JPS60500607A - Machining method and equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Processing method and equipment 1 Soho Nao 1 The present invention relates to machining, and more particularly to reducing power levels and improving tool life. Metalworking operations such as turning, poling, shaping and milling with increased efficiency The present invention relates to an improved method and apparatus for carrying out the work.

A cutting tool generally includes a holder and one or more cutting tools. each cutting insert having one or more cutting inserts. The upper force has one surface terminating in the cutting edge. The retainer is locked in place. formed with a socket for clamping the fitting insert, Inserts are used in metal processing operations such as turning, polling, shaping and milling. so that the cutting edge of the cutter engages the workpiece and removes metal chips. It has become. The chip consists of multiple metal flakes, and these metal flakes are different from the workpiece material. When they are cut apart, they slide against each other along the shear plane. These metals that make up the chip Such shearing motion of the flakes generates significant amounts of heat. In fact, in chips The heat generated along the shear plane is absorbed by the cutting edge of the insert into the workpiece. The heat generated by abrasion on contact can be even greater.

2 Special cover Sho GO-500GO7 (4) The main cause of defects in cutting inserts of machine tools is the cutting insert. abrasion between the cutter and the workpiece, a problem known as cratering. evening.

The crater is caused by the tremendous heat generated in the chip and the cutting of this chip. This occurs by engaging the insert. Is the metal that forms the chip the workpiece material? When sheared, this metal frictionally engages the top surface of the insert and, if present, It also frictionally engages the socket portion of the tool holder that secures the seat in place.

Many inserts have a chip break groove on the top surface, and this chip break groove is the insert surface and the socket of the tool holder. It is provided so that it can be bent upwardly at the top part. However, Even if the insert is equipped with a break groove, the small part on the top surface of the insert inside the cutting edge At least a portion is in frictional engagement with the hottest portion of the tip. This frictional engagement and Due to the tremendous heat generated in the top of the insert, the material melts on the top surface of the insert. This results in the formation of grooves and craters in the insert. . When the depth of these craters is reached, the insert as a whole is Cracks develop along the cutting edges and sides due to abrasion with the workpiece. This immediately leads to problems. In recent years, this crater The development of ultra-hard metals such as titanium and their versatile use has made This is becoming a problem.

Cutting inserts to avoid cratering and wear interface, and a follower for cooling and lubrication between the cutting insert and the tip. Previous attempts have provided only marginal improvements in tool life and efficiency. One method in technology is to use inserts made of high-strength metals such as carbide steel. The goal is to form a Carbide inserts are very hard but brittle and easily crack. The effectiveness is low. Hardened to improve insert lubricity and strength Materials such as ceramics are used and cutting inserts are Various low friction coatings have been developed for coating. In fact, even tool life Many inserts are now manufactured with multiple coatings to extend the ing. Development of better materials and coatings for cutting inserts Although the tool life has been improved to a certain degree, depending on the speed and feed rate, especially titanium For aluminum and similar hardened materials, the best cutting inserts are often should be replaced by

Improved materials and coatings used in the manufacture of cutting inserts In addition to cooling, a low-pressure flow of any one of a wide variety of refrigerants is used. Cutting is performed using cooling operations such as cooling the tool holder and workpiece. Insert-workpiece interface and between cutting insert and tip Attempts have been made to extend tool life by cooling and lubricating the tool. typical Specifically, the number α to the number of cm (several inches) above the cutting tool and workpiece. A nozzle is placed at the Orient to the upper surface of the holder and the resulting chip. known as sprinkle cooling This technique uses a sock to hold the top of the tip and the cutting insert in place. Only the part of the tool holder near the edge of the socket is effectively cooled.

The underside of the tip in contact with the cutting insert, and the extremely high heat actually The resulting interface between the cutting insert and the workpiece is not affected by this coolant. It is left unfilled. The reason for this is that the operating speeds of modern milling and turning machines are The heat generated in the area of the cutting edge of the insert and the insert This is because the refrigerant evaporates before it flows near the cutting edge of the cutter. Ru. In fact, the feed rates and speeds at which modern milling and turning machines can operate are higher than traditional milling and turning machines. Far exceeds the limits of machining through insert design and sprinkling cooling technology. Ru.

In some instances, sprinkle cooling results in thermal damage to the cutting insert. this is Store in very hot areas immediately surrounding the cutting edge and in the socket of the tool holder. There is a very large temperature gradient between the cold interior of the cutting insert and the This is caused by the occurrence of The refrigerant enters the cutting insert before it evaporates. opposite to the cutting edge which cannot reach the minute and is therefore held in the tool holder. Only the side inserts are effectively cooled. Cutting edge and cut Extremely large temperature differences between the insert and the rest of the insert can cause thermal damage. It's a matter of time.

One method to improve upon conventional cooling methods is U.S. Patent No. 2.6, issued to Pivot. ! 53.517.

This patent covers the workpiece and the cover on the lower side of the insert where the chip is formed. At a position between the rear end or trailing edge of the fitting insert, there is a teaches a method and socket for applying coolant at a speed of approximately 260 feet). Ru. This method is also described in German Patent No. 3.004,166. this cold The problem with the heating method is that craters form on the cutting insert and the temperature rises. Coolant is introduced between the elevated part, i.e. the top surface of the insert and the bottom side of the generated chip. It is not possible. The tip guides the refrigerant to the underside of the cutting insert. and the cutting insert.

Another method is taught in U.S. Pat. No. 4,302.135 to Lilly. Ru. Lily's rotary cutting tool has a shank part and a cutting part. including the formed body and extending longitudinally through the shank and cutting section. The hole is extended, with an inlet in the shank and an outlet in the cutting part. It is. A space is placed on the bottom of the cutting part so that it extends outward in the radial direction of the exit. grooves are formed and these grooves are for mounting cutting inserts. It terminates in a socket. These grooves are formed within the cutting insert is aligned with the groove leading to the cutting edge of the insert. The refrigerant is Pumped through a central passage and directed radially outward through a groove, the After the cutting insert, the tool body creates a radius along the groove in which the coolant flows. deflected in the direction

Lilly's rotary tool provides high height to the cutting insert-workpiece interface. Attempts have been made to direct the flow of high velocity, high pressure refrigerant. Unfortunately, Lilly's patent The configuration offered in Cutting edge - cannot reach the interface of the workpiece or the chip in that area Ta. In Lilly, the flow of refrigerant from the central passage to the cutting insert is Not qualitatively limited. Once the refrigerant is released from the center passage outlet, the pressure and speed will be significantly reduced. The reason for this is that the cutting part of Lily's tool The cross-sectional area at the base is larger than that of the center hole and has already been cut by the tool. Is the flow of refrigerant released to the atmosphere as each insert rotates into the defined area? It is et al. This significant reduction in pressure and velocity allows for The refrigerant flow that It easily evaporates before reaching that area of the surface. Hence Lily's invention is essentially sprinkle cooling, in which the cooling achieved is based on the cover of the body. Cutting insert immediately adjacent to the end of the radial groove in the cutting section the cutting edge that has reached that point and/or the boundaries of the workpiece. Limited to chips that advance outward from the surface.

