Clamp for door and control method thereof

Abstract

The present invention relates to picking up a door loaded on a tray using a gripper mounted on a robot hand in a smart factory. The jig includes: a frame mounted on a tool changing device of a robot hand; and a pick-up unit which is installed on the front surface of the frame, applies pressure to each of an upper point location and a lower point location of an opening formed in an inner panel of the door through a bundle pin positioner, and restricts each of the upper point location and the lower point location; and a pressure control valve for adjusting the pressure of the guide cylinder. The jig further includes: a side clamping unit mounted on the frame and holding a side point of the opening by a fixing positioner and a gripper operated under a driving force of a clamping cylinder; and a control unit that adjusts a moving distance of the robot hand on the basis of a distance difference between the side clamping unit and the inner plate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0076734, filed on Jun. 15, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a clamp for a door and a control method thereof, and more particularly, to a clamp for a door for taking out a door panel mounted on a robot arm and loaded on a pallet and a control method thereof. Background Art

[0004] Generally, in order to automate the door panel installation process in a smart factory, the pallet providing the door panels must be placed on a designated rack, and the robot must automatically pick up and remove the door panels. In this automated process, in order to prevent the assembly line from being interrupted (stopped), it is necessary to ensure smooth logistics turnover between real pallets loaded with a certain number of door panels and empty pallets without door panels. Therefore, a large number of pallets need to be manufactured and operated to achieve smooth logistics turnover.

[0005] A separator is installed on the pallet to fix the loaded door panel in the vertical direction. The separator plays an important role in determining the pick-up position within the pallet so that the robot can remove the door panel through the clamp. However, the separator may be twisted or deformed during use, which may cause position errors of the separators of each pallet. Therefore, when a large number of pallets are used, if position errors of the separators of each pallet occur, an accident may occur in which the door panel cannot be removed due to the change of the pick-up position of the robot, which may cause problems such as assembly line interruption and reduced operation rate in smart factories.

[0006] In order to prevent such a production line interruption problem, when manufacturing a new pallet, a pallet teaching management work can be performed, a standard pallet for indicating the pick-up position of the robot door panel is selected, and the remaining pallets are customized and confirmed to have the same pick-up position as the above standard pallet. However, the pallet teaching management work of the prior art has the problem that regular inspections and high costs are required to maintain and manage the accuracy of the pallet even during mass production, and there is a disadvantage that the above problem continues to occur.

[0007] In the prior art, in view of the differences in the shape and height of the inner panels of various types of doors, the clamp for the door utilizes an upper clamp and a lower clamp that are movably mounted through an electric cylinder and a guide rail. However, the clamp for the door panel of the prior art clamps the door panel in a point contact manner, and there is a problem that if the loading position of the door panel in the pallet changes, the door panel cannot be picked up, thereby affecting the operation rate. In addition, when using an electric cylinder and a guide rail, the disadvantage of the clamp for the door of the prior art is that the weight of the clamp increases, which affects the workload of the robot, and there is a problem that when the electric cylinder fails, it takes a lot of time to repair the failure.

[0008] The matters described in this background technology section are for enhancing understanding of the background of the present invention and may include matters that are not known to one of ordinary skill in the art to which the present technology belongs. Summary of the invention

[0009] The present invention provides a clamp for doors and a control method thereof. For each pallet, the clamp can absorb the position error of the door panel so that a robot arm can pick up the door panel and can adapt to the internal shapes of door panels of multiple vehicle models so that the clamp can be universally used on an assembly line.

[0010] According to one aspect of the present invention, a fixture installed on a robot arm for picking up doors loaded on a pallet in a smart factory may include: a frame installed on a tool changing device of the robot arm; and a picking unit, which is installed on the front of the frame and applies pressure to each of the upper and lower points of an opening formed in an inner plate of the door through a beam-type pin locator (i.e., a beam pin locator) and restricts the upper and lower points. The fixture also includes: a pressure control valve for adjusting the pressure of each guide cylinder applied to the picking unit; a side clamping unit, which is installed on the front of the frame and uses a fixed locator and a clamp operated under the driving force of the clamping cylinder to hold (e.g., clamp) the side point of the opening; and a control unit that adjusts the moving distance of the robot arm by measuring the distance difference between the side clamping unit and the inner plate using a laser sensor.

[0011] Furthermore, the frame may include: a first vertical frame installed at the front side, on which the pickup unit is installed; and a second vertical frame disposed in parallel with the first vertical frame, on which the side clamping unit is installed.

[0012] In addition, the picking unit may include an upper picking unit and a lower picking unit, wherein the upper picking unit utilizes the pressure of the guide cylinder to transfer force in an upward direction through the pin locator to limit the upper point position of the inner plate; and the lower picking unit utilizes the pressure of the guide cylinder to transfer force in a downward direction through the pin locator to limit the lower point position of the inner plate.

[0013] In addition, the bundle-type pin locator may include: a plurality of hexagonal pin locators constructed in a bundle-type structure at the portion in contact with the inner plate; a support rod extending from the lower portion of the plurality of hexagonal pin locators in the longitudinal direction and penetrating a horizontal plate formed in the shell; a spring installed around the support rod and supporting the lower portion of the plurality of hexagonal pin locators; a fixing plate installed at the lower end of the support rod and fixed on the lower surface of the horizontal plate; and a laser beam sensor installed at the lower portion of the shell in the horizontal direction and sensing the descending position of the plurality of hexagonal pin locators in contact with the inner plate.

