JPH0760164A - Contraction nozzle - Google Patents

Abstract

PURPOSE:To keep a fluid coming-lose and falling and scattering start point away from the outlet of a nozzle as far as possible, to make good the spraying position of a spray nozzle to improve the appearance and to increase the range of a discharge nozzle to perform a long-distance discharge. CONSTITUTION:A body part 9 having an inner peripheral surface 4A whose diameter is gradually reduced from the inlet 2 side to near the outlet 3 is formed, and a reduced diameter part 6 having an inner peripheral surface 6A whose diameter is sharply reduced and opened at the reduced end is formed successively to the body part 4, and also a short straight pipe part 5 whose axial size is short is provided successively to the reduced diameter part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contraction nozzle suitable for a fountain nozzle and a long-distance water discharge nozzle.

[0002]

2. Description of the Related Art As conventional fountain nozzles and long-distance water discharge nozzles, those shown in FIGS. 3 to 5 are known. That is, the nozzle 1 of FIG. 3 is configured by the body portion 4 in which the inner peripheral surface 4A gradually reduces in diameter from the inlet 2 side to the outlet 3. According to this type of nozzle 1, the fluid W flowing from the inlet 2 is gradually throttled by the inner peripheral surface 4A as the fluid W flows toward the outlet 3, and the speed is gradually increased. Immediately after being rectified by suppressing the development of the boundary layer, it is ejected from the outlet 3. Therefore, exit 3
The velocity distribution at is as shown by the arrow group A. That is, the velocity of the fluid W in the outer peripheral portion of the body portion 4 near the inner peripheral surface 4A is lower than the velocity of the central portion and its peripheral portion (hereinafter, simply referred to as the central portion) due to the influence of frictional resistance with the inner peripheral surface 4A. It becomes too late to follow the flow in the central part, and immediately after it is ejected from the outlet 3, it becomes a water droplet, which falls off and scatters.
As a result, the flow at the boundary between the jetted fluid W and the atmosphere is disturbed. When such a nozzle 1 is used as a fountain nozzle, the appearance of the fountain is impaired and the appearance of the fountain is deteriorated. Further, when it is used as a water discharge nozzle, long distance water discharge cannot be executed.

On the other hand, the nozzle 1 shown in FIG. 4 has a main body 4 whose inner peripheral surface 4A gradually reduces in diameter from the inlet 2 side to the vicinity of the outlet 3, and a uniform opening provided continuously to the main body 4. It has a structure including a straight pipe portion 5 having a large inner diameter. According to this type of nozzle 1, the fluid W flowing in from the inlet 2 is gradually throttled by the inner peripheral surface 4A as the fluid W flows toward the straight pipe portion 5, and the speed is gradually increased. After being rectified by suppressing the development of the boundary layer to some extent, it is jetted from the outlet 3 through the straight pipe part 5. However, this type of nozzle 1 also exhibits the same velocity distribution as the nozzle 1 of FIG. 3, and when used as a fountain nozzle, the appearance of the fountain is impaired and the appearance of the fountain deteriorates. Further, when it is used as a water discharge nozzle, long distance water discharge cannot be executed.

On the other hand, in the nozzle 1 shown in FIG. 5, an inner peripheral surface 4A is gradually reduced in diameter from the inlet 2 side to the vicinity of the outlet 3, and a main body portion 4 is provided with an inner peripheral surface 6A continuous with the main body portion 4. A structure including a diameter-reduced portion 6 that sharply reduces its diameter and a straight pipe portion 5 that is provided continuously to the diameter-reduced portion 6 and has a uniform inner diameter and a long axial dimension (1-2 times the inner diameter d) It has become. According to the nozzle 1 of this type, the fluid W flowing from the inlet 2 is gradually throttled by the inner peripheral surface 4A as the fluid W flows toward the reduced diameter portion 6, and the speed is gradually increased. After being rectified by suppressing the development of the boundary layer to some extent, it is sharply narrowed by the inner peripheral surface 6A of the reduced diameter portion 6. As a result, the outer peripheral portion of the fluid near the inner peripheral surface 6A of the reduced diameter portion 6 is accelerated, and a substantially uniform velocity distribution is obtained. The fluid W that has passed through the reduced diameter portion 6 causes a contracted flow, but after passing through the straight pipe portion 5 having a long axial dimension, it is reattached and then ejected from the outlet 3. Therefore, this type of nozzle 1 also exhibits the same velocity distribution as the nozzle 1 of FIGS. 3 and 4, and when used as a fountain nozzle, the appearance of the fountain is impaired and the appearance of the fountain deteriorates. Further, when it is used as a water discharge nozzle, long distance water discharge cannot be executed. Therefore, when used as a fountain nozzle, the appearance of the fountain can be improved and the appearance can be improved, and when used as a water discharge nozzle, the flight distance can be increased and long-distance water discharge can be performed. Development is required.

[0005]

The problem to be solved is that the appearance of the fountain is impaired by the fountain nozzle, which deteriorates the appearance of the fountain, and the water discharge nozzle cannot perform long-distance water discharge.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a main body portion whose inner peripheral surface gradually reduces in diameter from an inlet side to an outlet, and an inner peripheral surface which is provided continuously to the main body portion and whose diameter decreases sharply. It is characterized by having a reduced diameter portion that opens as a result.By ejecting the fluid with a nearly uniform velocity distribution, the start point of the fluid scattering and scattering is kept as far as possible from the nozzle outlet, and the fountain nozzle has a good fountain appearance. The appearance was improved, and the flight distance was increased with the water discharge nozzle to achieve the purpose of performing long-distance water discharge.

[0007]

According to the present invention, as the fluid flowing from the inlet flows toward the reduced diameter portion, the fluid is gradually throttled by the inner peripheral surface of the main body portion and gradually increased in speed. After suppressing the development of the boundary layer to some extent and being rectified,
It is sharply narrowed by the inner peripheral surface of the reduced diameter portion. This allows
The fluid in the outer peripheral portion near the inner peripheral surface of the reduced diameter portion is accelerated and jetted from the outlet with a substantially uniform velocity distribution.
Therefore, the starting point of fluid splashing and scattering is moved away from the outlet.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a fountain nozzle of the present invention. The same or corresponding parts as those in the conventional example will be described with the same reference numerals. In FIG. 1, a fountain nozzle 1
Is a body portion 4 in which the inner peripheral surface 4A gradually reduces in diameter from the inlet 2 side to the outlet 3 and a diameter reduction in which the inner peripheral surface 6A provided continuously to the main body portion 4 sharply reduces in diameter and opens. It comprises a part 6. That is, the inclination angle θ1 of the inner peripheral surface 4A of the body portion 4 is set to about 2 ° ≦ θ1 ≦ 4 °, and the inclination angle θ2 of the inner peripheral surface 6A of the reduced diameter portion 6 is 10 ° ≦ θ2.
It is set to about ≦ 30 °, and the ratio between the minimum inner diameter D of the inner peripheral surface 4A of the main body 4 and the minimum inner diameter d of the inner peripheral surface 6A of the reduced diameter portion 6, that is, the minimum inner diameter D and the diameter of the outlet 3. The ratio d / D with d is set to about 0.7 to 0.8.

In the above structure, the fluid W flowing from the inlet 2 is gradually narrowed by the inner peripheral surface 4A of the main body 4 as the fluid W flows toward the reduced diameter portion 6, and the speed is gradually increased.
After being rectified by suppressing the development of the boundary layer to some extent by the gentle throttling action, it is sharply throttled by the inner peripheral surface 6A of the reduced diameter portion 6. As a result, the fluid in the outer peripheral portion close to the inner peripheral surface 6A is accelerated, resulting in a substantially uniform velocity distribution (see arrow group A).
Will spout from the outlet 3. Therefore,
The expulsion start point of the fluid W, that is, the expulsion start point of water droplets is moved away from the outlet 3. Therefore, this nozzle 1
When used as a fountain nozzle, the appearance of the fountain can be improved and the appearance can be improved, and when used as a water discharge nozzle, long-distance water discharge can be performed by increasing the flight distance. In particular, by installing the fountain nozzle at an angle and ejecting the fluid obliquely upward, it is possible to walk the viewer without getting wet under the arch formed by the fountain, which is a dramatic effect of the fountain. It is possible to improve.

FIG. 2 shows another embodiment of the present invention, in which the fountain nozzle 1 has an inner peripheral surface 4 extending from the inlet 2 side to the vicinity of the outlet 3.
A is gradually reduced in diameter, and an inner peripheral surface 6 </ b> A is provided continuously to the main body 4 and the reduced diameter portion 6 and the reduced diameter portion 6 are opened continuously. The structure is provided with a straight pipe portion 5 having a uniform inner diameter and a short axial dimension (0.5 times or less of the inner diameter d). Further, the inclination angle θ1 of the inner peripheral surface 4A of the main body portion 4 is set to about 2 ° ≦ θ1 ≦ 4 ° as in the embodiment of FIG. 1, and the inclination angle θ2 of the inner peripheral surface 6A of the reduced diameter portion 6 is set. Also as in the embodiment of FIG.
The minimum inner diameter D of the inner peripheral surface 4A of the main body portion 4 and the minimum inner diameter d of the inner peripheral surface 6A of the reduced diameter portion 6 and the inner diameter d of the straight pipe portion 5 are set to 0 ° ≦ θ2 ≦ 30 °. Percentage,
That is, the ratio d / D between the minimum inner diameter D and the diameter d of the outlet 3 is set to about 0.7 to 0.8.

With this structure, the fluid W flowing from the inlet 2 is gradually narrowed by the inner peripheral surface 4A of the main body 4 as the fluid W flows toward the reduced diameter portion 6, and the speed is gradually increased. Then, after being gradually rectified by suppressing the development of the boundary layer to a certain extent by the gentle throttling action, it is sharply throttled by the inner peripheral surface 6A of the reduced diameter portion 6. As a result, the fluid in the outer peripheral portion close to the inner peripheral surface 6A is accelerated and a substantially uniform velocity distribution is obtained.
The fluid W that has passed through the reduced diameter portion 6 causes a contraction flow, but by passing through the straight pipe portion 5 having a short axial dimension, the fluid W is ejected from the outlet 3 without reattachment. Therefore, even with this type of nozzle 1, as in the case of the nozzle 1 of FIG. 1, the nozzle 3 ejects from the outlet 3 with a substantially uniform velocity distribution (see arrow group A). As a result, the start point of the splashing and scattering of the fluid W, that is, the start point of the splashing and scattering of the water droplets is moved away from the outlet 3.
Therefore, when this nozzle 1 is used as a fountain nozzle, the fountain shape can be improved and the appearance can be improved. When it is used as a water discharge nozzle, the flight distance is increased and long-distance water discharge is executed. can do. In particular, by installing the fountain nozzle at an angle and ejecting the fluid obliquely upward, it is possible to walk the viewer without getting wet under the arch formed by the fountain, which is a dramatic effect of the fountain. It is possible to improve.

[0012]

As described above, according to the present invention, the jetting start point of the fluid can be moved as far as possible from the outlet of the nozzle by jetting the fluid at a substantially uniform velocity distribution. The appearance can be improved to improve the appearance, and the water discharge nozzle can increase the flight distance to perform long-distance water discharge.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing another embodiment of the present invention.

FIG. 3 is a vertical sectional view of a conventional example.

FIG. 4 is a vertical cross-sectional view showing another conventional example.

FIG. 5 is a vertical sectional view showing still another conventional example.

[Explanation of symbols]

 1 Nozzle 2 Nozzle Inlet 3 Nozzle Outlet 4 Body 4A Inner Surface of Body 6 Reduced Diameter 6A Inner Diameter of Reduced

Claims (1)

[Claims] 1. A main body portion having an inner peripheral surface whose diameter gradually decreases from the inlet side to the vicinity of the outlet, and a diameter-reduced portion which is continuous with the main body portion and whose inner peripheral surface sharply reduces its diameter and opens. A contraction nozzle that is characterized by