Electric three-way shutter

Abstract

To provide an electric three-way shutter which can suppress the generation of dew condensation in a drive part even if cryogenic atmospheric air is taken into a main body.SOLUTION: In an electric three-way shutter having a first port 7, a second port 8 and a third port 9 which are orthogonal to the axis of the first port 7, and arranged so as to coaxially oppose each other, a body part 2 in which flow passages 14, 15 and 16 of the ports, and a valve chamber 17 in which openings 20, 21 and 22 individually communicating with the flow passages are formed, a switching blade 10 supported by the body part 2 so as to be turnable around its own axis, and turning in the valve chamber 17, and a drive part 3 for turning and driving the switching blade 10 by electricity-carrying, the body part 2 is constituted by a body 4 which is formed of foaming polystyrene, a metal-made ceiling plate 5 and a metal-made bottom plate 6 for gripping the body 4 in a vertical direction, and a columnar support 11 for connecting the ceiling plate 5 and the bottom plate 6, and the drive part 3 is attached to the ceiling plate 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this application relates to an electric three-way shutter used in a total heat exchange ventilation system. [Background technology]

[0002] Conventionally, in a 24-hour total heat exchange ventilation system, the outside air taken in for ventilation is sent directly to each room as warm or cold air by a heat exchanger installed under the floor. In this system, an electric three-way shutter that switches the air flow path is disclosed in Non-Patent Document 1 and elsewhere.

[0003] Non-Patent Document 1 discloses the specifications of the P-183DUE electric three-way shutter (middle-mounted type) manufactured by Mitsubishi Electric Corp. The main body (having a valve chamber) of an electric three-way shutter used in a 24-hour total heat exchange ventilation system, such as the electric three-way shutter disclosed in Non-Patent Document 1, is formed by assembling metal sheet parts such as galvanized steel sheets. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Mitsubishi Electric Corporation, "Electric Three-Way Shutter (Middle Mount Type) P-183DUE Delivery Specifications", [online], February 16, 2014, [Retrieved September 1, 2022], Internet <URL: https: / / dl.mitsubishielectric.co.jp / dl / ldg / wink_doc / m_contents / wink / FAN_SN / p―183due_0_sn.pdf> DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] In a 24-hour total heat exchange ventilation system, the electric three-way shutter that switches the air flow path is often placed under the floor. In such a case, when an electric three-way shutter whose main body is made of metal sheet metal such as galvanized steel sheet, such as the electric three-way shutter disclosed in Non-Patent Document 1, is used in a cold region, if extremely cold outside air is taken into the electric three-way shutter, the temperature difference between the outside air and the warm and humid air inside the room or under the floor causes condensation on the metal surface of the main body of the electric three-way shutter, which may cause problems in the driving parts such as the motor assembled on the metal surface. In addition, it is difficult to mold the main body formed by assembling metal sheet metal parts using a mold molding, making it difficult to reduce the manufacturing cost.

[0006] The technology disclosed in this application has been proposed in consideration of the above-mentioned problems, and aims to provide an electric three-way shutter that prevents condensation by comprising a main body made of polystyrene foam, top and bottom plates made of hard materials that hold the body in place in the vertical direction, and a connecting member that connects the top and bottom plates. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the electric three-way shutter according to claim 1 is an electric three-way shutter used in a total heat exchange ventilation system, the electric three-way shutter comprising: a first port communicating with an indoor space; a second port communicating with outside air and a third port communicating with a ventilation device, the second port being perpendicular to the axis of the first port and arranged opposite to the first port on the same axis; a body in which a valve chamber is formed with each opening that is individually connected to the flow path of each port; a valve body that is supported by the body so as to be rotatable about its own axis and rotates within the valve chamber; and a drive unit that drives the valve body to rotate when electricity is applied, the body comprising a main body molded from polystyrene foam and having a valve chamber, top and bottom plates made of hard members that hold the main body in the vertical direction, and a connecting member that connects the top plate and the bottom plate, the drive unit being attached to at least one of the top plate and the bottom plate.

[0008] The electric three-way shutter of claim 2 is the electric three-way shutter as described in claim 1, characterized in that a block made of nonwoven fabric is provided on the outer edge of each opening of each port of the valve chamber, surrounding each opening and formed to a height such that its upper surface abuts against the outer peripheral edge of the valve body.

