JPH0319777A - Screw tightening control device - Google Patents

Abstract

PURPOSE:To reduce a number of persons necessary for confirming screw tightening so as to decrease the cost of manufacture of a product by providing constitution such that a screw tightening worker side alarm of forgetting the screw tightening and screw mixing or the like is generated. CONSTITUTION:Action of loading a workpiece on a workpiece loading bed 1 is started, and a number of screws, taken out from a screw supplier 2 by a takeout signal input from the screw supplier during the time before the workpiece is unloaded from this workpiece loading bed 1, is counted, while a number of screws, tightened by a screw tightening signal from a driver 3 input just after this takeout signal is input, is counted. These counted values are compared with a screw-tightening quantity preset in a control unit 4, and when all the values are not in agreement, an alarm signal is output from a lamp 43 and a buzzer 44, and an operator is informed of the effect.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a screw tightening management device, and more particularly, to a management device that can prevent forgetting to tighten a screw or mixing up screws during screw tightening work. [Prior art] Conventionally, in product assembly work, parts are often assembled using a screwdriver, and in such cases, the worker uses a screwdriver to match each screw tightening point one by one with a screw aligner. A screwdriver is used to tighten the screws. In addition, in recent years, some companies have automated this screw tightening using machines such as Roboso 1. [Problems to be Solved by the Invention] However, when an operator performs screw tightening work, there are problems in that he or she may forget to tighten the screw or use the wrong type of screw. Conventionally, these cracks have been detected by marking the eagle's head or by visual inspection, but this requires additional personnel, which increases costs, is complicated, and is difficult to fully confirm. It was difficult. In addition, when tightening screws using a machine, in addition to the problem of not tightening the screws properly, there are also cases where the screws are not tightened properly, resulting in loose tightening or loose screws, which can be detected visually. The process of doing so was necessary. The purpose of the present invention is to solve the problems encountered in the conventional screw tightening work, and to automatically detect problems in the screw tightening work such as forgetting to tighten a screw or mixing screws, and tightening the screws. To provide a screw tightening management device capable of issuing a warning to a worker, reducing the number of personnel required to confirm screw tightening, and lowering product manufacturing costs. [Means for Solving the Problems] A screw tightening management device of a wooden invention that achieves the above object includes a work mounting table capable of outputting a signal indicating whether or not a work to be screwed is loaded, and a screw tightening table from which a screw is taken out. A screw feeder capable of outputting a take-out signal every time a screw tightening operation is completed, an electric screwdriver capable of outputting a screw tightening signal when a screw tightening operation is completed, and each of the above-mentioned signals from the workpiece mounting table, screw feeder, and electric screwdriver are input. and a control device capable of setting the number of screws to be tightened on the workpiece, and the control device controls the number of screws to be tightened set in the control device while the workpiece is loaded on the workpiece mounting table; Compare the count value of the take-out signal input from the screw U (roller) and the count number of the screw tightening signal from the tri-har inputted immediately after the input of the take-out signal of the screw U, and output an alarm signal if they do not match. [Operation] The screw tightening management device of the present invention starts operating when a workpiece is loaded on the workpiece mounting table, and until the workpiece is unloaded from the workpiece mounting table, The number of screws taken out from the screw feeder is counted by 81 according to the take-out signal input from the screw feeder, and the number of screws tightened is counted by the screw tightening signal from the driver that is input immediately after the input of this take-out number. 