JPH03161B2 - - Google Patents

Description

[Detailed Description of the Invention] (Objective of the Invention) The present invention uses a device with a simple structure that uses a profiling method that utilizes cutting resistance to offset the centrifugal force and gravity, as well as the elastic force of a spring. The present invention relates to a method and apparatus for sharply chamfering the end face of a steel pipe with the aim of smoothly and accurately chamfering the end face of a steel pipe.

(Prior art) As shown in Figs. 1 to 3, the conventional Kaisaki chamfering device for the end face of a steel pipe moves to the front surface A of the face plate C of the chamfering machine L with respect to the center line O-O of the rotation axis S. Groove M
A moving block B is provided which fits into the moving groove M. A sliding groove A compression spring F was interposed so that the elastic force could be freely adjusted, and a chamfering tool T and a copying roller R were fixed to this sliding block D facing forward (to the left in Figures 2 and 3). However, this would complicate the structure and the copying force N of the copying roller R is only adjusted by the elastic force of the compression spring F. Therefore, the centrifugal force due to the rotation of the face plate C is expressed as E, and the weight of the moving part is If Z is the cutting force caused by W and the cutting tool T, N>W+E+Z must be satisfied, and it is extremely difficult to stabilize the tool in the vertical position due to the centrifugal force E, cutting force component Z, and weight W, which will cause chatter. There is no damping effect when vibration occurs, making it difficult to perform stable cutting.In the case of thin-walled pipes, it is difficult to adjust the elastic force of the compression spring F because the excessive tracing force N deforms the pipe. necessary and very difficult to adjust. When the copying roller R moves forward and backward with respect to the pipe P, the copying force N damages the pipe end face and the roller R, and the sliding becomes unsmooth due to dust entering the sliding surface X, etc. There are problems such as abrasion of the sliding surface, and therefore, highly accurate contour chamfering work and highly efficient cutting work cannot be expected.

(Structure of the Invention) In view of the above-mentioned problems, the present invention provides a copying roller attached to one end of a rotating arm rotatably pivoted at the center of gravity on a rotating shaft installed in the front surface of a face plate of a chamfering machine. A chamfering tool is provided with a mounting part, and an adjustment spring is hung between the other end and a face plate.The present invention will be explained with reference to the drawings of the embodiments.

Embodiment In FIG. 4, a chamfering machine 1 has a machine casing 4 mounted on a machine stand 3 on a machine floor 2 so as to be slidable in the axis 0-0 direction.
A drive motor 5 is mounted on the machine casing 4, and a driven pulley 8 is mounted on the motor pulley 6 and one end of a rotating shaft 7 that is rotatably supported horizontally on the machine casing 4.
A rod 11 of a hydraulic cylinder 10 is attached to the machine floor 2 in the axial direction with a V-belt 9 suspended between the rod 11 and
A front end of the rotary shaft 7 is connected to the machine casing 4 so that the machine casing 4 can move forward and backward in the axial direction, and a face plate 12 is attached to the end opposite to the driven pulley 8 of the rotating shaft 7 supported by the machine casing 4. A copy chamfering device 13, which will be described in detail later, is attached to this face plate 12, and a pipe mount 14 is disposed on the machine floor 2 opposite to this face plate 12 so that the pipe P to be processed can be fixed and released.

The copying chamfering device 13 will be described in more detail.
5 to 7, the rotating shafts 15, 15 are fixed at symmetrical positions with respect to the center 0 on the front surface of the face plate 12, respectively, by screwing and fixing the rotating shafts 15, 15 on the base plate 16 with the setscrews 17. The center of a cylinder 19 into which a disk 18 fixed at the tip is rotatably fitted is provided with a rectangular-shaped rotating arm 20 whose center of gravity is approximately at the center of gravity, and a balance weight is attached to the rear end of each rotating arm 20. 20', a chamfering tool mount 21 to which a chamfering tool T can be freely attached and detached is fixed to one side of this rotating arm 20, a shaft 22 is protruded from the front surface of this chamfering tool mount 21, and a shaft 22 is attached to this shaft 22. A copying roller 24 having a copying surface 23 on its outer circumferential surface is freely rotatably mounted via ball bearings 25, 25, and a tension spring 27 has one end hooked to a pin 26 implanted on the other side of the rotating arm 20. The other end is hooked to a pin 30 protruding from an adjustment piece 29 screwed into an adjustment screw 28 provided on the holding board 16.

In FIG. 4, reference numeral 31 indicates a chuck of the pipe P to be processed provided on the mounting base 14.

In this example, the outer surface of the pipe to be machined is copied and the outer surface is contoured, but depending on the contact angle of the chamfering tool and the way in which the copying roller contacts the outer or inner surface of the pipe to be machined, end face processing, It is possible to perform internal contouring by copying the outside surface, contouring by contouring the outer surface by copying the inner surface, and contouring by contouring the inner surface by copying the inner surface.

(Function of the Invention) To explain the function of the present invention with reference to the drawings of the embodiment, in Fig. 4, the mounting base 14 installed in the front (on the right side in Fig. 4) on the machine floor 2 of the chamfering machine 1 is shown. Fix the pipe P to be processed to the chuck 31 with the end surface protruding toward the face plate 12, and operate the drive motor 5 to
When the rotary shaft 7 is rotated via the belt 9, the face plate 12 attached to the tip of the rotary shaft 7 starts rotating, and the oil cylinder 10 continues until it approaches the cutting position G of the profiling chamfering device 13 attached to the face plate 12. When the machine casing 4 is moved forward by actuating, as shown in FIGS. 5 to 7, the copying surface 23 of the pair of copying rollers 24 provided on one side of the F-shaped rotating arm 20 is moved forward. The tension spring 27 is adjusted by the adjustment screw 28 attached to the restraining board 16 fixed to the face plate 12 so that it comes into light elastic contact with the outer surface of the pipe P to be processed, so that the rotation of the face plate 12 is controlled. At the same time, the copying roller 24 rolls while lightly contacting the outer surface of the pipe P to be processed and accurately follows the pipe P to be processed even if the pipe P is not a perfect circle.

Next, when the hydraulic cylinder 10 is operated and the chamfering tool T is gently pressed against the end surface of the pipe P to be processed, the outer surface contour K (FIG. 6) is cut.

At this time, since the rotating arm 20 is rotatably attached to the rotating shaft 15, Ft: Main cutting resistance due to the cutting tool (in the pipe circumferential direction, opposite to the rotation direction, proportional to the pipe wall thickness) Fr: Ft Radial component force (Fr<1/3Ft) R ₁ : Distance between the center O ₁ of the rotating shaft 15 and the point of application H of Pt R ₂ : Distance between the center O ₂ of the shaft 22 and the same O ₁ Then, the radial pressing force F _F (copying force) of the copying roller during cutting is F _F = FtR ₁ −FrR ₂ /R ₂ , and the cutting force during cutting is always proportional to the pipe wall thickness.
A tracing force F _F proportional to Ft is generated, and its magnitude is:
It can be freely set by changing the ratio of distance R ₁ and distance R ₂ .

Also, since the copying force F _F is generated by the cutting force Ft,
The copying force of the copying roller 24 becomes 0 when the copying roller 24 enters and exits the pipe P to be processed.

In addition, since the center of the rotating shaft 15 of the rotating arm 20 is made approximately coincident with the center of gravity of the rotating arm 20 including the weight of the copying roller 24 and the chamfering tool T, O ₁
If the weight of the rotating arm 20 on the O ₂ side is W ₁ and the weight on the opposite side is W ₂ , then W ₁ ≒ W ₂ , and the centrifugal force P ₁ due to W ₁ and the centrifugal force P ₂ due to W ₂ Then, P ₁ ≒ P ₂ , and even if the face plate 12 rotates, the effects of centrifugal force and weight are canceled out, so it has almost no effect on the copying force, and furthermore, this copying chamfering device 13 Since the pieces of the same shape are mounted at symmetrical positions with respect to the center O on the face plate 12, no vibration occurs due to the difference in centrifugal force due to unbalanced weight. Also, the copying force F _F during cutting is the cutting force
Since Ft always acts to press the copying roller 24 against the surface of the pipe P to be processed, chattering vibration of the chamfered pipe T can be prevented.

Although the case of the outer surface copying and outer surface contouring processing of the embodiment has been described above, the operation is the same for the other four types of processing described above.

(Effects of the Invention) The present invention provides a constant profiling force to the profiling roller by the cutting force of the profiling roller and the cutting tool of the chamfering tool on one side of the F-shaped rotary arm that is freely rotatable about the center of gravity on the face plate. The tension spring, with one end hooked to the other side, is locked to the adjustment screw attached to the restraining board fixed on the face plate, and then the tension spring is placed on the surface of the pipe to be machined. Since the contact is made with appropriate elastic force and the cutting force of the cutting tool is used to generate the profiling force, even if the face plate rotates, the rotating arm cancels centrifugal force and gravity around the rotating axis. Therefore, even if the pipe to be machined is not a perfect circle, it can be traced with a nearly constant tracing force.In other words, since the cutting force of the chamfering tool is used as the tracing force, the cutting force is proportional to the wall thickness of the pipe to be machined. Since there is only a profiling force proportional to , it is extremely effective to be able to perform extremely precise round chamfering with a simple device without deforming even thin-walled pipes.

Further, since the copying chamfering device does not require a sliding surface, there is no need to adjust the gap, and the advantage that the equipment is inexpensive and the work is easy is also unique to the present invention.

Furthermore, since the copying roller only contacts the pipe surface with only a weak spring force to maintain its position when not cutting, the copying roller does not damage the end surface of the pipe when moving in and out of the pipe. do not have.

[Brief explanation of the drawing]

Figure 1 is a schematic front explanatory diagram of the main parts of the prior art;
Fig. 2 is a schematic plan view of the same, Fig. 3 is a schematic side view of the same, Fig. 4 is a partial cross-sectional front view of the chamfering machine embodying the present invention, and Fig. 5 is a main view of the same. FIG. 6 is a schematic partially sectional plan view of the same, and FIG. 7 is a partially sectional side view thereof. Explanation of symbols of main parts, 1... Chamfering machine, 4...
Machine casing, 10...hydraulic cylinder, 12...face plate,
13... Copy chamfering device, 14... Mounting stand, 15
... Rotation axis, 16 ... Holding board, 18 ... Disc,
19... Circular fossa, 20... Rotating arm, 21... Chamfering tool mounting base, 20'... Balance weight, 2
3... Copying surface, 24... Copying roller, 27...
Tension spring, 28... Adjustment screw, P... Pipe to be processed, T... Chamfering tool.

Claims (1)

[Scope of Claims] 1. The outer circumferential surface of the steel pipe is moved by a copying roller freely rotatable on one side of a rotary arm that is rotatably mounted around a rotary shaft whose center of gravity is pivoted on the end face of a face plate. At the same time, when cutting a sharp chamfer on the end face of the steel pipe using a cutting tool attached to a cutting tool mount provided on the same side as the copying roller of this rotating arm, the rotating arm on the opposite side of the center of gravity The other end of the spring for holding the position of the rotating arm is hooked on a part of the face plate, and a balance weight is attached to the end of the rotating arm on the same side as the spring. A method for sharp chamfering the end face of a steel pipe, which is characterized by holding the position of a moving arm, pressing a copying roller against the pipe surface by the rotational moment of cutting resistance generated during cutting, and generating a pressing profiling force corresponding to the cutting force. 2. A rotating arm is rotatably attached to a rotating shaft installed on the end face of a face plate of a chamfering machine equipped with a machine casing that can freely move forward and backward in the direction of the rotational axis, and the rotating arm is rotatably mounted at approximately the center of gravity. A copying roller is freely rotatably attached to one side of the upper surface, and a mounting base for a chamfering tool is provided on the same side of the copying roller with respect to the rotation axis on the upper surface of the rotating arm, and a mounting base for a chamfering tool is provided on the same side of the rotation shaft on the upper surface of the rotating arm. The other end of a spring for holding the position of the rotating arm, one end of which is hooked on the side opposite to the base, is hooked to the face plate in a manner that allows the tension to be adjusted freely, and a balance weight is further provided on a part of the rotating arm. Kaisaki chamfering device for steel pipe end faces.