Vehicle exterior unit, transport refrigeration machine, and transport refrigeration vehicle

Abstract

This vehicle exterior unit comprises: a casing that is mounted on the top surface of a vehicle and has a rectangular shape in which one among the travel direction and the width direction of the vehicle is the longitudinal direction; and a compressor that is disposed inside the casing and rotationally driven about an axis extending in the other among the travel direction and the width direction. With this configuration, it is possible to provide a transport refrigeration machine and a transport refrigeration vehicle that can further stably resist vibration during travel.

Description

External unit, transport refrigeration machine, and transport refrigeration vehicle

[0001] This application claims priority to Japanese Patent Application No. 2024-089084, filed May 31, 2024, the contents of which are incorporated herein by reference.

[0002] Vehicles equipped with refrigeration machines equipped with refrigeration cycle devices are widely used to transport cargo at low temperatures. The refrigeration cycle devices mainly include a compressor, a condenser, an expansion valve, and an evaporator. When installed in a vehicle, the evaporator is typically disposed in a refrigeration compartment as an on-board unit, while the compressor, condenser, and expansion valve are typically mounted on the exterior of the vehicle as external units.

[0003] Examples of such vehicles include trailer-type vehicles, which tow a container mounted on a chassis using a tractor head, and van-type vehicles, which have a freezer compartment and a driver's cab integrated into one unit. In trailer-type vehicles, the external unit is attached to the front wall of the container. On the other hand, in van-type vehicles, the external unit is located on the top surface of the vehicle. For this reason, in van-type vehicles, vibrations generated in the vehicle itself during driving tend to be easily transmitted to the external unit. In order to absorb and attenuate vibrations, it is desirable that the compressor included in the external unit be attached to the casing via vibration-isolating rubber, as in the device described in Patent Document 1 below. In particular, in order to reduce the height, it is possible to install a horizontally mounted compressor and provide vibration-isolating measures.

[0004] Japanese Patent Application Laid-Open No. 2019-056355

[0005] However, in the case of the van-type vehicle, in addition to vibrations in the vertical direction, vibrations in the direction of travel when starting and stopping, and vibrations in the width direction when going around curves are also applied to the external unit, so there is a risk that simply providing vibration-isolating rubber will not be enough to resist vibrations in each direction.

[0006] The present disclosure provides an external unit, a transport refrigeration machine, and a transport refrigeration vehicle that are more stably able to withstand vibrations during driving.

[0007] The external unit of the present disclosure comprises a rectangular casing mounted on the top surface of the vehicle and having its longitudinal direction in either the direction of travel or the width direction of the vehicle, and a compressor disposed inside the casing and driven to rotate around an axis extending in the other of the direction of travel or the width direction.

[0008] The transport refrigeration machine according to the present disclosure includes the above-described exterior unit, and an evaporator, a condenser, and an expansion valve that, together with the compressor, constitute a refrigeration cycle device.

[0009] A transport refrigeration vehicle according to the present disclosure includes the transport refrigeration machine described above and a vehicle body on which the transport refrigeration machine is mounted.

[0010] According to the present disclosure, it is possible to provide an external unit, a transport refrigeration machine, and a transport refrigeration vehicle that can more stably withstand vibrations during driving.

[0011] FIG. 1 is a schematic diagram showing the configuration of a transport refrigeration vehicle according to an embodiment of the present disclosure; FIG. 2 is a circuit diagram of a refrigeration cycle device according to an embodiment of the present disclosure; FIG. 3 is a perspective plan view showing the configuration of an exterior unit according to an embodiment of the present disclosure; FIG. 4 is a perspective view showing the configuration of an exterior unit according to an embodiment of the present disclosure; FIG. 5 is a longitudinal cross-sectional view showing the configurations of a first vibration-isolating rubber and a second vibration-isolating rubber according to an embodiment of the present disclosure; FIG. 6 is a perspective view showing a modified example of the exterior unit according to an embodiment of the present disclosure.

[0012] Hereinafter, an external unit 3, a transport refrigeration machine 2, and a transport refrigeration vehicle 1 (simply referred to as a vehicle 10) according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 5 .

[0013] (Vehicle Configuration) As shown in FIG. 1 , the vehicle 10 includes a vehicle body 11 and a transport refrigeration machine 2. The vehicle body 11 includes a body 12, a chassis (not shown), and a plurality of wheels 13. The body 12 includes a driver's cab 14 and a freezer compartment 15. The driver's cab 14 is located at the front of the vehicle 10 in the traveling direction, and the freezer compartment 15 is provided integrally at the rear of the driver's cab 14. In other words, the vehicle 10 is a so-called van type. An engine, a transmission, and the like are mounted on the chassis. The engine drives the wheels 13 to rotate and generates electricity to operate the transport refrigeration machine 2. The transport refrigeration machine 2 may also be powered by a dedicated battery. Furthermore, an electric motor for driving the vehicle may be provided instead of an engine.

[0014] (Configuration of transport refrigeration machine) The transport refrigeration machine 2 has a refrigeration cycle device 20. As shown in Fig. 2 , the refrigeration cycle device 20 has a compressor 21, a condenser 22, an expansion valve 23, an evaporator 24, a first fan 25, a second fan 26, a receiver 27a, an accumulator 27b, an oil separator 28, and a circulation line 29.

[0015] The circulation line 29 is filled with refrigerant. The compressor 21, condenser 22, expansion valve 23, and evaporator 24 are arranged on the circulation line 29 in this order. The compressor 21 compresses the refrigerant and discharges high-temperature, high-pressure refrigerant. The condenser 22 is, for example, a multi-flow or tube-and-fin heat exchanger. In the condenser 22, the refrigerant flowing in from the compressor 21 exchanges heat with the outside air. This reduces the temperature of the refrigerant. Furthermore, this low-temperature refrigerant passes through the expansion valve 23, thereby reducing the pressure and temperature of the refrigerant. The evaporator 24 is a heat exchanger similar to the condenser 22. The evaporator 24 is arranged in the freezing chamber 15 as part of the indoor unit 4, which will be described later. In the evaporator 24, the refrigerant flowing in from the expansion valve 23 exchanges heat with the air in the freezing chamber 15. As a result, the refrigerant absorbs heat from the air and is heated, while the air in the freezing chamber 15 is cooled.

[0016] The first fan 25 is a blower provided in addition to the condenser 22. Driving the first fan 25 promotes efficient supply of outside air to the condenser 22. The second fan 26 is a blower provided in addition to the evaporator 24. Driving the second fan 26 promotes supply of air from the freezing compartment 15 to the evaporator 24. The accumulator 27b and the receiver 27a are provided to separate the refrigerant into gas and liquid. The accumulator 27b is provided between the evaporator 24 and the compressor 21, and the receiver 27a is provided between the condenser 22 and the expansion valve 23. The oil separator 28 is provided to separate lubricating oil contained in the refrigerant and return it to the compressor 21. The oil separator 28 is provided between the compressor 21 and the condenser 22.

[0017] (Configuration of Exterior Unit) Of the components of the refrigeration cycle device 20 described above, the compressor 21, the condenser 22, the expansion valve 23, the accumulator 27b, and the oil separator 28 are arranged on the top surface 16 of the vehicle 10 as the exterior unit 3 (see FIG. 1). On the other hand, the evaporator 24 is housed in an interior unit 4 provided in the freezer compartment 15. As shown in FIG. 3, the exterior unit 3 has the above-described components, an electrical box 50 (a first electrical box 51 and a second electrical box 52), a casing 31, a first vibration-isolating rubber 32, and a second vibration-isolating rubber 33.

[0018] The casing 31 has a rectangular parallelepiped shape with a top surface, a bottom surface 60, and four side surfaces. The casing 31 is disposed so that the bottom surface 60 faces the top surface 16 of the vehicle body 11. The longitudinal direction of the casing 31 coincides with, for example, the width direction A of the vehicle 10. Of the four side surfaces of the casing 31, design panels (not shown) are attached to three surfaces except for the surface facing rearward in the traveling direction B of the vehicle 10. Therefore, when mounting the exterior unit 3 on the vehicle 10, the installation direction can be visually confirmed and determined based on the shape of the design panel, etc.

[0019] As shown in FIG. 4 , first vibration-damping rubbers 32 are provided between the outer bottom surface 61 of the casing 31 and the top surface 16 of the vehicle body 11. The outer bottom surface 61 is the surface of the bottom surface 60 of the casing 31 facing outward. One first vibration-damping rubber 32 is provided at each of the four corners of the outer bottom surface 61 of the casing 31. As shown in FIG. 5 , each first vibration-damping rubber 32 has a pair of plate members 71, a pair of connecting portions 72, and a rubber main body 73. The plate members 71 are provided on the casing 31 side and the top surface 16 side, respectively. The rubber main body 73 is provided between these plate members 71. As an example, the rubber main body 73 has a truncated cone shape whose diameter gradually increases from top to bottom. The casing 31 or the top surface 16 is sandwiched between the rubber main body 73 and the plate member 71. The connecting portions 72 are rod-shaped and extend upward and downward from the plate member 71. That is, holes for inserting the connecting portions 72 are formed in the casing 31 and the top surface 16. The connecting portions 72 do not penetrate the rubber main body 73. Therefore, the interior of the rubber main body 73 is solid. The rubber main body 73 is integrally formed from an elastic resin material such as butadiene rubber.

[0020] The condenser 22 curves and extends from the front surface of the casing 31 to one side surface. Specifically, the condenser 22 has a first portion 22a located on the front side and a second portion 22b located on the side surface. The first portion 22a and the second portion 22b are integrally connected, allowing refrigerant to freely move between them. An oil separator 28 is disposed behind the second portion 22b. The compressor 21, the accumulator 27b, and a first electrical box 51 are disposed inside the first portion 22a and the second portion 22b. The second electrical box 52 is disposed along the side surface opposite the side where the second portion 22b is located. The first electrical box 51 and the second electrical box 52 house control circuits, power supply circuits, and cables for driving the transport refrigeration machine 2.

[0021] The compressor 21 is fixed in a horizontal position on the inner bottom surface 62 of the casing 31 via a stay (not shown) and second vibration-isolating rubber members 33. The inner bottom surface 62 is the inward-facing surface of the bottom surface 60 of the casing 31. The compressor 21 is preferably disposed in the center of the inner bottom surface 62 in the width direction A. The structure of the second vibration-isolating rubber members 33 is similar to that of the first vibration-isolating rubber members 32 described above. Four second vibration-isolating rubber members 33 are provided to support the compressor 21 at four corners. More specifically, one second vibration-isolating rubber member 33 is provided for each of four stays (not shown) extending from the compressor 21. The compressor 21 is, for example, a sealed rotary compressor, and is capable of compressing a refrigerant by rotating a shaft about an axis X. As shown in FIG. 4 , the direction in which the axis X of the compressor 21 extends, i.e., the longitudinal direction, coincides with the traveling direction B of the vehicle 10. Therefore, the longitudinal direction of the casing 31 and the longitudinal direction of the compressor 21 are perpendicular to each other. Note that "perpendicular" here refers to a substantially perpendicular state, and slight errors are allowed. Furthermore, the four second vibration-damping rubbers 33 that support the compressor 21 are located inside an imaginary rectangle R formed by the four first vibration-damping rubbers 32 (see FIG. 3). Note that "rectangle" here refers to any shape with four corners, such as a square, a rectangle, a parallelogram, a trapezoid, etc. Furthermore, the hardness of the rubber body 73 of the second vibration-damping rubber 33 is set higher than the hardness of the rubber body 73 of the first vibration-damping rubber 32.

[0022] (Operation and Effect) As described above, in a van-type vehicle 10, the external unit 3 is generally disposed on the top surface 16 of the vehicle body 11. For this reason, in a van-type vehicle 10, vibrations generated in the vehicle 10 itself during driving tend to be easily transmitted to the external unit 3. However, in a van-type vehicle 10, in addition to vibrations in the height direction, vibrations in the traveling direction B when starting / stopping and vibrations in the width direction A when going around a curve are also applied to the external unit 3. For this reason, simply interposing vibration-damping rubber between the external unit 3 and the vehicle body 11 may not be sufficient to resist vibrations in each direction. To solve this problem, the present embodiment employs the above-described configurations.

[0023] According to the above configuration, the longitudinal direction of the compressor 21, which is the main heavy object, is different from the longitudinal direction of the casing 31. Specifically, when the longitudinal direction of the compressor 21 is the direction of travel B of the vehicle 10, the longitudinal direction of the casing 31 is the width direction A, which is perpendicular to the direction of travel B. This reduces the possibility of vibrations occurring due to road irregularities or the like while the vehicle 10 is traveling, being transmitted to the compressor 21. Conversely, when the longitudinal directions of the compressor 21 and the casing 31 are aligned, vibrations occurring along the longitudinal direction may be superimposed on each other, resulting in the vibrations potentially diverging. This is similar to, for example, the phenomenon where a round bar placed on a gently inclined surface easily rolls due to gravity if its longitudinal direction is aligned with the inclination direction of the inclined surface. In contrast, if the longitudinal direction of the round bar is aligned perpendicular to the inclination direction of the inclined surface, the round bar can resist gravity to some extent and is less likely to roll. In this way, simply by making the longitudinal directions of the compressor 21, which is a heavy object, and the casing 31 different from each other, it is possible to significantly reduce the possibility that vibrations from the vehicle 10 will affect the compressor 21. Therefore, the transport refrigeration machine 2 can continue to be operated more stably over a long period of time.

[0024] According to the above configuration, the hardness of the second vibration-isolating rubber 33 is higher than the hardness of the first vibration-isolating rubber 32. As a result, low-frequency vibrations transmitted from the vehicle 10 to the compressor 21 via the casing 31 are attenuated by the first vibration-isolating rubber 32, which has a lower hardness, and are less likely to be transmitted to the compressor 21 or surrounding piping. This is because an elastic body with a lower hardness is more likely to elastically deform in response to low-frequency vibrations and absorb the vibrations. Conversely, high-frequency vibrations generated by driving the compressor 21 are attenuated by the second vibration-isolating rubber 33, which has a higher hardness, and are less likely to be transmitted to the casing 31 or the vehicle 10. In other words, according to the above configuration, it is possible to apparently separate the vibration systems between the compressor 21, the casing 31, and the vehicle 10. This reduces the possibility of the compressor 21 or piping being damaged by vibrations, and the possibility of the vibrations of the compressor 21 being transmitted to the vehicle 10, resulting in a decrease in occupant comfort.

[0025] According to the above configuration, the four second vibration-isolating rubbers 33 are located inside the rectangle R formed by the four first vibration-isolating rubbers 32. As a result, vibrations of the compressor 21 supported by the second vibration-isolating rubbers 33 are absorbed from all directions by the rectangle R formed by the four first vibration-isolating rubbers 32. This further reduces the possibility that vibrations of the compressor 21 will be transmitted to the vehicle 10 via the casing 31. As a result, the occupant comfort of the vehicle 10 is improved, and the impact of vibrations being transmitted to cargo can be minimized.

[0026] According to the above configuration, the rubber body 73 of the first vibration-damping rubber 32 does not have a through-hole. Therefore, even when vibrations are applied in the width direction A or the traveling direction B, the vibrations can be absorbed and damped solely by the rubber body 73. Conversely, in a configuration in which through-holes are formed in the rubber body 73 and bolts or the like are inserted through the through-holes to connect the casing 31 and the top surface 16, vibrations in the height direction are absorbed by the rubber body 73. Meanwhile, the bolts themselves, which are not elastic, resist vibrations in the traveling direction B or the width direction A (i.e., vibrations in the direction in which shear stress occurs). As a result, this configuration does not provide sufficient damping force against vibrations in the traveling direction B or the width direction A. In contrast, according to the above configuration, the rubber body 73 can exert absorption and damping force in both directions. Therefore, the vibration systems of the casing 31 and the vehicle 10 can be more effectively separated, further suppressing vibration propagation between them.

[0027] According to the above configuration, it is possible to provide a transport refrigeration machine 2 that can more stably withstand vibrations during travel. Furthermore, according to the above configuration, it is possible to provide a transport refrigeration vehicle 1 that can continue to operate stably even under conditions where vibrations are applied.

[0028] (Other Embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope that does not deviate from the gist of the present disclosure are also included.

[0029] For example, in the above embodiment, an example has been described in which the longitudinal direction of the casing 31 is the width direction A of the vehicle 10, and the longitudinal direction of the compressor 21 is the traveling direction B of the vehicle 10. However, as a modified example, as shown in Fig. 6, it is also possible to arrange the external unit 3 so that the longitudinal direction of the casing 31 is the traveling direction B of the vehicle 10, and the longitudinal direction of the compressor 21 is the width direction A. Even in this case, the same effects as those described above can be obtained.

[0030] Furthermore, the type of compressor 21 is not limited to the above-mentioned hermetic rotary compressor, but may be an open type, or a scroll type or a scuro-rotary type.

[0031] Furthermore, the longitudinal direction of the casing 31 and the longitudinal direction of the compressor 21 do not necessarily need to be perpendicular to each other, and may extend in directions intersecting at an angle of less than 90 degrees as long as they are in different directions. Even in this case, the same effects as those described above can be obtained.

[0032] Furthermore, the shape of the rubber body 73 of the first vibration-isolating rubber 32 and the second vibration-isolating rubber 33 is not limited to that of the above embodiment. As another example, the rubber body 73 may be cylindrical and extend in the vertical direction. On the other hand, if the rubber body 73 is shaped like a truncated cone as in the above embodiment, this is advantageous because it can more stably support the weight of the device located above, i.e., the casing and compressor.

[0033] Furthermore, the configuration of the refrigeration cycle device 20 is not limited to the above embodiment. For example, the accumulator 27b and the oil separator 28 may be omitted.

[0034] <Additional Notes> The external unit 3, transport refrigeration machine 2, and transport refrigeration vehicle 1 described in each embodiment can be understood, for example, as follows.

[0035] (1) The external unit 3 of the first aspect is mounted on the top surface 16 of the vehicle 10 and comprises a rectangular casing 31 with its longitudinal direction being either the direction of travel B or the width direction A of the vehicle 10, and a compressor 21 disposed inside the casing 31 and driven to rotate around an axis X extending in the other of the direction of travel B and the width direction A.

[0036] According to the above configuration, the longitudinal direction of the compressor 21, which is the main heavy object, is different from the longitudinal direction of the casing 31. This reduces the possibility that vibrations caused by unevenness of the road surface while the vehicle 10 is traveling will be transmitted to the compressor 21.

[0037] (2) The external unit 3 according to the second aspect is the external unit 3 of (1), further comprising a first vibration-damping rubber 32 arranged between the top surface 16 and the casing 31, and a second vibration-damping rubber 33 arranged between the casing 31 and the compressor 21, and the hardness of the second vibration-damping rubber 33 is higher than the hardness of the first vibration-damping rubber 32.

[0038] According to the above configuration, the hardness of the second vibration-isolating rubber 33 is higher than the hardness of the first vibration-isolating rubber 32. According to the above configuration, it is possible to apparently separate the vibration systems among the compressor 21, the casing 31, and the vehicle 10.

[0039] (3) The external unit 3 according to the third aspect is the external unit 3 of (2), in which four first vibration-damping rubbers 32 are provided corresponding to the four corners of the casing 31, four second vibration-damping rubbers 33 are provided surrounding the compressor 21, and the four second vibration-damping rubbers 33 are located inside the rectangle R formed by the four first vibration-damping rubbers 32.

[0040] According to the above configuration, the four second vibration-isolating rubbers 33 are located inside the rectangle R formed by the four first vibration-isolating rubbers 32. As a result, vibrations of the compressor 21 supported by the second vibration-isolating rubbers 33 are absorbed from all directions by the rectangle R formed by the four first vibration-isolating rubbers 32. This further reduces the possibility that vibrations of the compressor 21 will be transmitted to the vehicle 10 side via the casing 31.

[0041] (4) The exterior unit 3 relating to the fourth aspect is the exterior unit 3 of (3), in which the first vibration-damping rubber 32 comprises a pair of plate members 71 respectively provided on the top surface 16 side and the inner bottom surface 62 side of the casing 31, and a rubber main body 73 provided between the pair of plate members 71.

[0042] According to the above configuration, since no through holes are formed in the rubber body 73 of the first vibration-damping rubber 32, even if vibrations are applied in the width direction A or the traveling direction B, the vibrations can be absorbed and damped by the rubber body 73 alone.

[0043] (5) The exterior unit 3 according to the fifth aspect is the exterior unit 3 of (3) or (4), wherein the second vibration-damping rubber 33 comprises a pair of plate members 71 respectively provided on the outer bottom surface 61 side of the casing 31 and on the compressor 21 side, and a rubber main body 73 provided between the pair of plate members 71.

[0044] According to the above configuration, since no through holes are formed in the rubber body 73 of the second vibration-damping rubber 33, even if vibrations are applied in the width direction A or the traveling direction B, the vibrations can be absorbed and damped by the rubber body 73 alone.

[0045] (6) The transport refrigeration machine 2 according to the sixth aspect includes an external unit 3 according to any one of aspects (1) to (5), and an evaporator 24, a condenser 22, and an expansion valve 23 that together with the compressor 21 constitute a refrigeration cycle device 20.

[0046] According to the above configuration, it is possible to provide a transport refrigeration machine 2 that can more stably resist vibrations during travel.

[0047] (7) A transport refrigerated vehicle 1 according to a seventh aspect includes the transport refrigeration machine 2 of (6) and a vehicle body 11 on which the transport refrigeration machine 2 is mounted.

[0048] According to the above configuration, it is possible to provide a refrigerated transport vehicle 1 that can continue to operate stably even under conditions where vibration is applied.

[0049] According to the present disclosure, it is possible to provide an external unit, a transport refrigeration machine, and a transport refrigeration vehicle that can more stably withstand vibrations during driving.

[0050] REFRIGERATED VEHICLE FOR TRANSPORTATION 2 REFRIGERATED EQUIPMENT MACHINE 3 EXTERNAL UNIT 4 INDOOR UNIT 10 VEHICLE 11 VEHICLE BODY 12 BODY 13 WHEEL 14 DRIVERS' CAB 15 FRIGERATING COMPARTMENT 16 TOP 20 REFRIGERATION CYCLE DEVICE 21 COMPRESSOR 22 CONDENSER 22a FIRST PORTION 22b SECOND PORTION 23 EXPANSION VALVE 24 EVAPORATOR 25 FIRST FAN 26 SECOND FAN 27a RECEIVER 27b ACCUMULATOR 28 OIL SEPARATOR 29 CIRCULATION LINE 31 CASING 32 FIRST VIBRATION-ISOLATING RUBBER 33 SECOND VIBRATION-ISOLATING RUBBER 50 ELECTRICAL BOX 51 FIRST VIBRATION-ISOLATING RUBBER 52 SECOND VIBRATION-ISOLATING RUBBER 60 BOTTOM 61 EXTERNAL BOTTOM 62 INNER BOTTOM 63 TOP 64 SIDE 71 PLATE 72 JOINT 73 RUBBER BODY A... Width direction B... Traveling direction R... Rectangle X... Axis

Claims

1. An external unit comprising: a rectangular casing mounted on the top surface of a vehicle, with its longitudinal direction being either the direction of travel or the width of the vehicle; and a compressor disposed inside the casing and driven to rotate around an axis extending in the other of the direction of travel or the width.

2. An exterior unit as described in claim 1, further comprising: a first vibration-damping rubber arranged between the top surface and the casing; and a second vibration-damping rubber arranged between the casing and the compressor, wherein the hardness of the second vibration-damping rubber is higher than the hardness of the first vibration-damping rubber.

3. An exterior unit as described in claim 2, wherein the first vibration-damping rubbers are provided corresponding to the four corners of the casing, four second vibration-damping rubbers are provided surrounding the compressor, and the four second vibration-damping rubbers are located inside the rectangle formed by the first vibration-damping rubbers.

4. An exterior unit as described in claim 3, wherein the first vibration-damping rubber comprises a pair of plate members respectively provided on the top surface side and the inner bottom surface side of the casing, and a rubber body provided between the pair of plate members.

5. An exterior unit as described in claim 3 or 4, wherein the second vibration-damping rubber comprises a pair of plate members respectively provided on the outer bottom surface side of the casing and on the compressor side, and a rubber body provided between the pair of plate members.

6. A transport refrigeration machine comprising: an external unit according to any one of claims 1 to 4; and an evaporator, a condenser, and an expansion valve which, together with the compressor, constitute a refrigeration cycle device.

7. A refrigerated transport vehicle comprising: the transport refrigeration machine according to claim 6; and a vehicle body on which the transport refrigeration machine is mounted.

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