KR100652542B1 - Device for noticing screw tightening - Google Patents

Abstract

The present invention relates to a screw tightening prevention device that eliminates the forgotten or wrong attachment of the part to be fastened in the assembly operation using the electric screwdriver,

When the data is initially set and the work is set, the device 1 (screw fastening prevention device) supplies power to the electric drive (00-1), and monitors the rotation signal and the torque up signal from the corresponding driver and If the set screw score and the used screw score match, the OK signal is output. Accordingly, the device 2 of the next stage becomes operable and operates in the same manner as the device 1, and thus the final stage Unit (n) outputs an OK signal, and when the workpiece is released, the whole tightening is completed, and since the device on the rear side does not operate unless the screw on the front end is smoothly completed, It is impossible to proceed, and the screw tightening prevention device is characterized by being usable as a single body.

Electric driver, work piece, screw tightening prevention device

Description

Screw tightening prevention device {DEVICE FOR NOTICING SCREW TIGHTENING}

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the signal input-output in the screw tightening forget prevention apparatus which concerns on this invention.

Figure 2 is a block diagram showing the configuration of a screw tightening prevention device according to the present invention.

3 is a part of a flowchart for explaining the operation of the screw tightening prevention device according to the present invention.

4 is a part of a flowchart for explaining the operation of the screw tightening prevention device according to the present invention.

Fig. 5 is a part of a flowchart for explaining the operation of the screw tightening forgetting apparatus according to the present invention, and is a flowchart showing processing executed following the flowcharts of Figs. 3 and 4;

6 is an explanatory diagram showing an embodiment in the case where a plurality of screw tightening forgetting devices according to the present invention are cascaded as a unit.

※ Explanation of symbols for main parts of drawing

10: CPU 20: operation input unit

30: display unit 40: signal input and output unit

50: memory 60: power supply

100: screw tightening prevention device 200: electric screwdriver

In addition, an electronic switch means such as a photoMOS relay or a mechanical relay may be used instead of the photo coupler FC installed in each device.

The present invention relates to a screw tightening prevention device, and more particularly, to a screw tightening prevention device for preventing the screw tightening forget when screwing the part to the workpiece by the electric screwdriver in the product assembly work, etc. will be.

In assembling the product, it is necessary to fix the component to the base material or to attach the cover to the case. In order to perform such a member coupling, there is a process of tightening the screw by an electric screwdriver. In the case of tightening with screws, there is a possibility of forgetting the screw or inadequate screwing due to the carelessness of the operator.

An apparatus for preventing such screwing forgetting or fastening failure is described in the following patent documents. In the conventional screw tightening prevention device, a tightening point (number of teeth) is set in advance, and a tightening completion signal is generated when the screw is tightened in conjunction with the operation of the power driver on the electric driver side, which is a tightening tool. . The operator is configured to notify the operator of the completion of the fastening operation or the forgetting of the fastening by whether the fastening score obtained by detecting and counting the generated fastening completion signal coincides with the set score.

[Patent Document 1] Japanese Patent Laid-Open No. 2000-47705

[Patent Document 2] Japanese Patent Application Laid-Open No. 7-80128

[Patent Document 3] Japanese Patent Laid-Open No. 2003-123050

By the way, as a result of assembly errors caused by workers during fastening, screw fastening and screw fastening failure are also relatively high. In addition, even if the screw is securely fastened, the part to be fastened may be wrong or the screw may be fastened to the base material in the absence of the fastened material. In the conventional screw tightening forgetting device, one screw tightening forgetting device is generally connected to one electric screwdriver. On the other hand, in the one-person production method recently seen in cell production or stand production, one worker often assembles a single product to a finished product using a plurality of electric drivers. Therefore, in a one-person production method using a plurality of electric drivers, a plurality of screw tightening prevention device is required.

In the one-man production method, it is necessary to connect a plurality of electric screwdrivers and a plurality of screw tightening prevention devices in a one-to-one manner and set a score or the like on each screw tightening prevention device. It is necessary to smoothly perform the assembly work in order by clearly indicating the order and the electric driver to be used. For this reason, it is necessary to install a sequence control part (programmable controller) externally so that an operator can perform a work in order, and to prevent the operator's miss during assembly work.

However, the introduction of the sequence control apparatus is expensive to purchase and at the same time requires a process and cost such as connecting the sequence controller and a plurality of screw tightening prevention devices with signal lines or designing a program of the sequence controller. . This relatively large initial cost is a major obstacle to the introduction of sequence control devices in small production plants.

In addition, in production methods such as small quantity batch production, cell production, and stand production, the assembly order and the assembly process are frequently changed according to the product to be assembled, and it is a great effort to change the setting of the sequence control device every time. In need.

In addition, Japanese Patent Application Laid-Open No. 2000-47705 discloses a device in which a plurality of electric drivers can be connected to a single screw tightening prevention device. In this device, the number of connection of the electric driver is fixed. Therefore, there is a case where the required number of electric drivers is not satisfied, and on the other hand, it becomes more than the required number and surplus occurs, which is uneconomical.

This invention is made | formed in view of the problem of the said prior art example.

The object of the present invention is to use a motorized screwdriver to assemble the product by assembling the screw to eliminate the forgetting or wrong attachment of the parts to be attached to the base material, and to perform the assembly work reliably, while controlling external sequence Inexpensive screw fastening that enables operators to carry out assembly work in order without using a device, and that can flexibly and reliably cope with changes in the type and number of motorized drivers due to sequence changes and process changes. It is to provide an anti- forgetting device.

In order to achieve the above object of the present invention, the present invention (first invention) in the device for preventing the screwing forget when screwing the parts to the workpiece,

First setting means for setting one or a plurality of parts to be attached to the work;

Second setting means for setting a number of points of screw tightening necessary when attaching parts to the workpiece;

First calculating means for calculating a residual score of screw tightening by detecting a signal generated each time the screw is tightened;

First determining means for determining which part is actually taken out by detecting a signal generated each time the part is actually taken out,

When it is determined whether all the parts set by the first setting means have been taken out, and also the remaining score of the screw tightening obtained by the first calculating means is judged, and all the parts are taken out and it is determined that the remaining score of the screw tightening is zero. And a second judging means for outputting a completion signal indicating completion of the screwing operation.

In the screw tightening forgetting device according to the first aspect of the present invention, the parts and the screw tightening points are set by the third determining means for determining whether or not the workpiece is disposed at the work position, and the first and second setting means. It is also preferable to further include means for outputting a control signal for turning on the power of the electric driver when it is determined by the third judging means that the work is arranged at the work position.

Preferably, the second judging means includes means for outputting a control signal for turning off the power of the electric driver when all parts are taken out and the remaining number of screw tightening is determined to be zero.

In order to achieve the above object, the present invention (second invention) is a device for preventing the screwing forgetting when screwing parts to the workpiece,

First setting means for setting a score of one or a plurality of parts to be attached to the work,

Second setting means for setting a number of points of screw tightening necessary when attaching parts to the workpiece;

First calculation means for calculating a residual score of the part by detecting a signal generated each time the part is actually taken out,

Second calculating means for calculating the remaining score of screw tightening by detecting a signal generated each time the screw is tightened;

A first judgment means for monitoring the remaining score of the parts and the remaining score of the screw tightening obtained by the first and second calculation means, and outputting a completion signal indicating completion of the screwing operation when they are determined to be zero together. It provides a screw tightening prevention device characterized in that.

A screw tightening forgetting apparatus according to a second aspect of the present invention includes a second determining means for determining whether or not a workpiece is arranged at a work position, and the number of parts and a screw tightening score are set by the first and second setting means. In addition, it is preferable to further include means for outputting a control signal for turning on the power of the electric driver when it is determined by the second judging means that the workpiece is arranged at the work position. Further, it is preferable that the first judging means further includes means for outputting a control signal for turning off the power of the electric driver when both of the parts remaining score and the screw tightening remaining score are determined to be zero together.

In order to achieve the above object, the present invention (third invention) is also a device for preventing screwing forgetting when screwing a part into a work, and can be used by a single body and a plurality of subordinate connections. In the tightening prevention device,

First setting means for setting a score of screw tightening necessary for attaching the part to the workpiece,

First calculating means for calculating a residual score of screw tightening by detecting a signal generated each time the screw is tightened;

First judgment means for monitoring the remaining score of the screw tightening obtained by the first calculation means, and outputting a completion signal indicating completion of the screwing operation when determining that the remaining score is zero;

When a plurality of screw tightening prevention device is used in cascade connection, the screw tightening forget, characterized in that the at least the first calculation means is not operated unless the completion signal is output from the screw tightening forget prevention device of the front end Provide prevention device.                         

In the screw tightening forgetting apparatus according to the third aspect of the present invention, the apparatus outputs a control signal for turning off the power of the electric driver used when the first determining means determines that the screw tightening remaining point is zero. It is preferable to further provide a power supply OFF signal output means. In addition, the screw tightening prevention device includes a second setting means for setting one or a plurality of parts to be attached to the work, and a device for determining which part is actually taken out by detecting a signal generated each time the part is actually taken out. Further comprising two judging means, wherein the first judging means judges whether all the parts set by the second setting means have been taken out, and also determines the remaining score of the screw tightening obtained by the first calculating means, and the parts are all It is preferable that it is configured to output a completion signal indicating completion of the screwing operation when it is taken out and the remaining number of screw tightening is zero. At this time, the power OFF signal output means is configured such that the first judging means outputs a control signal for turning off the power of the electric driver when all parts are removed and the remaining number of screw tightening is determined to be zero. It is preferable.

The screw tightening prevention device according to the third aspect of the present invention detects a signal generated every time the part is actually taken out and the third setting means for setting the score of one or a plurality of parts to which the part is to be attached to the workpiece. Thereby further comprising second calculating means for calculating the remaining score of the parts, wherein the first judging means monitors the remaining score of the screw tightening and the remaining score of the parts obtained by the first and second calculating means, together with zero It is most suitable to be configured to output a completion signal indicative of the completion of the screwing operation in the case of the determination as In this case, the power OFF signal output means is configured to output a control signal for turning off the power of the used electric driver when the first judging means determines that both the screw tightening remaining score and the component remaining score are both zero. It is desirable to have.

A screw tightening forgetting apparatus according to a third aspect of the present invention includes third determining means for determining whether a work is arranged at a work position, and a score of screw tightening is set by the first setting means. Further, when it is determined by the third judging means that the work is arranged at the work position, it is preferable to further include a power supply ON signal output means for outputting a control signal for turning on the power supply of the electric driver to be used. . When the screw tightening prevention device is provided with the second setting means and the third determining means, the screw tightening score and the parts are set by the first and the second setting means, and the third determining means is used. It is most suitable to further include a first power ON signal output means for outputting a control signal for turning on the power of the electric driver when it is determined that the work is arranged at the work position. When the screw tightening prevention device is provided with the third setting means, the screw tightening point and the part number are set by the first and third setting means, and the work is performed by the third determining means. In the case where it is determined that it is disposed at the position, it is preferable to further include second power source ON signal output means for outputting a control signal for turning on the power source of the electric driver to be used.

The screw tightening prevention device which concerns on 3rd this invention, and the screw tightening prevention device which has the 3rd determination means is a case where it becomes the first stage by using plural cascade connection of a screw tightening prevention device. In the case where it is determined by the third judging means that the work is arranged at the work position, it is preferable to have means for causing the at least first calculation means thereof to operate.

In the screw tightening prevention device according to the third aspect of the present invention, in the case where a plurality of screw tightening prevention devices are used in cascade connection, all the tightening operations for all the screw tightening prevention devices are completed. It is preferable to have a means for outputting a signal and a means for turning off the completion signal outputted by the device only when the screwing prevention device of the last stage outputs the entire fastening completion signal. In this case, in the screw tightening forgetting device provided with the third determining means, when the screw tightening forgetting device is used alone, when it is determined by the third determining means that the workpiece is arranged at the working position, (1) Means for enabling the calculation means to operate, and means for receiving the entire tightening completion signal, and a total tightening which always generates the same output as when the total tightening complete signal is received when the screw tightening prevention device is used alone. And a judging means for judging the output of the entire fastening completion signal receiving means after the completion of the completion signal reception means and the anti-tightening device for outputting the completion signal, and for determining whether the entire fastening completion signal has been input or not. It is preferable. At this time, the entire fastening completion signal receiving means becomes non-conducting only when receiving the entire fastening completion signal when a plurality of screw tightening prevention devices are cascaded. It is preferable that it is a coupler.

1 is an explanatory view showing the input-output relationship of the screw tightening forget prevention device 100 of the present invention. As shown in the figure, the input / output signals of the screw tightening prevention device 100 are as follows.

Input signal

WORK signal from the work detection sensor indicating whether or not the work is set (and as described later, when a plurality of screw tightening prevention devices are cascaded, the screw tightening prevention devices other than the first stage may be replaced with the WORK signal. OK signal from the screw tightening prevention device of the previous stage is input.)

PART (A), PART (B) signal and PART (C) signal indicating ejection of parts (A), (B) and (C) from the part ejection detection sensor, respectively.

ㆍ Rotation signal indicating rotation from electric driver 200

ㆍ TORQUE＿UP signal indicating completion state of screw tightening by torque up from electric driver 200

ㆍ Overall tightening completion signal output signal indicating completion of tightening received by the screw tightening prevention device other than the final stage when multiple screw tightening prevention devices are connected in cascade.

ㆍ OK signal indicating that screwing is completed normally

NG signal indicating that the workpiece was taken out during operation

ㆍ Complete tightening signal indicating completion of tightening, which is output by another screw tightening prevention device to the other screw tightening prevention device when multiple screw tightening prevention devices are cascaded.

In addition, in FIG. 1, although the state which monitors about the removal of three parts (parts A-C) is shown, the number of parts to monitor is not limited to three, and it is good to be an arbitrary positive integer. Of course. In this case, not all parts that monitor the takeout are used for screwing, and even if the part is not used, the takeout is monitored so that the operator does not output an OK signal if the part is accidentally used. have. For example, in the following embodiment, although the component A and the component B are used and the component C is not used, the removal of all of these components A-C is monitored.

As shown in FIG. 2, the screw tightening prevention device 100 includes a CPU 10 for controlling the processing operation in the screw tightening prevention device 100, and a worker on the surface of the device. And an operation input unit 20 for initial setting, and a display unit 30 for displaying the input state from the operation input unit 20 and the processing result by the CPU 10. The display unit 30 is a visible display means such as an LED or a text image, and may include alarm notification means such as a buzzer together with the display unit. The screw tightening prevention device 100 includes a signal input / output unit 40, a storage unit 50 for storing programs and data for controlling the operation of the screw tightening prevention device 100, and an electric driver 200. It further comprises a power supply unit 60 for supplying power to the. In addition, the power supply ON / OFF control signal may be supplied to the electric driver 200 instead of the power supply unit 60, and power may be supplied to the electric driver 200 according to the control signal.

A control operation by the CPU 10 in the screw tightening prevention device 100 will be described with reference to the flowcharts of FIGS. 3 to 5. Before starting the screwing operation, the worker performs the initial setting by operating the operation input unit 20 while using the display unit 30. Initially set data are the score of the screw to be tightened, the score of the parts A and B, and the setting time of the screw tightening prediction timer described later, and the set data is stored in the storage unit 50 in step S1. In step S2, the CPU 10 turns on the transistor for all fastening completion signals, which will be described later, and reads the setting contents from the storage unit 50 into the CPU 10 in step S3. Thus, the initial setting is completed. In addition, the work is arranged at a predetermined work station by a worker.

In the case where the screw tightening prevention device 100 is used alone, it is not necessary to provide a transistor for the entire fastening completion signal. Therefore, step S2 (and step S24 to be described later) is unnecessary. In this embodiment, a case where a screw tightening prevention device which can be used in a plurality of subordinate connections can be used alone will be described.

In this state, the CPU 10 monitors the WORK signal in step S4, and determines that the work is placed on the work station (work placing stand) when the WORK signal is input. Subsequently, the process proceeds to step S5 and outputs a power ON signal to the power supply unit 60 to supply power to the electric driver 200. As a result, the electric driver 200 becomes usable.

When the CPU 10 determines that the work has been released based on the WORK signal in step S6 thereafter, the CPU 10 outputs a power off signal to the power supply unit 60 in step S7, and outputs an NG signal in step S8. It outputs and warns that the workpiece | work was detached from the display part 30. When the warning by the NG signal is displayed, the process returns to step S4, whereby the worker resets the work, and the processing of the CPU 10 and the screwing operation by the worker can be continued. If it is determined that the workpiece has not been released, the process proceeds from step S6 to step S9, and it is determined whether or not the component A has been taken out by monitoring the PART (A) signal.

When the component A is taken out, it progresses from step S9 to step S10, and in step S10 the number of remaining points of the component A is subtracted by one. If the component A has not been taken out, the flow advances to step S11 to determine whether or not the component B has been removed by monitoring the PART (B) signal. When the component B is taken out, it progresses to step S12 and the remaining score of the component B is subtracted by one. If the component B is not taken out, the process proceeds to step S13. In the setting of this embodiment, the parts A and B are set to be taken out. In other settings, the parts C may be taken out, so that the PART (C) signal from the part ejection sensor of the parts C Is entered. Therefore, in step S13, the PART (C) signal is monitored to determine whether or not the component C is taken out. When the component C is taken out, it is accidentally removed, so in step S7, the power supply OFF signal is output to the power supply unit 60, and in step S8, the NG signal is output and a warning is displayed on the display unit 30.

In other words, in this embodiment, the CPU 10 monitors all the input ports to which the component ejection detection sensor may be connected, that is, the components A and B set by monitoring the PART (A), PART (B) and PART (C) signals. A warning is also generated when other parts C are taken out. As a result, it is possible to prevent wrong removal of the parts other than the set parts.

In step S13, when the component C is not taken out, it progresses to step S14 of FIG. 4 and it is determined in step S14-S19 whether there was a screw fastening.

That is, first in step S14, it is determined whether or not the electric driver 200 is rotating. If the electric screwdriver 200 is not rotating, the process returns to step S6, and if it is rotating, the process proceeds to step S15 to start the screw tightening prediction timer. The time-up time of this screw tightening prediction timer is set in advance according to the length of the screw in step S1. After that, in step S16, it is determined whether or not the electric driver 200 is rotating again. This is to detect that the screw is shaking by suspending or screwing in during the screw tightening operation. When the electric screwdriver 200 is not rotating, it returns to step S6.

When the electric screwdriver 200 is rotating, it is determined in step S17 whether the screw tightening prediction time is up. If it is time-up, it is determined in step S18 whether the electric driver 200 is rotating again. If it is not rotating, it is determined in step S19 whether the TORQUE_UP signal is input. When the corresponding torque UP signal is input, this indicates that the screw is normally tightened, and therefore, in step S20, 1 is subtracted from the screw remaining score. In addition, the TORQUE＿UP signal is generated a predetermined time after the electric driver 200 reaches a predetermined tightening torque. If the TORQUE＿UP signal is not input, it means that the electric driver 200 is idle, and the flow returns to step S6.

In step S10, S12, and S20, the subtraction result may be displayed on the display unit 30 as the remaining points of the parts A and B and the remaining points of the screws.

In addition, in the above description, it is configured to determine whether or not by subtracting 1 from the remaining score for each attachment of the parts and screws to determine whether or not it is zero. Instead, it accumulates the score of completion of use and whether the value has reached the set value. It may be configured to determine whether or not.

Next, in step S21, the CPU 10 determines whether the total number of remaining points of the screw, the component A, and the component B is zero. If the determination result in step S21 is NO, the flow returns to step S6 to repeat the above-described steps S6 to S20.

If the remaining scores of the entire screw, component A, and component B become zero, the process proceeds from step S21 to step S22 of FIG. 5, and the power supply unit 60 is turned off to turn off the power supply to the electric driver 200. FIG. The power supply OFF signal is supplied, and in step S23, an OK signal indicating that the screwing is completed smoothly is output. The completion of the screwing is also displayed on the display unit 30. The worker can see that the screwing operation in the electric screwdriver 200 connected to the screw tightening prevention device 100 is completed by looking at the completion indication of the screwing in the display unit 30. The worker thus takes the work out of the workstation. In step S24, the entire tightening completion signal is output. In this example, since the screw tightening prevention device 100 is used alone, the entire tightening completion signal is not actually output to the outside. That is, as will be described later, when the screw tightening prevention device 100 is used alone, the whole tightening completion signal is in a state of being input, and the flow proceeds from step S25 to step S26. Since the workpiece has been released, the flow proceeds to Step S27 again, and the output of the OK signal is turned OFF.

Next, with reference to FIG. 6 and FIG. 3 thru | or FIG. 5 mentioned above, the case where the several screw tightening prevention device shown in FIG. 1 was cascaded is demonstrated. In Fig. 6, n (but n is an integer of 2 or more) n screw tightening prevention devices 100 (apparatus 1, apparatus 2, ..., apparatus n) are cascaded. The case where the electric screwdriver 200 (the electric screwdriver 1, the electric screwdriver 2, ..., the electric screwdriver n) is correspondingly connected to the apparatus 1-n is illustrated.

In this example, the PART () signal indicating the removal of the part is not input to each screw tightening prevention device. Of course, such a PART () signal may be input. In addition, when the PART () signal is not input, the processing steps related to the parts of steps S9 to S13 of FIG. 3 are unnecessary, and the determination formula relating to the parts in step S21 of FIG. 4 is also unnecessary.

In addition, instead of connecting a separate electric driver to each of the screw tightening prevention devices, the same electric driver may be connected to several or all of the screw tightening prevention devices.

When the screw tightening prevention device is connected in cascade, in the device of the latter stage, the OK signal is input from the device in front of the device instead of the WORK signal. In other words, as shown in Fig. 6, the OK signal from the preceding device is recognized as the WORK signal in the subsequent device. Therefore, in the apparatus of the subsequent stage, whether or not an OK signal (occured in step S23 in FIG. 5) is received from the apparatus of the preceding stage is equivalent to whether or not a WORK signal is received, and therefore, it is determined in step S4 of FIG. The subsequent steps are not executed unless it is determined in step S4 that the OK signal has been received.

As described above, in the device i at the rear stage, the screwing operation cannot be started because no power is supplied to the electric driver i unless the OK signal from the device i-1 at the front stage is supplied. Therefore, even if the screwing completion of the front end is terminated even though the screwing completion is not displayed on the display part 30, an operator can recognize that the work of the front end was inadequate.

Before starting work, the operator operates the operation input unit 20 of each device 1 to n to store the data initially set in step S1 in the storage unit 50. Then, the transistor for the entire fastening completion signal is turned on. In the screw tightening prevention device 100, when the phototransistor of the photocoupler FC is non-conductive, the entire fastening completion signal is input. Therefore, as shown in Fig. 6, when the device n at the final stage turns on the transistor Tr for output of the entire fastening completion signal, the phototransistors of the photocouplers FC of the devices 1 to n-1 are In the ON state, the apparatus 1 to apparatus n-1 are in a state in which the entire fastening completion signal is not input. And when the work is set in the workstation, the WORK signal is supplied to the device (1). The apparatus 1 detects this, and the apparatus 1 supplies an ON signal to the power supply unit 60 so as to supply power to the electric driver 200-1 (step S5). Thereby, electric power is supplied to the electric driver 200-1. When the screwing operation is properly performed under the control of the apparatus 1, the OFF signal is supplied to the power supply unit 60, the power of the electric driver 200-1 is cut off (step S22), and the apparatus 2 Generate an OK signal (step S23).

In the step S23 of Fig. 5, the device 1 outputs the entire fastening completion signal by turning off the entire fastening completion signal output transistor Tr, and the whole of the fastening completion signal is output between the other devices 2 and n. The signal line for transmitting the fastening completion signal is not connected (that is, the transistor Tr for outputting the entire fastening completion signal of the device 1 is not connected to another device). As shown in Fig. 6, only the entire fastening completion signal from the device n at the final stage is set to be transmitted to the other devices 1 to n-1 through the signal line L. As described above, when the phototransistor of the photocoupler FC of each device is in a non-conductive state, the entire fastening completion signal is input. In the case of using the screw tightening prevention device as a unit, the entire fastening completion signal is input because the input terminal of the photocoupler is open.

Thereafter, the device 1 monitors the signal transmitted through the signal line L in step S25 of FIG. 5, and determines whether or not the device n at the final stage outputs the entire fastening completion signal. When the entire tightening completion signal is output, it is determined in step S26 whether the workpiece is released or not. If so, proceed to step S27 to turn off the OK signal.

On the other hand, when it is determined in step S25 that the entire fastening completion signal is not input, that is, when the phototransistor of the photocoupler FC is conducting, the process proceeds to step S28 to determine whether or not the workpiece is released and is released. In step S29, the output of the OK signal is turned OFF. If it is not released, the ON signal is output in step S30. In either case, the control returns to step S25. When the work is released, the OK signal is turned off in step S29, and thereafter, the work may be placed again upon returning to step S28 through step S25. In response to such a case, the OK signal once turned off is turned on again in step S30.

In the apparatus 2, when it is determined that the OK signal (= WORK signal) is supplied, the electric screwdriver 2 is supplied with power, and the set screw tightening operation is executed. As a result, an OFF signal and an OK signal are generated when the proper screwing operation is executed. Thereafter, the process is executed similarly to the case of the apparatus 1.

Similarly, if the screwing operation set in the device n at the final stage is appropriately executed, the device n outputs an OK signal. As a result, all set screwing operations are completed. The device n then outputs the entire fastening complete signal in step S24. The signal is output by turning off the entire fastening completion signal output transistor Tr of the device n, and is transmitted to the other devices 1 to n-1. As a result, the phototransistors of these other apparatuses 1 to n-1 are turned off, and each apparatus determines that the entire fastening completion signal is input in step S25 of FIG. In this state, the worker removes the work from the workstation.

As a result, each device 1-n determines that the workpiece has been released in step S26, and turns off the output of the OK signal in step S27.

 The present invention having the above structure can construct a system equivalent to the case of using the sequence control apparatus without using an external sequence control apparatus.

In addition, when the total screw score is set in one screw tightening prevention device, it is impossible to judge whether it is good or bad after all the work is finished. In the present invention, the screw is connected to a plurality of screw tightening prevention devices that are cascaded. Since the scores are properly distributed, it is possible to output a good or bad judgment every time the work on one screw tightening prevention device is finished. Therefore, it is easy to specify the defective part, and furthermore, the correction of the defective part is easy.

Furthermore, in the present invention, not only the number of screws but also the number of one or more parts to be fixed to the work can be set in each screw tightening prevention device, and screw fastening can be determined whether they are properly used or not. You can support your work more appropriately.

In addition, the screw tightening prevention device can be used as a single group, and the number of subordinate connections is not limited, which has a great effect on initial cost and time saving. Furthermore, it is flexible to cope with changes in the production process after introduction. It is also effective in terms of running cost and time since it is possible.

Therefore, it can greatly contribute to reducing the production cost of the product.

Claims (20)

In the device for preventing the screw tightening when screwing parts to the workpiece, First setting means for setting one or a plurality of parts to be attached to the work; Second setting means for setting a score of screwing required when attaching the part to the workpiece; First calculating means for calculating a residual score of screw tightening by detecting a signal generated each time the screw is tightened; First determining means for determining which part is actually taken out by detecting a signal generated each time the part is actually taken out; When it is determined whether all the parts set by the first setting means have been taken out, and the remaining score of the screw tightening obtained by the first calculating means is judged, and when all the parts are taken out and it is determined that the remaining score of the screw tightening is zero. Second judging means for outputting a completion signal indicating completion of the screwing operation to the controller; Third judging means for judging whether or not the workpiece is disposed at a work position; Control signal for turning on the power of the electric driver when the parts and the screw tightening points are set by the first and second setting means, and when it is determined by the third determining means that the workpiece is arranged at the working position. Means for outputting; And And said second judging means includes means for outputting a control signal for turning off the power of the electric driver when all parts are removed and the remaining number of screw tightening is determined to be zero. Fastening prevention device. delete delete In the device for preventing the screw tightening when screwing parts to the workpiece, First setting means for setting a score of one or a plurality of parts to be attached to the work; Second setting means for setting a score of screwing required when attaching the part to the workpiece; First calculating means for calculating a residual score of the part by detecting a signal generated each time the part is actually taken out; Second calculating means for calculating a remaining score of screw tightening by detecting a signal generated each time the screw is tightened; First determining means for monitoring the remaining score of the parts and the remaining score of the screw tightening obtained by the first and second calculating means, and outputting a completion signal indicating completion of the screwing operation when they are determined to be zero together; Second judging means for judging whether or not the workpiece is arranged at the work position; The control signal for turning on the power of the electric driver when the parts score and the screw tightening score are set by the first and second setting means, and when it is determined by the second judging means that the workpiece is arranged at the work position. Means for outputting; And And a means for outputting a control signal for turning off the power of the electric driver when the first judging means determines that both the component remaining score and the screw tightening remaining score are both zero. Prevention device. delete delete A device for preventing screwing forgetting when screwing a part on a work, and in a screw tightening prevention device that can be used in a single or multiple subordinate connection, First setting means for setting a score of screw tightening necessary for attaching the part to the workpiece, First calculating means for calculating a residual score of screw tightening by detecting a signal generated each time the screw is tightened; First judgment means for monitoring the remaining score of the screw tightening obtained by the first calculation means, and outputting a completion signal indicating completion of the screwing operation when determining that the remaining score is zero; When a plurality of screw tightening prevention device is used in cascade connection, the screw tightening forget, characterized in that the at least the first calculation means is not operated unless the completion signal is output from the screw tightening forget prevention device of the front end Prevention device. The method of claim 7, wherein When the first judging means determines that the screw tightening residual score is zero, the screw-off forgetting apparatus further includes a power-off signal output means for outputting a control signal for turning off the power of the used electric driver. Prevention device. The method according to claim 7 or 8, Second setting means for setting one or a plurality of parts to be attached to the work; Further comprising second judging means for determining which part is actually taken out by detecting a signal generated each time the part is actually taken out, The first judging means judges whether all the parts set by the second setting means have been taken out, and also judges the remaining score of the screw tightening obtained by the first calculating means, all the parts are taken out, and the remaining score of the screw tightening. And outputting a completion signal indicative of completion of the screwing operation when it is determined to be zero. The method of claim 9, The power OFF signal output means is configured such that the first judging means outputs a control signal for turning off the power of the electric driver when all the parts are removed and the remaining number of screw tightening is determined to be zero. Screw tightening prevention device. The method according to claim 7 or 8, Third setting means for setting a score of one or a plurality of parts to which the parts are to be attached to the work; Further comprising second calculating means for calculating a residual score of the part by detecting a signal generated each time the part is actually taken out, The first judging means monitors the remaining score of the screw tightening and the remaining score of the parts obtained by the first and second calculating means, and outputs a completion signal indicating completion of the screwing operation when they are determined to be zero together. Screw tightening prevention device characterized in that the. The method of claim 11, The power OFF signal output means is configured to output a control signal for turning off the power of the used electric driver when the first judging means determines that both the screw tightening remaining score and the component remaining score are both zero. Screw tightening prevention device. The method according to claim 7 or 8, And a third judging means for judging whether or not the workpiece is arranged at the work position. The method of claim 13, When the score of the screw tightening is set by the first setting means, and when it is determined by the third determining means that the work is arranged at the work position, it outputs a control signal for turning on the power of the electric driver to be used. A screw tightening prevention device, characterized in that it further comprises a power ON signal output means. The method of claim 13, Outputs a control signal for turning on the power of the electric driver when the screw tightening points and parts are set by the first and second setting means, and when it is determined by the third determining means that the workpiece is arranged at the work position. And a first power ON signal output means. The method of claim 13, When the screw tightening score and the component score are set by the first and third setting means, and it is determined by the third determining means that the workpiece is arranged at the work position, the power supply for turning on the power of the electric driver to be used is turned on. And a second power supply ON signal output means for outputting a control signal. The method of claim 13, Means for operating the at least first calculation means when the plurality of cascaded anti-fastening devices are connected to each other in the first stage, and when it is determined by the third judging means that the workpiece is arranged at the work position. Screw tightening prevention device characterized in that it further comprises. The method according to claim 7 or 8, In case of using multiple casing prevention devices, Means for outputting a complete tightening completion signal to indicate that the tightening operation in all the screw tightening prevention devices is completed; And a means for turning off the completion signal outputted by the screw only when the screw tightening prevention device of the last stage outputs the entire tightening completion signal. The method of claim 18, Means for enabling at least the first calculation means thereof to be operable when it is determined that the workpiece is arranged at the work position by the third judging means when the screw tightening prevention device is used alone; Means for receiving a total fastening completion signal, and means for receiving a total fastening completion signal which always generates the same output as when a total fastening complete signal is received when a screw tightening prevention device is used alone; The screw tightening prevention device further comprises a determining means for determining the output of the entire tightening completion signal receiving means after the outputting the completion signal, and determining whether or not the entire tightening completion signal has been input. Anti-lost device. The method of claim 19, The entire fastening completion signal receiving means, When multiple screw tightening prevention devices are connected in cascade, it becomes non-conducting only when the entire fastening completion signal is received. Prevention device.

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