JPS61157623A - Heat treatment apparatus - Google Patents

Abstract

PURPOSE:To obtain the titled apparatus capable of the small-sizing and the automation of an installation by constituting it so that an endless loop belt which is held and provided on an aperture of upper part of a heat-treating bath vessel is sent into the bath vessel in a prescribed velocity and also the suspension height thereof is made capable of regulation. CONSTITUTION:At least a belt 23a in an upper part side of an endless loop belt 23 which is held with plural belt suspending axes 24-27 is provided to the upper part of an aperture of an upper part opening type heat-type heat- treating bath vessel 21 and the above-mentioned loop belt 23 is sent into the above-mentioned bath vessel 21 in a prescribed velocity with the axes 24, 27 rotated synchronously by a driving device (is not shown) provided to the outside of the bath vessel 21. The suspension height of the belt 23a in the inside of bath vessel 21 or in the upper part thereof is regulated by siding the belt suspending axis 26 right and left along a horizontal long hole 35 provided to a shielding plate 31. Thereby the treatment in a heat-treating bath 22, the movement after the takeout therefrom and the conveyance for the material to be heat-treated which is loaded on the belt 23a can be performed automatically and efficiently.

Description

[Detailed Description of the Invention] CObject of the Invention] (Industrial Application Field) The present invention relates to a heat treatment apparatus used for heat treatment of, for example, mechanical structural parts, specifically automobile parts and electrical parts. be.

Conventionally, mechanical structural parts are often subjected to heat treatments such as quenching and tempering or surface hardening treatments in order to improve their mechanical properties and wear resistance. A cooling process is then performed, and air cooling may be used as the cooling method, but in some cases, a heat treatment bath using oil or a fluidized bed may be used.

FIG. 10 shows a conventional batch type heat treatment apparatus using a so-called basket. In this heat treatment apparatus 1, objects to be heat treated are set in a basket 2, and this basket 2 is placed at a predetermined position in a heat treatment bath 4 by a suspension jig 3. A chain hoist, a guide rail, or the like is used to transport the basket 2.

FIG. 11 shows a conventional continuous heat treatment apparatus using a so-called mesh belt. This heat treatment device 11
In this heat treatment apparatus 11, the object to be heat treated is placed on a mesh belt 17F held by a plurality of belt shafts 12 to 16, and passes through the heat treatment bath 1B. Since the setting can be easily performed by using free fall from other conveying means, automation is easy, and continuity can be provided during heat treatment, making it highly productive. .

(Problems to be Solved by the Invention) However, in the conventional batch type heat treatment apparatus 1 shown in FIG.
It is difficult to automate the loading and unloading of materials to be heat treated, and this poses a problem in that productivity is significantly impaired. Furthermore, since the basket 2 has a structure that is suspended from above, it is difficult to turn the heat-treated object upside down, and there is also the problem that it cannot be applied when it is necessary to turn the heat-treated object upside down. Ta.

In addition, in the conventional continuous heat treatment apparatus 11 shown in FIG. There is a problem in that a large angle cannot be provided, a large installation space is required, and a large amount of heat treatment bath 18 is therefore used. In addition, the object to be heat treated is mesh belt 17.
Since the object to be heat treated is transported while being placed on top of the object, it is not possible to perform up-and-down movement, 9-rotation movement, up-and-down reversal movement, etc. Therefore, there is also the problem that it cannot be applied when such movement is required. there were.

Therefore, in order to solve such problems.

It has been considered to divide the belt in the heat treatment bath and provide a separate device for pulling up the objects to be heat treated, but if such a device was installed, it would be necessary to A shaft sliding part is required, and the shaft sliding part may be affected by the heat treatment bath and require early replacement.
A new problem has arisen in that it is impossible to employ this method if it is not possible to provide a sliding part within the heat treatment bath.

This invention was made by focusing on the above-mentioned conventional problems, and it is not necessary to provide a sliding part in the heat treatment bath, the heat treatment bath can be made small, and automation is easy. Moreover, it is an object of the present invention to provide a heat treatment apparatus that is capable of vertically inverting and relocating objects to be heat treated.

[Structure of the Invention] (Means for Solving the Problems) A heat treatment apparatus according to the present invention solves the above-described conventional problems, and includes a plurality of belts suspended above the opening of a top-opening heat treatment bath. disposing at least an upper belt of an endless loop belt held by a shaft; a drive installation for feeding the loop belt into the heat treatment bath at a predetermined speed; and a suspension length of the upper belt between the belt suspension axes. The structure includes a suspension height adjustment device that adjusts the height of the upper belt and changes the suspension height of the upper belt in or above the heat treatment bath.

