Dispensing assembly and application system including same

Abstract

Dispensing assembly (16) and application system. The dispensing assembly includes a positive displacement cavity pump including a flow channel plate (6) having flow channels (61, 62, 63), a nozzle plate (1) having flow channels (11), a gear stationary plate (7) mounted between the flow channel plate and the nozzle plate, and a gear set (8) disposed within an opening (71) in the stationary plate. The gear set has a fluid inlet (85) and a fluid outlet (86) on a side of the gear set opposite the fluid inlet. The fluid inlet is in fluid communication with the flow channels in the flow channel plate, and the fluid outlet is in fluid communication with the flow channels in the nozzle plate. The portion of the flow channel in the flow channel plate that is in direct fluid communication with the fluid inlet extends in a direction parallel to the axis of rotation of the gear set.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to Chinese Patent Application No. 202010806091.3, filed on August 12, 2020, which is incorporated herein by reference in its entirety.

[0002] The present invention relates to a dispensing assembly comprising a positive displacement cavity pump, the dispensing assembly including a flow path plate having flow paths for fluid flow, a nozzle plate having flow paths through the nozzle plate, a gear retaining plate mounted between the flow path plate and the nozzle plate and having an opening, and a gear set located in the opening of the gear retaining plate, the gear set having a fluid inlet and a fluid outlet on a side of the gear set opposite the fluid inlet, the fluid inlet being in fluid communication with the flow paths in the flow path plate, and the fluid outlet being in fluid communication with the flow paths in the nozzle plate.

[0003] The present invention also relates to an application system that includes the dispensing assembly. [Background technology]

[0004] Hot melt adhesives are widely used in a variety of applications. Some applications require relatively high adhesive strength, and polyurethane reactive hot melt adhesives have been used due to their relatively high adhesive strength. However, other properties of these adhesives present various manufacturing challenges. For example, polyurethane reactive hot melt adhesives react with the atmosphere and must be melted in a sealed container. Therefore, a typical adhesive supply system for polyurethane reactive hot melt adhesives includes a sealed melting unit that supplies heated adhesive to a gear pump. The adhesive is then delivered through a heated hose to a dispensing head to maintain the desired temperature.

[0005] When polyurethane reactive hot melt adhesives are used in applications where the amount of adhesive per unit is relatively small, such as sealing computer battery packs, the residence time of the adhesive in the heated hose may exceed the adhesive's "pot life," making it impossible to dispense the correct amount of adhesive.

[0006] A variety of dedicated positive displacement cavity pump dispensers are rapidly being developed to precisely apply small amounts of hot melt adhesive to workpieces. Currently, there are many existing dispensers that have been tested for this typical application. However, when operating prior art dispensers, noticeable droplets accumulated at the tip of the nozzle can always be observed. In this regard, a programmable motor reversal function for reverse pumping has been developed in advanced control software. Nevertheless, adhesive leakage from the tip of the nozzle still seems unavoidable.

[0007] As a result, when the adhesive application is completed, adhesive ends typically form and accumulate on the surface of the workpiece, which can be unsightly and even adversely affect the quality of the product. Furthermore, maintaining the application system is typically time-consuming and labor-intensive.

[0008] It would be desirable to provide a dispensing system that is capable of accurately dispensing relatively small amounts of adhesive. It would also be desirable to provide a dispensing system that is compact, easy to maintain, and responsive. Summary of the Invention

[0009] SUMMARY OF THE INVENTION It is an object of the present invention to provide a positive displacement cavity pump (VCP) integrated coating system that eliminates the above-mentioned drawbacks of the prior art.

[0010] According to a first aspect of the present invention, there is provided a dispensing assembly comprising a positive displacement cavity pump including: a flow path plate having flow paths for fluid flow; a nozzle plate having flow paths through the nozzle plate; a gear retaining plate mounted between the flow path plate and the nozzle plate and having an opening; and a gear set located in the opening in the gear retaining plate, the gear set having a fluid inlet and a fluid outlet on a side of the gear set opposite the fluid inlet, the fluid inlet being in fluid communication with the flow paths in the flow path plate and the fluid outlet being in fluid communication with the flow paths in the nozzle plate, and a portion of the flow path in the flow path plate that is in direct fluid communication with the fluid inlet extends in a direction parallel to an axis of rotation of the gear set.

[0011] As a result, the above-described positive displacement cavity pump built-in dispensing assembly can eliminate the pressure difference between the gear sets on both sides at the mounting surfaces of the gear sets and prevent the molten adhesive from passing through the meshing portions of the gear sets, thereby allowing for the dispensing of fluids such as hot melt adhesive with relatively high precision.

[0012] Preferably, the flow path plate has a first flow path, a second flow path, and a third flow path, the first flow path extending in a direction parallel to the axis of the barrel assembly and receiving fluid from the barrel assembly, the second flow path fluidly communicating the first flow path with the third flow path, and the third flow path being in direct fluid communication with the fluid inlet.

[0013] This allows the above-described positive displacement cavity pump integrated dispensing assembly to facilitate machining operations and to dispense fluids such as hot melt adhesives with relatively high precision.

