Transport device

Abstract

To provide a transport device capable of improving the work efficiency for transporting a transport object to a target position.SOLUTION: A transport device comprises: a transport part 90 transporting a transport object L; an electric motor 6 for lifting up and down a first arm 7 provided on the transport part 90; first and second operation levers 20, 30; a load cell 24 for operation levers for outputting an operation signal corresponding to a displacement amount of the operation levers; and a control part for controlling the electric motor 6 on the basis of the operation signal output from the load cell 24 for operation levers. The control part controls the electric motor 6 so as to reduce a rotation speed of the electric motor 6 to a second rotation speed slower than a first rotation speed, when the electric motor 6 is driven at the first rotation speed and when the transport object L is determined to arrive at a prescribed position separated from a target position.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a transport device including a transport section that transports an object to be transported, an electric motor for driving the transport section, and an operation section that operates the electric motor. [Background technology]

[0002] A conventional transport device of this type is a cargo handling machine described in Patent Document 1. This cargo handling machine includes a lifting mechanism 2 having an arm 1 for suspending a cargo at its tip, a rack 16 and a pinion gear 15 for raising and lowering the lifting mechanism 2, a worm reduction gear 14 connected to the pinion gear 15, a motor 12 connected to the worm reduction gear, a slip brake 13 engaged with the motor 12, a speed command device 3 provided at the tip of the arm 1, a swivel base 5 for rotating the lifting mechanism 2, a pole / base 7 to which the swivel base 5 is fixed, and casters 9 and a push bar 10 for moving the pole / base 7. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-362900 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a device that uses a motor to transport a cargo to a target position, such as the cargo transporter described above, if the motor is stopped when the cargo reaches the target position, the cargo will swing due to its inertia and it will take time for it to stop. Therefore, it is necessary to slow down the transport speed before the cargo reaches the target position and reduce the inertia of the cargo when transportation stops, thereby suppressing the swinging. Furthermore, in order to stop the cargo at a target position with high accuracy, it is necessary to reduce the rotational speed of the motor before the cargo reaches the target position, and to fine-tune the position of the cargo. However, in the conventional cargo transport machines described above, the operator manually operates a speed command device to control the rotational speed of the motor, and therefore the operator must visually determine whether the cargo is approaching the target position, and the timing of this determination is not consistent. Therefore, if the timing of the decision is too early, it will take a long time for the cargo to reach the target position, and if the timing is too late, there is a risk that the cargo will pass the target position, resulting in poor work efficiency. In particular, workers with little work experience take longer to learn the timing for slowing down the rotation speed of the motor than workers with much experience, which results in even poorer work efficiency.

[0005] Therefore, the present invention has been created to solve the above-mentioned problems, and has an object to provide a conveying device that can improve the work efficiency of transporting an object to a target position. [Means for solving the problem]

[0006] (First invention) In order to achieve the above object, a conveying device (1) according to a first aspect of the present invention comprises: A conveying section (90) for conveying an object to be conveyed (L: FIG. 1); an electric motor (6: FIG. 2) for driving the conveying unit (90); An operation unit (20, 30); an operation signal output unit (24: FIG. 3) that outputs an operation signal indicating that the operation unit (20, 30) has been operated; A control unit (70: FIG. 6) that controls an electric motor (6) based on an operation signal output from an operation signal output unit (24), The control unit (70) When the electric motor (6) is driven at a first rotation speed, if it is determined that the transport object (L) has reached a predetermined position away from the target position, the electric motor (6) is controlled so as to reduce the rotation speed of the electric motor (6) to a second rotation speed slower than the first rotation speed.

[0007] (Effects of the first invention) According to the first aspect of the present invention, when the control unit determines that the object to be transported has reached a predetermined position away from the target position while the electric motor is being driven at a first rotational speed, the control unit can control the electric motor to decelerate the rotational speed of the electric motor to a second rotational speed slower than the first rotational speed. Therefore, the electric motor can be controlled so as not to decelerate until the object to be transported reaches a specified position away from the target position, thereby improving the work efficiency of transporting the object to the target position. Furthermore, unlike conventional conveying devices in which an operator visually determines the timing to slow down the rotational speed of the electric motor, the timing to slow down the rotational speed of the electric motor can be made constant regardless of the operator's experience with the work, thereby improving the work efficiency of transporting the object to be transported to the target position. Furthermore, since control can be performed so that the stopping position does not become insufficient or excessive with respect to the target position, the conveying accuracy can be improved.

[0008] (Second Invention) In order to achieve the above-mentioned object, a conveying device (1) according to a second aspect of the present invention comprises: A conveying section (90) for conveying an object to be conveyed (L: FIG. 1); an electric motor (6: FIG. 2) for driving the conveying unit (90); An operation unit (20, 30); an operation signal output unit (24: FIG. 3) that outputs an operation signal corresponding to the amount of displacement of the operation unit (20, 30); A control unit (70: FIG. 6) that controls an electric motor (6) based on an operation signal output from an operation signal output unit (24), The control unit (70) The rotation speed of the electric motor (6) is controlled based on an operation signal output from an operation signal output section (24), and when it is determined that the object to be transported (L) has reached a predetermined position away from the target position, the responsiveness of the electric motor (6) to the amount of displacement of the operation section (20, 30) is reduced.

[0009] (Effects of the second invention) According to the second invention, the control unit controls the rotational speed of the electric motor based on the operation signal output from the operation signal output unit, and when it determines that the object to be transported has reached a predetermined position away from the target position, it can reduce the responsiveness of the electric motor to the displacement amount of the operation unit. Therefore, until the object to be transported reaches a specified position away from the target position, the electric motor's responsiveness to the displacement of the operating unit can be controlled so as not to decrease, thereby improving the work efficiency of transporting the object to the target position. Furthermore, the timing for reducing the responsiveness of the electric motor to the amount of displacement of the operating unit can be made constant regardless of the experience of the work, thereby improving the work efficiency of transporting the object to be transported to the target position. Furthermore, since control can be performed so that the stopping position does not fall short of or exceed the target position, the conveying accuracy can be improved.

[0010] (Third Invention) In order to achieve the above-mentioned object, a conveying device (1) according to a third aspect of the present invention is the conveying device (1) according to the above-mentioned first aspect of the present invention, The control unit (70) The electric motor (6) is controlled so that the rotation speed of the electric motor (6) gradually decreases when the transport object (L) reaches a predetermined position.

[0011] (Effects of the third invention) According to the third aspect of the present invention, the control unit can control the electric motor so that the rotation speed of the electric motor gradually decreases when the object to be transported reaches a predetermined position. Therefore, when the electric motor stops, the inertial force acting on the object to be transported can be reduced, thereby reducing the load on the electric motor and suppressing the shaking of the object to be transported.

[0012] (Fourth Invention) In order to achieve the above-mentioned object, a conveying device (1) according to a fourth aspect of the present invention is the conveying device (1) according to the above-mentioned second aspect of the present invention, The control unit (70) The electric motor (6) is controlled so that its responsiveness gradually decreases when the transport object (L) reaches a predetermined position.

[0013] (Effect of the fourth invention) According to the fourth aspect of the present invention, the control unit can control the electric motor so that the responsiveness gradually decreases when the object to be transported reaches a predetermined position. Therefore, when the electric motor stops, the inertial force acting on the object to be transported can be reduced, thereby reducing the load on the electric motor and suppressing the shaking of the object to be transported.

[0014] (Fifth Invention) In order to achieve the above-mentioned object, a conveying device (1) according to a fifth aspect of the present invention is the conveying device (1) according to the above-mentioned second aspect of the present invention, The device is characterized by including a setting section for setting the responsiveness in a changeable manner.

[0015] (Effect of the fifth aspect of the invention) According to the fifth aspect of the present invention, the setting unit is provided for variably setting the responsiveness of the electric motor to the amount of displacement of the operation unit, so that the work efficiency and the transport accuracy can be further improved. Also, by setting the responsiveness according to the skill of the worker, it is possible to prevent the decrease in work efficiency and transport accuracy caused by the skill.

