System and method for calculating common normal of rotor in oil pump and medium

Abstract

The invention discloses an oil pump inner rotor common normal calculation system and method and a medium, and belongs to the technical field of oil pump rotor aided design application. The system comprises a rotor parameterization design module and a data storage module, the rotor parameterization design module is used for drawing the tooth profile of the inner rotor, and then the common normal of the inner rotor is calculated through tooth profile image recognition processing. According to the method, the problems of high skill requirements on designers, tedious calculation process, low efficiency and high cost in oil pump rotor common normal calculation are solved; after the tooth profile is drawn through the system, point coordinates are recognized through a computer image, the common normal distance is calculated, and the system and method are high in practicability and suitable for being applied to oil pump rotor product design and common normal design and detection related fields of mold manufacturers and product manufacturing manufacturers; and the actual requirements in production and design can be completely met.

Description

Technical Field

[0001] The invention belongs to the technical field of auxiliary design application of oil pump rotors, and in particular relates to a system, method and medium for calculating the common normal line of an inner rotor of an oil pump. Background Art

[0002] Regarding the calculation and measurement of the normal lines of oil pump rotor molds and products, the existing technology has strict requirements on their normal lines. In the past, a fast and effective method for calculating the normal lines was not mastered, and the normal lines of oil pump rotor molds and products could not be calibrated and evaluated quickly and effectively, resulting in a certain degree of blindness in production.

[0003] In current practical applications, common methods for calculating common normals include: first, formula calculation method; second, CAD tangent-assisted surveying method. The disadvantages of the above two design methods are as follows:

[0004] (1) The formula calculation method requires designers to have high theoretical mathematical derivation capabilities

[0005] Reason: The calculation method of the common normal line formula of the oil pump rotor first requires the designer to have a good understanding of the oil pump rotor, that is, the formation principle of the short-amplitude epicycloid inner equidistant curve; secondly, it requires mathematical deduction ability, which requires the use of the insertion method, cycloid parameter equation, and tangent equation. Only after this series of rigorous mathematical deductions can the common normal line distance L of the oil pump inner rotor in the X direction or Y direction be calculated. The whole derivation process is extremely complicated, which requires a high level of theoretical mathematical derivation ability of the designer, thus limiting its promotion and practicality.

[0006] (2) CAD tangent-assisted surveying method is inefficient

[0007] Reason: CAD tangent-assisted surveying and mapping method also requires understanding of the oil pump rotor, the principle of generating equidistant curves within the short-amplitude epicycloid, and other related contents. The cycloid parameter equation is used to calculate the (X, Y) coordinate values ​​of all points within the range of 0-360° on the theoretical tooth profile of the inner rotor, and then import them into the CAD drawing. The inner rotor tooth profile curve is automatically generated through the script function. The designer then draws the normal parallel tangents on the two outermost tooth profile curves according to the number of spans to be calculated, and measures the vertical distance Wk between the two parallel tangents, which is the constant in the X or Y direction of the rotor. Since the tooth profile is connected by multiple points and multiple line segments, the CAD tangent point capture function cannot be used to automatically draw the tangent, and it can only be magnified by the naked eye to draw the two closest parallel tangents. The whole process of this method is also complicated and cumbersome, which takes a lot of time, is inefficient, and has a certain degree of error. Summary of the invention

[0008] In view of the problems existing in the prior art mentioned in the background technology, the present invention proposes a system, method and medium for calculating the common normal line of the inner rotor of an oil pump. After the system draws the tooth profile, the computer image recognition point coordinates are used to calculate the common normal line distance. The design personnel have low skill requirements, the calculation operation process is simple and fast, the efficiency is high and the cost is low.

[0009] Technical solution: In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0010] A system for calculating the common normal of an inner rotor of an oil pump comprises a rotor parameterized design module and a data storage module. The inner rotor tooth profile is drawn by using the rotor parameterized design module, and then the calculation of the common normal of the inner rotor is realized by image recognition and processing of the tooth profile.

[0011] Preferably, the rotor parameterized design module includes a data I / O module, a tooth profile node calculation module, a tooth profile drawing module and a common normal calculation module.

[0012] Preferably, the data I / O module provides a data input interface for users to input parameter information of inner and outer rotors, which is exported and stored in a specified project file through a parameter export module, and allows users to import parameters in a specified project file at any time through a parameter import module to modify the design;

[0013] The tooth profile node calculation module receives parameter information from the data I / O module and calculates the coordinate values ​​of all nodes within the range of 0-360° of the rotor tooth profile;

[0014] The tooth profile drawing module: calls the coordinates of the nodes in the tooth profile node module and draws and displays the tooth profile graphics;

[0015] The common normal calculation module automatically calculates and draws two parallel common normal tangents based on the recognition of the drawn tooth profile graphic, and calculates the vertical distance between the two parallel tangents to obtain the common normal constant.

[0016] A method for calculating a common normal line of an inner rotor of an oil pump is implemented by using the system for calculating a common normal line of an inner rotor of an oil pump described in any of the above items, and comprises the following steps:

[0017] S1: Input the parameter information of the inner and outer rotors in advance through the data input interface and store it in a data file of a specified format;

[0018] S2: Call or load the parameters of the inner and outer rotors from the specified file, pre-calculate the relevant parameters required by the cycloid equation, and bring the relevant parameters into the cycloid equation to calculate the coordinate values ​​of all nodes within the range of 0-360° of the rotor tooth profile;

[0019] S3: Draw the tooth profile, call the node coordinate data in S2, connect the end with the line segment, draw it in the drawing area and display it;

[0020] S4: Based on the drawn tooth profile, determine the number of teeth spanned by the normal distance and whether the center is symmetrical relative to the X-axis or the Y-axis; then select the tooth profile area, and the system automatically calculates and draws two parallel normal tangents to calculate the normal constant of the inner rotor.

[0021] Preferably, in S2, the parameters of the inner and outer rotors are called or loaded from a specified file, the relevant parameters required by the cycloid equation are pre-calculated, and the relevant parameters are brought into the cycloid equation to calculate the coordinate values ​​of all nodes within the range of 0-360° of the rotor tooth profile. The specific contents are:

[0022] According to the equation group obtained by transforming the parameter equation of the inner rotor theoretical profile curve, the coordinate values ​​of each node are calculated. The formula is as follows:

[0023] theta = t × 360 × PI / 180 × Z1;

[0024] X=r×cos((1-Z2 / Z1)×theta)-e×cos(Z2 / Z1×theta);

[0025] Y=r×sin((1-Z2 / Z1)×theta)+e×sin(Z2 / Z1×theta);

[0026] Wherein, theta represents radians; t represents the introduced parameter; 0≤t≤1; X represents the node horizontal coordinate value; Y represents the node vertical coordinate value; r represents the radius of the distribution circle of the creation circle; e represents the eccentric distance of the inner and outer rotor meshing; Z1 represents the number of teeth of the inner rotor; Z2 represents the number of teeth of the outer rotor; PI represents pi.

[0027] Preferably, in S4, according to the drawn tooth profile, the number of teeth spanned by the common normal distance is determined, and whether the center is symmetrical relative to the X axis or the Y axis; then the tooth profile area is framed, and the system automatically calculates and draws two parallel common normal tangents. The specific content of calculating the common normal constant of the inner rotor is:

[0028] According to the drawn tooth profile, in the area where the parallel common normal tangent tooth profile needs to be drawn, select a rectangle. If the cross-tooth direction is symmetrical with the X-axis, the rectangle has an aspect ratio greater than 1. If the cross-tooth direction is symmetrical with the Y-axis, the rectangle has an aspect ratio less than 1. Then, by scanning the nodes row by row, find the maximum values ​​of the tooth profile in the X and Y directions in the rectangular area. The system automatically draws two parallel common normal tangents symmetrical relative to the X or Y axis according to the distance of the common normal from the cross-tooth direction.

[0029] A computer-readable storage medium is used to store a program, and when the program is executed, the steps of the method for calculating the common normal line of the inner rotor of an oil pump described in any of the above items are implemented.

