JP6489428B2 - Centering gripping method and centering gripping device for cylindrical article - Google Patents

Description

  The present invention relates to a method and an apparatus for centering and gripping cylindrical articles such as those obtained by winding a sheet-like product into a cylindrical shape, and wrapping food or clothing in a cylindrical shape.

In production equipment that winds up sheet-like products and discharges them into cylinders, or wraps and discharges food and clothing in cylinders, products that are continuously discharged (tubular articles) It is necessary to move to the product storage (product storage space). The movement of this product has conventionally relied on manual labor, but has recently been automated due to lack of human resources.
The cylindrical article discharged from the production apparatus is automatically moved to the product place using a robot or the like. Specifically, the cylindrical article is discharged from the discharge unit of the production apparatus and placed on the floor in an upright state with the bottom face down, by a gripping device attached to the tip of the robot arm. Is gripped and lifted, the robot arm is moved to the product place, the grip of the cylindrical article is released at a predetermined position, the cylindrical article is dropped, and the movement of the cylindrical article is finished.
In this case, the gripping device includes a plurality of gripping claws arranged at equal intervals in the circumferential direction and a mechanism for simultaneously moving the plurality of gripping claws toward the center of the circle, and performs centering of the cylindrical article. After that, the outer peripheral surface of the cylindrical article can be gripped.
Japanese Patent Laid-Open No. 5-212644 (Patent Document 1) discloses a tool positioning device that reliably performs centering of a work object and grips the work object.

By the way, some of the cylindrical articles as described above are flexible and easily deformed, and the gripping pressure at the time of gripping (pressure for pressing the gripping claws against the outer peripheral surface of the cylindrical article) cannot be increased too much. For this reason, it is necessary to use a gripping claw having an outer surface with a large friction coefficient with respect to the outer peripheral surface of the cylindrical article so that the cylindrical article gripped by the gripping claw does not slide off from the gripping claw.
However, when the coefficient of friction between the outer surface of the gripping claw and the outer peripheral surface of the cylindrical article is increased, the outer peripheral surface of the cylindrical article is moved relative to the outer surface of the gripping claw when the gripping claw is moved to center the cylindrical article. Does not slip, the centering of the cylindrical article becomes uncertain, the cylindrical article is gripped in a state where the cylindrical article is not centered, and the cylindrical article cannot be lifted and moved.

JP-A-5-212644

  The problem to be solved by the present invention is to make it possible to reliably perform centering and gripping even on a flexible and easily deformable tubular article.

  The present invention provides a plurality of pressing members around a cylindrical article placed in an upright state with the bottom face down at a position deviating from the centering center on a horizontal plane at regular intervals in the circumferential direction with respect to the centering center. And the gripping member, the plurality of pressing members are moved in the centering center direction, the outer surface of the plurality of pressing members is pressed against the outer peripheral surface of the cylindrical article, and the center of the cross section of the cylindrical article is A centering step of moving the cylindrical article so as to coincide with the centering center, and after performing the centering step, the plurality of gripping members are moved toward the centering center, and the outer surfaces of the plurality of gripping members are A gripping step of pressing the outer peripheral surface of the cylindrical article and gripping the outer peripheral surface of the cylindrical article, and the friction coefficient between the outer surface of the plurality of pressing members and the outer peripheral surface of the cylindrical article is Providing a centering holding method of a small cylindrical article than the friction coefficient between the outer surface and the outer peripheral surface of the tubular article of the plurality of gripping members, it is intended to solve the above problems.

  The present invention provides a plurality of cylindrical articles arranged in a circumferential direction with respect to the centering center around a cylindrical article placed in an upright state with the bottom face down at a position off the centering center on a horizontal plane. And pressing the outer surface of the plurality of pressing members against the outer peripheral surface of the cylindrical article, the center of the cross-section of the cylindrical article being the center Centering means for moving the cylindrical article so as to coincide with the centering center and performing centering; and a plurality of gripping members arranged at regular intervals in the circumferential direction with respect to the centering center; After centering the cylindrical article, the plurality of gripping members are moved in the centering center direction, and outer surfaces of the plurality of gripping members are moved to the cylindrical article. Gripping means that presses against the peripheral surface and grips the outer peripheral surface of the cylindrical article, and the coefficient of friction between the outer surface of the plurality of pressing members and the outer peripheral surface of the cylindrical article is the outer surface of the plurality of gripping members. A centering gripping device for a cylindrical article having a smaller coefficient of friction with the outer peripheral surface of the cylindrical article is provided to solve the above problems.

  The centering gripping method for a cylindrical article according to the present invention includes a cylindrical article placed in an upright position with the bottom face down at a position off the centering center on a horizontal plane, and circumferentially with respect to the centering center. A plurality of pressing members and gripping members are arranged at regular intervals, the plurality of pressing members are moved in the centering center direction, and the outer surfaces of the plurality of pressing members are pressed against the outer peripheral surface of the cylindrical article. A centering step of moving the cylindrical article so that the center of the cross section of the shaped article coincides with the centering center, and after performing the centering step, the plurality of gripping members are moved toward the centering center, A gripping step of pressing the outer surfaces of the plurality of gripping members against the outer peripheral surface of the cylindrical article and gripping the outer peripheral surfaces of the cylindrical articles, The friction coefficient with the outer peripheral surface of the cylindrical article is smaller than the friction coefficient between the outer surface of the plurality of gripping members and the outer peripheral surface of the cylindrical article. Is pressed against the outer peripheral surface of the cylindrical article to move the cylindrical article to the centering center, and the outer surface of the plurality of pressing members and the outer peripheral surface of the cylindrical article slip, thereby centering the cylindrical article. This can be performed reliably, and in the gripping step, there is an effect that the outer peripheral surface of the cylindrical article can be securely gripped by the plurality of gripping members.

  The cylindrical article centering gripping device of the present invention is provided in a circumferential direction with respect to the centering center around the cylindrical article placed in an upright state with the bottom face down at a position off the centering center on the horizontal plane. A plurality of pressing members arranged at regular intervals, the plurality of pressing members are moved in the centering center direction, and the outer surfaces of the plurality of pressing members are pressed against the outer peripheral surface of the cylindrical article; Centering means for moving the cylindrical article so that the center of the cross section of the article coincides with the centering center, and a plurality of grips arranged at regular intervals in the circumferential direction with respect to the centering center A plurality of gripping members are moved in the centering center direction after the cylindrical article is centered by the centering means. A gripping means for pressing the outer surface of the holding member against the outer peripheral surface of the cylindrical article and gripping the outer peripheral surface of the cylindrical article, and the coefficient of friction between the outer surface of the plurality of pressing members and the outer peripheral surface of the cylindrical article Is smaller than the coefficient of friction between the outer surfaces of the plurality of gripping members and the outer peripheral surface of the cylindrical article, so that the centering means presses the outer surfaces of the plurality of pressing members against the outer peripheral surface of the cylindrical article. When performing the interleaving to move the cylindrical article to the centering center, the outer surface of the plurality of pushing members and the outer peripheral surface of the cylindrical article can slip, and the cylindrical article can be reliably centered. In the above, there is an effect that the outer peripheral surface of the cylindrical article can be reliably gripped by the plurality of gripping members.

It is a top view which shows the principal part of one Embodiment of the centering holding | grip apparatus of the cylindrical article of this invention. It is a perspective view which expands and shows the drive mechanism of the pushing member and holding member of the centering holding apparatus shown in FIG. (A) is a perspective view of the centering gripping device shown in FIG. 1 with its outer surface facing upward, and (b) is a perspective view of the centering gripping device shown in FIG. 1 with its gripping member facing upward. FIG. It is the perspective view which made the cylindrical article used as the operation | work object of the centering holding | grip apparatus shown in FIG. 1 into the upright state by making the bottom face down. It is a perspective view which shows the modification of the drive mechanism of the pushing member and holding member of the centering holding apparatus shown in FIG. It is a top view which shows the state before the centering holding | grip apparatus shown in FIG. 1 performs centering of a cylindrical article. It is a top view which shows the state after the centering holding | grip apparatus shown in FIG. 1 centered a cylindrical article. It is a top view which shows the state which the centering holding | grip apparatus shown in FIG. 1 hold | gripped the cylindrical article.

[Configuration of centering gripping device]
First, the configuration of the centering gripping device of the present invention will be described.
FIG. 1 is a plan view showing a main part of an embodiment of a centering gripping device for a cylindrical article according to the present invention, and FIG. 2 is an enlarged view of a pushing member and a driving mechanism for the gripping member of the centering gripping device shown in FIG. It is a perspective view shown. In the figure, 1 is a centering gripping device, 2 is a drive mechanism of a pushing member and a gripping member, 3 is a pushing member, 4 is a gripping member, 5 is an L-shaped rod, 6 and 7 are air cylinders, and C is a centering center. is there.
As shown in FIG. 1, in the centering gripping device 1, three drive mechanisms 2 are arranged at equal intervals in the circumferential direction with respect to the centering center C with the outer surface of the pressing member and the gripping member facing the centering center C. Is arranged in. These three drive mechanisms 2 are connected to each other and attached to the tip of a robot arm (not shown). In the present embodiment, the number of drive mechanisms is three, but the number of drive mechanisms 2 only needs to be plural, and the number of drive mechanisms 2 is appropriately determined according to the size, weight, etc. of the cylindrical article that is the work target. . In addition, the arrangement of the drive mechanisms 2 is preferably an equal interval, but is not limited to this, and may be a fixed interval.
As shown in FIG. 2, in the drive mechanism 2, the push member 3 is connected to the piston rod 6 a of the air cylinder 6 via the L-shaped rod 5, and the push member 3 is operated by operating the air cylinder 6. Move in the direction of the centering center C. The gripping member 4 is connected to the piston rod 7a of the air cylinder 7, and the gripping member 4 moves in the direction of the centering center C by operating the air cylinder 7. In addition, an air cylinder 7 is connected to the rod 5, and by operating the air cylinder 6, the holding member 4 together with the push member 3 moves in the direction of the centering center C together with the air cylinder 7.

[Pushing member, gripping member]
FIG. 3A is a perspective view of the pressing member 3, and FIG. 3B is a perspective view of the gripping member 4.
As shown in FIG. 2A, the pressing member 3 is formed by bending a metal plate such as aluminum or a plastic plate into a dogleg shape. And the outer surface 3a which is a surface of a small angle side turns into a surface which faces the cylindrical article used as a work object. Further, the inclination angle of the outer surface 3a is appropriately determined in accordance with the size (diameter) of the cylindrical article within a range of 5 to 30 degrees.
As shown in FIG. 4B, the gripping member 4 has trapezoidal blocks 4a and 4b fixed symmetrically on the support plate 4c with the inclined surfaces facing upward, and the rubber sheet 4d is attached to the inclined surfaces of the trapezoidal blocks 4a and 4b. 4e is fixed. The outer surfaces 4ds and 4es, which are the surfaces of the rubber sheets 4d and 4e, are surfaces facing the cylindrical article to be worked. The trapezoidal blocks 4a and 4b and the support plate 4c are made of a rigid material such as metal or plastic. Further, the inclination angle of the outer surfaces 4ds, 4es (trapezoidal blocks 4a, 4b) is in the range of 5 to 30 degrees according to the size (diameter) of the cylindrical article, similarly to the inclination angle of the outer surface 3a of the push member 3. It is decided appropriately.

[Cylindrical articles]
FIG. 4 is a perspective view of the cylindrical article.
As shown in FIG. 4, the cylindrical article 10 has a vertically long cylindrical shape, and is placed in an upright state with the bottom surface 10b facing down. In the present embodiment, the cylindrical article 10 is a plastic sheet wound with kraft paper, and is flexible and easily deformed. In the present invention, the cylindrical article is not limited to the winding of the plastic sheet, and may be any article having a cylindrical shape, such as a food or clothing packaged in a cylindrical shape. Moreover, the cross section of the cylindrical article is not limited to a circle, and may be a polygon.

