Passage switching valve

Abstract

To secure a sealing property and reduce slide resistance in a compatible manner.SOLUTION: A passage switching valve 1 comprises: a housing 10 which includes a cylindrical inner wall part 12 and in which a plurality of ports 13 is opened while being unevenly distributed in a part in a circumferential direction; and a plurality of valve bodies 30 which is stored within the housing 10 rotatably around a center axis C, includes seal surfaces 31d, 32d, 33d and 34d in slide contact with the inner wall part 12 and switches communication states of the plurality of ports 13. The inner wall part 12 includes a first inner wall part 12a in which the plurality of ports 13 is provided and a second inner wall part 12b which is opposed to the first inner wall part 12a while interposing the center axis C therebetween and in which no port 13 is provided. The second inner wall part 12b includes a diameter expanded part 17 which has a portion of a larger radius from the center axis C than the first inner wall part 12a and of which the radius from the center axis C is changed in an axial direction or a radial direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a flow path switching valve that switches a flow path of a fluid. [Background technology]

[0002] Patent Document 1 discloses a control valve (flow path switching valve) that includes a cylindrical main body (housing) having a valve cavity, a valve core that is disposed within the valve cavity and driven to rotate, and a sealing member that is formed in an arc along the radial direction of the valve core and disposed between the valve core and the valve cavity. In this control valve, the sealing member has two through holes along the circumferential direction and is provided on part of the circumference so as to seal only the periphery of the through holes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 218406 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the control valve described in Patent Document 1, the seal member is formed separately from the main body and is compressed radially between the valve core and the valve cavity to ensure sealing around the through hole, which raises concerns about deterioration of the seal member due to sliding of the valve core.

[0005] The present invention has been made in view of the above points, and has an object to achieve both ensuring sealing performance and reducing sliding resistance. [Means for solving the problem]

[0006] According to one aspect of the present invention, a flow path switching valve includes a housing having a cylindrical inner wall portion in which a plurality of ports open and are unevenly distributed in a circumferential direction, and a plurality of valve bodies that are rotatably accommodated inside the housing around a central axis, have sealing surfaces that slide against the inner wall portion, and switch the communication state of the plurality of ports, wherein the inner wall portion has a first inner wall portion in which the plurality of ports are provided, and a second inner wall portion that faces the first inner wall portion across the central axis and in which no ports are provided, and the second inner wall portion has an expanded diameter portion that has a portion with a larger radius from the central axis than the first inner wall portion, and whose radius from the central axis changes in the axial or radial direction. [Effects of the Invention]

[0007] According to the above aspect, the inner wall portion of the housing has a first inner wall portion having a plurality of ports and a second inner wall portion facing the first inner wall portion across the central axis and having no ports. The second inner wall portion has an expanded diameter portion having a portion with a larger radius from the central axis than the first inner wall portion, and the radius from the central axis varies in the axial or radial direction. Therefore, the sealing surface of the valve body slides against the first inner wall portion, making it possible to switch the communication state of the plurality of ports while ensuring sealing, and the provision of the expanded diameter portion reduces sliding resistance between the second inner wall portion and the valve body. Therefore, it is possible to achieve both ensuring sealing performance and reducing sliding resistance. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the appearance of a flow path switching valve according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of FIG. [Figure 3] FIG. 3 is a perspective view of the valve body and the rotary shaft. [Figure 4] FIG. 4 is a perspective view of the lid. [Figure 5] FIG. 5 is a perspective view of the rotating shaft and the biasing member. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7]FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a perspective view illustrating a modified example of the housing. [Figure 10] FIG. 10 is a cross-sectional view of a flow path switching valve according to a modified example of the embodiment of the present invention. [Figure 11] FIG. 11 is an enlarged view of the main part in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] A flow path switching valve 1 according to an embodiment of the present invention will be described below with reference to the drawings.

[0010] First, the overall configuration of the flow path switching valve 1 will be described with reference to FIGS.

[0011] Fig. 1 is an external perspective view of the flow path switching valve 1. Fig. 2 is an exploded perspective view of Fig. 1. Fig. 3 is a perspective view of the valve body 30 and the rotary shaft 60. Fig. 4 is a perspective view of the cover member 20 serving as the cover portion. Fig. 5 is a perspective view of the rotary shaft 60 and a plurality of coil springs 70 serving as biasing members.

[0012] 1 to 3, the flow path switching valve 1 includes a housing 10, a valve element 30, a rotary shaft 60, a plurality of coil springs 70, and an actuator 80. The flow path switching valve 1 switches the path through which cooling water flows as a fluid by rotating the valve element 30 within the housing 10. Note that the fluid flowing through the flow path switching valve 1 may be other liquids instead of cooling water.

[0013] Hereinafter, the direction along the central axis C of the housing 10 (the central axis of rotation of the valve body 30 and the rotating shaft 60) will be referred to as the "axial direction," the direction from the central axis C of the housing 10 toward the outer diameter will be referred to as the "radial direction," and the direction in which the valve body 30 rotates within the housing 10 will be referred to as the "rotational direction" or "circumferential direction."

[0014] 1, the housing 10 has a main body 11 and a cover member 20. The housing 10 is molded using a mold and a resin material or the like.

[0015] 2, the main body 11 is formed in a generally cylindrical shape with a bottom. The main body 11 has an inner wall 12, a plurality of ports 13, a bottom surface 14 (see FIG. 6) as a bottom, and a connection portion 15.

[0016] The inner wall portion 12 is the cylindrical inner circumferential surface of the main body portion 11. The inner wall portion 12 is formed into a smoothly curved surface so that the valve body 30 can slide in contact with it. A plurality of ports 13 are opened in the inner wall portion 12 and are unevenly distributed in one part of the circumferential direction. The inner wall portion 12 will be described in detail later with reference to Figures 6 to 8.

