JP2006017392A - Duct for cooling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a duct for cooling capable of preventing the dropping of dew condensation water for a long period without attaching an urethane sponge to a surface. <P>SOLUTION: This duct for cooling 1 is composed of a plastic blow molding, has a number of V-shaped grooves 3 on its outer peripheral face, and has projections 4 corresponding to the grooves 3 on its inner peripheral face. The dew condensation water 6 attached to an outer peripheral face of a wall part 2 is held on bottom parts of the V-shaped grooves 3, and does not drop. The air flow near the wall part 2 stagnates by projections 4 at an inner peripheral face side of the wall part 2, and a layer of the air not so cold, is formed. As the increase of temperature difference between the wall part 2 and an outside air temperature is prevented by the air layer (in particular, a temperature of the outer peripheral face of the wall part 2 is close to the outside air temperature), the dew formation itself on the outer peripheral face of the wall part 2 is inhibited, and simultaneously the evaporation of the dew condensation water is promoted, thus the increase of attachment of the dew condensation water can be reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cooling duct used between an air conditioner and a cabin outlet for cooling a cabin of an automobile, a construction machine, an agricultural machine, or the like.

When the air conditioning machine is operated at a high temperature, condensed water adheres to the surface of the cooling duct, and this condensed water aggregates at the lowest point of the cooling duct due to gravity and drops and drops near the cooling duct. There is a problem in that it leaks into the interior, equipment, or cabin and wets the feet.
Therefore, conventionally, in order to absorb dew condensation water, suppress aggregation, and evaporate appropriately, urethane sponge is stuck on the outer surface of the cooling duct. However, the cost of the urethane sponge itself and the cost for application are high, and in the case of cooling ducts with complicated shapes such as curved or branched, it may be difficult to apply the same thickness on the surface. is there. Furthermore, when a cooling duct having a urethane sponge on the surface is assembled through a narrow passage, the urethane sponge may be peeled off or the urethane sponge may be crushed and the effect may be lost.
On the other hand, Patent Documents 1 and 2 below disclose means for preventing dripping of condensed water without adhering urethane sponge to the surface of the cooling duct.

Japanese Utility Model Publication No. 55-61009 JP 7-257149 A

Each of the means disclosed in Patent Documents 1 and 2 divides the surface of the cooling duct into a plurality of parts, suppresses aggregation by dispersing and holding the condensed water in each compartment, and prevents dripping of the condensed water. It is. However, in patent document 1, when the protrusion provided in the surface inclines with respect to a horizontal surface, or a centrifugal force acts on a vehicle, a water retention effect falls and it cannot prevent dripping of dew condensation water. Further, in Patent Document 2, the dew condensation water is stopped and held by the protrusions around the recesses, but the holding power is not sufficient, and it is inevitable that the dew condensation water accumulates and drops over time. .
Accordingly, an object of the present invention is to obtain a cooling duct that can prevent dripping over a long period of time in a cooling duct that can hold condensed water on the outer surface of the duct without attaching urethane sponge to the surface. To do.

In order to prevent the condensation from dripping for a longer time, it is effective to increase the retention of condensation on the surface of the cooling duct and at the same time reduce the condensation itself to prevent the condensation from accumulating on the duct surface. is there.
The cooling duct according to the present invention is based on this concept, and is made of a plastic blow molded body. A plurality of grooves having a V-shaped cross section are formed on the outer peripheral surface, and a protrusion corresponding to the groove on the inner peripheral surface. And the dew condensation water is held at the bottom of the groove. It is desirable that the protrusions intersect with the air flow direction in the duct. Moreover, it is desirable that the cooling duct is made of a foamed blow-molded body containing a large number of closed cells.

In the cooling duct according to the present invention, a plurality of V-shaped grooves are formed on the outer peripheral surface of the duct wall portion, and the dew condensation water is narrowed into a V-shaped groove on the outer peripheral surface due to capillary action due to surface tension. Gathered and retained.
On the other hand, since the cooling duct according to the present invention is a blow-molded body, protrusions corresponding to the grooves are formed inside the duct. The ridge stagnates the air flow in the vicinity of the duct wall, and the temperature of the air in the vicinity of the duct wall becomes higher than the inside of the duct. Therefore, the temperature difference between the temperature of the duct wall and the temperature around the duct (temperature) (Gradient) does not increase, and as a result, condensation is reduced and at the same time evaporation of the condensed water is promoted. Thereby, it can suppress that dew condensation water accumulates on the duct surface.
Due to both of these actions, the cooling duct according to the present invention can prevent dripping of condensed water over a long period of time, and can also prevent dripping at all within a practical continuous operation time.

The cooling duct according to the present invention will be specifically described below with reference to FIGS.
The cooling duct 1 shown in FIGS. 1 and 2 is made of a blow molded body of plastic such as polyethylene or polypropylene, and a continuous groove 3 having a V-shaped cross section is formed on the outer peripheral surface of the wall portion 2 in the length direction of the duct (duct A large number of the ducts are formed at equal intervals over almost the entire length of the duct perpendicular to the air flow direction. In this cooling duct 1, the grooves 3 are formed in the straight portion of the duct, and each groove 3 surrounds the outer peripheral surface of the wall portion 2 in a ring shape. Since the cooling duct 1 is made of a blow molded body, as shown in FIG. 2, a protrusion 4 corresponding to the groove 3 is formed inside the duct.

When the air-conditioning machine is operated and the cooled air is circulated through the cooling duct 1 (see arrow 5 in FIG. 2), the wall portion 2 is cooled and condensed water adheres to the outer peripheral surface thereof. The adhering condensed water aggregates at the bottom of the groove 3 narrowed in a V shape and is retained by capillary action due to surface tension (condensed water retained in the groove is indicated by numeral 6).
On the other hand, when the inner peripheral surface side of the cooling duct 1 is viewed, since the protrusion 4 protrudes inward in the vicinity of the wall portion 2, the air flow is stagnant, and in this case, the cooled air flowing through the duct is cooled. As a result, a temperature layer is formed between the cooled air flowing inside the duct and the wall 2 that is not so cool. The cooling of the wall 2 is suppressed by this air layer, and the temperature difference (temperature gradient) between the temperature of the wall 2 and the temperature around the duct is not so large (particularly, the outer peripheral surface of the wall 2 is close to the outside temperature). In addition, the condensation itself on the outer peripheral surface of the wall 2 is suppressed, and at the same time, the evaporation of the condensed water is promoted.

In this cooling duct 1, the direction of the ridge 4 intersects the direction of air flow inside the duct. The function of holding the condensed water at the bottom of the V-shaped groove 3 is not directly related to the direction of the ridge 4, but the effect of suppressing the amount of condensed water adhering is that the direction of the ridge 4 is inside the duct. It becomes stronger when it intersects with the air flow direction.
The angle θ, the width W, the depth D, and the mutual distance P (see FIG. 2) of the V-shaped groove 3 are generally θ: 45 to 120 °, W: 1 to 7 mm, D: 1 to 5 mm. , P: It may be appropriately selected from the range of 3 to 15 mm.

  The cooling duct 11 shown in FIG. 3 is also made of a plastic blow-molded body, and an intermittent groove 13 having a V-shaped cross section is formed substantially along the length direction of the duct on the outer peripheral surface of the wall portion 12. Many are formed over the entire length. Although the cross section of the groove 13 is not shown, it has substantially the same cross sectional structure as the groove 3 shown in FIG. The cooling duct 11 is arranged in a curved portion of the duct, and the groove 13 is mixed with one that is parallel to the direction in which the air flows in the duct. In the cooling duct 11, as in the cooling duct 1, a continuous groove in a ring shape perpendicular to the air flow direction may be formed.

The cooling duct 21 (only the cross section) shown in FIG. 4 is also made of a plastic blow molded body, but differs from the cooling duct 1 in that it contains a large number of closed cells 26. Since the outer peripheral surface of the blow molded body is in close contact with the mold at the time of manufacture, the outer peripheral surface of the wall portion 22 has a textured surface asperity, while the inner peripheral surface is relatively uneven due to the closed cells 26.
Since the wall portion 22 contains a large number of closed cells 26, the cooling duct 21 is excellent in heat insulation, and the stagnation of the air flow in the vicinity of the wall portion 22 becomes stronger due to the unevenness of the inner peripheral surface. As a result, the temperature difference (temperature gradient) between the temperature of the wall portion 22 and the air temperature around the duct does not increase, the outer peripheral surface of the wall portion 22 becomes closer to the outside air temperature, and the amount of condensed water attached is further suppressed. Is done.

1 is a perspective view of a cooling duct according to the present invention. It is the AA sectional view. It is a perspective view of another cooling duct according to the present invention. It is sectional drawing of the another cooling duct which concerns on this invention.

Explanation of symbols

1,11,21 Air conditioning duct
2,22 Wall 3,13,23 V-shaped groove 4,24 Projection 6 Condensation water 26 Closed cell

Claims (3)

It is made of a plastic blow molded body, a plurality of grooves having a V-shaped cross section are formed on the outer peripheral surface, and a protrusion corresponding to the groove is formed on the inner peripheral surface, so that condensed water is held at the bottom of the groove. A duct for cooling. The cooling duct according to claim 1, wherein the protrusion intersects the air flow direction in the duct. The cooling duct according to claim 1 or 2, comprising a foamed blow molded article containing a large number of closed cells.

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