Patent Publication Number: US-10309444-B2

Title: Parking cable for vehicle and method of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims under 35 U.S.C. § 119(a) the benefit of priority to Korean Patent Application No. 10-2016-0150119 filed on Nov. 11, 2016, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     (a) Technical Field 
     The present disclosure relates to a parking cable for a vehicle and a method of manufacturing same. 
     (b) Background Art 
     In general, a parking brake for a vehicle is a kind of a safety device which restricts and brakes a vehicle wheel when the vehicle is parked. Such a parking brake is useful particularly when the vehicle is parked or stopped on an inclined road surface, thereby preventing the vehicle from slipping or rolling unintentionally. 
     There is a manual parking brake, which is operated as a driver pulls or releases a parking lever or parking brake lever. There is also an electronic parking brake, which is operated as a driver manipulates a button. The manual parking brake and the electronic parking brake each include a parking brake cable, i.e., a parking cable in common. 
     As illustrated in  FIG. 1 , a parking cable  10  in the related art includes an inner cable  12 , which has a coating layer  11 , a conduit  14 , which is manufactured in a tube shape by winding a metallic wire, and a protective outer coating layer  16  coated on an outer diameter of the conduit  14 . The parking cable  10  has a structure in which the inner cable  12  is movably inserted and disposed in an inner diameter portion of the conduit  14 . 
     As illustrated in  FIG. 4 , the parking cable  10  is connected between an operating unit  20 , such as a parking lever, and a brake system  22  for restricting the vehicle wheel. 
     Therefore, a parking braking operation of the brake system  22  is carried out as follows. The inner cable  12  in the parking cable  10  is pulled by pulling the operating unit  20 . Because configurations and operations of the operating unit  20  and the brake system  22  are publicly known technologies, specific descriptions thereof will be omitted herein. 
     However, in the case of the parking cable  10  in the related art, both of the inner cable  12  and the conduit  14  are made of a metallic material. Thus, metal-to-metal friction occurs when the inner cable  12  is moved in the inner diameter portion of the conduit  14 . As a result, there is a problem in that operational efficiency and durability of the parking cable deteriorate due to high frictional resistance. 
     Therefore, more recently, a separate liner, which reduces frictional resistance and guides a smooth movement of the inner cable, is inserted between the inner cable and the conduit of the parking cable. 
     The above information disclosed in this Background section is only for enhancing the understanding of the background of the disclosure. Therefore, the Background section may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY OF THE DISCLOSURE 
     The presently disclosed parking cable embodiments have been made in an effort to solve the above-described problems associated with the prior art. A parking cable for a vehicle is provided and has a new structure. The structure includes a plurality of plastic split type liners, which reduces frictional resistance between an inner cable and a conduit. The plurality of plastic liners is press-fitted and disposed to a desired position in an inner diameter portion of the conduit. As a result, the plastic split type liners may serve as a guide that ensures force for smoothly moving the inner cable and improve in-line assembly properties. A method of manufacturing the parking cable. 
     In one aspect, the present disclosure provides a parking cable for a vehicle. The parking cable includes: a conduit, which has a tube shape; a protective outer coating layer coated on an outer diameter of the conduit; a plurality of split type liners, which is press-fitted into an inner diameter of the conduit; and an inner cable, which is movably inserted into the respective split type liners. The plurality of split type liners is press-fitted and disposed at positions that deviate from an in-line assembly section and a curved section in the entire length section of the conduit. The plurality of split type liners includes first split type liners, which are press-fitted into an inner diameter portion of the conduit, and second split type liners, which are press-fitted into both end portions of the conduit after the first split type liners are press-fitted into the inner diameter portion of the conduit. 
     In an embodiment, a fine protrusion may be integrally formed on an outer diameter portion of a first split type liner press-fitted into the conduit, and locked by coming into close contact with an inner diameter surface of the conduit. 
     In another embodiment, locking ends may be formed by expanding outer end portions of the second split type liners press-fitted into both end portions of the conduit, and locked by coming into close contact with an outer surface of the conduit. 
     In still another embodiment, cap casings for connecting the parking cable to an operating unit and a brake system may be assembled, by swaging, to outer diameter portions at both ends of the conduit coated with the protective outer coating layer. 
