Magnet conveyance positioning device

A magnet conveyance positioning device including a conveyance unit and an attachment device attached to the conveyance unit to move integrally with the conveyance unit. The attachment device includes a support unit abutting on a object and supporting the conveyance unit from the object, a holding unit provided movably relative to the support unit to detachably hold the magnet, and a driving unit moving the holding unit so that the magnet approaches the object in a state where the support unit is abutted on the object.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnet conveyance positioning device that positions and mounts a magnet on an object.

2. Description of the Related Art

Generally, a magnet is manually mounted on an object by using a jig. In order to accurately mount a magnet, for example, Japanese Laid-open Patent Publication No. 11-187627 (JP11-187627A) describes a positioning jig for positioning and mounting the magnet on the object.

However, the configuration that manually mounts the magnet on the object by using the jig, as described in JP11-187627A, requires a lot of labor and time for attaching or detaching the jig, and thus it is difficult to efficiently mount the magnet. On the other hand, in the configuration that conveys the magnet to the object and mounts it on the object by a robot or the like without using any jig or human hands, attraction force between the magnet and the object may cause staggering of an end portion of the robot. Consequently, it is difficult to accurately position the magnet.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a magnet conveyance positioning device for positioning and mounting a magnet on an object includes a conveyance unit, and an attachment device attached to the conveyance unit to move integrally with the conveyance unit. The attachment device includes a support unit abutting on the object and supporting the conveyance unit from the object, a holding unit provided movably relative to the support unit to detachably hold the magnet, and a driving unit moving the holding unit so that the magnet approaches the object in a state where the support unit is abutted on the object.

DETAILED DESCRIPTION

Hereinafter, the embodiments of the present invention will be described referring toFIGS. 1 to 6.FIG. 1is a schematic diagram illustrating a configuration of a magnet conveyance positioning device100according to an embodiment of the present invention. The magnet conveyance positioning device100is configured to position and mounts a magnet1on an object2. The object2is a relatively large magnetic structure such as a rotor of a thermal power generator. InFIG. 1, the magnet1is adsorbed on an inner wall surface of the object2by its own magnetic force. Hereinafter, for convenience of explanation, an up-and-down direction (vertical direction) and a left-and-right direction (horizontal direction) are defined as illustrated, and a configuration of each unit will be described according to these definitions. InFIG. 1, the object2extends in the horizontal direction, and the magnet1is mounted on a top surface of the object2.

As illustrated inFIG. 1, the magnet conveyance positioning device100includes a conveyance unit5and an attachment device10attached to the conveyance unit5to move integrally with the conveyance unit5. The conveyance unit5is configured, for example, by a multijoint industrial robot, and the attachment device10is attached to an end portion of a robot hand. The conveyance unit5is moved by driving a servo motor35(illustrated inFIG. 2), and a position and posture of the attachment device10are changed to a desired position and posture by the operation of the conveyance unit5. InFIG. 1, the attachment device10is directed downward so as to have a vertical posture.

The attachment device10includes a base unit11fixed to the conveyance unit5, a frame unit12disposed below the base unit11, a support unit13extending downward from the frame unit12, a connection unit14connecting the base unit11and the frame unit12, a gripping unit15for gripping the magnet1, and an lifting mechanism20for lifting the gripping unit15. The attachment device10has a left-and-right symmetrical shape as a whole.

The base unit11is a circular or rectangular plate member with a predetermined thickness which extends in the horizontal direction. The conveyance unit5is attached to a center part of a top surface of the base unit11. At both left and right ends of the base unit11, through-holes11awith a circular cross section which are penetrated in the up-and-down direction, are opened. The frame unit12includes an upper plate121and a lower plate122extending in the horizontal direction, and a pair of left and right vertical plates123and124for connecting the upper plate121and the lower plate122, and has a rectangular frame shape as a whole. In the lower plate122, a pair of left and right guide holes122awith a circular cross section which are penetrated in the up-and-down direction, are opened. The support unit13is a pair of left and right plate members which project downward from both left and right ends of a lower end surface of the lower plate122.

The connection unit14includes a cylindrical unit141inserted into the through-hole11aof the base unit11, and a stopper142provided on an upper end surface of the cylindrical unit141. The stopper142is larger in diameter than the cylindrical unit141. A lower end surface of the cylindrical unit141is fixed to a top surface of the upper plate121of the frame unit12. The cylindrical unit141is longer than the plate thickness of the base unit11by a predetermined length ΔL, and the base unit11is movable in the up-and-down direction along the cylindrical unit141within the range of ΔL. InFIG. 1, the frame unit12is hung from the base unit11via the connection unit14, and an upper end surface of the base unit11abuts on the stopper142. In this case, a length from the upper end surface of the base unit11to a lower end surface of the support unit13, i.e., a total length of the attachment device10is L0.

The gripping unit15is disposed between the left side support unit13and the right side support unit13. The gripping unit15includes an air cylinder151which is expanded and contracted in the left-and-right direction, and a pair of left and right gripping claws152attached to the lend portion of the air cylinder151. It is possible to grip the magnet1with the pair of gripping claws152by elongating and contracting the air cylinder151. The gripping claw152is configured by a nonmagnetic material such as stainless steel. The units (frame unit12, support unit13, and the like) other than the gripping claw152can be configured by magnetic materials such as iron, because they are arranged away from the magnet1and attraction force from the magnet1is small.

The lifting mechanism20includes a ball screw21, a servo motor22for driving the ball screw21rotationally, a nut23engaged with the ball screw21, a pair of upper and lower lifting plates24and25connected to an upper end and a lower end of the ball screw21, and a pair of left and right rods26which move in the up-and-down direction along the guide holes122aof the lower plate122of the frame unit12. The nut23is fixed to the lower plate122of the frame unit12. The air cylinder151is mounted on a lower end surface of the lifting plate25, and lower ends of the rods26are fixed to both left and right ends of the lifting plate25.

When rotating the ball screw21by driving the servo motor22, the ball screw21move in the up and down direction and the gripping unit15lifts integrally with the lifting plate25in a space16between the left and right support plates13. At this time, the left and right rods26move in the up-and-down direction along the guide holes122a, and accordingly the lifting plate25can be lifted while its horizontal posture is maintained.

The magnet conveyance positioning device100according to the embodiment of the present invention automatically conveys the magnet1disposed in a parts storage or the like (first position) to the object2, and automatically attaches the magnet1to a predetermined position (second position) of the object2.FIG. 2is a block diagram illustrating a control configuration of the magnet conveyance positioning device100according to the embodiment of the present invention. A controller30is configured by including an arithmetic processing unit that includes a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and other peripheral circuits. A gripping switch31for detecting presence of gripping of the magnet1by the gripping claws152and an input unit32configured to input a conveyance start command or the like of the magnet1are connected to the controller30.

In a memory of the controller30, the first position in which the magnet1is disposed, the second position to which the magnet1is fitted, the total length LO of the attachment device10, and the like, are stored in advance. The controller30executes predetermined processing based on signals from the gripping switch31and the input unit32and various kinds of information stored in the memory, and outputs control signals to the robot driving servo motor35, and the servo motor22and the air cylinder151provided in the attachment device10.

FIG. 3is a flowchart illustrating an example of processing executed by the controller30. The processing illustrated in the flowchart is started, for example, when a conveyance start command of the magnet1is input from the input unit32. In an initial state, the gripping unit15is raised at maximum, and the air cylinder151is elongated at maximum. In step S1, magnet gripping processing for gripping the magnet1disposed in the parts storage is performed.

FIG. 4is a flowchart illustrating a specific content of the magnet gripping processing. In step S1A, a control signal is output to the robot driving servo motor35based on the information stored in the memory in advance to move the attachment device10above the first position. In step SIB, a control signal is output to the servo motor22to lower the gripping unit15toward the magnet1. In step SIC, a control signal is output to the air cylinder151, and the air cylinder151is contracted to shorten a distance between the pair of gripping claws152. In step S1D, whether or not the gripping switch31is on, i.e., whether or not the magnet1has been gripped by the gripping claws152, is determined. When a positive decision is made at step S1D, the processing proceeds to step S1E, and a control signal is output to the servo motor22to raise the gripping unit15.

After the above magnet gripping processing ends, the processing proceeds to step S2illustrated inFIG. 3. In step S2, a control signal is output to the servo motor35based on the information stored in the memory in advance to move the attachment device10above the second position while gripping the magnet1. In other words, as illustrated inFIG. 5A, the conveyance unit5is moved in view of the total length L0 of the attachment device10so that a center of the attachment device10is positioned above a second position Pa on the top surface of the object2, for example, the lower end surface of the support unit13is positioned above the object2by a predetermined amount L1.

Then, in step S3, a control signal is output to the servo motor35to lower the attachment device10, and the lower end surface of the support unit13abuts on the top surface of the object2. In this case, if the attachment device10is lowered by the predetermined amount L1, the lower end surface of the support unit13abuts on the top surface of the object2. However, in this embodiment, a lowering amount of the attachment device10is set to larger than L1 by a predetermined amount L2 (<ΔL) so that a sufficient pressing force from the support unit13acts on the object2. Therefore, as illustrated in FIG.5B, the top surface of the base unit11is positioned below the stopper142of the connection unit14by the predetermined amount L2. In a state illustrated inFIG. 5B, the magnet1is sufficiently away from the object2. Thus, attraction force between the magnet1and the object2is small, and position setting of the conveyance unit5is easy.

Then, in step S4, a control signal is output to the servo motor22to lower the gripping unit15to adsorb the magnet1on the second position Pa of the top surface of the object2. When the magnet1approaches the object2, the attraction force between the magnet1and the object2increases. In this state, as illustrated inFIG. 5C, the conveyance unit5is supported by the object2via the support unit13. In other words, the support unit13regulates a position of the conveyance unit5with respect to the object2. Therefore, it is possible to prevent the conveyance unit5from being pulled toward the object2side by the attraction force, and the magnet1can be accurately positioned and mounted on the top surface of the object2. On the other hand, without the support unit13, the position and the posture of the conveyance unit5are made unstable due to the attraction force between the magnet1and the object2, and it is difficult to accurately position the magnet1.

Then, in step S5, a control signal is output to the air cylinder151to release the gripping claws152. Therefore, as illustrated inFIG. 5D, the gripping claws152move away from the magnet1and the magnet1is held on the top surface of the object2by its own magnet force. In this case, since the gripping claws152are configured by a nonmagnetic material, the gripping claws152can be easily separated from the magnet1.

Finally, in step S6, a control signal is output to the servo motor22to raise the gripping unit15, and a control signal is output to the servo motor35to raise the attachment device10. Therefore, as illustrated inFIG. 5E, the attachment device10retracts from the object2, and the fitting of the magnet1to the object2is completed.

In this embodiment, the following operational effects can be achieved.(1) The magnet conveyance positioning device100includes the conveyance unit5and the attachment device10attached to the conveyance unit5. The attachment device10includes the support unit13which abuts on the object2and supports the conveyance unit5from the object2, the gripping unit15provided movably relative to the support unit13to detachably hold the magnet1, and the lifting mechanism20for lifting the gripping unit15so that the magnet1approaches the object2in a state where the support unit13is abutted on the object2. Therefore, it is possible to prevent the conveyance unit5from being pulled toward the object2side by the attraction force between the magnet1and the object2when the magnet1is attached to the object2, and to accurately position and mount the magnet1on the object2.(2) The connection unit14is provided between the base unit11and the frame unit12so that the support unit13is movable within the predetermined range ΔL in a predetermined direction (extending direction of support unit13) relative to the base unit11. Therefore, it is possible to reduce shock when the support unit13abuts on the object2.(3) When the conveyance unit5is configured by a general-purpose robot, automatic conveyance of the magnet1can be easily and inexpensively performed.(4) As the lifting mechanism20, the ball screw21is driven by the servo motor22to lift the gripping unit15. Thus, an approach speed of the magnet1to the object2can be finely controlled. Accordingly, the magnet1can be slowly attached to the object2, and shocks during fitting (adsorption) of the magnet1can be reduced.(5) The servo motor22of the lifting mechanism20and the robot driving servo motor35are controlled by the same controller30. Thus, the robot and the lifting mechanism20can be easily controlled in synchronization, and the magnet1can be efficiently attached to the object2.

In the above embodiment, the magnet1is configured to be gripped by the gripping unit15. However, any configuration of a holding unit can be employed as long as the holding unit is provided movably relative to the support unit13and detachably holds the magnet1. In the above embodiment, the gripping unit15is configured to be lifted by the servo motor22. However, any configuration of a driving unit can be employed as long as the driving unit moves the holding unit (gripping unit15) so that the magnet1approaches the object2in a state where the support unit13is abutted on the object2.

FIG. 6illustrates an example of using an air cylinder27as a driving unit in place of the servo motor22. The air cylinder27includes a cylinder tube271and a cylinder rod272which is expanded and contracted from the cylinder tube271. A plate28is fixed inside a frame unit12, and the cylinder tube271is supported on a top surface of the plate28. The cylinder rod272penetrates the plate28and a lower plate122, and a lifting plate25is attached to the end portion of the cylinder rod272. When the air cylinder27expands and contracts, a gripping unit15is lifted. Therefore, it is possible to attach a magnet1to an object2in a state where a support unit13is abutted on the object2. Thus, when the driving unit is configured by the air cylinder27, the configuration can be simplified and made inexpensive.

In the above embodiment, the connection unit14is provided in the attachment device10, so that the support unit13is securely abutted on the object2. However, a configuration of a movement permission unit is not limited hereto as long as the movement permission unit is provided between the conveyance unit5and the support unit13and the movement of the conveyance unit5is permitted in a state where the support unit13is abutted on the object2. The connection unit14may be omitted, and presence of abutment of the support unit13may be detected by a contact detector, a load detector, or the like. In the above embodiment, the conveyance unit5is configured by the robot. However, a configuration of the conveyance unit is not necessarily limited hereto. In the above embodiment, the servo motor22(first servo motor) of the lifting mechanism20and the robot driving servo motor35(second servo motor) are controlled by the same controller30(control unit). However, these motors may be controlled by separate control units.

The above embodiment and one or a plurality of modified examples may be arbitrarily combined.

According to the present invention, the support unit which abuts on the object and supports the conveyance unit from the object is provided, and the magnet approaches the object in a state where the support unit is abutted on the object. Thus, it is possible to prevent the conveyance unit from being pulled toward the object side by the attraction force between the magnet and the object when the magnet is attached to the object, and to accurately position and attach the magnet to the object.

While the present invention has been described with reference to the preferred embodiments thereof, it will be understood, by those skilled in the art, that various modifications and changes may be made thereto without departing from the scope of the appended claims.