JPS607371B2 - heat dissipation container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat dissipation container, particularly to a heat dissipation container for oil-filled electrical equipment.

Among various types of heat dissipation containers in oil-filled electrical equipment,
One of the most efficient heat dissipation containers is a thin metal plate that forms a flow path for insulating oil as a cooling medium.
The thin metal plates with the flow channels are welded into a tubular shape, and this is used as a unit heat radiator. Multiple heat radiators are assembled using headers, etc., and these are welded together and sealed to form a panel type. There is a heat sink.

When this type of heat dissipation container is used as a heat dissipation device for a transformer, for example, the joint part with the transformer etc. is quite long, which requires a large number of man-hours, and also causes quality problems. There is also a high possibility that oil leakage may occur due to defects in welded parts, and the welding and sealing process requires great care, resulting in noticeable loss of work time.

Recently, in order to eliminate these drawbacks, a heat radiating container is used in which a large number of unit heat radiating ribs for circulating oil are provided on the outer periphery of the central portion of the transformer.

An example of a transformer container having this unit heat dissipation rib is shown in FIGS. I and 2. The heat dissipation rib 1 has a plurality of unit heat dissipation ribs formed by continuously bending a steel strip in a wave shape, squeezing the ends of the gates located on both sides in the width direction, and performing welding 4 to form a bag shape. There is.

The heat dissipation container includes an upper side plate 5, a lower side plate 6, and a bottom plate 8.
For example, a frame body is formed by welding to aggregates 7 made of shaped steel, etc., and heat dissipation ribs 1 are arranged on each side of the frame body, and the upper side plate 5, the upper side plate 5,
It is constructed by applying welds 9 and 10 to the lower side plate 6 and the rib cage 7, respectively.

The heat radiating action of the heat radiating container is achieved by circulating oil inside the bag-shaped interior of the unit heat radiating ribs la, and by exchanging heat absorbed by the oil with the outside air on the surface of the unit heat radiating ribs la. To increase the efficiency of this heat exchange, unit heat dissipation rib l
The smaller the oil circulation resistance within a and the interference in heat radiation between adjacent unit heat radiation ribs la, the better. Therefore, the third
As shown in the figure, the larger the pitch P between the oil circulation part lb of the unit heat radiating rib la and the pitch P between the unit heat radiating ribs la, the higher the heat exchange efficiency of the heat radiating container. However, heat dissipation containers used in transformers, etc., must dissipate the generated heat within a certain limited space, so even if the heat dissipation effect of each unit heat dissipation rib is sacrificed, the heat dissipation container as a whole must be To ensure the amount of heat dissipation, unit heat dissipation
The pitch P of is designed to be small within an allowable range. In other words, in order to increase the amount of heat dissipated from the heat dissipation container as a whole,
It is desirable to make the pitch P of the unit heat radiation ribs as small as possible.

However, from the viewpoint of molding the unit heat dissipating ribs la, the smaller the pitch P, the more difficult the machining becomes, so there are naturally restrictions on the setting of the pitch P.

For example, by bending a steel strip into a wave shape, unit heat dissipation ribs can be created.
After forming a, when squeezing the both side ends 3 (see Fig. 2), each adjacent unit heat dissipating rib la
Tension is applied to both end portions lc of the base between them, and these portions undergo cold working.

There is a limit to this lining processing depending on the elongation characteristics of the steel strip, and if the steel strip is processed beyond this elongation characteristic, the material will break and the heat dissipation rib will become unusable. The workability of the portion lc to be subjected to the lining processing is determined by the elongation characteristics of the steel strip, the length of the portion lc to be processed, and the amount of processing. That is, if the length of the processed part lc before processing is c, the length after processing is c + b, so the processed part l
The elongation E of c is expressed by the following equation '11.

E=Tei ‐‐‐‐‐‐(1) Here, the workpiece part lc is elongated by squeezing the both ends 3 of the unit heat dissipation rib 1a, so that the elongation reaches the limit value of elongation of the steel strip material. When it exceeds it, it will be destroyed.

Therefore, in order to prevent the processed part lc from being destroyed by the above-mentioned squeeze process, it is necessary to
o>Which relationship needs to be established?

Therefore, the length c of the processed portion lc before processing must satisfy the following relationship.

C＞No.-.・・・．・(2) The length c of this processed part lc before processing is the thickness of the steel strip t
, when the radius of curvature of the bending part of the unit heat dissipation lip 1a is y, it can be replaced with the following equation: can.

Substituting this formula into the ■ formula and rearranging it, p>(★+・)
b ten(3-many)t+(2-zo亥)y...”[4}.