[0014] Preferably, the gear set includes a drive gear and a driven gear, the drive gear being rotationally driven by the drive assembly, thereby rotating the driven gear, and the addendum coefficient of the drive gear and the driven gear being greater than the clearance coefficient thereof.

[0015] This allows the gears to be specially designed to achieve very small volumes per revolution with high precision.

[0016] Preferably, the tooth addendum factor is 0.7 and the tooth clearance factor is 0.3.

[0017] This allows for optimal fluid transport performance.

[0018] Preferably, the driven gear has a gear shaft.

[0019] Preferably, one end of the gear shaft is inserted into the flow path plate and the other end is inserted into the nozzle plate.

[0020] As a result, the shaft of the driven gear is not only used to rotate the gear, but also known as the positioning pin shaft. It plays a very important role in accurately positioning the nozzle plate, gear fixing plate, and top adhesive passage plate. Fundamentally, this design is completely different from existing metering systems (usually a separate gear pump is installed).

[0021] Preferably, the flow channels in the nozzle plate are straight.

[0022] This allows for relatively low manufacturing costs, a good cutting line edge pattern without edge buildup, easy maintenance, a short spill length, and is suitable for high viscosity materials.

[0023] Preferably, the flow passages in the nozzle plate are provided with pressure controlled check valves to open and close the flow passages.

[0024] With the above configuration, the present invention can solve the problem of leakage of fluids such as hot melt adhesives at a lower cost.

[0025] Preferably, the dispensing assembly includes a control valve assembly having a needle for opening and closing a flow path within the dispensing assembly.

[0026] With the above configuration, the high performance dispensing assembly incorporating the VCP of the present invention can permanently solve the leakage problem of fluids such as hot melt adhesives.

[0027] Preferably, the control valve assembly is an integral component attached to the nozzle plate. The nozzle plate passages are linear passages that are angled relative to the rotational axis of the gear set. Alternatively, the nozzle plate passages include a first passage and a second passage, the first passage extending from the fluid outlet of the gear set and the second passage extending at an angle relative to the first passage and in fluid communication with the needle passage.

[0028] This allows for an optimized flow path design and reduces manufacturing costs.

[0029] Preferably, the control valve assembly includes a needle housing and a top cover, the top cover is attached to the needle housing to form an internal space within which one end of the needle is accommodated, the flow paths of the nozzle plate include a first flow path, a second flow path and a third flow path, the first flow path extending from a fluid outlet of the gear set, the second flow path fluidly connecting the first flow path and the third flow path, and the third flow path extending to an outlet of the nozzle plate, and the needle housing of the control valve assembly is attached to the nozzle plate, thereby allowing the other end of the needle of the control valve assembly to move in the third flow path to control the distribution of fluid from the nozzle plate.

[0030] Thus, the control valve assembly has a composite design, which allows for easy part replacement and maintenance, and effectively reduces the formation of large adhesive tails after application operations are stopped.

[0031] Preferably, the face of the flow path plate facing the gear set is formed with grooves in areas corresponding to the fluid outlets of the gear set to reduce high oil pressure trapped in the meshed gear teeth.

[0032] Preferably, a plug rod is provided that is designed to be inserted into the second flow channel of the flow channel plate to eliminate dead ends of fluid in the second flow channel, thereby eliminating dead ends of fluid and improving adhesive passage for cleaning and maintenance of the adhesive passage.

[0033] Preferably, the thickness of the gears of the gear set is the same nominal size as the thickness of the gear fixing plate.

[0034] According to a second aspect of the present invention, there is provided an application system including a barrel assembly including a barrel for containing a fluid, a dispensing assembly attached to the barrel assembly and in fluid communication with the barrel assembly, and a drive assembly for driving the dispensing assembly to dispense the fluid from the barrel assembly via the dispensing assembly.

[0035] This application system can eliminate pressure differentials between the gear sets at the mounting surfaces of the gear sets, preventing molten adhesive from passing through the meshing portions of the gear sets, thereby allowing for the dispensing of fluids such as hot melt adhesive with relatively high precision.

[0036] These and other objects and advantages of the present invention will be more fully appreciated in conjunction with the following description of the drawings, in which the same reference numerals refer to the same or similar parts in all the drawings. [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a perspective view of a VCP built-in coating system according to a first embodiment of the present invention. FIG. [Figure 2a] FIG. 2 illustrates a cross-sectional view of the drive assembly and VCP of the application system. [Figure 2] FIG. 2 is a partially enlarged cross-sectional view of the VCP of the coating system. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4]4 is a schematic cross-sectional view taken along line IV-IV of FIG. 2, showing the gear set and its fluid inlet and outlet arrangements. [Figure 5] FIG. 10 is a cross-sectional view of a drive assembly and VCP of a second embodiment of a dispensing system of the present invention, showing a pressure-controlled check valve located on a nozzle plate. [Figure 6] FIG. 2 is an enlarged view of a pressure control check valve. [Figure 7] FIG. 10 is a perspective view of a VCP-integrated coating system according to a third embodiment of the present invention, the coating system having a control valve assembly. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] 10 is a VCP-integrated coating system according to a third embodiment of the present invention, showing the arrangement of flow channels in a nozzle plate in cross section. [Figure 10] 10 is a VCP-integrated coating system according to a third embodiment of the present invention, showing the arrangement of flow channels in a nozzle plate in cross section. [Figure 11] FIG. 1 is a partial perspective view with a portion of the top channel plate removed, showing grooves in the top channel plate. DETAILED DESCRIPTION OF THE INVENTION

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding parts are designated by the same numbers and symbols, and repeated description will be omitted.

[0039] In the following description, directional terms such as "upper", "lower", "left", "right", "front", "rear" and the like (if any) are used only to describe the drawings and do not constitute substantial limitations on the present invention.

[0040] FIG. 1 is a perspective view of a VCP-integrated dispensing system according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the drive assembly and VCP of the dispensing system. The VCP-integrated dispensing system according to the present invention is used to dispense fluids. Referring to FIG. 1, the dispensing system generally includes a barrel assembly 4 and a dispensing assembly 16 coupled to the barrel assembly 4 for selectively dispensing a fluid. The dispensing system further includes a drive assembly 3 for driving the dispensing assembly 16. A barrel or syringe (not shown) for storing the fluid may be disposed in the barrel assembly 4. The fluid may be, for example, a reactive hot melt adhesive, such as, but not limited to, an adhesive containing a polyurethane resin and a two-component polymer material, or any ambient temperature or other adhesive containing a hot melt material. Hot melt materials are known to exhibit viscosity changes during the expected life of a barrel containing the hot melt material.

[0041] FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2. Referring to FIG. 3, barrel assembly 4 includes a barrel sleeve or housing 40, which may be a heated cylinder or other form, configured to receive a disposable barrel containing a fluid therein. At room temperature, the fluid may be a solid material, such as a solid adhesive. In this regard, housing 40 can be heated such that heat transfer from housing 40 to the barrel transforms the solid material or at least maintains it in a molten state. The barrel may or may not be heated prior to insertion into housing 40; if heated, the material within the barrel may already be in a molten state when the barrel is inserted into housing 40. To facilitate heating of housing 40, barrel assembly 4 can include one or more heating elements, such as a heated barrel, and one or more temperature measurement devices, such as a resistance temperature detector, that allow for control (e.g., measurement and adjustment) of the heat supplied to housing 40 in a manner known in the art. The housing 40 has a proximal end 41 and a distal end 42, with the proximal end 41 located upstream in the barrel insertion direction and the distal end 42 located downstream in the barrel insertion direction. The barrel insertion direction coincides with the longitudinal axis of the barrel assembly 4. According to requirements, the barrel may be provided with a check valve, preferably at the bottom of the barrel to prevent backflow of fluid.

[0042] Preferably, the barrel has a capacity of 30 cc or 300 cc. The barrel is inserted through an opening in the proximal end 41 of the housing 40 and received in the interior space of the housing 40. The interior space has a shape that matches the shape of the barrel, so that the barrel fits tightly inside the housing 40. A cover 43 is attached to the housing 40, specifically to the outer periphery of the proximal end 41 of the housing 40, for example, by screwing. The cover 43 allows the barrel to be coupled to the housing 40, thereby helping to accommodate the barrel in the housing 40. Specifically, the cover 43 is connected to the proximal end 41 of the housing 40 and is fixed to the housing 40 by rotating the cover 43 (e.g., a quarter turn). When the cover 43 is fixedly coupled to the housing 40, the barrel is, for example, inserted into the interior space of the housing 40 and fixed to the housing 40.

[0043] The barrel receives pressurized air from a suitable external source through the cover 43 to apply pressure to the fluid within the barrel, and the housing 40 includes a vent port 421 at its distal end 42 for venting fluid under pressure from the housing 40 to the exterior of the barrel assembly 4, specifically to the dispensing assembly 16. Specifically, the cover 43 has an openable cover passage 430 that can communicate the interior of the barrel with an external air source. The cover passage 430 receives air from the external air source, e.g., at a pressure between about 5 psi and about 10 psi. It is contemplated that a piercing element configured to penetrate the cover 43 and reach the main volume of fluid is provided. The interior of the barrel is pressurized with pressurized air to facilitate dispensing of the fluid toward the exterior of the barrel, such as the dispensing assembly 16.

[0044] The dispensing assembly 16 has the form of a positive displacement cavity pump and is coupled to the barrel assembly 4 in a manner described below so as to dispense a precise amount of fluid from the barrel assembly 4. As shown in FIGS. 1-3 , the dispensing assembly 16 includes a channel plate 6 at the top, a nozzle plate 1 at the bottom, a gear station plate 7 connected between the channel plate 6 and the nozzle plate 1, and a gear set 8 disposed on the gear station plate 7. The channel plate 6, the nozzle plate 1, the gear station plate 7, and the gear set 8 together constitute a positive displacement cavity pump. The channel plate 6 is connected to the barrel assembly 4, specifically to the lower end 42 of the barrel assembly 4, and is in fluid communication with the barrel assembly 4. The gear station plate 7 is airtightly connected between the channel plate 6 and the nozzle plate 1, for example, by a seal ring. The nozzle plate 1 has a channel 11 extending therethrough. In the prior art, dispensing assemblies include, for example, but not limited to, piston pumps, screw pumps, metering rod pumps, cycloidal pumps, and / or peristaltic pumps. The difference is that the dispensing assembly 16 of the present invention includes a positive displacement cavity pump with a specially designed flow path and gear set 8, as described below. The positive displacement cavity pump of this embodiment allows for dispensing of a desired amount of fluid without relying on any viscosity changes the fluid undergoes while stored in a barrel prior to use.

