JP2558657Y2 - Hot air circulation furnace - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-air circulating furnace in which gas is sucked from a suction port opened in the furnace and supplied from an outlet to the heat treatment furnace again.

[0002]

2. Description of the Related Art A circulating hot air furnace heats a gas flowing through the gas flow path to a preset temperature by sucking gas in the furnace from a suction port and circulating the gas into the furnace again from an air outlet. Alternatively, a temperature control device for cooling is provided. This temperature control device compares the detected temperature with a preset temperature based on an output signal of a temperature sensor for detecting a temperature in the furnace, and generates a gas flowing through a gas flow path according to the temperature difference. The temperature of the supplied air is kept constant by heating or cooling. A large number of hot air outlets are provided along the vertical and longitudinal directions of the furnace so that the temperature distribution in the furnace is not deviated, and hot air at a predetermined temperature is uniformly supplied to the furnace throughout the furnace. The temperature in the furnace is kept constant and a uniform temperature distribution is obtained.

[0003]

[Problems to be Solved by the Invention] However, since the high-temperature gas is light, even if hot air is blown into the furnace uniformly, the furnace inside becomes hot, and the furnace floor where the work is carried in is heated to a predetermined temperature. May not be possible. Even when the furnace temperature is maintained at the set temperature, if the height of the work is close to the furnace ceiling, the upper end is overheated and can be heated uniformly. And may cause poor quality.

Further, depending on the shape of the work, the amount of heat required to heat it to a predetermined temperature may be partially different, and it has been impossible to heat such a work uniformly. Furthermore, depending on the type of work, for example, when it is desired to partially heat-treat the first half at a high temperature and perform heat treatment at the second half at a relatively low temperature, it is impossible to perform heat treatment by arbitrarily setting the temperature distribution in one furnace. there were.

[0005] In view of the above, according to the present invention, even though the furnace temperature has reached a predetermined temperature, the workpiece does not partially reach the predetermined temperature, only the upper end of the workpiece is excessively heated, or the workpiece is not heated. As a technical issue, it is possible to uniformly heat the whole work so that it is not heated partially by the shape, and to be able to set the temperature distribution inside the furnace arbitrarily. I have.

[0006]

In order to solve this problem, the present invention relates to a gas flow path that sucks gas from a suction opening formed in a furnace and supplies the gas to the furnace through an air outlet again. In a hot air circulating furnace provided with a temperature control device for heating or cooling the gas to a preset temperature, a plurality of the air outlets are formed, and each air outlet adjusts the direction or amount of hot air. A wind direction / air volume adjusting means is provided, a reference temperature sensor for detecting a reference temperature in the furnace is provided in the furnace, and a plurality of temperature sensors for detecting a temperature distribution of the work are provided in the furnace. A temperature control device that determines a heating amount or a cooling amount of the temperature control device by comparing the temperature detected by the sensor with a preset temperature, and a temperature distribution of the workpiece detected by the plurality of temperature sensors is preset. Temperature distribution and ratio Characterized by comprising a temperature distribution control device for adjusting the wind direction or air flow from each outlet to.

[0007]

According to the present invention, the furnace temperature detected by the reference temperature sensor installed in the furnace is compared with a preset temperature, and the gas supplied into the furnace is heated to a predetermined temperature. When hot air is blown into the furnace from the outlet, the work is heated by the heat. At this time, if the hot air is uniformly blown out from all the outlets, the furnace temperature becomes higher on the ceiling side, and the temperature distribution of the work is lower in the lower part and higher in the upper part. Therefore, for example, when heating while maintaining a uniform temperature distribution of the work, the temperature distribution of the work is detected by each temperature sensor, and when the temperature on the upper end side is high, for example, the wind direction of the outlet formed at the upper side is detected. The workpiece is heated with a uniform temperature distribution by turning downward or reducing the amount of air blown from the upper outlet to increase the amount of air blown from the lower outlet. Also, for example, when the front half of the work is heat-treated at a high temperature and the rear half is heat-treated at a relatively low temperature, the detected temperature distribution is compared with a preset temperature distribution, and the work is blown out from a rear outlet. By reducing the amount of air flow, the amount of air blown from the front outlet increases, so that the front half and the rear half of the work are heat-treated at different temperatures.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings. FIG. 1 is a flow sheet showing the hot air circulation furnace of the present invention.

In the drawing, reference numeral 1 denotes a hot-air circulation furnace for heat-treating a work W carried in by a conveyor 2, which is opened in a furnace wall by sucking gas in a furnace 4 from a suction port 3 opened in a ceiling portion. Gas flow path 6 circulating from outlet 5 to furnace 4 again
Are formed. A circulation fan 7 for circulating gas in the furnace 4 is provided at the suction port 3,
Inside, a temperature control device 8 for heating or cooling the gas sucked from the furnace 4 to a preset temperature is provided.

A plurality of outlets 5 and 5 are vertically opened along the furnace wall, and are formed at predetermined intervals along the longitudinal direction of the furnace 1. Each of the outlets 5 has a cylindrical shaft 9 rotatably engaged with the outlet 5 so that the wind direction can be adjusted in the up-down direction and the front-back direction. A hemispherical nozzle 11 is rotatably engaged. Reference numerals 12 and 13 denote motors for rotating the cylindrical case 9 and the nozzle 11 by a predetermined angle, respectively.

In the furnace 4, a reference temperature sensor S ₀ for detecting a reference temperature of the furnace 4 is installed, and a work W
Temperature sensors S _1, S _2, S for detecting the temperature distribution of
₃ is attached to the surface of the work W, a cage for carrying the work W, and the like. 14 compares the furnace temperature detected by the reference temperature sensor S ₀ with the temperature preset by the setting device 15 to determine the heating amount of the temperature control device 8 disposed in the gas flow path 6 or The temperature control device 16 for determining the cooling amount compares the temperature distribution detected by the temperature sensors S _1, S _{2, and} S ₃ with the temperature distribution preset by the setting device 15 to determine each measurement point. Motor 1 according to the temperature difference at
This is a temperature distribution control device that adjusts the wind direction from each outlet 5 by moving 2 and 13.

The above is an example of the configuration of the present invention, and its operation will be described below. First, when trying to uniformly heat the workpiece W, first furnace temperature detected by the reference temperature sensor S ₀ continues to heat up to temperature controller 8 reaches a set temperature. At this time, the conditions of the temperature distribution are set so that the measured temperatures at the respective measurement points become uniform, that is, the temperature sensors S _1, S _2,
T ₁ = T ₂ = T ₃ is set so that the temperatures T _1, T _2, T ₃ detected in S ₃ are equal. Then, the hot air heated by the temperature control device 8 is blown out from each of the air outlets 5, 5,.
_The temperature distribution detected at _1, S _{2 and} S ₃ is T ₁ <T ₂ <T
_In the case of ₃ , since the temperature of the upper part is too high, the nozzle 11 of the upper outlet 5 is moved to adjust the blowing direction of the hot air downward.

Next, the temperature inside the furnace is further increased, and the hot air directly hits the work, thereby causing the work W
Is heated so that the temperature distribution becomes T ₁ > T ₂ > T ₃ , so that the hot air blown from the upper outlet 5 toward the work W does not directly hit the work W. Alternatively, the direction of the nozzle 11 is adjusted so as to blow out slightly upward. In this way, by detecting the temperature distribution of the work W, adjusting the direction of the nozzle 11 based on the temperature distribution and blowing out hot air, it is possible to uniformly heat the work W regardless of the shape of the work W, There is no product failure due to partial heating.

When the front half and the rear half of the work W are heat-treated at different temperatures, the rotary shaft 10 is turned upright by rotating the cylindrical case 9 by 90 ° so that the wind direction can be adjusted in the front-rear direction. For example, when the front half is heat-treated at a high temperature, the nozzle 11 may be directed forward. The air outlet 5 is not limited to the case where the wind direction is changed, and may have a damper to change the air volume. In this case, based on the detected temperature distribution, the amount of hot air blown out from the outlet 5 facing the high temperature portion is reduced, so that the hot air blown out from the outlet 5 facing the low temperature portion. By increasing the amount, heating can be performed uniformly, and these may be used in combination. further,
The air outlet 5 is not limited to the case where it is rotatable with respect to two orthogonal axes, and may be, for example, a case where it rotates only in the vertical direction or a case where it rotates only in the front-rear direction.

[0015]

As described above, according to the present invention, the temperature distribution of the work is directly detected and the direction or amount of hot air is adjusted, so that the furnace temperature reaches a predetermined temperature. Despite the fact that part of the work does not reach the predetermined temperature, only the upper end of the work is excessively heated,
Further, there is an extremely excellent effect that the entire work can be uniformly heated without being partially heated depending on the shape of the work, and the temperature distribution in the furnace can be arbitrarily set.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing a hot air circulation furnace according to the present invention.

[Explanation of symbols]

1 Hot air circulation furnace 2 Conveyor W Work 3 Inlet 4 Inside furnace 5 Outlet 6 ... gas flow channel 7 ----- circulation fan 8 ----- temperature controller 11 ..... nozzle (wind direction adjusting means) S ₀ · · · · reference temperature sensors S _1, S _2, S ₃ Temperature sensor 14 Temperature control device 16 Temperature distribution control device

Claims (1)

(57) [Scope of request for utility model registration] 1. A gas flow path (6) for sucking gas from a suction port (3) formed in the furnace (4) and circulating and supplying the gas from the outlet (5) to the furnace (4) again. In the hot air circulating furnace provided with a temperature control device (8) for heating or cooling a gas to a preset temperature, the outlet (5)
Are formed, and each air outlet (5) is provided with a wind direction / air volume adjusting means (11) for adjusting the wind direction or air volume of the hot air, and the inside of the furnace (4) is provided with the inside of the furnace (4). A reference temperature sensor (S ₀ ) for detecting a reference temperature is provided,
A plurality of temperature sensors (S ₁ , S ₂ , S ₃ ) for detecting the temperature distribution of the work (W) are provided, and the reference temperature sensor (S
₀₎ temperature controller to determine the amount of heating or cooling of comparison to temperature controller with a preset temperature detected temperature (8) and (14), said plurality of temperature sensors (S _1, S ₂ ,
A temperature distribution control device (16) for adjusting the wind direction or air volume from each outlet (5) by comparing the temperature distribution of the work (W) detected in S ₃ ) with a preset temperature distribution; A hot air circulation furnace.