[0016] (Sixth Invention) In order to achieve the above-mentioned object, a conveying device (1) according to a sixth aspect of the present invention is the conveying device (1) according to the first or second aspect of the present invention, A reducer (18: FIG. 2) is attached to the output shaft of the electric motor (6) to reduce the rotational speed of the electric motor (6). The conveying section (90) is a rotating part (19: FIG. 2) attached to an output shaft (19a: FIG. 4) of the reducer (18) and rotatable in the same direction as the rotation direction of the output shaft (19a); a first bearing (92: FIG. 2 ) that supports the rotating part (19) at a predetermined location (91) so that the rotating part (19) can rotate in a horizontal direction; a first arm (7) having a base end (7a) attached to a rotating portion (19) and a tip end (7b) movable up and down by rotation of the rotating portion (19); a second arm (11) having a base end (11a) attached to a tip end (7b) of the first arm (7); a second bearing (10) attached between a tip (7b) of the first arm (7) and a base end (11a) of the second arm (11) so that the second arm (11) can rotate horizontally around its base end (11a); a third arm (15) whose upper end (15a) is attached to the tip (11b) of the second arm (11) and hangs down from the tip (11b); a third bearing (14) attached between a tip end (11b) of the second arm (11) and an upper end (15a) of the third arm (15) so that the third arm (15) is rotatable in a horizontal direction about its own upper end (15a); a holding portion (17) attached to the third arm (15) for holding an object to be transported (L); The operating parts (20, 30) are characterized in that they are attached to the third arm (15).

[0017] (Effect of the sixth aspect of the invention) According to the sixth invention, when the electric motor rotates, the rotating part rotates via a reducer, the tip of the first arm whose base end is attached to the rotating part rises and falls, and the object to be transported held in the holding part of the third arm rises and falls. Therefore, by controlling the rotation speed of the electric motor, the lifting position of the transport object can be controlled with high precision. Moreover, since the rotating part is supported at a predetermined location by the first bearing and can rotate horizontally, the entire conveying part having the rotating part, the first arm, the second arm and the third arm can be rotated horizontally, thereby expanding the range in which the objects to be conveyed are conveyed. Furthermore, since the holding unit that holds the object to be transported is attached to the third arm and the operating unit is attached to the third arm, the operator operating the operating unit can accurately recognize the position of the object to be transported held in the holding unit, thereby improving the transport accuracy.

[0018] (Seventh Invention) In order to achieve the above-mentioned object, a conveying device (1) according to a seventh aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, The reducer (18) is This is characterized by a structure in which the input shaft from the electric motor (6) and the output shaft after reduction are aligned in the same straight line.

[0019] (Effects of the seventh aspect of the invention) According to the seventh invention, the reducer is structured so that the input shaft from the electric motor and the output shaft after reduction are collinear, thereby enabling the height of the reducer to be reduced, and therefore the height of the entire conveying section to be reduced. Therefore, the transport device can be easily installed even in a location where there are height restrictions.

[0020] (8th invention) In order to achieve the above-mentioned object, a conveying device (1) according to an eighth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, The control unit (70) The device is characterized by having a rotation angle detection unit that outputs a signal corresponding to the rotation angle of the rotating part (19), detecting the rotation angle of the rotating part (19) based on the signal output from the rotation angle detection unit, and controlling the rotation speed of the electric motor (6) according to the detected rotation angle.

[0021] (Effect of the eighth aspect of the invention) According to the eighth aspect of the present invention, the control unit can control the rotation speed of the electric motor based on the rotation angle of the rotating part journaled by the first bearing. The rotation angle of the rotating part is the rotation angle of the entire transport device, and the horizontal transportable range of the transported object is determined by the rotation angle. Also, the lift position of the tip of the first arm, i.e., the vertical transportable range of the transported object, is determined by the rotation speed of the electric motor. Therefore, according to the eighth invention, even if the transportable range of the transport object changes depending on the environment in which the transport device is installed or the type of transport object, the transportable range can be adapted to the change by controlling the rotation speed of the electric motor based on the rotation angle of the rotating part, so there is no risk of the transport object colliding with an obstacle or the like while being raised or lowered.

[0022] (9th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a ninth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, a sensor (50) provided between the lower end (15b) of the third arm (15) and the holding portion (17) and configured to output a signal corresponding to the weight of the object (L) held by the holding portion (17); an alarm unit (93) that notifies a user when the control unit (70) determines, based on a signal output from the sensor (50), that the weight applied to the holding unit (17) exceeds a predetermined weight; and The present invention is characterized in that it is provided with:

[0023] (Effect of the ninth aspect of the invention) According to the ninth aspect of the present invention, when the weight applied to the holding portion exceeds a predetermined weight, this fact can be notified, thereby increasing the safety of the work and preventing breakdowns in the conveying device.

[0024] (10th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a tenth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, A first electromagnetic brake (3: FIG. 1) is attached to the first bearing (92) to control the horizontal rotation of the rotating part (19). A second electromagnetic brake (12: FIG. 2) is attached to the second bearing (10) to control the horizontal rotation of the second arm (11) about its base end (11a), A third electromagnetic brake (13) is attached to the third bearing (14) to control the horizontal rotation of the third arm (15) about its upper end (15a), The operation unit (20) has: The brake switch (23) is provided for simultaneously activating the first electromagnetic brake (3), the second electromagnetic brake (12) and the third electromagnetic brake (13).

[0025] (Effect of the 10th Invention) According to the tenth aspect of the present invention, the first bearing is provided with a first electromagnetic brake that controls the horizontal rotation of the rotating part, so that the horizontal rotation of the entire conveying device can be controlled and stopped by operating a brake switch. The second bearing is provided with a second electromagnetic brake that controls the horizontal rotation of the second arm around its base end, so that the horizontal rotation of the second arm can be controlled and stopped by operating a brake switch. The third bearing is provided with a third electromagnetic brake that controls the horizontal rotation of the third arm around its top end, so that the horizontal rotation of the third arm can be controlled and stopped by operating a brake switch. Furthermore, by operating the brake switch, the first electromagnetic brake, the second electromagnetic brake and the third electromagnetic brake can be activated simultaneously, so that when each electromagnetic brake is activated, there is no risk of the conveying section rotating, or the first arm or the second arm rotating, or the third arm rotating due to the inertia of the conveyed object, which would result in a deviation in the stopping distance of the conveyed object.

[0026] (11th invention) In order to achieve the above-mentioned object, a conveying device (1) according to an eleventh aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, The control unit (70) The device is characterized by being equipped with a rotation angle detection unit that outputs a signal corresponding to the rotation angle of the rotating part (19), calculating the position of the object to be transported (L) based on the signal output from the rotation angle detection unit and the rotation speed of the electric motor (6), and determining whether the object to be transported (L) has reached a predetermined position based on the calculated position.

[0027] (Effects of the eleventh aspect of the invention) According to the eleventh aspect of the present invention, the position of the object to be transported is calculated based on the rotation angle of the rotating part and the rotation speed of the electric motor, and it is possible to determine whether the object to be transported has reached a predetermined position based on the calculated position. Therefore, when the control unit determines that the transport object has reached a predetermined position, the control unit can control the electric motor to reduce the rotation speed of the electric motor to a second rotation speed slower than the first rotation speed. Also, the control unit can control the electric motor to reduce the responsiveness of the rotation speed to the displacement of the operation unit. Therefore, according to the eleventh aspect of the present invention, the efficiency of the work of transporting the object to the target position can be improved.

[0028] (12th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a twelfth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, The number of rotations of the electric motor (6) and the rotation angle of the rotating part (19) correspond to each other, A limit switch (60) is provided which is activated when the rotation angle of the rotating part (19) reaches a predetermined angle and stops the electric motor (6). The limit switch (60) is The device is characterized in that it operates when the rotation angle of the rotating part (19) reaches a predetermined rotation angle, even if the rotation speed of the electric motor (6) reaches a preset upper limit rotation speed but this is not detected by the control part (70).

[0029] (Effects of the twelfth aspect of the invention) According to the twelfth aspect of the present invention, even if the rotation speed of the electric motor reaches a preset upper limit rotation speed but this is not detected by the control unit, the limit switch is activated when the rotation angle of the rotating part reaches a predetermined rotation angle, and the electric motor can be stopped. Therefore, even if the object being transported rises or falls to an unexpected position during transportation and the control unit is unable to detect this, the limit switch can be activated to stop the electric motor. In other words, the object to be transported can be prevented from passing through the target position and colliding with an obstacle, the ground, or a person, thereby increasing the safety of the work and preventing the object to be transported from being damaged.

[0030] (13th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a thirteenth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, The operation unit (20, 30) is an operating lever shaped to be held in the palm of an operator who uses the conveying device (1) to convey an object to be conveyed (L), A feature of this device is that the conveying section (90) can be moved horizontally by an operator applying a horizontal force to the operating levers (20, 30) held in the palm of his / her hand.

[0031] (Effects of the thirteenth aspect of the invention) According to the thirteenth aspect of the present invention, the operator can move the conveying section horizontally by moving the operating lever held in the palm of his / her hand horizontally, thereby enabling the operator to easily convey the object to be conveyed in the direction intended. Moreover, since the operating lever is attached to the third arm to which the holding portion for holding the transport object is attached, the operator can accurately visually check the current position of the transport object.

