Transfer device

Abstract

The present invention provides a transfer device (100) comprising a hook (110) and a forward / backward device (120) for moving the hook (110) forward and backward. The device includes: a hook drive (130) that is a drive source for moving the hook (110) between an engaged position and a retracted position; a forward / backward drive (140) for moving the forward / backward device (120) forward and backward; and a drive control (150) for controlling the hook drive (130) and the forward / backward drive (140). The drive control (150) includes: a hook position determination unit (151) for determining the hook position based on a position threshold; a hook (110) control unit for stopping the hook (110) when an overload of the hook drive (130) is detected; and a forward / backward drive control unit (153) for moving the hook (110) forward and backward when the hook position obtained is above the position threshold, provided that the hook (110) has been stopped by the hook (110) control unit.

Description

Technical Field

[0001] The present invention relates to a transfer device for moving goods from a designated holding part to another holding part. Background Technology

[0002] Conventional transfer devices, such as those described in Patent Document 1, exist that transfer goods by moving a hook that engages with the goods forward and backward. In such devices, if the hook does not engage accurately with the goods, an overload of the drive motor that drives the hook is detected and treated as an error. In the event of an overload error, the transfer device is stopped, the condition is checked, and maintenance is performed as needed.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-52600 Summary of the Invention

[0006] However, the inventors discovered that even in the event of an overload error, the hook sometimes engages fully with the cargo and is able to transfer it.

[0007] This invention is based on the inventors’ insights and aims to provide a transfer device that can continue the transfer operation even in the event of an overload error.

[0008] To achieve the above objectives, a transfer device according to the present invention includes a hook that engages with cargo and a forward / backward device that moves the hook forward or backward. The device comprises: a hook drive unit, which is a drive source for moving the hook between an engaged position and a retracted position; a forward / backward drive unit, which is a drive source for the forward / backward device; and a drive control unit that controls the hook drive unit and the forward / backward drive unit. The drive control unit includes: a hook position determination unit that obtains the position of the hook (i.e., the hook position) and determines the hook position based on a position threshold; a hook control unit that controls the hook drive unit such that the hook stops when an overload of the hook drive unit is detected; and a forward / backward drive unit that, when the hook control unit stops the hook drive unit, controls the forward / backward drive unit to move the hook forward or backward if the obtained hook position is above the position threshold.

[0009] Effects of the invention: According to the present invention, even in the event of an overload error, the drive control device can determine the position of the hook and continue the transfer operation. Attached Figure Description

[0010] Figure 1 It is a perspective view showing the transfer device, the holding part, and the cargo together.

[0011] Figure 2 It is a block diagram representing the functional structure of the transfer device.

[0012] Figure 3 It is a flowchart representing the processing flow of the drive control device.

[0013] Figure 4 This is another example of a hook and a hook drive mechanism. Detailed Implementation

[0014] Hereinafter, embodiments of the transfer device of the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below are examples provided for illustrative purposes and are not intended to limit the invention. For example, the shapes, structures, materials, constituent elements, relative positional relationships, connection states, numerical values, formulas, the content of each stage in the method, and the order of each stage shown in the following embodiments are examples, and sometimes include content not described below. In addition, sometimes geometric representations such as parallelism and orthogonality are used, but these representations do not indicate mathematical rigor and include substantially permissible errors and deviations. Furthermore, representations such as simultaneous and identical also include substantially permissible ranges.

[0015] Furthermore, the accompanying drawings are schematic diagrams that have been appropriately emphasized, omitted, or proportionally adjusted for the purpose of illustrating the invention, and differ from the actual shapes, positional relationships, and proportions.

[0016] Furthermore, several inventions are sometimes described in general terms as a single embodiment. Additionally, a portion of the content described below is explained as any constituent element relating to this invention.

[0017] Figure 1 It is a perspective view showing the transfer device, the holding part, and the cargo together. Figure 2 This is a block diagram illustrating the functional configuration of the transfer device. The transfer device 100 is a device for transferring goods 200 between the first holding part 300 and the second holding part 101, and includes a hook 110, a forward / backward device 120, a hook drive device 130, a forward / backward drive device 140, a drive control device 150, and a position sensor 160. In this embodiment, the transfer device 100 is a device that transfers goods 200 while sliding on the first holding part 300 and the second holding part 101. The transfer device 100 is, for example, installed on a stacker crane, a traveling vehicle, or other conveying device (not shown) capable of transporting goods 200.

[0018] The cargo 200 is a part of the cargo 200 held in a device different from the transfer device 100, or a part of the cargo 200 held in a support or other device, namely the first holding part 300, and is an object that is transferred between the first holding part 300 and the second holding part 101, and has a locking part 210 that is suitable for the hook 110 provided by the transfer device 100.

[0019] The engaging portion 210 is a part of the cargo 200 that is disposed at a predetermined distance from the outer surface 220 of the surface intersecting the transfer direction (Y-axis direction in the figure) toward the outer side (Y-side in the figure) of the transfer direction. It is the portion that engages with the hook 110 of the transfer device 100 in the transfer direction and is subjected to a force for transferring the cargo 200 by the hook 110. In this embodiment, the engaging portion 210 is integrally disposed on the outer surface 220 of the cargo 200, and the two engaging portions 210 are symmetrically arranged. Alternatively, the cargo 200 may not have a specially shaped engaging portion 210; the front end surface, rear end surface, etc., may function as engaging portions 210.

[0020] The second holding part 101 is provided in the transfer device 100 and is the part that holds the goods 200. In this embodiment, the second holding part 101 corresponds to the first holding part 300 and is a plate-shaped part that holds the goods 200 in a mounted state, holding the two ends of the goods 200 in the width direction from below.

[0021] The hook 110 is a component that engages with the engaging portion 210 of the cargo 200, and moves between an engaged position and a retracted position. In this embodiment, the hook 110 is inserted between the engaging portion 210 of the cargo 200 by rotating about a rotation axis along the transfer direction (Y-axis direction in the figure), and applies a force to the engaging portion 210 for transferring the cargo 200. The transfer device 100 includes two hooks 110 that are symmetrically arranged in the YZ plane in the figure, and rotate in opposite directions. Furthermore, the transfer device 100 arranges the symmetrical hooks 110 in the transfer direction. Thus, cargo 200 disposed on either side in the transfer direction can be transferred.

[0022] The forward / reverse device 120 is a device that moves the hooks 110 forward or backward in the transfer direction. It is a device that can reciprocate the cargo 200 in the transfer direction via the hooks 110 engaged with the engaged portion 210 or the outer surface portion 220 of the cargo 200. In this embodiment, the forward / reverse device 120 moves all four hooks 110 reciprocally in the transfer direction simultaneously. The forward / reverse device 120 also moves the hook drive device 130 reciprocally along with the hooks 110. Specifically, for example, the forward / reverse device 120 includes a track that guides the hooks 110 in the transfer direction and a linear motion unit that moves them reciprocally.

[0023] The hook drive device 130 is a device that moves the hook 110 between an engaged position and a retracted position that engages with the engaged portion 210, and it includes a motor. In this embodiment, the hook drive device 130 is connected to the four hooks 110 via a conversion mechanism composed of mechanical elements, and one hook drive device 130 can cause the four hooks 110 to rotate and swing symmetrically at the same time.

[0024] The type of hook drive device 130 is not particularly limited, but in this embodiment, the hook drive device 130 includes a servo amplifier, a servo motor driven by the servo amplifier, a reducer, etc.

[0025] The forward / backward drive device 140 is a drive unit that moves the forward / backward device 120 forward or backward. The type of forward / backward drive device 140 is not particularly limited, but in this embodiment, similar to the hook drive device 130, the forward / backward drive device 140 includes a servo amplifier, a servo motor driven by the servo amplifier, a reducer, etc.

[0026] The position sensor 160 is a sensor that detects the position of the hook 110, including both the engaged and retracted positions, between the engaged and retracted positions. The type of position sensor 160 is not particularly limited, but in this embodiment, an optical encoder is used. The position sensor 160 is mounted on a shaft connected to the two hooks 110 arranged in the transfer direction. Alternatively, the position sensor 160 may be a potentiometer, a demultiplexer, or a sensor included in a servo motor, i.e., the hook drive device 130.

[0027] The drive control device 150 is a device that controls the hook drive device 130 and the forward / backward drive device 140 to cause the hook 110 and the forward / backward device 120 to perform predetermined actions. As a processing unit implemented by executing a program by a processor, it includes a hook position determination unit 151, a hook control unit 152, and a forward / backward drive device control unit 153. In this embodiment, the drive control device 150 includes an abnormality notification unit 154.

[0028] The hook position determination unit 151 is a processing unit that obtains the position of the hook 110 from the position sensor 160, i.e., the hook position, and determines whether the hook position is above or below a position threshold. Here, "above or below the position threshold" means that the hook 110 is in the engaged position, and "below the position threshold" means that the hook 110 is in the retracted position. In this embodiment, the hook position determination unit 151 obtains the hook position at a predetermined resolution based on the information obtained from the position sensor 160, for example, setting the case of being in the retracted position to 0 and the case of being in the engaged position to 255, and determines whether the hook position is above or below the position threshold. If the hook position is above or below the position threshold, the hook position determination unit 151 determines that the hook 110 is in the engaged position; if the hook position is below the position threshold, it determines that the hook 110 is in the retracted position. The position threshold, which serves as the determination criterion for the hook position determination unit 151, is not limited, and is a value derived empirically, for example, that allows the hook 110 to be moved even when it is not in the engaged position but can engage with the engaged part 210 by a sufficient amount. Furthermore, even when the value output by the position sensor 160 is reversed, such as setting the value to 255 when the position is closest to the retraction position and setting the value to 0 when the position is closest to the engagement position, the hook position determination unit 151 determines that the position is above the position threshold when the hook position is numerically less than the position threshold because the hook 110 is in the engagement position, and determines that the position is below the position threshold when the hook position is numerically above the position threshold because the hook 110 is in the retraction position.

[0029] The hook control unit 152 controls the hook drive device 130 so that when an overload is detected in the hook drive device 130 as the hook 110 moves from the retracted position to the engaged position, the hook 110 stops. In this embodiment, the servo amplifier included in the hook drive device 130 outputs overload information when the load exceeds a first load threshold, causing the servo motor to stop abnormally and thus stopping the hook 110. The hook control unit 152 obtains load information related to the load from the hook drive device 130, detects overload based on a second load threshold lower than the first load threshold and the obtained load information, and controls the hook drive device 130 so that the hook 110 stops before the overload information is obtained. Specifically, the hook control unit 152 stops the hook 110 by instructing the servo motor to stop moving in its direction. As described above, the hook control unit 152 can stop the movement of the hook 110 before a large load is applied to the hook drive device 130. The load information is information related to the torque of the servo motor, such as information about the current value based on the current supplied to the servo motor by the servo amplifier.

[0030] Furthermore, when the hook control unit 152 stops the hook drive device 130, if the hook position determination unit 151 determines that the hook position is less than the position threshold, the hook drive device 130 is controlled so that the hook 110 moves to the retraction position.

[0031] Furthermore, the preferred hook control unit 152 controls the hook drive device 130 to stop the hook 110 when the load information duration exceeds a second load threshold. This eliminates stops caused by momentary increases in load information and enables stable control of the hook 110.

[0032] When the hook control unit 152 stops the hook drive unit 130, and the hook position determined by the hook position determination unit 151 is above a position threshold, the forward / backward drive unit 153 controls the forward / backward drive unit 140 based on the transfer information while maintaining the stopped state of the hook 110, so that the hook 110 moves forward or backward. Therefore, the cargo 200 can be transferred even when the hook 110 has not reached the engagement position.

[0033] Furthermore, if the hook position determination unit 151 determines that the hook position obtained when the hook control unit 152 stops the hook drive device 130 is less than the position threshold, after controlling the hook drive device 130 to move the hook 110 to the retracted position, the forward / reverse drive device control unit 153 controls the forward / reverse drive device 140 based on the transfer information to make the hook 110 move forward or backward. As a result, the cargo 200 remains untransferred, and the hook 110 retracts and exits from the first holding part 300.

[0034] If the hook position determination unit 151 determines that the hook position obtained when the hook control unit 152 stops the hook drive device 130 is less than a position threshold, the abnormality notification unit 154 notifies an abnormality. The method of notifying the abnormality is not particularly limited; for example, the abnormality information can be output to a host computer. Alternatively, the abnormality information can be notified to the user via sound, light, text, images, etc.

[0035] Next, the processing flow of the drive control device 150 will be explained. Figure 3 This is a flowchart illustrating the processing flow of the drive control device. Additionally, Figure 3 The flowchart shown is one example. Even if the processing order is different, multiple processes are merged, or a process is separated, the processing flow may be different, and such differences may sometimes be included in the embodiments of the present invention. The forward and backward drive device control unit 153 controls the forward and backward drive device 140 based on the acquired transfer information to position the hook 110 in the retraction position relative to the engaged portion 210 of the cargo 200 (S101). When the hook 110 is positioned in the retraction position, the hook control unit 152 controls the hook drive device 130 to move the hook 110 toward the engaged position.

[0036] The hook position determination unit 151 obtains the position of the hook 110 based on information from the position sensor 160. If it determines that the hook 110 has not reached the engagement position (S103, "No"), the hook control unit 152 obtains torque-related load information from the hook drive device 130 and determines whether a second load threshold is exceeded (S104). If the load information is less than the second load threshold (S104, "No"), it returns to confirming the position of the hook 110 (S103). If the load information is above the second load threshold (S104, "Yes"), the hook position determination unit 151 determines whether the load information exceeds the second load threshold for a duration threshold (S105). If the load information does not exceed the second load threshold for a duration threshold (S105, "No"), it returns to confirming the position of the hook 110 (S103).

[0037] If the load information duration exceeds the second load threshold (S105, "Yes"), the hook control unit 152 controls the hook drive device 130 to stop the movement of the hook 110 (S106). In this state, the hook control unit 152, for example, performs control to stop the servo motor from moving in its direction, but is in a state where it can further control the hook drive device 130 to move the hook 110. In addition, the hook control unit 152 saves an overload stop log (S107). The content of the overload stop log is not limited, and for example, it can show the value of the last detected additional information (torque), the stopping position of the hook 110, etc.

[0038] Next, the hook position determination unit 151 determines whether the hook position obtained from the position sensor 160 is above or below a position threshold (S108). If the hook position is above or below the position threshold (S108, "Yes"), while the hook control unit 152 maintains the stopped position of the hook 110, the forward / backward drive device control unit 153 drives the forward / backward drive device 140 based on the transfer information to transfer the cargo 200 (S109). On the other hand, if the hook position is below the position threshold (S108, "No"), the hook control unit 152 controls the hook drive device 130 to move the hook 110 to a retracted position (S110). When the hook 110 reaches the retracted position, the forward / backward drive device control unit 153 controls the forward / backward drive device 140 to position the hook 110 and the forward / backward device 120 in a maintainable position (S111). The abnormality notification unit 154 notifies the abnormality information (S112). The abnormality information may also include the contents of the log saved in step S107.

[0039] Additionally, when an anomaly is reported, the equipment equipped with the transfer device 100 may sometimes stop operating and undergo maintenance. Alternatively, the transfer of only the target cargo 200 may be suspended, while the transfer of other cargo 200 continues.

[0040] According to the embodiment of the transfer device 100, even if the hook 110 stops due to overload, it determines whether to transfer the goods 200 based on the position where the hook 110 stops. Therefore, it can suppress the number of stops of the transfer device 100 and the equipment equipped with the transfer device 100, and can improve the transfer efficiency of the goods 200.

[0041] Furthermore, before the servo amplifier and other devices in the hook drive unit 130 detect overload based on the first load threshold and cause the hook 110 to stop abnormally, the hook control unit 152 detects overload in software based on a second load threshold that is lower than the first load threshold. Therefore, the forced stop time of the hook 110 by the servo amplifier and other devices can be reduced, and the recovery time can be shortened.

