Conveying device

Abstract

To provide a conveying device that can safely transport materials while minimizing fluctuations in conveying speed and maintaining the quality of the transported items. [Solution] The conveying device 1 conveys objects made of flexible material having an opening from a stacked conveying source to a conveying destination. The conveying device 1 comprises an articulated robot 10, a force sensor 20 disposed at the tip of the articulated robot 10, an end effector 30 disposed on the articulated robot 10 via the force sensor 20 and having a gripping part 31 provided with a hook-shaped hooking part 31A, and a control unit 40 that controls the articulated robot 10 and operates it to hook the hooking part 31A into the opening, lift the object, and convey it.

Description

Technical Field

[0001] The present invention relates to a conveying device that conveys a conveyed object having an opening from a stacked conveying source to a conveying destination.

Background Art

[0002] In vehicle manufacturing, as an assembly preparation process, for example, there is a process of lifting stacked dash silencers one by one and hanging them on a parts shelf. Conventionally, workers manually lifted the dash silencers one by one and conveyed them to the parts shelf. However, when conveyed by workers, there were problems such as safety issues and unevenness in the conveying speed.

[0003] Also, for example, in Patent Document 1, regarding a kneaded material transfer device that grips and transfers a kneaded material of fibers and a thermoplastic resin, it is described that it has a plurality of needle-like members and grips the kneaded material by piercing the needle-like members into the kneaded material. However, in the device described in Patent Document 1, since the needle-like members are pierced into the conveyed object for gripping, there is a problem that the needles may bend or break when piercing the needle-like members. Furthermore, since the needle-like members are pierced into the conveyed object, holes are formed in the conveyed object, resulting in quality problems.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been made based on such problems, and an object thereof is to provide a conveying device that can reduce unevenness in conveying speed, maintain the quality of the conveyed object, and convey it safely.

Means for Solving the Problems

[0006] The present invention relates to a conveying device for transporting objects made of a flexible material having an opening from a stacked conveying source to a conveying destination, and comprises an articulated robot, a force sensor disposed at the tip of the articulated robot, an end effector disposed on the articulated robot via the force sensor and having a gripping portion with a hook-shaped hooking part, and a control unit that controls the articulated robot and operates it to hook the hooking part into the opening, lift the object, and transport it. [Effects of the Invention]

[0007] According to the present invention, since the transported object is transported by controlling a multi-joint robot, it is highly safe and can be transported at a fixed speed. Furthermore, since the object is transported by hooking it onto the opening with a hooking part, the quality of the transported object can be maintained without puncturing it. Moreover, since the object is removed from the opening with a hook-shaped hooking part, it has high tolerance for variations in the position of the opening and the hooking part, and the accuracy of removing stacked transported objects can be improved.

[0008] Furthermore, by lowering the gripping part at an angle with the hooking part facing downwards, bringing it into contact with the periphery of the opening, and then raising the gripping part by a predetermined amount, it is possible to target the gaps between stacked transported items and remove them with high precision. Moreover, by moving the gripping part diagonally upwards after raising it by a predetermined amount, the transported items can be removed at the predetermined position even if the positions of the opening and the hooking part vary.

[0009] In addition, by hooking the hook into the opening and then rotating the hook horizontally with the rotation axis in the direction of rotation while raising the hook, the conveyed object can be lifted while being turned over. This prevents the conveyed object from getting caught on the stacked objects below it, even if the object has an uneven shape, and allows it to be easily removed.

[0010] Furthermore, if the movement of the articulated robot is controlled based on the detection results from the presence confirmation laser sensor and the force sensor when transporting an object, it will be possible to detect and respond to the object even if it is swaying due to wind or other factors and cannot be detected by the presence confirmation laser sensor, or if the object is too light to be detected by the force sensor. [Brief explanation of the drawing]

[0011] [Figure 1] This diagram shows the overall configuration of a transport device according to one embodiment of the present invention. [Figure 2] This diagram shows an enlarged view of the gripping mechanism shown in Figure 1. [Figure 3] Figure 1 is a diagram illustrating the operation of the conveying device. [Figure 4] Another diagram illustrating the operation of the conveying device shown in Figure 1. [Figure 5] This is yet another diagram illustrating the operation of the conveying device shown in Figure 1. [Figure 6] This is yet another diagram illustrating the operation of the conveying device shown in Figure 1. [Figure 7] This is yet another diagram illustrating the operation of the conveying device shown in Figure 1. [Figure 8] This is yet another diagram illustrating the operation of the conveying device shown in Figure 1. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0013] Figure 1 shows the configuration of a conveying device 1 according to one embodiment of the present invention. Figure 2 shows a magnified view of a part of the conveying device 1. Figures 3 to 8 show the operation of the conveying device 1.

