Patent Publication Number: US-11031732-B2

Title: Lever-type connector

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based on Japanese Patent Application (No. 2016-174968) filed on Sep. 7, 2016, the contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a lever-type connector. 
     2. Description of the Related Art 
     Conventionally, a lever-type connector is known that can perform a connector fitting with a low insertion force due to a rotational force by rotating a lever pivotally mounted on a housing so that the connector is fitted into a mating housing of a mating connector (see, for example, JP-A-2012-69415). 
     In this lever-type connector, the housing is fitted into the mating housing, and thereafter the lever is pivoted from a fitting start position to a fitting completion position, and by engaging and locking to a flexible arm portion of a lock portion of the housing, thereby the housing maintains a state that the connector is fitted to the mating housing. 
     Before fitting to a mating connector, for example, at the time of packing or transporting, electrical wires can get caught on the lock portion of a housing undesirably so that a flexible arm portion can get lifted up, or the flexible arm portion can be pushed strongly by an operator&#39;s fingers causing damage. Even after fitting the connector, and when a load is further applied after an attempt to excessively rotate the lever, a load is applied to the flexible arm portion and deformation of the flexible arm portion may occur. In this way, when the flexible arm of the lock portion is deformed or damaged and the lever cannot be reliably locked into the fitting completion position, the locking of the lever by the lock portion of the housing is off, and the reliability of fitting with the mating connector may be reduced. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the above circumstances, and its objective is to provide a lever-type connector capable of protecting the lock portion of a housing and achieving high reliability in fitting with a mating connector. 
     In order to achieve the above objective, the lever-type connector according to the present invention is characterized by (1) to (5) as follows: 
     (1) a lever-type connector, including:
         a housing configured to be inserted and removed from a mating housing of a mating connector;   a lever, pivotally mounted on the housing, and that is pivotally operable between a temporary locking position and a fitting completion position of the lever, the lever including:
           a pair of side plates arranged along surfaces on both sides of the housing; and   an operating portion that connect ends of the side plates; and   
           a lock portion, provided on the housing, and that locks the lever positioned at the fitting completion position,   wherein the housing is configured to be fitted to the mating housing by rotating the lever from a fitting start position to the fitting completion position;   wherein the housing has a pair of walls, that are provided at both sides of the lock portion for locking the operating portion of the lever; and   wherein arm protection walls are provided on upper edges of the pair of walls respectively with extending inward so as to cover both sides of the flexible arm portion of the lock portion.       

     (2) The lever-type connector according to (1), wherein the operating portion is disposed above the arm protection wall when the lever is positioned at the fitting completion position. 
     (3) The lever-type connector according to (1) or (2), wherein the arm protection walls extend in parallel with an upper surface of the housing so as to close to each other. 
     (4) The lever-type connector according to any one of (1) to (3), wherein recess portions that externally fit the pair of walls are formed on the operating portion;
         wherein inner surfaces of the recessed portions contact outer surfaces of the pair of walls facing the inner surfaces respectively when the lever is positioned at the fitting completion position.       

     (5) The lever-type connector according to (4), wherein a backlash-eliminating protrusion is provided on either the inner surfaces of the recess portions or the outer surfaces of the pair of walls. 
     The lever-type connector of the above configuration can prevent the flexible arm portion from being deformed due to being undesirably pressed on before fitting the connector since the flexible arm portion of the lock portion is surrounded by the pair of the walls and the arm protection walls extending from these walls. 
     Furthermore, since the arm protection walls are extended so as to cover the flexible arm portion and, thereby, overlap upper portions of both sides of the flexible arm portion, in the event that the flexible arm portion is undesirably lifted up, deformation of the flexible arm portion can be prevented by bringing the two sides in contact with the arm protection walls. 
     In the lever-type connector of the above configuration, since the operating portion of the lever moved to the fitting completion position is disposed on the arm protection walls, even when a further load is applied in an effort to excessively rotate the lever after fitting the connector, no load will be applied to the flexible arm portion protected by the arm protection walls and deformation of the flexible arm portion can be prevented. 
