CN110158021A - A kind of carburizing equipment and method for carburizing - Google Patents

Abstract

The invention provides a carburizing equipment and a carburizing method, which relate to the technical field of carburizing. The carburizing equipment includes a housing, a heating chamber, a vacuum treatment device, an exhaust gas inlet device, and a carburizing gas inlet device. , Before vacuuming, exhaust gas can be introduced into the heating chamber through the exhaust gas inlet device, so as to avoid air infiltration into the heating chamber and affect the heating device when the workpiece is loaded into the cooling area from the outside. At the same time, the vacuum processing device is connected with the housing shell and the heating chamber, so that the entire housing housing can be vacuumed, and the heating chamber is connected with the carburizing area, so that the heating chamber can also ensure the vacuum state during vacuuming, and then can Open the heat-sealed door under vacuum and load the workpiece into the heating chamber. Compared with the prior art, the carburizing equipment provided by the present invention does not need to be provided with a vacuum-sealed door, which can simplify the workpiece loading procedure, and at the same time, no oxidation will occur in the carburizing chamber, so as to protect the heating material in the carburizing chamber.

Description

A kind of carburizing equipment and carburizing method

technical field

The invention relates to the technical field of carburizing, in particular to a carburizing equipment and a carburizing method.

Background technique

The vacuum carburizing method is a carburizing method commonly used in the prior art. For the vacuum carburizing method, it is usually necessary to configure vacuum carburizing equipment. In the prior art, the vacuum carburizing equipment, especially the equipment using oil cooling, uses a partition plate to separate the carburizing chamber from the cooling chamber, and, in order to protect The carburizing chamber needs to be equipped with two doors, the atmosphere partition (vacuum sealing door) and the thermal partition door, which greatly increases the difficulty of opening and closing the carburizing chamber. In addition, when the equipment is composed of a carburizing room and a cooling room, the loading and unloading of processed products is carried out in the cooling room. Generally, for the device composed of these two chambers, in consideration of energy saving, the carburizing chamber will be kept warm at high temperature. In this case, if the processed product is carried in and out, the carburizing chamber will be oxidized due to the oxidizing components in the atmosphere, which will affect the heating material in the carburizing chamber.

In view of this, a design and manufacture that does not need to be sealed to isolate the heating chamber and cooling area, and does not need to be equipped with a vacuum-sealed door can simplify the loading process of the workpiece, and at the same time, no oxidation will occur in the carburizing chamber to protect the carburizing of the heating materials in the carburizing chamber. equipment is particularly important.

Contents of the invention

The purpose of the present invention is to provide a carburizing equipment, which does not need to be provided with a vacuum sealing door, can simplify the workpiece loading procedure, and at the same time, oxidation does not occur in the carburizing chamber, and the heating material in the carburizing chamber is protected.

The present invention is realized by adopting the following technical solutions.

A carburizing equipment, comprising a housing shell, a heating chamber, a vacuum treatment device, an exhaust gas inlet device and a carburizing gas inlet device, the housing housing has a carburizing zone and a cooling zone connected to each other, and the heating chamber It is installed in the carburizing area, and one end of the heating chamber is provided with a heat-sealed door to isolate the inside of the heating chamber from the cooling area. The exhaust gas inlet device is connected to the heating chamber, and is used to feed exhaust gas into the heating chamber. The carburizing gas feeding device is connected with the heating chamber, and is used to feed the carburizing gas into the heating chamber. The bottom of the heating chamber is provided with a flow hole communicating with the carburizing area. Connection for evacuating the housing.

Further, a convection fan is provided at the end of the heating chamber away from the heat-sealed door, and the convection fan extends into the heating chamber to stir the gas in the heating chamber.

Furthermore, a cooling port is provided at the end of the heating chamber away from the heat-sealed door, and a cooling cover is provided on the cooling port for reducing the temperature in the heating chamber when opened.

