JPH04210322A - Gear grinding wheel and gear machining method - Google Patents

Abstract

PURPOSE:To achieve the improvement of accuracy and higher efficiency machining by grinding the tips of abrasive grains by grinding or lapping of a part of the grinding surface obtained by sticking super abrasive grains on the whole surface of tooth profile part by electroplating. CONSTITUTION:On the grinding surface on which super abrasive grains are stuck by electroplating, an A part in a controlled ground portion and a B part is a general grinding surface on which super abrasive grains are stuck only by electroplating, or a surface which is ground for improving the shape accuracy. Only the tip part less than 20% of tooth profile from the tip part to the bottom is ground and machined, and instead of grinding, lapping can be performed. With the machined gear, tensile stress is exserted on near the fillet part of root of tooth. The gear is machined by using an intermeshing type grinding wheel, and thus object compression gears can be produced at extremely high efficiency.

Description

Detailed Description of the Invention (Industrial Field of Application) This invention is a measure against the monomerization of gears for automobiles, in order to enable the design J4 with a thin face width. , tensile stress is generated on the tooth surface due to M generation during machining, and there is a limit to how thin the tooth width can be made.

However, by grinding using the grinding wheel of the present invention, compression gears can be easily manufactured and can be designed to have a thinner face width than conventional processing methods.

(Prior Art) This type of grindstone has been used with superabrasive grains fixed by electroplating, or with the entire surface adjusted and ground to improve shape accuracy.

(Problems to be Solved by the Invention) A compression gear could not be formed by machining using a conventional super-abrasive electrodeposition interlocking gear grinding wheel. By specially adjusting one part of the abrasive surface, a suitable amount of heat is generated only in the surface light smelting portion, making it possible to design a thin tooth width. With the grindstone of the present invention, compression gears can be obtained at the same time with improved accuracy through grinding, and high-efficiency machining can be achieved.

(Example) In FIG. 3, reference numeral 1 denotes a cylindrical base metal having a mounting hole 2 in the center, and a superabrasive grain layer 3 is provided on the outer peripheral edge.

FIG. 2 is a partially enlarged view of the tooth-shaped superabrasive grain layer. The alloy in the example is made of steel, has a diameter of 240 mm, and has a mounting hole diameter of G.
3.5mm, width 50.8mm (Figure 3). On the abrasive surface to which superabrasive grains are fixed by electroplating, the specially adjusted and ground portion of the present invention is shown in FIG. 1, and section A indicates the position.

Part B is a general abrasive surface that is used to fix superabrasive grains only by electric plating, or is ground to improve shape accuracy, and is a different abrasive surface from the abrasive surface of the present invention. A special grinding process was performed only on the tip of the tooth profile, which is less than 20% of the tooth profile from the tip to the tooth bottom. It is also possible to perform lapping instead of grinding.

FIG. 4 shows the machined gear and shows that tensile stress is acting near the tooth base part 5.

Figure 5 shows a cross section of superabrasive grains fixed by electroplating.
indicates a specially ground part. In the example, 80 meters,
It was used within the range of 400 meters/knee/yu. In addition, in order to obtain the machining characteristics of the present invention, the effect due to the difference in the local grinding P1 ability of the grinding surface, and not the absolute value, is due to the f
This is an important point on l.

A gear was machined using the interlocking gear grinding wheel of the present invention. The conditions are as follows: Machining conditions Work rotation speed 3,000-3.80 Orpm Sliding speed 450- GOOm/mln Axis intersection angle
30゛ Cutting speed 0.4-0.8mm/mln Grinding wheel used Number of teeth 6I Helix angle 0 Viscosity #140 Target workpiece material 50M415 Gear specifications Module 2.5 Pressure angle 17.5゜ Number of teeth 35 Helix angle 30゜LH With a face width of I6, it is possible to produce the desired compression gear with extremely high efficiency, and in gear fatigue experiments, it is approximately 50
% improvement in strength was observed.

When manufacturing grinding wheels, based on many years of experience with superabrasive grains produced by electroplating, it is extremely easy to manufacture by partially designing the superabrasive grains into a double layer, and by meshing the ejected superabrasive grains with the master gear. As a result, a homogeneous abrasive surface of the present invention in which the amount of grinding was intentionally changed in one part was obtained. Of course, diamond grains, CBN grains, etc. are used as the superabrasive grains.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the tooth structure of a grindstone according to an embodiment of the present invention;
Fig. 2 is a schematic diagram showing the tooth shape of the grinding wheel, Fig. 3 is a cross-sectional view showing the basic structure of the grinding wheel, Fig. 4 is a schematic diagram illustrating the tooth base of the gear, and Fig. 5 is a schematic diagram of the grinding wheel. It is a schematic diagram explaining a surface. 1... Cylindrical base metal, 2... Mounting hole, 3... Super abrasive grain layer. ′! J4 diagram

Claims (3)

[Claims] (1) In an interlocking type gear grinding wheel with a superabrasive grain layer provided on the outer peripheral edge of a cylindrical shape, a part of the abrasive surface is ground where the superabrasive grains are fixed to the entire surface of the tooth profile by electroplating. Or a gear grinding wheel with the abrasive grain tips removed by lapping. (2) A gear grinding wheel in which the processing characteristics of an interlocking gear grinding wheel are adjusted by grinding or lapping the tips of abrasive grains fixed to a portion of the grinding surface of the grinding wheel by electroplating. (3) With the gear grinding wheel described in claim (1) or (2), residual stress due to heat generated by grinding is applied only to the dentinal part of the gear to be processed, thereby improving the stress balance of the tooth part. A gear processing method characterized by forcing the gear into a compressed state.