     In the lever-type connector having the configuration described above in (3), when the lever is moved to the fitting completion position, the recessed portions of the operating portion are externally fitted to the pair of the walls on both sides of the lock portion without any gaps (a state of no gaps or pressurized contact). Therefore, it is possible to suppress backlash of the operating portion of the lever engaged and locked to the flexible arm portion of the lock portion in the fitting completion position. As a result, even if an external force such as vibration or shock is applied, the lever can be engaged and locked by the flexible arm portion, thus high fitting reliability with the mating connector can be achieved. 
     In the lever-type connector of the above configuration, when the lever is placed in the fitting completion position, the backlash-eliminating protrusions protruding from either the outer surfaces of the pair of walls or the inner surfaces of the recessed portions are compressed and deformed in a state where the recessed portions of the operating portion are pressed against the pair of walls. By backlash-eliminating protrusions which are easy to compress and deform, it is possible to easily suppress backlash of the operating portion of the lever engaged and locked to the lock portion in the fitting completion position. 
     According to the present invention, it is possible to provide a lever-type connector that protects a lock portion of a housing and obtains a high fitting reliability with a mating connector. 
     The present invention has been briefly described above. Furthermore, details of the present invention will be further clarified by reading about the forms for carrying out the invention (hereinafter referred to as “embodiments”) described below with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view illustrating a lever-type connector according to an embodiment of the present invention before being fitted to a mating connector viewed from a rear side, and  FIG. 1B  is an enlarged view thereof viewed in a direction of arrow A in  FIG. 1A . 
         FIG. 2  is a perspective view illustrating the housing shown in  FIG. 1 . 
         FIG. 3A  is a side view of the housing shown in  FIG. 2 , and  FIG. 3B  is a cross sectional view illustrating an inner surface of the side plate of the lever shown in  FIG. 1 . 
         FIGS. 4A and 4B  are enlarged views illustrating a main portion showing a side plate of the lever pivotally supported by a support shaft of the housing, in which  FIG. 4A  shows a state where the lever is in a temporary locking position, and  FIG. 4B  shows a state where the lever is in the fitting completion position. 
         FIG. 5  is a perspective view illustrating the lever-type connector shown in  FIG. 1  in a state where the housing is fitted in the mating housing and the lever has moved to and positioned at a fitting start position. 
         FIG. 6A  is a perspective view illustrating the lever-type connector shown in  FIG. 5  with the lever moved to and positioned at the fitting completion position, and  FIG. 6B  is an enlarged view thereof viewed in the direction of arrow B in  FIG. 6A . 
         FIGS. 7A and 7B  are explanation views that describe the movement of a locking protrusion and a cam boss in accordance with the rotation of the lever, wherein  FIG. 7A  shows a state before the housing is fitted to the mating connector, and  FIG. 7B  shows a state in which the housing is fitted in the mating connector and the cam boss is in contact with the cam groove. 
         FIGS. 8A and 8B  are views that describe the movement of the locking protrusion and the cam boss in accordance with the rotation of the lever, wherein  FIG. 8A  shows a state in which the housing is pushed into the mating connector and the lever is moved from the temporary locking position to the fitting start position, and  FIG. 8B  shows a state in which the lever has been moved to the fitting completion position. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 
       FIG. 1A  is a perspective view illustrating a lever-type connector  10  according to an embodiment of the present invention before being fitted to a mating connector  1  as viewed from a rear, and  FIG. 1B  is an enlarged view thereof viewed in a direction of arrow A in  FIG. 1A .  FIG. 2  is a perspective view illustrating the housing  20  shown in  FIG. 1 .  FIG. 3A  is a side view of the housing  20  shown in  FIG. 2 , and  FIG. 3B  is a cross sectional view illustrating an inner surface of the side plate of the lever shown in  FIG. 1 . 