[0017] The ports 13 communicate between the inner periphery and the outer periphery of the main body 11. The ports 13 are arranged so that their communication state is switched when the valve element 30 rotates a predetermined angle around the central axis C. A plurality of ports 13 are arranged in two rows in the circumferential direction of the housing 10. The ports 13 include a first port 13a, a second port 13b, a third port 13c, a fourth port 13d, a fifth port 13e, a sixth port 13f, a seventh port 13g, and an eighth port 13h.

[0018] The first port 13a and the second port 13b are arranged in a line in the circumferential direction to form a first layer L1 as the first stage. The third port 13c and the fourth port 13d are arranged in a line in the circumferential direction to form a second layer L2 as the second stage. The fifth port 13e and the sixth port 13f are arranged in a line in the circumferential direction to form a third layer L3 as the third stage. The seventh port 13g and the eighth port 13h are arranged in a line in the circumferential direction to form a fourth layer L4 as the fourth stage. That is, the multiple ports 13 are arranged in four stages in the axial direction: the first layer L1, the second layer L2, the third layer L3, and the fourth layer L4. In addition, a fifth layer (not shown), a sixth layer (not shown), etc. may be arranged in a line.

[0019] The first port 13a, the third port 13c, the fifth port 13e, and the seventh port 13g are arranged in a row in the axial direction. The second port 13b, the fourth port 13d, the sixth port 13f, and the eighth port 13h are arranged in a row in the axial direction. That is, the multiple ports 13 are arranged in a matrix of 4 rows and 2 columns.

[0020] The bottom surface portion 14 covers one axial end (here, the bottom) of the main body portion 11. The bottom surface portion 14 rotatably supports the end of the shaft portion 61 of the rotating shaft 60 via a cylindrical collar 67. The bottom surface portion 14 is provided integrally with the main body portion 11, but may also be attached to the main body portion 11 as a separate member.

[0021] The connection parts 15 connect each port 13 to external piping. The connection parts 15 are provided so as to divide the cooling water flow path into a 2x4 grid pattern. The end faces of the connection parts 15 are formed flat. A connection box (not shown) in which external piping is aggregated is connected to the connection parts 15 via a 2x4 grid-shaped sealing member (not shown).

[0022] 1 and 2, the cover member 20 closes the opening of the main body 11. As shown in Fig. 4, the cover member 20 has an end plate portion 21, a cylindrical portion 22, an arc portion 23, and a shaft support portion 24.

[0023] The end plate portion 21 is formed in a flat plate shape and covers the other axial end portion of the main body portion 11. The end plate portion 21 closes the other end portion of the main body portion 11 and, together with the inner wall portion 12 and the bottom surface portion 14, defines a space in which the valve body 30 is housed.

[0024] The cylindrical portion 22 is formed in a cylindrical shape with one end fixed to the end plate portion 21. A circular seal member 25 (see FIG. 1) serving as a sealing member is provided on the outer periphery of the cylindrical portion 22. The cylindrical portion 22 seals the inside and outside of the housing 10 by sandwiching and fixing the seal member 25 between the cylindrical portion 22 and the main body portion 11. The cylindrical portion 22 has an arc portion 23 formed in an arc shape along the inner wall portion 12 and protruding toward the inside of the main body portion 11.

[0025] The arc portion 23 protrudes in a part of the axial direction of the main body 11. The arc portion 23 is in sliding contact with a part of sealing surfaces 31d, 32d, 33d, and 34d (described later) of the valve body 30. The arc portion 23 will be described in detail later with reference to Figs. 6 to 8.

[0026] The shaft support portion 24 extends in the axial direction from the inner surface, where the cylindrical portion 22 is formed, to the outer surface of the end plate portion 21. The shaft support portion 24 is formed in a substantially cylindrical shape. The shaft portion 61 of the rotating shaft 60 is inserted into the shaft support portion 24. The shaft support portion 24 rotatably supports the shaft portion 61 via a cylindrical collar 66 (see FIG. 2).

[0027] As shown in FIGS. 2 and 3 , the valve element 30 is accommodated inside the housing 10 and is rotatable around the central axis C. The valve element 30 switches the communication state of the multiple ports 13. The valve element 30 has a first valve element 31, a second valve element 32, a third valve element 33, and a fourth valve element 34. The first valve element 31, the second valve element 32, the third valve element 33, and the fourth valve element 34 are movable in the radial direction relative to the central axis C of the housing 10 and are biased by a coil spring 70 toward the inner wall portion 12, which is the inner circumferential surface of the housing 10. The first valve element 31, the second valve element 32, the third valve element 33, and the fourth valve element 34 are rotatable such that their rotational stopping positions are different from one another.

[0028] The first valve body 31 is formed in a generally arc shape with a central angle of approximately 110°. The first valve body 31 is provided across the first layer L1 to the fourth layer L4. The first valve body 31 has at least one first communication portion 31a that connects the multiple ports 13 in the axial direction across two or more layers L1 to L4, one second communication portion 31b that connects the multiple ports 13 in the circumferential direction, and one blocking portion 31c that blocks one port 13 from communicating with another port 13.

[0029] The first valve body 31 is softer than the main body 11 of the housing 10 and softer than the rotary shaft 60. The first valve body 31 has a seal surface 31d that comes into sliding contact with the inner wall 12. The seal surface 31d is pressed against the inner wall 12 by the biasing force of the coil spring 70, thereby forming a seal between the first valve body 31 and the inner wall 12.

