JP2011131330A - Screw fastening machine - Google Patents

Abstract

Provided is a screw tightening machine that automatically starts driving a driver tool when the position information of a driver tool matches the position information of a target screw tightening point.
The present invention relates to a screw tightening machine configured such that an operator grips a driver tool and operates the driver tool above the object to be fastened, and lowers it to a target screw tightening point to perform a screw tightening operation. The position detection means 14, 23, 34 for detecting the position information of the driver tool 4 and the position information of the target screw fastening point are stored in advance, and the screw is being operated while the driver tool 4 is being operated over the object to be fastened. A control unit 50 configured to issue a drive start command signal to the driver tool when the position information of the tightening point and the driver tool 4 is collated and the collation is matched.
[Selection] Figure 6

Description

  The present invention relates to a screw tightening machine for an operator to hold and operate a driver tool attached to an arm and perform a screw tightening operation.

  2. Description of the Related Art Conventionally, as a screw tightening machine that performs a screw tightening operation by an operator holding a driver tool attached to an arm and operating it to a desired position, one disclosed in Japanese Patent Laid-Open No. 7-1347 is disclosed. It has been known. In this screw tightening machine, the arm is configured to be freely movable in the horizontal and vertical directions. With this configuration, the operator grips the driver tool attached to the balance arm and operates it in the horizontal direction, and visually matches the screw held at the tip of the driver tool with the target screw tightening point. Let Then, the operator manually operates the start switch of the driver tool to drive the driver tool, and the screw is tightened to a target screw tightening point.

JP-A-7-1347

  However, in the above screw tightening machine, the driver tool must be manually operated and driven by the operator, so that there is a problem that the burden on the operator increases.

  The present invention was created in view of the above problems, and a screw tightening machine that automatically starts driving a driver tool when the position information of the driver tool matches the position information of the target screw tightening point. The purpose is to provide.

  In order to achieve the above-mentioned object, the screw tightening machine of the present invention has a balance arm movable in the horizontal and vertical directions, and a driver bit attached to the balance arm and rotated by driving of a drive source at the tip. A screw tightening machine comprising: a driver tool, wherein the driver grips the driver tool and operates it over the object to be fastened, and lowers it to a target screw tightening point to perform the screw tightening operation. The position detection means for detecting the position information of the tool and the position information of the target screw tightening point are stored in advance, and the position information of the screw tightening point and the driver tool is obtained while the driver tool is operated over the object to be fastened. A control unit configured to issue a drive start command signal to the driver tool when the verification results in a match. Screw driver according to claim Rukoto.

  According to the screw tightening machine of the present invention, when the position information of the target screw tightening point matches the position information of the driver tool, the driver tool is configured to automatically start driving. This reduces the burden on the operator, eliminates the need for a manual start mechanism mounted on the driver tool, and provides a screw tightening machine that is inexpensive in terms of cost.

It is a whole block diagram in the screwing machine of this invention. It is a plane view enlarged sectional view which shows the raising / lowering movable mechanism in the screwing machine of this invention. It is a front view expanded sectional view which shows the raising / lowering movable mechanism in the screwing machine of this invention. It is a partially cutaway expanded sectional view which shows the turning movable mechanism in the screwing machine of this invention. It is a partially notched expanded sectional view which shows the horizontal movable mechanism in the screwing machine of this invention. It is explanatory drawing which shows the image of the collation determination by the control unit in the screwing machine of this invention. The struts and arms are shown schematically. It is an external view of the control unit in the screwing machine of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a screw tightening machine, which moves up and down along a support column 2 erected in the vertical direction, and an arm 3 that moves on a horizontal plane, and a driver tool that is attached to the arm 3 and moves integrally therewith. 4 is provided. The driver tool 4 is attached to the tip of the arm 3, and the bracket 5 is attached to the rear end of the arm 3 so that it can be moved up and down along the support column 2 and can pivot together with the support column 2.

  The arm 3 is configured to be movable up and down along the support column 2 by an elevating movable mechanism 10 shown in FIGS. 2 and 3. The elevating movable mechanism 10 includes a pulley 11 that is pivotally supported above the column 2, a belt 12 that is wound around the pulley 11 so as to cover the column 2, and a weight 13 that is attached to one end of the belt 12. It is composed of Then, the bracket 5 is attached to the other end of the belt 12, and when the operator grips the grip 4a of the driver tool 4 and operates the arm 3 in the vertical direction, due to the action of gravity on the weight 13, The arm 3 is configured to move up and down along the column. And the rotary encoder 14 which is an example of a position detection means detects the rotation amount of the pulley 11. FIG. Thereby, it is comprised so that the raising / lowering position information of the arm 3 may be detected. That is, as shown in FIG. 6, the rotary encoder 14 detects the Z-axis coordinate of the driver tool 4 in the spatial coordinates where the vertical direction is the Z-axis, the horizontal turning direction is the X-axis, and the horizontal direction is the Y-axis. It is configured.

  Further, the arm 3 is configured to freely swivel and move along a horizontal plane integrally with the support column 2 by a swivel movable mechanism 20 shown in FIG. The swivel movable mechanism 20 meshes with the first spur gear 21 that is rotatably attached to the lower end of the support 2 and the first spur gear 21, and is used to rotate the first spur gear 21. The second spur gear 22 rotates with the rotation. Thereby, the support | pillar 2 turns with the turning of the arm 3, the 1st spur gear 21 also rotates, and the 2nd spur gear 22 also rotates with this. The rotary encoder 23 detects the amount of rotation of the second spur gear 22 and detects the turning position information of the arm 3 in the horizontal plane. That is, in the spatial coordinates shown in FIG. 6, the rotary encoder 23 is configured to detect the X-axis coordinates of the driver tool 4.

  Further, the arm 3 is configured to be freely movable in a direction (horizontal direction) orthogonal to the X axis and the support column 2 by a horizontal movable mechanism 30 shown in FIG. The horizontal movable mechanism 30 includes a rail 31 and a guide block 32 that guides the movement of the rail 31, and the arm 3 is attached to the tip of the rail 31. A gear 33 is pivotally supported in the vicinity of the rear of the rail 31, and an outer tooth 31 a that can mesh with the gear 33 is formed at the rear end of the rail 31. As a result, when the operator operates the arm 2 to move it horizontally, the gear 33 rotates. Then, the rotary encoder 34 detects the amount of rotation of the gear 33 and detects horizontal movable position information of the arm 3 that moves horizontally. That is, the rotary encoder 34 is configured to detect the Y-axis coordinates of the driver tool 4 in the spatial coordinates shown in FIG.

  The driver tool 4 includes a motor 4b as a drive source at an upper portion thereof, and the rotational drive of the motor 4b is configured to be transmitted to a driver bit 4c at the tip via a driver shaft (not shown). The driver tool 4 is connected to the control unit 50 via the driver controller 40, and the driver controller 40 automatically controls the drive stop and drive start of the motor 4b according to the drive command from the control unit 50. It is configured as follows.

  Further, the driver bit 4c is configured such that its tip can be engaged with a drive hole in the screw head, and a ring-shaped magnet 4d is attached to the driver bit 4c. As a result, the driver bit 4c is magnetized, and the screw can be electromagnetically attracted.

  Information detected by the rotary encoders 14, 23, 34 is transmitted to the control unit 50 via the encoder cables 14a, 23a, 34a. Thereby, the position information of the driver tool 4 in the space coordinates is detected.

  The control unit 50 is configured to store, as a teaching program, position information of one or a plurality of screw fastening points on an object to be fastened in a built-in storage unit (not shown). The position information (X, Y coordinates) of the screw tightening point and the position information (X, Y coordinates) of the driver tool 4 are collated and determined (matching determination function). The (X, Y coordinates) data is collated to determine whether or not they match. As shown in FIG. 7, this collation result (coincidence / non-coincidence) is configured to be displayed on an OK lamp 52 or an NG lamp 53 attached near the monitor 51 of the control unit 50. In this case, the OK lamp 52 is turned on, and in the case of mismatch, the NG lamp 53 is turned on to visually notify the operator of the collation result. Moreover, different sounds flow from the speaker 54 according to the collation result, and the collation result is also audibly notified to the operator. Further, at the time of collation coincidence, a drive start command signal is issued to the driver tool 4 so that the driver tool 4 automatically starts driving. Here, when the collation temporarily does not coincide after the collation coincidence, a drive stop command signal is issued to the driver tool 4, and the drive is stopped.

  By the way, in the collation judgment by the control unit 50, as shown in FIG. Due to this collation determination reference area, the control unit 50 does not match the position information (X, Y coordinates) of the screw tightening point and the position information (X, Y coordinates) of the driver tool 4 without any deviation. Also, if the driver tool is located in the area, it is determined as a match. Specifically, a rectangular horizontal plane area centered on an arbitrary point on the Z-axis line (vertical line) passing through the screw tightening point A is stored as the collation determination reference area. In addition, the size of the collation determination reference area differs depending on the lift position (Z-axis coordinates) of the driver tool 4, and the lower collation determination reference area B is set narrower than the upper collation determination reference area A. . That is, in the spatial coordinates, the collation determination reference area forms an inverted quadrangular pyramid and is set to be gradually narrowed.

  Further, in the collation determination based on the collation determination reference area, when the driver tool 4 is located in the area, a drive start command signal is issued from the control unit 50 to the driver tool 4 via the driver controller 40. On the other hand, when the driver tool 4 is out of the area, a drive stop command signal is issued to the driver tool 4 and the drive is controlled to stop.

  Further, the control unit 50 is set with a Z-axis coordinate as a reference for starting the driving of the driver tool 4. Specifically, even when the collation matches in the collation determination based on the collation reference area, when the driver tool 4 is located at a position higher than the drive start reference value in the Z-axis coordinates, a drive start command No signal is generated and the driver tool 4 is controlled not to be driven. When the collation determination is coincident at a position lower than the drive start reference value in the Z-axis coordinate, a drive command signal is issued to the driver tool 4 and control is automatically started. .

  In addition, the rotational load torque value of the driver tool 4 is configured to be transmitted to the control unit 50 during the fastening operation. In addition, the control unit 50 is set with a torque value serving as a reference for completion of fastening, and when the rotational load torque of the driver tool 4 reaches the reference value, the control unit 50 passes the driver tool 4 via the driver controller 40. A drive stop command signal is issued to complete the screw tightening operation.

  Here, the control unit 50 has four modes as an operation mode: an order mode, a random mode, a free mode and a collation determination invalid mode, and operates the touch panel type monitor 51 of the control unit shown in FIG. Is configured to be selectable as required.

  In the order mode, the screw tightening operation is performed in the order determined for the plurality of screw tightening points. Therefore, in addition to the position information of the screw tightening points, the control unit 50 stores the tightening order as a teaching program. Further, the position information of the screw tightening points where the screw tightening is completed is also stored in order. Furthermore, the collation determination reference area at the target screw tightening point is read, and collation determination is performed based on the collation determination area. Therefore, for example, when the target screw tightening point is A, when the operator erroneously tries to tighten the screw to the screw tightening point B and the driver tool 4 deviates from the collation determination reference area at the screw tightening point A, this is detected. The NG lamp 53 is turned on and a warning sound is emitted from the speaker 54. Accordingly, when the operator lowers the driver tool 4 while finely adjusting the horizontal position of the driver tool 4 to match the collation, the screw can be finally tightened to the screw tightening point A.

  In the random mode, a screw tightening operation is performed at a plurality of screw tightening points without fixing the screw tightening order. However, it has a function to prevent screw tightening to the overlapping point. Therefore, the control unit 50 is configured to store the position information of the screw tightening points as a teaching program and also sequentially store the position information of the points at which the screw tightening is completed. Therefore, as shown in FIG. 6, when the operator is trying to tighten the screw to the screw tightening point A, even if the screw tightening point is switched to B, the screw tightening point is not the point where the screw tightening has already been completed. The lighting of the NG lamp and a warning sound are not generated, and the operation can be continued. At this time, the control unit 50 performs a process of recognizing the next target screw tightening point as B, and the matching determination reference area C of the screw tightening point B corresponding to the Z-axis coordinate of the driver tool 4 is called. Based on this, the collation determination is performed, and finally the screw can be tightened to the screw tightening point B.

  In the free mode, it is possible to perform screw tightening operations to a plurality of screw tightening points without fixing the screw tightening order, and to perform screw tightening to overlapping points. Therefore, the position information of the screw tightening points is stored in advance in the control unit 50 as a teaching program.

  The order mode, random mode, and free mode all have a collation determination function, whereas the collation determination invalid mode does not have a collation determination function. Thus, the operator can perform screw tightening at an arbitrary screw tightening point, and no special operation is required for retightening the screw.

  In the screw tightening work using the screw tightening machine, the operator roughly moves the driver tool horizontally above the target screw tightening point before the collation work. Then, the collating operation is performed with reference to the collation result by the OK lamp 52, the NG lamp 53, or the speaker 54. Here, in the position where the dry tool 4 is positioned upward and the distance between the driver tool 4 and the screw tightening point is long and the matching of the matching visually is relatively difficult, the matching judgment reference area is set wide. On the other hand, in the position where the driver tool 4 is located near the screw tightening point and the matching of the matching by visual observation is relatively easy, the matching confirmation area is set narrow. With this setting, the operator lowers the driver tool 4 while finely adjusting the horizontal position of the driver tool 4 according to the collation result by the OK lamp 52, the NG lamp 53, or the speaker 54 to match the collation. Then, it becomes possible to easily guide the driver tool 4 to the target screw tightening point and tighten the screw.

  In the screw tightening machine 1 of the present invention, the verification determination reference area may be set to a different area for each screw tightening point according to the distance between the screw tightening points. For example, when the distance between the screw tightening points is relatively long, the collation determination reference area is set wide. Thereby, the reference | standard which determines with a match in collation determination does not become careless carelessly, and the collation work by an operator becomes easier.

DESCRIPTION OF SYMBOLS 1 Screw fastening machine 2 Support | pillar 3 Arm 4 Driver tool 4a Grip 4b Motor 4c Driver bit 4d Magnet 5 Bracket 10 Lifting movable mechanism 11 Pulley 12 Belt 13 Weight 14 Rotary encoder 14a Encoder cable 20 Turning movable mechanism 21 1st spur gear 22 1st Two spur gears 23 Rotary encoder 23a Encoder cable 30 Horizontal movable mechanism 31 Rail 31a External teeth 32 Guide block 33 Gear 34 Rotary encoder 34a Encoder cable 40 Driver controller 50 Control unit 51 Monitor 52 OK lamp 53 NG lamp 54 Speaker

Claims (1)

A balance arm that is movable in the horizontal and vertical directions, and a driver tool that is attached to the balance arm and has a driver bit that is rotated by the drive of a drive source at the tip. In a screw tightening machine configured to operate in the sky and lower the target screw tightening point to perform screw tightening work,
Position detecting means for detecting position information of the driver tool;
When the position information of the target screw tightening point is stored in advance and the driver tool is operated over the object to be fastened, the position information of the screw tightening point and the driver tool is collated and the collation is matched. And a control unit configured to issue a drive start command signal.

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