CN107044282A - A kind of Vertical Axis Road-header virtual prototype cutterhead LOAD FOR and loading method - Google Patents

Abstract

A method for calculating and loading the load of a cutting head of a virtual prototype of a longitudinal-axis roadheader, belonging to the technical field of virtual prototypes of mining equipment; including obtaining coal and rock occurrence conditions; obtaining the rotation angular velocity of the cutting head, and calculating the cutting speed of the cutting head; Obtain the swing angular velocity of the cantilever, calculate the lateral swing velocity of the pick; calculate the cutting resistance, traction resistance and lateral resistance of the pick; decompose the cutting resistance, traction resistance and lateral resistance of the pick orthogonally, and divide each The force on the pick is converted to the center of mass of the cutting head, and the three-dimensional force and moment on the cutting head are obtained; the load is applied to the center of mass of the cutting head through ADAMS; the present invention only needs to change the coal and rock occurrence conditions Complete the application of cutting head load under different working conditions, simplify the load application process and improve work efficiency; consider the time-varying nature of cantilever swing speed and cutting head speed, and the calculation results are accurate; can find the shortcomings in the design of roadheaders, Find the weak link in roadheader components.

Description

A Load Calculation and Loading Method of the Cutting Head of a Virtual Prototype of Longitudinal Axis Tunneling Machine

technical field

The invention belongs to the technical field of virtual prototypes of excavation equipment, and in particular relates to a load calculation and loading method for a cutting head of a virtual prototype of a longitudinal-axis roadheader.

Background technique

The cantilever roadheader is one of the key equipment in fully mechanized excavation face. As the key component of the roadheader for crushing coal and rock, the cutting head consumes about 70% to 80% of the total power of the roadheader. The design quality of the cutting head will not only affect the working reliability and service life of the roadheader, but also play a decisive role in the cutting performance and cutting economy of the roadheader, and the load calculation of the cutting head based on the actual working conditions is the most important An important step in cutting head design.

my country's mining equipment manufacturers have been using the traditional design model for product research and development. A new product usually has to go through many trials, tests and improvements before it can be put on the market. The cost of trial production and testing of mining machinery is high, resulting in insufficient repeated tests. In addition, the lack of knowledge of the coal and rock cutting mechanism makes it difficult to find the essential defects of the product, which directly leads to the failure of the performance indicators, technical level and operating parameters of mining equipment in my country. The backwardness in many aspects, such as products put on the market, has congenital deficiencies and lacks competitiveness in the market, which seriously restricts the improvement of product quality and the rapid development of my country's equipment manufacturing industry. At present, most of the large-scale equipment used in my country's high-yield and high-efficiency mines are manufactured by foreign manufacturers, and there is a lack of independent innovative products.

The coal-rock occurrence conditions and the two-way coupling between the cutting head and the coal-rock lead to nonlinear, impact and strong coupling loads on the cutting head, which are difficult to describe in a computer using simple function combinations. Therefore, it is necessary to find a reasonable and efficient method to realize the simulation and loading of the cutting head load, which is of great significance to the research and design of roadheaders.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a load calculation and loading method for a cutting head of a virtual prototype of a longitudinal axis roadheader.

Technical scheme of the present invention is as follows:

A load calculation and loading method for a cutting head of a virtual prototype of a vertical axis roadheader, comprising:

Step 1: Obtain coal and rock occurrence conditions and store them in the static storage area;

The coal and rock occurrence conditions include coal occurrence conditions and rock occurrence conditions, and the coal occurrence conditions include the average value of coal seam cutting resistance, coal brittleness coefficient, and mine pressure influence coefficient in non-ground pressure affected areas. , the uniaxial compressive strength of coal and the coefficient of coal compression state; the occurrence conditions of rock include rock contact strength.