41, and compares these counted values with the number of screws to be tightened that is preset in the control device, and outputs an alarm signal if they do not match. (Example) The present invention will be implemented using the attached drawings below. An example will be explained in detail. Fig. 1 is a block diagram showing the construction of an embodiment of the screw tightening management device of the present invention. In the figure, l is a workpiece mounting table, 2 is a screw feeder, and 3 is an electric screwdriver. , 4 indicates a control device, and 4 indicates a control circuit.The workpiece mounting table L has a workpiece mounting portion H, and in the center of this workpiece mounting portion, there is a workpiece detection device for determining whether or not a workpiece is loaded. A sensor 12 is provided.No. 43 indicating the presence or absence of a workpiece from the workpiece detection sensor 12 is inputted to the control circuit 4 via a cable 13. The system operates as one cycle from "work present" to "work absent" indicating the presence or absence of a workpiece.The screw feeder 2 aligns the built-in screws and supplies them to the operator. The screw take-out section 2 is provided with screw take-out sensors 22 and 23.The screw take-out sensors 22 and 23 transmit a take-out signal to the control circuit through a cable 24 every time one screw is taken out from the screw feeder 2. 4
Enter. Electric screwdriver No. 3: This is used when the operator takes a screw and tightens it on the workpiece loaded on the workpiece mounting table 1. Plug the cord 3l into the specified power source,
When the operator presses a switch (not shown), the bit 32 at the tip is rotated. The operator attaches the screw taken out from the screw feeder 2, fits the hit 32 into the groove provided in the head of this screw, turns on the switch, rotates the bin 32, and tightens the screw to the workpiece.] Let's go. Generally, the electric screwdriver 3 has a built-in control device that tightens the screw at a predetermined 1.Luke (setting can be changed). , 5 6 seems to be idling. The electric screwdriver 3 of this embodiment is one that outputs a 1-lookup signal from the output terminal 33 of the electric screwdriver 3 during idle rotation after completion of screw tightening. The torque amplifier signal output from the output terminal 33 is input to the control circuit 4 through the cable 34. a signal indicating whether or not a workpiece is loaded from the workpiece mounting table 1;
Control circuit Fl84 to which the take-out signal from the screw feeder 2 and the torque-up signal from the electric L-Liha 3 are input.
In this embodiment, a screw tightening point number setting switch 41, a screw tightening point number indicator 42, a warning lamp 43, a buzzer 44, and a reset switch 45 are provided. In this embodiment, the screw tightening point number setting switch 4l is controlled by the 10 key, and the number of screws to be tightened on the workpiece can be set by key operation, and the set screw tightening point number is displayed as a digital value on the display 42. It is now displayed as . Further, when a screw is not tightened properly or an eagle is mixed in, the warning lamp 43 lights up or blinks, and the buzzer 44 emits a warning sound. The lighting or flashing of the warning lamp 43 and the warning sound of the buzzer 44 are stopped by pressing the reset switch 45. Next, the operation of the control circuit 4 in the embodiment configured as shown in FIG. 1 will be explained using flowchart 1 in FIG. The routine shown in FIG. 2 starts at 1 when the control circuit 4 is activated. In step 201, first, the number I of screws to be tightened set by the screw tightening point number setting switch 41 of the control circuit 4 is read. Then, in the subsequent step 202G, it is determined whether or not the workpiece is loaded on the workpiece mounting portion 11 of the workpiece mounting table 1 (jig) based on the signal from the workpiece detection sensor 12, and the steps are continued until the workpiece is loaded. It does not proceed to 203. When a workpiece is loaded on the workpiece placement section 11 of the workpiece placement table 1 and a signal indicating the presence of a workpiece is inputted to the control circuit 4 via the cable 13, the process proceeds from step 202 to step 2036, where the number of screws to be taken out is counted 4ifiN.
and 1. Clear the lower count value of the lookup signal and set it to O. Steps 204 to 206 are for determining the operator's actions, and it is determined whether the operator has unloaded the workpiece from the workpiece mounting table 1, tightened screws using the electric screwdriver 3, or screwed the screw feeder 2. Determine if you have taken out the sardine. That is, in step 204, it is determined based on the signal from the workpiece mounting table 1 whether or not the workpiece has been unloaded;
If the load has been unloaded, the process advances to step 212, but if the load has not been unloaded, the process advances to step 205. In step 205, it is determined whether or not the l-look-up signal from the electric screwdriver 3 has been input, and if the l-look-up signal has been input, the process returns to step 204, and if the torque amplifier signal has not been input, the process advances to step 206. Step 206 is for determining whether one screw has been taken out based on the signal input from the screw feeder 2. If no screw has been taken out, the process returns to step 204, and if a screw has been taken out, the process goes to step 207. Hiromu. In step 207, l is added to the number N of screws to be taken out, and the process proceeds to step 208. The stenops 208 to 210 are used to judge the operator's movements after the screw or screw feeder 2 has been taken out, and determine whether the operator has unloaded the workpiece from the workpiece mounting table 1 or not. It is determined by the signals from each device whether the screw is tightened using the screw feeder 2 or whether the screw is taken out from the screw feeder 2. That is, the stenoop 208 determines whether or not the workpiece has been unloaded from the workpiece mounting table 1. If the workpiece has been unloaded, the process proceeds to step 212, but if the workpiece has not been unloaded, the process proceeds to step 209. In step 209, it is determined whether or not the torque up signal from the electric screwdriver 3 has been input, and when the I-requambu signal has been input, the process proceeds to step 211, where the lower count value of the torque up signal is increased by 1, and the torque is increased. Count up signals and step 20
Returning to Step 4, if the 1.Lukuasop signal is not input, the process proceeds to Step 210. Step 210 is the screw 4R feeder 2
It is determined whether or not one screw has been taken out. If no screw has been taken out, the process returns to step 208, and if a screw has been taken out, the process returns to step 207. In the above control procedure, in step 209, after the I-look-up signal is input, the number is converted to aI, 9 to 10, and the lower count is increased by 1, and in step 205, even if the 1-look-up signal is input, The number is not counted, but this is because the worker takes into account the fact that he/she retightens the eagle. On the other hand, when it is determined in step 204 or step 208 that the workpiece has been unloaded, the process proceeds to step 212, where the number l of screws to be tightened is set in the control circuit 4 and the count value of the number of screws to be taken out inputted from the screw feeder 2. It is determined whether N and the count value T of the torque up signal inputted from the electric screwdriver 3 all match. If I=T=N, this indicates that the number of screws to be tightened has been taken out from the screw supply device 2 and correctly tightened to the workpiece by the electric driver 3, so that the screws for the next workpiece can be tightened properly. Returning to step 201 to determine the defect, I
When it is not =T=N, that is, when I+T, 1-1-N or T-#N, or when I≠T-I-N, the process proceeds to step 213 and an alarm signal is output. As a result, the lamp 43 lights up in the control circuit 4 and the buzzer goes off! J'-44 rings. Step 214 is to determine whether or not the recent switch 45 of the control circuit 4 has been pressed. Unless the recent switch 45 is pressed, the process does not proceed to step 215, and the lamp 43 continues to light and the buzzer 44 sounds. Continued IJ, Risenoj Suisochi 45
When is pressed, the output of the alarm signal is stopped by pressing the button 215, so the lamp 43 goes out and the buzzer 44 stops sounding. Here, the setting of the number I of screws to be tightened in the control circuit 4 is 2, and the operator is not able to correctly tighten the screws.

The flow of flowchart 1 in FIG. 2 when the work is performed will be explained. If the operator has performed the work correctly, ■ Load the workpiece onto the workpiece mounting table 1, ■ Take out only one screw from the screw feeder 2, ■ Tighten the screw on the workpiece with the electric screwdriver 3, ■ The second screw. The steps are as follows: 1. Take out the screw from the screw feeder 2, 1. Tighten the screws with the electric screwdriver 3, and 2. unload the workpiece from the workpiece mounting table. In this case, when the step 201 reads I-2 and the workpiece is loaded on the workpiece mounting table 1, steps 202→203
→ 204 → 205 → 206 → 207, and first, the number N of screws to be taken out is set to 1. Next, the process proceeds to steps 208→209→211, and the lower torque up count value is set to 1 using the steps 211. Then, return to the steno knob 204 and step 205 → 206 → 2
07, and in step 207, the number N of screws to be taken out is set to 2. Next, the process proceeds from steps 208 to 209 to 211, and in step 211, the torque up count 4fiT is set to 2, and the process returns to step 204. After tightening the second screw, the operator unloads the workpiece from the workpiece mounting table 1, so the process proceeds from step 204 to step 212, where the number of screws to be tightened, the number of screws to be taken out, N, and the torque amplifier signal are calculated. The numerical value T, that is, the number T of screws actually tightened is compared. If the work is performed correctly in this manner, 2=2=2, so the process returns to step 201 and moves on to the screw tightening confirmation work for the next workpiece. Note that if the operator once finishes tightening the screw and then decides that the screw has not been tightened for a minute and tightens the screw again, step 205 proceeds after step 204.
The answer is YES and the process returns to step 204, so after that,
Even if the workpiece is unloaded or tightened, no abnormality will occur. On the other hand, if the worker's screw tightening procedure is correct, but the worker forgets to tighten at least one screw and unloads the workpiece, the number of screws taken out N and 1. Since the process proceeds to step 212 while still being smaller than , the determination in step 212 becomes NO and the process proceeds to step 213, where an alarm signal is output and the lamp 43
lights up and buzzer 44 sounds. In addition, if a different type of screw is tightened to the workpiece, the process will proceed to step 212 before the number N of screws taken out in the stent 207 becomes the correct number, so an alarm signal will also be output and the lamp 4
3 will light up and the buzzer 44 will sound. As described above, according to the screw tightening management device of the present invention, if the operator does not tighten the screws correctly, the lamp 43
lights up and the buzzer 44 sounds, so problems such as forgetting to tighten the eagle or tightening a different type of eagle can be prevented. FIG. 3 is a structural diagram showing the configuration of another example of the screw tightening management device of the present invention, and shows the application of the present invention to a device that automatically tightens screws. In the figure, 1 is a workpiece mounting table, 2 is a screw feeder, 3 is an electric screwdriver, and 4
Reference numeral 4 indicates a control device, and 4 indicates a control circuit, and the same parts as those in the embodiment of FIG. In this embodiment, the electric screwdriver 3 is attached to a vertical movement mechanism 5, so that it can be moved to the upper limit with respect to the workpiece mounting table 1. Further, this vertical movement mechanism 5 is attached to a front-back movement mechanism 6 and is OJ-mounted, so that the electric driver 3 is movable in the front-back direction of the workpiece. Furthermore, since the longitudinal movement mechanism 6 is attached to the horizontal movement mechanism 7, the electric screwdriver 3 can move freely in the left and right directions of the workpiece. Devices that automatically tighten screws actually include a mechanism that automatically loads the workpiece onto the workpiece mounting table L, a mechanism that automatically loads the screw onto the electric L/Leper 3, etc.
These mechanisms are not shown in FIG. 3 because they are not directly related to the determination of whether screw tightening is good or bad according to the present invention. Further, in this embodiment, a screw tightening quality determining mechanism 8 is provided at the tip of the electric screwdriver 3. As shown in FIG. 4, this screw tightening quality determination mechanism 8 includes a sleeve 81 that surrounds the bit 32 of the electric 1-grip 3 and is movable in the longitudinal direction of the hit 32, and a sleeve 81 that protrudes from the tip of the sleeve 81. It is monitored by a gauge rod 82 and a position detection sensor 83 built into the sleeve 8l. The sleeve 81 is biased toward the tip of the bit I 32 by a spring (not shown), and the tip of the gauge rod 82 protruding from the sleeve 8I is positioned closer to the workpiece than the tip of the bit 32. It's starting to stand out. Therefore, when the electric screwdriver 3 descends when tightening a screw on a workpiece, the tip of the gauge rod 82 comes into contact with the workpiece surface 10 before the screw is tightened or after the screw has been tightened to a certain extent, and from then on the screw is tightened. As 9 is tightened, this sleeve 8
1 is inserted into the electric tricycle 3. When the screw 9 is properly tightened to the workpiece, the sleeve 8
The positional relationship between the gauge rod 82 of the sleeve 8l and the mounting base of the gauge rod 82 of the sleeve 8l is as shown in Fig. 4(a).
・The distance from the tip of 32 is X. At this time, the position detection sensor 83 built into the sleeve 81 detects the position between the bins 1 and 32.
The control circuit 4 detects the position of the screw and sends a signal indicating that the screw is properly tightened.
send to However, if the screw 9 is not properly tightened to the workpiece and the screw comes loose as shown in Figure 4(b),
The mounting base of the gauge rod 82 of the sleeve 81 and the bit 32
The distance from the tip to the tip is X - ΔI4. At this time, the position detection sensor 83 built into the sleeve 81 detects the
2 is detected and a signal indicating that there is a floating screw is sent to the control circuit 4. Next, the operation of the control circuit 4 in the embodiment configured as shown in FIG. 3 will be explained using flowchart 1 in FIGS. 5 and 6. The routine shown in FIG. 5 starts when the control circuit 4 is activated. In step 501, first, the workpiece is placed on the workpiece mounting table 1 (
The workpiece is fixed to the jig), and in the following step 502, it is checked whether the workpiece is correctly fixed to the jig or not.
step 503 only if it is determined that the
Then, the number M of screws to be tightened set by the screw tightening point number setting switch 41 of the control circuit 4 is read. Then, in the following step 504, the number of completed screw tightening B based on the count value 8 of the number of screws to be taken out and the count value of the 1.lux amplifier signal, and the number of screw tightening operations C of this device are cleared.
Make it. In step 505, the value of the number of screw tightening operations C is increased by 1, and the process proceeds to step 506, in which a process is executed to take out a screw from the screw feeder 2 and mount it on the electric screwdriver 3, and it is determined whether or not the screw has been mounted.・Step 50 until the screw is attached to the electric driver 3 as determined in step 507
I can't proceed to step 8. When the screw is attached to the electric screwdriver 3, in step 508, 1 is added to the number A of screws to be taken out, the process is performed to move the electric screwdriver 3 to the screw tightening position. Step 510 is to determine whether or not the electric screwdriver 3 is moved to the screw tightening position, lowered to the workpiece, and actually started screw tightening, and when it is determined that screw tightening has started, step 5] At this point, the screw tightening timer is started to count the tightening time of the screws 17 and 18. Then, in the following step 512, it is determined whether a specified time has elapsed since the start of screw tightening, and if the specified time has not elapsed, the process proceeds to step 513, and it is determined whether or not a torque up signal from the electric screwdriver 3 has been input. However, when the specified time has elapsed, the process proceeds to step 516↓ to perform a process to stop the screw tightening operation. This is because when a normal 6-thread screw is tightened into the workpiece, the 1-look up signal from the electric screwdriver 3 is input to the control circuit 4l within the specified time, and the electric screwdriver is turned off within the specified time. This is because if the 1.look-up signal from 3 is not input, it can be determined that the screw tightening is defective. In step 513, if the input of the 1.look-up signal is confirmed, the process proceeds to step 514, where it is determined whether or not there is a screw floating. This determination method is shown in Figure 4 (a) and (b).
As explained above, screw floating is determined based on the output signal from the position detection sensor 83 provided in the sleeve 81 at the tip of the electric screwdriver 3. If there is no loose screw, proceed to STEP 515 and complete screw tightening number B.
The value of is incremented by 1 and the process proceeds to step 519. However, if there is a loose screw, the process proceeds to II step 516 to perform a process to stop the screw tightening operation. In step 519, the number of screw tightening operations C is the number M of screw tightening operations.
Determine whether C<M, step 5
The process returns to step 05, but if C≧M, the process proceeds to step 520. The step knob 520 performs a process of unloading the workpiece from the workpiece mounting table 1, and the step knob 521 determines whether or not the workpiece has been unloaded from the workpiece mounting table 1. If it is determined that the workpiece has been unloaded from the workpiece mounting table 1, the process proceeds to step 7 600, where screw tightening quality processing is performed. The details of this process 6 for determining the quality of screw tightening will be described later with reference to FIG. If the screw tightening is normal, step 60
0, the process returns to step 501 to monitor the quality of the screw tightening process for the next workpiece. On the other hand, the screw tightening was not completed within the specified time and step 51
2, or if the result is NO in step 514 because the J screw is floating, the screw tightening operation is stopped in step 516, but after this, the steps 517 and 5186 are Then, it judges the instructions from the operator and moves on to the next operation. Step 51
7 determines whether a re-tightening signal from the operator has been input, and the operator adjusts the machine.
When the process of continuing the screw tightening currently being executed is taken, the process returns to step 510 and the same tightening operation is repeated. However, if the operator gives up on the screw tightening that is currently being executed and moves on to the next 'A comb tightening process, the process proceeds to step 519, where the process shifts to monitoring the next comb tightening process. Here, the detailed procedure of the screw tightening quality determination process will be explained using FIG. 6. First, in step 601, the number M of screws to be tightened set in the control circuit 4, the count value A of the number of screws to be taken out inputted from the screw feeder 2, and the count value B of the torque amplifier signal inputted from the electric screwdriver 3 are calculated. Determine whether they all match. If M=A=B, it indicates that the number of screws to be tightened has been taken out from the screw supply device 2 and tightened to the work by the electric screwdriver 3, so whether the screws of the next work are tightened or not. The process returns to step 501 to determine. However, when M = A-B, that is,
M-I-A, M≠13 or when A≠B, or M≠
When A-#B, the process proceeds to the steno panel 602 and outputs an alarm signal. As a result, the lamp 43 lights up in the control circuit 4 and the buzzer 44 sounds. In step 603, it is determined whether or not the reset switch 45 of the control circuit 4 has been pressed, and if the reset switch 45 is not pressed, the process does not proceed to step 604, and the lamp 43 continues to light up for 6 seconds. When the buzzer 44 continues to sound and the reset 1 switch 45 is pressed, the process proceeds to step 604 and stops the output of the alarm Nobuo, so the lamp 43 goes out and the buzzer 44 stops sounding. In the device that automatically tightens screws in the embodiment shown in Fig. 3, there is no mistake in the order in which the screws are first taken out from the screw feeder 2 and then tightened to the workpiece, so I can attach the screws to my electric screwdriver. In the case of defective screw tightening, empty screw tightening, or floating screw, a lamp 43 is turned on and a buzzer 44 is sounded to notify the operator of this, thereby eliminating screw tightening failures. [Effects of the Invention] As explained above, according to the screw tightening management device of the present invention, when screw tightening is performed by input, it is possible to prevent problems in the screw tightening work by an operator such as forgetting to tighten a screw or mixing screws. It is possible to automatically detect and issue a warning to the screw tightening operator, and when screw tightening is performed automatically, it is possible to issue a warning when it detects empty tightening or loose screws. As a result, there is an effect that the number of personnel required to check screw tightening can be reduced and the manufacturing cost of the product can be lowered.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the configuration of an embodiment of the screw tightening management device of the present invention, Fig. 2 is a flowchart showing an example of the control procedure of the control circuit of Fig. 1, and Fig. 3 is a screw of the wooden invention. A perspective view showing the structure of another embodiment of the tightening management device, FIG. 4(a)
, (b) is a partial side view showing the structure and operation of the tip of the electric screwdriver shown in FIG. 3, FIG. 5 is a flowchart showing an example of the control circuit of the control circuit shown in FIG. 3, and FIG. is the fifth
1 is a flowchart 1 showing a detailed procedure of the screw tightening quality determination process shown in the figure. DESCRIPTION OF SYMBOLS 1... Workpiece mounting table, 2... Screw feeder, 3... Electric screwdriver, 4... Control circuit, 5... Vertical direction movement mechanism, 6... Back and forth direction movement mechanism, 7...・Left-right movement mechanism, 12 22 23...Sensor, 41...
・Screw tightening point setting switch, 43...Lamp, 44・
・・Buzzer, 45・Reset・Nl・Switch. Patent Application Hitofujitsu Ten Co., Ltd. Patent Application Agent

Claims (1)

[Claims] A workpiece mounting table (1) capable of outputting a signal indicating whether or not a workpiece to be screwed is loaded; and a screw feeder (2) capable of outputting a takeout signal each time a screw is taken out. The signals from the electric screwdriver (3), which can output a screw tightening signal when the screw tightening operation is completed, the workpiece mounting table (1), the screw feeder (2), and the electric screwdriver (3) are inputted. In addition, a control device (4
), the control device (4) controls the number of screws to be tightened set in the control device (4) and the number of screws to be tightened while the workpiece is loaded on the workpiece mounting table (1). Compares the count value of the take-out signal input from the supply device (2) with the count value of the screw tightening signal input from the driver (3) immediately after inputting this take-out signal, and outputs an alarm signal if they do not match. A screw tightening management device characterized by: