TRANSFER SYSTEM, TRANSFER METHOD, CONTROL DEVICE, AND COMPUTER PROGRAM

Abstract

To provide a holding device, a transfer system, a holding method, a controller and a computer program in which a plurality of work-pieces are transferred in accordance with a pitch at a transfer destination.SOLUTION: A holding device for a robot comprises: a first holding part which can hold a first work-piece; a second holding part which can hold a second work-piece at a position separated from the first work-piece by a first pitch; and a first pitch variable mechanism which can change the pitch between the first work-piece and the second work-piece from the first pitch to the second pitch. A transfer system includes: the holding device; a multiple joint robot arm to which the holding device is attached; and controller.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a holding device, a transfer system, a holding method, a control device, and a computer program. [Background technology]

[0002] Processing machines such as injection molding machines and die-casting machines can simultaneously process multiple products (hereinafter, finished products, parts, semi-finished products, etc. may be referred to as "workpieces") (hereinafter, changing the shape, structure, material, and other configurations of a workpiece may be referred to as "processing". Also, the equipment or parts used for "processing" may be referred to as "processing machines"). In order to subject multiple workpieces that have been simultaneously processed in this way to a subsequent processing step, to be assembled with other workpieces, to be placed on a pallet or conveyor belt, or to be packed in a box, etc., it is necessary to move the workpieces from their original position to another position (hereinafter, moving the workpieces from their original position to another position may be referred to as "transfer").

[0003] Known methods for transferring a workpiece include using a robot arm to pick up the workpiece and then having a human transfer the workpiece to the desired location, and using a transfer system equipped with a robot arm called a cartoner or palletizer.

[0004] Patent Document 1 describes a workpiece insertion system that holds different kinds of workpieces. This workpiece insertion system includes a first hand unit having a magnetic holding part as a holding part for holding a wire mesh as a workpiece by magnetic force, and a second hand unit having a suction holding part as a holding part for holding a core as a workpiece by suction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-037549 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the product removal pitch when multiple workpieces are removed from a mold, etc. (hereinafter, the distance between adjacent workpieces may be referred to as "pitch" or "distance." In this specification, "pitch" may also be read as "distance.") and the transfer pitch when the removed workpieces are placed at their destination are often different.

[0007] For example, the die pitch when removing multiple workpieces from a die is determined based on the distance between the cavities used to mold the workpieces, and the distance between the cavities is designed based on the convenience of processing and manufacturing such as injection molding. On the other hand, the transfer pitch between the workpieces at the transfer destination may be determined to be smaller than the die pitch, for example, to save space, or may differ in plan or three dimensions depending on the transfer, mounting, and assembly to other components (for example, cases for mounting electronic chips after processing and molding on electronic substrates such as PCBs (Printed Circuit Boards) and hybrid ICs).

[0008] The workpiece input system in Patent Document 1 is a system that enables different types of workpieces to be held according to the robot hand by configuring a robot arm that can rotate around an axis to be switchable between different types of robot hands. For this reason, it is not a transfer system suitable for transferring multiple workpieces.

[0009] Therefore, an object of the present invention is to provide a holding device, a transfer system, a holding method, a control device, and a computer program for transferring multiple workpieces in accordance with the pitch of the transfer destination. [Means for solving the problem]

[0010] The present application discloses a holding device for a robot comprising a first holding portion capable of holding a first workpiece, a second holding portion capable of holding a second workpiece at a position spaced a first pitch from the first workpiece, and a first pitch variable mechanism capable of changing the pitch between the first workpiece and the second workpiece from the first pitch to a second pitch.

[0011] "Pitch" refers to the interval between workpieces, etc. In this specification, "pitch" may be read as "distance."

[0012] The term "workpiece" includes products, parts, semi-finished products, etc. For example, the term "workpiece" includes molded products manufactured by insert molding. The term "workpiece" further includes inserts used in insert molding.

[0013] Various means can be adopted as the means for holding the workpiece depending on the workpiece. For example, the holding portion may be configured to be able to hold the workpiece based on magnetic force from an electromagnet or the like, negative pressure from a vacuum generator or the like, electrostatic force, van der Waals force, etc., or may be configured to be able to hold the workpiece by gripping the workpiece by clamping it.

[0014] A holding unit such as a "first holding unit" includes a robot hand.

[0015] The holding device for a robot may further include a plurality of holding parts. For example, the holding device for a robot may include four or five or more holding parts, each of which may be configured to be capable of holding a workpiece.

[0016] For example, the holding device for this robot may be configured such that the second holding portion is capable of holding the second workpiece at a position spaced the first pitch from the first workpiece in a first direction, and may include a third holding portion capable of holding a third workpiece at a position spaced a third pitch from the first workpiece in a second direction intersecting the first direction, and a fourth holding portion capable of holding a fourth workpiece at a position spaced a fourth pitch from the third workpiece in the first direction.

[0017] This holding device for a robot is capable of holding a first workpiece and a second workpiece arranged to be spaced apart in a first direction, and a third workpiece and a fourth workpiece arranged to be spaced apart in a second direction from the first workpiece.

[0018] The holding device for a robot may include a second pitch variable mechanism capable of changing the pitch between the third workpiece and the fourth workpiece from the fourth pitch to a fifth pitch.

[0019] The holding device for a robot may include a moving means for moving the first holding part in a third direction toward the first workpiece, where the third direction may be defined as a direction perpendicular to the first direction and the second direction.

[0020] Similarly, the holding device for a robot may include a moving means for moving the first holding part or the second holding part in a third direction approaching the first workpiece or the second workpiece.

[0021] Here, the first pitch variable mechanism may include a first rod extending in a first direction from the first holding portion toward the second holding portion and connected to the first holding portion or the second holding portion, and a first pitch change means capable of changing the pitch between the first holding portion and the second holding portion by moving the first rod.

[0022] Moreover, the second pitch variable mechanism may include a second rod extending in the first direction and connected to the third retaining portion or the fourth retaining portion, and a second pitch changing means capable of changing the pitch between the third retaining portion and the fourth retaining portion by moving the second rod.

[0023] Here, the first pitch change means may be, for example, a means for moving the first rod in the first direction, and may be composed of, for example, an air cylinder for moving the first rod with compressed air, or a rack-and-pinion mechanism for moving the first rod by engaging (connecting) a rotating pinion to a rack or integrated with the rack, a linear motor for moving the first rod based on electromagnetic force, etc., an ultrasonic motor for moving the first rod connected to a moving plate or integrated with the moving plate using ultrasonic waves generated by driving a piezoelectric element, etc., an electromagnetic plunger for moving the first rod connected to a plunger or integrated with the plunger, etc.

[0024] Here, the second pitch varying means may be composed of an air cylinder or the like, similar to the first pitch varying means.

[0025] The holding device for the robot may further include a rotating rod connected to each of the first rod and the second rod, and a rotation means capable of rotating the rotating rod about an axial direction in a third direction perpendicular to the first direction and the second direction.

[0026] Such a holding device for a robot may be configured to be capable of aligning the first work, the second work, the third work and the fourth work in a predetermined direction by using the first pitch change means, the second pitch change means and the rotation means while holding the first work, the second work placed at a position spaced from the first work in the first direction by the first holding part, the second holding part, the third holding part and the fourth work placed at a position spaced from the third work in the first direction by the first pitch change means, the second pitch change means and the rotation means, respectively.

[0027] Here, the first work, the second work, the third work, and the fourth work may be aligned in one direction at an equal pitch.

[0028] However, the first work, the second work, the third work, and the fourth work do not have to be aligned at equal pitches. For example, a holding device for a robot may be provided with three or more holding devices on the first rod and three or more holding devices on the second rod, and six or more workpieces may be aligned in a row by a rotating means. In such a case, a different workpiece may be placed between the second work and the third work.

[0029] The present application discloses a workpiece transfer system, the system including the above-described robot holding device and a robot arm attached to the robot holding device.

[0030] The robot arm may be configured to simultaneously transfer the first workpiece held by the first holding portion and the second workpiece held by the second holding portion at a position spaced the second pitch from the first workpiece to a processing machine.

