GRIPPING MECHANISM

A gripping mechanism includes multiple gripping claws configured to grip a component, an opening and closing device configured to move the multiple gripping claws in an opening direction in which the multiple gripping claws are spaced apart from each other and in a closing direction in which the multiple gripping claws come close to each other, and multiple strips including abutment portions configured to abut against an upper surface of the component. The strip is configured to move integrally with the gripping claw, and is configured such that the abutment portion protrudes in the closing direction with respect to a gripping surface of the gripping claw in an open state where the multiple gripping claws are spaced apart from each other.

TECHNICAL FIELD

The present description discloses a gripping mechanism.

BACKGROUND ART

Conventionally, there has been proposed a gripping mechanism for a component including a pair of gripping claws configured to grip a component, an opening and closing device for opening and closing the pair of gripping claws, and a block-shaped strip that abuts against an upper surface of the component (for example, refer to Patent Literature 1). In this gripping mechanism, it is described that an attaching surface for a strip is provided substantially in the center of the opening and closing device, and a strip according to the size of a component among multiple types of strips is attached on the attaching surface, or an upper surface of the component is abutted against the strip and gripped by the gripping claws, whereby the component can be gripped in a correct posture. Such strip is also used for push-in, when the component having a lead below is pushed in from above and the lead is inserted into the insertion hole of the board.

PATENT LITERATURE

SUMMARY OF THE INVENTION

Technical Problem

In Patent Literature 1 described above, since it is necessary to secure a space for attaching a strip to the opening and closing device, the opening and closing device may be increased in size. In addition, since it is necessary to exchange the strip according to the size of the component, exchange operation may take time and affect the production.

A main object of the present disclosure is to provide a gripping mechanism that does not need to secure a space for attaching a strip in an opening and closing device and can reduce exchange operation by enhancing versatility of the strip.

Solution to Problem

The present disclosure employs the following means in order to achieve the main object described above.

A gripping mechanism of the present disclosure includes: multiple gripping claws configured to grip a component: an opening and closing device configured to move the multiple gripping claws in an opening direction to space apart from each other and in a closing direction to come close to each other; and multiple strips including abutment portions configured to abut against an upper surface of the component, in which the strip is configured to move integrally with the gripping claw, and is configured such that the abutment portion protrudes in the closing direction with respect to a gripping surface of the gripping claw in an open state where the multiple gripping claws are spaced apart from each other.

In the gripping mechanism of the present disclosure, the strip is configured to move integrally with the gripping claw, and is configured such that the abutment portion protrudes in the closing direction with respect to the gripping surface of the gripping claw in the open state where the multiple gripping claws are spaced apart from each other. Accordingly, it is not necessary to secure a space for attaching a strip in the opening and closing device. In addition, even when the gripping claws move to any positions according to the size of the component to be gripped, since the abutment portion protrudes with respect to the gripping surface, the abutment portion of the strip can be abutted against an upper surface of the component regardless of the size of the component. Therefore, the versatility of the strip can be enhanced, and the exchange operation of the strip can be reduced.

DESCRIPTION OF EMBODIMENTS

Next, embodiments of the present disclosure will be described with reference to the drawings.FIG.1is a configuration diagram illustrating a schematic configuration of work system10.FIG.2is a block diagram illustrating an electrical connection relationship of work system10. InFIG.1, a left-right direction is an X-axis direction, a front-rear direction is a Y-axis direction, and an up-down direction is a Z-axis direction.

Work system10is configured as a system that performs a predetermined work by gripping various components such as mechanical components and electronic components by the operation of robot20fixed to work table11. An example of the predetermined work includes mounting work in which a component is mounted on board S.

Board conveyance device12that conveys board S and feeders14and16such as tape feeders that supply components are disposed on work table11. Board conveyance device12has a pair of belt conveyors which are bridged in the left-right direction (X-axis direction) at intervals in the front-rear direction (Y-axis direction), and conveys board S from left to right by the belt conveyor. Feeder14feeds a tape, in which multiple components are accommodated at predetermined intervals, rearward (Y-axis direction) to supply the components. Further, feeder16feeds the tape, to which lead component P is attached, to supply lead component P. Lead component P includes body B and lead L extending downward from body B, and is supplied in an upright posture with body B being on the upper side by feeder16. The feeder is not limited to the tape feeder, and may be a tray feeder that supplies a tray in which multiple components are disposed, a bulk feeder that accommodates multiple components in a scattered state and supplies the components while aligning the components, or the like.

