Fluid control valve

Abstract

The present invention comprises: a housing body 7 that has four first to fourth ports 13-16; a rotary valve 4 that is rotatably accommodated in a valve accommodation chamber 3; annular port seals 11 each accommodated in an annular seal accommodation groove 7c formed at an opening end of each port; and retainers 12 that hold the port seals inside the seal accommodation grooves. The port seals each include: a seal part 11b that is in sliding contact with an outer peripheral surface of the rotary valve; and a pair of branch lip parts 11c, 11c that are branched from the seal part. The retainers each include: an annular seat surface part 12b, the inner surface 12e of which abuts the tip of each branch lip part; and a protrusion part 12c that is provided so as to protrude from the seat surface part to the space between the branch lip parts.　Therefore, according to the configuration, durability of sealing members is improved and smooth rotation of the rotary valve can be obtained.

Description

Fluid control valve

[0001] The present invention relates to a fluid control valve.

[0002] As a conventional fluid control valve, for example, the one described in Patent Document 1 below is known. This fluid control valve switches and controls a flow path for supplying and discharging fluid to and from vehicle devices. The valve housing has a cylindrical valve chamber at the center, and two radial ports are formed at positions facing each other in the radial direction around the axis of this valve chamber. Also, a cylindrical valve body is rotatably provided in the valve chamber. This valve body has valve openings formed in its peripheral wall that can communicate the inside with each of the radial ports according to the rotational position.

[0003] Further, an annular packing mounting groove is formed on the inner peripheral edge of the opening end facing the valve chamber of each radial port. A seal member, which is a packing, is mounted in this packing mounting groove. This seal member is integrally formed in a cylindrical shape from a rubber material and is arranged in a state of being sandwiched between the peripheral wall of the packing mounting groove and the inner peripheral side wall of the packing mounting member. The seal member has a flange-shaped base end portion at one end in the axial direction held in a sandwiched state between the step of the packing mounting groove and the bottom wall of the packing mounting member, and a tip portion at the other end in the axial direction is provided slidably on the outer peripheral surface of the valve body via the valve chamber.

[0004] Further, protruding portions that protrude toward the inner peripheral side of each packing mounting groove are provided at the tip portions on the valve chamber side on both sides in the rotational direction of the valve body of the outer peripheral side groove wall of the packing mounting groove.

[0005] According to this, even if a frictional force from the valve body to the front side in the rotational direction is generated at the tip portion of the seal member located on the front side in the rotational direction of the valve body, the tip portion is suppressed by the protruding portion, so that deterioration of the sealing performance can be suppressed.

[0006] Japanese Unexamined Patent Application Publication No. 2020 - 159439

[0007] However, in the conventional fluid control valve described in Patent Document 1, as mentioned above, the sealing member is formed in a cylindrical shape and is fixedly positioned between the peripheral wall of the packing mounting groove and the inner peripheral side wall of the packing mounting member. As a result, it has high rigidity and cannot be flexibly deformed in the axial direction.

[0008] Therefore, if the amount of protrusion of the tip of the sealing member in the direction of the valve body increases even slightly, the sliding friction resistance between the tip of the sealing member and the outer surface of the valve body will increase. As a result, wear and other damage may occur more easily at the tip of the sealing member, reducing the durability of the sealing member and potentially affecting the smooth rotation of the valve body.

[0009] This invention was devised in view of the technical problems of the prior art, and one of its objectives is to provide a fluid control valve that can improve the durability of the sealing member and achieve smooth rotation of the rotary valve by suppressing the increase in sliding friction resistance between the tip of the sealing member and the outer surface of the rotary valve.

[0010] In one aspect of the present invention, the sealing member is characterized by having a sealing portion that slides against the outer circumferential surface of the rotary valve, and a pair of branched lip portions that branch off from the sealing portion and extend in the direction of the seal housing groove, and the retainer is characterized by having an annular seating surface portion whose outer surface sits on the bottom surface of the seal housing groove, with the tips of the pair of branched lip portions abutting against its inner surface and forming a space between the pair of branched lip portions, and a projection that protrudes from the annular seating surface portion into the space.

[0011] According to an aspect of the present invention, a decrease in sealing performance and an increase in excessive sliding friction resistance between the tip of the sealing member and the outer surface of the rotary valve can be suppressed, thereby improving the durability of the sealing member and enabling smooth rotation of the rotary valve.

[0012] This is an overhead view of a fluid control valve according to an embodiment of the present invention. This is an exploded perspective view of the fluid control valve of this embodiment. This is a front view of the same fluid control valve. This is a cross-sectional view taken along line A-A in Figure 3. This is a cross-sectional view taken along line B-B in Figure 3. This is an enlarged view of section C in Figure 5. This shows a seal member used in the fluid control valve of this embodiment, where (a) is a front view of the seal member, (b) is a plan view of the seal member, and (c) is a left side view of the seal member. This shows a retainer used in the fluid control valve of this embodiment, where (a) is a front view of the retainer, (b) is a plan view of the retainer, and (c) is a left side view of the retainer. This is a schematic diagram showing multiple switching modes by the fluid control valve of this embodiment, where (a) to (h) are explanatory diagrams illustrating the operation of switching the fluid circuit by sequentially rotating the rotation position of the rotary valve from 0° in 45° increments. This is an overhead view of a retainer used in a second embodiment of the present invention. This is an enlarged view of section C in Figure 5 showing a third embodiment of the present invention.

