A method for machining spiral bevel gears on CNC milling equipment

Abstract

The present invention discloses a method for processing spiral bevel gears on CNC milling equipment, which relates to the field of mechanical processing technology. The design is based on the Gleason system hyperbolic spiral bevel gear motion development principle, and adopts the spiral bevel gear tooth blank and cutter disc linkage to realize the meshing of the tool and the tooth surface and to cut the teeth into the tooth surface, and the various motion relationships are controlled by the CNC program to move according to the meshing trajectory. The platform required for the processing is a four-axis linkage CNC machining center, CNC milling machine and other CNC milling equipment. At the same time, a linkage servo dividing head is placed on the workbench of the CNC milling equipment, which mainly completes the meshing movement between the tooth blank and the cutter disc and completes the single tooth milling forming. When the single tooth milling is completed, exit the workstation and perform tooth division, then enter the single tooth milling station, and perform the previous tooth milling process until the tooth profiles of all numbers of teeth on the spiral bevel gear are milled. Through verification, this design can basically meet the actual use requirements and design goals.

Description

Technical Field

[0001] The present invention relates to the field of mechanical processing, and more particularly to the technical field of a method for processing a spiral bevel gear on a numerically controlled milling device. Background Art

[0002] In gear manufacturing, spiral bevel gears are divided into the Gleason system in the United States, the Oerlikon system in Switzerland, and the Klingenberg system in Germany. Special equipment is used to manufacture the three types of gears.

[0003] Spiral bevel gears are needed in many fields such as vehicle transmission, reduction mechanism, shipbuilding and mining machinery in China, and the demand is huge. However, the production equipment of Gleason's standard hyperbolic spiral bevel gears costs nearly 50 to 70 million US dollars. Figure 1 As shown, it is also required to be equipped with Figure 2 Special tool shown.

[0004] Therefore, few companies purchase this type of equipment, which limits the promotion and application of this technology. Summary of the Invention

[0005] The purpose of the present invention is to solve the above technical problems and provide a method for machining spiral bevel gears on a CNC milling device.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0007] A method for machining a spiral bevel gear on a CNC milling device is provided. The machining method is performed by the CNC milling device on a four-axis CNC machining center. The machining method comprises the following steps:

[0008] Step 1: Rotational motion of the cutterhead

[0009] Install the cutter head on the spindle of the CNC milling equipment, and the spindle drives the cutter head to rotate;

[0010] Step 2: The cutter head moves in an elliptical arc relative to the gear blank

[0011] The elliptical arc motion of the cutter head relative to the gear blank is actually the elliptical arc trajectory formed by projecting the pitch circle of the driving wheel onto the work surface;

[0012] Step 3: Rotational motion of the gear blank

[0013] The rotational motion of the gear blank is achieved through the linkage of the CNC indexing head mounted on the workbench of the CNC milling equipment, i.e. the A-axis, so that the A-axis, X-axis and Y-axis of the gear blank are linked together and form a conjugate curved involute tooth profile with the cutter head cutting into the Z-axis;

[0014] Step 4: Tooth separation movement of the gear blank

[0015] The tooth division movement of the gear blank is also carried out by the CNC dividing head. After cutting a single tooth, the CNC dividing head withdraws from the gear cutting station and indexes to prepare for the next gear cutting position. This is achieved through the linkage of the A-axis, X-axis, and Y-axis.

[0016] Step 5: Advance the knife movement after cutting teeth

[0017] After cutting the gear, the tool moves forward. During the gear cutting process, the center of the cutter head deviates from the center of the tooth blank circle. β is the helix angle of the spiral bevel gear. The X value of the deviation is Dcosβ / 2, and the Y value of the deviation is (d-Dsinβ) / 2. Among them, d is the diameter of the tooth blank cutting circle, and D is the diameter of the cutter head.

