Patent Description:
An example of a flow channel switching valve that is one of existing valve devices is disclosed in Patent Literature <NUM>. The flow channel switching valve includes a valve body that has a valve chamber, a ball-like valve member that is disposed in the valve chamber, a valve shaft that is coupled with the valve member, and a rotation driving section that includes, for example, a drive gear and a motor that rotationally drives the valve member via the valve shaft.

Patent Literature <NUM>: <CIT>
<CIT> discloses a molded plastic flowmeter of simplified construction in the form of a one piece molded plastic body defining a float tube, tubular mounting studs at the base and the top of the float tube that also form the fluid connections to and from the tube, and a cylindrical valve chamber at the base of the float tube and aligned with the bore of the base stud, in which chamber a hollow cylindrical valve member is mounted.

<CIT> discloses a motorized bypass valve having a valve body with cylindrical valving chambers with a single inlet and a first and second outlet ported to the chamber.

<CIT> discloses a method for manufacturing a tube of a caoutchouc or plastic material provided with reinforcement insertions and equipped with a lateral branch.

<CIT> discloses a fitting tool for connecting a fluid supply piping.

As for such a flow channel switching valve, the shape of a tubular flow channel connected to a valve body may be changed so as to be suitable for a system into which the flow channel switching valve is incorporated. In Patent Literature <NUM>, three ports as flow channels that have a circular tube shape are each formed so as to linearly extend from the valve body. However, a flow channel, for example, formed in an L-shape may be used in some cases where a hose that is connected to the flow channel is directed to a certain direction.

The L-shaped flow channel includes a first portion that linearly extends from the valve body and a second portion that serves as a hose joint that is connected perpendicular to the first portion. In the case where the L-shaped flow channel is manufactured by injection molding, a tip end of the first portion has an opening for extracting a core of a mold, and a lid member that covers the opening is joined to the tip end of the first portion.

The lid member is joined in a manner in which the lid member is stacked on the tip end of the first portion, the first portion or a portion that is further from the lid member than the first portion is supported by a jig, and an ultrasonic vibration is applied to the lid member for welding. During ultrasonic welding, a planar surface (that is, a planar surface that faces in the opposite direction from the tip end of the first portion) that faces in a direction in which the ultrasonic vibration is applied needs to be supported by the jig. However, only the valve body has such a planar surface. Accordingly, the distance between a portion that is supported by the jig and a portion that is welded is long, and there is a possibility that the efficiency of ultrasonic welding decreases. In addition, there is a possibility that a connection between the first portion and the second portion damages and deforms due to force that is applied thereto when the hose is mounted on the second portion.

In view of this, it is an object of the present invention to provide a valve device that can effectively inhibit the efficiency of ultrasonic welding for a flow channel from decreasing and that can increase the rigidity of the flow channel, and a method for assembling the valve device.

To achieve the object described above, a valve device according to an aspect of the present invention as defined in claim <NUM> includes a valve body that has a valve chamber, tubular flow channels that are in communication with the valve chamber and that are connected to the valve body, and a valve member that is installed in the valve chamber and that switches between connections of the flow channels. At least one flow channel of the flow channels includes a first portion that is connected to the valve body and that is linear, a second portion that is connected at an angle to the first portion and that is linear, a lid member that is joined such that the lid member covers an opening of a tip end of the first portion, and a pair of projecting portions that is disposed such that the projecting portions interpose the first portion therebetween in a radial direction and face each other and that extends from an outer circumferential surface of the first portion to an outer circumferential surface of the second portion.

According to the present invention, the pair of projecting portions includes a planar surface portion that faces the valve body direction.

In the present invention, a connecting portion that extends in a circumferential direction on the outer circumferential surface of the first portion such that the connecting portion couples the pair of projecting portions with each other is further included.

In the present invention, the pair of projecting portions preferably protrudes toward a tip end of the second portion and is arranged nearer the tip end of the second portion than the first portion when viewed in an axial direction of the first portion.

