Patent Description:
Recently, industrial robots are used in production lines for various industrial products. A robot is structured such that end effector such as a hand is attached to the end of an arm and can grip a component or a work by means of the end effector. Generally, the operation of a robot is controlled according to position control. When the position of an object gripped is displaced from a preprogrammed target position, therefore, the robot might not be able to grip the object properly. It is therefore desired to finely adjust the position of an object so that the position of the object agrees with the target position. In this background, patent literature <NUM> discloses a work positioning apparatus capable of finely adjusting the horizontal position of a work. Patent literature <NUM> discloses a positioning apparatus reflecting the preamble of present claim <NUM>. Patent literature <NUM> discloses a device for aligning a table with respect to a base body with a plurality of adjustment elements which act on the periphery of the tiltable table.

The above-mentioned related-art positioning apparatus is structured such that a table part not carrying a work is returned to the centering position by a volute spring. Therefore, the number of components in the related-art positioning apparatus is large, and the structure thereof is complicated. A larger number of components could lead to a larger size of the positioning apparatus. The manufacturing cost of the positioning apparatus is also increased accordingly. Further, an attempt to reduce the size of the positioning apparatus requires reducing the size of components and could lead to reduced durability of the components and, ultimately, reduced durability of the positioning apparatus.

An embodiment of the present disclosure relates to a positioning apparatus. The positioning apparatus includes: an upper unit that includes a spherical body, a retainer part that retains the spherical body, and an upper plate part provided on the retainer part and adapted to carry a carried object; a lower unit that includes a lower plate part on which the upper unit is mounted and a guide part that marks a region of movement of the upper unit on the lower plate part; and a tilting structure that tilts the region of movement relative to a horizontal plane and guides the upper unit, on which the carried object is not mounted, toward a reference position located on a lower side of a tilt, the reference position being a position where the carried object (<NUM>) is to be mounted on the upper plate part (<NUM>); the reference position being a position where the upper unit (<NUM>) butts against the guide part (<NUM>); the upper unit (<NUM>) on which the carried object (<NUM>) is not mounted can be returned to the reference position automatically by utilizing gravitational force.

Optional combinations of the aforementioned constituting elements, and implementations of the present disclosure in the form of methods, devices, systems, etc. may also be practiced as additional modes of the present disclosure.

According to the present disclosure, the structure of a positioning apparatus is simplified.

Hereinafter, the present disclosure will be described based on preferred embodiments with reference to the accompanying drawings. The embodiments are not intended to limit the scope of the present disclosure but exemplify the present disclosure. Not all of the features and the combinations thereof described in the embodiments are necessarily essential to the present disclosure. Identical or like constituting elements, members, processes shown in the drawings are represented by identical symbols and a duplicate description will be omitted as appropriate. The scales and shapes shown in the figures are defined for convenience's sake to make the explanation easy and shall not be interpreted limitatively unless otherwise specified. Terms like "first", "second", etc. used in the specification and claims do not indicate an order or importance by any means unless specified otherwise and are used to distinguish a certain feature from the others. Those of the members that are not important in describing the embodiment are omitted from the drawings.

<FIG> is a perspective view of a carried object mounted on the positioning apparatus according to embodiment <NUM>. <FIG> is a perspective view of a rack restriction apparatus provided with a positioning apparatus. <FIG> and <FIG> are perspective views showing how the carried object is mounted on the rack restriction apparatus. In <FIG> and <FIG>, illustration of a housing frame body <NUM> is omitted. The positioning apparatus <NUM> according to this embodiment is used to finely adjust the position of a carried object <NUM> mounted on a rack restriction apparatus <NUM>.

The carried object <NUM> includes, by way of one example, an electrode hoop <NUM> and an electrode rack <NUM> for supporting the electrode hoop <NUM>. The electrode hoop <NUM> is produced by winding an electrode plate of a secondary battery around a bobbin, and has a through hole <NUM> in the center. The electrode rack <NUM> includes a rack body <NUM>, a support shaft <NUM> projecting from the rack body <NUM> substantially in the horizontal direction, and a rack leg <NUM> projecting downward from the rack body <NUM>. The electrode rack <NUM> according to this embodiment includes four rack legs <NUM>. The electrode hoop <NUM> is supported by the electrode rack <NUM> such that the support shaft <NUM> is inserted in the through hole <NUM>. In this embodiment, two electrode hoops <NUM> are supported by one electrode rack <NUM>. The weight of the carried object <NUM> is, for example, <NUM> to <NUM>. The carried object <NUM> is not limited to the electrode hoop <NUM> and the electrode rack <NUM>.

