Patent Publication Number: US-2023150335-A1

Title: Air compressor for vehicle and method for controlling temperature of the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims priority to Korean Patent Application No. 10-2021-0158104 filed on Nov. 17, 2021 the entire contents of which is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE PRESENT DISCLOSURE 
     Field of the Present Disclosure 
     The present disclosure relates to an air compressor for a vehicle, such as a large electric vehicle, capable of appropriately maintaining an internal temperature and a discharge temperature thereof even in a cold environment, and a method for controlling a temperature of the same. 
     Description of Related Art 
     For example, a large electric vehicle such as a bus or truck provided with a fuel cell system is driven by operating a driving motor with electricity produced by a fuel cell stack. That is, the large electric vehicle is driven only by driving force of the driving motor with no engine. Accordingly, as an air compressor mounted on the large electric vehicle, an electric air compressor is employed. 
     Such an electric air compressor compresses and discharges air, for example, through rotation motion of a motor and a crankshaft therein, which accompany reciprocating motions (for compression and expansion) of a plurality of pistons connected to the crankshaft and provided in a plurality of cylinders. When air is consumed by a pneumatic system such as a braking device or a suspension device, if a pressure in an air tank of the vehicle decreases to such an extent that the air tank needs to be charged, the electric air compressor may be operated to compress and discharge air and supply the air to the air tank. 
     When the present process is repeated, temperatures of the motor and the cylinders of the air compressor continuously rise. When the temperatures of the motor and cylinders exceed appropriate temperatures thereof, a lubrication function deteriorates in the cylinders and oil carbide is discharged, causing problems such as a decrease in performance of the pneumatic system, a reduction in efficiency, and deteriorations of portions. 
     To prevent these problems, it is necessary to cool the cylinders of the electric air compressor. As an exemplary embodiment of the present disclosure, an air cooler, in which a cooling fan is provided in each cylinder head to cool the cylinder, may be employed. Thus, when power is supplied to the vehicle, power is applied to a motor of the cooling fan to operate the cooling fan, cooling each of the cylinders. In other words, the cooling fan may be driven to cool the cylinder regardless of whether the air compressor is in operation. 
     The air cooler is advantageous in that a complicated configuration of a cooling circuit may be omitted. However, the air cooler may rapidly reduce a temperature of air discharged from the air compressor due to cold weather or according to the performance of the cooling fan. As a result, moisture may be generated in a pipeline continuing from a discharge pipe of the air compressor to the pneumatic system, or moisture and oil generated in the cylinder are mixed and an emulsion including a high viscosity is generated and frozen. 
     Such frozen emulsion may affect the pneumatic system, the braking device using pneumatic pressure, braking performance may deteriorate or be lost, leading to a vehicle safety problem in which braking is impossible. 
     The information included in this Background of the present disclosure section is only for enhancement of understanding of the general background of the present disclosure and may not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
     BRIEF SUMMARY 
     Various aspects of the present disclosure are directed to providing an air compressor apparatus for a vehicle configured for appropriately maintaining an internal temperature and a discharge temperature thereof even in a cold environment, and a method for controlling a temperature of the same. 
     According to an aspect of the present disclosure, an air compressor apparatus for a vehicle may include: a compressor body driven by a first motor; a support bracket supporting the compressor body and configured to be coupled to the vehicle; and a heat exchanger provided on one side of the support bracket, and configured for raising a temperature of external air to generate heated air and provide the heated air to the compressor body. 
     The compressor body may include a cylinder and a cooling fan provided on the cylinder to cool the cylinder, and the cooling fan may include a second motor. 
     Cooled air from the cooling fan may be transferred to an external peripheral surface of the cylinder and an external surface of the compressor body. 
     The heat exchanger may have a flow path formed for a coolant to flow therethrough, the heat exchanger may include at least one blowing fan supplied with power to rotate, and the at least one blowing fan may include a third motor. 
     The heat exchanger may also serve as an electric radiator cooling a power electric (PE) module of the vehicle. 
     The heated air from the heat exchanger may be supplied onto an external surface of the compressor body by the at least one blowing fan. 
     The compressor body may further include a temperature detector measuring a temperature of the first motor. 