[0013] Hereinafter, embodiments of the fluid control valve according to the present invention will be described with reference to the drawings. In this embodiment, an example will be given in which the fluid control valve is applied to a cooling water circulation system that supplies coolant to the equipment of an automobile.

[0014] Figure 1 is an overhead view of a fluid control valve according to an embodiment of the present invention, Figure 2 is an exploded perspective view of the fluid control valve of this embodiment, Figure 3 is a front view of the same fluid control valve, Figure 4 is a cross-sectional view taken along line A-A in Figure 3, and Figure 5 is a cross-sectional view taken along line B-B in Figure 3.

[0015] As shown in Figures 1 to 3, the fluid control valve 1 in this embodiment includes a valve housing 2, a cylindrical valve housing chamber 3 formed inside the valve housing 2, a rotary valve 4 rotatably housed and supported inside the valve housing chamber 3, and an electric motor 6 and a gear mechanism (not shown) which are actuators provided at the upper end of the valve housing 2 and which rotate the rotary valve 4 via a rotating shaft 5 located at the upper end of the rotary valve 4.

[0016] The valve housing 2 is integrally formed from a synthetic resin material and, as shown in Figure 2, has a covered cylindrical housing body 7 and a cover member 8 provided at one axial end of the housing body 7 (the lower end in Figure 3) to close the opening 3a of the valve housing chamber 3. The housing body 7 has an integrally formed frame portion 9 with a substantially rectangular planar shape along the outer circumference of the opening 3a. This frame portion 9 has four boss portions 9a provided at the four corners of the outer circumference, each with four female screw holes 9b, and an irregularly shaped annular seal groove 9c having a curved portion and a straight edge portion is formed on the portion facing the cover member 8.

[0017] An irregularly shaped annular gasket 10, which seals the space between the opening 3a of the valve housing chamber 3 and the cover member 8, is housed and held in this seal groove 9c. Furthermore, as shown in Figure 4, the housing body 7 has a through hole 7b formed vertically through the center of the upper wall 7a opposite the cover member 8 in the axial direction, through which the rotating shaft 5 of the rotary valve 4 is inserted, and a bearing seal 27 is attached to the inner circumferential wall of the through hole 7b to seal the space between the through hole 7b and the rotating shaft 5.

[0018] Furthermore, as shown in Figures 2, 4, and 5, the housing body 7 has four radial ports, the first port 13, the second port 14, the third port 15, and the fourth port 16, integrally provided at equally spaced positions on the inner circumferential surface of the valve housing chamber 3. In addition, a fifth port 17 is provided at the center of the cover member 8, with one end opening into the interior of the valve housing chamber 3. Four seal housing grooves 7c, each formed in the same rectangular shape, are located at positions corresponding to the four end openings 13a to 16a of the first to fourth ports 13 to 16. The port seals 11 and the retainers 12 for the port seals 11, which are housed in these four seal housing grooves 7c, will be described later.

[0019] Furthermore, the inner circumferential surface of the valve housing chamber 3 has four bearing surfaces 3b that support the outer circumferential surface of the rotary valve 4, excluding the seal housing grooves 7c. As shown in Figure 5, these four bearing surfaces 3b are formed at approximately 90° positions in the circumferential direction of the inner circumferential surface of the valve housing chamber 3, and the circumferential width W of each of the first to fourth ports 13 to 16 is set to be greater than or equal to the combined opening width of the two opening ends 25a (25b) and 26a (26b) of the second flow path 25 and the third flow path 26, which will be described later. In other words, the two bearing surfaces 3b make it possible to simultaneously close both opening ends 25a, 25b of the second flow path 25 as shown in Figure 5, or to simultaneously close both opening ends 26a, 26b of the third flow path 26.

[0020] As shown in Figures 1 and 5, the four first to fourth ports 13 to 16 are composed of four nipple-shaped pipes 18 to 21, each integrally connected to the outer circumferential wall of the housing body 7. One end opening 13a to 16a of each pipe faces the four seal housing grooves 7c of the valve housing chamber 3, while the other end opening 13b to 16b faces the outside of the housing body 7. For example, the other end openings 13b to 16b are connected to equipment that requires the passage of cooling water via a circulation circuit such as a pipe (not shown). The four pipes 18 to 21 that constitute the four ports 13 to 16 are arranged in a cross shape in plan view, with approximately 90-degree intervals in the circumferential direction of the housing body 7. In other words, the first pipe 18 of the first port 13, the fourth pipe 21 of the fourth port 16, the second pipe 19 of the second port 14, the third pipe 20 of the third port 15, and the four seal housing grooves 7c through which the four one-end openings 13a to 16a of each pipe are opened are positioned at rotationally symmetrical (four-fold symmetry) positions equidistant from the axis of the rotary valve 4. Furthermore, as shown in Figure 4, the fifth port 17 is composed of a single nipple-shaped pipe 22 integrally connected to the lower surface of the cover member 8, with one end opening 17a facing the valve housing chamber 3. This one-end opening 17a is formed in a substantially funnel shape, with the valve housing chamber 3 side having the largest area, and is positioned opposite the lower surface of the bottom wall 4b of the rotary valve 4. On the other hand, the other end opening 17b of the fifth port 17 faces the outside of the housing body 7. For example, the other end opening 17b is connected to other equipment that requires the passage of cooling water via a circulation circuit such as a pipe (not shown). Furthermore, as will be described later, this fifth port 17 can communicate with any one of the first to fourth ports 13 to 16 depending on the rotational angle position of the rotary valve 4.

[0021] As shown in Figure 1, the housing body 7 has three support columns 7d integrally provided on the upper wall 7a, to which screws for fastening actuators such as electric motors 6 are screwed.

[0022] As shown in Figures 5 and 6, the seal housing groove 7c has a flat bottom surface 7e, and houses and arranges within the groove four port seals 11, which are sealing members that seal the space between the outer circumferential surface 4a of the rotary valve 4 and the four one-end openings 13a to 16a, and four retainers 12 that support the four port seals 11 inside each seal housing groove 7c.

[0023] Figure 6 is an enlarged view of section C in Figure 5, Figure 7 shows a seal member used in the fluid control valve of this embodiment, where Figure 7(a) is a circumferential side view of the seal member, Figure 7(b) is a view of the seal member from the axial side of the rotary valve 4, and Figure 7(c) is a top / bottom view of the seal member. Figure 8 shows a retainer used in the fluid control valve of this embodiment, where Figure 8(a) is a circumferential side view of the retainer, Figure 8(b) is a view of the retainer from the axial side of the rotary valve 4, and Figure 8(c) is a top / bottom view of the retainer.

[0024] As shown in Figures 2 and 7(b), the port seal 11 is formed in a substantially rectangular annular shape from, for example, ethylene propylene rubber (EPDM), with a through hole 11a in the center through which fluid flows. As shown in Figure 6, the port seal 11 has a sealing portion 11b, which is the tip that slides against the outer circumferential surface 4a of the rotary valve 4, and a pair of branched lip portions 11c, 11c that branch off from the sealing portion 11b and extend in the direction of the seal housing groove 7c. As shown in Figure 7(c), two of the sealing portions 11b that face each other in the axial direction of the rotary valve 4 are formed in a concave shape following the outer circumferential surface 4a of the rotary valve 4, while as shown in Figure 7(a), the other two that face each other in the circumferential direction of the rotary valve 4 are formed in a convex shape. The entire sealing portion 11b is in contact with the outer circumferential surface 4a of the rotary valve 4 with a predetermined pressure force.

[0025] As shown in Figure 6, the pair of branched lip portions 11c, 11c are formed in a bifurcated shape, widening towards the retainer 12 from the coupling base end closest to the outer circumferential surface 4a of the rotary valve 4. In addition, each branched lip portion 11c, 11c has stepped portions 11e, 11e facing in opposite directions at its respective tip (lower end in Figure 6), and these stepped portions 11e, 11e abut against the inner surface 12e of the seating surface portion 12b of the retainer 12, which will be described later.

[0026] As shown in Figures 2 and 8(b), the retainer 12 is formed from a synthetic resin material in a substantially rectangular annular shape, following the port seal 11, and has a hole 12a in the center that allows fluid to pass through, following the through hole 11a of the port seal 11. As shown in Figure 6, the retainer 12 has an outer surface 12d that sits on the bottom surface 7e of the seal housing groove 7c and a seating surface 12b, on which the outer surface 12d sits on the bottom surface 7e of the seal housing groove 7c, and a projection 12c that is provided at approximately the center of the width direction of the inner surface 12e facing the rotary valve 4 and protrudes into the space S between the branch lip portions 11c, 11c of the port seal 11.

[0027] As shown in Figure 6, each of the holes 12a is formed with an opening area larger than the opening areas of the first to fourth ports 13 to 16 of the housing body 7, and the inner peripheral edge 12f is set back by an amount L in Figure 6 compared to the inner peripheral edges 13c to 16c of the first to fourth ports 13 to 16.

[0028] As shown in Figure 6, the seat portion 12b forms a space S when the stepped portions 11e, 11e of the pair of branch lip portions 11c, 11c of the port seal 11 come into contact with the inner surface 12e. The projection 12c has a mountain-shaped cross-section, and when the port seal 11 is assembled, this projection 12c is positioned within the space S of the port seal 11, forming a gap S1 between it and the flat tip surface 12g, which is part of the remaining space S. Furthermore, the sides 12h, 12i of the projection 12c facing the branch lip portions 11c, 11c are formed as inclined surfaces that widen as they approach the seat portion 12b from the tip surface 12g, and the opposing inner surfaces of the branch lip portions 11c, 11c of the port seal 11 are close to or in contact with these sides 12h, 12i.

