Robot arm

Abstract

To easily fill / replace articles even in a narrow space while a restriction by article weight is reduced with respect to a robot arm.SOLUTION: In a robot arm 1A for an inventory management robot which is provided with a hand gripping or suspending an article on an end side and performs pickup / installation / movement of the article while expanding / contracting in a horizontal direction, there are provided: an arm part 10 provided with which frame shape bodies 11, 12, 13, 14 are telescopically stretchable from a body 2; a measuring tape part 5 which houses in a casing 50 a convex tape 51 that is composed of a belt-shaped metal plate bent in a width direction in a measuring tape shape; and a feeding part 7 feeding the convex tape 51 drawn from the measuring tape part 5 with rotation driving means having the electric motor 70. An end side of the convex tape 51 is fixed to an end side of the arm part 10, and the arm part 10 performs expansive operation by driving the feeding part 7 and feeding the convex tape 51.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a robotic arm, and more particularly to a robotic arm suitable for an inventory management robot used for replenishing and replacing articles on a shelf.

Background Art

[0002] When an operator performs a replenishment operation on an article in an inventory and placement location of an article, a replenishment assistance robot that assists in performing the operation efficiently is described in, for example, Japanese Patent Application Laid-Open No. 2033-39081. This robot has a function of reading tags attached to a shelf or an article, and also has a self-running function of automatically moving to the location of the shelf where the article should be replenished while carrying the article based on a replenishment instruction.

[0003] However, although such a replenishment assistance robot has a function of transporting an article to be replenished to a target location, since the loading and unloading operation of the article onto / from the shelf still needs to be performed manually, it is insufficient as an automation means for an inventory management system. On the other hand, Japanese Patent Application Laid-Open No. 2022-8622 proposes an apparatus for automatically picking an article from a containerized storage system, enabling automatic inventory management in units of containers.

[0004] However, in a store handling a variety of products such as a convenience store, when replenishing and replacing products while managing the inventory of products on the shelf, the above-described picking in units of containers cannot handle it. That is, on a shelf where products of various shapes and sizes are arranged side by side and are arranged in series in the front-rear direction for each product, in addition to the narrow vertical width of the shelf, there are many cases where the products in the back of the shelf are taken in and out while passing through the narrow space between adjacent products. Therefore, such work currently relies on manual labor.

[0005] On the other hand, Japanese Patent Application Laid-Open No. 2010-89169 proposes a robot arm that uses the uprightness of a convex tape formed by bending a strip-shaped steel plate in the width direction. The convex tape is formed into a tape measure shape and used as a telescopic arm, and an article at a position horizontally separated is retrieved by a catch (hand) provided on the tip side of the arm, enabling the picking up of an article while passing through a narrow space.

[0006] However, in the case of an arm with a convex tape extended horizontally, the article suspended on the tip side is limited to lightweight ones, and the telescopic distance is also limited to a short range because the supporting force decreases as the arm becomes longer. Therefore, it has to be said that it is functionally insufficient as a robot arm for handling various articles on shelves in a store.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention aims to solve the above problems, and an object of the present invention is to provide a robot arm that can easily replenish and replace articles even in a narrow working space while reducing the limitations due to the weight of the articles.

Means for Solving the Problems

[0009] Therefore, the present invention provides a robot arm for an inventory management robot that is equipped with a hand for gripping or suspending an article at its tip end and performs pick-up, installation, and movement of the article while extending and retracting horizontally. The robot arm includes an arm portion in which arm constituent members are telescopically provided in a telescopic manner from a body fixed to the robot main body side, a tape measure portion in which a convex tape made of a metal plate that is belt-shaped and curved in the width direction is wound around a central axis and housed in a casing in a tape measure shape, and a feeding portion that feeds out the convex tape drawn out from the tape measure portion by a rotational driving means having an electric motor. The tip end side of the convex tape drawn out horizontally is fixed to the arm constituent member that is the tip end portion of the arm portion. The arm portion performs an extension operation by driving the feeding portion manually or / and by a control means to feed out the convex tape.

[0010] In this way, by utilizing the characteristic of the convex tape that the curved portion in the width direction extends in the wound portion and the straight portion is curved in the width direction to maintain the straight state, the tip end side is fixed to the tip end side of the arm portion that telescopically extends and retracts, and the arm portion is extended while feeding out the convex tape by motor drive. Even in a narrow working space such as a store's product shelf or for heavy articles, it becomes possible to easily perform operations by the hand while extending the arm portion to the back of the shelf.

[0011] Further, in this robot arm, the feeding portion has a roller that rotates by motor drive, and the convex tape is fed out by the frictional force between the roller and the convex tape that is in close contact with the outer peripheral surface of the roller and can be oriented. If this is made a feature, the extension operation of the arm portion can be performed accurately and efficiently.

[0012] In this case, if the retraction operation of the arm portion is characterized by being performed by reverse rotation drive of the roller, the extension and retraction operation of the arm portion can be performed with a simple configuration that utilizes the frictional force between the roller and the convex tape.