To achieve the object described above, a method for assembling a valve device according to another aspect of the present invention as defined in claim <NUM> is a method for assembling a valve device that includes a valve body that has a valve chamber, tubular flow channels that are in communication with the valve chamber and that are connected to the valve body, and a valve member that is installed in the valve chamber and that switches between connections of the flow channels, at least one flow channel of the flow channels including a first portion that is connected to the valve body and that is linear and a second portion that is connected at an angle to the first portion and that is linear. The method includes supporting a planar surface portion that faces the valve body direction and that is included in a pair of projecting portions that is disposed such that the projecting portions interpose the first portion therebetween in a radial direction and face each other and that extends from an outer circumferential surface of the first portion to an outer circumferential surface of the second portion; and stacking a lid member on an opening of a tip end of the first portion and welding the lid member to the first portion by applying an ultrasonic vibration to the lid member.

According to the present invention, at least one flow channel of the flow channels includes the first portion that is connected to the valve body and that is linear, the second portion that is connected at an angle to the first portion and that is linear, the lid member that is joined such that the lid member covers the opening of the tip end of the first portion, and the pair of projecting portions that is disposed such that the projecting portions interpose the first portion therebetween in the radial direction and face each other and that extends from the outer circumferential surface of the first portion to the outer circumferential surface of the second portion. In this way, the lid member can be welded by ultrasonic welding with the pair of projecting portions supported. Accordingly, the efficiency of ultrasonic welding can be inhibited from decreasing because the pair of projecting portions is relatively near a welded portion. Since the pair of projecting portions extends from the outer circumferential surface of the first portion to the outer circumferential surface of the second portion, parts on which the projecting portions are disposed have a thickness greater than that of the other part, and the rigidity of a connection between the first portion and the second portion can be increased. Accordingly, the efficiency of ultrasonic welding for the flow channel can be effectively inhibited from decreasing, and the rigidity of the flow channel can be increased. Since the pair of projecting portions includes the planar surface portion that faces the valve body direction, the pair of projecting portions can be stably supported.

Since the connecting portion that extends in the circumferential direction on the outer circumferential surface of the first portion so as to couple the pair of projecting portions with each other is further included, the rigidity of the connection between the first portion and the second portion can be further increased.

Since the pair of projecting portions protrudes toward the tip end of the second portion and is arranged nearer the tip end of the second portion than the first portion when viewed in the axial direction of the first portion, the hose is brought into contact with the end surfaces of the pair of projecting portions that face the tip end of the second portion, and the projecting portions can function as a positioning stopper for the hose.

A flow channel switching valve corresponding to a valve device according to an embodiment of the present invention will now be described with reference to <FIG>.

<FIG> is a perspective view of the flow channel switching valve according to the embodiment of the present invention. <FIG> is a left side view of the flow channel switching valve in <FIG>. <FIG> is a plan view of the flow channel switching valve in <FIG> with an upper wall portion of a gear case portion removed. <FIG> is a cross-sectional view (a vertical cross-sectional view) of the flow channel switching valve in <FIG> taken along a rotation axis of a valve member. <FIG> is a cross-sectional view taken along line A-A in <FIG>. <FIG> is a left side view of the structure of a modification to the flow channel switching valve in <FIG>. <FIG> illustrate a method for assembling the flow channel switching valve in <FIG>. <FIG> show a state in which a molded body that has an integrated valve body and flow channels supported by a jig. <FIG> is a side view. <FIG> is a top view. In the following description, the terms "upper, lower, left, and right" are used to represent relative positional relationships of components in the figures and do not represent absolute positional relationships. In <FIG>, an X-axis direction represents a left-and-right direction, a Y-axis direction represents a front-and-rear direction (a front-back direction), and a Z-axis direction represents an up-and-down direction. An X-axis, a Y-axis, a Z-axis are perpendicular to each other.

As illustrated in the figures, a flow channel switching valve <NUM> according to the present embodiment includes a valve body <NUM>, a first flow channel <NUM>, a second flow channel <NUM>, and a third flow channel <NUM> that have a circular tube shape, a ball valve member <NUM> that serves as a valve member, seat members <NUM>, sealing members <NUM>, and a valve shaft <NUM>. The flow channel switching valve <NUM> also includes a case <NUM>, a driving section <NUM>, and a rotational position detection portion <NUM>.

The valve body <NUM> is composed of, for example, synthetic resin such as polyphenylene sulfide (PPS) and has a substantially cubic box shape an upper end of which has an opening.

The first flow channel <NUM> that has a substantially L-shape is formed on a left side wall portion 10a of the valve body <NUM>. The second flow channel <NUM> that is linear is formed on a front wall portion 10b of the valve body <NUM>. The third flow channel <NUM> that is plane-symmetrical with the first flow channel <NUM> and that has a substantially L-shape is formed on a right side wall portion 10c of the valve body <NUM>. The first flow channel <NUM>, the second flow channel <NUM>, and the third flow channel <NUM> are in communication with a valve chamber <NUM> that is formed in the valve body <NUM>. Two flow channels or four or more flow channels in communication with the valve chamber <NUM> may be formed.

The first flow channel <NUM> includes a first portion 11a, a second portion 11b, a lid member 11c, a pair of projecting portions 11d, and a connecting portion 11e. The first portion 11a is linear and is connected to the left side wall portion 10a of the valve body <NUM>. A tip end 11a1 of the first portion 11a has an opening for extracting the core of a mold. The second portion 11b is linear and is connected so as to be perpendicular to (be at a right angle to) an intermediate part of the first portion 11a. The second portion 11b serves as a joint to which a hose is connected. The first portion 11a and the second portion 11b may connect each other at an angle that is not the right angle. The lid member 11c is joined by ultrasonic welding so as to cover the opening of the tip end 11a1 of the first portion 11a.

The projecting portions 11d have a quadrangular prism shape that linearly extends. The pair of the projecting portions 11d extends in an axial direction (the Y-axis direction) of the second portion 11b from the outer circumferential surface of the first portion 11a to the outer circumferential surface of the second portion 11b. In other words, the pair of the projecting portions 11d extends across the outer circumferential surface of the first portion 11a and the outer circumferential surface of the second portion 11b. The connecting portion 11e has an arced quadrangular prism shape and extends in a circumferential direction on the outer circumferential surface of the first portion 11a so as to couple the pair of the projecting portions 11d with each other. The pair of the projecting portions 11d and the connecting portion 11e have the same rectangular cross-sectional shape of a rectangle over the entire length in the longitudinal direction. The pair of the projecting portions 11d and the connecting portion 11e are integrally formed with the first portion 11a and the second portion 11b. For this reason, parts of the first portion 11a and the second portion 11b on which the pair of the projecting portions 11d and the connecting portion 11e are disposed have a thickness greater than that of the other part. The pair of the projecting portions 11d and the connecting portion 11e are connected to each other so as to form a substantially U-shape when viewed in the axial direction (the X-axis direction) of the first portion 11a. As for the pair of the projecting portions 11d, front end portions (end portions opposite the connecting portion 11e) protrude toward the tip end of the second portion 11b and are arranged nearer the tip end of the second portion 11b than the first portion 11a when viewed in the axial direction of the first portion 11a. Consequently, the pair of the projecting portions 11d functions as a positioning stopper with which the hose comes into contact when the hose is mounted on the second portion 11b.

The pair of the projecting portions 11d and the connecting portion 11e include a planar surface portion 11f that faces the valve body <NUM> direction (in the opposite direction from the tip end 11a1 of the first portion 11a). The shapes and widths (sizes in the X-axis direction) of the pair of the projecting portions 11d and the connecting portion 11e are freely determined unless it goes against the purpose of the present invention. For example, the pair of the projecting portions 11d may have a triangular prism shape (a cross-sectional shape is a right triangle shape). The projecting portions 11d may have a width equal to a distance between the second portion 11b and the tip end 11a1 of the first portion 11a. The pair of the projecting portions 11d and the connecting portion 11e have a shape that can be supported by a jig <NUM> described later. The pair of the projecting portions 11d and the connecting portion 11e preferably include the planar surface portion 11f that faces the valve body <NUM> direction. As for the flow channel switching valve <NUM>, the connecting portion 11e may be omitted as in a flow channel switching valve 1A according to a modification to the present embodiment illustrated in <FIG>.

The third flow channel <NUM> includes a first portion 13a, a second portion 13b, a lid member 13c, a pair of projecting portions 13d, and a connecting portion 13e as in the first flow channel <NUM>. The lid member 13c is joined by ultrasonic welding so as to cover the opening of a tip end 13a1 of the first portion 13a. The pair of the projecting portions 13d and the connecting portion 13e include a planar surface portion 13f that faces the valve body <NUM> direction (in the opposite direction from the tip end 13a1 of the first portion 13a). The third flow channel <NUM> has the same structure as that of the first flow channel <NUM> except that the third flow channel <NUM> is plane-symmetrical with the first flow channel <NUM>, and a detailed description is omitted.

In the present embodiment, the opening of a tip end 11b1 of the second portion 11b of the first flow channel <NUM>, the opening of a tip end 12a of the second flow channel <NUM>, and the opening of a tip end 13b1 of the second portion 13b of the third flow channel <NUM> are directed in the same direction (the front direction).

The ball valve member <NUM> is composed of, for example, a material such as metal or synthetic resin and has a hollow ball-like shape (a spherical shape). The ball valve member <NUM> is rotatably supported by the seat members <NUM> and is installed in the valve chamber <NUM>. The ball valve member <NUM> has a first opening <NUM> that opens in the left-hand direction, a second opening <NUM> that opens in the front direction, and a third opening <NUM> that opens in the righthand direction when being located at a rotational position illustrated in <FIG>. A switching flow channel <NUM> that has a substantially T-shape in a plan view and that connects the first opening <NUM>, the second opening <NUM>, and the third opening <NUM> to each other is formed in the ball valve member <NUM>. For example, the ball valve member <NUM> may have only the first opening <NUM> and the second opening <NUM>, and the switching flow channel <NUM> may have a substantially L-shape in a plan view and may connect the first opening <NUM> and the second opening <NUM> to each other when being located at the rotational position illustrated in <FIG>. In the present embodiment, the ball valve member <NUM> is used as the valve member, but a columnar valve member may be used.

The switching flow channel <NUM> is formed such that connections among the first flow channel <NUM>, the second flow channel <NUM>, and the third flow channel <NUM> are switched depending on the rotational position of the ball valve member <NUM>. Specifically, the switching flow channel <NUM> connects the first flow channel <NUM>, the second flow channel <NUM>, and the third flow channel <NUM> to each other when the ball valve member <NUM> is located at the rotational position illustrated in <FIG>. The switching flow channel <NUM> connects the first flow channel <NUM> and the second flow channel <NUM> to each other when the ball valve member <NUM> is located at the rotational position at which the ball valve member <NUM> is rotated <NUM> degrees clockwise in a plan view from the rotational position illustrated in <FIG>. The switching flow channel <NUM> connects the second flow channel <NUM> and the third flow channel <NUM> to each other when the ball valve member <NUM> is located at the rotational position at which the ball valve member <NUM> is rotated <NUM> degrees counterclockwise in a plan view from the rotational position illustrated in <FIG>.

A valve shaft insertion hole <NUM> in which the valve shaft <NUM> described later is inserted is formed in an upper portion of the ball valve member <NUM>. The valve shaft insertion hole <NUM> is formed such that the ball valve member <NUM> is rotated about an axis L corresponding to a rotation axis together with rotation of the valve shaft <NUM> with the valve shaft <NUM> inserted therein. In the present embodiment, the valve shaft insertion hole <NUM> has a regular hexagonal shape.

The seat members <NUM> are composed of, for example, synthetic resin such as polytetrafluoroethylene (PTFE) and have an annular shape. The seat members <NUM> are paired with each other and are installed in the valve chamber <NUM> so as to face each other in an interval in the left-and-right direction. The seat members <NUM> interpose and rotatably support the ball valve member <NUM> in the valve chamber <NUM>.

The sealing members <NUM> are, for example, O-rings composed of an elastic material such as a rubber material, one of which is interposed between one of the seat members <NUM> and the left side wall portion 10a of the valve body <NUM> so as to be in a compressed state, and the other of which is interposed between the other seat member <NUM> and the right side wall portion 10c of the valve body <NUM> so as to be in the compressed state. In the present embodiment, the sealing members <NUM> are fitted in annular grooves 30a that the seat members <NUM> have and partly project from the annular grooves 30a. The sealing members <NUM> seal a space between the valve body <NUM> and the ball valve member <NUM> together with the seat members <NUM>. The valve device may have a structure to omit the sealing members <NUM> and instead employ seat members <NUM> that are composed of an elastic material such as a rubber material and that have the function of the sealing members.

The valve shaft <NUM> is composed of synthetic resin, has a columnar shape that linearly extends overall, and includes a round columnar portion <NUM> and a prism portion <NUM> that is coaxially connected to the lower end of the round columnar portion <NUM>. The valve shaft <NUM> extends along the axis L.

A groove is formed on a lower end portion of the round columnar portion <NUM> over the entire circumference, and an O-ring <NUM> that is composed of, for example, a rubber material and that has an annular shape is fitted in the groove. A large-diameter gear <NUM> of the driving section <NUM> is coaxially mounted on an upper end portion of the round columnar portion <NUM>. A mounting hole <NUM> that has a substantially round columnar shape along the axis L is formed at the center of an end surface 41a of the round columnar portion <NUM> that faces upward. A potentiometer shaft <NUM> of the rotational position detection portion <NUM> is mounted in the mounting hole <NUM> by press-fitting.

The prism portion <NUM> has a columnar shape a cross-sectional shape (a transverse cross-sectional shape) perpendicular to the axis L of which is a regular hexagonal shape as in the valve shaft insertion hole <NUM>. The prism portion <NUM> is inserted in the valve shaft insertion hole <NUM> of the ball valve member <NUM> and is consequently mounted on the ball valve member <NUM> along the axis L. The transverse cross-sectional shape of the prism portion <NUM> is a regular hexagonal shape as in the valve shaft insertion hole <NUM>. For this reason, the valve shaft insertion hole <NUM> and the prism portion <NUM> fit together, and the ball valve member <NUM> is rotated about the axis L together with rotation of the valve shaft <NUM>. The prism portion <NUM> may have a polygonal columnar shape such as a triangular prism shape or a quadrangular prism shape, or a columnar having a D-shaped cross-section having a plane on a part of the circumferential surface, in addition to a regular hexagonal shape. In this case, the valve shaft insertion hole <NUM> has the same shape as the transverse cross-sectional shape of the prism portion <NUM>.

The case <NUM> is composed of, for example, synthetic resin such as polyphenylene sulfide (PPS) and is mounted on the valve body <NUM>. The driving section <NUM> is installed in the case <NUM>. The case <NUM> includes a motor case portion <NUM> and a gear case portion <NUM>.

The motor case portion <NUM> has a bottomed cylindrical shape, and a motor <NUM> of the driving section <NUM> is installed therein.

The gear case portion <NUM> includes a bottom wall portion <NUM> that is integrally formed with the motor case portion <NUM> and that has a flat plate shape, an upper wall portion <NUM> in which a ventilation portion <NUM> is disposed, and a peripheral wall portion <NUM> that couples the bottom wall portion <NUM> and the upper wall portion <NUM> with each other. In the present embodiment, the bottom wall portion <NUM> and the peripheral wall portion <NUM> are integrally formed with each other, and the upper wall portion <NUM> is mounted on the upper end of the peripheral wall portion <NUM> by using, for example, a screw structure or a snap-fit structure not illustrated. A first worm <NUM>, an intermediate gear body <NUM>, and the large-diameter gear <NUM> of the driving section <NUM> and the rotational position detection portion <NUM> are installed in the gear case portion <NUM>.