The conventional cutting insert design and cooling and lubrication methods described above; or low, medium or hard alloy gold using any other known method When machining metals, the machining speed that can be achieved is higher than the permissible performance of the machine tool. Noticeably small. For example, we can machine alloy steel materials used in aircraft jet engines. Typically capable of tools used to machine 16.4 am per minute (10 0.0254 to 0.025mm per rotation to cut up to 1 27m (0,0 01~0. Surface speed is 6 to 61 per minute with chip load in the range of 0.005 in. 711 (20-200m). These machining speeds These are the typical speeds recommended for tools that have been available in the past; Machining at a speed far beyond the cutting speed will result in a high load that far exceeds the strength of the cutting insert. and severe deterioration, leading to tragic failures. . The speed of such machining is faster than existing cutting inserts and sprinkle cooling. There may be reasons for using the Further improvements are made to match, and processes such as electrochemical etching and grinding are It is desirable to avoid using machining methods that increase costs.

Another problem known in the machining tool industry is cutting inserts. the tip and the retainer. Preferably, the tip is 50.8# (2in) or less if sheared from the workpiece must be broken into pieces. If the chip remains in a continuous state without being broken, Once formed, the chip will fit into the cutting insert, tool holder and/or may wrap around the workpiece and cause damage to the tool, or may cause the insert to become compressed. At least periodically carry out machining operations to clean the parts that have been scraped and bunched up. must be interrupted.

Previous attempts to solve this chip removal problem have included chip breaking grooves. Limited to various designs of cutting inserts, this chip break groove is A groove formed on the top surface of the cutting insert that is immediately adjacent to the cutting edge. be. The chip breaking groove engages and cuts chips sheared from the workpiece. bending the tip upward away from the surface of the insert, which causes the chip to fracture. Do what you want. Due to the design of the chip breaking groove in the application of Although acceptable performance can be achieved, the material, machine type, cutting depth, and feed rate and for variations in machining operations such as speed differences in all applications. It is practically impossible to design a single chip break groove that would be effective. This thing is , intended to tolerate the variety of machining conditions encountered in the industry. This is evident from the large number of chip break groove designs currently available. If I could Even selecting the appropriate cutting insert for a particular application can be expensive. This creates difficult problems.

λ prisoner 11 According to the broad concept of the invention, the upper surface of the cutting insert and the generated chip Coolant is applied from below the chip at high speed between the bottom surface of the chip and the cutting, poling, Machining operations such as turning, milling, grooving, threading or drilling Methods and apparatus are improved to perform.

According to a more particular concept of the invention, chips generated during machining operations are effectively While the workpiece is cooled and broken into pieces of relatively short length, the machining operation The surface of the cutting insert to be machined is lubricated and cooled. A method and apparatus for machining material is provided. This device has at least a tool holder having a barbed front end formed with one release orifice; . The tool holder is a cutting insert having a surface terminating in a cutting edge. Contains a socket for attaching a seat. Cutting insert rotates The cutting insert engages with the workpiece to form a chip. and the release orifice. cutting insert The top surface and the bottom surface of the chip allow refrigerant to be ejected from the release orifice at high velocity. Equipment will be provided for this purpose.

According to a more particular concept of the device of the invention, the cutting operation is carried out by a predetermined feed rate. and depth of cut.

As is well known, the feed rate is moved by the tool holder each time the workpiece rotates. distance. Preferably, the release orifice formed in the retainer is so that the distance from the cutting edge is approximately 6 to 10 times the feed rate, or Separate the workpiece by a distance approximately 6 to 10 times the distance moved by the holder each time the workpiece rotates. The cutting insert is attached to the holder so that the cutting insert is attached to the holder. release The orifice may have a circular or non-circular cross section.

If it is circular, it will be approximately equal to the depth cut by the cutting insert. Preferably, the release orifice is formed to a desired diameter. Orifice that is non-circular is formed in a cross section with a short axial length and a long axial length. Orifice that is non-circular The long axial length of the cutting insert is approximately equal to the cutting depth. is preferable.

According to yet another concept of the invention, means and tools for delivering coolant to a tool holder. A means for directing refrigerant through a retainer and ejecting it from a release orifice at high velocity. is provided. One end of the refrigerant is connected to the holder and the other end is connected to the high pressure bottle 1. is sent by a conduit connected to the tube. Pumps and conduits run at speeds of 6 to 61 m/s (2 Dimensioned to deliver coolant to the tool holder at a velocity ranging from 0 to 40 feet) is preferable. The refrigerant is routed inside the tool holding area through a main passage connected to a conduit at one end. is routed through an intermediate passageway disposed between the passageway and the release orifice. preferably The wall of the intermediate passage is tapered from the main passage to the release orifice so that it has a conical shape. The paper is shaped. Angle at the release orifice formed by the wall of the intermediate passage is preferably about 20 degrees or less. Assuming that the release orifice has a circular cross section The length of the intermediate passage is then preferably approximately 20 times the diameter of the release orifice. stomach. Additionally, the walls of the intermediate passageway may be highly polished by any of a variety of known methods. It is lifted up. The dimensions, conical shape and polished wall surface of the intermediate passage are the same as those of the main passage! j Once the refrigerant velocity is increased to about 10 times the flow velocity in the conduit between the main passage and the release orifice. This depends on the specific machining conditions, as detailed below. It is determined that

According to yet another concept of the present invention, a machining method is disclosed, which includes: A high-velocity, high-pressure refrigerant jet is applied to the top surface of the cutting insert and this insert The lower part of the chip and the lower part of the chip are sheared from the workpiece by Directed from a position covered by.

Here the release orifice formed in the tool holder is inserted into the cutter of the cutting insert. Position 2 in relation to the edge The chips generated by the cutting operation are released into the orifice. It is placed in a position that overlaps the top. In reality, the envelope formed by the workpiece The surrounding space or gap is located between the open orifice, the top surface of the cutting insert, the tip and and the lower periphery of the tool holder. High pressure and high velocity from the release orifice The coolant injection is limited to this gap, and the energy required until the chip is cut from the workpiece is reduced. – losses are kept to a minimum.

Several advantages over traditional machining tools and cooling techniques include high-velocity, high-pressure refrigerant A limited area or space below the chip where the jet is forming from the workpiece. This is provided by the machining method according to the invention in which the gap is injected. formed The refrigerant jet is maintained at high pressure and high speed just below the growing chip. Cutting inserts are caused by abrasion and formed chips at the interface of the workpiece. It has been found that the thermal barrier created by the shearing motion in the cup can be passed through.

Larger area space provided below the chip and between the chip and the refrigerant Due to the extreme temperature difference, rapid heat transfer occurs between the chip and the coolant. Tsk The temperature drops rapidly, within 0.1 seconds or less, and the semi-plastic lattice structure It is believed that the structure is actually solidified as a molecular structure in which the structure is fragmented. This thing is This results in the formation of a very brittle chip, which is different from a normal lattice structure chip. This means that it can be easily broken from the workpiece. Insert-workpiece interface , and in the process of conducting heat from the chip, some of the refrigerant evaporates. refrigerant jet is injected into an essentially closed gap, continuously from the release orifice. In addition to the pressure provided by the new refrigerant being injected, evaporation occurs below the chip. The refrigerant generated generates considerable vapor pressure. through evaporated refrigerant and conduits The resultant line pressure of is accumulated in the closed gap below the tip, which The material is broken from the workpiece and removed from the cutting area.

At least some of the refrigerant jet cuts through this closed gap without evaporating. It was found that the thin film flows at high speed along the top surface of the cutting insert l~. has been done. This thin film of refrigerant performs two functions. First of all, this cold The amount of media film reaches the cutting edge-workpiece interface and the cutting edge It flows between the microscopically irregular interstitial surfaces of both the edge and the workpiece. this child It provides enough lubrication to remove the heat generated there. Secondly, This thin coolant film on the top surface of the cutting insert is Apply dynamic fluid pressure to the tip to lift it out of contact with the insert. Shows a tendency to push people towards others.

This reduces wear on the cutting insert and allows the tip to engage the insert. and reduce craters that occur.

The method and apparatus according to the invention involves true cooling versus traditional sprinkle cooling techniques. The machining process is accomplished using the same method. High-speed, high-pressure refrigerant jets reduce the amount of chips generated. guided into the lower part and confined within an essentially sealed and closed gap; The pressure and velocity are then maintained with minimal loss. High speed and high pressure refrigerant jet Guide the cutting edge below the tip and close to the cutting edge-workpiece interface. means that the refrigerant jet can pass through the vapor and heat barrier created in the cutting area. This avoids the cutting edge-workpiece interface and extremely high This results in effective cooling of the chip where heat is generated. Sprinkle cooling is done by this steaming. Therefore, the cutting edge-workpiece interface and chips cannot pass through the air barrier. It is not possible to achieve cooling in the immediate vicinity.

Drawing description The structure, operation, and advantages of the present invention may be understood by considering the following description in conjunction with the accompanying drawings. It will become even clearer. In the drawing, FIG. 1 shows the rotation according to the present invention in the process of cutting a cylindrical stock piece. Partial perspective view, heavily exaggerated for illustrative purposes, showing the retainer: FIG. A partial perspective view of the rotary holder shown in Figure 1; Figure 3 is an enlarged view of Figure 1 at the cutting part. Large side view; Figure 3a is an enlarged side of Figure 1 at the beginning of cutting to produce chips. Front view: Figure 3b is a third diagram showing a state in which the chip generated is in contact with the front end of the tool holder. Side view shown in Figure a: Figure 3C shows the generated chips moving along the top surface of the tool holder. The side view shown in Fig. 3a shows the state in which the sprinkler is in motion; and Fig. 4 shows the prior art sprinkling. FIG. 3 is a side view similar to FIG. 3 of the cooling device.

Detailed description of the invention Referring now to the drawings, a tool holder 10 can be used to remove a workpiece 12 according to the method of the present invention. Shown for machining. The workpiece 12 is placed in a chuck (not shown). This allows the workpiece 12 to be rotated in the direction shown in FIG. ing. The tool holder 10 is a turning holder for turning operations, and the tool holder 10 is a turning holder for turning operations. Machining methods can be used for other operations such as milling, polling, cutting, and grooving. The tool holder 10 shown here is applicable to machining, threading and drilling. is for illustration purposes only. The tool holder 10 includes a support bar 14 with a cutter attached to the support bar 14. receives a cutting insert having an upper surface 17 terminating in a cutting edge 19; A cutout 16 is formed for entry. cutting insert 18 is secured within this cutout 16 by a clamp 20, and this 1. The clamp of along the edge of the support bar 14 from the cutting edge 19 of the insert 18. It extends to far away locations. Clamp 20 is screw 22 or other It is removably secured to the support bar 14 by any suitable means.

A boat 24 is formed at the end of the clamp 20 opposite the cutting insert 18. The boat 24 has a fitting connected to one end of the refrigerant conduit 28. 26. The other end of the refrigerant conduit 28 is connected to flow and pressure channels as detailed below. It is connected to a high pressure pump 30 (shown schematically) having a power characteristic. release orif The pipe 32 is formed at the front 21 of the clamp 20 on the opposite side from the refrigerant conduit 28.

Although one release orifice 32 is shown in the drawings, Two or more release orifices 32 may be formed in the clamp 20 accordingly. It is expected that. Refrigerant is passed from the refrigerant conduit 28 to the release orifice 32 through the refrigerant conduit 28. A main passageway 34 connected to one end of 28 and the main passageway 34 and the release orifice. It is passed through the clamp 20 through an intermediate passageway 36 formed between 32 and 32 . During ~ The inner wall surface 37 of the interstitial passage 36 is first treated with diamond paste and then treated with a known It is highly polished by applying a substance such as silicon glass through a vapor deposition process. It is preferable that it be raised. The inner wall surface 37 of the intermediate passage 36 is approximately 10 microns thick. The surface should not be too rough.

