You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This U.S. National stage application claims priority under 35 U.S.C. 119(a) to Japanese Patent Application No. 2012-240515, filed in Japan on Oct. 31, 2012, the entire contents of Japanese Patent Application No. 2012-240515 are hereby incorporated herein by reference. 
     BACKGROUND 
     Field of the Invention 
     The present invention relates to a driving device for opening and closing an opening/closing body arranged at an opening of a vehicle. More specifically, the present invention relates to a driving device for opening and closing a back door or a trunk door (trunk lid) of a vehicle such as a car, etc. 
     Background Information 
     Many of vehicles such as cars, etc. include opening/closing bodies such as back doors or trunk doors (trunk lids) that open in a flip-up direction from back openings. In order to increase accessibilities, improve security, and/or etc., a number of vehicles including opening/closing apparatuses to open and close the open/close bodies with an electric power has been increasing. 
     The opening/closing body, which opens in the flip-up direction, requires a space for opening and closing operations, and sometimes needs to be stopped at an arbitrary position in order to prevent the door in opening/closing operations from touching an obstacle and/or a person or reduce the amount of the opening of the opening/closing body due to strong wind and/or rain. 
     There is for example a driving devices for opening and closing the opening/closing in which a ball screw mechanism, which converts a rotation of an electric motor to a linear movement, is used. The driving devices for opening and closing in which such ball screw mechanism is used can stop the opening/closing body at arbitrary positions with a lock pin that engages with a rotation-side member of the ball screw mechanism in accordance with a movement of a plunger of a solenoid (See JP 2010-270886 A, for example). 
     SUMMARY 
     In the above-described driving device for opening and closing, an impulsive noise is generated when a movable iron core, which is the plunger of the solenoid, is attracted electromagnetically and collides with a fixed iron core in a casing. Otherwise, an impulsive noise is generated when the lock pin engages with the rotation-side member of the ball screw mechanism in response to the movement of the plunger. 
     Since these impulsive noises are loud enough to be heard by a user and they are metallic clanks with higher tones, they make the vehicle less luxury and give the user a negative feeling such that the user feels uncomfortable to these noises. In addition, if a silence solenoid is used, the problem arises that the solenoid cannot generate a power large enough for the opening/closing apparatus used in a vehicle. 
     The object of the present invention is to reduce a noise that influences negatively to a user, such as a noise that makes the vehicle less luxury, by reducing an impulsive noise generated in the operation of a driving device for opening and closing or changing the tone range of the impulsive noise. 
     Aspects of the present invention to solve the problem will be described below. These aspects can be combined arbitrarily as desired. 
     A driving device for opening and closing according to one aspect of the present invention includes a motor, a rod member, a clutch, a nut member, a connection member, and a rotation inhibiting means. Male threads are formed on the outer surface of the rod member. The clutch is configured to transmit or cut a rotation power of the motor to the rod member. The nut member is screwed with the rod member and configured to move linearly by the rotation of the rod member. The connection member is configured to open and close an opening/closing body by the linear movement of the nut member. The rotation inhibiting means is configured to inhibit the rotation of the rod member. The rotation inhibiting means has an engagement member, an engaged portion, a solenoid, and a link member. The engagement member is configured to move between an engagement position and an engagement release position. The engaged portion is arranged on the rod member and configured to inhibit the rotation of the rod member by engaging with the engagement member. The solenoid is configured to move the engagement member. The link member is configured to move the engagement member in accordance with the movement of the solenoid. The link member has a mechanical structure that is configured to reduce a vibration by changing a vibration condition of the engagement member. 
     According to the driving device for opening and closing having the above-described structure, since the rotation inhibiting means, which has the engagement member that is configured to move between the engagement position and the engagement release position, and the engaged member that is configured to inhibit the rotation of the rod member by engaging with the engagement member, engages mechanically, the opening/closing body can be stopped securely at arbitral positions without reducing the durability of the clutch. In this case, the existence of the link member that is configured to move the engagement member in accordance with the movement of the solenoid can reduce a noise generated due to the movement of the solenoid or change the tone interval by changing the vibration condition of the engagement member to reduce the vibration, thus an uncomfortable feeling of the user can be reduced. 
     Here, the engagement member can be formed in a convex shape and to move in a direction perpendicular to an axis direction of the rod member. In addition, the engaged portion can be formed as a plurality of concaves arranged on an outer periphery of the rod member, the concaves being provided defining a predetermined space in a rotation direction of the rod member with each other. 
     In this case, the mechanical engagement of the engagement member with the engaged portion can stop the opening/closing body securely at arbitral positions. 
     The mechanical structure can be formed as a movement inhibiting portion that is configured to apply a force to the link member in the direction different from the direction of the movement of the link member generated by the movement of the solenoid. The movement inhibiting portion can reduce the noise generated due to the movement of the solenoid or change the tone range of the noise by applying the force to the link member in the direction different from the direction of the movement of the link member. 