[0014] This conveying device 1 transports objects M, which have an opening M1 and are made of a flexible material, from a stacked source to a destination. The objects M are preferably thin sheets. The materials constituting the objects M include, for example, at least one of the group consisting of fibers and resins; specifically, plastics, fiber-reinforced plastics, or felt are preferred. Specific examples of objects M include interior materials such as dash silencers. The conveying device 1 is configured to use the opening M1 of the objects M to take out the stacked objects M from the top and transport them one by one.

[0015] The transport device 1 comprises an articulated robot 10, a force sensor 20 disposed at the tip of the articulated robot 10, an end effector 30 disposed on the articulated robot 10 via the force sensor 20, and a control unit 40 that controls and operates the articulated robot 10. The articulated robot 10 is a type of industrial robot that has an articulated structure and can move its arm freely like a human arm. Figure 1 shows a 6-axis collaborative robot as an example of an articulated robot 10. In addition, if the transport source and the transport destination are far apart, a means of transport (not shown) may be provided to move the articulated robot 10 between the transport source and the transport destination. The force sensor decomposes forces and torques applied from various directions into components in the X, Y, and Z directions and detects them by converting them into electrical signals.

[0016] The end effector 30 has, for example, a gripping portion 31 in which a hook-shaped hooking portion 31A is provided at the tip of a shaft member 31B. The gripping portion 31 hooks and grips the opening M1 of the conveyed object M with the hooking portion 31A and is disposed with respect to the support member 32. The hooking portion 31A is preferably formed, for example, in a wedge shape or a U shape in which the end portion of the shaft member 31B is folded back, and the folded-back side (i.e., the tip side) is made narrower than the folded-back end portion side and the folded-back side is rounded. The width W between the folded-back end portion of the hooking portion 31A and the shaft member 31B is preferably, for example, thinner than the thickness of the conveyed object M. This is because when gripping the conveyed object M, the conveyed object M is crushed and inserted and gripped between the widths W.

[0017] The shaft member 31B is constituted by, for example, a rod-shaped member, and the side on the folded-back side of the shaft member 31B is preferably extended linearly. By inclining the gripping portion 31 with the hooking portion 31A downward with respect to the opening M1 and bringing the shaft member 31B into contact with the peripheral edge of the opening M1, and then moving it obliquely upward along the length direction of the side on the folded-back side of the shaft member 31B, the opening M1 can be easily hooked by the hooking portion 31A. The shaft member 31B is preferably provided with, for example, a reinforcing member 31C for reinforcing on the side opposite to the folded-back side.

[0018] The length L1 of the shaft member 31B is preferably, for example, 20 mm or more. By making the length of the shaft member 31B somewhat long, it is possible to cope even if the positions of the opening M1 and the hooking portion 31A vary. The length of the shaft member 31B is the length obtained by subtracting the length of the hooking portion 31A from the length of the gripping portion 31. The length L2 of the hooking portion 31A is the length from the tip of the gripping portion 31 to the folded-back end portion of the hooking portion 31A, and is preferably, for example, 5 mm or more and 20 mm or less.