The rack restriction apparatus <NUM> includes the positioning apparatus <NUM> and the housing frame body <NUM>. The positioning apparatus <NUM> includes a base plate <NUM> and a movable part <NUM>. The carried object <NUM> is mounted on the base plate <NUM>. The housing frame body <NUM> is fixed to the upper surface of the base plate <NUM>. The housing frame body <NUM> surrounds the carried object <NUM> while the carried object <NUM> is placed on the base plate <NUM>.

The housing frame body <NUM> includes an entrance frame <NUM> and an exit frame <NUM> opposite to each other. The carried object <NUM> is inserted from the entrance frame <NUM> and mounted on the base plate <NUM>. The end of the support shaft <NUM> faces the exit frame <NUM> while the carried object <NUM> is placed on the base plate <NUM>. An arm (not shown) of a robot advances from the exit frame <NUM> to a position above the base plate <NUM>, grips the electrode hoop <NUM> of the carried object <NUM>, and dismantles the electrode hoop <NUM> from the support shaft <NUM>. The housing frame body <NUM> includes a sensor <NUM> for sensing that the carried object <NUM> is mounted on the base plate <NUM>.

The movable part <NUM> is a floating unit that supports the carried object <NUM> and is fixed to the upper surface of the base plate <NUM>. The movable part <NUM> includes an upper unit <NUM> and a lower unit <NUM>. The positioning apparatus <NUM> of this embodiment includes four movable parts <NUM> to correspond to the four rack legs <NUM>. The lower unit <NUM> of each movable part <NUM> is supported by the base plate <NUM>. The upper unit <NUM> is mounted on the lower unit <NUM>. The rack leg <NUM> of the electrode rack <NUM> is mounted on each upper unit <NUM>. Displacement of each upper unit <NUM> relative to each lower unit <NUM> finely adjusts the position of the carried object <NUM>.

The positioning apparatus <NUM> includes a drawing mechanism <NUM> and a pair of lateral position adjustment mechanisms <NUM>. The drawing mechanism <NUM> is provided on the side of the base plate <NUM> opposite to the entrance frame <NUM>, i.e., toward the exit frame <NUM>. The drawing mechanism <NUM> includes, by way of one example, an air cylinder <NUM> and a catching pawl <NUM> attached to the end of the piston provided in the air cylinder <NUM>. The air cylinder <NUM> can extend or contract in the direction of advancement of the carried object <NUM>, i.e., in the direction in which the entrance frame <NUM> and the exit frame <NUM> are aligned. The drawing mechanism <NUM> can finely adjust the position of the carried object <NUM> in the direction of advancement of the carried object <NUM> by catching the catching pawl <NUM> in the rack body <NUM> of the carried object <NUM> mounted on the upper unit <NUM> to extend or contract the air cylinder <NUM>.

The pair of lateral position adjustment mechanisms <NUM> are aligned in a direction (hereinafter, referred to as lateral direction for convenience) orthogonal to the direction of advancement of the carried object <NUM>. Each lateral position adjustment mechanism <NUM> includes, by way of one example, a pair of air cylinders <NUM> and an extrusion rod <NUM> attached to the end of the piston provided in each air cylinder <NUM>. The air cylinder <NUM> can extend or contract in the lateral direction. The pair of lateral position adjustment mechanisms <NUM> can finely adjust the position of the carried object <NUM> in the lateral direction by thrusting the respective extrusion rods <NUM> against the rack body <NUM> of the carried object <NUM> mounted on the upper unit <NUM> so as to extend or contract each air cylinder <NUM>. For example, the extrusion force of one of the lateral position mechanisms <NUM> is configured to be weaker than that of the other lateral position mechanism <NUM>. This ensures that the lateral position of the carried object <NUM> is adjusted in a stable manner.

The base plate <NUM> includes a leg part <NUM> that projects from the lower surface. The rack restriction apparatus <NUM> is supported on the floor face by the leg part <NUM>. In this embodiment, two leg parts <NUM> are provided at the edges of the base plate <NUM> toward the entrance frame <NUM> so as to be aligned in the lateral direction, and three leg parts <NUM> are provided at the edges toward the exit frame <NUM> so as to be aligned in the lateral direction. Each leg part <NUM> is formed by an adjuster bolt, etc. and can extend or contract independently. Therefore, leveling adjustment of the electrode rack <NUM> is possible by adjusting the length of each leg part <NUM>.

The positioning apparatus <NUM> has a tilting structure <NUM>. The tilting structure <NUM> of this embodiment is formed by the leg part <NUM>. The tilting structure <NUM> is a mechanism to tilt the movable part <NUM> relative to the horizontal plane. The movable part <NUM> and the tilting structure <NUM> will be described in detail.

<FIG> is a perspective view of the movable part <NUM> provided in the positioning apparatus <NUM>. <FIG> is a cross-sectional view of the positioning apparatus <NUM>. As described above, the movable part <NUM> includes the upper unit <NUM> and the lower unit <NUM>. The upper unit <NUM> includes a spherical body <NUM>, a retainer part <NUM>, and an upper plate part <NUM>.

The spherical body <NUM> is a high-rigidity ball formed by, for example, a steel ball. The upper unit <NUM> of this embodiment includes a plurality of spherical bodies <NUM>. The plurality of spherical bodies <NUM> are arranged at predetermined intervals in a plan view. The retainer part <NUM> is a plate body extending in parallel to the base plate <NUM> and includes a plurality of through holes <NUM> connecting two opposite principal surfaces. The spherical body <NUM> is housed in each through hole <NUM>. This ensures that the plurality of spherical bodies <NUM> are retained by the retainer part <NUM>.

The upper plate part <NUM> is provided on the retainer part <NUM>. For example, the upper plate part <NUM> is fixed to the upper surface of the retainer part <NUM>. The carried object <NUM> is mounted on the upper surface of the upper plate part <NUM>. The upper plate part <NUM> of this embodiment is structured such that a top plate <NUM> is mounted on a high-rigidity plate <NUM> formed by a hardened plate, etc. Further, the upper plate part <NUM> is circular in a plan view. The opening above each through hole <NUM> is blocked by the high-rigidity plate <NUM>. Therefore, the spherical body <NUM> is in contact with the high-rigidity plate <NUM>. The retainer part <NUM> and the upper plate part <NUM> may be formed by the same member and integrated with each other.

The lower unit <NUM> includes a lower plate part <NUM> and a guide part <NUM>. The lower plate part <NUM> is formed by, for example, a high-rigidity plate such as a hardened plate and is fixed to the upper surface of the base plate <NUM>. The upper unit <NUM> is mounted on the lower plate part <NUM>. In this state, the spherical body <NUM> is in contact with the upper surface of the lower plate part <NUM>. The upper unit <NUM> can move on the upper surface of the lower unit <NUM> as the spherical body <NUM> rolls on the upper surface of the lower plate part <NUM>.

The central region on the upper surface of the lower plate part <NUM> forms a region of movement <NUM> of the upper unit <NUM>. The upper unit <NUM> can move within the region of movement <NUM>. The guide part <NUM> has a frame shape and marks the region of movement <NUM> by being fixed to the upper surface of the lower plate part <NUM>. The guide part <NUM> extends on the peripheral part of the upper surface of the lower plate part <NUM> and surrounds the outer circumference of the region of movement <NUM>. The region of movement <NUM> of this embodiment is circular in a plan view. The upper unit <NUM> is restricted from moving outside the region of movement <NUM> by butting against the guide part <NUM>. The lower plate part <NUM> and the guide part <NUM> may be formed by the same member and integrated with each other.

The tilting structure <NUM> tilts the region of movement <NUM> relative to the horizontal plane HP and guides the upper unit <NUM> on which the carried object <NUM> is not mounted toward the reference position located on the lower side of the tilt. <FIG> shows that the upper unit <NUM> is located at the reference position. The horizontal plane HP is the plane of installation of the positioning apparatus <NUM> or the rack restriction apparatus <NUM> or the floor face. Providing a tilt in the region of movement <NUM> allows the upper unit <NUM>, on which the carried object <NUM> is not mounted and to which a load is not exerted from outside, to move toward the lower side of the tilt under its own weight. The upper unit <NUM> moves downs the tilt of the region of movement <NUM> and comes to a stop at a position where it butts against the guide part <NUM>. The position represents the reference position. The tilting angle of the region of movement <NUM> relative to the horizontal plane HP is, for example, <NUM> degrees.

As described above, the tilting structure <NUM> is formed by the leg part <NUM>. By configuring some leg parts <NUM> of the tilting structure <NUM> to be longer than the other leg parts <NUM>, the base plate <NUM> is tilted relative to the horizontal plane HP. Since the lower plate part <NUM> is fixed to the upper surface of the base plate <NUM>, the entirety of the lower plate part <NUM>, including the region of movement <NUM>, can be tilted by tilting the base plate <NUM>. The tilting structure <NUM> of this embodiment tilts the base plate <NUM> by extending the leg part <NUM> provided toward the exit frame <NUM> farther than the leg part <NUM> provided toward the entrance frame <NUM>. Therefore, the upper unit <NUM> is nearer the entrance frame <NUM> as shown in <FIG>. In the positioning apparatus <NUM> of this embodiment, therefore, the reference position is eccentrically located toward the upstream side in the direction of advancement of the carried object <NUM>.

Tilting the base plate <NUM> such that the exit frame <NUM> is higher and the entrance frame <NUM> is lower ensures that the end of the support shaft <NUM> is higher than the base thereof. This restricts the electrode hoop <NUM> from being dislodged from the support shaft <NUM> while the carried object <NUM> is mounted on the rack restriction apparatus <NUM>.

The positioning apparatus <NUM> includes a first attraction member <NUM> and a second attraction member <NUM> that attract each other by a magnetic force. At least one of the first attraction member <NUM> and the second attraction member <NUM> is a magnet (permanent magnet) or an electromagnet, and the other is a magnet, an electromagnet, or a ferromagnetic body. Materials forming the first attraction member <NUM> and the second attraction member <NUM> are exemplified by a hard magnetic body such as a neodymium-iron-boron magnet, a ferrite magnet, and an alnico magnet, and a soft magnetic body such as a magnetic steel sheet, a magnetic stainless steel, sendust, and a soft magnetic composite (SMC).

The first attraction member <NUM> is provided in a region in the lower unit <NUM> on the lower side of the tilt. In other words, the first attraction member <NUM> is provided near the reference position. In this embodiment, the first attraction member <NUM> is fixed to the guide part <NUM>. The second attraction member <NUM> is provided in a region in the upper unit <NUM> on the lower side of the tilt. In this embodiment, the second attraction member <NUM> is provided in the upper unit <NUM> such that the top plate <NUM> is formed by the second attraction member <NUM>. The entirety of the top plate <NUM> may be formed by the second attraction member <NUM>, or only a region in the top plate <NUM> on the lower side of the tilt may be formed by the second attraction member <NUM>. Alternatively, the second attraction member <NUM> may be provided in the retainer part <NUM> or the high-rigidity plate <NUM>.

The region in the lower unit <NUM> on the lower side of the tilt is a region that includes a part closest to the entrance frame <NUM> in the region of movement <NUM> (circular in a plan view). Further, the region in the upper unit <NUM> on the lower side of the tilt is a region that includes a part closest to the entrance frame <NUM> in the second attraction member <NUM> (circular in a plan view). The first attraction member <NUM> and the second attraction member <NUM> are provided such that they are opposite to other while the upper unit <NUM> is at the reference position. This allows the upper unit <NUM> to remain at the reference position in a stable manner.

As described above, the positioning apparatus <NUM> according to this embodiment includes the upper unit <NUM>, the lower unit <NUM>, and the tilting structure <NUM>. The upper unit <NUM> includes the spherical body <NUM>, the retainer part <NUM> that retains the spherical body <NUM>, and the upper plate part <NUM> provided on the retainer part <NUM> and adapted to carry the carried object <NUM>. The lower unit <NUM> includes the lower plate part <NUM> on which the upper unit <NUM> is mounted and the guide part <NUM> that marks the region of movement <NUM> of the upper unit <NUM> on the upper surface of the lower plate part <NUM>. The tilting structure <NUM> tilts the region of movement <NUM> relative to the horizontal plane HP and guides the upper unit <NUM> on which the carried object <NUM> is not provided toward the reference position located on the lower side of the tilt.

According to the positioning apparatus <NUM> of this embodiment, the upper unit <NUM> on which the carried object <NUM> is not mounted can be returned to the reference position automatically by utilizing the gravitational force exerted on the upper unit <NUM>. This helps reduce the number of components constituting the positioning apparatus <NUM> and simplify the structure. Further, the size and the manufacturing cost of the positioning apparatus <NUM> can be reduced. Further, the durability of the positioning apparatus <NUM> can be increased. The upper unit <NUM> always remains at the reference position when the carried object <NUM> is mounted on the rack restriction apparatus <NUM>. Therefore, variation in the range of positions of the carried object <NUM> that can be adjusted by the positioning apparatus <NUM> is avoided.

Further, the positioning apparatus <NUM> includes the base plate <NUM> that supports the lower unit <NUM>. The base plate <NUM> includes the leg part <NUM> that projects from the lower surface, and the tilting structure <NUM> is formed by the leg part <NUM>. This makes it possible to provide a tilt in the region of movement <NUM> with a simple structure.

Further, the positioning apparatus <NUM> includes the first attraction member <NUM> and the second attraction member <NUM> that attract each other by a magnetic force. The first attraction member <NUM> is provided in the region in the lower unit <NUM> on the lower side of the tilt, and the second attraction member <NUM> is provided in the region in the upper unit <NUM> on the lower side of the tilt. This can maintain a state in which the upper unit <NUM> remains at the reference position in a stable manner.

Embodiment <NUM> shares common features with embodiment <NUM> except for the tilting structure <NUM>. The following description of this embodiment highlights features different from those of embodiment <NUM>, and the description of the common features will be simplified or omitted. <FIG> is a cross-sectional view of the positioning apparatus <NUM> according to embodiment <NUM>.

The positioning apparatus <NUM> includes the upper unit <NUM> that includes the spherical body <NUM>, the retainer part <NUM> and the upper plate part <NUM>, the lower unit <NUM> that includes the lower plate part <NUM> and the guide part <NUM>, and the tilting structure <NUM> that tilts the region of movement <NUM> relative to the horizontal plane HP to guide the upper unit <NUM> toward the reference position. Further, the positioning apparatus <NUM> includes the base plate <NUM> that supports the lower unit <NUM>.

The base plate <NUM> of this embodiment includes a graded change part <NUM> in which the thickness 20T of the part that overlaps the region of movement <NUM> in the vertical direction is progressively smaller from one end of the region of movement <NUM> toward the other. In this embodiment, the thickness 20T is progressively smaller from the side of the exit frame <NUM> toward the entrance frame <NUM> over the entirety of the base plate <NUM>. Therefore, the graded change part <NUM> is provided over the entirety of the base plate <NUM>. Provision of the graded change part <NUM> tilts the upper surface of the base plate <NUM> relative to the horizontal plane HP. The lower plate part <NUM> is fixed to the upper surface of the base plate <NUM> so that the graded change part <NUM> also tilts the region of movement <NUM>. Therefore, the tilting structure <NUM> of this embodiment is formed by the graded change part <NUM>. The feature provides the same advantage as that of embodiment <NUM>.

The positioning apparatus <NUM> includes the upper unit <NUM> that includes the spherical body <NUM>, the retainer part <NUM> and the upper plate part <NUM>, the lower unit <NUM> that includes the lower plate part <NUM> and the guide part <NUM>, and the tilting structure <NUM> that tilts the region of movement <NUM> relative to the horizontal plane HP to guide the upper unit <NUM> toward the reference position.

The lower unit <NUM> of this embodiment includes a leg part <NUM> that projects downward. By way of one example, the leg part <NUM> projects downward from the lower surface of the lower plate part <NUM>. Further, a plurality of leg parts <NUM> are provided at each of the edge of the lower plate part <NUM> toward the entrance frame <NUM> and the edge toward the exit frame <NUM>. Like the leg part <NUM>, each leg part <NUM> is formed by an adjuster bolt, etc. and can extend or contract independently. The tilting structure <NUM> of this embodiment is formed by the leg part <NUM>. By configuring some leg parts <NUM> of the tilting structure <NUM> to be longer than the other leg parts <NUM>, the region of movement <NUM> is tilted relative to the horizontal plane HP. The feature provides the same advantage as that of embodiment <NUM>.

The lower plate part <NUM> of this embodiment includes a graded change part <NUM> in which the thickness 58T of the part that includes the region of movement <NUM> is progressively smaller from one end of the region of movement <NUM> toward the other. In this embodiment, the thickness 58T is progressively smaller from the side of the exit frame <NUM> toward the side of the entrance frame <NUM> over the entirety of the lower plate part <NUM>. Therefore, the graded change part <NUM> is provided over the entirety of the lower plate part <NUM>. Provision of the graded change part <NUM> tilts the region of movement <NUM> relative to the horizontal plane HP. Therefore, the tilting structure <NUM> of this embodiment is formed by the graded change part <NUM>. The feature provides the same advantage as that of embodiment <NUM>.

Embodiment <NUM> shares common features with embodiment <NUM> except that a biasing part is provided. The following description of this embodiment highlights features different from those of embodiment <NUM>, and the description of the common features will be simplified or omitted. <FIG> are plan views of the positioning apparatus <NUM> according to embodiment <NUM>. <FIG> shows a state in which the carried object <NUM> (not shown) is mounted on the upper unit <NUM>, and <FIG> shows a state in which the carried object <NUM> is not mounted on the upper unit <NUM>.

The positioning apparatus <NUM> of this embodiment includes a biasing part <NUM> that biases the upper unit <NUM> toward the reference position. The biasing part <NUM> includes, by way of one example, a pair of spring cylinders <NUM> and a biasing plate <NUM> attached to the end of the pair of spring cylinders <NUM>. Each spring cylinder <NUM> is slidably fixed to a region in the guide part <NUM> toward the exit frame <NUM> (the upper side of the tilt). The end of each spring cylinder <NUM> can advance and recede relative to the region of movement <NUM>, and the built-in coil spring (not shown) biases the end in the direction of advancement toward the region of movement <NUM>. The biasing plate <NUM> comes into contact with the side surface of the upper unit <NUM> and biases the upper unit <NUM> toward the entrance frame <NUM> (the lower side of the tilt) by a biasing force of the spring cylinder <NUM>.

When the carried object <NUM> is mounted on the positioning apparatus <NUM> and is drawn by the drawing mechanism <NUM> toward the exit frame <NUM>, the upper unit <NUM> is displaced toward the exit frame <NUM> against the biasing force of the spring cylinder <NUM> (<FIG>). When the carried object <NUM> is removed from the positioning apparatus <NUM>, the upper unit <NUM> is pressed by the biasing plate <NUM> toward the reference position (<FIG>). This ensures that the upper unit <NUM> is guided toward the reference position more properly.

Claim 1:
A positioning apparatus (<NUM>) comprising:
an upper unit (<NUM>) that includes a spherical body (<NUM>), a retainer part (<NUM>) that retains the spherical body (<NUM>), and an upper plate part (<NUM>) provided on the retainer part (<NUM>) and adapted to carry a carried object (<NUM>);
a lower unit (<NUM>) that includes a lower plate part (<NUM>) on which the upper unit (<NUM>) is mounted and a guide part (<NUM>) that marks a region of movement (<NUM>) of the upper unit (<NUM>) on the lower plate part (<NUM>);
characterized in that the positing apparatus further comprises
a tilting structure (<NUM>) that tilts the region of movement (<NUM>) relative to a horizontal plane (HP) and guides the upper unit (<NUM>), on which the carried object (<NUM>) is not mounted, toward a reference position located on a lower side of a tilt, the reference position being a position where the carried object (<NUM>) is to be mounted on the upper plate part (<NUM>); the reference position being a position where the upper unit (<NUM>) butts against the guide part (<NUM>); the upper unit (<NUM>) on which the carried object (<NUM>) is not mounted can be returned to the reference position automatically by utilizing gravitational force.