Step 2: Obtain the rotation angular velocity of the cutting head through the function interface provided by ADAMS, and calculate the cutting speed of the cutting head;

Step 3: Obtain the swing angular velocity of the cantilever through the function interface provided by ADAMS, and calculate the lateral swing velocity of the pick;

Step 4: Calculate the cutting resistance, traction resistance and lateral resistance of the pick according to the coal breaking theory of the pick tooth, using the coal rock occurrence conditions, the cutting speed of the cutting head, the lateral swing speed of the pick and the design parameters of the pick ;

Step 5: The cutting resistance, traction resistance and lateral resistance of the pick are decomposed orthogonally, and the force on each pick is transformed to the center of mass of the cutting head according to the force translation theorem, and the three-dimensional force on the cutting head is obtained. The force and three-way moment are the load of the cutting head;

The calculation process of the above three-direction force and three-direction moment on the cutting head is based on the rules of ADAMS secondary development, written in C language, and compiled into a dynamic link library file.

The cutting head load is described by GForce in ADAMS, and implemented by adams_c_Gfosub function.

Step 6: Apply the load to the center of mass of the cutting head through ADAMS. The specific process is: run the virtual prototype of the ADAMS roadheader, and ADAMS loads the dynamic link library file, and the marking points of the cutting head, the cantilever and each center of rotation The ID is passed to the adams_c_Gfosub function. After the function is executed, ADAMS uses the current calculation result of the function as the value of the three-way force and three-way moment contained in GForce to participate in the simulation calculation of the virtual prototype to realize the loading of the load at the center of mass of the cutting head. .

Beneficial effects: Compared with the prior art, a method for calculating and loading the cutting head load of a virtual prototype of a vertical axis roadheader has the following advantages:

(1) Using the secondary development interface of ADAMS, the real-time calculation and loading of the cutting head load of the virtual prototype of the roadheader is realized by using the C language;

(2) The application of cutting head load under different working conditions can be completed only by changing the coal and rock occurrence conditions, which simplifies the load application process and improves work efficiency;

(3) During the load calculation process, the time-varying factors of the cantilever swing speed and the cutting head rotation speed are considered to make the calculation results more accurate;

(4) Using this method, in the virtual experiment based on the virtual prototype of the roadheader, the shortcomings in the design of the roadheader can be found, and the weak links in the parts of the roadheader can be found.

Description of drawings

Fig. 1 is a flow chart of the load calculation and loading method of the virtual prototype cutting head of the vertical axis roadheader in an embodiment of the present invention;

Fig. 2 is a schematic diagram of the pick force in an embodiment of the present invention;

Fig. 3 is a schematic diagram of the force conversion of the pick according to an embodiment of the present invention;

Fig. 4 is a flow chart of the load calculation process of an embodiment of the present invention;

Fig. 5 is a curve diagram of the load time course of the cutting head under the working condition of an embodiment of the present invention;

Fig. 6 is a curve diagram of the load time course of the cutting head under the second working condition of an embodiment of the present invention;

Fig. 7 is a curve diagram of the load time history curve of the cutting head under the third working condition of an embodiment of the present invention;

Fig. 8 is a graph showing the load time history curve of the cutting head under working condition 4 according to an embodiment of the present invention.

detailed description

An embodiment of the present invention will be described in detail below in conjunction with the accompanying drawings.

In this embodiment, as shown in FIG. 1, a method for calculating and loading the cutting head load of a virtual prototype of a longitudinal-axis roadheader includes the following steps:

Step 1: Obtain coal and rock occurrence conditions and store them in the static storage area;

The coal and rock occurrence conditions include coal occurrence conditions and rock occurrence conditions, and the coal occurrence conditions include the average value of coal seam cutting resistance, coal brittleness coefficient, and mine pressure influence coefficient in non-ground pressure affected areas. , the uniaxial compressive strength of the coal and the coefficient of coal under compression; the occurrence conditions of the rock include the rock contact strength.

Step 2: Obtain the rotation angular velocity of the cutting head through the function interface provided by ADAMS, and calculate the cutting speed of the cutting head;

Step 3: Obtain the swing angular velocity of the cantilever through the function interface provided by ADAMS, and calculate the lateral swing velocity of each pick;

Step 4: Extract the design parameters of the pick, and calculate the cutting resistance of the pick according to the coal-breaking theory of the pick tooth, using the coal and rock occurrence conditions, the cutting speed of the cutting head, the lateral swing speed of the pick and the design parameters of the pick , traction resistance and lateral resistance;

As shown in Figure 2, it is a schematic diagram of force when the pick cuts coal rock;

Step 4-1: Calculate the cutting resistance Z _j and traction resistance Y _j of the pick j involved in cutting coal and rock in sequence:

j=1, 2, ..., N, N is the total number of picks, in the present embodiment, N=42; when the pick j is cutting coal, the cutting resistance Z _j and the traction resistance Y _j of the pick j are equal to The calculation method is as follows:

The cutting resistance Z ₀ and traction resistance Y ₀ of the sharp pick when cutting coal are:

Y ₀ ＝(0.5～0.8)Z ₀

In the formula: ——Average value of coal seam cutting impedance in non-ground pressure affected area, N/mm;

b _p ——the calculated width of the working part of the pick, cm;

h _{jmax ——the} maximum cutting thickness of the pick, cm;

t _{cp ——the} chip width of pick, cm;

K _z —coefficient of exposed free surface;

K _y —influence coefficient of truncation angle;

——Influence coefficient of the shape of the front edge of the pick;

K _C —coefficient of pick arrangement;

K _{ot —coefficient} of influence of ground pressure on coal wall;

β——the deflection angle of the pick to the pulling direction, (°);

K _{ψ —coal} brittleness coefficient;

θ—the position angle of the pick, (°).

Among them, the formula for calculating the maximum chip thickness of the jth pick on the cutting head is:

In the formula: h _{jmax ——the} maximum chip thickness of the jth tooth, mm;

V _{bj ——the} lateral swing speed of the jth pick, m/min;

β _j ——the angle between the installation axis of the jth pick and the rotation axis of the cutting head;

m - the number of picks on the same section;

n——cutting speed of cutting head, r/min.

For blunted picks, the cutting resistance Z _j and traction resistance Y _j encountered when cutting coal are:

Z _j ＝Z ₀ +100f′δ _cm S _a K _δ

Y _j ＝Y ₀ +100δ _cm S _a K _δ

In the formula: f′——cut impedance coefficient;

δ _cm —unidirectional compressive strength of coal, MPa;

S _a ——the projected area of the wear surface of the pick on the cutting plane, cm ² ;

K _δ —— volume coefficient of ore body stress state.

When the pick j is cutting rock formations or rocks such as gangue, fault, roof and floor, the calculation method of cutting resistance Z _j and traction resistance Y _j is as follows:

Z _j ＝P _K [k _T k _ψ k′ _ψ k _d k′ _y (0.25+1.8h _jmax sinθ·t _cp )+0.1S _j ]

Y _j ＝2.5Z _j (0.15+0.00056P _K )/(10h _jmax sinθ) ^0.4

In the formula: P _K —— rock contact strength P _K ＝44·f ^1.5 , MPa;

k _T ——the type coefficient of the pick;

k _ψ — shape coefficient of carbide head;

k′ _{ψ ——shape} coefficient of cutter head;

k _d ——Diameter coefficient of carbide cutter head;

k′ _y ——influence coefficient of pick cutting angle;

S _j ——the projected area of the wear surface on the cutting plane after the pick is worn when cutting the gangue, mm ² ;

Step 4-2: Calculate the lateral resistance X _j of the pick j involved in cutting coal and rock:

No matter whether the pick cuts the coal seam or the rock, in addition to the cutting resistance and traction resistance, it will also be subjected to lateral resistance. The calculation formula is:

where: X _j —— lateral resistance, in N;

C ₁ , C ₂ , C ₃ —— are related to the arrangement of the picks. The sequential formula takes 1.4, 0.3 and 0.15 respectively; the cross formula takes 1.0, 0.22 and 0.10 respectively.

