JPH0444254Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tube end detector for a high-pressure tube drawing device.

[Conventional technology]

High-pressure drawing is a pipe manufacturing method in which a high-pressure vessel containing a raw pipe is filled with lubricating oil at high pressure, and in this state the raw pipe is pulled out of the high-pressure container while being drawn. It is said that it can supply lubricating oil and has a great effect on improving processing efficiency and product quality. The basic structure of the high-pressure drawing device is explained with reference to FIG. 3. A core bar 2 is inserted through the inside of a cylindrical high-pressure container 1 with one end closed, and an inner surface regulating tool 3 such as a plug is positioned at the open end of the container. . The high-pressure container 1 has a structure that can be expanded and contracted in the axial direction, and the open end portion 4 is pressed against the back surface of the die 5.

The drawing operation begins with inserting the raw pipe P into the high-pressure container 1 from the open end 4. This raw tube charging is performed with the high-pressure container 1 axially contracted and the die 5 removed, or with the high-pressure container 1 evacuated outside the line. After loading the blank tube, the high-pressure container 1 is stretched in the axial direction within the line, the opening tip 4 is crimped to the back surface of the die 5 (the rear surface in the drawing direction), and the space between the inner surface regulating tool 3 and the die 5 is closed. The mouth of the raw pipe P is sealed, and the high pressure container 1 is filled with lubricating oil at a high pressure (for example, 1500 kg/cm ² ) necessary for drawing. Then, the raw pipe P is pulled out of the high-pressure vessel 1 from between the inner surface regulating tool 3 and the die 5.

In such a high-pressure drawing method, if the raw pipe is pulled out from the high-pressure container while the lubricating oil in the high-pressure container is kept at high pressure, the lubricating oil in the high-pressure container will be violently released from between the die and the inner surface regulating tool at that moment. gush. This squirt not only scatters lubricating oil around, but also makes a loud explosion noise, which significantly degrades the working environment. In addition, a portion of the ejected lubricating oil enters the inside of the pipe from the rear end after drawing, necessitating an extra removal process, increasing the number of processing steps, and accelerating the deterioration of the removal liquid such as trichlene.

Therefore, in the high-pressure drawing method, it is necessary to take measures to prevent oil from gushing out at the end of drawing. Among these measures, the most reliable one is to reduce the pressure of the lubricating oil to atmospheric pressure at the end of drawing, as shown in Japanese Patent Application Laid-Open No. 57-94418.

When the pressure of the lubricating oil is lowered to atmospheric pressure at the end of drawing, the portion drawn after the pressure drop becomes atmospheric pressure drawing and is usually cut off. In order to suppress the decrease in yield due to cutting, it is necessary to accurately detect the tail end of the raw tube before the die, guide the tail end of the raw tube with high precision to the vicinity of the die, and shorten the atmospheric pressure drawing part as much as possible. can be said to be effective.

[Problem that the invention attempts to solve]

However, since the raw pipe is housed in a thick-walled high-pressure container, it goes without saying that it is impossible to visually detect the end of the pipe, and it is impossible to detect the end of the pipe from outside the high-pressure container using electromagnetic, photoelectric, or radiation methods. Indirect detectors are also difficult to apply. It is thought that the only possibility of application remains is a contact-type direct detector that directly detects the tube end using a contactor inside a high-pressure vessel.

However, during drawing, the high-pressure container is filled with lubricating oil at a pressure of about 1500 kg/cm ² , so normally designed contact-type detectors are not suitable for sealing, especially the sealing of the rotating shaft of the contact. However, if sufficient sealing performance is attempted, the sealing resistance of the rotating shaft increases and the operation of the contactor is hindered. One method is to apply a large force to the rotating shaft that overcomes the seal resistance, which increases the force with which the contactor contacts the pipe surface, causing a problem of damaging the pipe surface.

The present invention provides a contact-type tube end detector for high-pressure drawing, which solves these problems and has a smooth contactor movement and a sufficient sealing property on the rotating shaft of the contactor. be.

[Means for solving problems]

By the way, in a contact-type tube end detector for high-pressure drawing, since the high-pressure container is filled with high-pressure lubricating oil, only the contactor is housed inside the container, and its rotating shaft extends outside the container. It is necessary to connect ancillary devices such as a rotation angle detection device to this, and to arrange all of the ancillary devices outside the container.

In this case, sufficient sealing performance must be provided between the rotating shaft and the housing, but if you try to provide sufficient sealing performance with the normally used V-packet or conical packing, the sealing resistance will increase. A large force is required on the rotating shaft,
There is a risk of damaging the pipe surface.

In this case, the rotating shaft does not rotate all the time, but only rotates at a small angle when detecting the tube end, so the inventors decided to use an O-ring as a sealing material, which has a small contact area with the rotating shaft. After focusing on this possibility and investigating the possibility, we found that a rotary shaft that passes through the housing at right angles to the direction of passage of the raw pipe is formed symmetrically in the axial direction with respect to the center of the raw pipe passage line, and that the rotary shaft is equipped with hydraulic pressure. If the housing and rotating support shaft are sealed with an O-ring while preventing the axial load from being applied, the inside of the housing will be filled with lubricating oil at a pressure of about 1500 kg/ ^cm2 , which is necessary for high-pressure drawing. It has been found that there is no oil leakage even when the contactor is operated smoothly.

The present invention was made based on this knowledge, and as shown in FIG. 14;
A rotating support shaft 16 that penetrates the housing 11 in a direction perpendicular to the raw tube passage line, is formed symmetrically in the axial direction with the raw tube passage line as the center, and is sealed between the housing 11 and the housing 11 with an O-ring 21.
, a contact 25 for the blank tube fixed at the center in the axial direction of the rotation support shaft 16 , a contact pressing device 26 and a rotation angle detection device 29 arranged outside the housing 11 and connected to the rotation support shaft 16 . The gist is a high-pressure drawing tube end detector comprising:

[Effect]

The high-pressure container for high-pressure drawing contains 1500 kg of lubricating oil.
Filled with high pressure of about ^cm2 . Since the housing 11 is also interposed in a high-pressure container, it is filled with lubricating oil at the same pressure. If the rotary support shaft 16 passing through the housing 11 has a stepped shape that is asymmetrical in the longitudinal direction of the shaft, as shown in FIG. Since a stronger axial load acts thereon, a portion to receive this load is required, and the sliding resistance between the pressure-receiving portion and the rotation shaft becomes large, which impedes the rotational movement of the rotation support shaft 16. However, as shown in FIG. 2 (b) and (c), if the rotational support shaft 16 has the same diameter or is symmetrical in the axial direction with respect to the raw pipe passage line even if there are steps, the rotational support shaft 16 will have the same diameter. No force is applied to deflect this in the axial direction. Therefore, the rotation support shaft 16 operates smoothly.

Regarding the seal between the housing 11 and the rotational support shaft 16, the V packing and conical packing conventionally used for the rotational support shaft have large contact resistance with the rotational support shaft 16, and are necessary for high-pressure drawing. When attempting to obtain sufficient sealing performance under pressure, smooth operation of the contactor 25 is not guaranteed even if the rotating support shaft 16 has a symmetrical shape as described above.

However, the O-ring 21 has a lower contact resistance with the rotational support shaft 16 than a V-packet or a conical packing, and if the rotational support shaft 16 is made into a symmetrical shape as described above and this O-ring 21 is used, both This synergy ensures smooth operation of the contactor 25 even under the pressure required for high-pressure drawing, and also provides sufficient sealing performance between the housing 11 and the rotating shaft 16, ensuring durability. Since the amount of momentum is small, a practically sufficient amount can be obtained.

〔Example〕

Figure 1 shows an example of a tube end detector implementing the present invention, where A is a longitudinal side view and B is a side view of A-A in Figure A.
A cross-sectional view taken along the line A, and C an enlarged view of the B part of the figure B.

The housing 11 has a structure in which three hollow blocks divided in the axial direction of the high-pressure container are fastened together with bolts 12, and the high-pressure containers 1, 1 are airtightly fitted at both ends, and the base tube is connected to the high-pressure containers 1, 1 and 1. Housing 11
It is designed to pass through the inside. Housing 11
An air vent 13 is installed on the top, and the housing 11
A hole 15 that communicates with the inner chamber 14 is opened and closed by a valve.

Two upper and lower horizontal rotation support shafts 16, 16 pass through the housing 11 at right angles to the passage line of the blank tube 7. The rotation support shaft 16 has the same diameter in the axial direction, the center part is exposed in the inner chamber 14, and both ends are connected to the housing 11.
exposed outside.

Sleeves 17, 17 are interposed between the housing 11 and the rotation support shaft 16. This sleeve 17 is inserted into the housing 11 from both sides, and its collar 18 is sandwiched between the housing 11 and a cap 19 fixed to the housing 11 to prevent it from coming off, and is also prevented from rotating by a screw 20. ing.

The outer circumferential surface and inner circumferential surface of the sleeve 17 are provided with a first
As shown in FIG.
2 are fitted, and the sleeve 17 and the housing 1
1 and the rotating support shaft 16 are sealed.

A through hole 23 is provided in the sleeve 17 and the housing 11, and a pressure switch 24 connected to the through hole 23 detects breakage of the seal portion.

A contactor 25 is fixed to the central exposed portion of the rotation support shaft 16 at right angles to the longitudinal direction of the shaft. This contact 25
is pushed out from the horizontal retracted position in the direction of the arrow by a cylinder 26 as a pushing device attached to the side of the housing 11. That is, the tip of the rod 27 of the cylinder 26 is connected to the rotation support shaft 16 via the arm 28, and as the rod 27 retracts, the contact 25 is driven in the direction of the arrow.

A rotation angle detection device 29 is connected to the side opposite to the cylinder of the rotation support shaft 16, and detects the rotation angle of the rotation support shaft 16 one by one.

In order to detect the tail end of a raw tube during high-pressure drawing using the tube end detector shown in FIG. do. As a result, the raw pipe is inserted into the housing 11.

When the raw tubes are loaded and the high pressure containers 1, 1 are sealed, lubricating oil is filled into the containers at high pressure and drawing is started.

By operating the cylinder 26 and retracting the rod before or during the start of drawing, the contact 25 protrudes into the inner chamber 14 and its tip is brought into pressure contact with the circumferential surface of the raw pipe. The rotation angle of the rotation support shaft 16 at this time is detected by the rotation angle detector 29 and stored.

While the raw pipe is passing through the housing 11, the rotation angle of the rotating shaft 16 does not substantially change.

As the drawing progresses, the tail end of the raw pipe reaches the inside of the housing 11 and passes the tip of the contact 25, whereupon the contact 2 that was pressed against the peripheral surface of the raw pipe is removed.
5 rotates until it comes into contact with a core metal (not shown). This rotation appears as a change in the rotation angle of the rotation support shaft 16, and by detecting this with the rotation angle detector 29, it is detected that the tail end of the blank pipe has passed the tip of the contactor 25. be done.

The tail end is detected by the labor of the die, the tail end is accurately guided to just before the die, the pressure of the lubricating oil in the high pressure container 11 is lowered to atmospheric pressure in this state, and the remaining portion is then drawn. As a result, there is no oil spouting at the end of drawing, and the portion drawn at atmospheric pressure can be limited to a very small amount, thereby suppressing as much as possible a decrease in yield due to removal of this portion.

[Effect of idea]

As is clear from the above explanation, the high-pressure drawing pipe end detector of the present invention has a contact that operates accurately under the harsh conditions of high-pressure drawing, and also provides sufficient sealing performance to its rotating shaft. This results in high performance in terms of both accuracy and durability.

[Brief explanation of drawings]

1A to 1C show an example of a tube end detector implementing the present invention, in which A is a vertical side view, B is a cross-sectional view taken along line A-A in A, C is an enlarged view of part B in B, and FIG. Figures 2A to 2C are explanatory views of the shape of the rotating support shaft, and Figure 3 is a schematic explanatory view of the high-pressure drawing device. In the figure, 1...high pressure vessel, 3...inner surface regulation tool,
5...Dice, 11...Housing, 16...Rotation shaft, 21...O ring, 25...Contact, 2
6...Contact pressing device (cylinder), 29...
Rotation angle detection device.

Claims (1)

[Scope of utility model registration request] A housing 11 is interposed in the axial direction of a cylindrical high-pressure container 1 for high-pressure drawing, and has an inner chamber 14 through which the raw pipe passes, and the housing 11 is penetrated in a direction perpendicular to the raw pipe passage line, A rotary support shaft 16 is formed symmetrically in the axial direction around the raw pipe passage line and is sealed with an O-ring 21 between it and the housing 11, and an element fixed to the center of the rotary support shaft 16 in the axial direction. A tube end detector for high-pressure drawing characterized by comprising a contactor 25 for the tube, a contactor pressing device 26 and a rotation angle detection device 29 arranged outside the housing 11 and connected to the rotational support shaft 16.