JP4310562B2 - External turning method for thin-walled pipe workpieces - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for turning an outer surface of a thin pipe-shaped workpiece.
[0002]
[Prior art and problems to be solved by the invention]
When turning a thin wall pipe with a lathe at both ends, the inside of the pipe is hollow, so the influence of vibration from the lathe and the tool is large, and the rigidity of the thin pipe itself is low, and chatter vibration is likely to occur. Achieving accurate surface roughness has been difficult. In addition, the tendency was more remarkable when the thin pipe was further thinned and lengthened.
[0003]
Therefore, in order to solve such a problem, it is necessary to back up from the inside to suppress chatter vibration during turning. In the case of a thin-walled pipe-shaped workpiece where the inner diameter of the workpiece is uniform over the entire length, as an anti-vibration device for suppressing chatter vibration, the outer diameter is conventionally equal to the inner diameter of the workpiece and can be inserted into the workpiece. A round bar having a surface layer made of an elastic material was used. Further, a plurality of partial cylindrical bodies each having a shape obtained by dividing a cylinder having an outer diameter smaller than the inner diameter of the work into a plurality of circumferential directions and an outer surface layer formed of an elastic material are integrated with an elastic fastening ring. What was fastened to was used. In the latter anti-vibration device, all the partial cylindrical bodies move radially outward against the elastic force of the fastening ring and pressed against the inner peripheral surface of the workpiece due to the centrifugal force generated by the rotation during turning. Thus, chatter vibration during turning is suppressed.
[0004]
However, when a thin-walled pipe-shaped workpiece has reduced diameter portions at both ends, the above-described two types of vibration isolator cannot be inserted into the workpiece, and chatter vibration during external turning cannot be suppressed. is the current situation.
[0005]
The object of the present invention has been made in view of the above circumstances, and it is possible to suppress the occurrence of chatter vibration even when external turning is performed on a thin pipe-shaped workpiece having reduced diameter portions at both ends. The object is to provide an external turning method.
[0006]
[Means for Solving the Problems and Effects of the Invention]
The outer surface turning method of a thin-walled pipe workpiece according to the present invention comprises a plurality of round rod-shaped vibration-proofing devices for suppressing chatter vibration, wherein the thin-walled pipe-shaped workpiece is long in the longitudinal direction of the workpiece and the outer peripheral surface layer is formed of an elastic material The tool is placed so as to be continuously arranged along the entire inner peripheral surface of the thin pipe-shaped workpiece, and in this state, the outer surface of the workpiece is turned.
[0007]
According to the method of the present invention, the inner peripheral surface of the workpiece is arranged so that all the vibration isolators are continuously arranged along the entire inner peripheral surface of the thin-walled pipe work by the centrifugal force generated by the rotation during the turning process. A back-up force is generated by being pressed against, and chatter vibration during turning is reliably suppressed.
[0008]
And even if the workpiece is in the shape of a thin pipe having a reduced diameter portion at both ends, if the outer diameter of each vibration isolator is smaller than the inner diameter of the reduced diameter portion, each vibration isolator is passed through the reduced diameter portion. It can be inserted into the workpiece, and chatter vibration can be suppressed even when the workpiece is subjected to external turning. Therefore, highly accurate surface roughness can be achieved in the processed product. In addition, since the surface layer on the outer peripheral surface of the vibration isolator is made of an elastic material, even if the vibration isolator rotates within the workpiece, the anti-vibration effect is not impaired, and it is inserted into the workpiece or turned on the outer surface. Scratches on the inner peripheral surface of the workpiece during machining are prevented. In addition, by changing the number of vibration isolator, it can be applied to the external turning of workpieces having different inner diameters. In addition, when a workpiece is attached to or detached from a lathe, no setup work for vibration isolator is required, and no setup work is required during machining, making it easy to automate and unmanned machining, improving productivity. Contribute to.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0010]
FIGS. 1 and 2 show a stage before the outer surface turning is performed on the thin-walled pipe-shaped workpiece, and FIGS. 3 and 4 show a stage where the workpiece is subjected to the outer surface turning.
[0011]
As shown in FIG. 1 and FIG. 2, it is necessary to pass through one of the reduced diameter portions (W1) before the outer surface turning is performed on the thin pipe-shaped workpiece (W) having the reduced diameter portions (W1) at both ends. Insert a round rod-shaped vibration isolator (1) for suppressing chatter vibration into the workpiece (W). The vibration isolator (1) includes a mandrel (2) made of a solid metal rod having a circular cross section and an elastic material (3) covering the outer peripheral surface of the mandrel (2). The length of the vibration isolator (1) is slightly shorter than the length of the work (W) excluding both reduced diameter portions (W1). As the elastic material (3), for example, an elastomer made of rubber or synthetic resin is used. The number of anti-vibration devices (1) inserted into the workpiece (W) is such that the anti-vibration devices (1) are continuously arranged along the entire inner peripheral surface of the thin-walled pipe-shaped workpiece (W), that is, all When the anti-vibration device (1) is placed along the inner peripheral surface of the workpiece (W), all the anti-vibration devices (1) can be inscribed in the inner peripheral surface of the workpiece (W) and adjacent It is preferable that the numbers be such that the vibrating tools (1) are in contact with each other or close to each other with a slight gap. When the required number of vibration isolator (1) is inserted into the workpiece (W), the vibration isolator (1) accumulates in the direction of gravity.
[0012]
When the required number of anti-vibration devices (1) have been inserted into the workpiece (W), as shown in FIG. 3, the workpiece (W) is inserted into the spindle (4) and the chuck (5) at the tip of the headstock in the lathe. And the center (6) of the tailstock using the reduced diameter portion (W1), and in this state, the workpiece (W) is rotated by the cutting tool (7) while rotating the workpiece (W). . When the workpiece (W) rotates, all the vibration isolators (1) in the workpiece (W) are continuously arranged along the inner peripheral surface of the workpiece (W) by centrifugal force, and all the vibration isolators (1). Can be inscribed in the inner peripheral surface of the workpiece (W), and the adjacent vibration isolator (1) is pressed against the inner peripheral surface of the workpiece (W) (see FIG. 4). W) is backed up and chatter vibration is suppressed. Thus, a highly accurate surface roughness can be achieved in the processed product.
[0013]
In the above embodiment, the mandrel (2) of the vibration isolator (1) is made of a metal solid rod-like body, but may be made of a metal hollow tubular body. Furthermore, the material of the mandrel (2) can be changed as appropriate. Then, by changing the material and shape of the mandrel of the vibration isolator (1) according to the material and thickness of the workpiece (W) and the processing conditions, the backup force due to centrifugal force is changed as appropriate, and chatter vibration is generated. It can suppress more reliably.
[0014]
Further, in the above embodiment, the outer surface turning method of the workpiece (W) having the reduced diameter portion (W1) at both ends has been described, but the method of the present invention also applies to a thin pipe-shaped workpiece having an uniform inner diameter over the entire length. Applicable.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a state in which a vibration isolator is inserted into a thin-walled pipe-shaped workpiece in a stage before performing outer surface turning.
FIG. 2 is a cross-sectional view showing a state in which a required number of vibration isolator is inserted into a thin-walled pipe-shaped workpiece before the outer surface turning process.
FIG. 3 is a longitudinal sectional view showing a step of performing an external turning process.
FIG. 4 is a cross-sectional view showing a stage of performing an external turning process.
[Explanation of symbols]
(1): Round bar vibration isolator for chatter vibration suppression
(3): Elastic material
(W): Thin pipe work

Claims (1)

In the thin pipe-shaped workpiece, a plurality of round rod-shaped vibration isolator for suppressing chatter vibration, which is long in the length direction of the workpiece and the outer peripheral surface layer is made of an elastic material, is applied to the entire inner peripheral surface of the thin pipe-shaped workpiece. A method for turning the outer surface of a thin-walled pipe-shaped workpiece, wherein the outer surface of the workpiece is turned in this state, and the workpiece is turned in this state.

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