JP4896055B2 - Forced cooling system for electrodeposition tools - Google Patents

Description

  The present invention relates to a forced cooling system for an electrodeposition tool that is effective for increasing productivity when grinding difficult-to-cut materials.

Recently, there is an increasing demand for grinding difficult-to-cut materials such as cemented carbide (hard metal) as a mold material and titanium alloy and nickel alloy as aircraft-related materials. The reason why these materials are difficult to cut is that when the carbide is a workpiece, it is very hard and only a diamond or cubic boron nitride (CBN) tool can be used. However, when the productivity is increased, the tool temperature rises and the original strength and hardness of diamond and CBN cannot be maintained. In addition, when the titanium alloy or nickel alloy is a workpiece, its own thermal conductivity is very low, and much of the heat generated in the grinding process flows into the tool. This is because the original strength and hardness cannot be maintained. On the other hand, NC controlled processing using an electrodeposition tool with diamond or CBN as abrasive grains is considered advantageous from the viewpoint of processing time and processing cost, and this processing is frequently required as a field work. In order to solve the problem of increasing the tool temperature, as described in Patent Document 1 and the like, a heat pipe is incorporated in the main body of the grinding tool along the axial direction, and the heat radiation area of the heat pipe is cooled. A cooling system for a tool provided with a cooling means has been considered.
JP 2005-40925 A

  The cooling system using a tool with a built-in heat pipe not only has a lower cooling efficiency than the direct cooling method in which a heat is exchanged by directly contacting a coolant to the tool body, but also avoids a significant cost increase of the tool itself. Therefore, a practical effect cannot be expected. Of course, it is also possible to adopt a cooling method in which the cooling oil is directly dropped into contact with the outer surface of the tool, as in the conventional wet grinding method, which can be said to be a direct cooling method. Although it is possible, the machining action part at the tip of the tool, which is the part to be cooled of the tool, is hidden by the workpiece during machining, and the cooling oil is not applied to the machining action part at the tool tip. Also, even if the cooling oil can be applied to the tool rotating at high speed, the cooling oil is scattered by the centrifugal force on the surface of the tool because the tool is rotating at high speed, and the dropped cooling oil is applied. Most of them do not reach the working part at the tool tip. That is, in the conventional wet grinding method, the expected cooling effect can hardly be expected.

An object of the present invention is to provide a forced cooling system for an electrodeposition tool that can solve the conventional problems as described above, and the forced cooling system for an electrodeposition tool according to claim 1, When a reference numeral of an embodiment to be described later is attached and indicated, an axial cavity 8 is provided in the body 5 of the electrodeposition tool 4 so that the attachment end 5b side of the body 5 is opened. In the state where the mounting end portion 5b is mounted on the tool drive spindle 1 of the machine tool, a refrigerant supply means for supplying a refrigerant to the back end portion 8a of the cavity portion 8 is provided, and the back end portion 8a of the cavity portion 8 is provided. When the refrigerant after heat exchange is discharged into the atmosphere outside the tool via the cavity 8, the refrigerant supply means is configured by a refrigerant supply pipe 9 inserted into the cavity 8. The water as the refrigerant is supplied from the refrigerant supply pipe 9 to the back end portion of the cavity 8. Was fed at a degree of flow rate substantially total volume a is vaporized by heat exchange via an air gap between the vapor cavity 8 and the refrigerant supply tube 9 configured to discharge into the atmosphere outside the tool, The electrodeposition tool 4 includes the tool body 5 having the cavity 8 formed from a material having high thermal conductivity such as copper, copper alloy, aluminum, aluminum alloy, and the cavity 8. Abrasive grains 6 are electrodeposited on the surface of the tool body 5 with a plating material (plating layer 7) having a high thermal conductivity such as copper, copper alloy, aluminum, aluminum alloy or the like .

