Work device and plate holding element

Abstract

A working device of the present disclosure comprises a plate-holding element that holds a plate, a table on which the plate-holding element is placed, and a control device. The plate-holding element has a plate-supporting surface on which the plate is placed, a contact surface opposite the plate-supporting surface configured to come into contact with the table when the plate-holding element is placed on the table, a suction port configured to hold the plate by suction, the suction port being located on the plate-supporting surface, a connecting port connected to the suction port and open to an opposite side of the plate-supporting surface, and a holding section configured to be held by a conveyor box, the table having a holding element placement surface on which the plate-holding element is placed.and a vacuum supply port configured to supply a vacuum to the plate holder, the vacuum supply port being located at a point that communicates with the connection port in a state where the plate holder is placed on the table. The control device performs an exchange operation for the holder, which includes an unloading operation for the holder and a loading operation for the holder.

Description

Technical field The present description discloses a working device and a plate holding element. State of the art A working device is known that performs work on a plate and in which a holding element for the plate is interchangeable. For example, in a working device disclosed in patent literature 1, a control device performs an unloading process for the holding element and a loading process for the holding element in order to replace a plate holding element. During the loading process of the holding element, the control device transports a conveyor box, which holds the plate holding element to be replaced, to a position above a table, releases the plate holding element from the conveyor box, places the plate holding element on the table, and then transports the conveyor box. The unloading process of the holding element is carried out by performing a process that is the opposite of the loading process of the holding element. Citation list Patent literature Patent literature 1: WO 2022 / 234650 Summary of the invention Technical task One could consider providing a suction port on the top of the plate holder so that the plate can be held and secured by suction while the plate holder supports the plate from below. However, using such a plate holder requires an additional step to create a vacuum at the suction port, such as connecting a hose to create a vacuum at the exchange device, and this step is time-consuming. The present disclosure was made to solve the problem described above, and its main objective is to facilitate the connection of a vacuum supply path to a plate when the plate is installed in a working device. Solution to the problem The present disclosure provides for the following measures to achieve the main objective described above. A working device of the present disclosure is a working device for performing work on a plate, wherein the working device comprises: a plate holding element configured to hold the plate; a table on which the plate holding element is placed; a box conveying section configured to convey a conveying box capable of holding the plate; an attachment and removal section configured to enable the holding and removal of the plate by the conveying box; and a control device configured to control the box conveying section and the attachment and removal section, wherein the plate holding element comprises a plate support surface on which the plate is placed, a contact surface opposite the plate support surface, the contact surface being configured to come into contact with the table when the plate holding element is placed on the table, and a suction port.which is configured to hold the plate by suction, wherein the suction port is located on the plate support surface, a connecting port that communicates with the suction port and is open to an opposite side of the plate support surface, and a holding section configured to be held by the conveying box, wherein the table comprises a holding element placement surface for the holding element on which the plate holding element is placed, and a vacuum supply port configured to supply a vacuum to the plate, wherein the vacuum supply port is located at a point that communicates with the connecting port in a state in which the plate is placed on the table, and the control device causes the box conveying section and the attachment and removal section to perform an exchange operation for the holding element, which includes an unloading operation for the holding element.in which the conveyor box is driven in, the plate placed on the table is attached to the driven conveyor box as the unloading target, so that the plate is held, and the conveyor box is driven out after attachment, and a loading process for the holding element in which the holding element is loaded into the conveyor box as the loading target, the holding element is removed from the conveyor box as the loading target by releasing the holding of the holding element, the removed holding element is placed on the table and the conveyor box is conveyed further after removal. In this work device, the plate holder has a holding section and can be held by the conveyor box. The control device can control the box conveyor section and the loading and unloading section, and perform a holder exchange operation that includes unloading and loading the holder using the conveyor box. Furthermore, the plate holder has a contact surface opposite the plate support surface, configured to make contact with the table when the plate holder is placed on the table, and a connecting port that connects to the suction port, configured to hold the plate by suction, and which is open on one side opposite the plate support surface.The table on which the plate holder is placed has a vacuum supply port configured to supply a vacuum to the plate holder. The vacuum supply port is located in a position that communicates with the plate holder's connection port when the plate holder is in place. Therefore, placing the loaded plate holder on the table creates a state where a vacuum can be supplied to the vacuum port via the connection port from the vacuum supply port. Consequently, it is not necessary to perform the process of connecting the vacuum supply port to the plate holder as a separate process from the process of placing the plate holder on the table.As a result of the above, it is easy to connect the vacuum supply path to the plate holding element in this working device when the plate holding element is installed in the working device. Brief description of the characters Fig. 1 is a schematic configuration diagram of the working device 10 of the present disclosure. Fig. 2 is a perspective view illustrating an internal configuration of the working device 10. Fig. 3 is a side view illustrating the internal configuration of the working device 10. Fig. 4 is a block diagram illustrating an electrical connection relationship of the working device 10. Fig. 5A is a perspective view of the plate-holding element 90 seen from the top. Fig. 5B is a perspective view of the plate-holding element 90 seen from the bottom. Fig. 6 is a perspective view of the table 36 seen from the top. Fig. 7A is a schematic cross-sectional view illustrating a state immediately before the plate-holding element 90 is placed on the table 36.Figure 7B is a schematic cross-sectional view showing a state in which the plate-holding element 90 is placed on the table 36. Figure 8 is an external perspective view of the conveyor box 80. Figure 9 is an external perspective view of the conveyor box 80 to which the plate-holding element 90 is attached. Figure 10 is a schematic configuration diagram of the arm element 82. Figure 11 is a schematic configuration diagram of the pusher 24. Figure 12 is a partially enlarged view of the pusher 24. Figure 13 is a view showing a process for removing the plate-holding element 90 from the conveyor box 80. Figure 14 is a view illustrating a process for removing the plate-holding element 90 from the conveyor box 80. Figure 15 is a view illustrating a process for removing the plate-holding element 90 from the conveyor box 80. Fig. 16 is a flowchart illustrating an example of a loading process for retaining elements.Fig. 17 is a perspective view of the plate-holding element 190 of a modified embodiment, seen from above. Fig. 18 is an external perspective view of the conveyor box 180 of a modified embodiment. Fig. 19A is a view showing a state in which the plate-holding element 190 is being loaded and unloaded by the conveyor box 180. Fig. 19B is a view showing a state in which the plate-holding element 190 is being loaded and unloaded by the conveyor box 180. Fig. 19C is a view showing a state in which the plate-holding element 190 is being loaded and unloaded by the conveyor box 180. Description of the embodiments Next, embodiments of the present disclosure will be described with reference to the figures. Fig. 1 is a schematic configuration diagram of the working device 10 of the present disclosure. Fig. 2 is a perspective view illustrating an internal configuration of the working device 10. Fig. 3 is a side view illustrating an internal configuration of the working device 10. Fig. 4 is a block diagram illustrating an electrical connection relationship of the working device. In Figs. 1, 2 to 3, the left-right direction is designated as the X-axis, the front-back direction as the Y-axis, and the top-bottom direction as the Z-axis. The working device 10 performs predetermined operations on the plate S, which is held by the plate holder 90. In the present embodiment, the working device 10 is configured as a printing device that uses the squeegee 22 as its predetermined operation to press solder paste onto the screen mask M into the pattern holes P1 and P2 formed in the screen mask M, thereby applying (printing) the solder paste onto the underlying plate S via the pattern holes P1 and P2. The working device 10, in combination with an assembly device that mounts an electronic component onto the plate S, onto which solder paste has been printed, forms a component assembly system. When changing to a different type of plate S for printing, the working device 10 is also capable of automatically exchanging the screen mask M or automatically exchanging the plate holder 90 using a conveyor box 80. As shown in Figures 1, 2, 3 to 4, the work device 10 comprises a work device main body 11, an exchange device 60, a storage rack 70, and a control unit 100. The work device main body 11 includes a head device 20 with a head 21, a support rail 29 that supports the screen mask M and the conveyor box 80, a first and a second plate conveying and holding device 30 and 40 that transport and support the plate S over two tracks, a camera device 50, and a pressure reducing device 65. Furthermore, the work device 10 also includes a control panel, which is installed in front of the work device main body 11, displays various information, and allows a worker to perform various input operations. The head assembly 20 is installed on an upper stage of the main body of the working device 11. As shown in Fig. 1, the head assembly 20 comprises a head 21 and a head movement device 26, which moves the head 21 in the front-to-back direction (Y-axis direction), which is a printing direction. The head movement device 26 comprises a Y-axis slider 27, which moves along a guide rail 28 extending in the front-to-back direction, and a motor for driving the Y-axis slider 27. The head 21 comprises a doctor blade 22, a doctor blade lifting device 23 for raising and lowering the doctor blade 22, for example using an air cylinder, a pusher 24, and a pusher lifting device 25 for raising and lowering the pusher 24, for example using an air cylinder. The squeegee 22 is a plate-shaped element that extends orthogonally to the printing direction in the left-right direction (X-axis direction).The pusher 24 is lowered by the pusher lifting device 25 and moves back and forth by the head movement device 26 while projecting downwards, thereby pushing and transporting the screen mask M and the conveyor box 80 back and forth on the support rail 29. Furthermore, when replacing the plate holder 90 using the conveyor box 80, the pusher 24 is also used to collect the plate holder 90 on the tables 36 and 46 and transport it to the conveyor box 80, which has been placed on the support rail 29; or to remove the plate holder 90 from the conveyor box 80, which has been placed on the support rail 29, while holding it in place, and to place the plate holder 90 on the tables 36 and 46. The screen mask M is a thin metal plate and is attached to a rectangular frame body F with a predetermined tension. Pattern holes P1 and P2 are formed in the screen mask M for printing solder onto the plate S, which is conveyed and held by the first and second plate conveying and holding devices 30 and 40. As shown in Fig. 3, the support rails 29 are a pair of left and right rails extending in the front-to-back direction (Y-axis direction) and are installed between the head assembly 20 and the first and second plate conveyor and holding devices 30 and 40. The support rails 29 support the screen mask M and the conveyor box 80 in a horizontal position and guide the screen mask M and the conveyor box 80, which are pushed by the pusher 24, so that they move longitudinally. The first and second plate conveying and holding devices 30 and 40 convey and hold the plate S and bring the held plate S into contact with the screen mask M on the support rails 29 and away from it again. As shown in Figs. 2, 3 to 4, the first and second plate conveying and holding devices 30 and 40 comprise conveying devices 31 and 41, conveying interval changing devices 34 and 44, conveying lifting and lowering devices 35 and 45, tables 36 and 46, and holding element lifting and lowering devices 37 and 47. The conveying devices 31 and 41 each comprise conveyor belts arranged on a pair of front and rear side frames 33s and 43s, respectively, and motors that drive the conveyor belts to rotate them. A pair of side frames 33s and 43s is mounted on base frames 33b and 43b, and plate guides 32 and 42 are arranged at the upper end sections of the pair of side frames 33s and 43s.The conveyor interval changing devices 34 and 44 change (adjust) the distance between the conveyor belts by moving one or both pairs of side frames 33s and 43s closer to or further apart from each other. This allows the first and second plate conveying and holding devices 30 and 40 to convey and support plates S of different sizes. Conveyor lifting and lowering devices 35 and 45 raise and lower conveying devices 31 and 41 (conveyor belts) by raising and lowering support columns that support the base frames 33b and 43b. The tables 36 and 46 are support tables on which the plate holding element 90 can be placed. The holding element lifting and lowering devices 37 and 47 raise and lower the plate holding elements 90 placed on the tables 36 and 46 by raising and lowering the support columns that support the tables 36 and 46. The plate holding element 90 holds the plate S by suction and secures the plate S while supporting it from below. As shown in Fig. 5A, the plate holding element 90 includes a plate support surface 91 on which the plate S is placed. The plate support surface 91 is at least part of the top surface of the plate holding element 90. When the plate S is placed on the plate holding element 90, the underside of the plate S comes into contact with the plate support surface 91. The plate support surface 91 may, for example, have one or more recessed sections (not shown) to prevent interference between components present on the underside of the plate S and the plate holding element 90. The plate support surface 91 is provided with a suction port 91a to hold the placed plate S by suction.One or more suction ports 91a are arranged, wherein in the present embodiment eight suction ports 91a are arranged. As shown in Fig. 5B, the plate holding element 90 comprises a rear surface 92 opposite the plate support surface 91, a holding section 93, a first leg section 94a, and a second leg section 94b. The holding section 93 is a section held by the conveyor box 80, which holds the plate holding element 90. The holding section 93 has a first edge section 93a on an outer edge section of the rear surface 92, a pair of first pin elements 93c (first engagement sections) arranged on the first edge section 93a, a second edge section 93b opposite the first edge section 93a on the outer edge section of the rear surface 92, and a pair of second pin elements 93d (second engagement sections) arranged on the second edge section 93b.The first edge section 93a (in particular, a section of the first edge section 93a between a pair of first pin elements 93c) is supported by a first arm element 82a, which is a first of a pair of arm elements 82 of the conveyor box 80. The pair of first pin elements 93c engages with the first arm element 82a. The second edge section 93b (in particular, a section of the second edge section 93b between a pair of second pin elements 93d) is supported by a second arm element 82b, which is a second of a pair of arm elements 82 of the conveyor box 80. The pair of second pin elements 93d engages with the second arm element 82b. The first leg section 94a is an element attached to an edge section (also referred to as the third edge section) adjacent to (orthogonal to) the first edge section 93a on the outer edge section of the back surface 92, such that it projects downwards from the back surface 92 (i.e., in a direction opposite to the plate bearing surface 91). The second leg section 94b is an element attached to an edge section (also referred to as the fourth edge section) opposite the third edge section on the outer edge of the back surface 92, such that it projects downwards from the back surface 92 (i.e., in a direction opposite to the plate bearing surface 91). At least a portion of the underside of the first leg section 94a serves as a contact surface 95a, and at least a portion of the second leg section 94b serves as a contact surface 95b.When the plate-holding element 90 is placed on the tables 36 and 46, the tables 36 and 46 and the contact surfaces 95a and 95b come into contact with each other. Since the contact surfaces 95a and 95b are located on the undersides of the first leg section 94a and the second leg section 94b, which are designed to project downwards from the back 92, the back 92 with the first edge section 93a and the second edge section 93b is located on a surface opposite the plate support surface 91 and at a position higher than the contact surfaces 95a and 95b (i.e., at a position closer to the plate support surface 91 than the contact surfaces 95a and 95b).Even if the plate contact surfaces 95a and 95b of the plate holding element 90 are in contact with the tables 36 and 46, the first edge section 93a and the second edge section 93b are not in contact with the tables 36 and 46, so that the arm element 82 of the conveyor box 80 can be inserted below the first edge section 93a and the second edge section 93b. Furthermore, the plate holding element 90 has a connecting port 96, positioning holes 97a and 97b, and magnets 98a and 98b, which are arranged on the underside of the first leg section 94a. The connecting port 96 is located near the center of the underside of the first leg section 94a and is open towards the opposite side of the plate support surface 91. The connecting port 96 is connected to the suction port 91a via a connecting channel (not shown) located within the plate holding element 90. A seal 96a is arranged as a sealing element at a location corresponding to the connecting port 96. The seal 96a is an elastic element and is made, for example, of rubber or plastic.The seal 96a is arranged in a recessed section located in part of the underside of the first leg section 94a, such that the underside of the seal 96a (the surface opposite the plate support surface 91) is essentially at the same level as the contact surface 95a (the underside of the seal 96a and the contact surface 95a are essentially flush with each other). It is advantageous to arrange the seal 96a such that its underside protrudes slightly below the contact surface 95a. The positioning holes 97a and 97b are recessed holes extending from the contact surface 95a towards the plate support surface 91 and are arranged on both sides of the connecting port 96, one on each side, so that they enclose the connecting port 96 between them.The positions and sizes of the positioning holes 97a and 97b are determined such that the positioning pins 36d and 36e of the tables 36 and 46 are inserted into the positioning holes 97a and 97b when the plate holding element 90 is placed on the tables 36 and 46. The magnets 98a and 98b are permanent magnets arranged on the contact surface 95a and on both sides of the connecting port 96 and the positioning holes 97a and 97b, one on each side, so that they enclose the connecting port 96 and the positioning holes 97a and 97b between them.The magnets 98a and 98b are arranged in recesses located in the first leg section 94a, and the undersides of the magnets 98a and 98b (the surface opposite the plate support surface 91) are essentially at the same level as the contact surface 95a (the undersides of the magnets 98a and 98b and the contact surface 95a are essentially flush with each other). Additionally, two first identification markings 99a are formed on the first leg section 94a. Furthermore, two second identification markings 99b are also formed on the second leg section 94b. The first and second identification markings 99a and 99b are used by the working device 10 to detect the position and size (width from front to back) of the plate holding element 90 when replacing the plate holding element 90. As shown in Fig. 6, the table 36 comprises a holding element placement surface 36a, a vacuum supply port 36b, positioning pins 36d and 36e, and a detection section 38. The holding element placement surface 36a is a surface on which the plate holding element 90 is placed. The holding element placement surface 36a is at least part of the top surface of the table 36, and in the present embodiment, the entire top surface serves as the holding element placement surface 36a. Vacuum is applied to the plate holding element 90, which is placed on the table 36, via the vacuum supply port 36b. The vacuum supply port 36b is connected via a through-hole (see Fig. 7A and Fig. 7B) inside the table 36 to the interior of a tube 36c, which is arranged on the underside of the table 36. The pipe 36c is connected to a pressure reducing device 65 (see Fig. 4), for example a vacuum pump.Therefore, a vacuum can be supplied from the pressure reducing device 65 via the tube 36c and the vacuum supply port 36b to the connecting port 96 of the plate holding element 90. When the vacuum is supplied to the connecting port 96, it is also supplied to the suction port 91a, and the plate S placed on the plate support surface 91 is held and fixed by suction. The pressure reducing device 65 can be an element (part of the working device 10) arranged within the working device 10 or a device installed separately from the working device 10. The positioning pins 36d and 36e are pins arranged to project upwards from the holding element placement surface 36a and are located on the left and right sides of the vacuum supply port 36b, one on each side, so that they clamp the vacuum supply port 36b between them.The positioning pins 36d and 36e are inserted into the positioning holes 97a and 97b when the plate-holding element 90 is placed on the tables 36 and 46. The tip sections of the positioning pins 36d and 36e each have a tapered section whose diameter gradually decreases towards the tip. The sensing section 38 is a sensor for detecting the position of the plate-holding element 90 on the holding element placement surface 36a of the table 36. In the present embodiment, the sensing section 38 is a non-contact sensor, in particular a capacitive proximity sensor. The sensing section 38 has a sensing area directly above itself and detects whether an object (here, the plate-holding element 90) is located within the sensing area.The detection area of ​​the detection section 38 includes only the vicinity of the detection section 38, and the detection section 38 detects the presence of an object (here the plate holding element 90) when the contact surfaces 95a and 95b of the plate holding element 90 come so close to the holding element placement surface 36a that they come into contact with it. Fig. 7A is a schematic cross-sectional view showing the state immediately before the plate-holding element 90 is placed on the table 36. Fig. 7B is a schematic cross-sectional view showing the state in which the plate-holding element 90 is resting on the table 36. As shown in Fig. 7B, in this state, when the plate holding element 90 is placed at a predetermined position (for example, in an area marked by a dashed frame in Fig. 6) of the holding element placement surface 36a, the vacuum supply port 36b is opposite and connected to the connection port 96, the positioning pins 36d and 36e of the tables 36 and 46 are inserted into the positioning holes 97a and 97b, the plate holding element 90 (here in particular the contact surface 95a) is located directly above the detection section 38, and the magnets 98a and 98b point towards the holding element placement surface 36a.As described above, in a case where the underside of the seal 96a protrudes slightly below the contact surface 95a, the seal 96a is elastically deformed when the plate holder 90 is placed on the table 36, thereby sealing the space between the vacuum supply port 36b and the connection port 96 more reliably. Furthermore, the table 36 is made of a magnetic material such as iron. Since the magnets 98a and 98b of the plate holder 90 can attract the table 36 with magnetic force, it is possible to prevent the positioning pins 36d and 36e from protruding from the positioning holes 97a and 97b, thus sealing the space between the vacuum supply port 36b and the connection port 96 more reliably. Sections of the table 36 facing the magnets 98a and 98b when the plate holding element 90 is placed on the table 36 may be made of a magnetic material. Since the configuration of table 46 is identical to that of table 36, a detailed description is omitted. Similar to table 36, table 46 includes a holding element placement surface 36a, a vacuum supply port 36b, a tube 36c, positioning pins 36d and 36e, and the like. Furthermore, table 46 includes a detection section 48 (see Fig. 4), which is similar to detection section 38. As shown in Figures 1 and 2, the camera device 50 comprises a camera body 51 and a camera movement device 55, which moves the camera body 51 in the front-back and left-right directions (XY direction). The camera movement device 55 comprises an X-axis slider 56, a motor for driving the X-axis slider 56, a Y-axis slider 58, and a motor for driving the Y-axis slider 58. The Y-axis slider 58 is an elongated element that extends in the left-right direction and bridges a pair of left and right Y-axis guide rails 59, moving back and forth along the Y-axis guide rails 59. The X-axis slider 56 moves left and right along the X-axis guide rail 57, which is arranged on the Y-axis slider 58.The main camera body 51 is attached to the X-axis slider 56 and has two image acquisition fields (upper reading section 52 and lower reading section 53) on its top and bottom surfaces. The camera device 50 uses the lower reading section 53 to capture an image of a mark formed on the top surface of the plate S, which is loaded and held by the first and second plate conveyor and holding devices 30 and 40, respectively, thus determining the position of the plate S. Furthermore, the camera device 50 uses the upper reading section 52 to capture an image of marks (first and second detection marks 99a and 99b) formed on the underside of a plate holding element 90, which, together with a conveyor box 80, has been loaded onto a support rail 29, thus determining the position and size (front-to-back width) of the plate holding element 90. The exchange device 60 accommodates the storage rack 70, in which exchange elements such as the screen mask M and the conveyor box 80 are stored, and transports the exchange elements between the storage rack 70 and the main body of the work device 11. The exchange device 60 comprises a left unit 61a, which is installed on the left side of the front of the main body of the work device 11, and a right unit 61b, which is installed on the right side of the front of the main body of the work device 11. The left unit 61a and the right unit 61b comprise a rack support element 62, which accommodates the storage rack 70 and holds one underside of the storage rack 70 from the left and right sides, and a rack lifting and lowering device 63, which raises and lowers the rack support element 62. The rack lifting and lowering device 63 comprises, for example, a combination of a ball screw mechanism and a motor or a linear motor.The storage rack 70, supported by the rack support element 62, is raised and lowered together with the rack support element 62 by the rack lifting and lowering device 63. Furthermore, each of the left unit 61a and the right unit 61b comprises a frame return and forward movement device 64, which moves a frame of the exchange device back and forth within the storage rack 70 from the left and right sides by means of belts, rollers or the like. The storage rack 70 has pairs of left and right support rails 71 arranged in several vertical steps and serves as a storage body that can hold the exchange element on each support rail 71. Additionally, opening sections 72 and 73 are provided on the main body of the work device 11 and on the front and rear of the storage rack 70. The exchange element is inserted and removed by a worker or similar person through the opening section 72 at the front and loaded and unloaded by the frame retraction and forward movement device 64 through the opening section 73 at the rear.In a state where the storage rack 70 is received by the exchange device 60, the frame return and forward movement device 64 conveys the exchange element, which is supported by the support rail 71 located substantially at the same height as the support rail 29 of the main body of the working device 11, through the rack lifting and lowering device 63 between the support rails 71 in several stages of the storage rack 70 to the main body of the working device 11. In addition, the frame return and forward movement device 64 guides the exchange element, supported by the support rail 29 of the main body of the working device 11, towards the support rail 71 of the storage rack 70, which is located substantially at the same height as the support rail 29.The storage rack 70 can be transported by the worker to the receiving position of the exchange device 60 or mounted on an automated guided vehicle (AGV) and automatically transported by the automated guided vehicle to the receiving position of the exchange device 60. The conveyor box 80 is a device for loading and unloading the plate holding element 90 and, as shown in Figures 8 and 9, the conveyor box 80 comprises a rectangular frame body 81 and a pair of arm elements 82 (first arm element 82a and second arm element 82b) which are attached to the frame body 81 such that their tips face each other and hold the plate holding element 90 from both sides. In the present embodiment, the conveyor box 80 comprises two pairs of arm elements 82 that hold the plate holding elements 90 and can transport the plate holding elements 90 used in the first and second plate conveying and holding devices 30 and 40 simultaneously. As shown in Fig. 10, each arm element 82 (first arm element 82a and second arm element 82b) comprises a base element 821, an arm plate 822, a retaining element 823, side plates 825, locking plates 826, and a locking block 827. The side plate 825 and the locking plate 826 on the front side are shown with dashed lines in Fig. 10 for clarity of the configuration. The base element 821 is attached to the frame body 81. A base end section of the arm plate 822 is rotatably mounted on the base element 821, and the retaining element 823 is rotatably attached to a tip section of the arm plate 822. Side plates 825 are arranged on both sides of the arm plate 822. A base end section of the side plate 825 is rotatably mounted by the base element 821, and the retaining element 823 is rotatably attached to a tip section of the side plate 825.Furthermore, the side plate 825 receives the preload force of a torsion coil 824, which is arranged on a rotating shaft on the side of the base element 821, and pushes the arm plate 822 upwards. In addition, the side plate 825 is brought into a substantially horizontal position by a stop formed on the base element 821 and holds the arm plate 822 in a substantially horizontal position. The retaining element 823 forms a tip section of the arm element 82 and holds the held section 93 of the plate retaining element 90. In particular, the retaining element 823 of the first arm element 82a supports the first edge section 93a of the held section 93 and engages in a pair of first pin elements 93c arranged on the first edge section 93a.Furthermore, the retaining element 823 of the second arm element 82b supports the second edge section 93b of the held plate 93 and engages in a pair of second pin elements 93d arranged on the second edge section 93b. Thus, the plate retaining element 90 is held from both sides by the pointed sections (retaining elements 823) of the pair of arm elements 82. The plate retaining element 90, held by the pair of arm elements 82, is released from the conveyor box 80 and placed on the tables 36 and 46 when the respective plates 822 of the pair of arm elements 82 are pressed downwards and spread apart over the tables 36 and 46. Locking plates 826 lock the arm plate 822 to prevent it from being forced downwards. The locking plates 826 are arranged on both sides of the arm plate 822, and the locking block 827 is mounted between the two locking plates 826 so that it is located below the arm plate 822. The locking plate 826 is rotatably attached at its base end to the base element 821 at a position that is eccentric with respect to a pivot shaft on the base end of the arm plate 822, and is biased towards the arm plate 822 by the preload force of the tension spring 828, which engages between the locking plate 826 and the arm plate 822 at a position on a tip relative to the base end. The locking block 827 engages in a notch 822c formed in a bottom surface of the arm plate 822 to lock the arm plate 822 so that the arm plate 822 cannot be pushed downwards.Furthermore, the tip sections of both locking plates 826 extend beyond the arm plate 822 when the locking block 827 engages in the notch 822c of the arm plate 822. In the arm element 82 configured in this way, the arm plate 822 is locked so that it cannot be pushed downwards, since the locking block 827 engages in the notch 822c of the arm plate 822 due to the preload force of the tension spring 828. Therefore, the arm element 82 (arm plate 822) is not pushed downwards even if an unintended force acts on the plate retaining element 90 or the arm plate 822, and release of the plate retaining element 90 is prevented. The locking of the locking plate 826 can be released by pressing down on the tip section of the locking plate 826 that projects beyond the arm plate 822. The release of the locking mechanism of the locking plate 826 and the downward pressing of the arm plate 822 are performed by a push button 24. As shown in Figs. 11 and 12, the push button 24 comprises pairs of front and rear push button plates 241, which are arranged on the left and right sides at a distance corresponding to the distance between a pair of arm elements 82, and a push button roller 242, which is arranged between each pair of front and rear push button plates 241. When the push button 24 is lowered by the push button lifting and lowering device 25 over the pair of arm elements 82, the lower end sections of the pair of push button plates 241 abut the tip sections of the locking plates 826, and the tip sections of the locking plates 826 are pressed downwards by the push button plates 241 (see Fig. 13 ).When the tip section of the locking plate 826 is pressed downwards, the locking block 827 is lowered and the engagement between the locking block 827 and the notch 822c of the arm plate 822 is released (see Fig. 14). This releases the locking mechanism of the arm plate 822. When the pusher 24 is lowered further, the pusher roller 242 abuts the arm plate 822, and the arm plate 822 is pressed downwards by the pusher roller 242 (see Fig. 15). This causes the two arm elements 82 to spread apart, and the plate retaining element 90, held by the two arm elements 82, is released from the arm elements 82.As described above, by raising and lowering the push button 24, which actuates the arm elements 82 (first arm element 82a and second arm element 82b) of the conveyor box 80, it is possible to switch between a holding position, in which the pair of arm elements 82 can hold the plate holding element 90 from both sides (a position in which the arm plate 822 is locked in a substantially horizontal position, as shown in Figs. 9 and 13), and a holding release position, in which the holding is released (a position in which the pair of arm elements 82 spreads further from the state shown in Fig. 15 to release the plate holding element 90 from the arm elements 82). Thus, the push button 24 holds and releases the plate holding element 90 through the conveyor box 80. The control device 100 is configured as a microprocessor, primarily comprising a CPU, and in addition to the CPU includes a ROM, RAM, a storage device 101, an input / output port, and the like. The control device 100 exchanges signals with the head device 20, the first and second plate conveyor and holding devices 30 and 40, the camera device 50, the exchange device 60, the pressure reduction device 65, and the like. Furthermore, the control device 100 is connected to a management device 200, which manages an entire work system, including the work device 10. The management device 200 maintains the progress status and other parameters of a line that includes the work device 10. The following describes the operation of the work device 10 configured as described above. In particular, the operation of the changeover for exchanging the screen mask M or the panel holder 90 is described. The changeover is performed by executing a mask unloading operation, a holder exchange operation, and a mask loading operation in that order in a state where the storage rack 70 is set in the exchange device 60. The holder exchange operation comprises a holder unloading operation and a holder loading operation, and the holder loading operation is performed after the holder unloading operation. The mask unloading process is a process for unloading the screen mask M, which is supported by the support rail 29 of the main body of the work device 11, and for storing the unloaded screen mask M in the storage rack 70. During the mask unloading process, the control device 100 controls the rack lifting and lowering device 63 so that the empty support rail 71 of the storage rack 70 is essentially at the same height as the support rail 29 of the main body of the work device 11. The control device 100 then controls the head movement device 26 so that the screen mask M, supported by the support rail 29, is pushed forward by the pusher 24 and unloaded from the main body of the work device 11. Finally, the control device 100 controls the frame return and forward movement device 64 so that the unloaded screen mask M is stored in the storage rack 70.Since the mask loading process is essentially performed by a process that is the opposite of the mask unloading process, its description is omitted here. The unloading process involves removing the conveyor box 80 from the storage rack 70, attaching the plate-holding element 90, which is placed on tables 36 and 46, to the removed conveyor box 80 as the unloading target, thus holding the plate-holding element 90 in place, and then returning the conveyor box 80 to the storage rack 70. The loading process involves loading the conveyor box 80, to which the plate-holding element 90 is attached as the loading target, from the storage rack 70, releasing the plate-holding element 90 as the loading target from the conveyor box 80 by releasing its mounting, placing the unloaded plate-holding element 90 onto tables 36 and 46, unloading the conveyor box 80 after releasing the plate-holding element 90, and storing the unloaded conveyor box 80 in the storage rack 70. Fig.Figure 16 is a flowchart illustrating an example of the charging process for the holding element performed by the control device 100. Since the holding element unloading process is essentially performed by a process that is the opposite of the holding element charging process, its description is omitted. During the holding element loading process, the control device 100 first performs a control action so that the conveyor box 80, holding two panel holding elements 90 which are exchange destinations (loading destinations), is transported to a position above the tables 36 and 46 of the first and second panel conveyor and holding devices 30 and 40 (step S100). Specifically, the control device 100 causes the rack lifting and lowering device 63 to raise the storage rack 70 until the support rail 71, which carries the conveyor box 80 to be loaded, is essentially at the same height as the support rail 29 of the main body of the work device 11. Subsequently, the control device 100 controls the frame return and forward movement device 64 so that the conveyor box 80 is moved out of the storage rack 70 to the support rail 29.Then the control device 100 controls the head movement device 26 so that the pusher 24 is lowered by the slide lifting and lowering device 25 and the conveyor box 80 is pushed backwards and loaded on the support rail 29 by the pusher 24. The control device 100 controls the camera device 50 such that the upper reading section 52 of the camera main body 51 reads the first and second recognition marks 99a and 99b, which are arranged on the plate holder 90 held by the loaded conveyor box 80 (step S110). Subsequently, the control device 100 detects the positions of the two plate holders 90 held by the conveyor box 80 based on the positions of the read first and second recognition marks 99a and 99b and corrects the position of the conveyor box 80 so that the two plate holders 90 are located directly above the tables 36 and 46 (step S120). That is, the control device 100 causes the head movement device 26 to push the conveyor box 80 forward or backward with the pusher 24, thereby fine-tuning the position of the conveyor box 80.By executing steps S100 and S120, the control device 100 adjusts the position of the conveyor box 80 so that the two plate holding elements 90 are located directly above a predetermined position (for example, within an area indicated by a dashed frame in Fig. 6) of the holding element placement surface 36a of the tables 36 and 46. Thus, the connecting port 96 and the positioning holes 97a and 97b of the two plate holding elements 90 are located directly above the