JPH049102B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to fluid injection nozzles.

A conventional injection nozzle is shown in FIG. 1, and its outline will be described.

The conventional injection nozzle 10 introduces high-pressure fluid through the inlet pipe 11, and when the differential pressure between the fluid pressure acting on the pressure-receiving surface 13 of the valve stem 12 and the pressure in the nozzle chamber 17 exceeds a certain value, , the valve rod 12 is pushed out to the right in FIG. 1 against the force of the spring 14, and the fluid that has flowed into the nozzle chamber 17 from the passage 150 is ejected from the ejection hole 15.

The differential pressure between the pressure receiving surface 13 and the nozzle chamber 17 is caused by pressure loss when fluid passes between the pressure receiving surface 13 and the side surface 16, and pressure loss is related to the flow rate of the fluid. The movement of the valve stem 12 of these types of valves tends to generate self-excited vibrations and is unstable, making it difficult to control the flow rate.

Further, since a pressure loss occurs when the fluid flows between the pressure receiving surface 13 and the side surface 16, the pressure of the fluid decreases, and there is a problem that the speed at which the fluid is ejected from the ejection hole 150 decreases.

The present invention was made in order to solve the problems of conventional injection nozzles, and provides an injection nozzle that opens and closes only by fluid pressure, allows easy flow control, and has little pressure loss up to the injection hole. The purpose of this new feature is a. The expansion and contraction force of the bellows due to the fluid pressure difference between the intermediate chamber and the low pressure chamber becomes greater than the force of the spring that presses the valve stem, so that the nozzle is opened. (b) A low-pressure chamber unrelated to the fluid pressure was provided; (c) The fluid passage and the low-pressure chamber were separated by a stretchable membrane material (bellows), and the membrane material was attached to the valve stem. At one end and a fixed point.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG.

As shown, an injection nozzle case 10 has an inlet 110 at one end and an ejection hole 150 at the other end.
Valve seat 190 provided near the nozzle hole 150 in 0
and the valve sealing surface 180 of the valve stem tip 120 constitute a valve mechanism.

Nozzle chamber 170 inside injection nozzle case 100
A partition plate 240 having a plurality of communication holes 230 is provided between the valve stem tip 120 and the intermediate chamber 220.
The spring 140 exerts a force that pushes the valve toward the valve seat 190.
Install.

The other end of the valve stem 250 is fixed to the bellows 200,
It is installed in a low pressure chamber 300 that communicates with the outside air through a vent hole 310 in the bellows 200.

Next, the action and effect will be explained.

The liquid entering from the inlet 110 passes through the passage 210 and enters the intermediate chamber 220.

When the pressure of the fluid in the intermediate chamber 220 increases, the bellows 200 is pushed and expanded due to the pressure difference between it and the low pressure chamber 300, moving the valve stem 120 toward the low pressure chamber 300, causing the valve seal surface 180 and valve seat 190 to contact each other. A gap is created and fluid is ejected through the ejection hole 150.

The gap between the valve sealing surface 180 and the valve seat 190 is determined by the differential pressure acting on the spring 140 and the bellows 200, and is determined independently of the flow rate.

When the differential pressure acting on the bellows 200 is made larger than the force of the spring 140, the inlet pipe 110
The pressure loss between 50 and 50 is small, and the flow rate is
50 and the pressure in front of the fluid inlet 110.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional fluid injection nozzle, and FIG. 2 is a sectional view showing the configuration of the injection nozzle according to the present invention. 100...Injection nozzle case, 110...Inflow port, 120...Valve stem tip, 140...Spring, 15
0...Ejection hole, 170...Nozzle chamber, 180...
Valve sealing surface, 190... Valve seat, 200... Bellows, 210... Passage, 220... Intermediate chamber, 230
... Communication hole, 240 ... Partition plate, 250 ... Valve stem, 300 ... Low pressure chamber, 310 ... Ventilation hole.

Claims (1)

[Claims] 1. In a fluid injection nozzle that senses fluid pressure and opens an ejection hole, one end of the valve stem is placed on the pressure receiving surface between a low pressure chamber that has a vent that communicates with the outside air and an intermediate chamber where the flowing fluid pressure acts. A fixed bellows is provided, and a spring is provided that pushes the valve stem in a direction to close the jet hole, and the force of the bellows expanding due to the pressure difference of the fluid between the intermediate chamber and the low pressure chamber pushes the valve stem. A fluid ejection nozzle, characterized in that the ejection hole is opened when the force of the fluid becomes larger than that of a spring.