RU74327U1 - MILLING BLOCK FOR REMOVAL OF CHAINS AT THE END OF TOOTH TOOTHS - Google Patents

Abstract

The milling unit for chamfering at the ends of the teeth of the gears contains a mandrel (1). A single-turn worm milling cutter (3) placed on a mandrel and secured with fastening parts (2). The cutter (3) contains teeth (4), made on one turn of the worm, the axial pitch of which differs from the circumferential pitch of the machined wheel. The teeth (4) have cutting edges (5) and (6) on one side and top of the tooth. An additional worm single-turn mill (7) is placed on the mandrel (1). Its teeth (8) contain cutting edges (9) and (10) on the opposite side and top, and the top of the tooth (10) is made at an angle ε to the axis of the cutter, which is chosen from the following inequality: Where b - value of the vertex cutter tooth offset from the center of the workpiece; β is the angle between the front surface of the cutter tooth and the end face of the workpiece at the moment of their contact; D _f - the diameter of the beginning of the chamfer. Teeth 4 and 8 of both cutters 3 and 7 have different profile angles and different axial steps. Problem to be solved: expanding the technological capabilities of the milling unit for machining chamfers on both sides and in the cavity of the teeth of the workpiece.

Description

The utility model relates to metalworking and can be used for chamfering at the ends of the teeth of spur and helical gears.

Known milling unit for chamfering at the ends of the teeth of the gears, selected as the closest analogue, containing a mandrel placed on it and fixed with fastening parts, a single-turn worm milling cutter containing teeth made on one turn of the worm, the axial pitch P _{0 of} which differs from circumferential pitch of the machined wheel and having cutting edges on one side and top of the tooth (Production of gears. Edited by B.A. Taits. 2nd ed., revised and enlarged M .: Mashinostroenie, 1975, p. 431 ; Drawing 06-6270-4057 of 17.10.2 007 OJSC KAMAZinstrumentspetsmash, PGO).

This milling unit is used for chamfering and deburring the sharp edges of the teeth of helical gears on one side. Processing is carried out with continuous and consistent rotation of the tool. The removal of the allowance is due to the difference in the steps of the tool and the workpiece.

The disadvantage of this milling unit is its narrow technological capabilities, which do not allow to process chamfers on both sides of the teeth and in the cavity.

This problem can be solved by performing cutting edges on both sides of the cutter teeth and their variable thickness. However, this design is low-tech, and complicates the manufacturing process of the cutter. Also, the processing of chamfers along the contour can be carried out with two mills in two operations. But this leads to a decrease in productivity or an increase in the machine stock of the enterprise.

The technical task to which the utility model is directed is to expand the technological capabilities of the milling unit by providing the possibility of machining bevels on both sides of the teeth and in the cavity in one operation on one machine.

This problem is solved in that the milling unit for chamfering at the ends of the teeth of the gear wheels, containing a mandrel placed on it and secured using fastening parts, a single-turn worm cutter containing teeth made on one turn of the worm, the axial pitch of which differs from the circumferential pitch of the machined the wheels and having cutting edges on one side and apex of the tooth contain an additional worm single-turn mill placed on the mandrel, its teeth contain cutting edges on the opposite sides th side and the top, wherein the tops of the teeth formed at an angle ε to the cutter axis, which is selected from the following inequality:

,

where b is the displacement of the tip of the cutter tooth from the center of the workpiece;

β is the angle between the front surface of the cutter tooth and the end face of the workpiece at the moment of their contact;

D _f - the diameter of the beginning of the chamfer,

while the teeth of both cutters have different profile angles and different axial steps.

The implementation of the milling unit with an additional worm single-turn milling cutter, the teeth of which have different profile angles and axial steps and contain cutting edges on the opposite side and top, in combination with the execution of the top of its teeth at an angle ε to the cutter axis, which is chosen from the above inequalities will allow for one revolution of the milling unit to process a uniform chamfer on both sides of the sides and in the cavity of the teeth of the workpiece in one operation without additional equipment.

The execution of the tooth top of the additional cutter without tilting will lead to an uneven chamfer along the depression, and the execution of the tilting angle equal to the calculated value will lead to the formation of a ledge at the junction of the bevels machined with different cutters. The choice of the angle ε greater than the calculated value will allow for a smooth transition of the chamfers machined with different mills one into another.

The applicant is not aware of milling blocks for chamfering with the specified set of essential features and the claimed combination of essential features does not follow explicitly from the current level of technology, which confirms the conformity of the claimed technical solution to the condition of "novelty".

The claimed technical solution is illustrated by drawings, where:

figure 1 - milling unit for chamfering (General view);

figure 2 - remote element A in figure 1;

figure 3 - view B in figure 2;

figure 4 is a design diagram.

The milling unit for chamfering at the ends of the teeth of the gear wheels contains a mandrel 1. A single-turn worm mill 3 placed on the mandrel and secured with fasteners 3. The mill 3 contains teeth 4 made on one turn of the worm, the axial pitch of which differs from the circumferential pitch of the machined wheel . Teeth 4 have cutting edges 5 and 6 on one side and top of the tooth. An additional worm single-turn milling cutter 7 is placed on the mandrel 1. Its teeth 8 contain cutting edges 9 and 10 on the opposite side and apex, and the top of the tooth 10 is made at an angle ε to the milling axis, which is chosen from the following inequality:

,

where b is the displacement of the tip of the cutter tooth from the center of the workpiece;

β is the angle between the front surface of the cutter tooth and the end face of the workpiece at the moment of their contact;

D _f - the diameter of the beginning of the chamfer.

Teeth 4 and 8 of both cutters 3 and 7 have different profile angles and different axial steps.

The determination of the angle of the tooth tip of an additional worm single-turn mill will be considered as an example.

Initial data:

b = 40 mm;

β = 55 °;

D _f = 276.5 mm.

The right side of the inequality will have the following meaning:

Thus, to avoid the formation of a step on the machined surface of the chamfer in the cavity, the angle of inclination of the top ε of the additional cutter must be selected more than 9.84 °.

The angle value ε = 10 ° satisfies this condition.

The process of chamfering at the ends of the cylindrical gears by the claimed milling unit is as follows. Processing is carried out with continuous rotation of the machined wheel and the milling unit. Moreover, in one revolution of the block, the wheel will turn by one angular step. The first teeth of both cutters do not remove the allowance, but pass into contact with the adjacent lateral sides of two different teeth of the wheel. The teeth of the cutters have different axial steps, so when the cutters rotate, the cutting edges of the teeth unevenly move along the axis of the cutters, which ensures that the stock is removed. In this case, the tops of the teeth of each cutter removes part of the allowance in the cavity. The angle of the tooth tip of the additional cutter allows you to ensure evenness of the chamfer in the cavity and to prevent the formation of ledges at the intersection of the machined sections of the teeth of different cutters. Finally, the chamfer is formed by the last teeth of the cutters.

The milling unit for chamfering at the ends of the gear teeth can be manufactured using standard equipment using well-known materials and modern tools, which meets the criterion of “industrial applicability”.

Claims (1)

A milling unit for chamfering at the ends of the teeth of the gear wheels, containing a mandrel placed on it and fastened using fastening parts, a single-turn worm milling cutter containing teeth made on one turn of the worm, the axial pitch of which differs from the circumferential pitch of the machined wheel, and having cutting edges on one side and top of the tooth, characterized in that it contains an additional single-turn worm milling cutter placed on the mandrel, its teeth contain cutting edges on the opposite side and the top, wherein the tooth tip is formed at an angle ε to the cutter axis, which is selected from the following inequality:

, where b is the displacement of the tip of the cutter tooth from the center of the workpiece; β is the angle between the front surface of the cutter tooth and the end face of the workpiece at the moment of their contact; D _f - the diameter of the beginning of the chamfer, while the teeth of both cutters have different profile angles and different axial steps.