[0045] As shown in FIG. 3, the gear set 8 is mounted on the gear fixing plate 7 and on the nozzle plate 1 in a manner known in the art. The flow passage plate 6 includes a plurality of flow passages, some of which extend parallel to the rotation axis of the gear set 8 and are in direct fluid communication with the fluid inlet 85 (see FIG. 4) of the gear set 8. Preferably, the rotation axis of the gear set 8 is parallel to the barrel insertion direction. In prior art, the inflow direction of the gear set is generally perpendicular to the rotation axis of the gear set, and the outflow direction is generally parallel to the rotation axis of the gear set, or the fluid inlet and outlet of the gear set are located on the same mating surface. Furthermore, in this case, such an installation method can adversely affect the final distribution performance. Specifically, because the fluid from the barrel assembly impacts the gear set, some of the fluid may pass directly through the meshing portion of the gear set and reach the fluid outlet, resulting in poor fluid distribution accuracy. In contrast, in the present invention, a portion of the flow passages in the flow passage plate 6 extends in a direction parallel to the rotation axis of the gear set 8 and is in direct fluid communication with the fluid inlet 85 of the gear set 8. That is, the portion of the flow passages in the flow passage plate 6 that is in direct fluid communication with the fluid inlet 85 of the gear set 8 is perpendicular to the gear face of the gear set 8, so that the inlet and outlet passages of the gear set are located on opposite sides of the rotation axis. Therefore, the fluid from the barrel assembly does not directly impact the gear set, which helps to maintain the balance of the vertical force of the gear set, thereby improving the fluid distribution accuracy.

[0046] 3, the flow path plate 6 has a first flow path 61, a second flow path 62, and a third flow path 63. The first flow path 61 extends in a direction parallel to the longitudinal axis of the barrel assembly 4 and receives fluid from the barrel assembly 4. The second flow path 62 is in fluid communication with the first flow path 61 and the third flow path 63. The third flow path 63 extends in a direction parallel to the rotation axis of the gear set 8 and is in direct fluid communication with a fluid inlet 85 (see FIG. 4) of the gear set 8. Since the fluid from the third flow path 63 does not directly impinge in the in-plane direction of the gear set, the distribution accuracy of the fluid is improved.

[0047] As shown in FIGS. 1 to 3, a nozzle plate 1 of a dispensing assembly 16 is in fluid communication with a gear set 8 of the dispensing assembly 16. A flow path 11 of the nozzle plate 1 passes through the nozzle plate 1 in the vertical direction. The nozzle plate 1 has a main body and a protrusion 14 protruding from the main body. The flow path 11 passes through the main body and the protrusion 14 and preferably has a linear shape. A nozzle 10 may be coupled to the protrusion 14 of the nozzle plate 1, for example, by a screw. The nozzle plate 1, specifically the protrusion 14 of the nozzle plate 1, has an outlet 141. The nozzle 10 can control various aspects of fluid distribution.

[0048] The nozzle 10 can control different aspects of fluid distribution. For example, but not limited to, the nozzle 10 can be adapted to control the thickness and / or flow direction of the fluid dispensed outside the barrel assembly 4. Additionally, the nozzle plate 1 and / or the nozzle 10 can be heated, for example, using any heater, to maintain the fluid in a molten state when it completely leaves the nozzle 10. Alternatively, or additionally, the nozzle plate 1 and / or the nozzle 10 can receive heat by conduction from a heated housing 40. For example, the nozzle 10 includes a thin-walled hollow tube 101 that can determine the diameter of the final filament of fluid dispensed through the nozzle 10. The thin-walled hollow tube 101 is aligned with and in fluid communication with the outlet 141 of the nozzle plate 1 (or its protrusion 14).

[0049] As shown in FIGS. 2(a) and 4, the gear fixing plate 7 according to this embodiment has an opening 71, and the gear set 8 is disposed in the opening 71 of the gear fixing plate 7. The gears of the gear set 8 have approximately the same thickness as the gear fixing plate 7. The gear set 8 includes a drive gear 81, a driven gear 82, a drive shaft 83 to which the drive gear 81 is attached, and a driven shaft 84 to which the driven gear 82 is attached. The drive gear 81 and the driven gear 82 may be configured as a pair of spur gears. However, this is not limiting, and other gear configurations are also possible. The drive gear 81 meshes with the driven gear 82, enabling fluid to be discharged from one side of the gear set to the other side.

[0050] Specifically, as shown in FIG. 4, when drive gear 81 rotates counterclockwise, fluid from one side of the plane in which gear set 8 is located, i.e., fluid inlet 85, is carried by the teeth of gears 81 and 82 until it flows out from the other side of the plane in which gear set 8 is located, i.e., fluid outlet 86.

[0051] In particular, the gears of the gear set 8 are not standard gears but customized gears. In other words, the gears of the gear set 8 are non-standard gears. Specifically, the gear set 8 is designed so that the addendum coefficient of the drive gear and the driven gear is greater than the top clearance coefficient. In the present invention, a precise amount of fluid can be discharged from the discharge port 86 of the gear set 8 according to the cooperation of the drive gear 81 and the driven gear 82 of the gear set 8. This can provide improved fluid transport performance.

[0052] Preferably, each of the drive gear 81 and driven gear 82 of the gear set 8 has a tooth addendum factor of 0.7 and a top clearance factor of 0.3, thereby achieving optimum fluid transport performance.

[0053] Thus, a pair of spur gears, for example, is specially designed to deliver a very small amount of fluid with high precision per gear revolution. The gear set, in turn, may be made from hardened tool steel for high durability and a high surface finish. Clearly, the VCP dispensing system of the present invention is capable of continuously and precisely delivering fluids, such as thermal adhesives, to the end of a nozzle.

[0054] 2a is a partially enlarged cross-sectional view of the VCP of the coating system. Unlike conventional techniques that typically use an idler gear as a driven gear, the driven gear 82 of this embodiment has a driven shaft 84, as shown in FIG. 2a. The driven gear 82 is rotatably supported by the driven shaft 84. The driven shaft 84 penetrates the gear fixing plate 7. One end of the driven shaft 84 is inserted into the flow path plate 6, and the other end is inserted into the nozzle plate 1.

[0055] In this way, the driven shaft 84 is not only used to rotate the gear, but also as a positioning pin shaft for positioning the driven gear 82. The positioning pin shaft is used to accurately position the nozzle plate 1, the gear fixing plate 7, and the flow path plate 6. Therefore, essentially, this design is completely different from existing metering systems.

[0056] The fluid outlet of the dispensing assembly 16, i.e., the fluid outlet 86 of the gear set 8, is fluidly connected to one end, i.e., the upper end, of the flow path 11. The fluid from the fluid outlet 86 of the gear set 8 can be discharged linearly along the flow path 11, thereby forming a linear feed / direct delivery mode. The other end, i.e., the lower end, of the flow path 11 or the discharge port 141 is fluidly connected to the nozzle 10. Therefore, the fluid from the gear set 8 of the dispensing assembly 16 is distributed through the flow path 11 and the nozzle 10 to the outside of the application system, for example, to the surface of the workpiece. Compared with a positive displacement cavity pump with a shut-off module, this direct-flow positive displacement cavity pump has many advantages, including a simple flow path design, relatively low manufacturing costs, a good shut-off line end pattern without adhesive hammer, convenient maintenance, and a short outflow length suitable for high-viscosity materials, etc.

[0057] 2-4, the drive assembly 3 of the application system includes a housing 31 and a motor 30 disposed within the housing 31. The motor 30 may be, for example, but not limited to, a DC stepper motor or an inverse servo motor, the actuation and rotation of which results in the selective dispensing of fluid. More specifically, the motor 30 is coupled to a drive gear 81 via a motor shaft in a manner known in the art, such that its rotation rotates the drive gear 81 and a driven gear 82 to meter fluid. Specifically, the motor rotor is connected to the motor shaft via a flexible coupling clutch, which in turn is connected to the drive shaft 83 of the drive gear 81 via a flexible coupling clutch. As a result, rotation of the motor shaft rotates the drive gear 81.

[0058] The application system further includes an electrical junction box assembly 5 containing wiring terminals, etc. Heating elements, such as heating rods and / or temperature sensor signal wiring, are connected to a controller (not shown) of the application system through the electrical junction box assembly 5.

[0059] When the application system is operating, the rotation of the motor rotor rotates the drive shaft 83, causing gears 81 and 82 to mesh. Thanks to the rotation of the gears of gear set 8, the fluid from barrel assembly 4 flows through the flow passages of flow passage plate 6, passes through gear set 8, and is continuously forced out of outlet 86 of gear set 8 to be discharged through outlet 141 of protrusion 14 of nozzle plate 1. Considering the working principle of a positive displacement cavity pump, its output volume is very accurate and consistent.

[0060] FIG. 5 is a cross-sectional view of a coating system according to a second embodiment of the present invention, showing a pressure-controlled check valve disposed on a nozzle plate 1, and FIG. 6 is an enlarged view of the pressure-controlled check valve. For ease of explanation, the same reference numerals in FIGS. 5-6 indicate the same features as in FIGS. 1-4, and these same features may be referenced to understand the features and / or functions of the coating system. Referring to FIGS. 5-6, the coating system also includes a pressure-controlled check valve 9. The pressure-controlled check valve 9 is provided on the nozzle plate 1.

[0061] As clearly shown in FIG. 6 , the pressure control check valve 9 includes a ball 91, a spring 92 supporting the ball, a spring seat 93, and a seat passage 94 within the spring seat 93. The passage 11 of the nozzle plate 1 has a small diameter portion and a large diameter portion, the small diameter portion fluidly communicates with the gear set 8, and the large diameter portion is located downstream of the small diameter portion in the fluid flow direction. The pressure control check valve 9 is provided in the passage 11 of the nozzle plate 1, specifically in the large diameter portion. When the fluid pressure in the small diameter portion exceeds a predetermined threshold, the ball 91 leaves the ball seat and moves downward, thereby opening the pressure control check valve 9 and allowing the fluid to flow through the seat passage 94 of the pressure control check valve 9 to the outlet 141 of the nozzle plate 1, distributing the fluid outside the nozzle plate 1, for example, through the nozzle 10, onto the surface of the workpiece.

[0062] On the other hand, when the pressure of the fluid in the small diameter portion is equal to or lower than a predetermined threshold, the ball 91 abuts against the upper part of the ball seat, thereby closing the pressure control check valve 9. Therefore, the fluid is held in the small diameter portion of the flow path 11 of the nozzle plate 1 and cannot flow out.

[0063] According to the above configuration, when the application system is closed, fluid leakage can be effectively suppressed in time, and the formation of a large fluid head at the end of the application operation can be effectively prevented.

[0064] FIG. 7 is a perspective view of a VCP-integrated coating system according to a third embodiment of the present invention, the coating system having a control valve assembly. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. For ease of explanation, the same reference numerals in FIG. 7 indicate the same features as in FIGS. 1-6, and these same features can be referenced to understand the features and / or functions of the coating system. Referring to FIGS. 7-8, the coating system also includes a control valve assembly 2. The control valve assembly 2 is disposed on a side of the drive assembly 3 generally opposite the barrel assembly 4, and is attached to the nozzle plate 1, for example, by screws.

[0065] As shown in FIGS. 8 and 10 , the control valve assembly 2 includes a needle housing 201, a passage housing 202, and a top cover 203. The needle housing 201 and the top cover 203 are attached together to form an internal space. The passage housing 202 is attached to the needle housing 201 on the side opposite the top cover 203. The control valve assembly 2 includes a needle 21 and a needle passage 22, and the needle is movable within the needle passage 22 to open and close it. The needle passage 22 is disposed within the passage housing 202. The needle passage 22 is fluidly connected to a flow path in the nozzle plate 1, for example, via a transfer passage 2011 in the needle housing 201 and a transfer passage 2021 in the passage housing 202. The axis of the needle 21 coincides with the passage axis of the needle passage 22. When the needle 21 moves downward in the needle passage 22, the tip of the needle 21 abuts against the needle seat of the needle passage 22, thereby closing the needle passage 22. Conversely, when the needle 21 moves upward in the needle passage 22, i.e., away from the needle seat, the needle passage 22 opens, allowing fluid to flow out of the needle passage 22. The control valve assembly 2 is an integrated component. The control valve assembly 2 forms a shutoff module separate from the nozzle plate 1. The control valve assembly 2 is attached to the nozzle plate 1, which has many advantages for improving heating efficiency and fluid mobility. A nozzle may also be attached to the end of the control valve assembly 2. During operation, fluid flows from the outlet of the gear set 8 through the nozzle plate 1, then directly into the control valve assembly 2 as a shutoff valve, and finally, the fluid flows out of the nozzle under the control of the shutoff valve.

[0066] When an independent shut-off valve is provided, the flow passages in the nozzle plate 1 can have a variety of configurations. For example, as shown in Figure 8, the flow passages in the nozzle plate 1 are integral flow passages 11 that are inclined relative to the axis of rotation of the gear set 8, while as shown in Figure 10, the flow passages in the nozzle plate 1 include a first flow passage 111 and a second flow passage 112, where the first flow passage 111 extends from the fluid outlet 86 of the gear set 8 and the second flow passage 112 extends at an angle (preferably perpendicular) to the first flow passage 111 and is in fluid communication with the needle passage 22.

[0067] In prior art dispensing systems, after the dispensing system is closed, a small portion of the fluid still flows from the pump toward the nozzle, which causes fluid hammer on the surface of the workpiece. However, in the present invention, as clearly shown in FIG. 10 , when the needle 21 of the control valve assembly 2 abuts against the needle seat in the flow passage 22 of the control valve assembly 2 to stop the fluid flow, the fluid from the pump assembly 8 will flow into the mold cavity of the shut-off module, specifically into the movement space of the needle 21, but will not be discharged from the control valve assembly 2. Therefore, compared to the first embodiment, the shut-off module enables a dispensing system that effectively prevents the heated fluid from continuously flowing out of the nozzle after the positive displacement cavity pump is closed.

[0068] As an alternative to a separate shut-off valve or an integrated component, the control valve assembly 2 can also be formed by the nozzle plate 1. Specifically, as shown in FIG. 9 , the control valve assembly 2 includes a needle housing 201 and a top cover 203, but does not have a flow channel housing, as shown in FIG. 10 . The flow channels of the nozzle plate 1 include a first flow channel 111, a second flow channel 112, and a third flow channel 113, where the first flow channel 111 extends from the fluid outlet 86 of the gear set 8, the second flow channel 112 fluidly connects the first flow channel 111 and the third flow channel 113, and the third flow channel 113 extends to the outlet 141 of the nozzle plate 1. The needle housing 201 of the control valve assembly 2 is attached to the nozzle plate 1 such that the tip of the needle 21 of the control valve assembly 2 is movable in the third flow channel 113 to control the distribution of fluid from the nozzle plate 1. As a result, the third flow path 113 of the nozzle plate 1 functions as the passage 22 in FIG.

