JP5592915B2 - Work gripping device - Google Patents

Description

  The present invention relates to a workpiece gripping device, and more particularly to a workpiece gripping device that is mounted on a robot arm to grip and transport various workpieces.

  In a production line in which a plurality of parts are processed and assembled to complete a product having various variations, a technique for gripping and transporting the workpiece in a flexible manner corresponding to a variety of workpieces is employed.

  For example, in the third page, lower left column, lines 10 to 14 of Patent Document 1, “the arrangement position of the three fingertip members is changed to an arrangement state suitable for holding according to the shape of the workpiece to be held. This provides a robot hand and a gripping method that can grip a workpiece reliably ”.

JP-A-4-82686

  However, in the robot hand described in Patent Document 1, three drive motors are installed to change the arrangement position of the three fingertip members, and the hand attached to the robot arm is large, heavy, and complicated. There is a problem of becoming. For this reason, there is a possibility of causing restrictions on the operation of the robot tip, an increase in power consumption, a failure, and the like.

  In addition, the robot hand described in Patent Document 1 is a pin member provided so as to be able to protrude from the fingertip member because the hand is larger and heavier when the workpiece is large and heavy, and is difficult to handle. Gripping a small and lightweight workpiece from the point of adopting a configuration for gripping the workpiece (see page 4, lower right column, lines 5-9, page 5, upper right column, line 20 to lower left column, line 5). However, it is thought that only.

  The present invention has been made in view of such circumstances, and is a lightweight that can flexibly handle various workpieces with a single workpiece gripping device attached to a robot arm and can securely hold and transport the workpiece. It is an object of the present invention to provide a workpiece gripping device suitable for the manufacturing.

In order to solve the above-mentioned problem, the invention according to claim 1 is a workpiece gripping device for gripping and transporting various workpieces mounted on a robot arm, a support plate coupled to the robot arm, A first abutting portion and a second abutting portion which are disposed on the support plate and which respectively abut on the first abutted portion and the second abutted portion of the workpiece when grasping the workpiece to grasp the workpiece. A contact source and a drive source that is disposed on the support plate and generates a driving force for pressing the first contact portion against the first contacted portion of the workpiece when the workpiece is gripped. A drive mechanism that has at least one of the first contact portion and the second contact portion so as to be freely movable with respect to the support plate, and restricts free movement by the free movement mechanism. A movement restricting device, Wherein the movable mechanism, said support member being secured to the support plate, wherein is rotatably supported by the supporting member, a screw shaft having a connecting portion connectable to a drive device arranged outside the workpiece holding device And a nut member screwed onto the screw shaft, and at least one of the first contact portion and the second contact portion fixed to the nut member and freely movable. A linear motion guide device that is provided between the mounting member and the support plate and the mounting member and that guides the mounting member so as to be movable in the axial direction of the screw shaft with respect to the support plate; the movement restraining device when regulations movable by the movable mechanism, characterized by Rukoto stopping the rotation by clamping the screw shaft.

According to the present invention, since the at least one of the first contact portion and the second contact portion can be freely moved by the free movement mechanism, the first contact portion and the second contact portion of the workpiece gripping device can be moved in advance. By aligning the contact portion with the contacted portion of the workpiece and holding the position by the movement restricting device, it is possible to flexibly handle various workpieces having different shapes and sizes. .
And alignment of the 1st contact part and the 2nd contact part can be realized, for example using a drive device provided in the exterior of a work grasping device. For this reason, the workpiece gripping device according to the present invention is light in weight by providing a drive device for positioning the first abutting portion and the second abutting portion as a separate body outside the workpiece gripping device. It is possible to deal with various workpieces having variations while realizing the process.
That is, it is possible to provide a work gripping apparatus suitable for weight reduction that can flexibly handle various works with a single work gripping apparatus mounted on the robot arm and can reliably hold and transport the work.

  And a first abutting portion and a second abutting portion for gripping the workpiece by respectively contacting the first and second abutted portions of the workpiece when gripping the workpiece, Since the first contact portion is pressed against the first contacted portion of the workpiece by the driving force of the drive source, the outer surface or the inner surface of the workpiece can be gripped. Thereby, even if the workpiece gripping device is not accurately positioned with respect to the workpiece, the workpiece can be gripped. Therefore, in the manufacturing process, the work time can be shortened, and the occurrence of work mistakes in which the work cannot be gripped can be suppressed. Further, the workpiece can be reliably and easily gripped regardless of the size and weight of the workpiece. Furthermore, even if the shape of the workpiece is complicated, it is possible to secure a place where the first contact portion and the second contact portion of the workpiece gripping device are in contact with the outer surface or the inner surface of the workpiece to grip the workpiece. Easy and versatile.

Further , by connecting and operating a drive device provided outside the workpiece gripping device to the connection portion of the screw shaft, the first abutting portion and the second contact portion are caused by the screw feeding action of the screw shaft and the nut member. At least one of the contact portions can be moved in the axial direction of the screw shaft. In addition, it is possible to easily restrict the free movement by the free movement mechanism by clamping the screw shaft to stop the rotation. In this way, the free movement mechanism and the movement restricting device can have a simple and compact configuration.

The invention according to claim 2 is the workpiece gripping device according to claim 1 , wherein a trapezoidal screw is formed on the screw shaft of the free movement mechanism.

  According to the present invention, the nut member and the screw shaft can be held by the self-locking effect due to the use of the trapezoidal screw even when the power source is turned off, for example, the workpiece is detached from the workpiece gripping device, etc. It becomes possible to suppress the unexpected situation.