     As illustrated in  FIGS. 1A to 3B , the lever-type connector  10  according to the present embodiment includes a housing  20  and a lever  50 . The lever-type connector  10  is fitted to the mating connector  1  by fitting the mating housing  2  and the housing  20  to each other. The lever  50  has a pair of side plates  51  arranged along surfaces of both sides  22  of the housing  20  and an operating portion  52  connecting the ends of the side plates  51 . The lever  50  is rotatable around an axis in the horizontal direction with respect to the housing  20 . 
     The lever  50  is rotated between a temporary locking position (see  FIG. 1A ) and a fitting completion position (see  FIG. 6A ). The housing  20  has a lock portion  24  for locking the operating portion  52  of the lever  50  on the upper surface  23  of the housing  20 . The lever  50  locks into the fitting completion position by the lock portion  24  when the operating portion  52  is engaged and locked to the lock portion  24 . The lever-type connector  10  is assisted in fitting to and detaching from the mating connector  1  by rotation of the lever  50 . That is, the lever-type connector  10  is an LIF (Low Insertion Force) connector that is fitted to the mating connector  1  with a low insertion force by operation of the lever  50 . 
     The housing  20  is made of insulating synthetic resin, and a front part  20   a  of the housing  20  is fitted to the mating housing  2  of the mating connector  1 . The housing  20  has a plurality of terminal accommodating chambers  21 . These terminal accommodating chambers  21  are formed along a direction of fitting with the mating connector  1 , and terminals (not shown) connected to electrical wires (not shown) are accommodated in the respective terminal accommodating chambers  21 . Electrical wires connected to terminals accommodated in the terminal accommodating chambers  21  are pulled out from a rear part  20   b  of the housing  20 . An electrical wire cover  28  is attached to the rear part  20   b  of the housing  20 , and the electrical wires pulled out from the rear part  20   b  of the housing  20  are covered with the electrical wire cover  28  and are bundled and pulled out in one direction (lateral direction in this example). By fitting the lever-type connector  10  into mating connector  1 , terminals accommodated in the terminal accommodating chambers  21  of the housing  20  are electrically connected to the terminals provided in the mating housing  2  of the mating connector  1 . 
     As shown in  FIGS. 2 and 3A , support shafts  25  protrude from the surfaces of both sides  22  of the housing  20 . The lever  50  has a pivot hole  55  in respective one of its side plates  51 , and the support shafts  25  of the housing  20  are respectively inserted through the pivot holes  55 . As a result, the lever  50  is rotatable about the support shafts  25  inserted through the pivot holes  55  of the side plates  51 . A locking piece  26  that extends rearward of the housing  20  with intersecting the support shaft axis is formed at the tip of each of the support shafts  25 . 
     In each of the side plates  51 , the pivot hole  55  has a shape corresponding to the outer shape of the locking piece  26 , so the locking piece  26  can only be inserted through each of the side plates  51  when the lever  50  is disposed between the temporary locking position and fitting completion stop position and the locking piece  26  is aligned with the shape of the pivot hole  55 . The locking piece  26  inserted into the pivot hole  55  prevents the side plate  51  from coming off, when the locking piece  26  is in a range corresponding to a locking recess portion  57  that is formed in the outer surface of the side plate  51 . 
     Furthermore, on the bottom surface of the locking recess portion  57  in the vicinity of the pivot hole  55 , a pressed protrusion  56  is formed. The side plate  51  is moved toward the side surface  22  by the pressed protrusion  56  that is pressed by the inner surface of the locking piece  26  when the lever  50  is moved to the fitting completion locking position. 
     As shown in  FIG. 4A , when the lever  50  is in the temporary locking position, the locking piece  26  of the support shaft  25  overlaps a part of the locking recess portion  57 . As a result, in a state in which the lever  50  is disposed at the temporary locking position, the locking recess portion  57  is locked to the locking piece  26 . Also, as shown in  FIG. 4B , even when the lever  50  is disposed at the fitting completion position, the locking piece  26  of the support shaft  25  overlaps a part of the locking recess portion  57 . As a result, in a state where the lever  50  is disposed at the fitting completion position, the locking recess portion  57  is locked to the locking piece  26 . 
