Patent Publication Number: US-2007108188-A1

Title: Insulator for a PTC heater

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      The present application claims priority, under 35 U.S.C. § 119, to South Korean patent Application No. 10-2005-109229 filed Nov. 15, 2005, the contents of which are hereby incorporated by reference in their entirety.  
     FIELD OF INVENTION  
      The present invention relates to an insulator provided in a PTC rod assembly, and more particularly, to an insulator for a PTC heater comprising a pair of pieces to be removably coupled to an anode terminal.  
     BACKGROUND  
      Generally, vehicles include a heating apparatus for heating the interior of the vehicle. Such heating apparatuses can also use thermal energy from cooling water heated by the vehicle engine to remove moisture or frost from a windshield of the vehicle.  
      The cooling water of the heating apparatus flows through the engine after the engine is started and is heated over an extended period of time. Accordingly, there is a problem in that the driver and passengers are required to sit in the cold interior of the vehicle for a certain period of time after the engine is started.  
      To solve this and other problems, an apparatus for receiving a ceramic heating element, such as, for example, a PTC (Positive Temperature Coefficient) element has been suggested.  
       FIG. 1   a  is a perspective view of a conventional PTC rod assembly, and  FIG. 1   b  is an exploded perspective view of the PTC rod assembly shown in  FIG. 1   a.    
      As shown in  FIGS. 1   a,    1   b,  a conventional PTC rod assembly  1  comprises a first PTC rod  10  formed in an elongate channel shape with an open portion, a second PTC rod  20  coupled to the first PTC rod  10  to cover the open portion of the first PTC rod  10 , an anode terminal  40  positioned in the first PTC rod  10  and enclosed by an insulator  30  not to be in contact with the first PTC rod  10 , PTC elements  50  placed between one surface of the anode terminal  40  and the second PTC rod  20 , and heat transfer blocks  60  made of a material with high thermal conductivity and brought into contact with the other side surface of the anode terminal  40 .  
      Each of the PTC elements  50  is coupled such that one surface thereof is in contact with the anode terminal  40  and the other surface thereof is in contact with the second PTC rod  20  acting as a cathode terminal. The PTC elements generate heat when electric power is applied thereto. At this time, because the first PTC rod  10  and the second PTC rod  20  are coupled to be brought into contact with each other, not only the second PTC rod  20  but also the first PTC rod  10  acts as a cathode terminal.  
      Further, when the first and second PTC rods  10  and  20  are coupled to each other, enlarged portions  32  and  34  brought into close contact with inner surfaces of the first and second PTC rods  10  and  20  are formed at both ends of the insulator  30 . Accordingly, an inner space defined by the first and second PTC rods  10  and  20  is sealed by the enlarged portions  32  and  34 .  
      Such a conventional insulator  30  is manufactured by injection molding an insulation material around an insert (i.e., the anode terminal  40 ) to increase the strength of the insulator  30  and the adhesion thereof with the insert. That is, the insulator  30  is manufactured by an insert injection molding process, by preparing a mold, positioning the anode terminal  40  in the mold, and injection molding the insulator  30  around the anode terminal  40 . Thus, because the conventional insulator  30  is manufactured using a plurality of steps, there are disadvantages in that the manufacture is complicated and workability is deteriorated. In addition, due to the complicated nature of the manufacturing process, there are also problems in that the production rate is lowered and thus mass production is particularly complicated.  
     SUMMARY  
      Accordingly, the present invention is conceived to solve the aforementioned and other problems in the prior art. An independent object of the present invention is to provide an insulator for a PTC heater, which is simple to manufacture and assemble, allows an increase in workability and production rate, and makes mass production possible, by removably coupling a pair of pieces separately manufactured to an anode terminal.  
      One embodiment of the present invention provides an insulator for a PTC heater enclosing an anode terminal. The insulator comprises a first piece having an opening formed therein for exposing a portion of a surface of an anode terminal, and a second piece having an opening formed therein for exposing a portion of the other surface of the anode terminal. The second piece is removably coupled to the first piece.  
      In some embodiments, a plurality of first guide protrusions and first guide grooves corresponding to the first guide protrusions are formed on respective surfaces of the first and second pieces facing each other along a longitudinal direction of the respective pieces. Grooves through which the first guide protrusions pass are formed at positions of the anode terminal corresponding to the first guide protrusions and the first guide grooves. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects, features and advantages of the present invention will become apparent from the following description of a preferred embodiment given in conjunction with the accompanying drawings, in which:  
       FIG. 1   a  is a perspective view of a conventional PTC rod assembly;  
       FIG. 1   b  is an exploded perspective view of the PTC rod assembly shown in  FIG. 1   a;    
       FIG. 2   a  is a perspective view of an insulator for a PTC heater according to a first embodiment of the present invention;  
       FIG. 2   b  is an exploded perspective view of the insulator shown in  FIG. 2   a;    
       FIG. 3   a  is a perspective view of an insulator for a PTC heater according to showing a second embodiment of the present invention;  
       FIG. 3   b  is an exploded perspective view of the insulator shown in  FIG. 3   a;    
       FIG. 4   a  is a perspective view of an insulator for a PTC heater according to a third embodiment the present invention; and  
       FIG. 4   b  is an exploded perspective view of the insulator shown in  FIG. 4   a.   