Further, a first heat exchanger is provided outside the cooling port, and the first heat exchanger is spaced apart from the cooling cover for heat exchange with the gas flowing out of the cooling port.

Further, the heating chamber is provided with a graphite heater for heating the inner space of the heating chamber, and the graphite heater is isolated from the inner space of the heating chamber.

Further, the outer cover of the graphite heater is provided with a protection tube, and the protection tube is embedded on the inner wall of the heating chamber to isolate the graphite heater from the inner space of the heating chamber.

Further, a feeding port communicating with the cooling area is opened on the housing shell, and a feeding door is arranged on the feeding port, and the feeding door is used to open or close the feeding port.

Further, the lower side of the cooling zone is provided with an oil cooling pool for cooling the workpiece after carburizing, and the upper side of the cooling zone is provided with a gas cooling device for cooling the oil fume generated in the oil cooling pool and for cooling the workpiece after carburizing. Products that do not require oil cooling are gas cooled.

Further, the gas cooling device includes a cooling fan and a second heat exchanger, the cooling fan is connected to the inner wall of the housing shell, and the second heat exchanger is connected to the cooling fan for heat exchange with oil fume and for heat exchange with carburizing Aftercooling does not require heat exchange with the gas of the oil-cooled product.

A carburizing method is suitable for the above-mentioned carburizing equipment, and the carburizing method comprises the following steps:

Load the workpiece into the cooling zone;

Introduce exhaust gas into the heating chamber;

Vacuumize the housing;

Open the heat-sealed door and load the workpiece into the heating chamber;

Close the heat-sealed door, heat and keep warm the heating chamber, at this time, selectively pass exhaust gas into the heating chamber;

Carburizing gas is passed into the heating chamber to carburize the workpiece.

The present invention has the following beneficial effects:

The carburizing equipment provided by the present invention can pass exhaust gas into the heating chamber through the exhaust gas inlet device before vacuuming, so as to prevent the air from infiltrating into the heating chamber and affecting the heating when the workpiece is loaded into the cooling area from the outside. device. At the same time, the vacuum processing device is connected with the housing shell and the heating chamber, so that the entire housing housing can be vacuumed, and the heating chamber is connected with the carburizing area, so that the heating chamber can also ensure the vacuum state during vacuuming, and then can Open the heat-sealed door under vacuum and load the workpiece into the heating chamber. Compared with the prior art, the carburizing equipment provided by the present invention does not need to be provided with a vacuum-sealed door, which can simplify the workpiece loading procedure, and at the same time, no oxidation will occur in the carburizing chamber, so as to protect the heating material in the carburizing chamber.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is the structural representation of the carburizing equipment provided by the first embodiment of the present invention;

Fig. 2 is a schematic structural view of the heating chamber in Fig. 1;

Fig. 3 is the connection structure schematic diagram of graphite heater among Fig. 2;

Fig. 4 is a schematic diagram of the connection structure of the gas cooling device in Fig. 1;

Fig. 5 is a block diagram of the steps of the carburizing method provided by the second embodiment of the present invention.

Icons: 100-carburizing equipment; 110-housing shell; 111-carburizing zone; 113-cooling zone; 1131-oil cooling pool; 115-feeding door; 117-feeding device; 130-heating chamber; 131-heat Sealing door; 133-convection fan; 135-cooling port; 137-cooling cover; 139-first heat exchanger; 140-graphite heater; 141-protection tube; 150-vacuum treatment device; Device; 180-Carburizing gas feeding device; 190-Gas cooling device; 191-Cooling fan; 193-Second heat exchanger; 195-Smoke collecting plate.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "vertical", "horizontal", "inner" and "outer" are based on the Orientation or positional relationship, or the orientation or positional relationship that the inventive product is usually placed in use, is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, Constructed and operative in a particular orientation and therefore are not to be construed as limitations of the invention. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "connecting", "installing" and "connecting" should be understood in a broad sense, for example, it may be a fixed connection, It can also be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

