JPH086713B2 - Radiator fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fan for an automobile radiator,
It is applied to the radiator with large ventilation resistance.

[Prior art]

Since various devices are installed inside the engine room of the automobile, the ventilation of the radiator is poor. Moreover, in many cases, the radiator for engine cooling, the radiator for intercooler, and the radiator for indoor air conditioning are installed so as to overlap each other. Then, the ventilation resistance of them as a whole tends to become worse. Therefore, the conventional axial fan may not be able to sufficiently cool the radiator.

A fan with high static pressure is known as a fan for ensuring a sufficient air volume for a radiator having such a large ventilation resistance. That is, the boss portion has a truncated cone shape, and a plurality of blade portions are arranged on the outer periphery of the boss portion at equal intervals, and the tip end edge in the radial direction of the blade portion is formed parallel to the axis of the boss portion.

This fan is a high static pressure fan that works in the pressure coefficient range of 0.20 to 0.35. A fan clutch is generally mounted in the boss portion of this radiator fan, and for that purpose, it is necessary to secure a sufficient space for mounting the fan clutch in the boss portion of the fan and to improve the fan efficiency. It has been experimentally confirmed that the ratio of the boss portion to the blade portion is the following value from the viewpoint of ensuring the sufficient amount. That is, the ratio of the tip radius of the wing portion to the radius at the central root portion of the front and rear edges of the wing portion is about 0.35 to 0.55.

In addition, since the boss portion of such a high static pressure fan has a truncated cone shape, when the airflow flowing from the front edge of the blade of the fan flows out rearward from the rear edge, the airflow is discharged in a mixed flow direction. It At this time, when the fan shroud that fits the outer periphery of the fan is fitted over the entire fan, it is preferable that the fan shroud is not fitted on the rear end edge of the blade of the fan because it impairs ventilation. . According to the experiments conducted by the present inventor, it was found that the fan static shroud fitting ratio of the high static pressure fan is preferably about 0.6 to 0.8.

[Problems to be solved]

The radiator fan as described above is characterized in that the ventilation amount is large even for a radiator having a large ventilation resistance. However, in such a high static pressure fan having a truncated cone-shaped boss, the correlation between the inclination angle of the boss and the width of the blades and the like is obtained as a condition that the power consumption is low and the air volume is large. Was previously unknown.

It is expected that there is a close relationship between the inclination angle θ of the outer periphery of the boss portion of the fan and the fitting ratio S / T with which the fan shroud described later fits the outer periphery of the blade portion. However, their relationship was unknown. That is, the relationship between S / T, boss inclination angle θ, blade width T, and blade average length B was comprehensively obtained, and a fan with a large air volume and high fan efficiency was obtained. Has never existed.

[Means for solving the problem]

Therefore, as a result of various experiments, the present inventor has devised a fan that solves the above problems. The configuration is as follows.
That is, the pressure coefficient Ψ = 0.20 to 0.35, the boss portion 1 has a truncated cone shape, and a plurality of blade portions 2 are arranged on the outer periphery of the boss portion 1 at equal intervals. It is formed parallel to the axis of the boss portion 1, and the relation between the radius R ₀ of the tip of the blade portion 2 and the radius Rb of the center of the front and rear edges of the blade portion is Rb / R _0.
= X = 0.35 to 0.55, and the tubular portion 3 of the shroud is fitted by the axial length S so that the rear end portion of the tip edge is exposed in the vicinity of the tip edge of the blade portion 2, In a radiator fan whose fitting ratio is S / T = 0.6 to 0.8 with respect to the blade width T, the height B of the central blade after the leading edge is B = R ₀ −Rb.
When the difference between the radius of the leading edge and the radius of the trailing edge at the root of the wing portion 2 is F, there is a relationship of F / B = 0.25 to 0.45 and the root of the trailing edge of the wing portion 2 is When an imaginary line 1 orthogonal to the outer surface of the boss portion 1 is projected on the wing portion 2, the intersection of the imaginary line 1 and the leading edge of the wing portion 2 and the rear end edge of the wing portion 2 are projected. A fan for a radiator characterized in that the distance D to the blade width T is D / T = 0.35 to 1.1.

However, the pressure coefficient Ψ shows the operating point of the fan, and shows the intersection of the pressure coefficient curves of the fan and the radiator with the flow coefficient Φ as the horizontal axis.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic axial cross-sectional view showing a usage state of the radiator fan, FIG. 2 shows a main part thereof, and FIG. 3 is a front view of the fan.

In this radiator fan, the boss portion 1 is formed in a truncated cone shape, and the blade portions 2 are arranged at equal intervals on the outer peripheral surface thereof. And the central part of the boss part 1 has a large opening,
An annular mounting surface 7 is integrally fixed to the boss portion 1 at its inner peripheral edge. This fan is made of synthetic resin,
There is a slight gap between each of the wings 2, 2 so that the molding is easy. Further, the root of the wing 2 is attached at a predetermined angle with respect to the axis of the boss 1, and the wing 2 itself is slightly twisted as it goes from the root to its tip edge. . These twist angles are smaller than those of conventional axial fans. The front edge 12 of the wing portion 2 has a boss portion 1 as shown in FIGS.
Is raised slightly rearward from the front end of
It coincides with the front end of the boss 1. Next, the leading edge 11 of the wing 2
Is formed parallel to the axis, and the rear end edge 13 coincides with the rear end of the boss portion 1. And the tip radius of the wing portion 2
The ratio of R ₀ to the radius Rb at the center root of its front and rear edges is 0.
About 35 to 0.55 is preferable. This is a practical value that satisfies both of mounting the fan clutch in the boss portion of the fan and improving the fan efficiency. That is, when this value exceeds 0.55, the cross-sectional area of the air escape on the outlet side of the fan becomes too small, impairing the ventilation and, as a result, reducing the ventilation volume of the radiator. On the other hand, if it is less than 0.35, the boss portion becomes too small, and it becomes impossible to mount the required fan clutch.

Next, the cylindrical portion 3 of the shroud is fitted so as to face the tip edge 11 of the wing portion 2. The tubular portion 3 is connected to the shroud body 14 via an annular rubber plate 6, and the open end of the shroud body 14 is fixed to the tank 5. In addition, the tubular portion 3 is a stay 10.
It is fixed to the engine 9 via. The flange portion of the clutch 8 is fixed to the mounting surface 7 of the boss portion 1. The drive side shaft of the clutch 8 is connected to the crankshaft of the engine 9 via a gear or the like. The shroud tubular portion 3 is formed so that only the middle portion and the front end portion of the blade portion 2 are fitted and the rear end portion is exposed. This is to secure a sufficient cross section of the outlet of the fan and to increase the ventilation volume.
The fitting length of the tubular portion 3 with respect to the S / T was set in the range of 0.6 to 0.8. The average value of the best value is 0.7 as a result of experimenting with each of the seven types of prototype fans described below.
This is because it was found that the air volume and pressure coefficient increased between 0.6 and 0.8.

Next, this fan is a high static pressure fan that works with a pressure coefficient Ψ of 0.20 to 0.35. In such a fan, when the difference between the radius of the leading edge and the radius of the trailing edge at the root of the blade portion 2 is F and the height of the blade at the center of the front and rear edges is B, the value of F / B, Second
Ratio of blade thickness T to blade tip length D in the figure D / T
It has been found that the value of has a great influence on the flow coefficient and efficiency. This is because if the F / B is large, the outlet will be throttled and the air will not escape easily, and if the F / B is small, the diagonal flow effect of air flowing diagonally will not be sufficiently obtained, making it unsuitable as a high static pressure fan. is there. Also, if the D / T is too large, the demand for the mixed flow effect is too urgent, so the expected flow cannot be obtained, and if the D / T is too small, the duct thickness ( It was found that the wing width) increased and was not practical. Therefore, as a result of confirming these elements by experiments, the F / B is 0.25 to 0.4.
In 5, it became clear that the D / T should be 0.35 to 1.1.

[Experiment]

Two types of fans having different outer diameters, inclination angles of bosses, and the like shown in FIGS. 2 and 3 were manufactured, and the pressure coefficient Ψ and the efficiency η with respect to the flow coefficient Φ were measured for each fan. . The seven types of fans used in this experiment are shown in the following table.

That is, there are three types of fans A _{1 to} A ₃ whose outer radius is 215 mm, whose blade width is 85 mm, and whose boss angles are 20 °, 30 °, and 37.5 °, respectively.
And the outer radius of the wing is 240 mm, the wing width is 79 mm, and the boss has an inclination angle of 20 °, 30 °, and 37.5 °, three types of B _{1 to} B ₃ , and the outer radius of the wing is 212.5 mm, the wing width When the pressure coefficient with respect to the flow coefficient was measured for each of 49 mm and the boss inclination angle of 30 °, the performance curves shown in FIGS. 4 to 6 were obtained. Here, the fan of the present invention is used in the range where the pressure coefficient Ψ is 0.2 to 0.35, and the fans having high flow coefficient and efficiency in this range are as shown in the comprehensive judgment in the above table. In this table, ◯ indicates the best, X indicates inferior performance, and Δ indicates slightly inferior performance. That is, the fourth
In A _{1 to} A _{3 in the} figure, the performance with the boss angle of 20 ° is the best, and the performance with 37.5 ° is the worst. And the one at 30 ° is a little inferior. For B _{1 to} B ₃ , the boss angle of 30 ° is the best, and the boss angle of 20 ° and the boss angle of 3 °
7.5 ° was a little inferior. The C ₁ fan shown in FIG. 6 has a relatively good performance curve even if the blade thickness (width) is relatively small.

FIG. 7 is a group of curves in which the horizontal axis represents the boss angle θ and the vertical axis represents T / B with F / B and D / T, which are the elements of the fan, as parameters. Here, the values of θ and T / B of the seven fans described above are represented by points A _{1 to} A ₃ , B _{1 to} B ₃ , and C. Of these, the best points are A ₁ , B ₂ , and C. A little inferior performance is A ₂ ,
B ₁ and B ₃ . From this, as a fan of this kind, F
It can be seen that good performance is obtained when / B is in the range of 0.25 to 0.45 and D / T is in the range of 0.35 to 1.1.

The pressure coefficient Ψ and the flow coefficient Φ are expressed by the following equations.

Attachment Further, in the table, K is the ratio of the inlet flow passage area A ₁ at the front edge of the blade and the outlet flow passage area A ₂ at the rear edge.

〔The invention's effect〕

The radiator fan of the present invention is a high static pressure fan having a truncated cone boss portion and a pressure coefficient of 0.20 to 0.35. As a result of experiments, as a result of the experiment, the inclination angle θ of the boss portion, the blade width T, and the average blade length B are shown. The relations with and are expressed as F / B and B / T which are expressed as optimum values from the table and FIG. 7, and those values are F / B =
Since 0.25 to 0.45, B / T = 0.35 to 1.1 and S / T is set to 0.6 to 0.8, the efficiency is high with large air volume and low power consumption. Moreover, there has never been a high static pressure fan that specifies all these relationships.

[Brief description of drawings]

FIG. 1 is a schematic axial cross-sectional view showing a usage state of the radiator fan, FIG. 2 shows a main part thereof, FIG. 3 is a front view of the fan, and FIGS. FIG. 7 shows the relationship between the flow coefficient, pressure coefficient and efficiency of each manufactured fan, and FIG. 7 shows a group of curves expressing F / B and D / T as parameters. 1 ... Boss part, 2 ... Wing part l ... Virtual line, 3 ... Cylindrical part 4 ... Radiator, 5 ... Tank 6 ... Annular rubber plate, 7 ... Mounting surface 8 ... Clutch, 9 …… Engine 10 …… Stay, 11 …… Lead edge 12 …… Front edge, 13 …… Rear edge 14 …… Shroud body

Claims (1)

[Claims] 1. A pressure coefficient Ψ = 0.20 to 0.35, the boss portion (1) has a truncated cone shape, and a plurality of blade portions (2) are arranged at equal intervals on the outer periphery of the boss portion (1). The radial tip edge of the wing portion is formed parallel to the axis of the boss portion (1), and the radius R ₀ of the tip end of the wing portion (2) and the radius Rb of the center root of the front and rear edges of the wing portion (2) The relationship is Rb / R ₀ = x = 0.35 to 0.55, and the cylindrical portion (3) of the shroud is arranged so that the rear end portion of the tip edge is exposed in the vicinity of the tip edge of the blade portion (2). The axial length S is fitted, and the fitting ratio is relative to the blade width T.
In a radiator fan with S / T = 0.6 to 0.8, the height B of the blade at the center of the front and rear edges is B = R ₀ −Rb, and the radius of the leading edge and the rear of the blade at the root of the blade (2). When the difference from the radius of the edge is F, there is a relationship of F / B = 0.25 to 0.45, and an imaginary line 1 that is orthogonal to the outer surface of the boss (1) at the root of the trailing edge of the blade (2). Is projected onto the wing (2), the distance D between the intersection of the imaginary line 1 and the leading edge of the wing (2) and the trailing edge of the wing (2) is the wing. D / T = for width T
A radiator fan characterized by a relationship of 0.35 to 1.1. However, the pressure coefficient Ψ shows the operating point of the fan, and shows the intersection of the pressure coefficient curves of the fan and the radiator with the flow coefficient Φ as the horizontal axis.