JP2003186550A - Self-actuated pressure reducing valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-actuated pressure reducing valve, that can reliably avoid the breakage of a downstream side piping by closing a valve body by an independent operation from an outside in the event of the trouble of the resistance increase at a sliding portion or the clogging of a first and a second passages. <P>SOLUTION: If a trouble occurs, a primary operation shaft 30 and an operation machine side clutch 29 are rotated in the direction, that closes the valve manually or by the self operation of an electric operation machine 31, rotation is conveyed into a valve side clutch 28 and a secondary operation shaft 27 to rotate the shaft in the direction that closes the valve, and concurrently a bevel gear 25, a bevel gear 24 and an internal thread top 23 are rotated in the direction that closes the valve, thus lowering a valve rod 12 to close a valve bore 3 with a valve body 4. Thereby, the situation is reliably avoided surely where the pressure in a secondary side B exceeds the design value for the downstream side piping and breaks the downstream side piping. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-acting pressure reducing valve suitable as a control valve for controlling water systems such as tap water, agricultural water and industrial water. 2. Description of the Related Art Conventionally, as a self-operated pressure reducing valve, for example, a V port type pressure reducing valve shown in FIG. 2 has been known. In this self-acting pressure reducing valve, the inside of the valve box 1 is
A plurality of valve holes 3, 3 are formed by vertically penetrating the valve box valve seat 2 and partitioned by a secondary side A and a secondary side B, and these valve holes 3, 3 are opened and closed by a valve body 4. . The valve body 4 is the valve box 1
And a partition member 6 formed of a diaphragm interposed between the spring 11 and the valve cover 5.
Is always urged downward. And valve cover 5
A sealed space 7 surrounded by the partition member 6 and the filter 8A
And a throttle valve 8B in series through a first passage 8
It is connected to the secondary side B via a second passage 10 which is connected to the secondary side A and in which a well-known pilot valve 9 is provided. [0003] The valve element 4 is provided concentrically opposite the upper part of the valve box valve seat 2 and is fixed to a central main part 4A with a partition member 6 interposed therebetween. Valve seat 4 fixed to the lower surface of upper body 4B and main body 4A
C, the upper end of a valve stem 12 extending vertically through the center is slidably supported by a bearing 5A attached to the valve cover 5, and the lower end is a center hole of the valve box valve seat 2. It is slidably inserted into 2A. A valve box valve seat 2 is provided on the valve body sheet 4C.
, A plurality of spool valves 4D, 4D concentrically opposed to the plurality of valve holes 3, 3 formed therein are mounted so as to protrude downward. That is, the valve body 4 includes the main body 4A, the upper body 4B,
It is constituted by a valve body seat 4C and spool valves 4D, 4D. At the lower end of each of the spool valves 4D, 4D, a downward conical valve head 4d which enters and exits the valve holes 3, 3 is formed. With such a configuration, the second passage 10
When the pressure on the secondary side B, which is loaded on the pilot valve 9 as the pilot pressure via the pilot valve, becomes higher than the set pressure of the pilot valve 9, the pilot valve 9 operates in the closing direction, and the flow rate passing through the pilot valve 9 Decreases. Since water flows into the closed space 7 from the primary side A via the first passage 8, the closed space 7
Pressure increases. Therefore, the cooperation between the increased pressure and the spring force of the spring 11 pushes down the partition member 6, the valve rod 12, and the valve body 4, and the valve body sheet 4C
Of the spool valve 4D, 4D and the valve head 4d of the spool valve 4D begin to close the valve hole 3. For this reason, the flow rate passing through the valve hole 3 decreases, and the pressure on the secondary side B starts to decrease and approaches the set pressure of the pilot valve 9. When the pressure on the secondary side B becomes lower than the set pressure of the pilot valve 9, the pilot valve 9 operates in the opening direction, and the flow rate passing through the pilot valve 9 increases. Even in this case, water flows into the closed space 7 from the primary side A, but the closed space 7 is depressurized by an increase in the flow rate from the closed space 7 to the secondary side passing through the pilot valve 9. . Therefore, at the beginning of the fully closed state, a load is applied to the lower peripheral surface a of the partition member 6 and the outer peripheral slope b of the valve seat 4C.
