JP6998750B2 - Screw turning device and method of transporting and tightening screws - Google Patents

Description

The present invention mainly relates to a screwdriver.

Conventionally, for example, in a factory production line, there are many steps of transporting a screw to a desired position for tightening work and tightening the screw at the position of the transport destination.

When such a process is performed using one robot, generally, a gripper is attached to the hand of the robot, the screw is conveyed to a predetermined position by the gripper, and then a screwdriver is used instead of the gripper. It is conceivable to attach it to the hand and tighten the screw with the screwdriver. However, in that case, it is necessary to replace the tool at the hand of the robot, and there is a problem that the work of transporting the screw to a desired place and screwing it cannot be performed continuously.

Therefore, it is conceivable that both the screw transfer and the tightening work can be performed only by the gripper attached to the hand of the robot. However, in that case, there is a problem that the holding force (grip force) of the screw at the time of tightening cannot be sufficiently secured and the screw slips.

Therefore, it is conceivable to use a screwdriver (screw member tightening device) as described in Patent Document 1 to transport the screw to a desired place and screw it in. The screw member tightening device described in Patent Document 1 is provided with a magnet for holding a screw at the tip of a bit of a screwdriver, and can hold the screw at the tip of the bit to perform tightening work. However, in the configuration of Patent Document 1, when the material of the screw is a non-magnetic material (for example, resin or aluminum), it cannot be dealt with, and the versatility is low.

Alternatively, it is conceivable to use a screwdriver tool (screw holder for a screwdriver, etc.) as described in Patent Document 2 or 3 to hold and transport the screw. The screw holders for drivers described in these patent documents are provided with an elastic body at the holding portion at the tip of the driver, and the elastic body is deformed to grip the head of the screw. However, in the configuration of Patent Document 2 or 3, a mechanical operation is required to switch between holding and releasing the screw, and once the screw is held, manual intervention is required to release the holding, and the screw is transported and tightened. It was not possible to carry out the work continuously at high speed.

Alternatively, it is conceivable to use a screw suction holding tool (screw suction holding device of a power type screwdriver) as in Patent Document 4 to suck the screw to hold and transport the screw. The screw suction holding device described in Patent Document 4 includes a suction holding cylinder that covers the entire head of the screw, and can suck and hold the head of the screw by creating a negative pressure inside the suction holding cylinder. , And. However, in the configuration disclosed in Patent Document 4, since it is necessary to arrange the suction holding cylinder so as to wrap the entire head of the screw (entire circumference), there is a problem that the suction holding tool becomes large. rice field. Also, therefore, in a narrow environment, such as when removing screws from a pallet where screws are lined up at narrow intervals, or when screwing screws into a place where other workpieces are nearby and crowded. I couldn't handle the work at. In addition, the tool and the work may interfere with each other and damage the work. Furthermore, in the configuration disclosed in Patent Document 4, the rotation phase of the screw head is not taken into consideration when the screw head is sucked by making the inside of the suction holding cylinder a negative pressure, so that the driver is used in the subsequent process. It is necessary to perform the work of matching the phase of the bit with the phase of the screw head, and there is room for improvement in order to carry out the work of transporting the screw to a desired place and screwing it continuously at high speed.

Japanese Unexamined Patent Publication No. 2004-142701. Japanese Patent Application Laid-Open No. 2003-159663 Japanese Unexamined Patent Publication No. 2014-233810 Japanese Unexamined Patent Publication No. 10-156741

The present invention has been made in view of the above circumstances, and an object of the present invention is to enable a continuous high-speed screwing operation of transporting a screw to a desired place.

The problem to be solved by the present invention is as described above, and next, the means for solving this problem and its effect will be described.

From the viewpoint of the present invention , a screwdriver having the following configuration is provided. That is, this screwdriver includes a main body and a screwdriver tool. The main body includes a power source capable of generating torque and a negative pressure supply port . The screwdriver is attached to the body. The screw turning tool includes a shaft body and a contact member. The shaft body has a tip portion having a shape corresponding to a concave portion formed in the screw head of the screw, and is rotated by the torque . The contact member can form a closed space by contacting the top surface of the screw head. A suction port for sucking air is opened at the tip of the shaft body. The suction port is configured to be able to suck air in the space formed by the contact member. Inside the shaft body, a flow path is formed to allow air sucked from the suction port to pass toward the negative pressure supply port. The contact member is penetrated through the shaft body and is fixed to the outer peripheral surface of the shaft body while maintaining airtightness. In the shaft body, the tip end side and the side far from the tip end portion of the contact member are exposed to the outside. It is provided with an urging member that exerts an urging force that pushes back the shaft body when the shaft body is relatively pushed by the screw head. When the shaft body is relatively pushed in, the contact member is also pushed in integrally with the shaft body.

As a result, a suction flow from the suction port to the negative pressure supply port is generated at the tip of the shaft, and the screw is held by the screwdriver with the tip of the shaft inserted into the recess of the screw head. can do. As a result, a series of operations of holding the screws, transporting them to a desired place, and screwing them can be performed without exchanging tools, and the work speed can be increased. In addition, the suction port is formed at the tip of the shaft body, and the air sucked by the suction port passes through the inside of the shaft body and flows to the negative pressure supply port, so that a compact configuration can be realized and a narrow space can be realized. But you can easily turn the screw.

According to the present invention, the work of transporting a screw to a desired place and screwing it can be continuously performed at high speed.

The schematic diagram which shows the overall structure of the robot to which the screw turning tool which concerns on one Embodiment of this invention is attached. It is an enlarged partial sectional view of the screw turning tool and the connection part between it and a robot body, and is the figure which shows the state when the tip part of a screw turning tool is brought close to a screw head in order to hold a screw. The figure which shows the state when a screw is held at the tip of a screw turning tool. The figure which shows the modification of the suction pad provided in the screw turning tool.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an overall configuration of a robot 1 to which a screwdriver tool 10 according to an embodiment of the present invention is attached. FIG. 2 is an enlarged partial cross-sectional view of the screw turning tool 10 and the connection portion between the screw turning tool 10 and the robot body 2, and the tip portion 11t of the screw turning tool 10 is brought close to the recess 7a of the screw head in order to hold the screw 7. It is a figure which shows the state of time.

The robot 1 shown in FIG. 1 functions as a screwdriver by attaching the screwdriver tool 10 according to the present embodiment as a tool. The robot 1 is movably installed on the production line of a factory that manufactures industrial products such as transport machines and electrical equipment, on the side of a transport device that transports an unfinished work W from the upstream side to the downstream side. .. The robot 1 of the present embodiment carries out a screw 7 taken from a predetermined place such as the pallet 6 to a desired place on the work W and screwes the screw 7.

The robot 1 mainly includes a robot main body (main body) 2, a robot controller (control unit) 4, and a master side coupler 8.

The robot main body 2 is configured in the form of an articulated arm having a plurality of joints 21, 21, ... And arms 29, 29. Each joint 21 is provided with an actuator. These actuators are appropriately driven in response to a command signal from the robot controller 4, so that each arm 29 rotates at a desired speed and by a desired angle.

The robot controller 4 is configured as a computer and includes a CPU, a ROM, a RAM, and the like. Further, the ROM stores (stores) an appropriate operation program for operating the robot main body 2 based on the control data. By the cooperation of this software and hardware, the robot controller 4 is appropriately determined by appropriately operating the screw turning tool 10 as an end effector attached to each arm 29 of the robot body 2 and the tip of the robot body 2. It is possible to function as a command unit for sending a command signal for causing the robot main body 2 to perform the performed work.

An electric motor (power source) 22 capable of generating torque is mounted on the tip (wrist) of the robot body 2. The output shaft of the electric motor 22 projects from the wrist of the robot body 2 to the tip side (end effector side). Electric power from the power source 5 is supplied to the electric motor 22 via a cable. This cable is routed along the articulated arm of the robot body 2. With such a configuration, electric power is supplied to the electric motor 22 to generate torque (rotational force) transmitted to the end effector. The electric motor 22 is appropriately driven in response to a command signal from the robot controller 4.

A coupler 8 on the master side is attached to the output shaft of the electric motor 22 so as to rotate integrally with the output shaft. In other words, the master side coupler 8 is attached so as not to rotate relative to the output shaft of the electric motor 22. The master side coupler 8 is formed with a flow path 8a forming a part of the flow path for flowing the suction flow generated at the tip of the end effector to the robot main body 2 side (see FIG. 2). A negative pressure supply port 8b is formed at the downstream end of the flow path 8a in the direction in which the suction flow flows. One end of an air tube 23 forming a part of a flow path for flowing a suction flow from the tip end portion of the end effector to the robot main body 2 side is connected to the negative pressure supply port 8b. The air tube 23 is arranged along the articulated arm of the robot body 2 in the same manner as the cable described above. The other end of the air tube 23 is connected to the negative pressure generator 24 mounted on the robot body 2 (see FIG. 1).

The negative pressure generator 24 of the present embodiment is configured by a vacuum ejector. Negative pressure is generated in the negative pressure generator 24 by supplying the compressed air distributed from the compressed air source (compressor) 31 in the factory to the robot 1 (robot body 2) to the negative pressure generator 24. Will be done. As a result, a suction flow can be generated at the tip of the end effector and flow toward the negative pressure generator 24. In other words, by generating a negative pressure with the negative pressure generator 24, it is possible to take in air from the tip of the end effector and flow it toward the negative pressure generator 24 via the negative pressure supply port 8b. be. In other words, the negative pressure generated by the negative pressure generator 24 can be supplied to the tip end portion of the end effector via the negative pressure supply port 8b.

A tool-side coupler 9 paired with the master-side coupler 8 is connected to the master-side coupler 8 so as to be relatively non-rotatable. The tool-side coupler 9 is formed with a flow path 9a forming a part of the flow path for flowing the suction flow generated at the tip of the end effector to the robot body 2 side (see FIG. 2). By attaching the tool-side coupler 9 to the master-side coupler 8, the flow path 8a and the flow path 9a are connected.

A fixing member 19 for fixing the screwdriver tool 10 to the tool-side coupler 9 is attached to the end surface of the tool-side coupler 9 on the side opposite to the side connected to the master-side coupler 8. The fixing member 19 is fixed to the end face of the tool-side coupler 9 by using a fastener such as a bolt. The fixing member 19 of the present embodiment is configured to have a short polygonal columnar shape (regular octagonal columnar shape in the present embodiment), and is attached so that its central axis is arranged on the axis of the output shaft of the electric motor 22.

Inside the fixing member 19, a flow path for flowing the suction flow generated at the tip of the end effector (screw turning tool 10 in this embodiment) to the robot main body 2 side (negative pressure generator 24 side). The flow path 19a forming a part of the above is formed. The flow path 19a and the flow path 9a are connected via an air tube 18. One end of the flow path 19a (the end on the tool side) is open to the center of the end face of the fixing member 19.

A screwdriver tool 10 is attached to the hand of the robot body 2 as an end effector. Specifically, the screwdriver tool 10 is fixed to the fixing member 19 and is attached to the tip of the articulated arm of the robot body 2 via the tool-side coupler 9 and the master-side coupler 8.

Hereinafter, the detailed configuration of the screwdriver tool 10 will be described. The screw turning tool 10 mainly includes a shaft body 11 and a suction pad (contact member) 12.

The shaft body 11 is an elongated shaft-shaped member. The shaft body 11 is fixed to the center of the end surface of the fixing member 19 on the side opposite to the side connected to the tool side coupler 9. The shaft body 11 is provided in a state where the output shaft of the electric motor 22 and its axis are aligned with each other. The shaft body 11 rotates integrally with the master side coupler 8, the tool side coupler 9, and the fixing member 19 by the torque applied from the output shaft of the electric motor 22.

The shape of the tip of the shaft body 11 when viewed in the axial direction of the shaft body 11 is a recess formed in the head (screw head) of the target screw 7 to be conveyed and tightened by the screw turning tool 10. It has a shape corresponding to 7a. Specifically, in the present embodiment, the recess 7a is formed as a regular hexagonal hole, and the tip portion of the shaft body 11 is formed in a regular hexagonal columnar shape. In this way, the tip of the shaft body 11 has a shape that matches the screw head of the screw 7 to be conveyed and tightened. Therefore, if the screw 7 and the rotation phase match each other, the screw head It can be fitted in the recess 7a formed in the portion.

As will be described in detail later, the tip portion 11t of the shaft body 11 of the screw turning tool 10 aligns the rotational phase with each other in the recess 7a of the screw head of the screw 7 when the screw 7 is conveyed and tightened. It is inserted in the state of being.

In the present embodiment, the tip portion 11t of the shaft body 11 is formed with a first suction port (suction port) 11a and a second suction port 11b for sucking air from the outside. Specifically, the first suction port 11a of the present embodiment is formed (opened) in a circular shape on the end surface (tip surface) of the tip portion 11t of the shaft body 11. The second suction port 11b of the present embodiment is formed (opened) in a circular shape on the outer peripheral surface of the tip end portion 11t of the shaft body 11 (see FIG. 2). The second suction port 11b is open to the cavity (internal space) of the suction pad 12, which will be described later.

Further, inside the shaft body 11, air sucked from the first suction port 11a and the second suction port 11b is passed toward the negative pressure supply port 8b and eventually toward the negative pressure generator 24. The flow path 11c is formed. The flow path 11c of the present embodiment is formed linearly so as to extend parallel to the axis of the shaft body 11. The first suction port 11a is connected to the one end portion of the flow path 19a via the flow path 11c. The second suction port 11b is connected to the one end portion of the flow path 19a via the branch path 11d and the flow path 11c. The branch path 11d is a linear flow path connecting the second suction port 11b and the middle portion of the flow path 11c.

The suction pad 12 is made of a material such as rubber that can be elastically deformed, and has a shape in which a half portion on the tip side thereof expands in a tapered shape (a shape that expands toward the end). The suction pad 12 is provided in the vicinity of the tip end portion 11t of the shaft body 11 in a state of being penetrated through the shaft body 11. The upper end portion of the suction pad 12 is fixed to the outer peripheral surface of the shaft body 11 while maintaining airtightness so that a gap is not formed between the suction pad 12 and the shaft body 11. The inside of the suction pad 12 is hollow. Axial direction from the edge 12a on the tip side of the suction pad 12 (the edge corresponding to the bottom of the taper) to the tip surface of the shaft body 11 (the end surface on which the first suction port 11a is opened). The distance L1 is arranged so as to substantially match or be shorter than the depth L2 of the recess 7a (hexagonal hole) formed in the screw head of the screw 7 (L1 ≦ L2).

Further, in the present embodiment, in order to realize the miniaturization of the configuration, the outer diameter D1 of the bottom (edge portion 12a) of the above-mentioned taper of the suction pad 12 is the screw 7 (of the screw head) to be conveyed / tightened. It is set to be the same as or smaller than the outer diameter D2 of the top surface (D1 ≦ D2). However, the outer diameter D1 of the suction pad 12 may be larger than the outer diameter D2 of the top surface of the screw head (D1> D2).

In the screw turning tool 10 of the present embodiment, the negative pressure generator is switched between driving and stopping the negative pressure generator 24, and among the flow paths of the suction flow from the suction ports 11a and 11b to the negative pressure generator 24. By switching the opening and closing of the valve 25 provided in the vicinity of the 24, it is possible to switch whether or not the negative pressure is supplied to the negative pressure supply port 8b. By switching whether or not the negative pressure is supplied to the negative pressure supply port 8b, a suction flow can be generated in the first suction port 11a and the second suction port 11b only when necessary. The negative pressure generator 24 is appropriately driven or stopped in response to a command signal from the robot controller 4. Further, the opening and closing of the valve 25 is also appropriately controlled in response to a command signal from the robot controller 4. Specifically, in the present embodiment, the suction flow is generated in the suction ports 11a and 11b only while the negative pressure generator 24 is driven and the valve 25 is open.

Further, in the robot main body 2 of the present embodiment, while the negative pressure generator 24 is stopped and the valve 25 is closed, the compressed air from the compressed air source 31 is supplied to the negative pressure supply port 8b. You can also do it. By switching whether or not the compressed air is supplied to the negative pressure supply port 8b, the compressed air can be blown out from the first suction port 11a and the second suction port 11b only when necessary. Whether or not compressed air is supplied from the compressed air source 31 to the negative pressure supply port 8b is also controlled by appropriately opening and closing the valve 32 (see FIG. 1) in response to a command signal from the robot controller 4. It has become. Specifically, in the present embodiment, compressed air can be supplied to the suction ports 11a and 11b only while the valve 32 is open.

Although not shown, the tip portion (wrist) of the robot body 2 of the present embodiment is provided with an urging member that urges the shaft body 11 of the screw turning tool 10 toward the tip portion side.

Further, in the present embodiment, the suction flow is in the order of the suction port 11a, 11b, the flow path 11c, the flow path 19a, the flow path 9a, the flow path 8a, the negative pressure supply port 8b, the air tube 23, and the negative pressure generator 24. A continuous flow path is formed so as to flow, and a flow meter 26 for detecting the suction flow in the flow path is provided in the middle of the flow path of the suction flow (see FIG. 1). .. The detection result of the flow meter 26 is input to the robot controller 4. Based on the detection result of the flow meter 26, the robot controller 4 determines whether or not the screw 7 is held at the tip of the screw turning tool 10, and appropriately controls the subsequent operation of the robot 1.

Further, in the present embodiment, a pressure sensor 27 for detecting the pressure in the flow path is provided in the middle of the flow path of the suction flow from the suction ports 11a and 11b to the negative pressure generator 24. The detection result of the pressure sensor 27 is input to the robot controller 4. Based on the detection result of the pressure sensor 27, the robot controller 4 determines whether or not the screw 7 is held at the tip of the screw turning tool 10, and appropriately controls the subsequent operation of the robot 1.

In the present embodiment, the master side coupler 8 and the tool side coupler 9 are configured to be detachable from each other, and although not shown, the above-mentioned screw turning tool 10 is attached to the master side coupler 8 (fixing member 19). Instead of the fixed tool-side coupler 9 (via), a tool-side coupler to which another tool is fixed can be attached. The robot body 2 can automatically perform an operation of connecting or disconnecting a desired tool-side coupler (tool-side coupler of the selected 1) to or from the master-side coupler 8 in response to a command signal from the robot controller 4. It has become like. The above-mentioned "other tools" include various known tools such as grippers, welding tools, and deburring tools. Further, a tool for screwing a screw having a size and type different from that of the above-mentioned screw 7 (screw turning tool for a different screw) is also included in the above-mentioned "other tools".

In the following, the series of operations of the robot 1 when the screw 7 is taken out from the pallet 6 by the robot 1 and conveyed and tightened in the screw hole H of the work W will be described in detail with reference to FIGS. 1 to 3. explain. FIG. 3 is a diagram showing a state when the screw 7 is held by the tip portion 11t of the screw turning tool 10.

First, the robot 1 supplies a negative pressure to the negative pressure supply port 8b to generate a suction flow at the suction ports 11a and 11b of the shaft body 11 of the screw turning tool 10, and the torque from the electric motor 22. The tip portion 11t of the shaft body 11 is brought closer to the screw head of the screw 7 to be conveyed / tightened while rotating the shaft body 11 intermittently or continuously (preferably at a low speed). reference). As a result, in a state where the rotation phase of the recess 7a (hexagonal hole in the present embodiment) formed in the head of the screw 7 and the rotation phase of the tip portion 11t of the shaft body 11 are matched, the recess 7a is formed. The tip portion 11t can be inserted.

If the rotational phases do not match each other when the tip portion 11t of the shaft body 11 starts to be inserted into the recess 7a, the tip portion 11t hits the top surface of the head of the screw 7, and the robot 1 screwes the shaft body 11 into the screw 7. The shaft body 11 is relatively pushed back by the reaction force generated when it is pressed against. However, the push-back of the shaft body 11 can be absorbed by the above-mentioned urging member included in the robot 1. As a result, damage to the robot 1 and the screwdriver tool 10 is prevented. Since the shaft body 11 is rotating, the rotation phases of the tip portion 11t and the recess 7a eventually match, and the tip portion 11t is inserted into the recess 7a.

When the end surface of the tip portion 11t of the shaft body 11 and the bottom surface of the recess 7a of the screw 7 are brought into contact with each other, the screw is screwed at a position on the screw head side by a distance L2 (L1) from these contact positions. The top surface of the head of No. 7 and the edge portion 12a of the suction pad 12 come into contact with each other.

In this state, by continuously supplying negative pressure to the negative pressure supply port 8b and continuously generating a suction flow to the suction port 11a of the shaft body 11 of the screw turning tool 10, the bottom surface of the recess 7a of the head of the screw 7 is formed. The suction force causes the shaft body 11 to stick to the end surface of the tip portion 11t, and the bottom surface of the recess 7a of the head of the screw 7 is held on the end face of the tip portion 11t of the shaft body 11 with almost no gap ( To be captured). At the same time, a suction flow also flows in the branch path 11d that branches from the middle of the flow path 11c, and the air in the cavity of the suction pad 12 is sucked into the branch path 11d from the second suction port 11b. As a result, the air in the closed space formed by the suction pad 12 and the top surface of the screw 7 is sucked, the space becomes a negative pressure, and the suction pad 12 is elastically deformed and crushed by the atmospheric pressure. The top surface of the screw 7 and the suction pad 12 are strongly pressed against each other. In this way, the screw 7 is stably held by the tip portion 11t of the screwdriver tool 10.

By operating the articulated arm of the robot body 2 while holding the screw 7 in this way, the screw 7 reaches a position immediately above the screw hole H of the work W (immediately above the position where the tightening work is performed). Be transported. While the screw 7 is being conveyed, the state in which the suction flow is generated in the suction ports 11a and 11b is maintained so that the screw 7 does not fall off from the tip of the screwdriver tool 10. However, if the negative pressure in the closed space is substantially maintained and the screw 7 does not fall off, it is not necessary to generate a suction flow during transportation.

The detection result of the flow meter 26 is confirmed during the transfer of the screw 7 or at an appropriate timing before and after the transfer. Specifically, the robot controller 4 determines whether or not the flow rate of the suction flow in the flow path provided with the flow meter 26 is equal to or less than the threshold value. As a result, when the flow rate of the suction flow in the flow path is equal to or less than the threshold value, it is considered that the hand of the robot 1 normally holds the screw 7 (successfully held), so that the robot controller 4 is an electric motor. The drive of 22 is stopped, and control is performed to move to the next tightening work. On the other hand, when the flow rate of the suction flow exceeds the threshold value, it is considered that the hand of the robot 1 does not hold the screw 7 (failed to hold it) for some reason, so that the robot controller 4 shifts to the next tightening work. For example, control is performed to take out another screw 7 on the pallet 6. The robot controller 4 may determine whether or not the pressure detected by the pressure sensor 27 is equal to or less than the threshold value, instead of determining whether or not the flow rate is equal to or less than the threshold value.

When it is confirmed that the hand of the robot 1 normally holds the screw 7, the screw 7 is lowered (toward the bottom surface of the screw hole H) while being held by the hand of the robot 1. Is done. Then, when the tip portion 11t of the screw 7 reaches the vicinity of the upper end of the screw hole H, the electric motor 22 is driven again. As a result, the shaft body 11 is rotated, and the screw 7 held by the tip portion 11t is screwed into the screw hole H. In other words, in response to the command signal from the robot controller 4, a screwdriver operation for rotating the shaft body 11 is performed, and the screw 7 captured at the tip end portion of the shaft body 11 is screwed into the screw hole H. As a result, for example, the parts constituting the work W are tightened and fixed to each other.

The robot 1 stops the supply of the negative pressure to the negative pressure supply port 8b at an appropriate timing during the tightening work of the screw 7, and stops the suction flow generated in the suction ports 11a and 11b until then. .. As a result, the state in which the screw 7 is held (captured) by the hand of the robot 1 can be released, and the robot 1 can be made to perform the next work. At this time, by opening the valve 25 and supplying the compressed air to the suction ports 11a and 11b, the compressed air is ejected from the suction ports 11a and 11b, and the tip portion 11t is securely inserted from the recess 7a of the head of the screw 7. It can also be made to leave.

As described above, in the robot 1 to which the screw turning tool 10 of the present embodiment is attached, the screw 7 can be continuously conveyed and tightened without replacing the tool attached to the hand on the way. .. Therefore, it is possible to improve the efficiency and speed of work.

Further, by setting the suction flow generated at the suction ports 11a and 11b of the tip portion 11t of the shaft body 11 to an appropriate size (flow velocity), the screw held at the tip portion 11t of the shaft body 11 during transportation. It is possible to surely prevent the 7 from being dropped.

Further, as described above, when the screw 7 is tightened with a gripper as in the conventional case, there is a problem that the screw 7 slips due to insufficient grip force. In this respect, in the present embodiment, since the tip portion 11t of the shaft body 11 is inserted into the recess 7a of the head of the screw 7 and held, such a problem does not occur.

Further, in the screw turning tool 10 of the present embodiment, the screw 7 is not captured by the magnetic force but is captured (adsorbed) by the suction flow, so that the screw 7 is made of a non-magnetic material. It can also handle cases. Therefore, it is highly versatile and can be used in various cases.

Further, in the robot 1 provided with the screw turning tool 10 of the present embodiment, a state in which a suction flow is generated in the suction ports 11a and 11b and a state in which the suction flow is stopped (if necessary, further suction). By switching between the state in which compressed air is ejected from the openings 11a and 11b and), the screw 7 is no longer required without manually removing the screw 7 held at the tip portion 11t of the screw turning tool 10. Sometimes the holding state can be canceled automatically.

Further, in the screw turning tool 10 of the present embodiment, since it is not necessary to arrange the suction pad 12 or the like so as to surround the entire head of the screw 7 (the entire circumference), the screw turning can be performed even in a narrow environment. can. That is, if the tip portion 11t of the screw turning tool 10 is accessed to a small area on the top surface side of the screw 7, the screw 7 can be held, so that the screws 7, 7, ... Are arranged at narrow intervals. The work can be performed even in a narrow place such as when the screw 7 is taken out from the pallet 6. Further, even when the screw 7 taken out from a predetermined place and conveyed to a desired place is screwed into the screw hole H of the work W, the screw turning tool 10 is used for the external environment around the screw hole H (for example, the assembly base or the assembly base). It is less likely to interfere with other assembled workpieces) and can prevent damage to the external environment.

Further, regardless of the rotation phase of the recess (hexagonal hole) 7a of the screw head when the screw 7 is taken out, the tip portion 11t is recessed in a state of being matched with the phase of the tip portion 11t of the shaft body 11. Since the screw 7 can be fitted into the 7a and captured, the work of matching the phase of the screwdriver and the phase of the screw head in a later step becomes unnecessary. Therefore, it is possible to continuously perform the transporting / tightening work of the screw 7 at high speed.

Further, since the screwdriver 10 of the present embodiment has a small number of parts and a simple structure, it has an advantage that it can be manufactured at low cost and is not easily broken.

