KR0183709B1 - Apparatus of robot hand - Google Patents

Abstract

The present invention relates to a robot hand device. According to the invention, the drive means 22, the outer cover 51 supporting the rotary shaft 31, the movable member 28 which can reciprocate by the drive means 22, the movable member 28 A first link member 23 rotatably connected to both sides of the c), one end rotatably connected to the first link member 23, and another end rotatably connected to the rotation shaft 31. A robot hand comprising a two link member 24 and an extension of a connector 32-finger 21 rotatably connected to the rotating shaft 31 while maintaining a predetermined angle with the second link member 24. Apparatus 20 is provided. The robot hand device of the present invention not only reduces the overall weight but also can exhibit a relatively large output, thereby achieving an effect of maximizing operation efficiency with miniaturization / light weight of the device.

Description

Robot hand device

1 is a perspective view of a robot hand device according to the prior art.

2 is a front view of the robot hand apparatus according to the present invention, which is shown by removing the cover with the fingers spaced apart.

3 shows the robot hand device of FIG. 2 with the fingers in close proximity.

4 is a perspective view of the connector and finger extension of the robot hand device of FIG.

FIG. 5 is a front view showing the robot hand device of FIG. 2 in partial cross section in a cover assembled state. FIG.

* Explanation of symbols for main parts of the drawings

10: robot hand device (prior art) 13: servo motor

15: gear 16: finger

17: fixed jig 18: second shaft

20: robot hand device (present invention) 22: linear motor

21: finger 23: first link member

24: second link member 28: moving plate

The present invention relates to a robot hand apparatus using a link mechanism, and more particularly, to a robot hand apparatus capable of holding a workpiece by using a linear motor and a plurality of link mechanisms.

The robot hand is a device for holding the workpiece so that the workpiece can be moved from the current position to another position. The robot hand should be designed in consideration of the size, shape, weight, and working conditions of the workpiece. The present invention relates, in particular, to a robot hand for handling cassettes of wafers used in semiconductor manufacturing processes, which can be used in clean rooms.

1 is a schematic cutaway perspective view of the robot hand device 10 according to the prior art. The robot hand device 10 includes an AC servo motor 13 and a shaft-gear mechanism disposed in the upper cover 11 and the lower cover 12 and a finger portion 16 disposed outside the cover. The AC servo motor 13 and the first shaft 14 are rotatably fixed to the fixing jig 17 disposed inside the cover, and the power generated from the shaft of the motor is transmitted to the first shaft 14 as a gear. do. The finger 16 disposed outside the cover is a U-shaped member and includes a second shaft 18 at the top thereof, and the second shaft 18 is rotatably held by the bearing through the lower cover 12. . Gears are installed on the second shaft 18 passing through the inner side of the lower cover 12, which meshes with worm gears 19 installed on the first shaft 14 to direct the power of the motor to the fingers 16. To pass. The teeth of the worm gear 19 arranged on the left and right sides are formed in opposite directions to each other.

As can be seen in FIG. 1, as the motor rotates, the finger 16 can rotate the second shaft 18 around the rotation axis. Since the teeth of the left and right worm gears 19 are formed in opposite directions, the fingers 16 approach each other as the first shaft 14 rotates in one direction, and the work objects are gripped by being spaced apart from each other. The workpiece may be separated from the finger.

In the robot according to the prior art as described above, the AC servo motor is used as a driving source, and a method of transmitting the motion of the servo motor to the worm gear is adopted. There are several problems with this approach, which is summarized as follows. First, since the AC servo motor has a relatively large weight, the overall robot weight tends to increase. Second, since the cable for controlling the servo motor is included in several strands, the device is not simplified, and the motor control is complicated. Third, the backlash occurs due to the use of the worm gear, so that play occurs in the operation of the robot hand. The above-mentioned problems have a negative effect on the smooth operation of the robot, and there are considerable difficulties in correcting the malfunctions if they occur.

An object of the present invention is to provide a compact and lightweight robot hand apparatus using a linear motor and a link mechanism by excluding the AC servo motor and worm gear, which have been employed in the prior art, to improve the above problems from the hand apparatus.

Another object of the present invention is to provide a reliable robot hand device which can prevent the opening of the robot hand by any external force without extra power when the object is caught by using the structural features of the link mechanism.

It is another object of the present invention to provide a robot hand device that can provide a linear motor and sensor means to the device to ensure accuracy in the operation of the robot hand, pursue convenience of control, and prevent malfunction.

In order to achieve the above object, according to the present invention, a drive means, an outer cover for supporting a rotating shaft, a movable member capable of reciprocating by the driving means, a first link rotatably connected to both sides of the movable member A second link member having a member, one end rotatably connected to the first link member, and another end rotatably connected to the rotation shaft, and the rotation shaft while maintaining a predetermined angle with the second link member. Provided is a robot hand device comprising an extension of a connector-finger rotatably connected to a finger.

According to a feature of the invention, the movable member reciprocates between an upper member and a lower member, a sensor dock is installed on the movable member, and a limit sensor is installed on the upper member and the lower member.

According to another feature of the invention, the support member is provided between the upper member and the lower member, the through member is formed in the through hole for passing the support member is free to move up and down.

According to another feature of the invention, it has a link mechanism structure that reduces driving force and is capable of coping with external forces.

According to another feature of the invention, the extension of the connector-finger is formed by coupling the protrusion formed in the connector to the assembly groove formed in the finger in a mutually fitting manner, the connector and the finger is provided with a passage for the cable to the bottom of the finger It communicates with the sensor receiving portion formed in the cable does not protrude outward.

According to a feature of the invention, the drive means is a linear step motor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 shows the main part of the robot hand device 20 according to the present invention with the outer cover removed, and the fingers 21 are shown in a spaced apart state (i.e., with the workpiece separated from the hand device). have. This device is of a different configuration than the device of FIG. 1 because the robot hand device operates via a link mechanism.

The robot hand device 20 according to the present invention includes a link mechanism composed of a linear step motor 22 and a plurality of link members 23 and 24. The linear step motor 22 is provided at the bottom of the lower frame 25, and the lower frame 25 is connected to the upper frame 26 by side plates 27 provided on the left and right sides. A moving plate 28 is provided between the upper frame 26 and the lower frame 25, which is connected to the end of the shaft 29 of the linear step motor 22 so that the motor shaft 29 reciprocates up and down. As you get up and down. The supporting member 30 is provided between the upper frame 26 and the lower frame 25, and two moving holes are formed in the moving plate 28, through which the supporting member 30 is inserted. Thus, the movable plate 28 moves up and down while the support member 30 is inserted into the through hole, and the shaft end 29 of the linear step motor is coupled to the connector provided at the bottom of the movable plate 28 to thereby move the movable plate 28. (28) transmits a driving force that can raise or lower.

The upper frame 26 and the lower frame 25 are provided with limit sensors (not shown). The limit sensors are for detecting the movement of the moving plate 28 upward or downward by the motor shaft 29 to reach the upper frame 26 or the lower frame 25, and the upper surface of the moving plate and It is associated with a sensor dog provided on the bottom. In the operation of the robot hand, when the moving plate 28 is detected by the sensor of the lower frame 25, if necessary, the linear step motor 22 is operated by an external signal to move the moving plate 28 upward, When the moving plate 28 is detected by the sensor of the upper frame 26, the operation of the linear step motor 22 is stopped.

In the figure, first link members 23 are provided on the left and right sides of the movable plate 28. Since the first link member 23 is rotatably held on the small bearing provided on the movable plate 28, the movable plate 28 can be displaced at a predetermined angle as the movable plate 28 moves up and down. The second link member 24 is connected to the first link member 23 on the opposite side of the point where the first link member 23 and the moving plate 28 are connected, and they are connected to be rotatable on a small bearing. . The weight of the first link member 23 and the second link member 24 is preferably as light as possible for smooth operation of the robot hand. In the preferred embodiment, an aluminum material is used, and an elliptical space is formed in the center portion of the link to significantly reduce the weight.

On the opposite side of the point where the second link member 23 is connected to the first link member 24, the second link member 24 is rotatably connected with respect to the rotary shaft 31. The rotary shaft 31 is supported by a bearing 52 provided inside the outer cover 51 as shown in FIG. The connector 32 is rotatably connected to the rotating shaft 31, and the connector 32 is again connected to the finger 21 as shown in FIG. 4. The tenon of the connector 32 and the finger 21 may rotate about the rotation shaft 31. Since the second link member 24 and the connector-finger extension portions 32 and 21 rotate about the rotation shaft 31 while maintaining a fixed angle therebetween, the second link member 24 is connected to the first link member ( When displaced by 23, the finger 21 also rotates about the rotary shaft 31.

4 shows the extension of the connector 32 and the finger 21. The connector 32 is formed with a shaft hole 33 into which the rotary shaft 31 is inserted, and a hole through which the cable passes. The connector 32 is provided with a protrusion 35 to be inserted into the assembly groove 34 formed in the finger 21. (In the drawing, the assembly groove 34 and the protrusion 35 are shown assembled). Finger 21 is preferably made of a plastic product to reduce the moment of inertia as much as possible, has an assembly groove 34 corresponding to the protrusion 35 of the connector 32 is assembled in a mutual fit manner . The cable passage 36 is formed inside the finger 21. The cable is intended to be connected to a sensor housed in the sensor accommodating portion 37 formed at the bottom of the finger 21, and the sensor is used to detect whether or not the workpiece is held by the finger 21 of the robot. Robots operating in the clean room should avoid environmental elements that may generate dust as much as possible. Thus, embedding the sensor cable in the cable passage 36 formed in the finger 21 satisfies the clean room clean conditions. Let's do it. The cable passage 36 formed in the finger 21 communicates with the cable passage formed in the connector 32. An insertion groove 38 may be provided on the lower inner surface of the finger to hold the workpiece, and the embodiment illustrated in the drawing illustrates the insertion groove 38 for holding the wafer cassette.

Referring again to FIG. 3, there is shown a state in which the robot hand device 20 of FIG. 2 grips a workpiece. Operation of the linear step motor 22 causes the moving plate 28 to approach the lower frame 25 so that the first link member 23 associated with the moving plate 28 is positioned on the horizontal line with the moving plate 28. do. Accordingly, the second link member 24 rotatably connected to the first link member 23 rotates about the rotation shaft 31. As described above, since the connector-finger extensions 32 and 21 maintain a predetermined angle of the second link member 24, the finger 21 moves toward the center of the device as the second link member 24 rotates. The workpiece can be gripped in close proximity.

Figure 5 shows the robot hand device according to the invention installed in the outer cover 51 in a partially cut state. As described above, the rotary shaft 31 is held on a bearing installed in the cover 51, and the finger sensor cable c is connected to the finger 21 through a passage formed in the connector 32 and the finger 21. Extends downward. It is preferable that the cable c associated with the linear step motor 22 is also incorporated in the cover 51 of the motor to satisfy the conditions of the clean room. As shown in the figure, the portion of the finger 21 that grips the work object has a wide inlet of the gripping groove 38 to facilitate insertion.

The robot hand device according to the present invention uses a small, light weight linear step motor compared to the prior art devices, so that not only the overall weight can be reduced but also a relatively large output can be achieved, thereby minimizing / lightening the device and maximizing operation efficiency. Effect was achieved.

In addition, by adopting a link mechanism that can fundamentally improve the work error caused by the backlash caused by the existing device using the gear to achieve the accurate and reliable operation of the device. Incidentally, the use of a linear step motor and a sensor without using a servo motor not only simplifies the control, but also minimizes the use of cables to provide a device capable of meeting the clean condition.

Although the present invention has been described with reference to one embodiment shown in the drawings, those skilled in the art will understand that various modifications are possible therefrom. Therefore, the true scope of the invention should be defined by the appended claims.

Claims (3)

A linear step motor 22 for reciprocating the shaft 29, an outer cover 51 for supporting the rotary shaft 31, and fixed to an end portion of the shaft 29 of the driving means 22, which can reciprocate. A movable member 28, a first link member 23 rotatably connected to both sides of the movable member 28, an end portion rotatably connected to the first link member 23, and the rotary shaft 31; A second link member 24 having the other end rotatably connected to the connector, a connector 32 rotatably connected to the rotation shaft 31 while maintaining a predetermined angle with the second link member 24. An extension of the 21 and a sensor dock provided on the movable member 28 so as to limit the reciprocating motion of the movable member 28 between the upper member 26 and the lower member 25, and Robot hand device (20) comprising a limit sensor provided on the upper member (26) and the lower member (25), respectively. The method of claim 1, wherein the support member 30 is installed between the upper member 26 and the lower member 25, the moving member 28 is formed with a through hole for passing the support member 30 Robot hand device, characterized in that. The method of claim 1, wherein the extension of the connector (32) -finger (21) is formed by coupling the protrusions (35) formed in the connector (32) to the assembly groove (35) formed in the finger 21 in a mutually fitting manner. And a connector (32) and a finger (21) are provided with a cable passageway (36) to communicate with the sensor receiving portion (37) formed at the lower end of the finger (21).