CN110205470A - A kind of fixture of heat treatment of thin-wall annular gear - Google Patents

Abstract

The invention relates to a heat treatment fixture for a thin-walled inner gear ring, which comprises a T-shaped cylindrical base, a pressing end surface of a tooth top, a directional moving chute, a pressing connecting rod, a synchronous pressing ring of the connecting rod, and a pressing end of the upper end of the ring gear. cover. The characteristics of this heat treatment fixture are: on the T-shaped cylindrical table, holes are opened according to the parameters such as the tooth height of the inner ring gear to promote the circulation of the heat treatment chemical gas; on the T-shaped cylindrical table, a positioning groove is opened, and the tooth top is pressed through the positioning key. , to realize the adjustability of the pressing end surface of the addendum, and at the same time connect the three pressing end surfaces of the tooth top to the pressing ring through the connecting rod mechanism, and realize the position control of the pressing end surface through the upper end pressing end cover. The invention realizes the controllability of the compressive stress at the top end of the ring gear. By controlling the pressing end surface of the tooth end and the cooperative clamping control of the pressing ring at the upper end of the ring gear, it can well prevent the thin-walled inner ring gear from being damaged during the heat treatment process. The core size of the tooth surface is deformed, the shrinkage of the upper and lower ring gears is not synchronized, and the ring gear is axially twisted and other deformation problems.

Description

A heat treatment fixture for thin-walled inner ring gear

technical field

The invention relates to the technical field of heat treatment fixtures for gears, in particular to a heat treatment fixture for thin-walled internal gears, which is suitable for use in heat treatment processes such as deep carbon, deep nitrogen, and cyanide for thin-walled internal gears.

Background technique

High-precision thin-walled internal ring gears are mainly used in aero-engine gear reducers and helicopter main reducers. For example, the latest generation of GTF aero-engines adds a herringbone planetary gear reducer between the turbine rotor and the tail fan. The transmission power is required to reach 20-40MW, the transmission efficiency is required to be ≥99%, and the processing accuracy of the herringbone gear and the ring gear is required to reach GB4. Among them, the radial size of the ring gear is large, and the thin wall of the ring gear leads to low overall strength and stiffness. During the heat treatment process of tooth surface strengthening, the ring gear is prone to deformation such as warping, local expansion, local shrinkage, and axial direction torque. Due to the high machining accuracy requirements of the ring gear and the small cutting allowance, once the heat treatment deformation of the ring gear is too large, it will directly lead to the scrapping of the parts, and it is impossible to enter the next step of precision grinding and assembly and debugging. Therefore, how to design a set of fixtures with simple structure, convenient clamping, and control of ring gear heat treatment deformation is a technical problem in the ring gear heat treatment process.

Contents of the invention

The technical problem to be solved by the present invention is: how to design the thin-walled inner ring gear fixture to reduce the heat treatment deformation of the part and ensure that the deformation amount and deformation mode of the part are controllable in view of the problem that the deformation of the thin-walled inner ring gear seriously affects the processing accuracy. To solve the technical problems, a heat treatment fixture for thin-walled inner ring gears was designed.

The object of the present invention is to provide a heat treatment jig for a thin-walled inner ring gear. The jig is designed to be a heat treatment jig for an inner ring gear with a compact structure and convenient clamping according to the structural characteristics of a thin-walled inner ring gear. At the same time, it is ensured that in the heat treatment process, the influence of deformation due to heat treatment is reduced, and a thin-walled inner ring gear that meets the requirements of deformation control is produced.

The technical solution of the present invention is: a fixture for heat treatment of a thin-walled inner ring gear, which is characterized in that it includes two parts: a bottom core control assembly and a compression end cover assembly.

A fixture for heat treatment of a thin-walled internal gear, characterized in that the fixture includes a T-shaped cylindrical base, a tooth top pressing end surface, an upper end of the ring gear pressing end cover assembly, and a linkage assembly, and one end of the T-shaped cylindrical base is set There is a through hole that can be installed on the heat treatment furnace, and the other end is installed with an annular boss of a thin-walled inner gear ring. The annular boss is provided with a tooth top pressing end surface, and three evenly distributed tooth top pressing end surfaces are realized through a linkage mechanism while pressing.

The dimension x of the clamping surface clearance (1) is calculated according to the tooth thickness and tooth space width.

The diameter d and number N of the chemical gas circulation holes (3) are calculated according to the tooth height of the ring gear.

There are three uniformly distributed tooth top pressing end surfaces (6) and positioning chute (3).

The connecting rod synchronous pressing ring (10) is simultaneously connected with three directional sliders (4) through the connecting rod to realize the joint and ensure that the three tooth tops press the end face and press the ring gear tooth top at the same time.

The upper end of the compression end cover (13) at the upper end of the ring gear is designed to be hollowed out to reduce weight, and the compression end surface and the positioning sleeve (15) are connected by 4 ribs (14).

The jig body of the present invention is designed with a T-shaped cylindrical base, and the thin-walled inner ring gear to be heat-treated is installed on the jig by pressing the end face of the tooth top to realize effective radial and axial positioning. Due to the supporting effect of the T-shaped cylindrical base of the clamp body ring, the radial deformation caused by the large radial size of the part during heat treatment can be reduced. The chuck body is provided with ventilation holes at the circumferential position (the position of the ring gear teeth), in order to increase the exchange of chemical gas with the tooth surface. A positioning slot is opened on the bottom surface of the T-shaped cylindrical platform, and the tooth top pressing end surface is linked with the positioning key to realize the adjustable tooth top pressing end surface. At the same time, the three tooth top pressing end surfaces are connected to the pressing On the ring, the control of the tooth top surface of the ring gear is realized by pressing the end cover from the upper end of the ring gear from above. During use, the control of the clamping position and clamping force of the tooth top of the inner ring gear can be realized by changing the position of the synchronous pressing ring of the connecting rod, and the process is simple and the operation is convenient. The directional moving slider and the pressing end surface of the tooth top are arranged in three evenly distributed, which can realize accurate positioning of parts and reliable locking. There are 4 reinforcing ribs evenly distributed on the compression end cover, which can greatly reduce the weight of the compression end cover and improve the convenience of operation. The invention has the advantages of compact structure, convenient clamping, and overcomes the deformation control in the carburizing, deep nitrogen and cyanide heat treatment processes of the thin-walled inner ring gear. At the same time, the present invention can also be applied to the heat treatment process of other types of ring gear parts.

The calculation formula of the specific parameters of the clamp is as follows

x=πm

d=2m

N=[2Z/3]

In the formula: m is the modulus of the tooth of the inner ring gear, and Z is the number of teeth of the inner ring gear.

Description of drawings

Figure 1 is a schematic diagram of the bottom core control component of the thin-walled inner ring gear heat treatment fixture;

In the figure: 1. Clamping surface gap, 2. T-shaped cylindrical base, 3. Chemical gas flow hole, 4. Orientation moving slider, 5. Connecting rod, 6. Tooth top pressing end face, 7. Connecting bolt, 8. Compression connecting rod, 9, connecting bolt, 10, connecting rod synchronous pressing ring, 11, column, 12, positioning chute.

Fig. 2 is a schematic diagram of a heat treatment fixture for a thin-walled inner ring gear to compress an end cover assembly;

Among the figure: 13, the upper end of the ring gear compresses the end cap, 14, compresses the reinforcing rib of the end cap, and 15, compresses the positioning sleeve of the end cap.

Fig. 3 is a schematic diagram of the assembly of the heat treatment fixture for the thin-walled inner ring gear.

Detailed ways

A heat treatment fixture for a thin-walled inner ring gear is composed of two parts: a bottom core control assembly and a compression end cover assembly. The specific parts are: T-shaped cylindrical base 2, tooth top pressing end face 6, ring gear upper end pressing end cover assembly 13, 14, 15, linkage assembly 4, 5, 7, 8, 9, 10, the T-shaped One end of the cylindrical base 2 is provided with a through hole that can be installed on the heat treatment furnace, and the other end is installed with an annular boss of a thin-walled inner ring gear. The annular boss is provided with a tooth top pressing end surface 6, and three joints are realized through a linkage mechanism. Evenly distributed tooth tops are pressed against the end face at the same time.

When in use, first fix the T-shaped cylindrical base on the base of the heat treatment furnace through the bottom to ensure that the T-shaped cylindrical base does not shift radially.

Then install the three addendum pressing end surfaces 6 on the T-shaped cylindrical base respectively, and insert the directional moving slider 4 into the positioning chute 12 to ensure that the directional slider 4 drives the addendum pressing end surfaces 6 to slide freely in the groove.

Use the connecting bolt 7 to connect the compression link 8 and the connecting rod 5 together to ensure that the compression link 8 can rotate freely.

Assemble the connecting rod synchronous pressing ring 10 on the column 11, and use the connecting bolts 9 to hinge the three compression connecting rods 8 and the connecting rod synchronous pressing ring 10 together. By pulling and pressing the connecting rod synchronously pressing the ring 10, observe whether the movement of the three tooth top pressing end faces 6 is consistent.

If the movements of the pressing end surfaces 6 of the three tooth tops are not consistent, adjust the connecting bolts 7 and 9 at both ends of the pressing connecting rod 8 to achieve consistent movement of the pressing end surfaces of the tooth tops, and the tooth top surface of the inner ring gear has been achieved. Simultaneous compression.

After completing the installation of the core control components at the bottom, install the thin-walled inner ring gear on the clamp body, and use a mallet to fine-tune the general position of the inner ring gear on the clamp body.

Install the compression end cover assembly on the column row, and use the gravity of the compression end cover assembly itself and apply pressure from above, so that the positioning sleeve hole 15 of the compression end cover is in contact with the synchronous pressure applying ring 10 of the connecting rod, pushing the top of the tooth to compress The end face 6 clamps the tooth top face of the ring gear. Simultaneously, the upper end surface of the inner ring gear is restrained by using the upper end of the ring gear to compress the end cover 13 .

After the assembly is completed, the fixture and the ring gear are placed in a heat treatment furnace for chemical heat treatment. After the heat treatment is completed, grab the reinforcement rib 14 of the compression end cover, move upward to remove the compression end cover assembly, shrink the addendum compression end surface 6 inward, and then remove the inner ring gear. Complete the heat treatment process of the thin-walled inner ring gear.

The invention has the advantages of compact structure, convenient clamping, and overcomes the deformation control in the carburizing, deep nitrogen and cyanide heat treatment processes of the thin-walled inner ring gear. At the same time, the present invention can also be applied to the heat treatment process of other types of ring gear parts.

Parts not described in detail in the present invention belong to the well-known technology in the art. All technical solutions formed by equivalent transformation or equivalent replacement fall within the protection scope of the present invention.

Claims (6)

1. a kind of fixture of heat treatment of thin-wall annular gear, which is characterized in that fixture includes T-type cylindrical seat (2), tooth top compression end Face (6), gear ring upper end compress end-cap assembly (13,14,15), linkage unit (4,5,7,8,9,10), the T-type cylindrical seat (2) one end is provided with the through-hole that may be mounted on heat-treatment furnace, and the other end installs the annular convex platform of thin-wall annular gear, ring It is provided with tooth top pressure side surface (6) on shape boss, is compressed while realizing 3 even teeth top pressure side surfaces by linkage mechanism.

2. the fixture of heat treatment of thin-wall annular gear as described in claim 1, which is characterized in that described steps up face gap (1) Size x is calculated according to transverse tooth thickness and space width.

3. the fixture of heat treatment of thin-wall annular gear as described in claim 1, which is characterized in that the chemical gas recirculation hole (3) diameter d and number N is calculated according to ring gear tooth height.

4. the fixture of heat treatment of thin-wall annular gear as described in claim 1, which is characterized in that the tooth top pressure side surface (6) and uniformly distributed 3 of positioning runner (3).

5. the fixture of heat treatment of thin-wall annular gear as described in claim 1, which is characterized in that the synchronous pressure circle of the connecting rod Ring (10) connects 3 orientation sliding blocks (4) by connecting rod simultaneously, and realization is together with guaranteeing 3 tooth top pressure side surfaces while compressing internal tooth Enclose tooth top.

6. the fixture of heat treatment of thin-wall annular gear as described in claim 1, which is characterized in that the gear ring upper end compression end Lid (13) upper end is to empty loss of weight design, is connected by 4 with reinforcing rib (14) between pressure side surface and positioning sets of holes (15).