A fixture for heat treatment of automobile gears

Abstract

The present invention relates to the field of quenching technology, and in particular to a fixture for heat treatment of automobile gears, comprising a mounting frame, a quenching pool, and a quenching sensor, etc.; the mounting frame is fixedly connected to the quenching pool; the quenching sensor is fixedly connected to the quenching sensor; and the quenching sensor is fixedly connected to the induction coil. The present invention rotates an auger loader to absorb quenching liquid in the quenching pool, so that the quenching liquid around the gear flows into the second connecting tube, the first connecting tube, and the first telescopic tube, and is discharged to the bottom of the quenching pool through the filter screen on the first telescopic tube. During the quenching process, the quenching liquid absorbed by the auger loader is the quenching liquid at room temperature in the upper part of the quenching pool, so that the quenching liquid that exchanges heat with the gear during the quenching process has enough time to exchange heat with the quenching liquid at the bottom of the quenching pool. In this way, the temperature of the gear is quickly reduced by the quenching liquid circulating around the gear, and the temperature of the gear quenching area is prevented from rising rapidly by the circulating quenching liquid.

Description

Technical Field

[0001] The present invention relates to the technical field of quenching, in particular to a fixture for heat treatment of automobile gears. Background Art

[0002] During the gear processing, in order to improve the mechanical properties of the gear and ensure its working reliability, the gear needs to be heat treated after it is processed and formed. During the continuous heat treatment of the gear, due to the short interval of gear quenching, the temperature of the quenching liquid around the gear rises, and it cannot quickly exchange heat and cool with other quenching liquids in the quenching pool. As a result, during the subsequent gear quenching, the quenching liquid is in a high temperature state. The temperature of the quenching liquid will affect the quenching effect of the gear, specifically affecting the cooling of the gear, resulting in reduced hardenability of the gear and uneven hardening layer, and oxide scale will be generated on the surface of the gear during the heating process. During the quenching process, the oxide scale will detach from the gear surface and enter the quenching liquid. The oxide scale will accumulate in the quenching liquid, affecting the quenching work of the gear. If the quenching liquid is not cleaned and replaced in time, the subsequent quenching liquid work will be affected. Summary of the Invention

[0003] In order to overcome the disadvantages that during the continuous heat treatment of gears, due to the short gear quenching interval, the quenching liquid around the gear cannot quickly exchange heat and cool with other quenching liquids in the quenching pool after the temperature rises, resulting in the quenching liquid being in a high temperature state during subsequent gear quenching, affecting the cooling of the gear and causing the gear hardenability to decrease and the hardened layer to be uneven, the present invention provides a fixture for automobile gear heat treatment processing.

[0004] The technical implementation scheme of the present invention is: a fixture for heat treatment of automobile gears, including a mounting frame, a quenching pool and a quenching sensor; the mounting frame is fixedly connected to the quenching pool; the quenching sensor is fixedly connected to the quenching sensor; the quenching sensor is fixedly connected to the induction coil; it also includes a first connecting tube, an electric slide rail, an electric slider, a connecting rod, a waterproof shell, a DD motor, a second connecting tube, a supporting block, an auger loader, a first telescopic tube and a dirt collecting box; a plurality of electric slide rails are fixedly connected inside the mounting frame; each electric slide rail is slidably connected to an electric slider; each electric slider is fixedly connected to a connecting rod; all the connecting rods are fixedly connected together There is a waterproof shell; a second connecting tube is fixedly connected to the waterproof shell; a supporting block is fixedly connected to the second connecting tube; a DD motor is fixedly connected inside the waterproof shell, and the DD motor is waterproofed by the waterproof shell; a first connecting tube is fixedly connected to the output shaft of the DD motor, and the first connecting tube is connected to the second connecting tube; a auger loader is fixedly connected to the first connecting tube; the auger loader is in contact with the second connecting tube; a first telescopic tube is fixedly connected to the waterproof shell, and the first telescopic tube is connected to the first connecting tube; the first telescopic tube is fixedly connected to the quenching pool; a dirt collecting box is fixedly connected to the quenching pool; the dirt collecting box is connected to the first telescopic tube, and a solenoid valve is provided in the first telescopic tube.

[0005] Optionally, a rubber block is provided at the upper end of the second connecting cylinder, and the gear is fixed by the elasticity of the rubber block.

