JP3405462B2 - Heating method of work in 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 means for heating, for example, a rotor of a motor as a work and dripping and impregnating an insulating varnish. The mass of the work in the heating furnace varies in velocity and heating. The present invention relates to a method of heating a large work or a small work by adapting them without changing the body temperature.

[0002]

2. Description of the Related Art A simple heating furnace as conventional example 1 of this type
In the case of heating workpieces with different masses
Change the heating temperature, heating time, etc. accordingly.
When dealing with the
Requires equipment for each size of workI
It was Furthermore, a hot air circulation type baking furnace [hereinafter, referred to as "conventional example 2"
Is seen in JP-A-60-106563, and its longitudinal section
The figure is shown in FIG. In this conventional example 2, the circulation fan 608 is heated.
Along the processing material 601 that is installed in the air circulation path 607 and passes through the furnace.
In a hot-air circulation type baking furnace that allows hot air to flow
The hot air circulation path 607 to a position upstream of the circulation fan 608.
If you connect the trachea and install an exhaust fan 610 on this exhaust pipe,
Both are further above this exhaust pipe connection port of hot air circulation path 607.
At the flow position, the catalyst layer 611, the outside air introduction pipe 612, the burner 613, and
Is provided with a heater, and the treatment material inlet 60 in the hot air circulation path 607
3 or a means to detect the temperature difference between the upstream and downstream of the outlet 604.
A step is provided to prevent the temperature difference from exceeding the specified value.
Characterized by automatic adjustment of hot air discharge from the trachea
It is a hot air circulation type baking furnace.

[0003]

However, according to the technique of the conventional example 1 described above, it is attempted to heat works having different large, medium and small masses in the same equipment at the same time and at the same temperature, that is, to carry out a single mixed flow. When heating with radiation, it is almost impossible to reach the same temperature under the same conditions at the same time.In the case of convection, even if the small workpiece has already reached a sufficient temperature, the heating time suitable for the large workpiece There was a problem that the equipment needed a minute station and the equipment became large. Further, the hot-air circulation type baking furnace of Conventional Example 2 is
In the hot air circulation path 607 that circulates the hot air so as to oppose the traveling direction of the processing material 601, that is, in the opposite direction, the temperature difference between the curing zone 606 of the upstream coating solvent and the evaporation zone 605 of the downstream coating solvent. Is a means for automatically controlling so that it becomes a predetermined value, and the treatment material 601 does not flow at random with various large and small masses. For example, in the hot-air circulation type baking furnace of Conventional Example 2. Even if the large and small work pieces are circulated, the bottleneck in Conventional Example 1 cannot be solved. Here, the present invention eliminates the disadvantages of the conventional examples 1 and 2 and can heat various kinds of large and small works within an allowable temperature difference with a facility sufficient for heating a medium work. An object is to provide a method of heating a work in a furnace.

[0004]

In order to achieve the above object, the present invention provides a large work and a small work in a heating furnace.
It tries to guide compressed air and blow it onto it,
That is, when heating works with different masses under the same heating conditions in the same heating furnace, a method for heating works in a furnace is characterized in that compressed air is blown onto the works from a nozzle installed in the furnace. In addition, when mounting the work in the heating furnace, a switching solenoid valve that controls the on / off of the compressed air is instructed by the sequencer based on the information of the mass of the work that is read in advance according to the work type. The method for heating a work in a furnace according to the preceding paragraph, wherein the compressed air is blown automatically according to the mass of the work while the work circulates in the heating furnace.

[0005]

According to the present invention, by means of the above means, even if a large work is heated under the same heating conditions as the small work, a large amount of hot air in the furnace blown by a small amount of compressed air is blown, Compared with the case of simply heating, the temperature can be raised to the necessary temperature without excess or deficiency, and the small workpiece can be prevented from excessive temperature rise due to radiant heat.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged view of the inside of a heating furnace showing an embodiment of the present invention, and FIG. 2 is a front sectional view taken along the cross-section shown in FIG. A ring-shaped heating furnace is formed by a heat insulating material [for example, glass wool] 4 and a heater [for example, a sheath heater] 3, and has a work supporting mechanism 5 arranged at equal intervals on the inner circumference of the heating furnace. With drive means not shown,
The pitch is fed in the direction of arrow A. Further, a hollow brass pipe 1 provided with a plurality of compressed air blowout ports 2 toward the axis of the work supporting mechanism 5 in the space opposite to the heater 3 inside the previous heating furnace is the previous axis. It is installed in parallel with. One end of the brass pipe 1 inside the heating furnace is closed, the other end in the outside air is open, and the brass pipe 1 is connected to the compressed air outlet 2 via a solenoid valve 6 by a tube. The solenoid of the solenoid valve 6 is connected to the output of the sequencer. Incidentally, the overall form of the heating furnace will be described in detail with reference to FIG. 3 showing a front view of another embodiment and FIG. 4 showing a side sectional view of another embodiment. Generally speaking, this type of heating furnace has a rotary drive shaft [revolution shaft 441] at the center of the furnace, and the second disc is reinforced by connecting rods 403 in front of and behind the revolution shaft 441 in the axial direction. 402 ・ First
The circular plates 401 are fixed, and both circular plates are provided with the work supporting mechanisms 5 corresponding to the circle having the same radius from the revolution shaft 441. The workpiece support mechanism 5 also rotates about the rotation shaft 407 [by driving the rotation motor 480 through the idler 10],
Workpiece W between concave centers 472,406 with flanges 473,462
L2, etc. are mounted in pressure contact with a constant output spring 456, etc., and the drive motor 404 allows the gondola [work WM1, WL1, WM2, WS1, ...] at the amusement park to rotate slowly and be viewed. Is similar to what is done. Mounting of these works WLn, WMn, WSn [n = 1, 2, 3, ...] on the work support mechanism 5 is automatically performed by a robot (not shown), such as small work WSn, medium work WMn and large work. WLn is placed on a pallet for each lot within the movable range of the robot, and the pallet is marked with a bar code or the like indicating the type of work.

The operation will be described below. The small work WSn, the medium work WMn, and the large work WLn, which are randomly introduced into the previous heating furnace, are sequentially supported by the work supporting mechanism 5 and pitch-fed in the heating furnace in the direction of arrow A. Further, the large, medium and small of the input work is stored in the memory of the sequencer by a bar code and a bar code reader not shown, and the sequencer always manages which station currently has a work of which size. is doing. The station where the brass pipe 1 is installed is also instructed to the sequencer in advance. In this state, only when the large work WLn and the small work WSn are in the station where the brass pipe 1 is installed, the sequencer switches the solenoid valve 6 to compress the compressed air into the large work WL1 or the small work WS1 through the compressed air outlet 2. Spray as an air stream 8. FIG. 5 is a work temperature curve corresponding to the heating time when the small work WSn, the medium work WMn, and the large work WLn are heated in the previous heating furnace. When the work temperature curve 51 of the medium work WMn is used as a reference, Difference between the work temperature curve 54 when compressed air is blown on the small work WSn and the work temperature curve 55 when compressed air is not blown without such an operation, and the compressed air is blown on the large work WLn. The difference between the work temperature curve 52 at the time of heating and the work temperature curve 53 at the time of not blowing compressed air is remarkable, and according to the present invention, the heating time is shortened from time t2 to time t1. That is, (TM-TL1) <(TM-TL2)
And (TS1-TM) <(TS2-TM). Therefore, since the work temperature TM of the medium work WMn hardly changes, it is an object of the present invention to reduce the difference from the work temperature TM of the medium work WMn, so that the left side of these inequalities becomes zero as much as possible. By setting conditions (constants such as heating body temperature and work speed), an ideal heating furnace can be obtained. That is, the present invention is characterized in that the large work WLn rises in temperature faster and the small work WSn is prevented from excessive temperature rise as compared with the case where the compressed air is not blown. Although there are two types of heating, one is by radiation and the other is by convection. It takes a relatively long time if only convection is used, and the phenomenon in which the magnitude of the mass leads to a difference in the work temperature at the same time when only radiation is applied is skillfully captured. .

[0008]

As described above, according to the present invention, it is possible to heat a large-sized, medium-sized, and small-sized work piece having a large number of mixed products with a single relatively small heating device, that is, a large work piece. Even if the heating sequence for medium and small workpieces is completely at random, it can be done in an orderly manner without excess or deficiency, and the same heating can be performed with one device for many types of workpieces.
It is possible to achieve a special effect that the heating can be automated regardless of the heating time and heating rate .

[Brief description of drawings]

FIG. 1 is a mechanical configuration diagram of a part in a heating furnace according to an embodiment of the present invention.

FIG. 2 is a side sectional view and an electric control system diagram taken along the line − of the embodiment of FIG.

FIG. 3 is a front view of the overall configuration of another embodiment of the present invention.

FIG. 4 is a side view showing a main portion of another embodiment of the present invention with a part cut away.

FIG. 5 is a comparative work temperature characteristic diagram of an example of the present invention and conventional example 1.

FIG. 6 is a block diagram illustrating a mechanical configuration of a conventional example.

[Explanation of symbols]

1 brass pipe 2 Compressed air outlet 3 heater 4 insulation 5 Work support mechanism 6 Solenoid valve 7 Sequencer 8 compressed air flow 8a compressed air 9 Hot air flow 10 idlers 11 Exhaust damper 12 Support roller 51 Medium workpiece temperature characteristic curve 52 Large workpiece temperature characteristic curve of the present invention 53 Large workpiece temperature characteristic curve of conventional example 54 Small workpiece temperature characteristic curve of the present invention 55 Small workpiece temperature characteristic curve of conventional example 401 First disk 402 Second disk 404 drive motor 406 concave center 407 Spindle 441 Revolution axis 456 constant output spring 480 Motor for rotation 472 concave center Ws1 small work Ws2 small work Wsn small work WM1 Medium work WM2 Medium work WMn Medium work WL1 large work WL2 large work WL3 large work WLn large work

Claims (2)

(57) [Claims] 1. When heating works having different masses in the same heating furnace under the same heating conditions, compressed air is blown only from a large work and a small work from a nozzle installed in the furnace. A method for heating a work in a furnace, which is characterized by the above. 2. A switching solenoid valve for controlling ON / OFF of compressed air according to a command from a sequencer based on information of a mass of a work read in advance according to a type of the work when the work is mounted on a heating furnace. The method for heating a work in a furnace according to claim 1, wherein the compressed air is blown automatically according to the mass of the work while the work is circulating in the heating furnace.