CN103978209A - Transmission gear manufacturing process based on powder metallurgy - Google Patents
Transmission gear manufacturing process based on powder metallurgy Download PDFInfo
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- CN103978209A CN103978209A CN201410129782.9A CN201410129782A CN103978209A CN 103978209 A CN103978209 A CN 103978209A CN 201410129782 A CN201410129782 A CN 201410129782A CN 103978209 A CN103978209 A CN 103978209A
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Abstract
The invention belongs to the technical field of gear manufacturing, and particularly relates to a transmission gear manufacturing process based on powder metallurgy. The transmission gear manufacturing process comprises the following steps of raw material preparation, formation, sintering, tooth brushing, heat treatment, cleaning, vacuum oil immersion and final inspection, wherein in the sintering process, the sintering process parameters are as follows: in the degreasing stage, the duration time is 10 minutes, and the sintering furnace temperature is 645 to 655 DEG C; in the preheating stage, the duration time is 20 minutes, the sintering furnace temperature in the first 10 minutes is 745 to 755 DEG C, and the sintering furnace temperature in the last 10 minutes is 845 to 855 DEG C; in the heat insulation stage, the duration time is 30 minutes, and the sintering furnace temperature is 1115 to 1125 DEG C; in the uniform temperature stage, the duration time is 10 minutes, and the sintering furnace temperature is 995 to 1005 DEG C. The performance and the quality of a transmission gear manufactured by the process are good, so the start and stop service life and the work duration are obviously prolonged.
Description
Technical field
The invention belongs to gear manufacture technology field, refer in particular to a kind of travelling gear manufacturing process based on powder metallurgy.
Background technology
Powder metallurgy is a kind of comparatively ripe technique, and it is also comparatively common for gear forming; In prior art, properties of product and the quality of the travelling gear that powder metallurgy obtains are general, and its start and stop life-span, 50,000 left and right, is used duration generally about 200 hours in the grinding machine of angle.
Summary of the invention
The object of this invention is to provide one easy to process, make performance and the quality better of travelling gear, the safe and reliable travelling gear manufacturing process based on powder metallurgy.
The object of the present invention is achieved like this:
A travelling gear manufacturing process based on powder metallurgy, comprises the following steps:
(1) raw material preparation, evenly mixes stand-by with auxiliary material by proportioning by powder metallurgy iron based powders;
(2) moulding, sends into the quantitative raw material powder mixing in press the green compact of once die stamping forming travelling gear;
(3) sintering, puts the raw embryo of product on mullite plate, and sends into sintering 70min in sintering furnace, continues to pass into appropriate nitrogen and hydrogen in sintering furnace, and wherein, sintering process parameter is as follows:
The degreasing stage, duration 10min, sintering furnace temperature is 645-655 DEG C;
Warm-up phase, duration 20min, the sintering furnace temperature of front 10min is 745-755 DEG C, the sintering furnace temperature of rear 10min is 845-855 DEG C;
Holding stage, duration 30min, sintering furnace temperature is 1115-1125 DEG C;
All thermophases, duration 10min, sintering furnace temperature is 995-1005 DEG C;
(4) brush teeth, adopts gear-brushing machine to carry out brush teeth to half-finished travelling gear;
(5) heat treatment, the operation that half-finished travelling gear is heat-treated is as follows:
1. carburizing, adopts multipurpose furnace to carry out Carburization Treatment to half-finished travelling gear;
2. quench, half-finished travelling gear is quenched in oil-quenching tank, control 110-130 DEG C of oil temperatures in oil-quenching tank, and fluid in stirring at low speed oil-quenching tank, the cool time is 30 minutes;
3. drain, the half-finished travelling gear after quenching is carried out in oil-quenching tank, drain 40 minutes time;
4. clean, use cleaning machine to remove the unnecessary fluid on half-finished travelling gear surface;
5. tempering, by the half-finished travelling gear after cleaning, as for carrying out tempering in tempering furnace, temperature is controlled at 160-180 DEG C, and the time is controlled at 120min;
6. examine eventually hardness, at least 3 points of the inspection flank of tooth, whether checking travelling gear case hardness meets standard;
7. metal lographic examination, takes off metallographic tooth piece or packs inherent quality problem to be checked with a batch waste product;
(6) clean the surface of clean half-finished travelling gear and backlash;
(7) vacuum oil immersion, by the oil immersion in the container of vacuum of half-finished travelling gear, obtains the travelling gear of finished product;
(8) final acceptance inspection, the parameters of inspection finished product travelling gear, can pack and put in storage after qualified.