[0009] The electric three-way shutter according to claim 3 is the electric three-way shutter according to claim 2, wherein the blocks comprise a first block provided between an opening communicating with the flow path of the first port and an opening communicating with the flow path of the second port, a second block provided between the opening communicating with the flow path of the first port and an opening communicating with the flow path of the third port, a third block provided at a position facing the first block on the outer periphery of the opening communicating with the flow path of the second port, and a fourth block provided at a position facing the second block on the outer periphery of the opening communicating with the flow path of the third port, and wherein the first and second blocks are provided such that their surfaces that abut against the outer periphery of the opening communicating with the flow path of the third port are inclined inward (toward the inside of the valve chamber) with respect to a tangent of a circular arc along which the outer periphery of the rotating valve body moves, with the first block facing the second port and the second block facing the third port.

[0010] The electric three-way shutter according to claim 4 is 2 or 3 a stepping motor is used in the drive unit to adjust the rotation angle of the valve body, and the drive unit controls a first ventilation state in which the valve body is rotated in the direction of the flow path of the first port to bring an outer circumferential end of the valve body into contact with an upper surface of a block of an opening communicating with the flow path of the first port, thereby substantially blocking the opening of the first port communicating with the indoor space, thereby communicating between the outside air and the ventilation device; a third ventilation state in which the valve body is rotated in the direction of the flow path of the third port to bring an outer circumferential end of the valve body into contact with an upper surface of a block of an opening communicating with the flow path of the third port, thereby substantially blocking the opening of the third port communicating with the ventilation device, thereby communicating between the outside air and the indoor space; ofThis is characterized by the fact that it can be switched between an indoor air recirculation state in which the opening of the first port and the opening of the second port are each partially open to send a mixture of outside air and air in the indoor space to the ventilation device. Effect of the Invention

[0011] In the electric three-way shutter of claim 1, the main body having a valve chamber is molded from polystyrene foam, and the drive unit including a motor, etc. is attached to at least one of the top and bottom plates of the main body via the polystyrene foam. Therefore, even if extremely cold outside air is taken into the main body, the insulating effect of the polystyrene foam prevents the air from being transmitted to the top and bottom plates, thereby preventing condensation from forming in the drive unit and preventing malfunction of the drive unit.

[0012] In addition, by using polystyrene foam as the main body material, it is possible to easily perform molding processing using a metal mold, and since the material is inexpensive polystyrene foam, manufacturing costs can be reduced. Furthermore, by sandwiching the main body made of polystyrene foam between top and bottom plates made of hard materials such as metal sheet metal in the vertical direction and connecting the top and bottom plates with a connecting member, a driving unit such as a motor can be attached to the top or bottom plate without the main body being deformed.

[0013] In the electric three-way shutter according to claim 2, even if a gap occurs between the valve disc and each opening due to tolerances that occur when the main body is molded from polystyrene foam, by providing blocks made of nonwoven fabric on the outer edge of each opening of each port of the valve chamber, so that the upper surface of the blocks abuts against the outer peripheral edge of the valve disc and surrounds each opening, the blocks provided at each opening abut against the valve disc when the opening is blocked by the valve disc, so that the blocking of each flow path by the valve disc can be more reliably performed. Also, by forming the blocks from nonwoven fabric, the blocks are less likely to be damaged even if the valve disc abuts excessively, and therefore the generation of dust when damaged can be suppressed.

[0014] In the electric three-way shutter according to claim 3, the surfaces of the first block provided between the opening communicating with the flow passage of the first port and the opening communicating with the flow passage of the second port, and the second block provided between the opening communicating with the flow passage of the first port and the opening communicating with the flow passage of the third port, which come into contact with the outer circumferential end of the valve disc, are inclined inward (toward the valve chamber interior) with respect to the tangent of the arc along which the outer circumferential end of the rotating valve disc moves, with the first block facing the second port and the second block facing the third port, respectively, so that the valve disc can be rotated while the outer circumferential end of the valve disc interferes with the contact surface of the first block or the second block in the compression direction. This reduces the load on the blocks and makes it possible to more reliably bring the outer circumferential end of the valve disc into contact with the blocks.