     The air compressor apparatus may further include a control unit controlling the at least one blowing fan of the heat exchanger and the cooling fan of the compressor body to be selectively operated according to a detection signal received from the temperature detector. 
     The control unit may be electrically connected to the temperature detector via an inverter controller, and the control unit and the inverter controller may be connected to each other through a communications link. 
     The heat exchanger may be provided to face the outside of the vehicle on the support bracket. 
     According to another aspect of the present disclosure, a method for controlling a temperature of the above-described air compressor apparatus may include: monitoring a temperature of the first motor in the compressor body, when the compressor body is in operation; providing the heated air generated by the heat exchanger to the compressor body, when the temperature of the first motor is lower than a first temperature; and cooling the compressor body, when the temperature of the first motor is higher than a second temperature, wherein the second temperature is higher than the first temperature. 
     The method may further include determining whether or not the compressor body is in operation. 
     The providing of the heated air to the compressor body may be performed by operating the third motor to drive the at least one blowing fan. 
     The cooling of the compressor body may be performed by operating the second motor to drive the cooling fan. 
     The method may further include, after the cooling of the compressor body, stopping the operation of the at least one blowing fan and the cooling fan when the temperature of the first motor becomes higher than or equal to the first temperature and lower than a third temperature, wherein the third temperature may be higher than the first temperature and lower than the second temperature. 
     The method may further include, after the monitoring of the temperature of the first motor: comparing the temperature of the first motor with a third temperature when the temperature of the first motor is higher than or equal to the first temperature and lower than or equal to the second temperature; cooling the compressor body when the temperature of the first motor is higher than or equal to the third temperature; and stopping the operation of the at least one blowing fan and the cooling fan when the temperature of the first motor is lower than the third temperature, wherein the third temperature is higher than the first temperature and lower than the second temperature. 
     The methods and apparatuses of the present disclosure have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a view exemplarily illustrating an air compressor for a vehicle according to an exemplary embodiment of the present disclosure; 
         FIG.  2    is an exploded perspective view of  FIG.  1   : 
         FIG.  3    is a view exemplarily illustrating the air compressor for a vehicle according to an exemplary embodiment of the present disclosure in a mounted state on the vehicle; 
         FIG.  4    is a view exemplarily illustrating a blowing fan in an operating state in the air compressor for a vehicle according to an exemplary embodiment of the present disclosure; 
         FIG.  5    illustrates a temperature field of the vehicle to which the air compressor for a vehicle according to an exemplary embodiment of the present disclosure is applied: 
         FIG.  6    is a schematic block diagram illustrating an air management system of the vehicle to which the air compressor for a vehicle according to an exemplary embodiment of the present disclosure is applied; and 
         FIG.  7    is a flowchart illustrating a method for controlling a temperature of the air compressor for a vehicle according to an exemplary embodiment of the present disclosure. 
     
    
    
     It may be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the present disclosure. The specific design features of the present disclosure as included herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particularly intended application and use environment. 
     In the figures, reference numbers refer to the same or equivalent parts of the present disclosure throughout the several figures of the drawing. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments of the present disclosure(s), examples of which are illustrated in the accompanying drawings and described below. While the present disclosure(s) will be described in conjunction with exemplary embodiments of the present disclosure, it will be understood that the present description is not intended to limit the present disclosure(s) to those exemplary embodiments of the present disclosure. On the other hand, the present disclosure(s) is/are intended to cover not only the exemplary embodiments of the present disclosure, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the present disclosure as defined by the appended claims. 
     Hereinafter, various exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. Regarding the reference numerals assigned to the components in the drawings, it should be noted that the same components will be denoted by the same reference numerals although they are shown in different drawings. 
     In the present specification, a vehicle refers to any type of vehicle that moves a subject such as a person, an animal, or a thing from a departure point to a destination point. Such a vehicle is not limited to a vehicle traveling on roads or tracks. 
     In the present specification, the present disclosure is described by taking a large electric vehicle as an example for convenience of explanation, but the present disclosure is not necessarily limited thereto. 
     In addition, the terms “first”, “second”, and the like may be used to describe various components, but these components are not limited in order, size, location, or importance by the terms “first”. “second”, and the like, and are used only for distinguishing one component from another component. 
       FIG.  1    is a view exemplarily illustrating an air compressor for a vehicle according to an exemplary embodiment of the present disclosure, and  FIG.  2    is an exploded perspective view of  FIG.  1   . 
     As illustrated in  FIG.  1    and  FIG.  2   , the air compressor for a vehicle according to an exemplary embodiment of the present disclosure may include a compressor body  10 , a support bracket  20 , and a heat exchanger  30 . 
     The compressor body  10  is an electric air compressor including a first motor  13  (see  FIG.  6   ) operating based on an electric signal. A crankshaft provided in the compressor body may be connected to the first motor to drive at least one piston in at least one cylinder  11 . Here, the first motor may be built into the compressor body. 
     In the compressor body  10 , when the first motor  13  is driven, the crankshaft connected to the first motor may be forcibly rotated so that the piston provided in each cylinder  11  reciprocates (for compression and expansion). 
     During a compression stroke of the piston, external air may be provided into the cylinder  11  to become compressed air. Accordingly, during an expansion stroke of the piston, the compressed air may be discharged out of the cylinder through a discharge pipe  17  of a cylinder head  12 . 
     The compressor body  10  may further include a plurality of cooling fans  15  provided on the cylinder heads  12  of the respective cylinders  11  to cool the cylinder heads and the cylinders. Each of the cooling fans may include a second motor  16  (see  FIG.  6   ) which is integrally formed therewith. 
     Cold air from the cooling fan  15  may prevent the cylinder from being overheated by cooling the cylinder head  12  and the cylinder  11  while passing through external peripheral surfaces thereof. Furthermore, cold air discharged from the plurality of cooling fans may be evenly transferred to an external surface of the compressor body  10  so that the compressor body and components inside the compressor body are uniformly cooled, maximizing efficiency in cooling the compressor body. 
     Furthermore, the compressor body  10  may further include a temperature detector  14  (see  FIG.  6   ) measuring an internal temperature thereof, more specifically a temperature of the first motor  13 . 
     The temperature detector  14  may be provided on the first motor  13  in the compressor body  10  to detect a temperature of the first motor and output a detection signal to an inverter controller  42  (see  FIG.  6   ), which will be described later. 
     In the air compressor for a vehicle according to an exemplary embodiment of the present disclosure, because the rotation motion of the first motor  13  built in the compressor body  10  enables the reciprocating motion of the piston in the cylinder  11  so that air is compressed, an internal temperature of the cylinder and a discharge temperature of the compressor body may be controlled simultaneously by measuring and controlling a temperature of the first motor. 
     The support bracket  20  may be formed in a frame structure including an approximately hexahedral shape. For example, the support bracket may be formed by coupling a plurality of horizontal members, vertical members, and pillar members which are formed separately, but is not necessarily limited thereto, and may be integrally formed. 
     The support bracket  20  may be provided and mounted on a vehicle body  1 , for example, so that a front surface of the heat exchanger  30  faces the side of the vehicle. However, the position at which the support bracket is mounted and the arrangement relationship of the support bracket in the air compressor are not necessarily limited thereto, and the position at which the support bracket is mounted may be changed to another position of the vehicle body. 
     The compressor body  10  may be accommodated inside the support bracket  20 , and the heat exchanger  30  may be mounted on one external surface of the support bracket. In the instant case, the heat exchanger is provided to face the outside of the vehicle on the support bracket coupled to the vehicle body  1 , while the compressor body is provided adjacent to the interior of the vehicle. 
     The support bracket  20  may be coupled to the vehicle body  1  by bolting, and similarly, the compressor body  10  and the heat exchanger  30  may be coupled to the support bracket by bolting. The bolting-based coupling enables stable assembling and easy separation, improving the assemblability and productivity of the vehicle and reducing a time and an effort required for maintenance or replacement. 
     Furthermore, by modularizing the compressor body  10  and the heat exchanger  30  using the support bracket  20 , the compressor body  10  and the heat exchanger  30  may be easily mounted on a vehicle as a single module during an assembling process. Accordingly, it is possible to reduce the number of assembly processes and material costs in a vehicle manufacturing line, and implement an efficient layout of the vehicle. 