[0014] Furthermore, each of the plurality of hexagonal pin locators has a regular hexagonal cross-sectional shape and may form a honeycomb pattern-like anti-slip pattern on an upper surface thereof contacting the inner panel.

[0015] In addition, multiple hexagonal pin locators can be closely arranged with adjacent regular hexagonal sections facing each other, and each of the multiple hexagonal pin locators can move up and down by the weight of the inner plate in contact with its upper surface and the elastic force of the spring used to support the lower part of the inner plate.

[0016] In addition, the laser beam sensor may include a light emitting unit and a light receiving unit, and sense the descending position of the fixing plate to reach the reference position using a laser beam emitted from the light emitting unit and horizontally received by the light receiving unit. The laser beam sensor may then send a descending sensing signal to the pressure control valve.

[0017] In addition, the pressure control valve may include an upper pressure control valve and a lower pressure control valve respectively configured to correspond to the upper pickup unit and the lower pickup unit, and during initial operation of the upper pickup unit and the lower pickup unit, the upper pressure control valve and the lower pressure control valve may set the pressure of the guide cylinder to a low pressure below a critical pressure to prevent damage to the inner panel.

[0018] In addition, the upper pressure control valve and the lower pressure control valve can maintain a low pressure below the critical pressure until a descent sensing signal is received from the laser beam sensor in the inner plate contact step of the beam type pin locator. When the descent sensing signal is received, the upper pressure control valve and the lower pressure control valve can increase the pressure of the guide cylinder by a certain amount to strengthen the limiting force of the inner plate.

[0019] Furthermore, while the fixing positioner is placed on the outer surface of the side point, the side clamping unit may clamp or hold the inner surface of the side point with the clamper rotating about the hinge axis through the forward operation of the clamping cylinder.

[0020] In addition, the control unit may control the upper point and the lower point to be restricted by using the picking unit after the side clamping unit completes clamping of the side point.

[0021] In addition, the control unit may include a robot controller that measures the measured distance from the inner panel through a laser sensor and derives a distance difference between the measured distance and a reference distance set based on robot teaching. The control unit may include a gripper controller that is linked to the robot controller and controls the operation of the picking unit and the side gripping unit.

[0022] Furthermore, the gripper controller may control the pressing force of the bundle type pin positioner formed at the front end of the pickup unit in stages through the pressure control valve.

[0023] According to one aspect of the present invention, a control method for a fixture installed on a robot arm for picking up doors loaded on a pallet in a smart factory includes: moving the fixture to a set picking position of the door through motion control of the robot arm; and adjusting the moving distance of the robot arm by measuring the distance difference between the side clamping unit and the inner plate using a laser sensor installed on the side clamping unit of the fixture. The control method also includes: using the side clamping unit to hold the side point position of the inner plate; and applying pressure to the upper point position and the lower point position of the inner plate and restricting the upper point position and the lower point position through a beam pin locator constructed in the picking unit of the fixture.

[0024] Furthermore, adjusting the movement distance of the robot hand includes measuring the measured distance from the inner plate using a laser sensor; and deriving a distance difference by subtracting a reference distance set based on the robot hand teaching from the measured distance.

[0025] Furthermore, adjusting the movement distance of the robot hand includes: comparing the distance difference with the gripping operation allowable value of the side gripping unit; and when the distance difference exceeds the allowable value, adjusting the position of the gripper in the front-rear direction by the distance difference.

[0026] In addition, the adjustment of the upper point position and the lower point position may include: in the initial operation step of the pickup unit, controlling each guide cylinder to a low pressure by setting the pressure control valve to a low pressure; and maintaining the low pressure while the beam-type pin locator is in contact with the inner plate, and monitoring by a laser beam sensor whether a portion of the hexagonal pin locator in contact with the inner plate is lowered to a reference position. The control method also includes: when a descending sensing signal of a portion of the hexagonal pin locator is received from the laser beam sensor, increasing the pressure of the guide cylinder by a certain amount to strengthen the limiting force of the inner plate with an increased force.

[0027] According to an embodiment of the present invention, by providing a jig capable of performing robot position correction for position changes of doors loaded on each pallet, it is possible to prevent line interruption and improve the operation rate in a smart factory.

[0028] In addition, by adopting the pick-up unit of the beam-type pin locator, a fixture capable of coping with inner panel position errors and shape height changes is provided, reducing the cost of pallet teaching management and enabling flexible manufacturing of multiple vehicles.

[0029] Furthermore, by not using a heavy-duty clamp using a conventional electric cylinder and a guide rail, the use of a lightweight clamp of the present invention can reduce the load on the robot and reduce energy usage. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A door installation process using a clamp for a door according to an embodiment of the present invention is schematically illustrated.

[0031] Figure 2 and Figure 3 A clamp for a door according to an embodiment of the present invention and a door panel picking state using the clamp are shown.

[0032] Figure 4 The detailed configuration of the bundle type pin locator according to the embodiment of the present invention is shown.

[0033] Figure 5 According to an embodiment of the present invention, Figure 2 0 is a cross-sectional view taken along line AA in FIG. 1 and illustrates an operating state of the picking unit relative to a position error of the door.

[0034] Figure 6 According to an embodiment of the present invention, Figure 2 0 is a cross-sectional view taken along line BB in FIG. 1 , and shows a state where clamping is impossible due to a door panel loading position error within the pallet.

[0035] Figure 7 A solution to the change in the loading position of door panels in a pallet according to an embodiment of the present invention is shown.

[0036] Figure 8 Showing the height differences of the inner panel shapes of various types of doors according to an embodiment of the present invention.

[0037] Fig. 9 A control method of a pickup unit corresponding to doors of multiple models with limited cross-sectional height differences according to an embodiment of the present invention is shown.

[0038] Fig.10 and Fig.11 is a flowchart schematically illustrating a control method of a clamp for a door according to an embodiment of the present invention.

[0039] <Description of Reference Numerals>

[0040] 10: Robot arm 11: Tool changing device

[0041] 20: Tray 21: Divider

[0042] 30: Door 31: Inner panel

[0043] 32: Opening 40: Pallet rack

[0044] 50: Body 100: Fixture

[0045] 110: frame 111: first vertical frame

[0046] 112: Second vertical frame 113: Tool installation part

[0047] 120: Pick-up unit 120-1: Upper pick-up unit

[0048] 120-2: Lower pick-up unit 121: Beam pin locator

[0049] 1211: Hexagonal pin locator 1212: Support rod

[0050] 1213: Fixed plate 1214: Spring

[0051] 1215: Shell 1216: Horizontal plate

[0052] 1217: Anti-slip pattern 1218: Laser beam sensor

[0053] 122: Guide cylinder 130: Side clamping unit

[0054] 131: Fixed positioner 132: Clamp

[0055] 133: Clamping cylinder 134: Laser sensor

[0056] 135: hinge shaft 140: pressure control valve

[0057] 140-1: Upper pressure control valve 140-2: Lower pressure control valve

[0058] 150: Control unit 151: Robot controller

[0059] 152: Fixture controller P1: upper point

[0060] P2: Lower point P3: Side point DETAILED DESCRIPTION

[0061] The present invention is described more fully hereinafter with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily implement the embodiments of the present invention.

[0062] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present invention. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. It should also be understood that when the terms "include" and / or "comprise" are used in this article, the existence of the features, integers, steps, actions, elements and / or parts mentioned is specified, but the existence or addition of one or more and / or groups thereof of other features, integers, steps, actions, elements, parts is not excluded. As used herein, the term "and / or" includes any one or all combinations of the relevant listed items.

[0063] Throughout the specification, the terms first, second, A, B, (a), (b), etc. may be used to describe various components, but the components are not limited by these terms. These terms are only used to distinguish the components from other components, and the nature, order or sequence of the components are not limited by these terms.

[0064] Throughout the specification, when a component is referred to as being "connected to" or "coupled to" another component, the component may be connected or coupled to the other component, or there may be intervening components. Conversely, when a component is referred to as being "directly connected to" or "directly coupled to" another component, there are no intervening components. When a component, device, element, etc. of the present invention is described as having a purpose or performing an operation, function, etc., the component, device, or element should be considered herein to be "configured to" satisfy that purpose or perform that operation or function.

[0065] Throughout the specification, the terms used are only for the purpose of describing specific embodiments and are not intended to limit the present invention. Unless the context clearly dictates otherwise, a singular expression includes a plural expression.

[0066] In addition, it should be understood that one or more of the following methods or aspects thereof can be performed by at least one or more controllers. The term "controller" can refer to a hardware device including a memory and a processor. The memory is configured to store program instructions, and the processor is specifically programmed to execute program instructions to perform one or more processes described in more detail below. The controller can control the operation of a unit, module, component, device, or the like, as described herein. It should also be understood that, as will be understood by those of ordinary skill in the art, the following methods can be performed by a device including a controller and one or more other components.

[0067] Now, a clamp for a door and a control method thereof according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0068] Figure 1 A door installation process using a clamp for a door according to an embodiment of the present invention is schematically illustrated.

[0069] Figure 2 and Figure 3 The configuration of a clamp for a door according to an embodiment of the present invention and a door panel picking state using the clamp are shown.

[0070] refer to Figures 1 to 3 The jig 100 is installed on a robot 10 used for a door installation process in a smart factory. The jig 100 is used to pick up and take out a door panel 30 loaded on a pallet 20 and assemble the door panel 30 to a vehicle body 50.

[0071] For example, a pallet 20 is loaded with a plurality of door panels 30 (hereinafter referred to as "doors" for convenience) in an upright state through a partition 21, and is moved to a set pallet rack 40 by a logistics transportation tool such as an automatic guided vehicle (AGV) or an autonomous mobile robot (AMR), and then waits.

[0072] The fixture 100 is moved to the set pick-up position of the door 30 by the motion control of the robot 10 having more than 6 axes of freedom. In addition, the fixture 100 picks up the door 30 by limiting the upper point P1, the lower point P2 and the side point P3 of the opening 32 formed in the inner plate 31 of the door 30 through the mechanical unit (see 120-1, 120-2 and 130 below). Here, picking up means that the upper point P1, the lower point P2 and the side point P3 of the opening 32 are successfully limited (fixed) by the fixture 100, so that the door 30 is in a state that can be taken out (transferred). Accordingly, the robot 10 can take out the door 30 that has been successfully picked up by the fixture 100 from the tray 20.

