Abstract:
A method of mounting a terminal connector to a transmission case, the transmission case including a mount portion with a mount hole, the transmission case enclosing a control valve unit, the terminal connector gathering wirings extending from the control valve unit. The method includes inserting the terminal connector into the mount hole until a portion of the terminal connector projects outward from the mount hole, and pulling the inserted terminal connector from an outside of the transmission case outward to thereby mount the terminal connector to the mount portion. A structure including a connector mounting arm of the control valve unit, and the terminal connector mounted into the mount hole of the mount portion. The terminal connector includes a holder portion engaged with the connector mounting arm and slidable relative to the connector mounting arm upon mounting the terminal connector to the mount portion.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a method and structure for mounting a terminal connector to a transmission case of an automatic transmission (AT), and more specifically to the method and structure for mounting a terminal connector which is adapted for collecting wirings extending between a control valve unit and various sensors which are used in the AT.  
           [0002]    Generally, the AT includes a transmission section for changing rotation input transmitted from an input shaft and a control valve unit for developing and transmitting a hydraulic pressure control signal to the transmission section on the basis of a speed change control command. Recent control valve units include a plurality of electromagnetic control valves and sensors and a terminal connector for wirings which connect the electromagnetic control valves and the sensors and transmit drive currents and current signals therebetween. The terminal connector is fixed to a transmission case.  
           [0003]    [0003]FIG. 7 is a schematic diagram showing a terminal connector mounting structure of a related art when viewed from an underside thereof after removing an oil pan. In the structure shown in FIG. 7, reference numerals  100 ,  101  and  102  denote transmission case, control valve unit and terminal connector, respectively. Upon assembling control valve unit  101  to transmission case  100 , wirings extending from control valve unit  101  are gathered by terminal connector  102 . Then, terminal connector  102  is pushed from an inner position in transmission case  100  to an outer mount position, shown in FIG. 7, therein and secured thereto.  
         SUMMARY OF THE INVENTION  
         [0004]    In the structure shown in FIG. 7, handling space S indicated by broken line of FIG. 7, must be formed for allowing the operation of outwardly pushing terminal connector  102  and mounting terminal connector  102  to transmission case  100  upon assembling control valve unit  101  to transmission case  100 . Therefore, it is required to increase a size of transmission case  100  by handling space S. This will cause increase in weight and dimension of transmission case  100 .  
           [0005]    [0005]FIG. 8 is a schematic diagram similar to FIG. 7, but showing a modification of the structure of FIG. 7. In FIG. 8, terminal connector  102  is mounted to transmission case  100  by inserting terminal connector  102  from the outside of transmission case  100  thereinto. In the structure shown in FIG. 8, control valve unit  101  and terminal connector  102  are arranged offset from each other in a direction perpendicular to a sheet surface of FIG. 8. This is because, if control valve unit  101  and terminal connector  102  are arranged such that lower side portions thereof are substantially flush with each other, wirings between control valve unit  101  and terminal connector  102  will be brought into contact with control valve unit  101  upon inserting terminal connector  102  into transmission case  100 . In such an offset arrangement, there will occur increase in size of transmission case  100 .  
           [0006]    Further, in an offset arrangement where terminal connector  102  is disposed between control valve unit  101  and the transmission section, an operation of coupling connector  101 A of control valve unit  101  and connector  102 A of terminal connector  102  as shown in FIG. 8, cannot be performed after assembling control valve unit  101  to transmission case  100 . Therefore, the coupling operation must be performed before assembling control valve unit  101  to transmission case  100 . This will cause excessive increase in length of the wiring connecting connectors  101 A and  102 A, so that there will occur various inconveniences due to the excessively increased length of the wiring.  
           [0007]    Furthermore, electromagnetic control valves of control valve unit  101  are adapted to apply control fluid pressure to the transmission section via fluid passages. For the purpose of reducing the number of the fluid passages, it is required to arrange the electromagnetic control valves within control valve unit  101  at a position closer to the corresponding fluid passages of the transmission section. However, in a case where terminal connector  102  is arranged on the side of an oil pan in offset relation to control valve unit  101 , the electromagnetic control valves and sensors of control valve unit  101  must be disposed on the side of the oil pan in order to reduce a length of the wiring connecting the respective connectors of control valve unit  101  and terminal connector  102 . This will cause increase in number of the fluid passages connecting the electromagnetic control valves with the transmission section, resulting in lowering freedom of layout of the fluid passages.  
           [0008]    It would threrefore be desirable to provide a method and structure for mounting a terminal connector to a transmission case of an automatic transmission (AT), which is capable of providing efficient wiring and serves for reducing size and weight of the AT.  
           [0009]    In one aspect of the present invention, there is provided a method of mounting a terminal connector to a transmission case, the transmission case including a mount portion with a mount hole, the transmission case enclosing a control valve unit, the terminal connector gathering a plurality of wirings extending from the control valve unit, the method comprising:  
           [0010]    inserting the terminal connector into the mount hole of the mount portion until a portion of the terminal connector projects outward from the mount hole; and  
           [0011]    pulling the inserted terminal connector from an outside of the transmission case outward to thereby mount the terminal connector to the mount portion of the transmission case.  
           [0012]    In a further aspect of the present invention, there is provided a structure comprising:  
           [0013]    a transmission case including a mount portion defining a mount hole;  
           [0014]    a control valve unit within the transmission case, the control valve unit including a connector mounting arm; and  
           [0015]    a terminal connector mounted into the mount hole of the mount portion, the terminal connector including a holder portion engaged with the connector mounting arm, the holder portion being slidable relative to the connector mounting arm upon mounting the terminal connector to the mount portion of the transmission case. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a side view of a transmission case of an automatic transmission, according to an embodiment of the present invention, showing a terminal connector mounting structure in which a terminal connector is mounted to the transmission case;  
         [0017]    [0017]FIG. 2 is a schematic diagram showing an arrangement of the terminal connector and a control valve unit relative to the transmission case;  
         [0018]    [0018]FIG. 3A is a top plan view of the terminal connector;  
         [0019]    [0019]FIG. 3B is an enlarged front view of the terminal connector shown in FIG. 3A;  
         [0020]    [0020]FIG. 3C is a view similar to FIG. 3A, but showing the terminal connector when the terminal connector is turned about the center axis at substantially a right angle;  
         [0021]    [0021]FIG. 3D is an enlarged side view of the terminal connector shown in FIG. 3C;  
         [0022]    [0022]FIGS. 4A and 4B are schematic diagrams illustrating an operation of mounting the control valve unit to the transmission case;  
         [0023]    [0023]FIGS. 5A and 5B are a side view of a jig or tool used in the embodiment shown in FIGS.  1 - 4 B, and a top plan view the tool, respectively;  
         [0024]    [0024]FIG. 6 is a schematic diagram of the mounting structure as viewed from a lower side of the transmission case;  
         [0025]    [0025]FIG. 7 is a schematic diagram showing a mounting structure of a related art as viewed from a lower side of a transmission case; and  
         [0026]    [0026]FIG. 8 is a schematic diagram similar to FIG. 7, but showing a modification of the mounting structure of FIG. 7.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]    Referring now to FIGS. 1 and 2, there is shown a structure for mounting a terminal connector to a transmission case of an automatic transmission (AT), according to an embodiment of the present invention. As illustrated in FIGS. 1 and 2, transmission case  1  includes mount portion  11  for terminal connector  2 . Mount portion  11  is disposed on a side wall of transmission case  1  and extends in vertical direction D 1  of transmission case  1 , namely, in a direction substantially perpendicular to an imaginary bottom face of transmission case  1 . Mount portion  11  has mount hole  11 A shown in FIGS. 4A and 4B into which terminal connector  2  is mounted. Mount hole  11 A has a generally cylindrical shape. An outer periphery of mount portion  11  defines an outlet of mount hole  11 A from which connector portion  21  of terminal connector  2  outward projects. The outer periphery of mount portion  11  is disposed substantially perpendicular to a center axis of mount hole  11 A. As illustrated in FIG. 2, control valve unit  4  is disposed within a lower end portion of transmission case  1 . Control valve unit  4  and terminal connector  2  are designed in module.  
         [0028]    Referring to FIGS.  3 A- 3 D, terminal connector  2  is explained. Terminal connector  2  includes generally cylindrical body portion  29  and connector portion  21  connected with body portion  29 . Body portion  29  is adapted to be disposed within mount hole  11 A of mount portion  11 . Connector portion  21  is disposed at an axial end, namely, an upper end as shown in FIGS. 3B and 3D, of body portion  29 . Connector portion  21  is adapted to project from mount hole  11 A and connectable with an external connection terminal. Body portion  29  has engaging grooves  22 , check groove  23  and seal groove  24  on an outer circumferential surface thereof. These grooves  22 ,  23  and  24  are spaced from each other in an axial direction of body portion  29 . Engaging grooves  22  are engageable with tool  7  as explained later and formed parallel to each other on the outer circumferential surface of body portion  29 . Engaging grooves  22  extend parallel to an imaginary plane substantially perpendicular to the axial direction of body portion  29 . The axial direction of body portion  29  is hereinafter referred to as an axial direction of terminal connector  2 . Check groove  23  extends in the circumferential direction of body portion  29 . Check groove  23  is formed to determine a sealing position where mount portion  11  is sealed by O-ring seal  25  which is press-fitted to mount hole  11 A upon mounting terminal connector  2  to mount portion  11  as explained later. O-ring seal  25  is fitted into seal groove  24  formed along the entire outer circumferential surface of body portion  29 . Stop  28  is disposed at an opposite axial end, namely, a lower end as shown in FIGS. 3B and 3D, of body portion  29 . Connection terminal  26  and holder portion  27  are disposed on a lower side of stop  28 . Connection terminal  26  is connected with an actuator disposed on the side of control valve unit  4 . Holder portion  27  is formed into a generally rectangular hollow box shape having an open end, and extends along the axial direction of terminal connector  2 . Holder portion  27  has slit  27   a  in a front wall thereof and engaging opening  27   b  in one side wall thereof as shown in FIGS. 3B and 3D, respectively. Slit  27   a  extends along the axial direction of terminal connector  2  and allows connector mounting arm  41  to be inserted into holder portion  27  upon coupling holder portion  27  with connector mounting arm  41 . Engaging opening  27   b  extends along the axial direction of terminal connector  2  and is engaged with engaging projection  41   d  of connector mounting arm  41  as shown in FIGS. 3B and 3D. Engaging opening  27   b  allows holder portion  27  to slide relative to connector mounting arm  41  with engaging projection  41   d  in the axial direction. Terminal connector  2  includes first region R 1  for an inserting operation of terminal connector  2  into mount hole  11 A upon mounting terminal connector  2  to transmission case  1 , and second region R 2  for pulling terminal connector  2  subsequent to the inserting operation. First region R 1  axially extends from a distal end of connector portion  21  to a portion of O-ring seal  25  which comes into contact with a periphery of an inlet of mount hole  11 A upon inserting terminal connector  2 . Second region R 2  axially extends from the portion of O-ring seal  25  to an upper end of stop  28 , namely, to the lower end of body portion  29 . Second region R 2  is designed to extend at an axial distance smaller than engaging opening  27   b.    
         [0029]    Connector mounting arm  41  is fixedly supported on control valve unit  4 . Connector mounting arm  41  is engaged with holder portion  27  of terminal connector  2 . Connector mounting arm  41  includes support portion  41   a  secured to control valve unit  4 , fall-down preventing portion  41   c  received in holder portion  27 , and slide portion  41   b  disposed between support portion  41   a  and fall-down preventing portion  41   c . As illustrated in FIG. 3D, slide portion  41   b  has a width smaller than that of support portion  41   a  and is slidably moved into holder portion  27 . Fall-down preventing portion  41   c  has a width larger than that of engaging opening  27   b  of holder portion  27  as shown in FIG. 3D. Fall-down preventing portion  41   c  abuts on a peripheral portion surrounding engaging opening  27   b  of holder portion  27  to thereby be prevented from projecting from engaging opening  27   b  and falling down rightward in FIG. 3B. Engaging projection  41   d  is formed on fall-down preventing portion  41   c  and outwardly extends through engaging opening  27   b . Holder portion  27  can be prevented from being disengaged from connector mounting arm  41  by abutment of engaging projection  41   d  on a lower end periphery of engaging opening  27   b.    
         [0030]    Upon coupling terminal connector  2  to connector mounting arm  41  of control valve unit  4 , engaging projection  41   d  is inserted from the open end of holder portion  27  into the inside space by expanding slit  27   a  of holder portion  27  wide open. Fall-down preventing portion  41   c  with engaging projection  41   d  is further moved inside until engaging projection  41   d  is engaged in engaging opening  27   b . Connector mounting arm  41  and terminal connector  2  are thus coupled with each other and form a unitary module. Owing to the coupling of connector mounting arm  41  and terminal connector  2 , terminal connector  2  can slidably move relative to connector mounting arm  41  in the axial direction and can pivot about engaging projection  41   d  until the open end of holder portion  27  is contacted with a front surface of slide portion  41   b . The axially sliding movement of terminal connector  2  is limited within a range equivalent to a length of engaging opening  27   b  of holder portion  27 .  
