JP2521508B2 - Transport vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a carrier vehicle that automatically travels in a work space,
More specifically, the present invention relates to a transportation vehicle including a loading table on which an article is placed and a positioning unit.

[Prior art]

Transport vehicles, especially unmanned transport vehicles, have made great strides in the last few years as core devices in factory automation.

A conventional unmanned transport vehicle has a loading platform on the top surface for placing an article to be transported, and transports the article to a station provided in each step. Then, the transfer device provided in the station automatically transfers the article from the unmanned transport vehicle to each station.

On the other hand, the stopping accuracy of the automatic guided vehicle is about ± 10 mm with respect to the traveling direction and the direction intersecting with it, and about ± 1 ° with respect to the rotation direction around the vertical axis. Since the relative stop position accuracy depends on the stop accuracy of the automatic guided vehicle, it has the same value as the stop accuracy. Due to the error in the stop accuracy, a deviation occurs between the relative stop position between the transfer device and the loading platform and the regular relative stop position. When mounting, it was necessary to provide a structure for eliminating the above-mentioned displacement in the transfer device or the transfer vehicle, or to improve the stop accuracy of the unmanned transfer vehicle.

As a publicly known means for improving the stopping accuracy, a plurality of hydraulic jacks are provided on an unmanned transfer vehicle, and a conical female hole is formed in the rod portion of the hydraulic jack. A plurality of positioning projections each having a conical male portion with a matching shape are provided corresponding to the mounting position of the hydraulic jack, and when the unmanned guided vehicle stops at the station, the hydraulic jacks are advanced and the positioning projections are moved to the outside. There is a means for fitting and positioning. As a result, the automatic guided vehicle is lifted from the floor and positioned at the regular stop position.

[Problems to be Solved by the Invention]

However, in the above-mentioned means, the positioning protrusions obstruct traveling, and a large number of additional equipment such as a water pressure source is required, which leads to an increase in price and a complicated structure. Further, since the means positions by the engagement of the female hole and the male part, the accuracy of the positioning is deteriorated due to the wear of the female hole and the male part, and dust is generated by the abrasion powder, such as in a semiconductor manufacturing factory. It could not be used in the environment where the positioning accuracy and cleanliness were specified.

Further, since the transfer device is provided for each station, if the transfer device is provided with a structure that eliminates the deviation,
A large number of such structures are required, not only the number of parts is increased, but also the kinds of parts are increased and the number of control programs for each is also increased, resulting in an increase in the price of the entire system.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a means for moving and positioning a loading platform in two directions in a horizontal plane and three directions of rotation around a vertical axis. A common purpose is to provide common parts and control programs, and to provide a transport vehicle that enables inexpensive, quick, and highly accurate movement positioning.

[Means for solving the problem]

A transport vehicle according to the present invention includes a base, a rotary base that is rotatable around the base in a vertical direction, and a first movable base that is located on the rotary base and is movable in two directions in a horizontal plane. In a transport vehicle including a loading table having a moving table and a second moving table, which automatically travels in a work space, a drive section provided on the base table and connected to the rotating table via an eccentric cam, A drive unit provided on the rotary table and connected to the first moving table via an eccentric cam, and a drive section provided on the first moving table and connected to the second moving table via an eccentric cam. And a drive unit for rotating the eccentric cam by each drive unit, so that the rotary base, the first movable base, and the second movable base are moved in the rotational direction and in the horizontal plane.
It is characterized in that it is designed to move and position in the direction.

[Action]

INDUSTRIAL APPLICABILITY According to the present invention, the parts and the control program can be made common by combining the rotary base first and second moving bases, the cams linked to the respective rotary bases, and the drive units for driving these cams.
It is possible to perform rapid movement positioning simultaneously in each direction.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof.

FIG. 1 is a left side view of a transportation vehicle according to the present invention, and the transportation vehicle has a direction indicated by an outline arrow as its traveling direction.

In the figure, 1 is a pair of left and right drive shafts 2 of the transport vehicle.
The vehicle body is supported by (right drive wheel is not shown) and four auxiliary wheels 3, 3 provided on the front, rear, left and right (right auxiliary wheel is not shown). The drive wheels 2 are attached to the center of the machine body 1 so as to be appropriately spaced apart from each other, and drive motors (not shown) are coaxially and directly connected to each other. The drive motors are individually driven to steer the machine body 1 and simultaneously drive them. Move Aircraft 1 forward and backward. Further, the auxiliary wheels 3, 3 are rotatably mounted around the vertical axis of the machine body 1 and are attached to the front and rear parts of the machine body 1 at appropriate intervals.

A loading platform 4 for placing an article to be conveyed is provided on the upper portion of the machine body 1 so that its center is the same as that of the machine body 1, and the loading platform 4 is provided in the central portion of the machine body 1 in the traveling direction of the machine body 1. ，
Positioning means in each direction for performing positioning in three directions of a direction orthogonal to the traveling direction and a rotation direction around the vertical axis of the machine body 1
It is attached to the machine body 1 so as to be movable and rotatable in the three directions by 5x, 5y, and 5θ. Further, the positioning means 5x, 5y, 5θ in each direction can be separately driven in the three directions by the driving units 6x, 6y, 6θ in the three directions.

On the other hand, optical sensors 7 _A and 7 _B using an industrial TV camera for detecting the stop position of the body 1 are attached to the front and rear of the center of the body 1 at a distance L from the center of the body 1, respectively. the stopping position of each process, the on the floor surface 9. the optical sensor 7 _a, 7 _B wherein the two positioning labeled 8,8 drawn by the black at the center of the white squares in the same interval optical sensor 7 _a, 7 _B detects the stop position of Aircraft 1 by capturing an image. Further, from the position of the imaged positioning mark 8,8, each drive unit 6x,
Positioning control device 9 that gives drive signals to 6y and 6θ is body 1
It is provided inside.

FIG. 2 is a partially cutaway side view showing the positioning means provided with the drive unit of the loading platform. The positioning means 5x, 5y, 5θ are attached to the front and rear of the central portion of the machine body 1, and are vertical L-shaped vertical members. Two brackets 12, 12 with a rectangular flat plate fixed in the center and whose longitudinal direction is orthogonal to the traveling direction of the machine body 1.
The base 57 is fastened and attached to the top.

The base 57 is in the form of a square flat plate having a side slightly shorter than the length of the loading table in the left-right direction, has a cylindrical boss portion on the upper side of the central portion thereof, and a slewing bearing 52θ is provided inside the boss portion. A drive motor 66θ using a stepping motor for turning is attached to the lower side of the rear center of the platform 57 with its output shaft facing upward. An eccentric shaft 62 having a predetermined eccentric amount with respect to the output shaft is provided at the tip of the drive motor 66θ via a flexible joint 61θ.
θ is connected, and two ball bearings 63θ, 63θ, which are eccentric cams, are fitted onto the upper end of the eccentric shaft 62θ. Also, on the upper center of the rear part of the base 57, there is a mounting flange at the bottom,
A cylindrical bearing box 64θ is mounted coaxially with the drive motor 66θ, and the eccentric shaft 62θ is rotatably supported by two ball bearings 65θ, 65θ fitted in the upper end of the bearing box 64θ. A turntable 50θ described later depending on the amount of eccentricity of the eccentric shaft 62θ.
Rotates around the swivel bearing 52θ.

The inner ring of the slewing bearing 52θ has a flat plate shape having substantially the same outer shape as that of the base 57, and has a rotary boss 50 having a cylindrical boss portion downward in the central portion.
The boss portion of θ is fitted inside, and the rotary base 50θ is rotatable by the swing bearing 52θ in the rotation direction (hereinafter referred to as θ direction) about the vertical axis of the machine body 1 about the swing bearing 52θ. There is. Also, a bearing box having a cylindrical shape in the lower center of the front part of the turntable 50θ and mounting flanges at the upper and lower ends thereof, respectively.
64x is attached, and a drive motor 66x that uses a stepping motor for moving in the front-rear direction (hereinafter referred to as the x direction) is attached to the lower mounting flange with its output shaft facing upward. An eccentric shaft 62 having a predetermined eccentricity amount with respect to the drive motor output shaft via a flexible joint 61x is provided at the tip of the drive motor 66x at the tip of the flexure.
x is connected, and two ball bearings 63x, 63x, which are eccentric cams, are fitted on the upper end of the eccentric shaft 62x. The eccentric shaft 62x has two ball bearings in which the bearing box 64x is internally fitted.
The movable base 50x, which is a first movable base described later, is moved in the x direction by the eccentric amount of the eccentric shaft 62x. In addition, the rails of the linear guides are used to separate the front and rear portions of the movable base 50θ from each other in the x direction.
The individual movement guides 52x, 52x are attached with their longitudinal directions substantially aligned with the x direction of the machine body 1.

FIG. 3 is an enlarged perspective view showing an attached state of the eccentric cam of the drive means of the loading table, and ball bearings 63θ, 63θ which are the eccentric cams.
Is a rectangular flat plate and has a rod-shaped convex portion at one end, and an oblong eccentric cam groove 59θ having a longitudinal length in the same direction as the convex portion is formed in the center thereof. The lower cam receiver
It is internally fitted to the upper cam receiver 53θ formed with an eccentric cam groove 58θ similar to the lower receiving cam 54θ mounted on the upper side of 54θ.
The upper cam receiver 53θ is slid in the direction orthogonal to the longitudinal direction of the eccentric cam groove with respect to the lower cam receiver 54θ by the adjusting screws 55θ and 55θ screwed together so as to be appropriately spaced in the longitudinal direction of the convex portion of the lower cam 54θ. It is freely movable. Further, the lower cam receiver 54θ and the upper cam 53θ are the two ball bearings 63θ, 63 which are eccentric cams.
The outer ring of the upper ball bearing 63θ of θ is pressed against the side surface of the eccentric cam groove 58θ of the upper cam bearing 53θ on the adjusting bolt 55θ side, and the outer ring of the lower ball bearing 63θ of the eccentric cam groove 59θ of the lower cam bearing 54θ. The adjustment bolt 55θ is adjusted so that it is pressed against the side surface on the opposite side of the adjustment bolt 55θ, thereby preloading each outer ring. And the lock nut 56 where this adjustment ends
The rotation of the adjusting bolt 55θ is sealed by θ. The lower cam receiver 54θ and the upper cam receiver 53θ are attached to the center of the rear part of the turntable 50θ.

On the other hand, the movement guides 52x, 52x attached to the turntable 50θ ...
And four upper guides 51x, which are formed by using rolling parts of linear guides that engage with the moving guides 52x, 52x, and roll with respect to the moving guides 52x, 52x.
51x ... Are attached to the lower part of the movable table 50x, and the movable table 50x can be rolled in the x direction with respect to the rotary table 50θ.

The moving table 50x has a flat plate shape having substantially the same outer shape as that of the rotating table 50θ, and a bearing box 64y having a cylindrical shape and having mounting flanges on its upper and lower portions is attached to the lower side of the center on the left side. There is. Further, a drive motor 66y, which uses a stepping motor for moving in the direction orthogonal to the traveling direction, that is, the left-right direction of the machine body 1 (hereinafter referred to as y direction), is attached to the lower mounting flange with its output shaft facing upward. ing. An eccentric shaft 62y having a predetermined eccentric amount with respect to the output shaft of the drive motor 66y is connected to the tip of the drive motor 66y via a flexible bearing 61y, and the eccentric shaft 62y has an upper end portion. Two ball bearings 63y, 63y, which are eccentric cams, are externally fitted. The eccentric shaft 62y is supported by two ball bearings 65y, 65y fitted in the upper portion of the bearing box 64y, and is a second moving base described later depending on the eccentric amount of the eccentric shaft 62y. The moving table 50y moves in the y direction. Above the center of the front part of the moving pair 50x, an upper cam receiver 53x and a lower cam receiver 54x, which have the same structure as the upper cam receiver 53θ and the lower cam receiver 54θ attached to the rotary base 50θ, are eccentric cams. The grooves 58x and 59x are mounted with the longitudinal direction of the grooves 58x and 59x. Further, four y-direction movement guides 52y, 52y ... Using linear guide rail portions are attached to the upper and lower portions of the movable table 50x at appropriate intervals. And 4 using the rolling part of the linear guide
Moving table 50y in which each of the upper guides 51y, 51y is a rectangular flat plate.
Is attached to the lower part of the movable guide 50y so as to be engaged with the moving guides 52y, 52y ..., and the moving base 50y can be rolled in the y direction. Also, the ball bearings 63y, 6
The upper cam receiver 53y and the lower cam receiver 54y, which are engaged with 3y and have the same structure as the upper cam receiver 53θ and the lower cam 54θ, define the longitudinal direction of the eccentric cam grooves 58y and 59y as the x direction, and the upper and lower parts thereof are The upper cam receiver 53θ and the lower cam receiver 54θ are installed in reverse. And the loading table 4 is located above the moving table 50y.
A loading section 41 for loading the articles constituting the above is attached.

