阅读说明：本技术 一种半轴齿轮内花键渗碳淬火方法及渗碳淬火设备 (carburizing and quenching method and carburizing and quenching equipment for internal spline of half axle gear ) 是由 洪新阳 黄刚敏 周学平 张信伟 郑敏敏 于 2019-10-18 设计创作，主要内容包括：本发明公开了一种半轴齿轮内花键渗碳淬火方法及渗碳淬火设备,其方法包括在半轴齿轮上套接补偿套,并放入内部低压的淬火炉内,接着将内花键加热至900℃,并在内花键位置处通入丙烷,持续240min；然后将内花键的温度降至840℃,并持续通入丙烷45min；停止加热和丙烷的通入,并改为通入高压高纯度氮气,持续20min,最后从淬火炉内取出半轴齿轮冷却至室温；其设备包括淬火炉,淬火炉内设置有中空的放置柱,淬火炉的底部连接有抽气管；放置柱侧面的切线方向上通过进气管连接有第一支管和第二支管；所述淬火炉的顶端连接有伸缩缸,伸缩缸的底端通过电机固定有电阻式加热线圈。本发明不仅能够提高内花键位置处的渗碳效果,还具有内花键变形较小的优点。(The invention discloses a carburizing and quenching method and a carburizing and quenching device for an internal spline of a half axle gear, wherein the method comprises the steps of sleeving a compensation sleeve on the half axle gear, putting the half axle gear into a quenching furnace with low internal pressure, heating the internal spline to 900 ℃, and introducing propane into the position of the internal spline for 240 min; then, reducing the temperature of the inner spline to 840 ℃, and continuously introducing propane for 45 min; stopping heating and introducing propane, introducing high-pressure high-purity nitrogen instead, continuing for 20min, and finally taking out the half-shaft gear from the quenching furnace and cooling to room temperature; the equipment comprises a quenching furnace, wherein a hollow placing column is arranged in the quenching furnace, and the bottom of the quenching furnace is connected with an exhaust pipe; a first branch pipe and a second branch pipe are connected in the tangential direction of the side surface of the placing column through an air inlet pipe; the top end of the quenching furnace is connected with a telescopic cylinder, and the bottom end of the telescopic cylinder is fixed with a resistance heating coil through a motor. The invention not only can improve the carburizing effect at the position of the internal spline, but also has the advantage of small deformation of the internal spline.)

1. A carburizing and quenching method for an internal spline of a half shaft gear is characterized by comprising the following steps:

a. Sleeving a compensation sleeve on a half shaft part on the half shaft gear to obtain a product A; at the moment, the thicknesses of the two ends of the half axle gear are the same;

b. Vertically placing the product A into the top end of a hollow placing column in a quenching furnace, and exhausting the quenching furnace until the pressure in the quenching furnace is 150-2000 pa;

c. Arranging a resistance-type heating coil at the position of an internal spline in the middle of the half axle gear, and then electrifying the resistance-type heating coil to heat the internal spline on the half axle gear to 880-950 ℃;

d. Then, introducing propane with the flow rate of 0.08-0.15 m3/h from bottom to top through a hollow placing column for 220-280 min to obtain a product D;

e. Then, reducing the temperature of the internal spline of the half axle gear in the product D to 820-840 ℃, and continuously introducing propane with the flow rate of 0.08-0.15 m3/h for 40-50 min to obtain a product E;

f. removing the resistance heating coil, stopping introducing propane, introducing nitrogen with the pressure of 1-1.5 Mpa to the position of the spline in the half axle gear in the E product from bottom to top through a hollow placing column, and continuing for 15-20 min to obtain a product F;

g. and taking the F product out of the quenching furnace, cooling to room temperature, and then taking down the compensation sleeve on the half axle gear to obtain a finished product.

2. the carburizing and quenching method for the internal spline of the side gear according to claim 1, characterized in that: the propane is spirally input from bottom to top along the placing column.

3. The carburizing and quenching method for the internal spline of the side gear according to claim 1, characterized in that: the nitrogen is spirally input from bottom to top along the placing column.

4. a carburizing and quenching apparatus for a carburizing and quenching method for an internal spline of a side gear according to any one of claims 1 to 3, characterized in that: comprises a quenching furnace (1), wherein a pressure gauge (16) and a thermometer (17) are arranged on the quenching furnace (1); a hollow placing column (2) is arranged in the quenching furnace (1), and the bottom of the quenching furnace (1) is connected with an air exhaust pipe (3); an air inlet pipe (4) is connected in the tangential direction of the side surface of the placing column (2), and a first branch pipe (5) and a second branch pipe (15) are connected on the air inlet pipe (4); a horizontal annular placing rack (6) is arranged at the top of the placing column (2), and a furnace door (7) is arranged on the side surface of the quenching furnace (1) corresponding to the placing rack (6); the top end of the quenching furnace (1) is connected with a vertically arranged telescopic cylinder (8), the bottom end of the telescopic cylinder (8) is fixed with a motor (9), and the bottom end of the motor (9) is fixed with a resistance heating coil (10).

