JP3270864B2 - Robot hand - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot hand having a centering function suitable for conveying, for example, a circular article having a center hole.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional example of a robot hand for holding a circular article 30 by holding it. In the example shown in FIG. 6A,
The robot hand has a chuck 33 that is movable in the radial direction, and the chuck 33 is configured to engage with the outer peripheral surface or the outer cylindrical surface 30C of the circular article 30 so that the circular article 30 is held. ing. In the example shown in FIG. 6B, the robot hand has a vacuum chuck 37 having a large number of suction portions 35, and the vacuum chuck 37 engages with the circular surface of the circular article 30, thereby holding the circular article 30. It is configured to be.

[0003] The circular article 30 held by the robot hand is transported to another place or processing section for the next step, and is discharged there. At this time, the circular article 30 may be centered. In other words, the circular article 30 is arranged so that the central axis thereof is aligned with the location of the receiving destination or the predetermined central line of the processed part.

[0004]

In the example shown in FIG. 6A,
Since centering is performed with reference to the outer peripheral surface 30C of the circular article 30, if the circularity of the outer peripheral surface 30C of the circular article 30 is not good, or if the outer peripheral surface 30C is eccentric with respect to the center, accurate You can't get a good heart.

[0005] Further, since the circular article 30 is held by the frictional force between the outer peripheral surface 30C of the circular article 30 and the chuck 33, if the sufficient frictional force cannot be obtained, the circular article 30 is securely held. There was a disadvantage that it could not be retained. For example, in the case of an article made of a material that is easily damaged, such as plastic, or a material that is easily damaged, such as baked goods, it has been difficult to securely grip the article without being damaged by the chuck 33.

Further, the movement of the chuck 33 is usually performed by an actuator such as an air cylinder, and the moving distance until the chuck 33 is engaged with the outer peripheral surface of the circular article 30 and the distance between the chuck 33 and the outer peripheral surface of the circular article 30 are determined. The adjustment of the frictional force during the operation all depended on the operation of the actuator. Generally, it has been difficult to accurately control the working distance of the actuator, and it has been difficult to control the actuator to generate a desired driving force. Therefore, it was difficult to hold the circular article 30 accurately and reliably by the chuck 33.

Thus, in the conventional robot hand, the tact time, that is, the tact time, that is,
There is a disadvantage that the time from when the circular article 30 is held by the chuck 33 to when it is lifted is long.

In the example shown in FIG. 6B, the robot hand has only the function of holding the circular article 30 and does not have the centering function. We needed to have a function. In this example, since the vacuum chuck 37 is used, the circular article 3
No. 0 had to have a flat surface without holes as a suction surface, and other circular articles 30 could not be held.

[0009] In view of the above, an object of the present invention is to provide a robot hand having a simple structure and a centering function.

[0010]

According to the present invention, as shown in FIG. 1, for example, in a robot hand for holding a circular article 30 having a center hole 32, a center having a conical tapered surface 13A at the tip is provided. The member 13 and the claw 17A at the tip
A movable chuck 17 with the outside of the central member 13
The center member 13 is engaged with the center hole 32 from the first surface 30A side of the circular article 30 and the pressing member 21 is positioned on the first surface 30A of the circular article 30.
And the chuck 17 is engaged with the second surface 30B opposite to the first surface 30A of the circular article 30 so that the circular article 30 is held. central axis of the central member 13 is the central axis of the circular article 30 circular article 30 in the course of the tapered surface 13A engages the edge of the center hole 32 is moved in the radial direction from being inserted from the surface 30A side to the center hole 32 It is configured to match.

[0011]

According to the robot hand of the present invention, the pressing member 21 is urged by the spring 23, and the urging force of the spring 23 causes the center member 13 engaged with the center hole 32 of the circular article 30 to move through the center hole 32. It is configured to have a sufficient size for more discharge.

According to the robot hand of the present invention, the chuck 17 includes two chucks and each of the chuck claws 17A has a notch 17E to form a finger for engaging the circular article 30. Is configured.

[0014]

According to the robot hand of the present invention, the center member 3
When the circular article 30 moves in the radial direction while the second tapered surface 13A engages with the edge of the center hole 32 of the circular article 30, the circular article 30 is centered.
Is located at the center hole 32 of the circular article 30 from the first surface 30A side.
And the holding member 21 is on the first surface of the circular article 30.
The chuck 17 engages with the side of the circular article 30A.
Of the circular article 3 by engaging the second surface 30B side of the
0 is retained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 5, the corresponding parts in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 shows an example of a robot hand according to the present invention. The robot hand of the present invention has a housing 11,
The housing 11 has a hole 11 formed along the central axis.
A and a flange portion 11B arranged around the entrance of the hole 11A. The robot hand also has a housing 1
It has a center member or center rod 13 housed in one hole 11A and a chuck portion 17 mounted on a flange portion 11B of the housing 11.

The center rod 13 is movable along the center axis and is urged outward in the center axis direction by a suitable urging means such as a spring 15. The spring 15 is arranged in the hole 11A, and is arranged between the bottom surface of the hole 11A and the inner end surface of the center rod 13.

The columnar tip of the center bar 13 is chamfered, so that the center bar 13 has a circumferential tapered surface 13A. The preferable value of the inclination angle of the tapered surface 13A changes depending on the material of the center rod 13, the material of the circular article 30 held by the robot hand, and the like. The inclination angle of the tapered surface 13A with respect to the central axis is, for example, 10 to 30.
°, for example 20 °. In FIG. 1, the tapered surface 13 </ b> A of the center rod 13 is the center hole 3 of the circular article 30.
2 is shown as being engaged.

The most suitable material for the center rod 13 is selected according to the material for the circular article 30 held by the robot hand. For example, when the circular article 30 is made of ferrite, the center rod 13 may be made of carbide tool steel.

The chuck portion 17 is mounted so as to be movable in the radial direction, and a suitable driving device for moving the chuck portion 17 in the radial direction is provided. Such a drive may be configured to include a slide actuator 19 as shown. Such a slide actuator 19 includes a movable portion 19A formed on the chuck portion 17 and a rail portion or a fixed portion 19B formed on the flange portion 11B of the housing 11, and the movable portion 19A extends radially along the fixed portion 19B. You can move. Such driving devices include fluid actuators such as air cylinders and electromagnetic actuators such as solenoid type cylinders.

The chuck portion 17 has a claw 17A at the tip,
Such a pawl 17A has an engaging surface 17B that engages with the outer circular surface 30B of the circular article 30. Such an engagement surface 17B is preferably perpendicular to the central axis, i.e.
Are arranged in parallel with the outer circular surface 30B. Thus, the engagement surface 17B can come into surface contact with the outer circular surface 30B of the circular article 30.

The robot hand of the present invention further comprises a center rod 1
3 has a pressing member 21 arranged around the periphery of the pressing member 3. The pressing member 21 is movable in the central axis direction, and is urged outward in the axial direction by a suitable urging means such as a spring 23. The spring 23 is arranged in a hole 11C formed in the housing 11, and is arranged between the bottom surface of the hole 11C and the inner end surface of the holding member 21.

The outer end surface of the holding member 21 is
Has an engaging surface 21A that engages with the inner circular surface 30A.
Such an engagement surface 21A is preferably arranged perpendicular to the central axis, that is, parallel to the inner circular surface 30A of the circular article 30. Thus, the engagement surface 21A can come into surface contact with the inner circular surface 30A of the circular article 30.

The pressing member 21 will be described later in detail,
It has a function of pressing the circular article 30 against the engaging surface 17B of the claw 17A and a function of separating the circular article 30 from the center rod 13.

Next, the operation of the robot hand of the present invention will be described with reference to FIGS. As shown in FIG. 2A, the circular article 30 is supported on a
The center protrusion 32A of the support base 34 is inserted and arranged in the center hole 32. In this example, the center projection 3 of the support base 34
The height of 4A is greater than the thickness of the circular article 30, so that the central projection 34A projects outward from the central hole 32.

First, the robot hand is moved in the axial direction so as to be relatively close to the circular article 30. When the height of the center projection 34A of the support base 34 is sufficiently high, first, the circular surface at the tip of the center rod 13 is
, And then the pressing member 21 contacts the inner surface of the circular article 30, that is, the first surface 30A.

The robot hand is moved in the axial direction so as to be relatively closer to the circular article 30. Thereby, the center rod 13 is moved inward against the urging force of the spring 15, and the pressing member 21 is moved inward against the urging force of the spring 23.

Thus, the robot hand has the chuck 1
7 is the outer surface 3 of the circular article 30
It is moved until it is located outside of 0B. In this state, the circular article 30 is sandwiched between the center rod 13, the holding member 21 and the support table 34, and is pressed against the support table 34 by the urging forces of the springs 15 and 23.

Next, as shown in FIG.
Is moved inward in the radial direction, and the claw 17A of the chuck portion 17 is moved.
Is disposed at a position corresponding to the outer side surface 30B of the circular article 30. At this time, the inner surface 17C of the claw 17A of the chuck portion 17 is slightly separated from the circumferential surface 30C of the circular article 30, as shown in the drawing. Therefore, the circular article 30 can freely move in the radial direction while being supported by the pressing member 21. In this state, the robot hand is moved in the opposite direction, that is, in the direction away from the support table 34.

As shown in FIG. 2C, while the robot hand is moved away from the support
13A engages with the edge of the center hole 32 of the circular article 30. At this time, the centering of the circular article 30 is obtained by such engagement. That is, while the center rod 13 is inserted into the center hole 32 of the circular article 30, the eccentrically arranged circular article 30 moves in the radial direction so that the center thereof is aligned with the center axis of the center rod 13. .

Next, the operation of discharging the circular article 30 from the robot hand will be described. When discharging the circular article 30 from the robot hand, the operation is performed in the order shown in FIGS. 3C, 3B, and 3A.

First, a description will be given with reference to FIG. 3C. Cradle 4
The robot hand is arranged so that the center axis of the center rod 13 is aligned with the centering center position of No. 4. The robot hand is moved in the axial direction so as to approach and relatively approach the cradle 44. When the outer surface of the circular article 30, that is, the second surface 30 </ b> B comes into contact with the cradle 44, the movement of the robot hand is stopped.

When the circular article 30 comes into contact with the cradle 44,
The circular article 30, the center rod 13, and the pressing member 21 move inward against the biasing force of the springs 15, 23. The impact between the circular article 30 and the cradle 44 is such that the spring 15,
Since the shock is absorbed by the housing 23, the housing 11 and the like of the robot hand are not damaged by the impact.

Next, the chuck portion 17 is moved radially outward, and the engagement surface 17B of the chuck portion 17 is
More away. The chuck portion 17 is moved until the inner tip of the claw 17A is disposed outside the outer circumferential surface of the circular article 30.

As shown in FIG. 3B, the robot hand is moved in a direction away from the cradle 44 and the circular article 30 placed thereon. Thereby, as shown in FIG. 3A, the center rod 13 is separated from the center hole 32 of the circular article 30. At this time, the engagement between the tapered surface 13A at the tip of the center rod 13 and the edge of the center hole 32 of the circular article 30 may be relatively strong due to the elastic deformation of both. The center rod 13 is separated from the circular article 30 by the biasing force of the biasing spring 23.

Further, the robot hand is moved in a direction away from the circular article 30, and
More away. That is, the pressing member 21 is separated from the inner surface of the circular article 30, that is, the first surface 30A.

The above is the description of the support 3 having the central projection 34A.
A case has been described in which the circular article 30 supported by the holder 4 is held by the robot hand and discharged to the receiving base 44 having no center protrusion 34A. Next, when the surface of the support base 34 is flat or when the height of the central projection 34A is sufficiently low,
The operation of ejecting the circular article 30 supported by the support table 34 while holding it by the robot hand will be described.

First, the operation is performed in the order of the states shown in FIGS. 3A, 3B and 3C. As shown in FIG. 3A, the robot hand is moved in the axial direction so as to be relatively close to the circular article 30.

When the support base 34 is flat or when the center projection 34
When the height of A is low, first, as shown in FIG.
Then, the tapered surface 13A at the tip of the center rod 13 engages with the edge of the center hole 32 of the circular article 30 as shown in FIG.

At this time, the circular article 3
A centering of 0 is obtained. That is, the center bar 13 is
In the process of being inserted into the zero center hole 32, the eccentrically arranged circular article 30 moves radially so that its center is aligned with the center axis of the center rod 13. Next, the chuck unit 17
Is moved inward in the radial direction, and the robot hand is further moved in the opposite direction, that is, in a direction away from the support table 34.

In the present embodiment, as described above, the chuck 17
Is moved inward or outward in the radial direction, but it is not necessary to precisely control the moving distance or position of the chuck portion 17. For example, a predetermined gap is always formed between the inner surface 17C of the claw 17A and the outer cylindrical surface 30C of the circular article 30, and they do not come into contact with each other.

FIG. 4 shows an example of the chuck section 17 used in the robot hand of the present invention. The chuck portion 17 may be configured to include a plurality of portions, for example, two portions as illustrated. The two chuck parts 17 are circular articles 30
Are movably arranged in the radial direction so as to be sandwiched from both sides. The claw 17A of the chuck 17 has a notch 1
7E may be configured to form two fingers.

When the chuck portion 17 moves inward in the radial direction, the chuck portion 17 can be moved until the notch portion 17E engages with the support base 34. The moving process becomes longer, and the circular article 30 can be more reliably held by the claws 17A of the chuck portion 17.

FIG. 5 shows an example of a charging and discharging machine in which the robot hand of the present invention is used. Such a loading / unloading machine is configured to charge an unfinished circular article, and after various processes, discharge the completed circular article.

The loading / unloading machine includes a loading tray 41 for receiving an unfinished circular article, a transfer robot hand 43 for carrying out all the transport of the circular article, and a rotation for positioning the unfinished circular article in the rotational direction (not centering). Direction positioning unit 45, backup unit 47, pallet 49, robot hand 51 of the present invention for centering and positioning an unfinished circular article, conveyor 53 for transporting the circular article to various processes, and discharging for storing the completed circular article. It includes a tray 55, a tray changer 59 for exchanging an empty tray and a tray on which circular articles are placed.

Backup unit 47, pallet 49
The reason why two robot hands 51 are provided and four rotation direction positioning units 45 are provided is to shorten the tact time of one circular article. The circular article conveyed by the conveyor 53 in the direction of the arrow shown in the drawing is completed through various processes, and returns to the backup unit 47. The pallet 49 is supported by the backup unit 47, and the finished product is discharged from the pallet 49 to the discharge tray 55.

Although the embodiments of the present invention have been described in detail, it will be apparent to those skilled in the art that the present invention is not limited to the above-described embodiments and can adopt various other configurations without departing from the gist of the present invention. It will be easily understood.

[0048]

According to the present invention, not only the circular article 30 can be held and transported, but also the circular article 30 can be centered at the same time, and a robot hand having a simple structure can be provided. Has advantages.

According to the present invention, since the centering is performed based on the center hole of the circular article 30, the roundness of the outer peripheral surface of the circular article 30 is not good, or the outer peripheral surface is eccentric with respect to the center. There is an advantage that accurate centering can be obtained even if the

According to the present invention, instead of holding the circular article 30 by the frictional force between the outer peripheral surface of the circular article 30 and the chuck 33, the circular article 30 There is an advantage that it can be reliably held by the urging forces of the springs 15 and 23 between the claws 17A.

According to the present invention, in the case of an article made of a fragile material such as a plastic or a fragile material such as a baked product, there is an advantage that the article can be securely gripped by the chuck 33 without being damaged. .

According to the present invention, there is no need to precisely control the working distance of the actuator, and it is not necessary to precisely control the driving force of the actuator. Therefore, the driving device for the robot hand has a simple structure. There are advantages that can be.

According to the present invention, there is an advantage that the tact time, that is, the time from when the circular article 30 is held by the chuck 33 to when the circular article 30 is lifted, is shortened in order to securely hold the circular article 30.

According to the present invention, since the vacuum chuck 37 is not used, there is an advantage that the circular article 30 of any shape can be held as long as it has a center hole.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a robot hand according to the present invention.

FIG. 2 is an explanatory diagram illustrating an operation of the robot hand according to the present invention.

FIG. 3 is an explanatory diagram illustrating an operation of the robot hand of the present invention.

FIG. 4 is a diagram illustrating a configuration example of a chuck unit of the robot hand according to the present invention.

FIG. 5 is a diagram showing an example of a loading / unloading machine using the robot hand of the present invention.

FIG. 6 is an explanatory diagram illustrating a configuration example and operation of a conventional robot hand.

[Explanation of symbols]

 Reference Signs List 11 housing 11A hole 11B flange portion 11C hole 13 center rod 13A taper surface 15 spring 17 chuck portion 17A claw 17B engagement surface 17C inner surface 19 slide actuator 19A movable portion 19B fixing portion 21 pressing member 21A engagement surface 23 spring 30 circular article 30A inner circular surface 30B outer circular surface 30C outer cylindrical surface 32 hole 34 support base 34A central projection 35 suction unit 37 vacuum chuck 44 receiving base

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-256004 (JP, A) JP-A-56-107894 (JP, A) Fully open Showa 60-80891 (JP, U) Really open 87530 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B25J 15/00 B25J 15/08

Claims (3)

(57) [Claims] 1. A robot hand for holding a circular article having a center hole, comprising: a center member having a conical tapered surface at a tip, a movable chuck having a claw at a tip, and an outer side of the center member.
A holding member to be placed, wherein the center member is engaged with the center hole from a first surface side of the circular article, and the holding member is a first member of the circular article.
And the chuck engages a first surface of the circular article.
The circular article is held by engaging a second surface opposite to the surface of the circular article, and the center member is a first member of the circular article.
The circular article is moved in the radial direction during the process in which the tapered surface is engaged with the edge of the central hole after being inserted into the central hole from the side of the circular hole, and the central axis of the circular article is the central axis of the central member. A robot hand characterized in that it is configured to match with. 2. The robot hand according to claim 1 , wherein the pressing member is urged by a spring, and the urging force of the spring moves the center member engaged with the center hole of the circular article from the center hole. A robot hand configured to have a sufficient size for discharging. 3. A robot hand according to claim 1 or 2, wherein said chuck comprises two chucks, each of the claw of the chuck notches to form a finger for engaging in the circular article A robot hand configured to have a part.