JP2019089085A - Method for determining quality of friction joint - Google Patents

Abstract

To provide a method for determining quality of joint strength that can accurately determine friction joint based on an actual joint state without using destructive inspection.SOLUTION: A quality determination method includes: a step 1 of determining quality of joint strength between joint members at friction joint and of performing determination using a heat input speed at friction joint; a step 2 of performing determination using friction upset speed; and a step 3 of performing determination using whole upset margin. The quality determination method performs determination by adding at least one of the step 2 and the step 3 to the step 1.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method of determining the quality of bonding strength in friction bonding.

In general, in friction bonding, bonding is performed by a friction process and an upset process.
In the friction step, first, one joint member is rotated and the other joint member is brought into contact without being rotated. At this time, a preheating pressure is applied to the contact surfaces of the two bonding members by the pressing means. Then, when frictional pressure is applied to the contact surfaces of the two bonding members by the pressing means at a predetermined timing after a predetermined period has elapsed, the temperature of the bonding interface is raised by the frictional heat, and a high temperature layer is formed.
That is, since the bonding interface between the bonding members is softened, a slippage occurs at a certain timing.
In the upset process, after the friction process, the upset pressure is applied while rapidly stopping the rotation. Then, the amount of change in the amount of misalignment increases, and when held for a certain period of time, the bonding member is subjected to solid phase bonding under high temperature and high pressure.
Patent Document 1 is disclosed as an example of a method of determining the quality of the bonding strength with respect to a bonding portion by such bonding. In Patent Document 1, the amount of frictional heat generation is calculated from the torque and the number of revolutions of the main shaft during bonding, and the amount of frictional heat generation of a good bonding product is compared and determined as a reference value.

JP-A-3-32480

However, in the determination method of Patent Document 1, the calorific value of the joint is calculated using the torque and rotational speed of the spindle, the calorific value is compared with the standard value of the non-defective product, and the deviation is the standard value of the non-defective product. The non-defective item is judged in comparison with.
By the way, in general, it is necessary to consider the heat input time in which the heat generation amount is input to the joining member in the friction bonding, and even if the heat generation amount is the same, if the heat input time (time taken for the friction process) is different, Judgment of bonding strength differs.

  Therefore, in the conventional determination method, it may not be possible to accurately determine the bonding strength along the actual bonding state. That is, there is a possibility that a joined product which does not have sufficient bonding strength may be determined as a non-defective product.

  Also, in order to determine the joint strength, there is a method of performing a destructive inspection after joining and measuring the joint strength. With this method, although it is possible to judge the joint strength as a sampling inspection, There was a risk that the judgment could not be made precisely.

  Furthermore, in recent years, there is a demand to increase the certainty of bonding strength to a processed product, and at a processing site of friction bonding, it is required to perform high-quality judgment of bonding strength without using a destructive inspection.

  Therefore, an object of the present invention is to provide a method of judging the quality of bonding strength which can be accurately determined based on an actual bonding state without using a destructive inspection in friction bonding.

  According to the present invention, the method is a quality determination method, which uses step 1 of determining the quality of bonding strength between bonding members at the time of friction bonding and using heat input speed at the time of friction bonding; A bonding strength determination method is provided, which includes a step 2 of determining and a step 3 of determining using a total deviation, and determining by adding at least one of step 2 and step 3 to step 1 Ru.

  Hereinafter, various embodiments of the present invention will be illustrated. The embodiments shown below can be combined with one another.

Preferably, the heat input rate is calculated by (heat input amount / cross-sectional area of bonding surface) / heat input time.
Preferably, the heat input is calculated from the motor power value of the friction process.
Preferably, the calculated value of the heat input speed falls within a predetermined reference range value, and at least one of the friction deviation speed and the calculated value of the total deviation falls within a predetermined reference range value. It is judged as non-defective when there is.
Preferably, the result of the bonding strength is displayed in the vicinity of the friction bonding apparatus to immediately determine the quality of the bonding strength.

  According to the present invention, the present invention can provide a method of determining the quality of bonding strength which can be accurately determined based on an actual bonding state without using a destructive inspection in friction bonding.

It is the figure which showed the outline | summary of the friction bonding apparatus used for the friction bonding method in one Embodiment of this invention. It is a flowchart explaining the quality determination method of joint strength. It is the graph which showed the specific example of heat input speed, friction deviation speed, and joint strength.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

  FIG. 1 is a schematic view of a friction bonding apparatus used in a friction bonding method according to an embodiment of the present invention. In addition, the friction bonding apparatus shown here is only an example, and the configuration thereof is not particularly limited as long as the friction bonding method in the present embodiment can be performed.

  As shown in FIG. 1, the friction bonding apparatus 1 is provided with a main shaft 3 that can be rotated by a motor 2. The main spindle 3 is provided with a gripping tool 4 for gripping the joining member A.

  In addition, a pedestal 5 is provided to which a holding tool 4 for holding a bonding member B installed opposite to the main shaft 3 is fixed, and the pedestal 5 is slidable coaxially with the main shaft 3. By being pressed, the bonding member B fixed to the rotating bonding member A is provided to be pressed.

  In the present embodiment, the bonding members A and B have a hollow cylindrical shape, but the shape of the bonding members is not limited to this, and friction may be applied to a solid cylindrical shape or a bonding member having a different cross section. What is necessary is just what can be joined.

  The motor 2 is provided with a current detector and a rotation detector (not shown), and can detect the current value, the rotation speed, the rotation direction, and the like of the motor 2. In addition, a control device 7 is provided which controls the operation of the friction bonding apparatus 1 such as the rotation of the main shaft 3 and the sliding of the pedestal 5.

  The control device 7 is previously determined based on command means for performing drive control of the motor 2 and the pressing means 6, storage means for storing data of bonding conditions and measurement values during bonding, and data stored by the storage means. It has the calculating means which calculates | requires a calculated value using the calculation formula, and the determination means which determines the quality of joining strength from the stored data and the calculated value.

When friction bonding is performed, bonding conditions to be described later are set in advance, and bonding is performed in accordance with the conditions.
In the present embodiment, as the joining conditions, the shape of the joining member (the cross-sectional area of the joining surface, the material, etc.), the rotational speed of the main shaft 3, the frictional pressure, the frictional time, the frictional margin, the upset pressure, and the upset time are used. In addition, according to joining object, you may select joining conditions suitably not only in this.

  Here, the friction pressure is the force applied in the friction process, the friction time is the time of the friction process, the friction shift is the shift in the friction process, the upset pressure is the force applied after rotation is stopped, and the upset time is the time of the upset process .

Now, the procedure for carrying out the friction bonding in the present invention will be described.
First, the friction bonding is performed a plurality of times in advance, and under the bonding conditions, the current value of the motor 2 per unit time from the time of the friction process to the time of the upsetting process, the friction margin, the heat input time, the friction shift speed, The actual measured values of all the approach costs are stored in the storage means as bonding data.
Here, the total approach cost is the approach cost at the end of the upset process, and the friction shift speed is the total approach cost divided by the heat input time.

  Further, a destructive inspection is performed after the friction bonding to measure the bonding strength, and the bonding strength data is stored in the storage means as bonding strength data.

Using these bonding data and bonding strength data, the heat input rate and the bonding strength at each value of the friction shift speed are confirmed.
Then, the required strength is set as the bonding strength required for the joined parts, and the one having the bonding strength satisfying the required strength which is equal to or greater than the set required strength is regarded as a non-defective product. The standard range value of is defined and set as the standard range value which becomes each non-defective item. The heat input rate is calculated in consideration of the heat input time at which the heat input is received.

A concrete graph of this is shown in FIG.
FIG. 3 is a graph showing specific examples of the heat input speed, the friction shift speed, and the bonding strength.

This graph is a graph in which data is plotted with the heat input speed on the vertical axis and the friction shift speed on the horizontal axis. It is shown on the graph whether this plot is above the necessary strength or not, that is, whether it is a good product or a defective product.
In FIG. 3, the plot is indicated by ◇ in the case of the non-defective product and by ◆ in the case of the defective product.

Based on this, the standard range value which becomes each non-defective item of heat input speed and friction deviation speed was set as follows.
<< Reference range value of heat input speed >>
14 ≦ heat input speed ≦ 17.5
<< Reference range value of friction shift speed >>
0.2 ≦ friction speed ≦ 1.0

  In addition, in order to check whether the measured value of the total deviation is a good product or a defective product, a reference range value is set in which the total deviation is a good product. This confirms that the dimension of the overall length of the joined product after joining is within the tolerance of the required dimension. A reference range value to be a non-defective item of the required dimension is set in advance, and the measurement value of the total deviation after bonding and the reference range value to be a non-defective item of the dimension are compared to determine whether it is non-defective or defective.

  After these preparations are made in advance, friction bonding is performed. The current value of the motor 2 per unit time from the time of the friction process to the time of the upset process and the approach amount are measured, and bonding is performed while storing data in the storage means.

  When performing the quality determination of the bonding strength of friction bonding, the transition area of the bonding surface of the bonding member measured in advance stored in the storage means after the completion of bonding, the transition of the current value of the motor 2, and the heat input The heat input rate, the friction shift speed, and the total approach cost are calculated from the time and the approach cost using calculation means.

In the present invention, the heat input rate is determined by the heat input / the cross sectional area of the bonding surface of the bonding member / the heat input time. Also, the friction shift speed can be obtained by the total shift cost / heat input time.
The heat input is the amount of heat applied to the joint surface of the friction process, and in the present invention, it is calculated from the motor power value of the friction process.

The actual calculation formula is shown below.
(1) Heat input rate = ΣI × V × δt / S / t
(I: motor current value, V: motor voltage value, δt: sampling period, S: cross-sectional area of bonding surface of bonding member, t: heat input time)

(2) Friction shift speed = L / t
(L: Total cost, t: Heat input time)

In the judgment of the joint strength, the judgment of the joint strength is carried out using the heat input rate calculated by the calculation means, the friction shift speed, and the total approach margin.
Next, with reference to the flowchart shown in FIG. 2, the method of determining the bond strength in the present embodiment will be described.

  First, quality determination of the heat input rate is performed by the determination means (step S1). Next, the judgment of the friction deviation speed is made (step S2). Finally, a pass / fail judgment of the total cost is made (step S3). At that time, the quality determination is performed on each of the three elements.

In step S1, it is checked whether the calculated value of the heat input rate calculated by the calculation means falls within a reference range value which is a good product of the heat input rate set in advance.
If the calculated value of the heat input rate is within the reference range value of the heat input rate set in advance using the determination means, the process proceeds to step S2; Step S5).

In the next step S2, it is checked whether the calculated value of the friction deviation speed calculated by the calculation means falls within a reference range value which is a good product of the friction deviation speed set in advance.
If the calculated value of the friction shift speed is within the reference range value which is a good product of the friction shift speed set in advance using the determination means, the process proceeds to step S3. Step S5).

In step S3, it is checked whether the measured value of the measured all-around allowance is within the reference range value which becomes a non-defective item of the all-around allowance set in advance.
If the measured value of the all-around margin is within the standard range value which becomes the non-defective item of the all-around margin set in advance using the determination means, it is determined as the non-performing item (step S4). It is determined that (step S5).
This is the end of the quality determination.

  That is, the case where all of the three factors, ie, the heat input speed, the friction shift speed, and the total shift cost, fall within the respective reference range values is determined as a non-defective product, which is the most accurate determination method. .

  However, although the determination method can be changed variously according to the customer's request etc., it is better to add at least one of step S2 and step S3 to step S1 for the determination to clear the minimum bonding strength accuracy.

  For example, if the heat input speed and the friction shift speed in step S1 and step S2 are respectively within the reference range value, it may be determined as a non-defective product, or the heat input speed and total deviation margin in step S1 and step S3. If each falls within the reference range value, it may be determined as a non-defective product.

  As described above, the present invention focuses on the heat input time in which the heat input is received together with the heat input as a factor in the judgment when determining whether the bonding strength is good or bad, and is calculated based on the heat input and the heat input time. Good or bad judgment is performed using the heat input rate.

  As described above, since the heat input amount and the heat input time, which are important factors in the process of friction bonding, are used to judge the quality of the bonding strength, the judgment conforms to the actual bonding state and can be judged accurately.

  Therefore, in friction bonding, it is possible to prevent with a high probability that a defective product is shipped as a product, which can also contribute to the improvement of product reliability.

  In addition, by providing display means 8 for displaying the result of the quality determination in the vicinity of the friction bonding apparatus 1, the determination result may be notified to the operator. As a result, the operator can distinguish between good and bad products at an early stage. The display means 8 may be, for example, a monitor for displaying a numerical value or a defect warning or the like, a lamp or a buzzer for notifying an operator when a defect is generated.

  The term “in the vicinity” may be incorporated in the friction bonding apparatus 1 or a place where the apparatus can be installed slightly away from the friction bonding apparatus 1.

While embodiments of the present invention have been described, this is presented as an example and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. This embodiment is included in the scope and the gist of the invention, and is included in the invention described in the claims and the equivalent scope thereof.

DESCRIPTION OF SYMBOLS 1 friction joining apparatus 2 motor 3 main axis | shaft 4 holding | grip 5 base 6 press means 7 control apparatus 8 display means A, B joining member

Claims (5)

It is a pass / fail judgment method which judges pass / fail of joining strength between joining members at the time of friction joining,
Step 1 of determining using heat input rate at the time of friction bonding;
Step 2 of determining using friction deviation speed;
Step 3 in which the determination is made using the total cost
Have
A bonding strength determination method, wherein at least one of the step 2 and the step 3 is added to the step 1 to make a decision. In the method for determining the bonding strength according to claim 1,
The quality judgment method of the joint strength in which the said heat input rate is calculated by (cross sectional area of heat input / joint surface) / heat input time. In the method for determining the bond strength according to claim 2,
The method for determining the quality of bonding strength, wherein the amount of heat input is calculated from the motor power value of the friction process. In the method for determining the bonding strength according to claim 1,
When the calculated value of the heat input speed falls within a predetermined reference range value, and at least one of the friction shift speed and the calculated value of the total approach margin falls within a predetermined reference range value A method of judging whether the joint strength is good or not. In the method for determining the bonding strength according to claim 1,
A bonding strength pass / fail judgment method for displaying the bond strength result in the vicinity of the friction bonding apparatus and immediately judging the bond strength.

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