JPS6277146A - Deciding method for caulking - Google Patents

Abstract

PURPOSE:To raise the decision accuracy for whether a caulking state is good or not, and to improve the quality of a product by comparing a value of the other with a reference value and deciding whether the caulking state is good or not, when either a caulking load or a caulking time becomes a prescribed value. CONSTITUTION:A cylinder 5 is operated, a caulking load is detected by a signal from a load cell 7, and this detection is executed continuously from the beginning of a start of a caulking operation to the end. By the operation of the cylinder 5, a caulking claw 22 abuts on a part to be caulked A'', and also, from this time point, the caulking load rises, and increases gradually. On the way of an increase of the caulking load, at the time point when it has reached the initial load, a measurement of the caulking time by a timer is started, and when it is detected that the caulking load has reached the first prescribed load, whether the first caulking load has reached the first prescribed load, whether the first caulking state is good or not is decided, based on the value of the caulking time. When the first decision is OK, the caulking load further increases, the second decision is executed, and when the second time decision is also OK, the caulking operation is further continued, and when a push rod 4 is stroked to the lower end, the caulking operation is ended.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a crimping determination method for determining whether the crimping condition is good or bad when a crimping device is used to perform crimping work, for example, to prevent loosening of a lock nut. Regarding.

(Prior art) For example, when a rotating body is attached to a rotating shaft, a nut is generally screwed onto the threaded portion of the rotating shaft after the rotating body is fitted onto the rotating shaft. As shown in Fig. 8, by using a lock nut A consisting of a hexagonal part A' and a cylindrical part A'' connected to each other, and caulking the cylindrical part ALT of the nut A after screwing onto the screw shaft B. The nut A may be prevented from loosening.

However, such lock nut crimping work is usually performed automatically using a crimping device such as that shown in Japanese Utility Model Application Publication No. 58-8532, but the crimping state cannot be managed in such a case. is done as follows.

That is, when the crimping pawl provided in the crimping device is pressed against a part to be crimped (for example, the cylindrical part of a lock nut) with a cylinder or the like and stroked, the crimping load that acts as a reaction force on the crimping pawl is detected, and this stroke is detected. Correct caulking is determined when the caulking load finally falls within the OK zone If it does not fall within the above-mentioned OK zone X as shown by curves d, e, etc., it is determined that the crimping is defective due to insufficient crimping force or crimping world. However, according to such a determination method, even items that fall within the above-mentioned OK zone X may not actually be caulked correctly. For example, if the material of the caulked part is too soft or the wall thickness is too thin, or if the caulking position is too shallow as shown by arrow a' in Fig. 8, the change in the caulking load with respect to the stroke will be If the material of the caulked part is too hard or too thick, or the caulking position is too deep as shown by arrow C' in Figure 8, In some cases, the caulking load will be as shown by curve C in Figure 7, but even in these cases, if the stroke and caulking load ultimately fall within the OK zone X, it will be determined that the caulking was done correctly. It is.

(Purpose of the Invention) The present invention is intended to deal with the above-mentioned situation when, for example, a lock nut is crimped onto a screw shaft using a crimping device.
Rather than determining whether the crimping was done correctly based only on the fact that the crimping force has finally fallen within a predetermined OK zone, we also use the change in the crimping load over time during the crimping operation as a criterion for judgment, and examine the characteristics of this change. It is determined that the caulking condition is correct only when the characteristics approximately match those obtained when the best caulking condition is obtained. The purpose of this is to improve the accuracy of determining whether the caulking condition is good or not, and to improve the quality and reliability of products that have been caulked with this type of caulking.

(Structure of the Invention) That is, in the caulking determination method according to the present invention, the caulking device is equipped in advance with a load detector for detecting the caulking load and a timer for measuring the caulking time from the start of the caulking operation,
During the caulking operation, the caulking time when the caulking load reaches a predetermined value is compared with a predetermined reference value, or the caulking load when the caulking time reaches a predetermined time is compared with a predetermined reference value, and The present invention is characterized in that the quality of the crimping condition is determined based on whether the crimping time or the crimping load, which is compared with the IJt standard value, is within a predetermined allowable range.

According to such a method, it is determined that caulking has been performed correctly only when the temporal change characteristics of the caulking load during the caulking operation match or are close to the characteristics when the best caulking condition is obtained. Therefore, cases where the caulking load shows an abnormal change over time due to inappropriate material, wall thickness, caulking position, etc. of the caulked portion are excluded as defective caulking.

(Effects of the Invention) As described above, according to the caulking determination method of the present invention, the quality of the caulking state can be determined with higher accuracy,
If the material, wall thickness, or crimping point IU of the crimped part is not appropriate, it will be definitely rejected as a crimping defect, and this will improve the quality and reliability of products that are crimped with this type of material. will be done.

<Example> Hereinafter, an example of the caulking determination method of the present invention will be described.

First, the caulking device used in this embodiment will be explained. As shown in FIGS. 1 and 2, this caulking device 1
has a main body 3 that is movable up and down together with the base 2, and a bushing rod 4 is supported within the main body 3 so as to be slidable up and down. Cylinder 5 is visible. Here, a j1 connecting member 6 is fixed to the lower end of the piston rod 5a of the cylinder 5, and the piston rod 5a and the bushing rod 4 are connected via this connecting member 6. A load cell 7 is interposed between the bushing rod 4 and the bushing rod 4 to detect a reaction force (crimping load) when the bushing rod 4 is pressed downward by the cylinder 5. Further, a switch operating member 9 is attached to the side surface of the connecting member 6 via a bracket 8, and the upper and lower large diameter portions 9a and 9b of the member 9 are attached to the outer surface of the main body 3. 1. By abutting contactors 10a and 11a of the second limit switches 10 and 11, respectively, the upper moving end and lower eight ends of the cylinder 5 or bushing rod 4 are detected.

On the other hand, a pair of bearing members 12.1 are provided at the lower end of the main body 3.
2, the center part of the L-shaped arm 13 is rotatably supported around a support shaft 14, and a support plate 15 is suspended from the lower part of the main body 3, and a caulking lever is attached to the support plate 15. 16
A central portion of the support shaft 17 is rotatably supported around a support shaft 17. One end 13a of the above-mentioned die arm 13 is located below the lower end of the bushing rod 4, and
An engagement shaft 18 provided at the other end 13b of the bifurcated arm 13 is engaged with a notch 16a formed at the upper end of the caulking lever 16, so that it can be moved from the position shown in the figure. When the bushing rod 4 moves downward, the wedge-shaped arm 13 rotates in the X direction, and the caulking lever 16 accordingly rotates in the Y direction. Here, springs 19 and 19 that urge the L-shaped arm 13 and the crimping lever 16 in the anti-X and anti-y directions are installed between the engagement shaft 18 and the support plate 15, and the support plate 15
There is a stopper 20 that restricts the rotation of the caulking lever 16 in the counter-y direction by the spring 19, 19 at a predetermined initial position.
is provided.

A receiver member 21 is provided at the lower end of the support plate 15, and a crimping pawl 22 is fixed to the lower end of the crimping lever 16 so as to face the receiver 21. As such, a lock nut A screwed onto a screw shaft B is set between the caulking pawl 22 and the member 21 as a caulked member.

As shown in FIG. 3, the crimping device 1 receives a load signal S1 outputted from the load cell 7 and a time signal S2 outputted from a separately provided timer 23. A determination circuit 24 is provided which determines whether the caulking condition is good or not based on the signals S1 and S2.

Next, a procedure for caulking work using the caulking device 1 will be explained.

First, as shown in FIGS. 1 and 2, with the cylinder 5 or the bushing rod 4 in the caulking device @1 positioned at the upper moving end, the lower end of the support plate 15 is connected to the member 21 and the lower end of the caulking lever 16. The caulked part (cylindrical part) A'' of the lock nut A screwed onto the screw shaft B is set between the pawl 22 and the bushing rod 4 via the connecting member 6 by operating the cylinder 5. At this time, the wedge-shaped arm 13 and the caulking lever 16 are moved downward, respectively.
The lever 16 is rotated in the y direction so that the crimping pawl 22 at the lower end of the lever 16
However, the receiver moves to the member 21 side, and the pawl 22 is pressed with strong force against the crimped portion A+7 of the lock nut.

As a result, as shown in FIG. 4, the part where the crimping pawl 22 is pressed in the part A I+ to which the lock nut is crimped is deformed toward the screw shaft B, and the lock nut A is crimped against the screw shaft B. Nut A will be prevented from loosening. Here, if a notch groove B' is provided in the screw shaft B and the deformed part A''' of the caulked part A'' is bitten into the groove B', the lock nut A can be loosened more reliably. It will be stopped.

However, while the caulking pawl 22 moves toward the member 21 side and caulks the caulked portion A'' of the lock nut A, the caulking load is detected by the load cell 7 as a reaction force from the bushing rod 4 toward the cylinder 5 side. Based on the change in the caulking load and the caulking time measured by the timer 23 shown in FIG. 3, the determination circuit 24 determines whether the caulking condition is good or bad.

This determination operation is performed as follows according to the flowchart shown in FIG. That is, first, in step P1, the caulking operation is started by the operation of the cylinder 5, and
The caulking load [is detected based on one word S1 from the load cell 7. Detection of this caulking load is carried out continuously from the beginning of the caulking operation until the end of the operation. Then, due to the downward movement of the bushing rod 4 due to the operation of the cylinder 5, the crimping pawl 22 comes into contact with the crimped portion A'' due to the rotation of the arm 13 and the crimping lever 16, and from this point on, the crimping load f rises. Thereafter, as the crimping claw 22 moves over time, the crimping load f gradually increases as shown in FIG. 6.

During the increase in the caulking load if, when the load mf reaches a predetermined initial load (an extremely small value) Fo, the timer 23 starts measuring the caulking time t (steps P2 and P3). Then, when it is detected that the caulking load Mf further increases and reaches the first predetermined load F1, the quality of the first caulking condition is determined based on the value of the caulking time t measured by the timer 23. (Steps P4 and P5). In other words, the caulking time t required for the caulking load f to increase from the initial load FO to the first predetermined load F1 is relative to the known time (first reference time) T+ required when caulking is performed under the best conditions. If it is within a certain tolerance range △T1), the first judgment is O.
If the result is outside this allowable range, it is determined to be NG at this point (step P6).

Also, if it is judged OK in this first judgment,
When the caulking load "increases further and reaches the second predetermined load ff1Fz, a second determination is performed. Step P7
．． P8). In this judgment as well, the initial 7. The caulking time required to increase from y city Fo to the second predetermined load 1-2 [is the known time (second reference time) T required for caulking to be performed in the best condition.
2 within a certain tolerance range (±△T2>, O
K, and if it deviates from this allowable range, it is determined to be NG at this point (step PG).

In this way, if J3 is determined to be OK in both of the two judgments made during the crimping operation, the crimping operation is continued, but the piston rod 5 of Schilling 5
When the bushing rod a or the bushing rod 4 strokes to the lower moving end, the second limit switch 11 is turned on by the switch operating member 9 (not shown in Fig. 1.2), and the operation of the cylinder 5 is stopped. Movement of the caulking claw 22 6
The crimping operation is stopped and the crimping operation is completed. Then, at the end of this caulking operation, the final value (maximum value) of the caulking load is detected, and it is determined whether this final value is within a certain tolerance range (±ΔF) with respect to the predetermined target caulking load F. is determined (Step P9゜Plo). Then, if the final value of the caulking load is within the above-mentioned allowable range, the caulking state is finally determined to be OK (swip Pt+), and if it deviates from the above-mentioned allowable range. If so, it is determined as NG by this final determination (step P6).

As described above, according to this method, the quality of the crimping condition is determined not only by the value of the final crimping load when the crimping pawl 22 moves a predetermined stroke, but also by the change in the crimping load over time during the crimping operation. It turns out. Therefore, if the caulking load shows a change over time as shown by curve Q in Fig. 6, for example, because the 8' BL of the caulked part is soft or thin, or because the caulking position is too shallow, etc. In addition, if the caulked cart shows changes over time such as curves due to the material of the caulked part being too hard or too thick, or the caulking position being too deep,
Even if the R Hiiragi caulking load is an OK value, it will be determined that the caulking is defective. As a result, the quality of the caulking condition can be accurately determined, and products with defective caulking can be reliably eliminated.

In the above embodiments, in order to determine the change over time in the caulking load, the method is to compare the caulking time [when the load f becomes a predetermined load [:1, F2] with the reference times T1, T2. However, on the contrary, changes over time in the caulking load may be determined by comparing the caulking load when the caulking time reaches a predetermined time with a reference load.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams used in embodiments of the present invention. A partially cutaway side view and a front view of the crimping device, FIG. 3 is a block diagram showing the groove configuration of the crimping determination means in the crimping device, FIG. 4 is an enlarged plan view showing the crimping state by the crimping device, and FIG. FIG. 5 is a flowchart showing the caulking determination procedure of this embodiment, and FIG. 6 is a diagram showing the change in caulking load over time, showing the determination method. Further, FIG. 7 is a J stroke-caulking load characteristic diagram showing a conventional determination method, and FIG. 8 is a side view showing an example of a crimp portion. 1... Crimping device, 7... Load detector (load wall), 23... Timer.

Claims (1)

[Claims] (1) The caulking device is equipped with a load detector that detects the caulking load and a timer that measures the caulking time from the start of the caulking operation, and during the caulking operation, the caulking load detected by the load detector and the timer are A caulking determination method, characterized in that when one of the caulking times measured by the method reaches a predetermined value, the other value is compared with a reference value to determine whether the caulking condition is good or bad.