JPS6350116B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention abuts the joined parts of joined members against each other, rubs them against each other, melts the joined parts, and then stops the frictional movement and cools and solidifies the fused parts. The present invention relates to a method and apparatus for determining the quality of joined products by so-called friction welding, in which joined members are joined together.

(Conventional technology) Conventionally, as for friction welding,
Publication No. 41-21125, Japanese Patent Publication No. 44-28984, etc. are disclosed.

(Problems to be Solved by the Invention) Friction welding has high joining performance and excellent productivity, so it is widely used for joining metals and plastics.

In addition, in order to improve the joining performance of welded products,
Conventionally, various relationships among friction conditions such as friction pressure, friction speed, and time required for friction have been determined.

It has been thought that it is possible to completely control these frictional speeds, pressures, etc. to a certain extent, and that it is possible to maintain a constant bonding strength of welded products by controlling them to ideal conditions.

However, even with well-scrutinized joining conditions, so-called defective products with low joining strength often occur.Furthermore, conventionally, the joining performance of friction welded products could only be confirmed through destructive testing. There was a problem that complete quality assurance was not possible.

Therefore, in the past, a welding device with higher precision was used to obtain a bonding strength commensurate with the condition setting, and by selecting welding conditions with sufficient margin, the production of defective products was avoided.

It would be particularly desirable if a pass/fail judgment method or a pass/fail judgment device capable of determining the quality of a joined product during welding work could be realized, since it would be possible to significantly improve the reliability of welding without the need for inspection.

(Means for Solving the Problems) Therefore, in view of the above problems, the present inventors
As a result of various experiments and research, as well as careful consideration, we discovered that the stopping acceleration of frictional motion, which was not marked at all under conventional welding conditions, was a major factor.

The present invention has been made based on this discovery, and in order to meet the above-mentioned needs, it is an object of the present invention to provide a method and apparatus that can reliably determine the quality of a joined product during welding work.

In other words, in a welding method in which the joined parts of joined members are butted against each other, rubbed against each other, the joined parts are melted, the frictional motion is stopped, the fused parts are cooled and solidified, and the joined members are joined. Perform welding under the following conditions, determine the relationship between the maximum stopping acceleration at the time of stopping frictional motion and the joint strength,
Based on this relationship, a standard value corresponding to the required joint strength is determined in advance, and when performing friction welding, the maximum stopping acceleration when the frictional motion stops is measured, and if the value is smaller than the above standard value, the welded product is A method for determining the quality of a joined product by friction welding to determine whether it is defective, a means for measuring the stopping acceleration when the frictional movement stops, and a means for measuring the measured value in a device that butts the joined parts of joined members and rubs them against each other to join them. Friction welding characterized by having a means for displaying or a means for comparing the measured value with a preset reference value to indicate whether the welded product is good or bad, or a means for sorting the welded product into good or defective products. This is a device for determining the quality of bonded products.

(Effects of the Invention) According to the present invention, it is possible to determine the quality of a joined product by examining the stopping acceleration of frictional motion, which has not been marked at all in the past.

Therefore, it is possible to determine whether the joint is good or bad during the welding process, which was previously impossible, making it possible to easily improve the quality of the joined product and to reduce costs by eliminating the inspection process. It has characteristics.

(Example) The embodiments shown in the drawings will be described below.

FIG. 1 is a basic configuration diagram of a conventionally known friction welding device.

In FIG. 1, 7a and 7b are joining members,
Each is held by jigs 6a and 6b. The gripping tool 6a on the driving side is fixed to the main shaft 4, and is driven by the motor 1 through the brake 3 and the clutch 2, and is moved by the arrow 5.
It is designed to rotate in the direction of.

On the other hand, the gripper 6b on the fixed side does not rotate, but is pressurized by the cylinder 8 in the direction of the arrow 9.

In such a welding device, the joining members 7a, 7b
are rotated relative to each other while pressurizing each other, and after the joint surfaces are rubbed against each other and melted, the frictional movement is stopped by the brake 3, and the molten portion is cooled and solidified, so that welding can be performed.

FIG. 2 is a basic configuration diagram of another conventionally known type of friction welding device.

In FIG. 2, 17a and 17b are joining members, and 16a and 16b are jigs for gripping the joining members. The jig 16b on the pressurizing side is the cylinder 18
This allows pressure to be applied in the direction of arrow 19.

The jig 16a on the moving side is connected to the eccentric portion 14a of the rotating shaft 14 via the bearing 10,
Further, rotation is restrained by a restraint device 20.

The rotating shaft 14 is connected to a motor 11 via a brake 13 and a clutch 12, and can be rotated by the motor 11 as shown by an arrow 15.

FIG. 3 shows the jig 16a and rotating shaft 1 of the device shown in FIG.
The connection relationship with 4 is shown in detail.

When the rotating shaft 14 is rotated in such a combination, like the jig 16a, it moves in a circular orbit having a radius equal to the distance r between the center _O0 of the rotating shaft 14 and the center _O1 of the rotating shaft 14a.

That is, the joining members 17a and 17b perform a frictional motion relative to each other in a circular orbit.

In addition, in the device shown in FIG. 2, if the hole 21 of the jig 16a circumscribing the bearing 10 is made into an elongated hole as shown in FIG. This is a reciprocating motion that strokes.

As described above, there are several types of friction welding devices depending on the type of frictional motion, but all of them have the drawback that it is not possible to determine the quality of the welded products during the welding process.

The present invention provides a method and apparatus that can determine the quality of the joint during the welding process in friction welding using various motion forms.

Conventionally, it was thought that there was no good inspection method other than destructive inspection for production control of friction welding. Therefore, in the past, defects were prevented by using a welding device with high accuracy in setting conditions and by selecting welding conditions with sufficient margin.

It was thought that conventional welding conditions such as friction speed, friction pressure, and friction time could be managed with this management method, but even if welded under carefully-scrutinized welding conditions, defective products may still be produced. Sometimes it comes out.

After intensively investigating this point, we discovered that the stopping acceleration of frictional motion, which had not been marked at all in the past, was a major factor.

The graph in FIG. 5 has time on the horizontal axis and acceleration on the vertical axis, and schematically shows changes in acceleration during welding. In FIG. 5, L is the portion where the frictional velocity is increasing at the start of the movement. M is a portion where a predetermined friction speed is reached and there is no speed change. N is the point at which the vehicle starts to stop, and acceleration in the opposite direction to that during acceleration, that is, stop acceleration begins to be added.

The stopping acceleration increases as the normal speed decreases as shown in FIG.

However, as shown in FIG. 6, it may become saturated after a certain period of time. This depends on the characteristics of the braking device of the welding equipment.

It was found that the maximum value of the stopping acceleration V max shown in FIG. 5 has a close relationship with the bonding performance.

FIG. 7 is an example. The graph in Figure 7 is
The relationship between the breaking strength S and the maximum acceleration Vmax was investigated for pieces of the same shape joined under various joining conditions.

According to FIG. 7, it can be seen that the larger V〓max is, the better the bonding performance is.

The stopping acceleration is mainly determined by the ability of the braking system of the welding device, but in many cases, braking by friction is used, so it is difficult to manage it with good reproducibility.

In particular, the maximum stopping acceleration is greatly affected by the condition of the friction plate, the stress condition applied to the friction joint surface, or mechanical disturbance.

Therefore, it is impossible to control other welding conditions with good reproducibility even if we use a device with high condition setting accuracy and set other joining conditions, such as upset pressure and rotation speed, in advance. A practical way to deal with this is to actually measure the maximum stop acceleration V〓max every time it is joined to determine whether the joined products are good or bad.

The criteria for determining pass/fail differs depending on the required performance of the joining member and the joining product. In Figure 7, the passing criteria are A,
Whether B or C is selected depends on the technical level and the nature of the product.

In addition, to determine whether the friction is good or bad, first perform welding several times under various conditions for friction welding, and then examine the strength of the weld to determine the relationship between the maximum stopping acceleration when the friction motion stops and the joint strength. Based on this relationship, a reference value corresponding to the required bonding strength is determined in advance, and this value is compared with the measured value of the maximum acceleration, and when the measured value is smaller, it is determined to be defective.

FIGS. 8 to 12 show devices directly used to carry out the method of the present invention, and show the maximum stopping acceleration at the time of stopping the frictional motion of the conventionally known friction welding device shown in FIGS. 1 and 2. Provide a means to measure the acceleration and display the measured value, or compare the measured value with a preset standard acceleration and display whether it is good or bad.
Alternatively, it is a device that sorts bonded products into non-defective products and defective products.

The means for measuring the stopping acceleration may be any generally known method, such as using mercury or using a weight. Alternatively, it may be of a type that measures the speed and differentiates it.

Furthermore, the acceleration may be measured over the entire period required for stopping, and the maximum acceleration may be determined by data processing, or a measuring instrument that can detect only the maximum acceleration from the beginning may be used.

The measured acceleration may be recorded and displayed on an oscilloscope or a data recorder, but only the maximum value may be displayed.

The maximum acceleration is compared with a preset reference value, and when the measured value is larger, it is displayed as a non-defective product, or the bonded product is classified as a non-defective product.

FIGS. 8 and 9 show an example of an apparatus in which a mass body 41 is disposed around the rotating shaft 4, and the stopping acceleration is measured by measuring the stress applied to the mass body 41 during stopping.

In FIG. 8, a mass body 41 and a rotating shaft 4 are connected through a flexible portion 42, and a strain gauge 43 is attached to this flexible portion 42.

In this way, when the rotating shaft 4 stops, the movement of the mass body 41 is delayed due to acceleration, and
Since the flexible portion 42 bends, if this degree is detected by the strain cage 43, the stopping acceleration can be determined.

In the method shown in FIG. 9, a mass body 41 disposed around a rotating shaft 4 is forced in a rotating direction 5 as shown by an arrow by a spring 47 with an appropriate stress. When the shaft 4 is stopped in this state, the mass body 41 moves in the counter-rotation direction against the spring 47 due to the acceleration of the stop.

Since this amount of movement corresponds to the stopping acceleration, if an electric switch 45 is placed at an appropriate position on the trajectory of the mass body, the electric circuit can be opened or closed when a predetermined acceleration is reached. can do.

Therefore, if the switch 45 is incorporated into an electric circuit that displays the quality determination, and the strength of the spring 47 and the position of the switch 45 are set appropriately, the quality of the bonded product can be known from the display during the bonding process. .

Next, an example of an automatic sorting device will be described.

In the bonding apparatus shown in FIG. 10, a hole 51 is provided in the base 50 below the gripper 6. A two-way chute 52 having a switching damper 53 is provided in the hole 51 .

The damper 53 rotates around the shaft 51, and assumes a position 53a indicated by a solid line and a position 53b indicated by a dotted line. When the damper 53 is not in operation, the spring 5
7, the tank takes the position 53a indicated by the solid line, so the tank A side of the chute is open.

A spring 5 is connected to the shaft 54 via an electromagnetic clutch 55.
It is a constant torque motor 56 whose rotation direction is opposite to the operating direction of 7.

The electromagnetic clutch 55 is arranged in a circuit as shown in FIG. 12 and connected to the strain gauge shown in FIG.

In Figure 12, AMP is an amplifier, R is a variable resistor,
Tr is a triax, DC is a direct current power supply, K is an electromagnetic clutch 55, and Ti is a timer.

With such a device, when the variable resistance is adjusted and the acceleration reaches the maximum stop acceleration (set by R), the triac Tr is activated, the electromagnetic clutch is activated, and the damper 53 is rotated by the motor 56 against the spring 57. Then, it takes the position 53b indicated by the dotted line. Therefore, the shoot 52 sets the timer Ti
The tank B side will open for a preset time.

Therefore, the joined products that have been removed from the gripper after joining fall into the hole 51 and are sorted into tank B, which is a stock of defective products, through the chute 52b.

If the product is normal, the voltage of X does not reach the trigger voltage of the tri-ac, so
In case 2, tank A side is open, and products are sorted into tank A with good quality products.

The above is an example of an automatic sorting device, and it goes without saying that any other automatic sorting device can be employed.

In the embodiment, an example of plastic is shown, but the present invention can be similarly applied to welding of metal.

As explained in detail above, by carrying out the present invention, it is possible to determine the quality of the joint during the welding process, which was previously impossible, so it is possible to easily improve the quality of the joined product, and also to reduce the inspection process. By eliminating this, it is possible to reduce costs.

[Brief explanation of the drawing]

Figure 1 shows an example of a conventionally known friction welding device.
Figure 2 shows another example of a conventionally known friction welding device. FIG. 3 is a detailed view of the engagement portion between the rotating shaft and the welding jig of the friction welding device shown in FIG. 2. FIG. 4 is an explanatory diagram of yet another friction welding device, and FIG.
The X′ plane is shown. FIG. 5 is a graph showing changes in acceleration of frictional motion in the friction welding device. FIG. 6 is a graph showing an example of a change in stop acceleration over time. FIG. 7 is a graph showing an example of the relationship between maximum stopping acceleration and joining performance of joined products. 8th, 9th
The figure is a partial diagram of the stop acceleration measuring device of the present invention. 1st
Figures 0 and 11 are a cross-sectional view and a perspective view of the automatic sorting device. FIG. 12 shows an electrical circuit diagram of the automatic sorting device. 4... Rotating shaft, 41... Mass body, 42... Flexible portion, 43... Strain gauge, 45... Switch, 4
7...Spring.

Claims (1)

[Claims] 1. In a welding method in which the joined parts of joined members are butted against each other, rubbed against each other, the joined parts are melted, the frictional motion is stopped, and the fused parts are cooled and solidified to join the joined members. Welding is performed based on various conditions for welding, the relationship between the maximum stopping acceleration when the frictional motion stops and the bonding strength is determined, and a reference value corresponding to the required bonding strength is determined in advance from this relationship. , A method for determining the quality of a joined product by friction welding, in which the maximum stopping acceleration at the time of stopping frictional motion is measured, and when the value is smaller than the above-mentioned reference value, the joined product is determined to be defective. 2. In a device that butts the joint parts of joining members and rubs them against each other to join them, a means for measuring the stopping acceleration when the frictional motion stops, a means for displaying the measured value, or a comparison of the measured value with a preset reference value. 1. A device for determining the quality of a jointed product by friction welding, characterized in that it has means for displaying whether the jointed product is good or bad, or means for sorting the joined product into good or defective products. 3 In claim 2, the frictional motion is generated by a rotating shaft, and a movable mass body is disposed around the rotating shaft, and the stoppage is achieved by measuring the stress applied to the mass body at the time of stopping. A device for determining the quality of jointed products using friction welding that measures acceleration.