Pressure compensation irrigation emitter based on double-shot molding production

Abstract

The invention relates to a pressure compensation irrigation emitter based on double-shot molding production, which is characterized in that the pressure compensation irrigation emitter comprises a base and the elastic membrane (2-7) which are integrally formed, a water inlet (2-1) is formed in the lower part of the base, the water inlet (2-1) is communicated with one end of a bent flow channel (2-4) arranged at the top of the base through a water inlet drainage groove (2-3), and the other end of the bent flow channel (2-4) is communicated with the elastic membrane (2-7) through a water outlet drainage groove (2-3). The other end of the flow channel (2-4) is communicated with a water outlet pool arranged at the top of the base, and a water outlet (1-3) is formed in the upper portion of the water outlet pool. The pressure compensation irrigation emitter is only composed of the diaphragm and the base, the elastic diaphragm is located at the water outlet part of the base, the two parts are integrally formed through the double-shot molding technology, and an injection molding-assembly production technology system for the gland, the diaphragm and the base of a traditional pressure compensation irrigation emitter is changed. In addition, the size of the irrigation emitter is reduced to be consistent with that of a non-pressure compensation sheet type irrigation emitter, a non-pressure compensation sheet type production line can be adopted, and the production cost of the pressure compensation irrigation emitter is greatly reduced.

Description

Technical Field

[0001] The invention relates to the field of drip irrigation system emitter products, in particular to a pressure compensation emitter produced based on double-color injection molding. Background Art

[0002] Drip irrigation technology is considered to be one of the important measures to alleviate water shortage and ensure my country's food security. In recent years, drip irrigation technology has achieved remarkable development achievements in my country. As the core component of the drip irrigation system, the quality of the emitter directly determines the service life of the drip irrigation system. At present, the production process of non-pressure compensation emitter products in my country is relatively complete, but the pressure compensation emitter products are relatively scarce. At the same time, the cost of foreign pressure compensation function emitters is relatively high, generally more than 1 yuan / meter. The main reason is that the production process of the pressure compensation emitter is relatively complicated. It consists of three parts: the gland, the diaphragm, and the base. All three parts need to be separately injection molded. Secondly, they are assembled by the assembly line and finally formed into pipes through the drip irrigation belt production line. Therefore, the development of new low-cost pressure compensation emitter products provides technical support for the large-scale upgrading and transformation of the drip irrigation system.

[0003] Many professional scholars have developed different types of pressure-compensating sprinkler products. For example, the Chinese invention patent (CN117291037A) discloses a pressure-compensating sprinkler and its optimization design method, which proposes a pressure-compensating sprinkler optimization design method for improving performance, and the hydraulic performance and anti-clogging performance are greatly improved. The Chinese invention patent (CN 107593373A) discloses a tube-type pressure-compensating sprinkler, which can also achieve effective pressure compensation under low-pressure conditions, ensuring the stable outflow of the sprinkler, and is more suitable for large-area and long-distance drip irrigation operations. However, at present, the pressure-compensating sprinkler is still composed of three parts: the gland, the diaphragm, and the base, which are separately injection-molded, and then assembled by manual assembly or intelligent assembly lines. The complex production process; at the same time, the thickness of the traditional pressure-compensating sprinkler (>5mm) is quite different from that of the non-pressure-compensating sprinkler (<2.6mm), and it is impossible to share a production line for production at the same time, which leads to a high cost investment for the traditional pressure-compensating sprinkler. Summary of the invention