[0073] As described above, in the prior art, when the partition 21 for fixing the door panel vertically loaded on the pallet 20 in the vertical direction is twisted or deformed, there is a problem of causing position error, and this position error may result in failure to pick up the door 30 from each pallet.

[0074] Therefore, the present invention aims at the problem that the door cannot be picked up due to the position error of each pallet, and provides a clamp 100 for a universal door of multiple models, which realizes the door panel picking by absorbing the position error of each pallet.

[0075] The clamp 100 according to the embodiment of the present invention includes a frame 110 , a pickup unit 120 , a side clamping unit 130 , a pressure control valve 140 , and a control unit 150 .

[0076] The frame 110 is mounted on the tool changing device 11 of the robot hand 10 via a tool mounting portion 113 formed on the rear surface thereof.

[0077] The frame 110 includes a first vertical frame 111 installed at the front side thereof and mounting the pickup unit 120 , and a second vertical frame 112 disposed parallel to the first vertical frame 111 and mounting the side clamping unit 130 .

[0078] The pickup unit 120 applies pressure to and regulates each of an upper point P1 and a lower point P2 of the opening 32 formed in the inner panel 31 of the door 30 through a beam type pin positioner 121 using a spring.

[0079] The pressure control valve 140 controls the pressure applied to the guide cylinder of the pickup unit 120 .

[0080] The side clamping unit 130 clamps the side point P3 of the opening 32 using a fixed positioner 131 and a clamper 132 operated by a driving force of a clamping cylinder 133 .

[0081] The control unit 150 corrects the moving distance of the robot hand 10 by measuring the distance deviation from the inner plate 31 through the laser sensor 134 before clamping.

[0082] The pickup unit 120 includes an upper pickup unit 120-1 and a lower pickup unit 120-2 installed on the first vertical frame 111. The upper pickup unit 120-1 and the lower pickup unit 120-2 have the same configuration but have different operation directions according to installation positions.

[0083] For example, the upper pickup unit 120 - 1 may limit the upper point P1 of the inner panel 31 by the bundle type pin positioner 121 which transmits force in an upward direction using the pressure of the guide cylinder 122 .

[0084] In addition, the lower pickup unit 120 - 2 may limit the lower point P2 of the inner panel 31 by the bundle type pin positioner 121 , which transmits force in a descending (downward) direction using the pressure of the guide cylinder 122 .

[0085] Figure 4 The detailed configuration of the bundle type pin locator according to the embodiment of the present invention is shown.

[0086] refer to Figure 4 In the bundle-type pin locator 121 according to an embodiment of the present invention, a plurality of hexagonal pin locators 1211 are arranged in a bundle-type structure at a position in contact with the inner panel 31, so that even if the position and / or shape of the inner panel 31 is changed in various ways due to a position error of the tray 20, it can be restricted.

[0087] The bundle-type pin locator 121 includes: a plurality of hexagonal pin locators 1211 constructed in a bundle-type structure and arranged at a position in contact with the inner plate 31, a support rod 1212 extending from the lower portion of the hexagonal pin locator 1211 in a longitudinal direction and penetrating a horizontal plate 1216 formed in a shell 1215, a fixing plate 1213 installed at the lower end of the support rod 1212 and fixed on the lower surface of the horizontal plate 1216, a spring 1214 installed around the support rod 1212 and supporting the lower portion of the hexagonal pin locator 1211, and a laser beam sensor 1218, which is installed at the lower portion of the shell 1215 in a horizontal direction and senses the falling position of the hexagonal pin locator 1211 in contact with the inner plate 31.

[0088] Each hexagonal pin locator 1211 is a pin having a regular hexagonal cross-sectional shape, and may form a comb-shaped anti-slip pattern 1217 on an upper surface thereof contacting the inner panel 31 of the door.

[0089] The hexagonal pin locators 1211 may be closely arranged in the longitudinal direction of the pin to form a bundle-type structure, with adjacent regular hexagonal cross-sections facing each other.

[0090] Each hexagonal pin locator 1211 can move up and down by the weight of the inner plate 31 in contact with its upper surface and the elastic force of the spring 1214 for supporting its lower part. At this time, each hexagonal pin locator 1211 can move up and down according to the shape of the inner plate 31 in contact with its upper surface.

[0091] The laser beam sensor 1218 senses the descending position of the fixing plate 1213 installed at the lowermost end of the hexagonal pin locator 1211 .

[0092] The laser beam sensor 1218 senses that the descending position of the fixing plate 1213 reaches the reference position using a laser beam horizontally transmitted and received through the light emitting unit 1218a and the light receiving unit 1218b, and transmits a descending sensing signal to the pressure control valve 140. Therefore, the pressure control valve 140 can receive the descending sensing signal from the laser beam sensor 1218, thereby determining the time when the inner panel 31 is finally placed on the beam type pin locator 121.

[0093] Figure 5 According to an embodiment of the present invention, Figure 2 0 is a cross-sectional view taken along line AA in FIG. 1 and illustrates an operating state of the picking unit relative to a position error of the door.

[0094] first, Figure 5(A) shows a state where the upper point P1 and the lower point P2 of the inner panel 31 normally (without position error) loaded on the pallet 20 are restricted by the upper pickup unit 120 - 1 and the lower pickup unit 120 - 2 , respectively.

[0095] Under the pressure of each guide cylinder 122, a force is applied to the bundle type pin locator 121, so that a part of the hexagonal pin locator 1211a in contact with the inner plate 31 retreats, while the remaining hexagonal pin locator 1211b remains in place. At this time, the bundle type pin locator 121 of the bundle structure can fix the inner plate 31 under the pressure of a part of the hexagonal pin locator 1211a, and the remaining hexagonal pin locator 1211b forms a step around the inner plate 31 to prevent the inner plate 31 from detaching, thereby completing the picking.

[0096] Next, Figure 5 (B) shows a state where, when a position error "e" of the tray 20 occurs, the upper point P1 and the lower point P2 of the inner plate 31 whose loading position has been changed are restricted by the upper pickup unit 120-1 and the lower pickup unit 120-2, respectively.

[0097] As described above, even in a state where the position error e of the pallet 20 occurs, the bundle type pin locator 121 of the bundle type structure can fix the inner plate 31 whose loading position is changed due to the pressurization of a part of the hexagonal pin locator 1211a. Moreover, at the same time, the bundle type pin locator 121 of the bundle type structure can complete the picking by forming a step around the inner plate 31 by the remaining hexagonal pin locator 1211b to prevent any detachment of the inner plate 31.

[0098] Therefore, the picking unit 120 according to the embodiment of the present invention can use the bundle pin positioner 121 to absorb the position error e occurring in each pallet, thereby maintaining the state in which the robot arm 10 can pick up the door panel.

[0099] Reference again Figures 1 to 3 The side clamping unit 130 limits the side point P3 of the inner panel 31 using a fixed positioner 131 and a clamper 132 operated by a clamping cylinder 133 .

[0100] The side clamping unit 130 clamps the inner surface of the side point P3 by the clamping cylinder 133 while placing the fixing positioner 131 on the outer surface of the side point P3, using the clamper 132 rotating around the hinge shaft 135. The reverse operation is that the side clamping unit 130 operates the clamping cylinder 133 backward to release the clamping of the side point P3.

[0101] The side gripper unit 130 according to the embodiment of the present invention includes a laser sensor 134 for measuring a distance deviation (ie, a distance difference) "D" between a reference position of the inner panel 31 set based on robot teaching and a changed position of the actually loaded inner panel 31.

[0102] at the same time, Figure 6 According to an embodiment of the present invention, Figure 2 0 is a cross-sectional view taken along line BB in FIG. 1 , and shows a state where the door panel cannot be clamped due to an error in the loading position of the door panel within the pallet.

[0103] refer to Figure 6 , the side clamping unit 130 moves to the reference position of the inner panel 31 set based on the robot hand teaching, and clamps the side point P3 of the inner panel 31 using the fixed positioner 131 and the clamper 132. The reference position refers to a position set to have a reference distance D1 from the inner panel 31 based on the robot hand teaching.

[0104] However, when the loading position of the door 30 is changed due to the position error of the partition in the tray 20, the deformation in the left-right direction (x-axis) is small, but the deformation in the front-back direction (y-axis) is relatively large, which may cause a situation where clamping is impossible. Therefore, when picking up the inner panel 31, it is necessary to compensate for the distance deviation between the side clamping unit 130 and the inner panel 31 by changing the position in the front-back direction (y-axis).

[0105] therefore, Figure 7 A solution to the change in the loading position of door panels in a pallet according to an embodiment of the present invention is shown.

[0106] refer to Figure 7 (A) According to an embodiment of the present invention, before clamping the inner panel 31, the side clamping unit 130 can use the laser sensor 134 to measure the distance deviation D between the reference position of the inner panel 31 set based on the robot hand teaching and the changed position of the actually loaded inner panel 31.

[0107] For example, according to an embodiment, the laser sensor 134 may include a calculation function for calculating a distance deviation D obtained by subtracting a reference distance D1 from a measured distance D2 measured before clamping. In addition, according to an embodiment, the laser sensor 134 may transmit the measured distance D2 measured before clamping to the control unit 150 to derive the distance deviation D obtained by subtracting the reference distance D1 from the measured distance D2.

[0108] Accordingly, refer to Figure 7 (B) The control unit 150 for controlling the robot hand 10 adjusts the moving distance of the robot hand 10 based on the distance deviation (eg, distance difference) “D” so that the side gripping unit 130 can pick up the inner panel 31 whose position has been changed.

[0109] In other words, by correcting the moving distance of the robot 10 , the side clamping unit 130 is placed at a reference distance D1 from the inner plate 31 at the changed position, so that the side point P3 of the inner plate 31 can be clamped by the fixed positioner 131 and the clamper 132 .

[0110] at the same time, Figure 8 Showing the height differences of the inner panel shapes of various types of doors according to an embodiment of the present invention.

[0111] refer to Figure 8 The heights of the inner plate shapes of the doors of various models to which the door installation process according to the embodiment of the present invention is applicable (i.e., the restricted cross-sectional heights) may be different from each other, for example, the door 30a of model A is 460 mm, the door 30b of model B is 499 mm, the door 30c of model C is 484 mm, etc. Therefore, in order for the robot 10 to pick up doors of various models, the picking unit 120 must be moved in the up-down direction (z-axis).

[0112] In this regard, the prior art proposes a clamp for a door using upper and lower clamps movably installed through an electric cylinder and a guide rail, but there are disadvantages of increased weight and a problem of long troubleshooting time.

[0113] In this regard, the present invention does not use an electric cylinder and a guide rail, but uses a pressure control valve 140 to adjust the pressure of the guide cylinder 122 of the pickup unit 120 in stages, and through force control, the bundle type pin locator 121 is slowly operated up and down. Here, force control refers to the degree to which the bundle type pin locator 121 pressurizes the control point of the inner plate 31.

[0114] Fig. 9 A control method of a pickup unit corresponding to doors of multiple models with limited cross-sectional height differences according to an embodiment of the present invention is shown.

[0115] Fig. 9 1 and 2 . The figure shows a process in which the pressure control valve 140 limits the upper point P1 and the lower point P2 of the inner panel through step-by-step pressure adjustment when the pickup unit 120 according to the embodiment of the present invention is aligned with the pickup position of the door 30 of multiple vehicle models.

[0116] The pressure control valve 140 includes an upper pressure control valve 140-1 and a lower pressure control valve 140-2 configured to correspond to the upper pickup unit 120-1 and the lower pickup unit 120-2, respectively. The upper pressure control valve 140-1 and the lower pressure control valve 140-2 operate in the same manner. Therefore, hereinafter, the operation of the upper pressure control valve 140-1 is mainly described, but the lower pressure control valve 140-2 may also operate in the same manner.

[0117] For example, in the initial operation step, during the initial operation of the upper pickup unit 120-1, the upper pressure control valve 140-1 sets the pressure of the pilot cylinder 122 to a small force of a low pressure to prevent damage to the inner panel 31. For example, the low pressure may be lower than a set pressure, and the set pressure may be a critical pressure that causes damage to the inner panel 31. Such a set pressure may be changed according to specifications such as the material and thickness of the door of the vehicle body 50, and it should be understood that those skilled in the art may obviously set the set pressure.

[0118] In the inner plate contact step of the bundle type pin locator, the upper pressure control valve 140 - 1 maintains a low pressure until a descending sensing signal of a portion of the hexagonal pin locator 1211 contacting the inner plate 31 is received through the laser beam sensor 1218 .

[0119] In addition, in the upper / lower unit plate limiting step, when receiving a descending sensing signal from the hexagonal pin locator 1211 of the laser beam sensor 1218, the upper pressure control valve 140-1 can strengthen the limiting force of the inner plate 31 by increasing the pressure of the guide cylinder 122 by a certain amount (for example, 6 bar).

[0120] In other words, when the upper pickup unit 120-1 rises, the upper pressure control valve 140-1 can lift the inner panel 31 with a smaller force to prevent damage to the inner panel 31, and after being located within the range where the inner panel 31 will not be damaged by the bundle pin locator 121, the pressing force is changed to a force for operating the door 30.

[0121] In the same manner as described above, the upper pick-up unit 120 - 1 and the lower pick-up unit 120 - 2 may collectively restrain the multi-model door 30 within the stroke range of the guide cylinder 122 regardless of the difference in the height of the inner panel shape.

[0122] Meanwhile, the control unit 150 controls overall operations of the robot hand 10 provided in the door installation process and the jig 100 mounted on the robot hand 10 .

[0123] After completing the clamping of the side point P3 by using the side clamping unit 130 , the control unit 150 may control each of the upper point P1 and the lower point P2 to be restricted by using the picking unit 120 .

[0124] The control unit 150 may include a robot controller 151 and a gripper controller 152 that are linked to each other.

[0125] The robot controller 151 moves the gripper 100 to a picking position of the door 30 loaded on the tray 20 through motion control of the robot 10 .

[0126] When the jig 100 is moved to the pick-up position, the robot controller 151 can measure the measured distance D2 from the inner plate 31 through the laser sensor 134, and derive the distance deviation D between the reference distance D1 of the inner plate 31 set based on the robot teaching and the measured distance D2. In addition, the robot controller 151 can correct the position of the jig 100 through the distance deviation D.

[0127] The clamp controller 152 may respectively control the operations of the picking unit 120 and the side clamping unit 130 of the clamp 100 moved to the picking position of the door 30 to limit the upper point P1, the lower point P2, and the side point P3 corresponding to the inner panel 31 of the door.

[0128] At this time, the clamp controller 152 controls the pressurization of the bundle pin positioner 121 configured at the front end of the pickup unit 120 step by step through the pressure control valve 140 , thereby performing corresponding restrictions on the change of the position and / or shape of the inner panel 31 .

[0129] The control unit 150 may be implemented as one or more processors operating according to a setting program, and the setting program may be programmed to perform various steps of the control method of the clamp for a door according to an embodiment of the present invention.

[0130] Hereinafter, a control method of a clamp for a door will be described in more detail with reference to the accompanying drawings.

[0131] Fig.10 and Fig.11 is a flowchart schematically illustrating a control method of a clamp for a door according to an embodiment of the present invention.

[0132] First, refer to Fig.10 , the control unit 150 of the clamp 100 for the door 30 installed on the robot 10 according to the embodiment of the present invention moves the clamp 100 to the set picking position of the door 30 through the motion control of the robot 10 (S10). The picking position may be a position for measuring whether the loading position of the door 30 in the tray 20 is changed before picking.

[0133] The control unit 150 measures the measured distance D2 from the inner panel 31 using the laser sensor 134 mounted on the side clamping unit 130 of the jig 100 ( S20 ).

[0134] The control unit 150 derives a distance deviation (ie, distance difference) “D” obtained by subtracting a reference distance D1 set based on robot hand teaching from the measured distance D2 ( S30 ).

[0135] The control unit 150 compares the distance deviation D with the clamping operation allowable value (for example, ±2 mm) of the side clamping unit 130 ( S40 ).

[0136] At this time, if the distance deviation D exceeds the allowable value (S40; yes), the control unit 150 corrects the position of the clamp 100 in the front-to-back direction (y-axis) (i.e., the position of the side clamping unit 130) according to the distance deviation D (S50), and operates the side clamping unit 130 to limit (clamp) the side point P3 of the inner panel 31 (S60).

[0137] On the other hand, if the distance deviation D does not exceed the allowable value ( S40 ; No), the control unit 150 operates the side clamping unit 130 to restrict the side point P3 of the inner panel 31 without performing position correction of the clamp 100 ( S60 ).

[0138] According to the control method of the clamp 100 for the door 30 of the present invention as described above, even if the loading position of the door 30 in the tray 20 is changed, the side clamping unit 130 can be clamped by distance correction. In addition, by clamping the side clamping unit 130, the picking unit 120 parallel to the front of the clamp 100 is placed in a pickable position.

[0139] Next, Fig.11 The flowchart shows that the control unit 150 applies pressure and restricts the upper point P1 and the lower point P2 of the inner panel 31 through the ascending or descending bundle type pin positioner 121 constructed in the pickup unit 120 of the jig 100 .

[0140] Specifically, in the initial operation step of the pickup unit 120, the control unit 150 controls each guide cylinder 122 to low pressure by setting the pressure control valve 140 to low pressure. At this time, each bundle type pin positioner 121 installed at the front end of the pickup unit 120 rises / falls with a small force (S70).

[0141] When the beam type pin locator 121 contacts the inner panel 31, the control unit 150 maintains low pressure control (S80) and monitors whether a portion of the hexagonal pin locator 1211a in contact with the inner panel 31 is lowered to the reference position through the laser beam sensor 1218 (S90).

[0142] At this time, if the control unit 150 does not receive the descending sensing signal of the hexagonal pin locator 1211 a of the above portion from the laser beam sensor 1218 ( S100 ; No), the control unit 150 waits while maintaining the above low pressure control.

[0143] On the other hand, if the control unit 150 receives a descent sensing signal of the hexagonal pin locator 1211a of the above-mentioned part from the laser beam sensor 1218 (S100; yes), the control unit 150 increases the pressure of the guide cylinder 122 by a certain amount (for example, 6 bar) to strengthen the restricting force of the inner plate 31 with increased force (S110).

[0144] At this time, the control unit 150 can use the pressing force of a part of the hexagonal pin locators 1211a in the beam-type pin locators 121 of the beam-type structure to fix the inner panel 31, and form a step around the inner panel 31 through the remaining hexagonal pin locators 1211b to complete the door panel picking up (S120) in an operable state.

[0145] As described above, according to the embodiment of the present invention, by providing a jig capable of performing robot position correction according to the position change of the door loaded on each pallet, it is possible to prevent the interruption of the assembly line in the smart factory and improve the operation rate.

[0146] In addition, by adopting the pick-up unit of the beam-type pin locator, a fixture capable of coping with inner panel position errors and shape height changes is provided, reducing the cost of pallet teaching management and enabling flexible manufacturing of multiple vehicles.

[0147] Furthermore, by using the lightweight clamp (eg, 55 kg) of the present invention instead of the conventional heavy-duty clamp (eg, 120 kg) using the electric cylinder and the guide rail, the load on the robot can be reduced and the energy usage rate can be reduced.

[0148] The embodiments of the present invention are not implemented only by the above-mentioned devices and / or methods, but can be implemented by a program for implementing the functions corresponding to the configuration of the embodiments of the present invention or a recording medium recording the program. According to the above description of the embodiments, professionals in the technical field to which the present invention belongs can easily implement such an implementation.

[0149] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improved forms by those skilled in the art using the basic concept of the present invention as defined in the appended claims are also within the scope of the present invention.

Claims

1. A fixture mounted on a robot arm for picking up doors loaded on a pallet, the fixture include: a frame mounted on the tool changing device of the robot; a pick-up unit installed at the front side of the frame and configured to apply pressure to each of an upper point and a lower point of the opening formed in the inner panel of the door and restrict each of the upper point and the lower point through a tie pin positioner; a pressure control valve configured to adjust the pressure applied to each pilot cylinder of the pickup unit; a side clamping unit mounted on the front side of the frame and configured to hold a side point position of the opening using a fixed positioner and a clamper operated under the driving force of a clamping cylinder; as well as A control unit is configured to adjust a moving distance of the robot hand by measuring a distance difference between the side gripping unit and the inner plate.

2. The clamp according to claim 1, in, The framework includes: a first vertical frame mounted on the front side, on which the pickup unit is mounted; and A second vertical frame is arranged in parallel with the first vertical frame, and the side clamping unit is mounted on the second vertical frame.

