CN1037382A - Valve - Google Patents

Abstract

A kind of control valve unit comprises that has a valve seat that makes the liquid flow hole that liquid inflow entrance compartment communicates with liquid outflow opening compartment, with a valve body of controlling the ON/OFF liquid flow hole along the valve seat axially reciprocating, upper reaches and dirty part form, and form the pressure chamber with predetermined volume between upper reaches and dirty restriction branch.

Description

Valve

The present invention relates to a kind of control valve unit, this device is applicable to the shape adjustment valve.

In recent years, usually be used under the little perforate situation such as this class control valve unit of modulating valve.This is that (being controlled peak rate of flow and the ratio of controlled minimum discharge) must be set very greatly because the rangeability of its regulated variable.

In this class common valve device, thereby, tremble, cavitation can occur owing under stress produce in valve inlet and outlet both sides when controlled when producing very big pressure reduction under little perforate situation as the liquid of controlled liquid.The contact segment of valve body and valve seat and seat surface are by local etching.Thereby valve often loses its function, Given this plants situation, once adopts many kinds of countermeasures.

Japan's 57-18070 publication has been introduced a kind of control valve unit of routine, with it as this class valve.

This conventional valve gear can prevent to produce cavitation under little perforate situation, but can not be by opening/close valve with the flow control of valve body part control flow rate at once.Be exactly under valve body and valve seat contact segment and seat surface, to form a pressure chamber in particular, opening/when closing valve, below the pressure chamber, form the throttling part.Consequently the axial dimension of valve body is very big and can not obtain low shape valve.

The purpose of this invention is to provide a kind of low shape valving, this device can prevent the corrosion between valve body and valve seat contact segment and the seating face.

In order to reach above-mentioned purpose of the present invention, the invention provides a kind of control valve unit, this device comprises: valve seat and valve body.Valve seat has liquid flow hole, and this hole is connected liquid inlet compartment and liquid outlet compartment, and valve body is controlled opening/closing of liquid flow hole along the valve seat axially reciprocating.Wherein form upper and lower throttling part, and between upper and lower restriction is divided, form pressure chamber with predetermined volume.

Under little perforate situation, form two throttling parts according to the present invention at the upper reaches of pressure chamber and dirty both sides.The axial dimension of valve body can be reduced.In addition, also can be prevented from the cavitation that forms between valve body and valve seat contact segment and the seat surface under the little perforate situation.

Fig. 1 is the sectional drawing of the critical piece of the control valve unit in the one embodiment of the invention;

Fig. 2 is the partial enlarged drawing of A part among Fig. 1;

Fig. 3 is the sectional drawing of the critical piece of the control valve unit in another embodiment of the present invention;

Details are as follows for most preferred embodiment of the present invention:

Fig. 1 and Fig. 2 are the control valve units in the one embodiment of the invention.

As shown in Figure 1, 2, reference number 1 expression is to the valve body of both direction opening.Inlet compartment (following compartment) 3 and outlet compartment (going up compartment) 4 limit with the compartment in the valve body 12.On the next door 2 of valve body 1, be provided with annular mounting hole 5 to opening.The seat ring 7 that has liquid flow hole 6 is fixed on the looping pit 5.Liquid flow hole 6 on the seat ring 7 can make compartment 3 communicate with compartment 4.Valve body and valve seat contact segment are that surface of contact 7a forms on liquid flow hole 6.Reference number 8 is illustrated in the valve plug that its end portion has flow control part 8a.Liquid flow hole 6 is opened/closed to valve plug 8 along seat ring 7 axially reciprocatings.Annular groove B is limited between the surface and the surface as the concave surface of surface of contact 7a of valve plug 8, has the long-pending pressure chamber of predetermined content under the little perforate state thereby formed.Circular groove 10 and 11 is located at 9 upper reaches, pressure chamber and the dirty both sides that enter immediately as the throttling part.More particularly, two circular grooves 10 and 11 basins that have are respectively less than the drainage area that is limited between contact surface of valve seat 7a and the valve body surface of contact 86, and the axial dimension of circular groove 10 (chock length) is identical with circular groove 11 almost.

