JPS62157722A - Inside polishing method for metal tube - Google Patents

Abstract

PURPOSE:To obtain a highly accurately polished face via combined polishing of electrolytic polishing and mechanical polishing by feeding an electrolytic polishing liquid through the opening of a metal tube in which a rotary shaft spirally wound with a polishing material such as felt is inserted and slidingly brought into contact with the inside. CONSTITUTION:For the polishing method, a polishing member 11 wound around a rotary shaft 12 is slidingly brought into contact with the whole inner periphery of a metal tube 13, and the metal tube 13 is connected to a positive electrode and the rotary shaft 12 to a negative electrode respectively. Under this condition, a motor 5 is driven, and a motor table 4 is reciprocated back and forth by a fixed small distance. A motor 9 is driven to rotate the rotary shaft 12, and a drive motor 16 is driven to rotate the metal tube 13 in the peripheral direction. A circulating pump 20 is operated to feed an electrolytic polishing liquid from an electrolytic polishing liquid receiving tank 18 to the front end opening of the metal tube 13 via a circulating pipeline 21. Accordingly, even a fine-diameter tube with an inner diameter of 20mm or less can be easily polished, and accurate polishing can be attained by combined polishing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for polishing the inner surface of a metal tube with high precision by a combined polishing of electrolytic polishing and mechanical polishing.

(Prior art and its problems) In recent years, with the development of the electronic industry, especially the semiconductor industry, metal tubes with highly precisely polished inner surfaces are required as piping for gas and liquid used in the manufacturing process.

In general, scale and scratches occur on the inner surface of metal pipes during the heat treatment and forming process during pipe manufacturing, and the surface roughness is 5 to 3.
Since the metal tube has an extremely rough inner surface of 0 μm, it is necessary to polish the inner surface in order to use such a metal tube as a pipe in the manufacturing process.

For this reason, a method of polishing the inner surface of the metal tube called honing has been used, but since this method uses a grindstone to polish the inner surface of the metal tube, the length of the metal tube that can be polished is There is a limit to the inner diameter, and although it is possible to honing a metal tube with a large inner diameter, even if the total length exceeds 4 m, separate polishing is not possible if the inner diameter is about a few cranes.

On the other hand, an electrolytic polishing method has been developed in contrast to such a polishing method using a grindstone, and for example, there is a method as disclosed in Japanese Patent Application Laid-Open No. 56-27737.

This method is an electrolytic composite polishing method in which the inner surface of the metal cylinder is polished by a combination of the elution action of the metal inner surface by an electrolytic solution and the abrasion action of an abrasive material. Since internal polishing is performed by inserting a stand or a rotating device for the abrasive material, similar to the honing process described above, only large-diameter metal cylinders can be polished, and small-diameter metal tubes cannot be polished by the equipment. This is not possible, and the abrasive material does not come into sliding contact with the entire length of the cylinder, but polishes the inner surface while moving the pedestal in the length direction of the cylinder, so it takes a long time to polish. There are problems such as time required.

The present invention provides a method for polishing the inner surface of a metal tube that solves these problems.

(Means for Solving the Problems) In order to achieve the above object, the method for polishing the inner surface of a metal tube according to the present invention includes inserting a rotating shaft around which a polishing member such as felt is spirally wound into the metal tube. The polishing member is brought into sliding contact with the inner surface of the metal tube, and in this state, an electrolytic polishing solution is supplied from an opening at one end of the metal tube, and the electrolytic Vr polishing solution is applied to the inner surface of the metal tube by rotation of the spiral polishing member. The metal tube is fed to the other open end while making sliding contact with the metal tube, and the inner surface of the metal tube is polished while reciprocating the rotary shaft relative to the metal tube by a small distance in the length direction of the metal tube. It is something to do.

(Function) When the rotating shaft around which the polishing member is spirally wound is rotated while supplying electrolytic polishing liquid from the opening at one end of the metal tube, electrolytic polishing is performed by the polishing member slidingly contacting the entire length of the inner surface of the metal tube. Electrolytic polishing is performed while the liquid is rubbed against the inner surface of the metal tube at a constant pressure, and the electrolytic polishing liquid is sent toward the opening at the other end of the metal tube by the rotation of the spiral polishing member, and further,
The inner surface of the metal tube is uniformly polished by small reciprocating movements of the rotating shaft in the length direction of the metal tube.

(Description of Embodiments) An embodiment of the present invention will be described with reference to the drawings. (1) is a machine base, on the upper surface of which horizontal guide bars (2) (2) are arranged in parallel in the front and back direction, and these guide bars ( 2) (21 is pivotally supported by bearings (3) (3) and the guide bar (21 is
+ (2) Place the motor stand (4) on the guide bar (2)
(2) It is arranged so that it can freely slide forward and backward.