[0018] Complete the meshing movement between the tooth groove of the tooth blank and the "tooth" of the cutter disc to complete the single tooth milling;

[0019] Step 6: Repeat the Single Tooth Milling Motion

[0020] When the single tooth milling is completed, exit the workstation and perform tooth division, then enter the single tooth milling station and perform the previous tooth milling process until the tooth profiles of all teeth on the spiral bevel gear are milled.

[0021] As an optional technical solution, step 2 specifically includes: the major axis L of the ellipse, the minor axis of the ellipse is Lcosα°, and the trajectory of the ellipse is achieved through the linkage of the X and Y axes of the CNC milling equipment.

[0022] As an optional technical solution, the entire single tooth milling process is to realize the tooth cutting "meshing" process of the milling single tooth and the tooth blank by linking the Z axis, X axis, Y axis and A axis at a ratio rate.

[0023] As an optional technical solution, step 5 specifically includes: taking the center of the tooth blank circle as the reference (0, 0), after milling one tooth, the center of the cutter head deviates from the point [Dcosβ / 2, (d-Dsinβ) / 2], the tooth blank is indexed, and after indexing, the center of the cutter head enters the point [Dcosβ / 2, (d-Dsinβ) / 2] to perform tooth cutting by generating motion;

[0024] Where d is the cutting circle diameter of the gear blank, and D is the cutter disc diameter.

[0025] As an optional technical solution, this method controls the movement of each motion relationship according to the meshing trajectory through the numerical control program

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. The entire process of the present invention is to place a linkage servo indexing head (A-axis) on the workbench of the CNC milling equipment and link it with the equipment (X-axis, Y-axis, Z-axis, and B-axis spindle rotation) to complete the meshing movement of the "tooth groove" of the gear blank and the "tooth" of the cutter disc to complete the single tooth milling forming.

[0028] 2. In the present invention, after the single-tooth milling is completed, the workstation is exited and the teeth are divided, and then the single-tooth milling station is entered to carry out the previous tooth milling process until the tooth profiles of all teeth on the spiral bevel gear are milled. This design can basically meet the actual use requirements and design goals. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of a special spiral bevel gear grinding machine made by Gleason in the background art;

[0030] Figure 2 Is a schematic diagram of the background technology Gleason system dedicated spiral bevel gear milling cutter;

[0031] Figure 3 It is a schematic diagram of meshing spiral bevel gears in pairs;

[0032] Figure 4 This is a schematic diagram of a milling cutter head cutting teeth;

[0033] Figure 5 It is a schematic diagram of the tooth shape of a tooth groove formed by the milling cutter head cutting the teeth;

[0034] Figure 6 It is a three-dimensional schematic diagram of the linkage of each axis of CNC milling equipment;

[0035] Figure 7 This is a schematic diagram of the various motions of CNC milling equipment for milling teeth;

[0036] Figure 8 It is a three-dimensional schematic diagram of the CNC dividing head;

[0037] Figure 9 This is a schematic diagram of a CNC dividing head. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0040] Example 1

[0041] like Figures 1 to 9 As shown, this embodiment provides a method for processing spiral bevel gears on a CNC milling device. The processing method is completed by the CNC milling device on a four-axis CNC machining center. The processing method includes the following steps:

[0042] Step 1: Rotational motion of the cutterhead

[0043] Install the cutter head on the spindle of the CNC milling equipment, and the spindle drives the cutter head to rotate;

[0044] Step 2: The cutter head moves in an elliptical arc relative to the gear blank

[0045] The elliptical arc motion of the cutter head relative to the gear blank is actually the elliptical arc trajectory formed by projecting the pitch circle of the driving wheel onto the work surface;

[0046] Step 3: Rotational motion of the gear blank

[0047] Step 4: Tooth separation movement of the gear blank

[0048] Step 5: Advance the knife movement after cutting teeth

[0049] After cutting the gear, the tool moves forward. During the gear cutting process, the center of the cutter head deviates from the center of the tooth blank circle. β is the helix angle of the spiral bevel gear. The X value of the deviation is Dcosβ / 2, and the Y value of the deviation is (d-Dsinβ) / 2. Among them, d is the diameter of the tooth blank cutting circle, and D is the diameter of the cutter head.

[0050] Taking the center of the tooth blank circle as the reference (0, 0), after milling one tooth, the cutter head center deviates from the point [Dcosβ / 2, (d-Dsinβ) / 2], and the tooth blank is indexed. After indexing, the cutter head center enters the point [Dcosβ / 2, (d-Dsinβ) / 2] to perform tooth generation; where d represents the diameter of the tooth blank cutting circle, and D represents the cutter head diameter.

[0051] Complete the meshing movement between the tooth groove of the tooth blank and the "tooth" of the cutter disc to complete the single tooth milling;

[0052] Step 6: Repeat the Single Tooth Milling Motion

[0053] When the single tooth milling is completed, exit the workstation and perform tooth division, then enter the single tooth milling station and perform the previous tooth milling process until the tooth profiles of all teeth on the spiral bevel gear are milled.

[0054] Specific working principle: The invention is designed based on the principle of meshing motion development of Gleason quasi-hyperbolic spiral bevel gears. The spiral bevel gear blank is linked with the milling cutter to realize the meshing of the tool and the tooth surface and to cut the tooth surface gradually. The CNC program controls the movement relationship according to the meshing trajectory. The milling cutter is equivalent to a pair of meshing spiral bevel gears ( Figure 3) of a tooth (driving wheel), the axis of the cutter head and the axis of the tooth blank are at different positions according to the different helix angles ( Figure 4 ), when the cutter disc rotates and cuts into the gear blank (driven wheel), one tooth of the cutter disc simulates the meshing motion trajectory with the gear blank to form a tooth shape of a tooth groove.

[0055] Example 2

[0056] Based on Example 1, the elliptical arc motion of the cutter head relative to the gear blank is actually the elliptical arc trajectory formed by projecting the pitch circle of the driving wheel onto the work surface ( Figure 5 ), the major axis of the ellipse is L, the minor axis of the ellipse is Lcosα°, and the trajectory of the ellipse is achieved by the linkage of the X and Y axes of the CNC milling equipment ( Figure 6 ), the entire milling process of a single tooth is that the Z axis, X axis, Y axis, and A axis are linked at a ratio rate to achieve the "meshing" process of the milled single tooth and the tooth blank.

[0057] Example 3

[0058] Based on Example 1, the rotation of the gear blank is achieved by a CNC indexing head ( Figure 8 ) that is, the linkage of the A axis, so that the gear blank (the linkage of the A axis, X axis, and Y axis) and the cutter head (Z axis) form a conjugate curved involute tooth shape. The tooth division movement of the gear blank is also controlled by the CNC dividing head ( Figure 8 ) After cutting a single tooth, the CNC dividing head withdraws from the gear cutting station and indexes to prepare for the next gear cutting position. This is mainly achieved through the linkage of the A-axis, X-axis, and Y-axis.

[0059] Example 4

[0060] Based on Example 1, the cutter moves forward after cutting the teeth. The center of the cutter head and the center of the tooth blank circle are deviated during the cutting process ( Figure 9 ), as shown in the figure, where β is the helix angle of the spiral bevel gear, the X value of the deviation is Dcosβ / 2, and the Y value of the deviation is (d-Dsinβ) / 2. With the center of the tooth blank as the reference (0, 0), after milling one tooth, the cutter head center deviates from the point [Dcosβ / 2, (d-Dsinβ) / 2], and the tooth blank is indexed. After indexing, the cutter head center enters the point [Dcosβ / 2, (d-Dsinβ) / 2] to perform the generating motion and tooth cutting.

[0061] Where d is the cutting circle diameter of the gear blank, and D is the cutter disc diameter.

[0062] In summary, the entire process of this method involves placing a servo indexing head (A-axis) on the worktable of the CNC milling machine, which is linked to the machine (X-axis, Y-axis, Z-axis, and B-axis spindle rotation) to achieve the meshing movement between the "tooth groove" of the gear blank and the "tooth" of the cutterhead, completing the single-tooth milling process. Once the single-tooth milling process is completed, the workstation exits and the gear is indexed, then re-enters the single-tooth milling station and repeats the previous milling process until the tooth profile of all teeth on the spiral bevel gear is milled.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for machining a spiral bevel gear on a CNC milling machine, characterized in that: The processing method is completed by CNC milling equipment on a four-axis CNC machining center, and the processing method includes the following steps: Step 1: Rotational motion of the cutterhead Install the cutter head on the spindle of the CNC milling equipment, and the spindle drives the cutter head to rotate; Step 2: The cutter head moves in an elliptical arc relative to the gear blank The elliptical arc motion of the cutter head relative to the gear blank is actually the elliptical arc trajectory formed by projecting the pitch circle of the driving wheel onto the work surface; Step 3: Rotational motion of the gear blank The rotational motion of the gear blank is achieved through the linkage of the CNC indexing head mounted on the workbench of the CNC milling equipment, i.e. the A-axis, so that the A-axis, X-axis and Y-axis of the gear blank are linked together and form a conjugate curved involute tooth profile with the cutter head cutting into the Z-axis; Step 4: Tooth separation movement of the gear blank The tooth division movement of the gear blank is also carried out by the CNC dividing head. After cutting a single tooth, the CNC dividing head withdraws from the gear cutting station and indexes to prepare for the next gear cutting position. This is achieved through the linkage of the A-axis, X-axis, and Y-axis. Step 5: Advance the knife movement after cutting teeth After cutting the gear, the cutter moves forward. During gear cutting, the center of the cutter disc deviates from the center of the tooth blank circle. β is the helix angle of the spiral bevel gear. The X value of the deviation is Dcosβ / 2, and the Y value of the deviation is (d-Dsinβ) / 2. Among them, d is the diameter of the tooth blank cutting circle, and D is the cutter disc diameter. Complete the meshing movement between the tooth groove of the tooth blank and the "tooth" of the cutter disc to complete the single tooth milling; Step 6: Repeat the Single Tooth Milling Motion When the single tooth milling is completed, exit the workstation and perform tooth division, then enter the single tooth milling station and perform the previous tooth milling process until the tooth profiles of all teeth on the spiral bevel gear are milled.

2. The method for machining a spiral bevel gear on a CNC milling machine according to claim 1, characterized in that: The step 2 specifically includes: the major axis L of the ellipse, the minor axis of the ellipse is Lcosα°, and the trajectory of the ellipse is achieved through the linkage of the X and Y axes of the CNC milling equipment.

3. The method for machining a spiral bevel gear on a CNC milling machine according to claim 2, characterized in that: The entire single tooth milling process is a process in which the Z axis, X axis, Y axis, and A axis are linked at a ratio rate to achieve the "meshing" process of the milled single tooth and the tooth blank.

4. The method for machining a spiral bevel gear on a CNC milling machine according to claim 1, characterized in that: The step 5 specifically includes: taking the center of the tooth blank circle as the reference (0, 0), after milling one tooth, the center of the cutter head deviates from the point [Dcosβ / 2, (d-Dsinβ) / 2], the tooth blank is indexed, and after indexing, the center of the cutter head enters the point [Dcosβ / 2, (d-Dsinβ) / 2] to perform tooth generating motion cutting; Where d is the cutting circle diameter of the gear blank, and D is the cutter disc diameter.

5. A method for machining a spiral bevel gear on a CNC milling machine according to any one of claims 1 to 4, characterized in that: This method controls each motion relationship to move along the meshing trajectory through a numerical control program.

Images