CN100574950C - Method for processing thread with numerical control lathe and its thread processing tool - Google Patents

Abstract

The invention relates to a method for processing threads with a numerically controlled lathe and a thread processing tool thereof. The method is: adopt a thread processing tool, and clamp it on the cutter head of the CNC lathe, before performing thread processing with a pitch of T, the sleeve and the tool body in the tool are closely attached to each other in the axial direction, During processing, the axial displacement of the cutter head is 88-98% T/turn. The thread processing tool includes a thread processing tool, a tool body and a sleeve, the tool body is sleeved on the outside of the sleeve, the two can move relatively axially, and the thread processing tool is clamped at the front end of the sleeve. Its advantages are: the thread processing of multiple thin and long workpieces can be completed continuously in one clamping, the entire processing process is automatically completed, the degree of automation is high, the processing quality is high and stable, the number of tool installations is greatly reduced, and the auxiliary time is saved to shorten the processing time. , Improve work efficiency, effectively reduce processing costs, and reduce operator labor intensity.

Description

Method for processing thread with numerical control lathe and its thread processing tool

technical field

The invention relates to a processing method of a numerically controlled lathe and a fixture thereof, in particular to a method for processing a thread with a numerically controlled lathe and a thread processing tool thereof.

Background technique

At present, when processing a threaded workpiece with a CNC lathe, a special thread turning tool is generally used and controlled by a program. During processing, the workpiece bears a large radial force. If the nominal diameter of the thread of the workpiece is small and the thread length is long, the radial force of the thread turning tool on the workpiece is easy to bend and deform the workpiece, so that the workpiece is scrapped. Therefore, the threaded workpiece processed by CNC lathe generally has a large nominal diameter and a short length.

Simultaneously, the existing numerical control car cannot use the thread turning tool to process the workpiece with a larger diameter shaft shoulder at the end of the thread. Because, when the thread processing is finished, the turning tool is easy to damage the end face of the shaft shoulder, so that the workpiece is scrapped.

Therefore, when the above-mentioned situation occurs when the CNC lathe processes the thread, it is often used to place the thread processing mechanism of the ordinary lathe on the tailstock of the CNC lathe, and the tailstock is hand-operated to process the thread. Or unload the workpiece, tap the thread by hand, or transfer to other machine tools for processing. This operation requires frequent start-up of the machine tool, frequent clamping of the workpiece, and alignment of the workpiece. The entire workpiece cannot be processed to the maximum extent in one clamping, and the processing efficiency is low. Hand-operated tailstock is a thread processing method for ordinary lathes. It relies on the friction between the outer wall of the clamping part of the thread processing mechanism and the inner hole wall of the tailstock sleeve to transmit power. The contact part between the two is easy to slip, so that the thread is scrapped. At the same time, if the manual force is uneven during the processing, it is easy to make the thread profile uneven, resulting in the scrapping of the workpiece.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and provide a kind of thread that can be continuously processed with a numerically controlled lathe with a small nominal diameter and a long length or a thread that is close to a large shaft shoulder, so as to reduce the processing auxiliary time and improve the processing efficiency. An efficient method for processing threads with a numerically controlled lathe and a thread processing tool thereof, which are realized through the following technical solutions:

The method of machining threads with a CNC lathe is to use a thread processing tool and clamp it on the cutter head of the CNC lathe. During processing, the axial displacement of the cutter head is 88-98% T/circle.

The thread processing tool for processing threads according to the above method includes a thread processing tool, a tool body and a sleeve. The tool body is sleeved on the outside of the sleeve, and the two can move relatively axially. The thread processing tool is clamped at the front end of the sleeve.

The sleeve is provided with an axial guide groove, and a screw is screwed on the tool body in the radial direction and extends through the tool body into the guide groove, so that the tool body moves axially relative to the sleeve along the guide groove.

The thread processing tool is a die or a tap, the die is fixed on the front end of the sleeve by a set screw, and the tap is fixed on the front end of the sleeve by a set screw and through a tap jacket.

The invention uses a thread processing tool to enable the numerical control lathe to continuously complete the thread processing of multiple slender workpieces or workpieces with larger shoulders at the end of the thread in one clamping, and the entire processing process is automatically completed. The processing range of the CNC lathe is expanded, and the thread processing quality of the CNC lathe processing slender workpieces or workpieces with larger shoulders is improved. The tool changing time is reduced, the work efficiency is improved, the labor intensity of the operator is reduced, and the processing cost is effectively reduced. Through the control program, the entire tool body and cutter head can be moved axially at a speed slightly less than twice the pitch T. In this way, when the die or tap is machining threads, it can slowly cut into the workpiece to prevent the tool from slipping when processing the first few pitches after touching the workpiece. , so that the tool is damaged by extrusion, and the utilization rate of the tool is improved. When the threading tool cuts into the workpiece, the tool drives the sleeve to move at a speed of one pitch, while the tool body and the cutter head move in the same direction at a speed less than one pitch, and the two move differentially, and the tool body does not move during processing. As for the extrusion of the sleeve, the thread profile is deformed.

In addition to playing a guiding role, the guide groove on the sleeve in the thread processing tool of the present invention is also convenient for chip removal and coolant discharge, and better protects the cutter head.

Description of drawings

Fig. 1 is a schematic structural view of a threading tool according to an embodiment of the present invention.

Fig. 2 is one of the process of processing external thread of the present invention.

Fig. 3 is the second process of processing the external thread of the present invention.

In the figure, 1 set screw, 2 dies, 3 guide screws, 4 tool body, 5 sleeve, 6 guide groove, 7 workpiece, 8 cutter head, 9 tap jacket, 10 taps.

Detailed ways

Referring to FIG. 1 , the threading tool of this embodiment is mainly composed of a die 2 , a tool body 4 and a sleeve 5 . The tool body 4 is sleeved on the outside of the sleeve 5 , and the two can move axially relative to each other. The die 2 is clamped on the front end of the sleeve 5 through the set screw 1 . A guide groove 6 is arranged on the peripheral side of the sleeve 5 along its axial direction, and a guide screw 3 is screwed along the radial direction on the peripheral side of the tool body, and the screw extends into the guide groove 6 on the sleeve to make the tool body 4 The screw 3 screwed on it moves axially along the guide groove 6 relative to the sleeve and cannot be rotated relative to it.

Continuously process thin and long threaded parts with a CNC lathe and the threading tool shown in Figure 1:

Referring to Fig. 2, clamp the thread processing tool shown in Fig. 1 on the CNC lathe cutter head 8 and press it on the cutter head 8 by the cutter head pressing screw. When clamping, pay attention to the guide groove on the sleeve 5 toward the down for chip and coolant drainage. After tool setting, the tool body is naturally close to the sleeve. Through the design of the lathe program, the axial feed L of the cutter head 8 is slightly smaller than the pitch T of the thread on the machined part, generally L=88-98%T.

Referring to Fig. 3, after thread processing starts, the cutterhead moves axially. When the threading tool is in contact with the end surface of the workpiece, since the cutting edge of the die has a taper, the cutting end of the workpiece thread also has a taper formed by the chamfer. incomplete threaded portion on the If the cutterhead drives the threading tool to feed at a cutting speed of twice the pitch, the following situation often occurs: the die 2 on the threading tool advances along the threading direction. At the beginning, the die cannot cut in due to insufficient cutting force On the workpiece, the die is easily damaged by a large extrusion force at this time. Therefore, in the operation program design, the axial feed L of the cutter head 8 is slightly smaller than the pitch T of the thread on the machined part. In this way, the die can cut into the workpiece at a slower speed, and the die is not easily subjected to a large extrusion force, thereby effectively protecting the die.

When the die 2 cuts into the workpiece 7, the die and the sleeve move at a speed of 1 pitch T/turn, and the tool body 5 clamped on the cutter head 8 is slightly smaller than 88-98% of the pitch T designed in the operating program. With the speed movement of the T/ring, the moving speed of the sleeve and the die is faster than the speed of the tool body and the cutterhead. Since the sleeve is restricted by the pin, it cannot produce circumferential rotation and can only move faster than the axial movement of the cutterhead. The tool There is differential movement between the body 4 and the sleeve 5, the sleeve close to the tool body 4 is gradually separated from the tool body, the guide groove on the sleeve is continuously exposed, and the coolant and fine chips fall from the guide groove.

When the thread processing length reaches the programmed control size, the control program will reverse the workpiece, and the tool will retreat at the speed of one times the pitch. In addition, it can be seen from the figure that even if the workpiece has a large shoulder and the end of the thread is very close to the shoulder, the die will not damage the shoulder.

Dies and sleeves retreat at a speed of one pitch T/turn. Cutter head and tool body 4 can be faster than the retreat speed of die and sleeve, also can be identical with the retreat speed of die and sleeve.

The method of the present invention is also suitable for processing internal threads. First, the tap 10 is fixedly clamped on the tap jacket 9 by the set screw 1 , and then the tap jacket 9 is fixed on the front end of the sleeve 5 by the set screw 1 . The processing process is similar to the above-mentioned process and will not be repeated here.

Claims (1)

1. use the method for lathe in machining screw thread, it is characterized in that adopting a screwing tool, and with its clamping on the cutterhead of numerically controlled lathe, before carrying out the screw thread processing that pitch is T, sleeve in this instrument and body of tool axially are being close to mutually, add man-hour, described cutterhead axial displacement is 88～98%T/ circle;

Described screwing tool comprises threading tool, body of tool and sleeve, and body of tool is socketed in the sleeve outside, and both can move to axial, and the threading tool clamping is at the front end of sleeve; Described sleeve is provided with gathering sill vertically, and a screw radially is screwed on the body of tool and passes body of tool and extends in this gathering sill, and the relative sleeve of body of tool is moved axially along gathering sill; Described threading tool is screw die or screw tap, and screw die is fixed on the front end of sleeve by holding screw, and screw tap is by holding screw and be fixed on the front end of sleeve by tap chuck.

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