Patent Publication Number: US-2023147150-A1

Title: Electric valve and thermal management system

Description:
This disclosure is a national phase application of PCT international patent application PCT/CN2021/080344, filed on Mar. 12, 2021, which claims priority of Chinese Patent Application No. 202010175679.3, titled “ELECTRIC VALVE AND THERMAL MANAGEMENT SYSTEM”, filed with the China National Intellectual Property Administration on Mar. 13, 2020, which is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The present disclosure relates to an electric valve of a vehicle thermal management system and a thermal management system including the electric valve. 
     BACKGROUND 
     In order to improve a flow control accuracy of a working medium, an electric valve is provided in a vehicle thermal management system to adjust a flow of the working medium of the system. The electric valve controls the flow of the working medium by controlling superheat, the calculation to the superheat needs to obtain a passed pressure signal, and how to provide an electric valve which can obtain pressure signal at a lower cost is a technical problem. 
     SUMMARY 
     An object according to the present disclosure is to provide an electric valve capable of obtaining pressure signals at a low cost. 
     To achieve the above object, the following technical solutions are provided in the present disclosure: an electric valve, including a valve core, a valve seat, an electric control part and a driving part, where a first flow passage and a second flow passage are formed in the valve seat, and the electric valve is formed with a valve port, where the valve port is located between the first flow passage and the second flow passage, where the valve core can move relative to the valve port and change the opening degree of the valve port, the electric control part can control the driving part, and the driving part drives the valve core to move, where the electric valve further includes a pressure sensing unit, the pressure sensing unit is connected with the valve seat, and the pressure sensing unit can sense a pressure characteristic of the working medium in a detection flow passage and form a piezoelectric signal, where the electric control part includes an electric control board, the piezoelectric signal forms an electrical signal corresponding to the pressure characteristic by a conditioning circuit, and the electrical signal is used as a part of a signal for controlling the driving part. 
     A thermal management system, including an air conditioning system, where the air conditioning system includes an electric valve described above. 
     According to this technical solution, the piezoelectric signal is obtained through the pressure sensing unit, the electrical signal corresponding to the pressure signal is acquired by the piezoelectric signal through the conditioning circuit, and the electrical signal is used as a part of the signal for controlling the driving part, there is no need to separately provide a protective cover and a packaging structure of the pressure sensing unit, and the electric valve is used to protect the pressure sensing unit, which is beneficial to reduce the cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic block diagram of an embodiment of a thermal management system; 
         FIG.  2    is a structural perspective view of an electric valve from one direction; 
         FIG.  3    is a schematic top view of the electric valve of  FIG.  2   ; 
         FIG.  4    is a schematic cross-sectional view of the electric valve of  FIG.  3    taken along line A-A; 
         FIG.  5    is a partial structural exploded schematic diagram of the electric valve of  FIG.  1   ; 
         FIG.  6    is a schematic bottom view of an electric control part in  FIG.  5   ; 
         FIG.  7    is a schematic view of a combined three-dimensional structure of a valve seat, a temperature sensing unit, and a pressure sensing unit; 
         FIG.  8    is a schematic top view of the three-dimensional structure of  FIG.  7   ; 
         FIG.  9    is a schematic cross-sectional view of the electric valve of  FIG.  7    taken along line B-B; and 
         FIG.  10    is a block diagram of an embodiment of the electric valve. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The present disclosure is further illustrated hereinafter in conjunction with drawings and specific embodiments. 
     The thermal management system is mainly used in vehicles or household equipment, and the following is an explanation of the thermal management system for vehicles. The vehicle thermal management system at least includes an air conditioning system, and of course, with the disclosure of batteries in vehicles, the vehicle thermal management system may also include a battery cooling system. When the thermal management system works, the air conditioning system includes a refrigerant, which flows circularly, the battery cooling system includes a working medium that flows circularly, where the working medium can be water, oil, a mixture containing water or oil, a refrigerant, and the like. 
       FIG.  10    is a block diagram of an embodiment of the electric valve, where the electric valve includes a valve core, a valve seat, an electric control part and a driving part. A first flow passage and a second flow passage are formed on the valve seat, and the electric valve is provided with a valve port, which is located between the first flow passage and the second flow passage. The valve core can move relative to the valve port and change the opening degree of the valve port, the electric control part can control the driving part, and the driving part drives the valve core to move. In addition, the electric valve further includes a pressure sensing unit, the pressure sensing unit is connected with the valve seat, and the pressure sensing unit can sense a pressure characteristic of the working medium in the detection flow passage and form a piezoelectric signal, where the electric control part includes an electric control board, the piezoelectric signal forms an electrical signal corresponding to the pressure characteristic by means of a conditioning circuit, and the electrical signal is used as a part of a signal for controlling the driving part. According to this technical solution, the piezoelectric signal is obtained by the pressure sensing unit, the electrical signal corresponding to the pressure signal is acquired by the piezoelectric signal by the conditioning circuit, and the electrical signal is used as a part of the signal for controlling the driving part, and there is no need to separately provide a protective cover and packaging structure to the pressure sensing unit, and the electric valve is used to protect the pressure sensing unit, which is beneficial to reduce the cost. 
