Patent Publication Number: US-2021162607-A1

Title: Electric gripping device

Description:
TECHNICAL FIELD 
     The present invention relates to an electric gripping device. 
     BACKGROUND ART 
     A gripper may be used when picking up and transferring objects using automation equipment. When using the gripper, a pneumatic gripper with a simple structure and simple control can be used. Since the pneumatic gripper needs to have a separate pneumatic facility, the electric gripper may be used in cases of standalone equipment or a robot. Among the electric grippers, two-fingered grippers are widely used. Some electric grippers have fingers that perform a straight line movement like the pneumatic grippers, but most of them may use four-joint links on the fingers to increase the gripping distance. 
     The two-fingered electric gripper that uses four-joint links on the fingers takes up a lot of space as the length of the gripper increases when two fingers are moved simultaneously using one motor. Therefore, the two-fingered electric gripper using a joint link may act as a limitation in securing a work space and a work direction when being connected to a robot or the like. 
     As related prior art, Korean Patent No. 1,674,894 discloses “Multi-degrees of freedom gripper for industry”, Korean Patent No. 1,701,236 discloses “Actuator module”, and Japanese Patent No. 5,892,173 discloses “Robot hand and robot”. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     DISCLOSURE 
     Technical Problem 
     An embodiment of the present invention to provide an electric gripping device that easily realizes assembly and disassembly of an actuator module and a clamper module by improving a coupling relationship between a two-fingered clamper module using a four-joint link and an actuator module and easily secures a robot&#39;s work space or a work direction when being connected to the robot by minimizing a length of an electric gripper. 
     Technical Solution 
     An electric gripping device according to a first actuator module having a first fixing unit and generating a torque of a first drive shaft; a second actuator module having a second fixing unit and generating a torque of a second drive shaft; a main body unit having a first coupling unit in which the first actuator module is coupled at a position corresponding to the first fixing unit and the second actuator module is coupled at a position corresponding to the second fixing unit and a second coupling unit outside of which a part of a gripper is coupled; a first finger link unit having one end that is connected to each of the first actuator module and the main body to be link-connected and transmitting power corresponding to the first clamper of the other end; and a second finger link unit having one end that is connected to each of the second actuator module and the main body unit to be link-connected and transmitting power corresponding to a second clamper of the other end, wherein the first finger link unit and the second finger link unit are formed of a four-joint link, respectively, the first clamper and the second clamper are separated from each other to be provided at a position facing each other along the length direction of the main body unit, and the first clamper and the second clamper approach or are separated from each other. 
     The first finger link unit may include: an eleventh link rotating with a first connection point coupled to both sides of the length direction of the first drive shaft; a twelfth link rotating with a second connection point coupled to the main body unit; a thirteenth link rotating with a third connection point coupled to the eleventh link; and a fourteenth link having a fourth connection point coupled with the thirteenth link at one end, a fifth connection point coupled with the twelfth link at a bent part, and a fourteenth link with a first clamper at the other end. A straight line length a 1  between the first connection point and the second connection point may be the same as a straight line length a 2  between the fourth connection point and the fifth connection point. A straight line length b 1  between the first connection point and the fourth connection point may be the same as a straight line length b 2  between the second connection point and the fifth connection point. 
     The eleventh link may include: an eleventh connection part having one end respectively coupled to both sides of a length direction of the first drive shaft and the other end disposed to be inclined with a predetermined angle upward; and a twelfth connection part including an eleventh coupling rod formed in a length direction and coupled between the other ends of the eleventh connection part and a twelfth coupling rod formed to be elongated with a predetermined angle at the center of the length direction of the eleventh coupling rod to be coupled with one end of the twelfth link, wherein the eleventh connection part and the twelfth connection part may be coupled to be inclined with a predetermined angle in consideration of driving interference with the first actuator module. 