     The movement inhibiting portion can be a weight that is arranged in the vicinity of an end portion of an elongating member that is attached to the link member. By arranging the weight in the vicinity of the end portion of the elongating member, due to the gravitational acceleration of the weight, the force can be applied to the link member in the direction different from the direction of the movement of the link member generated by the movement of the solenoid. Consequently, the above-described effect can be achieved. 
     In the present invention, the engagement of the engaged member with the engagement member can inhibit the rotation of the rod member and stop the opening/closing body at the intermediate position. In this case, since the mechanical structure, which inhibits a vibration that changes the vibration condition of the engagement member, is arranged in the link member that moves the engagement member in accordance with the movement of the solenoid, the uncomfortable feeling of the user can be reduced by reducing the generated impulse noise or changing the tone range of the impulse noise. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a back portion of a vehicle where a driving device for opening and closing according to the present invention is used; 
         FIG. 2  is a front view of a driving device for opening and closing according to the present invention; 
         FIG. 3  is a cross sectional view of a driving device for opening and closing illustrated in  FIG. 2  when cut with an III-III line; 
         FIG. 4  is a front view of one example of an engagement member; 
         FIG. 5  is a side view of the engagement member illustrated in  FIG. 4 ; 
         FIG. 6  is a view of one example of an engaged member seen from the axis direction; 
         FIG. 7  is a cross sectional view of the engagement member illustrated in  FIG. 6  cut along the axis; 
         FIG. 8  is a cross sectional view of a part of a driving device for opening and closing in which an engagement member is not engaged with an engaged member; 
         FIG. 9  is a cross sectional view of a part of a driving device for opening and closing in which an engagement member is engaged with an engaged member; 
         FIG. 10  is a cross sectional view of the rotation inhibiting unit illustrated in  FIG. 8  cut with an X-X line; and 
         FIG. 11  is a cross sectional view of the rotation inhibiting unit illustrated in  FIG. 9  cut with an XI-XI line. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     In the following, an embodiment of the present invention will be described with reference to accompanying drawings.  FIG. 1  is a schematic view illustrating a back portion of a vehicle where a driving device for opening and closing according to the present invention is used.  FIG. 2  is a front view of a driving device for opening and closing according to the present invention. 
     A driving device for opening and closing A shown in  FIG. 1  is a device that is arranged inside a vehicle Cr and opens and closes an opening/closing body Dr that is rotatably connected to a supporting point Fc that is arranged at the upper end of a back opening portion of the vehicle Cr. It should be noted that, in the vehicle Cr, the opening and closing of the opening/closing body Dr is performed only by the driving device for opening and closing A. However, not limited to this, the driving device for opening and closing A and a damper that helps the movement of the opening/closing body Dr can be used. In the following, the driving device for opening and closing A according to the present invention will be described with reference to the drawings. 
     As shown in  FIG. 2 , the driving device for opening and closing A according to the present invention includes a motor M, a clutch  1 , a rod member  2 , a nut member  3 , a connection member  4 , and a rotation inhibiting unit  5  (a rotation inhibiting means). The rotation inhibiting unit  5  has an engagement member  51  and an engaged member  52 . In the following, the details of each element of the driving device for opening and closing A according to the present invention will be described. It should be noted that, in the driving device for opening and closing A shown in  FIG. 2 , for ease of understanding, the angle of a part of the motor M is changed from the actual angle and the cross sectional view of the part is shown in  FIG. 2 . 
     As shown in  FIG. 2 , the clutch  1  is an electromagnetic clutch that is arranged inside a housing  10 . The clutch  1  has a well-known structure and has an input shaft  11  and an output shaft  12  as shown in  FIG. 2 . The clutch  1  has a coil (not shown) inside and, when electric current is flown in the coil, the input shaft  11  and the output shaft  12  are connected to transmit a rotation power (torque). On the other hand, when electric current is not flown in the coil, the input shaft  11  is isolated from the output shaft  12  to stop the transmission of the rotation power (torque). 
     A worm wheel  111 , which is geared with a worm gear Wg attached to a rotation shaft of the motor M, is fixed to the input shaft  11  of the clutch  1 . Thus, the rotation power generated by the rotation shaft of the motor M is transmitted to the input shaft  11  via the worm gear Wg and the worm wheel  111 . It should be noted that the reduction ratio in transmitting the rotation power from the motor M to the input shaft  11  can be adjusted by adjusting shapes of the worm gear Wg and the worm wheel  111 . In  FIG. 2 , for ease of understanding, the rotation shaft of the motor M is shown in the direction perpendicular to the paper face of  FIG. 2 , however, the actual rotation shaft extends from the center of the motor M. 
