A positioning processing method for large gears with double keyways at arbitrary angles

Abstract

The present invention relates to a positioning processing method for large gears with double keyways at arbitrary angles in the field of gear processing. First, a gear blank to be processed is prepared. The center of the gear blank is provided with a center hole. A reference surface tool is made on the surface of the gear blank to establish a reference surface that forms a fixed positional relationship with the starting keyway and starting tooth to be processed. Then, based on the positional relationship between the reference surface and the starting key and starting tooth, the position of the gear blank and the position of the reference surface relative to the working coordinate axis of the processing equipment are positioned and adjusted on a processing workbench for positioning processing. In the gear positioning processing method of the present invention, a reference surface tool is pre-made on the surface of the gear blank according to the structural requirements of the two-point gear. Then, based on the position requirements of the starting keyway and starting tooth, the position of the starting tooth and starting tooth relative to the reference surface is determined, thereby facilitating the positioning processing of the starting keyway and starting tooth, and achieving precise positioning processing of the mating gears without the need for repeated disassembly and assembly for alignment and marking processing.

Description

Technical Field

[0001] The present invention relates to the technical field of gear processing, and in particular to a positioning processing method for a large gear with double keyways at arbitrary angles. Background Art

[0002] The large gears on a two-point press require paired machining and installation to ensure synchronized meshing. Prior art methods for matching multiple keyways or large gears with multiple keyways typically involve machining one complete double-keyway gear and machining only the outer tooth grooves of the other gear, without machining the double keyways around the center hole. Assembly requires first assembling and adjusting the two large gears to mesh. Then, the corresponding keyways on the gear center holes are marked according to the positions of the unused keys at the crankshaft mounting point. The press is then disassembled and the keyways re-machined to the marked positions. This assembly and disassembly method is cumbersome and inaccurate, leading to deviations in the synchronized meshing of the gears after assembly and poor synchronization of the two-point press. Furthermore, if one of the gears becomes damaged after a period of use and requires replacement, the accuracy of the machining position is even more difficult to ensure. Consequently, these prior art gear machining methods result in poor interchangeability and versatility, complicating the assembly process for new machines and hindering accurate custom machining for subsequent gear repairs and replacements. Summary of the Invention

[0003] The present invention aims to solve the problems existing in the processing and installation methods of large gears on double-point presses in the prior art and provides a positioning processing method for double-keyway or multi-keyway gears to ensure the interchangeability and versatility of the gears and improve the efficiency of gear processing and assembly.

[0004] To achieve the above-mentioned purpose of the present invention, the present invention provides a positioning processing method for large gears with double keyways at arbitrary angles. First, a gear blank to be processed is prepared, and a center hole is provided in the center of the gear blank. It is characterized in that a reference surface tooling is made on the surface of the gear blank to establish a reference surface that forms a fixed positional relationship with the starting keyway and starting tooth to be processed. Then, according to the positional relationship between the reference surface and the starting key and starting tooth, the position of the gear blank and the position of the reference surface relative to the working coordinate axis of the processing equipment are positioned and adjusted on the processing workbench for positioning processing.

[0005] In the gear positioning processing method of the present invention, according to the structural requirements of the double-point gear, a reference surface tooling for positioning the starting keyway and the starting tooth is pre-made on the surface of the gear blank, and then according to the position requirements of the starting keyway and the starting tooth, the position of the starting tooth and the starting tooth relative to the reference surface is determined, which facilitates the positioning processing of the starting keyway and the starting tooth, and realizes the precise positioning processing of the paired gears without the need for repeated disassembly and assembly and marking processing.

[0006] To further achieve the purpose of the present invention, the positioning processing method of a large gear with double keyways at arbitrary angles of the present invention specifically includes the following steps: first, a gear blank to be processed is prepared, wherein the center of the gear blank is provided with a center hole;

[0007] Step 1: A reference surface tool is made on the surface of the gear blank. Two centrally symmetrical pins are fixed on the surface of the gear blank. The plane where the centerline of the pins is located is used as the reference plane. The position of the starting keyway midplane is determined by the closest position between the inner circumference of the center hole and the reference plane. Then, the processing position of the starting tooth is determined according to the position requirements of the starting keyway and the starting tooth for subsequent processing. The starting keyway midplane is the plane perpendicular to the key bottom of the keyway to be processed.

