CN110408885B - Light gear for vehicle and manufacturing process thereof - Google Patents

Light gear for vehicle and manufacturing process thereof Download PDF

Info

Publication number
CN110408885B
CN110408885B CN201910794144.1A CN201910794144A CN110408885B CN 110408885 B CN110408885 B CN 110408885B CN 201910794144 A CN201910794144 A CN 201910794144A CN 110408885 B CN110408885 B CN 110408885B
Authority
CN
China
Prior art keywords
gear
semi
treatment
finished
blank
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910794144.1A
Other languages
Chinese (zh)
Other versions
CN110408885A (en
Inventor
赵振东
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nanjing Institute of Technology
Original Assignee
Nanjing Institute of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nanjing Institute of Technology filed Critical Nanjing Institute of Technology
Priority to CN201910794144.1A priority Critical patent/CN110408885B/en
Publication of CN110408885A publication Critical patent/CN110408885A/en
Application granted granted Critical
Publication of CN110408885B publication Critical patent/CN110408885B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B23P15/14—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass gear parts, e.g. gear wheels
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/06—Surface hardening
    • C21D1/09—Surface hardening by direct application of electrical or wave energy; by particle radiation
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C21D1/28—Normalising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/32—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for gear wheels, worm wheels, or the like
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/36—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases using ionised gases, e.g. ionitriding
    • C23C8/38—Treatment of ferrous surfaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
    • F16H55/02—Toothed members; Worms
    • F16H55/06—Use of materials; Use of treatments of toothed members or worms to affect their intrinsic material properties
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
    • F16H55/02—Toothed members; Worms
    • F16H55/17—Toothed wheels

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Organic Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • General Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electromagnetism (AREA)
  • Heat Treatment Of Articles (AREA)
  • Gears, Cams (AREA)

Abstract

The invention discloses a manufacturing process of a light gear for a vehicle, which comprises the following steps: s1, roughly processing the gear raw material to obtain a gear blank with a central large hole; s2, carrying out heat treatment on the gear blank; s3, performing semi-finishing on the gear blank to obtain a gear semi-finished product with a tooth part; s4, carrying out plasma surface quenching carbonitriding treatment and sulfurization treatment on the gear semi-finished product; and S5, performing secondary finish machining on the semi-finished gear to obtain a finished gear. The invention reduces quenching time and energy consumption, reduces surface friction coefficient and improves surface wear resistance through quenching, carbonitriding and sulfurizing treatment on the surface of the tooth part.

Description

Light gear for vehicle and manufacturing process thereof
Technical Field
The invention belongs to the technical field of automobile parts, and particularly relates to a light gear for a vehicle and a manufacturing process thereof.
Background
The gear is a very important part with large use amount in the automobile and is mainly used for transmitting power and adjusting speed or direction. The common stress condition is that the tooth part bears large alternating bending stress, and the tooth surfaces roll and slide mutually and bear contact pressure stress. Therefore, a gear material is required to have high bending fatigue strength and contact fatigue strength, a tooth surface to have high hardness and wear resistance, and a gear core to have certain strength and toughness, and also to have small deformation, high accuracy, and low noise. In addition, the automobile product requires high production efficiency, low energy consumption and low product cost.
The automobile gear can be roughly divided into a light load gear, a medium load gear and a heavy load gear according to different bearing sizes, structures and the like. At present, domestic light gears for vehicles are mostly produced by low-alloy carburizing steel (such as 20Mn2, 20Cr, 20MnV, 20CrV and the like). The traditional manufacturing process sequentially comprises the steps of blanking, blank forging, softening annealing, tempering, machining an inner hole, broaching a key groove, finish turning of an outer end face, tooth inserting (rolling), tooth surface quenching and carburizing, honing, bench work procedures (deburring, cleaning and oiling) and the like, wherein the blank forging energy consumption is high, the time required by the softening annealing is long, the part deformation is large in the tempering process, the decarburization tendency in the tempering heat treatment process is difficult to overcome, and the reserved machining allowance is large, so the material consumption is large. In addition, the strengthening effect is not obvious after the traditional surface quenching such as low-carbon steel induction heating or flame heating. Therefore, the traditional manufacturing method of the light gear needs to be researched and optimized to overcome the defects in the manufacturing process, improve the manufacturing efficiency, further improve the fatigue life of the light gear and reduce the production cost.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a light gear for a vehicle and a manufacturing process thereof, wherein quenching time and energy consumption are reduced, the surface friction coefficient is reduced, and the surface wear resistance is improved through surface quenching, carbonitriding and sulfurization treatment of a tooth part; on the basis, normalizing and high-temperature tempering treatment is further performed, metal grains are refined, the hardness of the material is improved, and heat treatment deformation is reduced; furthermore, the forming time and the energy consumption of the gear are reduced by two machining processes.
In order to solve the problems of the prior art, the invention discloses a manufacturing process of a light gear for a vehicle,
the method comprises the following steps:
s1, roughly processing the gear raw material to obtain a gear blank with a central large hole;
s2, carrying out heat treatment on the gear blank;
s3, performing semi-finishing on the gear blank to obtain a gear semi-finished product with a tooth part;
s4, carrying out plasma surface quenching carbonitriding treatment and sulfurization treatment on the gear semi-finished product;
and S5, performing secondary finish machining on the semi-finished gear to obtain a finished gear.
Further, the air conditioner is provided with a fan,
step S4 further includes the following sub-steps:
s41, heating the surface of the tooth part of the semi-finished gear to 450-650 ℃, and preserving heat for 1-2 hours, wherein nitrogen is used as protective gas in the process, and methane is added into the nitrogen to complete carbonitriding treatment;
s42, cooling the gear semi-finished product to 170-190 ℃, and preserving heat for 2-4 hours to complete the sulfurization treatment, thereby obtaining a sulfurization layer.
Further, the air conditioner is provided with a fan,
step S4 further includes the following sub-steps:
s41, heating the surface of the tooth part of the semi-finished gear to 170-190 ℃, and preserving heat for 2-4 hours to complete sulfurization treatment to obtain a sulfurization layer;
and S42, continuously heating the tooth part of the semi-finished gear to 450-650 ℃, and preserving heat for 1-2 hours, wherein nitrogen is used as protective gas in the process, and methane is added into the nitrogen to finish carbonitriding treatment.
Further, the air conditioner is provided with a fan,
the adding speed of the nitrogen is 50-75 ml/min: the adding speed of the methane is 10-15 ml/min.
Further, the air conditioner is provided with a fan,
step S2 further includes the following sub-steps:
s21, heating the gear blank to the critical temperature Ac3Keeping the temperature for 1-1.5 h at 100-120 ℃ to ensure that the gear blank is cooled to obtain a pearlite structure after being completely austenitized;
s22, heating the gear blank to 500-650 ℃, and preserving heat for 0.5-1 h to obtain the tempered sorbite.
Further, the air conditioner is provided with a fan,
step S1 further includes the following sub-steps:
s11, processing a central small hole on the gear raw material by adopting a fine blanking process, wherein the diameter of the central small hole is 50-70% of the design diameter;
and S12, expanding the small central hole into a large central hole by adopting a fine blanking process, wherein the diameter of the large central hole is slightly smaller than the design diameter.
Further, the air conditioner is provided with a fan,
in step S1, a central large hole is machined in the gear raw material by drilling, boring or milling, and the diameter of the central large hole is slightly smaller than the design diameter.
Further, the air conditioner is provided with a fan,
step S3 includes the following sub-steps:
s31, performing fine machining on the central large hole of the gear blank to obtain a central hole;
s32, processing a key groove on the central hole of the gear blank;
s33, finish turning the end face of the gear blank, and chamfering the outer circle of the end face;
and S34, processing a tooth part on the outer circle of the gear blank, and chamfering the end face of the tooth part.
Further, the air conditioner is provided with a fan,
step S5 includes the following sub-steps:
s51, honing the gear semi-finished product;
and S52, performing bench work treatment on the semi-finished gear to obtain the finished gear.
The invention also discloses a light gear for the vehicle, which is manufactured by the manufacturing process, wherein the length of the central hole of the light gear for the vehicle is as follows: l is more than or equal to 10mm and less than or equal to 30mm, and the length-diameter ratio is as follows: l/d is more than or equal to 0.1 and less than or equal to 1.
The invention has the following beneficial effects:
1. compared with the existing gear manufacturing method, the invention adopts the tooth plasma beam heating surface quenching and carbonitriding process to replace the traditional induction heating or flame heating surface quenching and carburizing/nitriding treatment; the carbonitriding treatment is realized by adding a small amount of methane into nitrogen, which not only meets the oxidation-free protection of plasma beam heating surface quenching, but also is used as a carrier gas for nitriding and carburizing; the plasma beam heating surface quenching speed is high, the ion nitriding time is only 1/4-1/5 of the common gas nitriding time, the organizational structure of the nitriding layer is controllable, the toughness of the ion nitriding layer is good, and in addition, the defects that the energy consumption of the traditional surface quenching such as induction heating or flame heating is high, the part deformation is large and the like are overcome.
2. Compared with the existing gear manufacturing method, the method has the advantages that the low-temperature sulfurization process is added, the temperature of the low-temperature sulfurization is 170-190 ℃, the FeS layer is formed on the surface of the tooth part by utilizing the temperature heated by the previous plasma beam or in the process of heating the plasma beam, the friction coefficient of the surface of the tooth part is reduced, the gear meshing is smoother, the motion noise is reduced, and the wear resistance of the surface of the gear is improved.
3. Compared with the existing gear manufacturing method, the gear forging and annealing softening process is replaced by the machining or secondary fine blanking process, the machining time is far shorter than the forging and annealing softening time, the overall process time is saved by at least 5 hours, the efficiency is improved, and the energy consumption is reduced.
4. Compared with the existing gear manufacturing method, the invention adopts the normalizing and high-temperature tempering procedures to replace the quenching and tempering procedures (quenching and tempering refers to a composite heat treatment process of steel piece quenching and high-temperature tempering, for the low hardenability alloy carburizing steel with larger size, the hardenability and the core strength are both lower, the surface layer can not obtain martensite structure after quenching, the hardness is not high, the strengthening effect is not obvious after surface quenching), the metal crystal grains are refined, the gear hardness is improved, the process flow is simplified, and the heat treatment deformation is reduced.
5. Compared with the existing gear manufacturing method, the overall manufacturing cost is reduced by 1/5-1/4, the time is shortened by 5-6 hours, the green production requirement of energy conservation and emission reduction is met, and the method has high popularization and application values.
Drawings
FIG. 1 is a process flow diagram of one embodiment of the present invention;
FIG. 2 is a schematic view of the vehicular lightweight gear of the present invention;
FIG. 3 is a schematic view showing the shape of a fine blanking of the present invention;
FIG. 4 is a schematic diagram of the shape of the secondary fine blanking of the present invention;
FIG. 5 is a process flow diagram of another embodiment of the present invention;
FIG. 6 is a process flow diagram of another embodiment of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
Example one
As shown in fig. 2, a lightweight gear for a vehicle has a central hole diameter D =30mm, a length L =20mm, and a gear outer diameter D =74 mm.
As shown in fig. 1, the process of manufacturing the gear comprises:
and S1, roughly processing the gear raw material to obtain a gear blank with a large central hole.
Step S1 specifically includes the following substeps:
s11, machining a central small hole on the gear raw material by adopting a fine blanking process, wherein the diameter of the central small hole is 20mm, and the diameter is shown in figure 3.
And S12, expanding the small central hole into a large central hole by adopting a fine blanking process, wherein the diameter of the large central hole is slightly smaller than 30mm, and reserving machining allowance of subsequent boring holes, wherein the allowance is about 1mm, as shown in figure 4.
In the process, the traditional forging is replaced by adopting a mode of two fine blanking processes, so that the time is greatly saved.
And S2, performing heat treatment on the gear blank.
Step S2 specifically includes the following substeps:
s21, normalizing, namely heating the gear blank to 100 ℃ above the critical temperature Ac3 (note: Ac)3The critical temperature of the hypoeutectoid steel and the critical temperature Ac of different steel grades3With a different temperature value, e.g. critical temperature Ac of 20MnV3At a critical temperature Ac of 830 ℃ and 20Cr3At a critical temperature Ac of 820 ℃ and 20Mn3A critical temperature Ac of 854 ℃ and 20CrV3At 840 ℃, keeping the temperature for 1-1.5 h, completely austenitizing the gear blank, and then cooling in air to obtain a pearlite structure; and then checking whether the surface hardness is in the range of HRC 15-20, and if so, carrying out the next treatment.
