JP6364376B2 - Transport device - Google Patents

Description

  The present invention relates to a conveying device for conveying a workpiece from a heating process to a pressing process during press molding.

In general, in a forming process in which a sheet-like workpiece is formed into a predetermined shape by press forming or the like, a transfer clamp that is movable in the front-rear direction of a forming machine such as a press machine is used. A series of processes related to the molding process such as a heat process and a press process is performed with the work held (see Patent Document 1).
Usually, the transfer clamp is opened and closed at the bases disposed on both the left and right sides of the workpiece, a plurality of arms extending from the base toward the workpiece in a substantially horizontal direction, and the ends of the arms. And a clip provided in a possible manner. The arm is attached to the base at a fixed angle, and the clip is opened and closed by a cylinder or the like. The transport clamp supports and transports the work so that the work is suspended between the left and right arms while sandwiching the side edge of the work with the clip.
However, the workpiece suspended between the left and right arms may be drastically drooped by its own weight, particularly in the left-right intermediate portion, in a softened state after the heat treatment. In such a case, molding defects frequently occur. Thus, for example, as shown in Patent Document 2, an attempt has been made to pull the workpiece in which the intermediate portion hangs down in the left-right direction by contracting the arm.
Further, when the arm is provided with a mechanism such as expansion / contraction or movement, if the heat treatment is included as a series of processes particularly related to the molding process, the durability of the arm becomes a problem. Attempts have been made as shown in.

JP-A-2005-007441 Japanese Patent Laid-Open No. 11-0777817 Japanese Patent Laid-Open No. 10-193030

However, as shown in Patent Document 2, when the arm is contracted and the work is pulled in the left-right direction to apply tension, a problem of forming defects different from the case where the intermediate portion of the work hangs down occurs. was there. That is, when the intermediate part of the workpiece hangs down, the workpiece sags and wrinkles at the suspended part, and when the workpiece is pulled in the left-right direction, tension is applied to the workpiece during pressing. As a result, the workpiece is torn.
In order to suppress molding defects such as wrinkles and tears as described above, the vertical position of the arm is appropriately controlled so that an optimal tension is applied to the workpiece during molding, and the workpiece is controlled by the arm whose vertical position is appropriately controlled. Is required to be supported at an appropriate gripping position. However, as described above, if a complicated mechanism capable of appropriately controlling the vertical position is incorporated into the arm, the durability becomes difficult.
The present invention has been made paying attention to such problems existing in the prior art. The object is to provide a transport device that can improve the degree of freedom in moving the arm that suspends the workpiece and can further control the movement while further improving the durability. There is to do.

As a means for solving the above-mentioned conventional problems, the invention of the conveying device according to claim 1 is a press process after a workpiece made of a synthetic resin sheet material having a quadrangular shape is heated and softened in a heating process. In a molding process in which a press mold is sandwiched between an upper mold and a lower mold and press-molded into a predetermined shape, the transport apparatus is used to transport the work from the heating process to the press process, A machine frame that has a quadrilateral shape when viewed, and a plurality of robot arms that are extended from the four sides of the machine frame and suspend the work inside the machine frame by gripping the periphery of the work. The robot arm includes an arm main body configured to be extendable and contractable in a longitudinal direction by a telescopic structure formed by fitting a plurality of cylinders having different diameters, and the arm. A clip that is attached to the front end of the main body and can be opened and closed, a turning mechanism that pivots the arm body up and down with respect to the machine frame, an opening and closing mechanism that opens and closes the clip, and the arm body A detecting means for detecting a load exerted on the workpiece suspended inside the machine frame at the time of press molding, and according to the load detected by the detecting means. In the pressing step, the plurality of robot arms rotate the arm main body by the rotating mechanism and / or expand / contract by the expanding / contracting mechanism to raise and lower the gripping position of the peripheral edge of the workpiece by the clip. The load is controlled to a desired value by appropriately changing the direction and the horizontal direction, and the robot arm Each of the rotation mechanism, the expansion / contraction mechanism, and the opening / closing mechanism is driven by a servo motor under numerical control, and the servo motor of each mechanism is not affected by heating during the heating process. The gist is that the servo motor is installed outside the heating range by being arranged at the base end of the arm body.
The invention according to claim 2 is the gist of the invention of the transfer apparatus according to claim 1, wherein the machine frame is configured such that one side on the traveling side in the transfer direction of the workpiece can be opened and closed. To do.
According to a third aspect of the present invention, in the invention of the transfer device according to the first or second aspect, the expansion / contraction mechanism of the robot arm is a servo motor disposed at a base end portion of the arm body. An extension structure that moves the cylindrical body constituting the arm body in an extension direction from the proximal end side to the distal end side of the arm body by transmitting a driving force to the entire arm body, and the arm body And a contraction structure that moves the cylinder body in a contraction direction from the distal end side to the proximal end side of the arm main body, and is provided at the proximal end portion of the arm main body as the extension structure by the servo motor. A rotating rotator that is driven to rotate, and the extending rotator while moving in the contraction direction when the extending rotator is rotated from the extending rotator toward the distal end side of the arm body. A linear member for extension wound around the body, and a direction changing member that changes the movement of the linear member for extension in the contraction direction to the movement in the extension direction when winding the rotary member for extension. And an extension transmission member that moves the cylinder in the extension direction by transmitting the force from the extension linear body that moves in the extension direction by the direction changing member to the cylinder, and As a contraction structure, a contracting rotator disposed at a base end portion of the arm body and driven to rotate by the servo motor, and the contraction rotator being drawn out from the contracting rotator toward the distal end side of the arm body. A contracting linear body wound around the contracting rotating body while moving in the contracting direction by rotating the rotating body for rotation, and transmitting a force from the contracting linear body moving in the contracting direction to the cylindrical body Shrinkage that moves the cylinder in the shrinking direction It is summarized as that comprises a transmitting member.

[Action]
In the transfer device of the present invention, a plurality of robot arms for suspending a workpiece are extended from each of the four sides constituting the machine frame, and the workpiece can be suspended from four directions, front, rear, left and right. Forming defects caused by undesired deformation of the held work are suppressed.
The plurality of robot arms that suspend the workpiece have their respective arm bodies rotated with respect to the machine frame by a rotation mechanism and expanded and contracted by an expansion / contraction mechanism so that the gripping position of the periphery of the workpiece by the clip can be determined. It can be appropriately changed in the vertical direction and the horizontal direction. For this reason, the plurality of robot arms have improved freedom of movement, and it is possible to realize suspension of the workpiece by appropriate tension.
Since each of the robot arm rotation mechanism, the expansion / contraction mechanism, and the opening / closing mechanism is driven by a servo motor under numerical control, it is possible to appropriately control the movement. The servo motor of each mechanism is installed outside the heating range by being arranged at the base end portion of the arm main body so as not to be affected by heating, so that durability against heating can be improved.
Further, when the machine frame is configured to be openable and closable on one side that is the traveling side of the workpiece in the conveyance direction, collision between the machine frame and the press mold during conveyance is avoided.
Further, by providing the servo motor at the base end portion of the arm body, the means for transmitting the driving force of the servo motor to the distal end portion of the arm body at the time of expansion / contraction, as the expansion / contraction mechanism, A shrink structure is incorporated. The elongating structure is composed of an elongating rotating body that is driven to rotate by the servo motor, an elongating linear body that is wound around the elongating rotating body, and a movement of the elongating linear body in the contracting direction during winding. A direction changing member that changes the direction of movement in the extending direction, and an extension transmitting member that transmits the force from the extending linear body moving in the extending direction to the cylinder of the arm body. The contraction structure includes a contraction rotating body that is rotationally driven by the servomotor, a contraction linear body that is wound around the contraction rotation body, and a force from the contraction linear body that moves in the contraction direction during winding. It is comprised by the contraction transmission member which transmits to the said cylinder of the said arm main body. That is, the extension structure and the contraction structure can extend or contract the arm body only by winding the extension linear body or the contraction linear body, so that the structure is simple and the durability is impaired. And accurate numerical control becomes possible.
In addition, by generating a molding model by press molding simulation as detection means, it is possible to suitably detect the load exerted on the workpiece during press molding, and the workpiece is placed in the press mold as the load. By analyzing the force drawn into the workpiece and the stress state of the workpiece, it is possible to reduce the excess portion of the molding on the workpiece.

〔effect〕
According to the present invention, it is possible to provide a transfer device capable of improving the degree of freedom in moving the arm that suspends the workpiece and further improving the durability while allowing the movement to be appropriately controlled. I can do it.

(A) which shows the conveying apparatus of embodiment is a top view, (b) is a front view. (A) of the robot arm of embodiment is a top view, (b) is a front view, (c) is a side view. (A) which shows an arm main body is a top view of a contracted state, (b) is a front view, (c) is a top view of an expansion | extension state. It is a schematic diagram which shows the expansion | extension of the 1st step of the arm main body by an expansion-contraction mechanism by planar view, Comprising: (a) is the state before expansion | extension, (b) is the state in expansion | extension, (c) is the state expanded to the maximum value . It is a schematic diagram which shows the expansion | extension of the 2nd step of the arm main body by an expansion-contraction mechanism by planar view, Comprising: (a) is the state before expansion | extension, (b) is the state in expansion | extension, (c) is the state expanded to the maximum value . It is a schematic diagram which shows the shrink operation | movement of the arm main body by a shrinkage | contraction mechanism by planar view, Comprising: (a) is the state before shrinkage | contraction, (b) is in the state which is shrinking, (c) is the state which shrinkage was completed. It is a schematic diagram which shows rotation of the arm main body by a rotation mechanism by a side view, (a) is a horizontal state, (b) is the state rotated to the up-down direction. It is a schematic diagram which shows opening and closing of the clip by an opening and closing mechanism in a side view, where (a) is a state where the clip is closed, and (b) is a state where the clip is open. The schematic diagram which shows the shaping | molding process of embodiment. It is a schematic diagram which shows the suspension of the workpiece | work by a conveying apparatus, Comprising: (a) is the state of a heating process, (b) is the state which expanded and contracted and rotated the arm main body at the press process, (c) is a type | mold at the press process. The state immediately before clamping, (c) is the mold clamped state in the pressing process.

An embodiment embodying the present invention will be described with reference to the drawings.
[Conveyor]
The conveying apparatus of this embodiment is used to convey a workpiece from a heating process to a pressing process in a forming process by press molding.
As shown in FIGS. 1A and 1B, the transport apparatus 1 includes a machine frame MF and a plurality of the robot arms RA.
The machine frame MF is a square in a plan view by a front side 4 on one side which is a traveling side in the transport direction by the transport device 1, a rear side 5 facing the front side 4, and a pair of left and right side sides 6. It is formed so as to form a shape. The front side 4 is composed of a pair of divided sides 4A divided at the center in the longitudinal direction. The pair of divided sides 4A are rotatably connected to the distal ends of the side sides 6 at their base ends. The machine frame MF is configured such that the front side 4 can be opened and closed by turning the pair of divided sides 4A upward and flipping them up.
The robot arm RA is extended toward the inside of the machine frame MF from the front side 4, the rear side 5 and the pair of left and right side edges 6 constituting the machine frame MF. The plurality of robot arms RA grip a workpiece W made of a synthetic resin sheet material having a quadrangular shape in a plurality of locations from the front, rear, left and right directions.

In the transport apparatus 1, the number of the robot arms RA provided per side of the machine casing MF is preferably 2 or more, more preferably 2 or more and 10 or less, and even more preferably 4 The number is 8 or less. If the number of robot arms RA provided on one side of the machine frame MF is too small, a portion of the work W that is not suspended by the robot arm RA may drastically hang down, which may cause molding defects. If the number of robot arms RA is too large, the transfer device 1 may become heavy, and movement during transfer may not be smooth.
Further, the number of the robot arms RA is not limited to the same number on each side of the machine casing MF, but may be different on each side. In the present embodiment, four robot arms RA are provided on each of the front side 4 and the rear side 5, and six robot arms RA are provided on each of the pair of left and right sides 6.

