JPH0741932A - Carburizing heat treatment controller - Google Patents

Abstract

(57) [Summary] [Purpose] To enable proper carburization and to prevent the growth and protrusion of Fe ₃ C to prevent the formation of brittle and unhealthy structures. In the carburizing heat treatment apparatus 1, a crater 2 for supplying a C _m H _n- based fuel, oxygen and carbon dioxide to bring a combustion flame of the C _m H _n- based fuel into contact with the surface of a material W to be treated, and the crater 2
Gas sensor 3 for detecting the amount of carbon monoxide and carbon dioxide in the combustion flame supplied from the above, temperature sensor 4 for detecting the temperature of the carburized surface of the workpiece W, and the gas sensor 3
And the temperature sensor 4 C _m H _n based fuel in accordance with the carburizing condition based on the equilibrium carbon concentration is the ratio of the detected amount of carbon monoxide and carbon dioxide amount, control for controlling the supply of oxygen and carbon dioxide The controller 5 outputs a signal, and the electromagnetic flow control valve 6 controls the supply amount of C _m H _n fuel, oxygen and carbon dioxide based on the control signal from the controller 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention enables optimum carburizing heat treatment by controlling the equilibrium carbon concentration, which is the ratio of the amount of carbon monoxide to the amount of carbon dioxide in the combustion flame of C _m H _n fuel. The present invention relates to a carburizing heat treatment control device.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional carburizing heat treatment control apparatus supplies C _m H _n fuel and oxygen at an equivalence ratio or more to a crater H and burns them to generate combustion flame. It was made to come into contact with the surface of W and heat-carburize.

[0003]

In the conventional carburizing heat treatment control device, the equilibrium carbon concentration, which is the ratio of the amount of carbon monoxide to the amount of carbon dioxide in the combustion flame supplied from the crater, is not controlled. In some cases, Fe ₃ C grows and breaks, resulting in a very brittle and unhealthy structure.

Therefore, the inventors of the present invention determined the equilibrium carbon concentration, which is the ratio of the amount of carbon monoxide and the amount of carbon dioxide in the combustion flame of C _m H _n fuel, and carburized the carburizing temperature and time at that time. Focusing on the technical idea of the present invention that the equilibrium carbon concentration is controlled according to the conditions, and as a result of further research and development, appropriate carburization is made possible and growth of Fe ₃ C is prevented. The present invention has been achieved to achieve the purpose of preventing the generation of brittle and unhealthy tissues.

[0005]

In the carburization heat treatment control apparatus of the present invention, a C _m H _n- based fuel, oxygen and carbon dioxide are supplied, and a combustion flame of the C _m H _n- based fuel is brought into contact with the surface of the material to be treated. A crater, and a sensor for detecting the amount of carbon monoxide and carbon dioxide of the combustion flame supplied from the crater,
Based on the equilibrium carbon concentration, which is the ratio of the amount of carbon monoxide and the amount of carbon dioxide detected by the sensor, C _m H
A controller that outputs a control signal for controlling the supply amounts of _n- type fuel, oxygen, and carbon dioxide, and controls the supply amounts of C _m H _n- type fuel, oxygen, and carbon dioxide based on the control signal from the controller. And a flow rate control device. The oxygen utilized in combustion of C _m H _n based fuel can be gas course use containing oxygen as air.

[0006]

In the carburization heat treatment control device of the present invention having the above-mentioned structure, the amount of carbon monoxide and carbon dioxide of the combustion flame is detected by the sensor, and the controller determines the ratio of the amount of carbon monoxide and carbon dioxide. that C _m H _n based fuel in accordance with the temperature condition based on the equilibrium carbon concentration, outputs a control signal for controlling the supply amount of oxygen and carbon dioxide, C _m H _n based on the basis of the control signal by the flow control device fuel,
It controls the supply of oxygen and carbon dioxide.

[0007]

According to the carburizing heat treatment control apparatus of the present invention having the above-mentioned operation, the C _m H _n system is determined according to the carburizing conditions based on the equilibrium carbon concentration determined by the ratio of the amounts of carbon monoxide and carbon dioxide detected in the combustion flame. It controls the supply of fuel, oxygen, and carbon dioxide, enabling proper carburization and Fe
_It has the effect of preventing the growth and protrusion of ₃ C and preventing the formation of brittle and unhealthy tissue.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) As shown in FIGS. 1 to 3, the carburization heat treatment control apparatus of the first embodiment is such that a C _m H _n system fuel, oxygen and carbon dioxide are supplied to the carburization heat treatment apparatus 1 as C A crater 2 for bringing a combustion flame of _m H _n- based fuel into contact with the surface of the material W to be treated, a gas sensor 3 for detecting the amount of carbon monoxide and carbon dioxide in the combustion flame supplied from the crater 2, The temperature sensor 4 for detecting the temperature of the carburized surface of the material W, and the C according to the carburizing condition based on the equilibrium carbon concentration which is the ratio of the carbon monoxide amount and the carbon dioxide amount detected by the gas sensor 3 and the temperature sensor 4. _m H _n based fuel, and a controller 5 for outputting a control signal for controlling the supply amount of oxygen and carbon dioxide, C _m H _n based fuel based on the control signal from the controller 5, the supply of oxygen and carbon dioxide Control quantity An electromagnetic flow control valve 6 for.

As shown in FIG. 1, the carburizing heat treatment apparatus 1 has a constant distance with respect to a surface WS to be processed of a material W to be processed which is controlled to move in a furnace (not shown) by an apparatus 1S controlled by a sequencer. The crater 2 is arranged at a distant portion, and the introduction duct 11 arranged in the crater 2 opens the supply passage 12 and acetylene cylinder 13 which is an example of C _m H _n system fuel, and oxygen cylinder. 14, carbon dioxide cylinder 15
Have been contacted.

The crater 2 is composed of a hollow member, is fixed to the tip of the introduction duct 11, and is arranged so as to face the surface WS to be processed of the material W to be processed.

The gas sensor 3 is composed of a gas analyzer. The combustion flame supplied from the crater 2 is taken into the thin tube 31 for gas analysis, and the amount of carbon monoxide and the amount of carbon dioxide are obtained, and the amount of carbon monoxide and the amount of carbon dioxide are obtained. It is configured so that the equilibrium carbon concentration, which is the ratio to the amount, can be obtained and output to the controller 5.

Also, an acetylene cylinder 13 and an oxygen cylinder 1
4 and the first to third flow rate sensors 33, 34 and 35 arranged in the passages connected to the carbon dioxide cylinder 15, the acetylene gas, the oxygen from the acetylene cylinder 13, the oxygen cylinder 14 and the carbon dioxide cylinder 15, respectively. The configuration is such that each supply flow rate of carbon dioxide can be detected and output to the controller 5.

The temperature sensor 4 is a surface W to be processed of the material W to be processed.
It consists of a radiation thermometer that is placed away from S,
The temperature of the surface WS to be processed is detected and output to the controller 5.

The controller 5 is composed of a personal computer, and according to the carburizing temperature, the carburizing time and other carburizing conditions set by key input according to the flow shown in FIG. The optimum equilibrium carbon concentration is calculated based on information such as the current supply flow rates of acetylene gas, oxygen and carbon dioxide input from the first to third flow rate sensors 33 to 35, and the temperature input from the thermometer 4. The supply amounts of acetylene gas, oxygen, and carbon dioxide are calculated from the difference between the equilibrium carbon concentration and the control signals are output via I / O.

The electromagnetic flow control valve 6 is the acetylene cylinder 1
The first solenoid valve 63 disposed in the passage communicating with the third cylinder, the second solenoid valve 64 disposed in the passage communicating with the oxygen cylinder 14, and the second solenoid valve 64 disposed in the passage communicating with the carbon dioxide cylinder 15. And a third solenoid valve 65, each of which has a controller 5
Of the acetylene gas, oxygen, and carbon dioxide supplied to the introduction duct 11 connected to the crater 2 based on the input control signal.

The carburizing heat treatment control apparatus of the first embodiment having the above-mentioned structure is composed of an acetylene cylinder 13, an oxygen cylinder 14,
Depending on the amounts of acetylene gas, oxygen, and carbon dioxide supplied from the carbon dioxide cylinder 15 to the introduction duct 11, the crater 2 of the carburizing treatment device 1 treats the combustion flame of acetylene with the material W to be treated.
The carburizing treatment is carried out by contacting the surface WS to be treated. The combustion flame of acetylene at this time is sampled by the gas sensor 3 for gas analysis, and the actual equilibrium which is the ratio of the carbon monoxide amount and the carbon dioxide amount. Calculate the carbon concentration.

The temperature sensor 4 detects the temperature of the surface WS to be processed of the material W to be processed and outputs a signal, and the first to third flow rate sensors 33 to 35 are used for the acetylene cylinder 1.
3, oxygen cylinder 14, carbon dioxide cylinder 15 to crater 2
It detects the flow rate of acetylene gas, oxygen, and carbon dioxide currently being supplied to and outputs a signal.

The controller 5 has a set carburizing temperature,
A control signal is output by considering the current flow rates of acetylene gas, oxygen, and carbon dioxide from the difference between the target equilibrium carbon concentration determined according to carburizing conditions such as carburizing time and the detected current equilibrium carbon concentration. It is a thing.

The solenoid valves 63, 64, 65 are the controller 5
The optimum supply amount of acetylene gas, oxygen, and carbon dioxide to be supplied to the crater 2 in accordance with the control signal from is controlled to achieve the target equilibrium carbon concentration according to the temperature condition.

In the carburizing heat treatment control apparatus of the first embodiment having the above-mentioned operation, the acetylene solenoid valves 63 to 65 use the acetylene valves 63 to 65 based on the difference between the actual equilibrium carbon concentration detected by the gas sensor 3 and the target equilibrium carbon concentration determined by the carburizing conditions. Since the supply amounts of gas, oxygen and carbon dioxide are controlled, it is possible to achieve the optimum carburizing treatment at the ideal target equilibrium carbon concentration corresponding to the set carburizing conditions, and to obtain a uniform martensite single-phase structure. , Fe ₃ C are prevented from growing and breaking out, and the formation of brittle and unhealthy tissue is effectively prevented.

Further, the carburizing heat treatment control apparatus of the first embodiment has the object to be treated W even if the equilibrium carbon concentration CP is 0.8.
Since the optimum supply amount of carbon dioxide changes in accordance with the change in the temperature of the surface WS to be processed, as shown in FIG. 3, the optimum amount of carbon dioxide is changed in accordance with the temperature of the surface WS to be processed of the material W detected by the temperature sensor 4. Since the supply amount of carbon dioxide is controlled by the solenoid valve 65, there is an effect that an optimum flame carburizing process can be performed with an optimum equilibrium carbon concentration. That is, the mixing ratio of acetylene gas and oxygen is 0.9 (C ₂ H ₂ : O ₂ = 1: 2.
25), CO in the combustion flame was 60% and H ₂ was 23.
5%, H 15%, acetylene (C ₂ H ₂ ), C ₂ H,
C _m (m = 1, 2, 3) and others are 1.5%, and FIG.
Shows the relationship between the temperature and the amount of carbon dioxide when CO is 60%.

Further, the carburizing heat treatment control apparatus of the first embodiment is an apparatus 1 controlled by a personal computer and a sequencer which constitute a controller 3 as shown in FIGS.
Since the material S to be processed is controlled to be taken in and out of the carburizing treatment apparatus 1, the material W to be processed can be automatically and continuously carburized.

(Second Embodiment) In the carburizing heat treatment control device of the second embodiment, the gas sensor 3 of the first embodiment device is omitted,
As shown in FIG. 4, based on only the supply amounts of acetylene gas, oxygen, and carbon dioxide detected by the first to third flow rate sensors 33 to 35 and the temperature of the workpiece W detected by the temperature sensor 4, The relations between the various target equilibrium carbon concentrations obtained experimentally and the respective gas amounts and temperatures are mapped and stored in the ROM of the personal computer, and the actual equilibrium carbon concentration is utilized by using this mapped data. Is indirectly obtained and controlled based on it, and the same operational effects as those of the first embodiment are obtained, and the gas sensor can be omitted. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted.

The embodiments described above are merely examples for the purpose of explanation, and the present invention is not limited to them, and those skilled in the art will recognize from the claims, the detailed description of the invention and the description of the drawings. Modifications and additions can be made without departing from the technical idea of the present invention.

In the above-mentioned first embodiment, an example of obtaining the equilibrium carbon concentration by the gas sensor 3 has been described.
The present invention is not limited to this, and it is also possible to calculate the ratio of both in the controller from the carbon monoxide amount and the carbon dioxide amount obtained by the gas sensor 3 to obtain the equilibrium carbon concentration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment device of the present invention.

FIG. 2 is a chart showing a control flow of the first embodiment device.

FIG. 3 is a diagram showing the relationship between the temperature of the surface to be treated and the amount of carbon dioxide when the equilibrium carbon concentration is 0.8.

FIG. 4 is a block diagram showing a second embodiment device of the present invention.

FIG. 5 is a block diagram showing a conventional device.

[Explanation of symbols]

 1 Carburizing Treatment Device 2 Crater 3 Gas Sensor 4 Temperature Sensor 5 Controller 6 Electromagnetic Flow Control Valve 11 Introduction Duct 12 Supply Passage 13 Acetylene Cylinder 14 Oxygen Cylinder 15 Carbon Dioxide Cylinder 31 Capillary 33 First Flow Sensor 34 Second Flow Sensor 35 35th 3 flow sensor 63 1st solenoid valve 64 2nd solenoid valve 65 3rd solenoid valve W Processed material WS Processed surface

Claims (1)

[Claims] 1. A crater for supplying a C _m H _n- based fuel, oxygen and carbon dioxide to bring the combustion flame of the C _m H _n- based fuel into contact with the surface of the material to be treated, and one of the combustion flames supplied from the crater. A sensor for detecting the amounts of carbon oxide and carbon dioxide, and C _m H according to the carburizing condition based on the equilibrium carbon concentration which is the ratio of the amount of carbon monoxide and the amount of carbon dioxide detected by the sensor.
A controller that outputs a control signal for controlling the supply amounts of the _n- type fuel, oxygen, and carbon dioxide, and C _m H _n based on the control signal from the controller.
A carburizing heat treatment control device comprising a flow rate control device that controls the amounts of system fuel, oxygen and carbon dioxide supplied.