And S22, the step is high-temperature tempering treatment to reduce internal stress to the maximum extent and stabilize the metal structure. Specifically, the gear blank is heated to 500 ℃, kept warm for 0.5h to obtain a tempered sorbite, and then cooled in air (for Cr-free steel) or cooled by adopting a rapid cooling mode such as water cooling or oil cooling (for Cr-containing steel).
And S3, performing semi-finishing on the gear blank to obtain a gear semi-finished product with the tooth parts.
Step S3 specifically includes the following substeps:
s31, fine machining the central big hole of the gear blank by adopting a boring mode to obtain a central hole, and in addition, fine machining can be carried out by adopting other machining modes to obtain the central hole with the aperture size and the rough surface meeting the requirements of a finished product.
S32, processing a key groove on the central hole of the gear blank, wherein the key is preferably a spline;
s33, machining the end face of the gear blank by adopting a finish turning process until the end face reaches a design size, and then chamfering the outer circle of the end face;
and S34, machining a tooth part on the outer circle of the gear blank by adopting a gear shaping or hobbing process, and chamfering the end face of the tooth part.
S4, carrying out plasma surface quenching carbonitriding treatment and sulfurization treatment on the gear semi-finished product.
Step S4 further includes the following sub-steps:
s41, performing surface quenching treatment, specifically, heating the surface of a tooth part of a gear semi-finished product to 450 ℃ by adopting a plasma beam, preserving heat for 1h, and in the process, using nitrogen as a protective gas, adding a small amount of methane into the nitrogen to serve as non-oxidation protection of surface quenching, and simultaneously realizing carbonitriding. The nitrogen addition rate was 50ml/min and the methane addition rate was 10 ml/min. And then checking whether the nitriding depth of the gear semi-finished product reaches the range of 0.5-1 mm or not and whether the quenching surface hardness is in the range of HRC 60-HRC 80 or not, and if so, carrying out next treatment.
S42, carrying out low-temperature sulfurization treatment, specifically, cooling the semi-finished gear to 170 ℃ after finishing surface quenching, and preserving heat for 2 hours to finish the sulfurization treatment, thereby obtaining a sulfurization layer with the thickness of 10-20 microns. In the step, the residual temperature after the surface quenching in the step S41 can be utilized for sulfurizing treatment, so that the energy consumption is reduced, and the time is shortened.
And S5, performing secondary finish machining on the semi-finished gear to obtain a finished gear.
Step S5 specifically includes the following substeps:
and S51, placing the gear semi-finished product into a mandrel, placing the mandrel on a honing machine, and honing the gear teeth respectively to the technical requirements.
And S52, performing bench work treatment on the semi-finished gear to obtain a finished gear. The bench work treatment comprises deburring, cleaning, oil coating and the like.
Example two
As shown in fig. 5, the difference from the first embodiment is that, in the present embodiment, the step S4 specifically includes the following sub-steps:
s41, the step is sulfurizing treatment, specifically, when the semi-finished gear product is heated by plasma beams, the surface of the tooth part of the semi-finished gear product is heated to 170 ℃, and then the temperature is kept for 2 hours to complete the sulfurizing treatment, so that a sulfurizing layer with the thickness of 10-20 microns is obtained.
S42, performing surface quenching treatment, specifically, heating the tooth part of the gear semi-finished product to 450 ℃ by adopting a plasma beam, preserving heat for 1h, and in the process, using nitrogen as a protective gas, adding a small amount of methane into the nitrogen to serve as non-oxidation protection of surface quenching, and simultaneously realizing carbonitriding. The nitrogen addition rate was 75ml/min and the methane addition rate was 15 ml/min. And then checking whether the nitriding depth of the gear semi-finished product reaches the range of 0.5-1 mm or not and whether the quenching surface hardness is in the range of HRC 60-HRC 80 or not, and if so, carrying out next treatment.
EXAMPLE III
A manufacturing process of a light gear for a vehicle is characterized in that the diameter D =35mm of a central hole of the gear, the length L =25mm of the central hole of the gear and the outer diameter D =85mm of the gear. The method comprises the following steps:
and S1, roughly processing the gear raw material to obtain a gear blank with a large central hole.
Step S1 specifically includes the following substeps:
and S11, processing a central small hole on the gear raw material by adopting a fine blanking process, wherein the diameter of the central small hole is 25 mm.
And S12, expanding the small central hole into a large central hole by adopting a fine blanking process, wherein the diameter of the large central hole is slightly smaller than 35mm, and reserving the machining allowance of the subsequent boring, and the allowance is 1 mm.
And S2, performing heat treatment on the gear blank.
Step S2 specifically includes the following substeps:
s21, normalizing, namely heating the gear blank to 120 ℃ above the critical temperature Ac3 ℃, wherein the critical temperature Ac of the low-alloy carburized steel 20MnV3Keeping the temperature at 830 ℃ for 1.5h to ensure that the gear blank is cooled in the air after being completely austenitized to obtain a pearlite structure; and then checking whether the surface hardness is in the range of HRC 15-20, and if so, carrying out the next treatment.
And S22, the step is high-temperature tempering treatment to reduce internal stress to the maximum extent and stabilize the metal structure. Specifically, the gear blank is heated to 650 ℃, and is kept warm for 1h to obtain a tempered sorbite, and then the tempered sorbite is cooled in air (for Cr-free steel) or cooled by adopting a rapid cooling mode such as water cooling or oil cooling (for Cr-containing steel).
