JP2796597B2 - Automatic magnetic flaw detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic magnetic flaw detector for detecting cracks existing in a work without destroying the work.

[0002]

2. Description of the Related Art Metal powder is compacted into a predetermined shape.
Equipment for continuously manufacturing a large number of gears for vehicles by sintering the green compact is known. Magnetic flaw detectors are being studied as devices that magnetically determine whether or not cracks or the like are obtained in the obtained product without visual observation by an operator. This magnetic flaw detector is a work (inspection object)
When a magnetic field is magnetized, a constant magnetic field is generated in a crack-free portion, but when a crack is present, the magnetic flux in that portion fluctuates, and the change in the magnetic flux is detected by a magnetic sensor. It is intended to be taken out as.

[0003]

However, when a product such as a gear is magnetically flawed, the reliability is poor even if only one location is inspected, and the product may be located along an involute (teeth shape), a lead (tooth trace) or a tooth bottom. It is necessary to detect the entire circumference. However, in order to accurately detect flaws using a magnetic flaw detector, the distance between the surface of a workpiece to be inspected and the magnetic sensor must be kept constant. In order to keep the interval constant, it is conceivable to measure the workpiece shape before magnetic flaw detection and feed this measurement value to the magnetic flaw detector, but the apparatus becomes extremely large and the processing speed becomes slow. It is not suitable for testing a large number of products.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an automatic magnetic flaw detector according to claim 1 of the present application rotates a workpiece.
Automatic magnetic probe to inspect for cracks and other scratches while rotating
In a flaw detection device, this automatic magnetic flaw detection device
A pair above and below the two support members that move forward and backward
Make sure that the workpiece is
Each one that moves according to the touch of the flat part due to the rotation of the contacting work
The distance between the paired follower and the first inspected part of the work is constant
So that each of the followers is attached to one pair of the followers.
1 A magnetic flux detection sensor for inspecting the inspected part and a second
The other of the followers so that the distance from the part to be inspected is constant
Detection for inspection of the second part to be inspected attached to each pair
And a sensor. According to another aspect of the present invention, there is provided an automatic magnetic flaw detector which contacts a flat portion of a rotating workpiece and moves in response to the contact of the flat portion with the rotation of the workpiece, and a portion of the tracking member which abuts and follows the following portion. An interlocking body that interlocks with the body and a magnetic flux detection sensor attached to the interlocking body so that the distance between the inspection target portion of the work and the interlocking body are constant.

[0005]

When a workpiece to be inspected is rotated and magnetic inspection is performed along a predetermined portion of the workpiece, even if the workpiece has irregularities or the like on a flat surface or a peripheral surface, the follower moves according to the irregularities. Therefore, the distance between the inspection target portion of the work and the magnetic sensor is kept constant.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is an overall process diagram of a gear manufacturing apparatus incorporating the automatic magnetic inspection apparatus according to the present invention, and FIG. 2 is a plan view of an automatic magnetic inspection station. A raw material powder in which several kinds of elements are mixed is prepared, and the raw material powder is fed into the press forming device 2 by a fixed amount to be formed into a gear at a high pressure.

[0007] Next, after removing burrs on the surface of the molded body formed into a gear shape by the simple deburring device 3, the molded bodies are placed one by one on a ceramic tray and fired while being placed on the ceramic tray. After passing through the furnace 5, the sintering of the compact is completed.

[0008] Then, the sintered body carried out of the sintering furnace 5 is turned on the transfer device 7 and transferred onto the transfer device 8, and is conveyed to near the end of the transfer device 8 while being naturally cooled by air. After the ceramic tray is separated from the ceramic tray by the crack inspection device 9 for cracks, the normal ceramic tray is transported again near the entrance of the sintering furnace 5, and the sintered body is transferred to the stock station. From 10, the sinter is sent to a sizing device 13 via a deburring device 11 and a phase matching device 12, and the sintered body is recompressed in the sizing device 13 to remove thermal strain and to perform dimensioning.

[0009] Thereafter, the tooth surface accuracy of the sintered body is determined by the rolling device 14, and further, by taking out the difference in the quenching distortion due to the surface shape, the dispensing device 15 is used to set one of the front and back surfaces of the sintered body. After being discharged to the quenching / tempering device 16 as the upper surface, the quenching / tempering device 16 continuously quenches and tempers the sintered body, and then the product passes through the cleaning device 17 and the magnetic flaw detection station 18 according to the present invention. Is taken out as

As shown in FIG. 2, the magnetic flaw detection station 18 includes a temporary placing table 21, a first inspection station S1, and a second inspection station S2 from the upstream side to the downstream side.
The inspection unit 22, the demagnetization unit 23, the rust prevention unit 24, the centrifugal separator 25, and the unloading unit 26.
It is conveyed to the inspection station S1 and inspects the inner diameter part and the involute part of the gear W at the first inspection station S1, then inspects the lead part and the tooth bottom part of the gear W at the second inspection station S2, To the demagnetizing part 23, and the defective product
It is carried out to the stocker 29.

The first inspection station S1 for inspecting the inner diameter portion and the involute portion of the gear W is provided with the automatic magnetic flaw detector according to the second and third aspects of the present invention. An automatic magnetic flaw detector according to the first aspect of the present invention is disposed in a second inspection station S2 for inspecting a lead portion and a tooth bottom portion. The automatic magnetic flaw detector described in each claim will be described below with reference to FIGS.

FIG. 3 is a front view of the automatic magnetic flaw detector according to the second aspect of the invention, FIG. 4 is an enlarged view of a main part of FIG. 3, and FIG.
3A to 3C are front views illustrating the operation of the automatic magnetic flaw detector shown in FIG. 3. The automatic magnetic flaw detector 30 includes an air cylinder unit 33 above and below a support plate 32.
33, and these air cylinder units 33, 33
The followers 34, 34 are attached to the flat surface of the gear W so as to be able to move up and down.

The follower 34 has a roller 35, and the roller 3
5 comes into contact with the plane portion of the gear W by the resilience of the air cylinder unit 33. Therefore, when the gear W rotates and a shake occurs due to the rotation, the follower 34 moves up and down by the amount of the shake via the air cylinder unit 33.

On the side facing the support plate 32, a support plate 37 which moves forward and backward with respect to the gear W by the servo unit 36 is also arranged. The support plate 37 is connected to the support plate 37 via air cylinder units 38, 38. The interlocking bodies 39 are mounted so as to be able to move up and down with respect to the plane portion of the gear W.

An interlocking member 39 is provided with an adjusting bolt 40 which comes into contact with the follower 34 when the interlocking member 39 moves up or down toward the plane portion of the gear W, and a magnetic flux detecting sensor 4 such as a magnetic diode.
In the state where the roller 35 of the follower 34 contacts the flat portion of the gear W and the adjust bolt 40 contacts the follower 34, the distance t between the magnetic flux detection sensor 41 and the inspected portion is reduced. It is set to be constant (0.15 to 0.2 mm).

In order to perform the magnetic flaw detection of the inner diameter portion of the gear W using the automatic magnetic flaw detection apparatus 30, FIG.
As shown in (b), the follower 34 and the interlocking body 39 are made to stand by at a position vertically separated from the plane portion of the gear W, and then, as shown in FIG.
3, the follower 34 is raised or lowered until the roller 35 comes into contact with the flat portion of the gear W, and the interlocking body 39 is operated by the operation of the air cylinder unit 38, as shown in FIG.
Is raised or lowered until the adjusting bolt 40 comes into contact with the follower 34. In this state, the magnetized gear W is rotated, and a change in the magnetic flux is detected by the magnetic flux detection sensor 41, and is taken out as an electric signal to check for the presence or absence of a crack.

In the above-described automatic magnetic flaw detector 30, since the follower 34 and the interlocking body 39 are separate bodies,
By operating the adjustment bolt 40 or the like, the interval t between the magnetic flux detection sensor 41 and the inspection target can be arbitrarily set, and the interval between the follower 34 and the interlocking body 39 can be adjusted. There is also an advantage that can be applied.

FIG. 6 shows the arrangement at the first inspection station S1.
FIG. 3 is a plan view of a reference automatic magnetic flaw detector, which is provided with a follower 52 that advances and retreats from the side of a peripheral surface of a gear W by a servo unit 51.

The follower 52 pivotally pivots a head 54 with a pin 53 so that the head 54 can swing. The head 54 has a scanning surface 55 which is in sliding contact with the peripheral surface of the gear W. On the other hand, a magnetic flux detection sensor 56 is attached to the follower 52, and the interval t between the magnetic flux detection sensor 56 and the portion to be inspected (involute portion) is constant while the copying surface 55 is in sliding contact with the peripheral surface of the gear W. I have to.

Even in the automatic magnetic flaw detector 50 described above, the magnetized gear W is rotated, the fluctuation of the magnetic flux in the involute portion is detected by the magnetic flux detection sensor 56, and this is taken out as an electric signal to determine whether there is a crack. In particular, in this automatic magnetic flaw detection apparatus 50, by providing the head portion 54 having the copying surface 55, it is possible to accurately detect flaws even in a portion having a continuous uneven portion such as an involute portion. There is.

FIG. 7 is a front view of an automatic magnetic inspection apparatus which is arranged at the second inspection station S2 and inspects a lead portion (tooth trace) and an automatic magnetic inspection apparatus which inspects a tooth bottom. FIG. 9 is a front view of the automatic magnetic flaw detector shown in FIG. 7 in a standby state, and these automatic magnetic flaw detectors are all automatic magnetic flaw detectors according to the first aspect of the present invention.

First, an automatic magnetic flaw detector 70 for inspecting a lead portion (corresponding to a first inspected portion) has a servo unit 7
1, followers 74, 74 which are moved up and down with respect to the plane portion of the gear W by the air cylinder units 73, 73, are attached above and below a support plate 72 which moves forward and backward from the side of the gear W. Is provided with a roller 75 and a support block 76, and a magnetic flux detection sensor 77 is attached to the support block 76. When the roller 75 is in contact with the flat portion of the gear W, the distance t between the magnetic flux detection sensor 77 and the lead portion is increased. Is kept constant.

Similarly, the automatic magnetic flaw detector 80 for inspecting the bottom of the tooth (corresponding to the second inspected portion) includes the servo unit 8
1, followers 84, 84 which are moved up and down with respect to the plane portion of the gear W by the air cylinder units 83, 83 are attached above and below a support plate 82 which advances and retreats from the side with respect to the gear W. Is provided with a roller 85 and a support block 86, and a magnetic flux detection sensor 87 is attached to the support block 86. When the roller 85 contacts the flat portion of the gear W, the magnetic flux detection sensor 87
The interval t with the tooth bottom is made constant.

In the automatic magnetic flaw detectors 70 and 80 described above, since the magnetic flux detecting sensors 77 and 87 are provided on the followers 74 and 84 themselves or on a member integrated with the followers 74 and 84, the gear W is actually used.
And the distance between the rollers 75 and 85 in contact with the rollers can be reduced, and more accurate inspection can be performed.

In the embodiment, the follower and the interlocking member can be moved up and down with respect to the plane portion of the gear by the air cylinder unit, and the rollers and the like elastically contact the gear surface. Alternatively, an elastic member such as a spring or rubber may be used to make elastic contact.

[0026]

According to the present invention as described above,
In magnetically detecting flaws while rotating workpieces such as gears,
The follower is brought into contact with the flat surface or the peripheral surface of the work, and the magnetic sensor is attached to the follower itself or to an interlocking body interlocking with the follower, so that there is a run-out due to the shape of the work when rotating the work. However, the distance between the inspected portion of the workpiece and the magnetic sensor is always kept constant, and the presence or absence of cracks can be detected accurately and in a short time.

[Brief description of the drawings]

FIG. 1 is an overall process diagram of a gear manufacturing apparatus incorporating an automatic magnetic inspection apparatus according to the present invention.

FIG. 2 is a plan view of an automatic magnetic flaw detection station.

FIG. 3 is a front view of the automatic magnetic flaw detector according to the invention of claim 2;

FIG. 4 is an enlarged view of a main part of FIG. 3;

5 (a) to 5 (c) are front views for explaining the operation of the automatic magnetic flaw detector shown in FIG. 3;

FIG. 6 is a plan view of a reference automatic magnetic flaw detector.

FIG. 7 is a front view of the automatic magnetic flaw detector according to the first embodiment;

8 is an enlarged view of a main part of FIG. 7;

FIG. 9 is a front view of the automatic magnetic flaw detector shown in FIG. 7 in a standby state;

[Explanation of symbols]

18: Magnetic flaw detection station, 22: Inspection unit, 30, 5
0, 70, 80 ... magnetic flaw detector, 33, 38, 73, 8
3. Air cylinder unit, 34, 52, 74, 84 ...
Follower, 39: linked body, 35, 75, 85: roller, 4
1, 56, 77, 87: magnetic flux detection sensor, 54: head part, 55: copying surface, S1: first inspection station, S2
... Second inspection station, W. Work (gear).

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-91552 (JP, A) JP-A-5-240840 (JP, A) JP-A-5-223789 (JP, A) 60510 (JP, A) Japanese Utility Model Showa 60-93960 (JP, U) Japanese Utility Model Application Hei 5-94760 (JP, U) Japanese Utility Model Application Utility Model Hei 6-2217 (JP, U) (58) Fields surveyed (Int. ⁶ , DB name) G01N 27/72-27/90

Claims (2)

(57) [Claims] 1. A automatic magnetic flaw detector for inspecting the presence or absence of flaws such as cracks while rotating the workpiece, the automatic magnetic flaw detector, respectively upper and lower pairs of two support members which moves back and forth from the side of the workpiece Mounted and rotated in
And each pair of the follower which moves in response to the planar portion of the front and back touch the flat portion due to the rotation of the contact work of the workpiece, the first workpiece
The distance between the first and the flux detecting sensor for the inspection section inspecting the gap between the inspection unit is fitted each to one pair of the follower so as to be constant, a second inspection portion of the workpiece is constant The second members respectively attached to the other pair of the followers so that
An automatic magnetic flaw detector comprising: a magnetic flux detection sensor for inspecting an inspection unit . 2. An automatic magnetic inspection apparatus for inspecting the presence or absence of a crack or the like while rotating a work, wherein the automatic magnetic inspection apparatus comes into contact with a plane part of the rotating work and touches the plane part accompanying the rotation of the work. A follower that moves in accordance with, a linked body that partially abuts the follower and interlocks with the follower, and a magnetic flux detection sensor attached to the linked body so that the distance between the inspected portion of the work is constant. An automatic magnetic flaw detector comprising: