface centered on the axis S, and is formed to be fitted into the inner peripheral surface91aof the small-diameter cylindrical portion91of the cylindrical yoke90and fitted into the bobbin121of the coil module120.

The inner peripheral surface72is formed as a cylindrical surface centered on the axis S, and is formed so that the cylindrical member130is fitted therein.

The first annular brim portion73is formed into a disc shape that protrudes in the radial direction perpendicular to the axis S from the first outer peripheral surface71, and includes an annular flat surface73aand an annular tapered surface73b.

The annular flat surface73ais a flat surface perpendicular to the axis S, and is joined to an annular joint surface94aof the cylindrical yoke90in the direction of the axis S.

The annular tapered surface73bis formed on the side opposite to the annular flat surface73a, and is formed to widen toward the annular joint surface94aof the cylindrical yoke90.

The second inner yoke80is formed by machining or forging using soft iron or the like, and functions as a magnetic path for passing lines of magnetic force and also functions as a fixed iron core that attracts the movable element50when the coil122is energized. As shown inFIG.4andFIG.5, the second inner yoke80is formed into a cylindrical shape, and includes a second outer peripheral surface81, a second annular brim portion82, a concave portion83, an annular end surface84, a spring housing concave portion85, and a guide hole86.

The second outer peripheral surface81is formed as a cylindrical surface centered on the axis S, and is formed to be fitted into the bobbin121of the coil module120via the cylindrical member130and fitted into the fitting hole103of the flat yoke100.

The second annular brim portion82is formed into a disc shape that protrudes in the radial direction perpendicular to the axis S from the second outer peripheral surface81, and includes an annular flat surface82aand an annular tapered surface82b.

The annular flat surface82ais a flat surface perpendicular to the axis S, and is joined to the annular joint surface101aof the flat yoke100in the direction of the axis S.

The annular tapered surface82bis formed on the side opposite to the annular flat surface82a, and is formed to widen toward the annular joint surface101aof the flat yoke100.

The concave portion83is formed into a truncated cone shape, and is formed to receive the convex portion54of the movable element50in a non-contact manner in the direction of the axis S.

The annular end surface84is formed as a flat surface perpendicular to the axis S, and faces the annular end surface55of the movable element50in the direction of the axis S.

The spring housing concave portion85is formed to have a smaller diameter than the concave portion83and receives the urging spring110, and includes a spring receiving portion85athat receives the other end portion112of the urging spring110.

The guide hole86is formed as a cylindrical hole centered on the axis S, and guides the shaft60slidably in the direction of the axis S.

The cylindrical yoke90is a press-molded product that is press-formed (deep-drawn) into a bottomed cylindrical shape using a metal plate such as soft iron having a predetermined thickness so as to function as a magnetic path for passing lines of magnetic force. As shown inFIG.1,FIG.4, andFIG.5, the cylindrical yoke90includes a small-diameter cylindrical portion91, a bottom wall92, a large-diameter cylindrical portion93, an annular flat plate portion94, a flange portion95, and a cutout portion96.

The small-diameter cylindrical portion91defines the inner peripheral surface91acentered on the axis S. The first outer peripheral surface71of the first inner yoke70is fitted into the inner peripheral surface91a. That is, the first inner yoke70is joined and fixed to the cylindrical yoke90in the radial direction perpendicular to the axis S via the inner peripheral surface91aof the small-diameter cylindrical portion91.

The bottom wall92is formed continuously with the end portion of the small-diameter cylindrical portion91in the direction of the axis S, and is arranged without contacting the cylindrical member130.

The large-diameter cylindrical portion93defines an inner peripheral surface93acentered on the axis S. The molded portion123of the coil module120is fitted into the inner peripheral surface93a.

The annular flat plate portion94is formed continuously in the boundary region between the small-diameter cylindrical portion91and the large-diameter cylindrical portion93, and defines the annular joint surface94ato which the annular flat surface73aof the first inner yoke70is joined in the direction of the axis S.

The flange portion95is formed into a substantially rectangular shape continuously from the end portion of the large-diameter cylindrical portion93, and includes four circular holes95athrough which the fastening screws b pass. Then, in the assembled state, the flange portion95is joined to the flat yoke100to form a magnetic path.

The cutout portion96is formed to expose a connector123aof the coil module120to the outside.

The flat yoke100is punched and bent using a metal plate such as soft iron having a predetermined thickness so as to be joined to the open end of the cylindrical yoke90and function as a magnetic path for passing lines of magnetic force. As shown inFIG.4andFIG.5, the flat yoke100includes a substantially rectangular flat plate portion101, an attachment portion102bent from the flat plate portion101and extending in the direction of the axis S, and a fitting hole103.

