JP2003001360A - Riveting error detection method and device for riveting apparatus of self-piercing rivet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect not only a riveting error that can be detected with an existing detection method, but also a different kind of riveting error from the aforementioned error with reference to a self-piercing rivet. SOLUTION: With reference to the riveting apparatus of the self-piercing rivet, an upper limit normality characteristic curve 37 that defines an upper limit of a normal riveting range and a lower limit normality characteristic curve 38 that defines a lower limit of the normal riveting range are provided on a graph showing a riveting stroke and a riveting load on a X-Y coordinate system in order to detect the riveting error of the self-piercing rivet, and the error is detectable with the existing method. Between the upper and lower limit normality characteristic curves, displayed are upper and lower limit abnormality characteristic curves 39, 41 obtained from another riveting error different from the aforementioned error. The detection device detects a different kind of riveting error when a plotted curve 45 of data value measured during riveting exists in between both the curves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to detecting a fastening abnormality of an automatic perforation type rivet fastening device, and particularly, in sheet metal assembling work (particularly assembling work of aluminum body) such as automobile assembly, two or three sheets are assembled. The present invention relates to a method and a device for detecting a fastening abnormality of an automatic punching rivet in an automatic punching rivet fastening device that fastens the plate member (or the plate member and parts) using an automatic punching rivet.

[0002]

2. Description of the Related Art An example of an automatic piercing rivet setting machine is described in Japanese Patent Publication No. 8-505087. FIG. 1 shows an example of a self-piercing rivet. The self-piercing rivet consists of a flange-shaped head and legs that hang down from the head. When punched into a member to be fastened, which is, for example, two body panels, by punches and dies, the legs pierce the panel (drill). While deforming so that the tips of the legs expand, both panels are connected to each other by the deforming and expanding leg portion and the head. The self-piercing rivet is suitable for connecting aluminum bodies that are not suitable for welding, and the body of automobiles, which is currently being reduced in weight, uses the aluminum body, and the demand for the self-piercing rivet is increasing. In this self-piercing rivet, when the member to be fastened is, for example, two body panels, the leg penetrates the flange side panel but the leg tip side panel does not penetrate the leg tip. Therefore, it is necessary to prevent not only insufficient tightening force but also excessive tightening force such that the leg tip side penetrates the panel.

The automatic perforation type rivet fastening device currently used is equipped with a device for detecting the driving stroke and the driving load of the automatic perforation type rivet to detect fastening abnormality such as insufficient driving and excessive driving. There is. This fastening abnormality detecting device displays a normal upper limit characteristic curve that determines the upper limit of the normal fastening range and a normal lower limit characteristic curve that determines the lower limit of the normal fastening range on a graph that displays the driving stroke and the driving load on the XY coordinates. A monitor as a display means for detecting the driving stroke and driving load of the automatic perforation rivet during driving and plotting on the graph, processing the input data from the pressure sensor, scale, etc. And a means for plotting in a graph, and detecting that the plotted value deviates outside between the normal upper limit characteristic curve and the normal lower limit characteristic curve across the characteristic curve to detect fastening abnormality of the automatic piercing rivet. It has a detection means. For example, when the plot value is lower than the normal lower limit characteristic curve, the implantation is insufficient, and when it is higher than the normal upper limit characteristic curve, the implantation is excessive.

FIG. 1 shows a graph on a monitor. The monitor sets the driving stroke of the automatic drilling rivet as the X axis (unit is mm), and the driving load of the automatic drilling rivet for that driving stroke is the Y axis (unit is kN).
(Kilonewton)) is displayed, and the characteristic curves A and B serving as the reference are displayed on this graph. The upper characteristic curve A is a characteristic curve that defines an upper limit of normal engagement, that is, a normal upper limit characteristic curve, and the lower characteristic curve B is a characteristic curve that defines a lower limit of normal engagement, that is, a normal lower limit characteristic curve. At present, when the input data of the driving stroke and the driving load of the driving boring rivet being driven is plotted between the normal upper limit characteristic curve A and the normal lower limit characteristic curve B, the driving is normal. And the plot value is the normal upper limit characteristic curve A or the normal lower limit characteristic curve B.
If it crosses the outer sides of both curves, the automatic piercing rivet determines that the fastening is abnormal, and detects the fastening abnormality. The normal upper limit characteristic curve A or the normal lower limit characteristic curve B, which is the above-mentioned reference characteristic curve, is acquired by a test punching of an automatic punching rivet. The value of the characteristic curves can be determined by a test, and the value can be arbitrarily set within a range in which normal fastening can be obtained. The detected fastening abnormality is displayed to the operator as an alarm, and the fastening device stops its operation.