[0032] (14th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a fourteenth aspect of the present invention is the conveying device (1) according to the thirteenth aspect of the present invention, The operating levers (20, 30) are The device is provided with a first operating lever (20) and a second operating lever (30) which are parallel to each other, At least one of the first operating lever (20) and the second operating lever (30) is provided with a switch (21) that is operated to put the electric motor (6) into a drivable state; The operation signal output unit (24) The device is characterized by outputting an operation signal corresponding to the amount of displacement of at least one of the first operating lever (20) and the second operating lever (30).

[0033] (Effects of the fourteenth aspect of the invention) According to the fourteenth invention, since the device is provided with a first operating lever and a second operating lever that are parallel to each other, an operator can transport the object to be transported while holding the first operating lever with one palm and the second operating lever with the other palm. Therefore, the worker can receive with both arms the inertial force that occurs when the transport object moves, and can transport the transport object in a stable state. Furthermore, since the transport work can be performed using both arms, the accumulation of fatigue due to the transport work can be prevented from being concentrated in one arm.

[0034] (15th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a fifteenth aspect of the present invention is the conveying device (1) according to the tenth aspect of the present invention, the first bearing (92), the second bearing (10), and the third bearing (14) each have a hollow center, and the first electromagnetic brake (3), the second electromagnetic brake (12), and the third electromagnetic brake (13) each have a hollow center, The wiring electrically connecting the operation unit (20, 30), the operation signal output unit (24), and each of the electromagnetic brakes (3, 12, 13) to the control unit (70) passes through each of the bearings (92, 10, 14) and each of the electromagnetic brakes (3, 12, 13) hollow portions.

[0035] (Effects of the fifteenth aspect of the invention) According to the fifteenth aspect of the present invention, the wiring electrically connecting the operating unit, the operating signal output unit, and each electromagnetic brake to the control unit passes through each bearing and each hollow portion of each electromagnetic brake. Therefore, even when the rotating unit, the first arm, the second arm, and the third arm are moved, there is no risk of the wiring getting caught on them. As a result, there is no risk of the operating range of the rotating unit and each arm being restricted, and work safety can be improved.

[0036] (16th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a sixteenth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, A pair of rails (2,2) parallel to each other; a moving member (91: FIG. 2) provided on the rail (2, 2) so as to be movable along the rail (2, 2), The first bearing (92) is attached to the moving member (91), The moving member (91) has: Rollers (5: FIG. 5) for moving the moving member (91) along the rails (2, 2) are provided at locations corresponding to the rails (2, 2), Rail (2,2) has A track portion (2a: FIG. 5) for allowing the roller (5) to roll along the rail (2, 2) is formed along each of the rails (2, 2), Laura (5) The grooves are characterized in that they are provided so as to sandwich the upper surface (2b) and the lower surface (2c) of the raceway portion (2a).

[0037] (Effects of the 16th Invention) According to the sixteenth invention, the first bearing for horizontally rotating the rotating part that raises and lowers the first arm is attached to a movable member that can move along a rail, so that the conveying device can be moved along the rail, thereby expanding the conveying range of the objects to be conveyed. Furthermore, each roller on the moving member is arranged in a manner that clamps the upper and lower surfaces of the track portion of the rail, so that even when the conveying device moves along the rail and stops, there is no risk of the rollers rolling on the upper surface of the track portion floating up from the track portion due to the inertia of the conveying device. Therefore, the conveying device can be stopped in a stable posture, so that the object to be conveyed can be stopped at the target position with high accuracy.

[0038] (17th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a seventeenth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, The second arm (11) is characterized in that it can rotate horizontally at least 360 degrees around the second bearing (10).

[0039] (Effects of the 17th Invention) According to the seventeenth aspect of the present invention, the second arm can rotate horizontally at least 360 degrees around the second bearing, thereby making it possible to expand the transport range of the objects to be transported and to improve work efficiency.

[0040] (18th invention) In order to achieve the above-mentioned object, a conveying device (1) according to an eighteenth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, The third arm (15) is characterized in that it is rotatable horizontally at least 360 degrees around the third bearing (14).

[0041] (Effects of the 18th Invention) According to the eighteenth aspect of the present invention, the third arm can rotate at least 360 degrees horizontally around the third bearing, so that the transport range of the transport object can be expanded and the work efficiency can be improved. In particular, by rotating the third arm, the orientation of the transport object held by the holding part of the third arm can be changed, so that the transport object can be stopped at the target position with the same orientation. Furthermore, since the operating unit attached to the third arm also rotates together with the third arm, the operator can maintain the operating unit in a state that is easy to operate even if the rotation angle of the second arm changes. Therefore, there is no risk of it becoming difficult to operate the operating unit during the transport of the transport object, and work efficiency can be improved.

[0042] (19th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a nineteenth aspect of the present invention is the conveying device (1) according to the sixth aspect of the present invention, The conveying device (1) is characterized in that, when the first arm (7) is vertically projected onto a horizontal plane on which the second arm (11) is present, the angle (α, β: Figure 9) formed between the projected image (7a: Figure 9) of the first arm (7) and the second arm (11) is within a range not exceeding 180 degrees.

[0043] (Effects of the 19th Invention) The state in which the projected image of the first arm projected onto the horizontal plane on which the second arm is located and the second arm are in a straight line is the state in which the turning radius of the first arm and the second arm is at its maximum. Therefore, if the object to be transported is transported within a range that does not result in this state, the object can be transported over the shortest distance, thereby improving work efficiency. Therefore, according to the 19th invention, the conveying device is used in a range in which, when the first arm is projected vertically onto the horizontal plane on which the second arm exists, the angle formed by the projected image of the first arm and the second arm does not exceed 180 degrees, that is, in a range in which the projected image of the first arm and the second arm do not form a straight line, thereby improving work efficiency.

[0044] (20th invention) In order to achieve the above-mentioned object, a conveying device (1) according to a twentieth aspect of the present invention is the conveying device (1) according to the above-mentioned nineteenth aspect of the present invention, The conveying device (1) is arranged along a product assembly line (100: FIG. 9), The object (L) to be conveyed is characterized by being something to be attached to a product flowing through an assembly line (100).

[0045] (Effect of the 20th Invention) According to the 20th aspect of the present invention, when the transported object reaches a predetermined distance from the attachment position for the product, the transport speed can be automatically slowed down or the responsiveness of the electric motor can be reduced, thereby improving the work efficiency of attaching the transported object to products flowing on the assembly line. Furthermore, since the stopping position of the transported object relative to the product can be controlled so as not to be too close or too close, the mounting accuracy can be improved. Effect of the Invention

[0046] According to the present invention, it is possible to provide a transport device that can improve the efficiency of transporting an object to a target position. [Brief description of the drawings]

[0047] [Figure 1] 1 is a perspective view of a conveying device according to an embodiment of the present invention, viewed from diagonally above the front right. [Diagram 2] 1 is a perspective view of a transport device according to an embodiment of the present invention, seen from diagonally below and behind to the right; [Diagram 3] 2 is an explanatory diagram showing a part of a lower portion of the conveying device shown in FIG. 1 as viewed from the front. [Figure 4] 2 is an explanatory diagram showing an enlarged view of an electric motor, a reducer, and a limit switch provided in the conveying device shown in FIG. 1. [Diagram 5] 2 is an explanatory diagram showing a mounting structure of rollers and rails provided in the conveying device shown in FIG. 1. [Figure 6] 2 is an explanatory block diagram showing a main electrical configuration of the transport device shown in FIG. 1. [Figure 7] 7 is a flowchart showing the flow of main processes executed by a CPU of the control unit shown in FIG. 6. [Figure 8] 8 is a flowchart showing a continuation of the process shown in FIG. 7. [Figure 9] 2 is an explanatory diagram showing a conveying range and an example of use of the conveying device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] A transport device according to an embodiment of the present invention will be described with reference to the drawings. [Main components] As shown in FIG. 1 and FIG. 2, the conveying device 1 of this embodiment includes a conveying section 90 for conveying an object L to be conveyed, and a pair of rails 2, 2 parallel to each other for moving the conveying section 90 back and forth. The conveying section 90 includes a moving member 91 for moving the conveying section 90 along the rails 2, 2, a first arm 7 that can be raised and lowered up and down, a second arm 11 that can be turned horizontally, and a third arm 15 that can be rotated horizontally. The conveying section 90 also includes an electric motor 6 (FIG. 2) for raising and lowering the first arm up and down, a reducer 18 for reducing the rotation speed of the electric motor 6, a rotating section 19 that rotates with the rotation of the reducer 18, and a first operating lever 0 and a second operating lever 30 for operating the electric motor 6. In the following description, when the contents common to the first operating lever 0 and the second operating lever 30 are described, they may be simply referred to as operating levers. Moreover, when describing content common to the first arm 7, the second arm 11 and the third arm, they may be simply referred to as arms.