[0031] The transfer system may further include an inspection device for visually inspecting the first workpiece held by the first holding portion of the holding device attached to the robot arm and the second workpiece held by the second holding portion.

[0032] Here, the inspection device may include an imaging device for imaging the workpiece.

[0033] For example, the robot arm may move the first workpiece and the second workpiece so that an imaging device of the inspection device simultaneously images the first workpiece and the second workpiece, with the pitch between the first workpiece and the second workpiece changed to a second pitch smaller than the first pitch by a first pitch variable mechanism of a holding device, and the inspection device may be configured to be able to respectively inspect the first workpiece and the second workpiece based on imaging data including the first workpiece and the second workpiece.

[0034] Furthermore, the robot arm may be configured to move the first workpiece and the second workpiece while the pitch between the first workpiece and the second workpiece is changed to a pitch larger than the second pitch by a first pitch variable mechanism of the holding device.

[0035] The robotic arm may include a flexible drive mechanism. Here, "flexibility" refers to having elasticity, viscosity, or both elasticity and viscosity. Elasticity refers to the property of being deformed when stress is applied and returning to the original shape when the stress is removed, and is sometimes expressed as the term "flexibility" which indicates the ease of elastic deformation. Viscosity refers to the property of generating stress that makes the flow speed of a fluid uniform. A drive mechanism with flexibility may include at least one of, for example, a magnetic fluid, a mechanical spring, an air spring, a magnetic spring, and a vane motor to impart flexibility.

[0036] The "flexible drive mechanism" may be a series elastic actuator. A series elastic actuator includes, for example, a motor and an elastic body such as a spring. Torque output from the motor is transmitted to a rigid link via the elastic body. This makes it easy to bring a member into contact with an object using a robot arm so that the member conforms to the object. It becomes possible to cause the member to conform to the object so that the elastic body included in the series elastic actuator undergoes elastic deformation.

[0037] Note that the term "adjusting a member to conform to an object" refers to moving the member relatively to the object while keeping the member in contact with the object. The relative movement is not limited to translational movement, but also includes rotational movement of the member relative to the object.

[0038] The transfer system may further include a removal device for removing unwanted material adhering to the first workpiece held by the first holding portion of the holding device attached to the robot arm and the second workpiece held by the second holding portion.

[0039] The removal device may be configured to remove unwanted objects such as gates and burrs by spraying dry ice particles, for example. In this case, the removal device may be configured to be able to simultaneously remove unwanted objects from the first workpiece and the second workpiece in a state in which the pitch between the first workpiece and the second workpiece is changed to the second pitch smaller than the first pitch by a first pitch variable mechanism of the holding device.

[0040] The transfer system may include a second robotic arm for holding the removal device, and the second robotic arm may further include a flexible drive mechanism.

[0041] The transfer system may further include a cooling device that cools the first workpiece held by the first holding portion of the holding device attached to the robot arm and the second workpiece held by the second holding portion.

[0042] The removal device may be configured to cool the workpieces by, for example, injecting compressed air. In this case, the cooling device may be configured to simultaneously cool the first workpiece and the second workpiece in a state where the pitch between the first workpiece and the second workpiece is changed to the second pitch smaller than the first pitch by a first pitch variable mechanism of the holding device.

[0043] The transfer system may include a third robot arm for holding the cooling device, and the third robot arm may further include a flexible drive mechanism.

[0044] The robot arm, which is equipped with a flexible driving mechanism, may be configured to move the first work held by the first holding part while contacting a surface of a first area of ​​a destination object, and to move the second work held by the second holding part at a position spaced the second pitch from the first work while contacting a surface of the second area of ​​the destination object.

[0045] Here, the first workpiece or other workpieces may be a FET (Field Emission Transistor) or other semiconductor element, and the object to be transferred may be a PCB (Printed Circuit Board) equipped with multiple sockets into which the leads of the semiconductor element are inserted.

[0046] A robot arm equipped with a flexible drive mechanism may be configured to insert a first workpiece, a first semiconductor element, while abutting multiple leads against a first socket mounted in a first region on a PCB, and to insert a second workpiece, a second semiconductor element, while abutting multiple leads against a second socket mounted in a second region on the PCB.

[0047] The destination object may be a plastic resin having a plurality of compartments. The robot arm having a flexible drive mechanism may be configured to move a first workpiece while contacting a surface of the first compartment to place the first workpiece in the first compartment, and to move a second workpiece while contacting a surface of the second compartment to place the second workpiece in the second compartment.

[0048] The present application discloses a method for holding a workpiece, the method including: holding a first workpiece by a first holding part of a holding device for a robot attached to a robot arm; holding a second workpiece at a position spaced a first pitch from the first workpiece by a second holding part of the holding device for a robot attached to the robot arm; and changing the pitch between the first workpiece and the second workpiece from the first pitch to a second pitch by a first pitch variable mechanism of the holding device for a robot attached to the robot arm.

[0049] The present application discloses a control device. The control device is a control device for a holding device for a robot, the control device including a first holding part capable of holding a first workpiece, a second holding part capable of holding a second workpiece at a position spaced a first pitch from the first workpiece, and a first pitch variable mechanism capable of changing the pitch between the first workpiece and the second workpiece from the first pitch to a second pitch. Specifically, the control device is configured to control the holding device so that the first holding part of the holding device for a robot attached to a robot arm holds the first workpiece, the second holding part of the holding device for a robot attached to the robot arm holds the second workpiece at a position spaced a first pitch from the first workpiece, and the first pitch variable mechanism of the holding device for a robot attached to the robot arm changes the pitch between the first workpiece and the second workpiece from the first pitch to the second pitch.

[0050] The present application discloses a computer program for causing a control device that controls a holding device for a robot to generate a control command, the computer program generating a control command for causing a first holding part of the holding device for a robot attached to a robot arm to hold a first workpiece, causing a second holding part of the holding device for a robot attached to the robot arm to hold a second workpiece at a position spaced a first pitch from the first workpiece, and causing a first pitch variable mechanism of the holding device for a robot attached to the robot arm to change the pitch between the first workpiece and the second workpiece from the first pitch to a second pitch. [Brief description of the drawings]

[0051] [Figure 1] FIG. 1 is a schematic diagram of a robot arm according to an embodiment. [Diagram 2] FIG. 2 is a functional block diagram of a robot system (transfer system) according to one embodiment. [Diagram 3] FIG. 2 is a schematic diagram of a holding device according to one embodiment. [Figure 4] 1 is a flowchart of a transfer method according to an embodiment. [Diagram 5]FIG. 2 is a schematic diagram of a die for molding multiple workpieces in one embodiment. [Figure 6] FIG. 13 is a schematic diagram of a holding device according to a modified example. [Figure 7] FIG. 13 is a schematic diagram of a holding device according to a modified example. [Figure 8] FIG. 13 is a schematic diagram of a holding device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following embodiment is described for the purpose of illustration of the present invention, and is not intended to limit the present invention to the embodiment.

[0053] Fig. 1 is a schematic diagram of a robot arm 20 according to this embodiment, and Fig. 2 is a functional block diagram of a robot system 100 according to this embodiment. As shown in the figure, the robot system 100 includes a robot arm 20 and a control device 10 for controlling the robot arm 20. The robot system 100 according to this embodiment is a transfer system for taking out a plurality of molded products (one example of a workpiece including a "first workpiece" and a "second workpiece") from a transfer source O such as a mold, and transferring them to a transfer destination P such as a pallet or a belt conveyor.

[0054] [Robot arm configuration] As shown in FIG. 1, the robot arm 20 is a vertical articulated robot arm consisting of multiple joints (e.g., seven axes) and includes a base B, a plurality of links L connected to the base B, and a plurality of joints J on which actuators A (FIG. 2) are mounted for rotating the plurality of links L according to their respective rotation axes.

[0055] The actuator A mounted on the joint J is a member for applying a rotational force for rotating the link L along the rotation axis. The actuator A according to this embodiment is configured with a known drive mechanism equipped with a serial elastic actuator, also called an SEA (Serial Elastic Actuator), and for example, an example of an SEA is described in Japanese Patent No. 6329149 and European Patent No. 2890528. The actuator A for rotating the link L is configured with a drive unit AA (FIG. 2) and an elastic body AB (FIG. 2) connected to the drive unit AA. The drive unit AA is configured with, for example, a servo motor, which is an electric motor. The elastic body AB is configured with, for example, a mechanical spring. In the actuator A, the power output from the drive unit AA is transmitted to the link L on the output side via the elastic body AB, causing the link L to rotate.

[0056] Furthermore, the actuator A is equipped with a number of sensors, including a sensor for acquiring the magnitude of the load, a sensor for acquiring the amount of displacement of the elastic body AB, and a sensor for acquiring the amount of displacement of the servo motor and position information of the output shaft. However, the sensor for acquiring the magnitude of the load can be substituted by a sensor calculated from the amount of displacement of the elastic body AB.

[0057] The magnitude of the load can be obtained, for example, from a current sensor that acquires the amount of current flowing through the servo motor that constitutes the drive unit AA, from a sensor that measures the elastic displacement of the elastic body AB, a force sensor that uses a strain gauge, etc., or from the difference in the encoder signals between the actuator input shaft (motor shaft) and output shaft (drive shaft).

[0058] The displacement of the elastic body AB can be obtained from optical sensors provided on both ends of the elastic body AB to obtain the displacement (rotation angle) of both ends of the elastic body A, a magnetic sensor that detects the magnetic field generated from a magnet or the like attached to the elastic body AB, or a strain sensor or the like provided on the elastic body AB. As described above, it is also possible to obtain the torque generated based on the displacement of the elastic body AB and the elastic constant of the elastic body AB.

[0059] As described above, the displacement of the servo motor can be obtained from an optical sensor such as an encoder, an electromagnetic sensor (including electromagnetic induction type and capacitance type), a magnetic sensor such as a Hall element, or a strain sensor.

[0060] The actuator A having the above configuration may be mounted for each joint J corresponding to each link L.

[0061] An equation of motion is established with parameters including the inertia, mass, and length of the part driven by the series elastic actuator, which corresponds to a flexible driving mechanism provided for each of the actuators A, external force, and the elastic modulus of the mechanical spring, which is an elastic body provided in the series elastic actuator. For this reason, the control device 10 is configured to perform mechanical compliance control that controls impedance based on the elastic modulus and displacement amount of the mechanical spring. The series elastic actuator constituting each actuator A may be connected to the drive shaft of a servo motor, which is a driving unit, and may include a gear that transmits power to the elastic body such as the mechanical spring. Furthermore, the series elastic actuator may include a damper mechanism that absorbs impact based on viscosity and a clutch mechanism that switches the transmission of power. When a viscous body such as a viscous damper mechanism is added, or when damping caused by friction between gears is added, an equation of motion is established with a viscosity constant added as a parameter.

[0062] For example, in the case of a series elastic actuator in which a gear is connected to the drive shaft of a servomotor and a load (such as a downstream link) is connected to the output shaft of the gear via an elastic body, the torque generated in the output shaft of the gear is proportional to the current flowing through the servomotor and the gear ratio, and an equation of motion is established in which this torque is equal to the sum of the angular acceleration of the output shaft of the gear multiplied by the inertia, the angular acceleration of the output shaft of the gear multiplied by the viscosity of the gear, and the displacement of the elastic body multiplied by the elastic modulus. By deriving the transfer function of the series elastic actuator based on this equation of motion, mechanical compliance control that controls impedance is possible. It is also possible to measure the transfer function in advance and perform predictive control (feedforward control) for each load capacity.

[0063] With the above-mentioned configuration, it becomes possible to rotate the multiple links L of the robot arm 20, and therefore it becomes possible to freely change the position and posture of the work held by the holding device 30. Note that the information indicating the position in this disclosure may include information indicating the posture if it is reasonably necessary. Furthermore, the robot arm 20 may be equipped with an input / output means including an imaging device for image recognition of the work, etc., and a display for transmitting and receiving information to and from the user. Furthermore, the robot arm 20 may be equipped with a part of the link driven by an actuator having no elasticity.

[0064] [Configuration of holding device]

[0065] As shown in FIG. 1, a holding device 30 for holding an insert member W is detachably attached to a link L or a joint J at the tip of a robot arm 20. The holding device 30 is detachably attached to the link L or the joint J.

[0066] 3 is a schematic diagram showing a holding device 30. As shown in FIGS. 3(A) and 3(B), the holding device 30 includes a first holding portion 32A for holding a first workpiece W1, a second holding portion 32B for holding a second workpiece W2, a pitch variable mechanism 34 for changing the pitch between the first holding portion 32A and the second holding portion 32B, and a housing 36 for supporting the first holding portion 32A and the second holding portion 32B and accommodating the pitch variable mechanism 34. In this specification, the term "pitch" refers to the distance between the holding portions, for example, as shown in FIG. 3. The term "pitch" may be rephrased as "distance."

[0067] The first holding unit 32A holds the first workpiece W1. The means for holding the workpiece can be equipped with a known configuration suitable for the type of workpiece, and may include, for example, a means for generating electromagnetic force, air pressure, van der Waals force, or electrostatic force to hold the workpiece. The first holding unit 32A according to this embodiment includes a robot hand configured to grip the first workpiece W1 by sandwiching it from both sides.

[0068] The second holding portion 32B holds the second workpiece W2. The second holding portion 32B can have a similar configuration to the first holding portion 32A, and therefore a description thereof will be omitted.

[0069] The first holding part 32A and the second holding part 32B are movably supported by a housing 36 connected to a link L or a joint J at the tip. Therefore, by changing the position and posture of the link L with the robot arm, it is possible to change the positions and postures of the first holding part and the second holding part while maintaining the relative positional relationship between the first holding part and the second holding part.

[0070] The pitch variable mechanism 34 changes the pitch between the first holding part 32A and the second holding part 32B. The means for changing the pitch can be equipped with a known configuration suitable for the type of the first holding part 32A, etc. The pitch variable mechanism 34 according to this embodiment is configured to be able to change the pitch by air pressure, and specifically includes a piston rod 34A connected to the second holding part 32B (or the first holding part 32A) and having a piston at its end, an air cylinder 34B connected to the first holding part 32A (or the second holding part 32B) and housing the piston of the piston rod 34A, and a head cover and a rod cover (not shown) provided with ports for supplying and discharging air to and from the space in front of and the space in the rear of the piston in the air cylinder 34B. It is possible to move the piston and the piston rod 34A axially forward (or axially backward) by supplying compressed air to the space in front of (rear of) the piston in the air cylinder using an air supply means (not shown) and discharging the air in the space in the rear (forward) direction. Therefore, it is possible to change the pitch between the second holding portion 32B (or the first holding portion 32A) connected to the piston rod 34A and the first holding portion 32A (or the second holding portion 32B) on which the air cylinder 34B is installed.

[0071] Furthermore, the pitch variable mechanism 34 includes a stopper 34C provided at a predetermined position of the piston rod 34A to restrict the movement of the piston rod 34A and stop it at a predetermined position. When the second holding portion 32B (or the first holding portion 32A) approaches the first holding portion 32A (or the second holding portion 32B) to a predetermined pitch, the stopper 34C provided on the piston rod 34A comes into contact with the air cylinder 34B to restrict the movement of the piston rod 34A, so that the first holding portion 32A and the second holding portion 32B can be prevented from approaching each other at a pitch narrower than the predetermined pitch.

[0072] [Control device configuration] The control device 10 (FIG. 2) controls the robot arm 20 and the holding device. The control device 10 according to this embodiment includes a first control unit 101 for controlling the robot arm 20 and a second control unit 102 for controlling the holding device.

[0073] The first control unit 101 of the control device 10 controls the robot arm 20 based on mechanical compliance control using a series elastic actuator, rather than on the conventional position control.