[0030] The second valve body 32 is provided at a position facing the first valve body 31 with the rotation axis 60 (central axis C) as the center. The second valve body 32 is formed in a generally arc shape with a central angle of approximately 110°. The second valve body 32 is provided across the first layer L1 to the fourth layer L4. The second valve body 32 has at least one first communication portion 32a that connects the multiple ports 13 in the axial direction across two or more layers L1 to L4, one second communication portion 32b that connects the multiple ports 13 in the circumferential direction, and one blocking portion 32c that blocks communication between ports 13 and other ports 13.

[0031] The second valve body 32 is softer than the main body 11 of the housing 10 and softer than the rotary shaft 60. The second valve body 32 has a seal surface 32d that comes into sliding contact with the inner wall 12. The seal surface 32d is pressed against the inner wall 12 by the biasing force of the coil spring 70, thereby forming a seal between the second valve body 32 and the inner wall 12.

[0032] The circumferential size of the first valve body 31 and the second valve body 32 is formed to be large enough to allow three ports 13 to be arranged in the circumferential direction. Specifically, the first valve body 31 and the second valve body 32 have a first row D1, a second row D2, and a third row D3. The first valve body 31 and the second valve body 32 can switch their communication states between a first communication state in which the first row D1 and the second row D2 are communicated with the ports 13, and a second communication state in which the second row D2 and the third row D3 are communicated with the ports 13. This allows switching between two communication states with a single valve body 30, so the number of valve bodies 30 can be reduced relative to the number of communication states that can be switched.

[0033] The third valve body 33 is provided between the first valve body 31 and the second valve body 32 in the circumferential direction. The third valve body 33 is formed in a generally arc shape with a central angle of approximately 70°. The third valve body 33 is provided across the first layer L1 to the fourth layer L4. The third valve body 33 has at least one second communication portion 33b that connects the multiple ports 13 in the circumferential direction, and at least one blocking portion 33c that blocks communication between the ports 13 and other ports 13. The third valve body 33 may further be provided with a first communication portion (not shown) that connects the multiple ports 13 in the axial direction across two or more layers L1 to L4.

[0034] The third valve body 33 is softer than the main body 11 of the housing 10 and softer than the rotary shaft 60. The third valve body 33 has a seal surface 33d that comes into sliding contact with the inner wall 12. The seal surface 33d is pressed against the inner wall 12 by the biasing force of the coil spring 70, thereby sealing the gap between the third valve body 33 and the inner wall 12.

[0035] The fourth valve body 34 is provided between the second valve body 32 and the first valve body 31 in the circumferential direction. The fourth valve body 34 is provided at a position facing the third valve body 33 with the rotation axis 60 (central axis C) as the center. The fourth valve body 34 is formed in a substantially arc shape with a central angle of approximately 70°. The fourth valve body 34 is provided across the first layer L1 to the fourth layer L4. The fourth valve body 34 has at least one first communication portion 34a that connects the multiple ports 13 in the axial direction across two or more layers L1 to L4, one second communication portion 34b that connects the multiple ports 13 in the circumferential direction, and one blocking portion 34c that blocks communication between ports 13 and other ports 13.

[0036] The fourth valve body 34 is softer than the main body 11 of the housing 10 and softer than the rotary shaft 60. The fourth valve body 34 has a seal surface 34d that comes into sliding contact with the inner wall 12. The seal surface 34d is pressed against the inner wall 12 by the biasing force of the coil spring 70, thereby forming a seal between the fourth valve body 34 and the inner wall 12.

[0037] The third valve body 33 and the fourth valve body 34 are formed with a circumferential size that allows two ports 13 to be arranged in the circumferential direction. Specifically, the third valve body 33 and the fourth valve body 34 have a first row D1 and a second row D2. The third valve body 33 and the fourth valve body 34 can be switched to a communication state in which the first row D1 and the second row D2 communicate with the port 13.

[0038] The direction in which the first valve body 31 and the second valve body 32 face each other is perpendicular to the direction in which the third valve body 33 and the fourth valve body 34 face each other. That is, the first valve body 31, the third valve body 33, the second valve body 32, and the fourth valve body 34 are arranged in order with a phase difference of 90° in the rotation direction.

[0039] 2 and 3, the rotary shaft 60 extends in the axial direction of the housing 10. The rotary shaft 60 connects the first valve body 31 and the second valve body 32 so that they can move in opposing directions, and connects the third valve body 33 and the fourth valve body 34 so that they can move in opposing directions. The rotary shaft 60 switches the rotational positions of the first valve body 31, the second valve body 32, the third valve body 33, and the fourth valve body 34 by rotating.

[0040] As shown in FIG. 5, the rotary shaft 60 has a shaft portion 61 formed in a substantially cylindrical shape, and a valve element support portion 62 formed in a substantially rectangular parallelepiped shape.

[0041] The shaft 61 is rotatably supported by the lid member 20 via a cylindrical collar 66 (see FIG. 2). A pair of sealing members 65 are provided around the shaft 61. The gap between the shaft 61 and the lid member 20 is sealed by the sealing members 65.

[0042] The end of the valve element support portion 62 that faces the cover member 20 is provided continuous with the shaft portion 61 in the axial direction. The valve element support portion 62 is formed integrally with the shaft portion 61. The end of the valve element support portion 62 that faces the bottom surface portion 14 is rotatably supported on the bottom surface portion 14 of the housing 10 via a cylindrical collar 67 (see FIG. 2). The valve element support portion 62 has a first flat surface portion 62a, a second flat surface portion 62b, a third flat surface portion 62c, and a fourth flat surface portion 62d.

[0043] The first flat surface portion 62a is provided opposite the first valve body 31 and supports the first valve body 31 via a plurality of coil springs 70.

[0044] The second flat surface portion 62b is provided at a position opposite to the first flat surface portion 62a across the central axis C. The second flat surface portion 62b is provided opposite the second valve body 32 and supports the second valve body 32 via a plurality of coil springs 70.