In having the control valve unit of said structure, because under the situation of very little perforate, valve seat upper reaches and dirty both sides have formed circular groove 10 and 11(throttling part), the conventional valve that the axial dimension of valve plug 8 and restriction branch are located under valve seat and the pressure chamber compares, and can reduce.

In addition, according to present embodiment, because pressure chamber 9 has been arranged, and the area of contact between valve seat contact segment 8b and the seat surface 7a has also reduced.Therefore, opening/when closing valve, valve plug 8 drives steadily.

Valve flow control in the present embodiment is described below:

In order to close this valve, make with valve seat contact segment 8b and seat surface 7a to be adjacent to, promptly cut stifled by liquid flow hole 6 fully from the liquid stream that inlet compartment 3 flows to outlet compartment 4 like this.At this moment, inlet compartment 3 and outlet compartment 4 respectively have pressure P 1(master to press) and 2(pressure of pressure P), P2 need satisfy the condition of P1＞P2.When valve plug 8 moves up the situation of very little perforate (promptly form) slightly, and valve seat contact segment 8b and seat surface 7a between form a gap.Liquid flows to outlet compartment 4 by upper reaches circular groove 10, pressure chamber 9 and dirty circular groove 11 from inlet compartment 3.In such cases, pressure reduction is shared by two throttlings parts (that is: circular groove 10 and 11), thereby can prevent formed cavitation between annular pass 10 and 11.If the pressure of pressure chamber is made as Ps, so promptly obtain P1-P2＜P _s-P ₂This kind state is an original state, and valve plug 8 moves up and can accurately control liquid stream.

The liquid of required control can be controlled according to said method.

Exemplified the operating process that valve is opened from closed condition in the above-described embodiments.Also can control liquid stream from the valve opening state throttle down according to above-mentioned same mode.

In the present embodiment, groove B is arranged on the seat surface 7a, thereby has formed pressure chamber 9 between valve plug 8 surfaces and liquid flow hole 6 surfaces.But the present invention is not limited to this kind structure.As shown in Figure 3, annular groove C can be located at valve plug 21 with valve seat contact segment 21a on, the effect that obtains is the same with the foregoing description.According to the present invention, pressure chamber 9 and pressure chamber 23 are formed between the surperficial 7a and 22a valve plug 8 and 21 and valve seat contact segment 8b and 21b and seat ring 7 and 22 separately.

According to the foregoing description, upper and lower annular pass 10 and 11 axial dimension (chock length) l1 and l2 are almost equal.But the axial dimension of following circulation road 11 can be slightly a little than the length of upper reaches path 10.

In addition, in first embodiment, liquid flows from the position of seat ring below 7 to the upper reaches.And the present invention is not limited thereto, and liquid stream can be to dirty.In addition, the pressure chamber can form with cleavage block contact segment and seat surface simultaneously.

According to above-mentioned the present invention, under very little perforate state, have the long-pending balancing gate pit of predetermined content and be formed between valve body and the contact surface of valve seat. Cannelure as the throttling part forms in the upper and lower stream both sides of balancing gate pit. Therefore the axial dimension of valve body is compared with ordinary skill and can be reduced, thereby the invention provides a kind of low shape valve gear. In addition, because in the situation of very little perforate, the cavitation that forms between valve body and valve seat contact portion and seat surface is prevented by two restriction branch, so the corrosion with valve seat contact portion and seat surface has also been prevented.

Claims (4)

1, a kind of control valve unit, this device comprises:

One has the valve seat that makes the liquid flow hole that liquid inflow entrance compartment and liquid outflow opening compartment communicate;

A valve body, described liquid flow hole is opened/closed to this valve body along the axially reciprocating of described valve seat with control,

Wherein form upper reaches and dirty throttling part, and between described upper reaches and dirty restriction branch, form pressure chamber with predetermined volume.

2, according to the device of claim 1, wherein said pressure chamber is formed at valve seat one side.

3, according to the device of claim 1, wherein said pressure chamber is formed at valve body one side of valve body and valve seat contact segment.

4, according to the device of claim 1, wherein said upper reaches and dirty throttling part are made of circular groove separately.