As described above, the screwdriver tool 10 of the present embodiment is attached to a robot body (main body) 2 including an electric motor (power source) 22 capable of generating torque and a negative pressure supply port 8b. The screw turning tool 10 has a tip portion 11t having a shape corresponding to a recess (hexagonal hole in this embodiment) 7a formed in the screw head of the screw 7, and has a shaft body 11 rotated by the torque. Be prepared. A first suction port (suction port) 11a for sucking air is opened at the tip end portion 11t of the shaft body 11. Inside the shaft body 11, a flow path 11c is formed to allow air sucked from the first suction port 11a to pass toward the negative pressure supply port 8b.

As a result, a suction flow from the first suction port 11a to the negative pressure supply port 8b (see the linear arrows in FIGS. 2 and 3) is generated at the tip of the shaft body 11 to generate a screw head of the screw 7. The screw 7 can be held by the screw turning tool 10 in a state where the tip portion 11t of the shaft body 11 is inserted into the concave portion (hexagonal hole) 7a of the portion. As a result, a series of operations of holding the screw 7, transporting it to a desired place, and screwing it can be performed without changing the tool, and the work speed can be increased. Further, since the first suction port 11a is formed at the tip end portion 11t of the shaft body 11, the air sucked by the first suction port 11a passes through the inside of the shaft body 11 and flows to the negative pressure supply port 8b. , A compact configuration can be realized, and screwing can be easily performed even in a narrow space.

Further, the screwdriver 10 of the present embodiment includes a suction pad (contact member) 12 capable of forming a closed space by contacting the top surface of the screw head of the screw 7.

As a result, the screw 7 can be held without securing a large space around the screw head.

Further, in the screwdriver tool 10 of the present embodiment, the second suction port 11b is configured to be able to suck air in the space formed by the suction pad 12.

As a result, the screw 7 can be reliably held by increasing the suction force due to the negative pressure.

Further, in the screw turning tool 10 of the present embodiment, a second suction port 11b for sucking air is opened on the outer peripheral surface of the shaft body 11, and the air sucked from the second suction port 11b is the shaft body. It passes through the inside of 11 (in this embodiment, the branch path 11d and the flow path 11c) and flows toward the negative pressure supply port 8b.

As a result, the screw 7 can be stably held by suction at a plurality of locations (in this embodiment, suction ports 11a and 11b).

Further, the robot 1 of the present embodiment includes the above-mentioned screw turning tool 10 and the robot main body 2.

This makes it possible to hold, transport, and turn the screw 7 as a series of operations without changing tools.

Further, in the robot 1 of the present embodiment, it is possible to switch whether or not the negative pressure is supplied to the negative pressure supply port 8b.

As a result, when it becomes unnecessary to hold the screw 7, by stopping the supply of negative pressure, the suction at the tip portion 11t of the shaft body 11 is released, and the tip portion 11t of the screw turning tool 10 is released. It can be automatically separated from the screwdriver tool 10.

Further, in the robot 1 of the present embodiment, compressed air can be supplied to the negative pressure supply port.

As a result, the holding of the screw 7 can be forcibly released by ejecting compressed air from the suction ports 11a and 11b.

Further, in the robot 1 of the present embodiment, the pressure detection result in the path from the negative pressure generator (negative pressure source) 24 to the suction ports 11a and 11b (in the present embodiment, the flow path in the air tube 23), Further, a robot controller (control unit) 4 for determining whether or not the screw 7 is held by the tip portion 11t of the screw turning tool 10 is provided based on the detection result of the air flow in the path.

Thereby, it is possible to determine whether or not the screw 7 is held by the tip portion 11t of the screw turning tool 10 with a simple configuration.

Further, in the robot 1 of the present embodiment, when the shaft body 11 is relatively pushed by the top surface of the head of the screw 7, the urging member (not shown) exerts an urging force to push back the shaft body 11. ).

As a result, even if the rotation phases do not match when the shaft body 11 starts to be inserted into the recess 7a and the shaft body 11 comes into contact with the top surface of the head of the screw 7, it is possible to prevent the robot 1 and the like from being damaged. ..

Further, in the robot 1 of the present embodiment, the main body including the electric motor 22 and the negative pressure supply port 8b is configured as the robot main body 2.

As a result, the robot 1 can efficiently hold, transfer, and turn the screw 7.

Further, in the robot 1 of the present embodiment, the robot main body 2 is configured in an arm shape. The screw turning tool 10 is attached to the tip end portion (hand) of the robot body 2.

As a result, by attaching the screwdriver tool 10 to the tip (hand) of the arm-type robot 1 and using it, it is possible to easily perform work in a narrow place.

Further, in the present embodiment, a method of transporting and tightening the screw 7 by using the screw turning tool 10 is disclosed. In this method, the tip portion 11t of the shaft body 11 is brought closer to the screw head of the screw 7 while generating a suction flow at the suction ports 11a and 11b and rotating the shaft body 11, so that the screw head is formed. The screw 7 is held in a state where the tip portion 11t is fitted in the recess (hexagonal hole) 7a formed in the portion. Then, the screw 7 is conveyed to a position where the tightening work is performed. Then, by rotating the shaft body 11 at the position of the transport destination, the screw 7 held at the tip portion 11t is screwed.

As a result, a series of operations of taking out the screw 7 from a predetermined place (pallet 6 in the present embodiment), transporting the screw 7 to another place (a position immediately above the screw hole H in the present embodiment), and screwing the screw are performed. Can be done without replacement. As a result, the speed of screw tightening work can be increased. Further, regardless of the rotation phase of the recess 7a of the screw head when the screw 7 is taken out, the tip portion 11t of the shaft body 11 is brought closer to the recess 7a while simultaneously rotating and sucking the shaft body 11. As a result, the screw 7 can be reliably held in a state where the tip portion 11t of the shaft body 11 is fitted in the recess 7a. This can reduce work failures.

Next, a modification of the above embodiment will be described. FIG. 4 is a diagram showing a modified example of the suction pad mainly provided in the screwdriver tool 10. In the description of this modification, the same reference numerals may be given to the drawings for the same or similar members as those in the above-described embodiment, and the description may be omitted.

In the above embodiment, the suction pad 12 has a shape in which the half portion on the tip side thereof expands in a tapered shape, and is provided at a position slightly distant from the tip portion 11t of the shaft body 11 on the robot body 2 side. However, the shape and arrangement position of the suction pad 12 is not limited to this.

FIG. 4A shows a suction pad 12A according to a modified example of the suction pad 12. The suction pad 12A as a whole has a tapered shape that expands as it approaches the tip portion 11t. The suction pad 12A also creates a suction flow in the suction port 11a to make the internal space of the suction pad 12A a negative pressure, and captures the screw 7 at the tip of the screw turning tool 10 by the differential pressure from the atmospheric pressure. can do.

The suction pad 12B according to another modification of the suction pad 12 is shown in FIG. 4 (b). The suction pad 12B is provided on the end surface of the tip end portion 11t of the shaft body 11 so as to surround the suction port 11a. As a result, the screw 7 can be satisfactorily adsorbed by making it difficult for air to leak from between the tip of the screw turning tool 10 and the bottom surface of the recess 7a of the screw 7. As shown in FIG. 4B, this configuration is also effective for a set screw or the like having no screw head (a screw having a male screw cut over the entire length in the axial direction).

FIG. 4C shows a suction pad 12C according to still another modification of the suction pad 12. The suction pad 12C is provided in the vicinity of the tip portion 11t in a state of being penetrated by the shaft body 11. Also in this suction pad 12C, when the suction pad 12C and the top surface of the screw 7 are brought close to each other and air is sucked from the suction port 11a, a small space between the suction pad 12C and the top surface of the screw 7 is small. The space in the gap becomes a negative pressure and comes into close contact with each other, and the screw 7 is satisfactorily attracted.

Although not shown, in addition to the above-mentioned modification, the suction pad (contact member) is configured to be able to contact the inner wall of the recess 7a of the screw 7, and the suction pad is brought into contact with the inner wall of the recess 7a. This may form a closed space.

Although the preferred embodiments and modifications of the present invention have been described above, the above configuration can be changed as follows, for example.

In the above embodiment, the first suction port 11a for sucking the bottom surface of the concave portion 7a of the head of the screw 7 to the tip end portion 11t of the screw turning tool 10 (shaft body 11), and the closed space inside the suction pad 12. The second suction port 11b for making the pressure negative is individually formed, but the present invention is not limited to this. Instead of the above configuration, for example, assuming that a suction port (corresponding to the second suction port 11b) is not formed on the outer peripheral surface of the shaft body 11, air is sucked from the first suction port 11a. The bottom surface of the recess 7a of the screw 7 may be attracted to the tip portion 11t of the shaft body 11 and the closed space inside the suction pad 12 may be made a negative pressure. In other words, the first suction port 11a may also serve as the second suction port 11b, and the second suction port 11b may be omitted. Alternatively, the second suction port 11b may also serve as the first suction port 11a, and the first suction port 11a may be omitted.

However, since it is not essential for the present invention to have the suction pad 12 and to have a plurality of suction ports formed at the tip of the shaft body 11, the suction pad 12 is omitted. The configuration for creating a negative pressure in the closed space inside the suction pad 12 (corresponding to the second suction port 11b) may also be omitted.

In the above embodiment, the flow path 11c formed in the shaft body 11 for passing the air sucked from the first suction port 11a toward the negative pressure supply port 8b is parallel to the axis of the shaft body 11. ing. However, the flow path 11c does not have to have a portion parallel to the axis. For example, it is conceivable to arrange the flow path 11c diagonally with respect to the axis of the shaft body 11.

In the above embodiment, the robot 1 is provided with both the flow meter 26 and the pressure sensor 27, but either of them may be omitted.

In the above embodiment, the electric motor 22 is provided separately from the motor provided on the shaft of the robot 1. However, instead of the electric motor 22, torque may be applied to the screwdriver tool 10 by a motor provided in the joint 21 of the robot 1.

In the above embodiment, the power source capable of generating the torque applied to the screwdriver tool 10 is assumed to be the electric motor 22, but the power source is not necessarily limited to this, and for example, instead of this, it is driven by air pressure. It may be a motor.

In the above embodiment, the negative pressure source that supplies the negative pressure to the negative pressure supply port 8b is configured by a vacuum ejector that converts the flow of compressed air into a negative pressure, but the present invention is not limited to this. For example, instead of this, the negative pressure source may be configured by a blower device or the like.

In the above embodiment, the recess 7a formed in the screw head of the screw 7 is a hexagonal hole, but the shape does not have to be a hexagonal prism shape, and any known screw head shape is adopted. Can be. Specifically, for example, the recess of the screw 7 to be transported / tightened may be a quadrangular prism-shaped recess. Furthermore, the concave portion of the screw 7 is not necessarily concave-shaped, and may be groove-shaped instead. Specifically, for example, the recess of the screw 7 may be a plus-shaped groove or a minus-shaped groove. In that case, it is conceivable that a sufficient space for forming an opening corresponding to the first suction port 11a cannot be secured at the tip of the groove. However, even in such a case, for example, a configuration corresponding to the suction pad 12 and a configuration for making the closed space inside the suction pad 12 a negative pressure (corresponding to the second suction port 11b) are provided. If it is provided on the outer peripheral surface in the vicinity of the tip portion (groove), the screw 7 can be conveyed and tightened in the same manner as in the above embodiment.

In the above embodiment, the screw 7 having a screw head is disclosed as a screw to be conveyed and tightened, but the present invention is not limited to this, and a set screw or the like having no screw head as shown in FIG. 4 (b) is used. (Screws with male threads cut over the entire length in the axial direction) can also be used as screws to be transported and tightened. Since the screwdriver tool 10 of the present invention can hold the screw without securing a large space around the top of the screw, even for a screw such as a set screw, until the entire length is embedded in the screw hole (last). Up to) It is possible to tighten the screws.

In the above embodiment, the screwdriver tool 10 is attached to the hand of the robot main body 2, but the present invention is not limited to this, and for example, instead of this, the main body (tool main body) of a power tool carried by a human can be used. It may be attached as a detachable tool. In this case, by attaching the screwdriver tool 10 to the tool body, the power tool functions as a screwdriver.

In the above embodiment, the method of transporting the screw 7 by the robot 1 to which the screw turning tool 10 is attached and tightening the screw 7 at the transport destination is disclosed. Even if it is possible to rotate the attached screw in the direction opposite to the tightening direction to remove it from the work W, and to transport the removed screw 7 to a predetermined place (for example, a collection box). good.

In the above embodiment, the screw turning tool 10 is brought closer from above to capture the screw head of the screw 7 arranged in the vertical direction at the tip portion 11t, but the present invention is not limited to this, for example. Instead of, the screw turning tool 10 may be brought closer from the side, and the screw head of the screw arranged sideways may be captured by the tip portion 11t. Similarly, the moving direction of the screw 7 when tightening the screw 7 using the screw turning tool 10 is not limited to the downward direction, and may be, for example, the horizontal direction.

In the above embodiment, the robot main body 2 has a configuration including one articulated arm, but the robot main body to which the screwdriver tool 10 is attached is limited to one having only one articulated arm. Instead, for example, two articulated arms may be provided in pairs. Further, the number of joints may be singular. For example, even if the robot body has an arm that rotates only in the horizontal direction, the screw turning tool 10 can be attached and used for transporting and tightening the screw 7.

1 Robot 2 Robot body (main body)
7 Screw 7a Recess 8b Negative pressure supply port 10 Screw turning tool 11 Shaft body 11a First suction port (suction port)
11c Flow path 11t Tip 22 Electric motor (power source)

Claims (9)

A main body equipped with a power source capable of generating torque and a negative pressure supply port ,
With the screwdriver tool attached to the main body ,
It is a screwdriver equipped with
The screwdriver is
A shaft body having a tip portion having a shape corresponding to a concave portion formed in the screw head of the screw and rotating by the torque, and a shaft body having a shape corresponding to the concave portion.
A contact member capable of forming a closed space by contacting the top surface of the screw head,
Equipped with
A suction port for sucking air is opened at the tip of the shaft body.
The suction port is configured to be able to suck air in the space formed by the contact member.
Inside the shaft body, a flow path is formed to allow air sucked from the suction port to pass toward the negative pressure supply port .
The contact member is penetrated through the shaft body and is fixed to the outer peripheral surface of the shaft body while maintaining airtightness.
In the shaft body, the tip portion side and the side far from the tip portion of the contact member are exposed to the outside.
It is provided with an urging member that exerts an urging force that pushes back the shaft body when the shaft body is relatively pushed by the screw head.
A screwdriver which is characterized in that when the shaft body is relatively pushed in, the contact member is also pushed in integrally with the shaft body . The screw turning device according to claim 1 .
A second suction port for sucking air is opened on the outer peripheral surface of the shaft body.
A screwdriver, characterized in that air sucked from the second suction port passes through the inside of the shaft body and flows toward the negative pressure supply port. The screwdriver according to claim 1 or 2 .
A screwdriver that can switch between the presence and absence of negative pressure supply to the negative pressure supply port. The screwdriver according to claim 3 , wherein the screw turning device is used.
A screwdriver, characterized in that compressed air can be supplied to the negative pressure supply port. The screwdriver according to any one of claims 1 to 4 .
Based on the pressure detection result in the path from the negative pressure source to the suction port or the air flow detection result in the path, it is determined whether or not the screw is held at the tip of the screw turning tool. A screwdriver, characterized in that it is provided with a control unit. The screwdriver according to any one of claims 1 to 5 .
A screwdriver whose main body is a robot main body. The screw turning device according to claim 6 .
The robot body is configured in an arm shape.
The screw turning tool is a screw turning device, characterized in that the screw turning tool is attached to a tip end portion of the robot body. The screwdriver according to any one of claims 1 to 5 .
A screwdriver whose main body is a tool main body of a tool held by a human being. A method of transporting and tightening a screw using the screwdriver according to claim 1 .
By bringing the tip of the shaft body closer to the screw head of the screw while generating a suction flow at the suction port and rotating the shaft body, the recess formed in the screw head is formed. Hold the screw with the tip fitted,
Transport the screw to the position where tightening work is performed,
A method characterized by screwing the screw held at the tip end portion by rotating the shaft body at a position of a transport destination.

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