[Friction coefficient between push member / gripping member and cylindrical article]
Since the cylindrical article 10 is packaged with kraft paper, the outer peripheral surface 10a has high smoothness. And the outer surface 3a of the pushing member 3 is also a smooth surface, and the friction coefficient between the outer surface 3a and the outer peripheral surface 10a is small. On the other hand, the outer surfaces 4ds, 4es of the holding member 4 are the surface of the rubber sheet and are not smooth, and the friction coefficient between the outer surfaces 4ds, 4es and the outer peripheral surface 10a is large.
That is, the friction coefficient between the outer surface 3 a of the push member 3 and the outer peripheral surface 10 a of the cylindrical article 10 is smaller than the friction coefficient between the outer surfaces 4 ds and 4 es of the gripping member 4 and the outer peripheral surface 10 a of the cylindrical article 10. .
For this reason, the outer surface 3 of the push member 3 is easily slipped with respect to the outer peripheral surface 10 a of the cylindrical article 10, but the outer surfaces 4 ds and 4 es of the gripping member 4 are relative to the outer peripheral surface 10 a of the cylindrical article 10. It is hard to slip.

[Modified example of drive mechanism of push member and grip member]
FIG. 5 is a perspective view showing a modification of the drive mechanism 2 for the push member and the gripping member.
The push member and gripping member drive mechanism 2 shown in FIG. 2 has a push member 3 and a gripping member 4 arranged in the vertical direction, but the push member and gripping member drive mechanism 12 shown in FIG. The gripping member 14 is arranged in the horizontal direction. In the drive mechanism 12, the push member 13 is provided with window holes 13a and 13b, and the holding member 14 having the trapezoidal blocks 14a and 14b fixed to the support plate 14c is provided with a through hole 14d. For this reason, even if only the gripping member 14 is moved in the direction of the centering center C, the pressing member 13 and the gripping member 14 do not interfere with each other, and the trapezoidal blocks 4a and 4b pass through the window holes 13a and 13b, thereby Can be gripped.
In the drive mechanism 12, similarly to the drive mechanism 2, the gripping member 14 is connected to a piston rod 17 a of a gripping member driving air cylinder (not shown), and the pressing member 13 and the gripping member driving air cylinder are The rod 15 is connected to a piston rod of a push member driving air cylinder (not shown). Therefore, in the drive mechanism 12, similarly to the drive mechanism 2, by operating the push member driving air cylinder, the push member 13 and the gripping member 14 move in the direction of the centering center C, and the gripping member drive air cylinder. By actuating, only the gripping member 14 moves in the direction of the centering center C.
A rubber sheet (not shown) is fixed to the inclined surfaces of the trapezoidal blocks 14 a and 14 b of the gripping member 14 in the same manner as the gripping member 4.

[Centering gripping method for cylindrical articles]
Next, a centering gripping method for a cylindrical article using the centering gripping device 1 will be described.
FIG. 6 is a plan view showing a state before the centering gripping device 1 performs centering of the cylindrical article 10, and FIG. 7 is a plan view showing a state after the centering gripping apparatus 1 performs centering of the cylindrical article 10. FIG. 8 is a plan view showing a state in which the centering gripping device 1 grips the cylindrical article 10.
As shown in FIG. 6, the tubular article 10 is placed on a horizontal surface (floor surface) in an upright state with the bottom surface 10 b facing down at a position where the center of the cross section deviates from the centering center C. Then, the three drive mechanisms 2 of the centering gripping device 1 are arranged in the circumferential direction with respect to the centering center C, the outer surface 3a of the pushing member 3 and the outer surfaces 4ds, 4es of the gripping member 4 are directed toward the centering center C, etc. Arranged at intervals.
First, the air cylinder 6 is operated, and the pushing member 3 and the gripping member 4 are simultaneously moved in the direction of the centering center C. Since the cylindrical article 10 is located closer to the right drive mechanism 2, the outer surface 3a of the pushing member 3 of the right drive mechanism 2 first contacts the outer peripheral surface 10a of the cylindrical article 10, and then the left drive. The outer surface 3 a of the push member 3 of the mechanism 2 contacts the outer peripheral surface 10 a of the cylindrical article 10, and finally the outer surface 3 a of the push member 3 of the central drive mechanism 2 contacts the outer peripheral surface 10 a of the cylindrical article 10. At this time, since the friction coefficient between the outer surface 3a of the pressing member 3 and the outer peripheral surface 10a of the cylindrical article 10 is small, the outer surface 3a of the pressing member 3 and the outer peripheral surface 10a of the cylindrical article 10 are slippery. Then, it is pushed by the pushing member 3 and moves in the direction of the centering center C, and as shown in FIG. 7, the centering center C and the center of the cross section of the tubular article 10 coincide with each other, and the centering is performed reliably.
Thus, in the state where the centering center C and the center of the cross section of the cylindrical article 10 coincide (centered state) (FIG. 7), the operation of the air cylinder 6 is stopped, the air cylinder 7 is operated, and the gripping member 4 outer surfaces 4ds, 4es are pressed against the outer peripheral surface 10a of the cylindrical article 10, and the cylindrical article 10 is held by the holding member 4 (FIG. 8). At this time, since the friction coefficient between the outer surface 4ds of the gripping member 4 and the outer surface 3a of the 4es cylindrical article 10 and the outer peripheral surface 10a is larger than the friction coefficient between the outer surface 3a of the pressing member 3 and the outer peripheral surface 10a of the cylindrical article 10, The outer surfaces 4ds, 4es of the holding member 4 and the outer peripheral surface 10a of the cylindrical article 10 are difficult to slip. For this reason, the cylindrical article 10 can be lifted in the gripped state without making the pressing force (gripping pressure) of the gripping member 4 against the cylindrical article 10 so strong, and the tubular article 10 is reliably deformed without being deformed. Can be gripped.

  The centering gripping method and centering gripping device for a cylindrical article according to the present invention can reliably center a cylindrical article that is flexible and easily deformed, and can securely grip the cylindrical article without deformation. Can do.

DESCRIPTION OF SYMBOLS 1 Centering holding device 2, 12 Push member and holding member drive mechanism 3, 13 Push member 3a Outer surface 4, 14 Holding member 4a, 4b, 14a, 14b Trapezoid block 4c, 14c Support plate 4d, 4e Rubber sheet 4ds, 4es Outer surface 5, 15 Rod 6, 7 Air cylinder 6a, 7a, 17a Piston rod 10 Cylindrical article 10a Outer peripheral surface 10b Bottom surface C Centering center

Claims (2)

A plurality of pressing members and gripping members are arranged at regular intervals in the circumferential direction with respect to the centering center around a cylindrical article placed in an upright position with the bottom face down at a position off the centering center on the horizontal plane. Place and
The plurality of pressing members are moved in the centering center direction so that the outer surfaces of the plurality of pressing members are pressed against the outer peripheral surface of the cylindrical article so that the center of the cross section of the cylindrical article coincides with the centering center. A centering step of moving the cylindrical article to
After performing the centering step, the plurality of gripping members are moved toward the centering center, the outer surfaces of the plurality of gripping members are pressed against the outer peripheral surface of the cylindrical article, and the outer peripheral surface of the cylindrical article is gripped. A gripping process,
A cylindrical article characterized in that a friction coefficient between an outer surface of the plurality of pressing members and an outer peripheral surface of the cylindrical article is smaller than a friction coefficient between an outer surface of the plurality of gripping members and an outer peripheral surface of the cylindrical article. Centering gripping method. A plurality of pushing members arranged at regular intervals in the circumferential direction with respect to the centering center around a cylindrical article placed in an upright state with the bottom face down at a position off the centering center on the horizontal plane The plurality of pressing members are moved toward the centering center, and the outer surfaces of the plurality of pressing members are pressed against the outer peripheral surface of the cylindrical article, and the center of the cross section of the cylindrical article coincides with the centering center. Centering means for moving the cylindrical article to perform centering,
A plurality of gripping members arranged at regular intervals in the circumferential direction with respect to the centering center, and after centering the cylindrical article by the centering means, the plurality of gripping members are moved in the centering center direction. A gripping means that moves, presses the outer surface of the plurality of gripping members against the outer peripheral surface of the cylindrical article, and grips the outer peripheral surface of the cylindrical article;
A cylindrical article characterized in that a friction coefficient between an outer surface of the plurality of pressing members and an outer peripheral surface of the cylindrical article is smaller than a friction coefficient between an outer surface of the plurality of gripping members and an outer peripheral surface of the cylindrical article. Centering gripping device.

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