NL2027877B1

NL2027877B1 - Tool device and method for rough-machining pulley groove

Info

Publication number: NL2027877B1
Application number: NL2027877A
Authority: NL
Inventors: Ji Heju; Li Changhe; Hou Yali; Zhang Yanbin; Yang Min; Yang Yuying; Li Runze
Original assignee: Univ Qingdao Technology
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2022-10-12

Abstract

The present invention discloses a tool device and a method for rough-machining a pulley groove, which solve the problem of low pulley machining efficiency in the prior art, and has the beneficial effects of high machining efficiency and reduced wear on a tool, and the solution thereof is as follows: a tool device for rough-machining a pulley groove, including a tool bar, the tool bar being provided with a groove, a movable tool body, disposed in the groove of the tool bar, and linked with the tool bar by a lead screw shaft, the lead screw shaft cooperating with the movable tool body to realize a self-locking spiral lifting mechanism, and at least two groove cutters, one of which is mounted at an end of the movable tool body, and the other is mounted at an end of the tool bar, where a distance between the groove cutters is adjusted by rotating the lead screw shaft.

Description

-1- TOOL DEVICE AND METHOD FOR ROUGH-MACHINING PULLEY

GROOVE

TECHNICAL FIELD The present invention relates to the field of machining, and in particular, to a tool device and a method for rough-machining a pulley groove.

BACKGROUND Pulleys are disk-type hub parts. They are generally large in size, and are manufactured IO mainly by casting and forging. In general, casting is used in the design of a large size. The material is usually cast iron (which has good casting properties), and cast steel (which has poor casting properties) is rarely used. In general, a small size can be formed by forging with a steel material. As a main pillar industry of drive systems, the pulley industry in China has developed rapidly in recent years. The gap between domestic pulley manufacturers and foreign advanced technology has further narrowed. At present, pulleys produced in China have been able to meet the needs of domestic and foreign markets. However, China's pulley industry still has a series of problems such as many production enterprises, small scale, low level of export products, concentrated export market and fierce price competition. In addition, the machining and manufacturing technology of pulleys is also rapidly changing, due to the requirements of drive systems for parts weight and the increase in the price of raw material castings of pulleys. China's pulley industry has a large market share in the domestic market, but the ability of independent innovation is still weak, and the core technology is limited. The product and industrial structure are not reasonable; the problems of market structure, fierce competition and so on are still prominent. The gap between China and foreign countries in the manufacture of mainframes is shrinking. However, the production of some components still has many problems caused by long-term dependence on imports. The phenomenon of "surplus in the middle and low end and serious shortage in the high end" is obvious. In general, a large size pulley is designed to be cast, while a small size pulley is designed to be forged. Turning is one of the most common machining methods. As numerical control lathes have the characteristics of high machining precision, linear interpolation and circular

2- interpolation, and automatic shifting during machining, their process range is much wider than that of ordinary machine tools. All parts that can be mounted on a lathe fixture can be machined on a lathe. At present, the pulley machining process of factories and enterprises in China is: rough-tum a contour end face - finish-turn the contour end face - broach a keyway - rough-turn a pulley groove - fine-turn the pulley groove. Currently, the machining method of the pulley groove is: roll with a gang tool, and then fine-turn the contour. The machining time is long and the efficiency is low. If a workpiece is clamped too tightly during this process, the workpiece is easily deformed during turning; if the clamping is light, the workpiece is easy to be dropped.

IO Pulleys are in high demand in the market, and have high requirements on machining quality. For example, the surface is required to have not impurities, but uniform structure, low roughness, good straightness, etc. When cast iron pulleys are machined, the wear of a tool is fast, the cutting is slow during machining, and the shape accuracy is difficult to ensure. Therefore, the production cost is high, the production efficiency is low, and the quality of production and machining is poor, etc. Numerical control machining technology is the development trend of machining in the next few decades. It is an important and necessary technical support for the construction of modern manufacturing industry, and its application will become more and more extensive. Generally, there are mainly four methods for machining a pulley groove by using a numerical control lathe. The first method is to use a grooving turning tool and a forming turning tool to cooperate with each other to machine a workpiece by a program control method, like a pulley groove machining process by an ordinary lathe: first, the grooving turning tool machines a straight groove; and then, the forming turning tool trims a pulley groove.

The second method is to use a grooving turning tool and left and right hand tools to cooperate with each other to machine the parts by a program control method: first, the grooving turning tool machines a straight groove; and then, the left hand tool machines a left side, and the right hand tool machines a right side, thereby realizing the machining of a V-type pulley groove. The third method 1s to use a one-time forming turning tool to directly machine a pulley groove. The fourth method is to use only one grooving turning tool to machine the parts by a program control method: first, a straight groove 1s machined by turning; then, a left nose of the grooving turning tool machines a left side of a pulley groove, and a right nose of the grooving turning tool

-3- machines a right side of the pulley groove; and finally, fine-machining is performed, and the turning of a V-type pulley groove is completed step by step. The first method has the advantages that the process is mature, easy to implement, and the programming is simple, but the disadvantages lie in that the scrap rate is high, and itis necessary to sharpen the forming turning tool, so that the cost is high in small-lot production of single pieces. The second method has the advantages that the process is mature, the rigidity of the turning tool is good, and the machining precision is high, but the disadvantages lie in that the tool setting operation is complicated, and as the size of the left and right hand tools is large, it is not suitable for the machining of a small size IO pulley groove. The third method has the advantages of high machining efficiency and one-time forming, but the disadvantages lie in that the cost is relatively high and the tool wear is severe. The fourth method has the advantages that the tool is simple, the tool setting operation is simple, the program drawing is simple, easy to implement, the machining precision is good, and the method is suitable for small lot or mass machining, but the disadvantages lie in that the rigidity of the turning tool is poor, and the machining parameters need to be carefully selected. As the fourth method has the characteristics of simple selection of the machining tool, easy implementation, high machining precision, easy programming and so on, the fourth method is currently selected in China, that is, a common grooving cutter is used to machine with a numerical control lathe, to achieve the machining of a pulley groove. However, it is found that the above machining methods still have shortcomings. The machining efficiency is relatively low, and although there are multi- tooth forming turning tools for one-time forming, the tool wear is large, and after the wear, the turning tool needs to be sharpened, resulting in high cost and single applicability. Therefore, except for some parts with special requirements, such tools are generally not used.

SUMMARY In order to overcome the deficiencies of the prior art, the present invention provides a tool device for rough-machining a pulley groove, which can effectively adjust a spacing between groove cutters, and has strong adaptability, and a wider application range.

4- The present invention further provides a method for rough-machining a pulley groove, which can improve the machining efficiency of a pulley groove.

A tool device for rough-machining a pulley groove includes: a tool bar, the tool bar being provided with a groove;

amovable tool body, disposed in the groove of the tool bar, and linked with the tool bar by a lead screw shaft, the lead screw shaft cooperating with the movable tool body to realize a self-locking spiral lifting mechanism; and at least two groove cutters, one of which is mounted at an end of the movable tool body, and the other is mounted at an end of the tool bar, where a distance between the

IO groove cutters is adjusted by rotating the lead screw shaft.

In the above tool device, the lead screw shaft links the movable tool body and the tool bar; the movable tool body has a movable space 1n the groove of the tool bar, and by rotating the lead screw shaft, the movable tool body can drive a corresponding groove cutter to move, thereby making it easy to adjust the height of the movable tool body relative to the cutter bar.

Further, the tool device further includes a locking member connecting the tool bar to the movable tool body.

Further, the locking member includes a first set screw and a cone point positioning screw mounted on the same longitudinal face of the tool bar, and the first set screw is disposed on one side of the lead screw shaft; the locking member further includes a second set screw disposed on the other side of the lead screw shaft; after the position of a groove cutter is determined, the movable tool body is connected by the cone point positioning screw for positioning, and then the movable tool body is connected to the tool bar by the first set screw; the first set screw is above the slotted cone point positioning screw.

Further, the first set screw is a flat point set screw, and in order to uniformly lock the movable tool body and enhance the stability, a second set screw 1s specially disposed, and the second set screw is a tool body hexagon socket head cap screw.

Further, the tool device further includes at least one optical shaft longitudinally passing through the tool bar and the movable tool body, the optical shaft is used for guiding the movable tool body in the longitudinal direction of the tool bar, and the movable tool body 1s completely positioned by the end face of the tool bar, the inner side wall of the tool bar and the slotted cone point positioning screw.

-5- Further, the optical shaft is disposed on both sides of the lead screw shaft.

Further, one end of the lead screw shaft protrudes from the tool bar, and a bearing is disposed between the lead screw shaft and the tool bar; an end of the lead screw shaft is provided with a nut to facilitate the rotation of the lead screw shaft, a bearing is disposed between the lead screw shaft and the tool bar, and the lead screw shaft and a bearing inner race as well as a bearing outer race and the tool bar are connected by interference fitting.

Further, an end of the tool bar is provided with a pressure plate for pressing the groove cutter, and the pressure plate is connected to the tool bar through a third lock screw, so that the setting of the third lock screw can make the pressure plate press the groove cutter . Further, the tool bar is provided with a scale line at the end with the groove cutter; the disposing of the scale line makes it easy to determine the position of the groove cutter, a center distance between points of the two groove cutters can be adjusted in the range of 10-25 mm, which is suitable for the machining of various types of pulley grooves.

The lead screw shaft bears a small force in a vertical direction; both ends of the lead screw shaft are connected with the bearing by interference fitting, and the position of the movable tool body can be manually adjusted.

To overcome the shortcomings of the prior art, the present invention further provides a method for rough-machining a pulley groove, using the above tool device for rough- machining a pulley groove.

Compared with the prior art, the present invention has the following beneficial effects. 1) The present invention can adjust a tool of two groove cutters based on different types of pulleys by the disposing of a movable tool body, thereby machining pulleys with different center distances between pulley grooves, and having stronger adaptability and a wider application range. 2) The tool of the present invention is for use on a groove cutter; the cost is greatly reduced, and the groove cutter can be quickly replaced without the need for on-site grinding, thereby preventing the production from being affected. 3) The present invention can theoretically improve the machining efficiency of a pulley groove process by 50%, which has a great benefit for the mass production of a pulley, can adapt to various production scales, improve the machining efficiency, and

-6- effectively reduce the wear of the tool. It is recommended to delete the latter half of the sentence, as the present invention does not reduce tool wear.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings of the specification which constitute a part of the present invention provide further understanding of the present invention. The schematic embodiments of the present invention and description thereof are intended to explain the present invention and are not intended to constitute an improper limitation of the present invention.

FIG. 1 is a cross-sectional view of a device according to an embodiment of the present invention; FIG. 2 is a front view of a device according to an embodiment of the present invention; FIG. 3 is a top view of a device according to an embodiment of the present invention; FIG. 4 is a side view of a device according to an embodiment of the present invention; FIG. 5 is a cross-sectional view of a tool bar according to an embodiment of the present invention; FIG. 6 is a front view of a tool bar according to an embodiment of the present invention; FIG. 7 is a side view of a tool bar according to an embodiment of the present invention; FIG. 8 is a front view of a movable tool body according to an embodiment of the present invention; and FIG. 9 is a top view of a movable tool body according to an embodiment of the present invention.

Where: 1. slotted flat point set screw, 2. lead screw shaft, 3. first rolling bearing, 4. optical shaft, 5. tool bar, 6. movable tool body, 7. second rolling bearing, 8. slotted cone point positioning screw, 9. tool body hexagon socket head cap screw, 10. pressure plate, 11. hexagon socket head cap screw, 12. shaft snap ring, 13. groove cutter, 14. elongated hole, 15. extension section, 16. optical shaft hole, and 17. screw mounting hole.

<7-

DETAILED DESCRIPTION It should be noted that the following detailed description is exemplary and is intended to further describe the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those generally understood by aperson of ordinary skill in the art to which the present invention belongs. It should be noted that the terms used herein are only intended to describe specific implementations and are not intended to limit the exemplary implementations of the present invention. As used herein, a singular form is intended to include a plural form unless otherwise indicated obviously in the context. Furthermore, it should be further understood that the terms "includes" and/or "including" used in this specification specify the presence of features, steps, operations, devices, components and/or of combinations thereof. As described in the background, there are deficiencies in the prior art, and in order to solve the above technical problems, the present invention proposes a tool device for rough-machining a pulley groove. In a typical implementation of the present invention, as shown in FIG. 1 to FIG. 4, a tool device for rough-machining a pulley groove, including a tool bar 5, the tool bar 5 being provided with a groove; a movable tool body 6, disposed in the groove of the tool bar 5, and linked with the tool bar 5 by a lead screw shaft 2; and at least two groove cutters 13, one of which 1s mounted at an end of the movable tool body 6, and the other 1s mounted at an end of the tool bar 5, where a distance between the groove cutters is adjusted by rotating the lead screw shaft 2. In some embodiments, the material of the tool bar 5 is 45 steel, and the material of the movable tool body is 40Cr, and the specific material can be replaced without being forcibly limited. In the above tool device, the lead screw shaft 2 links the movable tool body and the tool bar; the movable tool body has a movable space in the groove of the tool bar, and by rotating the lead screw shaft 2, the movable tool body 6 can drive a corresponding groove cutter to move, thereby making it easy to adjust the height of the movable tool body 6 relative to the cutter bar 5; in addition, the lead screw shaft 2 cooperates with the movable tool body 6 to realize self-locking; the self-locking conditions are: a lead angle a < 8, a static friction factor po = 0.1, po = tan 9, then 6 is 5°43’, and a = 4°- 4°13"; in the present embodiment, the lead angle of the lead screw shaft 2 is: a =4°. A

-8- groove cutter 13 is provided with an arc-shaped positioning groove, and the arc-shaped positioning groove of the groove cutter 13 positions by an arc-shaped positioning surface disposed at an end of the tool bar 5 and the movable tool body 6 to facilitate installation.

An end of the tool bar 5 is provided with a pressure plate 10 for pressing the groove cutter, and the pressure plate 10 is connected to the tool bar 5 through a third lock screw, so that the setting of the third lock screw can make the pressure plate press the groove cutter 13; as shown in FIG. 2, the third lock screw is a hexagon socket head cap screw 11. The groove cutter 13 is a common groove cutter.

Pulley grooves have the same outer contour diameter before machining, so theoretically, machined pulley grooves are basically the same within a margin of error.

The tool device further includes a locking member connecting the tool bar 5 to the movable tool body 6. The locking member includes a first set screw and a slotted cone point positioning screw 8 mounted on the same longitudinal face of the tool bar 5, and the first set screw is disposed on one side of the lead screw shaft 2; the locking member further includes a second set screw disposed on the other side of the lead screw shaft; the second set screw and the first set screw are perpendicular to each other; after the position of a groove cutter 13 is determined, the movable tool body is connected by the cone point positioning screw for positioning, and then the movable tool body 6 is connected to the tool bar 5 by the first set screw; the first set screw is above the slotted cone point positioning screw 8, and the two are disposed in the same straight line; the tool bar 5 is provided with a threaded hole for mounting a corresponding locking member, as shown in FIG. 5 and FIG. 6, and one side of an end face of the tool bar 5 for mounting the groove cutter is provided with an extension section 15 for protecting the groove cutter.

As shown in FIG. 8 and FIG. 9, the movable tool body 6 is provided with a screw mounting hole 17; a side portion of the tool bar 5 is provided with an elongated hole 14; the tool body hexagonal socket head cap screw 9 passes through the elongated hole 14 of the tool bar and the screw mounting hole 17 to connect the movable tool body 6; in some embodiments, a plurality of tool body hexagonal socket head cap screws 9 may be disposed to stabilize the movable tool body 6 from the side portion of the tool bar for installation.

9. The first set screw is a slotted flat point set screw 1, and in order to uniformly lock the movable tool body and enhance the stability, a second set screw is specially disposed, and the second set screw is a tool body hexagon socket head cap screw 9. The tool device further includes at least one optical shaft 4 longitudinally passing through the tool bar and the movable tool body, and the through optical shaft 4 is configured to guide the movable tool body in a longitudinal direction of the tool bar 5; in some embodiments, two optical shafts 4 are disposed, the optical shafts 4 are disposed on both sides of the lead screw shaft 2, and the optical shafts 4 are disposed on an outer side of the locking member; a shaft snap ring 12 is disposed between the optical shaft 4 and the tool bar 5; the movable tool body 6 is provided with an optical shaft hole 16 for the passage of the optical shaft; the optical shaft 4 is disposed in parallel with the lead screw shaft 2; the optical shaft 4 and the tool body hexagonal socket head cap screw 9 are disposed perpendicular to each other.

Through the disposing of the optical shaft 4 and the locking member, the movable tool body 6 is positioned and limited to five degrees of freedom by the end face of the tool bar with the scale and two inner side wall faces of the tool bar, that is, the tool bar 5 is provided with an open slot, and the open slot disposes the movable tool body 6 to limit partial freedom of the movable tool body 6; the height of the open slot 1s greater than the height of the movable tool body 6, which facilitates the adjustment of the height of the movable tool body; in addition, the slotted cone point positioning screw 8 limits one degree of freedom, thereby achieving the positioning of the movable tool body 6. One end of the lead screw shaft 2 protrudes from the tool bar 5; an end of the lead screw shaft 2 is provided with a nut to facilitate the rotation of the lead screw shaft 2; a bearing is disposed between the lead screw shaft 2 and the tool bar 5, and the bearing is a rolling bearing; specifically, the bearing includes a first rolling bearing 3 and a second rolling bearing 7; the lead screw shaft 2 and a bearing inner race as well as a bearing outer race and the tool bar 5 are connected by interference fitting.

The tool bar 5 is provided with a scale line at the end with the groove cutter 13; as shown in FIG. 4, the disposing of the scale line makes it easy to determine the position of the groove cutter 13; a center distance between points of the two groove cutters can be adjusted in the range of 10-25 mm, which is suitable for the machining of various types of pulley grooves.

The lead screw shaft 12 bears a small force in a vertical direction; both ends of the lead screw shaft 12 are connected with the bearing by

-10- interference fitting, and the position of the movable tool body can be manually adjusted.

The tool device provided in the present embodiment can be applied to a vertical numerical control lathe and a horizontal numerical control lathe, and to rough-machine apulley groove, the tool device is mounted on a tool holder of the lathe by manually adjusting the spacing of the two groove cutters based the scale line and locking according to the size and position requirements of the pulley groove.

In order to overcome the deficiencies of the prior art, the present invention further provides a method for rough-machining a pulley groove, which uses the tool device for IO rough-machining a pulley groove.

The foregoing is merely illustrative of the preferred embodiments of the present invention and is not intended to limit the present invention, and various changes and modifications may be made by those skilled in the art.

Any modifications, equivalent substitutions, improvements, and the like within the spirit and principles of the invention are intended to be included within the scope of the present invention.

Claims

S11 - Conclusions

A tool device for roughly machining a pulley groove, comprising: a tool bar, the tool bar having a groove; a movable tool body placed in the groove of the tool bar and connected to the tool bar by a spindle shaft, the spindle shaft cooperating with the movable tool body to realize a self-locking spiral lifting mechanism; and at least two grooving cutters, one of which is mounted on one end of the movable tool body, and the other is mounted on an end of the tool bar, wherein a distance between the grooving cutters is adjusted by rotating the spindle shaft.

The tool apparatus for coarse machining a pulley groove according to claim 1, further comprising a locking element coupling the tool bar to the movable tool body.

The tool apparatus for rough machining of a pulley groove according to claim 2, wherein the locking element comprises a first set screw and a positioning screw with a cone tip mounted on the same longitudinal side of the tool bar and the first set screw is placed on one side of the spindle shaft ; wherein the locking element further comprises a second set screw located on the other side of the spindle shaft.

The tool device for coarse machining of a pulley groove according to claim 3, wherein the first set screw is a flat pointed set screw and the second set screw is a tool body hexagon socket screw.

The tool apparatus for coarse machining a pulley groove according to claim 1, further comprising at least one optical axis extending longitudinally through the tool bar and the movable tool body

S12 - goes.

The tool device for coarse machining of a pulley groove according to claim 1, wherein one end of the spindle shaft protrudes from the tool rod and a bearing is interposed between the spindle shaft and the tool rod.

The tool device for coarse machining of a pulley groove according to claim 1, wherein one end of the tool bar is provided with a pressure plate for applying pressure to the grooving cutter and the pressure plate is coupled to the tool bar by a third locking screw.

The tool device for rough machining of a pulley groove according to claim 1, wherein the tool bar has a scale line at the end with the groove cutter.

The tool device for coarse machining of a pulley groove according to claim 5, wherein the optical axis is located on both sides of the spindle shaft.

A method for coarse machining of a pulley groove, using the tool device for coarse machining a pulley groove according to any one of claims 1-9.