JP4684160B2 - Compliance module - Google Patents

Description

  The present invention relates to a compliance module that compensates for a positional deviation of a finger module that is mounted on a robot hand and grips a workpiece, and more particularly, to a compliance module having a large compliance amount.

  As shown in FIG. 7, when the workpiece 1 is being processed while moving across the plurality of processing devices 2 to 4, when the workpiece 1 is automatically gripped (or attracted) and moved by the robot hand 5. The processing devices 2 to 4 need to be arranged with high positional accuracy. When the workpiece 1 is transported while the finger module 6 is mounted on the robot hand 5, the relative positions of the two shift due to variations in the stop position of the finger module 6, variations in the dimensions and placement positions of the workpiece 1, and so on. There was a need to fix.

  If the robot hand 5 is positioned by image processing control, the position accuracy can be improved, but there is a problem that the cost is extremely high. For this reason, the compliance module 7 is mounted between the robot hand 5 and the finger module 6 so that the displacement of the finger module 6 is mechanically compensated by the compliance module 7. This positional shift mainly includes a horizontal shift in the X direction and a Y direction, and a shift in the θ direction that rotates horizontally around the central axis.

  As shown in FIGS. 8 to 10, by inserting the guide pin 10 of the finger module 6 into the guide hole 9 of the processing jig 8, the guide hole 11 of the work 1 adsorbed to the suction pad 6 a and the processing jig 8 are inserted. The provided work guide pins 12 are aligned to position the work 1. As shown in the figure, even when the position of the guide pin 10 is displaced by ΔX with respect to the guide hole 9, the compliance module 7 compensates for the displacement of the finger module 6 at this time, and the guide pin 10 Is inserted while being guided by the chamfered portion 9 a of the guide hole, and the workpiece 1 is accurately positioned on the processing jig 8.

  After the workpiece 1 is set, when the robot hand 5 is raised and the compliance module 7 is separated from the processing jig 8, the posture of the compliance module 7 is returned to the original neutral position by the operation of the return mechanism. In addition, when the machining of the workpiece 1 is completed and the robot hand 5 again takes out the workpiece 1 from the processing jig 8 and moves up, the posture of the compliance module 7 returns to the neutral position by the operation of the return mechanism.

  As a conventional compliance module, for example, there is provided a discharge unit that holds and holds a component gripping device that grips an assembly part so as to be movable in a plane, and discharges a medium that supports the component gripping device by static pressure through a throttle. In addition, a configuration is known in which the pressure applied to supply the medium to the component gripping device is variable (see Patent Document 1).

A centering device that performs relative centering by a centering operation of an operating flange that moves relative to a fixed frame by the action of an external force, a first centering means that performs a centering operation in a lateral direction of the movable flange, and a movable flange There is also known a centering device including second centripetal means for performing centripetal movement in the tilt direction (see Patent Document 2).
Japanese Unexamined Patent Publication No. 64-16336 Japanese Patent Laid-Open No. 4-331088

  In the invention described in Patent Document 1, when a high-pressure or low-pressure regulator is connected to the solenoid valve and the next insertion operation is performed after the parts are first inserted, the position is easily displaced by the regulator. It is. However, the control mechanism by the fluid pressure is complicated, and when transporting across a plurality of devices as shown in FIG. 7, the fluid pressure condition for positioning is required in each device, and management is difficult.

  The invention described in Patent Document 2 uses an elastic body and a movable sphere as means for performing a centripetal operation (an operation for returning to the center position). In this configuration, in order to obtain a large amount of compliance, control may not be possible depending on the displacement direction. In particular, it is difficult to obtain a large amount of compliance for the θ direction that rotates horizontally. In order to obtain a large amount of compliance, it is desired to reduce the displacement force of the elastic body, but if this is done, the centripetal operation becomes slow and vibration occurs. In order to suppress this vibration, it is only necessary to deepen the receiving hole of the movable sphere and fix the movable sphere immediately, but this is not practical because the initial force for displacement is strong. In addition, since a component force acts from the diameter direction of the coil spring, an excessive force is applied to the coil spring and it is easily broken.

  Accordingly, an object of the present invention is to provide a compliance module that can obtain a large amount of compliance with a simple mechanism.

The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is a compliance module that compensates for a positional deviation of a finger module that is attached to a robot hand and grips a workpiece. In a compliance module that executes a compliance operation in the X direction and the Y direction orthogonal to each other and a compliance operation in the θ direction that rotates horizontally,
The compliance module includes a first base plate attached to a lower end portion of the robot hand, and second to fourth base plates sequentially arranged with a gap below the first base plate,
The second base plate is slidably connected in the X direction to the first base plate via a linear guide including a guide rail and a pair of slide blocks slidably attached to the guide rail. A neutral position return mechanism that connects the slide block with a tension coil spring and pulls the second base plate back to the neutral position, and a locking member that moves integrally with the slide block is fixed to each slide block, and also a compliance operation When the lower base plate slides toward the compliance operation side, one locking member and the slide block are pushed outward. When the compliance is not operating, both the slide blocks are pulled inward and the respective locking members Engage with the edges of the top and bottom base plates The neutral position holding mechanism for holding the second base plate that is configured to the neutral position so as to provided,
The third base plate is connected slidably in the Y direction with respect to the second base plate via a linear guide, similarly slidably connected to said second base plate to the X direction, the neutral position of the third base plate The respective slide blocks that are pulled back to each other are connected by tension coil springs to return the neutral position to the neutral position, and both the slide blocks that hold the third base plate at the center position are pulled inward to each locking member. A compliance module is provided in which a neutral position holding mechanism configured to be engaged with the ends of upper and lower base plates is provided , and the finger module is mounted on a fourth base plate connected to the third base plate To do.

  According to this configuration, the compliance operation in the horizontal X direction is compensated by the sliding of the second base plate via the linear guide provided between the first base plate and the second base plate, and in the horizontal Y direction. The compliance operation is compensated by sliding of the third base plate via a linear guide provided between the second base plate and the third base plate. In addition, the compliance operation in the horizontal θ direction is compensated by the rotation of the fourth base plate via the bearing portion provided between the third base plate and the fourth base plate. When the robot hand is raised, each base plate is pulled back to the neutral position by the neutral position return mechanism, and immediately stops at the neutral position by the neutral position holding mechanism.

  According to this configuration, the guide rail is fixed in the X direction on the lower surface of the first base plate, and the guide rail is fixed in the Y direction on the lower surface of the second base plate. A plurality of slide blocks are slidably attached along the respective guide rails. When the compliance operation is performed, the lower base plate slides toward the compliance operation side, and one of the locking members locked to the end of the lower base plate is slid against the bias of the tension coil spring. And are pushed out together.

  When the robot hand is raised and the compliance is not operated, the locking member pushed outward is pulled back inward integrally with the slide block by the bias of the tension coil spring, and the locking member is moved downward. Press the end of the base plate inward. The pressed lower base plate abuts against the opposite locking member and stops, and both ends of the upper and lower base plates are clamped by both locking members urged by the tension coil spring. The base plate does not vibrate at the neutral position, but stops immediately and is held at the neutral position.

  According to this configuration, the linear guide provided in the center part of the upper and lower base plates compensates for the positional deviation by the lower base plate sliding in the X direction or the Y direction during the compliance operation. Pull the lower base plate back to the neutral position. The slide support members provided on both sides of the linear guide support the upper and lower base plates so that they can slide smoothly when the upper and lower base plates slide relative to each other.

According to a second aspect of the present invention, the fourth base plate is connected to the third base plate so as to be rotatable in the θ direction via a bearing portion at the center, and is provided between the third base plate and the fourth base plate. The neutral position return mechanism includes two pairs of tension coil springs horizontally facing each other with the bearing portion interposed therebetween, and the adjacent one end portions of the respective coil springs are locked to the lower surface of the third base plate and the other adjacent end The second base plate is configured to be locked to the upper surface of the fourth base plate, and further, a pair of magnets having the attracting surfaces opposed to the third and fourth base plates are fixed to hold the fourth base plate at the center position. As the neutral position holding mechanism, when the fourth base plate is in the neutral position, either the third or fourth base plate is provided with a recess and the other base plate. The plates provide a compliance module according to claim 1, characterized in that a movable spherical body for engaging the recess.

