JPH0418018Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a pilot valve for controlling a main valve such as a pressure control valve, and more specifically, to a pilot valve having a nozzle flap mechanism. be.

[Prior Art] The applicant of the present invention previously proposed a precision pressure reducing valve having a nozzle flapper mechanism as the IR400 series.

The precision pressure reducing valve shown in detail in FIG. 7 has main valve 2.
and a pilot valve 1. This pilot valve 1 connects the supply port P of the main valve 2 and the pilot chamber 3.
a nozzle flap chamber 8 having a nozzle flap mechanism including a nozzle 6 and a flapper 7 for communicating the pilot chamber 3 to the outside; a bleed hole 9 that communicates the nozzle flapper chamber 8 with the outside; a feedback chamber 11 located above the nozzle flapper chamber 8 and communicated with the output port A of the main valve 2 through a feedback passage 10; A pressure regulating chamber 14 having a pressure regulating spring 13 whose biasing force can be adjusted by rotating the handle 12, and the feedback chamber 11 and the pressure regulating chamber 14 are separated, and the acting force of the secondary pressure of the feedback chamber 11 and the pressure regulating spring are separated. 1
The nozzle flap chamber 8 and the feedback chamber 11 are separated by a seal diaphragm 16 that is displaced integrally with the diaphragm 15.

The pilot valve 1 is connected to the output port A of the main valve 2.
When the secondary pressure of diaphragm 15 is lower than the set pressure set by pressure regulating spring 13,
As the nozzle flapper mechanism is closed by the downward movement of the seal diaphragm 16, the pilot chamber 3
The fluid pressure increases, causing the diaphragm 18 and valve stem 19 of the main valve to move downward, causing the supply valve body 20 to close to the supply valve seat 2.
1 is opened, the pressure fluid in the supply port P flows out to the output port A, and the secondary pressure in the output port A gradually increases.

In addition, when the secondary pressure of the output port A is higher than the set pressure, the nozzle flapper mechanism opens due to the upward movement of the diaphragm 15 and the seal diaphragm 16, so the fluid pressure in the pilot chamber 3 decreases and the main valve The diaphragm 18 and valve stem 19 are moved upward, and the valve stem 19 opens the discharge valve seat 22, and the pressure fluid in the output port A flows out to the discharge port R, and the secondary pressure in the output port gradually decreases.

However, since the pilot valve 1 has the feedback chamber 11 above the nozzle flapper chamber 8, a sealing member is required to seal between the chambers 8 and 11. The problem is that it cannot be made into a high-performance one.

That is, if the sealing member between the chambers 8 and 11 is a seal diaphragm 16 as shown in FIG. Since the pressure-receiving area of the diaphragm 15 in between is reduced by an amount equivalent to the pressure-receiving area of the seal diaphragm 16,
Since it is necessary to increase the pressure receiving area of the diaphragm 15, the pilot valve cannot be made smaller.

Furthermore, if the seal member is replaced with a sliding seal such as an O-ring in place of the seal diaphragm 16,
The large resistance during starting reduces the performance of the pilot valve.

As shown in Figure 8, the performance of the pilot valve means that the difference between the set pressure and the fluid pressure when the main valve starts to open is small, in other words, the sensitivity of the main valve is high; As shown in FIG. 9 and FIG. 9, this means that the hysteresis of the fluid pressure and flow rate when the main valve is opened is small.

[Problem to be Solved by the Invention] The problem to be solved by the invention is to make a pilot valve having a nozzle flapper mechanism small in size and high in performance.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a pilot valve for supplying pilot fluid to a pilot chamber of a main valve, in which the pilot valve is connected to a supply port of the main valve and the above pilot valve. A pilot passage for communicating the pilot chamber, a fixed throttle in the pilot passage, a feedback chamber on the main valve side, a feedback passage for communicating the feedback chamber with the output port of the main valve, and a fixed throttle in the pilot passage. A pressure regulating chamber that communicates with the outside and is provided on the opposite side of the main valve, a pressure regulating spring that is compressed in the pressure regulating chamber and whose biasing force can be adjusted, and a feedback chamber that separates the feedback chamber and the pressure regulating chamber. a diaphragm that is displaced depending on the magnitude of the acting force of the fluid pressure and the biasing force of the pressure regulation spring in the pressure regulation chamber; A nozzle flapper mechanism that cuts off communication with the pressure chamber is featured.

[Operation] When the feedback fluid pressure acting on the feedback chamber is higher than the set pressure of the pressure regulating spring, the diaphragm is displaced toward the pressure regulating chamber, thereby opening the nozzle flapper mechanism and lowering the pilot fluid pressure. If the feedback fluid pressure acting on the feedback chamber is lower than the set pressure,
The diaphragm is displaced toward the feedback chamber, which closes the nozzle flapper mechanism and increases the pilot fluid pressure.

Therefore, the pilot fluid pressure can be made the set pressure of the pressure regulating spring.

In this case, since the nozzle flapper mechanism is provided in the pressure regulation chamber located on the opposite side of the main valve of the feedback chamber, the gap between the feedback chamber and the nozzle flapper mechanism can be sealed by a diaphragm for pressure regulation. There is no need to provide a seal member.

Therefore, since the pressure-receiving area of the diaphragm can be reduced, the pilot valve can be made smaller, and since there is no need to use a sliding seal to make it smaller, the pilot valve can have higher performance.

[Embodiment] FIG. 1 shows a first embodiment of the present invention, in which a pilot valve 30 controls the secondary pressure of a main valve 31 shown in detail in FIG. 2 to a desired set pressure.

The body 33 of the pilot valve 30 is connected to the main valve 3.
An input port 34 that communicates with the supply port P of the main valve and an output port 35 that communicates with the pilot chamber of the main valve are provided on the mounting surface of the main valve 1, and a pilot passage 36 that communicates the openings 34 and 35 has a A fixed aperture 37 is removably mounted by a ring 38.

The chamber formed in the body 33 is connected to the diaphragm 4
0 into a feedback chamber 41 on the main valve side and a pressure regulation chamber 42 on the opposite side, and the feedback chamber 41 is connected to the output port A of the main valve 31 by a feedback passage 43, and a pressure regulation chamber 42 communicate with the outside through bleed holes 44, respectively.

The rear end portion of a nozzle body 46 is fixed to the output port 35 by a mounting nut 47, and the outer periphery of the middle portion of the nozzle body 46, which has passed through the body 33 in an airtight manner, is airtightly fixed to the diaphragm 40. , a nozzle flapper mechanism consisting of a nozzle 48 and a flapper 49 at its tip opens into the pressure regulating chamber 42 . Further, a diaphragm shell 51 that covers the nozzle flap mechanism is fixed to an intermediate portion of the diaphragm 40 on the pressure regulating chamber side, and the nozzle flap chamber 50 provided in the diaphragm shell 51 is connected to a plurality of passages 52, . Pressure adjustment chamber 4
It is connected to 2.

A pressing nut 54 provided in the bonnet 33a of the body 33 is screwed onto a bolt that rotates together with the handle 55, and is attached so that it can only move forward and backward in the axial direction with respect to the bonnet 33a. A pressure regulating spring 57 is compressed between the diaphragm shells 51.

Reference numeral 58 in FIG. 1 is a filter element provided at the input port 34.

FIG. 2 shows an example of how the pilot valve 30 is used, and the main valve 31 shown in detail in the figure includes a supply valve seat 61 that communicates the supply port P and the output port A, and a supply valve seat 61 that opens and closes the valve seat. A valve body 62 and a discharge valve seat 6 that communicates output port A and discharge port R.
3, a discharge valve body 64 that opens and closes the valve seat, and a piston 6
5, a pilot chamber 66 communicating with the output port 35 of the pilot valve 30, and a main valve feedback chamber 67 communicating with the output port A, one end of which is fixed to the piston 65, and the valve body 6 located in the middle.
2 and 64, and a rod 69 having locking portions 68 and 68, which are configured as a known pressure control valve. Reference numeral 70 in FIG. 2 is a pressure gauge that opens into the main valve feedback passage that communicates the output port A and the main valve feedback chamber 67.

Next, referring to FIG. 2, the pilot valve 3
The pressure regulating operation of the main valve 31 due to 0 will be explained.

When the fluid pressure at the output port A of the main valve 31, in other words, the fluid pressure in the feedback chamber 41 of the pilot valve 30, is lower than the set pressure of the pressure regulating spring 57, the intermediate annular portion of the diaphragm 40 and the diaphragm shell 51 is displaced downward and the nozzle flapper chamber 50 closes the nozzle flapper mechanism, so that the fluid pressure in the pilot chamber 66 of the main valve increases. Therefore, the piston 65 and the rod 69 move downward in the figure according to the pressure difference between the pilot chamber 66 and the main valve feedback chamber 67, and the supply valve body 62
The locking portion 68 that locks the supply valve body 62 opens the supply valve seat 61, thereby opening the output port A and the feedback chamber 41 of the pilot valve 30.
The fluid pressure gradually increases.

In addition, output port A and feedback chamber 41
When the fluid pressure of
0 opens the nozzle flapper mechanism, the fluid in the pilot chamber 66 of the main valve flows out through the nozzle flapper mechanism and the pressure regulating chamber 42, and its fluid pressure decreases. Therefore, the piston 65 and the rod 69 rise, and the locking part 68 that locks on the discharge valve body 64 drives the discharge valve body 64 to open the discharge valve seat 63, thereby opening the output port A and the discharge valve seat 63. The fluid pressure in the feedback chamber 41 gradually decreases.

After the fluid pressures in the output port A and the feedback chamber 41 are increased and decreased in this manner, the fluid pressure in the feedback chamber 41 is increased by the pressure regulating spring 57.
When the pressure becomes equal to the set pressure, the fluid pressure in the main valve feedback chamber 67 in the main valve also becomes equal to the set pressure, and in this state, the piston 65 stops at the neutral position shown in FIG. 2, and the valve seats 61 and 63 close. be done.

In addition, in the first embodiment, the fixed aperture 3
7, the fluid pressure of the pilot fluid flowing into the pilot chamber 66 can be changed.

In the first embodiment, the outer periphery of the intermediate portion of the nozzle body 46 is airtightly fixed to the diaphragm 40 that partitions the feedback chamber 41 and the pressure adjustment chamber 42, and the nozzle flapper mechanism is opened to the pressure adjustment chamber 42. Therefore, a seal member such as a seal diaphragm or a sliding seal that seals between the feedback chamber 41 and the nozzle flap chamber 50 can be omitted, so the pilot valve 30 can be made compact and high-performance.

FIG. 3 shows a second embodiment of the present invention, in which a pilot valve 72 has two removable fixed throttles 73, 73 arranged in series in the pilot passage 36. The second embodiment has two fixed apertures 73, 7.
3 in series, the cross-sectional area of the aperture can be increased by approximately 1.4 times compared to the case where there is only one fixed aperture, so the aperture is less likely to be clogged by dust.

The other configurations and operations of the second embodiment are the same as those of the first embodiment, so the same reference numerals are used in the drawings and detailed explanations will be omitted.

4 and 5 show a third embodiment of the present invention,
This pilot valve 75 has a fixed throttle 76 in the pilot passage 36 provided with a cleaning pin 77 for cleaning the clogged throttle so as to be slidable in the axial direction with respect to the throttle 76. Therefore, the cleaning pin 77 can clean the fixed diaphragm 76 from clogging.

Further, the diaphragm 40 that partitions the feedback chamber 41 and the pressure regulation chamber 42 is provided between the feedback chamber 41 and the partition plate 80, and a diaphragm shell 81 fixed to the diaphragm 40 is provided between the feedback chamber 41 and the partition plate 80.
and the spring seat 82 above the partition plate 80.
The nozzle 84 of the nozzle flapper mechanism provided in the partition plate 80 and the output port 35 are integrally connected by a plurality of pillars 83, . 58 (see Figure 5).

The other functions of the third embodiment are the same as those of the first embodiment except that the displacement of the diaphragm 40 is transmitted to the spring seat 82 via the diaphragm shell 81, the pillars 83, . is omitted.

FIG. 6 shows an example of the manner in which the pilot valve 75 is used. The input port 34, the output port 35, and the feedback passage 43 of the pilot valve 75 placed next to the main valve 32 are opened on the side surface of the pilot valve 75. ing.

The main valve 32 shown in FIG. 6 is substantially the same as the main valve 31 shown in FIG.
Since the operations are substantially the same, the same parts in the figures are given the same reference numerals and detailed explanations will be omitted.

[Effects of the invention] The pilot valve of the invention communicates the nozzle flapper mechanism with the pressure regulating chamber provided on the opposite side of the feedback chamber from the main valve, thereby omitting the sealing member that seals between the feedback chamber and the nozzle flapper mechanism. As a result, there is no increase in the diameter of the diaphragm or increase in sliding resistance caused by this sealing member.
The pilot valve can be made small and high-performance.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of the first embodiment of the present invention, FIG. 2 is a longitudinal sectional front view showing an example of the usage mode of the first embodiment, and FIGS. 3
5 is a sectional view taken along the line A-A in FIG. 4, FIG. 6 is a longitudinal sectional front view showing an example of how the third embodiment is used, and FIG. 7 is a known device having a nozzle flapper mechanism. 8 and 9 are explanatory diagrams of the performance of the pilot valve. 30,72,75...Pilot valve, 31,3
2...Main valve, 36...Pilot passage, 37,7
3, 76... fixed aperture, 40... diaphragm,
41...Feedback room, 42...Pressure control room, 4
3... Feedback passage, 48, 84... Nozzle, 49... Flutter, 57... Pressure regulating spring, 66... Pilot chamber, P... Supply port,
A...Output port.

Claims (1)

[Claims for Utility Model Registration] A pilot valve for supplying pilot fluid to a pilot chamber of a main valve, wherein the pilot valve includes a pilot passage for communicating a supply port of the main valve with the pilot chamber; A fixed throttle in the pilot passage, a feedback chamber on the main valve side, a feedback passage for communicating the feedback chamber with the output port of the main valve, and a feedback chamber provided on the opposite side of the main valve to communicate with the outside. A pressure regulating chamber, a pressure regulating spring which is compressed in the pressure regulating chamber and whose biasing force can be adjusted; a diaphragm that is displaced depending on the magnitude of the biasing force of a pressure regulating spring; and a nozzle flapper mechanism that is provided on the pressure regulating chamber side of the diaphragm and that disconnects communication between the pilot passage and the pressure regulating chamber by displacement of the diaphragm. A pilot valve comprising: