Maintenance method for knife rest shaft of large pulverizer

Abstract

The invention discloses a maintenance method for a knife rest shaft of a large pulverizer, which belongs to the technical field of industrial equipment maintenance and comprises the following steps: placing the knife rest shaft on a gantry machining center machine tool; the dial indicator is installed on a main shaft of a machining center, coarse adjustment and fine adjustment are conducted on the position of a tool rest shaft, and it is ensured that the dial indicator jumps within a set range; positioning the tool rest shaft after rough adjustment and fine adjustment through a centering rod and a machine tool coordinate axis which are mounted in a machine tool in advance, and confirming a machining original point of the tool rest shaft; assembling and transforming holes, grooves and welding chamfers on the surface of the tool rest shaft according to the planned technical drawing at the machining original point; integrally assembling and welding the modified tool rest shaft and a tool rest shaft accessory which is machined in advance to finish maintenance; the tool rest shaft of an existing plastic pulverizer is maintained, on the basis that rotation of the tool rest shaft is not affected, the concentricity requirement of the tool rest shaft is met, centrifugal force generated when the tool rest shaft rotates is reduced, and potential production safety hazards are reduced.

Description

Technical Field

[0001] The invention relates to a maintenance method for a large-scale crusher cutter shaft, belonging to the technical field of industrial equipment maintenance. Background Art

[0002] The existing plastic crusher has a heavy workload and a long service life, so the cutter shaft is prone to breakage, and the cost of replacing the entire cutter shaft is high. Due to the special nature of the cutter shaft and the large centrifugal force generated during rotation, the axial and radial tolerance requirements for the entire shaft are very high.

[0003] Since the workshop does not have a large lathe, and the entire tool holder shaft and tool holder bracket are welded together to form a whole and cannot be disassembled, the overall maintenance process requires many considerations and the maintenance is extremely difficult. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a maintenance method for the tool holder shaft of a large crusher. The tool holder shaft of an existing plastic crusher is repaired to ensure the concentricity requirements of the tool holder shaft without affecting the rotation of the tool holder shaft, reduce the centrifugal force generated by the tool holder shaft itself when it rotates, and reduce production safety hazards.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a maintenance method for a large-scale pulverizer cutter shaft, comprising: Place the tool holder axis on the gantry machining center machine; Install the dial indicator on the spindle of the machining center, and make coarse and fine adjustments to the position of the tool holder axis to ensure that the dial indicator runout is within the set range; The tool post axis after coarse and fine adjustment is positioned by the centering rod and machine coordinate axis pre-installed in the machine tool to confirm the machining origin of the tool post axis; At the processing origin, the surface of the tool holder shaft is assembled and modified with holes, grooves and welding chamfers according to the planned technical drawings; The modified tool holder shaft is assembled and welded with the pre-processed tool holder shaft accessories as a whole to complete the maintenance.

[0006] Furthermore, the dial indicator is installed on the spindle of the machining center, and the position of the tool holder shaft is roughly and finely adjusted to ensure that the dial indicator runout is within the set range, including: Move the machine tool spindle to the shaft diameter position on the left side of the integral tool holder shaft, and measure from left to right with the integral pull gauge to ensure that the outer side of the entire left shaft surface is covered. Use a copper rod to tap the left and right sides of the tool holder shaft to adjust the position, and ensure that the dial indicator jump is within 10 wires. Move the machine tool spindle to the shaft diameter position on the left side of the integral tool holder shaft, and measure from left to right with the integral pull-out gauge to ensure that the upper end surface of the entire shaft surface on the left side is covered. Adjust the height by adding or removing spacers to ensure that the dial indicator runout is within 10 wires. Move the machine tool to the left and right sides of the tool holder shaft and the tool holder connecting block, and measure at two symmetrical points on the center of the outer side of the connected shaft diameter. Use a copper rod to tap the left and right sides of the tool holder shaft to fine-tune the position and ensure that the dial indicator jump is within 10 wires. Move the machine tool to measure at two symmetrical points on the left and right sides of the tool holder shaft, at the center of the upper end surface of the connected shaft diameter connected to the tool holder connecting block. Fine-tune the height by adding or removing spacers to ensure that the dial indicator runout is within 10 wires.