As stated in the background art, the vacuum carburizing equipment in the prior art has various disadvantages. To expand, in order to protect the heating chamber, a shelter door is required. The effect of general door is to cut off the door of atmosphere and heat, what is provided with in existing vacuum carburizing equipment is these two doors of atmosphere cut off (vacuum sealed door) and heat cut off door (heat sealed door). In particular, it is difficult to open the door quickly so as not to damage the sealing material of the door for cutting off the atmosphere. Therefore, the movement time from the carburizing chamber to the oil cooling chamber is longer. However, existing vacuum carburizing equipment generally uses graphite heaters for heating. If graphite heaters are used, if there is coal accumulation on the part (electrode insulator) that passes from the carburizing chamber to the outside, when the workpiece is loaded, the external Sparks will be generated when the air enters the carburizing equipment, so the through part of the heater needs to be cleaned frequently, which is very troublesome. In addition to graphite heaters, the protective tube (SUS) on the surface of metal heaters will gradually carburize and become brittle. Therefore, durability is a difficulty, and the use temperature is lower than that of graphite heaters. And because the ceramic heater is weak to thermal shock, if there is a drastic temperature change, there is a risk of fracture, and the use temperature is lower than that of the graphite heater. The most common heating method for vacuum carburizing is radiation heating, and there is no convective air in the equipment, resulting in a slow heating rate. If a large number of processed products are accumulated, the soaking time will be very long.

The carburizing equipment provided by the present invention can combine the advantages of the vacuum carburizing method and the atmosphere carburizing method, does not need to set a vacuum sealing door, can simplify the workpiece loading procedure, and at the same time, no oxidation will occur in the carburizing chamber, and the heating in the carburizing chamber can be protected. equipment.

Some embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. In the case of no conflict, the features in the following embodiments can be combined with each other.

first embodiment

Referring to Fig. 1, the present embodiment provides a carburizing equipment 100, including a housing housing 110, a heating chamber 130, a vacuum treatment device 150, an exhaust gas inlet device 170 and a carburizing gas inlet device 180, which accommodates The casing 110 has a carburizing zone 111 and a cooling zone 113 which communicate with each other. A heating chamber 130 is arranged in the carburizing zone 111. A heat-sealed door 131 is opened at one end of the heating chamber 130 to isolate the inside of the heating chamber 130 from the cooling zone. 113. The exhaust gas inlet device 170 is connected to the heating chamber 130, and is used to feed exhaust gas into the heating chamber 130. The carburizing gas inlet device 180 is connected to the heating chamber 130, and is used to feed into the heating chamber 130. For carburizing gas, the bottom of the heating chamber 130 is provided with a flow hole communicating with the carburizing area 111 . The vacuum treatment device 150 is arranged on the housing shell 110 and connected with the flow hole for vacuuming the housing shell 110 .

The lower side of the cooling zone 113 is provided with an oil cooling pool 1131, which is used to cool the workpiece after carburizing, and the upper side of the cooling zone 113 is provided with a gas cooling device 190, which is used to cool the oil fume generated in the oil cooling pool 1131 and to prevent carburization. Carbon Post does not require oil cooled products for gas cooling. Specifically, an oil agitator is provided in the oil cooling pool 1131, and the oil agitator has a frequency conversion function, and the rotation speed can be changed through a frequency converter or the like. At high rotations, oil fluidity is improved, resulting in increased cooling rates. However, the difference between the places that are easy to cool and the places that are not easy to cool becomes large, resulting in uneven hardness. The opposite is true at low revs.

It should be noted that the oil cooling pool 1131 uses cooling oil to cool the workpiece. When the workpiece is put in, a large amount of high-temperature oil fume will be generated, and the high-temperature oil fume will float upwards to the gas cooling device 190 for cooling, and then drop back to the oil cooling pool after cooling. In 1131, the high-temperature fumes were effectively treated to avoid entering the external space.

In this embodiment, the housing 110 is a vacuum-resistant pressure vessel, and the vacuum processing device 150 has dual functions of vacuuming and exhausting, and can pump the gas in the housing 110 to a negative pressure state. The heating chamber 130 communicates with the inside of the housing 110 , so the inside of the heating chamber 130 can also be pumped to a negative pressure state. Preferably, the vacuum processing device 150 has at least a vacuum tube protruding into the heating chamber 130, which can directly vacuumize the heating chamber 130; , the accommodating shell 110 can be evacuated, and since the heating chamber 130 and the accommodating shell 110 communicate with each other, the vacuuming position is not specifically limited.

In this embodiment, the top of the heating chamber 130 is provided with an exhaust gas inlet, and the heating chamber 130 is evacuated through the exhaust gas inlet device 170 before vacuuming, which can prevent the external air from passing through when the workpiece is loaded. The hole enters the inside of the heating chamber 130 to avoid oxidation.

It should be noted that, in this embodiment, the exhaust gas is nitrogen, of course, it may also be other rare gases, which are not specifically limited here.

In this embodiment, the housing shell 110 is provided with a feeding port communicating with the cooling zone 113, and a feeding door 115 is provided on the feeding port, and the feeding door 115 is used to open or close the feeding port. Specifically, when the material feeding door 115 is closed, the sealing can be ensured, so that no gas exchange occurs at the material feeding port with the outside world.

It is worth noting that in this embodiment, the housing 110 is also provided with a feeding device 117, and the feeding device 117 can move freely outside the discharge port, in the cooling zone 113 and the heating chamber 130, and plays a role in feeding the workpiece. Sending in/out of the feeding port from the outside, and sending the workpiece into/out of the heating chamber 130 again. Preferably, the feeding device 117 is a feeding trolley, and guide rails are arranged on its traveling path, and its specific structure is consistent with that of the existing feeding trolley, which will not be described in detail here.

In the carburizing equipment 100 provided in this embodiment, the workpiece is first sent into the cooling zone 113 from the feed port during processing, and at the same time, nitrogen gas is introduced into the heating chamber 130 by using the exhaust gas inlet device 170 to avoid passing through the feed port. A large amount of air infiltrates into the carburizing chamber through the gap between the circulation hole and the heat-sealed door 131. After loading the workpiece, close the feeding door 115, and stop feeding nitrogen, and then use the vacuum processing device 150 to clean the carburizing chamber and the container. The casing 110 is subjected to vacuum treatment, so that a negative pressure is formed inside the housing casing 110, and the heat-sealed door 131 is opened in a vacuum state, and the workpiece is sent into the carburizing chamber for carburizing treatment.

Referring to FIG. 2 and FIG. 3 together, the end of the heating chamber 130 away from the heat-sealed door 131 is provided with a convection fan 133 , and the convection fan 133 extends into the heating chamber 130 for agitating the gas in the heating chamber 130 . In addition, a cooling port 135 is provided at the end of the heating chamber 130 away from the heat-sealed door 131 , and a cooling cover 137 is provided on the cooling port 135 for reducing the temperature in the heating chamber 130 when opened.

In this embodiment, a first heat exchanger 139 is provided outside the cooling port 135 , and the first heat exchanger 139 is spaced apart from the cooling cover 137 for exchanging heat with the gas flowing out of the cooling port 135 .

It should be noted that the first heat exchanger 139 is a refrigeration heat exchanger, which exchanges heat with the high-temperature gas passing through the heating chamber 130, so as to further reduce the temperature in the heating chamber 130 and shorten the slow cooling stage time. , so that the workpiece can be cooled slowly to avoid uneven temperature of the processed product.

In this embodiment, in the slow cooling stage, by opening the cooling cover 137, the gas in the furnace can exchange heat with the outside air through the cooling port 135, and at the same time, the first heat exchanger 139 is provided to further enhance the efficiency of heat exchange. The effect is to reduce the temperature in the furnace.

The heating chamber 130 is provided with a graphite heater 140 for heating the inner space of the heating chamber 130, and the graphite heater 140 is isolated from the inner space of the heating chamber 130, that is, the graphite heater 140 is set as a space to maintain sealing, and The carburizing space in the heating chamber 130 is isolated. Preferably, the graphite heater 140 is covered with a protective tube 141 , and the protective tube 141 is embedded on the inner wall of the heating chamber 130 to isolate the graphite heater 140 from the inner space of the heating chamber 130 .

It should be noted that the protection tube 141 is made of high temperature resistant material and has good thermal conductivity. The structure of protecting the heater through the protection tube 141 is consistent with the structure of the existing protection tube 141 , and will not be described in detail here.

In other preferred embodiments of the present invention, the protection method of the graphite heater 140 may also be muffle protection, specifically, for the flow space mainly composed of carburizing gas, the heater part is isolated by a plate or the like.

Referring to Fig. 4, the gas cooling device 190 includes a cooling fan 191 and a second heat exchanger 193, the cooling fan 191 is connected to the inner wall of the housing 110, and the second heat exchanger 193 is connected to the cooling fan 191 for removing the fume from the oil. heat exchange. Specifically, the second heat exchanger 193 is also a refrigeration heat exchanger, which can cool the oily fumes floating upward, so that the oily fumes can recondense into cooling oil and drop into the oil cooling pool 1131 .

In this embodiment, the cooling fan 191 includes a cooling blade, a bracket, and a cooling fan. The cooling fan is arranged on the housing 110 and has a rotating shaft penetrating into the housing 110. The cooling fan communicates with the cooling fan through the rotating shaft. Fan transmission connection, the bracket is arranged outside the rotating shaft and fixedly connected with the inner wall of the housing 110, the second heat exchanger 193 is arranged on the bracket and is located above the cooling fan blade, when the cooling fan blade is activated, the oil fume moves upward and Fully contact with the second heat exchanger 193 to realize heat exchange.

It should be noted that, in this embodiment, a smoke collecting plate 195 is also provided under the bracket. The smoke collecting plate 195 is trumpet-shaped and surrounds the cooling fan, and collects the oil fumes to the cooling fan and discharges upwards through the cooling fan to connect with the second cooling fan. The two heat exchangers 193 are in contact.

In this embodiment, the carburizing process includes a heating stage, a heat preservation stage and a carburizing stage. In the heating stage, nitrogen gas can be selectively passed into the heating chamber 130 through the exhaust gas inlet device 170, and the convection fan 133 can be started. , the nitrogen gas in the heating chamber 130 is stirred and convectively heated. Due to the convective gas, the heating process is faster than that in a vacuum state, and the temperature in the furnace can be raised rapidly. Of course, heating can also be performed directly in a vacuum state, which can save nitrogen resources. That is to say, the present embodiment provides the heating chamber 130, which can have energy-saving operation and short-time operation. In the energy-saving operation, the heating stage is heated under vacuum, and in the short-time operation, nitrogen gas is passed into the heating chamber. 130 for convective heating. At this time, the pressure in the furnace is controlled at 80kpa. And because of the thermal expansion of the heated gas, the furnace pressure will rise. In order to ensure the sealing, the pressure in the furnace must not exceed 101kpa. At this time, the pressure in the furnace can be adjusted by injecting nitrogen at intervals.

It should also be noted that in the heat preservation stage and the heating stage, there are energy-saving operation conditions and short-term operation conditions, please refer to the above process for details. In addition, a preheating stage is required before the heating stage. In the preheating stage, heating is carried out in a vacuum state. The purpose is to evaporate the moisture attached to the workpiece.

In the carburizing stage, as an option, the carburizing gas is fed into the vacuum furnace through the carburizing gas feeding device 180, specifically, the carburizing gas is acetylene. Specifically, in the case of short-term operation, the convection fan 133 is used to stir when the pressure is close to the atmospheric pressure (this is also controlled on the decompression side, such as about 80kpa); The furnace is in a vacuum state. After that, carburizing gas is introduced through the carburizing gas introducing device 180 . In the case of using acetylene gas, control the pressure to be below the pressure (200 Pa or less) for switching from the vacuum viscous flow region to the intermediate region. Even if the characteristics of gas molecular flow are used even a little, there will be gaps between the processed products, so they can come in and out freely, and the occurrence of carburizing unevenness can be reduced.

Diffusion is required after the carburizing process. The diffusion stage is the same as the heating stage, with energy-saving operation and short-term operation. Please refer to the above process for details. Both nitrogen atmosphere and vacuum atmosphere are acceptable.

Enter the slow cooling stage after the diffusion stage, use the cooling cover 137 on the heating chamber 130 to reduce the gas temperature inside the carburizing chamber, specifically, keep the cooling cover 137 open until the cooling temperature is reached. If the workpiece is directly taken out and put into the oil cooling pool 1131, the temperature of the processed product may be uneven if it is rapidly cooled, so the opening and closing operation may be repeated within a certain interval. During this period, the convection fan 133 is activated, so that the cooling time can be shortened.

After the slow cooling stage is completed, heat preservation needs to be carried out again before quenching. At this time, the convection fan 133 can also be used to shorten the time. Finally, the workpiece is taken out from the heating chamber 130 and put into the oil cooling pool 1131, and the gas cooling device 190 is started to cool the oil fume.

To sum up, the carburizing equipment 100 provided in this embodiment breaks the heating chamber by placing the heating chamber 130 in the vacuum-sealed housing 110 and vacuumizing the housing 110 as a whole. The conventional setting that 130 must be separated from the cooling zone 113 by air properties avoids additionally setting an airtight door on the heating chamber 130, reduces the difficulty of opening and closing the entrance and exit of the heating chamber 130, and improves the feeding efficiency. At the same time, the graphite heater 140 is used, and the protective tube 141 is provided outside the graphite heater 140, which can effectively protect the graphite heater 140 and improve the service life of the heating chamber 130. In addition, the gas cooling device 190 is used to cool the oily fume to prevent the oily fume from being discharged to the outside, and to carry out gas cooling for carburized products that do not require oil cooling, so as to meet different process requirements after carburizing. In addition, by providing the exhaust gas inlet device 170, a nitrogen atmosphere can be formed in the heating chamber 130, achieving an effect that ordinary vacuum carburizing furnaces cannot achieve. At the same time, in the stages of heating, heat preservation and diffusion, a vacuum atmosphere or a nitrogen atmosphere can be optionally used, which can be selected according to actual conditions and needs, so that the functions of the heating chamber 130 are more diverse and can meet various needs.

second embodiment

Referring to FIG. 5 , this embodiment provides a carburizing method, which is applicable to the carburizing equipment 100 provided in the first embodiment.

The carburizing method provided by the present embodiment comprises the following steps:

S1: Load the workpiece into the cooling zone 113.

Specifically, open the feeding door 115 on the accommodating housing 110 , use the feeding device 117 to send the workpiece into the feeding port, and stay in the cooling zone 113 .

S2: Pass exhaust gas into the heating chamber 130 .

Specifically, nitrogen gas is fed into the heating chamber 130 through the exhaust gas inlet device 170, so that the heating chamber 130 is filled with nitrogen gas, and air entering the cooling zone 113 from the feeding port is prevented from entering the heating chamber 130 through the flow holes. During actual charging, because the inside of the heating chamber 130 is high temperature, the heat-sealed door 131 is closed. Nitrogen gas was introduced into the heating chamber 130 . Because it is not completely sealed, it flows from the inside of the heating chamber 130 to the outside of the heating chamber 130 through the gaps and through holes. Gas is exhausted through the open feed gate 115 . The circulating air will certainly flow into the heating chamber 130 from the opened feeding door 115, but because the furnace is full of nitrogen, the heating chamber 130 is under positive pressure, which can reduce the inflow of air.

