JPS6031079Y2 - Gear heat treatment jig - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a jig for heat treatment of gears in which a plurality of gears are supported by spacers extrapolated to support columns and hardened.

Regarding surface hardening treatment of objects to be treated such as gears, there is a method of carburizing the object to be treated at a predetermined temperature and quenching it by immersing it in an oil bath or water bath, but in this case, the quenching is rough and distortion is likely to occur. For this reason, carburizing and quenching using a salt bath has recently been adopted.

This salt bath carburizing and quenching process is characterized by accurate and easy treatment temperature control, and clean quenching without oxidation of the surface of the workpiece.

Therefore, when precision-machined workpieces such as gears used in automobile transmissions and differentials are carburized and quenched in a salt bath, a salt solution is applied to the bath surface of a large number of vertically stacked gears. In addition to stirring and rectifying circulation, the salt temperature is controlled within a strict temperature range (for example, 2506°C ± 3°C), but the gears and the jig that supports the gears tend to shift relative to each other, and the jig is Because it directly supports the teeth of the gear, there are dents in the contact area, and the hardened structure of the teeth becomes non-uniform during hardening, resulting in abnormal changes in the tooth profile leads.

The present invention has been made in view of these drawbacks, and includes a spacer in which a step part for positioning the gear and a receiving part for supporting the inner part of the tooth part are provided in the shape of an equiangular fork.
By alternately stacking the spacer and gear on the support,
It is an object of the present invention to provide a jig for heat treatment of gears, which prevents spacers from interfering with tooth portions and enables uniform hardening of a large number of gears.

Hereinafter, the configuration of the present invention will be described in detail with reference to embodiments.

As shown in FIGS. 1 to 5, reference numeral 1 denotes a jig for heat treating a gear 2 such as a ring gear.

The jig is constructed so that a spacer 3 on which the gear 2 is placed is extrapolated onto a support 4 to support the gear 2.

The strut 4 has a protruding shaft part 5 at its lowermost end and a conical surface part 6 connected to the upper end of the protruding shaft part, and on the extension line of the axes of both 5 and 6, there are 1200 squares, respectively, centered on the extension line. Fins that extend at an angle? , 7.7 is formed into a bar member having a trident shape.

The spacer 3 has support arms 8, 8.8 at equal angles (120°
) is formed in a trifurcated shape, and the radial tip portion of each support arm is formed with a receiving portion 12.12.12 for supporting the inner portion 11 approaching the tooth bottom 10 of the tooth portion 9 of the gear 2. ,
Further, in the radial midway portion of each support arm 8, 8.8, a stepped portion 15, 15.
15 is formed, and each fin of the support column 4 is formed inside the stepped portion. , 7.7 are inserted into the engaging portions 16, 16, 16 having a narrow groove shape in cross section.

The receiving portions 12, 12, 12 and the step portions 15.15, 15
are formed on both the upper and lower sides of the spacer 3 (see FIG. 5), so either side can be used.

17.17... is each fin of the pillar 4 in order to improve the distribution of salt during immersion in a salt bath? ,7.
7 are long holes drilled in large numbers.

Reference numeral 18 denotes a tray having a frame structure, and the tray has round holes 19, 19, 19, 19, 19, 19, 19, 20, 30, 40, 40, 40, 40, 40, 40, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 4, 5, 5, 5, 5, 5, 5, 19, 19, 19, . . . .
It is equipped with...

In the above structure, each round hole 19, 19,
erect pillars 4, 4, etc., and stack spacers 3 and gears 2 alternately on each branch,
Laminate 20 for heat treating gears 2, 2...
．． After forming the trays 20, the trays 18 are held by lifting means (not shown) such as a hoist, and loaded into and taken out from heat treatment equipment such as a salt bath.

Each laminate 20.20 immersed in salt solution.
. . . The gears 2, 2 have a sufficient distance in the vertical direction by the jig 1, and the receiving portions 12, 12, 1 of the spacer 3
2, the inner part 11 close to the tooth bottom 10 is supported, and the central hole 13, 13, . . . of the gears 2, 2, .
... are positioned by the steps 15, 15.15 of the spacer, and each fin of the support column 4? , 7.7 long hole 1
7,1? Because the holes are provided, the salt solution flows in a good condition around the outer and inner circumferences of the gear 2, and the surface of the toothed portion 9 is uniformly carburized and hardened.

As a trial, we set up five columns 4 on a tray 18, and assembled a stacked product 2 with six transmission gears on each column 4, 4...
0, 20... and then carburized and quenched in a salt bath, good results were obtained in which the flatness was 30μ or less and the tooth profile lead variation was within ±3μ.

Note that in the jig 1, instead of this example, the fins 7 of the struts and the support arms 8 of the spacers may each be formed in the shape of more than three equiangular prongs.

The present invention has the above-mentioned configuration, and the supporting arm is extrapolated to the support arm of the bar member formed in the shape of three prongs or more than three prongs at equal angles, and a spacer formed in the shape of three prongs or more than three prongs is extrapolated. None, because the inner circumference of the gear is positioned by the stepped part of the support arm, and the inner part of the tooth part is supported by the receiving part of the support arm, carburizing and quenching are performed uniformly, and the defect rate is significantly lowered, resulting in a structural It has the excellent effect of being simple and greatly improving workability and durability.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the device of the present invention, and FIG. 1 is an external perspective view of a gear placed on a tray using the jig of the present invention;
Figure 2 is a perspective view of the support column, Figure 3 is a perspective view of the spacer, Figure 4 is a plan view with some parts omitted of the laminate made by stacking jigs and gears, and Figure 5 is a partial view. FIG. 1... heat treatment jig, 2... gear, 3
...Spacer, 4...Strut, 7...
...Fin, butt...Support arm, 9...
・Tooth portion, 12...Receiving portion, 15...Step portion.

Claims (1)

[Scope of utility model registration request] It is a jig that supports the gear by extrapolating a spacer on which the gear is placed onto a support.The support is a bar member having fins in the shape of three prongs at equal angles or in the shape of more than three prongs, and the spacer has support arms with equal angles. The branch arm is formed in a trifurcated or trifurcated shape, and a receiving part for supporting the inner part of the tooth of the gear is formed at the radial tip part of each branch arm, and the radial middle part of each support arm A jig for heat treatment of gears, in which a stepped part is formed that is loosely fitted into a hole in the center of the gear to position the gear, and the gear is supported by a part other than the tooth part.