     The second finger link unit may include: a twenty-first link rotating with a first connection point coupled to both sides of the length direction of the second drive shaft; a twenty-second link rotating with a second connection point coupled to the main body unit; a twenty-third link rotating with a third connection point coupled to the twenty-first link; and a twenty-fourth link having a fourth connection point coupled with the twenty-third link at one end, a fifth connection point coupled with the twenty-second link at the bent part, and a second clamper at the other end. 
     The twenty-first link may include: a twenty-first connection part having one end respectively coupled to both sides of the length direction of the second drive shaft and the other end disposed to be inclined upward with a predetermined angle; and a twenty-second connection part having a twenty-first coupling rod formed in the length direction and coupled between the other ends of the twenty-first connection part and a twenty-second coupling rod elongated with a predetermined angle at the center part of the length direction of the twenty-first coupling rod and coupled with one end of the twenty-second link, wherein the twenty-first connection part and the twenty-second connection part may be combined obliquely at a predetermined angle in consideration of driving interference with the second actuator module. 
     The main body unit may include: a first body unit provided at one side via the first actuator module and the second actuator module and coupled with the first actuator module and the second actuator module; and a second body unit provided at the other side corresponding to the first body unit via the first actuator module and the second actuator module and coupled with the first actuator module and the second actuator module. 
     The first body unit may include: an eleventh body member formed of a cuboid panel shape; and a twelfth body member formed on the eleventh body member and having the second coupling unit, wherein an eleventh coupling unit may be formed at a position respectively corresponding to the first fixing unit and the second fixing unit at the lower surface of the eleventh body member. 
     The second body unit may include: a twenty-first body member formed at the position corresponding to the eleventh body member via the first actuator module and the second actuator module; and a twenty-second body member formed under the twenty-first body member and having a hand coupling unit, and a twenty-first coupling unit may be formed at the position respectively corresponding to the first fixing unit and the second fixing unit at the upper surface of the twenty-first body member. 
     The first fixing unit and the second fixing unit may be formed at the first actuator module and the second actuator module, respectively, and the first fixing unit may include a fastening hole provided at a concave groove formed at the edge of the first actuator module. 
     On the other hand, in an electric gripping device according to another embodiment of the present invention, the first fixing unit and the second fixing unit may be formed at the first actuator module and the second actuator module, and the first fixing unit may include a plurality of fastening holes provided at a protrusion formed along the circumferential surface on both sides of the first actuator module. 
     Advantageous Effects 
     An embodiment of the present invention improves the coupling relationship between the driving link of the gripper and the actuator module so as to not have interference between the driving link of the electric gripper and the actuator module, so that the assembly and disassembly of the actuator module and the driving link of the gripper nay be easily implemented, and when being connected to a robot, it is possible to easily secure the robot&#39;s work space or work direction. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view showing a coupling state of an electric gripping device according to an embodiment of the present invention. 
         FIG. 2  is an exploded perspective view showing a coupling relation of an electric gripping device according to an embodiment of the present invention. 
         FIG. 3  is an exploded perspective view showing a coupling relation of a main body unit and an actuator module according to an embodiment of the present invention. 
         FIG. 4  is a perspective view showing a coupling state of an electric gripping device according to another embodiment of the present invention. 
         FIG. 5  is a partially exploded perspective view showing a coupling relation of an electric gripping device according to another embodiment of the present invention. 
     
    
    
     MODE FOR INVENTION 
     The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, without departing from the spirit or scope of the present invention. In order to clearly explain the present invention, portions that are not directly related to the present invention are omitted, and the same reference numerals are attached to the same or similar constituent elements through the entire specification. In addition, in cases of well-known technologies, detailed descriptions thereof will be omitted. 
     Throughout the specification, unless explicitly described to the contrary, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. 
     Now, an electric gripping device according to an embodiment of the present invention is described. 
       FIG. 1  is a front view showing a coupling state of an electric gripping device according to an embodiment of the present invention,  FIG. 2  is an exploded perspective view showing a coupling relation of an electric gripping device according to an embodiment of the present invention, and  FIG. 3  is an exploded perspective view showing a coupling relation of a main body unit and an actuator module according to an embodiment of the present invention. Referring to  FIG. 1  to  FIG. 3 , an electric gripping device according to an embodiment of the present invention includes a first actuator module  100 , a second actuator module  200 , a main body unit  300 , a first finger link unit  400 , and a second finger link unit  500 , wherein the first finger link unit  400  and the second finger link unit  500  are formed of the same four-joint link as each other, are separated from each other among a length direction of the main body unit  300 , and are provided at positions where the first clamper and the second clamper face each other, thereby mutually approaching and separating from each other. The electric gripping device may be implemented with a two-fingered four-joint link electric gripper. 
     The first actuator module  100  has a first fixing unit  110 , and may function as a first driver that generates a torque of a first drive shaft  102 . The second actuator module  200  has a second fixing unit  210 , disposed at a position corresponding to the first actuator module  100 , and may function as a second driver that generates a torque of a second drive shaft  202 . The first fixing unit  110  and the second fixing unit  210  may be combined with the main body unit  300  in a fastening structure. Thus, the first actuator module  100  and the second actuator module  200  may be easily coupled to or separated from the main body unit  300 . 
     The main body unit  300  has a first coupling unit in which the first actuator module  100  and the second actuator module  200  are respectively coupled at positions respectively corresponding to the first fixing unit  110  and the second fixing unit  210 , and a second coupling unit that is formed in a separate coupling structure and to which a part of the gripper is coupled on the outside. The main body unit  300  may include a first body unit  310  and a second body unit  320 . The first body unit  310  is provided on one side via the first actuator module  100  and the second actuator module  200 , and may be combined with the first actuator module  100  and the second actuator module  200 . The first body unit  310  may include an eleventh body member  312  formed with a cuboid panel shape, and a twelfth body member  314  formed on the eleventh body member  312  and having a second coupling unit. An eleventh coupling unit  316  may be formed at positions respectively corresponding to the first fixing unit  110  and the second fixing unit  210  at the lower surface of the eleventh body member  312 . Here, the first fixing unit  110  and the second fixing unit  210  may have the same shape as each other, and may be formed in the first actuator module  100  and the second actuator module  200 . The first fixing unit  110  may include a fastening hole  114  provided on a concave groove  112  formed on the corner part of the first actuator module  100 . 
     The second body unit  320  may be provided on the other side corresponding to the first body unit  310  via the first actuator module  100  and the second actuator module  200 , and may be coupled with the first actuator module  100  and the second actuator module  200 . The second body unit  320  may include a twenty-first body member  322  formed with a cuboid panel shape at a position corresponding to the eleventh body member  312  via the first actuator module  100  and the second actuator module  200 , and a twenty-second body member  324  formed under the twenty-first body member  322  and having a hand coupling unit. A twenty-first coupling unit  326  may be formed at a position respectively corresponding to the first fixing unit  110  and the second fixing unit  210  on the upper surface of the twenty-first body member  322 . Since one surface of the second body unit  320  may be fastened to the hand of the robot by using the twenty-second body member  324  having the hand coupling unit, it is easy to attach and detach the electric gripper to and from the hand of the robot. In addition, the fastening structure of the first actuator module  100  and the second actuator module  200  may be connected to the electric gripper by using only one side, so it is easy for it to be disassembled and assembled. 
     The first finger link unit  400  and the second finger link unit  500  may be formed of the same four-joint link as each other, and may be separated from each other along the length direction of the main body unit  300  and provided at the position where the first clamper and the second clamper face to each other, thereby mutually approaching and separating from each other. The first finger link unit  400  and the second finger link unit  500  have a pair of clampers that are spaced apart so as to mutually approach each other to hold objects, and these clampers may perform a gripping operation with a parallel link mechanism. Since the first finger link unit  400  and the second finger link unit  500  do not have a separate driver under the link, the entire length of the electric gripper may be minimized. Therefore, when being combined to the hand of the robot, the working radius in the working space may be reduced and it is possible to easily select and secure a work direction. 
     The first finger link unit  400  is respectively coupled to the first actuator module  100  and the main body unit  300  with one end, thereby transmitting corresponding power to the link-connected first clamper. The first finger link unit  400  may include an eleventh link  410 , a twelfth link  420 , a thirteenth link  430 , and a fourteenth link  440 . 
     The eleventh link  410  functions as a driving link, and may be formed with a predetermined angle in advance in consideration of interference with the first actuator module  100 . The eleventh link  410  may be formed to be bent at an appropriate angle and be rotated with a first connection point  410   a  coupled to both sides in the length direction of the first drive shaft  102 . The eleventh link  410  may include an eleventh connection part  412  and a twelfth connection part  414 . The eleventh connection part  412  and the twelfth connection part  414  may be formed to be inclined at a predetermined angle in advance in consideration of the driving interference with the first actuator module  100 . The eleventh connection part  412  may have one end coupled to both sides in the length direction of the first drive shaft  102 , and the other end may be disposed to be inclined upward with a predetermined angle in advance. The eleventh connection part  412  may have one side formed wide and the other side formed narrow along a length direction. At a position where the eleventh connection part  412  is coupled to the first drive shaft  102 , a coupling plate  102   a  may be provided around the first drive shaft  102 . The coupling plate  102   a  has a plurality of fastening holes in a circumferential direction. In addition, the eleventh connection part  412  may have a coupling hole having a round shape corresponding to the shape of the coupling plate  102   a  and disposed corresponding to the fastening hole at a position corresponding to the coupling plate  102   a . As the eleventh connection part  412  and the coupling plate  102   a  are coupled with the fastening structure at a plurality of positions, the driving force of the first actuator module  100  may be transmitted to the electric gripper more sturdily and stably. 
     The twelfth connection part  414  may include an eleventh coupling rod formed in the length direction and coupled between the other ends of the eleventh connection parts  412 , and a twelfth coupling rod elongated with a predetermined angle in advance at the center part in the length direction of the eleventh coupling rod and coupled to one end of the thirteenth link  430 . 
     The twelfth link  420  may be rotated with a second connection point  420   a  coupled to the main body unit  300 . The thirteenth link  430  may be rotated with a third connection point  430   a  coupled to the eleventh link  410 . The thirteenth link  430  may be implemented as one link so that it may be fixedly connected to the eleventh link  410  to be moved together. In this case, the thirteenth link  430  may be implemented with two third connection points  430   a  coupled to the eleventh link  410 . 
     The fourteenth link  440  has a fourth connection point  440   a  coupled with the thirteenth link  430  at one end and a fifth connection point coupled with the twelfth link  420  at the bent part, and the other end has a first clamper. Here, the straight line length a 1  between the first connection point  410   a  and the second connection point  420   a  may be the same as the straight line length a 2  between the fourth connection point  440   a  and a fifth connection point  440   b . In addition, the straight line length b 1  between the first connection point  410   a  and the fourth connection point  440   a  may be the same as the straight line length b 2  between the second connection point  420   a  and the fifth connection point  440   b . Accordingly, the first finger link unit  400  and the second finger link unit  500  are formed of the same four-joint link as each other, and are disposed to be separated at positions facing each other along the length direction of the main body unit  300  and equally form the connection position between the links, thereby mutually approaching and separating from each other to be parallel to each other. Also, the first finger link unit  400  and the second finger link unit  500  may be easily detached from and attached to the main body unit  300 , the first actuator module  100 , and the second actuator module  200  while keeping them parallel. Therefore, it is possible to minimize the length of the electric gripper and secure the work space of the robot or the work direction when being connected to the robot. 