[0015] In the electric three-way shutter according to claim 4, in areas where the outside temperature is extremely low, there was a problem that the heat exchanger would freeze when taking in outside air. However, by adopting a stepping motor to rotate the valve body, the rotation angle of the valve body can be adjusted as desired, and the valve body can be moved between the first port and the second port. of By adjusting and rotating the port to the middle position, it becomes possible to mix the outside air with the indoor air while taking in a small amount of outside air, and the air can be sent to the ventilation system at a temperature that will not freeze the heat exchanger. [Brief description of the drawings]

[0016] [Figure 1] 1A to 1D are external views of an electric three-way shutter according to one embodiment of the present invention, in which (A) is a top view, (B) a front view, (C) a bottom view, and (D) a side view of the front view seen from the right. [Diagram 2] 1. (A) is a cross-sectional view taken along the line AA in FIG. 1, (B) is a cross-sectional view taken along the line BB in FIG. 1, and (C) is a cross-sectional view taken along the line CC in FIG. [Diagram 3] 2C, and (B) is an enlarged view of region E in FIG. 3C. [Figure 4]FIG. 4 is a cross-sectional view taken along line AA in FIG. 3; and FIG. 5 is a cross-sectional view taken along line BB in FIG. 3. [Diagram 5] 5A is a top view of the lower part of the body forming the body (main body) of the present invention, (B) a front view, (C) a bottom view, (D) a side view of the front view seen from the right, (E) a cross-sectional view taken along the line AA in FIG. 4, and (F) a cross-sectional view taken along the line BB in FIG. 4. [Figure 6] 6A is a front view of a second port and a third port according to the present invention, FIG. 6B is a side view, and FIG. 6C is a cross-sectional view taken along line AA in FIG. 5. [Figure 7] 7A is a top view of a switching blade (functioning as a valve body) according to the present invention, (B) a front view, (C) a bottom view, (D) a side view of the front view from the right, and (E) a cross-sectional view along the line AA in FIG. 6. [Figure 8] FIG. 1A is a front view and a cross-sectional view AA of a top plate that holds the body in the vertical direction, and FIG. 1B is a front view and a cross-sectional view BB of a bottom plate. [Figure 9] 1 is an explanatory diagram of a method for assembling an electric three-way shutter. [Figure 10] FIG. 9 is a perspective view for explaining the assembled state in FIG. 8. [Figure 11] 11 is an explanatory diagram of a method for switching flow paths by rotating a switching blade. FIG. [Figure 12] 13A and 13B are views showing another embodiment of a connecting member that connects the top plate and the bottom plate that vertically sandwich the body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] First, an electric three-path shutter 1 according to one embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an external view of an electric three-path shutter 1 according to one embodiment of the present invention. Fig. 1 (A) is a top view, (B) is a front view, (C) is a bottom view, and (D) is a side view of the front view seen from the right.

[0018] As shown in Fig. 1, the electric three-way shutter 1 is composed of a switching blade 10 for switching the flow path, a body section 2 provided with a valve chamber 17 in which the switching blade 10 is housed and a first port 7, a second port 8 and a third port 9 connected to the left and right ends of the body section 2 perpendicular to the axis of the first port 7 and facing each other on the same axis, and a drive section 3 composed of a stepping motor and gears for controlling the rotation of the switching blade 10. The body section 2 is composed of a body 4 made of polystyrene foam, a top plate 5 and a bottom plate 6 for holding the body 4 in the vertical direction, and a support 11 for connecting the top plate 5 and the bottom plate 6 in a state in which the body 4 is held between the top plate 5 and the bottom plate 6. As shown in Figs. 1A, 1B, and 1D, the drive section 3 is attached to the top plate 5 placed on the top surface of the body 4 by mounting screws (not shown). In this embodiment, the first port 7 is incorporated into a total heat exchange ventilation system so as to communicate with the indoor space, the second port 8 with the outside air, and the third port 9 with a ventilation device.

[0019] The entire body 4 is made of polystyrene foam. Since it is manufactured by molding using a mold, it is divided into an upper body part 4A and a lower body part 4B along the center line of the axis of the second port 8 and the third port 9 (line CC in FIG. 1B). Furthermore, the top plate 5 and the bottom plate 6 are formed by processing metal sheet metal as hard plate members, but are not limited to this.

[0020] Fig. 2 is a cross-sectional view of the electric three-way shutter 1. Fig. 2(A) is a cross-sectional view taken along line AA in Fig. 1, Fig. 2(B) is a cross-sectional view taken along line BB in Fig. 1, and Fig. 2(C) is a cross-sectional view taken along line CC in Fig. 1.

[0021] 2(C), a valve chamber 17 in which the switching blade 10 is rotatably housed is provided in the center of the body 4. The valve chamber 17 is provided with a first opening 20 communicating with the flow path 14 of the first port 7, a second opening 21 connected to the second port 8 and communicating with the flow path 15 of the second port 8, and a third opening 22 connected to the third port 9 and communicating with the flow path 16 of the third port 9. Blocks 13A, 13B, 13C, and 13D made of nonwoven fabric are attached to the outer periphery of the first opening 20, the second opening 21, and the third opening 22. The blocks 13A, 13B, 13C, and 13D have a rectangular prism shape extending in the front-to-rear direction with respect to (C) of Figure 2, with their lengths being slightly larger than the diameters of their respective openings, and their diameters (height toward the switching blade 10) being set to a size sufficient to allow the outer peripheral end of the valve portion 10b of the switching blade 10 rotating within the valve chamber 17 to abut against it.

[0022] When the body 4 is formed by molding polystyrene foam as in the electric three-way shutter 1 according to the present embodiment, gaps are likely to occur between the openings 20, 21, 22 and the outer circumferential end of the valve portion 10b of the switching blade 10 due to tolerances. Therefore, in the electric three-way shutter 1 according to the present embodiment, the blocks 13A, 13B, 13C, 13D are attached to the outer circumferential end of each opening 20, 21, 22 as described above to fill the gaps that have occurred. As a result, when the openings 20, 21, 22 are blocked by the valve portion 10b of the switching blade 10, the blocks 13A, 13B, 13C, 13D come into contact with the outer circumferential end of the valve portion 10b of the switching blade 10 at each opening, so that the switching blade 10 can more reliably block each flow path that communicates with each opening. In addition, by forming blocks 13A, 13B, 13C, and 13D from nonwoven fabric, blocks 13A, 13B, 13C, and 13D are less likely to be damaged even if the diverter blade 10 comes into excessive contact with them, and therefore, the generation of waste when damaged can also be suppressed.

[0023] As shown in FIG. 2, the valve shaft 10a of the switching blade 10 is rotatably assembled in the center of the valve chamber 17, with its upper end portion penetrating a through hole in the upper surface of the upper body 4A of the body 4 and inserted into the drive unit 3, and its lower end portion penetrating a through hole in the lower surface of the lower body 4B of the body 4 and supported by a bearing (described later) of the bottom plate 6. The rotation angle is controlled by a stepping motor 18, gears and a drive board (not shown) incorporated inside the drive unit 3, and the like, whereby the rotation of the switching blade 10 is controlled within the valve chamber 17.

[0024] FIG. 3 is a diagram for explaining the mounting state of blocks A and B, which is one of the features of the present invention. FIG. 3(A) illustrates FIG. 2(C), and FIG. 3(B) illustrates FIG. 3(A). Area E In this embodiment, the diverter blade 10 is adapted to rotate approximately 90° (i.e., rotate 180°) in the left and right directions in the drawing with respect to the axial center line of the first port 7. Therefore, a block provided between an opening 20 communicating with the flow passage 14 of the first port and an opening 21 communicating with the flow passage 15 of the second port, through which the diverter blade 10 passes, is provided. 13A and a block provided between an opening 20 communicating with the flow passage 14 of the first port and an opening 22 communicating with the flow passage 16 of the third port. 13B 3B, the switching blade 10 is attached so that lines S1 and S2 along the surface that abuts against the outer circumferential end of the valve portion 10b of the switching blade 10 are inclined at an angle R toward the openings 21 and 22, respectively, toward the inside of the valve chamber 17, with respect to tangents P1 and P2 of the arc along which the outer circumferential end of the valve portion 10b of the rotating switching blade 10 moves. Therefore, the switching blade 10 can be rotated while the outer circumferential end of the valve portion 10b of the switching blade 10 interferes with the abutment surface of the block 13A or block 13B in the compression direction. As a result, the block 13A and 13B The load on the valve portion 10b of the switching blade 10 can be reduced, and the outer peripheral end of the valve portion 10b of the switching blade 10 and the block can be more reliably connected. 13A or 13BIn addition, by machining the mounting surfaces 4P and 4Q of the body 4 to which the blocks 13A and 13B are attached in accordance with the inclination at which the blocks 13A and 13B are attached, block Since the same shapes can be used for 13A, 13B, 13C, and 13D, the cost of parts can be reduced.

[0025] Next, the main components of the electric three-way shutter 1 will be described individually with reference to the drawings.

[0026] Figure 4 shows an external view and a cross-sectional view of the upper body part 4A that forms the body 4. In Figure 4, (A) is a top view, (B) is a front view, (C) is a bottom view, (D) is a side view of the front view seen from the right, (E) is an AA cross-sectional view of (A), and (F) is a BB cross-sectional view of (C).

[0027] 4(A), a body upper surface portion 4a on which the top plate 5 is placed is formed on the top surface of the upper body portion 4A. The body upper surface portion 4a is formed along the outer circumferential shape of the top plate 5, which allows the top plate 5 to be positioned and placed on the top surface of the body 4. The body upper surface portion 4a also has an upper through-hole 4c in the center through which the valve shaft 10a of the switching blade 10 passes, and relief holes 4m (5 locations) for the lower ends of the mounting screws that protrude toward the body 4 when the drive unit 3 is attached to the top plate 5.

[0028] The upper body 4b is provided below the upper body surface 4a in the drawing, and includes a valve chamber upper portion 4j forming the upper portion of the valve chamber 17, a first passage upper portion 4e forming the passage 14 of the first port 7, a second passage upper portion 4g including a mounting groove for connecting the second port 8, a second passage upper portion 4h including a mounting groove for connecting the third port 9, an upper portion of an opening 20 connecting the valve chamber 17 and the passage 14 of the first port 7, an upper portion of an opening 21 connecting the valve chamber 17 and the passage 15 of the second port 8, and an upper portion of an opening 22 connecting the valve chamber 17 and the passage 16 of the third port 9. The lower end surface of the upper body 4A is provided with upper body fitting holes 4k (four locations) that fit with positioning pins provided at the upper end of the lower body 4B described below. Furthermore, through grooves 4d (three locations) for three supports 11 connecting the top plate 5 and the bottom plate 6 are formed in the vertical direction along the side surface of the upper body 4A.

[0029] Figure 5 shows an external view and a cross-sectional view of the lower body part 4B which forms the body 4. In Figure 5, (A) is a top view, (B) is a front view, (C) is a bottom view, (D) is a side view of the front view seen from the right, (E) is an AA cross-sectional view of (A), and (F) is a BB cross-sectional view of (C).

[0030] As shown in (A), (B) and (E) of Fig. 5, the upper surface of the upper body 4A is provided with four positioning pins 4r which engage with the upper body engagement holes 4k on the lower end surface of the upper body 4A. The lower body upper main body 4n is provided with a lower valve chamber 4w which forms the lower part of the valve chamber 17, a lower first passage 4v which forms the passage 14 of the first port 7, a lower second passage 4t which includes an attachment groove for connecting the second port 8, a lower second passage 4u which includes an attachment groove for connecting the third port 9, a lower part of an opening 20 which connects the valve chamber 17 to the passage 14 of the first port 7, a lower part of an opening 21 which connects the valve chamber 17 to the passage 15 of the second port 8, a lower part of an opening 22 which connects the valve chamber 17 to the passage 16 of the third port 9, and the like. A lower through hole 4x through which the valve stem 10a of the switching blade 10 passes is provided at the center of the lower valve chamber 4w.

[0031] 5(C), a body underside 4q on which the bottom plate 6 is placed is formed in the lower body main body part 4p. The body underside 4q is formed along the outer peripheral shape of the bottom plate 6, which allows the bottom plate 6 to be positioned and placed on the underside of the body 4. In addition, through grooves 4s (three locations) for the three supports 11 connecting the top plate 5 and the bottom plate 6 are formed in the side surface of the lower body 4B in the vertical direction along the side surface in line with the through grooves 4d of the upper body 4A.

[0032] Fig. 6 is an external view and a cross-sectional view of the second port 8 and the third port 9. Fig. 6(A) is a front view, (B) is a side view, and (C) is a cross-sectional view taken along line AA of (A).

[0033] The second port 8 and the third port 9 have the same shape. As described above, the second port 8 is connected to a pipe communicating with the outside air, and the third port 9 is connected to a pipe communicating with a ventilation device. As shown in FIG. 5, the second port 8 and the third port 9 are composed of cylindrical port main body parts 8b and 9b, pipe connection parts 8a and 9a for connecting the respective pipes, and port holding parts 8c and 9c for fitting into the mounting grooves of the body 4 and mounting and holding the port main body parts 8b and 9b to the body 4. The pipe connection parts 8a and 9a and the port holding parts 8c and 9c are formed in a cylindrical shape protruding outward along the side surfaces of the port main body parts 8b and 9b. In this embodiment, the second port 8 and the third port 9 are formed by forming and processing a hard resin material. The inner circumferential surfaces 8d and 9d of the second port 8 and the third port 9 are the flow passage 15 of the second port 8 and the flow passage 16 of the third port 9, respectively.