And S3, performing semi-finishing on the gear blank to obtain a gear semi-finished product with the tooth parts.
Step S3 specifically includes the following substeps:
s31, fine machining the central big hole of the gear blank by adopting a boring mode to obtain a central hole, and in addition, fine machining can be carried out by adopting other machining modes to obtain the central hole with the aperture size and the rough surface meeting the requirements of a finished product.
S32, processing a key groove on the central hole of the gear blank, wherein the key is preferably a spline;
s33, machining the end face of the gear blank by adopting a finish turning process until the end face reaches a design size, and then chamfering the outer circle of the end face;
and S34, machining a tooth part on the outer circle of the gear blank by adopting a gear shaping or hobbing process, and chamfering the end face of the tooth part.
S4, carrying out plasma surface quenching carbonitriding treatment and sulfurization treatment on the gear semi-finished product.
Step S4 further includes the following sub-steps:
s41, performing surface quenching treatment, specifically, heating the surface of the tooth part of the gear semi-finished product to 650 ℃ by adopting a plasma beam, preserving heat for 2h, and in the process, using nitrogen as a protective gas, adding a small amount of methane into the nitrogen to serve as non-oxidation protection of surface quenching, and simultaneously realizing carbonitriding. The nitrogen addition rate was 60ml/min and the methane addition rate was 12 ml/min. And then checking whether the nitriding depth of the gear semi-finished product reaches the range of 0.5-1 mm or not and whether the quenching surface hardness is in the range of HRC 60-HRC 80 or not, and if so, carrying out next treatment.
S42, carrying out low-temperature sulfurization treatment, specifically, cooling the semi-finished gear to 190 ℃ after finishing surface quenching, and preserving heat for 4 hours to finish the sulfurization treatment, thereby obtaining a sulfurization layer with the thickness of 10-20 microns. In the step, the residual temperature after the surface quenching in the step S41 can be utilized for sulfurizing treatment, so that the energy consumption is reduced, and the time is shortened.
And S5, performing secondary finish machining on the semi-finished gear to obtain a finished gear.
Step S5 specifically includes the following substeps:
and S51, placing the gear semi-finished product into a mandrel, placing the mandrel on a honing machine, and honing the gear teeth respectively to the technical requirements.
And S52, performing bench work treatment on the semi-finished gear to obtain a finished gear. The bench work treatment comprises deburring, cleaning, oil coating and the like.
Example four
A manufacturing process of a light gear for a vehicle is characterized in that the diameter D =30mm of a central hole of the gear, the length L =20mm and the outer diameter D =80mm of the gear. The method comprises the following steps:
and S1, roughly processing the gear raw material to obtain a gear blank with a large central hole.
Step S1 specifically includes the following substeps:
and S11, processing a central small hole on the gear raw material by adopting a fine blanking process, wherein the diameter of the central small hole is 15 mm.
And S12, expanding the small central hole into a large central hole by adopting a fine blanking process, wherein the diameter of the large central hole is slightly smaller than 30mm, and reserving the machining allowance of the subsequent boring, and the allowance is about 1 mm.
And S2, performing heat treatment on the gear blank.
Step S2 specifically includes the following substeps:
s21, normalizing, namely heating the gear blank to 110 ℃ above the critical temperature Ac3 ℃, wherein the critical temperature Ac of the low-alloy carburized steel 20MnV3Keeping the temperature at 830 ℃ for 1-1.5 h to ensure that the gear blank is completely austenitized and then cooled in air to obtain a pearlite structure; and then checking whether the surface hardness is in the range of HRC 15-20, and if so, carrying out the next treatment.
And S22, the step is high-temperature tempering treatment to reduce internal stress to the maximum extent and stabilize the metal structure. Specifically, the gear blank is heated to 580 ℃, and is kept warm for 0.8h to obtain a tempered sorbite, and then the tempered sorbite is cooled in air (for Cr-free steel) or cooled by adopting a rapid cooling mode such as water cooling or oil cooling (for Cr-containing steel).
And S3, performing semi-finishing on the gear blank to obtain a gear semi-finished product with the tooth parts.
Step S3 specifically includes the following substeps:
s31, fine machining the central big hole of the gear blank by adopting a boring mode to obtain a central hole, and in addition, fine machining can be carried out by adopting other machining modes to obtain the central hole with the aperture size and the rough surface meeting the requirements of a finished product.
S32, processing a key groove on the central hole of the gear blank, wherein the key is preferably a spline;
s33, machining the end face of the gear blank by adopting a finish turning process until the end face reaches a design size, and then chamfering the outer circle of the end face;
and S34, machining a tooth part on the outer circle of the gear blank by adopting a gear shaping or hobbing process, and chamfering the end face of the tooth part.
S4, carrying out plasma surface quenching carbonitriding treatment and sulfurization treatment on the gear semi-finished product.
Step S4 further includes the following sub-steps:
s41, performing surface quenching treatment, specifically, heating the surface of a tooth part of a gear semi-finished product to 500 ℃ by adopting a plasma beam, preserving heat for 1.6h, and in the process, using nitrogen as a protective gas, adding a small amount of methane into the nitrogen to be used as non-oxidation protection of surface quenching, and simultaneously realizing carbonitriding. The nitrogen addition rate was 50ml/min and the methane addition rate was 12 ml/min. And then checking whether the nitriding depth of the gear semi-finished product reaches the range of 0.5-1 mm or not and whether the quenching surface hardness is in the range of HRC 60-HRC 80 or not, and if so, carrying out next treatment.
S42, carrying out low-temperature sulfurization treatment, specifically, cooling the semi-finished gear to 180 ℃ after surface quenching is finished, and preserving heat for 3 hours to finish the sulfurization treatment, so as to obtain a sulfurization layer with the thickness of 10-20 microns. In the step, the residual temperature after the surface quenching in the step S41 can be utilized for sulfurizing treatment, so that the energy consumption is reduced, and the time is shortened.
And S5, performing secondary finish machining on the semi-finished gear to obtain a finished gear.
Step S5 specifically includes the following substeps:
and S51, placing the gear semi-finished product into a mandrel, placing the mandrel on a honing machine, and honing the gear teeth respectively to the technical requirements.
And S52, performing bench work treatment on the semi-finished gear to obtain a finished gear. The bench work treatment comprises deburring, cleaning, oil coating and the like.
According to the invention, gear raw materials are formed by cutting low-alloy carburizing steel round bars, and the weight allowance of each gear raw material is controlled to be 0-3 g.
EXAMPLE five
A light gear for a vehicle, wherein a central hole diameter D =32mm, a length L =22mm, and a gear outer diameter D =76 mm.
As shown in fig. 6, the process of manufacturing the gear includes:
and S1, roughly processing the gear raw material to obtain a gear blank with a large central hole.
In step S1, a central large hole is machined on the gear raw material by a drilling, boring or milling process, the diameter of the central large hole is slightly smaller than 32mm, and a machining allowance of the subsequent boring is set aside, the allowance is about 0.5mm, as shown in fig. 4.
In the process, the traditional forging is replaced by a machining procedure mode, and the time is greatly saved.
And S2, performing heat treatment on the gear blank.
Step S2 specifically includes the following substeps:
s21, normalizing, namely heating the gear blank to 100 ℃ above the critical temperature Ac3 (note: Ac)3The critical temperature of the hypoeutectoid steel and the critical temperature Ac of different steel grades3With a different temperature value, e.g. critical temperature Ac of 20MnV3At a critical temperature Ac of 830 ℃ and 20Cr3At a critical temperature Ac of 820 ℃ and 20Mn3A critical temperature Ac of 854 ℃ and 20CrV3At 840 ℃, keeping the temperature for 1-1.5 h, completely austenitizing the gear blank, and then cooling in air to obtain a pearlite structure; and then checking whether the surface hardness is in the range of HRC 15-20, and if so, carrying out the next treatment.
And S22, the step is high-temperature tempering treatment to reduce internal stress to the maximum extent and stabilize the metal structure. Specifically, the gear blank is heated to 500 ℃, kept warm for 0.5h to obtain a tempered sorbite, and then cooled in air (for Cr-free steel) or cooled by adopting a rapid cooling mode such as water cooling or oil cooling (for Cr-containing steel).
And S3, performing semi-finishing on the gear blank to obtain a gear semi-finished product with the tooth parts.
Step S3 specifically includes the following substeps:
s31, fine machining the central big hole of the gear blank by adopting a boring mode to obtain a central hole, and in addition, fine machining can be carried out by adopting other machining modes to obtain the central hole with the aperture size and the rough surface meeting the requirements of a finished product.
S32, processing a key groove on the central hole of the gear blank, wherein the key is preferably a spline;
s33, machining the end face of the gear blank by adopting a finish turning process until the end face reaches a design size, and then chamfering the outer circle of the end face;
and S34, machining a tooth part on the outer circle of the gear blank by adopting a gear shaping or hobbing process, and chamfering the end face of the tooth part.
S4, carrying out plasma surface quenching carbonitriding treatment and sulfurization treatment on the gear semi-finished product.
Step S4 further includes the following sub-steps:
s41, performing surface quenching treatment, specifically, heating the surface of a tooth part of a gear semi-finished product to 450 ℃ by adopting a plasma beam, preserving heat for 1h, and in the process, using nitrogen as a protective gas, adding a small amount of methane into the nitrogen to serve as non-oxidation protection of surface quenching, and simultaneously realizing carbonitriding. The nitrogen addition rate was 65ml/min and the methane addition rate was 15 ml/min. And then checking whether the nitriding depth of the gear semi-finished product reaches the range of 0.5-1 mm or not and whether the quenching surface hardness is in the range of HRC 60-HRC 80 or not, and if so, carrying out next treatment.
S42, carrying out low-temperature sulfurization treatment, specifically, cooling the semi-finished gear to 170 ℃ after finishing surface quenching, and preserving heat for 2 hours to finish the sulfurization treatment, thereby obtaining a sulfurization layer with the thickness of 10-20 microns. In the step, the residual temperature after the surface quenching in the step S41 can be utilized for sulfurizing treatment, so that the energy consumption is reduced, and the time is shortened.
And S5, performing secondary finish machining on the semi-finished gear to obtain a finished gear.
Step S5 specifically includes the following substeps:
and S51, placing the gear semi-finished product into a mandrel, placing the mandrel on a honing machine, and honing the gear teeth respectively to the technical requirements.
And S52, performing bench work treatment on the semi-finished gear to obtain a finished gear. The bench work treatment comprises deburring, cleaning, oil coating and the like.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (8)

1. A manufacturing process of a light gear for a vehicle is characterized by comprising the following steps:
the method comprises the following steps:
s1, roughly processing the gear raw material to obtain a gear blank with a central large hole;
s2, carrying out heat treatment on the gear blank;
s3, performing semi-finishing on the gear blank to obtain a gear semi-finished product with a tooth part;
s4, carrying out plasma surface quenching carbonitriding treatment and sulfurization treatment on the gear semi-finished product;
step S4 includes the following sub-steps:
s41, heating the surface of the tooth part of the semi-finished gear to 450-650 ℃ to perform plasma surface quenching treatment, and preserving heat for 1-2 hours, wherein nitrogen is used as protective gas in the process, and methane is added into the nitrogen to complete carbonitriding treatment;
s42, cooling the gear semi-finished product to 170-190 ℃, and preserving heat for 2-4 hours to complete sulfurization treatment to obtain a sulfurization layer;
or step S4 further includes the following sub-steps:
s41, heating the surface of the tooth part of the semi-finished gear to 170-190 ℃, and preserving heat for 2-4 hours to complete sulfurization treatment to obtain a sulfurization layer;
s42, continuously heating the tooth part of the semi-finished gear to 450-650 ℃ to perform plasma surface quenching treatment, and preserving heat for 1-2 hours, wherein nitrogen is used as protective gas in the process, and methane is added into the nitrogen to complete carbonitriding treatment;
and S5, performing secondary finish machining on the semi-finished gear to obtain a finished gear.
2. A process for manufacturing a light gear for vehicles according to claim 1, wherein:
the adding speed of the nitrogen is 50-75 ml/min: the adding speed of the methane is 10-15 ml/min.
3. A process for manufacturing a light gear for vehicles according to claim 1, wherein:
step S2 further includes the following sub-steps:
s21, heating the gear blank to the critical temperature Ac3Above 100Normalizing at the temperature of 120 ℃ below zero, preserving heat for 1-1.5 hours, and cooling after the gear blank is completely austenitized to obtain a pearlite structure;
s22, heating the gear blank to 500-650 ℃ for high-temperature tempering treatment, and preserving heat for 0.5-1 h to obtain a tempered sorbite.
4. A process for manufacturing a light gear for vehicles according to claim 1, wherein:
step S1 further includes the following sub-steps:
s11, processing a central small hole on the gear raw material by adopting a fine blanking process, wherein the diameter of the central small hole is 50-70% of the design diameter;
and S12, expanding the small central hole into a large central hole by adopting a fine blanking process, wherein the diameter of the large central hole is slightly smaller than the design diameter.
5. A process for manufacturing a light gear for vehicles according to claim 1, wherein:
in step S1, a central large hole is machined on the gear raw material by a drilling, boring or milling process, and the diameter of the central large hole is slightly smaller than the design diameter.
6. A process for manufacturing a light gear for vehicles according to claim 1, wherein:
step S3 includes the following sub-steps:
s31, performing fine machining on the central large hole of the gear blank to obtain a central hole;
s32, processing a key groove on the central hole of the gear blank;
s33, finish turning the end face of the gear blank, and chamfering the outer circle of the end face;
and S34, processing a tooth part on the outer circle of the gear blank, and chamfering the end face of the tooth part.
7. A process for manufacturing a light gear for vehicles according to claim 1, wherein:
step S5 includes the following sub-steps:
s51, honing the gear semi-finished product;
and S52, performing bench work treatment on the semi-finished gear to obtain the finished gear.
8. A light gear for a vehicle, characterized in that: the process for manufacturing a lightweight gear for vehicles according to claim 1, wherein the length of the center hole of the lightweight gear for vehicles is: l is more than or equal to 10mm and less than or equal to 30mm, and the length-diameter ratio of the central hole is as follows: l/d is more than or equal to 0.1 and less than or equal to 1.
CN201910794144.1A 2019-08-27 2019-08-27 Light gear for vehicle and manufacturing process thereof Active CN110408885B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910794144.1A CN110408885B (en) 2019-08-27 2019-08-27 Light gear for vehicle and manufacturing process thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910794144.1A CN110408885B (en) 2019-08-27 2019-08-27 Light gear for vehicle and manufacturing process thereof

Publications (2)

Publication Number Publication Date
CN110408885A CN110408885A (en) 2019-11-05
CN110408885B true CN110408885B (en) 2021-06-11

Family

ID=68369167

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910794144.1A Active CN110408885B (en) 2019-08-27 2019-08-27 Light gear for vehicle and manufacturing process thereof

Country Status (1)

Country Link
CN (1) CN110408885B (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111283389B (en) * 2020-03-17 2021-10-22 无锡鹰贝精密液压有限公司 End face grinding process for wear-resisting disc of hydraulic motor
CN112276501B (en) * 2020-10-23 2021-12-14 河南蒲瑞精密机械有限公司 Machining process of gear with hard tooth surface
CN112792523A (en) * 2020-12-28 2021-05-14 江阴市万里锻件有限公司 Preparation method of high-strength gear for excavator
CN114164395B (en) * 2021-11-30 2022-09-23 清华大学 Ionic nitrogen carbon sulfur multi-element co-cementation equipment, processing system and method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN85106828A (en) * 1985-09-10 1987-03-11 张弋飞 The metal parts surface forms the method and apparatus of sulfurized layer
JPH07300662A (en) * 1994-04-28 1995-11-14 Sumitomo Metal Ind Ltd Carbo-nitriding treated steel excellent in peeling resistance of surface
CN1188813A (en) * 1997-12-26 1998-07-29 清华大学 Compound treatment method for ion nitrogen carbon co-seeping and medium temperature ion sulfuriztion
CN102091921A (en) * 2011-01-07 2011-06-15 常州市万航工矿设备有限公司 Method for manufacturing bevel gear of axle gear box for diesel locomotives
CN103736903A (en) * 2014-01-22 2014-04-23 上海交通大学 Precision forming method and device of flanged flat gears
CN104195452A (en) * 2014-08-27 2014-12-10 南京创贝高速传动机械有限公司 Drive gear and preparation method thereof
CN104589003A (en) * 2014-12-10 2015-05-06 苏州路路顺机电设备有限公司 High-carbon steel gear machining process for gear pump

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4518604B2 (en) * 1999-12-03 2010-08-04 株式会社日本テクノ Sulfur quenching treatment, sulfur carburizing treatment, and sulfur carbonitriding method
CN102560504A (en) * 2010-12-15 2012-07-11 上海汇众汽车制造有限公司 Surface treatment composite technology for prolonging service life of stamping die
CN105002507A (en) * 2015-02-06 2015-10-28 襄阳长源东谷实业股份有限公司 17CrNiMo6 material gear machining process
CN105483605A (en) * 2015-12-09 2016-04-13 常州大学 Ion nitrocarburizing and ion nitriding composite surface modification treatment method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN85106828A (en) * 1985-09-10 1987-03-11 张弋飞 The metal parts surface forms the method and apparatus of sulfurized layer
JPH07300662A (en) * 1994-04-28 1995-11-14 Sumitomo Metal Ind Ltd Carbo-nitriding treated steel excellent in peeling resistance of surface
CN1188813A (en) * 1997-12-26 1998-07-29 清华大学 Compound treatment method for ion nitrogen carbon co-seeping and medium temperature ion sulfuriztion
CN102091921A (en) * 2011-01-07 2011-06-15 常州市万航工矿设备有限公司 Method for manufacturing bevel gear of axle gear box for diesel locomotives
CN103736903A (en) * 2014-01-22 2014-04-23 上海交通大学 Precision forming method and device of flanged flat gears
CN104195452A (en) * 2014-08-27 2014-12-10 南京创贝高速传动机械有限公司 Drive gear and preparation method thereof
CN104589003A (en) * 2014-12-10 2015-05-06 苏州路路顺机电设备有限公司 High-carbon steel gear machining process for gear pump

Also Published As

Publication number Publication date
CN110408885A (en) 2019-11-05

Similar Documents

Publication Publication Date Title
CN110408885B (en) Light gear for vehicle and manufacturing process thereof
CN103286533B (en) Driving bevel gear axis for rear axle processing technology
CN102019335B (en) Cold forging processing method of hardened and tempered structural steel
CN104439994B (en) Manufacturing method for automobile transmission gear
CN102873520B (en) Process for machining marine gear
CN107283122B (en) A kind of manufacturing process of automobile hollow semiaxis
CN106363377A (en) Machining method of gear shafts
CN107120357B (en) Driving shaft bell-shaped shell structure and process treatment method thereof
CN105643218A (en) Machining method of gear parts of gearbox
CN104959794A (en) Method for machining large inner gear ring of wind turbine gear box
CN106964948A (en) A kind of processing technology of marine gear
CN103341735A (en) Hollow shaft and method for producing same
CN102803522A (en) Method for producing harmonic drive gear base material
CN110142577B (en) Machining process of input shaft of speed reducer
CN111360488A (en) Processing method of caterpillar track link for caterpillar track
CN101348055A (en) Compressional deformation strengthened flexible hollow half axle and fabrication process thereof
CN113059318A (en) Preparation method of thin-wall part
CN103302464B (en) Anti-fatigue manufacturing method of car transmission gear
CN108747240A (en) A kind of car Gearmaking Technology
CN112063823A (en) Alloy steel high-speed rail axle and production method thereof
CN107263028A (en) A kind of processing technology of Novel shaft class part machinery
US20150196980A1 (en) Method of manufacturing gear with teeth involving forging
CN106435370A (en) High-speed steel roller special for cold-rolled high-strength car plate and manufacturing method thereof
CN106425345A (en) Transmission shaft manufacturing process
KR20200134834A (en) Manufacturing method of a lightweight piston rod with improved corrosion resistance of a shock-absorber

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant