Shaft hole machining method, workpiece and assembling method

Abstract

The invention relates to a shaft hole machining method, a workpiece and an assembling method.The shaft hole machining method comprises the steps that during machining preparation, at least two opposite to-be-cut auxiliary parts are arranged at the end of a shaft hole of the to-be-machined workpiece in the radial direction; the to-be-removed part of the to-be-cut auxiliary part is removed through primary cutting, the maximum distance between two primary cutting faces is measured, the diameter of the end of the shaft hole is obtained, the unilateral machining allowance is calculated, the taper of the shaft hole is measured, the deviation between the taper value and a theoretical value is judged, the current cutting machining parameter is determined, and the follow-up rough cutting machining parameter is calculated. In order to prevent a ram of the machine tool from extending too long to influence the cutting precision and quality, before finish machining cutting, if the taper of the shaft hole is inconsistent with a theoretical value, cutting parameters are adjusted to enable the machine tool to stably cut at a constant speed, and the machining allowance after rough cutting is removed through one-time finish machining. The shaft hole machining method solves the problems that when the shaft hole of the vertical mining machine is machined, the machining amount in the depth direction of the shaft hole is large, so that the product shaft hole surface machining quality is poor, and the percent of pass is low.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, and in particular to a shaft hole processing method, a workpiece and an assembly method. Background Art

[0002] When processing the spindle hole of the mining machine, it is difficult to directly measure the diameter of the opening of the shaft hole. The processing volume in the depth direction of the shaft hole is large, close to the maximum extension of the machine tool slide. Once the slide extends too long, the machine tool will easily shake after being stressed, resulting in unstable surface quality of the workpiece shaft hole processing and difficult to control the processing qualification rate. Most mining machine mainframe products require secondary processing due to the mismatch of the spindle hole, which occupies the company's processing resources and causes certain economic losses. Summary of the invention

[0003] Based on this, it is necessary to provide a shaft hole processing method that is easy to operate, has easy control of processing accuracy and a high pass rate in order to solve the problem of shaft hole processing quality control.

[0004] The present invention provides a shaft hole machining method, comprising:

[0005] Processing preparation: at least two opposite auxiliary parts to be cut are arranged radially at the end of the axial hole of the workpiece to be processed, the upper end surface of the axial hole of the workpiece to be processed is adjusted to be parallel to the machine tool worktable, and the center line of the axial hole of the workpiece to be processed is adjusted to coincide with the center of the machine tool worktable;

[0006] Initial cutting: The side of the auxiliary piece to be cut close to the inner wall of the shaft hole is the part to be removed. The part to be removed is cut along the depth direction of the shaft hole to obtain the cut auxiliary piece and form an initial cutting surface. The curvature of the arc parallel to the radial direction of the shaft hole of the initial cutting surface is the same as the curvature of the cross-section circle at the end of the shaft hole;

[0007] Rough machining: measure the maximum distance between the initial cutting surfaces of the two cut auxiliary parts to obtain the current end diameter of the shaft hole; calculate the single-side machining allowance according to the drawing size and the current end diameter of the shaft hole, and measure the taper of the shaft hole. If the deviation between the taper value and the theoretical value is less than 10%, it is determined that the current cutting parameters are correct, and the subsequent rough cutting parameters are calculated according to the single-side machining allowance, and the shaft hole is cut multiple times;

[0008] Finishing: After the last rough cutting is completed, measure whether the taper of the shaft hole is consistent with the theoretical value. If not, adjust the cutting parameters to make the machine tool cut at a uniform and stable speed. Remove the machining allowance after rough cutting through one finishing process, so that the measured diameter of the shaft hole end is consistent with the drawing size, and remove the cut auxiliary parts.

[0009] In one embodiment, the shaft hole machining method further comprises the steps of:

[0010] Trial assembly: Perform trial assembly on the shaft to be assembled and the shaft hole to determine whether the shaft hole needs to be ground.

[0011] In one of the embodiments, after trial assembly, if the distance from the upper end surface of the shaft hole to the upper end surface of the shaft is less than a specified value, the corresponding thickness of material from the upper end surface of the shaft hole is removed; if the distance from the upper end surface of the shaft hole to the upper end surface of the shaft is greater than a specified value, the corresponding thickness of material from the inner cavity of the shaft hole is removed.

[0012] In one of the embodiments, when measuring the end diameter of the shaft hole during rough machining and fine machining, the maximum distance between the initial cutting surfaces of each pair of the cut auxiliary parts is measured at least twice and the average is taken as the current end diameter of the shaft hole.

[0013] In one of the embodiments, during processing preparation, an even number of auxiliary parts to be cut are arranged in pairs along the radial direction at the end of the axial hole of the workpiece to be processed; when measuring the diameter of the end of the axial hole during rough processing and fine processing, an inner diameter measuring tool is used to measure the maximum distance between each pair of the auxiliary parts to be cut or the cut auxiliary parts in turn and take the average.

[0014] In one of the embodiments, when measuring the taper of the shaft hole, the measuring dial is installed on the lower end of the machine tool slide, the machine tool slide is moved along the depth direction of the shaft hole, and the movement amount in the slide depth direction is read. The change amount along the radial direction of the shaft hole is read by the change of the pointer of the measuring dial, and the single-sided taper of the shaft hole is calculated.

[0015] In one of the embodiments, the measuring dial is rotated 90°, 180° or 270° relative to the shaft hole, and the shaft hole taper is repeatedly measured and an average value is taken to obtain the current shaft hole taper.

[0016] In one embodiment, the size of the auxiliary part to be cut meets the operating space requirement of the inner diameter measuring tool.

[0017] The present invention also provides a workpiece having an axial hole made by the axial hole machining method as described above.

[0018] The present invention also provides an assembly method, which uses the workpiece shaft hole obtained by the shaft hole processing method as mentioned above to assemble the shaft to be assembled. During assembly, the surface of the shaft to be assembled is cleaned, the shaft to be assembled is frozen and the shrinkage rate of the shaft to be assembled is controlled to obtain sufficient interference during assembly; after the freezing is completed and the surface frost is wiped off, the shaft to be assembled is placed in the shaft hole, and when the temperature returns to room temperature, the shaft and the shaft hole form an interference fit.

[0019] In the above-mentioned shaft hole processing method, when preparing for processing, at least two relative auxiliary parts to be cut are radially arranged at the end of the shaft hole of the workpiece to be processed, so as to facilitate the measurement of the inner diameter of the shaft hole. Through the initial cutting, the to-be-removed part of the auxiliary part to be cut is removed, so that the curvature of the arc parallel to the radial direction of the shaft hole of the initial cutting surface is the same as the curvature of the cross-sectional circle of the end of the shaft hole. By measuring the maximum distance between the initial cutting surfaces of the two cut auxiliary parts, the current diameter of the end of the shaft hole can be obtained. The single-sided machining allowance is calculated according to the drawing size and the current diameter of the end of the shaft hole, and the taper of the shaft hole is measured. If the deviation between the taper value and the theoretical value is less than 10%, it is determined that the current cutting processing parameters are correct, and the subsequent rough cutting processing parameters are calculated according to the single-sided machining allowance, and the shaft hole is cut multiple times. After the last rough cutting is completed, in order to avoid the machine tool slide extending too long to affect the cutting accuracy and quality, before the fine cutting, measure the taper of the shaft hole again to see if it is consistent with the theoretical value. If not, adjust the cutting parameters to make the machine tool cut at a uniform and stable speed. Through one fine cutting, remove the machining allowance after the rough cutting, so that the measured diameter of the shaft hole end is consistent with the size of the drawing, and ensure that the taper of the shaft hole after fine machining meets the machining requirements. Finally, remove the cut auxiliary parts. This shaft hole machining method is easy to operate, and the taper of the machined shaft hole is easy to control, which can ensure that the taper of the shaft hole meets the requirements. It solves the problem of poor surface machining quality and low qualified rate of the product shaft hole due to the large amount of machining in the depth direction of the shaft hole when machining the shaft hole of the vertical mining machine.

[0020] The above-mentioned workpiece has an axial hole made by the above-mentioned axial hole processing method. The axial hole of the workpiece has uniform taper, high processing accuracy and good processing quality.

[0021] The above-mentioned assembly method meets the interference requirement for assembly between the shaft and the shaft hole at room temperature by freezing the shaft to be assembled and controlling the shrinkage rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of a first viewing angle of an auxiliary part to be cut before being processed in an embodiment;

[0023] Figure 2 is a schematic diagram of a second viewing angle of an auxiliary part to be cut before being processed in an embodiment;

[0024] Figure 3 is a schematic diagram of a first viewing angle for measuring a cut auxiliary member in an embodiment;

[0025] Figure 4 is a schematic diagram of a second viewing angle for measuring a cut auxiliary member in an embodiment;

[0026] Figure 5 is a schematic diagram of measuring the taper of a shaft hole in one embodiment;

[0027] Figure 6It is a schematic diagram of trial assembly of the shaft hole and the shaft to be assembled in one embodiment;

[0028] Figure 7 A schematic diagram of installing a stop assembly under a shaft to be assembled in one embodiment; Figure 8 Flow chart of a shaft hole machining method in one embodiment.

[0029] Description of labels:

[0030] 1. Auxiliary parts to be cut; 2. Parts to be processed; 3. Upper end face of the shaft hole; 4. Center line; 5. Parts to be removed; 6. Cut auxiliary parts; 7. Inner diameter measuring tool; 8. First position; 9. Zero adjustment point; 10. Movement in depth direction; 11. Second position; 12. Drawing size; 13. Diameter of the end of the shaft hole; 14. Single-sided processing allowance; 15. Upper gap; 16. Lower gap; 17. End face spacing; 18. Reagent; 19. Stop block; 20. Stop rod. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0037] See also Figures 1 to 8 An embodiment of the present invention provides a method for machining a shaft hole, comprising the steps of:

[0038] Machining preparation: at least two opposite auxiliary parts 1 to be cut are arranged radially at the end of the axial hole of the workpiece 2 to be processed, the upper end surface 3 of the axial hole of the workpiece 2 to be processed is adjusted to be parallel to the machine tool worktable, and the center line 4 of the axial hole of the workpiece 2 to be processed is adjusted to coincide with the center of the machine tool worktable;

[0039] Initial cutting: The side of the auxiliary piece 1 to be cut close to the inner wall of the shaft hole is the part to be removed 5, and the part to be removed 5 is cut along the depth direction of the shaft hole to obtain the cut auxiliary piece 6 and form an initial cutting surface, and the curvature of the arc parallel to the radial direction of the shaft hole of the initial cutting surface is the same as the curvature of the cross-sectional circle at the end of the shaft hole;

[0040] Rough machining: measure the maximum distance between the initial cutting surfaces of the two cut auxiliary parts 6 to obtain the current end diameter 13 of the shaft hole; calculate the single-side machining allowance 14 according to the drawing size 12 and the current end diameter 13 of the shaft hole, and measure the taper of the shaft hole. If the deviation between the taper value and the theoretical value is less than 10%, it is determined that the current cutting parameters are correct, and the subsequent rough cutting parameters are calculated according to the single-side machining allowance 14, and the shaft hole is cut multiple times;

[0041] Finishing: After the last rough cutting is completed, measure whether the taper of the shaft hole is consistent with the theoretical value. If not, adjust the cutting parameters to make the machine tool cut at a uniform and stable speed. Remove the machining allowance after rough cutting through one finishing process, so that the measured diameter 13 of the shaft hole end is consistent with the drawing size 12, and remove the cut auxiliary part 6.

[0042] In the above-mentioned shaft hole processing method, when preparing for processing, at least two opposite auxiliary parts 1 to be cut are radially arranged at the end of the shaft hole of the workpiece 2 to be processed, so as to facilitate the measurement of the inner diameter of the shaft hole. Through the initial cutting, the to-be-removed part 5 of the auxiliary part 1 to be cut is removed, so that the curvature of the arc parallel to the radial direction of the shaft hole of the initial cutting surface is the same as the curvature of the cross-sectional circle at the end of the shaft hole. By measuring the maximum distance between the initial cutting surfaces of the two cut auxiliary parts 6, the current diameter 13 of the shaft hole end can be obtained. The single-sided machining allowance 14 is calculated by the drawing size 12 and the current diameter 13 of the shaft hole end, and the taper of the shaft hole is measured. If the deviation between the taper value and the theoretical value is less than 10%, it is determined that the current cutting processing parameters are correct, and the subsequent rough cutting processing parameters are calculated based on the single-sided machining allowance 14, and the shaft hole is cut multiple times. After the last rough cutting is completed, in order to avoid the machine tool slide extending too long to affect the cutting accuracy and quality, before the fine cutting, measure the taper of the shaft hole again to see if it is consistent with the theoretical value. If it is not consistent, adjust the cutting parameters to make the machine tool cut at a uniform and stable speed. Through one fine cutting, remove the machining allowance after the rough cutting, so that the measured diameter 13 of the shaft hole end is consistent with the drawing size 12, and ensure that the taper of the shaft hole after fine machining meets the machining requirements. Finally, remove the cut auxiliary part 6. This shaft hole machining method is easy to operate, and the taper of the machined shaft hole is easy to control, which can ensure that the taper of the shaft hole meets the requirements. It solves the problem that when machining the shaft hole of a vertical mining machine, the surface machining quality of the product shaft hole is poor and the qualified rate is low due to the large amount of machining in the depth direction of the shaft hole.

[0043] It is understandable that the auxiliary piece to be cut 1 and the cut auxiliary piece 6 refer to the same part. For ease of understanding, the auxiliary piece to be cut 1 and the cut auxiliary piece 6 are named before and after being cut. Figure 1-Figure 5As shown, in the subsequent rough machining and finishing steps, when the shaft hole is cut, the side surface of the cut auxiliary part 6 close to the inner wall of the shaft hole is also cut, so that after each cutting, the curvature of the arc on the side surface of the cut auxiliary part 6 parallel to the radial direction of the shaft hole is the same as the curvature of the cross-sectional circle at the end of the shaft hole, which is convenient for measuring the maximum distance between the sides of the two relative cut auxiliary parts 6 to achieve the measurement of the diameter 13 of the end of the shaft hole.

[0044] like Figure 5 As shown, in one embodiment, during fine machining, after the last rough cutting is completed, it is measured whether there are local high points on the inner side of the shaft hole and uneven taper of the shaft hole caused by local overcutting. If there are, the cutting parameters are adjusted to further improve the stability of the machine tool, and then fine machining is performed; if not, the parameters are kept unchanged, and finally a fine machining is performed to remove the machining allowance and machine the diameter 13 of the shaft hole end to be consistent with the drawing size 12. Optionally, when adjusting the fine machining cutting parameters, a small feed and high speed mode is used for machining to ensure stable cutting, so that the taper of the shaft hole is uniform and the surface roughness meets the requirements.

[0045] like Figure 1-Figure 7 As shown, in one embodiment, the shaft hole processing method further comprises the steps of:

[0046] Trial assembly: Perform trial assembly on the shaft to be assembled and the shaft hole to determine whether the shaft hole needs to be ground.

[0047] Furthermore, in order to improve the assembly effect between the shaft hole and the shaft to be assembled, in one of the embodiments, after trial assembly, if the distance from the upper end face 3 at the shaft hole to the upper end face of the shaft is less than a specified value, the corresponding thickness of material on the upper end face of the shaft hole is removed; if the distance from the upper end face 3 at the shaft hole to the upper end face of the shaft is greater than a specified value, the corresponding thickness of material in the inner cavity of the shaft hole is removed.

[0048] Furthermore, in order to test the processing effect of the shaft hole and the shaft to be assembled, after the shaft hole and the shaft to be assembled are assembled, the gap between the shaft hole and the upper end of the shaft is the upper gap 15, and the gap between the shaft hole and the lower end of the shaft is the lower gap 16. The upper gap 15, the lower gap 16 and the end face spacing 17 between the upper end face 3 at the shaft hole and the upper end face of the shaft are measured. If the upper gap 15, the lower gap 16 and the end face spacing 17 are all less than the corresponding specified values, the shaft hole processing is qualified.

[0049] like Figure 3-Figure 7 As shown, in order to improve the accuracy of the measurement result of the end diameter 13 of the shaft hole, in one embodiment, when measuring the end diameter 13 of the shaft hole during rough machining and fine machining, the maximum distance between the initial cutting surfaces of each pair of the cut auxiliary parts 6 is measured at least twice and the average is taken as the current end diameter 13 of the shaft hole.

[0050] Alternatively, if Figure 1-Figure 7 As shown, in order to further improve the accuracy of the measurement result of the diameter 13 of the end portion of the shaft hole, during processing preparation, an even number of auxiliary parts 1 to be cut that are opposite to each other are radially arranged at the end portion of the shaft hole of the workpiece 2 to be processed; when measuring the diameter 13 of the end portion of the shaft hole during rough processing and fine processing, the inner diameter measuring tool 7 is used to measure the maximum distance between each pair of the auxiliary parts to be cut 1 or the cut auxiliary parts 6 in turn and take the average, so as to realize the measurement of the shaft hole in different diameter directions, so that the measurement result of the diameter 13 of the end portion of the shaft hole is more accurate.

[0051] Optionally, during processing preparation, two cutting aids 1 are radially arranged at the end of the axial hole of the workpiece 2 to be processed, and the first cutting aid 1 and the second cutting aid 1 are arranged at 90°; when measuring the diameter 13 of the end of the axial hole during rough processing and fine processing, the inner diameter measuring tool 7 is used to measure the maximum distance between the first and second cutting aids 1 or the cut aids 6 in turn and take the average value, so as to improve the measurement accuracy, reduce the number of operations, and improve the measurement efficiency.

[0052] like Figure 5 , Figure 6 As shown, in one embodiment, when measuring the taper of the shaft hole, the measuring dial is installed at the lower end of the machine tool slide, the machine tool slide is moved in the depth direction of the shaft hole, and the movement amount of the slide in the depth direction is read 10, and the change amount along the radial direction of the shaft hole is read by the change of the pointer of the measuring dial, and the single-sided taper of the shaft hole is calculated. Optionally, the measuring dial is a dial indicator, and the pointer of the dial indicator is retractable. As the machine tool slide moves in the depth direction of the shaft hole, the change amount of the radius in the radial direction of the shaft hole can be read by the change amount of the pointer extension.

[0053] Optionally, the measuring dial is placed horizontally at the lower end of the machine tool ram, and the pointer is pressed to the zeroing point 9, which is the first position 8 of the dial. The machine tool creates a new coordinate system here, and the reading of the measuring dial is set to 0. On this basis, the machine tool ram is moved a certain distance in the depth direction of the shaft hole, and the dial reaches the second position 11. The radius change in the radial direction of the shaft hole can be read by measuring the change in the pointer of the dial, and then the taper of the shaft hole can be calculated by the movement of the ram in the depth direction 10 and the change in the pointer of the measuring dial.

[0054] Furthermore, in order to make the measurement result of the shaft hole taper more accurate and the taper in all directions of the shaft hole more uniform, in one embodiment, the measuring dial is rotated 90°, 180° or 270° relative to the shaft hole and the shaft hole taper is repeatedly measured and the average value is taken to obtain the change in the current shaft hole taper in the radial direction of the shaft hole.

[0055] like Figure 1-Figure 7As shown, in one embodiment, the required diameter of the shaft hole of the workpiece to be processed is 660mm, the maximum allowable dimensional deviation is 0.10mm, the starting depth is 1615mm, the final depth is 2615mm, the roughness requirement is Ra1.6, and the taper requirement is 1:8-0.999:8; the maximum extension of the machine tool slide used is 2700mm. During processing preparation, the auxiliary part 1 to be cut is a welding block, and the height of the auxiliary part 1 to be cut is selected to be 15mm-30mm, and the width is 70mm-110mm. Four auxiliary parts 1 to be cut are welded to the end face of the shaft hole of the workpiece 2 to be processed in pairs along the radial direction of the shaft hole by spot welding. The side of the auxiliary part 1 to be cut close to the inner wall of the shaft hole exceeds the inner edge of the shaft hole by 2mm-5mm to ensure that there is enough part 5 to be removed for cutting. When welding, using spot welding instead of full welding can avoid local hard spots or local deformation of the workpiece 2 to be processed due to long-term heating, and reduce welding defects such as undercut. When placing the workpiece 2 on the machine tool table, use a square box, jack and other tools to support the workpiece, and adjust the upper end surface of the workpiece 2 to be parallel to the machine tool table by adjusting the extension amount of each jack; use jaws, pressure plates and other tools to clamp the workpiece, and adjust the center line 4 of the shaft hole of the workpiece 2 to the center of the lathe table by adjusting the extension amount of each jaw, so as to facilitate subsequent processing and measurement operations. During rough cutting, the single-side allowance of the shaft hole is processed to 1.5mm-2mm through multiple cutting, which is used to be cut during fine processing.

[0056] Furthermore, during trial assembly, the conical surface of the shaft to be assembled is coated with powdered reagent 18, and after the shaft is placed in the shaft hole, the upper gap 15, the lower gap 16, and the end face spacing 17 between the upper end face 3 at the shaft hole and the upper end face of the shaft are measured, and the residual surface reagent 18 is detected after the shaft is taken out. If the following situations occur, it means that the spindle hole is not properly processed and needs to be polished: the upper gap 15 is greater than 0.05mm, the end face spacing 17 exceeds the theoretical range, and the powdered reagent 18 on the shaft surface changes unevenly, indicating that there are high points inside the shaft hole or the diameter of the shaft hole opening is not suitable. Optionally, the reagent 18 is red lead powder.

[0057] In one embodiment, the size of the auxiliary part 1 to be cut meets the operating space requirement of the inner diameter measuring tool 7, so as to measure the diameter of the shaft hole using the inner diameter measuring tool 7. Optionally, the inner diameter measuring tool 7 is an inner diameter micrometer.

[0058] The present invention also provides a workpiece having an axial hole obtained by the above-mentioned axial hole processing method. The axial hole of the workpiece has uniform taper, high processing accuracy and good processing quality.

[0059] The present invention also provides an assembly method, wherein the workpiece shaft hole obtained by the shaft hole processing method as described above is assembled with the shaft to be assembled. During assembly, the surface of the shaft to be assembled is cleaned, the shaft to be assembled is frozen, and the shrinkage rate of the shaft to be assembled is controlled to obtain sufficient interference during assembly; after the freezing is completed and the frost on the surface is wiped off, the shaft to be assembled is placed in the shaft hole, and when the temperature returns to room temperature, the shaft and the shaft hole form an interference fit. The above-mentioned assembly method meets the interference requirement for assembly between the shaft and the shaft hole at room temperature by freezing the shaft to be assembled and controlling the shrinkage rate. Optionally, liquid nitrogen is used to freeze the shaft to be assembled, and the shrinkage rate is controlled to be 0.60mm-0.75mm.

[0060] Furthermore, before assembly, a stop assembly is installed below the shaft hole to limit the amount of extension of the shaft relative to the shaft hole. After the temperature of the shaft returns to room temperature, the stop assembly is removed to complete the assembly.

[0061] Alternatively, if Figure 7 As shown, the stop assembly includes a stop block 19 and a stop rod 20. The stop rod 20 is installed below the shaft hole before assembly. The stop block 19 of a certain height is placed on the stop rod 20 to detect and limit the amount of the shaft extending relative to the shaft hole, thereby ensuring the success rate of assembly. After the temperature of the shaft returns to the ambient temperature, the stop rod 20 and the stop block 19 are removed to complete the assembly.

[0062] In the above-mentioned shaft hole processing method, when preparing for processing, at least two opposite auxiliary parts 1 to be cut are radially arranged at the end of the shaft hole of the workpiece 2 to be processed, so as to facilitate the measurement of the inner diameter of the shaft hole. Through the initial cutting, the to-be-removed part 5 of the auxiliary part 1 to be cut is removed, so that the curvature of the arc parallel to the radial direction of the shaft hole of the initial cutting surface is the same as the curvature of the cross-sectional circle of the end of the shaft hole. By measuring the maximum distance between the initial cutting surfaces of the two cut auxiliary parts 6, the current diameter 13 of the end of the shaft hole can be obtained. According to the drawing size 12 and the current diameter 13 of the end of the shaft hole, the single-sided machining allowance 14 is calculated, and the taper of the shaft hole is measured. If the deviation between the taper value and the theoretical value is less than 10%, it is determined that the current cutting processing parameters are correct, and the subsequent rough cutting processing parameters are calculated according to the single-sided machining allowance 14, and the shaft hole is cut multiple times. After the last rough cutting is completed, in order to avoid the machine tool slide extending too long to affect the cutting accuracy and quality, before the fine cutting, measure the taper of the shaft hole again to see if it is consistent with the theoretical value. If it is not consistent, adjust the cutting parameters to make the machine tool cut at a uniform and stable speed. Through one fine cutting, remove the machining allowance after the rough cutting, so that the measured diameter 13 of the shaft hole end is consistent with the drawing size 12, and ensure that the taper of the shaft hole after fine machining meets the machining requirements. Finally, remove the cut auxiliary part 6. This shaft hole machining method is easy to operate, and the taper of the machined shaft hole is easy to control, which can ensure that the taper of the shaft hole meets the requirements. It solves the problem that when machining the shaft hole of a vertical mining machine, the surface machining quality of the product shaft hole is poor and the qualified rate is low due to the large amount of machining in the depth direction of the shaft hole.

[0063] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for machining a shaft hole, characterized in that: The shaft hole processing method comprises: Processing preparation: at least two opposite auxiliary parts to be cut are arranged radially at the end of the axial hole of the workpiece to be processed, the upper end surface of the axial hole of the workpiece to be processed is adjusted to be parallel to the machine tool worktable, and the center line of the axial hole of the workpiece to be processed is adjusted to coincide with the center of the machine tool worktable; Initial cutting: The side of the auxiliary piece to be cut close to the inner wall of the shaft hole is the part to be removed. The part to be removed is cut along the depth direction of the shaft hole to obtain the cut auxiliary piece and form an initial cutting surface. The curvature of the arc parallel to the radial direction of the shaft hole of the initial cutting surface is the same as the curvature of the cross-section circle at the end of the shaft hole; Rough machining: measure the maximum distance between the initial cutting surfaces of the two cut auxiliary parts to obtain the current end diameter of the shaft hole; calculate the single-side machining allowance according to the drawing size and the current end diameter of the shaft hole, and measure the taper of the shaft hole. If the deviation between the taper value and the theoretical value is less than 10%, it is determined that the current cutting parameters are correct, and the subsequent rough cutting parameters are calculated according to the single-side machining allowance, and the shaft hole is cut multiple times; Finishing: After the last rough cutting is completed, measure whether the taper of the shaft hole is consistent with the theoretical value. If not, adjust the cutting parameters to make the machine tool cut at a uniform and stable speed. Remove the machining allowance after rough cutting through one finishing process, so that the measured diameter of the shaft hole end is consistent with the drawing size, and remove the cut auxiliary parts.

2. The shaft hole machining method according to claim 1, characterized in that: The shaft hole processing method further comprises the following steps after finishing: Trial assembly: Perform trial assembly on the shaft to be assembled and the shaft hole to determine whether the shaft hole needs to be ground.

3. The shaft hole machining method according to claim 2, characterized in that: After trial assembly, if the distance from the upper end surface of the shaft hole to the upper end surface of the shaft is less than the specified value, remove the corresponding thickness of material from the upper end surface of the shaft hole; if the distance from the upper end surface of the shaft hole to the upper end surface of the shaft is greater than the specified value, remove the corresponding thickness of material from the inner cavity of the shaft hole.

4. The shaft hole machining method according to claim 1, characterized in that: When measuring the end diameter of the shaft hole during rough machining and fine machining, the maximum distance between the initial cutting surfaces of each pair of the cut auxiliary parts is measured at least twice and the average is taken as the current end diameter of the shaft hole.

5. The shaft hole machining method according to claim 1, characterized in that: During processing preparation, an even number of auxiliary parts to be cut are arranged in pairs along the radial direction at the end of the axial hole of the workpiece to be processed; when measuring the diameter of the end of the axial hole during rough processing and fine processing, the maximum distance between each pair of the auxiliary parts to be cut or the cut auxiliary parts is measured in turn with an inner diameter measuring tool and the average is taken.

6. The shaft hole machining method according to claim 1, characterized in that: When measuring the taper of the shaft hole, install the measuring dial on the lower end of the machine tool slide, move the machine tool slide along the depth direction of the shaft hole, and read the movement amount in the slide depth direction. Read the change amount along the shaft hole radial direction through the change of the pointer of the measuring dial, and calculate the single-sided taper of the shaft hole.

7. The shaft hole machining method according to claim 6, characterized in that: Rotate the measuring dial 90°, 180° or 270° relative to the shaft hole, repeat the measurement of the shaft hole taper, and take the average value to obtain the current shaft hole taper.

8. The shaft hole machining method according to any one of claims 1 to 7, characterized in that: The size of the auxiliary part to be cut meets the operating space requirement of the inner diameter measuring tool.

9. A workpiece, characterized in that: A shaft hole is produced by the shaft hole processing method as described in any one of claims 1 to 7.

10. An assembly method, characterized in that: The workpiece shaft hole obtained by the shaft hole processing method as described in any one of claims 1 to 7 is assembled with the shaft to be assembled. During assembly, the surface of the shaft to be assembled is cleaned, the shaft to be assembled is frozen and the shrinkage rate of the shaft to be assembled is controlled to obtain sufficient interference during assembly; after the freezing is completed and the surface frost is wiped off, the shaft to be assembled is placed in the shaft hole, and when the temperature returns to room temperature, the shaft and the shaft hole form an interference fit.

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