JP7689738B2 - Egg container loading system - Google Patents

Description

The present invention relates to a system for loading egg containers onto an egg container transport cart.

Transport racks are used to transport egg containers filled with eggs (also called "egg packs") to retail businesses such as supermarkets. Examples include a transport roll box made by Yoshida Elsys Co., Ltd. specifically for egg packs, and a roll rack made by San-ei Seisakusho Co., Ltd. Furthermore, Patent Document 1 describes a transport rack for transporting egg containers that contain eggs. The transport rack has multiple foldable shelves and is designed to be stored compactly in the depth direction.

Patent Document 2 describes a shelf opening device that can automatically open a folding shelf (return the folded state to the original state (shelf state)). In Figure 2A, egg containers are placed vertically at the back of the shelf.

Patent document 3 discloses that the tip (21) and gripper (11) of the robot arm (2) are positioned at a position offset from the center of gravity of the egg container in the longitudinal direction, particularly away from the folding shelves to avoid contact with the folding shelves, while adsorbing and transporting the egg container, and placing the egg container upright at the back of the shelf.

FIGS. 2 and 3 of Patent Document 4 disclose a configuration in which an egg container is adsorbed by an adsorbing member (4) that is a part of a holding portion (3).
Like Patent Document 4, Patent Document 5 discloses a configuration in which egg packs are adsorbed and transported using some of the adsorption members, and discloses that egg packs stacked on top of the first layer of egg packs on a shelf are positioned so that they protrude into the space above the front or rear frame.

Utility Model Registration No. 3209255 Patent No. 6684511 Patent No. 6807091 JP 2021-187489 A JP 2022-1397 A

In each of the above Patent Documents 3, 4 and 5, in order to prevent the hand tip of the robot arm and the suction means from interfering with (colliding with) the folding plates, the suction position is shifted from the longitudinal center of gravity of the egg container.
However, this is very unstable compared to suction at the center of gravity, and there is a risk of the egg container falling, particularly during suction and transport at high speed.
Furthermore, in the embodiments of Patent Documents 3, 4 and 5, the top surface is all flat-packed, and although the specifications state that they can also be applied to regular packs whose top surface has a shape that matches the outer appearance of an egg, regular packs have inferior suction stability compared to flat packs, and therefore high-speed transportation is difficult when suction is shifted from the center of gravity position as in Patent Documents 3, 4 and 5.

The present invention aims to provide an egg container loading system that can transport a wide variety of egg containers at high speed while avoiding collisions with egg container transport vehicles and egg containers below.

The first egg container loading system (A1) comprises:
A robot arm (10);
a gripping portion (31) provided on a hand (11) at the tip of the robot arm (10);
a plurality of suction members (32) provided on the gripping portion (31) for suctioning one or a plurality of egg containers (P);
a loading operation control unit (70) for controlling the robot arm (10) and the gripping unit (31) in accordance with a predetermined loading pattern;
The loading operation control unit (70)
(1) gripping central regions of the one or more egg containers (P) at a waiting position (W) with the gripping portion (31) (so that the central regions of the one or more egg containers (P) and the central region of the gripping portion (31) overlap with each other), transporting the one or more egg containers (P) toward an unfolded folding shelf of an egg container transport cart (8), and controlling a loading operation of loading the one or more egg containers (P);
(2) In the loading operation, the folding shelf boards are controlled to be vertically arranged along the front-rear direction of the folding shelf boards and horizontally arranged along the left-right direction perpendicular to the front-rear direction in accordance with a loading pattern.
(3) controlling a collision avoidance operation of operating the robot arm (10) so as to avoid collision between the folding shelf (852) in the folded state, the front retaining portion (8521) protruding forward of the folding shelf (852) in the folded state, and/or each support column (e.g., the left frame (82), the right frame (83), the rear frame (81)), and the egg container (P) and the gripping portion (31);
(4-1) In the loading operation at least at any stage directly below the folding shelf in a folded state, when the one or more egg containers (P) are placed in a vertical arrangement on the placed egg containers, a horizontal operation is controlled to move the gripping portion (31) and the one or more egg containers (P) in a sucked state horizontally from front to rear into the space below the folding shelf (852) in a folded state while maintaining the egg containers (P) in a horizontal state, in a state in which a front margin clearance (d5) and upper and lower entry clearances (h1, h2) are provided so that the egg containers (P) do not collide with the front restraining portion (8521) of the folding shelf (852) in a folded state,
(5) The one or more egg containers (P) may be placed on the egg container (P) placed vertically so that the distances (d6) to the rear frame (81) are the same (substantially the same) or different. In the loading position, the egg container is released from suction while in contact with or close to the egg container below, and the egg container is removed from the gripping portion.
The horizontal movement in (4-1) above is performed only when loading the topmost shelf directly below the folded shelf at the back, and loading may be performed by "horizontal movement" and/or "diagonal downward movement from front to rear" at other shelves. For example, depending on the loading height, the movement trajectory of the robot hand and gripper may move almost horizontally and then tilt at the end. Also, if it is not directly below the folding shelf, it may be tilted while moving on the way to the loading position.
"Close" refers to a distance of, for example, more than 0 mm and not more than 10 mm or not more than 20 mm.
The positional relationship between the waiting position (W) and the robot arm is not particularly limited, and may be arranged, for example, on the left or right side of the robot arm, in front (between the egg container mailing cart and the robot arm), or at the rear (the egg container transport cart, robot arm, and waiting position are in a straight line in this order).

The "horizontal movement" may satisfy the following conditions:
(1) The sum of the egg container height (Ph) and the upper and lower entry intervals (h2 + h3) is less than or equal to the lower margin interval (h1). (Ph + h2 + h3) ≦ h1
(2) The forward clearance is greater than zero (d5>0)
(3) The upper approach interval is greater than zero (h3>0)
(4) The lower approach interval is greater than zero (h2>0).
The "central region of the egg container" is the region at the intersection of the longitudinal centerline and the lateral centerline of the egg container. It coincides (substantially coincides) with the center of gravity of the egg container in which the eggs are placed.
The “forward clearance distance (d5)” is the distance between the farthest part of the gripping portion (31) and the robot arm (10) in the rear direction and the farthest part of the folding shelf in the folded state in the forward direction (e.g., the forward retaining portion (8521)).
The "lower margin distance (h1)" is the distance between the top (highest position) of the open folding shelf (851) or the topmost egg container in the loaded state and the bottom of the folded folding shelf (852) immediately above the folding shelf (851) in the currently loaded state.
The "lower entry distance (h2)" is the distance between the lowermost height part (lowest position) of the egg container (P) held by the holding portion (31) and the top part (uppermost position) of the folding shelf (851) in the open state or the topmost egg container in the placed state.
The "upper entry distance (h3)" is the distance between the farthest, highest part in the rear direction of the egg container (P) when it is gripped by the gripping portion (31) and the bottom of the folding shelf (852) in the folded state immediately above the folding shelf (851) in the currently loaded state.
The "distance (d6) to the rear frame (81)" is the distance between the rear frame (81) and the farthest part in the rear direction of the placed egg container (P).

