Method for calculating path of machining tool of large component surface beveling machine

Abstract

According to the large component surface beveling machine machining tool path calculation method disclosed by the invention, a large component surface curve function, a large component middle layer curve function and a large component inner surface curve function of a large component surface curve are fitted through a large component circumferential surface point taking method; marking an intersecting line of each curvilinear function and a cylindrical surface intersecting with the machining radius R as a surface line, marking an intersecting line of each curvilinear function and a cylindrical surface intersecting with the outer groove radius Ru as an outer groove line, marking an intersecting line of each curvilinear function and a cylindrical surface intersecting with the radius Rd as an inner groove line, and marking an intersecting line of each curvilinear function and a cylindrical surface intersecting with the R as an inner surface line; a tool path for machining the outer groove and the inner groove of the large component is obtained through the conversion relation between the polar coordinates and the right-angle base, coordinate conversion is conducted on a tool nose point and the axis direction of a tool, and then a machine tool machining code can be obtained.

Description

Technical Field

[0001] The invention relates to a calculation method for a groove processing route, in particular to a calculation method for a tool path for groove machining on the surface of a large component. Background Art

[0002] In the actual groove processing process, since the welding groove on the surface of a large component can usually be considered to be formed by the intersection of cylindrical surfaces of different diameters, but the relative position of the machine tool reference plane and the surface of the large component is difficult to determine, the existing technology uses CNC machine tools to process the groove of the curved surface of large components. There is an inability to accurately plan the tool travel path, resulting in the outer groove line and the inner groove line of the two large components to be welded being discontinuous, uneven, and unable to be aligned, affecting the final welding effect. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for calculating the tool path for machining the surface groove of a large component, calculate the tool path for machining the outer groove line and the inner groove line of the groove, so that the groove line machined by the CNC machine tool according to the tool path is smoother and more coherent, thereby ensuring the quality of subsequent welding.

[0004] The length direction of the large component is the Y coordinate axis direction, the horizontal direction is the X coordinate axis direction, the cross section of the large component is parallel to the XZ plane, and the Z coordinate axis is coaxial with the axis of each cylindrical surface intersecting the surface of the large component.

[0005] The present invention claims a method for calculating a tool path for machining a large component surface groove, which specifically includes the following steps:

[0006] Step 1: Take points on the circumferential surface of the large component to fit the surface function of the large component;

[0007] Step 11: In the XZ plane, use the point-picking tool to touch the right half of the surface of the large component and record the coordinates of the tool tip point P when the point-picking tool is in contact. i (θ i ,Z i ), at this time the coordinates of the contact point between the large component surface and the point-taking tool are Q i (R u cosθ i ,Z i ), where θ i =(i-1)θ, i is the number of points, i≤N, to ensure that the range of points covers the entire processing area of the right half of the large component surface, Z i The tool tip point P at contact i The Z-axis coordinate value in the machine tool coordinate system, where R u is the radius of the intersecting cylindrical surface of the outer groove, θ is the angle of the point interval, and θ*N=180°;

[0008] Step 12: Use the point-picking tool to touch the left half of the large component surface and record the coordinates of the tool tip point P when touching. ′ i (θ i ,Z′ i ), at this time, the coordinate of the contact point between the large component surface and the point-taking tool is Q′ i (R u cosθ i ,Z′ i ), where θ i =(i-1)θ, i is the number of points, i≤N, to ensure that the range of points covers the entire processing area of the left half of the large component surface, Z ′ i The contact point P ′ i Z-axis coordinate value in the machine tool coordinate system;

[0009] Step 13: Based on the N contact points Q obtained by sampling i and N contact points Q ′ i The coordinate values of the large component are fitted on the left and right surfaces respectively to obtain the surface curve function Z=f(X) of the large component in the XZ plane;

[0010] Step 14: Repeat the above steps 11-13 in several XZ planes perpendicular to the Y axis to obtain the large component surface curve function Z=f(X) corresponding to the XY plane, and obtain the large component surface function Z=f(X, Y) based on the fitting of the large component surface curve function Z=f(X) in several XZ planes.

[0011] Furthermore, the total number of sampling points N depends on the size of the large component. The larger the size of the large component, the larger the value of N is, so as to ensure that the fitted surface curve of the large component is consistent with the actual situation.

[0012] Furthermore, the total number of points N=48.

[0013] Step 2: Determine the tool travel mode.

[0014] Specifically, after obtaining the surface function of a large component, the grooves on the left and right halves of the component are machined separately. To ensure smooth chip removal, the grooves on the surface of the large component are cut half a circle and then retracted half a circle. The cutting and retracting tool paths form a fan-shaped loop trajectory.

[0015] Step 3: Cutting tool path calculation.

[0016] The entire processing process is divided into cutting processing, external bevel processing and internal bevel processing. Before formally processing the internal and external bevels, large components need to be cut vertically first.

[0017] like Figure 6 As shown in , the contact point between the tool and the surface of the large component (i.e., the cutting point) during actual machining is not the tool tip point, so the actual cutting point coordinates are (X, f(Xr)), where r is the tool radius. And as Figure 2 As shown in the figure, with the machining radius R and the tool radius r, the actual operating radius of the tool tip during cutting is R' = (Rr) mm. Coordinate transformation is then performed to obtain the machine tool processing code.

[0018] Step 4: Calculate the tool path for machining the outer groove.