[0049] The rails 2, 2 are arranged on a horizontal plane parallel to the floor or ground on which the conveying device 1 is installed. At the right and left ends of the moving member 91 that supports the conveying section 90 downward, rollers 5 for supporting the moving member 91 itself on the rails 2, 2 and moving along the rails 2, 2 are rotatably supported. In this embodiment, four rollers 5 are rotatably supported at each of the right and left ends of the moving member 91. As shown in FIG. 5, on the inside of each rail 2, a track portion 2a for each roller 5 to roll along the rail 2 is formed along the rail 2, and each roller 5 is provided in a form sandwiching an upper surface 2b and a lower surface 2c of the track portion 2a. Therefore, even if the conveying section 90 stops after moving along the rail 2, there is no risk that the rollers 5 rolling on the upper surface of the track section 2a will float up from the track section 2a due to the inertia of the conveying section 90, so the conveying device 1 can be stopped in a stable posture, and the object L to be conveyed can be stopped accurately at the target position.

[0050] A connection member 94 (FIG. 4) for rotatably supporting the rotating part 19 is attached to the lower surface of the moving member 91, and the rotating part 19 is rotatably supported by the connection member 94. As shown in FIG. 4, the reducer 18 is attached to the output shaft of the electric motor 6, and the rotating part 19 is rotatably supported by the output shaft of the reducer 18. The rotating part 19 rotates in the same direction as the rotation direction of the output shaft of the reducer 18. The reducer 18 has a structure in which the input shaft from the electric motor 6 and the output shaft after reduction are aligned in the same line. For example, the reducer 18 is a reducer for a robot joint used in the joint of a multi-axis robot. For this reason, the height of the reducer 18 itself can be lower than that of a conveying device using a reducer such as a reducer using a ball screw mechanism, a worm reducer, or a parallel shaft reducer as in the conventional case. Therefore, the overall height of the transport section 90 can be reduced, so that the transport device 1 can be easily installed even in a place where the installation location has height restrictions. In this embodiment, the electric motor 6 is a brushless AC servo motor with a brake, and is equipped with an encoder capable of detecting its own rotation angle and rotation speed.

[0051] As shown in FIG. 2, the connection member 94 that rotatably supports the rotating part 19 is axially supported by the moving member 91 via the first bearing 92. This allows the conveying part 90 to rotate horizontally by 360 degrees or more together with the rotating part 19. A first electromagnetic brake 3 (FIG. 1) is attached on the first bearing 92 to brake the first bearing 92 and stop the rotation of the rotating part 19. The base end 7a of the first arm 7 is fixed to the rotating part 19, and the tip 7b of the first arm 7 is configured to rise and fall when the rotating part 19 rotates. The connection member 9 is attached to the tip 7b of the first arm 7 to connect the tip 7b to the base end 11a of the second arm 11. Both ends of the tip 7b of the first arm 7 are rotatably supported by the connection member 9 via the pivot members 9a.

[0052] Additionally, the tip of auxiliary arm 8 is rotatably supported by pivot member 9b on connecting member 9, and the base end of auxiliary arm 8 is rotatably supported by connecting member 94 which pivotally supports rotating portion 19 (FIG. 4). In other words, first arm 7 and auxiliary arm 8 form a parallel link mechanism, which maintains the elevated position of first arm 7. As described above, the first bearing 92 for horizontally rotating the rotating part 19 that raises and lowers the first arm 7 is attached to the movable member 91 that can move along the rails 2, 2, so that the conveying device 1 can be moved along the rails 2, 2, thereby expanding the conveying range of the object L to be conveyed.

[0053] A base end 11a of a second arm 11 is journaled to the connecting member 9 via a second bearing 10. This allows the second arm 11 to rotate 360 ​​degrees or more in the horizontal direction around the base end 11a. This makes it possible to expand the transport range of the transport object and improve the work efficiency. A second electromagnetic brake 12 for stopping the rotation of the second arm 11 is attached to the lower part of the base end 11a of the second arm 11. The upper end 15a of the third arm 15 is supported by a third bearing 14 on the tip 11b of the second arm 11. The third arm 15 is supported by the tip 11b of the second arm 11 in a state of hanging down from the tip 11b of the second arm 11, and is rotatable horizontally 360 degrees or more around its own upper end 15a. This makes it possible to expand the transport range of the object L to be transported and to improve the work efficiency. In particular, by rotating the third arm 15, the orientation of the object L held by the holding portion 17 of the third arm 15 can be changed, so that the object L can be stopped at the target position in the same orientation.

[0054] A third electromagnetic brake 13 for stopping the rotation of third arm 15 is attached to a tip 11b of second arm 11. Hereinafter, when describing content common to first electromagnetic brake 3, second electromagnetic brake 12, and third electromagnetic brake 13, they may be simply referred to as the electromagnetic brakes. As described above, when the electric motor 6 rotates, the rotating part 19 rotates via the reduction gear 18, the tip 7b of the first arm 7, whose base end 7a is attached to the rotating part 19, rises and falls, and the transported object L held by the holding part 17 at the lower end 15b of the third arm 15 rises and falls. Therefore, by controlling the rotation speed of the electric motor 6, the lifting position of the transport object L can be controlled with high precision. Moreover, since the rotating part 19 is journalled to the moving member 91 by the first bearing 92 and is rotatable horizontally, the entire transport part 90 having the rotating part 19, the first arm 7, the second arm 11 and the third arm 15 can be rotated horizontally, thereby expanding the range in which the transport object L can be transported. In this embodiment, the first bearing 92, the second bearing 10 and the third bearing 14 are each a cross roller bearing and are hollow in the centre.

[0055] A first operating lever 20, a second operating lever 30, and a holding portion 17 for holding the transport object L are attached to the third arm 15. Therefore, an operator who operates the operating levers 20, 30 can accurately recognize the position of the transport object L held by the holding portion 17, thereby improving the transport accuracy. In particular, by rotating the third arm 15, the orientation of the transport object L held by the holding portion 17 of the third arm 15 can be changed, so that the transport object L can be stopped at the target position in the same orientation. Furthermore, since the operating levers 20, 30 attached to the third arm 15 also rotate together with the third arm 15, the operator can maintain the operating levers 20, 30 in a state that makes them easy to operate even if the rotation angle of the second arm 11 changes. Therefore, there is no risk of it becoming difficult to operate the operating levers 20, 30 during the transportation of the object L to be transported, and the work efficiency can be improved.

[0056] As shown in FIG. 3, the operation lever load cell 24 is attached to the lower end 15b of the third arm 15 by a mounting member 42, and a transmission member 43 for transmitting the displacement of the first operation lever 20 and the second operation lever 30 is attached on the operation lever load cell 24. The transmission member 43 is a member extending in the horizontal direction, and the first operation lever 20 is attached to one end thereof by a mounting member 41, and the second operation lever 30 is attached to the other end thereof. A load receiving member 44 is disposed on the upper surface of the operation lever load cell 24, and the central portion of the transmission member 43 is attached to the upper surface of the load receiving member 44. When one or both of the first operation lever 20 and the second operation lever 30 are pressed downward, the transmission member 43 is displaced downward and the load receiving member 44 is displaced downward, and an operation signal corresponding to the amount of displacement is output from the operation lever load cell 24 to the control unit 70 (FIG. 6). The operating lever load cell 24 is an example of an operating signal output section of the present invention.

[0057] A push button 21 that can be pressed is provided at the top of the first operating lever 20. A drive switch 22 (FIG. 6) that performs a switching operation when the push button 21 is pressed is provided inside the first operating lever 20. The drive switch 22 is a switch for putting the electric motor 6 into a driveable state, and when the push button 21 is pressed, the drive switch 22 is turned on, the electric motor 6 is put into a driveable state, the electromagnetic brakes are released, and the rotating part 19 and each arm are made rotatable. When the push button 21 is released from the pressed state, the drive switch 22 is turned off, the electric motor 6 is put into a non-driveable state, the electromagnetic brakes are activated, and the rotating part 19 and each arm are made non-rotatable. The drive switch 22 having the function of activating each electromagnetic brake is an example of a brake switch of the present invention.

[0058] The first operating lever 20 and the second operating lever 30 are linked by a transmission member 43, and when either one of the operating levers is operated, the displacement amount of that operating lever is transmitted to the operating lever load cell 24 via the transmission member 43. Even when both operating levers are operated simultaneously, the transmission member 43 is displaced and the displacement amount is transmitted to the operating lever load cell 24 in the same way as when one operating lever is operated. In other words, the worker can transport the transport object L while holding one operating lever with one palm and the other operating lever with the other palm. Therefore, the worker can use both arms to receive the inertial force generated when the transport object L moves, and can transport the transport object L in a stable state. Moreover, since the transport work can be performed using both arms, the accumulation of fatigue due to the transport work can be prevented from being concentrated in one arm.

[0059] The first operating lever 20 and the second operating lever 30 are each formed in a shape and size that allows an operator to grip and operate them with the palm of his / her hand. A force applied horizontally to at least one of the first operating lever 20 and the second operating lever 30 gripped by the operator in the palm of his / her hand is transmitted to the third arm 15, causing the third arm 15 to rotate, or the second arm 11 to swing horizontally, or the conveying unit 90 to swing horizontally. In other words, the operator can easily convey the object L to be conveyed in the intended direction by moving the operating lever in the direction in which the object L is to be conveyed. The first operating lever 20 and the second operating lever 30 are an example of an operating unit of the present invention.

[0060] A hook-shaped holder 17 is attached to the lower end of the third arm 15 via a load cell 50 for a suspended load. The operating levers 20, 30 are attached to the third arm to which the holder 17 for holding the transport object L is attached, so that the operator can accurately see the current position of the transport object L. When the transport object L is hung from the holder 17, a signal corresponding to the weight of the transport object L is output from the load cell 50 for a suspended load to the control unit 70 (Fig. 6). When the weight of the transport object L exceeds a maximum load preset in the control unit 70, the alarm sound output unit 93 (Fig. 7) is activated and a predetermined alarm sound is output. Therefore, the worker can know that the weight of the object L to be conveyed has exceeded the maximum load, so that the safety of the work can be improved and the breakdown of the conveying device 1 can be prevented. The suspended load cell 50 is an example of a sensor of the present invention, and the alarm sound output unit 93 is an example of an alarm unit of the present invention.

[0061] In the third arm 15, a mounting member 16 is fixed near the operating levers 20, 30, that is, at a position where an operator can immediately operate the levers. The mounting member 16 is provided with an operation preparation switch 31, an abnormality reset switch 32, and an emergency stop switch 33. The operation preparation switch 31 is a push-type switch for supplying power to the conveying device 1 and making it ready for conveying. When the operation preparation switch 31 is pressed, a translucent operation preparation notification lamp 31a provided therein lights up, notifying that the conveying device 1 is ready for operation. The emergency stop switch 33 is an alternate switch for stopping the conveying device 1 in an emergency during conveying, etc. The abnormality reset switch 32 is a push-type switch for resetting the abnormal state when an abnormality occurs in the conveying device 1 and the conveying device 1 stops, and the cause of the abnormality is removed. When an abnormality occurs in the conveying device 1, the abnormality reset switch 32 has a translucent abnormality notification lamp 32a that is turned on to notify the occurrence of the abnormality, and when the abnormality reset switch 32 is pressed, the abnormality notification lamp 32a is turned off to notify the fact that the abnormality has been resolved. In the following explanation, when explaining the content common to the drive switch 22, the stop switch 23, the operation preparation switch 31, the abnormality reset switch 32, and the emergency stop switch 33, they may be simply referred to as switches.

[0062] The first bearing 92, the second bearing 10 and the third bearing 14 each have a hollow center, and the first electromagnetic brake 3, the second electromagnetic brake 12 and the third electromagnetic brake 13 each have a hollow center. Wiring electrically connecting the operation lever load cell 24, the load load cell 50, the switches and the electromagnetic brakes 3, 12 and 13 to the control unit 70 passes through the hollow portions of the bearings 92, 10 and 14 and the electromagnetic brakes 3, 12 and 13, and through tubes 51 provided along the arms. Therefore, there is no risk of the wiring getting caught on the rotating portion 19 and the arms 7, 11, 15 during the transport operation, which in turn limits the transport range, thereby improving the safety of the operation.

[0063] The electric motor 6 outputs an encoder value corresponding to its own rotation angle, and the control unit 70 recognizes the rotation angle of the electric motor 6, that is, the rotation angle of the rotating unit 19, by calculating the encoder value, and controls the lifting angle of the first arm 7. In addition, in order to prevent the conveyed object L from contacting an obstacle or a floor, an upper limit and a lower limit are set for the first arm 7, and the control unit 70 controls the electric motor 6 within a range in which the first arm 7 does not reach the upper limit and the lower limit. Then, when the encoder value acquired from the electric motor 6 becomes a first value set in advance, the control unit 70 determines that the first arm 7 has approached the upper limit, and stops the electric motor 6. In addition, when the encoder value acquired from the electric motor 6 becomes a second value set in advance, the control unit 70 determines that the first arm 7 has approached the lower limit, and stops the electric motor 6. However, in order to enhance the safety of the work, it is desirable to configure the electric motor 6 so that it can be controlled to stop even if the control unit 70 is unable to calculate the rotation angle of the electric motor 6 for some reason. Therefore, in the conveying device 1 of this embodiment, as shown in FIG. 4, a limit switch 60 for stopping the electric motor 6 in an emergency is rotatably attached to the output shaft 19a of the rotating part 19.

[0064] The limit switch 63 operates when the control unit 70 fails to detect, for some reason, that the first arm 7 has approached its upward limit, and mechanically stops the electric motor 6. The limit switch 64 operates when the control unit 70 fails to detect, for some reason, that the first arm 7 has approached its downward limit, and mechanically stops the electric motor 6. Furthermore, when the first arm 7 is rising and the electric motor 6 overruns beyond the operation timing of the limit switch 63 due to some cause, such as runaway of the control unit 70, the limit switch 61 operates to cut off the power supplied to the electric motor 6. Furthermore, when the first arm 7 is lowering and the electric motor 6 overruns beyond the operation timing of the limit switch 64 due to some cause, such as runaway of the control unit 70, the limit switch 62 operates to cut off the power supplied to the electric motor 6. In other words, the object L to be transported can be prevented from passing through the target position and colliding with an obstacle, the ground, or a person, thereby improving the safety of the work and preventing damage to the object L to be transported.

[0065] [Main electrical configuration] As shown in FIG. 6, the control unit 70 of the transport device 1 includes an input unit 71, a storage unit 72, a CPU 73, and a power supply unit 74. The control unit 70 can be provided at a predetermined location of the transport device 1, for example, at a connection member 94 (FIG. 4), or at a location other than the installation location of the transport device 1, for example, at a control room that controls the transport device 1. The input unit 71 is electrically connected to the drive switch 22 and the stop switch 23 provided on the first operation lever 20, the operation lever load cell 24, the emergency stop switch 33, the operation preparation switch 31, the abnormality reset switch 32, the operation panel 80, and the load load cell 50. The output unit 75 is electrically connected to the electric motor drive circuit 6a for driving the electric motor 6, the operation preparation notification lamp 31a, the abnormality notification lamp 32a, the first electromagnetic brake 3, the second electromagnetic brake 12, the third electromagnetic brake 13, and the notification sound output unit 93. The electric motor drive circuit 6a is electrically connected to a limit switch 60. The operation panel 80 is an example of a setting unit of the present invention.

[0066] The CPU 73 executes a computer program stored in the storage unit 72 to calculate the number of rotations and the rotation speed of the electric motor 6, and controls the rotation speed of the electric motor 6, as well as driving and stopping the electric motor 6. The operation panel 80 is used when inputting conditions such as limitations on the number of rotations (rotation angle) of the electric motor 6, the timing to decelerate the electric motor 6, and the timing to reduce the responsiveness of the electric motor 6, and storing these in the storage unit 72. If the encoder value obtained from the electric motor 6 and the lifting range of the transport object L are associated with each other and stored in the storage unit 72, the data input to the operation panel 80 may be the encoder value obtained from the electric motor 6 or the actual lifting range (lifting height and lowering height) of the transport object L. Then, when the CPU 73 determines that the encoder value acquired from the electric motor 6 has reached the encoder value stored in the memory unit 72, the CPU 73 decelerates the electric motor 6 or reduces the responsiveness of the electric motor 6.

[0067] The conveying device 1 is characterized in that the rotation speed of the electric motor 6 is automatically and gradually decelerated when the object L to be conveyed reaches a predetermined distance from the target height. Therefore, the electric motor 6 can be controlled not to decelerate until the object L to be transported reaches a predetermined distance from the target height, thereby improving the work efficiency of transporting the object L to the target position. Furthermore, unlike conventional conveying devices in which the worker visually determines the timing to slow down the rotational speed of the electric motor 6, the timing to slow down the rotational speed of the electric motor 6 can be made constant regardless of the worker's experience with the work, thereby improving the work efficiency of transporting the object L to be transported to the target position. Furthermore, since control can be performed so that the stopping position does not fall short of or exceed the target position, the conveying accuracy can be improved.

[0068] Furthermore, the control unit 70 can control the electric motor 6 so that the rotation speed of the electric motor 6 automatically and gradually decreases when the transport object L reaches a predetermined distance from the target height. Therefore, when the electric motor 6 stops, the inertial force acting on the object L to be conveyed can be reduced, so that the load applied to the electric motor 6 can be reduced, and the shaking of the object L to be conveyed can be suppressed.

[0069] In addition, when it is determined that the object L to be conveyed has reached a predetermined distance from the target height, the control unit 70 can be configured to gradually reduce the responsiveness of the electric motor 6 with respect to the displacement amounts of the operation levers 20 and 30. That is, it can also be configured to reduce the sensitivity of the electric motor 6 with respect to the operation of the operation levers 20 and 30. For example, when the rotational speed of the electric motor 6 with respect to the displacement length d1 of the operation levers 20 and 30 is v1, the rotational speed of the electric motor 6 with respect to the displacement length d1 of the operation levers 20 and 30 is changed to v2 (<v1). Data for determining such responsiveness can be stored in the storage unit 72, and the responsiveness can be changed by operating the operation panel 80.

[0070] In this way, until the object L to be conveyed reaches a predetermined distance from the target height, it is possible to control so as not to reduce the responsiveness of the electric motor 6 with respect to the displacement amounts of the operation levers 20 and 30, so that the working efficiency of conveying the object L to the target position can be improved. Moreover, since the timing at which the responsiveness of the electric motor 6 with respect to the displacement amounts of the operation levers 20 and 30 is reduced can be made constant regardless of the empirical value of the work, the working efficiency of conveying the object L to the target position can be improved. Furthermore, since it is possible to control so that the stop position with respect to the target position does not fall short or exceed, the conveyance accuracy can also be improved.

[0071] In addition, the control unit 70 can control the electric motor 6 so that the responsiveness gradually decreases when the object L to be conveyed reaches a predetermined position. Therefore, when the electric motor 6 stops, the inertial force acting on the object L to be conveyed can be reduced, so that the load applied to the electric motor 6 can be reduced, and the shaking of the object L to be conveyed can be suppressed. Furthermore, the operation panel 80 allows the responsiveness of the electric motor 6 to be changed, which further improves work efficiency and transport accuracy. Also, by setting the responsiveness according to the skill of the worker, it is possible to prevent a decrease in work efficiency and transport accuracy due to skill.

[0072] The memory unit 72 also stores a smoothing program for smoothing the speed command value and the torque command value output from the control unit 70 to the electric motor drive circuit 6a. Therefore, there is no risk of the accuracy of the motor control being reduced due to the vibrations generated when the transport object L is transported being transmitted to the operation levers 20, 30, which would reduce the accuracy of the data acquired from the operation lever load cell 24. Note that a smoothing circuit may be used instead of the smoothing program.

[0073] [Processing performed by CPU73] Next, the flow of the processing executed by the CPU 73 will be described with reference to Figures 7 and 8. Note that steps of the processing executed by the CPU 73 are abbreviated as S. The CPU 73 judges whether or not the drive switch 22 (FIG. 6) is ON when the operator presses the push button 21 provided on the first operating lever 20 (S10 in FIG. 7), and if it judges that the drive switch 22 is ON (S1: Yes), it turns off the electromagnetic brakes 3, 12, 14. This allows the transport unit 90 and the second arm 11 to each swing horizontally, and allows the third arm 15 to rotate.

[0074] Subsequently, the CPU 73 determines whether the operation levers 20 and 30 have been operated (S3). If it is determined that they have been operated (S3: Yes), the CPU 73 determines whether the operation direction of the operation levers 20 and 30 is the +Z direction, that is, whether it is the upward direction (S4). Here, if the CPU 73 determines that it is the +Z direction (S4: Yes), the electric motor 6 is reversely rotated at a rotational speed corresponding to the displacement amount of the operation levers 20 and 30 (S5). As a result, the first arm 7 rises, and the object to be conveyed L rises. Here, the rotational direction of the electric motor 6 is such that the rotational direction for lowering the first arm 7 is the forward rotation, and the rotational direction for raising the first arm 7 is the reverse rotation. Subsequently, the CPU 73 calculates the rotational speed (rotation angle) of the electric motor 6 based on the encoder value obtained from the electric motor 6, and determines whether the object to be conveyed L has reached the first position based on the calculated rotational speed (rotation angle) (S6).

[0075] Here, if the CPU 73 determines that the object to be conveyed L has reached the first position (S6: Yes), the rotational speed of the electric motor 6 is decelerated from the first rotational speed N1 to the second rotational speed N2 (<N1) (S7). For example, the first position is the upper end when conveying the object to be conveyed L, and is a position lower than the upper limit of the rise of the first arm 7. By setting the first position in this way, the electric motor 6 can be decelerated before the first arm 7 reaches the upper end, so there is no risk that the object to be conveyed L sways due to its own inertia or the entire conveying device 1 sways due to the sudden stop of the electric motor 6.

[0076] Also, in S4, when the CPU 73 determines that the operation directions of the operation levers 20 and 30 are not in the +Z direction, that is, downward (S4: No), it rotates the electric motor 6 forward at a rotational speed corresponding to the displacement amount of the operation levers 20 and 30 (S8). As a result, the first arm 7 descends, and the object L to be conveyed descends. Subsequently, when the CPU 73 determines that the object L to be conveyed has reached the second position (S9: Yes), it decelerates the rotational speed of the electric motor 6 from the first rotational speed N1 to the second rotational speed N2 (<N1) (S10). For example, the second position is the lower end when conveying the object L to be conveyed, and is a position higher than the lower limit of the descent of the first arm 7. By setting the second position in this way, since the electric motor 6 can be decelerated before the first arm 7 reaches the lower end, there is no possibility that the object L to be conveyed sways due to its own inertia or the entire conveying device 1 sways due to the sudden stop of the electric motor 6.

[0077] Subsequently, the CPU 73 determines whether the drive switch 22 (Fig. 3) has turned OFF (S11 in Fig. 8). If it determines that it has turned OFF (S11: Yes), it stops the electric motor 6 to stop the raising and lowering of the first arm 7, and activates each electromagnetic brake 3, 12, 14 to stop the turning of the conveying unit 90 and the second arm 11, and stop the pivoting of the third arm 15 (S12). That is, it controls so that the object L to be conveyed cannot be conveyed. In this way, by operating the stop switch 23, each electromagnetic brake 3, 12, 14 can be activated simultaneously. Therefore, when each electromagnetic brake 3, 12, 14 is activated, there is no possibility that the conveying unit 90 turns due to the inertia of the object L to be conveyed, or the first arm 7 or the second arm 11 turns, or the third arm 15 pivots, resulting in a deviation in the stopping distance of the object to be conveyed.

[0078] If the CPU 73 determines in S11 that the drive switch 22 is not turned off (S11: No), it determines whether the emergency stop switch 33 (FIG. 3) is turned on (S13). If the CPU 73 determines that the emergency stop switch 33 is turned on (S13: Yes), it stops the electric motor 6 to stop the lifting and lowering of the first arm 7, and it operates the electromagnetic brakes 3, 12, and 14 to stop the rotation of the conveyor 90 and the second arm 11, and to stop the rotation of the third arm 15 (S12). In other words, it controls so that the conveying object L cannot be conveyed. Next, the CPU 73 turns on the abnormality notification lamp 32a (FIG. 3) (S15) to notify that the emergency stop switch 33 has been operated.

[0079] Next, the CPU 73 judges whether the abnormality reset switch 32 has been operated (S16), and if it is judged that it has been operated (S16: Yes), it resets the computer program that has been executed up to that point (S17). Next, the CPU 73 judges whether the limit load has been detected, that is, whether the transport object L held by the holding unit 17 is equal to or greater than the limit load, based on the data acquired from the load cell 50 for the hoist (S18). Here, if the CPU 73 judges that the limit load has been detected (S18: Yes), it stops the electric motor 6 to stop the lifting and lowering of the first arm 7 (S19), and outputs an alarm sound from the alarm sound output unit 93 (FIG. 6) to notify that the transport object L is equal to or greater than the limit load (S20). This prevents the electric motor 6 from being overloaded, and can notify that the transport object L is overweight. In addition, if the object L to be transported is raised and lowered multiple times along the transport path of the object L, the above-mentioned first position and second position can be set multiple times, and the speed of the electric motor 6 can be controlled for each position.

