Method of control

Abstract

To provide a technique capable of preventing a sagger from rattling in a vertical direction.SOLUTION: A grasping method is a method of grasping a sagger carried out from a heat treatment furnace. The gripping method includes a step of grasping the sagger by a pair of grasping members movable in a left-right direction, and a step of moving the sagger grasped by the pair of grasping members in an up-down direction orthogonal to the left-right direction with respect to the grasping members and positioning the sagger at a predetermined position.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a gripping method for gripping a sagger. [Background technology]

[0002] Patent Document 1 discloses a gripping method for gripping a sagger using a robot hand. The robot hand grips a sagger carried out from a heat treatment furnace. The robot hand has a pair of gripping members that can open and close in the left-right direction, and a pair of claws that are arranged on the upper and lower sides of the gripping surface for gripping the sagger. When the sagger is gripped by the pair of gripping members, the sagger is positioned between the pair of claws, preventing the sagger from falling from the gripping members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6949260 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above gripping method, the pair of claws is immovably provided on the gripping member, and the distance between the pair of claws is fixed, so when the robot hand grips the sagger, the sagger rattles between the pair of claws.

[0005] This specification discloses a technique that can prevent the sagger from rattling in the vertical direction. [Means for solving the problem]

[0006] In a first aspect of the technology disclosed herein, a gripping method is a method for gripping a sagger carried out from a heat treatment furnace, the gripping method comprising the steps of gripping the sagger with a pair of gripping members movable in a left-right direction, and moving the sagger gripped by the pair of gripping members in a vertical direction perpendicular to the left-right direction relative to the gripping members to position the sagger at a predetermined position.

[0007] According to the above configuration, the sagger is positioned at a predetermined position in the vertical direction after being gripped by the pair of gripping members, thereby making it possible to prevent the sagger from rattling in the vertical direction. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a heat treatment system according to a first embodiment. [Figure 2] FIG. 1 is a schematic diagram of a heat treatment system according to a first embodiment. [Figure 3] FIG. 1 is a perspective view of a robot hand according to a first embodiment. [Figure 4] FIG. 2 is a perspective view of the right hand arm of the robot hand of the first embodiment. [Figure 5] FIG. 10 is a cross-sectional view of the first right hand arm portion, the left hand arm portion, and the cooling mechanism when the first right gripping member, the second right gripping member, the first left gripping member, and the second left gripping member are located at a second position in the first embodiment. [Figure 6] FIG. 2 is a perspective view of the left hand arm of the robot hand of the first embodiment. [Figure 7] FIG. 10 is a cross-sectional view of the first right hand arm portion, the left hand arm portion, and the cooling mechanism when the first right gripping member, the second right gripping member, the first left gripping member, and the second left gripping member are located at a first position in the first embodiment. [Figure 8] FIG. 2 is a cross-sectional view of the sagger and hand arm when the shutter is in the open position in the first embodiment. [Figure 9] FIG. 2 is a cross-sectional view of the sagger and hand arm when the shutter is in a closed position in the first embodiment. [Figure 10]FIG. 10 is a top view of the sagger and hand arm after the preparation step in the first embodiment. [Figure 11] FIG. 10 is a top view of the sagger and the hand arm after the first gripping step or the second gripping step in the first embodiment. [Figure 12] FIG. 10 is a side view of the sagger and the hand arm after the first gripping step or the second gripping step in the first embodiment. [Figure 13] FIG. 10 is a side view of the sagger and hand arm after the lifting process in the first embodiment. [Figure 14] FIG. 10 is a side view of the sagger and the hand arm after the positioning step in the first embodiment. [Figure 15] FIG. 10 is a side view of the sagger and the hand arm after the first inversion step in the first embodiment. [Figure 16] FIG. 10 is a side view of the sagger and the hand arm after the second movement step in the first embodiment. [Figure 17] FIG. 10 is a side view of the sagger and the hand arm after the grip releasing step in the first embodiment. [Figure 18] FIG. 10 is a side view of the sagger and the hand arm after the first gripping step in the second embodiment. [Figure 19] FIG. 10 is a top view of the hand arm of the second embodiment. [Figure 20] FIG. 10 is a side view of the sagger and the hand arm before the second right pressing member, the third right pressing member, the second left pressing member, and the third left pressing member move in the positioning step in the second embodiment. [Figure 21] FIG. 10 is a side view of the sagger and the hand arm after the positioning step in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The main features of the embodiments described below are listed below. Note that the technical elements described below are independent technical elements that exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

[0010] In a second aspect of the technology disclosed in this specification, in the first aspect described above, the gripping method further includes a step of positioning a first claw above or below the sagger. The step of positioning in the vertical direction is performed by pressing the sagger against the first claw. According to the above configuration, by pressing the sagger against the first claw, it is possible to prevent the sagger from rattling in the vertical direction.

[0011] In a third aspect of the technology disclosed in this specification, in the second aspect described above, the gripping method further includes a step of placing a second claw on either the upper or lower side of the sagger where the first claw is not placed. The steps of placing the first claw and placing the second claw result in the sagger being placed between the first claw and the second claw. According to the above configuration, the sagger is placed between the first claw and the second claw in the up-down direction, which makes it possible to prevent the sagger from falling from the gripping member.

[0012] In a fourth aspect of the technology disclosed herein, the gripping method of the third aspect described above further includes a step of lifting the sagger gripped by the pair of gripping members after placing the sagger between the first and second jaws. The vertical positioning step is performed after the lifting step. For example, if the vertical positioning step is performed before the lifting step, the vertical positioning member may collide with a member other than the gripped sagger. This configuration can prevent the vertical positioning member from colliding with a member other than the gripped sagger, for example, a sagger positioned below the gripped sagger among multiple stacked saggers.

[0013] In a fifth aspect of the technology disclosed in this specification, in any one of the first to fourth aspects, the gripping method further includes a step of positioning the sagger gripped by the pair of gripping members in a front-to-rear direction perpendicular to the left-to-right direction and the up-to-down direction. According to the above configuration, it is possible to prevent the sagger from wobbling in the front-to-rear direction. It is also possible to prevent the sagger from moving in the front-to-rear direction. This makes it possible to prevent the sagger from shifting its position in the front-to-rear direction.

