JP2003185040A - Pressure regulating valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure regulating valve capable of reducing energizing force to energize a valve element. <P>SOLUTION: This pressure regulating valve 10 is provided with a body 18 having an excess liquid port 16 formed therein, a valve seat 20 installed at the excess liquid port, a valve element 30 seated on the valve seat, a valve shaft 32 installed at the valve element extending through a flow path 11 inside the body from the valve seat 20, an energizing means 56 energizing the valve shaft 32 in the direction where the valve element is seated to the valve seat, and a piston part 42 where the surface is formed on which the liquid pressure inside the flow path acts in the same direction as the energizing direction by the energizing means. Since the liquid pressure acts from the opposite direction of the pressure acting on the valve element and the same direction of the energizing force of the energizing means, acts on the piston part, it assists the energizing means and reduces the energizing force. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure regulating valve which is connected to a flow path in a pump device such as a power sprayer or a washing machine and which regulates a discharge pressure to be constant.

[0002]

2. Description of the Related Art For example, in a power sprayer for spraying a liquid such as a pesticide, a pressure regulating valve is usually used to keep the pressure of the liquid discharged from a pump constant. As such a pressure regulating valve, one having a structure as shown in FIG. 2 is widely known. The pressure regulating valve 1 shown in FIG. 2 includes a body 2 in which an inlet 2a, an outlet 2b, and a residual liquid port 2c which are communicated with each other inside are formed. A valve seat 3 is attached to the residual liquid port 2c of the body 2, and the valve body 4 is seated from below the valve seat 3. A valve rod 5 extends upward from the valve body 4, penetrates through the body 2, and projects upward. An adjusting nut 7 is screwed onto the upper end of the valve rod 5,
A plurality of disc springs 8 are laminated between the adjusting nut 7 and the body 2 so as to surround the valve rod 5 in a compressed state. The periphery of the plurality of disc springs 8 is surrounded by a spring tube 9 connected to the upper portion of the body 2.

When such a pressure regulating valve 1 is used in a power sprayer, although not shown, the inlet 2a is a discharge port of the pump, the outlet 2b is a spray nozzle, and the residual liquid port 2c is a liquid tank for storing liquid. Connected to. When the pump is driven to supply the liquid from the liquid tank to the inlet 2a of the pressure regulating valve 1, the disc spring 8 biases the valve rod 5 upward when the liquid pressure is lower than a predetermined value. The valve body 4 is seated on the valve seat 3, and the liquid in the body 2 is discharged as it is from the outlet 2b. On the other hand, when the hydraulic pressure in the body 2 exceeds a predetermined value, the disc spring 8
When the urging force of 1 is overcome, the valve body 4 separates from the valve seat 3 and a part of the liquid in the body 2 flows out from the residual liquid port 2c and is returned to the liquid tank. Due to this outflow, the liquid pressure in the body 2 is lowered, and when it returns to a predetermined value, the valve body 4 is seated again on the valve seat 3, and the outflow of the liquid in the body 2 from the residual liquid outlet 2c is stopped.
In this way, the discharge pressure of the liquid discharged from the outlet 2b is kept constant, and stable spraying can be performed. By changing the position of the adjusting nut 7 with respect to the valve rod 5 and adjusting the initial load generated in the disc spring 8,
The predetermined value of the hydraulic pressure can be set to a desired value.

[0004]

In the pressure regulating valve 1 as described above, it is desirable to reduce the spring force of the disc spring 8 while maintaining the discharge pressure of the pressure regulating valve. This is because it is possible to reduce the stress generated in each component of the pressure regulating valve 1 and the operating force of the adjusting nut 7. Therefore, the hole diameter of the valve seat 3 is made smaller or the outer diameter of the valve rod 3 is made larger so that the area of the valve body 4 facing from the valve seat 3 into the body 2, that is, the liquid in the valve body 4. Means for reducing the area under pressure have been conventionally considered.

However, if the hole diameter of the valve seat 3 is reduced, the capacity performance of the pressure regulating valve itself may be affected. Further, when the outer diameter of the valve rod 3 is increased, there is a problem that the cost is increased and the pressure regulating valve 1 is increased in size.

Therefore, the present invention has been made in view of such circumstances, and it is possible to reduce the urging force for urging the valve body against the valve seat while maintaining the capacity performance. The purpose is to provide a pressure regulating valve.

[0007]

In order to achieve the above object, a pressure regulating valve (10) according to the present invention has a flow passage (1) inside.
1) is formed and a body (18) is formed with a residual liquid port (16) for discharging a part of the liquid in this flow path.
A valve seat (20) provided at the residual liquid port (16), a valve body (30) seated on the valve seat (20), and a valve body (30) attached to the valve seat (20). The flow path of the body (1
1) extending through 1), a biasing means (56) for biasing the valve rod (32) in a direction in which the valve body (30) is seated on the valve seat (20), and the valve rod ( 32), a piston portion (42) having a fluid pressure acting surface on which the pressure of the liquid in the flow channel (11) acts in the same direction as the urging direction of the urging means (56), and the body And a guide portion (46) provided on (18) and surrounding the piston portion (42) to slidably guide the piston portion (42).

In this pressure regulating valve (10), the valve body (3
0) and the piston portion (42) act in opposite directions of the hydraulic pressure in the flow channel (11). In particular, the direction of the hydraulic pressure acting on the piston portion (42) is the same as the urging direction of the urging means (56) such as a spring, so that the piston portion (42)
The force due to the hydraulic pressure acting on acts as an auxiliary force for the biasing force of the biasing means (56). Therefore, even when the discharge pressure is the same as in the conventional configuration, the urging force of the urging means (56) can be reduced as compared with the conventional configuration.

Further, the piston portion is preferably a sleeve (42) which can be attached to and detached from the valve rod (32).

Since the piston portion is formed by the detachable sleeve (42), only the sleeve (42) can be applied with an abrasion-resistant material such as a material obtained by spraying ceramics, thereby providing abrasion resistance. It is possible to reduce costs while improving. When the sleeve (42) is worn by friction with the guide portion (46), the sleeve (4
Since 2) can be replaced with a new one, the service life of the pressure regulating valve (10) as a whole can be extended.

Further, in the pressure regulating valve (10) of the present invention, the seal member (48) disposed in the gap between the piston portion (42) and the guide portion (46) and the gap between the seal member (48). (47) A pressing member (5
0) and a coil spring (52) which surrounds the valve rod (32) and is disposed in the flow path (11) and presses the pressing member (50) toward the seal member (48), and which is a valve seat (20). ) Side, the outer diameter of the coil spring (52) is preferably reduced.

With the above arrangement, it is possible to prevent the seal member (48) from being pressed by the coil spring (52) via the pressing member (50) and the seal member (48) from falling out of the gap (47). You can Further, since the outer diameter of the coil spring (52) is reduced toward the valve seat (20) side, the flow path (1) blocked by the coil spring (52).
The portion 1) is small, and the flow of the liquid in the flow path (11), particularly the flow from the valve seat (20) to the residual liquid port (156) can be smoothed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In this specification, terms such as “upper” and “lower” are based on the state shown in the drawings and are for convenience.

FIG. 1 is a diagram showing an embodiment of a pressure regulating valve according to the present invention. The pressure regulating valve 10 according to the present embodiment is connected to a flow path (not shown) on the discharge side of a pump in a power sprayer, and as shown in the figure, has an inlet 12 on the side.
And an outlet 14 and a body 18 having a residual liquid port 16 formed in the lower portion. The inlet 12, the outlet 14, and the residual liquid port 16 communicate with each other through a T-shaped flow passage 11 inside the body 18, the inlet 12 being a discharge port of a pump in a power sprayer, the outlet 14 being a spray nozzle, The residual liquid port 16 is connected to the liquid tank via a pipe, a hose, or the like.

A valve rod guide 19 and a valve seat 20 are arranged in this order from the upper side in a downward flow passage 11 communicating with the residual liquid outlet 16 of the body 2.
The washer 22 is fitted in and fixed by a fixing member 24 screwed to the inner surface of the lower end of the flow path 11. The valve rod guide 19 surrounds a valve rod 32, which will be described later, and guides the valve rod 32 slidably in the longitudinal direction thereof. A plurality of through-holes 28 that communicate with and are formed.

A truncated cone-shaped valve element 30 is seated on the valve seat 20 from below. The valve seat 30 has a valve seat 2
A valve rod 32 having an outer diameter smaller than the hole diameter of 0 is attached, and the valve body 30 is fixed by a fixing nut 34 screwed to the lower end of the valve rod 32. The valve rod 32 penetrates through the valve seat 20, the guide hole 26 of the valve rod guide 19, and the inside of the body 18, and projects above the body 18. At the portion of the valve rod 32 that penetrates the upper portion of the body 18, a pin 36
Has penetrated. Pin 3 protruding from the outer peripheral surface of the valve rod 32
Both ends of 6 are guided in the longitudinal direction of the valve rod 32 by grooves 38 formed in the upper portion of the body 18, and rotation of the valve rod 32 around the axis is prevented.

In addition, the pin 3 is an intermediate portion of the valve rod 32.
A large diameter portion 40 having an outer diameter slightly larger than the outer diameter of the valve rod 32 is formed immediately below the valve rod 6, and is slidably fitted into the through hole 39 in the upper portion of the body 18 to form the valve rod 32. Are guided along the longitudinal direction. Valve rod 32
Further, a cylindrical sleeve (piston portion) 42 is detachably fitted to the outer peripheral surface of the sleeve, and is fixed by a C-shaped snap ring 44 so that the upper end surface of the sleeve 42 contacts the lower end surface of the large diameter portion 40. Has been done. Therefore, the sleeve 42 is located above the flow path 11 of the body 18.

A hole that surrounds the sleeve 42 fixed to the valve rod 32 and guides the sleeve 42 slidably in the longitudinal direction of the valve rod 32 is formed in a portion of the body 18 facing the valve seat 20. It is formed as a guide portion 46. Since the guide portion 46 is opened downward, the lower end surface of the sleeve 42 faces the flow passage 11 inside the body 18.

The lower portion of the guide surface (inner peripheral surface) of the guide portion 46 is enlarged in diameter, and a gap 47 is formed between the guide portion 46 and the outer peripheral surface of the sleeve 42. A ring-shaped seal member 48 is disposed in the gap 47 to prevent the liquid from leaking from between the sleeve 42 and the guide portion 46. The lower surface of the seal member 48 is supported by a collar (pressing member) 50 that slidably surrounds the sleeve 42 and covers the lower end opening of the gap 47. Between the lower end surface of the collar 50 and the upper end surface of the valve rod guide 19, a conical coil spring 52 diverging upward is provided so as to surround the valve rod 32 in a compressed state. The lower end of the conical coil spring 52 is in contact with the inner peripheral portion of the upper end surface of the valve rod guide 19. The conical coil spring 52 presses the collar 50 against the inner surface of the body 18,
The seal member 48 is prevented from falling out of the gap 47.

An adjusting nut 54 is screwed onto the upper end portion of the valve rod 32, and between the adjusting nut 54 and the body 18,
A plurality of disc springs (biasing means) 56 are stacked in a compressed state surrounding the valve rod 32. A spring seat 57 is arranged between the adjusting nut 54 and the uppermost disc spring 56. The periphery of the plurality of disc springs 56 is surrounded by a spring cylinder 58 connected to the upper portion of the body 18. The adjusting nut 54 changes its position with respect to the valve rod 32 to adjust the initial load generated in the disc spring 56, so that the body 1 is adjusted.
This is for setting the discharge pressure from 8 to a desired value.

Next, the operation of the present invention when the pressure regulating valve 10 described above is used in a power sprayer will be described.

When the pressure regulating valve 10 is used in a power sprayer, as described above, the inlet 12 of the body 18 is the discharge port of the pump in the power sprayer, the outlet 14 is the spray nozzle, and the residual liquid port 16 is. Each is connected to the liquid tank via a pipe or a hose.

When the pump is in a stopped state, liquid is not supplied from the supply tank to the pressure regulating valve 10, and in the pressure regulating valve 10, the disc spring 56 urges the valve rod 32 upward. The body 30 is seated on the valve seat 20.

When the liquid is supplied from the supply tank to the pressure regulating valve 10 by driving the pump from this state, the liquid is supplied to the body 18
From the inlet 12 to the flow path 11. At this time, body 1
The liquid in 8 passes through the through hole 28 of the valve rod guide 19,
The valve body 30 is in contact with the upper surface of the valve body 30 and presses it downward. Maintaining the seated state, the liquid proceeds straight through the flow path 11 and is discharged only from the outlet 14 of the body 18. At this time, most of the liquid passes through the outside of the conical coil spring 52, but the outer diameter of the conical coil spring 52 is smaller toward the lower side, and the lower portion of the flow path 11 is wide open, so that the liquid The flow will be smooth. The discharged liquid is sprayed from the spray nozzle.

Further, the pressure of the liquid from the pump rises due to the pulsation of the pump or other factors, and the body 18
When the hydraulic pressure inside exceeds a predetermined value, the force from the liquid acting on the valve element 30 exceeds the spring force of the disc spring 56, and the valve element 30 moves downward together with the valve rod 32. As a result, the valve body 3
0 separates from the valve seat 20 and a part of the liquid in the body 18 flows out to the residual liquid port 16 as a residual liquid from the gap between the valve seat 20 and the valve body 30. The residual liquid that has flowed out is returned to the liquid tank via a predetermined pipe or the like. At this time, since the through hole 28 of the valve rod guide 19 is provided around the lower end of the conical coil spring 52, the conical coil spring 52 moves from the inside of the body 18 to the valve seat 20.
The liquid flows smoothly without obstructing the liquid flow to the.

The liquid pressure in the body 18 decreases due to the outflow of the residual liquid, and returns to a predetermined value or less. Therefore, the valve rod 32 is pulled up by the biasing force of the disc spring 56, the valve body 30 is seated on the valve seat 20, the outflow of the liquid from the residual liquid port 16 is stopped, and the liquid is again discharged only from the outlet 14 of the body 18. It will be discharged. In this way, the discharge pressure of the pressure regulating valve 10,
That is, the pressure of the liquid discharged from the outlet 14 of the body 18 is maintained substantially constant, and the spray state of the liquid from the spray nozzle becomes stable.

By the way, the hydraulic pressure generated in the body 18 is
Not only on the surface of the valve body 30 facing the inside of the body 18 from the valve seat 20 (the fluid pressure acting surface of the valve body 30), but also on the surface of the sleeve 42 facing the valve seat 20 (the fluid pressure acting surface of the sleeve 42). To work. Therefore, the area of the fluid pressure acting surface of the valve body 30 is S
1, the area of the hydraulic pressure acting surface of the sleeve 42 is S2, the body 1
If the hydraulic pressure generated in 8 is P, the load W applied to the disc spring 56 via the valve rod 32 is W = P * S1-P * S2.
Therefore, the pressure is reduced by (P × S2), that is, the pressure generated on the fluid pressure acting surface of the sleeve 42. Of course, in order for this relationship to hold, S1 must be larger than S2. If P is a predetermined value (discharging pressure) of the hydraulic pressure, W is an urging force required for the disc spring 56. Therefore, as compared with the conventional configuration of FIG. The biasing force W of the disc spring 56 is reduced by (P × S2). Therefore, as the disc spring 56 itself, a weak spring force or a small one can be used. The downsizing of the disc spring 56 contributes to downsizing and weight saving of the pressure regulating valve 10 itself. Further, since the stress generated in each component of the pressure regulating valve 10 is reduced, the life of each component is extended. Furthermore, since the operating force of the adjusting nut 54 can be reduced, the discharge pressure adjusting work can be easily performed.

In the pressure regulating valve 10 described above, since the sleeve 42 slides along the guide surface of the guide portion 46 as a piston, it is considered that the sleeve 42 is worn. However, in the illustrated embodiment, the sleeve 4
Since 2 can be attached to and detached from the valve rod 32, the sleeve 42 can be replaced with a new one when wear or other damage occurs, and the service life of the pressure regulating valve 10 as a whole can be extended. .

When replacing the sleeve 42, first,
The fixing nut 34 screwed to the lower end of the valve rod 32 is removed, and the valve element 30 is removed from the valve rod 32. Then, the body 18
Of the washer 2 fitted in the flow path by removing the fixing member 24 screwed onto the inner surface of the flow path leading to the residual liquid port 16 of
2, the valve seat 20 and the valve stem guide 19 are removed, and the conical coil spring 52, the collar 50 and the seal member 48 are removed from the valve stem 32. After that, attach the C-shaped retaining ring 44 to the valve rod 3
2, and the sleeve 42 accommodated in the guide portion 46 is taken out. Assembling after replacing the sleeve 42 may be performed by reversing the above-described disassembly procedure.

As described above, since the sleeve 42 is separate from the valve rod 32, it is possible to apply a wear-resistant material such as a ceramic sprayed material to only the sleeve 42. Since the ceramics are expensive, the valve rod 32
And rather than making the sleeve 42 entirely made of ceramic,
It is possible to reduce costs while improving wear resistance. Further, if various sleeves 42 having different areas of pressure acting surface are prepared, the pressure regulating valve 10 having various pressure specifications can be provided by simply changing the sleeve 42 while using the common ones for the other components of the pressure regulating valve 10. It becomes possible to do.

The preferred embodiments of the present invention have been described above in detail, but it goes without saying that the present invention is not limited to the above embodiments.

For example, in the above embodiment, the case where the valve rod 32 and the sleeve 42 are separate bodies has been described, but in the present invention, both may be integrally formed. Also in this case, it is possible to reduce the urging force of the urging means for urging the valve body, such as a disc spring.

Further, in the above embodiment, the disc spring 56 is used as the biasing means, but a compression coil spring or the like can also be used. This is because the reduction of the biasing force of the biasing means reduces the need to use a strong spring such as a disc spring.

Further, in the above embodiment, the pressure regulating valve is applied to the power sprayer, but the pressure regulating valve of the present invention can be applied to various devices which require adjustment so that the liquid pressure becomes constant. Is.

[0035]

As described above, according to the present invention,
Since the hydraulic pressure generated inside the body acts in the direction opposite to the valve body and the piston or the sleeve provided on the valve rod, the biasing force that tries to seat the valve body on the valve seat acts on the sleeve. It is reduced by the amount of hydraulic pressure.

Therefore, as compared with the pressure regulating valve of the type in which the valve rod is not provided with the piston or the sleeve, when the predetermined value of the discharge pressure to be made constant is the same, the urging means is downsized, and consequently the urging means is downsized. It is possible to reduce the size and weight of the pressure regulating valve itself. Further, by reducing the urging force of the urging means, it is possible to reduce the stress generated in each component of the pressure regulating valve and to improve the operability of the pressure regulating valve, which can extend the service life of the pressure regulating valve. It will be possible. Further, since it is not necessary to reduce the hole diameter of the valve seat or thicken the valve rod, the performance of the pressure regulating valve itself is not deteriorated.

In particular, when the pressure regulating valve according to the present invention is applied to a portable power spraying machine such as a backpack type, it greatly contributes to reduction in size and weight of the power spraying machine and improvement in spraying workability. .

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a pressure regulating valve according to the present invention.

FIG. 2 is a sectional view showing a configuration of a conventional pressure regulating valve.

[Explanation of symbols]

10 ... Pressure regulating valve, 11 ... Flow path, 16 ... Spill port, 18 ... Body, 20 ... Valve seat, 30 ... Valve body, 32 ... Valve rod, 42 ... Sleeve (piston part), 46 ... Guide part, 48 ... Seal member, 50 ... Collar (pressing member), 52 ... Conical coil spring, 56 ... Disc spring (biasing means).

Claims (3)

[Claims] 1. A flow channel (11) is formed inside,
A residual liquid port (1) for discharging a part of the liquid in the flow channel (11)
6) formed body, a valve seat (20) provided in the residual liquid port (16), a valve body (30) seated on the valve seat (20), and the valve A valve rod (32) attached to the body (30) and extending from the valve seat (20) through the flow passage (11) of the body, and the valve body (30) seated on the valve seat (20) Urging means (56) for urging the valve rod (32) in a direction in which the flow path is provided in the valve rod (32) in the same direction as the urging direction of the urging means (56). A piston part (42) formed with a hydraulic pressure acting surface on which the pressure of the liquid in (11) acts, and the piston part (4) provided on the body (18).
A pressure regulating valve comprising: a guide portion (46) surrounding the second portion and slidably guiding the piston portion (42). 2. The pressure regulating valve according to claim 1, wherein the piston portion is a sleeve (42) which can be attached to and detached from the valve rod (32). 3. A seal member (48) disposed in a gap (47) between the piston portion (42) and the guide portion (46), and the gap (47) of the seal member (48). And a pressing member (50) for preventing the falling of the pressing member (50) around the valve rod (32) and arranged in the flow path (11).
The pressure regulating valve according to claim 1 or 2, further comprising: a coil spring (52) that is pressed toward the 8) side, the coil spring (52) having a smaller outer diameter toward the valve seat (20) side. .