JPS6228339Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a carbide throw-away hob for cutting the bottom of a tooth and chamfering the tip of a gear to be cut.

Conventional structure and its problems Conventionally, a knobbed hob or the like has been used to cut the bottom of the tooth, but when grinding the side surface of the gear, the tip of the grindstone hits the bottom and causes scratches.

In addition, implanted-blade type hobs have been seen, but there are problems with the precision of fixing the tips and the trouble of replacing them, and in particular, the implanted-blade type has never been used for tooth bottom grinding after hardening.
Normally, hardened gears are finished by finishing only the tooth surface by skiving hobbing with a negative angle on the tooth profile grinding cutting edge, but due to the distortion that occurs during hardening, the shape of the tooth bottom There are phenomena such as deformation, creating a step between the tooth surface and the tooth bottom, and interference between the outer periphery of the grinding wheel and the tooth bottom, and the amount of deformation caused by hardening is also a major problem, especially for medium and large modular gears. ing.

Purpose of the invention The present invention eliminates the drawbacks of the conventional examples, enables gear bottom cutting after hardening of gears with medium or larger modules, chamfers the tooth tips of gears to be machined, and provides super The purpose is to provide a hob that allows the hard tip to be replaced.

Structure and operation of the invention The present invention provides a hob in which a plurality of carbide chips are arranged along the threaded teeth on the cylindrical outer periphery of an alloy steel body. A groove, a plurality of locator seat processing parts provided in a direction across these grooves, a locator installed in this seat processing part, and a bottom surface machined with high precision on the front side in the hob rotation direction at the upper end of this locator. a conical carbide chip fixed to the chip seating surface processed portion with screws, a wedge driven between the locator and the groove, and a side surface of the hob. The hob is made up of a ring provided to press the side of the locator, and a tip chamfering tip provided at the chevron-shaped bottom of the body.

Therefore, the conical carbide chip is stably fixed by the chip seat processing section of the locator, and the locator is set in the groove of the body with high precision by the locator seat processing section. Also, since the tooth tip chamfering chip is attached to the front surface of the base of the locator, the tooth tip can be chamfered.

When replacing the carbide tip, the locator can be replaced together with the locator, and the locator and the groove can come into close contact with each other with high accuracy, making it possible to easily assemble the carbide tip and maintain accuracy.

DESCRIPTION OF EMBODIMENTS Hereinafter, drawings shown as embodiments will be described. 1
2 is a body made of alloy steel; 2 is a groove formed along the threaded tooth line Y-Y on the cylindrical outer periphery of the body;
Reference numeral 3 denotes a locator, which is installed with high precision in the locator seat processing section 4 provided in the groove. 5
is a carbide chip having a conical shape, and is set with high accuracy at the upper end of the locator to the chip seating surface processing section 6 provided on the front side in the direction of rotation of the hob. Reference numeral 7 denotes a wedge, which is designed to be driven between the locator 3 and the groove 2. 8 is a screw for tightening the wedge 7 to the body, 9 is a ring attached to the body 1 so as to fix both sides of the locator 3, and 10 is a fixing screw. Reference numeral 11 denotes a tip for chamfering the tooth tip of the gear to be cut, which is attached to the chevron-shaped bottom of the body.

As described above, in the present invention, the locator 3 can be accurately installed in the locator seat processing part 4 of the groove 2 formed in the body 1, and the locator 3 can be installed with high precision through the chip seat processing part 6 on the locator 3. Carbide tip 5
can be set. In this way, both the seat surface processing parts 4 and 6 make it possible to easily and accurately fix the carbide chip and the locator to the groove part. Since the carbide tip 5 has a conical shape, it can sufficiently release the cutting tip and has the effect of reducing cutting resistance. If necessary, the tip can be replaced via a locator, and a tip for chamfering the tooth tip can be installed separately.

The plurality of locators provided in the direction across the groove can be configured by shifting the position of the seat surface processing part 6 of the chip by the pitch P between the blades of the hob (the third
(see figure), the entire length and thickness of the locator in the width direction can be machined with high precision, and the back surface of the locator and the front surface of the hob groove can be maintained with high precision by grinding, etc., achieving high precision in terms of construction. In addition, it is fixed from both sides by rings 9, so there is almost no pitch error, the centripetality is extremely high, and there is no runout on the outer periphery, making it extremely convenient for maintaining accuracy as a hob.

Effects of the invention As described above, the present invention can provide a hob for cutting the tooth bottom of gears of medium or larger modules, and it has become possible to efficiently shape the gears by generating cutting after quenching to eliminate distortions etc. that occur during quenching. . The carbide tip has a conical shape, which reduces cutting resistance and allows it to be set in the groove of the body with extremely high precision using a locator. moreover,
It has great practical effects, such as the ability to easily replace the carbide tip along with the locator according to the shape of the tooth bottom, and also to be able to chamfer the tooth tip of the gear being cut.

[Brief explanation of the drawing]

Fig. 1 is a front view of the main part of the hob of the present invention, partially in cross section. Fig. 2 is a longitudinal cross section of the main part of the hob, and Fig. 3 is an exploded view of the carbide tip in the tooth direction. 1: Body, 2: Groove, 3: Locator, 4: Locator seating surface processing part, 5: Tip, 6: Tip seating surface processing part, 7: Wedge,
9...Ring, 11...Tip for chamfering tooth tip.

Claims (1)

[Scope of utility model registration request] In a hob in which a plurality of carbide chips are arranged along threaded teeth on the cylindrical outer periphery of an alloy steel body,
A plurality of grooves provided along the threaded teeth, a plurality of locator seat processing sections provided in a direction across these grooves, a locator installed in the seat processing section, and an upper end of the locator. A chip seat machined part whose bottom surface is machined with high precision on the front side in the hob rotation direction, a conical carbide chip fixed to this chip seat machined part with screws, etc., and the locator and the groove part. 1. A hob comprising: a wedge driven in between; a ring provided so as to press the side of the locator with the side surface of the hob; and a tip for chamfering the tooth tip provided on the chevron-shaped bottom of the body.