[0019] The end effector 30 also preferably has, for example, a distance sensor 33 that detects the distance to the conveyed object M, imaging means 34 such as a camera that images the conveyed object M, and a presence confirmation laser sensor 35 that detects that the conveyed object M is present at the position where it is hooked on the hooking part. The distance sensor 33 is, for example, for detecting that it has approached a certain distance when the gripping part 31 is brought close to the conveyed object M at the conveying source. Examples of the distance sensor 33 include those that measure the distance to the conveyed object M by irradiating the conveyed object M with light such as laser light in an arbitrary linear range and measuring the time until the light returns. The imaging means 34 images the conveyed object M at the conveying source and is for adjusting the position of the gripping part 31 with respect to the opening M1. The presence laser sensor 35 recognizes distance values and detects at an arbitrary distance by setting a threshold value for the distance values. Examples of the presence laser sensor 35 include those that measure the distance to the conveyed object M by irradiating the conveyed object M with light such as laser light in an arbitrary linear range and measuring the time until the light returns.

[0020] The control unit 40 is constituted by, for example, a computer and controls and operates the multi-joint robot by executing a program. Specifically, the control unit 40 has, for example, an approach operation control means 41 that brings the gripping part 31 close to the conveyed object M at the conveying source, a position correction operation control means 42 that corrects the position of the gripping part 31 with respect to the opening M1 after bringing the gripping part 31 close to the conveyed object M at the conveying source, a hooking operation control means 43 that hooks the hooking part 31A on the opening M1, a lifting operation control means 44 that lifts the conveyed object M by the hooking part 31A after hooking the opening M1 by the hooking part 31A, a conveying operation control means 45 that conveys the conveyed object M to the conveying destination after lifting the conveyed object M by the hooking part 31A, and an origin reset operation control means 46 that returns the gripping part 31 to the origin position after conveying the conveyed object M to the conveying destination.

[0021] The approach motion control means 41 is configured, for example, to control the articulated robot 10 to move the gripping unit 31 from its origin position to the vicinity of the transported object M detected by the distance sensor 33. Specifically, for example, as shown in Figure 3, it is preferable that the origin position of the gripping unit 31 is set above the stacked transported objects M at the transport source, and that the articulated robot 10 is controlled to lower the gripping unit 31 from the origin position until the distance sensor 33 detects the transported object M.

[0022] The position correction operation control means 42 is preferably configured to correct the position of the gripping portion 31 by aligning the hooking portion 31A with the opening M1, based on the acquired image obtained by the imaging means 34, as shown in Figure 4. Alternatively, the position correction operation control means 42 may be configured to control the articulated robot 10 to raise the imaging means 34 to the imaging position when the imaging means 34 is imaging the transported object M.

[0023] Preferably, the hooking motion control means 43 controls the articulated robot 10 to tilt the gripping portion 31 relative to the opening M1 with the hooking portion 31A facing downwards, lowers the hooking portion 31A in accordance with the opening M1, and, as shown in Figure 5, brings the gripping portion 31 into contact with the periphery of the opening M1. Then, as shown in Figure 6, raises the gripping portion 31 by a predetermined amount, and then moves the gripping portion 31 diagonally upward to hook the hooking portion 31A onto the opening M1. Whether the gripping portion 31 has come into contact with the periphery of the opening M1 is detected by the force sensor 20, and the hooking motion control means 43 controls the articulated robot 10 based on the signal from the force sensor 20.

[0024] For example, the shaft member 31B is brought into contact with the periphery of the opening M1. Specifically, it is preferable to bring the folded side of the shaft member 31B into contact with the opening. The reason for raising the gripping portion 31 by a predetermined amount after bringing it into contact with the periphery of the opening M1 is that the gripping portion 31 would sink in because the conveyed object M is flexible (see Figure 5). Therefore, by raising the gripping portion 31, it is possible to target the gaps between the stacked conveyed objects M. When moving the gripping portion 31 diagonally upward, it is preferable to move it in the direction of the length of the folded side of the shaft member 31B (see Figure 6). Moving it in this way is preferable because it allows the conveyed object M to be removed at a predetermined position even if the positions of the opening M1 and the hooking portion 31A vary.

[0025] Preferably, the lifting motion control means 44 is configured to control, for example, the articulated robot 10 to raise the hook portion 31A while rotating it horizontally with the rotation axis as the axis of rotation, as shown in Figure 7, thereby lifting the conveyed object M while flipping it over. This is to ensure that even if the conveyed object M has an uneven shape, it can be removed without getting caught on the lower conveyed object M in a stack.

[0026] When rotating the hook portion 31A, the rotation axis direction and rotation angle in the horizontal plane are preferably adjusted according to, for example, the shape of the conveyed object M, the distance between the articulated robot 10 and the conveyed object M, and the number of stacked conveyed objects M. In the horizontal plane, if the direction connecting the hook portion 31A and the articulated robot 10 is the Y-axis direction, and the direction perpendicular to the Y-axis direction is the X-axis direction, then the rotation axis direction of the hook portion 31A may be the X-axis direction, the Y-axis direction, or a combination of the components in the X-axis direction and the Y-axis direction. Furthermore, it is preferable to rotate the hook portion 31A with the folded end side facing the direction of rotation.

[0027] Preferably, the transport operation control means 45 is configured to change, for example, the set load and set center of gravity of the articulated robot 10, and after lifting the transport object M to a predetermined position as shown in Figure 8, move the articulated robot 10 to transport the transport object M to the destination. In this case, it is preferable that the transport operation control means 45 controls the operation of the articulated robot 10 based on, for example, the detection result from the presence confirmation laser sensor 35 and the detection result from the force sensor 10. Specifically, it is preferable that if the transport object M is detected by at least one of the presence confirmation laser sensor 35 and the force sensor 10, the transport operation is continued, and if the transport object M is not detected by either, the transport operation is terminated, as it is determined that the transport object M is not being grasped. This is because the presence confirmation laser sensor 35 alone may not be able to accurately detect the transport object M if it is swaying due to wind, etc., and the force sensor 20 alone may not be able to accurately detect the transport object M if it is light.

[0028] Preferably, the origin return motion control means 46 is configured to control the articulated robot 10, for example, to change the set load and set center of gravity of the articulated robot 10 after the transported object M has been placed at the transport destination, and to return the gripping part 31 to the origin position.

[0029] The transport device 10 operates, for example, as follows, to transport objects M one by one from the transport source to the transport destination. First, for example, as shown in Figure 3, the articulated robot 10 is controlled by the approach motion control means 41 to lower the gripping unit 31 from the origin position until the distance sensor 33 detects the object M. Next, for example, as shown in Figure 4, the articulated robot 10 is controlled by the position correction motion control means 42 to raise the imaging means 34 to the shooting position, the imaging means 34 takes an image of the object M, and based on the obtained image, the position of the gripping unit 31 is corrected by aligning the hooking unit 31A with the opening M1 of the object M.

[0030] Next, for example, as shown in Figure 5, the articulated robot 10 is controlled by the hooking motion control means 43 to tilt the gripping portion 31 relative to the opening M1 with the hooking portion 31A facing downwards, and the hooking portion 31A is lowered in correspondence with the opening M1. After that, when the force sensor 20 detects that the gripping portion 31 has come into contact with the periphery of the opening M1, as shown in Figure 6, the gripping portion 31 is raised by a predetermined amount, and then the gripping portion 31 is moved diagonally upward to hook the hooking portion 31A onto the opening M1. Specifically, for example, it is preferable to bring the folded side of the shaft member 31B into contact with the periphery of the opening M1, raise it by a predetermined amount, and then move it diagonally upward along the length direction of the folded side of the shaft member 31B.

[0031] Next, for example, as shown in Figure 7, the lifting motion control means 44 controls the articulated robot 10 to raise the hooking part 31A and rotate it horizontally with the rotation axis as the axis of rotation, lifting the conveyed object M by a predetermined amount while flipping it over.

[0032] Next, for example as shown in Figure 8, the transport operation control means 45 changes the set load and set center of gravity of the articulated robot 10, lifts the transport object M to a predetermined position, and moves the articulated robot 10 to transport the transport object M to the destination. At this time, the transport operation control means 45 preferably determines that it is gripping the transport object M and continues the transport operation if it detects the transport object M based on the detection result of the presence confirmation laser sensor 35 and the detection result of the force sensor 10, for example, if it detects the transport object M with at least one of them, and if it does not detect the transport object M with either, it preferably determines that it is not gripping the transport object M and terminates the transport operation.