The partition member 6, the valve body 4 and the valve rod 12 are pushed up by the fluid pressure on the secondary side A, and subsequently the fluid pressure on the primary side A is applied to the lower surface of the valve seat 4C, so that the partition member 6, the valve body 4 and the valve The rod 12 is further pushed up, and the valve head 4d of the spool valve 4D moves upward. [0006] Since the valve head 4d of the spool valve 4D is formed in a downward conical shape, the flow rate passing through the valve holes 3, 3 increases in proportion to the rising amount of the valve head 4d. Due to the characteristics, the fluid on the primary side A can flow to the secondary side B. When the fluid on the primary side A flows to the secondary side B, the pressure on the secondary side B starts to rise and approaches the set pressure of the pilot valve, and the pressure on the secondary side B becomes the set pressure of the pilot valve 9. If it becomes higher, the above-described operation is repeated to reduce the pressure by itself. The fluid on the primary side A flows from the plurality of valve holes 3 and 3 to the secondary side B, so that the energy of the flow is dispersed. Since the valve head 4d of the spool valve 4D that enters and exits the holes 3, 3 is formed in a downward conical shape, the valve head 4d
The flow characteristics with respect to the opening degree are improved to a proportional flow state, so that the valve can be stabilized. That is, when the pressure on the secondary side B becomes higher than the set pressure of the pilot valve 9, the partition member 6 and the valve body 4 are pushed down to lower the valve rod 12, thereby closing the valve.
When the pressure on the secondary side B becomes lower than the set pressure of the pilot valve 9, the partition member 6 and the valve body 4 are pushed up, and the valve rod 12 is moved up to open the valve by itself. However, in the conventional pressure reducing valve, for example, troubles such as an increase in the resistance of the sliding portion and clogging of the first passage 8 and the second passage 10 are caused. Occurs, the valve cannot be closed and pressure reduced by an independent operation from the outside. Therefore, when the pressure on the secondary side B exceeds the design value of the downstream side pipe, the downstream side pipe may be damaged. [0010] The present invention has been made in view of such circumstances, and any troubles such as an increase in the resistance of the sliding portion and clogging of the first and second passages occur. Even if it does, an object of the present invention is to provide a self-acting pressure reducing valve that can reliably prevent damage to a downstream pipe by closing a valve body by an independent operation from the outside. In order to achieve the above object, a self-acting pressure reducing valve according to the present invention has a valve box in which the inside of a valve box is divided into a primary side and a secondary side by a valve box valve seat. A valve body that opens and closes a valve hole formed in the valve box valve seat is integrally connected to a partition member interposed between the valve box and the valve lid, and a sealed space surrounded by the valve lid and the partition member is formed. A first passage is connected to a primary side of the valve box, and a pilot valve is connected to a secondary side of the valve box through a second passage provided with a pilot valve. In a self-acting pressure reducing valve having a valve stem that moves forward and backward when the valve body opens and closes by itself, the valve stem that follows the self-opening and closing of the valve body is allowed to move forward and backward, and the valve stem is operated by itself. Opening and closing means for moving the valve body forward and backward to open and close the valve body. And According to the present invention, even if a trouble such as an increase in the resistance of the sliding portion or clogging of the first passage and the second passage occurs, independent opening and closing from the outside is possible. By closing the valve body by the means self-operation, damage to the downstream pipe can be reliably avoided. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of a self-acting pressure reducing valve according to the present invention. The same or corresponding parts as those in the conventional example of FIG. 2 are denoted by the same reference numerals, and the description of the overlapping structure and operation will be omitted. In FIG. 1, reference numeral 20 denotes opening / closing means. The opening / closing means 20 is a valve stem 1 that follows the opening and closing of the valve body 4 by itself.
2 for allowing the valve rod 4 to move forward and backward and for moving the valve rod 12 forward and backward to open and close the valve body 4 by a self-operation. Female screw part 22 screwed to the part 21
, A bevel gear 24 fixed to the outer periphery of the female screw top 23 so as to be rotatable at the same time, a bevel gear 25 that meshes orthogonally with the bevel gear 24, and a bevel gear 25 that can be simultaneously rotated. , A secondary operation shaft 27 rotatably supported by a bearing 26, a valve-side clutch 28 rotatably provided on the secondary operation shaft 27, and a valve-side clutch 2.
8, a primary operating shaft 30 provided rotatably with the operating device-side clutch 29 and rotatably provided on the operating device-side clutch 29 and corresponding to the secondary operation shaft 27 concentrically therewith; An operating device 31 for rotating the motor 30 forward or reverse around its axis manually or electrically is provided with a bearing 32 for rotatably supporting the female screw top 23. These are housed in a case 33, and the case 33 is It is detachably attached to the upper part of. Valve side clutch 28 and operating device side clutch 29
Is constituted by a well-known sliding meshing clutch, and the secondary operation shaft 27 and the valve-side clutch 28 are rotated at a predetermined rotation angle when the valve body 4 opens and closes by itself and as the valve rod 12 moves up and down following the self-opening and closing. Even when rotating within the range, the valve stem 1 that follows the self-opening / closing of the valve body 4 due to slippage between the claws of the valve-side clutch 28 and the operating device-side clutch 29 that does not interfere with each other.
2 is allowed and the primary operating shaft 30 and the operating device-side clutch 29 are rotated manually or by the self-operation of the electric operating device 31, the rotation angle region outside the predetermined rotation angle range. As a result, engagement of the pawl of the operating device side clutch 29 with the pawl of the valve side clutch 28 occurs,
The rotation of the primary operating shaft 30 and the operating device side clutch 29 is transmitted to the valve side clutch 28 and the secondary operating shaft 27 and rotated, and the bevel gear 25, the bevel gear 24 and the female screw top 23 are rotated forward and reverse. The valve rod 4 is opened and closed by moving the valve rod 12 up and down. With this configuration, when the self-powered pressure reducing valve is in a normal state, the pressure can be controlled by the same operation as that of the conventional self-powered pressure reducing valve. On the other hand, if the resistance of the sliding portion increases,
Even if a trouble such as clogging of the first passage 8 or the second passage 10 occurs, the valve body 4 is closed by the independent operation of the independent opening / closing means 20 from outside.
Damage to the downstream pipe can be reliably avoided. That is, the primary operating shaft 30 and the operating device-side clutch 29 are rotated in the valve closing direction by manual operation or the self-operation of the electric operating device 31, and this rotation is transmitted to the valve-side clutch 28 and the secondary operating shaft 27 to be transmitted to the valve. Rotate in the closing direction and at the same time bevel gear 2
5. By rotating the bevel gear 24 and the female screw top 23 in the valve closing direction, the valve rod 12 can be lowered to close the valve hole 3 with the valve body 4. Therefore, it is possible to reliably avoid a situation in which the pressure on the secondary side B exceeds the design value of the downstream side pipe and the downstream side pipe is damaged. In FIG. 1, the large bevel gear 24 is fixed to the female screw top 23 and the small bevel gear 25 is rotatably provided on the secondary operation shaft 27. The small and large bevel gear 25 may be rotatably provided on the secondary operation shaft 27. As described above, since the self-acting pressure reducing valve according to the present invention is constituted, the following special effects can be obtained. That is, even if a trouble such as an increase in the resistance of the sliding portion or a clogging of the first passage or the second passage occurs, the self-operation of the independent opening / closing means from outside can be performed. The valve can be closed by
It is possible to reliably avoid a situation in which the pressure on the next side exceeds the design value of the downstream pipe and damages the downstream pipe.

[Brief description of the drawings] FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention. FIG. 2 is a longitudinal sectional view of a conventional example. [Explanation of symbols] 1 Valve box 2 Valve seat 3 Valve hole 4 Valve 5 Valve lid 6 Partition members 7 enclosed space 8 First passage 9 Pilot valve 10 Second passage 12 Valve stem 20 Opening / closing means A Primary side B Secondary side

Continuation of front page    F term (reference) 3H059 AA02 AA06 AA12 BB07 BB21                       BB31 BB35 CA05 CA12 CA13                       CC01 CD04 DD09 EE01 FF02                 5H316 AA07 BB08 DD06 DD18 EE02                       EE07 EE10 EE12 HH14 KK02                       LL05

Claims (1)

Claims 1. An interior of a valve box is divided into a primary side and a secondary side by a valve box valve seat, and a valve body that opens and closes a valve hole formed in the valve box valve seat is a valve. A sealed space surrounded by the valve cover and the partition member is connected to a primary side of the valve box through a first passage, and is integrally connected to a partition member interposed between the box and the valve cover. A valve rod is connected to the secondary side of the valve box through a second passage provided with a valve, and a valve rod that moves forward and backward following the self-opening and closing of the valve body is attached to the valve body. The self-acting pressure-reducing valve includes an opening / closing means that allows the valve rod to move forward and backward following the opening and closing of the valve element by itself, and that opens and closes the valve element by moving the valve rod by itself. A self-acting pressure reducing valve characterized by the above-mentioned.