KR102345794B1 - Method for designing a drill for composite head with improved dust suction performance and the drill for composite head designed thereby and the composite head using the drill - Google Patents

Abstract

The present invention relates to a method for designing a drill part for a composite head with improved dust suction performance, a drill part for a composite head designed thereby, and a composite head including the same.
In the method of designing a drill part for a composite head with improved dust suction performance of the present invention, a drill part and a water jet having a drill housing are installed in the composite head, respectively, and the drill housing has an upper housing having a discharge pipe formed on one side and a lower part of the upper housing A method for designing a drill part for a compound head including a housing connector formed in the , a lower housing formed under the housing connector, and a connector formed between the upper housing and the discharge pipe, an objective function in consideration of the shape of the drill part and a design variable determination step; a design region selection step of determining upper and lower limits of the design variables; combining design variables in the selected design area; determining a major design variable having a major influence on the objective function by a ^2k factorial experiment method among the combined design variables; Numerical analysis in the selected design area and searching for an optimal point in the design area through the numerical analysis result.

Description

A method for designing a drill part for a composite head with improved dust suction performance, a drill part for a composite head designed thereby, and a composite head including the same the composite head using the drill}

The present invention relates to a method for designing a drill part for a composite head with improved dust suction performance, a drill part for a composite head designed thereby, and a composite head including the same.

In recent years, the use of carbon fiber composites is rapidly increasing in various industries as the demand for weight reduction according to global environmental regulations increases in the aircraft, automobile, and display industries. Here, Carbon Fiber Reinforced Plastics (CFRP) is a composite material made of carbon fiber and plastic resin. Compared to commonly used steel materials, the tensile strength is about 2 times higher and the density is 25% or less, so the mechanical properties are poor. It has excellent features and is light in weight.

However, the CFRP dust generated by the processing of carbon fiber composites deteriorates not only the quality but also the work environment, and when directly introduced into the respiratory tract of the worker, causes various respiratory diseases. It can cause eye disease. In order to solve this problem, the quality and working environment have been improved by developing a multi-tasking head equipped with both a drilling head and a waterjet head.

A gantry type complex machine tool that has both drilling, which is an important processing method of a workpiece, drilling that can work with routing, and a waterjet that can cut the workpiece at the same time. It has a structure in which each is separately installed on one cross rail.

As such a conventional composite head, there is a "drilling and waterjet composite head" (hereinafter referred to as a prior art) disclosed in Korean Patent Registration No. 10-2028904.

In this way, the composite head equipped with drilling and waterjet causes a pressure loss when suctioning CFRP dust, which lowers the effect of inhaling the dust. has occurred

It was devised based on the technical background as described above, and the present invention traps dust while CFRP is being processed, and draws a shape of the drill part that can minimize the pressure loss when CFRP dust is sucked to design the drill part, so that the pressure loss An object of the present invention is to provide a method for designing a drill part for a compound head with improved dust suction performance that can minimize

In order to achieve the above object, in the present design method of the drill part for the composite head with improved dust suction performance, a drill part and a water jet having a drill housing are installed in the composite head, respectively, and the drill housing is an upper part having a discharge pipe formed on one side. A method for designing a drill part for a compound head comprising a housing and a housing connection pipe formed under the upper housing, a lower housing formed under the housing connection pipe, and a connection pipe formed between the upper housing and the discharge pipe, wherein the drill part determining the objective function and design variables in consideration of the shape; a design region selection step of determining upper and lower limits of the design variables; combining design variables in the selected design area; determining a major design variable having a major influence on the objective function by a ^2k factorial experiment method among the combined design variables; It may include a step of numerical analysis in the selected design area and the step of searching for an optimal point in the design area through the numerical analysis result.

The objective function is a pressure loss rate (p), and the design variable is a diameter (D1) of the lower end of the drill housing that can affect the objective function, and a first height (L1) that is a length in the vertical direction of the lower housing , a second height (L2) that is a length in the vertical direction of the upper housing and a length (T1) of the connection pipe located between the drill housing and the discharge pipe.

In the design area selection step of determining the upper and lower limits of the design variable, the diameter (D1) is 68 mm or more and 140 mm or less, the length (T1) of the connecting pipe is 5 mm or more and 15 mm or less, and the first height (L1) ) may be 45 mm or more and 65 mm or less, and the second height L2 may be 67 mm or more and 87 mm or less.

Among the combined design variables, the diameter (D1), the length of the connecting pipe (T1), the first height (L1), and the second height in the step of determining the main design variables that have a major influence on the objective function by the ^{2k factor experiment method} (L2) can be combined to determine the sensitivity of the objective function.

In the step of searching for the optimum point in the design area through the numerical analysis result, the optimum point may be searched through the slope and contact point of the resistance curve and the pressure curve formed in the selected design area.

In the step of searching for an optimal point in the design area through the numerical analysis result, an optimal design variable value can be determined through a numerical analysis and an optimal shape can be determined.

The design region selection step may further include a boundary condition fixing step of fixing a boundary condition to determine the objective function for the design variable.

Atmospheric pressure at the lower end of the drill housing, the mass flow rate in the discharge pipe, the working fluid may be fixed to 25 ℃ air.

The optimal point may be 140 mm in diameter D1, 15 mm in length T1 of the connector, 45 mm in first height L1, and 87 mm in second height L2.

In order to achieve the above object, the drill part for the compound head designed by the design method of the drill part for the compound head with improved dust suction performance is for a compound head with improved dust suction performance according to any one of claims 1 to 9 It may be a drill part for a compound head designed by the design method of the drill part.

The housing connection pipe may be formed to have a smaller cross-sectional area from the top to the bottom.

A first central axis formed in the center of the discharge pipe may be disposed to be positioned on the same line as a second central axis of a first height of the upper housing.

The connecting pipe may be formed to be inclined at a predetermined angle so that the cross-sectional area of the connecting pipe becomes gradually smaller toward the discharge pipe from the drill housing.

The connecting pipe may be inclined at 30 degrees to 60 degrees.

The connector may be inclined at 45 degrees.

The upper housing, the lower housing, and the housing connection pipe may have the same diameter.

The length T1 of the connector includes a first horizontal length X1 indicating a horizontal length and a first vertical length Y1 indicating a vertical length, and the ratio of the first horizontal length to the first vertical length is It can be 1:1.

The drill part may include a moving member connected to the upper part of the drill member so that the drill member can move up and down.

In order to achieve the above object, the compound head including the drill part for the compound head designed by the design method of the drill part for the compound head with improved dust suction performance is for the compound head according to any one of claims 10 to 18. It may be a composite head including a drill part.

The design method of the drill part for the compound head with improved dust suction performance according to the present invention can minimize the pressure loss by deriving the shape of the drill part that minimizes the pressure loss to design the drill part for the compound head with the improved dust suction performance. have.

A composite head including a drill part for a composite head designed by the method for designing a drill part for a composite head with improved dust suction performance according to the present invention can easily process or cut a carbon fiber composite material as a work object with one head.

The drill part for the compound head designed by the design method of the drill part for the compound head with improved dust suction performance according to the present invention can effectively suck the dust generated when the connection pipe is connected to the drill housing and processed or cut.

The drill part for the compound head designed by the design method of the drill part for the compound head with improved dust suction performance according to the present invention allows the moving member to move the drill member for processing the work object up and down to easily drill the work object.

The drill part for the compound head designed by the design method of the drill part for the compound head with improved dust suction performance according to the present invention is formed with a dust suction port at the lower end of the lower housing, so that the dust generated when drilling the workpiece can be easily sucked. .

The drill part for the compound head designed by the design method of the drill part for the compound head with improved dust suction performance according to the present invention is formed in a 1:1 ratio of the first horizontal length and the first vertical length of the connecting pipe, so that when dust is sucked By reducing the pressure loss by minimizing the resistance, the dust can be easily sucked in.

The drill part for the compound head designed by the design method of the drill part for the compound head with improved dust suction performance according to the present invention can easily inhale dust, and by changing the existing housing to a minimum, additional cost incurred during manufacturing can reduce

1 is a flowchart illustrating a design method of a drill part for a composite head with improved dust suction performance of the present invention.
Figure 2 is a side view of a compound head including a drill part for the compound head of the present invention.
3 is a cross-sectional view of a drill part according to the first embodiment of the present invention.
4 is a view showing the design parameters of the drill part according to the first embodiment of the present invention.
5 is a cross-sectional view showing a drill part according to a second embodiment of the present invention.
6 is a cross-sectional view showing a drill part according to a third embodiment of the present invention.
7 shows a reference drill part.
8 shows the boundary conditions of the drill part.
9 is a graph showing a change in pressure loss according to a change in design parameters of the drill part according to the first embodiment of the present invention using a main effect plot.
10 is a view showing for minimizing the pressure loss of the drill part according to the first embodiment of the present invention.
11 shows a comparison of the respective embodiments of the drill part according to the present invention and the reference drill part.
Figure 12 shows a comparison of the pressure loss of each of the drill part according to the present invention and the reference drill part.
13 is a graph showing the results of the grid test of the drill part according to an embodiment of the present invention.
14 is a graph comparing a resistance curve and a pressure curve of the drill part according to the first embodiment of the present invention.
15 is a graph comparing resistance curves according to changes in design variables.
16 is a graph showing the degree of influence of design variables on pressure loss.
17 is a view showing the internal flow flow of the reference drill part.
18 is a view showing the internal flow of the drill part according to the third embodiment of the present invention.
19 is a graph showing the degree of pressure loss according to the respective embodiments of the drill part according to the present invention and the degree of pressure loss of the reference drill part.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

First, a drill part for a compound head and a compound head including the same will be described with reference to FIGS. 2 to 6, and then a design method (S100) of a drill part for a compound head with improved dust suction performance will be described.

2 is a front view of a composite head including a drill part for a composite head designed by the design method of a drill part for a composite head with improved dust suction performance of the present invention.

Referring to FIG. 2 , the composite head 100 including the drill part for the composite head of the present invention has a body part 110 and a driving part 120 in order to improve the suction performance of the carbon fiber composite material by minimizing the pressure loss. ), a rotating unit 130 , a water jet 150 and a drill unit 170 may be included.

In addition, the composite head 100 according to the present invention sucks the dust generated when processing carbon fiber reinforced plastics (CFRP) at the same time as processing and prevents it from being finely discharged to the outside, thereby causing equipment failure and fire. occurrence can be prevented in advance.

The composite head 100 of the present invention switches the use of the drill unit 170 and the waterjet 150 according to the processing process of the workpiece, and the conversion and each process of the drilling process and the cutting process in the entire section moving along the left and right directions is possible to perform

On the other hand, the body part 110 may be formed with a receiving part (not shown) so that the rotating part 130 can be coupled therein. The lower end of the body 110 may have a semicircular cross-section. A driving unit 120 formed in a cylindrical shape is connected to the upper portion of the body 110 to rotate the rotating unit 130 to the left and right with respect to the body 110 .

A driving motor (not shown) for rotating a shaft (not shown) may be installed in the driving unit 120 . In this case, the shaft may be connected to the rotating unit 130 to transmit the driving force of the driving motor to the rotating unit 130 . In addition, the driving unit 120 may have parts such as a bearing, a casing, a connecting boss, and a bolt for connecting the driving motor to the body unit 110 therein.

The rotating part 130 may be rotatably connected to the lower end of the body part 110 . At this time, the rotating unit 130 may reciprocate left and right in a predetermined angle range. The waterjet 150 may be installed on the left side of the rotating unit 130 , and the drilling unit 170 may be installed on the lower side of the rotating unit 130 . A processing motor (not shown) connected to the body part 110 is installed inside the rotating part 130 to provide driving force to the drill part 170 and the waterjet 150 .

The waterjet 150 may be formed to protrude from the left side of the rotating unit 130 in order to cut or process the workpiece. In this case, the waterjet 150 may be connected to a processing motor installed inside the rotating unit 130 and may receive water and abrasives supplied from the outside to spray it.

The waterjet 150 may be cut by spraying water or an abrasive on a workpiece such as a carbon fiber composite material. A drill part 170 may be installed in the rotation part 130 at a position orthogonal to the waterjet 150 .

The drill part 170 may suck in dust generated at the same time as drilling or processing a work piece such as a carbon fiber composite material.

3 is a cross-sectional view of a drill part according to a first embodiment of the present invention, FIG. 5 is a cross-sectional view showing a drill part according to a second embodiment of the present invention, and FIG. 6 is a drill part according to a third embodiment of the present invention It is a cross section.

Hereinafter, each embodiment of the drill part according to the present invention will be described in order from an embodiment having a low suction pressure loss rate, and expressing the first embodiment, the second embodiment, and the third embodiment distinguishes each embodiment This is only for the purpose of doing so, and may not give meaning to the order of the embodiments.

Referring to Figure 6, the drill unit 300 according to the third embodiment of the present invention is a drill housing 171, a fixing member 172, in order to process a workpiece such as a carbon fiber composite and suck the dust generated at this time, It may include a moving member 173 , a drill member 175 , a discharge pipe 177 , and a connection pipe 178 .

The drill housing 171 may have a fixing member 172 , a moving member 173 and a drill member 175 installed therein.

The discharge pipe 177 may be formed on one side of the drill housing 171 , and the dust formed inside the drill housing 171 may be discharged to the outside through the discharge pipe 177 . The discharge pipe 177 is formed in a cylindrical shape to minimize the loss of pressure generated when the dust is sucked from the drill housing 171, thereby improving the dust suction performance of the carbon fiber composite.

A connection pipe 178 may be formed between the drill housing 171 and the discharge pipe 177 . The connection pipe 178 may be formed in a ring-shaped cross-section. The connection pipe 178 may be formed to be inclined. That is, the connection pipe 178 is formed to have a narrower diameter toward the discharge pipe 177 from the drill housing 171 , thereby minimizing pressure loss and improving the dust suction performance of the carbon fiber composite material. Additionally, the connecting pipe may be inclined at 30 to 60 degrees, and when it is inclined at 45 degrees, pressure loss may be minimized.

The connection pipe 178 may be formed with a predetermined diameter (D1). And, the connection pipe 178 is provided with a predetermined length (T1), the length (T1) of the connection pipe 178 is the inclined length of the outer peripheral surface,

The length T1 of the connector 178 may be formed of a first horizontal length x1 indicating a horizontal length and a first vertical length y1 indicating a vertical length. In this case, the first horizontal length x1 and the first vertical length y1 may be formed to be inclined at a 1:1 ratio, that is, at an angle of 45 degrees. That is, since the first horizontal length (x1) and the first vertical length (y1) are formed in the same ratio, the pressure loss can be further reduced and the discharge efficiency can be increased to the maximum value. In addition, since the first horizontal length x1 and the first vertical length y1 are formed at an angle between 30 and 60 degrees, it is possible to further reduce the pressure loss, thereby increasing the discharge efficiency.

In other words, the connection pipe 178 may reduce suction pressure loss generated when dust is sucked from the inside of the drill housing 171 to the discharge pipe 177 .

