A plastic ball valve and a manufacturing method thereof

Abstract

The present invention discloses a plastic ball valve and a manufacturing method thereof. The plastic ball valve comprises a valve body and a valve core arranged in the valve body, and a valve core sealing ring is arranged beside the valve core; the middle part of the valve body is a valve cavity, and the two ends are connecting pipes respectively, and the inner end of the connecting pipe is provided with an annular flange, and the end surface of the annular flange is provided with a plurality of axial through holes for axially positioning the valve core sealing ring during injection molding; annular grooves are respectively provided on both sides of the inner surface of the valve cavity, corresponding to the axial through holes, and the valve core sealing ring is placed in the annular grooves. The present invention utilizes the protruding end of the front end of the movable mold core to be inserted into the axial through hole, and the valve core sealing ring is pressed against the surface of the ball part of the valve core to realize the positioning of the valve core sealing ring, thereby ensuring that the valve core sealing ring will not move during the injection molding process, so that the plastic ball valve has good sealing performance after injection molding, and solves the problems of poor sealing performance, inconvenient construction and low efficiency of the plastic ball valve.

Description

Technical Field

[0001] The present invention relates to the field of valve technology, and specifically to a plastic ball valve and a manufacturing method thereof, and a connecting pipe that can be quickly disassembled and assembled. Background Art

[0002] Small-diameter valves are widely used in water supply and drainage, heating, air conditioning and other fields. At present, the small-diameter valves on the market are mainly plastic valves and copper valves. Among them, plastic valves have the advantages of light weight, corrosion resistance, no scaling, multiple ways to connect to pipelines, long service life and low cost, and their usage is increasing. Among them, plastic ball valves are the main ones.

[0003] The processing and manufacturing of plastic ball valves mainly adopts the one-piece injection molding process, which has the advantages of simple process, high production efficiency and low cost. However, the plastic ball valves manufactured by this process generally have the following disadvantages:

[0004] (1) The sealing is not good, especially after a period of use, the leakage will become more and more serious, causing the valve to fail.

[0005] (2) The connection with the plastic pipe is inconvenient. At present, there are three main ways to connect the plastic ball valve and the plastic pipe. The first is gluing, that is, the pipe is inserted into the valve joint, and the pipe and the valve are connected by gluing; the second is hot melting, the pipe and the valve are all made of hot melting materials, and the pipe and the valve are connected by hot melting; the third is threaded connection, that is, the pipe and the valve are connected by threads. In actual use, the gluing connection method requires on-site gluing, the hot melting connection method requires electricity on-site, and the threaded connection method requires sealing tape. Therefore, the construction is inconvenient and the construction efficiency is low. Especially when the pipeline needs to be replaced, both the gluing and hot melting methods require the destruction of the pipeline before replacement, resulting in a lot of unnecessary waste.

[0006] In view of this, there is an urgent need to improve the existing plastic ball valve and its manufacturing method to improve the sealing performance, extend the service life, and facilitate the connection of plastic pipes. Summary of the invention

[0007] In view of the above defects, the technical problem to be solved by the present invention is to provide a plastic ball valve and a manufacturing method thereof, so as to solve the problems of the prior art that the plastic ball valve has poor sealing performance, inconvenient construction and low efficiency.

[0008] To this end, the plastic ball valve provided by the present invention comprises a valve body and a valve core arranged in the valve body, and further comprises:

[0009] A valve core sealing ring, arranged beside the valve core;

[0010] The middle part of the valve body is a valve cavity, and the two ends are connecting pipes. The inner end of the connecting pipe is provided with an annular flange, and the end face of the annular flange is provided with multiple axial through holes for axially positioning the valve core sealing ring during injection molding; annular grooves are provided on both sides of the inner surface of the valve cavity, corresponding to the axial through holes, and the valve core sealing ring is placed in the annular grooves.

[0011] In the above-mentioned technical solution of the plastic ball valve, preferably, the axial through hole has a draft angle inclined from outside to inside.