The invention according to claim 3 is the workpiece gripping device according to claim 1 or 2 , wherein the workpiece gripping device is disposed on the support plate and contacts an end surface of the workpiece on the side of the support plate when gripping the workpiece. A pressing member is provided.

  According to this invention, when the first abutting portion is pressed against the first abutted portion of the workpiece and the workpiece is gripped, the workpiece can be pressed by the pressing member, and the workpiece is held against the workpiece gripping device. It is possible to prevent the possibility of inclining. As a result, it is possible to avoid a situation in which the gripping posture of the workpiece changes and the work at the workpiece transfer destination is hindered.

The invention according to claim 4 is the workpiece gripping device according to claim 3 , wherein the pressing member extends from a center of the support plate along a direction outward in a radial direction. It is characterized by being respectively arranged on the opposite side of the first contact portion and the second contact portion with respect to the center of the plate.

  According to the present invention, it is possible to flexibly handle various workpieces having different sizes and shapes, and to press the workpiece with the pressing member. In addition, when gripping a workpiece, the side opposite to the contacted part of the workpiece can be pressed against the center of the support plate with a pressing member, and changes in the gripping posture of the workpiece can be more effectively suppressed. It becomes.

The invention according to claim 5 is the workpiece gripping device according to any one of claims 1 to 4 , comprising a connecting member that connects the support plate and the drive mechanism, and the connecting member and installation direction in the supporting plate the support plate in a parallel plane to the drive mechanism, that is configured to be changed by the connection member with the drive mechanism are predetermined angle in said plane Features.

  According to this invention, when the first contact portion is pressed against the first contacted portion of the workpiece, the pressing direction of the first contact portion is changed to the direction approaching the center of the workpiece or the center of the workpiece. It can be set in various directions such as a direction away from the camera. Therefore, the pressing direction can be adjusted according to the type of workpiece, and the workpiece can be held more reliably.

The invention according to claim 6 is the workpiece gripping device according to any one of claims 1 to 5 , wherein the first contact portion and the second contact portion are the same as the workpiece. The contact surface is made of resin and is detachable from the workpiece gripping device.

  According to the present invention, since the first contact portion and the second contact portion whose contact surfaces with the workpiece are made of resin are brought into contact with the workpiece, the workpiece can be gripped without being damaged. . In addition, since the first contact portion and the second contact portion are frequently in contact with the workpiece, the first contact portion and the second contact portion can be easily exchanged when there is a possibility of damage or damage by making it detachable from the workpiece gripping device. It is possible to hold the workpiece more reliably.

The invention according to claim 7 is the workpiece gripping device according to any one of claims 1 to 6 , wherein the workpiece has a shell portion having a shell shape, and the workpiece The first abutted portion and the second abutted portion are respectively located on the outer surface or the inner surface of the shell portion.

  According to the present invention, the work can be securely held by gripping the outer surface or the inner surface of the shell portion having a shell shape. Therefore, it is composed of a so-called shell structure (shell structure), and as a workpiece gripping device for gripping and transporting a workpiece such as a transmission case or a torque converter case whose shape and size of the shell portion changes according to product variations, It can be particularly preferably used.

  According to the present invention, it is possible to provide a work gripping apparatus suitable for weight reduction, which can flexibly handle various works with a single work gripping apparatus mounted on a robot arm and can securely hold and transport the work. Can do.

It is a top view for demonstrating the usage example at the time of applying the workpiece holding apparatus which concerns on one Embodiment of this invention to a workpiece carrying-out process. It is a schematic plan view for demonstrating a mode that a workpiece | work is gripped with the workpiece | work holding apparatus shown by FIG. It is a schematic perspective view of the workpiece | work holding apparatus shown by FIG. It is a schematic bottom view of the workpiece | work holding apparatus shown by FIG. It is sectional drawing which follows the VO line of FIG. FIG. 6 is a plan view of FIG. 5. FIG. 6 is a left side view of FIG. 5. FIG. 6 is a schematic perspective view showing the periphery of the arm of the drive mechanism shown in FIG. 5 as viewed obliquely from below. It is sectional drawing which follows the IX-IX line of FIG. It is sectional drawing which follows the OX line | wire of FIG. It is sectional drawing which follows the O-XI line of FIG. FIG. 12 is a bottom view of FIG. 11. It is a right view of FIG. It is the schematic perspective view seen from the slanting lower part which shows the arm periphery of the modification of a drive mechanism. It is the figure seen from the arm side of the drive mechanism which concerns on a modification. It is sectional drawing which follows the XVI-XVI line | wire of FIG. (A) (b) is sectional drawing which shows typically the modification of the attachment structure of a drive mechanism. (A)-(c) is a schematic plan view for demonstrating the variation of the holding | grip method of a workpiece | work.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a plan view for explaining an example of use when a workpiece gripping apparatus according to an embodiment of the present invention is applied to a workpiece unloading process. FIG. 2 is a schematic plan view for explaining a state in which a workpiece is gripped by the workpiece gripping apparatus shown in FIG. FIG. 3 is a schematic perspective view of the workpiece gripping apparatus shown in FIG. FIG. 4 is a schematic bottom view of the workpiece gripping apparatus shown in FIG.

  As shown in FIG. 1, the workpiece gripping device 1 is suitable as a holding device (robot hand) that is attached to the tip 102 of the robot arm 101 of the articulated robot 100 and grips and holds the workpiece W having various variations. Can be used for

  The articulated robot 100 grips the workpiece W, which has been transported to the take-out position by the transport device 200 such as a roller conveyor, by the workpiece gripping device 1 attached to the tip portion 102 of the robot arm 101, and turns the robot arm 101. It is in charge of the process of transporting the workpiece W to the next process by moving it.