     One end of the second finger link unit  500  may be respectively coupled to the second actuator module  200  and the main body unit  300  to transmit the corresponding power to the link-connected second clamper of the other end. The second finger link unit  500  may include a twenty-first link  510 , a twenty-second link  520 , a twenty-third link  530 , and a twenty-fourth link  540 . 
     The twenty-first link  510  may be rotated with the first connection point  410   a  that is coupled to both sides in the length direction of the second drive shaft  202 . The twenty-first link  510  may include a twenty-first connection part  512  and a twenty-second connection part  514 , and the twenty-first connection part  512  and the twenty-second connection part  514  may be coupled with a predetermined angle in advance in consideration of driving interference with the second actuator module  200 . In the twenty-first connection part  512 , one end is coupled to both sides in the length direction of the second drive shaft  202 , and the other end may be disposed to be inclined upward with a predetermined angle in advance. The twenty-second connection part  514  may include a twenty-first coupling rod formed in the length direction and coupled between the other ends of the twenty-first connection part  512 , and a twenty-second coupling rod formed to be elongated with a predetermined angle at the center of the length direction of the twenty-first coupling rod and coupled to one end of the twenty-third link  530 . 
     The twenty-second link  520  may be rotated with the second connection point  420   a  coupled to the main body unit  300 . The twenty-third link  530  may be rotated with the third connection point  430   a  coupled to the twenty-first link  510 . The twenty-third link  530  may be implemented as one link to be fixedly connected to the twenty-first link  510  and to move together. In this case, the twenty-third link  530  may be implemented with two third connection points  430   a  coupled to the twenty-first link  510 . 
     The twenty-fourth link  540  has the fourth connection point  440   a  at one end that is coupled with the twenty-third link  530 , the fifth connection point  440   b  that is coupled with the twenty-second link  520  at the bent part, and a second clamper at the other end. 
     As above-described, the electric gripping device according to an embodiment of the present invention may include the electric gripper of a two-fingered four-joint link shape that may realize the minimum length by being provided parallel between the main body unit  300  and the actuator module. In other words, by implementing the two-fingered four-joint link electric grippers in parallel when combining the actuator module and the gripper link module, when the electric gripper is combined with the robot&#39;s hand, the entire length of the electric gripper may be shortened to facilitate securing the work space or the work direction. 
     The electric gripping device may easily assemble and disassemble the actuator module and the clamper module by improving the coupling relationship between the two-fingered clamper module using the four-joint link and the actuator module. Also, the driving force of the first actuator module  100  and the second actuator module  200  may be transmitted directly to the first finger link unit  400  and the second finger link unit  500 . In addition, by improving the coupling relationship between the clamper module and the actuator module so that the driving link of the clamper module does not interfere with the actuator module when the clamper module and actuator module are combined, when being connected to the robot, it is possible to easily secure the robot&#39;s work space or the work direction 
     An operation of the electric gripping device according to an embodiment of the present invention is now described with reference to  FIG. 1  to  FIG. 3 . 
     First, in the state that the first actuator module  100  and the second actuator module  200  are coupled to the main body unit  300 , the first drive shaft  102  and the second drive shaft  202  may be respectively rotated by the driving of the first actuator module  100  and the second actuator module  200 . When assuming that the first drive shaft  102  rotates in the clockwise direction by the driving of the first actuator module  100 , the power of the first drive shaft  102  may be transferred to the eleventh link  410 . Accordingly, the eleventh link  410  may be rotated in the same direction as the first drive shaft  102 . If the first drive shaft  102  is rotated in the clockwise direction, the eleventh link  410  of the first finger link unit  400  may be interlocked and be rotated in the clockwise direction. Also, the thirteenth link  430  connected to the eleventh link  410  may move upward. The fourteenth link  440  may also be connected to the thirteenth link  430 , so it may move upward. In this case, since the fourteenth link  440  is respectively connected to the twelfth link  420  and the thirteenth link  430 , the fourteenth link  440  may move in the direction of the second finger link unit  500 . 
