JPH07229569A - Poppet valve - Google Patents

Abstract

PURPOSE:To quickly discharge air inside a spring chamber to the outside in a start of use so as to prevent a poppet from vibrating and so as to carry out normal operation immediately. CONSTITUTION:In a poppet 25, an outside diameter of a sliding unit 25a is slightly reduced so that a clearance forming part 25c forming a clearance 41 between a sliding hole 22a and the sliding unit 25a is arranged, and inflow throttles 43a, 43c and the like are formed in the clearance forming part 25c. Plural outflow ports 33a and the like are formed in the circumference direction in a cage 22 and arranged so that either of the outflow port corresponds to either of the inflow throttles. In this way, fluid penetrates into a part, which is not matched with the outflow port 33a, of the clearance 41 so as to increase a pressure in this vicinity and enters a spring chamber 37 from the nearby inflow throttle, so that a flow of fluid flowing out from the inflow throttle in the position corresponding to the outflow port is formed, and as a result, air inside the spring chamber 37 is discharged rapidly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed so that a poppet having a conical surface at its tip is pressed against a sheet and the pressure between the conical surface and the sheet is opened to control the pressure of the fluid flowing out to the outflow passage. Direct-acting poppet valve

[0002]

2. Description of the Related Art Conventionally, as a direct-acting type poppet valve of this kind, there is one shown in FIG. 11, for example. In this poppet valve 1, a male screw portion formed on the outer periphery on the one end side of a cage 2 is screwed to a female screw portion of a retainer 3, a seat 4 and a sliding hole 2a are formed in the cage 2, and The sliding portion 5a of the poppet 5 is movably fitted in the sliding hole 2a.

A spring receiver 6 forming a part of a spring chamber 17 is screwed into a screw hole formed in the center of the retainer 3, and an adjusting screw portion outside the portion of the spring receiver 6 protruding from the retainer 3. 7, a lock nut 8 and a cap nut 9 are screwed onto each other.

Further, a spring 11 is provided in a spring chamber 17 formed between the spring receiver 6 and the poppet 5.
The poppet 5 is urged downward in FIG. 11 by the urging force of the spring 11. In this poppet valve 1, a male screw portion formed on the lower outer peripheral surface of the retainer 3 in FIG.
Use by fixing it by screwing it into the female screw part of.

Then, in this state, the conical surface 5b at the tip of the poppet 5 is urged in the direction of contacting the seat 4 of the cage 2, flows in from the inflow port 12 of the block 15, and becomes the conical surface 5b of the poppet 5. The pressure of the fluid flowing from the outflow chamber 14 to the outflow port 16 through the outflow port (outflow passage) 13 through the space between the sheet 4 and the sheet 4 is controlled to a set pressure.

The spring chamber 17 is connected to the outflow chamber 14 through a slit groove 18 formed at a predetermined depth along a vertical direction in FIG. It is in communication. And the slit groove 1
The cages 8 are formed at two locations spaced apart in the circumferential direction of the cage 2.

In the poppet valve 1, when the pressure of the fluid to be controlled is changed, the cap nut 9 is removed, the lock nut 8 is loosened, the spring receiver 6 is rotated, and the retainer 3 is moved to the retainer 3 in FIG. Move vertically and adjust.

Then, the lock nut 8 is re-tightened and fixed at a position where the spring force of the spring 11 reaches a desired value, and a cap nut 9 for preventing erroneous operation is attached to the adjusting screw portion 7 of the spring receiver 6. Prevent the spring receiver 6 from rotating accidentally.

[0009]

However, in such a conventional poppet valve, a plurality of spring chambers (two in the example of FIG. 11) are formed in the outer circumference of the cage.
Since it was only communicating with the outflow chamber by the slit groove of, the assembled poppet valve was used to form a hydraulic circuit, and at the first use of it, only air entered the spring chamber. Therefore, when the operation is started, the air is gradually pushed out by the fluid (oil) entering the spring chamber, but the air does not easily escape from the spring chamber even if the operation is continued. There was a problem.

If a certain amount or more of the air remains in the spring chamber, the air is more easily compressed than oil, and the damping effect against the vibration of the poppet is poor. Therefore, until most of the air escapes from the spring chamber. When the pressure fluctuates, the poppet vibrates, resulting in noise, and in some cases, the poppet and cage are damaged and cannot be used continuously.

In particular, the oil passage (tank line) between the outflow port 16 shown in FIG. 11 and a tank (not shown) connected thereto is long, or the inner diameter of the oil passage reaching the tank is small. If the fluid flowing there receives a high resistance, the air in the spring chamber may not fully escape even after using the poppet valve for a long time.
There were times when the vibration did not subside.

The present invention has been made in view of the above problems, and even if air is contained in the spring chamber as in the case of using the spring chamber for the first time after manufacturing, the air in the spring chamber is immediately removed after the use thereof is started. An object of the present invention is to promptly perform normal operation without causing vibration of the poppet or noise due to the fluctuation of the pressure by promptly pulling it out to the outside.

[0013]

In order to achieve the above object, the present invention provides a poppet valve as described above,
Between the conical surface of the poppet and the sliding part, the diameter should be slightly smaller than the outer diameter of the sliding part, or a groove along the sliding direction of the poppet should be partially formed and between it and the sliding hole. A gap forming portion that forms a gap is formed, and an inflow throttle that connects the gap to the spring chamber in which the spring inside the poppet is provided is formed in the gap forming portion, and an outflow throttle that communicates the spring chamber to the outflow passage. Is provided.

Further, the outflow throttle may be formed on the conical surface portion of the poppet. Further, in the poppet valve, a plurality of outflow passages are formed in the cage at intervals in the circumferential direction, and a plurality of inflow throttles are formed in the gap forming part, and one of the inflow throttles is always one of the outflow passages. It is preferable to arrange so that a flow action region of the fluid flowing from the spring chamber to the outflow passage is formed corresponding to, and a part of the inflow throttle also serves as the outflow throttle.

[0015]

According to the poppet valve thus constructed, when the poppet valve used for the first time after manufacture has air in the spring chamber, when the operation of the hydraulic circuit to which the poppet valve is attached is started, When the poppet is opened by the pressure of the fluid to be in the pressure control state, the fluid having the flow velocity in which the pressure energy becomes the velocity energy flows between the poppet and the sheet and along the conical surface of the poppet,
It enters the gap between the gap forming portion of the poppet and the sliding hole of the cage and collides with the wall in the vicinity thereof.

Therefore, this time, the velocity energy becomes pressure energy, so that the pressure in the gap rises, whereby the fluid flowing from the inflow throttle to the spring chamber and further from the spring chamber to the outflow passage to the outflow passage. Because of the flow, the air in the spring chamber is quickly discharged to the outside of the spring chamber.

Further, since the outflow restrictor is provided between the spring chamber and the outflow passage, the fluid flowing into the spring chamber through the inflow restrictor gradually flows out while being restricted to the outside of the spring chamber by the outflow restrictor. As a result, the back pressure is applied to the spring chamber. Therefore,
Even if the poppet is displaced due to pressure fluctuation, the damping effect due to the back pressure described above effectively works, so that interference vibration of the poppet can be prevented even when the pressure in the outflow passage is high and the fluctuation is large.

Further, if the outflow restrictor is formed on the conical surface of the poppet, both the inflow restrictor and the outflow restrictor are formed on the poppet, so that the structure of the poppet valve is simplified. In addition, if an outflow passage is formed in the circumferential direction of the cage and a plurality of inflow throttles are respectively formed in the gap forming portions and one of the inflow throttles is arranged so as to always correspond to one of the outflow passages, the inflow throttle will flow out. The fluid intrudes into the above-mentioned gap in the portion that does not correspond to the passage, so that the pressure in the vicinity thereof rises.

Therefore, the flow of the fluid enters the spring chamber from the inflow throttle located near the pressure rise, and flows out to the outflow passage from the inflow throttle functioning as the outflow throttle at the position corresponding to the outflow port. The air in the room is quickly discharged.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a state in which a poppet valve according to an embodiment of the present invention is attached to a block constituting a hydraulic circuit, and FIG. 2 is an enlarged sectional view showing the poppet inflow restrictor vicinity of the poppet valve. 3 is a sectional view taken along the line AA of FIG.

The poppet valve 20 shown in FIG.
The sliding portion 25a of the poppet 25 having the conical surface 25b at the tip of a is movably fitted into the sliding hole 22a of the cage 22, and the poppet 25 has the conical surface 25b formed on the cage 22 by the urging force of the spring 31. By urging in the direction of contacting the seat 24, the air flows in through the inflow port 32 formed in the block 35, pushes open between the conical surface 25b of the poppet 25 and the seat 24, and serves as an outflow port 33a. .About.33e (33b to 33e, see FIG. 3) controls the pressure of oil, which is a fluid.

The poppet 25 forms a gap 41 between the conical surface 25b and the sliding portion 25a, which is slightly smaller than the outer diameter of the sliding portion 25a and forms a gap 41 between the poppet 25 and the sliding hole 22a. A portion 25c (enlarged and clearly shown in FIG. 2) is provided.

Further, the gap 4 is formed in the gap forming portion 25c.
Inflow throttles 43a, 43 for connecting 1 to the spring chamber 37 in which the spring 31 inside the poppet 25 is provided.
A plurality of c and the like (which will be described later in detail in FIG. 3) are formed. The cage 22 is fixed to the retainer 23 by screwing a threaded portion formed on the outer periphery on the one end side into a female threaded portion of the retainer 23.

A spring receiver 26 is screwed into a screw hole formed in the center of the retainer 23, and a lock nut is attached to an adjusting screw portion 27 formed outside the portion of the spring receiver 26 protruding from the retainer 23. 28 and a cap nut 29 are respectively screwed.

A spring 31 is interposed between the spring receiver 26 and the poppet 25, and the poppet 25 is pressed and urged downward in FIG. 1 by the urging force of the spring 31. In this embodiment, as shown in FIG. 3, the outlets 33a to 33 of the cage 22 serving as the outflow passages.
e, for example, the outer peripheral surface of the cage 22 is divided into five in the circumferential direction (5
Five pieces are formed at the positions to be distributed.

The poppet valve 20 thus constructed is
The male screw portion 23a formed on the outer peripheral surface of the lower side of the retainer 23 in FIG. 1 is used by being fixed by being screwed into a female screw portion formed on a block 35 constituting a hydraulic circuit, for example.

When the operation of the hydraulic circuit is started in this state, oil as a fluid flows into the poppet valve 20 from the inflow port 32 of the block 35, and the oil is responsive to the set pressure by the urging force of the spring 31. Passing between the conical surface 25b of the poppet 25 whose opening is controlled and the seat 24,
Each of the outlets 33a to 33e flows out to the outflow port 36 through the outflow chamber 34.

At this time, a state in which a portion where the pressure rises and a portion where the pressure does not rise are formed in the gap 41 formed by the gap forming portion 25c will be described with reference to FIG. Figure 3
Five outflow ports 33a to 33e are formed in the cage 22 at equal intervals in the circumferential direction, and the gap forming portion 25 of the poppet 25 is formed.
2 shows an example in which the inflow throttles 43a to 43c are respectively formed in the circumferential direction at three equally divided positions. In order to explain that there is a portion where the pressure rises and a portion where the pressure does not rise in the gap 41, FIG. The state cut along the line AA is shown.

The oil flowing from the inflow port 32 of FIG. 1 along the conical surface 25b of the poppet 25 flows to the portion sandwiched between the wall surface of the sliding hole 22a of the cage 22 and the wall surface of the gap forming portion 25c of the poppet 25. If you hold in, the pressure in that part will rise. Therefore, in FIG.
The pressure rises in the gap 41 near 3b and 43c.

However, the gap 41 near the inflow throttle 43a
As shown in the figure, since the outlet 33a and the inflow throttle 43a have a corresponding positional relationship in the circumferential direction, the oil that flows in flows out to the outlet 33a as it is and does not enter the gap 41. There is no. In this case, on the contrary, the inflow throttle 43a functions as an outflow throttle that allows the oil in the spring chamber 37 to flow out through the gap 41 to the outflow port 33a.

That is, the outlets 33a to 3 shown in FIG.
In the positional relationship between 3e and the inflow throttles 43a to 43c, the inflow throttles 43b and 43c function as the original inflow throttles, the inflow throttle 43a functions as the outflow throttles, and the oil in the spring chamber 37 is discharged. do.

Due to this oil flow, the poppet valve 20 is not used until it is attached to the block 35 constituting the hydraulic circuit after the assembly is completed as shown in FIG. However, when the operation of the hydraulic circuit is started, the air in the spring chamber 37 is quickly discharged.

As is apparent from FIG. 3, the numbers, sizes, and positions of the outflow ports and the inflow throttles (a part of which functions as outflow throttles) can be appropriately designed.
FIG. 4 is a cross-sectional view of a poppet valve showing another embodiment, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals.

This embodiment is different from the embodiment of FIG. 1 in that a slit groove 38 and an outflow restrictor 44 are added, and when the poppet valve 20 'is vertically mounted as shown in FIG. 4, it is used. The outflow throttle 4 for exhaust that effectively functions to quickly exhaust the air in the spring chamber 37 to the outside.
4 is provided on the retainer 23.

That is, the retainer 23 is formed with an outflow throttle 44 which connects the spring chamber 37 to the outflow chamber 34 communicating with the outflow ports 33a to 33e and the outflow port 36 through the slit groove 38 formed in the retainer 23. .
The slit groove 38, as shown in FIG.
It is a slit-shaped groove formed by shaving a part of the screw surface of the male screw portion 23a formed on one end side of the outer peripheral surface thereof in the vertical direction in the figure to a predetermined depth.

The sizes of the inflow throttles 43a to 43c, the outflow throttle 44, and the slit groove 38 are such that the air in the spring chamber 37 can be discharged to the outside and the damping property for suppressing the vibration of the poppet 25 can be suppressed. And decide.

That is, in the embodiment of FIG. 1, the inflow throttle 4
3a to 43c (43b and 43 in the position of FIG. 3)
c) causes the oil to flow into the spring chamber 37 and to flow out from the inflow throttle (43a in the position of FIG. 3) at a position that functions as an outflow throttle, so that the pressure (back pressure) in the spring chamber 37 is reduced. In order to enhance the damping effect against the vibration of the poppet 25, the outflow restrictor 44 and the slit groove 3 are further provided in the embodiment of FIG.
The damping effect is enhanced while allowing the oil in the spring chamber 37 to flow out from the valve 8.

According to the experimental results, the inflow throttles are holes having a diameter of 1 mm, and three (43a to 43c) are circumferentially spaced on the peripheral surface of the gap forming portion 25c of the poppet 25.
When one of the outflow restrictors 44 is formed as a hole having a diameter of 1 mm, the resistance of the tank line to which the outflow port 36 is connected is high, and the pressure and pressure fluctuation in that part are large, so that the interference vibration of the poppet 25 occurs. Even in the case of a hydraulic circuit in a condition where it is easy to operate, both the air releasing property and the damping property can be improved, and the vibration of the poppet 25 can be reduced, which is effective.

The poppet valves 20 and 20 'of FIGS. 1 and 4 are shown.
When changing the control pressure of the fluid, as in the poppet valve 1 described with reference to FIG. 11, the cap nut 29 is removed, the lock nut 28 is temporarily loosened, the spring receiver 26 is rotated, and the retainer 23 is rotated. The vertical movement is adjusted in FIGS. 1 and 4.

Then, the lock nut 28 is fixed again at a position where the spring force of the spring 31 reaches a desired value to fix the spring receiver 26, and the adjusting screw portion 27 of the spring receiver 26 is provided with a cap nut for preventing erroneous operation. Install 29 to prevent the spring receiver 26 from being accidentally rotated.

As shown in FIG. 6, the outer peripheral surface of the poppet 25 is in the vertical direction (moving direction of the poppet 25) as shown in FIG.
A slit groove 21 having a predetermined depth along the gap is formed by partially forming a predetermined interval in the circumferential direction instead of slightly reducing the outer diameter of the sliding portion 25a of the poppet 25. May be formed, and the gap 41 may be formed between the gap forming portion and the sliding hole 22a shown in FIGS.

FIG. 7 is a sectional view showing a check valve which is a poppet valve having a high cracking pressure to which the present invention is applied. In this check valve 50, a sliding portion 55a of a poppet 55 having a conical surface 55b is movably fitted in a sliding hole 52a formed in a cage 52, and the poppet 55 has a spring 5 whose one end is pressed by a spring receiver 56.
The urging force of 1 urges the conical surface 55b in the direction of coming into contact with the seat 54 of the cage 52.

The poppet 55 has a gap forming portion 55c formed between the conical surface 55b and the sliding portion 55a and having a diameter slightly smaller than the outer diameter of the sliding portion 55a. A gap 61 is formed between the sliding hole 52a and the sliding hole 52a.

Further, the gap 6 is formed in the gap forming portion 55c.
An inflow throttle 63 that connects 1 to the spring chamber 67 in which the spring 51 inside the poppet 55 is provided is formed, and the spring chamber 67 is connected to the outflow port 66 from the outflow chamber 65 via the oil passage 68 formed in the cage 52. An outflow restrictor 64 that communicates with the cage 52 is provided.

When this check valve 50 is used, the cage 52 is fixed to the block 60 as a single valve by bolting. Therefore, in this state, the oil that flows in from the inflow port 62 pushes open the poppet 55 that is in pressure-contact with the seat 54 and opens the poppet 55.
It flows out to the outflow port 66 through between the conical surface 55b of the sheet and the seat 54, and also flows in between the gap forming portion 55c forming the gap 61 and the sliding hole 52a. Therefore, the pressure in the gap 61 increases.

As a result, the inflow throttle 63 is introduced from the gap 61.
Through which the oil flows from the spring chamber 67 through the outflow throttle 64 to the oil passage 68 to the outflow chamber 65 and the outflow port 66. Due to this oil flow, even if air is first introduced into the spring chamber 67 of the check valve 50, it is promptly changed immediately after the start of operation as in the case of the poppet valves 20 and 20 'of FIGS. It can be discharged from the spring chamber 67.

Therefore, the poppet valve 2 of FIG. 1 and FIG.
As in the case of 0 and 20 ', if the operation of the hydraulic circuit equipped with the check valve 50 is started, the check valve 50 can be promptly operated in a normal state in which vibration and noise do not occur.

FIG. 8 is a sectional view showing an example of a check valve in which the outflow throttle is formed on the conical surface portion of the poppet.
The parts corresponding to those in FIG. 7 are designated by the same reference numerals. This check valve 70 is the poppet 5 of the check valve 50 of FIG.
5, the position where the outflow throttle 74 is provided is the poppet 55 '.
The only difference is that the oil passage 68 is eliminated by providing it on the conical surface portion 55d in which the conical surface 55b is formed.

Outflow throttle 74 on the conical surface 55b
The position of the poppet 55 'is as shown by the arrow A in FIG.
The flow of oil that passes through between the conical surface 55b and the seat 54, enters the gap 61, collides with the wall surfaces of the gap forming portion 55c and the sliding hole 52a, and bounces back (shown by the arrow B in the figure). Position it so that it is not affected by.

That is, the pressure of the outlet portion of the outflow throttle 74, which releases the oil in the spring chamber 67, which communicates with the outflow chamber 65, is adjusted by the gap forming portion 55c forming the gap 61 and the sliding hole 5.
The position of the outflow throttle 74 should be sufficiently separated from the gap 61 so that the pressure does not rise due to the dynamic pressure of the oil that collides with the wall surface of 2a and bounces off. In this way, the outlet portion of the outflow throttle 74 has almost the same pressure as the outflow chamber 65 because the pressure rise due to the collision flow of the fluid that enters the gap 61 and collides against the wall and bounces off is almost eliminated.

Therefore, the pressure of the outlet portion of the outflow throttle 74 communicating with the outflow chamber 65 becomes lower than the pressure in the spring chamber 67 increased by the collision flow. Even if air is present, it can be quickly discharged to the outflow chamber 65.

The shape of the outlet of the outflow throttle 74 is
As long as the flow of the fluid along the conical surface 55b of the poppet 55 'is not significantly disturbed, a chamfer 75 of a constant width passing therethrough is provided at the outlet portion 74a of the outflow throttle 74 of the conical surface 55b as shown in FIG. It may be formed over the entire circumference. Further, as shown in FIG. 10, the chamfer 76 may be formed only on the outlet portion 74 a of the outflow throttle 74.

[0053]

As described above, when the hydraulic circuit is constructed by using the poppet valve according to the present invention, the air contained in the spring chamber of the poppet valve at the initial stage is immediately after the operation of the hydraulic circuit. Because it quickly escapes to the outside,
Immediately after starting operation, you can start normal operation without vibration or noise.

Further, since the inflow throttle is provided in the portion for allowing the fluid to flow into the spring chamber and the outflow throttle is provided in the portion for allowing the fluid to flow out from the spring chamber, the fluid that has flowed into the spring chamber is gradually discharged by the outflow throttle. By doing so, the pressure in the spring chamber (back pressure) can be increased, so even if the poppet tries to vibrate due to pressure changes, the damping effect works, and it is possible to prevent that vibration, and to prevent humming (squeaking), etc. The generation of abnormal noise can also be prevented.

Further, even if pressure fluctuations occur in the tank line communicating with the outflow passage, the pressure fluctuations can be prevented from acting on the spring chamber by the outflow throttle.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a poppet valve according to an embodiment of the present invention is attached to a block forming a hydraulic circuit.

FIG. 2 is a sectional view showing the vicinity of an inflow throttle of the poppet valve in an enlarged manner.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view of a poppet valve showing another embodiment.

5 is a retainer 2 provided on the poppet valve of FIG.
3 is a front view showing a part of a retainer 23 for explaining a slit groove 38 formed in a male screw portion 23a of No. 3 of FIG.

6 is a front view showing an example in which a gap forming portion of a poppet 25 provided in the poppet valve of FIGS. 1 and 4 is formed by a slit groove 21. FIG.

FIG. 7 is a sectional view showing an embodiment in which the present invention is applied to a check valve which is a high cracking pressure poppet valve.

8 is a cross-sectional view showing an embodiment in which an outflow throttle in the check valve of FIG. 7 is formed on a conical surface portion of a poppet.

9 is a front view showing an example in which a chamfer 75 having a constant width is formed over the entire circumference at an outlet portion of an outflow throttle 74 formed in the poppet 55 'of the check valve in FIG.

FIG. 10 is a front view showing an example in which a chamfer 76 is partially formed only on the outlet portion of the outflow throttle 74 of the poppet 55 ′ with one side in a sectional state.

FIG. 11 is a cross-sectional view illustrating a conventional direct acting poppet valve.

[Explanation of symbols]

 20, 20 ': Poppet valve 22, 52: Cage 22a, 52a: Sliding hole 24, 54: Seat 25, 55, 55': Poppet 25a, 55a: Sliding portion 25b, 55b: Conical surface 25c, 55c: Gap Forming part 26, 56: Spring receiver 31, 51: Spring 33a to 33e, Outflow port (outflow path) 37, 67: Spring chamber 41, 61: Gap 43a to 43c, 63: Inflow throttle 44, 64, 74: Outflow throttle 50, 70: Check valve (poppet valve) 55d: Conical surface portion 65: Outflow chamber (outflow passage)

Claims (3)

[Claims] 1. A sliding part of a poppet having a conical surface at the tip of the sliding part is movably fitted in a sliding hole of a cage,
By urging the poppet in the direction in which the conical surface contacts the seat formed in the cage by the urging force of the spring, the fluid that pushes open between the conical surface of the poppet and the seat and flows out into the outflow passage. In the poppet valve configured to control the pressure of, the diameter between the conical surface of the poppet and the sliding portion is slightly smaller than the outer diameter of the sliding portion, or in the sliding direction of the poppet. A gap forming portion is formed to partially form a groove along the sliding hole to form a gap, and the gap is communicated with the spring chamber inside the poppet in which the spring is provided. A poppet valve, characterized by forming an inflow throttle and providing an outflow throttle for communicating the spring chamber with the outflow passage. 2. The poppet valve according to claim 1, wherein the outflow throttle is formed in a conical surface portion of the poppet. 3. The poppet valve according to claim 1, wherein a plurality of the outflow passages are formed in the cage at intervals in the circumferential direction, and a plurality of the inflow throttles are formed in the gap forming portion. Are arranged so that one of them always corresponds to one of the outflow passages so that a fluid flow working region from the spring chamber to the outflow passage is formed, and a part of the inflow restrictor forms the outflow restrictor. A poppet valve characterized in that it also serves as a doublet.