[0019] Step 41, fitting the mid-layer function and the inner surface function of the large component:

[0020] Step 411 , deriving the large component surface curve function Z=f(X) in the XZ plane to obtain the normal direction of the curve;

[0021] Step 412: Q obtained by sampling the points in step 1 i ,Q ′ i The point set is displaced inward along the corresponding normal direction by RM and RI to obtain the point set used to fit the mid-layer curve and the inner surface curve of the large component.

[0022] Step 413, respectively fitting the point sets of the mid-surface curve and the inner surface curve of the large component to obtain the mid-surface curve function Z of the large component in the XZ plane. RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X),

[0023] Step 414, repeat the above steps 411-413 in several XZ planes perpendicular to the Y axis to obtain the surface curve function Z of the large component in the corresponding XY plane. RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X), based on the surface curve function Z of several large components in the XZ plane RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X), fitting to obtain the mid-level function Z of large components RM =f RM (X, Y) and the inner surface function Z of large components RI =f RI (X,Y).

[0024] Step 42: Calculate the outer groove tool path based on the large component surface function and the large component mid-level function.

[0025] like Figure 8 As shown in the figure, the intersection line between the surface of the large component and the intersecting cylindrical surface with a radius of R is recorded as the "surface line", and the intersection line between the surface of the large component and the cylindrical surface with a radius of R is recorded as the "surface line". u The intersection line of the outer bevel and the cylindrical surface is recorded as the "outer bevel line". The intersection line of the middle surface of the large component and the intersecting cylindrical surface with a radius of R is recorded as the "middle surface line".

[0026] The intersecting cylindrical surfaces are projected into the XY plane as concentric circles. In the polar coordinate system, the polar coordinate expressions of the "surface line", "outer slope line" and "middle surface line" are as follows:

[0027] Surface Line expression:

[0028] "Outer Slope Line" expression:

[0029] "Mid-plane line" expression:

[0030] like Figure 1 、 8 As shown, in the XY projection plane, let the point where the edge of the intersection line projection center corresponding to the angle α intersects the projection of the "outer slope line" and the "middle surface line", and the corresponding points on it are C and B respectively.

[0031] C=(R u cos(α),R u sin(α),f(R u cos(α), R u sin(α))),

[0032] B=(Rcos(α),Rsin(α),f RM (Rcos(α), Rsin(α))),

[0033] like Figure 8 As shown, remember along the outer slope direction: The tangential direction of the outer slope line point C is:

[0034]

[0035] Then the tool axis direction is taken as:

[0036]

[0037] This ensures that the tool is perpendicular to the outer groove surface.

[0038] Step 43, get points C, B and Afterwards, The plane passing through points B and C in the normal direction intersects the "surface line" at point A, which is the tool entry point when cutting the outer groove, that is, the tool tip point. Take out section ABC and enlarge it, as shown in the figure below. Figure 9 As shown. The tool axis direction is Ensure perpendicularity to line BC. The tool axis intersects line BC at point D, and the tool feeds along line AD, that is, along the direction of the tool axis. If the tool diameter cannot cover the area to be machined in one go, the tool position can be offset left or right along line BC to ensure that the area to be machined is fully machined. Once the tool tip point and tool axis direction are determined and coordinate transformation is performed, the machine tool processing code is generated.

[0039] Step 5: Calculation of tool path for internal groove machining

[0040] Calculate the inner groove tool path based on the inner surface function of large components and the middle surface function of large components:

[0041] like Figure 10 As shown, suppose that the inner surface of the large component displaced inward RI along the corresponding normal direction is d The intersection line of the intersecting cylindrical surfaces of is recorded as the "inner groove line", and the intersection line of the inner surface of the large component and the intersecting cylindrical surface of radius R is recorded as the "inner surface line". The projection of each intersecting cylindrical surface into the XY plane is a concentric circle, and the spatial expression of the "inner groove line" and "inner surface line" in polar coordinates is:

[0042] "Inner groove line" expression:

[0043] "Inner Surface Line" expression:

[0044] like Figure 10 As shown, in the XY projection plane, set the point where the edge corresponding to the angle α′ passing through the center of the intersection line intersects the projection of the "inner groove line" and the "middle surface line", and the corresponding points on it are C′ and A′ respectively.

[0045] C′=(R d cos(α′),R d sin(α′),f RI (R d cos(α′), R d sin(α′))),

[0046] A′=(Rcos(α′),Rsin(α′),f RI (Rcos(α′),Rsin(α′))),

[0047] Remember to follow the inner slope direction:

[0048]

[0049] Set to the tool axis direction when cutting the inner groove.

[0050] The tangential direction of the groove at point A′ is:

[0051] Get an A ′ , point C′ and Afterwards, Point A is the normal direction ′ , the plane of C′ intersects the “inner surface line” at point B′.

[0052] like Figure 11 As shown, take out the cross section A'B'C' and enlarge it. If the tool is fed with point A' as the tool tip, the inner groove will be destroyed, so the tool offset is required. Figure 11 ,

[0053] Then the tool offset direction is:

[0054]

[0055] Move the tool tip point along the tool offset direction The radius of the translation tool is r = 16mm, so that the inner groove will not be damaged. The tool tip point at this time is recorded as D'. When cutting, the tool takes point D' as the entry point and moves along the tool axis. Feed.

[0056] By performing coordinate transformation on the tool tip point and the tool axis direction, the machine tool processing code can be obtained.

[0057] Furthermore, when the cross section of a large component is set to a uniform cross section, the surface curve function of the large component in each XZ plane is fitted as Z = f(X), and the surface curve function of the large component in each XZ plane is Z RM =f RM (X), the inner surface curve function of large components is Z RI =f RI (X).

[0058] At this time, the intersection line between the middle layer of the large component and the intersecting cylindrical surface with a radius of R is recorded as the "middle layer line". According to the projection of each intersecting cylindrical surface into the XY plane as a concentric circle, the spatial expression of the "surface line", "outer slope line" and "middle layer line" in polar coordinates can be obtained. The expression is as follows:

[0059] Surface Line expression:

[0060] "Outer Slope Line" expression:

[0061] "Mid-plane line" expression:

[0062] like Figure 1 、 8 As shown, in the XY projection plane, let the edge of the intersection line with the angle α at the center point of the intersection intersect the projection of the "outer slope line" and the "middle surface line", and the corresponding points on it are C and B respectively.

[0063] C=(R u cos(α),R u sin(α),f(R u cos(α))),

[0064] B=(Rcos(α),Rsin(α),f RM (Rcos(α))),

[0065] like Figure 8 As shown, remember along the outer slope direction: The tangential direction of the outer slope line point C is:

[0066]

[0067] Assume the tool axis direction is:

[0068]

[0069] This ensures that the tool is perpendicular to the outer groove surface.

[0070] Get points C, B and Afterwards, The plane passing through points B and C in the normal direction intersects the "surface line" at point A, which is the tool entry point when cutting the outer groove, that is, the tool tip point. Take out section ABC and enlarge it, as shown in the figure below. Figure 9 As shown. The tool axis method is Ensure perpendicularity to line BC. The tool axis intersects line BC at point D, and the tool feeds along line AD, that is, along the direction of the tool axis. If the tool diameter cannot cover the area to be machined in one go, the tool position can be offset left or right along line BC to ensure that the area to be machined is fully machined. Once the tool tip point and tool axis direction are determined and coordinate transformation is performed, the machine tool processing code is generated.

[0071] like Figure 10 As shown, assume that the inner surface of the large component displaced inward along the corresponding normal direction RI and the inner groove radius are R dThe intersection line of the intersecting cylindrical surfaces is recorded as the "inner groove line", and the intersection line of the inner surface of the large component and the R-intersecting cylindrical surface is recorded as the "inner surface line". The projection of each intersecting cylindrical surface into the XY plane is a concentric circle. The spatial expression of the "inner groove line" and "inner surface line" in polar coordinates is:

[0072] "Inner groove line" expression:

[0073] "Inner Surface Line" expression:

[0074] In the XY projection plane, set the point where the edge of the intersection line corresponding to the angle α′ intersects the projection lines of the "inner slope line" and the "middle surface line", and the corresponding points on it are C′ and A′ respectively.

[0075] C′=(R d cos(α′),R d sin(α′),f RI (R d cos(α′))),

[0076] A′=(Rcos(α′),Rsin(α′),f RM (Rcos(α′))),

[0077] Remember to follow the inner slope direction:

[0078]

[0079] Set to the tool axis direction when cutting the inner groove.

[0080] The tangential direction of the groove at point A′ is:

[0081]

[0082] Get an A ′ , point C′ and Afterwards, Point A is the normal direction ′ , the plane of C' intersects the "inner surface line" at point B'. Figure 11 As shown, take out the cross section A'B'C' and enlarge it. If the tool is fed with point A' as the tool tip, the inner groove will be destroyed, so the tool offset is required. Figure 11 ,

[0083] Then the tool offset direction is:

[0084]

[0085] Move the tool tip point along the tool offset direction The radius of the translation tool is r = 16mm, so that the inner groove will not be damaged. The tool tip point at this time is recorded as D'. When cutting, the tool takes point D' as the entry point and moves along the tool axis. Feed.

[0086] The tool tip point and the tool axis direction are transformed into coordinates to obtain the machine tool processing code.

[0087] The present invention sets the length direction of a large component as the Y axis, cuts the cross section of the large component along several XZ planes parallel to the Y axis, and contacts the surface of the large component with a machine tool tool in the XZ plane. The surface of the large component is sampled to obtain a point set, and the point set is used to fit the surface curve function Z=f(X) of the large component in several XZ planes, the surface curve function Z of the large component in the middle layer, and the surface curve function Z of the large component in the middle layer. RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X), based on the surface curve function Z=f(X,Y) of the large component in the XZ plane, the surface curve function Z RM =f RM (X, Y) and the inner surface curve function Z of large components RI =f RI (X, Y), fitting obtains the surface function of the large component surface within the processing range in three-dimensional space, the surface function of the middle layer of the large component and the surface function of the inner surface of the large component, and then the intersection line between the outer surface of the large component and the cylindrical surface with a processing radius of R is recorded as the "surface line", and the intersection line between the outer surface of the large component and the outer groove radius of R is recorded as the "surface line". u The intersection line of the intersecting cylindrical surfaces is recorded as the "outer groove line", and the inner surface of the large component and the radius R d The intersection line of the intersecting cylindrical surfaces is recorded as the "inner groove line", the intersection line of the inner surface of the large component and the R-intersecting cylindrical surface is recorded as the "inner surface line", and the intersection line of the middle surface of the large component and the R-intersecting cylindrical surface is recorded as the "middle surface line". According to the expression of the above lines in the polar coordinate system, the corresponding large component surface function, large component middle surface function and large component inner surface function formula are obtained, and then the conversion relationship between polar coordinates and right-angle seats is used to obtain the tool path for machining the outer groove and inner groove of the large component. The tool tip point and the tool axis direction are transformed to obtain the machine tool processing code, which ensures that the outer groove line and the inner groove line are continuous and smooth. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 This is a schematic diagram of the right half of the large component and its upslope.

[0089] Figure 2 Schematic diagram of fitting points.

[0090] Figure 3 This is a schematic diagram of the point selection tool.

[0091] Figure 4 Schematic diagram of tool movement.

[0092] Figure 5 Schematic diagram of the groove processing process.

[0093] Figure 6 Schematic diagram for cutting tool path calculation.

[0094] Figure 7 Schematic diagram of the curve expression of the surface, middle layer and inner surface.

[0095] Figure 8 Schematic diagram of external bevel tool path calculation.

[0096] Figure 9 Schematic diagram of external bevel cutting feed.

[0097] Figure 10 This is a schematic diagram of the inner bevel tool path calculation.

[0098] Figure 11 This is an illustration of the inner groove cutting feed. DETAILED DESCRIPTION

[0099] The present invention will be further described below with reference to the accompanying drawings.

[0100] Since the surface of the large component is not a standard cylindrical surface, the relative position of the machine tool reference plane and the large component surface is difficult to determine. The large component circumference point method is used to determine the position of the large component surface relative to the machine tool reference plane, and the projection curve of the large component surface on the large component cross section is expressed in the machine tool coordinate system for tool path calculation.

[0101] A coordinate system is established with the length direction of the large component as the Y coordinate axis direction, the horizontal direction as the X coordinate axis direction, the cross section of the large component parallel to the XZ plane, and the Z coordinate axis coaxial with the axis of each cylindrical surface intersecting the surface of the large component.

[0102] Example 1

[0103] The method for calculating the tool path for machining the groove of a large component surface of the present invention specifically comprises the following steps:

[0104] Step 1: Take points on the circumferential surface of the large component to fit the surface curve of the large component.

[0105] When cutting the surface of a large component with a tool, the edge of the tool contacts the large component, such as Figure 2 The groove radius R outside the point radius shown u=1056mm is the sampling point radius, and a total of 48 points are taken, and a point is taken every θ=3.75°, where 3.75°*48=180°, covering the processing area of the right half of the large component, and the distance between the surface of the large component and the machine tool reference plane is obtained, which is the Z coordinate value of the machine tool coordinate system (the machine tool coordinate system is established as follows Figure 2 The corresponding X coordinate value is X=Rcos(n×θ), where n is the number of points taken. By fitting the obtained (X, Z) point set, the expression of the surface curve of the large component in the machine tool coordinate system can be obtained.

[0106] Specific as Figure 2-3 As shown in step 11, in the XZ plane, use the point-picking tool to touch the right half surface of the large component and record the coordinates of the tool tip point P when touching. i (θ i ,Z i ), at this time the coordinates of the contact point between the large component surface and the point-taking tool are Q i (R u cosθ i ,Z i ), where θ i =(i-1)θ, i is the number of points, i≤N, to ensure that the range of points covers the entire processing area of the right half of the large component surface, Z i The tool tip point P at contact i The Z-axis coordinate value in the machine tool coordinate system, where R u is the radius of the intersecting cylindrical surface of the outer groove, θ is the angle of the point interval, and θ*N=180°;

[0107] Step 12: Use the point-picking tool to touch the left half of the large component surface and record the coordinates of the tool tip point P when touching. ′ i (θ i ,Z′ i ), at this time, the coordinate of the contact point between the large component surface and the point-taking tool is Q′ i (R u cosθ i ,Z′ i ), where θ i

[0108] =(i-1)θ, i is the number of points, i≤N, to ensure that the range of points covers the entire processing area of the left half of the large component surface, Z ′ i The contact point P ′ i Z-axis coordinate value in the machine tool coordinate system;

[0109] Step 13: Based on the N contact points Q obtained by sampling i and N contact points Q′ i The coordinate values of the large component are fitted on the left and right surfaces respectively to obtain the surface curve function Z=f(X) of the large component in the XZ plane;

[0110] Step 14: Repeat the above steps 11-13 in several XZ planes perpendicular to the Y axis to obtain the large component surface curve function Z=f(X) corresponding to the XY plane, and obtain the large component surface function Z=f(X, Y) based on the fitting of the large component surface curve function Z=f(X) in several XZ planes.

[0111] Furthermore, the total number of points N depends on the size of the large component. The larger the size of the large component, the larger the N value, so as to ensure that the surface curve of the large component obtained by fitting is consistent with the actual situation.

[0112] Step 2: Determine the tool travel mode.

[0113] After obtaining the curve expression of the large component surface, the grooves on the left and right halves of the large component are processed separately. In order to remove chips smoothly, the large component surface is cut half a circle and then retracted half a circle. The cutting tool path and the retracting tool path form a fan-shaped cycle trajectory, such as Figure 4 shown.

