High-voltage circuit unit and refrigeration machine for transportation

Abstract

To provide a high-voltage circuit unit having higher refrigeration performance and a refrigeration machine for transportation.SOLUTION: A high-voltage circuit unit comprises: a high-voltage circuit body having an inverter which converts power from a battery unit to be supplied to a refrigeration cycle device and a DC converter which generates DC current for driving an auxiliary unit; a rectangular parallelepiped casing which accommodates the high-voltage circuit body; a heat sink thermally connected with the inverter and the DC converter; and a radiation fan which pumps the air to the heat sink, wherein a cooling passage recessed toward a front side and extending in a horizontal direction is formed on a back face of the casing, and the heat sink is arranged on one side in the horizontal direction of the cooling passage.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a high-voltage circuit unit and a transport refrigeration machine. [Background technology]

[0002] For example, a vehicle for transporting cargo at low temperatures, such as a refrigerated truck, is equipped with a transport refrigeration machine. The transport refrigeration machine is equipped with a refrigeration cycle device that mainly includes a compressor, a condenser, an expansion valve, and an evaporator. Conventionally, the components that make up the refrigeration cycle device and the high-voltage circuit unit that makes up the electrical circuit system have generally been placed under the floor of the vehicle, i.e., below the chassis (see, for example, Patent Document 1 below).

[0003] In recent years, electric vehicles that use battery units (storage batteries) to generate the power they need to run have come into practical use. These types of battery units tend to be larger in size in order to ensure a long driving distance. For this reason, battery units are generally housed and fixed below the chassis of the vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2004-526120 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the battery unit is large as described above, and a high-voltage circuit unit is placed below the chassis, the battery unit and the high-voltage circuit unit are placed close to each other, which poses a problem that it is not possible to secure a sufficient air passage for cooling the circuit elements included in the high-voltage circuit unit.

[0006] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a high-voltage circuit unit and a transport refrigeration machine having higher cooling performance. [Means for solving the problem]

[0007] In order to solve the above problems, the high-voltage circuit unit of the present disclosure is a high-voltage circuit unit that is mounted on a transport vehicle and is used to drive a transport refrigeration machine having a refrigeration cycle device, and includes a high-voltage circuit main body having an inverter that converts power from a battery unit and supplies it to the refrigeration cycle device, and a DC converter that generates DC current to drive auxiliary equipment, a rectangular casing that houses the high-voltage circuit main body, a heat sink thermally connected to the inverter and the DC converter, and a heat dissipation fan that pressurizes air toward the heat sink, and a cooling flow path is formed on the back of the casing that is recessed toward the front side and extends horizontally, and the heat sink is arranged on one horizontal side of the cooling flow path.

[0008] A transport refrigeration machine according to the present disclosure includes the above-described high-voltage circuit unit and a refrigeration cycle unit driven by the high-voltage circuit unit. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a high-voltage circuit unit and a transport refrigeration machine having higher cooling performance. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating the configuration of a vehicle and a transport refrigeration machine according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a transparent plan view showing the configuration under the chassis of the vehicle according to the embodiment of the present disclosure. [Figure 3] 1 is a refrigerant circuit diagram showing a configuration of a refrigeration cycle device according to an embodiment of the present disclosure. [Figure 4]FIG. 1 is an electrical circuit diagram illustrating an electrical system of a transport refrigeration machine according to an embodiment of the present disclosure. [Figure 5] FIG. 2 is a front view illustrating a configuration of a high-voltage circuit unit according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is a rear view illustrating the configuration of a high-voltage circuit unit according to an embodiment of the present disclosure. [Figure 7] 6 is a view seen from the direction of arrow A in FIG. 5. [Figure 8] 6 is a view seen from the direction of arrow B in FIG. 5. [Figure 9] FIG. 6 is a cross-sectional view taken along line XX in FIG. 5. [Figure 10] FIG. 2 is a functional block diagram showing a configuration of a control unit according to an embodiment of the present disclosure. [Figure 11] 10 is a flowchart illustrating a control flow of a control unit according to an embodiment of the present disclosure, showing processing during normal operation. [Figure 12] 10 is a flowchart illustrating a control flow of a control unit according to an embodiment of the present disclosure, showing processing at the time of initial setting. [Figure 13] FIG. 2 is a hardware configuration diagram of a control unit according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment Hereinafter, a transport refrigeration machine 1 according to a first embodiment of the present disclosure will be described with reference to FIGS.

[0012] (Transport vehicle configuration) First, a transport vehicle 90 on which the transport refrigeration machine 1 is mounted will be described with reference to Figures 1 and 2. As shown in the figures, the transport vehicle 90 includes a vehicle body 91, the transport refrigeration machine 1, and an electric circuit system 3.

[0013] The vehicle body has a chassis 92, a plurality of wheels 93, a container 94, and a cabin 95. The chassis 92 is shaped like a girder extending in the traveling direction of the transport vehicle 90. As shown in FIG. 2, one example is a chassis 92 ladder frame. The plurality of wheels 93 are provided in pairs on both sides of the width direction of the chassis 92. At least some of the plurality of wheels 93 are driven to rotate by the driving force of an engine or an electric motor (not shown) mounted on the chassis 92. In addition, a cabin 95 is attached to the front portion of the chassis 92. The cabin 95 is a housing that houses a driving device, a driver's cab, etc. A container 94 is provided behind the cabin 95. The container 94 is shaped like a rectangular parallelepiped, for example, and has a space serving as a freezer compartment V formed inside.

[0014] (Chassis bottom configuration) 1 or 2, in addition to the devices that make up the transport refrigeration machine 1, a battery unit 2 is mounted (mounted) below the chassis 92. As will be described in detail later, this battery unit 2 is a storage battery that supplies power to the devices, for example, to generate power for running the transport vehicle 90 and to drive the transport refrigeration machine 1.

[0015] More specifically, as shown in Figure 2, the ladder-frame-shaped chassis 92 has a pair of frames 96 that extend in the traveling direction and are arranged at a distance in the vehicle width direction. These frames 96 are connected to each other by beams (not shown) that extend in the vehicle width direction. The battery units 2 are distributed and arranged on both sides of these frames 96 in the vehicle width direction.

[0016] Furthermore, in the spaces between the battery units 2, some of the devices (described later) that make up the transport refrigeration machine 1 are mounted.

[0017] (Configuration of transport refrigeration machine 1) Next, the configuration of the transport refrigeration machine 1 will be described with reference to Figure 3. As shown in the figure, the transport refrigeration machine 1 includes a refrigeration cycle device 4.

[0018] (Configuration of refrigeration cycle device) The refrigeration cycle device 4 has a compressor 41, a condenser 42, an expansion valve 43, an evaporator 44, an accumulator 48, a receiver 47, a condenser fan 45, an evaporator fan 46, an oil separator 49, and a refrigerant line L.

[0019] The refrigerant line L is filled with refrigerant. The refrigerant line L is a closed pipe that forms a loop as a whole. A compressor 41, a condenser 42, an expansion valve 43, and an evaporator 44 are arranged in this order on the refrigerant line L. The compressor 41 compresses the refrigerant and discharges high-temperature, high-pressure refrigerant. The condenser 42 is a heat exchanger that exchanges heat between the compressed refrigerant and external air. Specifically, a fin-and-tube or plate-type heat exchanger is preferably used as the condenser 42. The expansion valve 43 expands the refrigerant to reduce its pressure and temperature. The evaporator 44 cools the air in the freezing compartment V by exchanging heat between the low-temperature refrigerant and the air in the freezing compartment V. The evaporator 44 is attached to the ceiling of the freezing compartment V (see FIG. 1). The refrigerant heated by the heat exchange in the evaporator 44 flows back into the compressor 41. The refrigeration cycle device 4 operates by continuously performing the above cycle.

[0020] The condenser fan 45 is a blower device provided next to the condenser 42. Driving the condenser fan 45 promotes efficient supply of outside air to the condenser 42. The evaporator fan 46 is a blower device provided next to the evaporator 44. Driving the evaporator fan 46 promotes supply of air from the freezing compartment V to the evaporator 44. The accumulator 48 and the receiver 47 are provided to separate the refrigerant into gas and liquid. The accumulator 48 is provided between the evaporator 44 and the compressor 41, and the receiver 47 is provided between the condenser 42 and the expansion valve 43. The oil separator 49 is a device that removes lubricating oil (grease) contained in the refrigerant discharged from the compressor 41 from the refrigerant and returns the removed oil to the compressor 41.

[0021] (Configuration of electrical circuit system) The refrigeration cycle device 4 is driven by an electric circuit system 3. As shown in FIG.

[0022] The battery unit 2 has a high-voltage battery 33 and a low-voltage battery 34. The high-voltage battery 33 generates a direct current with a higher voltage than the low-voltage battery 34. A high-voltage circuit 31 is connected to the high-voltage battery 33. The high-voltage circuit 31 has an inverter 52 and a DC-DC converter 51.

[0023] The inverter 52 generates an AC current having a predetermined frequency and voltage from the DC current supplied by the high-voltage battery 33. This AC current is supplied to the electric motor 100 which is the drive source of the compressor 41.

[0024] The DC-DC converter 51 is a device for converting the voltage of the direct current supplied from the high-voltage battery 33. Specifically, the DC-DC converter 51 is a step-down converter. The direct current whose voltage has been converted is supplied to the low-voltage circuit 32.

[0025] The low-voltage circuit 32 has a main circuit 61, a communication circuit 62, and a relay circuit 63. The main circuit 61 executes processing for controlling the operation of the inverter 52 based on a pre-stored program. The main circuit 61 receives input signals such as the set temperature in the freezing compartment V from a cabin controller 64 provided in the cabin 95. The main circuit 61 outputs a control signal for operating the inverter 52 so that the temperature in the freezing compartment V is maintained at the set temperature based on detection signals from temperature sensors 400 (not shown) provided inside and outside the freezing compartment V. The control signal output from the main circuit 61 is transmitted to the inverter 52 via the communication circuit 62.

[0026] The relay circuit 63 is electrically connected to the main circuit 61. Based on signals output from the main circuit 61, the relay circuit 63 controls the operation of the condenser fan 45 and the evaporator fan 46, as well as the open / closed states of various sensors, various valves, and the expansion valve 43.

[0027] (Configuration of each unit) The compressor 41 and condenser 42 included in the refrigeration cycle device 4 configured as described above, and the high-voltage circuit 31 and low-voltage circuit 32 included in the electrical circuit system 3 can be distributed and arranged in various parts of the transport vehicle 90 as independent units.

[0028] Specifically, as shown in FIG. 1 or 2, in this embodiment, these units are mounted in the space between the battery units 2 below the chassis 92. In the following description, a unit including the compressor 41 will be referred to as a "compressor unit 71." The compressor unit 71 has a container-shaped compressor unit casing (not shown) and the compressor 41 housed therein. A unit including the condenser 42 will be referred to as a "condenser unit 72." The condenser unit 72 has a container-shaped condenser unit casing (not shown) and the condenser 42 housed therein. A unit that houses the high-voltage circuit 31 will be referred to as a "high-voltage circuit unit 73." The high-voltage circuit unit 73 has a container-shaped high-voltage circuit unit casing (casing 202 described below) and the high-voltage circuit 31 housed therein. A unit that houses the low-voltage circuit 32 will be referred to as a "low-voltage circuit unit 74." The low-voltage circuit unit 74 has a container-shaped low-voltage circuit unit casing (not shown) and the low-voltage circuit 32 housed therein.

[0029] 2, high-voltage circuit unit 73 and low-voltage circuit unit 74 are disposed in a front portion of frame 96 on the left side as viewed in the direction of travel, so as to overlap in the vehicle width direction. Compressor unit 71 and condenser unit 72 are disposed in a rear portion of frame 96 on the left side as viewed in the direction of travel, so as to overlap in the vehicle width direction.

[0030] (High voltage circuit unit configuration) Next, the configuration of the high-voltage circuit unit 73 will be described in detail with reference to Figures 5 to 9. As shown in Figures 5 and 6, the high-voltage circuit unit 73 has a high-voltage circuit main body 201, a casing 202, a heat sink 110, a fan box 203, a harness 204, a harness holding unit 205, and a control unit 206.

[0031] The high-voltage circuit main body 201 has the above-mentioned inverter 52 and a DC converter (DC-DC converter 51). The inverter 52 and the DC converter are each mounted on a substrate, and include circuit elements (not shown) such as power transistors and FETs as heat sources.

[0032] The casing 202 has a rectangular parallelepiped shape with a top surface 81, a bottom surface 82, side surfaces 83, a front surface 84, and a back surface 85. A space is formed inside the casing 202 to accommodate the high-voltage circuit main body 201, the relay circuit 63, the communication circuit 62, and the like. The high-voltage circuit main body 201 is disposed in a position biased toward the upper side within the casing 202. The inverter 52 and the DC converter are arranged at intervals in the direction connecting the side surfaces 83. The inverter 52 and the DC converter are positioned at the same height. As an example, the inverter 52 has a larger area when viewed from the front surface 84 than the DC-DC converter 51.

[0033] As shown in Fig. 6 or 8, a cooling channel 300 is formed in the back surface 85 of the casing 202. The cooling channel 300 has a rectangular cross-sectional shape that is recessed from the back surface 85 toward the front surface 84. The cooling channel 300 extends horizontally so as to penetrate from one side surface 83 to the other side surface 83. In other words, when the high-voltage circuit unit 73 is mounted below the chassis 92 of a transportation vehicle 90, the direction in which the cooling channel 300 extends coincides with the running direction (direction of travel) of the vehicle. The height position and height dimension of the cooling channel 300 on the back surface 85 are desirably dimensions that can cover the inverter 52 and the DC converter from the back surface 85 side.

[0034] 9, the cooling flow path 300 has a flow contraction section 301 and a flow path main body 302 that continue from one side surface 83 side (inlet side) to the other side surface 83 side (outlet side). In the flow contraction section 301, the flow path cross-sectional area gradually decreases from the inlet side to the outlet side. In other words, the flow path cross-sectional area gradually decreases from the upstream side to the downstream side in the direction of air blown by the heat dissipation fan 211 (described later). It is desirable that the rate of decrease in the flow path cross-sectional area of ​​the flow contraction section 301 is linear. The downstream side (i.e., the outlet side) of the flow contraction section 301 is connected to the flow path main body 302. The flow path cross-sectional area of ​​the flow path main body 302 is constant throughout its entire extension length.

[0035] A heat sink 110 is accommodated within the cooling flow path 300 (flow path main body 302). The heat sink 110 is disposed on a bottom surface 303 of the recess of the cooling flow path 300. As shown in FIG. 8, the heat sink 110 includes a cooling plate 111 extending along the bottom surface 303 of the recess and a plurality of fins 112 (or pins) formed integrally with the cooling plate 111. The fins 112 are plate-shaped and protrude from the surface of the cooling plate 111, extending in a direction connecting the side surfaces 83 of the cooling plate 111. That is, each fin 112 extends in the same direction as the extension of the cooling flow path 300. The fins 112 are arranged in a vertically spaced relationship. Two such heat sinks 110 are provided, one at a position corresponding to the inverter 52 and the other at a position corresponding to the DC converter. Furthermore, as shown in FIG. 9, each heat sink 110 is provided with a temperature sensor 400 for measuring the temperature of the heat sink 110 itself. More specifically, the heat sink 110 is in direct contact with the inverter 52 and the DC converter through an opening formed in the bottom surface 303 of the recess. The high-voltage circuit main body 201, which includes the inverter 52 and the DC-DC converter 51, includes an element main body 201a, a substrate 201b, and a spacer 201c. The element main body 201a is mounted on the substrate 201b and fixed to the periphery of the opening via the spacer 201c. The temperature sensor 400 is disposed in a position facing the opening of the heat sink 110. The temperature sensor 400 sequentially transmits the temperature value of the heat sink 110 as an electrical signal to a control unit 206 (described below).

[0036] A fan box 203 is attached to one side of the side surface 83 of the casing 202. The fan box 203 is provided to forcibly send external air as cooling air into the cooling flow path 300. As shown in FIG. 7 , the fan box 203 includes a heat dissipation fan 211 for supplying cooling air into the cooling flow path 300, a box body 212 that houses the heat dissipation fan 211, and an intake panel 213 that protects the heat dissipation fan 211. The heat dissipation fan 211 includes an impeller that can rotate about a rotation axis that extends in the traveling direction of the vehicle, and a motor (not shown) that drives the impeller. As an example, two heat dissipation fans 211 are provided, spaced apart in the vertical direction. The heat dissipation fan 211 is covered from the outside by the intake panel 213. The intake panel 213 is a member that prevents foreign objects from being sucked into the heat dissipation fan 211 and has a mesh or net-like shape. When viewed from the side surface 83, the intake panel 213 extends to a midpoint in the direction from the rear surface 85 toward the front surface 84. In other words, the width of the heat dissipation fan 211 is equal to the width of the inlet of the cooling flow path 300.