[0014] In a sixth aspect of the technology disclosed in this specification, the vertical positioning step and the front-rear positioning step in the fifth aspect are performed simultaneously. This configuration simplifies the gripping method. Furthermore, the time required for positioning can be shortened compared to a configuration in which the vertical positioning step and the front-rear positioning step are performed separately.

[0015] In a seventh aspect of the technology disclosed in this specification, in any one of the first to sixth aspects, the gripping method further includes, after the step of positioning in the vertical direction, a step of moving the sagger gripped by the pair of gripping members to a collection container, and a step of inverting the sagger gripped by the pair of gripping members above the collection container after the sagger has moved to the collection container. According to the above configuration, the material in the sagger can be collected into the collection container.

[0016] In an eighth aspect of the technology disclosed in this specification, in any one of the first to seventh aspects, the gripping method further includes, after the step of positioning in the vertical direction, a step of gripping the sagger with the pair of gripping members with a second gripping force that is greater than a first gripping force with which the pair of gripping members grip the sagger. With the above configuration, it is possible to further prevent the sagger from rattling.

[0017] (First Example) As shown in FIG. 1, the heat treatment system 10 includes a heat treatment furnace 12, a transfer device 14, a robot 16, and a control device 18.

[0018] The heat treatment furnace 12 heat-treats the workpiece 4 (see FIG. 10) in the sagger 2. The sagger 2 has a roughly rectangular box shape with an open top. The sagger 2 has multiple notches 2a. The notches 2a are located on each of the four side walls of the sagger 2. Two of the notches 2a face each other, and the remaining two face each other. The notches 2a are located at the top of the sagger 2. The notches 2a connect the inside and outside of the sagger 2. The multiple saggers 2 are stacked vertically. The multiple saggers 2 are placed on a base plate 8 via spacers 6. Therefore, the sagger 2 located at the bottom of the multiple stacked saggers 2 is separated from the base plate 8 and does not abut against it. The object to be treated 4 is, for example, a raw material for a ceramic capacitor, or a positive or negative electrode material for a lithium ion battery.

[0019] The heat treatment furnace 12 is a thermally insulated structure having a substantially rectangular parallelepiped shape. The heat treatment furnace 12 has a loading entrance 20, an unloading exit 22 opposite the loading entrance 20, and a heat treatment space 24. The heat treatment space 24 is in communication with the space outside the heat treatment furnace 12 via the loading entrance 20 and the unloading exit 22.

[0020] The conveying device 14 includes a guide member 28 and a pusher 30. The guide member 28 is disposed across the heat treatment space 24 and the space outside the heat treatment furnace 12. The base plate 8 is placed on the guide member 28. The pusher 30 is configured to press the base plate 8 on the guide member 28. The pusher 30 repeatedly presses the base plate 8 under the control of the control device 18, causing the base plate 8 to move while being guided by the guide member 28. As a result, the sagger 2 and base plate 8 are carried from the space outside the heat treatment furnace 12 into the heat treatment space 24 through the carry-in opening 20, pass through the heat treatment space 24, and then are carried out from the heat treatment space 24 to the space outside the heat treatment furnace 12 through the carry-out opening 22. The workpiece 4 in the sagger 2 is fired, i.e., heat-treated, by a heater (not shown) in the heat treatment space 24 while passing through the heat treatment space 24.

[0021] The robot 16 is located in the external space of the heat treatment furnace 12. The robot 16 is located near the discharge port 22. As shown in FIG. 2, the robot 16 grasps the sagger 2 discharged from the discharge port 22 and recovers the heat-treated workpiece 4 in the sagger 2 into a recovery container 34. The control device 18 controls the robot 16 based on the position and posture of the sagger 2 detected by a sagger detection device 36. The sagger detection device 36 is, for example, a camera.

[0022] The robot 16 is an articulated robot. The robot 16 includes a base 40, a robot arm 42, and a robot hand 44. The robot arm 42 is attached to the base 40. The robot arm 42 is, for example, a six-axis articulated robot arm. The robot arm 42 is rotatable about an axis AX1 extending in the vertical direction, an axis AX2 substantially perpendicular to the vertical direction, an axis AX3 substantially perpendicular to the vertical direction, an axis AX4 substantially perpendicular to the axis AX3, an axis AX5 substantially perpendicular to the vertical direction, and an axis AX6 substantially perpendicular to the axis AX5. The position and posture of the robot hand 44 are adjusted by the rotation of the robot arm 42. Note that the axis about which the robot arm 42 rotates is not limited to the above configuration.

[0023] The robot hand 44 is attached to the tip of the robot arm 42. The robot hand 44 grasps the sagger 2. As shown in FIG. 3, the robot hand 44 includes a base portion 48, an attachment member 50, a heat shielding member 52, and a pair of hand arm portions 54, 56. In the following description of the robot hand 44, the direction in which the hand arm portions 54, 56 extend will be referred to as the front-to-rear direction, the direction perpendicular to the front-to-rear direction will be referred to as the up-to-down direction, and the direction perpendicular to the front-to-rear direction and the up-to-down direction will be referred to as the left-to-right direction.

[0024] The base portion 48 includes an arm support member 64 and a frame member 66. The arm support member 64 supports the pair of hand arm portions 54, 56. The arm support member 64 is made of, for example, a metal material. The arm support member 64 extends in the left-right direction.

[0025] The frame member 66 is attached to the upper end of the arm support member 64. The frame member 66 is made of, for example, a metal material. The metal material is, for example, aluminum. The frame member 66 has a hollow shape. Therefore, the frame member 66 can be made lighter than a frame member 66 that does not have a hollow shape.

[0026] The mounting member 50 is attached to the rear end of the frame member 66. The mounting member 50 enables the frame member 66 to be attached to the tip of the robot arm 42 (see FIG. 2). The mounting member 50 is disposed between the frame member 66 and the robot arm 42. The mounting member 50 is made of, for example, a cement-based material or a calcium silicate-based material. The thermal conductivity of the mounting member 50 is lower than that of the arm support member 64 and that of the frame member 66 (i.e., lower than that of the base portion 48). This prevents heat from the sagger 2 from being transferred from the base portion 48 to the robot arm 42 via the mounting member 50. The mounting member 50 may include a metal member and an insulating sheet sandwiched between the metal member and the tip of the robot arm 42.

[0027] The heat shield 52 is attached to the front end of the arm support member 64 and the front end of the frame member 66. The heat shield 52 has a plate shape. The heat shield 52 is made of, for example, a metal material. The metal material is, for example, stainless steel. When the robot hand 44 is holding the sagger 2 (see FIG. 2), the heat shield 52 is disposed between the sagger 2 and the arm support member 64 and is spaced apart from the sagger 2. This prevents radiant heat from the sagger 2 from being transmitted to the arm support member 64 and the frame member 66. The heat shield 52 may include a metal member and a heat insulating material disposed on the surface of the metal member facing the sagger 2.

[0028] The pair of hand arm sections 54, 56 includes a right hand arm section 54 and a left hand arm section 56. The right hand arm section 54 and the left hand arm section 56 are arranged with a gap between them in the left-right direction. The right hand arm section 54 is symmetrical to the left hand arm section 56 with respect to an imaginary plane P1. The imaginary plane P1 is a plane that includes the up-down direction and the front-back direction, and passes through the center of the robot hand 44 in the left-right direction.

[0029] As shown in FIG. 4, the right hand arm portion 54 includes a right hand arm 70, a first right gripping member 72, a second right gripping member 74, a first right claw 76, a second right claw 78, a first right pressing member 80, and a second right pressing member 82.

[0030] The right hand arm 70 is made of, for example, a metal material. This increases the strength of the right hand arm 70. The metal material is, for example, stainless steel or aluminum. The right hand arm 70 has a substantially rectangular parallelepiped shape. The right hand arm 70 extends forward from the arm support member 64. The right hand arm 70 is movable left and right relative to the arm support member 64. The right hand arm 70 moves under the control of an arm drive device (not shown) by the control device 18 (see FIG. 2).

[0031] As shown in FIG. 5, the right hand arm 70 has a hollow shape. The right hand arm 70 has a first opening 86, a second opening 88, and an internal space 90. The first opening 86 and the second opening 88 are disposed in the rear wall 70a of the right hand arm 70. The first opening 86 and the second opening 88 penetrate the rear wall 70a. The first opening 86 and the second opening 88 are disposed spaced apart in the vertical direction. The internal space 90 is in communication with the first opening 86 and the second opening 88.

[0032] As shown in FIG. 4, the first right gripping member 72 and the second right gripping member 74 are made of, for example, ceramics. The ceramics are, for example, oxide ceramics or non-oxide ceramics. The first right gripping member 72 and the second right gripping member 74 are attached to the left wall 70b of the right hand arm 70. The first right gripping member 72 and the second right gripping member 74 have a substantially rectangular parallelepiped shape. The first right gripping member 72 and the second right gripping member 74 are arranged with a gap between them in the front-to-rear direction.

[0033] The first right claw 76 is made of, for example, ceramics. The ceramics are, for example, oxide ceramics or non-oxide ceramics. The first right claw 76 is attached to the upper wall 70c of the right hand arm 70. The first right claw 76 protrudes leftward from the upper wall 70c beyond the left wall 70b. The first right claw 76 is positioned above the first right gripping member 72 and the second right gripping member 74.

[0034] The second right claw 78 is made of, for example, ceramics. The ceramics are, for example, oxide-based ceramics or non-oxide-based ceramics. The second right claw 78 is attached to the lower wall 70d of the right hand arm 70. The second right claw 78 protrudes leftward from the lower wall 70d beyond the left wall 70b. The second right claw 78 is positioned lower than the first right gripping member 72 and the second right gripping member 74. The first right gripping member 72 and the second right gripping member 74 are positioned between the first right claw 76 and the second right claw 78 in the up-down direction. The second right claw 78 is positioned at a distance from the first right claw 76 in the up-down direction. The left-right length of the first right claw 76 protruding from the left wall 70b is shorter than the length of the second right claw 78 protruding from the left wall 70b.

[0035] The first right pressing member 80 and the second right pressing member 82 are made of, for example, ceramics. The ceramics are, for example, oxide-based ceramics or non-oxide-based ceramics. The first right pressing member 80 and the second right pressing member 82 are attached to the left wall 70b of the right hand arm 70. The first right pressing member 80 is rotatable about a rotation axis AX10 extending in the left-right direction. The first right pressing member 80 rotates between a first position and a second position. The second right pressing member 82 is rotatable about a rotation axis AX11 extending in the left-right direction. The rotation axis AX10 is approximately parallel to the rotation axis AX11. The second right pressing member 82 rotates between a first position and a second position. The first right pressing member 80 is disposed at a distance from the second right pressing member 82 in the front-rear direction. The first right pressing member 80 is disposed forward of the second right pressing member 82. In the front-to-rear direction, the first right gripping member 72, the second right gripping member 74, the first right claw 76, and the second right claw 78 are disposed between the first right pressing member 80 and the second right pressing member 82.

[0036] The first right pressing member 80 has a substantially L-shape. The first right pressing member 80 includes a first contact portion 94 and a second contact portion 96. The first contact portion 94 is rotatably attached to the left wall 70b of the right hand arm 70. The second contact portion 96 protrudes from the lower end of the first contact portion 94 in a direction approaching the second right pressing member 82. The second contact portion 96 is substantially perpendicular to the first contact portion 94.

[0037] The second right pressing member 82 has a substantially L-shape. The second right pressing member 82 includes a first contact portion 100 and a second contact portion 102. The second contact portion 102 is rotatably attached to the left wall 70b of the right hand arm 70. The second contact portion 102 protrudes from the lower end of the first contact portion 100 in a direction approaching the first right pressing member 80. The second contact portion 102 is substantially perpendicular to the first contact portion 100.

[0038] 6, the left hand arm section 56 includes a left hand arm 110, a first left gripping member 112, a second left gripping member 114, a first left claw 116, a second left claw 118, a first left pressing member 120, and a second left pressing member 122. The left hand arm 110, the first left gripping member 112, the second left gripping member 114, the first left claw 116, the second left claw 118, the first left pressing member 120, and the second left pressing member 122 are disposed at intervals in the left-right direction from the right hand arm 70, the first right gripping member 72, the second right gripping member 74, the first right claw 76, the second right claw 78, the first right pressing member 80, and the second right pressing member 82, respectively. The left hand arm 110, the first left gripping member 112, the second left gripping member 114, the first left claw 116, the second left claw 118, the first left pressing member 120, and the second left pressing member 122 are respectively symmetrical with the right hand arm 70, the first right gripping member 72, the second right gripping member 74, the first right claw 76, the second right claw 78, the first right pressing member 80, and the second right pressing member 82 with respect to the imaginary plane P1 (see FIG. 3). The shape and material of the left hand arm 110 are the same as those of the right hand arm 70. The materials of the first left gripping member 112, the second left gripping member 114, the first left claw 116, the second left claw 118, the first left pressing member 120, and the second left pressing member 122 are the same as the materials of the first right gripping member 72, the second right gripping member 74, the first right claw 76, the second right claw 78, the first right pressing member 80, and the second right pressing member 82, respectively.

[0039] The left hand arm 110 is movable in the left-right direction relative to the arm support member 64. The left hand arm 110 moves under the control of an arm drive device (not shown) by the control device 18 (see FIG. 2). The configuration of the left hand arm 110 is substantially the same as the configuration of the right hand arm 70. Therefore, as shown in FIG. 5, the left hand arm 110 has a first opening 86, a second opening 88, and an internal space 90. The first opening 86 and the second opening 88 penetrate a rear wall 110a of the left hand arm 110.

[0040] 6, the first left gripping member 112 and the second left gripping member 114 are attached to the right wall 110b of the left hand arm 110. The right wall 110b of the left hand arm 110 faces the left wall 70b of the right hand arm 70. The configuration of the first left gripping member 112 is substantially the same as the configuration of the first right gripping member 72, and the configuration of the second left gripping member 114 is substantially the same as the configuration of the second right gripping member 74.

[0041] The first left claw 116 protrudes rightward from the upper wall 110c of the left hand arm 110 toward the first right claw 76. The second left claw 118 protrudes rightward from the lower wall 110d of the left hand arm 110 toward the second right claw 78. The length in the left-right direction of the first left claw 116 protruding from the right wall 110b is shorter than the length of the second left claw 118 protruding from the right wall 110b.

[0042] The first left pressing member 120 and the second left pressing member 122 are attached to the right wall 110b of the left hand arm 110. The configuration of the first left pressing member 120 is substantially the same as the configuration of the second right pressing member 82. Therefore, the first left pressing member 120 has a first abutment portion 100 and a second abutment portion 102. The first left pressing member 120 is rotatable around a rotation axis AX12 extending in the left-right direction. The first left pressing member 120 rotates between a first position and a second position. The configuration of the second left pressing member 122 is substantially the same as the configuration of the first right pressing member 80. Therefore, the second left pressing member 122 has a first abutment portion 94 and a second abutment portion 96. The second left pressing member 122 is rotatable around a rotation axis AX13 extending in the left-right direction. The second left pressing member 122 rotates between a first position and a second position.

[0043] As shown in FIG. 5, the robot hand 44 further includes driving devices 130 and 132 and link units 134 and 136. The driving devices 130 and 132 are simultaneously controlled by the control device 18 (see FIG. 2). The driving device 130 and the link unit 134 are disposed in the internal space 90 of the right hand arm 70. The link unit 134 connects the first right pressing member 80 and the second right pressing member 82. The link unit 134 is operated by the driving device 130. As a result, the link unit 134 simultaneously rotates the first right pressing member 80 and the second right pressing member 82. The driving device 132 and the link unit 136 are disposed in the internal space 90 of the left hand arm 110. The link unit 136 connects the first left pressing member 120 and the second left pressing member 122. The link unit 136 is operated by the driving device 132. As a result, the link unit 136 simultaneously rotates the first left pressing member 120 and the second left pressing member 122. The configuration of the drive device 130 is substantially the same as the configuration of the drive device 132, and the configuration of the link unit 134 is substantially the same as the configuration of the link unit 136. For this reason, the following description will be given taking the drive device 130 and the link unit 134 as examples.

[0044] The driving device 130 is disposed closer to the first opening 86 and the second opening 88 than the link unit 134. The driving device 130 is configured, for example, by a cylinder and a piston rod that is moved forward and backward by the cylinder.

[0045] The link unit 134 includes a first member 140, a second member 142, and a connecting member 144. The first member 140, the second member 142, and the connecting member 144 each have an elongated plate shape.

[0046] One end of the first member 140 is rotatably attached to the drive end of the drive device 130. A central portion of the first member 140 is directly or indirectly attached to the second right pressing member 82, and the two are integrated together. The first member 140 is rotatable around a rotation axis AX11, and when the first member 140 rotates, the second right pressing member 82 also rotates.

[0047] One end of the second member 142 is directly or indirectly attached to the first right pressing member 80, and the two are integrated together. The second member 142 is rotatable around a rotation axis AX10, and when the second member 142 rotates, the first right pressing member 80 also rotates.

[0048] The connecting member 144 is rotatably attached to the other end of the first member 140 and the other end of the second member 142 .

[0049] 5 and 7, when the driving device 130 operates, one end of the first member 140 is operated by the driving device 130. As a result, the first member 140 rotates around the rotation axis AX11. Furthermore, as the first member 140 rotates, one end of the connecting member 144 is operated, and the other end of the connecting member 144 operates one end of the second member 142, causing the second member 142 to rotate around the rotation axis AX10. As a result, the first right pressing member 80 rotates from the first position to the second position, and simultaneously the second right pressing member 82 rotates from the first position to the second position, or alternatively, the first right pressing member 80 rotates from the second position to the first position, and simultaneously the second right pressing member 82 rotates from the second position to the first position.

[0050] The robot hand 44 further includes a cooling mechanism 150. The cooling mechanism 150 is provided on the right hand arm 70 and the left hand arm 110. The cooling mechanism 150 includes a supply device 152.

[0051] The supply device 152 is configured to supply a fluid (refrigerant) to the right hand arm 70 and the left hand arm 110 under the control of the control device 18 (see FIG. 2). The fluid may be, for example, a cooling gas or compressed air. In a variant, the fluid may be a liquid such as water. The supply device 152 is attached to the first opening 86 and the second opening 88 of the right hand arm 70 and the first opening 86 and the second opening 88 of the left hand arm 110. The supply device 152 supplies the fluid to the internal space 90 via the first opening 86 of the right hand arm 70 and the first opening 86 of the left hand arm 110. The right hand arm 70 and the left hand arm 110 are cooled by the fluid flowing through the internal space 90. Note that in FIGS. 5 and 7, the direction of the fluid flow is indicated by arrows. After flowing through the internal space 90, the fluid is discharged to the outside of the internal space 90 via the second opening 88 of the right hand arm 70 and the second opening 88 of the left hand arm 110. Note that a flow path through which the fluid flows may be formed in the internal space 90, and the flow path may control the flow of the fluid in the internal space 90. This prevents the fluid from taking a shortcut from the first opening 86 to the second opening 88, and allows the entire hand arm 70, 110 to be efficiently cooled. The flow path through which the fluid flows may be formed by a pipe arranged in the internal space 90. In this configuration, the pipe may have multiple outlets, and the fluid may be ejected to the outside of the pipe through the multiple outlets.

[0052] As shown in FIG. 8, the robot hand 44 further includes a shutter 160 and a sagger detection sensor 162.

[0053] The shutter 160 is movably attached to the heat shield member 52. The shutter 160 moves between an open position and a closed position under the control of the control device 18 (see FIG. 2). When the shutter 160 is in the open position, it opens an opening 166 in the heat shield member 52 and an opening 168 in the arm support member 64. As shown in FIG. 9, when the shutter 160 is in the closed position, it closes the opening 166 in the heat shield member 52 and the opening 168 in the arm support member 64.

[0054] The sagger detection sensor 162 is disposed inside the arm support member 64. The sagger detection sensor 162 detects whether the sagger 2 is disposed in a predetermined position. The sagger detection sensor 162 is, for example, a laser-type sensor. As shown in FIG. 8, when the shutter 160 is in the open position, the sagger detection sensor 162 emits a laser beam toward an opening 166 in the heat insulating member 52 and an opening 168 in the arm support member 64 under the control of the control device 18 (see FIG. 2). When the sagger detection sensor 162 receives the laser beam within a predetermined period after emitting the laser beam, the sagger 2 is disposed in a predetermined position.

[0055] 10 to 17, under the control of the control device 18 (see FIG. 2), the robot 16 grasps the sagger 2 carried out from the heat treatment furnace 12 (see FIG. 1), recovers the workpiece 4 inside the sagger 2, and places the sagger 2 on the base plate 8. The robot 16 sequentially executes a preparation step, a first grasping step, a lifting step, a positioning step, a second grasping step, a first moving step, a first reversing step, a second reversing step, a second moving step, a positioning release step, a lowering step, and a gripping release step.

[0056] As shown in FIG. 10, in the preparation step, the robot arm 42 (see FIG. 2) operates based on the position and posture of the sack 2 detected by the sack detection device 36 (see FIG. 2), and the robot hand 44 moves so that the sack 2 is positioned between the right hand arm 70 and the left hand arm 110. Next, as shown in FIG. 8, the shutter 160 moves from the closed position to the open position, and the sack detection sensor 162 emits a laser. When the control device 18 (see FIG. 2) detects that the sack detection sensor 162 has received the laser within a predetermined period, the shutter 160 moves from the open position to the closed position. This makes it possible to suppress the transfer of heat from the sack 2 to the sack detection sensor 162, compared to a configuration in which the shutter 160 is always in the closed position. Thereafter, the first gripping step is executed.

[0057] 11 and 12 , in the first gripping step, the right hand arm 70 and the left hand arm 110 move toward each other. As a result, the sack 2 is sandwiched between the first right gripping member 72 and the first left gripping member 112 and between the second right gripping member 74 and the second left gripping member 114. The sack 2 is gripped with a first gripping force by the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114. At this time, the sack 2 is in contact with the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114, but is not in contact with the right hand arm 70 and the left hand arm 110. By forming clearances between the sack 2 and the right hand arm 70 and between the sack 2 and the left hand arm 110, heat transfer from the sack 2 to the right hand arm 70 and the left hand arm 110 can be suppressed compared to a configuration in which the sack 2 abuts against the right hand arm 70 and the left hand arm 110. Furthermore, as shown in FIG. 5 , fluid passes through the internal space 90 of the right hand arm 70 and the left hand arm 110, preventing the right hand arm 70 and the left hand arm 110 from becoming too hot. This prevents malfunctions of the hand arm sections 54, 56, i.e., the robot hand 44. Furthermore, because the first opening 86 and the second opening 88 are located in the rear walls 70a, 110a, interference between the supply device 152 and the sack 2 can be suppressed.

[0058] As shown in FIGS. 11 and 12, by moving the right hand arm 70 and the left hand arm 110, the first right claw 76 and the first left claw 116 are inserted into the notches 2a of the sack 2 to be gripped. As a result, the first right claw 76 and the first left claw 116 are positioned above the sack 2 to be gripped. Also, the second right claw 78 and the second left claw 118 (see FIG. 6) are inserted into the notches 2a of the sack 2 located below the sack 2 to be gripped. As a result, the second right claw 78 and the second left claw 118 are positioned below the sack 2 to be gripped (i.e., on the side where the first right claw 76 and the first left claw 116 are not positioned). As a result, the sack 2 is positioned between the first right claw 76 and the second right claw 78 and between the first left claw 116 and the second left claw 118. When the sack 2 to be gripped is placed on the spacer 6 (see FIG. 2), the second right claw 78 and the second left claw 118 are inserted between the sack 2 and the base plate 8 (see FIG. 2). In the first gripping step, a step of gripping the sack 2 with the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114, a step of arranging the first right claw 76 and the first left claw 116 above the sack 2, and a step of arranging the second right claw 78 and the second left claw 118 below the sack 2 are carried out simultaneously.

[0059] After the right hand arm 70 and the left hand arm 110 move closer to each other, the shutter 160 moves from the closed position to the open position, and the sagger detection sensor 162 emits a laser, as shown in Figure 8. When the control device 18 (see Figure 2) detects that the sagger detection sensor 162 has received the laser within a predetermined period of time, the shutter 160 moves from the open position to the closed position. Then, the lifting process is performed.

[0060] As shown in Fig. 13, in the lifting process, the robot arm 42 (see Fig. 2) operates to move the robot hand 44 upward. As a result, the sack 2 is lifted by the robot hand 44 and separated from the sack 2 on the base plate 8. If the sack 2 to be gripped is placed on a spacer 6, the sack 2 also separates from the spacer 6. When the sack 2 is lifted by the robot arm 42, it is placed on the second right claw 78 and the second left claw 118. In this state, clearances are formed between the sack 2 and the first right claw 76, and between the sack 2 and the second left claw 118.

[0061] As shown in Fig. 7, in the positioning step after the lifting step, the drive devices 130, 132 operate simultaneously, causing the link unit 134 to operate the first right pressing member 80 and the second right pressing member 82 simultaneously, and the link unit 136 to operate the first left pressing member 120 and the second left pressing member 122 simultaneously. As shown in Fig. 14, the first right pressing member 80, the second right pressing member 82, the first left pressing member 120 (see Fig. 6), and the second left pressing member 122 (see Fig. 6) rotate simultaneously from the second position to the first position. As a result, the second abutment portion 96 of the first right pressing member 80, the second abutment portion 102 of the second right pressing member 82, the second abutment portion 102 of the first left pressing member 120, and the second abutment portion 96 of the second left pressing member 122 come into vertical contact with the underside of the sack 2, pressing the sack 2 against the first right claw 76 and the first left claw 116 (see FIG. 6). As a result, the sack 2 moves upward relative to the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114, and moves away from the second right claw 78 and the second left claw 118 (see FIG. 6). Clearances are formed between the sack 2 and the second right claw 78 and between the sack 2 and the second left claw 118. Furthermore, due to the rotation of the first right pressing member 80, the second right pressing member 82, the first left pressing member 120, and the second left pressing member 122, the sack 2 comes into contact in the front-to-rear direction with the first contact portion 94 of the first right pressing member 80, the first contact portion 100 of the second right pressing member 82, the first contact portion 100 of the first left pressing member 120, and the first contact portion 94 of the second left pressing member 122. As a result, the sack 2 is sandwiched between the first contact portion 94 of the first right pressing member 80 and the first contact portion 100 of the second right pressing member 82, and between the first contact portion 100 of the first left pressing member 120 and the first contact portion 94 of the second left pressing member 122. Thus, the sack 2 is positioned relative to the robot hand 44 in the front-to-rear and up-down directions. Furthermore, in the positioning step, a step of positioning the sack 2 in the front-to-back direction relative to the robot hand 44 and a step of positioning the sack 2 in the up-down direction relative to the robot hand 44 are simultaneously performed. By performing the positioning step, it is possible to prevent the sack 2 from falling off the robot hand 44.Furthermore, the time required for positioning can be shortened compared to a configuration in which the process of positioning the sack 2 in the front-to-back direction relative to the robot hand 44 and the process of positioning the sack 2 in the up-to-down direction relative to the robot hand 44 are performed separately. Furthermore, rattling of the sack 2 in the front-to-back direction and up-to-down directions can be suppressed. Furthermore, movement of the sack 2 in the up-to-down direction and front-to-back directions while the robot hand 44 is operating can be suppressed. This makes it possible to suppress deviations in the position of the sack 2 in the up-to-down direction and front-to-back directions relative to the robot hand 44.

[0062] As shown in FIG. 11 , in the second gripping step after the positioning step, the right hand arm 70 and the left hand arm 110 move slightly closer to each other. As a result, the sack 2 is gripped with a second gripping force that is greater than the first gripping force used in the first gripping step. This grips the sack 2 in the left-right direction relative to the robot hand 44 with the second gripping force, preventing the sack 2 from wobbling left-right. This also effectively prevents the sack 2 from moving forward and backward and up and down while the robot hand 44 is operating. This effectively prevents the sack 2 from shifting out of position relative to the robot hand 44 in the forward and backward and up and down directions. In this embodiment, the contact members (e.g., gripping members 72, 74, right claws 76, 78, and pressing members 80, 82) that contact the sack 2 are made of ceramics. This allows the robot hand 44 to grip the high-temperature sack 2 after it has been transported from the heat treatment furnace 12. Furthermore, in a configuration in which the abutting member is made by coating a metal member with ceramic, the ceramic may peel off from the metal material, but in the abutting member of this embodiment, peeling does not occur, thereby preventing a decrease in the heat resistance and corrosion resistance of the abutting member.

[0063] As shown in Fig. 15, in the first moving step after the second gripping step, the robot arm 42 (see Fig. 2) operates and the robot hand 44 moves, thereby moving the sack 2 to the collection container 34. Next, as shown in Fig. 8, the shutter 160 moves from the closed position to the open position, and the sack detection sensor 162 emits a laser. When the control device 18 (see Fig. 2) detects that the sack detection sensor 162 has received the laser within a predetermined period, the shutter 160 moves from the open position to the closed position. Thereafter, the first reversing step is executed.

[0064] 15, in the first inversion step, the robot arm 42 (see FIG. 2) operates to rotate the robot hand 44 180 degrees about the axis AX6 (see FIG. 2), thereby inverting the sack 2 above the collection container 34. With the opening of the sack 2 facing downward, the objects 4 inside the sack 2 are collected into the collection container 34. Furthermore, since the length in the left-right direction of the first right claw 76 protruding from the left wall 70b is shorter than the length of the second right claw 78 protruding from the left wall 70b, and the length in the left-right direction of the first left claw 116 protruding from the right wall 110b is shorter than the length of the second left claw 118 protruding from the right wall 110b, it is possible to prevent the objects 4 from landing on the first right claw 76 and the first left claw 116.

[0065] In the second inversion process after the first inversion process, the robot arm 42 (see FIG. 2) operates to rotate the robot hand 44 180 degrees around the axis AX6 (see FIG. 2), thereby inverting the sagger 2 above the collection container 34. As a result, the opening of the sagger 2 faces upward. The direction in which the robot hand 44 rotates in the second inversion process is opposite to the direction in which the robot hand 44 rotates in the first inversion process. Next, as shown in FIG. 8, the shutter 160 moves from the closed position to the open position, and the sagger detection sensor 162 emits a laser. When the control device 18 (see FIG. 2) detects that the sagger detection sensor 162 has received the laser within a predetermined period, the shutter 160 moves from the open position to the closed position. Thereafter, the second movement process is executed.

[0066] 16, in the second moving step, the robot arm 42 (see FIG. 2) operates and the robot hand 44 moves, thereby moving the sack 2 to the base plate 8. Note that the movement of the robot hand 44 may also move the sack 2 to a location other than the base plate 8, for example, to a lifter disposed at one end of a transport conveyor that transports the sack 2 to the inlet 20.

[0067] In the positioning release step after the second movement step, the right hand arm 70 and the left hand arm 110 move slightly away from each other. As a result, the sack 2 is gripped by the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114 with the first gripping force. This releases the left-right positioning of the sack 2 relative to the robot hand 44. Next, as shown in FIG. 5 , the drive devices 130, 132 operate simultaneously, causing the link unit 134 to simultaneously operate the first right pressing member 80 and the second right pressing member 82, and the link unit 136 to simultaneously operate the first left pressing member 120 and the second left pressing member 122. As shown in Figure 16, the first right pressing member 80, the second right pressing member 82, the first left pressing member 120 (see Figure 6), and the second left pressing member 122 (see Figure 6) simultaneously rotate from the first position to the second position. This releases the force pressing the sack 2 toward the first right claw 76 and the first left claw 116 by the first right pressing member 80, the second right pressing member 82, the first left pressing member 120, and the second left pressing member 122. The sack 2 is held by the holding members 72, 74, 112, and 114 with a first holding force. If the first holding force is set to a force smaller than the weight of the sack 2, the sack 2 will move downward due to its own weight. As a result, the sack 2 is released from the first right claw 76 and the first left claw 116 and placed on the second right claw 78 and the second left claw 118 (see FIG. 6). This releases the positioning of the sack 2 in the front-to-back and up-to-down directions relative to the robot hand 44. When the first gripping force is set to a force greater than the weight of the sack 2, the sack 2 is held in a position where it abuts against the first right claw 76 and the first left claw 116 without being released from the first right claw 76 and the first left claw 116.

[0068] 17, in the lowering step after the positioning release step, the robot arm 42 (see FIG. 2) operates and the robot hand 44 moves downward. As a result, the sagger 2 is lowered and placed on the spacer 6 on the base plate 8.

[0069] In the grip releasing step after the lowering step, the right hand arm 70 and the left hand arm 110 move further away from each other. As a result, the sack 2 moves away from the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114. As a result, the grip of the sack 2 by the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114 is released. In addition, the first right claw 76 and the first left claw 116 (see FIG. 6) come out of the notch 2a of the sack 2, and the second right claw 78 and the second left claw 118 (see FIG. 6) come out from between the sack 2 and the base plate 8.

[0070] (effect) In the gripping method of the above embodiment, first, the sack 2 is gripped by the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114. Next, the sack 2 is pressed against the first right claw 76 and the first left claw 116 by the first right pressing member 80, the second right pressing member 82, the first left pressing member 120, and the second left pressing member 122. As a result, the sack 2 moves upward relative to the first right gripping member 72, the second right gripping member 74, the first left gripping member 112, and the second left gripping member 114, and is positioned at a predetermined position. As a result, it is possible to prevent the sack 2 from rattling in the up and down direction.

[0071] (Correspondence) The first right gripping member 72 and the first left gripping member 112 are an example of a "pair of gripping members." The second right gripping member 74 and the second left gripping member 114 are an example of a "pair of gripping members." The first right claw 76 and the first left claw 116 are an example of a "first claw." The second right claw 78 and the second left claw 118 are an example of a "second claw."

[0072] (Second Example) The second embodiment will be described by focusing on the differences from the first embodiment. As shown in Fig. 18, in the second embodiment, the right hand arm 54 includes a first right pressing member 280, a second right pressing member 282, a third right pressing member 284, and a fourth right pressing member 286, instead of the first right pressing member 80 and the second right pressing member 82 of the first embodiment.

[0073] The first right pressing member 280, the second right pressing member 282, the third right pressing member 284, and the fourth right pressing member 286 are attached to the left wall 70b of the right hand arm 70. The first right pressing member 280 and the second right pressing member 282 are arranged forward of the first right gripping member 72 (see FIG. 4), the second right gripping member 74 (see FIG. 4), the first right claw 76, and the second right claw 78. The third right pressing member 284 and the fourth right pressing member 286 are arranged rearward of the first right gripping member 72, the second right gripping member 74, the first right claw 76, and the second right claw 78. In the front-to-rear direction, the third right pressing member 284 and the fourth right pressing member 286 are arranged between the first right pressing member 280 and the second right pressing member 282. The first right pressing member 280 and the fourth right pressing member 286 are movable in the front-rear direction, while the second right pressing member 282 and the third right pressing member 284 are movable in the up-down direction.

[0074] 19 , the left hand arm portion 56 includes a first left pressing member 290, a second left pressing member 292, a third left pressing member 294, and a fourth left pressing member 296, instead of the first left pressing member 120 and the second left pressing member 122 of the first embodiment. The first left pressing member 290, the second left pressing member 292, the third left pressing member 294, and the fourth left pressing member 296 are symmetrical with the first right pressing member 280, the second right pressing member 282, the third right pressing member 284, and the fourth right pressing member 286, respectively, with respect to the imaginary plane P1. The first left pressing member 290, the second left pressing member 292, the third left pressing member 294, and the fourth left pressing member 296 are attached to the right wall 110b of the left hand arm 110. The first left pressing member 290 and the fourth left pressing member 296 are movable in the front-rear direction, while the second left pressing member 292 and the third left pressing member 294 are movable in the up-down direction.

[0075] As shown in FIG. 20, in the positioning step of the second embodiment, first, the first right pressing member 280 and the fourth right pressing member 286 move toward each other, and simultaneously, the first left pressing member 290 (see FIG. 19) and the fourth left pressing member 296 (see FIG. 19) move toward each other. As a result, the sack 2 is sandwiched between the first right pressing member 280 and the fourth right pressing member 286, and between the first left pressing member 290 and the fourth left pressing member 296. Therefore, the sack 2 is positioned in the front-to-rear direction relative to the robot hand 44. Next, as shown in FIG. 21, the second right pressing member 282, the third right pressing member 284, the second left pressing member 292 (see FIG. 19), and the third left pressing member 294 (see FIG. 19) move upward simultaneously. As a result, the second right pressing member 282, the third right pressing member 284, the second left pressing member 292, and the third left pressing member 294 press the sack 2 against the first right claw 76 and the first left claw 116 (see FIG. 19). Thus, the sack 2 is positioned in the up-down direction relative to the robot hand 44.

[0076] As shown in Figure 18, in the positioning release step of the second embodiment, the second right pressing member 282, the third right pressing member 284, the second left pressing member 292, and the third left pressing member 294 move downward simultaneously. As a result, the sack 2 is placed on the second right claw 78 and the second left claw 118 (see Figure 6). Furthermore, the first right pressing member 280 and the fourth right pressing member 286 move away from each other, and at the same time, the first left pressing member 290 and the fourth left pressing member 296 move away from each other. As a result, the sack 2 moves away from the first right pressing member 280, the fourth right pressing member 286, the first left pressing member 290, and the fourth left pressing member 296. Therefore, the positioning of the sack 2 relative to the robot hand 44 in the front-to-rear and up-down directions is released.

[0077] (Variation) In one embodiment, the conveying device 14 may include a plurality of rollers instead of the guide member 28 and the pusher 30. In this configuration, both ends of each of the plurality of rollers are rotatably supported by the heat treatment furnace 12. As the plurality of rollers rotate, the base plate 8 is conveyed on the plurality of rollers. Also, a plurality of saggers 2 may be placed on the base plate 8 in a vertically stacked state, or only one sagger 2 may be placed on the base plate 8. Furthermore, the sagger 2 may be placed directly on the rollers without using the base plate 8. In this configuration, the heat treatment system 10 may include a lifting device that separates the sagger 2 from the rollers. The robot hand 44 grasps the sagger 2 after the lifting device separates the sagger 2 from the rollers (i.e., after a gap is formed between the sagger 2 and the rollers).

[0078] In one embodiment, the right hand arm 54 may include only one of the first right gripping member 72 and the second right gripping member 74, or may include one or more gripping members in addition to the first right gripping member 72 and the second right gripping member 74. Additionally, the left hand arm 56 may include only one of the first left gripping member 112 and the second left gripping member 114, or may include one or more gripping members in addition to the first left gripping member 112 and the second left gripping member 114.

[0079] In one embodiment, in the positioning step, the first right pressing member 80, the second right pressing member 82, the first left pressing member 120, and the second left pressing member 122 may press the sagger 2 against the second right claw 78 and the second left claw 118. In this configuration, the sagger 2 is pressed downward.

[0080] In one embodiment, the step of positioning the sagger 2 in the front-to-rear direction relative to the robot hand 44 may not be performed in the positioning step.

[0081] In one embodiment, the first opening 86 and the second opening 88 may be arranged on a wall other than the rear wall 70a of the right hand arm 70 (or a wall other than the rear wall 110a of the left hand arm 110). The first opening 86 and the second opening 88 may be spaced apart in the left-right or front-rear direction. Furthermore, the wall of the right hand arm 70 (or the wall of the left hand arm 110) on which the first opening 86 is arranged may be different from the wall of the right hand arm 70 (or the wall of the left hand arm 110) on which the second opening 88 is arranged. For example, the first opening 86 may be arranged on the rear wall 70a of the right hand arm 70 (or the rear wall 110a of the left hand arm 110), and the second opening 88 may be arranged on the front wall of the right hand arm 70 (or the front wall of the left hand arm 110). This prevents a fluid from shortcutting from the first opening 86 to the second opening 88.

[0082] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Furthermore, the technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings simultaneously achieves multiple objectives, and achieving one of those objectives itself has technical utility. [Explanation of symbols]

[0083] 2: Sack 4: Object to be treated 10: Heat treatment system 12: Heat treatment furnace 16: Robot 34: Collection container 42: Robot arm 44: Robot Hand 48: Base part 50: Mounting material 52: Heat insulating material 54: Right hand arm 56: Left hand arm 70: Right hand arm 70a: Back wall 70b:Left wall 72: 1st right gripping member 74:Second right gripping member 76: First right claw 78: Second right claw 80: First right pressing member 82: Second right pressing member 86: First opening 88: Second opening 90: Interior space 94: 1st contact part 96:Second contact part 100: 1st contact part 102:Second contact part 110: Left hand arm 110a: Back wall 110b: Right wall 112: First left gripping member 114: Second left gripping member 116: 1st left claw 118: 2nd left claw 120: First left pressing member 122: Second left pressing member 134, 136: Link unit 150: Cooling mechanism 152: Feeding device 280: First right pressing member 282: Second right pressing member 284: Third right pressing member 286: Fourth right pressing member 290: First left pressing member 292: Second left pressing member 294: Third left pressing member 296: Fourth left pressing member AX10, AX11, AX12, AX13: Rotating axis

Claims

1. A gripping method performed by a robot that grips a sagger carried out from a heat treatment furnace, comprising: The robot includes a pair of hand arms that are movable in the left-right direction, The pair of hand arm portions are provided with a pair of gripping members and a pressing member, a step of gripping the sagger from the left and right directions with the pair of gripping members; a step of abutting the pressing member against the sagger held by the pair of gripping members, thereby moving the sagger in an up-down direction perpendicular to the left-right direction relative to the gripping members, thereby positioning the sagger at a predetermined position.

2. The pair of hand arm portions are provided with first claws, The method further includes the step of positioning the first claw on an upper side or a lower side of the sagger, The gripping method according to claim 1 , wherein the step of positioning the sagger in the vertical direction is performed by pressing the sagger against the first jaw with the pressing member.

3. The pair of hand arm portions are provided with second claws, The method further includes a step of arranging the second claw on the upper side or the lower side of the sagger where the first claw is not arranged, The gripping method according to claim 2 , wherein the step of disposing the first claw and the step of disposing the second claw dispose the sagger between the first claw and the second claw.

4. The method further includes a step of lifting the sagger held by the pair of gripping members after placing the sagger between the first claw and the second claw, The gripping method according to claim 3 , wherein the step of vertically positioning is performed after the step of lifting the sagger.

5. 5. The gripping method according to claim 1, further comprising a step of positioning the sagger gripped by the pair of gripping members in a front-to-rear direction perpendicular to the left-to-right direction and the up-to-down direction using the pressing member.

6. The gripping method according to claim 5 , wherein the step of positioning in the up-down direction and the step of positioning in the front-rear direction are performed simultaneously.

7. a step of moving the sagger held by the pair of gripping members to a collection container after the step of positioning in the vertical direction; The gripping method according to claim 1 , further comprising the step of inverting the sagger gripped by the pair of gripping members above the collection container after the sagger has moved to the collection container.

8. 5. The gripping method according to claim 1, further comprising, after the step of positioning in the vertical direction, a step of gripping the sagger with the pair of gripping members using a second gripping force that is greater than a first gripping force with which the pair of gripping members grip the sagger.

Images