     The heat exchanger  30 , which is provided to cool a coolant flowing along a predetermined coolant circuit, has a flow path formed therein for the coolant to pass therethrough. The coolant may be water or an incompressible fluid. 
     The heat exchanger may be, for example, a radiator. Furthermore, the heat exchanger  30  may include at least one blowing fan  35  electrically connected to a battery  44  and supplied with power from the battery to rotate. The at least one blowing fan may include a third motor  36  (see  FIG.  6   ) which is integrally formed therewith. 
     The at least one blowing fan  35  may be configured and provided to be rotated by the third motor  36  supplied with power from the battery  44  so that a constant amount of external air is supplied to the heat exchanger  30 , and then hot air generated by the heat exchanger from the external air is transferred to the compressor body  10 . 
     When the vehicle is, for example, a large electric vehicle provided with a fuel cell system, such as a bus or a truck, the heat exchanger  30  may also serve as an electric radiator in which the coolant for cooling a power electric module passes. In other words, the electric radiator, which may be located in the front of the vehicle, may be provided in the middle portion of the side of the vehicle and integrated with the compressor body  10  of the present disclosure. 
     To the present end, the heat exchanger  30  may be connected to the power electric module including a driving motor, an inverter  43 , a decelerator, etc. In the vehicle provided with the fuel cell system, and the coolant heated in the power electric module may be cooled while passing through the inside of the heat exchanger. 
     The heat exchanger  30  and the power electric module may be connected to each other by a cooling hose, and the cooled coolant may be pumped through a pump and transferred to the power electric module. The pump may be an electric water pump driven by a motor supplied with power from the battery  44  to circulate the coolant. 
     When the heat exchanger  30  is further configured as an electric radiator as described above, an operation of the pump may be controlled depending on a temperature of the coolant. A rise in temperature of the power electric module, which is operated at all times after the vehicle is started, may cause a rise in temperature of the coolant after a certain time period elapses from the start of the vehicle. Accordingly, the pump may be operated, and the heat exchange function of the heat exchanger may be continuously performed using the circulating coolant after the start of the vehicle. 
     However, the application example of the heat exchanger  30  is not necessarily limited thereto, and the heat exchanger  30  may be applied as a radiator of a coolant circuit for cooling another component in the vehicle. In the instant case, the radiator may be operated by separately controlling a pump of the coolant circuit if necessary. 
     Meanwhile, the external air flowing toward the heat exchanger  30  and passing in contact with the heat exchanger may exchange heat with the coolant passing through the inside of the heat exchanger to cool the coolant, and at the same time, a temperature of the external air may be raised. The heated air, that is, hot air, may be transferred to the external surface of the compressor body  10 , which is provided adjacent to the heat exchanger and modularized with the heat exchanger, by a blowing fan  35 . 
     The air compressor for a vehicle according to an exemplary embodiment of the present disclosure may further include a control unit  40  (see  FIG.  6   ) controlling the at least one blowing fan  35  of the heat exchanger  30  and the cooling fan  15  of the compressor body  10  to be selectively operated according to a detection signal received from the temperature detector  14 . 
     The control unit  40  may be implemented using various kinds of processing devices such as a microprocessor in which a semiconductor chip or the like configured for performing various determinations or commands is embedded, and may control an overall operation of the air compressor for a vehicle according to an exemplary embodiment of the present disclosure. 
     For example, the control unit  40  may be incorporated into or used in combination with a vehicle control unit (VCU). 
     The control unit  40  may be electrically connected to the temperature detector  14  of the compressor body  10  to receive a detection signal. The control unit may be electrically connected to the temperature detector via the inverter controller  42 . The control unit and the inverter controller may be connected to each other through a communications link  41  (see  FIG.  6   ). 
     As the communications link  41 , for example, wireless communication such as a local area network using a controller area network (CAN) protocol may be employed, but the communications link  41  is not necessarily limited thereto, and wired communication or optical communication may be applied as the communications link  41 . 
     Furthermore, the control unit  40  may control the operation of the at least one blowing fan  35  of the heat exchanger  30  and the cooling fan  15  of the compressor body  10 , that is, the operation of the third motor  36  and the second motor  16 , according to a signal detected by the temperature detector  14 . 
     For example, when the temperature of the first motor  13  in the compressor body  10  is lower than a first temperature, the third motor  36  is operated to drive the at least one blowing fan  35  so that air heated by the heat exchanger  30  is provided to the compressor body. 
     When the temperature of the first motor  13  in the compressor body  10  is higher than a second temperature, the second motor  16  is operated to drive the cooling fan  15  to cool the compressor body. At the instant time, the operation of the third motor  36  and blowing fan  35  is stopped. 
     Thereafter, when the temperature of the first motor  13  in the compressor body  10  is higher than or equal to the first temperature and lower than a third temperature, the operation of the cooling fan  15  as well as the at least one blowing fan  35  is stopped. 
     Here, the aforementioned temperatures may have a relationship of the first temperature&lt;the third temperature&lt;the second temperature. For example, the first temperature may be 60° C., the third temperature may be 70° C., and the second temperature may be 80° C. 
       FIG.  3    is a view exemplarily illustrating the air compressor for a vehicle according to an exemplary embodiment of the present disclosure in a mounted state on the vehicle, and  FIG.  4    is a view exemplarily illustrating the at least one blowing fan in an operating state in the air compressor for a vehicle according to an exemplary embodiment of the present disclosure. 
     In  FIG.  3    and  FIG.  4   , it is shown that external air is heated and becomes hot air while passing through the heat exchanger  30 , and then the hot air flows toward the external peripheral surface of the compressor body  10 , particularly the cylinder  11 . In  FIG.  4   , the hot air is indicated by arrows. 
     In the air compressor for a vehicle according to an exemplary embodiment of the present disclosure, the operation of the cooling fan  15  of the compressor body  10  may be basically controlled so that cold air generated through the cooling fan cools the cylinder head  12  and the cylinder  11  while passing through the external peripheral surfaces thereof, preventing the cylinder from being overheated. 
     Furthermore, in the air compressor for a vehicle according to an exemplary embodiment of the present disclosure, the operation of the at least one blowing fan  35  together with the heat exchanger  30  may be controlled to provide hot air toward the compressor body  10 , increasing an amount of heat dissipation toward the compressor body, while the operation of the cooling fan  15  mounted on the cylinder head  12  of the compressor body is controlled to reduce an amount of cooling, appropriately maintaining an internal temperature of the compressor body. 
     As a result, the air compressor for a vehicle according to an exemplary embodiment of the present disclosure is capable of basically preventing deteriorations of portions due to oil carbide in a high-temperature environment, and also, raising an internal temperature and a discharge temperature of the compressor body  10  to prevent an excessive drop in an internal temperature of the compressor body  10  in a cold environment, suppressing generation of moisture. 
     Considering that moisture mixed with oil in the cylinder  11  generates emulsion, which is high-viscosity liquid, or is frozen in a pipeline and a pneumatic system, the internal temperature and the discharge temperature of the compressor body  10  may be appropriately raised to prevent generation of moisture and emulsion derived therefrom, protecting the pneumatic system associated with the air compressor and keeping the pneumatic system to have excellent performance. 
     Furthermore, in the air compressor for a vehicle according to an exemplary embodiment of the present disclosure, the heat exchanger  30  may be provided to face the outside of the vehicle on the support bracket  20  so that the heat exchanger acts as a barrier to prevent wet or cold external air from flowing directly into the compressor body  10 . 
     Thus, external air needs to pass through at least the heat exchanger  30  to reach the compressor body  10  in the support bracket  20 . This is advantageous in protecting the compressor body and preventing the inflow of moisture in a high-humidity environment such as during a rainy season. 
     Furthermore, in a cold environment, the heat exchanger  30  mounted on an external side of the support bracket  20  may act to block cold external air flowing toward the inside of the module. This may be helpful to some extent in preventing continuous contact between the cold external air and the compressor body  10 , which causes drops in temperature of the first motor  13  and the cylinder  11  in the compressor body. 
       FIG.  5    shows a temperature field on an X-Y plane of the vehicle when the at least one blowing fan  35  of the heat exchanger  30  is driven in the air compressor for a vehicle according to an exemplary embodiment of the present disclosure. 
     It may be seen that hot air is supplied from the heat exchanger  30  and heat is released from the hot air toward the compressor body  10 , raising a temperature of the compressor body. 
     When the temperature of the first motor  13  in the compressor body  10  drops to lower than the first temperature (e.g., 60° C.), the plurality of blowing fans  35  of the heat exchanger  30  may be driven to increase an amount of heat dissipation toward the compressor body inside the module, raising temperatures of the first motor and the cylinder  11  in the compressor body. 
     For example, when the coolant flows out of the heat exchanger  30  at a temperature of about 65° C. and at a rate of about 70 lpm (liter per minute), the amount of heat dissipation may be about 23 kW, and accordingly, an ambient temperature of the compressor body  10  may rise to temperature of external air +35° C. 
       FIG.  6    is a schematic block diagram illustrating an air management system of the vehicle to which the air compressor for a vehicle according to an exemplary embodiment of the present disclosure is applied. 
     As illustrated in  FIG.  6   , the air management system of the vehicle may include an air compressor  2  generating compressed air of the present disclosure, a separator cooler  3  acting as an oil separator separating moisture and oil from the compressed air having a high temperature and a high humidity, an air processing unit (APU)  4  acting as a dryer dehumidifying the compressed air, an air tank  5  filled with the compressed air, and a pneumatic system  6  into which the compressed air is introduced to use pneumatic pressure thereof. 
     Furthermore, the air management system may include a control unit  40  and an inverter controller  42 . The control unit and the inverter controller may be connected to each other by a communications link  41  using a CAN protocol. 
     The control unit  40  may control the air compressor  2  of the present disclosure together with the air management system. The inverter controller  42  may control the inverter  43  based on an electrical signal associated with the control unit, and may be electrically connected to the temperature detector  14  of the compressor body  10  to transmit a detection signal of the temperature sensor to the control unit. 
     When the vehicle is a large electric vehicle provided with a fuel cell system, such as a bus or a truck, the inverter  43  may convert DC electrical energy supplied from a fuel cell or DC electrical energy stored in the battery  44  into AC electrical energy having multiple phases, and provide the AC electrical energy to the driving motor. 
     Furthermore, the inverter  43  may be connected to the first motor  13  of the compressor body  10 , the second motor  16  of the cooling fan  15 , the third motor  36  of the at least one blowing fan  35 , the motor of the pump in the coolant circuit, or the like. 
     Although application of power to the at least one blowing fan  35  and the cooling fan  15  is not shown in  FIG.  6    for convenience of illustration, the at least one blowing fan and the cooling fan may be supplied with power, for example, from the battery  44  or from an auxiliary battery having a lower voltage than the battery. 
     Concerning the flow of compressed air, it is illustrated in  FIG.  6    that the air compressor  2  discharges air compressed to a predetermined system pressure, and the compressed air is stored in the air tank  5  after passing through the separator cooler  3  and the APU  4 . Accordingly, the compressed air is supplied to the pneumatic system  6  which requires pneumatic pressure, e.g., a braking device and a suspension device. 
     Conventionally, if a temperature of external air is about −10° C. in a cold environment, a discharge temperature of an air compressor becomes lower than the dew point due to the cold external air, and moisture such as condensed water is generated in a cylinder and a pipeline of the air compressor. The moisture is mixed with oil coming up from the cylinder of the air compressor, as a result generating emulsion. 
     If the emulsion is excessively accumulated or the emulsion is frozen because of the low temperature, the pneumatic system may not work properly, or its performance may deteriorate or get lost, leading to a vehicle safety problem. 
     For example, if the emulsion is excessively accumulated in the APU to such an extent that the APU is not able to discharge the emulsion, or if the emulsion is frozen in the APU, the performance of the APU may deteriorate. This may affect the braking device using pneumatic pressure downstream of the APU, leading to even a situation in which braking is impossible. 
     If the air compressor for a vehicle according to an exemplary embodiment of the present disclosure is applied, it is possible to prevent generation of not only moisture such as condensed water but also emulsion by operating the at least one blowing fan  35  together with the heat exchanger  30  in the above-mentioned cold environment to appropriately raise an internal temperature and a discharge temperature of the compressor body  10 . As a result, it is possible to protect the pneumatic system  6  of the vehicle and keep its performance. 