The first egg container loading system (A1) grasps the center position of the egg container and can set the forward clearance, upper and lower entry clearances, etc., taking into account the shaking of the egg container due to vibration during high-speed transport, the mechanical dimensional errors of the egg container transport cart, the distortion of the frame, the dimensional errors of the egg container, and the loading position errors, enabling stable high-speed transport without collisions.

The second egg container loading system (A2) comprises:
A robot arm (10);
a gripping portion (31) provided on a hand (11) at the tip of the robot arm (10);
a plurality of suction members (32) provided on the gripping portion (31) for suctioning one or a plurality of egg containers (P);
a loading operation control unit (70) for controlling the robot arm (10) and the gripping unit (31) in accordance with a predetermined loading pattern;
The loading operation control unit (70)
(1) gripping central regions of the one or more egg containers (P) at a waiting position (W) with the gripping unit (31) (so that the central regions of the one or more egg containers (P) and the central region of the gripping unit (31) overlap with each other), transporting the one or more egg containers (P) toward an unfolded folding shelf of an egg container transport cart, and controlling a loading operation of loading the one or more egg containers (P);
(2) In the loading operation, the folding shelf boards are controlled to be vertically arranged along the front-rear direction of the folding shelf boards and horizontally arranged along the left-right direction perpendicular to the front-rear direction in accordance with a loading pattern.
(3) controlling a collision avoidance operation of operating the robot arm (10) so as to avoid collision between the folding shelf (852) in the folded state, the front retaining portion (8521) protruding forward of the folding shelf (852) in the folded state, and/or each support column (e.g., the left frame (82), the right frame (83), the rear frame (81)), and the egg container (P) and the gripping portion (31);
(4-2) In the loading operation at least at any stage directly below the folded folding shelf plate, in order to prevent the one or more egg containers (P) from colliding with the front restraining portion (8521) of the folded folding shelf plate (852) when the one or more egg containers (P) are placed in a vertical arrangement on the placed egg containers, a tilting horizontal operation is controlled to move the gripping portion (31) and the one or more egg containers (P) in a sucked state horizontally from the front to the rear into the space below the folded folding shelf plate (852) in a state in which the gripping portion (31) and the one or more egg containers (P) are tilted in a warping direction (in a warping direction toward the front, with the back side tilted upward and the front side tilted downward) from the folding shelf plate, while providing a front margin clearance (d5) and upper and lower entry clearances (h1, h2) so as not to collide with the front restraining portion (8521) of the folded folding shelf plate (852);
(5) The one or more egg containers (P) may be placed on top of the egg container (P) placed vertically so that the distances (d6) to the rear frame (81) are the same (substantially the same) or different; and/or
(6) A dropping operation may be controlled by transitioning from the tilted horizontal movement to a downward movement, bringing the part of the tilted egg container (P) at the furthest height in the downward direction (the convex part at the lowest position) into contact with or close to the top surface or concave part of the egg container (P) in the placed state, releasing the grip of the tilted egg container, and dropping it onto the egg container below to place it thereon.
The tilted horizontal movement in (4-2) above is performed only when loading the topmost shelf directly below the folded folding shelf (e.g., the fourth shelf in FIG. 3A) and at the rear, and loading may be performed by "horizontal movement" and/or "diagonally downward movement from front to rear" at other shelves. For example, depending on the loading height, the movement trajectory of the robot hand and gripper may move almost horizontally and then tilt at the end. Also, if the shelf is not directly below the folding shelf, the shelf may be tilted while moving on the way to the loading position.
"Close" refers to a distance of, for example, more than 0 mm and not more than 10 mm or not more than 20 mm.
The positional relationship between the waiting position (W) and the robot arm is not particularly limited, and may be arranged, for example, on the left or right side of the robot arm, in front (between the egg container mailing cart and the robot arm), or at the rear (the egg container transport cart, robot arm, and waiting position are in a straight line in this order).

The "inclined horizontal motion" may satisfy the following conditions:
(1) The sum of the egg container height (Ph), the upper and lower entry intervals (h21+h31), and the additional space due to the inclination (h8) is less than or equal to the lower margin interval (h11). (Ph+h21+h31+h8)≦h11
Additional amount due to inclination (h8) = egg container longitudinal length (Pa) × sin θ
Tilt angle: θ
(2) The forward clearance is greater than zero (d51>0)
(3) The upper approach interval is greater than zero (h31>0)
(4) The lower approach interval is greater than zero (h21>0)
The "central region of the egg container" is the region at the intersection of the longitudinal centerline and the lateral centerline of the egg container. It coincides (substantially coincides) with the center of gravity of the egg container in which the eggs are placed.
The "forward clearance distance (d51)" is the distance between the farthest part of the gripping portion (31) and the robot arm (10) in the rear direction and the farthest part of the folding shelf in the folded state in the forward direction (e.g., the forward retaining portion (8521)).
The "lower margin distance (h11)" is the distance between the top (highest position) of the folding shelf (851) in an open state or the topmost egg container in a placed state, and the bottom of the folding shelf (852) in a folded state immediately above the folding shelf (851) in an actually loaded state.
The "lower entry distance (h21)" is the distance between the furthest part (lowest position) of the egg container (P) in the downward direction while it is being held by the holding portion (31) and the top part (uppermost position) of the folding shelf (851) in the open state or the topmost egg container in the placed state.
The "upper entry distance (h31)" is the distance between the farthest, highest part in the rear direction of the egg container (P) when it is gripped by the gripping portion (31) and the bottom of the folding shelf (852) in the folded state immediately above the folding shelf (851) in the currently loaded state.
The "distance (d61) to the rear frame (81)" is the distance between the rear frame (81) and the farthest part in the rear direction of the placed egg container (P).