The flat plate portion101includes an annular joint surface101ato which the annular flat surface82aof the second inner yoke80is closely joined in the direction of the axis S, an annular joint surface101bto which the flange portion95of the cylindrical yoke90is closely joined in the direction of the axis S, and four circular holes101cthrough which the fastening screws b pass.

The attachment portion102is used to attach the valve device to the applicable object, and includes two circular holes102athrough which fixing bolts pass.

The fitting hole103is a region into which the second outer peripheral surface81of the second inner yoke80is fitted, and defines a cylindrical inner peripheral surface103acentered on the axis S. The inner peripheral surface103ais closely joined to the second outer peripheral surface81of the second inner yoke80in the radial direction perpendicular to the axis S.

That is, the second inner yoke80is joined and fixed to the flat yoke100in the radial direction perpendicular to the axis S via the inner peripheral surface103aof the fitting hole103.

The urging spring110is a compression type coil spring, and is arranged to be compressed in the direction of the axis S with one end portion111abutting against the spring receiving portion53of the movable element50and the other end portion112abutting against the spring receiving portion85aof the second inner yoke80. Then, the urging spring110urges the movable element50toward the rest position in the direction of the axis S.

As described above, the coil module120includes the bobbin121, the excitation coil122, and the molded portion123.

The bobbin121is formed using a resin material, and as shown inFIG.5, the bobbin121includes a small-diameter cylindrical portion121acentered on the axis S, a large-diameter cylindrical portion121b, an annular step portion121c, a flange portion121d, a flange portion121e, and a concave portion121f.

The small-diameter cylindrical portion121ais formed so that the cylindrical member130is fitted inside the small-diameter cylindrical portion121a, and the coil122is wound around the outside thereof.

The large-diameter cylindrical portion121bis formed so that the first outer peripheral surface71of the first inner yoke70is fitted inside the large-diameter cylindrical portion121b, and the coil122is wound around the outside thereof.

The annular step portion121cabuts against the end surface of the first inner yoke70so as to be positioned in the direction of the axis S in the assembled state.

The flange portion121dis formed into an annular shape centered on the axis S, and is arranged to face the first annular brim portion73(annular tapered surface73b) of the first inner yoke70and the annular flat plate portion94of the cylindrical yoke90in the direction of the axis S.

The flange portion121eis formed into an annular shape centered on the axis S, defines an annular tapered surface121e1in the root region thereof, and is arranged to face the flat yoke100in the direction of the axis S and receive the flange portion133of the cylindrical member130.

The concave portion121fis formed to receive the flange portion133of the cylindrical member130and receive the sealing member Sr.

The coil122is used for excitation to generate magnetic force when energized, and is wound around the small-diameter cylindrical portion121aand the large-diameter cylindrical portion121bof the bobbin121and connected to two terminals122a.

The molded portion123is molded using a resin material, and is molded to cover the entire body and expose the terminals122ainside the connector123ain a state where the coil122is wound around the bobbin121and the terminals122aare connected.

The cylindrical member130is press-formed (deep-drawn) into a bottomed cylindrical shape using a thin metal plate made of a non-magnetic material such as stainless steel. As shown inFIG.4andFIG.5, the cylindrical member130includes a cylindrical portion131centered on the axis S, a bottom wall132, and a flange portion133.

The cylindrical portion131is formed so that the outer peripheral surface51of the movable element50is slidably inserted into the cylindrical portion131and the second outer peripheral surface81of the second inner yoke80is fitted into the cylindrical portion131, and the inner peripheral surface72of the first inner yoke70and the small-diameter cylindrical portion121aof the bobbin121of the coil module120are fitted to the outside thereof.

The bottom wall132is arranged so that the movable element50and the shaft60are not in contact with each other in the rest state.

The flange portion133abuts against the flange portion121eof the bobbin121of the coil module120to be positioned in the direction of the axis S.

Then, in the assembled state, the cylindrical member130houses the movable element50and the second inner yoke80, and exposes the shaft60fixed to the movable element50to the outside, here, to the internal space of the housing10(the first working chamber11g, the central chamber11f, and the second working chamber11h).

That is, the cylindrical member130has the function of slidably guiding the movable element50, and isolating the internal region in which the movable element50operates from the external region to prevent fluid from leaking to the outside.

The sealing member Sr is an O-ring made of a rubber material, and is interposed between the flange portion133of the cylindrical member130and the flat yoke100in the assembled state to seal and prevent fluid from leaking to the outside.

Next, the assembly work of the valve device having the above configuration will be described with reference toFIG.17toFIG.20.

First, prior to assembling the valve device, the drive unit U is assembled. In this assembly step, the first valve body20is fitted and fixed at a predetermined position with respect to the shaft60, and the central connecting portion42of the sealing member40is connected. Thereafter, the shaft60is fitted and fixed to the movable element50.

Then, as shown inFIG.17, the drive unit U incorporating the first valve body20and the sealing member40, the housing body10a, the second valve body30, the housing cover10b, and four fastening screws b are prepared.

Subsequently, the shaft60and the first valve body20are inserted into the housing body10athrough the first opening11b, and the annular fitting portion41of the sealing member40is fitted into the annular groove15b, and as shown inFIG.18, the flat plate portion101of the flat yoke100is joined to the joint surface15aof the flange portion15. Then, the fastening screws b are screwed into the female screw holes15dof the housing body10athrough the circular holes95aand101c.

Subsequently, as shown inFIG.19, the second valve body30is inserted into the housing body10athrough the second opening11c, and while the shaft60is held using a predetermined jig inserted from the upstream passage12aor the first downstream passage13a, the shaft60is fitted and fixed so as to abut against the positioning portion61.

Subsequently, as shown inFIG.20, the housing cover10bis fitted and fixed to the cover coupling portion16of the housing body10a. It should be noted that the housing cover10bmay be fixed using an adhesive or the like as appropriate.

The above procedure completes the assembly of the valve device. This assembly procedure is merely an example, and the assembly may be performed by other methods and procedures.

Next, the operation of the valve device according to an embodiment will be described.

First, in the state where the coil122is not energized, the movable element50and the shaft60are located at the rest position due to the urging force of the urging spring110, as shown inFIG.15. At this rest position, the first valve body20is separated from the first valve seat11dto open the valve, and the second valve body30is seated on the second valve seat11eto close the valve.

Therefore, the fluid flowing from the upstream passage12aflows into the first downstream passage13avia the central chamber11fand the first working chamber11g.

On the other hand, when the coil122is energized, electromagnetic force is generated, and as shown inFIG.16, the movable element50is attracted to the second inner yoke80, and the movable element50and the shaft60are located at the operating position against the urging force of the urging spring110. At this operating position, the first valve body20is seated on the first valve seat11dto close the valve, and the second valve body30is separated from the second valve seat11eto open the valve.

Therefore, the fluid flowing from the upstream passage12aflows into the second downstream passage14avia the central chamber11fand the second working chamber11h.

By switching the coil122between energization and de-energization in this way, the fluid can flow from the first downstream passage13atoward an external fluid outlet pipe, or the fluid can flow from the second downstream passage14atoward another external fluid outlet pipe.

Here, in the configuration including the housing10which have the first valve seat11dand the second valve seat11eformed into annular tapered surfaces that form a part of the conical surfaces centered on the axis S, and the first valve body20and the second valve body30which have the convex curved surfaces22aand32ato respectively contact the annular tapered surfaces of the first valve seat11dand the second valve seat11e, even if the shaft60moves slightly off-axis or tilted, the first valve body20can come into close contact with the first valve seat11dto reliably close the valve, and the second valve body30can come into close contact with the second valve seat11eto reliably close the valve.

Although the above embodiment illustrates a configuration including the first valve body20and the second valve body30as the valve body, the disclosure is not limited thereto, and a configuration in which one valve body is provided on the shaft may be adopted. In this case, the valve base member of the valve body and the shaft may be integrally made of a resin material, and the elastic sealing member may be molded onto the integrally formed valve base member of the shaft.

Although the above embodiment illustrates the first valve body20and the second valve body30constituted by the valve base members21and31and the elastic sealing members22and32as the valve body, the disclosure is not limited thereto, and a valve body made of a single material such as a metal material or a resin material may be adopted as long as the valve body includes a convex curved surface to come into contact with the valve seat that forms an annular tapered surface.

Although the above embodiment illustrates a valve body that is formed to be rotationally symmetrical around the axis S and plane symmetrical with respect to the plane perpendicular to the axis S (the first valve body20and the second valve body30), the disclosure is not limited thereto, and the valve body may be formed to be asymmetrical with respect to the plane perpendicular to the axis S as long as the valve body includes the configuration of the disclosure.

Although the above embodiment illustrates a configuration in which the sealing member40having a structure similar to a diaphragm is adopted as a component of the valve device to prevent foreign matter in the fluid from entering the side of the drive unit U, the disclosure is not limited thereto, and the periphery of the shaft60may be sealed by fitting, for example, a lip-type seal at the end portion of the guide hole86of the second inner yoke. According to this, the pressure of the fluid does not act on the movable part, so the movable element and the valve body can be driven with smaller electromagnetic force.

As described above, according to the valve device of the disclosure, the valve body can be brought into close contact with the valve seat to reliably close the valve even if the shaft moves slightly off-axis or tilted. Therefore, the disclosure can not only be applied as a valve device in a cooling water circulation system of a vehicle or the like but is also useful as a valve device in other fields.