JPH07195183A - Method and device for judging quality of friction welding product - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to distinguish between good and bad from the characteristics of the sampling data of the chuck rotation speed and the load applied to the work, and in the case of bad, the detailed factors can be easily and efficiently determined. To do so. [Structure] The rotation number of a chuck 17 that grips and rotates a work 18 is detected by a rotation detector 16, and a load detector 23 connected to a clamp 20 that grips and slides a work 19 applies to the work 18 and the work 19. The load is detected, the data is input to the central controller 33, the temporary data is stored in the data storage device 38, and the comparison and determination device 39 compares the data with a non-defective product,
The detailed cause of the defect is determined from the characteristics of the sampling data. [Effect] It is possible to determine the detailed factor of a defective product, and it is possible to significantly reduce the time required for countermeasures against defects in the apparatus and working conditions, and it is possible to promote high reliability of the product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction welding product in which one work is rotated and the other work is pressed against the rotating work and the two are joined by utilizing the friction heat generated on the contact surface. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for determining the quality of a friction welding product for determining the quality of a joined portion.

[0002]

2. Description of the Related Art Conventionally, as a pass / fail judgment of a friction welding product,
As disclosed in Japanese Unexamined Patent Publication No. 3-32480, the torque and the rotational speed of the spindle are detected, the frictional heat generation amount is calculated from these data, and this heat generation amount is compared with a reference value of the heat generation amount of a non-defective product. A method for making a pass / fail judgment is known.

Further, Japanese Patent Application Laid-Open No. 57-22899 discloses a device which judges the quality by measuring the time from the start to the end of the frictional movement. Furthermore, JP-A-57
No. 22891 discloses measuring the frictional force at the joint surface during frictional movement. In addition to this, there is also known a device that judges the quality based on the deformation amount of a member.

[0004]

Although some defective products can be judged from the appearance, such as the deformation amount of the member, many defective products cannot be judged from the appearance. In other words, since joining involves changes in the metal structure such as melting, it is not possible to visually confirm whether the changes in the structure are being performed well, and non-destructive inspection can only be performed using ultrasonic waves. Cannot be introduced.

Further, in the above-mentioned prior art, it is not possible to determine the cause of the defect from the detected data for the product determined to be defective, and to determine or estimate the defect factor, the bonding conditions are changed. It was necessary to estimate the factor from the joining condition and joining results after joining many times. In this method, not only the determination accuracy is poor, but also a lot of time is required for the determination.

[0006] The defective factors include those related to materials and mechanical and control conditions of the apparatus. Factors related to the material include, for example, surface roughness of the joint surface, parallelism of the joint surface, oxide film on the joint surface, oil adhesion on the joint surface, hardness of the material,
The ingredients of the material are listed. Factors related to mechanical and control conditions of the device include clutch slippage, clutch trip time, bearing friction coefficient, guide rail friction coefficient, hydraulic system oil temperature, hydraulic servo characteristics, control input data, etc. To be

The present invention has been made in view of the circumstances of the prior art as described above, and a first object thereof is to easily and efficiently discriminate a good product from a defective product by extracting a feature from sampling data. To provide. A second object is to provide a method for easily and efficiently determining a detailed cause of a defect. Further, a third object is to provide a device capable of easily and efficiently discriminating good products from defective products.

[0008]

The first object is to detect the rotation speed of the chuck and the load applied to the work from before the start of the pressure contact to the end of the pressure contact, and sample the data of the rotation speed and the load which change with time. By the first means, the sampled data is compared with the data of the non-defective product stored in advance, and if the deviation of the comparison result is within the permissible range, it is determined as the non-defective product and if the deviation is outside the permissible range. To be achieved.

The second object is to judge the cause of the defective product from the characteristics of the pattern of the temporal change of the sampling data although the deviation by the first means is outside the allowable range and is judged to be the defective product. It is achieved by two means.

The third object is to rotate the first gripping means for gripping one work to be joined, the second gripping means for gripping the other work to be joined, and the first gripping means. The rotation driving means and the second gripping means are moved toward and away from the first gripping means so that the end surface of the other work is brought into pressure contact with the end surface of the one work, and the rotation driving means. Rotation speed detecting means for detecting the rotation of the pressure contact driving means, load detecting means for detecting the load applied to the pressure contact driving means, and first storing means for storing the change in the rotation speed from the rotation speed detecting means with time. By a third means including a second storage means for storing a change in the load with time from the load detection means, and a display means for displaying the information stored in the first and second storage means. To be achieved.

Further, the third object can also be achieved by a fourth means which further comprises a judging means for judging the quality of the friction welding product from the pattern displayed on the display means.

[0012]

In the first means, the number of rotations of the chuck and the load applied to the work from the start of the pressure contact to the end of the pressure contact are detected, the detected value is sampled as a function of time, and the sampled data is stored in advance. If the deviation of the sampling data from the non-defective product data is within the allowable range, it is determined to be non-defective, and if it is not within the allowable range, it is determined to be defective. Therefore, if the sampling data can be obtained, it is possible to determine whether the product is a good product or a defective product.

In the second means, the cause of the defective product is determined from the characteristics of the temporal change in the sampling data of the product which is determined to be defective. This is because it was found that the appearance pattern of the above sampling data has a certain pattern depending on the cause of the defect.

In the third means, one work is held by the first gripping means and is rotated by the rotation driving means, the second gripping means is held by the other work, and the other work is held by the pressure contact driving means. The workpieces are pressed against one of the rotating workpieces, and the end surfaces of the workpieces are locally melted by a frictional force, so to speak, to join the tissues by integrating them. The rotation speed data at this time is obtained by the rotation speed detecting means, and the applied load is obtained by the load detecting means.
These obtained data are stored in the first and second storage means and displayed on the display means as a function of time, for example. Then, from the characteristics of the pattern of the data displayed in this way, it is judged by the operator or the inspector whether good or bad.

In the fourth means, the judging means extracts the characteristic points of the pattern, judges whether the pattern is good or bad, and outputs the judgment result. Therefore, it is possible to judge whether the operator is a familiar operator or not.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the outline of a friction welding device and its control device. The friction welding device is composed of two mechanisms, a mechanism for rotating one work and a mechanism for pressing the other work against the rotating work,
Each of the control devices executes the control described later.

The mechanism for rotating the work is the work 1
Chuck 17 for holding 8 and rotating shaft 1 of chuck 17
It is composed of a drive mechanism that rotates 2 and a transmission mechanism that transmits the rotational force from the drive mechanism. The drive mechanism includes a motor 1, a pulley 5, and a first electromagnetic clutch 3 provided between the rotation shaft 2 of the motor 1 and the rotation shaft 4 of the pulley 5, and the transmission mechanism includes a rotation of the chuck 17. Mainly includes a shaft 12, a pulley 7, a second electromagnetic clutch 11 provided between the rotary shaft 10 of the pulley 7 and the rotary shaft 12, and a belt 6 stretched between the pulleys 5 and 7. The rotary shaft 10 is provided with a flywheel 9 and the rotary shaft 1
A rotation detector 16 for detecting the number of rotations of the chuck 17 is provided on the roller 2 via pulleys 13 and 15 and a belt 14.

The mechanism for pressing the work is a clamp 20 provided on the guide rail 21 so as to advance and retract.
A hydraulic cylinder 25 for moving the clamp 20 forward and backward via the rod 24 and the shaft 22, and a hydraulic pump 31.
And a servo valve 26 for controlling the movement of the hydraulic cylinder 25 and controlling the supply of pressure oil from the hydraulic cylinder 25 to the hydraulic cylinder 25. A load detector 23 is provided between the rod 24 and the shaft 22.
Is provided.

These mechanisms are controlled by the central controller 33. That is, the motor 1 has the rotation control device 34.
The first electromagnetic clutch 3 is the first clutch control device 3
5, the second electromagnetic clutch 11 is controlled by the central controller 33 via the second clutch controller 36, the hydraulic pump 31 is directly controlled by the central controller 33, and the servo valve 26 is controlled by the pressurizing force controller 32. Respectively controlled via. Further, the rotation number of the chuck 17 detected is input from the rotation detector 16 as a rotation number signal, and the pressure applied to the clamp 20 side by the hydraulic cylinder 25 is input from the load detector 23 as a load signal. Further, these rotation speed signal and load signal are output as rotation speed data and load data to the data storage device 38 including the first and second storage means, and the data storage device 3 is output.
The stored data is output to the comparison / determination device 39 having a display device (not shown). A reference numeral 37 is a data input device, which is capable of inputting comparison data or the like, which is a comparison reference for determination, to the central control device 33. Reference numerals 40a and 40b are pipes connecting the servo valve 26 and the hydraulic cylinder 25, and reference numerals 40c and 40d are pipes connecting the hydraulic pump 31 and the servo valve 26.

When friction welding is performed using the friction welding device configured as described above, the motor 1 is rotated by a command from the central control unit 33, the first electromagnetic clutch 3 is connected, and the pulley 5 and the belt are connected. Pulley 7 through 6
The rotation is transmitted to and the flywheel 9 is rotated. At the start of rotation, the second electromagnetic clutch 11 is engaged, and when the rotation stabilizes at a predetermined rotation speed, the first electromagnetic clutch 3
Then, the chuck 17 and the work 18 held by the chuck 17 are rotated by the inertial force of the flywheel 9.

On the other hand, in the work 19 clamped by the clamp 20, the servo valve 26 is driven by a command from the central control unit 33 from a standby position facing the end surface of the work 18 and separated from it, and the rod 24 is driven by the hydraulic cylinder 25. Moves forward, the clamp 20 slides on the guide rail 21 in the direction of the chuck 17, and grips the workpiece 19
The end surface of is pressed against the end surface of the rotating work 18. After a lapse of a preset time, for example, 1 second, the central control device 33 sends a command to the second clutch control device 36 to disengage the second electromagnetic clutch 11. As a result, the chuck 17 becomes free, and the rotation of the chuck 17 and the work 18 is stopped when the two works 18 and 19 are joined.

The state of rotation of the chuck 17 during this period is taken into the central control unit 33 as a rotation speed signal, and the load of the work 19 on the work 18 by the load detector 23 is also taken into the central control unit 33 as a load signal. The data captured is a data storage device 3 as a function of time.
8 and is output to the comparison / determination device 39 as needed. The comparison / determination device 39 displays the reference data of the non-defective product and the sampled data, and the operator determines the good / defective and the cause of the defective by looking at the displayed data pattern.

The central control unit 33 gives a command to the pressurizing force control unit 32 to operate the servo valve 26 to adjust the oil pressure and flow rate, but the temperature sensor 30 is attached to the hydraulic pump 31. The signal is fed back to the central controller 33 and controlled so that the oil temperature becomes constant.

2 and 3 show a processing procedure for judging the quality of the pressure contact product and analyzing the cause of the defect, and FIG. 4 shows a characteristic diagram in which the rotational speed and the load are detected with time and plotted. . In the procedure of pass / fail judgment shown in FIGS. 2 and 3,
First, in step S100, the rotational speed n and the load p are sampled all the time from just before the start of friction welding to the end of the pressure welding, or at any partial time, and from the sampled rotational speed n, a non-defective product at that time is determined. Absolute value of the value obtained by subtracting the reference value n'of the rotation speed data | n-n '
| And the allowable value ε are compared and the load p sampled at the same time
Is subtracted from the reference value p'of the load data of the non-defective product at that time, and the absolute value | p-p '| is compared with the allowable value δ. In FIG. 4, the solid line indicates the reference value n ′ of the rotational speed data of the non-defective product and the reference value p ′ of the load data of the non-defective product. The dotted line shows the sampled rotation speed data n and load data p. Therefore, the above | n−
n ′ | and | p-p ′ | indicate the deviation amount of the sampling data from the reference value at the same time. In addition,
In FIG. 4, the friction welding starts at time t ₀ when the load data is 0, and ends at time t ₄ when the rotation speed data is 0.

Therefore, the product must be a non-defective product if, at any given time, the deviation from the reference value is within an allowable range determined by experiments, that is, ε for the number of revolutions and δ for the load. That is, | n−n ′ | ≦ ε (1) and | p−p ′ | ≦ δ (2) are satisfied. Therefore, if the expressions (1) and (2) are satisfied in step S100, step S10
It is judged as a non-defective product with 1.

If the above criterion is not satisfied in step S100, it is determined that the product is defective, and the process proceeds to the determination in step S102. The solid line in FIG. 5 is the pattern of the rotation speed data and load data of a non-defective product (optimal condition) that changes with time, as in FIG. In step S102, it is determined whether N ₀ −β ≦ n ′ ≦ N ₀ + β (3) holds. That is, the rotation speed n at time t ₀ at the start of friction welding is (reference value N ₀ of the rotational speed data of good - tolerance beta) between the (reference value of the rotational speed data of the non-defective N ₀ + tolerance beta) If not, step S10
In 3, it is determined that the rotation system is abnormal. The allowable value β in this case is a value determined by experiment.

Thus, the rotation speed fluctuates beyond the allowable value β due to, for example, an abnormality in the rotation speed control command of the motor 1 of the drive source or the rotation speed due to slippage of the second electromagnetic clutch 11. It may be due to deterioration or mechanical abnormality due to running out of grease in the bearing.

When it is determined in step S102 that the expression (3) is satisfied, the process proceeds to step S104, and the sampling is performed before the friction welding start time t ₀ (at least the time t.
_{If the} load data p (sampled at ₀ ) is equal to or greater than the determination reference value p _a , that is, if p ≧ p _a (4), it is determined in step S105 that the slide shaft 22 is mechanically abnormal. . FIG. 6 shows the slide shaft 22.
Is the sampling data when the mechanical properties of are poor.
Factors load p before pressure welding, ideally but good zero, the load is detected by the friction of the guide rail 21, when the load reaches or exceeds the allowable value p _a, which affects the pressure conditions, making defective products Becomes

If the judgment criterion in step S104 is not satisfied, the process proceeds to step S106, in which the absolute value | p-p '| of the deviation between the load p sampled immediately after the start of friction welding and the reference data p'of non-defective products is tested. Is compared with the allowable value α determined by This allowable value α was introduced because load fluctuation occurs after the frictional pressure welding is started when the joint surface is rough, as shown in the characteristic diagram in which the rotational speed data and the load data are plotted over time in FIG. 7. That is, as shown in the enlarged view of the load fluctuation portion of FIG. 8 (enlarged view of portion A in FIG. 7), the distribution of the load data p ′ of the non-defective product under the optimum conditions and the sampled load data p can be seen to determine whether the joint surface is good or bad. Because you can judge.

Therefore, when | p-p '| ≧ α (5) is satisfied and the deviation repeatedly occurs alternately with plus and minus, in step S107, the surface roughness of the joint surface is rough and the processing defect is caused. It is determined that

If the criterion of step S106 is not satisfied, the process proceeds to step S108 of FIG. 3 and, as shown in the characteristic diagram of FIG. 9, the load immediately rises immediately after the start of friction welding, and the load is first determined. Peak load p ₁
Of time t ₁ and the time t ₁ ′ of load p ₁ ′ at which the load peaks at the beginning of non-defective product exceeds t ₁ −t ₁ ′ and the deviation p ₁ −p ₁ ′ of load is allowable. If the value is less than or equal to Δp _1, that is, if t ₁ −t ₁ ′ ≧ r (6) and p ₁ −p ₁ ′ ≦ Δp ₁ (7), then FIG. Δl in the radial direction of the end face as shown
_{There is} a difference of ₁₂ and the parallelism between the joining surfaces of the workpieces 18 and 19 is poor, or the axial centers of the workpieces 18 and 19 to be joined are misaligned by Δl ₁₁ , for example. In this case, it is determined that the product is defective in step S109. In addition,
t ₂ is the time when both the loads p ₁ and p ₁ ′ match.

The judgment criteria of step S108 are satisfied.
If not, the process proceeds to step S110 and the characteristic diagram of FIG.
As shown in, the load data p is the optimum load data for the optimum condition.
Judgment whether it is rising suddenly compared to the pattern
To do. If it is determined that you are standing up, step
In S111, the oil temperature in the hydraulic cylinder 25 becomes extremely high.
It is judged to be low or abnormal in the pressure oil control system. On the other hand,
If the judgment criteria of step S110 are not satisfied,
If another abnormality occurs in step S112
Determine. Other anomalies include different material hardness
Case, or hydraulic system abnormality, control data setting error,
For example, the oil temperature in the hydraulic cylinder may be low. These services
An example of the sampling data is shown in FIG. Where the load
Data p ₂Is the case where the hardness of the material is high, and the load data
p₃Is when the hardness of the material is low.

As described above, according to this embodiment, the quality of the joining of the works 18 and 19 is determined from the equations (1) and (2) based on the characteristics shown in FIG. And
If the equations (1) and (2) are not established, the abnormality of the rotary system is further determined from the characteristic of FIG. 5 by the equation (3), and the mechanical operation of the slide shaft 22 is determined by the equation (4) from the characteristic of FIG. The quality of the characteristic is determined, and the quality of the surface roughness of the joint surface is determined from the characteristic of FIG. 7 by the equation (5). further,
From the characteristics of FIG. 9, whether the parallelism of the joining surfaces or the deviation in the axial direction is determined by the expressions (6) and (7) is determined, and whether the oil temperature of the hydraulic cylinder 25 is extremely low is determined from the characteristics of FIG. The abnormality of the pressure oil control system is determined, and the other abnormality is determined from the characteristics of FIG.

This determination may be performed by the operator or the inspector himself by displaying data on the comparison / determination device 39, or on the display device of the comparison / determination device 39 together with the data pattern or in place of the data pattern. May be displayed to display the quality of the joined product and the cause of the above-mentioned defect or abnormality. With the latter configuration, even a skilled person or a person who has not been trained in the determination can easily determine the pass / fail, and can promptly deal with an abnormality or a defect.

[0036]

As described above, according to the present invention,
It has the following effects. That is, the number of rotations of the chuck from the start of pressure welding to the end of pressure welding is detected, and the load applied to the work is detected. According to the invention of claim 1, it is determined that the deviation of the comparison result is within the allowable range and that the deviation is out of the allowable range.
It is possible to easily and efficiently determine whether the product is a good product or a defective product only by taking sampling data of the number of revolutions and the load from the data of the good product stored in advance and comparing them.

According to the present invention, the cause of the defective product is discriminated from the characteristic of the temporal change of the sampling data when the defective product is determined. Therefore, the characteristic points of the sampling data can be clearly extracted. In addition, the cause of the defect can be efficiently determined.

First and second gripping workpieces to be joined
The gripping means, the rotation driving means for rotating the first gripping means, and the second gripping means in proximity to the first gripping means.
Detecting the load applied by the pressure contact drive means for causing the end face of the other work to come into pressure contact with the end face of the one work, the rotation speed detection means for detecting the rotation of the rotation drive means, and the load applied by the pressure contact drive means. Load detection means, first storage means for storing the change in the rotational speed from the rotation speed detection means with time, and second storage means for storing the change in the load with time from the load detection means. According to the invention of claim 3, further comprising display means for displaying the information stored in the first and second storage means, the work is rotated to press the end face of the work under pressure, and the number of rotations therebetween. Variations and load variations are detected, and these are stored in the storage means and displayed on the display means as sampling data. Therefore, from the deviation of the displayed sampling data pattern from the non-defective data and the characteristics of the pattern. Another defect, can further determine the cause of failure easily and efficiently.

10. The method according to claim 4, further comprising a judging means for judging the quality of the friction welding product from the pattern displayed on the display means.
According to the invention described, the determination means extracts the difference between the characteristics of the sampling pattern and the pattern of the non-defective product to clarify the cause by comparing it with the cause of the defect, and further outputs this cause. Both good and defective are determined, and the cause of the defect is also determined, so that even an unskilled person can accurately respond to the cause of the defect, and quality control can be performed easily and efficiently. .

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a friction welding device and a control device thereof.

FIG. 2 is a flowchart showing a part of a processing procedure for judging whether the pressure contact product is good or bad and the cause of the defect.

FIG. 3 is a flowchart showing another part of a processing procedure for judging whether the pressure contact product is good or bad and determining the cause of the defect.

FIG. 4 is a characteristic diagram showing a sampling data pattern of a non-defective product.

FIG. 5 is a characteristic diagram showing a sampling data pattern when there is an abnormality in the rotating system.

FIG. 6 is a characteristic diagram showing a sampling data pattern when the mechanical characteristics of the slide mechanism are poor.

FIG. 7 is a characteristic diagram showing a sampling data pattern when the surface roughness of the joint surface is rough.

8 is an enlarged view showing details of a portion A in FIG.

FIG. 9 is a characteristic diagram showing a sampling data pattern when the dimensional accuracy of the joint surface is poor.

FIG. 10 is a cross-sectional view of the work when the dimensional accuracy of the joint surface is poor.

FIG. 11 is a characteristic diagram showing a sampling data pattern when the oil temperature of the hydraulic cylinder is low.

FIG. 12 is a characteristic diagram showing a sampling data pattern when the hardness of a material is different from that of a non-defective product.

[Explanation of symbols]

 1 Motor 2,4,10,12 Rotating Shaft 3 First Electromagnetic Clutch 4 Rotating Shaft 5,7,13,15 Pulley 6,14 Belt 9 Flywheel 16 Rotation Detector 17 Chuck 18,19 Workpiece 20 Clamp 21 Guide Rail 22 axis 23 load detector 24 rod 25 hydraulic cylinder 26 servo valve 32 pressing force control device 33 central control device 34 rotation control device 35, 36 clutch control device 37 data input device 38 data storage device 39 comparison judgment device

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Osamu Matsushima 1-1-1 Kokubun-cho, Hitachi-shi, Ibaraki Hitachi Kokubun Plant, Ltd. (72) Inventor Satoru Shirata 1-1-1 Kokubun-cho, Hitachi-shi, Ibaraki No. 1 Stock company Hitachi Kokubu factory

Claims (4)

[Claims] 1. The quality and / or the cause of a defect of a friction welding product in which a work gripped by a chuck is rotated and another work is pressed against the end surface of the rotating work to join the both works is determined. In the method for determining the quality of friction welding products, the rotation speed of the chuck and the load applied to the work from the start of the welding to the end of the welding are detected, and the data of the rotation speed and the load that change with time are sampled. A method for determining the quality of friction-welded products, which compares the stored data of non-defective products, and determines that the deviation of the comparison result is within the allowable range, and judges that the deviation is outside the allowable range as defective product. . 2. The friction according to claim 1, wherein the cause of the defective product is determined from a characteristic of a temporal change pattern of the sampling data of the product which is determined as the defective product when the deviation is out of the allowable range. How to judge the quality of pressed products. 3. A quality determination device for a friction welding product, which determines the quality of a pressure contact portion of a friction welding product, in which end faces of at least one of two rotating works are joined by friction welding force. The first gripping means for gripping the workpiece, the second gripping means for gripping the other workpiece to be joined, the rotation driving means for rotating the first gripping means, and the second gripping means for the first gripping means. Of the other work by pressing the end face of the other work into pressure contact with the end face of the one work, rotation speed detection means for detecting the rotation of the rotation drive means, A load detecting means for detecting the applied load; a first storage means for storing a change in the rotational speed from the rotational speed detecting means with time; and a first storage means for storing the change in the load with time from the load detecting means. The storage means, said first and second display means for displaying the stored information in the storage means, friction welding products diagnosis device, characterized in that it comprises. 4. The device for judging the quality of a friction welding product according to claim 3, further comprising a judging device for judging the quality of the friction welding product from the pattern displayed on the display means.