Pump 30, refrigerant conduit 28, and passages 34, 36 provide high velocity, high pressure refrigerant jets. A refrigerant conduit arrangement is configured such that the refrigerant jet is emitted from the release orifice 32. Injected. Characteristics depending on the type of material that makes up the workpiece, and the rotation of the workpiece A pump with a specific pressure and flow rate depending on the speed and feed rate of the tool holder 10. 3Q is selected. An example of how to select a pump 30 for a particular application is below. Explained in detail. The refrigerant conduit 28 is sized based on the flow characteristics of the pump, and has a diameter of 6 to 1 Pump with a speed of 2.277L/5 (20-40 f/s (7 seconds)) This is done to create a coolant flow from the pipe 3o to the boat 24 of the clamp 20.

At this speed, the refrigerant cools with minimal turbulence and small losses due to resistance. It has been found to flow along conduits. In a preferred embodiment of the invention, , the diameter of the main passageway 34 formed in the clamp 20 is approximately equal to the diameter of the refrigerant conduit 28. stomach. This means that the refrigerant in the main passage '36 of the tool holder 10 is 6 to 12.2 m/s. (20-40 f/s) and ensure to avoid turbulence. conduit 28 and the main passage 34 are not required to have a circular cross section, but machining of the tool holder 10 for ease of construction and the ability to use standard conduits and hoses. A circular cross section is preferred.

The refrigerant that has entered the intermediate passage 36 is 6 to 12.2 m/s in the main passage 34 <20 to 4. Of/s) typically exceeds 122 m/s (400 f/s) The refrigerant generator is accelerated to a velocity and injected from the release orifice 32 on its inner wall surface 3. 7 is preferably tapered from the main passage 34 to the release orifice 32. stomach. As shown in the drawings, the main passage 34 and the intermediate passage 36 are of the same straight line. Ru. This means that the refrigerant is injected from port 24 entering the opening 10. The flow should flow in a straight line up to station 32. Straight flow given by passages 34.36 Body passages should be designed to minimize turbulence and resistance, otherwise the refrigerant flow would be slow. This prevents achieving the desired velocity at the release orifice 32. release orifice The acute angle formed by the wall surface 37 of the intermediate passage in the space 32 is 20 degrees or less. , is preferably tapered gradually along the length of the intermediate passageway 36. This helps prevent turbulence as the refrigerant is accelerated toward the release orifice 32. Two. To ensure sufficient acceleration of the refrigerant, the intermediate passage 36 has an open orifice. Preferably, the length is approximately equal to 20 times the diameter of the base 32. If released If the orifice 32 is not circular in cross section, calculate its area and then The length is made to be approximately 20 times the diameter of a circular cross section of the same area. release orifice 32 The diameter or major axis diameter is shown exaggerated in Figure 1 for illustrative purposes. Preferably, the cutting depth D is approximately equal to the cutting depth D. release orifice 32 The total cross-sectional area of the refrigerant jet 38 is determined by the energy of the refrigerant jet 38 required for a particular cutting operation. and an example is given below, in which the release The orifice dimensions are calculated for the particular application.

The front end 21 of the clamp 20 and the release orifice 32 are connected to the cut of the insert 18. The cutting edge 19 is spaced apart from the cutting edge 19 by a gap 40 in which the workpiece 12 is Depends on the feed rate during machining. As is well known, shown in the drawing The feed rate in turning operations is as follows: It is the distance moved along the longitudinal axis of the material. In a preferred embodiment of the invention, the The distance 40 between the cutting edge 19 and the release orifice 32 is approximately 6 to 10 times the range, i.e. for each revolution of the workpiece 12 along the longitudinal axis of the workpiece. The range is 6 to 10 times the distance of the tool holder 1o or insert 18 to be moved. Ru.

Before describing the operation of tool holder 10 according to the method of the present invention, a typical machining operation will be described. It is important to focus on the concepts involved in the process and the issues that arise. well known As shown, the cutting edge 19 of the insert 18 engages the workpiece 12. Then, the metal is cut in the shape of the tip 42. This chip 42 is attached to the workpiece 12. The tip 42 has a width equal to the cutting depth D made against the tool. The distance that the holder 1o moves laterally along the workpiece 12 for each rotation of the workpiece 12 equal to distance.

As best shown in Figures 3b and 3c, the tip 42 is well defined. It is actually formed by shearing the metal on the surface of the workpiece 12 along the shear plane 44. be done.

The chip 42 comprises a plurality of individual thin metal pieces 46 that are connected to the insert. When the workpiece 12 rotates in engagement with the cutting edge 19 of 18, shearing occurs. Mutual slippage occurs along the cross section 44. Thin pieces 46 of the chip 42 relative to each other The location of is exaggerated in the drawing for illustration purposes; present.

The immediate surrounding cutter surrounding the cutting edge 19 and the underside of the tip 42 There are a number of sources of heat generated in the ring section 48. Heat causes abrasion and cuts with the workpiece 12. Frictional contact of the cutting edge 19, the tip 42 contacts the top surface 17 of the insert 18 and that the abutting portions 46 of the tip 42 are aligned with each other along the shear plane 44. Heat is generated as a result of the friction that occurs when sliding. cutting edge 19 - The temperature at the interface of the workpiece 12 is 816°C (1500°F) or higher. and the piece 46 forming the chip 42 moves along the shear plane 44. The temperature of the chip 42 caused by this decreases when it is sheared from the workpiece 12. That's all.

Referring to Figure 4, a typical prior art tool design using sprinkle cooling A cutting operation carried out by is illustrated. According to this prior art configuration S1 For example, the large heat generated in the tip 50 causes a crater in the cutting insert 51. This causes the occurrence of defects, which leads to problems. The tip 50 is attached to the workpiece 52. When sheared from the outer surface, these are transferred along the top surface of the cutting insert 51. move. The heat generated by the tip 50 is transferred to the upper surface of the cutting insert 51. Along with the heat generated by the frictional engagement with the cutting insert 51, the metal Some of it melts and is carried away, forming a depression or crater. It is. Craters or pockets of metal that are removed are cut into cutting inserts. In combination with the abrasive contact between 51 and the workpiece 52, the cutting insert The size is large enough to cause problems with the port 51.

Recognizing these concepts of cutting operations, the main purpose of the present invention is to Removes as much heat as possible from portion 48 and allows tip 42 to cut in. The upper surface 17 of the seat 18 should be in close contact with the upper surface 17 of the seat 18.

These objectives are likely to be accomplished by the apparatus and methods provided herein. It is best explained with reference to the

Now, referring to FIGS. 3 to 3C, the cutting operation according to the method of the present invention is as follows. It is done as below. Pump 30 is activated and refrigerant jet 38 is driven to the open orifice. When sprayed from the base 32, the cutting edge 19 of the insert 18 is first It is brought into contact with the workpiece 12 and moved inward by a preset depth D. Tool holder 1 0 is then the preset feed rate, i.e. per axial distance per each revolution of the workpiece. It is advanced axially along the longitudinal axis of the workpiece 12. of the surface of the workpiece 12 The metal is sheared by the cutting edge 19 and the tip 42 is inserted into the insert 18. Start moving along the top surface 17 (see Figure 3a). At this time, the chip 42 is in contact with the top surface of the insert 18 and the refrigerant injected from the release orifice 32 Jet 38 strikes the front of tip 42, its top surface and workpiece 12.

The machining process is as shown in Figure 3b. The tip 42 is attached to the clamp 20. It continues along the upper surface 17 of the cutting insert 18 until it hits the front end 21. Proceed. As best shown in FIG. 2, the front end 21 of the clamp 20 is tapered. - shaped and clamped directly onto the top surface 17 of the insert 18. Kula Once in contact with the front end of clamp 20, tip 42 is angled into clamp 20. It is bent upwardly onto surface 23 and overlaps release orifice 32 . Figures 3b and 3c When the tip 42 engages the angled surface 23 of the clamp 20 as shown in FIG. A substantially sealed enclosed space or gap 60 having six sides or walls is open. It is formed around the orifice 32. The gap 62 is between the workpiece 12 and the clamp 20. Angled surface 23, lower surface 41 of chip 42 and upper surface 17 of insert 18 formed by. As seen in Figures 3-3C, the workpiece 12 is placed in the release orientation. A wall surface facing the gap 32 is formed, and the top and bottom walls of the gap 60 are each chipped. formed by the lower surface 41 of the clamp 42 and the upper surface of the insert 18; The surface 23 with an angle of 0 forms the wall surface of the gap 60 facing the cutting part of the workpiece 12. Form. The edge of the chip 42 extending outwardly from the workpiece 12 When the insert partially contacts the clamp 20, it forms a release area 61 of the gap 6o, and the insert 18 (see FIG. 1). however, The tip 42 is twisted toward the upper surface 17 of the inseat 18 in the direction of the open area 61. 61, thereby minimizing the loss of refrigerant through the open area 61. chip 42 The end portion 43 still attached to the workpiece 12 is broken, as described below. The angle of the clamp 20 is maintained until the chip 42 is completely separated from the workpiece 12. 23.

Cutting edge 19 in depth 42 and cutting part 48 - workpiece In order to effectively remove heat from the interface of the It must actually reach the cutting part 48 without completely evaporating. It has been discovered that Lubrication of the cutting edge 19-workpiece 12 interface and improved resistance to contact between the top surface 17 of the insert 18 and the tip 42. The improvement relies on the continuous introduction of high velocity refrigerant jets 38 into the cutting portion 48. Exists.

In the initial phase of the cutting operation shown in Figure 3-4, the pressure of the refrigerant jet 38 is The force is significantly reduced and is directly dependent on the discharge from the release orifice 32. child The reason is that the refrigerant jet 38 is not restricted within the surrounding gap and is open to atmospheric pressure. This is because that. At this stage, the coolant jet 38 is directed along the top surface of the chip 42. It mainly flows. However, when the tip 42 is removed from the clamp 20 as shown in FIGS. 3b and 30, When it advances until it contacts the front end 21, it overlaps the release orifice 32 and seals within the gap 60. surround. A significant loss in refrigerant velocity and pressure is directed outside the gap 60. is generated by the side, ie, the release area portion 61, but is injected from the release orifice 32. The refrigerant jet 38 is substantially confined within the gap 6o. Actually the gap 60 is closed. The cutting portion 48 forms an extension of the closed intermediate passageway 36 within the lamp 20. The velocity and This is done so that the pressure is maintained.

The distance between the first and first release fins 32 and the cutting edge 19 of the insert 18 As mentioned above, the distance 40 is important for proper operation of the tool holder 10. It has been found that Distance between release orifice 32 and cutting edge 19 The distance 40 is in the range of approximately 6 to 10 times the feed rate of the machining operation, that is, the feed rate of the workpiece 12 is The range is 6 to 10 times the distance traveled in the axial direction by the tool holder 10 during rolling. is preferred. Experience has shown that when the release orifice 32 approaches the cutting edge 19 Once this occurs, the refrigerant jet 38 indicates that it is unable to displace the bottom surface of the chip 42 has been done. The tip 42 and workpiece 12 are provided with a burr that deflects the coolant jet 38. Instead of forming a flow under the tip 42, a turbulence is generated. Cool Positioning the release orifice 32 too far from the cutting edge 19 , necessary to form the gap 60 and relative to the angled surface 23 of the ramp 20. Failure to form a proper seal. Refrigerant jet 38 is initially formed when chip 42 is formed. has been found to at least partially cool its top. This is This creates a temperature difference between the top and bottom surfaces 41 of the chip 42, which causes the chip 42 to It shows a tendency to bend in the opposite direction. If clamp 20 is cutty of insert 18 If the tip 42 is positioned too far from the clamp edge 19, the tip 42 will It bends upward away from the insert 18 before contacting the marked surface 23. That's what happens. Preferred position of release orifice 32 relative to cutting edge 19 The positioning is such that the tip 42 is placed on the angled surface of the clamp 20, as described in detail above. To prevent the insert 18 from bending upward from the insert 17 without contacting the insert 23. It is.

Some advantages include the use of high-velocity, high-pressure refrigerant jets 38 in cutting inserts 18. Limited release of the lower part of the chip 42 between the upper surface 17 and the lower side 41 of the chip 42 This is achieved by guiding from the position of the orifice 32. under these conditions , the high-velocity refrigerant jet 38 generated is responsible for the formation of the chip 42 and the cutting edge. The cutting portion 48 is heated by the contact between the edge 19 and the workpiece 12. It has been found that a vapor barrier is formed within. occurs below the chip 42. One advantage of reducing the heat generated is that melting of the insert 18 is significantly reduced; This reduces cratering and cutting edge abrasion. This means extending the life of the insert.

A second benefit is obtained by drawing heat away from the tip 42 within the cutting portion 48. The points relate to chip removal.

Refrigerant jet 38 is confined within gap 60 so that very hot chips 42 and Effective heat transfer occurs between the insert 18 and the ambient temperature refrigerant jet 38 . Since the lower surface 41 of the chip 42 provides a large area within the gap 60, the lower surface 41 of the chip 42 It has been found that a significant reduction in heat is achieved in a very short time. refrigerant di The jet 38 moves the tip 4 along the shear plane 44 formed between the individual thin pieces 46. It is believed that it actually penetrates within a short distance of 2. Chip 42 saw The rapid cooling of the chip 42, believed to occur in 0.1 seconds or less, is divides the lattice structure of The chip 42 has a semi-prepared lattice structure during machining operations. When heated until it becomes plastic and rapidly cooled by the refrigerant jet 38, it becomes semi-plastic. It is believed that the plastic structure is solidified into fragmented molecular structures.

The tip 4 has a molecular structure divided at least within the cutting portion 48. 2 is solidified, creating a brittle structure with significantly reduced toughness and bending strength. put out. When the chip 42 is in a brittle state, the chip 4 attached to the workpiece 12 2 and remove the tip 42 from the cutting portion 48. It requires only a little force.

The chip 42 is broken and removed from the workpiece 12 by the high pressure generated within the gap 60. be removed. A portion of the refrigerant jet 38 is caused by the heat generated within the cutting portion 48. and evaporate. Since the gap 60 forms a substantially sealed space, The evaporated refrigerant jet 38 generates high pressure, which is applied to the chip 42. Granted.

Furthermore, the fluid is continuously injected from the release orifice 32 into the sealed gap 60. Pressure is applied by the new refrigerant. Conduit pressure and refrigerant jet 38 vapor The combined pressure causes the end 43 of the tip 42 to break or break from the workpiece 12. and sufficient to remove the entire tip 42 from the cutting portion 48. Most In this application, the breakage of the chip 42 occurs between the positions shown in sections 3b and 3c. 42 is achieved when moving. As a result of this, a relatively short chip 42 is created. These will be released from the cutting part 48 by pressure. be pushed away. A feature of the invention is that the chips typically do not break in short lengths. , formed as long sections that wrap around the tool holder and cause jamming problems. It offers important advantages over existing devices such as

Yet another advantage is that the solution located within the essentially closed gap 60 below the chip 42 This is provided by directing a refrigerant jet 38 from a discharge orifice 32 . refrigerant di At least a portion of the jet is arranged such that the front end of the tip 42 is inserted into the insert as shown in FIG. 3C. When lifted above the cut surface 17, the cutting insert 18 It has been found that this movement occurs. Refrigerant jet 38 flow or thin film Layer 62 forms a hydrodynamic fluid support, which supports top surface 17 of insert 18. to prevent the chips 42 from coming into contact with each other. Fluid formed by film layer 62 Dynamic fluid support moves the tip 42 up and away from the top surface 17 of the insert 18. This creates an abrasive contact that can cause cratering and damage. avoid or at least reduce frictional contact between the two that would otherwise occur. Refrigerant fi The layer 62 is continuous along the top surface 17 of the insert 18 and extends into the cutout of the insert 18. Flow through microscopic surface disturbances in the cutting edge 19 and the workpiece 12. This provides lubrication to reduce frictional contact between the two during cutting operations. It is uno.

The reduction of friction provided by the film layer 62 and especially its hydrodynamic lifting The lifting force reduces the power required to perform the cutting. seems to be well known In other words, the power required to perform the cutting is the same as that required to shear the chip from the workpiece. Apply not only the required force, but also along the insert and away from the cutting area. Includes the force required to push the chip away. The method and apparatus according to the invention Significantly reduces the force required to remove 2. Because above insert 18 This is because the friction between the surface 17 and the chip 42 is significantly reduced.

As mentioned above, several design concepts of the tool holder 10 according to the present invention The speed and feed dots in a particular application, the type of material being machined, the horsepower and Depends on a variety of variables, including cost and other factors. An example is given below and how to design a suitable tool holder 10 for the intended application. indicates whether these factors are taken into account.

In this example, the diameter is 61 cm (2 feet) and the shear strength is 35.15. h/m” (50,0OOpsi) cylinder made of SAF’10208g material 0.25 per revolution. m (0.011 re (IP R) per revolution ), the surface speed is 152 m/s (surface speed is 500 feet/s) (SFM )) and a cutting depth of 5.08 m (0,200 in). Assume that is desired.

The first step in the design process is determining the horsepower needed to make the cut. That's true.

HP = VmrHP, t (1) ut Here, 1-IP,,,t=16.4 cm3 (1 cubic inch) of SAE1020 steel material ) Horsepower required for machining ■, = Volume of cutting metal Machined edition published by Metcut Research Institute, Cincinnati, Ohio According to the data book (16.4 cm (1 cubic meter) of SAE1020m material n) The horsepower HPunit required for mechanical harrowing is 16.46m3 (1 cubic meter) The method is IHP per in). Metal body to be removed from workpiece 127) with each rotation To determine the product ■□, the following relation is used: V=DFS (2) r Here, D = Cutting depth 5.08 m (0,200 in)) F - Feed amount (1 time 0.25an) (0,010IPR) S-Speed (Surface 15271’L/sec) (500 feet SFM) In equation (2), the determined value of Vmr and “’ Mechanical Force Raw Data Handbook Solving Equation (1) by substituting the value of day Pun1t from Ku'', we get: HPo, 1 = 12HP Ensure that sufficient velocity is imparted to the refrigerant jet 38 exiting the release orifice 32. The horsepower of the Jet 38 is greater than the horsepower needed to cut the material. It has been determined empirically that it must be thick. To give a safety factor, The horsepower of the refrigerant 38 at the release orifice 32 is selected to be 14 l-IP.

Orifice cross-sectional area The horsepower of the refrigerant jet 38 at the release orifice 32 is approximately 141-IP. By determining, the cross-sectional area of the release orifice can be determined. First, below The pump flow rate Q, is determined using the following relationship: where 1-(P, .1 = Jet horsepower (14 HP) P - Pump pressure (psi) M.E. mp = mechanical efficiency of pump 30 At this point, the pressure provided by pump 30 is assumed. 1.05 to 9 Pumps of the order of 1500 psi (1500 psi) are adequate for many applications. It has been found that there is, and this is used as an example. Furthermore, the pump 30 is assumed to have a mechanical efficiency distribution of approximately 85%. Solving equation (3), the result is as follows That's right: Q = 51.48j! /min (13,6 gal/min) release orifice Area A of 32. In order to determine Assuming that it is possible, the equations related to the flow IQ of the pump 30 and the pressure P of the pump are Led: Formula (4) using the values of Q and P found as the above results: %formula%) As mentioned above, the width of the release orifice 32 is determined by the width of the cut being machined into the workpiece 12. Preferably, the depth is approximately equal to the depth. The cutting depth here is 5.08 m (0,200 The width of the orifice 32 is approximately 5.08 m (0,20 in). 0 in), and the distortion improvement value is approximately 1.17# (0,046 in). rice cake Of course, this solution assumes a rectangular orifice. The length of one axis is close to the depth of cut. If they are approximately equal and the total area is 0.059 cm2 (0,0092 square inches), then It should be understood that other cross-sectional shapes of orifices can be used.

refrigerant conduit The flow rate of pump 30 is 51.48j! / minute (13.6 gallons/minute), The cross-sectional area of the refrigerant conduit 28 can be calculated from the following relation: Here, A + - cross-sectional area of refrigerant conduit 28 V - velocity in refrigerant conduit 28 ρ = density of standard water-oil refrigerant As mentioned above, to reduce turbulence and resistance within conduit 28, cooling is conducted therethrough. The speed of the medium must be in the range of approximately 6 to 12.2 meters per second (20 to 40 fps). No. For the purposes of this example, the speed VC1 is 9.17T+-/5 (30fl S) is assumed here. Solving equation (5): A = 0.94 cm2 (0,1 45 square in) The standard dimensions of the conduit 28 are 12 with a slightly larger cross-sectional area to accommodate the standard dimensions. ．． 7m (1/2in) was selected.

The material type, speed and feed rate, and depth of cut selected in the example above are typical It provides practical application examples. Any known cutting insert and tool holders that allow the use of swing cooling devices that are capable of running at such speeds. Ru. The advantages of the method and apparatus according to the invention over such apparatus are strongly This means that productivity can be increased. If the speed and feed rate shown in the example When operating the holder 10, compared to known tool holders and insert designs, The life of the cutting insert can be extended by 2 to 5 times and the required horsepower can be reduced. It has been found that This is due to the friction reduction and Due to heat removal, the horsepower required to perform the cut calculated above is actually 14 horsepower. It means that the following is good. Therefore, reducing horsepower requirements and extending service life. In addition, by using the present invention, the horsepower used in machine tools can be reduced from that required for cutting. Productivity is improved by matching the amount of horsepower.

This is done by setting up the device as described above and achieving the selected speed (152 m/s (5 First operate at 00sfm)), pay attention to the horsepower used, and check the rate horsepower of the machine tool. This is done by increasing the cutting speed until the cutting speed is reached. In this way, more than the capacity of the machine can be used, greatly increasing productivity. Insert life increases due to increased speed However, the amount of material removed increases considerably.

Although the invention has been described with reference to preferred embodiments, it will be apparent to those skilled in the art that the invention may depart from the scope of the invention. It is possible to make various changes without changing the design, and this element can be substituted with an equivalent element. It will be understood that Furthermore, deviation from the essential scope of the invention5 Many changes may be made to adapt specific configurations and materials to the teachings of this invention without I can do it. Therefore, the above-mentioned method is considered to be the best mode for carrying out the present invention. It is not intended that the invention be limited to particular embodiments, and the invention resides in the claims appended hereto. It is intended to include all embodiments falling within the scope.

Figure 3 Porridge 3o diagram Figure 3b Figure 30

Claims (1)