[0006] Optionally, a rubber sleeve is provided on the surface of the second connecting cylinder.

[0007] Optionally, a plurality of drain outlets are provided on the first telescopic tube, and a filter is provided on each drain outlet.

[0008] Optionally, a cleaning component 1 is also included, which includes a connecting plate, a limiting cylinder and bristles; several connecting plates are fixedly connected to the inside of the quenching pool; all the connecting plates are commonly connected to the limiting cylinder, and the limiting cylinder is slidably connected to the second connecting cylinder; several annular arrays of bristles are fixedly connected inside the limiting cylinder.

[0009] Optionally, the bristles are made of heat-resistant silicone material.

[0010] Optionally, a cleaning component 2 is also included, which includes a second telescopic tube, an extrusion plate, a spring limiting rod and a sealing plate; the second telescopic tube is fixedly connected to the limiting tube; the second telescopic tube is communicated with the first telescopic tube; the second telescopic tube is fixedly connected to the connecting rod; all the connecting rods are fixedly connected to a number of extrusion plates; a number of spring limiting rods are passed through the limiting tube; and the sealing plate is fixedly connected to the telescopic rods on all the spring limiting rods.

[0011] Optionally, several limiting cylinders are provided.

[0012] Optionally, an arc-shaped structure is provided on the sealing plate.

[0013] Optionally, a rubber structure that fits the through hole is provided at the lower portion of the blocking plate.

[0014] Compared with the prior art, the present invention has the following advantages: 1. The present invention absorbs the quenching liquid in the quenching pool by rotating the auger loader, so that the quenching liquid around the gear flows into the second connecting tube, and the quenching liquid in the second connecting tube flows from top to bottom, and then the quenching liquid in the second connecting tube flows into the first connecting tube, and then the quenching liquid in the first connecting tube flows into the first telescopic tube, and is discharged to the bottom of the quenching pool through the filter screen on the first telescopic tube, so that the quenching liquid that exchanges heat with the gear during the quenching process exchanges heat with the quenching liquid at the bottom of the quenching pool, and during the quenching process, the quenching liquid absorbed by the auger loader is the quenching liquid at room temperature in the upper part of the quenching pool, so that the quenching liquid that exchanges heat with the gear during the quenching process and the quenching liquid at the bottom of the quenching pool have enough time to exchange heat, so that the quenching liquid circulating around the gear quickly reduces the temperature of the gear, and the circulating quenching liquid prevents the temperature of the gear quenching area from rising rapidly;

[0015] 2. The present invention causes the supporting block and the gear to move back and forth up and down in the limiting cylinder, which drives the gear to contact the bristles and brush the oxide sheets thereon, so that the stubborn oxide sheets are separated from the gear. At the same time, the gear moving up and down continuously squeezes the quenching liquid in the limiting cylinder, so that the quenching liquid in the limiting cylinder is pressed upward by the gear, thereby accelerating the flow of the quenching liquid in the limiting cylinder through the gear moving up and down, and accelerating the cooling speed of the quenching liquid on the gear. At the same time, when the quenching liquid in the limiting cylinder is pressed upward by the gear, the quenching liquid will flush the oxide scale at the bottom of the gear, causing the oxide scale to move upward, and then enter the first telescopic tube under the cooperation of the second connecting tube and the auger loader, and then enter the dirt collecting box through the first telescopic tube. In this way, during the gear quenching process, the oxide scale on the gear is ensured to be cleaned and the cooling of the gear is accelerated.

[0016] 3. The present invention scrapes the residual oxide scale on the bristles through the blocking plate to ensure that the bristles clean the stubborn oxide scale on the subsequent gears. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of a fixture for heat treatment of automobile gears according to the present invention;

[0018] Figure 2 This is a schematic diagram of the internal structure of the fixture for heat treatment of automobile gears of the present invention;

[0019] Figure 3 This is a schematic diagram of the combined structure of the second connecting cylinder, the supporting block, the auger loader and the first telescopic tube of the fixture for heat treatment of automobile gears of the present invention;

[0020] Figure 4 This is a schematic structural diagram of a cleaning assembly 1 of a fixture for heat treatment of automobile gears according to the present invention;

[0021] Figure 5 This is a schematic diagram of the combined structure of the first telescopic tube, the limiting cylinder, and the second telescopic tube of the fixture for heat treatment of automobile gears of the present invention;

[0022] Figure 6 This is a schematic diagram of the combined structure of the first telescopic tube, cleaning component 1 and cleaning component 2 of the fixture for heat treatment of automobile gears of the present invention.