[0013] Alternatively, if the retraction operation of the arm portion is performed by the winding operation of the convex tape by rotating the central axis of the tape measure portion by a predetermined rotation driving means, even when picking up a relatively heavy article, it is possible to exert a driving force in the retraction direction that exceeds the frictional force between the roller and the convex tape.

[0014] Further, in the robot arm described above, if the feeding portion is provided with means for detecting the extension / retraction amount of the arm portion based on the feeding / rewinding amount of the convex tape by detecting the rotation speed of the roller or the rotation speed of the electric motor, it becomes easy to accurately control the extension / retraction operation of the arm by using the detection data.

[0015] Furthermore, if the above-described robot arm is characterized in that a distance measuring means for measuring the distance between a predetermined position on the robot arm and the article to be operated is provided, it becomes easy to accurately and automatically perform the replenishment / replacement work of the article.

Advantages of the Invention

[0016] According to the present invention in which the arm portion that telescopically extends and retracts is extended while feeding out a convex tape fixed to the tip side by motor drive, it is possible to easily perform the replenishment / replacement of articles even in a narrow working space while reducing the weight limitation.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiment for Carrying out the Invention

[0018] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the present invention, "telescopic" refers to a structure in which overlapping members extend and contract. As such members, in addition to cylindrical ones, frame-shaped and rail-shaped ones are also included.

[0019] Fig. 1(A) shows the state of the robot arm 1A of the present embodiment before extension, Fig. (B) shows the state after extension, and Fig. 2 shows a perspective view of Fig. 1(B). This robot arm 1A is assumed to be used as an arm of an inventory management robot for replenishing and replacing goods on the shelves in a store such as a retail store.

[0020] The robot arm 1A of the present embodiment is mounted on a self-propelled inventory management robot and fixed thereto as means for picking up, installing, and moving goods while horizontally extending and retracting by mounting a hand (not shown) having a function of gripping or suspending an article on the hand mounting body 140 on the tip side.

[0021] The body 2 forming the main body thereof is fixed to the robot body side at the screw hole portions of the legs 101, 102, 103, 104 that are formed in a rectangular shape in plan view and extend downward from the four corners, and four frame-shaped bodies 11, 12, 13, 14 having different widths and serving as arm constituent members are meshed with the rail structure on the inner surface side and the latching structure on the outer surface side in a slidable state to be telescopically provided so as to be extendable and retractable, and the arm portion 10 is provided in a state of protruding from the front end surface of the body 2.

[0022] The body 2 is also provided with a tape measure part 5. The convex tape 51 made of a metal plate that is curved in the width direction in a strip shape on the upper surface plate 2a is wound around the central axis and housed in a casing 50 in a tape measure shape. At the rear end surface, a feeding part 7 is provided as arm driving means composed of an electric motor 70, a gear box 71, and a roller box 72. The convex tape 51 pulled out from the tape measure part 5 is fed out horizontally while changing its direction inside the body 2. The tape measure part 5 has a spring for rewinding and has a function of automatically rewinding the convex tape 51, and a commercially available convex ruler for length measurement can be used as it is.

[0023] The front end side of the convex tape 51 pulled out horizontally is fixed at the central position of the frame body 14 that is the front end part of the arm part 10 in the extended state. By driving the feeding part 7 manually or / and by the control means, the convex tape 51 is fed out in the direction of pushing out the arm part 10, and the arm part 10 performs an extension operation in the range from the state of Fig. 1(A) to the state of Fig. 1(B).

[0024] That is, while utilizing the characteristic of the convex tape that the curved part in the width direction of the wound part extends and becomes flat, and the linear part becomes curved in the width direction to maintain the linear state, the front end side is fixed to the part that becomes the front end side of the arm part 10. While driving the electric motor 70 to feed out the convex tape 51, the arm constituent members of the arm part 10 are sequentially pushed out and extended by the linear part.

[0025] In this way, the robot arm 1A of the present embodiment with a relatively simple configuration can easily perform operations by the hand while extending the arm portion 10 to the back of the shelf between the left and right products even in a situation where the vertical width is narrow, such as a product shelf in a store like a convenience store, and the space for operating the products with various products arranged in the width direction of the shelf is narrow. Moreover, since the arm portion 10 formed by combining the metal frame bodies 11, 12, 13, and 14 has a predetermined level of supporting force due to its robustness, it is possible to operate with a relatively long stroke width while holding a relatively heavy product on the arm tip side.

[0026] Furthermore, as shown in Fig. 3(A), the robot arm 1A of the present embodiment has a roller 720 that rotates by motor drive in the roller box 72 of its feeding portion 7. However, the convex tape 51 pulled out in the direction opposite to the extending direction of the arm portion 10 is reversed while being in close contact with the outer peripheral surface of the roller 720 and its direction can be changed toward the extending direction of the arm portion 10. Due to the frictional force between the outer peripheral surface of the roller 720 and the convex tape 51, the feeding operation of the convex tape 51 is performed.

[0027] Thereby, it is possible to accurately and efficiently perform the extending operation of the arm portion 10 while changing the direction of the convex tape 51 to the extending direction of the arm portion 10. Incidentally, as shown in Fig. 3(B), if a robot arm 1B is provided with pressing rollers 730 and 740 at predetermined positions of the arc-shaped portion where the convex tape 51 is placed on the outer peripheral surface of the roller 720 to increase the adhesion between the convex tape 51 and the roller 720, it becomes easy to perform accurate operations while minimizing the deviation generated between the convex tape 51 and the roller 720 even in a situation where heavy articles with large operating resistance are handled.

[0028] Also, in the robot arm 1A of the present embodiment, the retraction operation of the arm portion 10 is performed by the reverse rotation operation of the roller 720 due to the reverse rotation drive of the electric motor 70. Therefore, the extension and retraction operations of the arm portion 10 can be smoothly performed with only a simple configuration that utilizes the frictional force between the roller 720 and the convex tape 51 described above.

[0029] FIG. 4 shows a robot arm 1C which is a modified example of the above-described robot arm 1A. In this robot arm 1C, the retraction operation of the arm portion 10 is characterized in that the convex tape 51 is wound by rotating a central axis (not shown) of the winding tape portion 5 by a rotation drive means composed of an electric motor 80 and a gear box 81.

[0030] Thereby, even when performing the retraction operation of the arm 10 while supporting an article having a relatively large weight and a large operating resistance, it is possible to exert the expansion and contraction force of the arm portion 10 that exceeds the frictional force between the roller 720 and the convex tape 51, making it easier to ensure an accurate expansion and contraction distance. Further, in this robot arm 1C, a distance sensor 100 that utilizes the reflection of light or sound waves is disposed on the front end side of the upper surface plate 2a of the body 2 as distance measuring means for measuring the distance between the position and the article to be operated, so that it is easy to automatically and accurately perform the replenishment and replacement work while accurately measuring the distance to the article to be operated.

[0031] In addition, in common to the above-described robot arms 1A, 1B, and 1C, if a rotation speed detection means for detecting the rotation speed (including the rotation angle) of the roller 720 or the electric motor 70 is provided in the feeding unit 7 so that the control means can detect the extension and retraction amount of the arm portion 10 based on the feeding and pulling-back amount of the convex tape 51, it becomes easy to realize accurate control in the expansion and contraction operation of the arm portion 10 by using the detection data.

[0032] Also, although illustration is omitted, as a method for detecting the expansion and contraction distance of the arm portion, the length measurement scale pre-displayed on a commercially available convex tape may be directly used, and the distance based on the cumulative count may be calculated while counting the number of times the line or point of the scale passes through with a predetermined sensor.

[0033] As described above, with respect to the robot arm, according to the present invention, even in a narrow working space, replenishment and replacement of articles can be easily performed while reducing the restrictions due to the article weight.

Explanation of Reference Numerals

[0034] 1A, 1B, 1C Robot arm, 2 Body, 5 Tape measure portion, 7 Feeding portion, 10 Arm portion, 11, 12, 13, 14 Frame body, 51 Convex tape, 70, 80 Electric motor, 71, 81 Gear box, 72 Roller box, 720, 730, 740 Roller, 100 Distance sensor

Claims

Claim 1 In a robot arm for inventory management that is equipped with a hand for gripping or suspending an article on the tip side and picks up, installs, and moves the article while extending and retracting horizontally, an arm portion in which arm constituent members are telescopically provided in a telescopic manner from a body fixed to the main body side of the robot, a tape measure portion in which a convex tape made of a metal plate that is band-shaped and curved in the width direction is wound around a central axis and housed in a casing in a tape measure shape, and a feeding portion that feeds out the convex tape drawn out from the tape measure portion by a rotational driving means having an electric motor, wherein the tip side of the convex tape drawn out horizontally is fixed to an arm constituent member that is the tip portion of the arm portion, and the arm portion is caused to perform an extending operation by driving the feeding portion manually or / and by a control means to feed out the convex tape. A robot arm characterized by this. Claim 2 The feeding portion has a roller that rotates by motor drive, and the convex tape is fed out by the frictional force between the convex tape whose orientation can be changed while being in close contact with the outer peripheral surface of the roller. The robot arm according to claim 1, characterized by this. Claim 3 The retracting operation of the arm portion is performed by reversely driving the rotation of the roller. The robot arm according to claim 2, characterized by this. Claim 4 The retracting operation of the arm portion is performed by a winding operation of the convex tape by rotating the central axis of the tape measure portion by a predetermined rotational driving means. The robot arm according to claim 2, characterized by this. Claim 5 The feeding portion is provided with means for detecting the amount of extension and retraction of the arm portion based on the amount of feeding out and pulling back of the convex tape by detecting the rotational speed of the roller or the rotational speed of the electric motor. The robot arm according to claim 2, 3, or 4, characterized by this.

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