[0005]

As described above, in the present method for detecting a fastening abnormality, the plot value of the driven self-piercing rivet crosses the normal upper limit characteristic curve A or the normal lower limit characteristic curve B. If the user goes out, it is determined that the fastening abnormality has occurred, the operator is notified of the fastening abnormality, and the fastening device is stopped. However, it has been found that the detection of such fastening abnormality does not detect all actual fastening abnormalities. In FIG. 1, a curve C of the plot value of the self-piercing rivet during driving is displayed. This rises almost linearly between the normal upper limit characteristic curve A and the normal lower limit characteristic curve B. According to the current detection method, this plot value is a normal fastening and is not judged to be an abnormal fastening. However, in reality, the self-piercing rivet fell over in the punch of the fastening device, and the fastening was not normally performed. As described above, the current abnormality detection method can detect the fastening abnormality such as excessive fastening or insufficient fastening, but cannot detect the fastening abnormality of a different type. In order to detect this different type of fastening abnormality, if the width of the normal upper limit characteristic curve A and the normal lower limit characteristic curve B is narrowed,
Many of the self-piercing rivets that have passed the fastening
There is a risk that it will be detected as a fastening error and will interfere with the fastening work. As described above, it has been found that the current method of detecting the fastening abnormality is not sufficient to detect the fastening abnormality of the self-piercing rivet.

Therefore, an object of the present invention is to detect a fastening abnormality of an automatic punching rivet which can be detected at present as it is, and also to detect a fastening abnormality different from the fastening abnormality, which is a fastening abnormality of the automatic punching rivet. A detection method and device are provided.

[0007]

In order to achieve the above object, the present invention provides a self-piercing rivet consisting of a flange-shaped head portion and an annular leg depending from the head portion. A self-piercing rivet fastening device that drives into a member to be fastened and deforms the leg so that the leg tip expands while punching the leg, and the deformable spreading leg and the head connect the plurality of fastened members to each other. In order to detect the fastening abnormality of the automatic drilling type rivet, the normal upper limit characteristic curve and the lower limit of the normal fastening range that determine the upper limit of the normal fastening range on the graph that displays the driving stroke and the driving load in XY coordinates are normal. The lower limit characteristic curve is displayed, and the driving stroke and the driving load of the automatic drilling rivet during driving are detected and plotted on the graph, and the plotted values are the normal upper limit characteristic curve and the normal lower limit. There is provided a method of detecting a deviation from between the characteristic curves to detect a fastening abnormality of the self-piercing rivet, which method further includes between the normal upper limit characteristic curve and the normal lower limit characteristic curve of the graph. , Displaying an abnormal upper limit characteristic curve and an abnormal lower limit characteristic curve obtained from a fastening abnormality different from the above fastening abnormality; the plot value of the automatic drilling rivet during driving is the abnormal upper limit characteristic curve and the abnormality. It is detected that it is between the lower limit characteristic curve and the other fastening abnormality of the automatic punching rivet;

Another method of detecting the fastening abnormality of the automatic punching rivet of the present invention is to store one abnormal characteristic curve pattern obtained from a fastening abnormality different from the above fastening abnormality as a reference template; The measured data up to the end of driving obtained from the plotted values of the automatic punching rivet during driving is saved as one frame of measured data; the difference between the reference template data and the measured data of one frame is calculated; It is characterized in that the value based on the difference is integrated and the another fastening abnormality is detected based on the magnitude.

Still another method of detecting the fastening abnormality of the self-piercing rivet according to the present invention is to provide one abnormal characteristic curve pattern obtained from a fastening abnormality different from the above fastening abnormality at a predetermined driving stroke. Is stored as a reference pattern consisting of data that changes in the following manner; actual measurement data of the driving load for the driving stroke obtained from the automatic punching rivet during driving is recorded as data that changes for each of the predetermined driving strokes; It is characterized in that the print data is compared with the data of the reference pattern, and the another fastening abnormality is detected based on the degree to which the print data approximates the reference pattern data.

According to the above-described method of the present invention, in addition to the conventional method using the normal upper limit characteristic curve and the normal lower limit characteristic curve, the setting is made from the abnormal fastening state other than the fastening abnormality such as insufficient fastening or excessive fastening. By simply adding the abnormal upper limit characteristic curve and the abnormal lower limit characteristic curve, or based on the template based on the reference curve obtained from the different fastening abnormality, the fastening abnormality that could not be detected in the past can be detected.

In the above method, the another fastening abnormality is
The self-piercing rivet may fall over in the punch of the self-piercing rivet fastening device, or the hardness of the material of the self-piercing rivet may be insufficient.

Further, according to the present invention, a self-piercing rivet comprising a flange-shaped head and an annular leg hanging from the head is driven into a plurality of members to be fastened by a punch and a die to perforate the leg. While deforming so that the tip of the leg expands,
A device for detecting a fastening abnormality of an automatic piercing rivet used in an automatic piercing rivet fastening device that connects the plurality of members to be fastened to each other by the deforming and expanding leg portion and the head, and is a driving stroke. The normal upper limit characteristic curve that determines the upper limit of the normal fastening range and the normal lower limit characteristic curve that determines the lower limit of the normal fastening range are displayed on the graph that displays the driving load in the XY coordinates, and the automatic drilling rivet A driving stroke and a driving load are detected and plotted on the graph, and it is detected that the plotted value deviates from between the normal upper limit characteristic curve and the normal lower limit characteristic curve, and a fastening abnormality detecting device for an automatic piercing rivet. The device is provided with an abnormal upper limit characteristic curve and an abnormal lower limit obtained from a fastening abnormality different from the fastening abnormality between the normal upper limit characteristic curve and the normal lower limit characteristic curve of the graph. A characteristic curve is displayed, and it is detected that the plot value of the automatic punching rivet during driving is between the abnormal upper limit characteristic curve and the abnormal lower limit characteristic curve, and the different type of the automatic punching rivet is detected. It is characterized by detecting the fastening abnormality of.

In the apparatus for detecting another fastening abnormality of the present invention, one abnormal characteristic curve pattern obtained from a fastening abnormality different from the above fastening abnormality is stored as a reference template, and the automatic perforation during driving is performed. The actual measurement data obtained from the plot value of the mold rivet until the end of driving is stored as one frame of actual measurement data, the difference between the reference template data and the one frame of actual measurement data is calculated, and a value based on the difference is calculated. It is characterized by integrating and detecting the other fastening abnormality based on the magnitude. Further, the device for detecting another fastening abnormality stores one abnormal characteristic curve pattern obtained from a fastening abnormality different from the above fastening abnormality as a reference pattern consisting of data that changes for each predetermined driving stroke, The measured data of the driving load with respect to the driving stroke obtained from the automatic punching rivet during driving is recorded as data that changes for each of the predetermined driving strokes, and the recorded data is compared with the data of the reference pattern. The other fastening abnormality is detected based on the degree to which the recording data approximates the reference pattern data.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Before describing an embodiment of the present invention, a current automatic perforation type rivet setting device 1 will be described with reference to FIG. The self-piercing rivet fastening device 1 includes a fastening unit 2 for fastening the self-piercing rivet, a control device 3 for controlling the operation of the fastening unit 2, and the fastening unit 2 as a plurality of panels 5 and 5A to be fastened. The robot 6 is provided as a means for moving the rivet to a predetermined portion, and the rivet feeding device 7 that automatically feeds the self-piercing rivet to the fastening portion 2. The control device 3 also controls the feeding of the self-piercing rivet of the rivet feeding device 7. The control device 3 is provided with a monitor 9, for example, a graph for displaying the driving stroke and the driving load in XY coordinates is displayed. From the rivet feeding device 7, a self-piercing rivet 1 is attached to the fastening portion 2.
A feeding tube 10 for continuously feeding one by one extends to the receiver mechanism 11 of the fastening portion 2. Since the rivet feeding of the rivet feeding device 7 is performed by the compressed air, the compressed air is fed to the rivet feeding device 7 by the pipe 13
Sourced from.

The fastening portion 2 is attached to the tip of the arm 14 of the articulated robot 6, a C-shaped frame 15, a die 17 attached to one end (lower end in the illustrated example) of the frame 15, and a die 17. A punch 18 mounted on the lower end of the receiver mechanism 11 at the other end (upper end) of the C-shaped frame 15 so as to be opposed to and detachable from the die 17, and a drive for moving the punch 18 to be detached from the die 17. And an electric motor 19. A lead screw is formed on the shaft of the electric motor 19, and the rotation of the electric motor gives the punch 18 a force to strongly push the self-piercing rivet held by the punch 18 toward the die 17. By reversing the electric motor 19, the punch 18 can be retracted (raised in the example as shown). Punch 18
At the tip of the rivet, the automatic piercing rivet sent from the receiver mechanism 17 is held. C-type frame 1
5 is a punch 1 where the panel 5 and 5A to be fastened are fastened.
8 and the die 17 are formed so as to be sandwiched vertically.

FIG. 3 shows how the self-piercing rivet 21 is fastened to the panels 5 and 5A by the fastening device 1. The self-piercing rivet 21 includes a flange-shaped head 22 and an annular leg 23 that hangs from the head 22. The self-piercing rivet 21 includes a punch 18 and a die 1.
7 is driven into a plurality of (two in the illustrated example, but may be three or more) panels (members to be fastened) 5 and 5A, and the leg 23 punches the panels 5A and 5 by this driving. The tips of the legs 23 are deformed so as to spread outward, and the panels 5A and 5 are connected to each other by the deforming and expanding leg portions 23 and the head 22. The self-piercing rivet 21 is suitable for connecting a panel made of an aluminum material that is not suitable for welding, and is also suitable for connecting an aluminum body of an automobile, which is currently being reduced in weight. As shown in FIG. 3, the self-piercing rivet 21 is fastened so that the leg 23 penetrates the flange-side panel 5A but the leg-end panel 5 does not penetrate the leg tip. As a result, the surface of the panel 5 has no holes, and airtightness and watertightness can be maintained high. Therefore, the self-piercing rivet 21
It is necessary not only to prevent the fastening force from being insufficient but also to prevent the fastening force from being excessive so that the leg tip side penetrates the panel.

