JPH03598Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is a line that is installed in a straight line in the fluid circuit of devices and equipment, and allows fluid to pass in only one direction and prevents flow in the opposite direction. Regarding backflow prevention equipment,
In particular, the present invention relates to an adjustment line backflow prevention device that can vary the cracking pressure.

(Prior Art) Conventionally, line backflow prevention devices have been widely used because their flow paths are straight, so they can be easily installed in the middle of pipes.

On the other hand, as this type of line backflow prevention device, an adjustable line backflow prevention device that can vary the cracking pressure is known. That is, the adjustment line backflow prevention device has a stopper 1 on the upstream side, as shown in Fig. 4.
7; a cylindrical gland 20 fitted into the housing 18 and having a through hole 19;
A plug body 21 is fitted into the gland 20 so as to be freely slidable in the axial direction, and is seated against the plug seat 17. An adjustment screw 22 , a spring 23 that is interposed between the stopper 21 and the adjustment screw 22 and urges the stopper 21 to sit on the stopper seat 17 , and a spring 23 in the casing 18 on the downstream side of the adjustment screw 22 . It is comprised of a cylindrical lock screw 24, etc., which is screwed into and abuts the adjustment screw 22. In the figure, 25 is the 0 ring, 26 is the front ferrule, 27 is the back ferrule, and 2
8 is Natsuto.

In the adjustment line backflow prevention device, when the pressure on the upstream side is smaller than the biasing force of the spring 23, the stopper body 21 is seated against the stopper seat 17 to block the flow path. When the pressure increases and reaches a predetermined cracking pressure, the plug body 21 is pushed downstream and separated from the plug seat 17, and the upstream fluid flows into the through hole 19, the gland 20, and each screw 2.
2 and 24 in order and exit to the downstream side. In addition, the cracking pressure is adjusted using adjustment screw 2.
2 and the lock screw 24 in the axial direction.

However, in the adjustment line backflow prevention device, even if the cracking pressure is set to a predetermined value, if the device is subjected to some kind of vibration or time passes, the lock screw 24 will loosen and the adjustment will be difficult. There was a problem in that the screw 22 moved a certain amount and the biasing force of the spring 23 changed, causing the cracking pressure to fluctuate. In this case, other devices and equipment will be adversely affected.

(Problem to be solved by the invention) The present invention was devised to solve the above problem, and its purpose is to make an adjustment that can reliably prevent changes in the biasing force of the spring set to a predetermined value. To provide line backflow prevention equipment for use.

(Means for Solving the Problems) The adjustment line backflow prevention device of the present invention has a cylindrical casing with a stopper on the upstream side, and a cylindrical case that is movable in the axial direction inside the casing. A stopper body that is unseated,
A cylindrical adjustment screw screwed into the downstream side of the housing,
In the backflow prevention device, an adjustment line consisting of a spring interposed between the stopper and the adjustment screw and energizing the stopper to seat the stopper in the stopper seat, an adjustment line extending along the axis of the adjustment screw. It is characterized by the fact that it has grooves that allow it to freely contract and expand its diameter, and its outer diameter is set to be slightly larger than the inner diameter of the casing.

(Function) In the adjustment line backflow prevention device, when the pressure on the upstream side is smaller than the urging force of the spring, the plug body rests against the stopper seat and blocks the flow path, and the pressure on the upstream side becomes high. When a predetermined cracking pressure is reached, the plug body is pushed downstream against the urging force of the spring and separated from the stopper seat, and the fluid on the upstream side passes through the flow path in the housing to the downstream side. go.

In addition, the adjustment screw that supports one end of the spring has a split groove along the axial direction to allow the diameter to be expanded or contracted freely, and the outer diameter is set slightly larger than the inner diameter of the casing, so the adjustment screw is like this. When screwed into the housing, it has an elastic force that tends to expand outward. As a result, the adjustment screw is securely fixed within the housing and will not be affected if it loosens and moves. Furthermore, the biasing force of the spring does not change, and fluctuations in cracking pressure can be prevented.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a longitudinal sectional view of an adjustment line backflow prevention device according to an embodiment of the present invention in a fully closed state, in which 1 is a housing, 2 is a stopper, 3 is an adjustment screw, and 4 is a spring.

The housing 1 consists of a cylindrical male body 5 and a cylindrical female body 6 screwed onto one side of the body. A stopper seat 7 is formed. Other pipes (not shown) are connected to both ends of the housing 1, respectively.

The stopper body 2 is provided within the housing 1 so as to be freely movable in the axial direction so as to be seated on and removed from the stopper seat 7. That is, in this embodiment, the stopper 2 has a substantially cylindrical shape with the upstream side closed, and the O-ring 8 is fitted on the upstream side, and the O-ring 8 is in contact with the stopper seat 7. It is fitted into a cylindrical gland 9 fitted into the male main body 5 so as to be slidable in the axial direction.

A space S is formed between the outer circumferential wall of the gland 9 on the upstream side from the intermediate portion and the inner circumferential surface of the male main body 5, and the upstream outer circumferential wall and the intermediate outer circumferential wall of the gland 9 have a space S. A first through hole 10 and a second through hole 11 that communicate between the space S and the inside of the ground 9 are bored, respectively. Further, the plug body 2 is designed to reciprocate on the upstream side of the second through hole 11, and when it touches the stopper seat 7, it closes the first through hole 10 and is spaced a certain distance from the stopper seat 7. At times, the first through hole 10 is left open.

