JP6490991B2 - Stopper device - Google Patents

Description

  The present invention relates to a stopper device.

  Patent Document 1 discloses a stopper device including a stopper member that protrudes and protrudes in a direction orthogonal to a conveyance direction of a conveyance object by a roller conveyor. On the lower surface of the roller conveyor, an axial cylinder parallel to the transport direction and a link plate that moves forward and backward in the coaxial line direction by the cylinder are arranged. The link plate is provided with a pair of cam holes having an inclination angle in a direction opposite to the forward / backward movement axis. Each cam hole is provided with a stopper member via a guide pin. As the link plate moves forward and backward, the stopper members of the respective cam holes alternately protrude above the conveying surface of the roller conveyor.

  Patent Document 2 discloses a transfer device including a conveyor line for transferring an article and a conveyor of an automated guided vehicle for transferring the article between the conveyor lines. A stopper member for preventing the article from dropping is attached to the end of the conveyor so as to be swingable about a support pin as a rotation axis. At the end of the conveyor line, there is provided a plate cam that is long in the moving direction of the automatic guided vehicle, has a high middle portion, and is bent at both ends obliquely downward for guidance. A cam follower that rides on the plate cam and rolls is provided at a portion below the support pin of the stopper member. In accordance with the arrival and departure of the automatic guided vehicle, the cam follower rides on the plate cam and temporarily interferes and separates, so that the operation state and the release state of the stopper member are switched.

  Patent Document 3 discloses a pallet transport device including a stopper capable of preventing transport due to its own weight. When the pallet is transported to a position where it abuts against the stopper, the pallet holding table is lowered by the actuator. When the stopper is lowered from the conveyance surface as the holding table is lowered, an escape for preventing conveyance of the next pallet protrudes from the conveyance surface.

Japanese Utility Model Publication No. 5-56834 JP 2000-44047 A Japanese Unexamined Patent Publication No. 2014-210639

  Since the stopper device is used only for temporarily holding a workpiece, it is desired to make the stopper device as simple and low-cost as possible. In designing an inexpensive stopper device, there are many that raise and lower the stopper plate using a cam mechanism.

  The present inventor has found that there is the following problem in a stopper device that raises and lowers a stopper plate having a cam groove by using a cam rotor and a cam ring. In such a stopper device, when the cam ring is rotated by the motor, the cam roller engaged with the cam ring rolls in the cam groove, and the stopper plate rises together with the cam roller.

  In order to reduce the cost of the stopper device, an inexpensive motor for rotating the cam ring is used. Since such an inexpensive motor has low stop accuracy, the cam ring may not be stopped at the rising end. If an external force is generated in a downward direction with the cam ring being displaced from the rising end, the stopper plate is unintentionally lowered, which may cause defective workpieces. Although a solution method of selecting a motor with higher stopping accuracy is conceivable, the cost increases.

  The present invention has been made against the background of the above problems, and an object of the present invention is to provide a stopper device capable of preventing the stopper plate from being unintentionally lowered at low cost. .

  A stopper device according to an embodiment includes a stopper plate having a cam groove, a cam roller that rolls in the cam groove, and engages with the cam roller to rotate the cam roller to roll in the cam groove. A cam ring that raises and lowers the stopper plate between a descending end and an ascending end, and the cam groove is disposed in the cam groove when the stopper plate is positioned at the ascending end. The R-shaped part is provided.

  According to the present invention, it is possible to provide a stopper device capable of preventing unintentional lowering of the stopper plate at low cost.

It is a figure which shows the structure of the stopper apparatus which concerns on embodiment. In the stopper device concerning an embodiment, it is a figure showing the state where a stopper plate exists in a falling end. In the stopper device concerning an embodiment, it is a figure showing the state where a stopper plate exists in a rising end. In a stopper device concerning an embodiment, it is a figure showing a direction of external force applied when a stopper plate shifts from a rising end. In the stopper device of the embodiment, when the radius of the R-shaped portion is equal to the radius of the cam ring, it is a diagram illustrating the direction of external force applied when the stopper plate is displaced from the rising end. In the stopper device of the embodiment, when the radius of the R-shaped portion is smaller than the radius of the cam ring, it is a diagram showing the direction of external force applied when the stopper plate is displaced from the rising end. It is a figure which shows the structure of the stopper apparatus of a comparative example. It is a figure which shows the state which has a stopper plate in a falling end in the stopper apparatus of a comparative example. In the stopper apparatus of a comparative example, it is a figure which shows the state which has a stopper plate in a raise end. In the stopper device of the comparative example,

  Hereinafter, embodiments will be described with reference to the drawings. In the following drawings, components having the same action are denoted by the same reference numerals. In addition, the dimensional relationship in each figure does not reflect the actual dimensional relationship.

  A stopper device according to an embodiment will be described with reference to FIGS. FIG. 1 is a diagram illustrating a configuration of the stopper device 10. FIG. 2 shows a state in which the stopper plate is at the lower end in the stopper device 10. FIG. 3 shows a state in which the stopper plate is at the rising end in the stopper device 10. FIG. 4 is a diagram illustrating the direction of external force applied when the stopper plate is displaced from the rising end.

  As shown in FIGS. 1 to 4, the stopper device 10 includes a stopper plate 12 having a cam groove 11, a cam roller 13, and a cam ring 14. In FIG. 1, the cam ring 14 is not shown for simplification of the drawing. In each figure, components hidden behind other components are also drawn with solid lines.

  As shown in FIG. 1, the stopper plate 12 is provided with a cam groove 11. The cam groove 11 has a substantially rounded rectangular outline. That is, the cam groove 11 is composed of two long sides arranged opposite to each other and two semicircles joined to the end portions of these long sides. That is, the cam groove 11 has a shape in which a semicircle is joined to each of left and right ends of a rectangle. One long side of the cam groove 11 is linear, and an R-shaped portion 11a is provided on the other long side.

  The straight long side of the cam groove 12 is disposed along the lower end side of the stopper plate 11. The long side where the R-shaped portion 11a of the cam groove 11 is formed is disposed at a position farther from the lower end side of the stopper plate 12 than the linear long side. The R-shaped portion 11 a is formed at a substantially central portion of the upper long side of the cam groove 11. The radius of the R-shaped portion 11a is equal to or less than the radius of the cam ring 14.

  A cam roller 13 is disposed in the cam groove 11 so as to be able to roll. The cam ring 14 is rotationally driven by a motor (not shown). The cam ring 14 is an annular member in which a gear portion (not shown) is formed. The cam roller 13 is a roller pinion that engages with the cam ring 14. When the cam ring 14 is rotated, the cam roller 13 is rotated, and the cam roller 13 moves along the side where the R-shaped portion 11a in the cam groove 11 is disposed.

  The stopper plate 12 is supported by the cam roller 13 and moves up and down together with the cam roller 13. As the cam ring 14 rotates, the cam roller 13 rolls in the cam groove 11 and the stopper plate 12 is moved up and down between the lower end and the upper end.

  The lower end is the position of the stopper plate 12 when the cam roller 13 is at the lowermost part of the cam ring 14, and the upper end is the position of the stopper plate 12 when the cam roller 13 is at the uppermost part of the cam ring 14. is there. The position of the cam ring 14 when the stopper plate 12 is at the rising end is defined as the rising end stop position.

  FIG. 2 shows a state in which the stopper plate 12 is at the lower end. FIG. 3 shows a state where the stopper plate 12 is at the rising end. In FIG. 1, the dotted line indicates the position of the stopper plate 12 at the rising end, and the solid line indicates the position of the stopper plate 12 at the falling end. The cam roller 13 is disposed in the R-shaped portion 11a when the stopper plate 12 is positioned at the rising end.

  Here, the configuration of the stopper device according to the comparative example will be described with reference to FIGS. FIG. 7 is a view showing the structure of a stopper device of a comparative example. FIG. 8 shows a state where the stopper plate 12 is at the descending end. FIG. 9 shows a state in which the stopper plate 12 is at the rising end. In FIG. 7, the dotted line indicates the position of the stopper plate 12 at the rising end, and the solid line indicates the position of the stopper plate 12 at the falling end.

  As shown in FIG. 7, in the comparative example, the cam groove 110 has a rounded rectangular outline consisting of two straight parallel long sides and two semicircles joined to the ends of the long sides. doing. The two long sides are equal in length. In the stopper device of the comparative example, when the cam ring 14 is rotated by the motor, the cam roller 13 moves along the upper straight long side.

  As shown in FIG. 9, it is desirable to stop the cam ring 14 at a position where the stopper plate 12 is at the rising end. However, the cam ring 14 cannot be stopped at this position with an inexpensive motor stop accuracy. An error of about 15 ° occurs.

  FIG. 10 shows the component force when the external force is generated in the downward direction when the cam ring 14 stops at a position deviated by 15 ° from the position at which the stopper plate 12 is positioned at the rising end. As shown in FIG. 10, in the comparative example, the external force generated in the downward direction is dispersed in the center direction and the rotational direction of the cam ring 14.

  It can be seen that the component force in the rotational direction acts in the direction of rotating the cam ring 14 in the left direction (counterclockwise). For this reason, the cam ring 14 may rotate counterclockwise, and the stopper plate 12 may unintentionally descend, causing a defective workpiece.

  On the other hand, with reference to FIG. 4, in the stopper device 10 according to the embodiment, an external force applied when the stopper plate 12 is displaced from the rising end will be described. FIG. 4 shows an example in which the cam ring 14 stops at a position deviated by 15 ° from the position when the stopper plate 12 is positioned at the rising end.

  As shown in FIG. 4, when an external force is generated in the stopper plate 12 in a state where the cam ring 14 is shifted from the rising end stop position, the cam roller 13 is tangent to the contact point with the R-shaped portion 11 a of the cam roller 13. External force is transmitted in the vertical direction. The external force generated in the downward direction is dispersed in the center direction and the rotational direction of the cam ring 14.

  As shown in FIG. 4, it can be seen that the component force in the rotational direction acts in a direction to rotate the cam ring 14 in the right direction (clockwise). For this reason, the cam ring 14 rotates clockwise, and the stopper plate 12 moves to the rising end. When the stopper plate 12 moves to the ascending end, the component force in the rotational direction is lost, and the rotation of the cam ring 14 is stopped.

  As described above, in the stopper device 10 according to the embodiment, even when an external force is applied to the stopper plate 12 downward when the cam ring 14 is displaced from the rising end stop position, the stopper plate 12 is unintentionally lowered. Nothing will happen. As a result, it is possible to prevent the occurrence of work defects.

  Here, the direction of the force generated when the radius of the R-shaped portion 11a is changed will be described with reference to FIGS. 5 and 6 also show a state in which the cam ring 14 is deviated by 15 ° from the rising end stop position, as described above.

  FIG. 5 shows an example in which the radius of the cam ring 14 and the radius of the R-shaped portion 11a are both 19 mm. As shown in FIG. 5, when an external force is generated downward in the stopper plate 12, the external force is transmitted from the stopper plate 12 to the cam roller 13 in a direction perpendicular to the tangent at the contact point between the R-shaped portion 11 a and the cam roller 13.

  When the radius of the R-shaped portion 11 a is equal to the radius of the cam ring 14, all the forces applied to the cam roller 13 work in the center direction of the cam ring 14. For this reason, the cam ring 14 maintains a stopped state without rotating.

  FIG. 6 shows an example in which the radius of the cam ring 14 is 19 mm and the radius of the R-shaped portion 11a is 17.5 mm. As shown in FIG. 6, when an external force is generated downward in the stopper plate 12, the external force is transmitted from the stopper plate 12 to the cam roller 13 in a direction perpendicular to the tangent at the contact point between the R-shaped portion 11 a and the cam roller 13.

  When the radius of the R-shaped portion 11 a is smaller than the radius of the cam ring 14, the force applied to the cam roller 13 is distributed in the center direction and the rotational direction of the cam ring 14. The component force in the rotation direction is a direction in which the cam ring 14 is rotated clockwise. For this reason, the cam ring 14 rotates clockwise and moves to the rising end stop position. When the cam ring 14 reaches the rising end stop position, the component force in the rotational direction is lost, and all the force is in the center direction of the cam ring 14. Therefore, the cam ring 14 stops at the rising end stop position.

  As described above, by providing the cam groove 11 with the R-shaped portion 11a having a radius equal to or less than the radius of the cam ring 14 so that the cam roller 13 is disposed when the stopper plate 12 is positioned at the rising end, the stopper plate 12 Unintentional descent can be prevented.

  In equipment such as a reversing machine that lifts a workpiece and changes the posture of the workpiece, a cam structure may be used for a part such as a clamper that holds the workpiece. If the clamper is loosened due to an external force or the like, the workpiece may drop. Therefore, the clamper is made difficult to loosen by using a cam mechanism, and the actuator for generating the clamping force is designed to ensure a sufficient safety factor.

  By applying the present invention to such a part, even if an unexpected external force is generated, the force can be naturally distributed in the clamping direction. Therefore, it is not necessary to select an actuator having a clamping force more than necessary.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. The shapes and combinations of the constituent members shown in the embodiments are merely examples, and various changes can be made based on design requirements and the like.

DESCRIPTION OF SYMBOLS 10 Stopper device 11 Cam groove 11a R shape part 12 Stopper plate 13 Cam roller 14 Cam ring 110 Cam groove

Claims (1)

A stopper plate having a cam groove;
A cam roller that rolls in the cam groove;
A cam ring that engages with and rotates the cam roller to roll the cam roller in the cam groove, and lifts and lowers the stopper plate between a descending end and an ascending end;
Have
The cam groove is provided with an R-shaped portion having a radius equal to or less than the radius of the cam ring, in which the cam roller is disposed when the stopper plate is positioned at the rising end.
When the cam ring stops at a position deviated from the rising end stop position when the stopper plate is positioned at the rising end, the cam ring is rotated by an external force generated on the stopper plate, and the cam ring is stopped at the rising end. Stopper device that moves to a position .

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