JPS61153393A - Plate fin type radiator core for automobile - Google Patents

Abstract

PURPOSE:To enable to miniaturize a core without lowering the efficiency based upon the quantity of radiating heat, draft resistance and the like by a structure wherein tubes are arranged in zigzags and the width of a core and the diameter of a tube are respectively set to specified dimensions. CONSTITUTION:Because the quantity of radiating heat of a radiator is determined by the rating of a radiator itself, draft resistance, the quantity of circulating water, the combination of limits to satisfy with the necessary quantity of radiating heat is set. In addition, the temperature in an engine room has a certain upper limit restricted by the durability of parts in the room. The lowest air speed passing through the radiator and the maximum draft resistance are determined by the above-mentiond necessary quantity of radiating heat and the limiting temperature of the engine chamber. The calculation based upon the elements just mentioned above shows the acceptable region restricted by the necessary quantity of radiating heat of 24mm or more in core width and 8mm or less in tube diameter and that restricted by the coefficient of resistance of the radiator of 28mm or less in core width and 7mm or less in tube diameter. Further, the lowering of pressure is produced by being restricted by the requirement of the flow rate on the water side, when the tube diameter is 6mm or less. Consequently, the optimum form of the radiator core is of 24-28mm is core width and 6-7mm in tube diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a plate-fin type radiator core for automobiles in which round tubes are arranged in a staggered manner.

(0) Technology background Recently, automobile radiators have been used to reduce the weight of automobiles.

In response to demands for lower fuel consumption, they are being made of synthetic resin and becoming smaller.

A plate-fin type radiator is an excellent radiator that satisfies such requirements.

In addition, for a small car, the speed is, for example, 60 km/hr.

There is a need for a radiator that can function even under severe conditions such as driving on a single hill.

Q3 Conventional technology and problems Conventionally, this type of plate-fin type radiator:
For example, it is known from Japanese Utility Model Application Publication No. 58-194386.

However, all of these plate fin type radiators have features regarding the arrangement of tubes and louvers or the shape of the louvers, and are not designed to reduce the size of the radiator core. Therefore, it has not been possible to fully satisfy the demand for providing a radiator that can respond to the above-mentioned reduction in weight and size of automobiles.

Purpose of the invention The present invention has been made in view of the above problems,
The purpose is to downsize the plate-fin type radiator core.

(E) Structure of the Invention In order to achieve the above object, the present invention provides cylindrical burring holes in a staggered manner, and a plurality of plate fins with parallel louvers provided between the burring holes are arranged in parallel. In the plate fin type radiator core for automobiles, which is made by inserting a round tube into the burring hole and expanding the tube, the core width is 24 to 28 mm and the tube diameter is 6 to 7 mmφ.
The configuration is as follows.

(f) Examples of the invention Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a plan view showing a radiator core according to the present invention, and Fig. 2 is a side view thereof. burring hole, 3 is the above plate fin l
A parallel louver 4 provided in the burring hole 2 is a round tube inserted into the burring hole 2.

A radiator core X is formed by inserting a round tube 4 into each burring hole 2 of the plate fin 1 and expanding the tube.

The core diameter Y of the radiator core X and the diameter Z of the round tube 4 are as follows:
= 6 to 7 mmφ.

The heat dissipation amount of the radiator is the capacity of the radiator shoulder.

Ventilation resistance is determined by the amount of water flowing through one unit. Therefore, it is necessary to set a limit combination that satisfies the required amount of heat radiation.

Furthermore, the temperature in the engine room cannot be raised above a certain limit due to the durability of the parts in the engine room.

From these required heat dissipation amount (QE) and engine room limit temperature (THmax), the minimum passing wind speed (Va min)
and the maximum airflow resistance (ΔPa max ) of the radiator is determined.

Here, if the engine calorific value is QE and the engine room temperature is TE, then TE=Ta2+α. In the above formula, Ta1 is the air temperature on the radiator inlet side, Ta2 is the air temperature on the radiator outlet side, α is the engine radiant heat, Va is the passing wind speed, Ta is the air specific gravity, Cpa is the air specific heat, and A is the radiator front surface area.

From Figure 3, the limit value of engine room temperature (TEmax
) In order to maintain the following, the ventilation speed must be ensured to be equal to or higher than Vamin.

Further, when the ventilation rate of the vehicle is ψ, the resistance ΔPac of the vehicle is generally ΔPac = −9Va 2CDc. In the above formula, CDc is the ventilation system resistance coefficient (excluding the radiator), ρ is the air density, and Va is the passing wind speed. Here, the air density ρ is "kg-3ec".

The maximum resistance coefficient of the radiator (:, DRmax is denoted by .

Therefore, the resistance coefficient of the radiator must be kept below CD RmaX.

For example, in the case of current small vehicles, the ventilation rate ψ = 15% (0
, 15), air density ρ = 0.119, required heat dissipation QE when pitching = approximately 25.600 kcal/h, then C
D.

ψ and ΔPa are as follows.

ΔPa = -p Va 2CD = knee xo, 119 x2.512x43.4 = 16.
3mmAqHere, since the vehicle resistance coefficient is approximately 28.5, the radiator resistance coefficient is: CD R= CD -28,5=43.4-28.5=
14.9,. ΔPa=□ρVa 2CDR.

Therefore, the upper limit value CD Rmax of the radiator resistance coefficient is 14.9.

The region that satisfies the required heat dissipation amount and radiator resistance coefficient with the inside of the core as a variable element is shown in FIG. 5.

Due to the required amount of heat dissipation, the core should be 24 mm or more, and the tube diameter should be 8 mm.
φ or less is OK area from the radiator resistance coefficient to 28 in the core
mm or less, and a tube diameter of 7 mmφ or less is an OK region.

Therefore, the radiator shape that satisfies both is
:24-28m+s Tube diameter: 7mm φ or less.

Further, the flow rate on the water side is determined by the water flow resistance of the radiator, and is as shown in FIG. 6 based on the pump characteristics of a small car.

Therefore, if the tube diameter is 6 mm or less, the water flow rate will be significantly reduced, and the effectiveness will be reduced.

Based on the above, the optimal shape of the plate type radiator core under the actual driving conditions of the vehicle is: ・Medium core: 24~28mm ・Tube diameter: 6~7m1IIφ ・Rouhani parallel louver (optimum heat dissipation amount, low illumination resistance) ・Tube arrangement: Chidori arrangement (1. For manufacturing purposes, it is unbeatable to have the core in a normal arrangement. 2. Fin efficiency (determined from the advantage of improving heat conduction efficiency at the rear of the tube, etc.) .

The plate-fin type radiator constructed in this way can function satisfactorily even under the severe conditions of 60 km/hr uphill running.

(G) As described in detail, according to the present invention, the tube arrangement is staggered, the core is 24 to 28 mm, and the tube diameter is 6 to 6 mm.
Since the diameter of the radiator is 7mmφ, the heat dissipation amount of the radiator is 9
This makes it possible to easily provide a radiator without reducing efficiency due to ventilation resistance or the like and without causing problems in manufacturing.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the present invention, Fig. 2 is a side view thereof, Fig. 3 is a graph showing the relationship between passing wind speed and engine room temperature, and Fig. 4 is a graph showing the relationship between passing wind speed and air resistance. FIG. 5 is a graph showing the area that satisfies the required heat dissipation amount and radiator resistance coefficient, and FIG. 6 is a graph showing the relationship between water flow resistance, actual vehicle flow rate, and tube diameter. 1... Plate fin, 2... Burring hole, 3...
...Parallel louver, 4...Round tube, X...Radiator core, Y...Medium core, Z...Round tube diameter.

Claims (1)

[Claims] For automobiles, cylindrical burring holes are provided in a staggered manner, a plurality of plate fins with parallel louvers are arranged in parallel between the burring holes, and a round tube is inserted into the burring holes to expand the tube. A plate fin type radiator core for an automobile, characterized in that the core width is 24 to 28 mm and the tube diameter is 6 to 7 mmφ.