Step 5: The cutting resistance, traction resistance and lateral force of the pick are decomposed orthogonally, and the force of each pick is transformed to the center of mass of the cutting head according to the translation theorem of force, and the three-dimensional force of the cutting head is obtained. force and three-way moment;

As shown in Figure 3, it is a schematic diagram of converting the force on the pick into the force on the cutting head, where CM is the center of mass of the cutting head;

According to the force translation theorem, the cutting resistance Z _j and traction resistance Y _j suffered by the pick j are converted to the intersection point of the cutting head rotation axis and the plane of the cutting line where the pick is located, and the orthogonal decomposition is carried out, Get the three-dimensional force R _xj , R _yj , R _zj of the pick j, and generate the cutting moment M _zj at the same time:

R _xj ＝Z _j ·sin(ω·t+φ _j )-Y _j ·cos(ω·t+φ _j )

M _Zj ＝-Z _j ·D _j /2

In the formula: ω—the angular velocity of cutting head rotation, rad/s;

φ _j ——At time t, the position angle of the jth pick in the circumferential direction of the cutting head, rad;

D _j ——the diameter of twice the radial distance of the jth tooth;

In this embodiment, the picks on the cutting head are arranged in a cross pattern, the ratio of the number of spiral heads to the number of picks per line is 2, and the picks participate in the cutting in the order of one at a time, forming a symmetrical cutting on both sides. The groove makes the force on both sides of the pick basically balanced, so the lateral force can be ignored in the calculation, so R _zj =0.

Transform the obtained forces and moments on each reference coordinate system to the center of mass CM of the cutting head, and obtain the instantaneous forces R _x , R _y and moments M _x , M _y , M _z on the center of mass of the cutting head at time t:

R _x ＝∑R _xj

R _y =∑R _yj

M _x ＝∑R _yj ×L _j

M _y ＝-∑R _xj ×L _j

M _z ＝∑M _Zj ＝-∑Z _j ×D _j /2

Among them, for the pick near the head of the cutting head, L _j takes a positive value, and for the pick near the end face, L _j takes a negative value; the reference coordinate system is the cutting line between the rotation axis of the cutting head and the pick j The coordinate system at the intersection of the planes of , whose direction is the same as that of the R _xj equal forces.

The calculation process of the above-mentioned three-direction force and three-direction moment on the cutting head is written and implemented in C language according to the rules of ADAMS secondary development, and is compiled into a dynamic link library file.

The cutting head load is described by GForce in ADAMS, and implemented by adams_c_Gfosub function.

In this embodiment, the three-way force and three-way moment calculation and load loading process are written in C language, and the specific implementation method is as follows:

Compile the user subroutine according to the cutting head load calculation process shown in Figure 4, in which the main function is written according to the C language version GFOSUB function type given by ADAMS, which is defined as:

typedef void

adams_c_Gfosub(const struct sAdamsGforce*gfo, double TIME, int DFLAG, int IFLAG, double*RESULT);

The motion parameters such as the rotational angular velocity of the cutting head and the yaw angular velocity of the pick are obtained through the SYSFNC function of ADAMS, and its C language version is defined as:

void

c_sysfnc(const char*fncnam, const int*ipar, int nsize, double*states,

int *errflg);

After the C program is written, save it as load.c file.

Compile the load calculation C program:

Open the Adams command prompt program Adams-CommandPrompt in the load.c storage directory, and enter the following command:

adams2015_1_x64cr-user n load.c -n ch_load.dll

Compile to get ch_load.dll.

Step 6: Apply the load to the center of mass of the cutting head through ADAMS, the specific method is:

Use ADAMS software to add GForce at the center of mass of the cutting head of the roadheader;

Open the dialog box for modifying GForce, enter the path and name of the dynamic link library file and the name of the load calculation function contained in it in the text box corresponding to the "Program" label, that is, the adams_c_Gfosub function, and enter the corresponding in the "User Parameters" label Enter the IDs of the cutting head, the cantilever and the marking points of each turning center in the text box;

Run the ADAMS roadheader virtual prototype, ADAMS loads the dynamic link library file, and passes the IDs of the cutting head, the cantilever and the marking points of each turning center to the adams_c_Gfosub function. After the function is executed, ADAMS uses the current calculation result of the function as The values of the three-direction force and three-direction moment included in GForce participate in the simulation calculation of the virtual prototype to realize the loading of the load at the center of mass of the cutting head.

Run the roadheader virtual prototype in ADAMS under the four simulation conditions shown in Table 1, and obtain the load curves of the cutting head under the four conditions, as shown in Figures 5-8.

Table 1 Parameter setting table of four kinds of simulation working conditions

Working condition serial number Valve opening ratio coal firmness factor rock solidity factor one 100% 1.4 9 two 100% 2.5 0 three 100% 2 6 Four 100% 0 9

It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the protection scope of the present invention.

Claims (5)

1. A vertical axis roadheader virtual prototype cutting head load calculation and loading method, is characterized in that, comprises the steps: Step 1: Obtain coal and rock occurrence conditions and store them in the static storage area; Step 2: Obtain the rotation angular velocity of the cutting head through the function interface provided by ADAMS, and calculate the cutting speed of the cutting head; Step 3: Obtain the swing angular velocity of the cantilever through the function interface provided by ADAMS, and calculate the lateral swing velocity of the pick; Step 4: Calculate the cutting resistance, traction resistance and lateral resistance of the pick according to the coal breaking theory of the pick tooth, using the coal rock occurrence conditions, the cutting speed of the cutting head, the lateral swing speed of the pick and the design parameters of the pick ; Step 5: The cutting resistance, traction resistance and lateral resistance of the pick are decomposed orthogonally, and the force of each pick is transformed to the center of mass of the cutting head according to the translation theorem of force, and the three-dimensional force of the cutting head is obtained. Force and three-way moment are loads; Step 6: Apply the load at the center of mass of the cutting head by ADAMS. 2. The cutting head load calculation and loading method of the virtual prototype of the vertical axis roadheader according to claim 1, characterized in that, the three-way force and three-way moment calculation of the cutting head in the steps 1 to 5 The process is based on the rules of secondary development of ADAMS, written and implemented in C language, and compiled into a dynamic link library file. 3. The method for calculating and loading the load of the cutting head of the virtual prototype of the vertical-axis roadheader according to claim 1, wherein the load is described in ADAMS using GForce and implemented using the adams_c_Gfosub function. 4. vertical axis type roadheader virtual prototype cutting head load calculation and loading method according to claim 1, is characterized in that, described coal rock occurrence condition comprises the occurrence condition of coal and the occurrence condition of rock, so The occurrence conditions of the coal include the average value of coal seam cut impedance in the non-ground pressure affected area, the brittleness coefficient of the coal, the influence coefficient of the mine pressure, the uniaxial compressive strength of the coal, and the coefficient of the coal body under pressure; Preservation conditions include rock contact strength. 5. vertical axis type roadheader virtual prototype cutting head load calculation and loading method according to claim 2, is characterized in that, described by ADAMS the specific process that load is applied to cutting head centroid place is as follows: Run the ADAMS roadheader virtual prototype, ADAMS loads the dynamic link library file, and passes the IDs of the cutting head, the cantilever, and the marking points of each turning center to the adams_c_Gfosub function. After the function is executed, ADAMS uses the current calculation result of the function as The values of the three-direction force and three-direction moment included in GForce participate in the simulation calculation of the virtual prototype to realize the loading of the load at the center of mass of the cutting head.