[0037] A harness holding portion 205 is provided on the side surface 83 of the casing 202 at a position different from the inlet of the cooling flow path 300. The harness holding portion 205 is disposed on a surface facing the front surface 84 of the fan box 203 so as not to overlap with the inlet of the cooling flow path 300. The harness holding portion 205 holds a harness 204 (various wiring) extending in the vertical direction. The harness 204 includes wiring for supplying current to the motor of the heat dissipation fan 211 and a control unit 206 (described later) and for transmitting and receiving control signals. The harness holding portion 205 and the fan box 203 can be attached to both of the pair of side surfaces 83. In other words, bolt holes and the like for attaching the harness holding portion 205 and the fan box 203 are formed on the side surface 83 different from the side surface 83 on which the harness 204 is actually laid.

[0038] (Configuration of control unit) Next, the configuration (functional blocks) of the control unit 206 will be described with reference to Fig. 10. The control unit 206 is a device for controlling the driving state of the heat dissipation fan 211. As shown in Fig. 10, the control unit 206 has a temperature acquisition unit 221, a determination unit 222, an adjustment unit 223, a switching unit 224, and a storage unit 225.

[0039] The temperature acquisition unit 221 acquires the temperature of the heat sink 110 measured by the temperature sensor 400. The acquired temperature values ​​are sequentially stored in the storage unit 225. The determination unit 222 determines whether the temperature of the heat sink 110 (hereinafter simply referred to as the "measured temperature") is higher or lower than a predetermined first threshold value. Here, the first threshold value refers to a temperature slightly lower than the derated temperature of the inverter 52 or the DC converter. The derated temperature refers to an operating temperature that allows a margin above the rated operating temperature of the circuit elements. The first threshold value is pre-stored in the storage unit 225. Furthermore, the storage unit 225 also pre-stores a second threshold value that is lower than the first threshold value. Here, the first threshold value and the second threshold value are set assuming that the temperature of the heat sink 110 is equal to the operating temperature of these circuit elements. The adjustment unit 223 increases or decreases the rotation speed of the heat dissipation fan 211 based on the determination result of the determination unit 222. The switching unit 224 switches the rotation direction of the heat dissipation fan 211 based on the determination result of the determining unit 222 .

[0040] (Processing flow of the control unit: during normal operation) Next, with reference to Fig. 11, a processing flow during normal operation of the control unit 206 will be described. During normal operation, first, in step S1, the inverter 52 and the DC converter (collectively referred to as the power module in the figure) start operating. Next, in step S2, the above-mentioned derating temperature T0 is acquired from the storage unit 225 by the determination unit 222. In step S3, the first threshold value T1 is similarly acquired from the storage unit 225 by the determination unit 222. In step S4, the second threshold value is similarly acquired from the storage unit 225 by the determination unit 222. In step S5, the heat dissipation fan 211 starts operating at an initial rotation speed S0.

[0041] Then, in step S6, the temperature acquisition unit 221 acquires the temperature Ts of the heat sink 110. In step S7, the determination unit 222 determines whether the temperature Ts is lower than the first threshold value T1. Specifically, it is determined whether the temperature Ts is lower than the first threshold value T1 by a value within a range of 2°C to 10°C. Desirably, this temperature difference is 5°C. If it is determined in step S7 that the temperature Ts is higher than the first threshold value T1 (step S7: No), in step S8 the adjustment unit 223 adjusts the rotation speed of the heat dissipation fan 211 in a direction increasing it from the initial rotation speed S0.

[0042] Thereafter, the determination in step S7 is repeated again. On the other hand, if the determination in step S7 is Yes, then in step S9, the determination unit 222 determines whether the temperature Ts is lower than the second threshold value T2. If the determination in step S9 is No, then step S8 is executed again, and the rotation speed of the heat dissipation fan 211 is adjusted to increase. On the other hand, if the determination in step S9 is Yes, then in step S10, the adjustment unit 223 adjusts the rotation speed of the heat dissipation fan 211 to decrease it. Thereafter, steps S7 to S10 are appropriately repeated until the operation of the high-voltage circuit unit 73 is finished. This completes the processing flow during normal operation of the control unit 206.

[0043] (Processing flow of the control unit: Initial setting) Next, the processing flow of the control unit 206 at the time of initial setup will be described with reference to Fig. 12. "At the time of initial setup" here refers to the state immediately after the high-voltage circuit unit 73 is mounted on the transport vehicle 90 and the first operation is started. In other words, the processing flow described below is executed in advance prior to the processing flow during normal operation described above.

[0044] In this processing flow, first, in step S11, the transport vehicle 90 is driven. This is to introduce wind (driving wind) caused by the vehicle's movement into the cooling flow path 300. In step S12, the inverter 52 and the DC converter (i.e., the power module) are started to operate. In step S13, the adjustment unit 223 drives the heat dissipation fan 211 in a forward rotation state for a predetermined fixed time. Next, in step S14, the temperature acquisition unit 221 acquires a temperature T3 of the heat sink 110. Further, in the subsequent step S15, the adjustment unit 223 drives the heat dissipation fan 211 in a reverse rotation state for a predetermined fixed time. Next, in step S16, the temperature acquisition unit 221 acquires a temperature T4 of the heat sink 110.

[0045] After the above steps are performed, in step S17, the determination unit 222 determines the magnitude relationship between the temperature T3 and the temperature T4. Specifically, it is determined whether the temperature T3 is lower than the temperature T4. If the determination in step S17 is Yes, in step S18, the switching unit 224 determines (initializes) to rotate the heat dissipation fan 211 in the forward direction as long as the high-voltage circuit unit 73 is mounted on the specific transport vehicle 90. Conversely, if the determination in step S17 is No, in step S19, the switching unit 224 determines to rotate the heat dissipation fan 211 in the reverse direction as long as the high-voltage circuit unit 73 is mounted on the specific transport vehicle 90. This completes the processing flow of the control unit 206 during initial setup.

[0046] Although not shown in the figures, in addition to the above processing flow, the switching unit 224 is configured to be able to switch between a reverse mode in which the rotation direction of the heat dissipation fan 211 is reversed to push air out of the cooling flow path 300 and operated for a certain period of time, and a normal mode in which the rotation direction of the heat dissipation fan 211 is reversed to allow air to flow into the cooling flow path 300.