In addition, a second central axis C2 may be formed at the center point of the discharge pipe 177 and the connection pipe 178 , and the second central axis C2 is the central axis of the overall height L5 of the drill housing 171 . (Cd) and may be arranged to be located on the same line. In other words, the discharge pipe 177 may be installed in the center of the drill housing 171 , and the second central axis C2 of the discharge pipe 177 and the connection pipe 178 is the central axis Cd of the drill housing 171 . ) by being formed on an extension line of the drill housing 171 , it is possible to reduce the pressure loss when the dust and airflow inside the exhaust pipe 177 are discharged through the discharge pipe (177).

The fixing member 172 may have an upper portion installed inside the rotating part 130 and a lower portion installed inside the drill housing 171 . In addition, the upper portion of the fixing member 172 may be connected to a processing motor connected to the body portion 110 . In addition, the moving member 173 may be installed inside the fixing member 172 .

In addition, the moving member 173 may be drawn into the inside of the fixing member 172 or withdrawn upward. That is, the moving member 173 may be moved in the vertical direction.

In addition, a drill member 175 may be coupled to a lower portion of the movable member 173 . The drill member 175 may be formed of a material such as diamond.

In summary, the fixing member 172 can place the drill member 175 at a position where the drilling process is to be performed, and the movable member 173 is moved up and down and the drill member 175 is moved up and down to perform the drilling process. can

The drill member 175 may be formed to be capable of drilling a workpiece such as a carbon fiber composite material. At this time, an elastic member is coupled to the outer surface of the drill member 175 to alleviate the impact generated while the drill member 175 is in close contact with a work piece such as a carbon fiber composite material.

3 and 5, the drill parts 170 and 200 according to the first or second embodiment of the present invention include a drill housing 171, a fixing member 172, and a moving member 173. , may include a drill member 175, a discharge pipe 177, the drill housing 171 may include an upper housing (171a), a housing connection pipe (171b) and a lower housing (171c), of the present invention The drill part 170 according to the first embodiment may further include a connection pipe 178 . Further, since the drill housing 171, the fixing member 172, the moving member 173, the drill member 175, and the discharge pipe 177 are the same as those described in the drill part 300 according to the third embodiment, detailed description is to be omitted.

The upper housing 171a may be formed in a cylindrical shape with a ring-shaped cross-section. As shown in FIG. 2 , the upper housing 171a may be connected to a lower portion of the rotating part 130 . The upper housing 171a may be formed to extend downwardly by a second height L2 from the lower surface of the rotating part 130 . A first central axis C1 may be formed at a central point of the second height L2 .

A discharge pipe 177 is installed on the left or right side of the upper housing 171a to discharge dust generated through the drill member 175 to the outside.

On the other hand, the upper housing (171a) may be connected to the housing connection pipe (171b) at the lower end. The housing connection pipe 171b may be formed to be inclined toward the lower portion. That is, the housing connection pipe 171b may be formed to have a smaller cross-sectional area from the top to the bottom. A lower housing 171c may be formed at the lower end of the housing connection pipe 171b.

In other words, the housing connection pipe 171b may be formed in a cylindrical shape to be tapered so that the diameter decreases from the top to the bottom.

The lower housing 171c may be formed in a cylindrical shape with a ring-shaped cross-section. The lower housing 171c may be formed to extend downwardly by a first height L1 from the lower surface of the inclined member 171b. The lower housing 171c may be formed to have the same diameter as the lower end of the housing connection pipe 171b. A diameter D1 of the lower housing 171c may be smaller than a diameter of the upper housing 171a.

A lower end of the lower housing 171c may be formed with a dust suction port 171d to be opened. The dust inlet (171d) may be formed in a circular shape having a diameter (D1). Dust generated when processing a workpiece such as a carbon fiber composite material may be sucked into the interior of the lower housing 171c through the dust suction port 171d.

Additionally, the diameter D1 is 68 mm or more and 140 mm or less, the length T1 of the connector is 5 mm or more and 15 mm or less, the first height L1 is 45 mm or more and 65 mm or less, and the second height ( L2) may be formed to be 67 mm or more and 87 mm or less, the diameter (D1) is 140.0 mm, the length (T1) of the connector is 15 mm, the first height (L1) is 45 mm, the second height (L2) is 87 When formed in mm, the pressure loss can be minimized.

Additionally, the upper housing 171a, the housing connection pipe 171b and the lower housing 171c may be formed to have the same diameter, and the discharge pipe 177 may be installed in the center of the drill housing 171. . In other words, when the upper housing 171a, the housing connection pipe 171b, and the lower housing 171c are formed to have the same diameter, the drill part 300 according to the third embodiment may be derived, and the third embodiment Since the drill part 300 according to the above has been described, a detailed description thereof will be omitted.

Referring to FIG. 3 , in the drill housing 171 according to the first embodiment of the present invention, a connection pipe 178 may be formed between the upper housing 171a and the discharge pipe 177 .

The connection pipe 178 may be formed in a ring-shaped cross-section. The connection pipe 178 may be formed to be inclined. That is, the connection pipe 178 is formed to have a narrower diameter toward the discharge pipe 177 from the upper housing 171a, thereby minimizing the pressure loss and improving the dust suction performance of the carbon fiber composite material.

In addition, a second central axis C2 may be formed at the center point of the discharge pipe 177 and the connection pipe 178 , and the second central axis C2 may be formed to be the same as the first central axis C1 . . In other words, the discharge pipe 177 may be installed in the center of the upper housing 171a, and the second central axis C2 of the discharge pipe 177 and the connection pipe 178 is the first central axis of the upper housing 171a. By being formed on the extension line of (C1), it is possible to reduce the pressure loss when the dust and airflow inside the upper housing (171a) are discharged through the discharge pipe (177).

In summary, the drill part 300 according to the third embodiment of the present invention includes a drill housing 171 , a fixing member 172 , a moving member 173 , a drill member 175 , a discharge pipe 177 and a connecting pipe ( 178), and the drill part 200 according to the second embodiment of the present invention has a drill housing 171, a fixing member 172, a moving member 173, a drill member 175, and a discharge pipe 177. ) and the drill housing 171 of the drill unit 200 according to the second embodiment is made of an upper housing (171a), a housing connection pipe (171b), and a lower housing (171c), the first embodiment of the present invention The drill unit 170 according to the first embodiment may include a drill housing 171 , a fixing member 172 , a moving member 173 , a drill member 175 , a discharge pipe 177 , and a connection pipe 178 . The drill housing 171 of the drill part 170 according to the first embodiment may include an upper housing 171a, a housing connection pipe 171b, and a lower housing 171c.

In addition, the drill parts 170 , 200 , 300 according to each embodiment of the present invention can improve suction performance by reducing pressure loss, and in particular, in the case of the drill part 300 according to the third embodiment, the pressure loss has a feature that can minimize In the case of the drill part 170 according to the present invention, the characteristics of the drill parts 200 and 300 according to the second embodiment and the third embodiment are compromised. This can be.

Hereinafter, a method of designing drill parts according to the present invention in order to improve the dust suction performance of the carbon fiber composite material by minimizing the pressure loss during dust suction will be described.

1, the drill part design method (S100) for the composite head according to the first embodiment of the present invention is an objective function and Design variable determination step (S110), design area selection step (S120) for determining upper and lower limits of design variables, combining design variables in the selected design area (S130), ^2k factor among the combined design variables Determining a major design variable having a major influence on the objective function by an experimental method (S140), performing a numerical analysis step (S150) in the selected design area, and searching for an optimal point in the design area through the numerical analysis result ( S160).

The drill part design method (S100) for the composite head according to the first embodiment of the present invention designs the flow path of the drill part for the composite head in order to effectively recover the carbon fiber composite (CFRP) dust generated during the operation of the composite head 100 can do. In order to effectively recover carbon fiber composite (CFRP) dust, it is possible to minimize the internal pressure loss by analyzing the internal flow characteristics of the composite head because it is necessary to design a flow path that minimizes the pressure loss.

And, prior to the following description, the reference drill part 20 is, as shown in FIG. 7 , an upper housing (171a), a lower housing (171b), a first embodiment of the present invention including a housing connection pipe (171c) Although the configuration of the drill housing 171 and the configuration of the drill housing 171 of the reference drill part 20 according to And, there is a difference in the configuration in which the connector 178 does not exist.

In the first embodiment of the present invention, the objective function and design variable determination step (S110) may determine the objective function and design variables in consideration of the shape of the compound head drill part. In addition, in the objective function and design variable determination step ( S110 ), a design variable for determining the shape of the drill part in order to minimize the objective function may be selected.

At this time, the objective function may be a pressure loss rate (p) indicating the degree to which the pressure is lost when the dust flows into the inside of the drill part 170 from the lower end of the drill housing 171 and is discharged to the discharge pipe 177 . That is, since the drill part design method ( S100 ) for the composite head has an objective to determine the shape of the drill part 170 to minimize the pressure loss rate (p), the objective function may be the pressure loss rate (p).

In the first embodiment of the present invention, the design variables recognized to affect the pressure loss rate (p), which is the objective function, are the first height (L1), the second height (L2), the diameter (D1), and the length of the connecting pipe ( T1).

At this time, the design variables considering the shape of the drill part for the composite head are the diameter D1 of the lower end of the drill housing 171 and the first height L1, which is the length in the vertical direction of the lower housing 171c, and the upper housing 171a. It may be a second height L2, which is the length in the vertical direction, and a length T1 of the connection pipe 178, which is a shape connected to the drill housing 171 and the discharge pipe 177, but is not limited thereto.

Here, the length T1 of the connection pipe 178 may include a first horizontal length X1 and a first vertical length Y1. At this time, when the first horizontal length X1 and the first vertical length Y1 are the same, suction pressure loss can be minimized.

In the first embodiment of the present invention, in the design region selection step ( S120 ) for determining the upper and lower limits of the design variable, an appropriate design region can be set by limiting the range of the design variable in order to minimize the pressure loss rate.

In the design area selection step (S120) for determining the upper and lower limits of the design variable, the diameter (D1) is 68 mm or more and 140 mm or less, the length (T1) of the connecting pipe is 5 mm or more and 15 mm or less, and the first height ( L1) may be 45 mm or more and 65 mm or less, and the second height L2 may be 67 mm or more and 87 mm or less.

When the design variables and the design area are determined in this way, an optimal grid system for analysis is formed. In the present invention, a test for removing grid dependence can be performed in the boundary condition of the drill part.

In addition, the grid system was created as an unstructured grid using ANSYS ICEM-CFD. In the step (S120) of selecting the fixed variable in the first embodiment of the present invention, a grid test may be performed to increase the reliability of the numerical analysis result, and the boundary condition of the drill part may be indicated.

13 is a graph showing the results of the lattice test of the drill part according to an embodiment of the present invention, and FIG. 8 is a view showing the boundary conditions of the drill part according to an embodiment of the present invention.

Referring to FIG. 13 , in order to increase the reliability of the numerical analysis result, a grid test of the composite head was performed, and it can be shown that the numerical analysis result is constant at about 2.3 million pieces.

In addition, the three-dimensional Reynolds-averaged Navier-Stokes equation can be used to analyze the incompressible turbulent flow of the composite head. In order to analyze the flow of turbulent flow, the turbulent model can use the SST model, which is advantageous for the prediction of flow separation.

In addition, the design region selection step may further include a boundary condition fixing step of fixing a boundary condition in order to determine an objective function for the design variable.

Here, the boundary condition at the lower end of the drill housing as the inlet is a uniform atmospheric pressure condition, the boundary condition at the discharge pipe as the outlet is the mass flow rate, and the working fluid is air at 25°C. can be fixed.

In the step (S130) of combining the design variables in the selected design area, the objective function is minimized by controlling the design variables of the diameter (D1), the first height (L1), the second height (L2), and the length (T1). A possible diameter D1, a first height L1, a second height L2, and a length T1 may be combined.

Among the design variables in the design area selected in the first embodiment of the present invention, in the ^{determining key design variable having a major influence on the objective function by the 2k} factorial experiment method (S140), the design variables in the selected design area are combined To do this, design of experiments can be used. The design of experiment method is a method to quantitatively measure the effect by selecting important causes from among the causes of abnormal fluctuations at a low cost.

In order to examine the flow characteristics due to the design variables of the drill unit 170 according to the first embodiment of the present invention, a ^2k factorial experiment method, which is one of the experimental design methods, may be used, and a commercial program Minitab 14 may be used for the analysis. . In other words, in the step of combining the design variables, it is possible to find out the change in suction pressure loss due to the design variables of the drill part through the ^{2k factor experiment method.} Through this, it is possible to determine the sensitivity of the objective function by combining the diameter (D1), the length (T1) of the connector, the first height (L1), and the second height (L2).

The selected design variable can analyze the change in suction performance according to the change of the design variable by using the ^{2k factor experiment and CFD.}

The ^{experimental conditions applied to the 2 k} factor test method are shown in Table 1 below.

[Table 1]

The 2 ^k factor test method is a method to determine the significance of each factor by performing an experiment on the level of each factor for k factors. At this time, in order to obtain all the effects of the ^four factors, the main effect and the interaction action of the factors must be obtained by setting the size of the experiment to 2 4 =16 times.

In the first embodiment of the present invention, in consideration of the number of factors of interest, the number of experiments that can be executed, cost, time, etc., a fractional factorial method for reducing the number of experiments by bridging high-order interactions with little meaning (fractional factorial) designs), a ^2k factor experiment was performed. Among the design variables combined in the first embodiment of the present invention, 16 combined design variables having a ^{major effect on the objective function by the 2k} factorial experiment method were determined in the step S130. Among the experimental points, the combination of design variables that have a major influence on the objective function is determined by the ^{2k factorial method.}

9 is a graph showing a change in pressure loss according to a change in a design variable according to the first embodiment of the present invention using a main effect plot.

The main effect of the design variables on the pressure loss was analyzed using a main effects plot. Combining the analysis results of the main effect chart, it is possible to know the degree to which the design variable affects the pressure loss, and in particular, the diameter (D1) of the lower end of the drill housing 171, which is the inlet of the drill unit 170 through which dust is sucked. Alternatively, the diameter D1 of the lower housing 171c has a large influence on the pressure loss. That is, a desired pressure loss value can be obtained by controlling the diameter D1 of the lower end of the drill housing 171 that is the inlet of the drill unit 170 or the diameter D1 of the lower housing 171c.

At this time, as the diameter D1, the second height L2, and the length T1 of the connecting pipe increase, the pressure loss may decrease. In addition, as the first height L1 decreases, the pressure loss may decrease. That is, the design variable affecting the pressure loss may affect the pressure loss in the order of the diameter (D1), the second height (L2), the first height (L1), and the length of the connecting pipe (T1).

In the numerical analysis step ( S150 ) in the design area selected in the first embodiment of the present invention, an objective function value may be obtained through numerical analysis at a plurality of experimental points. In addition, the internal flow characteristics of the composite head can be analyzed using computational fluid dynamics.

At this time, the boundary condition of the drill part 170 is set to the mass flow at the outlet under atmospheric pressure conditions, and the working fluid may be set to air at 25°C. In addition, the flow analysis of the drill unit 170 can be analyzed through ANSYS CFX-17.1, a commercial three-dimensional point fiber body analysis program.

In the first embodiment of the present invention, in the step of searching for the optimum point in the design domain through the numerical analysis result (S160), the optimum point is searched for in the design domain based on the result obtained in the numerical analysis step. In addition, the optimum point may be searched for through the slope and contact point of the resistance curve and the pressure curve. Referring to FIG. 14 , suction is generated at the junction where the resistance curve and the pressure curve meet. When the pressure loss is minimized, the slope of the resistance curve decreases, so the resistance curve (System curve) The contact point where the pressure curve and the pressure curve meet is shifted to the right and the suction amount is increased, so that the suction performance can be further improved. Therefore, the optimum point can be searched for by comparing whether the contact point where the system curve and the pressure curve meet is located further to the right. In addition, through numerical analysis, it is possible to determine the optimal design variable value and determine the optimal shape. And, the shape of the drill part 170 has a diameter (D1) of 140 mm, a length (T1) of the connection pipe is 15 mm, a first height (L1) is 45 mm, a second height (L2) is a point of 87 mm pressure loss can be minimized.

11 shows each embodiment of the drill part according to the present invention.

Figure 12 shows a comparison of the pressure loss of each of the drill part according to the present invention and the reference drill part.

11 and 12, the performance of the drill part derived through reaction fitting was verified using CFD, and when compared and analyzed with the performance of the reference drill part, the drill part derived through reaction fitting had a greater pressure loss than the reference drill part. It can be reduced by about 41%.

That is, by performing the flow path design of the drill part to improve the CFRP dust suction performance, the derived drill parts 170 , 200 , 300 may have improved dust suction performance than the reference drill part.

17 is a view showing the internal flow of the reference drill unit 20, Figure 18 is a view showing the internal flow of the drill unit 300 according to the third embodiment of the present invention.

Referring to FIGS. 17 and 18 , it can be seen that in the reference drill part 20, flow separation occurs in the internal flow flow inside or inside the discharge pipe 177, and the flow in the direction of the discharge pipe 177 is also not smooth. It can be seen that suction pressure loss occurs accordingly.

It can be seen that the drill part 300 according to the first embodiment of the present invention flows smoothly without causing flow separation in or near the discharge pipe 177, and thus the suction pressure loss is reduced. can

That is, it can be confirmed that the internal flow is improved compared to the reference drill part 20 .

The drill parts 170 , 200 , 300 manufactured by the method of designing a drill part for a compound head of the present invention will be summarized and described. Referring to FIG. 6 , the drill part 300 according to the third embodiment of the present invention includes a drill housing 171 , a fixing member 172 , a moving member 173 , a drill member 175 , a discharge pipe 177 and a connection. It may include a tube 178, and referring to FIG. 5, the drill part 200 according to the second embodiment of the present invention has a drill housing 171, a fixing member 172, a moving member 173, and a drill member. 175 and the discharge pipe 177, and the drill housing 171 of the drill unit 200 according to the second embodiment is an upper housing 171a, a housing connection pipe 171b, and a lower housing 171c. 3 , the drill part 170 according to the first embodiment of the present invention includes a drill housing 171 , a fixing member 172 , a moving member 173 , a drill member 175 , and a discharge pipe 177 . ) and a connection pipe 178, and the drill housing 171 of the drill part 170 according to the first embodiment includes an upper housing 171a, a housing connection pipe 171b, and a lower housing 171c. can

In addition, the drill parts 170 , 200 , 300 according to each embodiment of the present invention can improve suction performance by reducing pressure loss, and in particular, in the case of the drill part 300 according to the third embodiment, the pressure loss There is a feature that can minimize There is a characteristic, and in the case of the drill part 170 according to the first embodiment, the characteristics of the drill parts 200 and 300 according to the second embodiment and the third embodiment are compromised. There may be features that can greatly reduce the pressure loss.

19 is a graph showing the degree of pressure loss according to the respective embodiments of the drill part according to the present invention and the degree of pressure loss of the reference drill part.

Referring to FIG. 19 , Ref represents a pressure loss caused by the installation of the reference drill part 20 . Ref_Out_modi represents a pressure loss generated by the installation of the drill unit 200 according to the second embodiment of the present invention. 2k_center represents the pressure loss generated by the installation of the drill part 170 according to the first embodiment of the present invention. 2k_optimum is a graph showing the pressure loss generated by the installation of the drill part 300 according to the third embodiment of the present invention.

Referring to FIG. 19 , the drill part 200 according to the second embodiment of the present invention can reduce the pressure loss by about 15% to 17% compared to the reference drill part 20, and the second embodiment of the present invention The drill part 170 according to the first embodiment can reduce the pressure loss by about 33.5% to 35.5% compared to the reference drill part 20, and the drill part 300 according to the third embodiment of the present invention is the standard Compared to the drill part 20 , the pressure loss can be reduced by about 40% to 42%, and the drill parts according to the present invention can improve the dust suction rate compared to the reference drill part 20 .

Although the present invention has been described through preferred embodiments as described above, the present invention is not limited thereto, and various modifications and variations are possible without departing from the concept and scope of the following claims. Those in the technical field to which it belongs will readily understand.

100: compound head
110: body part 120: driving part
130: rotating part 150: water jet
170: drill part 171: drill housing
171a: upper housing 171b: housing connector
171c: lower housing 171d: dust inlet
172: fixed member 173: movable member
175: drill member 177: discharge pipe
178: connector C1: first central axis
C2: second central axis Cd: central axis
L1: first height L2: second height
L5: overall height D1: diameter
X1: first horizontal length Y1: first vertical length

Claims (19)

A drill part and a water jet having a drill housing are respectively installed in the composite head, and the drill housing has an upper housing having a discharge pipe formed on one side thereof, a housing connection pipe formed in the lower part of the upper housing, and a lower housing formed in the lower part of the housing connection pipe. And a method for designing a drill part for a composite head comprising a connection pipe formed between the upper housing and the discharge pipe,
determining an objective function and a design variable in consideration of the shape of the drill part;
a design region selection step of determining upper and lower limits of the design variables;
combining design variables in the selected design area;
determining a major design variable having a major influence on the objective function by a ^2k factorial experiment method among the combined design variables;
Numerical analysis step in the selected design area; and
Including the step of searching for an optimal point in the design area through the numerical analysis result,
In the objective function and design variable determination step, the objective function is the pressure loss rate (p), and the design variable is the diameter (D1) of the lower end of the drill housing that can affect the objective function, the vertical direction of the lower housing is the length of the first height (L1), the second height (L2), which is the length in the vertical direction of the upper housing, and the length (T1) of the connection pipe located between the drill housing and the discharge pipe,
The connection pipe is formed to be inclined at a predetermined angle so that the cross-sectional area of the connection pipe becomes gradually smaller toward the discharge pipe from the drill housing,
The connecting pipe is formed in a ring-shaped cross section,
The length (T1) of the connector is the inclined length of the outer peripheral surface of the connector,
The length T1 of the connector includes a first horizontal length X1 indicating a horizontal length and a first vertical length Y1 indicating a vertical length, and the ratio of the first horizontal length to the first vertical length is A design method for a drill part for a compound head with improved dust suction performance for one person. delete According to claim 1,
In the design area selection step of determining the upper and lower limits of the design variable, the diameter (D1) is 68 mm or more and 140 mm or less, the length (T1) of the connecting pipe is 5 mm or more and 15 mm or less, and the first height (L1) ) is 45 mm or more and 65 mm or less, and the second height (L2) is 67 mm or more and 87 mm or less.
According to claim 1,
Among the combined design variables, the diameter (D1), the length of the connecting pipe (T1), the first height (L1), and the second height in the step of determining the main design variables that have a major influence on the objective function by the ^{2k factor experiment method} A method of designing a drill part for a compound head with improved dust suction performance to determine the sensitivity of the objective function by combining (L2). According to claim 1,
In the step of searching for the optimum point in the design area through the numerical analysis result, for a composite head with improved dust suction performance, searching for the optimum point through the slope and contact point of the resistance curve and the pressure curve formed in the selected design area The design method of the drill part. According to claim 1,
The step of searching for an optimal point in the design area through the numerical analysis result is a design method of a drill part for a compound head with improved dust suction performance that determines the optimal design variable value through numerical analysis and determines the optimal shape. According to claim 1,
The design area selection step is a method of designing a drill part for a composite head with improved dust suction performance further comprising a boundary condition fixing step of fixing boundary conditions to determine the objective function for the design variable. 8. The method of claim 7,
A method of designing a drill part for a compound head with improved dust suction performance in which atmospheric pressure is at the lower end of the drill housing, the mass flow rate in the discharge pipe, and the working fluid is fixed to air at 25°C. According to claim 1,
The optimal point is for a compound head in which the diameter (D1) is 140 mm, the length (T1) of the connector is 15 mm, the first height (L1) is 45 mm, and the second height (L2) is 87 mm Drill part design method. [10] A drill part for a compound head designed by the method for designing a drill part for a compound head with improved dust suction performance according to any one of claims 1 to 9. 11. The method of claim 10
The housing connector is a drill part for a compound head formed so that the cross-sectional area becomes smaller from the upper part to the lower part. 11. The method of claim 10
The first central axis formed in the center of the discharge pipe is a drill unit for a compound head that is arranged to be positioned on the same line as the second central axis of the first height of the upper housing. delete delete delete 11. The method of claim 10
The upper housing, the lower housing and the housing connection pipe are a drill part for a composite head formed with the same diameter. delete 11. The method of claim 10,
The drill part is a drill member and a drill part for a compound head including a movable member connected to the upper portion of the drill member and moving the drill member up and down. A compound head comprising a drill part for the compound head according to claim 10.

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