[Robot arm]
The robot arm will be described in detail.
As shown in FIGS. 2A to 2C, the robot arm RA is for gripping the workpiece W to be heat-treated, and is provided on the arm main body 11 and the tip of the arm main body 11. And a clip 12 attached thereto, and is attached to the machine frame MF at the base end portion of the arm main body 11.
The arm body 11 is configured to be extendable and contractible in the longitudinal direction. The clip 12 is configured to be openable and closable by combining a pair of upper and lower clamping claws 12A so as to be capable of mutual rotation.
In addition, the robot arm RA includes an expansion / contraction mechanism that expands and contracts the arm body 11, a rotation mechanism that rotates the arm body 11 in the vertical direction with respect to the machine frame MF, and an opening / closing mechanism that opens and closes the clip 12. It has a mechanism. These expansion / contraction mechanism, rotation mechanism, and opening / closing mechanism are each configured to be driven by servo motors M1, M2, and M3 under numerical control. The robot arm RA of the present embodiment includes a total of three servo motors M1, M2, and M3, one for each mechanism. The three servo motors M1, M2 and M3 are disposed at the base end of the robot arm RA (arm body 11).

The robot arm RA includes an expansion / contraction mechanism driven by a servo motor M1, and the position of the clip 12 in the longitudinal direction of the arm main body 11 (front / rear position) can be freely adjusted by extending / contracting the arm main body 11. It is possible to change. The robot arm RA includes a rotation mechanism driven by a servo motor M2, and the vertical position of the clip 12 is obtained by rotating the arm body 11 in the vertical direction with respect to the machine frame MF. Can be changed freely. That is, the robot arm RA provided with the expansion / contraction mechanism and the rotation mechanism can freely change the position of the clip 12 back and forth and up and down by extending and rotating the arm body 11. Improvements in freedom of movement are achieved.
Further, the robot arm RA is configured to hold or release the workpiece with the clip 12 by opening and closing the pair of clamping claws 12A by an opening / closing mechanism driven by the servo motor M3.
Each of the expansion / contraction mechanism, the rotation mechanism, and the opening / closing mechanism is under numerical control in which the servo motors M1, M2, and M3 for driving the respective operations are commanded by numerical information. It is possible to control.
The servo motors M1, M2, and M3 for driving the mechanisms are respectively disposed at the base end portion of the robot arm RA (arm body 11). When a workpiece to be transported is installed, it is installed outside the heating range of a heat source for heating the workpiece, is not affected by heating, and is improved in durability against heating. Furthermore, the servo motors M1, M2, and M3 that drive the respective mechanisms are covered with a heat shield plate, thereby further improving durability against heating.

[Arm body]
The arm body 11 will be described.
As shown in FIGS. 3A to 3C, the arm body 11 is composed of a plurality of cylindrical bodies, that is, a bottom tube 13, a middle tube 14, and a top tube 15 formed in a substantially square cylindrical shape. ing. The bottom tube 13, the middle tube 14, and the top tube 15 have different diameters, the bottom tube 13 has the largest diameter, the middle tube 14 has the diameter next to the bottom tube 13, and the top tube 15 is the thinnest. It is the diameter.
The bottom tube 13 and the middle tube 14 have a shape in which most of the upper wall is cut open so as to provide an expansion / contraction mechanism to be described later.
Sliding guide rails (not shown) are provided between the bottom tube 13 and the middle tube 14 and between the middle tube 14 and the top tube 15, respectively. By providing the sliding guide rail, the arm body 11 can smoothly slide the middle tube 14 with respect to the bottom tube 13 and the top tube 15 with respect to the middle tube 14 smoothly. It is slidable.

The bottom tube 13, the middle tube 14, and the top tube 15 constitute a telescopic structure by fitting together so that the bottom tube 13, the middle tube 14, and the top tube 15 are in order from the base end side. To do.
The arm body 11 having the telescopic structure is brought into a contracted state by accommodating the top tube 15 in the middle tube 14 and accommodating the middle tube 14 in the bottom tube 13 (FIG. 3 (a)). The arm body 11 having the telescopic structure is brought into an extended state by pulling out the middle tube 14 from the inside of the bottom tube 13 and pulling out the top tube 15 from the inside of the middle tube 14 (FIG. 3 (b)).
In the arm body 11 adopting the telescopic structure, the shaft centers of the bottom tube 13, the middle tube 14, and the top tube 15 are substantially coincident (see FIG. 3C), and each cylindrical shape is expanded and contracted. Since the movement of the body and the occurrence of rattling between the cylindrical bodies are suppressed, the expansion and contraction can be performed smoothly.
In addition, when the middle tube 14 is pulled out from the bottom tube 13 by a predetermined length between the bottom tube 13 and the middle tube 14, the middle tube 14 withdrawn beyond the predetermined length is pulled out. An expansion stopper (not shown) for regulating the length of the middle tube 14 and a contraction for regulating the accommodation of the middle tube 14 longer than the predetermined length when the middle tube 14 is accommodated in the bottom tube 13 by a predetermined length. A stopper (not shown) is provided. Similarly, between the middle tube 14 and the top tube 15, an extension stopper (not shown) that restricts drawing of the top tube 15 longer than a predetermined length, and the top tube 15 longer than a predetermined length. A shrinking stopper (not shown) for restricting the housing of the container is provided.

[Extension mechanism]
An expansion / contraction mechanism for expanding / contracting the arm body 11 will be described.
The expansion / contraction mechanism transmits the driving force by the servo motor M1 disposed at the base end portion of the arm main body 11 to the entire arm main body 11 to expand / contract the arm main body 11. That is, as described above, since the servo motor M1 is disposed at the base end portion of the arm body 11 so as not to be affected by heating, the expansion / contraction mechanism is configured so that the entire arm body 11 is moved. Is provided to transmit the driving force of the servo motor M1 to the tip of the arm body 11 in order to smoothly expand and contract the arm.
The expansion / contraction mechanism includes an extension structure and a contraction structure. The extending structure is a structure for moving the cylindrical body (the middle tube 14 and the top tube 15) constituting the arm body 11 in the extending direction from the proximal end side to the distal end side of the arm body 11. . The contraction structure is a structure for moving the cylindrical body (the middle tube 14 and the top tube 15) constituting the arm main body 11 in the contraction direction from the distal end side to the proximal end side of the arm main body 11. is there.

[Extension structure]
FIGS. 4A to 4C and FIGS. 5A to 5C are schematic diagrams showing the configuration in a simplified manner for easy understanding of the elongated structure.
At the base end portion (bottom tube 13) of the arm body 11, a drum 21 and an extension guide pulley 22 are disposed as the extension rotor 20.
An extension linear body 23 is wound on the peripheral surface of the drum 21, and the extension linear body 23 is extended from one end of the drum 21 and is extended to the extension guide pulley 22. It is extended and extended toward the front end side of the arm body 11 from the extending guide pulley 22. Specifically, a wire rod such as an iron wire or a steel wire is spirally wound on the peripheral surface of the drum 21, and both end portions of the wire rod are respectively extended from both left and right ends in the axial direction of the drum 21. It has a form, and one end of the both ends of the wire is used as the elongated linear body 23. In addition, let the other end part be the wire 30 for shrinkage mentioned later among the both ends of this wire.
When the drum 21 is connected to the servo motor M1, the drum 21 is rotated in a predetermined direction or a direction opposite to the predetermined direction around the axis. Then, when the drum 21 rotates in a predetermined direction, the linear member 23 for extension, which is one end portion of the wire rod, moves in a direction (contraction direction) from the distal end side to the proximal end side of the arm body 11, It is wound on the drum 21 of the extending rotating body 20.
In addition, as the wire used as the linear member 23 for extension, a flexible wire made of a metal material such as carbon steel or stainless steel, or a flexible material made of a fiber material such as carbon fiber, glass fiber, or chemical fiber. However, from the viewpoint of imparting high heat resistance and durability, it is desirable to use a wire made of a metal material (iron cord or steel cord).

A first direction changing member 24 composed of a pulley is rotatably attached to a portion of the bottom tube 13 that is closer to the side.
A disc-shaped first extension transmission member 25 is attached to the proximal end of the middle tube 14. Moreover, the 2nd direction change member 26 comprised with the pulley is attached to the front-end | tip part of the said middle tube 14 rotatably.
A rectangular second extending transmission member 27 is attached to the base end of the top tube 15.

The extension linear body 23 fed out from the extension guide pulley 22 of the extension rotary body 20 toward the distal end side of the arm body 11 first extends toward the first direction changing member 24. By being hung on the first direction changing member 24, the direction is changed by the first direction changing member 24 and extends toward the base end side of the arm body 11.
The extending linear body 23 extending toward the base end side of the arm body 11 is then hung on the first extending transmission member 25, and the first extending transmission member 25 has a disk shape. After being converted, the arm body 11 extends toward the distal end side.
The extending linear body 23 extending toward the distal end side of the arm main body 11 is hung on the second direction changing member 26, is changed in direction by the second direction changing member 26, and the base of the arm main body 11 is changed. It extends toward the end, and its tip is connected and fixed to the second extension transmitting member 27.
That is, the linear member 23 extended from the extension guide pulley 22 reaches the second extension transmission member 27 through the first direction changing member 24 and the second direction changing member 26. The first direction change member 24 and the second direction change member 26 are stretched so as to follow a path detouring to the first extension transmission member 25.

[Extension]
An extension operation of the arm body 11 by the extension structure will be described.
As shown in FIGS. 4A to 4C, the arm main body 11 is extended in the first stage in which the middle tube 14 is pulled out from the bottom tube 13, and in FIGS. 5A to 5C. As shown, it is possible to perform a second-stage extension in which the top tube 15 is pulled out from the middle tube 14.

In the first stage of extension, the servo motor M1 rotates the drum 21 of the extension rotary body 20 in a predetermined direction, and winds the extension linear body 23 on the drum 21 (FIG. 4A). )reference). The extending linear member 23 wound on the drum 21 moves in the contraction direction of the arm body 11 between the extending guide pulley 22 and the first direction changing member 24, and the first direction changing member If it exceeds 24, the direction is changed by the first direction changing member 24, and the space between the first direction changing member 24 and the first extension transmitting member 25 is directed from the distal end side to the proximal end side of the arm body 11. It moves in the direction (extension direction) (see FIG. 4B).
Here, the linear member 23 for extension stretched between the first direction change member 24 and the second direction change member 26 is detoured around the first extension transmission member 25. Therefore, the first extending transmission member 25 is in a state where it can receive the tension from the extending linear body 23. Further, the first extension transmission member 25 and the second direction changing member 26 are provided at the proximal end portion and the distal end portion of the middle tube 14 which are the same member, and therefore the distance between them. Is in a state of being kept constant without changing. Similarly, since the extension guide pulley 22 and the first direction changing member 24 are provided on the bottom tube 13 which is the same member, the distance between them is kept constant without change. Is in a state. Furthermore, the first extension transmission member 25 is movable in the direction in which the middle tube 14 to which the first extension transmission member 25 is attached is pulled out from the bottom tube 13. The movement in the extension direction is allowed.
Accordingly, when the linear member 23 for extension is wound on the drum 21, the linear member 23 for extension extends between the first direction change member 24 and the first extension transmission member 25. Tension is applied to the first extension transmission member 25 while moving in the extension direction of the main body 11. At this time, the distance between the extension guide pulley 22 and the first direction change member 24 is kept constant, and the distance between the first extension transmission member 25 and the second direction change member 26 is kept constant. The extension linear body 23 is in a slacked state, and the distance between the first direction change member 24 and the first extension transmission member 25 is reduced by the amount wound on the drum 21. As a result, the first extension transmission member 25 moves in the extension direction of the arm body 11, and the force for moving the first extension transmission member 25 is transmitted to the middle tube 14, and the middle tube 14 is The bottom tube 13 is drawn out.
In the first-stage extension, the maximum value is obtained when the middle tube 14 is pulled out of the bottom tube 13 by the extension stopper (see FIG. 4C). Then, when it is necessary to further extend the arm body 11 beyond the maximum value of the first stage extension, the second stage extension is performed.

In the extension of the second stage, the servo motor M1 rotates the drum 21 in a predetermined direction on the proximal end side of the arm body 11 with respect to the second direction changing member 26, as in the first stage. By doing so, the extending linear body 23 is wound on the drum 21 through the first extending transmission member 25, the first direction changing member 24, and the extending guide pulley 22. However, since the extension in the first stage has the maximum value in the extension in the second stage, the distance between the first direction change member 24 and the first extension transmission member 25 is kept constant. It is in a lean state.
In the extension in the second stage, the extension linear body 23 first moves between the first extension transmission member 25 and the second direction changing member 26 in the contraction direction of the arm body 11. When the linear member for extension 23 exceeds the second direction changing member 26, the direction is changed by the second direction changing member 26, and the second direction changing member 26 and the second extension transmitting member 27 are A tension is applied to the second extension transmission member 27 while moving in the extension direction of the arm body 11 (see FIG. 5A).
Here, as described above, the distance between the first extension transmission member 25 and the second direction changing member 26 is kept constant. Further, the second extension transmission member 27 is movable in the direction in which the top tube 15 to which the second extension transmission member 27 is attached is pulled out from the middle tube 14. The movement in the extension direction is allowed.
Therefore, when the linear member for extension 23 is wound on the drum 21, the linear member for extension 23 and the second direction changing member 26 and the second part are wound by the amount wound on the drum 21. The distance from the extension transmission member 27 is reduced. As a result, a force for pulling the second extension transmission member 27 in the extension direction of the arm body 11 is applied to the second extension transmission member 27 by the extension linear body 23, and the second extension transmission member 27 is attached to the arm body 11. Move in the extension direction. Then, the force for moving the second extension transmitting member 27 is transmitted to the top tube 15 and the top tube 15 is pulled out from the middle tube 14 (see FIG. 5B).

In the second stage of extension, the maximum value is obtained when the extension of the top tube 15 from the middle tube 14 is regulated by the extension stopper (see FIG. 5C). That is, the maximum value of the extension of the arm body 11 is the state where the extension of the first stage reaches the maximum value and the extension of the second stage reaches the maximum value.
As described above, the extension amount of the arm main body 11 is adjusted by the winding amount of the extension linear body 23 around the drum 21 by the servo motor M1. Since the servo motor M1 is under numerical control as described above, the extension amount of the arm body 11 can also be controlled. That is, if the extension amount of the arm body 11 reaches a desired value, the first stage extension can be stopped before reaching the maximum value, and the second stage extension is maximum. It is possible to stop before the value is reached.
As described above, the extending linear body 23 is one end of the linear body extended from one end of the drum 21, and the other end of the drum 21 The shrinkable linear body 30 which is the other end is extended. Then, the contracting linear body 30 is drawn out from the drum 21 by the amount corresponding to the winding linear body 23 wound on the drum 21, thereby clogging the extending linear body 23. Looseness is suppressed. Further, the arm main body 11 is provided with a slack preventing structure (not shown), so that slack of the extending linear body 23 is suitably prevented.

[Shrink structure]
FIGS. 6A to 6C are schematic views showing the configuration in a simplified manner for easy understanding of the contraction structure.
A contracting rotator 28 including a drum 21 and a contracting guide pulley 29 is disposed at the base end portion (bottom tube 13) of the arm body 11. A contracting linear body 30 is wound on the peripheral surface of the drum 21, and the contracting linear body 30 is extended from the other end of the drum 21, and the contracting guide pulley 29. And is extended from the contraction guide pulley 29 toward the distal end side of the arm body 11. And the front-end | tip of this linear body 30 for shrinkage | contraction is connected and fixed to the said transmission member 27 for 2nd expansion | extension used also as a transmission member for shrinkage | contraction.
The drum 21 of the expansion rotor 20 is shared with the drum 21 of the contraction rotor 28. Therefore, the expansion rotating body 20 and the contraction rotating body 28 rotate in synchronization with each other by sharing the drum 21 that is rotationally driven by the same servomotor M1, M2, M3.
Further, as described above, the contracting linear body 30 is the other end of the both ends of the wire rod extended from the left and right ends in the axial direction of the drum 21, and One end part is the linear body 23 for extension. That is, the extending linear body 23 and the contracting linear body 30 correspond to both ends of the same wire wound spirally on the peripheral surface of the drum 21, respectively. Therefore, the rotation direction for the drum 21 (the extending rotating body 20) to wind up the extending linear body 23 is the rotation for the drum 21 (the contracting rotating body 28) to feed the contracting linear body 30. The drum 21 (the contracting rotator 28) is wound in the same direction, and the rotating direction in which the drum 21 (the contracting rotator 28) winds the contracting linear body 30 is that the drum 21 (the expanding rotator 20) feeds the extending linear body 23. It becomes equal to the rotation direction.
As described above, the second extension transmission member 27 is used as an extension member, and is also used as a contraction transmission member. However, while the linear body for extension 23 is connected and fixed to the second extension transmission member 27 from the direction of pulling the top tube 15 in the extension direction, the linear body for contraction 30 is The difference is that the top tube 15 is connected and fixed to the second extension transmission member 27 from the direction in which the top tube 15 is pulled in the contraction direction.

[Shrinking operation]
The contraction operation of the arm body 11 by the contraction structure will be described.
In the contraction operation, the servo motors M1, M2, and M3 rotate the drum 21 of the contraction rotating body 28 in a direction opposite to a predetermined direction, and wind the contracting linear body 30 on the drum 21 ( (See FIG. 6 (a)).
The contracting linear body 30 wound on the drum 21 moves in the contracting direction of the arm body 11 between the contracting guide pulley 29 and the second extension transmitting member 27. Then, a tensile force acting in the contraction direction of the arm main body 11 is applied to the second extension transmission member 27 by the contraction linear body 30, and the second extension transmission member 27 receiving the tensile force is applied to the second extension transmission member 27. The arm body 11 moves in the contraction direction.