Robot20includes, for example, vertical articulated robot arm22, component chuck device30as an end effector detachably attached to a tip link of robot arm22, and camera24. Robot arm22is provided with a servo motor, an encoder that detects a rotation angle, and the like, which are not illustrated, at each joint. Although details will be described later, component chuck device30grips a component by a pair of openable and closable gripping claws45(refer toFIG.3). Camera24captures an image for recognizing the position and the posture of the component supplied from feeders14and16, or captures an image for recognizing the position of board S conveyed by board conveyance device12. Although an example is given of a vertical articulated robot as robot20, a horizontal articulated robot, an XY robot, or the like may be used.

As illustrated inFIG.2, control device28is configured as a microprocessor that is made up mainly of CPU28a, and includes, in addition to CPU28a, ROM28bthat stores various control programs, RAM28cused as a work area, HDD28dthat stores various data, an input and output port (not illustrated), and the like. Detection signals from sensors (not illustrated) provided in board conveyance device12, feeders14and16, and robot20, images captured by camera24, and the like are input to control device28. Control device28outputs control signals to board conveyance device12, feeders14and16, robot20(robot arm22and component chuck device30), camera24, and the like. Hereinafter, the configuration of component chuck device30will be described.FIG.3is a perspective view of component chuck device30.FIG.4is a front view of gripping mechanism40.FIG.5is a side view of gripping mechanism40.FIG.6is a front view of gripping claw45integrated with strip50.FIG.7is an exploded perspective view of gripping claw45and strip50.

Component chuck device30includes main body portion31and gripping mechanism40that grips a component by gripping claws45. In main body portion31, fixed portion32to be fixed to the tip link of robot arm22by a bolt or the like is provided in an upper part, and support portion34that supports gripping mechanism40is provided in a lower part. Main body portion31accommodates a signal line that transmits a drive signal to an actuator of opening and closing device42of gripping mechanism40, a supply line that supplies air or electric power to an actuator, and the like.

Gripping mechanism40includes opening and closing device42, a pair of gripping claws45, a pair of strips50respectively supported by each of gripping claws45, and two springs55respectively biasing each of strips50. Opening and closing device42slides a pair of sliders44to come close to or space apart from each other by driving an actuator such as an air cylinder or a motor. In opening and closing device42, the position of slider44is detectable by a position sensor such as an encoder. Gripping claw45is attached to each of the pair of sliders44. Opening and closing device42moves the pair of gripping claws45in the closing direction (inward) to come close to each other or move the pair of gripping claws45in the opening direction (outward) to space apart from each other by driving the actuator, thereby opening and closing the pair of gripping claws45.

Gripping claw45is provided to extend downward from flat plate-shaped attachment portion46attached to slider44, and is formed with a smaller width at the lower end side (tip side) than at the upper end side (base end side) in a front view, and gripping surface45athat grips a component is formed to be a continuous plane from the upper end side to the lower end side. Further, gripping claw45is formed in a bifurcated shape to form groove portion48extending linearly in the up-down direction on the side opposite to gripping surface45a. Groove portion48is formed to extend from the upper end side to the lower end side in the center of gripping claw45in the width direction (left-right direction inFIG.5). Groove portion48is formed to have a width slightly larger than the thickness of strip50to be able to accommodate a part of strip50. In gripping claw45, support holes49afor supporting strip50are formed in side walls49on both sides of groove portion48. In groove portion48, bottom surface48aof the groove is formed substantially in the center in the up-down direction, and through holes48band48cwhich penetrate to gripping surface45aare formed on the upper side and the lower side of bottom surface48a, respectively.

Strip50is an inverted L-shaped member in a front view, and is formed such that first extending portion52extending downward and second extending portion53extending in a horizontal direction are orthogonal to each other. Further, in strip50, support shaft51is attached to shaft hole50aformed in the bent portion of the inverted L shape, and abutment portion54, which extends from the lower end side of first extending portion52in the direction opposite to second extending portion53to be shorter than second extending portion53and is configured to abut against the upper surface of a component, is provided.

Strip50is inserted into groove portion48of gripping claw45such that sliding ring57is sandwiched between strip50and side wall49. Then, support shaft51is inserted in a state where support hole49a, shaft hole50a, and the center hole of sliding ring57communicate with each other, and thereby pivotally supporting strip50by gripping claw45. That is, strip50of the present embodiment is supported by gripping claw45to be swingable (rotatable) around support shaft51.

Spring55is a coil spring and is attached to protruding portion53aformed at an extending end of second extending portion53of strip50. Recessed portion46a(refer toFIG.6) into which spring55can be fitted is formed in the lower surface of attachment portion46of gripping claw45. Spring55biases the extending end of second extending portion53of strip50downward using the bottom surface of recessed portion46aas a spring receiver.

In the present embodiment, a part of strip50(first extending portion52) is accommodated in groove portion48in a state where gripping claw45supports strip50. Further, second extending portion53extends in the opening direction with respect to support shaft51, and the extending end of second extending portion53is biased downward due to spring55. Therefore, strip50swings in a rotation direction in which second extending portion53is to be lowered around support shaft51as a fulcrum, that is, in a direction in which abutment portion54protrudes from gripping surface45a. Therefore, abutment portion54of strip50is inserted through hole48con the lower side of groove portion48and protrudes in the closing direction with respect to gripping surface45a. However, since bottom surface48aof groove portion48of gripping claw45abuts against strip50from the side to support side surface52aof first extending portion52, the swing of strip50in the direction in which abutment portion54protrudes from gripping surface45ais restricted. Therefore, strip50remains stationary in the state illustrated inFIG.6. Strip50is configured such that the lower surface of abutment portion54is horizontal in a stationary state. In the present embodiment, gripping claw45and abutment portion54are configured such that abutment portion54protrudes in the closing direction above the lower end of gripping surface45a.

Hereinafter, the operation of component chuck device30will be described. Here, an example is given of lead component P having lead L as a grip target component.

FIG.8is a view illustrating a state of gripping mechanism40when gripping claws45are in a closed state. As illustrated inFIG.8, in a closed state, gripping surfaces45aof a pair of gripping claws45abut against each other. In addition, in strips50respectively supported by each of gripping claws45, opposing abutment portions54abut against each other and a force in an opening direction (outward) is exerted on each other. Therefore, each strip50swings around support shaft51such that abutment portion54moves in the opening direction, resisting the biasing force of spring55, and abutment portion54is accommodated and embedded along the opening direction with respect to gripping surface45a. As described above, even when abutment portion54can protrude from gripping surface45a, since abutment portion54does not protrude from gripping surface45awhen gripping claws45are in the closed state, gripping surfaces45acan abut against each other to ensure the closed state. Therefore, control device28can detect that gripping claws45do not grip a component by detecting the positions of sliders44in the closed state with the position sensor. When strip50swings as illustrated inFIG.8, through hole48bon the upper side of groove portion48functions as a relief hole of the bent portion of strip50.

FIG.9is a view illustrating a state where gripping mechanism40grips lead component P. As illustrated inFIG.9, gripping mechanism40(opening and closing device42) grips body B of lead component P in an open state where a pair of gripping claws45are moved to a position according to the size of lead component P (body B). Since a force in the opening direction is not exerted on abutment portion54when gripping claws45are in the open state, abutment portion54of strip50is in a state of protruding in the closing direction with respect to gripping surface45a. Gripping mechanism40grips body B of lead component P in an area of gripping surface45abelow abutment portion54in gripping claw45.

FIG.10is a view illustrating a state where gripping mechanism40pushes in lead component P. Here, control device28moves gripping mechanism40(component chuck device30) such that lead L of lead component P is positioned above a lead hole (not illustrated) formed in board S, and then causes robot arm22to move gripping mechanism40downward. As gripping mechanism40moves downward, the upper surface of lead component P (body B) can be pushed in by abutment portion54of strip50to push lead L in the lead hole.

Here, as described above, since the swing of strip50is restricted by abutting against bottom surface48aof groove portion48, even when receiving an upward reaction force when lead component P is pushed in, abutment portion54does not move upward (in the closing direction), and the position in the up-down direction is maintained. Therefore, gripping mechanism40can securely push in lead component P. In addition, as illustrated inFIG.9, since gripping mechanism40grips body B of lead component P in an area of gripping surface45abelow abutment portion54, the push-in operation can be started without changing the gripping of lead component P. Since abutment portion54of strip50can abut against and push in the upper surface of lead component P (body B), regardless of the size of lead component P, versatility of strip50is high.

FIG.11is a view illustrating a state where gripping mechanism40grips component P1without lead L. As illustrated inFIG.11, by abutting abutment portion54of strip50against the side surface of component P1, a force in the opening direction is exerted on abutment portion54. Therefore, strip50swings in a direction in which abutment portion54is accommodated along the opening direction with respect to gripping surface45a, resisting the biasing force of spring55, and abutment portion54is embedded in gripping surface45a. In this manner, by embedding abutment portion54in gripping surface45a, it is possible to grip component P1in any area of gripping surface45a, regardless of strip50(abutment portion54). That is, even when gripping claw45and strip50are integrally configured, it is possible to prevent restrictions from occurring in gripping a component.

Here, a correspondence relationship between the elements of the present embodiment and the elements of the present disclosure will be clarified. In the present embodiment, gripping claw45corresponds to a gripping claw, opening and closing device42corresponds to an opening and closing device, strip50corresponds to a strip, and gripping mechanism40corresponds to a gripping mechanism. Spring55corresponds to a biasing member. Groove portion48corresponds to a groove portion, bottom surface48acorresponds to a bottom surface, and through hole48ccorresponds to a through hole.

As described above, in gripping mechanism40of the present disclosure, strip50is configured to move integrally with gripping claw45, and is configured such that abutment portion54protrudes in the closing direction with respect to gripping surface45ain an open state of gripping claws45. Accordingly, even when gripping claws45move to any positions according to the size of the component to be gripped, abutment portion54can be abutted against the upper surface of the component to push in the component. Therefore, the versatility of strip50can be enhanced, and the exchange operation of strip50can be reduced.

In addition, since abutment portion54of strip50is embedded in gripping surface45awhen a force in the opening direction is exerted on abutment portion54, gripping claws45can be fully closed, so that gripping surfaces45aabut against each other, or can grip a component at a portion of gripping surface45awhere abutment portion54protrudes.

In addition, with a simple configuration in which strip50is pivotally supported by gripping claw45to be swingable around an axis, abutment portion54can be made to protrude from or embed in gripping surface45a.

In addition, since spring55is provided to bias strip50such that strip50swings in a direction in which abutment portion54protrudes from gripping surface45a, it is possible to prevent abutment portion54from being unable to protrude due to an operation failure or the like.

In gripping claw45, groove portion48is formed on the opposite side from gripping surface45a, and strip50is pivotally supported on side wall49of groove portion48to be swingable around an axis. Groove portion48includes bottom surface48awhich abuts against strip50from the side, and is formed with through hole48cwhich penetrates to gripping surface45asuch that abutment portion54is inserted. Therefore, it is possible to provide a compact configuration in which strip50is accommodated in the width direction of gripping claw45. In addition, even when an upward force is exerted on abutment portion54when a component is pushed in, since bottom surface48aof groove portion48restricts the swing of strip50, so that the position of abutment portion54in the up-down direction is maintained, the component can be securely pushed in. In addition, since gripping claws45grip lead component P in an area of gripping surface45abelow a portion where abutment portion54protrudes, lead component P can be pushed in by abutment portion54without changing the grip.

Needless to say, the present disclosure is not limited to the embodiment that has been described heretofore in any way, and hence can be carried out in various manners without departing from the technical scope of the present disclosure.

In the embodiment described above, gripping claw45is bifurcated to form groove portion48, and a part (first extending portion52) of strip50is accommodated in groove portion48, thereby accommodating strip50in the width direction of gripping claw45, but the embodiment is not limited thereto. For example, strip50may be configured to be pivotally supported on both outer sides of gripping claw45in the width direction. When configured in this way, there is no need to form groove portion48by making gripping claw45bifurcated. Alternatively, gripping claw45may be accommodated between two abutment portions54protruding from both outer sides of gripping claw45by making strip50bifurcated.

In the embodiment, through hole48bfunctioning as the relief hole is formed in the upper part of groove portion48, but through hole need not be formed when the depth of the groove is a depth sufficient to function as the relief hole.

In the embodiment, spring55that biases strip50is provided, but the present embodiment is not limited thereto, and strip50may be swung by its own weight without providing spring55, or may be swung by attaching a weight or the like.

In the embodiment, strip50is configured to be swingable, but the present embodiment is not limited thereto. For example, strip50may be a pin member in which abutment portion54at the tip end of strip50is biased to protrude in the closing direction from gripping surface45aby a biasing member such as a spring, and when a force in the opening direction is exerted, abutment portion54is embedded in gripping surface45a, resisting the biasing force of the biasing member. That is, strip50may be configured to be movable in the horizontal direction such that abutment portion54at the tip end protrudes in the closing direction or is embedded in the opening direction with respect to gripping surface45a.

In the embodiment, strip50is supported by gripping claw45, but the present embodiment is not limited thereto, and strip50may be supported by attachment portion46or slider44.

In the embodiment, an example is given where a pair of gripping claws45are provided, but the present embodiment is not limited thereto. For example, the present embodiment may be provided with multiple gripping claws45, such as multiple pairs of gripping claws45, three or more gripping claws45arranged alternately, or three or more gripping claws45arranged radially with respect to the gripping center. Further, the present embodiment is not limited to the one in which strip50is attached to all of multiple gripping claws45, and strip50need not be attached to some of multiple gripping claws45.

In the embodiment, an example is given where lead component P is pushed in by strip50, but the present embodiment is not limited thereto, and strip50(abutment portion54) may abut against the upper surface of a component in order to adjust the height position when the component is gripped.

Although strip50of the embodiment is configured to abut against the upper surface of a component regardless of the size of the component and has high versatility, strip50may be replaced according to the size or shape of the component. For example, strip50selected from among multiple types of strips50that differ in the length at which abutment portion54protrudes from gripping surface45aand the position of protruding portion in the up-down direction may be attached.

Here, the gripping mechanism of the present disclosure may be configured as follows. For example, in the gripping mechanism of the present disclosure, the strip may be configured such that the abutment portion is accommodated along the opening direction with respect to the gripping surface when a force in the opening direction is exerted on the abutment portion. In this way, even when the abutment portion of the strip is configured to protrude with respect to the gripping surface, the gripping claws can be fully closed, so that the gripping surfaces abut against each other, or can grip a component at a portion of the gripping surface where the abutment portion protrudes.

In the gripping mechanism of the present disclosure, the strip may be pivotally supported by the gripping claw to be swingable around an axis, and may be configured to swing in a direction in which the abutment portion protrudes in the closing direction with respect to the gripping surface when the multiple gripping claws are in the open state and a force in the opening direction is not exerted on the abutment portion, and swing in a direction in which the abutment portion is accommodated along the opening direction with respect to the gripping surface when the multiple gripping claws come close to each other to be in a closed state and a force in the opening direction is exerted on the abutment portion. In this way, the abutment portion of the strip can be made to protrude from or accommodate in the gripping surface with a simple configuration.

The gripping mechanism of the present disclosure may further include a biasing member configured to bias the strip such that the strip swings in a direction in which the abutment portion protrudes in the closing direction with respect to the gripping surface. In this way, it is possible to prevent the abutment portion from being unable to protrude due to an operation failure or the like.

In the gripping mechanism of the present disclosure, in the gripping claw, a groove portion extending in an up-down direction to accommodate at least a part of the strip may be formed in a center in a width direction on a side opposite to the gripping surface, the strip may be pivotally supported on a side wall of the groove portion such that an upper end side is swingable around an axis, and includes the abutment portion that is provided on a lower end side to extend in the closing direction, and the groove portion may include a bottom surface which abuts against the strip from a side and may be formed with a through hole which penetrates to the gripping surface such that the abutment portion is inserted into a part of the bottom surface. In this way, a compact configuration in which the strip is accommodated in the width direction of the gripping claw can be obtained. In addition, even when an upward force is exerted on the abutment portion when a component is pushed in, since the bottom surface of the groove portion restricts the swing by abutting against the strip from the side, so that the position of the abutment portion is maintained, the component can be securely pushed in.

In the gripping mechanism of the present disclosure, the abutment portion of the strip may protrude in the closing direction above a lower end of the gripping surface, and the gripping claw may be configured to grip a component in an area of the gripping surface below the abutment portion. In this way, since the abutment portion protrudes above the component gripped by the gripping surface, the gripped component can be pushed in without changing the grip.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable to a technical field of devices for gripping a component.

REFERENCE SIGNS LIST