5. the carburizing and quenching apparatus according to claim 4, characterized in that: the air extraction pipe (3) is connected with an air extraction pump (11), and the air extraction pipe (3) is provided with a check valve (12).

6. The carburizing and quenching apparatus according to claim 4, characterized in that: the first branch pipe (5) and the second branch pipe (15) are both connected with a switch valve (13).

7. The carburizing and quenching apparatus according to claim 4, characterized in that: and a sealing strip (14) is arranged on the furnace door (7).

Technical Field

The invention relates to a carburizing and quenching method and quenching equipment for an internal spline of a gear, in particular to a carburizing and quenching method and quenching equipment for an internal spline of a half axle gear.

background

At present, the gear quenching commonly seen in the market is to put the gear into a quenching furnace with high internal temperature, and introduce methane, propane and other gases into the quenching furnace to carburize the surface of the gear, and then directly immerse the carburized gear into quenching oil to cool and quench, so that the surface of the gear has better wear resistance and hardness, and the inside of the gear still keeps toughness; but the half axle gear with the internal spline is quenched by adopting the device, and methane and other gases are directly filled into the quenching furnace, so that the gases are not easy to reach the position of the internal spline, and the carburizing effect at the position of the internal spline is poor; the temperature of one end part of the heating position in the quenching furnace is high, the internal temperature distribution is uneven, so that the integral heating effect of the internal spline is uneven, and the internal spline can deform greatly after quenching; meanwhile, the thicknesses of the two end parts of the side gear are not uniform, the deformation degrees of the two end parts of the internal spline are different during quenching, and the internal spline is easy to be greatly distorted. Therefore, the existing half shaft gear carburizing and quenching method and equipment have the problems of poor carburizing effect at the position of the internal spline and large deformation of the internal spline.

disclosure of Invention

the invention aims to provide a carburizing and quenching method and carburizing and quenching equipment for an internal spline of a half shaft gear. The invention not only can improve the carburizing effect at the position of the internal spline, but also has the advantage of small deformation of the internal spline.

the technical scheme of the invention is as follows: a carburizing and quenching method for an internal spline of a half axle gear comprises the following steps:

a. Sleeving a compensation sleeve on a half shaft part on the half shaft gear to obtain a product A; at the moment, the thicknesses of the two ends of the half axle gear are the same;

b. vertically placing the product A into the top end of a hollow placing column in a quenching furnace, and exhausting the quenching furnace until the pressure in the quenching furnace is 150-2000 pa;

c. Arranging a resistance-type heating coil at the position of an internal spline in the middle of the half axle gear, and then electrifying the resistance-type heating coil to heat the internal spline on the half axle gear to 880-950 ℃;

d. Then, introducing propane with the flow rate of 0.08-0.15 m3/h from bottom to top through a hollow placing column for 220-280 min to obtain a product D;

e. Then, reducing the temperature of the internal spline of the half axle gear in the product D to 820-840 ℃, and continuously introducing propane with the flow rate of 0.08-0.15 m3/h for 40-50 min to obtain a product E;

f. removing the resistance heating coil, stopping introducing propane, introducing nitrogen with the pressure of 1-1.5 Mpa to the position of the spline in the half axle gear in the E product from bottom to top through a hollow placing column, and continuing for 15-20 min to obtain a product F;

g. and taking the F product out of the quenching furnace, cooling to room temperature, and then taking down the compensation sleeve on the half axle gear to obtain a finished product.

in the carburizing and quenching method for the internal spline of the side gear, the propane is spirally input from bottom to top along the placing column.

In the carburizing and quenching method for the internal spline of the side gear, the nitrogen is spirally input from bottom to top along the placing column.

The carburizing and quenching equipment for the carburizing and quenching method of the internal spline of the half shaft gear comprises a quenching furnace, wherein a pressure gauge and a temperature gauge are arranged on the quenching furnace; a hollow placing column is arranged in the quenching furnace, and the bottom of the quenching furnace is connected with an exhaust pipe; an air inlet pipe is connected in the tangential direction of the side surface of the placing column, and a first branch pipe and a second branch pipe are connected to the air inlet pipe; a horizontal annular placing rack is arranged at the top of the placing column, and a furnace door is arranged on the side surface of the quenching furnace corresponding to the placing rack; the top end of the quenching furnace is connected with a vertically arranged telescopic cylinder, the bottom end of the telescopic cylinder is fixedly provided with a motor, and the bottom end of the motor is fixedly provided with a resistance-type heating coil.

In the carburizing and quenching equipment, the exhaust pipe is connected with an exhaust pump, and is provided with a check valve.

in the carburizing and quenching equipment, the first branch pipe and the second branch pipe are both connected with switch valves.

In the carburizing and quenching equipment, the furnace door is provided with a sealing strip.

Compared with the prior art, the carburization quenching method for the internal spline of the half shaft gear is improved, the half shaft part on the half shaft gear is sleeved with the compensation sleeve, so that the thicknesses of two ends of the twelve-point half shaft gear are the same, the deformation degrees of the two ends of the half shaft gear are consistent as much as possible during later quenching, and the two ends of the internal spline are prevented from being twisted; pumping the quenching furnace to a low-pressure vacuum state for carburizing, wherein propane serving as carburizing gas uniformly passes through the position of the internal spline from bottom to top along the placing column, and the internal spline is uniformly heated by a resistance-type heating coil (the height is more than or equal to the length of the internal spline), so that the carburizing uniformity is higher; carburizing, wherein the carburizing effect at the position of the internal spline is good through a strong carburizing and diffusion period at 880-950 ℃ and a heat preservation period at 820-840 ℃; and finally, introducing high-pressure high-purity nitrogen from bottom to top along the placing column, so that the nitrogen continuously and quickly quenches the inner spline through the position of the inner spline, and the inner spline is more uniformly deformed after quenching and cooling. In addition, the propane and the nitrogen in the invention are input from bottom to top in a building-type selective manner, and further the propane and the nitrogen can uniformly pass through the positions of the internal spline, so that the carburizing and quenching of the internal spline are uniform, and the deformation is small; the invention improves the prior carburizing and quenching equipment, a hollow placing column is arranged in a quenching furnace, an annular placing rack is arranged at the top end of the placing column (a half-shaft gear can be stably placed in the placing rack after being sleeved with a compensation sleeve, a half-shaft gear is placed in the placing rack through a furnace door on the quenching furnace, then the furnace door is closed, then the quenching furnace is pumped by a pumping pipe, so that the interior of the quenching furnace is in a low-pressure state, a telescopic cylinder at the top end of the quenching furnace extends downwards so that a resistance-type heating coil at the bottom end of a motor is positioned in an inner spline of the half-shaft gear, the resistance-type heating coil heats the inner spline by heat radiation after being electrified and heated, and simultaneously the motor is started to drive the resistance-type heating coil to rotate, thereby preventing the problem that the inner spline is heated unevenly, the first branch pipe leads propane and other carburizing gases to the tangential direction of the placing column through the air inlet pipe, so that the carburizing gases rise spirally, and the carburizing gases rise uniformly to the position of the internal spline after rising to the height of one end (the air exhaust pipe continuously exhausts air to keep the low-pressure state in the quenching furnace), thereby ensuring the quantity and the uniformity of the carburizing gases at the position of the internal spline and improving the carburizing effect of the internal spline; after carburization is finished, the first branch pipe is closed, the resistance heating coil is powered off, the telescopic rod is contracted, then quenching gas such as high-pressure high-purity nitrogen is introduced into the second branch pipe along the tangential direction of the quenching furnace through the air inlet pipe, the quenching gas uniformly cools and quenches the inner spline of the semi-axis gear (the air extraction of the air extraction pipe is stopped, so that the pressure in the quenching furnace is gradually increased), and the quenching deformation degree of the inner spline is reduced; and the deformation degree of the internal spline of the gear is further reduced by adopting low-pressure carburization and high-pressure gas quenching, and the yield of the half axle gear is ensured. In addition, the air exhaust pipe on the carburizing and quenching equipment is connected with an air exhaust pump, which is helpful for exhausting the quenching furnace to form a low-pressure state, and the air exhaust pipe is provided with a check valve which can prevent gas from re-entering the quenching furnace from the air exhaust pipe; the first branch pipe and the second branch pipe are both connected with switch valves, and the carburization and quenching of the internal spline of the gear are adjusted by controlling the opening and closing of the two switch valves; the sealing strip is arranged on the furnace door to ensure the sealing of the position of the furnace door, thereby ensuring the low-pressure carburization state in the quenching furnace. Therefore, the invention not only can improve the carburizing effect at the position of the internal spline, but also has the advantage of smaller deformation of the internal spline.

drawings

Fig. 1 is a schematic structural view of the present invention.

The labels in the figures are: 1-a quenching furnace, 2-a placing column, 3-an air exhaust pipe, 4-an air inlet pipe, 5-a first branch pipe, 6-a placing frame, 7-a furnace door, 8-a telescopic cylinder, 9-a motor, 10-a resistance heating coil, 11-an air exhaust pump, 12-a check valve, 13-a switch valve, 14-a sealing strip, 15-a second branch pipe, 16-a pressure gauge and 17-a thermometer.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.