JPH06170603A - Guide bar pipe for automatic lathe - Google Patents

Abstract

PURPOSE: To perform machining of a bar having diameter in a wide range, to suppress floating of a rotating bar, to prevent the occurrence of inaccuracy of a product occasioned by floating, and to execute high-speed rotation of a bar through suppression of the generation of noise to a low value. CONSTITUTION: A guide bar pipe 1 has a center setting travel base 10. The travelbase 10 is distributed in two parallel planes, and a ball is provided to fix the travelbase 10 at the guide bar pipe 1 or at the rod 11 of a feed piston. This constitution operates a feed piston 2 to advance a rod material to a lathe and draw the piston 2 to the rear of a device through a vacuum. The presence of the travelbase 10 normally loaded on the rod 11 of the feed piston prevents the occurrence of a risk of a rod material in the guide bar pipe 1 and the feed rod 11 being buckled and floated. This constitution considerably increases the number of revolutions of a rod and eminently decreases the generation of noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is a guide rod tube for single and / or multi-spindle automatic lathes having a feed piston of a diameter equal to or less than the diameter of the rod material to be processed. A guide rod tube for feeding the rod toward a lathe.

[0002]

BACKGROUND OF THE INVENTION When machining a rod on a lathe, the rod is prone to buckling in the guide rod tube and / or in the headstock of the lathe. This buckling often occurs, especially for high speed rotating rods, due to the long rod and relatively small diameter. The risk of buckling is exacerbated when the rod is pushed towards the headstock of a lathe. Due to this buckling (FIG. 1), the rod 3 floats in the guide rod tube and in the headstock of the lathe. Floating of the rod causes balance errors and vibrations that are transmitted to the headstock of the lathe, causing inaccuracies in the machining of the rod, such as workpiece concentricity errors, elliptical distortion and surface quality defects. In FIG. 1, the rod 3 is the head 11 a of the feed piston 2.
2 shows the device free between the chuck and the chuck 5 of the lathe. This is the least preferred as it has the maximum deformable length. FIG. 2 shows the effect of a centering ring placed between the outlet of the guide tube 1 and the inlet of the headstock 4. Such a centering ring is the subject of US Pat. No. 4,507,992 by the same inventor as the present invention. This centering ring 7 offers the improvement that the rod, which is held by the chuck of the lathe and is centered and supported by the feed piston at its rear end, is prevented from floating in the position of the ring 7. . However, in this case the rod is still floating between the feed piston 2 and the ring 7 and between the ring 7 and the chuck of the lathe.

The ideal solution is to use a lathe with a sleeve that reduces the headstock according to the material diameter and a hydrodynamic guide rod tube with an inner diameter that is optimally dimensioned for the diameter of the rod to be guided. It would guide the rod over its entire length in the headstock. However, this solution requires a guide tube corresponding to each diameter and shape of the rod to be processed, and there is a cost and starting time that are unacceptable in practice, and it is difficult to apply in practice. is there.

FIG. 3 suggests another improvement by placing the headstock reduction sleeve 8 between the centering ring 7 and the headstock 4 of the lathe. This method is
It is used in a device which is the subject of European Patent Application No. 88810416.3. This principle requires that the diameter of the feed piston be equal to the diameter of the rod to be machined, but smaller, in order to allow the feed piston to pass through the centering ring and into the headstock reduction sleeve of the lathe. It has the drawback of being. In this case, the rod 3 and the feed piston will still float in the guide tube 1 having a diameter of the rod, a diameter larger than the diameter of the feed piston.

A telescoping guide rod device is also known from DE-OS 25 33 502, which has an outer tube slidable in the fixed tube of the apparatus, in which the feed piston rod is It is slidable. The feed piston rod has, at its front edge, a head portion that supports the rear portion of the rod to be processed, and feeds the rod toward the headstock of a lathe. The diameter of the head is smaller than the diameter of the spindle, the diameter of the centering ring located at the entrance of the headstock, so that the head can penetrate into the headstock. The nested principle can reduce the length of the device. However, the device of the above document is relatively complex and expensive in concept. The advancement of the processed bar is pneumatically controlled without the provision of hydrodynamic bearings to support the bar, thus limiting the rotational speed of the bar.

[0006]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a guide rod tube capable of accepting various rod diameters and / or rod shapes to be machined guided therein. Equipped with a feed piston with a head outer diameter equal to or smaller than the diameter of the smallest rod, it feeds the feed piston through the ring and into the headstock reduction sleeve, and
When the feed piston is engaged in the guide rod tube, it is maintained without floating in the center of the guide rod tube, ensuring that it supports and centers the rod, simple and inexpensive To discover the device.

The object of the present invention is to equip the feed piston with a centering carriage, which secures the carriage to the front of the feed piston while the head of the feed piston is engaged in the guide rod tube. And a device having means for fixing the carriage to the front of the guide rod tube when the head of the feed piston enters the headstock of the lathe. The presence of a running ring or centering platform firmly holds the rear part of the rod to be processed, and also the floating of the feed piston in the guide rod tube and the rear part of the rod in contact with the feed piston. It is possible to avoid both.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. 4 and 5 respectively show a longitudinal section and a cross section of the centering carriage, and also show details of mounting the ball 13 in its housing. The centering platform 10 has a sleeve 12 in which a ball 13 is housed in a radial hole in the sleeve. The ball is the hole 14 of the sleeve.
It is free to move in the radial direction and in the axial direction of the hole. In the example shown, the sphere 13 is divided into two groups of three parallel planes. In each plane, the three spheres are spaced at an angle of 120 °. This arrangement is preferred, but not limiting. FIG. 6 shows how the sphere 13 is supported in the housing with a gap in the axial direction of the hole 14.

The centering platform 10 is intended to be mounted on the rod of the feed piston 2 or on the head 11a of the feed piston. FIG. 7 shows a state of the centering platform in which the centering platform is fixed to the rod 11 of the feed piston 2 and at the same time to the head 11a of the feed piston. FIG. 11 shows the rod 11 of the feed piston 2 which feeds the rod 3 towards the lathe. On the other hand (FIG. 7), the centering carriage 10 is shown fixed to the rod 11 of the feed piston 2 by means of a ball 13 engaged in a groove 15 in the surface of the rod 11 of the feed piston 2. Furthermore, FIG.
Shows a groove 16 on the inner surface of the front of the guide rod tube. The groove 16 enables the centering carriage 10 to be released from the rod 11 of the feed piston 2.

FIG. 8 (see also FIG. 12) shows one state in which the centering carriage 10 is in contact with the stop 17 at the edge of the guide rod tube 1. The advance of the feed piston moves the ball 13 from the groove 15 of the rod 11 of the feed piston 2 to the guide rod tube 1
To the groove 16. Therefore, the centering platform 10
Is fixed at the front of the guide rod tube 1, the rod of the feed piston continues its path and enters the headstock of the lathe, allowing the material to advance until the rod is fully machined I have to. FIG. 10 (see also FIG. 13) shows a sphere 1 in which the carriage 10 is attached to the guide rod tube 1 and engages in the groove 16 of said tube.
It is fixed there by 3.

When the rod is completely machined, the feed piston 2
Is retracted to the rear of the device. When the position of FIG. 9 is reached, the head 11a of the rod of the feed piston, which has an outer diameter larger than the inner diameter of the centering carriage 10, supports the carriage and the carriage feeds from the groove 16 of the guide rod tube. Vessel rod 11
It is released from the guide rod tube 1 by the ball 13 moving into the groove 15 of the. The above is the head 1 of the feed piston 2.
1a shows that it is always perfectly centered with the carriage 10, even when the rod head diameter of the feed piston is considerably smaller than that of the guide rod tube. Therefore, the rear part of the rod 3 is completely centered by the head part 11 a of the feed piston 2.

On the one hand, this uses a feed piston of small diameter such that it can enter the headstock of a lathe,
Tailoring the diameter of the headstock to match the material with the headstock reduction sleeve allows to increase the range of rod diameters received in the guide rod tube. On the other hand, the rear part of the rod is completely centered, the rod is guided under the hydrodynamic bearing over the entire length of the guide rod tube, and a centering ring is provided on the front face of the guide rod tube. And the fact that the rod is guided in the headstock of the lathe with a reduction sleeve determined according to the diameter of the rod, leading to balancing errors, vibrations and the associated drawbacks. Allows you to avoid floating floating rods.
Finally, it should be mentioned that the feed piston is actually displaced by hydraulic pressure, the oil being between the rod of the feed piston and the guide tube, and between the guide tube and the bar to be machined. Forming a hydrodynamic bearing which carries the feed rod and the rod to be processed there.

[Brief description of drawings]

FIG. 1 shows a prior art device.

FIG. 2 shows a prior art device.

FIG. 3 shows a prior art device.

FIG. 4 is a longitudinal cross-sectional view of the centering traveling platform of the present invention.

FIG. 5 is a cross-sectional view of the centering traveling platform of the present invention.

FIG. 6 is a diagram showing the ball mounting of the centering traveling platform of the present invention.

FIG. 7 shows one state of the centering platform.

FIG. 8 shows one state of the centering carriage.

FIG. 9 shows one state of the centering platform.

FIG. 10 shows one state of the centering platform.

11 shows the position of the feed piston corresponding to the state of FIG.

12 shows the position of the feed piston corresponding to the state of FIG.

13 shows the position of the feed piston corresponding to the state of FIG.

[Explanation of symbols]

 1 Guide tube 2 Feed piston 3 Rod to be machined 4 Headstock 5 Lathe chuck 7 Centering ring 10 Centering platform 12 Sleeve 13 Ball 11 Feed piston rod 11a Feed piston rod head 15, 16 Groove

Claims (7)

[Claims] 1. A feed rod tube having a feed piston with a diameter equal to or smaller than the diameter of the rod material for feeding the rod material to be processed towards a lathe, said feed piston being centered. Has a platform, the centering platform is
While the head of the feed piston is engaged in the guide rod tube, the traveling platform is fixed to the front part of the feed piston, and when the head of the feed piston enters the headstock of the lathe. , A guide rod tube having means for fixing the traveling platform to the front part of the guide rod tube. 2. The guide rod tube according to claim 1, wherein said means comprises a sleeve having a radial bore into which an axially movable ball of the bore engages, The sphere partially engages in a groove formed on the outer surface of the feed piston to secure the centering carriage to the feed piston, or the sphere is formed in a groove formed on the inner surface of the guide rod tube. A guide rod tube adapted to partially engage with and to secure the centering carriage to the guide rod tube. 3. The guide rod tube according to claim 2, wherein the spheres are distributed in the sleeve along two parallel planes perpendicular to the axis of the sleeve, each plane being a sphere in each plane. A guide rod tube having a set of one or more spheres regularly spaced from each other by an angle according to the number of. 4. A guide rod tube according to claim 3, wherein each of said surfaces has three spheres angularly spaced at 120 °. 5. A guide rod tube as claimed in claim 1, which holds the centering carriage when the head of the feed piston enters the headstock for feeding the remaining rod material towards the lathe. Thus, a guide rod tube in which a stop is provided at the front end of the guide rod tube. 6. The guide rod tube according to claim 2, wherein the feed piston is pulled out to the rear of the guide rod tube by vacuum until the head of the feed piston pushes the centering platform. , The centering carriage is fixed to the guide rod tube, and the pushing pressure causes the sphere to move from the groove on the guide rod tube to the groove on the feed piston to move the centering carriage from the guide rod tube. Guide rod tube designed to be released and fixed to the feed piston. 7. A guide rod tube according to claim 1, wherein the advance of the feed piston towards the headstock of the lathe is carried out by hydraulic means, on the one hand between the rod of the feed piston and the rod material. And, on the other hand, a guide rod tube provided with a fluid bearing between the rod material and the guide rod tube.