     Meanwhile, the second drive shaft  202  may be rotated in a counterclockwise direction by the driving of the second actuator module  200  so that the second finger link unit  500  may be closed or unfolded together with the first finger link unit  400 . When the second drive shaft  202  rotates in the counterclockwise direction, the twenty-first link  510  of the second finger link unit  500  is interlocked and may be rotated in the counterclockwise direction. Also, the twenty-third link  530  connected to the twenty-first link  510  may move upward. The twenty-fourth link  540  is also connected to the twenty-third link  530 , so it may move upward. In this case, since the twenty-fourth link  540  is respectively connected to the twenty-second link  520  and the twenty-third link  530 , the twenty-fourth link  540  may move in the direction of the first finger link unit  400 . 
     As the eleventh link  410  and the twenty-first link  510  that are horizontally disposed based on the first drive shaft  102  of the first actuator module  100  and the second drive shaft  202  of the second actuator module  200  are rotated respectively in the clockwise direction and the counterclockwise direction, the first finger link unit  400  and the second finger link unit  500  may be close to each other. On the contrary, when the rotation direction of the first drive shaft  102  and the second drive shaft  202  is changed, the first finger link unit  400  and the second finger link unit  500  can be separated from each other. 
     As described above, if the electric gripping device according to an embodiment of the present invention is used, the coupling relationship between the clamper module and the actuator module is improved so that the driving link of the electric gripper does not interfere with the actuator module, thereby it is possible to easily assemble and disassemble the actuator module and the clamper module. And since the length of the electric gripper is minimized, it is easy to secure the work space or the work direction when the electric gripper is attached to the hand of the robot, so the use of the electric gripper may be greatly expanded. 
       FIG. 4  is a perspective view showing a coupling state of an electric gripping device according to another embodiment of the present invention, and  FIG. 5  is a partially exploded perspective view showing a coupling relation of an electric gripping device according to another embodiment of the present invention. Referring to  FIG. 4  and  FIG. 5 , the electric gripping device according to another embodiment of the present invention is different in the method that a first actuator module  100   a  and a second actuator module  200   a  are coupled to the main body unit  300   a , and may be equally applied to the electric gripping device according to an embodiment of the present invention in configuration and operation other than the coupling method. 
     Referring to  FIG. 4  and  FIG. 5 , the main body unit  300   a  may include a first body unit  310   a  provided on one side via the first actuator module  100   a  and the second actuator module  200   a  and coupled with the first actuator module  100   a  and the second actuator module  200   a , and a second body unit  320   a  provided on the other side corresponding to the first body unit  310   a  via the first actuator module  100   a  and the second actuator module  200   a  and coupled with the first actuator module  100   a  and the second actuator module  200   a.    
     The first body unit  310   a  may include an eleventh body member  312   a  formed of a cuboid panel shape and a twelfth body member  314   a  formed on the eleventh body member  312   a  and having a second coupling unit. An eleventh coupling unit  316   a  may be formed at the positions respectively corresponding to the first fixing unit and the second fixing unit at the lower surface of the eleventh body member  312   a . Here, the first fixing unit and the second fixing unit may be formed on the first actuator module  100   a  and the second actuator module  200   a  with the same shape as each other. The first fixing unit may include a plurality of fastening holes  100   a   2  provided in a protrusion portion  100   a   1  formed along both circumferential surfaces of the first actuator module  100   a.    
     The second body unit  320   a  may include a twenty-first body member  322   a  formed with a cuboid panel shape at a position corresponding to the eleventh body member  312   a  via the first actuator module  100   a  and the second actuator module  200   a , and a twenty-second body member  324   a  formed under the twenty-first body member  322   a  and having a hand coupling unit. A twenty-first coupling unit  326   a  may be formed at a position respectively corresponding to the first fixing unit and the second fixing unit on the upper surface of the twenty-first body member  322   a.    
     While this invention has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.