     In yet another embodiment, when the cap casing is swaged, a locking end formed at an outer end portion of the second split type liner may be fixed by receiving force for pressing the cap casing by swaging and compressing force of a seal present in the cap casing. 
     In another aspect, the present disclosure provides a method of manufacturing a parking cable for a vehicle. The method includes: i) manufacturing a conduit having a predetermined diameter by winding a metallic wire in a cylindrical shape; ii) coating an outer diameter of the conduit with a protective outer coating layer; iii) cutting the conduit coated with the protective outer coating layer to a desired predetermined length by using a cutting means; iv) press-fitting a plurality of split type liners into an inner diameter portion of the conduit at positions that deviate from an in-line assembly section and a curved section in the entire length section of the conduit; and v) assembling cap casings for connecting the parking cable to an operating unit and a brake system, by swaging, to outer diameter portions at both ends of the conduit coated with the protective outer coating layer. 
     In an embodiment, in step iv), the plurality of split type liners may include first split type liners and second split type liners. The plurality of split type liners may be press-fitted and disposed at positions that deviate from the in-line assembly section and the curved section in the entire length section of the conduit. The second split type liners may be press-fitted into both end portions of the conduit after the first split type liners of the plurality of split type liners are pressed into the inner diameter portion of the conduit first. 
     In another embodiment, when a first split type liner is press-fitted into the inner diameter portion of the conduit, a fine protrusion formed on an outer diameter portion of the first split type liner may be locked by coming into close contact with an inner diameter surface of the conduit. 
     In still another embodiment, when the second split type liners are press-fitted into both end portions of the conduit, a locking end formed on an outer end portion of the second split type liner may be locked by coming into close contact with an outer surface of the conduit. 
     In yet another embodiment, when the cap casing is swaged in step v), a locking end formed on an outer end portion of the second split type liner may be fixed by receiving force for pressing the cap casing by swaging and compressing force of a seal present in the cap casing. 
     Through the aforementioned technical solutions, the present disclosure provides the effects below. 
     First, since the plurality of split type liners including the first and second split type liners are press-fitted and disposed at the positions that deviate from the in-line assembly section and the curved section in the entire length section of the parking cable, no liner is embedded in assembly and curved sections of the parking cable. As a result, it is possible to eliminate force by which the parking cable returns back to the original position by elastic restoring force of the liner in the assembly and curved section of the parking cable. 
     Second, since the force by which the parking cable returns back to the original position by elastic restoring force of the liner in the assembly and curved sections of the parking cable is eliminated, the operator may handle the operation of assembling the parking cable to the vehicle body in a desired manner. As a result, the operator may perform the operation of assembling the assembly and curved portion of the parking cable to the vehicle body in a very comfortable position, thereby greatly improving assembly workability of the operator who assembles the parking cable to the vehicle body. 
     Third, even in a case in which the split type liners are embedded in the positions that deviate from the in-line assembly section and the curved section instead of the entire length section of the parking cable, the split type liners may easily serve as a guide, which provides force for smoothly moving the inner cable when a parking brake is operated. 
     Other aspects and embodiments of the disclosure are discussed infra. 
     It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuel derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
     The above and other features of the disclosure are discussed infra. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the present disclosure will now be described in detail with reference to certain embodiments thereof illustrated in the accompanying drawings, which are given hereinbelow by way of illustration only, and thus are not intended to limit the present disclosure, and wherein: 
         FIG. 1  is a cross-sectional view illustrating a parking cable in the related art; 
         FIG. 2  is a cross-sectional view illustrating a part of a parking cable with an embedded one-piece liner; 
         FIG. 3  is a partially enlarged cross-sectional view illustrating a method of manufacturing the parking cable with the embedded one-piece liner; 
         FIG. 4  is a view illustrating a state in which the parking cable of  FIGS. 2 and 3  with the embedded one-piece liner is installed and mounted in a vehicle body; 
         FIG. 5  is a partially enlarged cross-sectional view illustrating a parking cable and a method for manufacturing the same according to the present disclosure; and 
         FIG. 6  is a view illustrating a state in which the parking cable of  FIG. 5  according to the present disclosure is installed and mounted in the vehicle body. 
     
    
    
     It should be understood that the appended drawings are not necessarily to scale and thus may present a somewhat simplified representation of various preferred features illustrative of the basic principles of the disclosure. The specific design features of the present disclosure as described herein, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment. 
     In the figures, like reference numbers refer to the same or equivalent parts of the present disclosure throughout the several figures of the drawing. 
     DETAILED DESCRIPTION 
     Hereinafter, reference will now be made in detail to various embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings and described below. While the disclosure will be described in conjunction with various embodiments, it will be understood that the present description is not intended to limit the disclosure to those embodiments. On the contrary, the disclosure is intended to cover not only the disclosed embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the disclosure as defined by the appended claims. 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. 
     First, to help understand the present disclosure, the following description will be made with regard to a structure in which a liner is inserted over an entire length section of a parking cable. 
       FIG. 2  is a cross-sectional view illustrating a part of a parking cable in which a one-piece liner is embedded over an entire length section.  FIG. 3  is a partially enlarged view illustrating a method of manufacturing the parking cable in which the liner is embedded over the entire length section. 
     As illustrated in  FIG. 2 , a parking cable  10  has a liner. The parking cable  10  includes an inner cable  12 , which has a coating layer  11 , a one-piece liner  30 , which has a tubular structure into which the inner cable  12  is movably inserted, a conduit  14 , which is manufactured in a tube shape by winding a metallic wire, and a protective outer coating layer  16  with which an outer diameter of the conduit  14  is coated. 
     In this embodiment, the one-piece liner  30  is inserted between an outer diameter of the inner cable  12  and an inner diameter of the conduit  14  over an entire length section of the parking cable  10 . The entire length section includes a length connected between an operating unit and a brake system of a vehicle. 
     As illustrated in  FIG. 3 , a process of manufacturing the parking cable  10  having the one-piece liner  30  includes a step of inserting the inner cable  12  into the one-piece liner  30 . The process also includes a step of winding the conduit  14  around an outer diameter of the liner  30 . The process also includes a step of coating the outer diameter of the conduit  14  with the protective outer coating layer  16 . The parking cable  10  is cut to a predetermined length by using a cutting means. Finally, cap casings  24  are assembled, such as by swaging, to both end portions of the parking cable  10  and which are connected to the operating unit  20  and the brake system  22 , respectively. 
     Therefore, the process of assembling the parking cable  10  is completed by connecting the cap casing  24  with the operating unit  20  such as a parking lever and the brake system  22  for restricting a vehicle wheel, and by assembling several portions of the parking cable  10 , which are disposed between the cap casings  24 , to a vehicle body. 
     Therefore, the parking brake operation of the brake system  22  is carried out as the inner cable  12  in the parking cable  10  is pulled by pulling the operating unit  20 . In this embodiment, the inner cable  12  is moved in the inner diameter of the one-piece liner  30  made of a plastic material instead of being moved in the conduit  14 . 
     In this embodiment, frictional resistance between the metallic inner cable  12  and the plastic one-piece liner  30  is greatly reduced in comparison with the existing metal-to-metal frictional resistance between the metallic inner cable  12  and the metallic conduit  14 . The one-piece liner  30  serves as a guide for guiding a movement of the inner cable  12 . As a result, it is possible to ensure operating force for smoothly pulling the inner cable  12 , and thus to improve operational efficiency and durability of the parking cable. 
       FIG. 4  illustrates a state in which the parking cable  10 , in which the one-piece liner  30  is embedded over the entire length section, is installed between the operating unit  20  and the brake system  22 . The parking cable  10  is installed and mounted in a state in which several portions of the parking cable  10  are curved in accordance with a structure of the vehicle body. More particularly, several portions of the parking cable  10  are curved in an in-line assembling section in which several portions of the parking cable  10  are mounted to the vehicle body in the entire length section of the parking cable  10 , or the several portions of the parking cable  10  are curved to correspond to a complicated shape of the vehicle body. 
     In this embodiment, when an operator assembles the parking cable  10  to the vehicle body in a state in which the parking cable  10  is curved in the in-line section, the one-piece liner  13  is also curved in a curved portion of the parking cable  10  so as to have elastic restoring force. 
     In other words, since the one-piece liner  13  is made of a plastic material and has a tube shape, the one-piece liner  13  has its own elastic restoring force when the one-piece liner  13  is curved. 
     Therefore, the curved portion of the parking cable  10  returns back to the original position (a position before the parking cable  10  is curved) by the elastic restoring force of the one-piece liner  13 . As a result, there is a problem in that workability deteriorates when the operator assembles the parking cable to the vehicle body. 
     For example, the operator needs to assemble the parking cable  10  to the vehicle body in a state in which the operator holds a tool by using one hand and holds the curved portion of the parking cable  10  by using the other hand so as to prevent the parking cable  10  from returning back to the original position. As a result, there is a drawback in that assembly workability of the operator deteriorates. 
     Because the parking cable  10  returns back to the original position (the position before the parking cable  10  is curved) from the curved position by the elastic restoring force of the one-piece liner  30 , there is a drawback or resulting disadvantage. Assembly workability of the operator deteriorates because it is very difficult for the operator to insert the curved parking cable into a mounting hole of a bracket  26  formed on the vehicle body. 
     To solve the aforementioned drawbacks, according to the present disclosure, a plurality of split type liners for reducing frictional resistance is press-fitted and disposed between the outer diameter of the inner cable and the inner diameter of the conduit. The plurality of split type liners is press-fitted and disposed at positions that deviate from the in-line assembly section and the curved section of the entire length section of the parking cable (i.e., an entire length section of the conduit), thereby providing a force for smoothly moving the inner cable and improving in-line assembly workability. 
       FIG. 5  is a cross-sectional view illustrating a parking cable for a vehicle and a method of manufacturing the same according to the present disclosure.  FIG. 6  is a view illustrating a state in which the parking cable of  FIG. 5  according to the present disclosure is installed between the operating unit and the brake system, and illustrating a section in which liners are partially inserted in the entire length section of the parking cable. 
     The parking cable  10  according to the present disclosure includes an inner cable  12 , which has a coating layer  11 , a plurality of split type liners  13  into which the inner cable  12  is movably inserted, a conduit  14 , which is manufactured in a tube shape by winding a metallic wire, and a protective outer coating layer  16  with which an outer diameter of the conduit  14  is coated. In this embodiment, the parking cable is given the same reference number  10  as in the earlier discussion of the existing parking cable because each is a parking cable. The differences lie in the inner structures of the parking cables. Further, the term split type liner means a liner segment of a length less than an entire length of the parking cable or conduit. 
     In this case, the split type liners  13  are press-fitted and fixed in an inner diameter of the conduit  14  only at desired positions over an entire length section of the parking cable  10 . The entire length section is a length connected between the operating unit and the brake system of the vehicle. 
     To this end, first, the hollow conduit  14  having a predetermined diameter is manufactured by winding a flat metallic wire to form a cylindrical structure. 
     Next, the outer diameter of the conduit  14  is coated with the protective outer coating layer  16 . 
     Next, a cutting step of cutting the conduit  14 , which has been coated with the protective outer coating layer  16 , to a desired predetermined length. The desired length is a length that connects the operating unit and the brake system. The conduit  14  is cut to the desired length by using a cutting means. 
     Next, the plurality of split type liners  13  is press-fitted into the inner diameter portion of the conduit  14 . The plurality of split type liners  13  is press-fitted at the desired positions in the entire length section of the conduit  14 . As a result, the split type liners  13  are disposed at the desired positions so as to be spaced apart from each other. 
     The plurality of split type liners  13  includes first split type liners  13 - 1 , which are completely press-fitted into the inner diameter portion of the conduit, and the plurality of split type liners  13  also includes second split type liners  13 - 2 , which are press-fitted into both end portions of the conduit  14  after the first split type liners  13 - 1  are press-fitted into the inner diameter portion of the conduit  14 . 
     Therefore, unlike the existing parking cable  10  having a structure in which the one-piece liner  13  is inserted and disposed over the entire length section, in the present disclosure, the plurality of split type liners  13  is press-fitted into the inner diameter portion of the conduit  14 , such that the split type liners  13  are press-fitted and disposed only at the desired positions in the entire length section of the parking cable  10  (i.e., the entire length section of the conduit  14 ). 
     In other words, when the plurality of split type liners  13  is press-fitted into the inner diameter portion of the conduit  14 , the split type liners  13  are press-fitted and disposed at the positions that deviate from the in-line assembly section and the curved section in the entire length section of the parking cable. Again, the entire length section of the parking cable  10  is a length connected between the operating unit and the brake system of the vehicle, as illustrated in  FIG. 6 . 