FIG. 4 is a block diagram showing the configuration of a positioning control device for a guided vehicle according to the present invention, in which the positioning control device 9 detects the positions of the positioning markers 8, 8 imaged by the optical sensors 7 _A , 7 _B. Center position of the visual field of the detection unit 91 and the optical sensor
Center of gravity position P _A ′ of positioning markers 8, 8 detected as P _A , P _B
The deviations from P _B ′ are calculated, and based on the deviations, the positioning correction values Δx, Δy, in the x-direction, the y-direction, and the θ-direction for positioning the loading table 4 of the transport vehicle in the direction for eliminating the deviation amount.
Positioning correction calculation unit 92 for calculating Δθ and drive motors 66x, 66y, 66 for the calculated positioning correction values Δx, Δy, Δθ.
Memorize the relationship between the number of pulses given to θ and the predetermined number of pulses Lx, Ly, L for each drive motor 66x, 66y, 66θ based on that memory.
A motor drive unit 93 that gives θ is provided.

Next, a method of controlling the transport vehicle and calculating a positioning correction value at the stop position according to the present invention will be described. The positioning correction values Δx, Δy, Δθ are the drive parts 6x, 6y, 6θ of the loading table 4 in order to match the center position G of the loading table 4 and its x direction with the intermediate position G ′ of the positioning markers 8, 8 and its installation direction. The above deviation is eliminated.

FIG. 5 is a flow chart showing the flow of control, and FIG. 6 is a view for explaining the method of calculating the positioning correction value, but the transport vehicle automatically moves toward the station provided in each process by a predetermined guiding device. The vehicle travels and stops the black circle at the center of the positioning marks 8 and 8 at a position where the visual fields of the optical sensors 7 _A and 7 _B can be captured. When the transport vehicle stops, the positioning markers 8 and 8 are imaged by the optical sensors 7 _A and 7 _B , and based on the imaging result, the position detecting unit 91 sets the intermediate position G ′ of the positioning markers 8 and 8 as the origin and sets the installation direction. The distance d _XA , d _YA , d between the center position PA, PB of the visual field and the positioning markers P _A ′, P _B ′ in a coordinate system with the X ′ axis and the Y ′ axis in the direction orthogonal to the X ′ axis.
_{Find XB} , d _YB . In the positioning correction value calculation unit 92, the respective positioning correction values Δx, Δy, Δ are calculated by the calculation method described later from the respective distances d _XA , d _XB , d _YA , d _YB obtained by the position detection unit 91.
Calculate θ. Then, the motor drive unit 93 outputs the respective positioning correction values Δx, Δy, Δθ to the required pulses Lx, Ly,
Converted to Lθ, the required pulse Lx, Ly, Lθ is converted to each drive motor.
Output to 66x, 66y, 66θ.

 Thereby, the loading platform 4 is positioned.

On the other hand, the calculation of each of the positioning correction values Δx, Δy, Δθ is performed when the position of the center of gravity of the positioning markers 8, 8 is captured within the field of view of the optical sensors 7 _A , 7 _B shown by the two-dot chain line in FIG. d _XA ,
d _YA , d _XB , d _YB are _calculated . The positioning correction values Δx, Δy, and Δθ are calculated by the following equations based on the calculated distances.

However, 2L: Installation distance of positioning markers 8 and 8 Positioning correction values Δx and Δ according to the above equations (1) to (3)
y, Δθ is obtained, and a predetermined pulse number Lx, Ly, Lθ corresponding to each positioning correction value Δx, Δy, Δθ is output by the motor drive unit 93, and each drive motor 66x, 66y, 66θ is driven. The loading platform 4 is positioned at the regular stop position. The amounts of movement and rotation in the three directions due to the amount of eccentricity are sufficiently large with respect to the amount of deviation (± 15 mm in the x direction and ± 20 in the y direction in this embodiment).
mm, θ direction ± 2 °), the relative positional accuracy between the loading platform and the transfer device is ± 1 mm in the x and y directions, and the allowable value in the θ direction, even if the transport vehicle stop accuracy is not sufficient. It became possible to keep it within.

Further, in such an embodiment, the bearing housings 64x, 64y, 64
θ, upper cam receiver 53x, 53y, 53θ, lower cam receiver 54x, 54y, 54
It was confirmed that many components such as θ, ball bearings 65x, 65y, 65θ, flexible bearings 61x, 61y, 61θ, and other motors serving as drive units can be shared.

Further, in this embodiment, since the eccentric cam using the ball bearing is used and the outer ring is preloaded, the structure of the positioning means can be simplified and the play between the eccentric cam and the eccentric cam groove can be suppressed. This enabled smooth positioning.

Further, in the present embodiment, the stepping motor is used as the drive motor, but the present invention is not limited to this, and any motor capable of position control such as a servomotor with an encoder may be used.

〔effect〕

As described above, in the present invention, the base, the rotary base that is rotatable around the base vertically, and the rotary base that is located on the rotary base and is movable in two directions in the horizontal plane. In a transport vehicle that is equipped with a loading table having a first moving table and a second moving table and that automatically travels in a work space, a drive unit that is provided on the base table and is connected to the rotating table via an eccentric cam. A drive unit provided on the rotary table and connected to the first moving table via an eccentric cam; and a drive section provided on the first moving table, and to the second moving table via an eccentric cam. With a drive unit connected to each other,
By rotating the eccentric cam by each drive unit, the rotary base, the first movable base, and the second movable base are moved and positioned in the rotational direction and two directions in the horizontal plane. The structure of the cam itself and the connecting structure of the drive unit and the eccentric cam can be made common, the parts can be made common, the types of the parts can be reduced, and the cost of the parts can be significantly reduced. The control programs can be standardized,
Further, the present invention has an excellent effect such that quick and accurate movement and positioning can be performed simultaneously in three directions.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a left side view of a carrier vehicle according to the present invention, FIG. 2 is a partially cutaway side view showing positioning means of a loading platform, and FIG. FIG. 4 is an enlarged perspective view showing the mounting state of the eccentric cam, FIG. 4 is a block diagram showing the configuration of the positioning control device of the present invention, FIG. 5 is a flowchart showing the flow of control, and FIG. 6 is a method for calculating the positioning value. It is a diagram showing. 1 ... machine, 5x ... x direction positioning means, 5y ... y direction positioning means, 5θ ... θ direction positioning means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Kishimoto 4-1788 Tsurumi, Tsurumi-ku, Osaka City, Osaka Prefecture Tsubakimoto Chain Co., Ltd. (72) Inventor Takeyuki Suzuki 4-chome, Tsurumi, Tsurumi-ku, Osaka No. 88 Tsubakimoto Chain Co., Ltd. (56) Reference JP-A-62-267809 (JP, A) JP-A-60-231218 (JP, A)

Claims (1)

(57) [Claims] 1. A base, a rotary base that is rotatable about a vertical direction of the base, and a first movable base that is located on the rotary base and is separately movable in two directions in a horizontal plane. A transport vehicle that includes a loading platform having a second moving platform and that automatically travels in a workplace, a drive unit that is provided on the base platform and is connected to the rotary platform via an eccentric cam, and the rotary platform. And a drive unit connected to the first movable base via an eccentric cam, and a drive unit connected to the second movable base provided on the first movable base via an eccentric cam. And rotating the eccentric cam by each of the drive units to move and position the rotary base, the first movable base, and the second movable base in two directions of a rotation direction and a horizontal plane. Characterized transport vehicle.