     To appropriately maintain the internal temperature and the discharge temperature of the compressor body  10  as described above, the air compressor for a vehicle according to an exemplary embodiment of the present disclosure may use temperature information of the first motor  13  in the compressor body. 
     In the present disclosure, because the compressor body  10  compresses air based on the reciprocating motion of the piston in the cylinder  11  caused by the rotation motion of the first motor  13 , there is a correlation between the temperature of the first motor and the internal temperature or the discharge temperature of the compressor body. Thus, by controlling the temperature of the first motor, the internal temperature and the discharge temperature of the compressor body may also be controlled simultaneously. 
     As illustrated in  FIG.  6   , the inverter controller  42  may collect the temperature information of the first motor  13  in the compressor body  10 , and transmit the collected information to the control unit  40  through the communications link  41  of the vehicle. The control unit may have a sequence for controlling the operation of the at least one blowing fan  35  of the heat exchanger  30  or the cooling fan  15  of the compressor body  10  according to a preset and programmable logic. 
       FIG.  7    is a flowchart illustrating a method for controlling a temperature of the air compressor for a vehicle according to an exemplary embodiment of the present disclosure. 
     The method for controlling a temperature of the air compressor for a vehicle according to an exemplary embodiment of the present disclosure may include: monitoring a temperature of the first motor  13  in the compressor body, when the compressor body  10  is in operation (S 20 ); providing hot air generated by the heat exchanger  30  to the compressor body, when the temperature of the first motor is lower than a first temperature (S 30 ); and cooling the compressor body, when the temperature of the first motor is higher than a second temperature (S 40 ). 
     First, the control unit  40  may check whether or not the compressor body is in operation (S 10 ). 
     When the compressor body  10  is in operation, the control unit  40  may continuously monitor a temperature of the first motor  13  in the compressor body through the temperature detector  14  of the compressor body via the inverter controller  42  (S 20 ). The monitoring of the temperature of the first motor may be continuously performed at least when the compressor body is in operation. 
     When the temperature of the first motor  13  is lower than a first temperature (e.g., 60° C.), the control unit  40  operates the at least one blowing fan  35  together with the heat exchanger  30  to generate hot air from external air, and transfers the hot air toward the compressor body  10  to raise a temperature of the compressor body (S 30 ). The raising of the temperature of the compressor body  10  may be performed until the temperature of the first motor  13  is higher than a second temperature (e.g., 80° C.). 
     When the temperature of the first motor  13  becomes higher than the second temperature by raising the temperature of the compressor body  10 , the control unit  40  stops the operation of at least the at least one blowing fan  35  and operates the cooling fan  15  mounted on the cylinder head  12  of the compressor body  10  to start cooling the compressor body (S 40 ). 
     When the temperature of the first motor  13  becomes lower than a third temperature (e.g., 70° C.) by cooling the compressor body  10 , the control unit  40  stops the operation of the cooling fan  15  together with the at least one blowing fan  35  (S 50 ). 
     Meanwhile, after the monitoring of the temperature of the first motor  13 , when the temperature of the first motor becomes higher than or equal to the first temperature and even higher than the second temperature, the control unit  40  may operate the cooling fan  15  to cool the compressor body  10  (S 40 ). 
     Furthermore, after the monitoring of the temperature of the first motor  13 , when the temperature of the first motor becomes higher than or equal to the first temperature and lower than or equal to the second temperature, the control unit  40  may compare the temperature of the first motor with the third temperature. At the instant time, when the temperature of the first motor is higher than or equal to the third temperature, the control unit  40  initiates cooling of the compressor body  10  (S 40 ). When the temperature of the first motor is lower than the third temperature, the control unit  40  may stop the operation of the cooling fan  15  together with the at least one blowing fan  35  (S 50 ). 
     When the temperature of the first motor  13  becomes lower than the first temperature back under the influence of the temperature of external air, the control unit  40  may operate the at least one blowing fan  35  to perform a control according to the same sequence as described above. 
     Reversely, when the temperature of the first motor  13  becomes higher than the second temperature under the influence of the temperature of external air, the control unit  40  may operate the cooling fan  15  to control a temperature of the air compressor. 
     As set forth above, according to an exemplary embodiment of the present disclosure, it is possible to appropriately manage an internal temperature and a discharge temperature of the air compressor in various environments by supplying hot air having a higher temperature than external air while blocking the inflow of the external air and controlling the fan of the compressor body and the fan of the heat exchanger together. 
     Furthermore, according to an exemplary embodiment of the present disclosure, it is possible to reduce condensed water and emulsion generated in a cold environment, preventing the condensed water and emulsion from being frozen, while a temperature is controlled by the fans in a high-temperature environment as well to prevent deteriorations of portions due to oil carbide. 
     Furthermore, according to an exemplary embodiment of the present disclosure, by modularizing the compressor body and the heat exchanger, one support bracket may be shared for structures for fixing two large-volume components. Thus, it is possible to efficiently lay out the components of the vehicle, and accordingly, costs may be reduced. 
     Furthermore, according to an exemplary embodiment of the present disclosure, because the air cooler is employed, the configuration of the device may be simplified as compared with that when a water cooler, which requires a coolant and a coolant circuit, is employed, and accordingly, the costs may be additionally reduced. 
     Last, according to an exemplary embodiment of the present disclosure, it is possible to prevent failures of several parts in various environments and increase their life span, resulting in an increase in reliability of the air management system of the vehicle, improving the commerciality of the vehicle. 
     Although the technical idea of the present disclosure has been described above with reference to exemplary embodiments of the present disclosure, various changes and modifications may include those skilled in the art without departing from the essential features of the present disclosure. 
     Furthermore, the term related to a control device such as “controller”, “control apparatus”, “control unit”. “control device”, “control module”, or “server”, etc refers to a hardware device including a memory and a processor configured to execute one or more steps interpreted as an algorithm structure. The memory stores algorithm steps, and the processor executes the algorithm steps to perform one or more processes of a method in accordance with various exemplary embodiments of the present disclosure. The control device according to exemplary embodiments of the present disclosure may be implemented through a nonvolatile memory configured to store algorithms for controlling operation of various components of a vehicle or data about software commands for executing the algorithms, and a processor configured to perform operation to be described above using the data stored in the memory. The memory and the processor may be individual chips. Alternatively, the memory and the processor may be integrated in a single chip. The processor may be implemented as one or more processors. The processor may include various logic circuits and operation circuits, may process data according to a program provided from the memory, and may generate a control signal according to the processing result. 
     The control device may be at least one microprocessor operated by a predetermined program which may include a series of commands for carrying out the method included in the aforementioned various exemplary embodiments of the present disclosure. 
     The aforementioned invention can also be embodied as computer readable codes on a computer readable recording medium. The computer readable recording medium is any data storage device that can store data which may be thereafter read by a computer system and store and execute program instructions which may be thereafter read by a computer system. Examples of the computer readable recording medium include Hard Disk Drive (HDD), solid state disk (SSD), silicon disk drive (SDD), read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy discs, optical data storage devices, etc and implementation as carrier waves (e.g., transmission over the Internet). Examples of the program instruction include machine language code such as those generated by a compiler, as well as high-level language code which may be executed by a computer using an interpreter or the like. 
     In various exemplary embodiments of the present disclosure, each operation described above may be performed by a control device, and the control device may be configured by a plurality of control devices, or an integrated single control device. 
     In various exemplary embodiments of the present disclosure, the control device may be implemented in a form of hardware or software, or may be implemented in a combination of hardware and software. 
     Furthermore, the terms such as “unit”, “module”, etc. Included in the specification mean units for processing at least one function or operation, which may be implemented by hardware, software, or a combination thereof. 
     For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner”. “outer”, “up”, “down”, “upwards”, “downwards”, “front”. “rear”, “back”, “inside”. “outside”, “inwardly”, “outwardly”, “interior”, “exterior”, “internal”. “external”, “forwards”, and “backwards” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. It will be further understood that the term “connect” or its derivatives refer both to direct and indirect connection. 
     The foregoing descriptions of predetermined exemplary embodiments of the present disclosure have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described to explain certain principles of the present disclosure and their practical application, to enable others skilled in the art to make and utilize various exemplary embodiments of the present disclosure, as well as various alternatives and modifications thereof. It is intended that the scope of the present disclosure be defined by the Claims appended hereto and their equivalents.