JPH0159054B2 - - Google Patents

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 the figure, using a lock nut A in which a cylindrical part A'' is connected to a hexagonal part A',
After screwing onto the screw shaft B, the nut A may be prevented from loosening by caulking the cylindrical portion A'' of the nut A.

However, it is customary to swage such lock nuts automatically using a swage device such as that shown in Japanese Utility Model Application Publication No. 58-8532, but the swage condition cannot be managed in such a case. is done as follows.

That is, the crimping load acting as a reaction force on the crimping pawl 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 is detected, Correct caulking is achieved when this stroke and caulking load finally fall within the OK zone If it is not within the OK zone X as shown by curves d, e, etc., it is determined that the crimping is defective due to insufficient crimping force or amount. However, according to such a determination method, even items that fit 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 As shown by curve a in the figure,
Conversely, if the material of the caulked part is too hard or too thick, or if the caulking position is too deep as shown by arrow c' in Figure 8, the caulking load will be lower than that shown in Figure 7. However, even in these cases, the stroke and caulking load are ultimately
If it falls within the OK zone X, it is determined that it has been crimped correctly.

(Object of the Invention) The present invention deals 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 caulking has been done correctly based only on the fact that it falls within the zone, we also use the change in the caulking load over time during the caulking operation as a criterion for judgment, and if the characteristics of this change result in the best caulking condition. It is determined that the caulking has been done correctly only when the characteristics approximately match. 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, the caulking determination method according to the present invention includes a load detector that detects a caulking load on a caulking device in advance;
A timer is provided to measure the caulking time from the start of the caulking operation, and during the caulking operation, when the caulking load reaches a predetermined value, the caulking time is compared with a predetermined reference value, or when the caulking time reaches the predetermined value. In addition to comparing the caulking load at the specified time with a predetermined reference value, the quality of the caulking condition is determined by whether or not the caulking time or caulking load compared with the reference value is within a predetermined allowable range. It is characterized by making a judgment. According to this 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 or wall thickness of the caulked portion, or inappropriate caulking device, etc., will be 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 condition can be judged with higher accuracy, and the material, wall thickness, caulking position, etc. of the caulked part are determined appropriately. Items that do not meet this criteria will be reliably rejected as defective crimping, thereby improving the quality and reliability of products to which this type of crimping is applied.

(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 can move up and down together with a base 2, A push rod 4 is supported so as to be vertically slidable, and a cylinder 5 for moving the push rod 4 up and down is provided at the upper part of the main body 3. here,
A 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 push rod 4 are connected via this connecting member 6, and there is no space between the connecting member 6 and the push rod 4. A load cell 7 is interposed to detect the reaction force (crimping load) when the push 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, 9b of the member 9 are attached to the outer surface of the main body 3. The upper and lower moving ends of the cylinder 5 or push rod 4 are detected by contacting the contactors 10a and 11a of the second limit switches 10 and 11, respectively.

On the other hand, the center portion of an L-shaped arm 13 is rotatably supported at the lower end of the main body 3 via a pair of bearing members 12, 12, and the lower end of the main body 3 is rotatably supported at the lower end of the main body 3. A support plate 15 is provided vertically, and the center portion of the caulking lever 16 is attached to a support shaft 17 on the support plate 15.
It is rotatably supported around the One end 13a of the L-shaped arm 13 is located below the lower end of the push 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. pushyrod 4
When the L-shaped arm 13 moves downward, the L-shaped arm 13 rotates in the x direction, and the crimping lever 16 rotates in the y direction accordingly. Here, springs 19, 19 that bias the L-shaped arm 13 and the caulking lever 16 in the anti-x and anti-y directions are connected to the engagement shaft 1.
8 and a support plate 15, and the support plate 15 is provided with a stopper 20 for restricting rotation of the caulking lever 16 in the anti-y direction by the springs 19, 19 at a predetermined initial position. There is.

A receiving member 21 is provided at the lower end of the support plate 15, and a crimping lever 16 is provided.
A caulking pawl 22 is fixed to the lower end of the housing so as to face the receiving member 21, and as shown in the figure, a caulking pawl 22 is screwed onto the screw shaft B as a caulking member between the caulking pawl 22 and the receiving member 21. Locknut A is now set.

Incidentally, as shown in FIG. 3, this caulking device 1 receives a load signal S ₁ output from the load cell 7.
and a time signal S ₂ output from a separately provided timer 23, and a determination circuit 24 which determines whether the crimping condition is good or not based on these signals S ₁ and S ₂ is provided.