[0069] The motor rotor of motor 30 is flexibly connected to gear set 8. Specifically, the motor rotor is connected to motor shaft 32 via flex coupling clutch C1, and motor shaft 32 is in turn connected to drive shaft 83 of gear set 8 via flex coupling clutch C2 (see FIG. 3).

[0070] 9, the control valve assembly 2 as a shutoff valve is designed integrally with the nozzle plate 1. The advantage of this design is that it further optimizes the flow path design and reduces the flow resistance of the fluid, thereby improving the application effect (such as the gluing effect) of the fluid.

[0071] Generally, there are machining and assembly tolerances when manufacturing gears and fixed plates. Therefore, gaps between the gear teeth and the housing are inevitable. These gaps cause dripping and leakage at the nozzle tip even when the VCP stops rotating. However, the present invention combines an advanced dispensing module with a VCP distributor, so that fluid must flow into the mold cavity formed by the control valve assembly 2 and the nozzle plate 1 before exiting the nozzle 10. In the mold cavity, the needle 21 moves up and down to function as a switch, thereby preventing dripping and leakage at the nozzle tip after the VCP is closed.

[0072] Furthermore, the dispensing system of the present invention completely inherits the dispensing function of a conventional VCP.The dispensing system is compact and sophisticated in design, is very easy to maintain and operate, and prevents fluid leakage.

[0073] Figure 11 is a partial perspective view with a portion of the top flow plate removed to show the grooves in the top flow plate. As shown in Figure 11, the side of the flow plate 6 facing the gear set 8 has a groove 64 formed in an area corresponding to the fluid outlet 86 of the gear set 8. The contour and location of this groove are designed to reduce the hydraulic pressure of the fluid trapped by the meshed gear teeth, thereby improving the fluid flow stability.

[0074] The coating system further includes a plug rod 65. The plug rod 65 is inserted into a flow path of the coating system to block one end of the flow path. For example, the plug rod 65 is inserted into the substantially horizontal flow path 62 of the flow path plate 6 from one side, thereby diverting the fluid in the flow path. The length and end shape of the plug rod 65 are designed so that the plug rod can appropriately remove any dead ends of the fluid in the flow path. If necessary, the plug rod 65 can be removed for easy cleaning and maintenance of the flow path.

[0075] The thickness of the gears of the gear set 8 is the same nominal size as the thickness of the gear fixing plate 7. The tolerance of the thickness of both can be selected appropriately while ensuring that the gears can move freely within the contours of the fixing plate 7.

[0076] Any of the dispensing systems according to the present invention can be configured to respond to an analog signal from a speed-sensing device (not shown), which is proportional to the speed of any robot on which the device may be mounted. Such an analog signal can be provided, for example, to a microprocessor (not shown) electrically coupled to the corresponding motor. Additional control mechanisms include arranging for the microprocessor to reverse adhesive flow at the end of a cycle by reversing the direction and / or speed of the motor and / or gear set. Reversing the direction and / or speed of the motor and / or pump at the end of each cycle can also help maintain tight control of any portion of fluid that may remain in the flow path or conduit during dispensing.

[0077] While the present invention has been illustrated by the description of various embodiments, and these embodiments have been described in considerable detail, it is not intended in any way to restrict or limit the scope of the appended claims to such details. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Consequently, departures may be made from such details without departing from the spirit or scope of the general inventive concept. [Explanation of symbols]

[0078] 1 nozzle plate 10 nozzles 101 Thin wall hollow tube 11 Flow path 111 (First) Channel 112 (Second) Channel 113 (Third) Channel 14 Protrusion 141 Discharge port 2 Control Valve Assembly 201 Needle housing 2011 Transfer passage 202 Passage Housing 2022 Transfer passage 203 Top cover 21 Needle 22 Needle Passage 3 Drive housing 30 motor 31 Housing 32 motor shaft 4 Barrel Assembly 40 Housing 41 Proximal end 42 distal end 421 Discharge port 43 Cover 430 Covered passage 5 Electrical Junction Box Assembly 6 Flow path plate 61 (First) Channel 62 (Second) Channel 63 (Third) Channel 64 Groove 65 plug rod 7 Gear fixing plate 71 Aperture 8 gear sets 81 Drive gear 82 Driven gear 83 Drive shaft 84 driven shaft C1 Flexible Coupling Clutch C2 Flexible Coupling Clutch

Claims

1. 1. A dispensing assembly comprising a positive displacement cavity pump, a flow channel plate having flow channels for fluid flow; a nozzle plate having a flow path therethrough; a gear fixing plate attached between the flow path plate and the nozzle plate and having an opening; a gear set located in the opening of the gear fixing plate, the gear set having a fluid inlet and a fluid outlet on an opposite side of the gear set from the fluid inlet, the fluid inlet fluidly communicating with the flow passages of the flow passage plate and the fluid outlet fluidly communicating with the flow passages of the nozzle plate; a nozzle coupled to the nozzle plate or to a control valve assembly coupled to the nozzle plate; Equipped with a portion of the flow passage in the flow passage plate that is in direct fluid communication with the fluid inlet extends in a direction parallel to an axis of rotation of the gear set; a flow path plate having a first flow path, a second flow path, and a third flow path, the first flow path receiving a fluid from an outside, the second flow path fluidly connecting the first flow path and the third flow path, and the third flow path extending in a direction parallel to the rotational axis of the gear set and directly fluidly connecting to the fluid inlet.

2. 1) the nozzle is coupled to a protrusion that protrudes from the main body of the nozzle plate, and the flow path through the nozzle plate penetrates the main body and the protrusion, or 2) The dispensing assembly of claim 1, further comprising a control valve assembly having a needle for controlling the dispensing of fluid from the dispensing assembly, the control valve assembly being an integral component attached to the nozzle plate, the control valve assembly including a needle passage, the needle being movable in the needle passage, the needle passage being fluidly connected to the flow path of the nozzle plate, and the nozzle being attached to the end of the control valve assembly.

3. 2. The dispensing assembly of claim 1, wherein the gear set includes a drive gear and a driven gear, the drive gear being drivable to rotate, thereby driving the driven gear to rotate, and the drive gear and the driven gear being non-standard gears.

4. 4. A dispensing assembly according to claim 3, wherein the addendum coefficient is 0.7 and the tip gap coefficient is 0.

3.

5. A dispensing assembly according to claim 3 or 4, wherein the driven gear comprises a gear shaft.

6. The dispensing assembly of claim 5 , wherein one end of the gear shaft is inserted into the flow path plate and the other end of the gear shaft is inserted into the nozzle plate.

7. The dispensing assembly of claim 1 , wherein each of the first flow path, the second flow path, the third flow path and the flow path of the nozzle plate is linear.

8. A dispensing assembly according to any one of claims 1 to 4, wherein the flow passages of the nozzle plate are provided with pressure-controlled check valves for opening and closing the flow passages of the nozzle plate.

9. 10. The dispensing assembly of claim 1, wherein the dispensing assembly comprises a control valve assembly having a needle for controlling the dispensing of fluid from the dispensing assembly.

10. The dispensing assembly of claim 9, wherein the control valve assembly is an integral component attached to the nozzle plate, the control valve assembly includes a needle passage, the needle is movable in the needle passage, and the needle passage is fluidly connected to the flow path of the nozzle plate.

11. The dispensing assembly of claim 10 , wherein the flow passages in the nozzle plate are linear flow passages that are inclined relative to the axis of rotation of the gear set.

12. 11. The dispensing assembly of claim 10, wherein the flow passages of the nozzle plate include a first flow passage and a second flow passage, the first flow passage extending from the fluid outlet of the gear set, and the second flow passage extending at an angle to the first flow passage and fluidly communicating with the needle passage.

13. the control valve assembly includes a needle housing and a top cover, the top cover being attached to the needle housing to define an interior space within which one end of the needle is housed; the flow passages of the nozzle plate include a first flow passage, a second flow passage, and a third flow passage, the first flow passage extending from the fluid outlet of the gear set, the second flow passage fluidly communicating the first flow passage and the third flow passage, and the third flow passage extending to an outlet of the nozzle plate; and The dispensing assembly of claim 9, wherein the needle housing of the control valve assembly is attached to the nozzle plate, and the other end of the needle of the control valve assembly is movable in the third flow path to control the dispensing of the fluid from the nozzle plate.

14. A dispensing assembly according to any one of claims 1 to 4, wherein the side of the flow path plate facing the gear set is formed with grooves in areas corresponding to the fluid outlets of the gear set.

15. 5. A dispensing assembly according to any one of claims 1 to 4, wherein a plug rod is provided that is designed to be inserted into the flow path of the dispensing assembly to remove any fluid dead ends in the flow path.

16. A dispensing assembly according to any one of claims 1 to 4, wherein the thickness of the gears of the gear set is of the same nominal size as the thickness of the gear fixing plate.

17. 1. A coating system comprising: a barrel assembly including a barrel for containing a fluid; 17. A dispensing assembly according to any one of claims 1 to 16, wherein the dispensing assembly is attached to and in fluid communication with the barrel assembly; a drive assembly for driving the dispensing assembly to dispense the fluid from the barrel assembly through the dispensing assembly; A coating system comprising:

18. 2) the nozzle is attached to an end of the control valve assembly attached to the nozzle plate, and the fluid outlet of the gear set and the nozzle plate are configured such that, during operation, fluid flows from the fluid outlet of the gear set through the nozzle plate, then is injected directly into the control valve assembly as a shut-off valve, and then flows out of the nozzle under the control of the shut-off valve.

19. A dispensing assembly as described in any one of claims 1 to 4 or 7, wherein fluid from the third flow path does not directly impinge on the gear set in an in-plane direction of the gear set.

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