[0074] The first control unit 101 includes a start position acquisition unit 10A that acquires the start position of a reference position of the robot arm 20 (for example, the center point of a link L corresponding to the hand position, or the center point of the holding device 30. Hereinafter, these are referred to as the "reference position" or "reference portion") and the posture at that time, a target position acquisition unit 10B that acquires a target position and the posture at that time, an allowable range acquisition unit 10C, a path acquisition unit 10D that acquires a path connecting the start position and the target position, a control command acquisition unit 10E that acquires control commands to control servo motors corresponding to the driving units of each actuator A according to the path acquired by the path acquisition unit 10D, and a memory unit 10F.

[0075] The start position acquisition unit 10A acquires, for example, a start position and the posture of the robot arm 20 at that time input from a teaching device (not shown) connectable to the control device 10. The teaching device may be a teaching device that follows online teaching in which the robot arm 20 is actually moved on-site to teach a reference position and posture at that time as the start position, or a teaching device that follows offline teaching such as a text type, simulator type, emulator type, or automatic teaching type in which the position and posture of a reference position are taught as the start position by a computer program.

[0076] The target position acquisition unit 10B acquires, for example, a target position input from a teaching device and a posture at that time, similar to the start position. The target position acquisition unit 10B can acquire a plurality of target positions and postures at that time.

[0077] The allowable range acquisition unit 10C acquires information indicating an allowable range within which the actual reference position of the robot arm 20 can deviate from the path based on the path of the reference position. For example, when the angle of a given link driven by the series elastic actuator when the reference position of the robot arm 20 reaches a certain target position is α, information indicating the allowable range of the link is acquired as, for example, angle information of α±β. β is information in angle units that can be preset as a range of elastic deformation based on the elastic modulus of the elastic body of the series elastic actuator. In order to have flexibility in multiple directions, the robot arm 20 is equipped with multiple series elastic actuators. In this case, the allowable range acquisition unit 10C can acquire information indicating the allowable range for each of multiple links driven by the series elastic actuator.

[0078] The information indicating the allowable range may be position information indicating a predetermined range that a reference position, which is another part of the robot arm 20, can take as a result of a change in the angle of the link. That is, when the angle of a predetermined link is α+β, the tip of the link is displaced by a distance obtained by multiplying β by the length of the link, and accordingly, the downstream part of the robot arm 20 is also displaced. Therefore, the allowable range acquisition unit 10C may acquire position information indicating a predetermined range that the reference position can take by using another part of the robot arm 20 as the reference position. The following description will be centered on the case where the center point of the workpiece held by the link L at the tip is used as the reference position of the robot arm 20. It is preferable that the allowable range is configured to allow the reference position to deviate from the path by at least ±5 mm or more.

[0079] The information indicating the allowable range can be determined in advance as a constant based on the elasticity or viscosity of the drive mechanism in a computer program stored in the storage unit 10F. Therefore, the control device 10 may be configured so that the arithmetic element reads out the computer program to obtain the information indicating the allowable range. Alternatively, the control device 10 may obtain the information indicating the allowable range from a teaching device.

[0080] The path acquisition unit 10D acquires a path (planned trajectory) connecting the start position and the target position by calculation processing or the like.

[0081] The control command acquisition unit 10E acquires, by calculation processing or the like, control commands for controlling each motor mounted on the driving unit AA of each actuator A in order to move the reference position along the path, and supplies the control commands to the robot arm 20. For example, the control command acquisition unit 10E can calculate, by inverse kinematics calculation, the rotation angle of each motor for positioning the reference position on the path, generate a control command based on this, and store the control command in the storage unit 10F.

[0082] The storage unit 10F stores computer programs (including route generation algorithms) for executing the processes shown in each embodiment, as well as necessary data and other information.

[0083] The second control unit 102 controls the holding device 30. Specifically, the second control unit 102 is configured to be able to control the first holding unit and the second holding unit to grip the first workpiece W1 and the second workpiece W2 based on a command from the first control unit 101, and is also configured to be able to control the pitch variable mechanism to change the pitch between the first workpiece W1 and the second workpiece W2 based on a command from the first control unit 101.

[0084] Regarding the hardware configuration of the control device 10 described above, the control device 10 can be configured from a computer including, for example, a processor such as a central processing unit (CPU) or a graphical processing unit (GPU), a volatile storage element such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), a non-volatile storage element such as a NOR flash memory, a NAND flash memory, or a hard disk drive (HDD), and a communication means such as a bus connecting these elements. The non-volatile storage element is a storage medium that stores information non-transitory. The volatile storage element temporarily stores at least a part of these computer programs and the results of the arithmetic processing. The storage unit 10F is configured from these storage elements. In addition, the storage unit 10F functions as a start position acquisition unit 10A, a target position acquisition unit 10B, an allowable range acquisition unit 10C, a path acquisition unit 10D, a control command acquisition unit 10E, and a second control unit 102 by the computation element executing the computer program stored in the storage unit 10F. However, at least some of these arithmetic elements, non-volatile storage elements, etc. may be installed in a remote location connected to a communication network such as the Internet. For example, the arithmetic elements may be configured to acquire a computer program or necessary data via a communication network. The control device 10 may also include two or more processors as arithmetic elements, the first control unit 101 being configured from a first processor, and the second control unit 102 being configured from a second processor. Furthermore, the control device 10 may be configured to be able to execute a plurality of computer programs, and the control by the first control unit 101 may be realized based on the first computer program, and the control by the second control unit 102 may be realized based on the second computer program. The first computer program may be stored in a non-volatile storage element of the storage unit 10F. The second computer program may be stored in a non-volatile storage element of the storage unit 10F that is different from the non-volatile storage element that stores the first computer program.

[0085] The control device 10 and the robot arm 20 are configured to be able to transmit and receive information via wireless or wired communication means.

[0086] A teaching device for teaching the robot system 100 to perform an operation may be connected to or integrated with the control device 10. The teaching device may be provided on the robot arm 20, and for example, an input / output means including a display may be used as a part of the teaching device. The teaching device may include, for example, a portable teaching pendant. The teaching device includes a computing element, a volatile storage element, and a non-volatile storage element, similar to the control device 10, and further includes a display means having a display and an input means having a plurality of operation keys and a lever. The input means may be configured as a touch panel type input means that inputs are made by pressing the display.

[0087] The robot system 100 may additionally include at least one of an appearance inspection device 110, a removal device 120, and a cooling device 130.

[0088] [Visual inspection equipment] The appearance inspection device 110 includes an imaging unit configured to simultaneously image the appearance of a first workpiece W1 held by a first holding portion 32A of the holding device 30 and a second workpiece W2 held by a second holding portion 32B, and an inspection unit configured to inspect the appearance of the first workpiece W1 and the second workpiece W2 based on the imaging data acquired by the imaging unit.

[0089] In this embodiment, the first work W1 and the second work W2 are molded products (more specifically, insert molded products), so the appearance inspection device 110 simultaneously images the first work W1 and the second work W2, which are two molded products held by a holding device 30 attached to the robot arm 20, and performs an appearance inspection for defects such as scratches or burrs that exceed a standard value.

[0090] The robot arm 20 moves both the first work W1 and the second work W2 to a position where they can be suitably imaged by the imaging unit, taking into consideration the viewing angle and focal length of the imaging unit. In addition, the pitch variable mechanism 34 of the holding device 30 changes the pitch between the first work W1 and the second work W2 from pitch P1 to pitch P3. Here, pitch P3 is smaller than pitch P1. In this manner, with the pitch between the first work W1 and the second work W2 set to pitch P3, the imaging unit is configured to simultaneously image both the first work W1 and the second work W2.

[0091] [Removal device] The removal device 120 includes a robot arm and a tool attached to the robot arm for removing unwanted material adhering to the surfaces of the first workpiece W1 held by the first holding portion 32A of the holding device 30 and the second workpiece W2 held by the second holding portion 32B.

[0092] In this embodiment, the first workpiece W1 and the second workpiece W2 are molded products (more specifically, insert molded products). The removal device 120 uses a tool to remove unnecessary objects such as burrs attached to the first workpiece W1 and the second workpiece W2, which are two molded products held by the holding device 30.

[0093] Here, the robot arm of the removal device 120 may have the same configuration as the robot arm 20 and the control device 10 of the robot system 100. In that case, the robot arm has a flexible drive mechanism, so that it is possible to make the tool follow the first workpiece W1 (and the second workpiece W2), that is, to move the tool relatively to the first workpiece W1 (and the second workpiece W2) while making contact with the first workpiece W1. With such a configuration, it is possible to prevent the first workpiece W1 (and the second workpiece W2) from being damaged when the tool comes into contact with the first workpiece W1 (and the second workpiece W2). Note that when the robot arm of the removal device 120 has a flexible drive mechanism, the robot arm 20 may be configured to hold the first workpiece W1 and the second workpiece W2 in an operation mode that does not exhibit flexibility.

[0094] The tool attached to the robot arm may be, for example, a nozzle for spraying dry ice powder. In this case, since the robot arm is provided with a flexible driving mechanism, it is possible to prevent the workpiece from being damaged when the nozzle of the cooling device 130 comes into contact with the workpiece. Since the nozzle is configured to be able to spray solid dry ice powder (fine particles), it is possible to cool the first workpiece W1 and the second workpiece W2 using the heat of vaporization in an inert atmosphere with a low oxygen concentration, and also possible to remove unnecessary materials adhering to the surfaces of the first workpiece W1 and the second workpiece W2.

[0095] In the removing step, the pitch variable mechanism 34 of the holding device 30 may change the pitch between the first workpiece W1 and the second workpiece W2 from pitch P1 to pitch P4, which is larger than pitch P1. With the pitch between the first workpiece W1 and the second workpiece W2 set to pitch P4 in this manner, the removing device 120 removes unwanted material adhering to the surface of the first workpiece W1 (or the second workpiece W2), thereby reducing the possibility that the unwanted material cannot be removed successfully due to the second workpiece W2 (or the first workpiece W1) getting in the way, or that the tool will interfere with the second workpiece W2 (or the first workpiece W1).

[0096] Conversely, in the removal process, the pitch variable mechanism 34 of the holding device 30 may change the pitch between the first workpiece W1 and the second workpiece W2 from pitch P1 to pitch P5, which is lower than pitch P1. In this manner, with the pitch between the first workpiece W1 and the second workpiece W2 set to pitch P5, the removal device 120 sprays dry ice powder onto the surfaces of the first workpiece W1 and the second workpiece W2, thereby making it possible to efficiently cool both the first workpiece W1 and the second workpiece W2.

[0097] As described above, by carrying out the removal process while changing the pitch using the pitch variable mechanism 34, it is possible to remove the unnecessary materials efficiently.

[0098] Instead of the above configuration, the robot arm of the removal device 120 may be configured as a normal robot arm that does not have flexibility. Even with such a configuration, the robot arm 20 can hold the first workpiece W1 and the second workpiece W2 in an operation mode that exhibits flexibility, thereby making it possible to prevent the first workpiece W1 (and the second workpiece W2) from being damaged.

[0099] [Cooling device] The cooling device 130 includes a robot arm, a nozzle attached to the robot arm for spraying compressed air, and a temperature sensor for detecting the temperature of the workpiece. The robot arm may have the same configuration as the robot arm 20 and the control device 10 of the robot system 100. In this case, the robot arm includes a flexible drive mechanism, so that it is possible to prevent the workpiece from being damaged when the nozzle of the cooling device 130 comes into contact with the workpiece. The nozzle is configured to be able to spray compressed air, so that it is possible to cool the first workpiece W1 and the second workpiece W2 and to remove unnecessary materials adhering to the surfaces of the first workpiece W1 and the second workpiece W2.

[0100] Similarly to the above, the pitch variable mechanism 34 of the holding device 30 may change the pitch between the first workpiece W1 and the second workpiece W2 from pitch P1 to pitch P5 which is smaller than pitch P1. In this manner, with the pitch between the first workpiece W1 and the second workpiece W2 set to pitch P5 (including the case where they are in contact), the cooling device 130 can efficiently cool both the first workpiece W1 and the second workpiece W2 by injecting compressed air onto the surfaces of the first workpiece W1 and the second workpiece W2.

[0101] [Workpiece transfer method] The workpiece transfer method according to this embodiment will be described below. As described above, the workpieces in this embodiment are semi-finished insert molded products. The transfer system takes out multiple workpieces that are insert molded products, changes the pitch, and places the workpieces on a pallet as a transfer destination.

[0102] FIG. 4 is a flow chart showing a method for transferring a workpiece according to this embodiment. FIG. 5 is a schematic diagram of a mold M (an example of a source and also an example of a "processing machine"), which is a lower mold of a vertical injection molding machine used in this embodiment. As shown in the figure, the mold M has a plurality of cavities, so that a plurality of molded products including a first workpiece W1 and a second workpiece W2 are molded simultaneously. Here, the pitch between the first workpiece W1 and the second workpiece W2 is a first pitch P1. If the first pitch P1 is made smaller, the number of pieces obtained increases, but the variation in the quality of the molded products, such as dimensions, weight, and appearance, increases. Therefore, when the workpiece is, for example, a precision part or an electronic part, the first pitch P1 is often set relatively large.

[0103] Once molding using die M is completed, removal of the workpiece begins.

[0104] First, the second control unit 102 controls the pitch variable mechanism 34 so that the center-to-center distance PC1 between the first workpiece W1 and the second workpiece W2, which are spaced apart by the first pitch, matches the center-to-center distance between the first holding portion 32A and the second holding portion 32B (step S41).

[0105] On the other hand, the first control unit 101 controls the robot arm 20 to drive the link L so that the first holding unit 32A is positioned above the first workpiece W1 and the second holding unit 32B is positioned above the second workpiece W2 (step S42), as shown in Fig. 3(A). Note that steps S41 and S42 may be performed simultaneously, or the order of steps S41 and S42 may be reversed (step S42 may be performed first).

[0106] Next, in a state in which the second control unit 102 opens the robot hands of the first holding unit 32A and the second holding unit 32B, the first control unit 101 moves the first holding unit 32A and the second holding unit 32B downward in the plane of the drawing to approach the first workpiece W1 and the second workpiece W2, respectively. After that, the second control unit 102 closes the robot hands of the first holding unit 32A and the second holding unit 32B to grip (hold) the first workpiece W1 and the second workpiece W2, respectively (step S43). Here, the robot hands of the first holding unit 32A and the second holding unit 32B may be closed simultaneously to grip the first workpiece W1 and the second workpiece W2 simultaneously. When held by the first holding unit 32A and the second holding unit 32B, the pitch between the first workpiece W1 and the second workpiece W2 is the first pitch P1.

[0107] Next, a visual inspection step, a removal step of deposits, and a cooling step are performed on the workpiece, although all or some of these steps may not be performed.

[0108] When the appearance inspection process is performed, the first control unit 101 controls the robot arm 20 to move both the first work W1 and the second work W2 to a position where they can be suitably imaged by the imaging unit of the appearance inspection device 110. Next, the second control unit 102 may control the pitch variable mechanism 34 to change the pitch between the first work W1 and the second work W2 from pitch P1 to pitch P3, which is smaller than pitch P1. By changing the pitch to a smaller pitch in this manner, the imaging unit can simultaneously image both the first work W1 and the second work W2. Next, the imaging unit images the first work W1 and the second work W2, and the inspection unit inspects the appearance of the first work W1 and the second work W2 based on the imaging data acquired by the imaging unit, thereby performing the appearance inspection process (step S44).

[0109] When the process of removing the adhering matter is performed, the first control unit 101 controls the robot arm 20 to move the first workpiece W1 and the second workpiece W2 to a position where the workpiece can be removed by the removing device 120. Next, the second control unit 102 may control the pitch variable mechanism 34 to change the pitch between the first workpiece W1 and the second workpiece W2 from the pitch P1 to a pitch P4 larger than the pitch P1. By changing the pitch to a larger pitch in this way, it becomes possible to remove the adhering matter without one of the workpieces getting in the way. Next, the removing device 120 removes unnecessary matters such as burrs attached to the surface of the first workpiece W1 by bringing a nozzle, which is an example of a tool, close to the first workpiece W1 or by following the nozzle while spraying dry ice powder, and then by following the nozzle against the second workpiece W2 to remove unnecessary matters attached to the surface of the second workpiece W2, thereby performing the process of removing the adhering matter (step S45).

[0110] After molding, the workpieces are at high temperature, so a cooling process may be performed. When the cooling process is performed, the first control unit 101 controls the robot arm 20 to move the first workpiece W1 and the second workpiece W2 to a position where they can be cooled by the cooling device 130. Next, the second control unit 102 may control the pitch variable mechanism 34 to change the pitch between the first workpiece W1 and the second workpiece W2 from the pitch P1 to a pitch P5 smaller than the pitch P1. By changing the pitch to a smaller pitch and bringing the two workpieces closer together in this way, efficient cooling is possible. Note that the pitch P3 and the pitch P5 may be the same. Next, the cooling device 130 brings the nozzle closer to the first workpiece W1 and the second workpiece W2, injects compressed air, and cools both the first workpiece W1 and the second workpiece W2, thereby performing the cooling process (step S46). In addition, since the nozzle is attached to the robot arm equipped with a flexible driving mechanism, it is possible to suppress damage to the workpieces when the nozzle comes into contact with the workpieces. The appearance inspection step (step S44) may be performed after the deposit removing step (step S45) or the cooling step (step S46).

[0111] Next, the first work W1 and the second work W2 are transferred to the transfer destination P. In this embodiment, the first work W1 and the second work W2 are transferred to a pallet. Here, in order to save space, the second pitch P2 corresponding to the pitch between the first work W1 and the second work W2 at the transfer destination P is smaller than the pitch P1 corresponding to the pitch between the first work W1 and the second work W2 on the mold designed based on manufacturing convenience. In addition, if the pallet that is the transfer destination P is made of a soft material such as plastic, the pallet may be dented or damaged when the work comes into contact with the surface of the pallet. For this reason, so-called palletizing has been performed manually by humans or by transferring the work one by one using a robot arm. In response to this, the inventors of the present application have conceived a transfer system that enables multiple workpieces to be transferred according to the pitch of the transfer destination P.

[0112] First, the second control unit 102 controls the pitch variable mechanism 34 so that the pitch between the first work W1 and the second work W2, which have been separated by the first pitch P1, becomes the second pitch P2 (step S47). Here, the second pitch P2 corresponds to the pitch between the first work W1 and the second work W2 on the pallet, which is the transfer destination P. In this embodiment shown in Fig. 3(B), the pallet is provided with the first recess DT1 and the second recess DT2 for inserting and arranging the works, so the second pitch P2 corresponds to the pitch between adjacent recesses.

[0113] Specifically, the second control unit 102 supplies compressed air to the space in front or behind the piston in the air cylinder 34B and exhausts the air in the space in front or behind the piston, thereby moving the piston and the piston rod in the axial direction. Since the second holding unit 32B is connected to the piston rod 34A, it is possible to move the second holding unit 32B and the second workpiece W2 held therein in a direction approaching the first holding unit 32A and the first workpiece W1. Here, since a stopper 34C is provided on the outer periphery of the piston rod 34A at a predetermined position, the stopper 34C can contact the air cylinder 34B to adjust the pitch between the first workpiece W1 and the second workpiece W2. More specifically, when the pitch between the first workpiece W1 and the second workpiece W2 becomes the second pitch P2, the stopper 34C is provided in advance at a position where it contacts the air cylinder 34B, so that the pitch between the first workpiece W1 and the second workpiece W2 can be changed to the second pitch P2. However, it is also possible to change the pitch between the two workpieces in other ways.

[0114] Meanwhile, the first control unit 101 controls the robot arm 20 to drive the link L so that the first holding unit 32A is positioned above the first workpiece W1 and the second holding unit 32B is positioned above the second workpiece W2 (step S48). Note that steps S47 and S48 may be performed simultaneously, or the order of steps S47 and S48 may be reversed (step S48 may be performed first).

[0115] Next, with the second control unit 102 closing each of the robot hands of the first holding unit 32A and the second holding unit 32B, the first control unit 101 moves the first holding unit 32A and the second holding unit 32B downward in the plane of the paper, thereby bringing the first workpiece W1 closer to the first recess DT1 and the second workpiece W2 closer to the second recess DT2.

[0116] The first control unit 101 continues to move the first holding unit 32A and the second holding unit 32B downward in the drawing, so that the first work W1 comes into contact with the wall surface of the first recess DT1, and the second work W2 comes into contact with the wall surface of the second recess DT2, and the first work W1 moves while conforming to the wall surface of the first recess DT1, and the second work W2 moves while conforming to the wall surface of the second recess DT2. Since the robot arm 20 has a flexible driving mechanism, it is possible to insert the first work W1 and the second work W2 into the first recess DT1 and the second recess DT2 without any gaps while exerting an elastic force in a direction toward the wall surface so that the first work W1 and the second work W2 press the wall surface of the first recess DT1 and the wall surface of the second recess DT2, respectively. The allowable range acquisition unit 10C may be configured to acquire an allowable range determined based on an elastic region range in which the pallet in contact with the work does not undergo plastic deformation. By configuring in this way, it is possible to suppress plastic deformation of the pallet due to contact with the work.

[0117] When the first control unit 101 has completed inserting the first work W1 and the second work W2 into the first recess DT1 and the second recess DT2, the second control unit 102 releases the first work W1 and the second work W2 by opening the robot hands (S49, FIG. 3(B)). When the holding by the first holding unit 32A and the second holding unit 32B is released, the pitch between the first work W1 and the second work W2 is the second pitch P2.

[0118] As described above, according to this embodiment, it is possible to provide a transfer system that enables multiple workpieces to be transferred in accordance with the pitch at the transfer destination P.

[0119] [First Modification] A first modified example of the first embodiment will be described below. In the first embodiment, the holding device holds two workpieces, but the present invention is not limited to this. Fig. 6 shows a schematic diagram of a holding device 50 according to the modified example. The holding device 50 includes a first holding part 52A capable of holding a first workpiece W1, a second holding part 52B capable of holding a second workpiece W2 at a position spaced a first pitch P1 from the first workpiece W1, a first pitch variable mechanism 54A capable of changing the pitch between the first workpiece W1 and the second workpiece W2 from the first pitch P1 (FIG. 6(A)) to a second pitch P2 (FIG. 6(B)), a third holding part 52C capable of holding a third workpiece W3, a fourth holding part 52D capable of holding a fourth workpiece W4 at a position spaced a fourth pitch P4 from the third workpiece W3, and a second pitch variable mechanism 54B capable of changing the pitch between the third workpiece W3 and the fourth workpiece W4 from the fourth pitch P4 (FIG. 6(A)) to a fifth pitch P5 (FIG. 6(B)). When the direction from the first workpiece W1 to the second workpiece W2 is defined as the first direction D1, and the direction from the first workpiece W1 to the third workpiece W3 is defined as the second direction D2, the second holding portion 52B is configured to be able to hold the second workpiece W2 at a position spaced apart from the first workpiece W1 by a first pitch P1 in the first direction D1. When the pitch between the first workpiece W1 and the third workpiece W3 in the second direction D2 intersecting with the first direction D1 is defined as a third pitch P3, the third holding portion 52C is configured to be able to hold the third workpiece W3 at a position spaced apart from the first workpiece W1 by a third pitch P3 in the second direction D2. When the pitch between the third workpiece W3 and the fourth workpiece W4 in the first direction D1 is defined as a fourth pitch P4, the fourth holding portion 52D is configured to be able to hold the fourth workpiece W4 at a position spaced apart from the third workpiece W3 by a fourth pitch P4 in the first direction D1. However, the first pitch P1 and the fourth pitch P4 may be the same.

[0120] The first pitch variable mechanism includes a first piston rod extending in the first direction D1 and connected to the second holding portion 52B, and an air cylinder (an example of a "first pitch changing means") that can change the pitch between the first holding portion 52A and the second holding portion 52B by moving the first piston rod to move the second holding portion 52B closer to or away from the first holding portion 52A (and therefore change the pitch between the first workpiece W1 and the second workpiece W2).

[0121] The second pitch variable mechanism includes a second piston rod extending in the first direction D1 and connected to the fourth holding portion 52D, and an air cylinder (an example of a "second pitch changing means") that can change the pitch between the third holding portion 52C and the fourth holding portion 52D by moving the second piston rod to move the fourth holding portion 52D closer to or away from the third holding portion 52C (thus changing the pitch between the third workpiece W3 and the third workpiece W4).

[0122] As shown in the figure, by further arranging a third piston rod of a third pitch variable mechanism 54C in the second direction D2 connecting the first holding portion 52A and the third holding portion 52C, the pitch may be further changed in the second direction D2 as well (for example, changeable from pitch P3 to pitch P6) as shown in Fig. 6(C). On the other hand, by not providing such a piston rod unlike the figure, the pitch between the first holding portion 52A and the second holding portion 52B and the pitch between the third holding portion 52C and the fourth holding portion 52D may be changed independently in the first direction D1.

[0123] Each holding section in the figure is equipped with a means for holding the workpiece by generating negative pressure to suck the workpiece in. With this configuration, it is no longer necessary to hold the side of the workpiece, making it possible to achieve a narrower pitch between the workpieces (including the case where the workpieces are in contact with each other).

[0124] [Second modified example] A second modified example of the first embodiment will be described below. In the first embodiment and the first modified example, the variable direction of the pitch was limited to the horizontal direction. However, the holding device may further include a moving means for moving the workpiece in a direction approaching the workpiece (an example of the "third direction") and in a direction away from the workpiece. FIG. 7 shows a schematic diagram of a holding device 60 according to the second modified example. This holding device 60 includes a first holding part 62A capable of holding the first workpiece W1, a second holding part 62B capable of holding the second workpiece W2 at a position spaced apart from the first workpiece W1 by a first pitch P1, a first pitch variable mechanism 64 capable of changing the pitch between the first workpiece W1 and the second workpiece W2 from the first pitch P1 to a second pitch P2, and a moving means 66 for moving the second holding part 62B in a direction approaching the second workpiece W2 and in a direction away from the second workpiece W2.

[0125] Here, the second holding portion 62B may include an upper portion 62B1 connected to the first piston rod 64A of the first pitch variable mechanism 64, and a lower portion 62B2 connected to the robot hand of the second holding portion 62B.

[0126] The moving means 66 may also include a second piston rod 66A connected to the lower part 62B2, and an air cylinder 66B provided in the upper part 62B1 for moving the second piston rod 66A.

[0127] With this configuration, by operating the air cylinder 64B of the first pitch variable mechanism 64, the first piston rod 64A is moved in the axial direction (first direction D1), thereby moving the second holding portion 62B and the second workpiece W2 held therein in the first direction D1, and by operating the air cylinder 66B of the moving means 66, the second piston rod 66A is moved in the axial direction (third direction D3), thereby moving the second holding portion 62B and the second workpiece W2 held therein in the third direction D3.

[0128] Therefore, even when the workpieces are placed on a serving table PT (an example of a transfer destination) having a step in the third direction D3 as shown in the same figure, it is possible to place the first workpiece W1 and the second workpiece W2 at different heights.

[0129] Even when two workpieces are placed at the same height as shown in Fig. 3(B), the first workpiece W1 may be inserted into the first recess DT1 while contacting the wall of the first recess DT1 using the moving means, and then the second workpiece W2 may be inserted into the second recess DT2 while contacting the wall of the second recess DT2. This configuration allows the workpieces to be placed in order, making it possible to more reliably place each workpiece. It also makes it possible to place each workpiece at the destination while reliably following the wall of the destination.

[0130] Furthermore, even if the first workpiece and the second workpiece have different configurations (including shapes) and therefore need to be held (including gripped) at different heights, by providing the holding device with a configuration equivalent to the moving means 66, it is possible for the first holding section and the second holding section to hold the first workpiece W1 and the second workpiece W2 at different heights, respectively, and to release the holding.

[0131] As shown in the figure, a stopper 66C may also be provided on the second piston rod 66A in order to restrict movement of the second holding portion 62B relative to the first holding portion 62A in the third direction D3.

[0132] [Third Modification] A third modified example of the first embodiment will be described below. In the first embodiment, the first modified example, and the second modified example, the variable direction of the pitch was limited to the translation direction. However, the holding device may further include a rotation means for rotating the workpiece. Figures 8(A) and (B) show schematic diagrams of a holding device 70 according to the third modified example. Note that the holding parts and the like are omitted in the figures in order to easily express the changes in the movement of each workpiece. This holding device 70 has four holding parts (not shown) and, as shown in Figure 8 (A), a first pitch variable mechanism including a first piston rod 74A extending in a first direction D1 from the first holding part toward the second holding part and an air cylinder (not shown) capable of changing the pitch between the first holding part and the second holding part by moving the first piston rod 74A axially, and a second pitch variable mechanism including a second piston rod 74B extending in the first direction D1 from the third holding part toward the fourth holding part and an air cylinder (not shown) capable of changing the pitch between the third holding part and the fourth holding part by moving the second piston rod 74B axially. The holding device 70 further includes a rotating rod 76A connecting the first piston rod 74A and the second piston rod 74B, and a rotating means 76 capable of rotating the rotating rod 76A about an axial direction that is a first direction D1 (left-right direction on the paper) and a third direction D3 (vertical direction on the paper) perpendicular to a second direction D2 (up-down direction on the paper) from the first holding part toward the third holding part. The rotating means 76 may include, for example, a crank mechanism. When the rotation axis of the rotating rod 76A is set to one end on the first piston rod 74A (or the second piston rod 74B), the crank mechanism may include a slider that slides on the first piston rod 74A (second piston rod 74B) and a link that connects the slider to the other end of the rotating rod 76A. The slider can be translated parallel to the second piston rod 74B using air to rotate the rotating rod 76A about one end of the rotating rod 76A as a fulcrum.

[0133] Although it is possible to use other known rotating means such as a motor as the rotating means, the crank mechanism has higher operational stability than a drive system that uses a stepping motor, which may experience loss of synchronism, or a magnetic reducer as a motor reducer.

[0134] With the holding device 70 as described above, it is possible to align the first work W1, the second work W2 placed at a position spaced a first pitch P1 from the first work W1 in the first direction D1, the third work W3 placed at a position spaced a third pitch P3 from the first work W1 in the second direction D2, and the fourth work W4 placed at a position spaced a first pitch P1 from the third work W3 in the first direction D1 in a row by rotating the rotating rod 76A (Figure 8(B)).

[0135] In this case, by adjusting the pitch between the first work W1 and the second work W2 using the first pitch changing means and adjusting the pitch between the third work W3 and the fourth work W4 using the second pitch changing means, it is possible to align the first work W1, the second work W2, the third work W3 and the fourth work W4 at equal intervals at a second pitch P2 which is smaller than the first pitch P1.

[0136] [Modified workpiece] In the above embodiment and each modified example, the workpiece is a molded product formed by insert molding. However, the present invention can be applied to workpieces other than molded products.

[0137] For example, the workpiece may be an insert used in insert molding. In this case, the holding device can be configured so that the first insert is held as the first workpiece by the first holding part of the holding device, the second insert is held as the second workpiece by the second holding part, and then the first insert is transferred to the first cavity of a mold and the second insert is transferred to the second cavity of the same mold (an example of a processing machine). Here, the removal pitch when holding the first insert and the second insert may be smaller than the transfer pitch when transferring them to the mold.

[0138] The workpiece may be a FET (Field Emission Transistor), a power semiconductor, or other semiconductor element. In this case, the object to be transferred may be a PCB (Print Circuit Board) on which a plurality of sockets into which the leads of the semiconductor element are inserted are mounted. In addition, if the busbar unit is an automobile part in which the busbar used in an electric vehicle is injection molded with PBT (polybutyl terephthalate), it can be directly attached to the battery unit, the vehicle body, or a sub-assembly member of the vehicle body. Furthermore, in the case where the SSR (Solid State Relay) used in household electrical appliances and measuring instruments is injection molded with epoxy resin, etc. and sealed and insulated, it can be directly set in the housing, etc.

[0139] The robot arm equipped with a flexible drive mechanism may be configured to insert a plurality of leads of a first semiconductor element, which is a first workpiece, while abutting the leads against a first socket mounted in a first region on the PCB, and to insert a plurality of leads of a second semiconductor element, which is a second workpiece, while abutting the leads against a second socket mounted in a second region on the PCB. By using the flexible drive mechanism to transfer the semiconductor element, which is the workpiece, onto the PCB substrate, which is the transfer destination, it is possible to prevent the leads from being bent due to being poorly inserted into the socket.

[0140] In addition, the present invention can be modified in various ways without departing from the spirit of the present invention. For example, some components in one embodiment can be added to other embodiments within the scope of ordinary creativity of a person skilled in the art. Also, some components in one embodiment can be replaced with corresponding components in other embodiments. [Explanation of symbols]

[0141] 10 Control device 10A Start position acquisition part 10B Target position acquisition section 10C Tolerance range acquisition section 10D Route acquisition section 10E Control command acquisition unit 10F storage section 20 Robot Arm 30 Holding device 32A Holding part 32B Holding part 34 Variable pitch mechanism 34A Piston rod 34B Air Cylinder 34C Stopper 36 Housing 50 Holding device 54A Variable pitch mechanism 54B variable pitch mechanism 54C variable pitch mechanism 60 Holding device 64 Variable pitch mechanism 64A Piston rod 64B Air Cylinder 66 Transportation 66A Piston rod 66B Air Cylinder 66C Stopper 70 Holding device 74A Piston rod 74B Piston rod 76 Rotation Means 76A Rotating Rod 100 Robot System 101 First control section 102 Second control section 110 Visual inspection equipment 120 Removal device 130 Cooling device

Claims

1. A holding device for the robot; a robot arm attached to a holding device for the robot; Equipped with The holding device comprises: A first holding unit capable of holding a first workpiece; A second holding portion capable of holding a second workpiece at a position spaced a first pitch from the first workpiece; a first pitch variable mechanism capable of changing the pitch between the first workpiece and the second workpiece from the first pitch to a second pitch; Equipped with the robot arm includes a flexible drive mechanism; The transfer system is configured such that the robot arm moves the first workpiece held by the first holding unit while contacting the surface of the first area of ​​the target object to be transferred, and moves the second workpiece held by the second holding unit at a position spaced the second pitch from the first workpiece while contacting the surface of the second area of ​​the target object to be transferred.

2. The second holding portion is configured to be able to hold the second workpiece at a position spaced apart from the first workpiece in a first direction by the first pitch, a third holding portion capable of holding a third workpiece at a position spaced a third pitch from the first workpiece in a second direction intersecting the first direction; a fourth holding portion capable of holding a fourth workpiece at a position spaced a fourth pitch from the third workpiece in the first direction; a second pitch variable mechanism capable of changing the pitch between the third workpiece and the fourth workpiece from the fourth pitch to a fifth pitch; The transfer system according to claim 1 , further comprising:

3. the first pitch variable mechanism includes a first rod extending in a first direction from the first holding portion toward the second holding portion and connected to the first holding portion or the second holding portion, and a first pitch change means capable of changing the pitch between the first holding portion and the second holding portion by moving the first rod; The transfer system described in claim 2, wherein the second pitch variable mechanism comprises a second rod extending in the first direction and connected to the third holding part or the fourth holding part, and a second pitch change means capable of changing the pitch between the third holding part and the fourth holding part by moving the second rod.

4. a rotating rod connected to the first rod and the second rod, The transfer system according to claim 3 , further comprising a rotating means capable of rotating the rotating rod about an axial direction in a third direction perpendicular to the first direction and the second direction.

5. The transfer system of claim 4 is configured to be capable of aligning the first work, the second work, the third work and the fourth work in a predetermined direction by using the first pitch change means, the second pitch change means and the rotation means while holding the first work, the second work placed at a position spaced from the first work in the first direction by the first holding part, the second holding part, the third holding part and the fourth holding part, respectively.

6. The transfer system according to any one of claims 1 to 5, wherein the robot arm is configured to simultaneously transfer the first workpiece held by the first holding portion and the second workpiece held by the second holding portion at a position spaced apart from the first workpiece by the second pitch to a processing machine.

7. The transfer system according to any one of claims 1 to 6, further comprising an inspection device for visually inspecting the first workpiece held by the first holding portion of the holding device attached to the robot arm and the second workpiece held by the second holding portion.

8. The transfer system according to any one of claims 1 to 7, further comprising a removal device for removing unwanted material adhering to the first workpiece held by the first holding portion of the holding device attached to the robot arm and the second workpiece held by the second holding portion.

9. The transfer system according to any one of claims 1 to 8, further comprising a cooling device that cools the first workpiece held by the first holding portion of the holding device attached to the robot arm and the second workpiece held by the second holding portion.

10. A first workpiece is held by a first holding part of a holding device for a robot attached to a robot arm having a flexible drive mechanism; a second holding portion of the holding device for the robot attached to the robot arm is spaced a first pitch from the first holding portion, and the second holding portion holds a second workpiece at a position spaced a first pitch from the first workpiece; changing a pitch between the first workpiece and the second workpiece from the first pitch to a second pitch by a first pitch variable mechanism of a holding device for the robot attached to the robot arm; The robot arm moves the first workpiece held by the first holding unit while contacting a surface of a first region of a destination object, and moves the second workpiece held by the second holding unit at a position spaced apart by the second pitch from the first workpiece while contacting a surface of a second region of the destination object. Transfer method.

11. A control device for controlling a holding device for a robot, the holding device including a first holding portion capable of holding a first workpiece, a second holding portion capable of holding a second workpiece at a position spaced a first pitch from the first workpiece, and a first pitch variable mechanism capable of changing the pitch between the first workpiece and the second workpiece from the first pitch to a second pitch, and a robot arm including a flexible drive mechanism, a first workpiece is held by a first holding portion of a holding device for a robot attached to the robot arm; a second holding portion of the holding device for the robot attached to the robot arm is spaced a first pitch from the first holding portion, and the second holding portion holds the second workpiece at a position spaced a first pitch from the first workpiece; changing a pitch between the first workpiece and the second workpiece from the first pitch to the second pitch by a first pitch variable mechanism of a holding device for the robot attached to the robot arm; A control device that controls the holding device and the robot arm so that the robot arm moves the first work held by the first holding unit while contacting the surface of the first area of ​​the target object to be transferred, and moves the second work held by the second holding unit at a position spaced the second pitch from the first work while contacting the surface of the second area of ​​the target object to be transferred.

12. A computer program for generating a control command for a control device that controls a holding device for a robot and a robot arm having a flexible drive mechanism, the computer program comprising: A first workpiece is held by a first holding portion of a holding device for a robot attached to the robot arm; a second holding portion of the holding device for the robot attached to the robot arm is spaced a first pitch from the first holding portion, and the second holding portion holds a second workpiece at a position spaced a first pitch from the first workpiece; changing a pitch between the first workpiece and the second workpiece from the first pitch to a second pitch by a first pitch variable mechanism of the holding device for the robot attached to the robot arm; A computer program for generating control instructions to move, by the robot arm, the first workpiece held by the first holding unit while in contact with a surface of a first area of ​​a destination object, and to move the second workpiece held by the second holding unit at a position spaced the second pitch from the first workpiece while in contact with a surface of the second area of ​​the destination object.

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