JPH02157060A - Relief valve for power-driven sprayer - Google Patents

Abstract

PURPOSE:To reduce the weight of a hose by imparting a resilience to the rear end of a piston in the valve closing direction, making the total pressure receiving area in the valve opening direction of a piston valve body larger than that in the vale closing direction thereof and providing a resisting plate in a passage in communication with a valve hole. CONSTITUTION:When spraying pressure water, an adjusting spring 22 is adjusted by an adjusting screw rod 20 to impart forward motion to a piston 16 and close a valve hole 9 with a valve body 18. When terminating the spraying, the inner pressure of a main valve body 1 rises, and the pressure exerted on the piston 16 and the valve body 18 in the valve opening direction deflects an adjusting spring 22 acting on the piston 16 to move back the valve body 18 and open the valve hole 9. The pressure water then flows out from the valve hole 9 and, from a resisting plate 11 at the end of a circulating port 10, it is circulated back in a power-driven sprayer through a coupling 13 and a circulating pipe 12. At this time, although the inner pressure of the main valve body 1 is reduced, it will not fall below a predetermined value by the action of the resisting 11 with the valve hole 9 maintained in an open state. Upon restarting of the spraying, since the inner pressure of the main valve body 1 becomes even lower, the valve hole 9 is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a relief valve attached to a nozzle of a power sprayer.

[Conventional technology]

Conventionally, when spraying cleaning liquid, agricultural chemicals, etc. using a power sprayer, it is necessary to connect one end of a hose of an appropriate length to the power sprayer, and connect a spray pipe to the other end of the hose. It is being done. During such spraying work, when the cock at the spray tube is operated to stop spraying, the pressure of the power sprayer acts on the hose, so a hose that can withstand that pressure is used.

[Problem to be solved by the invention]

However, the pressure-resistant hoses used for high-pressure spraying are heavy, which makes transportation difficult, and the spraying operation lacks smoothness.

Therefore, the technical object of this invention is to reduce the weight of the hose by providing a relief valve between the power sprayer and the hose so that high pressure is not applied when spraying is stopped.

[Failure to solve the problem]

In order to solve the above problems, the present invention provides a pair of connection ports on the peripheral wall of a cylindrical valve body, and allows the piston to slide freely inside the valve body by being biased toward the rear end of the valve body relative to the connection ports. Insert the piston, provide a valve body at the tip of the piston, provide a valve body at the tip of the valve stem that faces the valve hole provided at the tip of the valve body, and apply elastic force to the rear end of the piston in the valve closing direction↓j. , the total pressure receiving area of the piston and the valve body in the valve opening direction is formed to be larger than the pressure receiving area of the valve body in the valve closing direction, and a resistance plate is provided in the passage connected to the valve hole near the valve hole. was adopted.

[Effect]

While pressurized water is being sprayed from the spray pipe, the valve body is pushed by the piston and closes the valve hole. When the spray pipe stops spraying, the pressure inside the valve body becomes -H, so the pressure in the valve opening direction acting on the piston and valve element overcomes the elastic force acting on the piston, causing the valve element to retreat and open the valve. do. When the valve is opened, the pressure water flows out from the valve hole, passes through the resistance plate in the passage, and returns to the power sprayer main body. At this time, the pressure inside the valve body decreases, but due to the action of the resistance plate at the tip of the valve hole, the pressure does not decrease below a certain level, and the valve is maintained in an open state.

When the spray pipe is opened again, the pressure within the valve body drops, resulting in a closed valve state.

[Example] An embodiment of the invention will be described based on one aspect.

As shown in FIGS. 1 and 2, a pair of connection ports 2.3 are provided in the peripheral wall of the cylindrical valve body 1.

One connection port 2 is connected to a power sprayer main body 5 via a pipe 4, and the other connection port 3 is connected to a spray pipe 7 via a hose 6.

A valve seat 8 is provided at the tip of the valve body 1, and a valve hole 9 is formed in the center of the valve seat 8. Further, a reflux port 10 is screwed to the outer periphery of the tip of the valve body 1, surrounding the valve seat 8.

A union nut 14 is screwed to this reflux port 10, and the joint pipe 13 is connected to the union nut 14 through the resistance plate 11.
Tighten. A reflux pipe 12 is connected to the joint pipe 13 . The reflux pipe 12 is connected to the reflux port 23 of the power sprayer body 5. There is a through hole 1 in the middle of the resistance plate 11.
5 is formed.

A piston 16 that slides inside the valve body 1 is provided so as to be closer to the rear end of the valve body 1 than the connection port 2.3. A valve rod 17 is provided at the tip of this piston 16,
A valve body 1 is placed at the tip of this valve stem 17 so as to face the valve hole 9.
Attach 8.

A camp-9 is screwed to the rear end of the valve body 1, and an adjustment threaded rod 20 is inserted into the center of the cap 19. A pressing plate 21 is provided at the tip of the threaded rod 20, and the piston 16
An adjustment spring 22 is interposed between the pressure plate 21 and the pressure plate 21 .

In addition, the total pressure receiving area of the piston 16 and the valve body 18 in the opening direction ↑, that is, the sum of the area of the front end surface of the piston 16 and the effective area of the valve body 18 in the valve body 1, is calculated as follows: The pressure receiving area is larger than the area of the rear end surface of the valve body 18.

The power sprayer main body release valve of the embodiment is constructed as described above, and its operation will be explained next.

While pressurized water is being sprayed from the spray pipe 7, the adjusting spring 22 is adjusted by the adjusting threaded rod 20 to apply a force in the forward direction to the piston 16, and the valve hole 9 is closed by the valve body 18. When the spray pipe 7 stops spraying, the pressure inside the valve body 1 increases, so that the pressure in the valve opening direction acting on the piston 16 and the valve body 18 overcomes the elastic force of the adjustment spring 22 acting on the piston 16. Then, the valve body 18 retreats and the valve hole 9 opens. When the valve hole 9 is opened, the pressure water flows out from the valve hole 9, passes through the resistance plate 11 at the tip of the reflux port 10, passes through the joint pipe 13 and the reflux pipe 12, and returns to the power sprayer main body 5. Alternatively, the reflux pipe 12 may be connected to the chemical liquid tank 24, and the pressure water may be returned to the chemical liquid tank 24. At this time, the pressure inside the valve body 1 decreases, but the pressure does not fall below a certain level due to the action of the resistance plate 11, and the valve hole 9 is maintained in an open state.

When the spray pipe 7 is opened again, the pressure inside the valve body 1 is further reduced, so that the valve hole 9 is closed.

The resistance plate 11 has the effect of stabilizing the operation of the valve. If this resistance plate 11 is not provided, when the spray pipe 7 is shifted from the open state to the closed state, the pressure inside the valve body 1 will rise by 2 → open the valve hole S → the pressure inside the valve body 1 will decrease → the valve hole 9 The operation of occlusion → pressure increase inside the valve body 1 is repeated, and the operation becomes unstable.

〔Effect of the invention〕

According to this invention, with the configuration in which the relief valve is provided in the main body of the power sprayer as described above, when spraying is stopped, the pressure is released by opening the butt before the pressure inside the hose becomes high. Even when performing high-pressure spraying, a low-pressure hose can be used. As a result, the port is lightweight, making it convenient to carry and work with.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the usage state of the embodiment, and FIG. 2 is a sectional view of the embodiment. 1... Valve body, 2.3... Connection port 8... Valve seat, 9...
・Valve hole, 10... Reflux port 11...
...Resistance plate, 16... Piston, 17.
... Valve stem, 18... Valve body, 2
2...Adjustment spring. Patent applicant Yamaho Giken Co., Ltd.

Claims (1)

[Claims] (1) A pair of connection ports are provided on the peripheral wall of the cylindrical valve body, a piston is slidably inserted into the valve body with the piston biased towards the rear end of the valve body from the connection ports, and the valve rod is attached to the tip of the piston. At the same time, a valve body is provided at the tip of the valve stem that faces the valve hole provided at the tip of the valve body, and an elastic force is applied to the rear end of the piston in the valve-closing direction. A relief valve for a power sprayer, in which the total pressure receiving area is larger than the pressure receiving area of the valve body in the valve closing direction, and a resistance plate is provided in the passage connected to the valve hole in the vicinity of the valve hole.