[0114] Step 3: Cutting tool path calculation.

[0115] like Figure 5 As shown, the entire processing process is divided into cutting processing, outer bevel processing and inner bevel processing. Before the formal processing of the inner bevel, the large component needs to be cut vertically first.

[0116] like Figure 5-6 As shown in , the contact point between the tool and the surface of the large component (i.e., the cutting point) during actual machining is not the tool tip point, so the actual cutting point coordinates are (X, f(Xr)), where r is the tool radius. And as Figure 2 As shown in the figure, taking the machining radius R = 1000mm as an example, the tool radius r = 16mm, and the actual operating radius of the tool tip during cutting is R' = 984mm. Coordinate transformation is then performed to obtain the machine tool machining code.

[0117] Step 4: Calculate the tool path for external bevel machining

[0118] Step 41, fitting the mid-layer function and the inner surface function of the large component:

[0119] Step 411: Derivative the surface curve function Z=f(X) of the large component in the XZ plane to obtain the normal direction of the curve, such as Figure 7 As shown;

[0120] Step 412: Q obtained by sampling the points in step 1i ,Q ′ i The point set is displaced inward along the corresponding normal direction by RM and RI to obtain the point set used to fit the mid-layer curve and the inner surface curve of the large component.

[0121] Step 413, respectively fitting the point sets of the mid-surface curve and the inner surface curve of the large component to obtain the mid-surface curve function Z of the large component in the XZ plane. RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X),

[0122] Step 414, repeat the above steps 411-413 in several XZ planes perpendicular to the Y axis to obtain the surface curve function Z of the large component in the corresponding XY plane. RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X), based on the surface curve function Z of several large components in the XZ plane RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X), fitting to obtain the mid-level function Z of large components RM =f RM (X, Y) and the inner surface function Z of large components RI =f RI (X,Y).

[0123] Step 42: Calculate the outer groove tool path based on the large component surface function and the large component mid-level function.

[0124] like Figure 8 As shown in the figure, the intersection line between the surface of the large component and the cylindrical surface with a processing radius of R = 1000mm is recorded as the "surface line", and the intersection line between the surface of the large component and the outer groove radius is R u =1056mm The intersection line of the intersecting cylindrical surfaces is recorded as the "outer slope line".

[0125] The intersection line of the middle surface of the large component RM = 45mm and the cylindrical surface R = 1000mm is recorded as the "middle surface line". After obtaining its expression,

[0126] The intersecting cylindrical surfaces are projected onto the XOY plane as concentric circles. In the polar coordinate system, the polar coordinate expressions of the "surface line", "outer slope line" and "middle surface line" are as follows:

[0127] Surface Line expression:

[0128] "Outer Slope Line" expression:

[0129] "Mid-plane line" expression:

[0130] like Figure 1 、 8 As shown, let the point where the edge of the intersection line projection center corresponding to the angle α intersects the projection line of the "outer slope line" and the "middle surface line", and the corresponding points on it are C and B respectively. Then

[0131] C=(R u cos(α),R u sin(α),f(R u cos(α), R u sin(α))),

[0132] B=(Rcos(α),Rsin(α),f RM (Rcos(α), Rsin(α))),

[0133] like Figure 8 As shown, remember along the outer slope direction: The tangential direction of the outer slope line point C is:

[0134]

[0135] Then the tool axis direction is taken as:

[0136]

[0137] This ensures that the tool is perpendicular to the outer groove surface.

[0138] Step 43, get points C, B and Afterwards, The plane passing through points B and C in the normal direction intersects the "surface line" at point A, which is the tool entry point when cutting the outer groove, that is, the tool tip point. Take out section ABC and enlarge it, as shown in the figure below. Figure 9 As shown. The tool axis direction is Ensure perpendicularity to line BC, with the tool axis intersecting line BC at point D, and the tool feeds along line AD. If the tool diameter cannot cover the area to be machined in one go, the tool position can be offset left or right along line BC to ensure complete machining of the area to be machined. Once the tool tip point and tool axis direction are determined and coordinate transformation is performed, the machine tool processing code is generated.

[0139] Step 5: Calculation of tool path for internal groove machining

[0140] Calculate the inner groove tool path based on the inner surface curve function of large components and the middle layer curve function of large components:

[0141] like Figure 10 As shown, suppose that the inner surface of the large component displaced inward RI along the corresponding normal direction is d The intersection line of the intersecting cylindrical surfaces of is recorded as the "inner groove line", and the intersection line of the inner surface of the large component and the intersecting cylindrical surface of radius R is recorded as the "inner surface line". The projection of each intersecting cylindrical surface into the XY plane is a concentric circle, and the spatial expression of the "inner groove line" and "inner surface line" in polar coordinates is:

[0142] "Inner groove line" expression:

[0143] "Inner Surface Line" expression:

[0144] like Figure 10 As shown, in the XY plane, set the point where the edge of the intersection line corresponding to the angle α′ intersects the projection line of the "inner slope line" and the "middle surface line", and the corresponding points on it are C′ and A′ respectively.

[0145] C′=(R d cos(α′),R d sin(α′),f RI (R d cos(α′), R d sin(α′))),

[0146] A′=(Rcos(α′),Rsin(α′),f RI (Rcos(α′),Rsin(α′))),

[0147] Remember to follow the inner slope direction:

[0148]

[0149] Set to the tool axis direction when cutting the inner groove.

[0150] The tangential direction of the groove at point A′ is:

[0151]

[0152] Get an A ′ , point C′ and Afterwards, Point A is the normal direction ′ , the plane of C′ intersects the “inner surface line” at point B′.

[0153] like Figure 11As shown, take out the section A′B′C′ and enlarge it. If the tool feeds with point A′ as the tool tip, the inner groove will be destroyed, so the tool offset is required.

[0154] Then the tool offset direction is:

[0155]

[0156] Move the tool tip point along the tool offset direction The radius of the translation tool is r = 16mm, so that the inner groove will not be damaged. The tool tip point at this time is recorded as D'. When cutting, the tool takes point D' as the entry point and moves along the tool axis. Feed.

[0157] By performing coordinate transformation on the tool tip point and the tool axis direction, the machine tool processing code can be obtained.

[0158] When the cross section of a large component is set to a uniform cross section, the surface curve function Z=f(X) of the large component in each XZ plane is fitted to be the same, and the surface curve function Z RM =f RM (X) is the same, the inner surface curve function of the large component is Z RI =f RI (X)Same.

[0159] At this time, the intersection line between the middle surface of the large component and the intersecting cylindrical surface with a radius of R is recorded as the "middle surface line". After obtaining its expression, the intersecting cylindrical surfaces are projected into the XY plane as concentric circles, and the spatial expressions of the "surface line", "outer slope line" and "middle surface line" in polar coordinates can be obtained. The expression is as follows:

[0160] Surface Line expression:

[0161] "Outer Slope Line" expression:

[0162] "Mid-layer line" expression:

[0163] like Figure 1 、 8 As shown, in the XY plane, let the point where the edge of the intersection line with the angle α intersects the projection line of the "outer slope line" and the "middle surface line" at the center of the intersection line, and the corresponding points on it are C and B respectively.

[0164] C=(R u cos(α),R u sin(α),f(R u cos(α))),

[0165] B=(Rcos(α),Rsin(α),fRM (Rcos(α))),

[0166] like Figure 8 As shown, remember along the outer slope direction: The tangential direction of the outer slope line point C is:

[0167]

[0168] Then the tool axis direction is:

[0169]

[0170] This ensures that the tool is perpendicular to the outer groove surface.

[0171] Get points C, B and Afterwards, The plane passing through points B and C in the normal direction intersects the "surface line" at point A, which is the tool entry point when cutting the outer groove, that is, the tool tip point. Take out section ABC and enlarge it, as shown in the figure below. Figure 9 As shown. The tool axis method is Ensure perpendicularity to line BC, with the tool axis intersecting line BC at point D, and the tool feeds along line AD. If the tool diameter cannot cover the area to be machined in one go, the tool position can be offset left or right along line BC to ensure complete machining of the area to be machined. Once the tool tip point and tool axis direction are determined and coordinate transformation is performed, the machine tool processing code is generated.

[0172] like Figure 10 As shown, assume that the inner surface of the large component displaced inward along the corresponding normal direction RI and the inner groove radius are R d The intersection line of the intersecting cylindrical surfaces is recorded as the "inner groove line", and the intersection line of the inner surface of the large component and the R-intersecting cylindrical surface is recorded as the "inner surface line". The projection of each intersecting cylindrical surface into the XY plane is a concentric circle. The spatial expression of the "inner groove line" and "inner surface line" in polar coordinates is:

[0173] "Inner groove line" expression:

[0174] "Inner Surface Line" expression:

[0175] On the XY plane, let the point where the edge of the intersection line corresponding to the angle α′ intersects the projection line of the "inner slope line" and the "middle surface line", and the corresponding points on it are C′ and A′ respectively.

[0176] C′=(R d cos(α′),R d sin(α′),f RI (R d cos(α′))),

[0177] A′=(Rcos(α′),Rsin(α′),f RM (Rcos(α′))),

[0178] Remember to follow the inner slope direction:

[0179]

[0180] Set to the tool axis direction when cutting the inner groove.

[0181] The tangential direction of the groove at point A′ is:

[0182]

[0183] Get an A ′ , point C′ and Afterwards, Point A is the normal direction ′ , the plane of C' intersects the "inner surface line" at point B'. Figure 11 As shown, take out the cross section A'B'C' and enlarge it. If the tool is fed with point A' as the tool tip, the inner groove will be destroyed, so the tool must be biased. Figure 11 ,

[0184] Then the tool offset direction is:

[0185]

[0186] Move the tool tip point along the tool offset direction The radius of the translation tool is r = 16mm, so that the inner groove will not be damaged. The tool tip point at this time is recorded as D'. When cutting, the tool takes point D' as the entry point and moves along the tool axis. Feed.

[0187] The tool tip point and the tool axis direction are transformed into coordinates to obtain the machine tool processing code.

[0188] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0189] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referenced to each other.

[0190] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for calculating a tool path for machining a groove on a large component surface, wherein the length of the large component is defined as the Y coordinate axis, the horizontal direction is defined as the X coordinate axis, the cross section of the large component is parallel to the XZ plane, and the Z coordinate axis is coaxial with the axes of the cylindrical surfaces intersecting the large component surface; characterized by: The following steps are involved: Step 1: Take points on the circumferential surface of the large component to fit the surface function Z=f(X, Y) of the large component; Step 2: Determine the tool travel mode; Step 3: Calculate the cutting tool path; Step 4: Calculate the tool path for machining the outer groove; Step 41: Fitting to obtain the mid-level function Z of the large component RM =f RM (X, Y) and the inner surface function Z of large components RI =f RI (X,Y); Step 42, calculating the outer bevel tool path based on the mid-surface function of the large component and the inner surface function of the large component; The intersection line between the surface of the large component and the intersecting cylindrical surface of radius R is recorded as "surface line". u The intersection line of the outer bevel and the cylindrical surface is recorded as the "outer bevel line", and the intersection line of the middle surface of the large component and the intersecting cylindrical surface of radius R is recorded as the "middle surface line". The projection of each intersecting cylindrical surface into the XY plane is a concentric circle. In the polar coordinate system, the expressions of "surface line", "outer bevel line" and "middle surface line" are as follows: Surface Line Expression "Outer Slope Line" Expression "Mid-level line" expression In the XY projection plane, let the point where the edge of the intersection line projection center corresponding to the angle α intersects the projection line of the "outer slope line" and the "middle surface line", and the corresponding points on it are C and B respectively, then C=(R u cos(α),R u sin(α),f(R u cos(α), R u sin(a))), B=(Rcos(α),Rsin(α),f RM (Rcos(α), Rsin(α))), Remember to follow the direction of the outer slope The tangential direction of point C on the outer slope line is: Assume the tool axis direction is Ensure that the tool is perpendicular to the outer bevel surface; Step 43, The plane passing through points B and C intersects the "surface line" at point A, which is the tool feed point and tool tip point when cutting the outer groove. The tool tip point position and tool axis direction are obtained, and coordinate transformation is performed to obtain the machine tool processing code. Step 5: Calculate the tool path for internal groove machining.

2. A tool path calculation method for large component surface groove machining according to claim 1, characterized in that: The step 1 specifically includes the following steps: Step 11: In the XZ plane, use the point-picking tool to touch the right half of the surface of the large component and record the coordinates of the tool tip point P when the point-picking tool is in contact. i (θ i ,Z i ), at this time, the coordinate of the contact point between the large component surface and the point-taking tool is Q i (R u cosθ i ,Z i ), where θ i =(i-1)θ, i is the number of points, i≤N, to ensure that the range of points covers the entire processing area of the right half of the large component surface, Z i The tool tip point P at contact i The Z-axis coordinate value in the machine tool coordinate system, where R u is the radius of the cylindrical surface where the outer groove intersects, θ is the angle between the points, and θ*N=180°, Step 12: Use the point-picking tool to touch the left half of the large component surface and record the coordinates of the tool tip point P' at the time of contact. i (θ i ,Z′ i ), at this time, the coordinate of the contact point between the large component surface and the point-taking tool is Q′ i (R u cosθ i ,Z′ i ), where θ i =(i-1)θ, i is the number of points, i≤N, to ensure that the range of points covers the entire processing area of the left half of the large component surface, Z′ i is the contact point P′ i Z-axis coordinate value in the machine tool coordinate system; Step 13: Based on the N contact points Q obtained by sampling i and N contact points Q′ i The coordinate values of the large component are fitted on the left and right surfaces respectively to obtain the surface curve function Z=f(X) of the large component in the XZ plane; Step 14: Repeat steps 11-13 above in several XZ planes perpendicular to the Y axis to obtain the surface curve function Z=f(X) of the large component in the corresponding XY plane, and obtain the surface function Z=f(X, Y) of the large component based on the fitting of the surface curve function Z=f(X) of the large component in the several XZ planes.

3. The method for calculating a tool path for machining a large component surface groove according to claim 2, wherein: The total number of sampling points N depends on the size of the large component. The larger the size of the large component, the larger the value of N is, to ensure that the fitted surface curve of the large component is consistent with the actual situation.

4. The method for calculating a tool path for machining a large component surface groove according to claim 3, wherein: The step 2 specifically includes the following contents: after obtaining the surface function of the large component, the grooves on the left and right halves of the surface of the large component are processed separately; the grooves on the surface of the large component are cut half a circle and then retracted half a circle, and the cutting tool path and the retracting tool path form a fan-shaped cycle trajectory.

5. A tool path calculation method for machining a large component surface groove according to any one of claims 1 to 4, characterized in that: The step 41 includes: Step 411 , deriving the large component surface curve function Z=f(X) in the XZ plane to obtain the normal direction of the curve; Step 412: Q obtained by sampling the points in step 1 i ,Q′ i The point set is displaced inward along the corresponding normal direction by RM and RI to obtain the point set used to fit the mid-layer curve and the inner surface curve of the large component. Step 413, respectively fitting the point sets of the mid-surface curve and the inner surface curve of the large component to obtain the mid-surface curve function Z of the large component in the XZ plane. RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X), Step 414, repeat the above steps 411-413 in several XZ planes perpendicular to the Y axis to obtain the surface curve function Z of the large component in the corresponding XY plane. RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X), based on the surface curve function Z of several large components in the XZ plane RM =f RM (X) and the inner surface curve function Z of large components RI =f RI (X), fitting to obtain the mid-level function Z of large components RM =f RM (X, Y) and the inner surface function Z of large components RI =f RI (X,Y).

6. A tool path calculation method for large component surface groove machining according to claim 5, characterized in that: The step 5 comprises: Calculate the inner groove tool path based on the inner surface function of large components and the middle surface function of large components: Assume that the inner surface of the large component displaced inward RI along the corresponding normal direction and the radius R d The intersection line of the intersecting cylindrical surfaces of radius R is recorded as the "inner groove line", and the intersection line of the inner surface of the large component and the intersecting cylindrical surface of radius R is recorded as the "inner surface line". The projection of each intersecting cylindrical surface into the XY plane is a concentric circle. The spatial expression of the "inner groove line" and "inner surface line" in polar coordinates is: "Inner groove line" expression: "Inner Surface Line" expression: In the XY projection plane, set the point where the edge corresponding to the angle α′ passing through the center of the intersection line intersects the projection of the "inner groove line" and the "middle surface line", and the corresponding points on it are C′ and A′ respectively; C′=(R d cos(α′),R d sin(α′),f RI (R d cos(α′), R d sin(α′))), A′=(Rcos(α′),Rsin(α′),f RI (Rcos(α′), Rsin(α′))), Remember to follow the inner slope direction: Set as the tool axis direction when cutting the inner groove; The tangential direction of the groove at point A′ is: Get points A', C' and Afterwards, The plane passing through points A′ and C′ in the normal direction intersects the "inner surface line" at point B′; In the section A′B′C′, if the tool is fed with point A′ as the tool tip, the inner groove will be destroyed, so the tool offset is required; Then the tool offset direction is: Move the tool tip point along the tool offset direction The tool radius r is translated so that the inner groove will not be damaged. The tool tip point at this time is recorded as D'. When cutting, the tool takes point D' as the entry point and moves along the tool axis. feed; By performing coordinate transformation on the tool tip point and the tool axis direction, the machine tool processing code can be obtained.

7. The method for calculating tool paths for machining grooves on large component surfaces according to claim 1, wherein: If the cross section of a large component is set to a uniform cross section, the surface curve function of the large component in each XZ plane is fitted to Z = f(X), and the surface curve function of the large component is Z RM =f RM (X), the inner surface curve function of large components is Z RI =f RI (X); At this time, the intersection line between the middle layer of the large component and the intersecting cylindrical surface with a radius of R is recorded as the "middle layer line". According to the projection of each intersecting cylindrical surface into the XY plane as concentric circles, the spatial expression of the "surface line", "outer slope line" and "middle layer line" in polar coordinates is as follows: "Surface line" expression: "Outer slope line" expression: "Mid-level line" expression: In the XY projection plane, let the point where the edge of the intersection line with the angle α intersects the projection of the "outer slope line" and the "middle surface line" and the corresponding points on it are C and B respectively, then C=(R u cos(α),R u sin(α),f(R u cos(α))), B=(Rcos(α),Rsin(α),f RM (Rcos(α))), Remember to follow the outer slope direction: The tangential direction of the outer slope line point C is: Then the tool axis direction is: This ensures that the tool is perpendicular to the outer bevel surface; Get points C, B and Afterwards, The plane passing through points B and C in the normal direction intersects the "surface line" at point A, which is the tool feed point when cutting the outer groove, that is, the tool tip point; the tool axis method is Ensure that it is perpendicular to the straight line BC, the tool axis intersects the straight line BC at point D, and the tool feeds along the straight line AD; when the tool diameter cannot cover the area to be processed at one time, the tool position can be offset left and right along the straight line BC to ensure that the area to be processed is completely processed; obtain the tool tip point and the tool axis direction, and then perform coordinate transformation to obtain the machine tool processing code.

8. The method for calculating tool paths for machining grooves on large component surfaces according to claim 7, wherein: The step 5 specifically includes the following steps: Calculate the inner groove tool path based on the inner surface curve function of large components and the middle layer curve function of large components: Assume that the inner surface of the large component displaced inward RI along the corresponding normal direction and the inner groove radius are R d The intersection line of the intersecting cylindrical surfaces is recorded as the "inner groove line", and the intersection line between the inner surface of the large component and the R-intersecting cylindrical surface is recorded as the "inner surface line". The spatial expressions of the "inner groove line" and "inner surface line" in polar coordinates are: "Inner groove line" expression: "Inner Surface Line" expression: In the XY projection plane, set the point where the edge corresponding to the angle α′ passing through the center of the intersection line intersects the projection of the "inner groove line" and the "middle surface line", and the corresponding points on it are C′ and A′ respectively. C′=(R d cos(α′),R d sin(α′),f RI (R d cos(α′))) A′=(Rcos(α′),Rsin(α′),f RM (Rcos(α′))) Remember to follow the inner slope direction: Set as the tool axis direction when cutting the inner groove; The tangential direction of the groove at point A' is: Get points A', C' and Afterwards, The plane passing through points A′ and C′ in the normal direction intersects the "inner surface line" at point B′; In the section A′B′C′, if the tool is fed with point A′ as the tool tip, the inner groove will be destroyed, so the tool offset is required; Then the tool offset direction is: Move the tool tip point along the tool offset direction The tool radius r is translated so that the inner groove will not be damaged. The tool tip point at this time is recorded as D'. When cutting, the tool takes point D' as the entry point and moves along the tool axis. feed; By performing coordinate transformation on the tool tip point and the tool axis direction, the machine tool processing code can be obtained.

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