[0047] (Action and effect) In recent years, electric vehicles that use a battery unit 2 (storage battery) to generate power for driving have come into practical use. This type of battery unit 2 tends to be larger in size in order to ensure a long driving distance. For this reason, the battery unit 2 is generally housed and fixed below the chassis 92 of the vehicle.

[0048] However, if the battery unit 2 is large, and the high-voltage circuit unit 73 is disposed below the chassis 92, the battery unit 2 and the high-voltage circuit unit 73 will be disposed close to each other. This poses a problem in that it is not possible to secure a sufficient air passage for cooling the circuit elements included in the high-voltage circuit unit 73. To solve this problem, the present embodiment employs the above-described configurations.

[0049] According to the above configuration, the cooling channel 300 is formed on the back surface 85 of the casing 202. Therefore, even if other structures are placed close to the front surface 84, a stable supply of air to the cooling channel 300 can be ensured. Furthermore, the heat dissipation fan 211 pressurizes air through the cooling channel 300, promoting heat exchange between the heat sink 110 and the cooling air. This allows for efficient dissipation of heat from the high-voltage circuit main body 201, thereby maintaining stable operation of the circuit for a long period of time. On the other hand, if the cooling channel 300 is formed on a surface other than the back surface 85, the cooling channel 300 may be blocked by being placed close to, for example, the battery unit 2. This could impede the supply of air to the cooling channel 300 and potentially disrupt stable operation of the high-voltage circuit main body 201. However, according to the above configuration, a stable supply of cooling air is ensured, minimizing the risk of thermal runaway or damage to circuit elements and enabling stable operation of the high-voltage circuit main body 201.

[0050] According to the above configuration, the inverter 52 and the DC converter (DC-DC converter 51), which are heavy objects, are disposed at positions offset upward within the casing 202. As a result, for example, when the high-voltage circuit unit 73 is suspended below the chassis 92 of the vehicle, the center of gravity of the high-voltage circuit unit 73 is brought closer to the chassis 92. As a result, even if an external force such as vibration is applied while the vehicle is traveling, the extent of the vibration of the high-voltage circuit unit 73, with the chassis 92 as a fulcrum, is minimized. This makes it possible to significantly reduce the possibility of the high-voltage circuit unit 73 falling off or malfunctioning, even if it is exposed to an external force while traveling.

[0051] Furthermore, with the above configuration, the heat sink 110 and the heat dissipation fan 211 are disposed at positions biased upward in the casing 202. This ensures a sufficient distance from the ground to the heat dissipation fan 211, thereby reducing the possibility that melted snow, rainwater, dust, and the like will be sucked into the cooling flow path 300 by the heat dissipation fan 211 while the vehicle is running. This allows the high-voltage circuit unit 73 to continue operating more stably.

[0052] According to the above configuration, since the cooling flow path 300 has the flow contraction section 301, the flow velocity of the cooling air can be increased downstream of the flow contraction section 301. As a result, a larger flow rate of air comes into contact with the high-voltage circuit main body 201, making it possible to cool the circuit main body more efficiently. Furthermore, since the diameter of the heat dissipation fan 211 can be increased, the rotation speed of the heat dissipation fan 211 to achieve the same flow rate can be relatively reduced. This makes it possible to minimize noise associated with driving the heat dissipation fan 211. As a result, the environmental impact and noise of the transport vehicle 90 as a whole can be significantly reduced.

[0053] According to the above configuration, the harness holding portion 205 is provided at a position different from the inlet of the cooling flow path 300. This inevitably allows the harness 204 to be laid without overlapping the inlet. This reduces the possibility that the inlet of the cooling flow path 300 will be blocked by the harness 204. As a result, it becomes possible to continue to stably supply more cooling air to the cooling flow path 300. Therefore, it becomes possible to continue to cool the high-voltage circuit main body 201 more efficiently, thereby realizing stable operation of the circuit main body for a long period of time.

[0054] Here, when the high-voltage circuit unit 73 is suspended below the chassis 92, whether the unit is installed on the left or right side in the vehicle width direction may differ depending on the vehicle model and other conditions. For this reason, if the harness holding portion 205 is arranged on only one of the side surfaces 83 of the casing 202, the inlet side of the cooling flow path 300 is necessarily determined, and there is a possibility that wind (traveling wind) caused by the vehicle traveling will not be able to flow in from the inlet. However, with the above configuration, the harness holding portion 205 is provided on both of the pair of side surfaces 83 of the casing 202, so that the inlet side of the cooling flow path 300 can be selectively determined regardless of which side in the vehicle width direction the high-voltage circuit unit 73 is arranged on. Therefore, the degree of freedom in the layout of the high-voltage circuit unit 73 is increased, and the versatility of the transport refrigeration machine 1 including the unit can be further improved.

[0055] According to the above configuration, cooling flow path 300 extends in the same direction as the vehicle's traveling direction, and as the vehicle travels, it becomes possible to efficiently take in traveling wind from the inlet of cooling flow path 300. This ensures a stable supply of cooling air, minimizing the risk of thermal runaway or damage to circuit elements and enabling stable operation of high-voltage circuit main body 201.

[0056] According to the above configuration, when the temperature of the heat sink 110 is determined to be higher than the first threshold, the adjustment unit 223 adjusts the rotation speed of the heat dissipation fan 211 to increase it. Therefore, when the temperature approaches the derated temperature of the inverter 52 or the DC converter, the rotation speed of the heat dissipation fan 211 can be increased to supply a larger flow rate of air to the cooling flow path 300. This allows each circuit element to be forcibly cooled before the rated operating temperature of the element is reached. This minimizes the risk of thermal runaway or damage to the circuit elements, and enables stable operation of the high-voltage circuit main body 201.