The adjustment screw 3 is screwed into the downstream side of the housing 1, that is, into the female body 6 so as to be movable in the axial direction. That is, as shown in FIGS. 2 and 3, the adjustment screw 3 is formed into a cylindrical shape having a hexagonal square hole 12 in the center. Further, the adjusting screw 3 has a split groove 13 formed along the axial direction so that the diameter can be freely contracted or expanded, and the outer diameter thereof is set to be slightly larger than the inner diameter of the female mold body 6. Furthermore, the adjustment screw 3 is plated with silver. Therefore, when the adjustment screw 3 is screwed into the female mold main body 6, it has an elastic force that tends to expand outward, and is well fixed within the female mold main body 6. Furthermore, since the adjustment screw 3 is silver-plated, galling can be prevented.

The spring 4 is interposed between the stopper 2 and the adjustment screw 3 and biases the stopper 2 to seat it on the stopper seat 7, and its biasing force moves the adjustment screw 3 in the axial direction. Adjusted by

In FIG. 1, 14 is a front ferrule, 15 is a back ferrule, and 16 is a nut.

Next, the operation of the adjustment line backflow prevention device will be explained.

When the pressure on the upstream side is smaller than the urging force of the spring 4, the stopper body 2 abuts against the stopper seat 7 and blocks the flow path.

When the pressure on the upstream side increases and reaches a predetermined cracking pressure, the plug body 2 is pushed downstream against the biasing force of the spring 4 and is removed from the plug seat 7.

When the plug body 2 is pushed to the position where it opens the first through hole 10 of the gland 9, the upstream fluid flows through the gap between the plug seat 7 and the plug body 2, the first through hole 10, the space S, and the second through hole. Hole 11, inside gland 9, square hole 1 of adjustment screw 3
2 in sequence and exit to the downstream side.

In addition, when changing the biasing force of the spring 4, remove the female mold body 6 side from the piping, insert a hexagonal wrench into the square hole 12 of the adjustment screw 3 from the downstream side of the female mold body 6, and use the wrench to tighten the adjustment screw 3. All you have to do is rotate it in forward and reverse directions and move it in the axial direction.

In the above embodiment, only the adjustment screw 3 was screwed into the female body 6, but in other embodiments,
A cylindrical lock screw (not shown) may be screwed into the female body 6 on the downstream side of the adjustment screw 3 to engage with the adjustment screw 3. In this case, movement of the adjustment screw 3 can be prevented even more reliably.

Further, in the above embodiment, the adjusting screw 3 is plated with silver, but the adjusting screw 3 may be plated with other types of plating.

Furthermore, in the above embodiment, the cylindrical gland 9 was fitted into the housing 1, and the cylindrical plug 2 with one end closed was fitted into the gland 9. This is not limited to the embodiment, and when the stopper body 2 touches the stopper seat 7, the flow path is blocked, and when the stopper body 2 leaves the stopper seat 7, the upstream side and the downstream side of the housing 1 communicate with each other. In this case, the shape of the plug 2 and the configuration in which the plug 2 is housed in the housing 1 are arbitrary.

In addition, the configuration and shape of the housing 1 are not limited to the above embodiments.

(Effects of the invention) As mentioned above, the adjustment line backflow prevention device of the invention forms a split groove along the axial direction in the adjustment screw that supports one end of the spring, so that the diameter can be freely contracted and expanded, and Since the diameter is set to be slightly larger than the inner diameter of the casing, the adjustment screw has an elastic force that tends to expand outward when it is screwed into the casing. As a result, the adjustment screw is securely fixed within the housing and will not move from the set position even if the device is subjected to some vibration or over time. Furthermore, the cracking pressure does not change due to changes in the biasing force of the spring during use of the device, and other devices and devices installed in the fluid circuit are not adversely affected.

In addition, the adjustment line backflow prevention device of the present invention has elastic force in the adjustment screw itself, so unlike conventional adjustment line backflow prevention devices, there is no need for a locking screw, reducing the number of parts. I can figure it out.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of an adjustment line backflow prevention device showing an embodiment of the present invention in a fully closed state, Fig. 2 is a front view of the adjustment screw, Fig. 3 is a side view of the adjustment screw, and Fig. 4 is a side view of the adjustment screw.
The figure is a vertical sectional view of a conventional adjustment line backflow prevention device in a fully closed state. 1 is a housing, 2 is a stopper, 3 is an adjustment screw, 4 is a spring, 7 is a stopper seat, and 13 is a slot for the adjustment screw.

Claims (1)

[Scope of utility model registration request] A cylindrical casing 1 having a stopper seat 7 on the upstream side, a stopper 2 that is provided in the casing 1 so as to be movable in the axial direction and seats on and leaves the stopper seat 7, and a downstream side inside the casing 1. An adjustment line consisting of a cylindrical adjustment screw 3 screwed into the body, and a spring 4 interposed between the stopper 2 and the adjustment screw 3 to bias the stopper 2 to the stopper seat 7. In the backflow prevention device, the adjusting screw 3 is formed with a split groove 13 along its axial direction so that the diameter can be freely contracted and expanded, and the outer diameter of the adjustment screw 3 is set to be slightly larger than the inner diameter of the casing 1. An adjustment line backflow prevention device featuring: