Ventilator

Abstract

To suppress deterioration of airtightness of a container body in a ventilator.SOLUTION: A ventilator comprises: a lid (60) that opens and closes a ventilation opening (VO); a drive mechanism (70) that displaces the lid (60) between an open position and a closed position; a sealing member (65) formed between the lid (60) and a base part (47) in a position surrounding the ventilation opening (VO); and pressing units (77, 121, 122) that press the lid (60) against the base part (47).SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a ventilation device.

Background Art

[0002] Patent Document 1 discloses a ventilation device for a container. The ventilation device is provided in a refrigeration device that cools the internal space of the container body. The ventilation device has a ventilation port, an opening / closing member that opens and closes the ventilation port, and a motor that drives the opening / closing member. When the opening / closing member opens the ventilation port, the internal space of the container body and the external space communicate with each other through the ventilation port. Thereby, the internal space of the container body is ventilated. When the opening / closing member closes the ventilation port, the container body, the internal space, and the external space are blocked. Thus, in the ventilation device of Patent Document 1, the ventilation port can be opened and closed automatically rather than manually.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a structure that automatically opens and closes a ventilation port, such as the ventilation device of Patent Document 1, a gap may be formed between the lid and the base portion when the lid closes the ventilation port. In this case, since the inside and outside of the container body communicate with each other through the gap, the airtightness of the container body deteriorates.

[0005] An object of the present disclosure is to suppress a decrease in the airtightness of a container body in a ventilation device.

Means for Solving the Problems

[0006] The first embodiment relates to a ventilation device. The ventilation device comprises a base portion (47) having a ventilation opening (VO) for communicating the inside and outside of a container body (2), a lid (60) for opening and closing the ventilation opening (VO), a drive mechanism (70) for displacing the lid (60) between an open position and a closed position, a sealing member (65) formed between the base portion (47) and the lid (60) at a position surrounding the ventilation opening (VO), and pressing portions (77, 121, 122) for pressing the lid (60) toward the base portion (47). The pressing portion (77, 121, 122) has springs (77, 121, 122) that press the lid (60) toward the base portion (47).

[0007] In the first embodiment, the pressing parts (77, 121, 122) can press the closed lid (60) toward the base part (47). As a result, the sealing member (65) between the lid (60) and the base part (47) is compressed, improving the sealing performance of the gap between the lid (60) and the base part (47). Therefore, a decrease in the airtightness of the container body (2) can be suppressed. The spring (77) can press the closed lid (60) against the base (47).

[0008] In a second embodiment, the drive mechanism (70) comprises a drive source (71) and a drive shaft (72) driven by the drive source (71). The springs (77, 121, 122) are provided along the drive shaft (72) and include a first spring (77) that presses the central part of the lid (60) toward the base part (47).

[0009] In a third embodiment, the first spring (77) is helical, and the drive shaft (72) is inserted inside the first spring (77).

[0010] A fourth aspect is the first aspect, wherein the springs (77, 121, 122) are located closer to the outer circumference of the lid (60) and include auxiliary springs (121, 122) that press the lid (60) toward the base portion (47).

[0011] A fifth aspect, in the fourth aspect, includes a first auxiliary spring (121) and a second auxiliary spring (122) positioned opposite each other across the axis (X) of the drive shaft (72). The sixth aspect is the fifth aspect, wherein the base portion (47) is provided with an air intake port (48) and an exhaust port (49) formed around the axis (X) of the drive shaft (72). The air intake port (48) and the exhaust port (49) are located opposite each other with respect to the axis (X) of the drive shaft (72). The first auxiliary spring (121) and the second auxiliary spring (122) are located between the air intake port (48) and the exhaust port (49) when viewed from the axial direction.

[0012] In the seventh embodiment, as in the fifth embodiment, a first column member (123) and a second column member (124) are fixed to the outer circumference of the base portion (47), corresponding to the first auxiliary spring (121) and the second auxiliary spring (122), respectively, and extending in the axial direction of the drive shaft (72).

[0013] In the eighth aspect, as in the seventh aspect, a first connecting member (125) and a second connecting member (126) are fixed to the outer peripheral portion of the base portion (47) side of the lid (60). A first support plate (125a) and a second support plate (126a) are formed on the first connecting member (125) and the second connecting member (126), respectively.

[0014] In the ninth aspect, as in the eighth aspect, a first flange (123a) and a second flange (124a) are formed at one axial end of the first column member (123) and the second column member (124), respectively. A first auxiliary spring (121) is sandwiched between the first flange (123a) and the first support plate (125a). A second auxiliary spring (122) is sandwiched between the second flange (124a) and the second support plate (126a).

[0015] In the tenth aspect, as in the ninth aspect, the first auxiliary spring (121) and the second auxiliary spring (122) are helical. The first column member (123) and the second column member (124) are inserted into the first auxiliary spring (121) and the second auxiliary spring (122), respectively.

[0016] In the eleventh embodiment, in any one of the first to tenth embodiments, the drive mechanism (70) moves the lid (60) in the axial direction of the drive shaft (72) to adjust the distance between the outer edge of the lid (60) and the base portion (47). The opening area of ​​the ventilation opening (VO) changes according to the distance. In the twelfth aspect, as in the eleventh aspect, the drive mechanism (70) moves the lid (60) between a first position in which the sealing member (65) is compressed and a second position further away from the base portion (47) than the first position.

[0017] The 13th embodiment includes, in any one of the first to tenth embodiments, a refrigerant leak sensor (110) for detecting refrigerant leakage, and a control unit (100) that controls the drive mechanism (70) so that the lid (60) is in the closed position when the refrigerant leak sensor (110) detects refrigerant leakage.

Brief Description of the Drawings

[0018] [Figure 1] FIG. 1 is a perspective view of a refrigeration device for a container according to an embodiment, as viewed from the front. [Figure 2] FIG. 2 is a longitudinal sectional view of the refrigeration device for a container. [Figure 3] FIG. 3 is a piping system diagram of the refrigeration device for a container. [Figure 4] FIG. 4 is a block diagram showing the relationship between the control unit of the refrigeration device for a container and other devices. [Figure 5] FIG. 5 is an exploded perspective view of a ventilation device. [Figure 6] FIG. 6 is a front view of the ventilation device. [Figure 7] FIG. 7 is a sectional view taken along line VII-VII of FIG. 6. [Figure 8] FIG. 8 is an enlarged view of the portion surrounded by the dashed-dotted line indicated by B1 in FIG. 7. [Figure 9] FIG. 9 is a perspective view of the main part of the drive mechanism, as viewed from the rear side. [Figure 10] FIG. 10 is a rear view of the main part of the drive mechanism. [Figure 11] FIG. 11 is a top view of the main part of the drive mechanism. [Figure 12] FIG. 12 is a front view of an edge forming member. [Figure 13] FIG. 13 is a sectional view taken along line XIII-XIII of FIG. 12. [Figure 14] FIG. 14 is a schematic configuration diagram showing the reciprocating motion of the drive mechanism. FIG. 14(A) shows the state where the lid is in the first position. FIG. 14(B) shows the state where the lid is in the second position in the first reciprocating motion. FIG. 14(C) shows the state where the lid is in the second position in the second reciprocating motion. [Figure 15]Figure 15 is a schematic diagram showing the rotational motion of the drive mechanism. Figure 15(A) shows the lid in the closed position. Figure 15(B) shows the lid in the intermediate position. Figure 15(C) shows the lid in the fully open position. [Figure 16] Figure 16 is a flowchart of the basic operation of the ventilation system. [Figure 17] Figure 17 is a flowchart of the initialization control. [Figure 18] Figure 18 is a front view of the ventilation device of Modification 1. [Figure 19] Figure 19 is a cross-sectional view of the line XIX-XIX in Figure 18. [Figure 20] Figure 20 is a schematic diagram showing the reciprocating motion of the lid in Modification Example 1. Figure 20(A) shows the lid in the first position (closed position). Figure 20(B) shows the lid in the second position (open position). [Modes for carrying out the invention]

[0019] The embodiments of this disclosure will be described in detail below with reference to the drawings. However, this disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of ​​this disclosure. Since the drawings are for conceptual explanation of this disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for ease of understanding.

[0020] (1) Overall container configuration The ventilation device (40) is applied to the container (1). The overall configuration of the container (1) in this embodiment will be described with reference to Figures 1 to 3. In the following description, the terms "front," "back," "left," "right," "up," and "down" refer to the directions indicated by the arrows in Figure 1.

[0021] Container (1) is used for maritime transport. Container (1) is a refrigerated container that cools the air inside it. Container (1) consists of a container body (2) and a container refrigeration unit (10). The container body (2) stores items such as food and plants. The container refrigeration unit (10) cools the internal space (3) of the container body (2). As shown in Figure 2, a front opening (4) is formed on the front of the container body (2). The container refrigeration unit (10) is attached to the container body (2) so as to close the front opening (4) of the container body (2).

[0022] (2) Refrigeration equipment for containers The container refrigeration unit (10) has a casing (11). The casing (11) forms the lid of the front opening (4) of the container body (2). The casing (11) has a casing body (12) and a partition plate (13). The casing body (12) separates the external space (5), which is the outside space of the container body (2), from the internal space (3). The partition plate (13) is located on the rear side (back side) of the casing (11).

[0023] The container refrigeration system (10) includes a compressor (25), an external heat exchanger (26), and an external fan (27) as equipment located outside the container. The container refrigeration system (10) also includes an internal heat exchanger (29) and an internal fan (30) as equipment located inside the container.

[0024] (2-1) Casing body As shown in Figure 2, the casing body (12) has a flat plate portion (12a) and a recess (12b). The flat plate portion (12a) is formed on the upper part of the casing body (12) so as to be substantially flush with the front opening (4) of the casing (11). As shown in Figure 1, the flat plate portion (12a) is provided with an inspection window (22) and a ventilation device (40). The inspection window (22) is located on the right side of the flat plate portion (12a). The ventilation device (40) is located on the left side of the flat plate portion (12a). The inspection window (22) is a transparent window for checking the inside of the casing body (12). The ventilation device (40) ventilates the interior space (3).

[0025] The recess (12b) is formed in the lower part of the casing (11). The recess (12b) is recessed from the lower end of the flat plate portion (12a) toward the rear. An external storage space (14) is formed in front of the recess (12b). An internal storage space (15) is formed above the recess (12b) between the flat plate portion (12a) and the partition plate (13). The lower end of the recess (12b) constitutes the bottom plate (12c). The bottom plate (12c) extends across both the left and right ends of the casing body (12).

[0026] The casing body (12) is constructed by stacking an outer casing (16), an insulation layer (17), and an inner casing (18) in the thickness direction (front-to-back direction). The outer casing (16) faces the external space (5). The inner casing (18) faces the interior of the chamber. The insulation layer (17) is provided between the outer casing (16) and the inner casing (18). The outer casing (16) is made of aluminum. The inner casing (18) is made of fiberglass reinforced plastic (FRP). The insulation layer (17) is made of foamed resin.

[0027] (2-2) Partition plates and air passages As shown in Figure 2, the partition plate (13) is a plate-shaped member located behind the recess (12b). The partition plate (13) extends vertically at a predetermined distance from the rear surface of the recess (12b). An internal passage (19) through which internal air flows is formed between the casing body (12) and the partition plate (13). An inlet (20) is formed between the upper end of the partition plate (13) and the upper wall (2a) of the container body (2). The inlet (20) connects the internal space (3) with the inlet end of the internal passage (19). An outlet (21) is formed between the lower end of the partition plate (13) and the lower wall (2b) of the container body (2). The outlet (21) connects the internal space (3) with the outlet end of the internal passage (19).

[0028] (2-3) Components of the exterior space The external storage space (14) is equipped with a compressor (25), an external heat exchanger (26), and an external fan (27). The compressor (25) is installed on the bottom plate (12c) of the casing (11). The compressor (25) is positioned towards the lower part of the external storage space (14). The compressor (25) is positioned towards the right side of the external storage space (14).

[0029] The external fan (27) is located near the top of the external storage space (14). The external fan (27) is a propeller fan. As shown in Figure 2, an external passage (28) through which outside air flows is formed behind the external fan (27).

[0030] The external heat exchanger (26) is installed in the external storage space (14) at a height between the external fan (27) and the compressor (25). The external heat exchanger (26) is located in the external passage (28). The external heat exchanger (26) is a fin-and-tube type heat exchanger.

[0031] (2-4) Components of the interior space The internal storage space (15) is equipped with an internal heat exchanger (29) and an internal fan (30). The internal heat exchanger (29) is supported by the casing (11) so as to extend across the casing body (12) and the partition plate (13). The internal heat exchanger (29) is a fin-and-tube type heat exchanger.

[0032] (2-5) Refrigerant Circuit As shown in Figure 3, the container refrigeration unit (10) has a refrigerant circuit (R). The refrigerant circuit (R) is filled with refrigerant. The refrigerant circuit (R) performs a vapor compression type refrigeration cycle by circulating the refrigerant.

[0033] The refrigerant in the refrigerant circuit (R) has a higher density than air. In this example, the refrigerant is carbon dioxide (CO2), a natural refrigerant. Natural refrigerants have zero ozone depletion potential, low global warming potential, and a low environmental impact. Other refrigerants may include propane (R290), ammonia (R717), methane (R50), ethane (R170), butane (R600), and isobutane (R600a). Other refrigerants may include difluoromethane (R32), 2,3,3,3-tetrafluoropropene (HFO-1234yf), and 1,3,3,3-tetrafluoropropene (HFO-1234ze). The refrigerant may be a single refrigerant or a mixed refrigerant consisting of other refrigerants. A mixed refrigerant may consist of two types: 2,3,3,3-tetrafluoropropene (HFO-1234yf) and difluoromethane (R32). The mixed refrigerant may also be a refrigerant (R454C) consisting of 78.5% by weight of 2,3,3,3-tetrafluoropropene (HFO-1234yf) and 21.5% by weight of difluoromethane (R32).

[0034] The refrigerant circuit (R) mainly comprises a compressor (25), an external heat exchanger (26), an expansion valve (31), and an internal heat exchanger (29).

[0035] The compressor (25) compresses the inhaled refrigerant. The compressor (25) discharges the compressed refrigerant. A discharge pipe (32) is connected to the discharge section of the compressor (25). A suction pipe (33) is connected to the suction section of the compressor (25). An accumulator (34) is provided in the suction pipe (33). The accumulator (34) is a container for storing liquid refrigerant.

[0036] The external heat exchanger (26) exchanges heat between the refrigerant flowing inside it and the outside air. The gas end of the external heat exchanger (26) is in communication with the discharge pipe (32). The liquid end of the external heat exchanger (26) is connected to the liquid end of the internal heat exchanger (29) via the liquid pipe (35). The external heat exchanger (26) functions as a heat radiator (condenser) through which the refrigerant releases heat to the air.

[0037] The expansion valve (31) is installed in the liquid pipe (35). The expansion valve (31) reduces the pressure of the high-pressure refrigerant to a low-pressure refrigerant. The expansion valve (31) is an electronically operated expansion valve with an adjustable opening. A receiver (36) is installed between the external heat exchanger (26) and the expansion valve (31) in the liquid pipe (35). The receiver (36) is a container for storing excess refrigerant in the refrigerant circuit (R).

[0038] The internal heat exchanger (29) exchanges heat between the refrigerant flowing inside it and the air inside the refrigerator. The gas end of the internal heat exchanger (29) is in communication with the suction pipe (33). The internal heat exchanger (29) functions as an evaporator in which the refrigerant absorbs heat from the air.

[0039] The refrigerant circuit (R) has a bypass pipe (37). The inlet end of the bypass pipe (37) is in communication with the discharge pipe (32), and the outlet end of the bypass pipe (37) is in communication with the liquid pipe (35). The bypass pipe (37) sends the refrigerant discharged from the compressor (25) to the internal heat exchanger (29), bypassing the external heat exchanger (26).

[0040] The refrigerant circuit (R) is provided with a first valve (38) and a second valve (39). The first valve (38) is located between the discharge side of the compressor (25) and the gas end of the external heat exchanger (26), and downstream of the connection point of the bypass pipe (37). The second valve (39) is located in the bypass pipe (37). The first valve (38) and the second valve (39) are composed of electromagnetic on / off valves. The first valve (38) and the second valve (39) may also be flow control valves with adjustable opening degrees.

[0041] (2-6) Operating procedures The container refrigeration unit (10) performs both cooling and defrosting operations.

[0042] During cooling operation, a refrigerant compressed by the compressor (25) condenses in the external heat exchanger (26), is depressurized by the expansion valve (31), and evaporates in the internal heat exchanger (29), thus completing the refrigeration cycle. Air flowing out from the internal space (3) into the internal passage (19) is cooled in the internal heat exchanger (29), which functions as an evaporator. The cooled air is then sent back into the internal space (3).

[0043] During defrosting, the refrigerant compressed by the compressor (25) flows through the bypass pipe (37) and then through the internal heat exchanger (29). The frost on the surface of the internal heat exchanger (29) melts due to the heat of the refrigerant flowing inside the internal heat exchanger (29).

[0044] (3) Ventilation system The ventilation device (40) is described in detail below. In the following description, "axial direction" corresponds to the direction extending from the axis (X) of the drive shaft (72). "Circumferential direction" corresponds to the rotational direction of the drive shaft (72). "Radial direction" corresponds to the direction connecting the axis (X) of the drive shaft (72) and the outer surface of the drive shaft (72).

[0045] (3-1) Overall structure The ventilation device (40) shown in Figures 5 to 7 is a container ventilation device that ventilates the interior space (3) of the container body (2). The ventilation device (40) of this embodiment has an air supply function that supplies outside air, which is the outside air, to the interior space (3), and an exhaust function that discharges the interior air to the outside space (5).

[0046] As shown in Figure 2, the ventilation device (40) is installed in a ventilation opening (6) formed on the front surface of the casing body (12). The ventilation opening (6) penetrates the casing body (12) from front to back. The ventilation opening (6) is formed across the outer casing (16), the insulation layer (17), and the inner casing (18).

[0047] The ventilation device (40) has an air supply passage (P1) and an exhaust passage (P2). The air supply passage (P1) and the exhaust passage (P2) connect the interior space (3) and the exterior space (5). Specifically, the inlet end of the air supply passage (P1) communicates with the exterior space (5). The outlet end of the air supply passage (P1) communicates with the primary side (upstream side) of the interior fan (30) in the interior passage (19). The inlet end of the exhaust passage (P2) communicates with the secondary side (downstream side) of the interior fan (30) in the interior passage (19). The outlet end of the exhaust passage (P2) communicates with the exterior space (5).

[0048] As shown in Figures 5 and 7, the ventilation device (40) comprises, in order from rear to front, a ventilation case (41), a drive mechanism (70), an air supply duct (45) and an exhaust duct (46), a base (47), an edge forming member (50), a packing (65), and a lid (60).

[0049] (3-2) Ventilation case The ventilation case (41) houses the drive mechanism (70), the supply air duct (45), and the exhaust air duct (46). The ventilation case (41) has a rectangular cylindrical frame (41a), a side plate (41b) that closes the rear opening of the frame (41a), and a flange (41c) that extends radially outward from the front edge of the frame (41a). The frame (41a) is embedded inside the insulation layer (17). The side plate (41b) is rectangular in shape. A case-side supply air opening (42) is formed at the top of the side plate (41b). A case-side exhaust opening (43) is formed at the bottom of the side plate (41b). The case-side supply air opening (42) and the case-side exhaust opening (43) are horizontally elongated rectangles.

[0050] The case-side air intake opening (42) constitutes part of the air intake passage (P1). The case-side air intake opening (42) opens toward the primary side (upstream side) of the internal fan (30) in the internal passage (19). The case-side exhaust opening (43) constitutes part of the exhaust passage (P2). The case-side exhaust opening (43) opens toward the secondary side (downstream side) of the internal fan (30) in the internal passage (19).

[0051] A housing frame (44) is provided in the center of the side plate (41b). The housing frame (44) is cylindrical and protrudes forward from the side plate (41b). A drive mechanism (70) is arranged inside the housing frame (44).

[0052] (3-3) Intake ducts and exhaust ducts The supply air duct (45) forms part of the supply air passage (P1). The exhaust air duct (46) forms part of the exhaust air passage (P2). The supply air duct (45) and the exhaust air duct (46) are housed inside the ventilation case (41). The supply air duct (45) and the exhaust air duct (46) are horizontally elongated cylindrical shapes. The passage cross-section of the supply air duct (45) and the exhaust air duct (46) narrows towards the front. The supply air duct (45) is attached to the side plate (41b) so as to connect to the case-side supply air opening (42). The exhaust air duct (46) is attached to the side plate (41b) so as to connect to the case-side exhaust opening (43).

[0053] (3-4) Base section The base portion (47) closes the front opening of the ventilation case (41). The base portion (47) faces the external space (5) and constitutes part of the external casing (16). The base portion (47) is made of aluminum. The base portion (47) has a rectangular plate-shaped substrate (47a) and a circular base-side recess (47b) that is recessed to the rear from the center of the substrate (47a). The substrate (47a) is fastened to the flange (41c) of the ventilation case (41). The substrate (47a) is exposed to the external space (5).

[0054] A cylindrical space, flattened in the front-to-back direction, is formed inside the base-side recess (47b). An air intake port (48) and an exhaust port (49) are formed at the bottom, which is the rear part of the base-side recess (47b). The air intake port (48) and the exhaust port (49) are formed around the axis of the central axis (X). The air intake port (48) is formed at the top of the base-side recess (47b), and the exhaust port (49) is formed at the bottom of the base-side recess (47b). The air intake port (48) and the exhaust port (49) are roughly fan-shaped. The air intake port (48) and the exhaust port (49) extend in the circumferential direction. The air intake port (48) and the exhaust port (49) are positioned opposite each other with the central axis (X) in between.

[0055] The air intake port (48) is connected to the air intake duct (45). The air intake port (48) constitutes part of the air intake passage (P1). The exhaust port (49) is connected to the exhaust duct (46). The exhaust port (49) constitutes part of the exhaust passage (P2). The air intake port (48) and the exhaust port (49) constitute a ventilation opening (VO) for connecting the internal space (3) of the container body (2) with the external space (5).

[0056] A first through-hole (47c) is formed in the center of the bottom of the base-side recess (47b). The first through-hole (47c) is circular in shape.

[0057] (3-5) Edge forming member The edge forming member (50) has the function of improving the sealing performance of the packing (65). The edge forming member (50) is positioned between the base portion (47) and the packing (65). The edge forming member (50) is made of a resin material such as ABS resin. The edge forming member (50) has a cylindrical boss portion (51) that is fitted into the first through hole (47c) and an edge forming plate (52) that extends radially outward from the front end of the boss portion (51). In this embodiment, the edge forming member (50) is fixed to the base portion (47).

[0058] The edge-forming plate (52) has a disc portion (52a) and a first extension portion (52b) and a second extension portion (52c) extending radially outward from the disc portion (52a). The disc portion (52a) is formed in the center of the edge-forming plate (52). When viewed from the axial direction, the disc portion (52a) is circular in shape, and the first extension portion (52b) and the second extension portion (52c) are substantially fan-shaped or arc-shaped. The first extension portion (52b) and the second extension portion (52c) are arranged at equal intervals in the circumferential direction. The first extension portion (52b) and the second extension portion (52c) are located opposite each other with respect to the axis (X).

[0059] A second through hole (52d) is formed in the disc portion (52a). The second through hole (52d) is circular when viewed from the axial direction.

[0060] An air intake port (53) is formed in the first extension (52b), and an exhaust port (54) is formed in the second extension (52c). The air intake port (53) is approximately the same shape and size as the air intake port (48). The air intake port (53) overlaps with the air intake port (48) in the axial direction. The exhaust port (54) is approximately the same shape and size as the exhaust port (49). The exhaust port (54) overlaps with the exhaust port (49) in the axial direction. As shown in Figure 6, a protrusion (55) is formed on the front surface of the edge forming plate (52). Details of the protrusion (55) will be described later.

[0061] (3-6) Lid The lid (60) is positioned inside the base-side recess (47b) so as to face the external space (5). The lid (60) opens and closes the air intake (48) and exhaust (49), which are ventilation openings. The lid (60) is disc-shaped with an axis (X) at its center. The lid (60) performs rotational and reciprocating motions when driven by a drive mechanism (70). In rotational motion, the lid (60) rotates around the axis (X). In reciprocating motion, the lid (60) moves axially along the axis (X). The lid (60) is made of, for example, aluminum.

[0062] The lid (60) has openings, namely a lid-side air intake opening (61) and a lid-side exhaust opening (62). The lid-side air intake opening (61) and the lid-side exhaust opening (62) are roughly fan-shaped. The lid-side air intake opening (61) and the lid-side exhaust opening (62) extend in the circumferential direction. The lid-side air intake opening (61) and the lid-side exhaust opening (62) are located opposite each other with respect to the axis (X). The lid-side air intake opening (61) is roughly the same shape and size as the air intake port (48) and the air intake communication port (53). The lid-side exhaust opening (62) is roughly the same shape and size as the exhaust port (49) and the exhaust communication port (54).

[0063] The lid-side air intake opening (61) is configured to communicate with the air intake port (48) and the air intake communication port (53) as the lid (60) rotates. The lid-side exhaust opening (62) is configured to communicate with the exhaust port (49) and the exhaust communication port (54) as the lid (60) rotates. The lid-side air intake opening (61) constitutes part of the air intake passage (P1), and the lid-side exhaust opening (62) constitutes part of the exhaust passage (P2). The lid-side air intake opening (61) and the lid-side exhaust opening (62) constitute a lid-side opening (CO) whose overlapping area with the ventilation opening (VO) is adjustable.

[0064] (3-7) Packing The packing (65) is positioned inside the base-side recess (47b). The packing (65) is formed between the base (47) and the lid (60) at a position surrounding the ventilation openings, namely the air intake (48) and the exhaust (49). More precisely, the packing (65) is positioned between the lid (60) and the edge forming plate (52) at a position surrounding the air intake communication opening (53) and the exhaust communication opening (54). The packing (65) seals the gap between the lid (60) and the base (47). The sealing member (65) prevents the external space (5) and the internal space (3) from communicating through the gap.

[0065] The packing (65) is disc-shaped with respect to the axis (X). The packing (65) is fixed to the rear surface of the lid (60). The packing (65) is made of an elastic resin material. The packing (65) is elastically deformed when compressed in the axial direction (thickness direction). The packing (65) is preferably a closed-cell body, and is made of polyethylene foam, for example.

[0066] The packing (65) has a packing-side air intake opening (66), a packing-side exhaust opening (67), and a central hole (68). The packing-side air intake opening (66) is approximately the same shape and size as the lid-side air intake opening (61). When the packing (65) is fixed to the rear side of the lid (60), the entire lid-side air intake opening (61) and the entire packing-side air intake opening (66) overlap in the axial direction. The packing-side exhaust opening (67) is approximately the same shape and size as the lid-side exhaust opening (62). When the packing (65) is fixed to the rear side of the lid (60), the entire lid-side exhaust opening (62) and the entire packing-side exhaust opening (67) overlap in the axial direction. The central hole (68) is approximately the same shape and size as the first insertion hole (47c) and the second insertion hole (52d). The central hole (68) axially overlaps with the first insertion hole (47c) and the second insertion hole (52d).

[0067] The packing (65) is configured to rotate together with the lid (60). The packing-side air intake opening (66) is configured to communicate with the air intake port (48) and the air intake communication port (53) as the lid (60) rotates. The packing-side exhaust opening (67) is configured to communicate with the exhaust port (49) and the exhaust communication port (54) as the lid (60) rotates. The packing-side air intake opening (66) constitutes part of the air intake passage (P1), and the packing-side exhaust opening (67) constitutes part of the exhaust passage (P2).

[0068] (3-8) Drive mechanism The configuration of the drive mechanism (70) will be explained with reference to Figures 5 to 12.

[0069] (3-8-1) Overall structure The drive mechanism (70) drives the lid (60). The drive mechanism (70) displaces the lid (60) between a closed position where the lid (60) closes the ventilation opening (VO) and an open position (more precisely, a fully open position) where the lid (60) opens the ventilation opening (VO). The drive mechanism (70) has a motor (71) which is a drive source and a drive shaft (72) driven by the motor (71). The drive mechanism (70) in this embodiment is configured to perform rotational motion, which rotates the lid (60) in accordance with the rotation of the drive shaft (72), and reciprocating motion, which moves the lid (60) back and forth in a first axial direction in accordance with the rotation of the drive shaft (72). The drive mechanism (70) has a rod (73) connected to the drive shaft (72) and a cam mechanism (80) connected to the lid (60). The drive mechanism (70) includes a drive case (75) and a transmission mechanism (76) that transmits the rotational force of the output shaft (71a) of the motor (71) to the drive shaft (72). The drive mechanism (70) is provided with a spring (77) that presses the lid (60) toward the base portion (47).

[0070] As shown in Figures 5 and 7, the aforementioned housing frame (44) has a cylindrical first housing space (44a) and a rectangular prism-shaped second housing space (44b). The cam mechanism (80) and the drive shaft (72) are housed in the first housing space (44a). The motor (71) is housed in the second housing space (44b). The second housing space (44b) is a sealed space tightly separated from the first housing space (44a). This prevents water droplets and other substances from leaking around the motor (71).

[0071] (3-8-2) Motors and transmission mechanisms The motor (71) is a stepping motor. The output shaft (71a) of the motor (71) extends backward parallel to the axis (X). The motor (71) rotates its output shaft (71a) in a reversible manner.

[0072] A transmission mechanism (76) is provided on the rear side of the motor (71) and drive shaft (72). The transmission mechanism (76) in this embodiment has a pinion (76a), a first gear (76b), and a second gear (76c). The pinion (76a) is fixed to the output shaft (71a). The first gear (76b) meshes with the pinion (76a) and the second gear (76c). The second gear (76c) is connected to the rear end of the drive shaft (72). When the output shaft (71a) of the motor (71) rotates, this rotational force is transmitted to the drive shaft (72) via the pinion (76a), the first gear (76b), and the second gear (76c). As a result, the drive shaft (72) is rotationally driven by the motor (71). The drive shaft (72) is configured to be rotatable in the first rotational direction (R1) and the second rotational direction (R2) shown in Figure 10.

[0073] (3-8-3) Drive shaft The drive shaft (72) extends from the second gear (76c) toward the lid (60) in the direction of the lid's thickness. The direction in which the axis (X) of the drive shaft (72) extends corresponds to the direction of the lid's thickness, the airflow direction of the air intake passage (P1) and the air exhaust passage (P2). The drive shaft (72) is made of a metal material such as SUS.

[0074] The drive shaft (72) is rotatably fixed to the fixed plate (78) via a fastener (79). The fixed plate (78) rotatably supports the drive shaft (72). The fastener (79) prevents axial movement of the drive shaft (72).

[0075] A disc-shaped flange (72a) is formed at the end (front end) of the drive shaft (72) on the lid (60) side. The flange (72a) is coaxial with the axis (X) of the drive shaft (72). The outer diameter of the flange (72a) is larger than the outer diameter of the drive shaft (72). The flange (72a) forms a support plate that supports one end of the spring (77).

[0076] (3-8-4) Rod As shown in Figures 9 to 11, three rods (73) are fixed to the drive shaft (72). Each rod (73) is a rod-shaped object extending radially outward from the outer surface of the drive shaft (72). Each rod (73) extends in a direction perpendicular to the axis (X). The three rods (73) are arranged at equal intervals in the circumferential direction.

[0077] The number of rods (73) may be one or two, but it is preferable to have three or more. By having three or more rods (73), the force acting between the rods (73) and the cam mechanism (80) can be distributed. This stabilizes the rotational and reciprocating motion of the lid (60). If the number of rods (73) is four or more, the load torque of the motor (71) becomes excessively large. For this reason, it is even more preferable to have three rods (73).

[0078] Each rod (73) has a rod body (73a) connected to a drive shaft (72) and a ring-shaped bearing (73b) provided at the radially outward end of the rod body (73a). The bearing (73b) is rotatably supported on the rod body (73a), for example, by a bolt (73c). The bearing (73b) is configured to rotate about the axis of the rod body (73a). The axis of rotation of the bearing (73b) is aligned with the radial direction of the drive shaft (72). The bearing (73b) is in contact with the contact surface (82) of the cam mechanism (80). When the bearing (73b) is in contact with the contact surface (82), the bearing (73b) rotates about its axis. This reduces the frictional force between the rod (73) and the contact surface (82) of the cam mechanism (80). The bearing (73b) constitutes a low-friction section that reduces the frictional force (frictional resistance) between the cam mechanism (80) and the rod (73).

[0079] The bearing (73b) is preferably made of a material with higher wear resistance than the rod body (73a). The rod body (73a) is made of a metal material such as SUS. The bearing (73b) is made of a resin material such as polyacetal.

[0080] (3-8-5) Cam mechanism The cam mechanism (80) is connected to the lid (60) and transmits power from the drive shaft (72) to the lid (60). The cam mechanism (80) has a cylindrical shape coaxial with the axis (X). The front end of the cam mechanism (80) is fastened to the center of the rear surface of the lid (60).