[0057] According to the above configuration, when the temperature of the heat sink 110 approaches the derated temperature, the heat dissipation fan 211 is operated at a high rotation speed. This high rotation speed operation continues until the temperature of the heat sink 110 reaches a second threshold value T2, which is lower than the first threshold value T1. This allows cooling air to be continuously supplied to the high-voltage circuit main body 201 until the temperature of the circuit main body 201 drops sufficiently. This minimizes the risk of thermal runaway or damage to the circuit elements, enabling stable operation of the high-voltage circuit main body 201.

[0058] When the high-voltage circuit unit 73 is suspended below the chassis 92, whether the unit is installed on the left or right side of the vehicle width may vary depending on the vehicle model and other conditions. On the other hand, it is desirable for the cooling flow path 300 to have an airflow from the front to the rear of the vehicle in the traveling direction. If the heat dissipation fan 211 rotates in only one direction, the airflow direction would be inevitably determined, potentially resulting in the airflow direction being opposite to the traveling direction. However, with the above configuration, the rotation direction of the heat dissipation fan 211 can be switched, allowing the cooling air flow direction to be selectively determined regardless of whether the high-voltage circuit unit 73 is installed on either side of the vehicle width. In particular, the switching unit 224 autonomously selects the appropriate rotation direction of the heat dissipation fan 211 based on whether the temperature of the heat sink 110 has decreased after receiving the cooling air. This increases the degree of freedom in the layout of the high-voltage circuit unit 73 and reduces the time and cost required for unit installation. As a result, the versatility of the transport refrigeration machine 1 including the unit can be further improved.

[0059] According to the above configuration, when the heat dissipation fan 211 is operated in the normal mode by the switching unit 224, cooling air can be continuously supplied to the cooling flow path 300. On the other hand, if operation in the normal mode is continued for a long period of time, foreign matter such as dust may accumulate in the cooling flow path 300. According to the above configuration, by operating the heat dissipation fan 211 in the reverse mode for a certain period of time, foreign matter in the cooling flow path 300 can be expelled to the outside.

[0060] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0061] For example, the configuration of the refrigeration cycle device 4 described in each of the above embodiments is merely an example and can be modified as appropriate according to the design and specifications. Specifically, the accumulator 48, the receiver 47, and the oil separator 49 can be omitted as appropriate. Even in this case, the same effects as those described above can be obtained.

[0062] In addition, in each of the above embodiments, an example has been described in which the freezer compartment V is a single space. However, depending on the specifications, the freezer compartment V can be divided into two or more compartments. In this case, by installing an evaporator 44 for each compartment, it becomes possible to adjust the temperature of each compartment independently.

[0063] In addition, the application of the transport refrigeration machine 1 is not limited to vehicles traveling on land, but the transport refrigeration machine 1 can also be applied to, for example, containers 94 for ships and railroad cars. In either case, the same effects as those described above can be obtained.

[0064] It should be noted that the order of the processes performed by the control unit 206 in the embodiment of the present disclosure may be changed as long as the processes are performed appropriately.

[0065] The storage unit 225 and other storage devices in the embodiments of the present disclosure may be provided anywhere within the range where appropriate information is transmitted and received. Furthermore, there may be multiple storage units 225 and other storage devices within the range where appropriate information is transmitted and received, and data may be stored in a distributed manner.

[0066] The above-described processing steps performed by the control unit 206 are stored in the form of a program on a recording medium that can be read by the computer 500, and the above processing is performed by the computer 500 reading and executing this program. A specific example of the computer 500 is shown below.

[0067] As shown in FIG. 13, a computer 500 includes a CPU 501, a main memory 502, a storage 503, and an interface 504. For example, the above-described control unit 206 is implemented in a computer 500. The operations of the above-described processing units are stored in the form of a program in a storage 503. The CPU 501 reads the program from the storage 503, loads it into the main memory 502, and executes the above-described processing in accordance with the program. The CPU 501 also allocates a storage area in the main memory 502 corresponding to the above-described storage unit 225 in accordance with the program.

[0068] Examples of storage 503 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), and a semiconductor memory. Storage 503 may be an internal medium directly connected to the bus of computer 500, or an external medium connected to computer 500 via interface 504 or a communication line. Furthermore, when this program is distributed to computer 500 via a communication line, computer 500 that receives the program may load the program into main memory 502 and execute the above-mentioned processing. Storage 503 is a non-transitory tangible storage medium.

[0069] The program may also implement some of the functions described above. Furthermore, the program may be a file that can implement the functions described above in combination with a program already recorded in computer 500, a so-called differential file (differential program).

[0070] In addition to or instead of the above configuration, a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device), an ASIC (Application Specific Integrated Circuit), a GPU (Graphics Processing Unit), or similar processing devices may be provided. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor may be realized by the integrated circuit.

[0071] <Additional Notes> The high-voltage circuit unit 73 described in each embodiment can be understood, for example, as follows.

[0072] (1) The high-voltage circuit unit 73 according to the first embodiment is a high-voltage circuit unit 73 mounted on a transport vehicle 90 for driving a transport refrigeration machine 1 having a refrigeration cycle device 4, and comprises a high-voltage circuit main body 201 having an inverter 52 that converts power from a battery unit 2 and supplies it to the refrigeration cycle device 4, and a DC converter that generates DC current for driving auxiliary equipment, a rectangular casing 202 that houses the high-voltage circuit main body 201, a heat sink 110 thermally connected to the inverter 52 and the DC converter, and a heat dissipation fan 211 that pressurizes air against the heat sink 110, and a cooling flow path 300 that is recessed toward the front face 84 and extends horizontally is formed on the back surface 85 of the casing 202, and the heat sink 110 is arranged on one horizontal side of the cooling flow path 300.

[0073] According to the above configuration, the cooling flow path 300 is formed on the back surface 85 of the casing 202. Therefore, even if another structure is placed close to the front surface 84, a stable supply of air to the cooling flow path 300 can be ensured. Furthermore, the heat dissipation fan 211 pressurizes and sends air to the cooling flow path 300, which promotes heat exchange between the heat sink 110 and the cooling air. Therefore, the heat of the high-voltage circuit main body 201 can be efficiently dissipated, and stable operation of the circuit can be maintained for a long period of time.

[0074] (2) A high-voltage circuit unit 73 according to a second aspect is the high-voltage circuit unit 73 of (1), in which the heat sink and the fan are disposed at positions offset upward in the casing.

[0075] According to the above configuration, the heat sink 110 corresponding to the inverter 52 and the DC converter, which are heavy objects, and the heat dissipation fan 211 are disposed in positions biased upward within the casing 202. This makes it possible to significantly reduce the possibility of high-voltage circuit unit 73 falling off or malfunctioning even if it is exposed to an external force while traveling.

[0076] (3) The high-voltage circuit unit 73 according to the third aspect is the high-voltage circuit unit 73 of (1) or (2), wherein the cooling flow path 300 has a contraction section 301 in which the cross-sectional area of ​​the flow path gradually decreases from the inlet side where the heat dissipation fan 211 is located toward the downstream side in the air blowing direction.

[0077] According to the above configuration, since the cooling flow path 300 has the flow contraction section 301, the flow velocity of the cooling air can be increased downstream of the flow contraction section 301. This makes it possible to cool the circuit main body more efficiently.

[0078] (4) The high-voltage circuit unit 73 according to the fourth aspect is a high-voltage circuit unit 73 according to any one of the aspects (1) to (3), wherein the casing 202 further has a harness holding portion 205 provided at a position different from the entrance within the plane in which the heat dissipation fan 211 is arranged, as viewed from the entrance side of the cooling flow path 300.

[0079] According to the above configuration, the harness holding portion 205 is provided at a position different from the inlet of the cooling flow path 300. This inevitably allows the harness 204 to be laid without overlapping with the inlet.

[0080] (5) A high-voltage circuit unit 73 according to a fifth aspect is the high-voltage circuit unit 73 of (4), in which the harness holding portion 205 is provided on both of the pair of side surfaces 83 of the casing 202 .

[0081] According to the above configuration, the harness holding portion 205 is provided on both of the pair of side surfaces 83 of the casing 202, so that the inlet side of the cooling flow path 300 can be selectively determined regardless of which side in the vehicle width direction the high-voltage circuit unit 73 is placed on.

[0082] (6) The high-voltage circuit unit 73 according to the sixth aspect is a high-voltage circuit unit 73 according to any one of aspects (1) to (5), wherein the cooling flow path 300 extends in the same direction as the traveling direction of the transport vehicle 90.

[0083] According to the above configuration, since the cooling flow path 300 extends in the same direction as the vehicle's traveling direction, it is possible to efficiently take in traveling wind from the inlet of the cooling flow path 300 as the vehicle travels.

[0084] (7) A high-voltage circuit unit 73 according to a seventh aspect is a high-voltage circuit unit 73 according to any one of the aspects (1) to (6), further comprising a temperature sensor 400 that acquires the temperature of the heat sink 110, and a control unit 206 that controls the operation of the heat dissipation fan 211 based on the temperature acquired by the temperature sensor 400. The control unit 206 has a temperature acquisition unit 221 that acquires the temperature from the temperature sensor 400, a judgment unit 222 that judges whether the temperature is higher than a first threshold value that is lower than the derating temperature of the inverter 52 and the DC converter, and an adjustment unit 223 that adjusts the rotation speed of the heat dissipation fan 211 based on the output of the judgment unit 222. When the judgment unit 222 judges that the temperature is higher than the first threshold value, the adjustment unit 223 adjusts the rotation speed of the heat dissipation fan 211 to be higher.

[0085] According to the above configuration, when it is determined that the temperature of the heat sink 110 is higher than the first threshold value, the adjustment unit 223 adjusts the rotation speed of the heat dissipation fan 211 to be higher. Therefore, when the temperature approaches the derated temperature of the inverter 52 or the DC converter, the rotation speed of the heat dissipation fan 211 is increased, and a larger flow rate of air can be supplied to the cooling flow path 300.

[0086] (8) The high-voltage circuit unit 73 according to the eighth aspect is the high-voltage circuit unit 73 of (7), in which the adjustment unit 223 drives the heat dissipation fan 211 at the rotation speed adjusted in the increasing direction until the judgment unit 222 judges that the temperature reaches a second threshold value that is lower than the first threshold value.

[0087] According to the above configuration, when the temperature of the heat sink 110 approaches the derating temperature, the heat dissipation fan 211 is operated at a high rotation speed. This operation at a high rotation speed continues until the temperature of the heat sink 110 reaches a second threshold value that is lower than the first threshold value. This allows cooling air to continue to be supplied to the high-voltage circuit main body 201 until the temperature of the circuit main body has sufficiently decreased.

[0088] (9) A high-voltage circuit unit 73 according to a ninth aspect is the high-voltage circuit unit 73 of (8), wherein the control unit 206 further has a switching unit 224 that switches the rotation direction of the heat dissipation fan 211, and the switching unit 224 is configured to be able to switch between a reverse mode in which the heat dissipation fan 211 is operated for a certain period of time to expel air from the cooling flow path 300, and a normal mode in which the heat dissipation fan 211 is operated to take in air into the cooling flow path 300.

[0089] According to the above configuration, by operating the heat dissipation fan 211 in reverse mode for a certain period of time, foreign matter in the cooling flow path 300 can be expelled to the outside.

[0090] (10) The high-voltage circuit unit 73 according to the tenth aspect is the high-voltage circuit unit 73 of (9), in which the switching unit 224 drives the heat dissipation fan 211 in the normal mode for a certain period of time and then drives it in the reverse mode for another certain period of time, and then determines the rotation direction of the heat dissipation fan 211 as an initial setting based on the relationship between the temperature of the heat sink 110 in the normal mode and the temperature of the heat sink 110 in the reverse mode.

[0091] According to the above configuration, the rotation direction of the heat dissipation fan 211 can be switched, so that the flow direction of the cooling air can be selectively determined regardless of which side of the vehicle width the high-voltage circuit unit 73 is placed on.

[0092] (11) A transport refrigeration machine 1 according to an eleventh aspect includes a high-voltage circuit unit 73 according to any one of the aspects (1) to (10) and a refrigeration cycle unit driven by the high-voltage circuit unit 73.

[0093] According to the above configuration, it is possible to provide a transport refrigeration machine 1 equipped with a high-voltage circuit unit 73 having higher cooling performance. [Explanation of symbols]

[0094] 1...Transport refrigeration machine 2...Battery unit 3...Electrical circuit system 4...Refrigeration cycle device 31...High-voltage circuit 32...Low-voltage circuit 33...High-voltage battery 34...Low-voltage battery 41...Compressor 42...Condenser 42a...First section 42b...Second section 43...Expansion valve 44...Evaporator 45...Condenser fan 45a...First fan 45b...Second fan 46...Evaporator fan 47...Receiver 48...Accumulator 49...Oil separator 52...Inverter 51...DC-DC converter 61...Main circuit 62...Communication circuit 63...Relay circuit 64...Cabin controller 71...Compressor unit 72...Condenser unit 73...High-voltage circuit unit 74...Low-voltage circuit unit 81...Top surface 82...Bottom surface 83...Side surface 84...Front surface 85...Rear surface 90...Transport vehicle 91...Vehicle body 92...Chassis 93...Wheels 94...Container 95...Cabin 94a...Front wall 96...Frame 100...Motor 110...Heat sink 111...Cooling plate 112...Fin L...Refrigerant line V...Freezer compartment 201...High voltage circuit main body 202...Casing 203...Fan box 204...Harness 205...Harness holding portion 206...Control portion 211...Heat dissipation fan 212...Box main body 213...Suction panel 221...Temperature acquisition portion 222...Determination portion 223...Adjustment portion 224...Switching portion 225...Memory portion 300...Cooling flow path 301...Constriction portion 302...Flow path main body portion 303...Bottom surface of recess 400...Temperature sensor 500...Computer 501...CPU 502...Main memory 503...Storage 504...Interface

Claims

1. A high-voltage circuit unit for driving a transport refrigeration machine mounted on a transport vehicle and having a refrigeration cycle device, a high-voltage circuit body having an inverter that converts power from the battery unit and supplies it to the refrigeration cycle device, and a DC converter that generates a DC current for driving auxiliary devices; a rectangular parallelepiped casing that houses the high-voltage circuit main body; a heat sink thermally connected to the inverter and the DC converter; a heat dissipation fan that pressurizes and sends air to the heat sink; Equipped with A high-voltage circuit unit in which a cooling flow path is formed on the back surface of the casing, the cooling flow path being recessed toward the front surface and extending horizontally, and the heat sink is arranged on one horizontal side of the cooling flow path.

2. 2. The high-voltage circuit unit according to claim 1, wherein the heat sink and the heat dissipation fan are disposed at positions offset upward in the casing.

3. 3. The high-voltage circuit unit according to claim 1, wherein the cooling flow path has a contraction section in which the cross-sectional area of ​​the flow path gradually decreases from an inlet side where the heat dissipation fan is disposed to a downstream side in the air blowing direction.

4. 3. The high-voltage circuit unit according to claim 1, wherein the casing further includes a harness holding portion disposed at a position different from the inlet within a plane in which the heat dissipation fan is disposed, as viewed from the inlet side of the cooling flow path.

5. 5. The high-voltage circuit unit according to claim 4, wherein the harness holding portion is provided on both of a pair of side surfaces of the casing.

6. 3. The high-voltage circuit unit according to claim 1, wherein the cooling passage extends in the same direction as the traveling direction of the transportation vehicle.

7. a temperature sensor for acquiring a temperature of the heat sink; a control unit that controls the operation of the heat dissipation fan based on the temperature acquired by the temperature sensor; The control unit a temperature acquisition unit that acquires the temperature from the temperature sensor; a determination unit that determines whether the temperature is higher or lower than a first threshold value that is lower than a derated temperature of the inverter and the DC converter; an adjusting unit that adjusts the rotation speed of the heat dissipation fan based on the output of the determining unit; and The high-voltage circuit unit according to claim 1 , wherein the adjustment unit adjusts the rotation speed of the heat dissipation fan to be higher when the determination unit determines that the temperature is higher than the first threshold value.

8. 8. The high-voltage circuit unit according to claim 7, wherein the adjustment unit drives the heat dissipation fan at the rotation speed adjusted in the increasing direction until the determination unit determines that the temperature has reached a second threshold value lower than the first threshold value.

9. The control unit further includes a switching unit that switches the rotation direction of the heat dissipation fan, The switching unit is a reverse mode in which the heat dissipation fan is operated for a certain period of time to discharge air from the cooling flow path; 9. The high-voltage circuit unit according to claim 8, wherein a switching mode is possible between a normal mode in which the heat dissipation fan is operated so as to take in air into the cooling flow path and a normal mode in which the heat dissipation fan is operated so as to take in air into the cooling flow path.

10. 10. The high-voltage circuit unit according to claim 9, wherein the switching unit drives the heat dissipation fan in the normal mode for a certain period of time and then drives the heat dissipation fan in the reverse mode for another certain period of time, and then determines the rotation direction of the heat dissipation fan as an initial setting based on the relationship between the temperature of the heat sink in the normal mode and the temperature of the heat sink in the reverse mode.

11. The high-voltage circuit unit according to claim 1 or 2; a refrigeration cycle unit driven by the high voltage circuit unit; A transport refrigeration machine comprising:

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