JP5462856B2 - Nipping finger device - Google Patents

Description

  The present invention relates to a clamping finger device, and more particularly to a clamping finger device for clamping and transporting a rib formed on a workpiece by being attached to a robot arm.

In production lines that process and assemble multiple parts to complete products with various variations, technologies for flexibly handling various types of workpieces and efficiently transporting them are used (for example, patents). References 1, 2).
In Patent Document 1, it is possible to deal with a wide variety of workpieces by the hand portion replacement mechanism 54 that replaces the hand portion that grips the workpiece.
In Patent Document 2, the exchange time is shortened by rotating a plurality of hands by using a turret type robot hand, and selecting them by switching.

JP-A-6-262281 (FIGS. 1 and 2) Japanese Patent Laid-Open No. 10-202456 (FIGS. 1 and 2)

  However, in the hand part replacement mechanism 54 of Patent Document 1, separate hands must be prepared according to the type of work, and thus there is a problem in securing the production cost of the hand and securing the place. Further, since the structure of the turret type robot hand of Patent Document 2 is complicated, there is a problem in that the tip of the robot becomes heavy and the operation is restricted, and there is a limit to the type of switching.

  The present invention has been made in view of such a background. A single clamping finger device mounted on a robot arm can flexibly handle various workpieces having variations, and reliably holds and transports the workpiece. It is an object of the present invention to provide a clamping finger device that can be used.

In order to solve the above-mentioned problem, the invention according to claim 1 is a sandwiching finger device that is mounted on a robot arm and sandwiches and transports a sandwiched portion of a workpiece with a pair of opposing fingers. A support plate connected to the arm, a first finger disposed on the support plate and sandwiching the first sandwiched portion of the workpiece, and a second finger sandwiching the second sandwiched portion of the workpiece; a moving device for movably supporting at least one of the first finger and the second finger, a rotating device rotatably supports at least one of the first finger and the second finger, the second e Bei and posture detecting device for detecting that the first finger and the second finger is in a state of being properly aligned, and the attitude sensing device, A support shaft that is disposed on the support plate and contacts the work; an outer cylinder that supports the support shaft so that it can be moved in and out; a biasing means that biases the support shaft in a direction of pressing the work; and the support Contact detection means for detecting that the shaft is in contact with the workpiece .

  According to the invention which concerns on Claim 1, the workpiece | work was provided with the 1st finger which clamps the 1st to-be-clamped part of the said workpiece | work, and the 2nd finger to clamp the 2nd to-be-clamped part of the said workpiece | work, Therefore, various workpieces having variations can be reliably held and transported.

Further, the clamping finger device according to the present invention includes the finger moving device and the rotating device, so that the finger position is moved in accordance with the clamped portion of the workpiece, and the finger is rotated and clamped. The direction can be adjusted as appropriate.
For this reason, the clamping finger device according to the present invention can flexibly handle various workpieces having different positions and shapes of the workpiece clamping portions, and can securely clamp the workpiece clamping portion.

  The clamping finger device according to the present invention can flexibly cope with various workpieces having variations with a single clamping finger device mounted on the robot arm, and can securely hold and transport the workpiece.

  The invention according to claim 2 is the clamping finger device according to claim 1, wherein the first finger is fixed to the support plate, the second finger is supported by the rotating device, and the rotation is performed. The moving device is supported by the moving device.

  According to this configuration, the clamping finger device according to the present invention is configured such that the first finger is fixed to the support plate to be a fixed finger, and the second finger is movable by the moving device and the rotating device. By using this finger, the configuration can be simplified and the weight can be further reduced.

That is, a sandwiched portion having a common shape in various workpieces is selected as the first sandwiched portion, and the position of the first sandwiched portion and the orientation of the shape are aligned for each workpiece by the robot arm. Thus, the first finger can be a fixed finger.
On the other hand, even if the position and shape direction of the second sandwiching portion are different for each of various workpieces in the state where the position and shape orientation of the first sandwiched portion are matched, the second sandwiched portion By making the 2nd finger which pinches | interposes a movable type, it can respond to a various workpiece | work flexibly.
Thus, the clamping finger device according to the present invention can be suitably attached to the robot arm by simplifying the configuration and realizing weight reduction.

  The invention according to claim 3 is the pinching finger device according to claim 1 or 2, wherein the moving device is a linear moving device and includes a driving device.

  According to such a configuration, the sandwiching finger device according to the present invention can be reduced in weight by simplifying the configuration by configuring the moving device with a linear moving device. In addition, since the drive device for driving the linear movement device is provided, it is possible to quickly cope with various workpieces and reduce man-hours.

  The invention according to claim 4 is the pinching finger device according to claim 3, wherein the drive device is formed of an air cylinder, and further includes movement restriction means for restricting movement.

  According to such a configuration, by configuring the drive device with an air cylinder, the configuration can be simplified and the weight can be reduced. In addition, since the movement restricting means is provided, the movement can be restricted in a state of being moved and aligned by the air cylinder, so that the sandwiched portion of the workpiece can be securely held.

  The invention according to claim 5 is the clamping finger device according to any one of claims 1 to 4, wherein the rotating device includes a base member supported by the moving device, and the base member. A pivot member pivotally supported on the pivot member, a finger support member fixed to the pivot member and supporting the finger, a pivot arm connected to the finger support member, and a rotation of the pivot arm. A first spring member connected to one side of the rotational direction and biasing the rotational arm to the other side of the rotational direction; and connected to the other side of the rotational direction and on one side of the rotational direction And a second spring member to be urged.

According to such a configuration, the first arm member and the second spring member for urging the rotating arm from both sides are provided, so that the rotating arm can freely rotate and be mounted on the base member. The holding direction of the placed finger can be adjusted as appropriate.
That is, for example, even when the orientations of the shapes of the first sandwiched portion and the second sandwiched portion are different, the finger placed on the base member sandwiches the second sandwiched portion of the workpiece. When trying to apply a clamping force to the sandwiched portion, the rotational force is received counteractingly from the sandwiched portion, and the fingers are rotated so that the clamping direction of the fingers matches the shape of the sandwiched portion of the workpiece. For this reason, the clamping direction of a finger can be suitably adjusted according to the shape of the to-be-clamped part of a workpiece | work.

  In this way, the clamping finger device according to the present invention can flexibly cope with various workpieces having different positions and shapes of workpieces to be clamped and can be securely clamped.

  The invention according to claim 6 is the clamping finger device according to any one of claims 1 to 3, wherein the first sandwiched portion and the second sandwiched portion of the workpiece are the workpiece. It is characterized by being a partition-shaped rib formed so as to protrude from the surface of the wall and crawl along the surface.

  According to such a configuration, the clamping finger device according to the present invention can securely hold the workpiece by holding the workpiece at two locations by the first finger and the second finger, and the finger moving device and the rotating device. Thus, the fingers can be appropriately adjusted according to the sandwiched portion of the workpiece, and therefore can be particularly suitably used as a holding device for sandwiching and transporting the rib formed on the workpiece.

The clamping finger device according to the present invention can flexibly cope with various workpieces having variations with a single clamping finger device mounted on the robot arm, and can securely hold and transport the workpiece.
For this reason, it can apply especially suitably to a transmission case, a torque converter case, etc. which have a rib on the surface of a work and the position of this rib changes according to product variations.

It is a top view for demonstrating the usage example at the time of applying the clamping finger apparatus which concerns on embodiment of this invention to a workpiece carrying-out process. It is a principal part enlarged plan view which shows a mode that a workpiece | work is clamped with the clamping finger apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the whole structure of the clamping finger apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the movable finger of the clamping finger apparatus which concerns on embodiment of this invention, (a) is front sectional drawing, (b) is a partial top view which shows the connection part of the moving apparatus in (a), (C) is a partial bottom view which shows the finger part of (a). It is a figure which shows the rotation apparatus in the clamping finger apparatus which concerns on embodiment of this invention, (a) is a front view, (b) is a top view, (c) is a side view. It is a figure which shows the rotation apparatus in the clamping finger apparatus which concerns on embodiment of this invention, (a) is a perspective view, (b) is a cross-sectional perspective view which shows an internal structure. It is a figure which shows operation | movement of the rotation apparatus in the clamping finger apparatus which concerns on embodiment of this invention, (a) is a top view, (b) is a side view, (c) is the state before clamping, (d) is a figure. It is a typical top view which shows the state after pinching. It is a typical front view which shows operation | movement (when the rigidity of the pallet which mounts a workpiece | work is high) in the attitude | position control apparatus of the clamping finger apparatus which concerns on embodiment of this invention, (a) is a clamping finger apparatus. The state before clamping a clamping part, (b) shows the state which clamped the to-be-clamped part. It is a typical front view which shows operation | movement (when the rigidity of the pallet which mounts a workpiece | work is low) in the attitude | position control apparatus of the clamping finger apparatus which concerns on embodiment of this invention, (a) is covered with a clamping finger apparatus. The state before clamping a clamping part, (b) shows the state which clamped the to-be-clamped part. It is a fragmentary front sectional view for demonstrating operation | movement of the clamping finger apparatus which concerns on embodiment of this invention, and shows the state before clamping a workpiece | work. It is a fragmentary front sectional view for demonstrating operation | movement of the clamping finger apparatus which concerns on embodiment of this invention, and shows the state which the support shaft contact | abutted to the workpiece | work. It is a fragmentary front sectional view for demonstrating operation | movement of the clamping finger apparatus which concerns on embodiment of this invention, and shows the state which the outer cylinder of the support shaft contact | abutted to the workpiece | work. It is a fragmentary front sectional view for demonstrating operation | movement of the clamping finger apparatus which concerns on embodiment of this invention, and shows the state which clamp was completed. It is a fragmentary front sectional view for demonstrating operation | movement of the clamping finger apparatus when the workpiece | work which concerns on embodiment of this invention has produced the position shift excessively.

A workpiece clamping finger device 1 according to an embodiment of the present invention will be described in detail with reference mainly to FIGS.
As shown in FIG. 1, the clamping finger device 1 is suitable as a holding device that is mounted on the tip 102 of the robot arm 101 of the articulated robot 100 and holds and holds the rib R of the workpiece W having various variations. Can be used (see FIGS. 2 and 3).

  Specifically, as shown in FIG. 2, for example, the positions and shapes of the ribs R and R ′ formed on the two types of workpieces W and W ′ are different, and the first sandwiched portions W1 and W1 ′ The case where the position and the shape (rib direction) match but the position and the shape (rib direction) do not match in the second sandwiched portions W2 and W2 ′ will be described below.

  The articulated robot 100 includes a clamping finger device 1 in which a workpiece W placed on a pallet 201 that has been transported to a take-out position by a transport device 200 is mounted on a distal end portion 102 of a robot arm 101 (see also FIG. 3). Thus, the gripping portions W1 and W2 (see FIG. 2) of the workpiece W are gripped at two locations, the robot arm 101 is turned to release the clamping state, and is conveyed to the carry-out device 300.

  In the present embodiment, as shown in FIG. 3, the case where the clamping finger device 1 is mounted on the posture control device 2 to be described later and is mounted on the articulated robot 100 will be described, but the present invention is not limited to this. Alternatively, the clamping finger device 1 may be attached to the distal end portion 102 of the robot arm 101 without using the posture control device 2.

  The sandwiching finger device 1 sandwiches a fixed finger 11 disposed on the support plate 22 and sandwiching a first sandwiched portion W1 (see also FIG. 2) of the workpiece W and a second sandwiched portion W2 of the workpiece W. A movable finger 12 that rotates, a rotating device 7 that rotatably supports the movable finger 12, a linear moving device 8 that is a moving device that supports the rotating device 7 movably, and movement by the moving device 8 A movement restriction device 81 for restricting the movement.

The fixed fingers 11 are attached to the mounting bracket 11a fixed to the support plate 22, the finger driving mechanism 11b, a pair of sandwiching fingers 11c and 11c that sandwich the sandwiched portions W1 and W1 ′, and the sandwiching fingers 11c. Buffer member 11d.
The mounting bracket 11 a is a member for fixing the finger driving mechanism 11 b and the clamping finger 11 c to the support plate 22.

  The finger driving mechanism 11b is a mechanism for driving the clamping finger 11c, and since it is a general-purpose mechanism, illustration is omitted, but a support mechanism that supports the clamping finger 11c so that it can be opened and closed and air that opens and closes the clamping finger 11c A drive mechanism such as a cylinder is provided.

The pair of sandwiching fingers 11c and 11c are arranged to face each other, open and close by moving in the horizontal direction and moving back and forth, and opening (unclamping) or sandwiching the sandwiched portion W1. (Clamping) can be done.
The sandwiching fingers 11c and 11c can adopt various forms such as a double-opening type and a parallel opening / closing type according to the shape of the sandwiched portion W1 of the workpiece W, but are general-purpose devices and are particularly limited. Since it is not, detailed description is omitted. In addition, the sandwiching fingers 11c and 11c are positioned so as not to contact the workpiece W in a normal state. However, when excessive displacement of the workpiece W is assumed, the sandwiching fingers 11c and 11c are positioned at the distal ends of the sandwiching fingers 11c and 11c. It is desirable to provide an elastic member (not shown) such as urethane rubber.

  The buffer member 11d is made of urethane rubber or the like having flexibility so that when the sandwiched portion W1 is sandwiched, it can be firmly sandwiched by increasing the frictional resistance while preventing the sandwiched portion W1 from being damaged. It has become.

The movable finger 12 is attached to the mounting bracket 12a that is fixed to the rotating device 7, the finger driving mechanism 12b, the pair of sandwiching fingers 12c and 12c that sandwich the sandwiched portions W2 and W2 ', and the sandwiching finger 12c. 12c, and the clamping fingers 12c and 12c can be rotated in the horizontal direction by the rotation device 7 or can be moved in the horizontal direction (left and right direction in FIG. 3) by the linear movement device 8. It has become.
Since the configuration of the mounting bracket 12a, the finger drive mechanism 12b, the clamping finger 12c, and the buffer member 12d is the same as that of the fixed finger 11, detailed description thereof is omitted.

As shown in FIG. 4A, the rotation device 7 is a device that is disposed on the support plate 22 while being supported by the linear movement device 8, and supports the movable finger 12 in a freely rotatable manner.
As shown in FIG. 5, the rotation device 7 includes a base member 71 fixed to the linear movement device 8, a housing 72 fixed to the lower surface of the base member 71 with a bolt B <b> 1 (see FIG. 6B), A rotating member 74 pivotally supported on the housing 72 via a bearing 73, a finger support member 75 fixed to the rotating member 74 with a bolt B2, and a side surface of the base member 71 fixed with a bolt B3. A spring guide member 76, a turning arm 77 fixed to the finger support member 75 with a bolt B4, and a first spring member 78a for urging the turning arm 77 in one direction (the right direction in FIG. 5C). And a second spring member 78b for urging the rotating arm 77 in the other direction (the left direction in FIG. 5C).

  As shown in FIG. 7A, the rotating arm 77 is urged counterclockwise (see R1) in the rotating direction by the first spring member 78a in a plan view, and by the second spring member 78b. , Is biased clockwise (see R2). For this reason, as shown in FIG. 6, the rotating device 7 supports the finger support member 75 to which the rotation arm 77 is fixed, so that the movable finger 12 fixed to the finger support member 75 is supported. It is rotatably supported (see FIG. 4 (a)).