[0034] Fig. 7 shows an external view and a cross-sectional view of the switching blade 10. In Fig. 7, (A) is a top view, (B) is a front view, (C) is a bottom view, (D) is a side view of the front view seen from the right, and (E) is a cross-sectional view taken along line AA of (B).

[0035] The switching blade 10 is composed of a valve shaft 10a which is a rotating shaft for rotating inside the valve chamber 17, a valve portion 10b formed in an arc shape along the inner peripheral surface of the valve chamber 17, and rod-shaped connecting portions 10c (four places) which connect the valve portion 10b to the valve shaft 10a at the upper and lower ends. The valve portion 10b has an arc surface shape, and the width in the rotation direction is slightly larger than the diameter of the openings 20, 21, and 23, so that the valve portion 10b can cover each opening, and the switching blade 10 functions as a valve body. The upper end portion 10d of the valve shaft 10a is shaped like a gear to engage with a gear inside the drive unit 3.

[0036] 8 is an external view and a cross-sectional view of the top plate 5 and the bottom plate 6 that sandwich the body in the vertical direction. In FIG. 8, (A) is a front view and an AA cross-sectional view of the top plate 5, and (B) is a front view and a BB cross-sectional view of the bottom plate 6.

[0037] Both the top plate 5 and the bottom plate 6 are formed of metal sheet metal. As described above, the top plate 5 is formed along the shape of the body upper surface portion 4a of the body upper portion 4A of the body 4, and the bottom plate 6 is formed along the shape of the body lower portion main body lower portion 4p of the body lower portion 4B of the body 4. At the outer peripheral end portions, respectively, through holes 5a (three places) and through holes 6a (three places) through which the support 11 penetrates are provided. At the center of the top plate 5, a through hole 5b through which the valve shaft 10a of the switching blade 10 penetrates is provided. At the center of the bottom plate 6, a recess 6b is provided to support the lower end portion of the valve shaft 10a of the switching blade 10.

[0038] Next, a method for assembling the electric three-path shutter 1 will be described. FIG.

[0039] 9, the second port 8, the third port 9, and the switching blade 10 are arranged between the upper body 4A and the lower body 4B of the body 4, and the positioning pins 4r (four places) at the top end of the lower body 4B are inserted into the upper body fitting holes 4k (four places) at the bottom end of the upper body 4A to position them, and then the upper body 4A is assembled into the lower body 4B. Next, the top plate 5 is placed on the upper body part 4a of the upper body 4A of the body 4, and the bottom plate 6 is placed on the lower body part 4q of the lower body 4B. Then, the three pillars 11, 11, 11 are inserted through the through holes of the top plate 5, the upper body 4A, the lower body 4B, and the bottom plate 6 from above the top plate 5, and the lower ends of the pillars 11, 11, 11 inserted through the holes are screwed from below the bottom plate 6 with the set screws 12, 12, 12, to assemble and hold the second port, the third port, and the switching blade 10 to the body part 2. Furthermore, the drive unit 3 is assembled to the top plate 5 with a set screw (not shown). FIG. 10 is a perspective view showing the assembled state. In this way, the electric three-way shutter 1 has the body 4 sandwiched between the top plate 5 and the bottom plate 6 with the second port 8, the third port 9, and the switching blade 10 assembled to the body 4, and the pillars 11, 11, 11 connect and hold the top plate 5 and the bottom plate 6, and further, the drive unit 3 is assembled to the top plate 5.

[0040] The operation of the electric three-way shutter 1 assembled as described above will now be described.

[0041] Fig. 11 is a diagram for explaining a method of switching the flow path by rotating the switching blade 10 in the electric three-way shutter 1. Fig. 11 (A) shows a first type ventilation state in which the outside air communicates with the ventilation device, (B) shows a third type ventilation state in which the outside air communicates with the indoor space, and (C) shows an indoor air recirculation state in which a mixture of the outside air and the air in the indoor space is sent to the ventilation device.

[0042] As shown in (A) of Fig. 11, when the switching blade 10 is rotated by the drive unit 3 so that the valve portion 10b of the switching blade 10 blocks the opening 20 of the first port 7, the outer peripheral end of the valve portion 10b of the switching blade 10 abuts against the blocks 13A, 13B on the outer peripheral portion of the opening 20, so that the flow path 14 of the first port 7 is substantially blocked. Therefore, the flow path 15 of the second port 8 and the flow path 16 of the third port 9 communicate with each other via the valve chest 17. Then, as shown by the dashed arrows (1) and (2) in Fig. 10, the outside air communicates with the ventilation device, and a first type ventilation state in which the outside air flows into the ventilation device can be achieved.