The monitor 9 shown in FIG. 2 displays a graph showing the driving stroke and driving load of the automatic punching rivet in XY coordinates, and it is possible to monitor the fastening abnormality due to insufficient fastening force or excessive fastening force. It is like this. For such monitoring and control of fastening of the self-piercing rivet, the control device 3 has a hardware configuration as shown in FIG. That is, the control device 3 controls the central processing unit (CP
U) 25, a main memory 26 that performs arithmetic processing integrally with the CPU 25, and a monitor 9 having a display screen 27
A sequencer 29 for instructing and selecting an automatic operation of the fastening operation of the automatic punching rivet, driving load data from a pressure sensor (not shown) provided at the tip of the punch 18, a motor 19 of the fastening portion 2, or A data input unit 30 for inputting driving stroke data from a scale (not shown) indicating a moving length of the punch 18 provided on the lead screw, that is, a driving stroke of the automatic punching rivet, and the driving load data and the driving load. When the embedded stroke data is analog data, an A / D converter 31 for converting it into digital data, a storage device 32 such as a hard disk device for storing various data, and various types processed inside the control device 3 Data output unit 33 that outputs the data of the above, and various digital data processed internally is converted into analog data and output. Includes a D / A converter 34 to send to 33, it is connected to each other by a main bus 35 of the control apparatus 3, performs predetermined processes and functions.

As described above, the monitor 9 of the control device 3 detects the abnormal fastening of the automatic piercing rivet, so that the upper limit of the normal fastening range is displayed on the graph displaying the driving stroke and the driving load in the XY coordinates. The normal upper limit characteristic curve that defines the normal lower limit characteristic curve and the normal lower limit characteristic curve that defines the lower limit of the normal engagement range are displayed. In the graph of FIG. 1 described above, the normal upper limit characteristic curve A and the normal lower limit characteristic curve B are displayed. When the input data of the driving stroke and the driving load of the driven self-piercing rivet is plotted between the normal upper limit characteristic curve A and the normal lower limit characteristic curve B, the driving is normal. However, when the plotted value crosses the normal upper limit characteristic curve A or the normal lower limit characteristic curve B and is outside the both curves, the self-piercing rivet detects fastening abnormality due to insufficient fastening or excessive fastening force. The detected fastening abnormality is
It is displayed to the operator as an alarm and the fastening device stops its operation. The normal upper limit characteristic curve A or the normal lower limit characteristic curve B is acquired by a test punching of an automatic punching rivet or the like. The value of the characteristic curves can be determined by a test, and the value can be arbitrarily set within a range in which normal fastening can be obtained.

However, as described above with reference to FIG. 1, the detection of the fastening abnormality does not detect all the actual fastening abnormalities. For example, an abnormal fastening characteristic curve C that rises substantially linearly between the normal upper limit characteristic curve A and the normal lower limit characteristic curve B indicates that the automatic piercing rivet has fallen in the punch of the fastening device and fastening is normal. It is a plot value of what was not done in. Such fastening abnormality is different from the fastening abnormality such as excessive fastening or insufficient fastening, and cannot be detected by the present detection method.
As an example of a fastening abnormality of a type different from the fastening abnormality of over-tightening or under-tightening, there is a fastening abnormality caused by insufficient hardness of the material of the self-piercing rivet.

In the present invention, the type of fastening abnormality which is different from the fastening abnormality of over-fastening or under-fastening which cannot be detected by the present detection method without adding or modifying the hardware configuration is detected. To do. It demonstrates using FIG. 5-FIG. 8 which shows the graph which displays the driving stroke and driving load of an automatic drilling rivet displayed on the monitor 9 at XY coordinates. In FIG. 5, curves 37 and 38 are
The normal upper limit characteristic curve 37 and the normal lower limit characteristic curve 38, respectively, have already been described. The values of these curves can be set by test punching of an automatic drilling type rivet, and the values can be set arbitrarily within a range where normal fastening can be obtained. In the present invention, the normal upper limit characteristic curve 3
7 and the normal lower limit characteristic curve 38, a fastening abnormality other than a fastening abnormality such as excessive fastening or insufficient fastening (when the automatic punching rivet falls over in the punch, insufficient hardness of the material of the automatic punching rivet, etc.). The abnormal upper limit characteristic curve 39 and the abnormal lower limit characteristic curve 41, which are obtained from (fastening abnormality due to), are displayed.
These curves 39 and 41 are, for example, as shown by the curve C in FIG. 1, data obtained by driving an automatic perforation type rivet that is turned over in a punch, and an automatic perforation type rivet made of a material having insufficient hardness. It can be obtained from the input data. These data may be obtained by a test that results in abnormal fastening, or may be created using past data accumulated in the storage device 32 provided in the fastening device 1, a storage device of an external computer device, or the like. May be. Then, it is preferable to select each value of the abnormal upper limit characteristic curve 39 and the abnormal lower limit characteristic curve 41 and the width of both curves while checking the state of the abnormal fastening. The abnormal upper limit characteristic curve 39 and the abnormal lower limit characteristic curve 41 are created, for example, such that the curve C of FIG. 1 is in between, and the driving load data for the driving stroke of the automatic piercing rivet during driving. Is plotted between the abnormal upper limit characteristic curve 39 and the abnormal lower limit characteristic curve 41, and when curve C is obtained, it is detected as a fastening abnormality.