[0029] As shown in Figure 2, the cover member 8 is formed from a synthetic resin material into a plate shape with a substantially rectangular planar shape, and four bolt insertion holes 8a are formed through the four corners of its outer circumference. The shafts of four bolts 23, which are screwed into four female threaded holes 9b of the frame portion 9, are inserted through these four bolt insertion holes 8a, and the cover member 8 is fixed to the lower part of the housing body 7 by these four bolts 23.

[0030] As shown in Figures 2, 4, and 5, the rotary valve 4 is formed in a cylindrical shape with multiple internal flow paths, and a rotating shaft 5 is integrally provided at the axial center of the upper part. The rotating shaft 5 has a rotation-preventing portion 5a formed on the portion that protrudes from the upper surface of the rotary valve 4, which is connected to the motor shaft of the electric motor 6. The rotary valve 4's outer circumferential surface 4a is rotatably supported by the bearing surface 3b of the valve housing chamber 3. The rotary valve 4 is also rotationally driven to a predetermined rotation position via the electric motor 6 and a gear mechanism (not shown).

[0031] Furthermore, the rotary valve 4 has an arc-shaped groove 4c formed on the upper part where the rotating shaft 5 is located, and an annular projection 4d integrally provided on the outer edge of the lower disc-shaped bottom wall 4b. This annular projection 4d fits into an annular groove 8b formed on the outer circumference of the cover member 8 facing the housing body 7, thereby allowing the rotary valve 4 to rotate freely while restricting excessive radial movement.

[0032] Furthermore, the rotary valve 4 has a first flow path 24, a second flow path 25, and a third flow path 26 that open to the outer circumferential surface 4a. These first to third flow paths 24 to 3 and the first to fourth ports 13 to 4 are formed according to the rotational position of the rotary valve 4, which will be described later, and the four one-end openings 13a to 16a of the four ports 13 to 16 and the spaces between the first to third flow paths 24 to 3 are sealed by four port seals 11.

[0033] Furthermore, the rotary valve 4 has a circular hole 4e formed therein, which opens at a position that does not overlap with the axis of the bottom wall 4b. This circular hole 4e penetrates from the internal bottom wall 4b of the rotary valve 4 to the first flow path 24.

[0034] As shown in Figure 5, the first flow path 24 is formed in a substantially fan shape in cross-section, centered on the inner circumference on the axial side of the rotary valve 4, that is, on the side of the rotating shaft 5. A substantially rectangular outer opening end 24a is formed in the portion corresponding to the arc of this fan shape, when viewed from the outer circumference of the rotary valve 4. The first flow path 24 is in constant communication with one end opening 17a of the fifth port 17 via a circular hole 4e formed through the bottom wall 4b. Furthermore, the circumferential length of the outer opening end 24a, which is the length of the arc of the fan shape centered on the axial side of the rotary valve 4, is set to be approximately twice the size of the inner diameter D of the one end openings 13a to 16a of the ports 13 to 16. In addition, the axial dimension of the outer opening end 24a is set to be approximately the same size as the inner diameter D of the four one end openings 13a to 16a of the four ports 13 to 16.

[0035] The second channel 25 is positioned on one side of the first channel 24 in the circumferential direction, and is formed in a substantially V-shape in cross-section, with a uniform cross-sectional area throughout. Furthermore, the inner diameter D1 of the open ends 25a and 25b at the end of the second channel 25 is set to be approximately the same size as the inner diameter D of the four end openings 13a to 16a of the four ports 13 to 16 described above.

[0036] The third channel 26 is positioned on the other side of the first channel 24 in the circumferential direction, approximately symmetrically to the second channel 25 with the first channel 24 in between, and is formed in a substantially V-shape in cross-section, with a uniform cross-sectional area throughout. Furthermore, the inner diameter D1 of the open ends 26a and 26b at the end of the third channel 26 is set to be approximately the same size as the inner diameter D of the four single-end openings 13a to 16a of the four ports 13 to 16 mentioned above.

[0037] The electric motor 6 is controlled by an electronic control circuit (not shown) for forward and reverse rotation and stopping, and also controls the rotary valve 4 to a predetermined rotational angle position according to the temperature of each component. In other words, the electronic control circuit controls the forward and reverse rotation and stopping of the rotary valve 4 by the electric motor 6, and also controls its rotation to a predetermined rotational angle according to the switching mode required according to the operating conditions of the vehicle, thereby relatively connecting or disconnecting the first to fourth ports 13 to 16 and the first to third flow paths 24 to 26.

[0038] Furthermore, a pump (not shown) having a predetermined head is provided to pass fluid through one of the ports of the housing body 7, and a predetermined fluid pressure is applied by this pump to the fluid, the first to fifth ports 13 to 17, the first to third flow paths 24 to 26, and the port seal 11. [Assembly method of the fluid control valve of this embodiment] The following describes the work process of manufacturing the port seal 11 and the retainer 12 and assembling them into the seal housing groove 7c.

[0039] First, multiple retainers 12 with varying wall thicknesses on the seating surface 12b are formed. Furthermore, a standard value for the compression allowance of the port seal 11 is determined in advance through experimental or analytical investigation to obtain an appropriate pressure contact force against the outer surface 4a of the rotary valve 4. The process includes the steps of: measuring the clearance width between the seal housing groove 7c of the housing body 7 and the outer circumferential surface 4a of the rotary valve 4; placing the port seal 11 on a surface plate that provides a reference plane for measurement, and measuring the length from the reference plane in the free state of the port seal 11 to the tip (tip edge) of the seal portion 11b of the port seal 11; calculating the required seating thickness, which is the difference between the measured clearance width dimension plus the standard value of the compression allowance of the port seal 11 and the measured length dimension of the port seal 11; selecting a retainer 12 from among the plurality of retainers 12 that has a seating portion 12b with a wall thickness dimension that matches the required seating thickness; and assembling the retainer 12 and the port seal 11 into the seal housing groove 7c with the port seal 11 in contact with the selected retainer 12. Furthermore, the reference plate that provides the reference plane for the aforementioned dimensional measurement is made of a highly rigid material such as iron, stone, or ceramic that has been planarized according to well-known precision standards. [Effects of the fluid control valve of this embodiment] Figure 9 is a schematic diagram showing multiple switching modes by the fluid control valve of this embodiment, where (a) to (h) are explanatory diagrams that switch the fluid circuit by sequentially rotating the rotation position of the rotary valve from 0° in 45° increments.

[0040] In the first mode shown in Figure 9(a), the rotary valve 4 is in a rotational position of 0°, which is the initial position. In the initial position, the fourth port 16 and the fifth port 17 are in communication through the circular hole 4e via the first flow path 24, and the first port 13 and the second port 14 are in communication via the third flow path 26. At this time, the opening 15a at one end of the third port 15 is blocked by the outer circumferential surface 4a of the rotary valve 4. The opening ends 25a and 25b of the second flow path 25 are closed by two bearing surfaces 3b, 3b.

[0041] In the second mode shown in Figure 9(b), the rotary valve 4 is rotated 45° clockwise from its initial position in Figure 9(a) by the electric motor 6. As a result, the fourth port 16 and the fifth port 17 remain in communication, and the third port 15 and the first port 13 are connected by the second flow path 25. At this time, the opening 14a at one end of the second port 14 is blocked by the outer circumferential surface 4a of the rotary valve 4. The opening ends 26a and 26b of the third flow path 26 are closed by two bearing surfaces 3b, 3b.

[0042] In the third mode shown in Figure 9(c), the rotary valve 4 rotates another 45° clockwise from the rotation position shown in Figure 9(b) (90° from the initial position). As a result, the third port 15 and the fifth port 17 are connected by the first flow path 24, and the second port 14 and the fourth port 16 are connected by the third flow path 26. At this time, the opening 13a at one end of the first port 13 is blocked by the outer circumferential surface 4a of the rotary valve 4. The opening ends 25a and 25b of the second flow path 25 are closed by two bearing surfaces 3b, 3b.

[0043] In the fourth mode shown in FIG. 9(d), the rotary valve 4 rotates further 45° clockwise (135° from the initial position) from the rotational position in FIG. 9(c). Then, the first flow path 24 maintains the communication state between the third port 15 and the fifth port 17, and the second flow path 25 causes the first port 13 and the second port 14 to communicate with each other. At this time, for the fourth port 16, the one-end opening 16a is blocked by the outer peripheral surface 4a of the rotary valve 4. Also, the third flow path 26 is closed by the two bearing surfaces 3b, 3b.

[0044] In the fifth mode shown in FIG. 9(e), the rotary valve 4 rotates further 45° clockwise (180° from the initial position) from the rotational position in FIG. 9(d). Then, the first flow path 24 causes the first port 13 and the fifth port 17 to communicate with each other, and the third flow path 26 causes the third port 15 and the fourth port 16 to communicate with each other. At this time, for the second port 14, the one-end opening 14a is blocked by the outer peripheral surface 4a of the rotary valve 4. Also, the second flow path 25 is closed by the two bearing surfaces 3b, 3b.

[0045] In the sixth mode shown in FIG. 9(f), the rotary valve 4 rotates further 45° clockwise (225° from the initial position) from the rotational position in FIG. 9(e). Then, the first flow path 24 maintains the communication between the first port 13 and the fifth port 1, and the second flow path 25 causes the second port 14 and the fourth port 16 to communicate with each other. At this time, for the third port 15, the one-end opening 15a is blocked by the outer peripheral surface 4a of the rotary valve 4. Also, the third flow path 26 is closed by the two bearing surfaces 3b, 3b.

[0046] In the seventh mode shown in FIG. 9(g), the rotary valve 4 rotates further 45° clockwise (270° from the initial position) from the rotational position in FIG.. Then, the first flow path 24 causes the second port 14 and the fifth port 17 to communicate with each other, and the third flow path 26 causes the first port 13 and the third port 15 to communicate with each other. At this time, for the fourth port 16, the one-end opening 16a is blocked by the outer peripheral surface 4a of the rotary valve 4. Also, the second flow path 25 is closed by the two bearing surfaces 3b, 3b.

[0047] In the eighth mode shown in FIG. 9(h), the rotary valve 4 rotates further 45° clockwise (315° from the initial position) from the rotational position in FIG. 9(g). Then, the second port 14 and the fifth port 17 are kept in communication by the first flow path 24, and the third port 15 and the fourth port 16 are in communication by the second flow path 25. At this time, for the first port 13, the one end opening 13a is blocked by the outer peripheral surface 4a of the rotary valve 4. Further, the third flow path 26 is closed by the two bearing surfaces 3b, 3b.

[0048] The rotary valve 4 can rotate further 45° clockwise from the rotational position in FIG. 9(h). Then, the rotary valve 4 returns to the initial position shown in FIG. 9(a). At this time, it is switched to the fluid circuit of the first mode described above.

[0049] It is also possible to rotate the rotary valve 4 45° counterclockwise, which is opposite to the above description, via the electric motor 6. That is, the rotary valve 4 can also switch the fluid circuit in the order of FIGS. 9(a), (h), (g), (f), (e), (d), (c), (b), which is the reverse order of the above description.

[0050] As described above, in the present embodiment, by providing the three flow paths of the first flow path 24, the second flow path 25, and the third flow path 26, the rotational angle position of the rotary valve 4 is controlled to selectively perform the communication and blocking of the first to fifth ports 13 to 16, thereby switching the flow path can be achieved. Therefore, since it is possible to obtain up to eight various switching patterns with one fluid control valve 1, the versatility for, for example, electric vehicles and the like is increased.

[0051] Furthermore, in this embodiment, the port seal 11, which is positioned between the outer circumferential surface 4a of the rotary valve 4 and the seal housing groove 7c, has a pair of branched lip portions 11c, 11c that branch off from the seal portion 11b that slides against the outer circumferential surface 4a of the rotary valve 4 and extend toward the seal housing groove 7c. By positioning a retainer 12 with a seating surface portion 12e between the branched lip portions 11c, 11c and the seal, sliding can be created at the ends of the pair of branched lip portions 11c, 11c. Therefore, by positioning a retainer 12 with a seating surface portion 12e, it is possible to facilitate the expansion of the branched lip portions 11c, 11c of the port seal 11 from their free state and to suppress buckling of the pair of branched lip portions 11c, 11c from their free state. As a result, it is possible to reduce the tension force of the port seal 11 between the outer circumferential surface 4a of the rotary valve 4 and the seal housing groove 7c.

[0052] Therefore, the generation of excessive pressure force on the outer surface 4a of the rotary valve 4 by the sealing portion 11b of the port seal 11 is suppressed, and an appropriate pressure force is obtained. In addition, wear of the port seal 11 is suppressed, improving durability, and smooth rotation of the rotary valve 4 can be achieved.

[0053] Furthermore, in this embodiment, the projection 12c of the retainer 12 is positioned and held between the pair of branched lip portions 11c, 11c of the port seal 11. As a result, buckling of the pair of branched lip portions 11c, 11c from their free state can be suppressed. Therefore, there is no excessive increase in tension due to buckling of the port seal 11, and the seal portion 11b contacts the outer circumferential surface 4a of the rotary valve 4 with an appropriate pressure force. As a result, while ensuring high sealing performance by the port seal 11, the sliding resistance to the rotary valve 4 can be reduced, and smooth rotation can be obtained.

[0054] In particular, since a gap S1 is formed between the seal portion 11b and the tip surface 12g of the projection 12c of the retainer 12, the occurrence of excessive compressive strain caused by the seal portion 11b being sandwiched between the outer circumferential surface 4a of the rotary valve 4 and the tip surface 12g of the projection 12c of the retainer 12 is suppressed. Furthermore, due to the presence of the gap S1, the coupling base ends on the rotary valve 4 side of the pair of branched lip portions 11c, 11c are configured to be relatively low rigidity, making them easy to expand. Therefore, the seal portion 11b does not excessively press against the outer circumferential surface 4a of the rotary valve 4, and contacts with an appropriate pressure force. As a result, while ensuring high sealing performance by the port seal 11, sliding resistance to the rotary valve 4 can be reduced, and smooth rotation can be obtained.

[0055] Furthermore, even if a pressure difference occurs between the inner and outer circumferences of the port seal 11 due to fluid pressure in the valve housing chamber 3 or other factors, the projection 12c of the retainer 12 prevents the port seal 11 from unintentionally tilting or oscillating excessively. In other words, the retainer 12 provides a stable position for the sealing portion of the port seal 11, thereby suppressing a decrease in sealing performance against the outer surface 4a of the rotary valve 4 and preventing the generation of excessive pressure.

[0056] Furthermore, as shown in Figures 5 and 6 above, the inner peripheral edge 12f of the hole 12a on the inside of the seating surface 12b is formed at a position set back by L from the inner peripheral edges 13c to 16c of the four openings 13a to 16a of the four ports 13 to 16. Therefore, the seating surface 12b is not affected by the pressure of the fluid flowing through the four ports 13 to 16, and the retainer 12 is stably housed and held within the seal housing groove 7c. As a result, the port seal 11 is stably held by the retainer 12, and thus can exhibit a high sealing function.

[0057] Furthermore, in this embodiment, when attaching the port seal 11 to the seal housing groove 7c of the housing body 7, the port seal 11 is first fitted onto the projection 12c of the retainer 12 and brought into contact with it. At this time, the projection 12c of the retainer 12 is positioned and held between the pair of branch lip portions 11c, 11c of the port seal 11. As a result, the port seal 11 can be assembled into the seal housing groove 7c while being stably supported by the retainer 12. This makes the assembly work of the port seal 11 easier. In other words, since the retainer 12 can be used as a guide when assembling into the seal housing groove 7c, the port seal 11 can be engaged with and disengaged from the housing body 7 with a single touch. This makes the assembly work easier.

[0058] Furthermore, by adjusting the thickness of the seating surface 12b of the retainer 12, it becomes possible to arbitrarily and appropriately adjust the contact force when the sealing portion 11b contacts the outer circumferential surface 4a of the rotary valve 4. As a result, a decrease in the sealing performance of the port seal 11 and the generation of excessive contact force can be suppressed.

[0059] Furthermore, since the retainer 12 is formed of a synthetic resin material that includes a friction-reducing layer that provides sliding properties when in contact with the seal housing groove 7c or the port seal 11, when assembling the port seal 11 together with the retainer 12 into the seal housing groove 7c of the housing body 7, the outer surface 12d of the seating surface 12b can be smoothly slid into contact with the seal housing groove 7c. This makes the assembly work of the port seal 11 and the retainer 12 into the seal housing groove 7c easier. [Second Embodiment] Figure 10 shows a second embodiment of the present invention, in which the structure of the retainer 12 is modified. The retainer 12 has notches 30 formed by cutting out the four circumferential corner portions of the projection 12c, which become part of the inner surface 12e of the seating surface 12b, and the projection 12c has four linear projections 12c' intermittently formed in the circumferential direction.

[0060] In this way, by forming four notches 30 at the corners of the projection 12c, when fitting the aforementioned nearly square, annular port seal 11 onto the projection 12c, it is possible to assemble it only onto the straight projection 12c' without having to worry about the fit of the corners, which are difficult to assemble due to their high bending rigidity. Therefore, the ease of assembling the port seal 11 to the retainer 12 is improved.

[0061] Furthermore, by forming a notch 30 in the retainer 12, the rigidity of the corner portion of the port seal 11 after it has been assembled to the retainer 12 is reduced. As a result, the rigidity of the corner portion of the port seal 11 that is not fitted onto the projection 12c becomes approximately the same as the rigidity of the straight portion of the port seal 11 that is still fitted onto the projection 12c. In other words, it becomes possible to reduce the tension force at the corner portion of the port seal 11 between the outer circumferential surface 4a of the rotary valve 4 and the seal housing groove 7c, making it the same as the tension force at the straight portion of the port seal 11. As a result, the pressure force when the seal portion 11b contacts the outer circumferential surface 4a of the rotary valve 4 can be made appropriate over the entire circumference of the nearly rectangular, annular port seal 11. Therefore, even at the corner portion of the port seal 11, the seal portion 11b does not press excessively against the outer circumferential surface 4a of the rotary valve 4, and contacts with an appropriate pressure force. As a result, high sealing performance can be ensured around the entire circumference of the nearly rectangular, annular port seal 11 while reducing the sliding resistance to the rotary valve 4, resulting in smooth rotation of the rotary valve 4. The other configurations are the same as in the first embodiment, and therefore the same effects can be obtained. [Third Embodiment] Figure 11 shows a third embodiment of the present invention, in which the basic configuration is the same as that of the first embodiment, but the projection 12c of the retainer 12 and the structure of the port seal 11 have been changed.

[0062] Specifically, a V-shaped notch 31 is formed along the circumferential direction on the tip surface 12g of the projection 12c of the retainer 12. Between the pair of branched lip portions 11c, 11c of the port seal 11, there is a protrusion 32 whose tip portion 32a fits into the tip portion of the notch 31. A gap S1 is also formed between the protrusion 32 and the notch 31.

[0063] According to this embodiment, the port seal 11 is supported by the projection 12c of the retainer 12 via the bifurcated branched lip portions 11c, 11c, and the tip 32a of the convex portion 32 is fitted into the notch 31 of the retainer 12 for support, thereby suppressing unintended excessive tilting or swaying of the port seal 11. As a result, the port seal 11 is more stably supported by the retainer 12, which suppresses a decrease in sealing performance against the outer circumferential surface 4a of the rotary valve 4 and the generation of excessive pressure forces, while enabling smooth rotation of the rotary valve 4.

[0064] The present invention is not limited to the configuration of the above-described embodiment. For example, the port seal 11 is not limited to the V-shaped cross-section shown in Figure 6 or Figure 11, but may be realized in a U-shaped cross-section or an arc-shaped cross-section. Furthermore, the retainer 12 and the port seal 11 may be realized by appropriately combining the structures of the first, second, and third embodiments described above. For example, the convex portion 32 of the port seal 11 and the notched portion 31 of the retainer 12 described in the third embodiment may not be provided in the portion corresponding to the corner portion of the port seal 11, but only in the portion corresponding to the straight portion of the port seal 11.

[0065] Furthermore, although the fluid control valve in the above embodiment was used to switch the flow path of the vehicle's cooling water, it is not limited to this and can be applied to ships or other equipment, for example, and can also be applied to oil or other liquids in addition to cooling water.

[0066] Furthermore, it is also possible to reduce frictional resistance when the retainer 12 comes into contact with the seal housing groove 7c or port seal 11 by forming, for example, a friction-reducing layer with sliding properties on the retainer 12.

[0067] Furthermore, it is possible to reduce frictional resistance when the port seal 11 comes into contact with the rotary valve 4 or retainer 12 by forming a friction-reducing layer material, such as a film, on the port seal 11.

[0068] 1... Fluid control valve, 2... Valve housing, 3... Valve housing chamber, 4... Rotary valve, 4a... Outer surface, 5... Rotating shaft, 6... Electric motor (actuator), 7... Housing body (valve housing), 8... Cover member (valve housing), 11... Port seal, 11a... Through hole, 11b... Seal part, 11c・11c... Branch lip part, 11e・11e... Stepped part, 12... Retainer, 12a... Hole part, 12b... Seat surface part, 12c... Projection part, 12d... Outer surface, 12e... Inner surface, 12f... Inner periphery, 12h, 12i... Both sides, 13-16... 1st to 4th ports (radial ports), 17... 5th port, 18-22... 1st to 5th piping, 24... 1st flow path, 25... 2nd flow path, 26... 3rd flow path, 27-29... Bypass passage.

Claims

1. A fluid control valve comprising: a valve housing having a valve housing chamber inside and at least one radial port formed to open on the inner circumferential surface of the valve housing chamber; a rotary valve rotatably housed in the valve housing chamber; an actuator for rotationally driving the rotary valve; an annular sealing member housed in an annular sealing groove formed at the opening end of the radial port of the valve housing to seal the space between the outer circumferential surface of the rotary valve and the valve housing chamber; and a retainer formed in an annular shape to hold the sealing member inside the sealing groove, wherein the sealing member has a sealing portion that slides against the outer circumferential surface of the rotary valve and a pair of branched lip portions that branch off from the sealing portion and extend in the direction of the sealing groove, The fluid control valve is characterized in that the retainer has an annular seating surface whose outer surface sits on the bottom surface of the seal housing groove, and whose inner surface abuts the tips of the pair of branched lip portions, forming a space between the pair of branched lip portions and the annular seating surface, and a projection that protrudes from the annular seating surface into the space.

2. A fluid control valve according to claim 1, wherein the projection is formed in a mountain shape in cross-section.

3. A fluid control valve according to claim 1, characterized in that a gap is formed between the projection and the pair of branched lip portions.

4. A fluid control valve according to claim 1, characterized in that the outer surface of the seating surface is in close contact with the flat bottom surface of the seal housing groove around its entire circumference.

5. A fluid control valve according to claim 1, characterized in that the inner peripheral edge of the hole formed on the inside of the seating surface is set back from the inner peripheral edge of the opening of the radial port.

6. A fluid control valve according to claim 1, characterized in that the projection of the retainer has a plurality of notches formed in a part of its circumferential direction.

7. A fluid control valve according to claim 1, wherein the retainer is formed of a synthetic resin material that includes a friction-reducing layer having sliding properties when in contact with the seal housing groove or the seal member.

8. A fluid control valve according to claim 1, characterized in that a notch is formed at the tip of the projection of the retainer, and the sealing member is provided with a stepped portion that loosely fits into the notch.

9. A fluid control valve according to claim 1, characterized in that the sealing member is provided with a friction-reducing layer that reduces frictional resistance when in contact with the rotary valve or the retainer.

10. A method for assembling a fluid control valve according to claim 1, comprising: measuring the clearance width between the seal housing groove and the outer circumferential surface of the rotary valve; placing the seal member on a surface plate that provides a reference plane and measuring the length dimension from the reference plane to the tip edge of the seal member in a free state of the seal member; calculating the required seating surface thickness, which is the difference between the measured clearance width dimension plus a predetermined compressive allowance of the seal member and the measured length dimension of the seal member; selecting a retainer that matches the required seating surface thickness from a plurality of retainers that have been manufactured in advance with different thicknesses of the seating surface portion; and assembling the retainer and the seal member into the seal housing groove with the seal member in contact with the selected retainer.

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