In order to satisfy the relationship of formula [2}, it is sufficient to make the length c of the processed part lc before machining sufficiently large.In order to increase this length c, as is clear from formula [3'] In this case, the pitch P may be increased, or the medium b, radius of curvature y, and plate thickness t of the oil circulation section lb may be reduced. However, as mentioned above, it is necessary to set the pitch P as small as possible, and if the pitch P in the oil circulation part lb is made smaller than necessary, the pitch P must be set as small as possible, and if the pitch P is made smaller than necessary, the pitch P must be set as small as possible. It cannot be made too small because this will lead to a decrease in heat dissipation efficiency due to an increase in strength and oil circulation resistance.

In addition, since the radius of curvature y is naturally limited by the plate thickness t, it is not possible to reduce only this, and furthermore,
The thickness t of the steel strip cannot be made smaller than necessary from the viewpoint of the strength of the heat dissipating rib 1 and its welding workability.

Therefore, when the dimensions of each part of the heat dissipation rib are set to their respective lower limit values, the lower limit value P, of the pitch P is {from formula 4, F・=(''・)b×(3-hoko)t, etc. ○ Ten (2-summer) y...'5) becomes.

As is clear from the equation {5}, the lower limit value P of this pitch is naturally determined by the limit value of elongation of the material of the heat dissipating rib 1 and the dimensions of each part thereof.

Therefore, after selecting the material of the heat dissipation rib 1, the pitch P of each unit heat dissipation rib 1a cannot be made smaller than necessary.
In terms of heat exchange efficiency, it is practically difficult to set the pitch P. The fact that this pitch P is determined by external factors is a major disadvantage in the design of the heat dissipation container.
In view of the above-mentioned points, an object of the present invention is to further reduce the pitch of each unit heat radiation rib.

Therefore, according to the present invention, there is provided a heat radiating container having high heat exchange efficiency and having heat radiating ribs in which the pitch of the unit heat radiating ribs la is smaller than the lower limit value P described above. That is, in the present invention, the processed parts lc (see FIG. 2) at both ends of the heat radiation rib are bent along the side where the unit heat radiation rib 1a is formed, and the both ends of the heat radiation rib 1 are bent. It is characterized by an outward slope relative to the base (mid abdomen).

4, 5 and 6 are a partial side view and a plan view thereof of the heat dissipation rib 1 provided by the present invention,
Each partially enlarged view is shown.

Assuming that the amount of displacement of the ends relative to the base, which is caused by the slope of both ends of the heat dissipation lip 1 described above, is h, as shown in FIG. When squeeze processing is performed on both ends of the heat dissipation rib 1 (solid line part) and when the same part is squeezed using the conventional method (dash line section), the former case has a better effect on the heat dissipation rib 1. The amount of extension of the end portion can be reduced by twice the amount of displacement h. Therefore, since the elongation at the end of the heat dissipating lip 1 is expressed as a percentage of the elongation amount to the length before processing, b- can be obtained from the equation tl}.
．． ．． ．．・Become a target.

This elongation rod is also similar to the {1-type throat} between the limit value of elongation of the steel strip and the elongation of the steel strip. The following relationship must be established. By the way, please.

>Kitai.・・・-．・(7), and this [7
By substituting the {3} formula into the {3} formula, we get P>(↓+・)
b 10 (3-Li) t Go○ 10 (2-Wind y-2 (U 10) h...(8}).

As is clear from a comparison between this '8} formula and the above-mentioned {4- formula, the pitch P of each unit heat dissipating rib la of the heat dissipating rib 1 provided by the present invention is 2 (1 L + ○1 ), it is possible to make the pitch P of the heat dissipating ribs smaller than the lower limit P, of the conventional heat dissipating ribs.

However, while the amount of displacement h' of the end of the heat dissipation rib 1 with respect to the base is an important factor for reducing the pitch of each unit heat dissipation rib la, the periphery of the heat dissipation rib 1 is When welding to the bone village 7 or the like, the slope formed at the end of the heat dissipating lip 1 will create a gap with respect to the welded part, so the displacement h cannot be easily increased. That is, each of the above-mentioned welded parts needs to be reliably sealed by welding in order to prevent oil leakage from the heat dissipation container.

However, for the heat dissipation rib 1, a relatively thin steel strip is generally used in consideration of economic efficiency, and the upper side plate 6, aggregate 7, etc. are made of the steel used for the heat dissipation rib 1, considering the rigidity of the heat dissipation container. A steel material having a thickness 2 to 3 times or more than the strip is used.
For example, if a steel strip with a thickness of 1.2 mm is used for the heat dissipation rib 1, steel material with a thickness of 3.2 mm is usually used for the other parts. Arc welding of relatively thin plates is generally considered difficult, but in recent years it has become relatively easy due to advancements in shielding gases and improvements in welding power source characteristics.

However, in welding when the gap between the overlapping parts of the welded parts is too large,
Continuous welding becomes impossible because the thinner plate material melts through. For this reason, when manufacturing the above-mentioned heat dissipation container, there is a certain limit to the size of the gap between the periphery of the heat dissipation rib and the individual overlapping parts of the upper side plate 5, the lower side plate 6, and the aggregate 7. In order to perform welding that requires high airtightness such as in a heat dissipation container, the size of the gap described above must be equal to or less than the thickness t of the heat dissipation rib 1. It has been experimentally confirmed that this is not the case. Therefore, the above-mentioned displacement amount h needs to be smaller than at least the thickness t of the steel strip.

