JPH0641941B2 - Automatic inspection system for inner surface of narrow tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is directed to automatic inspection of thin tube inner surface flaw detection for detecting flaws in both the circumferential and axial directions of the inner surface of a relatively thin tube used in a heat exchanger. It relates to the device.

(Prior Art) In general, the eddy current flaw detection method has been most commonly adopted as a means for preventing a leak accident by discovering various kinds of defects on the inner and outer surfaces of a metal thin tube of a heat exchanger. There is. However, in these methods, the coil of the probe is sent from one end of the capillary to the other end by compressed air,
Thereafter, the code is pulled back by scanning the person to pull out the probe. A high-frequency alternating current is sent to the coil of the probe when this is pulled out, and the change in the eddy current generated inside the metal of the thin tube is captured and analyzed for processing, and this is an inspection method that allows the size and nature of the defect to be known.

However, in these cases, the device itself becomes very large,
It has a drawback that it is inconvenient for operation and transportation due to its weight, and that the pulling back of the probe cord is a manual work, so the speed is slow and the efficiency is poor, and the accuracy is very poor.

(Problems to be Solved by the Invention) The present invention has the above-mentioned drawbacks, that is, it is difficult to obtain a stable speed and inspection data because the cord of the probe is manually pulled out, and the apparatus is downsized and operated. It solves the problem of considering the easiness and certainty of the probe cord, and forwards and reverses it on the drum that winds the probe cord, and sends it by the print motor that controls the speed, and automatically pulls it out quickly. The point is that it can be carried out accurately.

(Means for Solving Problems) In order to solve all the above problems, the present invention relates to a drum (1) for winding a cord (C) of a probe (P) in a machine casing (5).
And a guide cord shifter (A) for winding the cord (C) around the drum (1), and a pulley (B) for pulling the cord (C) out. A hollow chamber is provided inside the drum shaft (6) of the drum (1), and ball bearings (7) are provided at both ends.
(7) is provided, and the rotary connector is inside the hollow chamber.
Store (8) and connect the rear end of the cord (C). Further, at the end of the drum shaft (6), a belt motor (12) via a planetary gear reducer (9) and an electromagnetic brake (11) is attached to a print motor (10).
Is installed. The cord shifter (A) includes a belt wheel (15) and a screw shaft (1) through a planetary gear reducer (16).
7) is provided. The code (C) is attached to the screw axis (17).
A guide roller (13) for moving up and down is installed. Also,
The pulley (B) has a belt wheel (19) that meshes with the belt (14).
Through the bevel gear (20) and the powder clutch (25)
Connected to. Output shaft (21) of this powder clutch (25)
, A driving wheel (18) is provided, and a freely rotatable friction roller (22) at a corresponding position is provided with an arm rod and a tension spring (23) which is pressed against the cord (C) is attached, The above object is achieved by connecting the probe (P) to the tip of the cord (C).

(Embodiment) An embodiment of the present invention will be described below with reference to an embodiment shown in the drawings. In FIG. 1, (A) guides a cord (C) of a probe to be wound around a drum (1). Cord shifter, (B) shows a pulley that pulls out the cord (C), (P) is a probe connected to the tip of the cord (C), and (H) is an air conduit. is there.

Machine frame constructed by panels such as aluminum
Inside the (5), the drum (1), the guide code shifter (A) for winding the drum (1) in an orderly manner, and the cord
It houses the three components of the pulley (B) that pulls out (C). The drum (1), the cord shifter (A), and the pulley (B) of these drums are designed to be simultaneously rotated in the normal and reverse directions by one print motor (10).

The probe (P) is connected to the tip of the cord (C) fed into the thin tube, and the tip of the cord (C) is inserted into the air pistol (2) connected to the conduit (H). There is.
Further, an electromagnetic valve (3) for operation and a pressure reducing valve (4) from an air source are installed in the conduit (H).

The drum shaft (6) of the drum (1) has a hollow chamber inside and both ends thereof are supported by ball bearings (7) and (7). A rotary connector (8) is installed in the hollow chamber. This rotary connector (8) has a drum
The rear end of the cord (C) of the probe wound around (1) is connected and connected to a flaw detector (not shown) for pulling out from the drum (1) and out of the machine. This rotary connector (8) is a slip ring having a special contact, and it is possible to prevent contamination of impure noise that cannot be avoided by a normal slip ring.

