CN111795175A - Valve stem mounting structure, diaphragm valve with the valve stem, and processing technology of the diaphragm valve - Google Patents

Abstract

The invention relates to the technical field of diaphragm valves, and specifically discloses a valve stem installation structure, a diaphragm valve with the valve stem, and a processing technology of the diaphragm valve, wherein the valve stem installation structure includes a valve stem and a buffer body, and the buffer body is located in the valve Between the stem and the valve core, the valve stem and the valve core are separated. The diaphragm valve includes a valve stem, a valve core and a buffer body, as well as a valve body, a valve cover, a diaphragm and a rubber lining, and the valve stem passes through the valve cover and is threadedly connected to the buffer body; the rubber lining is pasted on the valve body. The inner wall of the valve is placed between the valve body and the valve cover, the diaphragm is attached to the valve core and the outer surface of the pressure bowl and is placed between the valve body and the valve cover, and a medium passage is formed between the diaphragm and the rubber lining, and the valve body Using aluminum alloy material. The invention can solve the problem of easy bending of the valve stem in the existing straight-through diaphragm valve, and the diaphragm valve is light in weight and easy to install.

Description

Valve stem mounting structure, diaphragm valve with the valve stem, and processing technology of the diaphragm valve

technical field

The invention belongs to the technical field of diaphragm valves, and particularly relates to a valve stem installation structure, a diaphragm valve having the valve stem, and a processing technology of the diaphragm valve.

Background technique

Diaphragm valve is a globe valve that uses a diaphragm as an opening and closing member to close the flow channel, cut off the fluid, and separate the inner cavity of the valve body and the inner cavity of the valve cover. Diaphragm valve is a special form of shut-off valve. Its opening and closing part is a diaphragm made of soft material, which separates the inner cavity of the valve body from the inner cavity of the valve cover and the driving parts, so it is called a diaphragm valve. Its most prominent feature is that the diaphragm separates the inner cavity of the lower valve body from the inner cavity of the upper valve cover, so that the valve stem and other parts located above the diaphragm are not corroded by the medium, the packing sealing structure is omitted, and the medium leakage will not occur.

Diaphragm valves can be divided into six types according to their structural forms: house type, DC type, cut-off type, straight-through type, gate type and right-angle type; the connection form is usually flange connection; according to the driving mode, it can be divided into three types: manual, electric and pneumatic , Among them, the pneumatic drive is divided into three types: normally open, normally closed and reciprocating.

Among them, the straight-through diaphragm valve is specially used to control non-corrosive or general corrosive media. The connection structure between the valve stem and the valve core is usually directly connected. When the valve core is subjected to external force, the valve stem is prone to bending.

At present, the valve body of the straight-through diaphragm valve on the market is usually made of cast iron or cast steel, which is heavy and inconvenient to install, especially on-site high-altitude installation, which requires the help of hoisting equipment and multiple people to work at the same time to complete the valve installation work.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is: how to solve the problem that the valve stem is prone to bending in the existing straight-through diaphragm valve.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

The valve stem installation structure includes a valve stem and a buffer body, the buffer body is located between the valve stem and the valve core, and the valve stem is separated from the valve core.

Principle of the present invention: The present invention improves the connection method between the valve stem and the valve core. From the existing direct connection structure, it is improved to add a buffer body between the valve stem and the valve core, thereby increasing the movement space of the valve stem and avoiding the Because the valve core is forced to cause the valve stem to bend, the safety of the valve is improved.

Further, the valve stem is sequentially formed by a screw rod segment, a cylinder, an optical axis segment and a cone that are coaxially arranged to form a whole, the screw rod segment is threadedly connected with the buffer body, and the diameter of the cylinder is larger than the diameter of the optical axis segment. diameter, the top of the cone is fixed with a bolt.

This is one of the structures of the valve stem. When the valve stem is installed, the cone of the valve stem passes through the square hole on the handwheel, and is tightened on the bolt on the top of the cone through a nut to realize the connection between the cone and the handwheel. Fixed, that is, to realize the connection and fixation between the valve stem and the handwheel.

Further, the valve stem is sequentially formed by a screw rod segment, a cylinder, an optical axis segment and a cone that are coaxially arranged to form a whole, the screw rod segment is threadedly connected with the buffer body, and the diameter of the cylinder is larger than the diameter of the optical axis segment. diameter, the top of the cone is provided with a threaded hole.

This is another structure of the valve stem. When the valve stem is installed, the cone of the valve stem passes through the square hole on the handwheel, and is screwed into the top of the cone to realize the connection and fixation between the cone and the handwheel, that is, the valve is realized. The connection between the lever and the handwheel is fixed.

The present invention also provides a diaphragm valve, comprising the valve stem, the valve core and the buffer body, as well as a valve body, a valve cover, a diaphragm and a rubber lining, and the valve stem is threadedly connected to the buffer body through the valve cover; The rubber lining is pasted on the inner wall of the valve body and placed between the valve body and the valve cover, the diaphragm is pasted on the valve core and the outer surface of the pressure bowl and placed between the valve body and the valve cover, the diaphragm and the rubber lining are A medium path is formed between them.

Further, the valve body is made of aluminum alloy material.

At present, the valve body of the straight-through diaphragm valve on the market usually adopts cast iron or steel casting. The present invention adopts aluminum alloy as the material of the valve body. The advantages are:

(1) Light weight: At present, the valve body of the straight-through diaphragm valve on the market is usually made of cast iron or steel casting, and its weight is relatively heavy. The valve body of the present invention is made of aluminum alloy, compared with the existing cast iron and cast steel. The weight of the parts is lightened, which is convenient for installation, especially on-site high-altitude installation. For example, the existing 140-pound diaphragm valve made of cast iron material is reduced to about 50 pounds after using aluminum alloy material. When installing a diaphragm valve on a 30-meter sulfuric acid tower, it is now Some diaphragm valves require three people to install at the same time, while the aluminum alloy diaphragm valve of the present invention can be installed by only one person and one hand, which saves labor costs and improves installation efficiency.

(2) Energy saving and environmental protection: the melting temperature required for aluminum alloys is about 700 °C, and the melting temperature required for casting cast iron or steel castings is above 1600 °C, which also consumes a lot of natural sand and natural water. And pollute the environment; and after the valve body is made of aluminum alloy, the valve body can save energy during production, and is environmentally friendly and pollution-free.

(3) One-shot molding: the existing cast iron castings have low precision, and need to be machined after molding to improve the accuracy of the product, while the aluminum alloy has high precision, and the valve body of the aluminum alloy material can be formed at one time, and almost no machining is required. The processing volume is small, which improves the product quality.

(4) The surface of the valve body is smooth and clean: After the existing cast iron valve body is formed, its surface is rough, while the valve body made of aluminum alloy material has a smooth surface and exquisite craftsmanship.

(5) Elimination of painting process: After the existing cast iron is formed, in order to prevent rust, it is usually necessary to spray paint on the surface of the valve body; and after using aluminum alloy, it can prevent rust without painting, and the painting process is omitted.

(6) The overall cost of the valve body is reduced: Although the cost of aluminum alloy is slightly higher than that of cast iron, the overall cost of producing an aluminum alloy valve body is lower than that of cast iron because the valve body does not need to be painted or machined.

Further, the grade of the aluminum alloy is ZL101A or ZL301.

Since the inner wall of the valve body of the present invention is lined with rubber, which is used for anti-corrosion, in the actual production process of the valve body, the pressure of the valve body is required to be more than 6t during the glue injection process of the rubber lining. Causes a lot of tension. The aluminum alloy with the grade of ZL101A or ZL301 has a high tensile strength to ensure that the valve body will not be exploded during the rubber-lined injection process.

In harsh working conditions, especially in highly corrosive working environments (such as phosphorus chemical industry), the valve body is required to have good corrosion resistance. The aluminum alloy with the grade of ZL101A or ZL301 has good corrosion resistance To meet the needs of harsh working conditions, it is suitable for casting various parts with large loads in corrosive media such as seawater with a working temperature below 150°C.

Further, at least two layers of polymer material adhesive layers are arranged between the rubber lining and the valve body.

The valve body is made of aluminum alloy material. The operating temperature of the valve is above 70~80℃. After long-term use, due to the large thermal shrinkage of aluminum alloy, the repeated expansion and contraction of aluminum alloy will easily lead to the weakening of the adhesive strength of the rubber lining. The rubber lining is partially peeled off, and the internal sealing performance of the valve body becomes poor, resulting in the scrapping of the entire valve. In order to solve this problem, the inventor has tried many methods to enhance the bonding strength between the rubber lining and the valve body. It is ideal. Finally, the inventor found that when multiple layers of polymer material adhesive layers are provided, each layer of polymer material adhesive layers has good fusion, and when the aluminum alloy undergoes thermal shrinkage, the rubber lining will hardly expand and contract. , which can well solve the problem that the bonding strength between the valve body and the rubber lining is weakened due to the large thermal shrinkage of the aluminum alloy, and ensures that the valve body can still have good sealing performance after a long time of use. .