     The output shaft  12  of the clutch  1  is connected to the rod member  2  via a joint member  6 . The joint member  6  has a clutch engagement portion  61  into which the output shaft  12  of the clutch  1  is engaged and a rod fixing portion  62  that fixes the rod member  2 . The clutch engagement portion  61  is a cylindrical member and the output shaft  12  of the clutch  1  is inserted inside the clutch engagement portion  61 . A concave spline (not shown in the Figure) that protrudes in the circumferential direction and extends in parallel to the rotation axis is formed on the outer periphery of the output shaft  12  of the clutch. In addition, the clutch engagement portion  61  has a concave groove (not shown in the Figure) where the spline is engaged on its inner periphery. Thus, if the output shaft  12  rotates, the rotation power of the output shaft  12  is transmitted to the joint member  6  due to the engagement of the spline with the concave groove. 
     As shown in  FIG. 2 , the rod member  2  is rotatably arranged inside a guide rail  20 . The rod member  2  is a columnar member and has a cylindrical connection portion  21  that is formed at one end, a supported portion  22  that is formed at the opposite end to the connection portion  21 , and a screw portion  23  that is a part between the connection portion  21  and the supported portion  22 . 
     The guide rail  20  is the member that is formed by folding a metal plate in a U-shape or in a channel-with-limb shape. As shown in  FIG. 2 , an opening  202 , which continues in the longitudinal direction, is formed on the side surface of the guide rail  20 . In addition, a set plate  201  is attached to the longitudinal tip of the guide rail  20  and a bracket  203  which is attached to the housing  10  of the clutch  1  is fixed to the opposite end. The connection portion  21  is rotatably supported by the bracket  203  via a bearing Brg and the supported portion  22  is rotatably supported by the set plate  201 . 
     Thus, since both end portions (the connection portion  21  and the supported portion  22 ) of the rod member  2  are rotatably supported by the bracket  203  and the set plate  201  that are arranged at both ends of the guide rail  20 , the rod member  2  is rotatably supported inside the guide rail  20 . Then, the bracket  203  is fixed to the housing  10  by a screw. 
     The connection portion  21  is inserted and fixed into a rod fixing portion  62  that is a concave hole formed in the joint member  6 . Since the joint member  6  is connected to the output shaft  12  of the clutch  1 , the connection portion  21  is connected to the output shaft  12  via the joint member  6 . In this case, it is preferable that the rotation center of the output shaft  12  of the clutch  1  coincides in high accuracy with the rotation center of the rod member  2 . For this, for fixing the rod fixing portion  62  and the connection portion  21 , any fixing methods that can inhibit the misalignment of the shafts, such as press fitting, welding, the connection by using a key, and etc., can be used. It should be noted that, in the driving device for opening and closing A according to the present invention, the fixing method in which the rod fixing portion  62  and the connection portion  21  are crimped (caulked) by applying a pressure from outside of the rod fixing portion  62  into which the connection portion  21  is inserted. 
     In addition, as shown in  FIG. 2 , other than the rod fixing portion  62  of the joint member  6 , the bearing Brg and an engaged member  52  of the rotation inhibiting unit  5  are attached to the connection portion  21 . The connection portion  21  is connected with the engaged member  52  with a key  500 , and a key groove  211  (see  FIG. 7 ) in which the key  500  is inserted is formed on the outer periphery of the connection portion  21 . It should be noted that the connection method of the engaged member  52  and the connection portion  21  is not limited to the method in which the key is used and the connection may be achieved by press fitting, welding, or etc. The bearing Brg is a well-known ball bearing, fixed to the bracket  203 , and rotatably supports the connection portion  21  of the rod member  2 . 
     The supported portion  22  is rotatably inserted into the concave hole that is formed in the set plate  201  that is attached to the tip of the guide rail  20 . Since the supported portion  22  is supported by the set plate  201 , the fluctuation of the tip side of the rod member  2  is inhibited and the deflection of the rod member  2  is inhibited. It should be noted that, in the driving device for opening and closing A shown in  FIG. 2 , the supported portion  22  is only inserted into the concave hole, however the supported portion  22  may be attached via a ball bearing. 
     It should be noted that, in the driving device for opening and closing A shown in  FIG. 2 , the connection portion  21  and the supported portion  22  are cylinders with smaller outer diameter than that of the screw portion  23 , however not limited to this, they may be cylinders with larger outer diameter than that of at least the screw portion  23 . Since the connection portion  21  and the supported portion  22  with smaller outer diameter than that of the screw portion  23  are easier to produce when the rod member  2  is produced by machining a cylindrical metal bar, in the driving device for opening and closing A, the outer diameter of the connection portion  21  and the supported portion  22  is set smaller than that of the screw portion  23 . Male threads are formed on the outer periphery of the screw portion  23  and screwed with later-described female-thread portion  31  of the nut member  3 . 