(5) is a reciprocating motor placed inside the machine base (1),
A rotating shaft (7) is installed upright on the outer periphery of the rotary plate (6) fixed to the upper end of the rotating shaft, and the upper end of the rotating shaft (7) is connected to an oblong hole (8) bored in the motor base (4). ), and the reciprocating motor (5) is driven to cause the motor stand (4) to reciprocate in the front-rear direction by several centimeters to several centimeters.

A polishing member rotation motor (9) is installed on the motor stand (4), and a chuck α is attached to the tip of the rotating shaft of the motor that protrudes from the front of the motor. Polishing member (11) made of synthetic leather, etc.
) is removably gripped at the rear end of a rotating shaft (12) made of a thin metal rod or flexible metal wire wrapped in a spiral shape.

(13) is a small diameter metal tube to be polished;
The polishing member (11) is fitted onto the polishing member (11) wound around the polishing member (11) wrapped around the polishing member (11), and is brought into sliding contact with the polishing member (11) over the entire length of the inner circumferential surface thereof.

(14) is a rotating ring that is detachably fixed to the outer circumferential surface of an appropriate part of this metal tube (13), and a gear (15) is attached to the outer circumferential surface of the rotating ring.
A drive motor (16) is connected to this gear (15).
) is engaged with the pinion (17) which rotates slightly.

(18) is a tank whose upper end opening faces the rear end opening of the metal pipe (work 3), and its lower end outlet (19)
is connected and communicated with the circulation pump (20), one end of the circulation pipe (21) is connected to the discharge port of the circulation pump (20), and the other end opening of the circulation pipe (21) is connected to the discharge port of the circulation pump (20). It is designed to be removably and watertightly fitted onto the outer peripheral surface of the front end of the metal tube (13).

In addition, if a plurality of such devices are arranged as shown in FIG. 1, the inner circumferential surfaces of a plurality of metal tubes can be polished at the same time.

In this case, a single motor (9) that rotates the rotating shaft (12) of the polishing member (11) is connected to the pulley (22) and belt (2) from this motor (9) to the rotating shaft (12) of each device.
3) should be connected via a power transmission mechanism such as (,
In addition, the electrolytic polishing liquid receiver faces the upper end opening of the tank (18) below the rear end opening of all the metal pipes (13), and one circulation pump (20) is used to supply the circulation pipe (21). ) The ends of each branch pipe (not shown) branched from the metal pipe may be removably fitted into the front end of each metal pipe via an on-off valve (not shown).

Further, as the electrolytic polishing solution, a polishing solution containing a polishing portion made by uniformly mixing 10 to 40% by weight of alumina with a particle size of 0.5 to 10 μm to a known electrolytic solution containing nitric acid, sulfuric acid, etc. is used. .

Furthermore, the length of the metal tube (13) to be polished is not limited, but a small diameter metal tube with an inner diameter of 30H or less can be polished.
It is preferable that it is suitable for polishing.

Now, while putting the metal tube (13) over the polishing member (11) wrapped around the rotating shaft (12), place the polishing member (11) on the metal tube (
The inner circumferential surface of the metal tube (13) is brought into sliding contact with a constant pressure over the entire length, and the inner circumferential surface of the rotating ring (14) is pressed against the outer circumferential surface of the metal tube (13) by an appropriate means such as an expanding/contracting mechanism or an intervening member. The metal tube (13) is fixed in place, and the front end outer periphery of the metal tube (13) is rotatably inserted into the circulation conduit (21) for communication, and the metal tube (13) is used as an anode, and the rotating shaft (14) is connected to the circulation tube (21). Connect to the cathode respectively.

In this state, when each motor (51 (91 (16)) is rotated and the circulation pump (20) is driven, the reciprocating motor (5) drives the rotary plate (6) and the rotation shaft (
7), the motor stand (4) reciprocates a fixed short distance back and forth through the tube, and the polishing member (11) that slides in contact with the inner peripheral surface of the metal tube (13) integrally reciprocates in the length direction. The rotating shaft (12) rotates in the circumferential direction by the rotation of the motor (5) on the motor stand (4), and the metal tube (13) slowly rotates in the circumferential direction by the rotation of the drive motor (16). .

On the other hand, by the operation of the circulation pump (20), the electropolishing liquid in the tank (18) is sent into the front end opening of the metal tube (13) through the circulation pipe line 21).

When this electrolytic polishing liquid enters the metal tube (13), the rotating shaft (
12) impregnated or attached to the spiral polishing member (11),
The polishing member (11) is brought into sliding contact with the inner circumferential surface of the metal tube (13), electrolytically polishes the inner circumferential surface of the metal tube (13) in the circumferential direction over its entire length, and is mixed into the acid solution. The inner circumferential surface of the metal tube (13) is subjected to abrasion action by the alumina, mechanically polishing it, and the rotation of the spiral polishing member (11) causes the electrolytic polishing liquid to polish the inner circumferential surface of the metal tube toward the rear side. The receiver is transferred while flowing down from the rear end opening of the metal tube (13) and is stored in the tank (18). This receiver is a tank (18)
The electrolytic polishing liquid that has flowed down inside the tank (18) is circulated and supplied again to the front end opening side of the metal tube (13) by the circulation pump (20).

In addition, the metal tube (
The inner surface of 13) is polished uniformly in the length direction with an electrolytic polishing liquid.

This polishing work is performed continuously for an appropriate period of time to form a metal tube (13).
The inner surface is polished over its entire length to a maximum height roughness of 0.5μ or less.

In the above embodiments, a method for polishing a straight metal tube has been described, but the present invention is not limited thereto (it is also possible to polish a bent metal tube).

For example, as shown in FIG. 3, a chuck (33) is attached to the rotating shaft of a motor (32) that reciprocates up and down a short distance along a column (31), and a polishing member ( One end of a flexible metal linear object (35) formed by spirally winding 34) is held and the other end is tensioned by a spring (36). (35) is inserted into the bent metal tube (37), and the metal tube is fixed with an appropriate fixing means (not shown), and a funnel (35) is inserted into the upper end opening of the bent metal tube (37).
38) or the like, and in this state, the motor (32) is rotated and reciprocated up and down to polish the bent metal tube (37) in the same manner as described above.

The straight metal tube (13) is supported in a predetermined position by appropriate receiving means such as rollers.

(Effects of the Invention) As described above, in the method for polishing the inner surface of a metal tube according to the present invention, a rotary shaft on which a polishing member such as felt is spirally wound is inserted into the metal tube, and the polishing member is applied to the inner surface of the metal tube. sliding contact,
In this state, an electrolytic polishing liquid is supplied from the opening at one end of the metal tube, and by the rotation of the spiral polishing member, the electrolytic polishing liquid is sent out to the other open end while slidingly contacting the inner surface of the metal tube. The inner surface of the metal tube is polished while relatively reciprocating the rotating shaft by a small distance in the length direction of the metal tube, so the polishing member inserted into the metal tube is thin. Since the structure is wrapped around a rotating shaft, even a thin metal tube with an inner diameter of 20W or less can be easily polished.Moreover, the polishing member can be rotated with the polishing member in sliding contact with the inner peripheral surface of the metal tube. Since the metal tube is reciprocated, the inner surface of the metal tube can be mechanically polished uniformly in the circumferential and longitudinal directions, and the polishing member is in sliding contact over the entire length of the metal tube, compared to partial polishing methods. Polishing time can be significantly shortened and polishing can be performed with high efficiency.

Further, the inner surface of the metal tube is chemically polished by an electrolytic polishing liquid supplied into the metal tube from an opening at one end of the metal tube,
Combined polishing with the mechanical polishing described above enables highly accurate polishing.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a simplified plan view of the polishing apparatus, FIG. 2 is a simplified longitudinal sectional side view, and FIG.
The figure is a simplified longitudinal sectional front view showing another embodiment of the present invention. (1)...Machine stand, (4)...Motor stand, (5)...
・Motor for reciprocating movement, (9)...motor for rotating polishing member, (11)...polishing member, (12)...rotation shaft,
(13)...Metal pipe, (18)...Electrolytic polishing liquid receiver is tank, (20)...Circulation pump, (21)...Circulation pipe line. Nanbe 1 Hall δbe? :, 8 2pe 5 ha

Claims (3)

[Claims] (1) A rotating shaft on which a polishing member such as felt is spirally wound is inserted into the metal tube, and the polishing member is brought into sliding contact with the inner surface of the metal tube, and in this state, electrolytic polishing is performed from the opening at one end of the metal tube. The electrolytic polishing solution is supplied to the other open end of the metal tube while being in sliding contact with the inner surface of the metal tube by rotating the spiral polishing member, and further, the rotation axis is set relative to the metal tube by the length of the metal tube. A method for polishing the inner surface of a metal tube, characterized by polishing the inner surface of the metal tube while relatively reciprocating a small dimension in the direction. (2) The method for polishing the inner surface of a metal tube according to claim 1, characterized in that the electropolishing liquid supplied into the metal tube is circulated. (3) The metal tube according to claim 1 or 2, characterized in that the rotating shaft is made of a flexible metal wire material and the inner surface of the bent metal tube is polished. Internal polishing method.