Centering and locking mechanism

Abstract

The invention discloses a centering and locking mechanism, and belongs to the field of machinery. Comprising two pick-up arms on a turnover box or turnover box group pick-up device; the lower ends of the two pick-up arms are provided with end effectors with hook heads; the end effector comprises a centering locking device located on the inner side of the hook head. The centering locking device comprises a vertical piston sleeved with a reset spring and two transverse pistons. The vertical piston is of a T-shaped structure and is arranged on the inner side of the hook head in an up-down moving mode. The reset spring is sleeved on the vertical edge of the T-shaped structure; the two transverse pistons are arranged on the two sides of the bottom end of the vertical piston in a transverse sliding mode respectively. The bottom end of the vertical piston is respectively connected with the tail ends of the two transverse pistons through two connecting strips; the head ends of the two connecting strips are in pin joint with the bottom end of the vertical piston to form a first pin joint point; the tail ends of the two connecting strips are in pin joint with the tail ends of the two transverse pistons respectively to form second pin joint points. And it can be ensured that the end effector can automatically position the center of the sunken handle of the turnover box.

Description

Technical Field

[0001] The present invention belongs to the field of cargo loading machinery, and in particular relates to a device and a method for allowing an end effector to safely grasp the center of a recessed handle of a turnover box. Background Art

[0002] The measurement center is a place that provides automated calibration lines and intelligent warehousing for all subordinate units of the State Grid.

[0003] Validated meters and transformers are placed in dedicated tote boxes of special dimensions, which are stacked and placed on a powered conveyor leading to the loading area.

[0004] Currently, the core operation of the metering center, namely the verification of electricity meters and transformers, is fully automated; verified electricity meters and transformers are placed in customized tote boxes and sent to the loading area via a motorized conveyor belt.

[0005] Once the crates reach the end of the conveyor, they are manually stacked 12 high, moved into truck containers and placed in their destination. A critical task in this process is correctly stacking the crates.

[0006] like Figure 1a and Figure 1b As shown in the figure, the turnover box is made of hard plastic, and the center of the top of both sides of the turnover box (see Figure 1a There are two recessed handles 2 in the portion framed by the black line segment, and two longitudinal inner side walls 18 are arranged on both sides of the recessed handles.

[0007] The top bevel edge 1 of each recessed handle extends 5mm outward from the end of the turnover box, forming an extended top bevel edge 3, which allows a person's fingers to bend, insert and hook, so as to lift the turnover box; the lower edge of the top bevel edge is about 5mm away from the outer wall of the turnover box, forming the extended width 5 of the top bevel edge; there is a longitudinal space 4 along the bottom below the top bevel edge, and there are no other obstacles in this longitudinal space along the bottom (the longitudinal height is about 63mm). The bottom protrusion 20 is designed on the turnover box to prevent the turnover boxes from moving when overlapping each other, which is conducive to maintaining the stability of each stack.

[0008] In terms of handling and stacking turnover boxes, various automated devices have been widely used to reduce the labor intensity of manual operations.

[0009] The invention patent with the authorization announcement date of 2014.12.03 and the authorization announcement number of CN 102662156 B discloses "a kind of electric energy meter turnover box clamping mechanism", which includes a first arm, a second arm and an arm tail rod connecting the same side ends of the two arms, and at least one of the first arm and the second arm is provided with a clamping device for clamping the electric energy meter turnover box. The technical solution is provided with the first arm, the second arm and the arm tail rod connecting the same side ends of the two arms, so that they enclose a space for accommodating the turnover box, and then through the clamping action of the clamping device, the turnover box is clamped by the electric energy meter turnover box clamping mechanism to complete the clamping operation of a single turnover box; when the turnover box needs to be placed, the turnover box and the electric energy meter turnover box clamping mechanism are relatively separated through the contraction action of the clamping device to complete the placement operation of the turnover box. Through the electric energy meter turnover box clamping mechanism, the clamping and placement functions of a single electric energy meter turnover box are realized. However, this technical solution focuses on the horizontal clamping of a single electricity meter turnover box, and can only be applied to the picking and placing operation scenarios of a single electricity meter turnover box, but cannot be applied to the clamping and moving scenarios of multiple electricity meter turnover boxes (also called electricity meter turnover box groups) that have been stacked vertically.

[0010] The utility model patent with the authorization announcement date of 2014.09.24 and the authorization announcement number of CN 203845469 U discloses a "paper turnover box stacking and unstacking device for the automatic calibration system of electric energy meters", which includes a horizontal transfer mechanism, a lifting device and a rotatable clamping mechanism. The horizontal transfer mechanism is horizontally installed on the frame, and the lifting device is vertically connected to the execution end of the horizontal transfer mechanism through its mounting support; the rotatable clamping mechanism is composed of a rotating cylinder, a gripper mechanism mounting plate and multiple gripper mechanisms, and the rotating cylinder is installed at the lower end of the lifting device; the gripper mechanism mounting plate is set at the rotating shaft end of the rotating cylinder, and multiple gripper mechanisms are dispersedly arranged below the gripper mechanism mounting plate. This technical solution can make two layers of turnover boxes adjacent to each other form a certain angle for unstacking and stacking, and can ensure the safety and reliability of the placement of paper incoming boxes and their meters on the assembly line. However, it does not have the function of grabbing, clamping and moving a whole group of turnover boxes (also called a turnover box stack) composed of multiple turnover boxes stacked longitudinally.

[0011] How to safely and stably grasp, clamp and move a whole group of turnover boxes consisting of multiple turnover boxes stacked vertically is a technical problem that needs to be solved in practical work.

[0012] The utility model patent with the authorization announcement date of 2020.07.28 and the authorization announcement number of CN 211109843 U discloses "a turnover box gripper for a palletizing robot", including a fixed seat and a gripper mechanism, sliding plates are provided on both sides of the fixed seat, the sliding plates can move toward or away from the fixed seat, the gripper mechanism is arranged on the sliding plate, the gripper mechanism includes a rotating gripper and a limit rod, each sliding plate is provided with a rotating gripper and a limit rod, the rotating gripper can be rotatably arranged on the sliding plate, the limit rod is fixedly arranged on the sliding plate, the rotating gripper is arranged in a "V" shape, the gripper mechanism is also provided with a tension spring for resetting the rotating gripper, and a driving mechanism for driving the two sliding plates to move toward or away from each other is provided on the fixed seat. This technical solution provides a turnover box gripper for a palletizing robot, which can quickly and stably grasp, so that the turnover box can ensure its high efficiency and maintain stability during palletizing. However, this technical solution still uses mechanical parts to "clamp" to achieve the clamping function of a single turnover box (see Figure 5 of the specification), and is not suitable for use scenarios in which a whole group of turnover boxes consisting of multiple turnover boxes stacked longitudinally is grasped, clamped and moved. Summary of the invention

[0013] The technical problem to be solved by the present invention is to provide a centering and locking mechanism. By arranging an end effector at the end of two picking arms of a picking device, with the help of a set of centering and locking mechanisms, the end effector can be conveniently lifted or lowered through a vertical piston and a set of return springs to realize the lateral extension or contraction of two lateral pistons, thereby realizing the functions of automatic centering, automatic positioning, stable clamping, and automatic release in place at the end of the picking arm, ensuring that the end effector can automatically locate the center of the recessed handle of the turnover box and can firmly grasp the recessed handle of the turnover box.

[0014] The technical solution of the present invention is to provide a centering and locking mechanism, including two picking arms arranged on a pickup device for a turnover box or a turnover box group, characterized in that:

[0015] At the lower end of the two picking arms, an end effector with a hook head is respectively provided, which is used to extend into the recessed handle of the bottom turnover box; the end effector includes a centering locking device located inside the hook head; the centering locking device includes a vertical piston with a return spring and two transverse pistons;

[0016] The vertical piston is a T-shaped structure, which can be moved up and down and arranged on the inner side of the hook head; its return spring is sleeved on the vertical side of the T-shaped structure; two transverse pistons can be slid transversely and are respectively arranged on both sides of the bottom end of the vertical piston; the bottom end of the vertical piston is connected to the tail ends of the two transverse pistons through two connecting strips; the head ends of the two connecting strips are pin-connected with the bottom end of the vertical piston to form a first pin connection point; the tail ends of the two connecting strips are pin-connected with the tail ends of the two transverse pistons to form a second pin connection point;

[0017] When it is necessary to pick up a turnover box or a turnover box group, the picking arm drives the end effector to enter the recessed handle and move upward, the top of the vertical piston moves downward under the downward pressure of the recessed handle, the first pin contact point drops, and the two lateral pistons are pushed outward / extended through the two connecting strips, thereby realizing the automatic centering and automatic clamping functions of the end effector;

[0018] When it is necessary to release the turnover box or the turnover box group, the picking arm descends, and under the action of the return spring, the vertical piston moves upward, the first pin contact point rises, driving the two lateral pistons to shrink / retract inward, and the end effector disengages from the recessed handle, realizing the automatic release function of the end effector in place.

[0019] Specifically, the two transverse pistons are symmetrically arranged on both sides of the vertical piston, with the vertical side of the T-shaped structure of the vertical piston as the axis.

[0020] Furthermore, the two transverse pistons are coaxially arranged, with the vertical side center line of the vertical piston T-shaped structure as the symmetry axis, and are transversely symmetrically arranged on both sides of the bottom end of the vertical side of the vertical piston.

[0021] Specifically, the longitudinal position of the first pin connection point is higher than the longitudinal position of the second pin connection point.

[0022] Once both lateral pistons contact the two inner walls of the recessed handle, the end effector will stop advancing upward in the recessed handle.

[0023] If one of the two transverse pistons first contacts the inner side wall of the corresponding recessed handle of the turnover box, the end effector will continue to move upward so that the other transverse piston can also reach the inner side wall of the corresponding recessed handle of the turnover box, thereby ensuring that the outer center of the end effector coincides with the center of the recessed handle.

[0024] Furthermore, the centering and locking mechanism works according to the following steps:

[0025] 1) The end effector enters the space below the recessed handle;

[0026] 2) The end effector moves upward until the bottom edge of the inclined top edge of the recessed handle contacts the top of the vertical piston of the centering locking device;

[0027] 3) As the end effector continues to move upward, the vertical piston of the centering locking device is pressed down by the bottom edge of the inclined top edge, and the downward movement of the vertical piston of the centering locking device is converted into a lateral force, pushing the two lateral pistons on both sides of the end effector outward;

[0028] 4) If only one transverse piston contacts its corresponding inner side wall, the end effector will continue to move upward until both transverse pistons contact their inner side walls and the longitudinal centerline of the end effector coincides with the longitudinal centerline of the recessed handle or turnover box;

[0029] 5) The lateral pressure of the lateral piston on the inner wall locks the end effector to the tote, allowing the tote to be safely picked up and placed in place;

[0030] 6) Once the crate is in place, the end effector is lowered so that it can be removed from the recessed handle, during which the vertical piston of the centering lock returns to its original position.

[0031] Specifically, the centering and locking mechanism utilizes the lifting or lowering of the end effector to achieve the lateral extension or retraction of the two lateral pistons, thereby realizing functions such as automatic centering, automatic positioning, firm clamping, and automatic release in place at the end of the picking arm, ensuring that the end effector can automatically locate the center position of the recessed handle of the turnover box and can firmly grasp the recessed handle of the turnover box.

[0032] Furthermore, the bottom end of the vertical piston is connected to the tail ends of the two transverse pistons through two connecting strips, converting the vertical downward force on the vertical piston into a lateral thrust that can push the two transverse pistons outward; and converting the vertical upward force on the vertical piston into a lateral pulling force that can retract the two transverse pistons inward.

[0033] Furthermore, the lateral pressure or thrust of the two lateral pistons on the inner wall of the turnover box prevents the centering locking device from sliding along the recessed handle, thereby locking the end effector to the center position of the recessed handle of the turnover box.

[0034] Compared with the prior art, the advantages of the present invention are:

[0035] 1. The technical solution adopted by the present invention realizes the automatic positioning of the inner curved hook of the end effector in the recessed handle by configuring the end effector at the ends of the two picking arms of the picking device and using a set of centering and locking mechanisms, thereby ensuring the accurate positioning of the center of the recessed handle of the turnover box and being able to stably grasp the turnover box, so that the automatic stacking system can stably pick up the turnover box and accurately place it at the target position;

[0036] 2. The technical solution adopted by the present invention, through the vertical piston and the matching return spring, can conveniently drive the lateral extension and retraction of the two lateral pistons by means of the lifting and lowering operation of the end effector, so as to realize the functions of automatic centering, stable clamping, normal movement, automatic release in place, etc. of the end of the picking arm;

[0037] 3. The technical solution adopted by the present invention realizes the automatic centering, grasping, clamping and moving functions of a single turnover box or a whole group of turnover boxes (also called turnover box stacks) by correspondingly configuring end effectors at the ends of the two picking arms of the picking device. It solves the problems of automatic centering, firm clamping and automatic release of the ends of the two picking arms in the usage scenarios of grasping, clamping and moving the whole group of turnover boxes, and ensures that the function of the end effector being able to stably grasp the center of the recessed handle of the turnover box can be smoothly realized during the working process. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1a It is a schematic diagram of the appearance structure of the turnover box and the recessed handle;

[0039] Figure 1b It is a schematic diagram of the cross-sectional structure of the turnover box and the recessed handle;

[0040] Figure 2 It is a schematic diagram of stacked multi-layer turnover boxes, end effectors, and end effector control joints;

[0041] Figure 3 It is a schematic diagram of the effect of the tolerance of the control joint on the deviation of the end effector;

[0042] Figures 4a to 4c It is a structural schematic diagram of the centering and locking device of the present invention and its components;

[0043] Figure 5a and Figure 5b It is a schematic diagram of the state in which the centering and locking device of the present invention completes centering and locking;

[0044] Figures 6a to 6d It is a schematic diagram of the centering and locking process of the centering and locking device of the present invention;

[0045] Figure 7a and Figure 7b is a schematic diagram of the centering locking device of the present invention being released from the recessed handle;

[0046] Figure 8 It is a flow chart of the centering and locking device and the end effector of the present invention on the recessed handle.

[0047] In the figure, 0 is a strip platform, 1 is an inclined top edge, 2 is a recessed handle, 2a is the center of the recessed handle, 3 is an inclined top edge, 4 is a spatial longitudinal direction, 5 is an extended width of the recessed handle, 6 is a turnover box stack, 7 is a distance from the end effector to its control joint, 8 is an end effector, 8a is an outer center of the end effector, 9 is a control joint, 10 is a deviation caused by a tolerance at the control joint, 11 is a deviation at the end effector, 12 is a centering locking device, 13 is an upward movement distance of the end effector, 14 is a vertical piston, 15 is a return spring, 16 is a transverse piston, 17 is a connecting strip, 18 is an inner wall, 19 is an inner top of the recessed handle, and 20 is a top of a hook head. DETAILED DESCRIPTION

[0048] The present invention will be further described below in conjunction with the accompanying drawings.

[0049] As mentioned above, for the stacking process of the aforementioned turnover boxes, the existing automatic stacking system can successfully implement the automatic clamping and movement of a single turnover box.

[0050] However, the existing automatic stacking system cannot ensure smooth grabbing and moving of a group of turnover boxes (also called a turnover box stack) after multiple turnover boxes have been stacked and placed together.

[0051] Automatic palletizing systems require the use of spatial guidance systems available on the market, which can be customized for use. However, all these guidance systems assume that the connection between the pick and place mechanism (customarily called the end effector) and the object to be picked and placed is stable and strong, and aligned with specific reference points. This situation and goal is easy to achieve when the end effector grasps the outside of ordinary objects, but it is not easy to achieve for the structure of the tote box; because the structure of the tote box determines that it has only two recessed handles for the end effector to grasp.

[0052] Therefore, the technical problem that needs to be solved is: how to make the end effector smoothly enter the recessed handle, tighten its grip, and make the longitudinal center line of the end effector coincide with the longitudinal center line of the turnover box. In other words, how to make the end effector automatically position itself at the center of the recessed handle and firmly grasp the recessed handle.

[0053] The technical solution of the present invention provides a device and method that enables an end effector to automatically locate the center of a recessed handle of a turnover box and to firmly grasp the recessed handle of the turnover box, so that an automatic stacking system can firmly pick up the turnover box and place it at a target position, that is: a centering and locking device that can automatically locate the center of a recessed handle of a turnover box and to firmly grasp the recessed handle of the turnover box.

[0054] In the prior art, the picking device of the automatic stacking system for picking up the turnover box group, such as Figure 2 As shown in the figure, two picking arms are rotatably arranged on the strip platform 0 of the picking device. The two picking arms are symmetrically arranged at both ends of the strip platform. The picking arms are pinned and fixed to the strip platform through control joints so that the picking arms can swing within a certain limit relative to the strip platform to achieve the functions of inward clamping and outward disengagement.

[0055] At the lower end of the two picking arms, an end effector 8 with a curved hook is respectively provided for extending into the recessed handle of the bottommost turnover box.

[0056] Wherein, the end effector is arranged on the inner side of the curved hook head.

[0057] exist Figure 2 In the figure, the height 7 from the end effector 8 to its control joint 9 (i.e., the longitudinal length of the picking arm) depends on the height of the maximum turnover box stack (i.e., the aforementioned turnover box group) that needs to be processed, i.e., the turnover box stack 6 formed by stacking 5 turnover boxes.

[0058] The recessed handle is very efficient ergonomically and spatially, but it is a challenge for the robotic end effectors because both end effectors need to be small enough to enter the recessed handle, align with the center, and be able to securely move the tote without slipping.

[0059] In order to be reliably placed and hooked into the recessed handle, there needs to be at least a 10 mm gap between the side of the end effector and the inner side wall of the recessed handle. In other words, the end effector 8 needs to be 20 mm narrower than the extended width 5 of the recessed handle.

[0060] Depend on Figure 2 As shown in FIG. , the distance 7 from the end effector 8 to its control joint 9 is relatively long, which is 594 mm.

[0061] Small changes at the control joint will mean larger changes at the end effector.

[0062] exist Figure 3In the example, a deviation of 10 caused by a tolerance at the control joint will be converted into a deviation of 11 at the end effector; for example, a deviation of 0.5 mm caused by a tolerance of 0.5 mm at the control joint will be converted into a deviation of 5.3 mm at the end effector.

[0063] Once the end effector is inside the recessed handle and hooked onto the beveled top edge, it needs to be precisely aligned with the horizontal center of the tote (or recessed handle). This means there is a potential error of + / -5.3mm in the process of the end effector hooking onto the recessed handle, thus confirming that a tolerance of + / -10mm (20mm total) is required between the width of the end effector and the width of the recessed handle.

[0064] See also Figures 4a to 5a As shown in the technical solution of the present invention, the end actuator 8 includes a centering locking device 12 located on the inner side of the hook head; the centering locking device includes a vertical piston with a return spring and two transverse pistons; wherein the vertical piston is a T-shaped structure, which can be movably arranged on the inner side of the hook head up and down; its return spring is mounted on the vertical side of the T-shaped structure; the two transverse pistons can be slidably arranged on both sides of the bottom end of the vertical piston; the bottom end of the vertical piston is connected to the tail ends of the two transverse pistons through two connecting strips.

[0065] The two transverse pistons are symmetrically arranged on both sides of the vertical piston, taking the vertical side of the T-shaped structure of the vertical piston as an axis.

[0066] Furthermore, the two transverse pistons are coaxially arranged, with the vertical side center line of the vertical piston T-shaped structure as the symmetry axis, and are transversely symmetrically arranged on both sides of the bottom end of the vertical side of the vertical piston.

[0067] The head ends of the two connecting strips are pin-connected with the bottom end of the vertical piston to form a first pin connection point; the tail ends of the two connecting strips are pin-connected with the tail ends of the two transverse pistons to form a second pin connection point; the longitudinal position (height) of the first pin connection point is higher than the longitudinal position (height) of the second pin connection point.

[0068] When the top of the vertical piston (the horizontal side of the T-shaped structure) is pressed and moves downward, the first pin connection point drops, and pushes the two lateral pistons to move outward / extend through the two connecting strips; conversely, when the vertical piston moves upward under the action of the return spring, the first pin connection point rises, driving the two lateral pistons to contract / retract inward.

[0069] In the present technical solution, when it is necessary to pick up a turnover box or a turnover box group, the picking arm drives the end effector to enter the recessed handle and move upward, the top of the vertical piston moves downward under the downward pressure of the recessed handle, the first pin connection point drops, and the two lateral pistons are pushed outward / extended through two connecting strips, thereby realizing the automatic centering and automatic clamping functions of the end effector.

[0070] When it is necessary to release the turnover box or turnover box group, the picking arm descends, and under the action of the return spring, the vertical piston moves upward, the first pin contact point rises, driving the two lateral pistons to retract / retract inward, and the end effector disengages from the recessed handle, realizing the automatic disengagement function of the end effector.

[0071] like Figures 4a to 4c As shown in FIG. 1 , the centering locking device 12 of the present invention is an integral part of the end effector 8. When the end effector enters the recessed handle 2 and moves upward ( Figure 4b When the end effector moves upward (with 13 to mark the upward movement distance of the end effector), the bottom edge of the inclined top edge 1 will contact the top of the vertical piston 14 of the centering locking device.

[0072] When the end effector continues to move upward into the recessed handle, the vertical piston 14 of the centering locking device will be pressed down by the bottom edge of the inclined top edge (because the overall weight of the turnover box is much higher than the force required to move the vertical piston of the centering locking device downward and compress its return spring 15), and the bottom end of the vertical piston of the centering locking device is connected to the two transverse pistons 16 through two connecting strips 17 so as to convert the vertical downward force on the vertical piston into a lateral force capable of pushing the two transverse pistons outward.

[0073] exist Figure 5a and Figure 5b Once both transverse pistons 16 contact the two inner walls 18 of the recessed handle, the end effector 8 will stop moving upward in the recessed handle because the stroke length of the transverse piston does not allow the tip of the end effector (i.e., the top 20 of the hook head) to contact the inner top 19 of the recessed handle.

[0074] refer to Figures 6a to 6dAs shown in , if one of the two transverse pistons first contacts the inner wall 18 of the recessed handle of the corresponding turnover box, the end effector 8 will continue to move upward so that the other transverse piston can also reach the inner wall of the recessed handle of the corresponding turnover box, thereby ensuring that the outer center 8a of the end effector merges (i.e. coincides) with the center 2a of the recessed handle, which is also the outer center of the entire turnover box. In addition, the lateral pressure (thrust) of the two transverse pistons 16 on the inner wall 18 also fully prevents the centering locking device from sliding along the recessed handle (actually locking the end effector to the turnover box). The end effector and the turnover box are now firmly connected and aligned, allowing the turnover box or turnover box stack (turnaround box group) to be accurately lifted, moved and placed in its target position.

[0075] exist Figure 7a and Figure 7b In the process, once the container is placed in its target position, the end effector 8 will be lowered relative to the container. At this time, because there is no downward force on the bottom edge of the inclined top edge and the return spring 15 in the centering locking device is released, the vertical piston 14 will be allowed to return to its original position.

[0076] As the vertical piston is reset under the action of the reset spring, the first pin contact point at the lower end of the vertical side of the vertical piston rises, and through the action of the two connecting strips, the two horizontal pistons are driven to retract inwards. Figure 6c The status position shown returns to Figure 4c Status position shown.

[0077] exist Figure 8 The steps for the centering locking device to lock onto the recessed handle of the tote, center itself, and lock into place are listed:

[0078] 1) The end effector enters the space under the recessed handle, which is achieved by making the width of the end effector 20 mm narrower than the width of the recessed handle;

[0079] 2) The end effector moves upward until the bottom edge of the inclined top edge contacts the top of the vertical piston of the centering locking device;

[0080] 3) As the end effector continues to move upward, the vertical piston of the centering locking device will be pressed down by the bottom edge of the inclined top edge, and this downward movement of the vertical piston of the centering locking device will be converted into a lateral force, pushing the two lateral pistons on both sides of the end effector outward;

[0081] 4) If only one lateral piston contacts its corresponding inner wall (e.g. Figure 6a ), the end effector will continue to move upward until both lateral pistons touch the inner wall (as shown in Figure 6c), and the center of the end effector will merge with the center of the recessed handle (or turnover box);

[0082] 5) The lateral pressure of the lateral piston against the inner wall locks the end effector to the tote, allowing the tote to be safely picked up and placed in place;

[0083] 6) Once the tote is in place, the end effector is lowered so that it can be removed from the recessed handle (e.g. Figure 7a and Figure 7b ), during which the vertical piston of the center locking device returns to its original position.

[0084] The technical solution of the present invention is to configure an end effector at the end of the two picking arms of the picking device, and the end effector constitutes a set of centering and locking mechanisms. Through the vertical piston and the matching return spring in the mechanism, the lateral extension or contraction of the two lateral pistons can be conveniently achieved through the lifting and lowering action of the end effector. This mechanism further realizes the functions of automatic centering, stable clamping, normal movement and automatic release in place at the end of the picking arm. The inner curved hook of the end effector is located in the recessed handle, which can automatically locate and lock the center of the recessed handle of the turnover box, ensuring that the recessed handle of the turnover box can be firmly grasped. This enables the automatic stacking system to stably pick up the turnover box and accurately place it at the target position. The technical solution effectively solves the problems of automatic centering, stable clamping and automatic release in place at the end of the two picking arms when grabbing, clamping and moving a whole group of turnover boxes, ensuring that the end effector can stably grasp the center of the recessed handle of the turnover box during the working process, thereby smoothly realizing its functions.

[0085] The present invention can be widely applied to the design and manufacturing fields of automatic clamping devices for turnover boxes or turnover box groups and automatic stacking system equipment.

Claims

1. A centering and locking mechanism, comprising two picking arms provided on a picking device for a turnover box or a turnover box group, characterized in that: At the lower end of the two picking arms, an end effector with a curved hook is respectively provided, which is used to extend into the recessed handle of the bottom turnover box; The end effector comprises a centering and locking device located inside the hook head; The centering locking device comprises a vertical piston with a return spring and two transverse pistons; The vertical piston is a T-shaped structure and is movably arranged on the inner side of the hook head; Its return spring is sleeved on the vertical side of the T-shaped structure; Two transverse pistons are respectively arranged on both sides of the bottom end of the vertical piston in a transversely slidable manner; The bottom end of the vertical piston is connected to the tail ends of the two transverse pistons respectively through two connecting strips; The head ends of the two connecting strips are pin-connected with the bottom end of the vertical piston to form a first pin connection point; The ends of the two connecting strips are respectively pin-connected with the tail ends of the two transverse pistons to form a second pin connection point.