FIG. 6 shows a state in which a plot value curve 42 in which the values of the driving load data are plotted with respect to the driving stroke of the normally-fastened self-piercing rivet is displayed by being superimposed on the graph of FIG. . This plot value curve 4
2 is a normal upper limit characteristic curve 37 and a normal lower limit characteristic curve 3 up to a driving stroke of 6 mm, which is the end of driving.
8 and also not between the abnormal upper limit characteristic curve 39 and the abnormal lower limit characteristic curve 41. Therefore,
No fastening abnormality is detected. FIG. 7 shows a state in which a plot value curve 43, which is a curve different from that of FIG. 6 and in which the value of the driving load data is plotted with respect to the driving stroke of the automatic drilling rivet, is displayed by being superimposed on the graph of FIG. . The plot value curve 43 exceeds the normal upper limit characteristic curve 37 and comes out between the normal upper limit characteristic curve 37 and the normal lower limit characteristic curve 38 at the time of the driving stroke 5 mm before the end of driving. In this case, the automatic piercing rivet fastening device 1 detects the fastening abnormality and issues the fastening abnormality signal, and the detected fastening abnormality is monitored by the monitor 9 as an alarm.
Is displayed to the worker, and the fastening device 1 stops its operation.

FIG. 8 is different from that shown in FIGS. 6 and 7, and is a curved plot value curve 45 in which the values of the driving load data with respect to the driving stroke of the self-piercing rivet are plotted.
Is displayed on the graph of FIG. The plot value curve 45 falls between the normal upper limit characteristic curve 37 and the normal lower limit characteristic curve 38 up to the driving stroke of 6 mm at the end of driving. However, the plot value curve 45 lies between the abnormal upper limit characteristic curve 39 and the abnormal lower limit characteristic curve 41 up to the driving stroke of 6 mm.
In this case, the driven self-piercing rivet is not a fastening abnormality due to over-tightening or under-tightening, but another fastening abnormality (when the self-piercing rivet falls in the punch or The fastening abnormality is detected as a fastening abnormality due to insufficient hardness of the material of the rivet or the like. The automatic perforation type rivet fastening device 1 also issues a fastening abnormality signal when detecting the fastening abnormality, and the detected fastening abnormality is displayed to the operator as an alarm on the monitor 9 or the like, and the fastening device 1 stops its operation. To do. In the case of this fastening abnormality, a signal indicating that the fastening abnormality is not the fastening abnormality due to excessive fastening or insufficient fastening may be issued so that the operator can see the display. In this way, according to the present invention, in addition to the conventional management method using the normal upper limit characteristic curve and the normal lower limit characteristic curve, without changing the hardware of the automatic punching rivet fastening device 1, another fastening abnormal condition By simply adding the abnormal upper limit characteristic curve and the abnormal lower limit characteristic curve created and set from, it is possible to detect the fastening abnormality that could not be detected in the past.

In the above embodiment, an abnormal upper limit characteristic curve and an abnormal lower limit characteristic curve created and set from another fastening abnormal state are added to the graph, which is different from the fastening abnormality such as excessive fastening or insufficient fastening. Abnormality is detected. Hereinafter, a method of detecting another fastening abnormality different from the above embodiment will be described.

One of them is shown in FIGS.
In FIG. 9, one abnormal characteristic curve pattern (for example, the curve C in FIG. 1) obtained from a fastening abnormality other than the fastening abnormality such as excessive fastening or insufficient fastening is stored as the reference template 46. The template 46 is basically formed as a pattern on a graph with the driving stroke and the driving load as XY coordinates. Note that the driving stroke is equal to the moving length of the punch 18 of the fastening portion 2 and the moving speed thereof is substantially constant, and thus can be a function of time. Next, the main memory 26 sets the actual measurement data of the driving load data for the driving stroke (time) of the automatic punching rivet during the driving up to the completion of driving as one frame of actual measurement data.
Alternatively, it is stored in the frame memory 47 which is one area of the storage device 32. Then, as shown in FIG. 10, the difference between the data of the reference template 46 and one measured data of the frame 47 is calculated. In FIG. 10, the data of the template 46 and the data of the nth frame memory 47 are subtracted, and when there is a difference, the value of the actually measured data of the frame memory n is left as a pattern X. This pattern X
Are integrated to obtain an integration pattern 49. The magnitude of this integrated value is judged to detect whether or not there is another fastening abnormality. Further, in FIG. 11, the data of the template 46 and the data of the m-th frame memory 47 are subtracted, and when there is a difference, the value of the actual measurement data of the frame memory m is left.
It has a pattern. The pattern Y is integrated to obtain an integrated pattern 50. Then, the magnitude of the integrated value is determined to detect whether or not there is another fastening abnormality. The difference between the template data and the frame memory data may be integrated, and the different fastening abnormality may be detected based on the magnitude of the integrated value. However, when integrating as shown in FIGS. 10 and 11, there are many fastening abnormalities near the end of the driving stroke, so there is an advantage that the accuracy of detecting the fastening abnormality is improved. Further, the judgment reference value of the magnitude of the integrated value or the range thereof is previously determined based on the test data and past data. Then, the template extracts an abnormal state from the test or past data, and tabulates it as data for each type of abnormality and stores it as a database (this may be the storage device 32 of the control device 1 or the storage device of an external computer). May be obtained by After detecting the fastening abnormality, the type of the fastening abnormality is also output at the same time to issue a warning or stop the machine.

In still another method, an abnormal fastening curve (for example, the curve C in FIG. 1) is modeled, and the abnormal fastening curve data is captured as a load change per unit driving stroke or time, and is used as a template in a table. Accumulate and use the tendency of changes for each abnormal model as a template database. Then, the tendency of the load change in the actual measurement data of the automatic perforation rivet during driving is grasped. This may be done by plotting the difference between the load value for each unit driving stroke or unit time and the load value immediately before that. This difference is compared to the database of template changes. The ones in which the process of change coincides are extracted and the type of abnormality is specified at the same time.
That is, one abnormal characteristic curve pattern obtained from another fastening abnormality different from the above fastening abnormality is stored in the storage device 32 or the like as a reference pattern composed of data that changes for each predetermined driving stroke. Next, actual measurement data of the driving load with respect to the driving stroke obtained from the automatic punching rivet during driving is recorded as data that changes for each of the predetermined driving strokes. Then, the print data is compared with the data of the reference pattern, it is determined whether or not the print data is close to the reference pattern data, and a close or a match is detected as a fastening abnormality. After detecting the fastening abnormality, the type of the fastening abnormality is also output at the same time to issue a warning or stop the machine. In addition, the range of the degree of approximation, which is determined to detect the other fastening abnormality, is determined in advance based on test data and past data. The detection of this fastening abnormality can also be discriminated during driving. For example, when a singular point of the curve based on the measured data is found and the point is passed, the fastening abnormality can be determined. .

[0026]

According to the present invention, in addition to the conventional system using the normal upper limit characteristic curve and the normal lower limit characteristic curve, without modifying the fastening device, a fastening operation different from the fastening abnormality such as insufficient fastening or excessive fastening is performed. By simply adding the abnormal upper limit characteristic curve and abnormal lower limit characteristic curve created and set from the abnormal abnormality state, or based on the template based on the reference curve obtained from the above-mentioned other abnormality, the abnormality that could not be detected in the past can be detected. Can be detected.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional upper limit characteristic curve and a normal lower limit characteristic curve for detecting a fastening abnormality, and a curve indicating another fastening abnormality, of a driving stroke and a driving load of a self-piercing rivet. It is a graph.

FIG. 2 is a schematic configuration diagram of an automatic perforation type rivet fastening device.

FIG. 3 is a cross-sectional view showing a state in which the self-piercing rivet is fastened to a plurality of panels.

FIG. 4 is a block diagram of hardware of a control device of the automatic punching rivet setting device.

FIG. 5 is an automatic perforation in which a normal upper limit characteristic curve and a normal lower limit characteristic curve for detecting a fastening abnormality and another abnormal upper limit characteristic curve and an abnormal lower limit characteristic curve indicating another fastening abnormality according to the present invention are displayed. It is a graph of the driving stroke versus the driving load of the mold rivet.

FIG. 6 is a graph in which actual measurement data of a driving stroke and a driving load of a normally-fastened self-piercing rivet are plotted on the graph of FIG.

FIG. 7 is a graph in which measured data of a driving stroke and a driving load of an automatic drilling rivet fastened with an excessive fastening force is plotted on the graph of FIG.