According to the second egg container loading system (A2), the center position of the egg container is grasped, and the forward clearance, the upper and lower entry clearances, and the like can be set in consideration of shaking of the egg container due to vibration during high-speed transportation, the mechanical dimensional error of the egg container transport cart, the distortion of the frame, the dimensional error of the egg container, and the loading position error, thereby enabling stable high-speed transportation without collisions.
According to the second egg container loading system (A2), the egg container is tilted so that the robot arm (10), the hand (11), the gripping unit (31), and the egg container (P) are arranged on a linear tilting axis, and the egg container can be moved to a predetermined release point (R) without interfering with the folding shelf or its front retaining unit (8521) by moving the egg container to the back side of the egg container transport cart, and released from the gripping (detachment; release) in the tilted state, so that the egg container can be placed on the egg container. When releasing, the release may be performed after a part of the egg container comes into contact with a part of the egg container below. This reduces the impact on the egg container caused by the release.
The second egg container loading system (A2) can be placed further back on the top shelf than the horizontally moving first egg container loading system (A1).

The third egg container loading system (A3) comprises:
A robot arm (10);
a gripping portion (31) provided on a hand (11) at the tip of the robot arm (10);
a plurality of suction members (32) provided on the gripping portion (31) for suctioning one or a plurality of egg containers (P);
a loading operation control unit (70) for controlling the robot arm (10) and the gripping unit (31) in accordance with a predetermined loading pattern;
The loading operation control unit (70)
(1) gripping central regions of the one or more egg containers (P) at a waiting position (W) with the gripping unit (31) (so that the central regions of the one or more egg containers (P) and the central region of the gripping unit (31) overlap with each other), transporting the one or more egg containers (P) toward an unfolded folding shelf of an egg container transport cart, and controlling a loading operation of loading the one or more egg containers (P);
(2) In the loading operation, the folding shelf boards are controlled to be vertically arranged along the front-rear direction of the folding shelf boards and horizontally arranged along the left-right direction perpendicular to the front-rear direction in accordance with a loading pattern.
(3) controlling a collision avoidance operation of operating the robot arm (10) so as to avoid collision between the folding shelf (852) in the folded state, the front retaining portion (8521) protruding forward of the folding shelf (852) in the folded state, and/or each support column (e.g., the left frame (82), the right frame (83), the rear frame (81)), and the egg container (P) and the gripping portion (31);
(4-3) In the loading operation at least at any stage directly below the folded folding shelf plate, when the one or more egg containers (P) are placed in a vertical arrangement on the placed egg container, the gripping portion (31) and the one or more egg containers (P) in a sucked state are moved from the front to the rear (horizontally or diagonally (inclined from the horizontal) downward) toward a space below the folded folding shelf plate (852) (for example, in a state where the gripping portion (31) and the one or more egg containers (P) in a sucked state are moved from the front to the rear (horizontally or diagonally (inclined from the horizontal) downward) (for example, in a state where the gripping portion (31) and the one or more egg containers (P) in a sucked state are moved from the front to the rear) toward a space below the folded folding shelf plate (852) (for example, in a state where the gripping portion (31) and the one or more egg containers (P) in a sucked state) toward a space below the folded folding shelf plate (852) ( For example, (a) horizontal movement while maintaining the egg container (P) in a horizontal state or in a predetermined tilted state, (b) movement from above diagonally downward while maintaining the egg container (P) in a horizontal state (diagonal downward movement operation)), tilting the back side upward and the front side downward in the space below (tilting operation (tilting the egg container in a horizontal state or tilted state)), bringing the furthest part of the lower direction of the tilted egg container (P) (the convex part, corner part, or bottom part at the lowest position) into contact with or close to the top surface or concave part of the egg container (P) placed below in the above-mentioned state, releasing the grip of the tilted egg container (P), and dropping and placing it on the egg container below,
(5) The one or more egg containers (P) may be placed on top of the egg container (P) placed in a vertical position so that the distance (d6) to the rear frame (81) is the same (substantially the same) or different.
The "diagonally downward movement" and "tilting" in (4-3) above may be performed only when loading the topmost shelf directly below the folded folding shelf (e.g., the fourth shelf in FIG. 3A) and at the rear, and loading may be performed by "horizontal movement" and/or "diagonally downward movement" at other shelves. For example, depending on the loading height, the movement trajectory of the robot hand and gripper may move almost horizontally and then tilt at the end. Also, if the shelf is not directly below the folding shelf, the robot hand and gripper may be tilted while moving on the way to the loading position.
"Close" refers to a distance of, for example, more than 0 mm and not more than 10 mm or not more than 20 mm.
The positional relationship between the waiting position (W) and the robot arm is not particularly limited, and may be arranged, for example, on the left or right side of the robot arm, in front (between the egg container mailing cart and the robot arm), or at the rear (the egg container transport cart, robot arm, and waiting position are in a straight line in this order).

According to the third egg container loading system (A3), the center position of the egg container is grasped, and the forward clearance, the upper and lower entry clearances, and the like can be set taking into consideration shaking of the egg container due to vibration during high-speed transportation, mechanical dimensional errors of the egg container transport cart, distortion of the frame, dimensional errors of the egg container, and loading position errors, thereby enabling stable high-speed transportation without collisions.
In addition, according to the third egg container loading system (A3), the egg container can be moved diagonally downward to shorten the moving distance and moving time, and then tilted to move the egg container to the back side of the egg container transport cart without interfering with the folding shelf board or its front retaining part (8521), and the egg container can be placed on the egg container by releasing the grip (detachment; release) in the tilted state. This allows for more stable high-speed movement than the second egg container loading system (A2), and also reduces the risk of collision. When releasing, the release may be performed after a part of the egg container comes into contact with a part of the egg container below. This reduces the impact on the egg container caused by the release.
The third egg container loading system (A3) can be placed further back on the top shelf than the horizontally moving first egg container loading system (A1).

The loading operation control unit (70) of the first, second and third egg container loading systems (A1, A2, A3)
When loading an egg container (regular pack) on top of an egg container (regular pack) placed below, the operation of the robot arm (10) and the gripping part (31) is controlled so that the convex part on the bottom surface of the upper egg container is positioned in the concave part on the top surface of the lower egg container.

The loading operation control unit (70) of the first, second and third egg container loading systems (A1, A2, A3)
The operation of the robot arm (10) and the gripper (31) is controlled so that the egg containers (P) are placed and loaded within the range of the front and rear restraining portions of the folding shelf.
The width and depth of the shelves and the spatial height between the upper and lower plates vary depending on the egg container transport cart. The egg containers also vary in egg size, number of eggs stored, and whether they are flat packs or regular packs. Therefore, the loading operation control requires setting changes each time. Therefore, the loading operation control unit (70) selects a preset loading pattern according to the type of cart and the type of egg container, and controls the operation of the robot arm (10) and the gripping unit (31) so that the egg containers (P) are placed and loaded within the range of the front and rear restraining parts of the folding shelves.
The loading operation control unit (70) of the first, second and third egg container loading systems (A1, A2, A3) may have an acquisition unit (which may receive information from a code reading device) that acquires information on the type of cart and the type of egg container. The type of cart may be acquired by reading an IC tag or a two-dimensional code provided on the cart with a code reading device. The type of egg container may be data from the code reading device, data transmitted from an arbitrary device upstream of the egg container loading system, or information on the type of egg container manually input, and may be determined from an analysis result obtained by analyzing an image obtained by imaging an egg container transported by a transport device from a device that stores and packs egg containers in egg containers with an imaging unit.

The first, second and third egg container loading systems (A1, A2, A3)
The gripping portion (31) may be provided with a sensor portion (proximity sensor, distance sensor, ultrasonic sensor) and/or an imaging portion (omnidirectional camera, wide-angle camera, camera) provided on the side portion (for detection in the horizontal direction, and in diagonal upward and downward directions based on the horizontal direction) and the bottom portion (on the suction member side, for detection toward the egg container).
The loading operation control unit (70) may calculate the position (coordinates) and distance of the detected object from the detection result detected by the sensor unit, and may operate the robot arm to avoid collision with the gripping position of the egg container, the position of the egg container transport cart, the cart frame, or the folding shelf. When there is a risk of collision, the robot arm may be controlled to stop its operation.
The loading operation control unit (70) may calculate the position (coordinates) and distance of the imaged object from the analysis result of the image obtained by the imaging unit, and may operate the robot arm so as to avoid collision with the gripping position of the egg container, the position of the egg container transport cart, the cart frame, or the folding shelf. When there is a risk of collision, the operation of the robot arm may be controlled to stop.

FIG. 1 is a diagram showing the overall configuration of an egg container loading system. FIG. 13 is a diagram showing an example of a suction and gripping position. FIG. 13 is a diagram showing an example of an egg container transport cart. FIG. 13 illustrates the operation of the first egg container loading system. FIG. 13 illustrates an operational description of the first egg container loading system. FIG. 13 illustrates the operation of the second egg container loading system. FIG. 13 illustrates an operational description of the second egg container loading system. 13A-13C are diagrams illustrating the operation of the third egg container loading system. 13A-13C are diagrams illustrating the operation of the third egg container loading system.

(Embodiment 1)
Figure 1A shows the overall configuration of the egg container loading system (A1, A2). 1 is a transport conveyor, P is an egg pack, W is a waiting position, A1 and A2 are egg container loading systems, and 8 is an egg container transport cart. 31 is a gripping unit. Egg packs P are stored in the waiting area W in parallel with the longitudinal direction.
The first and second egg container loading systems A1 and A2 transfer and place a plurality of egg containers P in a waiting area W where a plurality of egg containers P sent from upstream by a transport conveyor 1 are waiting, onto a shelf of an egg container transport cart 8.
Reference numeral 32 denotes an adsorbing member. In this embodiment, the adsorbing member can adsorb and hold five egg containers P. Fig. 1A shows a state in which four egg cartons are adsorbed and held.

Figure 1B shows an example of the position of gripping part 31. Figure 1B(a) shows the center line in the short direction of egg container P, the center line in the long direction, and the center of gripping part 31. Figures 1B(b) to (c) show the arrangement of two or four egg cartons and the position of the planar center of gripping part 31.
In the upper part of Fig. 1B(b), the planar center of the vertically aligned egg packs in an arrangement P1 is offset to the left in the container short-side direction, but not offset in the container long-side direction. In the lower part, the planar center of the vertically aligned egg packs in an arrangement P11 of two egg packs in a row is offset from the planar center of the gripping parts 31 that lie parallel to the long-side direction of the egg packs in both the container short-side direction and the long-side direction. The planar center of the horizontally aligned egg packs in an arrangement P12 is offset from the planar center of the gripping parts 31 that lie parallel to the long-side direction of the egg packs in both the container short-side direction and the long-side direction.
The upper part of Fig. 1B(c) shows that the planar center of the vertically aligned arrangement P2 of egg containers is not offset from the planar center of the gripping parts 31 lying in a direction perpendicular to the longitudinal direction of the egg container in either the short-side direction or the long-side direction of the container. The lower part shows that the planar center of the vertically aligned arrangement P21 of two egg containers is offset from the planar center of the gripping parts 31 lying in a direction parallel to the longitudinal direction of the egg container in either the short-side direction or the long-side direction of the container. The planar center of the horizontally aligned arrangement P22 of egg packs is offset from the planar center of the gripping parts 31 lying in a direction parallel to the longitudinal direction of the egg container in the short-side direction of the container, but is not offset from the planar center in the long-side direction of the container.
In this embodiment, the number of egg containers to be gripped is not limited to four, but one, two, three, or five egg containers can be gripped. The position of the gripping portion 31 can be set in the same manner for other numbers of egg containers.
In order to avoid interference with the rear frame and both side frames of the trolley 8 and the upper folding shelf, the length, direction (front/back, left/right position), rotation direction of the protruding portion of the gripping unit 31 (the area protruding from the outer periphery of multiple egg containers in a plan view), the overall operation of the multi-axis robot arm 10, and the operation of the gripping unit 31 are controlled by the loading control unit 70, which will be described later.

Figure 1C shows an egg container transport cart 8. Commonly available egg container transport carts include, for example, the egg pack-specific transport roll box manufactured by Yoshida Elsys Co., Ltd. shown in the prior art, the roll rack manufactured by San-ei Seisakusho Co., Ltd., and the transport rack described in Patent Document 1. These all have a common configuration that includes a bottom frame, a back frame, both side frames, and multiple folding shelves (sometimes called shelf boards).
In Fig. 1C, the lowest folding shelf 851 is unfolded, egg containers are placed on that shelf, and after a predetermined number of stages have been loaded, the folding shelf 852 above is unfolded, and egg containers are placed on that shelf, etc. The front, right side, and perspective views of Fig. 1C show left frame 82, right frame 83, first folding shelf 851, second folding shelf 852, third folding shelf 853, fourth folding shelf 854, first left shelf support portion 821, second left shelf support portion 822, third left shelf support portion 824, first right shelf support portion 831, second right shelf support portion 832, and third right shelf support portion 834.
1C shows a left caster rail 45, a right caster rail 46, a front cart fixing part 41, a rear cart fixing part 42, a left cart fixing part 43, and a right cart fixing part 44. Each fixing part is provided at the bottom of the cart, but may be disposed at the middle or top of the cart or at the height of each shelf board.

(First egg container loading system)
2A and 2B, a first egg container loading system A1 is illustrated.
The first egg container loading system A1 includes a robot arm 10, a gripping unit 31 provided on a hand 11 at the tip of the robot arm 1), a plurality of suction members 32 provided on the gripping unit 31 for adsorbing one or a plurality of egg containers P, and a loading operation control unit 70 that controls the robot arm 10 and the gripping unit 31 in accordance with a predetermined loading pattern.

The loading operation control unit 70 executes the following operations.
(1) The central region of one or more egg containers P located at waiting position W is gripped by gripping unit 31 (preferably so that the central region of one or more egg containers P overlaps with the central region of gripping unit 31), and the egg containers are transported toward the unfolded folding shelf of egg container transport cart 8, and the loading operation of loading one or more egg containers P is controlled.
(2) In the loading operation, control is performed to arrange the folding shelves vertically along the front-to-rear direction and horizontally along the left-to-right direction perpendicular to the front-to-rear direction in accordance with the loading pattern.
(3) Controlling the collision avoidance operation of operating the robot arm 10, hand 11, and gripping unit 31 so as to avoid collision between the folding shelf 852 in the folded state, the forward retaining portion 8521 protruding forward of the folding shelf 852 in the folded state, and each support (e.g., left frame 82, right frame 83, rear frame 81) and the egg container P and gripping unit 31.
(4-1) In the loading operation at least on any stage directly below the folding shelf in the folded state, when one or more egg containers P are placed in a vertical position on top of the placed egg containers, a horizontal operation is controlled to move the gripping portion 31 and one or more egg containers P in an adsorbed state horizontally from front to rear into the space below the folding shelf 852 in the folded state while maintaining the horizontal state of the egg container P, with a front clearance distance d5 and upper and lower entry distances h1, h2 provided so as not to collide with the front retaining portion 8521 of the folding shelf 852 in the folded state.
(5) One or more egg containers P are placed on the egg container P placed in the vertical position so that the distances d6 to the rear frame 81 are the same (substantially the same) or different.

2A shows an example in which egg containers P are placed between the front retaining portion 8511 and the rear retaining portion 8512 of the first folding shelf 851. The "distances (d6a, d6b) to the rear frame (81)" of the first egg container P1, the third egg container P3, and the fourth egg container P4 from the bottom are the same and are larger than the "distance (d6) to the rear frame (81)" of the second egg container P2. This is because the second egg container P2 is placed so that the convex portion on the bottom fits into the concave portion on the top of the first egg container P1.
In the case where the top surface is flat, the "distance (d6) to the rear frame (81)" of the first to fourth egg containers P1 to P4 from bottom to top may all be the same.

The horizontal movement in (4-1) above is performed only when loading the topmost shelf directly below the folded shelf at the rear, and loading may be performed by "horizontal movement" and/or "diagonal downward movement from front to rear (diagonal downward movement movement)" at other shelves. For example, depending on the loading height, the movement trajectory of the robot hand and gripper may move almost horizontally and then tilt at the end. Also, if the shelf is not directly below the folding shelf, the robot hand and gripper may tilt while moving on the way to the loading position.
The loading operation control unit 70 may arbitrarily select the movement trajectory of the hand and gripper of the robot arm between the standby position W and the loading position (loading position on the folding shelf, loading position on the egg container in the placed state, etc.) within the operation range of the multi-axis robot arm. For example, the movement trajectory is selected so as to move in the shortest possible direction (shortening the time) in response to each loading position and loading pattern. The loading operation control unit 70 may control the movement trajectory of the hand and gripper of the robot arm and the movement trajectory to the loading position of the egg container transport cart in the horizontal/inclined state.

As shown in FIG. 2B, the “horizontal operation” satisfies the following conditions:
(1) The sum of the egg container height (Ph) and the upper and lower entry intervals (h2 + h3) is less than or equal to the lower margin interval (h1). (Ph + h2 + h3) ≦ h1
(2) The forward clearance is greater than zero (d5>0)
(3) The upper approach interval is greater than zero (h3>0)
(4) The lower approach interval is greater than zero (h2>0).
The "central region of the egg container" is the region at the intersection of the longitudinal centerline and the lateral centerline of the egg container. It coincides (substantially coincides) with the center of gravity of the egg container in which the eggs are placed.
The "forward clearance distance (d5)" is the distance between the farthest part of the gripping portion 31 and the robot arm 10 in the rear direction and the farthest part of the folding shelf in the folded state in the forward direction (e.g., the front retaining portion (8521)).
The "lower margin distance (h1)" is the distance between the top (highest position) of folding shelf 851 in an open state or the topmost egg container in a placed state, and the bottom of folding shelf 852 in a folded state immediately above folding shelf 851 in an actually loaded state.
The "lower entry interval (h2)" is the distance between the lowermost height part (lowest position) of the egg container P when it is held by the gripping portion 31 and the top part (uppermost position) of the folding shelf 851 in the open state or the topmost egg container in the placed state.
The "upper entry distance (h3)" is the distance between the farthest, highest part of the egg container P in the rear direction when it is gripped by the gripping portion 31 and the bottom of the folding shelf 852 in the folded state immediately above the folding shelf 851 in the currently loaded state.
The “distance (d6) to the rear frame (81)” is the distance between the rear frame 81 and the farthest part in the rear direction of the egg container P in the placed state.

(Second egg container loading system)
3A and 3B, a second egg container loading system A2 is illustrated.
The second egg container loading system A2 includes a robot arm 10, a gripping unit 31 provided on a hand 11 at the tip of the robot arm 1), a plurality of suction members 32 provided on the gripping unit 31 for adsorbing one or a plurality of egg containers P, and a loading operation control unit 70 that controls the robot arm 10 and the gripping unit 31 in accordance with a predetermined loading pattern.

The loading operation control unit 70 executes the following operations.
(1) The central region of one or more egg containers P located at waiting position W is gripped by gripping unit 31 (preferably so that the central region of one or more egg containers P overlaps with the central region of gripping unit 31), and the egg containers are transported toward the unfolded folding shelf of egg container transport cart 8, and the loading operation of loading one or more egg containers P is controlled.
(2) In the loading operation, control is performed to arrange the folding shelves vertically along the front-to-rear direction and horizontally along the left-to-right direction perpendicular to the front-to-rear direction in accordance with the loading pattern.
(3) Controlling the collision avoidance operation of operating the robot arm 10, hand 11, and gripping unit 31 so as to avoid collision between the folding shelf 852 in the folded state, the forward retaining portion 8521 protruding forward of the folding shelf 852 in the folded state, and each support (e.g., left frame 82, right frame 83, rear frame 81) and the egg container P and gripping unit 31.
(4-2) In the loading operation at least on any stage directly below the folding shelf in the folded state, when one or more egg containers P are placed in a vertical position on top of the egg containers in the placed state, a front clearance distance d5 and upper and lower entry distances h1, h2 are provided so that the egg containers P do not collide with the front retaining portion 8521 of the folding shelf 852 in the folded state. In this state, the holding portion 31 and the one or more egg containers P in the adsorbed state are tilted in a direction warping away from the folding shelf (in a direction warping forward, with the rear side tilted upward and the front side tilted downward), and a tilted horizontal operation is controlled to move the holding portion 31 and the one or more egg containers P horizontally from front to rear into the space below the folding shelf 852 in the folded state.
(5) One or more egg containers P are placed on top of the egg container P placed in the vertical position so that the distance d61a to the rear frame 81 is smaller than the distance d61 between the egg containers below.
(6) The falling operation is controlled by shifting from the tilt horizontal movement to a downward movement, bringing the part of the tilted egg container P at the furthest height in the downward direction (the convex part at the lowest position) into contact with or close to the top surface or concave part of the egg container P in the previously placed state, releasing the grip of the tilted egg container, and dropping it onto the egg container below and placing it thereon. In Fig. 3A, the egg container P is moved to a predetermined release point R, the suction is released, the egg container is released, and it is allowed to fall naturally.

The inclined horizontal movement of (4-2) above is performed only when loading the topmost shelf directly below the folded folding shelf (e.g., the fourth shelf in FIG. 3A) and at the rear, and loading may be performed by "horizontal movement" and/or "diagonally downward movement from front to rear (diagonally downward movement operation)" at other shelves. For example, depending on the loading height, the movement trajectory of the robot hand and gripper may move almost horizontally and then tilt at the end. Also, if it is not directly below the folding shelf, it may be tilted while moving on the way to the loading position.
The loading operation control unit 70 may arbitrarily select the movement trajectory of the hand and gripper of the robot arm between the standby position W and the loading position (loading position on the folding shelf, loading position on the placed egg container, etc.) within the operation range of the multi-axis robot arm. For example, the movement trajectory is selected so as to move the shortest (time-saving) in response to each loading position and loading pattern. The loading operation control unit 70 can control the movement trajectory of the hand and gripper of the robot arm and the movement trajectory of the robot arm to the loading position of the egg container transport cart in the horizontal/inclined state.

3A shows an example in which egg containers P are placed between a front pressing portion 8511 and a rear pressing portion 8512 of a first folding shelf 851. The "distance (d61a) to the rear frame (81)" of the first and third egg containers P1 and P3 from the bottom is the same, and is larger than the "distance (d61) to the rear frame (81)" of the second and fourth egg containers P2 and P4. This is because the egg containers are placed so that the convex portion on the bottom of the upper egg container fits into the concave portion on the top of the lower egg container.
In the case where the top surface is flat, the "distance (d6) to the rear frame (81)" of the first to fourth egg containers P1 to P4 from bottom to top may all be the same.

As shown in FIG. 3B, the “inclined horizontal operation” satisfies the following conditions:
Incline angle: θ (direction of warping from the folding shelf (direction of warping forward), in FIG. 3B, an inclination upward to the right)
Difference in distance to the rear frame 81 (d6-d61) = (egg container height Ph) x sin θ (+ correction value)
Difference in upper entry interval (h3-h31) = (egg container longitudinal length Pa) x sin θ (+ correction value)
The correction value is a correction value for the effects of deformation of the suction member, shaking of the egg container due to high-speed movement, etc., and may be set by teaching.
(1) The sum of the egg container height (Ph), the upper and lower entry intervals (h21+h31), and the additional space due to the inclination (h8) is less than or equal to the lower margin interval (h11). (Ph+h21+h31+h8)≦h11
Additional amount due to inclination (h8) = Egg container longitudinal length (Pa) × sin θ
(2) The forward clearance is greater than zero (d51>0)
(3) The upper approach interval is greater than zero (h31>0)
(4) The lower approach interval is greater than zero (h21>0)
The "central region of the egg container" is the region at the intersection of the longitudinal centerline and the lateral centerline of the egg container. It coincides (substantially coincides) with the center of gravity of the egg container in which the eggs are placed.
The "forward clearance distance (d51)" is the distance between the farthest part of the gripping portion 31 and the robot arm 10 in the rear direction and the farthest part of the folding shelf in the folded state in the forward direction (e.g., the forward retaining portion (8521)).
The "lower margin distance (h11)" is the distance between the top (highest position) of folding shelf 851 in an open state or the topmost egg container in a placed state, and the bottom of folding shelf 852 in a folded state immediately above folding shelf 851 in an actually loaded state.
The "lower entry interval (h21)" is the distance between the lowermost height part (lowest position) of the egg container P when it is held by the gripping portion 31 and the top part (uppermost position) of the folding shelf 851 in the open state or the topmost egg container in the placed state.
The "upper entry distance (h31)" is the distance between the farthest, highest part of the egg container P in the rear direction when held by the holding portion 31 and the bottom of the folding shelf 852 in the folded state immediately above the folding shelf 851 in the currently loaded state.
The “distance (d61) to the rear frame (81)” is the distance between the rear frame 81 and the farthest part in the rear direction of the egg container P in the placed state.

(Third egg container loading system)
4A and 4B, a third egg container loading system A3 is illustrated.
The third egg container loading system A3, like the second egg container loading system A2, comprises a robot arm 10, a gripping unit 31 provided on a hand 11 at the tip of the robot arm 1), a plurality of suction members 32 provided on the gripping unit 31 for adsorbing one or a plurality of egg containers P, and a loading operation control unit 70 that controls the robot arm 10 and the gripping unit 31 in accordance with a predetermined loading pattern.

The loading operation control unit 70 executes the following operations.
(1) The central region of one or more egg containers P located at waiting position W is gripped by gripping unit 31 (preferably so that the central region of one or more egg containers P overlaps with the central region of gripping unit 31), and the egg containers are transported toward the unfolded folding shelf of egg container transport cart 8, and the loading operation of loading one or more egg containers P is controlled.
(2) In the loading operation, the folding shelves are controlled to be vertically arranged along the front-to-rear direction of the folding shelves, or horizontally arranged along the left-to-right direction perpendicular to the front-to-rear direction, in accordance with the loading pattern.
(3) Controlling the collision avoidance operation of operating the robot arm 10, hand 11, and gripping unit 31 so as to avoid collision between the folding shelf 852 in the folded state, the forward retaining portion 8521 protruding forward of the folding shelf 852 in the folded state, and each support (e.g., left frame 82, right frame 83, rear frame 81) and the egg container P and gripping unit 31.
(4-3) In a loading operation at least on any stage directly below the folding shelf plate in the folded state, when one or more egg containers P are placed in a vertical arrangement on the placed egg containers, in a state where the front clearance distance d5 and the upper and lower entry distances h1, h2 are provided so as not to collide with the front restraining portion 8521 of the folding shelf plate 852 in the folded state, the gripping portion 31 and the one or more egg containers P in the adsorbed state are moved from the front to the rear (horizontally or diagonally (inclined from the horizontal) downward) toward the space below the folding shelf plate 852 in the folded state while maintaining the horizontal state of the egg container P. The egg container P is moved (for example, (a) horizontally while maintaining the egg container (P) in a horizontal state or in a predetermined inclined state, (b) moved diagonally downward from above while maintaining the egg container (P) in a horizontal state (diagonal downward movement operation)), and in the space below, the back side is tilted upward and the front side is tilted downward (tilting operation (tilting the egg container in a horizontal or inclined state)), and the convex or bottom part at the lowest position of the tilted egg container P is brought into contact with or close to the top or concave part of the egg container P placed below, the tilted egg container P is released from its grip, and dropped onto the egg container below to be placed thereon, thereby controlling a dropping operation.
(5) One or more egg containers P are placed on top of the egg container P placed in the vertical position so that the distance to the rear frame 81 is smaller than that of the egg container below.
The "diagonally downward movement" and "tilting" in (4-3) above may be performed only when loading the topmost shelf directly below the folded folding shelf (e.g., the fourth shelf in FIG. 3A) and at the rear, and loading may be performed by "horizontal movement" and/or "diagonally downward movement" at other shelves. For example, depending on the loading height, the movement trajectory of the robot hand and gripper may move almost horizontally and then tilt at the end. Also, if the shelf is not directly below the folding shelf, the robot hand and gripper may be tilted while moving on the way to the loading position.
The loading operation control unit 70 can arbitrarily select the movement trajectory of the hand and gripper of the robot arm between the waiting position (W) and the loading position (loading position on the folding shelf, loading position on the placed egg container, etc.) within the operation range of the multi-axis robot arm. For example, the movement trajectory is selected so as to move the shortest (shortest time) in response to each loading position and loading pattern. The loading operation control unit 70 can control the movement trajectory of the hand and gripper of the robot arm and the movement trajectory to the loading position of the egg container transport cart in a horizontal/inclined state.

The "diagonal downward movement operation" moves downward so that the innermost protruding part of the egg container (longitudinal bottom end or top end) does not come into contact with the folded shelf plate 852 in the folded state, depending on the approach angle of the movement, and proceeds until it approaches or comes into contact with the placed egg container, and then the "tilting operation" is executed. When the egg container is tilted, the innermost protruding part (longitudinal top end) of the egg container is tilted so that it does not come into contact with the bottom of the folded shelf plate 852 in the folded state, and the convex or bottom part at the lowest position of the tilted egg container P comes into contact with or approaches the top or concave part of the egg container P in the previously placed state. This tilt causes the egg container to move further toward the back, and when it is leveled again, it is placed in a state where it protrudes further back than the egg container below.

(egg container)
Egg containers include, for example, regular packs which are composed of a container body capable of accommodating convex eggs that conform to the outer shape of the eggs and a lid that fits over the convex eggs, and flat packs which are composed of a container body capable of accommodating convex eggs that conform to the outer shape of the eggs and a flat lid with a flat top surface.

(Robot arm)
The robot arm 10 may be configured as a six-axis robot arm, but may also be a SCARA robot.
The hand 11 at the tip is attached to the tip of the arm and has a fixing part for fixing a gripper 31 .
The gripping portion 31 has, for example, a plurality of negative pressure adsorption members 32. The adsorption members 32 may be, for example, bellows-shaped pads or pads with a trapezoidal cross section.
The suction members 32 are connected to a vacuum pump (or a blower) via a negative pressure pipe, and by sucking air, the suction members 32 generate a suction force capable of gripping an egg container in contact with the suction members 32. Pipes, on-off valves, and the like may be configured and controlled so that all of the suction members 32, each of them, or a plurality of them can perform the operations of "suction, suction stop (suction state), and suction release (return to atmospheric pressure)."

The first, second and third egg container loading systems A1, A2 and A3 may include a dolly fixing means (41, 42, 43, 44, 45 and 46) for positioning and fixing the egg container transport dolly 8 at a preset loading location. "Fixing" means stopping the movement, and the movement can be resumed by releasing the fixation.
The cart fixing means (41, 42, 43, 44, 45, 46) may have positioning means, suction means, clamping means or pressing means, caster rails, etc. for fixing one or more of the pillars (front frame, left frame, right frame, rear frame) of the egg container transport cart 8, the lowest folding shelf board (in an unfolded state), casters, and folding shelves (in an unfolded state) of each stage. The cart fixing means may have positioning means, suction means, clamping means or pressing means for fixing the folding shelf boards in a folded state. This makes it possible to prevent unexpected unfolding.

The first, second and third egg container loading systems A1, A2 and A3 may include a teaching means for teaching the operation of the robot arm 10 in response to information on the egg container transport cart 8 (e.g., cart size, number of folding shelves, coordinates of the space area where the egg container can be loaded on each folding shelf in the egg container transport cart fixed at the loading position), information on the egg containers (e.g., flat pack, regular pack, number of eggs stored, egg container size), and the loading pattern of the egg containers. The teaching means may be a means using any of the following methods: offline teaching, online teaching, direct teaching, and teaching using AI.

(Another embodiment)
The robot arm 10 is configured as a multi-axis robot arm, and each axis arm may be equipped with one or more sensors including a motion sensor (e.g., a 9-axis motion sensor), an angular velocity sensor, an acceleration sensor, an ultrasonic sensor, and a camera.
The robot arm 10 may be equipped with a center-of-gravity position sensor (e.g., a six-axis force angle sensor) that detects the center-of-gravity position of the egg container gripped by the hand 11. The loading operation control unit 70 may control the operation of the robot arm 10 and the gripping unit 31 so as to re-grip the egg container when the positional deviation of the center of gravity detected by the center-of-gravity position sensor is equal to or greater than a threshold value.
The gripping portion provided on the hand 11 of the robot arm 10 may be configured as a claw-type gripping portion or a multi-joint multi-fingered portion (2, 3, 4, 5, 6 or more fingers). The claw-type gripping portion or the multi-joint multi-fingered portion may include a tactile sensor (3-axis or 6-axis force sensor), a slip sensor, or a proximity sensor.

A1 First egg container loading system A2 Second egg container loading system 10 Robot arm 11 Hand 31 Grip unit 32 Suction member 70 Loading operation control unit 8 Egg container transport cart P Egg container W Waiting position

Claims (3)

A robot arm;
a gripping unit provided on a hand at the tip of the robot arm;
A plurality of suction members provided on the gripping portion for suctioning one or a plurality of egg containers;
a loading operation control unit that controls the robot arm and the gripper in accordance with a predetermined loading pattern,
The loading operation control unit includes:
gripping a central region of the one or more egg containers at a standby position with the gripping unit, transporting the one or more egg containers toward an unfolded folding shelf of an egg container transport cart, and controlling a loading operation of loading the one or more egg containers;
In the loading operation, a control is performed to perform a vertical arrangement in which the folding shelf boards are arranged along a front-rear direction and a horizontal arrangement in which the folding shelf boards are arranged along a left-right direction perpendicular to the front-rear direction in accordance with a loading pattern;
controlling a collision avoidance operation of operating the robot arm so as to avoid collision between the folding shelf in a folded state, the front retaining portion and/or each support column protruding forward of the folding shelf in a folded state, and the egg container and the gripping portion;
In the loading operation at least at any stage directly below the folding shelf in a folded state, a tilting horizontal operation is controlled to move the gripping portion and the one or more egg containers in a sucked state horizontally from front to rear in a state inclined in a warping direction from the folding shelf in a state in which a front clearance gap and an upper and lower side entry gaps are provided so that the one or more egg containers do not collide with the front restraining portion of the folding shelf in a folded state when the one or more egg containers are placed on the placed egg container,
placing the one or more egg containers on top of the egg containers placed vertically so that the distances to the rear frame are the same or different;
Egg container loading system. A robot arm;
a gripping unit provided on a hand at the tip of the robot arm;
A plurality of suction members provided on the gripping portion for suctioning one or a plurality of egg containers;
a loading operation control unit that controls the robot arm and the gripper in accordance with a predetermined loading pattern,
The loading operation control unit includes:
gripping a central region of the one or more egg containers at a standby position with the gripping unit, transporting the one or more egg containers toward an unfolded folding shelf of an egg container transport cart, and controlling a loading operation of loading the one or more egg containers;
In the loading operation, a control is performed to perform a vertical arrangement in which the folding shelf boards are arranged along a front-rear direction and a horizontal arrangement in which the folding shelf boards are arranged along a left-right direction perpendicular to the front-rear direction in accordance with a loading pattern;
controlling a collision avoidance operation of operating the robot arm so as to avoid collision between the folding shelf in a folded state, the front retaining portion and/or each support column protruding forward of the folding shelf in a folded state, and the egg container and the gripping portion;
In the loading operation at least at any stage directly below the folded folding shelf, when the one or more egg containers are placed vertically on the placed egg container, the gripping section and the one or more egg containers in the adsorbed state are moved from front to rear toward the space below the folded folding shelf in a state where a front clearance gap and an upper and lower entry gap are provided so that the egg containers do not collide with the front restraining section of the folded folding shelf, and in the lower space, the back side is tilted upward and the front side is tilted downward, and the furthest part of the lower side of the tilted egg container is brought into contact with or close to the top surface or recess of the placed egg container below, the gripping of the tilted egg container is released, and the tilted egg container is dropped onto the egg container below to be placed, and a dropping operation is controlled.
placing the one or more egg containers on top of the egg containers placed vertically so that the distances to the rear frame are the same or different;
Egg container loading system. A robot arm;
a gripping unit provided on a hand at the tip of the robot arm;
A plurality of suction members provided on the gripping portion for suctioning one or a plurality of egg containers;
a loading operation control unit that controls the robot arm and the gripper in accordance with a predetermined loading pattern,
The loading operation control unit includes:
gripping a central region of the one or more egg containers at a standby position with the gripping unit, transporting the one or more egg containers toward an unfolded folding shelf of an egg container transport cart, and controlling a loading operation of loading the one or more egg containers;
In the loading operation, a control is performed to perform a vertical arrangement in which the folding shelf boards are arranged along a front-rear direction and a horizontal arrangement in which the folding shelf boards are arranged along a left-right direction perpendicular to the front-rear direction in accordance with a loading pattern;
controlling a collision avoidance operation for operating the robot arm so as to avoid collision with the folding shelf in a folded state, a front retaining portion protruding forward of the folding shelf in a folded state, and/or each support;
In the loading operation at least on any stage directly below the folding shelf in the folded state, a horizontal operation is controlled to move the gripping portion and the one or more egg containers in the adsorbed state horizontally from front to rear in a state in which a front clearance gap and an upper and lower entry gaps are provided so that the one or more egg containers do not collide with the front restraining portion of the folding shelf in the folded state when the one or more egg containers are placed on the placed egg container,
placing the one or more egg containers on top of the egg containers placed vertically so that the distances to the rear frame are the same or different;
Egg container loading system.