(Example 1) FIGS. 1 to 4 are diagrams showing an embodiment of the present invention. In FIGS. 1 and 2, 21 is a heat treatment bath, and 22 is a heat treatment bath. As this heat treatment bath 22,
Oil (for example, high temperature quenching oil), fluidized bed (for example, alumina powder), etc. are used.

Further, 23 is an endless loop belt.

This loop belt 23 has a plurality of belt suspension shafts 24, 25.
, 26.27. Hereinafter, the loop belt 23 located between the belt suspension shafts 24 and 25 will be referred to as the upper belt 23a, and the belt suspension shaft 24 and 25 will be referred to as the upper belt 23a.
．． Loop belt 23 between 27 and lower belt 23b
Among the above, the belt suspension shaft 24 is composed of multiple sprockets in this embodiment, and as shown in FIG.
In a horizontal orientation above the heat treatment bath 21, the shielding plate 31.3
Support plate 3 via transmission shafts 24a, 24a passing through 1
2. It is rotatably supported by a bearing provided in 32,
The rotational driving force of a drive device 34 is transmitted to the one transmission shaft 24a via a transmission belt 33. The belt suspension shaft 24 is rotated by the rotational force from the drive device 3, so that the loop belt 23 can be fed into the heat treatment bath 22 at a predetermined speed.

Further, the belt suspension shaft 27 is connected to the belt suspension shaft 24.
Similarly, the support plates sz, 3z are rotatably mounted via bearings, and are connected to the drive device 34 to rotate in synchronization with the belt suspension shaft 24,
In this case as well, it is composed of multiple sprockets. By rotating the belt suspension shaft 27 in synchronization with the belt suspension shaft 24, the length of the lower belt 23b of the loop belt 23 is kept constant.

Further, the belt suspension shaft 25 is disposed in a horizontal state like the belt suspension shaft 24, and is rotatably supported by bearings provided on the support plates 32, 32, and together with the belt suspension shaft 24, the belt suspension shaft 25 is disposed horizontally. The belt 23a is configured to be suspended in and above the heat treatment bath 22. In this case, the belt suspension shaft 25 is a freely rotatable multiple sprocket installed above the heat treatment bath 21.

Further, the belt suspension shaft 26 is connected to the other belt suspension shaft 24 .
25 and 27 can be changed at any time. In this embodiment, it is composed of freely rotating multiple sprockets, and is disposed inside the loop belt 23.

The shielding plates 31, 31 are installed to prevent the heat treatment bath medium from scattering and to prevent the objects to be heat treated from falling in the lateral direction. The shielding plate 31 is formed with horizontal long holes 35, and the supporting plate 32 is also formed with the long holes 35.
A long hole is formed opposite to the belt suspension shaft 26, and the belt suspension shaft 26 slidably passes through the long hole 35, and the belt suspension shaft 26 passes through the long hole 35 through a bearing that slides horizontally in the long hole provided in the support plate 32. Each of them is supported by a support plate 32, and these mechanisms constitute a suspension height adjustment device that changes the suspension height of the upper belt 23a.

(Function) Next, the operation of the heat treatment apparatus having the above configuration will be explained with reference to FIGS. 3 and 4.

By using the heat treatment apparatus configured as described above and moving the belt suspension shaft 26, the upper belt 23a of the loop belt 23 is changed from the state shown in FIG. 1 to the state shown in FIG. 3. I can do it.

That is, in the state shown in FIG. 4(A) where the belt suspension shafts 24 and 27 are stopped or rotating synchronously, the belt suspension shaft 26 is moved in the horizontal direction to the state shown in FIG. 4(B). When the belt suspension shafts 24 and 27 are stopped or rotated synchronously, the length of the lower belt 23b of the loop belt 23 does not change and the length of the lower belt 23b remains unchanged.
However, since the belt suspension shaft 25 is provided to be freely rotatable, the upper bell (23a) gradually moves upward, and as shown in FIG.
2, and the belt suspension shaft 26 is moved further in the horizontal direction than in FIG. 4(B), the upper belt 23a becomes almost tensioned as shown in FIG. 4(C).

A heat treatment apparatus with such movement can perform various heat treatment operations, such as: (1) carrying out the heat treatment object from the heat treatment bath 22, (2) transferring the heat treatment object in the heat treatment bath 22, (2) heat treatment. The explanation will be divided into the transfer of the object to be heat treated on the bath 22.

■ Carrying out the object to be heat-treated from the heat treatment bath 22 The object to be heat-treated has undergone a prescribed heat treatment on the upper belt 23a in the state shown in FIG. 4(A), and the belt suspension shaft 26 moves in the horizontal direction. As the length between the belt suspension shafts 24 and 25 becomes shorter, the lower end of the upper bell 23a rises, and as shown in FIG.
Out from 2. Then, the belt suspension shaft 26 further moves in the horizontal direction to the state shown in FIG. The object to be heat treated is conveyed on the loop belt 23 and falls from the end on the suspension shaft 26 side, as in the case of the above.

By utilizing such movement of the loop belt 23, the objects to be heat treated can be easily carried into and out of the heat treatment bath 22 without using a basket that requires manual labor to take in and out the objects to be heat treated. , automation becomes easier.

Also in this case.

There is no need to use any special belt as the loop belt 23, and by giving a steep angle to the loop belt 23, it is possible to hold and transport the heat-treated material in the heat treatment bath well, which is different from the conventional method. It is possible to work in a narrow space, which is completely impossible with a continuous heat treatment apparatus as shown in FIG. 11, and it is also possible to perform heat treatment using a heat treatment bath 22 with a small area (volume). .

Further, in this embodiment, only a part of the loop belt 23 is immersed in the heat treatment bath 22, and all components other than the loop belt 23, such as the belt suspension shafts 24 to 27, are outside the heat treatment bath 22. This makes maintenance and inspection of the equipment extremely easy. Such a configuration has great advantages, especially when it is difficult to provide a sliding part or the like in the heat treatment bath 22, such as when a fluidized bed is used as the heat treatment bath 22. When using a fluidized bed, only a basket system could be adopted, and this had a significant problem in workability, but according to the above embodiment, such problems can be easily solved.

■Transfer of the object to be heat treated in the heat treatment bath 22 In the heat treatment apparatus according to this embodiment, the object to be heat treated is subjected to a predetermined heat treatment on the upper bell 23a of the loop belt 23 in the state shown in FIG. 4(A). During the process, the belt drive shaft 26
If the belt drive shafts 24 and 27 are rotated by driving the drive device 34 while the belt is stopped, the object to be heat treated on the upper belt 23a in the heat treatment bath 22 is rolled (transferred violently if necessary). Such an operation can be done by
Stirring the heat treatment bath 22 equalizes the temperature and improves the heat transfer coefficient between the hot medium constituting the heat treatment bath 22 and the object to be heat treated. This effect is beneficial in the case of heat treatment baths, such as fluidized beds, where the heat transfer medium is deposited on the object to be heat-treated, reducing the heat transfer coefficient, and where the heat transfer medium is likely to stick to the object to be heat-treated. In contrast to fluidized bed heat treatment baths, which are said to be effective, but whose lack of cooling capacity during quenching is said to be preventing widespread practical use,
The method according to this invention is extremely effective. On the other hand, in the normal mesh belt method, the object to be heat treated placed on a quietly moving belt only moves quietly with the belt, and there is almost no effect of stirring the heat treatment bath, much less. On the other hand, with the basket method, it is impossible to expect the removal of air bubbles attached to the surroundings of the heat-treated object or the improvement of heat transfer coefficient.On the other hand, depending on the basket method, the heat-treated object can be slightly moved vertically or rotated around the vertical axis. In this respect, it can be said to be more advantageous than the Metschwerd method, but it is not possible to expect large movements equivalent to upside down or falling, and it is difficult to equalize the heat treatment bath temperature and heat treatment due to the movement of the basket. There were limits to improving conductivity.

■Transfer of the object to be heat treated on the heat treatment bath In the heat treatment apparatus according to the present invention, as shown in FIG. By being driven by the device 34, while the object to be heat treated after having undergone a predetermined heat treatment in the heat treatment bath 22 is carried out of the heat treatment bath 22, the object to be heat treated is subjected to a transfer movement (up and down) above the heat treatment bath. ), including reversal motion, which cannot be obtained with other basket methods or mesh belt methods.

Such an operation has the effect of promoting the fall of the heat medium adhering to the object to be heat-treated after the heat treatment, separating from the object to be heat-treated and returning to the heat treatment bath 22. Such an effect is particularly effective. This becomes more noticeable when the object to be heat-treated has a shape such as a plate or bowl that tends to accumulate heat medium, or when a highly viscous substance or fine particles are used as the heat medium, resulting in a decrease in the amount of supplementary heat medium and a decrease in heat transfer. This can bring great advantages such as a reduction in the number of steps required for media separation and recovery.

In the heat treatment apparatus having the structure shown in FIGS. 1 and 2, the upper belt 23a of the loop belt 23 and

Since both the upper and lower side bells 23b are located within the heat treatment unit 22, the heat treatment apparatus main body 2 including the heat treatment bath 22
It is possible to separate the loop belt 23 and its drive mechanism from the loop belt 23 and its drive mechanism, which facilitates maintenance and inspection of each. For example, when different heat treatment baths are installed side by side, the loop belt 23 and its drive mechanism can be separated. It becomes possible to use the bath in common with the plurality of heat treatment baths mentioned above.

(Embodiment 2) FIG. 5 shows another embodiment of the present invention. In FIG. 5, 41 is a heat treatment bath, and 42 is a heat treatment bath. As this heat treatment bath 42, oil, a fluidized bed, or the like is used as described above.

Further, 43 is an endless loop belt, and this loop belt 43 has a plurality of belt suspension shafts 44, 45, 46 .
It is held by 47. In this case, the belt suspension shaft 4
4.45 is installed at the upper end of the heat treatment equipment main body 41,
The upper bell 43a is held suspended between the belt suspension axes 44, 45, and the belt suspension axes +5, 46.

The lower belt 43b is suspended between 47 and 44.

The belt suspension shaft 44 is connected to the loop belt 4
3 into the heat treatment bath 42 at a predetermined speed, and the belt suspension shaft 45 is connected to the belt suspension shaft 4 of the upper belt 43L.
The upper belt 431 is connected to a suspension height adjusting drive device 55 that adjusts the suspension length between 4.45 and 45 to change the suspension height of the upper belt 431 within and above the heat treatment bath 42.

(Function) In the heat treatment apparatus shown in this second embodiment, the drive device 54
When the loop belt 43 is rotated at a predetermined speed by driving the driving device 55 to rotate the belt suspension shaft 44 at a speed synchronized with the rotation, and the loop belt 43 is rotated at a predetermined speed, the heat treatment bath The object to be heat treated can be transferred within 42. When the rotational speed of the drive device 55 is relatively increased, the upper belt 43a gradually rises together with the object to be heat treated, and when the lower end of the upper belt 43a is located above the heat treatment bath 42, the drive device 5
When the rotation of the belt suspension shaft 4'5 by 5 is synchronized with the rotation of the belt suspension shaft 44, the object to be heat treated is transferred to the heat treatment bath 42.
It can be rolled on top. Furthermore, if the rotational speed of the belt suspension shaft 45 by the drive device 55 is relatively increased.

The object to be heat treated is carried out from the end of the belt suspension shaft 45.

In this way, in Example 2 as well,
It is possible to perform a heat treatment operation similar to that shown in FIG. 1, and it is possible to transport and transfer objects to be heat treated, and it is also possible to agitate the heat treatment bath 42 and improve the heat transfer coefficient.

In the case of this second embodiment, since the lower belt 43b is located outside the heat treatment bath 42, it is possible to take a larger effective dimension of the heat treatment bath 42, and there is an advantage that less heat medium is carried out. have. Therefore, the apparatus according to the second embodiment is effective when there is no need to separate the heat treatment main body 41 and the heat treatment bath 42 from the loop belt 43 and its drive mechanism, and when it is desired to obtain a larger effective capacity of the heat treatment bath. .

(Test Example 1) In the heat treatment apparatus shown in FIGS. 1 and 2, high-temperature quenching oil is used as the heat treatment bath 22.
2, a heat-treated object 57 made of spheroidal graphite cast iron having the shape shown in FIG. 6 (D+ = 30m).

D2 = 100 + w + s, T = 20 + m intestines: 18 in total) were held at 250°C, and the temperature distribution in the vertical direction within the heat treatment bath 22 was measured. At this time, the heat treatment bath 22 is not particularly stirred by the stirring device, and the loop belt 23
The rotational speed was set to be a feed of 100 arm/sec. In addition, the temperature measurement should be performed once after the device is stopped.
The time was between 0 and 30 seconds. This temperature distribution measurement result is
As shown in the figure.

Also, for reference, the major axis is -400++ m and the minor axis is 300 m.
+am, using a basket made of mesh netting with a height of 25 mm, the objects to be heat treated were arranged in 9 3 x 3 layers in one layer, then set in the basket in two tiers, and immersed in the heat treatment bath. The movement is 0.5Hz at the center of the heat treatment bath,
A vertical motion with an amplitude of 100 cm and a rotational motion of 0.5 Hz with the center width of the basket as the center of rotation were combined. The temperature distribution measurement results in this case are also shown in FIG.

As shown in Figure 7, in the test example according to the present invention, the temperature distribution of the heat treatment bath is quite uniform, whereas in the case of the basket method of the reference example, the temperature distribution of the heat treatment bath is quite wide. Met.

(Test Example 2) Next, heat-treated objects 57 (18 pieces in total) made of spheroidal graphite cast iron and having the shape shown in Fig. 6 and heated to 850°C were placed in the first
In each of the heat treatment apparatus according to the present invention shown in the figure and the conventional basket type heat treatment apparatus shown in FIG. Look 1=10+m, Sentence 2=
The microstructure of a 15 mm section was observed. Note that other conditions were the same as in Test Example 1 above. The results of this tissue observation are shown in FIGS. 8 and 9.

As shown in Figure 9, in the case of the reference basket method, some pearlite is observed in the structure, whereas
As shown in FIG. 8, when the heat treatment apparatus according to the present invention is used, no pearlite is observed at all, and it is clear that the cooling capacity is considerably improved when the heat treatment apparatus according to the present invention is used.

[Effects of the Invention j] As described above, the heat treatment apparatus according to the present invention is characterized in that at least the upper belt of the endless loop belt held by a plurality of belt suspension shafts is disposed above the opening of the top-opening heat treatment bath. and a drive installation for feeding the loop belt into the heat treatment bath at a predetermined speed, and adjusting the suspension length of the upper belt between the belt suspension axes to cause the upper belt to move into the heat treatment bath or its surroundings. Since the structure is equipped with a suspension height adjustment device that changes the suspension height above, there is no need to provide a sliding part in the heat treatment bath, and the heat treatment bath can be made smaller. , it is easy to automate the heat treatment work, it is easy to maintain and inspect the equipment, it is possible to turn the heat treatment object upside down and move it inside and outside the heat treatment bath, and it is possible to move the heat treatment object inside and outside the heat treatment bath. The heat transfer efficiency in the heat treatment bath can be improved, and even if the heat treatment bath is a fluidized bed, it is possible to obtain a considerable cooling capacity, and other excellent effects are brought about.

[Brief explanation of the drawing]

1 and 2 are horizontal and vertical cross-sectional views, respectively, of a heat treatment apparatus according to an embodiment of the present invention;
Figure 3 is a vertical sectional view showing the belt suspension shaft (26) at its sliding end in the device of Figure 1; Figure 4 (A)
(B) (C) are explanatory diagrams of main parts showing changes in the movement of the heat treatment apparatus shown in FIG. 1, FIG. 5 is a lateral vertical sectional view of a heat treatment apparatus according to another embodiment of the present invention, and FIG. Figure 7 is a cross-sectional view of the object to be heat treated used in the example, and Figures 8 and 9 are graphs showing the results of measuring the temperature distribution of the heat treatment bath.
The figures are micrographs of metallographic structures investigated in test examples and reference examples of the present invention, Figure 10 is a cross-sectional explanatory diagram of a conventional basket-type heat treatment apparatus, and Figure 11 is a cross-sectional explanatory diagram of a conventional mesh belt-type heat treatment apparatus. It is. 21.41...Heat treatment bathtub, 22.42...Heat treatment bath, 23.43...Loop belt, 23a, 43a...Upper side belt, 23b, 43b...Lower side belt, 24.25 .26, 27.44, 45.46°47...
・Belt suspension shaft, 34, 54...Loop belt drive device, 57...
Object to be heat treated. Patent Applicant: Nissan Motor Co., Ltd. Representative Patent Attorney Yutaka Oshio Figure 1 (C') Figure 5

Claims (1)

[Claims] (1) At least the upper belt of an endless loop belt held by a plurality of belt suspension shafts is disposed above the opening of the top opening type heat treatment bath, and the loop belt is moved into the heat treatment bath at a predetermined speed. Drive installation to send,
A suspension height adjustment device is provided to adjust the suspension length of the upper belt between the belt suspension axes and change the suspension height of the upper belt in or above the heat treatment bath. Heat treatment equipment.