JPS61209801A - External periphery turning device - Google Patents

Abstract

PURPOSE:To machine the external peripheral surface of cylindrical or bar shaped workpiece of small diameter and long length with high accuracy from a desired position by advancing and retracting the tool holder provided to a main spindle by means of an infeed controlling mechanism during the rotation of the main spindle moving on a slide guide and penetrated by a workpiece. CONSTITUTION:A main spindle 14 and a bracket 40 having respectively collet sections 37a and 42a opened and closed by the force of the fluid pressure to fluid pressured chambers X, Y, X', and Y' are provided on the slide base 10 and travels on a slide guide 2 through a male screw cylinder 60. The main spindle 14 has a tool holder 22 moving in the radial direction of the main spindle by means of a stopper shaft 25, coil spring 26, roller 29, the end taper section 28a of a slide cylinder 28 moved by a motor 34 for infeed drive, and so on. The collet sections 37a and 42a are opened to be inserted by a work-piece (a) and then closed to certainly hold it. The external peripheral turning of a member of small diameter and long length, therefore, even if it is such a special shaped workpiece as having ribs, can be performed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention #'i relates to an outer circumferential turning device for turning the outer circumferential surface of a long, small-diameter round bar or cylindrical workpiece from an arbitrary position.

<Prior art> As heat transfer tubes for heat exchangers used in thermal power plants, etc., long and small diameter drawn tubes with ribs are known. It is processed into a cylindrical Iζ shape without ribs.

Equipment for machining part of the outer circumferential surface of long, small-diameter tubes or rods, such as the heat exchanger tubes of this heat exchanger, include a proach machine using a broach, a key seater equipped with a single cutting tool, etc. is used. The number of teeth of the broach and the length of the broach are determined according to the size of the broach, the cutting shape of the workpiece, and the cutting amount I, and the workpiece is machined into a predetermined shape with one cutting stroke. or.

In 1,000-theta, the number of cuts of one cutting tool is determined according to the depth of cut into the workpiece, and the workpiece is machined into a predetermined shape. In machining using this broaching machine and key sheeter, the cutting process is performed by moving the blade from the cutting end side of the workpiece to the other end side, but in this case, the cutting edge of the cutting tool is The cutting edge is cut before the cutting edge touches the cutting edge.
The cutting edge cuts the material when it is pulled out.

<Problems to be Solved by the Invention> When the workpiece is small in diameter and long, cutting rotation, shaping, etc. become extremely difficult, resulting in a decrease in machining accuracy and extremely poor work efficiency. For this reason, there is a strong desire for a cutting device that can precisely machine any part of the outer circumferential surface of a small-diameter, long workpiece.

Based on this knowledge, it is an object of the present invention to provide an apparatus that can turn the outer circumferential surface of a special-shaped small-diameter elongated material such as a long and small-diameter ribbed heat exchanger tube from any position with high precision. .

<Means for Solving the Problems> The present invention provides a bed having a slide guide, and a workpiece fixing device provided at one end of the bed to hold a long workpiece parallel to the slide guide and immovable. a sliding chuck that is moved on the bed via the feeder 111 using the slide guide, and a sliding table that is attached to the sliding table so that the workpiece passes through the center and is driven for turning. A cylindrical main shaft rotationally driven by a motor, a tool holder supported by the main shaft to which a cutting tool is fixed and movable in the radial direction, and the pie and tool holders are moved forward and backward during rotation of the main shaft. With the cutting depth control mechanism.

A pair of workpiece supports are supported by the slide table and slidably support the workpiece.

Function: A small-diameter O long workpiece is held immovably by a workpiece fixing chuck with the center of the cylindrical main shaft passing through, and the workpiece is held by a workpiece support provided on a sliding table. When the workpiece is held and slid on the slide guide while rotating the main shaft in this state, the workpiece support slides along the workpiece while holding the workpiece. Then, at the required machining position, the cutting control mechanism gives the cutting tool holder ζ movement in the cutting direction.

When the cutting tool is cut by a certain length, the cutting tool turns the outer peripheral surface of the workpiece to a certain depth and is sent in the longitudinal direction of the workpiece as the slide table moves.

The outer peripheral surface of the workpiece is turned with high precision.

<Example> First example showing the appearance of an example of the outer circumferential turning device according to the present invention.
As shown in the figure, a linear slide guide 2 is provided on the bed 1.

One end side of this slide guide 2 has a workpiece clamping section A.
is located. Further, a turning head part B is slidably mounted on this slide guide 2, and a turning head part B is slidably mounted on this slide guide 2.
A feed mechanism section C is located on the other side.

The workpiece clamping part A is for holding a long and small diameter workpiece a (-) such as a ribbed heat exchanger tube in a fixed state, and as shown in FIG. A mounting bracket 3 is fixed to one end.A collet chuck 4 constituting a fixing chuck for fixing the workpiece a at a predetermined height is attached to the center hole 3a. This collet chuck 4 has a tapered hole 5a in the collet chuck body 5.
It has a structure in which the collet 6, which is divided into four parts, is rotated through the half-moon center -7 and incorporated together with a ring spring 8, and the machining is carried out by the operation of the hydraulic pistons ga and gb facing each other with the collet 6 in between. I am trying to clamp or unclamp object a.

As shown in FIG. 3, which shows an enlarged cross-sectional structure of the turning head part B, a slide table 1 is slidably placed on a slide guide 2.
The turning head 12 is supported through a support cylinder 118. This turning head 12 is supported by a ball bearing 13a.

A cylindrical main shaft 14 is rotatably fitted through the main shaft 13b, and a gear 14a is integrally formed on the outer periphery of the main shaft 14, and a drive transmission gear 15 meshes with the gear 14a. The drive transmission gear 15 is supported by a bearing cylinder 16 fixed to the upper end of the support cylinder 11 via ball bearings 17a and 17b.
The drive shaft 18 is non-rotatably mounted with a key 19 to the drive shaft 18, which is connected to the rotation shaft 20 of the drive motor 20.
a via a shaft coupling 21. Main shaft 1
A cutting tool holder 22 is attached to the front end of the main shaft 14. A workpiece insertion hole 22a is formed in the center of the cutting tool holder 22, and a guide recess 23 formed in the front end surface of the main shaft 14.
Insert into rL.

It is movable in the radial direction (vertical direction in the figure).

A cutting tool 24 is fixed to the front surface of this cutting tool holder 22 toward the center of the main shaft 14, and a threaded portion 25a of a stop shaft 25 is screwed into a part 180 degrees opposite thereto. This stop shaft 25 penetrates 14% of the main shaft in the radial direction, and urges the cutting tool holder 22 downward by a coil spring 26. Due to the elastic force of the coil spring 26, the cutting tool 24 cuts into the workpiece a with the flange 25b of the stop shaft 25 in contact with the inner wall of the guide recess 23, and the screw portion 25 against the tool holder 22
The depth of cut fM can be determined by the screw-in amount of 3. A cutting control mechanism for moving the cutting tool holder 22 in the radial direction is provided inside the main shaft 14), and this cutting control mechanism is locked by a sliding key 27 on the inner peripheral surface of the support cylinder 11. It has a sliding tube 28 that is slidable in the axial direction (left-right direction in the figure). A tapered portion 28a having a tip m9 is formed at the tip of this sliding tube 28.C1 This sliding tube 2
8 to the right side in the figure, the tapered part 28a
A roller 29 is rotatably provided in the tool holder 22.
When the tool comes into contact with the workpiece a, the tool holder 22 is slid in the guide recess 23 against the coil spring 26 in the direction in which the tool 24 retreats with respect to the workpiece a.

A male threaded portion 28b is carved on the outer surface of the sliding tube 28.
A female threaded tube 30 is rotatably screwed into this male threaded portion 28b. This internally threaded cylinder 30 is rotatably supported by the support cylinder 11 via a bearing bush 31.9. Support tube 11
Movement in the axial direction is prevented by the thrust plate 32 which is screwed to. Furthermore, a gear 33 is integrally formed on the outer periphery of the female threaded cylinder 30, and a gear 35 fixed to a rotating shaft 34a of a cutting drive motor 34 meshes with this gear 33. Therefore, due to the rotation of the cutting drive motor 34, the internally threaded cylinder 30 rotates, and the sliding cylinder 2 is screwed into the internally threaded cylinder 30.
8 slides in the axial direction and the tapered portion 28a at its tip advances and retreats, thereby causing the bite holder 22 to reciprocate in the cutting direction. A first workpiece support 36 is provided inside the sliding tube 28, and this workpiece support 36 is slidably fitted onto the inner peripheral surface of the sliding tube 28 along the axial direction. It has a collet piston 37. The collet piston 37 is slidably housed in a cylinder portion 28c formed on the rear end side of the sliding tube 28 in an airtight state.
, by alternately injecting pressure fluid into a pair of fluid pressure chambers X and Y formed before and after the shaft, reciprocating in the axial direction. A collet portion 37m is integrally formed at the tip of the collet piston 37, and a guide bushing 38 is fitted on the inner peripheral surface of the collet portion 37m. Therefore, the collet portions 37a/d, ? J*fm 28 taper part 2
The diameter of the guide bush 38 is compressed by pressing the guide bush 38 into the guide bush 8a, and the workpiece a inserted therein is held slidably in the axial direction. The upper part of the sliding table 10
A second workpiece support 39 located at the front side of the turning head 12 is attached to c. This workpiece support 39 is a support cylinder 41 installed on the slide table 10 via a bracket).
A cylinder 411 is formed on the inner surface of this support vJ41, and a collet piston/42 is slidably inserted into this cylinder 418. By alternately injecting, reciprocating operation is achieved. On the other hand, the support tube 41
A tapered part 41b is formed on the inner surface of the end on the side of the turning head, into which the collet part 42a at the tip of the collet piston 42 is inserted. A guide bushing 43 is inserted into the collet portion 2a, and the collet portion 42a
is pushed out into the tapered portion 41b and the diameter is reduced by the diameter ξ.

The diameter of the guide bush 43 is reduced n, and the workpiece a passing through the center of the guide bush 43 is slidably held therein.

As shown in FIG. 4, which shows an enlarged cross-sectional structure of the feeding mechanism section C, a bearing cylinder 52 is installed coaxially with the workpiece insertion hole 50a of the feeding support stand 50 set up on the bed 1 via a bolt 51. The ball bearing 53a is fixed in the bearing sleeve 52.

A female threaded cylinder 54 for multi-feeding is rotatably supported via 53b. A pulley 56, which is prevented from rotating by a key 55, is fitted onto the outer periphery of the female thread cylinder 54. An endless belt 59 is hooked between a pulley 58 fixed to a rotating shaft 57a, and the female threaded dragon 54 is rotated by the drive of the feed drive motor 57. A female threaded portion 54a is formed on the inner surface of the female threaded cylinder 54, and a male threaded cylinder 60 having a male thread 60a formed on its outer periphery is screwed into this female threaded portion 54a. One end of this male threaded cylinder 60 is fixed via a bolt 61 at the end of the support cylinder 41 of the second workpiece support 39, and the workpiece a is inserted inside the bolt 61. Then, the feeder drive motor 578
By driving and rotating the female screw 1m54, the male screw tube 60 moves in the left and right direction in the figure, so the sliding base 10
slides on the slide guide 2.

During turning, firstly, the fluid pressure piston 9af of the workpiece clamp section A is operated, and pressure fluid is supplied to the fluid pressure chambers X and XI sides of the two workpiece supports 36 and 39 of the turning head section B to move the collet. Open parts 37a and 42a. Furthermore, the cutting drive motor 34 is rotated in the forward direction to rotate the sliding tube 28.
8 into the cutting tool holder 22, and the cutting tool 24 is moved back together with the cutting tool holder 22 against the coil spring 26. In this state, the workpiece a is inserted into the collet 6 of the workpiece clamp part A, and is inserted into the male threaded cylinder 60 from the collet piston 42 in the sliding cylinder 28 of the turning head part B through the collet parts 37a and 42a. Thereafter, the fluid pressure piston 9b of the workpiece clamping section A is operated to reduce the diameter of the collet 6, holding the workpiece a non-slidably, and also opening the fluid pressure chambers Y, Yl of each workpiece support 36, 39. Pressure fluid is supplied to the collet portions 37a and 42a to reduce their diameters and hold the workpiece a through the guide bushes 38 and 43'E. When the drive motor 20 is operated in this state to rotate the main shaft 14, the cutting tool 24 rotates around the workpiece a.

Then, operate the feed drive motor 57 to remove the female screw $54.
The cutting drive motor 34 is rotated in the reverse direction while feeding the slide table lO through the male screw @60, and the slide tube 28 is rotated.
When the tapered part 28a of the tip 1 and the roller 29 in the cutting tool holder 22 are moved back until they are in a non-contact state, the cutting tool holder 22 gradually protrudes in the cutting direction by the coil spring 26, and the workpiece at this time As shown in FIG. 5 showing the processing state of workpiece a and FIG. 6 showing the cross section taken along the arrow M-■, workpiece 3 is machined at an angle θ with respect to the rib al formed on the outer peripheral surface of workpiece a. Continuous turning to diameter. and.

Further, the feeding operation and the turning operation are continued ξ, and the tool holder 22 is energized until the stop shaft 2507 flange 25a is in contact with the inner surface of the guide recess 23 by the coil spring 26, and the machining diameter is increased to the final end of the turning operation. The accuracy is maintained as it is (no turning process is required).

After the turning process is completed, perform the same operation as in the above-mentioned start preparation stage, and place the processed workpiece a at the clamp part A11ll.
Pull it out and remove it.

<Effects of the Invention> According to the outer diameter turning device of the present invention, it is possible to achieve high precision outer circumferential turning of a small diameter elongated member with a special shape such as a ribbed heat exchanger tube, The airtight performance at the plate joints and the resulting reliability are improved.

[Brief explanation of drawings]

FIG. 11 is a side view of the entire embodiment of the present invention. Fig. 2 is a longitudinal sectional view of the clamp part, Fig. 3 is a longitudinal sectional view of the turning head, Fig. 4 is a longitudinal sectional view of the feeding mechanism, and Fig. 5 is a sectional view of the workpiece after turning. Figure 6 is the ■
−■ It is a sectional view taken along the arrow. Also, in the symbols in Fig. 1, A is the workpiece clamping part, B is the turning head part, C is the undercutting mechanism part, a is the workpiece, l is the bed, 2 is the slide guide, 4 is the collet chuck, and 9a and 9b are the fluids. A pressure piston, 10 is a sliding table, 11 is for support, and 12 is a turning head. 14 is a main shaft, 16 is a bearing cylinder, 18 is a drive shaft, 20 is a drive motor, 20a is a rotating shaft, 22 is a cutting tool holder, 24 is a cutting tool, 25 is a stop shaft, 26 is a coil spring, 28 is a sliding tube, 30 .54 is a female thread cylinder, 34 is a cutting drive motor h36e3a is a workpiece support, 37a, 42
a is the collet part, 38.43 is the guide bush %, and 50 is the feed support base. 52 is a drive motor, and 60 is a male threaded cylinder.

Claims (1)

[Claims] A bed having a slide guide, a workpiece fixing chuck provided at one end of the bed and holding a long workpiece parallel to the slide guide and immovably, a sliding table that moves on the bed; a cylindrical main shaft that is attached to the sliding table and through which the workpiece passes through the center; and a cylindrical main shaft that is rotationally driven by a turning drive motor; a cutting tool holder that is supported to fix a cutting tool and is movable in the radial direction; a cutting control mechanism capable of moving the cutting tool holder forward and backward during rotation of the main shaft; A peripheral turning device equipped with a pair of workpiece supports that slidably support the workpiece.