Unitized Valve Seat Assembly

Abstract

A valve seat assembly including a housing having a cavity and a puck located within the cavity and connected to the housing, the puck having a harder hardness than the housing.

Description

[Technical field]

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 62 / 734,801, filed Sep. 21, 2018, which is incorporated herein by reference.

[0002] The present disclosure relates to valve seat assemblies that may be used in a dispensing device and that define a nozzle for dispensing a liquid. More particularly, the present disclosure relates to a wear-resistant valve seat assembly. [Background technology]

[0003] Microdispensing is the process of dispensing very small amounts of liquid from a nozzle. This process can be used for any application, including but not limited to adhesives, solvents, and inks or dispensing materials in 3D printing processes. Microdispensing can include the use of a nozzle with a valve seat on top and a dispensing orifice on the bottom. A valve element engages and disengages with the valve seat on the top of the nozzle to control the release of liquid flowing through the nozzle. For example, the valve element and the valve seat have a mating point that forms a seal and prevents the flow of fluid through the nozzle. When the valve element is actuated to retract from the mating point, the fluid travels around the valve element, through a channel, and out of the nozzle. When the valve element is actuated to re-engage the valve seat, the flow of fluid through the nozzle stops.

[0004] Actuation of the valve element occurs extremely quickly, potentially billions of actuations in a very short period of time. All of the actuations can wear down the nozzle's valve seat very quickly. In addition to wear from contact with the valve element, if the fluid being processed is abrasive, the fluid can leave a residue on the component. This residue can become lodged in the nozzle during actuation, and this retention of abrasive particles can accelerate material degradation and result in component failure.

[0005] Wear on the valve seats results in parts requiring replacement. Replacement of parts shuts down the equipment that uses those components and prevents the end product from being produced. Additionally, the very small size of the nozzle parts makes it difficult to replace the nozzles when wear occurs.

[0006] To reduce material wear, it is desirable to use nozzles made of materials with greater hardness, which have greater wear resistance. However, while materials with greater hardness have better wear resistance properties, such materials are also generally very brittle and therefore prone to cracking and chipping. It is undesirable to use materials that are prone to cracking and chipping when placed under repeated pressure, as such materials also require frequent replacement. Summary of the Invention

[0007] Therefore, there is a need for parts that are resistant to wear and are less prone to cracking and chipping. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of one embodiment of a valve seat assembly according to the present disclosure. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of the valve seat assembly. [Diagram 3] FIG. 3 is a perspective view of one embodiment of a pack according to the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view of the pack shown in FIG. [Diagram 5] FIG. 5 is a perspective cross-sectional view of the pack of FIG. 3 shown engaged with a valve element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Turning now to the figures, Figure 1 illustrates one embodiment of a valve seat assembly 100 shown with a valve element 102. The valve seat assembly 100 may be used in a variety of different devices and machines. For example, the valve seat assembly may be part of a micro-dispensing device used to dispense minute amounts of oil, adhesive, liquid or any other medium. The valve seat assembly may be used in applications such as printing and 3-D printing or circuit board assembly, among others.

[0010] The valve seat assembly 100 includes a housing 104 and a puck 106, which are made of different materials and connected to one another. The housing 104 includes a cavity 108 into which the puck 106 is received or accommodated. Preferably, the housing 104 and the puck 106 are permanently affixed to one another to form a unitized, integral assembly. The housing 104 may be of various shapes and sizes, which may vary depending on the type of device into which the valve seat is to be incorporated. Additionally, the housing 104 has a lower hardness (kg / mm) than the material of the puck 106. 2 ) The housing material may be, for example, tungsten carbide, hardened tool steel, aluminum, etc.

[0011] 3 and 4, the illustrated puck 106 includes a cylindrical or approximately cylindrical body. In other embodiments, the body may have other geometric or non-geometric shapes. The puck may also have a height H between about 0.05 inches and about 0.5 inches and a cross-sectional width W between about 0.1 inches and about 0.5 inches. When the puck is cylindrical, the cross-sectional width is the diameter. In one embodiment, the height of the puck may be about 0.125 inches (3.18 mm) or less and the cross-sectional width may be about 0.125 inches (3.18 mm) or less. In the illustrated embodiment, the top 110 of the puck may have an edge 112 and may optionally define a funnel-shaped portion 114. The funnel-shaped portion 114 may be any shape that gradually slopes inward toward the center of the puck 106. In the illustrated embodiment, the funnel-shaped portion 114 may be conical. In one embodiment, the conical shape may be a frusto-conical shape. The height and diameter of the cone shape may vary depending on the desired application. As shown in Figures 1, 2 and 4, the top 114 of the puck 106 defines a valve seat that engages the valve element 102. In addition, the surface of the funnel 114 may be smooth or textured. For example, the surface may include rings, ridges, bumps or other textures.

[0012] Where the puck 106 defines a nozzle for dispensing a material, the puck 106 may include a channel 116 passing therethrough for dispensing a material, such as any of the liquid materials mentioned above. The channel 116 may have an opening 109 at the bottom 111 of the puck. The channel may have an opening or diameter that is between about 0.0005 inches and about 0.080 inches. In one embodiment, the opening of the channel may be about 0.012 inches.

[0013] The puck 106 may be made from a material having a hardness greater than the hardness of the housing 104. In one embodiment, the material of the puck 106 has a hardness of approximately 2,800 kg / mm 2 In another embodiment, the material has a Vickers hardness of about 3,000 kg / mm 2 or more, or about 4,000 kg / mm 2or more. In one embodiment, the material of the puck 106 may include silicon carbide. In other embodiments, the material of the puck 106 may include diamond material. For example, the diamond material of the puck 106 may be in an amount greater than 79% by volume, greater than 85% by volume, or between 85% by volume and 95% by volume. The diamond material may be, for example, ceramic diamond material, polycrystalline diamond material, or any other suitable diamond material. Additionally, the material of the puck 106 may be a composite material including diamond material and a binder. Such binders include cobalt, silicon carbide, and other suitable binders. The binder may take into account that the material has a specific electrical conductivity so that it may be machined using an electron discharge machining process. This and other processes may be employed to form finished features in the puck that allow fluid to flow through the nozzle. Additionally, in addition to being wear resistant, diamond material has a low coefficient of friction, which may help prevent the dispensed material from adhering to the puck 106.

[0014] The puck 106 may be connected to the housing 104 by a bond. Preferably, the bond permanently secures the housing 104 and the puck 106 to one another to form a unitized, integral assembly. The bond may be, for example, a braze. In one embodiment, the braze may be an alloy braze. The alloy braze may include the elements titanium, silver, nickel, aluminum, indium, tin, and / or copper. The puck and the housing may also be connected in other ways, such as with an epoxy, shrink fit, press fit, machine fit, etc. Referring to FIGS. 1 and 2, the puck 106 may be connected to the housing 104 along an edge 112. For example, the puck may be connected to the housing 104 by a brazed joint 118 between the housing 104 and the edge 112. Alternatively, or in addition to connecting the puck to the housing at the edge of the puck, the puck may be connected to the housing at any point along the body of the puck.

[0015] As mentioned above, the material of the puck 106 may have a harder hardness than the material of the housing 104. Additionally, the material of the housing 104 may have a greater fracture toughness than the material of the puck 106, based on ASTM E1820-18. In one embodiment, the material of the housing is bonded with a bonding medium, which places the diamond material of the puck 106 in compression and forms a shock absorbing mechanism around the diamond material. With the puck 106 and the housing 104 acting as a unitized single entity, the toughness of the housing and the bonding mechanism allows the diamond-like material to absorb shock during use, creating a mechanism of action that reduces the risk of fracture and chipping of the puck material. Additionally, the housing 104 allows for the capture of the puck 106 in a manner that makes the assembly easy to handle. For example, the assembly can be moved through manufacturing operations to end use with minimal risk to chipping.

[0016] 1, 2 and 4, in one application, the puck 106 can define a nozzle for microdispensing fluid. In the closed position, the valve element 102 seats or engages a funnel 114 on the top surface of the puck 106 to close the channel 116. The valve element 102 can have a portion having a shape and size that matches or corresponds to the shape and size of the funnel 114 or the valve seat. In the illustrated embodiment, the valve element 102 includes a body having a plug portion 120 and a bottom portion 122. The plug portion 120 can be any shape, such as cylindrical. In the illustrated embodiment, the plug portion 120 includes a flange 124 that can be used to connect the valve element to a device. The bottom portion 122 defines a closure member that mates with the top portion 114 of the puck 106 to close the channel 116 of the puck. The bottom portion 122 of the valve element 102 defines a conical shape sized to match the funnel portion 114 of the pack 106. To close the channel 116 of the pack 106, the bottom portion 122 of the valve element 102 is inserted into and / or mated with the funnel / valve seat of the pack 106.

[0017] To dispense material, the valve element 102 is actuated to move upwards in the figure and out of the funnel 114 at the top of the puck 106. This allows the material to move through the channel 116 for dispensing. The valve element 102 is then actuated to move downwards in the figure and mate or engage with the funnel 114 at the top of the puck 106, closing off the channel 116. Depending on the application and device, actuation of the valve element 102 can occur very quickly, with billions of actuations occurring in a very short period of time. Thus, the valve element 102 can disengage and engage the puck 106 multiple times in a very short period of time. As discussed above, the puck 106 and housing 104 are coupled to minimize the forces associated with actuation of the valve element 102 on the puck 106, reducing the risk of brittle fracture of the diamond material of the puck 106.

[0018] Additionally, minimal friction results in reduced surface tension, allowing for more consistent droplets to be generated from the orifice outlet. The puck 106 may be made from a material having a coefficient of friction less than that of the housing 104. In one embodiment, the material of the puck 106 may have a static and kinetic coefficient of friction that is about 0.2 or less, based on ASTM G115-10(2018). In other embodiments, it may be less than 0.15, or about 0.1 or less.

[0019] Having thus described the apparatus, various modifications and variations will occur to those skilled in the art which will fall within the scope of the apparatus as defined by the appended claims.

Claims

1. a housing having a cavity; a puck located within the cavity and connected to the housing, The pack contains 85% to 95% by volume of diamond and silicon carbide ceramic bond material based on the total volume of the pack, and has a compressive strength of 2,800 kg / mm 2 the housing is made of a material having a hardness lower than that of the material of the puck; The puck is permanently secured to the housing by titanium alloy brazing. Valve seat assembly.

2. The pack has a strength of 3000 kg / mm 2 The valve seat assembly of claim 1 having a hardness of at least about 100 mm.

3. The valve seat assembly of claim 1 , wherein the diamond is a polycrystalline diamond.

4. The valve seat assembly of claim 1 , wherein the puck defines a nozzle having a distribution channel therethrough.

5. 5. The valve seat assembly of claim 4, wherein the distribution channels of the puck have orifices of 0.3 mm (0.012 inches) or less.

6. 2. The valve seat assembly of claim 1, wherein the puck has a height of 0.125 inches (3.18 mm) or less and a cross-sectional width of 0.125 inches (3.18 mm) or less.

7. The valve seat assembly of claim 1 , wherein the puck includes a top that defines a funnel.

8. The valve seat assembly of claim 1 , wherein the puck includes a top portion forming a valve seat configured to mate with a valve element.

9. The valve seat assembly of claim 1 , wherein the housing has a greater fracture toughness than the puck.

10. The valve seat assembly of claim 1 , wherein the puck has a lower coefficient of friction than the housing.

11. The valve seat assembly of claim 1 , wherein the material of the puck has a coefficient of friction of less than 0.

2.

12. A valve seat assembly comprising a housing having a cavity, and a puck located within the cavity and connected to the housing, the puck comprising a material having a hardness of 2,800 kg / mm2 or greater and containing diamond and silicon carbide ceramic bonding material in an amount ranging from 85% to 95% by volume of a total volume of the pack, the housing being made of a material having a lower hardness than the material of the puck, and the puck having channels for distributing a fluid; a valve element operable to open and close the channel in the pack; 1. A microdispensing device for dispensing a fluid, comprising:

Images