[0081] The cam mechanism (80) has a cylindrical peripheral wall (81) coaxial with the axis (X). At the end of the peripheral wall (81) on the rod (73) side, a contact surface (82) is formed in which the bearing (73b), which is the contact part of the rod (73), makes contact. The contact surface (82) includes a first transmission part (C1) and a second transmission part (C2). The first transmission part (C1) is a contact surface for transmitting the rotational force of the drive shaft (72) to the lid (60) to cause the lid (60) to rotate. The second transmission part (C2) is a contact surface for transmitting the rotational force of the drive shaft (72) to the lid (60) to cause the lid (60) to reciprocate.

[0082] The structure of the contact surface (82) will be described in more detail. Three projection plates (83) are formed at the rod (73) side end of the peripheral wall (81). The number of projection plates (83) is the same as the number of rods (73). The number of projection plates (83) may be one, two, or four or more, and may differ from the number of rods (73). The projection plates (83) are rectangular plates with the same thickness as the peripheral wall (81).

[0083] The portion of the contact surface (82) between adjacent projection plates (83) in the circumferential direction is recessed in a V-shape toward the lid (60). In this recessed portion, a first inclined surface (84) and a second inclined surface (85) are formed, flanking the top (P). The top (P) is the portion of the contact surface (82) of the circumferential wall (81) that has the shortest axial distance from the lid (60). The top (P) is located midway in the circumferential direction between adjacent projection plates (83). The first inclined surface (84) extends from the top (P) along the first rotational direction (R1). The first inclined surface (84) is inclined to approach the rod (73) as it progresses in the first rotational direction (R1). The second inclined surface (85) extends from the top (P) along the second rotational direction. The second inclined surface (85) is inclined to approach the rod (73) as it progresses in the second rotational direction. The inclination angles of the first inclined surface (84) and the second inclined surface (85) with respect to the plane perpendicular to the axis (X) of the drive shaft (72) are equal to each other. The circumferential lengths of the first inclined surface (84) and the second inclined surface (85) are equal to each other. The first inclined surface (84) and the second inclined surface (85) are symmetrical with respect to the apex (P).

[0084] The first inclined surface (84) and the second inclined surface (85) constitute the first transmission section (C1) with which the rod (73) makes contact. The first inclined surface (84) and the second inclined surface (85) are inclined with respect to a plane perpendicular to the axis (X). As a result, the first inclined surface (84) and the second inclined surface (85) convert the rotational force acting from the rod (73) into an axial force and transmit it to the lid (60).

[0085] A first end face (83a) is formed on the side of the projection plate (83) closest to the first inclined surface (84). The first end face (83a) is the side of the projection plate (83) facing the second rotation direction (R2). A second end face (83b) is formed on the side of the projection plate (83) closest to the second inclined surface (85). The second end face (83b) is the side of the projection plate (83) facing the first rotation direction (R1). The first end face (83a) and the second end face (83b) constitute a second transmission section (C2) in contact with the rod (73). The first end face (83a) and the second end face (83b) have surfaces aligned with the axis (X), thereby transmitting the rotational force acting from the rod (73) directly to the lid (60).

[0086] A first flat surface (86) is formed between the first inclined surface (84) and the first end surface (83a) of the contact surface (82). A second flat surface (87) is formed between the second inclined surface (85) and the second end surface (83b) of the contact surface (82). The first flat surface (86) and the second flat surface (87) are aligned with a plane perpendicular to the axis (X). The circumferential lengths of the first flat surface (86) and the second flat surface (87) are approximately equal to the diameter of the contact portion of the rod (73), specifically, the diameter of the bearing (73b).

[0087] As shown in Figure 8, a roughly disc-shaped inner plate (90) is formed inside the cam mechanism (80). In the center of the inner plate (90), an annular recess (91) is formed that is recessed toward the rod (73) side, and an annular projection (92) is formed that is projected toward the lid (60) side. In the center of the support base plate (91a), which is the bottom of the annular recess (91), a shaft hole (91b) is formed through which the drive shaft (72) passes. The annular projection (92) is cylindrical and surrounds the drive shaft (72). Between the flange (72a), the support base plate (91a) of the annular recess (91), the annular projection (92), and the drive shaft (72), a spring housing space (93) is formed in which a spring (77) is housed.

[0088] As shown in Figure 9, a plurality of ribs (94) are provided on the rod (73) side surface of the support base plate (91a) of the cam mechanism (80). The plurality of ribs (94) extend radially from the outer circumferential surface of the annular recess (91) to the inner circumferential surface of the peripheral wall (81). The plurality of ribs (94) are arranged at equal intervals in the circumferential direction. The ribs (94) constitute a reinforcing portion that reinforces the support base plate (91a) to which the pressing force of the spring (77) acts.

[0089] (3-8-5) Spring As shown in Figure 8, the spring (77) in this embodiment is provided in the drive mechanism (70). The spring (77) constitutes a pressing part that presses the lid (60) toward the base part (47). The spring (77) is helical. The spring (77) extends axially as a whole by pivoting around its axis (X). The spring (77) is made of a metal wire such as SUS or tungsten.

[0090] The drive shaft (72) is positioned inside the spring (77). In other words, the spring (77) is spiral-shaped and rotates to surround the drive shaft (72).

[0091] One end of the spring (77) contacts the flange (72a) of the drive shaft (72). The other end of the spring (77) may or may not be fixed to the flange (72a). The other end of the spring (77) contacts the support base plate (91a). In this way, the spring (77) is held in place by being sandwiched between the flange (72a) and the support base plate (91a). The flange (72a) and the support base plate (91a) face each other and form a first surface and a second surface that hold the spring (77). The first surface is provided on the drive shaft (72), and the second surface is provided on the cam mechanism (80) which is connected to the lid (60).

[0092] As described above, the drive shaft (72) is prohibited from moving in the axial direction. Therefore, the biasing force of the spring (77) acts to move the cam mechanism (80) backward. This biasing force presses the cover (60) connected to the cam mechanism (80) toward the base portion (47). When the cover (60) is pressed toward the base portion (47), the packing (65) between the cover (60) and the base portion (47) is compressed in the thickness direction. This improves the sealing performance of the packing (65).

[0093] (3-9) Details of the edge forming plate As shown in Figures 6, 12, and 13, a protrusion (55) is provided between the packing (65) and the base portion (47), projecting toward the packing (65). The protrusion (55) is tapered, becoming narrower toward the packing (65). The protrusion (55) compresses the packing (65), thereby improving the sealing performance of the packing (65). The protrusion (55) includes an air supply side protrusion (56) corresponding to the air supply port (53), an exhaust side protrusion (55) corresponding to the exhaust port (54), and a central protrusion (58) corresponding to the second insertion hole (52d).

[0094] The air supply side projection (56) is in the shape of a closed loop surrounding the air supply port (53). When the lid (60) is in the fully closed position, the air supply side projection (56) makes line contact with the portion of the packing (65) corresponding to the outer edge of the air supply port (53). This improves the sealing performance between the packing (65) and the outer edge of the air supply port (53).

[0095] The exhaust-side protrusion (57) is in the shape of a closed loop surrounding the exhaust communication port (54). When the lid (60) is in the fully closed position, the exhaust-side protrusion (57) makes line contact with the portion of the packing (65) corresponding to the outer edge of the exhaust communication port (54). This improves the sealing performance between the packing (65) and the outer edge of the exhaust communication port (54).

[0096] The structure of the intake side projection (56) and the exhaust side projection (57) is basically the same, but they may have different structures. The intake side projection (56) and the exhaust side projection (57) each have an outer circumference (55a), an inner circumference (55b), a first side edge (55c), and a second side edge (55d), respectively. The outer circumference (55a) is located near the outer circumference of the edge forming plate (52). When viewed from the axial direction, the outer circumference (55a) is arc-shaped along the outer circumference of the edge forming plate (52). The inner circumference (55b) is located near the inner circumference of the edge forming plate (52), i.e., the second insertion hole (52d). The inner circumference (55b) is arc-shaped along the inner circumference of the edge forming plate (52).

[0097] The first side edge (55c) is continuous with one end of the outer circumference (55a) and the inner circumference (55b) in the circumferential direction. Here, each end corresponds to the end in the first rotational direction (R1). The first side edge (55c) extends substantially in a straight line across one end of the outer circumference (55a) and one end of the inner circumference (55b).

[0098] The second side edge (55d) is continuous with the other ends of the outer circumference (55a) and the inner circumference (55b) in the circumferential direction. Here, each other end corresponds to the end in the second rotational direction (R2). The second side edge (55d) extends in a substantially arc shape so as to span the other end of the outer circumference (55a) and the other end of the inner circumference (55b). The second side edge (55d) is an arc shape that bulges toward the first rotational direction (R1).

[0099] The central protrusion (58) forms a closed loop surrounding the second through hole (52d). The central protrusion (58) makes line contact with the portion of the packing (65) corresponding to the outer edge of the second through hole (52d). This improves the sealing performance between the packing (65) and the outer edge of the second through hole (52d).

[0100] The protruding height of the convex portion (55) increases from the center of the lid (60) toward the outer edge of the lid (60). In other words, the protruding height of the convex portion (55) increases toward the radially outward direction of the edge forming plate (52). Here, the spring (77) presses the center of the lid (60) toward the base portion (47) when viewed from the axial direction. Therefore, the pressing force acting on the lid (60) decreases from the center of the lid (60) toward the outer edge. As a result, the compressive force of the packing (65) due to the spring (77) decreases toward the outer edge of the lid (60). In contrast, by increasing the protruding height of the convex portion (55) toward the radially outward direction of the edge forming plate (52), the compressive force of the packing (65) can be made uniform over the entire radial direction. As a result, the sealing performance of the packing (65) can be improved.

[0101] Specifically, as shown in Figure 13, the protrusion height h1 of the outer circumference (55a) is greater than h2, and h2 is greater than h3, where h2 is the protrusion height of the inner circumference (55b) and h3 is the protrusion height of the central protrusion (58). The protrusion height h1 of the outer circumference (55a) is equal throughout its entire length. The protrusion height h2 of the inner circumference (9) is equal throughout its entire length. The protrusion height of the central protrusion (58) is equal throughout its entire length.

[0102] The protruding height h4 of the first side edge (55c) increases from the center of the lid (60) toward the outer edge of the lid (60). In other words, the protruding height h4 of the first side edge (55c) increases toward the radially outward direction of the edge forming plate (52).

[0103] The protruding height h5 of the second side edge (55d) increases from the center of the lid (60) toward the outer edge of the lid (60). In other words, the protruding height h5 of the second side edge (55d) increases toward the radially outward direction of the edge forming plate (52).

[0104] (3-10) Restriction mechanism The ventilation device (40) has a limiting mechanism for restricting the rotation of the lid (60) relative to the base (47). As shown in Figure 6, the limiting mechanism has a first lid-side protrusion (63) and a second lid-side protrusion (64) provided on the lid (60), and a first pin (95) and a second pin (96) provided on the base (47).

[0105] The first lid-side protrusion (63) and the second lid-side protrusion (64) project radially outward from the outer edge of the lid (60). The first lid-side protrusion (63) and the second lid-side protrusion (64) are offset by approximately 90 degrees in the circumferential direction. The first lid-side protrusion (63) is located near the lid-side air intake opening (61) on the outer edge of the lid (60). The second lid-side protrusion (64) is located near the portion of the outer edge of the lid (60) between the lid-side air intake opening (61) and the lid-side exhaust opening (62) in the circumferential direction.

[0106] The first pin (95) and the second pin (96) are formed on the substrate (47a) of the base portion (47). The first pin (95) and the second pin (96) protrude forward from the substrate (47a) at one end in the axial direction. The first pin (95) and the second pin (96) are offset by approximately 180 degrees in the circumferential direction. The first pin (95) and the second pin (96) are positioned on the outer edge of the base-side recess (47b). The first pin (95) is positioned approximately 90° in the second rotational direction (R2) from the air intake port (48), and the second pin (96) is positioned approximately 90° in the second rotational direction (R2) from the exhaust port (49).

[0107] As shown in Figure 15(A), the first lid-side projection (63) and the first pin (95) come into contact with each other when the lid (60) is at a first rotation angle (θ1) that fully closes the ventilation opening (VO). Specifically, the side edge of the first lid-side projection (63) on the second rotation direction (R2) side comes into contact with the first pin (95). As a result, the first lid-side projection (63) and the first pin (95) restrict the lid (60) from further rotating in the second rotation direction (R2) when it is at the first rotation angle (θ1). The first lid-side projection (63) and the first pin (95) constitute a first limiting mechanism that restricts the lid (60) that fully closes the ventilation opening (VO) from rotating in the direction that closes the ventilation opening (VO).

[0108] As shown in Figure 15(C), the second lid-side projection (64) and the second pin (96) come into contact with each other when the lid (60) is at the second rotation angle (θ2) in which the opening (CO) is fully open. Specifically, the side edge of the second lid-side projection (64) on the first rotation direction (R1) side comes into contact with the second pin (96). As a result, the second lid-side projection (64) and the second pin (96) restrict the lid (60) at the second rotation angle (θ2) from further rotating in the first rotation direction (R1). The second lid-side projection (64) and the second pin (96) constitute a second limiting mechanism that restricts the lid (60) in which the ventilation opening (VO) is fully open from rotating in the direction that opens the ventilation opening (VO).

[0109] With the above configuration, the lid (60) of this embodiment is configured to allow adjustment of the rotation angle within the range of a first rotation angle (θ1=0°) to a second rotation angle (θ2=90°).

[0110] (4) Refrigerant leak sensor and control unit As shown in Figure 4, the container refrigeration unit (10) includes a refrigerant leak sensor (110) and a control unit (100). The refrigerant leak sensor (110) detects refrigerant leakage from the refrigerant circuit (R). Specifically, when the refrigerant concentration around the refrigerant leak sensor (110) reaches a predetermined value or higher, it outputs a detection signal to the control unit (100). As shown in Figure 2, the refrigerant leak sensor (110) is located in the internal storage space (15). Specifically, for example, the refrigerant leak sensor (110) is located in the internal passage (19) downstream of the internal heat exchanger (29) in the airflow.

[0111] The control unit (100) controls the container refrigeration unit (10). The control unit (100) includes a microprocessor, electrical circuits, and electronic circuits. The microprocessor includes a CPU (Central Processing Unit), memory, communication interfaces, analog input / output, and contact input / output interfaces. The memory stores various programs for the CPU to execute and data used by the programs.

[0112] The control unit (100) controls the mechanical elements of the container refrigeration unit (10). The control unit (100) controls the drive mechanism (70) of the ventilation unit (40). Specifically, the control unit (100) controls the drive mechanism (70) so that the rotation angle of the lid (60) (current rotation angle (θc)) converges to a set target value (target rotation angle (θt)). As shown in Figure 4, this target value may be a value that the user of the container refrigeration unit (10) can arbitrarily set via the operation unit (101). The operation unit (101) consists of, for example, a touch panel, a remote controller, and a DIP switch provided on the container refrigeration unit (10). The operation unit (101) may also be a communication terminal that connects to the container refrigeration unit (10) via a network. The target value does not necessarily have to be set by the user; for example, it may be a value that the control unit (100) automatically determines depending on the operating mode and operating conditions.

[0113] When the refrigerant leak sensor (110) detects a refrigerant leak, the control unit (100) controls the drive mechanism (70) so that the lid (60) is in the closed position.

[0114] (5) Basic operation of ventilation system In the ventilation device (40), the lid (60) performs reciprocating and rotational motion. First, these motions will be explained, mainly with reference to Figures 14 and 15. In the following explanation, "one end in the axial direction" refers to the end of the drive shaft (72) that is closer to the lid (60) in the axial direction, and "the other end in the axial direction" refers to the end of the drive shaft (72) that is further away from the lid (60) in the axial direction.

[0115] (5-1) Reciprocating motion In the reciprocating motion, the axial position of the cam mechanism (80) relative to the rod (73) changes due to contact between the rod (73) and the second transmission part (C2). Consequently, the axial relative position between the cover (60) connected to the cam mechanism (80) and the base part (47) is changed. The reciprocating motion consists of a first reciprocating motion corresponding to the first inclined surface (84) and a second reciprocating motion corresponding to the second inclined surface (85).

[0116] (5-1-1) First reciprocating motion As shown in Figure 14(A), when the rod (73) of the drive mechanism (70) is positioned at the top (P) of the cam mechanism (80), the cam mechanism (80) is positioned furthest to the other end in the axial direction. In this state, the axial distance between the lid (60) and the base (47) is the shortest. As a result, the packing (65) is sandwiched between the lid (60) and the base (47), and the packing (65) is pressed against the base (47) by the lid (60). The position shown in Figure 14(A) is the first position in which the lid (60) compresses the packing (65).

[0117] From the state shown in Figure 14(A), when the motor (71) rotates the drive shaft (72) and then the rod (73) in the first rotational direction (R1), the rod (73) comes into contact with the first inclined surface (84). As the rod (73) moves in the first rotational direction (R1) and away from the top (P), the cam mechanism (80) moves to one end in the axial direction.

[0118] As the rod (73) moves further in the first rotational direction (R1), the rod (73) reaches the first flat surface (86). Further rotation of the rod (73) in the first rotational direction (R1) brings the rod (73) into contact with the first end surface (83a) of the projection plate (83), as shown in Figure 14(B). In this state, the cam mechanism (80) is located furthest to one end in the axial direction. As a result, the axial distance between the lid (60) and the base portion (47) becomes the longest, and the packing (65) moves away from the base portion (47). The position shown in Figure 14(B) corresponds to the second position, where the lid (60) is further from the base portion (47) than the first position. When the lid (60) is in the second position, the compression of the packing (65) by the lid (60) is released.

[0119] From the state shown in Figure 14(B), when the motor (71) rotates the drive shaft (72) and then the rod (73) in the second rotational direction (R2), the rod (73) comes into contact with the first inclined surface (84). As the rod (73) moves in the second rotational direction (R2) and approaches the top (P), the cam mechanism (80) moves to the other end in the axial direction. As shown in Figure 14(A), when the rod (73) reaches the top (P), the packing (65) is compressed by the lid.

[0120] In the first reciprocating motion, the first rotational angle range (θd1) in which the rod (73) and the first inclined surface (84) come into contact is set to 45°. In other words, to move the rod (73) from the position in Figure 14(A) to the position in Figure 14(B), the drive shaft (72) must be rotated in the first rotational direction (R1) by the first rotational angle range (θd1).

[0121] (5-1-2) Second reciprocating motion From the state shown in Figure 14(A), when the motor (71) rotates the drive shaft (72) and then the rod (73) in the second rotational direction (R2), the rod (73) comes into contact with the second inclined surface (85). As the rod (73) moves in the second rotational direction (R2) and away from the top (P), the cam mechanism (80) moves to one end in the axial direction.

[0122] As the rod (73) moves further in the second rotational direction (R2), the rod (73) reaches the second flat surface (87). Further rotation of the rod (73) in the second rotational direction (R2) brings the rod (73) into contact with the second end surface (83b) of the projection plate (83), as shown in Figure 14(C). In this state, the cam mechanism (80) is located furthest to one end in the axial direction. As a result, the axial distance between the lid (60) and the base portion (47) becomes the longest, and the packing (65) moves away from the base portion (47). The position shown in Figure 14(C) corresponds to the second position, where the lid (60) is further from the base portion (47) than in the first position. When the lid (60) is in the second position, the compression of the packing (65) by the lid (60) is released.

[0123] From the state shown in Figure 14(C), when the motor (71) rotates the drive shaft (72) and then the rod (73) in the first rotational direction (R1), the rod (73) comes into contact with the second inclined surface (85). As the rod (73) moves in the first rotational direction (R1) and approaches the top (P), the cam mechanism (80) moves to the other end in the axial direction. As shown in Figure 14(A), when the rod (73) reaches the top (P), the packing (65) is compressed by the lid.

[0124] In the second reciprocating motion, the second rotational angle range (θd2) in which the rod (73) and the second inclined surface (85) come into contact is set to 45°. In other words, to move the rod (73) from the position in Figure 14(A) to the position in Figure 14(C), the drive shaft (72) must be rotated in the second rotational direction (R2) by the second rotational angle range (θd2).

[0125] (5-2) Rotational motion In rotational motion, the rotational force of the rod (73) acts on the projection plate (83), which changes the rotation angle of the cam mechanism (80), and consequently the rotation angle of the lid (60). Rotational motion consists of a first rotational motion in which the lid (60) increases the rotation of the ventilation opening (VO), and a second rotational motion in which the lid (60) decreases the opening of the ventilation opening (VO).

[0126] (5-2-1) First rotational motion When the rod (73) is in the position shown in Figure 14(B), the drive shaft (72) rotates in the first rotational direction (R1), and the rotational force of the rod (73) acts on the cam mechanism (80), causing the lid (60) to perform the first rotational motion. Specifically, as the rod (73) moves further in the first rotational direction (R1) while contacting the first end face (83a) of the projection plate (83), the cam mechanism (80) and then the lid (60) rotate in the first rotational direction (R1). As a result, the lid (60) rotates in the order shown in Figures 15(A), 15(B), and 15(C). Consequently, the area in which the lid-side opening (CO) and the ventilation opening (VO) overlap in the axial direction increases. As a result, the effective opening area of ​​the ventilation opening (VO) increases, and the ventilation volume of the ventilation device (40) increases.

[0127] In Figure 15(A), the position of the lid (60) is the closed position, which completely closes the ventilation opening (VO). In this state, the entire lid-side opening (CO) is blocked by the base portion (47). Specifically, the entire lid-side air supply opening (61) overlaps with the base portion (47) in the axial direction, and the entire lid-side exhaust opening (62) overlaps with the base portion (47) in the axial direction.

[0128] In Figure 15(C), the position of the lid (60) is the open position (more precisely, the fully open position) where the lid (60) fully opens the ventilation opening (VO). In this state, the entire lid-side opening (CO) and the entire ventilation opening (VO) overlap in the axial direction. Specifically, the entire lid-side air supply opening (61) and the entire air supply opening (48) overlap in the axial direction, and the entire lid-side exhaust opening (62) and the entire exhaust opening (49) overlap in the axial direction.

[0129] Furthermore, in this state, the lid-side opening (CO) is surrounded by the protrusions (55) of the edge-forming plate (52) shown in Figure 12. As a result, leakage of air and water between the inside and outside of the lid-side opening (CO) can be suppressed.

[0130] Specifically, the lid-side air intake opening (61) and the packing-side air intake opening (66) are surrounded by the air intake-side protrusion (56) when viewed from the axial direction. As a result, the air intake-side protrusion (56) compresses the outer edge of the packing-side air intake opening (66) of the packing (65), thereby suppressing air and water leakage in this area.

[0131] The lid-side exhaust opening (62) and the packing-side exhaust opening (67) are surrounded by the exhaust-side protrusion (55) when viewed from the axial direction. As a result, the exhaust-side protrusion (55) compresses the outer edge of the packing-side exhaust opening (67) of the packing (65), thereby suppressing air and water leakage in this area.

[0132] The position of the cover (60) in Figure 15(B) is an intermediate position between the closed position and the open position. The cover (60) in the intermediate position opens the ventilation opening (VO) to a predetermined opening area (opening degree).

[0133] (5-2-2) Second rotational motion When the rod (73) is in the position shown in Figure 14(C), the drive shaft (72) rotates in the second rotational direction (R1), and the rotational force of the rod (73) acts on the cam mechanism (80), causing the lid (60) to perform a second rotational motion. Specifically, as the rod (73) moves further in the second rotational direction (R2) while contacting the second end face (83b) of the projection plate (83), the cam mechanism (80) and then the lid (60) rotate in the second rotational direction (R2). As a result, the lid (60) rotates in the order shown in Figures 15(C), 15(B), and 15(A). Consequently, the area in which the lid-side opening (CO) and the ventilation opening (VO) overlap in the axial direction becomes smaller. As a result, the effective opening area of ​​the ventilation opening (VO) decreases, and the ventilation volume of the ventilation device (40) decreases.

[0134] (5-3) Control operation The control operation of the ventilation device (40) will be explained in detail. The control unit (100) controls the rotation angle of the lid (60) within a range from the first rotation angle (θ1=0°) shown in Figure 15(A) to the second rotation angle (θ2=90°) shown in Figure 15(C). The control unit (100) controls the drive mechanism (70) so that the current rotation angle (θc) of the lid (60) becomes the target value (target rotation angle (θt)). At the start of the control operation, the rod (73) is at the top (P), and the lid (60) is in the first position (position in Figure 14(A)) where it compresses the packing (65).

[0135] (5-3-1) Basic Control As shown in Figure 16, in the control operation of the ventilation device (40), in step S11, the control unit (100) determines whether the current rotation angle (θc) has already been set. If the current rotation angle (θc) has not been set in step S11, the process proceeds to initialization control, which will be described in detail later. If the current rotation angle (θc) has been set in step S11, the process proceeds to step S12.

[0136] In step S12, the control unit (100) determines whether the current rotation angle (θc) is equal to the target rotation angle (θt). The target rotation angle (θt) is a predetermined value in the range of 0° to 90°. If the current rotation angle (θc) is equal to the target rotation angle (θt), the process proceeds to step S17. In step S17, the target rotation angle (θt) is set as the current rotation angle (θc). The set current rotation angle (θc) is stored in a memory or other storage unit in the control unit (100). If, in step S12, the current rotation angle (θc) is not equal to the target rotation angle (θt), the process proceeds to step S13.

[0137] If the target rotation angle (θt) in step S13 is greater than the current rotation angle (θc), the drive mechanism (70) performs the first operation in step S14 and the second operation in step S15 in succession.

[0138] In the first operation of step S14, the drive mechanism (70) moves the lid (60) from the first position shown in Figure 14(A) to the second position shown in Figure 14(B). Specifically, the drive mechanism (70) rotates the drive shaft (72) in the first rotational direction (R1) by a first rotational angle range (θd1). This releases or reduces the compressive force on the packing (65) by the lid (60).

[0139] In the second operation of step S15, the drive mechanism (70) rotates the lid (60) to the target rotation angle (θt) while maintaining the lid (60) in the second position. Specifically, the drive mechanism (70) rotates the drive shaft (72) in the first rotation direction (R1) by the difference (θt-θc) between the target rotation angle (θt) and the current rotation angle (θc).

[0140] At this time, the lid (60) is in the second position shown in Figure 14(B), so the frictional force (frictional resistance) acting on the packing (65) can be reduced compared to when the lid (60) is in the first position. As a result, the power required to rotate the lid (60) can be reduced. In addition, wear at the contact point between the packing (65) and the base (47) can be suppressed.

[0141] Next, in step S16, the drive mechanism (70) performs a third operation to move the lid (60) to the first position while maintaining it at the target rotation angle (θt). Specifically, in step S16, the drive mechanism (70) rotates the drive shaft (72) in the second rotation direction (R2) by the first rotation angle range (θd1). As a result, the lid (60) comes closest to the base portion (47) and the packing (65) is compressed.

[0142] In this way, after the lid (60) reaches the target rotation angle (θt), the drive mechanism (70) returns the lid (60) to the first position. This prevents the lid (60) from wobbling due to vibrations or the like. In addition, the sealing performance of the packing (65) is improved, so that air and water do not leak from the gap between the lid (60) and the base (47).

[0143] After step S16, when the process moves to step S17, the target rotation angle (θt) is set as the current rotation angle (θc).

[0144] If the target rotation angle (θt) in step S13 is smaller than the current rotation angle (θc), the drive mechanism (70) performs the first operation in step S18 and the second operation in step S19 in succession.

[0145] In the first operation of step S18, the drive mechanism (70) moves the lid (60) from the first position shown in Figure 14(A) to the second position shown in Figure 14(C). Specifically, the drive mechanism (70) rotates the drive shaft (72) in the second rotational direction (R2) by a second rotational angle range (θd2). This releases or reduces the compressive force on the packing (65) by the lid (60).

[0146] In the second operation of step S19, the drive mechanism (70) rotates the lid (60) to the target rotation angle (θt) while maintaining it in the second position. Specifically, the drive mechanism (70) rotates the drive shaft (72) in the second rotation direction (R2) by the difference (θc-θt) between the current rotation angle (θc) and the target rotation angle (θt).

[0147] At this time, the lid (60) is in the second position shown in Figure 14(C), so the frictional force (frictional resistance) acting on the packing (65) can be reduced compared to when the lid (60) is in the first position. As a result, the power required to rotate the lid (60) can be reduced. In addition, wear at the contact point between the packing (65) and the base (47) can be suppressed.

[0148] Next, in step S20, the drive mechanism (70) performs a third operation to move the lid (60) to the first position while maintaining it at a target rotation angle (θt). Specifically, in step S20, the drive mechanism (70) rotates the drive shaft (72) in the first rotation direction (R1) by a second rotation angle range (θd2). As a result, the lid (60) comes closest to the base portion (47) and the packing (65) is compressed.

[0149] In this way, after the lid (60) reaches the target rotation angle (θt), the drive mechanism (70) returns the lid (60) to the first position. This prevents the lid (60) from wobbling due to vibrations or the like. In addition, the sealing performance of the packing (65) is improved, so that air and water do not leak from the gap between the lid (60) and the base (47).

[0150] After step S20, when the process moves to step S17, the target rotation angle (θt) is set as the current rotation angle (θc).

[0151] (5-3-2) Initialization control During the initial operation of the container refrigeration unit (10), the current rotation angle (θc) may not yet be set in step S17. Therefore, in step S11, if the current rotation angle (θc) is not set, the control unit (100) performs the initialization control shown in Figure 17. The control unit (100) may also perform the initialization control in response to manual input by the user. The control unit (100) may also perform the initialization control in response to a command to turn on or off the power of the container refrigeration unit (10). This may be performed, for example, by manual operation by the user.

[0152] In the initialization control, in step S21, the drive mechanism (70) performs a fourth operation. In the fourth operation, the drive mechanism (70) rotates the drive shaft (72) in the second rotation direction (R2) by a third rotation angle (θ3). The third rotation angle (θ3) is the sum of the first rotation angle range (θd1), the second rotation angle range (θd2), and the second rotation angle (θ2=90°). In this embodiment, the third rotation angle (θ3) is set to 180°, which is the sum of the first rotation angle range (θd1=45°) + the second rotation angle range (θd2=45°) + the second rotation angle (θ2=90°). When the fourth operation is performed, regardless of the current rotation angle (θc) of the lid (60), the rod (73) will be in the position shown in Figure 14(C), and the lid (60) will be in the closed position (first rotation angle) shown in Figure 15(A).

[0153] Next, in step S22, the drive mechanism (70) performs a fifth operation. In the fifth operation, the drive mechanism (70) rotates the drive shaft (72) in the first rotational direction (R1) by a second rotational angle range (θd2). As a result, the rod (73) at the position shown in Figure 14(C) is positioned at the top (P) as shown in Figure 14(A).

[0154] Next, in step S23, the control unit (100) sets the current rotation angle (θc) to the first rotation angle (θ1=0°). Specifically, 0° is stored as the current rotation angle (θc) in the memory unit of the control unit (100).

[0155] As a result, in the subsequent control operation of the ventilation device (40), the current rotation angle (θc) of the lid (60) can be adjusted to the target rotation angle (θt) while the lid (60) is at the first rotation angle (θ1) and first position.

[0156] (5-4) Control Examples Next, an example of the control of the ventilation device (40) will be described. The control unit (100) performs full-open control, full-close control, and opening degree adjustment control.

[0157] (5-4-1) Full throttle control Fully open control is a control that fully opens the ventilation opening (VO). In fully open control, the target rotation angle (θt) is set to the second rotation angle (θ2 = 90°). The drive mechanism (70) first moves the lid (60) to the second position shown in Figure 14(B), and then moves the lid (60) to the open position (fully open position) shown in Figure 15(C) in the second operation.

[0158] Next, the drive mechanism (70) returns the lid (60) to the first position shown in Figure 14(A) through a third operation. As a result, the lid (60), which is in the fully open position, is tightly attached to the base (47) via the packing (65), which suppresses the lid (60) from wobbling and allows the lid (60) to be stably supported. In addition, the sealing performance of the packing (65) is improved, which suppresses the leakage of air and water in the gap between the packing (65) and the base (47).

[0159] (5-4-2) Fully closed control The fully closed control is a control that completely closes the ventilation opening (VO). In fully closed control, the target rotation angle (θt) is set to the first rotation angle (θ2 = 0°). The drive mechanism (70) first moves the lid (60) to the second position shown in Figure 14(C), and then moves the lid (60) to the closed position shown in Figure 15(A) in the second operation.

[0160] Next, the drive mechanism (70) returns the lid (60) to the first position shown in Figure 14(A) by a third operation. As a result, the lid (60), now in the closed position, adheres tightly to the base (47) via the packing (65), preventing the lid (60) from wobbling and allowing it to be stably supported. In addition, the sealing performance of the packing (65) is improved, which suppresses the leakage of air and water in the gap between the packing (65) and the base (47). In particular, in fully closed control, ventilation of the internal space (3) of the container (1) is not performed, so the airtightness of the container (1) is important. This is because if air from the outside space (5) enters the container (1), the quality of the stored goods may be impaired or the cooling load of the container refrigeration unit (10) may increase. Therefore, by improving the sealing performance of the packing (65) in this way, the airtightness of the container (1) can be ensured, and such problems can be avoided.

[0161] (5-4-3) Opening degree adjustment control Opening degree adjustment control is a control that adjusts the opening area of ​​the ventilation opening (VO) to a predetermined opening degree. In opening degree adjustment control, the target rotation angle (θt) of the cover (60) is set to a predetermined rotation angle in the range of, for example, 5° to 85°. The drive mechanism (70) first moves the cover (60) to the second position shown in Figures 14(B) and 14(C), and then moves the cover (60) to a predetermined intermediate position shown in Figure 15(B) in the second operation.

[0162] Next, the drive mechanism (70) returns the lid (60) to the first position shown in Figure 14(A) through a third operation. As a result, the lid (60), now in the intermediate position, is tightly attached to the base (47) via the packing (65), which suppresses the lid (60) from wobbling and allows for stable support of the lid (60). In addition, the sealing performance of the packing (65) is improved, which suppresses the leakage of air and water in the gap between the packing (65) and the base (47). In opening adjustment control, it is also possible to suppress the inability to obtain the target ventilation volume due to air leakage.

[0163] (6) Effects of the Embodiment If the ventilation device has a structure that allows the lid to be opened and closed manually, the seal between the lid and the base can be ensured by firmly fastening the lid toward the base. In contrast, in this embodiment, the ventilation opening (VO) is opened and closed automatically by the drive mechanism (70), so the seal between the lid and the base cannot be ensured manually.

[0164] In contrast, the ventilation device (40) of this embodiment includes a spring (77) as a pressing part that presses the lid (60) toward the base part (47). The spring (77) presses the lid (60) in the closed position toward the base part (47), so that the packing (65) between the lid (60) and the base part (47) can be sufficiently compressed. As a result, while the ventilation opening (VO) is opened and closed automatically, leakage of air and water between the lid (60) and the base part (47) can be suppressed.

[0165] By suppressing air leakage, the airtightness of the container (1) can be improved. In particular, with fully closed control, sufficient airtightness of the container (1) can be ensured, improving the reliability of the container refrigeration unit (10). With fully open control or opening degree adjustment control, it is possible to prevent the desired ventilation volume from not being achieved. By suppressing water leakage, it is possible to prevent equipment such as the motor (71) of the ventilation unit (40) from getting wet.

[0166] In this embodiment, the spring (77) is provided on the drive mechanism (70) as shown in Figure 8. Therefore, the spring (77) can be installed inside the ventilation device (40) while suppressing interference between the spring (77) and the lid (60) or the base (47). Consequently, the ventilation device (40) can be made smaller.

[0167] Furthermore, since the spring (77) in this embodiment is provided along the drive shaft (72), interference between the spring (77) and other parts can be suppressed.

[0168] Furthermore, in this embodiment, the spring (77) is helical, and the drive shaft (72) is inserted inside the spring (77). This suppresses interference between the spring (77) and other parts. Since the spring (77) and the drive shaft (72) are arranged coaxially, interference between the spring (77) and other parts can also be suppressed when the drive shaft (72) rotates.

[0169] In this embodiment, as shown in Figures 12 and 13, a protrusion (55) is provided between the lid (60) and the base portion (47). Since the protrusion (55) protrudes toward the packing (65), the packing (65) and the tip of the protrusion (55) can be brought into substantially line contact. This improves the sealing performance of the portion of the packing (65) that is in contact with the protrusion (55).

[0170] In this embodiment, the protrusion (55) contacts the outer edges of the packing side air supply opening (66) and packing side exhaust opening (67), which are openings in the packing (65) through which air flows. Therefore, leakage of air or water from the outer edges of these openings in the packing (65) can be suppressed.

[0171] In this embodiment, the spring (77) presses the central part of the lid (60) toward the base part (47). This prevents the pressing force of the packing (65) by the spring (77) from becoming uneven in the circumferential direction. On the other hand, in this case, the pressing force of the packing (65) by the spring (77) decreases from the center toward the outer edge. In contrast, in this embodiment, the protruding height of the convex part (55) increases from the central part of the lid (60) toward the outer edge of the lid (60). Therefore, the compressive force of the packing (65) can be made uniform in the radial direction, thereby improving the sealing performance of the packing (65).

[0172] In this embodiment, the drive mechanism (70) moves the lid (60) in a first direction to adjust the distance between the lid (60) and the base portion (47). By adjusting this distance, the compressive force of the packing (65) can be adjusted.

[0173] In this embodiment, a lid-side opening (CO) is formed in the lid (60). The drive mechanism (70) rotates the lid (60) to adjust the overlapping area between the lid-side opening (CO) and the ventilation opening (VO). This allows adjustment of the opening degree of the ventilation opening (VO) and, consequently, the amount of ventilation. By widening the gap between the lid (60) and the base (47) when rotating the lid (60), the frictional force acting on the packing (65) can be reduced. As a result, the power of the motor (71) can be reduced, and power consumption can be suppressed. The load torque of the motor (71) can be reduced, allowing the motor (71) to be made smaller. Wear of the packing (65) can be suppressed, so the frequency of replacing the packing (65) can be reduced.

[0174] The drive mechanism (70) of this embodiment includes a motor (71) which is a drive source and a drive shaft (72) which is rotationally driven by the motor (71). The drive mechanism (70) is configured to perform rotational motion, which rotates the lid (60) in accordance with the rotation of the drive shaft (72), and reciprocating motion, which moves the lid (60) back and forth in the axial direction, which is a first direction, in accordance with the rotational motion of the drive shaft (72). This allows the lid (60) to perform both rotational and reciprocating motion using a single motor (71) and a single drive shaft (72).

[0175] The drive mechanism (70) of this embodiment includes a rod (73) connected to a drive shaft (72) and a cam mechanism (80) connected to a lid (60) and having a contact surface (82) in which the rod (73) makes contact. The contact surface (82) includes a first transmission section (C1) that transmits the rotational force of the drive shaft (72) to the lid (60) to cause the lid (60) to rotate, and a second transmission section (C2) that transmits the rotational force of the drive shaft (72) to the lid (60) to cause it to reciprocate. As a result, the rotational force of the drive shaft (72) can be used as reciprocating motion and rotational motion of the lid (60).

[0176] The first transmission unit (C1) of this embodiment has a first end face (83a) formed along the axial direction and contacted by a rod (73) moving in a first rotational direction (R1), and a second end face (83b) formed along the axial direction and contacted by a rod (73) moving in a second rotational direction (R2). The second transmission unit (C2) has a first inclined surface (84) that approaches the other end side in the axial direction (opposite side of the lid (60)) as it approaches the first end face (83a), and a second inclined surface (85) that approaches the other end side in the axial direction as it approaches the second end face (83b). This makes it possible to adjust the distance between the lid (60) and the base unit (47) or to rotate the lid (60) in the first rotational direction (R1) while rotating the drive shaft (72) in the first rotational direction (R1). By rotating the drive shaft (72) in the second rotational direction (R2), the distance between the lid (60) and the base (47) can be adjusted, or the lid (60) can be rotated in the second rotational direction (R2).

[0177] The ventilation device (40) of this embodiment includes a bearing (73b) as a low-friction part that reduces the frictional force between the rod (73) and the contact surface (82) of the cam mechanism (80). This reduces the frictional force between the rod (73) and the bearing (73b), thereby suppressing wear of the rod (73) and the cam mechanism (80). As a result, it is possible to suppress instability in the reciprocating motion and rotational motion of the lid (60) caused by wear of these parts.

[0178] In this embodiment, the contact surface (82) of the cam mechanism (80) has a first flat surface (86) formed between the first end surface (83a) and the first inclined surface (84), along a plane perpendicular to the axial direction. Therefore, the rod (73) moving from the first inclined surface (84) to the first end surface (83a) passes through the first flat surface (86) before contacting the first end surface (83a). As a result, simultaneous contact of the rod (73) with both the first inclined surface (84) and the first flat surface (86) can be suppressed, and a smooth transition from the first reciprocating motion to the first rotational motion can be achieved.

[0179] Similarly, in this embodiment, a second flat surface (87) is formed on the contact surface (82) of the cam mechanism (80) between the second end surface (83b) and the second inclined surface (85), along a plane perpendicular to the axial direction. Therefore, the rod (73) moving from the second inclined surface (85) to the second end surface (83b) passes through the second flat surface (87) before contacting the second end surface (83b). As a result, simultaneous contact of the rod (73) with both the second inclined surface (85) and the second flat surface (87) can be suppressed, and a smooth transition from the second reciprocating motion to the second rotational motion can be achieved.

[0180] In this embodiment, three or more rods (73) are connected to the drive shaft (72). This allows the stress between the rods (73) and the contact surface (82) to be distributed, enabling stable driving of the cam mechanism (80). Furthermore, wear between the rods (73) and the contact surface (82) can be suppressed.

[0181] The drive mechanism (70) of this embodiment is configured to perform a first operation to move the lid (60), which compresses the packing (65), from a first position to a second position further away from the base (47) than the first position, and a second operation after the first operation to rotate the lid (60) to a predetermined rotation angle while maintaining it in the second position. This operation reduces the frictional force on the packing (65) while rotating the lid (60), thereby reducing the power of the motor (71) and lowering power consumption. The load torque of the motor (71) can be reduced, allowing the motor (71) to be made smaller. Wear of the packing (65) can be suppressed, reducing the frequency of packing (65) replacement.

[0182] The drive mechanism (70) of this embodiment is configured to perform a third operation after the second operation, which moves the lid (60) to the first position while maintaining it at a predetermined rotation angle. As a result, after the lid (60) has been adjusted to the predetermined angle, the third operation brings the lid (60) closer to the base (47). Therefore, it is possible to suppress the lid (60) from wobbling due to vibration or the like. In addition, since the packing (65) is compressed by the third operation, it is possible to suppress the leakage of air or water.

[0183] In this embodiment, the predetermined rotation angle includes a first rotation angle (θ1) in which the entire ventilation opening (VO) is closed by the lid (60). In other words, the drive mechanism (70) sets the lid (60) to the closed position and then sets the lid (60) to the first position. When the lid (60) is in the closed position, it is necessary to ensure the airtightness of the container (1). In contrast, by setting the lid (60) to the first position, the packing (65) is compressed, so that the airtightness of the container (1) can be sufficiently ensured.

[0184] This embodiment includes a control unit (100) that controls the drive mechanism (70) so that the rotation angle of the lid (60) reaches a set target value. This allows for arbitrary adjustment of the opening area of ​​the ventilation port (VO) and, furthermore, the ventilation volume.

[0185] In this embodiment, the control unit (100) controls the drive mechanism (70) so that the lid (60) is in the closed position when the refrigerant leak sensor (110) detects a refrigerant leak. This prevents the refrigerant from leaking from the inside of the container (1) to the outside when the refrigerant leaks from the refrigerant circuit (R).

[0186] (7) Variant The above embodiment may also have the following modified configuration. The following will explain the differences from the above embodiment.

[0187] (7-1) Variation 1 In the ventilation device (40) of Modification 1 shown in Figures 18 to 20, the lid (60) does not rotate but only reciprocates. The lid (60) does not have a lid-side opening (CO). The packing (65) does not have a packing-side air supply opening (66) or a packing-side exhaust opening (67). When the lid (60) separates from the base (47), a gap is formed between the outer edge of the lid (60) and the base (47). In Modification 1, this gap constitutes a ventilation opening (VO).

[0188] The drive mechanism (70) rotates the drive shaft (72) in the above embodiment. The rod (73) comes into contact with the first inclined surface (84) and the second inclined surface (85), which are the second transmission part (C2), causing the cam mechanism (80) to reciprocate in the axial direction. As shown in Figure 20(A), when the lid (60) is in the first position, the packing (65) is sandwiched between the lid (60) and the base part (47), and the packing (65) is compressed. In this state, the ventilation opening (VO) between the lid (60) and the base part (47) is closed. In modified example 1, the ventilation opening (VO) is fully closed when the lid (60) is in the first position (closed position). In this state, the gap between the lid (60) and the base part (47) is sealed by the packing (65), so that the airtightness of the container (1) can be sufficiently ensured.

[0189] As shown in Figure 20(B), when the lid (60) is in the second position, the lid (60) separates from the base (47), and a ventilation opening (VO) is formed between the lid (60) and the base (47). In the modified example 1, the ventilation opening (VO) is open when the lid (60) is in the second position (open position). In this state, the compression of the packing (65) by the lid (60) is released.

[0190] In the modified example 1, the drive mechanism (70) moves the lid (60) to adjust the distance between the lid (60) and the base (47). When the distance between the lid (60) and the base (47) changes, the opening area of ​​the ventilation opening (VO) also changes. Therefore, the ventilation volume can be adjusted by adjusting the axial position of the lid (60).

[0191] As shown in Figures 18 and 19, the ventilation device (40) is provided with a spring (77) similar to that in the embodiment, as well as a first auxiliary spring (121) and a second auxiliary spring (122) as pressing parts. The first auxiliary spring (121) and the second auxiliary spring (122) are located near the outer circumference of the lid (60). The first auxiliary spring (121) and the second auxiliary spring (122) are located opposite each other across the axis (X). When viewed from the axial direction, the first auxiliary spring (121) and the second auxiliary spring (122) are located between the air intake port (48) and the exhaust port (49), respectively.

[0192] The ventilation device (40) is provided with a first column member (123), a second column member (124), a first connecting member (125), and a second connecting member (126).

[0193] The first column member (123) and the second column member (124) are fixed to the outer circumference portion of the base portion (47). The first column member (123) and the second column member (124) extend along the axis (X). A first flange portion (123a) is formed at one axial end (front end) of the first column member (123), and a second flange portion (124a) is formed at one axial end (front end) of the second column member (124).

[0194] The first connecting member (125) and the second connecting member (126) are formed in a cylindrical shape with an axis in the front-rear direction. The first connecting member (125) and the second connecting member (126) are fixed to the outer circumference portion of the back surface (rear face) of the lid (60). A first support plate (125a) is formed behind the first connecting member (125), and a second support plate (126a) is formed behind the second connecting member (126).

[0195] The first auxiliary spring (121) is sandwiched between the first flange (123a) and the first support plate (125a). The first auxiliary spring (121) is formed in a spiral shape. The first column member (123) is inserted through the inside of the first auxiliary spring (121). The second auxiliary spring (122) is sandwiched between the second flange (124a) and the second support plate (126a). The second auxiliary spring (122) is formed in a spiral shape. The second column member (124) is inserted through the inside of the second auxiliary spring (122). The biasing force of the first auxiliary spring (121) acts to move the first support plate (125a) backward. The biasing force of the second auxiliary spring (122) acts to move the second support plate (126a) backward. This biasing force presses the lid (60) that connects to the first connecting member (125) and the second connecting member (126) toward the base portion (47). When the lid (60) is pressed toward the base portion (47), the packing (65) between the lid (60) and the base portion (47) is compressed in the thickness direction. This improves the sealing performance of the packing (65).

[0196] (8) Other embodiments The ventilation device (40) may also be applied to a container (1) that does not have a refrigeration function.

[0197] Container (1) does not have to be for sea transport; it may also be for land transport, such as being transported by vehicles like trailers or by rail.

[0198] The container refrigeration unit (10) may have an air composition adjustment device that adjusts the composition of oxygen, carbon dioxide, nitrogen, etc., of the air in the internal space (3). The air composition adjustment device adjusts the air in the internal space (3) using, for example, PSA (Pressure Swing Adsorption) or a gas separation membrane.

[0199] The ventilation device (40) may have only the function of supplying air by transporting air from the outside space (5) to the inside space (3), and exhaust may be performed naturally from the exhaust port. The ventilation device (40) may have only the function of exhausting air by transporting air from the inside space (3) to the outside space (5), and supplying air may be performed naturally from the air intake port.

[0200] In the above-described embodiment, the ventilation device (40) adjusts the opening of the ventilation opening (VO) by rotating the lid (60). However, the ventilation device (40) may also adjust the opening of the ventilation opening (VO) by adjusting the distance between the lid (60) and the base (47), similar to the first modified example.

[0201] The base portion (47) may be formed integrally with the casing body (12) of the container refrigeration unit (10).

[0202] The sealing member may be made of an elastic material other than a packing.

[0203] The edge forming member (50) may be formed integrally with the base portion (47).

[0204] An edge-forming member (50) may be provided between the lid (60) and the packing (65).

[0205] In modified example 1, the packing (65) may be fixed to the base portion (47). In this case, an opening that serves as a ventilation opening is formed in the packing (65).

[0206] The drive source for the drive mechanism (70) is not limited to a motor (71), but can be any configuration that can rotate or reciprocate the lid (60).

[0207] The drive mechanism (70) may have separately a drive source for rotating the lid (60) and a drive source for reciprocating the lid (60).

[0208] The first direction does not have to be axial; it may be any other direction that allows adjustment of the distance between the lid (60) and the base (47).

[0209] The spring (77) may be a leaf spring or made of an elastic material. The drive shaft (72) does not need to be inserted through the spring (77). The spring (77) may extend axially so as to be adjacent to the drive shaft (72).

[0210] The pressing mechanism does not have to be a spring. The pressing mechanism uses, for example, hydraulic pressure or refrigerant pressure to press the lid (60) toward the base (47).

[0211] The low-friction portion may be a liquid lubricant such as grease applied between the rod (73) and the contact surface (82). The low-friction portion may also be a low-friction material formed on at least the surface of the rod (73) or the contact surface (82). The low-friction material is composed of a resin material such as POM (polyacetal) or PTFE (polytetrafluoroethylene).

[0212] The lid (60) in the second position only needs to be further from the base (47) than the lid (60) in the first position, and the packing (65) may be slightly compressed.

[0213] While embodiments and modifications have been described above, it will be understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the embodiments, modifications, and other embodiments described above may be combined or substituted as appropriate, as long as they do not impair the functions covered by this disclosure.

[0214] The designations "1st," "2nd," "3rd," etc., mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms. [Industrial applicability]

[0215] As described above, this disclosure is useful for ventilation systems. [Explanation of symbols]

[0216] 2 Container body 40 Ventilation system 47 Base section 55 Convex part 60 Lid 65 Packing (sealing material) 70 Drive mechanism 71 Motor (Drive Source) 72 Drive shaft 73 Rods 73b Bearing (low friction part) 77 Springs 77,121,122 Pressing part 80 Cam mechanism 82 Contact surface 100 Control Unit 110 Refrigerant leak sensor C1 First Transmission Unit C2 Second Transmission Section CO Lid side opening (opening) VO vent

Claims

1. A base section (47) having a ventilation opening (VO) for connecting the inside and outside of the container body (2), A cover (60) for opening and closing the aforementioned ventilation opening (VO), A drive mechanism (70) that displaces the lid (60) between an open position and a closed position, A sealing member (65) is formed between the base portion (47) and the lid (60) at a position surrounding the ventilation opening (VO), Pressing parts (77, 121, 122) that press the lid (60) toward the base part (47) Equipped with, The pressing portion (77, 121, 122) has springs (77, 121, 122) that press the lid (60) toward the base portion (47). Ventilation system.

2. The drive mechanism (70) comprises a drive source (71) and a drive shaft (72) driven by the drive source (71), The springs (77, 121, 122) are provided along the drive shaft (72) and include a first spring (77) that presses the central part of the lid (60) toward the base part (47). The ventilation device according to claim 1.

3. The first spring (77) is spiral in shape, The drive shaft (72) is inserted inside the first spring (77). The ventilation device according to claim 2.

4. The springs (77, 121, 122) include auxiliary springs (121, 122) located near the outer circumference of the lid (60) that press the lid (60) toward the base portion (47). The ventilation device according to claim 1.

5. The auxiliary springs (121, 122) include a first auxiliary spring (121) and a second auxiliary spring (122) positioned opposite each other across the axis (X) of the drive shaft (72). The ventilation device according to claim 4.

6. The base portion (47) is provided with an air intake port (48) and an exhaust port (49) formed around the axis (X) of the drive shaft (72), The air intake port (48) and the exhaust port (49) are located opposite each other across the axis (X) of the drive shaft (72), The first auxiliary spring (121) and the second auxiliary spring (122) are located, when viewed from the axial direction, between the air intake port (48) and the exhaust port (49), respectively. The ventilation device according to claim 5.

7. A first column member (123) and a second column member (124) are fixed to the outer circumference portion of the base portion (47), corresponding to the first auxiliary spring (121) and the second auxiliary spring (122), respectively, extending in the axial direction of the drive shaft (72). The ventilation device according to claim 5.

8. A first connecting member (125) and a second connecting member (126) are fixed to the outer peripheral portion of the surface of the lid (60) on the base portion (47) side. The first connecting member (125) and the second connecting member (126) are formed with a first support plate (125a) and a second support plate (126a), respectively. The ventilation device according to claim 7.

9. A first flange portion (123a) and a second flange portion (124a) are formed at one end in the axial direction of the first column member (123) and the second column member (124), respectively. The first auxiliary spring (121) is sandwiched between the first flange portion (123a) and the first support plate (125a), The second auxiliary spring (122) is sandwiched between the second flange (124a) and the second support plate (126a). The ventilation device according to claim 8.

10. The first auxiliary spring (121) and the second auxiliary spring (122) are helical in shape, The first column member (123) and the second column member (124) are inserted into the first auxiliary spring (121) and the second auxiliary spring (122), respectively. The ventilation device according to claim 9.

11. The drive mechanism (70) moves the lid (60) in the axial direction of the drive shaft (72) so as to adjust the distance between the outer edge of the lid (60) and the base portion (47), The opening area of ​​the ventilation opening (VO) changes according to the interval. A ventilation device according to any one of claims 1 to 10.

12. The drive mechanism (70) moves the lid (60) between a first position in which the seal member (65) is compressed and a second position further away from the base portion (47) than the first position. The ventilation device according to claim 11.

13. A refrigerant leak sensor (110) for detecting refrigerant leakage, The system includes a control unit (100) that controls the drive mechanism (70) so that the lid (60) is in the closed position when the refrigerant leak sensor (110) detects a refrigerant leak. A ventilation device according to any one of claims 1 to 10.

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