8 is a graph in which actual measurement data of the driving stroke and the driving load of the abnormal fastening automatic drilling rivet different from the fastening abnormality of FIG. 7 are plotted on the graph of FIG.

FIG. 9 is a diagram showing a method of detecting a fastening abnormality according to another embodiment of the present invention, showing a template pattern and an actually measured pattern of a frame memory.

FIG. 10 is a diagram showing how integration is performed using the difference between the template of FIG. 9 and a frame memory.

11 is a diagram showing how integration is performed using the difference between the template of FIG. 9 and a frame memory different from that of FIG.

[Explanation of symbols]

A Normal upper limit characteristic curve B Normal lower limit characteristic curve C Characteristic curve relating to another fastening abnormality 1 Automatic piercing rivet fastening device 2 Fastening part 3 Control device 5 and 5A panel (fastened member) 6 Robot 7 Rivet feeding device 9 Monitor 11 receiver mechanism 15 C type frame 17 die 18 punch 19 motor 21 automatic punching rivet 22 head 23 leg 25 CPU (central processing unit) 26 main memory 32 memory 37 normal upper limit characteristic curve 38 normal lower limit characteristic curve 39 abnormal upper limit characteristic Curve 41 Abnormal lower limit characteristic curve 42, 43, 45 Plot value curve of actual measurement data of automatic piercing rivet 46 Reference template 47 Frame memory

Claims (10)

[Claims] 1. A self-piercing rivet consisting of a flange-shaped head and an annular leg that hangs down from the head is punched into a plurality of members to be fastened by a punch and a die to punch the leg while the leg tip is drilled. Of the self-piercing rivet in the self-piercing rivet fastening device that connects the plurality of members to be fastened to each other by the deforming and expanding legs and the head. And a normal load characteristic curve that determines the upper limit of the normal fastening range and a normal lower limit characteristic curve that determines the lower limit of the normal fastening range are displayed on the graph that displays the driving load and the XY coordinates, and the automatic drilling rivet during driving. The driving stroke and the driving load of the above are detected and plotted in the graph, and it is detected that the plotted value deviates from between the normal upper limit characteristic curve and the normal lower limit characteristic curve, and the automatic drilling rivet And a normal upper limit characteristic curve and a normal lower limit characteristic curve of the graph between the normal upper limit characteristic curve and the normal upper limit characteristic curve, the abnormal upper limit characteristic curve and abnormality Displaying the lower limit characteristic curve, the plot value of the automatic perforation rivet during driving,
A method for detecting a difference between the abnormal upper limit characteristic curve and the abnormal lower limit characteristic curve to detect the other fastening abnormality of the automatic punching rivet. 2. A self-piercing rivet consisting of a flange-shaped head and an annular leg that hangs from the head is punched into a plurality of fastened members by a punch and a die to punch the leg while the leg tip is drilled. Of the self-piercing rivet in the self-piercing rivet fastening device that connects the plurality of members to be fastened to each other by the deforming and expanding legs and the head. And a normal load characteristic curve that determines the upper limit of the normal fastening range and a normal lower limit characteristic curve that determines the lower limit of the normal fastening range are displayed on the graph that displays the driving load and the XY coordinates, and the automatic drilling rivet during driving. The driving stroke and the driving load of the above are detected and plotted in the graph, and it is detected that the plotted value deviates from between the normal upper limit characteristic curve and the normal lower limit characteristic curve, and the automatic drilling rivet A method of detecting a fastening abnormality of a grate, wherein one abnormal characteristic curve pattern obtained from a fastening abnormality different from the above-mentioned fastening abnormality is stored as a reference template, and the plot of the automatic drilling rivet during the driving. The measured data up to the end of driving obtained from the value is saved as one frame of measured data, the difference between the reference template data and the one frame of measured data is calculated, and the value based on the difference is integrated to obtain the magnitude. A method for detecting another fastening abnormality based on the above. 3. A self-piercing rivet consisting of a flange-shaped head and an annular leg that hangs down from the head is punched into a plurality of members to be fastened by a punch and a die, and the leg tip is punched while punching the leg. Of the self-piercing rivet in the self-piercing rivet fastening device that connects the plurality of members to be fastened to each other by the deforming and expanding legs and the head. And a normal load characteristic curve that determines the upper limit of the normal fastening range and a normal lower limit characteristic curve that determines the lower limit of the normal fastening range are displayed on the graph that displays the driving load and the XY coordinates, and the automatic drilling rivet during driving. The driving stroke and the driving load of the above are detected and plotted in the graph, and it is detected that the plotted value deviates from between the normal upper limit characteristic curve and the normal lower limit characteristic curve, and the automatic drilling rivet A method for detecting a fastening abnormality of a joint, wherein one abnormality characteristic curve pattern obtained from a fastening abnormality different from the above-mentioned fastening abnormality is stored as a reference pattern consisting of data that changes for each predetermined driving stroke, The measured data of the driving load with respect to the driving stroke obtained from the automatic punching rivet during driving is recorded as data that changes for each of the predetermined driving strokes, and the recorded data is compared with the data of the reference pattern. ,
The method for detecting another fastening abnormality based on the degree to which the recording data approximates the reference pattern data. 4. The method according to claim 1, wherein the another fastening abnormality is caused by the self-piercing rivet caused by a fall of the punch. 5. The method according to claim 1, wherein the another fastening abnormality is caused by insufficient hardness of the material of the self-piercing rivet. 6. An automatic piercing rivet comprising a flange-shaped head and an annular leg that hangs down from the head is punched into a plurality of members to be fastened by a punch and a die to punch the leg while the tip of the leg is pierced. Is a device for detecting a fastening abnormality of an automatic piercing rivet used in an automatic piercing rivet fastening device that connects the plurality of members to be fastened to each other by the deforming and expanding legs and the head. Therefore, the graph that displays the driving stroke and the driving load on the XY coordinates displays the normal upper limit characteristic curve that determines the upper limit of the normal fastening range and the normal lower limit characteristic curve that determines the lower limit of the normal fastening range. The driving stroke and the driving load of the self-piercing rivet in the inside are detected and plotted in the graph, and it is detected that the plotted value deviates from between the normal upper limit characteristic curve and the normal lower limit characteristic curve, and In the dynamic boring type rivet fastening abnormality detecting device, further, between the normal upper limit characteristic curve and the normal lower limit characteristic curve of the graph, an abnormal upper limit characteristic curve and an abnormal lower limit obtained from a fastening abnormality different from the above fastening abnormality. A characteristic curve is displayed, and the plotted value of the self-piercing rivet during driving is
A fastening abnormality detecting device, characterized in that it is detected between the abnormality upper limit characteristic curve and the abnormality lower limit characteristic curve to detect the other fastening abnormality of the automatic punching rivet. 7. A tip of a leg while punching the leg by driving a self-piercing rivet consisting of a flange-shaped head and an annular leg depending from the head into a plurality of members to be fastened by a punch and a die. Is a device for detecting a fastening abnormality of an automatic piercing rivet used in an automatic piercing rivet fastening device that connects the plurality of members to be fastened to each other by the deforming and expanding legs and the head. Therefore, the graph that displays the driving stroke and the driving load on the XY coordinates displays the normal upper limit characteristic curve that determines the upper limit of the normal fastening range and the normal lower limit characteristic curve that determines the lower limit of the normal fastening range. The driving stroke and the driving load of the self-piercing rivet in the inside are detected and plotted in the graph, and it is detected that the plotted value deviates from between the normal upper limit characteristic curve and the normal lower limit characteristic curve, and In a fastening abnormality detecting device for a dynamic drilling rivet, one abnormal characteristic curve pattern obtained from a fastening abnormality different from the above fastening abnormality is stored as a reference template, and the plotted value of the automatic drilling rivet during driving is stored. The measured data up to the end of driving, which is obtained from, is stored as one frame of measured data, the difference between the reference template data and the one frame of measured data is calculated, and the value based on the difference is integrated to determine its size. A fastening abnormality detecting device for detecting another fastening abnormality based on the above. 8. An automatic piercing rivet consisting of a flange-shaped head and an annular leg that hangs down from the head is punched into a plurality of members to be fastened by a punch and a die to punch the leg while tipping the leg. Is a device for detecting a fastening abnormality of an automatic piercing rivet used in an automatic piercing rivet fastening device that connects the plurality of members to be fastened to each other by the deforming and expanding legs and the head. Therefore, the graph that displays the driving stroke and the driving load on the XY coordinates displays the normal upper limit characteristic curve that determines the upper limit of the normal fastening range and the normal lower limit characteristic curve that determines the lower limit of the normal fastening range. The driving stroke and the driving load of the self-piercing rivet in the inside are detected and plotted in the graph, and it is detected that the plotted value deviates from between the normal upper limit characteristic curve and the normal lower limit characteristic curve, and In the dynamic perforation type rivet fastening abnormality detecting device, one abnormal characteristic curve pattern obtained from a fastening abnormality different from the above fastening abnormality is stored as a reference pattern consisting of data that changes for each predetermined driving stroke, Recording the actual measurement data of the driving load for the driving stroke obtained from the automatic perforation rivet during driving is recorded as data that changes for each of the predetermined driving stroke, the recording data is compared with the data of the reference pattern,
A fastening abnormality detecting device, wherein the another fastening abnormality is detected based on the degree to which the recording data approximates the reference pattern data. 9. The device according to claim 6, wherein the another fastening abnormality is caused by the automatic piercing rivet caused by a fall of the punch. 10. The device according to claim 6, wherein the another fastening abnormality is caused by insufficient hardness of the material of the self-piercing rivet.