     As shown in  FIG. 3A , guide grooves  47  are formed on both sides  22  of the housing  20  and open up toward the front part  20   a . The guide grooves  47  are formed along the front-rear direction of the housing  20 . When the housing  20  is fitted to the mating housing  2 , the cam bosses  5  and the guide protrusions  6  (see  FIG. 1A ) on both side surfaces of the mating housing  2  are inserted in the guide grooves  47 . 
     As shown in  FIG. 3B , a cam groove  77  is formed on the inner surface of the side plate  51  of the lever  50  facing the side surface  22  of the housing  20 . The cam groove  77  is open on the front side of the lever  50  in a state of being moved to the temporary locking position and extends obliquely downward toward the rear side of the lever  50 . When the housing  20  is fitted to the mating housing  2 , the cam bosses  5  of the mating housing  2  enter the cam grooves  77  (see  FIG. 7B ). Then, when the lever  50  is rotated from this state toward the fitting completion position, the cam groove  77  of the lever  50  rotates, and the cam boss  5  entering the cam groove  77  is retracted in the cam groove  77  (refer to  FIGS. 8A and 8B ). As a result, the housing  20  and the mating housing  2  are drawn to each other and fitted together. 
     On the inner surface of the side plate  51  of the lever  50 , a locking protrusion  73  is formed for locking the lever  50  to the temporary locking position with respect to the housing  20 . When the lever  50  is moved to the temporary locking position, the locking protrusion  73  is disposed in the guide groove  47  and is locked to the upper-edge portion of the guide groove  47  (see  FIG. 7A ). 
     On both sides  22  of the housing  20 , there are escape grooves  43  in which the locking protrusions  73  are in a non-contact state when the lever  50  rotates. The escape groove  43  is formed in an arc shape with the support shaft  25  as its center. On one end (the upper end in  FIG. 3A ) of the escape groove  43 , a final locking surface  44  is formed. The final locking surface  44  is a tapered surface that gradually becomes shallower toward the upper end portion of the escape groove  43 . 
     When the lever  50  is rotated toward the fitting completion position, the locking protrusion  73  goes over the upper-edge portion of the guide groove  47 , is guided into the escape groove  43 , and moves through the escape groove  43 . When the lever  50  is rotated, by way of the locking protrusion  73  on the inner surface of the side plate  51  of the lever  50  moving through the escape groove  43  on the side surface  22  of the housing  20 , the lever  50  smoothly rotates in a predetermined direction without the locking protrusion  73  coming into contact with the side surface  22  of the housing  20 . 
     When the lever  50  reaches the fitting completion stop position, the locking protrusion  73  of the lever  50  rides on the final locking surface  44  having a tapered surface and suppresses backlash of the lever  50  (see  FIG. 8B ). 
     As shown in  FIGS. 1A, 1B and 2 , the housing  20  has a lever-disengagement prevention portion  35 . The lever-disengagement prevention portion  35  is provided at the upper position on both sides of the housing  20 , and is formed so as to extend rearward along both sides  22  from the front part  20   a . The lever  50  has an upper-edge portion  61  and a vibration-suppressing protrusion  62  on a part of the side plate  51 . 
     In a state where the lever  50  is moved to the temporary locking position, the upper-edge portion  61  of the side plate  51  facing the lever-disengagement prevention portion  35  goes inside the lever-disengagement prevention portion  35  (see  FIG. 1 ). By way of the lever  50  moving to the temporary locking position, the upper-edge portion  61  is covered from the outside by the lever-disengagement prevention portion  35 , and the side plate  51  is prevented from being detached from the housing  20 . 
     In a state where the lever  50  is moved to the fitting completion position, the vibration-suppressing protrusion  62  goes inside the lever disengagement prevention portion  35  (see  FIG. 6 ). When the lever  50  is moved to the fitting completion position, the vibration-suppressing protrusion  62  of the side plate  51  is covered from the outside by the lever-disengagement prevention part  35  and the inner surface of the lever-disengagement prevention part  35  is pressed against the vibration-suppressing protrusion  62  thereby eliminating backlash of the side plate  51  with respect to the lever-disengagement prevention portion  35 . It is sufficient if the inner surface of the lever-disengagement prevention portion  35  is in contact with the vibration-suppression protrusion  62 . An inner face of the lever-disengagement prevention portion  35  need not be pressurized by the vibration-suppressing protrusion  62  as long as they are in a state in which there are no gaps. 
     As shown in  FIGS. 1A to 2 , the lock portion  24  provided on the upper surface  23  of the housing  20  has a flexible arm portion  27  and an engaging portion  29 . When the lever  50  is moved to the fitting completion position, the engaging portion  29  locks the lock portion  53  protruding from the operating portion  52 . As a result, the lock portion  53  of the lever  50  is locked to the engaging portion  29  of the lock portion  24  so that rotation of the lever  50  is restricted with respect to the housing  20 , which is so called as a locked state. 
     A pair of walls  41  stand upright on the upper surface  23  of the housing  20  and are arranged on both sides of the lock portion  24  for locking the operating portion  52 . Further, on the upper edges of the walls  41 , arm protection walls  40  extend inward so as to cover both sides of the flexible arm portion  27 . Accordingly, since the lock portion  24  is surrounded by the pair of walls  41  and the arm protection wall  40 , the flexible arm portion  27  is prevented from deformation due to being undesirably pressed on before fitting the connector. 
     For example, during packing before fitting to the mating connector  1  or during transportation, it is difficult for electrical wires to be caught by the flexible arm portion  27  surrounded by the pair of walls  41  and arm protection wall  40 , and the flexible arm portion  27  can not be lifted up by any electrical wire that gets caught. 
     Further, as shown in  FIG. 1B , since the arm protection walls  40  are extended so as to overlap upper portions of both sides of the flexible arm portion  27 , even in the event that the flexible arm portion  27  is undesirably lifted up, the arm protection walls  40  will come into contact with both sides of the flexible arm portion  27  and restrict the upward deformation of the flexible arm portion  27 , thereby, preventing deformation of the flexible arm portion  27 . 
     Next, a case where the lever-type connector  10  is fitted to the mating connector  1  will be described. 
       FIGS. 7A to 8B  are views for describing the movement of the locking projection  73  and cam boss  5  in accordance with the rotation of the lever  50 . 
     As shown in  FIG. 7A , the housing  20  of the lever-type connector  10  in a state where the lever  50  is temporarily engaged in the temporary locking position is fitted to the mating housing  2  of the mating connector  1 . 
     Here, the operator places the thumb against the vicinity of the rear edge of the upper surface  23  and pushes the housing  20  into the mating housing  2  (see  FIG. 1A ). With the flexible arm portion  27  of the lock portion  24  being surrounded by the pair of walls  41  and the arm protection wall  40 , any pushing force on the housing  20  is applied to the pair of walls  41  and the arm protection wall  40 , without being applied to the flexible arm portion  27 . Accordingly, the flexible arm portion  27  is prevented from being undesirably pressed and deformed. 
     Next, as shown in  FIG. 7B , when the housing  20  is fitted to the mating housing  2  and the cam bosses  5  and the guide protrusions  6  of the mating housing  2  are inserted into the guide grooves  47  of the housing  20 , each of the cam bosses  5  abuts on respective one of the cam grooves  77  of the lever  50 . When the housing  20  is pushed into the mating housing  2 , each of the cam bosses  5  of the mating housing  2  is pushed into the respective one of the cam grooves  77  of the lever  50 , and the lever  50  is rotated toward the fitting start position by the pushing force. From this, each of the locking protrusions  73  of the side plates  51  of the lever  50  is released from engagement with respective one of the upper edge portions of the guide grooves  47  and enters corresponding one of the escape grooves  43 . 
     Then, as shown in  FIG. 8A , the lever  50  temporarily engaged in the temporary locking position is moved to the fitting start position. In this state, the operating portion  52  of the lever  50  is held by the operator and the lever  50  is rotated to the fitting completion position. At this point, the operator can shift the thumb, which is in the vicinity of the rear edge of the upper surface  23 , to the operating portion  52  of the lever  50 , and rotates the lever  50  without having to change the housing  20 . In this way, good operability is achieved. 
     When the lever  50  is rotated to the fitting completion position, each of the cam bosses  5  of the mating housing  2  is retracted into the respective one of the cam grooves  77  of the lever  50 , and as shown in  FIG. 8B , the housing  20  and the mating housing  2  are fitted to each other, the lever-type connector  10  is fitted to the mating connector  1 , and the terminals are electrically connected. 
     When the lever  50  is moved to the fitting completion position, the lock portion  53  of the operation portion  52  is engaged and locked to the engaging portion  29  of the lock portion  24 , and the rotation of the lever  50  relative to the housing  20  is restricted in the locked state. 
     As shown in  FIG. 6B , in the lever-type connector  10  of the present embodiment, the operating portion  52  of the lever  50  moved to the fitting completion position is disposed above the arm protection wall  40 . Therefore, even when a further load is applied in an effort to excessively rotate the lever  50  after fitting the connector, no load will be applied to the flexible arm portion  27  protected by the pair of walls  41  and arm protection wall  40  and deformation of the flexible arm portion  27  can be prevented. 
     Furthermore, there are recessed portions  71  which can externally fit the pair of walls  41  in the operating portion  52  of the lever  50 . When the lever  50  is moved to the fitting completion position, the inner surfaces  71   a  of the recessed portions  71  contact the opposing outer surfaces  41   a  of the pair of walls  41 , respectively. That is, the recessed portions  71  of the operating portion  52  are externally fitted to the pair of walls  41  without gaps (a state of no gaps or pressurized contact). With backlash-eliminating protrusions  72  protruding inward and being provided on the inner surfaces  71   a  of the recessed portions  71  of the present embodiment, the backlash-eliminating protrusions  72  are compressed and deformed and the recessed portions  71  of the operating portion  52  are brought into pressurized contact with the pair of walls  41  (see  FIG. 1A  and  FIG. 6B ). As shown by the dashed line in  FIG. 1A , backlash-eliminating protrusions  42  protruding outward can also be provided on the outer surfaces  41   a  of the pair of walls facing the inner surfaces  71   a  of the recessed portions  71 . 
     Therefore, backlash of the operating portion  52  of the lever  50  that is engaged and locked to the lock portion  24  in the fitting completion position can be further suppressed. As a result, even if an external force such as vibration or shock is applied, the lever  50  can be engaged and locked by the lock portion  24 , thus high fitting reliability with the mating connector  1  can be achieved. 
     When the lever  50  is moved to the fitting completion position, the vibration-suppressing protrusion  62  of the side plate  51  enters the inside of the lever-disengagement prevention portion  35 . Consequently, the vibration-suppressing protrusion  62  of the side plate  51  is covered from the outside by the lever-disengagement prevention portion  35  and the inner surface of the lever disengagement prevention portion  35  is brought into pressurized contact with the vibration-suppressing protrusion  62 . As a result, backlash of the side plate  51  with respect to the lever-disengagement prevention portion  35  of the lever  50  is suppressed. 
     Further, when the lever  50  is rotated to the fitting completion position, the locking protrusion  73  protruding from the inner surface of each of the side plate  51  passes through the corresponding one of the escape grooves  43  and rides on the corresponding final locking surface  44  having the tapered surface. As a result, backlash of the side plate  51  with respect to the side surface  22  of the housing  20  is suppressed in the lever  50 . 
     When the lever  50  is then rotated to the fitting completion position, the pressed protrusion  56  projecting from the outer surface of the side plate  51  is pressed toward the side surface  22  by the inner surface of the locking piece  26  of the support shaft  25 . The backlash of the side plate  51  with respect to the support shaft  25  of the housing  20  is suppressed in the lever  50 . 
     In this way, in the lever-type connector  10  of the present embodiment, the operating portion  52  of the lever  50  is held and the lever  50  is rotated by the operator, thereby the insertion force of the housing  20  applied to the mating housing  2  is assisted through the cam mechanism constituted by the cam groove  77  and cam boss  5 . 
     As described above, in the lever-type connector  10  according to the present embodiment, when the housing  20  is fitted into the mating housing  2  and the lever  50  at the fitting start position is rotated and moved to the fitting completion position, the housing  20  is fitted to the mating housing  2  and the lever  50  is engaged and locked to the lock portion  24 . Since the flexible arm portion  27  of the lock portion  24  is surrounded by the pair of walls  41  and the arm protection walls  40  extending to the walls  41 , it is prevented from deformation due to being undesirably pressed on before fitting the connector. 
     Furthermore, since the arm protection walls  40  are extended so as to cover and, thereby, overlap upper portions of both sides of the flexible arm portion  27 , in the event that the flexible arm portion  27  is undesirably lifted up, deformation of the flexible arm portion  27  can be prevented by bringing the two sides in contact with the arm protection walls  40 . 
     Since the vibration suppressing protrusions  62 , which are a part of the side plates  51  of the lever  50 , are covered from the outside by the lever-disengagement prevention portions  35  provided on both sides of the housing  20 , disengagement of the side plate  51  from the housing  20  is prevented in the lever  50  that is engaged and locked to the lock portion  24  in the fitting completion position. As a result, even if an external force such as vibration or shock is applied to the lever  50 , the lever  50  can be engaged and locked by the lock portion  24 , thus high fitting reliability with the mating connector  1  can be achieved. 
     When the lever  50  is moved to the fitting completion position, the inner surface of the lever-disengagement prevention portion  35  is pressed against the vibration suppressing protrusions  62  provided on the side plate  51  of the lever  50 . The lever  50 , in which the side plates  51  do not rattle with respect to the lever disengagement prevention portion  35 , does not generate abnormal noise even when vibrations are applied. 
     Moreover, when the lever  50  is moved to the fitting completion position, the recessed portions  71  of the lever  50  are externally fitted to the walls  41  on both sides of the lock portion  24  without any gaps. Therefore, backlash of the operating portion  52  of the lever  50  that is engaged and locked to the lock portion  24  in the fitting completion position can be further suppressed. As a result, even if an external force such as vibration or shock is applied, the lever  50  can be engaged and locked by the lock portion  24 , thus high fitting reliability with the mating connector  1  can be achieved. Furthermore, there are backlash-eliminating protrusions  72  projected from the inner surfaces  71   a  of the recessed portions  71 . When the lever  50  is placed in the fitting completion position, the backlash-eliminating protrusions  72  protruding from the inner surfaces  71   a  of the recessed portions  71  are compressed and deformed in a state where the recessed portions  71  of the operating portion  52  are pressed against the pair of walls  41 . Therefore, with the simple backlash-eliminating protrusions  72  that are easily compressed and deformed, backlash of the operating portion  52  of the lever  50  that is engaged and locked to the lock portion  24  in the fitting completion position can be easily suppressed. 
     Furthermore, in the lever-type connector  10  according to the present embodiment, the locking protrusions  73  on the inner surfaces of the side plates  51  of the lever  50  can lock the lever  50  to the housing  20  in the temporary locking position. Therefore, it is possible to prevent careless rotation of the lever  50  before fitting to the mating connector  1  and eliminate complicated operations in returning the carelessly rotated lever  50  to the temporary locking position, thus, making it possible to smoothly perform the fitting to the mating connector  1 . 