[0004] In view of the defects existing in the prior art, the purpose of the present invention is to provide a pressure compensating sprinkler produced based on two-color injection molding. The present invention consists of only two parts, a diaphragm and a base. The diaphragm is mainly located at the water outlet part of the base. The two parts are integrated by a two-color injection molding process, which changes the injection molding-assembly production process system of the traditional pressure compensating sprinkler, which consists of a gland, a diaphragm, and a base. Due to the assembly requirements of the gland, a diaphragm, and a base of the traditional pressure compensating sprinkler, in order to ensure the pressure-bearing position and the tightness of the connection, the three parts need to have a certain thickness. In the present invention, the diaphragm and the base are bonded together by hot injection molding, and there is no need for a gland and other structures. Therefore, the volume of the pressure compensating sprinkler designed by the present invention is reduced to the same as that of a non-pressure compensating sheet-type sprinkler, and a non-pressure compensating sheet-type production line can be used, which greatly reduces the production cost of the pressure compensating sprinkler.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A pressure-compensating sprinkler, characterized in that the pressure-compensating sprinkler comprises an integrally formed base and an elastic diaphragm 2-7, wherein a water inlet 2-1 is provided at the lower portion of the base, the water inlet 2-1 is connected to one end of a curved flow channel 2-4 provided at the top of the base through a water inlet drainage groove 2-3, the other end of the flow channel 2-4 is connected to a water outlet pool 2-11 provided at the top of the base, a groove 2-6 and an auxiliary flow channel 2-10 are provided at the bottom base of the water outlet pool, a water outlet 1-3 is provided at the center position where the water outlet pool 2-11 is connected to the drip irrigation belt; the elastic diaphragm 2-7 is tightly fitted with the water outlet pool 2-11.

[0007] The connection between the diaphragm and the base of the pressure-compensating water emitter is as follows: the internal diaphragm is located at the water outlet of the base, and its overall shape is convex, and the base of the pressure-compensating water emitter is concave, which can ensure the connection between the base and the diaphragm. At the same time, the side and bottom of the diaphragm are hot-melt connected to the base to ensure the connection fixity of the diaphragm of the pressure-compensating water emitter. During the injection molding stage of the pressure-compensating water emitter, the base is first injection-molded, and then the diaphragm is injection-molded. To ensure the integrity of the diaphragm injection molding, the base and the bottom of the diaphragm are kept thinner during injection molding. During the injection molding cooling stage, when the ejector is ejected, the small thickness of the base and the diaphragm can be ejected by the ejector to ensure the mobility of the diaphragm.

[0008] On the basis of the above scheme, the elastic diaphragm 2-7 includes an integrally formed diaphragm bottom layer and a diaphragm top layer, the width of the diaphragm bottom layer is greater than or equal to the width of the diaphragm top layer; a diaphragm groove structure 2-6 is provided in the middle of the elastic diaphragm.

[0009] On the basis of the above scheme, in the diaphragm groove structure 2-6, the diaphragm groove height S1 is 0.1-2.0 mm.

[0010] On the basis of the above solution, the diaphragm groove structure 2-6 is a cylindrical groove with a diameter d1 of 0.2-4.0 mm.

[0011] On the basis of the above scheme, one side of the diaphragm groove structure 2-6 is provided with an auxiliary flow channel 2-10 connected to the diaphragm groove structure 2-6, the auxiliary flow channel width W2 is 0.1-3.0 mm, and the auxiliary flow channel length L4 is 0.1-5.0 mm.

[0012] On the basis of the above solution, in the elastic diaphragm 2-7, the bottom layer height h1 of the diaphragm is 0.2-1.2 mm.

[0013] The top height h2 of the diaphragm and the connection height h3 of the diaphragm and the water outlet base of the pressure compensation water emitter can be different: the top height h2 of the diaphragm is 0-1.0 mm, and the connection height h3 of the diaphragm and the water outlet base of the pressure compensation water emitter is 0-1.0 mm;

[0014] The bottom width L1 of the diaphragm is 3.0-6.0 mm, the connection width L2 of the diaphragm and the side is 0.2-3.0 mm, the connection width L3 of the diaphragm and the water outlet base of the pressure compensation sprinkler is 0.2-3.0 mm, and the length W1 of the diaphragm is 3.0-10.0 m;

[0015] The upper surface of the diaphragm may be in an arc shape, and the arc radius R1 is 6.0-30.0 mm.

[0016] On the basis of the above scheme, in the base of the pressure-compensating emitter, the thickness h4 of the connection between the elastic diaphragm (2-7) and the emitter base is 0.1-0.5 mm.

[0017] The width L5 of the irrigation device screening slot is 0.5-6.0mm;

[0018] The upper surface of the emitter may be in an arc shape, and the arc radius R2 is 6.0-35.0 mm.

[0019] Based on the above solution, the material of the elastic diaphragm 2-7 is thermoplastic elastomer TPE.

[0020] TPE can be well integrated with the main polyethylene material of the drip irrigation tape and the pressure compensation sprinkler base, which can avoid the uniformity of the drip irrigation tape material during the recycling and reuse of the drip irrigation tape of the sprinkler product, and can improve product performance through material modification.

[0021] Through numerical simulation, the flow index is used as the main control index to analyze the mechanical index parameters of the pressure-compensating emitter diaphragm under different flow conditions. The mechanical parameters are mainly the diaphragm elastic modulus. According to the numerical simulation results, the appropriate elastic modulus control threshold of the elastic diaphragm is 0.03-200MPa.

[0022] The pressure compensating sprinkler produced by double-color injection molding described in the present invention has the following beneficial effects:

[0023] (1) The present invention proposes a new type of pressure-compensating sprinkler, the outer dimensions of which are consistent with those of a traditional sheet-type non-pressure-compensating sprinkler. The sprinkler is mainly composed of a diaphragm and a base, which are connected by hot-melt connection and can be integrally formed by means of a two-color injection molding process, which completely changes the traditional injection molding-assembly production mode of pressure-compensating sprinklers. At the same time, due to this advantage, the thickness of the two-color injection-molded pressure-compensating sprinkler is consistent with that of a non-pressure-compensating sprinkler, and can be produced on the same production line, which can effectively reduce the manufacturing cost of the pressure-compensating sprinkler (currently, the cost of manual assembly in China is high and time-consuming, and the cost of an intelligent assembly line is more than 1.5 million yuan).

[0024] (2) In the present invention, the connection between the diaphragm and the base is mainly achieved by melting the bottom surface to connect with the side, and the base at the connection with the bottom of the diaphragm maintains a relatively small thickness, and a position for an ejector is reserved there. During the cooling and ejection process, the ejector is used to eject the base at the position connected to the diaphragm with a relatively small thickness, thereby ensuring that the diaphragm can move after integral injection molding, thereby ensuring the pressure compensation effect.

[0025] (3) The main feature of the diaphragm in the present invention is that it is convex in shape as a whole, with a groove opening in the central area of ​​the upper surface of the diaphragm, and the lower surface of the diaphragm is in direct contact with the water flow inside the drip irrigation belt. Under the action of the water flow pressure, the diaphragm deforms toward the wall of the drip irrigation belt, realizing the coordinated regulation of the water flow pressure and the cross-sectional area of ​​the outlet, which can ensure constant outflow under different pressure conditions and has a good pressure compensation effect.

[0026] (4) The present invention uses numerical simulation methods and takes the flow index as a control indicator to propose a control threshold value of the structural parameters of the key structure of the pressure compensating emitter base and the diaphragm, which can effectively ensure the pressure compensation effect of the pressure compensating emitter.

[0027] (5) The present invention proposes that the main material of the pressure compensation sprinkler diaphragm is thermoplastic elastomer (TPE), determines the key mechanical property control threshold of the diaphragm, ensures the pressure compensation effect, and realizes the compatibility of the diaphragm material with the sprinkler base material, which can ensure the influence of the diaphragm material on the sprinkler performance during the recycling and reuse of the drip irrigation tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention has the following accompanying drawings:

[0029] Figure 1 It is a new type of pressure compensation drip irrigation belt structure configuration.

[0030] Figure 2These are views of a pressure-compensating emitter, where: (a) is a three-axis side view, (b) is an AA cross-sectional view, and (c) is a bottom view.

[0031] Figure 3 It is a three-axis side view of the diaphragm of the pressure-compensating emitter, where: h1 is the height of the bottom layer of the diaphragm, h2 is the height of the top layer of the diaphragm, h3 is the connection height between the diaphragm and the outlet base table, L1 is the width of the bottom layer of the diaphragm, L2 is the connection width between the diaphragm and the side, L3 is the connection width between the diaphragm and the outlet base table, W1 is the length of the diaphragm, R1 is the arc of the upper surface of the diaphragm, S1 is the height of the diaphragm groove, d1 is the diameter of the diaphragm groove, W2 is the length of the diaphragm auxiliary flow channel, and L4 is the width of the diaphragm auxiliary flow channel.

[0032] Figure 4 It is a cross-sectional view of the pressure-compensating emitter, where: h1 is the bottom height of the diaphragm, h2 is the top height of the diaphragm, h3 is the connection height between the diaphragm and the outlet base table, h4 is the connection thickness between the diaphragm and the emitter base, L5 is the width of the emitter screening slot, R1 is the arc of the upper surface of the diaphragm, and R2 is the arc of the upper surface of the emitter.

[0033] In the figure: 1-1, pressure compensating sprinkler base, 1-2, pressure compensating sprinkler diaphragm, 1-3, water outlet, 2-1, water inlet, 2-2, water inlet grille, 2-3, water inlet drainage groove, 2-4, flow channel, 2-5, outlet base table, 2-6, diaphragm groove structure, 2-7, elastic diaphragm, 2-8, outlet base bottom surface, 2-9, ejector pin position, 2-10, auxiliary flow channel, 2-11, water outlet pool. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0035] The present invention takes the design of a pressure compensating sprinkler with a flow rate of 1.6 L / h as an example.

[0036] The new pressure compensation drip irrigation belt structure configuration is as follows Figure 1 As shown, the drip irrigation belt is mainly composed of a pressure compensation emitter base, a pressure compensation emitter diaphragm and a drip irrigation belt. The diaphragm is provided with a groove structure, which is located directly below the water outlet 1-3 to ensure that after the diaphragm is deformed, the groove corresponds to the outlet position.

[0037] The structure of the pressure compensating sprinkler is as follows: Figure 2As shown, the main movement process is that the water flow inside the drip irrigation belt contacts the bottom of the elastic diaphragm 2-7. At the same time, the water flows through the water inlet grille 2-2 at the base for preliminary filtration and then enters the water inlet diversion groove 2-3. Then the water flows through the flow channel 2-4 to the position of the water outlet base table 2-5, and at the same time contacts the top of the elastic diaphragm 2-7. At this time, due to the energy dissipation effect of the flow channel, the greater the water inlet pressure, the greater the pressure difference between the upper and lower parts of the elastic diaphragm, so that the outflow cross-sectional area between the diaphragm and the water outlet is smaller, thereby achieving the purpose of constant flow. At the same time, a diaphragm groove structure 2-6 is arranged on the upper surface of the elastic diaphragm to ensure that the elastic diaphragm will not block the water outlet under the action of large deformation of the diaphragm, resulting in the problem of no outflow when the pressure is high.

[0038] The structure of the pressure compensating sprinkler is as follows: Figure 2 As shown, the main movement process is that the water flow inside the drip irrigation belt contacts the bottom of the elastic diaphragm. At the same time, the water flows through the water inlet grille and enters the top position of the diaphragm via the flow channel. At this time, due to the energy dissipation effect of the flow channel, the greater the water inlet pressure, the greater the pressure difference between the upper and lower parts of the diaphragm, and the smaller the outflow cross-sectional area between the diaphragm and the outlet, thereby achieving the purpose of constant flow.

[0039] Taking the flow index as an indicator, the structural parameter analysis was carried out through numerical simulation. The final structural parameters of the diaphragm and base are as follows:

[0040] The main structural parameters of the pressure-compensating sprinkler diaphragm are as follows: the bottom height of the h1 diaphragm is 0.6mm, the top height of the h2 diaphragm is 0.2mm, the connection height between the h3 diaphragm and the outlet base table is 0.3mm, the bottom width of the L1 diaphragm is 5.0mm, the connection width between the L2 diaphragm and the side is controlled to be 0.3mm, the connection width between the L3 diaphragm and the outlet base table is 0.3mm, the length of the W1 diaphragm is 5.0mm, the arc radius of the upper surface of the R1 diaphragm is 16.0mm, the height of the S1 diaphragm groove is 0.3mm, the diameter of the d1 diaphragm groove is 3.0mm, the length of the W2 diaphragm auxiliary flow channel is 0.5mm, and the width of the L4 diaphragm auxiliary flow channel is 0.4mm.

[0041] The main structural parameters of the pressure-compensating sprinkler base are: h1 diaphragm bottom layer height is 0.6mm, h2 diaphragm top layer height is 0.2mm, h3 diaphragm and outlet base connection height is 0.3mm, h4 diaphragm and sprinkler base connection thickness is 0.1mm, L5 sprinkler screening slot width is 2.0mm, R1 diaphragm upper surface arc radius is 16.0mm, R2 sprinkler upper surface arc radius is 18.0mm.

[0042] The elastic diaphragm 2-7 of the pressure compensating emitter is made of thermoplastic elastomer TPE, and the appropriate elastic modulus control threshold of the elastic diaphragm is 0.8 MPa.

[0043] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A pressure compensating sprinkler, characterized in that: The pressure-compensating sprinkler comprises an integrally formed base and an elastic diaphragm (2-7), wherein a water inlet (2-1) is provided at the bottom of the base, the water inlet (2-1) is connected to one end of a curved flow channel (2-4) arranged at the top of the base through a water inlet drainage groove (2-3), the other end of the flow channel (2-4) is connected to a water outlet pool (2-11) arranged at the top of the base, a groove (2-6) and an auxiliary flow channel (2-10) are provided at the bottom of the water outlet pool, and a water outlet (1-3) is provided at the center of the connection between the water outlet pool (2-11) and the drip irrigation belt; the elastic diaphragm (2-7) is tightly fitted with the water outlet pool (2-11).

2. A pressure compensating emitter as claimed in claim 1, characterized in that: The elastic diaphragm (2-7) comprises an integrally formed diaphragm bottom layer and a diaphragm top layer, the width of the diaphragm bottom layer is greater than or equal to the width of the diaphragm top layer; a diaphragm groove structure (2-6) is provided in the middle of the elastic diaphragm.

3. A pressure compensating emitter as claimed in claim 2, characterized in that: In the diaphragm groove structure (2-6), the diaphragm groove height S1 is 0.1-2.0 mm.

4. A pressure compensating emitter as claimed in claim 3, characterized in that: The diaphragm groove structure (2-6) is a cylindrical groove, and its diameter d1 is 0.2-4.0 mm.

5. A pressure compensating emitter as claimed in claim 4, characterized in that: An auxiliary flow channel (2-10) communicating with the diaphragm groove structure (2-6) is provided on one side of the diaphragm groove structure (2-6); the auxiliary flow channel width W2 is 0.1-3.0 mm, and the auxiliary flow channel length L4 is 0.1-5.0 mm.

6. A pressure compensating emitter as claimed in claim 1, characterized in that: In the elastic diaphragm (2-7), the bottom layer height h1 of the diaphragm is 0.2-1.2 mm.

7. A pressure compensating emitter as claimed in claim 1, characterized in that: In the base of the pressure-compensating emitter, the thickness h4 of the connection between the elastic diaphragm (2-7) and the emitter base is 0.1-0.5 mm.

8. A pressure compensating emitter as claimed in claim 1, characterized in that: The material of the elastic diaphragm (2-7) is thermoplastic elastomer TPE.

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