Here, when the displacement h is equal to the thickness t, the minimum value P2 of the pitch of each unit heat dissipating rib la that can be processed is [
8} From the formula, P2 = (upper ten ・) b ten (・- potato - 2 upper) t
Go.

Go○ten (2-亥)... [91 Therefore, it is much smaller than P in formula ■.

Another major feature of this invention is that, as mentioned above, both ends of the heat dissipation rib 1 are slanted to form the unit heat dissipation rib la, so that each unit shown in the above formula '9} It is possible to provide the heat radiation rib 1 having a pitch smaller than the lower limit value P2 of the pitch of the heat radiation rib la, and it is possible to extremely easily weld the heat radiation rib 1 and the welded part thereof. The object is to be able to provide a heat dissipation container. That is, as described with reference to FIG. 1, when constructing the frame by welding the upper side plate 5 and the lower side plate 6 having the bottom plate 8 to the aggregate 7, as shown in FIG. Then, the upper and lower parts of the bone village 7 are located inside the upper side plate 5 and the lower side plate 6, and a stepped diamond i is provided between the aggregate 7 and each of these side plates 5 and 6. By providing the step i, the structure is such that the oblique portions at both ends of the heat dissipation rib 1 are in close contact with the side plates 5 and 6, and the center portion (abdomen) of the heat dissipation rib is in close contact with the aggregate 7, respectively. Therefore, by setting the dimension of the step i to a value commensurate with the displacement h of the inclined portion of the heat radiation rib 1, the displacement h can be set to an arbitrary value. Therefore, each unit in the heat dissipation container with the above structure. The pitch P3 of the heat dissipation ribs la is t8} when the displacement amount is h.
From the formula, F3i(↓+・)b+(3-many)tgo○ 10(2-ne)y-2(★10,)b ,. Here, the displacement h, can take any value by adjusting with the step i, so the relationship h,>h is created between this displacement h, and h in equation (2). If so, side type P2 and dish type P3
A relationship of P2>P3 is established between each unit heat dissipation rib l.
The pitch of a is smaller.

Moreover, the pitch of the heat dissipation IJ can be set arbitrarily to some extent.
This makes it possible to provide the following information. Further, the displacement amount h, can be arbitrarily set from equation '8} within a range that satisfies the following.

In addition, in the case of the above structure, the extension 2 is from equations '3} and '6}, and if we substituting the la equation into equation 11 and sorting it out, we get
This proves that it is possible to process the heat dissipation ribs described above. In addition, the welding between the aggregate 7 and the upper side plate 5 and lower side plate 6 in the above structure is a fillet weld 11, as shown in FIG. Also has the advantage of providing sufficient welding strength.

In addition, since the welded portions between both ends of the heat dissipating lip and each of the side plates 5 and 6 are in line contact, the adhesion is good, making welding easier and significantly improving the oil-tight reliability. .

In addition, the above-mentioned aggregate 7 may be a part of the side plate which comprises a heat radiation container.

As described above, according to the present invention, the pitch of the unit heat dissipation ribs is 4 mm larger than that of the conventional one, and it is possible to provide heat dissipation ribs, thereby increasing the amount of heat dissipation from a transformer or the like.

Also, if the amount of heat dissipation is set equal to that of the subordinate,
It becomes possible to provide a heat dissipation container that is smaller than the secondary container. Furthermore, in terms of quality such as oil leakage, the welding length is shorter than that of a panel-type radiator, which improves the reliability of welding.

[Brief explanation of the drawing]

FIG. 1 is a side view of a heat dissipation container having heat dissipation ribs, FIG. 2 is a partial perspective view of the heat dissipation ribs, FIG. 3 is a partial sectional view of the heat dissipation ribs, and FIG. 4 is a partial side view of the heat dissipation ribs according to the present invention. 5 is a partial plan view of a heat dissipating IJ according to the present invention,
FIG. 6 is a partially enlarged view of the above plan view, FIG. 7 is a partial side view of the heat dissipation container according to the present invention, and FIG. 8 is a partial cross-sectional view of the heat dissipation container according to the present invention. 1... Heat radiation rib, la... Unit heat radiation rib, 5, 6.
... Side plate, 7... Aggregate. Younger brother' Figure 2 Figures 3 Figures 6 Figures 7 Figures 2 Figures

Claims (1)

[Claims] 1. A steel strip having a plurality of unit heat dissipating ribs formed in a bag shape by bending a steel strip into a wave shape and closing the opening ends located on both sides in the width direction in an oil-tight manner. ,
A heat dissipation container characterized in that unit heat dissipation ribs are bent along the protruding sides.