CN1246588A - Lifting valve - Google Patents

Abstract

The invention relates to a poppet valve, characterized in that it has a first and a second valve seat (6, 7) on both sides of a narrow groove section (F) connected to one of the connection chambers (2). The closing part (8) cooperates with the two valve seats (6, 7). Two areas (16, 17) next to the two valve seats (6, 7) and opposite to the narrow groove section (F) are connected with another connection chamber (3). In this way, the poppet valve can pass a large amount of fluid even with a small lift.

Description

poppet valve

The invention relates to a poppet valve comprising a valve seat cooperating with a closure and a seat and element arranged between two connecting chambers.

This poppet valve is known in many types, for example the one disclosed by DE 36 15 229 A1 is exactly. In these valves, the annular valve seat surrounds an annular groove section which is completely covered by the annular closure. This results in a predetermined flow characteristic. They are suitable for all fluids, especially liquids.

The object of the present invention is to provide a poppet valve of the type described in the preamble, which has a high flow rate despite a small lift.

According to the present invention, the solution to this task is that there are first and second valve seats on both sides of the narrow groove section connected to one of the connecting chambers, a closure member cooperating with the two valve seats and a valve seat with the other connecting chamber. Two areas next to the connected two valve seats and opposite to the cross section of the narrow groove.

The high flow and low lift is possible because fluid can flow through the first and second seats, meaning both areas can pass fluid. This also means that for a given lift, the pressure drop across the poppet is relatively low. At the same time, only the section of the closure corresponding to the section of the gutter is exposed to the pressure difference, so that relatively small forces are sufficient to cause the upward displacement.

The so-called "narrow groove section" is a section in which the length of the two valve seats is a multiple of the distance between the two valve seats. The length-distance relationship is at least 5, preferably 10-80, especially 30-60. Preferably the distance is constant over the entire length of the valve seat, but it can also vary within the range of the above-mentioned length-distance relationship.

A particularly preferred narrow groove is annular in cross-section, thereby forming an inner ring seat and an outer ring seat. If the remaining external dimensions are equal, this results in doubling the area of the outflow opening.

In addition, it is recommended to use grooves to form narrow groove sections. It is also possible to use through-slits instead of grooves.

A particularly simple embodiment provides that the encapsulation has a common seal for both valve seats.

It is particularly advantageous if the first and/or second valve seat cooperates with the sealing lip. This sealing lip is more elastic than other seals. They provide a tight seal with less force and also open with less pressure differential.

With regard to the annular valve seat, it is recommended that the closure has an annular seal with a radially outwardly extending sealing lip and a radially inwardly extending sealing lip, which cooperate with the outer and inner valve seat respectively. The front ends of the two valve seats are preferably rounded to reduce flow noise.

It is also advantageous that the two valve seats are preferably stepped. When the load is low, the sealing lip bears in the closing direction on the first step, and when the load increases, the seal in the region of the sealing lip bears on the second step. As the load increases, the sealing action moves from the first step to the second step, so that the force acting on the sealing lip is limited in the upward direction.

In a preferred embodiment, the heights of the two valve seats are different, so that when the closing action is performed, one valve seat closes first and then the other valve seat closes. In this way, a curved valve characteristic curve is obtained, that is, when the lift increases, the flow rate increases, but first increases slowly and then increases rapidly.

It is particularly recommended to use poppet valves in leak detectors, in which case the closure element is loaded by the first closure spring in the counter-flow direction and the supplied flow is measured with a lift measuring device. The opening of the poppet valve is related to flow. The pressure drop is small, but the flow area that can be detected is very large.

A preferred embodiment provides that the closure member can be loaded by a second closure spring held in a rest position by a back pressure flange which can be moved by means of an adjusting device into a position in which the second closure spring is relaxed. Thanks to the second closing spring, the poppet valve can be safely closed. Since the pressure of the seal acts only on the annular surface of the closure, only a limited pressure of the second closure spring is sufficient, so only a small force is needed to move the back pressure flange.

For use in leak detectors, the closure preferably has a measuring rotor which is arranged in the auxiliary flow channel of the bypass ring groove. A speed measuring device is installed on the rotor to measure the flow. Since it can pass a large flow with a small lift, the measuring rotor can also achieve accurate results with a small flow.

In a preferred embodiment, the marker is scanned by the pulse measuring means on the rotor to detect the speed by evaluating the pulse frequency and the lift by evaluating the pulse-gap relationship, so that the speed measurement and the lift measurement can be performed in a very simple manner.

Hereinafter, the present invention will be described on the basis of preferred embodiments with reference to the accompanying drawings.

Fig. 1 passes through the longitudinal section of poppet valve of the present invention;

Fig. 2 passes through the longitudinal section of the leak detector of the present invention;

Fig. 3 Enlarged view of seat area A in Fig. 2.

The poppet valve of FIG. 1 has a housing 1 with a connecting chamber 2 on the inlet side and a connecting chamber 3 on the outlet side. An insert 4 is installed between the above two cavities, and an outer valve seat 6 and an inner valve seat 7 are arranged at the upper end of the annular groove 5 connected to the connecting cavity 2 on the inlet side. The open upper end of the ring groove 5 forms a narrow groove section F. The relationship between the length of the outer valve seat 6 and the distance from the inner valve seat 7 is 35. The closure 8, which is loaded in the opening direction by the return spring 9, is guided by an additional insert 10 (not shown in the figure - translator). The rotation of the insert is used to adjust the Kv value. The closure element 8 can be displaced axially by an adjuster (not shown) by means of pins 11 protruding through the seal. The regulator is, for example, a thermal switch that closes the valve when the outdoor temperature rises.

There is an annular sealing member 13 on the closure member 8, on which a radially outwardly extending sealing lip 14 cooperates with the outer valve seat 6, and a radially inwardly extending sealing lip 15 cooperates with the inner valve seat 7. The end faces of the two valve seats 6 and 7 are rounded. Secondly, the area 16 outside the outer valve seat 6 and the area 17 located inside the inner valve seat 7 are connected to the connecting chamber 3 on the outlet side via a through-ditch 18 .

As shown by the arrow 19, the fluid flows through the ring groove 5 and is divided into two streams before the opened valve: one stream enters the area 16 through the gap formed by the outer valve seat 6 and its attached sealing lip 14, and then enters the outlet side connection Cavity 3. The other stream passes through the gap formed by the inner valve seat 7 and its associated sealing lip 15 , through the region 17 and the hole 18 into the outlet-side connecting chamber 3 . Therefore, although the lift is small, it is enough to allow a large flow to pass. Since the inlet pressure acts only on the closure 8 in the ring groove 5, ie the surface area of the groove section F, the force required by the regulator to move the closure is correspondingly small.

Generally, the annular seal 13 includes rubber and an elastic plastic, so the sealing lips 14 and 15 made of it are soft and pliable, and because they cooperate well with the valve seats 6, 7, they are closed firmly with little force.

Corresponding parts of the leak detectors shown in Figures 2 and 3 are indicated by reference numerals with 100 added.

First, the length-distance relationship of the groove face F is about 45, so the allowable lift is small and the flow rate is large.

As can be seen from FIG. 3 , the heights of the inner valve seat 107 and the outer valve seat 106 are different, so the closing movement will make the valve seat 107 engage with the sealing lip 115 first, and then the valve seat 106 and the sealing lip 114 engage. This results in a curved valve characteristic curve, i.e. when the lift movement begins, only one flow area - the area between the valve seat 106 and the sealing lip 114 acts together, while the second between the valve seat 107 and the sealing lip 115 The area will not be opened until later.

The outer valve seat 106 and the inner threshold seat 107 are made into two steps. The first steps 120 , 121 are formed by annular ribs, and the second steps 122 , 123 are formed by the outer edge of the annular groove 105 . The sealing lips 114 , 115 cooperate with the first steps 120 , 121 and the areas of the seal 113 adjoining the lips cooperate with the second steps 122 , 123 .

During normal operation, the closure element 108 is loaded by a relatively soft closure spring 124, so that the closure element 108 acquires a flow-dependent lift. In conjunction with the lift measuring device described below, the poppet valve acts as a flow meter.

A stiffer closure spring 125 is normally out of engagement with the closure member 108 due to back pressure on the flange 126 . The back pressure flange 126 is provided by an insert 127 which can be adjusted via a pin 129 by means of an adjuster. The regulator can be, for example, an electric motor, but it can also be operated manually. When pin 129 and insert 127 move up, just impel closure spring 125 action, so poppet valve is closed under the effect of two closure springs 124 and 125, and this just makes step 120,121 and 122,123 play a sealing role. In this case, the poppet valve acts as a blocking device.