[0033] Next, the origin return motion control means 46 controls, for example, the articulated robot 10 to place the transported object M at the transport destination, then changes the set load and set center of gravity of the articulated robot 10 to return the gripping unit 31 to the origin position.

[0034] As described above, this embodiment allows for the transport of the object M by controlling the articulated robot 10, thus ensuring high safety and enabling transport at a fixed speed. Furthermore, since the object M is transported by hooking the opening M1 with the hooking part 31A, the quality of the object M can be maintained without puncturing it. Moreover, because the object is removed from the opening M1 using the hook-shaped hooking part 31A, it has high tolerance for positional variations between the opening M1 and the hooking part 31A, improving the accuracy of removing stacked objects M.

[0035] Furthermore, by lowering the gripping portion 31 with the hooking portion 31A facing downwards and tilting it, and then raising the gripping portion 31 by a predetermined amount after it has come into contact with the periphery of the opening M1, it is possible to target the gaps between the stacked transported objects M, and the transported objects M can be removed with high precision. Moreover, if the gripping portion 31 is moved diagonally upward after being raised by a predetermined amount, the transported objects can be removed at a predetermined position even if the positions of the opening M1 and the hooking portion 31A vary.

[0036] In addition, by hooking the hook portion 31A onto the opening M1 and then rotating the hook portion 31A horizontally with the rotation axis as the axis of rotation while raising it, the conveyed object M can be lifted while being turned over. This prevents the conveyed object M from getting caught on the lower conveyed object M in the stack, even if the conveyed object M has an uneven shape, and allows it to be easily removed.

[0037] Furthermore, if the operation of the articulated robot 10 is controlled based on the detection results from the presence confirmation laser sensor 35 and the force sensor 20 when transporting the transported object M, then even if the transported object M is swaying due to wind or other factors and cannot be detected by the presence confirmation laser sensor 35, or if the transported object M is light and cannot be detected by the force sensor 20, the transported object M can still be detected and addressed.

[0038] The present invention has been described above with reference to embodiments, but the present invention is not limited to the above embodiments and can be modified in various ways. For example, although each component was described in detail in the above embodiments, the specific structure and shape of each component may differ, and the present invention does not have to include all of the above-mentioned components, but may include other components as well. [Explanation of symbols]

[0039] 1...Transportation device, 10...Articulated robot, 20...Force sensor, 30...End effector, 31...Gripping part, 31A...Hooking part, 31B...Axis member, 31C...Reinforcement member, 32...Support member, 33...Distance sensor, 34...Imaging means, 35...Laser sensor for presence confirmation, 40...Control unit, 41...Approach motion control means, 42...Position correction motion control means, 43...Hooking motion control means, 44...Lifting motion control means, 45...Transportation motion control means, 46...Origin return motion control means, M...Transported object, M1...Opening

Claims

1. A conveying device that transports objects made of a flexible material having an opening from a stacked conveying source to a conveying destination, Articulated robots and A force sensor is provided at the tip of the aforementioned articulated robot, An end effector is provided on the articulated robot via the force sensor, and has a gripping portion with a hook-shaped hooking part. A control unit that controls the articulated robot and operates it to hook the hooking part into the opening, lift the object to be transported, and transport it. A conveying device characterized by being equipped with the following features.

2. The control unit controls the articulated robot to tilt the gripping portion so that the hooking portion is facing downwards, lower the hooking portion so that it is in contact with the opening, bring the gripping portion into contact with the periphery of the opening, raise the gripping portion by a predetermined amount, and then move the gripping portion diagonally upwards so that the hooking portion is hooked onto the opening. The conveying device according to claim 1.

3. The control unit controls the articulated robot to hook the hooking part into the opening, and then rotate the hooking part horizontally with the rotation axis in the direction of rotation while raising it, thereby lifting the conveyed object while flipping it over. The conveying device according to claim 1.

4. The end effector has a laser sensor for presence confirmation that detects whether the transported object is in a position where it is hooked onto the hooking part. The control unit controls the operation of the articulated robot when transporting the transported object, based on the detection result of whether or not the transported object is present by the presence confirmation laser sensor and the detection result of the load of the transported object by the force sensor. The conveying device according to claim 1.

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