JP4349715B2 - Switching valve - Google Patents

Description

[0001]
【Technical field】
The present invention relates to a switching on-off valve that can switch between a small flow rate and a large flow rate using the same flow path, and a switching on-off valve that can smoothly transition from a small flow rate state to a large flow rate state.
[0002]
[Prior art and its problems]
Conventionally, in a system that requires switching between a small flow rate (for example, several mL / min) and a large flow rate (same number L / min), a small flow valve and a large flow valve are provided in parallel, and one of them is selected and opened. It was normal. However, this conventional apparatus requires two valves, a small flow valve and a large flow valve, a parallel pipe, and a branch connector (cheese) provided at the branch of the parallel pipe. Cost and space are expensive.
[0003]
OBJECT OF THE INVENTION
The present invention provides a switching on-off valve that can flow by changing the flow rate from a small flow rate to a large flow rate, and further from a small flow rate to a large flow rate, with a single valve, based on the above awareness of the problems with conventional devices. Objective.
[0004]
Summary of the Invention
The switching on-off valve of the present invention includes a valve stem that opens and closes a flow path; a relative moving piston body that is slidably fitted to the valve stem; an integral moving piston body that is fixed to the valve stem; and an integral movement with the valve stem. An urging means for moving and urging the piston body in the flow path closing direction; when the relative movement piston body moves in the valve opening direction opposite to the movement direction of the valve stem by the urging means, together with the relative movement piston body A stopper provided in the valve stem for moving the valve stem in the valve opening direction; a relative movement pressure chamber for applying pressure in the valve opening direction to the relative movement piston body; for applying pressure in the valve opening direction to the integral movement piston body integrally moving the pressure chamber; first opening means exert a pilot pressure to the relative movement the pressure chamber; and a second valve opening means for exerting a pilot pressure to integrally move the pressure chamber; has, integrally moving pressure and the relative movement the pressure chamber The pilot pressure is applied to the relative movement pressure chamber via the first valve opening means, and then integrated with the chamber via the communication passage having the throttle valve. It is characterized by being given to the moving pressure chamber . Thereby, it can switch smoothly from a small flow volume to a large flow volume using the same flow path.
[0006]
Further, this switching on-off valve is provided with a direct communication path that allows the relative movement pressure chamber and the integral movement pressure chamber to communicate with each other without a throttle valve when the valve stem moves a certain distance in the valve opening direction from the flow path closing position. The flow rate can be changed in multiple stages.
[0007]
Further, when an adjustment member that adjusts the relative maximum movement distance of the relative movement piston body with respect to the valve stem is provided, the flow rate in the small flow rate state can be adjusted. Further, it is practical that the adjusting member is a ring-shaped member that accommodates the relative moving piston body and the integrally moving piston body and is screwed into the cylinder.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show an embodiment of a switching on-off valve according to the present invention. The fluid passage 12 is provided in the flow path block 11 located below the FIG. 1, FIG. 2 and FIG. 3, and an annular valve seat 13 having a vertical axis in the figure is formed in a part thereof. A rod holder 14 that slidably guides a valve stem 20 coaxial with the annular valve seat 13 is fixed to the flow path block 11 via a connector sleeve 15. The lower end of the rod holder 14 and the flow path block are fixed. 11, the peripheral edge of a disk-shaped metal diaphragm 16 that opens and closes the annular valve seat 13 is sandwiched.
[0009]
A cylinder 22 is fixed to the upper end of the rod holder 14 in the figure. The cylinder 22 is closed at the lower end by the rod holder 14 and is opened at the upper end. A stroke adjusting sleeve (ring-shaped member) 19 is screwed into the open portion at the upper end of the cylinder 22 coaxially with the valve stem 20. A cap 18 is fixed to the open portion of the upper end of the stroke adjusting sleeve 19 in the figure.
[0010]
An integral moving piston body 24 is fixed to the valve stem 20 that extends further upward from the rod holder 14 through the cylinder 22. The integral moving piston body 24 includes stopper rings 25a and 25b, a retainer 26, a rolling diaphragm 27, and a center body 28. The stopper rings 25 a and 25 b sandwich the center body 28 with the valve stem 20. A retainer 26 is coaxially fixed to the center body 28. An inner edge of a disk-shaped rolling diaphragm 27 is sandwiched between the retainer 26 and the center body 28. The peripheral edge of the rolling diaphragm 27 is sandwiched between the lower end portion of the cap 18 and the stroke adjusting sleeve 19. The rolling diaphragm 27 is known as a diaphragm whose pressure receiving area does not change even when the integral moving piston body 24 is operated, and can ensure a large stroke in the integral moving piston body 24 (valve stem 20).
[0011]
Between the cap 18 and the retainer 26 (integrated moving piston body 24), the valve stem 20 is urged to move downward in the figure, and the metal diaphragm 16 is moved to the annular valve seat 13 via the valve stem 20 and the piece 21. A compression spring 17 is inserted to press it. Therefore, the valve stem 20 is always biased in the direction of closing the annular valve seat 13 via the metal diaphragm 16.
[0012]
The amount of movement of the integral moving piston body 24 (valve stem 20) is determined by a distance D2 at which the upper end portion of the retainer 26 (integral moving piston body 24) contacts the end face inside the cap 18. On the other hand, the movement of the piece 21 provided between the valve stem 20 and the metal diaphragm 16 is determined by the distance D1 at which the flange 21a of the piece 21 contacts the end face inside the rod holder 14. Since this interval is D2> D1, contact of the retainer 26 and the cap 18 (upper restriction of the integral moving piston body) does not prevent the valve from being fully opened.
[0013]
A relative movement piston body 23 is fitted below the integral movement piston body 24 of the valve stem 20 so as to be relatively slidable. When the relative movement piston body 23 moves in the valve opening direction (upward in the drawing) opposite to the movement direction of the valve stem 20 by the compression spring 17, the abutment movement piston body 24 (stopper ring 25b) comes into contact with the stopper ring 25b. Are moved together to move the valve stem 20 in the valve opening direction. On the other hand, the relative movement piston body 23 can move downward in the figure with respect to the valve stem 20.
[0014]
The stroke adjustment sleeve 19 is an adjustment member that can adjust the screwing position with respect to the cylinder 22, and the upward movement amount of the relative movement piston body 23 is limited by the distance d between the stroke adjustment sleeve 19 and the relative movement piston body 23 ( Controlled). Reference numeral 36 denotes a fixing screw for fixing the stroke adjusting sleeve 19 to the cylinder 22 after adjusting the screwing position.
[0015]
A relative movement pressure chamber 34 is formed between the cylinder 22, the relative movement piston body 23 and the valve stem 20, and between the integral movement piston body 24, the stroke adjustment sleeve 19 and the relative movement piston body 23. The integral moving pressure chamber 35 is formed. The relative movement pressure chamber 34 communicates with a pilot pressure passage 31 and a connection port 30 formed in the cylinder 22, and the pilot pressure connection port 30 is connected to a pilot pressure source 41 via a control valve 40. Further, the relative movement pressure chamber 34 communicates with the integral movement pressure chamber 35 from the communication passage 32 a formed in the cylinder 22 through the throttle valve 33 and the communication passage 32 b formed in the valve stem 20.
[0016]
The apparatus having the above-described configuration operates as follows. When the pilot pressure is not introduced, the valve stem 20 urged in the valve closing direction by the force of the compression spring 17 presses the metal diaphragm 16 against the annular valve seat 13 to close the fluid passage 12 (FIG. 1). ). When a pilot pressure is applied to the pilot pressure connection port 30 via the control valve 40 in this valve closed state, the pilot pressure is introduced into the relative movement pressure chamber 34 via the pilot pressure passage 31, and the relative movement piston body 23 An upward force in the figure is exerted. Therefore, the relative movement piston body 23 raises the valve stem 20 via the stopper ring 25b. The rising end is regulated at a position where the relative movement piston body 23 contacts the stroke adjusting sleeve 19 (FIG. 2). Although the distance d between the relative movement piston body 23 and the stroke adjusting sleeve 19 is exaggerated in the drawing, it is actually very small (can be), and therefore the metal diaphragm 16 and the annular valve at this time A small flow rate of about several mL / min can be obtained by the gap formed between the seat 13 (initial operation stage shown in FIG. 5).
[0017]
When the pilot pressure continues to be applied, the pilot pressure is introduced into the integral moving pressure chamber 35 via the communication passages 31, 32a, 32b (the flow path a shown in FIG. 2), and the integral moving piston body 24 is moved upward in the figure. The valve is fully opened (step a shown in FIG. 5). Accordingly, the integral moving piston body 24 gradually raises the valve stem 20 via the center body 28 and the stopper ring 25a, and the gap formed between the metal diaphragm 16 and the annular valve seat 13 at this time is gradually increased. The flow rate gradually increases.
[0018]
When the valve stem 20 rises while continuing to apply the pilot pressure, the O-ring 29 that keeps the secret between the valve stem 20 and the cylinder 22 is released from the cylinder 22 (FIG. 3). Then, as shown in FIG. 4, since there is a sliding clearance 32c (direct communication path) between the valve stem 20 and the cylinder 22, the pilot pressure does not pass through the throttle valve 33 but through the communication paths 32b and 32c. The integrated moving pressure chamber 35 is introduced (the flow path b shown in FIG. 3 and the section b shown in FIG. 4), and the valve stem 20 is quickly raised. That is, the increase rate of the flow rate is increased, and the maximum flow rate of about several L / min can be finally reached.
[0019]
According to the present embodiment, as shown in FIG. 5, the flow rate is gradually increased from the valve closed state through the initial minute flow rate in the initial operation stage, and the maximum (full open) flow rate change operation is switched by a constant pilot pressure. Can be obtained without doing. Furthermore, when the valve stem 20 moves and the fixed O-ring 29 is detached from the cylinder 22, the flow rate change rate can be increased during the opening of the valve.
[0020]
In the above embodiment, the first valve opening means and the second valve opening means are a series of communication passages that continue from the relative movement pressure chamber to the integral movement pressure chamber via the throttle valve, but may be provided independently. Good. In the present embodiment, the valve stem 20 is a type of on-off valve that presses the metal diaphragm 16 that opens and closes the annular valve seat 13. The present invention can also be applied to a structure or a valve structure that transmits the movement of the valve stem 20 to a valve body separate from the valve stem 20. Further, if various boosting structures are interposed between the valve stem 20 and the metal diaphragm 16, the present invention can also be applied to an on-off valve of a high-pressure line.
[0021]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain a switching on-off valve that can smoothly shift from a small flow rate state to a large flow rate state using a single valve and the same flow path.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a valve closed state of an embodiment of a switching on-off valve according to the present invention.
2 is a cross-sectional view showing an initial operation stage of the embodiment shown in FIG. 1;
FIG. 3 is a cross-sectional view showing a valve fully opening operation stage of the embodiment shown in FIG. 1;
4 is a cross-sectional view taken along line IV-IV in FIG.
FIG. 5 is a diagram showing a change in flow rate due to the operation of the switching on-off valve shown in FIGS. 1 to 4;
[Explanation of symbols]
11 Flow path block 12 Fluid path 13 Annular valve seat 14 Rod holder 15 Connector sleeve 16 Metal diaphragm 17 Compression spring 18 Cap 19 Stroke adjustment sleeve (ring-shaped member)
20 Valve stem 21 Frame 21a Flange 22 Cylinder 23 Relative moving piston body 24 Integrated moving piston body 25a 25b Stopper ring 26 Retainer 27 Rolling diaphragm 28 Central body 29 O-ring 30 Pilot pressure connection port 31 Pilot pressure passage 32a 32b 32c Communication passage 33 Restriction Valve 34 Relative moving pressure chamber 35 Integrated moving pressure chamber 36 Fixing screw 40 Control valve 41 Pilot pressure source

Claims (4)

A valve stem that opens and closes the flow path;
A relative moving piston body fitted to the valve stem to be slidable relative to the valve stem;
An integral moving piston body fixed to the valve stem;
Urging means for urging and moving the valve stem and the integrally moving piston body in the flow path closing direction;
A stopper provided on the valve stem that moves the valve stem in the valve opening direction together with the relative movement piston body when the relative movement piston body moves in the valve opening direction opposite to the movement direction of the valve stem by the biasing means. ;
A relative moving pressure chamber for applying pressure in the valve opening direction to the relative moving piston body;
An integral moving pressure chamber for applying pressure in the valve opening direction to the integral moving piston body;
Second opening means for exerting and pilot pressure to move together the pressure chamber; first opening means exert a pilot pressure to the relative movement the pressure chamber has,
The relative movement pressure chamber and the integral movement pressure chamber communicate with each other through a communication passage having a throttle valve, and the pilot pressure is applied to the relative movement pressure chamber via the first valve opening means, and then the throttle Provided to the integral moving pressure chamber via a communication passage having a valve;
A switching on-off valve characterized by that. The switching on-off valve according to claim 1 ,
Further, a switching on-off valve provided with a direct communication path that allows the relative movement pressure chamber and the integral movement pressure chamber to communicate with each other without a throttle valve when the valve stem moves a certain distance in the valve opening direction from the flow path closing position. . In the switching on-off valve according to claim 1 or 2 ,
A switching on-off valve provided with an adjusting member for adjusting a relative maximum moving distance of the relative moving piston body relative to a valve stem. In the switching on-off valve according to claim 3 ,
The adjusting member is a switching on-off valve that is a ring-shaped member screwed into a cylinder that houses the relative moving piston body and the integral moving piston body.

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