[0045] The third flat surface portion 62c is provided between the first flat surface portion 62a and the second flat surface portion 62b. The third flat surface portion 62c is provided opposite the third valve body 33 and supports the third valve body 33 via a plurality of coil springs 70.

[0046] The fourth flat surface portion 62d is provided between the second flat surface portion 62b and the first flat surface portion 62a. The fourth flat surface portion 62d is provided opposite the fourth valve body 34 and supports the fourth valve body 34 via a plurality of coil springs 70.

[0047] The first and second flat portions 62a and 62b are formed wider than the third and fourth flat portions 62c and 62d in the circumferential direction of the inner wall portion 12. That is, the first, second, third, and fourth flat portions 62a, 62b, 62c, and 62d are formed with widths corresponding to the circumferential size of the valve body 30 that they support. A plurality of coil springs 70 are arranged in three rows on the first and second flat portions 62a and 62b. A plurality of coil springs 70 are arranged in two rows on the third and fourth flat portions 62c and 62d.

[0048] 2, a plurality of coil springs 70 are arranged between the first valve body 31 and the rotary shaft 60, between the second valve body 32 and the rotary shaft 60, between the third valve body 33 and the rotary shaft 60, and between the fourth valve body 34 and the rotary shaft 60. The coil springs 70 bias the first valve body 31, the second valve body 32, the third valve body 33, and the fourth valve body 34 toward the inner wall portion 12 in which the port 13 is formed. The coil springs 70 are arranged at a plurality of positions spaced apart in the axial direction.

[0049] The actuator 80 operates upon receiving a command signal from a controller (not shown). The actuator 80 is connected to the rotary shaft 60 and drives the rotary shaft 60 to rotate. This allows the actuator 80 to set the rotational positions of the first valve body 31, the second valve body 32, the third valve body 33, and the fourth valve body 34.

[0050] The flow path switching valve 1 is desirably arranged so that the position where the port 13 communicates is located at the top of the housing 10. This allows air mixed in the cooling water flowing inside to be guided to the outside of the flow path switching valve 1 via the port 13. The flow path switching valve 1 may also be arranged so that the cover member 20 is located at the top of the housing 10. In this case as well, air mixed in the cooling water flowing inside can be guided to the outside of the flow path switching valve 1 via the first port 13a and the second port 13b.

[0051] Next, the detailed configuration of the housing 10 will be described with reference to FIGS.

[0052] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 1. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 6.

[0053] 6 and 7, the inner wall portion 12 has a first inner wall portion 12a, a second inner wall portion 12b, and a pair of transition portions 12c. The inner wall portion 12 is made up of a first inner surface region A1 in which the first inner wall portion 12a is provided, a second inner surface region A2 in which the second inner wall portion 12b is provided, and a transition region A3 in which the transition portions 12c are provided.

[0054] The first inner wall portion 12a is a curved surface provided on a portion of the inner wall portion 12 in the circumferential direction. A plurality of ports 13 are provided on the first inner wall portion 12a. The first inner wall portion 12a is provided parallel to the central axis C. That is, the inclination angle of the first inner wall portion 12a with respect to the central axis C is 0°. The first inner wall portion 12a is provided in a first inner surface region A1 of the inner wall portion 12. The radius of the first inner surface region A1 from the central axis C is a first radius R1.

[0055] The first inner surface region A1, in which the first inner wall portion 12a is provided, has at least two ports 13 arranged in the circumferential direction, and has a circumferential length that is at least twice the circumferential range AP in which the two ports 13 are provided. Specifically, the central angle of the circumferential range AP in which the two ports 13 are provided is approximately 60°, while the central angle of the first inner surface region A1 is approximately 150°. Furthermore, the central angle of the first inner surface region A1 is set to be at least 4 / 3 times the central angle (110°) of the first valve body 31 and the second valve body 32.

[0056] Here, the circumferential size of the first valve body 31 and the second valve body 32 is formed to be large enough to allow three ports 13 to be arranged in the circumferential direction. When the first row D1 and the second row D2 of the first valve body 31 and the second valve body 32 are in communication with the port 13 (first communication state), the entire first row D1 to the third row D3 abut against the first inner wall portion 12a. Also, when the second row D2 and the third row D3 of the first valve body 31 and the second valve body 32 are in communication with the port 13 (second communication state), the entire first row D1 to the third row D3 abut against the first inner wall portion 12a.

[0057] As a result, whether the first valve body 31 and the second valve body 32 are switched to the first communication state or the second communication state, the entire sealing surfaces 31d, 32d of the first valve body 31 and the second valve body 32 abut against the first inner wall portion 12a. This prevents the first valve body 31 and the second valve body 32 from tilting and changing the abutment state.

[0058] The second inner wall portion 12b is provided in the second inner surface area A2 of the inner wall portion 12. The second inner wall portion 12b faces the first inner wall portion 12a across the central axis C. No port 13 is provided in the second inner wall portion 12b.

[0059] As shown in FIG. 6, the second inner wall portion 12b (second inner surface region A2) has a second radius R2 that is greater than the first radius R1 from the central axis C (R1 < R2). Specifically, the radius at the position where the second inner wall portion 12b is connected to the bottom surface portion 14 is the smallest, but this radius is the second radius R2. That is, the entire radius of the second inner wall portion 12b is greater than the first radius R1 of the first inner wall portion 12a.

[0060] As shown in FIG. 7, the range in which the second inner surface region A2 is provided is 180° or more in the axial direction view. That is, the range in which the second inner wall portion 12b is provided is 180° or more in the axial direction view. Thus, by setting the range of the second inner surface region A2 where the second inner wall portion 12b is provided to 180° or more in the axial direction view, the range where the first inner wall portion 12a with a small radius is provided becomes smaller, so that it is possible to easily remove the mold during molding with a resin material or the like.

[0061] As shown in FIG. 6, the radius R2 of the second inner wall portion 12b from the central axis C expands from the bottom surface portion 14 toward the lid member 20. Specifically, the second radius R2 at the connection portion of the second inner wall portion 12b with the bottom surface portion 14 is smaller than the maximum second radius R2max at the opening where the lid member 20 is attached to the second inner wall portion 12b (R2 < R2max).

[0062] The seal surfaces 31d, 32d, 33d, 34d of the valve body 30 located in the second inner surface region A2 contact the arc portion 23 and do not contact the inner wall portion 12 in at least a part of the axial direction. Specifically, in the second inner surface region A2, the seal surfaces 31d, 32d, 33d, 34d of the valve body 30 contact the inner wall portion 12 only near the connection portion of the second inner wall portion 12b with the bottom surface portion 14, and do not contact the inner wall portion 12 at an axial position closer to the lid member 20 than that.

[0063] Thereby, since the seal surfaces 31d, ********, 34d of the valve body 30 contact the arc portion 23 and do not contact the inner wall portion 12 in at least a part of the axial direction, the contact area between the seal surfaces 31d, ********, 34d and the inner wall portion 12 can be reduced, and the sliding resistance can be decreased.

[0064] The housing 10 is molded from a resin material or the like. Therefore, it is necessary to provide a draft angle on the inner wall portion 12 so that the mold can be removed in the axial direction. Therefore, the housing 10 is provided with an expanded diameter portion 17.

[0065] The expanded diameter portion 17 is provided on the second inner wall portion 12b. The expanded diameter portion 17 has a portion with a larger radius from the central axis C than the first inner wall portion 12a, and the radius from the central axis C changes in the axial direction. Specifically, the expanded diameter portion 17 is formed by the radius from the central axis C changing in the axial direction from a second radius R2 to a maximum second radius R2max.

[0066] Alternatively, for example, the radius between the connection portion of the second inner wall portion 12b with the bottom surface portion 14 and the opening where the cover member 20 is provided may be set as the maximum second radius R2max, and the radius of the approximate center portion in the axial direction between both end portions may be set as the second radius R2.

[0067] In this way, the second inner wall portion 12b is provided with the expanded diameter portion 17. Providing the expanded diameter portion 17 reduces the sliding resistance between the second inner wall portion 12b and the valve element 30. Furthermore, the sealing surfaces 31d, 32d, 33d, and 34d of the valve element 30 slide against the first inner wall portion 12a, making it possible to switch the communication states of the multiple ports 13 while ensuring sealing performance. Therefore, it is possible to ensure sealing performance and reduce sliding resistance at the same time.

[0068] The relative angle between the inner wall portion 12 and the central axis C is a predetermined angle α° including 0° for the first inner wall portion 12a, whereas it is an angle β° larger than the predetermined angle α for the second inner wall portion 12b (α<β).

[0069] As a result, when the housing 10 is molded from a resin material or the like, the draft angle for removing the mold can be used to make the inclination angle of the second inner wall portion 12b greater than that of the first inner wall portion 12a, thereby forming the expanded diameter portion 17. Furthermore, the provision of the expanded diameter portion 17 reduces the sliding resistance between the second inner wall portion 12b and the valve body 30.

[0070] In the housing 10, the inclination angle α of the first inner wall portion 12a is set to 0° (no draft gradient is provided), so the inclination angle β° of the second inner wall portion 12b is set to be larger than if a draft gradient were also provided on the first inner wall portion 12a.

[0071] The cover member 20 has an arcuate portion 23 that is formed in an arc shape along the inner wall portion 12, protrudes toward the inside of the body portion 11, and comes into sliding contact with parts of the seal surfaces 31d, 32d, 33d, and 34d.

[0072] By providing the arc portion 23 on the cover member 20, the arc portion 23 comes into sliding contact with a portion of the sealing surfaces 31d, 32d, 33d, and 34d, thereby reducing the contact area between the sealing surfaces 31d, 32d, 33d, and 34d and the arc portion 23, and reducing sliding resistance.

[0073] The arc portion 23 is located on the inner circumference of the second inner wall portion 12b in the second inner surface region A2. The arc portion 23 is formed in a range such that the central angle is 180° or more. Chamfered portions are formed on the inner circumference side of both circumferential ends of the arc portion 23. This prevents the valve body 30 from having a step when it moves from the transition region A3 to the second inner surface region A2, allowing the valve body 30 to slide smoothly.

[0074] The third radius R3 from the central axis C of the sliding contact surface 23a in sliding contact with the seal surfaces 31d, 32d, 33d, 34d at the arc portion 23 is greater than the first radius R1 from the central axis C of the first inner wall portion 12a.

[0075] As a result, the radius R3 of the sliding surface 23a of the arc portion 23 is larger than the radius R1 of the first inner wall portion 12a, and therefore the coil spring 70 is in an expanded state when the valve body 30 slides against the arc portion 23. This reduces the contact area between the seal surfaces 31d, 32d, 33d, and 34d and the arc portion 23, and also reduces the pressing force of the seal surfaces 31d, 32d, 33d, and 34d, thereby further reducing the sliding resistance.

[0076] The third radius R3 of the sliding surface 23a is the same as the second radius R2 at the connection portion of the second inner wall portion 12b with the bottom surface portion 14 (R3 = R2). Therefore, when the valve body 30 is located in the second inside surface area A2, the seal surfaces 31d, 32d, 33d, and 34d slide on the vicinity of the connection portion of the second inner wall portion 12b with the bottom surface portion 14 and on the sliding surface 23a of the arc portion 23. Therefore, both axial ends of the valve body 30 slide on portions of the same radius, preventing the valve body 30 from tilting and changing its posture.

[0077] The transition portion 12c is provided in the transition region A3 of the inner wall portion 12. The transition portion 12c is a surface that connects the first inner wall portion 12a and the second inner wall portion 12b. A pair of transition portions 12c are provided so as to connect both end portions of the first inner wall portion 12a and the second inner wall portion 12b. The transition portion 12c is formed in a substantially flat shape, but may also be formed in a curved shape.

[0078] The transition region A3 is provided between the first inner surface region A1 and the second inner surface region A2. A pair of transition regions A3 are provided between both end portions of the first inner surface region A1 and the second inner surface region A2. The distance of the transition region A3 from the central axis C is greater than the first radius R1 and less than the second radius R2. The distance of the transition region A3 from the central axis C is the same as the first radius R1 at the position where it is connected to the first inner surface region A1, and gradually increases to the same as the second radius R2 at the position where it is connected to the second inner surface region A2.

[0079] Next, a modified example of the housing 10 will be described with reference to FIG.

[0080] FIG. 9 is a perspective view illustrating a modified example of the housing 10. In FIG.

[0081] In this modification, the first inner wall portion 12a (first inner surface region A1) and the transition portion 12c (transition region A3) have a sliding member 12d as a low friction resistance portion.

[0082] The sliding member 12d has a smaller coefficient of friction than the second inner wall portion 12b of the second inner surface region A2. The sliding member 12d is formed, for example, from a resin material having a smaller coefficient of friction than the material forming the main body portion 11. The sliding member 12d is attached to the main body portion 11 as a separate member from the main body portion 11. Alternatively, the sliding member 12d may be provided integrally with the main body portion 11.

[0083] In this way, by providing the sliding member 12d having a smaller coefficient of friction than the second inner wall portion 12b, the sliding resistance between the valve body 30 and the sealing surfaces 31d, 32d, 33d, and 34d can be reduced compared to when the sliding member 12d is not provided.

[0084] In addition, when the sliding member 12d is provided, the radius of the inner circumferential surface of the sliding member 12d from the central axis C is a first radius R1. Therefore, the radial position of the valve body 30 does not change in the first inner surface region A1.

[0085] Next, a modification of this embodiment will be described with reference to FIGS.

[0086] 10 is a cross-sectional view of a flow path switching valve 1 according to a modified example of the embodiment of the present invention. FIG. 11 is an enlarged view of a main part in FIG.

[0087] In the modification shown in FIGS. 10 and 11, the housing 10 has a plurality of slits 16 as the enlarged diameter portion 17.

[0088] As shown in Figure 10, the slit 16 extends in the axial direction on the inner wall portion 12 of the housing 10. The slit 16 is provided in the second inner wall portion 12b. The slit 16 corresponds to an expanded diameter portion 17 that has a portion with a larger radius from the central axis C than the first inner wall portion 12a and whose radius from the central axis C changes in the radial direction. In this case, the expanded diameter portion 17 is formed by changing the radius from the central axis C in the radial direction.

[0089] The slits 16 reduce the contact area between the inner wall 12 where the port 13 is formed and a seal portion (described later) of the valve element 30 at another position on the inner wall 12 opposite to the central axis C, thereby reducing sliding resistance. This reduces the drive torque of the actuator 80, allowing a smaller actuator 80 to be used. This allows the entire flow path switching valve 1 to be made smaller.

[0090] 11, the slits 16 are formed so that adjacent slits 16 in the circumferential direction are connected by a continuous smooth curved surface. Abutment surfaces 16a are formed between adjacent slits 16.

[0091] The contact surface 16a is a curved surface formed with the same curvature as the inner wall portion 12, and constitutes a part of the inner wall portion 12. By providing the contact surface 16a, the seal portion of the valve body 30 and the contact surface 16a come into surface contact rather than line contact, so that the force acting on the valve body 30 when the seal portion of the valve body 30 is pressed against the inner wall portion 12 can be dispersed.

[0092] According to the above embodiment, the following effects are achieved.

[0093] The flow path switching valve 1 comprises a housing 10 having a cylindrical inner wall portion 12 in which a plurality of ports 13 open, unevenly distributed in a circumferential direction, and a plurality of valve bodies 30 that are rotatably accommodated inside the housing 10 around a central axis C, have sealing surfaces 31d, 32d, 33d, and 34d that slide against the inner wall portion 12, and switch the communication state of the plurality of ports 13, the inner wall portion 12 having a first inner wall portion 12a in which the plurality of ports 13 are provided, and a second inner wall portion 12b that faces the first inner wall portion 12a across the central axis C and in which no ports 13 are provided, and the second inner wall portion 12b has an expanded diameter portion 17 that has a portion with a larger radius from the central axis C than the first inner wall portion 12a, and whose radius from the central axis C changes in the axial or radial direction.

[0094] In addition, the flow path switching valve 1 further includes a rotating shaft 60 extending in the axial direction and switching the rotational position of the valve body 30 by its rotation, and a plurality of coil springs 70 provided between the rotating shaft 60 and the valve body 30 and biasing the valve body 30 toward the inner wall portion 12, and the sealing surfaces 31d, 32d, 33d, and 34d are pressed against the inner wall portion 12 by the biasing force of the coil springs 70 to seal between them.

[0095] According to these configurations, the inner wall portion 12 of the housing 10 has a first inner wall portion 12a in which the multiple ports 13 are provided, and a second inner wall portion 12b that faces the first inner wall portion 12a across the central axis C and in which no ports 13 are provided. The second inner wall portion 12b has an expanded diameter portion 17 that has a portion with a larger radius from the central axis C than the first inner wall portion 12a and whose radius from the central axis C changes in the axial or radial direction. Therefore, the sealing surfaces 31d, 32d, 33d, and 34d of the valve element 30 slide against the first inner wall portion 12a, thereby ensuring sealing and switching the communication state of the multiple ports 13. The provision of the expanded diameter portion 17 reduces sliding resistance between the second inner wall portion 12b and the valve element 30. Therefore, it is possible to ensure sealing and reduce sliding resistance at the same time.

