JPH0615586A - Attitude holding mechanism of conveyor - Google Patents

Abstract

PURPOSE:To provide an attitude holding mechanism that is able to surely keep off the inclination of a conveyor. CONSTITUTION:An attitude holding mechanism 10 is composed of comprising a symmetrical pair of guide rollers 12 being installed in a conveyor 1 traveling along a rail 2 and an attitude holding plate 11 being tightly installed in such other than this conveyor 1 and receiving the paired guide rollers 12. According to this method, even if offset load acts on the conveyor 1, since the guide rollers 12 constituting the attitude holding mechanism 10 comes into contact with the attitude holding plate 11, a moment being produced by this offset load is offset by another moment being produced by a reaction receiving from the attitude holding plate 11 by the guide rollers 12, thus an inclination in the conveyor 1 is surely prevented from occurring and its position is kept constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a posture holding mechanism for preventing a conveying device from tilting.

[0002]

2. Description of the Related Art An example of a carrier device 1 is shown in FIG. 8. The carrier device 1 is a main body (carriage train) 5 which is self-propelled along a rail 2.
For example, a robot arm 7 is attached to the lower part of the.

Then, the transfer device 1 moves to a predetermined position along the rail 2, where the robot arm 7 is driven to perform a predetermined working operation with the tool 8 attached to the end thereof. .

[0004]

Therefore, in such a transfer device 1, the load of the robot arm 7 offset from the center of the rail 2 acts on the main body 5 as shown in FIG. A large counterclockwise moment is generated as a whole, and accordingly, the rail 2 is twisted and the side rollers 6 are deformed and deformed, and the rails 2 and the side rollers 6 are conveyed due to the clearance between them. The entire device 1 is tilted by an angle θ as shown by the chain line in FIG. Then, when the carrier device 1 is tilted in this way, the distance H from the rail 2 of the tool 8 which is the working unit as shown in the figure.
When is particularly large, an error corresponding to L shown in the figure occurs at the position of the tool 8, which causes a problem that high-precision machining using the tool 8 cannot be performed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an attitude holding mechanism for a carrying device which can surely prevent the carrying device from tilting.

[0006]

In order to achieve the above object, the present invention is directed to a posture holding means provided on a conveying device that travels along a rail, and a posture fixed to a portion other than the conveying device to receive the posture holding means. It is characterized in that it includes a holding plate to form a posture holding mechanism of the carrying device.

[0007]

According to the present invention, even if an offset load is applied to the main body of the transport apparatus (transport train), the posture holding means constituting the posture holding mechanism is in contact with the posture holding plate, so that the offset load is generated. The moment is offset by the moment generated by the reaction force that the posture maintaining means receives from the posture maintaining plate, and the inclination of the conveying device is reliably prevented, and the posture is kept constant.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a front view of a conveying device 1 showing a first embodiment of the present invention. In FIG. 1, reference numeral 2 is a rail which is long in the direction perpendicular to the plane of the drawing and which has a plurality of L-shaped stays 3 interposed therebetween. Supported by the ceiling 4.

The main body (conveyor train) 5 of the carrier device 1 is movably supported on the rail 2, and a drive motor (not shown) as a drive source is built in the main body 5. A plurality of side rollers 6 rolling on the side surface of the rail 1 are provided on the upper and lower sides of the main body 5 and on the left and right sides of the front and rear sides (front and rear with respect to the traveling direction of the transport device 1) of the main body 5.
Is attached.

A robot arm 7 is attached to the lower part of the apparatus main body 5, and a tool 8 as a working unit is attached to the tip of the robot arm 7.

The structure of the robot arm 7 will be described with reference to FIG.

The robot arm 7 has an X-axis arm 111 and a Y-axis arm 112 which are connected to each other by a Y-axis and rotate in a horizontal plane. The X-axis arm 111 is the X-axis motor 1.
It is driven by 3 and rotates within a predetermined angle range in the horizontal plane about the X axis shown in the drawing. Further, the Y-axis arm 112 is driven by the Y-axis motor 14 and rotates about the Y-axis shown in the drawing within a predetermined angle range within a horizontal plane.

On the other hand, in FIG. 2, reference numerals 15 and 16 are first and second parts which are connected to each other by a pivot shaft 17 and rotate in a vertical plane.
As shown in the drawing, the end of the first arm 15 is pivotally connected to the tip of the Y-axis arm 112 by a pivot shaft 18 as shown in the figure. A tool plate 19 is rotatably connected to a free end of the second arm 16 by a pivot shaft 120, and the tool 8 is attached to the tool plate 19. The pivot shaft 17 rotates with the second arm 16, the pivot shaft 18 rotates with the first arm 15, and the pivot shaft 120 rotates with the tool plate 19 and the tool 8.

A ball screw mechanism 30 which is an actuator is built in the Y-axis arm 112. The ball screw mechanism 30 includes a ball screw 31 rotatably arranged in the length direction of the Y-axis arm 112. The ball screw 31 includes a slider 32 that is screwed forward and backward, and a drive motor 33 that rotationally drives the ball screw 31.

One end of a drive bar 34 is rotatably attached to the slider 32 of the ball screw mechanism 30 by a shaft 35, and the other end of the drive bar 34 is attached to the first arm 15. A shaft 36 is pivotally attached to the intermediate portion so as to be rotatable.

Further, the first and second arms 15 and 16 have a transmission mechanism 40 for transmitting the rotation of the first arm 15 to the second arm 16, the tool plate 19 and the tool 8.
Posture holding mechanism 5 for keeping the posture of the player always vertical
0 is provided.

Here, the structure of the transmission mechanism 40 will be described. The transmission mechanism 40 is rotatably supported by the end portion of the first arm 15 on the side of the second arm 16 and has different sizes.
1, 42 and a small diameter gear 43 connected to the pivot shaft 18. The gears 41, 42, 43 mesh with each other, and the large-diameter gear 41 and the small-diameter gears 42, 4
The gear ratio with 3 is set to 2: 1.

Arms 44 and 45 are connected to the pivot shaft 18 and the gear 41, respectively.
4, 45 are connected by a link bar 46.

Next, the structure of the posture holding mechanism 50 will be described.

That is, in the posture holding mechanism 50, 5
Reference numerals 1 and 52 denote arms connected to the pivot shafts 17 and 120, respectively. The arms 44 and 51 are connected by a first attitude link 53, and the arms 51 and 52 are connected by a second attitude link 54. It is connected.

By the way, in this embodiment, the posture holding mechanism 10 for keeping the posture of the carrying device 1 constant is provided. The posture holding mechanism 10 is provided on the lower surface of the horizontal portion of the L-shaped stay 3. The posture holding plate 11 is mounted vertically in parallel with the rail 2, and a pair of left and right guide rollers 12 rotatably provided on the side of the main body 5 of the transporting device 1 are included. 12 is the posture holding plate 1
1 is rotatably abutted on both sides so as to sandwich 1.

The carrier device 1 is driven by the drive motor and self-propelled to a predetermined place on the rail 2 while being guided by the side rollers 6 on the left and right sides thereof. Robot arm 7
1 is largely projected to one side (left in the illustrated example) as shown in FIG. 1, the load (self-weight) of the robot arm 7 is largely offset from the center of the rail 2 and the apparatus main body 3 is This offset load acts. Here, if the center of gravity G of the robot arm 7 is at a position separated from the center of the rail 2 by L1 as shown in the figure, the counterclockwise moment M1 = F due to the load F of the robot arm 7 acting on this center of gravity G. XL1 is generated, and the moment M1 tends to tilt the transport device 1 counterclockwise.

However, in this embodiment, the posture holding mechanism 1 is used.
Since the guide roller 12 at 0 is in contact with the posture holding plate 11 as described above, the inclination of the transport device 1 is prevented. That is, at this time, the attitude holding plate 11 is attached to the guide roller 1
2 (left guide roller 12 in FIG. 1) receives a reaction force R received from the posture holding plate 11, and if the distance from the center of the rail 2 at the point of application of this reaction force R is L2 as shown in the figure, the conveyance device 1 has a clockwise moment M2 = R × L
2 occurs, and the counterclockwise moment M1 is canceled by this moment M2. Actually, the posture holding plate 11 has a reaction force R = F × L1 / L2 having a magnitude such that the moments M1 and M2 are equal (M1 = M2).
Occurs.

Therefore, according to the present embodiment, the moment M1 for inclining the conveying device 1 is canceled by the moment M2 generated by the attitude holding mechanism 10, so that an unreasonable force acts on the rail 2 and the side rollers 6. Therefore, the inclination of the conveying device 1 due to the twisting of the rail 2 and the bending deformation of the side roller 6 is reliably prevented, and the posture of the conveying device 1 is always kept constant. In the case of the present embodiment, if the tilt of the transfer device 1 is prevented, no error occurs in the position of the tool 8 attached to the tip of the robot arm 7, and high-precision machining with the tool 8 is possible. Become.

Next, a second embodiment of the present invention will be described with reference to FIG. Incidentally, FIG. 3 is a front view of a carrying device showing a second embodiment of the present invention. In this figure, the same elements as those shown in FIG. 1 are designated by the same reference numerals, and their explanation will be given below. Omit it.

In this embodiment, the posture holding plate 11 constituting the posture holding mechanism 10 is attached to the ceiling 4 as shown in the drawing, and the guide rollers 12 provided on the left and right of the upper portion of the main body 5 of the conveying apparatus 1.
Is rotatably brought into contact with the posture holding plate 11.

Thus, also in this embodiment, even if the moment M1 = F × L1 that tries to tilt the carrying device 1 in the counterclockwise direction due to the offset load F of the robot arm 7, the posture holding mechanism 10 is generated. Since the guide roller 12 of FIG.
(To the right of) the clockwise moment M2 = R × L2 based on the reaction force R that the guide roller 12 receives from the posture holding plate 11.
Occurs, which cancels the counterclockwise moment M1. Therefore, also in this embodiment, the posture holding mechanism 1
With 0, the inclination of the carrier device 1 is prevented, and its posture is always kept constant.

By the way, in the above first and second embodiments, since the cost is increased if the posture holding plate 11 is provided over the entire route, it may be considered that the posture holding plate 11 is provided only at the work station.

However, if the posture holding plate 11 is provided only in the work station, a problem occurs that a shock occurs when the guide roller 12 starts to contact the posture holding plate 11 in the work station.

Therefore, examples of the posture holding mechanism 10 which solves the above problems are shown in FIGS. 4 to 7, respectively. 4 to 7, the same elements as those shown in FIG. 1 are designated by the same reference numerals.

In the third embodiment shown in FIG. 4, the guide roller 12 in the first embodiment is constructed so as to be able to come in contact with and separate from the attitude holding plate 11, and it is not necessary to hold the attitude when the transport device 1 is running. In this case, the robot arms 7 are separated from each other as shown by the solid line in the figure, and when the robot arm 7 performs work at the work station, the actuator (not shown) moves the guide roller 12 in the direction of the arrow shown in FIG. The plate 11 is clamped.

Further, in the fourth embodiment shown in FIG. 5, the second
The guide roller in the embodiment is configured to be tiltable, and when it is not necessary to maintain the posture of the conveyance device 1, the guide roller 12 is horizontally tilted as shown by a chain line in FIG. The guide roller 12 is erected by an actuator (not shown) as shown by the solid line in FIG. 5, and is brought into contact with the posture holding plate 11.

Thus, according to the above third and fourth embodiments, the guide roller 12 contacts the posture holding plate 11 after the transport device 1 reaches the work station where the posture holding plate 11 is installed. Since they are in contact with each other, the problem of the impact does not occur, and the posture holding plate 11 is partially provided only in the work station, so that the cost can be reduced.

Further, in the fifth embodiment shown in FIGS. 6 and 7, an electric slide unit 20 is provided in the main body 5 of the carrying device 1, and the posture holding plate 11 having an L-shaped cross section is provided on the stay 3 side.
Is provided.

As shown in detail in FIG. 7, the electric slide unit 20 has a hanger 21 that moves back and forth in the direction of the arrow shown in the drawing to engage and disengage with the posture holding plate 11. When traveling, the hanger 21 of the electric slide unit 20 is retracted and separated from the posture holding plate 11 as shown by the solid line in FIG.

When the carrying device 1 reaches the work station, the electric slide unit 20 is driven and the hanger 21 of the electric slide unit 20 extends and fits on the posture holding plate 11 as shown by the chain line in FIG. Therefore, also in this embodiment, the same effect as that obtained in the third and fourth embodiments can be obtained. In this embodiment, an interlock is provided so that the transport device 1 can travel only when the hanger 21 of the electric slide unit 20 is retracted.

[0038]

As is apparent from the above description, according to the present invention, the posture holding means provided in the conveying device that travels along the rail, and the posture that is fixedly provided to other than the conveying device and receives the posture holding means. Since the posture holding mechanism of the carrying device is configured to include the holding plate, it is possible to obtain an effect that the tilt of the carrying device is reliably prevented and the posture of the carrying device can be kept constant.

[Brief description of drawings]

FIG. 1 is a front view of a carrying device according to a first embodiment of the present invention.

FIG. 2 is a front view of a transfer device showing a configuration of a robot arm.

FIG. 3 is a front view of a carrying device according to a second embodiment of the present invention.

FIG. 4 is a front view of a carrying device according to a third embodiment of the present invention.

FIG. 5 is a front view of a carrying device according to a fourth embodiment of the present invention.

FIG. 6 is a partial front view of a carrying device according to a fifth embodiment of the present invention.

FIG. 7 is a detailed view of an electric slide unit.

FIG. 8 is a front view of a transfer device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transport device 2 Rail 10 Posture holding mechanism 11 Posture holding plate 12 Guide roller (posture holding means) 20 Electric slide unit 21 Hanger (posture holding means)

Claims (1)

[Claims] 1. A conveyance comprising a posture holding means provided on a conveying device traveling along a rail, and a posture holding plate fixedly provided on a conveying device other than the conveying device to receive the posture holding means. The posture holding mechanism of the device.