JPS6231702A - Pneumatic pilot relay - Google Patents

Abstract

PURPOSE:To rationalize input-output characteristics, by providing a bias room behind a pressure receiving element, and introducing pressure proportional to the magnitude of supply air pressure into this bias room. CONSTITUTION:In a non-bleed type pilot relay 1, pressure Px proportional to the magnitude of supply air pressure Psup is introduced via pressure dividing mechanism 31 into a bias room 30 which puts opposite directional pressure against the movable direction of an upper diaphragm 10 which operates as a pressure receiving element being moved by an input air pressure signal Psup. Thereby, bias pressure against the diaphragm 10 can be made variable proportional to the magnitude of the supply air pressure, so that input-output characteristics can be rationalized and working characteristics also can be stabilized considering loop gain as almost equal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a pneumatic pilot relay suitable for use as an amplifier for amplifying pressure or flow rate in various pneumatic instruments, for example.

[Conventional technology]

Pneumatic pilot relays, which are attached to pneumatic instruments and are used as pneumatic signal amplifiers, are classified into non-bleed type and bleed type, depending on whether the air consumption is discontinuous or continuous in the operating state. They are broadly classified into two types and are used depending on the need.

As an example, a conventional non-bleed type pneumatic pilot relay will be briefly explained using FIG. Atmospheric communication room 5. and a human power chamber 6, and among these chambers, the supply pressure chamber 3 and the output chamber 4
The output chamber 4 and the atmosphere communication chamber 5 communicate with each other through a through hole 8 bored in the internal partition wall 7, the output chamber 4 and the atmosphere communication chamber 5 communicate with each other through a lower diaphragm 9, and the atmosphere communication chamber 5 and the human power room 6 communicate with each other through a lower diaphragm 9. They are each defined by an upper diaphragm lO. An opening 11 is formed in the center of the lower diaphragm 9, and the opening 11 in parentheses is located in the upper and lower diaphragm 1O.
A hole 12a is opened into a cylinder 12 which is interposed between the cylinders 19 and connects them, and is further bored on the side of the cylinder 12. A hole 12a is opened into the atmosphere communication chamber 5.

13.14 is the opening 1 of the F section diaphragm 9 mentioned above.
1. A valve body that opens and closes the through hole 8 of the partition wall 7. These valve bodies 13 and 14 are provided at both ends of a valve shaft 15 that is disposed 6 through the through hole 8, and are integrally connected to each other. The valves are arranged in series to form a valve/operate valve, and are normally biased in the closing direction (upward in the figure) by a bias spring 16 disposed within the output chamber 4. In the figure, P sup is the supply air pressure introduced into the supply pressure chamber 3 through the intake port 17, and Pn is the nozzle flapper mechanism of a pneumatic instrument or the like introduced into the input chamber 6 through the input port 18. 20, Pout is the air pressure output output from the output chamber 4 through the output port 19, and Pa is the air pressure output when the exhaust port 5a of the atmospheric communication chamber 5 is opened. This is the atmospheric pressure. Furthermore, 13a in the figure is a holding spring that holds the valve body 13 as a poppet valve.

Further, in the figure, 21 is a nozzle to which the supply air pressure P sup is guided through a fixed throttle R, 22 is a flapper 'C' which is oscillated by a displacement signal opposite to this, and X f is a gap between the nozzle and flapper. be.

In such a configuration, when the nozzle back pressure Pn as a human air pressure signal input to the input chamber 6 increases, the two-part diaphragm 10 is suppressed and moved in the t direction,
As a result, the door diaphragm 9 is lowered through the cylindrical body 12, and as a result, the exhaust valve constituted by the jt seat on the side edge of the opening ll and the seating portion of the valve body 13 is closed, while the The intake valve constituted by the valve seat on the side edge of the through hole 8 of the wall 7 and the seating portion of the valve body 14 is opened, and the supply air pressure P sup passes through the supply pressure chamber 6 and the output chamber 5 to the air pressure output P out is output as

Further, when the nozzle back pressure Pn as a human air pressure signal to the input chamber 6 is reduced, the upper diaphragm 10 returns to the L direction, and further the valve body 13 constituting the plunger valve
, 14 are moved in one direction by the urging force of the bias spring 16, the aforementioned intake valve is closed, and the exhaust valve is opened, and the air pressure on the output port 19 side of this pilot relay passes through this exhaust valve. It is discharged into the atmosphere, thereby also reducing the pressure of the air pressure output P out.