2. The centering and locking mechanism according to claim 1, characterized in that When it is necessary to pick up a turnover box or a turnover box group, the picking arm drives the end effector to enter the recessed handle and move upward, the top of the vertical piston moves downward under the downward pressure of the recessed handle, the first pin contact point drops, and the two lateral pistons are pushed outward / extended through the two connecting strips, thereby realizing the automatic centering and automatic clamping functions of the end effector; When it is necessary to release the turnover box or the turnover box group, the picking arm descends, and under the action of the return spring, the vertical piston moves upward, the first pin contact point rises, driving the two lateral pistons to shrink / retract inward, and the end effector disengages from the recessed handle, realizing the automatic release function of the end effector in place.

3. The centering and locking mechanism according to claim 1, characterized in that The two transverse pistons are symmetrically arranged on both sides of the vertical piston, with the vertical side of the T-shaped structure of the vertical piston as the axis; Furthermore, the two transverse pistons are coaxially arranged, with the vertical side center line of the vertical piston T-shaped structure as the symmetry axis, and are transversely symmetrically arranged on both sides of the bottom end of the vertical side of the vertical piston.

4. The centering and locking mechanism according to claim 1, characterized in that The longitudinal position of the first pin connection point is higher than the longitudinal position of the second pin connection point.

5. The centering and locking mechanism according to claim 1, characterized in that Once both lateral pistons contact the two inner walls of the recessed handle, the end effector will stop advancing upward in the recessed handle.

6. The centering and locking mechanism according to claim 5, characterized in that If one of the two transverse pistons first contacts the inner side wall of the corresponding recessed handle of the turnover box, the end effector will continue to move upward so that the other transverse piston can also reach the inner side wall of the corresponding recessed handle of the turnover box, thereby ensuring that the outer center of the end effector coincides with the center of the recessed handle.

7. The centering and locking mechanism according to claim 1, characterized in that The centering and locking mechanism works according to the following steps: 1) The end effector enters the space below the recessed handle; 2) The end effector moves upward until the bottom edge of the inclined top edge of the recessed handle contacts the top of the vertical piston of the centering locking device; 3) As the end effector continues to move upward, the vertical piston of the centering locking device is pressed down by the bottom edge of the inclined top edge, and the downward movement of the vertical piston of the centering locking device is converted into a lateral force, pushing the two lateral pistons on both sides of the end effector outward; 4) If only one transverse piston contacts its corresponding inner side wall, the end effector will continue to move upward until both transverse pistons contact their inner side walls and the longitudinal centerline of the end effector coincides with the longitudinal centerline of the recessed handle or turnover box; 5) The lateral pressure of the lateral piston on the inner wall locks the end effector to the tote, allowing the tote to be safely picked up and placed in place; 6) Once the crate is in place, the end effector is lowered so that it can be removed from the recessed handle, during which the vertical piston of the centering lock returns to its original position.

8. The centering and locking mechanism according to claim 1, characterized in that The centering and locking mechanism utilizes the lifting or lowering of the end effector to achieve the lateral extension or retraction of the two lateral pistons, thereby realizing the functions of automatic centering, automatic positioning, firm clamping, and automatic release in place at the end of the picking arm, ensuring that the end effector can automatically locate the center position of the recessed handle of the turnover box and can firmly grasp the recessed handle of the turnover box.

9. The centering and locking mechanism according to claim 1, characterized in that The bottom end of the vertical piston is connected to the tail ends of the two transverse pistons through two connecting strips, so as to convert the vertical downward force on the vertical piston into a lateral thrust that can push the two transverse pistons outward; The vertical upward force on the vertical piston is converted into a lateral pulling force that can retract the two transverse pistons inward.

10. The centering and locking mechanism according to claim 1, characterized in that The lateral pressure or thrust of the two lateral pistons on the inner wall of the turnover box prevents the centering locking device from sliding along the recessed handle, and locks the end effector to the center position of the recessed handle of the turnover box.

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