JP2755912B2 - Pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The internal pressure of a container to maintain the internal pressure at a predetermined pressure (positive pressure) equal to or higher than the external pressure and equal to or lower than the predetermined pressure (negative pressure) equal to or lower than the external pressure is equal to or higher than the predetermined pressure. The present invention relates to a pressure control device for opening an opening provided in a container when the predetermined pressure exceeds the predetermined pressure in a positive or negative direction in accordance with the positive or negative of the pressure, and for closing the opening when the pressure of the container returns to a predetermined value. is there.

[0002]

2. Description of the Related Art Generally, in a facility such as a plant that handles a fluid having a pressure fluctuation, when a pressure exceeds a design pressure due to some abnormality or the like, a pressure wall (such as a pipe, a vessel, etc.) is utilized by utilizing an internal / external pressure difference. A pressure control device for automatically opening an opening provided in the wall) is provided, thereby maintaining pressure or ensuring safety. Conventionally, as this kind of pressure control device, there are a counterweight type and a rupture disk type.

The counterweight type is, for example, shown in FIG.
As shown in FIG. 1, a cylindrical base 1 connected to the opening and a rotating shaft 2 provided outside the base 1 so as to be opened and closed.
And a counterweight 4 for adjusting the gravitational moment of the cover 3 (moment for lifting the cover 3). Is set such that the mass of the counterweight 4 and the like are set such that the moment of the force applied to the counterweight becomes equal to the gravitational moment. In this case, when the pressure difference between the inside and outside exceeds the allowable maximum value, the moment of the force applied to the lid 3 due to the pressure difference overcomes the gravitational moment, and the lid 3 is lifted and opened.

In the rupture disk type, for example, as shown in FIG. 9, the opening 5 is closed with a plate-like body 6 having a fragile structure called a rupture disk. The plate 6 is configured to be torn if it exceeds.

[0005]

The counterweight type has a large pressure loss at the time of opening movement, and in order to obtain a large flow rate, the opening and the lid must be enlarged. There was a problem that the space became large. That is, in the conventional simple counterweight method, the gravitational moment of the lid (valve element) and the counterweight must be set to a magnitude that can withstand the allowable pressure, and the pressure difference exceeds the allowable pressure and the lid is opened. Even if it does, unless the pressure difference is rapidly increasing, the lid is balanced when the lid is opened at a slight angle, and the lid does not open greatly. For this reason, the flow path area obtained by the opening movement of the lid becomes extremely small as the generated pressure difference is small, as compared with the size of the opening, and an abnormal pressure rise of equipment having a very large capacity such as a plant. Or in order to avoid pressure drop with good responsiveness,
There is a disadvantage that the size of the opening must be extremely large.

On the other hand, in the rupture disk type, the rupture disk does not greatly block the flow path after the rupture due to the characteristics of the rupture disk itself. There was a problem that the dispersion was large, and there was a problem that the rupture disk could not be reused, and after the operation was performed, an operation of returning the rupture disk to a new one (return operation) was required.

The present invention solves the above-mentioned drawbacks of the prior art, and opens greatly even when the pressure difference slightly exceeds the set value, thereby reducing the pressure loss and obtaining a large flow rate, and returning after operation. It is an object of the present invention to provide a pressure control device that is easy to use and that can be used repeatedly.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and relates to a pressure control device having the following features.

(1) A pressure control device for opening an opening provided in a container when a pressure difference between the inside and outside of a container exceeds a predetermined value and closing the opening when the pressure difference inside and outside the container returns to a predetermined value. A valve element rotatably supported by a first rotating shaft from a position at which the opening is closed to a fully open position, and the valve element near the closed position via a ratchet mechanism that only allows the valve element to be rotated to the closed position In the limited range at the time, the valve body or a member that rotates in conjunction with the valve body is engaged and pushed when the valve body rotates from the closed position toward the fully open position, and is pushed out of the limited range. A lock arm rotatably supported by a second rotating shaft so as to rotate away from the valve; and a valve element closed by the lock arm when the lock arm is engaged with the valve element or the valve element interlocking member. Locker that produces a first moment pushing in the direction Urging means, a stopper provided so that the lock arm does not rotate beyond the limited range due to the urging force, and a valve element for generating a second moment for returning the valve element to the closed position at any position A biasing means, wherein the lock arm biasing force is applied to the valve body when the sum of the first moment and the second moment when the valve body is near the closed position exceeds a predetermined value. It is set to be equal to the moment of the applied force.

(2) In the pressure control device according to the above mode (1), the valve element biasing means is supported by a horizontal shaft, and rotates in a vertical plane in conjunction with the valve element. A wire rod having one end hung around the peripheral surface of the winding member and the other end hanging down from the peripheral surface, and a weight attached to the hanging end of the wire material. The shape of the peripheral surface of the member is such that the urging moment generated by the weight changes in accordance with a change in the position of the valve body, and the second moment is maintained at a minimum value required for returning the valve body to the closed position. To form a non-arc shape.

[0011]

According to the present invention, first, in a normal state in which no external force is applied, the lock arm is attached to the valve element or a member which rotates in conjunction with the valve element by the urging force of the lock arm urging means and the function of the stopper. Stable in a limited range where it can be engaged. On the other hand, the valve element is stabilized at the closed position where the opening is closed by the valve element urging means. Therefore, in this normal state, the lock arm engages with the valve body or a member that rotates in conjunction with the valve body via the ratchet mechanism, and the urging force of the lock arm urging means is transmitted via the lock arm and the ratchet mechanism. As a result, the valve element is pressed toward the opening by the sum of the first moment by the lock arm urging means and the second moment by the valve element urging means. And
Since the sum of the moments is set equal to the moment of the force applied to the valve body due to the pressure difference that has reached the set value, unless the pressure difference between the inside and outside of the opening (the pressure difference between both sides of the valve body) exceeds the set value. The two moments that urge the valve body in the closing direction overcome the external force due to the pressure difference, and the closed state is maintained.

When the pressure difference exceeds a set value, the moment of the force applied to the valve body overcomes the sum of the moments due to the pressure difference, and the valve body starts to open from the closed position toward the fully open position on the low pressure side. . At this time, the lock arm rotates in one direction by being pushed by the valve body or a member rotating in conjunction with the valve body via the ratchet mechanism, and exceeds the above-described limited range when the valve body moves away from the vicinity of the closed position. As a result, the engagement with the valve body is released. For this reason, at the moment when the valve element leaves the vicinity of the closed position, the first moment is not applied to the valve element, and the moment applied to the valve element is a moment of force for opening the valve element due to a pressure difference, Since only the second moment, which is much smaller than this, is obtained, the valve body rapidly increases the rotation speed and opens greatly to the fully open position.

At this time, once the valve element is opened, the pressure difference between both sides of the valve element decreases, and the value of the moment for opening the valve element also decreases. The valve body is kept large open by being pushed by the flow of the fluid passing through the opening toward the low pressure side, so that the valve does not become a large resistance to the flow of the fluid. . Also, at this time, the lock arm that has been released from the engagement state with the valve body rotates in the other direction until it is stopped by the stopper by the urging force of the lock arm urging means, and automatically returns to the limited range and waits. .

When the fluid flows sufficiently to the low pressure side through the opening and the pressure difference between the inside and outside of the opening disappears, the valve body is in a free state in which no external force is applied to the valve body. To slowly return to the closed position, engage the lock arm waiting in the limited range via the ratchet mechanism, and automatically return to the normal state.

The valve body urging means is composed of a weight attached to a wire suspended from the winding member, and the shape of the peripheral surface of the winding member changes the urging moment in accordance with a change in the position of the valve body. In the case of the non-circular shape, the opening degree of the valve body at the time of operation can be held at a position that is much larger and close to full open.
That is, for example, when the valve element urging means is configured to apply a constant value of urging moment to the valve element, this constant value corresponds to the maximum value or the minimum value of the gravitational moment of the valve element that varies depending on its posture. Depending on the posture of the valve body, the second moment, which is the sum of the urging moment and the gravitational moment, becomes an unnecessarily large value, and the valve body opposes the pressure of the fluid flowing through the opening. May be pushed too close to the closed position and the opening may not be close to full open.
However, with the above configuration, the biasing moment determined by the distance from the horizontal axis of the weight and the peripheral surface is changed in accordance with a change in the gravitational moment of the valve body. Since the moment 2 can always be set to a very small value, even when the pressure difference between the inside and outside of the opening slightly exceeds the set value, the opening during operation can be reliably maintained at the substantially fully opened position.

[0016]

1 is a longitudinal sectional view of a pressure control device according to a first embodiment of the present invention, and FIG. 2 is a front view of the same embodiment. The purpose of this embodiment is to maintain the inside of the apparatus at a predetermined pressure (= negative pressure) equal to or lower than the external pressure. When the internal pressure of the apparatus falls below a predetermined value, the opening is opened to introduce outside air. When the pressure in the apparatus recovers to a predetermined value, the opening returns to the original closed state.

In the drawing, reference numeral 10 denotes a pipe provided with this device, 11 denotes an overhanging portion of the pipe, 12 denotes a side wall of the overhanging portion, and 13 denotes an opening provided on the side wall. The main part of this device is composed of the following parts. Reference numeral 20 denotes a first rotating shaft, and 30 is provided so as to cover the opening 13, and is a valve body that can rotate around the first rotating shaft 20 to open the opening 13 via a support member described later. , 40 is a supporting device for connecting the rotary shaft and the valve body 30, 50 is a biasing device for returning the opened valve body 30 to its original position, 60 is a second rotary shaft, and 70 is a second rotary shaft. A lock arm that is supported and holds the valve body 30 in a closed state, 80 is a ratchet mechanism that engages the lock arm with the valve body 30, and 90 is a lock arm urging means that urges the lock arm 70. .

FIG. 3 is a perspective view of a bracket for mounting the above-mentioned parts. In the figure, 21 is a first bracket, 22 is a second bracket, and 61 is a fourth bracket. The broken arrows indicate the correspondence between the coupling positions. FIG.
The first rotation shaft 20 shown in (1) is disposed parallel and horizontal to the side wall 12 and is attached to a hole at the upper end of the first bracket 21 fixed directly below the opening 13 in the side wall 12.
The first bracket 21 in FIG. 3 is a long frame-shaped one, and the front end of the second bracket 22 is fixed to the rear surface on the lower end side extending below the overhang portion 11, and the rear end of the second bracket 22 is Piping 10 via three brackets 23 (see FIG. 1)
By being fixed to the side, it is firmly fixed to the side wall 12 and the pipe 10. The fourth bracket 6 is provided at the lower end of the first bracket 21 and the lower end of the rear of the second bracket 22.
Elongated holes 24 and 25 are formed respectively for mounting the 1 in a position-adjustable manner.

In FIG. 1, the valve 30 has a circular opening 1.
3 has a disk shape corresponding to the opening 13
Is formed with a flange portion 31 to be fitted on the inner periphery. The valve body 30 is supported by the first rotation shaft 20 via a support member 40, and a position where the flange portion 31 abuts on the periphery of the opening 13 to close the opening 13 (hereinafter, referred to as a closed position).
, Can be rotationally moved to a low pressure side fully open position (a position indicated by a reference numeral 30a in FIG. 1) that does not cause resistance of the fluid passing through the opening 13. In the fully opened position, the shock absorber 32 provided on the lower surface of the overhang portion 11 comes into contact with the shock absorber 32 so that the movement is reduced with less impact.

The center of the valve body 30 is hinged to the distal end of the arm section 42 of the support member 40 by a pin 33, and the angle of the valve body 30 with respect to the arm section 42 can be adjusted by the function of the adjuster 34. Thereby, it is mounted at an angle so as to be in parallel contact with the opening 13 (side wall 12) in the closed position. The adjuster 34 has one end hinged to the valve body 30 and the other end connected to the arm portion 42.
The screw shaft is fixed to the arm portion 42 by moving the screw shaft forward and backward with respect to the arm portion 42, thereby adjusting the angle of the valve body 30. Is what you do. The opening 13
A donut-shaped seal member 35 is attached to the outside of the peripheral edge of, and seals a gap between the opening 13 and the fitting portion of the valve body 30. The sealing member 35 is made of a material having elasticity such as rubber, for example. The sealed state is maintained.

FIG. 4 is a perspective view of the support member 40. The support member 40 is formed at a boss portion 41 through which the first rotation shaft 20 is inserted, an arm portion 42 extending from the boss portion 41 by bending so as not to interfere with the side wall 12, and formed at a rear portion of the arm portion 42. And a wound portion 43. Arm part 4
2 is provided with a through hole 44 through which the screw shaft of the adjuster 34 is inserted, and a hook 45 to which a wire 51 of the valve body urging means 50 described later is attached. Further, a peripheral surface 46 having the boss 41 as a center is formed on the winding portion 43. On the peripheral surface 46, the wire 51 is always arranged in the circumferential direction to prevent a wire 51 described below from slipping and falling. The two wire guides 47 are formed in parallel. At the end (end of the peripheral surface 46) of the winding portion 43, a step portion 48 that engages with a later-described claw member 82 of the ratchet mechanism 80, and a claw guide 49 that extends obliquely from the step portion 48 are provided. Is formed.

In FIG. 1, the valve body urging means 50 includes a winding portion 43 of the support member 40 and a hook 4 at one end.
5 is wound around the peripheral surface 46 of the winding portion 43, and the other end of the wire 51 is suspended from the peripheral surface 46.
And a weight 52 attached to the other end of the wire 51. Here, the weight 52 is composed of a case 53 to which the other end of the wire 51 is attached, and a plate-shaped weight body 54 loaded in the case 53, and by changing the number of stacked weight bodies 54. The weight W1 is adjustable.

The shape of the peripheral surface 46 of the winding portion 43 of the support member 40 is such that the counterclockwise urging moment Ma generated by the weight 52 around the first rotation shaft 20 is caused by a change in the position of the valve body 30. And the moment M2 (second moment) for returning the valve body 30 to the closed position.
Has a non-circular shape so that it is always maintained at a minimum necessary value regardless of a change in the position of the valve body 30. That is,
The clockwise weight moment Mb about the first rotation shaft 20 due to the weight of the valve body 30 and the members such as the support member 40 that rotates integrally with the valve body 30 is such that the valve body 30 moves toward the fully open position. In this case, the distance L1 (the radius of the peripheral surface 46) from the center of the first rotation shaft 20 to the center of the weight 52 increases. Ma (Ma = W1 · L1) also increases, and as a result, a moment M2 (M2 = Ma−Mb) which is a resultant force of moments applied to the valve body 30 and the like by gravity.
Is maintained at a minimum value sufficient to overcome rotational resistance such as friction on the first rotating shaft 20.

The second rotating shaft 60 is provided with a bearing 6 provided on the upper surface of the tip of a fourth bracket 61 shown in FIGS.
By being attached to the second bracket 2, the first bracket 21 is arranged in parallel with the first rotation shaft 20 and inside the lower end of the first bracket 21. Here, the front end of the fourth bracket 61 is attached to the lower end of the first bracket 21 so that the front and rear positions can be adjusted by a long hole 63 formed in the front end and a bolt inserted into the long hole 24 of the first bracket 21. Fixed. Also,
The rear end of the fourth bracket 61 is also adjustable in the front-rear position by a bolt or the like inserted into the long hole 64 formed in the rear end of the fourth bracket 61 and the long hole 25 of the second bracket 22. It is fixed to the lower surface. This allows
The front and rear positions of the second rotating shaft 60 can be adjusted together with the fourth bracket 61.

FIG. 5 is a side view of an engagement portion of the ratchet mechanism 80 between the support member 40 and the lock arm 70. The lock arm 70 is a member having a substantially L-shaped side surface. One linear portion 71 extends toward the lower end of the support member 40, and the other linear portion 72 extends substantially horizontally along the fourth bracket 61. It is supported by the second rotating shaft 60 so as to be freely rotatable at its bent portion in an extended posture. The lock arm 70 has a configuration in which the length of the linear portion 71 and the angle of inclination are set so that the valve 30 is in the vicinity of the closed position including the closed position within a limited range as shown in FIG. 40 can be engaged via a ratchet mechanism 80,
In this engaged state, when the valve body 30 rotates toward the fully open position, the valve body 30 is pressed by this movement and rotates counterclockwise to move away from the limited range.
The lock arm 70 is connected to the fourth bracket 61
A linear portion 72 is attached to a stopper 75 provided on the upper surface on the rear end side.
When the lower surfaces of the end portions are in contact with each other, the rotation range is restricted so that the rotation does not rotate clockwise beyond the limited range.

In this case, the valve body 30 reaches the closed position at a position slightly before the position where the clockwise rotation of the lock arm 70 is restricted by the stopper 75. That is, as shown in FIG. 1, the lock arm 70 is engaged with the support member 40, the valve element 30 is the closed position
When in the position , there is a gap between the linear portion 72 of the lock arm 70 and the stopper 75. The fine adjustment for setting the gap is performed by the fourth bracket 61.
In addition, it is possible to finely adjust the front-back position of the second rotation shaft 60 (the position in the left-right direction in FIG. 1).

The ratchet mechanism 80 allows only the rotation of the valve body 30 to the closed position side (the counterclockwise rotation of the support member 40).
The lock arm 70 is engaged with the support member 40 so as to prevent the valve body 30 from rotating toward the fully open position. In this case, as shown in FIG.
A claw member 82 pivotally supported by a pin 81 inside the distal end of the linear portion 71, and is screwed into the linear portion 71 so as to abut on the claw member 82 and prevent its counterclockwise rotation. The stopper bolt 83 is provided. The claw member 82 has an acute angle so that the front end side engages with the step portion 48 of the support member 40, and the rear end side has a vertically thick shape,
The center of gravity is eccentric to the rear end side (left side in FIG. 5) of the pin 81, so that it is always in the engaged position in contact with the stopper bolt 83 in the free state, and is rotated clockwise (support member) therefrom. It rotates only in the direction that allows the counterclockwise rotation of the counterclockwise direction 40) to exhibit the so-called ratchet effect.
The engagement position needs to be set accurately so that the tip engages with the step portion. In this case, the position can be finely adjusted by changing the screwing amount of the stopper bolt 83. ing.

The lock arm urging means 90 includes a wire 91 having one end attached to the linear portion 70 on the rear end side of the lock arm 70 and the other end hanging down from the gap of the fourth bracket 61. Weight 92 attached to the other end of the
And Here, the weight 92 includes a case 93 to which the other end of the wire rod 91 is attached, and a plate-shaped weight main body 94 stacked in the case 93. By changing the number of stacked weight main bodies 94. The weight W2 is adjustable.

The pressure receiving area A of the valve 30, the distance L 2 from the center of the second rotary shaft 60 to the center of the weight 92, the distance from the center of the second rotary shaft 60 to the engagement position of the ratchet mechanism 80. The distance L3, the distance L4 from the center of the first rotating shaft 20 to the engagement position, the distance L5 from the center of the first rotating shaft 20 to the center of the valve body 30, and the weight W2 of the weight 92
The moment M1 (first moment) generated around the first rotation shaft 20 by the urging force of the lock arm urging means 90 when the valve body 30 is in the vicinity of the closed position and the second moment described above.
Is set to be equal to the moment M3 of the force applied to the valve body 30 by the internal / external pressure difference ΔP (P2−P0) when the pressure P1 in the pipe 10 reaches the set value P0. . That is, M3 = A · ΔP · L5
And M1 = W2 · L2 · L4 / L3, and M1
+ M2 = M3.

Next, the operation of the pressure control device will be described. First, in the normal state where no external force is applied,
By the urging force of the lock arm urging means 90 and the function of the stopper 75, the lock arm 70 is stabilized in the above-described limited range in which the lock arm 70 can be engaged with the support member 40. On the other hand, the valve element 30 is stabilized at the closed position where the opening 13 is closed by the valve element urging means 50. Therefore, in this normal state, the lock arm 70 is engaged with the support member 40 via the ratchet mechanism 80, and the urging force of the lock arm urging means 90 is transmitted to the valve 30 via the lock arm 70 and the ratchet mechanism 80. As a result, the valve element 30 has a first moment M1 by the lock arm urging means 90 and a second moment M by the valve element urging means 50.
2 and (M1 + M2). Then, as described above, the sum of the moments (M
1 + M2) is set to be equal to the moment M3 of the force applied to the valve body 30 by the pressure difference ΔP when the pressure P1 in the pipe 10 reaches the set value P0, so that the pressure P1 in the pipe 10 is set to the set value P0 And the internal and external pressure difference (P
If (2-P1) does not exceed ΔP, the two moments (M1 + M2) for urging the valve body 30 in the closing direction are the moments M (A · (P2−) due to the pressure difference (P2−P1).
The closed state is maintained over P1) and L5).

Then, the pressure P1 in the pipe 10 becomes equal to the set value P.
0, the moment of the force applied to the valve body 30 due to this pressure difference is the sum of the moments (M1 + M
Overcoming 2), the valve body 30 starts rotating from the closed position toward the fully open position on the low pressure side. At this time, the lock arm 70
Is rotated leftward by being pushed by the support member 40 via the ratchet mechanism 80, and as shown by a chain line (reference numeral 71a) in FIG. Exceeding, it is disengaged from the engagement state with the valve body 30 (support member 40). For this reason, at the moment when the valve element 30 leaves the vicinity of the closed position, the first moment M1 is not applied to the valve element 30 and the moment applied to the valve element 30 is a moment for opening the valve element 30 due to the pressure difference. M (M> M
3) and the significantly smaller second moment M
Since only 2 is provided, the valve body 30 rapidly increases the rotation speed and opens greatly to the fully open position indicated by reference numeral 30a in FIG.

At this time, once the valve element 30 is opened, the pressure difference between the two sides of the valve element 30 is reduced, and the value of the moment M for opening the valve element 30 is also reduced. The valve element 30 is a small one for returning the valve element 30 to the closed position in the absence state, so that the valve element 30 is maintained in a large open state by being pushed by the flow of the fluid passing through the opening toward the low-pressure side. It does not create a large flow resistance.

Particularly in the case of the present embodiment, the valve body urging means 50
Consists of a weight 52 attached to a wire 51 hanging down from the winding portion 43, and a peripheral surface 46 of the winding portion 43.
Has a biasing moment M according to a change in the position of the valve body 30.
a is changed so that the second moment M2 is always set to an extremely small value regardless of the position of the valve element 30. It can be surely held at a substantially full open position.

At this time, the lock arm 70 disengaged from the engagement with the valve body 30 is provided by the lock arm urging means 9.
It turns rightward until it is stopped by the stopper 75 by the urging force of 0, and automatically returns to the end of the limited range and waits.

Then, when the fluid sufficiently flows to the low pressure side through the opening 13 and the pressure difference between the inside and outside of the opening disappears, the valve body 30 is in a free state in which no external force is applied. The urging moment Ma of the valve body urging means 50
, The support member 40 is slowly returned to the closed position by the second moment M2, and the support member 40 is engaged with the lock arm 70 waiting in the limited range via the ratchet mechanism 80, and automatically returns to the normal state. I do. At this time, as the support member 40 rotates, the claw guide 49 of the winding portion 43 first comes into contact with the claw member 82 of the ratchet mechanism 80, and the claw member 82 is rotated slightly clockwise to rotate the support member 40. When the stepped portion 48 comes to the tip position of the claw member 82,
The claw member 82 rotates counterclockwise with its own weight and engages with the step portion 48.

Thus, according to the above pressure control device,
The resistance (pressure loss) due to the valve body 30 during operation can be made almost zero, and after the pressure adjustment is completed, the valve automatically closes and can be used repeatedly thereafter. Therefore, even in large-capacity facilities, pressure adjustment can be performed reliably and at high speed to minimize the damage caused by abnormal pressure with high reliability, and a return operation is not required to reduce human operation costs and save labor. Can be planned.

FIG. 6 is a longitudinal sectional view of a pressure control device according to a second embodiment of the present invention, and FIG. 7 is a side view of the second embodiment. In this embodiment, the internal pressure of the apparatus is equal to or higher than the external air pressure at a predetermined pressure (= positive pressure).
When the internal pressure is higher than the predetermined pressure, the valve is opened and the gas inside is released to the outside.When the internal pressure returns to the predetermined value, the valve is opened. The body returns to its original position.

In this embodiment, each part is moved in the manner shown in FIG. 1 so that the direction in which the valve element opens, the direction in which the lock arm engages, or the direction of the biasing moment of each biasing means are reversed. Thus, it is configured to be substantially symmetrical. in this case,
Wound part 4 of support member 40 constituting valve body urging means 50
In order to prevent 3 from interfering with the wall of the pipe, the arm portion 42 of the support member 40 and the winding portion 43 are separate parts,
The first rotating shaft 20 is extended to the near side, and the valve body urging means 50 is disposed on the near side of the arm portion 42. That is,
The arm part 42 and the winding part 43 are integrated by the interposition of the first rotating shaft 20, and move integrally.

In each of the above embodiments, the first rotating shaft also functions as a support shaft for the winding member of the valve body urging means. In this case, the position of the valve body urging means can be set freely. Further, the first rotation axis and the second rotation axis do not necessarily have to be horizontal. For example, it is also possible to adopt a structure in which the first rotating shaft is arranged in the vertical direction and the valve body is horizontally rotated to open and close. In this case, if the supporting shaft of the wrapping member is separate, Only the shaft is horizontal and is linked to the first rotation shaft, so that the configuration of the valve body urging means can be composed of a winding member having a non-circular peripheral surface and a weight as described above. In addition, if the valve element urging means and the lock arm urging means are constituted by those not relying on gravity (for example, those constituted by coil springs or the like),
It is easy to arrange the first rotation axis and the second rotation axis vertically.

In the first embodiment, the lock arm is engaged with the support member 40 for supporting the valve element. However, as in the second embodiment, the lock arm is interlocked with the valve element (first rotary shaft). It is also possible to provide a winding portion or another separate member, and engage this member with the lock arm. Further, an engagement portion (an element corresponding to the step portion 48 in the above embodiment) may be provided on the valve body itself, and the lock arm may be directly engaged with the valve body.

Further, in the above embodiment, the lock arm 70
The valve body 30 reaches the closed position at a position slightly before the position where clockwise rotation of the valve 30 is restricted by the stopper 75, and the lock arm 70 is
When the valve body 30 is in the closed position by engaging with the lock arm 70, there is a gap between the lock arm 70 and the stopper 75. However, the present invention is not limited to this, and the lock arm 70 is moved to the stopper 75 slightly before the valve body 30 reaches the closed position.
, That is, the valve body 30 is completely opened
When it is in the closed position after being joined to the peripheral edge of the support member 40, there may be a configuration in which there is a slight gap between the claw member 82 of the ratchet mechanism 80 and the step portion 48 of the support member 40. By doing so, the return operation after the valve opening operation is performed smoothly. That is, in the case of the above-described embodiment, the lock arm 70 is rotated counterclockwise from the position waiting at the time of opening the valve (the position contacting the stopper 75) against the lock arm urging means 90 during the return operation by the gap. However, in this case, such an operation of the lock arm 70 at the time of the return operation becomes unnecessary. In this case, the urging force of the lock arm urging means 90 starts to work after the valve element 30 is slightly opened, but the seal member 35 is connected to the valve element 30 as described above.
Keeps the sealed state even if it moves slightly from the closed position to the fully open position, so that there is no problem in the sealing performance.

[0042]

According to the pressure control device of the present invention, the resistance (pressure loss) due to the valve body during operation can be reduced remarkably as compared with the conventional counterweight type or the like, and the pressure adjustment is completed. Later, it closes automatically and can be used repeatedly. Therefore, it is possible to achieve the effect of such may be minimized reliably damage from pressure abnormality performs pressure control reliably and faster in large-capacity equipment, personnel and the required return movement <br/> Operation costs can be reduced and labor can be saved.

In particular, the valve body urging means comprises a weight attached to a wire hanging down from the winding member, and the shape of the peripheral surface of the winding member changes the urging moment in accordance with a change in the position of the valve body. In the case of a non-circular shape that can be changed, the degree of opening of the valve body during operation can be maintained at a position close to full opening, and the resistance (pressure loss) due to the valve body can be reduced to almost zero. Can be performed even faster.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a pressure control device according to a first embodiment of the present invention.

FIG. 2 is a front view of the embodiment.

FIG. 3 is a perspective view of a bracket used in the embodiment.

FIG. 4 is a perspective view of a support member used in the embodiment.

FIG. 5 is a side view of an engagement portion between the support member and the lock arm in the embodiment.

FIG. 6 is a longitudinal sectional view of a pressure control device according to a second embodiment of the present invention.

FIG. 7 is a side view of the embodiment.

FIG. 8 is a sectional view of a first example of a conventional pressure control device.

FIG. 9 is a sectional view of a second example of a conventional pressure control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 12 Side wall 13 Opening 20 1st rotating shaft 30 Valve body 40 Support member (member which rotates in conjunction with a valve body, winding member) 50 Valve body urging means 60 2nd rotating shaft 70 Lock arm 80 Ratchet mechanism 90 Lock arm biasing means

Claims (2)

(57) [Claims] 1. A pressure control device for opening an opening provided in a container when a pressure difference between the inside and outside of a container exceeds a predetermined value, and closing the opening when the pressure difference inside and outside the container returns to a predetermined value.
A valve element rotatably supported by a first rotating shaft from a position at which the opening is closed to a fully open position, and the valve element near the closed position via a ratchet mechanism that only allows the valve element to be rotated to the closed position In the limited range at the time, the valve body or a member that rotates in conjunction with the valve body is engaged and pushed when the valve body rotates from the closed position toward the fully open position, and is pushed out of the limited range. A lock arm rotatably supported by a second rotating shaft so as to rotate away from the valve; and a valve element closed by the lock arm when the lock arm is engaged with the valve element or the valve element interlocking member. Lock arm urging means for generating a first moment pushing in the direction, a stopper provided to prevent the lock arm from rotating beyond the limited range by the urging force, and closing the valve body at any position. The second to return to position A valve element urging means for generating a moment when the sum of the first moment and the second moment when the valve element is in the vicinity of the closed position exceeds a predetermined value. A pressure control device wherein a pressure difference is set to be equal to a moment of a force applied to a valve body. 2. A winding member supported by a horizontal shaft which rotates in a vertical plane in conjunction with the valve body, and one end of which is hung on a peripheral surface of the winding member. The other end is formed of a wire rod hanging down from the peripheral surface, and a weight attached to the hanging end of the wire rod. The peripheral surface of the winding member is biased by the weight. The non-circular shape so that a moment changes in accordance with a change in the position of the valve body and the second moment is maintained at a minimum value necessary for returning the valve body to the closed position. 2. The pressure control device according to 1.