JP7578035B2 - Workpiece transport device and workpiece transport method - Google Patents

Description

This disclosure relates to a workpiece transport device and a workpiece transport method.

Patent Document 1 presents a conveying device that conveys a workpiece that is located at the top of a stack of plate-shaped workpieces by separating it from the other workpieces. In this conveying device, a seesaw member is provided at the end of a conveying body that conveys the workpieces so that it can swing. A contactor that comes into contact with the surface of the workpiece is provided at the center of the seesaw member. A first suction pad that adsorbs the surface of the end of the workpiece is provided at one end of the seesaw member. A second suction pad that contracts more than the first suction pad is provided at the other end of the seesaw member. When the first and second auxiliary pads start adsorbing the surface of the workpiece with the contactor in close proximity to the surface of the workpiece, the second auxiliary pad contracts, and the first auxiliary pad is lifted by the swing of the seesaw member. As a result, the end of the topmost workpiece is lifted by the adsorption of the first auxiliary pad. The lifted workpiece is partially separated from the other workpieces. The conveying device then rises, and the topmost workpieces are conveyed one by one.

JP 2019-214106 A

When handling workpieces that have a recess on one surface and a protrusion on the other surface at a position corresponding to the recess, multiple workpieces may be stacked vertically and prepared for transport. In adjacent workpieces among the multiple stacked workpieces, the recess of the workpiece located above in the vertical direction may fit into the protrusion of the workpiece located below in the vertical direction. In this case, even if the end of the workpiece located at the top in the vertical direction is lifted by the suction of the transport device using the technology of Patent Document 1, one or more workpieces located below the workpiece may be lifted in addition to the workpiece that was sucked up due to the recess of the workpiece fitting into the protrusion of the workpiece below it. For this reason, when each workpiece has a recess and a protrusion, there has been a demand for a technology that can more reliably separate one workpiece from the other works and transport them.

This disclosure can be realized in the following forms:

(1) According to one embodiment of the present disclosure, there is provided a method for transporting a workpiece, the method for transporting a workpiece comprising: (a) preparing a plurality of workpieces each having a convex portion on one surface and a concave portion on the other surface at a position corresponding to the convex portion, the plurality of workpieces being in contact with each other such that the concave portion of one workpiece fits into the convex portion of the other workpiece, (b) heating the convex portion of a first workpiece located at an end of the plurality of workpieces and a second workpiece adjacent to the first workpiece, the convex portion of which is received in the concave portion of the first workpiece, and (c) after the above step (b), transporting the first workpiece while leaving all of the plurality of workpieces other than the first workpiece.
According to this embodiment of the workpiece transport method, the convex portion of one of the first and second workpieces, which has its convex portion received in its concave portion, expands when heated. This causes a gap to form between the convex portion of the one workpiece and the surface of the concave portion of the workpiece which has its convex portion received in its concave portion. As a result, the first workpiece can be transported while leaving behind the workpieces other than the first workpiece.
(2) In the above-described form of the workpiece transport method, in step (a), the recess of the first workpiece receives the convex portion of the second workpiece, and step (b) may be a step of heating the non-contact portion of the recess of the first workpiece, which is a contact portion that is in contact with the convex portion of the second workpiece, and a non-contact portion that is not in contact.
According to the method for transporting a workpiece of this embodiment, the expansion of the second workpiece can be suppressed when the first workpiece is heated, compared to a process in which the contact portion is heated, and therefore, it is possible to transport the first workpiece more easily, leaving behind the workpiece other than the first workpiece.
(3) In the above-described workpiece transport method, the method may further include (d) a step of repeating the steps (b) and (c), and the step (d) may be performed by setting the heating temperature of the step (b) performed for the mth time (m is a positive integer) higher than the heating temperature of the step (b) performed for the nth time (n is a positive integer smaller than m).
According to this embodiment of the workpiece transport method, the heating temperature can be increased depending on the environment and situation of the transport.
(4) In the method of transporting a workpiece according to the above aspect, in the step (d), the step (b) may be performed by setting the heating temperature higher than the heating temperature in the previous step (b).
According to this embodiment of the workpiece transport method, the workpiece that receives the convex portion of the other workpiece in the concave portion expands more than in the previous step (b), so that the first workpiece can be transported while leaving behind more of the workpiece other than the first workpiece than in the previous step (b).
(5) In the workpiece transport method of the above aspect, the step (b) may be a step of heating the convex portion by radiating infrared rays.
According to this form of workpiece transport method, it is possible to heat a workpiece having a convex portion received in a recessed portion of one workpiece without contacting the workpiece having a convex portion received in a recessed portion of the other workpiece.
(6) In the above-described form of the method for transporting a workpiece, the step (a) may be a step of preparing the plurality of workpieces stacked in the vertical direction, in which the concave portion of the upper workpiece in the vertical direction and the convex portion of the lower workpiece in the vertical direction are fitted into each other among two adjacent workpieces, and the step (b) may be a step of heating the convex portion of the first workpiece that is located highest in the vertical direction among the plurality of workpieces.
According to this embodiment of the workpiece transport method, the convex portion of the first workpiece expands when heated. As a result of the expansion of the convex portion of the first workpiece, a gap is generated between the surface of the concave portion of the first workpiece and the surface of the convex portion of the second workpiece when the first workpiece is transported. Therefore, the first workpiece can be transported while leaving behind the parts other than the first workpiece.
(7) In the above-described form of the work transport method, the step (a) may be a step of preparing the multiple workpieces stacked in the vertical direction, where the multiple workpieces are stacked in a state in which the convex portion of the upper workpiece in the vertical direction and the concave portion of the lower workpiece in the vertical direction fit into each other among two adjacent works, and the step (b) may be a step of heating the convex portion of the second workpiece that overlaps with the first workpiece that is located at the topmost in the vertical direction among the multiple works.
According to this embodiment of the workpiece transport method, the convex portion of the second workpiece expands when heated. As a result of the expansion of the convex portion of the second workpiece, a gap is generated between the surface of the convex portion of the first workpiece and the surface of the concave portion of the second workpiece when the first workpiece is transported. Therefore, the first workpiece can be transported while leaving behind the parts other than the first workpiece.
(8) According to another aspect of the present disclosure, there is provided a workpiece transport device, the workpieces being a plurality of workpieces each having a convex portion on one side and a concave portion on the other side at a position corresponding to the convex portion, the plurality of workpieces being in contact with each other with the concave portion of one of the plurality of workpieces fitting into the convex portion of the other workpiece, the transport device including a heating unit for heating the convex portion of a first workpiece that is an end workpiece and a second workpiece that is adjacent to the first workpiece, the convex portion of one of the plurality of workpieces being received in the concave portion, a gripping unit that can grip the first workpiece, and a control unit that controls the transport device, the control unit causing the gripping unit to transport the first workpiece while leaving behind the workpieces other than the first workpiece among the plurality of workpieces.

FIG. 2 is a schematic diagram illustrating a workpiece transport device. FIG. 4 is a process diagram showing an example of a workpiece transport method. 5A to 5C are diagrams illustrating expansion of a first workpiece due to heating. FIG. 13 is a diagram for explaining a third embodiment. 13A to 13C are process diagrams illustrating an example of a conveying method according to a third embodiment.

A. First embodiment:
A1. Configuration of the first embodiment:
Fig. 1 is a schematic diagram illustrating a conveying device 1 for a workpiece 10. The workpiece 10 in Fig. 1 is shown in cross section. The X-axis shown in Fig. 1 is the direction in which the workpiece 10 is conveyed by the conveying device 1. The Y-axis is a direction perpendicular to the X-axis and a Z-axis described below. The Z-axis represents the vertical direction. The positive side of the Z-axis is the upper side in the vertical direction, and the negative side of the Z-axis is the lower side in the vertical direction.

The workpiece 10 will be described. In this embodiment, the workpiece 10 is transported from the negative side of the X-axis to the positive side by the transport belt 20 described later. The workpiece 10 transported by the transport belt 20 is gripped and transported by the gripping unit 23 described later. The transport of the workpiece 10 by the transport belt 20 is called the "first transport". The transport of the workpiece 10 by the gripping unit 23 is called the "second transport". A plurality of workpieces 10 of the same shape are stacked vertically. Note that five workpieces are shown in FIG. 1, but the number of workpieces may be any number. One workpiece 10 has one convex portion 11 on one surface, which is the upper surface of the Z-axis. One workpiece 10 has one concave portion 12 on the other surface, which is the lower surface of the Z-axis. The concave portion 12 is provided at a portion of the other surface of the workpiece 10 that corresponds to the convex portion 11. The corresponding portions are the portions where the convex portion 11 and the concave portion 12 overlap when viewed from the Z-axis direction, which is perpendicular to a plane parallel to the X-axis and Y-axis of the workpiece 10. In other words, the convex portion 11 and the concave portion 12 of one workpiece 10 are in a front-back relationship with each other through the thickness of the workpiece 10 itself.

The work 10 located at the top in the vertical direction is called the first work 101. The convex portion 11 of the first work 101 is called the first convex portion 111, and the concave portion 12 is called the first concave portion 121. The work 10 located below the first work 101 in the vertical direction and overlapping the first work 101 is called the second work 102. The convex portion 11 of the second work 102 is called the second convex portion 112, and the concave portion 12 is called the second concave portion 122. The first work 101 and the second work 102 are adjacent to each other. The work 10 located below the second work 102 in the vertical direction and overlapping the second work 102 is called the third work 103. The convex portion 11 of the third work 103 is called the third convex portion 113, and the concave portion 12 is called the third concave portion 123. The second workpiece 102 and the third workpiece 103 are adjacent to each other.

As shown in FIG. 1, the first work 101 and the second work 102 are stacked together with the first recess 121 and the second protrusion 112 fitted together. The second protrusion 112 is received in the first recess 121. Furthermore, the second work 102 and the third work 103 are stacked together with the second recess 122 and the third protrusion 113 fitted together. In this way, the multiple work pieces 10 are first transported by the transport belt 20 with the recess 12 of the upper work piece 10 in the vertical direction and the protrusion 11 of the lower work piece 10 fitted together and stacked together.

In this embodiment, the first workpiece 101 has a portion between the surface of the first recess 121 and the surface of the second protrusion 112 where the first recess 121 and the second protrusion 112 are not in contact. This portion is called the non-contact portion 130. The portion of the first workpiece 101 where the surface of the first recess 121 and the surface of the second protrusion 112 are in contact is called the contact portion 140. The material of the workpiece 10 is an iron plate. The workpiece 10 is a magnetic body.

1, the conveying device 1 includes a conveying belt 20, three heating units 21, a temperature acquisition unit 22, a gripping unit 23, a weight sensor unit 24, and a control unit 25. The conveying belt 20 moves from the negative side to the positive side of the X-axis in FIG. 1 to first convey the multiple workpieces 10. The conveying belt 20 is a belt whose longitudinal direction is the X-axis direction. In this embodiment, an electromagnet 20a is installed at a portion of the conveying belt 20 where the workpieces 10 are placed. Of the multiple workpieces 10, the workpiece 10 located at the lowermost position in the vertical direction is attracted by the magnetic force of the electromagnet 20a. The magnetic force at this time is such that when the first workpiece 101 is placed directly above the electromagnet 20a by the gripping unit 23, the first workpiece 101 is lifted from the conveying belt 20. This makes it possible to prevent the workpiece 10 from falling in the X-axis or Y-axis direction while being conveyed by the conveying belt 20.

The heating unit 21 heats the first convex portion 111 of the first workpiece 101. Specifically, the heating unit 21 heats the non-contact portion 130 without heating the contact portion 140. The heating unit 21 heats the first workpiece 101 by radiating infrared rays (see 21a in FIG. 1). The heated range is the range that includes the center point of radiation and can raise the temperature by a predetermined value per second. Heating is performed so that the heated range includes the non-contact portion 130 but does not include the contact portion 140. By heating the non-contact portion 130, the heat of the non-contact portion 130 is transferred to the contact portion 140. Note that the increase in temperature of the contact portion 140 due to heat transfer and radiant heat from the non-contact portion 130 is not included in heating.

By radiating infrared rays, the first workpiece 101 can be heated without contacting the heat source with the first workpiece 101. This eliminates the need to contact the heat source with the first workpiece 101 every time heating is performed. The heating unit 21 is controlled by the control unit 25. The temperature, time, position, etc. of the heating of the first workpiece 101 are controlled by the control unit 25. The heating temperature and time are determined by the control unit 25 based on the size, thickness, thermal conductivity, material, number of workpieces 10, the surface area of the non-contact portion 130 of the first workpiece 101, etc., input in advance by the user to the control unit 25. The heating temperature is the set temperature of the heating unit 21 set by the control unit 25. The heating unit 21 shown in FIG. 1 is attached to a support in the room in which the conveying device 1 is installed.

The temperature acquisition unit 22 acquires the temperature of the first workpiece 101. More specifically, the temperature of the non-contact portion 130 of the first workpiece 101 is acquired. The temperature information acquired by the temperature acquisition unit 22 is transmitted to the control unit 25. When the temperature acquired by the temperature acquisition unit 22 is a predetermined temperature, the temperature acquisition unit 22 transmits a signal to that effect to the control unit 25. The predetermined temperature is a temperature at which the first workpiece 101 expands to a sufficient extent so that it can be lifted up after being separated from the second workpiece 102. In other words, the temperature is a temperature at which the first workpiece 101 expands to such an extent that the gap 300 between the first recess 121 of the first workpiece 101 and the second protrusion 112 of the second workpiece 102 in the direction along the X-axis and Y-axis plane becomes large enough for the first workpiece 101 to be lifted up after being separated from the second workpiece 102. In this embodiment, the temperature acquisition unit 22 is a thermal camera. The temperature acquisition unit 22 shown in FIG. 1 is attached to the wall of the room in which the transport device 1 is installed.

The gripping unit 23 grips the first workpiece 101. In this embodiment, the gripping unit 23 is provided with an electromagnet (not shown) at a location where it comes into contact with the first workpiece 101. The gripping unit 23 grips the first workpiece 101 by magnetic force. The gripping unit 23 can release the first workpiece 101 under the control of the control unit 25. The gripping unit 23 grips the first workpiece 101 by coming into contact with the first workpiece 101 that has been heated and expanded by the heating unit 21. The first workpiece 101 gripped by the gripping unit 23 is then transported by the gripping unit 23 to a location separate from the other workpieces 10.

The weight sensor unit 24 acquires the total weight of the multiple workpieces 10 placed on the conveyor belt 20. When the total weight of the workpieces 10 changes, the weight sensor unit 24 transmits a signal to that effect to the control unit 25.

The control unit 25 controls the conveying device 1. The control unit 25 is configured as a computer equipped with a CPU, ROM, RAM, and various input/output ports that perform logical operations.

A2. Method for transporting the workpiece 10:
Fig. 2 is a process diagram showing an example of a method for transporting the workpiece 10. In step S100 in Fig. 2, the workpiece 10 is prepared. In step S100, the control unit 25 executes a first transport for the first workpiece 101. The workpieces 10 are prepared in a state where they are stacked in the vertical direction as described above (see Fig. 1). Then, the workpieces 10 are transported by the transport belt 20 toward the positive side of the X-axis. When the control unit 25 determines that the multiple workpieces 10 have been transported to a position where they are heated by the heating unit 21, the control unit 25 stops the transport belt 20.

In step S200 of FIG. 2, the first workpiece 101 is heated by the heating unit 21 under the control of the control unit 25. As described above, the non-contact portion 130 of the first workpiece 101 is heated. By heating the non-contact portion 130, the heat of the non-contact portion 130 is transferred to the contact portion 140.

In step S300, the temperature of the non-contact part 130 of the first work 101 is acquired by the temperature acquisition unit 22. In step S400, the control unit 25 determines whether the temperature of the non-contact part 130 has reached a predetermined temperature. The temperature of the non-contact part 130 may be the average of the temperatures of the multiple non-contact parts 130 acquired by the temperature acquisition unit 22, or may be the temperature of one non-contact part 130. If the control unit 25 determines that the temperature of the non-contact part 130 has reached the predetermined temperature, the control unit 25 instructs the heating unit 21 to stop heating. Then, the process proceeds to step S500. In this embodiment, the temperature of the non-contact part 130 is always acquired by the temperature acquisition unit 22 after the transition to step S300. If the control unit 25 determines that the temperature of the non-contact part 130 has reached the predetermined temperature, the control unit 25 immediately proceeds to step S500. This prevents the first workpiece 101 from being excessively heated. If the control unit 25 determines that the temperature of the non-contact portion 130 has not reached the predetermined temperature, the process proceeds to step S300.

In step S500 in FIG. 2, the control unit 25 separates the first workpiece 101 and the second workpiece 102 and transports them. Specifically, the control unit 25 instructs the gripping unit 23 to grip the first workpiece 101 and transport the first workpiece 101 separated from the second workpiece 102. In other words, of the multiple workpieces 10, the first workpiece 101 is transported, leaving behind all but the first workpiece 101.

3 is a diagram illustrating the expansion of the first workpiece 101 due to heating. As indicated by the arrow A in FIG. 3, the first workpiece 101 is lifted vertically upward by the gripping unit 23. As described above, the predetermined temperature is a temperature at which the first workpiece 101 expands sufficiently to be separated from the second workpiece 102 and lifted. The heating process of step S200 causes the non-contact portion 130 and the contact portion 140 to expand. When the first workpiece 101 is gripped by the gripping unit 23 and lifted, a gap 300 is generated between the surface of the first recess 121 and the surface of the second protrusion 112 of the second workpiece 102. The expansion of the first workpiece 101 makes it possible to lift only the first workpiece 101.

In this embodiment, by not directly heating the contact portion 140, it is possible to suppress the heat from being transferred to the second convex portion 112 of the second workpiece 102 that contacts the first workpiece 101 and the expansion of the second workpiece 102, as compared to a process in which the contact portion 140 is heated. By suppressing the expansion of the second workpiece 102, a gap 300 is more likely to occur between the first workpiece 101 and the second workpiece 102. Therefore, it is possible to more easily separate the first workpiece 101 and the second workpiece 102.

In step S600, the weight sensor unit 24 acquires the total weight, and the control unit 25 determines whether only the first workpiece 101 has been separated and transported. The weight value acquired by the weight sensor unit 24 is transmitted from the weight sensor unit 24 to the control unit 25. If the control unit 25 determines that the total weight has decreased by the weight of one workpiece 10, the process proceeds to step S700. If the control unit 25 determines that the weight has decreased by more than the weight of one workpiece 10, there is a possibility that the first workpiece 101 and the second workpiece 102 have not been separated. In this case, the process proceeds to step S610.

In step S700, the control unit 25 determines whether the process may be ended. The process may be ended when the control unit 25 determines, based on the total weight value acquired by the weight sensor unit 24, that all of the workpieces 10 have been transported by the second transport. If the determination in step S700 is Yes, the process ends. If the determination in step S700 is No, the process proceeds to S200.

After step S700, the process moves to step S200, and the work 10 that was the second work 102 in the previous process becomes the "first work 101." Then, the process proceeds.

When the process proceeds to step S610, the control unit 25 stops gripping the first workpiece 101 by the gripping unit 23 and again stacks it on the multiple workpieces 10. This prevents workpieces 10 other than the first workpiece from being gripped and transported by the gripping unit 23 together with the first workpiece 101. The process then proceeds to step S200, where heating is performed again. At this time, the workpiece 10 that was the first workpiece 101 in the previous process is treated as the "first workpiece 101" and the process proceeds.

In the above-mentioned conveying method, the first convex portion 111 of the first work 101 is heated, so that the first concave portion 121 and the first convex portion 111 expand. When the first convex portion 111 is heated, the first convex portion 111 expands in the X-axis and Y-axis directions. When the first work 101 is not gripped by the gripping portion 23, the weight of the first work 101 causes the expanded first concave portion 121 of the first work 101 to come into contact with the second convex portion 112 of the second work 102. At this time, the first work 101 and the second work 102 are fitted together with a weaker force than in the state in which the first concave portion 121 of the first work 101 and the second convex portion 112 of the second work 102 before expansion are fitted together. As a result, when the first work 101 and the second work 102 are separated and conveyed, a gap 300 is generated between the surface of the first concave portion 121 and the surface of the second convex portion 112 of the second work 102. As a result, the first workpiece 101 can be transported, leaving behind everything other than the first workpiece 101. After the first workpiece 101 has been transported to a predetermined location by the gripper 23, the control unit 25 stops gripping by the gripper 23, and the first workpiece 101 is released from the gripper 23.

B. Second embodiment:
The second embodiment is different from the first embodiment in the method of heating in step S200 in Fig. 2. Other configurations and processes are similar to those of the first embodiment, so the same reference numerals are used and detailed description is omitted.

In the second embodiment, the control unit 25 sets the heating temperature of step S200 to a temperature higher than the temperature of the previous step S200 and executes the process. As described above, the heating temperature refers to the set temperature of the heating unit 21. The process from step S200 to step S700 where a No judgment is made is called a "single conveying process". The "single conveying process" is repeated until the second conveyance is executed for all the workpieces 10. The second "single conveying process" is executed with the heating temperature set higher than that of the first "single conveying process". The third "single conveying process" is executed with the heating temperature set higher than that of the second "single conveying process".

The predetermined temperature in the second step S400 is set higher than the predetermined temperature in the first step S400. Similarly, the predetermined temperature in the third step S400 is set higher than the predetermined temperature in the second step S400.

In the second embodiment, the first work 101 expands more by increasing the heating temperature in step S200 each time the number of "one transport process" increases. Therefore, it becomes easier to separate the first work 101 and the second work 102 compared to the previous process. As described above, the multiple work pieces 10 are stacked in the vertical direction. Therefore, the work piece 10 located at the bottom in the vertical direction is more susceptible to the weight of the other work pieces 10 than the work piece 10 located at the top in the vertical direction. In other words, the work piece 10 located at the bottom in the vertical direction may have the recess 12 and the protrusion 11 more tightly fitted together than the work piece 10 located at the top. In the second embodiment, even if the recess 12 and the protrusion 11 are tightly fitted together, the first work piece 101 and the second work piece 102 can be separated and transported. In other words, the first work piece 101 can be transported while leaving behind the work piece other than the first work piece 101.

C. Third embodiment:
4 is a diagram for explaining the third embodiment. In the third embodiment, the overlapping state of the workpieces 10C and the workpieces 10C to be heated are different from those in the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 4, multiple workpieces 10C are stacked vertically. The convex portion 11C of the upper vertical workpiece 10C and the concave portion 12C of the lower vertical workpiece 10C are stacked in a fitted state. The upper vertical workpiece 10C and the lower vertical workpiece 10C are adjacent to each other. The workpiece 10C located at the top in the vertical direction is called the first workpiece 101C. The workpiece 10C that overlaps with the first workpiece 101C and is located vertically below the first workpiece 101C is called the second workpiece 102C. In the third embodiment, the conveying device 1 has two heating sections 21.

Figure 5 is a process diagram showing an example of a conveying method of the third embodiment. In step S100C, the workpiece 10C is prepared. The workpiece 10C is prepared by overlapping the convex portion 11C of the upper vertical workpiece 10C and the concave portion 12C of the lower vertical workpiece 10C in a fitted state. In step S200C, the second convex portion 112C of the second workpiece 102C is heated (see Figure 4). In step S300C, the temperature of the second convex portion 112C of the second workpiece 102C is acquired.

When the second convex portion 112C of the second workpiece 102C is heated, the second concave portion 122C of the second workpiece 102C expands in the X-axis and Y-axis directions. As a result, when the first workpiece 101C is separated and transported by the gripping portion 23, a gap is likely to occur between the surface of the first convex portion 111C of the first workpiece 101C and the surface of the second concave portion 122C of the second workpiece 102C. As a result, the first workpiece 101C can be transported, leaving behind everything other than the first workpiece 101C.

D. Other embodiments:
D1) As in the second embodiment, the heating temperature in step S200 does not always have to be higher than the temperature in the previous step S200. For example, after the heating process in step S200 is performed five times at the same temperature, the heating temperature may be increased and the process of step S200 may be performed three times. Specifically, five "one transport process" processes are performed. Then, the control unit increases the heating temperature and performs three "one transport process" processes. In this way, after the process of step S200 is performed multiple times at the same temperature, the heating temperature may be increased and step S200 may be performed. Furthermore, energy consumption for heating can be reduced compared to the aspect in which the heating temperature is changed each time step S200 is performed.

D2) In this way, in the process of step S200 executed the mth time (m is a positive integer) and the process of step S200 executed the nth time (n is a positive integer smaller than m), the heating temperature of step S200 executed the mth time may be set higher than the heating temperature of step S200 executed the nth time. This allows the heating temperature to be increased depending on the transport environment and situation.

D3) In the third embodiment described above, the heating temperature in step S200C may be set higher than the heating temperature in the previous step S200C. Compared to the previous step, the second workpiece expands more. Therefore, compared to the previous step, the first workpiece can be transported while leaving behind the workpiece other than the first workpiece.

D4) In the above embodiment, the workpieces 10 and 10C are stacked vertically. Note that, for example, multiple workpieces may be stacked horizontally. Each workpiece may have a convex portion on one side and a concave portion on the other side, and two adjacent workpieces may be in contact with each other with the concave portion of one workpiece fitting into the convex portion of the other workpiece.

Then, of the multiple workpieces, a first workpiece that is located at one end and a second workpiece adjacent to the first workpiece, the convex portion of the workpiece that has the convex portion of the other workpiece accommodated in the concave portion is heated, and the first workpiece is transported, leaving behind all the multiple workpieces except the first workpiece.

When one of the first and second workpieces has its convex portion received in its concave portion, the convex portion expands due to heating. A gap is created between the convex portion of the other workpiece and the surface of the concave portion of the other workpiece that has its convex portion received in its concave portion. As a result, the first workpiece can be transported, leaving behind the other workpieces.

D5) In the above embodiment, one workpiece 10 has one convex portion 11 and one concave portion 12, and the multiple workpieces 10 have the same shape. Note that one workpiece may have any number of concave portions and convex portions, such as one or more, for example, two, three, or four. The multiple workpieces may have different shapes, and for example, a workpiece having two concave portions and two convex portions and a workpiece having three concave portions and three convex portions may be mixed and stacked. In this case, the concave portion of one workpiece and the convex portion of the other workpiece are fitted together and are in contact with each other.

D6) In the first embodiment described above, the non-contact portion 130 where the first recess 121 and the second protrusion 112 are not in contact is heated. Note that in the heating of step S200, both the non-contact portion and the contact portion may be heated. Depending on the thermal conductivity of the material of the workpiece, either the non-contact portion or the contact portion may be heated. Depending on the state of engagement between the first recess and the second protrusion, the control unit may determine which portion to heat and heat. Also, the temperature of the non-contact portion is acquired by the temperature acquisition unit. Note that the temperature acquisition unit may acquire the temperature of the contact portion instead of the non-contact portion, and the temperature of any portion of the first workpiece may be acquired.

D7) In the above embodiment, heating is performed by radiating infrared rays. However, heating may be performed by a method other than radiating infrared rays. For example, the heating unit may be an electric heater, and heating may be performed by directly contacting an electric heating wire with the convex portion of one of the first and second workpieces that is received in the concave portion. The heating unit may be a coil, and heat may be generated in the workpiece that is receiving the convex portion of one of the first and second workpieces in the concave portion by contacting the coil with the convex portion of the one of the first and second workpieces that is received in the concave portion to generate an electric current.

D8) In the above embodiment, the material of the workpiece 10 is an iron plate, and the workpiece 10 is a magnetic body. Note that the material of the workpiece may be other than an iron plate, for example, aluminum, titanium, resin, etc. The workpiece does not have to be a magnetic body.

D9) In the above embodiment, an electromagnet 20a is provided on the conveyor belt 20 at the portion where the workpiece 10 is placed, and an electromagnet (not shown) is provided on the gripper 23 at the portion where the gripper 23 comes into contact with the first workpiece 101. Note that the conveyor belt does not necessarily have to have an electromagnet provided. For example, the conveyor belt may be provided with an adsorption device that adsorbs the workpiece by air, and the workpiece may be adsorbed to perform the first conveyance. Furthermore, a permanent magnet may be provided on the conveyor belt.

The gripping section does not have to be provided with an electromagnet. For example, the gripping section may be provided with a suction device that uses air to attract the workpiece, and the workpiece may be gripped by being attracted to the gripping section.

D10) In the above embodiment, multiple workpieces are transported by a conveyor belt. Note that multiple workpieces may be transported by something other than a conveyor belt, for example by a pallet.

D11) In the above embodiment, the heating temperature and time are determined by the control unit 25. Note that the heating temperature and time may be determined by the user, and the user may input the heating temperature and time to the control unit.

Information on the size, thickness, thermal conductivity, etc. of the first workpiece 101 is input in advance by the user to the control unit 25. Note that, for example, the conveying device may be equipped with a camera, and the control unit may receive information on the workpiece acquired by the camera and determine information on the size, thickness, thermal conductivity, etc. of the first workpiece.

D12) In the above embodiment, the temperature acquisition unit 22 is a thermocamera. Note that the temperature may be acquired by a device other than a thermocamera, for example, a thermometer that contacts the first workpiece, or may be acquired by a laser.

D13) In the above embodiment, the weight sensor unit 24 was provided in the conveying device 1. The weight sensor unit may also be provided in the gripping unit. In this case, the control unit may determine whether the weight acquired by the weight sensor unit is the weight of one piece of work.

D14) In the above embodiment, the gripping unit 23 grips the first workpiece 101 after the first workpiece 101 is heated. Note that the gripping unit may grip the first workpiece before the first workpiece is heated.

D15) In the first embodiment, the conveying device 1 has three heating sections 21, and in the third embodiment, it has two heating sections 21. Note that the number of heating sections may be any number, such as one, four, or five.

D16) The heating unit may be movable in the X-axis, Y-axis, and Z-axis of FIG. 1 by the control unit. For example, when heating the first workpiece, the heating unit is brought closer to the first workpiece. When the control unit determines that the temperature of the first workpiece has reached a predetermined temperature, the heating unit may be moved in a direction away from the first workpiece.

D17) In the above embodiment, the conveying device 1 is equipped with a temperature acquisition unit 22. Note that the conveying device does not have to be equipped with a temperature acquisition unit. In this case, steps S300 and S400 may be omitted, and the process may proceed to the next step when the control unit determines that the first workpiece has been heated by the heating unit for a predetermined time.

D18) In the first embodiment, if the temperature acquired by the temperature acquisition unit 22 is a predetermined temperature, the temperature acquisition unit 22 transmits a signal to that effect to the control unit 25. Then, in step S400, the control unit 25 determines whether the temperature of the non-contact unit 130 has reached the predetermined temperature. Note that if the temperature acquired by the temperature acquisition unit is equal to or higher than the predetermined temperature, a signal to that effect may be transmitted from the temperature acquisition unit to the control unit, and in step S400, the control unit may determine whether the temperature of the non-contact unit is equal to or higher than the predetermined temperature, and if it is equal to or higher than the predetermined temperature, the process may proceed to step S500.

The temperature acquisition unit does not have to constantly acquire the temperature of the non-contact part, and may acquire the temperature of the first workpiece at regular intervals.

The present disclosure is not limited to the above-mentioned embodiments, examples, and modifications, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each form described in the Summary of the Invention column can be replaced or combined as appropriate to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

1...conveying device, 10, 10C...workpiece, 11, 11C...projection, 12, 12C...recess, 20...conveying belt, 20a...electromagnet, 21...heating section, 22...temperature acquisition section, 23...gripping section, 24...weight sensor section, 25...control section, 101, 101C...first workpiece, 102, 102C...second workpiece, 103...third workpiece, 111, 111C...first projection, 112, 112C...second projection, 113...third projection, 121, 121C...first recess, 122, 122C...second recess, 123...third recess, 130...non-contact section, 140...contact section, 300...gap, A...arrow

Claims (7)

A method for transporting a workpiece, comprising the steps of:
(a) preparing a plurality of workpieces each having a convex portion on one surface and a concave portion on the other surface at a position corresponding to the convex portion, the plurality of workpieces being in contact with each other such that the concave portion of one workpiece fits into the convex portion of the other workpiece;
(b) heating the convex portion of one of the first workpieces, which is a workpiece located at an end of the plurality of workpieces, and the second workpiece adjacent to the first workpiece, in which the convex portion of one of the workpieces is received in the concave portion;
(c) after the step (b), a step of transporting the first workpiece while leaving the workpieces other than the first workpiece among the plurality of workpieces;
(d) repeating the steps (b) and (c);
Equipped with
The step (d)
The heating temperature of the step (b) performed in the mth time (m is a positive integer) is set to be higher than the heating temperature of the step (b) performed in the nth time (n is a positive integer smaller than m).
Method of transporting the workpiece. The workpiece transport method according to claim 1,
In the step (a), the recess of the first workpiece receives the protrusion of the second workpiece,
The step (b)
A step of heating the non-contact portion of the concave portion of the first workpiece, the non-contact portion being a portion of the concave portion of the first workpiece that is in contact with the convex portion of the second workpiece and a non-contact portion being a portion of the concave portion that is not in contact with the convex portion of the second workpiece.
Method of transporting the workpiece. The workpiece transport method according to claim 1 ,
In the step (d), the step (b) is performed at a temperature set higher than the heating temperature in the previous step (b).
Method of transporting the workpiece. The workpiece transport method according to claim 1,
The step (b) is a step of heating the convex portion by radiating infrared rays.
Method of transporting the workpiece. The workpiece transport method according to claim 1,
The step (a) is a step of preparing the plurality of workpieces stacked in the vertical direction, in which the concave portion of the upper workpiece in the vertical direction and the convex portion of the lower workpiece in the vertical direction are fitted into each other among two adjacent workpieces, and the plurality of workpieces are stacked in such a state that:
The step (b) is a step of heating the convex portion of a first workpiece that is located at the top in a vertical direction among the plurality of workpieces.
Method of transporting the workpiece. The workpiece transport method according to claim 1,
The step (a) is a step of preparing the plurality of workpieces stacked in the vertical direction, in which the plurality of workpieces are stacked in a state in which the convex portion of the upper workpiece in the vertical direction and the concave portion of the lower workpiece in the vertical direction are fitted into each other among two adjacent workpieces,
The step (b) is a step of heating the convex portion of a second workpiece overlapping a first workpiece located at the top in a vertical direction among the plurality of workpieces.
Method of transporting the workpiece. A workpiece conveying device,
The workpieces are a plurality of workpieces each having a convex portion on one surface and a concave portion on the other surface at a position corresponding to the convex portion, and among the plurality of workpieces, two adjacent workpieces are in contact with each other such that the concave portion of one workpiece fits into the convex portion of the other workpiece,
The conveying device is
a heating unit that heats the convex portion of one of the first workpieces, which is a workpiece located at an end, and a second workpiece adjacent to the first workpiece, the convex portion of which is received in the concave portion; and
A gripping portion capable of gripping the first workpiece;
A control unit that controls the conveying device;
Equipped with
The control unit is
The gripping unit conveys the first workpiece while leaving other than the first workpiece among the plurality of workpieces;
Heating the protrusion by the heating unit; and
After heating the protrusion, a process of conveying the first workpiece to the gripping unit while leaving the first workpiece among the plurality of workpieces on the gripping unit;
Repeat the process.
In the repeated processing, a temperature of the heating of the convex portion performed in an m-th time (m is a positive integer) is set to be higher than a temperature of the heating of the convex portion performed in an n-th time (n is a positive integer smaller than m).
Work transport device.

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