[0012] In the above-mentioned technical solution of the plastic ball valve, preferably, the outer end of the connecting pipe is provided with a connecting structure for quick disassembly and assembly of the pipeline, and the connecting structure for quick disassembly and assembly of the pipeline comprises:

[0013] A nut, threadedly connected to the end of the connecting pipe;

[0014] A sealing gasket, wherein the end of the connecting pipe is provided with a reamer, the outer end surface of the connecting pipe is provided with a first annular boss, the outer end of the nut has a reduced diameter portion, the inner end surface of the reduced diameter portion is provided with a second annular boss, the sealing gasket is arranged in the nut, and the two end surfaces are respectively pressed by the first annular boss and the second annular boss;

[0015] An O-type sealing ring is arranged in the expansion hole portion;

[0016] The elastic clamp ring is arranged at the inner end of the O-type sealing ring, and a plurality of elastic claws of the elastic clamp ring are respectively inclined toward the inside of the connecting pipe.

[0017] In the above-mentioned technical solution of the plastic ball valve, preferably, the inner end surface of the expansion portion is provided with a chamfer.

[0018] In the above-mentioned technical solution of the plastic ball valve, preferably, the cross-sections of the first annular boss and the second annular boss are semicircular.

[0019] In the above-mentioned technical solution of the plastic ball valve, preferably, the root of the elastic claw is recessed inward to form a hollow portion.

[0020] In the above-mentioned technical solution of the plastic ball valve, preferably, the end of the elastic claw is inclined inwardly toward the center of the connecting pipe.

[0021] In the above-mentioned technical solution of the plastic ball valve, preferably, the inclination angle of the elastic claw is matched with the chamfer.

[0022] The present invention also provides a method for manufacturing the above-mentioned plastic ball valve, comprising the following steps:

[0023] Put the integrally formed valve core into the mold, put the valve core sealing ring on the inner core shaft of the movable mold core, and then close the mold;

[0024] The movable mold core moves toward the valve core as a whole, the inner core shaft is inserted into the valve core hole of the valve core, and the valve core sealing ring is pressed against the spherical part of the valve core through the extended end of the middle core shaft;

[0025] Injection plastic material is injected to form the valve body. After the molding is cooled, the movable mold core is first moved outward to demould, and then the mold is opened to take out the plastic ball valve.

[0026] In the above method and technical scheme, preferably, the movable mold core is composed of an inner core shaft and an outer core shaft which are coaxially nested, wherein the outer core shaft is provided with a plurality of core shaft holes along the circumferential direction, a plurality of intermediate core shafts are inserted in the core shaft holes, the intermediate core shafts are matched with the axial through holes one by one, the front end of the intermediate core shaft extends out of the outer core shaft to form an extended end, and the depth of the extended end is the same as the thickness of the annular flange.

[0027] It can be known from the above technical scheme that the plastic ball valve and its manufacturing method provided by the present invention have a valve cavity in the middle of the valve body, and connecting pipes at both ends. The inner end of the connecting pipe is provided with an annular flange, and the end face of the annular flange is provided with multiple axial through holes; annular grooves are provided on both sides of the inner surface of the valve cavity, corresponding to the axial through holes, and the valve core sealing ring is placed in the annular grooves. The axial through holes are used to axially position the valve core sealing ring during injection molding. The problems of poor sealing, inconvenient construction and low efficiency of existing plastic ball valves are solved. Compared with the prior art, the present invention has the following beneficial effects:

[0028] First, the extended end of the front end of the movable mold core is inserted into the axial through hole to press the valve core sealing ring onto the surface of the spherical part of the valve core to achieve the positioning of the valve core sealing ring, thereby ensuring that the valve core sealing ring will not move during the injection molding process, so that the plastic ball valve has good sealing performance after injection molding.

[0029] Secondly, the first annular boss on the end surface of the connecting pipe and the second annular boss on the locking surface of the nut can be pressed into the plane of the sealing gasket after the nut is tightened, thereby further improving the reliability of the seal.

[0030] Third, the elastic clamp is made of elastic material. When the elastic clamp is not under force, the inner diameter of the elastic claw is larger than the outer diameter of the connected pipe, and the connected pipe can be freely plugged in and out. After the external pipe is inserted into place, the nut is tightened. The elastic clamp moves inward under pressure. Under the action of chamfering, the elastic claw moves toward the center of the pipe and pierces the connected pipe. Therefore, the elastic claw can prevent the connected pipe from being pulled out. When the connected pipe needs to be removed, loosen the nut, the elastic claw rebounds, loosen the external pipe, and pull it out, realizing quick disassembly and assembly.

[0031] Fourth, the external pipeline can be completed by manual operation on site, without the need for glue or electricity, and the operation is convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces and describes the drawings required for use in the embodiments of the present invention or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A cross-sectional view of a plastic ball valve provided by the present invention;

[0034] Figure 2 for Figure 1 A magnified view of part A in FIG.

[0035] Figure 3 is a cross-sectional view of the valve body in the present invention;

[0036] Figure 4 for Figure 3 A magnified view of part B in FIG.

[0037] Figure 5 is a cross-sectional view of the nut in the present invention;

[0038] Figure 6 is a schematic diagram of the elastic clamp ring in the present invention;

[0039] Figure 7 It is a schematic diagram of the arrangement of the axial through holes in the present invention;

[0040] Figure 8 is a cross-sectional view of the movable mold core in the present invention;

[0041] Fig. 9 A schematic diagram of step 1 of the method for manufacturing a plastic ball valve provided by the present invention;

[0042] Fig.10 Schematic diagram of step 2 of the method for manufacturing a plastic ball valve provided by the present invention

[0043] Fig.11 This is a schematic diagram of step three of the method for manufacturing a plastic ball valve provided by the present invention.

[0044] Figure 1-Figure 11 In the figure, the corresponding relationship of the parts is as follows:

[0045] Valve body 100, valve core 200;

[0046] Valve chamber 101, connecting pipe 102, annular flange 103, axial through hole 104, annular groove 105;

[0047] Nut 20, sealing gasket 30, joint sealing ring 40, elastic clamp ring 50, valve core sealing ring 60;

[0048] Expansion hole portion 11, first annular boss 12, chamfer 13;

[0049] Locking portion 21, second annular boss 22;

[0050] The collar body 51, the elastic claw 52, ​​and the hollow portion 53;

[0051] Inner core shaft 301 , middle core shaft 302 , outer core shaft 303 , and protruding end 304 . DETAILED DESCRIPTION

[0052] The following will be combined with the accompanying drawings of the embodiments of the present invention to clearly and completely describe the technical solutions of the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0053] The implementation principle of the present invention is: a plurality of axial through holes are respectively provided at the positions corresponding to the valve core installation groove at both ends of the valve cavity in the middle of the valve body, and the extended end of the front end of the movable mold core is inserted into the axial through hole to press the valve core sealing ring onto the surface of the spherical part of the valve core to realize the positioning of the valve core sealing ring, thereby ensuring that the valve core sealing ring will not move during the injection molding process, so that the plastic ball valve has good sealing performance after injection molding.

[0054] In order to more clearly explain and illustrate the technical solution and implementation of the present invention, several preferred specific embodiments for implementing the technical solution of the present invention are introduced below.

[0055] It should be noted that the directional words such as "inside, outside", "front, back" and "left, right" in this article are expressed based on the product usage status. Obviously, the use of the corresponding directional words does not constitute a limitation on the protection scope of this scheme.

[0056] See also Figure 1 and Figure 3 , Figure 1 A cross-sectional view of a plastic ball valve provided by the present invention, Figure 3 A cross-sectional view of the valve body.

[0057] like Figure 1 , Figure 3As shown, the plastic ball valve provided by the present invention comprises a valve body 100 and a valve core 200 disposed in the valve body 100. The two ends of the valve body 100 are respectively a water inlet and a water outlet, and a valve stem hole is provided in the middle. The valve stem at the upper end of the valve core 200 passes through the valve stem hole, which is used to rotate the valve core 200 to achieve the connection and disconnection of the water inlet and the water outlet, and open or close the plastic ball valve.

[0058] The middle of the valve body 100 is a valve cavity 101 for accommodating the valve core 200. Both ends of the valve core 200 are provided with valve core sealing structures formed by valve core sealing rings 60. Both ends of the valve body 100 are connecting pipes 102 for connecting external pipes. The outer ends of the connecting pipes 102 are provided with connecting structures for quick disassembly and assembly of external pipes.

[0059] See also Figure 2 , Figure 4 and Figure 5 , Figure 2 for Figure 1 The enlarged view of part A in Figure 4 for Figure 3 The enlarged view of part B in Figure 5 It is a cross-sectional view of the nut in the present invention.

[0060] like Figure 2 , Figure 4 and Figure 5 As shown, the connection structure for quick disassembly and assembly of the external pipe includes a nut 20 , a sealing gasket 30 , a joint sealing ring 40 and an elastic clamping ring 50 .

[0061] The outer end of the connecting tube 102 is provided with a reamer 11, and the outer end surface of the connecting tube 102 is provided with a first annular boss 12. The outer end of the nut 20 has a locking portion 21 formed by a reduced diameter portion, and the inner end surface of the locking portion 21 is provided with a second annular boss 22. The cross-sections of the first annular boss 12 and the second annular boss 22 are preferably semicircular. The inner ring root of the first annular boss 12 is smoothly connected to the arc of the outer end surface of the connecting tube 102.

[0062] The sealing gasket 30 is arranged in the nut 20. When the nut 20 is tightened, the sealing gasket 30 is squeezed inward so that its two end faces are respectively pressed by the first annular boss 12 and the second annular boss 22; at the same time, the joint sealing ring 40 is also pressed to achieve a sealed connection effect.

[0063] like Figure 6 As shown, the elastic clamping ring 50 has an annular clamping ring body 51, and a plurality of elastic claws 52 are provided on the inner ring end surface of the clamping ring body 51. The plurality of elastic claws 52 are evenly distributed along the circumferential direction. The outer end of the elastic claw 52 is inclined inwardly toward the center of the connecting tube 102 to form a barb structure, and the root of the elastic claw 52 is recessed inwardly to form a hollow portion 53 to further improve the elasticity of the elastic claw 52.

[0064] See also Figure 2 , Figure 4 The inner end surface (step surface) of the expanded hole portion 11 of the connecting tube 102 is provided with a chamfer 13, and the inclination angle of the elastic claw 52 is adapted to the chamfer 13, so that when the elastic clamping ring 50 is squeezed by the nut 20, the elastic claw 52 moves along the chamfer 13, and under the squeezing of the chamfer 13, the inner diameter gradually becomes smaller, playing a role similar to a barb, clamping the inserted external pipe (the pipe to be connected) to prevent it from being pulled out.

[0065] The method of connecting an external pipeline using the plastic ball valve provided by the present invention is as follows:

[0066] First, insert the external pipe from one end of the nut into the connecting pipe of the plastic ball valve.

[0067] Then, tighten the nut toward the center of the plastic ball valve. After the nut is tightened, the first annular boss and the second annular boss are respectively pressed into the end surface of the sealing gasket, and a reliable seal is achieved through the combination of the sealing gasket and the joint sealing ring. At the same time, the elastic claws on the elastic clamp ring penetrate into the outer wall of the external pipe to prevent the external pipe from being pulled out.

[0068] When the external pipe needs to be removed, the nut is loosened outward, so that the elastic claws on the elastic clamping ring are relieved of force, the elastic claws rebound, the inner diameter opening increases, and the external pipe is loosened. At this time, the external pipe can be pulled out of the pipe joint to achieve quick disassembly and assembly.

[0069] See also Figure 1 , Figure 3 As shown, the valve cavity 101 in the middle of the valve body 100 is a spherical structure, which is adapted to the spherical part of the lower end of the valve core 200. The inner end of the connecting pipe 102 is provided with an annular flange 103, and the end surface of the annular flange 103 is provided with a plurality of axial through holes 104, which are circular holes uniformly arranged along the radial direction, such as Figure 7 Annular grooves 105 are respectively provided on both sides of the inner surface of the valve cavity 101, corresponding to the axial through holes 104, the annular grooves 105 are connected to the inner ends of all the axial through holes 104, the annular grooves 105 are used to place the valve core sealing ring, and the axial through holes 104 are used to axially position the valve core sealing ring 60.

[0070] The present invention also provides a method for manufacturing the above-mentioned plastic ball valve, wherein the method uses a movable mold core to mold the inner cavity of the valve body 100 and positions the valve core sealing ring 60, such as Figure 8As shown, the movable mold core is composed of an inner core shaft 301 and an outer core shaft 303 which are coaxially nested, wherein the outer core shaft 303 is provided with a plurality of core shaft holes along the circumferential direction, and a plurality of intermediate core shafts 302 are inserted in the core shaft holes, and the intermediate core shafts 302 are matched with the axial through holes 104 one by one, and the front end of the intermediate core shaft 302 extends out of the outer core shaft 303 to form an extended end 304, and the depth of the extended end 304 is the same as the thickness of the annular flange 103, so that the intermediate core shaft 302 can pass through the axial through hole 104 to be positioned against the valve core sealing ring 60. The outer shape of the valve body 100 is formed by a fixed mold and a movable mold, the valve cavity 101 is formed by the valve core 200, the annular groove 105 is formed by the valve core sealing ring 60, the axial through hole 104 is formed by the protruding end 304, the inner hole of the connecting pipe 102 and the annular flange 103 are formed by the inner core shaft 301, and the expansion hole portion 11, the first annular boss 12 and the chamfer 13 are formed by the outer core shaft 303.

[0071] Specifically, the manufacturing method of the plastic ball valve provided by the present invention comprises the following steps:

[0072] Step 1: If Fig. 9 As shown, the integrally formed valve core 200 is placed in a mold (not shown in the figure), the valve core sealing ring 60 is sleeved on the inner core shaft 301 of the movable mold core, and then the mold is closed.

[0073] Step 2: If Fig.10 As shown, the movable mold core moves toward the valve core 200 as a whole, the inner core shaft 301 is inserted into the valve core hole of the valve core 200, and the valve core sealing ring 60 is pressed against the spherical part of the valve core 200 through the extended end 304 of the middle core shaft.

[0074] Step 3: If Fig.11 As shown, the injection molding material is injected to form the valve body. After the molding is cooled, the movable mold core is first moved outward to demould, and then the mold is opened to take out the plastic ball valve.

[0075] The solution provided by the present invention can be applied to a two-way valve, and can also be applied to a three-way valve.

[0076] Based on the description of the above specific embodiments, the plastic ball valve and the manufacturing method thereof provided by the present invention have the following advantages compared with the prior art:

[0077] First, the extended end of the front end of the movable mold core is inserted into the axial through hole to press the valve core sealing ring onto the surface of the spherical part of the valve core to achieve the positioning of the valve core sealing ring, thereby ensuring that the valve core sealing ring will not move during the injection molding process, so that the plastic ball valve has good sealing performance after injection molding.

[0078] Secondly, the first annular boss on the end surface of the connecting pipe and the second annular boss on the locking surface of the nut can be pressed into the plane of the sealing gasket after the nut is tightened, thereby further improving the reliability of the seal.

[0079] Third, the elastic clamp is made of elastic material. When the elastic clamp is not under force, the inner diameter of the elastic claw is larger than the outer diameter of the connected pipe, and the connected pipe can be freely plugged in and out. After the external pipe is inserted into place, the nut is tightened. The elastic clamp moves inward under pressure. Under the action of chamfering, the elastic claw moves toward the center of the pipe and pierces the connected pipe. Therefore, the elastic claw can prevent the connected pipe from being pulled out. When the connected pipe needs to be removed, loosen the nut, the elastic claw rebounds, loosen the external pipe, and pull it out, realizing quick disassembly and assembly.

[0080] Fourth, the external pipeline can be completed by manual operation on site, without the need for glue or electricity, and the operation is convenient and quick.

[0081] Finally, it should be noted that the terms "comprises", "includes" or any other variants thereof as used herein are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0082] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone should be aware that any structural changes made under the inspiration of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention.

Claims

1. A plastic ball valve, comprising a valve body and a valve core arranged in the valve body, characterized in that: Also includes: A valve core sealing ring, arranged beside the valve core; The middle part of the valve body is a valve cavity, and the two ends are connecting pipes, the inner end of the connecting pipe is provided with an annular flange, and the end surface of the annular flange is provided with a plurality of axial through holes; the inner surface of the valve cavity is provided with annular grooves on both sides, corresponding to the axial through holes, the valve core sealing ring is placed in the annular grooves, and the axial through holes are used to axially position the valve core sealing ring during injection molding; The outer end of the connecting pipe is provided with a connecting structure for quick disassembly and assembly of the pipeline, and the connecting structure for quick disassembly and assembly of the pipeline comprises: A nut, threadedly connected to the end of the connecting pipe; A sealing gasket, wherein the end of the connecting pipe is provided with a reamer, the outer end surface of the connecting pipe is provided with a first annular boss, the outer end of the nut has a reduced diameter portion, the inner end surface of the reduced diameter portion is provided with a second annular boss, the sealing gasket is arranged in the nut, and the two end surfaces are respectively pressed by the first annular boss and the second annular boss; An O-type sealing ring is arranged in the expansion hole portion; An elastic clamping ring is arranged at the inner end of the O-type sealing ring, and a plurality of elastic claws of the elastic clamping ring are inclined toward the inside of the connecting pipe respectively; The axial through hole has a draft angle inclined from outside to inside.

2. The plastic ball valve according to claim 1, characterized in that: The inner end surface of the reamer portion is chamfered.

3. The plastic ball valve according to claim 1, characterized in that: The cross-sections of the first annular boss and the second annular boss are semicircular.

4. The plastic ball valve according to claim 1, characterized in that: The root of the elastic claw is recessed inward to form a hollow portion.

5. The plastic ball valve according to claim 2, characterized in that: The end of the elastic claw is inclined inwardly toward the center of the connecting pipe.

6. The plastic ball valve according to claim 5, characterized in that: The inclination angle of the elastic claw is matched with the chamfer.

7. The method for manufacturing a plastic ball valve according to claim 1, characterized in that: The following steps are involved: Put the integrally formed valve core into the mold, put the valve core sealing ring on the inner core shaft of the movable mold core, and then close the mold; The movable mold core moves toward the valve core as a whole, the inner core shaft is inserted into the valve core hole of the valve core, and the valve core sealing ring is pressed against the spherical part of the valve core through the extended end of the middle core shaft; Inject the injection material to form the valve body. After the molding is cooled, first move the movable mold core outward to demould, and then open the mold to take out the plastic ball valve; The movable mold core consists of an inner core shaft and an outer core shaft which are coaxially nested, wherein the outer core shaft is provided with a plurality of core shaft holes along the circumferential direction, a plurality of intermediate core shafts are inserted into the core shaft holes, the intermediate core shafts are matched with the axial through holes one by one, the front end of the intermediate core shaft extends out of the outer core shaft to form an extended end, and the depth of the extended end is the same as the thickness of the annular flange.

Images