       FIG. 3  is a cross sectional view of the driving device for opening and closing illustrated in  FIG. 2  when cut with an line. In  FIG. 3 , the cross section of the left half of the nut member  3  is shown. 
     As shown in  FIG. 3 , the nut member  3  has a female-threaded portion  31 , a lining  32 , and a stud portion  33 . The female-threaded portion  31  is screwed with the male threads of the screw portion  23 . The lining  32  touches the inside of the guide rail  20 . The stud portion  33  protrudes from the opening  202  formed in the guide rail  20  and rotatably supports the connection member  4 . 
     The female-threaded portion  31  is formed separately from a main body of the nut member  3  and fixed so as to pass through a central portion of the main body of the nut member  3 . Since the female-threaded portion  31  is screwed with the screw portion  23 , the female-threaded portion  31  is moved linearly in the direction along the axis of the rod member  2  by the rotation of the rod member  2 . Thus, the nut member  3  having the female-threaded portion  31  is guided by the rod member  2  and the guide rail  20 , and is moved in the direction along the axis of the rod member  2 . It should be noted that the female-threaded portion  31  may be female threads formed integrally with the main body of the nut member  3 . 
     Since the female-threaded portion  31  touches the male-threaded part of the screw portion  23 , they are greased in order to reduce the friction between the female-threaded portion  31  and the male-threaded part of the screw portion  23 . Thus, the wear and the heat generation of the female-threaded portion  31  and/or the male-threaded part of the screw portion  23  can be reduced. In addition, the electric power required to drive the motor M can also be reduced because the energy loss due to the friction is small. 
     It should be noted that the part where the female-threaded portion  31  touches the male-threaded part of the screw portion  23  may be lubricated by lubricant other than grease, and no lubricant may be used if the female-threaded portion  31  and/or the screw portion  23  are made of materials with smaller friction. 
     In addition, the lining  32  inhibits backlash and torsion of the nut member  3  by touching the guide rail  20  when the nut member  3  moves. By greasing between the lining  32  and the guide rail  20 , the wear of the lining  32  and/or the guide rail  20  can be reduced. 
     It should be noted that the lubrication of the lining  32  with lubricants such as grease can be omitted if the lining  32  is made of materials with smaller coefficients of friction such as a fluorine-based resin. In addition, by making the lining  32  easy to attach or detach, the replacement of the lining  32  due to the wear can be easy. Thus, even if the nut member  3  shakes and/or distorts, the backlash and/or torsion of the nut member  3  can be adjusted by replacing only the lining  32 , consequently, the process can be reduced in comparison with replacing the whole of the nut member  3 . 
     The connection member  4  is the member that performs an opening/closing operation of the opening/closing body Dr by the linear movement of the nut member  3 . The connection member  4  is a long-bar-like member, one end of the connection member  4  is rotatably supported by the stud portion  33  and another end is rotatably supported by the opening/closing body Dr. The opening/closing body Dr and the driving device for opening and closing A form a link mechanism, the linear movement of the nut member  3  pushes (pulls) the opening/closing body Dr via the connection member  4 , and the opening/closing body Dr opens or closes around the supporting point Fc. The details of the opening/closing operation of the opening/closing body Dr will be described later. 
     The rotation inhibiting unit  5  stops the movement of the nut member  3  by inhibiting the rotation of the rod member  2 .  FIG. 4  is a front view of one example of the engagement member.  FIG. 5  is a side view of the engagement member illustrated in  FIG. 4 .  FIG. 6  is a view of one example of the engaged member seen from the axis direction.  FIG. 7  is a cross sectional view of the engagement member illustrated in  FIG. 6  cut along the axis. 
     As shown in  FIG. 2  and  FIG. 4 , the rotation inhibiting unit  5  has a case  50  that is hollow and parallelepiped, the engagement member  51  that is arranged such that it can reciprocate linearly inside the case  50 , the engaged member  52  that is attached to the connection portion  21  of the rod member  2 , a solenoid  53  that outputs the driving power to move the engagement member  51 , and a link arm  54  (one example of a link member) that connects the engagement member  51  with the solenoid  53  and transmits the movement of the solenoid  53  to the engagement member  51 . 
     The case  50  is fixed to the guide rail  20  such that the engagement member  51  can pass through a through-hole  200  that is formed in the vicinity of the end portion of the guide rail  20  at the clutch  1  side. It should be noted that the case  50  is fixed to the guide rail  20  such that the engagement member  51  can move in the direction perpendicular to the direction of the central axis of the rod member  2 . In addition, the case  50  has a movement guide  501 , which guides the movement of the engagement member  51 , and a supporting shaft  502 , which rotatably supports the link arm  54 . 
     The engagement member  51  can move between an engagement position P 2  and an engagement release position P 1 , as described later. As shown in  FIG. 4  and  FIG. 5 , the engagement member  51  is the cylindrical member that has an engagement portion  511 , a concave groove  512  that is formed at the side opposite to the engagement portion  511 , and a supporting shaft  513  that has also the concave groove  512 . 
     The engagement portion  511  has two inclined planes that are arranged such that they sandwich the central axis. The two inclined planes of the engagement portion  511  are formed in a convex shape such that they approach each other as they extend to the tip and these two inclined planes have the same angle of inclination as that of side walls of an engagement concave portion  523  which will be described later. 
     The concave groove  512  is the groove that passes through the engagement portion  511  in the radial direction, and the supporting shaft  513  is arranged such that it crosses a part of the concave groove  512 . As shown in  FIG. 4  and  FIG. 5 , the supporting shaft  513  is arranged such that it crosses (at right angles) the concave groove  512  and the supporting shaft  513  passes through the engagement member  51 . The supporting shaft  513  passes through an engagement portion connection hole  543  of the link arm  54  which will be described later. It should be noted that the shape of the engagement member  51  is not limited to cylinder, and the shape may be a column with a polygonal (hexagonal, for example) cross section. 
     The engaged member  52  is the member that inhibits the rotation of the rod member  2  by engaging with the engagement member  51 . As described above, the engaged member  52  is arranged on the outer periphery of the rod member  2  and fixed to the connection portion  21 . As shown in  FIG. 6  and  FIG. 7 , the engaged member  52  is a cylindrical member and has a through-hole  521 , a through-groove  522 , and engagement concave portions  523 . The connection portion  21  of the rod member  2  passes through the through-hole  521 . The through-groove  522  is formed on the inner surface of the through-hole  521  and passes through between both end portions in the axis direction. The engagement concave portions  523  are the concave portions that are arranged in the rotation direction of the rod member  2  while each defining the predetermined spaces between each other. 
     It should be noted that five engagement concave portions are formed in the circumferential direction, however the number of the engagement concave portions is not limited to this, more engagement concave portions may be formed, or less engagement concave portions may be formed. Although it needs more processes and takes more time to form larger numbers of the engagement concave portions, larger numbers of the engagement concave portions can adjust the stopping angle of the rod member  2  in higher accuracy. Although it needs less processes and takes less time to form smaller numbers of the engagement concave portions, smaller numbers of the engagement concave portions reduces the accuracy of the stopping angle of the rod member  2 . In addition, although the engaged member  52  is produced as a separated member from the rod member  2  and is attached to the rod member  2  in the driving device for opening and closing A, the engaged member  52  may be formed integrally with the rod member  2 . 
     The engaged member  52  is attached to the connection portion  21  as follows. First, the key  500  is inserted into the key groove  211  of the connection portion  21 . Since the key  500  is a parallelepiped member and the key groove  211  is formed in parallel to the axis of the rod member  2 , the key  500  inserted into the key groove  211  is arranged in parallel to the axis of the rod member  2 . The engaged member  52  is attached to the connection portion  21  such that the key  500  is fitted with the through-groove  522  of the engaged member  52 . As such, since the key  500  engages with both the key groove  213  and the through-groove  522  in the circumferential direction, the movement of the engaged member  52  in the circumferential direction with respect to the rod member  2  can be inhibited. 
     The solenoid  53  is the apparatus that moves the engagement member  51 . As shown in  FIG. 2 , the solenoid  53  is the actuator that drives a movable pin  531  by electric power. The solenoid  53  is a self-holding solenoid and holds the position of the movable pin  531  when the movable pin  531  is at the protruded position or the retracted position even if the electric power is cut. A link pin  532 , which passes through a solenoid connection hole  542  which will be described later, is arranged at the protruded tip of the movable pin  531 . 
     The link arm  54  is the member that moves the engagement member  51  in accordance with the movement of the solenoid  53 . The link arm  54  is the planar member that bends at the center, and the supported hole  541 , through which the supporting shaft  502  passes, is formed at the center. In addition, a long-hole-shaped solenoid connection hole  542 , through which the link pin  532  of the solenoid  53  passes, is formed at one end of the link arm  54 . A long-hole-shaped engagement portion connection hole  543 , through which the supporting shaft  513  of the engagement member  51  passes, is formed at another end of the link arm  54 . 
     The link arm  54  is supported at the supported hole  541  such that the link arm  54  can rotate around the supporting shaft  502 , thus one end moves in the direction opposite to the direction of the movement of another end across the supported hole  541 . In addition, as shown in  FIG. 2 , a damper  55  is attached to the link arm  54  to reduce the speed of the link arm  54 . The damper  55  may be omitted. 
     As shown in  FIG. 2 , in the rotation inhibiting unit  5 , the engagement member  51  and the solenoid  53  are arranged in parallel. The direction of the movement of the engagement member  51  is parallel to the direction of the movement of the movable pin  531  of the solenoid  53 , and the movable pin  531  is connected with the link arm  54  such that the link pin  532  of the movable pin  531  passes through the solenoid connection hole  542  of the link arm  54 . In addition, the engagement member  51  is connected with the link arm  54  such that the supporting shaft  513  of the engagement member  51  passes through the engagement portion connection hole  543  of the link arm  54 . 
       FIG. 8  is a cross sectional view of a part of the driving device for opening and closing in which the engagement member is not engaged with the engaged member.  FIG. 9  is a cross sectional view of a part of the driving device for opening and closing in which the engagement member is engaged with the engaged member.  FIG. 10  is a cross sectional view of the rotation inhibiting unit illustrated in  FIG. 8  cut with an X-X line.  FIG. 11  is a cross sectional view of the rotation inhibiting unit illustrated in  FIG. 9  cut with an XI-XI line. 
     As shown in  FIG. 8 , an emergency lever  551  protrudes and elongates outwardly from the vicinity of the central part of the link arm  54 . The emergency lever  551  has a base portion  551   a , a weight  551   b , a lever body portion  551   c , and a manipulation portion  551   d . The base portion  551   a  is attached to the vicinity of the central part of the link arm  54 . The lever body portion  551   c  is the planar member that elongates from the base portion  551   a . The weight  551   b  adds weight to a part of the lever body portion  551   c  and can be formed, for example, by increasing the thickness of the part of the lever body portion  551   c . The weight  551   b  is arranged in the vicinity of the end portion of the lever body portion  551   c . The manipulation portion  551   d  is the portion that is manipulated manually when the emergency lever  551  is moved. 
     The emergency lever  551  is formed integrally with the link arm  54  and can rotate the link arm  54  on the supporting shaft  502  by manipulating manually the manipulation portion  551   d . Therefore, as shown in  FIG. 8 , the rotation of the rod member  2  can be stopped by pushing the manipulation portion  551   d  downwardly such that the engagement member  51  engages with the engaged member  52  when the engagement member  51  and the engaged member  52  are not engaged with each other due to the movement of the solenoid  53 . 
     The weight  551   b  is formed such that the weight is applied in the direction opposite to the direction of the movement of the link arm  54  due to the movement of the solenoid  53 . As shown in  FIG. 8 , if the link arm  54  rotates anti-clockwise due to the movement of the solenoid  53 , the weight of the weight  551   b  is applied in the directed such that the weight rotates the link arm  54  clockwise. 
     The weight  551   b  is one example of the mechanical structure that inhibits the vibrations of the link arm  54  and the engagement member  51  by applying a force to the link arm  54  (link member) in the direction different from the direction of the movement of the link arm  54  to change the movement when the engagement member  51  vibrates. In addition, in the present embodiment, the weight  551   b  specifically plays a role of the movement inhibiting portion that applies the force to the link arm  54  in the direction different from the direction of the movement of the link arm due to the movement of the solenoid  53 . 
     The operation of the rotation inhibiting unit  5  formed as above will be described below. 
     If the movable pin  531  of the solenoid  53  moves in the retracting direction, the solenoid connection hole  542  of the link arm  54  is pulled by the link pin  532 . At this timing, as shown in  FIG. 8 , the link arm  54  rotates in L 1  direction around the supporting shaft  502  and the engagement portion connection hole  543  pulls the supporting shaft  513 . Thus, the engagement member  51  moves to the engagement release position P 1  (see  FIG. 8  and  FIG. 10 ) where the engagement member  51  is away from the rod member  2 , namely, the engagement with the engaged member  52  is released and the rod member  2  can rotate. It should be noted that, as described above, since the solenoid  53  is a self-holding type solenoid, the engagement member  51  is maintained at the engagement release position P 1  even if the supply of electric power to the solenoid  53  is stopped. 
     As described above, the link arm  54  is connected to the movable pin  531  of the solenoid  53  via the link pin  532 . The emergency lever  551  is formed integrally with the link arm  54 . Moreover, the weight  551   b , which is configured to apply the weight in the direction different from the direction of the movement of the link arm  54  due to the movement of the solenoid  53 , is provided in the emergency lever  551 . 
     Because of the above, the impulsive noise, which is generated when the movable pin  531  abuts the fixed iron core inside the solenoid  53  when the movable pin  531  of the solenoid  53  moves in the retracting direction, is reduced or the tone range of the impulsive noise is changed. 
     On the other hand, when the movable pin  531  of the solenoid  53  moves in the protruding direction, the solenoid connection hole  542  of the link arm  54  is pushed by the link pin  532 . At this timing, as shown in  FIG. 9 , the link arm  54  rotates in R 1  direction in the Figure on the supporting shaft  502  and the engagement portion connection hole  543  pushes the supporting shaft  513 . Thus, the engagement member  51  approaches the rod member  2  and moves to the engagement position P 2  (see  FIG. 9  and  FIG. 11 ) where the engagement member  51  engages with the engaged member  52 . It should be noted that, as described above, since the solenoid  53  is a self-holding type solenoid, the engagement member  51  is maintained at the engagement position P 2  even if the supply of electric power to the solenoid  53  is stopped. As such, the solenoid can move between the engagement release position P 1  and the engagement position P 2  by the solenoid  53 . 
     Next, the operation of the driving device for opening and closing A will be described, referring to the figures. In the driving device for opening and closing A, the rotation power outputted from the motor M is transmitted to the rod member  2  via the clutch  1 . When the clutch  1  and the motor M are energized, the rotation power generated by driving the motor M is transmitted to the rod member  2 . 
     When the engagement member  51  of the rotation inhibiting unit  5  is positioned at the engagement release position P 1  (see  FIG. 8  and  FIG. 10 ), the rotation inhibiting unit  5  is in the state where the rotation inhibiting unit  5  does not inhibit the rotation of the rod member  2  because the engagement member  51  and the engaged member  52  are in the state where they are separated from each other. In this state, the rod member  2  is rotated by the rotation power of the motor M. By rotating the rod member  2 , the nut member  3 , which has the female-threaded portion  31  that is screwed with the screw portion  23  of the rod member  2 , moves along the guide rail  20 . 
     As shown in  FIG. 1 , since the driving device for opening and closing A, the connection member  4 , and the opening/closing body Dr form the link mechanism, the opening/closing body Dr moves around the supporting point Fc in the opening direction or the closing direction. It should be noted that the direction of the movement of the nut member  3  is determined by the rotation direction of the rod member  2 . Namely, the direction of the movement (the opening direction or the closing direction) of the opening/closing body Dr is determined by the rotation direction of the rod member  2 . As such, the opening/closing body Dr can open or close by switching the rotation direction of the motor M. 
     Since the opening/closing body Dr, which is arranged at the back opening of the vehicle Cr, opens while rotating backwardly, a large space is required in the back part of the vehicle Cr in the opening/closing operation. When the opening/closing body Dr is opened at the place where there is no enough space, the user wants to open the opening/closing body Dr to make the opening smaller due to rain and/or wind, or the opening/closing body Dr is about to touch a person, a wall, or etc., it is required to stop the opening/closing body Dr at the intermediate position of full opening or closing and maintain the position of the opening/closing body Dr. In other words, this type of opening/closing body Dr is required to stop at arbitral positions between the full-open position and the full-close position and maintain its position. 
     In order to maintain the opening/closing body Dr at arbitral positions in the middle of opening and closing, in the driving device for opening and closing A of the present invention, the method to inhibit the rotation of the rod member  2  using the rotation inhibiting unit  5  is used. The method to inhibit the rotation of the rod member  2  will be described below. 
     The solenoid  53  of the rotation inhibiting unit  5  is operated to protrude the movable pin  531 . Thus, the engagement member  51  moves via the link arm  54  from the engagement release position P 1  to the engagement position P 2 . At this timing, the engagement portion  511  of the engagement member  51  engages with the engagement concave portion  523  of the engaged member  52 . Thus, the movement of the engaged member  52  is inhibited by the engagement member  51  and the rotation of the rod member  2 , which is key-connected with the engaged member  52 , is also inhibited. Thus, the movement of the nut member  3  is stopped and the opening/closing body Dr is stopped. It should be noted that, as described above, since the solenoid  53  is a self-holding type solenoid, the solenoid  53  is maintained in the state where the movable pin  531  is protruded. Thus, the engagement member  51  is also maintained at the engagement position P 2  (see  FIG. 9  and  FIG. 11 ) where the engagement portion  511  engages with the engagement concave portion  523 . 
     When the movable pin  531  of the solenoid  53  protrudes, it is possible that an impulsive noise is generated when the engagement portion  511  of the engagement member  51  abuts the engagement concave portion  523  of the engaged member  52 . Also in this case, since the vibration is transmitted to the weight  551   b  arranged in the emergency lever  551  via the link arm  54  and the engagement member  51 , the impulsive noise can be reduced, or the tone range of the impulsive noise can be changed. Therefore, the impulsive noise transmitted to the user can be reduced, thereby preventing the user from feeling uncomfortable. 
     It should be noted that, when the engagement member  51  moves from the engagement release position P 1  to the engagement position P 2 , there is the case where, during the rotation of the rod member  2 , the engagement portion  511  touches the part of the outer periphery of the engaged member  52  on which no engagement concave portion  523  is formed. In this case, since the engagement portion  511  is inserted into the adjacent engagement concave portion  523  by the rotation of the rod member  2 , the engagement member  51  is engaged with the engaged member  52  and the rotation of the rod member  2  is inhibited. 