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 push rod 4 of the crimping device 1 positioned at the upper moving end, the receiving member 21 at the lower end of the support plate 15 and the crimping pawl 2 at the lower end of the crimping lever 16 are placed.
Lock nut A screwed onto screw shaft B between
Set the caulked part (cylindrical part) A″ of.Next,
By operating the cylinder 5, the push rod 4 is moved downward via the connecting member 6. At this time, the L-shaped arm 13 and the crimping lever 16 rotate in the x and y directions, and the crimping claw 22 at the lower end of the lever 16 moves toward the receiving member 21, and the claw 22
is pressed against the caulked portion A'' of the lock nut A with a strong force. As a result, the portion of the caulked portion A'' of the lock nut A where the caulking pawl 22 is pressed is pushed toward the screw shaft B side, as shown in Fig. 4. The lock nut A is deformed, and the lock nut A is caulked against the screw shaft B to prevent the nut A 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 inserted into the groove B', the lock nut A can be more securely prevented from loosening. That will happen.

However, while the caulking pawl 22 moves toward the receiving member 21 and caulks the caulked portion A'' of the lock nut A, the caulking load is applied to the push rod 4.
is detected by the load cell 7 as a reaction force toward the cylinder 5, and based on this change in the caulking load and the caulking time measured by the timer 23 shown in FIG. Determine.

This determination operation is performed as follows according to the flowchart shown in FIG. That is, first step
At _P1 , the caulking operation is started by the operation of the cylinder 5, and the caulking load f is detected based on the signal _S1 from the load cell 7. Detection of the caulking load f is continuously performed from the beginning of the caulking operation until the end of the operation. Then, due to the downward movement of the push rod 4 due to the operation of the cylinder 5 or the rotation of the L-shaped arm 13 and the caulking lever 16, the caulking pawl 22 comes into contact with the caulked portion A'', and from this point on, the caulking load f starts to rise. Thereafter, as the crimping claw 22 moves over time, the crimping load f gradually increases as shown in FIG.

However, during the increase of the caulking load f, when the load f reaches a predetermined initial load (an extremely small value) F ₀ , the timer 23 starts measuring the caulking time t (steps P ₂ and P ₃ ). When it is detected that the caulking load f has further increased to reach 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. is determined (step _P4 ,
_P5 ). In other words, the crimping time t required for the crimping load f to increase from the initial load F ₀ to the first predetermined load F ₁ is the known time (first reference time) T required for crimping to be performed under the best conditions. If it is within _{a certain tolerance range (±ΔT 1 )} with respect to _P6 ).

If the first judgment is OK, the second judgment is made when the caulking load f further increases and reaches the second predetermined load _F2 (steps _P7 and P7). ₈ ). In this judgment as well, the caulking load f changes from the initial load _F0 to the second predetermined load.
The caulking time t required to increase to F ₂ is within a certain tolerance range (±ΔT ₂ ) with respect to the known time (second standard time) T ₂ required for caulking under the best conditions. At certain times, it is determined to be OK, and when it deviates from this allowable range, at this point it is determined to be NG (Step P ₆ ).

In this way, 2
If both times are determined to be OK, the caulking operation continues, but cylinder 5
When the piston rod 5a or push rod 4 strokes to the lower moving end, the second limit switch 11 is turned on by the switch operating member 9 shown in FIGS. 1 and 2, and the operation of the cylinder 5 is stopped. The movement of 22 is also stopped, and the caulking operation is completed. Then, at the end of this caulking operation, the final value (maximum value) of the caulking load f is detected, and whether or not this final value is within a certain tolerance range (±ΔF) with respect to the predetermined target caulking load F is detected. (Step P ₉ ,
_P10 ). If the final value of the caulking load falls within the above tolerance range, the final caulking condition is OK.
(switch P ₁₁ ), and when it deviates from the above-mentioned allowable range, it is determined as NG by this final determination. (Step P ₆ ).

As described above, according to this method, the caulking nail 2
The quality of the crimping condition is determined not only by the value of the final crimping load when 2 moves by a predetermined stroke, but also by the change in the crimping load over time during the crimping operation. Therefore, for example, because the material of the caulked part is soft or thin, or because the caulking position is too shallow, the caulking load shows a change over time as shown by curve g in Fig. 6. If the caulking load changes over time as shown by curve h due to reasons such as the material of the caulked part being too hard or too thick, or the caulking position being too deep, the final Even if the 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 addition, in the above embodiment, in order to determine the change over time in the caulking load f, the load f is a predetermined load.
The caulking time t when F ₁ and F ₂ are reached is the reference time T ₁ ,
The method of comparison with T ₂ was used, but on the contrary, the change over time in the caulking load was determined by comparing the caulking load when the caulking time reached a predetermined time with the reference load. Good too.

[Brief explanation of drawings]

1 and 2 are a partially cutaway side view and a front view of a crimping device used in an embodiment of the present invention, FIG. 3 is a block diagram showing the configuration of a crimping determination means in the crimping device, and FIG. FIG. 5 is an enlarged plan view showing the crimping state by the crimping device; FIG. 5 is a flowchart showing the crimping determination procedure according to the embodiment of the present invention;
The figure is a diagram showing how the caulking load changes over time, showing the determination method. Further, FIG. 7 is a stroke-caulking load characteristic diagram showing a conventional determination method, and FIG. 8 is a side view showing an example of a member to be caulked. 1... crimping device, 7... load detector (load cell), 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.