[0023] The markings of the components in the accompanying drawings are as follows: 001-gear, 1-mounting frame, 2-quenching pool, 3-quenching sensor, 3001-induction coil, 4-first connecting tube, 5-electric slide rail, 6-electric slider, 7-connecting rod, 8-waterproof shell, 9-DD motor, 10-second connecting tube, 11-supporting block, 12-auger loader, 13-first telescopic tube, 13001-filter, 14-dirt collecting box, 101-connecting plate, 102-limiting tube, 102001-through hole, 103-brush, 201-second telescopic tube, 202-extrusion plate, 203-spring limiting rod, 204-sealing plate. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby stated that any directional terms such as "up," "down," "left," "right," "front," "back," "inside," and "outside" that appear or will appear herein are based solely on the accompanying drawings and are not intended to limit the present invention.

[0025] Example 1

[0026] A fixture for heat treatment of automobile gears, such as Figure 1-3 As shown, it includes a mounting frame 1, a quenching pool 2 and a quenching sensor 3; the mounting frame 1 is bolted to the quenching pool 2; the quenching sensor 3 is bolted to the quenching pool 2; the quenching sensor 3 is fixedly connected to the induction coil 3001;

[0027] It also includes a first connecting tube 4, an electric slide rail 5, an electric slider 6, a connecting rod 7, a waterproof shell 8, a DD motor 9, a second connecting tube 10, a supporting block 11, an auger loader 12, a first telescopic tube 13 and a dirt collecting box 14; the internal bolt connection of the mounting frame 1 is connected to two symmetrically arranged electric slide rails 5; each electric slide rail 5 is slidably connected to an electric slider 6; each electric slider 6 is fixedly connected to a connecting rod 7; all the connecting rods 7 are fixedly connected to the waterproof shell 8; the waterproof shell 8 is fixedly connected to the second connecting tube 10; the second connecting tube 10 is fixedly connected to the supporting block 11; the waterproof shell 8 is bolted to the inner side of the mounting frame 1. It is connected to a DD motor 9, which is waterproofed by a waterproof shell 8; a first connecting tube 4 is fixedly connected to the output shaft of the DD motor 9, and the first connecting tube 4 is connected to the second connecting tube 10; an auger loader 12 is fixedly connected to the first connecting tube 4; the auger loader 12 is in contact with the second connecting tube 10; a first telescopic tube 13 is fixedly connected to the waterproof shell 8, and the first telescopic tube 13 is connected to the first connecting tube 4; the first telescopic tube 13 is fixedly connected to the quenching pool 2; a dirt collecting box 14 is bolted to the quenching pool 2; the dirt collecting box 14 is connected to the first telescopic tube 13, and a solenoid valve is provided in the first telescopic tube 13.

[0028] A rubber block is provided at the upper end of the second connecting tube 10, and the gear 001 is fixed by the elasticity of the rubber block.

[0029] The surface of the second connecting tube 10 is equipped with a rubber sleeve for fitting with the waterproof shell 8 to enhance the waterproof effect.

[0030] The first telescopic tube 13 is connected to a drain port in a circular array, and each drain port is provided with a filter screen 13001 for limiting the position of the oxide scale.