vacuum supply port 36b and the positioning pins 36d and 36e of the tables 36 and 46. Next, the control device 100 causes the holding element lifting and lowering device 37 or 47 for the holding elements to raise the table 36 or 46 to the pressure height (step S130). Subsequently, the control device 100 controls the lifting and lowering device 25 for the pusher so that the pusher 24 is lowered directly above the raised table (step S140), and determines whether the detection section 38 or 48 has detected the placement of the plate holding element 90 on the holding element placement surface 36a of the table 36 or 46 (step S150). If the placement has not been detected, the control device 100 waits until a predetermined time has elapsed (step S160). The predetermined time is defined as a period of time resulting from the waiting time until the plate holding element 90 is released from the conveyor box 80 and placed on the table 36 or 46, plus a safety margin.As described above, when the pusher 24 is lowered, the two left and right pushers 241 initially strike the locking plates 826 of the corresponding arm elements 82 and press the locking plates 826 downwards, thereby releasing the locking mechanism of the arm plates 822. As the pusher 24 is lowered further, the left and right pusher rollers 242 strike the corresponding arm plates 822, press the arm plates 822 downwards, and thus spread the two arm elements 82 apart. In this way, the plate-holding element 90 is released from the two arm elements 82 and placed on the table. As described above, by simply lowering the pusher 24 directly above the pair of arm elements 82, the pair of arm elements 82 can be switched between the holding position and the holding-release position, and the plate-holding element 90 can be released from the conveyor box 80 and placed on the table.When the pair of arm elements 82 spread apart, the plate-holding element 90 is lowered from a position above the table 36 (or table 46) towards the holding element placement surface 36a, as shown in Fig. 7A. When the plate-holding element 90 is released from the pair of arm elements 82 and placed on the table, the state shown in Fig. 7B is reached. By placing the loaded plate-holding element 90 on the table 36 or 46, a vacuum can therefore be directed from the vacuum supply port 36b via the connecting port 96 to the suction port 91a. Since the positioning pins 36d and 36e of the tables 36 and 46 also have conical sections, the surfaces of the conical sections are inclined in relation to the top-bottom direction, thus serving as guides when the positioning pins 36d and 36e are inserted into the positioning holes 97a and 97b.Even if the positional relationship between the tables 36 and 46 and the lowered plate-holding element 90 deviates slightly from the correct positional relationship, the positioning pins 36d and 36e can be easily guided and inserted into the positioning holes 97a and 97b. Therefore, even if there is a displacement in the positional relationship between the tables 36 and 46 and the plate-holding element 90, it is likely that the plate-holding element 90 will be placed in a correct position on the tables 36 and 46, and it is likely that the condition shown in Fig. 7B will occur, i.e., the condition in which the vacuum supply port 36b and the connecting port 96 are opposite each other and connected to each other. If the control device 100 detects that a predetermined time has elapsed in step S160 without the placement of the plate holder 90 on the holder placement surface 36a of the table 36 or 46 being detected in step S150 after the lowering of the pusher 24 in step S140, the control device 100 determines that the placement of the plate holder 90 on the table 36 or 46 was not carried out correctly, issues an error message to the control panel (step S170) and terminates the holder loading process. If, however, in step S150 the control device 100 detects the placement of the plate holder 90 on the holder placement surface 36a of the table 36 or 46 before a predetermined time has elapsed after the start of the lowering of the pusher 24 in step S140, the control device 100 controls the holder lifting and lowering device 37 or 47 for the holder such that the table 36 or 46 is lowered into its starting position (step S180). The control device 100 places another plate holder 90, held by the conveyor box 80, onto another table using the same control device. Then the control device 100 unloads the conveyor box 80, from which two plate holders 90 have been taken, onto the storage rack 70 (step S190) and ends the holder loading process.This means that the control device 100 controls the head movement device 26 and the frame return and forward movement device 64 so that the conveyor box 80, which is supported by the support rail 29, is pushed forward by the pusher 24, unloaded from the main body of the working device 11 and stored in the storage rack 70. As described above, the unloading process for the holding element is essentially performed by an operation that is the opposite of the loading process for the holding element, which is why a detailed description of it is omitted. However, if, for example, the unloading target placed on the table 36, namely the plate holding element 90, is held by the conveyor box 80 during the unloading process, the control device 100 performs the following operation. First, the control device 100 lowers the pusher 24 relative to the conveyor box 80, which has been moved to a position above the table 36 on which the plate holding element 90 is placed, thereby moving the pair of arm elements 82 of the conveyor box into the holding release position. Next, the table 36 is raised to the pressure height, and then the pusher 24 is raised to switch the pair of arm elements 82 of the conveyor box 80 from the holding release position to the holding position.Accordingly, the plate holder 90, placed on table 36, is held by the conveyor box 80 as the unloading target. While the slide 24 is raised, the control device 100 uses the detection section 38 to determine whether the plate holder 90 has been detached from table 36 (i.e., whether the position of the plate holder 90 is no longer being detected). If it is then determined that the plate holder 90 has not been detached from table 36 even after a predetermined time has elapsed since the slide 24 began to be raised, and it is determined that the movement of the plate holder 90 from table 36 (e.g., the holding of the plate holder 90 by the conveyor box 80) was not executed correctly, an error message is sent to the control panel, and the unloading process is terminated.If, however, it is detected that the plate holder 90 has been detached from the table 36 before the expiry of a predetermined time, the control device 100 determines that the plate holder 90 is being properly held by the conveyor box 80 and lowers the table 36. The control device 100 also causes the conveyor box 80 to hold the plate holder 90 as the unloading target, which is then placed on the table 46 by the same control device. The control device 100 then executes the conveyor box 80, which holds two plate holders 90, to the storage rack 70 and completes the unloading process. Here, a correspondence relationship between the main elements of the embodiment and the main elements of the present disclosure, as described in the claims, is described. That is, the plate S corresponds to a plate, the working device 10 corresponds to a working device, the plate holding element 90 corresponds to a plate holding element, the tables 36 and 46 correspond to a table, the conveyor box 80 corresponds to a conveyor box, the frame return and forward movement device 64, the head movement device 26 and the pusher 24 correspond to a box conveyor section, the pusher 24 and the pusher lifting device 25 correspond to an attachment and removal section, the control device 100 corresponds to a control device, the plate support surface 91 corresponds to a plate support surface, the contact surfaces 95a and 95b correspond to a contact surface, and the suction port 91a corresponds to a suction opening.The connection port 96 corresponds to a connection opening, the retaining section 93 corresponds to a retaining section, the retaining element placement area 36a corresponds to a retaining element placement area, and the vacuum supply port 36b corresponds to a vacuum supply opening. Furthermore, the seal 96a corresponds to a seal, the magnets 98a and 98b correspond to magnets, the detection sections 38 and 48 correspond to a detection section, the first edge section 93a corresponds to a first edge section, the second edge section 93b corresponds to a second edge section, the first arm element 82a corresponds to a first arm section, and the second arm element 82b corresponds to a second arm section. In the working device 10 of the present embodiment, described in detail above, the plate holding element 90 holds the holding section 93 and can be held by the conveyor box 80. The control device 100 can then control the frame return and forward movement device 64, the head movement device 26, the pusher 24, and the holding element lifting and lowering device 25, and perform the holding element exchange process, including the holding element unloading and loading processes, using the conveyor box 80.Furthermore, the plate holding element 90 has contact surfaces 95a and 95b that face the plate support surface 91 and come into contact with the table 36 or 46 when the plate holding element 90 is placed on the table 36 or 46, as well as a connecting port 96 that connects to the suction port 91a for holding the plate S by suction and is open to an opposite side of the plate support surface 91. The tables 36 and 46, on which the plate holding element 90 is placed, have a vacuum supply port 36b for supplying vacuum to the plate holding element 90. The vacuum supply port 36b is located at a position that communicates with the connecting port 96 of the plate holding element 90 when the plate holding element 90 is in place.Therefore, placing the inserted plate holder 90 onto the table 36 or 46 creates a condition in which a vacuum can be supplied from the vacuum supply port 36b via the connecting port 96 to the suction port 91a. Thus, it is not necessary to perform the process of connecting the vacuum supply path to the plate holder 90 as a separate process from the process of placing the plate holder 90 onto the table 36 or 46. Because of the above, it is simple to connect the vacuum supply path to the plate holder 90 in the work device 10 once the plate holder 90 is installed in the work device 10. Furthermore, the working device 10 includes an elastic seal 96a, which is arranged at at least one (here: connection port 96) connection port 96 of the plate holding element 90 and vacuum supply port 36b of the table 36 (or table 46). Since the seal 96a can seal a space between the connection port 96 and the vacuum supply port 36b, it is possible to supply a vacuum more reliably to the suction port 91a of the plate holding element 90. Furthermore, the working device comprises 10 magnets 98a and 98b, which are arranged on at least one (here, the plate holding element 90) of the plate holding element 90 and the table 36 (or table 46) and attract the other element of the plate holding element 90 and the table 36 with magnetic force. This allows the plate holding element 90 and the table 36 (or table 46) to come into closer contact with each other more easily due to the magnetic force, thus preventing the connection port 96 and the vacuum supply port 36b from becoming separated. Therefore, it is possible to supply the suction port 91a of the plate holding element 90 with vacuum more reliably. The work device 10 comprises detection sections 38 and 48, which detect the placement of the plate holder 90 on the plate holder placement surface 36a of tables 36 and 46. Using the detection sections 38 and 48, the control device 100 performs at least one (here both) of the following functions: detecting the separation of the plate holder 90 from the plate holder placement surface 36a during the plate holder unloading process and detecting the placement of the plate holder 90 on the plate holder placement surface 36a during the plate holder loading process. Thus, the control device 100 can detect whether at least one (here both) of the movements of the plate holder 90 from tables 36 and 46 during the unloading process and the placement of the plate holder 90 on tables 36 and 46 during the loading process were executed correctly. Furthermore, during the unloading process, the control device 100 moves the conveyor box 80 to a position above the plate holding element 90 as the unloading target, switches the first arm element 82a and the second arm element 82b of the conveyor box 80 from the holding release position to the holding position, and attaches the plate holding element 90 as the unloading target to the conveyor box 80. Additionally, during the loading process, the control device 100 moves the conveyor box 80, to which the plate holding element 90 is attached as the loading target, to a position above the table 36 (or table 46), switches the first arm element 82a and the second arm element 82b of the conveyor box 80 from the holding position to the holding release position, and places the plate holding element 90 as the loading target onto the table 36 (or table 46).Thus, during the replacement process of the holding element, the control device 100 can attach and remove the plate holding element 90 by actuating the first arm element 82a and the second arm element 82b of the conveyor box 80 by means of the slide 24. It is obvious that the present disclosure is not limited to the embodiment described above and can be carried out in various modes, as long as the modes fall within the scope of the present disclosure. For example, in the embodiment described above, the retaining section 93 of the plate retaining element 90 comprises a first edge section 93a and a second edge section 93b, which are held by a pair of arm elements 82 of the conveyor box 80. However, the retaining section 93 and the conveyor box 80 can have any shape, as long as the plate retaining element 90 can be held and released by the conveyor box 80. For example, the plate retaining element 190 shown in Fig. 17 can be used instead of the plate retaining element 90, and the conveyor box 180 shown in Fig. 18 can be used instead of the conveyor box 80. The plate retaining element 190 comprises a retaining section 193, as shown in Fig. 17. Furthermore, the plate retaining element 190 does not include a first pin element 93c and a second pin element 93d. Otherwise, the plate retaining element 190 is similar to the plate retaining element 90.The retaining section 193 comprises a first projection section 193a and a second projection section 193b, which project from opposite side sections of the plate retaining element 190. The first projection section 193a and the second projection section 193b are, for example, cylindrical projections that project laterally. The retaining section 193 comprises two first projection sections 193a and two second projection sections 193b. The conveyor box 180 comprises a rectangular frame body 181, arm elements 182 (a first arm element 182a and a second arm element 182b) which are arranged on the frame body 181 such that their tip sections face each other and which hold the plate holding element 190 from both sides, and arm elements 183 (a first arm element 183a and a second arm element 183b) which are arranged on the frame body 181 such that their tip sections face each other and which hold the plate holding element 190 from both sides.Two first arm elements 182a and two second arm elements 182b are arranged longitudinally. Two first arm elements 183a and two second arm elements 183b are also arranged longitudinally. Each of the first arm elements 182a and 183a and the second arm elements 182b and 183b has a recessed section formed on the upper surface of a tip section thereof, which is slightly larger than the outer diameters of the first projecting sections 193a and the second projecting sections 193b. By arranging the first projecting section 193a and the second projecting section 193b in the recessed section, the conveyor box 180 can transport the plate-holding element 190 while fixing the position of the plate-holding element 190 in the front-to-back direction. Two first arm elements 182a of the arm element 182 support two first projecting sections 193a, and two second arm elements 182b support two second projecting sections 193b.Two first arm elements 183a of the arm element 183 support two first projection sections 193a, and two second arm elements 183b support two second projection sections 193b. Thus, the conveyor box 180 can hold the plate holding element 190 with the arm element 182 and the arm element 183 and convey a total of two plate holding elements 190, which are used in the first and second plate conveying and holding device 30 and 40, simultaneously. The operation of the control device 100 when the exchange process of the plate holder 190 is carried out using the conveyor box 180 is described with reference to Fig. 19. A detailed description of the operations, which are carried out in the same manner as in the embodiment described above, such as the loading and unloading of the conveyor box 180 between the storage rack 70 and the work device 10, and the detection and fine-tuning of the position of the plate holder 190 using the camera device 50, is omitted. During the unloading of the holder, the control device 100 moves the conveyor box 180 to a position above the plate holder 190 as the unloading target and lifts the plate holder 190 as the unloading target, which is placed on the tables 36 and 46 (Fig. 19A).When transporting the conveyor box 180, the control device 100 causes the arm elements 182 and 183 (first arm elements 182a and 183a and second arm elements 182b and 183b) to be positioned in the front-back direction (forward in Fig. 19A) as they are moved from positions directly above the first projection section 193a and the second projection section 193b of the plate holding element 190. Additionally, when raising the plate holding element 190, the control device 100 raises the plate holding element 190 to a height at which the first projecting section 193a and the second projecting section 193b of the plate 190 are located above the arm elements 182 and 183 (first arm elements 182a and 183a and second arm elements 182b and 183b) of the conveyor box 180 (see Fig. 19A).The control device 100 then transports the conveyor box 180 further, so that the first arm elements 182a and 183a and the second arm elements 182b and 183b are located directly below the first projecting section 193a and the second projecting section 193b of the plate 190 (Fig. 19B). In this state, the control device 100 lowers the tables 36 and 46. Thus, when the plate-holding element 190 is lowered, the first arm elements 182a and 183a and the second arm elements 182b and 183b of the conveyor box 180 support the first projecting section 193a and the second projecting section 193b of the plate-holding element 190, and the plate-holding element 190 is attached to the conveyor box 180 (Fig. 19C). When tables 36 and 46 are lowered, tables 36 and 46 and the tabletop support element 190 are separated from each other.The control device 100 can detect this separation, as in the embodiment described above, using the detection sections 38 and 48, and can detect whether the movement of the plate-holding element 190 from the tables 36 and 46 was executed correctly during the unloading process. After the plate-holding element 190 has been attached to the conveyor box 180 in this way, the control device 100 unloads the conveyor box 180 from the work device 10 and ends the unloading process. The loading process for the holding element using the conveyor box 180 can essentially be carried out by a process that is the opposite of the unloading process. In particular, the control device 100 transports the conveyor box 180, to which the plate holding element 190 serving as the loading target is attached, to a position above the tables 36 and 46 (Fig. 19C). Subsequently, the control device 100 raises the tables 36 and 46 to separate the first projecting section 193a and the second projecting section 193b of the plate holding element 190 serving as the loading target from the first arm elements 182a and 183a and the second arm elements 182b and 183b, thereby releasing the plate holding element 190 from the conveyor box 180 and placing it on the tables 36 and 46 (Fig. 19B).The control device 100 can detect this placement, as described above, using the detection sections 38 and 48, and can detect whether the placement of the plate-holding element 190 on the tables 36 and 46 was carried out correctly during the loading process of the plate-holding element. Furthermore, the control device 100 can raise the tables 36 and 46 until a predetermined time has elapsed since the placement was detected. This predetermined time can be set in advance as the waiting time until the plate-holding element 190 is released from the conveyor box 180. Thus, the control device 100 can reliably release the plate-holding element 190 from the conveyor box 180 using the detection sections 38 and 48.Next, the control device 100 moves the conveyor box 180 so that the arm elements 182 and 183 (first arm elements 182a and 183a and second arm elements 182b and 183b) are arranged in the front-to-back direction (forward in Fig. 19A) as they are moved from positions directly above the first projecting section 193a and the second projecting section 193b of the plate 190 (see Fig. 19A). The control device 100 then lowers the tables 36 and 46. Additionally, the control device 100 unloads the conveyor box 180 and completes the holding element loading process. The control device 100 can use the detection sections 38 and 48 to determine whether the plate holding element 190 remains on the tables 36 and 46 during the lowering of the tables 36 and 46.In this way it is possible, for example, to detect an anomaly, such as a case in which the plate holding element 190 collides with the arm element 182 or the arm element 183 of the conveyor box 180 and is separated from the tables 36 and 46 during the lowering of the tables 36 and 46. When the conveyor box 180 and the plate-holding element 190 described above are used, it is not necessary to move the arm element 82 by means of the pusher 24 as in the embodiment described above, and, during the holding element exchange process, to move the holding element lifting and lowering devices 37 and 47, or to raise the tables 36 and 46, in order to attach or detach the plate-holding element 190 from the conveyor box 180. Therefore, the arm elements 182 and 183 of the conveyor box 180 do not need to have a movable section, and the conveyor box 180 can have a simple configuration. In this respect, the holding element lifting and lowering devices 37 and 47 for the holding element correspond to an attachment and removal section of the present disclosure. In the embodiment described above, the seal 96a is arranged at the connecting port 96, but additionally or instead of it, a seal may be arranged at the vacuum supply port 36b. In the embodiment described above, magnets 98a and 98b are arranged on the plate-holding element 90, but additionally or instead, a magnet can be arranged on the plate 36 (or plate 46). It should be noted that it is preferable to provide magnets on the plate-holding element 90 rather than on the tables 36 and 46, as such a configuration can prevent a malfunction in which metal parts adhere to the tables 36 and 46 due to magnetic force. In the embodiment described above, a capacitive proximity sensor is used as sensing sections 38 and 48, but the present disclosure is not limited thereto. For example, a sensor other than a capacitive proximity sensor (inductive proximity sensor, magnetic proximity sensor, or the like) can be used as sensing section 38 (or sensing section 48), or a contact limit switch can be used. In the embodiment described above, the working device 10 comprises two tracks that transport and support the plate S, but there may also be only one track. In the embodiment described above, the working device of the present disclosure has been described as being applied to a printing device, but is not limited to this, and the working device can be applied to any working device that performs work on a plate held by a holding element, such as a component assembler. The working device and the plate holding element of the present disclosure can be configured as follows. The working device of the present disclosure can include an elastic seal arranged at at least one of the connecting ports of the plate and the vacuum supply port of the table. In this way, the seal can seal a space between the connecting port and the vacuum supply port, thereby making it possible to supply the vacuum port of the plate with vacuum more reliably. The working device of the present disclosure can include a magnet arranged on at least one of the plate-holding element and the table, and configured to attract the other element of the plate-holding element and the table with magnetic force. In this way, the plate and the table can be easily brought into close contact with each other by magnetic force, thus preventing the connecting port and the vacuum supply port from separating from each other. Therefore, it is possible to supply the vacuum port of the plate-holding element with vacuum more reliably. The working device of the present disclosure can include a detection section configured to detect the placement of the plate holder on the plate holder placement surface of the table, and the control device can perform at least one of the following functions using the detection section: detecting the separation of the plate holder from the plate holder placement surface during the plate holder unloading process and detecting the placement of the plate holder on the plate holder placement surface during the plate holder loading process. In this way, it can be detected whether at least one of the following actions has been performed correctly: the movement of the plate holder from the table during the plate holder unloading process and the placement of the plate holder on the table during the plate holder loading process. In the working device of the present disclosure, the holding section of the plate holding element can comprise a first edge section arranged on a surface opposite the plate support surface and located closer to the plate support surface than the contact surface and situated on an outer edge section of the plate holding element, and a second edge section arranged on the surface opposite the plate support surface and situated closer to the plate support surface than the contact surface and situated on an outer edge section of the plate holding element opposite the first edge section, wherein the conveyor box can have a first arm section configured to hold the first edge section of the plate holding element, and a second arm section arranged such that the tip sections of the first arm section and the second arm section face each other, and which is configuredthat it supports the second edge section, the attachment and removal section can actuate the first arm section and the second arm section to switch between a holding position in which the first arm section and the second arm section can hold the plate holding element from both sides, and a holding release position in which the holding function is released, wherein the holding element unloading process can allow the control device to move the conveyor box to a position above the plate holding element as the unloading target, switch the first arm section and the second arm section of the conveyor box from the holding release position to the holding position, and attach the plate holding element to the conveyor box as the unloading target, and in the holding element loading process, the control device can move the conveyor box, to which the plate holding element is attached as the loading target, to a position above the table.Switch the first and second arm sections of the conveyor box from the holding position to the holding release position and place the plate holder on the table as the loading target. In this way, during the plate holder exchange process, it is possible to attach and detach the plate holder by means of the attachment and removal process, which actuates the first and second arm sections of the conveyor box. In the working device of the present disclosure, the holding section of the plate holding element can comprise a first projection section and a second projection section projecting from opposite side sections of the plate holding element, wherein the conveyor box can have a first arm section configured to support the first projection section of the plate holding element, and a second arm section arranged such that the tip sections of the first arm section and the second arm section face each other, and configured to hold the second projection section; the mounting and removal section can raise and lower the plate holding element placed on the table by raising and lowering the table; in the holding element unloading process, the control device can transport the conveyor box to a position above the plate holding element as the unloading destination.The control device can lift the plate as the unloading target, which is placed on the table, and then transport the conveyor box to lower the plate holding element so that the first projection section and the second projection section are supported by the first arm section and the second arm section, and the plate holding element is attached to the conveyor box. During the plate holding element loading process, the control device can perform an operation to transport the conveyor box, to which the plate holding element is attached as the loading target, to a position above the table and to lift the table to separate the first projection section and the second projection section of the plate holding element as the loading target from the first arm section and the second arm section.so that the plate holding element is detached from the conveyor box and placed on the table. In this way, the plate holding element can be attached and removed during the holding element exchange process by raising and lowering the table through the attachment and removal section. The plate-holding element of the present disclosure is arranged for use in a work device for performing work on a plate and is installed on a table of the work device to hold the plate, wherein the plate-holding element comprises a plate support surface on which the plate is placed, a contact surface opposite the plate support surface and configured to make contact with the table when the plate-holding element is placed on the table, a suction port configured to hold the plate by suction, the suction port being located on the plate support surface, a connecting port connected to the suction port and open to an opposite side of the plate support surface, and a holding section configured to be held by a conveyor box used for loading and unloading the plate-holding element into and out of the work device.is configured from the work device. The plate holder has a holding section and can be held by the conveyor box. Therefore, the plate holder can be loaded into and unloaded from the work device using the conveyor box. Furthermore, the plate holder has a contact surface opposite the plate support surface, configured to make contact with the table when the plate holder is placed on the table, and a connecting port that connects to the suction port, configured to hold the plate by suction, and which is open to the opposite side of the plate support surface.Therefore, if the vacuum supply port is located at a point that communicates with the connection port of the plate holder when the plate is placed on the table, placing the plate holder on the table of the work device allows the vacuum supply port and the connection port to communicate with each other, thus enabling the supply of a vacuum to the suction port. In this way, it is not necessary to perform the process of connecting the vacuum supply line to the plate holder as a separate process from the process of placing the plate holder on the table. Because of the above, the vacuum supply line can be easily connected to the plate holder when the plate holder is installed in the work device.The plate holding element can incorporate various aspects of the plate holding element in the work device described