Machining process of bridge shaft

Abstract

The invention discloses a bridge shaft machining technology which comprises the steps that oxide skin of a bridge shaft blank is removed, a bridge shaft piece is placed at the position of a middle hollow main shaft and clamped by double chucks at the position of the middle hollow main shaft, and the surfaces of the two ends of the bridge shaft piece are turned through two sets of opposite cutters. After turning is completed, the axle shaft piece is placed in a turning and milling combined machining center to be milled, then the milled axle shaft piece is placed in a numerical control external grinding machine to be ground, after machining is completed, the axle shaft piece enters the turning and milling combined machining center again to be drilled and tapped, and finally cleaning is conducted. In the prior art, the two ends of the axle shaft part are machined in an exchange mode, the overall machining efficiency is low, the machining benchmark of the two ends of the axle shaft part cannot be guaranteed, and follow-up use of the axle shaft part is affected, certain procedures are simplified, the machining efficiency of the axle shaft part is reduced, double-end turning can be conducted on the axle shaft part, the machining benchmark of the two ends of the axle shaft part is guaranteed, and the machining efficiency is improved. And the influence on the subsequent machining precision is reduced.

Description

Technical Field

[0001] This invention relates to the field of bridge shaft machining technology, and in particular to a bridge shaft machining process. Background Technology

[0002] As a core component of the transmission system, the bridge shaft has very high requirements for accuracy such as coaxiality and overall roundness. In traditional machining processes, it is generally processed in steps.

[0003] The common machining process for bridge shafts involves fixing the workpiece on a set of lathes. The end of the workpiece that is not yet being machined is clamped and limited by the chuck and center rest on the lathe. Then, the workpiece is rotated and the cutting tool is moved to perform rough machining on the workpiece end. After completion, the workpiece is disassembled and the two ends are swapped. The rough-machined end is clamped and the other end of the workpiece is machined. After completing the rough machining of the workpiece, the above operation is repeated when performing the finish machining.

[0004] This method of alternating clamping and machining can easily lead to the accumulation of machining positioning errors on the bridge shaft. As a result, it is impossible to ensure that the machining reference at both ends of the bridge shaft is the same during the overall machining process. This can easily result in excessive errors in the precision of the structure machined on the bridge shaft, affecting the overall use of the bridge shaft and resulting in low overall machining efficiency. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a processing technology for bridge shafts.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: 1. A processing technology for a bridge shaft, comprising the following steps:

[0007] Step 1: The bridge axle blank is made of 40Cr material. After quenching and tempering, a single or double allowance is left. The oxide scale on the surface of the bridge axle blank is removed to initially form the bridge axle part.

[0008] Step 2: A centrally located hollow spindle (3) is installed inside the CNC lathe. The bridge shaft (1) is passed through the centrally located hollow spindle (3). A tool setting device is set on the tool post inside the CNC lathe so that the two ends of the bridge shaft (1) to be machined are located outside the centrally located hollow spindle (3). The double chuck (2) inside the centrally located hollow spindle (3) clamps the two ends of the outer surface of the bridge shaft (1) respectively. The tool is set with the bridge shaft (1) through the tool setting device.

[0009] Step 3: Start the central hollow spindle to rotate the bridge shaft component. The cutting tools at opposite ends of the central hollow spindle perform turning machining on the surfaces at both ends of the bridge shaft component.

[0010] Step 4: Place the bridge axle component that has been turned into a three-jaw chuck in the milling and turning machining center for clamping, and then perform milling on the bridge axle component.

[0011] Step 5: Place the milled bridge shaft into a CNC cylindrical grinding machine and grind the entire surface of the bridge shaft.

[0012] Step 6: Place the bridge shaft component into the three-jaw chuck in the milling and turning machining center for clamping, and then drill and tap holes in the bridge shaft component.