The gear case portion <NUM> includes a cylindrical bearing portion <NUM> that is integrated with the bottom wall portion <NUM>. The round columnar portion <NUM> of the valve shaft <NUM> is inserted in the bearing portion <NUM>, and the bearing portion <NUM> rotatably supports the round columnar portion <NUM>. The gear case portion <NUM> includes an inner peripheral wall portion <NUM> that protrudes downward from the bottom wall portion <NUM> and that has a substantially square tube shape. The inner peripheral wall portion <NUM> is inserted in the valve body <NUM> and is joined to the valve body <NUM> by, for example, ultrasonic welding. The gear case portion <NUM> may be mounted on the valve body <NUM> by using, for example, a screw structure.

The driving section <NUM> drives and rotates the ball valve member <NUM> by using the valve shaft <NUM>. The driving section <NUM> includes the motor <NUM>, the first worm <NUM> that is included in a speed reducer, the intermediate gear body <NUM>, and the large-diameter gear <NUM>.

The motor <NUM> is disposed in the motor case portion <NUM> such that a driving shaft 61a protrudes from a through-hole that is formed in the bottom wall portion <NUM> of the gear case portion <NUM> to the space in the gear case portion <NUM>. The first worm <NUM> is mounted on the tip end of the driving shaft 61a.

The intermediate gear body <NUM> is disposed in the gear case portion <NUM>. The intermediate gear body <NUM> includes a shaft portion <NUM>, a small-diameter gear <NUM> (a first worm wheel) that is disposed on one end portion 64a of the shaft portion <NUM> and that engages with the first worm <NUM>, and a second worm <NUM> that is disposed on the other end portion 64b of the shaft portion <NUM> and that engages with the large-diameter gear <NUM> (a second worm wheel).

The large-diameter gear <NUM> is disposed in the gear case portion <NUM>. The round columnar portion <NUM> of the valve shaft <NUM> is mounted in a through-hole that is formed at the center of the large-diameter gear <NUM> by press-fitting.

The driving section <NUM> transmits rotational force of the driving shaft 61a of the motor <NUM> to the valve shaft <NUM> via the first worm <NUM>, the intermediate gear body <NUM>, and the large-diameter gear <NUM> and causes the valve shaft <NUM> to rotate about the axis L. Consequently, the ball valve member <NUM> moves to the desired rotational position.

The rotational position detection portion <NUM> includes the potentiometer shaft <NUM> corresponding to a rotation angle output shaft, a potentiometer base <NUM> corresponding to a base body, and a potentiometer <NUM> corresponding to a rotation angle sensor.

The potentiometer shaft <NUM> is composed of, for example, metal such as stainless steel or brass, or synthetic resin such as polyphenylene sulfide (PPS) and is formed separately from the valve shaft <NUM>. The potentiometer shaft <NUM> is press-fitted in the mounting hole <NUM> of the valve shaft <NUM> and is coaxially secured to and mounted on the valve shaft <NUM>. As for the potentiometer shaft <NUM>, a fitting shaft portion 81a that is disposed on an upper end portion and that has a D-shape engages with a rotor <NUM> of the potentiometer <NUM>. The fitting shaft portion 81a may be integrally formed with the end surface 41a of the valve shaft <NUM>.

The potentiometer base <NUM> is composed of synthetic resin and integrally includes a base main body portion <NUM> and a sensor support portion <NUM>. The base main body portion <NUM> has a substantially flat plate shape and is secured to a boss, not illustrated, that protrudes upward from the bottom wall portion <NUM> of the gear case portion <NUM> by using screws <NUM>. The sensor support portion <NUM> has a substantially disk shape the diameter of which is smaller than that of the large-diameter gear <NUM>, and the potentiometer <NUM> is mounted at the center. The sensor support portion <NUM> is disposed in the gear case portion <NUM> so as to overlap the large-diameter gear <NUM> from above.

The potentiometer <NUM> is the rotation angle sensor for detecting a rotation angle. The potentiometer <NUM> includes the rotor <NUM> that has a disk shape and a meter main body portion <NUM> corresponding to a signal output portion that rotatably supports the rotor <NUM> and that outputs a signal (voltage) depending on the rotation angle of the rotor <NUM>. A fitting hole that has a D-shape in a plan view is formed at the center of the rotor <NUM>. The fitting shaft portion 81a of the potentiometer shaft <NUM> is fitted in the fitting hole such that the fitting shaft portion 81a extends therethrough and such that the rotor <NUM> is rotated together with the fitting shaft portion 81a. The rotor <NUM> is rotated together with rotation of the fitting shaft portion 81a. Consequently, the potentiometer <NUM> detects the rotation angle of the potentiometer shaft <NUM> (that is, the valve shaft <NUM> and the ball valve member <NUM>) about the axis L.

As for the flow channel switching valve <NUM>, the rotational force of the driving shaft 61a of the motor <NUM> that is included in the driving section <NUM> is transmitted to the valve shaft <NUM> via, for example, the large-diameter gear <NUM>, and the valve shaft <NUM> is rotated about the axis L. The ball valve member <NUM> is rotated about the axis L together with rotation of the valve shaft <NUM> and moves to the rotational position. This achieves connections of the flow channels depending on the rotational position. The potentiometer shaft <NUM> is rotated about the axis L together with the valve shaft <NUM>, and a signal depending on the rotation angle of the potentiometer shaft <NUM> is outputted from the potentiometer <NUM>. The rotational position of the ball valve member <NUM> can be monitored based on the signal that is outputted from the potentiometer <NUM>.

A method for assembling the flow channel switching valve <NUM> according to the present embodiment described above will now be described with reference to <FIG>.

A molded body <NUM> that includes the valve body <NUM>, the first flow channel <NUM> (except for the lid member 11c), the second flow channel <NUM>, and the third flow channel <NUM> (except for the lid member 13c) that are integrated with each other is first obtained by injection molding.

Subsequently, the molded body <NUM> is mounted on the jig <NUM>. As illustrated in <FIG>, the jig <NUM> includes a foundation <NUM> that has a rectangular flat plate shape, a support column <NUM> that extends upward from the foundation <NUM>, and a support plate <NUM> that has a flat plate shape and that is mounted on the support column <NUM> such that an upper surface 203a is horizontal. The support plate <NUM> has a notch (not illustrated) that is along the shape of the outer circumferential surface of the first portion 11a of the first flow channel <NUM>. The support plate <NUM> has a substantially U-shape when viewed from above. The first flow channel <NUM> is inserted into the notch of the support plate <NUM> with the tip end 11a1 of the first portion 11a facing upward. The planar surface portion 11f of the first flow channel <NUM> is stacked on the upper surface 203a of the support plate <NUM>. A retaining member, not illustrated, is mounted on the support plate <NUM>, and the first flow channel <NUM> is secured to the jig <NUM>. Consequently, the planar surface portion 11f of the first flow channel <NUM> of the molded body <NUM> is supported by the jig <NUM>.

Subsequently, the lid member 11c is stacked so as to cover the opening of the tip end 11a1 of the first portion 11a, and as schematically illustrated by a thick arrow in <FIG>, an ultrasonic vibration is applied to the lid member 11c from above. Consequently, the lid member 11c is joined to the tip end 11a1 of the first portion 11a by ultrasonic welding. As for the third flow channel <NUM>, the planar surface portion 13f is supported by the jig <NUM>, and the lid member 13c is joined as in the first flow channel <NUM>.

The ball valve member <NUM>, the seat members <NUM>, and the sealing members <NUM> are installed in the valve body <NUM> of the molded body <NUM> to which the lid members 11c and 13c are joined. The valve shaft <NUM> is mounted on the ball valve member <NUM>, and the case <NUM> is mount on the valve body <NUM>. The driving section <NUM> and the rotational position detection portion <NUM> are installed in the case <NUM>, and the flow channel switching valve <NUM> is completed.

As for the flow channel switching valve <NUM> according to the present embodiment described above, the first flow channel <NUM> includes the first portion 11a that is connected to the valve body <NUM> and that is linear, the second portion 11b that is connected such that the second portion 11b is perpendicular to the first portion 11a and that is linear, the lid member 11c that is joined such that the lid member 11c covers the opening of the tip end 11a1 of the first portion 11a, and the pair of the projecting portions 11d that is disposed such that the projecting portions 11d interpose the first portion 11a therebetween in the radial direction and face each other and that extends from the outer circumferential surface of the first portion 11a to the outer circumferential surface of the second portion 11b. In this way, the lid member 11c can be welded by ultrasonic welding with the pair of the projecting portions 11d supported. Accordingly, the efficiency of ultrasonic welding can be inhibited from decreasing because the pair of the projecting portions 11d is relatively near the welded portion. Since the pair of the projecting portions 11d extends from the outer circumferential surface of the first portion 11a to the outer circumferential surface of the second portion 11b, the parts on which the projecting portions 11d are disposed have a thickness greater than that of the other part, and the rigidity of the connection between the first portion 11a and the second portion 11b can be increased. Accordingly, the rigidity of the first flow channel <NUM> can be increased, and the efficiency of ultrasonic welding for the first flow channel <NUM> can be effectively inhibited from decreasing. Since the pair of the projecting portions 11d includes the planar surface portion 11f that faces the valve body <NUM> direction, the pair of the projecting portions 11d can be stably supported.

The connecting portion 11e that extends in the circumferential direction on the outer circumferential surface of the first portion 11a so as to couple the pair of the projecting portions 11d with each other and that has an arc shape is further included. In this way, the rigidity of the connection between the first portion 11a and the second portion 11b can be further increased.

The pair of the projecting portions 11d protrudes toward the tip end of the second portion 11b and is arranged nearer the tip end of the second portion 11b than the first portion 11a when viewed in the axial direction (the X-axis direction) of the first portion 11a. In this way, the hose is brought into contact with the end surfaces of the pair of the projecting portions 11d that face the tip end of the second portion 11b, and the projecting portions 11d can function as the positioning stopper for the hose.

The third flow channel <NUM> has the same structure as that of the first flow channel <NUM> and exerts the same effects.

The flow channel switching valve <NUM> according to the embodiment described above switches between connections among the first flow channel <NUM>, the second flow channel <NUM>, and the third flow channel <NUM> by using the ball valve member <NUM>. The present invention, however, can be used for different kinds of valve devices unless it goes against the purpose thereof. For example, the present invention may be used for a valve device such as an on-off valve in which two tubular flow channels are connected to a valve body, and a valve member that is installed in the valve body connects or blocks the two flow channels.

Claim 1:
A valve device comprising: a valve body (<NUM>) that has a valve chamber (<NUM>); tubular flow channels (<NUM>, <NUM>, <NUM>) that are in communication with the valve chamber (<NUM>) and that are connected to the valve body (<NUM>); and a valve member (<NUM>) that is installed in the valve chamber (<NUM>) and that switches between connections of the flow channels (<NUM>, <NUM>, <NUM>),
wherein at least one flow channel (<NUM>) of the flow channels (<NUM>, <NUM>, <NUM>) includes a first portion (11a) that is connected to the valve body (<NUM>) and that is linear, a second portion (11b) that is connected at an angle to the first portion (11a) and that is linear, a lid member (11c) that is joined such that the lid member (11c) covers an opening of a tip end (11a1) of the first portion (11a), and a pair of projecting portions (11d) that is disposed such that the projecting portions (11d) interpose the first portion (11a) therebetween in a radial direction and face each other,
wherein the pair of projecting portions (11d) extends in an axial direction of the second portion (11b) from an outer circumferential surface of the first portion (11a) to an outer circumferential surface of the second portion (11b),
characterized in that the pair of the projecting portions (11d) extends across the outer circumferential surface of the first portion (11a) and the outer circumferential surface of the second portion (11b),
the valve device further comprising a connecting portion (11e) that extends in a circumferential direction on the outer circumferential surface of the first portion (11a) such that the connecting portion (11e) couples the pair of projecting portions (11d) with each other, so as to form a substantially U-shape when viewed in the axial direction of the first portion (11a),
the pair of projecting portions (11d) and the connecting portion (11e) include a planar surface portion (11f) that faces the valve body direction, which is the opposite direction from the tip end (11a1) of the first portion (11a).