[0007] Furthermore, the positioning of the tool rest axis after coarse adjustment and fine adjustment by means of a centering rod and a machine tool coordinate axis pre-installed in the machine tool to confirm the machining origin of the tool rest axis includes: By finding two points symmetrical to the center axis of the tool holder axis in the Y-axis position and taking the center of the two points, the z position of the center axis of the tool holder axis in the machine tool is confirmed; By finding two points symmetrical to the center axis of the tool holder axis in the Z-axis direction and taking the center of the two points, the y position of the center axis of the tool holder axis in the machine tool is confirmed; On the premise that the center axes y and z of the tool holder axis have been confirmed, install the matching tool and move it to the processing section to determine the x position of the processing origin.

[0008] Furthermore, the assembly modification of the surface of the tool holder shaft with holes, grooves and welding chamfers according to the planned technical drawings includes: processing a first assembly flat keyway, a second assembly flat keyway, a first assembly inner hole and a first welding chamfer according to the planned technical drawings.

[0009] Furthermore, the method further comprises: When machining the first assembly flat keyway and the second assembly flat keyway, increase the assembly tolerance by 0.03mm; When machining the first assembly inner hole, reduce the assembly tolerance by 0.05mm.

[0010] Furthermore, the processing method of the tool holder shaft accessory includes: High frequency quenching treatment, processing of the third assembly flat keyway, the first assembly cylinder, the second welding chamfer, and additional processing of the assembly guide flat key, the assembly throat clamp and the circumferential ring sleeve welding connection plate.

[0011] Furthermore, the processing method of the tool holder shaft accessory further includes: In the bearing assembly area, the tool holder shaft accessories are subjected to high-frequency quenching treatment based on the strength measurement of the entire shaft; When machining the third assembly flat keyway, increase the assembly tolerance by 0.03mm; When machining the first assembly cylinder, increase the assembly tolerance by 0.05mm; When machining and assembling the guide flat key, the guide taper is machined; When processing and assembling the throat clamp, the internal thread is processed and a fixed gap of 5-10mm is reserved.

[0012] Furthermore, the step of integrally assembling the modified tool holder shaft with the pre-processed tool holder shaft accessories includes: Place the guide flat key in the first flat keyway and the second flat keyway of the original tool holder shaft after modification, and fix the guide flat key by assembling a throat hoop to stably embrace the tool holder shaft; Take out the tool holder shaft accessory pre-soaked in liquid nitrogen, and match the first assembly inner hole of the tool holder shaft with the first assembly cylinder of the tool holder shaft accessory under the guidance of the first guide chamfer of the tool holder assembly according to the preset drawing requirements; Wait for the tool holder shaft and tool holder shaft accessories to return to normal temperature, allow the first assembly cylinder to have an interference fit with the first assembly inner hole, and remove the assembly throat hoop and guide flat key; Take out the conventional flat key pre-soaked in liquid nitrogen, and knock the conventional flat key into the first assembly flat keyway, the second assembly flat keyway, and the third assembly flat keyway according to the preset drawing requirements; Wait for the conventional flat key to return to normal temperature, and allow the conventional flat key to have interference fit with the first assembly flat keyway, the second assembly flat keyway, and the third assembly flat keyway; According to the preset drawing requirements, weld the first weld. After the first weld is welded, grind it flat with the louver blades, then place the circumferential ring welding connecting plate to the set position, weld the second weld, the third weld, the fourth weld, the fifth weld, and the sixth weld. Among them, the first weld is the connection between the tool holder shaft and the tool holder shaft accessory, the second weld is the left side of the connection between the circumferential ring welding connecting plate and the tool holder shaft, the third weld is the right side of the connection between the circumferential ring welding connecting plate and the tool holder shaft accessory, the fourth weld is the welding between the tool holder shaft accessory and the tool holder bracket, the fifth weld and the sixth weld are the first flat keyway, the second flat keyway and the conventional flat key welding.

[0013] Furthermore, the method also includes: inspecting the repaired tool holder shaft, including cooling it at room temperature and transferring it to a machining center to check concentricity, and testing it on a machine.

[0014] Furthermore, the inspection of the repaired tool holder shaft also includes: Check the concentricity by using a CNC dial indicator to ensure that the axial and radial runout of the tool holder shaft is within 10 wires.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a maintenance method for a large-scale crusher tool holder shaft. Through the maintenance of the tool holder shaft, the replacement cost is greatly reduced. The tool holder shaft after maintenance fully meets the use requirements, and at the same time improves the overall process and technical level of the workshop; the tool holder shaft repaired by this method has the following advantages during maintenance: 1. Through the positioning and milling processing of the gantry machining center, the space for the original tool holder shaft modification is greatly reduced, ensuring the strength of the original tool holder shaft.

[0016] 2. The original milling position of the tool holder shaft passed the first tool holder bracket. This was mainly because the initial torsion was generated between the tool holder shaft accessories processed later and the first tool holder bracket, which reduced the stress at the weld and greatly improved the strength of the maintenance, making it durable.

[0017] 3. The tool holder shaft and tool holder shaft accessories are processed through assembly guide chamfering and guide flat keys, which greatly reduces the difficulty of assembly.

[0018] 4. The tool holder shaft accessory is matched with the first assembly inner hole of the tool holder shaft through the first assembly cylinder to form an axial connection, and the conventional flat key is connected with the first assembly flat keyway, the second assembly flat keyway and the third assembly flat keyway in the tool holder shaft accessory to form a radial connection. The circumferential ring welding connecting plate is annularly reinforced with the tool holder shaft and the tool holder shaft accessory, and is welded to form a circumferential connection. Axial connection, radial connection, circumferential connection, the trinity, finally forms a three-dimensional mesh structure, and the final overall strength is better than the original structure.

[0019] 5. Through the principle of liquid nitrogen cooling, the tool holder shaft and tool holder shaft accessories, and the flat keyway and conventional flat key can achieve interference fit, so that elastic pressure is generated between the two, eliminating assembly clearance, improving assembly accuracy, and improving overall strength.

[0020] 6. After the interference fit, the corresponding position is welded again. Due to the basis of interference fit and the welding position is equally divided and annular welding, the welding deformation is extremely small, the integrity of the workpiece after welding is excellent, and the strength of the tool holder shaft after welding fully meets the requirements.

[0021] 7. The replacement cost of a whole set of tool holder shaft is high and the processing cycle is long. In order to shorten the production downtime and reduce the production and operation costs, the maintenance method of the present invention has a short transformation time and low transformation costs, which greatly reduces the cost and reduces the downtime of the crusher. At the same time, the tool holder shaft after maintenance is equal to or even better than the original tool holder shaft in terms of product structure and overall strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the overall assembly of the tool holder shaft, tool holder bracket, and tool holder provided by an embodiment of the present invention; Figure 2 is a schematic diagram of the position where the tool holder shaft is broken provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of adjusting a broken tool holder shaft in a machining center provided by an embodiment of the present invention; Figure 4 1 is a schematic diagram of the principle of finding the center of the tool holder axis provided by an embodiment of the present invention; Figure 5 This is a schematic diagram of the original tool holder shaft processing provided by the embodiment of the present invention. Figure 1 ; Figure 6 This is a schematic diagram of the original tool holder shaft processing provided by the embodiment of the present invention. Figure 2 ; Figure 7 is a schematic diagram of a tool holder shaft accessory provided by an embodiment of the present invention; Figure 8 is a schematic diagram of a bearing seat area provided by an embodiment of the present invention; Fig. 9 is a schematic diagram of an assembly guide flat key provided by an embodiment of the present invention; Fig.10 is a schematic diagram of assembling a throat hoop provided by an embodiment of the present invention; Fig.11 is a schematic diagram of a circumferential ring-sleeve welded connection plate provided in an embodiment of the present invention; Fig.12 is a schematic diagram of the flat keyway matching provided by an embodiment of the present invention; Fig.13 is a schematic diagram of the coordination of the throat clamp provided by an embodiment of the present invention; Fig.14 It is a schematic diagram of assembling the original tool holder shaft and tool holder shaft accessories provided by an embodiment of the present invention; Fig.15 This is a schematic diagram of a conventional flat key assembly provided by an embodiment of the present invention; Fig.16 The overall welding part provided by the embodiment of the present invention is schematically shown in FIG. Figure 1 ; Fig.17 The overall welding part provided by the embodiment of the present invention is schematically shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0024] Embodiment 1: This embodiment introduces a maintenance method for a large-scale crusher blade shaft, comprising: Place the tool holder axis on the gantry machining center machine; Install the dial indicator on the spindle of the machining center, and make coarse and fine adjustments to the tool holder axis to ensure that the dial indicator runout is within the set range; Adjust the tool post axis after coarse and fine adjustment by using the centering rod and machine coordinate axis pre-installed in the machine tool to confirm the machining origin of the tool post axis; At the machining origin, the tool holder axis is modified according to the planned technical drawings; The modified tool holder shaft is assembled as a whole with the pre-processed tool holder shaft accessories to complete the maintenance.

[0025] The contents involved in the above embodiment are described below in conjunction with a preferred embodiment.

[0026] The practical problem solved by the present invention is that, when repairing the existing tool holder shaft of a plastic crusher, the concentricity requirement of the tool holder shaft must be ensured without affecting the rotation of the tool holder shaft, so as to reduce the centrifugal force generated by the body when the tool holder shaft rotates.

[0027] The invention mainly consists of five steps: adjusting the position of the tool holder shaft on the machine tool, modifying the original tool holder shaft, processing tool holder shaft accessories, integrally assembling the tool holder shaft body, and inspecting the tool holder shaft after maintenance.

[0028] The assembly of the integral tool holder shaft, tool holder bracket and tool holder is as follows: Figure 1 shown.

[0029] The position where the tool holder shaft breaks, such as Figure 2 shown.

[0030] 1. Adjust the position of the tool holder axis on the machine tool.

[0031] like Figure 3 shown.

[0032] 1. Place the tool holder shaft on the workbench of the gantry machining center.

[0033] 2. Coarse adjustment 1: Install the dial indicator on the spindle of the machining center, such as Figure 3 As shown, move the machine tool spindle to the shaft diameter position on the left side of the integral tool holder shaft, and pull the table from left to right to ensure that the outer side of the entire shaft surface on the left side is covered, that is, Figure 3 Adjust section X1 on the left side of the machine tool, check the runout of the dial indicator, if it is more than 10 wires, use a copper rod to knock on the left and right sides of the tool holder shaft to adjust the position, and finally ensure that the runout of the dial indicator is within 10 wires.

[0034] 3. Coarse adjustment 2: Install the dial indicator on the spindle of the machining center, such as Figure 3 As shown, move the machine tool spindle to the shaft diameter position on the left side of the integral tool holder shaft, and pull the table from left to right to ensure that the upper end surface of the entire shaft surface on the left side is covered, that is, Figure 3Adjust section Z1 on the left side of the machine tool and check the runout of the dial indicator. If the runout is more than 10 threads, adjust the height by adding or reducing spacers to ensure that the runout of the dial indicator is within 10 threads.

[0035] 4. Fine adjustment 1: After the rough adjustment, install the dial indicator on the spindle of the machining center. Figure 3 As shown, move the machine tool to the position respectively: first, select any point at the center position of the outer side surface of the connected shaft diameter connected to the tool holder connecting block on the left side of the integral tool holder axis, and then, under the premise that the spindle Y and Z directions do not move, move the X direction to the right side of the broken shaft, and measure at the center position of the outer side surface of the connected shaft diameter connected to the right tool holder connecting block. The measuring point is Figure 3 Check the left point A and the right point B in the dial indicator, if the jump is more than 10 wires, use the copper rod to knock on the left and right sides of the tool holder shaft to adjust the position, and finally ensure that the jump of the dial indicator is within 10 wires.

[0036] 5. Fine adjustment 2: Install the dial indicator on the spindle of the machining center, such as Figure 3 As shown, move the machine tool to the position respectively: first, select any point at the center of the upper end face of the connected shaft diameter connected to the tool holder connecting block on the left side of the integral tool holder axis, and then, under the premise that the spindle Y and Z directions do not move, move the X direction to the right side of the broken shaft, and measure at the center of the upper end face of the connected shaft diameter connected to the right tool holder connecting block. The measuring point is Figure 3 Check the upper end point C and the upper end point D in the dial indicator, and if the runout is more than 10 threads, adjust the height by adding or reducing spacers to ensure that the runout of the dial indicator is within 10 threads.

[0037] 6. Confirm the position z of the center axis of the tool holder shaft, such as Figure 4 As shown, move the machine tool to the side of the machining section E, and use the centering rod to randomly find a point y1 on the tool holder axis corresponding to section E. Then keep the z-axis of the machining center stationary, and find the position y2 corresponding to y1 by adjusting the positions of the x-axis and y-axis of the machining center. After centering, the z position of the center axis of the tool holder axis in the machine tool can be confirmed.

[0038] 7. Confirm the position y of the center axis of the tool holder shaft, such as Figure 4 As shown, move the machine tool to the side of the machining section E, and use the centering rod to randomly find a point z1 on the tool holder axis corresponding to section E. Then keep the y-axis of the machining center stationary, and adjust the positions of the x-axis and z-axis of the machining center to find the position z2 corresponding to z1. After taking the center of z1 and z2, the y position of the center axis of the tool holder axis in the machine tool can be confirmed.

[0039] 8. Confirm the machining origin of the tool holder axis. On the premise that the center axes y and z of the tool holder axis have been confirmed, install the matching tool on the machining center and move the tool to the relatively complete section on the side of the machining section e. At this time, the x position in the machine tool position is the starting point of our machining feed direction. At this time, the x, y, and z positions of the machining origin are all determined.

[0040] 2. Modification of the original tool holder shaft.

[0041] 1. After the machining origin of the tool holder axis is determined, it is processed according to the planned technical drawings, such as Figure 5 , Figure 6 shown.

[0042] 2. When processing the tool holder shaft, it is necessary to process the first assembly flat keyway and the second assembly flat keyway. The first assembly flat keyway and the second assembly flat keyway need to increase the assembly tolerance by 0.03mm to prepare for the subsequent interference fit.

[0043] 3. When processing the tool holder shaft, it is necessary to process the first assembly inner hole. The first assembly inner hole needs to reduce the assembly tolerance by 0.05mm to prepare for the subsequent interference fit.

[0044] 4. When processing the tool holder shaft, it is necessary to process the first welding chamfer to prepare for subsequent welding.

[0045] 3. Processing of tool holder shaft accessories.

[0046] 1. Processing is carried out according to the planned technical drawings through workshop lathes and machining centers. Figure 7 shown.

[0047] 2. During the processing of tool holder shaft accessories, high-frequency quenching treatment (Rockwell hardness HRC22-24) is carried out in the bearing assembly area according to the strength measurement of the entire shaft, which can greatly improve the overall rigidity, wear resistance and service life. The position of the bearing assembly area is as follows: Figure 8 shown.

[0048] 3. When processing the tool holder shaft accessories, it is necessary to process the third assembly flat keyway. The third assembly flat keyway needs to increase the assembly tolerance by 0.03mm to prepare for the subsequent interference fit.

[0049] 4. When processing the tool holder shaft accessories, it is necessary to process the first assembly cylinder. The first assembly cylinder needs to increase the assembly tolerance by 0.05mm to prepare for the subsequent interference fit.

[0050] 5. When processing the tool holder shaft accessories, it is necessary to process the second welding chamfer to prepare for subsequent welding.

[0051] 6. When machining the tool holder shaft accessories, it is necessary to additionally machine 5 assembly guide flat keys. Fig. 9As shown, a guide taper needs to be machined in preparation for subsequent assembly.

[0052] 7. When machining the tool holder shaft accessories, an additional set of assembly hose clamps needs to be machined. The drawing is as follows: Fig.10 As shown, internal threads need to be processed and a fixed gap of 5-10mm needs to be left to prepare for subsequent assembly.

[0053] 8. When machining tool holder shaft accessories, it is necessary to additionally machine an additional set of circumferential ring welding connecting plates, such as Fig.11 As shown, there are 6 pieces in total, ready for subsequent welding.

[0054] 4. Assemble the tool holder shaft as a whole.

[0055] 1. Place the guide flat key in the first flat keyway and the second flat keyway of the original tool holder shaft after modification, and prepare for the installation of the tool holder shaft accessories for guide assembly, such as Fig.12 shown.

[0056] 2. Fix the throat hoop stably around the tool holder shaft, and stabilize the guide key to reinforce the original tool holder shaft to avoid dislocation during installation of tool holder shaft accessories, such as Fig.13 shown.

[0057] 3. Soak the tool holder shaft accessories in liquid nitrogen. Through low temperature control, the tool holder shaft accessories will shrink to a certain extent in liquid nitrogen to prepare for the interference fit in subsequent assembly.

[0058] 4. Take the tool holder shaft accessory out of the liquid nitrogen. According to the drawing requirements, under the guidance of the first guide chamfer of the tool holder assembly, the first assembly inner hole of the original tool holder shaft is matched with the first assembly cylinder of the tool holder shaft accessory, such as Fig.14 shown.

[0059] 5. Wait for the original tool holder shaft and tool holder shaft accessories to return to normal temperature, so that the interference fit between the two can be completely released, and remove the assembly throat clamp and guide flat key.

[0060] 6. Soak the conventional flat key in liquid nitrogen. Through low temperature control, the conventional flat key will shrink to a certain extent in liquid nitrogen, preparing for the interference fit in the subsequent assembly.

[0061] 7. Take the conventional flat key out of the liquid nitrogen and knock it into the first assembly flat keyway, the second assembly flat keyway, and the third assembly flat keyway according to the drawing requirements. Fig.15 shown.

[0062] 8. Wait for the conventional flat key to return to normal temperature, so that the interference fit between the conventional flat key and the first assembly flat keyway, the second assembly flat keyway, and the third assembly flat keyway can be completely released.

[0063] 9. According to the requirements of the drawings, reasonably weld the first weld. After the first weld is welded, grind it flat with the louver blades, then place the circumferential ring welding connecting plate to a reasonable position, and reasonably weld the second weld, the third weld, the fourth weld, the fifth weld, and the sixth weld. The first weld is the connection between the tool holder shaft and the tool holder shaft accessory. The second weld is the connection between the circumferential ring welding connecting plate and the tool holder shaft on the left side. The third weld is the connection between the circumferential ring welding connecting plate and the tool holder shaft accessory on the right side. Weld 4 is the welding place between the tool holder shaft accessory and the tool holder bracket. The fifth and sixth welds are the first flat keyway, the second flat keyway and the conventional flat key welding place. The specific welding positions are as follows: Fig.16 , Fig.17 shown.

[0064] 5. Inspection of tool holder shaft after maintenance.

[0065] 1. After the welded tool holder shaft is cooled at room temperature for 12 hours, it is transferred to the machining center and the concentricity is checked by means of a CNC dial indicator. After the test, the concentricity meets the standard, and the axial and radial runout of the tool holder shaft is within 10 wires, which fully meets the assembly technical requirements for the free clearance of the self-aligning ball bearing during the later assembly.

[0066] Repair completed, tried on machine, passed.

[0067] Through the repair of the tool holder shaft, the replacement cost was greatly reduced. The repaired tool holder shaft fully meets the use requirements and at the same time improves the overall process and technical level of the workshop.

[0068] The tool holder shaft that was repaired this time has the following advantages during maintenance: 1. Through the positioning and milling processing of the gantry machining center, the space for the original tool holder shaft modification is greatly reduced, ensuring the strength of the original tool holder shaft.

[0069] 2. The original milling position of the tool holder shaft passed the first tool holder bracket. This was mainly because the initial torsion was generated between the tool holder shaft accessories processed later and the first tool holder bracket, which reduced the stress at the weld and greatly improved the strength of the maintenance, making it durable.

[0070] 3. The tool holder shaft and tool holder shaft accessories are processed through assembly guide chamfering and guide flat keys, which greatly reduces the difficulty of assembly.

[0071] 4. The tool holder shaft accessories are connected to the first assembly inner hole of the tool holder shaft through the first assembly cylinder to form an axial connection through the mortise and tenon connection, and the conventional flat key is connected to the first assembly flat keyway in the tool holder shaft, the second assembly flat keyway and the third assembly flat keyway in the tool holder shaft accessories through the key pin saddle connection to form a radial connection. The circumferential ring sleeve welding connecting plate is annularly reinforced with the tool holder shaft and the tool holder shaft accessories, and is welded to form a circumferential connection. Axial connection, radial connection, circumferential connection, the trinity, finally forms a three-dimensional mesh structure, and the final overall strength is better than the original structure.

[0072] 5. Through the principle of liquid nitrogen cooling, the tool holder shaft and tool holder shaft accessories, and the flat keyway and conventional flat key can achieve interference fit, so that elastic pressure is generated between the two, eliminating assembly clearance, improving assembly accuracy, and improving overall strength.

[0073] 6. After the interference fit, the corresponding position is welded again. Due to the basis of interference fit and the welding position is equally divided and annular welding, the welding deformation is extremely small, the integrity of the workpiece after welding is excellent, and the strength of the tool holder shaft after welding fully meets the requirements.

[0074] 7. The manufacturer quoted a replacement cost of 100,000 yuan for the entire tool holder shaft, and the processing cycle takes 2 months. Because the equipment is in 24-hour continuous operation, in order to shorten the production downtime and reduce production and operation costs, the workshop formulated a maintenance plan based on the existing processing equipment. From the confirmation of the plan to the end of the maintenance, all maintenance and installation were completed in just one week. The total estimated cost of the transformation was 20,000 yuan, which greatly reduced the cost and reduced the downtime of the crusher. At the same time, the repaired tool holder shaft is equal to or even better than the original tool holder shaft in terms of product structure and overall strength.

[0075] 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 technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A maintenance method for a large-scale crusher blade shaft, characterized in that: include: Place the tool holder axis on the gantry machining center machine; Install the dial indicator on the spindle of the machining center, and make coarse and fine adjustments to the position of the tool holder axis to ensure that the dial indicator runout is within the set range; The tool post axis after coarse and fine adjustment is positioned by the centering rod and the machine coordinate axis pre-installed in the machine tool to confirm the machining origin of the tool post axis; At the processing origin, the surface of the tool holder shaft is assembled and modified with holes, grooves and welding chamfers according to the planned technical drawings; The modified tool holder shaft is integrally assembled and welded with the pre-processed tool holder shaft accessories to complete the repair.

2. The maintenance method of the large-scale crusher blade shaft according to claim 1 is characterized in that: The dial indicator is installed on the spindle of the machining center, and the position of the tool holder shaft is roughly and finely adjusted to ensure that the dial indicator runout is within the set range, including: Move the machine tool spindle to the shaft diameter position on the left side of the integral tool holder shaft, and measure from left to right with the integral pull gauge to ensure that the outer side of the entire left shaft surface is covered. Use a copper rod to tap the left and right sides of the tool holder shaft to adjust the position, and ensure that the dial indicator jump is within 10 wires. Move the machine tool spindle to the shaft diameter position on the left side of the integral tool holder shaft, and measure from left to right with the integral pull-out gauge to ensure that the upper end surface of the entire shaft surface on the left side is covered. Adjust the height by adding or removing spacers to ensure that the dial indicator runout is within 10 wires. Move the machine tool to the left and right sides of the tool holder shaft and the tool holder connecting block, and measure at two symmetrical points on the center of the outer side of the connected shaft diameter. Use a copper rod to tap the left and right sides of the tool holder shaft to fine-tune the position and ensure that the dial indicator jump is within 10 wires. Move the machine tool to measure at two symmetrical points on the left and right sides of the tool holder shaft, at the center of the upper end surface of the connected shaft diameter connected to the tool holder connecting block. Fine-tune the height by adding or removing spacers to ensure that the dial indicator runout is within 10 wires.

3. The maintenance method of the large-scale crusher blade shaft according to claim 1, characterized in that: The method of positioning the tool rest axis after coarse adjustment and fine adjustment by using the centering rod and the machine tool coordinate axis pre-installed in the machine tool to confirm the machining origin of the tool rest axis includes: By finding two points symmetrical to the center axis of the tool holder axis in the Y-axis position and taking the center of the two points, the z position of the center axis of the tool holder axis in the machine tool is confirmed; By finding two points symmetrical to the center axis of the tool holder axis in the Z-axis direction and taking the center of the two points, the y position of the center axis of the tool holder axis in the machine tool is confirmed; On the premise that the center axes y and z of the tool holder axis have been confirmed, install the matching tool and move it to the processing section to determine the x position of the processing origin.

4. The maintenance method of the large-scale crusher blade shaft according to claim 1, characterized in that: The assembly modification of the surface of the tool holder shaft with holes, grooves and welding chamfers according to the planned technical drawings includes: processing the first assembly flat keyway, the second assembly flat keyway, the first assembly inner hole and the first welding chamfer according to the planned technical drawings.

5. The maintenance method of the large-scale pulverizer blade shaft according to claim 4, characterized in that: The method further comprises: When machining the first assembly flat keyway and the second assembly flat keyway, increase the assembly tolerance by 0.03mm; When machining the first assembly inner hole, reduce the assembly tolerance by 0.05mm.

6. The maintenance method of the large-scale pulverizer blade shaft according to claim 1, characterized in that: The processing method of the tool holder shaft accessory comprises: High frequency quenching treatment, processing of the third assembly flat keyway, the first assembly cylinder, the second welding chamfer, and additional processing of the assembly guide flat key, the assembly throat clamp and the circumferential ring sleeve welding connection plate.

7. The maintenance method of the large-scale pulverizer blade shaft according to claim 6, characterized in that: The processing method of the tool holder shaft accessory also includes: In the bearing assembly area, the tool holder shaft accessories are subjected to high-frequency quenching treatment based on the strength measurement of the entire shaft; When machining the third assembly flat keyway, increase the assembly tolerance by 0.03mm; When machining the first assembly cylinder, increase the assembly tolerance by 0.05mm; When machining and assembling the guide flat key, the guide taper is machined; When processing and assembling the throat clamp, the internal thread is processed and a fixed gap of 5-10mm is reserved.

8. The maintenance method of the large-scale pulverizer blade shaft according to claim 7, characterized in that: The step of integrally assembling the modified tool holder shaft and the pre-processed tool holder shaft accessories comprises: Place the guide flat key in the first flat keyway and the second flat keyway of the original tool holder shaft after modification, and fix the guide flat key by assembling a throat hoop to stably embrace the tool holder shaft; Take out the tool holder shaft accessory pre-soaked in liquid nitrogen, and match the first assembly inner hole of the tool holder shaft with the first assembly cylinder of the tool holder shaft accessory under the guidance of the first guide chamfer of the tool holder assembly according to the preset drawing requirements; Wait for the tool holder shaft and tool holder shaft accessories to return to normal temperature, allow the first assembly cylinder to have an interference fit with the first assembly inner hole, and remove the assembly throat hoop and guide flat key; Take out the conventional flat key pre-soaked in liquid nitrogen, and knock the conventional flat key into the first assembly flat keyway, the second assembly flat keyway, and the third assembly flat keyway according to the preset drawing requirements; Wait for the conventional flat key to return to normal temperature, and allow the conventional flat key to have interference fit with the first assembly flat keyway, the second assembly flat keyway, and the third assembly flat keyway; According to the preset drawing requirements, weld the first weld. After the first weld is welded, grind it flat with the louver blades, then place the circumferential ring welding connecting plate to the set position, weld the second weld, the third weld, the fourth weld, the fifth weld, and the sixth weld. Among them, the first weld is the connection between the tool holder shaft and the tool holder shaft accessory, the second weld is the left side of the connection between the circumferential ring welding connecting plate and the tool holder shaft, the third weld is the right side of the connection between the circumferential ring welding connecting plate and the tool holder shaft accessory, the fourth weld is the welding between the tool holder shaft accessory and the tool holder bracket, the fifth weld and the sixth weld are the first flat keyway, the second flat keyway and the conventional flat key welding.

9. The maintenance method of the large-scale pulverizer blade shaft according to claim 1, characterized in that: The method further comprises: inspecting the tool holder shaft after repair, including cooling it at room temperature, transferring it to a machining center to check the concentricity, and testing it on a machine.

10. The maintenance method of the large-scale pulverizer blade shaft according to claim 1, characterized in that: The inspection of the repaired tool holder shaft also includes: Check the concentricity by using a CNC dial indicator to ensure that the axial and radial runout of the tool holder shaft is within 10 wires.

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