    
    
     DETAILED DESCRIPTION  
      Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.  
       FIG. 2   a  is a perspective view showing a first embodiment of an insulator for a PTC heater according to the present invention, and  FIG. 2   b  is an exploded perspective view of the first embodiment shown in  FIG. 2   a.    
      As shown in  FIGS. 2   a  and  2   b , the first embodiment of the insulator  100  for a PTC heater according to the present invention comprises a pair of pieces  110  and  120 , which are formed to extend in the longitudinal direction of an anode terminal  200  and are coupled to the anode terminal  200  to enclose the anode terminal  200 . The pair of pieces comprises a first piece  110  coupled to a top surface of the anode terminal  200 , a second piece  120  coupled to a bottom surface of the anode terminal  200  and removably coupled to the first piece  110 .  
      The first and second pieces  110  and  120  are respectively formed with openings  112  and  122  so that the top and bottom surfaces of the anode terminal  200  are partially exposed. Enlarged portions  114  and  124  are provided at both ends of the first and second pieces  110  and  120  to have a cross section larger than the remainder of first and second pieces  110  and  120 , respectively. In more detail, the openings  112  and  122  are portions through which PTC elements and heat transfer blocks (not shown) are seated and coupled. In addition, the enlarged portions  114  and  124  are provided to seat a PTC rod (not shown) between the enlarged portions  114  and  124  and to guide their coupling position.  
      In the illustrated embodiment of  FIGS. 2   a  and  2   b , five openings  112  are formed in the first piece  110 , each of which is formed to have a predetermined length in the longitudinal direction of the first piece  110 . As shown in  FIGS. 2   a  and  2   b , the openings  112  can be apart from each other at regular intervals. That is, in the illustrated embodiment, because the five openings  112  are formed in the first piece  110 , the number of the PTC elements or heat transfer blocks is limited to five.  
      On the other hand, the opening  122  formed in the second piece  120  extends in the longitudinal direction of the second piece  120 , and four pairs of first guide protrusions  126   a  are formed in the opening  122  to be spaced apart from each other at regular intervals in the longitudinal direction of the second piece  120 . Each pair of the first guide protrusions  126   a  face each other on opposite inside ends of the second piece  120 . That is, in the illustrated embodiment of  FIGS. 2   a  and  2   b , the opening  122  formed in the second piece  120  is divided into five regions by the four pairs of the first guide protrusions  126   a , so that the five PTC elements or heat transfer blocks are coupled thereto.  
      The first guide protrusions  126   a  divide the opening  122  formed in the second piece  120  into a plurality of the regions and allow the PTC elements or heat transfer blocks to be coupled to the second piece  120 , and at the same time, the first guide protrusions  126   a  are used to couple the first piece  110  and the second piece  120 . In addition, because each pair of the first guide protrusions  126   a  is formed to be spaced apart from adjacent pairs of guide protrusions  126   b  by a distance shorter than the width of the opening  122 , it is possible to allow the PTC elements or heat transfer blocks to be seated in the opening  122  without an additional support dividing the opening.  
      In more detail, the first guide protrusions  126   a  are formed to protrude toward the inside of the opening  122  formed in the second piece  120  and at the same time to protrude toward the top surface of the second piece  120  by a predetermined height. In addition, first guide grooves  116   a  are formed at positions of the first piece  110  corresponding to the first guide protrusions  126   a  of the second piece  120  such that the first guide protrusions  126   a  can be respectively inserted into the first guide grooves  116   a . Therefore, when coupling the first and second pieces  110  and  120  to each other, upper ends of the first guide protrusions  126   a  are respectively inserted into and coupled to the first guide grooves  116   a . At this time, the first guide grooves  116   a  and the first guide protrusions  126   a  are positioned in both side ends of the first and second pieces  110  and  120 , and more particularly, between adjacent openings  112 .  
      The anode terminal  200  is positioned between the first piece  110  and the second piece  120 , extends in the same direction as the longitudinal direction of the pieces  110  and  120 , and has a terminal portion  202  formed at an end. As shown in  FIGS. 2   a  and  2   b , the terminal portion can be bent at a predetermined angle. Further, passing grooves  206   a  are formed along both sides of the anode terminal  200  at positions corresponding to the first guide grooves  116   a  and the first guide protrusions  126   a  so that the first guide protrusions  126   a  can pass through the passing grooves  206   a . In this manner, the passing grooves  206   a  prevent the anode terminal  200  from moving through an inner space defined by the pair of pieces  110  and  120  when coupled to the pieces  110  and  120 .  