[0042] Furthermore, by moving the forward / backward device 120 to a position where maintenance is possible and notifying of any abnormalities, the time required for recovery maintenance can be reduced.

[0043] Furthermore, the present invention is not limited to the embodiments described above. For example, the constituent elements described in this specification can be combined arbitrarily. In addition, other embodiments implemented by excluding several constituent elements are also considered as embodiments of the present invention. Furthermore, modifications made by those skilled in the art to the above embodiments without departing from the spirit of the present invention, i.e., the meaning of the statements described in the patent claims, are also included in the present invention.

[0044] For example, the retraction device 120 may have a telescopic arm, with a hook 110 mounted at the end of the arm. Alternatively, the arm may be inserted to the side of the cargo 200, the hook 110 may be hooked onto the rear end face of the cargo 200, and the cargo 200 may be transferred from the first holding part 300 to the second holding part 101 by retracting the arm; or the hook 110 may be hooked onto the front end face of the cargo 200, and the cargo 200 may be transferred from the second holding part 101 to the first holding part 300 by advancing the arm.

[0045] Alternatively, hook 110 can rotate not only about a rotation axis along the transfer direction (Y-axis direction in the figure), but also... Figure 4 It rotates about a rotation axis 139 that extends vertically, as shown. Alternatively, the hook 110 can move in a straight line without rotating.

[0046] Furthermore, the cargo 200 can be applied not only to cargo 200 held in a mounted state, but also to cargo 200 held in any holding state, such as in a suspended state.

[0047] Industrial availability

[0048] This invention can be applied to transfer devices for moving goods in automated warehouses, logistics hubs, picking systems, and other similar applications.

[0049] Symbol explanation:

[0050] 100: Transfer device; 101: Second holding part; 110: Hook; 120: Forward and backward device; 130: Hook drive device; 139: Rotary shaft; 140: Forward and backward drive device; 150: Drive control device; 151: Hook position judgment unit; 152: Hook control unit; 153: Forward and backward drive device control unit; 154: Abnormal notification unit; 160: Position sensor; 200: Cargo; 210: Engaged part; 220: Outer surface part; 300: First holding part.

Claims

1. A transfer device comprising a hook for engaging with cargo and a forward / backward device for advancing or retracting the hook, characterized in that, have: The hook drive device is a drive source that moves the hook between the engaged position and the retracted position. The forward / reverse drive device is the drive source for the aforementioned forward / reverse device; and The drive control device controls the hook drive device and the forward / reverse drive device. The aforementioned drive control device includes: The hook position determination unit obtains the position of the hook, i.e., the hook position, and determines whether the hook position is above a predetermined position threshold. The position threshold is a value in which the hook is not in the engagement position but can engage with the engagement part of the goods by a considerable amount to complete the transfer. The hook control unit, upon detecting an overload of the hook drive device, controls the hook drive device to stop the hook; and The forward / backward drive device control unit controls the forward / backward drive device to move the hook forward or backward when the hook control unit stops the hook drive device and the obtained hook position is above the position threshold.

2. The transfer device according to claim 1, characterized in that, If the hook position obtained when the hook drive device stops is less than the aforementioned position threshold, the hook control unit controls the hook drive device to move the hook towards the retracted position. The aforementioned forward / backward drive device control unit controls the aforementioned forward / backward drive device so that after the aforementioned hook moves to the retracted position, the aforementioned hook moves forward or backward. The aforementioned drive control device includes an abnormality notification unit, which notifies an abnormality when the hook position obtained when the hook drive device is stopped is less than the aforementioned position threshold.

3. The transfer device according to claim 1 or 2, characterized in that, The aforementioned hook drive device outputs overload information based on a first load threshold. The hook control unit obtains load information related to the load from the hook drive device, detects overload based on a second load threshold that is lower than the first load threshold and the load information, and controls the hook drive device to stop the hook.

4. The transfer device according to claim 3, characterized in that, When the load information duration threshold exceeds the second load threshold, the hook control unit controls the hook drive device to stop the hook.

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