[0043] Furthermore, as shown by arrow (4) in Fig. 11B, when the switching blade 10 is rotated by the drive unit 3 so that the valve portion 10b of the switching blade 10 blocks the opening 22 of the third port 9, the outer peripheral end of the valve portion 10b of the switching blade 10 abuts against the blocks 13B, 13D on the outer peripheral portion of the opening 22, so that the flow path 16 of the third port 9 is substantially blocked. Therefore, the flow path 15 of the second port 8 and the flow path 14 of the first port 7 communicate with each other via the valve chest 17. Then, as shown by dashed arrows (1)' and (3) in Fig. 10, the outside air communicates with the indoor space device, and a third type ventilation state in which the outside air flows into the indoor space can be achieved.

[0044] Also, when the switching blade 10 is rotated by the drive unit 3 so that the valve portion 10b of the switching blade 10 is positioned between the opening 20 of the first port 7 and the opening 21 of the second port 8, the flow path 14 of the first port 7 and the flow path 15 of the second port 8 communicate with the flow path 16 of the third port 9 through the valve chest 17, and an indoor air recirculation state can be created in which a mixture of outdoor air and indoor air is sent to the ventilation device, as shown by the dashed arrows (1)'', (2)'', and (3)'' in FIG. 10. The rotation angle of the valve portion 10b of the switching blade 10 can be set arbitrarily by the stepping motor 18 of the drive unit 3, so that the mixture ratio of outdoor air and indoor air in the mixed gas can be adjusted arbitrarily. As a result, even in areas with extremely low outdoor temperatures, air can be sent to the ventilation device at a temperature at which the heat exchanger does not freeze, so that the heat exchanger can be prevented from freezing when outdoor air is taken in.

[0045] Furthermore, the body 4 having the valve chamber 17 is molded from polystyrene foam, and the drive unit 3 including the stepping motor 18 etc. is attached to the top plate 5 (one of the two) which holds the body 4 in place. Therefore, even if extremely cold outside air is taken into the body 4, the insulating effect of the polystyrene foam prevents the outside air temperature from being transmitted to the top plate 5 (and bottom plate 6), preventing condensation from forming within the drive unit 3 and, as a result, preventing malfunctions of the drive unit 3.

[0046] Here, the electric three-path shutter 1 is an example of an electric three-path shutter, the body portion 2 is an example of a body, the drive portion 3 is an example of a drive portion, the body 4 is an example of a body main body, the top plate 5 is an example of a top plate, the bottom plate 6 is an example of a bottom plate, the first port 7 is an example of a first port, the second port 8 is an example of a second port, the third port 9 is an example of a third port, the switching blade 10 is an example of a valve body, the support 11 is an example of a connecting member, the block 13A is an example of a first block, the block 13B is an example of a second block, the block 13C is an example of a third block, the block 13D is an example of a fourth block, the valve chamber 17 is an example of a valve chamber, and the stepping motor 18 is an example of a stepping motor.

[0047] Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention should not be construed in any way as being limited by the specific descriptions in the embodiments. It should be understood that the present invention can be embodied in various forms that include various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and that all such embodiments are included within the scope of the present invention as long as they do not deviate from the spirit of the present invention.

[0048] For example, in the above embodiment of the electric three-way shutter 1, the drive unit 3 is assembled to the top plate 5, but it may also be assembled to the bottom plate 6, or it may be divided and assembled to both the top plate 5 and the bottom plate 6.

[0049] In addition, in the above embodiment of the electric three-way shutter 1, the top plate 5 and the bottom plate 6 are connected by screwing using three pillars 11, but the number of pillars 13 is not limited to three and may be four or more.

[0050] In the electric three-path shutter 1 according to the embodiment described above, the top plate 5 and the bottom plate 6 are connected using three long-screw-like supports 11, but the connecting member may not be a long screw like the support 13, and may be another connecting method as shown in FIG. 12. For example, the electric three-path shutter 100 shown in the top view of FIG. 12 (A) and the side view of FIG. 12 (B) is an example in which a U-shaped connecting member 110 is used, in which the upper and lower ends of a thin and long plate-like metal plate are bent at an angle smaller than 90°. In this way, the top plate and the bottom plate may be connected at least at three points by sandwiching the connecting members 110, 110, 110. Since the upper and lower ends of the connecting member 110 are bent at an angle smaller than 90° as described above, the top plate and the bottom plate are biased toward the body as spring forces, so that the top plate and the bottom plate can be connected and held. In this case, there is no need to screw them in like the electric three-path shutter 1, making assembly easier.

