JPS63261154A - Normal/abnormal deciding method for cylinder flaw detection system - Google Patents

Abstract

PURPOSE:To obtain a system which performs flaw detection automatically as to corrosion nearby the skirt base part of a cylinder and decides properly whether or not the cylinder is normal by deciding whether or not the depth and length of the corrosion measured by an ultrasonic probe are within a specific range. CONSTITUTION:While the cylinder 1 is rotated, the flaw detection is carried out as to a flaw detection area inside the skirt 2. The length of the corrosion in the circumferential direction is calculated by a corrosion state calculation processing block 11 by using the rotation of the cylinder 1 detected by a rotary encoder (RE) 8. Further, the depth of the corrosion is calculated by the block 11 by using the echo intensity of the ultrasonic wave from the main probe 6a and the length of the corrosion detected by the RE 8. Then a normal/abnormal decision processing block 12 decides that the cylinder is normal when the measured corrosion depth (ratio of corrosion depth to plate thickness) and corrosion length are within a nearly rectangular are encircled with constant corrosion depth D1 and constant corrosion length L1, and determines an abnormal area outside a border line which runs nearby coordinates (L1, D1) and reaches corrosion length L2 and corrosion depth D2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pass/fail determination method for a cylinder flaw detection system 110 that detects corrosion in a horn for LPG or the like.

(Prior Art) Conventionally, corrosion is most likely to occur in the area near the base (particularly the inner side) of the skirt at the bottom of the pan due to the operating environment and structure of phones for LPG and the like.

Corrosion in this area is a safety issue (visual inspection is required by the standards, but since it is at the base of the skirt, there is a high risk of missing it due to a blind spot), and even if it is discovered, it is impossible to measure the amount of corrosion. At present, this is close to possible.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems and provides a pass/fail judgment for a cylinder flaw detection system that automatically detects corrosion near the base of a skirt and ensures pass/fail. The purpose is to provide a method.

(Means for Solving the Problems) In order to achieve the following two objects, the present invention firstly provides a method in which the corrosion depth and corrosion length measured by an ultrasonic probe are fixed at a constant corrosion depth D1 and If it is within a substantially rectangular area surrounded by the corrosion length I7°, it is considered to be a pass, and the above (1, +, D+)
This paper proposes a pass/fail determination method for a cylinder flaw detection system in which a cylinder flaw detection system is judged as a failure if it is outside a triangular area passing near the coordinates.

In order to achieve the following two objects, the present invention secondly provides a method in which the corrosion depth and corrosion length measured by an ultrasonic probe are a constant corrosion depth dl and a constant corrosion length L.

If it is within the approximately rectangular area surrounded by
This paper proposes a pass/fail determination method for a cylinder flaw detection system in which the cylinder flaw detection system is judged to be rejected if it is within an area outside the approximately triangular area passing near the (1, +, d'+) coordinates.

In order to achieve the following objectives, the present invention thirdly provides an echo intensity El and a constant corrosion length measured by an ultrasonic probe. , if it is within a substantially rectangular area surrounded by (Li,
Ei) We propose a pass/fail determination method for a cylinder flaw detection system in which the cylinder flaw detection system is judged as a failure if it is within an area outside a substantially triangular area passing near the coordinates.

(Operation) The method of the present invention has the structure described in the claims,
In particular, a constant corrosion depth DI (Fa corrosion depth dl or echo strength E,) and a constant corrosion length I-.

Since only the approximately rectangular area surrounded by the area is passed, only absolutely safe items can be passed.

The method of the present invention has the same configuration, especially (Ll, D
,) coordinates ((1, + , d+) coordinates or (1, l , E
(l) Coordinates) If it is within an area outside the approximately triangular area passing nearby, it will be rejected, so unsafe items can be reliably rejected.

(Example) The pass/fail determination method of the cylinder flaw detection system of the present invention will be described below according to an example shown in the drawings.

1 and 2 show an example of corrosion (5) of a cylinder (1) detected by the method of the invention.

That is, corrosion (5) inside the base of the skirt (2) of the cylinder (1) is detected.

Figures 3 and 4 illustrate the method of the invention with a single cylinder detector system 11 having a rotating drive roller (9) for rotating the cylinder (1).

The cylinder (1) is located inside the scar 1-(2) of the cylinder (1).
) is arranged in close proximity to the main probe (6a).

Next, an auxiliary probe (611) is placed outside the skirt (2) and close to the cylinder (1).

Further, a plate thickness sensor (7) or a cylinder (1) is placed at a suitable location away from the base of the skirt (2).

Next, a rotary encoder (8) for detecting the rotation of the cylinder (1) is provided in contact with the scarr 1-(2).

On the other hand, a flaw detection data sensitivity correction processing block (10) is provided, and the block (10) operates the main probe (6a) and the auxiliary probe p (6b) manually.

Next, a corrosion state calculation processing block (11) is provided, and in this one, the flaw detection cheater sensitivity correction processing block (10), the rotary encoder (8), and the plate thickness sensor (7) are manually operated. .

Next, a pass/fail judgment processing block (12) is provided, and this block (12) is connected to the corrosion state calculation processing block (11).
and the rotary encoder (8) as input.

Next, the judgment result by the pass/fail judgment processing block (12) is displayed on the display (13).

The operation of the pass/fail determination method for the cylinder flaw detection system of the present invention shown in the second embodiment is as follows.

In other words, the cylinder (1) is rotated by the rotary drive roller (9) while the cylinder (1) is being rotated by the flaw detection area (4) inside the skirt (2).
(See Figure 2) Corrosion (5) is detected.

Here, the circumferential length of the corrosion (5) is calculated using the rotation of the cylinder (1) detected by the rotary encoder (8).

Next, the depth of the corrosion (5) is calculated using the ultrasound echo intensity from the main probe (6a) and the corrosion length detected by the rotary encoder (8).

That is, the echo strength is affected not only by the depth of the corrosion (5) but also by the length of the corrosion (5) (the longer the length, the stronger the echo strength at the same depth).

Next, the surface roughness and curvature of the bottom of the cylinder (1), which the main probe (6a) is close to, are determined based on the usage condition of the cylinder (1),
+) (7) Types (10kg, 20kg, 50kg
(Refer to Figure 1).

This surface roughness and curvature are measured from the main probe (6a) to the cylinder (
1) Affects the ease with which ultrasonic waves can enter the plank.

For this purpose, the ultrasonic waves emitted from the main probe (6a) are received by the auxiliary probe (6b) outside the skirt (2), and the strength of the received waves is used as sensitivity correction data.

In other words, the intensity of the echo transmitted from the main probe (6a), reflected by the corrosion (5), and returned to the main probe (6a) is the intensity of the received wave received by the auxiliary probe (6b). Sensitivity is corrected by processing the image.

Next, the thickness of the cylinder (1) is measured by ultrasonic waves transmitted and received by a thickness sensor (7).

The ratio of the depth of corrosion (5) carved into the plate thickness is referred to as "corrosion depth", and the corrosion depth and corrosion depth are calculated by the corrosion state calculation processing block (11).

In other words, the sensitivity-corrected echo intensity in the flaw detection data sensitivity correction processing block (10) is the same as the corrosion (5
), the depth of corrosion (5) is calculated taking this into account.

Next, the corrosion depth is calculated from both data of the corrosion depth (5) and the plate thickness of the cylinder (1).

Next, whether or not the corrosion (5) of the cylinder (1) complies with safety standards depends not only on the depth of the corrosion and the depth of the corrosion.

In other words, corrosion occurs even if the depth of corrosion is shallow (5)
The length of the skirt (2) in the circumferential direction)
If the length is long, the safety standards will not be met.

Therefore, data on the corrosion depth, corrosion depth, and corrosion length are used to determine whether or not the safety standards are met in the pass/fail determination processing block (12).

FIG. 5 is a diagram illustrating the pass/fail determination method, and a substantially rectangular area surrounded by a certain corrosion depth D1 and a certain corrosion length Ll is defined as a pass area.

On the other hand, the corrosion length I- passes near the (I-+, o+) coordinates.
2 and the boundary line reaching the corrosion depth D2, and the area outside this line is defined as a failure area.

Although the boundary line is shown here as a straight line, this is for simplification and may be a curved line or an uneven line.

That is, a substantially triangular region passing near the (154, D+) coordinate is considered, and the region outside this region is determined to be a failure region.

Next, it is assumed that areas other than the above-mentioned pass area and fail area (shaded areas in FIG. 5) should be judged by a system other than this system.

Next, the judgment result by the pass/fail judgment processing block (12) is displayed on the display (13).

As described above, it is determined whether the corrosion (5) in the flaw detection area (4) (see FIG. 2), which is a certain area inside the skirt (2), complies with the safety standards.

In the pass/fail determination method of the present invention, corrosion depth is used in the above embodiments, but corrosion depth or echo intensity may be used in addition to this.

In this case, instead of the constant corrosion depth D1, a constant corrosion depth d or a constant echo height E is used as the criterion.

(Effects of the Invention) The embodiments of the cylinder flaw detection system 1 of the present invention are as follows, and the effects thereof are listed below.

(1) The method of the present invention has the structure described in the claims, in particular, a constant corrosion depth DI <corrosion depth d, or echo strength El ) and a constant corrosion length ■.

Since only the area within the approximately rectangular area surrounded by 1 is allowed to pass, only absolutely safe items can be passed.

(2) The method of the present invention has the same configuration, especially (l,
.

, D, ) coordinate (([1, dl) coordinate or (1, + , E
l) Coordinates) If it is outside the area of the approximately triangular shape that passes nearby, it will be rejected, so it is possible to reliably reject anything that is not safe.

[Brief explanation of the drawing]

FIG. 1 is a front view of a cylinder to be tested for flaws by the method of the present invention. FIG. 2 is an enlarged bottom view of part A of FIG. Figure 5 is a block diagram of the same system as above. 2 Niscart 4: Detection area 5: Corrosion 6a: Main probe 6b: Auxiliary probe 7: Plate thickness sensor 8: Rotary encoder 9 : Rotating drive roller 10 : Flaw detection cheater sensitivity correction processing block 11 : Corrosion state calculation processing block 12 : Pass/fail judgment processing block 13 : Display device

Claims (1)

[Claims] 1. Corrosion depth D_1 and constant corrosion length L_ with a constant corrosion depth and corrosion length measured by an ultrasonic probe
Pass/fail of the cylinder flaw detection system, which is judged to be a pass if it is within the approximately rectangular area surrounded by 1, and rejected if it is within the area outside the approximately triangular area that passes near the (L_1, D_1) coordinates. Judgment method 2: Corrosion depth d_1 and constant corrosion length L_ with a constant corrosion depth and corrosion length measured by an ultrasonic probe
Pass/fail of the cylinder flaw detection system where if it is within the approximately rectangular area surrounded by 1, it is passed, and if it is inside the area outside the approximately triangular area passing near the (L_1, d_1) coordinates, it is rejected. Judgment method 3: If the echo strength and corrosion length measured by the ultrasonic probe are within a substantially rectangular area surrounded by a constant echo strength E_1 and a constant corrosion length L_1, the product is passed. ,
A pass/fail judgment method for a cylinder flaw detection system in which the cylinder flaw detection system is judged as a failure if the area is outside the approximately triangular area passing near the (L_1, E_1) coordinates.