[0013] Step 7: Lift the axle assembly and move it to the cleaning machine. The axle assembly is then transported by conveyor belt to the cleaning machine for cleaning and drying. After cleaning, it is packaged.

[0014] Preferably, the length of the bridge axle component is reserved with a margin of 1 to 1.5 mm on one side or a margin of 2.5 to 3 mm on both sides.

[0015] Preferably, the tool setting device includes a tool setting instrument and a transition component mounted on the tool holder. The transition component includes a tool holder located on the tool holder and a shaft slidably mounted on the tool holder. A buffer portion is provided at the end of the shaft away from the tool setting instrument. A return spring is sleeved on the outside of the shaft between the tool holder and the buffer portion. A contact portion is provided at the end of the shaft facing the tool setting instrument.

[0016] Preferably, in step one, the oxide scale removal of the bridge shaft component is carried out by placing the bridge shaft blank on the center rest of the lathe, fixing one end of the bridge shaft blank with the three-jaw chuck of the lathe, and rotating the bridge shaft blank around its own central axis, and manually grinding the surface of the bridge shaft blank using a pneumatic grinding head.

[0017] Preferably, in step two, the bridge axle component is lifted by a crane and manually pushed into the centrally located hollow main shaft.

[0018] Preferably, in step three, the turning process includes cutting the outer circle, end face, and orifice corner of the flange face of the axle component, as well as the end face, orifice corner, and oil seal hole of the other end.

[0019] Preferably, the milling process includes creating a keyway on the end face of the axle component using a milling cutter and milling the edges on the surface of the axle component.

[0020] Preferably, in step six, the cleaning machine uses multi-process equipment, including equipment for placing dehydrating rust-preventive oil, equipment for spraying volatile rust-preventive oil, and a compressed blower, which are arranged in sequence.

[0021] Preferably, the specific cleaning of the axle components includes the following steps:

[0022] Step 1: Hoist the bridge axle components onto the conveyor belt of the cleaning machine, and drive them into the tank containing the dehydrating and rust-preventing oil for immersion cleaning.

[0023] Step 2: After the bridge axle component is carried out of the dehydrating and rust-preventive oil box by the conveyor belt, the bridge axle component enters the processing area for spraying volatile rust-preventive oil. The volatile rust-preventive oil is sprayed onto the surface of the bridge axle component through the nozzle.

[0024] Step 3: After passing through the processing area of ​​the volatile rust-preventive oil, the axle component enters the compressor blower, where the compressor blows air to remove excess rust-preventive oil from the surface of the axle component.

[0025] Preferably, a nylon rod is provided between the two sets of clamps to support and guide the portion of the bridge shaft component located inside the central hollow spindle.

[0026] The beneficial effects of this invention are:

[0027] 1. Leaving a single or double allowance on the surface of the bridge shaft component can increase the tolerance for errors in subsequent processing, providing room for correction in subsequent processes. This can effectively offset errors in the process and ensure that the final dimensions meet the design requirements. At the same time, personnel use pneumatic grinding heads to remove the oxide scale from the surface of the bridge shaft component. Manual operation has the advantages of flexibility and strong applicability. Moreover, the surface after the oxide scale is removed by the grinding head is smoother, reducing the problem of pits or pinholes on the surface of the bridge shaft component.

[0028] 2. The bridge shaft component is placed using a centrally located hollow spindle. The centrally located hollow spindle has double chucks that clamp both ends of the bridge shaft component. Two sets of cutting tools perform turning machining on both ends of the bridge shaft component. The machining of both ends of the bridge shaft component can be performed on the same axis. Compared with existing technologies, this invention eliminates the need for manual switching of clamping during the machining of both ends of the bridge shaft component. The centrally located hollow spindle, in conjunction with the internal double chucks, supports the bridge shaft component, allowing two sets of cutting tools to machine both ends of the bridge shaft component under the same datum. This improves the datum accuracy of the bridge shaft component surface machining and avoids the problem of deviations in the machining datum caused by re-clamping after machining one end.

[0029] 3. After milling the axle components using a mill-turn machining center, they are ground using a CNC cylindrical grinding machine. The mill-turn machining center replaces the traditional "milling machine + lathe + drilling machine" method, reducing the number of machines used for machining the axle components, lowering equipment maintenance costs, and reducing the number of times the axle components are handled, thus reducing the workload for personnel. The mill-turn machining center provides better reference accuracy and faster processing efficiency for each process of machining the axle components. The cylindrical grinding machine can further polish the surface of the axle components after they have passed through the mill-turn machining center, improving the dimensional accuracy of the surface and controlling the form and position tolerances, resulting in more stable surface quality of the axle components.

[0030] 4. By setting a tool setting device on the tool holder, the tool is set via the tool setting device and the bridge shaft component, eliminating the need for manual tool setting, reducing the workload of personnel, and improving the accuracy of machining the bridge shaft component. The tool setting device is equipped with a transition component, which provides buffering and limiting. The tool and the tool setting device do not have direct contact during tool setting, which can effectively reduce the wear and damage caused by direct contact between the tool and the tool setting device. Attached Figure Description

[0031] Figure 1 This is a partial structural diagram illustrating the bridge shaft component placed on a centrally located hollow main shaft according to one embodiment of the present invention;

[0032] Figure 2 This is a flowchart illustrating the processing technology of bridge axle components according to one embodiment of the present invention.

[0033] Reference numerals: 1. Bridge shaft; 2. Chuck; 3. Centrally located hollow spindle. Detailed Implementation

[0034] The following description is merely a preferred embodiment of the present invention, and the scope of protection is not limited to this embodiment. All technical solutions that fall within the scope of the present invention should be considered within the scope of protection of the present invention. It should also be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

[0035] It should be noted that in this document, relational terms such as first and second, or "connecting plate one, connecting plate two," are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0036] The directional terms mentioned in this embodiment, such as "up," "down," "left," and "right," are merely used to help those skilled in the art understand the relationships between various features or parts in conjunction with the accompanying drawings.

[0037] In this embodiment, unless otherwise explicitly specified and limited, the terms "connection" and "fixed" should be interpreted broadly. For example, "fixed" can be a fixed connection, a detachable connection, or an integral part; 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 components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] like Figures 1 to 2As shown, a machining process for a bridge shaft includes the following steps:

[0039] Step 1: Select 40Cr material for the bridge shaft blank. First, the blank undergoes quenching and tempering. Then, after cooling, the blank is lifted by a crane and moved to a conventional lathe. One end of the blank is secured by a three-jaw chuck. The center rest supports the middle of the blank, while the end furthest from the chuck is held in place by a center pin. The chuck rotates, causing the blank to rotate synchronously around its central axis. A pneumatic grinder is used to manually polish the surface of the blank to remove oxide scale. After polishing, the blank is held in place by the crane, and the three-jaw chuck on the lathe is controlled. After loosening one end of the bridge shaft blank, the operator removes the blank and reverses it, inserting the end with the removed oxide scale into a three-jaw chuck. The chuck clamps the blank, allowing the operator to grind the unpolished areas previously clamped by the chuck. This removes the oxide scale from the entire surface of the bridge shaft blank, initially forming bridge shaft component 1. A 2.5-3 mm allowance is reserved at both ends of bridge shaft component 1. The surface finish and allowance on both sides will be optimized in subsequent processing steps. In this embodiment, the heat treatment is performed according to the technical methods conventionally used by those skilled in the art, involving a dual heat treatment of quenching and high-temperature tempering to improve the overall performance of bridge shaft component 1, increasing its strength and toughness.

[0040] Step Two: After the axle component 1 is ground to remove the oxide scale, personnel use a crane to lift the axle component 1 and move it to the central hollow spindle 3 inside the CNC lathe. The axle component 1 is then manually pushed into the central hollow spindle 3. The double chucks 2 at both ends of the central hollow spindle 3 are controlled by bidirectional hydraulic cylinders, simultaneously clamping both ends of the axle component 1. The axle component 1 is held in place by two sets of ejector pins at each end, working in conjunction with the central hollow spindle 3 to limit its movement. It should be noted that the double chucks 2 and the bidirectional hydraulic cylinders are set at an angle. When the driving end of the bidirectional hydraulic cylinder moves, it will drive the double chucks 2 along the central hollow spindle. The radial movement of the collet 3 clamps the portion of the bridge shaft 1 located within the central hollow spindle 3. When the collet 2 is rotated, it can drive the bridge shaft 1 to rotate together. In this embodiment, the central hollow spindle 3 is mounted on a CNC lathe. A rolling nylon bar is provided between the two collets 2 to support and guide the portion of the bridge shaft 1 located within the central hollow spindle 3, reducing the workload when pushing the bridge shaft 1 to one end of the central hollow spindle 3. A movable tool post is installed in the CNC lathe, and a tool setting device is provided on the tool post. The tool is set with the bridge shaft via the tool setting device. In this embodiment, the tool setting device includes a tool setter fixed on the tool post. The tool setter and transition components include a tool holder integrally formed with the tool post and a slidably mounted shaft on the tool holder. The shaft traverses the tool holder, and its translational direction is consistent with the central axis of the tool post. At opposite ends of the shaft outside the tool holder, a buffer portion and a contact portion are integrally formed. The buffer portion is located at the end of the shaft furthest from the tool setter, and a return spring is sleeved on the outside of the shaft. The return spring is located between the tool holder and the buffer portion. When the tool post moves, it drives the shaft to move, causing the buffer portion to contact the bridge shaft, which in turn pushes the shaft to move horizontally on the tool holder. The shaft then contacts the detection end of the tool setter via the contact portion, eliminating the need for direct contact with the tool and reducing the risk of damage to the tool setter. The positioning spring can push the shaft to reset when the tool holder reset shaft does not contact the bridge shaft component. It should be noted that in this embodiment, the tool positioning adopts a combination of rough positioning and fine positioning. During rough positioning, the bridge shaft component pushes the shaft to give a sensing signal to the tool setting device. During fine positioning, it gives another set of sensing signals to the tool setting device. The tool setting device collects the above sensing signals and sends them to the CNC lathe system to form tool setting data and performs numerical compensation itself. Compared with manual tool setting, the accuracy is higher, making the numerical reference after subsequent tool cutting more accurate. For tool setting of bridge shaft machining, the tool setting device preferably adopts the WT-20A, WT-20C, or WT-25 / 30 type.

[0041] Step 3: The centrally located hollow spindle 3 begins to rotate the bridge shaft component 1. The operator controls the movement of the tools installed at opposite ends of the centrally located hollow spindle 3. It should be noted that the tools at opposite ends of the centrally located hollow spindle 3 are respectively installed on two tool posts inside the CNC lathe. The left and right ends of the bridge shaft component 1 located outside the centrally located hollow spindle 3 are cut by the tool in the finish turning mode. Specifically, the outer circle of the flange surface, the corner of the hole and the oil seal hole on the bridge shaft component 1 are machined to achieve the cutting of the two ends of the bridge shaft component 1 without changing the clamping position, ensuring the reference accuracy of the two ends. At the same time, after the above parts of the bridge shaft component 1 are machined, the reserved allowance at both ends of the bridge shaft component 1 is removed.

[0042] Step 4: After turning both ends of the bridge shaft component 1, release the double chuck 2 and push the bridge shaft component 1 out of the central hollow spindle 3. During the pushing process, use a crane to lift the bridge shaft component 1 and then move it into the mill-turn machining center. Clamp one end of the bridge shaft component 1 using the three-jaw chuck in the mill-turn machining center. Milling is then performed using the reference surface machined on the central hollow spindle 3 of the bridge shaft component 1 as a reference. Specifically, the milling is performed using the tool magazine in the mill-turn machining center. The tool magazine is set to a milling cutter to create a keyway on the end face of the bridge shaft 1 and to mill the surface of the bridge shaft 1. Since both ends of the bridge shaft 1 are machined synchronously, the deviation of the reference lines at both ends is small, which improves the accuracy of milling on the bridge shaft 1. In this embodiment, after clamping one end of the bridge shaft 1 in the mill-turn machining center, the surface part of the bridge shaft 1 that has not been machined at the central hollow spindle 3 can be further machined by adjusting the tool magazine in the mill-turn machining center to a turning tool.

[0043] Step 5: Remove the milled bridge axle 1 from the milling and turning machining center, transport it to the CNC cylindrical grinding machine by crane, and place it inside the CNC cylindrical grinding machine. The chuck inside the CNC cylindrical grinding machine clamps the bridge axle 1, and then the entire surface of the bridge axle 1 is ground to further improve the overall precision dimensions of the bridge axle 1.

[0044] Step Six: After grinding, the bridge shaft component 1 is hoisted back to the mill-turn machining center by a crane. One end of the bridge shaft component 1 is fixed by a three-jaw chuck. The tool magazine in the mill-turn machining center is set to a drill bit. The bridge shaft component 1 remains stationary, and the drill bit begins to drill holes in the flange of the bridge shaft component 1. After drilling each hole, the tool magazine is set to a tap. The tap is then used to tap the holes in the farad plate of the bridge shaft component 1.

[0045] Step Seven: After completing the fabrication of the threaded holes on axle component 1, personnel use a crane to lift axle component 1 from the milling and turning machining center and transport it to the conveyor belt of the cleaning machine. The cleaning machine includes an area for placing dehydrating rust-preventive oil, an area for spraying volatile rust-preventive oil, and an area for placing a compressed blower. These three areas are set up sequentially. First, axle component 1 is lifted onto the conveyor belt of the cleaning machine and carried by the conveyor belt into the tank containing dehydrating rust-preventive oil for immersion cleaning. Immersion cleaning allows for a better and more comprehensive cleaning of axle component 1. Next, after being immersed in dehydrating rust-preventive oil, axle component 1 is transported by the conveyor belt into the tank for spraying volatile rust-preventive oil. In the rust-preventive oil processing area, a medium-volatile rust-preventive oil is sprayed onto the surface of the axle component 1 through a spray nozzle. This allows some impurities on the surface of the axle component 1 to be removed by the impact of the volatile rust-preventive oil. Finally, the axle component 1 is transported by a conveyor belt to the compression blower. In this embodiment, there are six sets of compression blowers arranged in sequence at the same level. The compression blowers blow air collectively, and the air pressure is adjusted to allow some of the rust-preventive oil to remain on the surface of the axle component 1, while the rest is blown away. After the axle component 1 is conveyed out of the compression blower area, personnel use a crane to lift the axle component 1 to the packaging area for packaging.

[0046] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the scope of protection of the present invention.

Claims

1. A machining process for a bridge shaft, comprising the following steps: Step 1: The bridge axle blank is made of 40Cr material. After quenching and tempering, a single or double allowance is left. The oxide scale on the surface of the bridge axle blank is removed to initially make the bridge axle part (1). Step 2: A centrally located hollow spindle (3) is installed inside the CNC lathe. The bridge shaft (1) is passed through the centrally located hollow spindle (3). A tool setting device is set on the tool post inside the CNC lathe so that the two ends of the bridge shaft (1) to be machined are located outside the centrally located hollow spindle (3). The double chuck (2) inside the centrally located hollow spindle (3) clamps the two ends of the outer surface of the bridge shaft (1) respectively. The tool is set with the bridge shaft (1) through the tool setting device. Step 3: Start the central hollow spindle (3) to start rotating the bridge shaft (1). The tools at both ends of the central hollow spindle (3) perform turning machining on the surfaces of both ends of the bridge shaft (1). Step 4: Place the bridge shaft part (1) that has been turned into a three-jaw chuck in the milling and turning machining center for clamping, and perform milling on the bridge shaft part (1). Step 5: Place the milled bridge shaft (1) into a CNC cylindrical grinding machine and grind the entire surface of the bridge shaft (1). Step 6: Place the bridge shaft part (1) into the three-jaw chuck in the milling and turning machining center for clamping, and drill and tap the bridge shaft part (1). Step 7: Lift the bridge axle component (1) and move it to the cleaning machine. The bridge axle component (1) is then transported by a conveyor belt to be cleaned and dried in the cleaning machine. After cleaning, it is packaged.

2. The processing technology for a bridge shaft according to claim 1, characterized in that, The length of the bridge axle component (1) is reserved with a margin of 1 to 1.5 mm on one side or a margin of 2.5 to 3 mm on both sides.

3. The processing technology for a bridge shaft according to claim 1, characterized in that, The tool setting device includes a tool setting instrument and a transition component mounted on a tool holder. The transition component includes a tool holder located on the tool holder and a shaft slidably mounted on the tool holder. A buffer portion is provided at the end of the shaft away from the tool setting instrument. A return spring is sleeved on the outside of the shaft between the tool holder and the buffer portion. A contact portion is provided at the end of the shaft facing the tool setting instrument.

4. The machining process for a bridge shaft according to claim 1, characterized in that, In step one, removing the oxide scale from the bridge shaft component (1) involves placing the bridge shaft blank on the center rest of a lathe, fixing one end of the bridge shaft blank with the three-jaw chuck of the lathe, and rotating the bridge shaft blank around its own central axis. The surface of the bridge shaft blank is then manually polished using a pneumatic grinding head.

5. The processing technology for a bridge shaft according to claim 1, characterized in that, In step two, the bridge axle component (1) is lifted by a crane and manually pushed into the central hollow main shaft (3).

6. The machining process for a bridge shaft according to claim 1, characterized in that, In step three, the turning process includes cutting the outer circle, end face, and orifice of the flange face of the bridge shaft (1) and the end face, orifice, and oil seal hole of the other end of the bridge shaft (1) with a cutting tool.

7. The machining process for a bridge shaft according to claim 1, characterized in that, The milling process includes creating a keyway on the end face of the bridge shaft component (1) using a milling cutter and milling the edges on the surface of the bridge shaft component (1).

8. The machining process for a bridge shaft according to claim 1, characterized in that, In step six shown, the cleaning machine uses multi-process equipment, including equipment for placing dehydrating rust-preventive oil, equipment for spraying volatile rust-preventive oil, and a compressed blower, which are set up in sequence.

9. The machining process for a bridge shaft according to claim 8, characterized in that, The specific cleaning of the bridge axle component (1) includes the following steps: Step 1: Hoist the bridge axle component (1) onto the conveyor belt of the cleaning machine, and drive it into the box containing the dehydrating and rust-preventing oil for immersion cleaning. Step 2: After the bridge axle component (1) is carried out of the dehydrating rust-preventive oil box by the conveyor belt, the bridge axle component (1) enters the processing area for spraying volatile rust-preventive oil. The volatile rust-preventive oil is sprayed onto the surface of the bridge axle component (1) through the nozzle. Step 3: After passing through the processing area of ​​volatile rust-preventive oil, the bridge axle component (1) enters the compressor blower. The compressor blows air to remove excess rust-preventive oil from the surface of the bridge axle component (1).

10. The machining process for a bridge shaft according to claim 1, characterized in that, A nylon rod is provided between the two sets of clamps (2) to support and guide the part of the bridge shaft (1) located inside the central hollow spindle (3).

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