[0008] Step 2: Place the gear blank on the workbench of the wire cutting machine. Adjust the position of the workpiece relative to the workbench so that the reference surface is perpendicular or parallel to the Y-axis translation direction of the workbench to locate the position of the gear blank on the workbench. Then adjust the position of the workbench so that the center axis of the gear blank coincides with the origin of the wire cutting machine. Then, according to the input cutting pattern program, complete the cutting of each keyway in sequence starting from the starting keyway.

[0009] Step 3: Place the gear blank after wire cutting in the second step on the rotary worktable on the gear milling machine, adjust the center axis of the rotary worktable and the center axis of the gear blank to coincide to locate the position of the gear, and then adjust the reference surface and the main axis of the gear milling machine to be perpendicular; according to the position of the starting tooth determined in the first step, start milling the outer teeth of the gear in sequence.

[0010] In order to facilitate the accurate fixation of the pin of the reference surface tooling, in the first step, when making the reference surface tooling, two center-balanced fixing blocks are fixed on the surface of the gear blank. The fixing blocks are respectively provided with positioning holes. The positioning holes on the two positioning blocks are symmetrical with respect to the center hole of the gear blank. The pins are inserted into the positioning holes with interference fit and ensure that the two pins are symmetrical along the center of the gear blank.

[0011] As a preferred embodiment of the present invention, in step 1, the pins are located in the same diameter direction of the gear blank, and the midplane of the starting keyway coincides with the reference plane.

[0012] The keyway is positioned and processed according to the reference surface determined in the above preferred scheme. In the second step, when processing the keyway, when adjusting the position of the gear blank on the online cutting workbench, a dial indicator is pre-fixed on the molybdenum wire rack of the online cutting machine through a magnetic fixing seat, and then the gear blank is initially placed on the workbench so that the reference surface corresponding to the center line of the two pins is parallel to the Y-axis direction of the workbench. The workbench is translated and the angle of the gear blank is slightly adjusted so that when the gear blank is translated along the Y-axis, the outer sides of the two pins in the same direction measured on the dial indicator have the same reading, so as to confirm that the reference surface is parallel to the Y-axis.

[0013] The gear is processed according to the position of the starting key positioned on the reference surface determined in the above preferred solution. In the third step, when adjusting the position of the gear blank on the workbench, a dial indicator is fixed on the main shaft of the gear milling machine through a magnetic fixing seat, so that the measuring head of the dial indicator is radially aligned with the inner circumference of the center hole of the gear blank. The position of the gear blank is fine-tuned while rotating the workbench so that the workbench rotates 360 degrees and the reading of the dial indicator measuring the inner circumference of the center hole remains unchanged to confirm that the center of the center hole coincides with the rotation center of the workbench; then the angle of the workbench is rotated so that the reference surface corresponding to the center of the two pins is perpendicular to the main shaft of the gear milling machine, and then according to the angular difference between the starting tooth and the reference surface determined in the first step, the gear is started to be milled.

[0014] As another preferred method of the present invention, in step 1, the pins are positioned in the non-diametrical direction of the gear blank, and the midplane of the starting keyway is perpendicular to the reference plane. At this point, the centerlines of the two pins form an acute angle with the line connecting the center holes. The reference planes corresponding to the two pin centerlines are perpendicular to the midplane of the starting keyway and closest to each other, allowing the positioning of the starting keyway and starting tooth for machining. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of a large gear with double keyways.

[0016] Figure 2 This is a flow chart of Example 1 of the positioning processing method for large gears with double keyways at arbitrary angles according to the present invention.

[0017] Figure 3 This is a flow chart of Example 2 of the positioning processing method for large gears with double keyways at arbitrary angles according to the present invention. Implementation Method

[0018] by Figure 1 The processing of double keyway gear is combined as an example Figure 2 and Figure 3 The process shown in the figure details the gear processing method of the present invention. Figure 1 The gear shown has two keyways circumferentially arranged around the center hole. The first keyway machined is designated as starting keyway 1, and the first gear to be machined is designated as starting tooth 2. The angle between the two keyways of the two large gears used in a two-point press is α, and the angle between the starting keyway and the center of the tooth root or tooth tip of starting tooth 3 is β. In the following embodiment, a reference surface fixture is first fabricated on the surface of the gear blank. The relationship between the reference surface fixture and the coordinate axes of the machining tool, as well as the positional relationship between the reference surface and starting keyway 1 and starting tooth 2, are then determined on the worktable of the machining machine. The positions of the starting keyway and starting tooth are then determined, and the corresponding cutting process is performed. Example

[0019] Step 1, such as Figure 2As shown, first prepare the gear according to its size. Figure 2 The gear blank shown in a, then press Figure 2 At the position shown in b, a reference surface tooling is made on the surface of the gear blank. Specifically, two positioning blocks 3 are welded on the surface of the gear blank. A positioning hole is provided in the center of the positioning block 3. A pin 4 is inserted into the positioning hole with interference fit, and the axis of the pin 4 is perpendicular to the surface of the gear blank. The plane corresponding to the center line of the two pins 4 is the reference surface 5 ( Figure 2 b) The reference surface 5 is aligned with the Y axis. Then, the positional relationship between the starting key and starting tooth to be machined and the reference surface is determined to facilitate the machining of the keyway and teeth. In this embodiment, the position closest to the inner periphery of the center hole of the gear blank and the reference surface 5 is determined as the starting keyway 1. Figure 2 As shown in Figure C, since the reference surface 5 coincides with the diameter direction of the center hole, the midplane of the starting key 1 is determined to coincide with the reference surface 5, and the position on the reference surface (also the midplane) closest to the inner circumference of the center hole of one of the pins 3 is determined as the position of the starting key. The relative position of the starting key is then determined based on the angle β between the midplane of the starting key 1 and the root center (or tooth top center) of the starting tooth 2.

[0020] Step 2. When preparing to process the keyway on the wire cutting machine, in order to facilitate the reference surface as a reference, the gear blank to be processed is accurately positioned on the workbench. A dial indicator is pre-fixed on the molybdenum wire rack of the wire cutting machine through a magnetic fixing seat, and then the gear blank is initially placed on the workbench of the cutting machine. First, the reference surface 5 corresponding to the center line of the two pins 4 is roughly parallel to the Y-axis direction of the workbench when visually inspected. Then the workbench is translated and the angle of the gear blank is slightly adjusted so that when the gear blank is translated along the Y-axis with the workbench, the outer side readings of the generatrix of the two pins in the same position measured on the dial indicator are the same to confirm that the reference surface 5 is parallel to the Y-axis. At this point, the position of the gear blank on the workbench has been determined. Depending on the size and weight of the gear, the gear blank is fixed to the workbench using a positioning fixture if necessary. The workbench is translated along the X or Y axis to drive the gear blank to move so that the center hole of the gear blank is aligned with the position where the molybdenum wire of the wire cutting machine passes through. After tightening the molybdenum wire, the gear is translated by the translation workbench. The position of the workbench is adjusted by the reciprocating translation of the molybdenum wire along the X and Y axes in the center hole so that the center axis of the gear blank coincides with the marking origin of the wire cutting machine. Then, the cutting pattern program of the double keyway is input, starting from the starting keyway, and each keyway is cut in sequence.

[0021] Step 3: Milling machine, such as Figure 2d, place the gear blank after the second step of wire cutting on the rotary table of the gear milling machine, adjust the central axis of the rotary table and the central axis of the gear blank to coincide to locate the position of the gear blank, and then adjust the reference surface 5 to be perpendicular to the main shaft of the gear milling machine; the specific positioning adjustment method is: fix a dial indicator on the main shaft of the gear milling machine through a magnetic fixing seat, then translate the main shaft and adjust the angle of the dial indicator measuring head so that the measuring head of the dial indicator is radially aligned with the inner periphery of the center hole of the gear blank, and fine-tune the position of the gear blank while rotating the table to make The worktable rotates 360 degrees, and the dial indicator measures the inner circumference of the center hole, ensuring the reading remains constant, to confirm that the center of the center hole coincides with the worktable's rotational center. The worktable is then rotated until the reference surface 5, corresponding to the centers of the two pins 4, is perpendicular to the milling machine's spindle. At this point, the reference surface coincides with the Y-axis, the center axis of the gear blank coincides with the milling machine's coordinate origin, and the midplane of the starting keyway 1 coincides with the Y-axis. The worktable is rotated β degrees to position the starting tooth 2 for machining. Milling the gear from the starting tooth is continued according to the milling procedure until machining is complete. This completes the positioning and machining of the keyway and gear of the large double-keyway gear. Example

[0022] like Figure 3 As shown, the method for machining the keyway and teeth of a large double keyway gear in this embodiment is different from that in embodiment 1 in that the fixed position of the reference surface tooling on the gear surface is different: specifically, as shown in FIG. Figure 3 As shown in b, the two pins 4 and the positioning block 3 for inserting the pins 4 are located in the non-diametric direction of the gear blank surface. The center lines of the two pins 4 form an acute angle with the line connecting the center holes. The reference surface 5 corresponding to the center lines of the two pins 4 is perpendicular to a certain radius of the gear blank. At this time, the midplane of the starting keyway 1 is perpendicular to the reference surface 5 and the distance is the shortest. Therefore, the positions of the starting keyway 1 and the starting tooth 2 are determined for processing for subsequent positioning processing.