As the second extension transmitting member 27 moves, the top tube 15 to which the moving force is transmitted is drawn into the middle tube 14 and accommodated (see FIG. 6B). At this time, the extension rotator 20 and the contraction rotator 28 rotate in synchronization with each other, and the drum 21 (contraction rotator 28) winds the contraction linear body 30. The rotation direction is equal to the rotation direction for the drum 21 (extension rotary body 20) to feed out the extension linear body 23. That is, the drum 21 feeds out the extending linear body 23 in an amount equal to the amount of the contracting linear body 30 wound up. As a result, when the top tube 15 is accommodated in the middle tube 14, the extension of the extension linear member 23 causes the second direction change member 26 and the second extension transmission member 27 to move. The distance increases.
Further, the movement force of the second extension transmission member 27 is transmitted through the top tube 15 substantially simultaneously with or behind the accommodation of the top tube 15 in the middle tube 14. The middle tube 14 is drawn into and accommodated in the bottom tube 13 (see FIG. 6C). When the middle tube 14 is housed in the bottom tube 13, the first direction change member 24 and the first extension transmission member are brought out by feeding out the linear member 23 for extension from the drum 21. The distance to 25 increases.
Then, when the substantially entire top tube 15 is accommodated in the middle tube 14 and the substantially entire middle tube 14 is accommodated in the bottom tube 13, the contraction operation is completed.

[Rotation mechanism]
A turning mechanism for turning the arm body 11 will be described. FIGS. 7A and 7B are schematic views showing a simplified configuration in order to make the rotation mechanism easy to understand.
A mounting seat 31 having a substantially concave shape in plan view for mounting the arm body 11 is mounted and fixed inside the machine casing MF (see FIGS. 2A and 2C).
A pivot shaft 32 is attached to the arm body 11 so as to extend from the outer surface toward the side on both side surfaces of the base end portion. The arm main body 11 is pivoted to the attachment seat 31 by having the base end portion accommodated inside the attachment seat 31 and the rotation shaft 32 being rotatably inserted into the attachment seat. It is supported.
A bevel gear 33 is attached and fixed to one end of the rotating shaft 32 outside the one side wall of the attachment seat 31 (see FIGS. 2A and 7A). A fixing portion 31A extends from the tip of one side portion of the attachment seat 31, and the servo motor M2 is attached to the fixing portion 31A. The gear 34 attached to the tip of the shaft extending from the servo motor M 2 is meshed with the bevel gear 33.

The rotation mechanism includes the attachment seat 31, the rotation shaft 32, the bevel gear 33, the servo motor M2, and the like. When the servo motor M2 rotationally drives the gear 34, the bevel gear 33 meshing with the gear 34 rotates, and the rotation shaft 32 rotates with the rotation of the bevel gear 33. The said arm main body 11 fixed with respect to the said attachment seat 31 rotates to an up-down direction (refer FIG.7 (b)).
Since the servo motor M2 is under numerical control, the arm main body 11 can stop rotating at an arbitrary position by controlling the rotational drive of the gear 34. For this reason, the upper and lower positions of the clip 12 provided at the tip of the arm body 11 can be freely changed as desired.
In FIG. 7B, the arm main body 11 is rotated without being extended, but naturally the arm main body 11 can be extended and rotated.

The clip 12 is rotatably attached to the tip of the arm body 11. The turning mechanism has a detector (not shown) that detects the turning angle of the arm body 11.
Then, based on the detection result by the detector, the clip 12 is rotated horizontally with respect to the tip of the arm body 11 in accordance with the rotation of the arm body 11, so that the clip 12 is always horizontal. It is comprised so that it may become the direction opened and closed by direction.
That is, when the arm body 11 is rotated in the vertical direction, if the clip 12 is attached to the tip of the arm body 11 at a fixed angle, the gripped work is slipped by the clip 12 being directed downward. If the clip 12 falls or the clip 12 faces upward, a defect such as unintentionally pulling up the peripheral edge of the workpiece may occur. Thus, the clip 12 is rotatably attached to the tip of the arm body 11, and is configured to always open and close in a horizontal direction, thereby preventing the above-described problems.

[Opening and closing mechanism]
An opening / closing mechanism for opening and closing the clip 12 will be described. FIGS. 8A and 8B are schematic diagrams showing the configuration in a simplified manner for easy understanding of the opening / closing mechanism.
As described above, the opening / closing mechanism is provided with a driving force by the servo motor M3 disposed at the base end portion of the arm body 11 at the distal end of the arm body 11 so as not to be affected by heating. It is provided to transmit to the above-mentioned clip 12 and to open and close the clip 12.
The arm main body 11 is provided with a rotating shaft 35. The rotating shaft 35 is connected to the servo motor M3 via a pulley, a belt, or the like on the outer side at the base end of the arm body 11, and is rotated by the servo motor M3.

An operating body 36 that operates in accordance with the rotational drive of the rotary shaft 35 is provided at the tip of the rotary shaft 35. In the pair of upper and lower clamping claws 12 </ b> A constituting the clip 12, a crank 37 is installed between each base end and the operating body 36.
The opening / closing mechanism includes the rotating shaft 35, the crank 37, and the like. In the opening / closing mechanism, when the rotary shaft 35 is rotationally driven in a predetermined direction by the servo motor M3 under numerical control, the operating body 36 is drawn into the rotary shaft 35 at the tip of the rotary shaft 35. Operates as described. When the operating body 36 is operated, the crank 37 interlocked with the operating body 36 moves the clamping claws 12A and opens the clip 12. Further, when the rotary shaft 35 is rotationally driven in a direction opposite to a predetermined direction by the servo motor M3, the operating body 36 is operated so as to protrude from the rotary shaft 35 at the tip of the rotary shaft 35, and The crank 37 interlocked with the operating body 36 moves the clamping claw 12A and closes the clip 12.
The rotating shaft 35 has a telescopic structure so as not to affect the expansion and contraction of the arm main body 11, and is configured to be able to expand and contract in accordance with the expansion and contraction of the arm main body 11. Further, the rotary shaft 35 has a universal joint 38 at the distal end portion so as not to affect the rotation of the clip 12 with respect to the distal end of the arm body 11.

[Molding]
As shown in FIG. 9, the molding process using the conveying device includes a heating process using the heater 2 and a pressing process using the press mold 3 including the upper mold 3 </ b> A and the lower mold 3 </ b> B. The said conveying apparatus 1 is normally located in the place of a press process, and is comprised so that it may move between this press process and the said heating process.
As the heating step, first, the workpiece W is placed on the transport table 2A and transferred to the lower side of the heater 2 (arrow A in FIG. 9).
Subsequently, the said conveying apparatus 1 located in the place of the said press process moves upwards of the conveyance stand 2A (arrow B in FIG. 9). When the transport device 1 moves, the pair of divided sides 4A constituting the front side 4 of the machine frame MF are rotated so as to jump upward, so that the press mold 3 is moved during the movement. Configured to avoid collisions.
After being moved above the transfer table 2A, the transfer device 1 extends and rotates the arm body 11 of the robot arm RA, opens and closes the clip 12, and grips the peripheral edge of the workpiece W. The workpiece W is suspended inside the machine frame MF with all of the plurality of robot arms RA (see FIG. 10A).
Thereafter, the workpiece W is heated and softened by being heated by the heater 2 while being suspended from the transfer device 1. And the said workpiece | work W made into the heat softening state is conveyed by the said press process.
When the work W is heated by the heater 2, the position closest to the heater 2 that is a heat source (the tip of the robot arm RA) on the robot arm RA of the transfer device 1 is determined by the heater 2. Within the heating range and affected by heating. On the other hand, on the robot arm RA, servo motors M1, M2, and M3 for driving the expansion / contraction mechanism, the rotation mechanism, and the opening / closing mechanism are arranged at the base end of the arm body 11, that is, the position farthest from the heater 2 that is a heat source. It is installed. Therefore, even if the transport device 1 is used in the heating process, the servo motors M1, M2, and M3 are installed outside the heating range by the heater 2, and are not easily affected by heating. Certainty of operation is maintained.

As the press step following the heating step, the work W, which has been in a heat softened state, is suspended by the transfer device 1 and moved forward, thereby the press mold 3 is conveyed above the lower mold 3B (arrow C in FIG. 9).
In the conveyance, the conveyance device 1 stably suspends the workpiece W in a heat-softened state from the front, rear, left and right directions by the plurality of robot arms RA inside the machine frame MF. Furthermore, for example, when the degree of softening of the workpiece W is large, the arm main body 11 is contracted to suppress sagging of the intermediate portion of the workpiece W, and to prevent the workpiece W from being loosened or wrinkled. is there. Therefore, the transfer device 1 can lift and transfer the workpiece W in the heat-softened state with an appropriate tension by improving the degree of freedom in movement of the plurality of robot arms. Molding defects due to undesired deformation of W are suppressed.
Next, in the transfer device 1, the plurality of robot arms RA that grip the workpiece W rotate the arm main body 11 by the rotation mechanism and / or expand / contract by the expansion / contraction mechanism. The grip position of the periphery of the workpiece W by the clip 12 is appropriately changed in the vertical direction and the left and right (front and rear) directions (see FIG. 10B).
For example, as shown in FIG. 10B, in the case of a mold surface in which the deeply drawn portion is shifted to one side while the flat portion is present on the other side, the robot arm RA on the other side is the arm body 11. Is extended three-dimensionally and pivoted downward, so that the workpiece W is three-dimensionally suspended so as to substantially follow the mold surface, and excessive tension is applied to the workpiece W during pressing. The work W is prevented from being torn.
Thereafter, the upper die 3A is lowered with respect to the lower die 3B while the work W is suspended from the robot arm RA of the transfer device 1 (arrow D in FIG. 9). Here, the robot arm RA holds the peripheral edge portion of the workpiece W by the clip 12 until the lower mold 3B and the upper mold 3A of the press mold 3 are combined and immediately before the mold is clamped (FIG. 10). (See (c)).
That is, by suspending a workpiece in a heat-softened state three-dimensionally from the front, rear, left and right directions, substantially the entire workpiece W can be used for molding without waste.
Then, the grip of the peripheral edge of the work W by the clip 12 of the robot arm RA is released, and the lower mold 3B and the upper mold 3A of the press mold 3 are clamped to form the work W into a predetermined shape. (See FIG. 10D).
The workpiece W formed into a predetermined shape is taken out (arrow E in FIG. 9) after the press mold 3 is opened, and conveyed to the outside.

In the pressing step, as shown in FIG. 10B, the plurality of robot arms RA rotate the arm bodies 11 by the rotating mechanism and / or extend / contract by the expanding / contracting mechanism. The grip position of the periphery of the workpiece W by the clip 12 is appropriately changed in the vertical direction and the left and right (front and rear) directions. Due to the change in the gripping position of the workpiece W by the clip 12, the load exerted on the workpiece W suspended inside the machine frame MF can be suppressed to a desired value during the press molding.
That is, in the case of a normal pressing process, a plate-like clamp is provided at a distance from the periphery of the mold surface around the mold surfaces of the lower mold and the upper mold of the press mold. And the clamp for conveyance used in the normal press process releases the grip of the workpiece by placing the workpiece on the plate-shaped clamp after conveying the workpiece to above the lower mold, During molding, a plate-like clamp provided on the press mold holds the peripheral edge of the workpiece. However, the plate-like clamp in the normal pressing process does not have a function of causing the workpiece to follow a three-dimensional mold surface, but only has a function of holding the peripheral edge of the workpiece in a plane. Absent. Moreover, the normal conveyance clamp has only the function of conveying the workpiece to the upper part of the lower mold.
On the other hand, the transport device 1 not only transports the work W to above the lower mold, but also raises and lowers the gripping position of the peripheral edge of the work W by the clip 12 by the expansion and contraction and / or rotation of the arm body 11. By appropriately changing the direction and the left / right (front / rear) direction, the workpiece W has a function of being three-dimensionally suspended so as to follow the mold surface. Furthermore, the conveying device 1 can make the gripping position of the workpiece W by the clip 12 close to the peripheral edge of the mold surface by the expansion and contraction and / or rotation of the arm body 11. There is no need for a plate-like clamp as provided in the press mold. And if it is this normal press-molding die, since the plate-shaped clamp is provided at a distance from the periphery of the mold surface, the surplus part after molding becomes large. Since the gripping position of the workpiece W by the clip 12 is the closest position to the periphery of the mold surface, it is possible to minimize the excess portion after molding.

The forming process using the transport device 1 becomes more useful by detecting the load exerted on the workpiece W before actually performing the forming process. The load exerted on the workpiece W is obtained by executing a press molding simulation in advance using a computer device or the like and generating a molding model as an execution result.
That is, when the simulation is executed and the load exerted on the workpiece W is detected, the force with which the workpiece W is drawn into the press mold 3 during the press molding and the workpiece W during the press molding. It is possible to analyze the stress state. For this reason, in addition to reducing the load by suspending the workpiece W three-dimensionally so as to follow the mold surface, the force and amount that the workpiece W is drawn into the press mold 3 as the load, By analyzing the stress state of the workpiece, it is possible to reduce the excess portion of the molding on the workpiece.

[Modification]
The present invention is not limited to the configuration shown in the above embodiment, and the configuration can be changed as follows.
In the expansion / contraction mechanism, the extension structure and the contraction structure share the drum 21, but the present invention is not limited thereto, and the extension drum and the contraction drum may be provided separately. When the extension drum and the contraction drum are provided separately, when the winding direction of the linear body with respect to the drum is opposite to each other and the extension drum and the contraction drum rotate in the same rotation direction, The linear body may be wound up, and the other may be configured to feed out the linear body.
In the expansion / contraction mechanism, the plurality of cylindrical bodies are not limited to expand / contract with a telescopic structure. Good.
In the expansion / contraction mechanism, for example, a female thread groove is threaded on the inner peripheral surface of one cylindrical body, and a male thread groove is threaded on the outer peripheral surface of the other cylindrical body. You may comprise so that it may expand-contract by rotating a cylindrical body.
The opening / closing mechanism may be configured to open / close the clip by pulling with a linear body instead of the rotating shaft.

1: Conveying device, 2: Heater, 2A: Conveying table, 3: Press mold, 3A: Upper die, 3B: Lower die, MF: Machine frame, 4: Front side, 4A: Split side, 5: Rear side, 6: A pair of sides, W: Workpiece, P: Molded body, RA: Robot arm, 11: Arm body, 12: Clip, 12A: Holding nail, 13: Bottom tube, 14: Middle tube, 15: Top tube, M1: Servo motor for expansion / contraction mechanism, 20: Rotating body for expansion, 21: Drum (for expansion and contraction), 22: Guide pulley for expansion, 23: Linear body for expansion, 24: First direction change member, 25: first extension transmission member, 26: second direction change member, 27: second extension transmission member (contraction transmission member), 28: contraction rotating body, 29: contraction guide pulley, 30: contraction Linear body, M2: Servo motor for rotation mechanism, 3 : Mounting seat, 31A: fixed part, 32: rotating shaft, 33: bevel gear, 34: gear, M3: servo motor for opening / closing mechanism, 35: rotating shaft, 36: operating body, 37: crank, 38: free Fittings.

Claims (3)

Forming a workpiece made of synthetic resin sheet material that has a rectangular shape in a heating process and then softening it in the heating process, and then pressing it into a predetermined shape by sandwiching it between the upper mold and the lower mold of the press mold in the pressing process In processing, a transport device used to transport the workpiece from the heating step to the press step,
A machine frame that has a quadrilateral shape in plan view, and a plurality of robot arms that are extended from the four sides of the machine frame and hold the work on the inside of the machine frame by gripping the periphery of the work The robot arm can be opened and closed by being attached to the tip of the arm body, and an arm body configured to be telescopically stretchable in a longitudinal direction by a telescopic structure formed by fitting a plurality of cylinders having different diameters. A clip mechanism, a pivot mechanism that pivots the arm body up and down relative to the machine frame, an opening and closing mechanism that opens and closes the clip, and an expansion and contraction mechanism that expands and contracts the arm body.
In the pressing step, the plurality of robot arms rotate the arm bodies by the rotation mechanism and / or extend / contract by the expansion / contraction mechanism, and the gripping position of the peripheral edge of the workpiece by the clip is changed in the vertical direction. And by appropriately changing in the left-right direction, the load exerted on the workpiece suspended inside the machine frame at the time of press molding is configured to suppress to a desired value,
Each of the rotation mechanism, the telescopic mechanism, and the opening / closing mechanism in the robot arm is driven by a servo motor under numerical control so that the servo motor of each mechanism is not affected by heating during the heating process. The conveying device is characterized in that the servo motor of each mechanism is disposed outside the heating range by being disposed at the base end of the arm body. The transport apparatus according to claim 1, wherein the machine frame is configured to be openable and closable on one side that is a traveling side in the transport direction of the workpiece. The telescopic mechanism in the robot arm transmits the driving force of the servo motor disposed at the base end of the arm main body to the entire arm main body, thereby causing the cylindrical body constituting the arm main body to An extension structure for moving the arm body in the extension direction from the base end side toward the tip end side, and a contraction structure for moving the cylindrical body constituting the arm body in a contraction direction from the tip end side of the arm body toward the base end side; Consists of
As the extension structure, an extension rotator disposed at a base end portion of the arm main body and driven to rotate by the servo motor, and the extension rotator is drawn out from the extension rotator toward the distal end side of the arm main body. When the elongating rotating body rotates, the elongating linear body wound around the elongating rotating body while moving in the contracting direction, and the contracting direction of the elongating linear body during winding onto the elongating rotating body The direction change member which changes the direction of movement to the movement in the extension direction and the force from the extension linear body which moves in the extension direction by the direction change member are transmitted to the cylinder. An extension transmission member that moves in the extension direction,
As the contraction structure, a contraction rotator disposed at a base end portion of the arm main body and driven to rotate by the servo motor, and the contraction rotator is drawn out from the contraction rotator toward the distal end side of the arm main body. The contracting linear body wound around the contracting rotating body while moving in the contracting direction as the contracting rotating body rotates, and the force from the contracting linear body moving in the contracting direction is transmitted to the cylindrical body. The shrinkage | contraction transmission member which moves this cylinder to a shrinkage direction by this, The conveying apparatus of Claim 1 or Claim 2.

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