Conveying device

Abstract

Even on production lines with short cycle times, we aim to create a low-cost conveying system that can appropriately transport two different types of workpieces with distinct external shapes. [Solution] A transport device 1 for transporting a workpiece to a predetermined position, comprising a clamp unit 3 for gripping the workpiece during transport. The clamp unit 3 has a first workpiece gripping section 4, a second workpiece gripping section 5 that moves between two positions: a gripping position in cooperation with the first workpiece gripping section 4 to grip the workpiece and a retracted position that does not contact the workpiece, and a third workpiece gripping section 6 that moves between two positions: a gripping position in cooperation with the first workpiece holding section 4 to grip the workpiece and a retracted position that does not contact the workpiece. When the second workpiece gripping section 5 is in the gripping position, the third workpiece gripping section 6 is in the retracted position, and when the third workpiece gripping section 6 is in the gripping position, the second workpiece gripping section 5 is in the retracted position.

Description

Technical Field

[0001] The present invention relates to a conveying device for conveying a workpiece.

Background Art

[0002] When conveying a workpiece acquired at a first position (e.g., a stock position) to a predetermined second position (e.g., an incorporation position) in a production line for producing a predetermined product, if there are two types of workpieces to be conveyed and their outer shapes are different from each other, for example, a conveying device in which a workpiece gripping portion provided for gripping the workpiece to be conveyed is a detachable attachment, that is, a conveying device in which the workpiece gripping portion is replaced with one corresponding to the shape of the workpiece every time the workpiece to be conveyed is changed, has been used. However, for the purpose of simplifying the device (suppressing capital investment), in the case of a conveying device in which the replacement work of the attachment-type workpiece gripping portion is performed manually, the replacement work is time-consuming, making it difficult to use in a production line with a short tact time.

[0003] The above problem can be solved, for example, by installing two dedicated conveying devices each having a workpiece gripping portion corresponding to the outer shape of the workpiece. However, such a countermeasure cannot be easily adopted because it newly causes problems of installation space and cost (capital investment).

[0004] Therefore, in Patent Document 1 below, a conveying device has been proposed in which a portion of the workpiece gripping portion that contacts the workpiece is deformed following the shape of the workpiece and the deformed state can be maintained. In this case, since it is not necessary to replace the workpiece gripping portion according to the workpiece to be conveyed, it is considered possible to use it in a production line with a short tact time. The contact portion with the workpiece in the conveying device of Patent Document 1 is configured, for example, by filling a bag-shaped member having elasticity with a large number of granular materials. In this case, by reducing the pressure inside the bag-shaped member and increasing the volume ratio of the granular materials to the internal volume of the bag-shaped member, the granular materials are hardened and the deformed shape is maintained.

Prior Art Documents

[0005] [Patent Document 1] International Publication No. 2012 / 101953 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in the conveying device described in Patent Document 1, in order to appropriately grip and convey two types of workpieces with different external shapes, it is necessary to precisely control the position of the workpiece gripping part relative to the workpiece to be gripped (conveyed), and the pressure of the part of the workpiece gripping part that contacts the workpiece. This raises concerns that it may lead to a complex control system and, consequently, a high cost for the conveying device.

[0007] In view of the circumstances described herein, the main objective of the present invention is to realize a conveying device that can appropriately convey two types of workpieces having different external shapes at a low cost. [Means for solving the problem]

[0008] The present invention, devised to achieve the above objective, is a conveying device for transporting a workpiece to a predetermined position, comprising a gripping means for gripping the workpiece during transport, and this gripping means is First workpiece gripping section, A second workpiece gripping unit moves between two positions: a gripping position in cooperation with the first workpiece gripping unit to grip the workpiece, and a retracted position in which it does not contact the workpiece. It has a third workpiece gripping section that is positioned at a distance from the second workpiece gripping section and moves between two positions: a gripping position in cooperation with the first workpiece holding section to grip the workpiece, and a retracted position that does not come into contact with the workpiece. The invention is characterized in that when the second workpiece gripping section is in the gripping position, the third workpiece gripping section is in the retracted position, and when the third workpiece gripping section is in the gripping position, the second workpiece gripping section is in the retracted position.

[0009] In the conveying device according to the present invention having the above configuration, by controlling the positions of the second and third workpiece gripping parts provided on the gripping means for gripping the workpiece, it is possible to switch between a mode in which the first and second workpiece gripping parts cooperate to grip the workpiece and a mode in which the first and third workpiece gripping parts cooperate to grip the workpiece. Therefore, when gripping and conveying two types of workpieces with different external shapes, it is not necessary to provide two dedicated conveying devices (the conveying device can be shared). Furthermore, since the second and third workpiece gripping parts only move between two positions, a gripping position and a retracted position, and there is no need to perform fine positional control with respect to the workpiece to be gripped, inexpensive devices such as fluid cylinders can be used as the moving means for moving the second workpiece gripping part between the two positions and the moving means for moving the third workpiece gripping part between the two positions. Moreover, if a fluid cylinder is used, switching between the two modes can be performed easily and smoothly. Based on the above, the present invention makes it possible to realize a low-cost conveying device that can appropriately convey two types of workpieces with different external shapes, even in a production line with a short cycle time.

[0010] In the above configuration, it is preferable that the first workpiece gripping section, the second workpiece gripping section, and the third workpiece gripping section all have claws that contact and support the workpiece from below. This reduces the possibility of the workpiece falling during transport, especially if the workpiece being transported is heavy. [Effects of the Invention]

[0011] Based on the above, the present invention makes it possible to inexpensively realize a conveying device that can appropriately convey two types of workpieces with different external shapes, even in a production line with a short cycle time. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram showing the workpiece transport state by a transport device according to an embodiment of the present invention. [Figure 2]This is a schematic perspective view of a conveying device according to an embodiment of the present invention, and is a schematic perspective view of the conveying device in a state in which it can grip a first workpiece. [Figure 3] (a) is a schematic plan view showing the arrangement of the first to third workpiece gripping sections in the conveying device shown in Figure 2, and (b) is a schematic side view of Figure (a) as seen from the direction of arrow A in the same figure. [Figure 4] This is a schematic perspective view of a conveying device according to an embodiment of the present invention, showing the conveying device in a state in which it can grip a second workpiece having a different external shape from the first workpiece. [Figure 5] (a) is a schematic plan view showing the arrangement of the first to third workpiece gripping sections in the conveying device shown in Figure 4, and (b) is a schematic side view of Figure (a) as seen from the direction of arrow A in the same figure. [Modes for carrying out the invention]

[0013] Hereinafter, embodiments of the present invention will be described based on the drawings (Figures 1 to 5).

[0014] As conceptually shown in Figure 1, the transport device 1 according to an embodiment of the present invention moves between two positions, a first position P1 and a second position P2, by receiving power from an external source. When moving from the first position P1 to the second position P2, the clamp unit 3 (details to be described later) as a gripping means transports the workpiece gripped (acquired) at the first position P1 to the second position P2. This transport device 1 is used, for example, in an automobile assembly plant to acquire large parts to be incorporated into the chassis at the stock position, which is the first position P1, and transport them to the installation position, which is the second position P2. Examples of the large parts (workpieces) include the traction batteries of BEVs and HEVs, as well as instrument panels, also abbreviated as instrument panels. Although not shown in the diagram, it is preferable that the transport device 1 be able to move up and down at the first position P1 and the second position P2 in order to smoothly and safely acquire the workpiece at the first position P1 and release the workpiece at the second position P2 (assemble the workpiece onto the chassis) without damaging the workpiece.

[0015] As shown in FIGS. 2 to 5, the transfer device 1 has a rectangular outline in plan view (top view), and includes a base portion 2 that slides along a guide rail provided between a first position P1 and a second position P2, and a clamp unit 3 mounted on the base portion 2 and serving as gripping means for gripping a workpiece to be transferred.

[0016] The clamp unit 3 has a first workpiece gripping portion 4 (omitted in FIGS. 2 and 4), a second workpiece gripping portion 5, and a third workpiece gripping portion 6 that are arranged at intervals along the side (outline) of the base portion 2 having a rectangular outline. Here, the first workpiece gripping portion 4, the second workpiece gripping portion 5, and the third workpiece gripping portion 6 are respectively arranged along the upper side, the lower side, and the right and left sides of the base portion 2 in plan view.

[0017] The above clamp unit 3 can be switched between a first clamp mode in which the first workpiece W1 is gripped by the cooperation of the first workpiece gripping portion 4 and the second workpiece gripping portion 5, and a second clamp mode in which a second workpiece W2 having an outer shape different from that of the first workpiece W1 is gripped by the cooperation of the first workpiece gripping portion 4 and the pair of third workpiece gripping portions 6. Therefore, this transfer device 1 can transfer two types of workpieces (the first workpiece W1 and the second workpiece W2) having different outer shapes. As shown in FIGS. 2 to 5, the second workpiece W2 in the illustrated example has a flat outer shape in which the lateral width x2 and the vertical width y2 are respectively larger than the lateral width x1 and the vertical width y1 of the first workpiece W1, and the height z2 is smaller than the height z1 of the first workpiece W1.

[0018] The first workpiece gripping portion 4 has an arm portion 4a extending in the vertical direction and a claw portion 4b provided at the lower end of the arm portion 4a. The base portion 2 has an upper table 2A and a lower table 2B arranged at intervals in the vertical direction, and the upper end portion of the first workpiece gripping portion 4 is fixedly attached to the base portion 2 (the lower table 2B thereof). Therefore, the relative positions of the first workpiece gripping portion 4 and the base portion 2 (the lower table 2B thereof) in the vertical and horizontal directions do not change.

[0019] The second workpiece gripping part 5 has an arm part 5a extending in the vertical direction and a claw part 5b provided at the lower end of the arm part 5a, and is provided to be movable between a gripping position [see Fig. 3(a)] where it cooperates with the first workpiece gripping part 4 to grip the workpiece and a retracted position where it does not contact the workpiece [between the two positions in Fig. 5(a)].

[0020] When the second workpiece gripping part 5 is in the gripping position, the clamp unit 3 is in the first clamp mode for gripping the first workpiece W1. That is, when the second workpiece gripping part 5 is in the gripping position, as shown in Figs. 3(a) and (b), the arm part 5a contacts the first workpiece W1, the claw part 5b is located below the first workpiece W1, and the arm part 4a of the first workpiece gripping part 4 arranged on the opposite side of the second workpiece gripping part across the first workpiece W1 contacts the first workpiece and the claw part 4b is located below the first workpiece. Thereby, the first workpiece W1 is gripped by the clamp unit 3 and is contact-supported from below.

[0021] The second workpiece gripping part 5 is supported on the base part 2 (the upper table 2A thereof) via a first fluid cylinder 7 arranged in a horizontal posture and a second fluid cylinder 8 arranged in a vertical posture. Therefore, unlike the first workpiece gripping part 4, the relative positions of the second workpiece gripping part 5 in the vertical and horizontal directions with respect to the base part 2 change. In the illustrated example, a plate-shaped holding member 10 is horizontally attached to the tip of the piston rod 8a of the second fluid cylinder 8 that moves back and forth vertically, and the first fluid cylinder 7 to which the second workpiece gripping part 5 is attached to the tip of the piston rod 7a is horizontally held by this holding member 10. The holding member 10 is attached to the lower end of a guide shaft 11 extending in the vertical direction, and the guide shaft 11 is inserted into a guide hole provided in the upper table 2A. Thereby, when the piston rod 8a of the second fluid cylinder 8 moves back and forth vertically, the second workpiece gripping part 5 attached to the piston rod 7a of the first fluid cylinder 7 can be moved up and down in a state with a constant posture. [[ID=,10]]

[0022] In this embodiment, when the piston rod 8a of the second fluid cylinder 8 is at its extension limit and the piston rod 7a of the first fluid cylinder 7 is shortened by a predetermined amount from its extension limit, the second workpiece gripping part 5 is positioned to grip the workpiece (first workpiece W1) in cooperation with the first workpiece gripping part 4 (see Figures 2 and 3). On the other hand, when the piston rod 7a of the first fluid cylinder 7 is at its extension limit and the piston rod 8a of the second fluid cylinder 8 is at its shortening limit, the second workpiece gripping part 5 is positioned in a retracted position that does not come into contact with the workpiece (in this case, both the first workpiece W1 and the second workpiece W2), as shown in Figures 4 and 5.

[0023] Furthermore, the first fluid cylinder 7 and the second fluid cylinder 8 described above, as well as the third fluid cylinder 9 described later, can be air cylinders or hydraulic cylinders, and appropriate ones are used depending on the required pressure (in this case, the gripping force for gripping the workpiece).

[0024] Each of the pair of third work gripping parts 6 has an arm portion 6a extending in the vertical direction and a claw portion 6b provided at the lower end of the arm portion 6a, and is provided to be able to reciprocate between two positions: a gripping position in cooperation with the first work gripping part 4 to grip the work to be transported (second work W2) and a retracted position in which it does not come into contact with the work (first work W1).

[0025] When each of the third workpiece gripping sections 6 is in the gripping position, the clamp unit 3 enters a second clamping mode for gripping the second workpiece W2. That is, when the third workpiece gripping section 6 is in the gripping position, as shown in Figures 5(a) and 5(b), the arm section 6a contacts the second workpiece W2 and the claw section 6b is positioned below the second workpiece W2. Additionally, the arm section 4a of the first workpiece gripping section 4, which is fixedly mounted to the base section 2, contacts the second workpiece W2 and the claw section 4b is positioned below the second workpiece W2. As a result, the second workpiece W2 is gripped by the clamp unit 3 of the conveying device 1 and supported by contact from below.

[0026] Both of the third workpiece gripping sections 6 are supported on the base section 2 (lower table 2B) via a third fluid cylinder 9 positioned horizontally. Therefore, the horizontal relative position of the third workpiece gripping section 6 with respect to the base section 2 changes. In this embodiment, the third workpiece gripping section 6 is attached to the tip of the piston rod 9a of the third fluid cylinder 9, which moves back and forth horizontally. When this piston rod 9a is shortened by a predetermined amount from its extension limit, it is positioned in a gripping position that grips the workpiece (second workpiece W2) in cooperation with the first workpiece gripping section 4 (see Figures 4 and 5). On the other hand, when the piston rod 9a of the third fluid cylinder 9 is at its extension limit, the third workpiece gripping section 6 is in a retracted position that does not come into contact with the workpiece (both the first workpiece W1 and the second workpiece W2).

[0027] The transport of a workpiece from a first position P1 to a second position P2 by the transport device 1 having the above configuration is performed, for example, as follows.

[0028] First, when transporting the first workpiece W from the first position P1 to the second position P2, the first workpiece W1 positioned at the first position P1 is gripped by the clamp unit 3 of the transport device 1. Specifically, for example, the piston rod 7a of the first fluid cylinder 7, the piston rod 8a of the second fluid cylinder 8, and the piston rod 9a of the third fluid cylinder 9 are all positioned at their maximum extension (the second workpiece gripping section 5 and the third workpiece gripping section 6 are positioned in the retracted position), and the first workpiece W1 is housed inside the first workpiece gripping section 4 (the arm section 4a that constitutes it). Next, with the piston rod 9a of the third fluid cylinder 9 still at its maximum extension, that is, with the third workpiece gripping section 6 in the retracted position, the piston rod 7a of the first fluid cylinder 7 is shortened to position the second workpiece gripping section 5 in the gripping position, thereby gripping the first workpiece W1 with the first workpiece gripping section 4 and the second workpiece gripping section 5.

[0029] In this manner, once the clamp unit 3 has finished gripping the first workpiece W1, the conveying device 1 is moved to the second position P2. When the conveying device 1 moves to (reaches) the second position P2, the piston rod 7a of the first fluid cylinder 7 is extended, releasing the first workpiece W1 gripped by the first workpiece gripping section 4 and the second workpiece gripping section 5. If the workpiece to be conveyed from the first position P1 to the second position P2 is still the first workpiece W1, the above operation is repeated.

[0030] On the other hand, if the workpiece to be transported from the first position P1 to the second position P2 changes from the first workpiece W1 to the second workpiece W2, for example, while the transport device 1 is moving from the second position P2 towards the first position P1, the piston rod 8a of the second fluid cylinder 8 is shortened, thereby positioning the second workpiece gripping section 5 in the retracted position shown in Figures 4 and 5. When the transport device 1 reaches the first position P1, the second workpiece W2 is housed inside the first workpiece gripping section 4 (or the arm section 4a that constitutes it). At this time, because the second workpiece gripping section 5 is in the retracted position, interference between the second workpiece gripping section 5 and the second workpiece W2 can be avoided. Next, the piston rods 9a of each third fluid cylinder 9 are shortened, positioning the third workpiece gripping section 6 in the gripping position, thereby gripping the second workpiece W2 with the first workpiece gripping section 4 and the third workpiece gripping section 6 (see Figures 4 and 5).

[0031] Once the clamp unit 3 has finished gripping the second workpiece W2, the conveying device 1 is moved to the second position P2. When the conveying device 1 has moved to (reached) the second position P2, the piston rod 9a of the third fluid cylinder 9 is extended, releasing the second workpiece W2 that was gripped by the first workpiece gripping section 4 and the third workpiece gripping section 6.

[0032] In the transport device 1 of this embodiment described above, by controlling the positions of the second work gripping section 5 and the third work gripping section 6 provided on the clamp unit 3 that grips the workpiece, it is possible to switch between a mode in which the first work gripping section 4 and the second work gripping section 5 cooperate to grip the workpiece (first workpiece W1) and a mode in which the first work gripping section 4 and the third work gripping section 6 cooperate to grip the workpiece (second workpiece W2, which has a different external shape from the first workpiece W1). Therefore, when transporting workpieces W1 and W2, it is not necessary to provide two dedicated transport devices.

[0033] Furthermore, since both the second workpiece gripping unit 5 and the third workpiece gripping unit 6 only move (reciprocate) between two positions, a gripping position and a retracted position, and there is no need to perform fine positional control with respect to the workpiece to be gripped and transported, inexpensive fluid cylinders can be used as the means for moving the second workpiece gripping unit 5 between the gripping position and the retracted position, and as the means for moving the third workpiece gripping unit 6 between the gripping position and the retracted position. Moreover, with fluid cylinders, switching between the first clamping mode for gripping the first workpiece W1 and the second clamping mode for gripping the second workpiece W2 can be performed easily and smoothly.

[0034] As described above, according to the present invention, a conveying device 1 capable of appropriately and smoothly conveying a first workpiece W1 and a second workpiece W2 having different external shapes can be realized at low cost, even in a production line with a short cycle time.

[0035] Furthermore, the first workpiece gripping section 4, the second workpiece gripping section 5, and the third workpiece gripping section 6 provided in the conveying device 1 of this embodiment all have claw sections 4b, 5b, and 6b that contact and support the workpieces (first workpiece W1 and second workpiece W2) from below. This reduces the possibility of the workpieces falling during conveyance as much as possible, thereby ensuring safe conveyance of the workpieces.

[0036] Although one embodiment of the present invention has been described above, the embodiments of the present invention are not limited thereto.

[0037] For example, depending on the external shape of the second workpiece W2, simply moving the cylinder rod 7a of the first fluid cylinder 7 to which the second workpiece gripping part 5 is attached to its maximum extension limit can avoid interference between the second workpiece gripping part 5 and the second workpiece W2 when the first workpiece gripping part 4 and the third workpiece gripping part 6 work together to grip the second workpiece W2. In that case, the second workpiece gripping part 5 and the second fluid cylinder 8 that supports the first fluid cylinder 7 which moves it horizontally in a vertical direction can be omitted. [Explanation of Symbols]

[0038] 1. Conveying device 2 Base section 3. Clamp unit (gripping means) 4. First workpiece gripping section 4b Claw part 5. Second workpiece gripping section 5b Claw part 6. Third workpiece gripping section 6b Claw part 7. First Fluid Cylinder 8. Second Fluid Cylinder 9. Third Fluid Cylinder P1 1st position P2 2nd position W1 First Work (Work) W2 Second Work (Work)

Claims

1. A conveying device for transporting a workpiece to a predetermined position, comprising a gripping means for gripping the workpiece during transport, The gripping means is, First workpiece gripping section, A second workpiece gripping unit moves between two positions: a gripping position in cooperation with the first workpiece gripping unit to grip the workpiece, and a retracted position in which it does not contact the workpiece. It has a third workpiece gripping portion which is positioned at a distance from the second workpiece gripping portion and moves between two positions: a gripping position in cooperation with the first workpiece gripping portion to grip the workpiece, and a retracted position in which it does not contact the workpiece. A conveying device characterized in that when the second workpiece gripping section is in the gripping position, the third workpiece gripping section is in the retracted position, and when the third workpiece gripping section is in the gripping position, the second workpiece gripping section is in the retracted position.

2. The conveying device according to claim 1, wherein each of the first workpiece gripping portion, the second workpiece gripping portion, and the third workpiece gripping portion has a claw portion that contacts and supports the workpiece from below.

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