      Although the illustrated embodiment of  FIGS. 1   a  and  1   b  includes five openings  112 ,  122  to which the PTC elements or heat transfer blocks are coupled, in other embodiments each of the first piece  110  and the  120  can have any other number of openings  112 . That is, more or less of the openings or the divided regions of the opening may be formed. Further, in the present embodiment, the first guide grooves  116   a  and the first guide protrusions  126   a  are respectively formed in the first piece  110  and the second piece  120 , but the present invention is not limited to such a construction. Furthermore, although in the present embodiment, the single opening  122  is formed in the second piece  120  and the first guide protrusions  126   a  are formed in the opening  122 , the opening  122  may be divided into a plurality of regions by forming supports between the pairs of the first guide protrusions  126   a.    
      A process of assembling the first embodiment of the insulator  100  according to the present invention so configured will be described below.  
      First, the anode terminal  200  having the terminal portion  202  formed at an end thereof is provided. After preparing the first and second pieces  110  and  120  respectively above and below the anode terminal  200 , the first and second pieces  110  and  120  are coupled such that the anode terminal  200  is positioned in an the inner space defined by the pair of pieces  110  and  120 . At this time, the first guide protrusions  126   a  of the second piece  120  pass through the passing grooves  206   a  of the anode terminal  200  and then are inserted into and coupled to the first guide grooves  116   a  of the first piece  110 .  
      The insulator  100  is assembled as described above such that the pair of pieces  110  and  120  are separately manufactured and are coupled to each other to enclose the anode terminal  200 . Thus, it is easy to manufacture the insulator  100  and simple to assemble it, thereby enhancing the workability and increasing the production rate.  
       FIG. 3   a  is a perspective view showing a second embodiment of the insulator for a PTC heater according to the present invention, and  FIG. 3   b  is an exploded perspective view of the second embodiment shown in  FIG. 3   a.    
      As shown in  FIGS. 3   a  and  3   b , the second embodiment of the insulator  100  for a PTC heater according to the present invention comprises a pair of pieces  110  and  120 , which are coupled to an anode terminal  200  to enclose it, as in the first embodiment. The pair of pieces comprises a first piece  110  coupled to a top surface of the anode terminal  200 , a second piece  120  coupled to a bottom surface of the anode terminal  200  and removably coupled to the first piece  110 .  
      Here, because the second embodiment is similar to the first embodiment except for the enlarged portions  114  and  124  formed at both the ends of the first and second pieces  110  and  120 , the detailed descriptions of the similar portions will be omitted.  
      The first and second pieces  110  and  120  are formed with openings  112  and  122  so that the top and bottom surfaces of the anode terminal  200  are partially exposed. Enlarged portions  114  and  124  are provided in both ends of the first and second pieces  110  and  120 . These enlarged portions  114  and  124  have a cross section larger than the remainder of the first and second pieces  110  and  120 , respectively.  100401  A plurality of first guide protrusions  126   a  are formed along the second piece  120  and extend into the opening  122  of the second piece  120 . These first guide protrusions  126   a  are spaced apart from each other at regular intervals in the longitudinal direction of the second piece  120 . In addition, first guide grooves  116   a  are formed at positions of both side ends of the first piece  110  corresponding to the first guide protrusions  126   a  so that upper ends of the first guide protrusions  126   a  can be respectively inserted into the first guide grooves  11   6   a . Also, passing grooves  206   a  through which the first guide protrusions  126   a  pass are formed at positions of the anode terminal  200  corresponding to the first guide grooves  116   a  and the first guide protrusions  126   a.    
      The enlarged portions  114  and  124  are provided at both the ends of the first and second pieces  110  and  120 , as described above, and second guide protrusions  126   b  and second guide grooves  116   b  corresponding to the second guide protrusions  126   b  are formed on both opposite surfaces of the enlarged portions  114  and  124 . That is, the second guide protrusions  126   b  having the same shape as the first guide protrusions  126   a  are formed in both side ends of a top surface of each enlarged portion  124  of the second piece  120 , and the second guide grooves  11   6   b  corresponding to the second guide protrusions  126   b  and having the same shape as the first guide protrusions  126   a  are formed in both side ends of a bottom surface of each enlarged portion  114  of the first piece  110 . Therefore, the second guide protrusions  126   b  are inserted into and coupled to the second guide grooves  116   b  when the first and second pieces  110  and  120  are coupled together.  
      The second guide grooves  116   b  and the second guide protrusions  126   b  are formed outside both side ends of the anode terminal  200 , so that no passing groove is formed in the side ends of the anode terminal  200 .  
      A guide protrusion  126   c  is formed to protrude upward on a central portion of the top surface of each enlarged portion  124  of the second piece  120 , and a third guide groove  116   c  corresponding to the third guide protrusion  126   c  is further formed on a central portion of the bottom surface of each enlarged portion  114  of the first piece  110 . In addition, through-holes  206   c  are formed at positions of the anode terminal  200  corresponding to the third guide grooves  116   c  and the third guide protrusions  126   c  so that the third guide protrusions  126   c  pass through the through-holes  206   c . Thus, when the first and second pieces  110  and  120  are coupled to each other, the third guide protrusions  126   c  pass through the through-holes  206   c  and are then inserted into and coupled to the third guide grooves  116   c.    
      In addition, the third guide grooves  116   c  are formed along the first piece  110 , and the third guide protrusions  126   c  pass through the third guide grooves  116   c  and are coupled thereto. Thus, it is possible to securely couple the first and second pieces  110  and  120 .  
      Further, although in the present embodiment, the single opening  122  is formed in the second piece  120  and the first guide protrusions  126   a  are formed in the opening  122 , the opening  122  may be divided into a plurality of regions by forming supports between the respective pairs of the first guide protrusions  126   a.    
      In the second embodiment of the insulator  100  for a PTC heater, the second and third guide grooves  116   b  and  116   c  and the second and third guide protrusions  126   b  and  126   c  are further formed in addition to the first guide grooves  116   a  and the first guide protrusions  126   a . Thus, there is an advantage in that it is possible to increase the adhesion of the insulator  100  to the anode terminal  200 .  
       FIG. 4   a  is a perspective view showing a third embodiment of the insulator for a PTC heater according to the present invention, and  FIG. 4   b  is an exploded perspective view of the third embodiment shown in  FIG. 4   a.    
      As shown in  FIGS. 4   a  and  4   b , the third embodiment of the insulator  100  for a PTC heater according to the present invention comprises a pair of pieces  110  and  120 , which are coupled to an anode terminal  200  to enclose it, as in the first embodiment. The pair of pieces comprises a first piece  110  coupled to a top surface of the anode terminal  200 , a second piece  120  coupled to a bottom surface of the anode terminal  200  and removably coupled to the first piece  110 .  
      The first and second pieces  110  and  120  are formed with openings  112  and  122  so that the top and bottom surfaces of the anode terminal  200  are partially exposed to the outside. Enlarged portions  114  and  124  are provided in both ends of the first and second pieces  110  and  120  to have a cross section larger than the first and second pieces  110  and  120 , respectively.  
      Hereinafter, because the third embodiment is similar to the second embodiment, the descriptions of the similar portions will be omitted.  
      Five openings  112  are formed in the first piece  110 , and each of the openings  112  is formed to have a predetermined length in the longitudinal direction of the first piece  110 . The openings  112  are arranged to be spaced apart from each other at regular intervals. In addition, the opening  122  formed in the second piece  120  extends in the longitudinal direction of the second piece  120 . Four pairs of first guide protrusions  126   a  are formed along the opening  122  and spaced apart from each other at regular intervals in the longitudinal direction of the second piece  120 .  
      Gas discharge ports  118  are formed in the first piece  110  between the openings  112  to discharge gas generated when the PTC elements coupled to openings  112  generate heat. In addition, gas discharge ports  118  are also formed in the enlarged portions  114  of the first piece  110  so that the gas can be discharged to the outside.  
      Here, because the second piece  120  is formed with a single opening  122 , an additional gas discharge port is not necessary. However, gas discharge ports  128  are formed in the enlarged portions  124  in order to discharge the remaining gas in the opening  122  to the outside.  
      When supports are formed between the respective pairs of the first guide protrusions  126   a , it is preferred that the gas discharge ports be formed in the supports.  
      In addition to the embodiments of the present invention, by separately manufacturing any one of the first and second pieces after injection molding the other of the first and second pieces on the anode terminal, it is possible to couple them.  
      The insulator for a PTC heater according to the present invention comprises a pair of pieces separately manufactured and the pair of pieces are removably coupled to the anode terminal, whereby the manufacture and assembly thereof is simplified.  
      Also, due to the simplified manufacture and assembly, there are advantages in that the workability and production rate can be improved and mass production is made possible.  
      Although the insulator for a PTC heater according to the preferred embodiments of the present invention is described based on the aforementioned descriptions and accompanying drawings, this is merely for illustrative purposes. It will be apparent that those skilled in the art can make various modifications and changes thereto without departing from the spirit of the present invention. Various features and advantages of the invention are set forth in the following claims.