S3: Vacuum the accommodating casing 110 .

Specifically, the entire housing case 110 is evacuated by the vacuum processing device 150 , and the vacuum processing device 150 is turned off after the evacuation reaches a predetermined value for a certain period of time. At this time, a change in the degree of vacuum is confirmed. The purpose is to check whether the vacuum is leaking. If no deterioration of the specified vacuum degree is found within the specified time, proceed to the next step. If there is deterioration phenomenon, we give an alert and perform check.

S4: Open the heat-sealed door 131 and load the workpiece into the heating chamber 130 .

Specifically, the workpiece is sent from the cooling zone 113 to the heating chamber 130 by the feeding device 117 .

S5 : Close the heat-sealed door 131 , heat and keep warm the heating chamber 130 , and at this time, selectively pass exhaust gas into the heating chamber 130 .

Specifically, the heating of the heating chamber 130 is divided into a preheating stage and a heating stage. In the preheating stage, the heating chamber 130 is heated in a vacuum state for the purpose of evaporating moisture attached to the processed product. During the heating stage, nitrogen gas can be selectively passed into the heating chamber 130 through the exhaust gas inlet device 170, and the convection fan 133 is started to stir the nitrogen in the heating chamber 130 and carry out convective heating. , making the heating process faster than that in a vacuum state, and can rapidly raise the temperature in the furnace. Of course, heating can also be performed directly in a vacuum state, which can save nitrogen resources. That is to say, the present embodiment provides the heating chamber 130. In the heating stage, there may be energy-saving operation and short-term operation. In the energy-saving operation, the heating stage is heated under vacuum. into the heating chamber 130 for convection heating. At this time, the pressure in the furnace is controlled at 80kpa. And because of the thermal expansion of the heated gas, the furnace pressure will rise. In order to ensure the sealing, the pressure in the furnace must not exceed 101kpa. At this time, the pressure in the furnace can be adjusted by injecting nitrogen at intervals.

In the heat preservation stage, like the heating stage, there are energy-saving operation conditions and short-term operation conditions, please refer to the above process for details.

S6: Passing carburizing gas into the heating chamber 130 to carburize the workpiece.

Specifically, the carburizing process is also optional, and the carburizing gas is fed into the vacuum furnace through the carburizing gas feeding device 180, and the carburizing gas is acetylene. Specifically, in the case of short-term operation, stirring is performed by the convection fan 133 under the condition of close to atmospheric pressure (this is also controlled on the decompression side, for example, about 80kpa). In the case of energy-saving operation, after the heat preservation stage is over, the furnace is in a vacuum state. After that, carburizing gas is introduced through the carburizing gas introducing device 180 . In the case of using acetylene gas, control the pressure to be below the pressure (200 Pa or less) for switching from the vacuum viscous flow region to the intermediate region. Even if the characteristics of gas molecular flow are used even a little, there will be gaps between the processed products, so they can come in and out freely, and the occurrence of carburizing unevenness can be reduced.

Diffusion is required after the carburizing process. The diffusion stage is the same as the heating stage, with energy-saving operation and short-term operation. Please refer to the above process for details. Both nitrogen atmosphere and vacuum atmosphere are acceptable.

Enter the slow cooling stage after the diffusion stage, use the cooling cover 137 on the heating chamber 130 to reduce the gas temperature inside the carburizing chamber, specifically, keep the cooling cover 137 open until the cooling temperature is reached. If the workpiece is directly taken out and put into the oil cooling pool 1131, the temperature of the processed product may be uneven if it is rapidly cooled, so the opening and closing operation may be repeated within a certain interval. During this period, the convection fan 133 is activated, so that the cooling time can be shortened.

After the slow cooling stage is completed, heat preservation needs to be carried out again before quenching. At this time, the convection fan 133 can also be used to shorten the time. Finally, the workpiece is taken out from the heating chamber 130 and put into the oil cooling pool 1131, and the gas cooling device 190 is started to cool the oil fumes.

Specifically, after the cooling process is completed, the treated product is removed from the oil, and soot is generated again. At this time, in order to reduce the soot accumulated in the furnace, the gas cooling device 190 is continuously activated. Finally, to extract the processed product, first repressurize the furnace to atmospheric pressure (the repressurized gas generally uses nitrogen), and then take the workpiece out of the feeding port.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For example, the present invention can also be used for general vacuum heat treatment. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A carburizing equipment, characterized in that it comprises an accommodating housing, a heating chamber, a vacuum treatment device, an exhaust gas inlet device and a carburizing gas inlet device, and the accommodating housing has interconnected carburizing a carbon zone and a cooling zone, the heating chamber is arranged in the carburizing zone, a heat-sealed door is opened at one end of the heating chamber to isolate the interior of the heating chamber from the cooling zone, the evacuation The gas inlet device is connected to the heating chamber, and is used to feed exhaust gas into the heating chamber, and the carburizing gas inlet device is connected to the heating chamber, and is used to feed carburizing gas into the heating chamber. gas, the heating chamber is in communication with the carburizing zone, and the vacuum treatment device is arranged on the housing for vacuuming the housing. 2. The carburizing equipment according to claim 1, wherein a convection fan is provided at the end of the heating chamber away from the heat-sealed door, and the convection fan extends into the heating chamber for The gas in the heating chamber is agitated. 3. The carburizing equipment according to claim 2, characterized in that, the end of the heating chamber away from the heat-sealed door is also provided with a cooling port, and the cooling port is provided with a cooling cover for lowering when opened. The temperature in the heating chamber. 4. The carburizing equipment according to claim 3, characterized in that, a first heat exchanger is also provided on the outside of the cooling port, and the first heat exchanger is spaced apart from the cooling cover for contact with the cooling cover. The gas flowing out of the cooling port undergoes heat exchange. 5. The carburizing equipment according to claim 1, wherein a graphite heater for heating the inner space of the heating chamber is arranged in the heating chamber, and the graphite heater and the inside of the heating chamber Spaces are isolated from each other. 6. The carburizing equipment according to claim 5, characterized in that, the graphite heater cover is provided with a protection tube, and the protection tube is embedded on the inner wall of the heating chamber, so that the graphite heater It is isolated from the inner space of the heating chamber. 7. The carburizing equipment according to claim 1, characterized in that, the accommodating shell is provided with a feed port communicating with the cooling zone, the feed port is provided with a feed gate, and the feed gate is used for To open or close the feed port. 8. The carburizing equipment according to claim 1, characterized in that, the lower side of the cooling zone is provided with an oil cooling pool for cooling the workpiece after carburizing is completed, and the upper side of the cooling zone is provided with a gas The cooling device is used for cooling the oil fumes generated in the oil cooling pool and for gas cooling of products that do not require oil cooling after carburizing. 9. The carburizing equipment according to claim 8, wherein the gas cooling device comprises a cooling fan and a second heat exchanger, the cooling fan is connected to the inner wall of the containing housing, and the first The second heat exchanger is connected with the cooling fan, and is used for heat exchange with the oil fume and for heat exchange with gas that cools products that do not require oil cooling after carburizing. 10. A carburizing method, characterized in that it is applicable to the carburizing equipment according to any one of claims 1-9, said carburizing method comprising the following steps: Load the workpiece into the cooling zone; passing exhaust gas into the heating chamber; vacuumize the housing; opening the heat-sealed door and loading the workpiece into the heating chamber; Close the heat-sealed door, heat and keep warm the heating chamber; Carburizing gas is passed into the heating chamber to carry out carburizing treatment on the workpiece.