Rotary electric gripper for robot mounting

Abstract

Disclosed is a rotary electric gripper for robot mounting. The rotary electric gripper for robot mounting may comprise: a driving unit which is provided with a worm gear on a rotary shaft and provides a driving force; a pair of links arranged on opposite sides of the worm gear, wherein a gear groove in the shape of a worm wheel is formed on a portion of the outer circumferential surface of a rotary shaft portion to rotate in engagement with the worm gear, and fingers for gripping an object to be gripped are provided at the end; and a housing in which the driving unit is installed on one side and the pair of links are axially coupled to the other side.

Description

Rotary electric gripper for robot mounting

[0001] The present invention relates to a rotary electric gripper for robot mounting, and more specifically, to a rotary electric gripper for robot mounting, which eliminates the space between links to prevent a pinching accident, and forms a worm wheel-shaped gear groove on one side of a rotational axis portion of a link to directly mesh with a worm gear of a driving unit without a separate medium to perform a rotational motion, thereby minimizing component parts and reducing volume and weight.

[0002] The use of robots to handle materials, processed goods, and finished products is becoming widespread across virtually all industries, including semiconductor manufacturing facilities, automotive parts assembly processes, and machine tools. Furthermore, advancements in vision technology are expanding the application of industrial robots to even more precise tasks.

[0003] Typically, in automated factories or processes for assembling precision parts or assembling and manufacturing vehicle parts, there is a gripper mounted on a robot as an end effector to grip parts as they are transported, assembled, or manufactured.

[0004] Meanwhile, a 'gripper (Korean Patent No. 10-2269012)' with three degrees of freedom has been proposed.

[0005] These conventional grippers receive driving force from a driving unit so that multiple links rotate to allow the fingers to grip the object to be gripped.

[0006] However, conventional grippers have a structural problem in that multiple links rotate at set intervals, creating a space between the links, which can cause a crushing accident for workers or surrounding objects.

[0007] In addition, the link that rotates by the driving unit is configured to be rotatable by a worm gear method. In this case, since it basically includes a worm gear that is axially coupled to the driving unit, a worm wheel that rotates while meshing with the worm gear, and a link that is axially coupled to the worm wheel, there is a problem that the structure is complicated and the volume and weight increase.

[0008] In addition, there is a problem that the driving force provided from the driving rotor may be lost during the process of transmitting the driving force to the finger that grips the object to be gripped, and vibration and noise are bound to occur due to the complex structure.

[0009] Therefore, there is an urgent need to develop a gripper that can prevent squeezing accidents and reduce volume and weight with a simplified structure.

[0010] The purpose of the present invention is to solve such problems, and to provide a rotary electric gripper for robot mounting, which eliminates the space between links to prevent a pinching accident, forms a worm wheel-shaped gear groove on one side of the rotational axis of the link to directly mesh with the worm gear of the driving unit without a separate medium, thereby minimizing component parts and reducing volume and weight.

[0011] According to one embodiment of the technical idea of ​​the present invention for achieving the above object, a robot-mounted rotary electric gripper may include: a driving unit having a worm gear provided on a rotational shaft and providing a driving force; a pair of links having a worm wheel-shaped gear groove formed on a portion of an outer circumference of a portion of a rotational shaft to rotate while meshing with the worm gear, having fingers provided at an end for gripping a gripping object, and arranged to face each other on both sides of the worm gear; and a housing having the driving unit installed on one side and the pair of links axially coupled on the other side.

[0012] Additionally, the above link may have gear grooves formed at different positions so that each of the opposite sides corresponds to the worm gear.

[0013] Additionally, the finger may be formed of a curved rod that is bent inwardly.

[0014] In addition, the above-described robot-mounted rotary electric gripper may further include a tension portion to eliminate backlash between the worm gear and the gear groove by allowing the gear groove portion of the link and the worm gear to be in close contact with each other.

[0015] In addition, the tension part may include a first tension part, one end of which is fixed to one side of the housing and the other end of which is fixed to one side of the link, and the length of which extends in a straight direction when the link rotates; and a second tension part, one end of which is fixed to one side of the housing and the other end of which is fixed in a form of being wound in a circle toward the center of the rotational axis of the link, and the winding gap widens as the link expands in the rotational direction when the link rotates.

[0016] Additionally, the first tension part may be formed of a coil spring, and the second tension part may be formed of a spring spring.

[0017] In addition, on the rotation axis of the link, thrust bearings are provided on the upper and lower portions of the link, respectively, and a preload bolt can be fastened to pressurize the thrust bearings to eliminate backlash.

[0018] In addition, the above-described robot-mounted rotary electric gripper may further include an encoder unit for obtaining rotational position information of the link, and the encoder unit may include: a gear member installed at a position adjacent to the rotational axis of the link; and an absolute encoder installed on one side of the housing so as to rotate in engagement with the gear member and obtaining rotational information of the link.

[0019] In addition, the above-mentioned rotary electric gripper for robot mounting may further include a camera unit installed on one side of the housing for capturing an image of the gripping object.

[0020] Additionally, the camera unit may be configured as a single camera installed on one side of the housing or a stereo camera installed on one side and the other side of the housing.

[0021] In addition, the link includes an inner link having a worm wheel-shaped gear groove formed on a portion of the outer surface of a rotating shaft portion so as to rotate while engaging with the worm gear; and an outer link disposed on the outside of the inner link so as to be in close contact with the inner link; and the finger may be configured to be axially coupled to the ends of the inner link and the outer link, respectively, so as to grip an object to be gripped at a parallel position.

[0022] Additionally, the above link may have gear grooves formed at different positions so that each of the opposite sides corresponds to the worm gear.

[0023] In addition, the above-described robot-mounted rotary electric gripper further includes a third tension part to remove backlash for the worm gear and the gear groove by allowing the inner link and the outer link to be in close contact with each other, and the third tension part has one end fixed to the inside of the inner link and the other end fixed to the inside of the outer link, and can be extended in a straight direction when the link rotates.

[0024] In addition, a thrust bearing may be provided on the upper and lower portions of the outer link, respectively, at the portion where the housing and the outer link are axially coupled and at the portion where the outer link and the finger are axially coupled, and a preload bolt may be fastened to pressurize the thrust bearing to eliminate backlash.

[0025] In addition, the above robot-mounted rotary electric gripper may further include an encoder unit for obtaining rotational position information of the link, and the encoder unit may include a gear member installed at a position adjacent to the rotational axis of the inner link; and an absolute encoder installed on one side of the housing so as to rotate in engagement with the gear member and obtaining rotational information of the link.

[0026] In addition, the above-mentioned rotary electric gripper for robot mounting may further include a camera unit installed on one side of the housing for capturing an image of the gripping object.

[0027] Additionally, the camera unit may be configured as a single camera installed on one side of the housing or a stereo camera installed on one side and the other side of the housing.

[0028] In addition, the above-described robot-mounted rotary electric gripper may further include a moment measuring device for measuring a gripping force according to the rotational motion of the link.

[0029] Additionally, the moment measuring device may be either an electrostatic type or a strain gauge.

[0030] In addition, the moment measuring device is installed inside the inner link and can measure the gripping force of the finger through the gap with the inner link generated by the bending acting on the inner link during the gripping motion according to the link rotation motion.

[0031] In addition, the moment measuring device may include a PCB panel fixed to one side of the inner link but installed spaced apart from the inner link; and a distance detection sensor installed on one surface of the PCB panel and detecting a gap with the inner link.

[0032] In addition, two distance detection sensors can be installed on the upper and lower sides of the PCB panel, spaced apart from each other by a set distance.

[0033] In addition, the above distance detection sensors are installed two apart from each other and can measure the gripping force of the finger by compensating for the difference in the measured values ​​between them.

[0034] In addition, the above-described robot-mounted rotary electric gripper may further include a three-point gripping link that is hinge-coupled between the links on both sides to enable gripping an object to be gripped at three points together with the fingers.

[0035] In addition, the three-point grip link includes a first link hingedly connected to the outer links on both sides, and a second link hingedly connected to connect the first links on both sides and positioned horizontally; and when the link is opened, the second link can be lowered, and when the link is closed, the second link can be raised.

[0036] The rotary electric gripper for robot mounting according to the present invention has a structure in which a plurality of links are fastened in close contact with each other, thereby eliminating the space between the links, thereby having the effect of preventing crushing accidents in advance.

[0037] In addition, by forming a worm wheel-shaped gear groove on one side of the rotation axis of the link so that the worm wheel and the link are formed as one body, and are directly meshed with the worm gear of the driving unit without a separate medium to rotate, the component parts can be minimized, the volume and weight can be reduced, and there is an effect of reducing vibration and noise.

[0038] Figure 1 is a perspective view of a rotary electric gripper for robot mounting according to one embodiment of the present invention.

[0039] Figure 2 is a cross-sectional view of a rotary electric gripper for robot mounting according to one embodiment of the present invention.

[0040] Figure 3 is a perspective view of a link according to one embodiment of the present invention.

[0041] Figure 4 is an enlarged cross-sectional view of the first tension section.

[0042] Figure 5 is an enlarged cross-sectional view of the second tension section.

[0043] Figure 6 is an enlarged perspective view of an encoder section according to one embodiment of the present invention.

[0044] Figures 7 and 8 are examples of photographing images taken through a camera unit according to one embodiment of the present invention.

[0045] Figure 9 is a perspective view of a rotary electric gripper for robot mounting according to another embodiment of the present invention.

[0046] Figure 10 is a cross-sectional view of a rotary electric gripper for robot mounting according to another embodiment of the present invention.

[0047] Fig. 11 is a perspective view of a link according to another embodiment of the present invention.

[0048] Figure 12 is an enlarged cross-sectional view of the third tension section.

[0049] Fig. 13 is an enlarged perspective view of an encoder section according to another embodiment of the present invention.

[0050] Figure 14 is an enlarged cross-sectional view of the moment measuring device.

[0051] Figures 15 and 16 are examples of shooting images through a camera unit according to another embodiment of the present invention.

[0052] Fig. 17 is a cross-sectional view of the operating state of a rotary electric gripper for robot mounting according to another embodiment of the present invention equipped with a three-point grip link.

[0053] In order to fully understand the present invention, its operational advantages, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the contents described in the drawings, which illustrate preferred embodiments of the present invention.

[0054] Hereinafter, the present invention will be described in detail by describing preferred embodiments thereof with reference to the attached drawings. The same reference numerals in each drawing represent the same components.

[0055] The present invention relates to a robot-mounted rotary electric gripper, which eliminates the space between links to prevent a pinching accident, and forms a worm wheel-shaped gear groove on one side of the rotational axis of the link to directly mesh with the worm gear of the driving unit without a separate medium to perform a rotational motion, thereby minimizing component parts and reducing volume and weight.

[0056] FIG. 1 is a perspective view of a robot-mounted rotary electric gripper according to one embodiment of the present invention, FIG. 2 is a sectional view of a robot-mounted rotary electric gripper according to one embodiment of the present invention, FIG. 3 is a perspective view of a link according to one embodiment of the present invention, FIG. 4 is an enlarged cross-sectional view of a main part of a first tension part, FIG. 5 is an enlarged cross-sectional view of a main part of a second tension part, FIG. 6 is an enlarged perspective view of a main part of an encoder part according to one embodiment of the present invention, and FIGS. 7 and 8 are examples of photographing images taken through a camera part according to one embodiment of the present invention.

[0057] Referring to FIGS. 1 to 8, a rotary electric gripper for robot mounting (hereinafter referred to as “gripper”, 10) according to one embodiment of the present invention may largely include a driving unit (100), a link (200), and a housing (300).

[0058] The rotary electric gripper (10, 10') for robot mounting according to the present invention is a part that is mounted as an end effector of a conventional robot (e.g., a multi-joint robot) and performs the role of gripping to move a gripping target within a set position.

[0059] First, the driving unit (100) is a part that provides driving force by having a worm gear (120) mounted on a rotational axis, and can be formed in a form in which the worm gear (120) is fastened on the rotational axis of a motor (110) that provides normal rotational force.

[0060] For example, a worm gear (120) with a hollow interior is connected to the rotational axis of the motor (110), or the outer surface of the rotational axis of the motor (110) may be processed into a thread to form an integral structure in the shape of a worm gear.

[0061] That is, the worm gear (120) is provided on the rotation axis of the motor (110), so that the gear can rotate by the rotational force of the motor (110).

[0062] The above driving unit (100) can be installed so as to be seated within the motor receiving unit (310) of the housing (300) described later.

[0063] Next, the link (200) is a part in which a worm wheel-shaped gear groove (211) is formed on a portion of the outer surface of the rotating shaft to rotate in engagement with the worm gear (120), and a finger (230) for gripping a gripping object is provided at the end, and a pair of parts are arranged to face each other on both sides of the worm gear (120).

[0064] The above link (200) is a part that operates to open and open outward on both sides of the worm gear (120) or close and close inward as the motor (110) rotates and the worm gear (120) rotates accordingly, thereby enabling the gripping or placing of an object to be gripped.

[0065] The above link (200) may include a rotating portion (210) that is axially coupled to the gear groove (211) on both sides of the worm gear (120) and a pressing portion (220) that is formed to extend in the longitudinal direction from one side of the rotating portion (210).

[0066] Here, the rotating part (210) has a hollow interior and the hollow part serves as a rotation axis, which is a reference point for rotation, and a worm wheel-shaped gear groove (211) may be formed on a portion of one side of the outer circumferential surface to engage with the worm gear (120).

[0067] That is, the gear groove (211) is formed in the same shape as the gear groove of a conventional worm wheel, and is configured to rotate around the rotation axis as the worm gear (120) rotates.

