JPH0364276B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for gripping an article used for gripping and conveying an article in a robot finger or an automatic assembly system, and in particular, an optical lens used in an optical device. The present invention relates to a method of gripping an article suitable for gripping.

[Problems to be solved by conventional technology and invention]

2. Description of the Related Art Conventionally, various types of article gripping devices for gripping and transporting articles have been known as shown below.

(i) Attach the article using suction power such as vacuum suction.
2. Description of the Related Art There are known article gripping devices that use a so-called suction operation to grip an article and transport the gripped article from a predetermined position to another position or to attach it to another article. As a document disclosing such an article gripping device,
Utility Model Publication No. 54-6949, JP-A-55-150989, JP-A-61-35089, JP-A-62-18317
There are many publications. These publications disclose an article gripping device that directly sucks and holds an article.

(ii) An article gripping device is also known that employs a gripping method in which an article is gripped by a plurality of gripping members and finger members. For example, Japanese Utility Model Publication No. 56-6315 discloses a device in which three claw bodies are connected to a motor through a screw shaft and a bevel gear coupling means, and the motor opens and closes the claw bodies to grip an article. is disclosed. Japanese Patent Publication No. 58-50835 also discloses a device in which three finger members are driven by a motor via gears.

(iii) One of the functions of the gripping device of the present invention is a function of centering the object to be gripped. As an article gripping device equipped with such a centering function,
Publication No. 256004 is known.

(iv) Furthermore, in the prior art, Japanese Patent Laid-Open No. 14500/1983 is known as a mounting head equipped with a suction nozzle and a position regulating claw for regulating the position of an article.

Here, as mentioned above, this invention particularly
This article relates to a method of gripping an article that is suitable only for gripping optical lenses used in optical equipment, etc., and the lens surfaces of such optical lenses must have a high-precision surface finish in order to transmit and refract light beams. Precision and cleanliness are required. As a result, when such an optical lens is incorporated into a lens barrel or optical equipment, when gripping the optical lens, there is a risk of directly touching the optical functional surface and damaging it.
Defacing it is absolutely unacceptable.

For this reason, when assembling an optical lens into a lens barrel, it becomes impossible to grasp the outer peripheral portion of the optical lens from the outside with finger members and fit it into the lens barrel. That is, the inner peripheral surface of the lens barrel and the outer peripheral surface of the optical lens are set to have substantially the same dimensions. Therefore, there is no allowance for gripping the outer periphery of the optical lens from the outside with the finger members, and as a result, the optical lens is inserted into a predetermined position within the lens barrel while the optical lens is gripped. It becomes impossible.

Further, after the optical lens is fitted into the lens locking portion inside the lens barrel, a metal elastic ring or C-ring for fixing the optical lens must be inserted into the lens barrel. Here, the gripping device used to insert these rings into the lens barrel grips the rings from the outside in the radial direction with a plurality of finger members, and the distance between these finger members is adjusted to the outer diameter of the ring in its natural state. The ring is pressed radially inward so as to be slightly smaller than its dimensions, and while the ring is held in this manner, the ring is inserted into the lens barrel into which the optical lens is fitted. Here, in this gripping device, since a pressing force is applied to the ring by the finger members, conversely,
It becomes difficult to remove the ring from the gripping device. As described above, if the ring cannot be removed smoothly from the gripping device, the lens cannot be reliably fixed by the ring, which is a problem.

Specifically, in this method of gripping an article,
If the articles are optical lenses of the same diameter,
As shown in FIG. 2A, first, the magazine stand 2
The lens 120 is placed horizontally on mounting tables 202 and 203 provided on top of the robot hand, and then the suction tube 4 of the robot hand is lowered to a position where it contacts or approaches the lens 120. Finally, the suction tube 4 is placed on the suction tube 4. Vacuum pressure is supplied to attract the lens 120.

However, placing such an optical lens 120 horizontally on the mounting tables 202 and 203 shown in FIG. This can cause scratches, dirt, etc. on the lens. Moreover, such a magazine can only be used for optical lenses of the same diameter.

Therefore, a magazine 100 shown in FIG. 1 is proposed. To explain, on the magazine stand 110 there are mounting stands 101, 102, 103, 10 at equal intervals of 90 degrees.
4 will be erected. This mounting table has an inclined surface 101.
a, 101b; 102a, 102b; 103a,
103b; 104a, 104b are formed respectively, and the optical lens is supported by these inclined surfaces.

By supporting the optical lens in this way, it becomes possible to support optical lenses of various diameters, and the above-mentioned problem of the mounting table coming into contact with the light beam effective surface is eliminated, but there are still problems. Only one is left. That is, FIG. 2B shows the magazine 10 described above.
2 is a front view showing a cross section of the lens 120 placed on the lens 120, but as can be seen from this figure, the lens 120 is not always placed in a horizontal position.
Here, if the optical lens 120 is placed at an angle θ with respect to the horizontal line H, a gap S will be created between the suction surface of the suction tube 4 and the optical lens 120.

Even if vacuum pressure is supplied to the suction tube 4 in this state, the vacuum pressure will leak from this gap S and suction will not be possible. It is also possible to lower the suction tube 4 further and press the optical lens 120 against the mounting tables 102 and 103 with the suction surface of the suction tube 4 to make the optical lens 120 horizontal.
It has been pointed out that the problem is that the effective surface of the light beam is damaged.

This invention was made in view of the above-mentioned problems, and an object of the invention is, for example, when articles of various diameters are placed in one magazine, To provide a gripping method for an article that can securely hold the article in a horizontal state even if the article is not placed in a horizontal state.

[Means for solving problems]

In order to solve the above-mentioned problems and achieve the object, a method for gripping an article according to the present invention includes a method for gripping an article supported by a magazine which is provided with at least three inclined members each having an inclined portion for supporting the article. In a method of at least three or more movable bodies driven by the movable body, and a gripping rod that is slidably provided on each of the movable bodies and is driven up and down by a second driving means, and a small diameter portion and a gripping rod connected to the small diameter portion to support the component. the first drive means, the small diameter portion being between a centering position of the outer surface of the largest diameter within the tolerance of the article and a standby position spaced radially outward therefrom; The robot hand is configured to be driven by a robot hand, which moves the robot hand to a predetermined position on the magazine, moves the small diameter portion of the gripping rod to the centering position of the article, and moves the robot hand to a predetermined position on the magazine. After raising the hand and supporting the article with the inclined portion of the gripping rod, the gripping rod is driven by the second driving means to move the article in parallel to the suction position of the suction tool, and This method of gripping an article is characterized by suction using a suction tool.

[Effect]

In the robot hand configured as described above, an article is first placed on a mounting table on a magazine without paying much attention to its horizontal state.

Next, when the robot hand is transferred to a predetermined position on the magazine, the robot hand starts to descend and stops at a position where the suction surface of the suction tube is a predetermined distance away from the article. Here, at least three moving bodies provided on the robot hand are moved from the standby position to the centering position of the article.
This centering position is a position where the small diameter portion of the gripping rod that is lowered from the movable body is moved to a position that regulates the outer diameter of the article. Next, when the robot hand is lifted, the article is supported by the inclined part or the support part formed between the small diameter part and the large diameter part of the gripping rod, and the robot hand is lifted. When the gripping rod of the article is raised in this manner, the weight of the article itself acts evenly on the inclined portion of the gripping rod, thereby ensuring a parallel state between the article and the suction tube. Here, the gripping rods are each raised by the same amount to move the article to the suction surface of the suction tube. Here, vacuum pressure is supplied to the suction tube to suction the article, and finally, the movable body moves to the standby position to maintain the suction state of the article, and is freely transferred according to the movement of this robot hand. become.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for gripping an article according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a partially sectional external perspective view showing the overall structure of the robot hand 1 and the magazine 100. 1st
In the figure, the structure of the magazine 100 is such that mounting tables 101 and 1 are placed on the magazine table 110 at equal intervals of 90 degrees.
02, 103, and 104 will be erected. This mounting table has inclined surfaces 101a, 101b; 102a, 10
2b; 103a, 103b; 104a, 104b
are formed, respectively, and the optical lens 120 is supported by these inclined surfaces.

By doing so, the optical lens 120 can be supported, optical lenses of various diameters can be supported, and the problem of the mounting table coming into contact with the light beam effective surface is also eliminated.

Next, the robot hand 1 is fixed to a robot arm (not shown) via the hand body 2. This hand body 2 includes a hand member 50;
1; 52 are integrally provided via a relay member (not shown). On the other hand, a drive section 3 is provided below the hand body 2, and a suction tube 4 is provided further below the drive section 3. A vacuum tube 5 is connected to the suction tube 4 to supply vacuum pressure to the suction tube 4.

Threaded rods 9, 10, and 11 are provided from the drive unit 3 at an angle of 120 degrees, respectively, and are rotated a predetermined amount by a drive source within the drive unit 3, and one end of these threaded rods is connected to a bearing of the drive source (not shown). , the other end is supported by bearings of hand members 50; 51; 52.

Outer wall of drive unit 3 and hand member 50; 51; 52
There are guide rods 6a; 6b; 7a; 7b8a;
8b are arranged in parallel to the aforementioned threaded rod. The moving bodies 20; 30; 40 have guide rods 6a; 6b; 7a;
7b8a; While being guided by 8b, the moving body 20;
Female threaded portions (not shown) provided in 30; 40 are engaged with threaded rods 9; 10; It's summery.

The moving body 20; 30; 40 has a gripping rod 21;
1 and 41 are slidably provided, and these gripping rods are stopped at predetermined positions by their own weight. In this stopped state, the inclined portions 21b, 31b, 41b provided on the gripping rods 21, 31, 41 and having the inclination angle α are located on the same horizontal plane. Small diameter portions 21a, 31a, 41 are located above these inclined portions.
a are formed, and these small diameter portions are moved to a position where the outer diameter of the optical lens 120 is restricted during a centering operation to be described later. One end of a gripping rod plate 66; 67 (however, one plate is not shown) is fixed to the upper part 21c; 31c; 41c of these gripping rods, and the other end corresponds to a piston rod 63; 64; It extends to the point where they touch each other.

On the other hand, air cylinders 60; 61; 62 are fixed to the outer walls of the movable bodies 20; 30; 40, and the aforementioned piston rods 63; 64; Tubes 70; 71; 72 are connected to these air cylinders, respectively, so that air pressure is supplied thereto.

The robot hand 1 described above performs predetermined operations by being connected to control/driving means, an air pressure source, a vacuum pressure source, a solenoid valve, etc. (not shown).

The operation of centering, adsorbing, and transferring the optical lens 120 using the robot hand 1 configured as described above is shown in FIGS. 3a to 3f, which are front views for explaining the operations of the magazine and the robot hand.
Explain using.

As shown in FIG. 3a, first, the optical lens 12
0 is the mounting table 101; 102 on the magazine 100;
103; 104 without paying much attention to the horizontal state. Next, when the robot hand 1 is transferred to a predetermined position on _the magazine ₁₀₀ in the direction of arrow The suction surface stops at a position a predetermined distance away from the optical lens. Here, the three moving bodies 20; 30; 40 provided on the robot hand 1 are moved in the directions of arrows _Z1 and _Z2 from the standby position to the centering position of the optical lens.

As shown in FIG. 3c, this centering position refers to the small diameter portions 21a; 31a; 41 of the gripping rods 21; 31;
a is a position where the optical lens is moved to a position that regulates the outer diameter of the optical lens.

Next, when the robot hand 1 is raised in the direction of arrow _Y2 , the inclined part 21b formed between the small diameter part 21a; 31a; ;31b;The optical lens is grasped at 41b and ascends. When the optical lens is held by the inclined part of the gripping rod in this way,
A parallel state with the adsorption tube is now ensured. Next, the gripping rod is raised by the same amount in the directions of arrows W ₁ and W ₂ to move the optical lens shown in FIG. 3e to the suction surface of the suction tube. Here, vacuum pressure is supplied to the suction tube to suction the optical lens. Finally, the moving body moves to the standby position in the directions of arrows Z ₃ and Z ₄ , and the third
As shown in FIG. f, the robot hand is moved freely in _{the two} directions of the arrow X.

FIG. 4 is a flowchart for explaining the operations of the magazine and robot hand shown in FIG. 1, and the operations will be explained based on this figure.

After placing the optical lens in the magazine, the operation begins.

In step S1, the robot hand fixed to the robot arm is transferred to a predetermined position in the magazine where the optical lens is placed. Next, in step S2, the robot hand is lowered to a predetermined position above the optical lens. At this point, the process moves to step S3, and the three moving bodies are moved to the centering position. In step S4, the robot hand is raised, so that the optical lens becomes horizontal due to its own weight. When air pressure is supplied to the air cylinder in step S5,
The piston rod housed in this air cylinder rises and moves the gripping rod plate in contact with the piston rod upward, so that the gripping rod to which this gripping rod plate is connected is raised. When the optical lens is raised to a position where it can be sucked in this way, the gripping rod stops rising. Here, in step S6, vacuum pressure is supplied to the suction tube, and as a result, the optical lens is suctioned. Next, in step S7, the movable bodies are moved away from each other and maintained in an adsorbed state, and the process proceeds to step S8, where they are freely transferred according to the movement of the robot hand, and the operation ends.

As described in detail above, according to the method of holding a circular article according to this embodiment, even if the optical lens 120 as a circular article to be transferred is placed casually in the magazine 100, it will be reliably attracted. I'm trying to get it transferred.

In the embodiment described above, the case where the article is applied to the optical lens 120 has been described, but the present invention is not limited to this and can be applied to any article. To provide a robot hand that is most suitable for centering and suctioning an article placed on a table.

〔effect〕

As described in detail above, according to the present invention, for example, when articles of various diameters are placed in one magazine, even if the articles placed in the magazine are not placed in a horizontal position, the articles can be placed in a horizontal position. Thus, a method for gripping an article that can be reliably attracted to the object is provided.

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional external perspective view showing the overall configuration of an embodiment of the robot hand and magazine according to the present invention; Fig. 2A is a front view showing how a lens is placed on a conventional magazine; Fig. 2B The figure is a front view showing a cross section of a lens placed on the magazine shown in Fig. 1; Figs. 3 a to f are front views for explaining the operation of the magazine and robot hand shown in Fig. 1;
This figure is a flowchart for explaining the operations of the magazine and robot hand shown in FIG. 1. In the figure, 1... robot hand, 2... hand body,
3... Drive unit, 4... Adsorption tube, 5... Vacuum tube, 6
a; 6b; 7a; 7b 8a; 8b...Guide rod, 9;
10; 11... Threaded rod, 20; 30; 40... Moving body, 21; 31; 41... Gripping rod, 50; 51; 5
2... Hand member, 60; 61; 62... Air cylinder, 63; 64; 65... Piston rod, 66; 67
...Gripping rod plate, 70; 71; 72...Tube, 10
0... Magazine, 101; 102; 103; 104
... mounting table, 110 ... magazine table, 120 ... optical lens.

Claims (1)

[Scope of Claims] 1. A method for gripping an article supported by a magazine in which at least three inclined members each having a sloped portion for supporting the article are provided, wherein the inclined member is provided so as to be movable vertically and laterally. a robot hand main body, a first driving means provided on the robot hand main body, a suction tool provided on the robot hand main body, at least three moving bodies driven by the first driving means, and the moving body. A gripping rod that is slidably provided on each of the objects and is driven up and down by a second drive means has a small diameter portion and an inclined portion that is connected to the small diameter portion and supports the component, and the small diameter portion is used to hold the article. centering position of the outer surface of the maximum diameter within the tolerance of
The robot hand is configured to be driven by the first driving means between a standby position spaced radially outward from the robot hand, and the robot hand is transferred to a predetermined position on the magazine, and the robot hand is moved to a predetermined position on the magazine. After moving the small diameter portion of the gripping rod to the centering position of the article and lifting the robot hand to support the article on the inclined portion of the gripping rod, the gripping rod is moved by the second driving means. A method for grasping an article, comprising: driving the article, moving the article in parallel to a suction position of the suction tool, and suctioning the article with the suction tool.