JPH05187575A - Pilot valve - Google Patents

Abstract

PURPOSE:To restrain water hammer by providing a de-energizing flow path with a de-energizing means which changes the cross sectional form of the flow path, in the case of a valve furnished with the de-energizing flow path between a diaphragm which opens/closes a valve seat, and a diaphragm plate which is fixed on the back pressure side, and is furnished with a bleeding port. CONSTITUTION:A pilot valve which opens/closes fluid flow, is equipped with a diaphragm 12 which partitions the inside of a valve chamber into a fluid supply section at its lower side and a back pressure section at its upper side, and also opens/closes a valve seat installed in a fluid exhaust section and which is also furnished with a bleeding-in port 24 penetrating through its both sides. A diaphragm plate 32 in which a bleeding-out port 40 penetrating through both sides of the plate at a place different from that of the aforesaid bleeding-in port 24 is formed, is fixed on the back pressure section 58 side of the diaphragm 12, and the bleeding-in port 24 is communicated with the bleeding-out port 40 by way of a de-energizing flow path 26 which is partitioned between both of them 12 and 32. In this case, the de-energizing flow path 26 is provided with throttle sections 28... which are projected out of both side walls of the flow path into the de-energizing flow path 26 as a de-energizing means, in order to abruptly change the flow path cross sectional area within the de-energizing flow path 26, so that de-energizing effect can be thereby enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot valve, and more particularly to a pilot valve capable of reducing water hammer.

[0002]

2. Description of the Related Art Conventionally, in a pilot valve that selectively controls the flow of liquid by opening and closing the valve, a water hammer pressure is generated in the back pressure portion when the valve is closed, and the water hammer pressure causes vibration of the liquid supply pipe, etc. , A phenomenon called water hammer occurs. This water hammer has a problem in that it not only causes a failure of pipes, measuring instruments, control devices, etc., but also causes noise in an apartment house. Therefore, conventionally, a method for suppressing this water hammer has been developed. One example is the technique disclosed in JP-A-60-132186. In this structure, the extraction hole of the diaphragm plate and the extraction hole of the diaphragm are provided at different positions, and a depressurizing flow path that connects the extraction hole and the extraction hole is provided on the flat surface portion between the diaphragm and the diaphragm plate. .. As a result, the flow resistance of the liquid can be increased at the bent portion formed at the portion where the extraction hole and the depressurization flow path and the depressurization flow path and the extraction hole are connected. The length of the passage is increased so that the flow resistance of the passing liquid can be further increased.

[0003]

However, the above water hammer control system has the following problems.
If the deenergizing flow path is formed in an arc shape or a bent part is provided in the middle of the flow path to lengthen the flow path length, the flow resistance can be further increased and the water hammer can be sufficiently suppressed. In order to increase the length, the flat portion between the diaphragm and the diaphragm plate must be widened. That is, there is a problem that the valve becomes large. Therefore, an object of the present invention is to provide a pilot valve which is compact and has a sufficient water hammer suppression effect.

[0004]

In order to solve the above problems, the present invention has the following constitution. That is, it has a drawing hole penetrating through the front and back, defines a valve chamber into a liquid supply part and a back pressure part, and opens and closes a valve seat provided in the drain part, and a back pressure part of the diaphragm. The diaphragm plate fixed to the side and provided with an extraction hole penetrating the front and back at a position different from the extraction hole, and provided on a flat portion between the diaphragm and the diaphragm plate, and the extraction hole and the extraction hole. In the pilot valve having a depressurizing flow path communicating with each other, the depressurizing flow path is provided with a depressurizing means for changing a cross-sectional shape of the depressurizing flow path.

[0005]

The operation will be described with reference to FIGS. 2, 3, and 4. The liquid that has entered from the drawing hole 24 of the flow path plate 18 sandwiched between the diaphragm 12 and the diaphragm plate 32 is deenergized by the throttling portion 28 ... Since the cross-sectional shape of the abruptly changes, a vortex is generated, the energy of the liquid is consumed, the abrupt increase of the pressure in the back pressurizer 58 is suppressed, and the seating of the diaphragm 12 on the valve seat 54 is delayed. It is possible to prevent water hammer.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. [First Embodiment] A first embodiment will be described with reference to FIGS. 1 is a plan view of a diaphragm plate, FIG. 2 is a plan view of a flow channel plate, FIG. 3 is a cross-sectional view showing a state in which the diaphragm, the flow channel plate and the diaphragm plate are assembled into a valve body, and FIG. 4 is It is sectional drawing of the pilot valve using the valve body shown in FIG.

First, the structure will be described. Reference numeral 12 is a diaphragm, which is made of a flexible material such as rubber.
A center hole 14 is brought into contact with the center, and a diaphragm plate described later can be fitted therein. Further, a through hole 16 is also provided at the edge of the diaphragm 12 so that a drawing-in portion of a flow path plate described later can be fitted therein. Reference numeral 18 denotes a flow path plate, and a drawing-out portion 20 is provided on the bottom surface so as to project. The drawing-out portion 20 is fitted into the through hole 16 of the diaphragm 12 and is prevented from coming off by a flange portion 22. A drawing hole 24 is formed in the drawing section 20. Further, a depressurizing flow path 26 is engraved on the flat surface portion of the upper surface of the flow path plate 18, and the restricting portion 28 which is a depressing means protruding from both side walls of the depressurizing flow path 26 into the depressurizing flow path 26. Are provided so that the cross-sectional area of the flow passage in the de-energizing flow passage 26 changes abruptly. The upper end of the drawing hole 24 opens into the energy-reducing flow path 26. In addition, a fitting projection 30 for positioning is provided on the upper surface of the flow path plate 18 to serve as a positioning index when the assembly is attached to a diaphragm plate described later.

Reference numeral 32 denotes a diaphragm plate, which holds the flow path plate 18 together with the diaphragm 12. The lower portion of the central portion 34 of the diaphragm plate 32 is fitted into the central hole 14 of the diaphragm 12 and is prevented from coming off by the flange portion 36. A through hole 38 is formed in the center of the central portion 34 to allow the liquid to pass therethrough. Further, an extraction hole 40 is provided at the edge of the diaphragm plate 32. This extraction hole 40
Is transparently provided at a position corresponding to the deenergizing flow path 26 of the sandwiched flow path plate 18, and the extraction hole 40 and the extraction hole 24 are provided in the depressurizing flow path 2
6 is contacted. The diaphragm plate 32 is provided with a through hole 42 that can be fitted to the fitting projection 30 that is provided on the upper surface of the flow path plate 18, and the diaphragm plate with respect to the flow path plate 18 can be fitted by fitting them. Accurate positioning of 32 is possible. The diaphragm 12, the flow path plate 18,
And the diaphragm plate 32, as shown in FIG.
As a result of being assembled as No. 4, the depressurizing flow path 26 is formed in the pipe line between the diaphragm 12 and the diaphragm plate 32. The pilot valve 10 in which the assembled valve element 44 is arranged in the valve chamber 60 will be described.

The state shown in FIG. 4 is a state in which the electromagnetic coil 46 is not energized, and the plunger 48 presses the center of the diaphragm plate 32 with the lower end surface by the urging force of the coil spring 50 and closes the through hole 38. ing. Furthermore, since the lower surface of the diaphragm 12 closes the valve seat 54 of the drainage portion 52 by the pressing force of the coil spring 50,
The liquid is not discharged, and the liquid supplied into the liquid supply unit 56 passes through the extraction hole 24, the depressurizing flow path 26 and the extraction hole 40, and the back pressure unit 5
8 and the back pressure is applied to the valve element 44. Here, when the electromagnetic coil 46 is energized, a magnetic circuit is formed around the electromagnetic coil 46 and the leakage magnetic flux is generated by the plunger 48.
Is attracted upward against the biasing force of the coil spring 50. Then, the lower end surface of the plunger 48 opens the through hole 38. Due to this opening, the liquid in the back pressure portion 58 allows the through hole 38 to pass through.
And is discharged to the drainage section 52. Further, since the pressing force of the diaphragm plate 32 is also released, the valve body 44 is moved upward by the elastic force of the diaphragm 12, and the valve seat 54 is opened. Then, the liquid that has reached the liquid supply unit 56 is discharged from the opened valve seat 54 to the liquid discharge unit 52. This allows the liquid to flow.

When the energization of the electromagnetic coil 46 is stopped again to stop the flow of the liquid, the magnetic force disappears,
The plunger 48 moves downward again by the urging force of the coil spring 50, presses the diaphragm plate 32, and closes the through hole 38. For this reason, the pressure in the back pressure portion 58 starts to increase due to the pressure of the liquid flowing in from the extraction port 24, and the valve body 4
4 descends. On the other hand, although the liquid flowing in from the drawing port 24 enters into the depressurizing flow path 26, since the depressurizing flow path 26 is provided with the narrowed portion 28 ... Along with this, the liquid forms a vortex immediately after the throttle portion 28 ... And the energy of the liquid flow is consumed. Since this is repeated a plurality of times, the flow velocity drops, and the energy of the liquid is largely consumed until the liquid enters the back pressure portion 58 through the extraction hole 40, so that the pressure in the back pressure portion 58 does not rise sharply. Therefore, the seating of the diaphragm 12 on the valve seat 54 is delayed and becomes loose, and the water hammer can be suppressed. At that time, due to the liquid supply pressure of the liquid supply unit 56,
The length of the energy-reducing flow path 26 and the number of narrowed portions 28 ... May be set appropriately.

[Second Embodiment] A second embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 is a bottom view of the diaphragm plate, and FIG. 6 is a cross-sectional view of a valve body formed by attaching the diaphragm plate to the diaphragm. In this embodiment, the doubled weakening flow paths 100a, 1
00b is engraved on the flat surface portion on the bottom surface side of the diaphragm plate 102, and both the depressurizing flow paths 100a and 100b are connected to each other. There are a plurality of extraction ports 104 ...
6, and each of the extraction ports 104 ... Is opened at a position corresponding to the depressurizing flow path 100a. Exit 10
The reason for providing a plurality of 4 ... is to ensure stable operation even when foreign matter is clogged due to foreign matter being clogged up at some of the slot 104 ... This is because Further, the energy-reducing flow passage 100b has a large-diameter portion 108 ...
08 is formed by a projecting portion 110 that protrudes inward. Note that the extraction port 112 is the deenergizing flow path 1
The opening is made in the large diameter portion 108 provided at the end of 00b.

When the valve body 114 composed of the diaphragm 106 and the diaphragm plate 102 is used as the valve body of the pilot valve 10 of the first embodiment, the basic operation is exactly the same, but the valve body 114 has a valve seat. When 54 is closed, the liquid in the liquid supply part 56 enters the valve body 114 from the drawing port 104 ... And enters the de-energizing flow path 100a formed between the diaphragm 106 and the diaphragm plate 102. Then, it enters into the de-energizing flow path 100b. And the de-energizing channel 100
In b, the flow path cross-sectional area is rapidly changed by the large-diameter portions 108, and the flow is disturbed by the protrusions 110, so that vortices are generated. The generation of this vortex consumes the energy of the liquid flow. Therefore, it is possible to suppress the water hammer as in the first embodiment.

[Third Embodiment] A third embodiment will be described with reference to FIGS. 7 and 8. FIG. 7 is a plan view of the diaphragm,
FIG. 8 is a sectional view of a valve body using the diaphragm. In this embodiment, the double deenergizing flow paths 200a, 2
00b is engraved on the flat surface of the upper surface of the diaphragm 202 side. The deenergizing flow paths 200a and 200b are in communication with each other. A plurality of drawing ports 204 ... Are provided in the de-energizing flow path 200a, and a measure against clogging is taken as in the second embodiment. Further, a plurality of throttle portions 206 ... Protruding from the side wall are provided in the de-energizing flow path 200a so as to form a de-energizing means. The diaphragm plate 208 is provided with an extraction hole 210 at a position corresponding to the depressurizing flow path 200b of the diaphragm 202. Similar to the second embodiment, this valve body 212 is
When used as the valve body of the pilot valve 10 of the first embodiment,
The basic operation is exactly the same, but when the valve body 212 closes the valve seat 54, the liquid in the liquid supply part 56 enters the valve body 212 from the drawing port 204 ... And the diaphragm 202. And the diaphragm plate 208 enter the energy-reducing flow path 200a, and vortices are generated in the throttle portion 206 ... As in the first embodiment, and the energy of the liquid flow is consumed. Then, since it exits from the extraction port 210 through the energy-reducing flow path 200b, it is possible to suppress the water hammer as in the first and second embodiments.

In the above-mentioned embodiment, the flow passage area is suddenly expanded or contracted or the projection in the flow passage is used as the energy reducing means having the changed sectional shape. The vortex may be generated by installing a discharge portion, forming a concavo-convex portion in the flow path, and arranging an obstacle such as a turbulent flow forming plate. At that time, the length of the deenergizing passage, the selection of the deenergizing means, the number of disposing elements, etc. may be arbitrarily set in consideration of the usage conditions of the pilot valve. Although various preferred embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above embodiments and many modifications can be made without departing from the spirit of the invention. ..

[0015]

When the pilot valve according to the present invention is used,
Since it is possible to suppress a sudden increase in the liquid pressure in the back pressure portion when the valve is closed, it is possible to delay the seating of the valve body such as the diaphragm on the valve seat, and it is possible to suppress the water hammer. Moreover, since the elastic design such as the length of the deenergizing flow path and the number of the deenergizing means is possible, it is possible to suppress the water hammer most efficiently. In addition, since the kinetic energy of the liquid flow can be efficiently consumed by providing the energy reducing means for changing the cross-sectional shape of the energy reducing flow path in the middle of the energy reducing flow path, even if the energy reducing flow path is short, the flow velocity is low. Can be sufficiently dropped, and it is not necessary to enlarge the diaphragm or diaphragm plate, and the pilot valve can be made compact.

[Brief description of drawings]

FIG. 1 is a plan view of a diaphragm plate according to a first embodiment of the pilot valve of the present invention.

FIG. 2 is a plan view of the flow channel plate.

FIG. 3 is a sectional view of the valve body.

FIG. 4 is a sectional view of a pilot valve incorporating the valve body of FIG.

FIG. 5 is a bottom view of the diaphragm plate according to the second embodiment of the pilot valve of the present invention.

FIG. 6 is a sectional view of a valve body using the diaphragm plate.

FIG. 7 is a plan view of a diaphragm according to a third embodiment of the pilot valve of the present invention.

FIG. 8 is a sectional view of a valve body using the diaphragm.

[Explanation of symbols]

 10 Pilot valve 12 Diaphragm 18 Flow path plate 24 Extraction hole 26 Depressurization flow path 28 Throttling part 32 Diaphragm plate 40 Extraction hole 52 Drainage part 54 Valve seat 56 Liquid supply part 58 Back pressure part 60 Valve chamber

Claims (2)

[Claims] 1. A diaphragm which has a drawing hole penetrating through the front and back, defines a valve chamber in a liquid supply section and a back pressure section, and opens and closes a valve seat provided in a drain section, and a diaphragm of the diaphragm. A diaphragm plate fixed to the back pressure part side, provided with an extraction hole penetrating the front and back at a position different from the drawing hole, and provided in a flat surface portion between the diaphragm and the diaphragm plate, and the drawing hole. A pilot valve comprising a depressurizing flow path communicating with the extraction hole, wherein the depressurizing flow path is provided with a depressurizing means for changing a cross-sectional shape of the depressurizing flow path. 2. The pilot according to claim 1, wherein a flow path plate having the depressurizing means and having the depressurizing flow path is sandwiched between the diaphragm and the diaphragm plate. valve.