[0031] First, the gear 001 is mounted on the supporting block 11 by an external clamping transfer device, and the gear 001 is fixed by a rubber block provided on the surface of the second connecting tube 10, and then the quenching sensor 3 is controlled to operate and a high-frequency AC electromagnetic field is passed to the induction coil 3001. Since the gear 001 is located in the induction coil 3001, that is, the electromagnetic eddy current is on the gear 001, and since the gear 001 has the effect of resistance, the gear 001 generates heat, and the surface temperature of the gear 001 rises rapidly, that is, the gear 001 is heated. After the heating is completed, the two electric sliders 6 are controlled to slide downward on the two electric slide rails 5, and the two electric sliders 6 drive the two connecting rods 7 to move downward, and the connecting rod 7 drives the waterproof shell 8 to move downward, and the waterproof shell 8 is heated. The shell 8 drives the components connected to it to move downward, that is, the waterproof shell 8 drives the DD motor 9, the second connecting tube 10 and the supporting block 11 to move downward, and compresses the first telescopic tube 13 through the waterproof shell 8, while driving the gear 001 fixed on the supporting block 11 to move downward into the quenching pool 2, so that the gear 001 contacts the quenching liquid in the quenching pool 2 for quenching; during the continuous heat treatment process of the gear 001, due to the short quenching interval of the gear 001, after the temperature of the quenching liquid around the gear 001 rises, it cannot quickly exchange heat and cool with other quenching liquids in the quenching pool 2, resulting in the quenching liquid being in a high temperature state when the gear 001 is subsequently quenched, affecting the cooling of the gear 001, reducing the hardenability of the gear 001 and making the hardened layer uneven.

[0032] Therefore, during the quenching process of gear 001, first, after gear 001 moves downward into the quenching pool 2, the upper end of the second connecting tube 10 is located in the quenching liquid. During this process, the DD motor 9 drives the first connecting tube 4 to rotate, and the first connecting tube 4 drives the auger loader 12 to rotate, that is, the quenching liquid in the quenching pool 2 is absorbed by the auger loader 12, so that the quenching liquid around the gear 001 flows into the second connecting tube 10, and the quenching liquid in the second connecting tube 10 flows from top to bottom, and then the quenching liquid in the second connecting tube 10 flows into the first connecting tube 4, and then the quenching liquid in the first connecting tube 4 flows into The quenching liquid is sucked into the first telescopic tube 13 and discharged to the bottom of the quenching pool 2 through the filter 13001 on the first telescopic tube 13, so that the quenching liquid that exchanges heat with the gear 001 during the quenching process exchanges heat with the quenching liquid at the bottom of the quenching pool 2. During the quenching process, the quenching liquid sucked by the auger loader 12 is the quenching liquid at room temperature in the upper part of the quenching pool 2, so that the quenching liquid that exchanges heat with the gear 001 during the quenching process has enough time to exchange heat with the quenching liquid at the bottom of the quenching pool 2. In this way, the quenching liquid circulating around the gear 001 quickly lowers the gear 00114; the dirt collecting box 14 is connected to the first telescopic tube 13, and an electromagnetic valve is provided in the first telescopic tube 13.

[0033] A rubber block is provided at the upper end of the second connecting tube 10, and the gear 001 is fixed by the elasticity of the rubber block.

[0034] The surface of the second connecting tube 10 is equipped with a rubber sleeve for fitting with the waterproof shell 8 to enhance the waterproof effect.

[0035] The first telescopic tube 13 is connected to a drain port in a circular array, and each drain port is provided with a filter screen 13001 for limiting the position of the oxide scale.

[0036] First, the gear 001 is mounted on the supporting block 11 by an external clamping transfer device, and the gear 001 is fixed by a rubber block provided on the surface of the second connecting tube 10, and then the quenching sensor 3 is controlled to operate and a high-frequency AC electromagnetic field is passed to the induction coil 3001. Since the gear 001 is located in the induction coil 3001, that is, the electromagnetic eddy current is on the gear 001, and since the gear 001 has the effect of resistance, the gear 001 generates heat, and the surface temperature of the gear 001 rises rapidly, that is, the gear 001 is heated. After the heating is completed, the two electric sliders 6 are controlled to slide downward on the two electric slide rails 5, and the two electric sliders 6 drive the two connecting rods 7 to move downward, and the connecting rod 7 drives the waterproof shell 8 to move downward, and the waterproof shell 8 is heated. The shell 8 drives the components connected to it to move downward, that is, the waterproof shell 8 drives the DD motor 9, the second connecting tube 10 and the supporting block 11 to move downward, and compresses the first telescopic tube 13 through the waterproof shell 8, while driving the gear 001 fixed on the supporting block 11 to move downward into the quenching pool 2, so that the gear 001 contacts the quenching liquid in the quenching pool 2 for quenching; during the continuous heat treatment process of the gear 001, due to the short quenching interval of the gear 001, after the temperature of the quenching liquid around the gear 001 rises, it cannot quickly exchange heat and cool with other quenching liquids in the quenching pool 2, resulting in the quenching liquid being in a high temperature state when the gear 001 is subsequently quenched, affecting the cooling of the gear 001, reducing the hardenability of the gear 001 and making the hardened layer uneven.

[0037] Therefore, during the quenching process of gear 001, first, after gear 001 moves downward into the quenching pool 2, the upper end of the second connecting tube 10 is located in the quenching liquid. During this process, the DD motor 9 drives the first connecting tube 4 to rotate, and the first connecting tube 4 drives the auger loader 12 to rotate, that is, the quenching liquid in the quenching pool 2 is absorbed by the auger loader 12, so that the quenching liquid around the gear 001 flows into the second connecting tube 10, and the quenching liquid in the second connecting tube 10 flows from top to bottom, and then the quenching liquid in the second connecting tube 10 flows into the first connecting tube 4, and then the quenching liquid in the first connecting tube 4 flows into the first telescopic tube 1 3, and is discharged to the bottom of the quenching pool 2 through the filter screen 13001 on the first telescopic tube 13, so that the quenching liquid that exchanges heat with the gear 001 during the quenching process exchanges heat with the quenching liquid at the bottom of the quenching pool 2, and during the quenching process, the quenching liquid sucked by the auger loader 12 is the quenching liquid at room temperature in the upper part of the quenching pool 2, so that the quenching liquid that exchanges heat with the gear 001 during the quenching process and the quenching liquid at the bottom of the quenching pool 2 have enough time to exchange heat, so that the quenching liquid circulating around the gear 001 quickly lowers the gear 001. In this way, during the quenching process of the gear 001, it is ensured that the oxide scale on the gear 001 is cleaned and the cooling of the gear 001 is accelerated.

[0038] Example 3

[0039] On the basis of the above embodiment 2, Figure 5-6 As shown, it also includes a cleaning component 2, which includes a second telescopic tube 201, an extrusion plate 202, a spring limiting rod 203 and a blocking plate 204; the second telescopic tube 201 is fixedly connected to the limiting tube 102; the second telescopic tube 201 is communicated with the first telescopic tube 13; the second telescopic tube 201 is fixedly connected to the connecting rod 7; all the connecting rods 7 are fixedly connected to two symmetrically arranged extrusion plates 202; twelve spring limiting rods 203 in an annular array are passed through the limiting tube 102; and the blocking plate 204 is fixedly connected to the telescopic rods on all the spring limiting rods 203.

[0040] The limiting cylinder 102 is provided with six through holes 102001 in a circular array for cooperating with the sealing plate 204 to clean the oxide scale.

[0041] The sealing plate 204 is provided with an arc structure for guiding the oxide scale.

[0042] The lower part of the blocking plate 204 is provided with a rubber structure that fits the through hole 102001 to enhance the blocking effect of the through hole 102001.

[0043] During the quenching process, in the initial state, the spring limit rod 203 is in a compressed state, and the spring limit rod 203 initially drives the sealing plate 204 to be located in the middle and upper part of the limit cylinder 102. After the electric slider 6 and the connecting rod 7 drive the gear 001 into the quenching liquid, the connecting rod 7 synchronously drives the extrusion plate 202 to move downward, so that the spring limit rod 203 extends and drives the sealing plate 204 to move downward to block the through hole 102001, so that the limit cylinder 102 forms a semi-closed cylinder to ensure the cleaning operation of the stubborn oxide scale of the gear 001 in Example 2. It should be noted that after the gear 001 enters the quenching liquid, the connecting rod 7 and the extrusion plate 202 are away from the spring limit rod 203. When the gear 001 moves back and forth up and down, the connecting rod 7 and the extrusion plate 202 still remain away from the spring limit rod 203.

[0044] After completing the quenching work, control the electric slider 6 to move upward on the electric slide rail 5, and then the electric slider 6 drives the connecting rod 7 to move upward, and the connecting rod 7 drives the extrusion plate 202 to move upward close to and push the limit rod on the spring limit rod 203, and squeeze the spring on the spring limit rod 203, and then the limit rod on the spring limit rod 203 pushes the blocking plate 204 to move upward, so that the through hole 102001 loses its limit, and scrapes the residual oxide scale on the bristles 103 on the blocking plate 204 to ensure that the bristles 103 clean the stubborn oxide scale on the subsequent gear 001, and then the oxide scale passes through the through hole 102001 downward into the second telescopic tube 201, and then enters the first telescopic tube 13 through the second telescopic tube 201, and finally enters the dirt collecting box 14 for collection.

[0045] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fixture for heat treatment of automobile gears, comprising a mounting frame (1), a quenching pool (2) and a quenching sensor (3); the mounting frame (1) is fixedly connected to the quenching pool (2); the quenching sensor (3) is fixedly connected to the quenching pool (2); the quenching sensor (3) is fixedly connected to the induction coil (3001); characterized in that, The utility model also includes a first connecting tube (4), an electric slide rail (5), an electric slider (6), a connecting rod (7), a waterproof shell (8), a DD motor (9), a second connecting tube (10), a supporting block (11), an auger loader (12), a first telescopic tube (13) and a dirt collecting box (14); a plurality of electric slide rails (5) are fixedly connected inside the mounting frame (1); each electric slide rail (5) is slidably connected to an electric slider (6); each electric slider (6) is fixedly connected to a connecting rod (7); all the connecting rods (7) are fixedly connected to the waterproof shell (8); the waterproof shell (8) is fixedly connected to the second connecting tube (10); the second connecting tube (10) is fixedly connected to the supporting block (11); the waterproof shell (8) is fixedly connected to the connecting rod (7). A DD motor (9) is connected, and the DD motor (9) is waterproofed and protected by a waterproof shell (8); a first connecting tube (4) is fixedly connected to the output shaft of the DD motor (9), and the first connecting tube (4) is communicated with the second connecting tube (10); a auger loader (12) is fixedly connected to the first connecting tube (4); the auger loader (12) is in contact with the second connecting tube (10); a first telescopic tube (13) is fixedly connected to the waterproof shell (8), and the first telescopic tube (13) is communicated with the first connecting tube (4); the first telescopic tube (13) is fixedly connected to the quenching tank (2); a dirt collecting box (14) is fixedly connected to the quenching tank (2); the dirt collecting box (14) is communicated with the first telescopic tube (13), and a solenoid valve is provided in the first telescopic tube (13); The first telescopic tube (13) is connected to a plurality of drain outlets, and each drain outlet is provided with a filter screen (13001); The cleaning assembly includes a first cleaning component, which includes a connecting plate (101), a limiting cylinder (102) and bristles (103); a plurality of connecting plates (101) are fixedly connected inside the quenching pool (2); all the connecting plates (101) are commonly connected to the limiting cylinder (102), and the limiting cylinder (102) is slidably connected to the second connecting cylinder (10); a plurality of bristles (103) in an annular array are fixedly connected inside the limiting cylinder (102); The cleaning assembly also includes a second cleaning assembly, which includes a second telescopic tube (201), an extrusion plate (202), a spring limiting rod (203) and a blocking plate (204); the second telescopic tube (201) is fixedly connected to the limiting tube (102); the second telescopic tube (201) is communicated with the first telescopic tube (13); the second telescopic tube (201) is fixedly connected to the connecting rod (7); all the connecting rods (7) are fixedly connected to a plurality of extrusion plates (202); a plurality of spring limiting rods (203) are passed through the limiting tube (102); and the blocking plate (204) is fixedly connected to the telescopic rods on all the spring limiting rods (203).

2. A fixture for heat treatment of automobile gears according to claim 1, characterized in that: A rubber block is provided at the upper end of the second connecting cylinder (10), and the gear (001) is fixed by the elasticity of the rubber block.

3. A fixture for heat treatment of automobile gears according to claim 2, characterized in that: The surface of the second connecting cylinder (10) is equipped with a rubber sleeve.

4. The fixture for heat treatment of automobile gears according to claim 1, characterized in that: The bristles (103) are made of heat-resistant silicone material.

5. The fixture for heat treatment of automobile gears according to claim 1, characterized in that: The limiting cylinder (102) is provided with a plurality of through holes (102001) in an annular array.

6. The fixture for heat treatment of automobile gears according to claim 1, characterized in that: The blocking plate (204) is provided with an arc-shaped structure.

7. A fixture for heat treatment of automobile gears according to claim 6, characterized in that: The lower portion of the blocking plate (204) is provided with a rubber structure that fits the through hole (102001).

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