Mounted in the seal 108 is a measuring rotor 130 , which is supplied with flow from the inlet-side connecting chamber 102 . It flows out to the connection chamber 103 on the outlet side through the hole 131 and the groove 132 . The hole 131, the measuring rotor 130 and the groove 132 form an auxiliary flow channel, which is a bypass of the annular groove 105 and also a bypass of the lifting threshold. Measuring the speed of the measuring rotor 130 enables recording of small flow rates.

The electro-optic pulse measuring device 133 , which interferes with a light beam by a blade-shaped marker 134 on the measuring rotor 130 , generates a series of pulses which are sent to an evaluation circuit 136 via an inlet 135 . Pulse frequency is a measure of the rotor speed. The pulse-pause relationship is a measure of closure lift. In this way, with the thickness of the blades constant, the distance between adjacent blades and the lift vary in time. The pulse measuring device 133 and the evaluation circuit 136 are combined to form a lift measuring device and a speed measuring device.

This gives the following operating mode of the leak detector, which is to measure a small flow with the measuring rotor 130 when the poppet valve is closed. The greater flow rate is determined with the lifting of the closure 108 plus the flow through the measuring rotor 130 . If a different criterion is used, as long as the regulator 128 is operated, the harder closing spring 125 acts to close the poppet valve, and the evaluation circuit is used to determine the amount of leakage, whether it is a small leak or a large leak. At the same time, when the hole 131 is closed by the cover 137 on the insert 127, the auxiliary channel can be closed.

Claims (13)

1. Poppet valve with a valve seat cooperating with a closure and seat and element arranged between two connecting chambers, characterized in that: in the narrow groove connected to one of the connecting chambers (2; 102) The two sides of the section (F) are respectively made with first and second valve seats (6, 7; 106, 107); the closure (8; 108) cooperates with the two valve seats (6, 7; 106, 107) ; The two areas (16, 17; 116, 117) located close to the sides of the two valve seats (6, 7; 106, 107) and opposite to the cross-sectional direction of the narrow groove communicate with another connecting cavity (3, 103). 2. Poppet valve according to claim 1, characterized in that the narrow groove section (F) is annular, thus resulting in an outer ring seat and an inner ring seat (6, 7; 106, 107). 3. Poppet valve according to claim 1 or 2, characterized in that the narrow groove section (F) is formed by a groove (5; 105). 4. Poppet valve according to one of claims 1 to 3, characterized in that the closing part (8; 108) has a common sealing part (13; 113) for both valve seats (6, 7; 106, 107). 5. Poppet valve according to one of claims 1 to 4, characterized in that the first and/or second valve seat (6, 7; 106, 107) cooperates with the sealing lip (14, 15; 114, 115). 6. A riser according to any one of claims 2 to 5, characterized in that the closure (8; 108) has radially outwardly extending valve seats (6, 7; 106, 107) cooperating with the outer valve seat and the inner valve seat (6, 7; 106, 107) respectively Ring seal (13; 113) of sealing lip (14; 114) and radially inwardly extending sealing lip (15; 115). 7. Poppet valve according to one of claims 1 to 6, characterized in that the front edges of the two valve seats (6, 7; 106, 107) are rounded. 8. The poppet valve according to one of claims 1 to 7, characterized in that the two valve seats (16, 17) are stepped so that the sealing lip (114, 115) is supported on the first side in the closing direction when the load is small. Up the steps (120, 121). In the case of high loads, however, the seal (113) in the region of the sealing lip rests on the second step (122, 123). 9. According to one of claims 1 to 8, the poppet valve is characterized in that the heights of the two valve seats (106, 107) are different, so that during the closing action, one valve seat (107) is closed first, and then the other valve seat (106) is closed. 10. Poppet valve according to one of claims 1 to 9, characterized in that the poppet valve is used on a leak detector, wherein the closure (108) is loaded against the direction of flow by a first closure spring (124), and is provided with A lift measuring device that measures flow. 11. According to one of claims 1 to 10, the poppet valve is characterized in that the closure (108) is loaded by a second closure spring (125) held in the rest position by the back pressure flange (126), and at the same time, The back pressure flange (126) can be moved to the position of relaxing the second closing spring (125) by means of the regulator (128). 12. Poppet valve according to one of claims 1 to 11, characterized in that the closure (108) is equipped with a measuring rotor (130) located in the auxiliary channel of the bypass ring groove (105), the rotor is equipped with a measuring flow Speed measuring device. 13. Poppet valve according to claims 10 and 12, characterized in that the scanning marker (134) of the pulse measuring device (133) on the measuring rotor (130) detects the speed by evaluating the pulse frequency and by evaluating the pulse-interval relationship Check lift.

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