Therefore, in the non-bleed type pilot relay 1 having such a configuration, depending on the position of the valve body 13° 14 constituting the poppet valve corresponding to the nozzle back pressure Pn,
It was possible to obtain a pneumatic output P out proportional to the nozzle back pressure Pn.

[Problem that the invention seeks to solve]

By the way, in the pneumatic pilot relay I having the above-mentioned configuration, the relatively low human power required from the pneumatic instrument is generally 0.2 to 1. OKg/c■2 is given by the width of FS, and the supply air pressure is 1.
4Kg/cm Q FS is given.

However, on the other hand, when used in instruments such as control valve positioners that require large pressure as valve driving force, the output of pilot relay l is 7 kg.
/c■2 FSt- may be required; in this case,
The air pressure P sup supplied to this pilot relay 1 is also
It is necessary to apply a correspondingly high pressure.

However, in the above-mentioned case, simply increasing the supply air pressure P
output P per flapper gap (given as xr)
While out can be increased, the supply air pressure P s
By increasing the pressure up, the nozzle back pressure P n (=
1/ (R/Rn) + l; where Rn is the variable aperture formed by the nozzle/flapper gap) also increases, so the nozzle-flapper gain (K=R/Rn) when viewed per the same nozzle back pressure Pn ) also changes significantly, and in the pilot relay 1 with the conventional configuration, a problem arises in that this change in gain affects the gain of the entire loop.

In other words, the loop gain is generally understood as the magnitude of the take-out signal in the feedback loop. Therefore, the supply air pressure P s as described above
When up changes, the amount of change in nozzle back pressure Pn and pneumatic output Pout is l/(l+K), so in order to suppress the influence on pneumatic output Pout, it is necessary to increase gain K. However, if this gain K is too large, the entire system tends to become unstable and automatic oscillations occur.2There is a demand that the gain of the pilot relay l, which has been set properly, should not be changed. be.

For this reason, in the past, various demand pressures were dealt with by measures such as replacing the bias spring 16 in the pilot relay 1 with one with a different l511G force, but with this configuration, the number of models was increased unnecessarily. It has the disadvantage of being easily stored away, which is a big problem in practical terms. It is also conceivable to configure the bias spring 16 as described above to be variably adjustable, but this would not only be troublesome to operate, but would also pose structural problems, making it difficult to actually employ it.

These problems are also the same in the bleed type pilot relay 1 as shown in FIG. 5, and it is desired to take some measures that can eliminate these problems.

[Means for solving problems]

In order to meet such demands, the pneumatic pilot relay according to the present invention is provided with a bias chamber that applies a pressure ′j in the opposite direction to the movement direction of the receiving pressure f-, which is moved by an input air pressure signal. A pressure proportional to the magnitude of the supplied air pressure is introduced into the chamber via a pressure dividing mechanism.

[Effect]

According to the present invention, by using the bias chamber that applies a pressure in the opposite direction to the input air pressure signal to the pressure receiving element, the bias applied to the pressure receiving element can be changed by fIf in proportion to the magnitude of the supplied air pressure.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 shows an embodiment of the pneumatic pilot relay according to the present invention applied to a non-bleed type.
In this figure, parts that are the same as or similar to those in FIG.

Now, according to the present invention, in the non-bleed type pilot relay 1 having the above-described configuration, the input air pressure signal P
A bias chamber 301 is provided to apply pressure in the opposite direction to the direction of movement of the upper diaphragm 10 as a pressure receiving element moved by sup, and a partial pressure Px proportional to the magnitude of the supply air pressure P sup is provided in the bias chamber 30. Mechanism 31 (Rt.

It is characterized in that it is introduced via R2). In the figure, 32 is a small diaphragm that defines a bias chamber 30 formed between the input chamber 6 and the atmosphere communication chamber 5 on the side of the atmosphere communication chamber 5, and 33 is the pressure dividing mechanism 31.
The partial pressure from P! This is an introduction hole for introducing the inside of the bias chamber 30 into the bias chamber 30.

Here, - the partial pressure (Piaska) Pi supplied into the bias chamber 30 described above is 1 partial pressure 414131, so P x = R2 / Rs + R2 * P s
up* & fist 5(f).

Furthermore, the force balance equation within the pilot relay 1 is P nI
IA+P xll a=P x*A+P auto a
...sha■ However, A: Area of the upper diaphragm lo a: Area of the small diaphragm 32, so that P x = P no K-P out/K -1m With a gain of 1, K = A/a) is derived.

The pilot relay l according to the present invention has the area A of the large and small diaphragms 10.9 compared to the conventional example.

When manufactured with equal a, Pn is obtained from the force balance equation in the conventional example P no A = P outs a + f (f is the elastic force of the bias spring 16), and by substituting this into the above-mentioned (Jun equation), , it is possible to calculate the desired partial pressure Pg.If such a partial pressure Px is determined, it is obvious that R1 and R2 can be selected from the above equation 0.

According to the present invention having such a configuration, the predetermined output P o
Due to the need to obtain the air supply pressure P sup, when the supply air pressure P sup is increased, the nozzle back pressure Pn and the air pressure output P out are not only increased in response to changes in the supply air pressure P sup, but also the output P out is increased. , Bobet 1 Jr (13, 1
The piascus can be automatically changed according to changes in the supply air pressure so that the movement (4) does not substantially change, thereby making it possible to change the input/output characteristics to A+E. Such input/output characteristics a, btl are shown in FIG. 2 and can be easily understood. In addition, in this case, changing the piascus as in the present invention changes the nozzle/flapper gain when the supply ρ pressure P sup is low (characteristic curve C
) can be made substantially equal to the gain G3 when the gain is increased to ]F (characteristic curve d), and the advantage is obvious compared to the gain G3 when the bias signal is not changed.

The effects of such a configuration are also achieved in the bleed type pneumatic pilot relay 1 shown in FIG.
They are similar and can be easily understood. Here, the configuration and the like are given the same numbers as those of the embodiment described above, and detailed explanation thereof will be omitted.

Note that the present invention is not limited to the structure of the embodiment described above, and the shape, structure, etc. of each part may be modified or changed as appropriate. For example, in the above-mentioned embodiment, the bias chamber 30 is formed in place of the conventional bias spring, but the bias chamber is also provided in conjunction with the spring, and thereby the bias spacing can be changed according to the supplied air pressure. It will be easily understood that it is also possible to obtain

Further, in the embodiment described above, the resistor R2 constituting the voltage dividing mechanism 31 may be a variable resistor so that the bias voltage can be adjusted as necessary. In this way, it is effective for improving responsiveness in the field and preventing hunting, and it is also possible to change the loop gain as necessary.

〔Effect of the invention〕

As explained above, according to the pneumatic pilot relay according to the present invention, a bias chamber is provided that applies pressure in the opposite direction to the direction of movement of the pressure receiving element that is moved by an input air pressure signal, and the supply air pressure is applied to the bias chamber. Although the structure is simple and inexpensive, the pressure proportional to the size of the air pressure is introduced through the partial pressure mechanism. It can be automatically varied, and has various excellent effects such as being able to easily output the pneumatic pressure at an appropriate level, and stabilizing the operating characteristics by keeping the loop gain approximately equal.

[Brief explanation of the drawing]

Figure 1 is a book)! 2 is a schematic sectional view showing one embodiment of a non-bleed type pilot relay according to the present invention, FIG. 2 is a characteristic diagram showing its input/output characteristics and nozzle flapper gain characteristics in comparison with the conventional one, and FIG. A schematic sectional view showing an embodiment when applied to a mold, and FIGS. 4 and 5 are schematic sectional views showing a conventional example. l...Pneumatic pilot relay, 3...Supply pressure chamber, 4...Output chamber, 5...Atmospheric communication chamber, 6-
・-・Input room, 9. to... conflict - diaphragm, 13.
14... Valve body (bopetsu [P), 20... Nozzle flapper mechanism, 30... l < I7 chamber, 31...
・Partial pressure mechanism. Patent applicant: Yamatake Honeywell Co., Ltd.
Rihito Yama Yomasaki (and 2 others) Figure 1 Figure 4 Figure S Procedural Amendment Form Gengen 1. Display of the case 1985 Patent Application No. 171227 2, Name of the invention Pneumatic pilot relay 3, Person making the amendment Relationship to the case Patent Applicant name (name)
(666) Yamatake I. Newell Co., Ltd. Name (64)
62) Patent Attorney Tsuchiyama Monthly 1 Masaki 5, Column 6 for detailed explanation of the invention in the specification subject to amendment Contents of the amendment +l) Page 5, line 19 of the specification to page 7, line 3 ``However, the above There is a request that...'' be amended as follows. ``However, in the case described above, simply increasing the supply air pressure P sup will also increase the variable constriction gap formed by the nozzle back and 7 lap gaps.
The nozzle flapper gain (Kn=Pn/Xf, where Xf Fi nozzle flapper gap) when viewed at the same nozzle back pressure Pn level also changes significantly. Therefore, in the pilot relay 1 having the conventional configuration, a problem arises in that this change in gain affects the gain of the entire loop. In other words, it is desirable that the loop gain be as large as possible in order to suppress external disturbances applied to the feedback system, but in a feedback system with a spring mass system,
Due to the relationship with the natural frequency, etc., it is difficult to make it too large, so it is carefully selected. However, on the other hand,
There is a request to keep the gain K of the pilot relay 1 unchanged once it has been set appropriately. ” (2) Same book, page 9, line 14 r PX = R, /R1+ R,
・P sup −・=■”, r Px = Rt/
(R+ + Rt) 'P sup...■''
and correct it. Written amendment to the above procedure (voluntary) 1.1985 Patent Application No. 171227 2. Name of the invention: Pneumatic pilot relay 3. Relationship with the case of the person making the amendment Patent Name of applicant (name ) (666) Yamatake Honeywell Co., Ltd. 5, Detailed description of the invention in the specification subject to amendment, '-(',
(,"□ 6. Contents of correction (1) Details, page d4, line 9 "Supply pressure chamber 6, output chamber 5" is corrected to "supply pressure chamber 3, output chamber 4". (2) Page 5 of the same Line 9 “Input is 0.2 to 1.0 kg/cm
Fs J is "output signal is 0.2~1.0kg/cAJ
and correct it. (3) Delete r FS J on page 5, lines 11 and 15. (4) From line 11 on page 5 to line 3 on page 7, "However, there is a request for..." as described below. However, in the above case, simply increasing the supply air pressure P3up will also increase the variable restriction formed by the nozzle flapper gap, so when looking at the same nozzle back pressure Pn level, Nozzle flat surface (Kn = Pn / Xf: where X
f (nozzle/flapper gap) also changes significantly. Therefore, in the pilot relay 1 having the conventional configuration, a problem arises in that this change in gain Kn affects the gain of the entire loop. In other words, it is desirable that the loop gain be as large as possible in order to suppress the disturbance applied to the filled pack system, but in a feedback system with a spring mass system,
It cannot be made too large due to the relationship with the natural frequency, etc., so it is carefully selected. However, on the other hand,
There is a request to keep the gain K of the pilot relay 1 unchanged once it has been set appropriately. ” (5) Page 7, line 9 “Mono desu. Insert the following sentence between J and “Also.” "For example, in valve positioners, the supply pressure is often selected arbitrarily in relation to the palf drive pressure, but
At such sites, parts could not be replaced freely, which was a problem. ” (6) Page 5, line 11 r PX=R2/(R,+R,)
−Pgup “””■”, r PX= (Rt/(
R1+R2) IP sup...■''. (7) Same page 10, line 3 r Px=Pn −K−P out
/K -1-...■'', r Rx=(Pn- to -P
out )/(K-1)...■Correct as J. that's all

Claims (1)

[Claims] A bias chamber is provided to apply pressure in the opposite direction to the direction of movement of the pressure receiving element that is moved by an input air pressure signal, and a pressure proportional to the magnitude of the supplied air pressure is introduced into this bias chamber via a pressure dividing mechanism. Features a pneumatic pilot relay.