Workpiece transfer device

Abstract

To provide a workpiece transport device that can stably transport a workpiece in a linear transfer device with a non-terminally running track, reduce the number of movers, narrow the intervals between transported workpieces, achieve improved efficiency of transport and space saving of the device, and also reduce costs.SOLUTION: A mover 3 is formed as either a holding mover 3A equipped with a gripper mechanism 5 consisting of a pair of grippers 6 for holding a workpiece, or an opening / closing mover 3B for opening / closing the pair of grippers 6, and a coupling mechanism 7 that connects one opening / closing mover 3B to each gripper mechanism 5 of one or more holding movers 3A configures the opening / closing mover 3B and one or more holding movers 3A as a group of shuttles 8. The gripper 6 of each gripper mechanism 5 is configured to open and close freely by position control of the opening / closing mover 3B that adjusts the interval with the adjacent holding mover 3A.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a workpiece transfer device using a linear transfer system.

Background Art

[0002] Conventionally, a device has been proposed that uses a linear transfer system to sandwich a workpiece between adjacent movers (moving elements) and travels along a travel path to transfer the workpiece.

[0003] For example, the linear transfer device disclosed in Patent Document 1 is an invention device that aims to safely transfer an article without changing the distance between holding members provided on adjacent movers even in a linear transfer device having linear and curved travel paths. On a base, the device includes a stator and a mover of a linear motor, and a holding member for an article provided on the mover. The holding member is provided at a position radially outward from the travel path in the stator of the mover by a predetermined distance. When the mover travels along a curved travel path in the stator, the control unit controls the distance between adjacent movers to be narrower than the distance when traveling along the immediately preceding linear travel path. On the other hand, when the mover travels along a linear travel path in the stator, the control unit controls the distance between adjacent movers to be wider than the distance when traveling along the immediately preceding curved travel path, thereby configuring the distance between the holding members of adjacent movers to be constant.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When a single workpiece is held by two movable elements and transported along a track in this manner, many movable elements are required to transport the workpiece, which naturally necessitates setting a longer track, resulting in increased costs.

[0006] This invention has been made in view of the above problems, and aims to provide a workpiece transport device that can stably transport workpieces in a linear transport device having an endless travel track, reduce the number of movers, and narrow the spacing (pitch) between transported workpieces, thereby improving transport efficiency, saving space in the device, and reducing costs. [Means for solving the problem]

[0007] To achieve the aforementioned objectives, the present invention provides a workpiece transport device comprising an endless travel track on which stators of linear motors are arranged, and a plurality of movers whose movement and stopping on the travel track can be individually controlled, wherein a workpiece transport path from a workpiece receiving position to a workpiece discharge position is provided within the travel track, wherein each mover is formed as either a holding mover equipped with a gripper mechanism having a gripper for holding a workpiece, or an opening / closing mover for opening and closing the gripper, and one opening / closing mover and one or more holding movers are configured as a group of shuttles by one or more connecting mechanisms that sequentially connect adjacent gripper mechanisms of one opening / closing mover and one or more holding movers, and the gripper of each gripper mechanism is configured to be openable and closable by position control of the opening / closing mover which adjusts the gap with the adjacent holding mover.

[0008] Specifically, each gripper mechanism comprises two types of claw members: a fixed claw member and a movable claw member arranged to open and close using a pivot point. The movable claw member is connected to the connecting mechanism, and the movable claw member is configured to open and close by position control that adjusts the gap between the opening / closing movable element and the adjacent holding movable element.

[0009] The workpiece transport device of the present invention, configured in this way, can open and close the movable claw member of the gripper mechanism by narrowing or widening the gap between the opening / closing movable element and the adjacent holding movable element. This allows the gripper mechanism to be transported in a closed state along both straight and curved travel paths without changing the distance between one opening / closing movable element and one or more holding movable elements.

[0010] Furthermore, the shuttle is equipped with the gripper mechanism and is characterized in that it includes a connecting gripper that is supported by at least one movable element and moves in a manner that allows the pair of grippers of the gripper mechanism to be opened and closed by the connecting mechanism.

[0011] With the workpiece transport device of the present invention configured in this way, it is possible to transport more workpieces with fewer movable elements than in the conventional method described above, where one workpiece is gripped by two movable elements and transported along a travel track, and space can be saved. Furthermore, transport efficiency can be further improved by narrowing the spacing (pitch) between the transported workpieces. [Effects of the Invention]

[0012] Thus, the workpiece transport device of the present invention can stably transport workpieces in a linear transport device having an endless travel track, reduce the number of movers, and narrow the spacing (pitch) between transported workpieces, thereby improving transport efficiency, saving space in the device, and reducing costs. [Brief explanation of the drawing]

[0013] [Figure 1] Plan view illustrating the overall configuration of one embodiment of the workpiece transport device of the present invention. [Figure 2] (A) An explanatory diagram showing the open state of the gripper mechanism in the shuttle according to the embodiment of Figure 1, (B) An explanatory diagram showing the closed state of the gripper mechanism in the shuttle according to the embodiment of Figure 1. [Figure 3] Partial explanatory diagram of the state of the shuttle during travel on a curved section according to the embodiment shown in Figure 1. [Figure 4] An example showing a different configuration from the shuttle in the embodiment of Figure 1. [Modes for carrying out the invention]

[0014] Hereinafter, one embodiment of the workpiece transport device 1 according to the present invention will be described with reference to Figures 1 to 3.

[0015] The workpiece transport device 1 of this embodiment employs a known linear transport device and is configured to hold the container B, which is the workpiece, at a workpiece receiving position P1 provided on the straight section of the endless travel track, transport it through the curved travel track to the next straight section of the travel track to the discharge position P2, and then release the hold to send the container B to the next process (hereinafter, the range of the container B from the receiving position P1 to the discharge position P2 within the travel track is referred to as the workpiece transport path 4).

[0016] Specifically, the workpiece transfer device 1 comprises an endless travel track 2, a plurality of moving elements 3 that move along this travel track, and a linear motor (not shown) that moves the moving elements 3 along the travel track 2.

[0017] The linear motor comprises a permanent magnet (not shown) fixed to each of the moving elements 3, and a number of electromagnetic coils (not shown) arranged at equal pitches along the longitudinal direction of the travel track 2. By controlling the supply and cessation of current to each of the electromagnetic coils with a control unit (not shown), each moving element 3 can be individually controlled to move and stop.

[0018] In this embodiment, as shown in FIG. 1, the travel track 2 is formed in an oval track shape in plan view. Near the receiving position P1 of the container B, a robot (not shown) is arranged which grips the container B supplied on a supply conveyor (not shown) and transfers it to the gripper mechanism 5 described later in an upright state. Further, a transfer conveyor (not shown) is arranged at the unloading position P2 of the container B, and the container B which is transferred in an upright state and released from gripping is dropped onto the transfer conveyor as it is and erected, and is configured to be transferred to the next process.

[0019] Each of the movers 3 is formed as either a holding mover 3A equipped with a gripper mechanism 5 having a pair of grippers 6 that hold gripping parts such as the neck part and body part of the container B, or an opening / closing mover 3B for mechanically opening and closing the pair of grippers 6. And one opening / closing mover 3B is sequentially connected to the gripper mechanisms 5 of the three holding movers 3A by a connecting mechanism 7, and is configured as a group of shuttles 8. And in this embodiment, the connecting mechanism 7 acts to open and close the pair of grippers 6 of each gripper mechanism 5 by position control for adjusting the gap between the opening / closing mover 3B and the adjacent holding mover 3A.

[0020] In this embodiment, as shown in FIG. 2, the shuttle 8 is composed of a total of four movers 3, namely, one opening / closing mover 3B arranged on the travel direction side of the travel track 2 and three subsequent holding movers 3A (hereinafter, as necessary for the explanation, the holding movers 3A will be described as the first holding mover 3Aa, the second holding mover 3Ab, and the third holding mover 3Ac in the order of arrangement in the travel direction).

[0021] The gripper 6 of each holding mover 3A includes a pair of two types of claw members, namely, a fixed-side claw member 6A mounted on the mover 3 and a movable-side claw member 6B pivotally supported at the main body base of the fixed-side claw member 6A with a pivot point 9.

[0022] In this embodiment, the fixed-side claw member 6A is disposed such that the recess of the work holding portion 10 adapted to the outer shape of the container B is directed in the traveling direction (forward) on the rear side in the traveling direction of the traveling track 2, and the movable-side claw member 6B is disposed such that the recess of the work holding portion 10 adapted to the outer shape of the container B is directed in the reverse traveling direction (rearward) on the front side in the traveling direction of the traveling track 2. When the movable-side claw member 6B rotates about the rotation fulcrum 9, it approaches and separates from the fixed-side claw member 6A, and in the close state where they are close to each other, the container B is stably held in a centered state within the recesses of the respective work holding portions 10 of the fixed-side claw member 6A and the movable-side claw member 6B.

[0023] Here, the movable-side claw member 6B is a substantially crank-shaped arm member, and the work holding portion 10 is formed at the tip side thereof. With the bent portion near the base end as the rotation fulcrum 9, it is disposed on the main body base portion of the fixed-side claw member 6A. And at the base end on the opposite side of the work holding portion 10 of each movable-side claw member 6B across the rotation fulcrum 9, the end portion of the long plate-shaped connecting bar 7A as the connecting mechanism 7 for sequentially connecting the respective gripper mechanisms 5 of the adjacent opening / closing mover 3B and / or the holding mover 3A is fixed. That is, in this embodiment, one end portion of the connecting bar 7A is fixed to the opening / closing mover 3B via a stay, and the other end portion of the connecting bar 7A is pivotally supported at the base end of the movable-side claw member 6B of the first holding mover 3Aa and disposed. Also, connecting bars 7A are disposed between the first holding mover 3Aa and the second holding mover 3Ab, and between the second holding mover 3Ab and the third holding mover 3Ac, with the respective end portions pivotally supported by the connecting shaft 7b at the base end of the movable-side claw member 6B of each holding mover 3A. The connecting shaft 7b acts as the force point of the movable-side claw member 6B of each gripper mechanism 5.

[0024] The multiple (specifically three) connecting bars 7A of the connecting mechanism 7 are connected by a connecting shaft 7 and operate as a single unit. Therefore, each gripper mechanism 5 can slide relative to the connecting mechanism 7 connected to the movable claw member 6B along the travel track 2 by adjusting the position of the opening / closing movable element 3B and the subsequent holding movable element 3A, and more specifically, the gap with the first holding movable element 3Aa. As a result, the movable claw member 6B is rotated at the pivot point 9, and the gripper 6 can be opened and closed.

[0025] Next, the operation of the workpiece transport device 1 of this embodiment will be explained.

[0026] In the workpiece transport device 1 of this embodiment, a plurality of shuttles 8 are arranged on the travel track 2. A shuttle 8 equipped with three holding movers 3A, from the first holding mover 3Aa to the third holding mover 3Ac, holds three containers B at once at the workpiece receiving position P1 on the endless travel track 2, transports them along the workpiece transport path 4, and releases its hold at the discharge position P2, thereby sending the three containers B to the next process.

[0027] Shuttle 8 travels along the work transport path 4 with the opening / closing movable element 3B leading, and reaches the work receiving position P1. At the work receiving position P1, the stopping positions of each movable element 3 are controlled so that the pitch between the opening / closing movable element 3B and the first holding movable element 3Aa becomes smaller.

[0028] In other words, as shown in Figure 2(A), when the pitch between the opening / closing movable element 3B and the first holding movable element 3Aa is reduced, the connecting bar 7A of the connecting mechanism 7, whose tip is connected to the opening / closing movable element 3B, slides backward along the travel track 2 relative to the first holding movable element 3Aa to the third holding movable element 3Ac. This causes the movable claw member 6B of the gripper mechanism 5 to rotate around the pivot point 9, separating the workpiece holding portion 10 of the movable claw member 6B from the workpiece holding portion 10 of the fixed claw member 6A, resulting in an open state.

[0029] After positioning the container B within the recesses of the workpiece holding portions 10 of both claw members 6A and 6B at the workpiece receiving position P1, as shown in Figure 2(B), the opening / closing movable member 3B is slid along the travel track 2 in the direction of travel so as to widen the pitch between the opening / closing movable member 3B and the first holding movable member 3Aa, and the movable claw member 6B of the gripper mechanism 5 is rotated on the pivot point 9, closing the workpiece holding portion 10 of the movable claw member 6B so that it is close to the workpiece holding portion 10 of the fixed claw member 6A, and the container B is held in the workpiece holding portion 10 in a centered state.

[0030] Then, the opening / closing movable element 3B and the first holding movable elements 3Aa to the third holding movable elements 3Ac that constitute the shuttle 8 are moved by the action and control of the linear motor while maintaining their relative positions, passing through the curved section of the travel track 2 and moving to the discharge position P2.

[0031] In this embodiment, the workpiece transport device 1 travels in a curved section of the travel track 2, as shown in Figure 3, with the opening / closing movable element 3B and the first holding movable elements 3Aa to the third holding movable elements 3Ac shortening the distance between them (x-β) on the travel track side closer to the center of curvature of the curved section (x-β) compared to a certain dimension (x) connected by the connecting bar 7, and widening the distance between them (x+θ) on the workpiece holding section 10 side further away from the center of curvature. However, at the position where the connecting bar 7A of the connecting mechanism 7 is located, a constant distance (x) is always maintained, preventing the workpiece holding section 10 from loosening and dropping the container B, thus enabling stable transport.

[0032] At the discharge position P2, the stopping position of each movable element 3 is controlled so that the pitch between the opening / closing movable element 3B and the first holding movable element 3Aa becomes narrower. As a result, the connecting bar 7A of the connecting mechanism 7 slides backward along the travel track 2 relative to the first holding movable elements 3Aa to the third holding movable elements 3Ac, causing the movable claw member 6B of the gripper mechanism 5 to rotate around the pivot point 9, separating the workpiece holding portion 10 of the movable claw member 6B from the workpiece holding portion 10 of the fixed claw member 6A, opening it and releasing the grip on the container B.

[0033] Once the gripping of container B is released, it is guided upright onto a conveyor belt (not shown) and transported to the next process. After completing the transport of container B, shuttle 8 is then sent back towards the receiving position P1 for container B.

[0034] Thus, with the workpiece transport device 1 of this embodiment, stable transport of container B can be performed, the number of movers can be reduced, and the spacing (pitch) between the transported workpieces can be narrowed, thereby improving transport efficiency, saving space in the device, and reducing costs.

[0035] Here, Figure 4 is an explanatory diagram showing another configuration of the shuttle 8. The shuttle 8 shown in Figure 4 is configured with a connecting gripper 12 at the rear of the shuttle 8, which consists of the group of moving elements 3. The connecting gripper 12 has a gripper mechanism 5 consisting of a pair of grippers 6 that hold containers B, and is cantilevered from the third holding moving element 3Ac by a support member 11 so that the gripper mechanism 5 is positioned at the spacing of the containers B to be transported. The connecting bar 7A of the connecting mechanism 7 connects the grippers 6 of the gripper mechanism 5 so that they can be opened and closed, similar to the shuttle 8 of the previously described embodiment. That is, the connecting gripper 12 is not directly mounted on the opening / closing moving element 3B, but is supported by the opening / closing moving element 3B so that the gripper mechanisms 5 it has are arranged at a predetermined interval in the direction of travel. Together with the holding moving element 3A and the opening / closing moving element 3B, the shuttle 8 is formed as a group and moves along the work transport path 4.

[0036] By equipping the shuttle 8 with this configuration, it becomes possible to transport more containers B with fewer moving elements 3 than in conventional systems, thus saving space. Furthermore, by narrowing the spacing (pitch) between the transported containers B, the transport efficiency can be further improved.

[0037] The workpiece transport device of the present invention is not limited to the embodiments described above. Various modifications can be made as long as the features of the present invention are not impaired.

[0038] The configuration of the gripper 6 is not limited to the two-claw type described above, and the positional relationship between the fixed claw member 6A and the movable claw member 6B is not limited to the embodiment described above. Furthermore, the gripper 6 may be configured such that, for example, both claw members rotate together to move toward and away from each other in the horizontal plane.

[0039] Furthermore, the arrangement order of the opening / closing movable element 3B and the holding movable element 3A is not limited to the embodiment described above. Essentially, any mechanism that mechanically opens and closes the gripper 6 by sliding the connecting bar 7A of the coupling mechanism 7 by controlling the stopping position of the opening / closing movable element 3B relative to the holding movable element 3A is sufficient. It is crucial that the mechanism is configured to allow adjustment of the distance between adjacent movable elements 3 in the endless running track 2, especially in curved sections, according to the distance from the center of curvature.

[0040] Furthermore, the connecting gripper 12 of the shuttle 8 is not limited to being positioned at the rear; for example, it may be supported from both sides by a support member 11 between the second retaining movable element 3Ab and the third retaining movable element 3Ac. [Explanation of Symbols]

[0041] 1. Workpiece transfer device 2. Track 3 Mobile 3A holding slider 3B Opening / Closing Movable Part 4. Workpiece transport route 5. Gripper mechanism 6 Gripper 6A Fixed claw member 6B Movable side claw member 7 Connection mechanism 7A Connecting Bar 8 Shuttle 9. Pivot 10 Workpiece holding section 11 Support member 12-linked grippers B Container (workpiece) P1 (Workpiece) receiving position P2 (Workpiece) unloading position

Claims

1. A workpiece transport device comprising an endless travel track on which stators of linear motors are arranged, and a plurality of movers whose movement and stopping can be individually controlled on the travel track, wherein a workpiece transport path from a workpiece receiving position to a workpiece discharge position is provided within the travel track, Each of the aforementioned moving elements is formed as either a holding moving element equipped with a gripper mechanism having a gripper for holding a workpiece, or an opening / closing moving element for opening and closing the gripper, and one opening / closing moving element and one or more of the holding moving elements are configured as a group of shuttles by one or more connecting mechanisms that sequentially connect adjacent gripper mechanisms of one opening / closing moving element and one or more of the holding moving elements, and the gripper of each gripper mechanism is configured to be openable and closable by position control of the opening / closing moving element that adjusts the gap between adjacent holding moving elements.

2. The workpiece conveying device according to claim 1, wherein each gripper mechanism comprises two types of claw members: a fixed claw member and a movable claw member arranged to be openable and closable with respect to a pivot point, the connecting mechanism is connected to the movable claw member, and the movable claw member is configured to be openable and closable by position control that adjusts the gap between the opening / closing moving element and the adjacent holding moving element.

3. The workpiece conveying device according to claim 1 or 2, wherein the shuttle is equipped with the gripper mechanism and includes a connecting gripper that is supported by at least one movable element and moves in an openable and closable manner by the connecting mechanism that connects the pair of grippers of the gripper mechanism.

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