above, or it can also add a configuration arranged in the plate holding element in the work device described above. The present description also discloses a technical idea wherein “the working device according to claim 1 or 2” in claim 4 as originally filed is amended to “the working device according to one of claims 1 to 3”, a technical idea wherein “the working device according to claim 1 or 2” in claim 5 as originally filed is amended to “the working device according to one of claims 1 to 4”, and a technical idea wherein “the working device according to claim 1 or 2” in claim 6 as originally filed is amended to “the working device according to one of claims 1 to 4”. Industrial applicability The present disclosure is applicable to a working device that performs work on a plate, such as an assembly device that mounts a component on the plate or a printing device that is connected to the assembly device. List of reference symbols 10: Working device, 11: Working device main body, 20: Head device, 21: Head, 22: Doctor blade, 23: Doctor blade lifting and lowering device, 24: Pusher, 25: Pusher lifting and lowering device, 26: Head movement device, 27: Y-axis slider, 28: Guide rail, 29: Support rail, 30: First plate conveying and holding device, 31, 41: Conveyor device, 32, 42: Plate guide, 33b, 43b: Base frame, 33s, 43s: Side frame, 34, 44: Conveyor interval changing device, 35, 45: Conveyor lifting and lowering device, 36, 46: Table, 36a: Holding element placement surface, 36b: Vacuum supply connection, 36c: Tube, 36d, 36e: Positioning pin, 37, 47: Holding element lifting and lowering device, 38, 48: Detection section, 40: Second plate conveying and holding device, 50: Camera device, 51: Camera main body, 52: Upper reading section, 53: Lower reading section, 55: Camera movement device, 56: X-axis slider, 57: X-axis guide rail, 58: Y-axis slider,59: Y-axis guide rail, 60: Exchange device, 61a: Left unit, 61b: Right unit, 62: Shelf retaining element, 63: Shelf lifting and lowering device, 64: Frame retraction and forward movement device, 65: Pressure reducing device, 70: Storage rack, 71: Support rail, 72, 73: Opening section, 80: Conveyor box, 81: Frame body, 82: Arm element, 82a: First arm element, 82b: Second arm element, 90: Panel retaining element, 91: Panel support surface, 91a: Suction port, 92: Rear, 93: Retaining section, 93a: First edge section, 93b: Second edge section, 93c: First pin element, 93d: Second pin element, 94a: First leg section, 94b: Second Leg section, 95a, 95b: Contact surface, 96: Connection port, 96a: Seal, 97a, 97b: Positioning hole, 98a, 98b: Magnet, 99a: First identification mark, 99b: Second identification mark, 100: Control device, 101: Storage device, 180: Conveyor box, 181: Frame body, 182, 183: Arm element, 182a, 183a: First arm element182b, 183b: Second arm element, 190: Plate retaining element, 193: Retaining section, 193a: First projection section, 193b: Second projection section, 200: Management device, 241: Push plate, 242: Push roller, 821: Base element, 822: Arm plate, 822c: Notch, 823: Retaining element, 824: Torsion coil, 825: Side plate, 826: Locking plate, 827: Locking block, 828: Tension spring, F: Frame, M: Screen mask, P1, P2: Pattern hole, S: Plate, QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature WO 2022 / 234650

[0003]

Claims

A work device for performing work on a panel, the work device comprising: a panel holding element configured to hold the panel; a table on which the panel holding element is placed; a box conveying section configured to convey a box capable of holding the panel holding element; an attachment and removal section configured to allow the box to hold and release the panel holding element; and a control device configured to control the box conveying section and the attachment and removal section, wherein the panel holding element comprises a panel support surface on which the panel is placed, a contact surface opposite the panel support surface, the contact surface being configured to make contact with the table when the panel holding element is placed on the table, and a suction port configured toto hold the plate by suction, wherein the suction port is located on the plate support surface, a connecting port that communicates with the suction port and is open to an opposite side of the plate support surface, and a holding section configured to be held by the conveying box, wherein the table has a holding element placement surface for the holding element on which the plate holding element is placed, and a vacuum supply port configured to supply a vacuum to the plate holding element, wherein the vacuum supply port is located at a point that communicates with the connecting port in a state in which the plate is placed on the table, and the control device causes the box conveying section and the attachment and removal section to perform an exchange operation for the holding element.which includes an unloading process for the holding element for loading the conveyor box, attaching the plate placed on the table as the unloading target to the loaded conveyor box so that the plate holding element is held, and unloading the conveyor box after release, and a loading process for the holding element in which the conveyor box, to which the plate holding element serving as the loading target is attached, is loaded, the plate holding element serving as the loading target is released from the conveyor box by releasing the holding of the plate holding element, the released plate holding element is placed on the table, and the conveyor box is unloaded after release. The working device according to claim 1, which further comprises: an elastic seal which is arranged at at least one of the connecting ports of the plate holding element and the vacuum supply port of the table. The working device according to claim 1 or 2, further comprising: a magnet arranged on at least one of the plate holding element and the table, and configured to attract the other of the plate holding element and the table with magnetic force. The working device according to claim 1 or 2, further comprising: a detection section configured to detect the placement of the plate holder on the holder placement surface of the table, wherein the control device, using the detection section, performs at least one of the following functions: detecting the separation of the plate holder from the holder placement surface during the holder unloading process and detecting the placement of the plate holder on the holder placement surface during the holder loading process. The working device according to claim 1 or 2, wherein the holding section of the plate holding element comprises a first edge section arranged on a surface opposite the plate support surface and located closer to the plate support surface than the contact surface and situated on an outer edge section of the plate holding element, and a second edge section arranged on the surface opposite the plate support surface and situated closer to the plate support surface than the contact surface and situated on an outer edge section of the plate holding element opposite the first edge section, the conveyor box having a first arm section configured to hold the first edge section of the plate holding element, and a second arm section arranged such that the tip sections of the first arm section and the second arm section face each other, and configured to hold the second edge section.The attachment and removal section actuates the first arm section and the second arm section to switch between a holding position, in which the first arm section and the second arm section can hold the plate holding element from both sides, and a holding release position, in which the hold is released; wherein, during the holding element unloading process, the control device moves the conveyor box to a position above the plate as the unloading target, switches the first arm section and the second arm section of the conveyor box from the holding release position to the holding position, and attaches the plate holding element to the conveyor box as the unloading target; and during the holding element loading process, the control device moves the conveyor box, to which the plate holding element is attached as the loading target, to a position above the table.switches the first arm section and the second arm section of the conveyor box from the holding position to the holding release position and places the plate holding element on the table as the loading target. The working device according to claim 1 or 2, wherein the holding section of the plate holding element comprises a first projection section and a second projection section projecting from opposite side sections of the plate holding element, the conveyor box has a first arm section configured to hold the first projection section of the plate holding element, and a second arm section arranged such that the tip sections of the first arm section and the second arm section face each other and are configured to hold the second projection section, the mounting and removal section raises and lowers the plate holding element placed on the table by raising and lowering the table, and in the holding element unloading process, the control device moves the conveyor box to a position above the plate holding element as the unloading destination.The control device lifts the plate holder placed on the table as the unloading target and then transports the conveyor box to lower the plate holder so that the first and second protruding sections are held by the first and second arm sections, and the plate holder is attached to the transport device. In the holder loading process, the control device performs a process in which the conveyor box, to which the plate holder is attached as the loading target, is transported to a position above the table, and the table is lifted to separate the first and second protruding sections of the plate holder as the loading target from the first and second arm sections, so that the plate holder is released from the conveyor box and placed on the table. A panel holding element for use in a work device configured to perform work on a panel and installed on a table of the work device to support the panel, the panel holding element comprising: a panel support surface on which the panel is placed; a contact surface opposite the panel support surface, the contact surface being configured to make contact with the table when the panel holding element is placed on the table; a suction port configured to hold the panel by suction, the suction port being located on the panel support surface; a connecting port connected to the suction port and open to an opposite side of the panel support surface;and a holding section configured to be held by a conveyor box configured to insert and remove the plate holding element from the work device.

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