[0023] Step 1, such as Figure 3 As shown, first prepare the gear according to its size. Figure 3 The gear blank shown in a, then press Figure 3 At the position shown in b, a reference surface tooling is made on the surface of the gear blank. Specifically, two positioning blocks 3 are welded on the surface of the gear blank. A positioning hole is provided in the center of the positioning block 3. A pin 4 is inserted into the positioning hole with interference fit, and the axis of the pin 4 is perpendicular to the surface of the gear blank. The plane corresponding to the center line of the two pins 4 is the reference surface 5 ( Figure 3 b) The reference surface 5 is perpendicular to one of the radii of the gear blank. Then, the positional relationship between the starting key and starting tooth to be machined and the reference surface is determined to facilitate the machining of the keyway and teeth. In this embodiment, the position closest to the inner periphery of the gear blank center hole and the reference surface 5 is determined as the starting keyway 1. Figure 3As shown in c, the relative position of the starting key is determined based on the angle β between the midplane of the starting key 1 and the root center (or tooth top center) of the starting tooth 2.

[0024] Step 2, such as Figure 3 As shown in Figure c, when preparing to process the keyway on the wire cutting machine, in order to facilitate the reference surface 5 as a reference, the gear blank to be processed is accurately positioned on the workbench, a dial indicator is pre-fixed on the molybdenum wire rack of the wire cutting machine through a magnetic fixing seat, and then the gear blank is initially placed on the workbench of the cutting machine. First, the reference surface 5 corresponding to the center line of the two pins 4 is roughly perpendicular to the Y-axis direction of the workbench when visually inspected. Then the workbench is translated and the angle of the gear blank is slightly adjusted so that when the gear blank is translated along the X-axis with the workbench, the outer side readings of the generatrix of the two pins in the same position measured on the dial indicator are the same, so as to confirm that the reference surface 5 is perpendicular to the Y-axis. At this point, the position of the gear blank on the workbench has been determined. Depending on the size and weight of the gear, the gear blank is fixed to the workbench using a positioning fixture if necessary. The workbench is translated along the X or Y axis to drive the gear blank to move so that the center hole of the gear blank is aligned with the position where the molybdenum wire of the wire cutting machine passes through. After tightening the molybdenum wire, the gear is translated by the translation workbench. The position of the workbench is adjusted by the reciprocating translation of the molybdenum wire along the X and Y axes in the center hole so that the center axis of the gear blank coincides with the marking origin of the wire cutting machine. Then, the cutting pattern program of the double keyway is input, starting from the starting keyway, and each keyway is cut in sequence.

[0025] Step 3: Milling machine, such as Figure 3 As shown in Figure d, the gear blank after the second step of wire cutting is placed on the rotary table of the gear milling machine, and the center axis of the rotary table is adjusted to coincide with the center axis of the gear blank to locate the position of the gear blank, and then the reference surface 5 is adjusted to be parallel (or perpendicular) to the main shaft of the gear milling machine; the specific positioning adjustment method is: fix a dial indicator on the main shaft of the gear milling machine through a magnetic fixing seat, then translate the main shaft and adjust the angle of the dial indicator measuring head so that the measuring head of the dial indicator is radially aligned with the inner periphery of the center hole of the gear blank, and fine-tune the position of the gear blank while rotating the table. Rotate the worktable 360 ​​degrees. Measure the inner circumference of the center hole with a dial indicator, ensuring the reading remains constant, to confirm that the center of the center hole coincides with the worktable's rotational center. Then, rotate the worktable until the reference surface 5, corresponding to the centers of the two pins 4, is parallel to the milling machine's spindle. At this point, the reference surface is perpendicular to the Y-axis, the center axis of the gear blank coincides with the milling machine's coordinate origin, and the midplane of the starting keyway 1 coincides with the Y-axis. Rotate the worktable β degrees to position the starting tooth 2. Mill the gear starting from the starting tooth according to the milling procedure until the process is complete. This completes the positioning and machining of the keyway and gear of the large double-keyway gear.

[0026] The positioning processing method of the keyways and teeth of large gears with multiple keyways of the present invention is not limited to the above two embodiments. Any processing method that uses a specific tool to establish a reference surface tool with a specific positional relationship with the starting keyway and starting tooth on the gear surface, and determines the starting keyway and starting tooth by positioning the reference surface, is within the scope of protection of the present invention.

Claims

1. A positioning processing method for a large gear with double keyways at arbitrary angles, first preparing a gear blank to be processed, wherein the center of the gear blank is provided with a center hole, characterized in that: A reference surface fixture is made on the surface of the gear blank to establish a reference surface that forms a fixed positional relationship with the starting keyway and starting tooth to be processed. Then, based on the positional relationship between the reference surface and the starting key and starting tooth, the position of the gear blank and the position of the reference surface relative to the working coordinate axis of the processing equipment are positioned and adjusted on the processing table for positioning processing. The specific steps include: Step 1: A reference surface tool is made on the surface of the gear blank. Two centrally symmetrical pins are fixed on the surface of the gear blank. The plane where the centerline of the pins is located is used as the reference plane. The position of the starting keyway midplane is determined by the closest position between the inner circumference of the center hole and the reference plane. Then, the processing position of the starting tooth is determined according to the position requirements of the starting keyway and the starting tooth for subsequent processing. The starting keyway midplane is a plane perpendicular to the key bottom of the keyway to be processed. Step 2: Place the gear blank on the workbench of the wire cutting machine. Adjust the position of the gear blank relative to the workbench so that the reference surface is perpendicular or parallel to the Y-axis translation direction of the workbench to locate the position of the gear blank on the workbench. Then adjust the position of the workbench so that the center axis of the gear blank coincides with the coordinate origin of the wire cutting machine. Then, according to the input cutting pattern program, complete the cutting of each keyway in sequence starting from the starting keyway. Step 3: Place the gear blank after wire cutting in step 2 on the rotary table on the gear milling machine, adjust the center axis of the rotary table and the center axis of the gear blank to coincide to locate the position of the gear, and then adjust the reference surface and the main axis of the gear milling machine to be perpendicular; according to the position of the starting tooth determined in step 1, start milling the outer teeth of the gear in sequence.

2. The positioning processing method for large gears with double keyways at arbitrary angles according to claim 1, characterized in that: In step 1, when making the reference surface tooling, two centrally symmetrical fixing blocks are fixed on the surface of the gear blank. Positioning holes are respectively provided on the fixing blocks. The positioning holes on the two fixing blocks are centrally symmetrical with respect to the center hole of the gear blank. The pins are inserted into the positioning holes with interference fit and ensure that the two pins are centrally symmetrical along the gear blank.

3. The positioning processing method for large gears with double keyways at arbitrary angles according to claim 1, characterized in that: In step 1, the pins are located in the same diameter direction of the gear blank, and the midplane of the starting keyway coincides with the reference surface.

4. The positioning processing method for large gears with double keyways at arbitrary angles according to claim 3, characterized in that: In the second step, when adjusting the position of the gear blank on the workbench of the wire cutting machine, fix a dial indicator on the molybdenum wire rack of the wire cutting machine through a magnetic holder in advance, and then initially place the gear blank on the workbench so that the reference surface corresponding to the center line of the two pins is parallel to the Y-axis direction of the workbench. Shift the workbench and slightly adjust the angle of the gear blank so that when the gear blank is translated along the Y-axis, the outer sides of the two pins in the same direction measured on the dial indicator show the same reading to confirm that the reference surface is parallel to the Y-axis.

5. The positioning processing method for large gears with double keyways at arbitrary angles according to claim 3, characterized in that: In step 3, when adjusting the position of the gear blank on the rotary table, fix a dial indicator on the spindle of the gear milling machine through a magnetic mount so that the measuring head of the dial indicator is radially aligned with the inner circumference of the center hole of the gear blank. While rotating the rotary table, fine-tune the position of the gear blank so that the reading of the dial indicator measuring the inner circumference of the center hole remains unchanged after the rotary table rotates 360 degrees to confirm that the center of the center hole coincides with the rotation center of the rotary table. Then rotate the angle of the rotary table so that the reference surface corresponding to the center of the two pins is perpendicular to the spindle of the gear milling machine. Then, start milling the gear according to the angular difference between the starting tooth and the reference surface determined in step 1.

6. The positioning processing method for large gears with double keyways at arbitrary angles according to claim 1, characterized in that: In step 1, the pin is located in the non-diameter direction of the gear blank, and the mid-plane of the starting keyway is perpendicular to the reference plane.

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