Further, the outer diameter of the pressure bowl is smaller than the inner diameter of the valve cover, and a guide channel for the movement of the pressure bowl is formed inside the valve cover.

The existing pressure bowl has a simple structure and can only play a simple supporting role for the diaphragm part. The outer diameter of the improved pressure bowl is slightly smaller than the inner diameter of the valve cover, which gives the pressure bowl guidance and improves the stability of the valve core during operation. It can protect the valve stem from bending due to external force, thereby improving the operating safety of the valve.

The present invention also provides a processing technology of the diaphragm valve, comprising the following steps:

The valve body of aluminum alloy material is formed by gravity casting as a whole, and the grade of aluminum alloy is selected as ZL101A or ZL301;

The valve body is lined with plastic as a whole, and it is molded by plastic injection.

Further, after the valve body is formed by gravity casting as a whole, at least two layers of polymer material adhesive layers are firstly arranged on the inner wall of the valve body, and then glue injection molding is performed.

Description of drawings

FIG. 1 is a schematic structural diagram of Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view of FIG. 1 .

FIG. 3 is a structural diagram of the connection between the valve stem and the valve core in FIG. 2 .

FIG. 4 is a schematic structural diagram of the valve stem in FIG. 2 .

FIG. 5 is an enlarged view of the bonding structure between the valve body and the rubber lining in FIG. 2 .

6 is a schematic structural diagram of a valve stem in Embodiment 2 of the present invention.

FIG. 7 is a top view of FIG. 6 .

Among them, valve body 1, inlet 101, outlet 102, valve cover 2, handwheel 3, valve stem 4, screw segment 41, cylinder 42, optical shaft segment 43, cone 44, bolt 440, threaded hole 441, Dust cover 5, valve core 6, diaphragm 7, rubber lining 8, pressure bowl 9, buffer body 10, polymer material adhesive layer 11.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Example 1

As shown in Figures 1 and 2, the diaphragm valve of the present invention includes a valve body 1, a valve cover 2, a valve stem 4, a valve core 6 and a handwheel 3, the valve body 1 is provided with an inlet 101 and an outlet 102, and the inlet 101 and The outlet 102 is provided with a flange for connecting the pipeline, the valve body 1 and the valve cover 2 are connected by flange, the top of the valve stem 4 is connected to the handwheel 3, and the valve stem 4 passes through the valve cover 2 to connect to the valve core 6.

The structure of the valve stem 4 is shown in FIG. 4 . The valve stem 4 is composed of a screw rod segment 41 , a cylinder 42 , an optical axis segment 43 and a cone 44 arranged coaxially to form a whole. The diameter of the cylinder 42 is larger than that of the optical axis segment 43 diameter, the top of the cone 44 is fixed with M10 bolts 440.

The connection structure between the valve rod 4 and the handwheel 3 is specifically: the cone 44 of the valve rod 4 passes through the square hole opened on the handwheel 3, and is tightened on the M10 bolt 440 on the top of the cone 44 through a nut to realize the cone The connection between 44 and the handwheel 3 is fixed, that is, the connection between the valve stem 4 and the handwheel 3 is realized.

The connection structure between the valve stem 4 and the top of the valve cover 2 is specifically: the optical axis section 43 of the valve stem 4 passes through the top of the valve cover 2, the optical axis section 43 of the valve stem 4 is sleeved with a fixing ring, and the bottom of the fixing ring abuts On the top of the valve cover 2, a circular hole is formed in the fixing ring corresponding to the optical axis section 43 of the valve stem 4, and a cylindrical pin is passed through the circular hole. In order to realize the dustproof effect inside the valve cover 2, there is a dustproof cover 5 on the outer cover of the fixing ring.

As shown in FIG. 3 , the connection structure between the valve stem 4 and the valve core 6 is specifically: a cavity is provided on the top of the valve core 6 , a buffer body 10 is clamped in the cavity, and the buffer body 10 is threadedly sleeved on the valve stem 4 on the screw segment 41.

A pressure bowl 9 is also fixed on the top of the valve core 6 to support the diaphragm 7. The outer diameter of the pressure bowl 9 is smaller than the inner diameter of the valve cover 2, and the inside of the valve cover 2 forms a guide channel for the movement of the pressure bowl 9. The stability of the valve core 6 during operation is improved, and the valve stem 4 can also be protected from being bent due to external force, thereby improving the operation safety of the valve.

The inner surface of the valve body 1 is provided with a rubber lining 8 for anti-corrosion. The rubber lining 8 extends to the flanges at the inlet 101 and the outlet 102 of the valve body 1, and the rubber lining 8 extends to the valve body 1 and the valve cover 2. connected flange.

The outer surface of the valve core 6 is provided with a diaphragm 7, the diaphragm 7 is close to the bottom of the pressure bowl 9, and extends from both sides of the bottom of the pressure bowl 9 to the flange connection between the valve cover 2 and the valve body 1, and the pressure bowl 9 plays a role in the diaphragm 7. role of support.

In the present invention, the valve stem 4 is a cast steel part to ensure the strength of the valve stem 4 to avoid its bending, and the diaphragm 7 and the rubber lining 8 are made of rubber. Other parts of the diaphragm valve (such as valve body 1, valve cover 2, pressure bowl 9, handwheel 3, etc.) are made of aluminum alloy to reduce the overall weight of the diaphragm valve.

5, in order to enhance the bonding strength between the rubber lining 8 and the valve body 1 and between the diaphragm 7 and the valve core 6, between the rubber lining 8 and the valve body 1, between the diaphragm 7 and the valve core 6 Both are provided with two layers of polymer material adhesive layers 11, the polymer material adhesive layer 11 includes an adhesive layer A and an adhesive layer B, the adhesive layer A is a layer close to the rubber lining 8, and the adhesive layer B is close to the One layer of the valve body 1 (or the adhesive layer A is the layer close to the diaphragm 7, and the adhesive layer B is the layer close to the valve core 6), in the use environment above 100 ℃, the adhesive layer A and the adhesive layer The material ductility of layer B is different, and the ductility of adhesive layer A is greater than that of adhesive layer B.

Since the valve body 1 of the present invention is made of aluminum alloy material, the service temperature of the valve is above 70-80 °C. After long-term use, due to the large thermal shrinkage of the aluminum alloy, under the repeated expansion and contraction of the aluminum alloy, it is easy to cause the rubber lining 8 The bonding strength is weakened, the rubber lining 8 is partially peeled off, and the internal sealing performance of the valve body 1 is deteriorated, resulting in the scrapping of the entire valve. In the present invention, multiple layers of polymer material adhesive layers 11 are provided, and each layer of polymer material adhesive layers 11 has good fusion. When the aluminum alloy undergoes thermal shrinkage, the rubber lining 8 hardly expands and contracts, and it can be easily It solves the problem that the bonding strength between the valve body 1 and the rubber lining 8 is weakened due to the high thermal shrinkage of the aluminum alloy, and ensures that the valve body 1 can still have good sealing performance after the valve is used for a long time. .

The processing technology of the diaphragm valve includes the following steps:

S1. The valve body 1 made of aluminum alloy material is formed by gravity casting as a whole.

S2. After the entire valve body 1 is formed by gravity casting, at least two layers of polymer material adhesive layers 11 are arranged on the inner wall of the valve body 1 .

S3. The valve body 1 is lined with rubber 8 as a whole by injection molding.

The corrosion resistance test and tensile test of the valve body 1 were carried out respectively by taking different grades of aluminum alloys.

The anti-corrosion test is used to detect the anti-corrosion performance of the valve body 1. It is used in an acid environment for 2 months, and the surface of the valve body 1 is visually inspected for corrosion.

The tensile test is used to detect the tensile resistance of the valve body 1. After the valve body 1 is cast and formed, during the injection process of the rubber lining 8, observe whether the valve body 1 is exploded (whether the valve body 1 has cracks) .

The test results are shown in Table 1:

Table 1 Anti-corrosion test and tensile test of valve body

Material Corrosion resistance Tensile resistance ZL101A Aluminum Alloy No corrosion on the surface The valve body is not exploded ZL301 aluminum alloy No corrosion on the surface The valve body is not exploded ZL104 aluminum alloy Loose surface and obvious corrosion phenomenon The valve body is blown up ZL101 Aluminum Alloy Loose surface and obvious corrosion phenomenon The valve body is blown up

It can be seen from the above table that when the aluminum alloy grade is ZL104 or ZL101, the surface of the valve body 1 produced has obvious corrosion phenomenon, indicating that the corrosion resistance of the valve body 1 is not good, and the rubber lining 8 is in the process of glue injection. The phenomenon that the valve body 1 is blown up indicates that the tensile strength of the valve body 1 is not enough; when the aluminum alloy grade is ZL101A, the surface of the produced valve body 1 does not show corrosion, indicating that the valve body 1 has better corrosion resistance, and The phenomenon that the valve body 1 was not exploded during the glue injection process of the rubber lining 8 showed that the valve body 1 had better tensile performance. Therefore, it is best to choose the aluminum alloy with the grade of ZL101A or ZL301, and its corrosion resistance and tensile properties meet the requirements of valve body 1.

Embodiment 2

The difference between this embodiment and the first embodiment is that the connection between the cone 44 of the valve stem 4 and the handwheel 3 is different in this embodiment. As shown in FIG. 6 and FIG. 7 , in this embodiment, the valve stem 4 is sequentially The screw segment 41, the cylinder 42, the optical axis segment 43 and the cone 44 are coaxially arranged to form a whole. The top of the cone 44 is provided with a threaded hole 441, and the cone 44 of the valve stem 4 passes through the square hole on the handwheel 3. , the connection and fixation between the cone 44 and the handwheel 3 is realized by screwing the screw into the threaded hole 441 at the top of the cone 44 .

Embodiment 3

The difference between this embodiment and the first embodiment is that the number of layers of the polymer material adhesive layer 11 is different. In this embodiment, the number of layers of the polymer material adhesive layer 11 is three, and the three-layer polymer material adhesive layer 11 It can also play the problem of preventing the adhesive strength of the rubber lining 8 from decreasing.

The above are only the preferred embodiments of the present invention. It should be pointed out that the technical solutions made by those skilled in the art without departing from the technical solutions should be regarded as falling within the requirements of the claims. scope of protection.

Claims (10)

1. The valve rod mounting structure is characterized by comprising a valve rod and a buffer body, wherein the buffer body is positioned between the valve rod and the valve core, and the valve rod is separated from the valve core.

2. The valve rod mounting structure according to claim 1, wherein the valve rod is formed as a whole by coaxially arranging a screw rod section, a cylinder, a plain shaft section and a cone in sequence, the screw rod section is in threaded connection with the buffer body, the diameter of the cylinder is larger than that of the plain shaft section, and a bolt is fixed to the top of the cone.

3. The valve rod mounting structure according to claim 1, wherein the valve rod is formed as a whole by coaxially arranging a screw rod section, a cylinder, an optical axis section and a cone in sequence, the screw rod section is in threaded connection with the buffer body, the diameter of the cylinder is larger than that of the optical axis section, and a threaded hole is formed in the top of the cone.

4. A diaphragm valve, comprising the valve rod, valve core and buffer body of any one of claims 1-3, and further comprising a valve body, a valve cover, a diaphragm and lining rubber, wherein the valve rod is in threaded connection with the buffer body through the valve cover; the lining rubber is adhered to the inner wall of the valve body and is arranged between the valve body and the valve cover, the diaphragm is adhered to the outer surfaces of the valve core and the pressure bowl and is arranged between the valve body and the valve cover, and a medium passage is formed between the diaphragm and the lining rubber.

5. The diaphragm valve of claim 4 where the valve body is of aluminum alloy material.

6. The diaphragm valve of claim 5 where the aluminum alloy is brand ZL101A or ZL 301.

7. A diaphragm valve according to any of claims 4 to 6, wherein at least two adhesive layers of polymeric material are provided between the backing rubber and the valve body.

8. The diaphragm valve of claim 4 where the pressure bowl has an outer diameter less than the inner diameter of the valve cover, the valve cover having a guide channel formed therein for movement of the pressure bowl.

9. The processing technology of the diaphragm valve is characterized by comprising the following steps of:

the valve body of the aluminum alloy material is integrally formed by gravity casting, and the grade of the aluminum alloy is ZL101A or ZL 301;

and (5) performing integral glue injection molding on the lining glue of the valve body.

10. The processing technology of the diaphragm valve according to claim 9, wherein after the valve body is integrally gravity-cast, at least two polymer material bonding layers are firstly arranged on the inner wall of the valve body, and then glue injection molding of the lining glue is performed.

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