     In addition, since the direction of the movement of the engagement member  51  is perpendicular to the axis of the rod member  2 , and the force, which is applied to the engagement portion  511  from the side wall of the engagement concave portion  523  when the engagement portion  511  of the engagement member  51  engages with the engagement concave portion  523  of the engaged member  52 , crosses the direction of the movement of the engagement member  51 . On the other hand, the opening/closing body Dr pushes the connection member  4  downward (in the closing direction) by its gravitational force. The nut member  3 , which is pushed by the connection member  4 , generates the rotation force in the rod member  2 . The side wall of the engagement concave portion  523  pushes the engagement portion  511  by this rotation force. The pushing force of the side wall of the engagement concave portion  523  applied to the engagement portion  511  hardly pushes back the engagement member  51 , and even if the above-described force is applied to the engagement portion  511 , the holding force of the solenoid  53  can maintain the engagement member  51  at the engagement position P 2 . 
     With the driving device for opening and closing A according to the present invention, since the engagement member  51  engages mechanically with the engaged member  52 , the opening/closing body Dr can be stopped securely at arbitral positions. 
     In this case, the link arm  54  (one example of the link arm), which moves the engagement member  51  in accordance with the movement of the solenoid  53  (one example of the solenoid), is arranged, and by changing the vibration condition of the engagement member  51  to inhibit the vibration, the noise generated due to the movement of the solenoid  53  is reduced, or the tone range of the noise is changed, thus the uncomfortable feeling of the user can be reduced. 
     It should be noted that the mechanical structure that inhibits the vibration by changing the vibration condition of the engagement member in the link member is not limited to the form of the emergency lever  551  of the above-described embodiment. 
     In addition, although, in the present embodiment, the above-described mechanical structure is the movement inhibiting portion that applies the force to the link arm  54  in the direction different from the direction of the movement of the link arm  54  due to the movement of the solenoid, the mechanical structure may have other mechanisms to change the vibration condition of the engagement member  51  in the link arm  54 . The structure that can change the vibration condition of the engagement member with the stably-working mechanical structure can be used, such as, for example, the structure generating the moment in the direction different from the engagement direction of the engagement member due to the weight of the thicker part of the link arm, the structure generating the moment in the direction different from the engagement direction of the engagement member due to the changes of the shape and material, and etc. 
     Moreover, in the present embodiment, the movement inhibiting portion is the weight  551   b  that is arranged in the vicinity of the end portion of the emergency lever  551  attached to the link arm  54  and elongating, the existence or non-existence of the elongating member, and the position and shape of the weight is not limited to the above-described embodiment. 
     By changing the weight and/or shape of the weight in accordance with the size and/or material of the solenoid  53 , the engagement member  51 , the link arm  54 , the emergency lever  551 , and etc., the reduction of the impulsive noise and/or the change of the tone range can be adjusted arbitrarily. 
     Thus, it is inhibited that the user feels uncomfortable by the impulsive noise during the movement of the solenoid  53 . 
     The consumption of electric power can be reduced since it is not required to supply electric power to the solenoid  53  after the engagement member  51  is engaged with the engaged member  52 . In addition, in the driving device for opening and closing A of the present invention, since the opening/closing body Dr is maintained at arbitral positions by the mechanical engagement of the engagement member  51  with the engaged member  52 , the supply of electricity to the clutch  1  can be stopped. Thus, compared to the conventional device in which the rod member  2  is maintained by the clutch, the wear of the clutch can be reduced and the durability of the clutch can be increased. 
     In addition, the rod member and the nut member may have a ball screw structure. By using a ball screw structure, the friction between the screw and the female threads during the movement of the nut member can be reduced and the wear of the rod member and/or the nut member can be reduced. In addition, by reducing the friction, the output of the motor can be reduced and the consumption of electric power can be reduced. 
     The present invention is not limited to the above-described invention and any modifications can be made within the scope of the invention. 
     The present invention can be used as the opening/closing apparatus that opens and closes the flip-up type opening/closing body such as a rear door, a trunk lid, or etc. by electric power.

Summary:
A driving device for opening and closing an opening/closing body of a vehicle. The driving device comprises a nut member that moves linearly by way of rotation of a rod member and is threadably engaged with the rod member, and an engaging member that can be engaged with an engagement-receiving member provided on the rod member that is moved by way of a link arm linked to actuation of a solenoid such that rotation of the rod member can be stopped. The link arm has a mechanical structure that limits vibrations that change the vibration status of the engaging member. By using this driving device, impact noise during actuation of the driving device can be mitigated, or the pitch of the noise can be altered, so as not to discomfort passengers.