JPH0444945Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to an automatic pressure regulating valve.

[Prior Art] In a conventional automatic pressure regulating valve used in a water supply device, etc., a valve hole 3 is provided between a primary flow path 1 and a secondary flow path 2, as illustrated in FIG. and,
A valve body 4 that can control the opening degree of the valve hole 3, a control pressure chamber 6 that communicates with the primary flow path 1 through the control valve 5, and a control pressure chamber that communicates with the secondary flow path 2 through the control valve 5, for example. 6, a piston part 8 fitted in the cylinder part 7 in conjunction with the valve body 4, and the control pressure chamber 6 and the secondary flow path 2 are connected to each other. A communicating path 9 is provided.

This communication passage 9 is connected to the control pressure chamber 6 together with the control valve 5.
They are provided to adjust the internal pressure to obtain desired operating characteristics, and are generally desired to have relatively high flow resistance. Conventionally, this communication passage 9 is provided on the valve body 10 side as shown in the figure, or on the piston part 8 side, but in either case, it has to be formed into a relatively short straight line mainly due to processing constraints. Therefore, in order to obtain the desired flow resistance, the diameter had to be made small. Therefore, when there are many foreign substances such as rust and sand in the flow, clogging accidents are likely to occur, and there are problems such as pressure control becoming impossible.

In order to prevent such problems, for example, a thin wire such as an S-shaped wire is inserted into the communication path 9, and the wire is displaced and deformed by the flow of fluid to prevent blockage caused by foreign objects. Although attempts have been made, sufficient results have not been achieved, with some cases having the opposite effect.

On the other hand, since there is a slight gap in the sliding contact part 11 between the cylinder part 7 and the piston part 8, a piston ring 12 such as an O-ring is provided to improve sealing performance. As mentioned above, when there are many foreign substances in the fluid, the piston part 8
When the piston ring 12 is displaced, the piston ring 12 does not slide uniformly around the entire circumference and is twisted and damaged, or it is worn out and the sealing performance is impaired, and the mutual sliding contact portion 1
1, there was a problem in that foreign matter could become trapped and cause malfunctions.

Furthermore, if a strainer or the like is attached to remove foreign matter, not only will costs increase due to larger size and an increase in the number of parts, etc., but also maintenance to prevent clogging will require more effort.

[Problems to be solved by the invention] The present invention was developed under the above circumstances, and it is an automatic pressure regulating valve that does not require a strainer or the like even for fluids containing many foreign substances, and is highly reliable. The purpose is to provide

[Means for solving the problems] The present invention provides a cylinder section interposed between a flow path on either the primary side or the secondary side and a control pressure chamber, and a piston fitted in the cylinder section. It is characterized by a spiral groove formed in at least one of these parts, located at the mutual sliding contact part of the parts.

[Operation] Since the present invention is provided with a communicating path from the spiral groove as described above, the path length can be set to be sufficiently long. Therefore, the cross-sectional area can be set sufficiently large to obtain the desired flow resistance, and since the foreign matter can flow freely, malfunctions such as blockages will not occur. Furthermore, since piston rings and the like are not required, problems due to twisting, damage, wear, etc., do not occur.

[Embodiment of the invention] Hereinafter, the present invention will be described with reference to an illustrated embodiment. In FIGS. 1 and 2, the main body 20 includes a valve box 21 and a valve cover 22, between which a peripheral portion of a diaphragm 23 is held in a fluid chamber. Primary side flow path 24 formed in the valve box 21
A valve hole 26 is provided between the flow path 25 and the secondary flow path 25 . A piston part 28 is slidably fitted into the cylinder part 27 supported by the valve box 21, and the valve box 21, the cylinder part 27, and the piston part 28 are connected to each other.
A control pressure chamber 29 is formed by the diaphragm 23 and the diaphragm 23.
is formed. A valve body 30, which is provided to be able to control the opening degree of the valve hole 26, is movably connected to the piston portion 28 via a valve shaft 31, and
It is biased in the closing direction by a spring member 32 housed in the valve lid 22. The primary flow path 24 is communicated with the control press-in chamber 29 via a control valve 33 that is opened when the internal pressure thereof rises above a set value. Further, the other secondary flow path 25 is communicated with a control pressure chamber 29 via a communication path 34.

The communication passage 34 is located at a mutual sliding contact portion 35 of the cylinder portion 27 and the piston portion 28, and is provided in at least one of these portions, for example, the piston portion 28, and forms a spiral groove. The cross-sectional shape of this groove is formed to such an extent that foreign matter contained in the flowing fluid can flow freely. Additionally, the length of the groove is set to provide a flow resistance to the fluid that corresponds to the desired operating characteristics.

According to the above configuration, normal control operations are performed in the same manner as in the conventional example. however,
Since the communication path 34 can allow foreign matter to flow freely while maintaining a desired flow resistance, there is no possibility of blockage accidents caused by foreign matter. In addition, since the piston ring 12 as in the above conventional example is not required,
There are no problems caused by its presence. Therefore, high reliability can be obtained even when used with fluids containing a large amount of foreign matter, and since a strainer is not required, there is no need for an increase in size or number of parts, and maintenance is simple and easy. It's easy.

[Effects of the Invention] According to the present invention, as described above, it is possible to provide an automatic pressure regulating valve that has a simple structure, is excellent in reliability, and is particularly suitable for fluids containing many foreign substances.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a side view showing an enlarged main part of the same example, and FIG. 3 is a sectional view showing a conventional example. 24...Primary side flow path, 25...Secondary side flow path, 2
6... Valve hole, 27... Cylinder part, 28... Piston part, 29... Control pressure chamber, 30... Valve body, 3
4...Communication path, 35...Mutual sliding contact portion.

Claims (1)

[Scope of utility model registration request] Controls the opening degree of the cylinder section interposed between either the primary or secondary flow path and the control pressure chamber, and the valve hole interposed between the primary and secondary flow paths. automatic pressure adjustment having a piston part fitted in the cylinder part in conjunction with a possible valve body; and a communication passage communicating the control pressure chamber with a flow passage on either the primary side or the secondary side. An automatic pressure regulating valve characterized in that the communication passage is located at a mutual sliding contact portion of the cylinder portion and the piston portion and consists of a spiral groove formed in at least one of these portions.