The output shaft of the print motor (10) is connected to the drum shaft (6) and the planetary gear reducer (9), and the output shaft of the motor (10) is equipped with an electromagnetic brake (11), A belt wheel (12) with tooth profile is attached to the back side.

The chord shifter (A) drums the chord (C) in an orderly manner.
In order to wind it around (1), the cord (C) is held between two guide rollers (13) (13) which are vertically upright, and the drum (1) is
When rotated, the drum shaft will have a length equal to the diameter of the cord (C).
It is a mechanism that moves in parallel with (6). For this reason, the cord (C) is prevented from being unbalanced or being superposed.

Next, since the cord (C) is wound around the drum (1) in three or four layers, the cord shifter (A) has a width of 1.
The motor (1
From (0) to the belt (14) with tooth profile, the cord shifter
After passing through the belt wheel (15) at the end of (A), the planetary gear reducer (1
6) and the screw shaft (17) are connected.

The screw shaft (17) is provided with an endless guide groove, and the two guide rollers (13) (13) of the shifter (A) reciprocate vertically by the endless guide groove.

Next, in FIGS. 1 and 2, the pulley (B) for pulling out the cord (C) has a belt wheel (19) meshing with the belt (14).
The belt pulley (19) is connected to the powder clutch (25) through a bevel gear (20). The output shaft (21) of the powder clutch (25) has a driving wheel (18).
It is attached. A rotary encoder (24) is connected to the end of the shaft of a rotatable friction roller (22) corresponding to the driving wheel (18). Also,
The friction roller (22) is pressed against the wheel (18) by a tension spring (23) against the arm rod in order to move the cord (C) while constantly pressing the cord (C). In addition, this friction roller (2
The rotation speed of 2) measures the length of movement of the cord (C).

When the cord (C) is pulled out, the powder clutch (25) transmits rotation as an ordinary clutch, but when it is fed, it operates like a semi-clutch. That is,
Drum due to change in feed rate due to fluctuation of air pressure and inertia
The code in the machine frame (5) due to the unwinding speed change of (1)
(C) softens that it is loosened or refused, and when it is sent,
Regardless of when it is pulled out, it always applies appropriate tension to the cord (C). That is, in order to ensure speeding up and speeding down in the initial and final stages of feeding and withdrawing, the motor is made to respond quickly to the speed control of the motor. The print motor 10 is a DC servo motor, which can freely perform forward / reverse rotation, start, stop, and speed control.

Further, the moving length of the probe (P) is set by converting the length of the metal capillary to be inspected, that is, the rotation speed of the friction roller (22) through the probe (P) into a pulse by the rotary encoder (24). , A computer (not shown) to store. Based on this, positioning is performed from acceleration to constant speed, deceleration, stop, etc., and operation commands related to the movement of the probe (P) are issued from the computer.

(Operation) Next, the method of using the automatic inspection device for the inner surface of the thin tube of the present invention will be described. The basic operation of the probe carrier is infeed and withdrawal, and the friction roller (22)
The length of movement of the cord (C) is measured in advance by rotating. Then, insert the probe (P) into the thin tube inlet for inspection, apply the air pistol (2) to the tube inlet, open the solenoid valve (3) by operating the push button switch, and insert the probe (P) into the piston. To do. At this time, the motor (10) rotates the cord (C) of the drum (1) in the returning direction. Code (C) is for screw axis (17)
By moving the guide roller (13) up and down
(1) Put it back in a more orderly manner, driving wheel on the pulley (B)
It stops when it passes between (18) and the friction roller (22) and reaches the end of the capillary together with the probe (P). Next, when pulling out, the pulling speed of the motor (10) is preset, and the cord (C) of the probe (P) is wound around the drum (1). At this time, the belt (1) installed on the belt wheel (12) of the motor (10)
The rotation of 4) causes the belt roller (15) to rotate the speed reducer (16) and the screw shaft (17) to move the guide roller (13) up and down to wind the cord (C) into the drum (1) in an orderly manner. It is a waste. The motor (10) stops when the pulled probe (P) comes back to the outlet port. At this time, the cord (C) connected to the rotary connector (8) of the drum shaft (6) of the drum (1) is pulled out of the machine frame (5) through the connector (8) and the flaw detector (Fig. (Not shown), an electric signal is recorded and recorded on a recording paper such as a recorder, and the recording paper is used to facilitate the check. The flaw detection operation device is not limited to the illustrated example, and includes various modifications.

Further, the embodiment of the present invention can be roughly classified into three types, that is, all or part of the above-mentioned operations is carried out by an automatic system, or all of them are carried out by a manual system.

(1), Fully automatic method Automatically perform from sending to completion of withdrawal, apply the air pistol (2) to the narrow tube mouth, press the switch,
It doesn't keep pushing. Switch is an air pistol
In addition to (2), the dial is also placed on the side of the flaw detector main body, and the dial for setting the speed of the moder, that is, the drawing speed (digital display) is also included in the same case. The speed of the probe (P) feed varies depending on the pressure of the compressed air at the site, so the pressure reducing valve
The feeding speed is controlled by controlling the speed of (4) and the motor (10). Motor control during delivery is carried out by the side of the carrier.

(2) Semi-automatic operation When the operation switch is turned on, the feeding or withdrawing operation is automatically started, and when it is completed, it stops. You don't have to press and hold the switch. The machine decides whether to send it in or out depending on the position of the probe (P).

(3), Manual method Start (feed / draw) stop and forward / reverse operation are performed by the operation of the switch. The operating switch is the push button switch provided on the air pistol (2), but the feed, draw, motor The selection of forward and reverse rotation of is done by another switch.

(Effects of the Invention) As described above, according to the automatic inspection apparatus of the present invention, the operation of inserting and withdrawing the probe is extremely easy and convenient, and the weight of the apparatus can be remarkably small and lightweight. There is an effect that it can operate at a high speed and a constant speed. In addition, as compared with the conventional work, the efficiency is remarkably improved as compared with the human work of pulling out by human power, and the time required for the inspection can be greatly shortened, and the inspection data are stable and there is no error. The machine frame has a drum that winds up the cord of the probe, a cord shifter that guides the cord in an orderly manner, and a pulley that pulls out the cord. Since the belt shifter and belt are operated without occupying them, there is no fear that the drive will be accurate and stable and a failure will occur, and the cord shifter operated by the belt will accurately guide the cord up and down. Therefore, the effect of orderly winding and unwinding the cord parallel to the drum and the effect that it accurately guides the movement of the cord and does not overwhelm the pulley, and it moves forward and backward reliably. Has an excellent effect.

[Brief description of drawings]

FIG. 1 is a front view of the apparatus of the present invention, and FIG. 2 is an enlarged plan view of a main part. The code (A) is a code shifter, (B) is a pulley, (C) is a code, (P) is a probe, (H) is a conduit, (1) is a drum, (2) is an air pistol, and (3) is an electromagnetic. Valve, (4) pressure reducing valve, (5) machine frame, (6) drum shaft, (8) rotary connector,
(9) and (16) are planetary gear reducers, (10) is a print motor, (11) is an electromagnetic brake, (12), (15) and (19) are belt wheels, (13) is a guide roller, ( 14) is a belt, (17) is a screw shaft, (18) is a driving wheel, (22) is a friction roller, (24) is a rotary encoder, and (25) is a powder clutch.

Claims (1)

[Claims] 1. A drum (1) for winding a cord (C) in a machine casing (5).
And a guide cord shifter (A) for winding the cord (C) around the drum (1), and a pulley (B) for pulling out the cord (C). ) Drum shaft (6) is provided with a hollow chamber inside, and ball bearings (7) and (7) are provided at both ends, and the rotary connector (8) is housed inside the hollow chamber and the rotary connector is A belt wheel (12) is connected to the rear end of the cord (C) to (8), and to the end of the drum shaft (6) via a planetary gear reducer (9) and an electromagnetic brake (11). Print motor provided
(10) is installed, the cord shifter (A) is provided with a belt wheel (15) at the end, and a screw shaft (17) is provided through a planetary gear reducer (16). In (17),
A guide roller (13) for moving the cord (C) up and down is installed,
The pulley (B) has a belt wheel (19) meshing with the belt (14).
The belt clutch (19) is connected to the powder clutch (25) through the bevel gear (20), and the powder clutch (2
A driving wheel (18) is provided on the output shaft (21) of 5), and a freely rotatable rotation roller (22) is provided at the corresponding position, and an arm rod is provided at the friction roller (22). An automatic inspection device for an inner surface of a thin tube, characterized in that a tension spring (23) which is pressed against the cord (C) is attached, and a probe (P) is connected to a tip of the cord (C).