Abnormality determination and estimation method for product of plastic working, and an abnormality determination and estimation device

• US 7,054,789 B2
• Filed: 06/02/2004
• Issued: 05/30/2006
• Est. Priority Date: 06/02/2003
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation, Yonekura Manufacturing Company Limited
• Original Assignee: DENSO Corporation, Yonekura Manufacturing Company Limited
• Inventors: Murao, Masuaki, Onishi, Yasuhiro
• Primary Examiner(s): Nghiem, Michael
• Assistant Examiner(s): Bhat, Aditya S.
• Application Number:
  US10/859,482
• Publication Number:
  US 20040249611A1
• Time in Patent Office: 727 Days
• Field of Search: 702/58, 702/185, 738/08, 360/135
• US Class Current: 702/185
• CPC Class Codes: B21D 22/00 Shaping without cutting, by stamping, spinning, or deep-drawing otherwise than using rigid devices or tools or yieldable or resilient pads B21D26/00
• CPC Class Codes: G01N 2291/015 Attenuation, scattering
• CPC Class Codes: G01N 2291/0235 Plastics; polymers; soft materials, e.g. rubber
• CPC Class Codes: G01N 2291/2632 flat
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00

Abstract

The abnormality determination and estimation device (200a) estimates the presence or absence of an abnormality of the product of plastic working with respect to an elastic wave in processing of a non-defective product, based on a first elastic wave A1 that is an elastic wave generated in a processing step immediately before an upper die comes into contact with a lower die after the beginning of plastic working, a second elastic wave A2 that is an elastic wave generated in a processing step when the upper die comes into contact with the lower die, and a third elastic wave A3 that is an elastic wave generated in a processing step after the upper die comes into contact with the lower die. This makes it possible to improve the precision of abnormality detection and discriminate the abnormalities.

Claims

1. An abnormality determination and estimation method for a product of plastic working, comprising:

providing an AE sensor in a processing apparatus of the product of the plastic working, for detecting an elastic wave in the processing apparatus; and

performing an abnormality determination and estimation for discriminating at least two or more abnormalities of the product of plastic working and estimating a presence or an absence of the abnormality for each processing step of the processing apparatus based on the elastic wave that is generated in the processing step of the plastic working detected by the AE sensor;

wherein

performing the abnormality determination and estimation step estimates the presence or absence of the abnormality of the product of plastic working with respect to an elastic wave in processing of a non-defective product, based on a first elastic wave that is an elastic wave generated in a processing step immediately before an upper die comes into contact with a lower die after start of plastic working, a second elastic wave that is an elastic wave generated in a processing step when the upper die comes into contact with the lower die, and a third elastic wave that is an elastic wave generated in a processing step after the upper die comes into contact with the lower die.

2. The abnormality determination and estimation method for a product of plastic working according to claim 1, wherein

the plastic working is press working using the upper die and the lower die, the first elastic wave is an elastic wave for estimating an impact mark defect of a pressed product,

the second elastic wave is an elastic wave for estimating a defect caused by a breakage of the die,

and the third elastic wave is an elastic wave for estimating a defect caused by wear and the die.

3. The abnormality determination and estimation method for a product of plastic working according to claim 2, wherein

the impact mark defect of the pressed product is estimated by an integral value of the elastic wave generated in the processing step immediately before the upper die comes into contact with the lower die as the first elastic wave.

4. The abnormality determination and estimation method for a product of plastic working according to claim 2, wherein

the defect caused by the breakage of the die is estimated by the maximum value of the elastic wave generated in the processing step when the upper die comes into contact with the lower die as the second elastic wave.

5. The abnormality determination and estimation method for a product of plastic working according to claim 2, wherein

the defect caused by the wear of the die is estimated by the integral value of the elastic wave generated in the processing step after the upper die comes into contact with the lower die as the third elastic wave.

6. An abnormality determination and estimation device for a product of plastic working in the plastic working, comprising:

an AE sensor, provided in a processing apparatus of the product of the plastic working, for detecting an elastic wave in the processing apparatus; and

abnormality determination and estimation means for discriminating at least two or more abnormalities and estimating a presence or absence of the abnormality of the product of plastic working based on the elastic wave that is generated in the plastic working detected by the AE sensor for every processing step of the processing apparatus;

wherein

the abnormality determination and estimation device estimates the presence or absence of the abnormality of the product of plastic working based on a first elastic wave that is an elastic wave generated in a processing step immediately before an upper die comes into contact with a lower die after start of the plastic working, a second elastic wave that is an elastic wave generated in a processing step when the upper die comes into contact with the lower die, and a third elastic wave that is an elastic wave generated in a processing step after the upper die comes into contact with the lower die.

7. The abnormality determination and estimation device for a product of plastic working according to claim 6, wherein

the plastic working is press working using the upper die and the lower die, the first elastic wave is an elastic wave for estimating an impact mark defect of a pressed product,

the second elastic wave is an elastic wave for estimating a defect caused by a breakage of the die,

and the third elastic wave is an elastic wave for estimating a defect caused by the wear of the die.

8. The abnormality determination and estimation device for a product of plastic working according to claim 7, wherein

the impact mark defect of the pressed product is estimated by an integral value of the elastic wave generated in the processing step immediately before the upper die comes into contact with the lower die as the first elastic wave.

9. The abnormality determination and estimation device for a product of plastic working according to claim 7, wherein

the defect caused by the breakage of the die is estimated by the maximum value of the elastic wave generated in the processing step when the upper die comes into contact with the lower die as the second elastic wave.

10. The abnormality determination and estimation device for a product of plastic working according to claim 7, wherein

the defect caused by the wear of the die is estimated by the integral value of the elastic wave generated in the processing step after the upper die comes into contact with the lower die as the third elastic wave.

11. An abnormality determination and estimation method for a product of plastic working, comprising:

providing an AE sensor in a processing apparatus of the product of the plastic working;

detecting an elastic wave that is generated during a processing step of the plastic working in the processing apparatus, with the AE sensor;

discriminating at least two or more abnormalities of the product of the plastic working;

estimating a presence or absence of the abnormality for each processing step of the processing apparatus during the plastic working, based on the elastic wave detected by the AE sensor; and

estimating the presence or absence of the abnormality of the product of plastic working with respect to an elastic wave in processing of a non-defective product, based on a first elastic wave that is an elastic wave generated in a processing step immediately before an upper die comes into contact with a lower die after start of plastic working, a second elastic wave that is an elastic wave generated in a processing step when the upper die comes into contact with the lower die, and a third elastic wave that is an elastic wave generated in a processing step after the upper die comes into contact with the lower die.

12. The abnormality determination and estimation method for a product of plastic working according to claim 11, wherein

the plastic working is press working using the upper die and the lower die,

the first elastic wave is an elastic wave for estimating an impact mark defect of a pressed product,

the second elastic wave is an elastic wave for estimating a defect caused by breakage of the die, and

the third elastic wave is an elastic wave for estimating a defect caused by wear of the die.

13. The abnormality determination and estimation method for a product of plastic working according to claim 12, wherein

the impact mark defect of the pressed product is estimated by an integral value of the elastic wave generated in the processing step immediately before the upper die comes into contact with the lower die, as the first elastic wave.

14. The abnormality determination and estimation method for a product of plastic working according to claim 12, wherein

the defect caused by the breakage of the die is estimated by the maximum value of the elastic wave generated in the processing step when the upper die comes into contact with the lower die, as the second elastic wave.

15. The abnormality determination and estimation method for a product of plastic working according to claim 12, wherein

the defect caused by the wear of the die is estimated by the integral value of the elastic wave generated in the processing step after the upper die comes into contact with the lower die, as the third elastic wave.

16. An abnormality determination and estimation method for a product of plastic working, comprising:

providing an AE sensor in a processing apparatus of the product of the plastic working, for detecting an elastic wave in the processing apparatus; and

performing an abnormality determination and estimation for discriminating at least two or more abnormalities of the product of plastic working and estimating a presence or an absence of the abnormality for each processing step of the processing apparatus based on the elastic wave that is generated in the processing step of the plastic working detected by the AE sensor;

wherein

the abnormality determination and estimation step estimates the presence or absence of the abnormality for each processing step of the processing apparatus based on at least first and second elastic waves detected by the AE sensor;

the first elastic wave is generated in a processing step when a pair of opposite dies used for the plastic working are positioned at a first position; and

the second elastic wave is generated in a processing step when the pair of opposite dies used for the plastic working are positioned at a second position different from the first position.

17. An abnormality determination and estimation device for a product of plastic working in the plastic working, comprising:

an AE sensor, provided in a processing apparatus of the product of the plastic working, for detecting an elastic wave in the processing apparatus; and

abnormality determination and estimation means for discriminating at least two or more abnormalities and estimating a presence or absence of the abnormality of the product of plastic working based on the elastic wave that is generated in the plastic working detected by the AE sensor for every processing step of the processing apparatus;

wherein

the abnormality determination and estimation step estimates the presence or absence of the abnormality for each processing step of the processing apparatus based on at least first and second elastic waves detected by the AE sensor;

the first elastic wave is generated in a processing step when a pair of opposite dies used for the plastic working are positioned at a first position; and

the second elastic wave is generated in a processing step when the pair of opposite dies used for the plastic working are positioned at a second position different from the first position.

18. An abnormality determination and estimation method for a product of plastic working, comprising:

providing an AE sensor in a processing apparatus of the product of the plastic working;

detecting an elastic wave that is generated during a processing step of the plastic working in the processing apparatus, with the AE sensor;

discriminating at least two or more abnormalities of the product of the plastic working;

estimating a presence or absence of the abnormality for each processing step of the processing apparatus during the plastic working, based on the elastic wave detected by the AE sensor;

wherein

the abnormality determination and estimation step estimates the presence or absence of the abnormality for each processing step of the processing apparatus based on at least first and second elastic waves detected by the AE sensor;

the first elastic wave is generated in a processing step when a pair of opposite dies used for the plastic working are positioned at a first position; and

the second elastic wave is generated in a processing step when the pair of opposite dies used for the plastic working are positioned at a second position different from the first position.