  With this configuration, as shown in FIG. 7C, the movable finger 12 applies the clamping force to the sandwiched portion W2 ′ in an attempt to sandwich the sandwiched portion W2 ′ of the workpiece W ′. ), The clamping force of the clamping fingers 12c and 12c is rotated so that the clamping direction of the clamping fingers 12c and 12c matches the shape of the clamping part W2 'of the workpiece W'. Functions (see also FIG. 2).

As shown in FIG. 3, the linear moving device 8 is disposed on the support plate 22 and supports the movable finger 12 supported by the rotating device 7 so as to be linearly movable from the sandwiched portion W2 to the sandwiched portion W2 ′. Device (see also FIG. 2).
As shown in FIG. 4, the linear movement device 8 is a movement that is a guide rail 82 disposed on the support plate 22, a holder 83 supported by the guide rail 82, and a movement restricting unit that restricts the movement of the holder 83. A regulating device 81, a support member 84 that is fixed to the holder 83 and supports the rotation device 7, an air cylinder 85 that is a drive source that linearly moves the support member 84, and a forward end stopper that regulates the moving end of the support member 84. 86a (see FIG. 4A) and a backward end stopper 86b (see FIGS. 4B and 2).

The guide rail 82 is disposed along a moving direction in which the movable finger 12 is moved from the sandwiched portion W2 to the sandwiched portion W2 ′, and the movable finger 12 supported by the holder 83 via the rotating device 7 is movable. To guide you.
The movement restricting device 81 is a lock device that restricts movement by clamping the holder 83 to the guide rail 82, and can be configured by various mechanisms such as an air type, an electromagnetic type, and a gear drive type.

  With this configuration, the linear movement device 8 drives the air cylinder 85 to move backward, and the movement restricting device 81 moves the holder 83 in a state where the support member 84 is in contact with the backward end stopper 86b (the state shown in FIG. 3). The portion to be clamped W2 can be clamped by the movable finger 12 by regulating. On the other hand, the linear movement device 8 drives the air cylinder 85 forward so that the movement of the holder 83 is restricted by the movement restriction device 81 in a state where the support member 84 is in contact with the forward end stopper 86a (not shown). The clamping part W2 'can be clamped.

  In the present embodiment, the uniaxial linear moving device 8 is adopted as the moving device, but the present invention is not limited to this, and the positions of the ribs R and R ′ (see FIG. 2) formed on the workpiece W are not limited thereto. Depending on the shape and the like, a 2-axis (2-dimensional) to 3-axis (X-axis, Y-axis, and Z-axis direction three-dimensional) moving device can be employed as appropriate.

  In the present embodiment, the air cylinder 85 is used as the drive source of the linear movement device 8 and the forward end stopper 86a and the backward end stopper 86b are provided and positioned. However, the present invention is not limited to this, and various driving methods are used. For example, a driving method using a ball screw and a servo motor is employed, and positioning is performed at an arbitrary position by position control, and movement is restricted by the movement restricting means, thereby sandwiching the sandwiched portion W2 ′. You can also.

  With this configuration, the clamping finger device 1 includes the linear moving device 8 that movably supports the movable finger 12 and the rotating device 7 that supports the movable finger 12, so that the position of the movable finger 12 can be set to the workpiece W, While moving according to the sandwiched portions W2 and W2 ′ of W ′, the direction in which the movable finger 12 is pivoted can be adjusted as appropriate (see FIG. 2).

  Specifically, as shown in FIG. 2, when the object to be clamped by the clamping finger device 1 is changed from the workpiece W to the workpiece W ′, the ribs of the workpiece W are formed in the clamped portion W1 of the workpiece W. The shape and orientation of R are the same as the rib R ′ of the workpiece W ′ (the robot hand 101 is aligned so as to be common), but the sandwiched portion W2 of the workpiece W and the sandwiched portion W2 ′ of the workpiece W ′ The shape and direction of the rib R of the workpiece W are different from those of the rib R ′ of the workpiece W ′.

  In the present embodiment, in the sandwiched portion W1 of the workpiece W, the shape and orientation of the rib R of the workpiece W are the same as the rib R ′ of the workpiece W ′. However, the present invention is not limited to this. The positions of the ribs R of the workpiece W and the ribs R ′ of the workpiece W ′ at the clamping portion W2 ′ of the workpiece W ′ are aligned by the robot arm 101 so as to match the sandwiched portion W1 ′ of the workpiece W ′. Alternatively, the deviation of the orientation may be corrected by the rotation device 7 or the linear movement device 8.

  The sandwiching finger device 1 is a linear moving device even when the positions of the sandwiched portions W2 and W2 ′ and the orientations of the ribs R and R ′ are different in a plurality of types of workpieces W and W ′ having such variations. 8, the movable finger 12 is moved from the position of the clamped portion W2 of the workpiece W to the position of the clamped portion W2 ′ of the workpiece W ′, and the rotating device 7 moves the rib R ′ in the clamped portion W2 ′ of the workpiece W ′. The clamping direction of the clamping fingers 12c and 12c can be suitably adjusted in accordance with the direction (see FIGS. 7C and 7D).

  Therefore, the clamping finger device 1 can flexibly cope with various workpieces W and W ′ having different positions and orientations of the sandwiched portions W2 and W2 ′ of the workpieces W and W ′, and reliably ′ To be clamped W1, W2, W1 ′, W2 ′ can be clamped.

<Attitude control device>
As shown in FIG. 2, the posture control device 2 includes a fixed plate 21 that is fixed to the tip 102 of the robot arm 101, a support plate 22 that supports the clamping finger device 1, and an elastic mechanism 3 that elastically supports the support plate 22. And a displacement detecting means 4 of the support plate 22 and a posture detecting device 6 for detecting the posture of the pinching finger device 1.
In the present embodiment, the case where the posture detection device 6 is provided will be described. However, the present invention is not limited to this. When the workpiece W is positioned on the pallet 201 (FIG. 1) in a normal state, May not include the attitude detection device 6.

The fixed plate 21 is a member that serves as a base for supporting the support plate 22 and has a rectangular shape in plan view (see FIG. 1).
The support plate 22 is elastically supported by the fixed plate 21 via elastic mechanisms 3 (see also FIG. 1) disposed at the four corners. On the support plate 22, the fixed finger 11 and the movable finger 12 that constitute the sandwiching finger device 1, and the posture detection device 6 are disposed at predetermined positions.

  As shown in FIG. 2, the elastic mechanism 3 is attached to the support plate 22 in a direction away from the fixed plate 21 (downward in FIG. 2) by a coil spring 31 disposed between the fixed plate 21 and the support plate 22. Thus, the support plate 22 is elastically supported with respect to the fixed plate 21.

  In the present embodiment, the coil spring 31 is employed as the spring member of the elastic mechanism 3, but the present invention is not limited to this, and the torsion is possible as long as the load and the amount of deflection necessary for posture control can be secured. Various spring members such as a coil spring, a leaf spring, and a disc spring can be employed. Moreover, it is not limited to a spring member, A gas spring can also be employ | adopted.

  That is, according to the work content of the work work device, a suitable posture control is realized by appropriately selecting an appropriate spring member or gas spring in consideration of a load and a deflection amount (stroke) necessary for the posture control. Since the load of the spring member is proportional to the amount of deflection, it is suitable for applications that gradually increase the attitude control force, and the gas spring can generate a constant load even if the amount of deflection changes. Suitable for applications that ensure a stable and constant attitude control from the beginning.

The displacement detection means 4 is a detection device that detects the displacement of the support plate 22 relative to the fixed plate 21, and a detection device such as a proximity sensor is used.
The displacement detection means 4 is a first detector 41 and a first detected portion 41a that detect the original position of the support plate 22, and a second position that detects a clamping position by the clamping finger device 1 (the fixed finger 11 and the movable finger 12). The detector 42 and the 2nd to-be-detected part 42a, and the 3rd detector 43 and the 3rd to-be-detected part 43a which detect the excessive displacement of the support plate 22 are provided.

  With this configuration, the support plate 22 moves in the direction approaching the fixed plate 21 from the original position shown in FIG. 10, and when the second detected portion 42 a reaches the position of the second detector 42, the clamping finger device 1 holds the clamping position. If it is detected (see FIG. 11) and the support plate 22 passes the gripping position and the third detected portion 43a reaches the position of the third detector 43, the excessive displacement of the support plate 22 can be detected ( (Refer FIG.14 (c)).

  As shown in FIG. 2, the posture detection device 6 includes a support shaft 5 that is brought into contact with the workpiece W, a flexible member 5 a provided at the tip of the support shaft 5, and an exterior that allows the support shaft 5 to be retractable. The cylinder 61, the urging means 62 that urges the support shaft 5 in the direction in which the support shaft 5 is pressed against the work W, the contact detection means 63 that detects that the support shaft 5 is in contact with the work W, and the outer cylinder 61 are illustrated. 3 and an air cylinder 64 that moves in the vertical direction.

Here, the flexible member 5a may use, for example, rubber, foamed polystyrene, sponge, or the like to relieve the impact force when the support shaft 5 is brought into contact with the workpiece W and prevent damage to the workpiece W. it can.
The air cylinder 64 is a device for allowing the outer cylinder 61 and the support shaft 5 to escape upward so that the posture detection device 6 does not interfere with the workpiece W when the clamping finger device 1 is positioned. The support shaft 5 can come into contact with the workpiece W in a state where the shaft 5 is lowered downward.

  The contact detection means 63 comprises an optical sensor or the like, and moves by a predetermined movement amount s after the support shaft 5 contacts the workpiece W (see FIG. 11A), and the tip surface of the outer cylinder 61 and the support shaft When the support shaft 5 comes into contact with the workpiece W by the detected portion 63a that has moved to the facing position in a state in which the front end surface of 5 is flush (see FIG. 12A), a predetermined movement amount is obtained. Detects movement.

  The biasing means 62 is not particularly limited, and a coil spring or the like can be adopted. However, the elastic coefficient of the biasing means 62 is smaller than the elastic coefficient of the coil spring 31 of the elastic mechanism 3 (the elasticity of the elastic mechanism 3). The coefficient is set to be larger than the elastic coefficient of the biasing means 62).

  With this configuration, as shown in FIG. 11, the coil spring 31 (see FIG. 5) is bent more than the movement amount s (see FIG. 11 (a)) that moves after the support shaft 5 contacts the workpiece W. The amount of movement s ′ (see FIG. 11B) is smaller.

  The posture detection device 6 is disposed in the vicinity of the clamping finger device 1, and the fixed finger 11 and the movable finger 12 that clamp the workpiece W are appropriately placed on the sandwiched portions W1 and W2 of the workpiece W by the contact detection means 63. It can be detected that the position is aligned.

  That is, with the tip 102 of the robot arm 101 (see FIG. 1) approaching and the support shaft 5 is in contact with the workpiece W (see FIG. 11A), the tip 102 is further moved closer to the workpiece W. Then, together with the clamping finger device 1 (fixed finger 11 and movable finger 12), the outer cylinder 61 moves downward and the support shaft 5 is accommodated in the outer cylinder 61 against the urging force of the urging means 62, The front end surface of the outer cylinder 61 and the front end surface of the support shaft 5 are flush with each other and contact the workpiece W (see FIGS. 12A and 3).

  At this time, in the clamping finger device 1 (fixed finger 11 and movable finger 12), the buffer members 11d, 1 and 2d (see FIG. 3) for clamping the workpiece W are properly inserted into the clamped portions W1 and W2 of the workpiece W. The posture detection device 6 is disposed at an appropriate position and height with respect to the clamping finger device 1 (the fixed finger 11 and the movable finger 12) so as to be in the state (see FIG. 3).

  For this reason, the posture detection device 6 contacts the state where the front end surface of the outer cylinder 61 and the front end surface of the support shaft 5 are flush with each other by a predetermined amount of movement after the support shaft 5 contacts the workpiece W. By being detected by the detection means 63, the clamping finger device 1 (the fixed finger 11 and the movable finger 12) that clamps the workpiece W is properly aligned with the clamped portions W1 and W2 of the workpiece W. Can be confirmed.

Next, an operation when the clamping finger device 1 according to the embodiment of the present invention is mounted on the posture control device 2 and applied to the articulated robot 100 will be described with reference to FIGS. 8 to 14.
<Operation of elastic mechanism 3>
First, the operation of the elastic mechanism 3 will be described with reference mainly to FIGS. FIG. 8 to be referred to is a schematic front view showing the operation of the elastic mechanism 3 when the rigidity of the pallet on which the work is placed is high, and (a) is a state before the sandwiched portion is sandwiched by the sandwiching finger device. b) shows a state in which the sandwiched portion is sandwiched. FIG. 9 is a schematic front view showing the operation of the elastic mechanism 3 when the rigidity of the pallet on which the workpiece is placed is low.
In FIGS. 8 and 9, for convenience of explanation, the inclination of the workpiece W and the like are exaggerated, but the amount of deformation is actually a small amount.

  Here, the pallet 201 (see FIG. 1) may be in various forms depending on the purpose and application. For example, when the pallet 201 is made of a metal angle material or the like, the pallet 201 generally has high rigidity and is made of synthetic resin. Since the rigidity of the elastic mechanism 3 is low, the elastic mechanism 3 has different functions depending on the relationship between the urging force (elastic supporting force) of the elastic mechanism 3 and the rigidity of the pallet 201 as follows.

<When pallet rigidity is high>
When the rigidity of the pallet on which the workpiece is placed is high, the elastic mechanism 3 tends to operate so as to control the posture of the clamping finger device 1 in accordance with the posture of the workpiece W.
That is, as shown in FIG. 1, for example, when the elastic mechanism 3 tries to pinch the workpiece W placed on the pallet 201 with the pinching finger device 1 (the fixed finger 11 and the movable finger 12), When the mounted work W is deviated or tilted from a predetermined position, the posture of the clamping finger device 1 with respect to the work W is controlled according to the amount of deviation due to this deviation or the like.

  Specifically, as shown in FIG. 8A, when the work W has an inclination of α, the clamping finger device 1 (the fixed finger 11 and the movable finger 12) by the robot arm 101 (see FIG. 1). When the clamping finger device 1 and the workpiece W are in contact with each other when the workpiece W is to be arranged at a predetermined position, the support plate 22 is supported from the sandwiched portion W2 of the workpiece W according to the inclination angle α of the workpiece W. A moment M is applied reactively to try to rotate the.

  Then, as shown in FIG. 8B, the moment M thus applied absorbs the inclination of the angle α of the clamping finger device 1 with respect to the work W flexibly as appropriate, and the support plate 22 according to the inclination angle α. By correcting the position and the inclination angle, the posture control device 2 can suitably control the posture of the clamping finger device 1 with respect to the workpiece W.

<When pallet rigidity is low>
When the rigidity of the pallet on which the workpiece W is placed is low, the elastic mechanism 3 tends to operate so as to match the posture of the workpiece W with the clamping finger device 1.
That is, as shown in FIG. 1, for example, when the elastic mechanism 3 tries to pinch the workpiece W placed on the pallet 201 with the pinching finger device 1 (the fixed finger 11 and the movable finger 12), When the mounted workpiece W is deviated or tilted from a predetermined position, the misalignment or the like is corrected, and the workpiece W functions to match the holding finger device 1.

  Specifically, as shown in FIG. 9A, when the clamping finger device 1 (the fixed finger 11 and the movable finger 12) is to be arranged at a predetermined position with respect to the workpiece W, When the workpiece W comes into contact, the elastic mechanism 3 applies an urging force (pressing force) to the workpiece W placed on the pallet 201 (see FIG. 1) at an inclination angle α by the urging force (elastic supporting force). For this reason, a moment M ′ is applied to rotate the workpiece W counterclockwise due to bending or deformation of the pallet 201.

  Then, as shown in FIG. 9B, the moment M ′ applied in this way acts so that the posture of the workpiece W becomes α ′ smaller than the inclination angle α. The position of the workpiece W can be adjusted to the clamping finger device 1 by suitably correcting the deviation from the workpiece W.

  In the present embodiment, for the sake of convenience, the case where the rigidity of the pallet 201 is high and the case where the rigidity is low has been described separately. However, in actuality, the pallet 201 is not strictly distinguished. It is possible to control the clamping finger device 1 so as to face the workpiece W appropriately by appropriately adjusting the urging force by the elastic mechanism 3.

<Relationship between the operations of the clamping finger device and the posture detection device>
The relationship between the operations of the clamping finger device 1 and the posture detection device 6 will be described with reference to FIGS. 10 to 13. 10 is a state before clamping the workpiece, FIG. 11 is a state in which the support shaft is in contact with the workpiece, FIG. 12 is a state in which the outer cylinder of the support shaft is in contact with the workpiece, and FIG. It is a partial front sectional view showing the completed state.
In addition, regarding the relationship between the operations of the clamping finger device 1 and the posture detection device 6, except for the rotation operation of the movable finger 12 by the rotation device 7 (see FIGS. 7C and 7D), even the fixed finger 11. Since the same applies to the movable finger 12, for convenience of explanation, only the fixed finger 11 (the movable finger 12 is not shown) will be described in detail.

  From the state in which the fixed finger 11 (similarly to the movable finger 12, the clamping finger device 1) does not come into contact with the work W (FIG. 10A), the tip 102 of the robot arm 101 is touched until the support shaft 5 comes into contact with the work W. When the tip portion 102 is further moved by s in the direction approaching the workpiece W in the close state (FIG. 11 (a)), as shown in FIG. 12 (a), it is removed together with the fixed finger 11 (holding finger device 1). The cylinder 61 moves downward in FIG. 3 so that the support shaft 5 is accommodated in the outer cylinder 61 against the urging force of the urging means 62, and the distal end surface of the outer cylinder 61 and the distal end surface of the support shaft 5 are flush with each other. And comes into contact with the workpiece W.

  Then, the contact detection means 63 detects a state in which the front end surface of the outer cylinder 61 and the front end surface of the support shaft 5 are flush with each other. In other words, the contact detection means 63 detects that the support shaft 5 has moved by a predetermined amount of movement after contacting the workpiece W by the detected portion 63a that has moved to the facing position.

  On the other hand, as shown in FIG. 12 (b), the displacement detection means 4 is moved to a position where the second detector 42 that detects the clamping position by the fixed finger 11 (the clamping finger device 1) has faced. The presence of the unit 42a is detected. In this way, the attitude control device 2 confirms that the fixed finger 11 (the clamping finger device 1) has been positioned at the proper clamping position.

  At this time, if the fixed finger 11 (clamping finger device 1) is in a state where it is positioned at a regular clamping position, the clamping finger 11c of the fixed finger 11 can properly clamp the clamped portion W1 of the workpiece W. It has become.

  In this way, the attitude detection device 6 moves a predetermined amount after the support shaft 5 abuts against the workpiece W, and the state where the tip surface of the outer cylinder 61 and the tip surface of the support shaft 5 are flush with each other. By detecting with the contact detection means 63, it can confirm that the fixed finger 11 (clamping finger apparatus 1) is in the state which can clamp the to-be-clamped part W1 of the workpiece | work W appropriately.

  Then, as shown in FIG. 13, in a state where the fixed finger 11 (the clamping finger device 1) is positioned in a predetermined posture with respect to the workpiece W, the fixing finger 11 is clamped by the finger driving mechanism 11b. Is moved in the closing direction (see FIG. 13A), and the clamped portion W1 of the workpiece W is clamped.

<Operation when the workpiece is excessively displaced>
The operation of the attitude control device 2 of the clamping finger device 1 when the workpiece W placed on the pallet 201 in FIG. 1 is excessively displaced due to vibration or external factors will be described with reference to FIG.
The posture control device 2 detects the state by the posture detection device 6 and the displacement detection means 4 when the work W that cannot be posture-controlled by the elastic mechanism 3 is excessively displaced.

  When the workpiece W is excessively deviated from the predetermined placement state, as shown in FIG. 14A, when the fixed finger 11 (the clamping finger device 1) attempts to approach the sandwiched portion W1 of the workpiece W. Since the workpiece W is excessively displaced, the fixed finger 11 comes into contact with the sandwiched portion W1 of the workpiece W.

  In a state where the fixed finger 11 is in contact with the sandwiched portion W1 of the workpiece W, the tip end portion 102 of the robot arm 101 is moved so as to approach the support shaft 5 until it contacts the workpiece W. FIG. As shown, the support shaft 5 cannot be brought into contact with the workpiece W.

  For this reason, the contact detection means 63 cannot detect a state in which the support shaft 5 is moved by a predetermined movement amount s and the front end surface of the outer cylinder 61 and the front end surface of the support shaft 5 are flush with each other. .

  The support plate 22 is detected by the second detected portion 42a that has been moved to a position where the second detector 42 faces by the displacement detection means 4 without detecting that the support shaft 5 is in contact with the workpiece W. Is detected to have moved to the workpiece gripping position.

  However, even if the displacement detector 4 detects that the support plate 22 has been displaced to the workpiece clamping position by the second detector 42, the contact detector 63 indicates that the support shaft 5 is in contact with the workpiece W. Since it is not detected, it cannot be determined that the clamping finger device 1 is positioned at a normal position with respect to the workpiece W.

  For this reason, when the distal end portion 102 of the robot arm 101 is further moved, the attitude control device 2 has moved to a position where the third detector 43 faces by the displacement detection means 4 as shown in FIG. An excessive displacement of the support plate 22 is detected by the third detected portion 43a.

  In this way, the posture control device 2 detects the excessive displacement of the support plate 22 by the displacement detection unit 4 in a state where the contact detection unit 63 does not detect that the support shaft 5 is in contact with the workpiece W. Thus, it is determined that the workpiece W is excessively displaced, and an excessive load generated when the fixed finger 11 (the clamping finger device 1) tries to clamp the clamped portion W1 of the workpiece W is detected and avoided in advance. be able to.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be implemented with appropriate modifications.
For example, in the above-described embodiment, the clamping finger device 1 clamps the workpiece W at two locations by the fixed finger 11 and the movable finger 12 (see FIG. 1), but is not limited to this, and a common object When there is no clamping part W1, both may be the movable fingers 12. Further, the number of the fixed fingers 11 to the movable fingers 12 may be increased as appropriate according to the shape of the workpiece W, and may be clamped at three or more locations.

DESCRIPTION OF SYMBOLS 1 Nipping finger apparatus 2 Attitude control apparatus 3 Elastic mechanism 4 Displacement detection means 5 Support shaft 6 Attitude detection apparatus 7 Rotation apparatus 8 Linear movement apparatus (movement apparatus)
11 Fixed finger (first finger)
12 Movable finger (second finger)
21 Fixed plate 22 Support plate 64 Air cylinder (drive device)
71 Base member 72 Housing 73 Bearing 74 Rotating member 75 Finger support member 76 Guide member 77 Rotating arm 78a First spring member 78b Second spring member 81 Movement restricting device (movement restricting means)
82 Guide rail 83 Holder 84 Support member 85 Air cylinder 86a Advance end stopper 86b Retreat end stopper 87 Rotating device 100 Articulated robot 101 Robot arm R, R 'Rib W, W' Work W1, W2 Clamped part W1 ', W2 ′ Clamped part

Claims (6)

A sandwiching finger device that is mounted on a robot arm and sandwiches and conveys a sandwiched portion of a workpiece with a pair of opposing fingers,
A support plate coupled to the robot arm;
A first finger disposed on the support plate and sandwiching the first sandwiched portion of the workpiece; and a second finger sandwiching the second sandwiched portion of the workpiece;
A moving device that movably supports at least one of the first finger and the second finger;
A rotating device that rotatably supports at least one of the first finger and the second finger;
E Bei and a posture detection device for detecting that said first finger and said second finger are in a state of being properly aligned,
The posture detection device is
A support shaft disposed on the support plate and brought into contact with the workpiece;
An outer cylinder that supports the support shaft so that it can freely move in and out,
An urging means for urging the support shaft in a direction in which the support shaft is pressed against the workpiece;
Contact detection means for detecting that the support shaft is in contact with the workpiece;
Pinching fingers apparatus characterized by comprising a. The first finger is fixed to the support plate;
The second finger is supported by the rotating device,
The rotating device is supported by the moving device;
The pinching finger device according to claim 1, wherein:   The clamping finger device according to claim 1, wherein the moving device is a linear moving device and includes a driving device.   The clamping finger device according to claim 3, wherein the driving device includes an air cylinder, and further includes a movement regulating unit that regulates movement. The rotating device is
A base member supported by the moving device;
A pivot member pivotally supported on the base member;
A finger support member fixed to the rotating member and supporting the finger;
A pivot arm coupled to the finger support member;
A first spring member connected to one side of the turning direction of the turning arm and biasing the turning arm to the other side of the turning direction, and connected to the other side of the turning direction and turned. A second spring member biasing toward one side of the direction;
The clamping finger device according to any one of claims 1 to 4, further comprising:   The first sandwiched portion and the second sandwiched portion of the workpiece are screen-shaped ribs that protrude from the surface of the workpiece and crawl along the surface. 6. The clamping finger device according to any one of items 5.

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