[0030] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0031] (1) The present invention solves the problems of high skill requirements for designers, difficult calculation of common normals, low efficiency and high cost in the actual oil pump rotor product design stage. By using the calculation system of the present invention, novice designers can easily calculate the common normal distance corresponding to the oil pump rotor by simply inputting known parameters on the drawing, without having to spend a lot of time learning and studying the generation principle of the cycloid curve of the oil pump rotor and the related theoretical mathematical derivation ability, which greatly reduces the skill requirements for designers.

[0032] (2) The common normal line calculation of the system of the present invention is not calculated by formula, but after the system draws the tooth profile, the common normal line distance is calculated by computer image recognition point coordinates. The calculation system and method are highly practical and are particularly suitable for applications in the fields of oil pump rotor product design, mold manufacturing manufacturers, and product manufacturing manufacturers' common normal line design and detection; and can fully meet the actual needs in production and design. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0034] Figure 2 A schematic diagram of a data input / output (I / O) interface of the present invention;

[0035] Figure 3 It is a schematic diagram of the graphic display interface of the present invention;

[0036] Figure 4 A schematic diagram is drawn to show the calculation of the common normal line of the present invention;

[0037] Figure 5 It is a schematic diagram showing the display / hiding effect of the inner and outer rotors of the present invention. DETAILED DESCRIPTION

[0038] The present invention is further illustrated below in conjunction with specific examples. The examples are implemented based on the technical solutions of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0039] like Figure 1-5 As shown, the oil pump inner rotor common normal calculation system provided in this embodiment includes a rotor parameter design module and a data storage module. The rotor parameter design module includes a data I / O module, a tooth node calculation module, a tooth profile drawing module and a common normal calculation module.

[0040] Data I / O module: provides a data input interface. Designers can input the necessary information used in the design of the inner and outer rotors of the oil pump in advance and store it in a data file of a specified format through the input text box displayed on the data input interface; they can also import the parameter information of the oil pump rotor to be designed into the input interface text box through the data input interface import function (such as Figure 2 After the designer inputs the parameter information that needs to be stored in advance, click the Save Data button on the data input interface, and the data I / O module will receive and store it in the data file, which can be used for later loading, calling and modifying data.

[0041] The parameters are exported and stored in the specified project file through the parameter export module. At the same time, users can import the parameters in the specified project file at any time through the parameter import module to modify the design.

[0042] In this embodiment, the rotor includes a short-amplitude epicycloid and inner equidistant rotor, and the oil pump rotor parameter information includes oil pump inner rotor parameters and oil pump outer rotor parameters.

[0043] Tooth node calculation module: After the designer inputs or selects the parameter information of the oil pump rotor in the load data button, click the "Design" button on the data input interface, the system will pop up a new window, click the "Execute" button, the tooth node calculation module will receive the data and calculate the coordinates (X, Y) of the key nodes.

[0044] Tooth profile drawing module: calls the coordinates of the nodes in the tooth profile node module and draws and displays the tooth profile graphics;

[0045] Common normal calculation module: Based on the recognition of the drawn tooth profile graphics, it automatically calculates and draws two parallel common normal tangents, and calculates the vertical distance Wk between the two parallel tangents to obtain the common normal constant; and displays it in the graphics area.

[0046] The system supports the gear profile design of outer rotor and inner rotor products as well as the calculation of the inner rotor common normal line. Figure 3As shown in the figure, taking an inner rotor design as an example, the method and steps of using the system to draw and calculate the common normal line are demonstrated:

[0047] Step 1: Open the main program and input the design parameters of the inner and outer rotors of the oil pump:

[0048] like Figure 2 As shown in the figure, in the Data of Inner Rotor column, fill in the fields related to the inner rotor, including:

[0049] Center distance: the eccentric distance between the inner and outer rotors;

[0050] Number of teeth: the number of teeth on the inner rotor;

[0051] Outside diameter: the outer diameter of the inner rotor, i.e. the long diameter;

[0052] Inside diameter: The diameter of the hole in the inner rotor that is connected to the assembly shaft;

[0053] Width of Rotor: Inner rotor width, a necessary parameter for calculating unit displacement;

[0054] In the Data of Outer Rotor column, fill in the fields related to the outer rotor (such as Figure 2 shown):

[0055] Tooth profile radius: tooth profile radius;

[0056] Outside diameter: the outer diameter of the outer rotor, the size for assembly with the oil pump housing;

[0057] Tip clearance: The clearance between the major diameters of the inner and outer rotor teeth after the inner and outer rotor teeth are engaged;

[0058] Dedendum: outer rotor tooth root transition R arc (large diameter corner);

[0059] Step 2: Click the "SaveData" button to save the internal rotor parameters currently input into the interface to a file in the specified path through the data I / O module;

[0060] Step 3: Click the "LoadData" button to call and load the inner and outer rotor parameters in the specified path file;

[0061] Step 4: Click the "Design" button and a graphic display window will pop up (such as Figure 3As shown in the figure), then click the "Execute" button to enter the tooth node calculation module, call or load the inner and outer rotor related parameters from the specified file, and pre-calculate the related parameters required by the cycloid equation;

[0062] The calculated parameters include: inner rotor minor diameter (short diameter), inner rotor pitch circle diameter, outer rotor major diameter, outer rotor minor diameter, outer rotor pitch circle diameter, creation circle diameter, cycloid characteristic coefficient, unit displacement. After the calculation, the relevant parameters are substituted into the cycloid equation to calculate the coordinate values ​​of all nodes (X, Y) within the rotor 0-360°. The cycloid equation formula is as follows:

[0063] theta = t × 360 × PI / 180 × Z1;

[0064] X=r×cos((1-Z2 / Z1)×theta)-e×cos(Z2 / Z1×theta);

[0065] Y=r×sin((1-Z2 / Z1)×theta)+e×sin(Z2 / Z1×theta);

[0066] Wherein, theta represents radians; t represents the introduced parameter; 0≤t≤1; X represents the node horizontal coordinate value; Y represents the node vertical coordinate value; r represents the radius of the distribution circle of the creation circle; e represents the eccentric distance of the inner and outer rotor meshing; Z1 represents the number of teeth of the inner rotor; Z2 represents the number of teeth of the outer rotor; PI represents pi.

[0067] like Figure 3 As shown, the tooth profile drawing module is then used to call all the node (X, Y) coordinate data in step 2 above, connect them with line segments, draw them in the drawing area and display them. The smoothness of the curve depends on the graduation accuracy of the parameter t introduced from 0 to 360°. The main drawing code is as follows;

[0068] Dim Z1 as Integer' (define Z1 variable, number of inner rotor teeth);

[0069] Dim Z2 as Integer' (define Z2 variable, number of teeth of outer rotor);

[0070] Dim e as Double' (define e variable, meshing eccentricity);

[0071] Dim r as Double' (define r variable and create the radius of the circular distribution circle);

[0072] Dim t as Double' (define t variable and introduce parameter 0≤t≤1);

[0073] Dim theta as Double' (define theta variable, radians);

[0074] Dim X1 as Double' (define X1 variable, X value of the starting point coordinate of the line segment);

[0075] Dim Y1 as Double' (define Y1 variable, Y value of the starting point coordinate of the line segment);

[0076] Dim X2 as Double' (define X2 variable, the X value of the end point coordinate of the line segment);

[0077] Dim Y2 as Double' (define Y2 variable, the Y value of the end point coordinate of the line segment);

[0078] For t=0to 1step 0.001

[0079] theta = t*360*PI / 180*Z1;

[0080] X2 = r*cos((1-Z2 / Z1)*theta)-e*cos(Z2 / Z1*theta)'(assign the end point coordinate X value);

[0081] Y2=r*sin((1-Z2 / Z1)*theta)+e*sin(Z2 / Z1*theta)'(assign the end point coordinate Y value);

[0082] Picture1.Line(X1, Y1)-(X2, Y2), vbBlack' (connect the ends with a line segment);

[0083] X1=X2' (reassign the starting point coordinate X value);

[0084] Y1=Y2' (reassign the starting point coordinate Y value);

[0085] Next t.

[0086] Step 5: In the "Common normal" column, according to the drawn tooth profile, the designer determines the number of teeth spanned by the common normal distance, and whether the center is symmetrical relative to the X-axis or the Y-axis. Then select the approximate area of ​​the tooth profile and check the object's check box. At this time, the common normal calculation module will automatically calculate and draw two parallel common normal tangents (red straight lines) based on the existing node coordinates. The vertical distance between the two parallel tangents in the figure, Wk=16.139595, is the common normal constant of the inner rotor of the oil pump, such as Figure 4 As shown:

[0087] The maximum values ​​of the gear profile in the X and Y directions are determined by image recognition. The main code is as follows:

[0088] Dim X1 as Double' (define X1 variable, select the X value of the upper left corner coordinate of the rectangle);

[0089] Dim Y1 as Double' (define Y1 variable, select the Y value of the upper left corner of the rectangle);

[0090] Dim X2 as Double' (define X2 variable, select the X value of the lower right corner coordinate of the rectangle);

[0091] Dim Y2 as Double' (define Y2 variable, select the Y value of the lower right corner of the rectangle);

[0092] Dim TempX As Double (define TempX variable, maximum value of node X);

[0093] Dim TempY As Double (define TempY variable, maximum value of node Y);

[0094] Dim TempColor1 As Variant' (define TempColor1 variable);

[0095] Dim TempColor2 As Variant' (define TempColor2 variable);

[0096] " / *By scanning the nodes row by row, find the maximum value X in the horizontal coordinate direction and the maximum value Y in the vertical coordinate direction* / ".

[0097] For m = X1 To X2 Step 0.001' (loop coordinate X value);

[0098] For n = Y1 To Y2 Step 0.001' (loop coordinate Y value);

[0099] TempColor1 = Picture2.BackColor' (set the color of image recognition);

[0100] TempColor2 = Picture1.Point(m,n)' (assign the point color to TempColor2);

[0101] If TempColor1=TempColor2 Then'(Current color is equal to set color);

[0102] If m>TempX Then'(Judge the size)

[0103] TempX = m' (assign the larger value m to the TempX variable);

[0104]

[0105] According to the drawn tooth profile, in the area where the parallel common normal tangent tooth profile needs to be drawn, select a rectangle. If the cross-tooth direction is symmetrical with the X-axis, the rectangle has an aspect ratio greater than 1. If the cross-tooth direction is symmetrical with the Y-axis, the rectangle has an aspect ratio less than 1. Then, by scanning the nodes row by row, find the maximum values ​​of the tooth profile in the X and Y directions in the rectangular area. The system automatically draws two parallel common normal tangents symmetrical relative to the X or Y axis according to the distance of the common normal from the cross-tooth direction.

[0106] Step 6: In the "Show Type" column, you can decide to display / hide the graphics according to the design needs. Use the Rotor Color drop-down text box to select the color of the inner rotor line for easy identification. Figure 5 As shown, the inner rotor tooth profile is displayed and the outer rotor tooth profile is hidden.

[0107] In this embodiment, the operation demonstration of the system of this embodiment can basically complete the drawing of a set of inner and outer rotors, the calculation and drawing of the common normal constant of the inner rotor of the oil pump within 1 to 2 minutes. The entire design and calculation process is extremely simple and efficient. Compared with manual calculation, the difficulty of mathematical derivation is greatly reduced, the efficiency is high, and the time spent is almost negligible. Moreover, when parameter adjustment, re-drawing and calculation are required, the efficiency improvement is more obvious.

[0108] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A system for calculating the common normal of an inner rotor of an oil pump, characterized in that: The system comprises a rotor parameterized design module and a data storage module. The rotor parameterized design module is used to draw the inner rotor tooth profile, and then the inner rotor common normal line is calculated by tooth profile image recognition processing.

2. The oil pump inner rotor common normal calculation system according to claim 1, characterized in that: The rotor parameterized design module includes a data I / O module, a tooth profile node calculation module, a tooth profile contour drawing module and a common normal calculation module.

3. The oil pump inner rotor common normal calculation system according to claim 2, characterized in that: The data I / O module provides a data input interface for users to input parameter information of inner and outer rotors, which is exported and stored in a specified project file through a parameter export module. At the same time, users can import parameters in a specified project file at any time through a parameter import module to modify the design; The tooth profile node calculation module receives parameter information from the data I / O module and calculates the coordinate values ​​of all nodes within the range of 0-360° of the rotor tooth profile; The tooth profile drawing module: calls the coordinates of the nodes in the tooth profile node module and draws and displays the tooth profile graphics; The common normal calculation module automatically calculates and draws two parallel common normal tangents based on the recognition of the drawn tooth profile graphic, and calculates the vertical distance between the two parallel tangents to obtain the common normal constant.

4. A method for calculating the common normal line of an inner rotor of an oil pump, implemented by using the system for calculating the common normal line of an inner rotor of an oil pump as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Input the parameter information of the inner and outer rotors in advance through the data input interface and store it in a data file of a specified format; S2: Call or load the parameters of the inner and outer rotors from the specified file, pre-calculate the relevant parameters required by the cycloid equation, and bring the relevant parameters into the cycloid equation to calculate the coordinate values ​​of all nodes within the range of 0-360° of the rotor tooth profile; S3: Draw the tooth profile, call the node coordinate data in S2, connect the end with the line segment, draw it in the drawing area and display it; S4: Based on the drawn tooth profile, determine the number of teeth spanned by the normal distance and whether the center is symmetrical relative to the X-axis or the Y-axis; then select the tooth profile area, and the system automatically calculates and draws two parallel normal tangents to calculate the normal constant of the inner rotor.

5. The method for calculating the common normal line of the inner rotor of the oil pump according to claim 4, characterized in that: In S2, call or load the inner and outer rotor parameters from the specified file, pre-calculate the relevant parameters required by the cycloid equation, and bring the relevant parameters into the cycloid equation to calculate the specific contents of all node coordinate values ​​within the range of 0-360° of the rotor tooth profile: According to the equation group obtained by transforming the parameter equation of the inner rotor theoretical profile curve, the coordinate values ​​of each node are calculated. The formula is as follows: theta = t × 360 × PI / 180 × Z1; X=r×cos((1-Z2 / Z1)×theta)-e×cos(Z2 / Z1×theta); Y=r×sin((1-Z2 / Z1)×theta)+e×sin(Z2 / Z1×theta); Wherein, theta represents radians; t represents the introduced parameter; 0≤t≤1; X represents the node horizontal coordinate value; Y represents the node vertical coordinate value; r represents the radius of the distribution circle of the creation circle; e represents the eccentric distance of the inner and outer rotor meshing; Z1 represents the number of teeth of the inner rotor; Z2 represents the number of teeth of the outer rotor; PI represents pi.

6. The method for calculating the common normal line of the inner rotor of the oil pump according to claim 4, characterized in that: In S4, according to the drawn tooth profile, the number of teeth spanned by the common normal distance is determined, and whether the center is symmetrical relative to the X axis or the Y axis; then the tooth profile area is selected, and the system automatically calculates and draws two parallel common normal tangents. The specific content of calculating the common normal constant of the inner rotor is: According to the drawn tooth profile, in the area where the parallel common normal tangent tooth profile needs to be drawn, select a rectangle. If the cross-tooth direction is symmetrical with the X-axis, the rectangle has an aspect ratio greater than 1. If the cross-tooth direction is symmetrical with the Y-axis, the rectangle has an aspect ratio less than 1. Then, by scanning the nodes row by row, find the maximum values ​​of the tooth profile in the X and Y directions in the rectangular area. The system automatically draws two parallel common normal tangents symmetrical relative to the X or Y axis according to the distance of the common normal from the cross-tooth direction.

7. A computer-readable storage medium for storing a program, characterized in that: When the program is executed, the steps of the method for calculating the common normal line of the inner rotor of the oil pump according to any one of claims 4 to 6 are implemented.

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