[Claims] 1 A cutter with a surface terminating in a cutting edge and attached to a holder A method for machining a workpiece using a cutting insert, the method comprising: the front to form a chip so as to overlap the surface of the cutting insert; engaging the workpiece with the cutting edge; and the surface of the cutting insert and the tip from a position below the tip; supplying refrigerant at high speed between A machining method that includes stages. 2. at least one release orifice having a surface terminating in a cutting edge; The cutting insert is attached to the holder in which the A method of machining a workpiece, the method comprising: the front so that the release orifice is located on the face of the cutting insert; positioning the cutting insert within the retainer; on the face of the cutting insert and the release orifice of the retainer; The workpiece is placed on the cutting edge to form chips in an overlapping manner. engage, and the release orifice between the face of the cutting insert and the tip; A jet of refrigerant is injected at high speed from A machining method that includes stages. 3 at least one release orifice having a surface terminating in a cutting edge; The workpiece is machined by a cutting insert attached to a holder formed with A method of machining a material, the method comprising: overlapping the face of the cutting insert and the release orifice; engaging the workpiece with the cutting edge to form a chip; the engagement with the workpiece and the formation of the chip generates substantial heat; the release orifice between the face of the cutting insert and the underside of the tip; A refrigerant is injected at high speed from the fiss, and the refrigerant is confined within the gap formed by the sert, tip and retainer; A machining method that includes stages. 4. The engagement between the cutting insert and the workpiece, and the tip The heat generated by the formation of transmit to the medium, 4. The method of claim 3 further comprising the step. 5. Formed by the workpiece, cutting insert, tip and holder the coolant below the chip by confining the coolant within the gap where pressurize the medium, and The pressure applied by the refrigerant below the tip causes the workpiece to move forward. 4. The method of claim 3, further comprising the step of breaking an end of the chip. . 6. At least a portion of the refrigerant along the surface of the cutting insert and the tip is in contact with the surface of the cutting insert. generating hydrodynamic fluid support with the refrigerant to avoid contact; 4. The method of claim 3 further comprising the step. 7. Within at least 0.1 seconds by injecting the refrigerant to the bottom of the chip cooling the chip to near the atmospheric temperature of the refrigerant; and The chip is cooled by rapid cooling so that the molecules of the depth solidify in a fractured state. 4. The method of claim 3, further comprising the step of rendering the material brittle. 8 at least one release orifice having a surface terminating in a cutting edge; A cutting insert attached to a holder formed with a predetermined A method for machining a workpiece with a predetermined feed rate, the cutting edge being and the release orifice is located at a distance in the range of about 6 to 10 times the feed amount. position the cutting insert on the workpiece, and the tip so as to overlap the surface of the insert and the release orifice of the retainer. engaging the workpiece with the cutting edge to form a from the release orifice to the surface of the cutting insert and the tip. A jet of refrigerant is injected at high speed between A machining method that includes stages. 9 At least one release orifice having a surface terminating in a cutting edge The workpiece is machined by a cutting insert attached to a holder formed with A method for breaking chips formed in machining a material, the method comprising: overlapping the face of the cutting insert and the release orifice; engaging the workpiece with the cutting edge to form a chip; the engagement with the workpiece and the formation of the chip generates substantial heat; the release orifice between the face of the cutting insert and the underside of the tip; A refrigerant is injected at high speed from the fiss, and the refrigerant is confined within the gap formed by the sert, tip and retainer; evaporating at least a portion of the refrigerant within the gap by the substantial heat; The confinement of the coolant in the gap causes the coolant and The evaporated refrigerant is pressurized, and of the pressure exerted by the refrigerant and evaporated refrigerant under the chip; breaking the tip end portion from the workpiece by Chip breaking method including steps. 10, at least one release orifice having a surface terminating in a cutting edge; The cutting insert is fitted with a holder in which a Hydrodynamic fluid support on the underside of the chip formed when machining the workpiece. A method of forming a cutting insert, wherein the surface of the cutting insert and the release hole are the cutting of the workpiece to form a chip so as to overlap the rifice; Engage the surface of the cutting insert with the lower surface of the tip. injecting refrigerant from the release orifice at high velocity between to form a thin film of refrigerant along said surface of said cutting insert; directing at least a portion of the refrigerant along the surface to In order to prevent the tip from coming into contact with the surface of the cutting insert. In order to provide hydrodynamic fluid support by the thin coolant film on the underside of the chip Form, A method of forming a fluid support comprising steps. 11 A device for machining a workpiece, comprising at least one release orifice. a retainer having a fin and a cutting having a surface terminating in a cutting edge; a cutting insert that engages with the workpiece and inserts the cutting insert into the cutting insert; adapted to form a tip overlapping said surface and said release orifice. cutting insert, the release along the face of the cutting insert and on the underside of the tip; means for injecting refrigerant at high velocity from the orifice; The machining equipment consists of: 12 The cutting edge machine the workpiece at a predetermined feed rate. , the cutting insert has the release orifice at the cutting edge. The release orifice is positioned at a distance of about 6 to 10 times the feed amount. 12. The machining device of claim 11, wherein the machining device is mounted within a holder. 13. The cutting edge is used to machine the workpiece to a predetermined cutting depth. and the release orifice has a diameter approximately equal to the cutting depth. A machining device according to claim 11, comprising: 14 The cutting edge machine the workpiece material at a predetermined feed rate. and said release orifice is non-circular having a dimension along a major axis and a dimension along a minor axis. 12. A cross section, the dimension along the long axis being approximately equal to the cutting depth. Machining equipment. 15. A predetermined horsepower is required to form the tip, and the release orinois said means for injecting refrigerant at high velocity from The refrigerant is configured to provide a horsepower larger than the predetermined horsepower. A machining device according to claim 11. 16. A retainer having at least one release orifice; a cutting insert having a surface terminating in a cutting edge, the cutting insert having a surface terminating in a cutting edge; said face of the cutting insert and said release holder. to be engaged with the workpiece to form a chip overlapping the rifice. the cutting insert, which is means for sending refrigerant to the holder; The refrigerant is pumped through the retainer and out of the release orifice at a high velocity into the cup. injecting the coolant onto the underside of the chip along the surface of the tipping insert; and means for A machining device consisting of: 17, the means for delivering refrigerant to the retainer includes a pump and a conduit; and conduits transport the refrigerant to the retainer at a rate of 20 to 40 feet/second. 17. The machining device according to claim 16, wherein the machining device is adapted to feed at a speed range of . 18. said means for directing said refrigerant through said retainer to said release orifice; includes a main passageway and an intermediate passageway disposed between the main passageway and the release orifice. The machining device according to claim 16. 19 The main passage may have a larger diameter than any part of the intermediate passage. Machining equipment according to item 18 of the scope of demand. 20 said intermediate passage has a constant taper from said main passage to said release orifice; 19. The machining device according to claim 18, wherein the machining device is formed of a shaped wall surface. 21. The machining apparatus according to claim 18, wherein the intermediate passage has a frustoconical shape. 22. Claim 18, wherein the intermediate passage is formed of a highly polished wall surface. Section machining equipment. 23. The intermediate passage still has a constant taper from the former main passage to the release orifice. formed by a shaped wall, the wall forming at the release orifice; 19. The machining apparatus of claim 18, wherein the angle at which the angle is approximately 20 degrees. 24, the release orifice has a circular cross section, and the release orifice and the main passageway wherein said intermediate passageway between said release orifice is about 20 times the diameter of said release orifice. Machining equipment of paragraph 18. 25 The release orifice has a non-circular cross section, and the release orifice and the main passage said intermediate passageway between said passageways has the same cross-sectional area as said release orifice of said non-circular cross-section; 19. The machine of claim 18, wherein the machine has a circular cross section of approximately 20 times the diameter of the orifice. Processing equipment. 26. a retainer having at least one release orifice; a cutting insert installed in the holder, the cutting insert a surface terminating in one joint, the surface of the cutting insert and the annular is engaged with the workpiece to form a tip overlapping the emitting orifice. The engagement with the workpiece and the formation of the chip are performed using a high temperature vapor barrier. the cutting insert is adapted to form a a substantially closed chamber having a wall surrounding said release orifice by contacting said opening; a gap is formed, and the wall surface of the gap is connected to the tip and the cutting insert. provided by the surface, the holder, and the workpiece; injecting coolant from the release orifice at a high velocity onto the underside of the chip within the gap; means for refrigerant, the refrigerant comprising: by penetrating the vapor barrier and engaging the workpiece and forming the chip. removing said heat generated; the surface of the cutting insert so that the surface and the tip do not come into contact with each other; create a hydrodynamic fluid support along the within the gap to evaporate and separate the chip from the workpiece. creating pressure on the underside of the chip; The means configured to: Machining equipment that has. 1