[0068] Meanwhile, the pressurizing portion (220) is a rod-shaped portion extending in the longitudinal direction from one side of the rotating portion (210), and the length can be set in consideration of the volume of the object to be gripped.

[0069] Meanwhile, the above link (200) is positioned to face each other on both sides with respect to the above worm gear (120). At this time, the above link (200) may have gear grooves (211) formed at different positions so that each of the opposite sides corresponds to the above worm gear (120).

[0070] That is, the links (200) on both sides can have grooves formed at different height positions in the gear grooves (211) while the pressurizing portions (200) are vertically closed.

[0071] This is to configure the position of the groove differently so that there is a height difference equal to the pitch difference of the above worm gear (120).

[0072] Meanwhile, the finger (230) may be formed of a curved bar with each side of the finger bent inward.

[0073] This can be formed to be bent in a curved shape so that it can grip various sizes of gripping objects when the link (200) is gradually folded and brought into a closed state.

[0074] Accordingly, it is possible to stably grip various gripping objects of various sizes from small to large within the set size.

[0075] Next, the housing (300) is a part where the driving unit (100) is installed on one side and the pair of links (200) are axially coupled on the other side.

[0076] That is, the housing (300) provides a space for the driving unit (100) and the link (200) to be installed, allows the link (200) to be axially coupled, and serves as a medium for fastening to the arm end of a robot (not shown).

[0077] The housing (300) above is provided with a flange (320) having a bolt hole (not shown) formed therein for installation on a robot, and a motor receiving portion (310) in which the motor (110) can be mounted and received is provided on the upper portion of the flange (320), and a link rotation portion (330) for installing the link (200) so as to be rotatable above the motor receiving portion (310) may be provided.

[0078] The above motor receiving portion (310) is in a form in which both sides are open and exposed, so that both sides of the main body of the motor (110) can be partially exposed, and the worm gear (120) and the rotating portion (210) can be installed so that they are built inside and not exposed, and only the pressurizing portion (220) is exposed to the outside and can be installed so that it can rotate.

[0079] Meanwhile, the gripper (10) according to one embodiment of the present invention may further include a tension part (400) to remove backlash between the worm gear (120) and the gear groove (211) by allowing the gear groove (211) of the link (200) and the worm gear (120) to be in close contact with each other.

[0080] Typically, backlash is a gap intentionally created in the direction of movement of interlocking mechanical devices such as screws and gears, and is the minimum clearance that allows the screws and gears to move freely with minimal frictional resistance.

[0081] That is, it is essential to form backlash when manufacturing gears, but this backlash has the disadvantage of causing shock, vibration, and noise.

[0082] Meanwhile, in the gripper (10) of the present invention, the tension part (400) is a part configured to eliminate the disadvantage caused by such backlash.

[0083] The tension member (400) may include a first tension member (410) that is fixed at one end to one side of the housing (300) and the other end to one side of the link (200), and whose length extends in a straight direction when the link (200) rotates, and a second tension member (420) that is fixed at one end to one side of the housing (300) and whose other end is fixed in a form that is wound in a circle toward the center of the rotational axis of the link (200), and whose winding interval widens as the link (200) expands in the rotational direction when the link (200) rotates.

[0084] At this time, it is preferable that the first tension part (410) is made of a coil spring, and the second tension part (420) is made of a spring spring.

[0085] That is, as illustrated in the drawing, the first tension portion (410) can be extended in a straight line direction as the position of the fixed end portion changes when the link (200) rotates. At this time, the gear groove (211) portion of the link (200) can be brought into closer contact by increasing the contact area with the screw thread of the worm gear (120) due to the restoring force of the first tension portion (410).

[0086] That is, the gear home (211) portion of the above link (200) can be maintained in a state of constant contact and pulling with the worm gear (120), thereby improving the mutual fastening properties and obtaining a backlash removal effect, thereby reducing shock, vibration, and noise.

[0087] In addition, thrust bearings (not shown) are provided on the upper and lower portions of the link (200) on the rotation axis of the link (200), and a preload bolt (240) for pressurizing the thrust bearing to remove backlash can be fastened.

[0088] The above preload bolt (240) is a bolt that is fastened to apply a load in advance to increase the rigidity of the bearing or to eliminate a gap and prevent vibration, shock, noise and wear.

[0089] Additionally, the above preload bolt (240) can also serve as a rotation axis around which the link (200) rotates.

[0090] In addition, the above-mentioned preload bolt (240) may be provided to eliminate backlash, and also serves to securely fasten the link (200) to the housing (300) without shaking.

[0091] Meanwhile, the housing (300) may be formed in an open form so that the preload bolt (240) is exposed, or may be formed in a covered form so that the preload bolt (240) is not exposed to the outside.

[0092] That is, in some cases, it may be made so that the user can optionally adjust the preload bolt (240), or it may be made so that it is built in and covered so that the preload bolt (240) cannot be adjusted from the outside.

[0093] Meanwhile, the link (200) is manufactured as a single body, and the gear (211) is formed only on a portion of the outer surface of the rotating part (210). This is a form in which the entire body is manufactured first, and then the gear groove (211) is processed second, thereby completing the manufacturing process.

[0094] That is, since it is manufactured as a single body rather than being assembled from multiple individual parts, it can have high rigidity and significantly reduce noise and failure rate.

[0095] Meanwhile, the gripper (10) may further include an encoder unit (500) for obtaining rotational position information of the link (200).

[0096] The above encoder unit (500) may include a gear member (510) installed at a position adjacent to the rotation axis of the link (200) and an absolute encoder (520) installed on one side of the housing (300) so as to rotate while engaging with the gear member (510) to obtain rotation information of the link (200).

[0097] The above gear member (510) has a gear formed on the outer surface and can be installed at a position adjacent to the outer surface on one side of the rotating part (210).

[0098] The above absolute encoder (520) is a conventional absolute encoder that can always maintain an absolute position value regardless of the power status, scans a position code optically encoded in binary on a rotating disc, and has the characteristic of being able to check the current position information immediately after power is turned on even if a position movement occurs while power is not supplied.

[0099] At this time, the absolute encoder (520) may be placed below the worm gear (120).

[0100] In this way, the absolute encoder (520) is provided with a gear that rotates in mesh with the gear of the gear member (510), so that when the link (200) rotates, the gear member (510) rotates together with the link (200), thereby rotating the gear of the absolute encoder (520), thereby obtaining position information.

[0101] Meanwhile, the gripper (10) is installed on one side of the housing (300) and may further include a camera unit (600) for capturing a gripping image of the gripping target.

[0102] The above camera unit (600) can confirm through the captured image whether the gripper (10) has normally gripped the object to be gripped.

[0103] At this time, the camera unit (600) may be composed of a single camera (610) installed on one side of the housing (300) or a stereo camera (620) installed on one side and the other side of the housing (300).

[0104] That is, absolute position measurement is possible using the principle of stereo vision (trigonometry) for information captured and measured from each camera through two cameras.

[0105] Below, a rotary electric gripper for robot mounting according to another embodiment of the present invention is described in detail.

[0106] FIG. 9 is a perspective view of a robot-mounted rotary electric gripper according to another embodiment of the present invention, FIG. 10 is a sectional view of a robot-mounted rotary electric gripper according to another embodiment of the present invention, FIG. 11 is a perspective view of a link according to another embodiment of the present invention, FIG. 12 is an enlarged cross-sectional view of a main part of a third tension part, FIG. 13 is an enlarged perspective view of a main part of an encoder part according to another embodiment of the present invention, FIG. 14 is an enlarged cross-sectional view of a main part of a moment measuring device, FIGS. 15 and 16 are examples of a photographing state through a camera part according to another embodiment of the present invention, and FIG. 17 is a cross-sectional view of an operating state of a robot-mounted rotary electric gripper according to another embodiment of the present invention equipped with a three-point gripping link.

[0107] Referring to FIGS. 9 to 17, a robot-mounted rotary electric gripper (hereinafter referred to as “gripper”, 10’) according to another embodiment of the present invention is a gripper capable of parallel movement so as to grip an object to be gripped at a parallel position.

[0108] For this purpose, a link (200') and a finger (230') having a different structure from the link (200) of the gripper (10) described above can be formed.

[0109] A gripper (10') according to another embodiment of the present invention may basically include a driving unit (100), a link (200') and a housing (300).

[0110] Since the basic configuration of the above-described driving unit (100) and the housing (300) is the same as that of the gripper (10) described above, a description thereof is omitted.

[0111] Meanwhile, the link (200') of the gripper (10') according to another embodiment may include an inner link (200a) having a worm wheel-shaped gear groove (211') formed on a portion of the outer surface of the rotation shaft to rotate while engaging with the worm gear (120), and an outer link (200b) arranged on the outside of the inner link (200a) so as to be in close contact with the inner link (200b).

[0112] At this time, the finger (230') may be coupled to the ends of the inner link (200a) and the outer link (200b) to grip the gripping object at a parallel position.

[0113] The above link (200') is formed with a worm wheel-shaped gear groove (211') on a portion of the outer circumference of the rotation shaft to rotate while engaging with the worm gear (120), and is provided with a finger (230') at the end for gripping a gripping object, and is a part in which a pair is arranged facing each other on both sides of the worm gear (120).

[0114] The inner link (200a) is a part that operates to open and open outward on both sides of the worm gear (120) or close and close inward as the motor (110) rotates and the worm gear (120) rotates accordingly, thereby enabling the gripping or placing of the gripping object.

[0115] The inner link (200a) may include a rotating portion (210) that is axially coupled to the gear groove (211') on both sides of the worm gear (120) and a pressing portion (220) that is formed to extend in the longitudinal direction from one side of the rotating portion (210).

[0116] Here, the rotating part (210) has a hollow interior and serves as a rotation axis that is a reference point for rotation of the hollow part, and a gear groove (211') in the shape of a worm wheel can be formed on a portion of one side of the outer circumferential surface to engage with the worm gear (120).

[0117] That is, the gear groove (211') is formed in the same shape as the gear groove of a conventional worm wheel, and is configured to rotate around the rotation axis as the worm gear (120) rotates.

[0118] Meanwhile, the pressurizing portion (220) is a rod-shaped portion extending in the longitudinal direction from one side of the rotating portion (210), and the length can be set in consideration of the volume of the object to be gripped.

[0119] Meanwhile, the inner link (200a) is positioned oppositely on both sides with respect to the worm gear (120), and at this time, the inner link (200a) may have gear grooves (211') formed at different positions so that each of the opposite sides corresponds to the worm gear (120).

[0120] That is, the inner links (200a) on both sides can have grooves formed at different height positions in the gear grooves (211') while the pressurizing portions (200) are vertically closed.

[0121] This means that the position of the groove may be different so that there is a height difference equal to the pitch difference of the worm gear (120).

[0122] Meanwhile, the rotating part (210) of the inner link (200a) may be formed with a diameter smaller on the opposite side than the part where the gear groove (211') is formed based on the rotation axis.

[0123] That is, the above-mentioned rotating part (210) is formed in a shape in which a portion is cut from a circular shape, and this is to enable it to be in close contact with the outer link (200b).

[0124] Meanwhile, the outer link (200b) is a part that is positioned externally in close contact with the inner link (200a), and is installed parallel to the inner link (200a) to enable the finger (230') to operate in parallel.

[0125] That is, the inner link (200a) and the outer link (200b) are in close contact with each other and have a rotation axis at each end, and the fingers (230') are axially coupled to the two rotation axes at the ends of the inner link (200a) and the outer link (200b), so that the inner link (200a) is rotated and the outer link (200b) rotates, enabling the parallel movement of the fingers (230').

[0126] At this time, a third tension part (430) may be further included to remove backlash for the worm gear (120) and the gear groove (211') by allowing the inner link (200a) and the outer link (200b) to be in close contact with each other.

[0127] The third tension member (430) is fixed at one end to the inside of the inner link (200a), and at the other end to the inside of the outer link (200b), but can be extended in a straight line when the link (200') rotates.

[0128] That is, by the third tension portion (430), the inner link (200a) and the outer link (200b) can be in a close contact state without being separated from each other.

[0129] At this time, the third tension part (430) may be made of a coil spring.

[0130] That is, as shown in the drawing, the third tension part (430) allows the inner link (200a) and the outer link (200b) to extend in a straight direction and have a restoring force while restricting the tendency of the inner link (200a) and the outer link (200b) to separate from each other when the link (200') rotates.

[0131] At this time, the gear groove (211') portion of the link (200') can be brought into closer contact by increasing the contact area with the screw thread of the worm gear (120) due to the restoring force of the third tension portion (430).

[0132] That is, the gear home (211) portion of the above link (200) can be maintained in a state of constant contact and pulling with the worm gear (120), thereby improving the mutual fastening properties and obtaining a backlash removal effect, thereby reducing shock, vibration, and noise.

[0133] Meanwhile, at the portion where the housing (300) and the outer link (200b) are axially connected and at the portion where the outer link (200b) and the finger (230') are axially connected, thrust bearings (not shown) are provided on the upper and lower portions of the outer link (200b), respectively, and a preload bolt (240) for pressurizing the thrust bearing to remove backlash can be fastened.

[0134] The above preload bolt (240) is a bolt that is fastened to apply a load in advance to increase the rigidity of the bearing or to eliminate a gap and prevent vibration, shock, noise and wear.

[0135] In addition, the above-mentioned preload bolt (240) can also serve as a rotation axis on which the inner link (200a), outer link (200b), and finger (230') rotate when the above-mentioned link (200') rotates.

[0136] In addition, the above-mentioned preload bolt (240) may be provided to eliminate backlash, and also serves to securely fasten the link (200') to the housing (300) without shaking.

[0137] Meanwhile, the housing (300) may be formed in an open form so that the preload bolt (240) is exposed, or may be formed in a covered form so that the preload bolt (240) is not exposed to the outside.

[0138] That is, in some cases, it may be made so that the user can optionally adjust the preload bolt (240), or it may be made so that it is built in and covered so that the preload bolt (240) cannot be adjusted from the outside.

[0139] Meanwhile, the gripper (10) may further include an encoder unit (500) for obtaining rotational position information of the link (200).

[0140] The above encoder unit (500) may include a gear member (510) installed at a position adjacent to the rotation axis of the inner link (200a) and an absolute encoder (520) installed on one side of the housing (300) so as to rotate while engaging with the gear member (510) to obtain rotation information of the link (200).

[0141] The above gear member (510) has a gear formed on the outer surface and can be installed at a position adjacent to the outer surface on one side of the rotating part (210).

[0142] The above absolute encoder (520) is a conventional absolute encoder that can always maintain an absolute position value regardless of the power status, scans an optically binary-encoded position code on a rotating disc, and has the characteristic of being able to check the current position information immediately after power is turned on even if a position movement occurs while power is not supplied.

[0143] At this time, the absolute encoder (520) may be placed below the worm gear (120).

[0144] In this way, the absolute encoder (520) is provided with a gear that rotates in mesh with the gear of the gear member (510), so that when the link (200) rotates, the gear member (510) rotates together with the link (200), thereby rotating the gear of the absolute encoder (520), thereby obtaining position information.

[0145] Meanwhile, the gripper (10) is installed on one side of the housing (300) and may further include a camera unit (600) for capturing a gripping image of the gripping target.

[0146] The above camera unit (600) can confirm through the captured image whether the gripper (10) has normally gripped the object to be gripped.

[0147] At this time, the camera unit (600) may be composed of a single camera (610) installed on one side of the housing (300) or a stereo camera (620) installed on one side and the other side of the housing (300).

[0148] That is, absolute position measurement is possible using the principle of stereo vision (trigonometry) for information captured and measured from each camera through two cameras.

[0149] Meanwhile, the gripper (10') of the present invention may further include a moment measuring device (700) for measuring the gripping force according to the rotational motion of the link (200').

[0150] The above moment measuring device (700) is a part for checking the gripping force through the degree of bending of the link (200') when the link (200') rotates and performs a gripping action.

[0151] The moment measuring device (700) is installed inside the inner link (200a) and can measure the gripping force of the finger through the gap with the inner link generated by the bending acting on the inner link (200a) during the gripping motion according to the rotational motion of the link (200').

[0152] That is, it is possible to measure in real time the degree of force with which the finger (230') is gripping the object to be gripped through the moment measuring device (700).

[0153] The above moment measuring device (700) may be either an electrostatic type or a strain gauge.

[0154] For example, a moment measuring device (700) of an electrostatic type may include a PCB panel (710) that is fixed to one side of the inner link (200a) but installed spaced apart from the inner link (200a), and a distance detection sensor (720) that is installed on one side of the PCB panel (710) and detects a distance from the inner link (200a).

[0155] At this time, two distance detection sensors (720) can be installed on the upper and lower sides of the PCB panel (710) with a set distance between them.

[0156] That is, the two distance detection sensors (720) are installed spaced apart from each other and can measure the gripping force of the finger through compensation according to the difference in the measured values ​​between them.

[0157] That is, since the inner link (200a) may have a difference in the degree of bending depending on the position of the inner link (200a) in a gripping situation, each distance detection sensor (720) installed on the upper and lower sides may measure different values, and by utilizing this difference, an accurate bending degree value of the inner link (200a) can be derived.

[0158] Meanwhile, the gripper (10') of the present invention may further include a three-point gripping link (800) that is hinge-coupled between the links (200') on both sides to enable gripping an object to be gripped at three points together with the fingers (230').

[0159] The above three-point grip link (800) may include a first link (810) hingedly connected to the outer links (200b) on both sides, and a second link (820) hingedly connected to the first links (810) on both sides and positioned horizontally.

[0160] At this time, when the link (200') is opened, the second link (820) may be lowered, and when the link (200') is closed, the second link (820) may be raised.

[0161] Through this, it is possible to have a structure that can stably grip objects ranging from small to large.

[0162] The above-described rotary electric gripper (10, 10') for robot mounting according to various embodiments of the present invention is a type in which a link (200, 200') is connected and rotated through a worm gear method, and the link (200, 200') equipped with a worm wheel is rotated by the driving of the worm gear (120) of the driving unit (100), but even if the power is cut off, the worm gear (120) can remain stopped, and accordingly, the gripping force for gripping an object can be maintained at all times, so that an overload of the motor (110) can be prevented.

[0163] The above-described rotary electric gripper for robot mounting according to the technical idea of ​​the present invention has a structure in which a plurality of links are fastened in close contact with each other, thereby eliminating the space between the links and thus preventing accidents of squeezing in advance. In addition, a worm wheel-shaped gear groove is formed on one side of the rotational axis of the link so that the worm wheel and the link are formed as one body, thereby directly meshing with the worm gear of the driving unit without a separate medium to perform a rotational motion, thereby minimizing the number of components, reducing the volume and weight, and reducing vibration and noise.

[0164] As described above, the best practice embodiments have been disclosed in the drawings and specifications. While specific terms have been used herein, they are used solely for the purpose of describing the present invention and are not intended to limit the meaning or scope of the invention as defined in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent embodiments are possible. Accordingly, the true technical protection scope of the present invention should be defined by the technical spirit of the appended claims.

[0165]

[0166] The present invention is implemented as a rotary electric gripper for robot mounting, which can minimize component parts and reduce volume and weight by eliminating the space between links to prevent a pinching accident and forming a worm wheel-shaped gear groove on one side of the rotational axis of the link to directly mesh with the worm gear of the driving unit without a separate medium to perform a rotational motion, but can be applied to various industrial fields within the scope of the configuration of the present invention.

Claims

1. A driving unit having a worm gear mounted on a rotating shaft and providing driving force; A pair of links having a worm wheel-shaped gear groove formed on a portion of the outer surface of the rotating shaft to rotate in engagement with the worm gear, and having fingers for gripping a gripping object provided at the end, and arranged oppositely on both sides of the worm gear; and A rotary electric gripper for robot mounting, characterized by including a housing in which the driving unit is installed on one side and the pair of links are axially coupled on the other side.

2. In paragraph 1, The above-mentioned rotary electric gripper for robot mounting is, A robot-mounted rotary electric gripper characterized in that it further includes a tension part for eliminating backlash between the worm gear and the gear groove by allowing the gear groove part of the link and the worm gear to be in close contact with each other.

3. In paragraph 2, The above tension part, A first tension part, which is fixed to one side of the housing and the other side of the link, and whose length extends in a straight direction when the link rotates; and A rotary electric gripper for robot mounting, characterized in that it includes a second tension part, which is fixed to one side of the housing and the other end is fixed in a form of being wound in a circle toward the center of the rotational axis of the link, and the winding gap widens as the link expands in the rotational direction when the link rotates.

4. In paragraph 1, The above-mentioned rotary electric gripper for robot mounting is, Further comprising an encoder section for obtaining rotational position information of the above link, The above encoder part, A gear member installed at a position adjacent to the rotation axis of the above link; and A robot-mounted rotary electric gripper characterized by including an absolute encoder installed on one side of the housing to rotate in engagement with the gear member and obtain rotation information of the link.

5. In paragraph 1, The above-mentioned rotary electric gripper for robot mounting is, A robot-mounted rotary electric gripper, characterized in that it further includes a camera unit installed on one side of the housing and for capturing an image of a gripping object.

6. In paragraph 1, The above link is, An inner link having a worm wheel-shaped gear groove formed on a portion of the outer surface of the rotating shaft to rotate in mesh with the above worm gear; and An outer link is disposed outside the inner link so as to be in close contact with the inner link; The above fingers, A robot-mounted rotary electric gripper characterized in that each of the inner link and outer link ends is axially coupled to grip an object to be gripped at a parallel position.

7. In paragraph 6, The above-mentioned rotary electric gripper for robot mounting is, It further includes a third tension part to eliminate backlash for the worm gear and the gear groove by allowing the inner link and the outer link to be in close contact with each other. The third tension part is, A rotary electric gripper for robot mounting, characterized in that one end is fixed to the inside of the inner link and the other end is fixed to the inside of the outer link, and the length thereof extends in a straight direction when the link rotates.

8. In paragraph 6, The above-mentioned rotary electric gripper for robot mounting is, Further comprising an encoder section for obtaining rotational position information of the above link, The above encoder part, A gear member installed at a position adjacent to the rotation axis of the inner link; and A robot-mounted rotary electric gripper characterized by including an absolute encoder installed on one side of the housing to rotate in engagement with the gear member and obtain rotation information of the link.

9. In paragraph 6, The above-mentioned rotary electric gripper for robot mounting is, A robot-mounted rotary electric gripper further comprising a moment measuring device for measuring a gripping force according to the rotational motion of the link.

10. In paragraph 6, The above-mentioned rotary electric gripper for robot mounting is, A robot-mounted rotary electric gripper characterized by further including a three-point gripping link that is hinge-joined between the links on both sides to enable gripping an object to be gripped at three points together with the fingers.

Images