[0096] The expanded diameter portion 17 is formed by changing the radius from the central axis C in the axial direction, and the relative angle between the inner wall portion 12 and the central axis C is a predetermined angle α including 0° in the first inner wall portion 12a, while it is an angle β larger than the predetermined angle α in the second inner wall portion 12b.

[0097] The housing 10 has a main body 11 having an inner wall 12 and multiple ports 13 opening therein, a bottom surface 14 covering one axial end of the main body 11, and a lid member 20 covering the other axial end of the main body 11, and the radius R2 from the central axis C of the second inner wall 12b expands from the bottom surface 14 toward the lid member 20.

[0098] According to these configurations, when the housing 10 is molded from a resin material or the like, the draft angle for removing the mold can be used to make the inclination angle of the second inner wall portion 12b greater than that of the first inner wall portion 12a, thereby forming the expanded diameter portion 17. The provision of the expanded diameter portion 17 reduces the sliding resistance between the second inner wall portion 12b and the valve element 30.

[0099] The cover member 20 has an arcuate portion 23 that is formed in an arc shape along the inner wall portion 12, protrudes toward the inside of the body portion 11, and comes into sliding contact with parts of the seal surfaces 31d, 32d, 33d, and 34d.

[0100] According to this configuration, the arc portion 23 provided on the cover member 20 comes into sliding contact with a portion of the sealing surfaces 31d, 32d, 33d, and 34d, thereby reducing the contact area between the sealing surfaces 31d, 32d, 33d, and 34d and the arc portion 23, and reducing sliding resistance.

[0101] The radius R3 from the central axis C of the sliding contact surface 23a in sliding contact with the seal surfaces 31d, 32d, 33d, 34d at the arcuate portion 23 is greater than the radius R1 from the central axis C of the first inner wall portion 12a.

[0102] According to this configuration, the radius R3 of the sliding contact surface 23a of the arc portion 23 is larger than the radius R1 of the first inner wall portion 12a, and therefore the coil spring 70 is in an expanded state when the valve body 30 is in sliding contact with the arc portion 23. Therefore, the contact area between the seal surfaces 31d, 32d, 33d, and 34d and the arc portion 23 is reduced, and the pressing force of the seal surfaces 31d, 32d, 33d, and 34d is also reduced, thereby further reducing the sliding resistance.

[0103] The sealing surfaces 31d, 32d, 33d, and 34d of the valve body 30 located in the second inner surface area A2 contact the arc portion 23 and do not contact the inner wall portion 12 at least partially in the axial direction.

[0104] According to this configuration, the sealing surfaces 31d, 32d, 33d, and 34d of the valve body 30 contact the arc portion 23 and do not contact the inner wall portion 12 in at least part of the axial direction, thereby reducing the contact area between the sealing surfaces 31d, 32d, 33d, and 34d and the inner wall portion 12 and reducing sliding resistance.

[0105] The range in which the second inner wall portion 12b is provided is 180° or more when viewed in the axial direction. That is, the range in which the second inner surface region A2 is provided is 180° or more when viewed in the axial direction.

[0106] According to this configuration, by making the range of the second inner surface area A2 in which the second inner wall portion 12b is provided 180° or more when viewed in the axial direction, it is possible to make it easier to remove the mold when molding using a resin material, etc.

[0107] In the first inner surface region A1, at least two ports 13 are arranged in the circumferential direction, and the first inner surface region A1 has a circumferential length that is at least twice the circumferential range AP in which the two ports 13 are provided.

[0108] According to this configuration, the circumferential size of the first valve body 31 and the second valve body 32 is formed to be large enough to arrange three ports 13 in the circumferential direction. Therefore, when the first row D1 and the second row D2 of the first valve body 31 and the second valve body 32 are in communication with the port 13, the entire first row D1 to the third row D3 abut against the first inner wall portion 12a. Furthermore, when the second row D2 and the third row D3 of the first valve body 31 and the second valve body 32 are in communication with the port 13, the entire first row D1 to the third row D3 abut against the first inner wall portion 12a.

[0109] This causes the entire sealing surfaces 31d, 32d of the first valve body 31 and the second valve body 32 to abut against the first inner wall portion 12a, thereby preventing the first valve body 31 and the second valve body 32 from tilting and changing the abutment state.

[0110] The first inner surface region A1 and the transition region A3 have a sliding member 12d having a smaller friction coefficient than the second inner wall portion 12b of the second inner surface region A2.

[0111] According to this configuration, by providing a sliding member 12d having a smaller coefficient of friction than the second inner wall portion 12b, the sliding resistance between the valve body 30 and the sealing surfaces 31d, 32d, 33d, and 34d can be reduced compared to when the sliding member 12d is not provided.

[0112] The expanded diameter portion 17 is formed by changing the radius from the central axis C in the radial direction. The expanded diameter portion 17 has a plurality of slits 16 provided in the second inner wall portion 12b of the housing 10 and extending in the axial direction.

[0113] According to these configurations, the slits 16 reduce the contact area between the inner wall portion 12 where the port 13 is formed and the seal portion (described later) of the valve element 30 at another position on the inner wall portion 12 opposite to the central axis C, thereby reducing sliding resistance. This reduces the drive torque of the actuator 80, allowing a smaller actuator 80 to be used. This makes it possible to reduce the size of the entire flow path switching valve 1.

[0114] The first inner surface region A1 and the transition region A3 have a sliding member 12d having a smaller friction coefficient than the second inner wall portion 12b of the second inner surface region A2.

[0115] According to this configuration, by providing a sliding member 12d having a smaller coefficient of friction than the second inner wall portion 12b, the sliding resistance between the valve body 30 and the sealing surfaces 31d, 32d, 33d, and 34d can be reduced compared to when the sliding member 12d is not provided.

[0116] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments. [Explanation of symbols]

[0117] 1 Flow path switching valve 10. Housing 11 Main body 12 Inner wall 12a 1st inner wall part 12b Second inner wall part 12d Sliding member (low friction resistance part) 13 ports 14 Bottom part (bottom part) 16 Slit (expanded diameter section, sliding resistance reduction section) 17 Expanded diameter part 20 Lid member (lid portion) 23 Arc section 23a Sliding surface 30 Valve body 31 First valve body 31d sealing surface 32 Second valve body 32d sealing surface 33 Third valve body 33d sealing surface 34 Fourth valve body 34d sealing surface 60 Rotational Axis 70 Coil spring (biasing member) A1 First inner surface area A2 2nd inner surface area A3 transition area C center axis

Claims

1. A flow path switching valve, a housing having a cylindrical inner wall portion and a plurality of ports opening in a circumferentially unevenly distributed manner; a plurality of valve bodies that are accommodated inside the housing so as to be rotatable about a central axis, have sealing surfaces that come into sliding contact with the inner wall portion, and switch the communication states of the plurality of ports; Equipped with the inner wall portion includes a first inner wall portion in which the plurality of ports are provided, and a second inner wall portion that faces the first inner wall portion across the central axis and in which the ports are not provided, the second inner wall portion has a portion having a larger radius from the central axis than the first inner wall portion, and has an expanded diameter portion whose radius from the central axis changes in the axial direction or the radial direction. Flow path switching valve.

2. The flow path switching valve according to claim 1, a rotary shaft extending in the axial direction and rotating to switch the rotational position of the valve body; a biasing member provided between the rotary shaft and the valve body and biasing the valve body toward the inner wall portion; Further provided with the sealing surface is pressed against the inner wall portion by the biasing force of the biasing member to form a seal between the sealing surface and the inner wall portion. Flow path switching valve.

3. The flow path switching valve according to claim 2, the expanded diameter portion is formed by a change in radius from the central axis in the axial direction, a relative angle between the inner wall portion and the central axis is a predetermined angle including 0° in the first inner wall portion, and is larger than the predetermined angle in the second inner wall portion; Flow path switching valve.

4. The flow path switching valve according to claim 3, The housing includes: a main body having the inner wall and into which the plurality of ports open; a bottom portion covering one end of the main body portion in the axial direction; a cover portion that covers the other end of the main body portion in the axial direction; and The radius of the second inner wall portion from the central axis increases from the bottom portion toward the lid portion. Flow path switching valve.

5. The flow path switching valve according to claim 4, the cover portion has an arc portion formed in an arc shape along the inner wall portion, protruding toward the inside of the main body portion, and in sliding contact with a part of the sealing surface. Flow path switching valve.

6. The flow path switching valve according to claim 5, a radius of the sliding contact surface that is in sliding contact with the seal surface at the arc portion from the central axis is larger than a radius of the first inner wall portion from the central axis; Flow path switching valve.

7. The flow path switching valve according to claim 6, The inner wall portion is a first inner surface region provided with the first inner wall portion and having a first radius from the central axis; a second inner surface region in which the second inner wall portion is provided and whose radius from the central axis is a second radius greater than the first radius; a transition region provided between the first inner surface region and the second inner surface region, the transition region having a distance from the central axis greater than the first radius and smaller than the second radius; Consists of: Flow path switching valve.

8. The flow path switching valve according to claim 7, the sealing surface of the valve body located in the second inner surface region contacts the arc portion and does not contact the inner wall portion in at least a part of the axial direction; Flow path switching valve.

9. 5. The flow path switching valve according to claim 1, The range in which the second inner wall portion is provided is 180° or more when viewed in the axial direction. Flow path switching valve.

10. The flow path switching valve according to claim 9, The inner wall portion is a first inner surface region provided with the first inner wall portion and having a first radius from the central axis; a second inner surface region in which the second inner wall portion is provided and whose radius from the central axis is a second radius greater than the first radius; a transition region provided between the first inner surface region and the second inner surface region, the transition region having a distance from the central axis greater than the first radius and smaller than the second radius; It consists of The range in which the second inner surface region is provided is 180° or more when viewed in the axial direction. Flow path switching valve.

11. The flow path switching valve according to claim 10, At least two of the ports are arranged in the circumferential direction of the first inner surface region, and the first inner surface region has a circumferential length that is at least twice the circumferential range in which the two ports are provided. Flow path switching valve.

12. The flow path switching valve according to claim 11, the first inner surface region and the transition region have a low friction resistance portion having a friction coefficient smaller than that of the second inner wall portion of the second inner surface region; Flow path switching valve.

13. The flow path switching valve according to claim 1 or 2, The expanded diameter portion is formed by changing a radius from the central axis in the radial direction. Flow path switching valve.

14. The flow path switching valve according to claim 13, The expanded diameter portion has a plurality of slits extending in the axial direction in the second inner wall portion of the housing. Flow path switching valve.

15. The flow path switching valve according to claim 14, The inner wall portion is a first inner surface region provided with the first inner wall portion and having a first radius from the central axis; a second inner surface region in which the second inner wall portion is provided and whose radius from the central axis is a second radius greater than the first radius; a transition region provided between the first inner surface region and the second inner surface region, the transition region having a distance from the central axis greater than the first radius and smaller than the second radius; It consists of the first inner surface region and the transition region have a low friction resistance portion having a friction coefficient smaller than that of the second inner wall portion of the second inner surface region; Flow path switching valve.

Images