[0080] [Conveying range and usage examples of conveying device 1] Next, the conveying range and an example of use of the conveying device 1 will be described with reference to FIG. The conveying device 1 is disposed at the side of an automobile assembly line 100. The rails 2, 2 are disposed parallel to the assembly line 100, and the conveying section 90 is movable parallel to the assembly line 100. A worker uses the conveying device 1 to convey an object L to be conveyed, such as a fuel tank, a tire, or a window glass, toward the assembly line 100 and assembles it on an automobile conveyed along the assembly line 100. In the figure, the reference symbol 7a denotes a projected image of the first arm 7 when the first arm 7 is vertically projected onto a horizontal plane (a plane on which the second arm 11 horizontally rotates) on which the second arm 11 exists. As shown by a solid line in the figure, the conveying device 1 can create a configuration in which the projected image 7c of the first arm 7 and the second arm 11 are linear.

[0081] That is, a configuration can be created in which the angle between the projection image 7c of the first arm 7 and the second arm 11 is 180 degrees. In other words, when the conveying device 1 is viewed in a plan view from directly above, the first arm 7 and the second arm 11 appear to be linear. In the figure, the dashed line C is the center line of the linear first arm 7 and the second arm 11. When the conveying unit 90 rotates in the horizontal direction (the direction indicated by the arrow D1 or the arrow D2 in the figure) in this configuration, the conveying unit 90 rotates with the maximum rotation radius. In addition, when the angle between the projection image 7c of the first arm 7 and the second arm 11 is reduced, the rotation radius of the conveying unit 90 is reduced. That is, the conveying device 1 can adjust the rotation radius to a desired length by adjusting the angle between the projection image 7c of the first arm 7 and the second arm 11 to a desired angle, and therefore the conveying range of the conveying object L can be adjusted to a desired range.

[0082] In the figure, the area indicated by E1 indicates a working area close to the assembly line 100 as viewed from the center line C, and the area indicated by E2 indicates a working area far from the assembly line 100 as viewed from the center line C. Hereinafter, as shown in the projected image 7c of the first arm 7 and the second arm 11 illustrated in the working area E1, the bending direction of the first arm 7 and the second arm 11 when the second arm 11 is rotating toward the assembly line 100 ahead of the first arm 7 is defined as a positive bending direction, and the bending angle is defined as α. Also, as shown in the projected image 7c of the first arm 7 and the second arm 11 illustrated in the working area E2, the bending direction of the first arm 7 and the second arm 11 when the first arm 7 is rotating toward the assembly line 100 ahead of the second arm 11 is defined as a reverse bending direction, and the bending angle is defined as β.

[0083] As shown in the figure, when an object L to be transported is supplied to the working area E1, the first arm 7 and the second arm 11 are bent in the positive bending direction and the bending angle α does not reach 180 degrees, so that the object L to be transported can be transported over the shortest distance toward the assembly line 100 and assembled into an automobile coming down the assembly line 100. On the other hand, as shown in working area E2, when the first arm 7 and the second arm 11 are bent in the negative bending direction, if the transport target L placed in working area E1 is held while maintaining that state and rotated toward the assembly line 100, the base of the second arm 11 rotates first, and the second arm 11 gets in the way of the assembly. For this reason, it is necessary to first straighten the first arm 7 and the second arm 11, and then return them to the state bent in the positive bending direction, which is time-consuming and reduces the work efficiency.

[0084] Therefore, as shown in the working area E1, if the transport target L is transported while maintaining the projected image 7c of the first arm 7 and the second arm 11 bent in the positive bending direction, the work efficiency can be improved. In other words, the work efficiency can be improved by using the first arm 7 in a range where the angle formed by the projected image 7c of the first arm 7 and the second arm 11 does not exceed 180 degrees when the first arm 7 is vertically projected onto the horizontal plane on which the second arm 11 exists, that is, in a range where the projected image 7c of the first arm 7 and the second arm 11 do not form a straight line. Furthermore, when the transported object L approaches the assembly position, the rotational speed of the electric motor 6 can be automatically reduced and the responsiveness of the electric motor 6 can be lowered, thereby improving the work efficiency of attaching the transported object L to the products flowing on the assembly line. Moreover, since the stopping position of the conveyed object L relative to the product can be controlled so as not to be too close or too short, the mounting accuracy can be improved.

[0085] [Other embodiments] (1) The control unit 70 may be configured to include a rotation angle detection unit that outputs a signal corresponding to the rotation angle of the rotating unit 19, detect the rotation angle of the rotating unit 19 based on the signal output from the rotation angle detection unit, and control the rotation speed of the electric motor 6 in accordance with the detected rotation angle. For example, a rotation sensor, a limit switch, or a proximity sensor may be provided in the first bearing 92 as the rotation angle detection unit, and the rotation sensor may be electrically connected to the control unit 70. By implementing this configuration, the control unit 70 can control the rotation speed of the electric motor 6 based on the rotation angle of the rotating unit 19 journaled by the first bearing 92. The rotation angle of the rotating part 19 is the rotation angle of the entire conveyance device 1, and the rotation angle determines the horizontal conveyable range of the conveyance object L. Also, the number of rotations (rotation angle) of the electric motor 6 determines the lifting position of the tip 7b of the first arm 7, that is, the vertical conveyable range of the conveyance object L. Therefore, according to the above configuration, even if the transportable range of the object L changes depending on the environment in which the conveying device 1 is installed or the type of object L, the change can be accommodated by controlling the rotation speed of the electric motor 6 based on the rotation angle of the rotating part 19, so there is no risk of the object L colliding with an obstacle or the like while being raised or lowered.

[0086] (2) The control unit 70 may be configured to include a rotation angle detection unit that outputs a signal corresponding to the rotation angle of the rotating unit 19, calculate the position of the transport object L based on the signal output from the rotation angle detection unit and the rotation speed of the electric motor 6, and determine whether the transport object L has reached a predetermined position based on the calculated position. For example, a rotation sensor, a limit switch, or a proximity sensor may be provided in the first bearing 92 as the rotation angle detection unit, and the rotation sensor may be electrically connected to the control unit 70. By implementing the above configuration, the control unit 70 can detect the spatial coordinates of the transport object L, and when it is determined that the transport object L has reached the target coordinates, control the electric motor 6 to decelerate the rotation speed of the electric motor 6 to a second rotation speed slower than the first rotation speed. In addition, the control unit 70 can control the electric motor 6 to reduce the responsiveness of the rotation speed to the displacement of the operating levers 20, 30. Therefore, the efficiency of the work of transporting the object L to the target position can be improved.

[0087] (3) The shape of the holding unit 17 can be changed depending on the transport object L to be held. For example, if the transport object L is a tire, the shape can be changed to one that allows the tire to be transported while being held. For example, a worker who mounts a tire on an automobile transports the tire to the mounting position while operating the operating levers 20, 30. At this time, the worker can operate the operating levers 20, 30 while facing the tire, and the movement of the worker's hand directly translates into the movement of the holding unit, making it easy to fine-tune the mounting position of the tire.

[0088] (4) A two-stage switch, a so-called double action switch, consisting of a drive switch 22 and a stop switch that perform switching operation by pressing the push button 21, can also be provided inside the first operating lever 20. The first-stage drive switch 22 is a switch for putting the electric motor 6 into a drivable state, and the second-stage stop switch 23 is a switch for stopping the electric motor 6 and for operating all the electromagnetic brakes.

[0089] (5) A configuration in which a trigger-type switch is provided on the circumferential surface of the first operating lever 20 instead of the push button 21 may be used. For example, a switch operable with a finger (e.g., index finger) other than the thumb of the hand gripping the first operating lever 20 may be provided on the circumferential surface of the first operating lever 20, and the electric motor 6 may be put into a drivable state when the switch is pulled, and the electric motor 6 may be stopped when the switch is released from being pulled during transport. Also, the electric motor 6 may be put into a drivable state when the switch is operated with a first stroke amount, and the electric motor 6 may be stopped when the switch is operated with a second stroke amount greater than the first stroke amount during transport.

[0090] (6) A range sensor for detecting obstacles present in the vertical direction may be provided on the third arm 15, and the electric motor 6 may be configured to stop when the range sensor detects an obstacle. By implementing this configuration, it is possible to prevent the conveying device 1 or the object L to be conveyed from colliding with obstacles present in the vertical direction.

[0091] (7) The second operating lever 30 can be configured so that the operating lever load cell 24 is fixed to a position where it is not displaced, and the operating lever load cell 24 detects only the displacement of the first operating lever 20. In other words, the second operating lever 30 can be configured so that it only serves to apply force to the third arm 15 in the horizontal direction.

[0092] (8) When the control unit 70 determines that the transport object L has reached a predetermined position away from the target position while the electric motor 6 is driven at the first rotation speed, the control unit 70 can also control the electric motor 6 to decelerate the rotation speed of the electric motor 6 stepwise to second to nth (n≧3) rotation speeds slower than the first rotation speed. In addition, when decelerating stepwise, the time during which the same speed is maintained per step can be set and changed. For example, the time during which the second rotation speed is maintained can be set to t1 time, the time during which the third rotation speed is maintained to t2 time, and the time during which the nth rotation speed is maintained to tn time. In this case, the times t2 to tn can be set to be the same, or can be set to gradually increase or decrease. In addition, the rotation speed can be configured to exponentially decrease throughout all steps or for each step. The above-described configuration can be adapted to the skill of the worker, the size and type of the transport object L, the lifting distance of the transport object L, the work environment, and the like.

[0093] (9) The control unit 70 controls the rotation speed of the electric motor 6 based on the operation signal output from the load cell 24 for the operation lever, and when it determines that the transport object L has reached a predetermined position away from the target position, it can also control the electric motor 6 so as to gradually reduce the responsiveness of the electric motor 6 to the displacement amount of the operation levers 20, 30. For example, in the first stage, the rotation speed of the electric motor 6 for a unit displacement amount m (for example, unit displacement length in the Z-axis direction) of the operation levers 20, 30 can be gradually decelerated from v1 to v2, in the second stage, from v2 to v3, and in the n-th stage, from v(n-1) to vn. In addition, the time required for deceleration in each stage can be the same for each stage, or can be different for each stage. In addition, it can be configured so that the responsiveness decreases exponentially throughout all stages or for each stage. The above-described configuration can be adapted to the skill of the worker, the size and type of the transport object L, the lifting distance of the transport object L, the work environment, and the like. [Explanation of symbols]

[0094] 1. Conveyor device 2 Rail 3 First electromagnetic brake 6 Electric motor 7 First Arm 10 Second bearing 11 Second Arm 12 Second electromagnetic brake 13 Third Electromagnetic Brake 14 Third Bearing 15 Third Arm 17 Holding part 18 Reducer 19 Rotating part 20 First operating lever 24 Load cell for operating lever 30 Second operating lever 50 Load cell for lifting loads 60 Limit Switch 70 Control section 90 Conveyor 91 Moving parts 92 First Bearing L Transport object

Claims

1. A conveying unit for conveying an object to be conveyed; an electric motor for driving the conveying unit; An operation unit; an operation signal output unit that outputs an operation signal indicating that the operation unit has been operated; A control unit that controls the electric motor based on the operation signal output from the operation signal output unit, The control unit is A conveying device characterized in that, when the electric motor is driven at a first rotational speed and it is determined that the object to be conveyed has reached a predetermined position away from a target position, the electric motor is controlled so as to decelerate the rotational speed of the electric motor to a second rotational speed slower than the first rotational speed.

2. A conveying unit for conveying an object to be conveyed; an electric motor for driving the conveying unit; An operation unit; an operation signal output unit that outputs an operation signal corresponding to a displacement amount of the operation unit; A control unit that controls the electric motor based on the operation signal output from the operation signal output unit, The control unit is A conveying device characterized by controlling the rotational speed of the electric motor based on the operation signal output from the operation signal output unit, and reducing the responsiveness of the electric motor to the amount of displacement of the operation unit when it is determined that the object to be conveyed has reached a predetermined position away from a target position.

3. The control unit is 2. The conveying apparatus according to claim 1, wherein the electric motor is controlled so that the rotation speed of the electric motor is gradually decreased when the object reaches the predetermined position.

4. The control unit is 3. The conveying apparatus according to claim 2, wherein the electric motor is controlled so that the responsiveness gradually decreases when the object reaches the predetermined position.

5. The transport device according to claim 2 , further comprising a setting unit for setting the responsiveness in a changeable manner.

6. a reducer for reducing the rotational speed of the electric motor is attached to an output shaft of the electric motor; The conveying unit is a rotation part attached to an output shaft of the reducer and rotatable in the same direction as a rotation direction of the output shaft; a first bearing that supports the rotating part at a predetermined position so that the rotating part can rotate in a horizontal direction; a first arm having a base end attached to the rotating part and a tip end capable of ascending and descending by rotation of the rotating part; a second arm having a base end attached to the tip end of the first arm; a second bearing attached between a tip end of the first arm and a base end of the second arm such that the second arm can rotate horizontally about the base end of the second arm; a third arm having an upper end attached to the tip of the second arm and suspended from the tip; a third bearing attached between a tip end of the second arm and an upper end of the third arm such that the third arm is rotatable in a horizontal direction around the upper end of the third arm; a holding portion attached to the third arm for holding the object to be transported, 3. The transport device according to claim 1, wherein the operation unit is attached to the third arm.

7. The reducer includes:

7. The conveying device according to claim 6, wherein an input shaft from the electric motor and an output shaft after reduction are structured to be aligned in the same straight line.

8. The control unit is 7. The conveying device according to claim 6, further comprising a rotation angle detection unit that outputs a signal corresponding to a rotation angle of the rotating unit, the rotation angle of the rotating unit is detected based on the signal output from the rotation angle detection unit, and the number of rotations of the electric motor is controlled in response to the detected rotation angle.

9. a sensor provided between a lower end of the third arm and the holding portion, the sensor outputting a signal corresponding to a weight of the object held by the holding portion; a notification unit that notifies a user when the control unit determines that the weight applied to the holding unit exceeds a predetermined weight based on the signal output from the sensor; and 7. The transport device according to claim 6, further comprising:

10. a first electromagnetic brake is attached to the first bearing to control the horizontal rotation of the rotating part; a second electromagnetic brake is attached to the second bearing to control horizontal rotation of the second arm about its base end; a third electromagnetic brake is attached to the third bearing to control horizontal rotation of the third arm about its upper end; The operation unit includes:

7. The transport device according to claim 6, further comprising a brake switch for simultaneously activating the first electromagnetic brake, the second electromagnetic brake and the third electromagnetic brake.

11. The control unit is The conveying device according to claim 6, further comprising a rotation angle detection unit that outputs a signal corresponding to a rotation angle of the rotating unit, calculates a position of the object to be conveyed based on the signal output from the rotation angle detection unit and the rotation speed of the electric motor, and determines whether the object to be conveyed has reached the predetermined position based on the calculated position.

12. a rotation speed of the electric motor and a rotation angle of the rotating part are in a corresponding relationship; a limit switch that operates when the rotation angle of the rotating part reaches a predetermined angle and stops the electric motor, The limit switch is The conveying device according to claim 6, characterized in that even if the rotation speed of the electric motor reaches a preset upper limit rotation speed but this is not detected by the control unit, it operates when the rotation angle of the rotating unit reaches the specified rotation angle.

13. The operation unit includes: an operating lever shaped to be held in the palm of an operator who uses the conveying device to convey the object to be conveyed, 3. The transport device according to claim 2, wherein the transport unit can be moved in a horizontal direction by the operator applying a force in a horizontal direction to the operating lever held in the palm of his / her hand.

14. The operating lever is The device includes a first operating lever and a second operating lever that are parallel to each other, At least one of the first operating lever and the second operating lever is provided with a switch that is operated to set the electric motor in a drivable state, The operation signal output unit is 14. The transport device according to claim 13, wherein the operation signal is output corresponding to a displacement amount of at least one of the first operation lever and the second operation lever.

15. the first bearing, the second bearing, and the third bearing each have a hollow center, and the first electromagnetic brake, the second electromagnetic brake, and the third electromagnetic brake each have a hollow center, 11. The transport device according to claim 10, wherein wiring electrically connecting the operation unit, the operation signal output unit, and each electromagnetic brake to the control unit passes through each hollow portion of each bearing and each electromagnetic brake.

16. A pair of rails parallel to each other; a moving member provided on the rail so as to be movable along the rail, The first bearing is attached to the moving member, The moving member includes: Rollers for moving the moving member along the rails are provided at locations corresponding to the rails, The rail has: A track portion for allowing the rollers to roll along the rail is formed along each rail, The roller is 7. The conveying device according to claim 6, wherein the guide members are provided so as to sandwich the upper and lower surfaces of the track portion.

17. 7. The transport device according to claim 6, wherein the second arm is capable of rotating horizontally at least 360 degrees about the second bearing.

18. 7. The transport device according to claim 6, wherein the third arm is rotatable horizontally at least 360 degrees about the third bearing.

19. The conveying device according to claim 6, characterized in that when the first arm is vertically projected onto a horizontal plane on which the second arm exists, the angle formed between the projected image of the first arm and the second arm does not exceed 180 degrees when used.

20. The conveying device is arranged along a product assembly line, 20. The conveying apparatus according to claim 19, wherein the object to be conveyed is an object to be attached to the product transported on the assembly line.

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