According to this configuration, the two pairs of tension coils that are horizontally opposed to each other with the bearing portion interposed therebetween are arranged in a state in which an equal tension state is maintained, and the fourth base plate is fourth with respect to the third base plate during the compliance operation. When the base plate rotates in the θ direction, one of the pair of tension coil springs is further pulled, and the other is in a state where the tension is contracted. Therefore, when the compliance is not operated, the fourth base plate is rotated in the opposite direction and returned to the neutral position by the restoring force of both the tension coil springs to return to the uniform tension state. Further, the fourth base plate is further prevented from vibrating due to the attraction force of the pair of magnets facing the attraction surfaces.

When the fourth base plate rotated in the θ direction during the compliance operation returns to the neutral position due to the non-compliance operation, the movable sphere engages with the concave portion to reliably stop the fourth base plate at the neutral position, 4 Suppresses the swing of the base plate.

  In the present invention, as described above, the compliance operation in the horizontal X direction and the Y direction is compensated by sliding the base plate through the linear guide, and the compliance operation in the horizontal θ direction is performed by rotating the base plate through the bearing portion. Since it compensates by moving, a large amount of compliance can be obtained with a simple configuration. In addition, the base plate slides in the extension direction of the tension coil spring to perform a compliance operation, and the base plate is pulled in the contraction direction of the tension coil spring to return to the neutral position. Therefore, an unreasonable force may act on the tension coil spring. And can return to the neutral position very smoothly.

  The compliance module according to the present invention will be described below with reference to preferred embodiments. In order to achieve the object of providing a compliance module that can obtain a large amount of compliance with a simple mechanism, the present invention is a compliance module that compensates for a positional deviation of a finger module that is attached to a robot hand and grips a workpiece. In a compliance module that executes a compliance operation in the X and Y directions orthogonal to the horizontal direction and a compliance operation in the θ direction that rotates horizontally, the compliance module is a first mounted on the lower end of the robot hand. It consists of a base plate and second to fourth base plates sequentially arranged with a gap below the first base plate, and the second base plate is slidably connected in the X direction to the first base plate via a linear guide. And more A neutral position return mechanism that pulls the second base plate back to the neutral position, and a neutral position holding mechanism that holds the second base plate at the neutral position. The third base plate extends in the Y direction with respect to the second base plate via the linear guide. Further, there is provided a neutral position return mechanism that is slidably connected and pulls the third base plate back to the neutral position, and a neutral position holding mechanism that holds the third base plate in the neutral position, and the fourth base plate is interposed via a central bearing portion. A neutral position return mechanism that is connected to the third base plate so as to be rotatable in the θ direction, and further pulls the fourth base plate back to the neutral position, and a neutral position holding mechanism that holds the fourth base plate in the neutral position. This was realized by mounting the finger module on the lower part of the 4 base plate.

  FIG. 1 is a front view of a compliance module according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. As shown in FIGS. 1 to 2, the compliance module 20 includes a first base plate 21 attached to the lower end portion of the robot hand 5, and a first base plate 21 disposed sequentially with a gap below the first base plate 21. 2 base plate 22, third base plate 23, and fourth base plate 24. A finger module 6 that holds (or attracts) the workpiece 1 is attached to the lower part of the fourth base plate 24.

  The second base plate 22 is connected to the first base plate 21 via a linear guide 25 so as to be slidable in the X direction (the left-right direction in the drawing in the figure). The linear guide 25 includes a guide rail 26 fixed to either the upper or lower base plate, and a plurality of slide blocks 27 and 27 slidably attached to the guide rail 26. A steel ball is enclosed inside. Thus, the upper and lower base plates 21 and 22 are configured to be relatively smoothly moved relative to each other.

  In this embodiment, a linear guide 25 is provided substantially in the center X direction between the first base plate 21 and the second base plate 22, and the slide block 27 of the linear guide 25 moves in the X direction integrally with the slide block 27. A locking member 28 is fixedly provided, and a locking pin 29 protrudes vertically on the outer end portion of the locking member 28. The left and right slide blocks 27 or the locking members 28 are connected to each other by a tension coil spring 30 and biased inward, so that the locking member 28, the locking pin 29, and the tension coil spring attached to the linear guide 25 are connected. 30 and the like, a neutral position return mechanism and a neutral position holding mechanism described later are formed.

  A plurality of slide support members 31, 31 are provided in parallel to the linear guide 25 on both sides of the linear guide 25 (the front-rear direction in the figure). As with the linear guide 25, the slide support member 31 also supports the upper and lower base plates 21 and 22 so that they can be relatively moved relative to each other in the X direction.

  The third base plate 23 is connected to the second base plate 22 via a linear guide 32 so as to be slidable in the Y direction (the front-rear direction in the drawing in the figure). The linear guide 32 has the same configuration as the linear guide 25 described above, and includes a guide rail 33 fixed to one of the upper and lower base plates, and a plurality of slide blocks 34 and 34 slidably attached to the guide rail 33. It is made up of.

  Similarly to the linear guide 25, a linear guide 32 is provided in the central portion X direction between the second base plate 22 and the third base plate 23, and the slide block 34 of the linear guide 32 moves integrally in the Y direction. A locking member 35 is fixedly provided, and a locking pin 36 protrudes vertically from the outer end of the locking member 35. Then, the front and rear slide blocks 34 or the locking members 35 are connected by a tension coil spring 37 and urged inward, so that the locking member 35, the locking pin 36, and the tension coil spring attached to the linear guide 32 are provided. 37, etc., a neutral position return mechanism and a neutral position holding mechanism are formed.

  A plurality of slide support members 38 are provided on both sides of the linear guide 32 (in the figure, in the left-right direction in the drawing) in parallel with the linear guide 32. As with the linear guide 32, the slide support member 38 also supports the upper and lower base plates 22 and 23 so that they can be moved relatively smoothly in the Y direction. A linear guide 25 and a slide support member 31 provided between the first base plate 21 and the second base plate 22, and a linear guide 32 and a slide support member 38 provided between the second base plate 22 and the third base plate 23, respectively. Are different from each other in the X direction and the Y direction, and are arranged upside down, but the various operations and effects are exactly the same.

  The fourth base plate 24 is connected to the third base plate 23 via a central bearing portion 40 so as to be rotatable in the θ direction. The bearing portion 40 includes a shaft 41 fixed to either the upper or lower base plate, and a bearing 42 into which the shaft 41 is fitted via a bearing (not shown). The upper and lower base plates are interposed via the bearing portion 40. Thus, it is configured to be able to rotate with respect to the horizontal direction very smoothly. In this embodiment, a shaft 41 is suspended from the lower surface of the central portion of the third base plate 23, and a bearing 42 is provided on the upper surface of the central portion of the fourth base plate.

  In addition, pins 45 and 45 are respectively fixed downward near the central portions of the two opposite sides of the lower surface of the third base plate 23, and the pins 46 are respectively provided near the central portions of the two sides of the fourth base plate in a direction perpendicular thereto. 46 are fixed upward. Then, two pairs of tension coil springs 43 and 44 are arranged at positions horizontally opposed across the bearing portion 40, and adjacent one end portions 43a and 44a of the respective tension coil springs are locked to the pin 45. The other end portions 43b and 44b adjacent to each other are locked to the pin 46, thereby forming a neutral position returning mechanism.

  On the other hand, a recess 47 is provided in either the third or fourth base plate (in this case, the fourth base plate 24), and a movable sphere 48 that engages with the recess 47 is provided in the other base plate (third base plate 23). Further, a pair of magnets 49a and 49b are fixedly provided so that the upper and lower base plates face the attracting surfaces. In this embodiment, NS attracting surfaces of neodymium magnets having strong magnetic properties are arranged facing each other. A neutral position holding mechanism is formed by a combination of the concave portion 47 and the movable sphere 48 and a pair of magnets 49a and 49b having the attracting surfaces opposed to each other. Reference numeral 50 denotes a stopper that regulates the rotation range of the fourth base plate 24.

  The finger module 6 is provided with a suction pad 6a for sucking the work 1 and a guide pin 10 so that the relative position between the guide pin 10 and the guide hole 11 of the work 1 matches a preset position. Then, the work 1 is attracted to the finger module 6 and conveyed.