     When rotating the lever  50 , by way of the locking projection  73  on the inner surface of the side plate  51  of the lever  50  passing through the escape groove  43  formed in the side surface  22  of the housing  20 , the lever  50  is smoothly pivoted in a predetermined direction without the locking protrusion  73  coming in contact with the side surface  22  of the housing  20 . Then, when the lever  50  is moved to the fitting completion position, the locking protrusion  73  of the lever  50  rides on the locking surface  44  of the escape groove  43  and suppresses backlash of the lever  50 . As a result, even if an external force such as vibration or shock is applied, the lever  50  can be engaged and locked by the lock portion  24  more securely, thus high fitting reliability with the mating connector  1  can be achieved. 
     Further, when the lever  50  is moved to the fitting completion position, the inner surface of the locking piece  26  of the support shaft  25 , projecting from both sides  22  of the housing  20 , presses the pressed protrusion  56 , protruding from the bottom surface of the locking recess portion  57  formed in the vicinity of the pivot hole  55  in the side plate  51  of the lever  50 , against the side surface  22 . Therefore, in the side plates  51  of the lever  50 , backlash of the support shaft  25  of the housing  20  is suppressed, and generation of noise from vibrations are prevented. 
     Since the locking protrusion  73  of the lever  50  is disposed inside the escape groove  43  when the lever  50  is in the middle of a rotation, the locking projection  73  does not receive the counter force from the side surface  22  of the housing  20 . Therefore, the side plate  51  cannot float away. Also, when the opening of the pivot hole  55  in the middle rotation of the lever  50  overlaps and is aligned with the locking piece  26  of the support shaft  25 , it is not possible for the support shaft  25  to come out of the pivot hole  55 . 
     The present invention is not limited to the embodiment described above, and suitable modifications, improvements and so on can be made. Furthermore, the material, shape, dimensions, number, disposition, etc. of each component in the above embodiment is not limited as long as it can achieve the present invention. 
     Here, characteristics of the embodiment of the lever-type connector according to the present invention described above will be briefly summarized below in [1] to [4]. 
     [1] A lever-type connector ( 10 ), including:
         a housing ( 20 ) configured to be inserted and removed with respect to a mating housing ( 2 ) of a mating connector ( 1 );   a lever ( 50 ), pivotally mounted on the housing, and that is pivotally operable between a temporary locking position and a fitting completion position of the lever, the lever including:
           a pair of side plates ( 51 ) arranged along surfaces on both sides ( 22 ) of the housing; and   an operating portion ( 52 ) that connect ends of the side plates; and   
           a lock portion ( 24 ) provided on the housing, and locks the lever positioned at the fitting completion position,   wherein the housing is configured to be fitted to the mating housing by rotating the lever from a fitting start position to the fitting completion position; and   wherein the housing has a pair of walls ( 41 ) that are provided at both sides of the lock portion for engaging and locking the operating portion of the lever; and   wherein arm protection walls ( 40 ) are provided on upper edges of the pair of walls respectively with extending inward so as to cover both sides of the flexible arm portion ( 27 ) of the lock portion.       

     [2] The lever-type connector ( 10 ) according to the item [1], wherein the operating portion is disposed above the arm protection walls when the lever is positioned at the fitting completion position. 
     [3] The lever-type connector ( 10 ) according to items [1] or [2], wherein the arm protection walls ( 40 ) extend in parallel with an upper surface of the housing ( 20 ) so as to close to each other. 
     [4] The lever-type connector ( 10 ) according to any one of items [1] to [3], wherein recessed portions ( 71 ) that externally fit the pair of walls are formed on the operating portion; and
         wherein each of inner surfaces ( 71   a ) of the recessed portions contact corresponding one of the outer surfaces ( 41   a ) of the pair of walls which faces corresponding one of the inner surfaces ( 71   a ) when the lever is positioned at the fitting completion position.       

     [5] The lever-type connector ( 10 ) according to the item [4], wherein a backlash-eliminating protrusion ( 71 ,  42 ) is provided on either the inner surfaces ( 71   a ) of the recessed portion ( 71 ) or the outer surfaces ( 41   a ) of the pair of walls ( 41 ).