Preferably, in the heat treatment of described step (5), control operation and be 2. quenched to the 5. stand-by period≤180min of tempering of operation.
Preferably, after described step (2), step (4), all need the surface with the clean half-finished travelling gear of air gun.
Preferably, the heat treated operation of described step (5) 1. has four sub-steps in the process of carburizing, and it is respectively
First samming step:, control 850-870 DEG C of furnace temperature, time 20min;
Ooze by force step: control 850-870 DEG C of furnace temperature, time 70min, CP0.7;
Cooling step: control furnace temperature and be progressively reduced within the scope of 820-840 DEG C, time 15min, CP0.6;
Secondary samming step: control 820-840 DEG C of furnace temperature, time 15min, CP0.6;
In four sub-steps, remain and pass into ammonia 2.5-3.5Nl/min; Methyl alcohol 45-55ml/min; At second and third, in four sub-steps, remain and pass into propane 5Nl/min; Balance air 5Nl/min.
Preferably, between described step (5) and step (6), be provided with following three sub-steps,
Step (5.1) inner bore grinding, grinds and controls endoporus error to half-finished travelling gear endoporus;
Step (5.2) is by end face, and for an end face of half-finished travelling gear, grinding abrasive disk is removed part surplus, in order to revise the error of the semi-finished product travelling gear that heat treatment causes;
Step (5.3) vibrations are ground, and semi-finished product driving cog is put into oscillating mill, add grind stone, vibrate 20-40 minutes;
In described step (5.1) and step (5.2), half-finished travelling gear adds man-hour, all adopts air gun to blow clean, and puts on case body special and go up antirust oil after completion of processing.
The present invention compared to existing technology outstanding and useful technique effect is:
Adopt performance and the quality better of the prepared travelling gear of technique of the present invention, it obviously got a promotion in start and stop life-span and work duration.
Brief description of the drawings
Fig. 1 is process chart of the present invention.
Detailed description of the invention
Below in conjunction with specific embodiment, further illustrate the present invention, should understand these embodiment only for the present invention is described.
As shown in Figure 1, embodiment 1: a kind of travelling gear manufacturing process based on powder metallurgy, comprises the following steps:
(1) raw material preparation, evenly mixes stand-by with auxiliary material by proportioning by powder metallurgy iron based powders;
(2) moulding, sends into the quantitative raw material powder mixing in press the green compact of once die stamping forming travelling gear;
(3) sintering, puts the raw embryo of product on mullite plate, and sends into sintering 70min in sintering furnace, continues to pass into appropriate nitrogen and hydrogen in sintering furnace, and wherein, sintering process parameter is as follows:
The degreasing stage, duration 10min, sintering furnace temperature is 645-655 DEG C;
Warm-up phase, duration 20min, the sintering furnace temperature of front 10min is 745-755 DEG C, the sintering furnace temperature of rear 10min is 845-855 DEG C;
Holding stage, duration 30min, sintering furnace temperature is 1115-1125 DEG C;
All thermophases, duration 10min, sintering furnace temperature is 995-1005 DEG C;
(4) brush teeth, adopts gear-brushing machine to carry out brush teeth to half-finished travelling gear;
(5) heat treatment, the operation that half-finished travelling gear is heat-treated is as follows:
1. carburizing, adopts multipurpose furnace to carry out Carburization Treatment to half-finished travelling gear;
2. quench, half-finished travelling gear is quenched in oil-quenching tank, control 110-130 DEG C of oil temperatures in oil-quenching tank, and fluid in stirring at low speed oil-quenching tank, the cool time is 30 minutes;
3. drain, the half-finished travelling gear after quenching is carried out in oil-quenching tank, drain 40 minutes time;
4. clean, use cleaning machine to remove the unnecessary fluid on half-finished travelling gear surface;
5. tempering, by the half-finished travelling gear after cleaning, as for carrying out tempering in tempering furnace, temperature is controlled at 160-180 DEG C, and the time is controlled at 120min;
6. examine eventually hardness, at least 3 points of the inspection flank of tooth, whether checking travelling gear case hardness meets standard;
7. metal lographic examination, takes off metallographic tooth piece or packs inherent quality problem to be checked with a batch waste product;
(6) clean the surface of clean half-finished travelling gear and backlash;
(7) vacuum oil immersion, by the oil immersion in the container of vacuum of half-finished travelling gear, obtains the travelling gear of finished product;
(8) final acceptance inspection, the parameters of inspection finished product travelling gear, can pack and put in storage after qualified.
Preferably, in the heat treatment of described step (5), control operation and be 2. quenched to the 5. stand-by period≤180min of tempering of operation.
Preferably, after described step (2), step (4), all need the surface with the clean half-finished travelling gear of air gun.
Preferably, the heat treated operation of described step (5) 1. has four sub-steps in the process of carburizing, and it is respectively
First samming step:, control 850-870 DEG C of furnace temperature, time 20min;
Ooze by force step: control 850-870 DEG C of furnace temperature, time 70min, CP0.7;
Cooling step: control furnace temperature and be progressively reduced within the scope of 820-840 DEG C, time 15min, CP0.6;
Secondary samming step: control 820-840 DEG C of furnace temperature, time 15min, CP0.6;
In four sub-steps, remain and pass into ammonia 2.5-3.5Nl/min; Methyl alcohol 45-55ml/min; At second and third, in four sub-steps, remain and pass into propane 5Nl/min; Balance air 5Nl/min.
Preferably, between described step (5) and step (6), be provided with following three sub-steps,
Step (5.1) inner bore grinding, grinds and controls endoporus error to half-finished travelling gear endoporus;
Step (5.2) is by end face, and for an end face of half-finished travelling gear, grinding abrasive disk is removed part surplus, in order to revise the error of the semi-finished product travelling gear that heat treatment causes;
Step (5.3) vibrations are ground, and semi-finished product driving cog is put into oscillating mill, add grind stone, vibrate 20-40 minutes;
In described step (5.1) and step (5.2), half-finished travelling gear adds man-hour, all adopts air gun to blow clean, and puts on case body special and go up antirust oil after completion of processing.
The gear that adopts this technique and prior art to manufacture is respectively compared, and product test data of experiment is as shown in the table:
| ? | The travelling gear that this technique is made | The travelling gear that existing technique is made |
| The start and stop life-span | More than 70,000 times | 50,000 left and right |
| Load sample (while being loaded into 1.2 times) | More than 300 hours | About 200 hours |
| The real sample of beating | More than 250 hours | About 200 hours |
Table 1
Above-described embodiment is only preferred embodiment of the present invention, not limits the scope of the invention according to this, therefore: all equivalences of doing according to structure of the present invention, shape, principle change, within all should being covered by protection scope of the present invention.
Claims (5)
1. the travelling gear manufacturing process based on powder metallurgy, is characterized in that, comprises the following steps:
(1) raw material preparation, evenly mixes stand-by with auxiliary material by proportioning by powder metallurgy iron based powders;
(2) moulding, sends into the quantitative raw material powder mixing in press the green compact of once die stamping forming travelling gear;
(3) sintering, puts the raw embryo of product on mullite plate, and sends into sintering 70min in sintering furnace, continues to pass into appropriate nitrogen and hydrogen in sintering furnace, and wherein, sintering process parameter is as follows:
The degreasing stage, duration 10min, sintering furnace temperature is 645-655 DEG C;
Warm-up phase, duration 20min, the sintering furnace temperature of front 10min is 745-755 DEG C, the sintering furnace temperature of rear 10min is 845-855 DEG C;
Holding stage, duration 30min, sintering furnace temperature is 1115-1125 DEG C;
All thermophases, duration 10min, sintering furnace temperature is 995-1005 DEG C;
(4) brush teeth, adopts gear-brushing machine to carry out brush teeth to half-finished travelling gear;
(5) heat treatment, the operation that half-finished travelling gear is heat-treated is as follows:
1. carburizing, adopts multipurpose furnace to carry out Carburization Treatment to half-finished travelling gear;
2. quench, half-finished travelling gear is quenched in oil-quenching tank, control 110-130 DEG C of oil temperatures in oil-quenching tank, and fluid in stirring at low speed oil-quenching tank, the cool time is 30 minutes;
3. drain, the half-finished travelling gear after quenching is carried out in oil-quenching tank, drain 40 minutes time;
4. clean, use cleaning machine to remove the unnecessary fluid on half-finished travelling gear surface;
5. tempering, by the half-finished travelling gear after cleaning, as for carrying out tempering in tempering furnace, temperature is controlled at 160-180 DEG C, and the time is controlled at 120min;
6. examine eventually hardness, at least 3 points of the inspection flank of tooth, whether checking travelling gear case hardness meets standard;
7. metal lographic examination, takes off metallographic tooth piece or packs inherent quality problem to be checked with a batch waste product;
(6) clean the surface of clean half-finished travelling gear and backlash;
(7) vacuum oil immersion, by the oil immersion in the container of vacuum of half-finished travelling gear, obtains the travelling gear of finished product;
(8) final acceptance inspection, the parameters of inspection finished product travelling gear, can pack and put in storage after qualified.
2. a kind of travelling gear manufacturing process based on powder metallurgy according to claim 1, is characterized in that, in the heat treatment of described step (5), controls operation and is 2. quenched to the 5. stand-by period≤180min of tempering of operation.
3. a kind of travelling gear manufacturing process based on powder metallurgy according to claim 1, is characterized in that, after described step (2), step (4), all needs the surface with the clean half-finished travelling gear of air gun.
4. a kind of travelling gear manufacturing process based on powder metallurgy according to claim 1, is characterized in that, the heat treated operation of described step (5) 1. has four sub-steps in the process of carburizing, and it is respectively
First samming step:, control 850-870 DEG C of furnace temperature, time 20min;
Ooze by force step: control 850-870 DEG C of furnace temperature, time 70min, CP0.7;
Cooling step: control furnace temperature and be progressively reduced within the scope of 820-840 DEG C, time 15min, CP0.6;
Secondary samming step: control 820-840 DEG C of furnace temperature, time 15min, CP0.6;
In four sub-steps, remain and pass into ammonia 2.5-3.5Nl/min; Methyl alcohol 45-55ml/min; At second and third, in four sub-steps, remain and pass into propane 5Nl/min; Balance air 5Nl/min.
5. a kind of travelling gear manufacturing process based on powder metallurgy according to claim 1, is characterized in that, between described step (5) and step (6), is provided with following three sub-steps,
Step (5.1) inner bore grinding, grinds and controls endoporus error to half-finished travelling gear endoporus;
Step (5.2) is by end face, and for an end face of half-finished travelling gear, grinding abrasive disk is removed part surplus, in order to revise the error of the semi-finished product travelling gear that heat treatment causes;
Step (5.3) vibrations are ground, and semi-finished product driving cog is put into oscillating mill, add grind stone, vibrate 20-40 minutes;
In described step (5.1) and step (5.2), half-finished travelling gear adds man-hour, all adopts air gun to blow clean, and puts on case body special and go up antirust oil after completion of processing.
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| CN201410129782.9A CN103978209B (en) | 2014-04-02 | 2014-04-02 | Transmission gear manufacturing process based on powder metallurgy |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107366735A (en) * | 2017-08-04 | 2017-11-21 | 扬州海昌新材股份有限公司 | A kind of helical gear and preparation method thereof |
| CN110055543A (en) * | 2019-06-05 | 2019-07-26 | 安吉长虹制链有限公司 | A kind of chain production technology |
| CN112157266A (en) * | 2020-09-30 | 2021-01-01 | 南通冠达粉末冶金有限公司 | Gear powder metallurgy sintering treatment process |
| CN113483076A (en) * | 2021-07-12 | 2021-10-08 | 扬州聚能金属制品科技有限公司 | One-time formed porous eccentric step spiral gear and machining process |
| CN114309822A (en) * | 2022-01-08 | 2022-04-12 | 浙江新昌汇盟机械有限公司 | Manufacturing method of arc bevel gear |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003013111A (en) * | 2001-07-05 | 2003-01-15 | Aisin Seiki Co Ltd | Method of manufacturing toothed gear |
| CN101474674A (en) * | 2009-01-16 | 2009-07-08 | 扬州保来得科技实业有限公司 | Powder metallurgy production method of internal helical gear |
| CN101671767A (en) * | 2009-10-16 | 2010-03-17 | 陆泽平 | Clutch gear quenching process |
| CN102000825A (en) * | 2009-09-02 | 2011-04-06 | 东睦新材料集团股份有限公司 | Method for manufacturing driving gear of motorcycle clutch |
| CN102672185A (en) * | 2012-06-07 | 2012-09-19 | 太仓市锦立得粉末冶金有限公司 | Process for manufacturing high-precision gear ring from powder metallurgy |
| CN102672183A (en) * | 2012-05-11 | 2012-09-19 | 马鞍山市华东粉末冶金厂 | Method for producing bevel gear with ratchet on end face through powder metallurgy warm forming |
-
2014
- 2014-04-02 CN CN201410129782.9A patent/CN103978209B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003013111A (en) * | 2001-07-05 | 2003-01-15 | Aisin Seiki Co Ltd | Method of manufacturing toothed gear |
| CN101474674A (en) * | 2009-01-16 | 2009-07-08 | 扬州保来得科技实业有限公司 | Powder metallurgy production method of internal helical gear |
| CN102000825A (en) * | 2009-09-02 | 2011-04-06 | 东睦新材料集团股份有限公司 | Method for manufacturing driving gear of motorcycle clutch |
| CN101671767A (en) * | 2009-10-16 | 2010-03-17 | 陆泽平 | Clutch gear quenching process |
| CN102672183A (en) * | 2012-05-11 | 2012-09-19 | 马鞍山市华东粉末冶金厂 | Method for producing bevel gear with ratchet on end face through powder metallurgy warm forming |
| CN102672185A (en) * | 2012-06-07 | 2012-09-19 | 太仓市锦立得粉末冶金有限公司 | Process for manufacturing high-precision gear ring from powder metallurgy |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107366735A (en) * | 2017-08-04 | 2017-11-21 | 扬州海昌新材股份有限公司 | A kind of helical gear and preparation method thereof |
| CN110055543A (en) * | 2019-06-05 | 2019-07-26 | 安吉长虹制链有限公司 | A kind of chain production technology |
| CN110055543B (en) * | 2019-06-05 | 2021-08-06 | 浙江省浦江三联链条有限公司 | Chain production process |
| CN112157266A (en) * | 2020-09-30 | 2021-01-01 | 南通冠达粉末冶金有限公司 | Gear powder metallurgy sintering treatment process |
| CN113483076A (en) * | 2021-07-12 | 2021-10-08 | 扬州聚能金属制品科技有限公司 | One-time formed porous eccentric step spiral gear and machining process |
| CN113483076B (en) * | 2021-07-12 | 2022-11-25 | 扬州聚能金属制品科技有限公司 | One-time formed porous eccentric step spiral gear and machining process |
| CN114309822A (en) * | 2022-01-08 | 2022-04-12 | 浙江新昌汇盟机械有限公司 | Manufacturing method of arc bevel gear |
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| CN103978209B (en) | 2017-05-03 |
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Denomination of invention: Transmission gear manufacturing process based on powder metallurgy Effective date of registration: 20170713 Granted publication date: 20170503 Pledgee: China Merchants Bank, Limited by Share Ltd, Taizhou, Huangyan branch Pledgor: Zhejiang Fore Machinery & Electronic Co., Ltd. Registration number: 2017330000066 |
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Address after: Taizhou City, Zhejiang province 318025 town Huangyan District Court Gao Yang Cun Patentee after: Zhejiang Feng Li intelligent Polytron Technologies Inc Address before: Taizhou City, Zhejiang province 318025 town Huangyan District Court Gao Yang Cun Patentee before: Zhejiang Fore Machinery & Electronic Co., Ltd. |
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Date of cancellation: 20180521 Granted publication date: 20170503 Pledgee: China Merchants Bank, Limited by Share Ltd, Taizhou, Huangyan branch Pledgor: Zhejiang Fore Machinery & Electronic Co., Ltd. Registration number: 2017330000066 |
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