[0051] 12C is a top view and FIG. 12D is a side view of an electric three-path shutter 200, which is an example in which connecting parts 50a, 50a, 50a are provided on the outer periphery of a top plate 50, each extending in a U-shape. The lower end of the connecting part 50a is fastened to the bottom plate by a set screw 51. In this case, the support pillar 11 as in the electric three-path shutter 1 is not necessary, and therefore the number of parts can be reduced.

[0052] In addition, in the above embodiment of the electric three-way shutter 1, blocks A and B are mounted so that their contact surfaces are inclined at an angle R to the tangent of the arc along which the outer peripheral end of the valve portion 10b of the rotating switching blade 10 moves, but if the switching blade 10 rotates by 180° or more, blocks 13C and 13D may also be mounted so as to be inclined at a similar angle. [Explanation of symbols]

[0053] 1. Electric three-way shutter 2. Body section 3. Drive unit 4. Body 5. Top plate 6.Bottom plate 7. First port 8. Second port 9. Third port 10. Moulting feathers 11...post 12··Setting screw 13A, 13B, 13C, 13D Blocks 14, 15, 16 Flow path 17 Valve chamber 18. Stepping motor 20, 21, 22 Opening

Claims

1. An electric three-way shutter for use in a total heat exchange ventilation system, the electric three-way shutter comprising: A first port communicating with an indoor space; a second port communicating with outside air and a third port communicating with a ventilation device, the second port and the third port being provided perpendicular to an axis of the first port and coaxially opposed to each other; a body having a valve chamber formed therein, the valve chamber having openings each communicating with a flow passage of each of the ports; a valve body supported by the body so as to be rotatable about its own axis and rotates within the valve chamber; a drive unit that drives the valve body to rotate when energized, the body includes a main body molded from expanded polystyrene and having the valve chamber, a top plate and a bottom plate made of a hard member that vertically sandwich the main body, and a connecting member that connects the top plate and the bottom plate, An electric three-way shutter, wherein the drive unit is attached to at least one of the top plate and the bottom plate.

2. 2. The electric three-way shutter according to claim 1, characterized in that a block made of nonwoven fabric is provided on the outer edge of each opening of each port of the valve chamber so as to surround each opening and is formed at a height such that an upper surface of the block abuts against the outer peripheral edge of the valve body.

3. the blocks include a first block provided between an opening communicating with the flow passage of the first port and an opening communicating with the flow passage of the second port, a second block provided between an opening communicating with the flow passage of the first port and an opening communicating with the flow passage of the third port, a third block provided at a position facing the first block on the outer periphery of the opening communicating with the flow passage of the second port, and a fourth block provided at a position facing the second block on the outer periphery of the opening communicating with the flow passage of the third port, The electric three-way shutter according to claim 2, characterized in that at least the first block and the second block have surfaces that abut against the outer peripheral end of the valve body, the first block being inclined inward (toward the valve chamber interior) with respect to a tangent to an arc along which the outer peripheral end of the rotating valve body moves, with the first block facing the second port and the second block facing the third port.

4. The drive unit is provided with a stepping motor to adjust the rotation angle of the valve body. a first type ventilation state in which the valve body is rotated in the direction of the flow path of the first port to bring an outer circumferential end of the valve body into contact with an upper surface of the block of the opening communicating with the flow path of the first port, thereby substantially blocking the opening of the first port communicating with an indoor space, thereby communicating outside air with the ventilation device; a third type ventilation state in which the valve body is rotated in the direction of the flow path of the third port to bring an outer circumferential end of the valve body into contact with an upper surface of the block of the opening communicating with the flow path of the third port, thereby substantially blocking the opening of the third port communicating with a ventilation device, thereby communicating the outside air with the indoor space; 4. The electric three-way shutter according to claim 2 or 3, characterized in that the valve body can be rotated to an intermediate position between the first port and the second port to partially open the opening of the first port and the opening of the second port, thereby switching between an indoor air recirculation state in which a mixture of outside air and air in the indoor space is sent to a ventilation device.

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