A design method for the installation angle of a bucket tooth of a wheel bucket excavator

Abstract

The application provides a wheel bucket excavator bucket tooth installation angle design method, solves the problem of serious wear of individual bucket teeth on a bucket in a traditional wheel bucket excavator bucket tooth installation angle design method, and seriously affects production efficiency and production cost during replacement stoppage, and the technical scheme is as follows: comprising the following steps: determining the number of bucket teeth on the bucket; setting the installation angle of the cutting bucket tooth, calculating the wear amount of the bucket tooth, respectively optimizing the wear amount of the cutting bucket tooth, determining the cutting bucket tooth according to the orthogonal design result of step four. The wear degree of the bucket tooth is greatly reduced, the service life of the bucket tooth is improved, the frequent replacement condition of the bucket tooth is improved, the production efficiency of the wheel bucket excavator is improved, and the replacement cost of the bucket tooth is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wheel bucket excavating equipment, in particular to a design method of bucket tooth installation angle of a wheel bucket excavator. BACKGROUND

[0002] The wheel bucket excavator is a heavy equipment used for open-pit mining and stripping material. When the wheel bucket excavator is excavating, the self-rotation movement of the bucket wheel device and the rotation movement of the material receiving arm frame are simultaneously performed to form a series of crescent-shaped material cuttings. The complexity of the load and movement brings great difficulty to the design of the bucket tooth installation angle of the wheel bucket excavator. The traditional design method of the bucket tooth installation angle of the wheel bucket excavator is often based on the past design experience and field use experience. However, the wheel bucket excavator is a customized product, and the design of the bucket tooth installation angle should be matched with the physical and mechanical properties of the material of the open-pit mine, the process parameters, so that the wheel bucket excavator used in the field often has the problem of serious wear of individual bucket teeth on the bucket, which seriously affects the production efficiency and production cost. SUMMARY

[0003] The purpose of the present application is to provide a design method of the bucket tooth installation angle of a wheel bucket excavator, which solves the problem of serious wear of individual bucket teeth on the bucket in the traditional design method of the bucket tooth installation angle of the wheel bucket excavator, and seriously affects the production efficiency and production cost. It can reduce the wear degree of individual bucket teeth of the wheel bucket excavator and improve the production efficiency.

[0004] The technical solution adopted by the present application is: the design method of the bucket tooth installation angle of the wheel bucket excavator comprises the following steps: step one, determining the number of bucket teeth on the bucket

[0005] According to the physical and mechanical parameters of the excavated material and the lip length of the bucket, the total number N of bucket teeth of the unit bucket and the number M of cutting bucket teeth participating in cutting are determined, so that the relationship between the number of cutting bucket teeth and the total number of bucket teeth satisfies N-2≤M≤N.

[0006] Step two, setting the installation angle of the cutting bucket teeth

[0007] (1) Set the bucket angle, which is the included angle between the plane where the lip edge line is located and the radial plane of the bucket wheel body passing through the end point of the lip, design the lip of the cutting bucket teeth into a polygon with M sides, and each vertex of the polygon is located on the lip curve, which is a circular arc line symmetric to the center line of the bucket wheel body;

[0008] (2) Establish an independent bucket tooth coordinate system for each cutting bucket tooth, and the origin of the bucket tooth coordinate system is the midpoint of the corresponding lip edge;

[0009] The X-axis of the bucket tooth coordinate system is the tangent direction of the arc line concentric with the cylindrical surface of the bucket wheel body at the origin of the bucket tooth coordinate system. The Y-axis is the projection direction of the corresponding bucket lip edge on the radial plane of the bucket wheel body passing through the end point of the bucket lip. The Z-axis is determined by the X-axis and Y-axis of the bucket tooth coordinate system through the right-hand coordinate system.

[0010] (3) Set the projection angle a of the cutting bucket teeth in their respective bucket tooth coordinate systems i ,

[0011] Projection angle a i is the angle between the projection line of the tooth characteristic line of the i-th bucket tooth involved in cutting on the XOY plane of the bucket tooth coordinate system and the X-axis. The tooth characteristic line is the symmetry line of the rear edge face or the front edge face of the bucket tooth;

[0012] (4) Set the projection angle b of the cutting bucket teeth in their respective bucket tooth coordinate systems i ,

[0013] Projection angle b i is the angle between the projection line of the characteristic line of the i-th bucket tooth involved in cutting on the XOZ plane of the bucket tooth coordinate system and the X axis;

[0014] The installation angle is determined by the bucket inclination angle, projection angle a i and projection angle b i limited;

[0015] Step 3: Calculate bucket tooth wear

[0016] (1) Calculate the number of slices in a complete rotation process of the bucket wheel excavator based on the design parameters of the bucket wheel excavator. The design parameters include: slice thickness, slice width, rotation speed, rotation speed, tooth feed, left and right rotation limit angles, and receiving arm pitch angle;

[0017] (2) For all slices generated in a complete rotary cutting process, the motion equation of the bucket tooth corresponding to each slice is established, and the velocity vector v of the midpoint of the tooth tip of the cutting bucket tooth at each moment is calculated respectively. i ;

[0018] (3) Select a specific number of calculation points for each cutting tooth;

[0019] (4) For the cutting bucket teeth, determine the bucket tooth force F corresponding to each calculation point. i , the force F of the bucket tooth i Obtained through simulation analysis or bucket tooth cutting material test or bucket tooth cutting data model calculation;

[0020] (5) For cutting bucket teeth, calculate the wear amount P of the bucket teeth according to the wear model. i (v i ,F i );

[0021] Step four, respectively optimize the wear amount P of cutting bucket tooth i (v i ,F i )

[0022] For wear amount P i (v i ,F i ), the orthogonal design method is used to change the bucket dip angle, the bucket lip curve and the projection angle a i And the projection angle b i Of the i-th bucket tooth, when the wear amount P i (v i ,F i ) of each bucket tooth does not meet the allowable value of wear amount, steps one to three are repeated to design and calculate; when the wear amount P i (v i ,F i ) of each bucket tooth meets the allowable value of wear amount, the next step is carried out, and the allowable value of wear amount is calculated according to the service life of the wheel bucket excavator.

[0023] Step five, according to the orthogonal design result of step four, the final cutting bucket tooth installation angle selects the corresponding bucket tooth projection angle a i And the projection angle b i Of the minimum wear amount, and the corresponding bucket dip angle and bucket lip polygon, determine the cutting bucket tooth.

[0024] The wheel bucket excavator bucket tooth installation angle design method provided by the present application starts from the bucket lip shape matched with the number of bucket teeth, establishes a bucket tooth wear amount calculation model based on a complete rotary excavation process, considers multiple influencing factors such as bucket tooth stress and speed in the model, finds the optimal bucket tooth installation angle through the orthogonal design method, and can obtain the matched bucket lip shape. The bucket tooth installation angle design method of the present application can meet the customized design requirements of excavating different materials and adapting to different process parameters of the wheel bucket excavator, greatly reduces the wear degree of the bucket tooth, improves the service life of the bucket tooth, improves the situation of frequent replacement of the bucket tooth, improves the production efficiency of the wheel bucket excavator, and reduces the replacement cost of the bucket tooth. BRIEF DESCRIPTION OF DRAWINGS

[0025] The present application will be further described below in conjunction with the drawings.

[0026] Figure 1 is a structure schematic diagram of the excavator bucket wheel body of the present application;

[0027] Figure 2 is a bucket lip structure schematic diagram of the cutting bucket tooth of the present application;

[0028] Figure 3 Schematic diagram of the bucket tooth coordinate system structure of the cutting bucket tooth of the present invention;

[0029] Figure 4 It is a schematic diagram of the XOY coordinate surface structure of the bucket tooth coordinates of the present invention;

[0030] Figure 5 It is a schematic diagram of the ZOY coordinate surface structure of the bucket tooth coordinates of the present invention;

[0031] Figure 6 It is a schematic structural diagram of the cutting bucket tooth of the present invention;

[0032] Figure 7 It is a design flow chart of the present invention.

[0033] Explanation of the serial numbers in the figure: 1 bucket wheel body, 2 bucket, 3 cutting bucket tooth, 4 bucket inclination angle, 5 bucket lip, 6 bucket lip curve, 7 bucket wheel body radial plane. DETAILED DESCRIPTION

[0034] according to Figures 1-7 The present invention is described in detail. Figures 1 to 7 As shown, the embodiment is a method for designing the installation angle of bucket teeth of a bucket wheel excavator, which designs the installation angle of the cutting bucket teeth 3 of the bucket 2 on the bucket wheel body 1 of the bucket wheel excavator, including the following steps:

[0035] Step 1: Determine the number of teeth on the bucket

[0036] The total number of bucket teeth N on the unit bucket 2 and the number of cutting teeth M involved in cutting are determined based on the physical and mechanical parameters of the excavated material and the length of the bucket lip 5, so that the relationship between the number of bucket teeth involved in cutting and the total number of bucket teeth satisfies N-2≤M≤N. In this embodiment, the total number of bucket teeth N is 8, and the number of teeth involved in cutting M is 6. The bucket teeth at the left and right ends of the bucket do not participate in cutting, and the remaining 6 bucket teeth are involved in cutting.

[0037] Step 2: Set the installation angle of the cutting bucket teeth

[0038] (1) Set the bucket inclination angle 4, which is the angle between the plane where the bucket lip edge line is located and the bucket wheel body radial plane 7 passing through the bucket lip end point. The bucket lip of the cutting bucket tooth is designed as a polygon with M sides. The vertices of the polygon are located on the bucket lip curve 6. The bucket lip curve is a left-right symmetrical arc line with the bucket wheel body centerline as the symmetry axis. The shape of the bucket lip curve meets the requirements of the bucket wheel body width, bucket tooth depth, and bucket volume. The value of the bucket inclination angle in this embodiment is 1°~45°.

[0039] (2) Establish an independent bucket tooth coordinate system for each cutting bucket tooth. The origin of the bucket tooth coordinate system is the midpoint of the corresponding bucket lip. The bucket tooth coordinate system is used to determine the installation angle of the cutting bucket tooth on the bucket lip.

[0040] The X-axis of the bucket tooth coordinate system is the tangent direction of the arc line concentric with the cylindrical surface of the bucket wheel body at the origin of the bucket tooth coordinate system. The Y-axis is the projection direction of the corresponding bucket lip edge on the radial plane of the bucket wheel body passing through the end point of the bucket lip. The Z-axis is determined by the X-axis and Y-axis of the bucket tooth coordinate system through the right-hand coordinate system.

[0041] (3) Set the projection angle a of the cutting bucket teeth in their respective bucket tooth coordinate systems i ,

[0042] Projection angle a i is the angle between the projection line of the tooth characteristic line of the i-th bucket tooth involved in cutting on the XOY plane of the bucket tooth coordinate system and the X-axis. The tooth characteristic line is the symmetry line of the rear edge face or the front edge face of the bucket tooth;

[0043] (4) Set the projection angle b of the cutting bucket teeth in their respective bucket tooth coordinate systems i ,

[0044] Projection angle b i is the angle between the projection line of the characteristic line of the i-th bucket tooth involved in cutting on the XOZ plane of the bucket tooth coordinate system and the X axis;

[0045] The installation angle is determined by the bucket inclination angle, projection angle a i and projection angle b i limited;

[0046] Step 3: Calculate bucket tooth wear

[0047] (1) Calculate the number of slices in a complete rotation process of the bucket wheel excavator based on the design parameters of the bucket wheel excavator. The design parameters include: slice thickness, slice width, rotation speed, rotation speed, tooth feed, left and right rotation limit angles, and receiving arm pitch angle;

[0048] (2) For all slices generated in a complete rotary cutting process, the motion equation of the bucket tooth corresponding to each slice is established, and the velocity vector v of the midpoint of the tooth tip of the cutting bucket tooth at each moment is calculated respectively. i ;

[0049] (3) Select a specific number of calculation points for each cutting tooth;

[0050] (4) For the cutting bucket teeth, determine the bucket tooth force F corresponding to each calculation point. i , the force F of the bucket tooth i Obtained through simulation analysis or bucket tooth cutting material test or bucket tooth cutting data model calculation;

[0051] (5) For cutting bucket teeth, calculate the wear amount P of the bucket teeth according to the wear model. i (v i ,Fi );

[0052] Step four, respectively, optimize the wear amount P of cutting bucket tooth i (v i ,F i )

[0053] For wear amount P i (v i ,F i ), the orthogonal design method is used to change the bucket dip angle, lip curve and the projection angle a i And the projection angle b i Of the i-th bucket tooth, when the wear amount P i (v i ,F i ) of each bucket tooth does not meet the allowable value of wear amount, steps one to three are repeated to design and calculate; when the wear amount P i (v i ,F i ) of each bucket tooth meets the allowable value of wear amount, the next step is carried out, and the allowable value of wear amount is calculated according to the service life of the wheel bucket excavator.

[0054] Step five, according to the orthogonal design results of step four, the final cutting bucket tooth installation angle selects the corresponding bucket tooth projection angle a i And the projection angle b i Corresponding to the bucket dip angle and the lip polygon, the cutting bucket tooth is determined.

[0055] Effect comparison: the bucket tooth designed by the bucket tooth installation angle design method of the present application can effectively reduce the wear degree of the bucket tooth. Through the investigation of the wear degree of the bucket tooth used on the wheel bucket excavator in the open pit mine site, the bucket tooth designed without using the method of the present application is replaced every 28 days. Under the premise of not changing the material and shape of the bucket tooth, only by changing the installation angle of the bucket tooth by using the method of the present application, the bucket tooth is replaced every 37 days, and the replacement frequency of the bucket tooth is reduced by 32%.

[0056] In summary, the purpose of the present application is achieved.

Claims

1. A method of designing a bucket tooth mounting angle of a wheel-bucket excavator, characterized by, The method comprises the following steps: Step one, determine the number of bucket teeth on the bucket According to the physical and mechanical parameters of the excavated material and the lip length of the bucket, the total number of bucket teeth N and the number of cutting teeth M participating in cutting are determined, so that the relationship between the number of cutting teeth and the total number of teeth satisfies N-2≤M≤N; Step two, set the installation angle of the cutting teeth (1) Set the bucket angle, which is the angle between the plane where the bucket lip edge line is located and the radial plane of the bucket wheel body passing through the end point of the bucket lip. The cutting teeth lip is designed as a polygon with M sides, and each vertex of the polygon is located on the bucket lip curve, which is a circular arc line symmetric to the center line of the bucket wheel body; (2) Establish an independent bucket tooth coordinate system for each cutting tooth, and the origin of the bucket tooth coordinate system is the midpoint of the corresponding bucket lip edge; The X-axis of the bucket tooth coordinate system is the tangent direction of the concentric circular arc line of the bucket wheel body cylinder at the origin of the bucket tooth coordinate system, the Y-axis is the projection direction of the corresponding bucket lip edge on the radial plane of the bucket wheel body passing through the end point of the bucket lip, and the Z-axis is determined by the X-axis and Y-axis of the bucket tooth coordinate system through the right-hand coordinate system; (3) Set the projection angle a of the cutting bucket tooth in the respective bucket tooth coordinate system i , Projection angle a i is the angle between the projection of the i-th participating cutting tooth feature line on the XOY plane of the cutting tooth coordinate system and the X-axis, the i-th participating cutting tooth feature line being the symmetry line of the back or front cutting tooth edge surface. (4) The projection angle b of the cutting pick in the respective pick coordinate system is set respectively i , Projection angle b i is the angle between the projection of the i-th participating cutting tooth feature line on the XOZ plane of the tooth coordinate system and the X-axis. The installation angle is defined by the bucket dip angle, the projection angle a i and the projection angle b i are defined; Step three, calculate the wear amount of the bucket tooth (1) According to the design parameters of the wheel bucket excavator, the number of slices in a complete rotation process of the wheel bucket excavator is calculated, and the design parameters include: slice thickness, slice width, rotation speed, rotation speed, tooth penetration, left and right rotation limit angle, and material receiving arm pitch angle; (2) For all the slices generated in a complete rotary cutting process, the motion equations of the cutting tooth corresponding to each slice are established, and the velocity vector v of the tooth tip midpoint of the cutting tooth at each time is calculated respectively i ; (3) Select a certain number of calculation points for each cutting tooth; (4) For cutting the cutting tooth respectively and each calculation point corresponding to the tooth force F i , the force F i of the tooth is obtained according to simulation analysis or tooth cutting material test or tooth cutting data model calculation; (5) According to the wear model, the wear amount P of the cutting bucket tooth is calculated respectively i (v i ,F i ) Step four, respectively optimize the wear amount P of cutting bucket tooth i (v i ,F i ) For wear amount P i (v i ,F i ), using the orthogonal design method, changing the bucket inclination angle, bucket lip curve and the projection angle a of the i-th bucket tooth i and projection angle b i , when the wear amount of each bucket tooth P i (v i ,F i ) does not meet the allowable value of wear, repeat the design steps one to three to perform design calculations; when the wear of each bucket tooth P i (v i ,F i ) When the allowable wear value is met, proceed to the next step. The allowable wear value is calculated based on the service life of the bucket wheel excavator; Step five, according to the orthogonal design results of step four, the final cutting tooth installation angle selects the corresponding tooth projection angle a when the respective wear amount is the smallest i and projection angle b i , and the corresponding bucket dip angle and lip polygon, determine the cutting tooth.

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