Patent Publication Number: US-2022231467-A1

Title: Wiring component with temperature sensor

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present patent application claims the priority of Japanese patent application No. 2021-005053 filed on Jan. 15, 2021, and the entire contents of Japanese patent application No. 2021-005053 are hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to a wiring component with temperature sensor that is a component having electric wires and a temperature sensor. 
     BACKGROUND ART 
     Conventionally, to prevent damage caused by, e.g., overheating of coil windings of an electric motor, temperature of an electric wire carrying a current supplied to the electric motor is detected by a temperature sensor, and when the detected temperature is not less than a predetermined value, the current supplied to the electric motor is stopped or reduced. 
     A temperature sensor described in Patent Literature 1 includes a heat-sensitive body such as a thermistor for detecting temperature of a measurement target object, a pair of leads respectively connected to a pair of electrodes of the heat-sensitive body, a first fixing member having a first recess and a second fixing member having a second recess, and the measurement target object is housed in a through-hole formed by a combination of the first recess and the second recess. The first fixing member and the second fixing member are made of a resin such as engineering plastic, and are joined to each other in a state in which the measurement target object is sandwiched therebetween. The heat-sensitive body is insert molded into the first fixing member and the pair of leads are respectively connected to a pair of wires inside the first fixing member. The pair of wires extend out of the first fixing member and are connected to a sensor measuring device, and temperature of the measurement target object can be detected by measuring a resistance value between the pair of wires using the sensor measuring device. The measurement target object is, e.g., a wiring component in a motor device. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: JP 2020-1536% A 
       
    
     SUMMARY OF INVENTION 
     For the temperature sensor described in Patent Literature 1, it is necessary to lead the pair of wires out of a cavity of a mold when molding the first fixing member. This work is difficult to automate, and when the work of leading out these wires is performed manually, a long working time is required, which leads to an increase in manufacturing cost. 
     Therefore, it is an object of the invention to provide a wiring component with temperature sensor that facilitates automation and can reduce the cost. 
     For solving the above problem, one aspect of the present invention provides a wiring component with temperature sensor, comprising:
         an electric wire;   a temperature sensor comprising a detection unit configured to detect temperature of the electric wire and a plurality of lead wires; and   a plurality of connector pins respectively connected to the plurality of lead wires,   wherein the electric wire, the temperature sensor and the plurality of connector pins are collectively held by a holder comprising a resin, and   wherein the holder comprises a connector housing member configured to hold the plurality of connector pins and a molded resin member covering a portion of the connector housing member       

     THE EFFECT OF THE INVENTION 
     According to the present invention, it is possible to provide a wiring component with temperature sensor that facilitates automation and can reduce the cost. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view showing a wiring component with temperature sensor in an embodiment of the present invention and another connector. 
         FIG. 2  is a perspective view showing constituent elements of the wiring component with temperature sensor. 
         FIG. 3  is a perspective view showing the wiring component with temperature sensor, in which a molded resin member is indicated by phantom lines and the inside thereof is indicated by solid lines. 
         FIGS. 4A and 4B  are cross sectional views showing the wiring component with temperature sensor. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 
       FIG. 1  is a perspective view showing a wiring component with temperature sensor in an embodiment of the invention and another connector to be fitted to a connector portion of the wiring component with temperature sensor.  FIG. 2  is a perspective view showing each constituent element of the wiring component with temperature sensor.  FIG. 3  is a perspective view showing the wiring component with temperature sensor, in which a molded resin member is indicated by phantom lines and the inside thereof is indicated by solid lines.  FIGS. 4A and 4B  are cross sectional views showing the wiring component with temperature sensor. 
     A wiring component with temperature sensor  1  (i.e., temperature sensor-including wiring component  1 ) includes plural electric wires  21 ,  22 , a temperature sensor  3  (see  FIG. 4 ) having a detection unit  30  to detect temperature of the electric wires  21 ,  22  and plural lead wires  31 ,  32 , plural connector pin  41 ,  42  respectively connected to the plural lead wires  31 ,  32 , and a resin holder  5  collectively holding them. The plural electric wires  21 ,  22  extend linearly and parallel to each other inside the holder  5 . In  FIGS. 1 to 4 , only a portion of the electric wires  21 ,  22  in a longitudinal direction is shown. 
     The holder  5  is provided with a connector portion  11  to which another connector  9  is fitted. In the other connector  9 , plural connector terminals (not shown) are arranged in a resin connector housing  90  and signal lines  91 ,  92  respectively connected to the plural connector terminals extend out of the connector housing  90 . The connector housing  90  integrally has a base portion  901  and a protruding portion  902 , and the protruding portion  902  is housed in the holder  5  when the other connector  9  is fitted to the connector portion  11  of the wiring component with temperature sensor  1 . The signal lines  91 ,  92  are insulated wires in each of which a stranded wire having excellent flexibility is covered with an insulator. 
     The plural electric wires  21 ,  22  are solid wires coated with enamel and are used to, e.g., supply a drive current to coils of a motor that generates mechanical movement by electromagnetic action, such as electric motor or electromagnetic actuator. Although two electric wires  21 ,  22  are held by the holder  5  in the present embodiment, the number of the electric wires held by the holder  5  may be one or not less than three. In addition, the electric wires  21 ,  22  are round wires having a circular cross-sectional shape and the same diameter in the present embodiment, but it is not limited thereto. The electric wires  21 ,  22  may be, e.g., rectangular wires having a rectangular cross-sectional shape. 
     The temperature sensor  3  is, e.g., a thermistor whose electrical resistance changes depending on temperature. In the detection unit  30 , a temperature detection element is sealed with a sealing material such as glass and the lead wires  31 ,  32  extending inside and outside the sealing material are connected to electrodes of the temperature detection element. The temperature sensor  3  is not limited to the thermistor, and, e.g., a thermocouple may be used. 
     The lead wires  31 ,  32  of the temperature sensor  3  are respectively connected to end portions of the connector pins  41 ,  42  on one side in the longitudinal direction by, e.g., welding. Alternatively, the lead wires  31 ,  32  of the temperature sensor  3  may be connected to the connector pins  41 ,  42  by, e.g., soldering. 
     The holder  5  includes a connector housing member  8  that holds the connector pins  41 ,  42  and constitutes the connector portion  11 , and a portion of the connector housing member  8  is covered with a molded resin member  50  formed by molding. The holder  5  also has an electric wire holding member  6  to hold the electric wires  21 ,  22  and a sensor holding member  7  to hold the temperature sensor  3 , and the electric wire holding member  6  and the sensor holding member  7 , together with the connector housing member  8 , are integrated by the molded resin member  50 . Each of the electric wire holding member  6 , the sensor holding member  7  and the connector housing member  8  is formed of a resin and is pre-molded before the molded resin member  50  is molded. 
     The molded resin member  50  covers at least a portion of each of the electric wire holding member  6 , the sensor holding member  7  and the connector housing member  8 . The electric wire holding member  6 , the sensor holding member  7  and the connector housing member  8  are integrated by the molded resin member  50  and constitute, together with the molded resin member  50 , the holder  5 . 
     The electric wires  21 ,  22  are held by the electric wire holding member  6  at a distance from each other along a predetermined arrangement direction D 1  (see  FIG. 4A ). The arrangement direction D 1  is a direction perpendicular to a wire extending direction D 2  (see  FIG. 4B ) which is coincident with the longitudinal direction of a portion of the electric wires  21 ,  22  held by the electric wire holding member  6 , and the distance between the electric wires  21 ,  22  in the arrangement direction D 1  is, e.g., smaller than a diameter of the electric wires  21 ,  22 . 
     The electric wire holding member  6  has a substantially rectangular parallelepiped shape, on which a first recessed groove  61  to house a portion of the electric wire  21 , which is one of the plural electric wires  21 ,  22 , in a circumferential direction and a second recessed groove  62  to house a portion of the other electric wire  22  in the circumferential direction are formed in parallel to each other. The electric wire holding member  6  is configured such that a front surface  6   a  having the first recessed groove  61  and a back surface  6   b  having the second recessed groove  62  are rectangular flat surfaces perpendicular to the arrangement direction D 1  of the electric wires  21 ,  22 , and the first and second recessed grooves  61 ,  62  extend along a direction of the long side of these surfaces. 
     A housing hole  63  opening on a side surface  6   c  between the front surface  6   a  and the back surface  6   b  is also formed on the electric wire holding member  6 . The housing hole  63  is a hole configured to house the sensor holding member  7  and opens in a direction D 3  that is perpendicular to the arrangement direction D 1  of the electric wires  21 ,  22  and the wire extending direction D 2  (hereinafter, this direction is referred to as a perpendicular direction D 3 ). 
     The housing hole  63  is formed so that at least a portion thereof is located between the one electric wire  21  and the other electric wire  22  when the electric wires  21 ,  22  held by the electric wire holding member  6  are viewed in the perpendicular direction D 3 . In the present embodiment, the housing hole  63  and a thin portion  64 , which is a portion of the electric wire holding member  6  located between the deepest portion of the first recessed groove  61  and the deepest portion of the second recessed groove  62 , are arranged side-by-side in the perpendicular direction D 3 . As a result, the detection unit  30  of the temperature sensor  3  can be arranged at a position where heat generated by a current flowing through the electric wires  21 ,  22  is easily transmitted, an increase in size of the electric wire holding member  6  can be suppressed, and the electric wire holding member  6  can be formed small in size. In this regard, the housing hole  63  may be formed to extend from the side surface  6   c  to a position between the deepest portion of the first recessed groove  61  and the deepest portion of the second recessed groove  62 , and the temperature sensor  3  may be arranged so that the detection unit  30  is located between the one electric wire  21  and the other electric wire  22 . 
     The sensor holding member  7  houses the temperature sensor  3  and end portions of the connector pins  41 ,  42  respectively connected to the lead wires  31 ,  32  of the temperature sensor  3 . The detection unit  30  of the temperature sensor  3  is fixed inside the sensor holding member  7 . The temperature sensor  3  is insert molded so as to be entirely covered with the sensor holding member  7  in the present embodiment, but the lead wires  31 ,  32  and the connector pins  41 ,  42  may be connected outside the sensor holding member  7 . The sensor holding member  7  may have a box shape in which the temperature sensor  3  is housed. 
     The electric wire holding member  6  and the sensor holding member  7  are integrated by the molded resin member  50  in a state in which the sensor holding member  7  is housed in the housing hole  63  of the electric wire holding member  6 . An inside dimension of the housing hole  63  is slightly larger than an outside dimension of the sensor holding member  7 . 
     When the sensor holding member  7  is inserted into the deepest part of the housing hole  63 , i.e., when a front end face  7   a  of the sensor holding member  7  is in contact with a bottom surface  63   a  of the housing hole  63  as shown in  FIG. 4B , a portion of the sensor holding member  7  protrudes outside the housing hole  63  from the side surface  6   c  of the electric wire holding member  6 . As a result, when molding the molded resin member  50 , it can be confirmed by worker&#39;s visual check or by analyzing an image taken by a camera that the sensor holding member  7  has been inserted into the deepest part of the housing hole  63 . 
     The connector housing member  8  has a bottomed cylindrical shape having a bore  80  to house the protruding portion  902  of the other connector  9 , and integrally has a cylindrical portion  81  and a bottom portion  82 . The connector pins  41 ,  42  are press-fitted into through-holes  821 ,  822  formed on the bottom portion  82 , and other end portions of the connector pins  41 ,  42  in the longitudinal direction on the opposite side to the end portions connected to the temperature sensor  3  protrude inside the bore  80 . Alternatively, the connector pins  41 ,  42  may be insert molded into the connector housing member  8 . 
     The connector pins  41 ,  42  do not protrude outside from the bore  80  of the connector housing member  8  and are connected to the connector terminals of the other connector  9  inside the bore  80 . By covering a portion of the connector housing member  8  with the molded resin member  50  and housing the entire connector pins  41 ,  42  in the holder  5  as described above, it is possible to suppress bending of the connector pins  41 ,  42  caused by, e.g., contact with the connector housing  90  during work of fitting to the other connector  9 , etc., as compared to when the connector pins  41 ,  42  partially protrude outside the holder  5 . 
     The molded resin member  50  is formed by injecting a molten resin into a cavity of a mold in a state in which the electric wire holding member  6 , the sensor holding member  7  and the connector housing member  8  are arranged in the mold as indicated by the solid lines in  FIG. 3 . Portions of the electric wires  21 ,  22  in the circumferential direction, which are not housed in the first recessed groove  61  and the second recessed groove  62 , are completely covered with the molded resin member  50 . That is, in the vicinity of the temperature sensor  3 , the electric wires  21 ,  22  are held by the holder  5  entirely in the circumferential direction. The molded resin member  50  may be, or may not be, fused to the electric wire holding member  6 , the sensor holding member  7  and the connector housing member  8  by heat during injection molding. 
     When the other connector  9  is fitted into the connector portion  11  of the wiring component with temperature sensor  1 , the lead wires  31 ,  32  of the temperature sensor  3  are electrically connected to the signal lines  91 ,  92  via the connector pins  41 ,  42  and the terminals of the other connector  9 . The signal lines  91 ,  92  are connected to, e.g., a control device that controls an electric motor operated by a current flowing through the electric wires  21 ,  22 , and when temperature detected by the temperature sensor  3  becomes not less than a predetermined value, the control device stops or suppresses the current flowing through the electric wires  21 ,  22 . 
     As a resin material for the electric wire holding member  6  and the sensor holding member  7 , it is desirable to use a highly thermally-conductive resin material having a higher thermal conductivity than the molded resin member  50 . By forming the electric wire holding member  6  and the sensor holding member  7  using a highly thermally-conductive resin material, it is possible to detect temperature of the electric wires  21 ,  22  more accurately. 
     Effects of the Embodiment 
     In the embodiment of the invention described above, when molding the molded resin member  50  using a mold, it is not necessary to lead plural signal lines connected to the lead wires  31 ,  32  of the temperature sensor  3  out of a cavity of this mold. Thus, it is easy to manufacture the wiring component with temperature sensor  1  by an automated manufacturing equipment and the cost can be reduced. 
     In addition, in the present embodiment, since the electric wires  21 ,  22  and the temperature sensor  3  are collectively held by the holder  5 , a distance between the electric wires  21 ,  22  and the detection unit  30  of the temperature sensor  3  can be maintained constant in accordance with the design value and it is possible to increase accuracy of detecting temperature of the electric wires  21 ,  22 . 
     Summary of the Embodiment 
     Technical ideas understood from the embodiment will be described below citing the reference numerals, etc., used for the embodiment. However, each reference numeral described below is not intended to limit the constituent elements in the claims to the members, etc., specifically described in the embodiment. 
     A wiring component with temperature sensor ( 1 ), comprising: an electric wire ( 21 ,  22 ); a temperature sensor ( 3 ) comprising a detection unit ( 30 ) configured to detect temperature of the electric wire ( 21 ,  22 ) and a plurality of lead wires ( 31 ,  32 ); and a plurality of connector pins ( 41 ,  42 ) respectively connected to the plurality of lead wires ( 31 ,  32 ), wherein the electric wire ( 21 ,  22 ), the temperature sensor ( 3 ) and the plurality of connector pins ( 41 ,  42 ) are collectively held by a holder ( 5 ) comprising a resin, and wherein the holder ( 5 ) comprises a connector housing member ( 8 ) configured to hold the plurality of connector pins ( 41 ,  42 ) and a molded resin member ( 50 ) covering a portion of the connector housing member ( 8 ). 
     The wiring component with temperature sensor ( 1 ) described in [ 1 ], wherein the holder ( 5 ) comprises an electric wire holding member ( 6 ) configured to hold the electric wire ( 21 ,  22 ) and a sensor holding member ( 7 ) configured to hold the temperature sensor ( 3 ), and wherein the electric wire holding member ( 6 ) and the sensor holding member ( 7 ), together with the connector housing member ( 8 ), are integrated by the molded resin member ( 50 ). 
     The wiring component with temperature sensor ( 1 ) described in [ 2 ], wherein a housing hole ( 63 ) configured to house the sensor holding member ( 7 ) is formed on the electric wire holding member ( 6 ), and wherein the electric wire holding member ( 6 ) and the sensor holding member ( 7 ) are integrated in a state in which the sensor holding member ( 7 ) is housed in the housing hole ( 63 ). 
     The wiring component with temperature sensor ( 1 ) described in [3], wherein a plurality of the electric wires ( 21 ,  22 ) are held by the electric wire holding member ( 6 ) so as to be in parallel and at a distance from each other along a predetermined arrangement direction (D 1 ), and wherein the housing hole ( 63 ) is formed between the electric wires ( 21 ,  22 ) when the plurality of the electric wires ( 21 ,  22 ) are viewed in a direction (D 3 ) that is perpendicular to the arrangement direction (D 1 ) and a longitudinal direction (D 2 ) of the electric wires. 
     Although the embodiment of the invention has been described, the invention according to claims is not to be limited to the embodiment described above. Further, please note that not all combinations of the features described in the embodiment are necessary to solve the problem of the invention.