       FIG.  1    is a schematic diagram of an embodiment of the thermal management system, in this embodiment, the thermal management system includes an air conditioning system and a battery cooling system, and the air conditioning system includes a compressor  10 , a condenser  20 , an electric valve  30  and an evaporator  40 . When the air conditioning system works, the refrigerant is compressed into a high-temperature and high-pressure refrigerant by the compressor  10 , and the high-temperature and high-pressure refrigerant is cooled by the condenser  20  and becomes a normal-temperature and high-pressure refrigerant, and the normal-temperature and high-pressure refrigerant enters the evaporator  40  through the electric valve  30 . Since a pressure of the normal-temperature and high-pressure refrigerant decreases after passing through the electric valve  30 , the refrigerant can be vaporized and become a low-temperature refrigerant, the low-temperature refrigerant absorbs a large amount of heat in the evaporator  40  and returns to the compressor  10 . The battery cooling system includes a thermal management assembly  50  and a pump  60 , the refrigerant in the air conditioning system exchanges heat with the working medium of the battery cooling system in the thermal management assembly  50 , and the pump  60  provides power for the working medium of the battery cooling system to circulate. 
     Referring to  FIG.  2    to  FIG.  11   , the electric valve  30  includes a valve core  1 , a valve seat  2 , an electric control part  3  and a driving part  4 , and a first flow passage  21  and a second flow passage  22  are formed in the valve seat  2 , and the electric valve  30  has a valve port  20 . In this embodiment, the electric valve further includes a valve core seat  201 , and the valve port  20  is formed in the valve core seat  201 . Of course, in other embodiments, the valve port  20  can also be formed in the valve seat  2 ; where the valve port  20  is located between the first flow passage  21  and the second flow passage  22 , where the electric control part  3  can control the driving part  4 , which drives the valve core  1  to move, and the valve core  1  can move relative to the valve port  20  and change the opening degree of the valve port  20 . The electric control part  3  includes an electric control board  31 . In case that it is the control signal that an upper computer sends, the electric control board  31  is integrated with a conversion unit, which can convert the control signal into a driving signal and then enable the driving part  4  to drive the valve core  1  to move. In case that it is the system signal that the upper computer sends, the electric control board  31  is integrated with a micro-processing unit and a conversion unit, the micro-processing unit generates a control signal according to the system signal, and the conversion unit converts the control signal into a driving signal, and enables the driving unit  4  drive the valve core  1  to move. 
     In this embodiment, the electric control part  3  is provided with an input terminal  32 , the input terminal  32  supplies power to the electric control board  31  and receives the signal sent by the upper computer. In this embodiment, the driving part  4  includes a coil assembly  41  and a rotor assembly  42 , and the coil assembly  41  is electrically connected to the electric control board  31 , the electric control board  31  sends a driving signal to the coil assembly  41 , the coil assembly  41  generates an excitation magnetic field, and the rotor assembly  42  rotates under the action of the excitation magnetic field, the electric valve  30  further includes a transmission device, and the transmission device includes a nut  91  and a screw  92 , the nut  91  is fixed, the screw  92  is connected with the rotor assembly  42  and the valve core  1 , and the transmission device converts the rotation of the rotor assembly into an axial movement of the valve core  1 . Of course, the above driving part and transmission device are not limited to the implementation of this embodiment, and other structures may be used to achieve the same effect. 
     In this embodiment, the electric valve  30  further includes a pressure sensing unit  5  and a temperature sensing unit  6 , which are provided separately. Both the pressure sensing unit  5  and the temperature sensing unit  6  are in mechanical connected with the valve seat  2 . The pressure sensing unit  5  can sense a pressure characteristic of the working medium in a detection flow passage  23  and form a piezoelectric signal, and the piezoelectric signal forms an electrical signal corresponding to the pressure by a conditioning circuit, and the electrical signal is used as a part of a signal for controlling the driving part, the above conditioning circuit is integrated in the electronic control board  31 . The temperature sensing unit  6  extends into the detection flow passage  23 , and the temperature sensing unit  6  is able to sense the temperature characteristics of the working medium in the detection flow passage as a part of the signal for controlling the driving part. 
     In this embodiment, the temperature sensing unit  6  and the pressure sensing unit  5  are formed separately, so that one of them can be replaced according to the requirements of the system, the arrangement of which is more flexible, and the flexibility of selection and combination of sensing units can be increased, which is beneficial to further lowering the product cost. In this embodiment, the detection flow passage  23  is located in the valve seat  2 , and an extension direction of the detection flow passage  23  is the same with an extension direction of the first flow passage  21  and the second flow passage  22 . Of course, the detection flow passage  23  can also be located in the heat exchanger or other components in the system. 
     The valve seat  2  has a first mounting cavity  24  in which the pressure sensing unit  5  is located, and the valve device  30  further includes a first position-limiting part  71  and a first connecting piece  81 , where the pressure sensing unit  5  is position-limited with the valve seat  2  by the first position-limiting part  71 , and the electric control board  31  and the pressure sensing unit  5  are electrically connected by the first connecting piece  81 . In this embodiment, the pressure sensing unit  5  is a ceramic capacitive pressure sensor, but of course it can also be other pressure sensing units; the use of ceramic capacitive pressure sensors can effectively reduce costs. The first position-limiting part  71  includes a first clamping spring  711  and a first clamping groove  712  that is located in the valve seat  2 , and the first clamping spring  711  can be clamped in the first clamping groove  712 , where the first clamping spring  711  blocks an upper side of the pressure sensing unit  5 , and a first sealing ring  511  is provided between a lower side of the pressure sensing unit  5  and the valve seat  2 . Of course, the first position-limiting part is not limited to the first clamping spring and the first clamping groove, and may also be in the form of a threaded connection to limit the temperature sensing unit  5  and the valve seat  2 . 
     In this embodiment, the first connecting piece  81  is a spring, and the electric control board  31  is fixed to the first connecting piece  81 , where the pressure sensing unit  5  is provided with a first tin plate  51  and a first accommodating part  52 , and the first tin plate  51  is located at a bottom of the first accommodating part  52 , one end of the first connecting piece  81  is located in the first accommodating part  52  and is abutted with the first tin plate  51 . The first connecting piece  81  is elastically deformed after assembly, so that the first connecting piece  81  is abutted with the first tin plate  51  to ensure that the first connecting piece  81  is electrically connected to the pressure sensing unit  5 . An embodiment of fixing the electric control board  31  and the first connecting piece  81  by welding can be in that: the electric control board  31  forms the first insertion hole  311 , and one end of the first connecting piece  81  is inserted into the first insertion hole  311  and fixed by welding. In another embodiment, the electric control board  31  also has a tin plate, and the first connecting piece  81  is abutted with the tin plate and is fixed by welding. Of course, in other embodiments, one of the pressure sensing unit and the electric control board is fixedly connected with the first connecting piece, and the other of the pressure sensing unit and the electric control board is abutted with the first connecting piece, which facilitates the positioning and limiting of the first connecting piece. 
     The valve seat  2  is further provided with a second mounting cavity  25 , and the temperature sensing unit  6  is a thermistor and is located in the second mounting cavity  25 . The valve device further includes a second position-limiting part  72  and a second connecting piece  82 , where the temperature sensing unit  6  is position limited to the valve seat  2  by the second position-limiting part  72 , and the electric control board  31  and the temperature sensing unit  6  are electrically connected by the second connecting piece  82 . 
     In this embodiment, the second position-limiting part  72  includes a second clamping spring  721  and a second clamping groove  722  that is located in the valve seat  2 , where the second clamping spring  721  is located in an upper side of the temperature sensing unit  6 , and a stepped surface  61  of the temperature sensing unit  6  is abutted with the valve seat  2 , and a second sealing ring  611  is arranged between the stepped surface  61  and the valve seat  2 . The second connecting piece  82  is a spring, the electric control board  31  is fixed to the second connecting piece  82  by welding, and the temperature sensing unit  6  has a second tin plate  62  and a second accommodating part  63 , the second tin plate  62  is located at a bottom of the second accommodating part  63 , one end of the second connecting piece  82  is located in the second accommodating part  63  and is abutted with the second tin plate  62 , where the second connecting piece  82  is elastically deformed after assembly, so that the second connecting piece  82  is abutted with the first tin plate  62  to ensure that the second connecting piece  82  is electrically connected to the temperature sensing unit  6 ; the connection manner of the second connecting piece  82  with the electric control board  31  and the temperature sensing unit  6  is not limited to the connection manner in this embodiment. Of course, the second position-limiting part is not limited to the second clamping spring and the second clamping groove, and may also be in the form of a threaded connection to limit the temperature sensing unit and the valve seat. An embodiment of fixing the electric control board  31  with the second connecting piece  82  by welding can be in that: the electric control board  31  forms the second insertion hole  312 , and one end of the second connecting piece  82  is inserted into the second insertion hole  312  and fixed by welding. 
     The valve seat  2  further includes a valve core mounting cavity  27 , and the valve core  1  is located in the valve core mounting cavity  27 , the openings of the first mounting cavity  24 , the second mounting cavity  25  and the valve core mounting cavity  27  are arranged toward a same side of the valve seat  2 , and a throttling can be obtained at the valve port  20  by the electric valve. One of the first flow passage  21  and the second flow passage  22  is configured as upstream, and the other of the first flow passage  21  and the second flow passage  22  is configured as downstream, and the detection flow passage  23  is located in a downstream passage or the detection flow passage  23  is in communication with a downstream passage through a thermal management system. In other embodiments, the valve seat can also be a transfer piece or located in a heat exchanger. 
     It should be noted that, the above embodiments are only intended to illustrate the present disclosure and not to limit the technical solutions described in the present disclosure. Although the present specification has been described in detail with reference to the embodiments described above, it should be understood by those skilled in the art that, various modifications and equivalents can be made to the technical solutions of the present disclosure without departing from the spirit and scope of the present disclosure, all of which should be contained within the scope of the claims of the present disclosure.