3. The clamp according to claim 1, in, The pickup unit comprises: an upper pick-up unit configured to restrict the upper point position of the inner panel by transmitting a force in an upward direction by the pressure of the guide cylinder through the tie pin positioner; and A lower pick-up unit is configured to restrict the lower point of the inner panel by transmitting a force in a downward direction using a pressure of the guide cylinder through the pin positioner.

4. The clamp according to claim 3, in, The pin locator comprises: a plurality of hexagonal pin locators constructed in a bundle-type structure at a location in contact with the inner panel; a support rod configured to extend from lower portions of the plurality of hexagonal pin locators in a longitudinal direction and configured to penetrate a horizontal plate formed in the housing; a spring mounted around the support rod and configured to support lower portions of the plurality of hexagonal pin locators; a fixing plate mounted on the lowermost end of the support rod and fixed on the lower surface of the horizontal plate; and A laser beam sensor is installed at a lower portion of the housing in a horizontal direction and is configured to sense descending positions of the plurality of hexagonal pin locators in contact with the inner panel.

5. The clamp according to claim 4, in, Each of the plurality of hexagonal pin locators is a pin having a regular hexagonal cross-sectional shape, and the plurality of hexagonal pin locators form a honeycomb pattern-like anti-slip pattern on an upper surface thereof contacting the inner panel.

6. The clamp according to claim 5, in: The plurality of hexagonal pin locators are closely arranged, and adjacent regular hexagonal sections face each other, and Each of the plurality of hexagonal pin positioners is configured to move up and down by the weight of the inner panel in contact with an upper surface thereof and an elastic force of the spring for supporting a lower portion of the inner panel.

7. The clamp according to claim 4, in: The laser beam sensor includes a light emitting unit and a light receiving unit, and The laser beam sensor is configured to sense that the lowered position of the fixing plate reaches a reference position using a laser beam transmitted from the light emitting unit and received by the light receiving unit, and is also configured to transmit a lowering sensing signal to the pressure control valve.

8. The clamp according to claim 7, in: The pressure control valve includes an upper pressure control valve and a lower pressure control valve respectively configured to correspond to the upper pickup unit and the lower pickup unit, and During initial operations of the upper pick-up unit and the lower pick-up unit, the upper pressure control valve and the lower pressure control valve set the pressure of the guide cylinder to a low pressure lower than a critical pressure to prevent damage to the inner panel.

9. The clamp according to claim 8, in: The upper pressure control valve and the lower pressure control valve maintain a low pressure below a critical pressure until the descent sensing signal from the laser beam sensor is received, and When receiving the descent sensing signal, the upper pressure control valve and the lower pressure control valve increase the pressure of the pilot cylinder by a certain amount to strengthen the restraining force on the inner panel.

10. The clamp according to claim 1, in, The side clamping unit is configured to hold the inner surface of the side point with the clamper rotating about the hinge axis through the advancing operation of the clamping cylinder while the fixing retainer is placed on the outer surface of the side point.

11. The clamp according to claim 1, in, The control unit is configured to control the upper point and the lower point by using the picking unit after the side clamping unit completes clamping the side point.

12. The clamp according to claim 1, in, The control unit comprises: a robot controller configured to measure a measured distance from the inner plate by a laser sensor and derive a distance difference between the measured distance and a reference distance set based on a robot teaching; and A clamp controller is configured to be linked with the robot controller and control the operations of the picking unit and the side clamping unit.

13. The clamp according to claim 12, in, The clamp controller is configured to control the pressing force of the pin positioner formed at the front end of the pickup unit step by step through the pressure control valve.

14. A control method for a fixture mounted on a robot arm for picking up doors loaded on a pallet, the control method The following steps are involved: By controlling the motion of the robot arm, the fixture is moved to a set picking position of the door; adjusting the moving distance of the robot hand by measuring the distance difference between the side clamping unit and the inner plate using a laser sensor installed on the side clamping unit of the clamp; Using the side clamping unit to maintain the side point position of the inner plate; as well as Pressure is applied to and restricted at upper and lower points of the inner panel by pin positioners formed in a pickup unit of the jig.

15. The control method according to claim 14, in, The step of adjusting the moving distance of the robot arm comprises: measuring the measured distance from the inner panel using the laser sensor; and The distance difference is derived by subtracting a reference distance based on a robot hand teaching setting from the measured distance.

16. The control method according to claim 14, in, The step of adjusting the moving distance of the robot arm comprises: comparing the distance difference with an allowable value for a clamping operation of the side clamping unit; and When the distance difference exceeds the allowable value, the position of the clamp in the front-rear direction is adjusted based on the distance difference.

17. The control method according to claim 14, in, The steps of limiting the upper point and the lower point include: In the initial operation step of the pickup unit, each pilot cylinder is controlled to a low pressure by setting a pressure control valve; maintaining the low pressure while the hexagonal pin locator is in contact with the inner panel, and monitoring by a laser beam sensor whether a portion of the hexagonal pin locator in contact with the inner panel reaches a reference position; and When a descending sensing signal of a portion of the hexagonal pin locators is received from the laser beam sensor, the restraining force on the inner panel is strengthened with an increased force by increasing the pressure of the guide cylinder by a certain amount.

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