Patent Description:
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 <CIT>). 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. Clamp surfaces of gripping claws disclosed in <CIT> are slightly inclined with respect to the vertical surface when no component is held. The gripping claws are elastically deformed when a component is gripped, so that the clamp surfaces become substantially vertical, and lower surfaces of protrusions provided at an angle of slightly more than <NUM> degrees with respect to the clamp surfaces push the upper surface of the component.

In <CIT> 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.

The present disclosure employs a gripping mechanism as defined in the appended claims in order to achieve the main object described above.

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. Furthermore, the abutment portion is embedded in the gripping surface when a component is gripped, so that it is possible to grip the component in any area of the gripping surface, regardless of the strip.

Next, embodiments of the present disclosure will be described with reference to the drawings. <FIG> is a configuration diagram illustrating a schematic configuration of work system <NUM>. <FIG> is a block diagram illustrating an electrical connection relationship of work system <NUM>. In <FIG>, 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 system <NUM> is configured as a system that performs a predetermined work by gripping various components such as mechanical components and electronic components by the operation of robot <NUM> fixed to work table <NUM>. An example of the predetermined work includes mounting work in which a component is mounted on board S.

Board conveyance device <NUM> that conveys board S and feeders <NUM> and <NUM> such as tape feeders that supply components are disposed on work table <NUM>. Board conveyance device <NUM> has 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. Feeder <NUM> feeds a tape, in which multiple components are accommodated at predetermined intervals, rearward (Y-axis direction) to supply the components. Further, feeder <NUM> feeds 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 feeder <NUM>. 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.

Robot <NUM> includes, for example, vertical articulated robot arm <NUM>, component chuck device <NUM> as an end effector detachably attached to a tip link of robot arm <NUM>, and camera <NUM>. Robot arm <NUM> is 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 device <NUM> grips a component by a pair of openable and closable gripping claws <NUM> (refer to <FIG>). Camera <NUM> captures an image for recognizing the position and the posture of the component supplied from feeders <NUM> and <NUM>, or captures an image for recognizing the position of board S conveyed by board conveyance device <NUM>. Although an example is given of a vertical articulated robot as robot <NUM>, a horizontal articulated robot, an XY robot, or the like may be used.

As illustrated in <FIG>, control device <NUM> is configured as a microprocessor that is made up mainly of CPU 28a, and includes, in addition to CPU 28a, ROM 28b that stores various control programs, RAM 28c used as a work area, HDD 28d that stores various data, an input and output port (not illustrated), and the like. Detection signals from sensors (not illustrated) provided in board conveyance device <NUM>, feeders <NUM> and <NUM>, and robot <NUM>, images captured by camera <NUM>, and the like are input to control device <NUM>. Control device <NUM> outputs control signals to board conveyance device <NUM>, feeders <NUM> and <NUM>, robot <NUM> (robot arm <NUM> and component chuck device <NUM>), camera <NUM>, and the like.

Hereinafter, the configuration of component chuck device <NUM> will be described. <FIG> is a perspective view of component chuck device <NUM>. <FIG> is a front view of gripping mechanism <NUM>. <FIG> is a side view of gripping mechanism <NUM>. <FIG> is a front view of gripping claw <NUM> integrated with strip <NUM>. <FIG> is an exploded perspective view of gripping claw <NUM> and strip <NUM>.

Component chuck device <NUM> includes main body portion <NUM> and gripping mechanism <NUM> that grips a component by gripping claws <NUM>. In main body portion <NUM>, fixed portion <NUM> to be fixed to the tip link of robot arm <NUM> by a bolt or the like is provided in an upper part, and support portion <NUM> that supports gripping mechanism <NUM> is provided in a lower part. Main body portion <NUM> accommodates a signal line that transmits a drive signal to an actuator of opening and closing device <NUM> of gripping mechanism <NUM>, a supply line that supplies air or electric power to an actuator, and the like.

Gripping mechanism <NUM> includes opening and closing device <NUM>, a pair of gripping claws <NUM>, a pair of strips <NUM> respectively supported by each of gripping claws <NUM>, and two springs <NUM> respectively biasing each of strips <NUM>. Opening and closing device <NUM> slides a pair of sliders <NUM> to 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 device <NUM>, the position of slider <NUM> is detectable by a position sensor such as an encoder. Gripping claw <NUM> is attached to each of the pair of sliders <NUM>. Opening and closing device <NUM> moves the pair of gripping claws <NUM> in the closing direction (inward) to come close to each other or move the pair of gripping claws <NUM> in the opening direction (outward) to space apart from each other by driving the actuator, thereby opening and closing the pair of gripping claws <NUM>.

Gripping claw <NUM> is provided to extend downward from flat plate-shaped attachment portion <NUM> attached to slider <NUM>, 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 surface 45a that grips a component is formed to be a continuous plane from the upper end side to the lower end side. Further, gripping claw <NUM> is formed in a bifurcated shape to form groove portion <NUM> extending linearly in the up-down direction on the side opposite to gripping surface 45a. Groove portion <NUM> is formed to extend from the upper end side to the lower end side in the center of gripping claw <NUM> in the width direction (left-right direction in <FIG>). Groove portion <NUM> is formed to have a width slightly larger than the thickness of strip <NUM> to be able to accommodate a part of strip <NUM>. In gripping claw <NUM>, support holes 49a for supporting strip <NUM> are formed in side walls <NUM> on both sides of groove portion <NUM>. In groove portion <NUM>, bottom surface 48a of the groove is formed substantially in the center in the up-down direction, and through holes 48b and 48c which penetrate to gripping surface 45a are formed on the upper side and the lower side of bottom surface 48a, respectively.

Strip <NUM> is an inverted L-shaped member in a front view, and is formed such that first extending portion <NUM> extending downward and second extending portion <NUM> extending in a horizontal direction are orthogonal to each other. Further, in strip <NUM>, support shaft <NUM> is attached to shaft hole 50a formed in the bent portion of the inverted L shape, and abutment portion <NUM>, which extends from the lower end side of first extending portion <NUM> in the direction opposite to second extending portion <NUM> to be shorter than second extending portion <NUM> and is configured to abut against the upper surface of a component, is provided.

Strip <NUM> is inserted into groove portion <NUM> of gripping claw <NUM> such that sliding ring <NUM> is sandwiched between strip <NUM> and side wall <NUM>. Then, support shaft <NUM> is inserted in a state where support hole 49a, shaft hole 50a, and the center hole of sliding ring <NUM> communicate with each other, and thereby pivotally supporting strip <NUM> by gripping claw <NUM>. That is, strip <NUM> of the present embodiment is supported by gripping claw <NUM> to be swingable (rotatable) around support shaft <NUM>.

Spring <NUM> is a coil spring and is attached to protruding portion 53a formed at an extending end of second extending portion <NUM> of strip <NUM>. Recessed portion 46a (refer to <FIG>) into which spring <NUM> can be fitted is formed in the lower surface of attachment portion <NUM> of gripping claw <NUM>. Spring <NUM> biases the extending end of second extending portion <NUM> of strip <NUM> downward using the bottom surface of recessed portion 46a as a spring receiver.

In the present embodiment, a part of strip <NUM> (first extending portion <NUM>) is accommodated in groove portion <NUM> in a state where gripping claw <NUM> supports strip <NUM>. Further, second extending portion <NUM> extends in the opening direction with respect to support shaft <NUM>, and the extending end of second extending portion <NUM> is biased downward due to spring <NUM>. Therefore, strip <NUM> swings in a rotation direction in which second extending portion <NUM> is to be lowered around support shaft <NUM> as a fulcrum, that is, in a direction in which abutment portion <NUM> protrudes from gripping surface 45a. Therefore, abutment portion <NUM> of strip <NUM> is inserted through hole 48c on the lower side of groove portion <NUM> and protrudes in the closing direction with respect to gripping surface 45a. However, since bottom surface 48a of groove portion <NUM> of gripping claw <NUM> abuts against strip <NUM> from the side to support side surface 52a of first extending portion <NUM>, the swing of strip <NUM> in the direction in which abutment portion <NUM> protrudes from gripping surface 45a is restricted. Therefore, strip <NUM> remains stationary in the state illustrated in <FIG>. Strip <NUM> is configured such that the lower surface of abutment portion <NUM> is horizontal in a stationary state. In the present embodiment, gripping claw <NUM> and abutment portion <NUM> are configured such that abutment portion <NUM> protrudes in the closing direction above the lower end of gripping surface 45a.

Hereinafter, the operation of component chuck device <NUM> will be described. Here, an example is given of lead component P having lead L as a grip target component.

<FIG> is a view illustrating a state of gripping mechanism <NUM> when gripping claws <NUM> are in a closed state. As illustrated in <FIG>, in a closed state, gripping surfaces 45a of a pair of gripping claws <NUM> abut against each other. In addition, in strips <NUM> respectively supported by each of gripping claws <NUM>, opposing abutment portions <NUM> abut against each other and a force in an opening direction (outward) is exerted on each other. Therefore, each strip <NUM> swings around support shaft <NUM> such that abutment portion <NUM> moves in the opening direction, resisting the biasing force of spring <NUM>, and abutment portion <NUM> is accommodated and embedded along the opening direction with respect to gripping surface 45a. As described above, even when abutment portion <NUM> can protrude from gripping surface 45a, since abutment portion <NUM> does not protrude from gripping surface 45a when gripping claws <NUM> are in the closed state, gripping surfaces 45a can abut against each other to ensure the closed state. Therefore, control device <NUM> can detect that gripping claws <NUM> do not grip a component by detecting the positions of sliders <NUM> in the closed state with the position sensor. When strip <NUM> swings as illustrated in <FIG>, through hole 48b on the upper side of groove portion <NUM> functions as a relief hole of the bent portion of strip <NUM>.

<FIG> is a view illustrating a state where gripping mechanism <NUM> grips lead component P. As illustrated in <FIG>, gripping mechanism <NUM> (opening and closing device <NUM>) grips body B of lead component P in an open state where a pair of gripping claws <NUM> are 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 portion <NUM> when gripping claws <NUM> are in the open state, abutment portion <NUM> of strip <NUM> is in a state of protruding in the closing direction with respect to gripping surface 45a. Gripping mechanism <NUM> grips body B of lead component P in an area of gripping surface 45a below abutment portion <NUM> in gripping claw <NUM>.

<FIG> is a view illustrating a state where gripping mechanism <NUM> pushes in lead component P. Here, control device <NUM> moves gripping mechanism <NUM> (component chuck device <NUM>) such that lead L of lead component P is positioned above a lead hole (not illustrated) formed in board S, and then causes robot arm <NUM> to move gripping mechanism <NUM> downward. As gripping mechanism <NUM> moves downward, the upper surface of lead component P (body B) can be pushed in by abutment portion <NUM> of strip <NUM> to push lead L in the lead hole.

Here, as described above, since the swing of strip <NUM> is restricted by abutting against bottom surface 48a of groove portion <NUM>, even when receiving an upward reaction force when lead component P is pushed in, abutment portion <NUM> does not move upward (in the closing direction), and the position in the up-down direction is maintained. Therefore, gripping mechanism <NUM> can securely push in lead component P. In addition, as illustrated in <FIG>, since gripping mechanism <NUM> grips body B of lead component P in an area of gripping surface 45a below abutment portion <NUM>, the push-in operation can be started without changing the gripping of lead component P. Since abutment portion <NUM> of strip <NUM> can abut against and push in the upper surface of lead component P (body B), regardless of the size of lead component P, versatility of strip <NUM> is high.

<FIG> is a view illustrating a state where gripping mechanism <NUM> grips component P1 without lead L. As illustrated in <FIG>, by abutting abutment portion <NUM> of strip <NUM> against the side surface of component P1, a force in the opening direction is exerted on abutment portion <NUM>. Therefore, strip <NUM> swings in a direction in which abutment portion <NUM> is accommodated along the opening direction with respect to gripping surface 45a, resisting the biasing force of spring <NUM>, and abutment portion <NUM> is embedded in gripping surface 45a. In this manner, by embedding abutment portion <NUM> in gripping surface 45a, it is possible to grip component P1 in any area of gripping surface 45a, regardless of strip <NUM> (abutment portion <NUM>). That is, even when gripping claw <NUM> and strip <NUM> are 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 claw <NUM> corresponds to a gripping claw, opening and closing device <NUM> corresponds to an opening and closing device, strip <NUM> corresponds to a strip, and gripping mechanism <NUM> corresponds to a gripping mechanism. Spring <NUM> corresponds to a biasing member. Groove portion <NUM> corresponds to a groove portion, bottom surface 48a corresponds to a bottom surface, and through hole 48c corresponds to a through hole.

As described above, in gripping mechanism <NUM> of the present disclosure, strip <NUM> is configured to move integrally with gripping claw <NUM>, and is configured such that abutment portion <NUM> protrudes in the closing direction with respect to gripping surface 45a in an open state of gripping claws <NUM>. Accordingly, even when gripping claws <NUM> move to any positions according to the size of the component to be gripped, abutment portion <NUM> can be abutted against the upper surface of the component to push in the component. Therefore, the versatility of strip <NUM> can be enhanced, and the exchange operation of strip <NUM> can be reduced.

In addition, since abutment portion <NUM> of strip <NUM> is embedded in gripping surface 45a when a force in the opening direction is exerted on abutment portion <NUM>, gripping claws <NUM> can be fully closed, so that gripping surfaces 45a abut against each other, or can grip a component at a portion of gripping surface 45a where abutment portion <NUM> protrudes.

In addition, with a simple configuration in which strip <NUM> is pivotally supported by gripping claw <NUM> to be swingable around an axis, abutment portion <NUM> can be made to protrude from or embed in gripping surface 45a.

In addition, since spring <NUM> is provided to bias strip <NUM> such that strip <NUM> swings in a direction in which abutment portion <NUM> protrudes from gripping surface 45a, it is possible to prevent abutment portion <NUM> from being unable to protrude due to an operation failure or the like.

In gripping claw <NUM>, groove portion <NUM> is formed on the opposite side from gripping surface 45a, and strip <NUM> is pivotally supported on side wall <NUM> of groove portion <NUM> to be swingable around an axis. Groove portion <NUM> includes bottom surface 48a which abuts against strip <NUM> from the side, and is formed with through hole 48c which penetrates to gripping surface 45a such that abutment portion <NUM> is inserted. Therefore, it is possible to provide a compact configuration in which strip <NUM> is accommodated in the width direction of gripping claw <NUM>. In addition, even when an upward force is exerted on abutment portion <NUM> when a component is pushed in, since bottom surface 48a of groove portion <NUM> restricts the swing of strip <NUM>, so that the position of abutment portion <NUM> in the up-down direction is maintained, the component can be securely pushed in. In addition, since gripping claws <NUM> grip lead component P in an area of gripping surface 45a below a portion where abutment portion <NUM> protrudes, lead component P can be pushed in by abutment portion <NUM> without 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 scope of the claims appended to the present disclosure.

In the embodiment described above, gripping claw <NUM> is bifurcated to form groove portion <NUM>, and a part (first extending portion <NUM>) of strip <NUM> is accommodated in groove portion <NUM>, thereby accommodating strip <NUM> in the width direction of gripping claw <NUM>, but the embodiment is not limited thereto. For example, strip <NUM> may be configured to be pivotally supported on both outer sides of gripping claw <NUM> in the width direction. When configured in this way, there is no need to form groove portion <NUM> by making gripping claw <NUM> bifurcated. Alternatively, gripping claw <NUM> may be accommodated between two abutment portions <NUM> protruding from both outer sides of gripping claw <NUM> by making strip <NUM> bifurcated.

In the embodiment, through hole 48b functioning as the relief hole is formed in the upper part of groove portion <NUM>, 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, spring <NUM> that biases strip <NUM> is provided, but the present embodiment is not limited thereto, and strip <NUM> may be swung by its own weight without providing spring <NUM>, or may be swung by attaching a weight or the like.

In the embodiment, strip <NUM> is configured to be swingable, but the present embodiment is not limited thereto. For example, strip <NUM> may be a pin member in which abutment portion <NUM> at the tip end of strip <NUM> is biased to protrude in the closing direction from gripping surface 45a by a biasing member such as a spring, and when a force in the opening direction is exerted, abutment portion <NUM> is embedded in gripping surface 45a, resisting the biasing force of the biasing member. That is, strip <NUM> may be configured to be movable in the horizontal direction such that abutment portion <NUM> at the tip end protrudes in the closing direction or is embedded in the opening direction with respect to gripping surface 45a.

In the embodiment, strip <NUM> is supported by gripping claw <NUM>, but the present embodiment is not limited thereto, and strip <NUM> may be supported by attachment portion <NUM> or slider <NUM>.

In the embodiment, an example is given where a pair of gripping claws <NUM> are provided, but the present embodiment is not limited thereto. For example, the present embodiment may be provided with multiple gripping claws <NUM>, such as multiple pairs of gripping claws <NUM>, three or more gripping claws <NUM> arranged alternately, or three or more gripping claws <NUM> arranged radially with respect to the gripping center. Further, the present embodiment is not limited to the one in which strip <NUM> is attached to all of multiple gripping claws <NUM>, and strip <NUM> need not be attached to some of multiple gripping claws <NUM>.

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

Although strip <NUM> of the embodiment is configured to abut against the upper surface of a component regardless of the size of the component and has high versatility, strip <NUM> may be replaced according to the size or shape of the component. For example, strip <NUM> selected from among multiple types of strips <NUM> that differ in the length at which abutment portion <NUM> protrudes from gripping surface 45a and 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.

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

Claim 1:
A gripping mechanism (<NUM>) comprising:
multiple gripping claws (<NUM>) configured to grip a component (P, P1);
an opening and closing device (<NUM>) configured to move the multiple gripping claws (<NUM>) in an opening direction in which the multiple gripping claws (<NUM>) are spaced apart from each other and in a closing direction in which the multiple gripping claws (<NUM>) come close to each other; and
multiple strips (<NUM>) including abutment portions (<NUM>) configured to abut against an upper surface of the component (P, P1),
wherein the strip (<NUM>) is configured to move integrally with the gripping claw (<NUM>), and is configured such that the abutment portion (<NUM>) protrudes in the closing direction with respect to a gripping surface (45a) of the gripping claw (<NUM>) in an open state where the multiple gripping claws (<NUM>) are spaced apart from each other,
characterized in that
the strip (<NUM>) is configured such that the abutment portion (<NUM>) is accommodated along the opening direction with respect to the gripping surface (45a) when a force in the opening direction is exerted on the abutment portion (<NUM>).