Further, the forced cooling system for an electrodeposition tool according to claim 2 is provided with an axial cavity 8 in the body 5 of the electrodeposition tool 4 in which the side of the mounting end 5b of the body 5 is opened. In a state where the mounting end portion 5b of the tool body 5 is mounted on the tool drive spindle 1 of the machine tool, a refrigerant supply means for supplying a refrigerant to the back end portion 8a of the cavity portion 8 is provided. In discharging the refrigerant after heat exchange from the end portion 8a to the atmosphere outside the tool through the cavity portion 8, the attachment end portion 5b of the tool body 5 of the electrodeposition tool 4 is a work piece. The coolant supply means is attached to the lower end of the tool drive main shaft 1 in the vertical direction of the machine, and the refrigerant supply means supplies the refrigerant into the cavity portion 8 from the upper end open portion (open end 8b) of the cavity portion 8 in the vertical direction. The water dripping nozzle 11 for dripping water as the water dripping nozzle 11 Water is dripped and supplied at a flow rate such that substantially the entire amount is vaporized by heat exchange at the back end portion 8a of the cavity portion 8, and steam is discharged to the atmosphere outside the tool via the cavity portion 8. In the electrodeposition tool 4, the tool body 5 having the cavity 8 is formed from a material having high thermal conductivity such as copper, copper alloy, aluminum, aluminum alloy, and the cavity 8 Abrasive grains 6 are electrodeposited on the surface of the tool body 5 provided with a plating material (plating layer 7) having a high thermal conductivity such as copper, copper alloy, aluminum or aluminum alloy .

  According to the forced cooling system for an electrodeposition tool according to the first aspect of the present invention, the main body tip of the electrodeposition tool mounted on the tool drive spindle of the machine tool, that is, the machining operation portion of the electrodeposition tool is provided. When grinding a workpiece, the coolant is supplied by the coolant supply means to the inner end of the working portion of the electrodeposition tool, that is, the inner end of the cavity portion provided in the tool body. Since the heat exchange action is performed with the processing action part, and the refrigerant after the heat exchange is discharged outside the tool through the cavity part, the liquid phase or the gas phase is caused by gravity or a feeding pressure. As long as an appropriate refrigerant is supplied to the back end of the cavity, the heat generated at the machining operation portion of the electrodeposition tool is reliably propagated and absorbed by the refrigerant, and the refrigerant is exchanged outside the tool after heat exchange. By discharging, the heat generated in the working part of the electrodeposition tool can be reliably removed. .

  That is, as compared with a conventional cooling system using a tool with a built-in heat pipe, the working portion of the electrodeposition tool can be forcibly cooled directly from the inside by the refrigerant, and the cooling efficiency is remarkably increased. In addition, it is possible to cool the working portion of the electrodeposition tool extremely reliably and efficiently as compared with the case of relying on the wet grinding method in which the cooling oil is applied to the outside of the tool. Therefore, it is difficult to maintain the original strength and hardness of abrasive grains such as diamond and CBN due to an increase in tool temperature when grinding difficult-to-cut materials as described above with an electrodeposition tool. By eliminating the problems and grinding difficult-to-cut materials such as cemented carbide (hard metal), titanium alloy, nickel alloy using the electrodeposition tool of the system of the present invention, the processing time can be reduced and the processing cost can be reduced. As a result, it has become possible to expect a significant extension of the service life of the electrodeposition tool. Moreover, according to the present invention, a cooling system that uses a tool with a built-in heat pipe is used on the electrodeposition tool side, as long as the hollow portion opened on the free end side of the tool body is formed in the axial direction of the tool body. As is the case, there is no significant increase in cost of the electrodeposition tool itself.

  In addition, according to the present invention, not only can the present invention be carried out at a very low cost using water, but the high-temperature water after heat exchange is not recovered from within the tool body, Since the entire amount is vaporized and discharged at the back end of the cavity, the amount of water to be supplied is set to the maximum amount that can be vaporized at the back end of the cavity. An extremely high forced cooling effect can be obtained by exerting the maximum cooling effect.

  According to the second aspect of the present invention, the same effect as that of the first aspect of the invention can be expected, and the cavity formed in the tool body is dropped from above toward the cavity. The inner diameter is such that the water droplets can reach the back end (lower end) of the cavity, the refrigerant supply pipe inserted into the cavity of the tool body is eliminated, and the system configuration is simplified. Can be implemented at a lower cost. Of course, in the configuration of the second aspect, the main body free end side of the electrodeposition tool is attached to the lower end of the tool drive main shaft in the vertical direction of the machine tool, and the hollow portion is in the vertical direction with the upper end open. However, in the configuration using the refrigerant supply pipe inserted into the hollow portion as in claim 1, the present invention is also applicable to a machine tool in which the electrodeposition tool is set horizontally and horizontally. The invention can be applied.

  In addition, in conventional electrodeposition tools, the diamond and CBN abrasive grains have extremely good thermal conductivity and excellent heat sink characteristics, but there are two materials: stainless steel for the tool body and nickel for electrodeposition. As a result, the cooling characteristics of the electrodeposition tool were significantly impaired. However, according to the first or second aspect of the present invention, copper, copper alloy, aluminum, aluminum alloy having higher thermal conductivity than stainless steel or nickel can be used for the material of the tool body or the electrodeposition material. Therefore, it is possible to improve the heat sink characteristics of the electrodeposition tool itself, dissipate the heat generated by the grinding process efficiently, and reliably prevent the processing action part at the tip of the tool from becoming high temperature.

Compared to stainless steel and nickel, materials with high thermal conductivity such as copper are basically low in mechanical strength. However, the problem is that the tool is made of these materials during actual grinding. Whether the main body and the electrodeposition layer reach the yield stress. In this regard, as will be described later, it has been confirmed that there is no problem in light of the practical cutting depth during actual grinding.
That is, according to the electrodeposition tool 4 according to the first or second aspect of the present invention, the tool body 5 having the cavity 8 is made of stainless steel such as copper, copper alloy, aluminum, and aluminum alloy. Compared to nickel, copper, copper alloy, aluminum, which has a higher thermal conductivity than nickel, is manufactured by using a material having a higher thermal conductivity and electrodepositing abrasive grains 6 on the tool body 5. Since an aluminum alloy or the like is used, the heat generated during grinding by the working portion 5a of the tool body 5 is transferred from the plating layer 7 having a high thermal conductivity to the body 5 and from the body 5 having a high thermal conductivity to the cavity. It is possible to effectively prevent the processing action part 5a from becoming high temperature because it is transmitted to the water in contact with the inner wall surface of the part 8 very efficiently and radiated.
As described above, according to the electrodeposition tool 4 employed in the system according to the present invention, the tool body 5 having the cavity 8 and the plating layer 7 are made of a material having high thermal conductivity such as copper. Therefore, compared with the conventional system, it is possible to obtain an extremely large cooling capacity for the electrodeposition tool. When grinding hard materials such as carbide, titanium alloy, nickel alloy, etc. However, since the tool can be maintained at a low temperature, the tool life can be greatly extended and the productivity can be improved.

  A specific example of the present invention will be described below with reference to the accompanying drawings. In FIG. 1 showing a first embodiment of the present invention, reference numeral 1 denotes a tool drive spindle in a vertical direction of a machine tool. As is well known in the art, a spindle 3 having a collet chuck 2 at its tip is concentrically attached to the tool driving spindle 1 at the lower end of the spindle 1, and an electrodeposition tool 4 is attached to the lower end of the spindle 3 by the collet chuck 2. Mounted concentrically. As shown in FIGS. 3 and 4, for example, the electrodeposition tool 4 forms one end of a columnar body 5 having an outer diameter of about 6 mm into a projecting curved surface, and from the tip of the projecting curved surface. An abrasive 6 made of diamond or CBN is electrodeposited on the entire outer peripheral surface of an axially required region (for example, about 15 mm) by a plating layer 7 to form a working portion 5a. The hollow portion 8 (about mm) is drilled concentrically from the end face of the mounting end portion 5b of the main body 5 so that the back end portion 8a is located inside the processing action portion 5a. Therefore, the cavity portion 8 has an open end 8 b on the attachment end portion 5 b side of the main body 5.

  The electrodeposition tool 4 having the above-described configuration is concentrically attached to the lower end portion of the spindle 3 by the collet chuck 2 at the attachment side end portion 5 b of the main body 5. A through hole 3b communicating with the tool mounting hole 3a is concentrically provided at the inner end of the spindle 3, and the upper end of the spindle mounting hole 1a of the tool driving spindle 1 is also opened. Accordingly, in the cavity portion 8 of the electrodeposition tool 4 attached to the spindle 3 from the upper end opening portion of the spindle attachment hole 1a in the tool drive spindle 1 through the through hole portion 3b and the tool attachment hole 3a of the spindle 3. In addition, a linear refrigerant supply pipe 9 made of, for example, stainless steel having a small diameter (for example, about 2 mm in diameter) and a large bending rigidity, which is appropriately smaller than the inner diameter of the hollow portion 8, can be inserted. Thus, if the coolant supply pipe 9 is inserted into the cavity portion 8 of the electrodeposition tool 4 so that the tip thereof reaches the vicinity of the back end portion 8a of the cavity portion 8, the coolant supply tube 9 is preferably hollow. For example, the refrigerant supply pipe 9 is fixed to a frame of a machine tool supporting the tool driving spindle 1 via an appropriate support so as not to contact the inner wall surface of the portion 8, and the refrigerant supply pipe 9 is connected to the flow rate of the flow rate. Connected to a fine-tunable mist device 10.

  Grinding work on the workpiece by the electrodeposition tool 4 is performed by a conventionally known method. In this grinding work, when water as a coolant is continuously supplied from the mist device 10 to the coolant supply pipe 9 at an appropriate flow rate. The water flowing out from the tip of the refrigerant supply pipe 9 is supplied into the inner end 8a of the cavity 8 of the tool body 5, and the heat of the working part 5a generated by the grinding action from the peripheral wall of the cavity 8 is provided. Is directly heated and vaporized, and the peripheral wall of the back end portion 8a of the cavity portion 8, that is, the working portion 5a is directly cooled by the cooling action by the heat of vaporization. Vapor generated by the vaporization of water rises through a gap between the refrigerant supply pipe 9 and the inner wall surface of the cavity 5, and passes through the tool mounting hole 3 a and the through hole 3 b of the spindle 3 in the tool drive spindle 1. Through the spindle mounting hole 1a, it is spontaneously discharged from the open end of the upper end to the outside. Accordingly, the flow rate of water continuously supplied from the mist device 10 to the refrigerant supply pipe 9 is vaporized in the back end portion 8a of the cavity portion 8 in the back end portion 8a of the cavity portion 8 so that the liquid flow is reduced. By setting the maximum flow rate that does not remain in the phase, the vaporization heat cooling effect of water from the inside with respect to the machining action portion 5a of the tool body 5 is maximized, and the machining action portion 5a of the tool body 5 is cooled extremely efficiently. Can do.

  In the second embodiment of the present invention shown in FIG. 2, the coolant supply pipe 9 connected to the mist device 10 is not inserted into the cavity 8 of the tool body 5, and the water dropping nozzle 11 is formed at the tip of the coolant supply pipe 9. The water dropping nozzle 11 is positioned and held so that the water dripping from the water dropping nozzle 11 flows into the cavity 8 of the tool body 5 from the open end 8b at the upper end. In the illustrated example, the water dripping nozzle 11 is positioned in the tool mounting hole 3 a of the spindle 3, but the water dripping is performed in the spindle mounting hole 1 a of the tool driving main shaft 1 or above the spindle mounting hole 1 a of the tool driving main shaft 1. A nozzle 11 is arranged so that water dripping from the water dripping nozzle 11 flows into the cavity 8 of the tool body 5 from the through hole 3b of the spindle 3 via the tool mounting hole 3a. Also good. The positioning and fixing of the water dripping nozzle 11 is performed when the water dripping nozzle 11 can be directly held by the support attached to the frame of the machine tool, and when the water dripping nozzle 11 cannot be directly held as shown in the structure, The water supply nozzle 9 may be positioned by holding the coolant supply pipe 9 with the support.

  The cooling system for an electrodeposition tool according to the present invention can be implemented as described above. More preferably, the tool body 5 having the cavity 8 is made of copper, copper alloy, aluminum, aluminum alloy, or the like. The plating layer 7 is made of a material having a high thermal conductivity compared to stainless steel, and electrodeposits the abrasive grains 6 on the tool body 5. The copper or copper alloy has a higher thermal conductivity than nickel. Aluminum, aluminum alloy, etc. are used. According to the electrodeposition tool 4 configured by specifying the material in this way, the heat generated along with the grinding by the working portion 5a of the tool body 5 is transferred from the plating layer 7 having a high thermal conductivity to the body 5. And, it is possible to effectively suppress heat from being transferred from the main body 5 having high thermal conductivity to the water in contact with the inner wall surface of the cavity portion 8 and dissipated, and the processing portion 5a can be effectively prevented from becoming high temperature.

  FIG. 5 shows the influence on strength when a grinding experiment is attempted in one embodiment of the system of the present invention. That is, when the electrodeposition tool 4 constituted by using copper for the tool body 5 and the plating layer 7 is adopted in the system of the present invention shown in FIG. mm) and the relationship between the maximum stress (MPa) in the tool body 5 and the plating layer 7 are analyzed by a finite element method simulation. As is apparent from this figure, the yield stress of the copper constituting the tool body 5 and the plating layer 7 is 86.3 MPa, but the yield stress is not reached until the cutting depth is 0.3 mm (300 μm). In other words, since the practical depth of cut is about 5 μm, there is no problem in terms of strength even when copper having lower mechanical strength than stainless steel is used for the tool body 5 and the plating layer 7. Obviously not.

FIG. 6 shows the tool life when the carbide V10 is ground under the same machining conditions shown in the figure, that is, the total grinding amount (mm ³ ) which is the total amount removed from the base material by grinding. The comparison results are shown. In the figure, A is used for grinding an electrodeposition tool consisting of a conventional solid tool body in which the cavity 8 is not provided in the tool body in an environment that does not use any cooling system. B shows the total amount of grinding in the case of being provided, and B, as described in Patent Document 1, incorporates a heat pipe in the tool body and is provided with a cooling means for cooling the heat radiation area of the heat pipe. 1 shows the total amount of grinding when the cooling system is used, and C employs the electrodeposition tool 4 configured by using copper for the tool body 5 and the plating layer 7 in the system of the present invention shown in FIG. The total amount of grinding is shown. As is apparent from FIG. 6, the electrodeposition tool 4 constructed by using a material having high thermal conductivity such as copper for the tool body 5 and the plating layer 7 as described above is adopted in the system of the present invention. Compared with the conventional system as described above, it can obtain extremely large cooling capacity for electrodeposition tools, and severe processing conditions when grinding difficult-to-cut materials such as carbide, titanium alloy, nickel alloy, etc. However, since the tool can be maintained at a low temperature, the tool life can be greatly extended and the productivity can be improved.

It is a vertical side view of the principal part which shows 1st embodiment of this invention. It is a vertical side view of the principal part which shows 2nd embodiment of this invention. It is a vertical side view of an electrodeposition tool. It is an enlarged view of the A section of FIG. It is a graph which shows the experimental data regarding the mechanical strength of the electrodeposition tool which concerns on one Embodiment of this invention. It is a graph which shows the experimental data regarding the tool life in the conventional system and the system which concerns on one Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Tool drive spindle 1a Tool drive spindle spindle mounting hole 2 Collet chuck 3 Spindle 3a Spindle tool mounting hole 3b Spindle through hole 4 Electrodeposition tool 5 Tool body 5a Tool body working portion 5b Tool body mounting end Part 6 Abrasive Grain 7 Abrasive Electroplating Plating Layer 8 Tool Body Cavity 8a Cavity Deep End 8b Cavity Open End 9 Refrigerant Supply Pipe 10 Mist Device 11 Water Dropping Nozzle

Claims (2)

In the main body of the electrodeposition tool, a hollow portion in the axial direction that opens at the end of the tool body for attachment is provided, and in the state where the attachment end of the tool body is attached to the tool drive spindle of the machine tool, Provided with a refrigerant supply means for supplying a refrigerant to the back end of the cavity, and when discharging the refrigerant after heat exchange from the back end of the cavity through the cavity to the atmosphere outside the tool ,
The refrigerant supply means is composed of a refrigerant supply pipe inserted into the cavity, and the flow rate is such that substantially the entire amount of water as a refrigerant is vaporized by heat exchange at the back end of the cavity from the refrigerant supply pipe. Configured to supply and discharge steam into the atmosphere outside the tool via a gap between the cavity and the refrigerant supply pipe,
In the electrodeposition tool, the tool body including the cavity is formed from a material having high thermal conductivity such as copper, copper alloy, aluminum, aluminum alloy, and the surface of the tool body including the cavity. This is a forced cooling system for electrodeposition tools, in which the abrasive grains are electrodeposited with a plating material having high thermal conductivity such as copper, copper alloy, aluminum, aluminum alloy . In the main body of the electrodeposition tool, a hollow portion in the axial direction that opens at the end of the tool body for attachment is provided, and in the state where the attachment end of the tool body is attached to the tool drive spindle of the machine tool, Provided with a refrigerant supply means for supplying a refrigerant to the back end of the cavity, and when discharging the refrigerant after heat exchange from the back end of the cavity through the cavity to the atmosphere outside the tool ,
The electrodeposition tool has an attachment end of a tool body attached to a lower end of a vertical tool driving spindle of a machine tool, and the coolant supply means opens the upper end of the vertical cavity. A water dropping nozzle that drops water as a refrigerant into the cavity from the water supply portion, and supplies water from the water dropping nozzle dropwise at a flow rate such that substantially the entire amount is vaporized by heat exchange at the back end of the cavity. The steam is configured to be discharged into the atmosphere outside the tool via the cavity,
In the electrodeposition tool, the tool body including the cavity is formed from a material having high thermal conductivity such as copper, copper alloy, aluminum, aluminum alloy, and the surface of the tool body including the cavity. This is a forced cooling system for electrodeposition tools, in which the abrasive grains are electrodeposited with a plating material having high thermal conductivity such as copper, copper alloy, aluminum, aluminum alloy .

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