TWI537504B - Schaltventil - Google Patents

Description

Switching valve

The present invention relates to a switching valve including a valve seat having a longitudinal axis and a valve disc having a valve disc surface, the valve disc being movable into a flow-passing position and a closed position, the switching valve being respectively in the through-flow position and the closed position In the open and closed state, the valve disc having the valve disc surface abuts against the valve seat with its contact area in the closed position, wherein the valve disc has a modulus of elasticity of at least 1000 N/mm ² .

Such a switching valve can be used as an overpressure valve or a negative pressure valve. An overpressure valve will always be described below as an example. All statements also apply to negative pressure valves.

Such a switching valve is used to prevent the pressure in the container from exceeding a prescribed opening pressure. The valve disc abuts against the valve seat with its disc face in the closed position to close the valve. At this time, if the pressure in the container under the valve seat exceeds the opening pressure, the force exerted by the pressure on the valve disc is sufficient to cause the valve disc to enter the flow-passing position from the closed position. In this way, the valve is opened and pressure compensated. When a sufficient amount of medium flows out of the container through the valve seat, the pressure in the container below the valve seat drops again, the valve disc moves from the flow position to the closed position, and the switching valve closes. For example, the valve disc can be moved by the force of gravity acting on the valve disc. The closing force refers to the force that needs to overcome the pressure in the container under the valve seat to move the valve disc to the through-flow position. To adjust the closing force freely, the valve disc can also adopt an elastic action scheme.

If such a switching valve is embodied as a vacuum valve, the container is connected to the corresponding region above the valve disc in accordance with the aforementioned arrangement, wherein the pressure in the container must not be lower than the prescribed opening pressure. If the pressure in the container drops below the specified opening pressure, a force is applied to the valve disc to bring it from the closed position into the open position. In this way, the switching valve is opened to compensate the pressure between the container and the environment. After the pressure in the container rises and exceeds the prescribed opening pressure, the negative pressure in the container is insufficient for the valve disc to maintain the valve disc in the flow-passing position. At this time, the valve disc is closed by the closing force. position.

In order to reduce material loss, cost and environmental pollution, it is necessary to close the valve disc surface of the valve disc as close as possible to the valve seat. To this end, the prior art discloses various solutions. For example, an elastic member is provided to ensure the tightness of the valve disc face and the valve seat. The elastic sealing element can, for example, be arranged on the upper edge of the valve seat (ie, in the true sense of the contact surface facing the valve disc surface). The valve in the closed state applies a closing force to the element which deforms to seal the connection between the valve disc face and the valve seat.

As an alternative, an elastic element can also be provided in the edge region of the valve disc, the effect of which is the same as above.

No. 3,394,732 discloses a valve disc having an annular groove in the edge region of the valve disc face, on which an elastic sealing element is arranged. When the valve is closed, the seat deforms the elastomeric sealing element and presses it into the corresponding groove. In this way, the connection between the valve disc surface and the valve seat is sealed.

The disadvantage is that such valve discs are complicated in construction and costly. Further, the plastic layer (for example, FEP film) used as the elastic sealing member loses sealing property and wrinkles in the temperature range of 60 ° C to 150 ° C, and thus can be used only conditioned or not.

The prior art also discloses a valve disc which is made of metal and whose disc face is placed directly on a valve disc which is also made of metal. To seal this connection, the valve disc and seat must be extremely flat. This increases the difficulty of the manufacturing process, which is time consuming and costly. In this case, the valve seat must be ground and ground to achieve a sufficient leveling effect. The valve seat and the valve disc made by the conventional method have an unevenness of at least 10 μm.

In view of the above, it is an object of the present invention to provide a low cost switching valve that achieves sufficient sealing in a closed position of a valve disc and is easy to manufacture.

The solution for achieving this object of the present invention is a switching valve of the same type in which the valve disc is deformed in the closed position by the closing force acting on it, so that the contact area of the valve disc surface is in the closed position and in the through flow position. The contact area of the valve face forms an angle a that is not 0°.

The contact area of the valve disc, that is, the region of the valve disc that abuts against the valve seat in the closed position, is resiliently designed such that the valve disc can match the unevenness that may occur in the valve seat in the closed position Ensure the sealing of the valve seat. Among other things, the valve disc is formed from a relatively flat sheet of the surface and is currently commercially available in bulk form and made, for example, by rolling. In this way, it is not necessary to employ complex and costly processing means (for example, grinding the valve disc for up to two hours) to produce a valve disc having a desired leveling effect. The seat will be further processed and a good initial flatness must be achieved. The valve disc of the present invention can compensate for the unevenness, which can greatly reduce the materials used for the valve seat and the valve body.

The angle a is between 0.05 and 10, preferably between 0.1 and 5 . On the one hand, it ensures that the contact area of the valve disc is deformed to a sufficient extent to match the unevenness of the valve seat to ensure the sealing of the system, and on the other hand, the mechanical stress of the valve disc is prevented from being excessively increased, thereby improving the switching. The purpose of the valve life. Tests have shown that the valve seat with a diameter of 500 mm can smoothly compensate for the unevenness by tightening the valve seat by one millimeter. Such unevenness in the valve seat may result from installation errors when the valve is installed, for example, in a fuel tank, for example. The screws of the flanges fixed to the seat are not asymmetrical or unevenly screwed. The valve of the above scheme can be simply and smoothly loaded into the existing equipment.

In the closed position, the central region of the valve disc is deformed in the axial direction with reference to the longitudinal axis by a closing force, the deformation amplitude of which does not exceed 2% of the diameter of the valve seat. This degree of deformation of the central region of the valve disc allows the edge region or contact region of the valve disc surface to be angled such that the valve disc surface can match the unevenness in the valve seat and compensate for this unevenness.

According to an embodiment of the invention, the thickness of the valve disc is increased towards its center. This ensures that the edge region of the valve disc (especially the contact area of the valve disc surface) has a certain degree of elasticity and can be deformed against the unevenness in the valve seat by the closing force. At the same time, the central region of the valve disc has a degree of stability and can be secured, for example, by a guide member, whereby the valve disc can be moved from the closed position to the flow-through position. According to a particularly simple embodiment, the valve disc comprises a plurality of discs arranged concentrically and having a diameter that increases with proximity to the valve seat. In order to achieve the above stability, the disc closest to the valve disc can have a smaller diameter and it snaps into the valve seat in the closed position of the valve disc.

The valve disc preferably comprises at least one disc having a thickness of 0.5 mm.

The valve disc is preferably made of steel. It can also be made of other metals (for example, aluminum) or plastic.

If the valve disc is made of plastic, its modulus of elasticity is at least 1000 N/mm ² . The modulus of elasticity is preferably at least 1600 N/mm ² . Modulus of elasticity of the valve disk may also be made of plastic 25000N / mm ^2. If the valve disc is made of a metal material, its modulus of elasticity is, for example, between 40,000 N/mm ² and 250,000 N/mm ² . For example, the elastic modulus of the aluminum valve disc is 70,000 N/mm ² , the elastic modulus of the titanium valve disc is 105,000 N/mm ² , and the elastic modulus of the valve disc made of high-quality steel is 200,000 N/mm ² .

Regardless of the material from which the valve disc is made, the valve disc can be provided with a rim that further improves the opening characteristics of the switching valve when the opening pressure is reached. Various embodiments have disclosed a brim that is disposed on a valve disc and used to increase the opening force. The valve disc in the embodiment of the present invention may also employ such a brim.

When a certain opening pressure is reached, the valve disc will move from the closed position to the flow-passing position, the opening pressure being at least 1.5 mbar, preferably at least 2.5 mbar, and particularly preferably at least 5 mbar, the opening pressure not exceeding 1000 mbar, preferably no more than 500 mbar, and particularly preferably no more than 15 mbar.

According to a first embodiment of the invention, the valve disc comprises a first steel disc having a diameter of 675 mm and a thickness of 0.5 mm. The seat diameter is 500mm. The diameter of the first steel disk is significantly larger than the diameter of the valve disc, which helps to achieve the desired opening speed of the switching valve. Of course, the first disc only needs to be of a certain size such that the disc can abut against the valve seat in the closed position of the valve disc. a second disc having a diameter of 450 mm is disposed on the first steel disc, A third disc having a diameter of 400 mm and a fourth disc having a diameter of 350 mm. All of these discs have a thickness of 0.5 mm. Here, a steel disk is used to place the valve disk on a valve seat which is also made of metal, so that it is not necessary to add an elastic sealing element, in particular a sealing element made of plastic. Therefore, such a switching valve can be applied to a high temperature range. For example, it is applied in the range of 0 ° C to 400 ° C. If it is outside this range, special materials are used as appropriate.

For stability reasons, another disc is arranged below the first steel disc with a diameter of 350 mm and a thickness of 2 mm. All five of the above layers are concentrically arranged and together form the valve disc.

The valve disc has the smallest thickness at its edge (especially the contact area of the valve disc face) and is therefore the most elastic here. In this way, the necessary elastic deformation is ensured and the valve disc is matched to the unevenness in the valve seat.

The valve disc has an autogenous weight of about 5 kg. Tests have shown that the valve disc can smoothly compensate for the unevenness in the valve seat over the order of one millimeter. Wherein, in the closed position, the central region of the valve disc is deformed by its own weight and sags 3.5 mm, and the region of the valve disc surface that is radially outward of the valve seat relative to the longitudinal axis is lifted outward. In this case, the contact area of the valve face in the closed position forms an angle with the same area of the valve face in the flow position.

The above-mentioned autogenous weight, the resulting gravitational force and the nominal width of the valve seat (500 mm) produced an opening pressure of 2.5 mbar.

According to a second embodiment, the valve disc comprises two steel discs each having a diameter of 675 mm and a thickness of 0.5 mm. The seat width here is also 500mm. Among them, two steel plates of the same size and thickness of 0.5mm are provided. Some have a higher elasticity than a single steel disc of the same diameter and a thickness of 1 mm. Thus, this embodiment achieves greater flexibility on the edge of the valve disc, particularly on the contact area of the valve disc face with the valve seat. Discs of 450 mm, 400 mm, and 350 mm in diameter and 0.5 mm in thickness were also disposed on the two steel plates. For stability reasons, the bottom surfaces of the two larger steel discs are also arranged with another disc having a diameter of 350 mm and a thickness of 2 mm. All of these discs are arranged concentrically. In order to increase the opening pressure on the valve disc, another disc is added to the disc. In this embodiment, the disc has a diameter of 350 mm and a thickness of 2 mm. This increases the valve disc's own weight to 7.8 kg and the resulting opening pressure rises to 3.9 mbar.

In general, the opening pressure can be adjusted to 25 mbar by increasing the weight of the valve disc. If a higher opening pressure is desired, the spring can be used, for example, to increase the force.

The valve disc of the present invention achieves a leakage rate of several cubic centimeters per minute. When the valve seat has a nominal width of 500 mm and an opening pressure of 2 mbar, the test valve achieved a leak rate of 2.9 cm ³ /min.

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The lower half of Fig. 1 is a plan view of the switching valve as shown in the first embodiment of the present invention. As shown in Fig. 1, the valve disc 2 has a circular shape. A guiding member 4 is arranged in the center thereof, and the valve disc 2 is movable along the guiding member from the closed position to the through-flow position. The center of the guide member 4 is provided with a longitudinal axis L, which in these embodiments is the axis of symmetry of the switching valve, along which the valve disc 2 can be moved. The upper half of Figure 1 is the switching valve A section along the I-I line.

The valve disc 2 in the figure is in the closed position. The valve disc 2 abuts against the valve seat 8 with its bottom surface forming the valve disc surface 6. The area of the valve disc face 6 against which the valve disc 2 abuts against the valve seat 8 is the contact zone 10.

The valve disc 2 shown in Fig. 1 is composed of two steel plates each having a thickness of, for example, 0.5 mm. The center of the valve disc 2 is provided with a guide member 4 which is spirally connected thereto. As shown in FIG. 1, a nut 12 is provided correspondingly.

If the valve disc shown in Figure 1 is in the flow-passing position, the contact zone 10 of the disc face 6 does not abut against the valve seat 8. At this time, the edge region of the valve disc 2 is suspended downward by the weight of the valve disc. In particular, the contact region 10 of the valve disc surface 6 is suspended downward by the force of gravity. In this case, the contact zone 10 can, for example, be located 3.5 mm below the central region of the valve disc face 6, depending on the elasticity of the valve disc 2.

However, in Fig. 1, the valve disc 2 is in the closed position, and the central portion of the valve disc 2 hangs under the weight of the valve disc and the weight of the guide member 4. The edge region of the valve disc 2 is now bent upwards. In this case, the valve disc face 6 forms an angle a with its contact zone 10 in the flow-through position. Through this deformation, the valve face 6 of the valve disc 2 matches the unevenness in the valve seat 8, thereby providing a sufficient seal for the switching valve. When the nominal width of the valve seat 8 is 500 mm, the leak rate of such a valve can be lower than 94.2 cm ³ /min, specifically below 27 cm ³ /min. In this case, the opening pressure when opening the switching valve is, for example, between 1.5 mbar and 5 mbar. The opening pressure can also be increased to, for example, 15 mbar or 25 mbar.

If the pressure in the valve seat 8 below the valve disc 2 exceeds the prescribed opening pressure, Then, the valve disc 2 is pressed upward by the guide member 4, and the switching valve is opened. The opening pressure can be adjusted through the weight of the valve disc 2 and the guide member 4. In order to achieve the purpose of increasing the opening pressure, a simple way is to add weight to the valve disc 2 or the guide member 4.

The lower half of Fig. 2 is a plan view of the switching valve shown in another embodiment of the present invention. The center of the valve disc 2 is also provided with a guide 4 which is formed by a plurality of concentrically arranged discs 22, 24, 26. The upper half of Figure 2 is a cross-sectional view taken along line II-II.

The valve disc 2 shown in Fig. 2 is composed of three concentric discs 22, 24, 26. In Figure 2, the diameters of the disks are decreasing upwards. Each disc 22, 24, 26 is equally thick and has the same thickness between all discs. Of course, the discs 22, 24, 26 may not be equal in thickness, and the thickness between the discs may be different.

Compared with the embodiment shown in Fig. 1, this method can increase the weight of the valve disc 2 itself. The opening pressure of such a switching valve is also higher than the embodiment shown in FIG.

In the position in which the valve disc shown in Fig. 2 is located, the pressure exerted on the valve disc by the pressure in the container below the valve seat 8 is exactly equal to the closing force acting on the valve disc, which may be acting on the valve, for example. The gravity of the disk 2. If the opening pressure is required to be greater than the self-weight of the valve disc, the valve disc can be spring-loaded, for example.

Although the valve disc 2 shown in Fig. 2 abuts against the valve seat 8, the center of the valve disc does not sag. If the valve disc 2 is in the closed position, the valve disc may sag as in the embodiment shown in Figure 1, and the contact area 10 of the disc surface 6 will form an angle a with the same area of the valve disc surface 6 in the flow-through position. However, since the closing force acting on the valve disc 2 is just right by the pressure in the container below the valve seat 8, Therefore, the valve disc surface 6 is not bent.

The special arrangement of the plurality of discs 22, 24, 26 in this manner, in addition to increasing the self-weight of the valve disc 2, can also improve the stability of the central region of the valve disc 2 to improve the stability of the guide member 4.

The contact zone 10 of the valve disc 2 is also of a very thin design, where the elasticity is higher than the central area, so that the desired deformation effect can also be achieved. The valve disc shown in Fig. 2 can also be deformed in its closed position by the closing force acting on it, so that the contact area 10 of the valve disc surface 6 forms an angle a with the contact area 10 of the valve disc surface in the flow-through position.

Of course, the valve disc 2 can also be constructed from more or fewer discs 22, 24, 26. For example, four, five or six discs may be employed, which in particular may increase the self-weight and opening pressure of the switching valve. Furthermore, it is advantageous to provide another smaller but, for example, thicker disc below the largest disc 22, which helps to further stably position the guide 4 on the valve disc 2. When the valve disc 2 is in the closed position, the smaller disc disposed below the largest disc 22 snaps into the valve seat 8.

The lower half of Fig. 3 is a plan view of the switching valve shown in another embodiment of the present invention. The upper half of Figure 3 is a cross-sectional view taken along line III-III. The valve disc 2 shown in Fig. 3 is formed by a single disc 28 which, unlike the embodiment shown in Figures 1 and 2, is not of equal thickness. The central portion of the disc 28 (i.e., the region of the valve disc 2 on which the guide member 4 is disposed) has the largest thickness. This area ensures that the valve disc 2 is sufficiently stable and the thickness of the valve disc 2 is reduced towards the edge, which provides the necessary resilience for the deformation of the valve disc.

In the position where the valve disc shown in Fig. 3 is located, the capacity below the valve seat 8 The force exerted on the valve disc by the pressure within the valve is also exactly equal to the closing force acting on the valve disc, so that the disc face 6 (specifically) does not bend within the contact zone 10. If the valve disc 2 is in the closed position, the valve disc will also sag, and the contact area 10 of the disc surface 6 will form an angle with the contact area 10 of the valve disc surface 6 in the flow-through position.

The lower half of Fig. 4 is a plan view of the switching valve shown in another embodiment of the present invention. The upper half of Figure 4 is a cross-sectional view taken along line IV-IV. Therein, the valve disc 2 is shown with an annular region in which an elastic element 30 is arranged. In this way, the necessary elasticity is provided for the deformation of the valve disc 2 in this region, and the contact region 10 of the valve disc 2 and the valve disc region provided with the guide member 4 are in a non-elastic stable design.

In the position in which the valve disc shown in Fig. 4 is located, the pressure from the lower acting on the valve disc is also exactly offset by the closing force, so that the valve disc surface 6 is not bent.

The lower half of Fig. 5 is a plan view of the switching valve shown in another embodiment of the present invention. The upper half of Fig. 5 is a cross-sectional view along the line V-V.

The valve disc 2 shown in Figure 5 is in its closed position. The valve disc 2 consists of a single disc which can be made, for example, of steel, other metals or plastic. Under the self-weight of the valve disc 2 and the guide member 4, the center of the valve disc 2 is drooped, and the contact portion 10 of the valve disc surface 6 is bent upward. In the flow-through position, the contact zone 10 of the valve disc face 6 is suspended downwards, as indicated by the dashed lines in FIG.

The valve disc 2 is deformed by the closing force acting thereon, so that the contact area of the valve disc surface 6 forms an angle a with the contact area 10 of the valve disc surface 6 in the flow-through position. The embodiment shown in FIG. 5 differs from that of FIG. 1 in that a sealing member 32 is added to the upper end of the valve seat 8, and the sealing member is under the pressure of the valve disc 2. Deformation occurs to seal the valve.

In accordance with a very low cost embodiment of the present invention, each of the disks 22, 24, 26 is cut from a high surface quality sheet which is helically connected in a concentric manner by threads on the guide member 4. This greatly simplifies the process of such a switching valve and minimizes costs.

Such a switching valve can be used as an overpressure valve or a negative pressure valve. Typically, the opening pressure is between 1.5 mbar and 15 mbar, for example. Higher opening pressures can also be used. If the opening pressure exceeds, for example, 25 mbar, the opening pressure is generally insufficient to increase the valve disc's own weight, and it is necessary to apply additional force to the valve disc 2 (for example, via a spring or a lever). . The embodiment in which the elastic plastic element is required to be provided in Figs. 1 to 3 is particularly suitable for use in a high temperature range. For example, if the components of the valve disc 2 and the valve seat 8 are made of high-quality steel, no problem occurs below 400 °C.

2‧‧‧ valve disc

4‧‧‧Guide

6‧‧‧ valve face

8‧‧‧ valve seat

10‧‧‧Contact area

12‧‧‧ nuts

22‧‧‧ disc

24‧‧‧ disc

26‧‧‧ disc

28‧‧‧ disc

30‧‧‧Flexible components

32‧‧‧Sealing components

L‧‧‧ vertical axis

‧‧‧‧ angle

The lower half of Figures 1 to 5 are top views of the valves shown in the various embodiments of the present invention, and the upper half is a cross-sectional view along the horizontal line in the respective lower half.

2‧‧‧ valve disc

4‧‧‧Guide

6‧‧‧ valve face

8‧‧‧ valve seat

10‧‧‧Contact area

12‧‧‧ nuts

L‧‧‧ vertical axis

Claims (10)

A switching valve includes a valve seat (8) having a longitudinal axis (L) and a valve disc (2) having a valve disc surface (6), the valve disc can enter a flow-through position and a closed position, the switching The valve is in an open state and a closed state in the flow-through position and the closed position, respectively, the valve disc (2) having the valve disc surface (6) abutting the valve with a contact zone (10) in the closed position The seat (8), wherein the valve disc has an elastic modulus of at least 1000 N/mm ² , characterized in that the valve disc ( 2 ) is in the closed position due to a closing force acting on the valve disc The deformation occurs such that the contact zone (10) of the valve disc surface (6) in the closed position forms an angle a not equal to 0° with the contact zone (10) of the valve disc surface (6) in the flow-through position. The switching valve of claim 1 is characterized in that the angle α is between 0.05° and 10°, preferably between 0.1° and 5°. A switching valve according to claim 1 or 2, characterized in that in the closed position, a central region of the valve disc (2) is in the axial direction with reference to the longitudinal axis L under the closing force Deformation occurs, the deformation amplitude of which does not exceed 2% of the diameter of the valve seat (8). A switching valve according to claim 1 or 2, characterized in that the thickness of the valve disc (2) is increased toward the center thereof. A switching valve according to claim 4, characterized in that the valve disc (2) comprises a plurality of discs (22, 24, 26) arranged concentrically with each other, the diameters of the discs being close to the valve seat ( 8) and increase. A switching valve according to claim 1 or 2, wherein the valve disc (2) comprises at least one disc (22, 24, 26) having a thickness of 0.5 mm. A switching valve according to claim 1 or 2, wherein the valve seat (8) comprises a sealing member (32) which abuts against the sealing member with its valve disc surface (6) . A switching valve according to claim 1 or 2, wherein the valve disc (2) is made of steel. The switching valve of claim 1 or 2, wherein the valve disc (2) is made of plastic. The switching valve of claim 1 or 2, wherein the valve disc (2) moves from the closed position to the flow-passing position when an opening pressure is reached, the opening pressure being at least 1.5 mbar. Preferably, it is at least 2.5 mbar, particularly preferably at least 5 mbar, and the opening pressure is not more than 1000 mbar, preferably not more than 500 mbar, and particularly preferably not more than 15 mbar.