JP2003094285A - Semi-dry processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semi-dry processing system in which mist pressure is secured irrelevant to kinds of cutting tools and stable mist is discharged. SOLUTION: The semi-dry processing system 10 is provided with a mist generating device 30 to generate mist 35 by pressure from a pressure source 39 and a semi-dry processing device 15 which leads the mist 35 generated by the mist generating device 30 by oil holes 1a, 1b formed inside a drill 1 and discharge the mist 35 to a work 45 from the drill 1. In the system, mist grooves 4a, 4b, 5a, and 5b to lead the mist 35 to the surface of the drill 1 are formed to an inner diameter of a collect 5 to hold the drill 1 and/or on the surface of the drill 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semi-dry machining system, and more particularly to a semi-dry machining system for performing stable machining while discharging stable mist from a cutting tool onto a workpiece.

[0002]

2. Description of the Related Art Conventionally, at the time of cutting for machining,
In order to ensure the lubrication and cooling of the cutting edge of a cutting tool that performs processing and the ability to discharge chips to the outside, semi-dry processing is known in which processing is performed while supplying mist in which oil is atomized to the cutting edge. In this semi-dry processing, for example, in hole processing, a drill is used as a cutting tool. Generally, the smaller the drill diameter, the lower the drill rigidity.
With a small diameter drill of φ5 or less, machining cannot be performed at high feed.

Therefore, as described above, a mist passage (referred to as an oil hole) through which the mist passes is formed in the drill in order to ensure the lubrication, the cooling of the cutting edge and the discharge property of the chips. In this case, the diameter of the oil hole inevitably becomes smaller as the diameter of the drill becomes smaller, and the pressure of the mist discharged at the tip of the drill blade (mist pressure) becomes smaller. As described above, when the mist pressure becomes small, the discharge property of chips during processing may deteriorate, and the drill may break.

In order to solve this problem, an atomizing device for semi-dry processing, which always supplies a mist having an optimum particle size even if the cutting tool changes, is disclosed in, for example, JP-A-11-1383.
No. 86 publication. In the device shown in this publication, a main pressure reducing valve and an oil mist generating device (mist generating device) for generating a Venturi type mist are provided between the air supply path and the tool. Further, one electromagnetic valve is provided for the main oil supply passage and one electromagnetic valve for discharging mist in the main oil supply passage is provided. With this configuration, even if the hole diameter of the oil hole through which the mist formed inside the tool changes, the differential pressure between the output side pressure of the oil mist generator and the output side pressure can be controlled by controlling the two solenoid valves. To
The mist having an optimum particle size can be supplied by adjusting the mist to be constant to some extent.

Generally, when such a mist is generated, factory air is used as a supply source of mist pressure and an inexpensive pressure source in a factory. The pressure of the factory air (air pressure) is set to about 0.4 to 0.5 MPa. When machining the workpiece, if the pressure from the factory air is used as it is, the path from the position of the air supply source to the mist generated by the mist generator and the discharge to the workpiece A pressure drop occurs at. As a result, the discharged mist pressure becomes lower than 0.2 MPa. Due to this, cutting ability of the cutting chips is reduced and cutting chips are clogged between the cutting tool and the cutting tool and the workpiece, and when high-speed processing is performed due to this, there is a problem such as breakage of the cutting tool. It can happen.

Furthermore, when machining is performed using factory air, the factory air is often used in common, but the mist pressure may decrease during processing depending on the load conditions used at the same time. However, sufficient mist is not discharged, and the workability changes.

[0007]

In the venturi type mist generator used in the above publication, in order to constantly generate mist, the differential pressure between the inlet and the outlet of the mist generator is kept constant. There is a need. For this reason, in the device disclosed in the above-mentioned publication, two electromagnetic valves are controlled to switch the path through which the mist flows together with the air to maintain a constant differential pressure to some extent. The on / off control of the two solenoid valves allows only three-stage adjustment, and the mist pressure fluctuates stepwise depending on the operating state of the solenoid valves (see FIG. 4).

Therefore, the present invention has been made in view of the above problems, and a semi-dry machining system in which a mist pressure is ensured regardless of the type of cutting tool, and a semi-dry machining system in which a stable mist is discharged are provided. What to do
A technical issue is to provide a semi-dry processing system capable of maintaining a constant mist pressure.

[0009]

The technical means taken to solve the above-mentioned problems are as follows: a pressure source, a venturi-type mist generator for generating mist by the pressure from the pressure source, and the inside of a cutting tool. A first mist passage is formed in the semi-dry processing apparatus for guiding the mist generated by the mist generation device to the blade tip of the cutting tool by the first mist passage, and spraying the mist from the cutting tool onto a workpiece to be processed. And a second mist passage for guiding the mist to the surface of the cutting tool, the second mist passage being formed in the holding portion of the holding member that holds the cutting tool of the semi-dry processing apparatus and / or the surface of the cutting tool. That's what I did.

According to the above-mentioned means, the semi-dry processing apparatus has the first mist passage formed inside the cutting tool,
Since the second mist passage for guiding the mist from the surface of the cutting tool is formed on the holding portion of the holding member and / or the surface of the cutting tool of the semi-dry processing apparatus, the mist generated by the mist generating device is , The second mist passage other than the first mist passage guides the blade to the cutting tool, and is discharged from the cutting tool. For example, when the cross-sectional area in the direction perpendicular to the axial direction of the first mist passage is S1 and the cross-sectional area in the direction perpendicular to the axial direction of the second mist passage is S2, the cross-sectional area S3 through which the mist passes. Is the sum (S3 = S1 + S2). Therefore, even when the first mist passage of the cutting tool is narrow, it becomes possible to supply the mist from the second mist passage of the holding member that holds the cutting tool, regardless of the type of cutting tool.
It becomes possible to secure the mist pressure and the mist flow rate and make them constant. Particularly, it is possible to suppress the generation failure of mist due to the reduction of the differential pressure between the inlet and the outlet of the mist generating device, which occurs when a small-diameter blade is used.

In this case, if a pressure increasing device for increasing and storing the pressure of the pressure source is provided between the pressure source and the mist generating device, the increased pressure is temporarily stored and then the mist generating device. Can be supplied to. At this time, even if the pressure source fluctuates, the stored pressure is supplied to the mist generator, so that the pressure supplied to the mist generator does not fluctuate and a stable pressure is supplied to the mist generator. It becomes possible. This does not require expensive equipment such as compressors.

Further, since the pressure stored in the pressure booster is set higher than the pressure at which the mist generator produces mist having the smallest particle size, the pressure supplied to the mist generator is equal to the pressure supplied to the mist generator. There is room to create a constant differential pressure between the inlet and outlet.

In this case, by fixing the pressure of the mist to a predetermined pressure, the mist generator can generate the mist having the minimum particle size in a more stable state.

Further, since the pressure reducing device for reducing the pressure stored in the pressure increasing device to the pressure at which the mist generating device produces mist having the minimum particle size is provided between the pressure increasing device and the mist generating device, The decompression device secures a desired constant differential pressure at which the mist generation device produces the minimum particle size, and stable mist can be produced.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration diagram of a semi-dry processing system 10. The semi-dry processing system 10 according to the present embodiment is roughly classified into a pressure increasing device 20 that increases a pressure from an air pressure source (air source) 39 to a predetermined pressure and stores the pressure, and a pressure increasing and storing pressure that is a predetermined pressure. Pressure reducing device 25 for reducing the pressure to a pressure, mist generating device 30 for generating a mist by utilizing the Venturi effect based on the reduced pressure, and semi-dry processing for discharging mist 35 to work 45 fixed to work mounting jig 46 Device 1
5 and. In the present embodiment, the air source 39 is inexpensive factory air, but the pressure source 39 is not limited to this and may be any inexpensive pressure source.

In this semi-dry processing system 10, the pressure P0 from the air source 39 is first increased by the pressure increasing device 20. In this case, the filter 21 is provided in the middle of the air path supplied from the air source 39. Air is filter 2
The pressure gauge (for example, a pressure sensor) 11 is provided before the pressure is input to the pressure booster 22 though the pressure sensor 11 passes through the pressure booster 22.
The supply pressure P0 of the pressure source 39 is detected. On the other hand, the pressure P0 from the air source 39 is increased to a predetermined pressure by the pressure intensifier 22. Here, as an example, the factory air is set to 0.4
When the pressure is set to MPa, the pressure is increased to 0.8 MPa which is twice the pressure. Thereafter, the increased pressure is stored in the buffer tank 23 having the capacity B1. The buffer tank 23 is also provided with a pressure gauge (for example, a pressure sensor) 12 to detect the pressure P1 in the buffer tank.

A pressure reducing device 25 is provided after the pressure increasing device 20. The decompression device 25 decompresses the pressure stored in the buffer tank 23 through a filter 26, a decompression valve 27, and an electromagnetic valve 28 that can be electromagnetically switched between two states. The electromagnetic valve 28 is provided with an electric signal from the outside so that a path (air path) through which air in a non-communication state passes is in a communication state, and the decompression device 25.
The pressure reduced to the set pressure P6 is detected as the pressure P3. In the present embodiment, the pressure P1 stored in the buffer tank 23 is changed to the set pressure P6 = 0.
Reduce the pressure to 6 MPa.

After the decompressor 25, the mist generator 3
0 is allocated. In this case, the pressure reduced by the valve 27 and the electromagnetic valve 28 of the pressure reducing device 25 is supplied to the inlet 40 that is the inlet of the mist generating device 30, and this pressure P3
Is detected by a pressure gauge (for example, a pressure sensor) 13.
The mist generator 30 stores oil therein, and the oil 31 stored therein is converted into a mist 35 in the form of a mist to generate mist generator 3
It is a device that supplies the external conduit 16 from a discharge port 36 which is an outlet of 0. The mist 35 generated here supplies the air from the air source 39 to the inlet 40 via the air conduit 41. In this case, the oil 31 accumulated below is sucked up by the oil pipe 33 from the suction port 32 with a filter and sucked up, and the oil 3 is discharged from the venturi type discharge port 34 by the principle of spraying.
Atomized mist 35 is generated by atomizing and ejecting 1.

The mist 35 generated by the mist generator 30 is supplied from the outlet 36 through the rotary joint 17 and the external pipe 16 to the mist pipe 7 inside the semi-dry processing device 15, and the mist 35 of the semi-dry processing device 15 is supplied. Cutting edge of cutting tool 1 attached to the tip of spindle 6 and cutting tool 1
The mist 35 in the form of mist is discharged from the mist groove 4 (4a, 4b) to the surface of the cutting tool 1. In this state, the cutting tool 1 is brought into contact with the work 45 mounted on the work mounting jig 46 to perform the machining.

Next, with reference to FIG. 2 and FIG. 3, the shape and configuration of the spindle 6 rotating in the semi-dry machining device 15 and the cutting tool (for example, a drill for drilling holes) 1 attached to the spindle 6 will be described. To do.

Drill 1 as a processing tool for semi-dry processing
Has a plurality of (for example, two) oil holes 1a and 1b that extend in the axial direction in the axial direction in the axial direction in the axial direction and have a uniform diameter and a uniform diameter in the axial direction. The oil holes 1a and 1b are separated from each other by a predetermined distance at both ends of the drill 1. Further, the drill 1 is composed of a tip portion 8 having a cutting edge 2 and a twisted blade groove (flute) 3, and a shank portion 9 continuously extending from the tip portion 8.

The twisted blade groove 3 is a right-handed blade groove in FIG. 3. The twisted blade groove 3 is provided on the entire tip portion 8 and has a function of discharging cutting chips during processing. On the other hand, on the outer peripheral surface of the shank portion 9 of the drill 1, a plurality of (for example, two) mist grooves 4a and 4b that serve as mist passages are provided in the axial direction. The mist groove 4 has, for example, a triangular cross-section that is uniform in the axial direction, and the end portion of the twisted blade groove 3 at the tip portion 8 (the right end in FIG. 3) and the axial end portion of the shank portion 9 are formed. Connected to. The drill 1 having such a shape is formed by the inner peripheral contact portion (serving portion) 5c of the collet (holding member) 5c provided at the tip of the spindle 6 that rotates during machining of the semi-dry processing device 15 6 is fixed and attached. In addition, the inner diameter of the collet 5 also has mist grooves 5a and 5b which serve as mist passages.
Are formed in a plurality of (for example, two) axial directions. The mist grooves 5a, 5b have the same cross-sectional area in the axial direction, and are formed in parallel in the circumferential direction in the inner diameter of the hole for holding the drill 1 opened in the center of the collet 5. When the drill 1 is fixed to the spindle 6 by the collet 5, the mist 35 generated by the mist generator 30 passes through the oil holes 1a and 1b inside the drill, and the mist groove 4 (4a) on the outer peripheral surface of the drill. , 4b,), 5a, 5
It is designed to be supplied to the cutting edge of the drill 1 through b.

With such a configuration, the mist 35 generated by the mist supply device 30 during machining is supplied to the mist conduit 7 in the spindle at a predetermined pressure. And
The mist 35 passes through the oil holes 1a and 1b and the tip portion 8
Is discharged from the tip of the mist groove 4a, 4b, 5
It is discharged to the twisted blade groove 3 through the portions a and 5b at the rising portion of the twisted blade groove 3 (the end portion on the shank portion 9 side). The mist 35 discharged into the twisted groove 3 is
It collides with and adheres to the inclined surface of the spiral blade groove 3, gradually moves to the tip of the drill 1 by the force of the mist 35 to discharge, and adheres to the entire spiral blade groove 3. As a result, it is possible to prevent the chips of the work 45 from welding to the twisted blade groove 3 during machining. Therefore, the welding resistance at the time of machining is improved, and even if the machining is performed at high speed, the chips are discharged outside without being clogged in the twisted groove 3, so that the drill 1 can be reliably prevented from being damaged. Becomes

Next, a method of designing the semi-dry processing system 10 which discharges a constant and stable mist 35 will be described.

Normally, when semi-dry machining is performed using a cutting tool (for example, a drill) 1 having various diameters of oil holes 1a and 1b, the pressure P3 at the inlet of the mist generator 30 is set to a constant pressure. However, since the cross-sectional area S1 of the oil holes 1a and 1b changes, the pressure P4 at the outlet of the mist generating device 30 changes greatly. Therefore, the differential pressure between the inlet and the outlet of the mist generator 30 is set to P5.
If (= P3−P4), the differential pressure P5 varies depending on the cross-sectional areas of the oil holes 1a and 1b formed in the cutting tool. As a result, mist with a small particle size cannot be constantly generated. Therefore, in order to solve this, it is necessary to keep the cross-sectional areas of the oil holes 1a and 1b constant, but in the case of a cutting tool having a small diameter, the size of the oil hole is limited. I know.

In this case, when the cross-sectional areas of the surfaces of the oil holes 1a and 1b formed inside the drill 1 perpendicular to the axial direction are respectively s11 and s12, the sum total thereof is S1 (=
s11 + s12), and the cross-sectional areas of the surfaces of the mist grooves 4a, 4b, 5a, 5b formed between the drill 1 and the collet 5 perpendicular to the axial direction are s21, s22, s23, respectively.
If s24, then the total sum is S2 (= s21 + s22
+ S23 + s24), the sum of the cross-sectional areas through which these mists pass is defined as the mist discharge cross-sectional area S3, and the resistance of the air flow path through which the mist 35 between the mist generator 30 and the cutting tool flows is greater than the effects of S1 and S2. Very small,
A method of designing the semi-dry processing system 10 when ignored will be described below. In the present embodiment, two mist grooves 4a, 4b, 5a, 5b of the oil holes 1a, 1b, the drill 1 or the collet 5 are provided, but the number thereof is not limited to this, and the number thereof is not limited to this. Even when the number is increased or decreased, S1 is the total cross-sectional area of the plurality of oil holes, and S2 is the total cross-sectional area of the plurality of mist grooves.

When the mist discharge pressure P4 from the mist generator 30 is fixed at a predetermined pressure Pm, P3 changes depending on the mist discharge cross-sectional area S3 (see FIG. 5). At this time, the pressure difference between the inlet and the outlet of the mist generator 30 is set to P5 (= P3−
Pm), and the particle diameter M1 of the mist generated by the mist generator 30 changes depending on the pressure of the differential pressure P5 (see FIG. 6). However, as shown in FIG. 6, this mist particle size M1 becomes Md at a pressure with a differential pressure P5, which is characteristically
Saturate. The saturated mist particle size Md becomes the minimum particle size generated by the mist generator 30. This is a sufficiently small particle size so that when the spindle 6 rotates, the centrifugal force generated by the rotation of the spindle does not cause the mist of the semi-dry processing device 15 to adhere to the inner wall of the pipe that passes through. By these conditions, the minimum particle size Md of the mist 35
The differential pressure P5 of the mist generator 30 for obtaining
d, and the mist discharge cross-sectional area S3 at that time is determined as S3min.

When the mist 35 is discharged, the condition for adhering to the target when it collides with the target is determined by the mist particle size M1 and the mist flow velocity V1 discharged from the drill 1 (see FIG. 7). ). That is, the minimum value Vmi of the mist flow velocity V1 for the mist 35 to adhere to the work 45 and the drill 1.
n is uniquely determined by the minimum particle size Md of the mist 35, and is determined from the characteristic diagram (see FIG. 8) determined by the mist flow velocity V1 and the mist discharge cross-sectional area S3. The cross-sectional area of the intersection determines S3max, which is the maximum value of the mist discharge cross-sectional area S3.

By such a designing method, the sum S1 of the cross-sectional areas of the oil wheels 1a and 1b and the mist formed at the inner peripheral abutting portion which becomes the outer peripheral surface of the drill 1 and the inner peripheral holding portion 5c of the collet 5. Mist discharge cross-sectional area S3 (= S1), which is the sum of the cross-sectional area S4 with the grooves 4a, 4b, 5a, 5b.
+ S2), the oil holes 1a and 1b and the mist grooves 4a, 4b, 5a and 5b are designed so that the relational expression of S3min ≦ S1 + S2 ≦ S3max is satisfied. With such a design, if the cross-sectional areas S1 and S2 are designed so that S1 + S2 = constant by each cutting tool attached to the spindle 6,
Generates stable mist 35 of the smallest particles from the drill 1,
It can be supplied to the surface of the work 45 and the drill 1. As a result, even when a small-diameter drill is used, even when the cross-sectional area S1 through which the mist 35 of the oil holes 1a and 1b formed inside the drill 1 passes is small, in the case where a mist with the smallest particle size is generated in S1, By supplying the insufficient mist 35 in the cross-sectional area S2 from the outer periphery of the drill 1, the stable mist 35 can be discharged from the drill 1.

Further, in order to supply the stable mist 35, the pressure increasing device 20 and the pressure reducing device 25 are used in this embodiment. That is, the air from the air source 39 is boosted, and the boosted air is constantly kept at a constant pressure.
I am trying to supply it to. Explaining below, first, factory air (supply pressure Pi Pi:
The minimum guaranteed pressure in consideration of pressure fluctuation) is, for example, the filling time per 10 liters (10 ⁻² m ³ ) T1 = f (P
The pressure intensifier 22 having the characteristic of (2 / P1) (see FIG. 9) increases the pressure P2 to a pressure higher than the pressure Pm desired to be used (pressure desired to be generated by the mist generator 30) Pm. Then, the boosted air is stored and stored in the buffer tank 23 having the volume B1, and immediately before the mist generating device 30, a pressure reducing device 25 called a regulator that outputs a predetermined pressure is used to reduce the pressure of the pressure reducing device 25. Set pressure P
Depressurize to 6.

In this way, the pressure P2 thus increased is increased to a pressure higher than the set pressure P6 of the pressure reducing device 25, and then stored in the buffer tank 23, whereby the mist generating device 3
When the mist 35 is generated from 0, the pressure P3 at the inlet can always be kept constant. In this case, in order to determine the pressures P2 and P6 and the capacity B1 of the buffer tank, it is necessary to satisfy P3 ≧ Pd + Pm. Therefore,
The pressure P3 supplied to the inlet of the mist generator 30 is designed to be as small as possible, so P3 =
Pd + Pm is the most efficient, and the relationship expressed by the following equation may be established.

[0032]

[Equation 1] In the cutting tool that is machined for the longest time during machining, Ta is the time during which the mist 35 is being discharged, and Tb is the time during which the mist 35 is not actually discharged onto the workpiece 45 due to replacement of the cutting tool or the like. Mist flow rate to be F
In the case of 4, when designing the pressure booster 20 and the pressure reducer 25, the pressure P4 at the outlet of the mist generator 30 and the mist discharge cross-sectional area S3 are fixed according to equation (1).
In this case, the mist flow rate F4 is also uniquely determined, and the mist flow rate F4 at that time is set to F4 = Fm. When the volume of the mist 35 consumed when the continuous mist is discharged is B2, B2 = Ta · Fm.

When the volume of the air stored in the buffer tank 23 is B3, B3 = P2.
It becomes B1 / 0.1013. This "0.1013" is
Indicates atmospheric pressure expressed in megapascals.

Here, if the relationship of B2 ≦ B3 is satisfied, the pressure drop of the pressure P3 at the inlet of the mist generating device 30 does not occur at the time of mist generation, so that the relationship of the following equation is satisfied. You can do it.

[0035]

[Equation 2] Further, the buffer tank 23 needs to be filled with Ta + Tb, and when the maximum time required to fill the buffer tank 23 is Tmax,

[Equation 3] Therefore, it must be Ta + Tb or less. Therefore, it is necessary to satisfy the following equation.

[0036]

[Equation 4] With the above method, the set pressure P6 of the decompression device 25 is determined from the relational expression of the expression (1). In addition, the buffer tank 2 that simultaneously satisfies the relational expressions (2) and (4)
By determining the pressure P2 of 3 and the capacity B1 of the buffer tank 23, the pressure booster 20 and the pressure reducer 25 can be designed. In the present embodiment, as an example, Pi =
When 0.4, Pm = 0.5, Ta = 3, Tb = 6, P2 = 0.8, P6 = 0.6, B1 = 38, S3 =
3 (pressure unit: MPa, volume unit: liter, cross-sectional area:
It is designed to have a setting of mm ² ).

[0037]

According to the present invention, in the semi-dry machining apparatus, in addition to the first mist passage formed inside the cutting tool, the second mist passage for guiding the mist holds the cutting tool of the semi-dry machining apparatus. Since it is formed on the holding portion of the member and / or the surface of the cutting tool, the mist generated by the mist generating device can be discharged through the first mist passage and the second mist passage. At this time, even if the first mist passage formed in the cutting tool is narrow, the mist can be supplied from the second mist passage of the holding member that holds the cutting tool, and the mist pressure, regardless of the type of cutting tool, The mist flow rate can be secured and kept constant.

In this case, if a pressure increasing device for increasing the pressure of the pressure source and storing it is provided between the pressure source and the mist generating device, the increased pressure is stored and supplied to the mist generating device. can do. At this time, even if the pressure source fluctuates, the stored pressure is supplied to the mist generator, so that a stable pressure can be supplied to the mist generator, and an expensive compressor or the like can be used to increase the pressure. No equipment required. Therefore, the system configuration is inexpensive.

Further, the pressure stored in the pressure booster is set to be higher than the pressure at which the mist generator produces mist having the smallest particle size, so that the pressure difference between the inlet and the outlet of the venturi type mist generator is set. You can secure it without lowering it,
The mist generator has a configuration capable of stably generating the mist having the smallest particle size.

In this case, by fixing the pressure of the mist to a predetermined pressure, the mist generator can generate the mist having the minimum particle size in a more stable state.

Further, since the pressure reducing device for reducing the pressure stored in the pressure increasing device to the pressure at which the mist generating device produces mist having the minimum particle size is provided between the pressure increasing device and the mist generating device, The decompression device ensures a certain differential pressure for the mist generator to generate the minimum particle size, and has a system configuration capable of generating stable mist.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a semi-dry processing system according to an embodiment of the present invention.

FIG. 2 is a front view of a drill used in the semi-dry machining system according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram when a drill is attached to a spindle used in the semi-dry machining system according to the embodiment of the present invention.

FIG. 4 is a graph showing a relationship between a cross-sectional area S1 of an oil hole formed in a drill used in a semi-dry machining system and a pressure P4 at an outlet of a mist generator.

FIG. 5 is a cross-sectional area S1 of an oil hole formed in the drill of the semi-dry machining system according to the embodiment of the present invention.
3 is a graph showing the relationship between a mist discharge cross-sectional area S3, which is the sum of the cross-sectional area S2 of the mist passage formed in the collet, and the pressure P4 at the inlet of the mist generator.

FIG. 6 is a graph showing the relationship between the pressure difference P5 at the inlet and the outlet of the mist generator of the semi-dry processing system and the mist particle size M1 in the embodiment of the present invention.

FIG. 7 is a graph showing the relationship between mist particle size and mist flow velocity V1 in the semi-dry processing system according to the embodiment of the present invention.

FIG. 8 is a graph showing the relationship between the mist discharge cross-sectional area S3 and the mist flow velocity V1 in the semi-dry processing system according to the embodiment of the present invention.

FIG. 9 is a graph showing filling characteristics of the pressure boosting unit of the semi-dry processing system according to the embodiment of the present invention.

[Explanation of symbols]

1 drill (cutting tool) 1a, 1b Oil hole (first mist passage) 5 Spindle (holding member) 4a, 4b, 5a, 5b mist groove 5c holding part 10 Semi-dry processing system 20 Pressure booster 25 Decompression device 30 Mist generator 35 mist 39 Pressure source 45 work (workpiece)

Claims (5)

[Claims] 1. A pressure source, a Venturi type mist generating device for generating mist by the pressure from the pressure source, a first mist passage is formed inside a cutting tool, and the mist generated by the mist generating device is In a semi-dry processing system including a semi-dry processing device that sprays the mist from the cutting tool onto a workpiece to be processed, which is guided to the cutting edge or the surface of the cutting tool by the first mist passage, The second mist passage that guides the mist,
A semi-dry machining system, wherein the semi-dry machining system is formed on a holding portion of a holding member that holds the cutting tool of the semi-dry processing apparatus and / or a surface of the cutting tool. 2. The semi-dry processing system according to claim 1, further comprising a pressure increasing device for increasing and storing the pressure of the pressure source between the pressure source and the mist generating device. 3. The semi-dry processing system according to claim 2, wherein the pressure stored in the pressure boosting device is set to be higher than the pressure at which the mist generating device produces mist having a minimum particle size. 4. The semi-dry processing system according to claim 3, wherein the pressure of the mist is fixed to a predetermined pressure. 5. A pressure reducing device for reducing the pressure stored in the pressure increasing device between the pressure increasing device and the mist generating device to a pressure at which the mist generating device generates mist having a minimum particle size. The semi-dry processing system according to claim 3 or 4, wherein the semi-dry processing system is provided.