         [0031]    Referring to FIGS.  4 A- 4 B, a method of mounting the unitary module of control valve unit  4  and terminal connector  2  to transmission case  1  will be explained hereinafter. FIGS. 4A and 4B illustrate a section of mount portion  11  of transmission case  1 , taken along line T-T of FIG. 1. First, the unitary module of control valve unit  4  and terminal connector  2  is moved into a lower portion of transmission case  1  through a bottom opening of transmission case  1 . As illustrated in FIG. 4A, connector portion  21  of terminal connector  2  is inserted into mount hole  11 A of mount portion  11  until connector portion  21  outward projects from mount hole  11 A and an outer periphery of O-ring seal  25  is contacted with an inner periphery of mount portion  11 . The inner periphery of mount portion  11  defines the inlet of mount hole  11 A from which terminal connector  2  is inserted into mount hole  11 A. First region R 1  of terminal connector  2  is inserted into mount hole  11 A during the inserting operation. At this state, control valve unit  4  is secured to transmission case  1  by means of bolts. Next, lift portion  7   c  of tool  7  is placed into engaging grooves  22  of body portion  29  of terminal connector  2 . Here, tool  7  is explained.  
         [0032]    [0032]FIGS. 5A and 5B illustrate tool  7  used in the mounting operation of terminal connector  2 . Tool  7  includes two grip portions  7   a  to be held by an operator, bearing portion  7   b  to be urged against the outer periphery of mount portion  11 , and lift portion  7   c  for lifting body portion  29  of terminal connector  2 . One of grip portions  7   a  is connected with bearing portion  7   b , and the other thereof is connected with lift portion  7   c . Grip portions  7   a  are joined together by pivot  7   d  so as to be rotatively moveable about pivot  7   d . Bearing portion  7   b  has a generally U-shape as shown in FIG. 5B. Lift portion  7   c  has a generally U-shape smaller in size than bearing portion  7   b  and is disposed inside bearing portion  7   b  as shown in FIG. 5B. Lift portion  7   c  is formed to be engageable in engaging grooves  22  of body portion  29  of terminal connector  2 . Bearing portion  7   b  and lift portion  7   c  are moveable to separate from each other by actuating grip portions  7   a.    
         [0033]    Referring back to FIG. 4B, there is shown an operation subsequent to insertion of first region R 1  of terminal connector  2  into mount hole  11 A and fitting lift portion  7   c  of tool  7  into engaging grooves  22 . When the operator actuates grip portions  7   a  as indicated by arrow F in FIG. 4B, bearing portion  7   b  is urged against the outer periphery of mount portion  11  of transmission case  1  to thereby cause a reaction force which is applied to lift portion  7   c . Lift portion  7   c  engaged in grooves  22  is forced to upward move and lift terminal connector  2 . O-ring seal  25  mounted on body portion  29  of terminal connector  2  is press-fitted into mount hole  11 A and moved to the sealing position where the sealing of mount portion  11  is ensured. Upon lifting terminal connector  2 , stop  28  comes into engagement with the inner periphery of mount portion  11  and prevents excessive upward lifting of terminal connector  2 . At this state, the operator can visually check whether or not check groove  23  of body portion  29  is seen. If check groove  23  is seen, it can be recognized that O-ring seal  25  is placed in the sealing position in mount hole  11 A and that the press-fitting operation of O-ring seal  25  can be completed. Tool  7  then is taken off terminal connector  2 .  
         [0034]    [0034]FIG. 6 shows the mounting state in which the unitary module of terminal connector  2  and control valve unit  4  is mounted to transmission case  1 , as viewed from the underside of transmission case  1 . As illustrated in FIG. 6, terminal connector  2  is disposed over control valve unit  4  in the direction perpendicular to the sheet surface of FIG. 6, namely, in vertical direction D 1  of transmission case  1  as shown in FIGS. 1 and 2. With the terminal connector mounting structure, handling space S, shown in FIG. 7, as required in the terminal connector mounting structure of the related art can be omitted. This serves for reducing size and weight of the A/T.  
         [0035]    As explained above, the terminal connector mounting method and structure of the present invention can omit the handling space for outward pushing a terminal connector to the mount position in a transmission case. Further, in the terminal connector mounting method and structure of the present invention, it is not required to connect the actuators of control valve unit  4  with terminal connector  2  after assembling control valve unit  4  to transmission case  1  as explained in the case shown in FIG. 8. Further, terminal connector  2  and control valve unit  4  do not require the corresponding connectors for coupling therebetween which are indicated at  101 A and  102 A in FIG. 8. Furthermore, in the terminal connector mounting method and structure of the present invention, a length of the wiring between terminal connector  2  and control valve unit  4  can be remarkably reduced, serving for preventing the wiring from being urged onto the transmission section and for saving the production cost.  
         [0036]    Further, upon mounting terminal connector  2  to transmission case  1 , positioning of terminal connector  2  relative to transmission case  1  can be readily performed merely inserting connector portion  21  of terminal connector  2  into mount hole  11 A of mount portion  11  of transmission case  1  over first region R 1 . In the subsequent operation of upward pulling terminal connector  2  with tool  7  over second region R 2 , stress applied to O-ring seal  25  can be balanced as compared with a pulling operation by hand. This can prevent O-ring seal  25  from being damaged due to unbalanced stress which will be applied to O-ring seal  25  if terminal connector  2  is upward pulled after inserting connector portion  21  in a tilting state into mount hole  11 A. O-ring seal  25 , therefore, can be moved to the sealing position in mount hole  11 A in which O-ring seal  25  can prevent leakage of an oil from mount portion  11 . Further, a stable insertion angle of terminal connector  2  can be obtained, whereby it is not necessary to ensure a length of mount hole  11 A which is required for limiting the insertion angle. As a result, material of transmission case  1  can be reduced in amount, and therefore, the weight of transmission case  1  can be decreased.  
         [0037]    Further, with the provision of holder portion  27  on terminal connector  2  and connector mounting arm  41  on control valve unit  4 , terminal connector  2  and control valve unit  4  can be formed as a unitary module. This serves for simultaneously performing the mounting operation of terminal connector  2  to mount portion  11  of transmission case  1  and the assembling operation of control valve unit  4  to transmission case  1 . Further, since holder portion  27  can slide on connector mounting arm  41 , the mounting operation of terminal connector  2  to mount portion  11  can be completed by upward pulling terminal connector  2  with tool  7  after assembling control valve unit  4  to transmission case  1 . This serves for improving the mountability of the terminal connector mounting structure.  
         [0038]    Furthermore, engaging projection  41   d  of connector mounting arm  41  can be kept in engagement with engaging opening  27   b  of holder portion  27  to thereby maintain the coupling of connector mounting arm  41  and holder portion  27  even after terminal connector  2  is mounted to mount portion  11 . Therefore, even when the AT is disassembled, for instance, for the purpose of the operational maintenance, the unitary module of terminal connector  2  and control valve unit  4  may not be disassembled. This serves for enhancing efficiency of the disassembling work.  
         [0039]    Further, since slide portion  41   b  of connector mounting arm  41  is formed into the small width as shown in FIG. 3D, holder portion  27  can slide relative to connector mounting arm  41  in not only the direction of the terminal connector pulling operation but a direction other than the direction of the terminal connector pulling operation. Namely, holder portion  27  can pivotally move about engaging projection  41   d  while keeping the sliding engagement with connector mounting arm  41 . This allows appropriate positioning of terminal connector  2  relative to mount portion  11  of transmission case  1  even if there is production error of transmission case  1  and control valve unit  4  or there occurs error in assembling control valve unit  4  to transmission case  1 . This enhances the mountability of the terminal connector mounting structure.  
         [0040]    Further, engaging grooves  22  are formed parallel to the imaginary plane substantially perpendicular to the axial direction of body portion  29  of terminal connector  2 . Namely, engaging grooves  22  are substantially perpendicular to the direction of the terminal connector pulling operation in which terminal connector  2  is upward pulled upon being mounted to mount portion  11 . Upon applying a force to the outer periphery of mount portion  11  of transmission case  1  via grip portion  7   a  of tool  7 , a reaction force is applied to lift portion  7   c  engaged with engaging grooves  22  to thereby upward pull terminal connector  2 . Thus, the positioning of tool  7  can be readily accomplished by the provision of engaging grooves  22 . This serves for lightening an operator&#39;s labor required for upward pulling terminal connector  2 . Furthermore, since the balanced pulling force can be applied to terminal connector  2  through the engagement of lift portion  7   c  of tool  7  with engaging grooves  22 , the stress exerted on O-ring seal  25  can be also balanced.  
         [0041]    Further, with the provision of check groove  23  on terminal connector  2 , the operator can visually check completion of the operation of mounting terminal connector  2  to mount portion  11 . The operator&#39;s labor, therefore, can be made less.  
         [0042]    Further, with the provision of stop  28  on terminal connector  2 , terminal connector  2  can be prevented from being excessively pulled upward. This serves for lessening the operator&#39;s labor.  
         [0043]    This application is based on prior Japanese Patent Application No. 2002-064238 filed on Mar. 8, 2002, the entire content of which is hereby incorporated by reference.  
         [0044]    Although the invention has been described above by reference to a certain embodiment of the invention, the invention is not limited to the embodiment described above. Modifications and variations of the embodiment described above will occur to those skilled in the art in light of the above teachings. The scope of the invention is defined with reference to the following claims.