JPH08285485A - Automobile radiator tube - Google Patents

Abstract

PURPOSE: To improve heat exchange efficiency and miniaturize a radiator tube. CONSTITUTION: A radiator includes an upper tank 2 and a lower tank 3, and the upper tank 2 and the lower tank 3 are communicated with each other through a plurality of radiator tubes 5. A spiral groove 9 is formed in an internal peripheral surface 5a of each radiator tube 5. In the radiator, cooling water that cools an engine is stored in the upper tank 2 and is introduced to flow down spirally turning along the groove 9 in the radiator tube 5 and is introduced into the lower tank 3. The cooling water is cooled by exchanging heat with cooling air from a cooling fan when it flows down in the radiator tube 5. Upon the cooling the cooling water is directed to flow down alternately along an upstream side and a downstream side of the cooling air while turning in the radiator tube 5, so that water temperature at each cross section of the cool ing water flowing in the radiator tube 5 can be kept unchanged for improvement of heat exchange efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile radiator.

[0002]

2. Description of the Related Art Conventionally, a radiator for an automobile has a structure in which a radiator core is arranged between an upper tank and a lower tank. The radiator core is composed of a radiator tube and cooling fins attached to the tube. The radiator tube has an upper end communicating with the upper tank and a lower end communicating with the lower tank. And
The cooling water heated by the engine is introduced into the upper tank and then sent to the lower tank through the radiator tube. During this time, the cooled cooling water is supplied from the lower tank to the engine to cool the engine.

Further, in recent years, miniaturization of various equipments has been demanded in automobiles, and further miniaturization of radiators is also desired.

[0004]

By the way, as shown in FIG. 6, the cooling water flowing in the radiator tube 51 toward the lower tank flows uniformly. That is, the radiator tube 51 is always blown with the wind from one fixed direction.

Therefore, the portion directly contacting the tube 51
Outside air temperature (upwind point K1), that is, windward outside air temperature T
_A1Is the part on the opposite side (wind
Outside temperature of lower point K2), that is, leeward outside temperature T_A2Lower
It becomes. This is because the air hitting the tube 51 does not exchange heat.
It moves to the other side while being exchanged, so it is warmed up in the meantime
This is because that. As a result, the cold that flows on the side where the wind directly hits
Return water temperature, windward water temperature T_W1The other side that does not hit directly
Temperature of cooling water flowing through the water, lee water temperature T_W2Will be lower. This
At the time of, the windward outside temperature T_A1And windward water temperature
T_W1Temperature difference with (= T _W1-T_A1) Is big, but hits directly
Lee temperature T on the opposite side_A2And leeward water temperature
T_W2Difference with (= T_W2-T_A2) Is small.

Here, the small temperature difference means that the heat exchange rate is small. Therefore, if a portion where the temperature difference is small occurs in a certain portion, the total amount of heat exchange is reduced. That is, this total heat exchange amount is represented by the area S surrounded by the outside air temperature and the cooling water temperature in FIG.

Therefore, in order to increase the heat exchange rate,
It is conceivable to increase the size of the radiator, but there was a limit to increasing the size in automobiles where the installation space is tight. The present invention has been made to solve the above problems, and an object of the present invention is to provide a radiator tube for an automobile, which can improve the heat exchange rate and can further reduce the size of the radiator.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 is a radiator tube for an automobile, in which cooling water for cooling an engine is passed and cooled by heat exchange action. The gist of the invention is that a turning guide is formed on the inner peripheral surface.

The invention according to claim 2 is, in the invention according to claim 1, characterized in that the swirl guide portion is a groove formed in a spiral shape on the inner peripheral surface of the tube. Claim 3
The gist of the invention described in claim 1 is that in the invention described in claim 1, the swirl guide is a ridge formed obliquely on the inner peripheral surface of the tube.

[0010]

Therefore, according to the first aspect of the present invention, the turning guide portion is formed in the radiator tube. Cooling water flowing in the radiator tube is agitated by the swirl guide. Therefore, for example, when cooling the cooling water by sending air to the radiator tube, the cooling water flowing in the radiator tube passes through the windward side and the leeward side while being stirred with a substantially equal ratio. Therefore, the temperature distribution of the water temperature from the leeward side to the leeward side of the cooling water flowing through the radiator tube becomes substantially uniform.

According to the second aspect of the present invention, the cooling water flowing in the radiator tube is agitated by the groove formed in a spiral shape. According to the third aspect of the present invention, the cooling water flowing in the radiator tube is agitated by the obliquely formed ridges.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
It will be described with reference to FIG. FIG. 3 is a perspective view showing an outline of the radiator 1, and FIG. 4 is a schematic view schematically showing a flow of cooling water in the radiator 1.

The vehicle is provided with a radiator 1 for cooling the engine. An upper tank 2 is provided above the radiator 1, and a lower tank 3 is provided below the upper tank 2. A radiator core 4 is arranged between the upper tank 2 and the lower tank 3. The radiator core 4 is composed of a plurality of radiator tubes 5 and cooling fins 6 arranged between the radiator tubes 5. The upper tank 2 is communicated with the upper end of the radiator tube 5, and the lower tank 3 is communicated with the lower end of the radiator tube 5. That is, the upper tank 2 and the lower tank 3 are communicated with each other by the radiator tube 5.

A first introduction tube 7 is communicated with the upper tank 2, and cooling water from the engine is supplied to the first introduction tube 7.
Is introduced into the upper tank 2 via. The lower tank 3 is communicated with the second introduction tube 8, and the cooling water in the lower tank 3 is introduced into the engine through the second introduction tube 8.

Further, a cooling fan (not shown) is provided on one side of the radiator 1, and the cooling fan is used to drive the radiator 1 as shown in FIG.
Cooling air is blown in the direction indicated by arrow X in FIG. That is, the side of the radiator tube 5 where the cooling fan is installed is the leeward side, and the side opposite to the side where the cooling fan is installed is the leeward side.

FIG. 1 is a partially cutaway perspective view showing the inside of the radiator tube 5. The radiator tube 5 is formed in a hollow shape with both ends open, and its cross-sectional shape is formed into an oval shape. That is, the inner peripheral surface 5a of the radiator tube 5 includes two inner flat surface portions 5b provided in parallel at positions facing each other, and a semicircular portion 5c positioned so as to face each other at an end portion of each inner flat surface portion 5b. It consists of

On this inner peripheral surface 5a, one spiral groove portion 9 is formed as a turning guide portion. The groove 9 has a U-shaped cross section, and is formed in a spiral shape over the entire length of the radiator tube 5 from the upper end to the lower end. The depth and width of the groove 9 are the same in all parts.

Next, the radiator 1 constructed as described above.
The operation and effect of the radiator tube 5 will be described. Normally, when the engine is started, the radiator 1 is driven and the cooling fan is rotated, so that cooling air is blown to the radiator tube 5. Then, the cooling water that is heated by cooling the engine is introduced into the upper tank 2 through the first introduction tube 7. This cooling water is introduced from the upper tank 2 into the radiator tube 5, and flows down in the radiator tube 5 from above to below.

When the cooling water flows down in the radiator tube 5, the heat of the cooling water is transferred to the radiator tube 5, and the heat transferred to the radiator tube 5 is absorbed by the cooling air. In this way, the cooling water flowing in the radiator tube 5 is cooled by exchanging heat with the cooling air via the radiator tube 5. The cooling water cooled by this heat exchange action is introduced into the engine from the lower tank 3 through the second introduction tube 8.

The cooling water flowing down in the radiator tube 5 spirally swirls along the groove 9 and flows down from the upper side to the lower side. In this case, the swirling degree becomes stronger as the cooling water flowing near the inner peripheral surface 5a of the radiator tube 5, and the swirling degree becomes weaker as the cooling water flowing near the central portion. That is, while the cooling water flowing near the inner peripheral surface 5a spirally swirls, the cooling water alternately flows down the windward side and the leeward side of the cooling air, and the cooling water flowing near the central portion does not swirl but directly moves downward from above. Flows down.

FIG. 2 thus shows the radiator tube 5
The temperature distribution of the water temperature T _W of the cooling water flowing down inside and the outside air temperature T _A of the cooling air for cooling the cooling water is shown.
The temperature distributions of the water temperature T _W and the outside air temperature T _A shown in this figure are from the leeward point K1 to the leeward point K1 in one cross section (Y-Y cross section in FIG. 1) located near the lower end of the radiator tube 5.
2 is a temperature distribution to 2.

Normally, as for the outside air temperature T _A around the radiator tube 5, the leeward outside air temperature T _A2 at the leeward point K2 is higher than the leeward outside air temperature T _A1 at the upwind point K1. The temperature increases as much as the heat is absorbed, and the heat exchange rate decreases as the heat is absorbed from the windward side to the leeward side.

In this state, the cooling water flowing near the inner peripheral surface 5a alternately turns between the upwind point K1 having a high heat exchange rate and the leeward point K2 having a low heat exchange rate. Therefore, the water temperature T _W of the cooling water flowing through the cross section is substantially constant. That is, in the same cross section, the water temperature at the upwind point K1 (hereinafter referred to as "windward water temperature") T _W1 and the water temperature at the leeward point K2 (hereinafter referred to as "leeward water temperature") T _W2 are substantially the same. It becomes temperature.

The cooling water flowing near the central portion has a heat exchange rate near the central portion thereof, that is, a heat exchange rate at a value substantially intermediate between the heat exchange rate at the upwind point K1 and the heat exchange rate at the leeward point K2. Cooled at a rate. Therefore, the water temperature T _W of the cooling water flowing in the vicinity of the center portion is substantially the same temperature and the water temperature T _W flowing near the inner peripheral surface 5a.

Therefore, the amount of heat exchanged at each position from the upwind point K1 side toward the leeward point K2 side is the same. Therefore, the temperature gradient of the outside air temperature T _A is
Get loose.

Therefore, according to this embodiment, since the groove portion 9 is formed on the inner peripheral surface 5a of the radiator tube 5 as the swirl guide portion, the surface area of the radiator tube 5 corresponding to the groove portion 9, that is, the heat exchange surface area. Can be increased. By increasing the heat exchange surface area, the heat exchange rate by the radiator tube 5 can be improved, and while the cooling water flows down from the upper end to the lower end of the radiator tube 5, the heat exchange amount exchanged with the cooling water is increased. it can. Moreover, since the turning guide portion is the groove portion 9, it can be easily formed by notching the inner peripheral surface 5a of the radiator tube 5, for example.

Further, since the groove portion 9 is formed in a spiral shape, the cooling water whirls in the radiator tube 5 and alternately flows down from the upper side to the lower side on the windward point K1 side and the leeward point K2 side. The water temperature T _W in each cross section of the cooling water flowing in 5 can be made uniform. Therefore, as compared with the case where the leeward water temperature T _W2 is higher than the leeward water temperature T _W1 as in the conventional case, the temperature gradient of the outside air temperature T _A can be made gentle, so that the heat exchange rate particularly on the leeward point K2 side can be improved. Therefore, the heat exchange amount of the radiator tube 5 can be increased.

By increasing the amount of heat exchange in this way, the radiator 1 itself can be miniaturized as compared with the conventional radiator tube 51 in which the groove 9 is not formed. For example, shorten the length of the radiator tube 5,
By reducing the diameter of the radiator tube 5 or reducing the number of radiator tubes 5, the radiator 1
The size of itself can be reduced.

Further, according to this embodiment, in order to keep the temperature of the cooling water constant, the structure is such that the upwind point K1 and the leeward point K2 are alternately turned, so that the entire cooling water is agitated. When the temperature is kept constant, a member having a necessary large resistance is not required. Therefore, it is less likely that bubbles will be generated in the cooling water flowing through the radiator tube 51.

The present invention is not limited to the above-mentioned embodiments, and may be appropriately modified and carried out without departing from the spirit of the invention. (1) In the above embodiment, the groove 9 is formed deeper,
By making the swirling force of the cooling water flowing through the radiator tube 5 stronger, not only the cooling water near the inner peripheral surface 5a but also the cooling water near the center may be swirled.

(2) In the above embodiment, the number of the groove portions 9 is not limited to one and may be plural. In this case, the cooling water is agitated along the plurality of groove portions 9, so that the cooling water can be agitated more reliably.

(3) In the above embodiment, as shown in FIG. 5, a plurality of slanted protrusions 21 may be formed on both inner flat surfaces 5b of the radiator tube 5 as turning guides. The ridges 21 formed on the inner flat surfaces 5b are alternately arranged at predetermined intervals in the vertical direction. Then, the cooling water flowing in the radiator tube 5 is agitated by these ridges 21 as in the case of the groove portion 9. In this case, the ridge 21 projects inward from the inner peripheral surface 5a. Therefore, the ridges 21 can surely contact and guide the cooling water flowing in the radiator tube 5. Therefore, the cooling water in the radiator tube 5 can be agitated by reliably swirling the cooling water. Further, since each of the ridges 21 is formed in a linear slant shape, it can be easily formed.

Further, the protrusion may be formed in a spiral shape as the turning guide portion. Further, the groove 9 may be formed in an inclined shape. (4) In the above embodiment, a cooling fan (not shown)
May be on the leeward side instead of the leeward side. That is, the radiator 1 can also be applied to a suction fan.

(5) In the above embodiment, the cross-sectional shape of the groove 9 is not limited to the U-shape, but for example,
It may be triangular or semicircular. Similarly, the cross-sectional shape of the protrusion 21 shown in FIG. 5 is not limited.

The technical ideas other than the claims that can be understood from the above-described embodiments will be described below along with their effects. (1) In the invention according to claim 1, a radiator tube for an automobile in which the turning guide portion is formed in a spiral shape. According to this radiator tube, the cooling water can be easily stirred while swirling.

[0036]

As described in detail above, according to the first aspect of the present invention, the cooling water flowing in the radiator tube is agitated by the swirling guide portion, so that the cooling water flowing in the same cross section of the radiator tube. The water temperature can be made uniform and the heat exchange rate can be improved. According to the invention described in claim 2, since the swirl guide portion is a spiral groove portion, the swirl guide portion can be easily formed, and the cooling water spirally swirls in the radiator tube, so that the stirring can be surely stirred. According to the third aspect of the invention, since the swirl guide is a slanted protrusion, the cooling water flowing in the radiator tube can surely touch the protrusion, and the protrusion can surely stir the cooling water.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a radiator tube.

FIG. 2 is a cross-sectional view of a radiator tube and an explanatory view showing a temperature distribution of cooling water temperature and outside air temperature in the cross section.

FIG. 3 is a perspective view showing a radiator.

FIG. 4 is a schematic diagram schematically showing a flow of cooling water in a radiator.

FIG. 5 is a partially cutaway perspective view showing a radiator tube of another example.

FIG. 6 is a partially cutaway perspective view of a radiator tube in a conventional example, and an explanatory view showing a temperature distribution of cooling water temperature and outside air temperature in a cross section thereof.

[Explanation of symbols]

5 ... Radiator tube, 5a ... Inner peripheral surface as tube inner peripheral surface, 9 ... Groove portion as turning guide portion, 21 ...

Claims (3)

[Claims] 1. A cooling water for cooling an engine is passed through,
A radiator tube for an automobile, which is cooled by heat exchange action, wherein a turning guide portion is formed on the inner peripheral surface of the tube. 2. The radiator tube for an automobile according to claim 1, wherein the turning guide portion is a groove formed in a spiral shape on an inner peripheral surface of the tube. 3. The radiator tube for an automobile according to claim 1, wherein the turning guide portion is a ridge formed obliquely on an inner peripheral surface of the tube.