  As shown in FIGS. 1 and 2, the workpiece gripping device 1 is provided on the support plate 2 connected to the robot arm 101 and the support plate 2, and the workpiece W is first contacted when the workpiece W is gripped. Drive side contact portion (first contact portion) 11 (see also FIG. 5) and receiving side contact with the portion W1 and the second contacted portions W2 and W2 to grip the workpiece W, respectively. Contact portions (second contact portions) 12 and 12. In addition, the code | symbol "8" in FIG. 2 shows the pressing member 8 mentioned later. Further, the drive-side contact portion 11 and the receiving-side contact portions 12 and 12 are respectively connected to two points in FIG. 2 according to the type of the workpiece W by the free movement mechanisms 5a and 5b (see FIG. It can be moved in the direction of the arrow indicated by the chain line.

  In the present embodiment, the workpiece W is constituted by a so-called shell structure (shell structure), and has a shell portion (rib-like wall portion) S exhibiting a shell shape. Examples of the workpiece W include a transmission case and a torque converter case. Here, the first contacted part W1 and the second contacted parts W2, W2 of the workpiece W are located on the outer surface of the shell part S, respectively.

  As shown in FIGS. 3 and 4, the support plate 2 has a substantially triangular plate shape, and is connected to the distal end portion 102 of the robot arm 101 via a substantially cylindrical mounting portion 21. 4 indicates the center of the support plate 2, that is, the center of the attachment portion 21 to which the distal end portion 102 of the robot arm 101 is coupled. Here, the drive-side contact portion 11 and the receiving-side contact portions 12, 12 are arranged at substantially equal angle (120 degrees) intervals in the circumferential direction around the center O of the support plate 2. However, it does not necessarily have to be equiangular intervals.

  Further, the workpiece gripping device 1 is disposed on the support plate 2, and when the workpiece W is gripped, the driving mechanism 3 that presses the driving-side contact portion 11 against the first contacted portion W <b> 1 of the workpiece W; Movement mechanism 5a, 5b for supporting the abutting portion 11 and the receiving-side abutting portions 12, 12 with respect to the support plate 2 so as to be freely movable, and movement regulation for restricting the free movement by the free movement mechanisms 5a, 5b. Devices 71, 71.

  FIG. 5 is a cross-sectional view taken along line VO in FIG. 6 is a plan view of FIG. FIG. 7 is a left side view of FIG. FIG. 8 is a schematic perspective view showing the periphery of the arm of the drive mechanism shown in FIG. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG.

  As shown in FIGS. 5 to 7, the free movement mechanism 5 a includes support members 51 a and 51 b that are fixed to the support plate 2, a screw shaft 52 that is rotatably supported by the support members 51 a and 51 b, and a screw shaft 52. A nut member 53 that is screwed to the nut member 53, a mounting member 54 a that is fixed to the nut member 53 and is provided with the driving mechanism 3 to which the driving-side contact portion 11 is attached, and the mounting member 54 a to the support plate 2. And a linear motion guide device 55 (see FIG. 6) for guiding the screw shaft 52 so as to be movable in the axial direction.

  The nut member 53 and the attachment member 54a are fixed by, for example, a screw member 58 (see FIG. 6). In addition, the code | symbol 22 in FIG. 6 shows the escape hole required in the assembly operation | work of the workpiece | work holding device 1. FIG.

  The screw shaft 52 includes a connecting portion 52 a that can be connected to a rotation shaft (not shown) of a driving device provided outside the workpiece gripping device 1. The connecting portion 52a can be engaged with an engaging portion (not shown) provided on a rotating shaft of an external driving device so that a rotational force can be transmitted.

  The linear motion guide device 55 is provided between the support plate 2 and the mounting member 54a, and the guide rail 56 disposed on the lower surface of the support plate 2 along the axial direction of the screw shaft 52, and the mounting member 54a. And a holder 57 that is movably disposed along the guide rail 56.

  The movement restricting device 71 is installed on the outer edge of the support plate 2 via the mounting plate 23 so that the screw shaft 52 passes through the inside of the movement restricting device 71. The movement restricting device 71 clamps the screw shaft 52 and stops the rotation when restricting the free movement by the free movement mechanism 5a. Here, the movement restricting device 71 is a pneumatic device and operates by air pressure. For example, the movement regulating device 71 opens the clamp portion that clamps the screw shaft 52 against the urging force of a spring member (none of which is shown) by supplying air from the air supply port 71a. The clamp portion is closed by the urging force of the spring member to clamp the screw shaft 52 by stopping the air supply from the air supply port 71a, and a commercially available shaft clamp should be used. Can do. However, the structure of the movement control apparatus 71 is not limited to this.

  According to the above-described configuration, the screw shaft 52 and the nut member 53 are operated by connecting and operating a drive device (not shown) provided outside the workpiece gripping device 1 to the connection portion 52a of the screw shaft 52. The drive-side contact portion 11 can be moved in the axial direction of the screw shaft 52 by the screw feeding action. However, it is also possible for the operator to move and adjust the drive-side contact portion 11 by rotating the connection portion 52a using a tool. In addition, by freely clamping the screw shaft 52 and stopping the rotation, the free movement by the free movement mechanism 5a can be easily regulated. In this way, the free movement mechanism 5a and the movement restricting device 71 can have a simple and compact configuration.

  The screw shaft 52 is formed with a trapezoidal screw that is screwed into the nut member 53 and has a trapezoidal cross section. A trapezoidal screw has a smaller apex angle of the thread than a general triangular screw, and the slope of the thread is tight. Therefore, the nut member 53 and the screw shaft 52 can be held by the self-locking effect due to the use of the trapezoidal screw, and for example, an unexpected situation such as dropping of the workpiece W from the workpiece gripping device 1 can be suppressed. Is possible.

  As shown in FIGS. 5, 7, and 8, the drive mechanism 3 is moved in the axial direction by the drive source 31 that generates the drive force, the main body 32 to which the drive source 31 is attached, and the drive force of the drive source 31. A shaft 33 to be moved, and an arm 35 arranged to be swingable around a pin (fulcrum) 34 provided on the main body 32. At the time of gripping the workpiece W, one end side (upper end side) of the arm 35 is pressed leftward in FIG. 5 by the shaft 33 and the other end side (lower end side) pushes the contact portion 11 on the driving side to the workpiece. It is comprised so that it may press toward W. According to such a configuration, the work W can be reliably held by effectively utilizing the space occupied by the drive mechanism 3, and the drive mechanism 3 can be made compact.

  The drive mechanism 3 includes a drive gear 36 that is rotated by the driving force of the drive source 31 and a nut portion 37 that is fixed to the main body portion 32. A driven gear 38 that meshes with the drive gear 36 is fixed to the shaft 33, and an external thread 39 that engages with the nut portion 37 is formed on the outer peripheral surface of the shaft 33.

  According to such a configuration, the drive gear 36 is rotated by the driving force of the drive source 31 and the driven gear 38 fixed to the shaft 33 is rotated, whereby the shaft 33 and the nut portion 37 in which the male screw 39 is formed. The shaft 33 can be moved in the axial direction by the screw feeding action. In this way, the drive mechanism 3 can have a simple and more compact configuration.

  The main body portion 32 includes a housing 32a in which the drive gear 36, the driven gear 38, and the nut portion 37 are disposed, and a cover 32b that is attached to the opening end side of the housing 32a. A pair of support plate portions 32c for supporting the pins 34 are formed on the arm 35 side of the housing 32a. The drive source 31 and the movement restriction device 72 are attached to the cover 32b by, for example, screw fastening.

  Here, the drive source 31 is a pneumatic device and operates by air pressure. For example, the drive source 31 rotates the drive gear 36 by a predetermined angle (for example, 180 degrees) clockwise by supplying air from the air supply port 31a, while the drive gear 36 is supplied by supplying air from the air supply port 31b. Is rotated counterclockwise by a predetermined angle (for example, 180 degrees), and a commercially available rotary actuator can be used. However, the configuration of the drive source 31 is not limited to this.

  The movement restricting device 72 is installed such that the shaft 33 passes through the inside of the movement restricting device 72. The movement restricting device 72 is used to clamp the shaft 33 to stop the rotation and maintain the unclamped state of the workpiece W when the drive-side contact portion 11 is separated from the workpiece W. Here, the movement restricting device 72 is a pneumatic device and operates by air pressure. As the movement restricting device 72, for example, one having the same structure as that of the movement restricting device 71 described above can be used, but the configuration of the movement restricting device 72 is not limited to this.

  The external thread 39 formed on the shaft 33 is a trapezoidal screw that is screwed into the nut portion 37 and has a trapezoidal cross section. Accordingly, the nut portion 37 and the shaft 33 can be held by the self-locking effect due to the use of the trapezoidal screw, and for example, an unexpected situation such as dropping of the workpiece W from the workpiece gripping device 1 can be suppressed. It becomes possible.

  Here, the contact portion 11 on the driving side has a cylindrical shape, and the contact surface with the workpiece W is made of resin. Thereby, the workpiece W can be gripped without being damaged. Specifically, the contact portion 11 has an outer layer 11a formed from a resin and an inner layer 11b formed from a metal disposed inside the outer layer 11a (see FIG. 7). By forming only the outer layer 11a from the resin in this way, it is possible to suppress the possibility of deformation or cracks occurring in the resin member due to, for example, an impact during gripping. Examples of the material of the outer layer 11a of the contact portion 11 include polyacetal resin (POM), polyamide resin (PA), tetrafluoroethylene resin (PTFE), and the like. However, the contact portion 11 may be formed of another material having a hardness lower than that of the workpiece W.

  The drive-side contact portion 11 is fixed to the lower end of the arm 35 by a screw member 42 with a cylindrical collar 41 interposed therebetween, and is attachable to and detachable from the workpiece gripping device 1. Therefore, the abutting portion 11 is in frequent contact with the workpiece W, but can be easily replaced when there is damage or there is a possibility that the workpiece W can be held more reliably.

  As shown in FIGS. 5 and 9, the drive mechanism 3 has a connection mechanism 43 that connects the tip end side of the shaft 33 and the upper end side of the arm 35. The coupling mechanism 43 includes an annular groove 43a formed in the circumferential direction on the outer peripheral surface on the distal end side of the shaft 33, and a pin 43b provided on the upper end side of the arm 35 and engaged with the groove 43a. Have. The coupling mechanism 43 is disposed in a circular recess 44 formed on the upper end side of the arm 35, and the pin 43 b is provided so as to protrude radially inward from the inner surface of the recess 44.

  According to such a configuration, the distal end side of the shaft 33 and the upper end side of the arm 35 can be coupled by the coupling mechanism 43 having a simple configuration with a small number of parts. Then, by moving the shaft 33 to the opposite side of the arm 35, the arm 35 is swung via the connecting mechanism 43, and the contact portion 11 on the drive side of the workpiece gripping device 1 is moved to the contact portion W1 of the workpiece W. The state can be maintained by being separated from the head.

  Further, on the bottom surface of the recess 44, for example, a disk-shaped pressed member 45 is installed by press fitting or the like. Therefore, by moving the shaft 33 toward the arm 35, the pressed member 45 is pressed by the tip of the shaft 33 to swing the arm 35, and the contact portion 11 on the driving side of the workpiece gripping device 1 is moved to the workpiece W. The contacted portion W1 can be pressed. The pressed member 45 is made of, for example, a steel plate having good wear resistance and high strength, and wear and damage can be suppressed even by frequent pressing by the tip of the shaft 33.

10 is a cross-sectional view taken along the line XX of FIG.
As shown in FIG. 10, the workpiece gripping device 1 also includes a pressing member 8 that is disposed on the support plate 2 via a support column 83. The holding member 8 comes into contact with the end surface of the workpiece W on the support plate 2 side when the workpiece W is gripped. According to such a configuration, the workpiece W can be pressed by the pressing member 8 when the workpiece W is gripped by pressing the drive-side contact portion 11 against the contacted portion W1 (see FIG. 2) of the workpiece W. It is possible to prevent the workpiece W from being inclined with respect to the workpiece gripping device 1. As a result, it is possible to avoid a situation in which the gripping posture of the workpiece W is changed and the work at the transfer destination of the workpiece W is hindered.

  The support column 83 includes a long plate member 84 that extends in a direction perpendicular to the plane of the support plate 2, and a mounting plate 85 that is fixed to the support plate 2 side of the plate member 84. The mounting plate 85 is fixed to the support plate 2 by screw fastening or the like, and the pressing member 8 is fixed to the end portion of the plate member 84 opposite to the support plate 2 by screw fastening or the like.

  The pressing member 8 is long and extends from the center O of the support plate 2 (see FIG. 4) along a direction outward in the radial direction. Accordingly, the work W can be pressed by the pressing member 8 in a flexible manner corresponding to various works W having different sizes and shapes. Further, the pressing member 8 is disposed on the opposite side of the driving-side contact portion 11 and the receiving-side contact portions 12 and 12 (see FIG. 2) with respect to the center O of the support plate 2. Specifically, the pressing member 8 is substantially equiangular (120 degrees) in the circumferential direction around the center O of the support plate 2, and has a contact portion 11 on the driving side and a contact portion 12 on the receiving side, 12 between the contact portions. Therefore, when gripping the workpiece W, the opposite side of the workpiece W against the contact portion W1, W2, W2 (see FIG. 2) with respect to the center O of the support plate 2 can be pressed by the pressing member 8, respectively. It becomes possible to more effectively suppress the change in the gripping posture of W. When the pressing member 8 is arranged, the abutting portions are set not to be opposite to each other with respect to the center O of the support plate 2.

  The pressing member 8 includes a contact portion 81 positioned on the workpiece W side and an attachment portion 82 positioned on the opposite side of the workpiece W. Here, the contact portion 81 is made of resin. Thereby, it is possible to hold the workpiece W without damaging it. As resin used as the material of the contact part 81, the thing similar to the contact part 11 is mentioned, for example. However, the contact portion 81 may be formed of another material having a lower hardness than the workpiece W. The contact portion 81 is fixed to the lower surface of the attachment portion 82 by, for example, screw fastening, and is attachable to and detachable from the workpiece gripping device 1. Therefore, the contact portion 81 can be easily replaced when there is damage or there is a possibility of the damage, and the work W can be held more reliably.

FIG. 11 is a cross-sectional view taken along the line O-XI in FIG. FIG. 12 is a bottom view of FIG. FIG. 13 is a right side view of FIG.
As shown in FIGS. 11 to 13, the free movement mechanism 5 b includes support members 51 a and 51 b that are fixed to the support plate 2, a screw shaft 52 that is rotatably supported by the support members 51 a and 51 b, and a screw shaft 52. A nut member 53 that is screwed to the nut member 53, an attachment member 54 b that is fixed to the nut member 53 and provided with the receiving side contact portion 12, and an axial direction of the screw shaft 52 with respect to the support plate 2. And a linear motion guide device 55 for movably guiding it.

  Although the size and shape of the attachment member 54b are different from the attachment member 54a in the free movement mechanism 5b, since the other structure is the same as that of the free movement mechanism 5a shown in FIGS. 5-7, detailed description is abbreviate | omitted. . Moreover, since the movement control apparatus 71 shown in FIGS. 11-13 is the same as that shown in FIGS. 5-7, detailed description is abbreviate | omitted.

  The contact portion 12 on the receiving side is disposed on the attachment member 54 b via the support member 61. The column member 61 has a long cylindrical portion 62 that extends in a direction perpendicular to the plane of the mounting member 54 b, and a plate-like portion 63 that is fixed to the mounting member 54 b side of the cylindrical portion 62. The plate-like portion 63 is fixed to the attachment member 54b by screw fastening or the like. The receiving-side contact portion 12 is fixed to the end portion of the columnar portion 62 opposite to the mounting member 54b by a screw member 42 with a cylindrical collar 41 interposed therebetween. Can be removed. Therefore, the contact portion 12 can be easily replaced when there is damage or there is a risk of the damage, and the work W can be held more reliably. Here, the receiving-side contact portion 12 has the same configuration as the drive-side contact portion 11, and thus detailed description thereof is omitted.

  Next, an operation when the workpiece gripping apparatus 1 according to the present embodiment is applied to the robot arm 101 of the articulated robot 100 will be described.

  As shown in FIG. 1, the workpiece W is transported by the transport device 200 and stopped at the take-out position. Here, it is assumed that an imaging device (not shown) is mounted on the workpiece gripping device 1. Then, in a state where the workpiece W is stopped at the take-out position, the robot 100 moves the workpiece gripping device 1 on which the imaging device is mounted to the imaging position of the workpiece W, images the workpiece W with the imaging device, The posture and position of the workpiece W placed on the transport device 200 are detected from the image information thus obtained.

  Subsequently, based on the obtained image information, the robot 100 changes the posture and position of the workpiece gripping device 1 so that the workpiece gripping device 1 faces the workpiece W. At this time, the drive-side contact portion 11 is in a position facing the first contacted portion W1 (see FIG. 2) of the workpiece W with a slight gap in the horizontal direction. Further, the two receiving-side contact portions 12 and 12 have a slight gap in the horizontal direction and face the two second contacted portions W2 and W2 (see FIG. 2) of the workpiece W, respectively. In position.

  Then, when the drive source 31 of the drive mechanism 3 is operated, the shaft 33 is moved in the axial direction to press the upper end side of the arm 35, and the arm 35 is swung counterclockwise in FIG. Accordingly, the drive-side contact portion 11 provided on the lower end side of the arm 35 presses the first contacted portion W1 of the workpiece W. As a result, the drive-side contact portion 11 and the receiving-side contact portions 12 and 12 are connected to the first contacted portion W1 and the second contacted portions W2 and W2 located on the outer surface of the workpiece W, respectively. The workpiece W is gripped in contact with the three directions. At this time, the pressing member 8 also comes into contact with the end surface of the workpiece W on the support plate 2 side.

  Subsequently, the robot 100 turns, moves, etc. the robot arm 101 while holding the workpiece W with the workpiece gripping device 1, transports it to the next process, and releases the gripping state, thereby moving the workpiece W to the next process. hand over. By repeating such an operation, the robot 100 uses the workpiece gripping device 1 to grip and transport a plurality of workpieces W.

  As described above, the workpiece gripping apparatus 1 according to the present embodiment is provided on the support plate 2 connected to the robot arm 101 and the support plate 2, and the first contacted portion of the workpiece W when the workpiece W is gripped. W1 and second contacted parts W2, W2 are respectively provided on the support plate 2 and the contact part 11 on the driving side and the contact parts 12 and 12 on the receiving side for gripping the work W. A driving mechanism 3 having a driving source 31 for generating a driving force for pressing the driving-side contact portion 11 against the first contacted portion W1 of the workpiece W when gripping W; and the driving-side contact portion 11 And free-moving mechanisms 5a and 5b that support the receiving-side contact portions 12 and 12 with respect to the support plate 2, and movement-regulating devices 71 and 71 that restrict free movement by the free-moving mechanisms 5a and 5b, It is equipped with.

Therefore, according to the present embodiment, the drive-side contact portion 11 and the receiving-side contact portions 12 and 12 can be freely moved by the free movement mechanisms 5a and 5b. The abutting portion 11 and the abutting portions 12 and 12 on the receiving side are aligned corresponding to the abutted portions W1, W2 and W2 of the workpiece, and their positions are held by the movement restricting devices 71 and 71. Thus, it is possible to flexibly cope with various works W having different shapes and sizes.
The positioning of the drive-side contact portion 11 and the receiving-side contact portions 12 and 12 can be realized using, for example, a drive device (not shown) provided outside the workpiece gripping device 1. . For this reason, the workpiece gripping device 1 according to the present embodiment is provided as a separate unit without providing the workpiece gripping device 1 with a driving device for aligning the driving-side contact portion 11 and the receiving-side contact portions 12 and 12. By providing it outside, it is possible to cope with various workpieces W having variations while realizing weight reduction.
That is, the work gripping apparatus 1 suitable for weight reduction is provided, which can flexibly handle various works W with the single work gripping apparatus 1 attached to the robot arm 101 and can securely hold and transport the work W. be able to.

  Further, when the workpiece W is gripped, the driving-side abutting portion 11 and the receiving-side abutting portion that respectively abut against the first abutted portion W1 and the second abutted portion W2 of the workpiece W and grip the workpiece W. Since the contact portions 12 and 12 are provided and the drive-side contact portion 11 is pressed against the first contacted portion W1 of the workpiece W by the driving force of the drive source 31, the outer surface or the inner surface of the workpiece W is gripped. can do. Thereby, even if the workpiece gripping device 1 is not accurately positioned with respect to the workpiece W, the workpiece W can be gripped. Therefore, in the manufacturing process, the work time can be shortened, and the occurrence of work mistakes in which the workpiece W cannot be gripped can be suppressed. Further, the workpiece W can be reliably and easily gripped regardless of the size and weight of the workpiece W. Further, even if the shape of the workpiece W is complicated, a place where the contact portion 11 on the driving side and the contact portions 12 and 12 on the receiving side of the workpiece gripping device 1 are in contact with the outer surface or the inner surface of the workpiece W is secured. Therefore, it is easy to grip the workpiece W, and the versatility is excellent.

  In the present embodiment, the workpiece gripping device 1 includes a pressing member 8 that is disposed on the support plate 2 and contacts the end surface of the workpiece W on the support plate 2 side when the workpiece W is gripped. According to such a configuration, the workpiece W can be pressed by the pressing member 8 when the workpiece W is gripped by pressing the drive-side contact portion 11 against the contacted portion W1 (see FIG. 2) of the workpiece W. It is possible to prevent the workpiece W from being inclined with respect to the workpiece gripping device 1. As a result, it is possible to avoid a situation in which the gripping posture of the workpiece W is changed and the work at the transfer destination of the workpiece W is hindered.

  Moreover, in this embodiment, the pressing member 8 has a contact portion 81 located on the workpiece W side and an attachment portion 82 located on the opposite side of the workpiece W. The contact portion 81 is made of resin or the like. The workpiece W is made of a material having a lower hardness than the workpiece W and is detachable from the workpiece gripping device 1. Thereby, while being able to hold | suppress the workpiece | work W without being damaged, when there exists damage or its possibility, it can replace | exchange easily.

  Next, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration (modified example). About the same structure as embodiment mentioned above, the same code | symbol is attached | subjected, the overlapping description is abbreviate | omitted suitably, and a different point is mainly demonstrated.

FIG. 14 is a schematic perspective view showing the periphery of the arm of a modified example of the drive mechanism as viewed obliquely from below. FIG. 15 is a view as seen from the arm side of the drive mechanism according to the modification. 16 is a cross-sectional view taken along line XVI-XVI in FIG.
As shown in FIGS. 14 to 16, the driving mechanism 3 a is provided with a driving-side contact portion 11, a pressing member 46 pressed by the lower end side of the arm 35 a when gripping the workpiece W, and a gripping portion of the workpiece W And a guide mechanism 47 for guiding the pressing member 46 so as to move in a linear direction toward the workpiece W.

  The pressing member 46 includes an engaging portion 46a having a rectangular frame shape that engages so as to surround the lower end portion 35b of the arm 35a, and a moving piece 46b on which the engaging portion 46a is provided on the lower surface. The drive-side contact portion 11 is fixed to the lower surface of the moving piece 46b by a screw member 42. The guide mechanism 47 is positioned inside the pair of groove portions 47a and 47a formed on the side end surface of the moving piece 46b and the pair of rail members 48 and 48 fixed to the main body portion 32, and is located in the groove portions 47a and 47a. And a pair of side end edges 47b and 47b that are slidably fitted to each other. In this way, the pressing member 46 is slidably supported between the pair of rail members 48, 48 and is movable along the axial direction of the shaft 33.

  According to such a configuration, when the shaft 33 presses the upper end side of the arm 35a, the arm 35a swings, the lower end portion 35b of the arm 35a presses the pressing member 46, and the drive-side contact portion 11 The installed pressing member 46 is guided by the guide mechanism 47 and moves in a linear direction toward the workpiece W. Thereby, the contact portion 11 on the drive side of the workpiece gripping device 1 can be pressed in a substantially vertical linear direction with respect to the contacted portion W1 of the workpiece W, and the workpiece W can be held more reliably. .

17 (a) and 17 (b) are cross-sectional views schematically showing modifications of the drive mechanism mounting structure. In FIG. 17, each part is drawn with appropriate enlargement, reduction, simplification, and the like.
In the modification shown in FIG. 17, a connecting member 24 that connects the support plate 2 and the drive mechanism 3 is provided between the support plate 2 and the drive mechanism 3. The support members 51 a and 51 b are fixed to the connection member 24 by the screw member 25, and the connection member 24 is fixed to the support plate 2 by the screw member 26. That is, the support members 51 a and 51 b are fixed to the support plate 2 via the connecting member 24. Although not shown in FIG. 17, the guide rail 56 (see FIG. 7) is fixed to the lower surface of the connecting member 24. That is, the guide rail 56 is disposed on the support plate 2 along the axial direction of the screw shaft 52 via the connecting member 24.

  And the installation direction in the plane parallel to this support plate 2 with respect to the support plate 2 of the connection member 24 is comprised so that change is possible when the connection member 24 rotates a predetermined angle within the said plane. According to such a configuration, when the driving-side contact portion 11 is pressed against the first contacted portion W1 of the workpiece W, the pressing direction of the driving-side contact portion 11 is set to the center of the workpiece W. It can be set in various directions such as a direction approaching (see FIG. 17A) and a direction away from the center of the workpiece W (see FIG. 17B). Therefore, the pressing direction can be adjusted according to the type of the workpiece W, and the workpiece W can be held more reliably.

  Specifically, here, the screw members 26 are disposed at four positions corresponding to the apexes of a quadrangle in a plane parallel to the support plate 2. Therefore, if the screw member 26 is removed and the connecting member 24 is rotated 180 degrees in a plane parallel to the support plate 2 and then the connecting member 24 is fixed to the support plate 2 again by the screw member 26, the contact on the driving side is achieved. The pressing direction of the part 11 can be changed to the opposite direction by 180 degrees. Thereby, the contact part 11 on the driving side can be pressed against both the outer surface and the inner surface of the workpiece W by the single workpiece gripping device 1, and both the outer surface and the inner surface of the workpiece W can be gripped. It becomes possible. Note that the screw members 26 may be arranged at a plurality of locations at equal angular intervals on the circumference in a plane parallel to the support plate 2. In this way, it becomes possible to change the pressing direction of the contact portion 11 on the driving side by an integral multiple of the angular interval between the adjacent screw members 26.

  Here, the main body 32 of the drive mechanism 3 is configured to be fixed to the mounting member 54a by the screw members 27 disposed at four positions corresponding to the vertices of a quadrangle in a plane parallel to the mounting member 54a. (See FIG. 17). For this reason, if the screw member 27 is removed and the drive mechanism 3 is rotated 180 degrees in a plane parallel to the mounting member 54a and then the drive mechanism 3 is fixed again to the mounting member 54a with the screw member 27, the driving side It is possible to change the pressing direction of the contact portion 11 to the opposite direction by 180 degrees. In this case, the attachment member 54 a functions as the connecting member 24 that is disposed between the support plate 2 and the drive mechanism 3 and connects the support plate 2 and the drive mechanism 3. In addition, the screw member 27 may be arrange | positioned in multiple places at equal angular intervals on the circumference in the plane parallel to the attachment member 54a.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the structure described in the said embodiment (a modification is included), The above-mentioned structure is combined thru | or selected suitably. In the range which does not deviate from the meaning, the structure can be changed suitably.

For example, in FIG. 2, the workpiece gripping apparatus 1 grips the workpiece W by bringing the driving-side abutting portion 11 and the receiving-side abutting portions 12 and 12 into contact with the outer surface of the shell portion S of the workpiece W, respectively. Although described, the present invention is not limited to this.
18A to 18C are schematic plan views for explaining variations of the workpiece gripping method. In addition, the arrow in FIG. 18 shows the pressing direction to the workpiece | work W by the contact part 11 by the side of a drive.

  As shown in FIG. 18 (a), the workpiece gripping device 1 has a contact portion 11 on the driving side and a contact portion 12 on the receiving side on the outer surface of a workpiece W having a shell structure, for example, having a solid cylindrical shape. , 12 may be used to hold the workpiece W by contacting each other. Further, as shown in FIG. 18B, the workpiece gripping device 1 causes the contact portion 11 on the driving side and the contact portions 12 and 12 on the receiving side to contact the inner surface of the shell portion S of the workpiece W, respectively. It may be used to grip the workpiece W. In this case, for example, the drive mechanism 3 in FIG. 5 may be fixed at a position rotated 180 degrees in a plane parallel to the attachment member 54a. Further, as shown in FIG. 18C, the workpiece gripping device 1 causes the driving-side abutting portion 11 to abut on the outer surface of the shell portion S of the workpiece W and is received on the inner surface of the shell portion S of the workpiece W. The side abutting portions 12 and 12 may be brought into contact with each other to be used for gripping the workpiece W.

  In the above-described embodiment, the workpiece gripping apparatus 1 causes the three contact portions, that is, the one contact portion 11 on the driving side and the two contact portions 12 and 12 on the receiving side to contact the workpiece W. However, the present invention is not limited to this. The workpiece gripping device 1 may be configured to grip two workpieces in contact with the workpiece W, or may be configured to grip four workpieces or more in contact with the workpiece W. May be. Further, at least one of the plurality of contact portions may be the drive-side contact portion 11, and for example, all of the contact portions may be the drive-side contact portions 11. Further, in the above-described embodiment, all of the three abutting portions 11, 12, and 12 are supported by the freely moving mechanisms 5a and 5b so as to be freely movable with respect to the support plate 2. However, the present invention is not limited to this. It is not a thing. The present invention may be configured such that at least one of the plurality of abutting portions is supported by the freely moving mechanism so as to be freely movable with respect to the support plate 2.

DESCRIPTION OF SYMBOLS 1 Work holding | gripping apparatus 2 Support plate 3,3a Drive mechanism 5a, 5b Free movement mechanism 8 Pressing member 11 Contact part (1st contact part) of a drive side
12 Receiving-side contact portion (second contact portion)
24 connection member 31 drive source 32 body portion 33 shaft 34 pin 35, 35a arm 36 drive gear 37 nut portion 38 driven gear 43b pin 43a groove 43 connection mechanism 46 pressing member 47 guide mechanism 51a, 51b support member 52 screw shaft 52a connection portion 53 nut member 54a, 54b mounting member 55 linear motion guide device 71, 72 movement restriction device 100 robot 101 robot arm O center S shell portion W work W1, W2, W2 contacted portion

Claims (7)

A support plate connected to the robot arm;
A first abutting portion and a second abutting portion that are disposed on the support plate and that respectively abut against the first abutted portion and the second abutted portion of the workpiece when gripping the workpiece and grip the workpiece. A contact portion;
A drive mechanism that is disposed on the support plate and has a drive source that generates a drive force for pressing the first contact portion against the first contacted portion of the workpiece when gripping the workpiece;
A free movement mechanism that supports at least one of the first contact part and the second contact part so as to be freely movable with respect to the support plate;
A movement restriction device for restricting free movement by the free movement mechanism ,
The free movement mechanism is
A support member fixed to the support plate;
A screw shaft that is rotatably supported by the support member and includes a connecting portion that can be connected to a driving device provided outside the workpiece gripping device;
A nut member screwed onto the screw shaft;
An attachment member fixed to the nut member and provided with at least one of the first contact portion and the second contact portion that is freely movable;
A linear motion guide device that is provided between the support plate and the mounting member and guides the mounting member to the support plate so as to be movable in the axial direction of the screw shaft;
Have
The movement restricting device clamps the screw shaft to stop rotation when restricting the free movement by the free movement mechanism .
A workpiece gripping device that is mounted on a robot arm to grip and transport various workpieces. The workpiece gripping device according to claim 1 , wherein a trapezoidal screw is formed on the screw shaft of the free movement mechanism. Wherein arranged on a support plate, a work gripping device according to claim 1 or claim 2, characterized in that it comprises a pressing member which contacts the end face of the support plate side of the workpiece when the gripping of the workpiece. The pressing member extends in a radially outward direction from the center of the support plate, and the first contact portion and the second contact portion with respect to the center of the support plate. The workpiece gripping device according to claim 3 , wherein the workpiece gripping device is disposed on each side opposite to the workpiece. A connecting member for connecting the support plate and the drive mechanism;
The installation direction of the connecting member and the drive mechanism in a plane parallel to the support plate with respect to the support plate can be changed by rotating the connecting member together with the drive mechanism by a predetermined angle in the plane. it has workpiece gripping device according to any one of claims 1 to 4, characterized in. The first contact portion and the second contact portion have a contact surface made of a resin and are detachable from the workpiece gripping device. The workpiece gripping device according to any one of claims 1 to 5 . The workpiece has a shell portion exhibiting a shell shape,
The said 1st to-be-contacted part and said 2nd to-be-contacted part of the said workpiece | work are located in the outer surface or inner surface of the said shell part, respectively, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. The workpiece gripping device described in 1.

Images