     In this embodiment, as illustrated in  FIG. 6 , fine protrusions  17  are integrally formed on an outer diameter portion of the first split type liner  13 - 1  press-fitted into the conduit  14 . The fine protrusion  17  serves as a locking structure, which is locked by coming into close contact with an inner diameter surface of the conduit  14 . As a result, the first split type liner  13 - 1  may remain securely fixed at the desired position, which is a position that deviates from the in-line assembly section and the curved section. 
     Referring to  FIG. 5 , cap casings  24  are assembled, such as by swaging, to both end portions of the parking cable  10 . Both end portions of the parking cable  10  are connected with the operating unit  20  and the brake system  22 , respectively. 
     Because inner sections adjacent to both end portions of the parking cable  10  are also curved to connect to the operating unit  20  and the brake system  22 , no separate liner is embedded in the inner sections adjacent to both end portions of the parking cable  10 . The second split type liners  13 - 2  are press-fitted into both end portions of the parking cable  10  so as to straightly guide the inner cable. 
     In this embodiment, in a state in which several first split type liners  13 - 1  are already press-fitted in the in-line assembly section and the curved section in the entire section of the parking cable  10 , the second split type liners  13 - 2  are subsequently press-fitted into both end portions of the parking cable  10 . 
     The second split type liners  13 - 2 , which are press-fitted into both end portions of the parking cable  10 , that is, both end portions of the conduit  14 , may be withdrawn out of place while moving in a longitudinal direction of the parking cable  10 . Therefore, locking ends  18 , which are locked by coming into close contact with an outer surface of the conduit  14 , are formed on an outer portion of the second split type liner  13 - 2 . The locking ends  18  are formed by expanding the outer portion of the second split type liner  13 - 2  before the cap casings  24  are swaged, as illustrated in  FIG. 5 . 
     Therefore, the second split type liners  13 - 2  are press-fitted into the inner diameter portions at both ends of the conduit  14 . At the same time, the locking ends  18  of the second split type liners  13 - 2  are caught by the outer surfaces of the conduit  14 . The cap casings  24  for connecting the parking cable to the operating unit  20  and the brake system  22  are then assembled, such as by swaging, to the outer diameter portions at both ends of the conduit  14 , which has been coated with the protective outer coating layer  16 , as illustrated in  FIG. 5 . 
     In this embodiment, the locking end  18  of the second split type liner  13 - 2  simultaneously receives both a force for pressing the cap casing  24  by swaging and a compressing force of a seal  28  present in the cap casing  24 . As a result, it is possible to securely maintain the state in which the locking end  18  is locked and in close contact with the outer surface of the conduit  14 , which prevents the withdrawal of the second, split type liner  13 - 2 . 
     Therefore, since the split type liners  13 , including the first and second split type liners  13 - 1  and  13 - 2 , are press-fitted, disposed, and securely fixed at the positions that deviate from the in-line assembly section and the curved section in the entire length section of the parking cable  10 , no liner is disposed in the assembly at curved sections of the parking cable  10  when the operator assembles the parking cable  10  to the vehicle body in the in-line section. As a result, it is possible to eliminate force by which the parking cable  10  returns back to the original position by elastic restoring force of the liner. 
     Therefore, in a state in which the force by which the parking cable  10  returns back to the original position by elastic restoring force of the liner is eliminated, the operator may handle the operation of assembling the parking cable to the vehicle body in a desired manner. As a result, the operator may perform the operation of assembling the assembly and curved portions of the parking cable  10  to the vehicle body (e.g., an operation of inserting the parking cable into the mounting hole of the bracket  26  formed on the vehicle body) in a very comfortable position, thereby greatly improving assembly workability of the operator who assembles the parking cable to the vehicle body. 
     Of course, even in a case in which the split type liners  13  are embedded only in the positions that deviate from the in-line assembly section and the curved section instead of the entire length section of the parking cable  10 , the split type liners  13  may easily serve as a guide, which provides force for smoothly moving the inner cable  12  when a parking brake is operated. As a result, it is possible to ensure operational efficiency and durability of the parking cable. 
     The disclosure has been described in detail with reference to various embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the appended claims and their equivalents.