  Next, the compliance operation in the X direction of the compliance module 20 according to the present invention will be described with reference to FIGS. For convenience of explanation, the description of the slide support member 31 and the description of the base plate below the second base plate 2 are omitted. Moreover, although the workpiece | work 1 and the processing jig 8 show a longitudinal cross-section state, the longitudinal cross-section position is not necessarily the same location.

  FIG. 3 shows a state in which the workpiece 1 is attracted and transported by the robot hand 5, and it is assumed that the guide hole 11 of the workpiece 1 and the guide pin 12 of the processing jig 8 are displaced by ΔX. When the robot hand 5 is lowered, the guide pin 10 of the finger module 6 approaches the guide hole 9 of the processing jig 8, the compliance module 20 compensates for the positional deviation in the X direction, and the tip of the guide pin 10 guides. It is inserted into the guide hole 9 while being guided by the chamfered portion 9a of the hole.

  In detail, as shown in FIG. 4, the second base plate 22 of the compliance module 20 slides rightward in the drawing by ΔX integrally with the finger module 6 to compensate for the positional deviation of the finger module 6. To do. At this time, the locking pin 29 and the locking member 28 on the right side in the drawing that are locked to the end portion of the second base plate 22 are pressed in the right direction, and the locking member 28 is biased by the tension coil spring 30. Against this, the slide block 27 and the slide block 27 are pushed outward.

  As described above, the second base plate slides with respect to the first base plate 21 attached to the robot hand 5 via the linear guide, whereby the compliance amount of ΔX can be compensated.

  The locking member 28 pushed out to the outside is pulled back inward along the guide rail 26 integrally with the slide block 27 by the urging of the tension coil spring 30 which is a neutral position return mechanism, as shown in FIG. Return to the neutral position.

  In this state, the left and right slide blocks 27 and the locking member 28 are both pulled inward by the biasing of the tension coil spring 30 in the contracting direction, and the locking pins 29 and 29 that are neutral position holding mechanisms are the first. The both end portions of the base plate 21 and the second base plate 22 are sandwiched and pressed inward. Therefore, the second base plate 22 is quickly stopped and held at the neutral position without vibrating at the neutral position. As described above, when the compliance is not operated, the compliance module 20 quickly returns to the neutral position and stops by the operations of the neutral position return mechanism and the neutral position holding mechanism.

  The compliance operation in the Y direction by the second base plate and the third base plate is the same as the above-described compliance operation in the X direction, and a duplicate description is omitted.

  Next, a compliance operation in the θ direction of the compliance module 20 according to the present invention will be described with reference to FIG. As described above, the bearing portion 40 is provided in the center portion of the fourth base plate 24, and the two pairs of tension coil springs 43 and 44 maintain an even tension state at positions horizontally opposed across the bearing portion 40. It is installed in a state. Now, it is assumed that the fourth base plate 24 is horizontally rotated by an angle θ and moved to a position indicated by a two-dot chain line by a compliance operation. At this time, one of the opposing tension coil springs 43, 43 acts in the direction in which it is further tensioned, and the other opposing tension coil springs 44, 44 act in a direction in which tension is relaxed.

  Further, the concave portion 47 provided in the fourth base plate 24 is detached from the movable sphere 48 and moves to the position of the two-dot chain line, and one magnet 49b embedded in the fourth base plate 24 attracts the other magnet 49a. Move away from the surface in the horizontal direction to the position of the two-dot chain line. The stopper 50 also moves to the position of the two-dot chain line.

  If the robot hand 5 is raised after placing the workpiece 1 on the processing jig 8, the guide pin 10 of the finger module 6 comes out of the guide hole 9 of the processing jig 8 and becomes non-compliant, and rotates horizontally by an angle θ. The moving fourth base plate 24 is rotated in the opposite direction by the urging of two pairs of tension coil springs 43 and 44 which are neutral position return mechanisms. That is, one of the extended tension coil springs 43, 43 acts in the contraction direction, and the other tension coil spring 44, 44 that has been loosened acts in the extension direction, and the fourth base plate 24 moves to the neutral position. Return.

  When the fourth base plate returns to the neutral position, the two pairs of tension coil springs 43 and 44 act in opposite directions without stopping at the neutral position, and the fourth base plate oscillates near the neutral position. The movable sphere 48 engages with the recess 47 to stop the fourth base plate at the neutral position, and the fourth base plate is driven by the strong magnetic attraction force of the pair of magnets 49a and 49b with the attraction surfaces facing each other. The fourth base plate is reliably and promptly stopped at the neutral position.

  As described above, the compliance operation in the X direction and the Y direction orthogonal to the horizontal direction is compensated by combining the linear guide, the locking member, and the tension coil spring separately provided, and the compliance operation in the θ direction rotating horizontally. Is configured to compensate by combining two pairs of tension coil springs that are horizontally opposed across the bearing portion, a movable sphere that is engaged with the concave portion, and a pair of magnets that are opposed to the attracting surface. A large compliance amount of about 10 mm (about 1 mm in the prior art) can be obtained in the XY direction, and a larger compliance amount than in the conventional art can also be obtained in the θ direction. In addition, since the configuration is simple and the size can be reduced, the cost can be reduced and the overall weight of the robot hand can be reduced.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

The front view of the compliance module which concerns on this invention. AA sectional view taken on the line AA of FIG. Explanatory drawing which shows a compliance operation | movement. Explanatory drawing which shows a compliance operation | movement. Explanatory drawing which shows a compliance operation | movement. Explanatory drawing which shows a compliance operation | movement. Explanatory drawing of a some processing apparatus and a robot hand. Explanatory drawing of operation | movement of a compliance module. Explanatory drawing of operation | movement of a compliance module. Explanatory drawing of operation | movement of a compliance module.

Explanation of symbols

1 Work 5 Robot Hand 6 Finger Module 8 Processing Jig 9 Guide Hole 10 Guide Pin 11 Guide Hole 12 Guide Pin 20 Compliance Module 21 First Base Plate 22 Second Base Plate 23 Third Base Plate 24 Fourth Base Plate 25, 32 Linear Guides 26, 33 Guide rail 27, 34 Slide block 28, 35 Locking member 29, 36 Locking pin 30, 37 Tension coil spring 31, 38 Slide support member

Claims (2)

A compliance module that compensates for the displacement of the finger module that is attached to the robot hand and grips the workpiece, and that performs compliance operations in the X and Y directions that are orthogonal to the horizontal direction, and a compliance operation in the θ direction that rotates horizontally. In the compliance module that executes
The compliance module includes a first base plate attached to a lower end portion of the robot hand, and second to fourth base plates sequentially arranged with a gap below the first base plate,
The second base plate is slidably connected in the X direction to the first base plate via a linear guide including a guide rail and a pair of slide blocks slidably attached to the guide rail. A neutral position return mechanism that connects the slide block with a tension coil spring and pulls the second base plate back to the neutral position, and a locking member that moves integrally with the slide block is fixed to each slide block, and also a compliance operation When the lower base plate slides toward the compliance operation side, one locking member and the slide block are pushed outward. When the compliance is not operating, both the slide blocks are pulled inward and the respective locking members Engage with the edges of the top and bottom base plates The neutral position holding mechanism for holding the second base plate that is configured to the neutral position so as to provided,
The third base plate is connected slidably in the Y direction with respect to the second base plate via a linear guide, similarly slidably connected to said second base plate to the X direction, the neutral position of the third base plate The respective slide blocks that are pulled back to each other are connected by tension coil springs to return the neutral position to the neutral position, and both the slide blocks that hold the third base plate at the center position are pulled inward to each locking member. A compliance module is provided with a neutral position holding mechanism configured to be engaged with ends of upper and lower base plates, and the finger module is mounted on a fourth base plate connected to the third base plate . The fourth base plate is connected to the third base plate so as to be rotatable in the θ direction via a central bearing portion, and the neutral position return mechanism provided between the third base plate and the fourth base plate includes the bearing Two pairs of tension coil springs horizontally facing each other are arranged, and one adjacent end of each coil spring is locked to the lower surface of the third base plate and the other other end is adjacent to the upper surface of the fourth base plate. As a neutral position holding mechanism that is configured to be locked and further configured to be fixedly provided with a pair of magnets having an adsorption surface opposed to the third and fourth base plates, the fourth base plate is held at the center position. When the base plate is in the neutral position, either the third or fourth base plate is provided with a recess and the other base plate has the recess. Compliance Module according to claim 1, characterized in that a movable sphere engaged.

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